Science.gov

Sample records for plasma sheet electrons

  1. Runaway electrons in plasma current sheets

    SciTech Connect

    Gurevich, A.V.; Sudan, R.N. )

    1994-01-31

    It is shown that a runaway electron population accelerates along the main magnetic field in a Sweet-Parker current sheet. After a characteristic distance the entire current is carried by runaways. The thickness of this runaway sheet is much smaller than the original Ohmic sheet. The influence of microinstabilities is discussed.

  2. Observations of Electron Vorticity in the Inner Plasma Sheet

    NASA Technical Reports Server (NTRS)

    Gurgiolo, C.; Goldstein, M. L.; Vinas, A. F.; Matthaeus, W. H.; Fazakerley, A. N.

    2011-01-01

    From a limited number of observations it appears that vorticity is a common feature in the inner plasma sheet. With the four Cluster spacecraft and the four PEACE instruments positioned in a tetrahedral configuration, for the first time it is possible to directly estimate the electron fluid vorticity in a space plasma. We show examples of electron fluid vorticity from multiple plasma sheet crossings. These include three time periods when Cluster passed through a reconnection ion diffusion region. Enhancements in vorticity are seen in association with each crossing of the ion diffusion region.

  3. Observations of ionospheric electron beams in the plasma sheet.

    PubMed

    Zheng, H; Fu, S Y; Zong, Q G; Pu, Z Y; Wang, Y F; Parks, G K

    2012-11-16

    Electrons streaming along the magnetic field direction are frequently observed in the plasma sheet of Earth's geomagnetic tail. The impact of these field-aligned electrons on the dynamics of the geomagnetic tail is however not well understood. Here we report the first detection of field-aligned electrons with fluxes increasing at ~1 keV forming a "cool" beam just prior to the dissipation of energy in the current sheet. These field-aligned beams at ~15 R(E) in the plasma sheet are nearly identical to those commonly observed at auroral altitudes, suggesting the beams are auroral electrons accelerated upward by electric fields parallel (E([parallel])) to the geomagnetic field. The density of the beams relative to the ambient electron density is δn(b)/n(e)~5-13% and the current carried by the beams is ~10(-8)-10(-7) A m(-2). These beams in high β plasmas with large density and temperature gradients appear to satisfy the Bohm criteria to initiate current driven instabilities.

  4. Transport of the plasma sheet electrons to the geostationary distances

    NASA Astrophysics Data System (ADS)

    Ganushkina, N. Y.; Amariutei, O. A.; Shprits, Y.; Liemohn, M. W.

    2012-12-01

    The transport and acceleration of low energy electrons (10-250 keV) from the plasma sheet to the geostationary orbit were investigated. Two moderate storm events, which occurred on November 6-7, 1997 and June 12-14, 2005, were modeled using the Inner Magnetosphere Particle Transport and Acceleration model (IMPTAM) with the boundary set at 10 RE in the plasma sheet. The output of the IMPTAM model was compared to the observed electron fluxes in four energy ranges measured onboard the LANL spacecraft by the SOPA instrument. It was found that the large-scale convection in combination with substorm-associated impulsive fields are the drivers of the transport of plasma sheet electrons from 10 RE to geostationary orbit at 6.6 RE during storm times. The addition of radial diffusion had no significant influence on the modeled electron fluxes. At the same time, comparison between the modeled electron fluxes and observed ones showed two orders of difference most likely due to inaccuracy of electron boundary conditions and omission of the important loss processes due to wave-particle interactions. This did not allow us to accuractly reproduce the dynamics of 150-225 keV electron fluxes. The choice of the large-scale convection electric field model used in simulations did not significantly influence on the modeled electron fluxes, since there is not much difference between the equipotential contours given by the Volland-Stern and Boyle et al. [1997] models at the distances from 10 to 6.6 RE in the plasma sheet. Using the TS05 model for the background magnetic field instead of the T96 model resulted in larger deviations of the modeled electron fluxes from the observed ones due to specific features of the TS05 model. The increase in the modeled electron fluxes can be as large as three orders of magnitude when substorm-associated electromagnetic fields were taken into account. The obtained model distribution of low energy electron fluxes can be used as an input to the radiation

  5. Transport of the plasma sheet electrons to the geostationary distances

    NASA Astrophysics Data System (ADS)

    Ganushkina, N. Y.; Amariutei, O. A.; Shprits, Y. Y.; Liemohn, M. W.

