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Sample records for plasma sheet electrons

  1. 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.

  2. 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> fluxes can be used as an input to the radiation belt models. This seed population for radiation belts will affect the local acceleration up to relativistic energies.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://lasp.colorado.edu/~lix/paper/JGR/08/Burin-des-Roziers.pdf','EPRINT'); return false;" href="http://lasp.colorado.edu/~lix/paper/JGR/08/Burin-des-Roziers.pdf"><span id="translatedtitle">Energetic <span class="hlt">plasma</span> <span class="hlt">sheet</span> <span class="hlt">electrons</span> and their relationship with the solar wind: A Cluster and Geotail study</span></a></p> <p><a target="_blank" href="http://www.osti.gov/eprints/">E-print Network</a></p> <p>Li, Xinlin</p> <p></p> <p>Energetic <span class="hlt">plasma</span> <span class="hlt">sheet</span> <span class="hlt">electrons</span> and their relationship with the solar wind: A Cluster and Geotail and the solar wind, as well as >2 MeV geosynchronous <span class="hlt">electrons</span>, is investigated using <span class="hlt">plasma</span> <span class="hlt">sheet</span> measurements from Cluster (2001­2005) and Geotail (1998­2005) and concurrent solar wind measurements from ACE</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/25638082','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/25638082"><span id="translatedtitle">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="http://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. PMID:25638082</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015RScI...86a3503K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015RScI...86a3503K"><span id="translatedtitle">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="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kumar, Niraj; Narayan Pal, Udit; Kumar Pal, Dharmendra; 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/cm2 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('http://adsabs.harvard.edu/abs/1987steh.rept.....U','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1987steh.rept.....U"><span id="translatedtitle">Confinement time of <span class="hlt">electrons</span> and H(-)/D(-) ions in the Uramoto type <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>Uramoto, Joshin</p> <p>1987-10-01</p> <p>Confinement times of <span class="hlt">electrons</span> and H(-)/D(-) ions in the Uramoto type <span class="hlt">sheet</span> <span class="hlt">plasma</span> as a H(-)/D(-) ion source of volume production are determined from e-folding decay times of negative current to a Langmuir probe, after a discharge for the <span class="hlt">sheet</span> <span class="hlt">plasma</span> production is stopped through SCR connected between the anode and the cathode. The confinement times depend mainly on a bias potential of the metal vacuum chamber outside of the <span class="hlt">sheet</span> <span class="hlt">plasma</span>, which are ranging from about 40 microsec (for plus bias voltage with respect to the anode) to about 300 microsec (for minus bias voltage). Then, in order to extract a volume produced H(-)/D(-) ion current in high efficiency, it is shown that a long confinement time is an important necessary condition with the two necessary conditions (high <span class="hlt">electron</span> density in low <span class="hlt">electron</span> temperature and <span class="hlt">electron</span> beam components) reported already.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1990CRLJ...37...15O','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1990CRLJ...37...15O"><span id="translatedtitle">Broad-band auroral hiss and inverted-V <span class="hlt">electrons</span> precipitated from the boundary <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>Ondoh, Tadanori</p> <p>1990-03-01</p> <p>A polar occurrence map of broad-band auroral hiss was obtained from ISIS VLF data and is compared to a polar occurrence map for inverted-V <span class="hlt">electron</span> precipitation events observed by Atmospheric Explorer-D (Hoffman and Lin, 1981). It was found that both maps are qualitatively similar, especially, for the low-latitude boundary and 10-22 hour MLT symmetric meridian, indicating that the broadband auroral hiss is closely related to the inverted-V <span class="hlt">electrons</span> precipitated from the boundary <span class="hlt">plasma</span> <span class="hlt">sheet</span>. The frequency range of the hiss is discussed in terms of whistler-mode Cherenkov radiation by inverted-V <span class="hlt">electron</span> precipitated from the boundary <span class="hlt">plasma</span> <span class="hlt">sheet</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19940033533&hterms=Earth+layers&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3DEarth%2527s%2Blayers','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19940033533&hterms=Earth+layers&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3DEarth%2527s%2Blayers"><span id="translatedtitle"><span class="hlt">Electron</span> generation of electrostatic waves 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>Onsager, T. G.; Thomsen, M. F.; Elphic, R. C.; Gosling, J. T.; Anderson, R. R.; Kettmann, G.</p> <p>1993-01-01</p> <p>Broadband electrostatic noise (BEN) has been shown to occur in conjunction with ion beams; extensive investigations of possible ion beam-related instabilities that could generate the observed wave spectra have been conducted. It has also been demonstrated that unstable <span class="hlt">electron</span> distribution functions are sometimes measured in the <span class="hlt">plasma</span> <span class="hlt">sheet</span> boundary layer. We present simultaneous observations of ion and <span class="hlt">electron</span> distribution functions and electric field wave spectra measured by ISEE 1 and ISEE 2 in the Earth's magnetotail. As the spacecraft moved from the tail lobe toward the <span class="hlt">plasma</span> <span class="hlt">sheet</span>, the fast indication of boundary layer <span class="hlt">plasma</span> was seen in the <span class="hlt">electron</span> distributions, followed some minutes later by the detection of boundary layer ions. The onset of large-amplitude electrostatic waves at frequencies up to the <span class="hlt">electron</span> <span class="hlt">plasma</span> frequency was coincident with the onset of the boundary layer <span class="hlt">electrons</span>, suggesting that broadband electrostatic waves may often be generated by unstable <span class="hlt">electron</span> distributions in the <span class="hlt">plasma</span> <span class="hlt">sheet</span> boundary layer, particularly the higher frequency portion of the wave spectrum. The observed changes in the <span class="hlt">electron</span> distribution functions indicate that the <span class="hlt">plasma</span> was not heated locally by the waves.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19990095983&hterms=electron&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DTitle%26N%3D0%26No%3D20%26Ntt%3Delectron','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19990095983&hterms=electron&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DTitle%26N%3D0%26No%3D20%26Ntt%3Delectron"><span id="translatedtitle">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, Thomas 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 entire 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://hdl.handle.net/2060/19990071231','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19990071231"><span id="translatedtitle">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/22392313','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/22392313"><span id="translatedtitle">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('http://www.osti.gov/scitech/biblio/22303433','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/22303433"><span id="translatedtitle"><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 ?/?{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://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="http://ntrs.nasa.gov/search.jsp?R=19880052817&hterms=Beans&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3DBeans"><span id="translatedtitle">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> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2008PhPl...15b2504B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2008PhPl...15b2504B"><span id="translatedtitle">Study of magnetic configuration effects on <span class="hlt">plasma</span> boundary and measurement of edge <span class="hlt">electron</span> density in the spherical tokamak compact <span class="hlt">plasma</span> wall interaction experimental device using Li <span class="hlt">sheet</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>Bhattacharyay, R.; Zushi, H.; Morisaki, T.; Inada, Y.; Kikukawa, T.; Watanabe, S.; Sasaki, K.; Ryoukai, T.; Hasegawa, M.; Hanada, K.; Sato, K. N.; Nakamura, K.; Sakamoto, M.; Idei, H.; Yoshinaga, T.; Kawasaki, S.; Nakashima, H.; Higashijima, A.</p> <p>2008-02-01</p> <p>Two-dimensional lithium beam imaging technique has been applied in the spherical tokamak CPD (compact <span class="hlt">plasma</span> wall interaction experimental device) to study the effects of magnetic field configurations on rf <span class="hlt">plasma</span> boundary in the absence of any <span class="hlt">plasma</span> current, and also for the measurement of a two-dimensional edge <span class="hlt">electron</span> density profile. With the present working condition of the diagnostics, the minimum measured <span class="hlt">electron</span> density can be ˜1.0×1016m-3; this is considered to be the definition for the <span class="hlt">plasma</span> boundary. The performance of the lithium <span class="hlt">sheet</span> beam is absolutely calibrated using a quartz crystal monitor. Experimental results reveal that magnetic field configuration, either mirror or so-called null, critically affects the rf <span class="hlt">plasma</span> boundary. A sharp lower boundary is found to exist in magnetic null configuration, which is quite different from that in the weak mirror configuration. Theoretical calculations of particle drift orbit and magnetic connection length (wall-to-wall) suggest that only mirror trapped particles are confined within a region where the magnetic connection length is ˜4.0m or more. A two-dimensional edge <span class="hlt">electron</span> density profile is obtained from the observed LiI intensity profile. Overdense <span class="hlt">plasma</span> formation is discussed from the viewpoint of mode conversion of rf wave into <span class="hlt">electron</span> Bernstein wave and its dependence on the <span class="hlt">electron</span> density profile.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014PhDT.......138S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014PhDT.......138S"><span id="translatedtitle"><span class="hlt">Sheet</span> <span class="hlt">electron</span> beam tester</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Spear, Alexander Grenbeaux</p> <p></p> <p>The DARPA HiFIVE project uses a pulsed <span class="hlt">electron</span> <span class="hlt">sheet</span> beam gun to power a traveling wave tube amplifier operating at 220 GHz. Presented is a method for characterizing the high current density 0.1 mm by 1 mm <span class="hlt">sheet</span> <span class="hlt">electron</span> beam. A tungsten tipped probe was scanned through the cross section of the <span class="hlt">sheet</span> <span class="hlt">electron</span> beam inside of a vacuum vessel. The probe was controlled with sub-micron precision using stepper motors and LabView computer control while boxcar averaging hardware sampled the pulsed beam. Matlab algorithms were used to interpret the data, calculate beam dimensions and current density, and create 2-dimensional cross section images. Full characterization of two separate HiFIVE <span class="hlt">sheet</span> <span class="hlt">electron</span> guns was accomplished and is also presented.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2006JGRA..111.5206O','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2006JGRA..111.5206O"><span id="translatedtitle"><span class="hlt">Plasma</span> <span class="hlt">sheet</span> expansion: Statistical characteristics</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.; Mukai, T.</p> <p>2006-05-01</p> <p>The present study addresses the cause of <span class="hlt">plasma</span> <span class="hlt">sheet</span> expansion by statistically comparing the characteristics of lobe-to-<span class="hlt">plasma</span> <span class="hlt">sheet</span> (LB-to-PS) and PS-to-LB crossings observed by the Geotail satellite. Whereas the flapping motion of the magnetotail causes both types of crossing, the PS expansion (thinning) can be associated only with the LB-to-PS (PS-to-LB) crossing. Thus any systematic difference between the two types of crossing should reflect the difference between the PS expansion and thinning. Geotail observed more LB-to-PS crossings (744 events) than PS-to-LB crossings (640 events), and the preferred occurrence of the LB-to-PS crossing is more manifest closer to the Earth. It is found that at the PS-to-LB crossing, the <span class="hlt">plasma</span> moves in the same direction as the boundary motion. At the LB-to-PS crossing, in contrast, the <span class="hlt">plasma</span> often moves in the opposite direction to the boundary motion, indicating that there is a finite electric field in the frame of the boundary motion associated with the PS expansion. The PS expansion is therefore considered to be a manifestation of magnetic reconnection. That is, the PS expands because new PS flux tubes are added onto the preexisting PS. In the course of the PS expansion, the total pressure decreases, which may be interpreted in terms of the replacement of the preexisting PS <span class="hlt">plasma</span> with new low-pressure <span class="hlt">plasma</span> originating from the tail lobe. The PS expansion is also characterized by relaxation (dipolarization) of the local magnetic field, which is inferred to be a direct consequence of reconnection. On the basis of recent reports of the lack of a one-to-one correspondence between reconnection and substorm onset, it is suggested that the PS expansion cannot be uniquely associated with a specific substorm phase.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/6315139','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/6315139"><span id="translatedtitle">Pressure balance between lobe and <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>Baumjohann, W.; Paschmann, G. ); Luehr, H. )</p> <p>1990-01-01</p> <p>Using eight months of AMPTE/IRM <span class="hlt">plasma</span> and magnetic field data, the authors have done a statistical survey on the balance of total (thermal and magnetic) pressure in the Earth's <span class="hlt">plasma</span> <span class="hlt">sheet</span> and tail lobe. About 300,000 measurements obtained in the <span class="hlt">plasma</span> <span class="hlt">sheet</span> and the lobe were compared for different levels of magnetic activity as well as different distances from the Earth. The data show that lobe and <span class="hlt">plasma</span> <span class="hlt">sheet</span> pressure balance very well. Even in the worst case they do not deviate by more than half of the variance in the data itself. Approximately constant total pressure was also seen during a quiet time pass when IRM traversed nearly the whole magnetotail in the vertical direction, from the southern hemisphere lobe through the neutral <span class="hlt">sheet</span> and into the northern <span class="hlt">plasma</span> <span class="hlt">sheet</span> boundary layer.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://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="http://ntrs.nasa.gov/search.jsp?R=19920034377&hterms=IRM&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3DIRM"><span id="translatedtitle">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://ntrs.nasa.gov/search.jsp?R=19850029387&hterms=McCarthy&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D70%26Ntt%3DMcCarthy%252C%2BR','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19850029387&hterms=McCarthy&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D70%26Ntt%3DMcCarthy%252C%2BR"><span id="translatedtitle">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://adsabs.harvard.edu/abs/2010AGUFMSH33C..05L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010AGUFMSH33C..05L"><span id="translatedtitle">Heliospheric current <span class="hlt">sheet</span> and <span class="hlt">plasma</span> <span class="hlt">sheet</span> crossings associated with heatflux dropouts: A statistical survey using STEREO observations</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Liu, Y.; Galvin, A. B.; Popecki, M.; Simunac, K.; Kistler, L. M.; Farrugia, C. J.; Moebius, E.; Jian, L.; Opitz, A.; Luhmann, J. G.</p> <p>2010-12-01</p> <p>We investigate the heliospheric current <span class="hlt">sheet</span> (HCS) crossing events and the related heliospheric <span class="hlt">plasma</span> <span class="hlt">sheet</span> (HPS) on both STEREO spacecraft from Mar, 1, 2008 to Dec, 31, 2008. Observed <span class="hlt">plasma</span> <span class="hlt">sheets</span> are categorized into two types based on their relative position to the current <span class="hlt">sheets</span>. Type I <span class="hlt">plasma</span> <span class="hlt">sheets</span> straddle the current <span class="hlt">sheets</span>, and type II <span class="hlt">plasma</span> <span class="hlt">sheets</span> are located on one side of the current <span class="hlt">sheets</span>. The <span class="hlt">electron</span> heat flux dropouts (HFD) are also documented for each type of <span class="hlt">plasma</span> <span class="hlt">sheets</span>. Initially, the investigation was limited to 39 ideal HCS crossings. Among the initial 39 HCS crossings in our study, 4 have no HPS, 21 have a type I HPS, and 13 a Type II HPS. Most of the Type II HCSs don’t show a HFD, but a large portion of type I HPSs show a HFD. Later, the study is generalized to all HCS events for which we can determine the actual time and properties of the HPS. This conclusion still holds when all the identifiable HPS are included in the study. Schematic plots summing the different magnetic field configurations are presented, and the potential origin of <span class="hlt">plasmas</span> forming the two types of HPS is discussed.</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://ntrs.nasa.gov/search.jsp?R=20060009466&hterms=Fgm&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3DFgm','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=20060009466&hterms=Fgm&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3DFgm"><span id="translatedtitle"><span class="hlt">Plasma</span> <span class="hlt">sheet</span> turbulence observed by Cluster II</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Weygand, James M.; Kivelson, M. G.; Khurana, K. K.; Schwarzl, H. K.; Thompson, S. M.; McPherron, R. L.; Balogh, A.; Kistler, L. M.; Goldstein, M. L.; Borovsky, J.</p> <p>2005-01-01</p> <p>Cluster fluxgate magnetometer (FGM) and ion spectrometer (CIS) data are employed to analyze magnetic field fluctuations within the <span class="hlt">plasma</span> <span class="hlt">sheet</span> during passages through the magnetotail region in the summers of 2001 and 2002 and, in particular, to look for characteristics of magnetohydrodynamic (MHD) turbulence. Power spectral indices determined from power spectral density functions are on average larger than Kolmogorov's theoretical value for fluid turbulence as well as Kraichnan's theoretical value for MHD <span class="hlt">plasma</span> turbulence. Probability distribution functions of the magnetic fluctuations show a scaling law over a large range of temporal scales with non-Gaussian distributions at small dissipative scales and inertial scales and more Gaussian distribution at large driving scales. Furthermore, a multifractal analysis of the magnetic field components shows scaling behavior in the inertial range of the fluctuations from about 20 s to 13 min for moments through the fifth order. Both the scaling behavior of the probability distribution functions and the multifractal structure function suggest that intermittent turbulence is present within the <span class="hlt">plasma</span> <span class="hlt">sheet</span>. The unique multispacecraft aspect and fortuitous spacecraft spacing allow us to examine the turbulent eddy scale sizes. Dynamic autocorrelation and cross correlation analysis of the magnetic field components allow us to determine that eddy scale sizes fit within the <span class="hlt">plasma</span> <span class="hlt">sheet</span>. These results suggest that magnetic field turbulence is occurring within the <span class="hlt">plasma</span> <span class="hlt">sheet</span> resulting in turbulent energy dissipation.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/doepatents/biblio/874183','DOE-PATENT-XML'); return false;" href="http://www.osti.gov/doepatents/biblio/874183"><span id="translatedtitle">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. (Midlothian, VA); Scorey, Clive (Cheshire, CT); Sikka, Vinod K. (Oak Ridge, TN); Deevi, Seetharama C. (Midlothian, VA); Fleischhauer, Grier (Midlothian, VA); Lilly, Jr., A. Clifton (Chesterfield, VA); German, Randall M. (State College, PA)</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('http://adsabs.harvard.edu/abs/2009PhPl...16e7103K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009PhPl...16e7103K"><span id="translatedtitle">Pulsed <span class="hlt">plasma</span> <span class="hlt">electron</span> sourcesa)</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Krasik, Ya. E.; Yarmolich, D.; Gleizer, J. Z.; Vekselman, V.; Hadas, Y.; Gurovich, V. Tz.; Felsteiner, J.</p> <p>2009-05-01</p> <p>There is a continuous interest in research of <span class="hlt">electron</span> sources which can be used for generation of uniform <span class="hlt">electron</span> beams produced at E ?105 V/cm and duration ?10-5 s. In this review, several types of <span class="hlt">plasma</span> <span class="hlt">electron</span> sources will be considered, namely, passive (metal ceramic, velvet and carbon fiber with and without CsI coating, and multicapillary and multislot cathodes) and active (ferroelectric and hollow anodes) <span class="hlt">plasma</span> sources. The operation of passive sources is governed by the formation of flashover <span class="hlt">plasma</span> whose parameters depend on the amplitude and rise time of the accelerating electric field. In the case of ferroelectric and hollow-anode <span class="hlt">plasma</span> sources the <span class="hlt">plasma</span> parameters are controlled by the driving pulse and discharge current, respectively. Using different time- and space-resolved electrical, optical, spectroscopical, Thomson scattering and x-ray diagnostics, the parameters of the <span class="hlt">plasma</span> and generated <span class="hlt">electron</span> beam were characterized.</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 id="translatedtitle">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 of the radiation at the Europa <span class="hlt">plasma</span> <span class="hlt">sheet</span> is from ions that originated at the orbit of Io. The stochastic observational evidence in disk averaged Europa oxygen emission obtained over the 1994 to 2012 period shows no indication of transient events. A significant neutral transient injection in the Europa <span class="hlt">plasma</span> <span class="hlt">sheet</span> would take of order year time-scales to relax to steady state</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/5384282','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/5384282"><span id="translatedtitle">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://www.osti.gov/scitech/biblio/5187554','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/5187554"><span id="translatedtitle">Superposed epoch analysis of the substorm <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>Baumjohann, W.; Paschmann, G. ); Nagai, T. ); Luehr, H. )</p> <p>1991-07-01</p> <p>More than 43,000 <span class="hlt">plasma</span> and magnetic field measurements with the AMPTE/IRM satellite in the magnetotail are used for a superposed epoch analysis of the conditions in the near-Earth <span class="hlt">plasma</span> <span class="hlt">sheet</span> around 39 major substorm onsets. In the central <span class="hlt">plasma</span> <span class="hlt">sheet</span>, the magnetic field elevation, the ion bulk speed, and the ion temperature all show marked rises during the substorm expansion phase. Somewhat less pronounced increases of all three parameters are found in the <span class="hlt">plasma</span> <span class="hlt">sheet</span> boundary layer. But here the substorm effects are typically seen during the recovery phase. In the near-Earth neutral line substorm model, the latter finding would indicate that the recovery phase begins when reconnection has proceeded to <span class="hlt">plasma</span> <span class="hlt">sheet</span> boundary layer field lines. Since the temporal evolution of ion temperature and ion density are anticorrelated especially in the central <span class="hlt">plasma</span> <span class="hlt">sheet</span>, the authors argue that the strong <span class="hlt">plasma</span> heating during substorms occurs in a nonadiabatic fashion.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/25526132','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/25526132"><span id="translatedtitle">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="http://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>2014-12-01</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. PMID:25526132</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/5102573','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/5102573"><span id="translatedtitle">Average electric wave spectra in the <span class="hlt">plasma</span> <span class="hlt">sheet</span>: Dependence on ion density and ion beta</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Baumjohann, W.; Treumann, R.A. ); LaBelle, J. )</p> <p>1990-04-01</p> <p>Using 4 months of tail data obtained by the ELF/MF spectrum analyzer and the <span class="hlt">plasma</span> instrument on board the AMPTE/IRM satellite, more than 50,000 ten-second-averaged electric wave spectra were analyzed in order to establish typical spectra for periods of high and low ion density and high and low ion {beta}. The general spectral slope of the spectra in the <span class="hlt">plasma</span> <span class="hlt">sheet</span> follows an f{sup {minus}2} law. Ion {beta} has a stronger influence on the spectral form than the ion density. Highest average spectral densities are obtained in the low-{beta} <span class="hlt">plasma</span> <span class="hlt">sheet</span> boundary layer, where the spectrum is that of broadband electrostatic noise extending to frequencies near and above the upper hybrid frequency. Lowest wave intensities are encountered in the high-{beta} inner central <span class="hlt">plasma</span> <span class="hlt">sheet</span>. The outer central <span class="hlt">plasma</span> <span class="hlt">sheet</span> has generally low wave intensities and is dominated by <span class="hlt">electron</span> cyclotron odd half-harmonics and <span class="hlt">electron</span> regions of the <span class="hlt">plasma</span> <span class="hlt">sheet</span> while higher odd half-harmonics dominate the low-{beta} and low-density inner central <span class="hlt">plasma</span> <span class="hlt">sheet</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/22299938','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/22299938"><span id="translatedtitle">Early results of microwave transmission experiments through an overly dense rectangular <span class="hlt">plasma</span> <span class="hlt">sheet</span> with microparticle injection</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Gillman, Eric D.; Amatucci, W. E.</p> <p>2014-06-15</p> <p>These experiments utilize a linear hollow cathode to create a dense, rectangular <span class="hlt">plasma</span> <span class="hlt">sheet</span> to simulate the <span class="hlt">plasma</span> layer surrounding vehicles traveling at hypersonic velocities within the Earth's atmosphere. Injection of fine dielectric microparticles significantly reduces the <span class="hlt">electron</span> density and therefore lowers the <span class="hlt">electron</span> <span class="hlt">plasma</span> frequency by binding a significant portion of the bulk free <span class="hlt">electrons</span> to the relatively massive microparticles. Measurements show that microwave transmission through this previously overly dense, impenetrable <span class="hlt">plasma</span> layer increases with the injection of alumina microparticles approximately 60 ?m in diameter. This method of <span class="hlt">electron</span> depletion is a potential means of mitigating the radio communications blackout experienced by hypersonic vehicles.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/19518640','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/19518640"><span id="translatedtitle">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="http://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>. PMID:19518640</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/21180385','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/21180385"><span id="translatedtitle">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="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Ergun, R. E.; Tao, J.; Andersson, L.; Eriksson, S.; Johansson, T.; Angelopoulos, V.; Bonnell, J.; McFadden, J. P.; Larson, D. E.; 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{sub 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{sub 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('http://ntrs.nasa.gov/search.jsp?R=19900063368&hterms=Uranus&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D90%26Ntt%3DUranus','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19900063368&hterms=Uranus&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D90%26Ntt%3DUranus"><span id="translatedtitle">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://hdl.handle.net/2060/20000023162','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20000023162"><span id="translatedtitle"><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('http://www.osti.gov/scitech/biblio/51801','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/51801"><span id="translatedtitle">XUV laser-produced <span class="hlt">plasma</span> <span class="hlt">sheet</span> beam and microwave agile mirror</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Shen, W.; Scharer, J.E.; Porter, B.; Lam, N.T.</p> <p>1994-12-31</p> <p>An excimer-laser ({lambda} = 193 nm) produced <span class="hlt">plasma</span> in an organic gas (TMAE) has been generated and studied. These studies have determined the ion-<span class="hlt">electron</span> recombination coefficient and the photon absorption cross-section, of the neutral gas. The dependences of wave transmission, reflection and absorption on <span class="hlt">plasma</span> density are obtained. A new optical system with an array of cylindrical XUV coated lenses has been implemented to form a <span class="hlt">plasma</span> <span class="hlt">sheet</span> to study its usage as agile mirror microwave reflector. The lens system expands the incident laser beam in X direction and compresses it in Y direction to form a <span class="hlt">sheet</span> beam. The expanded beam then passes through a vacuum chamber filled with TMAE at 50--500 nTorr to produce the <span class="hlt">plasma</span> <span class="hlt">sheet</span>. Space-time measurements of the <span class="hlt">plasma</span> density and temperature as measured by a Langmuir probe are presented. XUV optical measurements of the laser beam as measured by a photodiode are presented. Initial experiments have generated a <span class="hlt">plasma</span> <span class="hlt">sheet</span> of 5--10 mm x 11 cm with peak <span class="hlt">plasma</span> density of 5 {times} 10{sup 13} cm{sup {minus}3}. A microwave source will be utilized to study the agile mirror character of the <span class="hlt">plasma</span> <span class="hlt">sheet</span>. Modeling of the microwave reflection from the <span class="hlt">plasma</span> profile will also be discussed.</p> </li> <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 id="translatedtitle">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/2015GeoRL..42.7867F','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015GeoRL..42.7867F"><span id="translatedtitle">Imaging the development of the cold dense <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>Fuselier, S. A.; Dayeh, M. A.; Livadiotis, G.; McComas, D. J.; Ogasawara, K.; Valek, P.; Funsten, H. O.; Petrinec, S. M.</p> <p>2015-10-01</p> <p>The Interstellar Boundary Explorer (IBEX) frequently images the Earth's magnetosphere in Energetic Neutral Atoms (ENAs). In May 2013, there was an extended period of northward interplanetary magnetic field (IMF) while IBEX was imaging the Earth's magnetotail. During this period, IBEX imaged the development of the cold <span class="hlt">plasma</span> <span class="hlt">sheet</span> between about 15 and 20 Earth radii (RE) down the tail from the Earth. The ENA fluxes changed in both amplitude and average energy during this development. In addition, the <span class="hlt">plasma</span> <span class="hlt">sheet</span> may have thickened. At the end of the interval, the IMF turned southward and ENA fluxes decreased. The thickening of the <span class="hlt">plasma</span> <span class="hlt">sheet</span> suggests that the <span class="hlt">plasma</span> in this region increases in both density and volume as it develops during extended periods of northward IMF. The decrease in the ENA flux suggests thinning of the <span class="hlt">plasma</span> <span class="hlt">sheet</span> and loss of <span class="hlt">plasma</span> associated with the IMF turning.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2011EOSTr..92R.140T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011EOSTr..92R.140T"><span id="translatedtitle">Research Spotlight: First images of 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>Tretkoff, Ernie</p> <p>2011-04-01</p> <p>New images from the Interstellar Boundary Explorer (IBEX) mission capture for the first time part of Earth's magnetosphere. The new observations, described by McComas et al., provide the first images of the extended terrestrial <span class="hlt">plasma</span> <span class="hlt">sheet</span>, the <span class="hlt">sheet</span> separating the north and south lobes of the magnetosphere. The <span class="hlt">plasma</span> <span class="hlt">sheet</span> cannot be seen in images in visible light; the IBEX images were created using detections of energetic neutral atoms. One of the images captured what appears to be a magnetic disconnection event, in which magnetic field lines tear and part of the <span class="hlt">plasma</span> <span class="hlt">sheet</span> pinches off from the rest. These types of disconnections release energy and can cause charged particles to be accelerated toward Earth, potentially disrupting satellites. This is the first time that a <span class="hlt">plasma</span> <span class="hlt">sheet</span> disconnection event may have been directly seen. (Journal of Geophysical Research-Space Physics, doi:10.1029/2010JA016138, 2011)</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 id="translatedtitle">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://adsabs.harvard.edu/abs/2003EAEJA.....5006R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2003EAEJA.....5006R"><span id="translatedtitle">Current <span class="hlt">sheet</span> bifurcations observed by Cluster during <span class="hlt">plasma</span> <span class="hlt">sheet</span> flapping</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Runov, A.; Sergeev, V.; Baumjohann, W.; Nakamura, R.; Balogh, A.; Klecker, B.; Reme, H.; Sauvaud, J.