    2013-01-01

    Abstract<p label="1">The transport and acceleration of low-energy <span class="hlt">electrons</span> (50-250 keV) from the <span class="hlt">plasma</span> <span class="hlt">sheet</span> to the geostationary orbit were investigated. Two moderate storm events, which occurred on 6-7 November 1997 and 12-14 June 2005, were modeled using the Inner Magnetosphere Particle Transport and Acceleration model (IMPTAM) with the boundary set at 10 RE in the <span class="hlt">plasma</span> <span class="hlt">sheet</span>. The output of the IMPTAM was compared to the observed <span class="hlt">electron</span> fluxes in four energy ranges (50-225 keV) measured by the Synchronous Orbit Particle Analyzer instrument onboard the Los Alamos National Laboratory spacecraft. It was found that the large-scale convection in combination with substorm-associated impulsive fields is the drivers of the transport of <span class="hlt">plasma</span> <span class="hlt">sheet</span> <span class="hlt">electrons</span> from 10 RE to geostationary orbit at 6.6 RE during storm times. The addition of radial diffusion had no significant influence on the modeled <span class="hlt">electron</span> fluxes. At the same time, the modeled <span class="hlt">electron</span> fluxes are one (two) order(s) smaller than the observed ones for 50-150 keV (150-225 keV) <span class="hlt">electrons</span>, respectively, most likely due to inaccuracy of <span class="hlt">electron</span> boundary conditions. The loss processes due to wave-particle interactions were not considered. The choice of the large-scale convection electric field model used in simulations did not have a significant influence on the modeled <span class="hlt">electron</span> fluxes, since there is not much difference between the equipotential contours given by the Volland-Stern and the Boyle et al. (1997) models at distances from 10 to 6.6 RE in the <span class="hlt">plasma</span> <span class="hlt">sheet</span>. Using the TS05 model for the background magnetic field instead of the T96 model resulted in larger deviations of the modeled <span class="hlt">electron</span> fluxes from the observed ones due to specific features of the TS05 model. The increase in the modeled <span class="hlt">electron</span> fluxes can be as large as two orders of magnitude when substorm-associated electromagnetic fields were taken into account. The obtained model distribution of low-energy <span class="hlt">electron</span></p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/25638082','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/25638082"><span>Experimental investigation of a 1 kA/cm² <span class="hlt">sheet</span> beam <span class="hlt">plasma</span> cathode <span class="hlt">electron</span> gun.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Kumar, Niraj; Pal, Udit Narayan; Pal, Dharmendra Kumar; Prajesh, Rahul; Prakash, Ram</p> <p>2015-01-01</p> <p>In this paper, a cold cathode based <span class="hlt">sheet</span>-beam <span class="hlt">plasma</span> cathode <span class="hlt">electron</span> gun is reported with achieved <span class="hlt">sheet</span>-beam current density ∼1 kA/cm(2) from pseudospark based argon <span class="hlt">plasma</span> for pulse length of ∼200 ns in a single shot experiment. For the qualitative assessment of the <span class="hlt">sheet</span>-beam, an arrangement of three isolated metallic-<span class="hlt">sheets</span> is proposed. The actual shape and size of the <span class="hlt">sheet-electron</span>-beam are obtained through a non-conventional method by proposing a dielectric charging technique and scanning <span class="hlt">electron</span> microscope based imaging. As distinct from the earlier developed <span class="hlt">sheet</span> beam sources, the generated <span class="hlt">sheet</span>-beam has been propagated more than 190 mm distance in a drift space region maintaining <span class="hlt">sheet</span> structure without assistance of any external magnetic field.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/22518992','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/22518992"><span>THIN CURRENT <span class="hlt">SHEETS</span> AND ASSOCIATED <span class="hlt">ELECTRON</span> HEATING IN TURBULENT SPACE <span class="hlt">PLASMA</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Chasapis, A.; Retinò, A.; Sahraoui, F.; Canu, P.; Vaivads, A.; Khotyaintsev, Yu. V.; Sundkvist, D.; Greco, A.; Sorriso-Valvo, L.</p> <p>2015-05-01</p> <p>Intermittent structures, such as thin current <span class="hlt">sheets</span>, are abundant in turbulent <span class="hlt">plasmas</span>. Numerical simulations indicate that such current <span class="hlt">sheets</span> are important sites of energy dissipation and particle heating occurring at kinetic scales. However, direct evidence of dissipation and associated heating within current <span class="hlt">sheets</span> is scarce. Here, we show a new statistical study of local <span class="hlt">electron</span> heating within proton-scale current <span class="hlt">sheets</span> by using high-resolution spacecraft data. Current <span class="hlt">sheets</span> are detected using the Partial Variance of Increments (PVI) method which identifies regions of strong intermittency. We find that strong <span class="hlt">electron</span> heating occurs in high PVI (>3) current <span class="hlt">sheets</span> while no significant heating occurs in low PVI cases (<3), indicating that the former are dominant for energy dissipation. Current <span class="hlt">sheets</span> corresponding to very high PVI (>5) show the strongest heating and most of the time are consistent with ongoing magnetic reconnection. This suggests that reconnection is important for <span class="hlt">electron</span> heating and dissipation at kinetic scales in turbulent <span class="hlt">plasmas</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2000JPhD...33.3190L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2000JPhD...33.3190L"><span>Dynamics of a helium <span class="hlt">plasma</span> <span class="hlt">sheet</span> created by a hollow-cathode <span class="hlt">electron</span> beam</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Larigaldie, S.; Caillault, L.</p> <p>2000-12-01</p> <p>A hollow-cathode device has been shown to operate as a <span class="hlt">plasma</span> reflector for <span class="hlt">electronic</span> steering of radar beams using helium in the 0.2-0.5 Torr pressure range. Compared to previous experiments, the use of this light gas significantly reduces the spurious sputtering effects on the cathode materials. A semi-quantitative physical model was developed to describe the observed evolution of microwave beam transmissions through the <span class="hlt">plasma</span> <span class="hlt">sheet</span> as a function of frequency. This model stresses the importance of <span class="hlt">electron</span>-ion recombination on the edge of the <span class="hlt">plasma</span> <span class="hlt">sheet</span>, due to simultaneous low <span class="hlt">electron</span> temperatures and high <span class="hlt">electron</span> densities.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19990071231','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19990071231"><span>Inner Magnetospheric Superthermal <span class="hlt">Electron</span> Transport: Photoelectron and <span class="hlt">Plasma</span> <span class="hlt">Sheet</span> <span class="hlt">Electron</span> Sources</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Khazanov, G. V.; Liemohn, M. W.; Kozyra, J. U.; Moore, T. E.</p> <p>1998-01-01</p> <p>Two time-dependent kinetic models of superthermal <span class="hlt">electron</span> transport are combined to conduct global calculations of the nonthermal <span class="hlt">electron</span> distribution function throughout the inner magnetosphere. It is shown that the energy range of validity for this combined model extends down to the superthermal-thermal intersection at a few eV, allowing for the calculation of the en- tire distribution function and thus an accurate heating rate to the thermal <span class="hlt">plasma</span>. Because of the linearity of the formulas, the source terms are separated to calculate the distributions from the various populations, namely photoelectrons (PEs) and <span class="hlt">plasma</span> <span class="hlt">sheet</span> <span class="hlt">electrons</span> (PSEs). These distributions are discussed in detail, examining the processes responsible for their formation in the various regions of the inner magnetosphere. It is shown that convection, corotation, and Coulomb collisions are the dominant processes in the formation of the PE distribution function and that PSEs are dominated by the interplay between the drift terms. Of note is that the PEs propagate around the nightside in a narrow channel at the edge of the plasmasphere as Coulomb collisions reduce the fluxes inside of this and convection compresses the flux tubes inward. These distributions are then recombined to show the development of the total superthermal <span class="hlt">electron</span> distribution function in the inner magnetosphere and their influence on the thermal <span class="hlt">plasma</span>. PEs usually dominate the dayside heating, with integral energy fluxes to the ionosphere reaching 10(exp 10) eV/sq cm/s in the plasmasphere, while heating from the PSEs typically does not exceed 10(exp 8) eV/sq cm/s. On the nightside, the inner plasmasphere is usually unheated by superthermal <span class="hlt">electrons</span>. A feature of these combined spectra is that the distribution often has upward slopes with energy, particularly at the crossover from PE to PSE dominance, indicating that instabilities are possible.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/4794830','DOE-PATENT-XML'); return false;" href="http://www.osti.gov/scitech/biblio/4794830"><span><span class="hlt">SHEET</span> <span class="hlt">PLASMA</span> DEVICE</span></a></p> <p><a target="_blank" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Henderson, O.A.</p> <p>1962-07-17</p> <p>An ion-<span class="hlt">electron</span> <span class="hlt">plasma</span> heating apparatus of the pinch tube class was developed wherein a <span class="hlt">plasma</span> is formed by an intense arc discharge through a gas and is radially constricted by the magnetic field of the discharge. To avoid kink and interchange instabilities which can disrupt a conventional arc shortiy after it is formed, the apparatus is a pinch tube with a flat configuration for forming a <span class="hlt">sheet</span> of <span class="hlt">plasma</span> between two conductive plates disposed parallel and adjacent to the <span class="hlt">plasma</span> <span class="hlt">sheet</span>. Kink instabilities are suppressed by image currents induced in the conductive plates while the interchange instabilities are neutrally stable because of the flat <span class="hlt">plasma</span> configuration wherein such instabilities may occur but do not dynamically increase in amplitude. (AEC)</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/22392313','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/22392313"><span>Experimental investigation of a 1 kA/cm{sup 2} <span class="hlt">sheet</span> beam <span class="hlt">plasma</span> cathode <span class="hlt">electron</span> gun</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Kumar, Niraj Narayan Pal, Udit; Prajesh, Rahul; Prakash, Ram; Kumar Pal, Dharmendra</p> <p>2015-01-15</p> <p>In this paper, a cold cathode based <span class="hlt">sheet</span>-beam <span class="hlt">plasma</span> cathode <span class="hlt">electron</span> gun is reported with achieved <span class="hlt">sheet</span>-beam current density ∼1 kA/cm{sup 2} from pseudospark based argon <span class="hlt">plasma</span> for pulse length of ∼200 ns in a single shot experiment. For the qualitative assessment of the <span class="hlt">sheet</span>-beam, an arrangement of three isolated metallic-<span class="hlt">sheets</span> is proposed. The actual shape and size of the <span class="hlt">sheet-electron</span>-beam are obtained through a non-conventional method by proposing a dielectric charging technique and scanning <span class="hlt">electron</span> microscope based imaging. As distinct from the earlier developed <span class="hlt">sheet</span> beam sources, the generated <span class="hlt">sheet</span>-beam has been propagated more than 190 mm distance in a drift space region maintaining <span class="hlt">sheet</span> structure without assistance of any external magnetic field.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/22303433','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/22303433"><span><span class="hlt">Electron</span> distributions observed with Langmuir waves in the <span class="hlt">plasma</span> <span class="hlt">sheet</span> boundary layer</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Hwang, Junga; Rha, Kicheol; Seough, Jungjoon; Yoon, Peter H.</p> <p>2014-09-15</p> <p>The present paper investigates the Langmuir turbulence driven by counter-streaming <span class="hlt">electron</span> beams and its plausible association with observed features in the Earth's <span class="hlt">plasma</span> <span class="hlt">sheet</span> boundary layer region. A one-dimensional electrostatic particle-in-cell simulation code is employed in order to simulate broadband electrostatic waves with characteristic frequency in the vicinity of the <span class="hlt">electron</span> <span class="hlt">plasma</span> frequency ω/ω{sub pe}≃1.0. The present simulation confirms that the broadband electrostatic waves may indeed be generated by the counter-streaming <span class="hlt">electron</span> beams. It is also found that the observed feature associated with low energy <span class="hlt">electrons</span>, namely quasi-symmetric velocity space plateaus, are replicated according to the present simulation. However, the present investigation only partially succeeds in generating the suprathermal tails such that the origin of observed quasi power-law energetic population formation remains outstanding.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015AGUFMSM14A..04K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015AGUFMSM14A..04K"><span>The Major Pathways of the <span class="hlt">Plasma</span> <span class="hlt">Sheet</span> <span class="hlt">Electrons</span> Precipitated in the Regions of Diffuse Aurora</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Khazanov, G. V.</p> <p>2015-12-01</p> <p>The precipitation of high-energy magnetospheric <span class="hlt">electrons</span> (E ~ 600eV - 10 KeV) in the diffuse aurora contributes significant energy flux into the Earth's ionosphere. It has been found (Khazanov et al. [2014, 2015]) that in order to fully understand the formation of this flux at the upper ionospheric boundary, ~ 700 - 800 km, it is important to consider the coupled ionosphere-magnetosphere system. In the diffuse aurora, precipitating <span class="hlt">electrons</span> initially injected from the <span class="hlt">plasma</span> <span class="hlt">sheet</span> via wave-particle interaction processes degrade in the atmosphere toward lower energies and produce secondary <span class="hlt">electrons</span> via impact ionization of the neutral atmosphere. These initially precipitating <span class="hlt">electrons</span> of magnetospheric origin can be additionally reflected back into the magnetosphere by the two magnetically conjugated atmospheres, leading to a series of multiple reflections that can greatly influence the initially precipitating flux at the upper ionospheric boundary (700-800 km) and the resultant population of secondary <span class="hlt">electrons</span> and <span class="hlt">electrons</span> cascading toward lower energies. In this talk we present the solution of the Boltzman-Landau kinetic equation that uniformly describes the entire <span class="hlt">electron</span> distribution function in the diffuse aurora, including the affiliated production of secondary <span class="hlt">electrons</span> (E < 600eV) and their energy interplay in the magnetosphere and two conjugated ionospheres. This solution takes into account, for the first time, formation <span class="hlt">electron</span> distribution function in the region of diffuse aurora starting with the primary injection of <span class="hlt">plasma</span> <span class="hlt">sheet</span> <span class="hlt">electrons</span> via both <span class="hlt">electron</span> cyclotron harmonic waves and whistler mode chorus waves to the loss cone, and their follow up multiple atmospheric reflections in the two magnetically conjugated ionospheres. It is demonstrated that magnetosphere-ionosphere coupling is the key element in the formation of <span class="hlt">electron</span> distribution function in the region of diffuse aurora.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016JGRA..121.9985G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016JGRA..121.9985G"><span>Origin of low proton-to-<span class="hlt">electron</span> temperature ratio in the Earth's <span class="hlt">plasma</span> <span class="hlt">sheet</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Grigorenko, E. E.; Kronberg, E. A.; Daly, P. W.; Ganushkina, N. Yu.; Lavraud, B.; Sauvaud, J.-A.; Zelenyi, L. M.</p> <p>2016-10-01</p> <p>We study the proton-to-<span class="hlt">electron</span> temperature ratio (Tp/Te) in the <span class="hlt">plasma</span> <span class="hlt">sheet</span> (PS) of the Earth's magnetotail using 5 years of Cluster observations (2001-2005). The PS intervals are searched within a region defined with -19 < X ≤ -7 RE and |Y| < 15 RE (GSM) under the condition |BX| ≤ 10 nT. One hundred sixty PS crossings are identified. We find an average value of <Tp/Te> 6.0. However, in many PS intervals Tp/Te varies over a wide range from a few units to several tens of units. In 86 PS intervals the Tp/Te decreases below 3.5. Generally, the decreases of Tp/Te are due to some increase of Te while Tp either decreases or remains unchanged. In the majority of these intervals the Tp/Te drops are observed during magnetotail dipolarizations. A superposed epoch analysis applied to these events shows that the minimum value of Tp/Te is observed after the dipolarization onset during the "turbulent phase" of dipolarization, when a number of transient BZ pulses are reduced, but the value of BZ is still large and an intensification of wave activity is observed. The Tp/Te drops, and associated increases of Te often coincide either with bursts of broadband electrostatic emissions, which may include <span class="hlt">electron</span> cyclotron harmonics, or with broadband electromagnetic emission in a frequency range from proton <span class="hlt">plasma</span> frequency (fpp) up to the <span class="hlt">electron</span> gyrofrequency (fce). These findings show that the wave activity developing in the current <span class="hlt">sheet</span> after dipolarization onset may play a role in the additional <span class="hlt">electron</span> heating and the associated Tp/Te decrease.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1990PhDT.......126P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1990PhDT.......126P"><span>The Inner Edge of the <span class="hlt">Plasma</span> <span class="hlt">Sheet</span>, REGION-2 Currents, and <span class="hlt">Electron</span> Precipitation: <span class="hlt">Plasma</span> Observations from ISEE 1.</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Paterson, William Russell</p> <p>1990-01-01</p> <p>On 17 April, 29 April, and 4 June of 1978 the ISEE 1 spacecraft encountered the inner edge of the <span class="hlt">plasma</span> <span class="hlt">sheet</span> on the dusk side of Earth at radial distances of 6 to 9 R_{rm E}. Measurements obtained with a <span class="hlt">plasma</span> analyzer aboard this spacecraft are examined in an effort to determine the source of Region -2 Birkeland currents. Near the inner edge it is found that the distributions of both <span class="hlt">electrons</span> and positive ions have low-energy field-aligned components that apparently originate at low altitudes. In two cases it is also found that the low-energy <span class="hlt">electrons</span> carry a current that is consistent in direction and magnitude with Region-2 currents observed at low altitude. Positive ions with energies per charge _sp{~}{<}1 kV also stream along the field and sometimes provide a current that is comparable in magnitude but opposite in direction to the <span class="hlt">electron</span> current. The low-energy <span class="hlt">electrons</span> are counterstreaming and appear to be backscattered secondaries produced by precipitation of keV <span class="hlt">plasma</span> <span class="hlt">sheet</span> <span class="hlt">electrons</span> into the atmosphere. The source of low-energy ions is not determined but is probably related to the <span class="hlt">electron</span> flow, possibly by wave-particle interactions. An analysis of <span class="hlt">electron</span> distributions indicates that the inner edge is a drift boundary separating open and closed flow trajectories. However, shielding there is found to be more localized than the shielding assumed in standard convection models. This shielding may be provided by the low-energy field-aligned <span class="hlt">plasmas</span>. It is also found that the <span class="hlt">electron</span> distributions at the inner edge are strongly modified, apparently by pitch-angle diffusion which drives keV <span class="hlt">electrons</span> into the loss cone and scatters secondary <span class="hlt">electrons</span> out of the source cone, and modification of the distributions by pitch-angle diffusion may also play a role in producing the field-aligned currents. Thus, it is found that precipitation and pitch -angle diffusion play important roles in determining the structure of the inner magnetosphere and may serve</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/7174737','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/7174737"><span>Observations of correlated broadband electrostatic noise and <span class="hlt">electron</span>-cyclotron emissions in the <span class="hlt">plasma</span> <span class="hlt">sheet</span>. Technical report</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Roeder, J.L.; Angelopoulos, V.; Baumjohann, W.; Anderson, R.R.</p> <p>1991-11-15</p> <p>Electric field wave observations in the central <span class="hlt">plasma</span> <span class="hlt">sheet</span> of the earth's magnetosphere show the correlated occurrence of broadband electrostatic noise and electrostatic <span class="hlt">electron</span> cyclotron harmonic emissions. A model is proposed in which the broadband emissions are <span class="hlt">electron</span> acoustic waves generated by an observed low energy <span class="hlt">electron</span> beam, and the cyclotron emissions are generated by the hot <span class="hlt">electron</span> loss cone instability. The high degree of correlation between the two emissions is provided in the model by the presence of the cold <span class="hlt">electron</span> beam population, which allows both of the <span class="hlt">plasma</span> instabilities to grow.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19760033216&hterms=plasma+explained&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3Dplasma%2Bexplained','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19760033216&hterms=plasma+explained&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3Dplasma%2Bexplained"><span>Magnetospheric protons and <span class="hlt">electrons</span> encountered by the moon in the <span class="hlt">plasma</span> <span class="hlt">sheet</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Prakash, A.</p> <p>1975-01-01</p> <p>Results are summarized for a study of <span class="hlt">plasma-sheet</span> particles (and their flow) encountered by the moon during its passage through the geomagnetic tail. The study is based on analysis of data obtained with a modulated Faraday cup on board the lunar-anchored spacecraft Explorer 35. It is shown that the <span class="hlt">electrons</span> have a rapidly fluctuating non-Maxwellian energy distribution with a mean energy of several hundred <span class="hlt">electron</span> volts and a density of approximately 0.2 per cu cm. Protons with energies of the order of 1 keV were usually detected above the instrument background when flowing towards earth at about 200 km/sec. It is suggested that strong terrestrial polar winds during the early history of the earth-moon system could have caused some erosion of the front side of the moon and that the relative smoothness of the same side could be explained in terms of gravitational shielding by the earth from the interplanetary rock flux.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/22471841','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/22471841"><span>Influence of the initial parameters of the magnetic field and <span class="hlt">plasma</span> on the spatial structure of the electric current and <span class="hlt">electron</span> density in current <span class="hlt">sheets</span> formed in helium</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Ostrovskaya, G. V.; Markov, V. S.; Frank, A. G.</p> <p>2016-01-15</p> <p>The influence of the initial parameters of the magnetic field and <span class="hlt">plasma</span> on the spatial structure of the electric current and <span class="hlt">electron</span> density in current <span class="hlt">sheets</span> formed in helium <span class="hlt">plasma</span> in 2D and 3D magnetic configurations with X-type singular lines is studied by the methods of holographic interferometry and magnetic measurements. Significant differences in the structures of <span class="hlt">plasma</span> and current <span class="hlt">sheets</span> formed at close parameters of the initial <span class="hlt">plasma</span> and similar configurations of the initial magnetic fields are revealed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19840043372&hterms=IOWA&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3DIOWA','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19840043372&hterms=IOWA&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3DIOWA"><span>The <span class="hlt">plasma</span> <span class="hlt">sheet</span> boundary layer</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Eastman, T. E.; Frank, L. A.; Peterson, W. K.; Lennartsson, W.</p> <p>1984-01-01</p> <p>A spatially distinct, temporally variable, transition region between the magnetotail lobes and the central <span class="hlt">plasma</span> <span class="hlt">sheet</span> designated the <span class="hlt">plasma</span> <span class="hlt">sheet</span> boundary layer has been identified from a survey of particle spectra and three-dimensional distributions as sampled by the ISEE 1 LEPEDEA. The instrumentation and data presentation are described, and the signatures of the magnetotail <span class="hlt">plasma</span> regimes are presented and discussed for the central <span class="hlt">plasma</span> <span class="hlt">sheet</span> and lobe and the <span class="hlt">plasma</span> <span class="hlt">sheet</span> boundary layer. Comparisons of <span class="hlt">plasma</span> parameters and distribution fucntions are made and the evolution of ion velocity distributions within the <span class="hlt">plasma</span> <span class="hlt">sheet</span> boundary layer is discussed. The spatial distribution of the <span class="hlt">plasma</span> <span class="hlt">sheet</span> boundary layer is considered and ion composition measurements are presented.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19880052817&hterms=Beans&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3DBeans','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19880052817&hterms=Beans&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3DBeans"><span>Simulation of electrostatic turbulence in the <span class="hlt">plasma</span> <span class="hlt">sheet</span> boundary layer with <span class="hlt">electron</span> currents and bean-shaped ion beams</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Nishikawa, K.-I.; Frank, L. A.; Huang, C. Y.</p> <p>1988-01-01</p> <p><span class="hlt">Plasma</span> data from ISEE-1 show the presence of <span class="hlt">electron</span> currents as well as energetic ion beams in the <span class="hlt">plasma</span> <span class="hlt">sheet</span> boundary layer. Broadband electrostatic noise and low-frequency electromagnetic bursts are detected in the <span class="hlt">plasma</span> <span class="hlt">sheet</span> boundary layer, especially in the presence of strong ion flows, currents, and steep spacial gradients in the fluxes of few-keV <span class="hlt">electrons</span> and ions. Particle simulations have been performed to investigate electrostatic turbulence driven by a cold <span class="hlt">electron</span> beam and/or ion beams with a bean-shaped velocity distribution. The simulation results show that the counterstreaming ion beams as well as the counterstreaming of the cold <span class="hlt">electron</span> beam and the ion beam excite ion acoustic waves with a given Doppler-shifted real frequency. However, the effect of the bean-shaped ion velocity distributions reduces the growth rates of ion acoustic instability. The simulation results also show that the slowing down of the ion bean is larger at the larger perpendicular velocity. The wave spectra of the electric fields at some points of the simulations show turbulence generated by growing waves.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li class="active"><span>1</span></li> <li><a href="#" onclick='return showDiv("page_2");'>2</a></li> <li><a href="#" onclick='return showDiv("page_3");'>3</a></li> <li><a href="#" onclick='return showDiv("page_4");'>4</a></li> <li><a href="#" onclick='return showDiv("page_5");'>5</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_1 --> <div id="page_2" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_1");'>1</a></li> <li class="active"><span>2</span></li> <li><a href="#" onclick='return showDiv("page_3");'>3</a></li> <li><a href="#" onclick='return showDiv("page_4");'>4</a></li> <li><a href="#" onclick='return showDiv("page_5");'>5</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="21"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016JGRA..121.8343D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016JGRA..121.8343D"><span>Solar wind-driven variations of <span class="hlt">electron</span> <span class="hlt">plasma</span> <span class="hlt">sheet</span> densities and temperatures beyond geostationary orbit during storm times</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Dubyagin, S.; Ganushkina, N. Yu.; Sillanpää, I.; Runov, A.</p> <p>2016-09-01</p> <p>The empirical models of the <span class="hlt">plasma</span> <span class="hlt">sheet</span> <span class="hlt">electron</span> temperature and density on the nightside at distances between 6 and 11 RE are constructed based on Time History of Events and Macroscale Interactions During Substorms (THEMIS) particle measurements. The data set comprises ˜400 h of observations in the <span class="hlt">plasma</span> <span class="hlt">sheet</span> during geomagnetic storm periods. The equatorial distribution of the <span class="hlt">electron</span> density reveals a strong earthward gradient and a moderate variation with magnetic local time symmetric with respect to the midnight meridian. The <span class="hlt">electron</span> density dependence on the external driving is parameterized by the solar wind proton density averaged over 4 h and the southward component of interplanetary magnetic field (IMF BS) averaged over 6 h. The interval of the IMF integration is much longer than a typical substorm growth phase, and it rather corresponds to the geomagnetic storm main phase duration. The solar wind proton density is the main controlling parameter, but the IMF BS becomes of almost the same importance in the near-Earth region. The root-mean-square deviation between the observed and predicted <span class="hlt">plasma</span> <span class="hlt">sheet</span> density values is 0.23 cm-3, and the correlation coefficient is 0.82. The equatorial distribution of the <span class="hlt">electron</span> temperature has a maximum in the postmidnight to morning MLT sector, and it is highly asymmetric with respect to the local midnight. The <span class="hlt">electron</span> temperature model is parameterized by solar wind velocity (averaged over 4 h), IMF BS (averaged over 45 min), and IMF BN (northward component of IMF, averaged over 2 h). The solar wind velocity is a major controlling parameter, and IMF BS and BN are comparable in importance. In contrast to the density model, the <span class="hlt">electron</span> temperature shows higher correlation with the IMF BS averaged over ˜45 min (substorm growth phase time scale). The effect of BN manifests mostly in the outer part of the modeled region (r > 8RE). The influence of the IMF BS is maximal in the midnight to postmidnight MLT sector</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016GeoRL..43.6044G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016GeoRL..43.6044G"><span>Electric fields associated with small-scale magnetic holes in the <span class="hlt">plasma</span> <span class="hlt">sheet</span>: Evidence for <span class="hlt">electron</span> currents</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Goodrich, Katherine A.; Ergun, Robert E.; Stawarz, Julia E.</p> <p>2016-06-01</p> <p>We report observations of magnetic holes (MHs) in the near-Earth (8 RE to 12 RE) <span class="hlt">plasma</span> <span class="hlt">sheet</span> that have physical sizes perpendicular to the magnetic field (B) on the order of the ion Larmor radius (ρi) and, more importantly, have current layers less than ρi in thickness. Small-scale MHs can have >90% depletion in |B| and are commonly associated with the braking of bursty bulk flow events. The generation of MHs is often attributed to magnetohydrodynamic (MHD) instabilities, which requires a size greater than ρi; the depletion in |B| is from an ion current consistent with a pressure gradient. Electric field (E) observations indicate a negative potential inside of small-scale MHs that creates an outward E at the boundary, which drives an E × B <span class="hlt">electron</span> current in a thin layer. These observations indicate that a Hall <span class="hlt">electron</span> current is primarily responsible for the depletion of |B| in small-scale magnetic holes, rather than the ion pressure gradient.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2011JGRA..116.6215J','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011JGRA..116.6215J"><span>A statistical study of the inner edge of the <span class="hlt">electron</span> <span class="hlt">plasma</span> <span class="hlt">sheet</span> and the net convection potential as a function of geomagnetic activity</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Jiang, F.; Kivelson, M. G.; Walker, R. J.; Khurana, K. K.; Angelopoulos, V.; Hsu, T.</p> <p>2011-06-01</p> <p>A widely accepted explanation of the location of the inner edge of the <span class="hlt">electron</span> <span class="hlt">plasma</span> <span class="hlt">sheet</span> and its dependence on <span class="hlt">electron</span> energy is based on drift motions of individual particles. The boundary is identified as the separatrix between drift trajectories linking the tail to the dayside magnetopause (open paths) and trajectories closed around the Earth. A statistical study of the inner edge of the <span class="hlt">electron</span> <span class="hlt">plasma</span> <span class="hlt">sheet</span> using THEMIS Electrostatic Analyzer <span class="hlt">plasma</span> data from November 2007 to April 2009 enabled us to examine this model. Using a dipole magnetic field and a Volland-Stern electric field with shielding, we find that a steady state drift boundary model represents the average location of the <span class="hlt">electron</span> <span class="hlt">plasma</span> <span class="hlt">sheet</span> boundary and reflects its variation with the solar wind electric field in the local time region between 21:00 and 06:00, except at high activity levels. However, the model does not reproduce the observed energy dispersion of the boundaries. We have also used the location of the inner edge of the <span class="hlt">electron</span> <span class="hlt">plasma</span> <span class="hlt">sheet</span> to parameterize the potential drop of the tail convection electric field as a function of solar wind electric field (Esw) and geomagnetic activity. The range of Esw examined is small because the data were acquired near solar minimum. For the range of values tested (meaningful statistics only for Esw < 2 mV/m), reasonably good agreement is found between the potential drop of the tail convection electric field inferred from the location of the inner edge and the polar cap potential drop calculated from the model of Boyle et al. (1997).</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/820113','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/820113"><span>MHD Ballooning Instability in the <span class="hlt">Plasma</span> <span class="hlt">Sheet</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>C.Z. Cheng; S. Zaharia</p> <p>2003-10-20</p> <p>Based on the ideal-MHD model the stability of ballooning modes is investigated by employing realistic 3D magnetospheric equilibria, in particular for the substorm growth phase. Previous MHD ballooning stability calculations making use of approximations on the <span class="hlt">plasma</span> compressibility can give rise to erroneous conclusions. Our results show that without making approximations on the <span class="hlt">plasma</span> compressibility the MHD ballooning modes are unstable for the entire <span class="hlt">plasma</span> <span class="hlt">sheet</span> where beta (sub)eq is greater than or equal to 1, and the most unstable modes are located in the strong cross-tail current <span class="hlt">sheet</span> region in the near-Earth <span class="hlt">plasma</span> <span class="hlt">sheet</span>, which maps to the initial brightening location of the breakup arc in the ionosphere. However, the MHD beq threshold is too low in comparison with observations by AMPTE/CCE at X = -(8 - 9)R(sub)E, which show that a low-frequency instability is excited only when beq increases over 50. The difficulty is mitigated by considering the kinetic effects of ion gyrorad ii and trapped <span class="hlt">electron</span> dynamics, which can greatly increase the stabilizing effects of field line tension and thus enhance the beta(sub)eq threshold [Cheng and Lui, 1998]. The consequence is to reduce the equatorial region of the unstable ballooning modes to the strong cross-tail current <span class="hlt">sheet</span> region where the free energy associated with the <span class="hlt">plasma</span> pressure gradient and magnetic field curvature is maximum.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010AGUFMSM41C1880J','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010AGUFMSM41C1880J"><span>Magnetospheric convection strength inferred from inner edge of the <span class="hlt">electron</span> <span class="hlt">plasma</span> <span class="hlt">sheet</span> and its relation to the polar cap potential drop</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Jiang, F.; Kivelson, M. G.; Walker, R. J.; Khurana, K. K.; Angelopoulos, V.</p> <p>2010-12-01</p> <p>The sharp inner edge of the nightside <span class="hlt">electron</span> <span class="hlt">plasma</span> <span class="hlt">sheet</span> observed by the THEMIS spacecraft is shown to provide a measure of the effective convection strength that transports <span class="hlt">plasma</span> <span class="hlt">sheet</span> <span class="hlt">plasma</span> into the inner magnetosphere. The effective convection strength is characterized by the difference of potential between the magnetopause terminators at dawn and at dusk. We have surveyed inner boundary crossings of the <span class="hlt">electron</span> <span class="hlt">plasma</span> <span class="hlt">sheet</span> measured by three THEMIS probes on orbits from Nov. 2007 to Apr. 2009. The values of the convection electric potential are inferred from the locations of the inner edge for different energy channels using a steady-state drift boundary model with a dipole magnetic field and a Volland-Stern electric field. When plotted against the solar wind electric field ( ), the convection electric potential is found to have a quasi-linear relationship with the driving solar wind electric field for the range of values tested (meaningful statistics only for Esw < 1.5 mV/m). Reasonably good agreement is found between the convection electric potential and the polar-cap potential drop calculated from model of Boyle et al. [1997] when the degree of shielding in the Volland-Stern potential is selected as gamma=1.5.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/6392866','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/6392866"><span>Energetic ion composition of the <span class="hlt">plasma</span> <span class="hlt">sheet</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Peterson, W.K.; Sharp, R.D.; Shelley, E.G.; Johnson, R.G.; Balsiger, H.</p> <p>1981-02-01</p> <p>Data obtained from the energetic ion mass spectrometer experiment on Isee 1 in the distant <span class="hlt">plasma</span> <span class="hlt">sheet</span> are presented. These data show that (1) the <span class="hlt">plasma</span> <span class="hlt">sheet</span> has a significant and variable ionospheric component (H/sup +/ and O/sup +/) representing from 10% to more than 50% of the total number density and (2) there is more than one process responsible for the energization of solar wind <span class="hlt">plasma</span> (H/sup +/ and He/sup + +/) to <span class="hlt">plasma</span> <span class="hlt">sheet</span> energies.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19810040197&hterms=balsiger&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3Dbalsiger','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19810040197&hterms=balsiger&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3Dbalsiger"><span>Energetic ion composition of the <span class="hlt">plasma</span> <span class="hlt">sheet</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Peterson, W. K.; Sharp, R. D.; Shelley, E. G.; Johnson, R. G.; Balsiger, H.</p> <p>1981-01-01</p> <p>Data obtained from the energetic ion mass spectrometer experiment on Isee 1 in the distant <span class="hlt">plasma</span> <span class="hlt">sheet</span> are presented. These data show that (1) the <span class="hlt">plasma</span> <span class="hlt">sheet</span> has a significant and variable ionospheric component (H(+) and O(+)) representing from 10% to more than 50% of the total number density and (2) there is more than one process responsible for the energization of solar wind <span class="hlt">plasma</span> (H(+) and He(++)) to <span class="hlt">plasma</span> <span class="hlt">sheet</span> energies.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19920034377&hterms=IRM&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3DIRM','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19920034377&hterms=IRM&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3DIRM"><span>On the thermodynamics of the <span class="hlt">plasma</span> <span class="hlt">sheet</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Baumjohann, W.; Goertz, C. K.</p> <p>1991-01-01</p> <p>The present study reinvestigates the evidence for nonadiabatic transport in the quiet central <span class="hlt">plasma</span> <span class="hlt">sheet</span>, using AMPTE IRM data from the <span class="hlt">plasma</span> <span class="hlt">sheet</span> boundary layer and active times selected on the basis of large AE values. It is found that as the <span class="hlt">plasma</span> is transported from the <span class="hlt">plasma</span> <span class="hlt">sheet</span> boundary layer into the central <span class="hlt">plasma</span> <span class="hlt">sheet</span>, both its temperature and its density (n) increase. The <span class="hlt">plasma</span> obeys the relation p varies as n exp 4/3 for quiet times (AE is less than 100 nT) and p varies as n exp 5/3 for AE greater than 300 nT. The temperature in the quiet <span class="hlt">plasma</span> <span class="hlt">sheet</span> is usually less than 6 keV, and high-temperature values are more likely to be observed in what is defined as the active <span class="hlt">plasma</span> <span class="hlt">sheet</span>. It is suggested that the <span class="hlt">plasma</span> <span class="hlt">sheet</span> contains a mixture of high-entropy 'bubbles' and low-entropy 'blobs.' It is argued that these either merge or are lost from the tail before they are convected into the near-earth tail.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013AGUFMSM51B2178L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013AGUFMSM51B2178L"><span>The Effects of Non-adiabatic Processes on Near-Earth <span class="hlt">Plasma</span> <span class="hlt">Sheet</span> <span class="hlt">Electrons</span> for Different Substorm-Related Magnetotail Conditions</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Liang, H.; Ashour-Abdalla, M.; Richard, R. L.; Schriver, D.; El-Alaoui, M.; Walker, R. J.</p> <p>2013-12-01</p> <p>We investigate the spatial evolution of energetic <span class="hlt">electron</span> distribution functions in the near-Earth <span class="hlt">plasma</span> <span class="hlt">sheet</span> associated with earthward propagating dipolarization fronts by using in situ observations as well as magnetohydrodynamic (MHD) and large scale kinetic (LSK) simulations. We have investigated two substorms, one on February 15, 2008 and the other on August 15, 2001. The February 15 event was observed by one of the THEMIS spacecraft at X_{GSM} -10RE, while the August 15 event was observed by Cluster at X -18RE. Both the MHD and LSK simulation results are compared to these spacecraft observations. Earthward propagating dipolarization fronts are found in both the observations and the MHD simulations, which exhibit very different magnetotail configurations, with contrasting flows, magnetic reconnection configuration, and <span class="hlt">plasma</span> <span class="hlt">sheet</span> structure. <span class="hlt">Electron</span> LSK simulations were performed by using the time-varying magnetic and electric fields from the global MHD simulations. For the February 15, 2008 event, the <span class="hlt">electrons</span> were launched near X = -20 RE with a thermal energy of 1 keV and for August 15, 2001 event, they were launched at 4 keV near X = -22 RE. These <span class="hlt">electrons</span> undergo both non-adiabatic acceleration near the magnetotail reconnection region and adiabatic acceleration as they propagate earthward from the launch region. We compute the <span class="hlt">electron</span> distribution functions parallel and perpendicular to the magnetic field at different locations between X = -18 RE and X = -10 RE in the <span class="hlt">plasma</span> <span class="hlt">sheet</span>. We find that for the February 15, 2008 event, reconnection is localized with a narrow region of high-speed flows ( 300 km/s). For this event the distribution functions show mainly f(v_perp) > f(v_par) ("par" and "perp" correspond to parallel and perpendicular to magnetic field). On August 15, 2001, there is a neutral line extending across the tail with relatively low-speed flows ( 100 km/s). For this event the distribution functions show mainly f(v_par) > f(v_perp). The</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012JGRA..117.6228P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012JGRA..117.6228P"><span>Kinetic ballooning/interchange instability in a bent <span class="hlt">plasma</span> <span class="hlt">sheet</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Panov, E. V.; Nakamura, R.; Baumjohann, W.; Kubyshkina, M. G.; Artemyev, A. V.; Sergeev, V. A.; Petrukovich, A. A.; Angelopoulos, V.; Glassmeier, K.-H.; McFadden, J. P.; Larson, D.</p> <p>2012-06-01</p> <p>We use Time History of Events and Macroscale Interactions during Substorms (THEMIS) and GOES observations to investigate the <span class="hlt">plasma</span> <span class="hlt">sheet</span> evolution on 28 February 2008 between 6:50 and 7:50 UT, when there developed strong magnetic field oscillations with periods of 100 s. Using multispacecraft analysis of the <span class="hlt">plasma</span> <span class="hlt">sheet</span> observations and an empirical <span class="hlt">plasma</span> <span class="hlt">sheet</span> model, we determine both the large-scale evolution of the <span class="hlt">plasma</span> <span class="hlt">sheet</span> and the properties of the oscillations. We found that the oscillations exhibited signatures of kinetic ballooning/interchange instability fingers that developed in a bent current <span class="hlt">sheet</span>. The interchange oscillations had a sausage structure, propagated duskward at a velocity of about 100 km/s, and were associated with fast radial <span class="hlt">electron</span> flows. We suggest that the observed negative gradient of the ZGSM magnetic field component (∂BZ/∂X) was a free energy source for the kinetic ballooning/interchange instability. Tens of minutes later a fast elongation of ballooning/interchange fingers was detected between 6 and 16 RE downtail with the length-to-width ratio exceeding 20. The finger elongation ended with signatures of reconnection in an embedded current <span class="hlt">sheet</span> near the bending point. These observations suggest a complex interplay between the midtail and near-Earth <span class="hlt">plasma</span> <span class="hlt">sheet</span> dynamics, involving localized fluctuations in both cross-tail and radial directions before current <span class="hlt">sheet</span> reconnection.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1996PSST....5..416S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1996PSST....5..416S"><span>Extraction characteristics of ? ions in a magnetized <span class="hlt">sheet</span> <span class="hlt">plasma</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Sanchez, Jose Karl Charles D.; Ramos, Henry J.</p> <p>1996-08-01</p> <p>A <span class="hlt">sheet</span> <span class="hlt">plasma</span> of thickness several millimetres was produced by a combination of a pair of strong dipole magnets with opposing fields and a pair of Helmholtz coils producing a magnetic mirror field. A ferrite magnet and a coreless magnetic coil encased within the limiters add to the mirror field, enhancing quiescence in the <span class="hlt">plasma</span>. The negative hydrogen ions produced in the peripheral region of the <span class="hlt">sheet</span> <span class="hlt">plasma</span> were extracted with a 0963-0252/5/3/009/img2 deflection mass spectrometer. Maximum negative ion current of about 0.9 0963-0252/5/3/009/img3A for an initial gas filling pressure of 3 mTorr was observed when the <span class="hlt">plasma</span> electrode was negatively biased near the value of the <span class="hlt">plasma</span> potential and when the mass spectrometer coil current generated a B field intensity equal to 691 G. The ratio of the negative ion density and the <span class="hlt">electron</span> density near the extraction electrode was relatively high at 0.276. The measured <span class="hlt">electron</span> temperature showed the existence of high-energy <span class="hlt">electrons</span> in the <span class="hlt">sheet</span> <span class="hlt">plasma</span>. The extracted negative hydrogen current density of 0963-0252/5/3/009/img4 is higher than what has been obtained from similar sources. The bulk <span class="hlt">electron</span> temperature and density at the centre of the <span class="hlt">sheet</span> <span class="hlt">plasma</span> were measured to be 11.06 eV and 0963-0252/5/3/009/img5, respectively.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2001JGR...106.8381S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2001JGR...106.8381S"><span>Rapid flux transport and <span class="hlt">plasma</span> <span class="hlt">sheet</span> reconfiguration</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Schödel, R.; Nakamura, R.; Baumjohann, W.; Mukai, T.</p> <p>2001-05-01</p> <p>On the basis of 3 1/2 years of Geotail data we examine typical <span class="hlt">plasma</span> <span class="hlt">sheet</span> reconfigurations that are observed during rapid flux transport events (RFTs) in the central <span class="hlt">plasma</span> <span class="hlt">sheet</span>. RFTs are bursts of rapid earthward or tailward <span class="hlt">plasma</span> flow with a large flux transport rate, EC=[(VXBZ)2+(VYBZ)2]1/2>2mVm-1. A superposed epoch analysis shows that earthward RFTs are related to nonadiabatic heating, dipolarization, and thickening of the <span class="hlt">plasma</span> <span class="hlt">sheet</span>, features typically seen during substorm expansion phase. The average earthward velocity component of the RFTs decreases toward Earth, whereas the average convection electric field, VXBZ, is practically independent of radial distance. Earthward RFTs show characteristics of bubbles, i.e., flux tubes with lower ion density and slightly higher magnetic field strength than the surrounding medium. Tailward RFTs beyond a radial distance of ~20RE can be associated either with a northward or a southward magnetic field, and their signatures show that they are probably related to the leading and trailing edges of tailward ejected plasmoids. Inside of 20RE, yet another type of tailward RFTs with BZ>0 can be observed. These events are possibly signatures of vortices or rebouncing flows in the near-Earth <span class="hlt">plasma</span> <span class="hlt">sheet</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19840051849&hterms=electric+energy&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3Delectric%2Benergy','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19840051849&hterms=electric+energy&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3Delectric%2Benergy"><span>Relationship of dusk sector radial electric field to energy dispersion at the inner edge of the <span class="hlt">electron</span> <span class="hlt">plasma</span> <span class="hlt">sheet</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Horwitz, J. L.</p> <p>1984-01-01</p> <p>It is shown that, by assuming that the magnetospheric particle boundaries are the result of steady state convection, the <span class="hlt">electron</span> boundaries in the dusk sector are essentially sensitive to the local, not the global, electric field configuration. A simple, direct relationship is obtained between the dusk sector radial electric field and the inner edge of <span class="hlt">electron</span> boundaries at various energies.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19850029387&hterms=environnement+international&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3Denvironnement%2Binternational','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19850029387&hterms=environnement+international&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3Denvironnement%2Binternational"><span>Particle and field characteristics of the high-latitude <span class="hlt">plasma</span> <span class="hlt">sheet</span> boundary layer</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Parks, G. K.; Mccarthy, M.; Fitzenreiter, R. J.; Ogilvie, K. W.; Etcheto, J.; Anderson, K. A.; Lin, R. P.; Anderson, R. R.; Eastman, T. E.; Frank, L. A.</p> <p>1984-01-01</p> <p>Particle and field data obtained by eight ISEE spacecraft experiments are used to define more precisely the characteristics of the high-latitude boundary region of the <span class="hlt">plasma</span> <span class="hlt">sheet</span>. A region immediately adjacent to the high-latitude <span class="hlt">plasma</span> <span class="hlt">sheet</span> boundary has particle and field characteristics distinctly different from those observed in the lobe and deeper in the central <span class="hlt">plasma</span> <span class="hlt">sheet</span>. <span class="hlt">Electrons</span> over a broad energy interval are 'field-aligned' and bidirectional, whereas in the <span class="hlt">plasma</span> <span class="hlt">sheet</span> the distributions are more isotropic. The region supports intense ion flows, large-amplitude electric fields, and enhanced broad-band electrostatic noise.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/1340970','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/1340970"><span>Energy limits of <span class="hlt">electron</span> acceleration in the <span class="hlt">plasma</span> <span class="hlt">sheet</span> during substorms: A case study with the Magnetospheric Multiscale (MMS) mission</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Turner, Drew Lawson; Fennell, J. F.; Blake, J. B.; Clemmons, J. H.; Mauk, B. H.; Cohen, I. J.; Jaynes, A. N.; Craft, J. V.; Wilder, F. D.; Baker, D. N.; Reeves, Geoffrey D.; Gershman, D. J.; Avanov, L. A.; Dorelli, J. C.; Giles, B. L.; Pollock, C. J.; Schmid, D.; Nakamura, R.; Strangeway, R. J.; Russell, C. T.; Artemyev, A. V.; Runov, A.; Angelopoulos, V.; Spence, H. E.; Torbert, R. B.; Burch, J. L.</p> <p>2016-08-01</p> <p>Here, we present multipoint observations of earthward moving dipolarization fronts and energetic particle injections from NASA's Magnetospheric Multiscale mission with a focus on <span class="hlt">electron</span> acceleration. From a case study during a substorm on 02 August 2015, we find that <span class="hlt">electrons</span> are only accelerated over a finite energy range, from a lower energy threshold at ~7–9 keV up to an upper energy cutoff in the hundreds of keV range. At energies lower than the threshold energy, <span class="hlt">electron</span> fluxes decrease, potentially due to precipitation by strong parallel electrostatic wavefields or initial sources in the lobes. <span class="hlt">Electrons</span> at energies higher than the threshold are accelerated cumulatively by a series of impulsive magnetic dipolarization events. This case demonstrates how the upper energy cutoff increases, in this case from ~130 keV to >500 keV, with each dipolarization/injection during sustained activity. We also present a simple model accounting for these energy limits that reveals that <span class="hlt">electron</span> energization is dominated by betatron acceleration.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/pages/biblio/1340970-energy-limits-electron-acceleration-plasma-sheet-during-substorms-case-study-magnetospheric-multiscale-mms-mission','SCIGOV-DOEP'); return false;" href="https://www.osti.gov/pages/biblio/1340970-energy-limits-electron-acceleration-plasma-sheet-during-substorms-case-study-magnetospheric-multiscale-mms-mission"><span>Energy limits of <span class="hlt">electron</span> acceleration in the <span class="hlt">plasma</span> <span class="hlt">sheet</span> during substorms: A case study with the Magnetospheric Multiscale (MMS) mission</span></a></p> <p><a target="_blank" href="http://www.osti.gov/pages">DOE PAGES</a></p> <p>Turner, Drew Lawson; Fennell, J. F.; Blake, J. B.; ...</p> <p>2016-08-01</p> <p>Here, we present multipoint observations of earthward moving dipolarization fronts and energetic particle injections from NASA's Magnetospheric Multiscale mission with a focus on <span class="hlt">electron</span> acceleration. From a case study during a substorm on 02 August 2015, we find that <span class="hlt">electrons</span> are only accelerated over a finite energy range, from a lower energy threshold at ~7–9 keV up to an upper energy cutoff in the hundreds of keV range. At energies lower than the threshold energy, <span class="hlt">electron</span> fluxes decrease, potentially due to precipitation by strong parallel electrostatic wavefields or initial sources in the lobes. <span class="hlt">Electrons</span> at energies higher than the thresholdmore » are accelerated cumulatively by a series of impulsive magnetic dipolarization events. This case demonstrates how the upper energy cutoff increases, in this case from ~130 keV to >500 keV, with each dipolarization/injection during sustained activity. We also present a simple model accounting for these energy limits that reveals that <span class="hlt">electron</span> energization is dominated by betatron acceleration.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016GeoRL..43.7785T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016GeoRL..43.7785T"><span>Energy limits of <span class="hlt">electron</span> acceleration in the <span class="hlt">plasma</span> <span class="hlt">sheet</span> during substorms: A case study with the Magnetospheric Multiscale (MMS) mission</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Turner, D. L.; Fennell, J. F.; Blake, J. B.; Clemmons, J. H.; Mauk, B. H.; Cohen, I. J.; Jaynes, A. N.; Craft, J. V.; Wilder, F. D.; Baker, D. N.; Reeves, G. D.; Gershman, D. J.; Avanov, L. A.; Dorelli, J. C.; Giles, B. L.; Pollock, C. J.; Schmid, D.; Nakamura, R.; Strangeway, R. J.; Russell, C. T.; Artemyev, A. V.; Runov, A.; Angelopoulos, V.; Spence, H. E.; Torbert, R. B.; Burch, J. L.</p> <p>2016-08-01</p> <p>We present multipoint observations of earthward moving dipolarization fronts and energetic particle injections from NASA's Magnetospheric Multiscale mission with a focus on <span class="hlt">electron</span> acceleration. From a case study during a substorm on 02 August 2015, we find that <span class="hlt">electrons</span> are only accelerated over a finite energy range, from a lower energy threshold at 7-9 keV up to an upper energy cutoff in the hundreds of keV range. At energies lower than the threshold energy, <span class="hlt">electron</span> fluxes decrease, potentially due to precipitation by strong parallel electrostatic wavefields or initial sources in the lobes. <span class="hlt">Electrons</span> at energies higher than the threshold are accelerated cumulatively by a series of impulsive magnetic dipolarization events. This case demonstrates how the upper energy cutoff increases, in this case from 130 keV to >500 keV, with each dipolarization/injection during sustained activity. We also present a simple model accounting for these energy limits that reveals that <span class="hlt">electron</span> energization is dominated by betatron acceleration.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/874183','DOE-PATENT-XML'); return false;" href="http://www.osti.gov/scitech/servlets/purl/874183"><span>Thermomechanical processing of <span class="hlt">plasma</span> sprayed intermetallic <span class="hlt">sheets</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Hajaligol, Mohammad R.; Scorey, Clive; Sikka, Vinod K.; Deevi, Seetharama C.; Fleischhauer, Grier; Lilly, Jr., A. Clifton; German, Randall M.</p> <p>2001-01-01</p> <p>A powder metallurgical process of preparing a <span class="hlt">sheet</span> from a powder having an intermetallic alloy composition such as an iron, nickel or titanium aluminide. The <span class="hlt">sheet</span> can be manufactured into electrical resistance heating elements having improved room temperature ductility, electrical resistivity, cyclic fatigue resistance, high temperature oxidation resistance, low and high temperature strength, and/or resistance to high temperature sagging. The iron aluminide has an entirely ferritic microstructure which is free of austenite and can include, in weight %, 4 to 32% Al, and optional additions such as .ltoreq.1% Cr, .gtoreq.0.05% Zr .ltoreq.2% Ti, .ltoreq.2% Mo, .ltoreq.1% Ni, .ltoreq.0.75% C, .ltoreq.0.1% B, .ltoreq.1% submicron oxide particles and/or electrically insulating or electrically conductive covalent ceramic particles, .ltoreq.1% rare earth metal, and/or .ltoreq.3% Cu. The process includes forming a non-densified metal <span class="hlt">sheet</span> by consolidating a powder having an intermetallic alloy composition such as by roll compaction, tape casting or <span class="hlt">plasma</span> spraying, forming a cold rolled <span class="hlt">sheet</span> by cold rolling the non-densified metal <span class="hlt">sheet</span> so as to increase the density and reduce the thickness thereof and annealing the cold rolled <span class="hlt">sheet</span>. The powder can be a water, polymer or gas atomized powder which is subjecting to sieving and/or blending with a binder prior to the consolidation step. After the consolidation step, the <span class="hlt">sheet</span> can be partially sintered. The cold rolling and/or annealing steps can be repeated to achieve the desired <span class="hlt">sheet</span> thickness and properties. The annealing can be carried out in a vacuum furnace with a vacuum or inert atmosphere. During final annealing, the cold rolled <span class="hlt">sheet</span> recrystallizes to an average grain size of about 10 to 30 .mu.m. Final stress relief annealing can be carried out in the B2 phase temperature range.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19950036505&hterms=current+sheet&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3Dcurrent%2Bsheet','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19950036505&hterms=current+sheet&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3Dcurrent%2Bsheet"><span>Nonlinear current <span class="hlt">sheet</span> formation in ideal <span class="hlt">plasmas</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Voge, A.; Schindler, K.; Otto, A.</p> <p>1994-01-01</p> <p>We present a numerical study of the formation of current <span class="hlt">sheets</span> in ideal <span class="hlt">plasmas</span>. First we confirm the development of singular current <span class="hlt">sheets</span> in a one-dimensional model. In a second step we extend the analysis to two-dimensional equilibria. Here it is found that the resulting structures are quiet insensitive to the boundary conditions. For the special case of a magnetotail like equilibrium it will be shown that the resulting current distribution provides a possibility to understand the onset of a localized anomalous resistivity from a macroscopic point of view. Furthermore, the resulting structures provide an explanation for the dramatic decrease of the thickness of the current <span class="hlt">sheet</span> in the magnetotail prior to the onset of geomagnetic substorms.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19950059028&hterms=nikolai&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3Dnikolai%2B2','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19950059028&hterms=nikolai&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3Dnikolai%2B2"><span>Birkeland currents in the <span class="hlt">plasma</span> <span class="hlt">sheet</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Tsyganenko, Nikolai A.; Stern, David P.; Kaymaz, Zerefsan</p> <p>1993-01-01</p> <p>A search was conducted for the signatures of Birkeland currents in the Earth's magnetic tail, using observed values of B(sub x) and B(sub y) from large sets of spacecraft data. The data were binned by x and y for -10 greater than x(sub GSM) greater than -35 and absolute value of y(sub GSM) less than or equal to 20 R(sub E) (less than or equal to 30 R(sub E) for x(sub GSM) less than or equal to -25 R(sub E)) and in each bin their distribution in the (B(sub x), B(sub y)) plane was fitted by least squares to a piecewise linear function. That gave average x-y distributions of the flaring angle between B(sub xy) and the x direction, as well as that angle's variation across the thickness of the <span class="hlt">plasma</span> <span class="hlt">sheet</span>. Angles obtained in the central <span class="hlt">plasma</span> <span class="hlt">sheet</span> differed from those derived near the lobe boundary. That is the expected signature if earthward or tailward Birkeland current <span class="hlt">sheets</span> are embedded in the <span class="hlt">plasma</span> <span class="hlt">sheet</span>, and from this dfiference we derived the dawn-dusk profiles of the tail Birkeland currents for several x(sub GSM) intervals. It was found that (1) the Birkeland currents have the sense of region 1 currents, when mapped to the ionosphere; (2) both the linear current density (kiloamperes/R(sub E)) and the net magnitude of the field-aligned currents decrease rapidly down the tail; (3) the total Birkeland current at x approximately equals -10 R(sub E) equals approximately equals 500-700 kA, which is approx. 30% of the net region 1 current observed at ionospheric altitudes, in agreement with model mapping results; and (4) the B(sub z) and B(sub y) components of the interplanetary magnetic field influence the distribution of Birkeland currents in the tail.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_1");'>1</a></li> <li class="active"><span>2</span></li> <li><a href="#" onclick='return showDiv("page_3");'>3</a></li> <li><a href="#" onclick='return showDiv("page_4");'>4</a></li> <li><a href="#" onclick='return showDiv("page_5");'>5</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_2 --> <div id="page_3" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_1");'>1</a></li> <li><a href="#" onclick='return showDiv("page_2");'>2</a></li> <li class="active"><span>3</span></li> <li><a href="#" onclick='return showDiv("page_4");'>4</a></li> <li><a href="#" onclick='return showDiv("page_5");'>5</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="41"> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/22489978','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/22489978"><span>Theoretical modeling of the <span class="hlt">plasma</span>-assisted catalytic growth and field emission properties of graphene <span class="hlt">sheet</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Sharma, Suresh C.; Gupta, Neha</p> <p>2015-12-15</p> <p>A theoretical modeling for the catalyst-assisted growth of graphene <span class="hlt">sheet</span> in the presence of <span class="hlt">plasma</span> has been investigated. It is observed that the <span class="hlt">plasma</span> parameters can strongly affect the growth and field emission properties of graphene <span class="hlt">sheet</span>. The model developed accounts for the charging rate of the graphene <span class="hlt">sheet</span>; number density of <span class="hlt">electrons</span>, ions, and neutral atoms; various elementary processes on the surface of the catalyst nanoparticle; surface diffusion and accretion of ions; and formation of carbon-clusters and large graphene islands. In our investigation, it is found that the thickness of the graphene <span class="hlt">sheet</span> decreases with the <span class="hlt">plasma</span> parameters, number density of hydrogen ions and RF power, and consequently, the field emission of <span class="hlt">electrons</span> from the graphene <span class="hlt">sheet</span> surface increases. The time evolution of the height of graphene <span class="hlt">sheet</span> with ion density and sticking coefficient of carbon species has also been examined. Some of our theoretical results are in compliance with the experimental observations.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014AGUFM.P42B..03S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014AGUFM.P42B..03S"><span>The State of the <span class="hlt">Plasma</span> <span class="hlt">Sheet</span> and Atmosphere at Europa</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Shemansky, D. E.; Yung, Y. L.; Liu, X.; Yoshii, J.; Hansen, C. J.; Hendrix, A.; Esposito, L. W.</p> <p>2014-12-01</p> <p>The Hall et al. (1995) report announcing the discovery of atomic oxygen FUV emission from Europa included a conclusion that the atmosphere was dominated by O2. Over the following 20 years publications referencing the atmosphere accepted this conclusion, and calculations of rates, particularly mass loading of the magnetosphere depended on a composition that was of order 90% O2. Analysis of the Europa emission spectrum in the present work, leads to the conclusion that the O I emission properties were misinterpreted. The interpretation of the source process depends on the ratio of the O I 1356 and 1304 A multiplet emissions (R(4:5) = (I(1356)/I(1304)). The value of R(4:5) never reaches the lower limit for <span class="hlt">electron</span> impact dissociation of O2 for any of the 7 recorded disk averaged measurements between 1994 and 2013. Analysis of the Cassini UVIS exposures show the 1304 A multiplet to be optically thick, and the emissions are modeled as direct <span class="hlt">electron</span> and solar photon excitation of O I. The result is a model atmosphere dominated by O I and O II, with neutral density a factor of 100 below the original O2 model. Other considerations show incompatibility with an O2 atmosphere. Deep exposures using the Cassini UVIS EUV spectrograph provide the state of the <span class="hlt">plasma</span> <span class="hlt">sheet</span> at Europa. The ion species are identified as mainly outwardly diffused mass from the Io <span class="hlt">plasma</span> torus with a minor contribution from Europa. <span class="hlt">Plasma</span> time-constants are of the order of 200 days. Neutral species in the <span class="hlt">plasma</span> <span class="hlt">sheet</span> are not measureable. The energy flux in the magnetosphere L-shells are mainly responsible for energy deposition maintaining the <span class="hlt">plasma</span> <span class="hlt">sheet</span>. The energy content in the Io and Europa L-shells, as measured, is similar, but the mean radiative cooling rate in the Io <span class="hlt">plasma</span> torus at the time of the Cassini encounter was 565 femtoergs cm-3 s-1, compared to 7.3 at Europa, reflecting the difference between an active and inactive planetary satellite, particularly considering the fact that most</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/5384282','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/5384282"><span>A pincer-shaped <span class="hlt">plasma</span> <span class="hlt">sheet</span> at Uranus</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Hammond, C.M.; Walker, R.J.; Kivelson, M.G. )</p> <p>1990-09-01</p> <p>A model from Voigt et al. (1987) and an MHD simulation from Walker et al. (1989) both show that the curvature of the <span class="hlt">plasma</span> <span class="hlt">sheet</span> at Uranus changes as the dipole tilt varies between 38{degree} and 22{degree}. The models suggest that one of the two partial traversals of the uranian <span class="hlt">plasma</span> <span class="hlt">sheet</span> made during the outbound trajectory of Voyager 2 can be explained as an entry into the highly curved <span class="hlt">plasma</span> <span class="hlt">sheet</span> that develops when Uranus is near the maximum dipole tilt value of 38{degree}; previously both partial traversals have been explained as anomalous. The spacecraft would have reversed its motion relative to the <span class="hlt">plasma</span> <span class="hlt">sheet</span> as the continued rotation diminished the dipole tilt and the retreating <span class="hlt">plasma</span> <span class="hlt">sheet</span> uncurled. As the dipole tilt approached its minimum value, spacecraft motion towards the neutral <span class="hlt">sheet</span> resumed and the traversal of the <span class="hlt">plasma</span> <span class="hlt">sheet</span> was completed. Evidence from the PWS <span class="hlt">plasma</span> wave detector suggests that the spacecraft trajectory skimmed the <span class="hlt">plasma</span> <span class="hlt">sheet</span> boundary layer for several hours prior to the partial immersion. The <span class="hlt">plasma</span> <span class="hlt">sheet</span> of the Voigt et al. model was not located near the spacecraft during this time interval. On the other hand, the MHD simulation reveals a <span class="hlt">plasma</span> <span class="hlt">sheet</span> that is more curved than in the Boigt et al. model; near maximum dipole tilt, the <span class="hlt">plasma</span> <span class="hlt">sheet</span> is pincer-shaped. The unusual geometry implies that Voyager 2 remained near the <span class="hlt">plasma</span> <span class="hlt">sheet</span> boundary layer during the period suggested by the PWS data. Thus the simulation accounts easily for the first of the <span class="hlt">plasma</span> <span class="hlt">sheet</span> encounters previously called anomalous. The second partial immersion remains anomalous, having previously been related to substorm activity, and thus is not discussed here. The stagnation distances of the earth and Uranus at the nose of the magnetopause were used to scale the Walker et al. (1989) simulation of the terrestrial magnetosphere to represent the uranian magnetosphere.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1988PhDT.......105L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1988PhDT.......105L"><span><span class="hlt">Plasma-Sheet</span> Dynamics Induced by <span class="hlt">Plasma</span> Mantle.</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Liu, Weining William</p> <p></p> <p>Is the magnetic field in the Earth's magnetotail static? if yes, why? if not, what causes the magnetic field to change and how does it evolve with time? These questions have haunted magnetospheric physicists for the past decade. Although significant progress has been made in this area of research, a consensus still does not exist. This thesis approaches the problem from the most fundamental basis--Faraday's law relating the curl of the electric field to the time variation of the magnetic field. If we can reach an independent theory that relates the electric field to the magnetic field, the whole problem can, at least in principle, be solved. This thesis pursues the problem both physically and mathematically. Our answers to the questions listed at the beginning are: (1) the magnetic field is generally not static; (2) the change is powered by the energy transfer from the solar wind to the magnetosphere, the agent that effects the change is <span class="hlt">plasma</span> injection from the high-latitude <span class="hlt">plasma</span> mantle; (3) the time-dependence is closely related to the velocity distribution of the mantle <span class="hlt">plasma</span>; A decrease of B_{rm z} in the near tail and a flux buildup at the farther end of tail are two primary features of the time evolution; (4) a dense, drifting <span class="hlt">plasma</span> mantle causes an intensive reconfiguration in the <span class="hlt">plasma</span> <span class="hlt">sheet</span> and is likely to lead to <span class="hlt">plasma</span> <span class="hlt">sheet</span> instability. The general results of the thesis are supportive of Hones' phenomenological model of the tail evolution (Hones, 1977).</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014APS..DPPPP8134D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014APS..DPPPP8134D"><span><span class="hlt">Plasma</span> Relaxation Dynamics Moderated by Current <span class="hlt">Sheets</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Dewar, Robert; Bhattacharjee, Amitava; Yoshida, Zensho</p> <p>2014-10-01</p> <p>Ideal magnetohydrodynamics (IMHD) is strongly constrained by an infinite number of microscopic constraints expressing mass, entropy and magnetic flux conservation in each infinitesimal fluid element, the latter preventing magnetic reconnection. By contrast, in the Taylor-relaxed equilibrium model all these constraints are relaxed save for global magnetic flux and helicity. A Lagrangian is presented that leads to a new variational formulation of magnetized fluid dynamics, relaxed MHD (RxMHD), all static solutions of which are Taylor equilibrium states. By postulating that some long-lived macroscopic current <span class="hlt">sheets</span> can act as barriers to relaxation, separating the <span class="hlt">plasma</span> into multiple relaxation regions, a further generalization, multi-relaxed MHD (MRxMHD), is developed. These concepts are illustrated using a simple two-region slab model similar to that proposed by Hahm and Kulsrud--the formation of an initial shielding current <span class="hlt">sheet</span> after perturbation by boundary rippling is calculated using MRxMHD and the final island state, after the current <span class="hlt">sheet</span> has relaxed through a reconnection sequence, is calculated using RxMHD. Australian Research Council Grant DP110102881.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016GeoRL..4311957C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016GeoRL..4311957C"><span>Seasonal variations in Saturn's <span class="hlt">plasma</span> <span class="hlt">sheet</span> warping</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Carbary, J. F.; Mitchell, D. G.</p> <p>2016-12-01</p> <p>Composite images of hydrogen and oxygen energetic neutral atoms (ENA) obtained from 2005 through 2015 from the Ion Neutral Camera on Cassini reveal the structure of Saturn's <span class="hlt">plasma</span> <span class="hlt">sheet</span> out to 40 Rs (1 Rs = 60,268 km). Seen from either the dawnside or duskside at low latitude, these composites reveal that the <span class="hlt">plasma</span> <span class="hlt">sheet</span> is concave upward (northward) near Saturn's southern solstice, has no concavity near equinox, and is concave downward (southward) near Saturn's northern solstice. This seasonal variation confirms the Arridge "bowl" model developed early in the Cassini mission based on limited magnetometer data, with the concavity depending on the tangent of the Sun's latitude at Saturn and a "hinge" parameter rH. The best fits to the ENA data indicate rH ≈ 25-30 Rs, which is close to the 29 Rs originally suggested by the magnetometer results. The bowl structure suggests other magnetodisks in the solar system and beyond may also undergo similar warping dynamics and may not have a "flat" geometry.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20000023162','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20000023162"><span><span class="hlt">Plasma</span> <span class="hlt">Sheet</span> Source and Loss Processes</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Lennartsson, O. W.</p> <p>2000-01-01</p> <p>Data from the TIMAS ion mass spectrometer on the Polar satellite, covering 15 ev/e to 33 keV/e in energy and essentially 4(pi) in view angles, are used to investigate the properties of earthward (sunward) field-aligned flows of ions, especially protons, in the <span class="hlt">plasma</span> <span class="hlt">sheet</span>-lobe transition region near local midnight. A total of 142 crossings of this region are analyzed at 12-sec time resolution, all in the northern hemisphere, at R(SM) approx. 4 - 7 R(sub E), and most (106) in the poleward (sunward) direction. Earthward proton flows are prominent in this transition region (greater than 50% of the time), typically appearing as sudden "blasts" with the most energetic protons (approx. 33 keV) arriving first with weak flux, followed by protons of decreasing energy and increasing flux until either: (1) a new "blast" appears, (2) the flux ends at a sharp boundary, or (3) the flux fades away within a few minutes as the mean energy drops to a few keV. Frequent step-like changes (less than 12 sec) of the flux suggest that perpendicular gradients on the scale of proton gyroradii are common. Peak flux is similar to central <span class="hlt">plasma</span> <span class="hlt">sheet</span> proton flux (10(exp 5) - 10(exp 6)/[cq cm sr sec keV/e] and usually occurs at E approx. 4 - 12 keV. Only the initial phase of each "blast" (approx. 1 min) displays pronounced field-alignment of the proton velocity distribution, consistent with the time-of-flight separation of a more or less isotropic source distribution with df/d(nu) less than 0. The dispersive signatures are often consistent with a source at R(SM) less than or equal to 30 R(sub E). No systematic latitudinal velocity dispersion is found, implying that the equatorial <span class="hlt">plasma</span> source is itself convecting. In short, the proton "blasts" appear as sudden local expansions of central <span class="hlt">plasma</span> <span class="hlt">sheet</span> particles along reconfigured ("dipolarized") magnetic field lines.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19860056276&hterms=last+field&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DTitle%26N%3D0%26No%3D70%26Ntt%3Dlast%2Bfield','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19860056276&hterms=last+field&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DTitle%26N%3D0%26No%3D70%26Ntt%3Dlast%2Bfield"><span>ISEE observations of the <span class="hlt">plasma</span> <span class="hlt">sheet</span> boundary, <span class="hlt">plasma</span> <span class="hlt">sheet</span>, and neutral <span class="hlt">sheet</span>. I - Electric field, magnetic field, <span class="hlt">plasma</span>, and ion composition</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Cattell, C. A.; Mozer, F. S.; Hones, E. W., Jr.; Anderson, R. R.; Sharp, R. D.</p> <p>1986-01-01</p> <p>The first simultaneous study of dc and ac electric and magnetic fields, E x B velocity, <span class="hlt">plasma</span> flows, ratio of <span class="hlt">plasma</span> to magnetic field pressure, total energy density, energetic particles, and ion composition from the ISEE satellites and ground and interplanetary magnetic fields has been made to determine (1) the relationship of the previously observed electric fields at the <span class="hlt">plasma</span> <span class="hlt">sheet</span> boundary and at the neutral <span class="hlt">sheet</span> to <span class="hlt">plasma</span> parameters, and (2) whether the phenomena occurring during quiet and active times were consistent with the formation of a near-earth neutral line during substorms or with the boundary layer model. Five observations made during the study of two substorms were seen to be in agreement with the neutral-line model. The observations are consistent with the satellite being located at varying distances from the neutral line and diffusion region where reconnection and <span class="hlt">plasma</span> acceleration were occurring. Although the z component (into or out of the ecliptic plane) of E x B convection was generally toward the neutral <span class="hlt">sheet</span>, there were examples when it was consistent with the inferred motion of the <span class="hlt">plasma</span> <span class="hlt">sheet</span> past the satellite. A synthesis of previous reports on large electric fields at the <span class="hlt">plasma</span> <span class="hlt">sheet</span> boundary and variable fields at the neutral <span class="hlt">sheet</span> including the associated <span class="hlt">plasma</span> flows is also described.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/25526132','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/25526132"><span>Bright subcycle extreme ultraviolet bursts from a single dense relativistic <span class="hlt">electron</span> <span class="hlt">sheet</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Ma, W J; Bin, J H; Wang, H Y; Yeung, M; Kreuzer, C; Streeter, M; Foster, P S; Cousens, S; Kiefer, D; Dromey, B; Yan, X Q; Meyer-ter-Vehn, J; Zepf, M; Schreiber, J</p> <p>2014-12-05</p> <p>Double-foil targets separated by a low density <span class="hlt">plasma</span> and irradiated by a petawatt-class laser are shown to be a copious source of coherent broadband radiation. Simulations show that a dense <span class="hlt">sheet</span> of relativistic <span class="hlt">electrons</span> is formed during the interaction of the laser with the tenuous <span class="hlt">plasma</span> between the two foils. The coherent motion of the <span class="hlt">electron</span> <span class="hlt">sheet</span> as it transits the second foil results in strong broadband emission in the extreme ultraviolet, consistent with our experimental observations.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/19518640','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/19518640"><span>Observations of double layers in earth's <span class="hlt">plasma</span> <span class="hlt">sheet</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Ergun, R E; Andersson, L; Tao, J; Angelopoulos, V; Bonnell, J; McFadden, J P; Larson, D E; Eriksson, S; Johansson, T; Cully, C M; Newman, D N; Goldman, M V; Roux, A; LeContel, O; Glassmeier, K-H; Baumjohann, W</p> <p>2009-04-17</p> <p>We report the first direct observations of parallel electric fields (E_{ parallel}) carried by double layers (DLs) in the <span class="hlt">plasma</span> <span class="hlt">sheet</span> of Earth's magnetosphere. The DL observations, made by the THEMIS spacecraft, have E_{ parallel} signals that are analogous to those reported in the auroral region. DLs are observed during bursty bulk flow events, in the current <span class="hlt">sheet</span>, and in <span class="hlt">plasma</span> <span class="hlt">sheet</span> boundary layer, all during periods of strong magnetic fluctuations. These observations imply that DLs are a universal process and that strongly nonlinear and kinetic behavior is intrinsic to Earth's <span class="hlt">plasma</span> <span class="hlt">sheet</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19900063368&hterms=plasma+explained&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3Dplasma%2Bexplained','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19900063368&hterms=plasma+explained&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3Dplasma%2Bexplained"><span>A pincer-shaped <span class="hlt">plasma</span> <span class="hlt">sheet</span> at Uranus</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Hammond, C. Max; Walker, Raymond J.; Kivelson, Margaret G.</p> <p>1990-01-01</p> <p>An MHD simulation of the terrestrial magnetosphere, rescaled to represent the Uranian magnetotail, is carried out. The 3p immersion can be explained in terms of possible extreme departures from average <span class="hlt">plasma</span> <span class="hlt">sheet</span> shapes in the Uranian magnetosphere. The orientation of the Uranian dipole and rotation axes produce a dynamically curved <span class="hlt">plasma</span> <span class="hlt">sheet</span> which is an unusual feature of the Uranian magnetosphere.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2008PhDT.......258H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2008PhDT.......258H"><span>Cluster multi-point observations of the magnetotail <span class="hlt">plasma</span> <span class="hlt">sheet</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Henderson, Paul David</p> <p></p> <p>This thesis presents observations of the terrestrial magnetotail <span class="hlt">plasma</span> <span class="hlt">sheet</span> made by the European Space Agency Cluster mission. The Cluster mission is composed of four identical spacecraft, the first such multi-spacecraft mission, and enables, for the first time, the disambiguation of time versus space phenomena. Using the data from 2003, when the spacecraft were at their smallest average separation to date, many small-scale processes, both microphysical and macrophysical, are investigated. In the first study presented, two small flux ropes, a possible signature of multiple X-line reconnection, are investigated. By the development and utilisation of various multi-spacecraft methods, the currents and magnetic forces internal and external to the flux ropes, as well as the internal structure of the flux ropes, are investigated. In addition, a theory of their early evolution is suggested. In the second study presented, various terms of the generalised Ohm's law for a <span class="hlt">plasma</span> are determined, including, for the first time, the divergence of the full <span class="hlt">electron</span> pressure tensor, during the passage past the spacecraft of an active reconnection X-line. It is found that the electric field contribution from the divergence of the <span class="hlt">electron</span> pressure tensor is anti-correlated with the contribution from the Hall term in the direction normal to the neutral <span class="hlt">sheet</span>. In addition, further signatures of reconnection are quantified, such as parallel electric field generation and Hall quadrupolar magnetic field and current systems. In the final study presented, the anti-correlation between the divergence of the <span class="hlt">electron</span> pressure tensor and Hall terms is investigated further. It is found that the anti-correlation is general, appearing in the direction normal to the neutral <span class="hlt">sheet</span> because of a cross tail current. In a simple magnetohydrostatic treatment, a force balance argument leads to the conclusion that the gradient of the anti-correlation is a function of the ratio of the <span class="hlt">electron</span> to ion</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19740032617&hterms=sub+surface+instruments&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3Dsub%2Bsurface%2Binstruments','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19740032617&hterms=sub+surface+instruments&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3Dsub%2Bsurface%2Binstruments"><span><span class="hlt">Plasma</span> <span class="hlt">sheet</span> at lunar distance - Characteristics and interactions with the lunar surface</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Rich, F. J.; Reasoner, D. L.; Burke, W. J.</p> <p>1973-01-01</p> <p>The <span class="hlt">plasma</span> <span class="hlt">sheet</span> at lunar distance is investigated with the use of data from the charged particle lunar environment experiment (CPLEE), complemented with data from the Explorer 35/ARC magnetometer. It is shown that the presence of the lunar surface does not appreciably affect measurements of the <span class="hlt">plasma</span> <span class="hlt">sheet</span> characteristics by the lunar-based CPLEE instrument. In particular, the lunar surface generally does not shadow <span class="hlt">plasma</span> <span class="hlt">sheet</span> particles. This may be due to rapid random passage (greater than 40 km/sec) of magnetotail field lines with respect to the lunar surface or to diffusion of <span class="hlt">plasma</span> <span class="hlt">sheet</span> <span class="hlt">electrons</span> into the flux tubes in contact with the lunar surface. The <span class="hlt">plasma</span> <span class="hlt">sheet</span> is generally observed as a rapid increase in observed particle fluxes and a simultaneous decrease in field strength. A statistical analysis of the CPLEE data shows that the <span class="hlt">plasma</span> <span class="hlt">sheet</span> in the midnight sector has a thickness of 5 R sub E plus or minus 2 R sub E. Geomagnetic activity reduces the probability of encounters between the moon and the <span class="hlt">plasma</span> <span class="hlt">sheet</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016JGRA..12110130T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016JGRA..12110130T"><span>Heliospheric <span class="hlt">plasma</span> <span class="hlt">sheet</span> (HPS) impingement onto the magnetosphere as a cause of relativistic <span class="hlt">electron</span> dropouts (REDs) via coherent EMIC wave scattering with possible consequences for climate change mechanisms</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Tsurutani, B. T.; Hajra, R.; Tanimori, T.; Takada, A.; Bhanu, R.; Mannucci, A. J.; Lakhina, G. S.; Kozyra, J. U.; Shiokawa, K.; Lee, L. C.; Echer, E.; Reddy, R. V.; Gonzalez, W. D.</p> <p>2016-10-01</p> <p>A new scenario is presented for the cause of magnetospheric relativistic <span class="hlt">electron</span> decreases (REDs) and potential effects in the atmosphere and on climate. High-density solar wind heliospheric plasmasheet (HPS) events impinge onto the magnetosphere, compressing it along with remnant noon-sector outer-zone magnetospheric 10-100 keV protons. The betatron accelerated protons generate coherent electromagnetic ion cyclotron (EMIC) waves through a temperature anisotropy (T⊥/T|| > 1) instability. The waves in turn interact with relativistic <span class="hlt">electrons</span> and cause the rapid loss of these particles to a small region of the atmosphere. A peak total energy deposition of 3 × 1020 ergs is derived for the precipitating <span class="hlt">electrons</span>. Maximum energy deposition and creation of <span class="hlt">electron</span>-ion pairs at 30-50 km and at < 30 km altitude are quantified. We focus the readers' attention on the relevance of this present work to two climate change mechanisms. Wilcox et al. (1973) noted a correlation between solar wind heliospheric current <span class="hlt">sheet</span> (HCS) crossings and high atmospheric vorticity centers at 300 mb altitude. Tinsley et al. has constructed a global circuit model which depends on particle precipitation into the atmosphere. Other possible scenarios potentially affecting weather/climate change are also discussed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2003APS..GECSRP025T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2003APS..GECSRP025T"><span>Observation of molecular assisted recombination in the magnetized <span class="hlt">sheet</span> <span class="hlt">plasma</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Tonegawa, Akira; Ogawa, Hironori; Yazawa, Hiroyuki; Ono, Masataka; Kawamura, Kazutaka</p> <p>2003-10-01</p> <p>Molecular assisted recombination (MAR) with vibrational hydorogen molecular has been observed to enhance the reduction of ion particle flux in a high density magnetized <span class="hlt">sheet</span> <span class="hlt">plasma</span> device (TPDSHEET-IV). There are two main paths for MAR: (1) H2(v) + e=> H- + H (dissociated attachment) followed by H- + H+ =>H + H (mutual neutralization), and (2) H2(v) + A+ => (AH)+ + H (ion conversion) followed by (AH)+ + e => A + H (dissociative recombination) , where A+(A) is a hydrogen or an impurity ion (atom) existing in the <span class="hlt">plasma</span>. The value of H+, H2+ and H3+ are observed in the mid-plane region with hot <span class="hlt">electron</span>(Te= 10-15 eV) by a mass-analyzer. On the other hand, negative ions of hydrogen atom H- is localized in the circumference of existing cold <span class="hlt">electrons</span> (Te= 3-5 eV) by a probe assisted laser photodetachment method. A small amount of secondary hydrogen gas puffing into a hydrogen <span class="hlt">plasma</span> decreased gradually the density of H2+, H3+ and increased rapidly H- in the <span class="hlt">plasma</span>, while the conventional radiation and three-body recombination (EIR) processes were disappeared. These results can be well explained by taking the MAR in the <span class="hlt">plasma</span> into account.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19880044581&hterms=transition+energy&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3Dtransition%2Benergy','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19880044581&hterms=transition+energy&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3Dtransition%2Benergy"><span>Energy spectra of <span class="hlt">plasma</span> <span class="hlt">sheet</span> ions and <span class="hlt">electrons</span> from about 50 eV/e to about 1 MeV during plamsa temperature transitions</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Christon, S. P.; Mitchell, D. G.; Williams, D. J.; Frank, L. A.; Huang, C. Y.; Eastman, T. E.</p> <p>1988-01-01</p> <p>ISEE-1 charged-particle measurements obtained during eight <span class="hlt">plasma</span> temperature transitions (PTTs) in 1978-1979 are compiled in tables and graphs and analyzed in detail, comparing the ion and <span class="hlt">electron</span> differential energy spectra with the predictions of theoretical models. PTTs are defined as approximately 1-h periods of low bulk <span class="hlt">plasma</span> velocity and steadily increasing or decreasing thermal energy. A Maxwellian distribution is found to be inadequate in describing the PTT energy spectra, but velocity-exponential and kappa distributions are both successful, the latter especially at higher energies. The power-law index kappa varies from PTT to PTT, but the high-energy spectral index and overall shape of the distribution remain constant during a PTT; both spatial and temporal effects are observed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/5801137','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/5801137"><span><span class="hlt">Plasma</span> <span class="hlt">sheet</span> motions inferred from medium-energy ion measurements</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Andrews, M.K.; Keppler, E.; Daly, P.W.</p> <p>1981-09-01</p> <p>Medium-energy ions (E>25 keV) measured by the ISEE 2 satellite are used to provide information on <span class="hlt">plasma</span> <span class="hlt">sheet</span> motions during expansions following substorms. We show that the upward speed of the <span class="hlt">plasma</span> <span class="hlt">sheet</span> edge measured locally is commonly approx.50 km/s, a value high in comparison with two-satellite measurements. It is thought that waves in the form of field-aligned corrugations of the <span class="hlt">sheet</span> boundary may be responsible for the high speeds measured in some cases. The boundary between the lobe and <span class="hlt">plasma</span> <span class="hlt">sheet</span> intensity fluxes is about 2 R/sub g/ thick at the ion energies looked at, or 1000--3000 km. After the passage of the <span class="hlt">plasma</span> <span class="hlt">sheet</span> boundary, particle fluxes drifting downward toward the neutral <span class="hlt">sheet</span> are often encountered. This is interpreted as an E x B drift, in which case the electric field is about 1 mV//m. This could imply high cross-tail potentials. At the outer boundary of the <span class="hlt">plasma</span> <span class="hlt">sheet</span>, it is found that the streaming ion layer recently reported by Moebius et al. (1980) and Spjeldvik and Fritz (unpublished manuscript, 1980) shows a peaked spectrum that softens as the <span class="hlt">plasma</span> <span class="hlt">sheet</span> is approached. The observation of a rising <span class="hlt">plasma</span> <span class="hlt">sheet</span> boundary, downward-drifting flux tubes, and the behavior of the streaming ion layer are consistent with the tailward motion of a source region together with a cross-tail electric field. The data can be interpreted to show that the source region when the <span class="hlt">plasma</span> <span class="hlt">sheet</span> 20 R/sub E/ downtail has expanded to about 6 R/sub E/ is approx.50 R/sub E/ down the tail.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19850041180&hterms=knott&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAuthor-Name%26N%3D0%26No%3D40%26Ntt%3Dknott','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19850041180&hterms=knott&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAuthor-Name%26N%3D0%26No%3D40%26Ntt%3Dknott"><span>Electric fields in the <span class="hlt">plasma</span> <span class="hlt">sheet</span> and <span class="hlt">plasma</span> <span class="hlt">sheet</span> boundary layer</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Pedersen, A.; Knott, K.; Cattell, C. A.; Mozer, F. S.; Falthammar, C.-G.; Lindqvist, P.-A.; Manka, R. H.</p> <p>1985-01-01</p> <p>Results obtained by Forbes et al. (1981) on the basis of time delay measurements between ISEE 1 and ISEE 2 imply that the <span class="hlt">plasma</span> flow and the boundary contracting velocity were nearly the same, whereas the expanding boundary velocity was not accompanied by any significant <span class="hlt">plasma</span> <span class="hlt">sheet</span> <span class="hlt">plasma</span> motion. In the present study, this observation is discussed in conjunction with electric field data. The study is based on electric field data from the spherical double probe experiment on ISEE 1. Electric field data from GEOS 2 are used to some extent to monitor the electric fields near the geostationary orbit during the considered eve nts. Electric field data during CDAW 6 events are discussed, taking into account positions of ISEE 1/ISEE 2 and GEOS 2; March 22, 0600-1300 UT; and March 22, UT; and March 31, 1400-2400 UT.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2007AGUFMSM12B..01C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2007AGUFMSM12B..01C"><span><span class="hlt">Plasma</span> <span class="hlt">Sheet</span> Response to the Ionosphere's Demand for Field-Aligned Current</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Coroniti, F. V.; Pritchett, P. L.</p> <p>2007-12-01</p> <p>Magnetospheric convection electric fields and <span class="hlt">plasma</span> stresses are transmitted to the ionosphere by Alfvén wave electric fields and field-aligned currents (FACs). The closure of the FACs by ionospheric Hall and Pedersen currents drives the ionospheric convection system. However, the ionospheric system does not necessarily mesh smoothly with the magnetospheric drivers, and the magnetosphere must respond by altering its convection and <span class="hlt">plasma</span> stress configuration, thereby creating self-consistent closure paths for the complete coupled system of currents and electric potentials. Three-dimensional particle-in-cell <span class="hlt">plasma</span> kinetic simulations are used to determine the <span class="hlt">plasma</span> <span class="hlt">sheet</span> response to various current systems imposed as boundary conditions at the near-Earth boundary. These systems consist of separate downward and upward tubes of FAC and a substorm current wedge configuration. The results demonstrate that the creation of closure paths for ionospheric FACs can result in large configuration changes within the near-Earth <span class="hlt">plasma</span> <span class="hlt">sheet</span>. The <span class="hlt">plasma</span> <span class="hlt">sheet</span> is forced to establish polarization electric fields that locally increase the cross-tail current by producing a duskward Hall <span class="hlt">electron</span> current; this results in the formation of thin (in z), spatially localized (in y) <span class="hlt">electron</span>-dominated Hall current <span class="hlt">sheets</span>. The observed complex magnetic field configuration with opposite polarity Bz fields in close proximity separated by <span class="hlt">electron</span> scale thin current <span class="hlt">sheets</span> is reminiscent of the turbulent magnetic fields that are observed within the near-Earth current disruption region at substorm breakup [ Lui et al., 1988, 1992].</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19720058742&hterms=balance+sheet+energy&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3Dbalance%2Bsheet%2Benergy','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19720058742&hterms=balance+sheet+energy&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3Dbalance%2Bsheet%2Benergy"><span>On the balance of stresses in the <span class="hlt">plasma</span> <span class="hlt">sheet</span>.</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Rich, F. J.; Wolf, R. A.; Vasyliunas, V. M.</p> <p>1972-01-01</p> <p>The stress resulting from magnetic tension on the neutral <span class="hlt">sheet</span> must, in a steady state, be balanced by any one or a combination of (1) a pressure gradient in the direction along the axis of the tail, (2) a similar gradient of <span class="hlt">plasma</span> flow kinetic energy, and (3) the tension resulting from a pressure anisotropy within the <span class="hlt">plasma</span> <span class="hlt">sheet</span>. Stress balance in the first two cases requires that the ratios h/LX and BZ/BX be of the same order of magnitude, where h is the half-thickness of the neutral <span class="hlt">sheet</span>, LX is the length scale for variations along the axis of the tail, and BZ and BX are the magnetic field components in the <span class="hlt">plasma</span> <span class="hlt">sheet</span> just outside the neutral <span class="hlt">sheet</span>. The second case requires, in addition, that the <span class="hlt">plasma</span> flow speed within the neutral <span class="hlt">sheet</span> be of the order of or larger than the Alfven speed outside the neutral <span class="hlt">sheet</span>. Stress balance in the third case requires that just outside the neutral <span class="hlt">sheet</span> the <span class="hlt">plasma</span> pressure obey the marginal firehose stability condition.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_1");'>1</a></li> <li><a href="#" onclick='return showDiv("page_2");'>2</a></li> <li class="active"><span>3</span></li> <li><a href="#" onclick='return showDiv("page_4");'>4</a></li> <li><a href="#" onclick='return showDiv("page_5");'>5</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_3 --> <div id="page_4" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_2");'>2</a></li> <li><a href="#" onclick='return showDiv("page_3");'>3</a></li> <li class="active"><span>4</span></li> <li><a href="#" onclick='return showDiv("page_5");'>5</a></li> <li><a href="#" onclick='return showDiv("page_6");'>6</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="61"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013APS..DPPBO5014G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013APS..DPPBO5014G"><span>Microwave measurements on a well-collimated dusty <span class="hlt">plasma</span> <span class="hlt">sheet</span> for communications blackout applications</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Gillman, Eric; Amatucci, Bill</p> <p>2013-10-01</p> <p>A linear hollow cathode produces an <span class="hlt">electron</span> beam that is accelerated into a low pressure (50 to 150 mTorr) background of Argon, producing an <span class="hlt">electron</span> beam discharge. A relatively constant 170 Gauss axial magnetic field is produced by two electromagnet coils arranged in a Helmholtz configuration. This results in a well-collimated <span class="hlt">electron</span> beam, producing a 2-dimensional discharge <span class="hlt">sheet</span> (40 cm high by 30 cm wide by 1 cm thick) with densities as high as 1012 cm-3. The <span class="hlt">plasma</span> <span class="hlt">sheet</span> is intended to replicate the parameters of the <span class="hlt">plasma</span> layer produced around hypersonic and reentry vehicles. The <span class="hlt">electron</span> beam is accelerated vertically towards a grounded beam dump electrode. This electrode is modified to include an array of six piezo buzzers modified and filled with alumina powder. When powered with a modest voltage, the piezoelectric shakers drop dust particles into the <span class="hlt">plasma</span> <span class="hlt">sheet</span> discharge directly below. A transmitting microwave horn is oriented normal to the dense <span class="hlt">plasma</span> <span class="hlt">sheet</span> while the receiving horn is mounted on a stage that can be rotated up to 180 degrees azimuthally. Microwave transmission and scattering measurements of the <span class="hlt">plasma</span> <span class="hlt">sheet</span> are made in the S-band and X-band for applications related to communications blackout. This research was performed while the primary author held a National Research Council Research Associateship Award at the Naval Research Laboratory.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AdSpR..59..274W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AdSpR..59..274W"><span>Gyrophase bunched ions in the <span class="hlt">plasma</span> <span class="hlt">sheet</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Wang, Zhiqiang; Zhai, Hao; Gao, Zhuxiu; Huang, Chaoyan</p> <p>2017-01-01</p> <p>Gyrophase bunched ions were first detected in the upstream region of the Earth's bow shock in the early 1980s which is formed by the microphysical process associated with reflected solar wind ions at the bow shock. Inside the magnetosphere, the results of computer simulations demonstrated that nonlinear wave-particle interaction can also result in the gyrophase bunching of particles. However, to date direct observations barely exist regarding this issue occurred inside the magnetosphere. In this paper, we report for the first time an event of gyrophase bunched ions observed in the near-Earth <span class="hlt">plasma</span> <span class="hlt">sheet</span>. The nongyrotropic distributions of ions were closely accompanied with the electromagnetic waves at the oxygen cyclotron frequency. The phase of bunched ions and the phase of waves mainly have very narrow phase differences (<30°) when the O+ band waves are remarkably enhanced, which indicates that the wave and particle are closely corotating. The "electric phase bunching" is considered to be a possible mechanism for the formation of the gyrophase bunched distributions in this case. The MVA analysis suggests that the oxygen band waves possess left helicity with respect to the propagation direction, which agrees with the characteristic of electromagnetic ion cyclotron waves. The observation of O+ ions composition suggests that the oxygen band waves are excited due to the enhancements of the O+ ion density. This study suggests that the gyrophase bunching is a significant nonlinear effect that exists not only in the bow shock but also in the inner magnetosphere.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015JGRA..120.5009L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015JGRA..120.5009L"><span>Azimuthal flow bursts in the inner <span class="hlt">plasma</span> <span class="hlt">sheet</span> and possible connection with SAPS and <span class="hlt">plasma</span> <span class="hlt">sheet</span> earthward flow bursts</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Lyons, L. R.; Nishimura, Y.; Gallardo-Lacourt, B.; Nicolls, M. J.; Chen, S.; Hampton, D. L.; Bristow, W. A.; Ruohoniemi, J. M.; Nishitani, N.; Donovan, E. F.; Angelopoulos, V.</p> <p>2015-06-01</p> <p>We have combined radar observations and auroral images obtained during the Poker Flat Incoherent Scatter Radar Ion Neutral Observations in the Thermosphere campaign to show the common occurrence of westward moving, localized auroral brightenings near the auroral equatorward boundary and to show their association with azimuthally moving flow bursts near or within the subauroral polarization stream (SAPS) region. These results indicate that the SAPS region, rather than consisting of relatively stable proton precipitation and westward flows, can have rapidly varying flows, with speeds varying from ~100 m/s to ~1 km/s in just a few minutes. The auroral brightenings are associated with bursts of weak <span class="hlt">electron</span> precipitation that move westward with the westward flow bursts and extend into the SAPS region. Additionally, our observations show evidence that the azimuthally moving flow bursts often connect to earthward (equatorward in the ionosphere) <span class="hlt">plasma</span> <span class="hlt">sheet</span> flow bursts. This indicates that rather than stopping or bouncing, some flow bursts turn azimuthally after reaching the inner <span class="hlt">plasma</span> <span class="hlt">sheet</span> and lead to the bursts of strong azimuthal flow. Evidence is also seen for a general guiding of the flow bursts by the large-scale convection pattern, flow bursts within the duskside convection being azimuthally turned to the west, and those within the dawn cell being turned toward the east. The possibility that the SAPS region flow structures considered here may be connected to localized flow enhancements from the polar cap that cross the nightside auroral poleward boundary and lead to flow bursts within the <span class="hlt">plasma</span> <span class="hlt">sheet</span> warrants further consideration.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19810019186','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19810019186"><span>Multiple crossings of a very thin <span class="hlt">plasma</span> <span class="hlt">sheet</span> in the Earth's magnetotail</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Fairfield, D. H.; Hones, E. W., Jr.; Meng, C. I.</p> <p>1981-01-01</p> <p>High resolution magnetic field, <span class="hlt">plasma</span> and energetic particle data from the IMP-8 spacecraft were studied for multiple crossings of the Earth's magnetotail <span class="hlt">plasma</span> <span class="hlt">sheet</span> when it becomes thin during magnetospheric substorms. Traversals recur on a time scale of several minutes and they are associated with high velocity <span class="hlt">plasma</span> flows that are usually directed tailward but are occasionally directed earthward for brief intervals. Observations are explained by rapid oscillations of a <span class="hlt">plasma</span> <span class="hlt">sheet</span> that is only a few thousand km thick, a dimension comparable to the gyroradius of energetic protons. Differences in the angular distributions of the two energies indicate that the higher energy protons are preferentially located on field lines deeper in the tail lobe. A neutral line acceleration model is supported tailward streaming energetic <span class="hlt">electrons</span> which are occasionally present at the lobe <span class="hlt">plasma</span> <span class="hlt">sheet</span> interface.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/5268516','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/5268516"><span>Injection of ionospheric ions into the <span class="hlt">plasma</span> <span class="hlt">sheet</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Orsini, S.; Candidi, M. ); Stokholm, M.; Balsiger, H. )</p> <p>1990-06-01</p> <p>The ISEE 1 and ISEE 2 observations of the lobe/mantle and of the <span class="hlt">plasma</span> <span class="hlt">sheet</span> region, at distances between 10 and 20 RE downtail during 1978 and 1979, have been examined. Cold, tailward flowing ionospheric O{sup +} streams (at energies between 50 eV/q and 5 keV/q), observed during geomagnetically disturbed periods, have been statistically analyzed. At the crossing between the lobe/mantle region and the <span class="hlt">plasma</span> <span class="hlt">sheet</span> the characteristics of the streams change significantly. These changes suggest the action of energization and isotropization processes which accelerate the ionospheric ions and make them a part of the <span class="hlt">plasma</span> <span class="hlt">sheet</span> <span class="hlt">plasma</span>. The region where these processes are observed is assumed here to be the <span class="hlt">plasma</span> <span class="hlt">sheet</span> boundary layer. It is shown that the stream flow pattern in the lobe/mantle region is in good agreement with the tail lobe ion spectrometer model for the thermal speed distribution as well as for the flow velocity and density distributions. This agreement also holds in a qualitative sense in the <span class="hlt">plasma</span> <span class="hlt">sheet</span> boundary layer, assuming the appropriate electric field configuration; the E {times} B drift direction along the YGSE axis appears to reverse with respect to what is observed in the lobe/mantle region, in agreement with the assumed reversal of the Z component of the dc electric field at the <span class="hlt">plasma</span> <span class="hlt">sheet</span> boundary.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2004AnGeo..22.4165D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2004AnGeo..22.4165D"><span>Thinning and expansion of the substorm <span class="hlt">plasma</span> <span class="hlt">sheet</span>: Cluster PEACE timing analysis</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Dewhurst, J.; Owen, C.; Fazakerley, A.; Balogh, A.</p> <p>2004-12-01</p> <p>The storage and subsequent removal of magnetic flux in the magnetotail during a geomagnetic substorm has a dramatic effect on the thickness of the cross-tail <span class="hlt">plasma</span> <span class="hlt">sheet</span>. The near-Earth <span class="hlt">plasma</span> <span class="hlt">sheet</span> is thought to thin during the growth phase and then rapidly expand after onset of the substorm. The direction of propagation, whether earthward or tailward along the GSM-X direction in the near-Earth tail, may suggest the time ordering of current-disruption and near-Earth reconnection, both of which are key to the substorm process. Cluster's <span class="hlt">Plasma</span> <span class="hlt">Electron</span> And Current Experiment (PEACE) allows 4-point observations of <span class="hlt">electrons</span> at the <span class="hlt">plasma</span> <span class="hlt">sheet</span> - lobe boundary as this interface passes over the Cluster tetrahedron. The relative timings of the boundary passage at each spacecraft allow a determination of this boundary's speed and direction of motion, assuming this is planar on the scale of the Cluster separation scale. For those boundaries corresponding to the expansion of the <span class="hlt">plasma</span> <span class="hlt">sheet</span>, this direction is fundamental to determining the direction of expansion. We present an example of isolated thinning and expansion of the <span class="hlt">plasma</span> <span class="hlt">sheet</span>, as well as a multiple thinning-expansion event that occurs during a more active substorm. Data from the 2001 and 2002 tail passes have been analysed and the average <span class="hlt">plasma</span> <span class="hlt">sheet</span> - lobe boundary normal vectors and normal component velocities have been calculated. A total of 77 crossings, typically between 10 and 20 RE downtail, correspond to substorm associated expansion of the <span class="hlt">plasma</span> <span class="hlt">sheet</span> over the spacecraft. These had normal vectors predominantly in the GSM-YZ plane and provided no clear evidence for the formation of the near-Earth neutral line occurring before current disruption or vice versa. The expansions of the <span class="hlt">plasma</span> <span class="hlt">sheet</span> generally exhibit the appropriate GSM-Z direction expected for the given lobe, and tend to have GSM-Y components that support onset occurring near the origin of the GSM-YZ plane. This result is noteworthy in</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19920041911&hterms=central+heating&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3Dcentral%2Bheating','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19920041911&hterms=central+heating&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3Dcentral%2Bheating"><span>Nonadiabatic heating of the central <span class="hlt">plasma</span> <span class="hlt">sheet</span> at substorm onset</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Huang, C. Y.; Frank, L. A.; Rostoker, G.; Fennell, J.; Mitchell, D. G.</p> <p>1992-01-01</p> <p>Heating events in the <span class="hlt">plasma</span> <span class="hlt">sheet</span> boundary layer and central <span class="hlt">plasma</span> <span class="hlt">sheet</span> are found to occur at the onset of expansive phase activity. The main effect is a dramatic increase in <span class="hlt">plasma</span> temperature, coincident with a partial dipolarization of the magnetic field. Fluxes of energetic particles increase without dispersion during these events which occur at all radial distances up to 23 RE, the apogee of the ISEE spacecraft. A major difference between these heating events and those observed at geosynchronous distances lies in the heating mechanism which is nonadiabatic beyond 10 RE but may be adiabatic closer to earth. The energy required to account for the increase in <span class="hlt">plasma</span> thermal energy is comparable with that required for Joule heating of the ionosphere. The <span class="hlt">plasma</span> <span class="hlt">sheet</span> must be considered as a major sink in the energy balance of a substorm. Lobe magnetic pressures during these events are estimated. Change in lobe pressure are generally not correlated with onsets or intensifications of expansive phase activity.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2001JGR...106.6161W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2001JGR...106.6161W"><span>Modeling the quiet time inner <span class="hlt">plasma</span> <span class="hlt">sheet</span> protons</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Wang, Chih-Ping; Lyons, Larry R.; Chen, Margaret W.; Wolf, Richard A.</p> <p>2001-04-01</p> <p>In order to understand the characteristics of the quiet time inner <span class="hlt">plasma</span> <span class="hlt">sheet</span> protons, we use a modified version of the Magnetospheric Specification Model to simulate the bounce averaged electric and magnetic drift of isotropic <span class="hlt">plasma</span> <span class="hlt">sheet</span> protons in an approximately self-consistent magnetic field. Proton differential fluxes are assigned to the model boundary to mimic a mixed tail source consisting of hot <span class="hlt">plasma</span> from the distant tail and cooler <span class="hlt">plasma</span> from the low latitude boundary layer (LLBL). The source is local time dependent and is based on Geotail observations and the results of the finite tail width convection model. For the purpose of self-consistently simulating <span class="hlt">plasma</span> motion and a magnetic field, the Tsyganenko 96 magnetic field model is incorporated with additional adjustable ring-current shaped current loops. We obtain equatorial proton flow and midnight and equatorial profiles of proton pressure, number density, and temperature. We find that our results agree well with observations. This indicates that the drift motion dominates the <span class="hlt">plasma</span> transport in the quiet time inner <span class="hlt">plasma</span> <span class="hlt">sheet</span>. Our simulations show that cold <span class="hlt">plasma</span> from the LLBL enhances the number density and the proton pressure in the inner <span class="hlt">plasma</span> <span class="hlt">sheet</span> and decreases the dawn-dusk asymmetry of the equatorial proton pressure. From our approximately force-balanced simulations the magnetic field responds to the increase of pressure gradient force in the inner <span class="hlt">plasma</span> <span class="hlt">sheet</span> by changing its configuration to give a stronger magnetic force. At the same time, the <span class="hlt">plasma</span> dynamics is affected by the changing field configuration and its associated pressure gradient force becomes smaller. Our model predicts a quiet time magnetic field configuration with a local depression in the equatorial magnetic field strength at the inner edge of the <span class="hlt">plasma</span> <span class="hlt">sheet</span> and a cross-tail current separated from the ring current, results that are supported by observations. A scale analysis of our results shows that in the</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19900029440&hterms=IRM&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D60%26Ntt%3DIRM','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19900029440&hterms=IRM&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D60%26Ntt%3DIRM"><span>Average electric wave spectra across the <span class="hlt">plasma</span> <span class="hlt">sheet</span> and their relation to ion bulk speed</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Baumjohann, W.; Treumann, R. A.; Labelle, J.; Anderson, R. R.</p> <p>1989-01-01</p> <p>Using 4 months of tail data obtained by the ELF/MF spectrum analyzer of the wave experiment and the three-dimensional <span class="hlt">plasma</span> instrument on board the AMPTE/IRM satellite, a statistical survey on the electric wave spectral density in the earth's <span class="hlt">plasma</span> <span class="hlt">sheet</span> has been conducted. More than 50,000 10-s-averaged electric wave spectra were analyzed with respect to differences between their values in the inner and outer central <span class="hlt">plasma</span> <span class="hlt">sheet</span> and the <span class="hlt">plasma</span> <span class="hlt">sheet</span> boundary layer as well as their dependence on radial distance and ion bulk speed. High-speed flows are dominated by broadband electrostatic noise with highest spectral densities in the <span class="hlt">plasma</span> <span class="hlt">sheet</span> boundary, where broadband electrostatic noise also exists during periods of low-speed flows. The broadband electrostatic noise has a typical spectral index of about -2. During low-speed flows the spectra in the central <span class="hlt">plasma</span> <span class="hlt">sheet</span> show distinct emissions at the <span class="hlt">electron</span> cyclotron odd half-harmonic and upper hybrid frequency. Wave intensities during episodes of fast perpendicular flows are higher than those associated with fast parallel flows.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016PhPl...23i2901A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016PhPl...23i2901A"><span>Effects of <span class="hlt">electron</span> pressure anisotropy on current <span class="hlt">sheet</span> configuration</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Artemyev, A. V.; Vasko, I. Y.; Angelopoulos, V.; Runov, A.</p> <p>2016-09-01</p> <p>Recent spacecraft observations in the Earth's magnetosphere have demonstrated that the magnetotail current <span class="hlt">sheet</span> can be supported by currents of anisotropic <span class="hlt">electron</span> population. Strong <span class="hlt">electron</span> currents are responsible for the formation of very thin (intense) current <span class="hlt">sheets</span> playing the crucial role in stability of the Earth's magnetotail. We explore the properties of such thin current <span class="hlt">sheets</span> with hot isotropic ions and cold anisotropic <span class="hlt">electrons</span>. Decoupling of the motions of ions and <span class="hlt">electrons</span> results in the generation of a polarization electric field. The distribution of the corresponding scalar potential is derived from the <span class="hlt">electron</span> pressure balance and the quasi-neutrality condition. We find that <span class="hlt">electron</span> pressure anisotropy is partially balanced by a field-aligned component of this polarization electric field. We propose a 2D model that describes a thin current <span class="hlt">sheet</span> supported by currents of anisotropic <span class="hlt">electrons</span> embedded in an ion-dominated current <span class="hlt">sheet</span>. Current density profiles in our model agree well with THEMIS observations in the Earth's magnetotail.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19980237410&hterms=cps&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3Dcps','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19980237410&hterms=cps&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3Dcps"><span>Central <span class="hlt">Plasma</span> <span class="hlt">Sheet</span> Ion Properties as Inferred from Ionospheric Observations</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Wing, Simon; Newell, Patrick T.</p> <p>1998-01-01</p> <p>A method of inferring central <span class="hlt">plasma</span> <span class="hlt">sheet</span> (CPS) temperature, density, and pressure from ionospheric observations is developed. The advantage of this method over in situ measurements is that the CPS can be studied in its entirely, rather than only in fragments. As a result, for the first time, comprehensive two-dimensional equatorial maps of CPS pressure, density, and temperature within the isotropic <span class="hlt">plasma</span> <span class="hlt">sheet</span> are produced. These particle properties are calculated from data taken by the Special Sensor for Precipitating Particles, version 4 (SSJ4) particle instruments onboard DMSP F8, F9, F10, and F11 satellites during the entire year of 1992. Ion spectra occurring in conjunction with <span class="hlt">electron</span> acceleration events are specifically excluded. Because of the variability of magnetotail stretching, the mapping to the <span class="hlt">plasma</span> <span class="hlt">sheet</span> is done using a modified Tsyganenko [1989] magnetic field model (T89) adjusted to agree with the actual magnetotail stretch at observation time. The latter is inferred with a high degree of accuracy (correlation coefficient -0.9) from the latitude of the DMSP b2i boundary (equivalent to the ion isotropy boundary). The results show that temperature, pressure, and density all exhibit dawn-dusk asymmetries unresolved with previous measurements. The ion temperature peaks near the midnight meridian. This peak, which has been associated with bursty bulk flow events, widens in the Y direction with increased activity. The temperature is higher at dusk than at dawn, and this asymmetry increases with decreasing distance from the Earth. In contrast, the density is higher at dawn than at dusk, and there appears to be a density enhancement in the low-latitude boundary layer regions which increases with decreasing magnetic activity. In the near-Earth regions, the pressure is higher at dusk than at dawn, but this asymmetry weakens with increasing distance from the Earth and may even reverse so that at distances X less than approx. 10 to -12 R(sub E</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015AGUFMSM42A..03M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015AGUFMSM42A..03M"><span>Features of the Active Evening <span class="hlt">Plasma</span> <span class="hlt">Sheet</span> from MMS</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Moore, T. E.; Chandler, M. O.; Avanov, L. A.; Burch, J. L.; Coffey, V. N.; Ergun, R. E.; Fuselier, S. A.; Gershman, D. J.; Giles, B. L.; Lavraud, B.; MacDonald, E.; Mauk, B.; Mukai, T.; Nakamura, R.; Pollock, C. J.; Russell, C. T.; Saito, Y.; Sauvaud, J. A.; Torbert, R. B.; Yokota, S.</p> <p>2015-12-01</p> <p>The Magnetospheric Multiscale (MMS) mission, consisting of four identical <span class="hlt">plasmas</span> and fields observatories, was launched into a 12 RE elliptical equatorial orbit in March 2015 and was in the process of being commissioned through August 2015. During commissioning, the orbit apogee rotated from near midnight through the evening toward the dusk sector and occasionally captured new observations of the <span class="hlt">plasma</span> <span class="hlt">sheet</span>, its boundary layers, and the magnetospheric tail lobes. On 22-23 June, an especially active <span class="hlt">plasma</span> <span class="hlt">sheet</span> was involved in a major geospace storm that developed a ring current with 200 nT DST. We report on the ion kinetic and flow features of this active <span class="hlt">plasma</span> <span class="hlt">sheet</span>, comparing them with familiar observations from earlier missions, as an exercise in validating the MMS observations and assessing their capabilities to provide higher time resolution in multi-point views of thin, fast-moving structures. The observed features include but are not limited to cold lobal wind streams in the lobes, tailward flowing auroral beams and conics, hot earthward field-aligned flows and counter-flows, fast cross-field convection of some flows toward the neutral <span class="hlt">sheet</span>, and the hot isotropic <span class="hlt">plasma</span> <span class="hlt">sheet</span> proper. Relationships between these features, the ionosphere, and the reconnecting magnetotail will be explored and discussed, seeking preliminary conclusions.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016JGRA..121.9608E','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016JGRA..121.9608E"><span>Strong current <span class="hlt">sheet</span> at a magnetosheath jet: Kinetic structure and <span class="hlt">electron</span> acceleration</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Eriksson, E.; Vaivads, A.; Graham, D. B.; Khotyaintsev, Yu. V.; Yordanova, E.; Hietala, H.; André, M.; Avanov, L. A.; Dorelli, J. C.; Gershman, D. J.; Giles, B. L.; Lavraud, B.; Paterson, W. R.; Pollock, C. J.; Saito, Y.; Magnes, W.; Russell, C.; Torbert, R.; Ergun, R.; Lindqvist, P.-A.; Burch, J.</p> <p>2016-10-01</p> <p>Localized kinetic-scale regions of strong current are believed to play an important role in <span class="hlt">plasma</span> thermalization and particle acceleration in turbulent <span class="hlt">plasmas</span>. We present a detailed study of a strong localized current, 4900 nA m-2, located at a fast <span class="hlt">plasma</span> jet observed in the magnetosheath downstream of a quasi-parallel shock. The thickness of the current region is ˜3 ion inertial lengths and forms at a boundary separating magnetosheath-like and solar wind-like <span class="hlt">plasmas</span>. On ion scales the current region has the shape of a <span class="hlt">sheet</span> with a significant average normal magnetic field component but shows strong variations on smaller scales. The dynamic pressure within the magnetosheath jet is over 3 times the solar wind dynamic pressure. We suggest that the current <span class="hlt">sheet</span> is forming due to high velocity shears associated with the jet. Inside the current <span class="hlt">sheet</span> we observe local <span class="hlt">electron</span> acceleration, producing <span class="hlt">electron</span> beams, along the magnetic field. However, there is no clear sign of ongoing reconnection. At higher energies, above the beam energy, we observe a loss cone consistent with part of the hot magnetosheath-like <span class="hlt">electrons</span> escaping into the colder solar wind-like <span class="hlt">plasma</span>. This suggests that the acceleration process within the current <span class="hlt">sheet</span> is similar to the one that occurs at shocks, where <span class="hlt">electron</span> beams and loss cones are also observed. Therefore, <span class="hlt">electron</span> beams observed in the magnetosheath do not have to originate from the bow shock but can also be generated locally inside the magnetosheath.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19950046223&hterms=function+kidneys&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3Dfunction%2Bkidneys','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19950046223&hterms=function+kidneys&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3Dfunction%2Bkidneys"><span>Nature and location of the source of <span class="hlt">plasma</span> <span class="hlt">sheet</span> boundary layer ion beams</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Elphic, R. C.; Onsager, T. G.; Thomsen, M. F.; Gosling, J. T.</p> <p>1995-01-01</p> <p>Onsager et al. (1991) have put forward a model of the formation of the <span class="hlt">plasma</span> <span class="hlt">sheet</span> boundary layer (PSBL) which relies on a steady source of <span class="hlt">plasma</span> from a spatially extended <span class="hlt">plasma</span> <span class="hlt">sheet</span>, together with steady equatorward and earthward ExB convection of field lines due to reconnection at a downtail neutral line. This model is a synthesis of earlier proposals and it explains such features as an <span class="hlt">electron</span> layer exterior to the ion boundary layer, ion velocity dispersion, counter streaming beams, low-speed cutoffs in the beams. It also explains the apparent evolution of the ion beams through 'kidney bean' shaped velocity-space distributions toward quasi-isotropic shells without invoking pitch angle scattering or energy diffusion. In this paper we explore two ramifications of the model. In principle we can map, as a function of time, the downtail neutral line distance and establish whether or not it is retreating during substorm recovery. We can also reconstruct the <span class="hlt">plasma</span> distribution function near the neutral line to see if it is most consistent with mantle or <span class="hlt">plasma</span> <span class="hlt">sheet</span> <span class="hlt">plasma</span>. We perform this analysis using International Sun Earth Explorer (ISEE) Fast <span class="hlt">Plasma</span> Experiment (FPE) data for two <span class="hlt">plasma</span> <span class="hlt">sheet</span> recovery events, one on March 1, 1978, and the other on April 18, 1978. On March 1, 1978, we find evidence for an initial retreat from around 110 to 160 R(sub E) in the first 15 min; little further retreat occurs thereafter. On April 18, 1978, the neutral line location ranges from as little as 40 R(sub E) tailward of the satellite to as much as 200 R(sub E), but there is no evidence for a systematic retreat. The reconstructed ion distributions for these events are most consistent with a <span class="hlt">plasma</span> <span class="hlt">sheet</span> origin for the March 1 case and possibly <span class="hlt">plasma</span> mantle or low-latitude boundary layer for the April 18 case.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2005AGUSMSH41A..01Z','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2005AGUSMSH41A..01Z"><span>Thickness of Heliospheric Current and <span class="hlt">Plasma</span> <span class="hlt">Sheets</span>: Dependence on Distance</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Zhou, X.; Smith, E. J.; Winterhalter, D.; McComas, D. J.; Skoug, R. M.; Goldstein, B. E.; Smith, C. W.</p> <p>2005-05-01</p> <p>Heliospheric current <span class="hlt">sheets</span> (HCS) are well defined structures that separate the interplanetary magnetic fields with inverse polarities. Surrounded by heliospheric <span class="hlt">plasma</span> <span class="hlt">sheets</span> (HPS), the current <span class="hlt">sheets</span> stretch throughout the heliosphere. Interesting questions that still remain unanswered include how the thickness of these structures will change along the distance? And what determines the thickness of these structures? To answer these fundamental questions, we have carried out a study of the HCS and HPS using recent Ulysses data near 5 AU. When the results were compared with earlier studies at 1 AU using ISEE-3 data, they were surprising and unexplained. Although the <span class="hlt">plasma</span> <span class="hlt">sheet</span> grew thicker, the embedded current <span class="hlt">sheet</span> grew thinner! Using data under the same (or very similar) circumstances, we have extended the analysis in two ways. First, the same current-<span class="hlt">plasma</span> <span class="hlt">sheets</span> studied at 5 AU have been identified at 1 AU using ACE data. Second, data obtained while Ulysses was en-route to Jupiter near 3 AU have been analyzed. This three-point investigation reveals the thickness variation along the distance and enables the examination of the controller of this variation.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=20080007493&hterms=slow+down&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3Dslow%2Bdown','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20080007493&hterms=slow+down&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3Dslow%2Bdown"><span>Slow Mode Waves in the Heliospheric <span class="hlt">Plasma</span> <span class="hlt">Sheet</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Smith, Edward. J.; Zhou, Xiaoyan</p> <p>2007-01-01</p> <p>We report the results of a search for waves/turbulence in the Heliospheric <span class="hlt">Plasma</span> <span class="hlt">Sheet</span> (HPS) surrounding the Heliospheric Current <span class="hlt">Sheet</span> (HCS). The HPS is treated as a distinctive heliospheric structure distinguished by relatively high Beta, slow speed <span class="hlt">plasma</span>. The data used in the investigation are from a previously published study of the thicknesses of the HPS and HCS that were obtained in January to May 2004 when Ulysses was near aphelion at 5 AU. The advantage of using these data is that the HPS is thicker at large radial distances and the spacecraft spends longer intervals inside the <span class="hlt">plasma</span> <span class="hlt">sheet</span>. From the study of the magnetic field and solar wind velocity components, we conclude that, if Alfven waves are present, they are weak and are dominated by variations in the field magnitude, B, and solar wind density, NP, that are anti-correlated.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015JGRA..120.2600S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015JGRA..120.2600S"><span>Properties and origin of subproton-scale magnetic holes in the terrestrial <span class="hlt">plasma</span> <span class="hlt">sheet</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Sundberg, T.; Burgess, D.; Haynes, C. T.</p> <p>2015-04-01</p> <p><span class="hlt">Electron</span>-scale magnetic depressions in the terrestrial <span class="hlt">plasma</span> <span class="hlt">sheet</span> are studied using Cluster multispacecraft data. The structures, which have an observed duration of ~5-10 s, are approximately 200-300 km wide in the direction of propagation, and they show an average reduction in the background magnetic field of 10-20%. A majority of the events are also associated with an increase in the high-energy high pitch angle <span class="hlt">electron</span> flux, which indicates that the depressions are presumably generated by <span class="hlt">electrons</span> with relatively high velocity perpendicular to the background magnetic field. Differences in the recorded <span class="hlt">electron</span> spectra in the four spacecraft indicates a possible nongyrotropic structure. Multispacecraft measurements show that a subset of events are cylindrical, elongated along the magnetic field, and with a field-parallel scale size of at a minimum 500 km. Other events seem to be better described as <span class="hlt">electron</span>-scale <span class="hlt">sheets</span>, about 200-300 km thick. We find that no single formation mechanism can explain this variety of events observed. Instead, several processes may be operating in the <span class="hlt">plasma</span> <span class="hlt">sheet</span>, giving rise to similar magnetic field structures in the single-spacecraft data, but with different 3-D structuring. The cylindrical structures have several traits that are in agreement with the <span class="hlt">electron</span> vortex magnetic holes observed in 2-D particle-in-cell simulations of turbulent relaxation, whereas the <span class="hlt">sheets</span>, which show nearly identical signatures in the multispacecraft data, are better explained by propagating <span class="hlt">electron</span> solitary waves.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014AGUFMSH43A4166W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014AGUFMSH43A4166W"><span>An Unusual Heliospheric <span class="hlt">Plasma</span> <span class="hlt">Sheet</span> Crossing at 1 AU</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Wu, C. C.; Liou, K.; Vourlidas, A.; Lepping, R. P.; Wang, Y. M.; Plunkett, S. P.; Socker, D. G.; Wu, S. T.</p> <p>2014-12-01</p> <p>At 11:46UT on September 9, 2011, the Wind spacecraft encountered an interplanetary (IP) fast forward shock. The shock was followed almost immediately (~5 minutes) by a short duration (~35 minutes), extremely large density pulse with a density peak of ~100 cm-3. While a sharp increase in the solar wind density is typical of an IP shock downstream, the unusual large density increase prompts a further investigation. After a close examination of other in situ data from Wind, we find the density pulse was associated with (1) a spike in the <span class="hlt">plasma</span> beta (ratio of thermal to magnetic pressure), (2) multiple sign changes in the azimuthal angle of magnetic field, (3) depressed magnetic field, (4) a small radial component of magnetic field, and (5) a large (>90 degrees) pitch-angle change in suprathermal <span class="hlt">electrons</span> (>200 eV) across the density pulse. We conclude that the density pulse is the heliospheric <span class="hlt">plasma</span> <span class="hlt">sheet</span> and the estimated thickness is ~820,000km. The unusually large density pulse is likely to be a result of the shock compression from behind. This view is supported by our 3D magnetohydrodynamic simulation. The detailed result and implications will be discussed. *This work is supported partially by ONR 6.1 program</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/6814331','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/6814331"><span>Energetic particles in the vicinity of a possible neutral line in the <span class="hlt">plasma</span> <span class="hlt">sheet</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Moebius, E.; Scholer, M.; Hovestadt, D.; Paschmann, G.; Gloeckler, G.</p> <p>1983-10-01</p> <p>We have analyzed energetic protons in the energy range 30 to 500 keV and energetic <span class="hlt">electrons</span> > or =75 keV obtained with the Max-Planck-Institut/University of Maryland sensor system on ISEE-1 during a <span class="hlt">plasma</span> <span class="hlt">sheet</span> crossing on March 26, 1978. The behavior of protons with energies of more than approx.100 keV is very different from that of the approx.30 to approx.100 keV protons which represent the suprathermal tail of the <span class="hlt">plasma</span> <span class="hlt">sheet</span> distribution. The more energetic ions appear on a time scale of serveral minutes following a northward turning of the tail magnetic field. At about the same time the plassma measurements show a velocity of approx.200 km/s in the tailward direction. This velocity enhancement is first seen at ISEE-1 and later on at ISEE-2, which is earthward of ISEE-1. The temporal sequence of the energetic particle, magnetic field, and <span class="hlt">plasma</span> observations and the proton and <span class="hlt">electron</span> anisotropies are discussed in terms of acceleration near a magnetic neutral line which occurs well within the <span class="hlt">plasma</span> <span class="hlt">sheet</span>. In this framework the magnetic neutral line would move earthward, followed by a magnetic island. The extent of the neutral line would be limited to the dusk side of the tail. No disruption of the <span class="hlt">plasma</span> <span class="hlt">sheet</span> is observed as compared to large-scale substorm activity.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1998APS..DPP.K6S06S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1998APS..DPP.K6S06S"><span>Space Charge Effect in the <span class="hlt">Sheet</span> and Solid <span class="hlt">Electron</span> Beam</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Song, Ho Young; Kim, Hyoung Suk; Ahn, Saeyoung</p> <p>1998-11-01</p> <p>We analyze the space charge effect of two different types of <span class="hlt">electron</span> beam ; <span class="hlt">sheet</span> and solid <span class="hlt">electron</span> beam. <span class="hlt">Electron</span> gun simulations are carried out using shadow and control grids for high and low perveance. Rectangular and cylindrical geometries are used for <span class="hlt">sheet</span> and solid <span class="hlt">electron</span> beam in planar and disk type cathode. The E-gun code is used to study the limiting current and space charge loading in each geometries.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_2");'>2</a></li> <li><a href="#" onclick='return showDiv("page_3");'>3</a></li> <li class="active"><span>4</span></li> <li><a href="#" onclick='return showDiv("page_5");'>5</a></li> <li><a href="#" onclick='return showDiv("page_6");'>6</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_4 --> <div id="page_5" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_3");'>3</a></li> <li><a href="#" onclick='return showDiv("page_4");'>4</a></li> <li class="active"><span>5</span></li> <li><a href="#" onclick='return showDiv("page_6");'>6</a></li> <li><a href="#" onclick='return showDiv("page_7");'>7</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="81"> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19720055071&hterms=balance+sheet+energy&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3Dbalance%2Bsheet%2Benergy','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19720055071&hterms=balance+sheet+energy&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3Dbalance%2Bsheet%2Benergy"><span><span class="hlt">Plasma</span> <span class="hlt">sheet</span> at lunar distance - Structure and solar-wind dependence.</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Nishida, A.; Lyon, E. F.</p> <p>1972-01-01</p> <p>Analysis of Explorer 35 observation of low-energy (0.1 to 3 keV) <span class="hlt">electrons</span> in the distant geomagnetic tail at 60 earth radii, and comparison with the solar-wind conditions monitored simultaneously by Explorer 33. The <span class="hlt">plasma</span> <span class="hlt">sheet</span> extends to the lunar distance with almost the same characteristics as those observed in the near tail region; the thickness is several earth radii, and the flux, density, and energy are of the order of 10 to the 9th per sq cm per sec, 1 per cu cm, and 0.6 keV, respectively. The latitudinal boundaries of the <span class="hlt">plasma</span> <span class="hlt">sheet</span> are essentially parallel to magnetic-field lines. Indication is seen of the thinning of the <span class="hlt">plasma</span> <span class="hlt">sheet</span> during polar substorms. The average energy of <span class="hlt">electrons</span> is correlated with the solar-wind velocity in agreement with the view that <span class="hlt">plasma-sheet</span> <span class="hlt">electrons</span> originate from the magnetosheath. The flux is correlated with the solar-wind dynamic pressure, reflecting the dynamic balance between the solar wind and the geomagnetic tail.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19880059306&hterms=ISEE-3&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3DISEE-3','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19880059306&hterms=ISEE-3&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3DISEE-3"><span>Magnetic configuration of the distant <span class="hlt">plasma</span> <span class="hlt">sheet</span> - ISEE 3 observations</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Slavin, J. A.; Smith, E. J.; Daly, P. W.; Sanderson, T. R.; Wenzel, K.-P.; Lepping, R. P.</p> <p>1987-01-01</p> <p>The influence of the IMF orientation and magnitude and substorm activity on the magnetic configuration of the central <span class="hlt">plasma</span> <span class="hlt">sheet</span> at 20-240 earth radii down the geomagnetic tail is investigated on the basis of ISEE-3 data. The results are presented graphically, and high-speed antisolar bulk flows threaded by southward magnetic fields are shown to be present in the distant <span class="hlt">plasma</span> <span class="hlt">sheet</span> after periods of substorm activity and southward IMF Bz. The effective dayside reconnection efficiency is estimated as 25 + or - 4 percent, in good agreement with theoretical models.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20110024199','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20110024199"><span><span class="hlt">Plasma</span> <span class="hlt">Sheet</span> Velocity Measurement Techniques for the Pulsed <span class="hlt">Plasma</span> Thruster SIMP-LEX</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Nawaz, Anuscheh; Lau, Matthew</p> <p>2011-01-01</p> <p>The velocity of the first <span class="hlt">plasma</span> <span class="hlt">sheet</span> was determined between the electrodes of a pulsed <span class="hlt">plasma</span> thruster using three measurement techniques: time of flight probe, high speed camera and magnetic field probe. Further, for time of flight probe and magnetic field probe, it was possible to determine the velocity distribution along the electrodes, as the <span class="hlt">plasma</span> <span class="hlt">sheet</span> is accelerated. The results from all three techniques are shown, and are compared for one thruster geometry.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/1336033','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/1336033"><span>Preliminary characterization of a laser-generated <span class="hlt">plasma</span> <span class="hlt">sheet</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Keiter, P. A.; Malamud, G.; Trantham, M.; Fein, J.; Davis, J.; Klein, S. R.; Drake, R. P.</p> <p>2014-12-10</p> <p>We present the results from recent experiments to create a flowing <span class="hlt">plasma</span> <span class="hlt">sheet</span>. Two groups of three laser beams with nominally 1.5 kJ of energy per group were focused to separate pointing locations, driving a shock into a wedge target. As the shock breaks out of the wedge, the <span class="hlt">plasma</span> is focused on center, creating a <span class="hlt">sheet</span> of <span class="hlt">plasma</span>. Measurements at 60 ns indicate the <span class="hlt">plasma</span> <span class="hlt">sheet</span> has propagated 2825 microns with an average velocity of 49 microns/ns. These experiments follow previous experiments, which are aimed at studying similar physics as that found in the hot spot region of cataclysmic variables. Krauland et al created a flowing <span class="hlt">plasma</span>, which represents the flowing <span class="hlt">plasma</span> from the secondary star. This flow interacted with a stationary object, which represented the disk around the white dwarf. A reverse shock is a shock formed when a freely expanding <span class="hlt">plasma</span> encounters an obstacle. Reverse shocks can be generated by a blast wave propagating through a medium. As a result, they can also be found in binary star systems where the flowing gas from a companion star interacts with the accretion disk of the primary star.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/pages/biblio/1336033-preliminary-characterization-laser-generated-plasma-sheet','SCIGOV-DOEP'); return false;" href="https://www.osti.gov/pages/biblio/1336033-preliminary-characterization-laser-generated-plasma-sheet"><span>Preliminary characterization of a laser-generated <span class="hlt">plasma</span> <span class="hlt">sheet</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/pages">DOE PAGES</a></p> <p>Keiter, P. A.; Malamud, G.; Trantham, M.; ...</p> <p>2014-12-10</p> <p>We present the results from recent experiments to create a flowing <span class="hlt">plasma</span> <span class="hlt">sheet</span>. Two groups of three laser beams with nominally 1.5 kJ of energy per group were focused to separate pointing locations, driving a shock into a wedge target. As the shock breaks out of the wedge, the <span class="hlt">plasma</span> is focused on center, creating a <span class="hlt">sheet</span> of <span class="hlt">plasma</span>. Measurements at 60 ns indicate the <span class="hlt">plasma</span> <span class="hlt">sheet</span> has propagated 2825 microns with an average velocity of 49 microns/ns. These experiments follow previous experiments, which are aimed at studying similar physics as that found in the hot spot region of cataclysmicmore » variables. Krauland et al created a flowing <span class="hlt">plasma</span>, which represents the flowing <span class="hlt">plasma</span> from the secondary star. This flow interacted with a stationary object, which represented the disk around the white dwarf. A reverse shock is a shock formed when a freely expanding <span class="hlt">plasma</span> encounters an obstacle. Reverse shocks can be generated by a blast wave propagating through a medium. As a result, they can also be found in binary star systems where the flowing gas from a companion star interacts with the accretion disk of the primary star.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.dtic.mil/docs/citations/ADA404756','DTIC-ST'); return false;" href="http://www.dtic.mil/docs/citations/ADA404756"><span>Physics and Dynamics of Current <span class="hlt">Sheets</span> in Pulsed <span class="hlt">Plasma</span> Thrusters</span></a></p> <p><a target="_blank" href="https://publicaccess.dtic.mil/psm/api/service/search/search">DTIC Science & Technology</a></p> <p></p> <p>2007-11-02</p> <p>pulsed <span class="hlt">plasma</span> thruster. A simple experiment would involve measuring the impulse bit of a coaxial gas-fed pulsed <span class="hlt">plasma</span> thruster operated in both positive...Princeton, NJ, 2002. [2] J. Marshal. Performance of a hydromagnetic <span class="hlt">plasma</span> gun . The Physics of Fluids, 3(1):134–135, January-February 1960. [3] R.G. Jahn...Jahn and K.E. Clark. A large dielecteic vacuum facility. AIAA Jour- nal, 1966. [16] L.C. Burkhardt and R.H. Lovberg. Current <span class="hlt">sheet</span> in a coaxial <span class="hlt">plasma</span></p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/6564631','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/6564631"><span><span class="hlt">Electron</span> channeling and EBIC studies of polycrystalline silicon <span class="hlt">sheets</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Tsuo, Y S; Matson, R J</p> <p>1984-05-01</p> <p><span class="hlt">Electron</span> channeling and EBIC studies have been performed on silicon <span class="hlt">sheets</span> grown by the edge-supported pulling (ESP) and low-angle silicon <span class="hlt">sheet</span> (LASS) processes. We have found that the dominant grain structure of the ESP <span class="hlt">sheets</span> is long, narrow grains with surface normals oriented near (011); grains with this structure tend to have better <span class="hlt">electronic</span> quality than random grains. We have also studied the twin-stabilized planar growth material of LASS <span class="hlt">sheets</span>. This material, grown at 200 cm/sup 2//min, is essentially single-crystal.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017CosRe..55...46F','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017CosRe..55...46F"><span>Structure of current and <span class="hlt">plasma</span> in current <span class="hlt">sheets</span> depending on the conditions of <span class="hlt">sheet</span> formation</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Frank, A. G.; Ostrovskaya, G. V.; Yushkov, E. V.; Artemyev, A. V.; Satunin, S. N.</p> <p>2017-01-01</p> <p>The structure of current <span class="hlt">sheets</span> created under laboratory conditions is characterized by a large variety, which depends substantially on the conditions under which the <span class="hlt">sheet</span> if formed. In this work, we present the results of an experimental study of the structure and evolution of current <span class="hlt">sheets</span> that were formed in magnetic configurations with a singular line of the X type. It has been shown that the change in the transverse magnetic field gradient, the strength of the longitudinal magnetic field, and the mass of the ions in <span class="hlt">plasma</span> makes it possible to significantly vary the main parameters of the current <span class="hlt">sheets</span>. This offers the challenges of using laboratory experimental results for analyzing and simulating the cosmophysical processes.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014AGUFMSM11B..06S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014AGUFMSM11B..06S"><span>Thick Bifurcated Current <span class="hlt">Sheet</span> in the Near-Earth Tail <span class="hlt">Plasma</span> <span class="hlt">Sheet</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Saito, M.</p> <p>2014-12-01</p> <p>The bifurcated structure of the current <span class="hlt">sheet</span> in the mid tail (X~-20 RE) has been reported in several in-situ observational studies. The presented study examines a spatial distribution of current densities that statistically infer a thick bifurcated current <span class="hlt">sheet</span> as a typical structure in the near-Earth tail (X=-8 to -12 RE). The current density is evaluated by using any two of THEMIS spacecraft measurements when certain conditions, such as spacecraft separation and orientation, are strictly met. A survey from 2007 to 2013 results in approximately 3000 current densities, which made it possible to study north-south profile of the current <span class="hlt">sheet</span>. The peak of the current density is often found 0.5 RE to 1 RE off the magnetic equator, while the median half-thickness of the current <span class="hlt">sheet</span> is approximately 3 RE. These indicate that the current <span class="hlt">sheet</span> is thick and bifurcated on average. Presumably, owing to this non-uniform profile, local current densities sometimes become very intense. The intense current density preferentially occurs during growth phase and expansion phase of substorms, but also occur in quiet time. The intense current densities are found to be independent from the solar wind dynamic pressure. It is concluded that the intense current density is not caused by the compression of the <span class="hlt">plasma</span> <span class="hlt">sheet</span>. Other mechanisms need to be suggested to fully understand the structure and the evolution of the current <span class="hlt">sheet</span> in the near-Earth tail.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1984GMS....30...51R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1984GMS....30...51R"><span>Global single ion effects within the Earth's <span class="hlt">plasma</span> <span class="hlt">sheet</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Rothwell, Paul L.; Yates, G. Kenneth</p> <p></p> <p>Two global properties of single ion motion in the magnetotail are examined. The first effect is caused by the magnetic field in the <span class="hlt">plasma</span> <span class="hlt">sheet</span> directing boundary ions to the neutral <span class="hlt">sheet</span>. Exact solutions to the Lorentz equation indicate that these ions can have sufficient energy to trigger the ion tearing mode if Bo/aBz > 6.0, where Bo is the tail lobe magnetic field, Bz is the magnetic field in the north-south direction and `a' is a parameter related to the growth of the ion tearing instability. It is found that this effect occurs at a lower energy for oxygen than for protons. The second global property is related to the thinning or expansion of the <span class="hlt">plasma</span> <span class="hlt">sheet</span>. The results indicate that in the absence of reconnection the <span class="hlt">plasma</span> <span class="hlt">sheet</span> adiabatically maintains equilibruim by allowing <span class="hlt">plasma</span> and magnetic flux to cross the boundaries. The presence of reconnection modifies the flow across the boundaries as well as the spatial distribution of the induced electric field.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1984GMS.........51R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1984GMS.........51R"><span>Global single ion effects within the earth's <span class="hlt">plasma</span> <span class="hlt">sheet</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Rothwell, P. L.; Yates, G. K.</p> <p></p> <p>Two global properties of single-ion motion in the magnetotail are examined. The first effect is caused by the magnetic field in the <span class="hlt">plasma</span> <span class="hlt">sheet</span> directing boundary ions to the neutral <span class="hlt">sheet</span>. Exact solutions to the Lorentz equation indicate that these ions can have sufficient energy to trigger the ion tearing mode if B0/aBz is greater than 6.0, where B0 is the tail-lobe magnetic field, Bz is the magnetic field in the north-south direction, and a is a parameter related to the growth of the ion tearing instability. It is found that this effect occurs at a lower energy for oxygen than for protons. The second global property is related to the thinning or expansion of the <span class="hlt">plasma</span> <span class="hlt">sheet</span>. In the absence of reconnection, the <span class="hlt">plasma</span> <span class="hlt">sheet</span> adiabatically maintains equilibrium by allowing <span class="hlt">plasma</span> and magnetic flux to cross the boundaries. The presence of reconnection modifies the flow across the boundaries as well as the spatial distribution of the induced electric field.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19890000538&hterms=galvanometer&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3Dgalvanometer','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19890000538&hterms=galvanometer&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3Dgalvanometer"><span><span class="hlt">Electronic</span> Rotator For <span class="hlt">Sheet</span> Of Laser Light</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Franke, John M.; Rhodes, David B.; Leighty, Bradley D.; Jones, Stephen B.</p> <p>1989-01-01</p> <p>Primary flow-visualization system in Basic Aerodynamic Research Tunnel (BART) at NASA Langley Research Center is <span class="hlt">sheet</span> of laser light generated by 5-W argon-ion laser and two-axis mirror galvanometer scanner. Generates single and multiple <span class="hlt">sheets</span> of light, which remain stationary or driven to sweep out volume. Sine/cosine potentiometer used to orient two galvanometer/mirror devices simultaneously and yields desired result at reasonable cost and incorporated into prototype in 1 day.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20040086547','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20040086547"><span>Substorm Evolution in the Near-Earth <span class="hlt">Plasma</span> <span class="hlt">Sheet</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Erickson, Gary M.</p> <p>2004-01-01</p> <p>This grant represented one-year, phase-out funding for the project of the same name (NAG5-9110 to Boston University) to determine precursors and signatures of local substorm onset and how they evolve in the <span class="hlt">plasma</span> <span class="hlt">sheet</span> using the Geotail near-Earth database. We report here on two accomplishments: (1) Completion of an examination of <span class="hlt">plasma</span> velocity signature at times of local onsets in the current disruption (CD) region. (2) Initial investigation into quantification of near-Earth flux-tube contents of injected <span class="hlt">plasma</span> at times of substorm injections.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014IJMPS..3260339R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014IJMPS..3260339R"><span>Enhancement mechanism of H- production and suitable configurations for materials processing in a magnetized <span class="hlt">sheet</span> <span class="hlt">plasma</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ramos, Henry J.; Villamayor, Michelle Marie S.; Mella, Aubrey Faith M.; Salamania, Janella Mae R.; Villanueva, Matthew Bryan P.; Viloan, Rommel Paulo B.</p> <p>2014-08-01</p> <p>A magnetized <span class="hlt">sheet</span> <span class="hlt">plasma</span> ion source was developed for steady state high density <span class="hlt">plasma</span> with strong density and high temperature gradients. This feature provides efficient formation of negative hydrogen (H-) ions over a wide beam extraction area through the <span class="hlt">electron</span> volume process. A hexapole confinement at the cathode, addition of argon and magnesium seeding led to the increase of H- yield. The device configuration is suitable for <span class="hlt">plasma</span> based materials processing namely, synthesis of TiN, SiH, SnO2, and the formation of advanced MAX phase materials Ti2AlC, Ti2CdC and NbAlC.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19830050312&hterms=ONG&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3DONG','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19830050312&hterms=ONG&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3DONG"><span>Excitation of an electrostatic wave by a cold <span class="hlt">electron</span> current <span class="hlt">sheet</span> of finite thickness</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Hwang, K. S.; Fontheim, E. G.; Ong, R. S. B.</p> <p>1983-01-01</p> <p>Calculations for the threshold of current-driven instabilities and the growth rates of ion acoustic and electrostatic ion cyclotron instabilities in a magnetized <span class="hlt">plasma</span> driven a current <span class="hlt">sheet</span> with a finite width are presented. Maxwellian equations are employed to model the velocity distributions of <span class="hlt">electrons</span> and ions in a direction perpendicular to the <span class="hlt">sheet</span>. A dispersion relation is defined for the regions of instability, and boundary conditions are characterized in order to obtain a set of eigenvalue equations. Thresholds are delineated for various regions, including ducted mode solutions where only ion-acoustic waves are excited in areas where the frequency range significantly exceeds the ion cyclotron frequency. When a constant <span class="hlt">electron</span> drift velocity is present, a thick current <span class="hlt">sheet</span> is more unstable than a thin one. Fewer modes become unstable with a thinner <span class="hlt">sheet</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19890046144&hterms=plasma+Composition+Experiment&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3Dplasma%2BComposition%2BExperiment','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19890046144&hterms=plasma+Composition+Experiment&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3Dplasma%2BComposition%2BExperiment"><span>Comparison of <span class="hlt">plasma</span> <span class="hlt">sheet</span> ion composition with the IMF and solar wind <span class="hlt">plasma</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Lennartsson, W.</p> <p>1988-01-01</p> <p><span class="hlt">Plasma</span> <span class="hlt">sheet</span> energetic ion data (0.1- to 16 keV/e) obtained by the <span class="hlt">Plasma</span> Composition Experiment on ISEE-1 between 10 and 23 earth radii are compared with concurrent IMF and solar wind <span class="hlt">plasma</span> data. The densities of H(+) and He(++) ions in the <span class="hlt">plasma</span> <span class="hlt">sheet</span> are found to be the highest, and the most nearly proportional to the solar wind density, when the IMF B(z) is not northward. The density of terrestrial O(+) ions increases strongly with increasing magnitude of the IMF, in apparent agreement with the notion that the IMF plays a fundamental role in the electric coupling between the solar wind and the ionosphere.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1988AdSpR...8..135L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1988AdSpR...8..135L"><span>Comparison of <span class="hlt">plasma</span> <span class="hlt">sheet</span> ion composition with the IMF and solar wind <span class="hlt">plasma</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Lennartsson, W.</p> <p></p> <p><span class="hlt">Plasma</span> <span class="hlt">sheet</span> energetic ion data (0.1- to 16 keV/e) obtained by the <span class="hlt">Plasma</span> Composition Experiment on ISEE-1 between 10 and 23 earth radii are compared with concurrent IMF and solar wind <span class="hlt">plasma</span> data. The densities of H(+) and He(++) ions in the <span class="hlt">plasma</span> <span class="hlt">sheet</span> are found to be the highest, and the most nearly proportional to the solar wind density, when the IMF B(z) is not northward. The density of terrestrial O(+) ions increases strongly with increasing magnitude of the IMF, in apparent agreement with the notion that the IMF plays a fundamental role in the electric coupling between the solar wind and the ionosphere.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19950029531&hterms=physique&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D60%26Ntt%3Dphysique','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19950029531&hterms=physique&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D60%26Ntt%3Dphysique"><span>Contribution of low-energy ionospheric protons to the <span class="hlt">plasma</span> <span class="hlt">sheet</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Delcourt, D. C.; Moore, T. E.; Chappell, C. R.</p> <p>1994-01-01</p> <p>The magnetospheric transport of low-energy ionospheric ions is examined by means of three-dimensional particle codes. Emphasis is placed on the behavior of polar wind and cleft originating protons. It is demonstrated that, via nonadiabatic motion inside the neutral <span class="hlt">sheet</span>, these ions can significantly contribute to the populations of the <span class="hlt">plasma</span> <span class="hlt">sheet</span>. The importance of this contribution is found to depend critically upon the dynamics of particles originating from the highest latitudes, as these possibly have access to the distant tail. Hence it is shown that polar wind H(+) expelled into the magnetosphere at very low energies (in the <span class="hlt">electron</span> volt range) preferentially feed the <span class="hlt">plasma</span> <span class="hlt">sheet</span> during quiet times, experiencing accelerations up to several kiloelectron volts upon return into the inner magnetosphere. In contrast, during disturbed times, the intensifying magnetospheric convection confines this population to low L shells where it travels in a nearly adiabatic manner. As for the protons originating from the cleft fountain, the simulations reveal that they can be transported up to the vicinity of the distant neutral line in the nightside sector. Via interaction with the neutral <span class="hlt">sheet</span>, these ionospheric ions are rapidly raised to the characteristic <span class="hlt">plasma</span> <span class="hlt">sheet</span> energy range. The density levels contributed by these populations are quite substantial when compared to those measured in situ. These simulations establish an active role of low-energy ionospheric ions in the overall magnetospheric dynamics.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015JGRA..120..432M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015JGRA..120..432M"><span>On a possible connection between the longitudinally propagating near-Earth <span class="hlt">plasma</span> <span class="hlt">sheet</span> and auroral arc waves: A reexamination</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Motoba, T.; Ohtani, S.; Donovan, E. F.; Angelopoulos, V.</p> <p>2015-01-01</p> <p>propagating low-frequency waves (or wavy structures) often occur in a localized region of the near-Earth <span class="hlt">plasma</span> <span class="hlt">sheet</span> and auroral arc immediately prior to auroral breakup. Although both are believed to be magnetospheric and ionospheric manifestations of a <span class="hlt">plasma</span> <span class="hlt">sheet</span> instability that may lead to substorm onset, the fundamental coupling processes behind their relationship are not yet understood. To address this question, we reexamined in detail a fortuitous conjunction event of prebreakup near-Earth <span class="hlt">plasma</span> <span class="hlt">sheet</span> and auroral arc waves, initially reported by Uritsky et al. (2009) using the Time History of Events and Macroscale Interactions during Substorms space-ground observations. The event exhibited a morphological one-to-one association between longitudinally propagating arc wave (LPAW) in the ionosphere and Pi2/Pc4 range wave activity in the <span class="hlt">plasma</span> <span class="hlt">sheet</span>. Our analysis revealed that (1) the LPAW was the periodic luminosity modulation of the growth phase arc by faint, diffuse, green line-dominated auroral patches propagating westward along/near the arc, rather than some type of small-scale arc structuring, such as auroral beads/rays/undulations; and (2) the <span class="hlt">plasma</span> <span class="hlt">sheet</span> wave, which had a diamagnetic nature, propagated duskward with accompanying coincident modulation of field-aligned fluxes of 0.1-30 keV <span class="hlt">electrons</span>. These findings suggest that the LPAW was likely connected to the <span class="hlt">plasma</span> <span class="hlt">sheet</span> wave via modulated diffuse precipitation of hard <span class="hlt">plasma</span> <span class="hlt">sheet</span> <span class="hlt">electrons</span> (> ~1 keV), not via filamentary field-aligned currents, as expected from the ballooning instability regime. Another potential implication is that such prebreakup low-frequency wave activity in the near-Earth <span class="hlt">plasma</span> <span class="hlt">sheet</span> is not necessarily guaranteed to initiate prebreakup auroral arc structuring.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015JGRA..120.4487Z','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015JGRA..120.4487Z"><span>Earthward and tailward flows in the <span class="hlt">plasma</span> <span class="hlt">sheet</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Zhang, L. Q.; Wang, J. Y.; Baumjohann, W.; Rème, H.; Dunlop, M. W.</p> <p>2015-06-01</p> <p>Utilizing C3/Cluster satellite observations from the year of 2001 to 2006, we investigated the earthward flow (EF) and tailward flow (TF) at Bz > 0 in the <span class="hlt">plasma</span> <span class="hlt">sheet</span>. We found that the EF and the TF have similar spatial distributions. Both characteristics are independent of the distance beyond 14 RE. Both flows are deflected while closer to the Earth. Statistical results further showed that the EF/TF occur in the central <span class="hlt">plasma</span> <span class="hlt">sheet</span> as well as the <span class="hlt">plasma</span> <span class="hlt">sheet</span> boundary layer and can be observed during quiet times and periods of geomagnetic activity. A typical event reveals that the EF and the TF have different <span class="hlt">plasma</span> population. A transition region (TR) can be formed at the interface between the EF and TF. Very significant duskward components appeared in bulk velocities for both populations. It appears that the vortical-like structure can be formed near the TR. The magnetic field within the TR is twisted and strongly fluctuates. No clear magnetic flux pileups are observed inside the TR.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_3");'>3</a></li> <li><a href="#" onclick='return showDiv("page_4");'>4</a></li> <li class="active"><span>5</span></li> <li><a href="#" onclick='return showDiv("page_6");'>6</a></li> <li><a href="#" onclick='return showDiv("page_7");'>7</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_5 --> <div id="page_6" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_4");'>4</a></li> <li><a href="#" onclick='return showDiv("page_5");'>5</a></li> <li class="active"><span>6</span></li> <li><a href="#" onclick='return showDiv("page_7");'>7</a></li> <li><a href="#" onclick='return showDiv("page_8");'>8</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="101"> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19800030841&hterms=observation+spatiale&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D60%26Ntt%3Dobservation%2Bspatiale','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19800030841&hterms=observation+spatiale&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D60%26Ntt%3Dobservation%2Bspatiale"><span>ISEE 1 and 2 particle observations of outer <span class="hlt">plasma</span> <span class="hlt">sheet</span> boundary</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Parks, G. K.; Lin, C. S.; Anderson, K. A.; Lin, R. P.; Reme, H.</p> <p>1979-01-01</p> <p>Observations of particle structures by a medium-energy particle experiment on the ISEE 1 and 2 spacecraft at a distance of about 20 earth radii in the geomagnetic tail are presented. Comparison of these data with <span class="hlt">plasma</span> data indicates the existence of a layer of energetic <span class="hlt">electrons</span> and ions just outside the <span class="hlt">plasma</span> <span class="hlt">sheet</span>. The region outside the <span class="hlt">plasma</span> <span class="hlt">sheet</span> in the high-latitude lobe is permeated with low-intensity low-energy (about 1.5 KeV) ions. These particle structures have velocities of a few kilometers per second to at least about 60 km/s. Large-scale motions are observed with onset and recovery of substorms. The dimensions of the particle structures are estimated to range from about 200 to 10,000 km at 20 earth radii. The particle structures are dependent upon the energy as well as the species of the particles.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/22472206','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/22472206"><span>Current <span class="hlt">sheet</span> in <span class="hlt">plasma</span> as a system with a controlling parameter</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Fridman, Yu. A. Chukbar, K. V.</p> <p>2015-08-15</p> <p>A simple kinetic model describing stationary solutions with bifurcated and single-peaked current density profiles of a plane <span class="hlt">electron</span> beam or current <span class="hlt">sheet</span> in <span class="hlt">plasma</span> is presented. A connection is established between the two-dimensional constructions arising in terms of the model and the one-dimensional considerations by Bernstein−Greene−Kruskal facilitating the reconstruction of the distribution function of trapped particles when both the profile of the electric potential and the free particles distribution function are known.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015REDS..170..970Y','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015REDS..170..970Y"><span>Analysis of radiation performances of <span class="hlt">plasma</span> <span class="hlt">sheet</span> antenna</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Yin, Bo; Zhang, Zu-Fan; Wang, Ping</p> <p>2015-12-01</p> <p>A novel concept of <span class="hlt">plasma</span> <span class="hlt">sheet</span> antennas is presented in this paper, and the radiation performances of <span class="hlt">plasma</span> <span class="hlt">sheet</span> antennas are investigated in detail. Firstly, a model of planar <span class="hlt">plasma</span> antenna (PPA) fed by a microstrip line is developed, and its reflection coefficient is computed by the JE convolution finite-difference time-domain method and compared with that of the metallic patch antenna. It is found that the design of PPA can learn from the theory of the metallic patch antenna, and the impedance matching and reconstruction of resonant frequency can be expediently realized by adjusting the parameters of <span class="hlt">plasma</span>. Then the PPA is mounted on a metallic cylindrical surface, and the reflection coefficient of the conformal <span class="hlt">plasma</span> antenna (CPA) is also computed. At the same time, the influence of conformal cylinder radius on the reflection coefficient is also analyzed. Finally, the radiation pattern of a CPA is given, the results show that the pattern agrees well with the one of PPA in the main radiation direction, but its side lobe level has deteriorated significantly.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016PSST...25a5013T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016PSST...25a5013T"><span>On the <span class="hlt">plasma</span>-based growth of ‘flowing’ graphene <span class="hlt">sheets</span> at atmospheric pressure conditions</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Tsyganov, D.; Bundaleska, N.; Tatarova, E.; Dias, A.; Henriques, J.; Rego, A.; Ferraria, A.; Abrashev, M. V.; Dias, F. M.; Luhrs, C. C.; Phillips, J.</p> <p>2016-02-01</p> <p>A theoretical and experimental study on atmospheric pressure microwave <span class="hlt">plasma</span>-based assembly of free standing graphene <span class="hlt">sheets</span> is presented. The synthesis method is based on introducing a carbon-containing precursor (C2H5OH) through a microwave (2.45 GHz) argon <span class="hlt">plasma</span> environment, where decomposition of ethanol molecules takes place and carbon atoms and molecules are created and then converted into solid carbon nuclei in the ‘colder’ nucleation zones. A theoretical model previously developed has been further updated and refined to map the particle and thermal fluxes in the <span class="hlt">plasma</span> reactor. Considering the nucleation process as a delicate interplay between thermodynamic and kinetic factors, the model is based on a set of non-linear differential equations describing <span class="hlt">plasma</span> thermodynamics and chemical kinetics. The model predictions were validated by experimental results. Optical emission spectroscopy was applied to detect the <span class="hlt">plasma</span> emission related to carbon species from the ‘hot’ <span class="hlt">plasma</span> zone. Raman spectroscopy, scanning <span class="hlt">electron</span> microscopy (SEM), and x-ray photoelectron spectroscopy (XPS) techniques have been applied to analyze the synthesized nanostructures. The microstructural features of the solid carbon nuclei collected from the colder zones of <span class="hlt">plasma</span> reactor vary according to their location. A part of the solid carbon was deposited on the discharge tube wall. The solid assembled from the main stream, which was gradually withdrawn from the hot <span class="hlt">plasma</span> region in the outlet <span class="hlt">plasma</span> stream directed to a filter, was composed by ‘flowing’ graphene <span class="hlt">sheets</span>. The influence of additional hydrogen, Ar flow rate and microwave power on the concentration of obtained stable species and carbon-dicarbon was evaluated. The ratio of sp3/sp2 carbons in graphene <span class="hlt">sheets</span> is presented. A correlation between changes in C2 and C number densities and sp3/sp2 ratio was found.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/20192448','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/20192448"><span><span class="hlt">Electron</span> cyclotron resonance <span class="hlt">plasma</span> photos.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Rácz, R; Biri, S; Pálinkás, J</p> <p>2010-02-01</p> <p>In order to observe and study systematically the <span class="hlt">plasma</span> of <span class="hlt">electron</span> cyclotron resonance (ECR) ion sources (ECRIS) we made a high number of high-resolution visible light <span class="hlt">plasma</span> photos and movies in the ATOMKI ECRIS Laboratory. This required building the ECR ion source into an open ECR <span class="hlt">plasma</span> device, temporarily. An 8MP digital camera was used to record photos of <span class="hlt">plasmas</span> made from Ne, Ar, and Kr gases and from their mixtures. We studied and recorded the effect of ion source setting parameters (gas pressure, gas composition, magnetic field, and microwave power) to the shape, color, and structure of the <span class="hlt">plasma</span>. The analysis of the photo series gave us many qualitative and numerous valuable physical information on the nature of ECR <span class="hlt">plasmas</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/22053894','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/22053894"><span><span class="hlt">Electron</span> cyclotron resonance <span class="hlt">plasma</span> photos</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Racz, R.; Palinkas, J.; Biri, S.</p> <p>2010-02-15</p> <p>In order to observe and study systematically the <span class="hlt">plasma</span> of <span class="hlt">electron</span> cyclotron resonance (ECR) ion sources (ECRIS) we made a high number of high-resolution visible light <span class="hlt">plasma</span> photos and movies in the ATOMKI ECRIS Laboratory. This required building the ECR ion source into an open ECR <span class="hlt">plasma</span> device, temporarily. An 8MP digital camera was used to record photos of <span class="hlt">plasmas</span> made from Ne, Ar, and Kr gases and from their mixtures. We studied and recorded the effect of ion source setting parameters (gas pressure, gas composition, magnetic field, and microwave power) to the shape, color, and structure of the <span class="hlt">plasma</span>. The analysis of the photo series gave us many qualitative and numerous valuable physical information on the nature of ECR <span class="hlt">plasmas</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/6736944','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/6736944"><span>Large scale instabilities and dynamics of the magnetotail <span class="hlt">plasma</span> <span class="hlt">sheet</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Birn, J.; Schindler, K.</p> <p>1986-01-01</p> <p>The stability properties of the magnetotail current <span class="hlt">sheet</span> against large scale modes is reviewed in the framework of ideal MHD, resistive MHD, and collisionless Vlasov theory. It appears that the small deviations from a plane <span class="hlt">sheet</span> pinch (in particular a magnetic field component normal to the <span class="hlt">sheet</span>) are important to explain the transition of the tail from a quiet stable state to an unstable dynamic state. It is found that the tail is essentially stable in ideal MHD, but unstable in resistive MHD, while both stable and unstable configurations are found within collisionless theory. The results favor an interpretation where the onset of magnetotail dyanmics leading to a sudden thinning of the <span class="hlt">plasma</span> <span class="hlt">sheet</span> and the ejection of a plasmoid is caused by the onset of a collisionless instability that either directly leads to the growth of a collisionless tearing mode or via microscopic turbulence to the growth of a resistive mode. The actual onset conditions are not fully explored yet by rigorous methods. The onset may be triggered by local conditions as well as by boundary conditions at the ionosphere or at the magnetopause (resulting from solar wind conditions). 53 refs., 5 figs.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014GeoRL..41.8185C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014GeoRL..41.8185C"><span>Heating of the <span class="hlt">plasma</span> <span class="hlt">sheet</span> by broadband electromagnetic waves</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Chaston, C. C.; Bonnell, J. W.; Salem, C.</p> <p>2014-12-01</p> <p>We demonstrate that broadband low-frequency electromagnetic field fluctuations embedded within fast flows throughout the Earth's <span class="hlt">plasma</span> <span class="hlt">sheet</span> may drive significant ion heating. This heating is nearly entirely in the direction perpendicular to the background magnetic field and is estimated to occur at an average rate of ~1 eV/s with rates in excess of 10 eV/s within one standard deviation of the average value over all observed events. For an Earthward flow the total change in temperature along a flow path may exceed one keV and for "wave-rich" flows can be comparable to that expected due to conservation of the first adiabatic invariant. The consequent increase in <span class="hlt">plasma</span> pressure and flux tube entropy may lead to braking of inward motion and the suppression of <span class="hlt">plasma</span> interchange.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19910040943&hterms=cps&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D60%26Ntt%3Dcps','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19910040943&hterms=cps&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D60%26Ntt%3Dcps"><span><span class="hlt">Plasma</span> convection and ion beam generation in the <span class="hlt">plasma</span> <span class="hlt">sheet</span> boundary layer</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Moghaddam-Taaheri, E.; Goertz, C. K.; Smith, R. A.</p> <p>1991-01-01</p> <p>Because of the dawn-dusk electric field E(dd), <span class="hlt">plasma</span> in the magnetotail convects from the lobe toward the central <span class="hlt">plasma</span> <span class="hlt">sheet</span> (CPS). In the absence of space or velocity diffusion due to <span class="hlt">plasma</span> turbulence, convection would yield a steady state distribution function f = V exp (-2/3) g(v exp 2 V exp 2/3), where V is the flux tube volume. Starting with such a distribution function and a <span class="hlt">plasma</span> beta which varies from beta greater than 1 in the CPS to beta much smaller than 1 in the lobe, the evolution of the ion distribution function was studied considering the combined effects of ion diffusion by kinetic Alfven waves (KAW) in the ULF frequency range (1-10 mHz) and convection due to E(dd) x B drift in the <span class="hlt">plasma</span> <span class="hlt">sheet</span> boundary layer (PSBL) and outer central <span class="hlt">plasma</span> <span class="hlt">sheet</span> (OCPS). The results show that, during the early stages after launching the KAWs, a beamlike ion distribution forms in the PSBL and at the same time the <span class="hlt">plasma</span> density and temperature decrease in the OCPS. Following this stage, ions in the beams convect toward the CPS resulting in an increase of the <span class="hlt">plasma</span> temperature in the OCPS.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/21432199','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/21432199"><span>Conditions for the formation of nongyrotropic current <span class="hlt">sheets</span> in slowly evolving <span class="hlt">plasmas</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Schindler, Karl; Hesse, Michael</p> <p>2010-08-15</p> <p>This paper addresses the formation of nongyrotropic current <span class="hlt">sheets</span> resulting from slow external driving. The medium is a collisionless <span class="hlt">plasma</span> with one spatial dimension and a three-dimensional velocity space. The study is based on particle simulation and an analytical approach. Earlier results that apply to compression of an initial Harris <span class="hlt">sheet</span> are generalized in several ways. In a first step a general sufficient criterion for the presence of extra ion and <span class="hlt">electron</span> currents due to nongyrotropic <span class="hlt">plasma</span> conditions is derived. Then cases with antisymmetric magnetic and electric fields are considered. After establishing consistency of the criterion with the earlier case, the usefulness of this concept is illustrated in detail by two further particle simulations. The results indicate that the formation of nongyrotropic current <span class="hlt">sheets</span> is a ubiquitous phenomenon for <span class="hlt">plasmas</span> with antisymmetric fields that have evolved slowly from initial gyrotropic states. A fourth case concerns a <span class="hlt">plasma</span> with a unidirectional magnetic field. Consistent with the general criterion, the observed final state is fluidlike in that it is approximately gyrotropic. Momentum balance is shown to include a contribution that results from accumulation of an off-diagonal pressure tensor component during the evolution. Heat flux also plays an important role.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1993JGR....98.3999H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1993JGR....98.3999H"><span>The Uranian corona as a charge exchange cascade of <span class="hlt">plasma</span> <span class="hlt">sheet</span> protons</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Herbert, F.</p> <p>1993-03-01</p> <p>The paper uses models of magnetic convection and interparticle interactions to examine the collisional interactions between atmospheric neutral hydrogen and magnetospheric charged particles observed by Voyager to be convecting through the Uranian magnetosphere. The e(-)-H collisional ionization process, continually reenergized by compressional heating of the <span class="hlt">electrons</span> as they drift toward Uranus, produces a cascade of new <span class="hlt">plasma</span>. This process has been suggested elsewhere as the source of the warm (10 eV at L = 5) <span class="hlt">plasma</span> and is found in the present study to continue in a cascade to even cooler and more abundant <span class="hlt">plasma</span>. This newly created <span class="hlt">plasma</span> consists almost entirely of <span class="hlt">electrons</span> and protons because He and H2 are nearly absent from the uppermost layers of the atmosphere. If this <span class="hlt">plasma</span> crosses the dayside magnetopause and mixes with magnetopause boundary layers such as the <span class="hlt">plasma</span> mantle, there to be swept back along the magnetotail, reincorporated into the magnetotail by the same processes postulated for solar wind <span class="hlt">plasma</span> entry, and reenergized in the magnetotail current <span class="hlt">sheet</span>, it would constitute an important source for the hot <span class="hlt">plasma</span> observed by Voyager.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1986AnGeo...4..391O','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1986AnGeo...4..391O"><span>Composition and <span class="hlt">plasma</span> properties of the <span class="hlt">plasma</span> <span class="hlt">sheet</span> in the earth's magnetotail</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Orsini, S.; Altwegg, K.; Balsiger, H.</p> <p>1986-10-01</p> <p>Using 300 h of <span class="hlt">plasma</span> <span class="hlt">sheet</span> observations obtained by the ISEE-1 Ion Composition Experiment in 1978, H(+) and He(2+) densities and temperatures are investigated as functions of magnetospheric substorm activity and geocentric distance. Temperatures of H(+) and He(2+) are well correlated with an average ratio of 2.7 + or - 0.1, though linear regression for high activity periods suggests a nonvanishing T(He2+) in the limit as T(H+) approaches 0. <span class="hlt">Plasma</span> <span class="hlt">sheet</span> ion temperatures vary directly with geomagnetic activity and inversely with geocentric distance, while the N(He2+)/N(H+) ratio increases with geocentric distance irrespective of the activity index.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19800024817','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19800024817"><span>Survey of the <span class="hlt">plasma</span> <span class="hlt">electron</span> environment of Jupiter: A view from Voyager</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Scudder, J. D.; Sittler, E. C., Jr.; Bridge, H. S.</p> <p>1980-01-01</p> <p>The <span class="hlt">plasma</span> environment within Jupiter's bow shock is considered in terms of the in situ, calibrated <span class="hlt">electron</span> <span class="hlt">plasma</span> measurements made between 10 eV and 5.95 keV by the Voyager <span class="hlt">plasma</span> science experiment (PLS). Measurements were analyzed and corrected for spacecraft potential variations; the data were reduced to nearly model independent macroscopic parameters of the local <span class="hlt">electron</span> density and temperature. It is tentatively concluded that the radial temperature profile within the <span class="hlt">plasma</span> <span class="hlt">sheet</span> is caused by the intermixing of two different <span class="hlt">electron</span> populations that probably have different temporal histories and spatial paths to their local observation. The cool <span class="hlt">plasma</span> source of the <span class="hlt">plasma</span> <span class="hlt">sheet</span> and spikes is probably the Io <span class="hlt">plasma</span> torus and arrives in the <span class="hlt">plasma</span> <span class="hlt">sheet</span> as a result of flux tube interchange motions or other generalized transport which can be accomplished without diverting the <span class="hlt">plasma</span> from the centrifugal equator. The hot suprathermal populations in the <span class="hlt">plasma</span> <span class="hlt">sheet</span> have most recently come from the sparse, hot mid-latitude "bath" of <span class="hlt">electrons</span> which were directly observed juxtaposed to the <span class="hlt">plasma</span> <span class="hlt">sheet</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/5221552','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/5221552"><span>Evolution of magnetic configurations in the <span class="hlt">plasma</span> <span class="hlt">sheet</span> during a substorm on March 19, 1978</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Sun, W.; Kan, J.R.; Akasofu, S.I. )</p> <p>1991-09-01</p> <p>Evolution of the magnetic field configuration in the <span class="hlt">plasma</span> <span class="hlt">sheet</span> is modeled for an intense substorm event on March 19, 1978. The model is based on the idea that the substorm enhanced field-aligned currents are initiated in the ionosphere in response to an enhanced magnetospheric convection. The field-aligned currents in the model are determined from the ground-based magnetometer data with a time resolution of 5 min. The substorm field-aligned currents are assumed to close in the <span class="hlt">plasma</span> <span class="hlt">sheet</span> to complete the substorm current circuit. It is shown that the magnetic field produced by the substorm current system in the model can reproduce several important substorm signatures observed in the <span class="hlt">plasma</span> <span class="hlt">sheet</span>. These signatures include the taillike reconfiguration in the <span class="hlt">plasma</span> <span class="hlt">sheet</span> during the growth phase, the dipolarization of the <span class="hlt">plasma</span> <span class="hlt">sheet</span> associated with the substorm expansion onset, and the formation of a new X line. A shortcoming of the model is that the <span class="hlt">plasma</span> dynamics in the <span class="hlt">plasma</span> <span class="hlt">sheet</span> have been ignored. In spite of this shortcoming, however, the model demonstrates that the ionosphere, in response to an enhanced magnetospheric convection, can cause the <span class="hlt">plasma</span> <span class="hlt">sheet</span> to change its magnetic configuration to result in the substorm signatures observed in the <span class="hlt">plasma</span> <span class="hlt">sheet</span>. The present study shows that it is possible for the ionosphere to play an active role in causing the observed reconfigurations of the <span class="hlt">plasma</span> <span class="hlt">sheet</span> during substorms.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26074645','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26074645"><span>Increases in <span class="hlt">plasma</span> <span class="hlt">sheet</span> temperature with solar wind driving during substorm growth phases.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Forsyth, C; Watt, C E J; Rae, I J; Fazakerley, A N; Kalmoni, N M E; Freeman, M P; Boakes, P D; Nakamura, R; Dandouras, I; Kistler, L M; Jackman, C M; Coxon, J C; Carr, C M</p> <p>2014-12-28</p> <p>During substorm growth phases, magnetic reconnection at the magnetopause extracts ∼10(15) J from the solar wind which is then stored in the magnetotail lobes. <span class="hlt">Plasma</span> <span class="hlt">sheet</span> pressure increases to balance magnetic flux density increases in the lobes. Here we examine <span class="hlt">plasma</span> <span class="hlt">sheet</span> pressure, density, and temperature during substorm growth phases using 9 years of Cluster data (>316,000 data points). We show that <span class="hlt">plasma</span> <span class="hlt">sheet</span> pressure and temperature are higher during growth phases with higher solar wind driving, whereas the density is approximately constant. We also show a weak correlation between <span class="hlt">plasma</span> <span class="hlt">sheet</span> temperature before onset and the minimum SuperMAG AL (SML) auroral index in the subsequent substorm. We discuss how energization of the <span class="hlt">plasma</span> <span class="hlt">sheet</span> before onset may result from thermodynamically adiabatic processes; how hotter <span class="hlt">plasma</span> <span class="hlt">sheets</span> may result in magnetotail instabilities, and how this relates to the onset and size of the subsequent substorm expansion phase.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4459207','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4459207"><span>Increases in <span class="hlt">plasma</span> <span class="hlt">sheet</span> temperature with solar wind driving during substorm growth phases</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Forsyth, C; Watt, C E J; Rae, I J; Fazakerley, A N; Kalmoni, N M E; Freeman, M P; Boakes, P D; Nakamura, R; Dandouras, I; Kistler, L M; Jackman, C M; Coxon, J C; Carr, C M</p> <p>2014-01-01</p> <p>During substorm growth phases, magnetic reconnection at the magnetopause extracts ∼1015 J from the solar wind which is then stored in the magnetotail lobes. <span class="hlt">Plasma</span> <span class="hlt">sheet</span> pressure increases to balance magnetic flux density increases in the lobes. Here we examine <span class="hlt">plasma</span> <span class="hlt">sheet</span> pressure, density, and temperature during substorm growth phases using 9 years of Cluster data (>316,000 data points). We show that <span class="hlt">plasma</span> <span class="hlt">sheet</span> pressure and temperature are higher during growth phases with higher solar wind driving, whereas the density is approximately constant. We also show a weak correlation between <span class="hlt">plasma</span> <span class="hlt">sheet</span> temperature before onset and the minimum SuperMAG AL (SML) auroral index in the subsequent substorm. We discuss how energization of the <span class="hlt">plasma</span> <span class="hlt">sheet</span> before onset may result from thermodynamically adiabatic processes; how hotter <span class="hlt">plasma</span> <span class="hlt">sheets</span> may result in magnetotail instabilities, and how this relates to the onset and size of the subsequent substorm expansion phase. PMID:26074645</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/22299965','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/22299965"><span>Three dimensional instabilities of an <span class="hlt">electron</span> scale current <span class="hlt">sheet</span> in collisionless magnetic reconnection</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Jain, Neeraj; Büchner, Jörg</p> <p>2014-06-15</p> <p>In collisionless magnetic reconnection, <span class="hlt">electron</span> current <span class="hlt">sheets</span> (ECS) with thickness of the order of an <span class="hlt">electron</span> inertial length form embedded inside ion current <span class="hlt">sheets</span> with thickness of the order of an ion inertial length. These ECS's are susceptible to a variety of instabilities which have the potential to affect the reconnection rate and/or the structure of reconnection. We carry out a three dimensional linear eigen mode stability analysis of <span class="hlt">electron</span> shear flow driven instabilities of an <span class="hlt">electron</span> scale current <span class="hlt">sheet</span> using an <span class="hlt">electron</span>-magnetohydrodynamic <span class="hlt">plasma</span> model. The linear growth rate of the fastest unstable mode was found to drop with the thickness of the ECS. We show how the nature of the instability depends on the thickness of the ECS. As long as the half-thickness of the ECS is close to the <span class="hlt">electron</span> inertial length, the fastest instability is that of a translational symmetric two-dimensional (no variations along flow direction) tearing mode. For an ECS half thickness sufficiently larger or smaller than the <span class="hlt">electron</span> inertial length, the fastest mode is not a tearing mode any more and may have finite variations along the flow direction. Therefore, the generation of plasmoids in a nonlinear evolution of ECS is likely only when the half-thickness is close to an <span class="hlt">electron</span> inertial length.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017PhLA..381.1033B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017PhLA..381.1033B"><span>A simple <span class="hlt">electron</span> <span class="hlt">plasma</span> wave</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Brodin, G.; Stenflo, L.</p> <p>2017-03-01</p> <p>Considering a class of solutions where the density perturbations are functions of time, but not of space, we derive a new exact large amplitude wave solution for a cold uniform <span class="hlt">electron</span> <span class="hlt">plasma</span>. This result illustrates that most simple analytical solutions can appear even if the density perturbations are large.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19920045465&hterms=IRM&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3DIRM','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19920045465&hterms=IRM&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3DIRM"><span>Pressure changes in the <span class="hlt">plasma</span> <span class="hlt">sheet</span> during substorm injections</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Kistler, L. M.; Moebius, E.; Baumjohann, W.; Paschmann, G.; Hamilton, D. C.</p> <p>1992-01-01</p> <p>Data from the CHEM instrument on AMPTE CCE, data from the 3D <span class="hlt">plasma</span> instrument and the SULEICA instrument on AMPTE IRM, and magnetometer data from both spacecraft are used to determine the particle pressure and total pressure as a function of radial distance in the <span class="hlt">plasma</span> <span class="hlt">sheet</span> for periods before and after the onset of substorm-associated ion enhancements over the range 7-19 RE. Events were chosen that occurred during times of increasing magnetospheric activity, as determined by an increasing AE index, in which a sudden increase, or 'injection', of energetic particle flux is observed. It is shown that the simultaneous appearance of energetic particles and changes in the magnetic field results naturally from pressure balance and does not necessarily indicate that the local changing field is accelerating the particles.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/6907757','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/6907757"><span>Association of <span class="hlt">plasma</span> <span class="hlt">sheet</span> variations with auroral changes during substorms</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Hones, E.W. Jr.; Craven, J.D.; Frank, L.A.; Parks, G.K.</p> <p>1988-01-01</p> <p>Images of the southern auroral oval taken by the University of Iowa auroral imaging instrumentation on the Dynamics Explorer 1 satellite during an isolated substorm are correlated with <span class="hlt">plasma</span> measurements made concurrently by the ISEE 1 satellite in the magnetotail. Qualitative magnetic field configuration changes necessary to relate the <span class="hlt">plasma</span> <span class="hlt">sheet</span> boundary location to the latitude of the auroras are discussed. Evidence is presented that the longitudinal advances of the auroras after expansive phase onset are mappings of a neutral line lengthening across the near-tail. We observe a rapid poleward auroral surge, occurring about 1 hour after expansive phase onset, to coincide with the peak of the AL index and argue that the total set of observations at that time is consistent with the picture of a /open quotes/poleward leap/close quotes/ of the electrojet marking the beginning of the substorm's recovery. 9 refs. 3 figs.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_4");'>4</a></li> <li><a href="#" onclick='return showDiv("page_5");'>5</a></li> <li class="active"><span>6</span></li> <li><a href="#" onclick='return showDiv("page_7");'>7</a></li> <li><a href="#" onclick='return showDiv("page_8");'>8</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_6 --> <div id="page_7" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_5");'>5</a></li> <li><a href="#" onclick='return showDiv("page_6");'>6</a></li> <li class="active"><span>7</span></li> <li><a href="#" onclick='return showDiv("page_8");'>8</a></li> <li><a href="#" onclick='return showDiv("page_9");'>9</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="121"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/927792','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/927792"><span>A Gridded <span class="hlt">Electron</span> Gun for a <span class="hlt">Sheet</span> Beam Klystron</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Read, M.E.; Miram, G.; Ives, R.L.; Ivanov, V.; Krasnykh, A.; /SLAC</p> <p>2008-04-25</p> <p>This paper describes the development of an <span class="hlt">electron</span> gun for a <span class="hlt">sheet</span> beam klystron. Initially intended for accelerator applications, the gun can operate at a higher perveance than one with a cylindrically symmetric beam. Results of 2D and 3D simulations are discussed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016JGRA..12111129X','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016JGRA..12111129X"><span>Effects of auroral potential drops on <span class="hlt">plasma</span> <span class="hlt">sheet</span> dynamics</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Xi, Sheng; Lotko, William; Zhang, Binzheng; Wiltberger, Michael; Lyon, John</p> <p>2016-11-01</p> <p>The reaction of the magnetosphere-ionosphere system to dynamic auroral potential drops is investigated using the Lyon-Fedder-Mobarry global model including, for the first time in a global simulation, the dissipative load of field-aligned potential drops in the low-altitude boundary condition. This extra load reduces the field-aligned current (j||) supplied by nightside reconnection dynamos. The system adapts by forcing the nightside X line closer to Earth, with a corresponding reduction in current lensing (j||/B = constant) at the ionosphere and additional contraction of the <span class="hlt">plasma</span> <span class="hlt">sheet</span> during substorm recovery and steady magnetospheric convection. For steady and moderate solar wind driving and with constant ionospheric conductance, the cross polar cap potential and hemispheric field-aligned current are lower by approximately the ratio of the peak field-aligned potential drop to the cross polar cap potential (10-15%) when potential drops are included. Hemispheric ionospheric Joule dissipation is less by 8%, while the area-integrated, average work done on the fluid by the reconnecting magnetotail field increases by 50% within |y| < 8 RE. Effects on the nightside <span class="hlt">plasma</span> <span class="hlt">sheet</span> include (1) an average X line 4 RE closer to Earth; (2) a 12% higher mean reconnection rate; and (3) dawn-dusk asymmetry in reconnection with a 17% higher rate in the premidnight sector.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2002JPhD...35.1010C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2002JPhD...35.1010C"><span>Mechanisms of a linear hollow cathode used for the production of a helium <span class="hlt">plasma</span> <span class="hlt">sheet</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Caillault, L.; Larigaldie, S.</p> <p>2002-05-01</p> <p>A hollow-cathode device has been shown to operate as a <span class="hlt">plasma</span> reflector for radar <span class="hlt">electronic</span> beam steering using helium in the 0.2-0.5 Torr pressure range. Compared to former experiments, the use of this light gas reduces significantly spurious sputtering effect on the cathode materials. In a previous paper, a semi-quantitative physical model was developed to calculate the time evolution of the <span class="hlt">sheet</span> reflectivity from the experimental current Id(t) measured across the discharge. A self-consistent, numerical, stationary model is now developed to describe the main physical mechanisms that govern the hollow-cathode source. The model describes the coupling between the high-voltage collisional sheath and the magnetized <span class="hlt">plasma</span> through the hollow cathode. The cold <span class="hlt">electron</span> creation rate includes the efficiency of ionization from the fast secondary <span class="hlt">electrons</span> emitted from the surface of the cathode, lowered by the three-body recombination process in volume and by the ejection of a part of these fast <span class="hlt">electrons</span> out of the cathode <span class="hlt">plasma</span>. As the recombination rate scales as Te-9/2, the energy balance of the <span class="hlt">electrons</span> must be solved precisely, so that the collisional-radiative exchanges in Helium are included in the model. The results are then compared to the experimental V-I characteristics for different pressures of the neutral gas; there is good agreement between the theoretical <span class="hlt">plasma</span> model and the experiment.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19860040957&hterms=ISEE-3&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3DISEE-3','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19860040957&hterms=ISEE-3&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3DISEE-3"><span>ISEE 3 observations during a <span class="hlt">plasma</span> <span class="hlt">sheet</span> encounter at 140 earth radii - Evidence for enhancement of reconnection at the distant neutral line</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Scholer, M.; Terasawa, T.; Baker, D. N.; Zwickl, R. D.; Gloeckler, G.; Hovestadt, D.; Smith, E. J.; Tsurutani, B. T.</p> <p>1986-01-01</p> <p>A <span class="hlt">plasma</span> <span class="hlt">sheet</span> encounter of the ISEE-3 spacecraft in the distant tail at 140 earth radii on March 20, 1983 is studied using magnetic field, energetic particle, and <span class="hlt">plasma</span> <span class="hlt">electron</span> data sets. The H-component magnetograms from auroral magnetometer stations, intensity-time profiles, high resolution magnetic field measurements, and <span class="hlt">electron</span> and proton angular distributions are analyzed. The dynamics of the <span class="hlt">plasma</span> <span class="hlt">sheet</span> displayed by the strong tailward and earthward directed ion beams, large northward and southward magnetic fields excursions, and short tailward and earthward <span class="hlt">plasma</span> flows are described.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/27867235','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/27867235"><span>Transient, small-scale field-aligned currents in the <span class="hlt">plasma</span> <span class="hlt">sheet</span> boundary layer during storm time substorms.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Nakamura, R; Sergeev, V A; Baumjohann, W; Plaschke, F; Magnes, W; Fischer, D; Varsani, A; Schmid, D; Nakamura, T K M; Russell, C T; Strangeway, R J; Leinweber, H K; Le, G; Bromund, K R; Pollock, C J; Giles, B L; Dorelli, J C; Gershman, D J; Paterson, W; Avanov, L A; Fuselier, S A; Genestreti, K; Burch, J L; Torbert, R B; Chutter, M; Argall, M R; Anderson, B J; Lindqvist, P-A; Marklund, G T; Khotyaintsev, Y V; Mauk, B H; Cohen, I J; Baker, D N; Jaynes, A N; Ergun, R E; Singer, H J; Slavin, J A; Kepko, E L; Moore, T E; Lavraud, B; Coffey, V; Saito, Y</p> <p>2016-05-28</p> <p>We report on field-aligned current observations by the four Magnetospheric Multiscale (MMS) spacecraft near the <span class="hlt">plasma</span> <span class="hlt">sheet</span> boundary layer (PSBL) during two major substorms on 23 June 2015. Small-scale field-aligned currents were found embedded in fluctuating PSBL flux tubes near the separatrix region. We resolve, for the first time, short-lived earthward (downward) intense field-aligned current <span class="hlt">sheets</span> with thicknesses of a few tens of kilometers, which are well below the ion scale, on flux tubes moving equatorward/earthward during outward <span class="hlt">plasma</span> <span class="hlt">sheet</span> expansion. They coincide with upward field-aligned <span class="hlt">electron</span> beams with energies of a few hundred eV. These <span class="hlt">electrons</span> are most likely due to acceleration associated with a reconnection jet or high-energy ion beam-produced disturbances. The observations highlight coupling of multiscale processes in PSBL as a consequence of magnetotail reconnection.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1997JGR...10214381V','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1997JGR...10214381V"><span>Theory of quasi-monochromatic whistler wave generation in the inner <span class="hlt">plasma</span> <span class="hlt">sheet</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Villalón, Elena; Burke, William J.</p> <p>1997-07-01</p> <p>Nonlinear interactions between <span class="hlt">plasma</span> <span class="hlt">sheet</span> <span class="hlt">electrons</span> and nearly monochromatic whistler wave packets are studied. The theory applies to the generation of chorus emissions from quasi-monochromatic wavelets observed in the <span class="hlt">plasma</span> <span class="hlt">sheet</span> at the top of the ELF/VLF hiss band. The hiss-triggered chorus is produced by step-like deformations that develop in distribution functions at the boundaries between resonant and nonresonant <span class="hlt">electrons</span>. Equations are obtained describing the wave amplitudes and frequency-time characteristics for propagation at small angles with respect to the geomagnetic field. The linear resonant interactions leading to wavelet generation are investigated. The resonant wave frequencies change along the field lines to compensate for geomagnetic field inhomogeneities. If the electric fields exceed the amplitudes of those in the background plasmapheric hiss (>>10-6V/m), <span class="hlt">electrons</span> become trapped in phase space, and their distribution functions develop plateaus whose extents are proportional to the square roots of electric field amplitudes. Nonlinear currents generated by the trapped <span class="hlt">electrons</span> are studied to obtain analytical representations of the growth rates and frequency spreads. Numerical examples are presented to illustrate our theoretical analysis.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2009A%26A...502..341W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009A%26A...502..341W"><span><span class="hlt">Electron</span> acceleration in the turbulent reconnecting current <span class="hlt">sheets</span> in solar flares</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Wu, G. P.; Huang, G. L.</p> <p>2009-07-01</p> <p>Context: We investigate the nonlinear evolution of the <span class="hlt">electron</span> distribution in the presence of the strong inductive electric field in the reconnecting current <span class="hlt">sheets</span> (RCS) of solar flares. Aims: We aim to study the characteristics of nonthermal <span class="hlt">electron</span>-beam <span class="hlt">plasma</span> instability and its influence on <span class="hlt">electron</span> acceleration in RCS. Methods: Including the external inductive field, the one-dimensional Vlasov simulation is performed with a realistic mass ratio for the first time. Results: Our principal findings are as follows: 1) the Buneman instability can be quickly excited on the timescale of 10-7 s for the typical parameters of solar flares. After saturation, the beam-<span class="hlt">plasma</span> instabilities are excited due to the non-Maxwellian <span class="hlt">electron</span> distribution; 2) the final velocity of the <span class="hlt">electrons</span> trapped by these waves is of the same order as the phase speed of the waves, while the untrapped <span class="hlt">electrons</span> continue to be accelerated; 3) the inferred anomalous resistance of the current <span class="hlt">sheet</span> and the energy conversion rate are basically of the same order as those previously estimated, e.g., “the analysis of Martens”. Conclusions: The Buneman instability is excited on the timescale of 10-7 s and the wave-particle resonant interaction limits the low-energy <span class="hlt">electrons</span> to be further accelerated in RCS.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/6468214','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/6468214"><span>Structure of the <span class="hlt">plasma</span> <span class="hlt">sheet</span>-lobe boundary in the earth's magnetotail</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Orsini, S.; Candidi, M.; Formisano, V.; Balsiger, H.; Ghielmetti, A.; Ogilvie, K.W.</p> <p>1984-03-01</p> <p>The structure of the magnetotail <span class="hlt">plasma</span> <span class="hlt">sheet-plasma</span> lobe boundary is studied by observing the properties of tailward flowing O/sup +/ ion streams. These have been detected by the ISEE 2 <span class="hlt">plasma</span> experiment inside the boundary during three time periods in April 1978: data from the ISEE 1 <span class="hlt">electron</span> spectrometer are used to define the location of the boundary. The density of the O/sup +/ ion streams has a relative maximum, and their velocity has a relative minimum at the boundary. The xy drift velocity component across the local magnetic field reverses at the boundary, indicating a reversal of the E/sub z/ electric field component. These changes are consistent with the topology of the electric field lines in the tail as mapped from the ionosphere.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/24266197','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/24266197"><span><span class="hlt">Plasma</span> treatment of thin film coated with graphene flakes for the reduction of <span class="hlt">sheet</span> resistance.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Kim, Sung Hee; Oh, Jong Sik; Kim, Kyong Nam; Seo, Jin Seok; Jeon, Min Hwan; Yang, Kyung Chae; Yeom, Geun Young</p> <p>2013-12-01</p> <p>We investigated the effects of <span class="hlt">plasma</span> treatment on the <span class="hlt">sheet</span> resistance of thin films spray-coated with graphene flakes on polyethylene terephthalate (PET) substrates. Thin films coated with graphene flakes show high <span class="hlt">sheet</span> resistance due to defects within graphene edges, domains, and residual oxygen content. Cl2 <span class="hlt">plasma</span> treatment led to decreased <span class="hlt">sheet</span> resistance when treatment time was increased, but when thin films were treated for too long the <span class="hlt">sheet</span> resistance increased again. Optimum treatment time was related to film thickness. The reduction of <span class="hlt">sheet</span> resistance may be explained by the donation of holes due to forming pi-type covalent bonds of Cl with carbon atoms on graphene surfaces, or by C--Cl bonding at the sites of graphene defects. However, due to radiation damage caused by <span class="hlt">plasma</span> treatment, <span class="hlt">sheet</span> resistance increased with increased treatment time. We found that the <span class="hlt">sheet</span> resistance of PET film coated with graphene flakes could be decreased by 50% under optimum conditions.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/6200419','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/6200419"><span>Superposed epoch analysis of pressure and magnetic field configuration changes in the <span class="hlt">plasma</span> <span class="hlt">sheet</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Kistler, L.M.; Moebius, E. ); Baumjohann, W. ); Nagai, T. )</p> <p>1993-06-01</p> <p>The authors report on an analysis of pressure and magnetic configuration within the <span class="hlt">plasma</span> <span class="hlt">sheet</span> following the initiation of substorm events. They have constructed this time dependent picture by using an epoch analysis of data from the AMPTE/IRM spacecraft. This analysis procedure can be used to construct a unified picture of events, provided they are reproducible, from a statistical analysis of a series of point measurements. The authors first determine the time dependent pressure changes in the <span class="hlt">plasma</span> <span class="hlt">sheet</span>. With some simplifying assumptions they then determine the z dependence of the pressure profiles, and from this distribution determine how field lines in the <span class="hlt">plasma</span> <span class="hlt">sheet</span> map to the neutral <span class="hlt">sheet</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015AdSpR..56.1194C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015AdSpR..56.1194C"><span>Preliminary empirical model of inner boundary of ion <span class="hlt">plasma</span> <span class="hlt">sheet</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Cao, J. B.; Zhang, D.; Reme, H.; Dandouras, I.; Sauvaud, J. A.; Fu, H. S.; Wei, X. H.</p> <p>2015-09-01</p> <p>The penetration of the <span class="hlt">plasma</span> <span class="hlt">sheet</span> into the inner magnetosphere is important to both ring current formation and spacecraft charging at geosynchronous orbit. This paper, using hot ion data recorded by HIA of TC-1/DSP, establishes an empirical model of the inner boundary of ion <span class="hlt">plasma</span> <span class="hlt">sheet</span> (IBIPS) on the near equatorial plane. All IBIPS are located inside geocentric radial distance of 9 RE. We divided local times (LT) into eight local time bins and found that during quiet times (Kp ⩽ 2-), the IBIPS is closest to the Earth on the pre-midnight side (LT = 1930-2130) and farthest on the dawn side (LT = 0430-0730), which differs from previous spiral models. The geocentric radius of IBIPS in each local time bin can be described by a linear fitting function: Rps = A + Bkp · Kp. The changing rate Bkp of the radius of IBIPS relative to Kp index on the midnight side (LT = 2230-0130) and post-night side (LT = 0130-0430) are the two largest (0.66 and 0.67), indicating that the IBIPS on the night side (LT = 2230-0430) moves fastest when Kp changes. Since the IBIPSs in different local times bins have different changing rates, both the size and shape of IBIPS change when Kp varies. The correlation coefficients between the radius of IBIPS and the instantaneous Kp increase with the increase of ΔT (the time difference between IBIPS crossing time and preceding Kp interval), which suggests that with the increase of ΔT, the radius of IBIPS is more and more controlled by instantaneous Kp, and the influence of preceding Kp becomes weaker. The response time of IBIPS to Kp is between 80 and 95 min. When ΔT > 95 min, the correlation coefficient basically keeps unchanged and only has a weak increase, suggesting that the IBIPS is mainly determined by the convection electric field represented by instantaneous Kp.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/22493753','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/22493753"><span>Current <span class="hlt">sheets</span> with inhomogeneous <span class="hlt">plasma</span> temperature: Effects of polarization electric field and 2D solutions</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Catapano, F. Zimbardo, G.; Artemyev, A. V. Vasko, I. Y.</p> <p>2015-09-15</p> <p>We develop current <span class="hlt">sheet</span> models which allow to regulate the level of <span class="hlt">plasma</span> temperature and density inhomogeneities across the <span class="hlt">sheet</span>. These models generalize the classical Harris model via including two current-carrying <span class="hlt">plasma</span> populations with different temperature and the background <span class="hlt">plasma</span> not contributing to the current density. The parameters of these <span class="hlt">plasma</span> populations allow regulating contributions of <span class="hlt">plasma</span> density and temperature to the pressure balance. A brief comparison with spacecraft observations demonstrates the model applicability for describing the Earth magnetotail current <span class="hlt">sheet</span>. We also develop a two dimensional (2D) generalization of the proposed model. The interesting effect found for 2D models is the nonmonotonous profile (along the current <span class="hlt">sheet</span>) of the magnetic field component perpendicular to the current <span class="hlt">sheet</span>. Possible applications of the model are discussed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/25186188','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/25186188"><span>Combination of platelet-rich <span class="hlt">plasma</span> within periodontal ligament stem cell <span class="hlt">sheets</span> enhances cell differentiation and matrix production.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Xu, Qiu; Li, Bei; Yuan, Lin; Dong, Zhiwei; Zhang, Hao; Wang, Han; Sun, Jin; Ge, Song; Jin, Yan</p> <p>2017-03-01</p> <p>The longstanding goal of periodontal therapy is to regenerate periodontal tissues. Although platelet-rich <span class="hlt">plasma</span> (PRP) has been gaining increasing popularity for use in the orofacial region, whether PRP is useful for periodontal regeneration is still unknown. The purpose of this study was to determine whether a mixture of periodontal ligament stem cell (PDLSC) <span class="hlt">sheets</span> and PRP promoted bone regeneration, one of the most important measurement indices of periodontal tissue regenerative capability in vitro and in vivo. In this study, we evaluated the effects of different doses of PRP on the differentiation of human PDLSCs. Then cell <span class="hlt">sheet</span> formation, extracellular matrix deposition and osteogenic gene expression in response to different doses of PRP treatment during <span class="hlt">sheet</span> grafting was investigated. Furthermore, we implanted PDLSC <span class="hlt">sheets</span> treated with 1% PRP subcutaneously into immunocompromised mice to evaluate their bone-regenerative capability. The results revealed that 1% PRP significantly enhanced the osteogenic differentiation of PDLSCs. Based on the production of extracellular matrix proteins, the results of scanning <span class="hlt">electron</span> microscopy and the expression of the osteogenic genes ALP, Runx2, Col-1 and OCN, the provision of 1% PRP for PDLSC <span class="hlt">sheets</span> was the most effective PRP administration mode for cell <span class="hlt">sheet</span> formation. The results of in vivo transplantation showed that 1% PRP-mediated PDLSC <span class="hlt">sheets</span> exhibited better periodontal tissue regenerative capability than those obtained without PRP intervention. These data suggest that a suitable concentration of PRP stimulation may enhance extracellular matrix production and positively affect cell behaviour in PDLSC <span class="hlt">sheets</span>. Copyright © 2014 John Wiley & Sons, Ltd.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/22047453','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/22047453"><span>Energy efficiency of <span class="hlt">electron</span> <span class="hlt">plasma</span> emitters</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Zalesski, V. G.</p> <p>2011-12-15</p> <p><span class="hlt">Electron</span> emission influence from gas-discharge <span class="hlt">plasma</span> on <span class="hlt">plasma</span> emitter energy parameters is considered. It is shown, that <span class="hlt">electron</span> emission from <span class="hlt">plasma</span> is accompanied by energy contribution redistribution in the gas-discharge from <span class="hlt">plasma</span> emitter supplies sources-the gas-discharge power supply and the accelerating voltage power supply. Some modes of <span class="hlt">electron</span> emission as a result can be realized: 'a probe measurements mode,' 'a transitive mode,' and 'a full switching mode.'.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2009JGRA..114.6214H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009JGRA..114.6214H"><span>Poleward arcs of the auroral oval during substorms and the inner edge of the <span class="hlt">plasma</span> <span class="hlt">sheet</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Haerendel, Gerhard</p> <p>2009-06-01</p> <p>An analytical model for the connection between the near-Earth edge of the <span class="hlt">plasma</span> <span class="hlt">sheet</span> at substorm onset and the auroral arcs at the poleward edge of the auroral oval is presented. The connection is established through the existence of a Boström type I current system. Its generator is assumed to be constituted by a narrow high-beta <span class="hlt">plasma</span> layer located at the interface between the near-Earth <span class="hlt">plasma</span> <span class="hlt">sheet</span> and the outer edge of the near-dipolar field of the magnetosphere. The energy balance between the downward Poynting flux and the energy conversion in the auroral acceleration region and ionosphere provides a relation for the electric fields as a function of the upward field-aligned current. Only the upward current region is being considered in this work. An interesting effect, incorporated in the energy balance, is the feedback of the auroral electrojet on the magnetospheric <span class="hlt">plasma</span> by dragging the latter eastward from below under the action of a Hall generator. Thereby a relation arises between the westward electric field, tangential to the arc, and the equatorward polarization field. Quantitative solution of the energy equation is achieved by using the empirical relations between auroral energy flux and <span class="hlt">electron</span> energy and the integrated Hall and Pedersen conductivities. Accommodation of the downward energy flux requires the existence of a minimum arc length. The resulting quantities are consistent with typical auroral data sets. Relating the downward energy flux to the parameters of the generator reveals a strong dependence of polarization electric field, overall energy dissipation, and total current strength on the <span class="hlt">plasma</span> beta of the generator. The dumping of excess energy from the high-beta <span class="hlt">plasma</span> layer into the auroral arc(s) allows the stretched tail field lines to transform into dipolar field lines. It opens, so-to-speak, the gate into the outer magnetosphere.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19920050936&hterms=IRM&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3DIRM','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19920050936&hterms=IRM&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3DIRM"><span>Bursty bulk flows in the inner central <span class="hlt">plasma</span> <span class="hlt">sheet</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Angelopoulos, V.; Baumjohann, W.; Kennel, C. F.; Coronti, F. V.; Kivelson, M. G.; Pellat, R.; Walker, R. J.; Luehr, H.; Paschmann, G.</p> <p>1992-01-01</p> <p>High-speed flows in the inner central <span class="hlt">plasma</span> <span class="hlt">sheet</span> (first reported by Baumjohann et al. (1990) are studied, together with the concurrent behavior of the <span class="hlt">plasma</span> and magnetic field, by using AMPTE/IRM data from about 9 to 19 R(E) in the earth magnetotail. The conclusions drawn from the detailed analysis of a representative event are reinforced by a superposed epoch analysis applied on two years of data. The high-speed flows organize themselves in 10-min time scale flow enhancements called here bursty-bulk flow (BBF) events. Both temporal and spatial effects are responsible for their bursty nature. The flow velocity exhibits peaks of very large amplitude with a characteristic time scale of the order of a minute, which are usually associated with magnetic field dipolarizations and ion temeperature increases. The BBFs represent intervals of enhanced earthward convection and energy transport per unit area in the y-z GSM direction of the order of 5 x 10 exp 19 ergs/R(E-squared).</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2011APS..DPPCP9026S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011APS..DPPCP9026S"><span>Communication through a <span class="hlt">plasma</span> <span class="hlt">sheet</span> around a fast moving vehicle</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Sotnikov, V. I.; Mudaliar, S.; Genoni, T.; Rose, D.; Oliver, B. V.; Mehlhorn, T. A.</p> <p>2011-10-01</p> <p>Investigation of the complicated problem of scattering of electromagnetic waves on turbulent pulsations induced by a sheared flow inside a <span class="hlt">plasma</span> sheath is important for many applications including communication with hypersonic and re-entry vehicles. Theoretical and computational work aimed at improving the understanding of electromagnetic wave scattering processes in such turbulent <span class="hlt">plasmas</span> is presented. We analyze excitation of low frequency ion-acoustic type oscillations in a compressible <span class="hlt">plasma</span> flow with flow velocity shear and influence of such turbulent pulsations on scattering of high frequency electromagnetic waves used for communication purposes. We have appropriately included in our analysis the presence of <span class="hlt">electron</span> and ion collisions with neutrals as well as <span class="hlt">electron</span> - ion collisions. Results of numerical solutions for <span class="hlt">plasma</span> density and electric field perturbations for different velocity profiles have been used in the derived expressions for scattered wave energy and scattering cross section. Work supported by the Air Force Research Laboratory and Air Force Office Of Scientific Research Sandia is a multiprogram laboratory operated by Sandia Corporation, A Lockheed Martin Company, under contract DE-AC04-94AL85000.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19940025621','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19940025621"><span>A study of the formation and dynamics of the Earth's <span class="hlt">plasma</span> <span class="hlt">sheet</span> using ion composition data</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Lennartsson, O. W.</p> <p>1994-01-01</p> <p>Over two years of data from the Lockheed <span class="hlt">Plasma</span> Composition Experiment on the ISEE 1 spacecraft, covering ion energies between 100 eV/e and about 16 keV/e, have been analyzed in an attempt to extract new information about three geophysical issues: (1) solar wind penetration of the Earth's magnetic tail; (2) relationship between <span class="hlt">plasma</span> <span class="hlt">sheet</span> and tail lobe ion composition; and (3) possible effects of heavy terrestrial ions on <span class="hlt">plasma</span> <span class="hlt">sheet</span> stability.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19860061853&hterms=central+heating&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3Dcentral%2Bheating','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19860061853&hterms=central+heating&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3Dcentral%2Bheating"><span>A statistical study of the central <span class="hlt">plasma</span> <span class="hlt">sheet</span> - Implications for substorm models</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Huang, C. Y.; Frank, L. A.</p> <p>1986-01-01</p> <p>The University of Iowa Lepedea on board ISEE 1 is used to investigate the characteristics of the central <span class="hlt">plasma</span> <span class="hlt">sheet</span> under all levels of geomagnetic activity. Positive ion responses from 1 eV to 45 keV are used in this study. All the periods during 1978 when the central <span class="hlt">plasma</span> <span class="hlt">sheet</span> is encountered are included. This study excludes all boundary layer samples. The results of this study show that the central <span class="hlt">plasma</span> <span class="hlt">sheet</span> consists of <span class="hlt">plasma</span> with high thermal energy (several keV) but low bulk speeds. This remains true even during high geomagnetic activity. The main effect of increasing activity is heating of the <span class="hlt">plasma</span> <span class="hlt">sheet</span>, preferentially at the high-latitude boundaries.