-A.; Andre, M.</p> <p>2003-04-01</p> <p>We examined the structure of the tail current <span class="hlt">sheet</span> at XGSM˜-19~R_E using fast flapping oscillation. It was found that during 1055 -1107 UT on 29 August 2001 and 2220 - 2235 UT on 26 September 2001, following substorm intensifications, the flapping current <span class="hlt">sheet</span> displayed a clearly bifurcated structure with current density peaks at |B_x|˜0.5~B_L and a pronounced broad current density minimum in between. In both cases the bifurcation was associated with the current <span class="hlt">sheet</span> flapping in the Y-Z plane, with very large tilts (exceeding 45o). The origins of current bifurcation and of severe flapping motions are discussed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013EPSC....8..811S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013EPSC....8..811S"><span id="translatedtitle">Chasing the center of the Saturnian <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>Sergis, N.; Jackman, C. M.; Arridge, C. S.; Krimigis, S. M.; Hamilton, D. C.; Mitchell, D. G.; Krupp, N.; Dougherty, M. K.</p> <p>2013-09-01</p> <p>After 9 years in orbit around Saturn, Cassini has collected an enormous amount of in-situ and remote measurements, covering a significant part of the giant planet's magnetosphere, during different seasonal conditions. In this study we use particle and magnetic field data to provide a statistical approach to the average conditions of the Saturnian <span class="hlt">plasma</span> <span class="hlt">sheet</span>. In contrast to previous works, we determine <span class="hlt">plasma</span> <span class="hlt">sheet</span> intervals based on criteria incorporating the radial components of the magnetic field Br and the field root mean square (RMS), rather than the distance from the rotational equatorial plane that we now know that does not follow the <span class="hlt">plasma</span> <span class="hlt">sheet</span> as closely. This way, we minimize (as possible) effects related to the well monitored seasonal or periodic (short scale) displacement of the <span class="hlt">plasma</span> <span class="hlt">sheet</span> that is usually compared to the scale heights for most of the particle populations therein, we produce particle property maps (such as particle pressure and beta, spectral index, pressure gradient etc) that describe for the first time the actual center region of the Saturnian <span class="hlt">plasma</span> <span class="hlt">sheet</span> and we further compare pre to post-equinox behavior. Our final outcome will be in the form of long term statistical grid maps that follow the center region of the <span class="hlt">plasma</span> <span class="hlt">sheet</span> and reveal in what degree the measured dynamics should be attributed to local particle dynamics or to the motion of the <span class="hlt">plasma</span> <span class="hlt">sheet</span> as a structure. In addition, the accurate determination of the <span class="hlt">plasma</span> <span class="hlt">sheet</span> using essentially all date available since Saturn Orbit Insertion (SOI) in 2004, will give us the opportunity of looking closer into features that are still insufficiently explained, such as the systematic local time asymmetry observed in the particle energization or the radial <span class="hlt">plasma</span> and energy transport, and provide a global, season-independed, magnetospheric map for Saturn.</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('http://www.ncbi.nlm.nih.gov/pubmed/12686993','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/12686993"><span id="translatedtitle">Cold ions in the hot <span class="hlt">plasma</span> <span class="hlt">sheet</span> of Earth's magnetotail.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Seki, Kanako; Hirahara, Masafumi; Hoshino, Masahiro; Terasawa, Toshio; Elphic, Richard C; Saito, Yoshifumi; Mukai, Toshifumi; Hayakawa, Hajime; Kojima, Hirotsugu; Matsumoto, Hiroshi</p> <p>2003-04-10</p> <p>Most visible matter in the Universe exists as <span class="hlt">plasma</span>. How this <span class="hlt">plasma</span> is heated, and especially how the initial non-equilibrium <span class="hlt">plasma</span> distributions relax to thermal equilibrium (as predicted by Maxwell-Boltzman statistics), is a fundamental question in studies of astrophysical and laboratory <span class="hlt">plasmas</span>. Astrophysical <span class="hlt">plasmas</span> are often so tenuous that binary collisions can be ignored, and it is not clear how thermal equilibrium develops for these 'collisionless' <span class="hlt">plasmas</span>. One example of a collisionless <span class="hlt">plasma</span> is the Earth's <span class="hlt">plasma</span> <span class="hlt">sheet</span>, where thermalized hot <span class="hlt">plasma</span> with ion temperatures of about 5 x 10(7) K has been observed. Here we report direct observations of a <span class="hlt">plasma</span> distribution function during a solar eclipse, revealing cold ions in the Earth's <span class="hlt">plasma</span> <span class="hlt">sheet</span> in coexistence with thermalized hot ions. This cold component cannot be detected by <span class="hlt">plasma</span> sensors on satellites that are positively charged in sunlight, but our observations in the Earth's shadow show that the density of the cold ions is comparable to that of hot ions. This high density is difficult to explain within existing theories, as it requires a mechanism that permits half of the source <span class="hlt">plasma</span> to remain cold upon entry into the hot turbulent <span class="hlt">plasma</span> <span class="hlt">sheet</span>. PMID:12686993</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015EP%26S...67..133S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015EP%26S...67..133S"><span id="translatedtitle">On the <span class="hlt">plasma</span> <span class="hlt">sheet</span> dependence on solar wind and substorms and its role in magnetosphere-ionosphere coupling</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Sergeev, V. A.; Dmitrieva, N. P.; Stepanov, N. A.; Sormakov, D. A.; Angelopoulos, V.; Runov, A. V.</p> <p>2015-12-01</p> <p>Recently, it was argued that Hall conductivity and peak intensity of equivalent ionospheric currents are sensitive to the amount of field-aligned acceleration of <span class="hlt">plasma</span> <span class="hlt">sheet</span> (PS) <span class="hlt">electrons</span>, which in turn depends on the <span class="hlt">plasma</span> <span class="hlt">sheet</span> parameters T e and N e (<span class="hlt">electron</span> temperature and density) proportionally to the quantity eTN = ( T e)1/2/ N e. Here we extend these studies using data from six tail seasons of THEMIS observations to show statistically that the behavior of these PS <span class="hlt">electron</span> parameters, measured in the middle of the nightside <span class="hlt">plasma</span> <span class="hlt">sheet</span> at ~10 RE distance, depends in a very different way on two basic processes: the solar wind state and substorms. We confirm previous work that slow/dense (fast/tenuous) solar wind provides cold/dense (hot/tenuous) <span class="hlt">plasma</span> <span class="hlt">sheet</span> conditions. However, we find that <span class="hlt">electron</span> temperature and pressure parameters ( T e and P e) behave differently from the proton ones ( T p and P p), indicating a strong decoupling between temperature variations of auroral protons and <span class="hlt">electrons</span> in the central <span class="hlt">plasma</span> <span class="hlt">sheet</span> (CPS): <span class="hlt">electrons</span> are more sensitive to the substorm-related acceleration in the magnetotail than protons. Our superposed epoch study of <span class="hlt">plasma</span> <span class="hlt">sheet</span> parameter variations during substorms as well as our analysis of <span class="hlt">plasma</span> acceleration at dipolarization fronts shows that during the substorm expansion phase a new (accelerated and <span class="hlt">plasma</span>-depleted) population comes into the inner CPS with the flow bursts, showing an average increase of <span class="hlt">electron</span> temperature and eTN parameter roughly by a factor of 2 above its background values for both cold/dense and hot/tenuous <span class="hlt">plasma</span> <span class="hlt">sheet</span> states. Preferential <span class="hlt">electron</span> heating in the flow bursts is also statistically confirmed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://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="http://ntrs.nasa.gov/search.jsp?R=19900029440&hterms=IRM&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D60%26Ntt%3DIRM"><span id="translatedtitle">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/2014JPhD...47L5501T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014JPhD...47L5501T"><span id="translatedtitle">Microwave <span class="hlt">plasmas</span> applied for the synthesis of free standing graphene <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>Tatarova, E.; Dias, A.; Henriques, J.; Botelho do Rego, A. M.; Ferraria, A. M.; Abrashev, M. V.; Luhrs, C. C.; Phillips, J.; Dias, F. M.; Ferreira, C. M.</p> <p>2014-09-01</p> <p>Self-standing graphene <span class="hlt">sheets</span> were synthesized using microwave <span class="hlt">plasmas</span> driven by surface waves at 2.45 GHz stimulating frequency and atmospheric pressure. The method is based on injecting ethanol molecules through a microwave argon <span class="hlt">plasma</span> environment, where decomposition of ethanol molecules takes place. The evolution of the ethanol decomposition was studied in situ by <span class="hlt">plasma</span> emission spectroscopy. Free gas-phase carbon atoms created in the <span class="hlt">plasma</span> diffuse into colder zones, both in radial and axial directions, and aggregate into solid carbon nuclei. The main part of the solid carbon is gradually withdrawn from the hot region of the <span class="hlt">plasma</span> in the outlet <span class="hlt">plasma</span> stream where nanostructures assemble and grow. Externally forced heating in the assembly zone of the <span class="hlt">plasma</span> reactor has been applied to engineer the structural qualities of the assembled nanostructures. The synthesized graphene <span class="hlt">sheets</span> have been analysed by Raman spectroscopy, scanning <span class="hlt">electron</span> microscopy, high-resolution transmission <span class="hlt">electron</span> microscopy and x-ray photoelectron spectroscopy. The presence of sp3 carbons is reduced by increasing the gas temperature in the assembly zone of the <span class="hlt">plasma</span> reactor. As a general trend, the number of mono-layers decreases when the wall temperature increases from 60 to 100 °C. The synthesized graphene <span class="hlt">sheets</span> are stable and highly ordered.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www-pw.physics.uiowa.edu/~dag/publications/2007_VerticalSheetsOfDensePlasmaInTheTopsideMartianIonosphere_JGR.pdf','EPRINT'); return false;" href="http://www-pw.physics.uiowa.edu/~dag/publications/2007_VerticalSheetsOfDensePlasmaInTheTopsideMartianIonosphere_JGR.pdf"><span id="translatedtitle">Vertical <span class="hlt">sheets</span> of dense <span class="hlt">plasma</span> in the topside Martian ionosphere E. Nielsen,1</span></a></p> <p><a target="_blank" href="http://www.osti.gov/eprints/">E-print Network</a></p> <p>Gurnett, Donald A.</p> <p></p> <p>Vertical <span class="hlt">sheets</span> of dense <span class="hlt">plasma</span> in the topside Martian ionosphere E. Nielsen,1 X.-D. Wang,1 D. A-frequency radar, Mars Advanced Radar for Subsurface and Ionosphere Sounding (MARSIS), on board the Mars Express spacecraft is used to sound <span class="hlt">electron</span> densities in the topside Martian ionosphere. The radar records the delay</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2008GeoRL..3517S13G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2008GeoRL..3517S13G"><span id="translatedtitle">Propagation characteristics of <span class="hlt">plasma</span> <span class="hlt">sheet</span> oscillations during a small storm</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Gabrielse, C.; Angelopoulos, V.; Runov, A.; Kepko, L.; Glassmeier, K. H.; Auster, H. U.; McFadden, J.; Carlson, C. W.; Larson, D.</p> <p>2008-06-01</p> <p>On 24 March 2007, the THEMIS spacecraft were in a string-of-pearls configuration through the dusk <span class="hlt">plasma</span> <span class="hlt">sheet</span> at the recovery phase of a small storm. Large undulations of the <span class="hlt">plasma</span> <span class="hlt">sheet</span> were observed that brought the five probes from one lobe to another. Each neutral <span class="hlt">sheet</span> crossing was accompanied by bursty bulk flows and Pi2 oscillations. In this paper we focus on the low frequency (~10 min) large scale <span class="hlt">plasma</span> <span class="hlt">sheet</span> undulations and determine their propagation characteristics, origin, and properties in the presence of storm-time substorms. As the first case of ``flapping waves'' observed and analyzed during storm-time, it is interesting to find their characteristics coincide with those described by previous quiet-time observations. These characteristics include flankward propagation of the undulations with velocities generally between ~40-130 km/s.</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 id="translatedtitle">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://ntrs.nasa.gov/search.jsp?R=19920045462&hterms=McCarthy&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D60%26Ntt%3DMcCarthy%252C%2BR','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19920045462&hterms=McCarthy&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D60%26Ntt%3DMcCarthy%252C%2BR"><span id="translatedtitle">Low-energy particle layer outside of the <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.; Fitzenreiter, R.; Ogilvie, K. W.; Huang, C.; Anderson, K. A.; Dandouras, J.; Frank, L.; Lin, R. P.; Mccarthy, M.; Reme, H.</p> <p>1992-01-01</p> <p>The ISEE spacecraft in the geomagnetic tail frequently crossed the high-latitude boundary of the <span class="hlt">plasma</span> <span class="hlt">sheet</span>. On a number of these crossings on the morningside (between 15 RE and 22 RE) the ISEE instruments detected an enhanced population of low-energy <span class="hlt">electrons</span> and ions immediately adjacent to the <span class="hlt">plasma</span> <span class="hlt">sheet</span> boundary layer (PSBL). The <span class="hlt">electrons</span> in this low-energy layer (LEL) have energies less than a few hundred eV, and they are aligned along the magnetic field direction propagating in the tailward direction. The ions have energies less than 100 eV and are also streaming along the magnetic field direction but in the earthward direction. These particles are clearly distinguished from the bulk of the particles in the <span class="hlt">plasma</span> <span class="hlt">sheet</span> and the PSBL. These observations may help clarify where the various particle features in the geomagnetic tail map to in the ionosphere. It is suggested that the LEL maps to the soft (less than 1 keV) <span class="hlt">electron</span> precipitation region poleward of the <span class="hlt">plasma</span> <span class="hlt">sheet</span> boundary.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19900043492&hterms=Earth+layers&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D60%26Ntt%3DEarth%2527s%2Blayers','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19900043492&hterms=Earth+layers&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D60%26Ntt%3DEarth%2527s%2Blayers"><span id="translatedtitle">Cold <span class="hlt">plasma</span> heating in the <span class="hlt">plasma</span> <span class="hlt">sheet</span> boundary layer - Theory and simulations</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Schriver, David; Ashour-Abdalla, Maha</p> <p>1990-01-01</p> <p>Satellite observations in recent years have confirmed that the <span class="hlt">plasma</span> <span class="hlt">sheet</span> boundary layer is a permanent feature of the earth's magnetotail located between the lobe and central <span class="hlt">plasma</span> <span class="hlt">sheet</span> during both quiet and active magnetic periods. Distinct features of the boundary layer include field aligned ion beams and intense electrostatic emissions known as broadband electrostatic noise. Since the <span class="hlt">plasma</span> <span class="hlt">sheet</span> boundary layer is a spatial feature of the magnetotail, within it will occur thermal mixing of the resident warm boundary layer <span class="hlt">plasma</span> with inflowing (convecting) cold ionospheric <span class="hlt">plasma</span>. A theoretical study involving linear theory and nonlinear numerical particle simulations is presented which examines ion beam instabilities in the presence of a thermally mixed hot and cold background <span class="hlt">plasma</span>. It is found that the free energy in the ion beams can heat the cool ionospheric <span class="hlt">plasma</span> to ambient <span class="hlt">plasma</span> <span class="hlt">sheet</span> boundary layer temperatures via broadband electrostatic noise. These results, along with recent observational reports that ionospheric outflow can account for measured <span class="hlt">plasma</span> <span class="hlt">sheet</span> densities, suggest that the ionospheric role in <span class="hlt">plasma</span> <span class="hlt">sheet</span> dynamics and content may be as large as the solar wind.</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 id="translatedtitle"><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://hdl.handle.net/2060/19830024324','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19830024324"><span id="translatedtitle">The inner edge of the <span class="hlt">plasma</span> <span class="hlt">sheet</span> and the diffuse aurora</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.; Vinas, A. F.</p> <p>1983-01-01</p> <p>Three dimensional measurements from the ISEE-1 low energy <span class="hlt">electron</span> spectrometer are used to map the location of the inner edge of the <span class="hlt">plasma</span> <span class="hlt">sheet</span> and study the anisotropies in the <span class="hlt">electron</span> distribution function associated with this boundary. Lower energy <span class="hlt">plasma</span> <span class="hlt">sheet</span> <span class="hlt">electrons</span> have inner edges closer to the Earth than higher energies with the separations at different energies being larger near dawn and after dusk than at midnight. Lowest energy inner edges are frequently located adjacent to the plasmapause in the dawn hemisphere but are often separated from it in the dusk hemisphere by a gap of at least several Re. The energy dispersion is minimal in the afternoon quadrant where the inner edge is near the magnetopause and frequently oscillating on a time scale of minutes. The location of the inner edge is probably determined primarily by the motion of <span class="hlt">electrons</span> in the existing electric and magnetic fields rather than by strong diffusion as has sometimes been supposed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19840027172','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19840027172"><span id="translatedtitle"><span class="hlt">Plasma</span> <span class="hlt">electron</span> analysis: Voyager <span class="hlt">plasma</span> science experiment</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.</p> <p>1983-01-01</p> <p>The <span class="hlt">Plasma</span> Science Experiment (PLS) on the Voyager spacecraft provide data on the <span class="hlt">plasma</span> ions and <span class="hlt">electrons</span> in the interplanetary medium and the magnetospheres of the giant planets Jupiter and Saturn. A description of the analysis used to obtain <span class="hlt">electron</span> parameters (density, temperature, etc.) from the <span class="hlt">plasma</span> science experiment PLS <span class="hlt">electron</span> measurements which cover the energy range from 10 eV to 5950 eV is presented. The <span class="hlt">electron</span> sensor (D cup) and its transmission characteristics are described. A derivation of the fundamental analytical expression of the reduced distribution function F(e) is given. The <span class="hlt">electron</span> distribution function F(e), used in the moment integrations, can be derived from F(e). Positive ions produce a correction current (ion feedthrough) to the measured <span class="hlt">electron</span> current, which can be important to the measurements of the suprathermal <span class="hlt">electron</span> component. In the case of Saturn, this correction current, which can either add to or subtract from the measured <span class="hlt">electron</span> current, is less than 20% of the measured signal at all times. Comments about the corrections introduced by spacecraft charging to the Saturn encounter data, which can be important in regions of high density and shadow when the spacecraft can become negatively charged are introduced.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015EGUGA..17.6497P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015EGUGA..17.6497P"><span id="translatedtitle"><span class="hlt">Plasma</span> <span class="hlt">sheet</span> flow damping by oscillatory flow braking</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Panov, Evgeny V.; Leontyeva, Olga S.; Baumjohann, Wolfgang; Nakamura, Rumi; Amm, Olaf; Angelopoulos, Vassilis; Glassmeier, Karl-Heinz; Kubyshkina, Marina V.; Petrukovich, Anatoli A.; Sergeev, Victor A.; Weygand, James M.</p> <p>2015-04-01</p> <p>Using simultaneous observations in the near-Earth <span class="hlt">plasma</span> <span class="hlt">sheet</span> by five Time History of Events and Macroscale Interactions during Substorms (THEMIS) probes, conjugate ground all-sky camera observations from Canada, and magnetometer networks over North America, we show that auroral bulge dynamics is modulated by a recently discovered process known as oscillatory flow braking, which occurs at about 10 Earth radii down the Earth's magnetotail. In oscillatory flow breaking, <span class="hlt">plasma</span> <span class="hlt">sheet</span> flows oscillating with different periods at various distances collide, producing pressure forces that exert shear stresses on the magnetic field, transiently amplifying the vertical magnetic field component. Sporadic fast relief of these stresses through significant particle precipitations causes damping of <span class="hlt">plasma</span> <span class="hlt">sheet</span> fast flows.</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 id="translatedtitle">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('http://ntrs.nasa.gov/search.jsp?R=19910063755&hterms=Chaos&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D90%26Ntt%3DChaos','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19910063755&hterms=Chaos&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D90%26Ntt%3DChaos"><span id="translatedtitle">Chaos in the <span class="hlt">plasma</span> <span class="hlt">sheet</span>. [of geomagnetic tail</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Goertz, Christoph K.; Smith, Robert A.; Shan, Lin-Hua</p> <p>1991-01-01</p> <p>A simple dynamical model of the magnetotail is discussed, in which the electric field in the current <span class="hlt">sheet</span> evolves in response to a solar-wind-induced electric field at the magnetopause, and depends on the specific entropy of the <span class="hlt">plasma</span> in the <span class="hlt">plasma</span> <span class="hlt">sheet</span>. The entropy varies due to nonadiabatic heating in a region where ULF waves are absorbed by resonant mode conversion. The feedback between temperature and entropy change leads to an evolution which exhibits chaos when the solar wind electric field is neither very small nor very large. The onset of chaos may be quite sudden or may proceed through a sequence of period doublings.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015HEDP...17..208K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015HEDP...17..208K"><span id="translatedtitle">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://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Keiter, P. A.; Malamud, G.; Trantham, M.; Fein, J.; Davis, J.; Klein, S. R.; Drake, R. P.</p> <p>2015-12-01</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 [Krauland et al. 2013], 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. 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('http://ntrs.nasa.gov/search.jsp?R=19950029531&hterms=journal+physique&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D60%26Ntt%3Djournal%2Bphysique','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19950029531&hterms=journal+physique&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D60%26Ntt%3Djournal%2Bphysique"><span id="translatedtitle">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://space.unh.edu/~rlk/research/reprints/jgr_116_A08206_2011.pdf','EPRINT'); return false;" href="http://space.unh.edu/~rlk/research/reprints/jgr_116_A08206_2011.pdf"><span id="translatedtitle">Entropy distribution in the <span class="hlt">plasma</span> <span class="hlt">sheet</span> Richard L. Kaufmann1</span></a></p> <p><a target="_blank" href="http://www.osti.gov/eprints/">E-print Network</a></p> <p>Kaufmann, Richard L.</p> <p></p> <p>Entropy distribution in the <span class="hlt">plasma</span> <span class="hlt">sheet</span> Richard L. Kaufmann1 and William R. Paterson2 Received 12 used to study the longterm averaged spatial and flow speed dependencies of the ion entropy per unit volume and per unit flux tube and the average entropy per ion. It was concluded that some process</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 id="translatedtitle">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> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19890056327&hterms=electron&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DTitle%26N%3D0%26No%3D40%26Ntt%3Delectron','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19890056327&hterms=electron&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DTitle%26N%3D0%26No%3D40%26Ntt%3Delectron"><span id="translatedtitle"><span class="hlt">Electron</span> velocity distributions and <span class="hlt">plasma</span> waves associated with the injection of an <span class="hlt">electron</span> beam 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>Frank, L. A.; Paterson, W. R.; Kurth, W. S.; Ashour-Abdalla, M.; Schriver, D.</p> <p>1989-01-01</p> <p>An <span class="hlt">electron</span> beam was injected into earth's ionosphere on August 1, 1985, during the flight of the Space Shuttle Challenger as part of the objectives of the Spacelab 2 mission. In the wake of the Space Shuttle a magnetically aligned <span class="hlt">sheet</span> of <span class="hlt">electrons</span> returning from the direction of propagation of the beam was detected with the free-flying <span class="hlt">Plasma</span> Diagnostics Package. The thickness of this <span class="hlt">sheet</span> of returning <span class="hlt">electrons</span> was about 20 m. Large intensifications of broadband electrostatic noise were also observed within this <span class="hlt">sheet</span> of <span class="hlt">electrons</span>. A numerical simulation of the interaction of the <span class="hlt">electron</span> beam with the ambient ionospheric <span class="hlt">plasmas</span> is employed to show that the <span class="hlt">electron</span> beam excites <span class="hlt">electron</span> <span class="hlt">plasma</span> oscillations and that it is possible for the ion acoustic instability to provide a returning flux of hot <span class="hlt">electrons</span> by means of quasi-linear diffusion.</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://www.osti.gov/scitech/biblio/22251923','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/22251923"><span id="translatedtitle">Kinetic theory of the <span class="hlt">electron</span> bounce instability in two dimensional current <span class="hlt">sheets</span>—Full electromagnetic treatment</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Tur, A.; Fruit, G.; Louarn, P.</p> <p>2014-03-15</p> <p>In the general context of understanding the possible destabilization of a current <span class="hlt">sheet</span> with applications to magnetospheric substorms or solar flares, a kinetic model is proposed for studying the resonant interaction between electromagnetic fluctuations and trapped bouncing <span class="hlt">electrons</span> in a 2D current <span class="hlt">sheet</span>. Tur et al. [A. Tur et al., Phys. <span class="hlt">Plasmas</span> 17, 102905 (2010)] and Fruit et al. [G. Fruit et al., Phys. <span class="hlt">Plasmas</span> 20, 022113 (2013)] already used this model to investigate the possibilities of electrostatic instabilities. Here, the model is completed 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. 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 quasineutrality condition and the Ampere's law for the current density. It is found that for mildly strechted current, 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> half 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{sub z}/B{sub lobes}, the mode becomes explosive with typical growth rate of a few tens of seconds. The free energy contained in the bouncing motion of the <span class="hlt">electrons</span> may trigger an electromagnetic instability able to disrupt the cross-tail current in a few seconds. This new instability–electromagnetic <span class="hlt">electron</span>-bounce instability–may explain fast and global scale destabilization of current <span class="hlt">sheets</span> as required to describe substorm phenomena.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014PhPl...21c2113T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014PhPl...21c2113T"><span id="translatedtitle">Kinetic theory of the <span class="hlt">electron</span> bounce instability in two dimensional current <span class="hlt">sheets</span>-Full electromagnetic treatment</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Tur, A.; Fruit, G.; Louarn, P.; Yanovsky, V.</p> <p>2014-03-01</p> <p>In the general context of understanding the possible destabilization of a current <span class="hlt">sheet</span> with applications to magnetospheric substorms or solar flares, a kinetic model is proposed for studying the resonant interaction between electromagnetic fluctuations and trapped bouncing <span class="hlt">electrons</span> in a 2D current <span class="hlt">sheet</span>. Tur et al. [A. Tur et al., Phys. <span class="hlt">Plasmas</span> 17, 102905 (2010)] and Fruit et al. [G. Fruit et al., Phys. <span class="hlt">Plasmas</span> 20, 022113 (2013)] already used this model to investigate the possibilities of electrostatic instabilities. Here, the model is completed 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. 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 quasineutrality condition and the Ampere's law for the current density. It is found that for mildly strechted current, 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> half 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 ? = Bz/Blobes, the mode becomes explosive with typical growth rate of a few tens of seconds. The free energy contained in the bouncing motion of the <span class="hlt">electrons</span> may trigger an electromagnetic instability able to disrupt the cross-tail current in a few seconds. This new instability-electromagnetic <span class="hlt">electron</span>-bounce instability-may explain fast and global scale destabilization of current <span class="hlt">sheets</span> as required to describe substorm phenomena.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014AGUFMSM53A..08S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014AGUFMSM53A..08S"><span id="translatedtitle">Investigation of solar wind dependence of the <span class="hlt">plasma</span> <span class="hlt">sheet</span> based on long-term Geotail/LEP data evaluation</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Saeki, R.; Seki, K.; Saito, Y.; Shinohara, I.; Miyashita, Y.; Imada, S.; Machida, S.</p> <p>2014-12-01</p> <p>It is observationally known that the <span class="hlt">plasma</span> density and temperature in <span class="hlt">plasma</span> <span class="hlt">sheet</span> are significantly changed by solar wind conditions [e.g., Terasawa et al., 1997]. Thus it is considered that the <span class="hlt">plasma</span> <span class="hlt">sheet</span> <span class="hlt">plasma</span> is originated from the solar wind, and several entry mechanisms have been suggested. When the interplanetary magnetic field (IMF) is southward, the solar wind <span class="hlt">plasma</span> enters the <span class="hlt">plasma</span> <span class="hlt">sheet</span> mainly through magnetic reconnection at the dayside magnetopause. In contrast, for the northward IMF, the double-lobe reconnection [Song et al., 1999], abnormal diffusion [Johnson and Cheng., 1997], and <span class="hlt">plasma</span> mixing through the Kelvin-Helmholtz instability caused by viscous interaction [Hasegawa et al., 2004] have been proposed. Relative contribution of each process is, however, far from understood. In the present study, we use magnetotail observations by the Geotail spacecraft at radial distances of 10-32 Re during 12-year period from 1995 to 2006 to investigate properties of the <span class="hlt">plasma</span> <span class="hlt">sheet</span>. We conducted a statistical analysis with calibrated LEP-EA [Mukai et al., 1994] ion and <span class="hlt">electron</span> data. We selected central <span class="hlt">plasma</span> <span class="hlt">sheet</span> observations and derived <span class="hlt">electron</span> and ion temperature and density using the same method and criteria as Terasawa et al. [1997]. In addition, OMNI solar-wind data are used. The results show that the <span class="hlt">plasma</span> <span class="hlt">sheet</span> density (both ion and <span class="hlt">electron</span> temperatures) has a good correlation with the solar wind density (kinetic energy) over the whole solar cycle. We find clear dawn-dusk asymmetry in the temperature ratio Ti/Te, i.e., the average Ti/Te is higher on the duskside than the dawn. The density also shows the dawn-dusk asymmetry and higher on the duskside than on the dawnside. A previous study by Wang et al. [2012] showed that Ti/Te is high (typically 5-10) in the magnetosheath. The statistical results, therefore, suggest that the shocked solar wind <span class="hlt">plasma</span> can easily enter the duskside <span class="hlt">plasma</span> <span class="hlt">sheet</span> rather than the dawnside. We will discuss the possible mechanisms of the entry of the cold <span class="hlt">plasma</span> into the duskside <span class="hlt">plasma</span> <span class="hlt">sheet</span>.</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 id="translatedtitle">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('http://adsabs.harvard.edu/abs/1980STIN...8033325S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1980STIN...8033325S"><span id="translatedtitle">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://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Scudder, J. D.; Sittler, E. C., Jr.; Bridge, H. S.</p> <p>1980-08-01</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('http://adsabs.harvard.edu/abs/2015PhPl...22j2110J','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015PhPl...22j2110J"><span id="translatedtitle">Evolution of <span class="hlt">electron</span> current <span class="hlt">sheets</span> in collisionless magnetic reconnection</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Jain, Neeraj; Sharma, A. Surjalal</p> <p>2015-10-01</p> <p>An <span class="hlt">electron</span> current <span class="hlt">sheet</span> embedded in an ion scale current <span class="hlt">sheet</span> is an inherent feature of collisionless magnetic reconnection. Such thin <span class="hlt">electron</span> current <span class="hlt">sheets</span> are unstable to tearing mode and produce secondary magnetic islands modulating the reconnection rate. In this work, 2-D evolution of tearing mode at multiple reconnection sites in an <span class="hlt">electron</span> current <span class="hlt">sheet</span> is studied using <span class="hlt">electron</span>-magnetohydrodynamic (EMHD) model. It is shown that growth of the perturbations can make reconnection impulsive by suddenly enhancing the reconnection rate and also forms new structures in the presence of multiple reconnection sites, one of which is dominant and others are secondary. The rise of the reconnection rate to a peak value and the time to reach the peak value due to tearing instability are similar to those observed in particle-in-cell simulations for similar thicknesses of the <span class="hlt">electron</span> current <span class="hlt">sheet</span>. The peak reconnection rate scales as 0.05 / ? 1.15 , where ? is half thickness of the current <span class="hlt">sheet</span>. Interactions of <span class="hlt">electron</span> outflows from the dominant and secondary sites form a double vortex <span class="hlt">sheet</span> inside the magnetic island between the two sites. <span class="hlt">Electron</span> Kelvin-Helmholtz instability in the double vortex <span class="hlt">sheet</span> produces secondary vortices and consequently turbulence inside the magnetic island. Interaction of outflow from the dominant site and inflows to the adjacent secondary sites launches whistler waves which propagate from the secondary sites into the upstream region at Storey angle with the background magnetic field. Due to the wave propagation, the out-of-plane magnetic field has a nested structure of quadrupoles of opposite polarities. A numerical linear eigen value analysis of the EMHD tearing mode, valid for current <span class="hlt">sheet</span> half-thicknesses ranging from ? < d e = c / ? p e (strong <span class="hlt">electron</span> inertia) to ? > d e (weak <span class="hlt">electron</span> inertia), is presented.</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 id="translatedtitle">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> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012AnGeo..30..661J','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012AnGeo..30..661J"><span id="translatedtitle"><span class="hlt">Electron</span> scale structures of thin current <span class="hlt">sheets</span> in magnetic reconnection</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Jain, N.; Sharma, A. S.; Zelenyi, L. M.; Malova, H. V.</p> <p>2012-04-01</p> <p>An <span class="hlt">electron</span>-magnetohydrodynamic model is used to simulate the structure of an <span class="hlt">electron</span> scale current <span class="hlt">sheet</span> during early phase of collisionless magnetic reconnection. The current <span class="hlt">sheet</span> develops structures, viz. bifurcated, filamented and triple-peak structures at different locations in the current <span class="hlt">sheet</span>. The reversal of the net out-of-plane electric field seen by <span class="hlt">electrons</span> bifurcates the current <span class="hlt">sheet</span> in the outflow regions, the individual peaks having scale sizes of a few <span class="hlt">electron</span> skin depths. Secondary instabilities of the bifurcated CS lead to its filamentation in the outflow and separatrix regions while triple-peak structures form at reconnection sites. These structures have implications for the forthcoming NASA/MMS mission designed to resolve <span class="hlt">electron</span> space and time scales in the magnetosphere.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19880059313&hterms=lower+hybrid+waves&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3Dlower%2Bhybrid%2Bwaves','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19880059313&hterms=lower+hybrid+waves&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3Dlower%2Bhybrid%2Bwaves"><span id="translatedtitle">Substorm-associated lower hybrid waves in the <span class="hlt">plasma</span> <span class="hlt">sheet</span> observed by ISEE 1</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.</p> <p>1987-01-01</p> <p>Observations of the electric field at frequencies from 2-128 Hz, using the burst mode of the spherical double probe on ISEE 1, have been examined for a time period previously identified as containing the traversal of a near-earth neutral line past the satellite. Intense waves (3 to over 30 mV/m) at approximately half the lower hybrid frequency were observed throughout the <span class="hlt">plasma</span> <span class="hlt">sheet</span> from the neutral <span class="hlt">sheet</span> to the boundary, but only during the period of the large dc electric field and E x B velocity associated with the substorm neutral line. The wave number deduced from linear fits of the data was comparable to the inverse <span class="hlt">electron</span> gyroradius. These results are consistent with the lower-hybrid drift instability. Although peaks between the ion and <span class="hlt">electron</span> <span class="hlt">plasma</span> frequency were sometimes observed simultaneously, the integrated power below 100 Hz was usually at least one to two orders of magnitude greater than that above 100 Hz. Although theoretical work has suggested that the instability would be suppressed at the neutral <span class="hlt">sheet</span>, the largest waves observed occurred right at the neutral <span class="hlt">sheet</span> when the southward component of the magnetic field was 6 gamma. The observed waves could provide an anomalous resistivity of about (3-1000) x 10 to the -7th S (compared to the classical value of 1 x 10 to the -18th S).</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/12856612','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/12856612"><span id="translatedtitle">[Oxygen <span class="hlt">plasma</span>-vulcanized deformable polydimethylsiloxane <span class="hlt">sheet</span> culture substrates].</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Zhang, Yiyi; Tao, Zulai</p> <p>2003-06-01</p> <p>A method of preparing deformable polydimethylsiloxane <span class="hlt">sheet</span> culture substrates by oxygen <span class="hlt">plasma</span> vulcanization was developed. As compared with the traditional heating vulcanization method, the substrates prepared in this way have hydrophilic surfaces, the adhesion and spreading of cells both occur quickly, and the wrinkling deformation of substrates develops quickly, too. In addition, the changes of wrinkles during treatment of cytochalasin D were observed, and the result shows that this technique has high temporal resolution. PMID:12856612</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014AGUFMSM51F4331H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014AGUFMSM51F4331H"><span id="translatedtitle">Mini-Magnetospheres at the Moon in the Solar Wind and 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>Harada, Y.; Futaana, Y.; Barabash, S. V.; Wieser, M.; Wurz, P.; Bhardwaj, A.; Asamura, K.; Saito, Y.; Yokota, S.; Tsunakawa, H.; Machida, S.</p> <p>2014-12-01</p> <p>Lunar mini-magnetospheres are formed as a consequence of solar-wind interaction with remanent crustal magnetization on the Moon. A variety of <span class="hlt">plasma</span> and field perturbations have been observed in a vicinity of the lunar magnetic anomalies, including <span class="hlt">electron</span> energization, ion reflection/deflection, magnetic field enhancements, electrostatic and electromagnetic wave activities, and low-altitude ion deceleration and <span class="hlt">electron</span> acceleration. Recent Chandrayaan-1 observations of the backscattered energetic neutral atoms (ENAs) from the Moon in the solar wind revealed upward ENA flux depletion (and thus depletion of the proton flux impinging on the lunar surface) in association with strongly magnetized regions. These ENA observations demonstrate that the lunar surface is shielded from the solar wind protons by the crustal magnetic fields. On the other hand, when the Moon was located in the Earth's <span class="hlt">plasma</span> <span class="hlt">sheet</span>, no significant depletion of the backscattered ENA flux was observed above the large and strong magnetic anomaly. It suggests less effective magnetic shielding of the surface from the <span class="hlt">plasma</span> <span class="hlt">sheet</span> protons than from the solar wind protons. We conduct test-particle simulations showing that protons with a broad velocity distribution are more likely to reach a strongly magnetized surface than those with a beam-like velocity distribution. The ENA observations together with the simulation results suggest that the lunar crustal magnetic fields are no longer capable of standing off the ambient <span class="hlt">plasma</span> when the Moon is immersed in the hot magnetospheric <span class="hlt">plasma</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19890000538&hterms=galvanometer&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3Dgalvanometer','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19890000538&hterms=galvanometer&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3Dgalvanometer"><span id="translatedtitle"><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://adsabs.harvard.edu/abs/2004JGRA..10912213S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2004JGRA..10912213S"><span id="translatedtitle">Two types of energy-dispersed ion structures at the <span class="hlt">plasma</span> <span class="hlt">sheet</span> boundary</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Sauvaud, J.-A.; Kovrazhkin, R. A.</p> <p>2004-12-01</p> <p>We study two main types of ion energy dispersions observed in the energy range ˜1 to 14 keV on board the Interball-Auroral (IA) satellite at altitudes 2-3 RE at the poleward boundary of the <span class="hlt">plasma</span> <span class="hlt">sheet</span>. The first type of structure is named velocity dispersed ion structures (VDIS). It is known that VDIS represent a global proton structure with a latitudinal width of ˜0.7-2.5°, where the ion overall energy increases with latitude. IA data allow to show that VDIS are made of substructures lasting for ˜1-3 min. Inside each substructure, high-energy protons arrive first, regardless of the direction of the <span class="hlt">plasma</span> <span class="hlt">sheet</span> boundary crossing. A near-continuous rise of the maximal and minimal energies of consecutive substructures with invariant latitude characterizes VDIS. The second type of dispersed structure is named time-of-flight dispersed ion structures (TDIS). TDIS are recurrent sporadic structures in H+ (and also O+) with a quasi-period of ˜3 min and a duration of ˜1-3 min. The maximal energy of TDIS is rather constant and reaches ?14 keV. During both poleward and equatorward crossings of the <span class="hlt">plasma</span> <span class="hlt">sheet</span> boundary, inside each TDIS, high-energy ions arrive first. These structures are accompanied by large fluxes of upflowing H+ and O+ ions with maximal energies up to 5-10 keV. In association with TDIS, bouncing H+ clusters are observed in quasi-dipolar magnetic field tubes, i.e., equatorward from TDIS. The <span class="hlt">electron</span> populations generally have different properties during observations of VDIS and TDIS. The <span class="hlt">electron</span> flux accompanying VDIS first increases smoothly and then decreases after Interball-Auroral has passed through the proton structure. The average <span class="hlt">electron</span> energy in the range ˜0.5-2 keV is typical for <span class="hlt">electrons</span> from the <span class="hlt">plasma</span> <span class="hlt">sheet</span> boundary layer (PSBL). The <span class="hlt">electron</span> fluxes associated with TDIS increases suddenly at the polar boundary of the auroral zone. Their average energy, reaching ˜5-8 keV, is typical for CPS. A statistical analysis shows that VDIS are observed mainly during magnetically quiet times and during the recovery phase of substorms, while sporadic and recurrent TDIS are observed during the onset and main phases of substorms and magnetic storms and, although less frequently, during substorm recovery phases. From the slope of the (velocity)-1 versus time dispersions of TDIS, we conclude that they have a sporadic source located at the outer boundary of the central <span class="hlt">plasma</span> <span class="hlt">sheet</span>, at distances from 8 to 40 RE in the equatorial plane. The disappearance of the PSBL associated with TDIS can be tentatively linked to a reconfiguration of the magnetotail, which disconnects from the Earth the field lines forming the "quiet" PSBL. We show that VDIS consist of ion beams ejected from an extended current <span class="hlt">sheet</span> at different distances. These ion beams could be formed in the neutral <span class="hlt">sheet</span> at distance ranging from ˜30 RE to ˜100 RE from the Earth. Inside each substructure the time-of-flight dispersion of ions generally dominate over any latitudinal dispersion induced by a dawn-dusk electric field. These two main types of energy-dispersed ion structures reflect probably two main states of the magnetotail, quiet and active. Finally, it must be stressed that only ˜49% (246 over 501) of the Interball-Auroral auroral zone-polar cap boundary crossings can be described as VDIS or TDIS. On the other 51% of the crossings of the <span class="hlt">plasma</span> <span class="hlt">sheet</span> boundary, no well-defined ion dispersed structures were observed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4459207','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4459207"><span id="translatedtitle">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('http://ntrs.nasa.gov/search.jsp?R=19900063372&hterms=solution+plasma+process&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3Dsolution%2Bplasma%2Bprocess','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19900063372&hterms=solution+plasma+process&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3Dsolution%2Bplasma%2Bprocess"><span id="translatedtitle">Resonant Alfven wave heating of 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>Harrold, B. G.; Goertz, C. K.; Smith, R. A.; Hansen, P. J.</p> <p>1990-01-01</p> <p>The exchange of energy between the <span class="hlt">plasma</span> mantle and the <span class="hlt">plasma</span> <span class="hlt">sheet</span> boundary layer (PSBL) is examined with a one-dimensional magnetotail model. The energy exchange occurs via Poynting flux generated by the localized mode conversion of a surface wave to an Alfven wave. This Poynting flux propagates through the lobe and into the PSBL where it is absorbed by two processes. The first arises from a gradient in the <span class="hlt">plasma</span> beta causing a smooth absorption of Poynting flux. The second process results from the localized mode conversion of the decaying surface wave to an Alfven wave, causing a localized absorption of energy. A numerical solution of the linearized ideal MHD equations is obtained by assuming an adiabatic equation of state.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015PhRvS..18h1304W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015PhRvS..18h1304W"><span id="translatedtitle">Optical <span class="hlt">plasma</span> torch <span class="hlt">electron</span> bunch generation in <span class="hlt">plasma</span> wakefield accelerators</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Wittig, G.; Karger, O.; Knetsch, A.; Xi, Y.; Deng, A.; Rosenzweig, J. B.; Bruhwiler, D. L.; Smith, J.; Manahan, G. G.; Sheng, Z.-M.; Jaroszynski, D. A.; Hidding, B.</p> <p>2015-08-01</p> <p>A novel, flexible method of witness <span class="hlt">electron</span> bunch generation in <span class="hlt">plasma</span> wakefield accelerators is described. A quasistationary <span class="hlt">plasma</span> region is ignited by a focused laser pulse prior to the arrival of the <span class="hlt">plasma</span> wave. This localized, shapeable optical <span class="hlt">plasma</span> torch causes a strong distortion of the <span class="hlt">plasma</span> blowout during passage of the <span class="hlt">electron</span> driver bunch, leading to collective alteration of <span class="hlt">plasma</span> <span class="hlt">electron</span> trajectories and to controlled injection. This optically steered injection is more flexible and faster when compared to hydrodynamically controlled gas density transition injection methods.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19990080077&hterms=McCarthy&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3DMcCarthy%252C%2BR','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19990080077&hterms=McCarthy&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3DMcCarthy%252C%2BR"><span id="translatedtitle">Understanding Substorms from the Auroral Ionosphere to the Distant <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>Parks, G. K.; Brittnacher, M.; Chen, L.; Chua, D.; Elsen, R.; Fillingim, M.; McCarthy, M.; Wilber, M.; Germany, G.; Spann, J.; Lin, R. P.</p> <p>1998-01-01</p> <p>The global polar UVI images have been correlated with observations from the ground, ionosphere, geomagnetic tail between 10-20 earth radii and the interplanetary space. One of the objectives of our study is to better understand the connection among many complex phenomena occurring close to Earth and those in the near--earth <span class="hlt">plasma</span> <span class="hlt">sheet</span>. We have examined the details of how the auroral and polar cap boundaries at different local times behave in relation to variations occurring in the solar wind, ionosphere and <span class="hlt">plasma</span> <span class="hlt">sheet</span> during substorms. We have also compared locations of boundaries deduced from images to <span class="hlt">electron</span> flux "boundaries" observed by polar orbiting spacecraft. Our results indicate that the ionospheric dynamics is important and polar cap and auroral oval boundaries expand and contract in a complicated but systematic way. These variations are correlated to solar wind parameters and growth and recovery phenomena in the <span class="hlt">plasma</span> <span class="hlt">sheet</span>. These results can be interpreted in terms of directly driven and/or unloading substorm processes.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/5523037','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/5523037"><span id="translatedtitle"><span class="hlt">Electron</span> collision frequency in <span class="hlt">plasmas</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Boercker, D.B.; Rogers, F.J.; DeWitt, H.E.</p> <p>1982-03-01</p> <p>In strongly coupled, degenerate <span class="hlt">plasmas</span>, the <span class="hlt">electron</span> collision frequency has been described by the Ziman formula with the ion-ion correlations modeled by the classical one-component <span class="hlt">plasma</span> (OCP). However, this model fails to reproduce the correct quantum Lenard-Balescu result in the weak-coupling limit. It is demonstrated here that a recently obtained, correlation-function expression for the collision frequency reduces to the Ziman and Lenard-Balescu results in the appropriate limits. In addition, it is shown that an extension of the Lenard-Balescu result to include strong coupling can be interpreted as the Ziman collision frequency with the OCP structure factor replaced by the ion-ion structure factor for a two-component system. Numerical estimates of this structure factor are used to calculate the electrical conductivity in moderately coupled (GAMMA< or =2) hydrogen <span class="hlt">plasmas</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20150007922','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20150007922"><span id="translatedtitle">Ion Kinetic Properties in Mercury's Pre-Midnight <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>Gershman, Daniel J.; Slavin, James A.; Raines, Jim M.; Zurbuchen, Thomas H.; Anderson, Brian J.; Korth, Haje; Baker, Daniel N.; Solomon, Sean C.</p> <p>2014-01-01</p> <p>With data from the Fast Imaging <span class="hlt">Plasma</span> Spectrometer sensor on the MErcury Surface, Space ENvironment, GEochemistry, and Ranging spacecraft, we demonstrate that the average distributions for both solar wind and planetary ions in Mercury's pre-midnight <span class="hlt">plasma</span> <span class="hlt">sheet</span> are well-described by hot Maxwell-Boltzmann distributions. Temperatures and densities of the H(+)-dominated <span class="hlt">plasma</span> <span class="hlt">sheet</span>, in the ranges is approx. 1-10 cm(exp -3) and is approx. 5-30MK, respectively, maintain thermal pressures of is approx.1 nPa. The dominant planetary ion, Na(+), has number densities about 10% that of H(+). Solar wind ions retain near-solar-wind abundances with respect to H(+) and exhibit mass-proportional ion temperatures, indicative of a reconnection-dominated heating in the magnetosphere. Conversely, planetary ion species are accelerated to similar average energies greater by a factor of is approx. 1.5 than that of H(+). This energization is suggestive of acceleration in an electric potential, consistent with the presence of a strong centrifugal acceleration process in Mercury's magnetosphere.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/22299965','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/22299965"><span id="translatedtitle">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> </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('http://adsabs.harvard.edu/abs/2015JGRA..120.8210K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015JGRA..120.8210K"><span id="translatedtitle">A new stationary analytical model of the heliospheric current <span class="hlt">sheet</span> and 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>Kislov, Roman A.; Khabarova, Olga V.; Malova, Helmi V.</p> <p>2015-10-01</p> <p>We develop a single-fluid 2-D analytical model of the axially symmetric thin heliospheric current <span class="hlt">sheet</span> (HCS) embedded into the heliospheric <span class="hlt">plasma</span> <span class="hlt">sheet</span> (HPS). A HCS-HPS system has a shape of a relatively thin <span class="hlt">plasma</span> disk limited by separatrices that also represent current <span class="hlt">sheets</span>, which is in agreement with Ulysses observations in the aphelion, when it crossed the HCS perpendicular to its plane. Our model employs a differential rotation of the solar photosphere that leads to unipolar induction in the corona. Three components of the interplanetary magnetic field (IMF), the solar wind speed, and the thermal pressure are taken into account. Solar corona conditions and a HCS-HPS system state are tied by boundary conditions and the "frozen-in" equation. The model allows finding spatial distributions of the magnetic field, the speed within the HPS, and electric currents within the HCS. An angular <span class="hlt">plasma</span> speed is low within the HPS due to the angular momentum conservation (there is no significant corotation with the Sun), which is consistent with observations. We found that the HPS thickness L decreases with distance r, becoming a constant far from the Sun (L ~2.5 solar radii (R0) at 1 AU). Above the separatrices and at large heliocentric distances, the solar wind behavior obeys Parker's model, but the magnetic field spiral form may be different from Parker's one inside the HPS. At r ? 245 R0, the IMF spiral may undergo a turn simultaneously with a change of the poloidal current direction (from sunward to antisunward).</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 id="translatedtitle">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> <li> <p><a target="_blank" onclick="trackOutboundLink('http://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="http://ntrs.nasa.gov/search.jsp?R=19920045465&hterms=irm&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3Dirm"><span id="translatedtitle">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/biblio/6200419','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/6200419"><span id="translatedtitle">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/2009A%26A...502..341W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009A%26A...502..341W"><span id="translatedtitle"><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('http://sprg.ssl.berkeley.edu/adminstuff/webpubs/2009_prl_155002.pdf','EPRINT'); return false;" href="http://sprg.ssl.berkeley.edu/adminstuff/webpubs/2009_prl_155002.pdf"><span id="translatedtitle">Observations of Double Layers in Earth's <span class="hlt">Plasma</span> <span class="hlt">Sheet</span> R. E. Ergun,1,2</span></a></p> <p><a target="_blank" href="http://www.osti.gov/eprints/">E-print Network</a></p> <p>Bonnell, John W.</p> <p></p> <p>Observations of Double Layers in Earth's <span class="hlt">Plasma</span> <span class="hlt">Sheet</span> R. E. Ergun,1,2 L. Andersson,2 J. Tao,1,2 V electric fields (Ek) carried by double layers (DLs) in the <span class="hlt">plasma</span> <span class="hlt">sheet</span> of Earth's magnetosphere. The DL boundary layer, all during periods of strong magnetic fluctuations. These observations imply that DLs</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://sprg.ssl.berkeley.edu/adminstuff/webpubs/2008_jgr_A07S35.pdf','EPRINT'); return false;" href="http://sprg.ssl.berkeley.edu/adminstuff/webpubs/2008_jgr_A07S35.pdf"><span id="translatedtitle">Response of the inner magnetosphere and the <span class="hlt">plasma</span> <span class="hlt">sheet</span> to a sudden R. Nakamura,1</span></a></p> <p><a target="_blank" href="http://www.osti.gov/eprints/">E-print Network</a></p> <p>California at Berkeley, University of</p> <p></p> <p>Response of the inner magnetosphere and the <span class="hlt">plasma</span> <span class="hlt">sheet</span> to a sudden impulse K. Keika,1 R. Nakamura caused a sudden compression of the magnetosphere between 0900 UT and 0915 UT on 24 August 2005) 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></p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.bu.edu/buspace/papers/Waldrop_1999_Jupiter_Plasma_Sheet_Crossings.pdf','EPRINT'); return false;" href="http://www.bu.edu/buspace/papers/Waldrop_1999_Jupiter_Plasma_Sheet_Crossings.pdf"><span id="translatedtitle"><span class="hlt">Plasma</span> <span class="hlt">sheet</span> crossings at Jupiter: Energetic particle observations with the Galileo spacecraft</span></a></p> <p><a target="_blank" href="http://www.osti.gov/eprints/">E-print Network</a></p> <p></p> <p></p> <p>1 <span class="hlt">Plasma</span> <span class="hlt">sheet</span> crossings at Jupiter: Energetic particle observations with the Galileo spacecraft L in the outer Jovian magnetosphere by the Energetic Particles Detector (EPD) onboard the Galileo space- craft conditions are a more likely explanation of their origin. Keywords: <span class="hlt">Plasma</span> <span class="hlt">sheet</span>; Galileo; Jupiter</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://space.unh.edu/~rlk/research/reprints/jgr_107_1103_2002.pdf','EPRINT'); return false;" href="http://space.unh.edu/~rlk/research/reprints/jgr_107_1103_2002.pdf"><span id="translatedtitle">Three-dimensional analyses of electric currents and pressure anisotropies in the <span class="hlt">plasma</span> <span class="hlt">sheet</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/eprints/">E-print Network</a></p> <p>Kaufmann, Richard L.</p> <p></p> <p>Three-dimensional analyses of electric currents and pressure anisotropies in the <span class="hlt">plasma</span> <span class="hlt">sheet</span> to calculate average electric currents flowing in the x and y directions. Full 3-D distributions of jx and jy); 2712 Magnetospheric Physics: Electric fields (2411); KEYWORDS: <span class="hlt">plasma</span> <span class="hlt">sheet</span>, magnetotail, current</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.glue.umd.edu/~sitnov/TCS/tcs_1_files/ABS/chengabs.pdf','EPRINT'); return false;" href="http://www.glue.umd.edu/~sitnov/TCS/tcs_1_files/ABS/chengabs.pdf"><span id="translatedtitle">3D Cross-Tail Current Structure in Near-Earth <span class="hlt">Plasma</span> <span class="hlt">Sheet</span> and Ballooning Instability as Substorm Onset Mechanism</span></a></p> <p><a target="_blank" href="http://www.osti.gov/eprints/">E-print Network</a></p> <p>Sitnov, Mikhail I.</p> <p></p> <p>3D Cross-Tail Current Structure in Near-Earth <span class="hlt">Plasma</span> <span class="hlt">Sheet</span> and Ballooning Instability as Substorm to have a good knowledge of the 3D structure of cross-tail current <span class="hlt">sheet</span> in the near-Earth <span class="hlt">plasma</span> <span class="hlt">sheet</span> magnetosphere [Zaharia and Cheng(2003)] and find that a current <span class="hlt">sheet</span> with an enhanced cross-tail current</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015PhPl...22i2905C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015PhPl...22i2905C"><span id="translatedtitle">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://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Catapano, F.; Artemyev, A. V.; Zimbardo, G.; Vasko, I. Y.</p> <p>2015-09-01</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('http://www.osti.gov/scitech/biblio/5255353','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/5255353"><span id="translatedtitle">Characteristic of high-speed ion flows 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>Baumjohann, W.; Paschmann, G. ); Luehr, H. )</p> <p>1990-04-01</p> <p>Using 8 months of tail data obtained with the AMPTE/IRM satellite, more than 270,000 ion moments and magnetic field measurements were analyzed with respect to the occurrence rates and typical characteristics of high-speed ion flows with velocities in excess of 400 km/s. The occurrence rates in the <span class="hlt">plasma</span> <span class="hlt">sheet</span> boundary layer, the outer central <span class="hlt">plasma</span> <span class="hlt">sheet</span> and the neutral <span class="hlt">sheet</span> neighborhood have a 4:1:2 ratio for flows of 400-600 km/s. For flows in excess of 800 km/s, there is only a minimal chance to detect them in the outer central <span class="hlt">plasma</span> <span class="hlt">sheet</span> but equal chances in the two other regions. For high AE the chances to detect high-speed flows in the inner central <span class="hlt">plasma</span> <span class="hlt">sheet</span> are greater than to find them in the <span class="hlt">plasma</span> <span class="hlt">sheet</span> boundary layer. In the outer central <span class="hlt">plasma</span> <span class="hlt">sheet</span> the high-speed flow occurrence rate is small and independent of AE. In all three regions the largest occurrence rates are found near the midnight meridian at the largest radial distances accessible to IRM. High-speed flow occurrence rates and ion densities are anticorrelated. The high-speed slows are bursty with the majority of the flows lasting less than 10 s. The occurrence of the high-speed flows is strongly peaked in the sunward direction. Virtually no tailward high-speed ion flow could be detected. About 60-70% of all high-speed flows near the neutral <span class="hlt">sheet</span> have a dominant component perpendicular to the magnetic field and are associated with comparatively large northward and duskward magnetic field directions. At times, also appreciable duskward flow components appear. Overall, the results indicate that both the <span class="hlt">plasma</span> <span class="hlt">sheet</span> boundary layer and the inner central <span class="hlt">plasma</span> <span class="hlt">sheet</span> are important regions for the dynamics of the Earth's <span class="hlt">plasma</span> <span class="hlt">sheet</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://silis.phys.strath.ac.uk/publications/Articles/Reitsma-plasma_kinetic_theory-ptrsa06.pdf','EPRINT'); return false;" href="http://silis.phys.strath.ac.uk/publications/Articles/Reitsma-plasma_kinetic_theory-ptrsa06.pdf"><span id="translatedtitle"><span class="hlt">Electron</span> and photon beams interacting with <span class="hlt">plasma</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/eprints/">E-print Network</a></p> <p>Strathclyde, University of</p> <p></p> <p><span class="hlt">Electron</span> and photon beams interacting with <span class="hlt">plasma</span> BY ALBERT REITSMA AND DINO JAROSZYNSKI A comparison is made between the interaction of <span class="hlt">electron</span> bunches and intense laser pulses with <span class="hlt">plasma</span> comparison with the phase space evolution of the <span class="hlt">electron</span> bunch. Analytical results are presented</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://socrates.berkeley.edu/~fajans/Gradient/GradientPoster.PDF','EPRINT'); return false;" href="http://socrates.berkeley.edu/~fajans/Gradient/GradientPoster.PDF"><span id="translatedtitle"><span class="hlt">Electron</span> <span class="hlt">Plasmas</span> in a Magnetic Mirror</span></a></p> <p><a target="_blank" href="http://www.osti.gov/eprints/">E-print Network</a></p> <p>Wurtele, Jonathan</p> <p></p> <p>1 <span class="hlt">Electron</span> <span class="hlt">Plasmas</span> in a Magnetic Mirror Ramesh Gopalan Joel Fajans U.C. Berkeley We have studied the equilibria of pure <span class="hlt">electron</span> <span class="hlt">plasmas</span> in a Penning-Malmberg trap with an axially-varying magnetic field, <span class="hlt">electrons</span> are trapped both in the high-field region and low-field region. Our experimental observations</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 id="translatedtitle">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('http://www.osti.gov/scitech/servlets/purl/927792','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/927792"><span id="translatedtitle">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/2014AGUFMSH43A4182K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014AGUFMSH43A4182K"><span id="translatedtitle">Magnetic reconnection at the solar wind current <span class="hlt">sheets</span> as a possible cause of strahl <span class="hlt">electrons</span> acceleration and SEP dropouts</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Khabarova, O.; Zharkova, V. V.