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19830061985&hterms=plasma+explained&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3Dplasma%2Bexplained','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19830061985&hterms=plasma+explained&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3Dplasma%2Bexplained"><span>New observations of <span class="hlt">plasma</span> vortices and insights into their interpretation. [in magnetotail <span class="hlt">plasma</span> <span class="hlt">sheet</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Hones, E. W., Jr.; Birn, J.; Bame, S. J.; Russell, C. T.</p> <p>1983-01-01</p> <p>Two- and three-dimensional <span class="hlt">plasma</span> measurements and three-dimensional magnetic field measurements made with the ISEE 1 and 2 satellites during sixteen <span class="hlt">plasma</span> vortex occurrences in the magnetotail <span class="hlt">plasma</span> <span class="hlt">sheet</span> are used to develop a fuller description of the vortex phenomenon than has existed heretofore. The phase and energy propagation properties of the vortex waves was studied in particular. The rotation period of the vortices (T = 10 + or - 5 minutes) is apparently independent of location, while the wavelength (lambda not less than several Re) increases with increasing distance down the tail, pointing to a global mode of propagation in which effects of inhomogeneous equilibrium are important. The flow rotation can be explained by propagation of surface waves or resonant waves in a uniform medium. Other observed features, however, require a nonuniform model: nonuniform propagation properties and differences of the phase propagation speed calculated from different components of velocity or magnetic field.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_5");'>5</a></li> <li><a href="#" onclick='return showDiv("page_6");'>6</a></li> <li class="active"><span>7</span></li> <li><a href="#" onclick='return showDiv("page_8");'>8</a></li> <li><a href="#" onclick='return showDiv("page_9");'>9</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_7 --> <div id="page_8" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_6");'>6</a></li> <li><a href="#" onclick='return showDiv("page_7");'>7</a></li> <li class="active"><span>8</span></li> <li><a href="#" onclick='return showDiv("page_9");'>9</a></li> <li><a href="#" onclick='return showDiv("page_10");'>10</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="141"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/10146831','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/10146831"><span>Poleward leaping auroras, the substorm expansive and recovery phases and the recovery of the <span class="hlt">plasma</span> <span class="hlt">sheet</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Hones, E.W.</p> <p>1992-05-01</p> <p>The auroral motions and geomagnetic changes the characterize the substorm`s expansive phase, maximum epoch, and recovery phase are discussed in the context of their possible associations with the dropout and, especially, the recovery of the magnetotail <span class="hlt">plasma</span> <span class="hlt">sheet</span>. The evidence that there may be an inordinately sudden large poleward excursion or displacement (a poleward leap) of the electrojet and the auroras at the expansive phase-recovery phase transition is described. The close temporal association of these signatures with the recovery of the <span class="hlt">plasma</span> <span class="hlt">sheet</span>, observed on many occasions, suggests a causal relationship between substorm maximum epoch and recovery phase on the one hand and <span class="hlt">plasma</span> <span class="hlt">sheet</span> recovery on the other.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/5370328','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/5370328"><span>Poleward leaping auroras, the substorm expansive and recovery phases and the recovery of the <span class="hlt">plasma</span> <span class="hlt">sheet</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Hones, E.W.</p> <p>1992-01-01</p> <p>The auroral motions and geomagnetic changes the characterize the substorm's expansive phase, maximum epoch, and recovery phase are discussed in the context of their possible associations with the dropout and, especially, the recovery of the magnetotail <span class="hlt">plasma</span> <span class="hlt">sheet</span>. The evidence that there may be an inordinately sudden large poleward excursion or displacement (a poleward leap) of the electrojet and the auroras at the expansive phase-recovery phase transition is described. The close temporal association of these signatures with the recovery of the <span class="hlt">plasma</span> <span class="hlt">sheet</span>, observed on many occasions, suggests a causal relationship between substorm maximum epoch and recovery phase on the one hand and <span class="hlt">plasma</span> <span class="hlt">sheet</span> recovery on the other.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015AGUFMSM13D2545B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015AGUFMSM13D2545B"><span>Ion Beams in the <span class="hlt">Plasma</span> <span class="hlt">Sheet</span> Boundary Layer</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Birn, J.; Hesse, M.; Runov, A.; Zhou, X.</p> <p>2015-12-01</p> <p>We explore characteristics of energetic particles in the <span class="hlt">plasma</span> <span class="hlt">sheet</span> boundary layer associated with dipolarization events, based on simulations and observations. The simulations use the electromagnetic fields of an MHD simulation of magnetotail reconnection and flow bursts as basis for test particle tracing. They are complemented by self-consistent fully electrodynamic particle-in-cell (PIC) simulations. The test particle simulations confirm that crescent shaped earthward flowing ion velocity distributions with strong perpendicular anisotropy can be generated as a consequence of near tail reconnection, associated with earthward flows and propagating magnetic field dipolarization fronts. Both PIC and test particle simulations show that the ion distribution in the outflow region close to the reconnection site also consist of a beam superposed on an undisturbed population; this beam, however, does not show strong perpendicular anisotropy. This suggests that the crescent shape is created by quasi-adiabatic deformation from ion motion along the magnetic field toward higher field strength. The simulation results compare favorably with ``Time History of Events and Macroscale Interactions during Substorms" (THEMIS) observations.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016EGUGA..1814264D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016EGUGA..1814264D"><span>Ion flow ripples in the Earth's <span class="hlt">plasma</span> <span class="hlt">sheet</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>De Spiegeleer, Alexandre; Hamrin, Maria; Pitkänen, Timo; Norqvist, Patrik; Mann, Ingrid</p> <p>2016-04-01</p> <p>For a long time, magnetotail flows were considered rather smooth and laminar, and primarily dominated by a simple convection flow pattern. However, in the early 90's, high speed bursty bulk flows (BBFs) were discovered and found to commonly perturb the underlying convection flows. In addition, there are other disturbances complicating the magnetotail flow pattern. Instabilities such as the Kelvin-Helmholz instability and the kink instability can cause different types of magnetic field oscillations, such as field line resonances. It is expected that ions will follow these oscillations if the typical time and length scales are larger than the gyroperiod and gyroradius of the ions. Though low-velocity sloshing and ripple disturbances of the average magnetotail convection flows have been observed, their connection with magnetic field oscillations is not fully understood. Furthermore, when studying BFFs, these "Ion Flow Ripples" (IFRs) are often neglected, dismissed as noise or can even erroneously be identified as BBFs. It is therefore of utter importance to find out and understand the role of IFRs in magnetotail dynamics. In a statistical investigation, we use several years of Cluster <span class="hlt">plasma</span> <span class="hlt">sheet</span> data to study the low-speed flows in the magnetotail. We investigate different types of IFRs, study their occurrence, and discuss their possible causes.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016cosp...41E.624F','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016cosp...41E.624F"><span>Destabilization of 2D magnetic current <span class="hlt">sheets</span> by resonance with bouncing <span class="hlt">electron</span> - a new theory</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Fruit, Gabriel; Louarn, Philippe; Tur, Anatoly</p> <p>2016-07-01</p> <p>In the general context of understanding the possible destabilization of the magnetotail before a substorm, we propose a kinetic model for electromagnetic instabilities in resonant interaction with trapped bouncing <span class="hlt">electrons</span>. The geometry is clearly 2D and uses Harris <span class="hlt">sheet</span> profile. Fruit et al. 2013 already used this model to investigate the possibilities of electrostatic instabilities. Tur et al. 2014 generalizes the model for full electromagnetic perturbations. Starting with a modified Harris <span class="hlt">sheet</span> as equilibrium state, the linearized gyrokinetic Vlasov equation is solved for electromagnetic fluctuations with period of the order of the <span class="hlt">electron</span> bounce period (a few seconds). The particle motion is restricted to its first Fourier component along the magnetic field and this allows the complete time integration of the non local perturbed distribution functions. The dispersion relation for electromagnetic modes is finally obtained through the quasi neutrality condition and the Ampere's law for the current density. The present talk will focus on the main results of this theory. The electrostatic version of the model may be applied to the near-Earth environment (8-12 R_{E}) where beta is rather low. It is showed that inclusion of bouncing <span class="hlt">electron</span> motion may enhance strongly the growth rate of the classical drift wave instability. This model could thus explain the generation of strong parallel electric fields in the ionosphere and the formation of aurora beads with wavelength of a few hundreds of km. In the electromagnetic version, it is found that for mildly stretched current <span class="hlt">sheet</span> (B_{z} > 0.1 B _{lobes}) undamped modes oscillate at typical <span class="hlt">electron</span> bounce frequency with wavelength of the order of the <span class="hlt">plasma</span> <span class="hlt">sheet</span> thickness. As the stretching of the <span class="hlt">plasma</span> <span class="hlt">sheet</span> becomes more intense, the frequency of these normal modes decreases and beyond a certain threshold in B_{z}/B _{lobes}, the mode becomes explosive (pure imaginary frequency) with typical growing rate of a few</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1997AnGeo..15.1246S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1997AnGeo..15.1246S"><span>Spatial structure of the <span class="hlt">plasma</span> <span class="hlt">sheet</span> boundary layer at distances greater than 180 R E as derived from energetic particle measurements on GEOTAIL</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Sarafopoulos, D. V.; Sarris, E. T.; Angelopoulos, V.; Yamamoto, T.; Kokubun, S.</p> <p>1997-10-01</p> <p>We have analyzed the onsets of energetic particle bursts detected by the ICS and STICS sensors of the EPIC instrument on board the GEOTAIL spacecraft in the deep magnetotail (i.e., at distances greater than 180 RE). Such bursts are commonly observed at the <span class="hlt">plasma-sheet</span> boundary layer (PSBL) and are highly collimated along the magnetic field. The bursts display a normal velocity dispersion (i.e., the higher-speed particles are seen first, while the progressively lower speed particles are seen later) when observed upon entry of the spacecraft from the magnetotail lobes into the <span class="hlt">plasma</span> <span class="hlt">sheet</span>. Upon exit from the <span class="hlt">plasma</span> <span class="hlt">sheet</span> a reverse velocity dispersion is observed (i.e., lower-speed particles disappear first and higher-speed particles disappear last). Three major findings are as follows. First, the tailward-jetting energetic particle populations of the distant-tail <span class="hlt">plasma</span> <span class="hlt">sheet</span> display an energy layering: the energetic <span class="hlt">electrons</span> stream along open PSBL field lines with peak fluxes at the lobes. Energetic protons occupy the next layer, and as the spacecraft moves towards the neutral <span class="hlt">sheet</span> progressively decreasing energies are encountered systematically. These <span class="hlt">plasma-sheet</span> layers display spatial symmetry, with the plane of symmetry the neutral <span class="hlt">sheet</span>. Second, if we consider the same energy level of energetic particles, then the H+ layer is confined within that of the energetic <span class="hlt">electron</span>, the He++ layer is confined within that of the proton, and the oxygen layer is confined within the alpha particle layer. Third, whenever the energetic <span class="hlt">electrons</span> show higher fluxes inside the <span class="hlt">plasma</span> <span class="hlt">sheet</span> as compared to those at the boundary layer, their angular distribution is isotropic irrespective of the Earthward or tailward character of fluxes, suggesting a closed field line topology.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016EPJWC.13203020K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016EPJWC.13203020K"><span><span class="hlt">Plasma</span> heating and acceleration in current <span class="hlt">sheets</span> formed in discharges in argon</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kyrie, N. P.</p> <p>2016-12-01</p> <p>According to present notion, flares on the sun and other stars, substorms in magnetospheres of Earth and other planets, and disruptive instabilities in tokamak <span class="hlt">plasma</span> are connected to development of current <span class="hlt">sheets</span> in magnetized <span class="hlt">plasma</span>. Therefore, current <span class="hlt">sheet</span> dynamics and magnetic reconnection processes were studied actively during the last several decades. This paper presents the results of experimental studies of <span class="hlt">plasma</span> heating and acceleration in current <span class="hlt">sheets</span> formed in discharges in argon. The temperature and energy of directed motion of argon ions of different degrees of ionization were measured by spectroscopic methods. It was found that Ar II, Ar III and Ar IV ions are localized in different regions of the <span class="hlt">sheet</span>. It was shown that Ampere forces applied to the <span class="hlt">sheet</span> can accelerate the argon ions to observed energies.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/23003270','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/23003270"><span>Plasmoid ejection and secondary current <span class="hlt">sheet</span> generation from magnetic reconnection in laser-<span class="hlt">plasma</span> interaction.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Dong, Quan-Li; Wang, Shou-Jun; Lu, Quan-Ming; Huang, Can; Yuan, Da-Wei; Liu, Xun; Lin, Xiao-Xuan; Li, Yu-Tong; Wei, Hui-Gang; Zhong, Jia-Yong; Shi, Jian-Rong; Jiang, Shao-En; Ding, Yong-Kun; Jiang, Bo-Bin; Du, Kai; He, Xian-Tu; Yu, M Y; Liu, C S; Wang, Shui; Tang, Yong-Jian; Zhu, Jian-Qiang; Zhao, Gang; Sheng, Zheng-Ming; Zhang, Jie</p> <p>2012-05-25</p> <p>Reconnection of the self-generated magnetic fields in laser-<span class="hlt">plasma</span> interaction was first investigated experimentally by Nilson et al. [Phys. Rev. Lett. 97, 255001 (2006)] by shining two laser pulses a distance apart on a solid target layer. An elongated current <span class="hlt">sheet</span> (CS) was observed in the <span class="hlt">plasma</span> between the two laser spots. In order to more closely model magnetotail reconnection, here two side-by-side thin target layers, instead of a single one, are used. It is found that at one end of the elongated CS a fanlike <span class="hlt">electron</span> outflow region including three well-collimated <span class="hlt">electron</span> jets appears. The (>1 MeV) tail of the jet energy distribution exhibits a power-law scaling. The enhanced <span class="hlt">electron</span> acceleration is attributed to the intense inductive electric field in the narrow <span class="hlt">electron</span> dominated reconnection region, as well as additional acceleration as they are trapped inside the rapidly moving plasmoid formed in and ejected from the CS. The ejection also induces a secondary CS.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2009AnGeo..27..745U','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009AnGeo..27..745U"><span>Collective dynamics of bursty particle precipitation initiating in the inner and outer <span class="hlt">plasma</span> <span class="hlt">sheet</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Uritsky, V. M.; Donovan, E.; Klimas, A. J.; Spanswick, E.</p> <p>2009-02-01</p> <p>Using multiscale spatiotemporal analysis of bursty precipitation events in the nighttime aurora as seen by the POLAR UVI instrument, we report a set of new statistical signatures of high- and low-latitude auroral activity, signaling a strongly non-uniform distribution of dissipation mechanism in the <span class="hlt">plasma</span> <span class="hlt">sheet</span>. We show that small-scale <span class="hlt">electron</span> emission events that initiate in the equatorward portion of the nighttime auroral oval (scaling mode A1) have systematically steeper power-law slopes of energy, power, area, and lifetime probability distributions compared to the events that initiate at higher latitudes (mode B). The low-latitude group of events also contain a small but energetically important subpopulation of substorm-scale disturbances (mode A2) described by anomalously low distribution exponents characteristic of barely stable thermodynamic systems that are prone to large-scale sporadic reorganization. The high latitude events (mode <I.B) can be accurately described by a single set of distributions exponents over the entire range of studied scales, with the exponent values consistent with globally stable self-organized critical (SOC) behavior. The low- and high latitude events have distinct inter-trigger time statistics, and are characterized by significantly different MLT distributions. Based on these results we conjecture that the inner and outer portions of the <span class="hlt">plasma</span> <span class="hlt">sheet</span> are associated with two (or more) mechanisms of collective dynamics that may represent an interplay between current disruption and magnetic reconnection scenarios of bursty energy conversion in the magnetotail.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1986JGR....91.4277S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1986JGR....91.4277S"><span>Energetic particle beams in the <span class="hlt">plasma</span> <span class="hlt">sheet</span> boundary layer following substorm expansion - Simultaneous near-earth and distant tail observations</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Scholer, M.; Baker, D. N.; Gloeckler, G.; Ipavich, F. M.; Galvin, A. B.; Klecker, B.; Terasawa, T.; Tsurutani, B. T.</p> <p>1986-04-01</p> <p>Simultaneous observations of ions and <span class="hlt">electron</span> beams in the near-earth and deep magnetotail following the onset of substorm are analyzed in terms of the substorm neutral line model. The observations were collected on March 20, 1983 with ISSE 1 and 3. Energy fluxes and intensity-time profiles of protons and <span class="hlt">electrons</span> are studied. The data reveal that the reconnection at the near-earth neutral line produces ions and <span class="hlt">electrons</span> for the <span class="hlt">plasma</span> <span class="hlt">sheet</span> boundary layer. The maximum electric potential along the neutral line is evaluated.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014APS..MARF29007L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014APS..MARF29007L"><span><span class="hlt">Electronic</span> transport in graphene <span class="hlt">sheets</span> in a random magnetic field</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Lewenkopf, Caio; Burgos, Rhonald; Warnes, Jesus; Lima, Leandro</p> <p>2014-03-01</p> <p>We present a theoretical study of the effect of ripples and strain fields in the transport properties of diffusive deposited graphene flakes. Defects in the crystalline structure, adsorbed atomic impurities and charge inhomogeneities at the substrate are believed to be the dominant disorder sources for the <span class="hlt">electronic</span> transport in graphene at low temperatures. We show that intrinsic ripples also effect the conductivity, in particular, its quantum corrections. To this end, we analyze recent experimental results on the conductivity of rippled monolayer graphene <span class="hlt">sheets</span> subjected to a strong magnetic field parallel to the graphene-substrate interface, B∥ [M. B. Lundeberg and J. A. Folk, Phys. Rev. Lett. 105, 146804 (2010)]. In this setting, B∥ gives rise to a random magnetic field normal to graphene <span class="hlt">sheet</span>, that depends on the local curvature of the smooth disordered ripples. The analysis of the weak localization corrections of the magnetoconductance allows to establish the dependence of <span class="hlt">electronic</span> dephasing rate on the magnitude of the random magnetic field. We compare the results for B∥ with the conductivity and weak localization corrections due to the pseudo-magnetic fields originated by intrinsic ripples and strain fields.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012EPJAP..6030401O','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012EPJAP..6030401O"><span>Controllable formation of graphene and graphene oxide <span class="hlt">sheets</span> using photo-catalytic reduction and oxygen <span class="hlt">plasma</span> treatment</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ostovari, Fatemeh; Abdi, Yaser; Ghasemi, Foad</p> <p>2012-12-01</p> <p>Au/SiO2/Si interdigital electrodes with thickness of 1 μm were created on silicon substrate. Graphene oxide (GO) <span class="hlt">sheets</span> hanging from these electrodes were obtained by spin coating of chemically synthesized GO dispersed in water. We used UV-light-induced photo-catalytic activity of titanium oxide nanoparticles to reduce the GO layer. Effects of the photo-induced chemical reduction on the conductivity of the GO were investigated. Also, low power DC <span class="hlt">plasma</span> was used for oxidation of the <span class="hlt">sheets</span>. Oxygen bombardment leads to <span class="hlt">sheets</span> with low electrical conductivity. Measurements show that graphene and GO <span class="hlt">sheets</span> with the controlled electrical conductivity were obtained by these processes. Scanning <span class="hlt">electron</span> and atomic force microscopy were used to study the morphology of the TiO2/GO and graphene structures. X-ray diffraction and Raman scattering analysis were used to verify the structural characteristics of the prepared <span class="hlt">sheets</span>. Analysis showed a gradual increase in the number of C-O bonds on the surface of the graphene layer as a result of increasing the time of <span class="hlt">plasma</span> bombardment. Based on the Raman spectroscopy, the photo-catalytic activity of TiO2 nanoparticles resulted in a decrease in the number of C-O bonds.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19920069701&hterms=current+sheet&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D80%26Ntt%3Dcurrent%2Bsheet','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19920069701&hterms=current+sheet&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D80%26Ntt%3Dcurrent%2Bsheet"><span>The thermal and <span class="hlt">plasma</span>-physical evolution of laminar current <span class="hlt">sheets</span> formed in the solar atmosphere by emerging flux</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Larosa, T. N.</p> <p>1992-01-01</p> <p>A time-dependent analysis of emerging flux is carried out, and the time evolution of both the current <span class="hlt">sheet</span> energetics and the <span class="hlt">plasma</span> state is calculated. This evolution is determined in two different regimes. In the first case the width of the current <span class="hlt">sheet</span> is assumed to be independent of the <span class="hlt">sheet</span> thermodynamics and is fixed by the initial conditions. In the second, the width of the current <span class="hlt">sheet</span> is a function of the resistivity and is allowed to decrease to its minimum given by the <span class="hlt">electron</span> gyroradius. In both cases the resistivity is computed according to the marginal stability hypothesis. In each case the thermodynamic evolution is found to be quite rapid, with the temperature increasing from 10,000 to 1,000,000 K in a second or less. In contrast to previous studies, it is found that the resistivity is not significantly enhanced by the current-driven <span class="hlt">plasma</span> wave turbulence. It is concluded that a laminar current <span class="hlt">sheet</span> cannot be responsible for the activity associated with emerging flux.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/22402426','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/22402426"><span><span class="hlt">Electronic</span>, phononic, and thermoelectric properties of graphyne <span class="hlt">sheets</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Sevinçli, Hâldun; Sevik, Cem</p> <p>2014-12-01</p> <p><span class="hlt">Electron</span>, phonon, and thermoelectric transport properties of α-, β-, γ-, and 6,6,12-graphyne <span class="hlt">sheets</span> are compared and contrasted with those of graphene. α-, β-, and 6,6,12-graphynes, with direction dependent Dirac dispersions, have higher <span class="hlt">electronic</span> transmittance than graphene. γ-graphyne also attains better electrical conduction than graphene except at its band gap. Vibrationally, graphene conducts heat much more efficiently than graphynes, a behavior beyond an atomic density differences explanation. Seebeck coefficients of the considered Dirac materials are similar but thermoelectric power factors decrease with increasing effective speeds of light. γ-graphyne yields the highest thermoelectric efficiency with a thermoelectric figure of merit as high as ZT = 0.45, almost an order of magnitude higher than that of graphene.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/603710','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/603710"><span><span class="hlt">Plasma</span> lenses for focusing relativistic <span class="hlt">electron</span> beams</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Govil, R.; Wheeler, S.; Leemans, W.</p> <p>1997-04-01</p> <p>The next generation of colliders require tightly focused beams with high luminosity. To focus charged particle beams for such applications, a <span class="hlt">plasma</span> focusing scheme has been proposed. <span class="hlt">Plasma</span> lenses can be overdense (<span class="hlt">plasma</span> density, n{sub p} much greater than <span class="hlt">electron</span> beam density, n{sub b}) or underdense (n{sub p} less than 2 n{sub b}). In overdense lenses the space-charge force of the <span class="hlt">electron</span> beam is canceled by the <span class="hlt">plasma</span> and the remaining magnetic force causes the <span class="hlt">electron</span> beam to self-pinch. The focusing gradient is nonlinear, resulting in spherical aberrations. In underdense lenses, the self-forces of the <span class="hlt">electron</span> beam cancel, allowing the <span class="hlt">plasma</span> ions to focus the beam. Although for a given beam density, a uniform underdense lens produces smaller focusing gradients than an overdense lens, it produces better beam quality since the focusing is done by <span class="hlt">plasma</span> ions. The underdense lens can be improved by tapering the density of the <span class="hlt">plasma</span> for optimal focusing. The underdense lens performance can be enhanced further by producing adiabatic <span class="hlt">plasma</span> lenses to avoid the Oide limit on spot size due to synchrotron radiation by the <span class="hlt">electron</span> beam. The <span class="hlt">plasma</span> lens experiment at the Beam Test Facility (BTF) is designed to study the properties of <span class="hlt">plasma</span> lenses in both overdense and underdense regimes. In particular, important issues such as <span class="hlt">electron</span> beam matching, time response of the lens, lens aberrations and shot-to-shot reproducibility are being investigated.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2003JGRA..108.1136T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2003JGRA..108.1136T"><span>Tail <span class="hlt">plasma</span> <span class="hlt">sheet</span> models derived from Geotail particle data</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Tsyganenko, N. A.; Mukai, T.</p> <p>2003-03-01</p> <p>Simple analytical models have been derived for the first time, describing the 2-D distribution (along and across the Earth's magnetotail) of the central <span class="hlt">plasma</span> <span class="hlt">sheet</span> (CPS) ion temperature, density, and pressure, as functions of the incoming solar wind and interplanetary magnetic field (IMF) parameters, at distances between 10 and 50 RE. The models are based on a large set of data of the Low-Energy Particle (LEP) and Magnetic Field (MGF) instruments, taken by Geotail spacecraft between 1994 and 1998, comprising 7234 1-min average values of the CPS temperature and density. Concurrent solar wind and IMF data were provided by the Wind and IMP 8 spacecraft. The accuracy of the models was gauged by the correlation coefficient (c.c.) R between the observed and predicted values of a parameter. The CPS ion density N is controlled mostly by the solar wind proton density and by the northward component of the IMF. Being the least stable characteristic of the CPS, it yielded the lowest c.c. RN = 0.57. The CPS temperature T, controlled mainly by the solar wind speed V and the IMF Bz, gave a higher c.c. RT = 0.71. The CPS ion pressure P was best controlled by the solar wind ram pressure Psw and by an IMF-related parameter F = B⟂?, where B⟂ is the perpendicular component of the IMF and θ is its clock angle. In a striking contrast with N and T, the model pressure P revealed a very high c.c. with the data, RP = 0.95, an apparent consequence of the force balance between the CPS and the tail lobe magnetic field. No significant dawn-dusk asymmetry of the CPS was found beyond the distance 10 RE, in line with the observed symmetry of the tail lobe magnetic field. The <span class="hlt">plasma</span> density N is lowest at midnight and increases toward the tail's flanks. Larger (smaller) solar wind ion densities and northward (southward) IMF Bz result in larger (smaller) N in the CPS. In contrast to the density N, the temperature T peaks at the midnight meridian and falls off toward the dawn/dusk flanks</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2004JGRA..10912202W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2004JGRA..10912202W"><span>Modeling the transition of the inner <span class="hlt">plasma</span> <span class="hlt">sheet</span> from weak to enhanced convection</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Wang, Chih-Ping; Lyons, Larry R.; Chen, Margaret W.; Toffoletto, Frank R.</p> <p>2004-12-01</p> <p>We seek to determine whether the adiabatic <span class="hlt">plasma</span> transport and energization resulting from electric and magnetic drift can quantitatively account for the <span class="hlt">plasma</span> <span class="hlt">sheet</span> under weak and enhanced convection observed by Geotail presented in the companion paper [, 2004]. We use a modified Magnetospheric Specification Model to simulate the dynamics and distributions of protons originating from the deep tail and low-latitude boundary layer (LLBL) under an assigned, slowly increasing convection electric field. The magnetic field is Tsyganenko 96 model, modified so that force balance is maintained along the midnight meridian. Our simulation results reproduce well the observed radial profiles and magnitudes of pressure and magnetic field. The changes of these parameters with convection strength are also well reproduced, indicating that the electric and magnetic drift control the large-scale structure of the <span class="hlt">plasma</span> <span class="hlt">sheet</span>. The <span class="hlt">plasma</span> flows near midnight are diverted toward dusk by diamagnetic drift. We obtain a steady state <span class="hlt">plasma</span> <span class="hlt">sheet</span> under strong and steady convection, showing that magnetic drift and field line stretching bring the <span class="hlt">plasma</span> <span class="hlt">sheet</span> away from possible convection disruption. The protons from the LLBL strongly affect the <span class="hlt">plasma</span> <span class="hlt">sheet</span> density and temperature during quiet times but not during enhanced convection. For the same cross-polar cap potential, stronger shielding of the convection electric field results in smaller energization. The penetration electric field is important in moving the <span class="hlt">plasma</span> <span class="hlt">sheet</span> to smaller geocentric radial distance. Our results suggest that the frozen-in condition E = -v × B is not valid in the inner <span class="hlt">plasma</span> <span class="hlt">sheet</span> because of strong diamagnetic drift.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/22407995','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/22407995"><span><span class="hlt">Electron</span> vortex magnetic holes: A nonlinear coherent <span class="hlt">plasma</span> structure</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Haynes, Christopher T. Burgess, David; Sundberg, Torbjorn; Camporeale, Enrico</p> <p>2015-01-15</p> <p>We report the properties of a novel type of sub-proton scale magnetic hole found in two dimensional particle-in-cell simulations of decaying turbulence with a guide field. The simulations were performed with a realistic value for ion to <span class="hlt">electron</span> mass ratio. These structures, <span class="hlt">electron</span> vortex magnetic holes (EVMHs), have circular cross-section. The magnetic field depression is associated with a diamagnetic azimuthal current provided by a population of trapped <span class="hlt">electrons</span> in petal-like orbits. The trapped <span class="hlt">electron</span> population provides a mean azimuthal velocity and since trapping preferentially selects high pitch angles, a perpendicular temperature anisotropy. The structures arise out of initial perturbations in the course of the turbulent evolution of the <span class="hlt">plasma</span>, and are stable over at least 100 <span class="hlt">electron</span> gyroperiods. We have verified the model for the EVMH by carrying out test particle and PIC simulations of isolated structures in a uniform <span class="hlt">plasma</span>. It is found that (quasi-)stable structures can be formed provided that there is some initial perpendicular temperature anisotropy at the structure location. The properties of these structures (scale size, trapped population, etc.) are able to explain the observed properties of magnetic holes in the terrestrial <span class="hlt">plasma</span> <span class="hlt">sheet</span>. EVMHs may also contribute to turbulence properties, such as intermittency, at short scale lengths in other astrophysical <span class="hlt">plasmas</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015PhPl...22a2309H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015PhPl...22a2309H"><span><span class="hlt">Electron</span> vortex magnetic holes: A nonlinear coherent <span class="hlt">plasma</span> structure</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Haynes, Christopher T.; Burgess, David; Camporeale, Enrico; Sundberg, Torbjorn</p> <p>2015-01-01</p> <p>We report the properties of a novel type of sub-proton scale magnetic hole found in two dimensional particle-in-cell simulations of decaying turbulence with a guide field. The simulations were performed with a realistic value for ion to <span class="hlt">electron</span> mass ratio. These structures, <span class="hlt">electron</span> vortex magnetic holes (EVMHs), have circular cross-section. The magnetic field depression is associated with a diamagnetic azimuthal current provided by a population of trapped <span class="hlt">electrons</span> in petal-like orbits. The trapped <span class="hlt">electron</span> population provides a mean azimuthal velocity and since trapping preferentially selects high pitch angles, a perpendicular temperature anisotropy. The structures arise out of initial perturbations in the course of the turbulent evolution of the <span class="hlt">plasma</span>, and are stable over at least 100 <span class="hlt">electron</span> gyroperiods. We have verified the model for the EVMH by carrying out test particle and PIC simulations of isolated structures in a uniform <span class="hlt">plasma</span>. It is found that (quasi-)stable structures can be formed provided that there is some initial perpendicular temperature anisotropy at the structure location. The properties of these structures (scale size, trapped population, etc.) are able to explain the observed properties of magnetic holes in the terrestrial <span class="hlt">plasma</span> <span class="hlt">sheet</span>. EVMHs may also contribute to turbulence properties, such as intermittency, at short scale lengths in other astrophysical <span class="hlt">plasmas</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016APS..DPPDI2003J','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016APS..DPPDI2003J"><span>Experimental Demonstration of Resistive <span class="hlt">Electron</span> Plasmoids in a Reconnecting Current <span class="hlt">Sheet</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Jara-Almonte, Jonathan</p> <p>2016-10-01</p> <p>Magnetic reconnection is an important process occurring in nearly all magnetized <span class="hlt">plasmas</span> that involves the complex coupling of multiple physical scales. Significant progress has been made in understanding the cross-scale physics of magnetic reconnection around localized reconnection sites, but how reconnection couples to global physics is still an open question. Recently, the spontaneous formation of plasmoids has been proposed as a mechanism for bridging widely disparate scales, thereby permitting fast reconnection in large systems. Numerous works have demonstrated the existence of collisionless plasmoids in both space and laboratory <span class="hlt">plasmas</span>, however to-date, direct evidence for collisional plasmoids has been confined to numerical simulations and analytic theory, although remote-sensing observations of solar and fusion <span class="hlt">plasmas</span> have provided some indirect evidence. However, it is known that many naturally occurring <span class="hlt">plasmas</span>, such as the solar chromosphere or the interstellar medium, are both large and collisional, thus requiring collisional plasmoids. In part, the current lack of experimental or in situ observational evidence for collisional plasmoids is due to the large Lundquist numbers required for plasmoid formation within the resistive MHD framework. In this work, experimental evidence for resistive <span class="hlt">electron</span> plasmoid formation during magnetic reconnection in the two-fluid regime is given. Using the Magnetic Reconnection Experiment (MRX), driven reconnection is studied in collisional current <span class="hlt">sheets</span> wherein the electric field is balanced solely by classical Spitzer resistivity. Despite low Lundquist numbers, these collisional current <span class="hlt">sheets</span> are observed to be unstable to the spontaneous formation of plasmoids, which is explained by the importance of <span class="hlt">electron</span> physics when in the two-fluid regime. The number of plasmoids is observed to scale with the Lundquist number. Due to the onset of plasmoids, both the local reconnection electric field and the globally</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_6");'>6</a></li> <li><a href="#" onclick='return showDiv("page_7");'>7</a></li> <li class="active"><span>8</span></li> <li><a href="#" onclick='return showDiv("page_9");'>9</a></li> <li><a href="#" onclick='return showDiv("page_10");'>10</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_8 --> <div id="page_9" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_7");'>7</a></li> <li><a href="#" onclick='return showDiv("page_8");'>8</a></li> <li class="active"><span>9</span></li> <li><a href="#" onclick='return showDiv("page_10");'>10</a></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="161"> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/6904217','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/6904217"><span>Experiments on a reflex-type <span class="hlt">sheet</span> <span class="hlt">plasma</span> negative-ion source</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Ando, A.; Kuroda, T.; Oka, Y.; Kaneko, O.; Karita, A.; Kawamoto, T. )</p> <p>1990-01-01</p> <p>Negative hydrogen ions are extracted from a reflex-type <span class="hlt">sheet</span> <span class="hlt">plasma</span>. <span class="hlt">Electron</span> density and temperature profiles are measured with changing the filling gas pressure, and they are optimized to the H{sup {minus}} production at the optimum gas pressure. The optimum gas pressure is 5 mTorr for the discharge current {ital I}{sub {ital d}} =2 A. As the discharge current {ital I}{sub {ital d}} increases, H{sup {minus}} current increases linearly corresponding to the density increase in the center region, but saturates above {ital I}{sub {ital d}} =40 A. The maximum extracted H{sup {minus}} current density of 4 mA/cm{sup 2} is obtained at {ital I}{sub {ital d}}=100 A.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19760008620&hterms=Auroras&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3DAuroras','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19760008620&hterms=Auroras&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3DAuroras"><span>ATS-5 observations of <span class="hlt">plasma</span> <span class="hlt">sheet</span> particles before the expansion-phase onset, appendix C.. [<span class="hlt">plasma</span>-particle interactions, magnetic storms and auroras</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Fujii, K.; Nishida, A.; Sharp, R. D.; Shelley, E. G.</p> <p>1975-01-01</p> <p>Behavior of the <span class="hlt">plasma</span> <span class="hlt">sheet</span> around its earthward edge during substorms was studied by using high resolution (every 2.6 sec) measurements of proton and <span class="hlt">electron</span> fluxes by ATS-5. In the injection region near midnight the flux increase at the expansion-phase onset is shown to lag behind the onset of the low-latitude positive bay by several minutes. Depending upon the case, before the above increase (1) the flux stays at a constant level, (2) it gradually increases for some tens of minutes, or (3) it briefly drops to a low level. Difference in the position of the satellite relative to the earthward edge and to the high-latitude boundary of the <span class="hlt">plasma</span> <span class="hlt">sheet</span> is suggested as a cause of the above difference in flux variations during the growth phase of substorms. Magnetograms and tables (data) are shown.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016cosp...41E.554E','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016cosp...41E.554E"><span>Role of magnetic field fluctuations in the Evolution of the kappa Distribution Functions in the <span class="hlt">Plasma</span> <span class="hlt">Sheet</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Espinoza, Cristobal; Antonova, Elizaveta; Stepanova, Marina; Valdivia, Juan Alejandro</p> <p>2016-07-01</p> <p>The evolution with the distance to Earth of ion and <span class="hlt">electron</span> distribution functions in the <span class="hlt">plasma</span> <span class="hlt">sheet</span>, approximated by kappa distributions, was studied by Stepanova and Antonova (2015, JGRA 120). Using THEMIS data for 5 events of satellite alignments along the tail, covering between 5 and 30 Earth radii, they found that the kappa parameter increases tailwards, for both ions and <span class="hlt">electrons</span>. In this work we analyse the magnetic fluctuations present in THEMIS data for the same 5 events. The aim is to explore the hypothesis proposed by Navarro et al. (2014, PRL 112), for solar wind <span class="hlt">plasmas</span>, that the observed magnetic fluctuations could be closely related to spontaneous fluctuations in the <span class="hlt">plasma</span>, if this can be described by stable distributions. Here we present our first results on the correlation between the spectral properties of the magnetic fluctuations and the observed parameters of the kappa distributions for different distances from Earth.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014AGUFMSM14B..04P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014AGUFMSM14B..04P"><span>MESSENGER Observation on Reconnection and Structure of Mercury's Magnetotail Lobes and <span class="hlt">Plasma</span> <span class="hlt">Sheet</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Poh, G. K.; Slavin, J. A.; Jia, X.; Raines, J. M.; Sun, W. J.; Gershman, D. J.; Anderson, B. J.</p> <p>2014-12-01</p> <p>Magnetic reconnection is known to be the most important process for <span class="hlt">plasma</span> transport and energy conversion in space <span class="hlt">plasma</span>. MESSENGER observations taken at Mercury have shown that magnetic reconnection is the dominant driver of magnetospheric dynamics and that it is significantly more intense than at Earth. Hence, Mercury provides a perfect natural laboratory to study the structure and reconnection at Mercury's magnetotail as signatures of magnetic reconnections are expected to be more intense and prominent as compared to Earth and the outer planets. Using 4 years of MESSENGER's magnetic field and <span class="hlt">plasma</span> data, we analyzed 356 <span class="hlt">plasma</span> <span class="hlt">sheet</span> crossings. We determined that the B-field magnitude in the magnetotail lobe and <span class="hlt">plasma</span> <span class="hlt">sheet</span> follows a power law relation as a function of downstream distance |XMSM|. Statistical studies on the direction of Bz in the <span class="hlt">plasma</span> <span class="hlt">sheet</span> suggest that reconnection X-lines are most likely to occur at distance |XMSM| < 2.5RM. Assuming simple pressure balance, we have estimated the <span class="hlt">plasma</span> beta β in the <span class="hlt">plasma</span> <span class="hlt">sheet</span> as a function of |XMSM|. Our results indicate that the beta is higher in the region where X-lines are usually found. Finally, we compared our results at Mercury with previous studies on the terrestrial magnetotail. Our results are consistent with the canonical idea that Mercury's magnetotail is structurally similar to Earth's but with shorter timescale due to more intense reconnection at Mercury.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1996PhPl....3.2041E','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1996PhPl....3.2041E"><span>Coupling between <span class="hlt">electron</span> <span class="hlt">plasma</span> waves in laser-<span class="hlt">plasma</span> interactions</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Everett, M. J.; Lal, A.; Clayton, C. E.; Mori, W. B.; Joshi, C.; Johnston, T. W.</p> <p>1996-05-01</p> <p>A Lagrangian fluid model (cold <span class="hlt">plasma</span>, fixed ions) is developed for analyzing the coupling between <span class="hlt">electron</span> <span class="hlt">plasma</span> waves. This model shows that a small wave number <span class="hlt">electron</span> <span class="hlt">plasma</span> wave (ω2,k2) will strongly affect a large wave number <span class="hlt">electron</span> <span class="hlt">plasma</span> wave (ω1,k1), transferring its energy into daughter waves or sidebands at (ω1+nω2,k1+nk2) in the lab frame. The accuracy of the model is checked via particle-in-cell simulations, which confirm that the energy in the mode at (ω1,k1) can be completely transferred to the sidebands at (ω1+nω2,k1+nk2) by the presence of the <span class="hlt">electron</span> <span class="hlt">plasma</span> mode at (ω2,k2). Conclusive experimental evidence for the generation of daughter waves via this coupling is then presented using time- and wave number-resolved spectra of the light from a probe laser coherently Thomson scattered by the <span class="hlt">electron</span> <span class="hlt">plasma</span> waves generated by the interaction of a two-frequency CO2 laser with a <span class="hlt">plasma</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/22258614','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/22258614"><span>Low <span class="hlt">sheet</span> resistance titanium nitride films by low-temperature <span class="hlt">plasma</span>-enhanced atomic layer deposition using design of experiments methodology</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Burke, Micheal Blake, Alan; Povey, Ian M.; Schmidt, Michael; Petkov, Nikolay; Carolan, Patrick; Quinn, Aidan J.</p> <p>2014-05-15</p> <p>A design of experiments methodology was used to optimize the <span class="hlt">sheet</span> resistance of titanium nitride (TiN) films produced by <span class="hlt">plasma</span>-enhanced atomic layer deposition (PE-ALD) using a tetrakis(dimethylamino)titanium precursor in a N{sub 2}/H{sub 2} <span class="hlt">plasma</span> at low temperature (250 °C). At fixed chamber pressure (300 mTorr) and <span class="hlt">plasma</span> power (300 W), the <span class="hlt">plasma</span> duration and N{sub 2} flow rate were the most significant factors. The lowest <span class="hlt">sheet</span> resistance values (163 Ω/sq. for a 20 nm TiN film) were obtained using <span class="hlt">plasma</span> durations ∼40 s, N{sub 2} flow rates >60 standard cubic centimeters per minute, and purge times ∼60 s. Time of flight secondary ion mass spectroscopy data revealed reduced levels of carbon contaminants in the TiN films with lowest <span class="hlt">sheet</span> resistance (163 Ω/sq.), compared to films with higher <span class="hlt">sheet</span> resistance (400–600 Ω/sq.) while transmission <span class="hlt">electron</span> microscopy data showed a higher density of nanocrystallites in the low-resistance films. Further significant reductions in <span class="hlt">sheet</span> resistance, from 163 Ω/sq. to 70 Ω/sq. for a 20 nm TiN film (corresponding resistivity ∼145 μΩ·cm), were achieved by addition of a postcycle Ar/N{sub 2} <span class="hlt">plasma</span> step in the PE-ALD process.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19860052873&hterms=ducting&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3Dducting','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19860052873&hterms=ducting&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3Dducting"><span>Dispersive ducting of MHD waves in the <span class="hlt">plasma</span> <span class="hlt">sheet</span> - A source of Pi2 wave bursts</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Edwin, P. M.; Roberts, B.; Hughes, W. J.</p> <p>1986-01-01</p> <p>Fast magnetoacoustic waves can be ducted by <span class="hlt">plasma</span> inhomogeneities such as the <span class="hlt">plasma</span> <span class="hlt">sheet</span>. As this ducting is dispersive an impulsive source will give rise to a well-defined, quasi-periodic wave packet with time-scales determined by the width of the inhomogeneity and characteristic speeds in the wave duct and surrounding medium. The duration of the wave packet depends upon the distance from the source. It is argued that an impulsive source in the <span class="hlt">plasma</span> <span class="hlt">sheet</span> at substorm onset will produce a wave packet near earth with characteristics similar to pi2 wave bursts and put this idea forward as a mechanism for the generation of pi2 pulsations.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19910026465&hterms=IRM&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3DIRM','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19910026465&hterms=IRM&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3DIRM"><span>The lobe to <span class="hlt">plasma</span> <span class="hlt">sheet</span> boundary layer transition - Theory and observations</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Schriver, D.; Ashour-Abdalla, M.; Treumann, R.; Nakamura, M.; Kistler, L. M.</p> <p>1990-01-01</p> <p>The lobe and the <span class="hlt">plasma</span> <span class="hlt">sheet</span> boundary layer in the earth's magnetotail are regions of different <span class="hlt">plasma</span> conditions and share a common interface. The transition from the lobe to the <span class="hlt">plasma</span> <span class="hlt">sheet</span> boundary layer is examined here using AMPTE/IRM data. When the satellite crossed from the lobe to the <span class="hlt">plasma</span> <span class="hlt">sheet</span> boundary layer, intense narrow-banded wave bursts at 1 kHz were observed and broadband electrostatic noise (BEN) immediately followed. Simultaneous with the onset of BEN, high energy earthward streaming proton beams at more than 40 keV (more than 2700 km/s) were detected. These results are used as input into a numerical simulation to study ion beam instabilities in the PSBL.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/1212467','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/1212467"><span>Shape of the terrestrial <span class="hlt">plasma</span> <span class="hlt">sheet</span> in the near-Earth magnetospheric tail as imaged by the Interstellar Boundary Explorer</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Dayeh, M. A.; Fuselier, S. A.; Funsten, H. O.; McComas, D. J.; Ogasawara, K.; Petrinec, S. M.; Schwadron, N. A.; Valek, P.</p> <p>2015-04-11</p> <p>We present remote, continuous observations from the Interstellar Boundary Explorer of the terrestrial <span class="hlt">plasma</span> <span class="hlt">sheet</span> location back to -16 Earth radii (R<sub>E</sub>) in the magnetospheric tail using energetic neutral atom emissions. The time period studied includes two orbits near the winter and summer solstices, thus associated with large negative and positive dipole tilt, respectively. Continuous side-view images reveal a complex shape that is dominated mainly by large-scale warping due to the diurnal motion of the dipole axis. Superposed on the global warped geometry are short-time fluctuations in <span class="hlt">plasma</span> <span class="hlt">sheet</span> location that appear to be consistent with <span class="hlt">plasma</span> <span class="hlt">sheet</span> flapping and possibly twisting due to changes in the interplanetary conditions. We conclude that the <span class="hlt">plasma</span> <span class="hlt">sheet</span> warping due to the diurnal motion dominates the average shape of the <span class="hlt">plasma</span> <span class="hlt">sheet</span>. Over short times, the position of the <span class="hlt">plasma</span> <span class="hlt">sheet</span> can be dominated by twisting and flapping.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/pages/biblio/1212467-shape-terrestrial-plasma-sheet-near-earth-magnetospheric-tail-imaged-interstellar-boundary-explorer','SCIGOV-DOEP'); return false;" href="https://www.osti.gov/pages/biblio/1212467-shape-terrestrial-plasma-sheet-near-earth-magnetospheric-tail-imaged-interstellar-boundary-explorer"><span>Shape of the terrestrial <span class="hlt">plasma</span> <span class="hlt">sheet</span> in the near-Earth magnetospheric tail as imaged by the Interstellar Boundary Explorer</span></a></p> <p><a target="_blank" href="http://www.osti.gov/pages">DOE PAGES</a></p> <p>Dayeh, M. A.; Fuselier, S. A.; Funsten, H. O.; ...</p> <p>2015-04-11</p> <p>We present remote, continuous observations from the Interstellar Boundary Explorer of the terrestrial <span class="hlt">plasma</span> <span class="hlt">sheet</span> location back to -16 Earth radii (RE) in the magnetospheric tail using energetic neutral atom emissions. The time period studied includes two orbits near the winter and summer solstices, thus associated with large negative and positive dipole tilt, respectively. Continuous side-view images reveal a complex shape that is dominated mainly by large-scale warping due to the diurnal motion of the dipole axis. Superposed on the global warped geometry are short-time fluctuations in <span class="hlt">plasma</span> <span class="hlt">sheet</span> location that appear to be consistent with <span class="hlt">plasma</span> <span class="hlt">sheet</span> flapping andmore » possibly twisting due to changes in the interplanetary conditions. We conclude that the <span class="hlt">plasma</span> <span class="hlt">sheet</span> warping due to the diurnal motion dominates the average shape of the <span class="hlt">plasma</span> <span class="hlt">sheet</span>. Over short times, the position of the <span class="hlt">plasma</span> <span class="hlt">sheet</span> can be dominated by twisting and flapping.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19890052819&hterms=contractor&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3Dcontractor','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19890052819&hterms=contractor&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3Dcontractor"><span>A model of <span class="hlt">electron</span> collecting <span class="hlt">plasma</span> contractors</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Davis, V. A.; Katz, I.; Mandell, M. J.; Parks, D. E.</p> <p>1989-01-01</p> <p>A model of <span class="hlt">plasma</span> contractors is being developed, which can be used to describe <span class="hlt">electron</span> collection in a laboratory test tank and in the space environment. To validate the model development, laboratory experiments are conducted in which the source <span class="hlt">plasma</span> is separated from the background <span class="hlt">plasma</span> by a double layer. Model calculations show that an increase in ionization rate with potential produces a steep rise in collected current with increasing potential.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19820051677&hterms=streaming&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D60%26Ntt%3Dstreaming','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19820051677&hterms=streaming&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D60%26Ntt%3Dstreaming"><span><span class="hlt">Plasma</span> behavior during energetic <span class="hlt">electron</span> streaming events further evidence for substorm-associated magnetic reconnection</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Bieber, J. W.; Stone, E. C.; Hones, E. W., Jr.; Baker, D. N.; Bame, S. J.</p> <p>1982-01-01</p> <p>A recent study showed that streaming energetic (more than 200 keV) <span class="hlt">electrons</span> in earth's magnetotail are statistically associated with southward magnetic fields and with enhancements of the AE index. It is shown here that the streaming <span class="hlt">electrons</span> characteristically are preceded by an approximately 15-minute period of tailward <span class="hlt">plasma</span> flow and followed by a dropout of the <span class="hlt">plasma</span> <span class="hlt">sheet</span>, thus demonstrating a clear statistical association between substorms and the classical signatures of magnetic reconnection and plasmoid formation. Additionally, a brief upward surge of mean <span class="hlt">electron</span> energy preceded <span class="hlt">plasma</span> dropout in several of the events studied, providing direct evidence of localized, reconnection-associated heating processes.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/27925736','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/27925736"><span><span class="hlt">Electron</span> Cooling in a Magnetically Expanding <span class="hlt">Plasma</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Little, J M; Choueiri, E Y</p> <p>2016-11-25</p> <p><span class="hlt">Electron</span> cooling in a magnetically expanding <span class="hlt">plasma</span>, which is a fundamental process for <span class="hlt">plasma</span> flow and detachment in magnetic nozzles, is experimentally investigated using a radio frequency <span class="hlt">plasma</span> source and magnetic nozzle (MN). Probe measurements of the <span class="hlt">plasma</span> density, potential, and <span class="hlt">electron</span> temperature along the center line of the MN indicate that the expansion follows a polytropic law with exponent γ_{e}=1.15±0.03. This value contradicts isothermal <span class="hlt">electron</span> expansion, γ_{e}=1, which is commonly assumed in MN models. The axial variation of the measured quantities can be described by a simple quasi-1D fluid model with classical <span class="hlt">electron</span> thermal conduction, for which it has been previously shown that a value of γ_{e}≈1.19 is expected in the weakly collisional limit. A new criterion, derived from the model, ensures efficient ion acceleration when a critical value for the ratio of convected to conducted power is exceeded.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014AGUFMSM21A..04K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014AGUFMSM21A..04K"><span>Impact of Near-Earth <span class="hlt">Plasma</span> <span class="hlt">Sheet</span> Dynamics on the Ring Current Composition</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kistler, L. M.; Mouikis, C.; Menz, A.; Spence, H. E.; Mitchell, D. G.; Gkioulidou, M.; Lanzerotti, L. J.; Skoug, R. M.; Larsen, B.; Claudepierre, S. G.; Fennell, J. F.; Blake, J. B.</p> <p>2014-12-01</p> <p>How the dynamics in the near-earth <span class="hlt">plasma</span> <span class="hlt">sheet</span> affects the heavy ion content, and therefore the ion pressure, of the ring current in Earth's magnetosphere is an outstanding question. Substorms accelerate <span class="hlt">plasma</span> in the near-earth region and drive outflow from the aurora, and both these processes can preferentially enhance the population of heavy ions in this region. These heavy ions are then driven into the inner magnetosphere during storms. Thus understanding how the composition of the ring current changes requires simultaneous observations in the near-earth <span class="hlt">plasma</span> <span class="hlt">sheet</span> and in the inner magnetosphere. We use data from the CODIF instrument on Cluster and HOPE, RBSPICE, and MagEIS instruments on the Van Allen Probes to study the acceleration and transport of ions from the <span class="hlt">plasma</span> <span class="hlt">sheet</span> into the ring current. During the main phase of a geomagnetic storm on Aug 4-6, 2013, the Cluster spacecraft were moving inbound in the midnight central <span class="hlt">plasma</span> <span class="hlt">sheet</span>, while the apogees of the two Van Allen Probes were located on the duskside. The Cluster spacecraft measure the composition and spectral changes in the <span class="hlt">plasma</span> <span class="hlt">sheet</span>, while the Van Allen Probes measure the ions that reach the inner magnetosphere. A strong increase in 1-40 keV O+ was observed at the Cluster location during the storm main phase, and the Van Allen Probes observed both H+ and O+ being driven deep into the inner magnetosphere. By comparing the variations in phase space density (PSD) vs. magnetic moment at the Cluster and the Van Allen Probes locations, we examine how the composition changes non-adiabatically in the near-earth <span class="hlt">plasma</span> <span class="hlt">sheet</span>, and how those changes are propagated into the inner magnetosphere, populating the hto ion ring current.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016NIMPA.829..254A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016NIMPA.829..254A"><span><span class="hlt">Plasma</span> production for <span class="hlt">electron</span> acceleration by resonant <span class="hlt">plasma</span> wave</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Anania, M. P.; Biagioni, A.; Chiadroni, E.; Cianchi, A.; Croia, M.; Curcio, A.; Di Giovenale, D.; Di Pirro, G. P.; Filippi, F.; Ghigo, A.; Lollo, V.; Pella, S.; Pompili, R.; Romeo, S.; Ferrario, M.</p> <p>2016-09-01</p> <p><span class="hlt">Plasma</span> wakefield acceleration is the most promising acceleration technique known nowadays, able to provide very high accelerating fields (10-100 GV/m), enabling acceleration of <span class="hlt">electrons</span> to GeV energy in few centimeter. However, the quality of the <span class="hlt">electron</span> bunches accelerated with this technique is still not comparable with that of conventional accelerators (large energy spread, low repetition rate, and large emittance); radiofrequency-based accelerators, in fact, are limited in accelerating field (10-100 MV/m) requiring therefore hundred of meters of distances to reach the GeV energies, but can provide very bright <span class="hlt">electron</span> bunches. To combine high brightness <span class="hlt">electron</span> bunches from conventional accelerators and high accelerating fields reachable with <span class="hlt">plasmas</span> could be a good compromise allowing to further accelerate high brightness <span class="hlt">electron</span> bunches coming from LINAC while preserving <span class="hlt">electron</span> beam quality. Following the idea of <span class="hlt">plasma</span> wave resonant excitation driven by a train of short bunches, we have started to study the requirements in terms of <span class="hlt">plasma</span> for SPARC_LAB (Ferrario et al., 2013 [1]). In particular here we focus on hydrogen <span class="hlt">plasma</span> discharge, and in particular on the theoretical and numerical estimates of the ionization process which are very useful to design the discharge circuit and to evaluate the current needed to be supplied to the gas in order to have full ionization. Eventually, the current supplied to the gas simulated will be compared to that measured experimentally.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.dtic.mil/docs/citations/ADA539720','DTIC-ST'); return false;" href="http://www.dtic.mil/docs/citations/ADA539720"><span>A Hybrid Kinetic Model of Asymmetric Thin Current <span class="hlt">Sheets</span> with Sheared Flows in a Collisionless <span class="hlt">Plasma</span></span></a></p> <p><a target="_blank" href="https://publicaccess.dtic.mil/psm/api/service/search/search">DTIC Science & Technology</a></p> <p></p> <p>2010-12-27</p> <p>control number. PLEASE DO NOT RETURN YOUR FORM TO THE ABOVE ADDREss. 1. REPORT DATE (DD-MM-YYVY) 12. REPORT TYPE 3 . DATES COVERED (From - To) 27-12...Current <span class="hlt">Sheets</span> ........................................ 5 3 . Asymmetric Current <span class="hlt">Sheet</span> Model ............................................. 6 3.1...Chen,l Robert A. Santoro, 2, t, Adam Szabo, 3 , and Davin E. Larson4 1 <span class="hlt">Plasma</span> Physics Division, Naval Research Laboratory, Washington, DC 2 NRC</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1999PhPl....6.1649O','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1999PhPl....6.1649O"><span>Development of <span class="hlt">plasma</span> cathode <span class="hlt">electron</span> guns</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Oks, Efim M.; Schanin, Peter M.</p> <p>1999-05-01</p> <p>The status of experimental research and ongoing development of <span class="hlt">plasma</span> cathode <span class="hlt">electron</span> guns in recent years is reviewed, including some novel upgrades and applications to various technological fields. The attractiveness of this kind of e-gun is due to its capability of creating high current, broad or focused beams, both in pulsed and steady-state modes of operation. An important characteristic of the <span class="hlt">plasma</span> cathode <span class="hlt">electron</span> gun is the absence of a thermionic cathode, a feature which leads to long lifetime and reliable operation even in the presence of aggressive background gas media and at fore-vacuum gas pressure ranges such as achieved by mechanical pumps. Depending on the required beam parameters, different kinds of <span class="hlt">plasma</span> discharge systems can be used in <span class="hlt">plasma</span> cathode <span class="hlt">electron</span> guns, such as vacuum arcs, constricted gaseous arcs, hollow cathode glows, and two kinds of discharges in crossed E×B fields: Penning and magnetron. At the present time, <span class="hlt">plasma</span> cathode <span class="hlt">electron</span> guns provide beams with transverse dimension from fractional millimeter up to about one meter, beam current from microamperes to kiloamperes, beam current density up to about 100 A/cm2, pulse duration from nanoseconds to dc, and <span class="hlt">electron</span> energy from several keV to hundreds of keV. Applications include <span class="hlt">electron</span> beam melting and welding, surface treatment, <span class="hlt">plasma</span> chemistry, radiation technologies, laser pumping, microwave generation, and more.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19780054813&hterms=runaway+electron&qs=N%3D0%26Ntk%3DTitle%26Ntx%3Dmode%2Bmatchall%26Ntt%3Drunaway%2Belectron','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19780054813&hterms=runaway+electron&qs=N%3D0%26Ntk%3DTitle%26Ntx%3Dmode%2Bmatchall%26Ntt%3Drunaway%2Belectron"><span>Spontaneous emission near the <span class="hlt">electron</span> <span class="hlt">plasma</span> frequency in a <span class="hlt">plasma</span> with a runaway <span class="hlt">electron</span> tail</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Freund, H. P.; Lee, L. C.; Wu, C. S.</p> <p>1978-01-01</p> <p>Spontaneous emission of radiation with frequencies near the <span class="hlt">electron</span> <span class="hlt">plasma</span> frequency is studied for a <span class="hlt">plasma</span> which consists of both thermal and runaway <span class="hlt">electrons</span>. It is found that a substantial enhancement of the spontaneous radiation intensity can occur in this frequency regime via a Cherenkov resonance with the runaway <span class="hlt">electrons</span>. Numerical analysis indicates that, for reasonable estimates of densities and energies, the <span class="hlt">plasma</span>-frequency radiation can attain levels greater than the peak thermal emission at the second gyroharmonic.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/21251576','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/21251576"><span><span class="hlt">Electronic</span> Broadening operator for relativistic <span class="hlt">plasmas</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Meftah, M. T.; Naam, A.</p> <p>2008-10-22</p> <p>In this work we review some aspects of the semiclassical dipole impact approximation for isolated ion lines in relativistic <span class="hlt">plasma</span>. Mainly we focuss our work on the collision operator for relativistic <span class="hlt">electrons</span>. In this case, the <span class="hlt">electron</span> trajectory around a positive charge in the <span class="hlt">plasma</span> differs drastically from those known earlier as hyperbolic. The effect of this difference on the collision operator is discussed with respect the various <span class="hlt">plasma</span> conditions. Some theoretical and practical aspects of lines -shape calculations are discussed. Detailed calculations are performed for the collision operator in the semiclassical (dipole) impact approximation.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19920071978&hterms=ion+drive&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3Dion%2Bdrive','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19920071978&hterms=ion+drive&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3Dion%2Bdrive"><span>Interaction of reflected ions with the firehose marginally stable current <span class="hlt">sheet</span> - Implications for <span class="hlt">plasma</span> <span class="hlt">sheet</span> convection</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Pritchett, P. L.; Coroniti, F. V.</p> <p>1992-01-01</p> <p>The firehose marginally stable current <span class="hlt">sheet</span>, which may model the flow away from the distant reconnection neutral line, assumes that the accelerated particles escape and never return to re-encounter the current region. This assumption fails on the earthward side where the accelerated ions mirror in the geomagnetic dipole field and return to the current <span class="hlt">sheet</span> at distances up to about 30 R(E) down the tail. Two-dimensional particle simulations are used to demonstrate that the reflected ions drive a 'shock-like' structure in which the incoming flow is decelerated and the Bz field is highly compressed. These effects are similar to those produced by adiabatic choking of steady convection. Possible implications of this interaction for the dynamics of the tail are considered.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_7");'>7</a></li> <li><a href="#" onclick='return showDiv("page_8");'>8</a></li> <li class="active"><span>9</span></li> <li><a href="#" onclick='return showDiv("page_10");'>10</a></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_9 --> <div id="page_10" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_8");'>8</a></li> <li><a href="#" onclick='return showDiv("page_9");'>9</a></li> <li class="active"><span>10</span></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="181"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2009AnGeo..27.4147H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009AnGeo..27.4147H"><span>Scale size and life time of energy conversion regions observed by Cluster in the <span class="hlt">plasma</span> <span class="hlt">sheet</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Hamrin, M.; Norqvist, P.; Marghitu, O.; Vaivads, A.; Klecker, B.; Kistler, L. M.; Dandouras, I.</p> <p>2009-11-01</p> <p>In this article, and in a companion paper by Hamrin et al. (2009) [Occurrence and location of concentrated load and generator regions observed by Cluster in the <span class="hlt">plasma</span> <span class="hlt">sheet</span>], we investigate localized energy conversion regions (ECRs) in Earth's <span class="hlt">plasma</span> <span class="hlt">sheet</span>. From more than 80 Cluster <span class="hlt">plasma</span> <span class="hlt">sheet</span> crossings (660 h data) at the altitude of about 15-20 RE in the summer and fall of 2001, we have identified 116 Concentrated Load Regions (CLRs) and 35 Concentrated Generator Regions (CGRs). By examining variations in the power density, E·J, where E is the electric field and J is the current density obtained by Cluster, we have estimated typical values of the scale size and life time of the CLRs and the CGRs. We find that a majority of the observed ECRs are rather stationary in space, but varying in time. Assuming that the ECRs are cylindrically shaped and equal in size, we conclude that the typical scale size of the ECRs is 2 RE≲ΔSECR≲5 RE. The ECRs hence occupy a significant portion of the mid altitude <span class="hlt">plasma</span> <span class="hlt">sheet</span>. Moreover, the CLRs appear to be somewhat larger than the CGRs. The life time of the ECRs are of the order of 1-10 min, consistent with the large scale magnetotail MHD simulations of Birn and Hesse (2005). The life time of the CGRs is somewhat shorter than for the CLRs. On time scales of 1-10 min, we believe that ECRs rise and vanish in significant regions of the <span class="hlt">plasma</span> <span class="hlt">sheet</span>, possibly oscillating between load and generator character. It is probable that at least some of the observed ECRs oscillate energy back and forth in the <span class="hlt">plasma</span> <span class="hlt">sheet</span> instead of channeling it to the ionosphere.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/20764396','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/20764396"><span>Recombinative <span class="hlt">plasma</span> in <span class="hlt">electron</span> runaway discharge</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Kuznetsov, Yu.K.; Galvao, R.M.O.; Usuriaga, O.C.; Krasheninnikov, S.I.; Soboleva, T.K.; Tsypin, V.S.; Fonseca, A.M.M.; Ruchko, L.F.; Sanada, E.K.</p> <p>2005-07-15</p> <p>Cold recombinative <span class="hlt">plasma</span> is the basic feature of the new regime of runaway discharges recently discovered in the Tokamak Chauffage Alfven Bresilien tokamak [R. M. O. Galvao et al., <span class="hlt">Plasma</span> Phys. Controlled Fusion 43, 1181 (2001)]. With low <span class="hlt">plasma</span> temperature, the resistive <span class="hlt">plasma</span> current and primary Dreicer process of runaway generation are strongly suppressed at the stationary phase of the discharge. In this case, the runaway avalanche, which has been recently recognized as a novel important mechanism for runaway <span class="hlt">electron</span> generation in large tokamaks, such as International Thermonuclear Experimental Reactor, during disruptions, and for electric breakdown in matter, is the only mechanism responsible for toroidal current generation and can be easily observed. The measurement of <span class="hlt">plasma</span> temperature by the usual methods is a difficult task in fully runaway discharges. In the present work, various indirect evidences for low-temperature recombinative <span class="hlt">plasma</span> are presented. The direct observation of recombinative <span class="hlt">plasma</span> is obtained as <span class="hlt">plasma</span> detachment from the limiter. The model of cold recombinative <span class="hlt">plasma</span> is also supported by measurements of <span class="hlt">plasma</span> density and H{sub {alpha}} emission radial profiles, analysis of time variations of these parameters due to the relaxation instability, estimations of <span class="hlt">plasma</span> resistivity from voltage spikes, and energy and particle balance calculations.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2006AGUFMSM41A1447V','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2006AGUFMSM41A1447V"><span>Reconnection AND Bursty Bulk Flow Associated Turbulence IN THE Earth'S <span class="hlt">Plasma</span> <span class="hlt">Sheet</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Voros, Z.; Nakamura, R.; Baumjohann, W.; Runov, A.; Volwerk, M.; Jankovicova, D.; Balogh, A.; Klecker, B.</p> <p>2006-12-01</p> <p>Reconnection related fast flows in the Earth's <span class="hlt">plasma</span> <span class="hlt">sheet</span> can be associated with several accompanying phenomena, such as magnetic field dipolarization, current <span class="hlt">sheet</span> thinning and turbulence. Statistical analysis of multi-scale properties of turbulence facilitates to understand the interaction of the <span class="hlt">plasma</span> flow with the dipolar magnetic field and to recognize the remote or nearby temporal and spatial characteristics of reconnection. The main emphasis of this presentation is on differentiating between the specific statistical features of flow associated fluctuations at different distances from the reconnection site.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=20060009468&hterms=current+sheet&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3Dcurrent%2Bsheet','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20060009468&hterms=current+sheet&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3Dcurrent%2Bsheet"><span>Dynamic Harris current <span class="hlt">sheet</span> thickness from Cluster current density and <span class="hlt">plasma</span> measurements</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Thompson, S. M.; Kivelson, M. G.; Khurana, K. K.; McPherron, R. L.; Weygand, J. M.; Balogh, A.; Reme, H.; Kistler, L. M.</p> <p>2005-01-01</p> <p>We use the first accurate measurements of current densities in the <span class="hlt">plasma</span> <span class="hlt">sheet</span> to calculate the half-thickness and position of the current <span class="hlt">sheet</span> as a function of time. Our technique assumes a Harris current <span class="hlt">sheet</span> model, which is parameterized by lobe magnetic field B(o), current <span class="hlt">sheet</span> half-thickness h, and current <span class="hlt">sheet</span> position z(sub o). Cluster measurements of magnetic field, current density, and <span class="hlt">plasma</span> pressure are used to infer the three parameters as a function of time. We find that most long timescale (6-12 hours) current <span class="hlt">sheet</span> crossings observed by Cluster cannot be described by a static Harris current <span class="hlt">sheet</span> with a single set of parameters B(sub o), h, and z(sub o). Noting the presence of high-frequency fluctuations that appear to be superimposed on lower frequency variations, we average over running 6-min intervals and use the smoothed data to infer the parameters h(t) and z(sub o)(t), constrained by the pressure balance lobe magnetic field B(sub o)(t). Whereas this approach has been used in previous studies, the spatial gnuhen& now provided by the Cluster magnetometers were unavailable or not well constrained in earlier studies. We place the calculated hdf&cknessa in a magnetospheric context by examining the change in thickness with substorm phase for three case study events and 21 events in a superposed epoch analysis. We find that the inferred half-thickness in many cases reflects the nominal changes experienced by the <span class="hlt">plasma</span> <span class="hlt">sheet</span> during substorms (i.e., thinning during growth phase, thickening following substorm onset). We conclude with an analysis of the relative contribution of (Delta)B(sub z)/(Delta)X to the cross-tail current density during substorms. We find that (Delta)B(sub z)/(Delta)X can contribute a significant portion of the cross-tail c m n t around substorm onset.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016APS..MARH15008K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016APS..MARH15008K"><span>Structural and <span class="hlt">electronic</span> properties of a single layered α-tetragonal B50 <span class="hlt">sheet</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kah, Cherno; Yu, Ming; Jayanthi, Chakram S.; Wu, Shiyu</p> <p></p> <p>Ultrathin single-crystalline boron nanosheets with α-tetragonal B50 symmetry (α-t-B50) have recently been synthesized. In this presentation, the relaxed structure of this new type of boron <span class="hlt">sheet</span> is determined using a robust self-consistent and environment-dependent semi-empirical Hamiltonian developed within the LCAO framework that includes MD and power quenching schemes. Upon relaxation, the <span class="hlt">sheet</span> symmetry is broken and the icosahedral B12 units in the <span class="hlt">sheet</span> are found to be distorted. This stability of the <span class="hlt">sheet</span> was investigated through a calculation of the vibrational frequencies. The <span class="hlt">sheet</span> <span class="hlt">electronic</span> density of states exhibits no energy gap at the Fermi level, suggesting a metallic character similar to that of the bulk α-t-B50. Finally, the cohesive energy of the α-t-B50 <span class="hlt">sheet</span> is found to be higher than that of the recently reported icosahedral B12-δ6 <span class="hlt">sheet</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2001APS..GECRF1005L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2001APS..GECRF1005L"><span><span class="hlt">Electron</span> Beam Diagnostics in <span class="hlt">Plasmas</span> Based on <span class="hlt">Electron</span> Beam Ionization</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Leonhardt, Darrin; Leal-Quiros, Edbertho; Blackwell, David; Walton, Scott; Murphy, Donald; Fernsler, Richard; Meger, Robert</p> <p>2001-10-01</p> <p>Over the last few years, <span class="hlt">electron</span> beam ionization has been shown to be a viable generator of high density <span class="hlt">plasmas</span> with numerous applications in materials modification. To better understand these <span class="hlt">plasmas</span>, we have fielded <span class="hlt">electron</span> beam diagnostics to more clearly understand the propagation of the beam as it travels through the background gas and creates the <span class="hlt">plasma</span>. These diagnostics vary greatly in sophistication, ranging from differentially pumped systems with energy selective elements to metal 'hockey pucks' covered with thin layers of insulation to electrically isolate the detector from the <span class="hlt">plasma</span> but pass high energy beam <span class="hlt">electrons</span>. Most importantly, absolute measurements of spatially resolved beam current densities are measured in a variety of pulsed and continuous beam sources. The energy distribution of the beam current(s) will be further discussed, through experiments incorporating various energy resolving elements such as simple grids and more sophisticated cylindrical lens geometries. The results are compared with other experiments of high energy <span class="hlt">electron</span> beams through gases and appropriate disparities and caveats will be discussed. Finally, <span class="hlt">plasma</span> parameters are correlated to the measured beam parameters for a more global picture of <span class="hlt">electron</span> beam produced <span class="hlt">plasmas</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19830065820&hterms=moebius&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3Dmoebius','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19830065820&hterms=moebius&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3Dmoebius"><span>Energetic particles in the vicinity of a possible neutral line in the <span class="hlt">plasma</span> <span class="hlt">sheet</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Moebius, E.; Scholer, M.; Hovestadt, D.; Paschmann, G.; Gloeckler, G.</p> <p>1983-01-01</p> <p>Combined <span class="hlt">plasma</span>, magnetic field, and energetic particle data obtained from ISEE-1 in the geomagnetic tail during two successive energetic particle burst events are presented. The behavior of protons with energies of more than about 100 keV is very different from that of the 30-100 keV protons which represent the suprathermal tail of the <span class="hlt">plasma</span> <span class="hlt">sheet</span> distribution. The more energetic ions appear on a time scale of several minutes following a northward turning of the tail magnetic field. At about the same time the <span class="hlt">plasma</span> measurements show a velocity of about 200 km/s in the tailward direction. From these results, it is argued that two successive magnetic neutral lines are created well within the <span class="hlt">plasma</span> <span class="hlt">sheet</span> and move close to the satellite position in the earthward direction. The extent of the neutral line is then limited to the dusk side of the tail.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/25666919','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/25666919"><span><span class="hlt">Electronic</span> transport properties of BN <span class="hlt">sheet</span> on adsorption of ammonia (NH3) gas.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Srivastava, Anurag; Bhat, Chetan; Jain, Sumit Kumar; Mishra, Pankaj Kumar; Brajpuriya, Ranjeet</p> <p>2015-03-01</p> <p>We report the detection of ammonia gas through <span class="hlt">electronic</span> and transport properties analysis of boron nitride <span class="hlt">sheet</span>. The density functional theory (DFT) based ab initio approach has been used to calculate the <span class="hlt">electronic</span> and transport properties of BN <span class="hlt">sheet</span> in presence of ammonia gas. Analysis confirms that the band gap of the <span class="hlt">sheet</span> increases due to presence of ammonia. Out of different positions, the bridge site is the most favorable position for adsorption of ammonia and the mechanism of interaction falls between weak electrostatic interaction and chemisorption. On relaxation, change in the bond angles of the ammonia molecule in various configurations has been reported with the distance between NH3 and the <span class="hlt">sheet</span>. An increase in the transmission of <span class="hlt">electrons</span> has been observed on increasing the bias voltage and I-V relationship. This confirms that, the current increases on applying the bias when ammonia is introduced while a very small current flows for pure BN <span class="hlt">sheet</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/20091737','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/20091737"><span>Oxygen <span class="hlt">plasma</span>-treated thermoresponsive polymer surfaces for cell <span class="hlt">sheet</span> engineering.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Shimizu, Kazunori; Fujita, Hideaki; Nagamori, Eiji</p> <p>2010-06-01</p> <p>Although cell <span class="hlt">sheet</span> tissue engineering is a potent and promising method for tissue engineering, an increase of mechanical strength of a cell <span class="hlt">sheet</span> is needed for easy manipulation of it during transplantation or 3D tissue fabrication. Previously, we developed a cell <span class="hlt">sheet</span>-polymer film complex that had enough mechanical strength that can be manipulated even by tweezers (Fujita et al., 2009. Biotechnol Bioeng 103(2): 370-377). We confirmed the polymer film involving a temperature sensitive polymer and extracellular matrix (ECM) proteins could be removed by lowering temperature after transplantation, and its potential use in regenerative medicine was demonstrated. However, the use of ECM proteins conflicted with high stability in long-term storage and low cost. In the present study, to overcome these drawbacks, we employed the oxygen <span class="hlt">plasma</span> treatment instead of using the ECM proteins. A cast and dried film of thermoresponsive poly-N-isopropylacrylamide (PNIPAAm) was fabricated and treated with high-intensity oxygen <span class="hlt">plasma</span>. The cells became possible to adhere to the oxygen <span class="hlt">plasma</span>-treated PNIPAAm surface, whereas could not to the inherent surface of bulk PNIPAAm without treatment. Characterizations of the treated surface revealed the surface had high stability. The surface roughness, wettability, and composition were changed, depending on the <span class="hlt">plasma</span> intensity. Interestingly, although bulk PNIPAAm layer had thermoresponsiveness and dissolved below lower critical solution temperature (LCST), it was found that the oxygen <span class="hlt">plasma</span>-treated PNIPAAm surface lost its thermoresponsiveness and remained insoluble in water below LCST as a thin layer. Skeletal muscle C2C12 cells could be cultured on the oxygen <span class="hlt">plasma</span>-treated PNIPAAm surface, a skeletal muscle cell <span class="hlt">sheet</span> with the insoluble thin layer could be released in the medium, and thus the possibility of use of the cell <span class="hlt">sheet</span> for transplantation was demonstrated.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017GeoRL..44....5A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017GeoRL..44....5A"><span><span class="hlt">Electron</span> currents supporting the near-Earth magnetotail during current <span class="hlt">sheet</span> thinning</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Artemyev, A. V.; Angelopoulos, V.; Liu, J.; Runov, A.</p> <p>2017-01-01</p> <p>Formation of intense, thin current <span class="hlt">sheets</span> (i.e., current <span class="hlt">sheet</span> thinning) is a critical process for magnetospheric substorms, but the kinetic physics of this process remains poorly understood. Using a triangular configuration of the three Time History of Events and Macroscale Interactions during Substorms (THEMIS) spacecraft at the end of 2015 we investigate field-aligned and transverse currents in the magnetotail current <span class="hlt">sheet</span> around 12 Earth radii downtail. Combining the curlometer technique with direct measurements of ion and <span class="hlt">electron</span> velocities, we demonstrate that intense, thin current <span class="hlt">sheets</span> supported by strong <span class="hlt">electron</span> currents form in this region. <span class="hlt">Electron</span> field-aligned currents maximize near the neutral plane Bx˜0, attaining magnitudes of ˜20 nA/m2. Carried by hot (>1 keV) <span class="hlt">electrons</span>, they generate strong magnetic shear, which contributes up to 20% of the vertical (along the normal direction to the equatorial plane) pressure balance. <span class="hlt">Electron</span> transverse currents, on the other hand, are carried by the curvature drift of anisotropic, colder (<1 keV) <span class="hlt">electrons</span> and gradually increase during the current <span class="hlt">sheet</span> thinning. In the events under consideration the thinning process was abruptly terminated by earthward reconnection fronts which have been previously associated with tail reconnection further downtail. It is likely that the thin current <span class="hlt">sheet</span> properties described herein are similar to conditions further downtail and are linked to the loss of stability and onset of reconnection there. Our findings are likely applicable to thin current <span class="hlt">sheets</span> in other geophysical and astrophysical settings.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/22086320','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/22086320"><span>RICHTMYER-MESHKOV-TYPE INSTABILITY OF A CURRENT <span class="hlt">SHEET</span> IN A RELATIVISTICALLY MAGNETIZED <span class="hlt">PLASMA</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Inoue, Tsuyoshi</p> <p>2012-11-20</p> <p>The linear stability of a current <span class="hlt">sheet</span> that is subject to an impulsive acceleration due to shock passage with the effect of a guide magnetic field is studied. We find that a current <span class="hlt">sheet</span> embedded in relativistically magnetized <span class="hlt">plasma</span> always shows a Richtmyer-Meshkov-type instability, while the stability depends on the density structure in the Newtonian limit. The growth of the instability is expected to generate turbulence around the current <span class="hlt">sheet</span>, which can induce the so-called turbulent reconnection, the rate of which is essentially free from <span class="hlt">plasma</span> resistivity. Thus, the instability can be applied as a triggering mechanism for rapid magnetic energy release in a variety of high-energy astrophysical phenomena such as pulsar wind nebulae, gamma-ray bursts, and active galactic nuclei, where the shock wave is thought to play a crucial role.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19970016593&hterms=balance+sheet+energy&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3Dbalance%2Bsheet%2Benergy','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19970016593&hterms=balance+sheet+energy&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3Dbalance%2Bsheet%2Benergy"><span>Estimates of magnetic flux, and energy balance in the <span class="hlt">plasma</span> <span class="hlt">sheet</span> during substorm expansion</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Hesse, Michael; Birn, Joachim; Pulkkinen, Tuija</p> <p>1996-01-01</p> <p>The energy and magnetic flux budgets of the magnetotail <span class="hlt">plasma</span> <span class="hlt">sheet</span> during substorm expansion are investigated. The possible mechanisms that change the energy content of the closed field line region which contains all the major dissipation mechanisms of relevance during substorms, are considered. The compression of the <span class="hlt">plasma</span> <span class="hlt">sheet</span> mechanism and the diffusion mechanism are considered and excluded. It is concluded that the magnetic reconnection mechanism can accomplish the required transport. Data-based empirical magnetic field models are used to investigate the magnetic flux transport required to account for the observed magnetic field dipolarizations in the inner magnetosphere. It is found that the magnetic flux permeating the current <span class="hlt">sheet</span> is typically insufficient to supply the required magnetic flux. It is concluded that no major substorm-type magnetospheric reconfiguration is possible in the absence of magnetic reconnection.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014AGUFMSM23C4245S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014AGUFMSM23C4245S"><span>Effects of Bursty Bulk Flows on the Turbulence in the <span class="hlt">Plasma</span> <span class="hlt">Sheet</span>.</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Stepanova, M. V.; Antonova, E. E.</p> <p>2014-12-01</p> <p>Recent studies have shown the importance of turbulent processes in the dynamics of the magnetosphere of the Earth, including <span class="hlt">plasma</span> and energy transport and the <span class="hlt">plasma</span> <span class="hlt">sheet</span> stability. We studied the properties of the turbulent <span class="hlt">plasma</span> <span class="hlt">sheet</span> in the presence and in the absence of the bursty bulk flow events for different phases of geomagnetic substorms and for quiet geomagnetic conditions. The criteria used for the selection of BBFs are similar to ones established by Angelopoulos et al., (JGR, 1994). The classification of time intervals as quiet, expansion phase, and recovery phase was based on the variation of the AL-index (Stepanova et al., 2011). Statistical analysis was performed using the data of THEMIS probes during tail-science seasons. It was found that the <span class="hlt">plasma</span> pressure is the parameter which experienced major variation if we compare the data for different substrom phases, and also in the presence and absence of BBFs: The radial <span class="hlt">plasma</span> pressure profiles are steaper during the substorm expansion phase, the presence of BBFs smoothes this effect, especially during the recovery phase and the quiet time. Study of eddy diffusion showed that even in the absence of BBFs the <span class="hlt">plasma</span> <span class="hlt">sheet</span> is strongly turbulent. Analysis of bulk velocity data 20 minutes before and after a BBF showed that the BBFs could generate additional vorticity at the leading and trailing edges, but their contribution is not decisive.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/20782390','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/20782390"><span>Runaway <span class="hlt">electron</span> generation in a cooling <span class="hlt">plasma</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Smith, H.; Helander, P.; Eriksson, L.-G.; Fueloep, T.</p> <p>2005-12-15</p> <p>The usual calculation of Dreicer [Phys. Rev. 115, 238 (1959); 117, 329 (1960)] generation of runaway <span class="hlt">electrons</span> assumes that the <span class="hlt">plasma</span> is in a steady state. In a tokamak disruption this is not necessarily true since the <span class="hlt">plasma</span> cools down quickly and the collision time for <span class="hlt">electrons</span> at the runaway threshold energy can be comparable to the cooling time. The <span class="hlt">electron</span> distribution function then acquires a high-energy tail which can easily be converted to a burst of runaways by the rising electric field. This process is investigated and simple criteria for its importance are derived. If no rapid losses of fast <span class="hlt">electrons</span> occur, this can be a more important source of runaway <span class="hlt">electrons</span> than ordinary Dreicer generation in tokamak disruptions.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19970026617','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19970026617"><span>Penetration of the Interplanetary Magnetic Field B(sub y) into Earth's <span class="hlt">Plasma</span> <span class="hlt">Sheet</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Hau, L.-N.; Erickson, G. M.</p> <p>1995-01-01</p> <p>There has been considerable recent interest in the relationship between the cross-tail magnetic field component B(sub y) and tail dynamics. The purpose of this paper is to give an overall description of the penetration of the interplanetary magnetic field (IMF) B(sub y) into the near-Earth <span class="hlt">plasma</span> <span class="hlt">sheet</span>. We show that <span class="hlt">plasma</span> <span class="hlt">sheet</span> B(sub y) may be generated by the differential shear motion of field lines and enhanced by flux tube compression. The latter mechanism leads to a B(sub y) analogue of the pressure-balance inconsistency as flux tubes move from the far tail toward the Earth. The growth of B(sub y), however, may be limited by the dawn-dusk asymmetry in the shear velocity as a result of <span class="hlt">plasma</span> <span class="hlt">sheet</span> tilting. B(sub y) penetration into the <span class="hlt">plasma</span> <span class="hlt">sheet</span> implies field-aligned currents flowing between hemispheres. These currents together with the IMF B(sub y) related mantle field-aligned currents effectively shield the lobe from the IMF B(sub y).</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/6399325','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/6399325"><span>Characterization of <span class="hlt">electron</span> cyclotron resonance hydrogen <span class="hlt">plasmas</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Outten, C.A. . Dept. of Nuclear Engineering); Barbour, J.C.; Wampler, W.R. )</p> <p>1990-01-01</p> <p><span class="hlt">Electron</span> cyclotron resonance (ECR) <span class="hlt">plasmas</span> yield low energy and high ion density <span class="hlt">plasmas</span>. The characteristics downstream of an ECR hydrogen <span class="hlt">plasma</span> were investigated as a function of microwave power and magnetic field. A fast-injection Langmuir probe and a carbon resistance probe were used to determine <span class="hlt">plasma</span> potential (V{sub p}), <span class="hlt">electron</span> density (N{sub e}), <span class="hlt">electron</span> temperature (T{sub e}), ion energy (T{sub i}), and ion fluence. Langmuir probe results showed that at 17 cm downstream from the ECR chamber the <span class="hlt">plasma</span> characteristics are approximately constant across the center 7 cm of the <span class="hlt">plasma</span> for 50 Watts of absorbed power. These results gave V{sub p} = 30 {plus minus} 5 eV, N{sub e} = 1 {times} 10{sup 8} cm{sup {minus}3}, and T{sub e} = 10--13 eV. In good agreement with the Langmuir probe results, carbon resistance probes have shown that T{sub i} {le} 50 eV. Also, based on hydrogen chemical sputtering of carbon, the hydrogen (ion and energetic neutrals) fluence rate was determined to be 1 {times} 10{sup 16}/cm{sup 2}-sec. at a pressure of 1 {times} 10{sup {minus}4} Torr and for 50 Watts of absorbed power. 19 refs.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013NaPho...7..932.','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013NaPho...7..932."><span>Tamm states in <span class="hlt">electron</span> <span class="hlt">plasma</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p></p> <p>2013-11-01</p> <p>Researchers have fabricated a voltage-tunable plasmonic crystal in a two-dimensional <span class="hlt">electron</span> gas that operates at terahertz frequencies. Nature Photonics spoke to Eric Shaner, Greg Dyer and Greg Aizin about the observation of Tamm states at the crystal's edge.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1989pthp.work.....M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1989pthp.work.....M"><span>Launched <span class="hlt">electrons</span> in <span class="hlt">plasma</span> opening switches</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Mendel, C. W., Jr.; Rochau, G. E.; Sweeney, M. A.; McDaniel, D. H.; Quintenz, J. P.; Savage, M. E.; Lindman, E. L.; Kindel, J. M.</p> <p></p> <p><span class="hlt">Plasma</span> opening switches have provided a means to improve the characteristics of super-power pulse generators. Recent advances involving <span class="hlt">plasma</span> control with fast and slow magnetic fields have made these switches more versatile, allowing for improved switch uniformity, triggering, and opening current levels that are set by the level of auxiliary fields. Such switches necessarily involve breaks in the translational symmetry of the transmission line geometry and therefore affect the <span class="hlt">electron</span> flow characteristics of the line. These symmetry breaks are the result of high electric field regions caused by <span class="hlt">plasma</span> conductors remaining in the transmission line, ion beams crossing the line, or auxilliary magnetic field regions. Symmetry breaks cause the canonical momentum of the <span class="hlt">electrons</span> to change, thereby moving them away from the cathode. Additional <span class="hlt">electrons</span> are pulled from the cathode into the magnetically insulated flow, resulting in an excess of <span class="hlt">electron</span> flow over that expected for the voltage and line current downstream of the switch. These <span class="hlt">electrons</span> are called launched <span class="hlt">electrons</span>. Unless they are recaptured at the cathode or else are fed into the load and used beneficially, they cause a large power loss downstream. Examples are shown of SuperMite and PBFA II data showing these losses, the tools used to study them are explained, and the mechanisms employed to mitigate the problem are discussed. The losses will be reduced primarily by reducing the amount of launched <span class="hlt">electron</span> flow.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/22269257','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/22269257"><span><span class="hlt">Electronic</span> and magnetic properties of Fe and Mn doped two dimensional hexagonal germanium <span class="hlt">sheets</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Soni, Himadri R. Jha, Prafulla K.</p> <p>2014-04-24</p> <p>Using first principles density functional theory calculations, the present paper reports systematic total energy calculations of the <span class="hlt">electronic</span> properties such as density of states and magnetic moment of pristine and iron and manganese doped two dimensional hexagonal germanium <span class="hlt">sheets</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19830026601','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19830026601"><span>Survey of low energy <span class="hlt">plasma</span> <span class="hlt">electrons</span> in Saturn's magnetosphere: Voyagers 1 and 2</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Sittler, E. C., Jr.; Ogilvie, K. W.; Scudder, J. D.</p> <p>1983-01-01</p> <p>The low energy <span class="hlt">plasma</span> <span class="hlt">electron</span> environment within Saturn's magnetosphere was surveyed by the <span class="hlt">Plasma</span> Science Experiment (PLS) during the Voyager encounters with Saturn. Over the full energy range of the PLS instrument (10 eV to 6 keV) the <span class="hlt">electron</span> distribution functions are clearly non-Maxwellian in character; they are composed of a cold (thermal) component with Maxwellian shape and a hot (suprathermal) non-Maxwellian component. A large scale positive radial gradient in <span class="hlt">electron</span> temperature is observed, increasing from less than 1 eV in the inner magnetosphere to as high as 800 eV in the outer magnetosphere. Three fundamentally different <span class="hlt">plasma</span> regimes were identified from the measurements: (1) the hot outer magnetosphere, (2) the extended <span class="hlt">plasma</span> <span class="hlt">sheet</span>, and (3) the inner <span class="hlt">plasma</span> torus.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_8");'>8</a></li> <li><a href="#" onclick='return showDiv("page_9");'>9</a></li> <li class="active"><span>10</span></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_10 --> <div id="page_11" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_9");'>9</a></li> <li><a href="#" onclick='return showDiv("page_10");'>10</a></li> <li class="active"><span>11</span></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="201"> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19840043373&hterms=balsiger&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3Dbalsiger','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19840043373&hterms=balsiger&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3Dbalsiger"><span>The structure of the <span class="hlt">plasma</span> <span class="hlt">sheet</span>-lobe boundary in the earth's magnetotail</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Orsini, S.; Candidi, M.; Formisano, V.; Balsiger, H.; Ghielmetti, A.; Ogilvie, K. W.</p> <p>1984-01-01</p> <p>The structure of the magnetotail <span class="hlt">plasma</span> <span class="hlt">sheet-plasma</span> lobe boundary was studied by observing the properties of tailward flowing O+ ion beams, detected by the ISEE 2 <span class="hlt">plasma</span> experiment inside the boundary during three time periods. The computed value of the north-south electric field component as well as the O+ parameters are shown to change at the boundary. The results are related to other observations made in this region. The O+ parameters and the Ez component behavior are shown to be consistent with that expected from the topology of the electric field lines in the tail as mapped from the ionosphere. Previously announced in STAR as N84-13049</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19840004981','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19840004981"><span>The structure of the <span class="hlt">plasma</span> <span class="hlt">sheet</span>-lobe boundary in the Earth's magnetotail</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Orsini, S.; Candidi, M.; Formisano, V.; Balsiger, H.; Ghielmetti, A.; Ogilvie, K. W.</p> <p>1982-01-01</p> <p>The structure of the magnetotail <span class="hlt">plasma</span> <span class="hlt">sheet-plasma</span> lobe boundary was studied by observing the properties of tailward flowing O+ ion beams, detected by the ISEE 2 <span class="hlt">plasma</span> experiment inside the boundary during three time periods. The computed value of the north-south electric field component as well as the O+ parameters are shown to change at the boundary. The results are related to other observations made in this region. The O+ parameters and the Ez component behavior are shown to be consistent with that expected from the topology of the electric field lines in the tail as mapped from the ionosphere.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014PhDT........18N','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014PhDT........18N"><span><span class="hlt">Electron</span> density measurements for <span class="hlt">plasma</span> adaptive optics</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Neiswander, Brian W.</p> <p></p> <p>Over the past 40 years, there has been growing interest in both laser communications and directed energy weapons that operate from moving aircraft. As a laser beam propagates from an aircraft in flight, it passes through boundary layers, turbulence, and shear layers in the near-region of the aircraft. These fluid instabilities cause strong density gradients which adversely affect the transmission of laser energy to a target. Adaptive optics provides corrective measures for this problem but current technology cannot respond quickly enough to be useful for high speed flight conditions. This research investigated the use of <span class="hlt">plasma</span> as a medium for adaptive optics for aero-optics applications. When a laser beam passes through <span class="hlt">plasma</span>, its phase is shifted proportionally to the <span class="hlt">electron</span> density and gas heating within the <span class="hlt">plasma</span>. As a result, <span class="hlt">plasma</span> can be utilized as a dynamically controllable optical medium. Experiments were carried out using a cylindrical dielectric barrier discharge <span class="hlt">plasma</span> chamber which generated a sub-atmospheric pressure, low-temperature <span class="hlt">plasma</span>. An electrostatic model of this design was developed and revealed an important design constraint relating to the geometry of the chamber. Optical diagnostic techniques were used to characterize the <span class="hlt">plasma</span> discharge. Single-wavelength interferometric experiments were performed and demonstrated up to 1.5 microns of optical path difference (OPD) in a 633 nm laser beam. Dual-wavelength interferometry was used to obtain time-resolved profiles of the <span class="hlt">plasma</span> <span class="hlt">electron</span> density and gas heating inside the <span class="hlt">plasma</span> chamber. Furthermore, a new multi-wavelength infrared diagnostic technique was developed and proof-of-concept simulations were conducted to demonstrate the system's capabilities.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013AGUFMSM12B..06R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013AGUFMSM12B..06R"><span>Multifluid MHD simulation of Saturn's magnetosphere: Dynamics of mass- and momentum-loading, and seasonal variation of the <span class="hlt">plasma</span> <span class="hlt">sheet</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Rajendar, A.; Paty, C. S.; Arridge, C. S.; Jackman, C. M.; Smith, H. T.</p> <p>2013-12-01</p> <p>Saturn's magnetosphere is driven externally, by the solar wind, and internally, by the planet's strong magnetic field, rapid rotation rate, and the addition of new <span class="hlt">plasma</span> created from Saturn's neutral cloud. Externally, the alignment of the rotational and magnetic dipole axes, combined with Saturn's substantial inclination to its plane of orbit result in substantial curvature of the <span class="hlt">plasma</span> <span class="hlt">sheet</span> during solstice. Internally, new water group ions are produced in the inner regions of the magnetosphere from photoionization and <span class="hlt">electron</span>-impact ionization of the water vapor and OH cloud sourced from Enceladus and other icy bodies in Saturn's planetary system. In addition to this, charge-exchange collisions between the relatively fast-moving water group ions and the slower neutrals results in a net loss of momentum from the <span class="hlt">plasma</span>. In order to study these phenomena, we have made significant modifications to the Saturn multifluid model. This model has been previously used to investigate the external triggering of plasmoids and the interchange process using a fixed internal source rate. In order to improve the fidelity of the model, we have incorporated a physical source of mass- and momentum-loading by including an empirical representation of Saturn's neutral cloud and modifying the multifluid MHD equations to include mass- and momentum-loading terms. Collision cross-sections between ions, <span class="hlt">electrons</span>, and neutrals are calculated as functions of closure velocity and energy at each grid point and time step, enabling us to simulate the spatially and temporally varying <span class="hlt">plasma</span>-neutral interactions. In addition to this, by altering the angle of incidence of the solar wind relative to Saturn's rotational axis and applying a realistic latitudinally- and seasonally-varying ionospheric conductivity, we are also able to study seasonal effects on Saturn's magnetosphere. We use the updated multifluid simulation to investigate the dynamics of Saturn's magnetosphere, focusing specifically</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/22053125','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/22053125"><span>Kink-like mode of a double gradient instability in a compressible <span class="hlt">plasma</span> current <span class="hlt">sheet</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Korovinskiy, D B; Ivanova, V V; Erkaev, N V; Semenov, V S; Ivanov, I B; Biernat, H K; Zellinger, M</p> <p>2011-11-01</p> <p>A linear MHD instability of the electric current <span class="hlt">sheet</span>, characterized by a small normal magnetic field component, varying along the <span class="hlt">sheet</span>, is investigated. The tangential magnetic field component is modeled by a hyperbolic function, describing Harris-like variations of the field across the <span class="hlt">sheet</span>. For this problem, which is formulated in a 3D domain, the conventional compressible ideal MHD equations are applied. By assuming Fourier harmonics along the electric current, the linearized 3D equations are reduced to 2D ones. A finite difference numerical scheme is applied to examine the time evolution of small initial perturbations of the <span class="hlt">plasma</span> parameters. This work is an extended numerical study of the so called "double gradient instability", - a possible candidate for the explanation of flapping oscillations in the magnetotail current <span class="hlt">sheet</span>, which has been analyzed previously in the framework of a simplified analytical approach for an incompressible <span class="hlt">plasma</span>. The dispersion curve is obtained for the kink-like mode of the instability. It is shown that this curve demonstrates a quantitative agreement with the previous analytical result. The development of the instability is investigated also for various enhanced values of the normal magnetic field component. It is found that the characteristic values of the growth rate of the instability shows a linear dependence on the square root of the parameter, which scales uniformly the normal component of the magnetic field in the current <span class="hlt">sheet</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2002cosp...34E1131W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2002cosp...34E1131W"><span>Modeling the inner <span class="hlt">plasma</span> <span class="hlt">sheet</span> pressure and magnetic field under enhanced convection</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Wang, C.; Lyons, L.; Chen, M.; Wolf, R.</p> <p></p> <p>In order to understand the evolution of the proton pressure and magnetic field in the inner <span class="hlt">plasma</span> <span class="hlt">sheet</span> from quiet to disturbed times, we incorporate a modified version of the Magnetospheric Specification Model with a modified version of the Tsyganenko 96 magnetic field model to self-consistently simulate protons and magnetic field under an increasing convection electric field with two-dimensional force balance maintained along the midnight meridian. The local-time dependent proton differential fluxes assigned to the model boundary are mixture of hot <span class="hlt">plasma</span> from the distant tail and cooler <span class="hlt">plasma</span> from the low latitude boundary layer and are constructed based on Geotail observations and the results of the finite-tail-width- convection model. We previously used this model to simulate the inner <span class="hlt">plasma</span> <span class="hlt">sheet</span> under weak convection corresponding to a cross polar-cap potential drop ( PC) equal to 26 kV and obtained two-dimensional quiet time equilibrium for proton and magnetic field that agrees well with observations both qualitatively and quantitatively. We start our simulation for enhanced convection with this quiet time equilibrium and time independent boundary particle sources and increase thePC steadily from 26 kV to 146 kV in 5 hours. The simulations are also run to steady states separately by keepingP C constant after it is increased to 98 and to 146 kV. The magnitude of the simulated proton pressure and its increase from quiet to moderate activity ( P C = 98 kV) are consistent with most observations. Our results at high activity (P C = 146 kV) underestimate the observed pressure, a disagreement that indicates possible dependence of the boundary particle sources on activity. The pressure equatorial profiles show a dawn dusk asymmetry as a result of stronger enhancement on the dusk side than on the dawn side as convection is increased. The equatorial m gnetic field strength decreases more in the near-Eartha <span class="hlt">plasma</span> <span class="hlt">sheet</span> than at larger radial distances as theP C</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014APS..DPPNO5002H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014APS..DPPNO5002H"><span>The Self-Consistent Generation of Current <span class="hlt">Sheets</span> in Astrophysical <span class="hlt">Plasma</span> Turbulence</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Howes, Gregory</p> <p>2014-10-01</p> <p>In space and astrophysical <span class="hlt">plasma</span> turbulence, it has long been recognized that dissipation occurs predominantly in intermittent current <span class="hlt">sheets</span>, with vigorous activity in the past few years focused on obtaining observational evidence for such localized dissipation in the near-Earth solar wind. The nature of these magnetic discontinuities and their associated current <span class="hlt">sheets</span> measured in the solar wind remains unclear--are these discontinuities due to filamentary magnetic structure in the solar wind, or do they arise dynamically from turbulent interactions? Recent analytical solution, numerical validation, and experimental verification of the nonlinear energy transfer in Alfven wave collisions, the nonlinear interactions between counterpropagating Alfven waves, has established this interaction as the fundamental building block of astrophysical <span class="hlt">plasma</span> turbulence. Here I will present first-principles analytical calculations and supporting numerical simulations that Alfven wave collisions in the strong turbulence limit naturally produce current <span class="hlt">sheets</span>, providing the first theoretical unification of models of <span class="hlt">plasma</span> turbulence mediated by Alfven waves with ideas on localized dissipation in current <span class="hlt">sheets</span>. Supported by NSF CAREER Award AGS-1054061, NSF Grant PHY-10033446, and NASA Grant NNX10AC91G.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19910023729','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19910023729"><span>High resolution measurements of density structures in the Jovian <span class="hlt">plasma</span> <span class="hlt">sheet</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Ansher, J. A.; Kurth, W. S.; Gurnett, D. A.; Goertz, C. K.</p> <p>1991-01-01</p> <p>A recent effort to digitize the <span class="hlt">plasma</span> density by using the low frequency cutoff of trapped continuum radiation in the vicinity of the Jovian <span class="hlt">plasma</span> <span class="hlt">sheet</span> has revealed the existence of sharply defined density structures in the <span class="hlt">plasma</span> <span class="hlt">sheet</span>. These structures typically have a <span class="hlt">plasma</span> density which is relatively constant but of order 50 percent greater or less than in the surrounding <span class="hlt">plasma</span>. At the boundaries of these structures, the transitions from low to high density occur on time scales of about ten seconds, which correspond to spatial dimensions on the order of a few ion Larmor radii. The structures themselves last for intervals from less than a minute to more than five minutes, corresponding to size scales from a fraction of a Jovian radius to more than a Jovian radius, depending of the velocity of the structure relative to the spacecraft. In view of the importance of near corotation <span class="hlt">plasma</span> flows, these structures are likely to be limited in both the longitudinal and radial dimensions and, therefore, could represent flux tubes with greatly varying <span class="hlt">plasma</span> content. These observations are presented as among the first to directly address the theoretically proposed interchange instability.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014PhPl...21k2306A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014PhPl...21k2306A"><span>Nonquasineutral <span class="hlt">electron</span> vortices in nonuniform <span class="hlt">plasmas</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Angus, J. R.; Richardson, A. S.; Ottinger, P. F.; Swanekamp, S. B.; Schumer, J. W.</p> <p>2014-11-01</p> <p><span class="hlt">Electron</span> vortices are observed in the numerical simulation of current carrying <span class="hlt">plasmas</span> on fast time scales where the ion motion can be ignored. In <span class="hlt">plasmas</span> with nonuniform density n, vortices drift in the B × ∇n direction with a speed that is on the order of the Hall speed. This provides a mechanism for magnetic field penetration into a <span class="hlt">plasma</span>. Here, we consider strong vortices with rotation speeds Vϕ close to the speed of light c where the vortex size δ is on the order of the magnetic Debye length λB=|B |/4 πe n and the vortex is thus nonquasineutral. Drifting vortices are typically studied using the <span class="hlt">electron</span> magnetohydrodynamic model (EMHD), which ignores the displacement current and assumes quasineutrality. However, these assumptions are not strictly valid for drifting vortices when δ ≈ λB. In this paper, 2D <span class="hlt">electron</span> vortices in nonuniform <span class="hlt">plasmas</span> are studied for the first time using a fully electromagnetic, collisionless fluid code. Relatively large amplitude oscillations with periods that correspond to high frequency extraordinary modes are observed in the average drift speed. The drift speed W is calculated by averaging the <span class="hlt">electron</span> velocity field over the vorticity. Interestingly, the time-averaged W from these simulations matches very well with W from the much simpler EMHD simulations even for strong vortices with order unity charge density separation.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/22403262','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/22403262"><span>Nonquasineutral <span class="hlt">electron</span> vortices in nonuniform <span class="hlt">plasmas</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Angus, J. R.; Richardson, A. S.; Swanekamp, S. B.; Schumer, J. W.; Ottinger, P. F.</p> <p>2014-11-15</p> <p><span class="hlt">Electron</span> vortices are observed in the numerical simulation of current carrying <span class="hlt">plasmas</span> on fast time scales where the ion motion can be ignored. In <span class="hlt">plasmas</span> with nonuniform density n, vortices drift in the B × ∇n direction with a speed that is on the order of the Hall speed. This provides a mechanism for magnetic field penetration into a <span class="hlt">plasma</span>. Here, we consider strong vortices with rotation speeds V{sub ϕ} close to the speed of light c where the vortex size δ is on the order of the magnetic Debye length λ{sub B}=|B|/4πen and the vortex is thus nonquasineutral. Drifting vortices are typically studied using the <span class="hlt">electron</span> magnetohydrodynamic model (EMHD), which ignores the displacement current and assumes quasineutrality. However, these assumptions are not strictly valid for drifting vortices when δ ≈ λ{sub B}. In this paper, 2D <span class="hlt">electron</span> vortices in nonuniform <span class="hlt">plasmas</span> are studied for the first time using a fully electromagnetic, collisionless fluid code. Relatively large amplitude oscillations with periods that correspond to high frequency extraordinary modes are observed in the average drift speed. The drift speed W is calculated by averaging the <span class="hlt">electron</span> velocity field over the vorticity. Interestingly, the time-averaged W from these simulations matches very well with W from the much simpler EMHD simulations even for strong vortices with order unity charge density separation.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/5648915','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/5648915"><span>Radiative <span class="hlt">electron</span> capture in nonequilibrium <span class="hlt">plasmas</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Milchberg, H.M.; Weisheit, J.C.</p> <p>1982-01-19</p> <p>Formulae have been obtained for the degree of linear polarization of recombination radiation from a homogeneous <span class="hlt">plasma</span> having an anisotropic <span class="hlt">electron</span> velocity distribution, f(v vector), characterized by an axis of symmetry. Polarization measurements are described which utilize these formulae to determine aspects of the anisotropy such as the symmetry axis direction and the lowest order even angular moments of f(v vector). As a special case, if the <span class="hlt">plasma</span> conforms to a distribution such as a bi-Maxwellian with drift, one can determine the quantities u/sub D//T/sub parallel to/ and (1/T/sub parallel to/ - 1/T/sub perpendicular to/) which involve the <span class="hlt">electron</span> drift speed, and the perpendicular and parallel <span class="hlt">electron</span> temperatures. Also, the radiative recombination rate has been calculated for ions whose speeds are comparable to or greater than the <span class="hlt">electron</span> thermal speed. The change in the rate is small for thermonuclear products in fusion <span class="hlt">plasmas</span>, but large for cosmic rays in interstellar <span class="hlt">plasma</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016PhPl...23h2122A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016PhPl...23h2122A"><span>Twisted <span class="hlt">electron</span>-acoustic waves in <span class="hlt">plasmas</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Aman-ur-Rehman, Ali, S.; Khan, S. A.; Shahzad, K.</p> <p>2016-08-01</p> <p>In the paraxial limit, a twisted <span class="hlt">electron</span>-acoustic (EA) wave is studied in a collisionless unmagnetized <span class="hlt">plasma</span>, whose constituents are the dynamical cold <span class="hlt">electrons</span> and Boltzmannian hot <span class="hlt">electrons</span> in the background of static positive ions. The analytical and numerical solutions of the <span class="hlt">plasma</span> kinetic equation suggest that EA waves with finite amount of orbital angular momentum exhibit a twist in its behavior. The twisted wave particle resonance is also taken into consideration that has been appeared through the effective wave number qeff accounting for Laguerre-Gaussian mode profiles attributed to helical phase structures. Consequently, the dispersion relation and the damping rate of the EA waves are significantly modified with the twisted parameter η, and for η → ∞, the results coincide with the straight propagating plane EA waves. Numerically, new features of twisted EA waves are identified by considering various regimes of wavelength and the results might be useful for transport and trapping of <span class="hlt">plasma</span> particles in a two-<span class="hlt">electron</span> component <span class="hlt">plasma</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016EGUGA..18.4170J','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016EGUGA..18.4170J"><span>A Statistical study of <span class="hlt">plasma</span> <span class="hlt">sheet</span> oscillations with kinetic ballooning/interchange instability signatures using THEMIS spacecraft</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Jurisic, Mirjana; Panov, Evgeny; Nakamura, Rumi; Baumjohann, Wolfgang</p> <p>2016-04-01</p> <p>We use THEMIS data from 2010-2012 tail seasons to collect observations of <span class="hlt">plasma</span> <span class="hlt">sheet</span> oscillations with kinetic ballooning/interchange instability (BICI) signatures. Over seventy observations with closely located THEMIS probes P3-P5 reveal that BICI-like <span class="hlt">plasma</span> <span class="hlt">sheet</span> oscillations may appear at different magnetic local time. For these, we derive background <span class="hlt">plasma</span> <span class="hlt">sheet</span> parameters such as BZ, δBZ/δx and <span class="hlt">plasma</span> beta, and investigate solar wind conditions. We also estimate the proper parameters of BICI-like oscillations such as frequency and amplitude. Based on this, we search for a relation between the background <span class="hlt">plasma</span> <span class="hlt">sheet</span> parameters and the proper parameters of BICI-like oscillations.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/5098756','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/5098756"><span><span class="hlt">Plasma</span> <span class="hlt">sheets</span>, <span class="hlt">plasma</span> currents and electric field double layers in the equatorial ionosphere</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Gupta, S.P.</p> <p>1981-01-01</p> <p><span class="hlt">Plasma</span> measurements carried out in the equatorial ionosphere at altitudes of 80-200 km are discussed. It is found that within this region the ion collision frequency exceeds the gyro-frequency. For <span class="hlt">electrons</span>, however, the collision frequency is much lower than their gyro-frequency. It is pointed out that the earth's magnetic field is horizontal in the equatorial ionosphere, particularly at altitudes of approximately 100 km, where the curvature of the magnetic field can be neglected. The results obtained from rocket-borne probes in the equatorial ionosphere over Thumba (India) are presented. Localized regions illustrating the polarity of the vertical electric field are shown, as are current density profiles obtained at different times of the day. It is found that as expected, the vertical electric field becomes very small during a weak magnetic storm.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015AGUFMSM51E2600Z','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015AGUFMSM51E2600Z"><span>An Intrinsically Three-Dimensional Reconnection Process in Near-Earth <span class="hlt">Plasma</span> <span class="hlt">Sheet</span>*</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Zhu, P.; Sangari, A.; Bonofiglo, P.; Wang, Z.</p> <p>2015-12-01</p> <p>A magnetic reconnection process in the near-Earth <span class="hlt">plasma</span> <span class="hlt">sheet</span> has been revealed to be intrinsically three-dimensional both geometrically and dynamically despite the spatial invariance of the original current <span class="hlt">sheet</span> in the equilibrium current direction. Such a reconnection process is induced by the nonlinear development of an ideal MHD ballooning instability that leads to the appearance of quasi-separatrix layers in a generalized Harris <span class="hlt">sheet</span>. The spatial distribution and structure of these quasi-separatrix layers, as well as their temporal evolution, indicate that the associated magnetic reconnection can only occur in the three-dimensional geometry which is irreducible to a two-dimensional reconnection process. *Supported by National Natural Science Foundation of China Grant No. 41474143.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19720058741&hterms=Diamagnetic&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3DDiamagnetic','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19720058741&hterms=Diamagnetic&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3DDiamagnetic"><span>On the diamagnetic effect of the <span class="hlt">plasma</span> <span class="hlt">sheet</span> near 60 earth radii.</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Meng, C.-I.; Mihalov, J. D.</p> <p>1972-01-01</p> <p>The two-dimensional (YZ plane) spatial distribution of magnetic field magnitudes in the geomagnetic tail at the lunar distance is given in both the solar magnetospheric and the neutral-<span class="hlt">sheet</span> coordinate systems by using three years of data from the Ames magnetometer on Explorer 35. The effect of changes in geomagnetic activity is also presented. In the magnetotail near 60 earth radii, a broad region in which the magnetic field intensity is relatively weak in comparison with that in the other region of the tail is located adjacent to the solar magnetospheric equatorial plane and the calculated neutral <span class="hlt">sheet</span>. This depression of the field due to the diamagnetic effect of the <span class="hlt">plasma</span> <span class="hlt">sheet</span> is more evident during times of minimum geomagnetic activity.-</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19770028218&hterms=ohms+law&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3Dohms%2Blaw','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19770028218&hterms=ohms+law&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3Dohms%2Blaw"><span>High conductivity magnetic tearing instability. [of neutral <span class="hlt">plasma</span> <span class="hlt">sheets</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Cross, M. A.; Van Hoven, G.</p> <p>1976-01-01</p> <p>Linearized equations of magnetohydrodynamics are used to investigate the tearing mode, for arbitrary values of the conductivity, through a consideration of the additional effect of the <span class="hlt">electron</span>-inertia contribution to Ohm's law. A description is provided of the equilibrium and subsequent instability in the magnetohydrodynamic approximation. A method for solving the perturbation equations in the linear approximation is discussed and attention is given to the results in the high conductivity limit.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=20080037619&hterms=Goldstein&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D80%26Ntt%3DGoldstein','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20080037619&hterms=Goldstein&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D80%26Ntt%3DGoldstein"><span>Using PEACE Data from the four CLUSTER Spacecraft to Measure Compressibility, Vorticity, and the Taylor Microscale in the Magnetosheath and <span class="hlt">Plasma</span> <span class="hlt">Sheet</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Goldstein, Melvyn L.; Parks, George; Gurgiolo, C.; Fazakerley, Andrew N.</p> <p>2008-01-01</p> <p>We present determinations of compressibility and vorticity in the magnetosheath and <span class="hlt">plasma</span> <span class="hlt">sheet</span> using moments from the four PEACE thermal <span class="hlt">electron</span> instruments on CLUSTER. The methodology used assumes a linear variation of the moments throughout the volume defined by the four satellites, which allows spatially independent estimates of the divergence, curl, and gradient. Once the vorticity has been computed, it is possible to estimate directly the Taylor microscale. We have shown previously that the technique works well in the solar wind. Because the background flow speed in the magnetosheath and <span class="hlt">plasma</span> <span class="hlt">sheet</span> is usually less than the Alfven speed, the Taylor frozen-in-flow approximation cannot be used. Consequently, this four spacecraft approach is the only viable method for obtaining the wave number properties of the ambient fluctuations. Our results using <span class="hlt">electron</span> velocity moments will be compared with previous work using magnetometer data from the FGM experiment on Cluster.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016ApPhR...8...64E','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016ApPhR...8...64E"><span>Nonlinear <span class="hlt">Electron</span> Acoustic Waves in Dissipative <span class="hlt">Plasma</span> with Superthermal <span class="hlt">Electrons</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>El-Hanbaly, A. M.; El-Shewy, E. K.; Kassem, A. I.; Darweesh, H. F.</p> <p>2016-01-01</p> <p>The nonlinear properties of small amplitude <span class="hlt">electron</span>-acoustic ( EA) solitary and shock waves in a homogeneous system of unmagnetized collisionless <span class="hlt">plasma</span> consisted of a cold <span class="hlt">electron</span> fluid and superthermal hot <span class="hlt">electrons</span> obeying superthermal distribution, and stationary ions have been investigated. A reductive perturbation method was employed to obtain the Kadomstev-Petviashvili-Burgers (KP-Brugers) equation. Some solutions of physical interest are obtained. These solutions are related to soliton, monotonic and oscillatory shock waves and their behaviour are shown graphically. The formation of these solutions depends crucially on the value of the Burgers term and the <span class="hlt">plasma</span> parameters as well. By using the tangent hyperbolic (tanh) method, another interesting type of solution which is a combination between shock and soliton waves is obtained. The topology of phase portrait and potential diagram of the KP-Brugers equation is investigated.The advantage of using this method is that one can predict different classes of the travelling wave solutions according to different phase orbits. The obtained results may be helpful in better understanding of waves propagation in various space <span class="hlt">plasma</span> environments as well as in inertial confinement fusion laboratory <span class="hlt">plasmas</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20150009523','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20150009523"><span>Effect of <span class="hlt">Electron</span> Beam Irradiation on the Tensile Properties of Carbon Nanotubes <span class="hlt">Sheets</span> and Yarns</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Williams, Tiffany S.; Miller, Sandi G.; Baker, James S.; McCorkle, Linda S.; Meador, Michael A.</p> <p>2013-01-01</p> <p>Carbon nanotube <span class="hlt">sheets</span> and yarns were irradiated using <span class="hlt">electron</span> beam (e-beam) energy to determine the effect of irradiation dose on the tensile properties. Results showed that a slight change in tensile strength occurred after irradiating as-received CNT <span class="hlt">sheets</span> for 20 minutes, and a slight decrease in tensile strength as the irradiation time approached 90 minutes. On the other hand, the addition of small molecules to the CNT <span class="hlt">sheet</span> surface had a greater effect on the tensile properties of e-beam irradiated CNT <span class="hlt">sheets</span>. Some functionalized CNT <span class="hlt">sheets</span> displayed up to a 57% increase in tensile strength following 90 minutes of e-beam exposure. In addition, as-received CNT yarns showed a significant increase in tensile strength as the irradiation time increased.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_9");'>9</a></li> <li><a href="#" onclick='return showDiv("page_10");'>10</a></li> <li class="active"><span>11</span></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_11 --> <div id="page_12" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_10");'>10</a></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li class="active"><span>12</span></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="221"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2008AdSpR..41.1585T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2008AdSpR..41.1585T"><span><span class="hlt">Plasma</span> <span class="hlt">sheet</span> oscillations and their relation to substorm development: Cluster and double star TC1 case study</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Takada, T.; Nakamura, R.; Asano, Y.; Baumjohann, W.; Runov, A.; Volwerk, M.; Zhang, T. L.; Vörös, Z.; Keika, K.; Klecker, B.; Rème, H.; Lucek, E. A.; Carr, C.; Frey, H. U.</p> <p></p> <p>We examined two consecutive <span class="hlt">plasma</span> <span class="hlt">sheet</span> oscillation and dipolarization events observed by Cluster in the magnetotail, which are associated with a pseudo-breakup and a small substorm monitored by the IMAGE spacecraft. Energy input from the solar wind and an associated enhancement of the cross-tail current lead to current <span class="hlt">sheet</span> thinning and <span class="hlt">plasma</span> <span class="hlt">sheet</span> oscillations of 3 5 min periods, while the pseudo-breakups occur during the loading phase within a spatially limited area, accompanied by a localized dipolarization observed by DSP TC1 or GOES 12. That is, the so-called “growth phase” is a preferable condition for both pseudo-breakup and <span class="hlt">plasma</span> <span class="hlt">sheet</span> oscillations in the near-Earth magnetotail. One of the <span class="hlt">plasma</span> <span class="hlt">sheet</span> oscillation events occurs before the pseudo-breakup, whereas the other takes place after pseudo-breakup. Thus there is no causal relationship between the <span class="hlt">plasma</span> <span class="hlt">sheet</span> oscillation events and pseudo-breakup. As for the contribution to the subsequent small substorm, the onset of the small substorm took place where the preceding <span class="hlt">plasma</span> <span class="hlt">sheet</span> oscillations can reach the region.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016Ge%26Ae..56....8K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016Ge%26Ae..56....8K"><span>Electric and magnetic components of ballooning perturbations in the magnetotail <span class="hlt">plasma</span> <span class="hlt">sheet</span> before breakup</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kogai, T. G.; Golovchanskaya, I. V.; Kornilov, I. A.; Kornilova, T. A.; Fedorenko, Y. V.</p> <p>2016-01-01</p> <p>Using data from THEMIS spacecraft we investigated transverse to the magnetic field mutually perpendicular electric and magnetic components of ballooning type perturbations with periods 60-240 s, which are observed in the magnetospheric <span class="hlt">plasma</span> <span class="hlt">sheet</span> during the period preceding substorm onset. With applying Hilbert transform, we analyzed the phase relations between them. It is shown that the perturbations are dominated by radial electric and azimuthal magnetic (that is, toroidal) components which are usually in phase or out-of-phase. Along with them, approximately 2.5 times less intense azimuthal electric and radial magnetic components are present, which are more often phase-shifted by π/2. It is concluded that the observed perturbations are not a simple consequence of the development of <span class="hlt">plasma</span> <span class="hlt">sheet</span> ballooning instability, leading to the growth of strongly elongated along the magnetotail ballooning structures. It is pointed out that this conclusion is confirmed by simultaneous ground-based observations of magnetically conjugate auroral structures.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/22489953','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/22489953"><span>Laser-driven <span class="hlt">electron</span> acceleration in an inhomogeneous <span class="hlt">plasma</span> channel</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Zhang, Rong; Cheng, Li-Hong; Xue, Ju-Kui</p> <p>2015-12-15</p> <p>We study the laser-driven <span class="hlt">electron</span> acceleration in a transversely inhomogeneous <span class="hlt">plasma</span> channel. We find that, in inhomogeneous <span class="hlt">plasma</span> channel, the developing of instability for <span class="hlt">electron</span> acceleration and the <span class="hlt">electron</span> energy gain can be controlled by adjusting the laser polarization angle and inhomogeneity of <span class="hlt">plasma</span> channel. That is, we can short the accelerating length and enhance the energy gain in inhomogeneous <span class="hlt">plasma</span> channel by adjusting the laser polarization angle and inhomogeneity of the <span class="hlt">plasma</span> channel.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/15204439','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/15204439"><span>Activated FcgammaRII and signalling molecules revealed in rafts by ultra-structural observations of <span class="hlt">plasma</span>-membrane <span class="hlt">sheets</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Strzelecka-Kiliszek, Agnieszka; Korzeniowski, Marek; Kwiatkowska, Katarzyna; Mrozińska, Kazimiera; Sobota, Andrzej</p> <p>2004-01-01</p> <p>To reveal topography of FcgammaRII components of the receptor-signalling complex, large <span class="hlt">plasma</span>-membrane <span class="hlt">sheets</span> were obtained by cell cleavage and analysed by immuno-<span class="hlt">electron</span> microscopy. Non-activated FcgammaRII was dispersed in the plane of the <span class="hlt">plasma</span> membrane and only rarely was localized in the proximity of Lyn, an Src family tyrosine kinase, and CD55, a glycosylphosphatidylinositol-anchored protein. After FcgammaRII activation by cross-linking with antibodies, clusters of an <span class="hlt">electron</span>-dense material acquiring about 86% of FcgammaRII and reaching up to 300 nm in diameter were formed within 5 min. These structures also accommodated about 85% of Lyn and 63% of CD55 labels that were located in close vicinity of gold particles attributed to the cross-linked FcgammaRII . The <span class="hlt">electron</span>-dense structures were also abundant in tyrosine phosphorylated proteins. At their margins PIP2 was preferentially located. Based on a concentration of Lyn, CD55 and activated FcgammaRII , the <span class="hlt">electron</span>-dense structures seem to reflect coalescent membrane rafts.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/20702248','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/20702248"><span>Runaway <span class="hlt">electrons</span> in a fully and partially ionized nonideal <span class="hlt">plasma</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Ramazanov, T.S.; Turekhanova, K.M.</p> <p>2005-10-01</p> <p>This paper reports on a study of <span class="hlt">electron</span> runaway for a nonideal <span class="hlt">plasma</span> in an external electric field. Based on pseudopotential models of nonideal fully and partially ionized <span class="hlt">plasmas</span>, the friction force was derived as a function of <span class="hlt">electron</span> velocities. Dependences of the <span class="hlt">electron</span> free path on <span class="hlt">plasma</span> density and nonideality parameters were obtained. The impact of the relative number of runaway <span class="hlt">electrons</span> on their velocity and temperature was considered for classical and semiclassical models of a nonideal <span class="hlt">plasma</span>. It has been shown that for the defined intervals of the coupled <span class="hlt">plasma</span> parameter, the difference between the relative numbers of runaway <span class="hlt">electron</span> values is essential for various <span class="hlt">plasma</span> models.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/12570496','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/12570496"><span>Measurement of the current <span class="hlt">sheet</span> during magnetic reconnection in a toroidal <span class="hlt">plasma</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Crocker, N A; Fiksel, G; Prager, S C; Sarff, J S</p> <p>2003-01-24</p> <p>The current and magnetic-field fluctuations associated with magnetic-field-line reconnection have been measured in the reversed field pinch <span class="hlt">plasma</span> configuration. The current <span class="hlt">sheet</span> resulting from this reconnection has been measured. The current layer is radially broad, comparable to a magnetic-island width, as may be expected from current transport along magnetic-field lines. It is much larger than that predicted by resistive MHD for linear tearing modes and larger than prediction from two-fluid linear theory.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1998GeoRL..25.3067L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1998GeoRL..25.3067L"><span>Generation of large <span class="hlt">sheet</span>-like ionospheric <span class="hlt">plasma</span> irregularities at Arecibo</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Lee, M. C.; Riddolls, R. J.; Burke, W. J.; Sulzer, M. P.; Kuo, S. P.; Klien, E. M. C.</p> <p></p> <p>Large-scale ionospheric <span class="hlt">plasma</span> irregularities, generated by O-mode heater waves at Arecibo, are shown for the first time to have “<span class="hlt">sheet</span>-like” structures. The irregularities are aligned with the magnetic meridional plane and have scale sizes ranging from a few hundred meters to a few kilometers. This interpretation is based on detailed considerations of sequential measurements of radar backscatter power, the controlling magnetic field geometry, and the deduced E × B <span class="hlt">plasma</span> drift. The alignment of O-mode-generated irregularities with the magnetic meridional plane, and their disappearance during X-mode heating intervals are consistent with predictions of the thermal filamentation instability model.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19870066947&hterms=plasma+Composition+Experiment&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3Dplasma%2BComposition%2BExperiment','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19870066947&hterms=plasma+Composition+Experiment&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3Dplasma%2BComposition%2BExperiment"><span><span class="hlt">Plasma</span> <span class="hlt">sheet</span> ion composition at various levels of geomagnetic and solar activity</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Lennartsson, W.</p> <p>1987-01-01</p> <p>The data obtained in the earth's <span class="hlt">plasma</span> <span class="hlt">sheet</span> by the <span class="hlt">Plasma</span> Composition Experiment on the ISEE-1 spacecraft are briefly reexamined. The data are shown in the form of statistically averaged bulk parameters for the four major ions H(+), He(2+), He(+), and O(+) to illustrate the apparent mixture of solar and terrestrial ions, a mixture that varies with geomagnetic and other conditions. Some major differences in the statistical properties of different ions, which may have a bearing on the physics of the solar wind-magnetosphere interaction, are highlighted.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1987PhyS...36..367L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1987PhyS...36..367L"><span><span class="hlt">Plasma</span> <span class="hlt">sheet</span> ion composition at various levels of geomagnetic and solar activity</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Lennartsson, W.</p> <p>1987-08-01</p> <p>The data obtained in the earth's <span class="hlt">plasma</span> <span class="hlt">sheet</span> by the <span class="hlt">Plasma</span> Composition Experiment on the ISEE-1 spacecraft are briefly reexamined. The data are shown in the form of statistically averaged bulk parameters for the four major ions H(+), He(2+), He(+), and O(+) to illustrate the apparent mixture of solar and terrestrial ions, a mixture that varies with geomagnetic and other conditions. Some major differences in the statistical properties of different ions, which may have a bearing on the physics of the solar wind-magnetosphere interaction, are highlighted.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2011ApPhL..98l3107T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011ApPhL..98l3107T"><span><span class="hlt">Electron</span> field emission enhancement of carbon nanowalls by <span class="hlt">plasma</span> surface nitridation</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Takeuchi, Wakana; Kondo, Hiroki; Obayashi, Tomomi; Hiramatsu, Mineo; Hori, Masaru</p> <p>2011-03-01</p> <p>Carbon nanowalls (CNWs) are two-dimensional carbon nanostructures consisting of stacked graphene <span class="hlt">sheets</span> standing vertically on the substrate. The sharp edges of CNWs provide us with opportunities for applications as <span class="hlt">electron</span> field emitter arrays. The effects of nitrogen <span class="hlt">plasma</span> (NP) treatment on the surface of CNWs have been investigated in order to improve the <span class="hlt">electron</span> field emission properties. The <span class="hlt">electron</span> emission current from the edges of CNWs was drastically increased by the NP treatment. Morphological and chemical changes in the CNWs after the NP treatment were characterized using scanning <span class="hlt">electron</span> microscopy, Raman spectroscopy, and x-ray photoelectron spectroscopy.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19930072240&hterms=IRM&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3DIRM','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19930072240&hterms=IRM&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3DIRM"><span>Characteristics of ion flow in the quiet state of the inner <span class="hlt">plasma</span> <span class="hlt">sheet</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Angelopoulos, V.; Kennel, C. F.; Coroniti, F. V.; Pellat, R.; Spence, H. E.; Kivelson, M. G.; Walker, R. J.; Baumjohann, W.; Feldman, W. C.; Gosling, J. T.</p> <p>1993-01-01</p> <p>We use AMPTE/IRM and ISEE 2 data to study the properties of the high beta <span class="hlt">plasma</span> <span class="hlt">sheet</span>, the inner <span class="hlt">plasma</span> <span class="hlt">sheet</span> (IPS). Bursty bulk flows (BBFs) are excised from the two databases, and the average flow pattern in the non-BBF (quiet) IPS is constructed. At local midnight this ensemble-average flow is predominantly duskward; closer to the flanks it is mostly earthward. The flow pattern agrees qualitatively with calculations based on the Tsyganenko (1987) model (T87), where the earthward flow is due to the ensemble-average cross tail electric field and the duskward flow is the diamagnetic drift due to an inward pressure gradient. The IPS is on the average in pressure equilibrium with the lobes. Because of its large variance the average flow does not represent the instantaneous flow field. Case studies also show that the non-BBF flow is highly irregular and inherently unsteady, a reason why earthward convection can avoid a pressure balance inconsistency with the lobes. The ensemble distribution of velocities is a fundamental observable of the quiet <span class="hlt">plasma</span> <span class="hlt">sheet</span> flow field.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016PlPhR..42..388M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016PlPhR..42..388M"><span>Formation and evolution of flapping and ballooning waves in magnetospheric <span class="hlt">plasma</span> <span class="hlt">sheet</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ma, J. Z. G.; Hirose, A.</p> <p>2016-05-01</p> <p>By adopting Lembége & Pellat's 2D <span class="hlt">plasma-sheet</span> model, we investigate the flankward flapping motion and Sunward ballooning propagation driven by an external source (e.g., magnetic reconnection) produced initially at the <span class="hlt">sheet</span> center. Within the ideal MHD framework, we adopt the WKB approximation to obtain the Taylor-Goldstein equation of magnetic perturbations. Fourier spectral method and Runge-Kutta method are employed in numerical simulations, respectively, under the flapping and ballooning conditions. Studies expose that the magnetic shears in the <span class="hlt">sheet</span> are responsible for the flapping waves, while the magnetic curvature and the <span class="hlt">plasma</span> gradient are responsible for the ballooning waves. In addition, the flapping motion has three phases in its temporal development: fast damping phase, slow recovery phase, and quasi-stabilized phase; it is also characterized by two patterns in space: propagating wave pattern and standing wave pattern. Moreover, the ballooning modes are gradually damped toward the Earth, with a wavelength in a scale size of magnetic curvature or <span class="hlt">plasma</span> inhomogeneity, only 1-7% of the flapping one; the envelops of the ballooning waves are similar to that of the observed bursty bulk flows moving toward the Earth.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015JGRA..120.4736P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015JGRA..120.4736P"><span>Polytropic index of central <span class="hlt">plasma</span> <span class="hlt">sheet</span> ions based on MHD Bernoulli integral</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Pang, Xuexia; Cao, Jinbin; Liu, Wenlong; Ma, Yuduan; Lu, Haoyu; Yang, Junying; Li, Liuyuan; Liu, Xu; Wang, Jing; Wang, Tieyan; Yu, Jiang</p> <p>2015-06-01</p> <p>This paper uses the data of Cluster from 2001 to 2009 to study the polytropic processes of central <span class="hlt">plasma</span> <span class="hlt">sheet</span> (CPS) ions. We first adopt the approach of MHD Bernoulli integral (MBI) to identify homogeneous streamflow tubes (quasi-invariant MBI regions) and then calculate the polytropic index of ions for those streamflow tubes whose outward electromagnetic energy ratios δ < 0.05. The central <span class="hlt">plasma</span> <span class="hlt">sheet</span> is actually a complicated system, which comprises many streamflow tubes with different polytropic relations and the transition layers in between. The polytropic indexes of the CPS ions range from 0.1 to 1.8 and have a quasi-Gaussian distribution. The median polytropic index is 0.93 for AE < 200 nT and 0.91 for AE ≥ 200 nT. Thus, there is no obvious difference between the polytropic indexes of the quiet time and the substorm time CPS ions, which suggests that the thinning and thickening processes of <span class="hlt">plasma</span> <span class="hlt">sheet</span> during substorm times do not change obviously the polytropic relation of the CPS ions. The statistical analysis using different δ (δ < 0.05, 0.025, and 0.01) shows that the outward emission of electromagnetic energy is an effective cooling mechanism and can make the polytropic index to decrease and shift toward isobaric. It is inferred that the CPS ions as a whole much likely behave in a way between isobaric and isothermal.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015TESS....120310M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015TESS....120310M"><span>Hinode/XRT Measurements of Turbulent Velocities in Flare <span class="hlt">Plasma</span> <span class="hlt">Sheets</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>McKenzie, David; Freed, Michael</p> <p>2015-04-01</p> <p>The turbulent, dynamic motions that we observe in the hot <span class="hlt">plasma</span> surrounding current <span class="hlt">sheets</span> very likely distort the embedded magnetic fields, resulting in reduced length scales and locally augmented resistivities. These conditions may help to accelerate and/or prolong the reconnection in solar flares. Although we cannot as yet measure directly the magnetic fields in the corona, the velocity fields within the flare <span class="hlt">plasma</span> <span class="hlt">sheets</span> provide a means to study the conditions that control the spatial and temporal scales of reconnection, in the locations and at the times that are relevant to structuring the magnetic fields.The <span class="hlt">plasma</span> <span class="hlt">sheets</span> are observable in many flares in soft X-ray and EUV wavelengths, due to their high temperatures. For two recent flares observed with the Hinode X-Ray Telescope (XRT), we have analyzed the velocity fields with a local correlation tracking technique, and compared to measurements from the Solar Dynamics Observatory Atmospheric Imaging Assembly (SDO/AIA).This work is supported by NASA under contract NNM07AB07C with the Smithsonian Astrophysical Observatory, and by grant NNX14AD43G.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19950011848&hterms=IRM&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3DIRM','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19950011848&hterms=IRM&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3DIRM"><span>Bursty bulk flows in the inner central <span class="hlt">plasma</span> <span class="hlt">sheet</span>: An effective means of earthward transport in the magnetotail</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Angelopoulos, Vassilis; Kennel, Charles F.; Coroniti, F. V.; Pellat, R.; Kivelson, M. G.; Walker, R. J.; Baumjohann, W.; Paschmann, G.; Luhr, H.</p> <p>1992-01-01</p> <p>High speed flows in the Earth's Inner Central <span class="hlt">Plasma</span> <span class="hlt">Sheet</span> (ICPS) occur during enhanced flow intervals that have been termed Bursty Bulk Flow (BBF) events. The importance of different flow magnitude samples for Earthward transport in the ICPS are statistically evaluated and several representative BBF's and their relevance to Earthward transport are discussed. The selection of BBF's is automated in a database and they are shown to be responsible for most of the Earthward transport that occurs within the ICPS. The BBF related transport is compared to the transport measured within the entire <span class="hlt">plasma</span> <span class="hlt">sheet</span> during the 1985 AMPTE/IRM crossings of the magnetotail. The results show that BBF's last only a small fraction of the time in the <span class="hlt">plasma</span> <span class="hlt">sheet</span> but can account for several tens of percent of the Earthward particle and energy transfer and possibly all of the Earthward magnetic flux transfer in the <span class="hlt">plasma</span> <span class="hlt">sheet</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013AGUFMSM11B2113B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013AGUFMSM11B2113B"><span>Statistics of <span class="hlt">Plasma</span> Properties in Different Magnetotail <span class="hlt">Plasma</span> <span class="hlt">Sheet</span> Regions and their Dependence on Magnetic Activity and Solar Wind Driving Conditions, using the ECLAT Dataset</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Boakes, P. D.; Nakamura, R.; Volwerk, M.; Milan, S. E.</p> <p>2013-12-01</p> <p>As part of the European Seventh Framework Programme project 'European Cluster Assimilation Technology (ECLAT)', we have developed a comprehensive list of <span class="hlt">plasma</span> region encountered in the Earth's magnetotail (X<-8 RE, │Y│<15 RE) by each of the four ESA Cluster spacecraft. The regions identified are the inner <span class="hlt">plasma</span> <span class="hlt">sheet</span>, outer <span class="hlt">plasma</span> <span class="hlt">sheet</span>, boundary layer, magnetospheric lobes, as well as crossings of the neutral <span class="hlt">sheet</span>. Each <span class="hlt">plasma</span> region encountered is recorded with an entry and exit time and averaged parameters, such as magnetic field, <span class="hlt">plasma</span>, and velocity, describing each region. In this presentation, we statistically investigate the spatial characteristics of the magnetotail region parameters and their dependence on the magnetic/solar wind conditions, for each type of <span class="hlt">plasma</span> region identified in the ECLAT database.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19850051326&hterms=Plasma+doppler&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3DPlasma%2Bdoppler','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19850051326&hterms=Plasma+doppler&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3DPlasma%2Bdoppler"><span>The downshift of <span class="hlt">electron</span> <span class="hlt">plasma</span> oscillations in the <span class="hlt">electron</span> foreshock region</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Fuselier, S. A.; Gurnett, D. A.; Fitzenreiter, R. J.</p> <p>1985-01-01</p> <p><span class="hlt">Electron</span> <span class="hlt">plasma</span> oscillations in the earth's <span class="hlt">electron</span> foreshock region are observed to shift above and below the local <span class="hlt">electron</span> <span class="hlt">plasma</span> frequency. As <span class="hlt">plasma</span> oscillations shift downward from the <span class="hlt">plasma</span> frequency, their bandwidth increases and their wavelength decreases. Observations of <span class="hlt">plasma</span> oscillations well below the <span class="hlt">plasma</span> frequency are correlated with times when ISEE 1 is far downstream of the <span class="hlt">electron</span> foreshock boundary. Although wavelengths of <span class="hlt">plasma</span> oscillations below the <span class="hlt">plasma</span> frequency satisfy k x lambda-De approximately 1 the Doppler shift due to the motion of the solar wind is not sufficient to produce the observed frequency shifts. A beam-<span class="hlt">plasma</span> interaction with beam velocities on the order of the <span class="hlt">electron</span> thermal velocity is suggested as an explanation for <span class="hlt">plasma</span> oscillations above and below the <span class="hlt">plasma</span> frequency. Frequency, bandwidth, and wavelength changes predicted from the beam-<span class="hlt">plasma</span> interaction are in good agreement with the observed characteristics of <span class="hlt">plasma</span> oscillations in the foreshock region.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20110015845','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20110015845"><span>Effect of Inductive Coil Geometry and Current <span class="hlt">Sheet</span> Trajectory of a Conical Theta Pinch Pulsed Inductive <span class="hlt">Plasma</span> Accelerator</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Hallock, Ashley K.; Polzin, Kurt A.; Bonds, Kevin W.; Emsellem, Gregory D.</p> <p>2011-01-01</p> <p>Results are presented demonstrating the e ect of inductive coil geometry and current <span class="hlt">sheet</span> trajectory on the exhaust velocity of propellant in conical theta pinch pulsed induc- tive <span class="hlt">plasma</span> accelerators. The electromagnetic coupling between the inductive coil of the accelerator and a <span class="hlt">plasma</span> current <span class="hlt">sheet</span> is simulated, substituting a conical copper frustum for the <span class="hlt">plasma</span>. The variation of system inductance as a function of <span class="hlt">plasma</span> position is obtained by displacing the simulated current <span class="hlt">sheet</span> from the coil while measuring the total inductance of the coil. Four coils of differing geometries were employed, and the total inductance of each coil was measured as a function of the axial displacement of two sep- arate copper frusta both having the same cone angle and length as the coil but with one compressed to a smaller size relative to the coil. The measured relationship between total coil inductance and current <span class="hlt">sheet</span> position closes a dynamical circuit model that is used to calculate the resulting current <span class="hlt">sheet</span> velocity for various coil and current <span class="hlt">sheet</span> con gura- tions. The results of this model, which neglects the pinching contribution to thrust, radial propellant con nement, and plume divergence, indicate that in a conical theta pinch ge- ometry current <span class="hlt">sheet</span> pinching is detrimental to thruster performance, reducing the kinetic energy of the exhausting propellant by up to 50% (at the upper bound for the parameter range of the study). The decrease in exhaust velocity was larger for coils and simulated current <span class="hlt">sheets</span> of smaller half cone angles. An upper bound for the pinching contribution to thrust is estimated for typical operating parameters. Measurements of coil inductance for three di erent current <span class="hlt">sheet</span> pinching conditions are used to estimate the magnetic pressure as a function of current <span class="hlt">sheet</span> radial compression. The gas-dynamic contribution to axial acceleration is also estimated and shown to not compensate for the decrease in axial electromagnetic acceleration</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19850000068&hterms=silicone&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D60%26Ntt%3Dsilicone','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19850000068&hterms=silicone&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D60%26Ntt%3Dsilicone"><span>Silicone Coating on Polyimide <span class="hlt">Sheet</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Park, J. J.</p> <p>1985-01-01</p> <p>Silicone coatings applied to polyimide <span class="hlt">sheeting</span> for variety of space-related applications. Coatings intended to protect flexible substrates of solar-cell blankets from degradation by oxygen atoms, <span class="hlt">electrons</span>, <span class="hlt">plasmas</span>, and ultraviolet light in low Earth orbit and outer space. Since coatings are flexible, generally useful in forming flexible laminates or protective layers on polyimide-<span class="hlt">sheet</span> products.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017PhPl...24c2106H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017PhPl...24c2106H"><span>Magnetosonic wave in pair-ion <span class="hlt">electron</span> collisional <span class="hlt">plasmas</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Hussain, S.; Hasnain, H.</p> <p>2017-03-01</p> <p>Low frequency magnetosonic waves in positive and negative ions of equal mass and opposite charges in the presence of <span class="hlt">electrons</span> in collisional <span class="hlt">plasmas</span> are studied. The collisions of ions and <span class="hlt">electrons</span> with neutrals are taken into account. The nonlinearities in the <span class="hlt">plasma</span> system arise due to ion and <span class="hlt">electrons</span> flux, Lorentz forces, and <span class="hlt">plasma</span> current densities. The reductive perturbation method is applied to derive the Damped Korteweg de Vries (DKdV) equation. The time dependent solution of DKdV is presented. The effects of variations of different <span class="hlt">plasma</span> parameters on propagation characteristics of magnetosonic waves in pair-ion <span class="hlt">electron</span> <span class="hlt">plasma</span> in the context of laboratory <span class="hlt">plasmas</span> are discussed.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_10");'>10</a></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li class="active"><span>12</span></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_12 --> <div id="page_13" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li class="active"><span>13</span></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="241"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013AGUFMSH51C2116L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013AGUFMSH51C2116L"><span>Transition in <span class="hlt">Electron</span> Physics of Magnetic Reconnection in Weakly Collisional <span class="hlt">Plasma</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Le, A.; Roytershteyn, V.; Karimabadi, H.; Daughton, W. S.; Egedal, J.; Forest, C.</p> <p>2013-12-01</p> <p>Using self-consistent fully kinetic simulations with a Monte-Carlo treatment of the Coulomb collision operator, we explore the transition between collisional and kinetic regimes of magnetic reconnection in high-Lundquist-number current <span class="hlt">sheets</span>. Recent research in collisionless reconnection has shown that <span class="hlt">electron</span> kinetic physics plays a key role in the evolution. Large-scale <span class="hlt">electron</span> current <span class="hlt">sheets</span> may form, leading to secondary island formation and turbulent flux rope interactions in 3D. The new collisional simulations demonstrate how increasing collisionality modifies or eliminates these <span class="hlt">electron</span> structures in the kinetic regimes. Additional basic questions that are addressed include how the reconnection rate and the release of magnetic energy into <span class="hlt">electrons</span> and ions vary with collisionality. The numerical study provides insight into reconnection in dense regions of the solar corona, the solar wind, and upcoming laboratory experiments at MRX (Princeton) and MPDX (UW-Madison). The implications of these results for studies of turbulence dissipation in weakly collisional <span class="hlt">plasmas</span> are discussed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014APS..DPPNP8058B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014APS..DPPNP8058B"><span>Probing Runaway <span class="hlt">Electrons</span> with Nanoparticle <span class="hlt">Plasma</span> Jet</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Bogatu, I. N.; Thompson, J. R.; Galkin, S. A.; Kim, J. S.</p> <p>2014-10-01</p> <p>The injection of C60/C nanoparticle <span class="hlt">plasma</span> jet (NPPJ) into tokamak <span class="hlt">plasma</span> during a major disruption has the potential to probe the runaway <span class="hlt">electrons</span> (REs) during different phases of their dynamics and diagnose them through spectroscopy of C ions visible/UV lines. A C60/C NPPJ of ~75 mg, high-density (>1023 m-3), hyper-velocity (>4 km/s), and uniquely fast response-to-delivery time (~1 ms) has been demonstrated on a test bed. It can rapidly and deeply deliver enough mass to increase <span class="hlt">electron</span> density to ~2.4 × 1021 m-3, ~60 times larger than typical DIII-D pre-disruption value. We will present the results of our investigations on: 1) C60 fragmentation and gradual release of C atoms along C60 NPPJ penetration path through the RE carrying residual cold <span class="hlt">plasma</span>, 2) estimation of photon emissivity coefficient for the lines of the C ions, and 3) simulation of C60/C PJ penetration to the RE beam location in equivalent conditions to the characteristic ~1 T B-field of DIII-D. The capabilities of this injection technique provide a unique possibility in understanding and controlling the RE beam, which is a critical problem for ITER. Work supported by US DOE DE-SC0011864 Grant.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2008AdSpR..41.1643H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2008AdSpR..41.1643H"><span><span class="hlt">Electron</span> temperature anisotropy effects on tearing mode in ion-scale current <span class="hlt">sheets</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Haijima, K.; Tanaka, K. G.; Fujimoto, M.; Shinohara, I.</p> <p></p> <p>Recent two-dimensional (2-D) particle-in-cell (PIC) simulations have shown that there is a critical thickness of a current <span class="hlt">sheet</span>, above which no significant saturation amplitude of the 2-D tearing (TI) mode can be expected. Here, we have introduced the initial <span class="hlt">electron</span> temperature anisotropy (αe0 = Te⊥/Te|| > 1), which is known to raise significantly the linear growth rates, and inspected if αe0 > 1 can change the saturation level of the TI in a super-critical current <span class="hlt">sheet</span>. Varying αe0 and D (D: the current <span class="hlt">sheet</span> half-thickness) systematically, we have found that while αe0 boosts up the linear growth rate in both sub- and super-critical current <span class="hlt">sheets</span>, macroscopic effects are obtained only in sub-critical current <span class="hlt">sheets</span>, that is, energy transfer from the fastest growing short wavelength modes to longer wavelength modes are available only in the sub-critical regime. Since the critical thickness is a fraction of the ion inertial length, the tearing mode assisted by the <span class="hlt">electron</span> temperature anisotropy alone, despite its significant boost in the linear growth rate, cannot be the agent for reconnection triggering in a current <span class="hlt">sheet</span> of ion-scale thickness.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4431294','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4431294"><span>Detection of Steel Fatigue Cracks with Strain Sensing <span class="hlt">Sheets</span> Based on Large Area <span class="hlt">Electronics</span></span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Yao, Yao; Glisic, Branko</p> <p>2015-01-01</p> <p>Reliable early-stage damage detection requires continuous monitoring over large areas of structure, and with sensors of high spatial resolution. Technologies based on Large Area <span class="hlt">Electronics</span> (LAE) can enable direct sensing and can be scaled to the level required for Structural Health Monitoring (SHM) of civil structures and infrastructure. Sensing <span class="hlt">sheets</span> based on LAE contain dense arrangements of thin-film strain sensors, associated <span class="hlt">electronics</span> and various control circuits deposited and integrated on a flexible polyimide substrate that can cover large areas of structures. This paper presents the development stage of a prototype strain sensing <span class="hlt">sheet</span> based on LAE for crack detection and localization. Two types of sensing-<span class="hlt">sheet</span> arrangements with size 6 × 6 inch (152 × 152 mm) were designed and manufactured, one with a very dense arrangement of sensors and the other with a less dense arrangement of sensors. The sensing <span class="hlt">sheets</span> were bonded to steel plates, which had a notch on the boundary, so the fatigue cracks could be generated under cyclic loading. The sensors within the sensing <span class="hlt">sheet</span> that were close to the notch tip successfully detected the initialization of fatigue crack and localized the damage on the plate. The sensors that were away from the crack successfully detected the propagation of fatigue cracks based on the time history of the measured strain. The results of the tests have validated the general principles of the proposed sensing <span class="hlt">sheets</span> for crack detection and identified advantages and challenges of the two tested designs. PMID:25853407</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2008JGRA..113.7S35K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2008JGRA..113.7S35K"><span>Response of the inner magnetosphere and the <span class="hlt">plasma</span> <span class="hlt">sheet</span> to a sudden impulse</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Keika, K.; Nakamura, R.; Baumjohann, W.; Runov, A.; Takada, T.; Volwerk, M.; Zhang, T. L.; Klecker, B.; Lucek, E. A.; Carr, C.; RèMe, H.; Dandouras, I.; André, M.; Frey, H.</p> <p>2008-07-01</p> <p>The passage of an interplanetary shock caused a sudden compression of the magnetosphere between 0900 UT and 0915 UT on 24 August 2005. An estimate of the shock normal from solar wind data obtained by Geotail upstream of the bow shock indicates symmetric compression with respect to the noon-midnight meridian. Compression-related disturbances of the magnetic and electric field and <span class="hlt">plasma</span> motion were observed by Double Star Program (DSP) Tan Ce 1 (TC1) and Tan Ce 2 (TC2) in the inner magnetosphere and by the Cluster spacecraft in the dawnside <span class="hlt">plasma</span> <span class="hlt">sheet</span>. DSP/TC1 and TC2 observations suggest that the disturbances in the inner magnetosphere are propagating from the dayside magnetopause. Cluster S/C 4 observations indicate that the front normal of the disturbances in the dawnside <span class="hlt">plasma</span> <span class="hlt">sheet</span> is ϕ ˜ 180° at 0902:50 UT and ϕ = 107° at 0904:34 UT, where ϕ is the longitude in GSM coordinates, if we assume that the measured electric field is on the front plane and the normal lies on the X-Y plane. The timing analysis applied to magnetic field data from the four Cluster spacecraft independently gives a front normal, which is calculated to be ϕ = 131° at about 0904:20 UT. Shock-associated magnetic and electric field disturbances propagating from both the dayside and flank magnetopauses are detected in the <span class="hlt">plasma</span> <span class="hlt">sheet</span>; the latter makes the dominant contribution. Substorms are, however, not triggered at the passage of the disturbances.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/22093525','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/22093525"><span><span class="hlt">Electron</span>-helium scattering in Debye <span class="hlt">plasmas</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Zammit, Mark C.; Fursa, Dmitry V.; Bray, Igor; Janev, R. K.</p> <p>2011-11-15</p> <p><span class="hlt">Electron</span>-helium scattering in weakly coupled hot-dense (Debye) <span class="hlt">plasma</span> has been investigated using the convergent close-coupling method. The Yukawa-type Debye-Hueckel potential has been used to describe <span class="hlt">plasma</span> Coulomb screening effects. Benchmark results are presented for momentum transfer cross sections, excitation, ionization, and total cross sections for scattering from the ground and metastable states of helium. Calculations cover the entire energy range up to 1000 eV for the no screening case and various Debye lengths (5-100 a{sub 0}). We find that as the screening interaction increases, the excitation and total cross sections decrease, while the total ionization cross sections increase.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/874126','DOE-PATENT-XML'); return false;" href="http://www.osti.gov/scitech/servlets/purl/874126"><span><span class="hlt">Plasma</span> treatment for producing <span class="hlt">electron</span> emitters</span></a></p> <p><a target="_blank" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Coates, Don Mayo; Walter, Kevin Carl</p> <p>2001-01-01</p> <p><span class="hlt">Plasma</span> treatment for producing carbonaceous field emission <span class="hlt">electron</span> emitters is disclosed. A <span class="hlt">plasma</span> of ions is generated in a closed chamber and used to surround the exposed surface of a carbonaceous material. A voltage is applied to an electrode that is in contact with the carbonaceous material. This voltage has a negative potential relative to a second electrode in the chamber and serves to accelerate the ions toward the carbonaceous material and provide an ion energy sufficient to etch the exposed surface of the carbonaceous material but not sufficient to result in the implantation of the ions within the carbonaceous material. Preferably, the ions used are those of an inert gas or an inert gas with a small amount of added nitrogen.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016GeoRL..4311484F','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016GeoRL..4311484F"><span>Drift paths of ions composing multiple-nose spectral structures near the inner edge of the <span class="hlt">plasma</span> <span class="hlt">sheet</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ferradas, C. P.; Zhang, J.-C.; Spence, H. E.; Kistler, L. M.; Larsen, B. A.; Reeves, G.; Skoug, R.; Funsten, H.</p> <p>2016-11-01</p> <p>We present a case study of the H+, He+, and O+ multiple-nose structures observed by the Helium, Oxygen, Proton, and <span class="hlt">Electron</span> instrument on board Van Allen Probe A over one complete orbit on 28 September 2013. Nose structures are observed near the inner edge of the <span class="hlt">plasma</span> <span class="hlt">sheet</span> and constitute the signatures of ion drift in the highly dynamic environment of the inner magnetosphere. We find that the multiple noses are intrinsically associated with variations in the solar wind. Backward ion drift path tracings show new details of the drift trajectories of these ions; i.e., multiple noses are formed by ions with a short drift time from the assumed source location to the inner region and whose trajectories (1) encircle the Earth different number of times or (2) encircle the Earth equal number of times but with different drift time, before reaching the observation site.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/5299827','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/5299827"><span>Dynamics of runaway <span class="hlt">electrons</span> in magnetized <span class="hlt">plasmas</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Moghaddam-Taaheri, E.</p> <p>1986-01-01</p> <p>The evolution of a runaway <span class="hlt">electron</span> tail driven by a subcritical dc electric field in a magnetized <span class="hlt">plasma</span> is studied numerically using a quasi-linear numerical code (2-D in v- and k-space) based on the Ritz-Galerkin method and finite elements. Three different regimes in the evolution of the runaway tail depending on the strength of the dc electric field and the ratio of <span class="hlt">plasma</span> to gyrofrequency, were found. The tail can be (a) stable and the <span class="hlt">electrons</span> are accelerated to large parallel velocities, (b) unstable to the Cerenkov resonance due to the formation of a positive slope on the runaway tail, (c) unstable to the anomalous Doppler resonance instability driven by the large velocity anisotropy in the tail. Once an instability is triggered (Cerenkov or anomalous Doppler resonance) the tail relaxes into an isotropic distribution resulting in less acceleration. The synchrotron emission of the runaway <span class="hlt">electrons</span> shows large enhancement in the radiation level at the high-frequency end of the spectrum during the pitch-angle scattering of the fast particles. The results are relevant to recent experimental data from the Princeton Large Torus (PLT) during current-drive experiments and to the microwave bursts observed during solar flares.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015SPIE.9435E..0GY','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015SPIE.9435E..0GY"><span>Sensing <span class="hlt">sheets</span> based on large area <span class="hlt">electronics</span> for fatigue crack detection</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Yao, Yao; Glisic, Branko</p> <p>2015-03-01</p> <p>Reliable early-stage damage detection requires continuous structural health monitoring (SHM) over large areas of structure, and with high spatial resolution of sensors. This paper presents the development stage of prototype strain sensing <span class="hlt">sheets</span> based on Large Area <span class="hlt">Electronics</span> (LAE), in which thin-film strain gauges and control circuits are integrated on the flexible <span class="hlt">electronics</span> and deposited on a polyimide <span class="hlt">sheet</span> that can cover large areas. These sensing <span class="hlt">sheets</span> were applied for fatigue crack detection on small-scale steel plates. Two types of sensing-<span class="hlt">sheet</span> interconnects were designed and manufactured, and dense arrays of strain gauge sensors were assembled onto the interconnects. In total, four (two for each design type) strain sensing <span class="hlt">sheets</span> were created and tested, which were sensitive to strain at virtually every point over the whole sensing <span class="hlt">sheet</span> area. The sensing <span class="hlt">sheets</span> were bonded to small-scale steel plates, which had a notch on the boundary so that fatigue cracks could be generated under cyclic loading. The fatigue tests were carried out at the Carleton Laboratory of Columbia University, and the steel plates were attached through a fixture to the loading machine that applied cyclic fatigue load. Fatigue cracks then occurred and propagated across the steel plates, leading to the failure of these test samples. The strain sensor that was close to the notch successfully detected the initialization of fatigue crack and localized the damage on the plate. The strain sensor that was away from the crack successfully detected the propagation of fatigue crack based on the time history of measured strain. Overall, the results of the fatigue tests validated general principles of the strain sensing <span class="hlt">sheets</span> for crack detection.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/1048437','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/1048437"><span><span class="hlt">Electron</span> Recombination in a Dense Hydrogen <span class="hlt">Plasma</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Jana, M.R.; Johnstone, C.; Kobilarcik, T.; Koizumi, G.M.; Moretti, A.; Popovic, M.; Tollestrup, A.V.; Yonehara, K.; Leonova, M.A.; Schwarz, T.A.; Chung, M.; /Unlisted /IIT, Chicago /Fermilab /MUONS Inc., Batavia /Turin Polytechnic</p> <p>2012-05-01</p> <p>A high pressure hydrogen gas filled RF cavity was subjected to an intense proton beam to study the evolution of the beam induced <span class="hlt">plasma</span> inside the cavity. Varying beam intensities, gas pressures and electric fields were tested. Beam induced ionized <span class="hlt">electrons</span> load the cavity, thereby decreasing the accelerating gradient. The extent and duration of this degradation has been measured. A model of the recombination between ionized <span class="hlt">electrons</span> and ions is presented, with the intent of producing a baseline for the physics inside such a cavity used in a muon accelerator. Analysis of the data taken during the summer of 2011 shows that self recombination takes place in pure hydrogen gas. The decay of the number of <span class="hlt">electrons</span> in the cavity once the beam is turned off indicates self recombination rather than attachment to electronegative dopants or impurities. The cross section of <span class="hlt">electron</span> recombination grows for larger clusters of hydrogen and so at the equilibrium of <span class="hlt">electron</span> production and recombination in the cavity, processes involving H{sub 5}{sup +} or larger clusters must be taking place. The measured recombination rates during this time match or exceed the analytic predicted values. The accelerating gradient in the cavity recovers fully in time for the next beam pulse of a muon collider. Exactly what the recombination rate is and how much the gradient degrades during the 60 ns muon collider beam pulse will be extrapolated from data taken during the spring of 2012.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/pages/biblio/1305900-electrostatic-gyrokinetic-electron-fully-kinetic-ion-simulation-lower-hybrid-drift-instability-harris-current-sheet','SCIGOV-DOEP'); return false;" href="https://www.osti.gov/pages/biblio/1305900-electrostatic-gyrokinetic-electron-fully-kinetic-ion-simulation-lower-hybrid-drift-instability-harris-current-sheet"><span>3D electrostatic gyrokinetic <span class="hlt">electron</span> and fully kinetic ion simulation of lower-hybrid drift instability of Harris current <span class="hlt">sheet</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/pages">DOE PAGES</a></p> <p>Wang, Zhenyu; Lin, Yu; Wang, Xueyi; ...</p> <p>2016-07-07</p> <p>The eigenmode stability properties of three-dimensional lower-hybrid-drift-instabilities (LHDI) in a Harris current <span class="hlt">sheet</span> with a small but finite guide magnetic field have been systematically studied by employing the gyrokinetic <span class="hlt">electron</span> and fully kinetic ion (GeFi) particle-in-cell (PIC) simulation model with a realistic ion-to-<span class="hlt">electron</span> mass ratio mi/me. In contrast to the fully kinetic PIC simulation scheme, the fast <span class="hlt">electron</span> cyclotron motion and <span class="hlt">plasma</span> oscillations are systematically removed in the GeFi model, and hence one can employ the realistic mi/me. The GeFi simulations are benchmarked against and show excellent agreement with both the fully kinetic PIC simulation and the analytical eigenmode theory. Our studies indicate that, for small wavenumbers, ky, along the current direction, the most unstable eigenmodes are peaked at the location wheremore » $$\\vec{k}$$• $$\\vec{B}$$ =0, consistent with previous analytical and simulation studies. Here, $$\\vec{B}$$ is the equilibrium magnetic field and $$\\vec{k}$$ is the wavevector perpendicular to the nonuniformity direction. As ky increases, however, the most unstable eigenmodes are found to be peaked at $$\\vec{k}$$ •$$\\vec{B}$$ ≠0. Additionally, the simulation results indicate that varying mi/me, the current <span class="hlt">sheet</span> width, and the guide magnetic field can affect the stability of LHDI. Simulations with the varying mass ratio confirm the lower hybrid frequency and wave number scalings.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016PhPl...23g2104W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016PhPl...23g2104W"><span>3D electrostatic gyrokinetic <span class="hlt">electron</span> and fully kinetic ion simulation of lower-hybrid drift instability of Harris current <span class="hlt">sheet</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Wang, Zhenyu; Lin, Yu; Wang, Xueyi; Tummel, Kurt; Chen, Liu</p> <p>2016-07-01</p> <p>The eigenmode stability properties of three-dimensional lower-hybrid-drift-instabilities (LHDI) in a Harris current <span class="hlt">sheet</span> with a small but finite guide magnetic field have been systematically studied by employing the gyrokinetic <span class="hlt">electron</span> and fully kinetic ion (GeFi) particle-in-cell (PIC) simulation model with a realistic ion-to-<span class="hlt">electron</span> mass ratio mi/me . In contrast to the fully kinetic PIC simulation scheme, the fast <span class="hlt">electron</span> cyclotron motion and <span class="hlt">plasma</span> oscillations are systematically removed in the GeFi model, and hence one can employ the realistic mi/me . The GeFi simulations are benchmarked against and show excellent agreement with both the fully kinetic PIC simulation and the analytical eigenmode theory. Our studies indicate that, for small wavenumbers, ky, along the current direction, the most unstable eigenmodes are peaked at the location where k →.B → =0 , consistent with previous analytical and simulation studies. Here, B → is the equilibrium magnetic field and k → is the wavevector perpendicular to the nonuniformity direction. As ky increases, however, the most unstable eigenmodes are found to be peaked at k →.B → ≠0 . In addition, the simulation results indicate that varying mi/me , the current <span class="hlt">sheet</span> width, and the guide magnetic field can affect the stability of LHDI. Simulations with the varying mass ratio confirm the lower hybrid frequency and wave number scalings.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/20898721','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/20898721"><span>Energy Measurements of Trapped <span class="hlt">Electrons</span> from a <span class="hlt">Plasma</span> Wakefield Accelerator</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Kirby, Neil; Berry, Melissa; Blumenfeld, Ian; Decker, Franz-Josef; Hogan, Mark J.; Ischebeck, Rasmus; Iverson, Richard; Siemann, Robert H.; Walz, Dieter; Auerbach, David; Clayton, Christopher E.; Huang, Chengkun; Johnson, Devon; Joshi, Chandrashekhar; Lu, Wei; Marsh, Kenneth A.; Mori, Warren B.; Zhou, Miaomiao; Katsouleas, Thomas; Muggli, Patric</p> <p>2006-11-27</p> <p>Recent <span class="hlt">electron</span> beam driven <span class="hlt">plasma</span> wakefield accelerator experiments carried out at SLAC indicate trapping of <span class="hlt">plasma</span> <span class="hlt">electrons</span>. More charge came out of than went into the <span class="hlt">plasma</span>. Most of this extra charge had energies at or below the 10 MeV level. In addition, there were trapped <span class="hlt">electron</span> streaks that extended from a few GeV to tens of GeV, and there were mono-energetic trapped <span class="hlt">electron</span> bunches with tens of GeV in energy.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/896940','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/896940"><span>Energy Measurements of Trapped <span class="hlt">Electrons</span> from a <span class="hlt">Plasma</span> Wakefield Accelerator</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Kirby, Neal; Auerbach, David; Berry, Melissa; Blumenfeld, Ian; Clayton, Christopher E.; Decer, Franz-Josef; Hogan, Mark J.; Huang, Chengkun; Ischebeck, Rasmus; Iverson, Richard; Johnson, Devon; Joshi, Chadrashekhar; Katsouleas, Thomas; Lu, Wei; Marsh, Kenneth A.; Mori, Warren B.; Muggli, Patric; Oz, Erdem; Siemann, Robert H.; Walz, Dieter; Zhou, Miaomiao; /SLAC /UCLA /Southern California U.</p> <p>2007-01-03</p> <p>Recent <span class="hlt">electron</span> beam driven <span class="hlt">plasma</span> wakefield accelerator experiments carried out at SLAC indicate trapping of <span class="hlt">plasma</span> <span class="hlt">electrons</span>. More charge came out of than went into the <span class="hlt">plasma</span>. Most of this extra charge had energies at or below the 10 MeV level. In addition, there were trapped <span class="hlt">electron</span> streaks that extended from a few GeV to tens of GeV, and there were mono-energetic trapped <span class="hlt">electron</span> bunches with tens of GeV in energy.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2003JGRA..108.1074W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2003JGRA..108.1074W"><span>Modeling the inner <span class="hlt">plasma</span> <span class="hlt">sheet</span> protons and magnetic field under enhanced convection</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Wang, Chih-Ping; Lyons, Larry R.; Chen, Margaret W.; Wolf, Richard A.; Toffoletto, Frank R.</p> <p>2003-02-01</p> <p>In order to understand the evolution of the protons and magnetic field in the inner <span class="hlt">plasma</span> <span class="hlt">sheet</span> from quiet to disturbed conditions, we incorporate a modified version of the Magnetospheric Specification Model (MSM) with a modified version of the Tsyganenko 96 (T96) magnetic field model to simulate the protons and magnetic field under an increasing convection electric field with two-dimensional (2-D) force balance maintained along the midnight meridian. The local time dependent proton differential fluxes assigned to the model boundary are a mixture of hot <span class="hlt">plasma</span> from the mantle and cooler <span class="hlt">plasma</span> from the low latitude boundary layer (LLBL). We previously used this model to simulate the inner <span class="hlt">plasma</span> <span class="hlt">sheet</span> under weak convection corresponding to a cross polar cap potential drop (ΔΦPC) equal to 26 kV and obtained 2-D quiet time equilibrium for proton and magnetic field that agrees well with observations. We start our simulation for enhanced convection with this quiet time equilibrium and time-independent boundary particle sources and increase ΔΦPC steadily from 26 to 146 kV in 5 hours. Simulations are also run separately to steady states by keeping ΔΦPC constant after it is increased to 98 and 146 kV. The magnitudes of proton pressure, number density, and temperature and their increase from quiet to moderate activity (ΔΦPC = 98 kV) are consistent with most observations. Our simulation at high activity (ΔΦPC = 146 kV) underestimates the observed pressure and temperature. This disagreement indicates possible dependence of the boundary particle sources on activity and possible effects of solar wind dynamic pressure enhancements that have not yet been included in our simulation. The simulated equatorial pressures and temperatures show stronger enhancement on the dusk side than on the dawn side as convection is increased, while density profiles show an increase on the dawn side and a decrease on the dusk side. The simulated proton flow speed at the equatorial plane</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/22086170','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/22086170"><span>A research of W-band folded waveguide traveling wave tube with elliptical <span class="hlt">sheet</span> <span class="hlt">electron</span> beam</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Guo Guo; Wei Yanyu; Yue Lingna; Gong Yubin; Zhao Guoqing; Huang Minzhi; Tang Tao; Wang Wenxiang</p> <p>2012-09-15</p> <p>Folded waveguide (FWG) traveling wave tube (TWT), which shows advantages in high power capacity, moderate bandwidth, and low-cost fabrication, has become the focus of vacuum <span class="hlt">electronics</span> recently. <span class="hlt">Sheet</span> <span class="hlt">electron</span> beam devices are better suited for producing radiation sources with large power in millimeter wave spectrum due to their characteristics of relatively low space charge fields and large transport current. A FWG TWT with elliptical <span class="hlt">sheet</span> beam working in W-band is presented in this paper, with the analysis of its dispersion characteristics, coupling impedance, transmission properties, and interaction characteristics. A comparison is also made with the traditional FWG TWT. Simulation results lead to the conclusion that the FWG TWT with elliptical <span class="hlt">sheet</span> beam investigated in this paper can make full use of relatively large electric fields and thus generate large output power with the same electric current density.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/1193626','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/1193626"><span>Fact <span class="hlt">Sheet</span> for KM200 Front-end <span class="hlt">Electronics</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Ianakiev, Kiril Dimitrov; Iliev, Metodi; Swinhoe, Martyn Thomas</p> <p>2015-07-08</p> <p>The KM200 device is a versatile, configurable front-end <span class="hlt">electronics</span> boards that can be used as a functional replacement for Canberra’s JAB-01 boards based on the Amptek A-111 hybrid chip, which continues to be the preferred choice of <span class="hlt">electronics</span> for large number of the boards in junction boxes of multiplicity counters that process the signal from an array of 3He detectors. Unlike the A-111 chip’s fixed time constants and sensitivity range, the shaping time and sensitivity of the new KM200 can be optimized for demanding applications such as spent fuel, and thus could improve the safeguards measurements of existing systems where the A-111 or PDT <span class="hlt">electronics</span> does not perform well.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2006IAUJD...3E..36D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2006IAUJD...3E..36D"><span>New Class of Self-Consistent Current <span class="hlt">Sheets</span> and Filaments in Collisionless <span class="hlt">Plasma</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Derishev, E. V.; Kocharovsky, V. V.; Kocharovsky, Vl. V.; Martyanov, V. Yu.</p> <p>2006-08-01</p> <p>A continuous set of stationary current <span class="hlt">sheets</span> and filaments in collisionless multi-component <span class="hlt">plasma</span> is found analytically using integrals of two-dimensional motion of particles in the self-consistent magnetic field. In our solutions, which are relativistic in general, the magnetic energy density can be comparable to that of particles, and the spatial scale can be arbitrary compared to typical gyroradius of the particles. We consider the properties of newly found stationary solutions and their possible applications to analysis of magnetic field configurations emerging in various astrophysical <span class="hlt">plasmas</span>, including coronal structures, shocks and jets. The results are used for interpretation of recent observations and numerical simulations. By choosing particular dependence of particle distribution function on the integrals of motion we are able to obtain various profiles of magnetic field and self-consistent current, including non-monotone. The obtained solutions describe much more general class of equilibrium configurations as compared to known generalizations of Harris current <span class="hlt">sheets</span>. On this basis, we suggest a way to describe slow dynamics and filamentation of collisionless current configurations in coronal <span class="hlt">plasma</span> and in Active Galactic Nuclei, Gamma-Ray Bursts, and microquasars.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19860048610&hterms=plasma+Composition+Experiment&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3Dplasma%2BComposition%2BExperiment','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19860048610&hterms=plasma+Composition+Experiment&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3Dplasma%2BComposition%2BExperiment"><span>Survey of 0.1- to 16-keV/e <span class="hlt">plasma</span> <span class="hlt">sheet</span> ion composition</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Lennartsson, W.; Shelley, E. G.</p> <p>1986-01-01</p> <p>An analysis is performed of all <span class="hlt">plasma</span> <span class="hlt">sheet</span> data collected in 1978-79 in order to discern statistical trends in the data. Attention is focused on the bulk parameters of 0.1-16 keV/e <span class="hlt">plasma</span> <span class="hlt">sheet</span> ions detected by the <span class="hlt">Plasma</span> Composition Experiment on the ISEE 1 satellite. The data were collected at 10-23 earth radii, and are averaged for various levels of activity in the AE index. Solar H(+) and He(2+) ions dominate during quiet periods and possess energies similar to those of the solar wind when the quiet period lasts several hours. Increasing AE index values eventually lead to a replacement of the solar ions with terrestrial ions, particularly O(+), which can have an average energy density of 3-4 keV/e at every activity level. The solar ions, however, increase in energy as their density decreases. The O(+) density is highest near the local midnight and becomes the most numerous during highly disturbed conditions. Finally, the O(+) density was observed to increase by a factor of three over the monitoring period, possibly due to enhanced solar EUV radiation.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li class="active"><span>13</span></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_13 --> <div id="page_14" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li class="active"><span>14</span></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="261"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1985AdSpR...5..411L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1985AdSpR...5..411L"><span>Relative contributions of terrestrial and solar wind ions in the <span class="hlt">plasma</span> <span class="hlt">sheet</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Lennartsson, W.; Sharp, R. D.</p> <p></p> <p>A major uncertainty concerning the origins of <span class="hlt">plasma</span> <span class="hlt">sheet</span> ions is due to the fact that terrestrial H(+) can have similar fluxes and energies as H(+) from the solar wind. The situation is especially ambiguous during magnetically quiet conditions (AE less than 60 gamma) when H(+) typically contributes more than 90 percent of the <span class="hlt">plasma</span> <span class="hlt">sheet</span> ion population. In this study that problem is examined using a large data set obtained by the ISEE-1 <span class="hlt">Plasma</span> Composition Experiment. The data suggest that one component of the H(+) increases in energy with increasing activity, roughly in proportion to 1/4 the energy of the He(++), whereas the other H(+) component has about the same energy at all activity levels, as do the O(+) and the He(+). If it is assumed that the H(+) of solar wind origin on the average has about the same energy-per-nucleon as the He(++), which is presumably almost entirely from the solar wind, then the data imply that as much as 20-30 percent of the H(+) can be of terrestrial origin even during quiet conditions.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1986JGR....91.3061L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1986JGR....91.3061L"><span>Survey of 0.1- to 16-keV/e <span class="hlt">plasma</span> <span class="hlt">sheet</span> ion composition</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Lennartsson, W.; Shelley, E. G.</p> <p>1986-03-01</p> <p>An analysis is performed of all <span class="hlt">plasma</span> <span class="hlt">sheet</span> data collected in 1978-79 in order to discern statistical trends in the data. Attention is focused on the bulk parameters of 0.1-16 keV/e <span class="hlt">plasma</span> <span class="hlt">sheet</span> ions detected by the <span class="hlt">Plasma</span> Composition Experiment on the ISEE 1 satellite. The data were collected at 10-23 earth radii, and are averaged for various levels of activity in the AE index. Solar H(+) and He(2+) ions dominate during quiet periods and possess energies similar to those of the solar wind when the quiet period lasts several hours. Increasing AE index values eventually lead to a replacement of the solar ions with terrestrial ions, particularly O(+), which can have an average energy density of 3-4 keV/e at every activity level. The solar ions, however, increase in energy as their density decreases. The O(+) density is highest near the local midnight and becomes the most numerous during highly disturbed conditions. Finally, the O(+) density was observed to increase by a factor of three over the monitoring period, possibly due to enhanced solar EUV radiation.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/1032746','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/1032746"><span>Status of <span class="hlt">Plasma</span> <span class="hlt">Electron</span> Hose Instability Studies in FACET</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Adli, Erik; England, Robert Joel; Frederico, Joel; Hogan, Mark; Li, Selina Zhao; Litos, Michael Dennis; Nosochkov, Yuri; An, Weiming; Mori, Warren; /UCLA</p> <p>2011-12-13</p> <p>In the FACET <span class="hlt">plasma</span>-wakefield acceleration experiment a dense 23 GeV <span class="hlt">electron</span> beam will interact with lithium and cesium <span class="hlt">plasmas</span>, leading to <span class="hlt">plasma</span> ion-channel formation. The interaction between the <span class="hlt">electron</span> beam and the <span class="hlt">plasma</span> sheath-<span class="hlt">electrons</span> may lead to a fast growing <span class="hlt">electron</span> hose instability. By using optics dispersion knobs to induce a controlled z-x tilt along the beam entering the <span class="hlt">plasma</span>, we investigate the transverse behavior of the beam in the <span class="hlt">plasma</span> as function of the tilt. We seek to quantify limits on the instability in order to further explore potential limitations on future <span class="hlt">plasma</span> wakefield accelerators due to the <span class="hlt">electron</span> hose instability. The FACET <span class="hlt">plasma</span>-wakefield experiment at SLAC will study beam driven <span class="hlt">plasma</span> wakefield acceleration. A dense 23 GeV <span class="hlt">electron</span> beam will interact with lithium or cesium <span class="hlt">plasma</span>, leading to <span class="hlt">plasma</span> ion-channel formation. The interaction between the <span class="hlt">electron</span> beam and the <span class="hlt">plasma</span> sheath-<span class="hlt">electrons</span> drives the <span class="hlt">electron</span> hose instability, as first studied by Whittum. While Ref. [2] indicates the possibility of a large instability growth rate for typical beam and <span class="hlt">plasma</span> parameters, other studies including have shown that several physical effects may mitigate the hosing growth rate substantially. So far there has been no quantitative benchmarking of experimentally observed hosing in previous experiments. At FACET we aim to perform such benchmarking by for example inducing a controlled z-x tilt along the beamentering the <span class="hlt">plasma</span>, and observing the transverse behavior of the beam in the <span class="hlt">plasma</span> as function. The long-term objective of these studies is to quantify potential limitations on future <span class="hlt">plasma</span> wakefield accelerators due to the <span class="hlt">electron</span> hose instability.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014JGRA..119.2836M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014JGRA..119.2836M"><span>Spatial variation in the <span class="hlt">plasma</span> <span class="hlt">sheet</span> composition: Dependence on geomagnetic and solar activity</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Maggiolo, R.; Kistler, L. M.</p> <p>2014-04-01</p> <p>We study the spatial distribution of <span class="hlt">plasma</span> <span class="hlt">sheet</span> O+ and H+ ions using data from the COmposition and DIstribution Function (CODIF) instrument on board the Cluster spacecraft from 2001 to 2005. The densities are mapped along magnetic field lines to produce bidimensional density maps at the magnetospheric equatorial plane for various geomagnetic and solar activity levels (represented by the Kp and F10.7 indexes). We analyze the correlation of the O+ and H+ density with Kp and F10.7 in the midtail region at geocentric distances between 15 and 20 RE and in the near-Earth regions at radial distances between 7 and 8 RE. Near Earth the H+ density slightly increases with Kp and F10.7 while in the midtail region it is not correlated with Kp and F10.7. On the contrary, the amount of O+ ions significantly increases with Kp and F10.7 independently of the region. In the near-Earth region, the effects of solar EUV and geomagnetic activity on the O+ density are comparable. In the midtail region, the O+ density increases at a lower rate with solar EUV flux but strongly increases with geomagnetic activity although the effect is modulated by the solar EUV flux level. We also evidence a strong increase of the proportion of O+ ions with decreasing geocentric distance below ~10 RE. These results confirm the direct entry of O+ ions into the near-Earth <span class="hlt">plasma</span> <span class="hlt">sheet</span> and suggest that both energetic outflows from the auroral zone and cold outflow from the high-latitude ionosphere may contribute to feed the near-Earth <span class="hlt">plasma</span> <span class="hlt">sheet</span> with ionospheric ions.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2003PhDT........12U','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2003PhDT........12U"><span><span class="hlt">Electron</span> temperature dynamics of TEXTOR <span class="hlt">plasmas</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Udintsev, Victor Sergeevich</p> <p>2003-11-01</p> <p>To study <span class="hlt">plasma</span> properties in the presence of large and small MHD modes, new high-resolution ECE diagnostics have been installed at TEXTOR tokamak, and some of the already existing systems have been upgraded. Two models for the <span class="hlt">plasma</span> transport properties inside large m/n = 2/1 MHD islands have been found to give estimations for the heat diffusivities, which are much lower than the global <span class="hlt">plasma</span> heat diffusivity, which is in agreement with previous measurements in different tokamaks. The 3D-reconstruction of large m/n = 2/1 modes in TEXTOR with the help of all available ECE diagnostics allows modelling the island as a structure with closed flux surfaces. The main <span class="hlt">plasma</span> heat flux flows through the X-point area probably along stochastic magnetic field lines. The confinement is improved within the magnetic island, compared to the background <span class="hlt">plasma</span>. This is confirmed by a temperature profile flattening and sometimes even a secondary peaking inside the island, compared to the X-point. Making use of the mode rotation, assumed to be a rigid rotor, it has been possible to obtain information on the topology of the m = 1 precursor mode leading to sawtooth collapses. It becomes clear that this precursor cannot be described by an m = 1 cold tearing mode island but by a hot crescent wrapped around a cold high-density bubble. In the future multi-chord ECE-imaging will allow this mode reconstruction without the assumption of the rotation to be rigid. From the measurements of the broadband temperature and density fluctuations one can conclude that the turbulent structures inside the q = 1 surface are separated from the turbulence outside the q = 1 surface. This fits nicely with the observation that q = 1 surface acts as a barrier for the thermal transport. Correlation length and time measured inside q = 1 are in agreement with the observed turbulent heat diffusivity. Qualitative studies of non-thermal <span class="hlt">electrons</span> at different heating regimes (ECRH and Ohmic) at TEXTOR were done</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19910030164&hterms=IRM&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3DIRM','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19910030164&hterms=IRM&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3DIRM"><span>Spatial variations in the suprathermal ion distributions during substorms in the <span class="hlt">plasma</span> <span class="hlt">sheet</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Kistler, L. M.; Moebius, E.; Klecker, B.; Gloeckler, G.; Ipavich, F. M.</p> <p>1990-01-01</p> <p>The preinjection and postinjection suprathermal energy spectra of the ion species H(+), O(+), He(+), and He(++) in two events in which substorm-associated particle injections were observed in both the near-earth <span class="hlt">plasma</span> <span class="hlt">sheet</span> and farther down the tail were determined using data obtained by the Suprathermal Energetic Ion Charge Analyzer on AMPTE IRM and the Charge Energy Mass Spectrometer on AMPTE CCE. Similar spectral changes were observed in both locations. In both cases, the spectra became harder with injection. Postinjection, the flux decreased exponentially with radial distance. The gradients observed for all ion species were very similar.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2003PhPl...10.1526G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2003PhPl...10.1526G"><span>Nonlinear effects at the boundary of an <span class="hlt">electron</span> <span class="hlt">plasma</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Gradov, O. M.; Stenflo, L.; Shukla, P. K.</p> <p>2003-05-01</p> <p>Two solutions for nonlinear <span class="hlt">electron</span> <span class="hlt">plasma</span> waves propagating along a cold <span class="hlt">plasma</span> boundary are reported. Thus, the nonlinear frequency shift caused by the harmonic generation as well as new localized nonlinear perturbations are found.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/22489971','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/22489971"><span>Generation of anomalously energetic suprathermal <span class="hlt">electrons</span> by an <span class="hlt">electron</span> beam interacting with a nonuniform <span class="hlt">plasma</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Sydorenko, D.; Kaganovich, I. D.; Chen, L.; Ventzek, P. L. G.</p> <p>2015-12-15</p> <p>Generation of anomalously energetic suprathermal <span class="hlt">electrons</span> was observed in simulation of a high-voltage dc discharge with <span class="hlt">electron</span> emission from the cathode. An <span class="hlt">electron</span> beam produced by the emission interacts with the nonuniform <span class="hlt">plasma</span> in the discharge via a two-stream instability. The energy transfer from the beam to the <span class="hlt">plasma</span> <span class="hlt">electrons</span> is ensured by the <span class="hlt">plasma</span> nonuniformity. The <span class="hlt">electron</span> beam excites <span class="hlt">plasma</span> waves whose wavelength and phase speed gradually decrease towards anode. The waves with short wavelength near the anode accelerate <span class="hlt">plasma</span> bulk <span class="hlt">electrons</span> to suprathermal energies. The sheath near the anode reflects some of the accelerated <span class="hlt">electrons</span> back into the <span class="hlt">plasma</span>. These <span class="hlt">electrons</span> travel through the <span class="hlt">plasma</span>, reflect near the cathode, and enter the accelerating area again but with a higher energy than before. Such particles are accelerated to energies much higher than after the first acceleration. This mechanism plays a role in explaining earlier experimental observations of energetic suprathermal <span class="hlt">electrons</span> in similar discharges.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19810025909&hterms=moebius&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3Dmoebius','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19810025909&hterms=moebius&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3Dmoebius"><span>Observations of a nonthermal ion layer at the <span class="hlt">plasma</span> <span class="hlt">sheet</span> boundary during substorm recovery</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Moebius, E.; Scholer, M.; Hovestadt, D.; Klecker, B.; Ipavich, F. M.; Gloeckler, G.</p> <p>1980-01-01</p> <p>Measurements of the energy and angular distributions of energetic protons and alpha particles (not less than 30 keV/charge) in the geomagnetic tail are presented. The measurements were made during the recovery phase of a geomagnetic substorm on Apr. 19, 1978, with the Max-Planck-Institut/University of Maryland sensor system on the Isee 1 satellite. The measurements were also correlated with <span class="hlt">plasma</span> observations made by the LASL/MPE instrument on Isee 1. The data reveal the presence of a thin nonthermal layer of protons and alpha particles at the <span class="hlt">plasma</span> <span class="hlt">sheet</span> boundary. The particles have their maximum flux at 60 keV/charge and are streaming highly collimated in the earthward direction. The alpha particle layer is confined within the proton layer. Many aspects of the observations are in agreement with an acceleration model near the neutral line proposed by Jaeger and Speiser (1974)</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/22486421','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/22486421"><span>An exact collisionless equilibrium for the Force-Free Harris <span class="hlt">Sheet</span> with low <span class="hlt">plasma</span> beta</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Allanson, O. Neukirch, T. Wilson, F. Troscheit, S.</p> <p>2015-10-15</p> <p>We present a first discussion and analysis of the physical properties of a new exact collisionless equilibrium for a one-dimensional nonlinear force-free magnetic field, namely, the force-free Harris <span class="hlt">sheet</span>. The solution allows any value of the <span class="hlt">plasma</span> beta, and crucially below unity, which previous nonlinear force-free collisionless equilibria could not. The distribution function involves infinite series of Hermite polynomials in the canonical momenta, of which the important mathematical properties of convergence and non-negativity have recently been proven. Plots of the distribution function are presented for the <span class="hlt">plasma</span> beta modestly below unity, and we compare the shape of the distribution function in two of the velocity directions to a Maxwellian distribution.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2009AnGeo..27.1729L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009AnGeo..27.1729L"><span>Cluster view of the <span class="hlt">plasma</span> <span class="hlt">sheet</span> boundary layer and bursty bulk flow connection</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Lennartsson, O. W.; Kistler, L. M.; Rème, H.</p> <p>2009-04-01</p> <p>The high-latitude boundaries of the <span class="hlt">plasma</span> <span class="hlt">sheet</span> (PSBL) are dynamic latitude zones of recurring and transient (minutes to tens of minutes) earthward and magnetic field-aligned bursts of <span class="hlt">plasma</span>, each being more or less confined in longitude as well, whose ionic component is dominated by protons with flux, energies and density that are consistent with a central <span class="hlt">plasma</span> <span class="hlt">sheet</span> (CPS) source at varying distance (varying rates of energy time dispersion), sometimes as close as the ~19 RE Cluster apogees, or closer still. The arguably most plausible source consists of so called "bursty bulk flows" (BBFs), i.e. proton bulk flow events with large, positive and bursty GSE vx. Known mainly from CPS observations made at GSE x>-30 RE, the BBF type events probably take place much further downtail as well. What makes the BBFs an especially plausible source are (1) their earthward bulk flow, which helps explain the lack of distinctive latitudinal PSBL energy dispersion, and (2) their association with a transient strong increase of the local tail Bz component ("local dipolarization"). The enhanced Bz provides intermittent access to higher latitudes for the CPS <span class="hlt">plasma</span>, resulting in local density reductions in the tail midplane, as illustrated here by proton data from the Cluster CIS CODIF instruments. Another sign of kinship between the PSBL bursts and the BBFs is their similar spatial fine structure. The PSBL bursts have prominent filaments aligned along the magnetic field with transverse flux gradients that are often characterized by local ~10 keV proton gyroradii scale size (or even smaller), as evidenced by Cluster measurements. The same kind of fine structure is also found during Cluster near-apogee traversals of the tail midplane, as illustrated here and implied by recently published statistics on BBFs obtained with Cluster multipoint observations at varying satellite separations. Altogether, the Cluster observations described here mesh rather well with theories about so called</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016PhRvL.117i5001J','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016PhRvL.117i5001J"><span>Laboratory Observation of Resistive <span class="hlt">Electron</span> Tearing in a Two-Fluid Reconnecting Current <span class="hlt">Sheet</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Jara-Almonte, Jonathan; Ji, Hantao; Yamada, Masaaki; Yoo, Jongsoo; Fox, William</p> <p>2016-08-01</p> <p>The spontaneous formation of plasmoids via the resistive <span class="hlt">electron</span> tearing of a reconnecting current <span class="hlt">sheet</span> is observed in the laboratory. These experiments are performed during driven, antiparallel reconnection in the two-fluid regime within the Magnetic Reconnection Experiment. It is found that plasmoids are present even at a very low Lundquist number, and the number of plasmoids scales with both the current <span class="hlt">sheet</span> aspect ratio and the Lundquist number. The reconnection electric field increases when plasmoids are formed, leading to an enhanced reconnection rate.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/1334747','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/1334747"><span>Laboratory observation of resistive <span class="hlt">electron</span> tearing in a two-fluid reconnecting current <span class="hlt">sheet</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Jara-Almonte, Jonathan; Ji, Hantao; Yamada, Masaaki; Yoo, Jongsoo; Fox, William</p> <p>2016-08-25</p> <p>The spontaneous formation of plasmoids via the resistive <span class="hlt">electron</span> tearing of a reconnecting current <span class="hlt">sheet</span> is observed in the laboratory. These experiments are performed during driven, antiparallel reconnection in the two-fluid regime within the Magnetic Reconnection Experiment. It is found that plasmoids are present even at a very low Lundquist number, and the number of plasmoids scales with both the current <span class="hlt">sheet</span> aspect ratio and the Lundquist number. Furthermore, the reconnection electric field increases when plasmoids are formed, leading to an enhanced reconnection rate.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/27610861','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/27610861"><span>Laboratory Observation of Resistive <span class="hlt">Electron</span> Tearing in a Two-Fluid Reconnecting Current <span class="hlt">Sheet</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Jara-Almonte, Jonathan; Ji, Hantao; Yamada, Masaaki; Yoo, Jongsoo; Fox, William</p> <p>2016-08-26</p> <p>The spontaneous formation of plasmoids via the resistive <span class="hlt">electron</span> tearing of a reconnecting current <span class="hlt">sheet</span> is observed in the laboratory. These experiments are performed during driven, antiparallel reconnection in the two-fluid regime within the Magnetic Reconnection Experiment. It is found that plasmoids are present even at a very low Lundquist number, and the number of plasmoids scales with both the current <span class="hlt">sheet</span> aspect ratio and the Lundquist number. The reconnection electric field increases when plasmoids are formed, leading to an enhanced reconnection rate.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015AGUFMSM43A..02N','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015AGUFMSM43A..02N"><span>Effect of <span class="hlt">electron</span> ambient <span class="hlt">plasmas</span> in reconnection jets and dipolarization fronts : MMS initial results</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Nakamura, R.; Torkar, K.; Andriopoulou, M.; Jeszenszky, H.; Plaschke, F.; Baumjohann, W.; Magnes, W.; Fischer, D.; Schmid, D.; Steller, M.; Nakamura, T.; Scharlemann, C.; Torbert, R. B.; Burch, J. L.; Ergun, R. E.; Lindqvist, P. A.; Marklund, G. T.; Khotyaintsev, Y. V.; Russell, C. T.; Strangeway, R. J.; Leinweber, H. K.; Anderson, B. J.; Le, G.; Bromund, K. R.; Fuselier, S. A.; Chutter, M.; Slavin, J. A.; Kepko, L.; Le Contel, O.; Pollock, C. J.; Dorelli, J.; Gershman, D. J.; Mauk, B.; Vaith, H.; Kletzing, C.; Bounds, S. R.; Sigsbee, K. M.</p> <p>2015-12-01</p> <p>With the successful launch of Magnetospheric Multiscale Misssion (MMS), it becomes possible to observe the dynamic signatures of magnetospheric transients with high-time resolution measurements of electromagnetic fields and <span class="hlt">plasma</span>. The Active Spacecraft Potential Control (ASPOC) neutralizes the spacecraft potential by releasing positive charge produced by indium and thereby controlling the spacecraft potential in order to enable accurate measurements also in sparse <span class="hlt">plasma</span> environments essential to study properties of reconnection. Since the current balance around the spacecraft is maintained by contribution also from the ambient <span class="hlt">plasma</span>, predominantly <span class="hlt">electrons</span>, ASPOC beam current values combined with spacecraft potential data from FIELDS instruments enable to deduce the ambient <span class="hlt">electron</span> <span class="hlt">plasma</span> parameters . Particularly, using data from multi-spacecraft measurements with different ASPOC current levels and FIELDS data, parameters on ambient <span class="hlt">electron</span> temperature and density can be deduced. Monitoring the environmental <span class="hlt">plasma</span> parameters are essential to determine the accurate scales of the structure or wave length relative to <span class="hlt">plasma</span> scales and hence to understand the physical processes. In this study we investigate the changes of the <span class="hlt">electron</span> parameters in the transient structures such as the magnetic field disturbance forming at the front of BBF/flow bursts, called dipolarization front (DF), and reconnection jets in thin current <span class="hlt">sheets</span> obtained by MMS mainly during the commissioning phase when the spacecraft traversed the near-Earth tail.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/22300126','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/22300126"><span>High and low frequency instabilities driven by counter-streaming <span class="hlt">electron</span> beams in space <span class="hlt">plasmas</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Mbuli, L. N.; Maharaj, S. K.; Bharuthram, R.</p> <p>2014-05-15</p> <p>A four-component <span class="hlt">plasma</span> composed of a drifting (parallel to ambient magnetic field) population of warm <span class="hlt">electrons</span>, drifting (anti-parallel to ambient magnetic field) cool <span class="hlt">electrons</span>, stationary hot <span class="hlt">electrons</span>, and thermal ions is studied in an attempt to further our understanding of the excitation mechanisms of broadband electrostatic noise (BEN) in the Earth's magnetospheric regions such as the magnetosheath, plasmasphere, and <span class="hlt">plasma</span> <span class="hlt">sheet</span> boundary layer (PSBL). Using kinetic theory, beam-driven electrostatic instabilities such as the ion-acoustic, <span class="hlt">electron</span>-acoustic instabilities are found to be supported in our multi-component model. The dependence of the instability growth rates and real frequencies on various <span class="hlt">plasma</span> parameters such as beam speed, number density, temperature, and temperature anisotropy of the counter-streaming (relative to ambient magnetic field) cool <span class="hlt">electron</span> beam are investigated. It is found that the number density of the anti-field aligned cool <span class="hlt">electron</span> beam and drift speed play a central role in determining which instability is excited. Using <span class="hlt">plasma</span> parameters which are closely correlated with the measurements made by the Cluster satellites in the PSBL region, we find that the <span class="hlt">electron</span>-acoustic and ion-acoustic instabilities could account for the generation of BEN in this region.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/19373367','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/19373367"><span>Picosecond imaging of low-density <span class="hlt">plasmas</span> by <span class="hlt">electron</span> deflectometry.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Centurion, M; Reckenthaeler, P; Krausz, F; Fill, E E</p> <p>2009-02-15</p> <p>We have imaged optical-field ionized <span class="hlt">plasmas</span> with <span class="hlt">electron</span> densities as low as 10(13) cm(-3) on a picosecond timescale using ultrashort <span class="hlt">electron</span> pulses. Electric fields generated by the separation of charges are imprinted on a 20 keV probe <span class="hlt">electron</span> pulse and reveal a cloud of <span class="hlt">electrons</span> expanding away from a positively charged <span class="hlt">plasma</span> core. Our method allows for a direct measurement of the <span class="hlt">electron</span> energy required to escape the <span class="hlt">plasma</span> and the total charge. Simulations reproduce the main features of the experiment and allow determination of the energy of the <span class="hlt">electrons</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/5132827','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/5132827"><span>Spatial variations in the suprathermal ion distributions during substorms in the <span class="hlt">plasma</span> <span class="hlt">sheet</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Kistler, L.M.; Moebius, E.; Klecker, B. ); Gloeckler, G.; Ipavich, F.M.; Hamilton, D.C. )</p> <p>1990-11-01</p> <p>Using data from AMPTE IRM and AMPTE CCE, the authors have determined the pre- and post-injection suprathermal energy spectra for the ion species H{sup +}, O{sup +}, He{sup +}, and He{sup ++} for six events in which substorm-associated particle injections are observed in both the near-Earth <span class="hlt">plasma</span> <span class="hlt">sheet</span> and farther down the tail. They find similar spectral changes in both locations, with the spectra becoming harder with the injection. Post-injection, the flux decreases exponentially with radial distance. Approximately the same gradient is observed in all species. In addition, they find that although the O{sup +}/H{sup +} and the He{sup ++}/H{sup +} ratios increase with energy per charge, the ratios are approximately the same at the same energy per charge at the two spacecraft. The observations are difficult to explain either with a model in which the ions are accelerated at a neutral line and transported toward Earth or with a model in which the ions are accelerated in the near-Earth region by current disruption/diversion and transported down the tail. In either case, the ions would have to be transported throughout the tail without much energization or deenergization in order to explain the energy per charge correlations. Further, earthward transport without energization would not lead to the observed radial gradient. A combination of these acceleration mechanisms, a disturbance that propagates throughout the <span class="hlt">plasma</span> <span class="hlt">sheet</span>, or a more global mechanism may explain the observations.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=20110011013&hterms=statistics&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3Dstatistics','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20110011013&hterms=statistics&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3Dstatistics"><span>Multiscale Auroral Emission Statistics as Evidence of Turbulent Reconnection in Earth's Midtail <span class="hlt">Plasma</span> <span class="hlt">Sheet</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Klimas, Alex; Uritsky, Vadim; Donovan, Eric</p> <p>2010-01-01</p> <p>We provide indirect evidence for turbulent reconnection in Earth's midtail <span class="hlt">plasma</span> <span class="hlt">sheet</span> by reexamining the statistical properties of bright, nightside auroral emission events as observed by the UVI experiment on the Polar spacecraft and discussed previously by Uritsky et al. The events are divided into two groups: (1) those that map to absolute value of (X(sub GSM)) < 12 R(sub E) in the magnetotail and do not show scale-free statistics and (2) those that map to absolute value of (X(sub GSM)) > 12 R(sub E) and do show scale-free statistics. The absolute value of (X(sub GSM)) dependence is shown to most effectively organize the events into these two groups. Power law exponents obtained for group 2 are shown to validate the conclusions of Uritsky et al. concerning the existence of critical dynamics in the auroral emissions. It is suggested that the auroral dynamics is a reflection of a critical state in the magnetotail that is based on the dynamics of turbulent reconnection in the midtail <span class="hlt">plasma</span> <span class="hlt">sheet</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/27722039','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/27722039"><span>THEMIS two-point measurements of the cross-tail current density: A thick bifurcated current <span class="hlt">sheet</span> in the near-Earth <span class="hlt">plasma</span> <span class="hlt">sheet</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Saito, Miho</p> <p>2015-08-01</p> <p>The basic properties of the near-Earth current <span class="hlt">sheet</span> from 8 RE to 12 RE were determined based on Time History of Events and Macroscale Interactions during Substorms (THEMIS) observations from 2007 to 2013. Ampere's law was used to estimate the current density when the locations of two spacecraft were suitable for the calculation. A total of 3838 current density observations were obtained to study the vertical profile. For typical solar wind conditions, the current density near (off) the central plane of the current <span class="hlt">sheet</span> ranged from 1 to 2 nA/m(2) (1 to 8 nA/m(2)). All the high current densities appeared off the central plane of the current <span class="hlt">sheet</span>, indicating the formation of a bifurcated current <span class="hlt">sheet</span> structure when the current density increased above 2 nA/m(2). The median profile also showed a bifurcated structure, in which the half thickness was about 3 RE . The distance between the peak of the current density and the central plane of the current <span class="hlt">sheet</span> was 0.5 to 1 RE . High current densities above 4 nA/m(2) were observed in some cases that occurred preferentially during substorms, but they also occurred in quiet times. In contrast to the commonly accepted picture, these high current densities can form without a high solar wind dynamic pressure. In addition, these high current densities can appear in two magnetic configurations: tail-like and dipolar structures. At least two mechanisms, magnetic flux depletion and new current system formation during the expansion phase, other than <span class="hlt">plasma</span> <span class="hlt">sheet</span> compression are responsible for the formation of the bifurcated current <span class="hlt">sheets</span>.