</p> <p>2014-12-01</p> <p>According to the shape of the <span class="hlt">electron</span> velocity distribution function, there are two populations of suprathermal <span class="hlt">electrons</span>: halo and strahls (beams). The halo <span class="hlt">electrons</span> are omni-directional, and strahls are magnetic field aligned beams of <span class="hlt">electrons</span> that predominantly move in the anti-sunward direction. Properties of strahls represent a great interest, because this population is most energetic, but its origination is still unclear. Usually, it is supposed that strahls is a focused part of halo <span class="hlt">electrons</span>, non-scattered during their propagation from the Sun. We demonstrate a possibility to better understand nature of strahls if to suggest their acceleration directly in the solar wind due to a magnetic reconnection, occurring at current <span class="hlt">sheets</span>. We use results of our PIC-simulation of particles behaviour at reconnecting current <span class="hlt">sheets</span> (Zharkova, Khabarova, ApJ, 2012) in order to explain such effects as:- mismatches between a position of suprathermal <span class="hlt">electrons</span> pitch-angle changes and real crossing of the heliospheric current <span class="hlt">sheet</span>,- correlation between heat flux/solar energetic particles dropouts and high <span class="hlt">plasma</span> beta,- occurrence of counterstreaming <span class="hlt">electrons</span> at the ICME front and at corotating shocks at r > 2 AU,- radial evolution of strahls/halo density.Multi-spacecraft observations (STEREO, ACE, Ulysses) of properties of suprathermal <span class="hlt">electrons</span> attributed to crossings of the heliospheric current <span class="hlt">sheet</span> as well as smaller-scale current <span class="hlt">sheets</span> during SEP events and CME-CIR interactions will be discussed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2001APS..DPPGP1136S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2001APS..DPPGP1136S"><span id="translatedtitle">Rf <span class="hlt">sheet-plasma</span> production using permanent magnets</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Sakawa, Youichi; Yano, Kentaro; Shoji, Tatsuo</p> <p>2001-10-01</p> <p>High-density <span class="hlt">sheet-plasmas</span> with a rectangular cross-section of 140 mm × 20 mm are developed by inductive rf discharge using a rectangular discharge section and a pair of permanent magnets. The stainless-steel discharge section is 200 mm wide, 20 mm high, and 100 mm long. A pair of ferrite permanent magnets (length L_mag = 20 - 140 mm in S-N direction, width W_mag = 50 - 170 mm, and height = 24 mm) is placed on top and bottom of the discharge section and a static magnetic field of B0 ~= 600 - 800 G is generated under the center of the magnets. Rf current (frequency = 13.56 MHz and power P_rf <= 4.5 kW) is applied to an internal antenna covered with a quartz tube in the direction perpendicular to B_0. The antenna is located behind the magnets where B0 is nearly zero. <span class="hlt">Plasma</span> density np profile is controlled by varying W_mag and distance between the antenna and the magnets due to cusped magnetic field generated by magnets. 140 mm wide <span class="hlt">plasma</span> (np ~= 2.5 × 10^12 cm-3) of a uniformity variation within 90% is produced using 140 mm long antenna for L_mag = 20 mm, W_mag = 120 mm, Ar pressure = 20 mTorr, and P_rf = 3 kW.</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 id="translatedtitle">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('http://adsabs.harvard.edu/abs/2015AdSpR..56.1194C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015AdSpR..56.1194C"><span id="translatedtitle">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 ?T (the time difference between IBIPS crossing time and preceding Kp interval), which suggests that with the increase of ?T, 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 ?T > 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> </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('http://www.osti.gov/scitech/biblio/22407995','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/22407995"><span id="translatedtitle"><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://w3.pppl.gov/~ikaganov/Application%20of%20Nonlocal%20Electron%20Kinetics%202011.pdf','EPRINT'); return false;" href="http://w3.pppl.gov/~ikaganov/Application%20of%20Nonlocal%20Electron%20Kinetics%202011.pdf"><span id="translatedtitle">Application of Nonlocalpp <span class="hlt">Electron</span> Kinetics to <span class="hlt">Plasma</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/eprints/">E-print Network</a></p> <p>Kaganovich, Igor</p> <p></p> <p>, and C.E. Theodosiou, IEEE Trans ANODE CATHODE <span class="hlt">Plasma</span> Sci. 33, 510 (2005). 7 #12;Explosive generationApplication of Nonlocalpp <span class="hlt">Electron</span> Kinetics to <span class="hlt">Plasma</span> TechnologiesTechnologies Igor D. Kaganovich1 Schweigert4, and Alexander S. Mustafaev5 1Princeton <span class="hlt">Plasma</span> Physics Laboratory, NJ, USA 2 University</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1999JGR...104.2443K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1999JGR...104.2443K"><span id="translatedtitle">Finite Larmor radius convection instability in the 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>Kozlovsky, A.; Lyatsky, W.</p> <p>1999-02-01</p> <p>Violation of the frozen-in condition for the <span class="hlt">plasma</span> <span class="hlt">sheet</span> ions when the spatial scale of disturbance is of the order of the Larmor radius leads to the magnetospheric convection instability. This instability results in the separation of the convection <span class="hlt">plasma</span> flow into jets with the spatial scale of the order of 1 km (from a few hundreds meters up to a few kilometers) at the ionosphere level. The instability develops in these regions of the <span class="hlt">plasma</span> <span class="hlt">sheet</span> where the contents of the hot ions in the unit magnetic flux tube vary with the distance from the Earth. This takes place at the boundaries of the <span class="hlt">plasma</span> <span class="hlt">sheet</span>. The instability has a large growth rate (up to 0.01 s-1). In the nighside <span class="hlt">plasma</span> <span class="hlt">sheet</span> region the developing structures are stretched approximately along the auroral oval.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/6162780','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/6162780"><span id="translatedtitle">Isotropized magnetic-moment equation of state for the central <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>Kan, J.R. ); Baumjohann, W. )</p> <p>1990-03-01</p> <p>The AMPTE/IRM <span class="hlt">plasma</span> and magnetic field data show that the compression in the central <span class="hlt">plasma</span> <span class="hlt">sheet</span> (< 20 R{sub E} radial distance) near the equatorial plane is governed by the isotropized magnetic-moment equation of state, P/(NB{sub z}) = constant, derived from the invariance of the magnetic moment under the assumption of isotropic ion pressure P where N is the number density and B{sub z} is the normal field component in the <span class="hlt">plasma</span> <span class="hlt">sheet</span>. The adiabatic equation of state, P/N{sup 5/3} = constant, can be expected to govern the compression in the distant <span class="hlt">plasma</span> <span class="hlt">sheet</span> (> 20 R{sub E}) or the <span class="hlt">plasma</span> <span class="hlt">sheet</span> boundary layer where fewer particles are likely to escape from a flux tube through the loss cone to meet the particle conservation requirement of the adiabatic condition.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/22218331','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/22218331"><span id="translatedtitle">Nonlinear <span class="hlt">electron</span> oscillations in a warm <span class="hlt">plasma</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Sarkar, Anwesa; Maity, Chandan; Chakrabarti, Nikhil</p> <p>2013-12-15</p> <p>A class of nonstationary solutions for the nonlinear <span class="hlt">electron</span> oscillations of a warm <span class="hlt">plasma</span> are presented using a Lagrangian fluid description. The solution illustrates the nonlinear steepening of an initial Gaussian <span class="hlt">electron</span> density disturbance and also shows collapse behavior in time. The obtained solution may indicate a class of nonlinear transient structures in an unmagnetized warm <span class="hlt">plasma</span>.</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 id="translatedtitle">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://www.osti.gov/scitech/servlets/purl/10146831','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/10146831"><span id="translatedtitle">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://adsabs.harvard.edu/abs/2006ApPhL..89x1919C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2006ApPhL..89x1919C"><span id="translatedtitle">Resistance and <span class="hlt">sheet</span> resistance measurements using <span class="hlt">electron</span> beam induced current</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Czerwinski, A.; P?uska, M.; Ratajczak, J.; Szerling, A.; K?tcki, J.</p> <p>2006-12-01</p> <p>A method for measurement of spatially uniform or nonuniform resistance in layers and strips, based on <span class="hlt">electron</span> beam induced current (EBIC) technique, is described. High <span class="hlt">electron</span> beam currents are used so that the overall resistance of the measurement circuit affects the EBIC signal. During the evaluation, the <span class="hlt">electron</span> beam is scanned along the measured object, whose load resistance varies with the distance. The variation is compensated by an adjustable resistance within an external circuit. The method has been experimentally deployed for <span class="hlt">sheet</span> resistance determination of buried regions of lateral confinements in semiconductor laser heterostructures manufactured by molecular beam epitaxy.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://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="http://ntrs.nasa.gov/search.jsp?R=19920050936&hterms=irm&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3Dirm"><span id="translatedtitle">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://www.osti.gov/scitech/biblio/5556440','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/5556440"><span id="translatedtitle">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://www.osti.gov/scitech">SciTech Connect</a></p> <p>Angelopoulos, V.; Kennel, C.F.; Coroniti, F.V.; Kivelson, M.G.; Pellat, R.; Walker, R.J. ); Baumjohann, W.; Paschmann, G. ); Luehr, H. )</p> <p>1992-04-01</p> <p>High speed flow in the inner central <span class="hlt">plasma</span> <span class="hlt">sheet</span> are studied, together with the concurrent behavior of the <span class="hlt">plasma</span> and magnetic field, by using AMPTE/IRM data from {approx} 9 to 19 R{sub E} in the Earth's magnetotail. The conclusions drawn from the detailed analysis of a representative event are reinforced by a superposed epoch analysis on 2 years of data. The high-speed flows organize themselves in 10-min time scale flow enhancements which they call 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 temperatures 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 {times} 10{sup 19} ergs/R{sub E}{sup 2}.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19960021319&hterms=dryer&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D70%26Ntt%3Ddryer','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19960021319&hterms=dryer&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D70%26Ntt%3Ddryer"><span id="translatedtitle">Interaction of an interplanetary shock with 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>Odstrcil, D.; Dryer, M.; Smith, Z.</p> <p>1995-01-01</p> <p>Interplanetary shocks often propagate along the heliospheric <span class="hlt">plasma</span> <span class="hlt">sheet</span> (HPS) where the interplanetary magnetic field (IMF) changes its polarity. This problem is investigated by the time-dependent 2.5-D MHD numerical model in the meridional plane. An example of computation is shown in the figure using density (log) contours and IMF vectors. Values of <span class="hlt">plasma</span> parameters along the HPS fluctuate in time due to the Kelvin-Helmholtz instability. The HPS with its decreased intensity of the IMF as well as with its increased mass density causes a dimple in the shock structure (relatively weak for the forward shock, significant for the reverse shock, and very large for the contact discontinuity). Beyond the forward shock, the HPS is slightly compressed due to the post-shock increase of the azimuthal IMF component. Then follows expansion of the HPS surrounded by the highly-deformed contact discontinuity. A significant draping of IMF lines occurs around this structure that increases the meridional component of the IMF. This can cause a favorable condition for initiation of a geomagnetic storm.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/20217895','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/20217895"><span id="translatedtitle"><span class="hlt">Plasma</span> sources for <span class="hlt">electrons</span> and ion beams</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Leung, Ka-Ngo</p> <p>1999-11-01</p> <p><span class="hlt">Plasma</span> devices are commonly used for the production of ion beams. It has been demonstrated that the multicusp generator can produce very low energy ion beams for ion projection lithography applications. The multicusp source has also found important applications in focused ion beam systems. With its high and uniform <span class="hlt">plasma</span> density, attempts have been made to extract high brightness <span class="hlt">electron</span> beams from this type of <span class="hlt">plasma</span> source, making it also useful for <span class="hlt">electron</span> beam lithography applications. (c) 1999 American Vacuum Society.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19840028493&hterms=electron&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DTitle%26N%3D0%26No%3D70%26Ntt%3Delectron','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19840028493&hterms=electron&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DTitle%26N%3D0%26No%3D70%26Ntt%3Delectron"><span id="translatedtitle">Collisionless <span class="hlt">electron</span> shocks in <span class="hlt">electron-beam-plasma</span> systems</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Singh, N.; Schunk, R. W.</p> <p>1983-01-01</p> <p>One-dimensional Vlasov simulations show that when an <span class="hlt">electron</span> beam is suddenly injected into a <span class="hlt">plasma</span>, a fast-moving monotonic shock forms during the early stage of the transient <span class="hlt">plasma</span> response. In the shock, the ions are nearly immobile. The shock appears to be an electrostatic <span class="hlt">electron-beam-plasma</span> mode. The shock evolves from an initial positive potential perturbation, which is supported by an ion burst. The steepening of the perturbation into a shock is characterized by an <span class="hlt">electron-beam-plasma</span> mode.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19870056454&hterms=strobel&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAuthor-Name%26N%3D0%26No%3D60%26Ntt%3Dstrobel','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19870056454&hterms=strobel&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAuthor-Name%26N%3D0%26No%3D60%26Ntt%3Dstrobel"><span id="translatedtitle">Io <span class="hlt">plasma</span> torus <span class="hlt">electrons</span> - Voyager 1</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.; Strobel, Darrell F.</p> <p>1987-01-01</p> <p>A thermal Maxwellian component of the <span class="hlt">electron</span> distribution function, together with a suprathermal, non-Maxwellian one, are featured in the present analysis of in situ <span class="hlt">plasma</span> <span class="hlt">electron</span> observations made by the Voyager 1 <span class="hlt">plasma</span> science experiment in the Io <span class="hlt">plasma</span> torus. A large difference in the hot <span class="hlt">electron</span> pressure P(H) is noted between the inbound and the outbound data; this is interpreted as a latitudinal gradient, with P(H) being maximum at the magnetic equator. The presence of a neutral corona around Io is inferred from the observed decrease and symmetry with respect to Io of the cold <span class="hlt">electron</span> temperature.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015GeoRL..42.7264N','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015GeoRL..42.7264N"><span id="translatedtitle">Slow <span class="hlt">electron</span> holes in multicomponent <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>Norgren, C.; André, M.; Graham, D. B.; Khotyaintsev, Yu. V.; Vaivads, A.</p> <p>2015-09-01</p> <p>Electrostatic solitary waves (ESWs), often interpreted as <span class="hlt">electron</span> phase space holes, are commonly observed in <span class="hlt">plasmas</span> and are manifestations of strongly nonlinear processes. Often slow ESWs are observed, suggesting generation by the Buneman instability. The instability criteria, however, are generally not satisfied. We show how slow <span class="hlt">electron</span> holes can be generated by a modified Buneman instability in a <span class="hlt">plasma</span> that includes a slow <span class="hlt">electron</span> beam on top of a warm thermal <span class="hlt">electron</span> background. This lowers the required current for marginal instability and allows for generation of slow <span class="hlt">electron</span> holes for a wide range of beam parameters that covers expected <span class="hlt">plasma</span> distributions in space, for example, in magnetic reconnection regions. At higher beam speeds, the <span class="hlt">electron-electron</span> beam instability becomes dominant instead, producing faster <span class="hlt">electron</span> holes. The range of phase speeds for this model is consistent with a statistical set of observations at the magnetopause made by Cluster.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://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="http://ntrs.nasa.gov/search.jsp?R=19820051677&hterms=streaming&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D60%26Ntt%3Dstreaming"><span id="translatedtitle"><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('http://www.osti.gov/scitech/biblio/21274276','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/21274276"><span id="translatedtitle">Validity of closed periodic magnetic focusing for <span class="hlt">sheet</span> <span class="hlt">electron</span> beams</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Zhao Ding</p> <p>2009-11-15</p> <p>Theoretical analyses and numerical calculations have demonstrated that a closed periodic cusped magnetic (PCM) field can effectively confine a <span class="hlt">sheet</span> <span class="hlt">electron</span> beam in two transverse directions (i.e., in the wide and narrow dimensions, simultaneously) for stable long distance transport in which the sizes of the beam cross section are set by referring to the present state of the art. Moreover, the method for matching the transverse magnetic focusing force and the inner space charge force in the wide dimension of the <span class="hlt">sheet</span> <span class="hlt">electron</span> beam is given, and the longitudinal periodic length and the cross sectional shape of the closed PCM focusing structure can be determined. Calculations also demonstrate that the optimum focusing state can be attained by adjusting the wide dimension on the transverse section of the closed PCM structure independently. The work presented in this paper indicates that the closed PCM structure is very promising for the confinement of the <span class="hlt">sheet</span> <span class="hlt">electron</span> beam, and it can be helpful for guiding practical engineering design.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010AGUFMSM41C1884G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010AGUFMSM41C1884G"><span id="translatedtitle">Effect of self-consistent magnetic field on <span class="hlt">plasma</span> <span class="hlt">sheet</span> penetration to the inner magnetosphere under enhanced convection: RCM simulations combined with force-balance magnetic field solver</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Gkioulidou, M.; Wang, C.; Lyons, L. R.; Wolf, R. A.</p> <p>2010-12-01</p> <p>Transport of <span class="hlt">plasma</span> <span class="hlt">sheet</span> particles into the inner magnetosphere is strongly affected by the penetration of the convection electric field, which is the result of the large-scale magnetosphere-ionosphere electromagnetic coupling. This transport, on the other hand, results in <span class="hlt">plasma</span> heating and magnetic field stretching, which become very significant in the inner <span class="hlt">plasma</span> <span class="hlt">sheet</span> (inside 20 RE). We have previously run simulations with the Rice Convection Model (RCM) to investigate how the earthward penetration of convection electric field, and therefore <span class="hlt">plasma</span> <span class="hlt">sheet</span> population, depends on <span class="hlt">plasma</span> <span class="hlt">sheet</span> boundary conditions. Outer boundary conditions at r ~20 RE are a function of MLT and interplanetary conditions based on 11 years of Geotail data. In the previous simulations, Tsyganenko 96 magnetic field model (T96) was used so force balance between <span class="hlt">plasma</span> pressure and magnetic fields was not maintained. We have now integrated the RCM with a magnetic field solver (Liu et al., 2006) to obtain the required force balance in the equatorial plane. We have run the self-consistent simulations under enhanced convection with different boundary conditions in which we kept different parameters (flux tube particle content, <span class="hlt">plasma</span> pressure, <span class="hlt">plasma</span> beta, or magnetic fields) at the outer boundary to be MLT-dependent but time independent. Different boundary conditions result in qualitatively similar <span class="hlt">plasma</span> <span class="hlt">sheet</span> profiles. The results show that magnetic field has a dawn dusk asymmetry with field lines being more stretched in the pre-midnight sector, due to relatively higher <span class="hlt">plasma</span> pressure there. The asymmetry in the magnetic fields in turn affects the radial distance and MLT of <span class="hlt">plasma</span> <span class="hlt">sheet</span> penetration into the inner magnetosphere. In comparison with results using the T96, <span class="hlt">plasma</span> transport under self-consistent magnetic field results in proton and <span class="hlt">electron</span> <span class="hlt">plasma</span> <span class="hlt">sheet</span> inner edges that are located in higher latitudes, weaker pressure gradients, and more efficient shielding of the near-Earth convection electric field (since auroral conductance is also confined to higher latitudes). We are currently evaluating the simulated <span class="hlt">plasma</span> <span class="hlt">sheet</span> properties by comparing them with statistical results obtained from Geotail and THEMIS observations.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/22258614','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/22258614"><span id="translatedtitle">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??/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??/sq.), compared to films with higher <span class="hlt">sheet</span> resistance (400–600??/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??/sq. to 70??/sq. for a 20?nm TiN film (corresponding resistivity ?145 ??·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('http://ntrs.nasa.gov/search.jsp?R=19810050965&hterms=Planck+Max&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D70%26Ntt%3D%2528Planck%2BMax%2529','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19810050965&hterms=Planck+Max&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D70%26Ntt%3D%2528Planck%2BMax%2529"><span id="translatedtitle">Substorm-related <span class="hlt">plasma</span> <span class="hlt">sheet</span> motions as determined from differential timing of <span class="hlt">plasma</span> changes at the ISEE satellites</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Forbes, T. G.; Hones, E. W., Jr.; Bame, S. J.; Asbridge, J. R.; Paschmann, G.; Sckopke, N.; Russell, C. T.</p> <p>1981-01-01</p> <p>From an ISEE survey of substorm dropouts and recoveries during the period February 5 to May 25, 1978, 66 timing events observed by the Los Alamos Scientific Laboratory/Max-Planck-Institut Fast <span class="hlt">Plasma</span> Experiments were studied in detail. Near substorm onset, both the average timing velocity and the bulk flow velocity at the edge of the <span class="hlt">plasma</span> <span class="hlt">sheet</span> are inward, toward the center. Measured normal to the surface of the <span class="hlt">plasma</span> <span class="hlt">sheet</span>, the timing velocity is 23 + or - 18 km/s and the proton flow velocity is 20 + or - 8 km/s. During substorm recovery, the <span class="hlt">plasma</span> <span class="hlt">sheet</span> reappears moving outward with an average timing velocity of 133 + or - 31 km/s; however, the corresponding proton flow velocity is only 3 + or - 7 km/s in the same direction. It is suggested that the difference between the average timing velocity for the expansion of the <span class="hlt">plasma</span> <span class="hlt">sheet</span> and the <span class="hlt">plasma</span> bulk flow perpendicular to the surface of the <span class="hlt">sheet</span> during substorm recovery is most likely the result of surface waves moving past the position of the satellites.</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://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="http://ntrs.nasa.gov/search.jsp?R=19760008620&hterms=Auroras&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3DAuroras"><span id="translatedtitle">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/2015JGRA..120.7522B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015JGRA..120.7522B"><span id="translatedtitle">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.-Z.</p> <p>2015-09-01</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, which, 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" observations.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/958416','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/958416"><span id="translatedtitle">Identification of the <span class="hlt">Electron</span> Diffusion Region during Magnetic Reconnection 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>Ren, Yang; Yamada, Masaaki; Ji, Hantao; Gerhardt, Stefan; Kulsrud, Russell</p> <p>2008-06-26</p> <p>We report the first identification of the <span class="hlt">electron</span> diffusion region, where demagnetized <span class="hlt">electrons</span> are accelerated to super-Alfvenic speed, in a reconnecting laboratory <span class="hlt">plasma</span>. The <span class="hlt">electron</span> diffusion region is determined from measurements of the out-of-plane quadrupole magnetic field in the neutral <span class="hlt">sheet</span> in the Magnetic Reconnection Experiment. The width of the <span class="hlt">electron</span> diffusion region scales with the <span class="hlt">electron</span> skin depth (~ 5.5-7.5c=?pi) and the peak <span class="hlt">electron</span> outflow velocity scales with the <span class="hlt">electron</span> Alfven velocity (~ 0.12 - 0.16VeA), independent of ion mass.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/21357551','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/21357551"><span id="translatedtitle">Short pulse, high power microwave radiation source with a laser-induced <span class="hlt">sheet</span> <span class="hlt">plasma</span> mirror</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Higashiguchi, Takeshi; Yugami, Noboru</p> <p>2009-05-01</p> <p>We have demonstrated the short pulse, high power microwave radiation source using an ultraviolet laser-induced <span class="hlt">sheet</span> <span class="hlt">plasma</span> mirror in a gas-filled x-band rectangular waveguide from the conventional microwave sources and components. A laser-induced <span class="hlt">sheet</span> <span class="hlt">plasma</span> with an overdense <span class="hlt">plasma</span> acts as a <span class="hlt">plasma</span> mirror. The long pulse propagating in the gas-filled waveguide was sliced by the <span class="hlt">sheet</span> <span class="hlt">plasma</span> mirror at two different points along the waveguide. We observed about twice the power of the pulse by adding the two sliced microwave pulses produced by this scheme. A maximum peak power of 200 kW with a pulse duration of 10 ns (full width at half maximum) from the long microwave pulse source with a pulse duration of 0.8 mus was observed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/25186188','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/25186188"><span id="translatedtitle">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="http://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>2014-09-01</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. PMID:25186188</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/21502826','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/21502826"><span id="translatedtitle"><span class="hlt">Electron</span> capture rates in a <span class="hlt">plasma</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Sawyer, R. F.</p> <p>2011-06-15</p> <p>A new general expression is derived for nuclear <span class="hlt">electron</span> capture rates within dense <span class="hlt">plasmas</span>. Its qualitative nature leads us to question some widely accepted assumptions about how to calculate the effects of the <span class="hlt">plasma</span> on the rates. A perturbative evaluation, though not directly applicable to the strongly interacting case, appears to bear out these suspicions.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/6904217','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/6904217"><span id="translatedtitle">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('http://ntrs.nasa.gov/search.jsp?R=19780054813&hterms=electron&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DTitle%26N%3D0%26No%3D90%26Ntt%3Delectron','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19780054813&hterms=electron&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DTitle%26N%3D0%26No%3D90%26Ntt%3Delectron"><span id="translatedtitle">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('http://ntrs.nasa.gov/search.jsp?R=19950045562&hterms=lower+hybrid+waves&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D80%26Ntt%3Dlower%2Bhybrid%2Bwaves','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19950045562&hterms=lower+hybrid+waves&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D80%26Ntt%3Dlower%2Bhybrid%2Bwaves"><span id="translatedtitle">Geotail observations of spiky electric fields and low-frequency waves in the <span class="hlt">plasma</span> <span class="hlt">sheet</span> and <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>Cattell, C.; Mozer, F.; Tsuruda, K.; Hayakawa, H.; Nakamura, M.; Okada, T.; Kokubun, S.; Yamamoto, T.</p> <p>1994-01-01</p> <p>Electric field data from the Geotail spacecraft provide an opportunity to extend the observations of spiky fields made by International Sun Earth Explorer-1 (ISEE-1) to a region of the magnetosphere where quasistatic electric field measurements have not previously been msde, to examine their possible importance in the dynamics of the middle and distant tail, and to test some hypotheses about their formation. In this paper, examples of large fields in the <span class="hlt">plasma</span> <span class="hlt">sheet</span> and its boundary at radial distances up to approximately 90 R(sub E) are presented. It is shown that three different types of large electric fields can occur: (1) spiky fields; (2) 'DC' fields; and (3) waves at frequencies comparable to the lower hybrid frequency. There is usually a gradation between (1) and (3), and often large electric field spikes are embedded in regions of lower amplitude waves. The waves tend to occur in short (few to 10's of seconds) packets whose start and stop times are not always correlated with changes in the magnetic field and/or density (as indicated by the spacecraft potential). The peak frequency is often less than but comparable to the lower hybrid frequency in agreement with theories of lower hybrid drift waves in the magnetotail. The largest spikes are not always associated with the largest changes in the spacecraft potential and/or magnetic field. It is suggested that the spiky fields may represent the nonlinear development of the waves.</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 id="translatedtitle">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('http://www.osti.gov/scitech/servlets/purl/1212467','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/1212467"><span id="translatedtitle">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('http://www.osti.gov/pages/biblio/1212467-shape-terrestrial-plasma-sheet-near-earth-magnetospheric-tail-imaged-interstellar-boundary-explorer','SCIGOV-DOEP'); return false;" href="http://www.osti.gov/pages/biblio/1212467-shape-terrestrial-plasma-sheet-near-earth-magnetospheric-tail-imaged-interstellar-boundary-explorer"><span id="translatedtitle">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 PAGESBeta</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 (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('http://adsabs.harvard.edu/abs/2014SSRv..184...33W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014SSRv..184...33W"><span id="translatedtitle">Review of Solar Wind Entry into and Transport Within 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>Wing, S.; Johnson, J. R.; Chaston, C. C.; Echim, M.; Escoubet, C. P.; Lavraud, B.; Lemon, C.; Nykyri, K.; Otto, A.; Raeder, J.; Wang, C.-P.</p> <p>2014-11-01</p> <p>The <span class="hlt">plasma</span> <span class="hlt">sheet</span> is populated in part by the solar wind <span class="hlt">plasma</span>. Four solar entry mechanisms are examined: (1) double cusp or double lobe reconnection, (2) Kelvin-Helmholtz Instability (KHI), (3) Kinetic Alfvén waves (KAW), and (4) Impulsive Penetration. These mechanisms can efficiently fill the <span class="hlt">plasma</span> <span class="hlt">sheet</span> with cold dense ions during northward interplanetary magnetic field (IMF). The solar wind ions appear to have been heated upon entry along the <span class="hlt">plasma</span> <span class="hlt">sheet</span> dawn flank. The cold-component (solar wind origin) ion density is higher on the dawn flank than the dusk flank. The asymmetric evolution of the KAW and magnetic reconnection in association with the KHI at the dawn and dusk flank magnetopause may partly produce the dawn-dusk temperature and density asymmetries. Solar wind that crosses the magnetopause lowers the specific entropy ( s= p/ ? ? ) of the <span class="hlt">plasma</span> <span class="hlt">sheet</span> along the flanks. Subsequent transport of the cold ions from the flanks to the midnight meridian increases s by a factor of 5. T i , T e , s i , and s e increase when the solar wind particles are transported across the magnetopause, but T i / T e is roughly conserved. Within the magnetotail, E× B and curvature and gradient drifts play important roles in the <span class="hlt">plasma</span> transport and can explain the large features seen in the <span class="hlt">plasma</span> <span class="hlt">sheet</span>. Turbulence can also play a significant role, particularly in the cold <span class="hlt">plasma</span> transport from the flanks to the midnight meridian. Total entropy ( S= pV ? ) conservation provides important constraints on the <span class="hlt">plasma</span> <span class="hlt">sheet</span> transport, e.g., fast flows.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015ZNatA..70..244D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015ZNatA..70..244D"><span id="translatedtitle">Dense <span class="hlt">Electron</span>-Positron Pair <span class="hlt">Plasma</span> Expansion</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Djebli, Mourad</p> <p>2015-10-01</p> <p>The expansion of an <span class="hlt">electron</span>-positron <span class="hlt">plasma</span> is studied based on quantum hydrodynamical equations for two fluids. The quasi-neutral expansion, depicted through the quantum screening distance, is investigated numerically when the annealing processes is very slow. It was found that the pair <span class="hlt">plasma</span> behaves as a single fluid with a front expansion velocity that depends on the density and degenerate parameters. Faster expansion results from the existence of exchange-correlation potential, which is enhanced in high-density <span class="hlt">plasma</span>. The present investigation may be useful in understanding the expansion of a dense <span class="hlt">plasma</span> produced by the interaction between high-energy laser and solid targets.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015JGRA..120..187O','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015JGRA..120..187O"><span id="translatedtitle">Responses of different ion species to fast <span class="hlt">plasma</span> flows and local dipolarization 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>Ohtani, S.; Nosé, M.; Miyashita, Y.; Lui, A. T. Y.</p> <p>2015-01-01</p> <p>investigate the responses of different ion species (H+, He+, He++, and O+) to fast <span class="hlt">plasma</span> flows and local dipolarization in the <span class="hlt">plasma</span> <span class="hlt">sheet</span> in terms of energy density. We use energetic (9-210 keV) ion composition measurements made by the Geotail satellite at r = 10~31 RE. The results are summarized as follows: (1) whereas the O+-to-H+ ratio decreases with earthward flow velocity, it increases with tailward flow velocity with steeper Vx dependence for perpendicular flows than for parallel flows; (2) for fast earthward flows, the energy density of each ion species increases without any clear preference for heavy ions; (3) for fast tailward flows, the ion energy density initially increases, then it decreases to below the preceding levels except for O+; (4) the O+-to-H+ ratio does not increase through local dipolarization irrespective of dipolarization amplitude, background Bz, X distance, and Vx; (5) in general, the H+ and He++ ions behave similarly. Result (1) can be attributed to radial transport in the presence of the earthward gradient of the background O+-to-H+ ratio. Results (2) and (4) suggest that ion energization at local dipolarization is not mass dependent in the energy range of our interest because the ions are not magnetized irrespective of species. Result (3) can be attributed to the thinning of the <span class="hlt">plasma</span> <span class="hlt">sheet</span> and the preferable field-aligned escape of the H+ ions on the tailward side of the reconnection site. Result (5) suggests that the solar wind is the primary source of the high-energy H+ ions.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19910026465&hterms=Earth+layers&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D60%26Ntt%3DEarth%2527s%2Blayers','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19910026465&hterms=Earth+layers&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D60%26Ntt%3DEarth%2527s%2Blayers"><span id="translatedtitle">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/biblio/5502531','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/5502531"><span id="translatedtitle">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://www.osti.gov/scitech">SciTech Connect</a></p> <p>Schriver, D.; Ashour-Abdalla, M. ); Treumann, R.; Nakamura, M.; Kistler, L.M. )</p> <p>1990-10-01</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 an d then broadband electrostatic noise (BEN) immediately followed. Simultaneous with the onset of BEN, high energy earthward streaming proton beams at > 40 keV (> 2,700 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/biblio/6008309','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/6008309"><span id="translatedtitle">An <span class="hlt">electron</span> gun with a <span class="hlt">plasma</span> emitter</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Gruzdev, V.A.; Kreindel', Y.E.; Rempe, N.G.; Troyan, O.E.</p> <p>1985-01-01</p> <p>This paper describes a continuous-running <span class="hlt">electron</span> gun which has a <span class="hlt">plasma</span> emitter that is based on a reflective arc discharge in a cold hollow cathode, which provides an <span class="hlt">electron</span> beam carrying a current of 1 A. The beam current can be regulated smoothly from 1 mA to 1 A by varying the potential of the emitter cathode.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1995PhDT........50M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1995PhDT........50M"><span id="translatedtitle">Pressure Measurement Using a Pure <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>Moore, David Alan</p> <p>1995-01-01</p> <p>A pure <span class="hlt">electron</span> <span class="hlt">plasma</span> can be employed as a pressure sensing medium. The <span class="hlt">plasma</span> is confined in a Malmberg trap composed of a set of electrically isolated colinear cylinders embedded in a uniform axial magnetic field. Axial confinement of the <span class="hlt">plasma</span> is produced by negative voltages applied to the end cylinders relative to the middle cylinder(s). Radial confinement is produced by the magnetic field, and under the correct conditions is inversely proportional to the background neutral density. It is shown that a pure <span class="hlt">electron</span> <span class="hlt">plasma</span> could potentially serve as a primary vacuum standard for the 10^{-8} to 10 ^{-5} Pa pressure regime. In this regime, the <span class="hlt">plasma</span> can approach a quasi-thermal equilibrium state during its expansion toward the trap wall. While near thermal equilibrium, the rate of expansion of the <span class="hlt">plasma</span> as a function of helium pressure can be predicted from fundamental physical constants if the total charge, mean-square-radius, and temperature of the <span class="hlt">plasma</span> are known. The minimum pressure is determined by pressure -independent causes of <span class="hlt">plasma</span> expansion. Collisions between <span class="hlt">electrons</span> do not cause expansion because they conserve the mean-square-radius of the <span class="hlt">plasma</span>. Previous experiments, and the present results, indicate that azimuthal asymmetries in the confining fields are the predominant cause in Malmberg traps. However, resonant particle models used previously to explain the coupling of the asymmetries to the <span class="hlt">plasma</span> are inconsistent with new data on the empirical relation between <span class="hlt">plasma</span> properties and the pressure-independent expansion rate. The maximum pressure is determined by the requirement that the <span class="hlt">plasma</span> remain near thermal equilibrium during its expansion. A uniform temperature and a specific density profile characterize equilibrium, and they are produced and maintained by <span class="hlt">electron-electron</span> collisions. The transport due to collisions with the neutral gas can change both the density and temperature profiles. However, a new calculation shows that as long as the <span class="hlt">plasma</span> temperature remains uniform, collisions with neutrals will not perturb the equilibrium density profile. With its lower limit of 10^{ -8} Pa, this new type of pressure sensor would operate beyond the range of existing vacuum standards.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015APS..DMP.H3010C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015APS..DMP.H3010C"><span id="translatedtitle"><span class="hlt">Electron</span> Ion Collision Rates in Ultracold <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, Wei-Ting; Roberts, Jacob</p> <p>2015-05-01</p> <p>By using applying a short electric field pulse to an ultracold <span class="hlt">plasma</span>, it is possible to induce a collective oscillation of the <span class="hlt">electrons</span>. This oscillation will damp after the application of the electric field pulse. We have found that under certain achievable experimental conditions, this damping can be dominated by the <span class="hlt">electron</span>-ion collision rate. We have measured this damping rate experimentally under these conditions and thus can compare it to theoretical predictions. We will present our measurement technique and results. In addition, we will discuss extensions of this technique to measurements of <span class="hlt">electron</span> temperature, to investigating strong-coupling physics in the <span class="hlt">electron</span> component of an ultracold <span class="hlt">plasma</span>, and to measuring the <span class="hlt">electron</span>-ion collision rate when the <span class="hlt">electrons</span> are highly magnetized. Supported by the AFOSR.</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://hdl.handle.net/2060/19830026601','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19830026601"><span id="translatedtitle">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> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015JPlPh..81b3001N','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015JPlPh..81b3001N"><span id="translatedtitle">Ion and <span class="hlt">electron</span> heating during magnetic reconnection in weakly 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>Numata, Ryusuke; Loureiro, N. F.</p> <p>2015-04-01</p> <p>Magnetic reconnection and associated heating of ions and <span class="hlt">electrons</span> in strongly magnetized, weakly collisional <span class="hlt">plasmas</span> are studied by means of gyrokinetic simulations. It is shown that an appreciable amount of the released magnetic energy is dissipated to yield (irreversible) <span class="hlt">electron</span> and ion heating via phase mixing. <span class="hlt">Electron</span> heating is mostly localized to the magnetic island, not the current <span class="hlt">sheet</span>, and occurs after the dynamical reconnection stage. Ion heating is comparable to <span class="hlt">electron</span> heating only in high-? <span class="hlt">plasmas</span>, and results from both parallel and perpendicular phase mixing due to finite Larmor radius (FLR) effects; in space, ion heating is mostly localized to the interior of a secondary island (plasmoid) that arises from the instability of the current <span class="hlt">sheet</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/183241','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/183241"><span id="translatedtitle">Structured <span class="hlt">plasma</span> <span class="hlt">sheet</span> thinning observed by Galileo and 1984-129</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Reeves, G.D.; Belian, R.D.; Fritz, T.A.</p> <p>1993-12-01</p> <p>On December 8, 1990, the Galileo spacecraft used the Earth for a gravity assist on its way to Jupiter. Its trajectory was such that is crossed geosynchronous orbit at approximately local midnight between 1900 and 2000 UT. At the same time, spacecraft 1984-129 was also located at geosynchronous orbit near local midnight. Several flux dropout events were observed when the two spacecraft were in the near-Earth <span class="hlt">plasma</span> <span class="hlt">sheet</span> in the same local time sector. Flux dropout events are associated with <span class="hlt">plasma</span> <span class="hlt">sheet</span> thinning in the near-Earth tail during the growth phase of substorms. This period is unique in that Galileo provided a rapid radial profile of the near-Earth <span class="hlt">plasma</span> <span class="hlt">sheet</span> while 1984-129 provided an azimuthal profile. With measurements from these two spacecraft the authors can distinguish between spatial structures and temporal changes. Their observations confirm that the geosynchronous flux dropout events are consistent with <span class="hlt">plasma</span> <span class="hlt">sheet</span> thinning which changes the spacecraft`s magnetic connection from the trapping region to the more distant <span class="hlt">plasma</span> <span class="hlt">sheet</span>. However, for this period, thinning occurred on two spatial and temporal scales. The geosynchronous dropouts were highly localized phenomena of 30 min duration superimposed on a more global reconfiguration of the tail lasting approximately 4 hours. 28 refs., 10 figs.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19950046659&hterms=dropout&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D60%26Ntt%3Ddropout','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19950046659&hterms=dropout&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D60%26Ntt%3Ddropout"><span id="translatedtitle">Structured <span class="hlt">plasma</span> <span class="hlt">sheet</span> thinning observed by Galileo and 1984-129</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Reeves, G. D.; Belian, R. D.; Fritz, T. A.; Kivelson, M. G.; Mcentire, R. W.; Roelof, E. C.; Wilken, B.; Williams, D. J.</p> <p>1993-01-01</p> <p>On December 8, 1990, the Galileo spacecraft used the Earth for a gravity assist on its way to Jupiter. Its trajectory was such that it crossed geosynchronous orbit at approximately local midnight between 1900 and 2000 UT. At the same time, spacecraft 1984-129 was also located at geosynchronous orbit near local midnight. Several flux dropout events were observed when the two spacecraft were in the near-Earth <span class="hlt">plasma</span> <span class="hlt">sheet</span> in the same local time sector. Flux dropout events are associated with <span class="hlt">plasma</span> <span class="hlt">sheet</span> thinning in the near-profile of the near-Earth <span class="hlt">plasma</span> <span class="hlt">sheet</span> while 1984-129 provided an azimuthal profile. With measurements from these two spacecraft we can distinguish between spatial structures and temporal change. Our observations confirm that the geosynchronous flux dropout events are consistent with <span class="hlt">plasma</span> <span class="hlt">sheet</span> thinning which changes the spacecraft's magnetic connection from the trapping region to the more distant <span class="hlt">plasma</span> <span class="hlt">sheet</span>. However, for this period, thinning occurred on two spatial and temporal scales. The geosynchronous dropouts were highly localized phenomena of 30 min duration superimposed on a more global reconfiguration of the tail lasting approximately 4 hours.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/22402426','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/22402426"><span id="translatedtitle"><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 ?-, ?-, ?-, and 6,6,12-graphyne <span class="hlt">sheets</span> are compared and contrasted with those of graphene. ?-, ?-, and 6,6,12-graphynes, with direction dependent Dirac dispersions, have higher <span class="hlt">electronic</span> transmittance than graphene. ?-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. ?-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://adsabs.harvard.edu/abs/2013AASP....3...53S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013AASP....3...53S"><span id="translatedtitle">Vortex and ULF wave structures in the <span class="hlt">plasma</span> <span class="hlt">sheet</span> of the Earth magnetosphere</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Saliuk, D. A.; Agapitov, O. V.</p> <p>2013-08-01</p> <p>We studied the ULF wave packet propagation in the Earth <span class="hlt">plasma</span> <span class="hlt">sheet</span> making use of the magnetic field measurements from FGM detector and <span class="hlt">plasma</span> properties from CORRAL detector aboard the Interball-Tail spacecraft. The MHD vortex structures were observed simultaneously with the Pc5 ULF waves. The vortex spatial scale was found to be about 1200-3600 km and the velocity is 4-16 km/s transverse to the background magnetic field. We studied numerically the dynamics of the initial vortex perturbations in the <span class="hlt">plasma</span> system with parameters observed in the Earth <span class="hlt">plasma</span> <span class="hlt">sheet</span>. The system with the vector nonlinearity was processed making use of the full reduction scheme. The good agreement of the experimental value of the vortex structure velocity with numerical results was obtained. The velocity was found to be close to the local <span class="hlt">plasma</span> drift velocity.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010APS..DPPCP9013K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010APS..DPPCP9013K"><span id="translatedtitle">Axisymmetric Eigenmodes of Spheroidal Pure <span class="hlt">Electron</span> <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>Kawai, Yosuke; Saitoh, Haruhiko; Yoshida, Zensho; Kiwamoto, Yasuhito</p> <p>2010-11-01</p> <p>The axisymmetric electrostatic eigenmodes of spheroidal pure <span class="hlt">electron</span> <span class="hlt">plasmas</span> have been studied experimentally. It is confirmed that the observed spheroidal <span class="hlt">plasma</span> attains a theoretically expected equilibrium density distribution, with the exception of a low-density halo distribution surrounding the <span class="hlt">plasma</span>. When the eigenmode frequency observed for the <span class="hlt">plasma</span> is compared with the frequency predicted by the dispersion relation derived under ideal conditions wherein the temperature is zero and the boundary is located at an infinite distance from the <span class="hlt">plasma</span>, it is observed that the absolute value of the observed frequency is systematically higher than the theoretical prediction. Experimental examinations and numerical calculations indicate that the upward shift of the eigenmode frequency cannot be accounted for solely by the finite temperature effect, but is significantly affected by image charges induced on the conducting boundary and the resulting distortion of the density profile from the theoretical expectation.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015EGUGA..17.7964P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015EGUGA..17.7964P"><span id="translatedtitle">Fast magnetic reconnection in thin current <span class="hlt">sheets</span>: effects of different current profiles and <span class="hlt">electron</span> inertia in Ohm's law.</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Pucci, Fulvia; Del Sarto, Daniele; Tenerani, Anna; Velli, Marco</p> <p>2015-04-01</p> <p>By examining <span class="hlt">sheets</span> with thicknesses scaling as different powers of the Lundquist number S, we previously showed (Pucci and Velli, 2014) that the growth rate of the tearing mode increases as current <span class="hlt">sheets</span> thin and, once the inverse aspect ratio reaches a scaling a/L = S-1/3, the time-scale for the instability to develop becomes of the order of the Alfvén time. That means that a fast instability sets in well before Sweet-Parker type current <span class="hlt">sheets</span> can form. In addition, such an instability produces many islands in the <span class="hlt">sheet</span>, leading to fast nonlinear evolution and most probably a turbulent disruption of the <span class="hlt">sheet</span> itself. This has fundamental implications for magnetically driven reconnection throughout the corona, and in particular for coronal heating and the triggering of coronal mass ejections. Here we extend the study of reconnection instabilities to magnetic fields of grater complexity, displaying different current structures such as, for example, multiple or asymmetric current layers. We also consider the possibility of a ?' dependence on wave-number k-p for different values of p, studying analogies and variations of the trigger scaling relation a/L ~ S-1/3 with respect to the Harris current <span class="hlt">sheet</span> equilibrium. At large Lundquist numbers in typical Heliospheric <span class="hlt">plasmas</span> kinetic effects become more important in Ohm's law: we consider the effects of <span class="hlt">electron</span> skin depth reconnection, showing that we can define a trigger relation similar to the resistive case. The results are important to the transition to fast reconnection in the solar corona, solar wind, magnetosphere as well as laboratory <span class="hlt">plasmas</span>. F. Pucci and M. Velli, "Reconnection of quasi-singular current <span class="hlt">sheets</span>: the 'ideal" tearing mode" ApJ 780:L19, 2014.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015APS..DMP.D1026W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015APS..DMP.D1026W"><span id="translatedtitle"><span class="hlt">Electron</span> Forced Evaporative Cooling in Ultracold <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>Witte, Craig; Roberts, Jacob</p> <p>2015-05-01</p> <p>Ultracold <span class="hlt">plasmas</span> (UCPs) are formed by photoionizing a collection of laser cooled atoms. Once formed, these <span class="hlt">plasmas</span> expand, cooling over the course of their expansion. In theory, further cooling should be obtainable by forcibly inducing <span class="hlt">electron</span> evaporation through applying DC electric fields to extract <span class="hlt">electrons</span>. However, for many UCP parameters, UCP <span class="hlt">electrons</span> are not fully thermalized until very late in the expansion. This creates complications in analyzing the UCP. This problem can be remedied by creating the ultracold <span class="hlt">plasma</span> at substantially lower initial temperatures since thermalization rates increase with decreasing temperature. Unfortunately, traditional models of UCP dynamics tend to break down in cases of substantial non-neutrality when used in the limit of zero temperature. We have developed a theoretical model that calculates potential depth and expansion dynamics of non-neutral UCPs in the limit of zero temperature. Such a model will allow us to quantify the degree of cooling obtained by evaporation as measured experimentally. Supported by the AFOSR.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2004APS..DPPJP1083G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2004APS..DPPJP1083G"><span id="translatedtitle">Spectroscopic Diagnostics of Electric Fields in the <span class="hlt">Plasma</span> of 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>Gavrilenko, Valeri; Kyrie, Natalya P.; Frank, Anna G.; Oks, Eugene</p> <p>2004-11-01</p> <p>Spectroscopic measurements of electric fields (EFs) in current <span class="hlt">sheet</span> <span class="hlt">plasmas</span> were performed in the CS-3D device. The device is intended to study the evolution of current <span class="hlt">sheets</span> and the magnetic reconnection phenomena. We used the broadening of spectral lines (SLs) of HeII ions for diagnostics of EFs in the current <span class="hlt">sheet</span> middle plane, and the broadening of SLs of HeI atoms for detection of EFs in the current <span class="hlt">sheet</span> peripheral regions. For detection of EFs in current <span class="hlt">sheet</span> <span class="hlt">plasma</span>, we used SLs of HeII ions at 468.6; 320.3 and 656.0 nm, as well as SLs of HeI atoms at 667.8; 587.6; 492.2 and 447.1 nm. The latter two lines are of a special interest since their profiles include the dipole-forbidden components along with the allowed components. The experimental data have been analyzed by using the numerical calculations based on the Model Microfield Method. The maximum <span class="hlt">plasma</span> density in the middle of the <span class="hlt">sheet</span> was in the range (2-8) × 10^16 cm-3, the density in the peripheral regions was (1-2)×10^15 cm-3, and the strength of the quasi-one-dimensional anomalous electric fields in the peripheral regions reached the value of 100 kV/cm. Supported by CRDF, grant RU-P1-2594-MO-04; by the RFBR, grant 03-02-17282; and by the ISTC, project 2098.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015ApJ...807..159T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015ApJ...807..159T"><span id="translatedtitle">A Theoretical Model of a Thinning Current <span class="hlt">Sheet</span> in the Low-? <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>Takeshige, Satoshi; Takasao, Shinsuke; Shibata, Kazunari</p> <p>2015-07-01</p> <p>Magnetic reconnection is an important physical process in various explosive phenomena in the universe. In previous studies, it was found that fast reconnection takes place when the thickness of a current <span class="hlt">sheet</span> becomes on the order of a microscopic length such as the ion Larmor radius or the ion inertial length. In this study, we investigated the pinching process of a current <span class="hlt">sheet</span> by the Lorentz force in a low-? <span class="hlt">plasma</span> using one-dimensional magnetohydrodynamics (MHD) simulations. It is known that there is an exact self-similar solution for this problem that neglects gas pressure. We compared the non-linear MHD dynamics with the analytic self-similar solution. From the MHD simulations, we found that with the gas pressure included the implosion process deviates from the analytic self-similar solution as t\\to {t}0, where t0 is the explosion time when the thickness of a current <span class="hlt">sheet</span> of the analytic solution becomes 0. We also found that a pair of MHD fast-mode shocks is generated and propagates after the formation of the pinched current <span class="hlt">sheet</span> as t\\to {t}0. On the basis of the Rankine-Hugoniot relations, we derived the scaling law of the physical quantities with respect to the initial <span class="hlt">plasma</span> beta in the pinched current <span class="hlt">sheet</span>. Our study could help us estimate the physical quantities in the pinched current <span class="hlt">sheet</span> formed in a low-? <span class="hlt">plasma</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/5727707','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/5727707"><span id="translatedtitle">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://www.osti.gov/scitech">SciTech Connect</a></p> <p>Angelopoulos, V.; Kennel, C.F.; Coroniti, F.V.; Pellat, R.; Kivelson, M.G.; Walker, R.J.; Russell, C.T. ); Spence, H.E. ); Baumjohann, W. ); Feldman, W.C.; Gosling, J.T. )</p> <p>1993-08-20</p> <p>The authors model the properties of the ion flow in the high [beta][sub i], inner <span class="hlt">plasma</span> <span class="hlt">sheet</span>, during periods when geomagnetic activity is relatively low. They adopt the approach that the <span class="hlt">plasma</span> <span class="hlt">sheet</span> can be modeled in terms of bursty bulk flows (BBF's), irrespective of the auroral electrojet index. They then model the average flow pattern in the inner <span class="hlt">plasma</span> <span class="hlt">sheet</span> after the obvious BBF events have been removed from the data. The average flow properties found do not represent the instantaneous flow fields however, as there are large variances observed, even in the non-BBF part of the flow field. They are able to generate the same average flow patterns with their model, taking into account flow due to corotation, crossed field flow, and diamagnetic drift, as the T87 model.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19990103021&hterms=McCarthy&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3DMcCarthy%252C%2BR','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19990103021&hterms=McCarthy&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3DMcCarthy%252C%2BR"><span id="translatedtitle">Observations of Substorms from the Auroral Ionosphere to the Distant <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>Parks, G.; Brittnacher, M.; Chen, L.; Chua, D.; Elsen, R.; Fillingim, M.; McCarthy, M.; Germany, G.; Spann, J.</p> <p>1998-01-01</p> <p>We have been studying how substorms work by examining the global polar Ultraviolet Imager (UVI) images in correlation with observations from the ground, interplanetary space and the geomagnetic tail between 10-20 earth radii. One of the objectives of our study is to better understand the connection among many complex phenomena going on close to Earth and those in the distant <span class="hlt">plasma</span> <span class="hlt">sheet</span>. We have studied, for example, how the aurora[ and polar cap boundaries at different local times behave in relation to variations observed in the solar wind and <span class="hlt">plasma</span> <span class="hlt">sheet</span> during substorms. Preliminary results indicate that the polar cap and auroral oval boundaries expand and contract in a complicated but systematic way. These variations are correlated to solar wind parameters, and thinning and recovery phenomena in the <span class="hlt">plasma</span> <span class="hlt">sheet</span>. These results will be presented and interpreted in terms of directly driven and/or unloading substorm processes.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19900054441&hterms=mond&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3Dmond','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19900054441&hterms=mond&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3Dmond"><span id="translatedtitle">Ballooning instability of the earth's <span class="hlt">plasma</span> <span class="hlt">sheet</span> region in the presence of parallel flow</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Lakhina, G. S.; Hameiri, E.; Mond, M.</p> <p>1990-01-01</p> <p>Stability of the <span class="hlt">plasma</span> <span class="hlt">sheet</span> and <span class="hlt">plasma</span> <span class="hlt">sheet</span> boundary layer against the ballooning mode instability is investigated. The equilibrium state of a two-dimensional <span class="hlt">plasma</span> <span class="hlt">sheet</span> configuration with parallel sheared flow is modeled. This equilibrium is shown to be ballooning unstable when delta-W is not positive definite, where delta-W is the potential energy. The eigenmode structure of the ballooning mode is found by imposing the boundary conditions that the waves are totally reflected from the ionosphere, and that no waves are coming in from infinity. The eigenmode structure of the unstable balloning modes is highly oscillatory, extending beyond about 100 R(E). The ballooning modes are thus a possible candidate for explaining the MHD waves and other dynamical events observed in the magnetotail by ISEE 3 and other spacecraft.</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 id="translatedtitle">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://www.osti.gov/scitech/biblio/21386823','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/21386823"><span id="translatedtitle">Collisionless <span class="hlt">Plasma</span> Shocks in Striated <span class="hlt">Electron</span> Temperatures</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Guio, P.; Pecseli, H. L.</p> <p>2010-02-26</p> <p>The existence of low frequency waveguide modes of ion acoustic waves is demonstrated in magnetized <span class="hlt">plasmas</span> for <span class="hlt">electron</span> temperatures striated along the magnetic field lines. At higher frequencies, in a band between the ion cyclotron and the ion <span class="hlt">plasma</span> frequency, radiative modes develop and propagate obliquely to the field away from the striation. Arguments for the subsequent formation and propagation of electrostatic shock are presented and demonstrated numerically. For such <span class="hlt">plasma</span> conditions, the dissipation mechanism is the 'leakage' of the harmonics generated by the wave steepening.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2009PPCF...51c5012Z','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009PPCF...51c5012Z"><span id="translatedtitle">Current <span class="hlt">sheets</span> during spontaneous reconnection in a current-carrying 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>Zuin, M.; Vianello, N.; Spolaore, M.; Antoni, V.; Bolzonella, T.; Cavazzana, R.; Martines, E.; Serianni, G.; Terranova, D.</p> <p>2009-03-01</p> <p>An analysis of <span class="hlt">plasma</span> dynamics during impulsive magnetic reconnection events in the RFX-mod reversed field pinch (RFP) is performed by means of a large set of magnetic in-vessel coils and of an insertable edge probe, equipped with a matrix of electrostatic (Langmuir) and magnetic probes. It is observed that reconnection of field lines, which leads to a global reconfiguration of the magnetic topology (relaxation), is associated with the rapid formation of a strongly localized magnetic perturbation characterized by a main m = 0 periodicity, due to enhanced dynamo modes activity. Soon after its formation, the m = 0 perturbation is observed to move in the toroidal direction and is shown to correspond to a poloidal current <span class="hlt">sheet</span>, whose existence was predicted by three-dimensional MHD numerical simulations on RFP sustainment through magnetic reconnection processes. A reconstruction of the current density structure associated with the rotating magnetic perturbation is performed by means of the insertable probe, along with an investigation of the large induced modification of <span class="hlt">electron</span> temperature, density and <span class="hlt">plasma</span> velocity shear at the edge.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/991589','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/991589"><span id="translatedtitle"><span class="hlt">Electronic</span> and Magnetic Properties of Metal-Doped BN <span class="hlt">Sheet</span>: A First-Principles Study</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Zhou, Yungang; Xiao-Dong, J.; Wang, Zhiguo; Xiao, Haiyan Y.; Gao, Fei; Zu, Xiaotao T.</p> <p>2010-07-21</p> <p><span class="hlt">Electronic</span> and magnetic properties of BN <span class="hlt">sheet</span> doped with 3d transition metals (Fe, Co and Ni) have been investigated using ab initio calculations. Our calculations show many interesting physical properties in metal-doped BN <span class="hlt">sheet</span>. Fe-doped BN <span class="hlt">sheet</span> is a half-metal with the magnetic moment of 2.0 ?B, and Co-doped BN <span class="hlt">sheet</span> becomes a narrow-gap semiconductor with the magnetic moment of 1.0 ?B. However, no magnetic moment is induced on Ni-doped BN <span class="hlt">sheet</span>, which has the same band gap as pristine BN <span class="hlt">sheet</span>. Furthermore, Fe atom is easy to form isolated particle on BN <span class="hlt">sheet</span>, while Ni and Co atoms are likely to form <span class="hlt">sheet</span>-supported metal nanotemplate. These results are useful for spintronics application and could help in the development of magnetic nanotructures and metallic nanotemplate at room temperature.