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li class="active"><span>14</span></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_14 --> <div id="page_15" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li class="active"><span>15</span></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="281"> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5046188','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5046188"><span>THEMIS two‐point measurements of the cross‐tail current density: A thick bifurcated current <span class="hlt">sheet</span> in the near‐Earth <span class="hlt">plasma</span> <span class="hlt">sheet</span></span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p></p> <p>2015-01-01</p> <p>Abstract The basic properties of the near‐Earth current <span class="hlt">sheet</span> from 8 RE to 12 RE were determined based on Time History of Events and Macroscale Interactions during Substorms (THEMIS) observations from 2007 to 2013. Ampere's law was used to estimate the current density when the locations of two spacecraft were suitable for the calculation. A total of 3838 current density observations were obtained to study the vertical profile. For typical solar wind conditions, the current density near (off) the central plane of the current <span class="hlt">sheet</span> ranged from 1 to 2 nA/m2 (1 to 8 nA/m2). All the high current densities appeared off the central plane of the current <span class="hlt">sheet</span>, indicating the formation of a bifurcated current <span class="hlt">sheet</span> structure when the current density increased above 2 nA/m2. The median profile also showed a bifurcated structure, in which the half thickness was about 3 RE. The distance between the peak of the current density and the central plane of the current <span class="hlt">sheet</span> was 0.5 to 1 RE. High current densities above 4 nA/m2 were observed in some cases that occurred preferentially during substorms, but they also occurred in quiet times. In contrast to the commonly accepted picture, these high current densities can form without a high solar wind dynamic pressure. In addition, these high current densities can appear in two magnetic configurations: tail‐like and dipolar structures. At least two mechanisms, magnetic flux depletion and new current system formation during the expansion phase, other than <span class="hlt">plasma</span> <span class="hlt">sheet</span> compression are responsible for the formation of the bifurcated current <span class="hlt">sheets</span>. PMID:27722039</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19910060899&hterms=resistivity&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3Dresistivity','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19910060899&hterms=resistivity&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3Dresistivity"><span>Forced magnetic reconnection in a <span class="hlt">plasma</span> <span class="hlt">sheet</span> with localized resistivity profile excited by lower hybrid drift type instability</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Hoshino, M.</p> <p>1991-01-01</p> <p>A forced magnetic reconnection process with a temporal evolution of resistivity is studied for a <span class="hlt">plasma</span> <span class="hlt">sheet</span> with a nonuniform resistivity profile based on the nonlocal mode structure of the lower hybrid drift type instability. The growth rate of the mode found is almost independent of the resistivity at the neutral <span class="hlt">sheet</span>, but depends on the resistivity of the region of maximum density gradient away from the neutral <span class="hlt">sheet</span>. This is studied by using both a nonlinear numerical MHD simulation and a linear theory. The mode may be relevant to the prevalent theoretical concept of MHD reconnection and the localized anomalous resistivity profile based on the lower hybrid drift instability.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014SoPh..289.1607Z','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014SoPh..289.1607Z"><span><span class="hlt">Electron</span> Acceleration in a Dynamically Evolved Current <span class="hlt">Sheet</span> Under Solar Coronal Conditions</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Zhang, Shaohua; Du, A. M.; Feng, Xueshang; Cao, Xin; Lu, Quanming; Yang, Liping; Chen, Gengxiong; Zhang, Ying</p> <p>2014-05-01</p> <p><span class="hlt">Electron</span> acceleration in a drastically evolved current <span class="hlt">sheet</span> under solar coronal conditions is investigated via the combined 2.5-dimensional (2.5D) resistive magnetohydrodynamics (MHD) and test-particle approaches. Having a high magnetic Reynolds number (105), the long, thin current <span class="hlt">sheet</span> is torn into a chain of magnetic islands, which grow in size and coalesce with each other. The acceleration of <span class="hlt">electrons</span> is explored in three typical evolution phases: when several large magnetic islands are formed (phase 1), two of these islands are approaching each other (phase 2), and almost merging into a "monster" magnetic island (phase 3). The results show that for all three phases <span class="hlt">electrons</span> with an initial Maxwell distribution evolve into a heavy-tailed distribution and more than 20 % of the <span class="hlt">electrons</span> can be accelerated higher than 200 keV within 0.1 second and some of them can even be energized up to MeV ranges. The lower-energy <span class="hlt">electrons</span> are located away from the magnetic separatrices and the higher-energy <span class="hlt">electrons</span> are inside the magnetic islands. The most energetic <span class="hlt">electrons</span> have a tendency to be around the outer regions of the magnetic islands or to appear in the small secondary magnetic islands. It is the trapping effect of the magnetic islands and the distributions of E p that determine the acceleration and spatial distributions of the energetic <span class="hlt">electrons</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016PhPl...23j3513C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016PhPl...23j3513C"><span>A simple model for <span class="hlt">electron</span> temperature in dilute <span class="hlt">plasma</span> flows</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Cai, Chunpei; Cooke, David L.</p> <p>2016-10-01</p> <p>In this short note, we present some work on investigating <span class="hlt">electron</span> temperatures and potentials in steady dilute <span class="hlt">plasma</span> flows. The analysis is based on the detailed fluid model for <span class="hlt">electrons</span>. Ionizations, normalized <span class="hlt">electron</span> number density gradients, and magnetic fields are neglected. The transport properties are assumed as local constants. With these treatments, the partial differential equation for <span class="hlt">electron</span> temperature degenerates as an ordinary differential equation. Along an <span class="hlt">electron</span> streamline, two simple formulas for <span class="hlt">electron</span> temperature and <span class="hlt">plasma</span> potential are obtained. These formulas offer some insights, e.g., the <span class="hlt">electron</span> temperature and <span class="hlt">plasma</span> potential distributions along an <span class="hlt">electron</span> streamline include two exponential functions, and the one for <span class="hlt">plasma</span> potential includes an extra linear distribution function.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015AGUFMSM41I..06D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015AGUFMSM41I..06D"><span>The kinetic scale structure of the <span class="hlt">Plasma</span> <span class="hlt">Sheet</span> Boundary Layer: Implications of collisionless magnetic reconnection and first MMS observations</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Dorelli, J.; Gershman, D. J.; Avanov, L. A.; Pollock, C. J.; Giles, B. L.; Nakamura, R.; Chen, L. J.; Torbert, R. B.; Gliese, U.; Barrie, A. C.; Holland, M. P.; Chandler, M. O.; Coffey, V. N.; MacDonald, E.; Salo, C.; Dickson, C.; Saito, Y.; Russell, C. T.; Baumjohann, W.; Burch, J. L.</p> <p>2015-12-01</p> <p>The relationship between magnetic reconnection and the <span class="hlt">Plasma</span> <span class="hlt">Sheet</span> Boundary Layer (PSBL) is still an open problem in magnetospheric physics. While one can understand observed PSBL velocity distributions on the basis of a simple steady state drift-kinetic model with prescribed electric and magnetic fields (e.g., Onsager et al. [1990,1991]), such models do not incorporate the kinetic scale dynamics at the reconnection site. For example, Shay et al. [2011] have argued that the out-of-plane quadrupole magnetic field pattern at the reconnection site can be viewed as an obliquely propagating kinetic Alfvén wave with very large parallel group velocity, the implication being that the field-aligned current structure should quickly become global, though still confined to field lines connected to the ion diffusion region at the reconnection site. This raises the very interesting question: How would such a global wave structure appear in the PSBL on the kinetic scale? Here, we present some first observations of the PSBL by NASA's Magnetospheric Multiscale (MMS) mission where Fast <span class="hlt">Plasma</span> Investigation (FPI) Burst Data (30 ms and 150 ms resolution for 3D <span class="hlt">electron</span> and ion velocity distributions, respectively) is available during intervals where lower resolution (4.5 s) Fast Survey distributions showed evidence of connection to a remote reconnection site. This allows us to test for the first time whether the quadrupole magnetic field structure near the reconnection site -- a local structure already observed by previous spacecraft -- does indeed support a global field-aligned current pattern around the magnetic separatrix. We will also probe for the first time the <span class="hlt">electron</span> kinetic scale sub-structure of the PSBL and compare with <span class="hlt">electron</span>-scale features observed near the magnetic separatrix at the dayside magnetopause.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016SSCom.248..144A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016SSCom.248..144A"><span>Mechanical and <span class="hlt">electronic</span> properties of graphitic carbon nitride <span class="hlt">sheet</span>: First-principles calculations</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Abdullahi, Yusuf Zuntu; Yoon, Tiem Leong; Halim, Mohd Mahadi; Hashim, Md. Roslan; Lim, Thong Leng</p> <p>2016-12-01</p> <p>In this work, mechanical properties, elastic constants and the strain responses on the <span class="hlt">electronic</span> properties of graphitic heptazine are investigated using density functional theory. The computed lattice constant and bulk modulus are in good agreement with the available literatures. The in-plane stiffness compared well with a similar two-dimensional structure, whereas the Poisson's ratio value is close to that of graphene. The calculated critical points (elastic and yielding points) for both the uni- and bi-axial strains indicate that the heptazine material can withstand longer tensions in the plastic region. This shows that the heptazine <span class="hlt">sheet</span> is mechanically stable. Our calculations also predict enhanced band gap induced by small amount of bi-axial tensile strain within the elastic region. The increase in band gap is a result of symmetric deformations which predominantly affect the structural features of the <span class="hlt">sheet</span>, leading to the eventual reorientation in the atomic orbitals of the <span class="hlt">sheet</span>. We find no change in the <span class="hlt">electronic</span> properties of the <span class="hlt">sheet</span> under electric field up to a peak value of 10 V/nm. Such properties may serve as a guide for future nanodevice applications.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19770005001','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19770005001"><span>Observations at the planet Mercury by the <span class="hlt">plasma</span> <span class="hlt">electron</span> experiment, Mariner 10</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Ogilvie, K. W.; Scudder, J. D.; Vasyliunas, V. M.; Hartle, R. E.; Siscoe, G. L.</p> <p>1976-01-01</p> <p><span class="hlt">Plasma</span> <span class="hlt">electron</span> observations made onboard Mariner 10 are reported. Three encounters with the planet Mercury show that the planet interacts with the solar wind to form a bow shock and a permanent magnetosphere. The observations provide a determination of the dimensions and properties of the magnetosphere, independently of and in general agreement with magnetometer observations. The magnetosphere of Mercury appears to be similar in shape to that of the Earth but much smaller in relation to the size of the planet. <span class="hlt">Electron</span> populations similar to those found in the Earth's magnetotail, within the <span class="hlt">plasma</span> <span class="hlt">sheet</span> and adjacent regions, were observed at Mercury; both their spatial location and the <span class="hlt">electron</span> energy spectra within them bear qualitative and quantitative resemblance to corresponding observations at the Earth. The magnetosphere of Mercury resembles to a marked degree a reduced version of that of the Earth, with no significant differences of structure.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/829968','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/829968"><span>Vortices, Reconnection and Turbulence in High <span class="hlt">Electron</span>-Beta <span class="hlt">Plasmas</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Stenzel, R. L.</p> <p>2004-08-31</p> <p><span class="hlt">Plasmas</span> in which the kinetic energy exceeds the magnetic energy by a significant factor are common in space and in the laboratory. Such <span class="hlt">plasmas</span> can convect magnetic fields and create null points in whose vicinity first the ions become unmagnetized, then the <span class="hlt">electrons</span>. This project focuses on the detailed study of the transition regime of these <span class="hlt">plasmas</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19740002320','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19740002320"><span>The 3 DLE instrument on ATS-5. [<span class="hlt">plasma</span> <span class="hlt">electron</span> counter</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Deforest, S. E.</p> <p>1973-01-01</p> <p>The performance and operation of the DLE <span class="hlt">plasma</span> <span class="hlt">electron</span> counter on board the ATS 5 are described. Two methods of data presentation, microfilm line plots and spectrograms, are discussed along with <span class="hlt">plasma</span> dynamics, <span class="hlt">plasma</span> flow velocity, electrostatic charging, and wave-particle interactions.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/1127069','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/1127069"><span>Vortex stabilized <span class="hlt">electron</span> beam compressed fusion grade <span class="hlt">plasma</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Hershcovitch, Ady</p> <p>2014-03-19</p> <p>Most inertial confinement fusion schemes are comprised of highly compressed dense <span class="hlt">plasmas</span>. Those schemes involve short, extremely high power, short pulses of beams (lasers, particles) applied to lower density <span class="hlt">plasmas</span> or solid pellets. An alternative approach could be to shoot an intense <span class="hlt">electron</span> beam through very dense, atmospheric pressure, vortex stabilized <span class="hlt">plasma</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/22412986','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/22412986"><span>Effects of nonthermal <span class="hlt">electrons</span> on <span class="hlt">plasma</span> expansion into vacuum</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Bennaceur-Doumaz, D. Bara, D.; Benkhelifa, E.; Djebli, M.</p> <p>2015-01-28</p> <p>The expansion of semi-infinite <span class="hlt">plasma</span> into vacuum is analyzed with a hydrodynamic model for cold ions assuming <span class="hlt">electrons</span> modelled by a kappa-type distribution. Similarly to Mora study of a <span class="hlt">plasma</span> expansion into vacuum [P. Mora, Phys. Rev. Lett. 90, 185002 (2003)], we formulated empirical expressions for the electric field strength, velocity, and position of the ion front in one-dimensional nonrelativistic, collisionless isothermally expanding <span class="hlt">plasma</span>. Analytic expressions for the maximum ion energy and the spectrum of the accelerated ions in the <span class="hlt">plasma</span> were derived and discussed to highlight the <span class="hlt">electron</span> nonthermal effects on enhancing the ion acceleration in <span class="hlt">plasma</span> expansion into vacuum.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/1233789','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/1233789"><span>Nonnuclear Nearly Free <span class="hlt">Electron</span> Conduction Channels Induced by Doping Charge in Nanotube–Molecular <span class="hlt">Sheet</span> Composites</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Zhao, Jin; Zheng, Qijing; Petek, Hrvoje; Yang, Jinlong</p> <p>2014-09-04</p> <p>Nearly free <span class="hlt">electron</span> (NFE) states with density maxima in nonnuclear (NN) voids may have remarkable <span class="hlt">electron</span> transport properties ranging from suppressed electron–phonon interaction to Wigner crystallization. Such NFE states, however, usually exist near the vacuum level, which makes them unsuitable for transport. Through first principles calculations on nanocomposites consisting of carbon nanotube (CNT) arrays sandwiched between boron nitride (BN) <span class="hlt">sheets</span>, we describe a stratagem for stabilizing the NN-NFE states to below the Fermi level. By doping the CNTs with negative charge, we establish Coulomb barriers at CNTs walls that, together with the insulating BN <span class="hlt">sheets</span>, define the transverse potentials of one-dimensional (1D) transport channels, which support the NN-NFE states.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/12906544','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/12906544"><span>Cohesive acceleration and focusing of relativistic <span class="hlt">electrons</span> in overdense <span class="hlt">plasma</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Yakimenko, V; Pogorelsky, I V; Pavlishin, I V; Ben-Zvi, I; Kusche, K; Eidelman, Yu; Hirose, T; Kumita, T; Kamiya, Y; Urakawa, J; Greenberg, B; Zigler, A</p> <p>2003-07-04</p> <p>We describe our studies of the generation of <span class="hlt">plasma</span> wake fields by a relativistic <span class="hlt">electron</span> bunch and of phasing between the longitudinal and transverse fields in the wake. The leading edge of the <span class="hlt">electron</span> bunch excites a high-amplitude <span class="hlt">plasma</span> wake inside the overdense <span class="hlt">plasma</span> column, and the acceleration and focusing wake fields are probed by the bunch tail. By monitoring the dependence of the acceleration upon the <span class="hlt">plasma</span>'s density, we approached the beam-matching condition and achieved an energy gain of 0.6 MeV over the 17 mm <span class="hlt">plasma</span> length, corresponding to an average acceleration gradient of 35 MeV/m. Wake-induced modulation in energy and angular divergence of the <span class="hlt">electron</span> bunch are mapped within a wide range of <span class="hlt">plasma</span> density. We confirm a theoretical prediction about the phase offset between the accelerating and focusing components of <span class="hlt">plasma</span> wake.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015JPhCS.591a2051V','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015JPhCS.591a2051V"><span>Generation And Applications Of <span class="hlt">Electron</span>-Beam <span class="hlt">Plasma</span> Flows</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Vasiliev, M. N.; Tun Win, Aung</p> <p>2015-03-01</p> <p><span class="hlt">Plasma</span> flows generated by continuous or interrupted injection of an <span class="hlt">electron</span> beam into subsonic or supersonic gaseous streams are considered. Liquid and powder spraying by the <span class="hlt">electron</span>-beam <span class="hlt">plasma</span> (EBP) flows is studied as a technique of the aerosol <span class="hlt">plasma</span> generation. A number of experimental setups generating both free <span class="hlt">plasma</span> jets and <span class="hlt">plasma</span> flows in channels are described. Examples of the EBP flows applications for industrial and aerospace technologies are given. The applications are shown to be based on unique properties of the EBP and its stability within very wide ranges of the <span class="hlt">plasma</span> generation conditions. Some applications of the Hybrid <span class="hlt">Plasma</span> (HP) generated by combined action of the <span class="hlt">electron</span> beam (EB) and intermittent gas discharge on flows of gaseous mixtures and aerosols are presented as well.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016JPhCS.769a2079S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016JPhCS.769a2079S"><span>Waves in relativistic <span class="hlt">electron</span> beam in low-density <span class="hlt">plasma</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Sheinman, I.; Sheinman (Chernenco, J.</p> <p>2016-11-01</p> <p>Waves in <span class="hlt">electron</span> beam in low-density <span class="hlt">plasma</span> are analyzed. The analysis is based on complete electrodynamics consideration. Dependencies of dispersion laws from system parameters are investigated. It is shown that when relativistic <span class="hlt">electron</span> beam is passed through low-density <span class="hlt">plasma</span> surface waves of two types may exist. The first type is a high frequency wave on a boundary between the beam and neutralization area and the second type wave is on the boundary between neutralization area and stationary <span class="hlt">plasma</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014AGUFMSM31D4221K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014AGUFMSM31D4221K"><span>Data-Model Comparisons of <span class="hlt">Plasma</span> <span class="hlt">Sheet</span> Ion Temperatures during Moderate Geomagnetic Storms</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Keesee, A. M.; Ilie, R.; Liemohn, M. W.; Trigo, B.; Robison, G.; Carr, J., Jr.</p> <p>2014-12-01</p> <p>Ion heating occurs during geomagnetic storms as a result of many physical processes, including magnetic reconnection and adiabatic heating. Ion temperatures calculated from TWINS energetic neutral atom (ENA) data provide a global view of regions of heated ions in the <span class="hlt">plasma</span> <span class="hlt">sheet</span>. Two storms of similar, moderate magnitude are analyzed, a coronal mass ejection (CME)-driven storm that occurred on 26 September 2011 and a high speed stream (HSS)-driven storm on 13 October 2012. We present a comparison of the ion temperatures during the storms to patterns observed in a superposed epoch analysis of ion temperatures [Keesee et al., 2013] and compare the October storm to a previously analyzed HSS-driven storm [Keesee et al., 2012]. We also present a comparison of observed ion temperatures to those calculated from a simulation of each storm using the Space Weather Modeling Framework, including the BATS-R-US MHD model coupled with the HEIDI inner magnetosphere model.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19880059340&hterms=balance+sheet+energy&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3Dbalance%2Bsheet%2Benergy','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19880059340&hterms=balance+sheet+energy&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3Dbalance%2Bsheet%2Benergy"><span>Magnetic field and particle pressure in the <span class="hlt">plasma</span> <span class="hlt">sheet</span> of Jupiter</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Lanzerotti, L. J.; Maclennan, C. G.; Broughton, J. N.; Venkatesan, D.; Lepping, R. P.</p> <p>1987-01-01</p> <p>The results of an analysis of the energetic particle and magnetic field data acquired by the Voyager 2 spacecraft at distances of about 40-70 Jupiter radii on the nightside of the planet are reported. As in a previous study of similar data at distances of greater than about 80 Jupiter radii, the energy densities of ions (primarily protons) is found to be sufficient to provide the diamagnetic depressions measured in the magnetic field intensity as the spacecraft made successive encounters with the nightside <span class="hlt">plasma</span> <span class="hlt">sheet</span>. There is some evidence that the percent contribution of the protons to the energy balance decreases with increasing distance from the planet over this radial interval, although this conclusion is dependent upon the assumption that the proton and heavier ion (oxygen) energy spectra are similar.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/5851622','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/5851622"><span>Computer simulations of electromagnetic ion instabilities in the <span class="hlt">plasma</span> <span class="hlt">sheet</span> boundary layer</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Gary, S.P.; Winske, D.</p> <p>1989-01-01</p> <p>Linear Vlasov dispersion theory and one-dimensional hybrid computer simulations are used to study electromagnetic instabilities driven by hot, anisotropic counterstreaming proton components which model those observed from ISEE in the <span class="hlt">plasma</span> <span class="hlt">sheet</span> boundary layer of the near-Earth magnetotail. The proton anisotropies lead to the ion cyclotron anisotropy instability, which saturates at a low level of fluctuating fields and yields only weak proton scattering. Modest increases of the proton/proton relative drift, which might correspond to deeper tail conditions, excite the proton/proton nonresistant instability which attains larger fluctuation levels and more strongly heats the protons. If a relatively dense oxygen ion component is also introduced, the ion/ion right-hand resonant instability is excited; the consequent pitch-angle scattering of the protons resembles that indicated in the ISEE data. 6 refs., 5 figs.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/1305900','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/1305900"><span>3D electrostatic gyrokinetic <span class="hlt">electron</span> and fully kinetic ion simulation of lower-hybrid drift instability of Harris current <span class="hlt">sheet</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Wang, Zhenyu; Lin, Yu; Wang, Xueyi; Tummel, Kurt; Chen, Liu</p> <p>2016-07-07</p> <p>The eigenmode stability properties of three-dimensional lower-hybrid-drift-instabilities (LHDI) in a Harris current <span class="hlt">sheet</span> with a small but finite guide magnetic field have been systematically studied by employing the gyrokinetic <span class="hlt">electron</span> and fully kinetic ion (GeFi) particle-in-cell (PIC) simulation model with a realistic ion-to-<span class="hlt">electron</span> mass ratio m<sub>i</sub>/m<sub>e</sub>. In contrast to the fully kinetic PIC simulation scheme, the fast <span class="hlt">electron</span> cyclotron motion and <span class="hlt">plasma</span> oscillations are systematically removed in the GeFi model, and hence one can employ the realistic m<sub>i</sub>/m<sub>e</sub>. The GeFi simulations are benchmarked against and show excellent agreement with both the fully kinetic PIC simulation and the analytical eigenmode theory. Our studies indicate that, for small wavenumbers, ky, along the current direction, the most unstable eigenmodes are peaked at the location where $\\vec{k}$• $\\vec{B}$ =0, consistent with previous analytical and simulation studies. Here, $\\vec{B}$ is the equilibrium magnetic field and $\\vec{k}$ is the wavevector perpendicular to the nonuniformity direction. As ky increases, however, the most unstable eigenmodes are found to be peaked at $\\vec{k}$ •$\\vec{B}$ ≠0. Additionally, the simulation results indicate that varying m<sub>i</sub>/m<sub>e</sub>, the current <span class="hlt">sheet</span> width, and the guide magnetic field can affect the stability of LHDI. Simulations with the varying mass ratio confirm the lower hybrid frequency and wave number scalings.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012AGUFMSH21A2193S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012AGUFMSH21A2193S"><span><span class="hlt">Electron</span> Acceleration in a Dynamically Evolved Current <span class="hlt">Sheet</span> of Solar Coronal Conditions</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Shaohua, Z.; Du, A.; Feng, X.</p> <p>2012-12-01</p> <p><span class="hlt">Electron</span> acceleration in a drastically evolved current <span class="hlt">sheet</span> of solar coronal conditions is investigated via the combined resistive Magnetohydrodynamics (MHD) and test particle approaches. With high magnetic Reynolds number, the long-thin current <span class="hlt">sheet</span> is tearing into a chain of magnetic islands, which grow in size and coalesce together. The acceleration of <span class="hlt">electrons</span> are explored in three typical evolvement phases: when several large magnetic islands are formed (phase1), two of them are approaching each other (phase2) and almost merging into a "monster" magnetic island (phase3). The results show that for all the three phases <span class="hlt">electrons</span> with an initially Maxwellian distribution evolve into a heavy-tailed distribution and more than 20% of the <span class="hlt">electrons</span> can be accelerated higher than 200 keV within 0.1 second and some of them can even be energized up to MeV ranges. Most of the energetic <span class="hlt">electrons</span> move around the magnetic islands in clockwise direction (anti-parallel to the magnetic field lines), drifting in the -Z direction. The energetic <span class="hlt">electrons</span> with 10 keV < Ek < 200 keV are located outside the magnetic separatrices, where parallel electric field (Ep) is small. The <span class="hlt">electrons</span> with 200 keV < Ek < 5000 keV are distributed inside the magnetic islands where Ep is moderate large but have complex structures. The <span class="hlt">electrons</span> with Ek > 5000 keV are located around the outer regions of the magnetic islands or at the core regions of the magnetic islands. Some of the most energetic <span class="hlt">electrons</span> even appear in the small secondary magnetic islands that are embedded in the diusion regions in between the magnetic islands. It is the trapping eect of the magnetic islands and the distributions of Ep that determine the acceleration processes and space distribution of the energetic <span class="hlt">electrons</span>.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li class="active"><span>15</span></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_15 --> <div id="page_16" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li class="active"><span>16</span></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="301"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016GSL.....3....1N','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016GSL.....3....1N"><span>Long-term variations in the <span class="hlt">plasma</span> <span class="hlt">sheet</span> ion composition and substorm occurrence over 23 years</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Nosé, Masahito</p> <p>2016-12-01</p> <p>The Geotail satellite has been operating for almost two solar cycles (~23 years) since its launch in July 1992. The satellite carries the energetic particle and ion composition (EPIC) instrument that measures the energetic ion flux (9.4-212 keV/e) and enables the investigation of long-term variations of the ion composition in the <span class="hlt">plasma</span> <span class="hlt">sheet</span> for solar cycles 22-24. From the statistical analysis of the EPIC data, we find that (1) the <span class="hlt">plasma</span> ion mass ( M) is approximately 1.1 amu during the solar minimum, whereas it increases to 1.5-2.7 amu during the solar maximum; (2) the increases in M seem to have two components: a raising of the baseline levels (~1.5 amu) and a large transient enhancement (~1.8-2.7 amu); (3) the baseline level change of M correlates well with the Mg II index, which is a good proxy for the solar extreme ultraviolet (EUV) or far ultraviolet (FUV) irradiance; and (4) the large transient enhancement of M is caused by strong magnetic storms. We also study the long-term variations of substorm occurrences in 1992-2015 that are evaluated with the number of Pi2 pulsations detected at the Kakioka observatory. The results suggest no clear correlation between the substorm occurrence and the Mg II index. Instead, when the substorms are classified into externally triggered events and non-triggered events, the number of the non-triggered events and the Mg II index are negatively correlated. We interpret these results that the increase in the solar EUV/FUV radiation enhances the supply of ionospheric ions (He+ and O+ ions) into the <span class="hlt">plasma</span> <span class="hlt">sheet</span> to increase M, and the large M may suppress spontaneous <span class="hlt">plasma</span> instabilities initiating substorms and decrease the number of the non-triggered substorms. The present analysis using the unprecedentedly long-term dataset covering ~23 years provides additional observational evidence that heavy ions work to prevent the occurrence of substorms.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/22218323','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/22218323"><span><span class="hlt">Plasma</span> response to <span class="hlt">electron</span> energy filter in large volume <span class="hlt">plasma</span> device</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Sanyasi, A. K.; Awasthi, L. M.; Mattoo, S. K.; Srivastava, P. K.; Singh, S. K.; Singh, R.; Kaw, P. K.</p> <p>2013-12-15</p> <p>An <span class="hlt">electron</span> energy filter (EEF) is embedded in the Large Volume <span class="hlt">Plasma</span> Device <span class="hlt">plasma</span> for carrying out studies on excitation of <span class="hlt">plasma</span> turbulence by a gradient in <span class="hlt">electron</span> temperature (ETG) described in the paper of Mattoo et al. [S. K. Mattoo et al., Phys. Rev. Lett. 108, 255007 (2012)]. In this paper, we report results on the response of the <span class="hlt">plasma</span> to the EEF. It is shown that inhomogeneity in the magnetic field of the EEF switches on several physical phenomena resulting in <span class="hlt">plasma</span> regions with different characteristics, including a <span class="hlt">plasma</span> region free from energetic <span class="hlt">electrons</span>, suitable for the study of ETG turbulence. Specifically, we report that localized structures of <span class="hlt">plasma</span> density, potential, <span class="hlt">electron</span> temperature, and <span class="hlt">plasma</span> turbulence are excited in the EEF <span class="hlt">plasma</span>. It is shown that structures of <span class="hlt">electron</span> temperature and potential are created due to energy dependence of the <span class="hlt">electron</span> transport in the filter region. On the other hand, although structure of <span class="hlt">plasma</span> density has origin in the particle transport but two distinct steps of the density structure emerge from dominance of collisionality in the source-EEF region and of the Bohm diffusion in the EEF-target region. It is argued and experimental evidence is provided for existence of drift like flute Rayleigh-Taylor in the EEF <span class="hlt">plasma</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017PhRvE..95a3211R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017PhRvE..95a3211R"><span>Dense <span class="hlt">plasma</span> heating by crossing relativistic <span class="hlt">electron</span> beams</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ratan, N.; Sircombe, N. J.; Ceurvorst, L.; Sadler, J.; Kasim, M. F.; Holloway, J.; Levy, M. C.; Trines, R.; Bingham, R.; Norreys, P. A.</p> <p>2017-01-01</p> <p>Here we investigate, using relativistic fluid theory and Vlasov-Maxwell simulations, the local heating of a dense <span class="hlt">plasma</span> by two crossing <span class="hlt">electron</span> beams. Heating occurs as an instability of the <span class="hlt">electron</span> beams drives Langmuir waves, which couple nonlinearly into damped ion-acoustic waves. Simulations show a factor 2.8 increase in <span class="hlt">electron</span> kinetic energy with a coupling efficiency of 18%. Our results support applications to the production of warm dense matter and as a driver for inertial fusion <span class="hlt">plasmas</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/28208312','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/28208312"><span>Dense <span class="hlt">plasma</span> heating by crossing relativistic <span class="hlt">electron</span> beams.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Ratan, N; Sircombe, N J; Ceurvorst, L; Sadler, J; Kasim, M F; Holloway, J; Levy, M C; Trines, R; Bingham, R; Norreys, P A</p> <p>2017-01-01</p> <p>Here we investigate, using relativistic fluid theory and Vlasov-Maxwell simulations, the local heating of a dense <span class="hlt">plasma</span> by two crossing <span class="hlt">electron</span> beams. Heating occurs as an instability of the <span class="hlt">electron</span> beams drives Langmuir waves, which couple nonlinearly into damped ion-acoustic waves. Simulations show a factor 2.8 increase in <span class="hlt">electron</span> kinetic energy with a coupling efficiency of 18%. Our results support applications to the production of warm dense matter and as a driver for inertial fusion <span class="hlt">plasmas</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014PhDT.......212C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014PhDT.......212C"><span>Field Emission Properties of Carbon Nanotube Fibers and <span class="hlt">Sheets</span> for a High Current <span class="hlt">Electron</span> Source</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Christy, Larry</p> <p></p> <p>Field emission (FE) properties of carbon nanotube (CNT) fibers from Rice University and the University of Cambridge have been studied for use within a high current <span class="hlt">electron</span> source for a directed energy weapon. Upon reviewing the performance of these two prevalent CNT fibers, cathodes were designed with CNT fibers from the University of Cincinnati Nanoworld Laboratory. Cathodes composed of a single CNT fiber, an array of three CNT fibers, and a nonwoven CNT <span class="hlt">sheet</span> were investigated for FE properties; the goal was to design a cathode with emission current in excess of 10 mA. Once the design phase was complete, the cathode samples were fabricated, characterized, and then analyzed to determine FE properties. Electrical conductivity of the CNT fibers was characterized with a 4-probe technique. FE characteristics were measured in an ultra-high vacuum chamber at Wright-Patterson Air Force Base. The arrayed CNT fiber and the enhanced nonwoven CNT <span class="hlt">sheet</span> emitter design demonstrated the most promising FE properties. Future work will include further analysis and cathode design using this nonwoven CNT <span class="hlt">sheet</span> material to increase peak current performance during <span class="hlt">electron</span> emission.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/1235552','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/1235552"><span>Public Data Set: Impedance of an Intense <span class="hlt">Plasma</span>-Cathode <span class="hlt">Electron</span> Source for Tokamak <span class="hlt">Plasma</span> Startup</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Hinson, Edward T.; Barr, Jayson L.; Bongard, Michael W.; Burke, Marcus G.; Fonck, Raymond J.; Perry, Justin M.</p> <p>2016-05-31</p> <p>This data set contains openly-documented, machine readable digital research data corresponding to figures published in E.T. Hinson et al., 'Impedance of an Intense <span class="hlt">Plasma</span>-Cathode <span class="hlt">Electron</span> Source for Tokamak <span class="hlt">Plasma</span> Startup,' Physics of <span class="hlt">Plasmas</span> 23, 052515 (2016).</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/22490697','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/22490697"><span>Progress toward positron-<span class="hlt">electron</span> pair <span class="hlt">plasma</span> experiments</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Stenson, E. V.; Stanja, J.; Hergenhahn, U.; Saitoh, H.; Niemann, H.; Pedersen, T. Sunn; Marx, G. H.; Schweikhard, L.; Danielson, J. R.; Surko, C. M.; Hugenschmidt, C.</p> <p>2015-06-29</p> <p><span class="hlt">Electron</span>-positron <span class="hlt">plasmas</span> have been of theoretical interest for decades, due to the unique <span class="hlt">plasma</span> physics that arises from all charged particles having precisely identical mass. It is only recently, though, that developments in non-neutral <span class="hlt">plasma</span> physics (both in linear and toroidal geometries) and in the flux of sources for cold positrons have brought the goal of conducting <span class="hlt">electron</span>-positron pair <span class="hlt">plasma</span> experiments within reach. The APEX/PAX collaboration is working on a number of projects in parallel toward that goal; this paper provides an overview of recent, current, and upcoming activities.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19920041915&hterms=cps&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D60%26Ntt%3Dcps','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19920041915&hterms=cps&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D60%26Ntt%3Dcps"><span>Electrostatic turbulence in the earth's central <span class="hlt">plasma</span> <span class="hlt">sheet</span> produced by multiple-ring ion distributions</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Huba, J. D.; Chen, J.; Anderson, R. R.</p> <p>1992-01-01</p> <p>Attention is given to a mechanism to generate a broad spectrum of electrostatic turbulence in the quiet time central <span class="hlt">plasma</span> <span class="hlt">sheet</span> (CPS) <span class="hlt">plasma</span>. It is shown theoretically that multiple-ring ion distributions can generate short-wavelength (less than about 1), electrostatic turbulence with frequencies less than about kVj, where Vj is the velocity of the jth ring. On the basis of a set of parameters from measurements made in the CPS, it is found that electrostatic turbulence can be generated with wavenumbers in the range of 0.02 and 1.0, with real frequencies in the range of 0 and 10, and with linear growth rates greater than 0.01 over a broad range of angles relative to the magnetic field (5-90 deg). These theoretical results are compared with wave data from ISEE 1 using an ion distribution function exhibiting multiple-ring structures observed at the same time. The theoretical results in the linear regime are found to be consistent with the wave data.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/21532014','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/21532014"><span>Linear analysis of a rectangular waveguide cyclotron maser with a <span class="hlt">sheet</span> <span class="hlt">electron</span> beam</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Zhao Ding; Ding Yaogen; Wang Yong; Ruan Cunjun</p> <p>2010-11-15</p> <p>A linear theory for a rectangular waveguide cyclotron maser with a <span class="hlt">sheet</span> <span class="hlt">electron</span> beam is developed by using the Laplace transformation approach. This theory can be applied to any TE{sub mn} rectangular waveguide mode. The corresponding equations for the TM{sub mn} mode in the rectangular waveguide are also derived as a useful reference. Especially, the effect from the coupling between degenerate modes, which is induced by the nonideal rectangular waveguide walls, on the dispersion relation is considered in order to provide a more accurate model for the real devices. Through numerical calculations, the linear growth rate, launching loss, and spontaneous oscillations (caused by the absolute instability and backward wave oscillation) of this new structure can be analyzed in detail. It is worthwhile to point out that the operation at higher power levels of the rectangular waveguide <span class="hlt">sheet</span> beam system is possible.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3435554','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3435554"><span>A novel biotinylated lipid raft reporter for <span class="hlt">electron</span> microscopic imaging of <span class="hlt">plasma</span> membrane microdomains[S</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Krager, Kimberly J.; Sarkar, Mitul; Twait, Erik C.; Lill, Nancy L.; Koland, John G.</p> <p>2012-01-01</p> <p>The submicroscopic spatial organization of cell surface receptors and <span class="hlt">plasma</span> membrane signaling molecules is readily characterized by <span class="hlt">electron</span> microscopy (EM) via immunogold labeling of <span class="hlt">plasma</span> membrane <span class="hlt">sheets</span>. Although various signaling molecules have been seen to segregate within <span class="hlt">plasma</span> membrane microdomains, the biochemical identity of these microdomains and the factors affecting their formation are largely unknown. Lipid rafts are envisioned as submicron membrane subdomains of liquid ordered structure with differing lipid and protein constituents that define their specific varieties. To facilitate EM investigation of inner leaflet lipid rafts and the localization of membrane proteins therein, a unique genetically encoded reporter with the dually acylated raft-targeting motif of the Lck kinase was developed. This reporter, designated Lck-BAP-GFP, incorporates green fluorescent protein (GFP) and biotin acceptor peptide (BAP) modules, with the latter allowing its single-step labeling with streptavidin-gold. Lck-BAP-GFP was metabolically biotinylated in mammalian cells, distributed into low-density detergent-resistant membrane fractions, and was readily detected with avidin-based reagents. In EM images of <span class="hlt">plasma</span> membrane <span class="hlt">sheets</span>, the streptavidin-gold-labeled reporter was clustered in 20–50 nm microdomains, presumably representative of inner leaflet lipid rafts. The utility of the reporter was demonstrated in an investigation of the potential lipid raft localization of the epidermal growth factor receptor. PMID:22822037</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/22822037','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/22822037"><span>A novel biotinylated lipid raft reporter for <span class="hlt">electron</span> microscopic imaging of <span class="hlt">plasma</span> membrane microdomains.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Krager, Kimberly J; Sarkar, Mitul; Twait, Erik C; Lill, Nancy L; Koland, John G</p> <p>2012-10-01</p> <p>The submicroscopic spatial organization of cell surface receptors and <span class="hlt">plasma</span> membrane signaling molecules is readily characterized by <span class="hlt">electron</span> microscopy (EM) via immunogold labeling of <span class="hlt">plasma</span> membrane <span class="hlt">sheets</span>. Although various signaling molecules have been seen to segregate within <span class="hlt">plasma</span> membrane microdomains, the biochemical identity of these microdomains and the factors affecting their formation are largely unknown. Lipid rafts are envisioned as submicron membrane subdomains of liquid ordered structure with differing lipid and protein constituents that define their specific varieties. To facilitate EM investigation of inner leaflet lipid rafts and the localization of membrane proteins therein, a unique genetically encoded reporter with the dually acylated raft-targeting motif of the Lck kinase was developed. This reporter, designated Lck-BAP-GFP, incorporates green fluorescent protein (GFP) and biotin acceptor peptide (BAP) modules, with the latter allowing its single-step labeling with streptavidin-gold. Lck-BAP-GFP was metabolically biotinylated in mammalian cells, distributed into low-density detergent-resistant membrane fractions, and was readily detected with avidin-based reagents. In EM images of <span class="hlt">plasma</span> membrane <span class="hlt">sheets</span>, the streptavidin-gold-labeled reporter was clustered in 20-50 nm microdomains, presumably representative of inner leaflet lipid rafts. The utility of the reporter was demonstrated in an investigation of the potential lipid raft localization of the epidermal growth factor receptor.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1992AIPC..279..379J','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1992AIPC..279..379J"><span>Acceleration of injected <span class="hlt">electrons</span> by the <span class="hlt">plasma</span> beat wave accelerator</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Joshi, C.; Clayton, C. E.; Marsh, K. A.; Dyson, A.; Everett, M.; Lal, A.; Leemans, W. P.; Williams, R.; Katsouleas, T.; Mori, W. B.</p> <p>1992-07-01</p> <p>In this paper we describe the recent work at UCLA on the acceleration of externally injected <span class="hlt">electrons</span> by a relativistic <span class="hlt">plasma</span> wave. A two frequency laser was used to excite a <span class="hlt">plasma</span> wave over a narrow range of static gas pressures close to resonance. <span class="hlt">Electrons</span> with energies up to our detection limit of 9.1 MeV were observed when 2.1 MeV <span class="hlt">electrons</span> were injected in the <span class="hlt">plasma</span> wave. No accelerated <span class="hlt">electrons</span> above the detection threshold were observed when the laser was operated on a single frequency or when no <span class="hlt">electrons</span> were injected. Experimental results are compared with theoretical predictions, and future prospects for the <span class="hlt">plasma</span> beat wave accelerator are discussed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/22252089','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/22252089"><span>Solitary and shock waves in magnetized <span class="hlt">electron</span>-positron <span class="hlt">plasma</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Lu, Ding; Li, Zi-Liang; Abdukerim, Nuriman; Xie, Bai-Song</p> <p>2014-02-15</p> <p>An Ohm's law for <span class="hlt">electron</span>-positron (EP) <span class="hlt">plasma</span> is obtained. In the framework of EP magnetohydrodynamics, we investigate nonrelativistic nonlinear waves' solutions in a magnetized EP <span class="hlt">plasma</span>. In the collisionless limit, quasistationary propagating solitary wave structures for the magnetic field and the <span class="hlt">plasma</span> density are obtained. It is found that the wave amplitude increases with the Mach number and the Alfvén speed. However, the dependence on the <span class="hlt">plasma</span> temperature is just the opposite. Moreover, for a cold EP <span class="hlt">plasma</span>, the existence range of the solitary waves depends only on the Alfvén speed. For a hot EP <span class="hlt">plasma</span>, the existence range depends on the Alfvén speed as well as the <span class="hlt">plasma</span> temperature. In the presence of collision, the electromagnetic fields and the <span class="hlt">plasma</span> density can appear as oscillatory shock structures because of the dissipation caused by the collisions. As the collision frequency increases, the oscillatory shock structure becomes more and more monotonic.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19850051341&hterms=balsiger&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3Dbalsiger','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19850051341&hterms=balsiger&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3Dbalsiger"><span>Cold streams of ionospheric oxygen in the <span class="hlt">plasma</span> <span class="hlt">sheet</span> during the CDAW 6 event of March 22, 1979</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Orsini, S.; Amata, E.; Candidi, M.; Balsiger, H.; Stokholm, M.; Huang, C.; Lennartsson, W.; Lindqvist, P.-A.</p> <p>1985-01-01</p> <p>During magnetospheric substorm events, the <span class="hlt">plasma</span> and ion composition experiments in the ISEE-1 and 2 satellites detected cold ionospheric O+ streams, moving tailwards in the near earth magnetotail. Flow is parallel to the magnetic field lines, with drift velocity in agreement with the electric field topology obtained by mapping the model ionospheric field along the magnetic field lines. Fluctuations of the flow velocity of the streams can be related to magnetotail movements. Oscillations of the flow direction and speed with periods ranging from 5 to 10 min that suggest the presence of waves are observed. The streams are observed at all distances between 15 and 6 Re from the earth. When averaged over 360 deg, the streams show up as a low energy peak, superimposed on the distribution of isotropic <span class="hlt">plasma</span> <span class="hlt">sheet</span> ions. This double-peak structure of the energy spectrum seems typical of the disturbed <span class="hlt">plasma</span> <span class="hlt">sheet</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/6098783','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/6098783"><span>Cold streams of ionospheric oxygen in the <span class="hlt">plasma</span> <span class="hlt">sheet</span> during the CDAW 6 event of March 22, 1979</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Orsini, S.; Amata, E.; Candidi, M.; Balsiger, H.; Stokholm, M.; Huang, C.; Lennartsson, W.; Lindqvist, P.A.</p> <p>1985-05-01</p> <p>During magnetospheric substorm events, the <span class="hlt">plasma</span> and ion composition experiments in the ISEE-1 and 2 satellites detected cold ionospheric O+ streams, moving tailwards in the near earth magnetotail. Flow is parallel to the magnetic field lines, with drift velocity in agreement with the electric field topology obtained by mapping the model ionospheric field along the magnetic field lines. Fluctuations of the flow velocity of the streams can be related to magnetotail movements. Oscillations of the flow direction and speed with periods ranging from 5 to 10 min that suggest the presence of waves are observed. The streams are observed at all distances between 15 and 6 Re from the earth. When averaged over 360 deg, the streams show up as a low energy peak, superimposed on the distribution of isotropic <span class="hlt">plasma</span> <span class="hlt">sheet</span> ions. This double-peak structure of the energy spectrum seems typical of the disturbed <span class="hlt">plasma</span> <span class="hlt">sheet</span>. 25 references.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19850004205','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19850004205"><span>Cold streams of ionospheric oxygen in the <span class="hlt">plasma</span> <span class="hlt">sheet</span> during the CDAW-6 event of March 22, 1979</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Orsini, S.; Amata, E.; Candidi, M.; Balsiger, H.; Stokholm, M.; Huang, C. Y.; Lennartsson, W.; Lindqvist, P. A.</p> <p>1983-01-01</p> <p>During magnetospheric substorm events, the <span class="hlt">plasma</span> and ion composition experiments in the ISEE-1 and 2 satellites detected cold ionospheric O+ streams, moving tailwards in the near Earth magnetotail. Flow is parallel to the magnetic field lines, with drift velocity in agreement with the electric field topology obtained by mapping the model ionospheric field along the magnetic field lines. Fluctuations of the flow velocity of the streams can be related to magnetotail movements. Oscillations of the flow direction and speed with periods ranging from 5 to 10 min that suggest the presence of waves are observed. The streams are observed at all distances between 15 and 6 Re from the Earth. When averaged over 360 deg, the streams show up as a low energy peak, superimposed on the distribution of isotropic <span class="hlt">plasma</span> <span class="hlt">sheet</span> ions. This double-peak structure of the energy spectrum seems typical of the disturbed <span class="hlt">plasma</span> <span class="hlt">sheet</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/5590978','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/5590978"><span>Potential applications of an <span class="hlt">electron</span> cyclotron resonance multicusp <span class="hlt">plasma</span> source</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Tsai, C.C.; Berry, L.A.; Gorbatkin, S.M.; Haselton, H.H.; Roberto, J.B.; Stirling, W.L.</p> <p>1989-01-01</p> <p>An <span class="hlt">electron</span> cyclotron resonance (ECR) multicusp plasmatron has been developed by feeding a multicusp bucket arc chamber with a compact ECR <span class="hlt">plasma</span> source. This novel source produced large (about 25-cm-diam), uniform (to within {plus minus}10%), dense (>10{sup 11}-cm{sup -3}) <span class="hlt">plasmas</span> of argon, helium, hydrogen, and oxygen. It has been operated to produce an oxygen <span class="hlt">plasma</span> for etching 12.7-cm (5-in.) positive photoresist-coated silicon wafers with uniformity within {plus minus}8%. Results and potential applications of this new ECR <span class="hlt">plasma</span> source for <span class="hlt">plasma</span> processing of thin films are discussed. 21 refs., 10 figs.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19750022918','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19750022918"><span><span class="hlt">Electron</span> <span class="hlt">plasma</span> oscillations associated with type 3 radio emissions and solar <span class="hlt">electrons</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Gurnett, D. A.; Frank, L. A.</p> <p>1975-01-01</p> <p>An extensive study of the IMP-6 and IMP-8 <span class="hlt">plasma</span> and radio wave data was performed to try to find <span class="hlt">electron</span> <span class="hlt">plasma</span> oscillations associated with type III radio noise bursts and low-energy solar <span class="hlt">electrons</span>. It is shown that <span class="hlt">electron</span> <span class="hlt">plasma</span> oscillations are seldom observed in association with solar <span class="hlt">electron</span> events and type III radio bursts at 1.0 AU. For the one case in which <span class="hlt">electron</span> <span class="hlt">plasma</span> oscillations are definitely produced by the <span class="hlt">electrons</span> ejected by the solar flare the electric field strength is relatively small. Electromagnetic radiation, believed to be similar to the type III radio emission, is observed coming from the region of the more intense <span class="hlt">electron</span> <span class="hlt">plasma</span> oscillations upstream. Quantitative calculations of the rate of conversion of the <span class="hlt">plasma</span> oscillation energy to electromagnetic radiation are presented for <span class="hlt">plasma</span> oscillations excited by both solar <span class="hlt">electrons</span> and <span class="hlt">electrons</span> from the bow shock. These calculations show that neither the type III radio emissions nor the radiation from upstream of the bow shock can be adequately explained by a current theory for the coupling of <span class="hlt">electron</span> <span class="hlt">plasma</span> oscillations to electromagnetic radiation.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016APS..DPPCO5001B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016APS..DPPCO5001B"><span><span class="hlt">Electron</span> Temperature and <span class="hlt">Plasma</span> Flow Measurements of NIF Hohlraum <span class="hlt">Plasmas</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Barrios, M. A.; Liedahl, D. A.; Schneider, M. B.; Jones, O.; Brow, G. V.; Regan, S. P.; Fournier, K. B.; Moore, A. S.; Ross, J. S.; Eder, D.; Landen, O.; Kauffman, R. L.; Nikroo, A.; Kroll, J.; Jaquez, J.; Huang, H.; Hansen, S. B.; Callahan, D. A.; Hinkel, D. E.; Bradley, D.; Moody, J. D.; LLNL Collaboration; LLE Collaboration; GA Collaboration; SNL Collaboration</p> <p>2016-10-01</p> <p>Characterizing the <span class="hlt">plasma</span> conditions inside NIF hohlraums, in particular mapping the <span class="hlt">plasma</span> Te, is critical to gaining insight into mechanisms that affect energy coupling and transport in the hohlraum. The dot spectroscopy platform provides a temporal history of the localized Te and <span class="hlt">plasma</span> flow inside a NIF hohlraum, by introducing a Mn-Co tracer dot, at strategic locations inside the hohlraum, that comes to equilibrium with the local <span class="hlt">plasma</span>. K-shell X-ray spectroscopy of the tracer dot is recorded onto an absolutely calibrated X-ray streak spectrometer. Isoelectronic and interstage line ratios are used to infer localized Te through comparison with atomic physics calculations using SCRAM. Time resolved X-ray images are simultaneously taken of the expanding dot, providing <span class="hlt">plasma</span> (ion) flow information. We present recent results provided by this platform and compare with simulations using HYDRA. This work was performed under the auspices of the U.S. Department of Energy by LLNL under Contract DE-AC52-07NA27344.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/22489826','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/22489826"><span>Energy exchange in strongly coupled <span class="hlt">plasmas</span> with <span class="hlt">electron</span> drift</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Akbari-Moghanjoughi, M.; Ghorbanalilu, M.</p> <p>2015-11-15</p> <p>In this paper, the generalized viscoelastic collisional quantum hydrodynamic model is employed in order to investigate the linear dielectric response of a quantum <span class="hlt">plasma</span> in the presence of strong <span class="hlt">electron</span>-beam <span class="hlt">plasma</span> interactions. The generalized Chandrasekhar's relativistic degeneracy pressure together with the <span class="hlt">electron</span>-exchange and Coulomb interaction effects are taken into account in order to extend current research to a wide range of <span class="hlt">plasma</span> number density relevant to big planetary cores and astrophysical compact objects. The previously calculated shear viscosity and the <span class="hlt">electron</span>-ion collision frequencies are used for strongly coupled ion fluid. The effect of the <span class="hlt">electron</span>-beam velocity on complex linear dielectric function is found to be profound. This effect is clearly interpreted in terms of the wave-particle interactions and their energy-exchange according to the sign of the imaginary dielectric function, which is closely related to the wave attenuation coefficient in <span class="hlt">plasmas</span>. Such kinetic effect is also shown to be in close connection with the stopping power of a charged-particle beam in a quantum <span class="hlt">plasma</span>. The effect of many independent <span class="hlt">plasma</span> parameters, such as the ion charge-state, <span class="hlt">electron</span> beam-velocity, and relativistic degeneracy, is shown to be significant on the growing/damping of <span class="hlt">plasma</span> instability or energy loss/gain of the <span class="hlt">electron</span>-beam.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li class="active"><span>16</span></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_16 --> <div id="page_17" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li class="active"><span>17</span></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="321"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19880007150','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19880007150"><span>Relativistic electromagnetic waves in an <span class="hlt">electron</span>-ion <span class="hlt">plasma</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Chian, Abraham C.-L.; Kennel, Charles F.</p> <p>1987-01-01</p> <p>High power laser beams can drive <span class="hlt">plasma</span> particles to relativistic energies. An accurate description of strong waves requires the inclusion of ion dynamics in the analysis. The equations governing the propagation of relativistic electromagnetic waves in a cold <span class="hlt">electron</span>-ion <span class="hlt">plasma</span> can be reduced to two equations expressing conservation of energy-momentum of the system. The two conservation constants are functions of the <span class="hlt">plasma</span> stream velocity, the wave velocity, the wave amplitude, and the <span class="hlt">electron</span>-ion mass ratio. The dynamic parameter, expressing <span class="hlt">electron</span>-ion momentum conversation in the laboratory frame, can be regarded as an adjustable quantity, a suitable choice of which will yield self-consistent solutions when other <span class="hlt">plasma</span> parameters were specified. Circularly polarized electromagnetic waves and electrostatic <span class="hlt">plasma</span> waves are used as illustrations.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016InJPh.tmp...35R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016InJPh.tmp...35R"><span>Arbitrary <span class="hlt">electron</span> acoustic waves in degenerate dense <span class="hlt">plasmas</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Rahman, Ata-ur; Mushtaq, A.; Qamar, A.; Neelam, S.</p> <p>2016-12-01</p> <p>A theoretical investigation is carried out of the nonlinear dynamics of <span class="hlt">electron</span>-acoustic waves in a collisionless and unmagnetized <span class="hlt">plasma</span> whose constituents are non-degenerate cold <span class="hlt">electrons</span>, ultra-relativistic degenerate <span class="hlt">electrons</span>, and stationary ions. A dispersion relation is derived for linear EAWs. An energy integral equation involving the Sagdeev potential is derived, and basic properties of the large amplitude solitary structures are investigated in such a degenerate dense <span class="hlt">plasma</span>. It is shown that only negative large amplitude EA solitary waves can exist in such a <span class="hlt">plasma</span> system. The present analysis may be important to understand the collective interactions in degenerate dense <span class="hlt">plasmas</span>, occurring in dense astrophysical environments as well as in laser-solid density <span class="hlt">plasma</span> interaction experiments.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013NIMPA.720....7W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013NIMPA.720....7W"><span><span class="hlt">Electron</span> density measurements in the ITER fusion <span class="hlt">plasma</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Watts, Christopher; Udintsev, Victor; Andrew, Philip; Vayakis, George; Van Zeeland, Michael; Brower, David; Feder, Russell; Mukhin, Eugene; Tolstyakov, Sergey</p> <p>2013-08-01</p> <p>The operation of ITER requires high-quality estimates of the <span class="hlt">plasma</span> <span class="hlt">electron</span> density over multiple regions in the <span class="hlt">plasma</span> for <span class="hlt">plasma</span> evaluation, <span class="hlt">plasma</span> control and machine protection purposes. Although the density regimes of ITER are not very different from those of existing tokamaks (1018-1021 m-3), the severe conditions of the fusion <span class="hlt">plasma</span> environment present particular challenges to implementing these density diagnostics. In this paper we present an overview of the array of ITER <span class="hlt">electron</span> density diagnostics designed to measure over the entire ITER domain: <span class="hlt">plasma</span> core, pedestal, edge, scrape-off layer and divertor. It will focus on the challenges faced in making these measurements, and the technical solutions of the current designs.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19850035938&hterms=wilhelm&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D60%26Ntt%3Dwilhelm','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19850035938&hterms=wilhelm&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D60%26Ntt%3Dwilhelm"><span>Acceleration of <span class="hlt">electrons</span> in strong beam-<span class="hlt">plasma</span> interactions</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Wilhelm, K.; Bernstein, W.; Kellogg, P. J.; Whalen, B. A.</p> <p>1984-01-01</p> <p>The effects of strong beam-<span class="hlt">plasma</span> interactions on the <span class="hlt">electron</span> population of the upper atmosphere have been investigated in an <span class="hlt">electron</span> acceleration experiment performed with a sounding rocket. The rocket carried the Several Complex Experiments (SCEX) payload which included an <span class="hlt">electron</span> accelerator, three disposable 'throwaway' detectors (TADs), and a stepped <span class="hlt">electron</span> energy analyzer. The payload was launched in an auroral arc over the rocket at altitudes of 157 and 178 km, respectively. The performance characteristics of the instruments are discussed in detail. The data are combined with the results of laboratory measurements and show that <span class="hlt">electrons</span> with energies of at least two and probably four times the injection energy of 2 keV were observed during strong beam-<span class="hlt">plasma</span> interaction events. The interaction events occurred at pitch angles of 54 and 126 degrees. On the basis of the data it is proposed that the superenergization of the <span class="hlt">electrons</span> is correlated with the length of the beam-<span class="hlt">plasma</span> interaction region.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/22304083','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/22304083"><span>Nonlinear evolution of three-dimensional instabilities of thin and thick <span class="hlt">electron</span> scale current <span class="hlt">sheets</span>: Plasmoid formation and current filamentation</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Jain, Neeraj; Büchner, Jörg</p> <p>2014-07-15</p> <p>Nonlinear evolution of three dimensional <span class="hlt">electron</span> shear flow instabilities of an <span class="hlt">electron</span> current <span class="hlt">sheet</span> (ECS) is studied using <span class="hlt">electron</span>-magnetohydrodynamic simulations. The dependence of the evolution on current <span class="hlt">sheet</span> thickness is examined. For thin current <span class="hlt">sheets</span> (half thickness =d{sub e}=c/ω{sub pe}), tearing mode instability dominates. In its nonlinear evolution, it leads to the formation of oblique current channels. Magnetic field lines form 3-D magnetic spirals. Even in the absence of initial guide field, the out-of-reconnection-plane magnetic field generated by the tearing instability itself may play the role of guide field in the growth of secondary finite-guide-field instabilities. For thicker current <span class="hlt">sheets</span> (half thickness ∼5 d{sub e}), both tearing and non-tearing modes grow. Due to the non-tearing mode, current <span class="hlt">sheet</span> becomes corrugated in the beginning of the evolution. In this case, tearing mode lets the magnetic field reconnect in the corrugated ECS. Later thick ECS develops filamentary structures and turbulence in which reconnection occurs. This evolution of thick ECS provides an example of reconnection in self-generated turbulence. The power spectra for both the thin and thick current <span class="hlt">sheets</span> are anisotropic with respect to the <span class="hlt">electron</span> flow direction. The cascade towards shorter scales occurs preferentially in the direction perpendicular to the <span class="hlt">electron</span> flow.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016APS..GECHT6004K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016APS..GECHT6004K"><span>Generation of anomalously energetic suprathermal <span class="hlt">electrons</span> by an <span class="hlt">electron</span> beam interacting with a nonuniform <span class="hlt">plasma</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kaganovich, Igor; Sydorenko, Dmytro; Ventzek, Peter L. G.</p> <p>2016-09-01</p> <p><span class="hlt">Electrons</span> emitted from electrodes are accelerated by the sheath electric field and become the <span class="hlt">electron</span> beams penetrating the <span class="hlt">plasma</span>. The <span class="hlt">electron</span> beam can interact with the <span class="hlt">plasma</span> in collisionless manner via two-stream instability and produce suprathermal <span class="hlt">electrons</span>. In order to understand the mechanism of suprathermal <span class="hlt">electrons</span> acceleration, a beam-<span class="hlt">plasma</span> system was simulated using a 1D3V particle-in-cell code EDIPIC. These simulation results show that the acceleration may be caused by the effects related to the <span class="hlt">plasma</span> nonuniformity. The <span class="hlt">electron</span> beam excites <span class="hlt">plasma</span> waves whose wavelength and phase speed gradually decrease towards anode. The short waves near the anode accelerate <span class="hlt">plasma</span> bulk <span class="hlt">electrons</span> to suprathermal energies. Rich complexity of beam-<span class="hlt">plasma</span> interaction phenomena was also observed: intermittency and multiple regimes of two-stream instability in a dc discharge, band structure of the growth rate of the two-stream instability of an <span class="hlt">electron</span> beam propagating in a bounded <span class="hlt">plasma</span>, multi-stage acceleration of <span class="hlt">electrons</span> in a finite system. This research was funded by US Department of Energy.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016APS..DPPJ10168S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016APS..DPPJ10168S"><span>Generation of anomalously energetic suprathermal <span class="hlt">electrons</span> by an <span class="hlt">electron</span> beam interacting with a nonuniform <span class="hlt">plasma</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Sydorenko, Dmytro; Kaganovich, Igor D.; Ventzek, Peter L. G.</p> <p>2016-10-01</p> <p><span class="hlt">Electrons</span> emitted from electrodes are accelerated by the sheath electric field and become the <span class="hlt">electron</span> beams penetrating the <span class="hlt">plasma</span>. The <span class="hlt">electron</span> beam can interact with the <span class="hlt">plasma</span> in collisionless manner via two-stream instability and produce suprathermal <span class="hlt">electrons</span>. In order to understand the mechanism of suprathermal <span class="hlt">electrons</span> acceleration, a beam-<span class="hlt">plasma</span> system was simulated using a 1D3V particle-in-cell code EDIPIC. These simulation results show that the acceleration may be caused by the effects related to the <span class="hlt">plasma</span> nonuniformity. The <span class="hlt">electron</span> beam excites <span class="hlt">plasma</span> waves whose wavelength and phase speed gradually decrease towards anode. The short waves near the anode accelerate <span class="hlt">plasma</span> bulk <span class="hlt">electrons</span> to suprathermal energies. Rich complexity of beam- <span class="hlt">plasma</span> interaction phenomena was also observed: intermittency and multiple regimes of two-stream instability in a dc discharge, band structure of the growth rate of the two-stream instability of an <span class="hlt">electron</span> beam propagating in a bounded <span class="hlt">plasma</span>, multi-stage acceleration of <span class="hlt">electrons</span> in a finite system.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/962209','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/962209"><span>Gyrokinetic <span class="hlt">Electron</span> and Fully Kinetic Ion Particle Simulation of Collisionless <span class="hlt">Plasma</span> Dynamics</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Yu Lin; Xueyi Wang; Liu Chen; Zhihong Lin</p> <p>2009-08-11</p> <p>Fully kinetic-particle simulations and hybrid simulations have been utilized for decades to investigate various fundamental <span class="hlt">plasma</span> processes, such as magnetic reconnection, fast compressional waves, and wave-particle interaction. Nevertheless, due to disparate temporal and spatial scales between <span class="hlt">electrons</span> and ions, existing fully kinetic-particle codes have to employ either unrealistically high <span class="hlt">electron</span>-to-ion mass ratio, me/mi, or simulation domain limited to a few or a few ten's of the ion Larmor radii, or/and time much less than the global Alfven time scale in order to accommodate available computing resources. On the other hand, in the hybrid simulation, the ions are treated as fully kinetic particles but the <span class="hlt">electrons</span> are treated as a massless fluid. The <span class="hlt">electron</span> kinetic effects, e.g., wave-particle resonances and finite <span class="hlt">electron</span> Larmor radius effects, are completely missing. Important physics, such as the <span class="hlt">electron</span> transit time damping of fast compressional waves or the triggering mechanism of magnetic reconnection in collisionless <span class="hlt">plasmas</span> is absent in the hybrid codes. Motivated by these considerations and noting that dynamics of interest to us has frequencies lower than the <span class="hlt">electron</span> gyrofrequency, we planned to develop an innovative particle simulation model, gyrokinetic (GK) <span class="hlt">electrons</span> and fully kinetic (FK) ions. In the GK-<span class="hlt">electron</span> and FK-ion (GKe/FKi) particle simulation model, the rapid <span class="hlt">electron</span> cyclotron motion is removed, while keeping finite <span class="hlt">electron</span> Larmor radii, realistic me/mi ratio, wave-particle interactions, and off-diagonal components of <span class="hlt">electron</span> pressure tensor. The computation power can thus be significantly improved over that of the full-particle codes. As planned in the project DE-FG02-05ER54826, we have finished the development of the new GK-<span class="hlt">electron</span> and FK-ion scheme, finished its benchmark for a uniform <span class="hlt">plasma</span> in 1-D, 2-D, and 3-D systems against linear waves obtained from analytical theories, and carried out a further convergence test</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/22490693','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/22490693"><span>Annular vortex merging processes in non-neutral <span class="hlt">electron</span> <span class="hlt">plasmas</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Kaga, Chikato Ito, Kiyokazu; Higaki, Hiroyuki; Okamoto, Hiromi</p> <p>2015-06-29</p> <p>Non-neutral <span class="hlt">electron</span> <span class="hlt">plasmas</span> in a uniform magnetic field are investigated experimentally as a two dimensional (2D) fluid. Previously, it was reported that 2D phase space volume increases during a vortex merging process with viscosity. However, the measurement was restricted to a <span class="hlt">plasma</span> with a high density. Here, an alternative method is introduced to evaluate a similar process for a <span class="hlt">plasma</span> with a low density.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/22311133','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/22311133"><span><span class="hlt">Plasma</span> actuator <span class="hlt">electron</span> density measurement using microwave perturbation method</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Mirhosseini, Farid; Colpitts, Bruce</p> <p>2014-07-21</p> <p>A cylindrical dielectric barrier discharge <span class="hlt">plasma</span> under five different pressures is generated in an evacuated glass tube. This <span class="hlt">plasma</span> volume is located at the center of a rectangular copper waveguide cavity, where the electric field is maximum for the first mode and the magnetic field is very close to zero. The microwave perturbation method is used to measure <span class="hlt">electron</span> density and <span class="hlt">plasma</span> frequency for these five pressures. Simulations by a commercial microwave simulator are comparable to the experimental results.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017PhPl...24c3105X','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017PhPl...24c3105X"><span>A continuous-wave clinotron at 0.26 THz with <span class="hlt">sheet</span> <span class="hlt">electron</span> beam</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Xi, Hongzhu; He, Zhaochang; Wang, Jianguo; Li, Rong; Zhu, Gang; Chen, Zaigao; liu, Jinsong; Liu, Luwei; Wang, Hao</p> <p>2017-03-01</p> <p>A high performance continuous-wave (CW) clinotron with a <span class="hlt">sheet</span> <span class="hlt">electron</span> beam at 0.26 THz is presented in this paper. The mode selection is discussed by studying the dispersion curve of the high frequency structure, distribution of the electric field, coupling impedance, and particle-in-cell simulation result, showing that the designed clinotron operates in the fundamental mode TM10. The planar comb gratings are fabricated by using the wire electrical discharge machining technology with the processing error less than 0.005 mm. The <span class="hlt">electron</span> gun can provide the 2.5 mm × 0.14 mm <span class="hlt">sheet</span> <span class="hlt">electron</span> beam with a maximum current density of 57 A/cm2 at the CW mode. Experimental results show that the developed clinotron can operate at the fundamental mode TM10 and generate an output power of 820 mW at a frequency of 0.26 THz with a large frequency tuning range from 0.25 THz to 0.262 THz.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19720000562','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19720000562"><span>Measurement of <span class="hlt">electron</span> density and temperature in <span class="hlt">plasmas</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Billman, K. W.; Rowley, P. D.; Presley, L. L.; Stallcop, J.</p> <p>1972-01-01</p> <p>Application of two laser wavelengths passing through <span class="hlt">plasma</span> measures <span class="hlt">electron</span> density and temperature. Function depends on determining absorption of light at two wavelengths. Nature of reaction is explained and schematic diagram of equipment is included.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/950770','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/950770"><span>Ponderomotive Acceleration of Hot <span class="hlt">Electrons</span> in Tenuous <span class="hlt">Plasmas</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>V. I. Geyko; Fraiman, G. M.; Dodin, I. Y.; Fisch, N. J.</p> <p>2009-02-01</p> <p>The oscillation-center Hamiltonian is derived for a relativistic <span class="hlt">electron</span> injected with an arbitrary momentum in a linearly polarized laser pulse propagating in tenuous <span class="hlt">plasma</span>, assuming that the pulse length is smaller than the <span class="hlt">plasma</span> wavelength. For hot <span class="hlt">electrons</span> generated at collisions with ions under intense laser drive, multiple regimes of ponderomotive acceleration are identified and the laser dispersion is shown to affect the process at <span class="hlt">plasma</span> densities down to 1017 cm<sup>-3</sup>. Assuming a/Υg << 1, which prevents net acceleration of the cold <span class="hlt">plasma</span>, it is also shown that the normalized energy Υ of hot <span class="hlt">electrons</span> accelerated from the initial energy Υo < , Γ does not exceed Γ ~ aΥg, where a is the normalized laser field, and Υg is the group velocity Lorentz factor. Yet Υ ~ Γ is attained within a wide range of initial conditions; hence a cutoff in the hot <span class="hlt">electron</span> distribution is predicted.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4931469','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4931469"><span>Unexpected <span class="hlt">electronic</span> structure of the alloyed and doped arsenene <span class="hlt">sheets</span>: First-Principles calculations</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Liu, Ming-Yang; Huang, Yang; Chen, Qing-Yuan; Cao, Chao; He, Yao</p> <p>2016-01-01</p> <p>We study the equilibrium geometry and <span class="hlt">electronic</span> structure of alloyed and doped arsenene <span class="hlt">sheets</span> based on the density functional theory calculations. AsN, AsP and SbAs alloys possess indirect band gap and BiAs is direct band gap. Although AsP, SbAs and BiAs alloyed arsenene <span class="hlt">sheets</span> maintain the semiconducting character of pure arsenene, they have indirect-direct and semiconducting-metallic transitions by applying biaxial strain. We find that B- and N-doped arsenene render p-type semiconducting character, while C- and O-doped arsenene are metallic character. Especially, the C-doped arsenene is spin-polarization asymmetric and can be tuned into the bipolar spin-gapless semiconductor by the external electric field. Moreover, the doping concentration can effectively affect the magnetism of the C-doped system. Finally, we briefly study the chemical molecule adsorbed arsenene. Our results may be valuable for alloyed and doped arsenene <span class="hlt">sheets</span> applications in mechanical sensors and spintronic devices in the future. PMID:27373712</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016NatSR...629114L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016NatSR...629114L"><span>Unexpected <span class="hlt">electronic</span> structure of the alloyed and doped arsenene <span class="hlt">sheets</span>: First-Principles calculations</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Liu, Ming-Yang; Huang, Yang; Chen, Qing-Yuan; Cao, Chao; He, Yao</p> <p>2016-07-01</p> <p>We study the equilibrium geometry and <span class="hlt">electronic</span> structure of alloyed and doped arsenene <span class="hlt">sheets</span> based on the density functional theory calculations. AsN, AsP and SbAs alloys possess indirect band gap and BiAs is direct band gap. Although AsP, SbAs and BiAs alloyed arsenene <span class="hlt">sheets</span> maintain the semiconducting character of pure arsenene, they have indirect-direct and semiconducting-metallic transitions by applying biaxial strain. We find that B- and N-doped arsenene render p-type semiconducting character, while C- and O-doped arsenene are metallic character. Especially, the C-doped arsenene is spin-polarization asymmetric and can be tuned into the bipolar spin-gapless semiconductor by the external electric field. Moreover, the doping concentration can effectively affect the magnetism of the C-doped system. Finally, we briefly study the chemical molecule adsorbed arsenene. Our results may be valuable for alloyed and doped arsenene <span class="hlt">sheets</span> applications in mechanical sensors and spintronic devices in the future.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/24125367','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/24125367"><span>Negative <span class="hlt">plasma</span> potential relative to <span class="hlt">electron</span>-emitting surfaces.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Campanell, M D</p> <p>2013-09-01</p> <p>Most works on <span class="hlt">plasma</span>-wall interaction predict that with strong <span class="hlt">electron</span> emission, a nonmonotonic "space-charge-limited" (SCL) sheath forms where the <span class="hlt">plasma</span> potential is positive relative to the wall. We show that a fundamentally different sheath structure is possible where the potential monotonically increases toward a positively charged wall that is shielded by a single layer of negative charge. No ion-accelerating presheath exists in the <span class="hlt">plasma</span> and the ion wall flux is zero. An analytical solution of the "inverse sheath" regime is demonstrated for a general <span class="hlt">plasma</span>-wall system where the <span class="hlt">plasma</span> <span class="hlt">electrons</span> and emitted <span class="hlt">electrons</span> are Maxwellian with different temperatures. Implications of the inverse sheath effect are that (a) the <span class="hlt">plasma</span> potential is negative, (b) ion sputtering vanishes, (c) no charge is lost at the wall, and (d) the <span class="hlt">electron</span> energy flux is thermal. To test empirically what type of sheath structure forms under strong emission, a full <span class="hlt">plasma</span> bounded by strongly emitting walls is simulated. It is found that inverse sheaths form at the walls and ions are confined in the <span class="hlt">plasma</span>. This result differs from past particle-in-cell simulation studies of emission which contain an artificial "source sheath" that accelerates ions to the wall, leading to a SCL sheath at high emission intensity.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/9068','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/9068"><span>Accessibillity of <span class="hlt">Electron</span> Bernstein Modes in Over-Dense <span class="hlt">Plasma</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Batchelor, D.B.; Bigelow, T.S.; Carter, M.D.</p> <p>1999-04-12</p> <p>Mode-conversion between the ordinary, extraordinary and <span class="hlt">electron</span> Bernstein modes near the <span class="hlt">plasma</span> edge may allow signals generated by <span class="hlt">electrons</span> in an over-dense <span class="hlt">plasma</span> to be detected. Alternatively, high frequency power may gain accessibility to the core <span class="hlt">plasma</span> through this mode conversion process. Many of the tools used for ion cyclotron antenna de-sign can also be applied near the <span class="hlt">electron</span> cyclotron frequency. In this paper, we investigate the possibilities for an antenna that may couple to <span class="hlt">electron</span> Bernstein modes inside an over-dense <span class="hlt">plasma</span>. The optimum values for wavelengths that undergo mode-conversion are found by scanning the poloidal and toroidal response of the <span class="hlt">plasma</span> using a warm <span class="hlt">plasma</span> slab approximation with a sheared magnetic field. Only a very narrow region of the edge can be examined in this manner; however, ray tracing may be used to follow the mode converted power in a more general geometry. It is eventually hoped that the methods can be extended to a hot <span class="hlt">plasma</span> representation. Using antenna design codes, some basic antenna shapes will be considered to see what types of antennas might be used to detect or launch modes that penetrate the cutoff layer in the edge <span class="hlt">plasma</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015NatCo...6E7248R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015NatCo...6E7248R"><span>The solvation of <span class="hlt">electrons</span> by an atmospheric-pressure <span class="hlt">plasma</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Rumbach, Paul; Bartels, David M.; Sankaran, R. Mohan; Go, David B.</p> <p>2015-06-01</p> <p>Solvated <span class="hlt">electrons</span> are typically generated by radiolysis or photoionization of solutes. While <span class="hlt">plasmas</span> containing free <span class="hlt">electrons</span> have been brought into contact with liquids in studies dating back centuries, there has been little evidence that <span class="hlt">electrons</span> are solvated by this approach. Here we report direct measurements of solvated <span class="hlt">electrons</span> generated by an atmospheric-pressure <span class="hlt">plasma</span> in contact with the surface of an aqueous solution. The <span class="hlt">electrons</span> are measured by their optical absorbance using a total internal reflection geometry. The measured absorption spectrum is unexpectedly blue shifted, which is potentially due to the intense electric field in the interfacial Debye layer. We estimate an average penetration depth of 2.5+/-1.0 nm, indicating that the <span class="hlt">electrons</span> fully solvate before reacting through second-order recombination. Reactions with various <span class="hlt">electron</span> scavengers including H+, NO2-, NO3- and H2O2 show that the kinetics are similar, but not identical, to those for solvated <span class="hlt">electrons</span> formed in bulk water by radiolysis.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/22267801','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/22267801"><span>Study on <span class="hlt">electron</span> beam in a low energy <span class="hlt">plasma</span> focus</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Khan, Muhammad Zubair; Ling, Yap Seong; San, Wong Chiow</p> <p>2014-03-05</p> <p><span class="hlt">Electron</span> beam emission was investigated in a low energy <span class="hlt">plasma</span> focus device (2.2 kJ) using copper hollow anode. Faraday cup was used to estimate the energy of the <span class="hlt">electron</span> beam. XR100CR X-ray spectrometer was used to explore the impact of the <span class="hlt">electron</span> beam on the target observed from top-on and side-on position. Experiments were carried out at optimized pressure of argon gas. The impact of <span class="hlt">electron</span> beam is exceptionally notable with two different approaches using lead target inside hollow anode in our <span class="hlt">plasma</span> focus device.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016APS..DPPU10006E','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016APS..DPPU10006E"><span>Multicomponent <span class="hlt">plasma</span> expansion into vacuum with non-Maxwellian <span class="hlt">electrons</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Elkamash, Ibrahem; Kourakis, Ioannis</p> <p>2016-10-01</p> <p>The expansion of a collisionless <span class="hlt">plasma</span> into vacuum has been widely studied since the early works of Gurevich et al and Allen and coworkers. It has received momentum in recent years, in particular in the context of ultraintense laser pulse interaction with a solid target, in an effort to elucidate the generation of high energy ion beams. In most present day experiments, laser produced <span class="hlt">plasmas</span> contain several ion species, due to increasingly complicated composite targets. Anderson et al have studied the isothermal expansion of a two-ion-species <span class="hlt">plasma</span>. As in most earlier works, the <span class="hlt">electrons</span> were assumed to be isothermal throughout the expansion. However, in more realistic situations, the evolution of laser produced <span class="hlt">plasmas</span> into vacuum is mainly governed by nonthermal <span class="hlt">electrons</span>. These <span class="hlt">electrons</span> are characterized by particle distribution functions with high energy tails, which may significantly deviate from the Maxwellian distribution. In this paper, we present a theoretical model for <span class="hlt">plasma</span> expansion of two component <span class="hlt">plasma</span> with nonthermal <span class="hlt">electrons</span>, modelled by a kappa-type distribution. The superthermal effect on the ion density, velocity and the electric field is investigated. It is shown that energetic <span class="hlt">electrons</span> have a significant effecton the expansion dynamics of the <span class="hlt">plasma</span>. This work was supported from CPP/QUB funding. One of us (I.S. Elkamash) acknowledges financial support by an Egyptian Government fellowship.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li class="active"><span>17</span></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_17 --> <div id="page_18" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li class="active"><span>18</span></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="341"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016RScI...87kE401F','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016RScI...87kE401F"><span><span class="hlt">Plasma</span> characterization using ultraviolet Thomson scattering from ion-acoustic and <span class="hlt">electron</span> <span class="hlt">plasma</span> waves (invited)</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Follett, R. K.; Delettrez, J. A.; Edgell, D. H.; Henchen, R. J.; Katz, J.; Myatt, J. F.; Froula, D. H.</p> <p>2016-11-01</p> <p>Collective Thomson scattering is a technique for measuring the <span class="hlt">plasma</span> conditions in laser-<span class="hlt">plasma</span> experiments. Simultaneous measurements of ion-acoustic and <span class="hlt">electron</span> <span class="hlt">plasma</span>-wave spectra were obtained using a 263.25-nm Thomson-scattering probe beam. A fully reflective collection system was used to record light scattered from <span class="hlt">electron</span> <span class="hlt">plasma</span> waves at <span class="hlt">electron</span> densities greater than 1021 cm-3, which produced scattering peaks near 200 nm. An accurate analysis of the experimental Thomson-scattering spectra required accounting for <span class="hlt">plasma</span> gradients, instrument sensitivity, optical effects, and background radiation. Practical techniques for including these effects when fitting Thomson-scattering spectra are presented and applied to the measured spectra to show the improvements in <span class="hlt">plasma</span> characterization.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/968512','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/968512"><span>Properties of Trapped <span class="hlt">Electron</span> Bunches in a <span class="hlt">Plasma</span> Wakefield Accelerator</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Kirby, Neil; /SLAC</p> <p>2009-10-30</p> <p><span class="hlt">Plasma</span>-based accelerators use the propagation of a drive bunch through <span class="hlt">plasma</span> to create large electric fields. Recent <span class="hlt">plasma</span> wakefield accelerator (PWFA) experiments, carried out at the Stanford Linear Accelerator Center (SLAC), successfully doubled the energy for some of the 42 GeV drive bunch <span class="hlt">electrons</span> in less than a meter; this feat would have required 3 km in the SLAC linac. This dissertation covers one phenomenon associated with the PWFA, <span class="hlt">electron</span> trapping. Recently it was shown that PWFAs, operated in the nonlinear bubble regime, can trap <span class="hlt">electrons</span> that are released by ionization inside the <span class="hlt">plasma</span> wake and accelerate them to high energies. These trapped <span class="hlt">electrons</span> occupy and can degrade the accelerating portion of the <span class="hlt">plasma</span> wake, so it is important to understand their origins and how to remove them. Here, the onset of <span class="hlt">electron</span> trapping is connected to the drive bunch properties. Additionally, the trapped <span class="hlt">electron</span> bunches are observed with normalized transverse emittance divided by peak current, {epsilon}{sub N,x}/I{sub t}, below the level of 0.2 {micro}m/kA. A theoretical model of the trapped <span class="hlt">electron</span> emittance, developed here, indicates that the emittance scales inversely with the square root of the <span class="hlt">plasma</span> density in the non-linear 'bubble' regime of the PWFA. This model and simulations indicate that the observed values of {epsilon}{sub N,x}/I{sub t} result from multi-GeV trapped <span class="hlt">electron</span> bunches with emittances of a few {micro}m and multi-kA peak currents. These properties make the trapped <span class="hlt">electrons</span> a possible particle source for next generation light sources. This dissertation is organized as follows. The first chapter is an overview of the PWFA, which includes a review of the accelerating and focusing fields and a survey of the remaining issues for a <span class="hlt">plasma</span>-based particle collider. Then, the second chapter examines the physics of <span class="hlt">electron</span> trapping in the PWFA. The third chapter uses theory and simulations to analyze the properties of the trapped <span class="hlt">electron</span></p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012cosp...39..668G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012cosp...39..668G"><span>Effects of near-Earth magnetic reconnection simultaneously observed in the <span class="hlt">Plasma</span> <span class="hlt">Sheet</span> by Cluster and DSP spacecrafts</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Grigorenko, Elena; Zelenyi, Lev; Koleva, Rositza; Sauvaud, Jean-Andre</p> <p>2012-07-01</p> <p>Cluster and DSP fortunate locations in the Central <span class="hlt">Plasma</span> <span class="hlt">Sheet</span> (CPS) of magnetotail allowed studies of accelerated <span class="hlt">plasma</span> flows and currents observed in the tail and Earth side of near-Earth magnetic X-line located between the spacecrafts. The observed delays in registration of magnetic dipolarization fronts by DSP spacecraft and negative Bz enhancements by Cluster s/c provide an estimation of X-line location at ~-14 Re. Current <span class="hlt">Sheet</span> (CS) thinning (<0.17 Re)and bifurcation were clearly observed by Cluster s/c. An analysis of ion velocity distribution functions measured by both spacecrafts revealed that magnetic reconnection occurred at <span class="hlt">Plasma</span> <span class="hlt">Sheet</span> (PS) field lines and had a duration ~7 min. After cessation of acceleration process both spacecraft stay in the PS and do not observe any X-line manifestations. But after ~ 8 min Cluster and DSP again start to observe accelerated <span class="hlt">plasma</span> flows moving earthward at both locations. This indicates on restart of acceleration process in the source located already in more distant part of magnetotail. During the period of interest no geomagnetic activity was observed not only in values of geomagnetic indices (like AL and Kp) but also in behavior of onground magnetic field measured by stations located near the DSP projection onto ionosphere. The absence of geomagnetic manifestations of this event may be related with strong localization of reconnection region.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/6222898','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/6222898"><span>Association of an auroral surge with <span class="hlt">plasma</span> <span class="hlt">sheet</span> recovery and the retreat of the substorm neutral line</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Hones, E.W. ); Elphinstone, R.; Murphree, J.S. . Dept. of Physics); Galvin, A.B. . Dept. of Space Physics); Heinemann, N.C. . Dept. of Physics); Parks, G.K. ); Rich, F.J. (Air Force Geophysics Lab., Hanscom AFB, MA</p> <p>1990-01-01</p> <p>One of the periods being studied in the PROMIS CDAW (CDAW-9) workshops is the interval 0000-1200 UT on May 3, 1986, designated Event 9C.'' A well-defined substorm, starting at 0919 UT, was imaged by both DE 1 over the southern hemisphere and Viking over the northern hemisphere. The images from Viking, at 80-second time resolution, showed a surge-like feature forming at about 0952 UT at the poleward edge of the late evening sector of the oval. The feature remained relatively stationary until about 1000 UT when it seemed to start advancing westward. ISEE 1 and 2 were closely conjugate to the surge as mapped from both the DMSP and Viking images. We conclude that the <span class="hlt">plasma</span> <span class="hlt">sheet</span> recovery was occasioned by the arrival at ISEE 1,2 of a westward traveling wave of <span class="hlt">plasma</span> <span class="hlt">sheet</span> thickening, the wave itself being formed by westward progression of the substorm neutral line's tailward retreat. The westward traveling surge was the auroral manifestation of this nonuniform retreat of the neutral line. We suggest that the upward field aligned current measured by DMSP F7 above the surge head was driven by <span class="hlt">plasma</span> velocity shear in the <span class="hlt">plasma</span> <span class="hlt">sheet</span> at the duskward kink'' in the retreating neutral line. By analogy with this observation we propose that the westward traveling surges and the current wedge field aligned currents that characterize the expanding auroral bulge during substorm expansive phase are manifestations of (and are driven by) velocity shear in the <span class="hlt">plasma</span> <span class="hlt">sheet</span> near the ends of the extending substorm neutral line.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/5399267','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/5399267"><span>Measuring ionospheric <span class="hlt">electron</span> density using the <span class="hlt">plasma</span> frequency probe</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Jensen, M.D.; Baker, K.D. )</p> <p>1992-02-01</p> <p>During the past decade, the <span class="hlt">plasma</span> frequency probe (PFP) has evolved into an accurate, proven method of measuring <span class="hlt">electron</span> density in the ionosphere above about 90 km. The instrument uses an electrically short antenna mounted on a sounding rocket that is immersed in the <span class="hlt">plasma</span> and notes the frequency where the antenna impedance is large and nonreactive. This frequency is closely related to the <span class="hlt">plasma</span> frequency, which is a direct function of free <span class="hlt">electron</span> concentration. The probe uses phase-locked loop technology to follow a changing <span class="hlt">electron</span> density. Several sections of the <span class="hlt">plasma</span> frequency probe circuitry are unique, especially the voltage-controlled oscillator that uses both an <span class="hlt">electronically</span> tuned capacitor and inductor to give the wide tuning range needed for <span class="hlt">electron</span> density measurements. The results from two recent sounding rocket flights (Thunderstorm II and CRIT II) under vastly different <span class="hlt">plasma</span> conditions demonstrate the capabilities of the PFP and show the importance of in situ <span class="hlt">electron</span> density measurements of understanding <span class="hlt">plasma</span> processes. 9 refs.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/1061446','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/1061446"><span><span class="hlt">Electron</span> Beam Transport in Advanced <span class="hlt">Plasma</span> Wave Accelerators</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Williams, Ronald L</p> <p>2013-01-31</p> <p>The primary goal of this grant was to develop a diagnostic for relativistic <span class="hlt">plasma</span> wave accelerators based on injecting a low energy <span class="hlt">electron</span> beam (5-50keV) perpendicular to the <span class="hlt">plasma</span> wave and observing the distortion of the <span class="hlt">electron</span> beam's cross section due to the <span class="hlt">plasma</span> wave's electrostatic fields. The amount of distortion would be proportional to the <span class="hlt">plasma</span> wave amplitude, and is the basis for the diagnostic. The beat-wave scheme for producing <span class="hlt">plasma</span> waves, using two CO2 laser beam, was modeled using a leap-frog integration scheme to solve the equations of motion. Single <span class="hlt">electron</span> trajectories and corresponding phase space diagrams were generated in order to study and understand the details of the interaction dynamics. The <span class="hlt">electron</span> beam was simulated by combining thousands of single <span class="hlt">electrons</span>, whose initial positions and momenta were selected by random number generators. The model was extended by including the interactions of the <span class="hlt">electrons</span> with the CO2 laser fields of the beat wave, superimposed with the <span class="hlt">plasma</span> wave fields. The results of the model were used to guide the design and construction of a small laboratory experiment that may be used to test the diagnostic idea.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/22085998','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/22085998"><span>Oscillating <span class="hlt">plasma</span> bubbles. III. Internal <span class="hlt">electron</span> sources and sinks</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Stenzel, R. L.; Urrutia, J. M.</p> <p>2012-08-15</p> <p>An internal <span class="hlt">electron</span> source has been used to neutralize ions injected from an ambient <span class="hlt">plasma</span> into a spherical grid. The resultant <span class="hlt">plasma</span> is termed a <span class="hlt">plasma</span> 'bubble.' When the <span class="hlt">electron</span> supply from the filament is reduced, the sheath inside the bubble becomes unstable. The <span class="hlt">plasma</span> potential of the bubble oscillates near but below the ion <span class="hlt">plasma</span> frequency. Different modes of oscillations have been observed as well as a subharmonic and multiple harmonics. The frequency increases with ion density and decreases with <span class="hlt">electron</span> density. The peak amplitude occurs for an optimum current and the instability is quenched at large <span class="hlt">electron</span> densities. The frequency also increases if Langmuir probes inside the bubble draw <span class="hlt">electrons</span>. Allowing <span class="hlt">electrons</span> from the ambient <span class="hlt">plasma</span> to enter, the bubble changes the frequency dependence on grid voltage. It is concluded that the net space charge density in the sheath determines the oscillation frequency. It is suggested that the sheath instability is caused by ion inertia in an oscillating sheath electric field which is created by ion bunching.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/977229','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/977229"><span>Hybrid Simulation of Laser-<span class="hlt">Plasma</span> Interactions and Fast <span class="hlt">Electron</span> Transport in Inhomogeneous <span class="hlt">Plasma</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Cohen, B I; Kemp, A; Divol, L</p> <p>2009-05-27</p> <p>A new framework is introduced for kinetic simulation of laser-<span class="hlt">plasma</span> interactions in an inhomogenous <span class="hlt">plasma</span> motivated by the goal of performing integrated kinetic simulations of fast-ignition laser fusion. The algorithm addresses the propagation and absorption of an intense electromagnetic wave in an ionized <span class="hlt">plasma</span> leading to the generation and transport of an energetic <span class="hlt">electron</span> component. The energetic <span class="hlt">electrons</span> propagate farther into the <span class="hlt">plasma</span> to much higher densities where Coulomb collisions become important. The high-density <span class="hlt">plasma</span> supports an energetic <span class="hlt">electron</span> current, return currents, self-consistent electric fields associated with maintaining quasi-neutrality, and self-consistent magnetic fields due to the currents. Collisions of the <span class="hlt">electrons</span> and ions are calculated accurately to track the energetic <span class="hlt">electrons</span> and model their interactions with the background <span class="hlt">plasma</span>. Up to a density well above critical density, where the laser electromagnetic field is evanescent, Maxwell's equations are solved with a conventional particle-based, finite-difference scheme. In the higher-density <span class="hlt">plasma</span>, Maxwell's equations are solved using an Ohm's law neglecting the inertia of the background <span class="hlt">electrons</span> with the option of omitting the displacement current in Ampere's law. Particle equations of motion with binary collisions are solved for all <span class="hlt">electrons</span> and ions throughout the system using weighted particles to resolve the density gradient efficiently. The algorithm is analyzed and demonstrated in simulation examples. The simulation scheme introduced here achieves significantly improved efficiencies.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/21333915','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/21333915"><span>Simulation of laser-<span class="hlt">plasma</span> interactions and fast-<span class="hlt">electron</span> transport in inhomogeneous <span class="hlt">plasma</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Cohen, B.I. Kemp, A.J.; Divol, L.</p> <p>2010-06-20</p> <p>A new framework is introduced for kinetic simulation of laser-<span class="hlt">plasma</span> interactions in an inhomogeneous <span class="hlt">plasma</span> motivated by the goal of performing integrated kinetic simulations of fast-ignition laser fusion. The algorithm addresses the propagation and absorption of an intense electromagnetic wave in an ionized <span class="hlt">plasma</span> leading to the generation and transport of an energetic <span class="hlt">electron</span> component. The energetic <span class="hlt">electrons</span> propagate farther into the <span class="hlt">plasma</span> to much higher densities where Coulomb collisions become important. The high-density <span class="hlt">plasma</span> supports an energetic <span class="hlt">electron</span> current, return currents, self-consistent electric fields associated with maintaining quasi-neutrality, and self-consistent magnetic fields due to the currents. Collisions of the <span class="hlt">electrons</span> and ions are calculated accurately to track the energetic <span class="hlt">electrons</span> and model their interactions with the background <span class="hlt">plasma</span>. Up to a density well above critical density, where the laser electromagnetic field is evanescent, Maxwell's equations are solved with a conventional particle-based, finite-difference scheme. In the higher-density <span class="hlt">plasma</span>, Maxwell's equations are solved using an Ohm's law neglecting the inertia of the background <span class="hlt">electrons</span> with the option of omitting the displacement current in Ampere's law. Particle equations of motion with binary collisions are solved for all <span class="hlt">electrons</span> and ions throughout the system using weighted particles to resolve the density gradient efficiently. The algorithm is analyzed and demonstrated in simulation examples. The simulation scheme introduced here achieves significantly improved efficiencies.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016PhPl...23h2310S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016PhPl...23h2310S"><span><span class="hlt">Electron</span> acoustic solitary waves in a magnetized <span class="hlt">plasma</span> with nonthermal <span class="hlt">electrons</span> and an <span class="hlt">electron</span> beam</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Singh, S. V.; Devanandhan, S.; Lakhina, G. S.; Bharuthram, R.</p> <p>2016-08-01</p> <p>A theoretical investigation is carried out to study the obliquely propagating <span class="hlt">electron</span> acoustic solitary waves having nonthermal hot <span class="hlt">electrons</span>, cold and beam <span class="hlt">electrons</span>, and ions in a magnetized <span class="hlt">plasma</span>. We have employed reductive perturbation theory to derive the Korteweg-de-Vries-Zakharov-Kuznetsov (KdV-ZK) equation describing the nonlinear evolution of these waves. The two-dimensional plane wave solution of KdV-ZK equation is analyzed to study the effects of nonthermal and beam <span class="hlt">electrons</span> on the characteristics of the solitons. Theoretical results predict negative potential solitary structures. We emphasize that the inclusion of finite temperature effects reduces the soliton amplitudes and the width of the solitons increases by an increase in the obliquity of the wave propagation. The numerical analysis is presented for the parameters corresponding to the observations of "burst a" event by Viking satellite on the auroral field lines.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=20070017485&hterms=applied+behavior+analysis&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3Dapplied%2Bbehavior%2Banalysis','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20070017485&hterms=applied+behavior+analysis&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3Dapplied%2Bbehavior%2Banalysis"><span>Modeling the Self-organized Critical Behavior of Earth's <span class="hlt">Plasma</span> <span class="hlt">Sheet</span> Reconnection Dynamics</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Klimas, Alexander J.</p> <p>2006-01-01</p> <p>Analyses of Polar UVI auroral image data show that bright night-side high-latitude W emissions exhibit so many of the key properties of systems in self-organized criticality that an alternate interpretation has become virtually impossible. These analyses will be reviewed. It is now necessary to find and model the source of this behavior. We note that the most common models of self-organized criticality are numerical sandpiles. These are, at root, models that govern the transport of some quantity from a region where it is loaded to another where it is unloaded. Transport is enabled by the excitation of a local threshold instability; it is intermittent and bursty, and it exhibits a number of scale-free statistical properties. Searching for a system in the magnetosphere that is analogous and that, in addition, is known to produce auroral signatures, we focus on the reconnection dynamics of the magnetotail <span class="hlt">plasma</span> <span class="hlt">sheet</span>. In our previous work, a driven reconnection model has been constructed and has been under study. The transport of electromagnetic (primarily magnetic) energy carried by the Poynting flux into the reconnection region of the model has been examined. All of the analysis techniques (and more) that have been applied to the auroral image data have also been applied to this Poynting flux. New results will be presented showing that this model also exhibits so many of the key properties of systems in self-organized criticality that an alternate interpretation is implausible. A strong correlation between these key properties of the model and those of the auroral UV emissions will be demonstrated. We suggest that, in general, the driven reconnection model is an important step toward a realistic <span class="hlt">plasma</span> physical model of self-organized criticality and we conclude, more specifically, that it is also a step in the right direction toward modeling the multiscale reconnection dynamics of the magnetotail.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=20060013116&hterms=applied+behavior+analysis&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3Dapplied%2Bbehavior%2Banalysis','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20060013116&hterms=applied+behavior+analysis&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3Dapplied%2Bbehavior%2Banalysis"><span>Modeling the Self-organized Critical Behavior of the <span class="hlt">Plasma</span> <span class="hlt">Sheet</span> Reconnection Dynamics</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Klimas, Alex; Uritsky, Vadim; Baker, Daniel</p> <p>2006-01-01</p> <p>Analyses of Polar UVI auroral image data reviewed in our other presentation at this meeting (V. Uritsky, A. Klimas) show that bright night-side high-latitude UV emissions exhibit so many of the key properties of systems in self-organized criticality (SOC) that an alternate interpretation has become virtually impossible. It is now necessary to find and model the source of this behavior. We note that the most common models of self-organized criticality are numerical sandpiles. These are, at root, models that govern the transport of some quantity from a region where it is loaded to another where it is unloaded. Transport is enabled by the excitation of a local threshold instability; it is intermittent and bursty, and it exhibits a number of scale-free statistical properties. Searching for a system in the magnetosphere that is analogous and that, in addition, is known to produce auroral signatures, we focus on the reconnection dynamics of the <span class="hlt">plasma</span> <span class="hlt">sheet</span>. In our previous work, a driven reconnection model has been constructed and has been under study. The transport of electromagnetic (primarily magnetic) energy carried by the Poynting flux into the reconnection region of the model has been examined. All of the analysis techniques, and more, that have been applied to the auroral image data have also been applied to this Poynting flux. Here, we report new results showing that this model also exhibits so many of the key properties of systems in self-organized criticality that an alternate interpretation is implausible. Further, we find a strong correlation between these key properties of the model and those of the auroral UV emissions. We suggest that, in general, the driven reconnection model is an important step toward a realistic <span class="hlt">plasma</span> physical model of self-organized criticality and we conclude, more specifically, that it is also a step in the right direction toward modeling the multiscale reconnection dynamics of the magnetotail.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=20060009303&hterms=electric+current&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3Delectric%2Bcurrent','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20060009303&hterms=electric+current&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3Delectric%2Bcurrent"><span>Cluster electric current density measurements within a magnetic flux rope in the <span class="hlt">plasma</span> <span class="hlt">sheet</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Slavin, J. A.; Lepping, R. P.; Gjerloev, J.; Goldstein, M. L.; Fairfield, D. H.; Acuna, M. H.; Balogh, A.; Dunlop, M.; Kivelson, M. G.; Khurana, K.</p> <p>2003-01-01</p> <p>On August 22, 2001 all 4 Cluster spacecraft nearly simultaneously penetrated a magnetic flux rope in the tail. The flux rope encounter took place in the central <span class="hlt">plasma</span> <span class="hlt">sheet</span>, Beta(sub i) approx. 1-2, near the leading edge of a bursty bulk flow. The "time-of-flight" of the flux rope across the 4 spacecraft yielded V(sub x) approx. 700 km/s and a diameter of approx.1 R(sub e). The speed at which the flux rope moved over the spacecraft is in close agreement with the Cluster <span class="hlt">plasma</span> measurements. The magnetic field profiles measured at each spacecraft were first modeled separately using the Lepping-Burlaga force-free flux rope model. The results indicated that the center of the flux rope passed northward (above) s/c 3, but southward (below) of s/c 1, 2 and 4. The peak electric currents along the central axis of the flux rope predicted by these single-s/c models were approx.15-19 nA/sq m. The 4-spacecraft Cluster magnetic field measurements provide a second means to determine the electric current density without any assumption regarding flux rope structure. The current profile determined using the curlometer technique was qualitatively similar to those determined by modeling the individual spacecraft magnetic field observations and yielded a peak current density of 17 nA/m2 near the central axis of the rope. However, the curlometer results also showed that the flux rope was not force-free with the component of the current density perpendicular to the magnetic field exceeding the parallel component over the forward half of the rope, perhaps due to the pressure gradients generated by the collision of the BBF with the inner magnetosphere. Hence, while the single-spacecraft models are very successful in fitting flux rope magnetic field and current variations, they do not provide a stringent test of the force-free condition.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017JPhD...50h5204K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017JPhD...50h5204K"><span>Shock wave interaction with a thermal layer produced by a <span class="hlt">plasma</span> <span class="hlt">sheet</span> actuator</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Koroteeva, E.; Znamenskaya, I.; Orlov, D.; Sysoev, N.</p> <p>2017-03-01</p> <p>This paper explores the phenomena associated with pulsed discharge energy deposition in the near-surface gas layer in front of a shock wave from the flow control perspective. The energy is deposited in 200 ns by a high-current distributed sliding discharge of a ‘<span class="hlt">plasma</span> sheet’ type. The discharge, covering an area of 100× 30 mm2, is mounted on the top or bottom wall of a shock tube channel. In order to analyse the time scales of the pulsed discharge effect on an unsteady supersonic flow, we consider the propagation of a planar shock wave along the discharge surface area 50–500 μs after the discharge pulse. The processes in the discharge chamber are visualized experimentally using the shadowgraph method and modelled numerically using 2D/3D CFD simulations. The interaction between the planar shock wave and the discharge-induced thermal layer results in the formation of a lambda-shock configuration and the generation of vorticity in the flow behind the shock front. We determine the amount and spatial distribution of the electric energy rapidly transforming into heat by comparing the calculated flow patterns and the experimental shadow images. It is shown that the uniformity of the discharge energy distribution strongly affects the resulting flow dynamics. Regions of turbulent mixing in the near-surface gas are detected when the discharge energy is deposited non-uniformly along the <span class="hlt">plasma</span> <span class="hlt">sheet</span>. They account for the increase in the cooling rate of the discharge-induced thermal layer and significantly influence its interaction with an incident shock wave.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016PhPl...23h3509G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016PhPl...23h3509G"><span>Modeling the effect of doping on the catalyst-assisted growth and field emission properties of <span class="hlt">plasma</span>-grown graphene <span class="hlt">sheet</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Gupta, Neha; Sharma, Suresh C.; Sharma, Rinku</p> <p>2016-08-01</p> <p>A theoretical model describing the effect of doping on the <span class="hlt">plasma</span>-assisted catalytic growth of graphene <span class="hlt">sheet</span> has been developed. The model accounts the charging rate of the graphene <span class="hlt">sheet</span>, kinetics of all the <span class="hlt">plasma</span> species, including the doping species, and the growth rate of graphene nuclei and graphene <span class="hlt">sheet</span> due to surface diffusion, and accretion of ions on the catalyst nanoparticle. Using the model, it is observed that nitrogen and boron doping can strongly influence the growth and field emission properties of the graphene <span class="hlt">sheet</span>. The results of the present investigation indicate that nitrogen doping results in reduced thickness and shortened height of the graphene <span class="hlt">sheet</span>; however, boron doping increases the thickness and height of the graphene <span class="hlt">sheet</span>. The time evolutions of the charge on the graphene <span class="hlt">sheet</span> and hydrocarbon number density for nitrogen and boron doped graphene <span class="hlt">sheet</span> have also been examined. The field emission properties of the graphene <span class="hlt">sheet</span> have been proposed on the basis of the results obtained. It is concluded that nitrogen doped graphene <span class="hlt">sheet</span> exhibits better field emission characteristics as compared to undoped and boron doped graphene <span class="hlt">sheet</span>. The results of the present investigation are consistent with the existing experimental observations.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/21124056','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/21124056"><span>Femtosecond laser-induced <span class="hlt">electronic</span> <span class="hlt">plasma</span> at metal surface</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Chen Zhaoyang; Mao, Samuel S.</p> <p>2008-08-04</p> <p>We develop a theoretical analysis to model <span class="hlt">plasma</span> initiation at the early stage of femtosecond laser irradiation of metal surfaces. The calculation reveals that there is a threshold intensity for the formation of a microscale <span class="hlt">electronic</span> <span class="hlt">plasma</span> at the laser-irradidated metal surface. As the full width at half maximum of a laser pulse increases from 15 to 200 fs, the <span class="hlt">plasma</span> formation threshold decreases by merely about 20%. The dependence of the threshold intensity on laser pulse width can be attributed to laser-induced surface <span class="hlt">electron</span> emission, in particular due to the effect of photoelectric effect.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/5370531','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/5370531"><span>The influence of <span class="hlt">plasma</span> motion on disruption generated runaway <span class="hlt">electrons</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Russo, A.J.</p> <p>1991-01-01</p> <p>One of the possible consequences of disruptions is the generation of runaway <span class="hlt">electrons</span> which can impact <span class="hlt">plasma</span> facing components and cause damage due to high local energy deposition. This problem becomes more serious as the machine size and <span class="hlt">plasma</span> current increases. Since large size and high currents are characteristics of proposed future machines, control of runaway generation is an important design consideration. A lumped circuit model for disruption runaway <span class="hlt">electron</span> generation indicates that control circuitry on strongly influence runaway behavior. A comparison of disruption data from several shots on JET and D3-D with model results, demonstrate the effects of <span class="hlt">plasma</span> motion on runaway number density and energy. 6 refs., 12 figs.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1998PhRvE..57.1029T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1998PhRvE..57.1029T"><span>Beam acceleration by <span class="hlt">plasma</span>-loaded free-<span class="hlt">electron</span> devices</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Tsui, K. H.; Serbeto, A.; D'olival, J. B.</p> <p>1998-01-01</p> <p>The use of a <span class="hlt">plasma</span>-filled wiggler free-<span class="hlt">electron</span> laser device operating near the <span class="hlt">plasma</span> cutoff to accelerate <span class="hlt">electron</span> beams is examined. Near the cutoff, the group velocity of the microwave field in the <span class="hlt">plasma</span> is much less than the beam velocity. This scheme, therefore, operates in the pulse mode to accelerate <span class="hlt">electron</span> beam bunches much shorter than the wiggler length. Between one bunch and the other, the wiggler is reloaded with microwave field. During the loading period, the laser-wiggler-<span class="hlt">plasma</span> (SWL) Raman interaction generates a Langmuir mode with the laser and the wiggler as the primary energy sources. When the wiggler <span class="hlt">plasma</span> is fully loaded with microwave field, a short <span class="hlt">electron</span> bunch is fired into the device. In this accelerating period, the Langmuir mode is coupled to the laser-wiggler-beam (SWB) free-<span class="hlt">electron</span>-laser interaction. The condition that the Langmuir phase velocity matches the free-<span class="hlt">electron</span>-laser resonant beam velocity assures the simultaneous interaction of the SWL and SWB parametric processes. Beam acceleration is accomplished fundamentally via the space charge field of the Langmuir mode and the <span class="hlt">electron</span> phase in the ponderomotive potential. Linear energy gain regime is accomplished when the phase velocity of the Langmuir mode is exactly equal to the speed of light.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/530004','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/530004"><span>Thermal conduction by <span class="hlt">electrons</span> in hot dense <span class="hlt">plasmas</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Khalfaoui, A.H.; Bennaceur, D.</p> <p>1997-03-01</p> <p>Based on a quantum collective approach, <span class="hlt">electron</span> conduction opacity is analyzed, taking into account several nonideality effects such as <span class="hlt">electron-electron</span> (e-e) collisions in addition to <span class="hlt">electron</span>-ion collisions, dynamic shielding, <span class="hlt">electron</span> partial degeneracy, and ion coupling. The collision process is based on <span class="hlt">electron</span> wave functions interacting with the continuum oscillations (<span class="hlt">plasma</span> waves). The e-e collisions, the main nonideal effect, contribute to the thermal conductivity calculation in the intermediate coupling regime. Hence, the extensively used Lorentz gas approximation cannot be justified for <span class="hlt">plasma</span> of astrophysical interest. The present results are compared to existing theories of <span class="hlt">electron</span> conduction in stellar matter. {copyright} {ital 1997} {ital The American Astronomical Society}</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2007AGUSMSM41A..06S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2007AGUSMSM41A..06S"><span>Field-Aligned Current at <span class="hlt">Plasma</span> <span class="hlt">Sheet</span> Boundary Layers During Storm Time: Cluster Observation</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Shi, J.; Cheng, Z.; Zhang, T.; Dunlop, M.; Liu, Z.</p> <p>2007-05-01</p> <p>The magnetic field data from the FGM instruments on board the four Cluster spacecrafts were used to study Field Aligned Current (FAC) at the <span class="hlt">Plasma</span> <span class="hlt">Sheet</span> Boundary Layers (PSBLs) with the so called "curlometer technique". We analyzed the date obtained in 2001 in the magnetotail and only two cases were found in the storm time. One (August 17, 2001) occurred from sudden commencement to main phase, and the other (October 1, 2001) lay in the main phase and recovery phase. The relationship between the FAC density and the AE index was studied and the results are shown as follows. (1) In the sudden commencement and the main phase the density of the FAC increases obviously, in the recovery phase the density of the FAC increases slightly. (2) From the sudden commencement to the initial stage of the main phase the FAC increases with decreasing AE index and decreases with increasing AE index. From the late stage of the main phase to initial stage of the recovery phase, the FAC increases with increasing AE index and decreases with decreasing AE index. In the late stage of the recovery phase the disturbance of the FAC is not so violent, so that the FAC varying with the AE index is not very obvious.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li class="active"><span>18</span></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_18 --> <div id="page_19" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li class="active"><span>19</span></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="361"> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/6966188','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/6966188"><span>Report of the working group on magnetotail/<span class="hlt">plasma</span> <span class="hlt">sheet</span> structure</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Birn, J. ); Fairfield, D. . Goddard Space Flight Center)</p> <p>1992-01-01</p> <p>The magnetotail and its imbedded <span class="hlt">plasma</span> <span class="hlt">sheet</span> represent the major region where excess energy is stored in the magnetosphere. It is consequently the principal site where energy release starts and magnetospheric activity is initiated. The qualitative understanding and quantitative description of its average and instantaneous structure and its dependence on solar wind and ionospheric boundary conditions are therefore at the core of magnetospheric physics and modeling. In this report we concentrate on the assessment of present knowledge and open questions concerning the average tail and its instantaneous structure during steady periods or for changes that are slow in comparison to the fast dynamic scale of magnetospheric substorms. Quantitatively, one might draw a destinction at about 1 minute, which is slightly larger than a typical magnetosonic (or Alfven) wave propagation time over a characteristic macroscopic scale of a few Earth radii. This restriction not only excludes the fast dynamic evolution after substorm (expansive phase) onset but also time-dependent phenomena such as waves, eigenmodes, etc. that are not necessarily related to substorm activity. We also exclude questions of stability. The major goal within this area consists of the construction and improvement of quantitative models, empirical and selfconsistent, at various levels of sophistication as required by particular applications. Such models not only represent the quantification of observations and physical understanding of the magnetospheric structure but also are needed as the basis for a variety of further investigations, such as test particle studies, stability analyses, and MHD simulations.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/10112259','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/10112259"><span>Report of the working group on magnetotail/<span class="hlt">plasma</span> <span class="hlt">sheet</span> structure</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Birn, J.; Fairfield, D.</p> <p>1992-12-01</p> <p>The magnetotail and its imbedded <span class="hlt">plasma</span> <span class="hlt">sheet</span> represent the major region where excess energy is stored in the magnetosphere. It is consequently the principal site where energy release starts and magnetospheric activity is initiated. The qualitative understanding and quantitative description of its average and instantaneous structure and its dependence on solar wind and ionospheric boundary conditions are therefore at the core of magnetospheric physics and modeling. In this report we concentrate on the assessment of present knowledge and open questions concerning the average tail and its instantaneous structure during steady periods or for changes that are slow in comparison to the fast dynamic scale of magnetospheric substorms. Quantitatively, one might draw a destinction at about 1 minute, which is slightly larger than a typical magnetosonic (or Alfven) wave propagation time over a characteristic macroscopic scale of a few Earth radii. This restriction not only excludes the fast dynamic evolution after substorm (expansive phase) onset but also time-dependent phenomena such as waves, eigenmodes, etc. that are not necessarily related to substorm activity. We also exclude questions of stability. The major goal within this area consists of the construction and improvement of quantitative models, empirical and selfconsistent, at various levels of sophistication as required by particular applications. Such models not only represent the quantification of observations and physical understanding of the magnetospheric structure but also are needed as the basis for a variety of further investigations, such as test particle studies, stability analyses, and MHD simulations.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=20120007917&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D70%26Ntt%3Do','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20120007917&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D70%26Ntt%3Do"><span>Energetic O+ and H+ Ions in the <span class="hlt">Plasma</span> <span class="hlt">Sheet</span>: Implications for the Transport of Ionospheric Ions</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Ohtani, S.; Nose, M.; Christon, S. P.; Lui, A. T.</p> <p>2011-01-01</p> <p>The present study statistically examines the characteristics of energetic ions in the <span class="hlt">plasma</span> <span class="hlt">sheet</span> using the Geotail/Energetic Particle and Ion Composition data. An emphasis is placed on the O+ ions, and the characteristics of the H+ ions are used as references. The following is a summary of the results. (1) The average O+ energy is lower during solar maximum and higher during solar minimum. A similar tendency is also found for the average H+ energy, but only for geomagnetically active times; (2) The O+ -to -H+ ratios of number and energy densities are several times higher during solar maximum than during solar minimum; (3) The average H+ and O+ energies and the O+ -to -H+ ratios of number and energy densities all increase with geomagnetic activity. The differences among different solar phases not only persist but also increase with increasing geomagnetic activity; (4) Whereas the average H+ energy increases toward Earth, the average O+ energy decreases toward Earth. The average energy increases toward dusk for both the H+ and O+ ions; (5) The O+ -to -H+ ratios of number and energy densities increase toward Earth during all solar phases, but most clearly during solar maximum. These results suggest that the solar illumination enhances the ionospheric outflow more effectively with increasing geomagnetic activity and that a significant portion of the O+ ions is transported directly from the ionosphere to the near ]Earth region rather than through the distant tail.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016ApPhL.109t1602P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016ApPhL.109t1602P"><span>Secondary <span class="hlt">electron</span> emission from <span class="hlt">plasma</span>-generated nanostructured tungsten fuzz</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Patino, M.; Raitses, Y.; Wirz, R.</p> <p>2016-11-01</p> <p>Recently, several researchers [e.g., Yang et al., Sci. Rep. 5, 10959 (2015)] have shown that tungsten fuzz can grow on a hot tungsten surface under bombardment by energetic helium ions in different <span class="hlt">plasma</span> discharges and applications, including magnetic fusion devices with <span class="hlt">plasma</span> facing tungsten components. This work reports the direct measurements of the total effective secondary <span class="hlt">electron</span> emission (SEE) from tungsten fuzz. Using dedicated material surface diagnostics and in-situ characterization, we find two important results: (1) SEE values for tungsten fuzz are 40%-63% lower than for smooth tungsten and (2) the SEE values for tungsten fuzz are independent of the angle of the incident <span class="hlt">electron</span>. The reduction in SEE from tungsten fuzz is most pronounced at high incident angles, which has important implications for many <span class="hlt">plasma</span> devices since in a negative-going sheath the potential structure leads to relatively high incident angles for the <span class="hlt">electrons</span> at the <span class="hlt">plasma</span> confining walls. Overall, low SEE will create a relatively higher sheath potential difference that reduces <span class="hlt">plasma</span> <span class="hlt">electron</span> energy loss to the confining wall. Thus, the presence or self-generation in a <span class="hlt">plasma</span> of a low SEE surface such as tungsten fuzz can be desirable for improved performance of many <span class="hlt">plasma</span> devices.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015APS..GECQR1002G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015APS..GECQR1002G"><span>Hydrated <span class="hlt">Electrons</span> at the <span class="hlt">Plasma</span>-Water Interface</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Graves, David; Gopalakrishnan, Ranga; Kawamura, Emi; Lieberman, Michael</p> <p>2015-09-01</p> <p>When atmospheric pressure <span class="hlt">plasma</span> interacts with liquid water surfaces, complex processes involving both charged and neutral species generally occur but the details of the processes are not well understood. One <span class="hlt">plasma</span>-generated specie of considerable interest that can enter an adjacent liquid water phase is the <span class="hlt">electron</span>. Hydrated <span class="hlt">electrons</span> are well known to be important in radiation chemistry as initiating precursors for a variety of other reactive compounds. Recent experimental evidence for hydrated <span class="hlt">electrons</span> near the atmospheric pressure <span class="hlt">plasma</span>-water interface was reported by Rumbach et al.. We present results from a model of a dc argon <span class="hlt">plasma</span> coupled to an anodic adjacent water layer that aims to simulate this experiment. The coupled <span class="hlt">plasma</span>-electrolyte model illustrates the nature of the <span class="hlt">plasma</span>-water interface and reveals important information regarding the self-consistent electric fields on each side of the interface as well as time- and space-resolved rates of reaction of key reactive species. We suggest that the reducing chemistry that results from <span class="hlt">electron</span> hydration may be useful therapeutically in countering local excess oxidative stress. Supported by the Department of Energy, Office of Fusion Science <span class="hlt">Plasma</span> Science Center</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/1335459','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/1335459"><span>Secondary <span class="hlt">electron</span> emission from <span class="hlt">plasma</span>-generated nanostructured tungsten fuzz</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Patino, M.; Raitses, Y.; Wirz, R.</p> <p>2016-11-14</p> <p>Recently, several researchers (e.g., Q. Yang, Y.-W. You, L. Liu, H. Fan, W. Ni, D. Liu, C. S. Liu, G. Benstetter, and Y. Wang, Scientific Reports 5, 10959 (2015)) have shown that tungsten fuzz can grow on a hot tungsten surface under bombardment by energetic helium ions in different <span class="hlt">plasma</span> discharges and applications, including magnetic fusion devices with <span class="hlt">plasma</span> facing tungsten components. This work reports direct measurements of the total effective secondary <span class="hlt">electron</span> emission (SEE) from tungsten fuzz. Using dedicated material surface diagnostics and in-situ characterization, we find two important results: (1) SEE values for tungsten fuzz are 40-63% lower than for smooth tungsten and (2) the SEE values for tungsten fuzz are independent of the angle of the incident <span class="hlt">electron</span>. The reduction in SEE from tungsten fuzz is most pronounced at high incident angles, which has important implications for many <span class="hlt">plasma</span> devices since in a negative-going sheath the potential structure leads to relatively high incident angles for the <span class="hlt">electrons</span> at the <span class="hlt">plasma</span> confining walls. Overall, low SEE will create a relatively higher sheath potential difference that reduces <span class="hlt">plasma</span> <span class="hlt">electron</span> energy loss to the confining wall. Thus the presence or self-generation in a <span class="hlt">plasma</span> of a low SEE surface such as tungsten fuzz can be desirable for improved performance of many <span class="hlt">plasma</span> devices.:7px</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/pages/biblio/1335459-secondary-electron-emission-from-plasma-generated-nanostructured-tungsten-fuzz','SCIGOV-DOEP'); return false;" href="https://www.osti.gov/pages/biblio/1335459-secondary-electron-emission-from-plasma-generated-nanostructured-tungsten-fuzz"><span>Secondary <span class="hlt">electron</span> emission from <span class="hlt">plasma</span>-generated nanostructured tungsten fuzz</span></a></p> <p><a target="_blank" href="http://www.osti.gov/pages">DOE PAGES</a></p> <p>Patino, M.; Raitses, Y.; Wirz, R.</p> <p>2016-11-14</p> <p>Recently, several researchers (e.g., Q. Yang, Y.-W. You, L. Liu, H. Fan, W. Ni, D. Liu, C. S. Liu, G. Benstetter, and Y. Wang, Scientific Reports 5, 10959 (2015)) have shown that tungsten fuzz can grow on a hot tungsten surface under bombardment by energetic helium ions in different <span class="hlt">plasma</span> discharges and applications, including magnetic fusion devices with <span class="hlt">plasma</span> facing tungsten components. This work reports direct measurements of the total effective secondary <span class="hlt">electron</span> emission (SEE) from tungsten fuzz. Using dedicated material surface diagnostics and in-situ characterization, we find two important results: (1) SEE values for tungsten fuzz are 40-63% lowermore » than for smooth tungsten and (2) the SEE values for tungsten fuzz are independent of the angle of the incident <span class="hlt">electron</span>. The reduction in SEE from tungsten fuzz is most pronounced at high incident angles, which has important implications for many <span class="hlt">plasma</span> devices since in a negative-going sheath the potential structure leads to relatively high incident angles for the <span class="hlt">electrons</span> at the <span class="hlt">plasma</span> confining walls. Overall, low SEE will create a relatively higher sheath potential difference that reduces <span class="hlt">plasma</span> <span class="hlt">electron</span> energy loss to the confining wall. Thus the presence or self-generation in a <span class="hlt">plasma</span> of a low SEE surface such as tungsten fuzz can be desirable for improved performance of many <span class="hlt">plasma</span> devices.:7px« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19760046893&hterms=plasma+explained&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3Dplasma%2Bexplained','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19760046893&hterms=plasma+explained&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3Dplasma%2Bexplained"><span><span class="hlt">Electron</span> <span class="hlt">plasma</span> oscillations associated with type III radio emissions and solar <span class="hlt">electrons</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Gurnett, D. A.; Frank, L. A.</p> <p>1975-01-01</p> <p>Results of an extensive search for <span class="hlt">electron</span> <span class="hlt">plasma</span> oscillations associated with type III radio noise bursts are presented which were obtained by analyzing 87 type III bursts detected in <span class="hlt">plasma</span>-wave and charged-particle measurements carried out by IMP 6, 7, and 8. Only one case is found for which <span class="hlt">plasma</span> oscillations were associated with <span class="hlt">electrons</span> of solar origin; at least eight events are identified in which no <span class="hlt">plasma</span> oscillations were detected even though <span class="hlt">electrons</span> from solar flares were clearly evident. The type III emissions are compared with similar radiation coming from upstream of earth's bow shock at the harmonic of the local <span class="hlt">electron</span> <span class="hlt">plasma</span> frequency, and quantitative calculations of the rate of conversion from <span class="hlt">plasma</span> oscillatory energy to electromagnetic radiation are performed. The results show that <span class="hlt">electron</span> <span class="hlt">plasma</span> oscillations are seldom observed in association with solar <span class="hlt">electron</span> events and type III radio bursts at 1.0 AU and that neither the type III emissions nor the radiation from upstream of the bow shock can be adequately explained by a current model for the coupling of <span class="hlt">electron</span> <span class="hlt">plasma</span> oscillations to electromagnetic radiation. Several possible explanations are considered for this discrepancy between theory and observations.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010Nanot..21i5601K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010Nanot..21i5601K"><span>Fabrication of graphene flakes composed of multi-layer graphene <span class="hlt">sheets</span> using a thermal <span class="hlt">plasma</span> jet system</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kim, Juhan; Heo, Soo Bong; Hoi Gu, Geun; Suh, Jung Sang</p> <p>2010-03-01</p> <p>We have developed a method to fabricate graphene flakes composed of high quality multi-layer graphene <span class="hlt">sheets</span> using a thermal <span class="hlt">plasma</span> jet system. A carbon atomic beam was generated by injecting ethanol into Ar <span class="hlt">plasma</span> continuously; the beam then flowed through a carbon tube attached to the anode. Graphene was made by epitaxial growth where a carbon atomic beam, having the proper energy, collided with a graphite plate. The graphene fabricated was very pure and showed a relatively good crystalline structure. We have demonstrated that the number of layers of graphene <span class="hlt">sheets</span> could be controlled by controlling the rate of ethanol injection. Our process is a continuous process with a relatively high yield (~8%).</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016APS..DPPTO8015B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016APS..DPPTO8015B"><span>Shock Formation in <span class="hlt">Electron</span>-Ion <span class="hlt">Plasmas</span>: Mechanism and Timing</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Bret, Antoine; Stockem Novo, Anne; Ricardo, Fonseca; Luis, Silva</p> <p>2016-10-01</p> <p>We analyze the formation of a collisionless shock in <span class="hlt">electron</span>-ion <span class="hlt">plasmas</span> in theory and simulations. In initially un-magnetized relativistic <span class="hlt">plasmas</span>, such shocks are triggered by the Weibel instability. While in pair <span class="hlt">plasmas</span> the shock starts forming right after the instability saturates, it is not so in <span class="hlt">electron</span>-ion <span class="hlt">plasmas</span> because the Weibel filaments at saturation are too small. An additional merging phase is therefore necessary for them to efficiently stop the flow. We derive a theoretical model for the shock formation time, taking into account filament merging in the nonlinear phase of the Weibel instability. This process is much slower than in <span class="hlt">electron</span>-positron pair shocks, and so the shock formation is longer by a factor proportional to √{mi /me } ln(mi /me).</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016APS..GECTR3003T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016APS..GECTR3003T"><span><span class="hlt">Plasma</span> chemistry in <span class="hlt">electron</span>-beam sustained discharges</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Turner, Miles</p> <p>2016-09-01</p> <p>There are many emerging applications that exploit the exotic chemical characteristics of <span class="hlt">plasmas</span>. Some of these applications, if deployed on an industrial scale, involve processing much larger volumes of gas than seems reasonable using any atmospheric pressure <span class="hlt">plasma</span> source in wide use today. We note that an <span class="hlt">electron</span>-beam sustained discharge permits the creation of a atmospheric pressure <span class="hlt">plasma</span> with reasonable uniformity, large volme, and widely controllable <span class="hlt">electron</span> temperature. Robust and durable <span class="hlt">electron</span> beam sources now exist that would facilitate such applications. In this paper we discuss the general advantages of this approach, and we present a modelling study concerned with the production of NO in mixtures of N2 and O2, looking towards <span class="hlt">plasma</span> aided manufacturing of fertilizers.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/22408263','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/22408263"><span>Effect of secondary <span class="hlt">electron</span> emission on the <span class="hlt">plasma</span> sheath</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Langendorf, S. Walker, M.</p> <p>2015-03-15</p> <p>In this experiment, <span class="hlt">plasma</span> sheath potential profiles are measured over boron nitride walls in argon <span class="hlt">plasma</span> and the effect of secondary <span class="hlt">electron</span> emission is observed. Results are compared to a kinetic model. <span class="hlt">Plasmas</span> are generated with a number density of 3 × 10{sup 12} m{sup −3} at a pressure of 10{sup −4} Torr-Ar, with a 1%–16% fraction of energetic primary <span class="hlt">electrons</span>. The sheath potential profile at the surface of each sample is measured with emissive probes. The <span class="hlt">electron</span> number densities and temperatures are measured in the bulk <span class="hlt">plasma</span> with a planar Langmuir probe. The <span class="hlt">plasma</span> is non-Maxwellian, with isotropic and directed energetic <span class="hlt">electron</span> populations from 50 to 200 eV and hot and cold Maxwellian populations from 3.6 to 6.4 eV and 0.3 to 1.3 eV, respectively. <span class="hlt">Plasma</span> Debye lengths range from 4 to 7 mm and the ion-neutral mean free path is 0.8 m. Sheath thicknesses range from 20 to 50 mm, with the smaller thickness occurring near the critical secondary <span class="hlt">electron</span> emission yield of the wall material. Measured floating potentials are within 16% of model predictions. Measured sheath potential profiles agree with model predictions within 5 V (∼1 T{sub e}), and in four out of six cases deviate less than the measurement uncertainty of 1 V.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/22399196','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/22399196"><span>Numerical model of the <span class="hlt">plasma</span> formation at <span class="hlt">electron</span> beam welding</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Trushnikov, D. N.; Mladenov, G. M.</p> <p>2015-01-07</p> <p>The model of <span class="hlt">plasma</span> formation in the keyhole in liquid metal as well as above the <span class="hlt">electron</span> beam welding zone is described. The model is based on solution of two equations for the density of <span class="hlt">electrons</span> and the mean <span class="hlt">electron</span> energy. The mass transfer of heavy <span class="hlt">plasma</span> particles (neutral atoms, excited atoms, and ions) is taken into account in the analysis by the diffusion equation for a multicomponent mixture. The electrostatic field is calculated using the Poisson equation. Thermionic <span class="hlt">electron</span> emission is calculated for the keyhole wall. The ionization intensity of the vapors due to beam <span class="hlt">electrons</span> and high-energy secondary and backscattered <span class="hlt">electrons</span> is calibrated using the <span class="hlt">plasma</span> parameters when there is no polarized collector electrode above the welding zone. The calculated data are in good agreement with experimental data. Results for the <span class="hlt">plasma</span> parameters for excitation of a non-independent discharge are given. It is shown that there is a need to take into account the effect of a strong electric field near the keyhole walls on <span class="hlt">electron</span> emission (the Schottky effect) in the calculation of the current for a non-independent discharge (hot cathode gas discharge). The calculated <span class="hlt">electron</span> drift velocities are much bigger than the velocity at which current instabilities arise. This confirms the hypothesis for ion-acoustic instabilities, observed experimentally in previous research.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017PSST...26b5009Y','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017PSST...26b5009Y"><span><span class="hlt">Electron</span> presheaths: the outsized influence of positive boundaries on <span class="hlt">plasmas</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Yee, B. T.; Scheiner, B.; Baalrud, S. D.; Barnat, E. V.; Hopkins, M. M.</p> <p>2017-02-01</p> <p><span class="hlt">Electron</span> sheaths form near the surface of objects biased more positive than the <span class="hlt">plasma</span> potential, such as a Langmuir probe collecting <span class="hlt">electron</span> saturation current. Generally, the formation of <span class="hlt">electron</span> sheaths requires that the <span class="hlt">electron</span>-collecting area be sufficiently smaller (\\sqrt{2.3{m}e/M} times) than the ion-collecting area. They are commonly thought to be local phenomena that collect the random thermal <span class="hlt">electron</span> current, but do not otherwise perturb a <span class="hlt">plasma</span>. Here, using experiments on an electrode embedded in a wall in a helium discharge, particle-in-cell simulations, and theory it is shown that under low temperature <span class="hlt">plasma</span> conditions ({T}e\\gg {T}i) <span class="hlt">electron</span> sheaths are far from local. Instead, a long presheath region (27 mm, approximately an electron’s mean free path) extends into the <span class="hlt">plasma</span> where <span class="hlt">electrons</span> are accelerated via a pressure gradient to a flow speed exceeding the <span class="hlt">electron</span> thermal speed at the sheath edge. This fast flow is found to excite instabilities, causing strong fluctuations near the sheath edge.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/489098','DOE-PATENT-XML'); return false;" href="http://www.osti.gov/scitech/biblio/489098"><span>Method for generating a <span class="hlt">plasma</span> wave to accelerate <span class="hlt">electrons</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Umstadter, D.; Esarey, E.; Kim, J.K.</p> <p>1997-06-10</p> <p>The invention provides a method and apparatus for generating large amplitude nonlinear <span class="hlt">plasma</span> waves, driven by an optimized train of independently adjustable, intense laser pulses. In the method, optimal pulse widths, interpulse spacing, and intensity profiles of each pulse are determined for each pulse in a series of pulses. A resonant region of the <span class="hlt">plasma</span> wave phase space is found where the <span class="hlt">plasma</span> wave is driven most efficiently by the laser pulses. The accelerator system of the invention comprises several parts: the laser system, with its pulse-shaping subsystem; the <span class="hlt">electron</span> gun system, also called beam source, which preferably comprises photo cathode <span class="hlt">electron</span> source and RF-LINAC accelerator; <span class="hlt">electron</span> photo-cathode triggering system; the <span class="hlt">electron</span> diagnostics; and the feedback system between the <span class="hlt">electron</span> diagnostics and the laser system. The system also includes <span class="hlt">plasma</span> source including vacuum chamber, magnetic lens, and magnetic field means. The laser system produces a train of pulses that has been optimized to maximize the axial electric field amplitude of the <span class="hlt">plasma</span> wave, and thus the <span class="hlt">electron</span> acceleration, using the method of the invention. 21 figs.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016APS..DPPC10150M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016APS..DPPC10150M"><span><span class="hlt">Electron</span> Heating in Microwave-Assisted Helicon <span class="hlt">Plasmas</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>McKee, John; Siddiqui, Umair; Jemiolo, Andrew; McIlvain, Julianne; Scime, Earl</p> <p>2016-10-01</p> <p>The use of two (or more) rf sources at different frequencies is a common technique in the <span class="hlt">plasma</span> processing industry to control ion energy characteristics separately from <span class="hlt">plasma</span> generation. A similar approach is presented here with the focus on modifying the <span class="hlt">electron</span> population in argon and helium <span class="hlt">plasmas</span>. The <span class="hlt">plasma</span> is generated by a helicon source at a frequency f 0 = 13.56 MHz. Mcrowaves of frequency f 1 = 2.45 GHz are then injected into the helicon source chamber perpendicular to the background magnetic field. The microwaves damp on the <span class="hlt">electrons</span> via X-mode <span class="hlt">Electron</span> Cyclotron Heating (ECH) at the upper hybrid resonance, providing additional energy input into the <span class="hlt">electrons</span>. The effects of this secondary-source heating on <span class="hlt">electron</span> density, temperature, and energy distribution function are examined and compared to helicon-only single source <span class="hlt">plasmas</span> as well as numeric models suggesting that the heating is not evenly distributed but spatially localized. Optical Emission Spectroscopy (OES) is used to examine the impact of the energetic tail of the <span class="hlt">electron</span> distribution on ion and neutral species via collisional excitation. Large enhancements of neutral spectral lines are observed with little to no enhancement of ion lines.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/870998','DOE-PATENT-XML'); return false;" href="http://www.osti.gov/scitech/servlets/purl/870998"><span>Method for generating a <span class="hlt">plasma</span> wave to accelerate <span class="hlt">electrons</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Umstadter, Donald; Esarey, Eric; Kim, Joon K.</p> <p>1997-01-01</p> <p>The invention provides a method and apparatus for generating large amplitude nonlinear <span class="hlt">plasma</span> waves, driven by an optimized train of independently adjustable, intense laser pulses. In the method, optimal pulse widths, interpulse spacing, and intensity profiles of each pulse are determined for each pulse in a series of pulses. A resonant region of the <span class="hlt">plasma</span> wave phase space is found where the <span class="hlt">plasma</span> wave is driven most efficiently by the laser pulses. The accelerator system of the invention comprises several parts: the laser system, with its pulse-shaping subsystem; the <span class="hlt">electron</span> gun system, also called beam source, which preferably comprises photo cathode <span class="hlt">electron</span> source and RF-LINAC accelerator; <span class="hlt">electron</span> photo-cathode triggering system; the <span class="hlt">electron</span> diagnostics; and the feedback system between the <span class="hlt">electron</span> diagnostics and the laser system. The system also includes <span class="hlt">plasma</span> source including vacuum chamber, magnetic lens, and magnetic field means. The laser system produces a train of pulses that has been optimized to maximize the axial electric field amplitude of the <span class="hlt">plasma</span> wave, and thus the <span class="hlt">electron</span> acceleration, using the method of the invention.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012RScI...83i3504S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012RScI...83i3504S"><span>Revisiting <span class="hlt">plasma</span> hysteresis with an <span class="hlt">electronically</span> compensated Langmuir probe</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Srivastava, P. K.; Singh, S. K.; Awasthi, L. M.; Mattoo, S. K.</p> <p>2012-09-01</p> <p>The measurement of <span class="hlt">electron</span> temperature in <span class="hlt">plasma</span> by Langmuir probes, using ramped bias voltage, is seriously affected by the capacitive current of capacitance of the cable between the probe tip and data acquisition system. In earlier works a dummy cable was used to balance the capacitive currents. Under these conditions, the measured capacitive current was kept less than a few mA. Such probes are suitable for measurements in <span class="hlt">plasma</span> where measured ion saturation current is of the order of hundreds of mA. This paper reports that controlled balancing of capacitive current can be minimized to less than 20 μA, allowing <span class="hlt">plasma</span> measurements to be done with ion saturation current of the order of hundreds of μA. The <span class="hlt">electron</span> temperature measurement made by using probe compensation technique becomes independent of sweep frequency. A correction of ≤45% is observed in measured <span class="hlt">electron</span> temperature values when compared with uncompensated probe. This also enhances accuracy in the measurement of fluctuation in <span class="hlt">electron</span> temperature as δTpk-pk changes by ˜30%. The developed technique with swept rate ≤100 kHz is found accurate enough to measure both the <span class="hlt">electron</span> temperature and its fluctuating counterpart. This shows its usefulness in measuring accurately the temperature fluctuations because of <span class="hlt">electron</span> temperature gradient in large volume <span class="hlt">plasma</span> device <span class="hlt">plasma</span> with frequency ordering ≤50 kHz.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/23020373','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/23020373"><span>Revisiting <span class="hlt">plasma</span> hysteresis with an <span class="hlt">electronically</span> compensated Langmuir probe.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Srivastava, P K; Singh, S K; Awasthi, L M; Mattoo, S K</p> <p>2012-09-01</p> <p>The measurement of <span class="hlt">electron</span> temperature in <span class="hlt">plasma</span> by Langmuir probes, using ramped bias voltage, is seriously affected by the capacitive current of capacitance of the cable between the probe tip and data acquisition system. In earlier works a dummy cable was used to balance the capacitive currents. Under these conditions, the measured capacitive current was kept less than a few mA. Such probes are suitable for measurements in <span class="hlt">plasma</span> where measured ion saturation current is of the order of hundreds of mA. This paper reports that controlled balancing of capacitive current can be minimized to less than 20 μA, allowing <span class="hlt">plasma</span> measurements to be done with ion saturation current of the order of hundreds of μA. The <span class="hlt">electron</span> temperature measurement made by using probe compensation technique becomes independent of sweep frequency. A correction of ≤45% is observed in measured <span class="hlt">electron</span> temperature values when compared with uncompensated probe. This also enhances accuracy in the measurement of fluctuation in <span class="hlt">electron</span> temperature as δT(pk-pk) changes by ~30%. The developed technique with swept rate ≤100 kHz is found accurate enough to measure both the <span class="hlt">electron</span> temperature and its fluctuating counterpart. This shows its usefulness in measuring accurately the temperature fluctuations because of <span class="hlt">electron</span> temperature gradient in large volume <span class="hlt">plasma</span> device <span class="hlt">plasma</span> with frequency ordering ≤50 kHz.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/6525482','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/6525482"><span>A reflex <span class="hlt">electron</span> beam discharge as a <span class="hlt">plasma</span> source for <span class="hlt">electron</span> beam generation</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Murray, C.S.; Rocca, J.J.; Szapiro, B. )</p> <p>1988-10-01</p> <p>A reflex <span class="hlt">electron</span> beam glow discharge has been used as a <span class="hlt">plasma</span> source for the generation of broad-area <span class="hlt">electron</span> beams. An <span class="hlt">electron</span> current of 120 A (12 A/cm/sup 2/) was extracted from the <span class="hlt">plasma</span> in 10 ..mu..s pulses and accelerated to energies greater than 1 keV in the gap between two grids. The scaling of the scheme for the generation of multikiloamp high-energy beams is discussed.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li class="active"><span>19</span></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_19 --> <div id="page_20" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li class="active"><span>20</span></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="381"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016CP....472...44L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016CP....472...44L"><span><span class="hlt">Electron</span>-vibration relaxation in oxygen <span class="hlt">plasmas</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Laporta, V.; Heritier, K. L.; Panesi, M.</p> <p>2016-06-01</p> <p>An ideal chemical reactor model is used to study the vibrational relaxation of oxygen molecules in their ground <span class="hlt">electronic</span> state, X3Σg-, in presence of free <span class="hlt">electrons</span>. The model accounts for vibrational non-equilibrium between the translational energy mode of the gas and the vibrational energy mode of individual molecules. The vibrational levels of the molecules are treated as separate species, allowing for non-Boltzmann distributions of their population. The <span class="hlt">electron</span> and vibrational temperatures are varied in the range [0-20,000] K. Numerical results show a fast energy transfer between oxygen molecules and free <span class="hlt">electron</span>, which causes strong deviation of the vibrational distribution function from Boltzmann distribution, both in heating and cooling conditions. Comparison with Landau-Teller model is considered showing a good agreement for <span class="hlt">electron</span> temperature range [2000-12,000] K. Finally analytical fit of the vibrational relaxation time is given.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19820058707&hterms=Harp&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D70%26Ntt%3DHarp','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19820058707&hterms=Harp&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D70%26Ntt%3DHarp"><span>Suprathermal <span class="hlt">electrons</span> produced by beam-<span class="hlt">plasma</span>-discharge</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Sharp, W. E.</p> <p>1982-01-01</p> <p>Experiments conducted with a low energy <span class="hlt">plasma</span> lens, HARP, in the <span class="hlt">electron</span> beam of the large vacuum chamber at Johnson Space Center indicate that an enhanced population of 50 to 300 volt <span class="hlt">electrons</span> appear when the beam goes into the Beam-<span class="hlt">Plasma</span> Discharge (BPD) mode. Below the BPD instability the <span class="hlt">electron</span> distribution appears to be characterized as non-energized single particle scattering and energy loss. At 100 cm from the beam core in the BPD mode the fluxes parallel to the beam are reduced by a factor of 20 with respect to the fluxes at 25 cm. Some evidence for isotropy near the beam core is presented.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2002EGSGA..27.1483C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2002EGSGA..27.1483C"><span>Extensions of 1d Bgk <span class="hlt">Electron</span> Solitary Wave Solutions To 3d Magnetized and Unmagnetized <span class="hlt">Plasmas</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Chen, Li-Jen; Parks, George K.</p> <p></p> <p>This paper will compare the key results for BGK <span class="hlt">electron</span> solitary waves in 3D mag- netized and unmagnetized <span class="hlt">plasmas</span>. For 3D magnetized <span class="hlt">plasmas</span> with highly magnetic field-aligned <span class="hlt">electrons</span>, our results predict that the parallel widths of the solitary waves can be smaller than one Debye length, the solitary waves can be large scale features of the magnetosphere, and the parallel width-amplitude relation has a dependence on the perpendicular size. We can thus obtain an estimate on the typical perpendicular size of the observed solitary waves assuming a series of consecutive solitary waves are in the same flux tude with a particular perpendicular span. In 3D unmagnetized <span class="hlt">plasma</span> systems such as the neutral <span class="hlt">sheet</span> and magnetic reconnection sites, our theory indi- cates that although mathematical solutions can be constructed as the time-stationary solutions for the nonlinear Vlasov-Poisson equations, there does not exist a param- eter range for the solutions to be physical. We conclude that single-humped solitary potential pulses cannot be self-consistently supported by charged particles in 3D un- magnetized <span class="hlt">plasmas</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017ApJ...836...55R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017ApJ...836...55R"><span>An Exploration of Heating Mechanisms in a Supra-arcade <span class="hlt">Plasma</span> <span class="hlt">Sheet</span> Formed after a Coronal Mass Ejection</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Reeves, Katharine K.; Freed, Michael S.; McKenzie, David E.; Savage, Sabrina L.</p> <p>2017-02-01</p> <p>We perform a detailed analysis of the thermal structure of the region above the post-eruption arcade for a flare that occurred on 2011 October 22. During this event, a <span class="hlt">sheet</span> of hot <span class="hlt">plasma</span> is visible above the flare loops in the 131 Å bandpass of the Atmospheric Imaging Assembly (AIA) on the Solar Dynamics Observatory. Supra-arcade downflows (SADs) are observed traveling sunward through the post-eruption <span class="hlt">plasma</span> <span class="hlt">sheet</span>. We calculate differential emission measures using the AIA data and derive an emission measure weighted average temperature in the supra-arcade region. In areas where many SADs occur, the temperature of the supra-arcade <span class="hlt">plasma</span> tends to increase, while in areas where no SADs are observed, the temperature tends to decrease. We calculate the plane-of-sky velocities in the supra-arcade <span class="hlt">plasma</span> and use them to determine the potential heating due to adiabatic compression and viscous heating. Of the 13 SADs studied, 10 have noticeable signatures in both the adiabatic and the viscous terms. The adiabatic heating due to compression of <span class="hlt">plasma</span> in front of the SADs is on the order of 0.1–0.2 MK/s, which is similar in magnitude to the estimated conductive cooling rate. This result supports the notion that SADs contribute locally to the heating of <span class="hlt">plasma</span> in the supra-arcade region. We also find that in the region without SADs, the <span class="hlt">plasma</span> cools at a rate that is slower than the estimated conductive cooling, indicating that additional heating mechanisms may act globally to keep the <span class="hlt">plasma</span> temperature high.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/22420281','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/22420281"><span>Non-thermal <span class="hlt">plasma</span> mills bacteria: Scanning <span class="hlt">electron</span> microscopy observations</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Lunov, O. Churpita, O.; Zablotskii, V.; Jäger, A.; Dejneka, A.; Deyneka, I. G.; Meshkovskii, I. K.; Syková, E.; Kubinová, Š.</p> <p>2015-02-02</p> <p>Non-thermal <span class="hlt">plasmas</span> hold great promise for a variety of biomedical applications. To ensure safe clinical application of <span class="hlt">plasma</span>, a rigorous analysis of <span class="hlt">plasma</span>-induced effects on cell functions is required. Yet mechanisms of bacteria deactivation by non-thermal <span class="hlt">plasma</span> remain largely unknown. We therefore analyzed the influence of low-temperature atmospheric <span class="hlt">plasma</span> on Gram-positive and Gram-negative bacteria. Using scanning <span class="hlt">electron</span> microscopy, we demonstrate that both Gram-positive and Gram-negative bacteria strains in a minute were completely destroyed by helium <span class="hlt">plasma</span>. In contrast, mesenchymal stem cells (MSCs) were not affected by the same treatment. Furthermore, histopathological analysis of hematoxylin and eosin–stained rat skin sections from plasma–treated animals did not reveal any abnormalities in comparison to control ones. We discuss possible physical mechanisms leading to the shred of bacteria under non-thermal <span class="hlt">plasma</span> irradiation. Our findings disclose how helium <span class="hlt">plasma</span> destroys bacteria and demonstrates the safe use of <span class="hlt">plasma</span> treatment for MSCs and skin cells, highlighting the favorability of <span class="hlt">plasma</span> applications for chronic wound therapy.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/15698185','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/15698185"><span>Fluid echoes in a pure <span class="hlt">electron</span> <span class="hlt">plasma</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Yu, J H; O'Neil, T M; Driscoll, C F</p> <p>2005-01-21</p> <p>Experimental observations of diocotron wave echoes on a magnetized <span class="hlt">electron</span> column are reported, representing Kelvin wave echoes on a rotating near-ideal fluid. The echoes occur by reversal of an inviscid wave damping process, and the phase-space mixing and unmixing are directly imaged. The basic echo characteristics agree with a simple nonlinear ballistic theory. At late times, the echo is degraded, and the maximal observed echo times agree with a theory of <span class="hlt">electron-electron</span> collisions acting on separately evolving velocity classes.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/22488668','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/22488668"><span>Kinetic Alfven wave in the presence of kappa distribution function in <span class="hlt">plasma</span> <span class="hlt">sheet</span> boundary layer</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Shrivastava, G. Ahirwar, G.; Shrivastava, J.</p> <p>2015-07-31</p> <p>The particle aspect approach is adopted to investigate the trajectories of charged particles in the electromagnetic field of kinetic Alfven wave. Expressions are found for the dispersion relation, damping/growth rate and associated currents in the presence of kappa distribution function. Kinetic effect of <span class="hlt">electrons</span> and ions are included to study kinetic Alfven wave because both are important in the transition region. It is found that the ratio β of <span class="hlt">electron</span> thermal energy density to magnetic field energy density and the ratio of ion to <span class="hlt">electron</span> thermal temperature (T{sub i}/T{sub e}), and kappa distribution function affect the dispersion relation, damping/growth rate and associated currents in both cases(warm and cold <span class="hlt">electron</span> limit).The treatment of kinetic Alfven wave instability is based on assumption that the <span class="hlt">plasma</span> consist of resonant and non resonant particles. The resonant particles participate in an energy exchange process, whereas the non resonant particles support the oscillatory motion of the wave.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/6734987','DOE-PATENT-XML'); return false;" href="http://www.osti.gov/scitech/biblio/6734987"><span>dc-<span class="hlt">plasma</span>-sprayed <span class="hlt">electronic</span>-tube device</span></a></p> <p><a target="_blank" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Meek, T.T.</p> <p>1982-01-29</p> <p>An <span class="hlt">electronic</span> tube and associated circuitry which is produced by dc <span class="hlt">plasma</span> arc spraying techniques is described. The process is carried out in a single step automated process whereby both active and passive devices are produced at very low cost. The circuitry is extremely reliable and is capable of functioning in both high radiation and high temperature environments. The size of the <span class="hlt">electronic</span> tubes produced are more than an order of magnitude smaller than conventional <span class="hlt">electronic</span> tubes.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/17503919','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/17503919"><span>Diagnosing pure-<span class="hlt">electron</span> <span class="hlt">plasmas</span> with internal particle flux probes.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Kremer, J P; Pedersen, T Sunn; Marksteiner, Q; Lefrancois, R G; Hahn, M</p> <p>2007-01-01</p> <p>Techniques for measuring local <span class="hlt">plasma</span> potential, density, and temperature of pure-<span class="hlt">electron</span> <span class="hlt">plasmas</span> using emissive and Langmuir probes are described. The <span class="hlt">plasma</span> potential is measured as the least negative potential at which a hot tungsten filament emits <span class="hlt">electrons</span>. Temperature is measured, as is commonly done in quasineutral <span class="hlt">plasmas</span>, through the interpretation of a Langmuir probe current-voltage characteristic. Due to the lack of ion-saturation current, the density must also be measured through the interpretation of this characteristic thereby greatly complicating the measurement. Measurements are further complicated by low densities, low cross field transport rates, and large flows typical of pure-<span class="hlt">electron</span> <span class="hlt">plasmas</span>. This article describes the use of these techniques on pure-<span class="hlt">electron</span> <span class="hlt">plasmas</span> in the Columbia Non-neutral Torus (CNT) stellarator. Measured values for present baseline experimental parameters in CNT are phi(p)=-200+/-2 V, T(e)=4+/-1 eV, and n(e) on the order of 10(12) m(-3) in the interior.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016APS..GECHT6023D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016APS..GECHT6023D"><span>Probe measurements of <span class="hlt">electron</span> energy spectrum in Helium/air micro-<span class="hlt">plasma</span> at atmospheric pressure</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Demidov, V. I.; Adams, S. F.; Miles, J. A.; Koepke, M. E.; Kurlyandskaya, I. P.; Hensley, A. L.; Tolson, B. A.</p> <p>2016-09-01</p> <p>It is experimentally demonstrated that a wall probe may be a useful instrument for interpretation of <span class="hlt">electron</span> energy spectrum in a micro-<span class="hlt">plasma</span> with a nonlocal <span class="hlt">electron</span> distribution function at atmospheric pressure. Two micro-<span class="hlt">plasma</span> devices were fabricated with three layers of molybdenum metal foils with thickness of 0.1 mm separated by two <span class="hlt">sheets</span> of mica insulation with thickness of 0.11 mm. In one device a hole with the diameter of 0.2 mm formed a cylindrical discharge cavity that passed through the entire five layers. In the second device the hole has the diameter of 0.065 mm. In both devices the inner molybdenum layer formed a wall probe, while the outer layers of molybdenum served as the hollow cathode and anode. The discharge was open into air with flow of helium gas. It is found that the wall probe I-V trace is sensitive to the presence of helium metastable atoms. The first derivative of the probe current with respect to the probe potential shows peaks revealing fast <span class="hlt">electrons</span> at specific energies arising due to <span class="hlt">plasma</span> chemical reactions. The devices may be applicable for developing analytical sensors for extreme environments, including high radiation and vibration levels and high temperatures. This work was performed while VID held a NRC Research Associateship Award at AFRL.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2006APS..GECBT2001B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2006APS..GECBT2001B"><span><span class="hlt">Electron</span> Sheaths and Non-ambipolar Diffusion in Laboratory <span class="hlt">Plasma</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Baalrud, Scott; Hershkowitz, Noah</p> <p>2006-10-01</p> <p><span class="hlt">Electron</span> sheaths were first predicted by Langmuir in 1929 when he stated that, ``with a large area, A, an anode sheath is a positive ion sheath, but that as A decreases, a point is reached where the positive ion sheath disappears and it is replaced by an <span class="hlt">electron</span> sheath.''. We show that <span class="hlt">electron</span> sheath formation near a positive anode depends on the anode area, Aa, as well as the area available for ion loss, Ai. When Aa/Ai< (me/mi)^1/2, the <span class="hlt">electron</span> sheath potential monotonically decreases from the anode to the bulk <span class="hlt">plasma</span>. When the anode is larger than this, a potential dip forms in the <span class="hlt">electron</span> sheath to reduce the <span class="hlt">electron</span> current lost to the anode. This potential dip is necessary to preserve global current balance and when it is present, total non-ambipolar diffusion can occur where all <span class="hlt">electrons</span> are lost from the <span class="hlt">plasma</span> through an <span class="hlt">electron</span> sheath and all positive ions are lost elsewhere. Additional measurements were carried out to identify the transition from positive (ion) to negative (<span class="hlt">electron</span>) sheaths. Data were taken in low-pressure argon <span class="hlt">plasma</span> generated by hot filaments and confined in a multidipole chamber. I. Langmuir, Physical Review. 33, 954 (1929).</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/23277987','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/23277987"><span>Separation of finite <span class="hlt">electron</span> temperature effect on <span class="hlt">plasma</span> polarimetry.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Imazawa, Ryota; Kawano, Yasunori; Kusama, Yoshinori</p> <p>2012-12-01</p> <p>This study demonstrates the separation of the finite <span class="hlt">electron</span> temperature on the <span class="hlt">plasma</span> polarimetry in the magnetic confined fusion <span class="hlt">plasma</span> for the first time. Approximate solutions of the transformed Stokes equation, including the relativistic effect, suggest that the orientation angle, θ, and ellipticity angle, ε, of polarization state have different dependency on the <span class="hlt">electron</span> density, n(e), and the <span class="hlt">electron</span> temperature, T(e), and that the separation of n(e) and T(e) from θ and ε is possible in principle. We carry out the equilibrium and kinetic reconstruction of tokamak <span class="hlt">plasma</span> when the central <span class="hlt">electron</span> density was 10(20) m(-3), and the central <span class="hlt">electron</span> temperatures were 5, 10, 20, and 30 keV. For both cases when a total <span class="hlt">plasma</span> current, I(p), is known and when I(p) is unknown, the profiles of <span class="hlt">plasma</span> current density, j(φ), n(e), and T(e) are successfully reconstructed. The reconstruction of j(φ) without the information of I(p) indicates the new method of I(p) measurement applicable to steady state operation of tokamak.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/22094033','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/22094033"><span>Separation of finite <span class="hlt">electron</span> temperature effect on <span class="hlt">plasma</span> polarimetry</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Imazawa, Ryota; Kawano, Yasunori; Kusama, Yoshinori</p> <p>2012-12-15</p> <p>This study demonstrates the separation of the finite <span class="hlt">electron</span> temperature on the <span class="hlt">plasma</span> polarimetry in the magnetic confined fusion <span class="hlt">plasma</span> for the first time. Approximate solutions of the transformed Stokes equation, including the relativistic effect, suggest that the orientation angle, {theta}, and ellipticity angle, {epsilon}, of polarization state have different dependency on the <span class="hlt">electron</span> density, n{sub e}, and the <span class="hlt">electron</span> temperature, T{sub e}, and that the separation of n{sub e} and T{sub e} from {theta} and {epsilon} is possible in principle. We carry out the equilibrium and kinetic reconstruction of tokamak <span class="hlt">plasma</span> when the central <span class="hlt">electron</span> density was 10{sup 20} m{sup -3}, and the central <span class="hlt">electron</span> temperatures were 5, 10, 20, and 30 keV. For both cases when a total <span class="hlt">plasma</span> current, I{sub p}, is known and when I{sub p} is unknown, the profiles of <span class="hlt">plasma</span> current density, j{sub {phi}}, n{sub e}, and T{sub e} are successfully reconstructed. The reconstruction of j{sub {phi}} without the information of I{sub p} indicates the new method of I{sub p} measurement applicable to steady state operation of tokamak.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010APS..DPPGI3005S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010APS..DPPGI3005S"><span>Formation of High-Beta <span class="hlt">Plasma</span> and Stable Confinement of Toroidal <span class="hlt">Electron</span> <span class="hlt">Plasma</span> in RT-1</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Saitoh, Haruhiko</p> <p>2010-11-01</p> <p>The Ring Trap 1 (RT-1) device is a laboratory magnetosphere generated by a levitated superconducting magnet. The goals of RT-1 are to realize stable formation of ultra high-beta <span class="hlt">plasma</span> suitable for burning advanced fusion fuels, and confinement of toroidal non-neutral <span class="hlt">plasmas</span> including antimatter particles. RT- 1 has produced high-beta <span class="hlt">plasma</span> in the magnetospheric configuration. The effects of coil levitation and geomagnetic field compensation [Y. Yano et al., <span class="hlt">Plasma</span> Fusion Res. 4, 039] resulted drastic improvements of the <span class="hlt">plasma</span> properties, and a maximum local beta value exceeded 70%. Because <span class="hlt">plasma</span> is generated by <span class="hlt">electron</span> cyclotron resonance heating (ECH) in the present experiment, the <span class="hlt">plasma</span> pressure is mainly due to hot <span class="hlt">electrons</span>, whose bremsstrahlung was observed with an x-ray CCD camera. The pressure profiles have rather steep gradient near the superconducting coil in the strong field region. The decay rates of magnetic probe and interferometer signals have different time constants, suggesting multiple temperature components. The energy confinement time estimated from the input RF power and stored magnetic energy is on the order of 1s, which is comparable to the decay time constant of the density of hot <span class="hlt">electron</span> component. Pure <span class="hlt">electron</span> <span class="hlt">plasma</span> experiments are also conducted in RT-1. Radial profiles of electrostatic potential and <span class="hlt">electron</span> density showed that the <span class="hlt">plasma</span> rigidly rotates in the toroidal direction in the stable confinement phase. Long time confinement of toroidal non- neutral <span class="hlt">plasma</span> for more than 300s and inward particle diffusion to strong field regions, caused by the activation of the diocotron (Kelvin-Helmholtz) instability, have been realized [Z. Yoshida et al., Phys. Rev. Lett. 104, 235004].</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/9100','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/9100"><span>Self-effect in expanding <span class="hlt">electron</span> beam <span class="hlt">plasma</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Garcia, M</p> <p>1999-05-07</p> <p>An analytical model of <span class="hlt">plasma</span> flow from a metal plate hit by an intense, pulsed, <span class="hlt">electron</span> beam aims to bridge the gap between radiation-hydrodynamics simulations and experiments, and to quantify the self-effect of the <span class="hlt">electron</span> beam penetrating the flow. Does the flow disrupt the tight focus of the initial <span class="hlt">electron</span> bunch, or later pulses in a train? This work aims to model the spatial distribution of <span class="hlt">plasma</span> speed, density, degree of ionization, and magnetization to inquire. The initial solid density, several eV <span class="hlt">plasma</span> expands to 1 cm and 10{sup {minus}4} relative density by 2 {micro}s, beyond which numerical simulations are imprecise. Yet, a Faraday cup detector at the ETA-II facility is at 25 cm from the target and observes the flow after 50 {micro}s. The model helps bridge this gap. The expansion of the target <span class="hlt">plasma</span> into vacuum is so rapid that the ionized portion of the flow departs from local thermodynamic equilibrium. When the temperature (in eV) in a parcel of fluid drops below V{sub i} x [(2{gamma} - 2)/(5{gamma} + 17)], where V{sub i} is the ionization potential of the target metal (7.8 eV for tantalum), and {gamma} is the ratio of specific heats (5/3 for atoms), then the fractional ionization and <span class="hlt">electron</span> temperature in that parcel remain fixed during subsequent expansion. The freezing temperature as defined here is V{sub i}/19. The balance between the self-pinching force and the space charge repulsion of an <span class="hlt">electron</span> beam changes on penetrating a flow: (i) the target <span class="hlt">plasma</span> cancels the space-charge field, (ii) internal eddy currents arise to counter the magnetization of relativistic <span class="hlt">electrons</span>, and (iii) <span class="hlt">electron</span> beam heating alters the flow magnetization by changing the <span class="hlt">plasma</span> density gradient and the magnitude of the conductivity.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/22471828','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/22471828"><span>Ribbon <span class="hlt">electron</span> beam formation by a forevacuum <span class="hlt">plasma</span> <span class="hlt">electron</span> source</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Klimov, A. S. Burdovitsin, V. A.; Grishkov, A. A.; Oks, E. M.; Zenin, A. A.; Yushkov, Yu. G.</p> <p>2016-01-15</p> <p>Results of the numerical analysis and experimental research on ribbon <span class="hlt">electron</span> beam generation based on hollow cathode discharge at forevacuum gas pressure are presented. Geometry of the accelerating gap has modified. It lets us focus the ribbon <span class="hlt">electron</span> beam and to transport it on a distance of several tens of centimeters in the absence of an axial magnetic field. The results of numerical simulations are confirmed by the experiment.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/5004868','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/5004868"><span>Kinetics of <span class="hlt">plasma</span> <span class="hlt">electrons</span> in static and rf fields</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Ivanov, Y.A.; Lebedev, Y.A.; Polak, L.S.</p> <p>1980-01-01</p> <p>The effect of the frequency of the field producing a <span class="hlt">plasma</span> on the isotropic part of the <span class="hlt">electron</span> energy distribution is analyzed. Analytic solutions of the Boltzmann equation are derived for high-energy tail of the <span class="hlt">electron</span> energy distribution for static and rf fields. The results show that the shape of the tail of the distribution can be effectively controlled by changing the ratio of the field frequency to the effective frequency with which <span class="hlt">electrons</span> collide with heavy particles and by choosing the appropriate dependence of the cross section for elastic scattering of <span class="hlt">electrons</span> by heavy particles on the <span class="hlt">electron</span> energy (by appropriate choice of the gas from which the <span class="hlt">plasma</span> is formed). These results agree with experimental results in the literature.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/21255224','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/21255224"><span>Direct Acceleration of <span class="hlt">Electrons</span> in a Corrugated <span class="hlt">Plasma</span> Channel</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Palastro, J. P.; Antonsen, T. M.; Morshed, S.; York, A. G.; Layer, B.; Aubuchon, M.; Milchberg, H. M.; Froula, D. H.</p> <p>2009-01-22</p> <p>Direct laser acceleration of <span class="hlt">electrons</span> provides a low power tabletop alternative to laser wakefield accelerators. Until recently, however, direct acceleration has been limited by diffraction, phase matching, and material damage thresholds. The development of the corrugated <span class="hlt">plasma</span> channel [B. Layer et al., Phys. Rev. Lett. 99, 035001 (2007)] has removed all of these limitations and promises to allow direct acceleration of <span class="hlt">electrons</span> over many centimeters at high gradients using femtosecond lasers [A. G. York et al., Phys Rev. Lett 100, 195001 (2008), J. P. Palastro et al., Phys. Rev. E 77, 036405 (2008)]. We present a simple analytic model of laser propagation in a corrugated <span class="hlt">plasma</span> channel and examine the laser-<span class="hlt">electron</span> beam interaction. Simulations show accelerating gradients of several hundred MeV/cm for laser powers much lower than required by standard laser wakefield schemes. In addition, the laser provides a transverse force that confines the high energy <span class="hlt">electrons</span> on axis, while expelling low energy <span class="hlt">electrons</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19870053861&hterms=1076&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3D%2526%25231076','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19870053861&hterms=1076&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3D%2526%25231076"><span><span class="hlt">Plasma</span> properties in <span class="hlt">electron</span>-bombardment ion thrusters</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Matossian, J. N.; Beattie, J. R.</p> <p>1987-01-01</p> <p>The paper describes a technique for computing volume-averaged <span class="hlt">plasma</span> properties within <span class="hlt">electron</span>-bombardment ion thrusters, using spatially varying Langmuir-probe measurements. Average values of the <span class="hlt">electron</span> densities are defined by integrating the spatially varying Maxwellian and primary <span class="hlt">electron</span> densities over the ionization volume, and then dividing by the volume. <span class="hlt">Plasma</span> properties obtained in the 30-cm-diameter J-series and ring-cusp thrusters are analyzed by the volume-averaging technique. The superior performance exhibited by the ring-cusp thruster is correlated with a higher average Maxwellian <span class="hlt">electron</span> temperature. The ring-cusp thruster maintains the same fraction of primary <span class="hlt">electrons</span> as does the J-series thruster, but at a much lower ion production cost. The volume-averaged predictions for both thrusters are compared with those of a detailed thruster performance model.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1997APS..GECOWP218Q','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1997APS..GECOWP218Q"><span><span class="hlt">Electron</span> Beam Biasing of Substrates during <span class="hlt">Plasma</span> Etching [1</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Quick, A. K.; Hershkowitz, N.</p> <p>1997-10-01</p> <p><span class="hlt">Electron</span> beam biasing of substrates is being studied as an alternative to the usual method of using a capacitively coupled, rf-powered wafer chuck. The advantage of biasing with an <span class="hlt">electron</span> beam is that the <span class="hlt">electrons</span> which arrive at the wafer do so with an anisotropic velocity distribution similar to the <span class="hlt">plasma</span> sheath-accelerated ions. This becomes important when etching large aspect ratio features. Isotropic <span class="hlt">plasma</span> <span class="hlt">electrons</span> can't follow the ions to the bottom of deep wells and they adhere to and charge up the feature sidewalls. This differential charging creates electric fields which deflect incoming ions and causes sidewall profile defects such as bowing, notching, and microtrenching and contributes to RIE(Reactive Ion Etch) lag( R. A. Gottscho, C. W. Jurgensen, and D. J. Vitkavage, J. Vac. Sci. Technol. B 10, Sep/Oct 1992, 2133.). The effects of etching sub-half micron nested poly-Silicon lines in Cl2 <span class="hlt">plasmas</span> in the presence of an <span class="hlt">electron</span> beam will be presented particularly in regard to notch suppression. The effects that the <span class="hlt">electron</span> beam has on RIE lag suppression in SiO2 etching in fluorocarbon <span class="hlt">plasmas</span> will also be discussed.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li class="active"><span>20</span></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_20 --> <div id="page_21" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li class="active"><span>21</span></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="401"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017NucFu..57a6033Y','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017NucFu..57a6033Y"><span><span class="hlt">Electron</span> cyclotron <span class="hlt">plasma</span> startup in the GDT experiment</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Yakovlev, D. V.; Shalashov, A. G.; Gospodchikov, E. D.; Solomakhin, A. L.; Savkin, V. Ya.; Bagryansky, P. A.</p> <p>2017-01-01</p> <p>We report on a new <span class="hlt">plasma</span> startup scenario in the gas dynamic trap (GDT) magnetic mirror device. The primary 5 MW neutral beam injection (NBI) <span class="hlt">plasma</span> heating system fires into a sufficiently dense <span class="hlt">plasma</span> target (‘seed plasma’), which is commonly supplied by an arc <span class="hlt">plasma</span> generator. In the reported experiments, a different approach to seed <span class="hlt">plasma</span> generation is explored. One of the channels of the <span class="hlt">electron</span> cyclotron resonance (ECR) heating system is used to ionize the neutral gas and build up the density of <span class="hlt">plasma</span> to a level suitable for NBI capture. After a short transition of approximately 1 ms the discharge becomes essentially similar to a standard one initiated by the <span class="hlt">plasma</span> gun. This paper presents the discharge scenario and experimental data on the seed <span class="hlt">plasma</span> evolution during ECRH, along with the dependencies on incident microwave power, magnetic configuration and pressure of a neutral gas. The characteristics of the consequent high-power NBI discharge are studied and differences from the conventional scenario are discussed. A theoretical model describing the ECR breakdown and the seed <span class="hlt">plasma</span> accumulation in a large-scale mirror trap is developed on the basis of the GDT experiment.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014MNRAS.439..924B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014MNRAS.439..924B"><span>Transparency of an instantaneously created <span class="hlt">electron</span>-positron-photon <span class="hlt">plasma</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Bégué, D.; Vereshchagin, G. V.</p> <p>2014-03-01</p> <p>The problem of the expansion of a relativistic <span class="hlt">plasma</span> generated when a large amount of energy is released in a small volume has been considered by many authors. We use the analytical solution of Bisnovatyi-Kogan and Murzina for the spherically symmetric relativistic expansion. The light curves and the spectra from transparency of an <span class="hlt">electron</span>-positron-photon <span class="hlt">plasma</span> are obtained. We compare our results with the work of Goodman.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/20699677','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/20699677"><span>Collisionless Reconnection in an <span class="hlt">Electron</span>-Positron <span class="hlt">Plasma</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Bessho, N.; Bhattacharjee, A.</p> <p>2005-12-09</p> <p>Electromagnetic particle-in-cell simulations of fast collisionless reconnection in a two-dimensional <span class="hlt">electron</span>-positron <span class="hlt">plasma</span> (without an equilibrium guide field) are presented. A generalized Ohm's law in which the Hall current cancels out exactly is given. It is suggested that the key to fast reconnection in this <span class="hlt">plasma</span> is the localization caused by the off-diagonal components of the pressure tensors, which produce an effect analogous to a spatially localized resistivity.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013AGUFMSM51D..03F','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013AGUFMSM51D..03F"><span>Cluster observations of the <span class="hlt">plasma</span> <span class="hlt">sheet</span> at very high latitudes: The in situ signature of a transpolar arc</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Fear, R. C.; Milan, S. E.; Maggiolo, R.</p> <p>2013-12-01</p> <p>Transpolar arcs are auroral features which extend into the polar cap, which is the dim region poleward of the main auroral oval. Several case and statistical studies have shown that they are formed by the closure of lobe magnetic flux by magnetotail reconnection, and that the transpolar arc forms at the footprints of the newly-closed field lines which are embedded within the open flux of the polar cap. Therefore, when transpolar arcs occur, the magnetotail should contain closed magnetic field lines even at high latitudes (but in a localised sector), embedded within the open lobe flux. We present in situ observations of this phenomenon, taken by the Cluster spacecraft on 15th September 2005. Cluster was located at high latitudes in the southern hemisphere lobe (far from the typical location of the <span class="hlt">plasma</span> <span class="hlt">sheet</span>), and a transpolar arc was observed by the FUV cameras on the IMAGE satellite. An initial analysis reveals that Cluster periodically observed <span class="hlt">plasma</span> similar to a typical <span class="hlt">plasma</span> <span class="hlt">sheet</span> distribution, but at much higher latitudes - indicative of closed flux embedded within the high latitude lobe. Each time that this <span class="hlt">plasma</span> distribution was observed, the footprint of the spacecraft mapped to the transpolar arc (significantly poleward of the main auroral oval). These observations are consistent with closed flux being trapped in the magnetotail and embedded within the lobe, and provide further evidence for transpolar arcs being formed by magnetotail reconnection.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2011APS..GECSF1001K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011APS..GECSF1001K"><span>Application of Nonlocal <span class="hlt">Electron</span> Kinetics to <span class="hlt">Plasma</span> Technologies</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kaganovich, Igor D.</p> <p>2011-10-01</p> <p>Partially ionized <span class="hlt">plasmas</span> are typically in a highly non-equilibrium thermodynamic state: the <span class="hlt">electrons</span> are not in equilibrium with the neutral particle species or the ions, and the <span class="hlt">electrons</span> are also not in equilibrium within their own ensemble, which results in a significant departure of the <span class="hlt">electron</span> velocity distribution function (EVDF) from a Maxwellian. These non-equilibrium conditions provide considerable freedom to choose optimal <span class="hlt">plasma</span> parameters for applications, which make gas-discharge <span class="hlt">plasmas</span> remarkable tools for a variety of <span class="hlt">plasma</span> applications, including <span class="hlt">plasma</span> processing, discharge lighting, <span class="hlt">plasma</span> propulsion, particle beam sources, and nanotechnology. Significant progress in understanding the formation of non-Maxwellian EVDF in the self-consistent electric fields has been one of the major achievements in the low-temperature <span class="hlt">plasmas</span> during the last decade. This progress was made possible by a synergy between full-scale particle-in-cell simulations, analytical models, and experiments. Specific examples include rf discharges, dc discharges with auxiliary electrodes, Hall thruster discharges. In each example, nonlocal kinetic effects are identified as the main mechanisms responsible for the surprising degree of discharge self-organization. These phenomena include: explosive generation of cold <span class="hlt">electrons</span> with rf power increase in low-pressure rf discharges; abrupt changes in discharge structure with increased bias voltage on a third electrode in a dc discharge with hot cathode; absence of a steady-state regime in Hall thruster discharges with intense secondary <span class="hlt">electron</span> emission due to coupling of the sheath properties and the EVDF. In collaboration with Y. Raitses, A.V. Khrabrov, M. Campanell, V. I. Demidov, D. Sydorenko, I. Schweigert, and A. S. Mustafaev. Research supported by the U.S. Department of Energy.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/21123878','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/21123878"><span>Confinement Time Exceeding One Second for a Toroidal <span class="hlt">Electron</span> <span class="hlt">Plasma</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Marler, J. P.; Stoneking, M. R.</p> <p>2008-04-18</p> <p>Nearly steady-state <span class="hlt">electron</span> <span class="hlt">plasmas</span> are trapped in a toroidal magnetic field for the first time. We report the first results from a new toroidal <span class="hlt">electron</span> <span class="hlt">plasma</span> experiment, the Lawrence Non-neutral Torus II, in which <span class="hlt">electron</span> densities on the order of 10{sup 7} cm{sup -3} are trapped in a 270 deg. toroidal arc (670 G toroidal magnetic field) by application of trapping potentials to segments of a conducting shell. The total charge inferred from measurements of the frequency of the m=1 diocotron mode is observed to decay on a 3 s time scale, a time scale that approaches the predicted limit due to magnetic pumping transport. Three seconds represents {approx_equal}10{sup 5} periods of the lowest frequency <span class="hlt">plasma</span> mode, indicating that nearly steady-state conditions are achieved.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/6448679','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/6448679"><span>Permanent magnet <span class="hlt">electron</span> cyclotron resonance <span class="hlt">plasma</span> source with remote window</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Berry, L.A.; Gorbatkin, S.M. )</p> <p>1995-03-01</p> <p>An <span class="hlt">electron</span> cyclotron resonance (ECR) <span class="hlt">plasma</span> has been used in conjunction with a solid metal sputter target for Cu deposition over 200 mm diameters. The goal is to develop a deposition system and process suitable for filling submicron, high-aspect ratio ULSI features. The system uses a permanent magnet for creation of the magnetic field necessary for ECR, and is significantly more compact than systems equipped with electromagnets. A custom launcher design allows remote microwave injection with the microwave entrance window shielded from the copper flux. When microwaves are introduced at an angle with respect to the <span class="hlt">plasma</span>, high <span class="hlt">electron</span> densities can be produced with a <span class="hlt">plasma</span> frequency significantly greater than the <span class="hlt">electron</span> cyclotron frequency. Copper deposition rates of 1000 A/min have been achieved.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19800046372&hterms=Haber+process&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3DHaber%2Bprocess','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19800046372&hterms=Haber+process&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3DHaber%2Bprocess"><span>Strongly turbulent stabilization of <span class="hlt">electron</span> beam-<span class="hlt">plasma</span> interactions</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Freund, H. P.; Haber, I.; Palmadesso, P.; Papadopoulos, K.</p> <p>1980-01-01</p> <p>The stabilization of <span class="hlt">electron</span> beam interactions due to strongly turbulent nonlinearities is studied analytically and numerically for a wide range of <span class="hlt">plasma</span> parameters. A fluid mode coupling code is described in which the effects of <span class="hlt">electron</span> and ion Landau damping and linear growth due to the energetic <span class="hlt">electron</span> beam are included in a phenomenological manner. Stabilization of the instability is found to occur when the amplitudes of the unstable modes exceed the threshold of the oscillating two-stream instability. The coordinate space structure of the turbulent spectrum which results clearly shows that soliton-like structures are formed by this process. Phenomenological models of both the initial stabilization and the asymptotic states are developed. Scaling laws between the beam-<span class="hlt">plasma</span> growth rate and the fluctuations in the fields and <span class="hlt">plasma</span> density are found in both cases, and shown to be in good agreement with the results of the simulation.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016JaJAP..55gLG08Y','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016JaJAP..55gLG08Y"><span>Characteristics of surface sterilization using <span class="hlt">electron</span> cyclotron resonance <span class="hlt">plasma</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Yonesu, Akira; Hara, Kazufumi; Nishikawa, Tatsuya; Hayashi, Nobuya</p> <p>2016-07-01</p> <p>The characteristics of surface sterilization using <span class="hlt">electron</span> cyclotron resonance (ECR) <span class="hlt">plasma</span> were investigated. High-energy <span class="hlt">electrons</span> and oxygen radicals were observed in the ECR zone using electric probe and optical emission spectroscopic methods. A biological indicator (BI), Geobacillus stearothermophilus, containing 1 × 106 spores was sterilized in 120 s by exposure to oxygen discharges while maintaining a temperature of approximately 55 °C at the BI installation position. Oxygen radicals and high-energy <span class="hlt">electrons</span> were found to be the sterilizing species in the ECR region. It was demonstrated that the ECR <span class="hlt">plasma</span> could be produced in narrow tubes with an inner diameter of 5 mm. Moreover, sterilization tests confirmed that the spores present inside the narrow tube were successfully inactivated by ECR <span class="hlt">plasma</span> irradiation.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013Ap%26SS.346..359H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013Ap%26SS.346..359H"><span>Magnetoacoustic solitons in dense astrophysical <span class="hlt">electron</span>-positron-ion <span class="hlt">plasmas</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Hussain, S.; Mahmood, S.; Mushtaq, A.</p> <p>2013-08-01</p> <p>Nonlinear magnetoacoustic waves in dense <span class="hlt">electron</span>-positron-ion <span class="hlt">plasmas</span> are investigated by using three fluid quantum magnetohydrodynamic model. The quantum mechanical effects of <span class="hlt">electrons</span> and positrons are taken into account due to their Fermionic nature (to obey Fermi statistics) and quantum diffraction effects (Bohm diffusion term) in the model. The reductive perturbation method is employed to derive the Korteweg-de Vries (KdV) equation for low amplitude magnetoacoustic soliton in dense <span class="hlt">electron</span>-positron-ion <span class="hlt">plasmas</span>. It is found that positron concentration has significant impact on the phase velocity of magnetoacoustic wave and on the formation of single pulse nonlinear structure. The numerical results are also illustrated by taking into account the <span class="hlt">plasma</span> parameters of the outside layers of white dwarfs and neutron stars/pulsars.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19920029434&hterms=plasma+simulation&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D90%26Ntt%3Dplasma%2Bsimulation','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19920029434&hterms=plasma+simulation&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D90%26Ntt%3Dplasma%2Bsimulation"><span>Simulation of the nonlinear evolution of <span class="hlt">electron</span> <span class="hlt">plasma</span> waves</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Nishikawa, K.-I.; Cairns, I. H.</p> <p>1991-01-01</p> <p>Electrostatic waves driven by an <span class="hlt">electron</span> beam in an ambient magnetized <span class="hlt">plasma</span> were studied using a quasi-1D PIC simulation of <span class="hlt">electron</span> <span class="hlt">plasma</span> waves (i.e., Langmuir waves). The results disclose the presence of a process for moving wave energy from frequencies and wavenumbers predicted by linear theory to the Langmuir-like frequencies during saturation of the instability. A decay process for producing backward propagating Langmuir-like waves, along with low-frequency waves, is observed. The simulation results, however, indicate that the backscattering process is not the conventional Langmuir wave decay. Electrostatic waves near multiples of the <span class="hlt">electron</span> <span class="hlt">plasma</span> frequency are generated by wave-wave coupling during the nonlinear stage of the simulations, confirming the suggestion of Klimas (1983).</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014PhPl...21i2108A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014PhPl...21i2108A"><span>Anomalous skin effects in a weakly magnetized degenerate <span class="hlt">electron</span> <span class="hlt">plasma</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Abbas, G.; Sarfraz, M.; Shah, H. A.</p> <p>2014-09-01</p> <p>Fully relativistic analysis of anomalous skin effects for parallel propagating waves in a weakly magnetized degenerate <span class="hlt">electron</span> <span class="hlt">plasma</span> is presented and a graphical comparison is made with the results obtained using relativistic Maxwellian distribution function [G. Abbas, M. F. Bashir, and G. Murtaza, Phys. <span class="hlt">Plasmas</span> 18, 102115 (2011)]. It is found that the penetration depth for R- and L-waves for degenerate case is qualitatively small in comparison with the Maxwellian <span class="hlt">plasma</span> case. The quantitative reduction due to weak magnetic field in the skin depth in R-wave for degenerate <span class="hlt">plasma</span> is large as compared to the non-degenerate one. By ignoring the ambient magnetic field, previous results for degenerate field free case are salvaged [A. F. Alexandrov, A. S. Bogdankevich, and A. A. Rukhadze, Principles of <span class="hlt">Plasma</span> Electrodynamics (Springer-Verlag, Berlin/Heidelberg, 1984), p. 90].</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/22303618','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/22303618"><span>Anomalous skin effects in a weakly magnetized degenerate <span class="hlt">electron</span> <span class="hlt">plasma</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Abbas, G. Sarfraz, M.; Shah, H. A.</p> <p>2014-09-15</p> <p>Fully relativistic analysis of anomalous skin effects for parallel propagating waves in a weakly magnetized degenerate <span class="hlt">electron</span> <span class="hlt">plasma</span> is presented and a graphical comparison is made with the results obtained using relativistic Maxwellian distribution function [G. Abbas, M. F. Bashir, and G. Murtaza, Phys. <span class="hlt">Plasmas</span> 18, 102115 (2011)]. It is found that the penetration depth for R- and L-waves for degenerate case is qualitatively small in comparison with the Maxwellian <span class="hlt">plasma</span> case. The quantitative reduction due to weak magnetic field in the skin depth in R-wave for degenerate <span class="hlt">plasma</span> is large as compared to the non-degenerate one. By ignoring the ambient magnetic field, previous results for degenerate field free case are salvaged [A. F. Alexandrov, A. S. Bogdankevich, and A. A. Rukhadze, Principles of <span class="hlt">Plasma</span> Electrodynamics (Springer-Verlag, Berlin/Heidelberg, 1984), p. 90].</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/22489833','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/22489833"><span>Two-dimensional studies of relativistic <span class="hlt">electron</span> beam <span class="hlt">plasma</span> instabilities in an inhomogeneous <span class="hlt">plasma</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Shukla, Chandrasekhar; Das, Amita; Patel, Kartik</p> <p>2015-11-15</p> <p>Relativistic <span class="hlt">electron</span> beam propagation in <span class="hlt">plasma</span> is fraught with several micro instabilities like two stream, filamentation, etc., in <span class="hlt">plasma</span>. This results in severe limitation of the <span class="hlt">electron</span> transport through a <span class="hlt">plasma</span> medium. Recently, however, there has been an experimental demonstration of improved transport of Mega Ampere of <span class="hlt">electron</span> currents (generated by the interaction of intense laser with solid target) in a carbon nanotube structured solid target [G. Chatterjee et al., Phys. Rev. Lett. 108, 235005 (2012)]. This then suggests that the inhomogeneous <span class="hlt">plasma</span> (created by the ionization of carbon nanotube structured target) helps in containing the growth of the beam <span class="hlt">plasma</span> instabilities. This manuscript addresses this issue with the help of a detailed analytical study and 2-D Particle-In-Cell simulations. The study conclusively demonstrates that the growth rate of the dominant instability in the 2-D geometry decreases when the <span class="hlt">plasma</span> density is chosen to be inhomogeneous, provided the scale length 1/k{sub s} of the inhomogeneous <span class="hlt">plasma</span> is less than the typical <span class="hlt">plasma</span> skin depth (c/ω{sub 0}) scale. At such small scale lengths channelization of currents is also observed in simulation.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016JGRA..121.8361A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016JGRA..121.8361A"><span>Upper limit of <span class="hlt">electron</span> fluxes generated by kinetic Alfvén waves in Maxwellian <span class="hlt">plasma</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Artemyev, A. V.; Rankin, R.; Vasko, I. Y.</p> <p>2016-09-01</p> <p>We consider <span class="hlt">electron</span> acceleration by kinetic Alfvén waves in the equatorial inner magnetosphere and <span class="hlt">plasma</span> <span class="hlt">sheet</span> boundary layer. The competition between the accelerating effect of the wave parallel electric field and mirror force acting on particles in an inhomogeneous background magnetic field generates an effective potential well where <span class="hlt">electrons</span> can be trapped and accelerated. We compare energy variations of trapped and transient resonant <span class="hlt">electrons</span> and show that these variations almost compensate each other. Thus, energy provided to waves by transient particles is transferred to trapped particles. This effect allows waves accelerate trapped <span class="hlt">electrons</span> without being significantly damped. Using energy balance equations, we estimate the maximum flux of <span class="hlt">electrons</span> accelerated via trapping into Landau resonance with kinetic Alfvén waves. For a wide range of system parameters (i.e., ion to <span class="hlt">electron</span> temperature ratio, magnetic field amplitude, and wave number and wave frequency), acceleration of trapped <span class="hlt">electrons</span> can generate fluxes with amplitude about 5-25% of the background thermal fluxes. We determine parametric regions for the most efficient acceleration.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017SSCom.250...84Y','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017SSCom.250...84Y"><span><span class="hlt">Electronic</span> heat capacity and magnetic susceptibility of ferromagnetic silicene <span class="hlt">sheet</span> under strain</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Yarmohammadi, Mohsen</p> <p>2017-01-01</p> <p>The <span class="hlt">electronic</span> heat capacity (EHC) and magnetic susceptibility (MS) of the two-dimensional material ferromagnetic graphene's silicon analog, silicene, are investigated by the strain-induced and the applied electric field within the Green's function technique and the Kane-Mele Hamiltonian. Dirac cone approximation has been performed to investigate the system under strain along the zigzag (ZZ) direction. The main attention is focused on the effects of external static electric field in the presence of strain on EHC and MS of a ferromagnetic silicene <span class="hlt">sheet</span>. In the presence of strain, carriers have a larger effective mass and transport decreases. As a result, the temperature dependence of EHC and MS gives a critical strain around 10%. Furthermore, electric field breaks the reflection symmetry of the structure and a transition to the topological insulator for strained ferromagnetic silicene has occurred when the electric field is increased. In this phase, EHC and MS have weird behaviors with temperature.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1988PhRvA..37.2989F','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1988PhRvA..37.2989F"><span>Optical guiding in a <span class="hlt">sheet</span>-beam free-<span class="hlt">electron</span> laser</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Fruchtman, Amnon</p> <p>1988-04-01</p> <p><span class="hlt">Electron</span>-beam guiding of the amplified wave in the linear growth regime of a cavityless <span class="hlt">sheet</span>-beam FEL with a planar wiggler is investigated theoretically. The governing equations and the energy integral are derived; analytical results for beams with uniform and triangular density profiles and low or high values of Moore's (1985) coupling parameter (alpha) are obtained; and numerical results for intermediate values are presented in graphs. For low alpha, diffraction is large and the density profile does not affect gain and wave profile; for high alpha, there is significant optical guiding, the gain with a triangular beam is 2 exp 1/3 times higher than with a uniform beam, and the wave profile of the uniform-density beam remains confined to the beam volume.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/22494334','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/22494334"><span>On thermalization of <span class="hlt">electron</span>-positron-photon <span class="hlt">plasma</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Siutsou, I. A.; Aksenov, A. G.</p> <p>2015-12-17</p> <p>Recently a progress has been made in understanding thermalization mechanism of relativistic <span class="hlt">plasma</span> starting from a non-equilibrium state. Relativistic Boltzmann equations were solved numerically for homogeneous isotropic <span class="hlt">plasma</span> with collision integrals for two- and three-particle interactions calculated from the first principles by means of QED matrix elements. All particles were assumed to fulfill Boltzmann statistics. In this work we follow <span class="hlt">plasma</span> thermalization by accounting for Bose enhancement and Pauli blocking in particle interactions. Our results show that particle in equilibrium reach Bose-Einstein distribution for photons, and Fermi-Dirac one for <span class="hlt">electrons</span>, respectively.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012AGUFMSM21B2291C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012AGUFMSM21B2291C"><span>Adiabatic Phase Mixing and Fast <span class="hlt">Electron</span> Heating in Thin current <span class="hlt">Sheet</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Che, H.; Drake, J. F.; Swisdak, M. M.; Goldstein, M. L.</p> <p>2012-12-01</p> <p>Using particle-in-cell simulations and kinetic theory, it's found that strong Buneman instability develop non-linearly in thin current layer form in <span class="hlt">plasma</span> with Ω e/ω pe< 1. The Buneman instability produces strong electric field and fast phase mixing which leads to the increase of <span class="hlt">electron</span> temperature by more than a factor of 10 in a few tens of <span class="hlt">electron</span> gyro-periods. The resonance of wave-particles feeds waves with particle's kinetic energy and causes the growth of waves and strong trapping of <span class="hlt">electrons</span> at a large velocity range. We discovered it is the adiabatic movement of trapped <span class="hlt">electrons</span> produce fast phase mixing when the particle's bounce rate is much larger than the growth and decay rate of waves. The adiabatic movement effectively exchange energy between particles and waves and redistribute the energy from high velocity <span class="hlt">electrons</span> to low energy <span class="hlt">electrons</span> with the assistance of the non-adiabatic crossing of separatrix of <span class="hlt">electron</span> holes. The implications of the results for reconnection are being explored.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/22224163','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/22224163"><span>Influence of <span class="hlt">electron</span> injection into 27 cm audio <span class="hlt">plasma</span> cell on the <span class="hlt">plasma</span> diagnostics</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Haleem, N. A.; Ragheb, M. S.; Zakhary, S. G.; El Fiki, S. A.; Nouh, S. A.; El Disoki, T. M.</p> <p>2013-08-15</p> <p>In this article, the <span class="hlt">plasma</span> is created in a Pyrex tube (L = 27 cm, φ= 4 cm) as a single cell, by a capacitive audio frequency (AF) discharge (f = 10–100 kHz), at a definite pressure of ∼0.2 Torr. A couple of tube linear and deviating arrangements show <span class="hlt">plasma</span> characteristic conformity. The applied AF <span class="hlt">plasma</span> and the injection of <span class="hlt">electrons</span> into two gas mediums Ar and N{sub 2} revealed the increase of <span class="hlt">electron</span> density at distinct tube regions by one order to attain 10{sup 13}/cm{sup 3}. The <span class="hlt">electrons</span> temperature and density strengths are in contrast to each other. While their distributions differ along the <span class="hlt">plasma</span> tube length, they show a decaying sinusoidal shape where their peaks position varies by the gas type. The <span class="hlt">electrons</span> injection moderates <span class="hlt">electron</span> temperature and expands their density. The later highest peak holds for the N{sub 2} gas, at <span class="hlt">electrons</span> injection it changes to hold for the Ar. The sinusoidal decaying density behavior generates electric fields depending on the gas used and independent of tube geometry. The effect of the injected <span class="hlt">electrons</span> performs a responsive impact on <span class="hlt">electrons</span> density not attributed to the gas discharge. Analytical tools investigate the interaction of the <span class="hlt">plasma</span>, the discharge current, and the gas used on the electrodes. It points to the emigration of atoms from each one but for greater majority they behave to a preferred direction. Meanwhile, only in the linear regime, small percentage of atoms still moves in reverse direction. Traces of gas atoms revealed on both electrodes due to sheath regions denote lack of their participation in the discharge current. In addition, atoms travel from one electrode to the other by overcoming the sheaths regions occurring transportation of particles agglomeration from one electrode to the other. The <span class="hlt">electrons</span> injection has contributed to increase the <span class="hlt">plasma</span> <span class="hlt">electron</span> density peaks. These <span class="hlt">electrons</span> populations have raised the generated electrostatic fields assisting the elemental ions</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li class="active"><span>21</span></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_21 --> <div id="page_22" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li class="active"><span>22</span></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="421"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19790004462','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19790004462"><span>Multiple-satellite studies of magnetospheric substorms: <span class="hlt">Plasma</span> <span class="hlt">sheet</span> recovery and the poleward leap of auroral-zone activity</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Pytte, T.; Mcpherron, R. L.; Kivelson, M. G.; West, H. I., Jr.; Hones, E. W., Jr.</p> <p>1977-01-01</p> <p>Particle observations from pairs of satellites (Ogo 5, Vela 4A and 5B, Imp 3) during the recovery of <span class="hlt">plasma</span> <span class="hlt">sheet</span> thickness late in substorms were examined. Six of the nine events occurred within about 5 min in locations near the estimated position of the neutral <span class="hlt">sheet</span>, but over wide ranges of east-west and radial separations. The time of occurrence and spatial extent of the recovery were related to the onset (defined by ground Pi 2 pulsations) and approximate location (estimated from ground mid-latitude magnetic signatures) of substorm expansions. It was found that the <span class="hlt">plasma</span> <span class="hlt">sheet</span> recovery occurred 10 - 30 min after the last in a series of Pi bursts, which were interpreted to indicate that the recovery was not due directly to a late, high latitude substorm expansion. The recovery was also observed to occur after the substorm current wedge had moved into the evening sector and to extend far to the east of the center of the last preceding substorm expansion.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4979162','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4979162"><span>Easy-to-Use Preservation and Application of Platelet-Rich <span class="hlt">Plasma</span> in Combination Wound Therapy With a Gelatin <span class="hlt">Sheet</span> and Freeze-Dried Platelet-Rich <span class="hlt">Plasma</span>: A Case Report</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Kakudo, Natsuko; Ogura, Tsunekata; Hara, Tomoya; Matsui, Makoto; Yamamoto, Masaya; Tabata, Yasuhiko; Kusumoto, Kenji</p> <p>2016-01-01</p> <p>Objective: Platelet-rich <span class="hlt">plasma</span> is blood <span class="hlt">plasma</span> enriched with platelets and contains various growth factors. Two major issues remain to be resolved in the use of platelet-rich <span class="hlt">plasma</span>: the short biological activity after application, and the need to prepare platelet-rich <span class="hlt">plasma</span> at each application instance. To overcome these problems, we developed a drug delivery system using gelatin hydrogel and preserved the excess platelet-rich <span class="hlt">plasma</span> as freeze-dried platelet-rich <span class="hlt">plasma</span>. We then applied combination treatment with a gelatin <span class="hlt">sheet</span> and platelet-rich <span class="hlt">plasma</span> at the first instance and freeze-dried platelet-rich <span class="hlt">plasma</span> at the second instance in the treatment of a nonhealing wound. Methods: A 68-year-old woman had suffered open fracture of her right tibia 2 years prior, and a split-thickness skin graft had been applied to repair the skin defect on the right tibia. She had multiple relapse of ulcers, and the present ulcer had not healed for 2 months. After debridement, 2 mL of activated platelet-rich <span class="hlt">plasma</span> was applied to the ulcer, and the gelatin <span class="hlt">sheet</span> was laid to impregnate with the platelet-rich <span class="hlt">plasma</span>, after which the <span class="hlt">sheet</span> was covered with a polyurethane film. Thirty-three days after the first platelet-rich <span class="hlt">plasma</span> application, the freeze-dried platelet-rich <span class="hlt">plasma</span> was reconstituted and 2 mL of the reconstituted platelet-rich <span class="hlt">plasma</span> was applied with a gelatin <span class="hlt">sheet</span>. Results: At 14 days after the freeze-dried platelet-rich <span class="hlt">plasma</span> application, the wound was mostly epithelized, with the rest of the wound covered with granulation tissue. Conclusions: These findings suggest that combination wound therapy with a gelatin <span class="hlt">sheet</span> and freeze-dried platelet-rich <span class="hlt">plasma</span> is a promising method for resolving issues with conventional platelet-rich <span class="hlt">plasma</span> treatment. PMID:27555889</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19770034332&hterms=neutron+flux+distribution&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3Dneutron%2Bflux%2Bdistribution','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19770034332&hterms=neutron+flux+distribution&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3Dneutron%2Bflux%2Bdistribution"><span><span class="hlt">Electron</span> distribution function in a <span class="hlt">plasma</span> generated by fission fragments</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Hassan, H. A.; Deese, J. E.</p> <p>1976-01-01</p> <p>A Boltzmann equation formulation is presented for the determination of the <span class="hlt">electron</span> distribution function in a <span class="hlt">plasma</span> generated by fission fragments. The formulation takes into consideration ambipolar diffusion, elastic and inelastic collisions, recombination and ionization, and allows for the fact that the primary <span class="hlt">electrons</span> are not monoenergetic. Calculations for He in a tube coated with fissionable material shows that, over a wide pressure and neutron flux range, the distribution function is non-Maxwellian, but the <span class="hlt">electrons</span> are essentially thermal. Moreover, about a third of the energy of the primary <span class="hlt">electrons</span> is transferred into the inelastic levels of He. This fraction of energy transfer is almost independent of pressure and neutron flux.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/21466882','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/21466882"><span>Propagation of energetic <span class="hlt">electrons</span> in a hollow <span class="hlt">plasma</span> fiber</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Zhou, C. T.; He, X. T.; Chew, L. Y.</p> <p>2010-08-02</p> <p>Transport of energetic <span class="hlt">electrons</span> in a hollow <span class="hlt">plasma</span> fiber is investigated. The high-current <span class="hlt">electron</span> beam induces in the fiber strong radial electric fields and azimuthal magnetic fields on the inner and outer surfaces of the hollow fiber. The hot <span class="hlt">electrons</span> are pushed out by the surface magnetic field and returned into the fiber by the sheath electric field. Imbalance of the latter fields can drive chaotic oscillations of <span class="hlt">electrons</span> around the fiber wall. Intense thin return-current layers inside both the inner and outer wall surfaces are observed. This enhances local joule heating around both surfaces by the return current.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2003SSRv..105..627B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2003SSRv..105..627B"><span>The <span class="hlt">Plasma</span> Ion and <span class="hlt">Electron</span> Instruments for the Genesis Mission</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Barraclough, B. L.; Dors, E. E.; Abeyta, R. A.; Alexander, J. F.; Ameduri, F. P.; Baldonado, J. R.; Bame, S. J.; Casey, P. J.; Dirks, G.; Everett, D. T.; Gosling, J. T.; Grace, K. M.; Guerrero, D. R.; Kolar, J. D.; Kroesche, J. L., Jr.; Lockhart, W. L.; McComas, D. J.; Mietz, D. E.; Roese, J.; Sanders, J.; Steinberg, J. T.; Tokar, R. L.; Urdiales, C.; Wiens, R. C.</p> <p>2003-01-01</p> <p>The Genesis Ion Monitor (GIM) and the Genesis <span class="hlt">Electron</span> Monitor (GEM) provide 3-dimensional <span class="hlt">plasma</span> measurements of the solar wind for the Genesis mission. These measurements are used onboard to determine the type of <span class="hlt">plasma</span> that is flowing past the spacecraft and to configure the solar wind sample collection subsystems in real-time. Both GIM and GEM employ spherical-section electrostatic analyzers followed by channel <span class="hlt">electron</span> multiplier (CEM) arrays for detection and angle and energy/charge analysis of incident ions and <span class="hlt">electrons</span>. GIM is of a new design specific to Genesis mission requirements whereas the GEM sensor is an almost exact copy of the <span class="hlt">plasma</span> <span class="hlt">electron</span> sensors currently flying on the ACE and Ulysses spacecraft, albeit with new <span class="hlt">electronics</span> and programming. Ions are detected at forty log-spaced energy levels between ˜ 1 eV and 14 keV by eight CEM detectors, while <span class="hlt">electrons</span> with energies between ˜ 1 eV and 1.4 keV are measured at twenty log-spaced energy levels using seven CEMs. The spin of the spacecraft is used to sweep the fan-shaped fields-of-view of both instruments across all areas of the sky of interest, with ion measurements being taken forty times per spin and samples of the <span class="hlt">electron</span> population being taken twenty four times per spin. Complete ion and <span class="hlt">electron</span> energy spectra are measured every ˜ 2.5 min (four spins of the spacecraft) with adequate energy and angular resolution to determine fully 3-dimensional ion and <span class="hlt">electron</span> distribution functions. The GIM and GEM <span class="hlt">plasma</span> measurements are principally used to enable the operational solar wind sample collection goals of the Genesis mission but they also provide a potentially very useful data set for studies of solar wind phenomena, especially if combined with other solar wind data sets from ACE, WIND, SOHO and Ulysses for multi-spacecraft investigations.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015APS..DPPTP2160P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015APS..DPPTP2160P"><span>Characterization of Secondary <span class="hlt">Electron</span> Emission Properties of <span class="hlt">Plasma</span> Facing Materials</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Patino, Marlene I.; Capece, Angela M.; Raitses, Yevgeny; Koel, Bruce E.