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=20060009468&hterms=current+events&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D60%26Ntt%3Dcurrent%2Bevents','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=20060009468&hterms=current+events&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D60%26Ntt%3Dcurrent%2Bevents"><span id="translatedtitle">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://www.osti.gov/scitech/biblio/5305565','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/5305565"><span id="translatedtitle">Ion distributions and flows in and near 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>Nakamura, M.; Paschmann, G.; Baumjohann, W.; Sckopke, N. )</p> <p>1992-02-01</p> <p>The authors have studied three-dimensional ion distribution functions obtained with high time resolution (every 4.5 s) in and near the <span class="hlt">plasma</span> <span class="hlt">sheet</span> boundary layer with the <span class="hlt">plasma</span> instrument on AMPTE IRM. This multicase study in the <span class="hlt">plasma</span> <span class="hlt">sheet</span> boundary layer reveals that at times, both an earthward and a tailward high-speed ion component are observed. Comparing these two components, the earthward components have the larger densities, while the tailward components have higher velocities. Typically, the distribution function changes from this two-component highly anisotropic character to generally isotropic as the spacecraft moves from the lobe, across the <span class="hlt">plasma</span> <span class="hlt">sheet</span> boundary layer, and into the central <span class="hlt">plasma</span> <span class="hlt">sheet</span>. The high-speed components often deviate from simple crescent-shaped distributions and exhibit significant structure. During disturbed times, substantial flows perpendicular to the magnetic field are observed. In several of the reported cases an additional cold ion component of comparable density was observed whose bulk velocity perpendicular to the magnetic field sometimes differed dramatically from that of the high-speed components. It is speculated that these differences might be a signature of gyrophase bunching.</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('http://adsabs.harvard.edu/abs/1982JQSRT..27..345M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1982JQSRT..27..345M"><span id="translatedtitle"><span class="hlt">Electronic</span> energy-levels in 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>More, R. M.</p> <p>1982-03-01</p> <p>Modern inertial-confinement fusion experiments subject matter to extreme physical conditions previously studied only in theoretical astrophysics. At very high <span class="hlt">plasma</span> density, atomic energy states are significantly altered by electric fields of neighboring ions and by free <span class="hlt">electrons</span>; the resulting phenomena of pressure ionization and continuum lowering may be analyzed with a sequence of models, each adding new subtleties to a complex picture. This paper develops a simple parameterization of pressure ionization, discusses limitations of the Debye-Huckel model for <span class="hlt">plasma</span> perturbations, and surveys an approximate description of X-ray spectra based on the WKB approximation. WKB theory leads to a simple derivation of the screened hydrogenic model for <span class="hlt">plasma</span> ionization and radiative properties. <span class="hlt">Electron</span> eigenvalues are obtained from the total ion energy in agreement with Koopman's theorem, and the representation of spectral terms is improved by a new set of screening coefficients.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/22403262','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/22403262"><span id="translatedtitle">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 ?} close to the speed of light c where the vortex size ? is on the order of the magnetic Debye length ?{sub B}=|B|/4?en 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 ?????{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/biblio/20860117','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/20860117"><span id="translatedtitle"><span class="hlt">Electron</span> acoustic solitons in a relativistic <span class="hlt">plasma</span> with nonthermal <span class="hlt">electrons</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Sahu, Biswajit; Roychoudhury, Rajkumar</p> <p>2006-07-15</p> <p><span class="hlt">Electron</span> acoustic solitary waves (EASWs) are studied using Sagdeev's pseudopotential technique for a <span class="hlt">plasma</span> comprising relativistic ions, cold relativistic <span class="hlt">electrons</span>, and nonthermal hot <span class="hlt">electrons</span>. The parametric range considered here is valid for the auroral zone. It is found that the present <span class="hlt">plasma</span> model supports EASWs having negative potential. It is seen that the relativistic effect significantly restricts the region of existence for solitary waves. The region of existence of solitary waves also depends crucially on {alpha}, the parameter that determines the population of the energetic nonthermal <span class="hlt">electrons</span>. For example, for {alpha}>0.18 with the soliton velocity 1.05 and u{sub 0c}/c=0.001, solitary wave solutions will not exist. We also find that for small values of {alpha}, solitary waves would exist for V<1.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19860057098&hterms=dropout&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D80%26Ntt%3Ddropout','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19860057098&hterms=dropout&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D80%26Ntt%3Ddropout"><span id="translatedtitle">Detailed observations of the <span class="hlt">plasma</span> <span class="hlt">sheet</span> during a substorm on April 24, 1979</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.; Fritz, T. A.; Birn, J.; Cooney, J.; Bame, S. J.</p> <p>1986-01-01</p> <p><span class="hlt">Plasma</span>, magnetic field, and energetic particle data obtained by ISEE 1 and 2 satellites for the April 24, 1979 substorm are studied in relation to the neutral line model and the boundary layer model. The ISEE 1 and 2 instruments and experiments utilized to collect the data are discussed. The major reconfiguration of the tail <span class="hlt">plasma</span> and magnetic field <span class="hlt">plasma</span> region, and the <span class="hlt">plasma</span> ion flows observed support the neutral line model for interpreting substorms. The <span class="hlt">plasma</span> ion distribution function and <span class="hlt">plasma</span> flow are examined. The region of lobe-<span class="hlt">plasma</span> <span class="hlt">sheet</span> interface referred to as the separatrix layer is identified. The differences in times of <span class="hlt">plasma</span> <span class="hlt">sheet</span> dropout and recovery, and absence or presence of flux anisotropies are investigated. Energetic particle measurements are analyzed to study the relationship between energetic ions and <span class="hlt">plasma</span> ions, and the velocity distributions. The data support the application of the neutral line model to the evaluation of substorms; however, the data are inconsistent with the boundary layer dynamics model.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19740053790&hterms=immersion&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D70%26Ntt%3Dimmersion','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19740053790&hterms=immersion&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D70%26Ntt%3Dimmersion"><span id="translatedtitle">Lunar dayside <span class="hlt">plasma</span> <span class="hlt">sheet</span> depletion - Inference from magnetic observations. [lunar immersion in geomagnetic tail</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Schubert, G.; Lichtenstein, B. R.; Russell, C. T.; Coleman, P. J., Jr.; Smith, B. F.; Colburn, D. S.; Sonett, C. P.</p> <p>1974-01-01</p> <p>The existence of a day-side lunar cavity in the <span class="hlt">plasma</span> <span class="hlt">sheet</span>, showing some depletion of <span class="hlt">plasma</span>, has been inferred from cavity-associated magnetic characteristics observed by orbital and surface lunar magnetometers. These characteristics include a day-side enhancement in the mean magnetic field and day-side levels of amplification of eddy current induced magnetic field fluctuations typical of cavity confinement.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/22086320','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/22086320"><span id="translatedtitle">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('http://arxiv.org/pdf/1209.5422.pdf','EPRINT'); return false;" href="http://arxiv.org/pdf/1209.5422.pdf"><span id="translatedtitle">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/eprints/">E-print Network</a></p> <p>Inoue, Tsuyoshi</p> <p>2012-01-01</p> <p>Linear stability of a current <span class="hlt">sheet</span> that is subject to an impulsive acceleration due to a shock passage is studied with the effect of guide magnetic field. We find that the current <span class="hlt">sheet</span> embedded in relativistically magnetized <span class="hlt">plasma</span> always shows a Richtmyer-Meshkov type instability, while it 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> that can induce so-called turbulent reconnection whose rate is essentially free from <span class="hlt">plasma</span> resistivity. Thus, the instability can be applied as a triggering mechanism of rapid magnetic energy release in variety of high-energy astrophysical phenomena such as pulsar wind nebulae, gamma-ray bursts, and active galactic nuclei, where the shock wave is supposed to play a crucial role.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012ApJ...760...43I','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012ApJ...760...43I"><span id="translatedtitle">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://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Inoue, Tsuyoshi</p> <p>2012-11-01</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('http://adsabs.harvard.edu/abs/1999APS..DPP.LI101Y','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1999APS..DPP.LI101Y"><span id="translatedtitle">Investigation of the Neutral <span class="hlt">Sheet</span> Profile during Magnetic Reconnection in a 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>Yamada, Masaaki</p> <p>1999-11-01</p> <p>Recent detailed data from laboratory <span class="hlt">plasma</span> experiments, satellite observations, theoretical analyses, and computer simulations have contributed significantly to the understanding of magnetic reconnection both in space and laboratory <span class="hlt">plasmas</span>. As magnetic field lines break and reconnect around the neutral region, a neutral <span class="hlt">sheet</span> current is generated. This current then heats the <span class="hlt">plasma</span>, and the opposing magnetic fields form a stationary equilibrium with the <span class="hlt">plasma</span> thermal pressure. This region is a focal point of reconnection since it requires proper treatment of local non-MHD effects in a <span class="hlt">plasma</span> which is highly conductive globally (with large Lundquist number S). Particularly, the profile of the neutral <span class="hlt">sheet</span> current is a very good indicator of the nature of reconnection. In this talk, we focus on the diverse and very intriguing features of the neutral <span class="hlt">sheet</span> in driven magnetic reconnection experiments on MRX(M. Yamada et al., Phys. Rev. Lett. 78), 3117 (1997); M. Yamada et al., Phys. <span class="hlt">Plasmas</span> 4, 1936 (1997)., which was built to investigate the fundamental physics of magnetic reconnection. The MHD approximation (S >> 1, ?i << L, v_A<< c) is satisfied globally in MRX <span class="hlt">plasmas</span>. In recent MRX experiments, the magnetic field profile of the neutral <span class="hlt">sheet</span> was measured precisely by magnetic probes with a spatial resolution of 0.25-0.5?_i, and B(x) data fit excellently to the Harris profile(E. G. Harris, Il Nuovo Cimento 23), 115 (1962); S. M. Mahajan, Phys. Fluids B 1, 43 (1989). B(x) ~ tanh[(x-x_0)/?], indicating the formation of a stable, axisymmetric neutral <span class="hlt">sheet</span>. The <span class="hlt">sheet</span> thickness ? is found to be equal to the ion skin depth c/?_pi, which is in very good agreement with recent numerical simulations(J. F. Drake et al., Geophys. Res. Lett. 24), 2921 (1997); D. Biskamp et al., Phys. Rev. Lett. 75, 3850 (1995); R. Horiuchi and T. Sato, Phys. <span class="hlt">Plasmas</span> 4, 277 (1997).. These data are also consistent with space observations both in the geotail region and the magnetopause. The detailed study of various additional local features of the reconnection region will be presented, along with further study of a generalized Sweet-Parker model(H. Ji et al., Phys. Rev. Lett. 80), 3256 (1998); H. Ji et al., Phys. <span class="hlt">Plasmas</span> 6, 1743 (1999)., measurements of enhanced resistivity, and studies of ion acceleration and heating. The relationship of MRX data to recent space observations and numerical simulations also will be discussed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014AGUFMSM13G..01Y','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014AGUFMSM13G..01Y"><span id="translatedtitle">On the Contribution of <span class="hlt">Plasma</span> <span class="hlt">Sheet</span> Bubbles to the Storm-Time Ring Current Injection</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Yang, J.; Toffoletto, F.; Wolf, R.; Sazykin, S. Y.</p> <p>2014-12-01</p> <p><span class="hlt">Plasma</span> <span class="hlt">sheet</span> transport is bimodal, consisting of both large-scale adiabatic convection and bursty flows. The bursty flows are associated with <span class="hlt">plasma</span> <span class="hlt">sheet</span> bubbles, containing lower entropy parameter PV5/3 than their neighbors. Although bubbles are major contributors to <span class="hlt">plasma</span> <span class="hlt">sheet</span> transport, it is still unclear whether they play a critical role in the formation of the storm-time ring current, since bubbles are much more frequently observed tailward of 10 Re in the magnetotail than inside geosynchronous orbit. In this paper, we use RCM-E, which combines the Rice Convection Model (RCM) with the magnetic field in force balance with particle pressure, to simulate an idealized geomagnetic storm. In the simulation, random bubble injections through the high latitude boundary are superimposed on a background of large-scale enhanced convection. We use the RCM-E solutions with the test particle approach to determine the relative roles of the three mechanisms of formation of the storm-time ring current: (1) energization of particles already trapped on closed drift trajectories; (2) localized injection of <span class="hlt">plasma</span> <span class="hlt">sheet</span> particles in flow channels associated with bubbles; (3) large-scale cross-tail particle transport from the tail into the inner magnetosphere under enhanced convection. We will discuss the fractional contribution of each of the three sources to the storm-time ring current and provide a picture of how each mechanism works.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://sprg.ssl.berkeley.edu/adminstuff/webpubs/2003_grl_SSC%203-1.pdf','EPRINT'); return false;" href="http://sprg.ssl.berkeley.edu/adminstuff/webpubs/2003_grl_SSC%203-1.pdf"><span id="translatedtitle">Sharp boundary between the inner magnetosphere and active outer <span class="hlt">plasma</span> <span class="hlt">sheet</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/eprints/">E-print Network</a></p> <p>California at Berkeley, University of</p> <p></p> <p>Sharp boundary between the inner magnetosphere and active outer <span class="hlt">plasma</span> <span class="hlt">sheet</span> V. A. Sergeev,1 J magnetosphere. It was successively crossed by the Cluster spacecraft in their pearl-on-string configuration near in the near tail. INDEX TERMS: 2740 Magnetospheric Physics: Magnetospheric configuration and dynamics; 2764</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://legolas.ece.wisc.edu/papers/Shen_1995.pdf','EPRINT'); return false;" href="http://legolas.ece.wisc.edu/papers/Shen_1995.pdf"><span id="translatedtitle">Properties of a vacuum ultraviolet laser created <span class="hlt">plasma</span> <span class="hlt">sheet</span> for a microwave reflector</span></a></p> <p><a target="_blank" href="http://www.osti.gov/eprints/">E-print Network</a></p> <p>Scharer, John E.</p> <p></p> <p>illustrate that a <span class="hlt">plasma</span> <span class="hlt">sheet</span> generated using a linear hollow cathode immersed in a magnetic field yields a much faster turn-on and turn-off time (7,,= 10 ns, rorr= 1 p s) compared with a hollow cathode system</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 id="translatedtitle">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://bp.pppl.gov/pub_report//2000/PPPL-3403.pdf','EPRINT'); return false;" href="http://bp.pppl.gov/pub_report//2000/PPPL-3403.pdf"><span id="translatedtitle">Confinement Of Pure Ion <span class="hlt">Plasma</span> In A Cylindrical Current <span class="hlt">Sheet</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/eprints/">E-print Network</a></p> <p></p> <p></p> <p>j ×B force. An equilibrium calculation using a relativistic, 1-D, cold-fluid model shows: the confine- ment of non-neutral ion <span class="hlt">plasmas</span> that are adequately dense for controlled thermonu- clear fusion limit? Conventional magnetic fusion devices contain quasi-neutral <span class="hlt">plasmas</span> in a toroidal or linear</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://legolas.ece.wisc.edu/papers/Kelly_1999.pdf','EPRINT'); return false;" href="http://legolas.ece.wisc.edu/papers/Kelly_1999.pdf"><span id="translatedtitle">Microwave reflections from a vacuum ultraviolet laser produced <span class="hlt">plasma</span> <span class="hlt">sheet</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/eprints/">E-print Network</a></p> <p>Scharer, John E.</p> <p></p> <p>is attractive because of its short turn on/off time, high reflectivity, and because it has negligible inertia close to that from a metal plate. The optically generated <span class="hlt">plasma</span> in this experiment has a high <span class="hlt">plasma</span> density making it useful for the reflection of higher frequency microwaves and has a turn-on time of on 10</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/944293','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/944293"><span id="translatedtitle"><span class="hlt">Electron</span> Scattering in Hot/Warm <span class="hlt">Plasmas</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Rozsnyai, B F</p> <p>2008-01-18</p> <p>Electrical and thermal conductivities are presented for aluminum, iron and copper <span class="hlt">plasmas</span> at various temperatures, and for gold between 15000 and 30000 Kelvin. The calculations are based on the continuum wave functions computed in the potential of the temperature and density dependent self-consistent 'average atom' (AA) model of the <span class="hlt">plasma</span>. The cross sections are calculated by using the phase shifts of the continuum <span class="hlt">electron</span> wave functions and also in the Born approximation. We show the combined effect of the thermal and radiative transport on the effective Rosseland mean opacities at temperatures from 1 to 1000 eV. Comparisons with low temperature experimental data are also presented.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.slac.stanford.edu/grp/arb/tn/arbvol1/ARDB079.pdf','EPRINT'); return false;" href="http://www.slac.stanford.edu/grp/arb/tn/arbvol1/ARDB079.pdf"><span id="translatedtitle"><span class="hlt">Electron</span>-hose instability in an annular <span class="hlt">plasma</span> sheath</span></a></p> <p><a target="_blank" href="http://www.osti.gov/eprints/">E-print Network</a></p> <p></p> <p></p> <p><span class="hlt">Electron</span>-hose instability in an annular <span class="hlt">plasma</span> sheath David H. Whittum Stanford Linear Accelerator Center Stanford University, Stanford CA 94309 (Received ) A relativistic <span class="hlt">electron</span> beam propagating through an annular <span class="hlt">plasma</span> sheath is subject to a transverse <span class="hlt">plasma-electron</span> coupled electrostatic</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 id="translatedtitle">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://ntrs.nasa.gov/search.jsp?R=19850051326&hterms=electron&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DTitle%26N%3D0%26No%3D50%26Ntt%3Delectron','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19850051326&hterms=electron&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DTitle%26N%3D0%26No%3D50%26Ntt%3Delectron"><span id="translatedtitle">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://ntrs.nasa.gov/search.jsp?R=20080037619&hterms=Fgm&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3DFgm','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=20080037619&hterms=Fgm&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3DFgm"><span id="translatedtitle">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> </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/2014JPhCS.518a2016K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014JPhCS.518a2016K"><span id="translatedtitle">Control of the area irradiated by the <span class="hlt">sheet</span>-type <span class="hlt">plasma</span> jet in 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>Kawasaki, T.; Kawano, K.; Mizoguchi, H.; Yano, Y.; Yamashita, K.; Sakai, M.; Uchida, G.; Koga, K.; Shiratani, M.</p> <p>2014-06-01</p> <p>The sterilization effect has been investigated using the <span class="hlt">sheet</span>-type <span class="hlt">plasma</span> jet, which was generated between asymmetric electrodes with dielectric plates in gas flow released into the atmospheric air. In this paper, it is indicated there is a possibility that the <span class="hlt">plasma</span> jet irradiation area can be controlled only by supplied gases without changing a generator structure. The irradiation area control was evaluated from both the sterilization area size and the oxidizing substances distribution. The oxidizing substance distribution was obtained using the chemical reagent prepared in our laboratory. The width of the <span class="hlt">sheet</span>-type <span class="hlt">plasma</span> jet was able to be controlled by N2 addition into He gas. As a result, the width of the sterilization area was able to be controlled within the range of 2 to 12 mm at a constant height without changing the generator structure. On the other hand, the evaluation from the oxidizing substances distribution indicated that the irradiation area cannot be controlled in one direction.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://nano.iphy.ac.cn/N04-en/papers/NO4_papers%20all%20pdf/JPCC116(2012)18202.pdf','EPRINT'); return false;" href="http://nano.iphy.ac.cn/N04-en/papers/NO4_papers%20all%20pdf/JPCC116(2012)18202.pdf"><span id="translatedtitle">Boron <span class="hlt">Sheet</span> Adsorbed on Metal Surfaces: Structures and <span class="hlt">Electronic</span> L. Z. Zhang,</span></a></p> <p><a target="_blank" href="http://www.osti.gov/eprints/">E-print Network</a></p> <p>Gao, Hongjun</p> <p></p> <p>Boron <span class="hlt">Sheet</span> Adsorbed on Metal Surfaces: Structures and <span class="hlt">Electronic</span> Properties L. Z. Zhang, Q. B. Yan of monolayer boron <span class="hlt">sheets</span> (BSs) on different metal (Mg, Al, Ti, Au, and Ag) surfaces. We find that, when according to the interactions between boron and metal: (1) h-BS on Mg(0001), Al(111), or Ti(0001) shows</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015JGRA..120.7416Y','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015JGRA..120.7416Y"><span id="translatedtitle">On the contribution of <span class="hlt">plasma</span> <span class="hlt">sheet</span> bubbles to the storm time ring current</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Yang, Jian; Toffoletto, Frank R.; Wolf, Richard A.; Sazykin, Stanislav</p> <p>2015-09-01</p> <p>Particle injections occur frequently inside 10 Re during geomagnetic storms. They are commonly associated with bursty bulk flows or <span class="hlt">plasma</span> <span class="hlt">sheet</span> bubbles transported from the tail to the inner magnetosphere. Although observations and theoretical arguments have suggested that they may have an important role in storm time dynamics, this assertion has not been addressed quantitatively. In this paper, we investigate which process is dominant for the storm time ring current buildup: large-scale enhanced convection or localized bubble injections. We use the Rice Convection Model-Equilibrium (RCM-E) to model a series of idealized storm main phases. The boundary conditions at 14-15 Re on the nightside are adjusted to randomly inject bubbles to a degree roughly consistent with observed statistical properties. A test particle tracing technique is then used to identify the source of the ring current <span class="hlt">plasma</span>. We find that the contribution of <span class="hlt">plasma</span> <span class="hlt">sheet</span> bubbles to the ring current energy increases from ~20% for weak storms to ~50% for moderate storms and levels off at ~61% for intense storms, while the contribution of trapped particles decreases from ~60% for weak storms to ~30% for moderate and ~21% for intense storms. The contribution of nonbubble <span class="hlt">plasma</span> <span class="hlt">sheet</span> flux tubes remains ~20% on average regardless of the storm intensity. Consistent with previous RCM and RCM-E simulations, our results show that the mechanisms for <span class="hlt">plasma</span> <span class="hlt">sheet</span> bubbles enhancing the ring current energy are (1) the deep penetration of bubbles and (2) the bulk <span class="hlt">plasma</span> pushed ahead of bubbles. Both the bubbles and the <span class="hlt">plasma</span> pushed ahead typically contain larger distribution functions than those in the inner magnetosphere at quiet times. An integrated effect of those individual bubble injections is the gradual enhancement of the storm time ring current. We also make two predictions testable against observations. First, fluctuations over a time scale of 5-20 min in the <span class="hlt">plasma</span> distributions and electric field can be seen in the central ring current region for the storm main phase. We find that the <span class="hlt">plasma</span> pressure and the electric field EY there vary over about 10%-30% and 50%-300% of the background values, respectively. Second, the maximum <span class="hlt">plasma</span> pressure and magnetic field depression in the central ring current region during the main phase are well correlated with the Dst index.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014AGUFMSM23B4214T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014AGUFMSM23B4214T"><span id="translatedtitle">THEMIS observations of <span class="hlt">plasma</span> bubbles associated with energetic <span class="hlt">electron</span> acceleration in the inner magnetosphere</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Tang, C. L.</p> <p>2014-12-01</p> <p>Using Time History of Events and Macroscale Interactions during Substorms (THEMIS) observations, we study the <span class="hlt">plasma</span> bubbles associated with a transient increase of the magnetic field Bz component in the inner magnetosphere during the substorm expansion phase. Except small electric field, the main characteristics of these <span class="hlt">plasma</span> bubbles are similar with those associated with dipolarization front (DF) in the mid-tail and near-Earth tail. Based on the different dipolarization of the magnetic field, we defined the <span class="hlt">plasma</span> bubble with no dipolarization phenomenon as "no dipolarization bubble" (NDB), the <span class="hlt">plasma</span> bubble with dipolarization phenomenon as "dipolarization bubble" (DB). We find that these <span class="hlt">plasma</span> bubbles in the inner magnetosphere accompany the energetic <span class="hlt">electron</span> acceleration. Some pancake-type distributions of energetic <span class="hlt">electrons</span> inside the NDB in the inner magnetosphere are caused by drift betatron acceleration, other pancake-type distributions of energetic <span class="hlt">electrons</span> inside the NDB are caused by gyrobetatron acceleration. For the DB in the inner magnetosphere, the cigar-type distributions of energetic <span class="hlt">electrons</span> are attributed to Fermi acceleration. Our observations suggest that the inner magnetosphere may be a very important source region for energetic <span class="hlt">electrons</span>, except for a reconnection site in the mid-tail and the <span class="hlt">plasma</span> <span class="hlt">sheet</span> in the near-Earth tail.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/22269257','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/22269257"><span id="translatedtitle"><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://www.osti.gov/scitech/biblio/1012877','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/1012877"><span id="translatedtitle"><span class="hlt">Electronic</span> and magnetic properties of substituted BN <span class="hlt">sheets</span>: A density functional theory study</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Zhou, Yungang; Yang, Ping; Wang, Zhiguo; Zu, Xiaotao T.; Xiao, Hai Yan; Sun, Xin; Khaleel, Mohammad A.; Gao, Fei</p> <p>2011-04-15</p> <p>Using density functional calculations, we investigate the geometries, <span class="hlt">electronic</span> structures and magnetic properties of hexagonal BN <span class="hlt">sheets</span> with 3d transition metal (TM) and nonmetal atoms embedded in three types of vacancies: VB, VN, and VB+N. We show that some embedded configurations, except TM atoms in VN vacancy, are stable in BN <span class="hlt">sheet</span> and yield interesting phenomena. For instance, the band gaps and magnetic moments of BN <span class="hlt">sheet</span> can be tuned depending on the embedded dopant species and vacancy type. In particular, embedment such as Cr in VB+N, Co in VB, and Ni in VB leads to half-metallic BN <span class="hlt">sheets</span> interesting for spin filter applications. From the investigation of Mn-chain (CMn) embedments, a regular 1D structure can be formed in BN <span class="hlt">sheet</span> as an <span class="hlt">electron</span> waveguide, a metal nanometer wire with a single atom thickness.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4451805','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4451805"><span id="translatedtitle">Theoretical predictions on the <span class="hlt">electronic</span> structure and charge carrier mobility in 2D Phosphorus <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>Xiao, Jin; Long, Mengqiu; Zhang, Xiaojiao; Ouyang, Jun; Xu, Hui; Gao, Yongli</p> <p>2015-01-01</p> <p>We have investigated the <span class="hlt">electronic</span> structure and carrier mobility of four types of phosphorous monolayer <span class="hlt">sheet</span> (?-P, ?-P,?-P and ?-P) using density functional theory combined with Boltzmann transport method and relaxation time approximation. It is shown that ?-P, ?-P and ?-P are indirect gap semiconductors, while ?-P is a direct one. All four <span class="hlt">sheets</span> have ultrahigh carrier mobility and show anisotropy in-plane. The highest mobility value is ~3?×?105?cm2V?1s?1, which is comparable to that of graphene. Because of the huge difference between the hole and <span class="hlt">electron</span> mobilities, ?-P, ?-P and ?-P <span class="hlt">sheets</span> can be considered as n-type semiconductors, and ?-P <span class="hlt">sheet</span> can be considered as a p-type semiconductor. Our results suggest that phosphorous monolayer <span class="hlt">sheets</span> can be considered as a new type of two dimensional materials for applications in optoelectronics and nanoelectronic devices. PMID:26035176</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19720058741&hterms=depression+effects&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3Ddepression%2Beffects','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19720058741&hterms=depression+effects&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3Ddepression%2Beffects"><span id="translatedtitle">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('http://www.osti.gov/scitech/servlets/purl/896940','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/896940"><span id="translatedtitle">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://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="http://ntrs.nasa.gov/search.jsp?R=19950011848&hterms=irm&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3Dirm"><span id="translatedtitle">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://www.osti.gov/scitech/servlets/purl/5916052','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/5916052"><span id="translatedtitle">Free <span class="hlt">electron</span> laser with small period wiggler and <span class="hlt">sheet</span> <span class="hlt">electron</span> beam: A study of the feasibility of operation at 300 GHz with 1 MW CW output power</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Booske, J.H.; Granatstein, V.L.; Antonsen, T.M. Jr.; Destler, W.W.; Finn, J.; Latham, P.E.; Levush, B.; Mayergoyz, I.D.; Radack, D.; Rodgers, J.</p> <p>1988-01-01</p> <p>The use of a small period wiggler (/ell//sub ..omega../ < 1 cm) together with a <span class="hlt">sheet</span> <span class="hlt">electron</span> beam has been proposed as a low cost source of power for <span class="hlt">electron</span> cyclotron resonance heating (ECRH) in magnetic fusion <span class="hlt">plasmas</span>. Other potential applications include space-based radar systems. We have experimentally demonstrated stable propagation of a <span class="hlt">sheet</span> beam (18 A. 1 mm /times/ 20 mm) through a ten-period wiggler electromagnet with peak field of 1.2 kG. Calculation of microwave wall heating and pressurized water cooling have also been carried out, and indicate the feasibility of operating a near-millimeter, <span class="hlt">sheet</span> beam FEL with an output power of 1 MW CW (corresponding to power density into the walls of 2 kW/cm/sup 2/). Based on these encouraging results, a proof-of-principle experiment is being assembled, and is aimed at demonstrating FEL operating at 120 GHz with 300 kW output power in 1 ..mu..s pulses: <span class="hlt">electron</span> energy would be 410 keV. Preliminary design of a 300 GHz 1 MW FEL with an untapered wiggler is also presented. 10 refs., 5 figs., 3 tabs.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.engr.colostate.edu/ece/faculty/rocca/pdf/journals/ECEjjr00090.pdf','EPRINT'); return false;" href="http://www.engr.colostate.edu/ece/faculty/rocca/pdf/journals/ECEjjr00090.pdf"><span id="translatedtitle">Etching of polycrystalline diamond films by <span class="hlt">electron</span> beam assisted <span class="hlt">plasma</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/eprints/">E-print Network</a></p> <p>Rocca, Jorge J.</p> <p></p> <p>, the <span class="hlt">plasma</span> sheath was curved along the cathode surface, which resulted in a self-focused <span class="hlt">electron</span> beam are accelerated in the <span class="hlt">plasma</span> sheath region between the cathode and the negative glow discharge region. AfterEtching of polycrystalline diamond films by <span class="hlt">electron</span> beam assisted <span class="hlt">plasma</span> Koji Kobashi, Shigeaki</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 id="translatedtitle">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://www.osti.gov/doepatents/biblio/874126','DOE-PATENT-XML'); return false;" href="http://www.osti.gov/doepatents/biblio/874126"><span id="translatedtitle"><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 (Santa Fe, NM); Walter, Kevin Carl (Los Alamos, NM)</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://ntrs.nasa.gov/search.jsp?R=19900036674&hterms=dropout&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D70%26Ntt%3Ddropout','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19900036674&hterms=dropout&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D70%26Ntt%3Ddropout"><span id="translatedtitle">Extreme energetic particle decreases near geostationary orbit - A manifestation of current diversion within 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>Baker, D. N.; Mcpherron, R. L.</p> <p>1990-01-01</p> <p>A qualitative model of cross-tail current flow is considered. It is suggested that when magnetic reconnection begins, the current effectively flows across the <span class="hlt">plasma</span> <span class="hlt">sheet</span> both earthward and tailward of the disruption region near the neutral line. It is shown that an enhanced cross-tail current earthward of this region would thin the <span class="hlt">plasma</span> <span class="hlt">sheet</span> substantially due to the magnetic pinch effect. The results explain the very taillike field and extreme particle dropouts often seen late in substorm growth phases.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/5702177','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/5702177"><span id="translatedtitle">Flute-interchange stability in a hot <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>Dominguez, R.R.</p> <p>1980-01-01</p> <p>Several topics in the kinetic stability theory of flute-interchange modes in a hot <span class="hlt">electron</span> <span class="hlt">plasma</span> are discussed. The stability analysis of the hot-<span class="hlt">electron</span>, curvature-driven flute-interchange mode, previously performed in a slab geometry, is extended to a cylindrical <span class="hlt">plasma</span>. The cold <span class="hlt">electron</span> concentration necessary for stability differs substantially from previous criteria. The inclusion of a finite temperature background <span class="hlt">plasma</span> in the stability analysis results in an ion curvature-driven flute-interchange mode which may be stabilized by either hot-<span class="hlt">electron</span> diamagnetic effects, hot-<span class="hlt">electron</span> <span class="hlt">plasma</span> density, or finite (ion) Larmor radius effects.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/22300126','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/22300126"><span id="translatedtitle">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('http://adsabs.harvard.edu/abs/2014PhPl...21e2115M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014PhPl...21e2115M"><span id="translatedtitle">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://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Mbuli, L. N.; Maharaj, S. K.; Bharuthram, R.</p> <p>2014-05-01</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('http://adsabs.harvard.edu/abs/2015ANSNN...6d5009N','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015ANSNN...6d5009N"><span id="translatedtitle">Theory of photon–<span class="hlt">electron</span> interaction in single-layer 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>Nguyen, Bich Ha; Hieu Nguyen, Van; Bui, Dinh Hoi; Thu Phuong Le, Thi</p> <p>2015-12-01</p> <p>The purpose of this work is to elaborate the quantum theory of photon–<span class="hlt">electron</span> interaction in a single-layer graphene <span class="hlt">sheet</span>. Since the light source must be located outside the extremely thin graphene <span class="hlt">sheet</span>, the problem must be formulated and solved in the three-dimensional physical space, in which the graphene <span class="hlt">sheet</span> is a thin plane layer. It is convenient to use the orthogonal coordinate system in which the xOy coordinate plane is located in the middle of the plane graphene <span class="hlt">sheet</span> and therefore the Oz axis is perpendicular to this plane. For the simplicity we assume that the quantum motions of <span class="hlt">electron</span> in the directions parallel to the coordinate plane xOy and that along the direction of the Oz axis are independent. Then we have a relatively simple formula for the overall Hamiltonian of the <span class="hlt">electron</span> gas in the graphene <span class="hlt">sheet</span>. The explicit expressions of the wave functions of the charge carriers are easily derived. The <span class="hlt">electron</span>–hole formalism is introduced, and the Hamiltonian of the interaction of some external quantum electromagnetic field with the charge carriers in the graphene <span class="hlt">sheet</span> is established. From the expression of this interaction Hamiltonian it is straightforward to derive the matrix elements of photons with the Dirac fermion–Dirac hole pairs as well as with the <span class="hlt">electrons</span> in the quantum well along the direction of the Oz axis.</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 id="translatedtitle">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 that accompanies the radial compression of the <span class="hlt">plasma</span> in conical theta pinches.</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('http://adsabs.harvard.edu/abs/2015TESS....120310M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015TESS....120310M"><span id="translatedtitle">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('http://adsabs.harvard.edu/abs/2015JGRA..120.3415K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015JGRA..120.3415K"><span id="translatedtitle">Distribution of energetic oxygen and hydrogen in the 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>Kronberg, E. A.; Grigorenko, E. E.; Haaland, S. E.; Daly, P. W.; Delcourt, D. C.; Luo, H.; Kistler, L. M.; Dandouras, I.</p> <p>2015-05-01</p> <p>The spatial distributions of different ion species are useful indicators for <span class="hlt">plasma</span> <span class="hlt">sheet</span> dynamics. In this statistical study based on 7 years of Cluster observations, we establish the spatial distributions of oxygen ions and protons at energies from 274 to 955 keV, depending on geomagnetic and solar wind (SW) conditions. Compared with protons, the distribution of energetic oxygen has stronger dawn-dusk asymmetry in response to changes in the geomagnetic activity. When the interplanetary magnetic field (IMF) is directed southward, the oxygen ions show significant acceleration in the tail <span class="hlt">plasma</span> <span class="hlt">sheet</span>. Changes in the SW dynamic pressure (Pdyn) affect the oxygen and proton intensities in the same way. The energetic protons show significant intensity increases at the near-Earth duskside during disturbed geomagnetic conditions, enhanced SW Pdyn, and southward IMF, implying there location of effective inductive acceleration mechanisms and a strong duskward drift due to the increase of the magnetic field gradient in the near-Earth tail. Higher losses of energetic ions are observed in the dayside <span class="hlt">plasma</span> <span class="hlt">sheet</span> under disturbed geomagnetic conditions and enhanced SW Pdyn. These observations are in agreement with theoretical models.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://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="http://ntrs.nasa.gov/search.jsp?R=19930072240&hterms=irm&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3Dirm"><span id="translatedtitle">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://ntrs.nasa.gov/search.jsp?R=19860057099&hterms=dropout&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D80%26Ntt%3Ddropout','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19860057099&hterms=dropout&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D80%26Ntt%3Ddropout"><span id="translatedtitle">A statistical study of <span class="hlt">plasma</span> <span class="hlt">sheet</span> dynamics using ISEE 1 and 2 energetic particle flux data</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Dandouras, J.; Reme, H.; Saint-Marc, A.; Sauvaud, J. A.; Parks, G. K.</p> <p>1986-01-01</p> <p><span class="hlt">Plasma</span> <span class="hlt">sheet</span> dynamics during substorms are studied by analyzing 461 cases of transient dropout events of the 1.5 and 6-keV particle fluxes detected by ISEE 1 and 2 satellites. The instruments for detecting low- and high-energy particles are described. The spatial distribution of flux dropout events, and the events' relationship to magnetospheric activity level are examined. Substorm events without observed flux dropout events are investigated. The data reveal that the flux dropout distribution is isotropic, between 12-23 earth radii, and is present in the entire nightside <span class="hlt">plasma</span> <span class="hlt">sheet</span>; and the substorms without flux dropout are more frequent near earth and magnetospheric flanks. It is observed that tailward of 12 earth radii the flux dropout events and substorms without flux dropout are similar. The Chao et al. (1977) MHD rarefaction wave propagation model and the Hones (1973, 1980) near-tail, X-type magnetic neutral line formation model are discussed and compared to the experimental data. It is noted that neither model explains the <span class="hlt">plasma</span> <span class="hlt">sheet</span> dynamics observed.</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 id="translatedtitle"><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('http://sprg.ssl.berkeley.edu/adminstuff/webpubs/2000_pop_2987.pdf','EPRINT'); return false;" href="http://sprg.ssl.berkeley.edu/adminstuff/webpubs/2000_pop_2987.pdf"><span id="translatedtitle"><span class="hlt">Electron</span>-acoustic solitons in an <span class="hlt">electron</span>-beam <span class="hlt">plasma</span> system Matthieu Berthomiera)</span></a></p> <p><a target="_blank" href="http://www.osti.gov/eprints/">E-print Network</a></p> <p>California at Berkeley, University of</p> <p></p> <p><span class="hlt">Electron</span>-acoustic solitons in an <span class="hlt">electron</span>-beam <span class="hlt">plasma</span> system Matthieu Berthomiera) Swedish Physics, Uppsala, Sweden Received 18 November 1999; accepted 16 March 2000 <span class="hlt">Electron</span>-acoustic solitons exist in a two <span class="hlt">electron</span> temperature <span class="hlt">plasma</span> with ``cold'' and ``hot'' <span class="hlt">electrons</span> and take the form</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2005NIMPB.241..854H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2005NIMPB.241..854H"><span id="translatedtitle">Non-vacuum <span class="hlt">electron</span> beam welding through a <span class="hlt">plasma</span> window</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Hershcovitch, Ady</p> <p>2005-12-01</p> <p>The <span class="hlt">plasma</span> window is a novel apparatus that utilizes a stabilized <span class="hlt">plasma</span> arc as interface between vacuum and atmosphere or pressurized targets without solid material. Additionally, the <span class="hlt">plasma</span> has a lensing effect on charged particles. This feature enables beam focusing to very small spot sizes and overcoming beam dispersion due to scattering by atmospheric atoms and molecules. Recently, the <span class="hlt">plasma</span> window was mated to a conventional <span class="hlt">electron</span> beam welder. And, <span class="hlt">electron</span> beam welding in atmosphere was accomplished with <span class="hlt">electron</span> beams of unprecedented low power and energy. Weld quality for the non-vacuum <span class="hlt">plasma</span> window <span class="hlt">electron</span> beam welding approached the quality of in-vacuum <span class="hlt">electron</span> beam welding. Indications exist that <span class="hlt">electron</span> beam attenuation is lower than theoretically predicted. Results suggest that air boring was achieved with 6-15 mA, 90-150 keV <span class="hlt">electron</span> beams compared to the previously used kA, MeV <span class="hlt">electron</span> beams. It may explain the better than expected welding results.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19920042037&hterms=plasma+antenna&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D70%26Ntt%3Dplasma%2Bantenna','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19920042037&hterms=plasma+antenna&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D70%26Ntt%3Dplasma%2Bantenna"><span id="translatedtitle">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://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Jensen, Mark D.; Baker, Kay D.</p> <p>1992-01-01</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.</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 id="translatedtitle">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> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/26465570','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/26465570"><span id="translatedtitle"><span class="hlt">Electron</span> energy distribution in a dusty <span class="hlt">plasma</span>: Analytical approach.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Denysenko, I B; Kersten, H; Azarenkov, N A</p> <p>2015-09-01</p> <p>Analytical expressions describing the <span class="hlt">electron</span> energy distribution function (EEDF) in a dusty <span class="hlt">plasma</span> are obtained from the homogeneous Boltzmann equation for <span class="hlt">electrons</span>. The expressions are derived neglecting <span class="hlt">electron-electron</span> collisions, as well as transformation of high-energy <span class="hlt">electrons</span> into low-energy <span class="hlt">electrons</span> at inelastic <span class="hlt">electron</span>-atom collisions. At large <span class="hlt">electron</span> energies, the quasiclassical approach for calculation of the EEDF is applied. For the moderate energies, we account for inelastic <span class="hlt">electron</span>-atom collisions in the dust-free case and both inelastic <span class="hlt">electron</span>-atom and <span class="hlt">electron</span>-dust collisions in the dusty <span class="hlt">plasma</span> case. Using these analytical expressions and the balance equation for dust charging, the <span class="hlt">electron</span> energy distribution function, the effective <span class="hlt">electron</span> temperature, the dust charge, and the dust surface potential are obtained for different dust radii and densities, as well as for different <span class="hlt">electron</span> densities and radio-frequency (rf) field amplitudes and frequencies. The dusty <span class="hlt">plasma</span> parameters are compared with those calculated numerically by a finite-difference method taking into account <span class="hlt">electron-electron</span> collisions and the transformation of high-energy <span class="hlt">electrons</span> at inelastic <span class="hlt">electron</span>-neutral collisions. It is shown that the analytical expressions can be used for calculation of the EEDF and dusty <span class="hlt">plasma</span> parameters at typical experimental conditions, in particular, in the positive column of a direct-current glow discharge and in the case of an rf <span class="hlt">plasma</span> maintained by an electric field with frequency f=13.56MHz. PMID:26465570</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015AnGeo..33..845M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015AnGeo..33..845M"><span id="translatedtitle">Solar-wind control of <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>Myllys, M.; Kilpua, E.; Pulkkinen, T.</p> <p>2015-07-01</p> <p>The purpose of this study is to quantify how solar-wind conditions affect the energy and <span class="hlt">plasma</span> transport in the geomagnetic tail and its large-scale configuration. To identify the role of various effects, the magnetospheric data were sorted according to different solar-wind <span class="hlt">plasma</span> and interplanetary magnetic field (IMF) parameters: speed, dynamic pressure, IMF north-south component, epsilon parameter, Auroral Electrojet (AE) index and IMF ultra low-frequency (ULF) fluctuation power. We study variations in the average flow speed pattern and the occurrence rate of fast flow bursts in the magnetotail during different solar-wind conditions using magnetospheric data from five Time History of Events and Macroscale Interactions during Substorms (THEMIS) mission spacecraft and solar-wind data from NASA's OMNIWeb. The time interval covers the years from 2008 to 2011 during the deep solar minimum between cycles 23 and 24 and the relatively quiet rising phase of cycle 24. Hence, we investigate magnetospheric processes and solar-wind-magnetospheric coupling during a relatively quiet state of the magnetosphere. We show that the occurrence rate of the fast (|Vtail| > 100 km s-1) sunward flows varies under different solar-wind conditions more than the occurrence of the fast tailward flows. The occurrence frequency of the fast tailward flows does not change much with the solar-wind conditions. We also note that the sign of the IMF BZ has the most visible effect on the occurrence rate and pattern of the fast sunward flows. High-speed flow bursts are more common during the slow than fast solar-wind conditions.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2008PFR.....2...45S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2008PFR.....2...45S"><span id="translatedtitle">Long-Lived Pure <span class="hlt">Electron</span> <span class="hlt">Plasma</span> in Ring Trap-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; Yoshida, Zensho; Morikawa, Junji; Watanabe, Sho; Yano, Yoshihisa; Suzuki, Junko</p> <p></p> <p>The Ring Trap-1 (RT-1) experiment succeeded in producing a long-lived (of the order 102 s), stable, non-neutral (pure <span class="hlt">electron</span>) <span class="hlt">plasma</span>. <span class="hlt">Electrons</span> are confined by a magnetospheric dipole field. To eliminate a loss channel of the <span class="hlt">plasmas</span> caused by support structures, a superconducting coil was magnetically levitated. This coil levitation drastically improved the confinement properties of the <span class="hlt">electron</span> <span class="hlt">plasma</span> compared to previous Prototype-Ring Trap (Proto-RT) experiments.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://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="http://ntrs.nasa.gov/search.jsp?R=19770028218&hterms=Ohms+Law&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3DOhms%2BLaw"><span id="translatedtitle">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('http://www.osti.gov/scitech/biblio/22304210','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/22304210"><span id="translatedtitle">Effects of emitted <span class="hlt">electron</span> temperature 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>Sheehan, J. P.; Kaganovich, I. D.; Wang, H.; Raitses, Y.; Sydorenko, D.; Hershkowitz, N.</p> <p>2014-06-15</p> <p>It has long been known that <span class="hlt">electron</span> emission from a surface significantly affects the sheath surrounding that surface. Typical fluid theory of a planar sheath with emitted <span class="hlt">electrons</span> assumes that the <span class="hlt">plasma</span> <span class="hlt">electrons</span> follow the Boltzmann relation and the emitted <span class="hlt">electrons</span> are emitted with zero energy and predicts a potential drop of 1.03T{sub e}/e across the sheath in the floating condition. By considering the modified velocity distribution function caused by <span class="hlt">plasma</span> <span class="hlt">electrons</span> lost to the wall and the half-Maxwellian distribution of the emitted <span class="hlt">electrons</span>, it is shown that ratio of <span class="hlt">plasma</span> <span class="hlt">electron</span> temperature to emitted <span class="hlt">electron</span> temperature significantly affects the sheath potential when the <span class="hlt">plasma</span> <span class="hlt">electron</span> temperature is within an order of magnitude of the emitted <span class="hlt">electron</span> temperature. When the <span class="hlt">plasma</span> <span class="hlt">electron</span> temperature equals the emitted <span class="hlt">electron</span> temperature the emissive sheath potential goes to zero. One dimensional particle-in-cell simulations corroborate the predictions made by this theory. The effects of the addition of a monoenergetic <span class="hlt">electron</span> beam to the Maxwellian <span class="hlt">plasma</span> <span class="hlt">electrons</span> were explored, showing that the emissive sheath potential is close to the beam energy only when the emitted <span class="hlt">electron</span> flux is less than the beam flux.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19930071545&hterms=mixing+particles&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3Dmixing%2Bparticles','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19930071545&hterms=mixing+particles&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3Dmixing%2Bparticles"><span id="translatedtitle">Ion mixing in the <span class="hlt">plasma</span> <span class="hlt">sheet</span> boundary layer by drift instabilities</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Horton, W.; Dong, J. Q.; Su, X. N.; Tajima, T.</p> <p>1993-01-01</p> <p>The linear stability properties of collisionless drift instabilities are analyzed in a Harris equilibrium model of the <span class="hlt">plasma</span> <span class="hlt">sheet</span> boundary layer (PSBL). The strearmng ions with drift-type instabilities driven in the PSBL are considered. The fluid approximation leads to growth but predicts that the mode width approaches the gyroradius of the energetic ions. Thus an integral equation theory for the modes is developed taking into account that in the PSBL the curvature drift is weak compared with the grad-B drift. The exact wave particle resonance is kept in the nonlocal response functions. <span class="hlt">Plasma</span> density, temperature, and magnetic gradient drift motions are taken into account. The drift modes produce an anomalous cross-field momentum transport mixing the PSBL ions on the time scale of tens of seconds. A nonlinear simulation is performed which shows the coalescence of the small scale, fast growing modes into large-scale vortices. The relation between these collective modes and <span class="hlt">plasma</span> <span class="hlt">sheet</span> transport phenomena is discussed including the comparison with the competing <span class="hlt">plasma</span> mixing from single-particle stochasticity.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://w3.pppl.gov/~ikaganov/PPPL2005/Sydorenko.pdf','EPRINT'); return false;" href="http://w3.pppl.gov/~ikaganov/PPPL2005/Sydorenko.pdf"><span id="translatedtitle">Modification of <span class="hlt">Electron</span> Velocity Distribution in Bounded <span class="hlt">Plasmas</span> by</span></a></p> <p><a target="_blank" href="http://www.osti.gov/eprints/">E-print Network</a></p> <p>Kaganovich, Igor</p> <p></p> <p>Modification of <span class="hlt">Electron</span> Velocity Distribution in Bounded <span class="hlt">Plasmas</span> by Secondary <span class="hlt">Electron</span> Emission D and the secondary <span class="hlt">electron</span> emission (SEE) from thruster's channel walls. The fluid theories [1-4] predict fast-like anomalous <span class="hlt">electron</span> mobility [13]; · the model of secondary <span class="hlt">electron</span> emission from the walls [12</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2011AGUFMSM14B..05Y','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011AGUFMSM14B..05Y"><span id="translatedtitle">Investigating the role of the entropy parameter in <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>Yang, J.; Toffoletto, F.; Wolf, R. A.; Sazykin, S.; Hu, B.; Raeder, J.</p> <p>2011-12-01</p> <p>Representing a combination of mass and entropy, the entropy parameter PV5/3 is approximately conserved for <span class="hlt">plasma</span> <span class="hlt">sheet</span> flux tubes and proves very useful for understanding <span class="hlt">plasma</span> <span class="hlt">sheet</span> dynamics. (Here P is <span class="hlt">plasma</span> pressure and V is the volume of a flux tube containing one unit of magnetic flux). Under quasi-static-equilibrium conditions, PV5/3 determines Birkeland currents and interchange instability. It is consequently a key parameter for physical interpretation of results from RCM and RCM-E. The appropriate generalization of PV5/3 for conditions when P is not constant along a field line is the 5/3 power of the flux-tube integral of P3/5. That parameter is conserved in ideal MHD and is useful in physical interpretation of MHD simulations of the magnetosphere. We present recent computer experiments to investigate how the values of PV5/3 in the <span class="hlt">plasma</span> <span class="hlt">sheet</span> can affect the <span class="hlt">plasma</span> transport and field configuration during various geomagnetic active times. A comparative study of RCM-E simulations shows that persistent steady magnetospheric convection during strong polar cap potential drops is possible if the flux tubes in the magnetotail are substantially depleted along a sector with very wide local times; otherwise, the magnetic field will gradually become highly stretched if the inner magnetosphere is fed with relatively high entropy <span class="hlt">plasma</span>, resembling the substorm growth phase. In the end of the growth phase, resistive MHD simulations using OpenGGCM indicate that the violation of frozen-in-flux condition can give rise to the formation of a bubble (lower PV5/3 than its neighbors) earthward of a blob (higher PV5/3 than its neighbors). Both OpenGGCM and RCM-E results show that the earthward motion of the bubble and the tailward motion of the blob lead to a reduction of the normal magnetic field between them, which thins the current <span class="hlt">sheet</span> rapidly. Substorm injection simulations are carried out using RCM-E by placing bubbles on the tailward boundary for both non-storm and storm times. A variety of aspects associated with the bubble injections will be discussed, including the classic substorm injection boundary problem, the reconfiguration of large-scale current systems and the magnetic disturbance in ground magnetograms.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2002SPIE.4720..105X','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2002SPIE.4720..105X"><span id="translatedtitle"><span class="hlt">Electron</span>-beam transmission properties in <span class="hlt">plasma</span> channel</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Xie, Wenkai; Chen, Xi; Meng, Lin; Gao, Xinyan; Liu, Shenggang</p> <p>2002-06-01</p> <p>In this paper the physical mechanism and mathematical description of magnetically self-focusing <span class="hlt">electron</span> beam are studied.The analysis of <span class="hlt">electron</span> beam with weak pulsation in drifting tube filled with <span class="hlt">plasma</span> was given,the beam with strong pulsation under the same condition was also studied accurately.The results show that whether in (alpha) area or in (beta) area both the range and wave length of beam pulsation related to initial condition and <span class="hlt">plasma</span> parameters although their pulsation properties were different,there exited a optimum <span class="hlt">plasma</span> density when the other condition was set.The experimental studies are also reported of beam transmission in <span class="hlt">plasma</span> channel based on Hollow Cathode <span class="hlt">Plasma</span>(HCP) gun in University of <span class="hlt">Electronic</span> Science and Technology of China(UESTC).The study shows that efficient transmission of <span class="hlt">electron</span> beam in <span class="hlt">plasma</span> channel can be reached by choosing the <span class="hlt">plasma</span> filling factor and voltage.</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 id="translatedtitle">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/biblio/22275816','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/22275816"><span id="translatedtitle">Graphene <span class="hlt">electron</span> cannon: High-current edge emission from aligned graphene <span class="hlt">sheets</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Liu, Jianlong; Li, Nannan; Guo, Jing; Fang, Yong; Deng, Jiang; Zeng, Baoqing; Wang, Wenzhong; Li, Jiangnan; Hao, Chenchun</p> <p>2014-01-13</p> <p>High-current field emitters are made by graphene paper consist of aligned graphene <span class="hlt">sheets</span>. Field emission luminance pattern shows that their <span class="hlt">electron</span> beams can be controlled by rolling the graphene paper from <span class="hlt">sheet</span> to cylinder. These specific <span class="hlt">electron</span> beams would be useful to vacuum devices and <span class="hlt">electron</span> beam lithograph. To get high-current emission, the graphene paper is rolled to array and form graphene cannon. Due to aligned emission array, graphene cannon have high emission current. Besides high emission current, the graphene cannon is also tolerable with excellent emission stability. With good field emission properties, these aligned graphene emitters bring application insight.</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/2015PhyE...74..371M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015PhyE...74..371M"><span id="translatedtitle"><span class="hlt">Electronic</span> properties of T graphene-like C-BN <span class="hlt">sheets</span>: A density functional theory study</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Majidi, R.</p> <p>2015-11-01</p> <p>We have used density functional theory to study the <span class="hlt">electronic</span> properties of T graphene-like C, C-BN and BN <span class="hlt">sheets</span>. The planar T graphene with metallic property has been considered. The results show that the presence of BN has a considerable effect on the <span class="hlt">electronic</span> properties of T graphene. The T graphene-like C-BN and BN <span class="hlt">sheets</span> show semiconducting properties. The energy band gap is increased by enhancing the number of BN units. The possibility of opening and controlling band gap opens the door for T graphene in switchable <span class="hlt">electronic</span> devices.</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 id="translatedtitle">Mechanisms for Generating Finite Cross-Tail Jets 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>Pritchett, P. L.</p> <p>2014-12-01</p> <p>In the magnetotail, brief periods of fast <span class="hlt">plasma</span> flow (``bursty bulk flows''--BBFs) provide much of the sunward transport of mass, energy, and magnetic flux. Although usually interpreted as resulting from magnetic reconnection acting in the mid- or more-distant tail, the precise generation mechanism for these flows has never been clearly established. Observationally, a key feature of these flow fronts or jets is that their full cross-tail width in the <span class="hlt">plasma</span> <span class="hlt">sheet</span> is of the order of 1--3 RER_E. The present work examines the relative ability of reconnection and ballooning/interchange (BICI) processes to produce such finite-width fronts. 3D particle-in-cell simulations are used to initiate reconnection in finite-width regions of the <span class="hlt">plasma</span> <span class="hlt">sheet</span> and to generate BICI heads from regions of the <span class="hlt">plasma</span> <span class="hlt">sheet</span> containing a tailward-decreasing entropy profile. For the reconnection jets, the front is observed to expand duskward (in the ion diamagnetic drift direction) to form a structure some 15 did_i wider than the initial localization width. The BICI heads have a comparable extent. Both types of jets feature abrupt increases in the equatorial BzB_z field and both tend to break up in yy due to a secondary interchange instability on a scale of 1--2 did_i. A distinguishing feature between the two types of jets is that the BICI fronts are preceded by an off-equatorial signal involving wave activity near the ion cyclotron frequency that involves intense (30--50 mV/m) electric fields and magnetic perturbations of the order of 10% of the ambient main field. The possibility of producing repeated jets by these mechanisms will be discussed as well.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19900047760&hterms=dropout&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D70%26Ntt%3Ddropout','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19900047760&hterms=dropout&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D70%26Ntt%3Ddropout"><span id="translatedtitle">Extreme energetic particle decreases near geostationary orbit - A manifestation of current diversion within 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>Baker, D. N.; Mcpherron, R. L.</p> <p>1990-01-01</p> <p>A qualitative model of magnetic field reconfiguration as might result from neutral line formation in the central <span class="hlt">plasma</span> <span class="hlt">sheet</span> late in a substorm growth phase is considered. It is suggested that magnetic reconnection probably begins before the substorm expansion phase and that cross-tail current is enhanced across the <span class="hlt">plasma</span> <span class="hlt">sheet</span> both earthward and tailward of a limited region near the neutral line. Such an enhanced cross-tail current earthward of the original X line region may contribute to thinning the <span class="hlt">plasma</span> <span class="hlt">sheet</span> substantially, and this would in turn affect the drift currents in that location, thus enhancing the current even closer toward the earth. In this way a redistribution and progressive diversion of normal cross-tail current throughout much of the inner portion of the <span class="hlt">plasma</span> <span class="hlt">sheet</span> could occur. The resulting intensified current, localized at the inner edge of the <span class="hlt">plasma</span> <span class="hlt">sheet</span>, would lead to a very thin <span class="hlt">plasma</span> confinement region. This would explain the very taillike field and extreme particle dropouts often seen late in substorm growth phases.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015JGRA..120.6167W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015JGRA..120.6167W"><span id="translatedtitle">A statistical analysis of Pi2-band waves in the <span class="hlt">plasma</span> <span class="hlt">sheet</span> and their relation to magnetospheric drivers</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Wang, G. Q.; Ge, Y. S.; Zhang, T. L.; Nakamura, R.; Volwerk, M.; Baumjohann, W.; Du, A. M.; Lu, Q. M.