</p> <p>2015-11-01</p> <p>The behavior of wall-bounded <span class="hlt">plasmas</span> is significantly affected by the <span class="hlt">plasma</span>-wall interactions, including the emission of secondary <span class="hlt">electrons</span> (SEE) from the wall materials due to bombardment by primary <span class="hlt">electrons</span>. The importance of SEE has prompted previous investigations of SEE properties of materials especially with applications to magnetic fusion, <span class="hlt">plasma</span> thrusters, and high power microwave devices. In this work, we present results of measurements of SEE properties of graphite and lithium materials relevant for the divertor region of magnetic fusion devices. Measurements of total SEE yield (defined as the number of emitted secondary <span class="hlt">electrons</span> per incident primary <span class="hlt">electron</span>) for lithium are extended up to 5 keV primary <span class="hlt">electron</span> energy, and the energy distributions of secondary <span class="hlt">electrons</span> are provided for graphite and lithium. Additionally, the effect of contamination on the total SEE yield of lithium was explored by exposing the material to water vapor. Auger <span class="hlt">electron</span> spectroscopy (AES) was used to determine surface composition and temperature programmed desorption (TPD) was used to determine lithium film thickness. Results show an order of magnitude increase in total SEE yield for lithium exposed to water vapor. This work was supported by DOE contract DE-AC02-09CH11466; AFOSR grants FA9550-14-1-0053, FA9550-11-1-0282, and AF9550-09-1-0695; and DOE Office of Science Graduate Student Research Program.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/20860240','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/20860240"><span>Nonlocal <span class="hlt">electron</span> transport in magnetized <span class="hlt">plasmas</span> with arbitrary atomic number</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Bennaceur-Doumaz, D.; Bendib, A.</p> <p>2006-09-15</p> <p>The numerical solution of the steady-state <span class="hlt">electron</span> Fokker-Planck equation perturbed with respect to a global equilibrium is presented in magnetized <span class="hlt">plasmas</span> with arbitrary atomic number Z. The magnetic field is assumed to be constant and the <span class="hlt">electron-electron</span> collisions are described by the Landau collision operator. The solution is derived in the Fourier space and in the framework of the diffusive approximation which captures the spatial nonlocal effects. The transport coefficients are deduced and used to close a complete set of nonlocal <span class="hlt">electron</span> fluid equations. This work improves the results of A. Bendib et al. [Phys. <span class="hlt">Plasmas</span> 9, 1555 (2002)] and of A. V. Brantov et al. [Phys. <span class="hlt">Plasmas</span> 10, 4633 (2003)] restricted to the local and nonlocal high-Z <span class="hlt">plasma</span> approximations, respectively. The influence of the magnetic field on the nonlocal effects is discussed. We propose also accurate numerical fits of the relevant transport coefficients with respect to the collisionality parameter {lambda}{sub ei}/L and the atomic number Z, where L is the typical scale length and {lambda}{sub ei} is the <span class="hlt">electron</span>-ion mean-free-path.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016APS..DPPBO6011T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016APS..DPPBO6011T"><span>Laser-<span class="hlt">plasma</span> mirrors: from <span class="hlt">electron</span> acceleration to harmonics generation</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Thévenet, Maxence; Bocoum, Maïmouna; Faure, Jérôme; Leblanc, Adrien; Vincenti, Henri; Quéré, Fabien</p> <p>2016-10-01</p> <p>Accelerating <span class="hlt">electrons</span> in the > 10 TV/m fields inside an ultrashort ultraintense laser pulse has been a long-standing goal in experimental physics, motivated by promising theoretical predictions. The biggest hurdle was to have <span class="hlt">electrons</span> injected in the center of the laser pulse. Recent experimental and numerical results showed that this problem could be solved using a <span class="hlt">plasma</span> mirror, i.e. an overdense <span class="hlt">plasma</span> with a sharp (<laser wavelength) density gradient on its front side, leading to a 10 MeV 3 nC <span class="hlt">electron</span> beam. Using particle-in-cell simulations, the ejection process was identified as a push-pull mechanism occuring at each laser period, resulting in a train of attosecond <span class="hlt">electron</span> bunches injected in the reflected field. We present a study and a model of this process, and show the gradient characteristic length is the crucial parameter for this phenomenon. Finally, the <span class="hlt">electron</span> ejection process was put into perspective with respect to the high harmonic generation mechanisms on <span class="hlt">plasma</span> mirrors, giving new insights into the motion of the <span class="hlt">plasma</span> mirror surface. funded by the European Research Council, Contract No. 306708, ERC Starting Grant FEMTOELEC.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2005APS..DPPBP1031K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2005APS..DPPBP1031K"><span>Hot <span class="hlt">Electron</span> Instability in a Dipole Confined <span class="hlt">Plasma</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kesner, J.; Mauel, M. E.</p> <p>2005-10-01</p> <p>In <span class="hlt">plasma</span> containing energetic <span class="hlt">electrons</span>, two interacting collective modes, an MHD-like mode and a hot <span class="hlt">electron</span> interchange (HEI) modeootnotetextN. A. Krall, Phys. Fluids, 9, 820 (1966)., may be present. The linear stability of interchange modes in a z-pinch at arbitrary beta, including a bulk and hot <span class="hlt">electron</span> species was recently studiedootnotetextN. Krasheninnikova, P. J. Catto, Phys. <span class="hlt">Plasmas</span>, 12, 32101 (2005).. Using the dispersion relation derived in this reference we show that when necessary conditions are satisfied the two modes may be present or absent in a closed-field line magnetic confinement geometry such as a hard core z-pinch or a dipole. The HEI instability and the MHD-like centrifugally-driven mode have been studied previouslyootnotetextB. Levitt, et al., Phys. <span class="hlt">Plasmas</span>, 9, 2507 (2002), and 12, 055703 (2005)., including a comparison between the measured mode structure and the predictions of a global low-beta simulation. The radial eigenmode is seen to effect the saturation level of the mode. In the Levitated Dipole Experimenthttp://psfcwww2.psfc.mit.edu/ldx/ <span class="hlt">electron</span> cyclotron resonance heating produces high beta <span class="hlt">plasmas</span> containing hot <span class="hlt">electrons</span>, and instability observations will be discussed and compared with theoretical predictions.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/22490168','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/22490168"><span>Runaway <span class="hlt">electron</span> dynamics in tokamak <span class="hlt">plasmas</span> with high impurity content</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Martín-Solís, J. R.; Loarte, A.; Lehnen, M.</p> <p>2015-09-15</p> <p>The dynamics of high energy runaway <span class="hlt">electrons</span> is analyzed for <span class="hlt">plasmas</span> with high impurity content. It is shown that modified collision terms are required in order to account for the collisions of the relativistic runaway <span class="hlt">electrons</span> with partially stripped impurity ions, including the effect of the collisions with free and bound <span class="hlt">electrons</span>, as well as the scattering by the full nuclear and the <span class="hlt">electron</span>-shielded ion charge. The effect of the impurities on the avalanche runaway growth rate is discussed. The results are applied, for illustration, to the interpretation of the runaway <span class="hlt">electron</span> behavior during disruptions, where large amounts of impurities are expected, particularly during disruption mitigation by massive gas injection. The consequences for the <span class="hlt">electron</span> synchrotron radiation losses and the resulting runaway <span class="hlt">electron</span> dynamics are also analyzed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015PhPl...22i2512M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015PhPl...22i2512M"><span>Runaway <span class="hlt">electron</span> dynamics in tokamak <span class="hlt">plasmas</span> with high impurity content</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Martín-Solís, J. R.; Loarte, A.; Lehnen, M.</p> <p>2015-09-01</p> <p>The dynamics of high energy runaway <span class="hlt">electrons</span> is analyzed for <span class="hlt">plasmas</span> with high impurity content. It is shown that modified collision terms are required in order to account for the collisions of the relativistic runaway <span class="hlt">electrons</span> with partially stripped impurity ions, including the effect of the collisions with free and bound <span class="hlt">electrons</span>, as well as the scattering by the full nuclear and the <span class="hlt">electron</span>-shielded ion charge. The effect of the impurities on the avalanche runaway growth rate is discussed. The results are applied, for illustration, to the interpretation of the runaway <span class="hlt">electron</span> behavior during disruptions, where large amounts of impurities are expected, particularly during disruption mitigation by massive gas injection. The consequences for the <span class="hlt">electron</span> synchrotron radiation losses and the resulting runaway <span class="hlt">electron</span> dynamics are also analyzed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/20192326','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/20192326"><span>Glow <span class="hlt">plasma</span> trigger for <span class="hlt">electron</span> cyclotron resonance ion sources.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Vodopianov, A V; Golubev, S V; Izotov, I V; Nikolaev, A G; Oks, E M; Savkin, K P; Yushkov, G Yu</p> <p>2010-02-01</p> <p><span class="hlt">Electron</span> cyclotron resonance ion sources (ECRISs) are particularly useful for nuclear, atomic, and high energy physics, as unique high current generators of multicharged ion beams. <span class="hlt">Plasmas</span> of gas discharges in an open magnetic trap heated by pulsed (100 micros and longer) high power (100 kW and higher) high-frequency (greater than 37.5 GHz) microwaves of gyrotrons is promising in the field of research in the development of <span class="hlt">electron</span> cyclotron resonance sources for high charge state ion beams. Reaching high ion charge states requires a decrease in gas pressure in the magnetic trap, but this method leads to increases in time, in which the microwave discharge develops. The gas breakdown and microwave discharge duration becomes greater than or equal to the microwave pulse duration when the pressure is decreased. This makes reaching the critical <span class="hlt">plasma</span> density initiate an <span class="hlt">electron</span> cyclotron resonance (ECR) discharge during pulse of microwave gyrotron radiation with gas pressure lower than a certain threshold. In order to reduce losses of microwave power, it is necessary to shorten the time of development of the ECR discharge. For fast triggering of ECR discharge under low pressure in an ECRIS, we initially propose to fill the magnetic trap with the <span class="hlt">plasmas</span> of auxiliary pulsed discharges in crossed ExB fields. The glow <span class="hlt">plasma</span> trigger of ECR based on a Penning or magnetron discharge has made it possible not only to fill the trap with <span class="hlt">plasma</span> with density of 10(12) cm(-3), required for a rapid increase in <span class="hlt">plasma</span> density and finally for ECR discharge ignition, but also to initially heat the <span class="hlt">plasma</span> <span class="hlt">electrons</span> to T(e) approximately = 20 eV.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19830052978&hterms=plasma+discharge&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3Dplasma%2Bdischarge','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19830052978&hterms=plasma+discharge&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3Dplasma%2Bdischarge"><span><span class="hlt">Electron</span> energy distribution produced by beam-<span class="hlt">plasma</span> discharge</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Anderson, H. R.; Gordeuk, J.; Jost, R. J.</p> <p>1982-01-01</p> <p>In an investigation of a beam-<span class="hlt">plasma</span> discharge (BPD), the <span class="hlt">electron</span> energy distribution of an <span class="hlt">electron</span> beam moving through a partially ionized gas is analyzed. Among other results, it is found that the occurrence of BPD heats the initially cold <span class="hlt">electron</span> beam from the accelerator. The directional intensity of <span class="hlt">electrons</span> measured outside the beam core indicates that most particles suffer a single scattering in energy and pitch angle. At low currents this result is expected as beam particles collide with the neutral atmosphere, while in BPD the majority of particles is determined to still undergo a single scattering near the original beam core. The extended energy spectra at various beam currents show two rather distinct <span class="hlt">plasma</span> populations, one centered at the initial beam energy (approximately 1500 eV) and the other at approximately 150 eV.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2000CzJPh..50..461T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2000CzJPh..50..461T"><span><span class="hlt">Sheet</span> resistance of LiNbO3 wafers processed in radio-frequency <span class="hlt">plasma</span> of hydrogen</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Turčičová, H.; Prachařová, J.; Červená, J.; Vacík, J.</p> <p>2000-03-01</p> <p>Radio-frequency discharge of 13.56MHz in hydrogen was used for processing single domain crystalline LiNbO3 wafers under an electrodeless capacitive coupling. At a pressure of 0.5 torr and RF input power of 250 W a surface layer of approx. 0.5 μm on the LiNbO3 wafers was created in which the niobate structure was strongly injured. The Li concentration dropped almost to zero at the very surface and only niobium oxides remained there. After the surface modification the wafers lost their insulating properties and became electrically conducting. The <span class="hlt">sheet</span> resistance was measured and revealed a semiconducting character. We discuss possible mechanisms of the charge carriers creation in the material during the <span class="hlt">plasma</span> processing. The nuclear method NDP (Neutron Depth Profiling) has been used for the lithium depth profiling and the four-point probe technique for the <span class="hlt">sheet</span> resistanace measurements.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013OptCo.311..317P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013OptCo.311..317P"><span>Relativistic ponderomotive effect on the propagation of rippled laser beam and the excitation of <span class="hlt">electron</span> <span class="hlt">plasma</span> wave in collisionless <span class="hlt">plasma</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Priyanka; Chauhan, Prashant; Purohit, Gunjan</p> <p>2013-01-01</p> <p>This paper presents an investigation of the propagation of rippled laser beam in a collisionless <span class="hlt">plasma</span> and its effect on and the excitation of <span class="hlt">electron</span> <span class="hlt">plasma</span> wave and particle acceleration, when relativistic and ponderomotive nonlinearities are simultaneously operative. <span class="hlt">Electron</span> <span class="hlt">plasma</span> wave (EPW) coupling with rippled laser beam arises on account of the relativistic change in the <span class="hlt">electron</span> mass and the modification of the background <span class="hlt">electron</span> density due to ponderomotive nonlinearity. When the <span class="hlt">electron</span> <span class="hlt">plasma</span> wave gets coupled to the rippled laser beam, a large fraction of the pump energy gets transferred to EPW and this excited EPW can accelerate the <span class="hlt">electrons</span>. Analytical expressions for the growth rate of the laser spike in <span class="hlt">plasma</span>, beam width of the rippled laser beam and excited <span class="hlt">electron</span> <span class="hlt">plasma</span> wave have been obtained using paraxial ray approximation. These coupled equations are solved analytically and numerically to study the growth of laser spike in <span class="hlt">plasma</span> and its effect on the self focusing of rippled laser beam in <span class="hlt">plasma</span>, amplitude of the excited <span class="hlt">electron</span> <span class="hlt">plasma</span> wave and particle acceleration. The result shows that the effect of including ponderomotive nonlinearity significantly affects the growth of laser spike in <span class="hlt">plasma</span>, excitation of <span class="hlt">electron</span> <span class="hlt">plasma</span> wave as well as the number of energetic <span class="hlt">electrons</span> in particle acceleration process. The results are presented for typical laser <span class="hlt">plasma</span> parameters.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017PlST...19d5002G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017PlST...19d5002G"><span>Linear tearing modes in an <span class="hlt">electron</span>-positron <span class="hlt">plasma</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Guiliang, SONG; Huishan, CAI</p> <p>2017-04-01</p> <p>The general dispersion of tearing modes due to the effects of <span class="hlt">electron</span> inertia and resistivity in pair <span class="hlt">plasmas</span> is derived analytically, and is discussed in two cases: \\bigtriangleup \\prime \\gg 1 and \\bigtriangleup \\prime \\ll 1, where {{Δ }}\\prime is the instability criterion of the tearing mode. It is found that the conditions under which either resistivity or <span class="hlt">electron</span> inertia dominates depend strongly on the limit of {{Δ }}\\prime considered.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/22408130','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/22408130"><span>Beltrami–Bernoulli equilibria in <span class="hlt">plasmas</span> with degenerate <span class="hlt">electrons</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Berezhiani, V. I.; Shatashvili, N. L.; Mahajan, S. M.</p> <p>2015-02-15</p> <p>A new class of Double Beltrami–Bernoulli equilibria, sustained by <span class="hlt">electron</span> degeneracy pressure, is investigated. It is shown that due to <span class="hlt">electron</span> degeneracy, a nontrivial Beltrami–Bernoulli equilibrium state is possible even for a zero temperature <span class="hlt">plasma</span>. These states are, conceptually, studied to show the existence of new energy transformation pathways converting, for instance, the degeneracy energy into fluid kinetic energy. Such states may be of relevance to compact astrophysical objects like white dwarfs, neutron stars, etc.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016APS..DPPC10117G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016APS..DPPC10117G"><span>Runaway <span class="hlt">electrons</span> and mitigation studies in MST tokamak <span class="hlt">plasmas</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Goetz, J. A.; Chapman, B. E.; Almagri, A. F.; Cornille, B. S.; Dubois, A.; McCollam, K. J.; Munaretto, S.; Sovinec, C. R.</p> <p>2016-10-01</p> <p>Studies of runaway <span class="hlt">electrons</span> generated in low-density MST tokamak <span class="hlt">plasmas</span> are being undertaken. The <span class="hlt">plasmas</span> have Bt <= 0.14 T, Ip <= 50 kA, q (a) = 2.2 , and an <span class="hlt">electron</span> density and temperature of about 5 ×1017m-3 and 150 eV. Runaway <span class="hlt">electrons</span> are detected via x-ray bremsstrahlung emission. The density and electric field thresholds for production and suppression have been previously explored with variations in gas puffing for density control. Runaway <span class="hlt">electrons</span> are now being probed with resonant magnetic perturbations (RMP's). An m = 3 RMP strongly suppresses the runaway <span class="hlt">electrons</span> and initial NIMROD modeling shows that this may be due to degradation of flux surfaces. The RMP is produced by a poloidal array of 32 saddle coils at the narrow vertical insulated cut in MST's thick conducting shell, with each RMP having a single m but a broad n spectrum. While a sufficiently strong m = 3 RMP suppresses the runaway <span class="hlt">electrons</span>, an RMP with m = 1 and comparable amplitude has little effect. The impact of the RMP's on the magnetic topology of these <span class="hlt">plasmas</span> is being studied with the nonlinear MHD code NIMROD. With an m = 3 RMP, stochasticity is introduced in the outer third of the <span class="hlt">plasma</span> but no such flux surface degradation is observed with an m = 1 RMP. NIMROD also predicts regularly occurring MHD activity similar to that observed in the experiment. These studies have also been done in q (a) = 2.7 <span class="hlt">plasmas</span> and analysis and modeling is ongoing. This work supported by USDoE.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2008JGRA..113.9318P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2008JGRA..113.9318P"><span>Equatorial <span class="hlt">plasma</span> bubbles with enhanced ion and <span class="hlt">electron</span> temperatures</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Park, Jaeheung; Min, Kyoung Wook; Kim, Vitaly P.; Kil, Hyosub; Su, Shin-Yi; Chao, Chi Kuang; Lee, Jae-Jin</p> <p>2008-09-01</p> <p>While the ion and <span class="hlt">electron</span> temperatures inside equatorial <span class="hlt">plasma</span> bubbles (EPBs) are normally lower than those in an ambient <span class="hlt">plasma</span>, bubbles with enhanced temperatures (BETs) are found occasionally in the topside ionosphere. Here we report the characteristics of BETs identified from observations of the first Republic of China Satellite (ROCSAT-1), the first Korea Multi-purpose Satellite (KOMPSAT-1), and the Defense Meteorological Satellite Program (DMSP) F15 during the solar maximum period between 2000 and 2001. The oxygen ion fraction inside the BETs, which was no lower than that of the ambient ionosphere, was similar to the case of ordinary low-temperature EPBs. These observations indicate that the BETs and low-temperature EPBs detected on the topside were produced by the upward drift of low-density <span class="hlt">plasma</span> from lower altitudes. The feature that distinguishes BETs from normal EPBs is the occurrence of an unusually fast poleward field-aligned <span class="hlt">plasma</span> flow relative to the ambient <span class="hlt">plasma</span>. The BETs occurred preferentially around geomagnetic latitudes of 10° in the summer hemisphere, where the ambient ion and <span class="hlt">electron</span> temperatures are lower than those in the conjugate winter hemisphere. The occurrence of BETs did not show any notable dependence on geomagnetic activities. The characteristics of the BETs suggest that the BETs were produced by adiabatic <span class="hlt">plasma</span> heating associated with a fast poleward oxygen ion transport along magnetic flux tubes.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20010055260','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20010055260"><span>Low Energy <span class="hlt">Electrons</span> in the Mars <span class="hlt">Plasma</span> Environment</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Link, Richard</p> <p>2001-01-01</p> <p>The ionosphere of Mars is rather poorly understood. The only direct measurements were performed by the Viking 1 and 2 landers in 1976, both of which carried a Retarding Potential Analyzer. The RPA was designed to measure ion properties during the descent, although <span class="hlt">electron</span> fluxes were estimated from changes in the ion currents. Using these derived low-energy <span class="hlt">electron</span> fluxes, Mantas and Hanson studied the photoelectron and the solar wind <span class="hlt">electron</span> interactions with the atmosphere and ionosphere of Mars. Unanswered questions remain regarding the origin of the low-energy <span class="hlt">electron</span> fluxes in the vicinity of the Mars <span class="hlt">plasma</span> boundary. Crider, in an analysis of Mars Global Surveyor Magnetometer/<span class="hlt">Electron</span> Reflectometer measurements, has attributed the formation of the magnetic pile-up boundary to <span class="hlt">electron</span> impact ionization of exospheric neutral species by solar wind <span class="hlt">electrons</span>. However, the role of photoelectrons escaping from the lower ionosphere was not determined. In the proposed work, we will examine the role of solar wind and ionospheric photoelectrons in producing ionization in the upper ionosphere of Mars. Low-energy (< 4 keV) <span class="hlt">electrons</span> will be modeled using the two-stream <span class="hlt">electron</span> transport code of Link. The code models both external (solar wind) and internal (photoelectron) sources of ionization, and accounts for Auger <span class="hlt">electron</span> production. The code will be used to analyze Mars Global Surveyor measurements of solar wind and photoelectrons down to altitudes below 200 km in the Mars ionosphere, in order to determine the relative roles of solar wind and escaping photoelectrons in maintaining <span class="hlt">plasma</span> densities in the region of the Mars <span class="hlt">plasma</span> boundary.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li class="active"><span>22</span></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_22 --> <div id="page_23" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li class="active"><span>23</span></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li><a href="#" onclick='return showDiv("page_25");'>25</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="441"> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19850036959&hterms=Plasma+doppler&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3DPlasma%2Bdoppler','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19850036959&hterms=Plasma+doppler&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3DPlasma%2Bdoppler"><span><span class="hlt">Electron</span> <span class="hlt">plasma</span> waves upstream of the earth's bow shock</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Lacombe, C.; Mangeney, A.; Harvey, C. C.; Scudder, J. D.</p> <p>1985-01-01</p> <p>Electrostatic waves are observed around the <span class="hlt">plasma</span> frequency fpe in the <span class="hlt">electron</span> foreshock, together with <span class="hlt">electrons</span> backstreaming from the bow shock. Using data from the sounder aboard ISEE 1, it is shown that this noise, previously understood as narrow band Langmuir waves more or less widened by Doppler shift or nonlinear effects, is in fact composed of two distinct parts: one is a narrow band noise, emitted just above fpe, and observed at the upstream boundary of the <span class="hlt">electron</span> foreshock. This component has been interpreted as Langmuir waves emitted by a beam-<span class="hlt">plasma</span> instability. It is suggested that it is of sufficiently large amplitude and monochromatic enough to trap resonant <span class="hlt">electrons</span>. The other is a broad band noise, more impulsive than the narrow band noise, observed well above and/or well below fpe, deeper in the <span class="hlt">electron</span> foreshock. The broad band noise has an average spectrum with a typical bi-exponential shape; its peak frequency is not exactly equal to fpe and depends on the Deybe length. This peak frequency also depends on the velocity for which the <span class="hlt">electron</span> distribution has maximum skew. An experimental determination of the dispersion relation of the broad band noise shows that this noise, as well as the narrow band noise, may be due to the instability of a hot beam in a <span class="hlt">plasma</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014PhRvC..89a5802K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014PhRvC..89a5802K"><span>Strong <span class="hlt">plasma</span> screening in thermonuclear reactions: <span class="hlt">Electron</span> drop model</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kravchuk, P. A.; Yakovlev, D. G.</p> <p>2014-01-01</p> <p>We analyze enhancement of thermonuclear fusion reactions due to strong <span class="hlt">plasma</span> screening in dense matter using a simple <span class="hlt">electron</span> drop model. In the model we assume fusion in a potential that is screened by an effective <span class="hlt">electron</span> cloud around colliding nuclei (extended Salpeter ion-sphere model). We calculate the mean-field screened Coulomb potentials for atomic nuclei with equal and nonequal charges, appropriate astrophysical S factors, and enhancement factors of reaction rates. As a byproduct, we study the analytic behavior of the screening potential at small separations between the reactants. In this model, astrophysical S factors depend not only on nuclear physics but on <span class="hlt">plasma</span> screening as well. The enhancement factors are in good agreement with calculations by other methods. This allows us to formulate a combined, pure analytic model of strong <span class="hlt">plasma</span> screening in thermonuclear reactions. The results can be useful for simulating nuclear burning in white dwarfs and neutron stars.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/21255213','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/21255213"><span>Magnetically Controlled Optical <span class="hlt">Plasma</span> Waveguide for <span class="hlt">Electron</span> Acceleration</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Pollock, B. B.; Davis, P.; Divol, L.; Glenzer, S. H.; Palastro, J. P.; Price, D.; Froula, D. H.; Tynan, G. R.</p> <p>2009-01-22</p> <p>In order to produce multi-Gev <span class="hlt">electrons</span> from Laser Wakefield Accelerators, we present a technique to guide high power laser beams through underdense <span class="hlt">plasma</span>. Experimental results from the Jupiter Laser Facility at the Lawrence Livermore National Laboratory that show density channels with minimum <span class="hlt">plasma</span> densities below 5x10{sup 17} cm{sup -3} are presented. These results are obtained using an external magnetic field (<5 T) to limit the radial heat flux from a pre-forming laser beam. The resulting increased <span class="hlt">plasma</span> pressure gradient produces a parabolic density gradient which is tunable by changing the external magnetic field strength. These results are compared with 1-D hydrodynamic simulations, while quasi-static kinetic simulations show that for these channel conditions 90% of the energy in a 150 TW short pulse beam is guided over 5 cm and predict <span class="hlt">electron</span> energy gains of 3 GeV.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/21537277','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/21537277"><span>Langmuir rogue waves in <span class="hlt">electron</span>-positron <span class="hlt">plasmas</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Moslem, W. M.</p> <p>2011-03-15</p> <p>Progress in understanding the nonlinear Langmuir rogue waves which accompany collisionless <span class="hlt">electron</span>-positron (e-p) <span class="hlt">plasmas</span> is presented. The nonlinearity of the system results from the nonlinear coupling between small, but finite, amplitude Langmuir waves and quasistationary density perturbations in an e-p <span class="hlt">plasma</span>. The nonlinear Schroedinger equation is derived for the Langmuir waves' electric field envelope, accounting for small, but finite, amplitude quasistationary <span class="hlt">plasma</span> slow motion describing the Langmuir waves' ponderomotive force. Numerical calculations reveal that the rogue structures strongly depend on the <span class="hlt">electron</span>/positron density and temperature, as well as the group velocity of the envelope wave. The present study might be helpful to understand the excitation of nonlinear rogue pulses in astrophysical environments, such as in active galactic nuclei, in pulsar magnetospheres, in neutron stars, etc.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19770032066&hterms=1055&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D70%26Ntt%3D%2526%25231055','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19770032066&hterms=1055&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D70%26Ntt%3D%2526%25231055"><span><span class="hlt">Electron</span> impact excitation coefficients for laboratory and astrophysical <span class="hlt">plasmas</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Davis, J.; Kepple, P. C.; Blaha, M.</p> <p>1976-01-01</p> <p><span class="hlt">Electron</span> impact excitation rate coefficients have been obtained for a number of transitions in highly ionized ions of interest to astrophysical and laboratory <span class="hlt">plasmas</span>. The calculations were done using the method of distorted waves. Results are presented for various transitions in highly ionized Ne, Na, Al, Si, A, Ca, Ni and Fe.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016SPJCE..11...93L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016SPJCE..11...93L"><span>Recycling of the <span class="hlt">Electronic</span> Waste Applying the <span class="hlt">Plasma</span> Reactor Technology</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Lázár, Marián; Jasminská, Natália; Čarnogurská, Mária; Dobáková, Romana</p> <p>2016-12-01</p> <p>The following paper discusses a high-temperature gasification process and melting of <span class="hlt">electronic</span> components and computer equipment using <span class="hlt">plasma</span> reactor technology. It analyses the marginal conditions of batch processing, as well as the formation of solid products which result from the procedure of waste processing. Attention is also paid to the impact of the emerging products on the environment.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/1122866','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/1122866"><span>Experimental Studies of Self Organization with <span class="hlt">Electron</span> <span class="hlt">Plasmas</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Matthaeus, William H.</p> <p>2011-04-11</p> <p>During the period of this grant we had a very active research effort in our group on the topic of 2D <span class="hlt">electron</span> <span class="hlt">plasmas</span>, relaxation, 2D Navier Stokes turbulence, and related issues. The project also motivated other studies we carried out such as a study of 2D turbulence with two-species vorticity.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/24929924','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/24929924"><span>Analysis of <span class="hlt">electron</span> beam damage of exfoliated MoS₂ <span class="hlt">sheets</span> and quantitative HAADF-STEM imaging.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Garcia, Alejandra; Raya, Andres M; Mariscal, Marcelo M; Esparza, Rodrigo; Herrera, Miriam; Molina, Sergio I; Scavello, Giovanni; Galindo, Pedro L; Jose-Yacaman, Miguel; Ponce, Arturo</p> <p>2014-11-01</p> <p>In this work we examined MoS₂ <span class="hlt">sheets</span> by aberration-corrected scanning transmission <span class="hlt">electron</span> microscopy (STEM) at three different energies: 80, 120 and 200 kV. Structural damage of the MoS₂ <span class="hlt">sheets</span> has been controlled at 80 kV according a theoretical calculation based on the inelastic scattering of the <span class="hlt">electrons</span> involved in the interaction <span class="hlt">electron</span>-matter. The threshold energy for the MoS₂ material has been found and experimentally verified in the microscope. At energies higher than the energy threshold we show surface and edge defects produced by the <span class="hlt">electron</span> beam irradiation. Quantitative analysis at atomic level in the images obtained at 80 kV has been performed using the experimental images and via STEM simulations using SICSTEM software to determine the exact number of MoS2₂ layers.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4169717','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4169717"><span>Analysis of <span class="hlt">electron</span> beam damage of exfoliated MoS2 <span class="hlt">sheets</span> and quantitative HAADF-STEM imaging</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Garcia, A.; Raya, A.M.; Mariscal, M.M.; Esparza, R.; Herrera, M.; Molina, S.I.; Scavello, G.; Galindo, P.L.; Jose-Yacaman, M.; Ponce, A.</p> <p>2014-01-01</p> <p>In this work we examined MoS2 <span class="hlt">sheets</span> by aberration-corrected scanning transmission <span class="hlt">electron</span> microscopy (STEM) at three different energies: 80, 120 and 200 kV. Structural damage of the MoS2 <span class="hlt">sheets</span> has been controlled at 80 kV according a theoretical calculation based on the inelastic scattering of the <span class="hlt">electrons</span> involved in the interaction <span class="hlt">electron</span>-matter. The threshold energy for the MoS2 material has been found and experimentally verified in the microscope. At energies higher than the energy threshold we show surface and edge defects produced by the <span class="hlt">electron</span> beam irradiation. Quantitative analysis at atomic level in the images obtained at 80 kV has been performed using the experimental images and via STEM simulations using SICSTEM software to determine the exact number of MoS2 layers. PMID:24929924</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017PhPl...24b2116E','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017PhPl...24b2116E"><span>Langmuir oscillations in a nonthermal nonextensive <span class="hlt">electron</span>-positron <span class="hlt">plasma</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>El-Taibany, W. F.; Zedan, N. A.</p> <p>2017-02-01</p> <p>The high-frequency Langmuir-type oscillations in a pure pair <span class="hlt">plasma</span> are studied using Vlasov-Poisson's equations in the presence of hybrid nonthermal nonextensive distributed species. The characteristics of the Langmuir oscillations, Landau damping, and growing unstable modes in a nonthermal nonextensive <span class="hlt">electron</span>-positron (EP) <span class="hlt">plasma</span> are remarkably modified. It is found that the phase velocity of the Langmuir waves increases by decreasing (increasing) the value of nonextensive (nonthermal) parameter, q ( α). In particular, depending on the degree of nonthermality and nonextensivity, both damping and growing oscillations are predicted in the proposed EP <span class="hlt">plasma</span>. It is seen that the Langmuir waves suffer from Landau damping in two different q regions. Furthermore, the mechanism that leads to unstable modes is established in the context of the nonthermal nonextensive formalism, yet the damping mechanism is the same developed by Landau. The present study is useful in the regions where such mixed distributions in space or laboratory <span class="hlt">plasmas</span> exist.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2007APS..MARH21013M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2007APS..MARH21013M"><span>Accelerating self consistent field convergence by rubber <span class="hlt">sheeting</span> of initial <span class="hlt">electronic</span> wave functions.</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Matthews, G. Eric; Holzwarth, N. A. W.; Martin, George; Keeling, Briana; Agopsowicz, Douglas</p> <p>2007-03-01</p> <p>We develop an algorithm for generating better initial <span class="hlt">electronic</span> wave function estimates for density functional theory calculations following atomic movement. First principles molecular dynamics and atomic relaxation calculations involve successive movements of atoms followed by self consistent field (SCF) solutions for <span class="hlt">electronic</span> wave functions. The SCF solutions converge most rapidly when starting from reasonably good estimates. Often estimates are generated directly from the wave functions of the previous atomic positions without adjustments for effects of position changes. Such estimates result in fast convergence to the correct wave function for small atomic movements, but for larger movements, convergence may be much slower. We present a method for improving the estimates of the new wave functions by using information from the movement of the atoms. Our algorithm is based on the ``rubber-<span class="hlt">sheeting</span>'' method used in overlaying satellite imagery on geographic maps. A warping function is calculated that stretches and shrinks different regions of the wave function so that regions near nuclei are dragged along with the atoms. These estimates yield faster convergence for cases studied thus far.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19950047162&hterms=perpendicular+magnetic+anisotropy&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3Dperpendicular%2Bmagnetic%2Banisotropy','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19950047162&hterms=perpendicular+magnetic+anisotropy&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3Dperpendicular%2Bmagnetic%2Banisotropy"><span>A study of weak anisotropy in <span class="hlt">electron</span> pressure in the tail current <span class="hlt">sheet</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Lee, D.-Y.; Voigt, G.-H.</p> <p>1995-01-01</p> <p>We adopt a magnetotail model with stretched field lines where ion motions are generally nonadiabatic and where it is assumed that the pressure anisotropy resides only in the <span class="hlt">electron</span> pressure tensor. We show that the magnetic field lines with p(perpendicular) greater than p(parallel) are less stretched than the corresponding field lines in the isotropic model. For p(parallel) greater than p(perpendicular), the magnetic field lines become more and more stretched as the anisotropy approaches the marginal firehose limit, p(parallel) = p(perpendicular) + B(exp 2)/mu(sub 0). We also show that the tail current density is highly enhanced at the firehose limit, a situation that might be subject to a microscopic instability. However, we emphasize that the enhancement in the current density is notable only near the center of the tail current <span class="hlt">sheet</span> (z = 0). Thus it remains unclear whether any microscopic instability can significantly alter the global magnetic field configuration of the tail. By comparing the radius of the field-line curvature at z = 0 with the particle's gyroradius, we suspect that even the conventional adiabatic description of <span class="hlt">electrons</span> may become questionable very close to the marginal firehose limit.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19870010644','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19870010644"><span><span class="hlt">Plasma</span> heating, <span class="hlt">plasma</span> flow and wave production around an <span class="hlt">electron</span> beam injected into the ionosphere</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Winckler, J. R.; Erickson, K. N.</p> <p>1986-01-01</p> <p>A brief historical summary of the Minnesota ECHO series and other relevant <span class="hlt">electron</span> beam experiments is given. The primary purpose of the ECHO experiments is the use of conjugate echoes as probes of the magnetosphere, but beam-<span class="hlt">plasma</span> and wave studies were also made. The measurement of quasi-dc electric fields and ion streaming during the ECHO 6 experiment has given a pattern for the <span class="hlt">plasma</span> flow in the hot <span class="hlt">plasma</span> region extending to 60m radius about the ECHO 6 <span class="hlt">electron</span> beam. The sheath and potential well caused by ion orbits is discussed with the aid of a model which fits the observations. ELF wave production in the <span class="hlt">plasma</span> sheath around the beam is briefly discussed. The new ECHO 7 mission to be launched from the Poker Flat range in November 1987 is described.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19850029363&hterms=technologie&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3Dtechnologie','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19850029363&hterms=technologie&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3Dtechnologie"><span>Simultaneous observation of the <span class="hlt">plasma</span> <span class="hlt">sheet</span> in the near earth and distant magnetotail - ISEE-1 and ISEE-3</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Scholer, M.; Hovestadt, D.; Klecker, B.; Baumjohann, W.; Gloeckler, G.; Ipavich, F. M.; Baker, D. N.; Zwickl, R. D.; Tsurutani, B. T.</p> <p>1984-01-01</p> <p>Particle data have been acquired by the 1981-025 and 1982-019 spacecraft at geosynchronous orbit, as well as ISEE-1 in the near earth geomagnetic tail, and ISEE-3 in the distant geomagnetic tail. These observations are supplemented by ground-based magnetograms from near local midnight stations. Attention is given to a substorm recovery phase, and to observations of ion beams at the <span class="hlt">plasma</span> <span class="hlt">sheet</span> boundary in the near earth and distant tail, respectively, which are found to flow in opposite directions.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/22496223','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/22496223"><span><span class="hlt">Electron</span> beam generated whistler emissions in a laboratory <span class="hlt">plasma</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Van Compernolle, B. Pribyl, P.; Gekelman, W.; An, X.; Bortnik, J.; Thorne, R. M.</p> <p>2015-12-10</p> <p>Naturally occurring whistler mode emissions in the magnetosphere, are important since they are responsible for the acceleration of outer radiation belt <span class="hlt">electrons</span> to relativistic energies and also for the scattering loss of these <span class="hlt">electrons</span> into the atmosphere. Recently, we reported on the first laboratory experiment where whistler waves exhibiting fast frequency chirping have been artificially produced [1]. A beam of energetic <span class="hlt">electrons</span> is launched into a cold <span class="hlt">plasma</span> and excites both chirping whistler waves and broadband waves. Here we extend our previous analysis by comparing the properties of the broadband waves with linear theory.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19940033865&hterms=screened+hydrogenic+model&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3Dscreened%2Bhydrogenic%2Bmodel','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19940033865&hterms=screened+hydrogenic+model&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3Dscreened%2Bhydrogenic%2Bmodel"><span><span class="hlt">Plasma</span>-screening effects on the <span class="hlt">electron</span>-impact excitation of hydrogenic ions in dense <span class="hlt">plasmas</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Jung, Young-Dae</p> <p>1993-01-01</p> <p><span class="hlt">Plasma</span>-screening effects are investigated on <span class="hlt">electron</span>-impact excitation of hydrogenic ions in dense <span class="hlt">plasmas</span>. Scaled cross sections Z(exp 4) sigma for 1s yields 2s and 1s yields 2p are obtained for a Debye-Hueckel model of the screened Coulomb interaction. Ground and excited bound wave functions are modified in the screened Coulomb potential (Debye-Hueckel model) using the Ritz variation method. The resulting atomic wave functions and their eigenenergies agree well with the numerical and high-order perturbation theory calculations for the interesting domain of the Debye length not less than 10. The Born approximation is used to describe the continuum states of the projectile <span class="hlt">electron</span>. <span class="hlt">Plasma</span> screening effects on the atomic <span class="hlt">electrons</span> cannot be neglected in the high-density cases. Including these effects, the cross sections are appreciably increased for 1s yields 2s transitions and decreased for 1s yields 2p transitions.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/16605459','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/16605459"><span>Effects of target <span class="hlt">plasma</span> <span class="hlt">electron-electron</span> collisions on correlated motion of fragmented protons.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Barriga-Carrasco, Manuel D</p> <p>2006-02-01</p> <p>The objective of the present work is to examined the effects of <span class="hlt">plasma</span> target <span class="hlt">electron-electron</span> collisions on H2 + protons traversing it. Specifically, the target is deuterium in a <span class="hlt">plasma</span> state with temperature Te=10 eV and density n=10(23) cm(-3), and proton velocities are vp=vth, vp=2vth, and vp=3vth, where vth is the <span class="hlt">electron</span> thermal velocity of the target <span class="hlt">plasma</span>. Proton interactions with <span class="hlt">plasma</span> <span class="hlt">electrons</span> are treated by means of the dielectric formalism. The interactions among close protons through <span class="hlt">plasma</span> <span class="hlt">electronic</span> medium are called vicinage forces. It is checked that these forces always screen the Coulomb explosions of the two fragmented protons from the same H2 + ion decreasing their relative distance. They also align the interproton vector along the motion direction, and increase the energy loss of the two protons at early dwell times while for longer times the energy loss tends to the value of two isolated protons. Nevertheless, vicinage forces and effects are modified by the target <span class="hlt">electron</span> collisions. These collisions enhance the calculated self-stopping and vicinage forces over the collisionless results. Regarding proton correlated motion, when these collisions are included, the interproton vector along the motion direction overaligns at slower proton velocities (vp=vth) and misaligns for faster ones (vp=2vth, vp=3vth). They also contribute to a great extend to increase the energy loss of the fragmented H2 + ion. This later effect is more significant in reducing projectile velocity.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015PhyS...90f8021G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015PhyS...90f8021G"><span>Langmuir solitons in a <span class="hlt">plasma</span> with inhomogeneous <span class="hlt">electron</span> temperature</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Gromov, Evgeny M.; Malomed, Boris A.</p> <p>2015-06-01</p> <p>Dynamics of Langmuir solitons is considered in <span class="hlt">plasmas</span> with spatially inhomogeneous <span class="hlt">electron</span> temperature. An underlying Zakharov-type system of two unidirectional equations for the Langmuir and ion-sound fields is reduced to an inhomogeneous nonlinear Schrödinger equation with spatial variation of the second-order dispersion and self-phase modulation coefficients, induced by a spatially inhomogeneous profile of the <span class="hlt">electron</span> temperature. Analytical trajectories of motion of a soliton in the <span class="hlt">plasma</span> with an <span class="hlt">electron</span>-temperature hole, barrier, or cavity between two barriers are found, using the method of integral moments. The possibility of the soliton to pass a high-temperature barrier is shown too. Analytical results are well corroborated by numerical simulations.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016JPlPh..82b9005M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016JPlPh..82b9005M"><span>Relativistic thermal <span class="hlt">electron</span> scale instabilities in sheared flow <span class="hlt">plasma</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Miller, Evan D.; Rogers, Barrett N.</p> <p>2016-04-01</p> <p>> The linear dispersion relation obeyed by finite-temperature, non-magnetized, relativistic two-fluid <span class="hlt">plasmas</span> is presented, in the special case of a discontinuous bulk velocity profile and parallel wave vectors. It is found that such flows become universally unstable at the collisionless <span class="hlt">electron</span> skin-depth scale. Further analyses are performed in the limits of either free-streaming ions or ultra-hot <span class="hlt">plasmas</span>. In these limits, the system is highly unstable in the parameter regimes associated with either the <span class="hlt">electron</span> scale Kelvin-Helmholtz instability (ESKHI) or the relativistic <span class="hlt">electron</span> scale sheared flow instability (RESI) recently highlighted by Gruzinov. Coupling between these modes provides further instability throughout the remaining parameter space, provided both shear flow and temperature are finite. An explicit parameter space bound on the highly unstable region is found.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017PPCF...59a4011B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017PPCF...59a4011B"><span>Microscopic theory of <span class="hlt">electron</span> absorption by <span class="hlt">plasma</span>-facing surfaces</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Bronold, F. X.; Fehske, H.</p> <p>2017-01-01</p> <p>We describe a method for calculating the probability with which the wall of a <span class="hlt">plasma</span> absorbs an <span class="hlt">electron</span> at low energy. The method, based on an invariant embedding principle, expresses the <span class="hlt">electron</span> absorption probability as the probability for transmission through the wall’s long-range surface potential times the probability to stay inside the wall despite of internal backscattering. To illustrate the approach we apply it to a SiO2 surface. Besides emission of optical phonons inside the wall we take elastic scattering at imperfections of the <span class="hlt">plasma</span>-wall interface into account and obtain absorption probabilities significantly less than unity in accordance with available <span class="hlt">electron</span>-beam scattering data but in disagreement with the widely used perfect absorber model.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li class="active"><span>23</span></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li><a href="#" onclick='return showDiv("page_25");'>25</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_23 --> <div id="page_24" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li class="active"><span>24</span></li> <li><a href="#" onclick='return showDiv("page_25");'>25</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="461"> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/21194989','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/21194989"><span>Feedback control of <span class="hlt">plasma</span> <span class="hlt">electron</span> density and ion energy in an inductively coupled <span class="hlt">plasma</span> etcher</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Lin Chaung; Leou, K.-C.; Huang, H.-M.; Hsieh, C.-H.</p> <p>2009-01-15</p> <p>Here the authors report the development of a fuzzy logic based feedback control of the <span class="hlt">plasma</span> <span class="hlt">electron</span> density and ion energy for high density <span class="hlt">plasma</span> etch process. The <span class="hlt">plasma</span> <span class="hlt">electron</span> density was measured using their recently developed transmission line microstrip microwave interferometer mounted on the chamber wall, and the rf voltage was measured by a commercial impedance meter connected to the wafer stage. The actuators were two 13.56 MHz rf power generators which provided the inductively coupled <span class="hlt">plasma</span> power and bias power, respectively. The control system adopted the fuzzy logic control algorithm to reduce frequent actuator action resulting from measurement noise. The experimental results show that the first wafer effect can be eliminated using closed-loop control for both poly-Si and HfO{sub 2} etching. In particular, for the HfO2 etch, the controlled variables in this work were much more effective than the previous one where ion current was controlled, instead of the <span class="hlt">electron</span> density. However, the pressure disturbance effect cannot be reduced using <span class="hlt">plasma</span> <span class="hlt">electron</span> density feedback.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015PhRvL.115r4802V','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015PhRvL.115r4802V"><span>Active <span class="hlt">Plasma</span> Lensing for Relativistic Laser-<span class="hlt">Plasma</span>-Accelerated <span class="hlt">Electron</span> Beams</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>van Tilborg, J.; Steinke, S.; Geddes, C. G. R.; Matlis, N. H.; Shaw, B. H.; Gonsalves, A. J.; Huijts, J. V.; Nakamura, K.; Daniels, J.; Schroeder, C. B.; Benedetti, C.; Esarey, E.; Bulanov, S. S.; Bobrova, N. A.; Sasorov, P. V.; Leemans, W. P.</p> <p>2015-10-01</p> <p>Compact, tunable, radially symmetric focusing of <span class="hlt">electrons</span> is critical to laser-<span class="hlt">plasma</span> accelerator (LPA) applications. Experiments are presented demonstrating the use of a discharge-capillary active <span class="hlt">plasma</span> lens to focus 100-MeV-level LPA beams. The lens can provide tunable field gradients in excess of 3000 T /m , enabling cm-scale focal lengths for GeV-level beam energies and allowing LPA-based <span class="hlt">electron</span> beams and light sources to maintain their compact footprint. For a range of lens strengths, excellent agreement with simulation was obtained.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26565471','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26565471"><span>Active <span class="hlt">Plasma</span> Lensing for Relativistic Laser-<span class="hlt">Plasma</span>-Accelerated <span class="hlt">Electron</span> Beams.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>van Tilborg, J; Steinke, S; Geddes, C G R; Matlis, N H; Shaw, B H; Gonsalves, A J; Huijts, J V; Nakamura, K; Daniels, J; Schroeder, C B; Benedetti, C; Esarey, E; Bulanov, S S; Bobrova, N A; Sasorov, P V; Leemans, W P</p> <p>2015-10-30</p> <p>Compact, tunable, radially symmetric focusing of <span class="hlt">electrons</span> is critical to laser-<span class="hlt">plasma</span> accelerator (LPA) applications. Experiments are presented demonstrating the use of a discharge-capillary active <span class="hlt">plasma</span> lens to focus 100-MeV-level LPA beams. The lens can provide tunable field gradients in excess of 3000 T/m, enabling cm-scale focal lengths for GeV-level beam energies and allowing LPA-based <span class="hlt">electron</span> beams and light sources to maintain their compact footprint. For a range of lens strengths, excellent agreement with simulation was obtained.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19950044296&hterms=current+sheet&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D60%26Ntt%3Dcurrent%2Bsheet','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19950044296&hterms=current+sheet&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D60%26Ntt%3Dcurrent%2Bsheet"><span>Thin current <span class="hlt">sheets</span> in the deep geomagnetic tail</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Pulkkinen, T. I.; Baker, D. N.; Owen, C. J.; Gosling, J. T.; Murphy, N.</p> <p>1993-01-01</p> <p>The International Sun-Earth Explorer 3 (ISEE-3) magnetic field and <span class="hlt">plasma</span> <span class="hlt">electron</span> data from Jan - March 1983 have been searched to study thin current <span class="hlt">sheets</span> in the deep tail region. 33 events were selected where the spacecraft crossed through the current <span class="hlt">sheet</span> from lobe to lobe within 15 minutes. The average thickness of the observed current <span class="hlt">sheets</span> was 2.45 R(sub E), and in 24 cases the current <span class="hlt">sheet</span> was thinner than 3.0 R(sub E); 6 very thin current <span class="hlt">sheets</span> (thickness lambda less than 0.5 R(sub E) were found. The <span class="hlt">electron</span> data show that the very thin current <span class="hlt">sheets</span> are associated with considerable temperature anisotropy. On average, the <span class="hlt">electron</span> gradient current was about 17% of the total current, whereas the current arising from the <span class="hlt">electron</span> temperature anisotropy varied between 8-45% of the total current determined from the lobe field magnitude.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19860037241&hterms=pure&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D70%26Ntt%3Dpure','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19860037241&hterms=pure&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D70%26Ntt%3Dpure"><span>Thermal equilibrium of a cryogenic magnetized pure <span class="hlt">electron</span> <span class="hlt">plasma</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Dubin, D. H. E.; Oneil, T. M.</p> <p>1986-01-01</p> <p>The thermal equilibrium correlation properties of a magnetically confined pure <span class="hlt">electron</span> <span class="hlt">plasma</span> (McPEP) are related to those of a one-component <span class="hlt">plasma</span> (OCP). The N-particle spatial distribution rho sub s and the Helmholtz free energy F are evaluated for the McPEP to O(lambda sub d-squared/a-squared), where lambda sub d is the thermal de Broglie wavelength and is an interparticle spacing. The <span class="hlt">electron</span> gyromotion is allowed to be fully quantized while the guiding center motion is quasi-classical. The distribution rho sub s is shown to be identical to that of a classical OCP with a slightly modified potential. To O(lambda sub d-squared/a-squared) this modification does not affect that part of F that is caused by correlations, as long as certain requirements concerning the size of the <span class="hlt">plasma</span> are met. This theory is motivated by a current series of experiments that involve the cooling of a magnetically confined pure <span class="hlt">electron</span> <span class="hlt">plasma</span> to the cryogenic temperature range.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2002AnGeo..20..619M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2002AnGeo..20..619M"><span>ISEE-3 observations of a viscously-driven <span class="hlt">plasma</span> <span class="hlt">sheet</span>: magnetosheath mass and/or momentum transfer?</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Mist, R. T.; Owen, C. J.</p> <p>2002-05-01</p> <p>A statistical analysis of data from the ISEE-3 distant tail campaign is presented. We investigate the mechanism driving slow, tailward flows observed in the <span class="hlt">plasma</span> <span class="hlt">sheet</span>. The possibility that these slow flows are driven by mass and/or momentum transfer across the distant tail magnetopause is explored. We establish that 40% of these flows could be driven by the transfer of approximately 4% of the magnetosheath momentum flux into the magnetotail. Current understanding of the Kelvin-Helmholtz instability suggests that this figure is consistent with the amount of momentum flux transfer produced by this mechanism. We also consider the possibility that these flows are solely driven by transferring magnetosheath <span class="hlt">plasma</span> across the magnetopause. We find that there is sufficient mass observed on these field lines for this to be the sole driving mechanism for only 27% of the observed slow flows.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014AGUFMSM44A..03B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014AGUFMSM44A..03B"><span>Suprathermal <span class="hlt">Electrons</span> in the <span class="hlt">Plasma</span> Environments of Mars and Venus</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Brain, D. A.</p> <p>2014-12-01</p> <p>Suprathermal <span class="hlt">electrons</span> have been measured in situ at every planet in the solar system, as well as at many smaller solar system bodies. They are hallmarks of heating, acceleration, or non-equilibrium processes occurring in any <span class="hlt">plasma</span>, and planets are no exception. After introducing the many planetary measurements that have been made over time, this presentation will focus on a subset of <span class="hlt">electron</span> measurements from Mars and Venus made over the last decade. At Mars, suprathermal <span class="hlt">electrons</span> are used as diagnostics of auroral acceleration in small-scale crustal fields, and the magnetic topology of the crustal fields. At Venus, <span class="hlt">electron</span> energy distributions are used to map the ionosphere, revealing previously unknown asymmetries. The presentation will close with a brief discussion of prospects for future and ongoing planetary <span class="hlt">electron</span> measurements.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015PPCF...57i5006N','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015PPCF...57i5006N"><span>Kinetic modelling of runaway <span class="hlt">electron</span> avalanches in tokamak <span class="hlt">plasmas</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Nilsson, E.; Decker, J.; Peysson, Y.; Granetz, R. S.; Saint-Laurent, F.; Vlainic, M.</p> <p>2015-09-01</p> <p>Runaway <span class="hlt">electrons</span> can be generated in tokamak <span class="hlt">plasmas</span> if the accelerating force from the toroidal electric field exceeds the collisional drag force owing to Coulomb collisions with the background <span class="hlt">plasma</span>. In ITER, disruptions are expected to generate runaway <span class="hlt">electrons</span> mainly through knock-on collisions (Hender et al 2007 Nucl. Fusion 47 S128-202), where enough momentum can be transferred from existing runaways to slow <span class="hlt">electrons</span> to transport the latter beyond a critical momentum, setting off an avalanche of runaway <span class="hlt">electrons</span>. Since knock-on runaways are usually scattered off with a significant perpendicular component of the momentum with respect to the local magnetic field direction, these particles are highly magnetized. Consequently, the momentum dynamics require a full 3D kinetic description, since these <span class="hlt">electrons</span> are highly sensitive to the magnetic non-uniformity of a toroidal configuration. For this purpose, a bounce-averaged knock-on source term is derived. The generation of runaway <span class="hlt">electrons</span> from the combined effect of Dreicer mechanism and knock-on collision process is studied with the code LUKE, a solver of the 3D linearized bounce-averaged relativistic <span class="hlt">electron</span> Fokker-Planck equation (Decker and Peysson 2004 DKE: a fast numerical solver for the 3D drift kinetic equation Report EUR-CEA-FC-1736, Euratom-CEA), through the calculation of the response of the <span class="hlt">electron</span> distribution function to a constant parallel electric field. The model, which has been successfully benchmarked against the standard Dreicer runaway theory now describes the runaway generation by knock-on collisions as proposed by Rosenbluth (Rosenbluth and Putvinski 1997 Nucl. Fusion 37 1355-62). This paper shows that the avalanche effect can be important even in non-disruptive scenarios. Runaway formation through knock-on collisions is found to be strongly reduced when taking place off the magnetic axis, since trapped <span class="hlt">electrons</span> can not contribute to the runaway <span class="hlt">electron</span> population. Finally, the</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015APS..GECGT1143N','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015APS..GECGT1143N"><span>PECVD of SiOC Films Using a <span class="hlt">Sheet</span>-type Atmospheric Pressure <span class="hlt">Plasma</span> Jet</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Nakajima, Kouta; Tanaka, Kenji; Shirafuji, Tatsuru</p> <p>2015-09-01</p> <p>Packaging industries have used SiOC thin films for gas barrier coatings on the membranes for packaging foods, drug, and so on. PECVD is the most extensively employed method for preparing the SiOC films. However, PECVD is a process performed at a low pressure in general and requires expensive vacuum systems, especially in the case of large area coatings. Atmospheric pressure PECVD is a candidate to overcome this issue. If we simply apply atmospheric pressure <span class="hlt">plasma</span> to CVD processes, however, we will encounter the problem of particle formation because of the high collision frequency in the environment of atmospheric pressure. In this work, we have developed a reactor that utilizes a unique gas-flow scheme for avoiding the particle formation. We have successfully deposited SiOC films by using this reactor, in which the source material is hexamethyldisiloxane and discharge/carrier gas is He. XPS measurements on the SiOC films have revealed that the films contain relatively higher concentrations of unfavorable methyl groups that reduce gas barrier performances. However, no particulates are involved in and on the deposited films as long as characterizing the films with eye observation and with transmission <span class="hlt">electron</span> microscopy.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/22490931','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/22490931"><span>Arbitrary amplitude slow <span class="hlt">electron</span>-acoustic solitons in three-<span class="hlt">electron</span> temperature space <span class="hlt">plasmas</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Mbuli, L. N.; Maharaj, S. K.; Bharuthram, R.; Singh, S. V.; Lakhina, G. S.</p> <p>2015-06-15</p> <p>We examine the characteristics of large amplitude slow <span class="hlt">electron</span>-acoustic solitons supported in a four-component unmagnetised <span class="hlt">plasma</span> composed of cool, warm, hot <span class="hlt">electrons</span>, and cool ions. The inertia and pressure for all the species in this <span class="hlt">plasma</span> system are retained by assuming that they are adiabatic fluids. Our findings reveal that both positive and negative potential slow <span class="hlt">electron</span>-acoustic solitons are supported in the four-component <span class="hlt">plasma</span> system. The polarity switch of the slow <span class="hlt">electron</span>-acoustic solitons is determined by the number densities of the cool and warm <span class="hlt">electrons</span>. Negative potential solitons, which are limited by the cool and warm <span class="hlt">electron</span> number densities becoming unreal and the occurrence of negative potential double layers, are found for low values of the cool <span class="hlt">electron</span> density, while the positive potential solitons occurring for large values of the cool <span class="hlt">electron</span> density are only limited by positive potential double layers. Both the lower and upper Mach numbers for the slow <span class="hlt">electron</span>-acoustic solitons are computed and discussed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/21612543','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/21612543"><span>Calculation of <span class="hlt">electronic</span> transport coefficients of Ag and Au <span class="hlt">plasma</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Apfelbaum, E. M.</p> <p>2011-12-15</p> <p>The thermoelectric transport coefficients of silver and gold <span class="hlt">plasma</span> have been calculated within the relaxation-time approximation. We considered temperatures of 10-100 kK and densities of {rho} < or approx. 1 g/cm{sup 3}. The <span class="hlt">plasma</span> composition was calculated using a corresponding system of coupled mass action laws, including the atom ionization up to +4. For momentum cross sections of <span class="hlt">electron</span>-atom scattering we used the most accurate expressions available. The results of our modeling have been compared with other researchers' data whenever possible.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2006JGRA..111.1204O','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2006JGRA..111.1204O"><span>Effects of the fast <span class="hlt">plasma</span> <span class="hlt">sheet</span> flow on the geosynchronous magnetic configuration: Geotail and GOES coordinated study</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ohtani, S.; Singer, H. J.; Mukai, T.</p> <p>2006-01-01</p> <p>The present study statistically examines how (or if) the geosynchronous (GOES) magnetic field responds to fast earthward flow observed by the Geotail satellite in the <span class="hlt">plasma</span> <span class="hlt">sheet</span>. The change of the GOES H (north-south) component within 15 min of the detection of fast flows, ΔH, is used as a primary measure of the geosynchronous response. It is found that following the detection of fast flows, the geosynchronous magnetic field rarely dipolarizes, but it often becomes more stretched, which is manifested by negative ΔH. This H decrease is not accompanied by any correlated variation of the D (azimuthal) component, suggesting that the associated stretching is not an edge effect of the substorm current wedge formation, but it can be attributed to the intensification of the local tail current. No systematic dependence of ΔH on the satellite separation can be found. On the other hand, the geosynchronous magnetic field tends to dipolarize if it is already stretched significantly, although the associated changes in the H and V (radial) components are not much larger than those in events that are not preconditioned. The flow intensity does not seem to be a controlling factor, either. However, caution needs to be exercised because the present study is not able to address the azimuthal structure of the fast flow. It is concluded that in most events the fast <span class="hlt">plasma</span> flow does not reach geosynchronous orbit and that the generation of the fast <span class="hlt">plasma</span> flow in the <span class="hlt">plasma</span> <span class="hlt">sheet</span> is not sufficient for causing geosynchronous dipolarization.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015APS..GECLW1035L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015APS..GECLW1035L"><span><span class="hlt">Electron</span> heating and control of <span class="hlt">electron</span> energy distribution in hybrid <span class="hlt">plasma</span> source for the enhancement of the <span class="hlt">plasma</span> ashing processing</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Lee, Hyo-Chang; Chung, Chin-Wook</p> <p>2015-09-01</p> <p>In this study, control of the <span class="hlt">electron</span> energy distribution function (EEDF) is investigated in hybrid <span class="hlt">plasma</span> source with inductive and capacitive fields. With the addition of a small amount of antenna coil power to the capacitive discharge, low energy <span class="hlt">electrons</span> are effectively heated and the EEDF is controlled. This method is applied to the ashing process of the photoresistor (PR). It is revealed that the ashing rate of the PR is significantly increased due to O radicals produced by the controlled EEDF, even though the ion density/energy flux is not increased. The roles of the power transfer mode, the <span class="hlt">electron</span> heating, and the discharge parameters are also presented in the hybrid <span class="hlt">plasma</span> source. This work can be used to an inter-ashing method during etching process.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1981PhFl...24.1456N','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1981PhFl...24.1456N"><span>Parametric instabilities in an <span class="hlt">electron</span> beam <span class="hlt">plasma</span> system</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Nakach, R.; Cuperman, S.; Gell, Y.; Levush, B.</p> <p>1981-08-01</p> <p>The excitation of low-frequency parametric instabilities by a finite wavelength pump, in a system consisting of a warm <span class="hlt">electron</span> <span class="hlt">plasma</span> traversed by a warm <span class="hlt">electron</span> beam, is investigated in a fluid dissipationless model. The appropriate dispersion relation is derived for the three-dimensional problem in a magnetized <span class="hlt">plasma</span> with arbitrary directions for the waves, and the one-dimensional case is analyzed numerically. It is shown that when the <span class="hlt">plasma-electron</span> Debye length is larger than the beam-<span class="hlt">electron</span> Debye length, two low frequency electrostatic instabilities may exist simultaneously. For this case, their growth rates might differ by more than one order of magnitude and the effect of the pump field on the larger growth rate instability is not very significant. For the opposite case, only one instability can be excited which reduces to the parametric instability discussed by Fried et al. (1976), when the beam is switched off. Attention is given to the case corresponding to equal Debye lengths where, in addition to the previously mentioned parametric instability, a large growth rate instability can be excited, which, however, depends on the amplitude of the pump field.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017PhPl...24c3501V','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017PhPl...24c3501V"><span><span class="hlt">Electron</span>-silane scattering cross section for <span class="hlt">plasma</span> assisted processes</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Verma, Pankaj; Kaur, Jaspreet; Antony, Bobby</p> <p>2017-03-01</p> <p>Silane is an important molecule with numerous applications to natural and technological <span class="hlt">plasmas</span>. In such environments, where <span class="hlt">plasma</span> assisted processes are vital, <span class="hlt">electron</span> induced reactions play a major role in its chemistry. In view of this, <span class="hlt">electron</span> induced scattering of molecules such as silane finds significance. This article reports a comprehensive study of <span class="hlt">electron</span> impact cross sections for silane over a wide energy range. In particular, the emphasis is given in providing a complete dataset for various <span class="hlt">electron</span> scattering events possible with silane. Such dataset is the need for the <span class="hlt">plasma</span> modeling community. Moreover, literature survey shows that the cross section database for silane is fragmentary. To fill this void, we have computed the differential elastic, total, rotational excitation, and momentum transfer cross sections. Two formalisms that are reliable in their energy domain are employed to accomplish the task: the R-matrix method through QUANTEMOL-N at low incident energies and the spherical complex optical potential formalism at intermediate to high energies. Interestingly, the comparison of the present cross section exhibits a good concurrence with the previous data, wherever available.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016APS..DPPJO7010L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016APS..DPPJO7010L"><span><span class="hlt">Electron</span> <span class="hlt">plasma</span> wave filamentation in the kinetic regime</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Lushnikov, Pavel; Rose, Harvey; Silantyev, Denis</p> <p>2016-10-01</p> <p>We consider nonlinear <span class="hlt">electron</span> <span class="hlt">plasma</span> wave (EPW) dynamics in the kinetic wavenumber regime, 0.25 < kλD < 0.45 , which is typical for current high temperature laser-<span class="hlt">plasma</span> interaction experiments, where k is the EPW wavenumber and λD is the <span class="hlt">electron</span> Debye length. In this kinetic regime, EPW frequency reduction due to <span class="hlt">electron</span> trapping may dominate the ponderomotive frequency shift. Previous 3D PIC simulations showed that the trapped <span class="hlt">electron</span> EPW filamentation instability can saturate stimulated Raman backscatter by reducing the EPWs coherence but multidimensional Vlasov simulations [1] are needed to address that saturation in details. We performed nonlinear, non-equilibrium 2D Vlasov simulations to study the EPW filamentation. The initial conditions are created either by external forcing or by constructing the appropriate 1D travelling Bernstein-Greene-Kruskal (BGK) mode. Transverse perturbations of any of these initial conditions grow with time eventually producing strongly nonlinear filamentation followed by <span class="hlt">plasma</span> turbulence. We compared these simulations with the theoretical results on growth rates of the transverse instability BGK mode showing the satisfactory agreement. Supported by the New Mexico Consortium and NSF DMS-1412140.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1992PNAS...8911126S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1992PNAS...8911126S"><span>Requirement for Coenzyme Q in <span class="hlt">Plasma</span> Membrane <span class="hlt">Electron</span> Transport</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Sun, I. L.; Sun, E. E.; Crane, F. L.; Morre, D. J.; Lindgren, A.; Low, H.</p> <p>1992-12-01</p> <p>Coenzyme Q is required in the <span class="hlt">electron</span> transport system of rat hepatocyte and human erythrocyte <span class="hlt">plasma</span> membranes. Extraction of coenzyme Q from the membrane decreases NADH dehydrogenase and NADH:oxygen oxidoreductase activity. Addition of coenzyme Q to the extracted membrane restores the activity. Partial restoration of activity is also found with α-tocopherylquinone, but not with vitamin K_1. Analogs of coenzyme Q inhibit NADH dehydrogenase and oxidase activity and the inhibition is reversed by added coenzyme Q. Ferricyanide reduction by transmembrane <span class="hlt">electron</span> transport from HeLa cells is inhibited by coenzyme Q analogs and restored with added coenzyme Q10. Reduction of external ferricyanide and diferric transferrin by HeLa cells is accompanied by proton release from the cells. Inhibition of the reduction by coenzyme Q analogs also inhibits the proton release, and coenzyme Q10 restores the proton release activity. Trans-<span class="hlt">plasma</span> membrane <span class="hlt">electron</span> transport stimulates growth of serum-deficient cells, and added coenzyme Q10 increases growth of HeLa (human adenocarcinoma) and BALB/3T3 (mouse fibroblast) cells. The evidence is consistent with a function for coenzyme Q in a trans-<span class="hlt">plasma</span> membrane <span class="hlt">electron</span> transport system which influences cell growth.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19970040338&hterms=estado&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3Destado','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19970040338&hterms=estado&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3Destado"><span>Excitation of <span class="hlt">Plasma</span> Waves in Aurora by <span class="hlt">Electron</span> Beams</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>daSilva, C. E.; Vinas, A. F.; deAssis, A. S.; deAzevedo, C. A.</p> <p>1996-01-01</p> <p>In this paper, we study numerically the excitation of <span class="hlt">plasma</span> waves by <span class="hlt">electron</span> beams, in the auroral region above 2000 km of altitude. We have solved the fully kinetic dispersion relation, using numerical method and found the real frequency and the growth rate of the <span class="hlt">plasma</span> wave modes. We have examined the instability properties of low-frequency waves such as the Electromagnetic Ion Cyclotron (EMIC) wave as well as Lower-Hybrid (LH) wave in the range of high-frequency. In all cases, the source of free energy are <span class="hlt">electron</span> beams propagating parallel to the geomagnetic field. We present some features of the growth rate modes, when the cold <span class="hlt">plasma</span> parameters are changed, such as background <span class="hlt">electrons</span> and ions species (H(+) and O(+)) temperature, density or the <span class="hlt">electron</span> beam density and/or drift velocity. These results can be used in a test-particle simulation code, to investigate the ion acceleration and their implication in the auroral acceleration processes, by wave-particle interaction.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/15457253','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/15457253"><span>A laser-<span class="hlt">plasma</span> accelerator producing monoenergetic <span class="hlt">electron</span> beams.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Faure, J; Glinec, Y; Pukhov, A; Kiselev, S; Gordienko, S; Lefebvre, E; Rousseau, J-P; Burgy, F; Malka, V</p> <p>2004-09-30</p> <p>Particle accelerators are used in a wide variety of fields, ranging from medicine and biology to high-energy physics. The accelerating fields in conventional accelerators are limited to a few tens of MeV m(-1), owing to material breakdown at the walls of the structure. Thus, the production of energetic particle beams currently requires large-scale accelerators and expensive infrastructures. Laser-<span class="hlt">plasma</span> accelerators have been proposed as a next generation of compact accelerators because of the huge electric fields they can sustain (>100 GeV m(-1)). However, it has been difficult to use them efficiently for applications because they have produced poor-quality particle beams with large energy spreads, owing to a randomization of <span class="hlt">electrons</span> in phase space. Here we demonstrate that this randomization can be suppressed and that the quality of the <span class="hlt">electron</span> beams can be dramatically enhanced. Within a length of 3 mm, the laser drives a <span class="hlt">plasma</span> bubble that traps and accelerates <span class="hlt">plasma</span> <span class="hlt">electrons</span>. The resulting <span class="hlt">electron</span> beam is extremely collimated and quasi-monoenergetic, with a high charge of 0.5 nC at 170 MeV.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19840033237&hterms=High+Altitude+Plasma+Instrument&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3DHigh%2BAltitude%2BPlasma%2BInstrument','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19840033237&hterms=High+Altitude+Plasma+Instrument&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3DHigh%2BAltitude%2BPlasma%2BInstrument"><span>Polar cap <span class="hlt">electron</span> densities from DE 1 <span class="hlt">plasma</span> wave observations</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Persoon, A. M.; Gurnett, D. A.; Shawhan, S. D.</p> <p>1983-01-01</p> <p>Electric-field-spectum measurements from the <span class="hlt">plasma</span>-wave instrument on the Dynamics Explorer 1 spacecraft are used to study the local <span class="hlt">electron</span> density at high altitudes in the northern polar-cap region. The <span class="hlt">electron</span> density is determined from the upper cutoff of whistler-mode radiation at the <span class="hlt">electron</span> <span class="hlt">plasma</span> frequency. Median density values over the polar cap at L greater than 10 are found to vary from 35.2 + or - 8.5 cu cm at 2.1 earth radii to 0.99 + or - 0.51 cu cm at 4.66 earth radii. The steady-state radial-outflow model is examined for consistency with the observed density profile. A power-law fit to the radial variation of the <span class="hlt">electron</span> density yields an exponent of - 3.85 + or - 0.32, which for the radial-outflow model implies a flow velocity increasing nearly linearly with incresing radial distance. Comparison of the observed <span class="hlt">electron</span> densities with theoretical polar-wind densities yields consistent results up to 2.8 earth radii. A comparison of the observed <span class="hlt">electron</span> densities with low-altitude density profiles from the Alouette II and ISIS 1 spacecraft illustrates transitions in the slope of the profile at 1.16 earth radii and between 1.55 and 2.0 earth radii. The changes in the density profile suggest that changes occur in the basic radial-transport processes at these altitudes.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li class="active"><span>24</span></li> <li><a href="#" onclick='return showDiv("page_25");'>25</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_24 --> <div id="page_25" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li class="active"><span>25</span></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="481"> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/22403284','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/22403284"><span>Collimated fast <span class="hlt">electron</span> beam generation in critical density <span class="hlt">plasma</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Iwawaki, T. Habara, H.; Morita, K.; Tanaka, K. A.; Baton, S.; Fuchs, J.; Chen, S.; Nakatsutsumi, M.; Rousseaux, C.; Filippi, F.; Nazarov, W.</p> <p>2014-11-15</p> <p>Significantly collimated fast <span class="hlt">electron</span> beam with a divergence angle 10° (FWHM) is observed when an ultra-intense laser pulse (I = 10{sup 14 }W/cm{sup 2}, 300 fs) irradiates a uniform critical density <span class="hlt">plasma</span>. The uniform <span class="hlt">plasma</span> is created through the ionization of an ultra-low density (5 mg/c.c.) plastic foam by X-ray burst from the interaction of intense laser (I = 10{sup 14 }W/cm{sup 2}, 600 ps) with a thin Cu foil. 2D Particle-In-Cell (PIC) simulation well reproduces the collimated <span class="hlt">electron</span> beam with a strong magnetic field in the region of the laser pulse propagation. To understand the physical mechanism of the collimation, we calculate energetic <span class="hlt">electron</span> motion in the magnetic field obtained from the 2D PIC simulation. As the results, the strong magnetic field (300 MG) collimates <span class="hlt">electrons</span> with energy over a few MeV. This collimation mechanism may attract attention in many applications such as <span class="hlt">electron</span> acceleration, <span class="hlt">electron</span> microscope and fast ignition of laser fusion.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2006ApPhL..89v3523M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2006ApPhL..89v3523M"><span>SF6/O2 <span class="hlt">plasma</span> effects on silicon nitride passivation of AlGaN /GaN high <span class="hlt">electron</span> mobility transistors</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Meyer, David J.; Flemish, Joseph R.; Redwing, Joan M.</p> <p>2006-11-01</p> <p>The effects of various <span class="hlt">plasma</span> and wet chemical surface pretreatments on the electrical characteristics of AlGaN /GaN high <span class="hlt">electron</span> mobility transistors (HEMTs) passivated with <span class="hlt">plasma</span>-deposited silicon nitride were investigated. The results of pulsed IV measurements show that samples exposed to various SF6/O2 <span class="hlt">plasma</span> treatments have markedly better rf dispersion characteristics compared to samples that were either untreated or treated in wet buffered oxide etch prior to encapsulation. The improvement in these characteristics correlates with the reduction of carbon on the semiconductor surface as measured with x-ray photoelectron spectroscopy. HEMT channel <span class="hlt">sheet</span> resistance was also affected by varying silicon nitride deposition parameters.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2002cosp...34E2101K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2002cosp...34E2101K"><span>Unfolding ambient <span class="hlt">electron</span> <span class="hlt">plasma</span> density from wave spectra induced by <span class="hlt">electron</span> beam</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kiraga, A.; Klos, Z.; Oraevsky, V.; Dokukin, V.; Pulinets, S.</p> <p></p> <p>Numerous rocket and few satellite projects were devoted to study of astrophysical <span class="hlt">plasma</span> with the aid of active <span class="hlt">electron</span> beam experiments. The quality and volume of wave data from such experiments did not fulfill original expectat ions due to complexity of involved processes, technical malfunctions and limited diagnostics. Due to fortunate, temporal malfunction of <span class="hlt">plasma</span> accelerator, there were several cases when pulsed <span class="hlt">electron</span> beam had been injected from the APEX satellite into otherwise unmodified ionospheric <span class="hlt">plasma</span>. Instantaneous current intensity didn't exceeded 0.15A and an unstabilized acceleration voltage was of the order of 10keV. Injection pitch angle slowly changed according to moderate three-axis satellite stabilization. Injections took place in the altitude range 400-1100km in the European region and in the north, polar region. A receiver with bandwidth of 15kHz was connected to a cylindrical dipole antenna having half lengths of 7.5m. The receiver operated in survey mode providing one spectrum every 2s or 8s. The single spectrum was measured in 1s with an equally spaced mesh of 200 frequencies starting from 100kHz with a step of 50kHz. <span class="hlt">Electron</span> beam induced spectra show up large variety of narrow band structures. In many cases, from reproducibility or slow evolution of the spectra, it may be inferred that distinct interactions prevail for some ranges of ambient <span class="hlt">electron</span> gyro (fc) and <span class="hlt">plasma</span> (fn) frequencies, injection pitch angles and beam intensity. Interaction plausibility arguments are useful in preliminary assignment of spectral structures. We show that discrete emission can be identified at least on ambient <span class="hlt">plasma</span> frequency or ambient upper hybrid frequency. One class of arguments supporting such identification is provided by interrelation between spectral signatures of local <span class="hlt">plasma</span> density in passive mode and beam induced spectra. Another class of arguments is provided by interrelations between spectral structures induced by <span class="hlt">electron</span> beam</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016JGRA..121.1219C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016JGRA..121.1219C"><span>Resonant scattering of central <span class="hlt">plasma</span> <span class="hlt">sheet</span> protons by multiband EMIC waves and resultant proton loss timescales</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Cao, Xing; Ni, Binbin; Liang, Jun; Xiang, Zheng; Wang, Qi; Shi, Run; Gu, Xudong; Zhou, Chen; Zhao, Zhengyu; Fu, Song; Liu, Jiang</p> <p>2016-02-01</p> <p>This is a companion study to Liang et al. (2014) which reported a "reversed" energy-latitude dispersion pattern of ion precipitation in that the lower energy ion precipitation extends to lower latitudes than the higher-energy ion precipitation. Electromagnetic ion cyclotron (EMIC) waves in the central <span class="hlt">plasma</span> <span class="hlt">sheet</span> (CPS) have been suggested to account for this reversed-type ion precipitation. To further investigate the association, we perform a comprehensive study of pitch angle diffusion rates induced by EMIC wave and the resultant proton loss timescales at L = 8-12 around the midnight. Comparing the proton scattering rates in the Earth's dipole field and a more realistic quiet time geomagnetic field constructed from the Tsyganenko 2001 (T01) model, we find that use of a realistic, nondipolar magnetic field model not only decreases the minimum resonant energies of CPS protons but also considerably decreases the limit of strong diffusion and changes the proton pitch angle diffusion rates. Adoption of the T01 model increases EMIC wave diffusion rates at > ~ 60° equatorial pitch angles but decreases them at small equatorial pitch angles. Pitch angle scattering coefficients of 1-10 keV protons due to H+ band EMIC waves can exceed the strong diffusion rate for both geomagnetic field models. While He+ and O+ band EMIC waves can only scatter tens of keV protons efficiently to cause a fully filled loss cone at L > 10, in the T01 magnetic field they can also cause efficient scattering of ~ keV protons in the strong diffusion limit at L > 10. The resultant proton loss timescales by EMIC waves with a nominal amplitude of 0.2 nT vary from a few hours to several days, depending on the wave band and L shell. Overall, the results demonstrate that H+ band EMIC waves, once present, can act as a major contributor to the scattering loss of a few keV protons at lower L shells in the CPS, accounting for the reversed energy-latitude dispersion pattern of proton precipitation at low</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2604932','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2604932"><span><span class="hlt">Electron</span> tomography of early melanosomes: Implications for melanogenesis and the generation of fibrillar amyloid <span class="hlt">sheets</span></span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Hurbain, Ilse; Geerts, Willie J. C.; Boudier, Thomas; Marco, Sergio; Verkleij, Arie J.; Marks, Michael S.; Raposo, Graç</p> <p>2008-01-01</p> <p>Melanosomes are lysosome-related organelles (LROs) in which melanins are synthesized and stored. Early stage melanosomes are characterized morphologically by intralumenal fibrils upon which melanins are deposited in later stages. The integral membrane protein Pmel17 is a component of the fibrils, can nucleate fibril formation in the absence of other pigment cell-specific proteins, and forms amyloid-like fibrils in vitro. Before fibril formation Pmel17 traffics through multivesicular endosomal compartments, but how these compartments participate in downstream events leading to fibril formation is not fully known. By using high-pressure freezing of MNT-1 melanoma cells and freeze substitution to optimize ultrastructural preservation followed by double tilt 3D <span class="hlt">electron</span> tomography, we show that the amyloid-like fibrils begin to form in multivesicular compartments, where they radiate from the luminal side of intralumenal membrane vesicles. The fibrils in fully formed stage II premelanosomes organize into <span class="hlt">sheet</span>-like arrays and exclude the remaining intralumenal vesicles, which are smaller and often in continuity with the limiting membrane. These observations indicate that premelanosome fibrils form in association with intralumenal endosomal membranes. We suggest that similar processes regulate amyloid formation in pathological models. PMID:19033461</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26824166','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26824166"><span><span class="hlt">Sheet</span> Size-Induced Evaporation Behaviors of Inkjet-Printed Graphene Oxide for Printed <span class="hlt">Electronics</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Kim, Haena; Jang, Jeong In; Kim, Hyun Ho; Lee, Geon-Woong; Lim, Jung Ah; Han, Joong Tark; Cho, Kilwon</p> <p>2016-02-10</p> <p>The size of chemically modified graphene nanosheets is a critical parameter that affects their performance and applications. Here, we show that the lateral size of graphene oxide (GO) nanosheets is strongly correlated with the concentration of graphite oxide present in the suspension as graphite oxide is exfoliated by sonication. The size of the GO nanosheets increased from less than 100 nm to several micrometers as the concentration of graphite oxide in the suspension was increased up to a critical concentration. An investigation of the evaporation behavior of the GO nanosheet solution using inkjet printing revealed that the critical temperature of formation of a uniform film, T(c), was lower for the large GO nanosheets than for the small GO nanosheets. This difference was attributed to the interactions between the two-dimensional structures of GO nanosheets and the substrate as well as the interactions among the GO nanosheets. Furthermore, we fabricated organic thin film transistors (OTFTs) using line-patterned reduced GO as electrodes. The OTFTs displayed different electrical performances, depending on the graphene <span class="hlt">sheet</span> size. We believe that our new strategy to control the size of GO nanosheets and our findings about the colloidal and electrical properties of size-controlled GO nanosheets will be very effective to fabricate graphene based printed <span class="hlt">electronics</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015MNRAS.448..606C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015MNRAS.448..606C"><span>Particle acceleration in axisymmetric pulsar current <span class="hlt">sheets</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Cerutti, Benoît; Philippov, Alexander; Parfrey, Kyle; Spitkovsky, Anatoly</p> <p>2015-03-01</p> <p>The equatorial current <span class="hlt">sheet</span> in pulsar magnetospheres is often regarded as an ideal site for particle acceleration via relativistic reconnection. Using 2D spherical particle-in-cell simulations, we investigate particle acceleration in the axisymmetric pulsar magnetosphere as a function of the injected <span class="hlt">plasma</span> multiplicity and magnetization. We observe a clear transition from a highly charge-separated magnetosphere for low <span class="hlt">plasma</span> injection with little current and spin-down power, to a nearly force-free solution for high <span class="hlt">plasma</span> multiplicity characterized by a prominent equatorial current <span class="hlt">sheet</span> and high spin-down power. We find significant magnetic dissipation in the current <span class="hlt">sheet</span>, up to 30 per cent within 5 light-cylinder radii in the high-multiplicity regime. The simulations unambiguously demonstrate that the dissipated Poynting flux is efficiently channelled to the particles in the <span class="hlt">sheet</span>, close to the Y-point within about 1-2 light-cylinder radii from the star. The mean particle energy in the <span class="hlt">sheet</span> is given by the upstream <span class="hlt">plasma</span> magnetization at the light cylinder. The study of particle orbits shows that all energetic particles originate from the boundary layer between the open and the closed field lines. Energetic positrons always stream outwards, while high-energy <span class="hlt">electrons</span> precipitate back towards the star through the <span class="hlt">sheet</span> and along the separatrices, which may result in auroral-like emission. Our results suggest that the current <span class="hlt">sheet</span> and the separatrices may be the main source of high-energy radiation in young pulsars.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/21300445','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/21300445"><span>Achieving Long Confinement in a Toroidal <span class="hlt">Electron</span> <span class="hlt">Plasma</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Marler, J. P.; Smoniewski, J.; Ha Bao; Stoneking, M. R.</p> <p>2009-03-30</p> <p>We observe the m = 1 diocotron mode in a partial toroidal trap, and use it as the primary diagnostic for observing the <span class="hlt">plasma</span> confinement. The frequency of the m = 1 mode, which is approximately proportional to the trapped charge, decays on a three second timescale. The confinement time exceeds, by at least an order of magnitude, the confinement observed in all other toroidal traps for non-neutral <span class="hlt">plasmas</span> and approaches the theoretical limit set by magnetic pumping transport. Numerical simulations that include toroidal effects are employed to accurately extract <span class="hlt">plasma</span> charge, equilibrium position and m = 1 mode amplitude from the experimental data. Future work will include attempts to withdraw the <span class="hlt">electron</span> source in order to study confinement in a full torus.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19860032443&hterms=average+temperature&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3Daverage%2Btemperature','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19860032443&hterms=average+temperature&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3Daverage%2Btemperature"><span><span class="hlt">Electron</span> temperature and average density in spherical laser-produced <span class="hlt">plasmas</span> - Ultraviolet <span class="hlt">plasma</span> spectroscopy</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Goldsmith, S.; Seely, J. F.; Feldman, U.; Behring, W. E.; Cohen, L.</p> <p>1985-01-01</p> <p>The average values of the <span class="hlt">electron</span> temperature Te and the <span class="hlt">electron</span> density Ne in the corona <span class="hlt">plasmas</span> of spherically irradiated high-Z targets have been estimated. Targets composed of the elements Cu through Br, Rb, and Mo were irradiated using the fundamental (1.06 microns) and the frequency-tripled (351 nm) output of the Omega laser system. Spectra were recorded in the wavelength region 15-200 A. Using various extreme ultraviolet spectroscopic techniques, it is found that for the case of a Mo <span class="hlt">plasma</span> produced by frequency-tripled laser irradiation, Te = 2600 + or - 600 eV and Ne is greater than 6 x 10 to the 20th/cu cm. This is consistent with a 'flux limit' smaller than 0.1. The estimated values of Te and Ne are lower in the corona <span class="hlt">plasmas</span> produced using the fundamental (1.06 micron) irradiation.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015PSST...24b4001L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015PSST...24b4001L"><span><span class="hlt">Electron</span> heating and control of <span class="hlt">electron</span> energy distribution for the enhancement of the <span class="hlt">plasma</span> ashing processing</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Lee, Hyo-Chang; Chung, Chin-Wook</p> <p>2015-04-01</p> <p>Control of the <span class="hlt">electron</span> energy distribution function (EEDF) is investigated through applying an inductive field in oxygen capacitively coupled <span class="hlt">plasma</span> (CCP). With the addition of a small amount of antenna coil power to the CCP, low energy <span class="hlt">electrons</span> are effectively heated and the EEDF is controlled. This method is applied to the ashing process of the photoresistor (PR). It is revealed that the ashing rate of the PR is significantly increased due to O radicals produced by the controlled EEDF, even though the ion density/energy flux is not increased. The roles of the power transfer mode in the <span class="hlt">electron</span> heating and <span class="hlt">plasma</span> control are also presented in the hybrid <span class="hlt">plasma</span> source with inductive and capacitive fields. This work provides a route to enhance or control the processing result.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016APS..DPPTI3003D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016APS..DPPTI3003D"><span>Evolution of an <span class="hlt">electron</span> <span class="hlt">plasma</span> vortex in a strain flow</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Danielson, J. R.</p> <p>2016-10-01</p> <p>Coherent vortex structures are ubiquitous in fluids and <span class="hlt">plasmas</span> and are examples of self-organized structures in nonlinear dynamical systems. The fate of these structures in strain and shear flows is an important issue in many physical systems, including geophysical fluids and shear suppression of turbulence in <span class="hlt">plasmas</span>. In two-dimensions, an inviscid, incompressible, ideal fluid can be modeled with the Euler equations, which is perhaps the simplest system that supports vortices. The Drift-Poisson equations for pure <span class="hlt">electron</span> <span class="hlt">plasmas</span> in a strong, uniform magnetic field are isomorphic to the Euler equations, and so <span class="hlt">electron</span> <span class="hlt">plasmas</span> are an excellent test bed for the study of 2D vortex dynamics. This talk will describe results from a new experiment using pure <span class="hlt">electron</span> <span class="hlt">plasmas</span> in a specially designed Penning-Malmberg (PM) trap to study the evolution of an initially axisymmetric 2D vortex subject to externally imposed strains. Complementary vortex-in-cell simulations are conducted to validate the 2D nature of the experimental results and to extend the parameter range of these studies. Data for vortex destruction using both instantaneously applied and time dependent strains with flat (constant vorticity) and extended radial profiles will be presented. The role of vortex self-organization will be discussed. A simple 2D model works well for flat vorticity profiles. However, extended profiles exhibit more complicated behavior, such as filamentation and stripping; and these effects and their consequences will be discussed. Work done in collaboration with N. C. Hurst, D. H. E. Dubin, and C. M. Surko.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016EPJD...70..252M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016EPJD...70..252M"><span>Low frequency nonlinear waves in <span class="hlt">electron</span> depleted magnetized nonthermal <span class="hlt">plasmas</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Mobarak Hossen, Md.; Sahadat Alam, Md.; Sultana, Sharmin; Mamun, A. A.</p> <p>2016-11-01</p> <p>A theoretical study on the ultra-low frequency small but finite amplitude solitary waves has been carried out in an <span class="hlt">electron</span> depleted magnetized nonthermal dusty <span class="hlt">plasma</span> consisting of both polarity (positively charged as well as negatively charged) inertial massive dust particles and nonextensive q distributed ions. The reductive perturbation technique is employed to derive the ZakharovKuznetsov (ZK) equation. The basic features of low frequency solitary wave are analyzed via the solution of ZK equation. It is observed that the intrinsic properties (e.g., polarity, amplitude, width, etc.) of dust-acoustic (DA) solitary waves (SWs) are significantly influenced by the effects external magnetic field, obliqueness, nonextensivity of ions, and the ratio of ion number density to the product of <span class="hlt">electron</span> and negative dust number density. The findings of our results may be useful to explain the low frequency nonlinear wave propagation in some <span class="hlt">plasma</span> environments like cometary tails, the earth polar mesosphere, Jupiter's magnetosphere, etc.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016AAS...22830903H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016AAS...22830903H"><span>Modeling <span class="hlt">Plasmas</span> with a Kappa <span class="hlt">Electron</span> Energy Distribution</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Hahn, Michael; Savin, Daniel Wolf</p> <p>2016-06-01</p> <p>Nonthermal kappa <span class="hlt">electron</span> energy distributions have been observed in the Earth's magnetosphere and the solar wind, and are likely also present in the solar corona and in solar flares. In order to model the spectra of these <span class="hlt">plasmas</span>, it is necessary to obtain the appropriate collision rate coefficients. We show that this can be done simply by summing appropriately weighted Maxwellian rate coefficients. The resulting data have similar or better accuracies than are obtained with other approaches. Summing Maxwellians has the additional advantages of being easy to implement and extendable to many different collision processes. We apply this technique to modeling the charge state distribution (CSD) of kappa-distribution <span class="hlt">plasmas</span>. In particular, we examine the influence of <span class="hlt">electron</span> impact multiple ionization on the equilibrium CSD and calculate the time variation of the CSD during a solar flare.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016SPD....47.0901H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016SPD....47.0901H"><span>Modeling <span class="hlt">Plasmas</span> with a Kappa <span class="hlt">Electron</span> Energy Distribution</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Hahn, Michael; Savin, Daniel Wolf</p> <p>2016-05-01</p> <p>Nonthermal kappa <span class="hlt">electron</span> energy distributions have been observed in the Earth's magnetosphere and the solar wind, and are likely also present in the solar corona and in solar flares. In order to model the spectra of these <span class="hlt">plasmas</span>, it is necessary to obtain the appropriate collision rate coefficients. We show that this can be done simply by summing appropriately weighted Maxwellian rate coefficients. The resulting data have similar or better accuracies than are obtained with other approaches. Summing Maxwellians has the additional advantages of being easy to implement and extendable to many different collision processes. We apply this technique to modeling the charge state distribution (CSD) of kappa-distribution <span class="hlt">plasmas</span>. In particular, we examine the influence of <span class="hlt">electron</span> impact multiple ionization on the equilibrium CSD and calculate the time variation of the CSD during a solar flare.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/22254891','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/22254891"><span>A novel <span class="hlt">electron</span> density reconstruction method for asymmetrical toroidal <span class="hlt">plasmas</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Shi, N.; Ohshima, S.; Minami, T.; Nagasaki, K.; Yamamoto, S.; Mizuuchi, T.; Okada, H.; Kado, S.; Kobayashi, S.; Konoshima, S.; Sano, F.; Tanaka, K.; Ohtani, Y.; Zang, L.; Kenmochi, N.</p> <p>2014-05-15</p> <p>A novel reconstruction method is developed for acquiring the <span class="hlt">electron</span> density profile from multi-channel interferometric measurements of strongly asymmetrical toroidal <span class="hlt">plasmas</span>. It is based on a regularization technique, and a generalized cross-validation function is used to optimize the regularization parameter with the aid of singular value decomposition. The feasibility of method could be testified by simulated measurements based on a magnetic configuration of the flexible helical-axis heliotron device, Heliotron J, which has an asymmetrical poloidal cross section. And the successful reconstruction makes possible to construct a multi-channel Far-infrared laser interferometry on this device. The advantages of this method are demonstrated by comparison with a conventional method. The factors which may affect the accuracy of the results are investigated, and an error analysis is carried out. Based on the obtained results, the proposed method is highly promising for accurately reconstructing the <span class="hlt">electron</span> density in the asymmetrical toroidal <span class="hlt">plasma</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012JPhCS.370a2012V','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012JPhCS.370a2012V"><span>Application of <span class="hlt">electron</span> beam <span class="hlt">plasma</span> for biopolymers modification</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Vasilieva, T. M.</p> <p>2012-06-01</p> <p>The effects of the <span class="hlt">Electron</span> Beam <span class="hlt">Plasma</span> treatment on natural polysaccharide chitosan were studied experimentally. Low molecular water-soluble products of chitosan and chitooligosaccharides were obtained by treating the original polymers in the <span class="hlt">Electron</span> Beam <span class="hlt">Plasma</span> of oxygen and water vapor. The molecular mass of the products varied from 18 kDa to monomeric fragments. The degradation of the original polymers was due to the action of active oxygen particles (atomic and singlet oxygen) and the particles of the water plasmolysis (hydroxyl radicals, hydrogen peroxides). The 95% yield of low molecular weight chitosans was attained by optimizing the treatment conditions. The studies of the antimicrobial activity of low molecular products showed that they strongly inhibit the multiplication of colon bacillus, aurococcus and yeast-like fungi. The EBP-stimulated degradation of polysaccharides and proteins were found to result from breaking β-1,4 glycosidic bounds and peptide bonds, respectively.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013APS..DPPYO6007J','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013APS..DPPYO6007J"><span>Cathode <span class="hlt">Plasma</span> Formation in High Intensity <span class="hlt">Electron</span> Beam Diodes</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Johnston, Mark; Kiefer, Mark; Oliver, Bryan; Bennett, Nichelle; Droemer, Darryl; Bernshtam, V.; Doron, R.; Maron, Yitzhak</p> <p>2013-10-01</p> <p>This talk will detail the experimental results and conclusions obtained for cathode <span class="hlt">plasma</span> formation on the Self-Magnetic Pinch (SMP) diode fielded on the RITS-6 accelerator (4-7.5 MeV) at Sandia National Laboratories. The SMP diode utilizes a hollowed metal cathode to produce high power (TW), focused <span class="hlt">electron</span> beams (<3 mm diameter) which are used for flash x-ray radiography applications. Optical diagnostics include high speed (<10 ns) framing cameras, optical streak cameras, and spectroscopy. The cathode <span class="hlt">plasma</span> in this high electric (MV/cm) and magnetic (>10 Tesla) field environment forms well-defined striations. These striations have been examined for a number of different cathode sizes, vacuum gap spacings, and diode voltages. Optical streak images have been taken to determine the time evolution of the <span class="hlt">plasma</span>, and optical spectroscopy has been employed to determine its constituents as well as their densities and temperatures inferred from detailed time-dependent, collisional-radiative (CR) and radiation transport modelings. Comments will be made as to the overall effect of the cathode <span class="hlt">plasma</span> in regards to the diode impedance and <span class="hlt">electron</span> beam focusing. Sandia National Laboratories is a multi-program laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for the U.S. Department of Energy's National Nuclear Security Administration under contract DE-AC04-94AL85000.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/21599373','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/21599373"><span><span class="hlt">Plasma</span> jet braking: energy dissipation and nonadiabatic <span class="hlt">electrons</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Khotyaintsev, Yu V; Cully, C M; Vaivads, A; André, M; Owen, C J</p> <p>2011-04-22</p> <p>We report in situ observations by the Cluster spacecraft of wave-particle interactions in a magnetic flux pileup region created by a magnetic reconnection outflow jet in Earth's magnetotail. Two distinct regions of wave activity are identified: lower-hybrid drift waves at the front edge and whistler-mode waves inside the pileup region. The whistler-mode waves are locally generated by the <span class="hlt">electron</span> temperature anisotropy, and provide evidence for ongoing betatron energization caused by magnetic flux pileup. The whistler-mode waves cause fast pitch-angle scattering of <span class="hlt">electrons</span> and isotropization of the <span class="hlt">electron</span> distribution, thus making the flow braking process nonadiabatic. The waves strongly affect the <span class="hlt">electron</span> dynamics and thus play an important role in the energy conversion chain during <span class="hlt">plasma</span> jet braking.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2011PhRvL.106p5001K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011PhRvL.106p5001K"><span><span class="hlt">Plasma</span> Jet Braking: Energy Dissipation and Nonadiabatic <span class="hlt">Electrons</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Khotyaintsev, Yu. V.; Cully, C. M.; Vaivads, A.; André, M.; Owen, C. J.</p> <p>2011-04-01</p> <p>We report in situ observations by the Cluster spacecraft of wave-particle interactions in a magnetic flux pileup region created by a magnetic reconnection outflow jet in Earth’s magnetotail. Two distinct regions of wave activity are identified: lower-hybrid drift waves at the front edge and whistler-mode waves inside the pileup region. The whistler-mode waves are locally generated by the <span class="hlt">electron</span> temperature anisotropy, and provide evidence for ongoing betatron energization caused by magnetic flux pileup. The whistler-mode waves cause fast pitch-angle scattering of <span class="hlt">electrons</span> and isotropization of the <span class="hlt">electron</span> distribution, thus making the flow braking process nonadiabatic. The waves strongly affect the <span class="hlt">electron</span> dynamics and thus play an important role in the energy conversion chain during <span class="hlt">plasma</span> jet braking.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/21550326','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/21550326"><span><span class="hlt">Plasma</span> Jet Braking: Energy Dissipation and Nonadiabatic <span class="hlt">Electrons</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Khotyaintsev, Yu. V.; Cully, C. M.; Vaivads, A.; Andre, M.; Owen, C. J.</p> <p>2011-04-22</p> <p>We report in situ observations by the Cluster spacecraft of wave-particle interactions in a magnetic flux pileup region created by a magnetic reconnection outflow jet in Earth's magnetotail. Two distinct regions of wave activity are identified: lower-hybrid drift waves at the front edge and whistler-mode waves inside the pileup region. The whistler-mode waves are locally generated by the <span class="hlt">electron</span> temperature anisotropy, and provide evidence for ongoing betatron energization caused by magnetic flux pileup. The whistler-mode waves cause fast pitch-angle scattering of <span class="hlt">electrons</span> and isotropization of the <span class="hlt">electron</span> distribution, thus making the flow braking process nonadiabatic. The waves strongly affect the <span class="hlt">electron</span> dynamics and thus play an important role in the energy conversion chain during <span class="hlt">plasma</span> jet braking.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li class="active"><span>25</span></li> <li><