</p> <p>2015-08-01</p> <p>We use the Cluster data from 2001 to 2009 to investigate the occurrence of Pi2-band waves in the <span class="hlt">plasma</span> <span class="hlt">sheet</span>. To study the generation mechanisms of these waves, we examine the association between Pi2-band waves and dynamic processes in the <span class="hlt">plasma</span> <span class="hlt">sheet</span> (fast flows and substorm activity) and the direction of the solar wind velocity. For a total of 80 large-amplitude Pi2-band waves in the <span class="hlt">plasma</span> <span class="hlt">sheet</span>, we find that Cluster records fast flows during 62 events, 11 waves without fast flows occur during substorm time, 3 events occur when the solar wind velocity significantly changes its direction, and 4 events are not associated with any of the above activities. Most of the observed Pi2-band waves are predominantly compressional, while 2 events are transverse. Based on this statistical study, we suggest that fast flows maybe the main driver of Pi2-band waves/oscillations in the <span class="hlt">plasma</span> <span class="hlt">sheet</span>, especially considering that most of these waves are compressional. The relatively small number of other events indicates that other mechanisms also play a role in creating Pi2-band waves/oscillations in the <span class="hlt">plasma</span> <span class="hlt">sheet</span> but are relatively rare. In all wave events of this study, the <span class="hlt">plasma</span> pressure and magnetic pressure vary in antiphase, suggesting that these waves have the slow-mode feature.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://arxiv.org/pdf/hep-th/0508198v2','EPRINT'); return false;" href="http://arxiv.org/pdf/hep-th/0508198v2"><span id="translatedtitle">Spectral analysis of a flat <span class="hlt">plasma</span> <span class="hlt">sheet</span> model</span></a></p> <p><a target="_blank" href="http://www.osti.gov/eprints/">E-print Network</a></p> <p>M. Bordag; I. G. Pirozhenko; V. V. Nesterenko</p> <p>2005-12-25</p> <p>The spectral analysis of the electromagnetic field on the background of a infinitely thin flat <span class="hlt">plasma</span> layer is carried out. This model is loosely imitating a single base plane from graphite and it is of interest for theoretical studies of fullerenes. The model is naturally split into the TE-sector and TM-sector. Both the sectors have positive continuous spectra, but the TM-modes have in addition a bound state, namely, the surface plasmon. This analysis relies on the consideration of the scattering problem in the TE- and TM-sectors. The spectral zeta function and integrated heat kernel are constructed for different branches of the spectrum in an explicit form. As a preliminary, the rigorous procedure of integration over the continuous spectra is formulated by introducing the spectral densityin terms of the scattering phase shifts. The asymptotic expansion of the integrated heat kernel at small values of the evolution parameter is derived. By making use of the technique of integral equations, developed earlier by the same authors, the local heat kernel (Green's function or fundamental solution) is constructed also. As a by-product, a new method is demonstrated for deriving the fundamental solution to the heat conduction equation (or to the Schr\\"odinger equation) on an infinite line with the $\\delta $-like source. In particular, for the heat conduction equation on an infinite line with the $\\delta$-source a nontrivial counterpart is found, namely, a spectral problem with point interaction, that possesses the same integrated heat kernel while the local heat kernels (fundamental solutions) in these spectral problems are different.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/12006024','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/12006024"><span id="translatedtitle">Three-dimensional particle-in-cell simulations of energetic <span class="hlt">electron</span> generation and transport with relativistic laser pulses in overdense <span class="hlt">plasmas</span>.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Sentoku, Y; Mima, K; Sheng, Z M; Kaw, P; Nishihara, K; Nishikawa, K</p> <p>2002-04-01</p> <p>The interaction of relativistic laser light with overdense <span class="hlt">plasmas</span> is studied by three-dimensional particle-in-cell simulations. Generation of layered current <span class="hlt">sheets</span> and quasistatic magnetic fields is observed near the target surface owing to anisotropic laser filamentation and Weibel instabilities. Later these current <span class="hlt">sheets</span> tear into filaments that partially merge with each other to form isolated magnetic channels penetrating into the dense <span class="hlt">plasmas</span>. It is found that fast <span class="hlt">electron</span> energy flow is not only inside the magnetic channels but also it is widely distributed outside the channels. This is possible because of <span class="hlt">electron</span> anomalous diffusion across self-generated magnetic fields. Consequently, the total hot <span class="hlt">electron</span> current exceeds a few hundred kiloamperes and is much larger than the Alfvén current. Hence a considerable amount of energy flows towards the <span class="hlt">plasma</span> core. Significant heating of the bulk <span class="hlt">plasma</span> <span class="hlt">electrons</span> is also observed. PMID:12006024</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 id="translatedtitle">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://www.osti.gov/scitech/servlets/purl/1127069','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/1127069"><span id="translatedtitle">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('http://hdl.handle.net/2060/19740002320','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19740002320"><span id="translatedtitle">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/biblio/22412986','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/22412986"><span id="translatedtitle">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('http://adsabs.harvard.edu/abs/2015JPhCS.591a2051V','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015JPhCS.591a2051V"><span id="translatedtitle">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://ntrs.nasa.gov/search.jsp?R=19990116091&hterms=cold+plasma&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3Dcold%2Bplasma','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19990116091&hterms=cold+plasma&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3Dcold%2Bplasma"><span id="translatedtitle">Whistler Solitons in <span class="hlt">Plasma</span> with Anisotropic Hot <span class="hlt">Electron</span> Admixture</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.; Krivorutsky, E. N.; Gallagher, D. L.</p> <p>1999-01-01</p> <p>The longitudinal and transverse modulation instability of whistler waves in <span class="hlt">plasma</span>, with a small admixture of hot anisotropic <span class="hlt">electrons</span>, is discussed. If the hot particles temperature anisotropy is positive, it is found that, in such <span class="hlt">plasma</span>, longitudinal perturbations can lead to soliton formation for frequencies forbidden in cold <span class="hlt">plasma</span>. The soliton is enriched by hot particles. The frequency region unstable to transverse modulation in cold <span class="hlt">plasma</span> in the presence of hot <span class="hlt">electrons</span> is divided by stable domains. For both cases the role of hot <span class="hlt">electrons</span> is more significant for whistlers with smaller frequencies.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015JPlPh..81e9008L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015JPlPh..81e9008L"><span id="translatedtitle">Solitary waves in asymmetric <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>Lu, Ding; Li, Zi-Liang; Xie, Bai-Song</p> <p>2015-10-01</p> <p>> By solving the coupled equations of the electromagnetic field and electrostatic potential, we investigate solitary waves in an asymmetric <span class="hlt">electron</span>-positron <span class="hlt">plasma</span> and/or <span class="hlt">electron</span>-positron-ion <span class="hlt">plasmas</span> with delicate features. It is found that the solutions of the coupled equations can capture multipeak structures of solitary waves in the case of cold <span class="hlt">plasma</span>, which are left out by using the long-wavelength approximation. By considering the effect of ion motion with respect to non-relativistic and ultra-relativistic temperature <span class="hlt">plasmas</span>, we find that the ions' mobility can lead to larger-amplitude solitary waves; especially, this becomes more obvious for a high-temperature <span class="hlt">plasma</span>. The effects of asymmetric temperature between <span class="hlt">electrons</span> and positrons and the ion fraction on the solitary waves are also studied and presented. It is shown that the amplitudes of solitary waves decrease with positron temperature in asymmetric temperature <span class="hlt">electron</span>-positron <span class="hlt">plasmas</span> and decrease also with ion concentration.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www-pw.physics.uiowa.edu/~dag/publications/2010_APlasmaFlowVelocityBoundaryAtMarsFromTheDisappearanceOfElectronPlasmaOscillations_ICARUS.pdf','EPRINT'); return false;" href="http://www-pw.physics.uiowa.edu/~dag/publications/2010_APlasmaFlowVelocityBoundaryAtMarsFromTheDisappearanceOfElectronPlasmaOscillations_ICARUS.pdf"><span id="translatedtitle">A <span class="hlt">plasma</span> flow velocity boundary at Mars from the disappearance of <span class="hlt">electron</span> <span class="hlt">plasma</span> oscillations</span></a></p> <p><a target="_blank" href="http://www.osti.gov/eprints/">E-print Network</a></p> <p>Gurnett, Donald A.</p> <p></p> <p>echo due to vertical reflection from the horizontally stratified ionosphere is measured (Gurnett et al sounding mode, the sounder transmitter excites electrostatic <span class="hlt">electron</span> <span class="hlt">plasma</span> oscillations at the local</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/22163071','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/22163071"><span id="translatedtitle">Terahertz rectification by periodic two-dimensional <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>Popov, V. V.; Saratov State University, Saratov 410012 </p> <p>2013-06-24</p> <p>The physics of terahertz rectification by periodic two-dimensional <span class="hlt">electron</span> <span class="hlt">plasma</span> is discussed. Two different effects yielding terahertz rectification are studied: the plasmonic drag and plasmonic ratchet. Ultrahigh responsivity of terahertz rectification by periodic two-dimensional <span class="hlt">electron</span> <span class="hlt">plasma</span> in semiconductor heterostructures and graphene is predicted.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/21409508','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/21409508"><span id="translatedtitle">Thermal field theory in a layer: Applications of thermal field theory methods to the propagation of photons in a two-dimensional <span class="hlt">electron</span> <span class="hlt">sheet</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Nieves, Jose F.</p> <p>2010-04-01</p> <p>We apply the thermal field theory methods to study the propagation of photons in a <span class="hlt">plasma</span> layer, that is a <span class="hlt">plasma</span> in which the <span class="hlt">electrons</span> are confined to a two-dimensional plane <span class="hlt">sheet</span>. We calculate the photon self-energy and determine the appropriate expression for the photon propagator in such a medium, from which the properties of the propagating modes are obtained. The formulas for the photon dispersion relations and polarization vectors are derived explicitly in some detail for some simple cases of the thermal distributions of the charged particle gas, and appropriate formulas that are applicable in more general situations are also given.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/25853407','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/25853407"><span id="translatedtitle">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=pubmed">PubMed</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://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4431294','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4431294"><span id="translatedtitle">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://www.osti.gov/scitech/biblio/22218323','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/22218323"><span id="translatedtitle"><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/2013PhPl...20l2113S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013PhPl...20l2113S"><span id="translatedtitle"><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://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</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>2013-12-01</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> </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://www.osti.gov/scitech/biblio/22218489','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/22218489"><span id="translatedtitle"><span class="hlt">Electron</span> energy distribution function control in gas discharge <span class="hlt">plasmas</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Godyak, V. A.</p> <p>2013-10-15</p> <p>The formation of the <span class="hlt">electron</span> energy distribution function (EEDF) and <span class="hlt">electron</span> temperature in low temperature gas discharge <span class="hlt">plasmas</span> is analyzed in frames of local and non-local <span class="hlt">electron</span> kinetics. It is shown, that contrary to the local case, typical for <span class="hlt">plasma</span> in uniform electric field, there is the possibility for EEDF modification, at the condition of non-local <span class="hlt">electron</span> kinetics in strongly non-uniform electric fields. Such conditions “naturally” occur in some self-organized steady state dc and rf discharge <span class="hlt">plasmas</span>, and they suggest the variety of artificial methods for EEDF modification. EEDF modification and <span class="hlt">electron</span> temperature control in non-equilibrium conditions occurring naturally and those stimulated by different kinds of <span class="hlt">plasma</span> disturbances are illustrated with numerous experiments. The necessary conditions for EEDF modification in gas discharge <span class="hlt">plasmas</span> are formulated.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://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="http://ntrs.nasa.gov/search.jsp?R=19910030164&hterms=IRM&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3DIRM"><span id="translatedtitle">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/2011PhDT........42N','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011PhDT........42N"><span id="translatedtitle">Measurements of <span class="hlt">plasma</span> bremsstrahlung and <span class="hlt">plasma</span> energy density produced by <span class="hlt">electron</span> cyclotron resonance ion source <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>Noland, Jonathan David</p> <p>2011-12-01</p> <p>The goal of this dissertation was to gain an understanding on the relative importance of microwave power, neutral pressure, and magnetic field configuration on the behavior of the hot <span class="hlt">electrons</span> within an <span class="hlt">Electron</span> Cyclotron Resonance Ion Source (ECRIS) <span class="hlt">plasma</span>. This was carried out through measurement of <span class="hlt">plasma</span> bremsstrahlung with both NaI(Tl) (hv > 30 keV) and CdTe (2 keV < hv < 70 keV) x-ray detectors, and through measurement of the <span class="hlt">plasma</span> energy density with a diamagnetic loop placed around the <span class="hlt">plasma</span> chamber. We also examined the anisotropy in x-ray power by simultaneously measuring the x-ray spectra in two orthogonal directions: radially and axially, using NaI(Tl) detectors. We have seen that for a 6.4 GHz ECRIS, both the x-ray power produced by confined <span class="hlt">electrons</span> and the <span class="hlt">plasma</span> energy density behave logarithmically with microwave power. The x-ray flux created by <span class="hlt">electrons</span> lost from the <span class="hlt">plasma</span>, however, does not saturate. Thus, the small increase in <span class="hlt">plasma</span> density that occurred at high microwave powers (> 150 W on a 6.4 GHz ECRIS) was accompanied by a large increase in total x-ray power. We suggest that the saturation of x-ray power and <span class="hlt">plasma</span> energy density was due to rf-induced pitch-angle scattering of the <span class="hlt">electrons</span>. X-ray power and <span class="hlt">plasma</span> energy density were also shown to saturate with neutral pressure, and to increase nearly linearly as the gradient of the magnetic field in the resonance zone was decreased. All of these findings were in agreement with the theoretical models describing ECRIS <span class="hlt">plasmas</span>. We have discussed the use of a diamagnetic loop as a means of exploring various <span class="hlt">plasma</span> time scales on a relative basis. Specifically, we focused much of our attention on studying how changing ion source parameters, such as microwave power and neutral pressure, would effect the rise and decay of the integrated diamagnetic signal, which can be related to <span class="hlt">plasma</span> energy density. We showed that increasing microwave power lowers the e-fold times at both the leading edge and the trailing edge of the microwave pulse. Microwave power, however, had almost no impact on the ignition times of the <span class="hlt">plasma</span>. The <span class="hlt">plasma</span> energy density e-fold times were insensitive to both neutral pressure and magnetic field setting. Neutral pressure, however, had a dramatic effect on the time of first appearance of the diamagnetic signal ("<span class="hlt">plasma</span> ignition time"). In addition to neutral pressure, ignition times were also a function the relative abundance of <span class="hlt">electrons</span> in the <span class="hlt">plasma</span> chamber at the beginning of a microwave pulse. In all instances, the rise time of the integrated diamagnetic signal was seen to be faster than the decay time. By comparing the unintegrated diamagnetic signal to the ratio of reflected to forward microwave power we theorized that the initial, exponential rise in the diamagnetic signal at the leading edge of a microwave pulse was due to rapid changes in both the average <span class="hlt">electron</span> energy and density. During the slowly decaying portion of the diamagnetic loop signal, only the hot tail of the <span class="hlt">electron</span> population was increasing. This theory was supported by time resolved, low energy x-ray measurements that showed that the period of rapid change of the ratio of reflected to forward microwave power coincided with a rapid change in average photon energy. We have also showed that x-rays production in an ECRIS <span class="hlt">plasma</span> was highly anisotropic, with radial x-ray counts being much greater than axial x-ray counts. This was shown to be true for both the "ECR" (operating at 6.4 GHz) and the higher performance "AECR-U" (operating at 14 GHz). Based on this, we can make the qualitative statement that the <span class="hlt">electron</span> energy was also highly anisotropic, with a much larger perpendicular energy than parallel energy. The degree of anisotropy was shown to increase with the operating frequency of the ion source. This increase was most likely attributable to the higher power density and greater confinement associated with higher performance machines, and implies that superconducting ECRIS operating at very high freq</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015EP%26S...67..168C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015EP%26S...67..168C"><span id="translatedtitle">Relationship between wave-like auroral arcs and Pi2 disturbances in <span class="hlt">plasma</span> <span class="hlt">sheet</span> prior to substorm onset</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Chang, Tzu-Fang; Cheng, Chio-Zong</p> <p>2015-12-01</p> <p>Wave-like substorm arc features in the aurora and Pi2 magnetic disturbances observed in the near-Earth <span class="hlt">plasma</span> <span class="hlt">sheet</span> are frequently, and sometimes simultaneously, observed around the substorm onset time. We perform statistical analyses of the THEMIS ASI auroral observations that show wave-like bright spot structure along the arc prior to substorm onset. The azimuthal mode number values of the wave-like substorm arcs are found to be in the range of ~100-240 and decrease with increasing geomagnetic latitude of the substorm auroral arc location. We suggest that the azimuthal mode number is likely related to the ion gyroradius and azimuthal wave number. We also perform correlation study of the pre-onset wave-like substorm arc features and Pi2 magnetic disturbances for substorm dipolarization events observed by THEMIS satellites during 2008-2009. The wave-like arc brightness structures on the substorm auroral arcs tend to move azimuthally westward, but with a few exceptions of eastward movement, during tens of seconds prior to the substorm onset. The movement of the wave-like arc brightness structure is linearly correlated with the phase velocity of the Pi2 ? B y disturbances in the near-Earth <span class="hlt">plasma</span> <span class="hlt">sheet</span> region. The result suggests that the Pi2 transverse ? B y disturbances are related to the intensifying wave-like substorm onset arcs. One plausible explanation of the observations is the kinetic ballooning instability, which has high azimuthal mode number due to the ion gyroradius effect and finite parallel electric field that accelerates <span class="hlt">electrons</span> into the ionosphere to produce the wave-like arc structure.</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 id="translatedtitle">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://arxiv.org/pdf/1508.05971.pdf','EPRINT'); return false;" href="http://arxiv.org/pdf/1508.05971.pdf"><span id="translatedtitle"><span class="hlt">Electron</span> Sheaths: The Outsized Influence of Positive Boundaries on <span class="hlt">Plasmas</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/eprints/">E-print Network</a></p> <p>Yee, Benjamin T; Baalrud, Scott D; Barnat, Edward V; Hopkins, Matthew M</p> <p>2015-01-01</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 in the <span class="hlt">electron</span> saturation region of a Langmuir probe trace. 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, 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 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://adsabs.harvard.edu/abs/2012JPhCS.365a2051P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012JPhCS.365a2051P"><span id="translatedtitle">Comparative simulation studies of <span class="hlt">plasma</span> cathode <span class="hlt">electron</span> (PCE) gun</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Prajapati, Jitendra; Pal, U. N.; Kumar, Niraj; Verma, D. K.; Prakash, Ram; Srivastava, V.</p> <p>2012-05-01</p> <p>Pseudospark discharge based <span class="hlt">plasma</span> cathode has capability to provide high current density <span class="hlt">electron</span> beam during discharge process. In this paper an effort has been made to simulate the breakdown processes in the pseudospark discharge based <span class="hlt">plasma</span> cathode <span class="hlt">electron</span> gun. The two-dimensional <span class="hlt">plasma</span> simulation codes VORPAL and OOPIC-Pro have been used and results are compared. The peak discharge current in the <span class="hlt">plasma</span> cathode <span class="hlt">electron</span> gun is found to be dependent on aperture size, hollow cathode dimensions, anode voltage and seed <span class="hlt">electrons</span> energy. The effect of these design parameters on the peak anode current has been analysed by both the codes and results matches well within 10% variation. For the seed <span class="hlt">electron</span> generation an <span class="hlt">electron</span> beam trigger source is used to control the discharge process in the hollow cathode cavity. The time span of trigger source has been varied from 1-100 ns to analyze the effect on the peak anode current.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://w3.pppl.gov/~ikaganov/PPPL2005/Beilis.pdf','EPRINT'); return false;" href="http://w3.pppl.gov/~ikaganov/PPPL2005/Beilis.pdf"><span id="translatedtitle">2005 Workshop on NCETIP 1 Kinetic of <span class="hlt">plasma</span> particles and <span class="hlt">electron</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/eprints/">E-print Network</a></p> <p>Kaganovich, Igor</p> <p></p> <p>action on metals. · Ablative <span class="hlt">plasma</span> accelerators · MHD power conversion. · Vacuum arc Cathode spot · <span class="hlt">Plasma</span> in vacuum arc cathode spot. <span class="hlt">Electron</span> transport · Cathode evaporation DIFFERENT CATHODE MATERIALSTeflon evaporation TEFLON Teflon evaporation CATHODE ANODE <span class="hlt">Plasma</span> expansion Pulsed <span class="hlt">Plasma</span>Pulsed <span class="hlt">Plasma</span> Thrusters</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015PhPl...22j2116A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015PhPl...22j2116A"><span id="translatedtitle">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://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Allanson, O.; Neukirch, T.; Wilson, F.; Troscheit, S.</p> <p>2015-10-01</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://ntrs.nasa.gov/search.jsp?R=19810025909&hterms=Planck+Max&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D80%26Ntt%3D%2528Planck%2BMax%2529','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19810025909&hterms=Planck+Max&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D80%26Ntt%3D%2528Planck%2BMax%2529"><span id="translatedtitle">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('http://arxiv.org/pdf/1510.07667v1','EPRINT'); return false;" href="http://arxiv.org/pdf/1510.07667v1"><span id="translatedtitle">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/eprints/">E-print Network</a></p> <p>O. Allanson; T. Neukirch; F. Wilson; S. Troscheit</p> <p>2015-10-26</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://arxiv.org/pdf/1504.05677.pdf','EPRINT'); return false;" href="http://arxiv.org/pdf/1504.05677.pdf"><span id="translatedtitle">A Theoretical Model of Pinching Current <span class="hlt">Sheet</span> in Low-beta <span class="hlt">Plasmas</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/eprints/">E-print Network</a></p> <p>Takeshige, Satoshi; Shibata, Kazunari</p> <p>2015-01-01</p> <p>Magnetic reconnection is an important physical process in various explosive phenomena in the universe. In the previous studies, it was found that fast re- connection takes place when the thickness of a current <span class="hlt">sheet</span> becomes on the order of a microscopic length such as the ion larmor radius or the ion inertial length. In this study, we investigated the pinching process of a current <span class="hlt">sheet</span> by the Lorentz force in a low-{\\beta} <span class="hlt">plasma</span> using one-dimensional magnetohydrodynam- ics (MHD) simulations. It is known that there is an exact self-similar solution for this problem that neglects gas pressure. We compared the non-linear MHD dynamics with the analytic self-similar solution. From the MHD simulations, we found that with the gas pressure included the implosion process deviates from the analytic self-similar solution as t {\\rightarrow} t 0, where t 0 is the explosion time when the thickness of a current <span class="hlt">sheet</span> of the analytic solution becomes 0. We also found a pair of MHD fast-mode shocks are generated and propaga...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013EGUGA..15.9758F','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013EGUGA..15.9758F"><span id="translatedtitle">In situ observations of the <span class="hlt">plasma</span> <span class="hlt">sheet</span> at high latitudes in conjunction with 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, Robert; Milan, Steve; Maggiolo, Romain</p> <p>2013-04-01</p> <p>Transpolar arcs are auroral features which extend from the night side of the Earth's main auroral oval into the polar cap. Recent statistical studies have shown that they are formed by the closure of magnetic flux in the magnetotail during intervals when the IMF is northward and there is a cross-tail (BY ) component of the lobe magnetic field (due to the earlier IMF conditions). Under these circumstances, newly closed flux in the midnight sector has northern and southern hemisphere footprints that straddle the midnight meridian; this prevents the closed flux from returning to the day side in a simple manner. As tail reconnection continues, the footprints of closed field lines protrude into the polar cap, and the auroral emissions on these footprints form the transpolar arc. This mechanism predicts that closed flux should build up on the night side, embedded within the lobe. 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. 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/2012AdSpR..50..101E','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012AdSpR..50..101E"><span id="translatedtitle">Nonlinear electromagnetic perturbations in a degenerate <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.; Mamun, A. A.; El-Shorbagy, Kh. H.</p> <p>2012-07-01</p> <p>Nonlinear propagation of fast and slow magnetosonic perturbation modes in an ultra-cold, degenerate (extremely dense) <span class="hlt">electron</span>-positron (EP) <span class="hlt">plasma</span> (containing non-relativistic, ultra-cold, degenerate <span class="hlt">electron</span> and positron fluids) has been investigated by the reductive perturbation method. It is shown that due to the property of being equal mass of the <span class="hlt">plasma</span> species (me=mp, where me and mp are <span class="hlt">electron</span> and positron mass, respectively), the degenerate EP <span class="hlt">plasma</span> system supports the K-dV solitons which are associated with either fast or slow magnetosonic perturbation modes. It is also found that the basic features of the electromagnetic solitary structures, which are found to exist in such a degenerate EP <span class="hlt">plasma</span>, are significantly modified by the effects of degenerate <span class="hlt">electron</span> and positron pressures. The applications of the results in an EP <span class="hlt">plasma</span> medium, which occurs in compact astrophysical objects, particularly in white dwarfs, have been briefly discussed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/535596','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/535596"><span id="translatedtitle">On-line monitoring of laser welding of <span class="hlt">sheet</span> metal by special evaluation of <span class="hlt">plasma</span> radiation</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Kluft, W.; Boerger, P.; Schwartz, R.</p> <p>1996-12-31</p> <p>During laser welding of closed sections, visual control of the seam root is usually difficult or often impossible to realize. A newly developed method for the evaluation of the <span class="hlt">plasma</span> radiation from the welded capillary allows to monitor the seam root formation on-line from the working side. The beam emission is not constant, but subject to kHz-fluctuations. A real-time analysis of the occurring frequencies gives a clear information of whether or not the seam capillary on the <span class="hlt">sheet</span> metal underside is open. In case of root penetration higher frequencies occur more intensely in the frequency spectrum. The analysis of the frequency spectrum allows to decide whether the seam capillary on the underside is opened and full penetration is achieved. A full penetration weld results in a constant and smooth signal. If the seam root is partially not welded through, the signal amplitude will raise and the signal will increase up to the double of the SET-value. The analysis of penetration welding was tested for <span class="hlt">sheet</span> metal with thicknesses ranging from 0.3 to 4 mm for the CO{sub 2}-laser welding of iron and aluminum materials. Furthermore during the oral presentation a possibility will be shown, how an UV <span class="hlt">plasma</span> detector can be placed completely protected in the beam path near the focusing optic with the help of a scraper mirror.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=20110011013&hterms=evidence+law&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3Devidence%2Blaw','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=20110011013&hterms=evidence+law&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3Devidence%2Blaw"><span id="translatedtitle">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('http://adsabs.harvard.edu/abs/2013RScI...84a3307K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013RScI...84a3307K"><span id="translatedtitle">Multifunctional bulk <span class="hlt">plasma</span> source based on discharge with <span class="hlt">electron</span> injection</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Klimov, A. S.; Medovnik, A. V.; Tyunkov, A. V.; Savkin, K. P.; Shandrikov, M. V.; Vizir, A. V.</p> <p>2013-01-01</p> <p>A bulk <span class="hlt">plasma</span> source, based on a high-current dc glow discharge with <span class="hlt">electron</span> injection, is described. <span class="hlt">Electron</span> injection and some special design features of the <span class="hlt">plasma</span> arc emitter provide a <span class="hlt">plasma</span> source with very long periods between maintenance down-times and a long overall lifetime. The source uses a sectioned sputter-electrode array with six individual sputter targets, each of which can be independently biased. This discharge assembly configuration provides multifunctional operation, including <span class="hlt">plasma</span> generation from different gases (argon, nitrogen, oxygen, acetylene) and deposition of composite metal nitride and oxide coatings.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19730054145&hterms=electron+backscattering&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3Delectron%2Bbackscattering','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19730054145&hterms=electron+backscattering&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3Delectron%2Bbackscattering"><span id="translatedtitle">Effect of an isotropic nonequilibrium <span class="hlt">plasma</span> on <span class="hlt">electron</span> temperature measurements.</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Benson, R. F.; Hoegy, W. R.</p> <p>1973-01-01</p> <p>The <span class="hlt">electron</span> temperatures that would be determined (using the conventional single-temperature analysis) by the electrostatic probe, the diffuse resonance, and the radar backscatter techniques in an isotropic two-temperature <span class="hlt">plasma</span> are presented. <span class="hlt">Plasma</span> models corresponding to the addition of a minor component of energetic <span class="hlt">electrons</span> and models corresponding to a process that cools a fraction of the ionospheric <span class="hlt">electrons</span> are considered. The diffuse resonance temperature is found to lie between the probe and radar backscatter temperatures. The isotropic models corresponding to the addition of energetic <span class="hlt">electrons</span> cannot support the reported discrepancies between radio wave and probe <span class="hlt">electron</span> temperature measurements. Temperature differences similar to the observed differences can be produced by models with a fraction of the <span class="hlt">electrons</span> at a temperature cooler than that of the main component of <span class="hlt">electrons</span>. These models, however, are difficult to explain in terms of present understanding of the ionospheric <span class="hlt">plasma</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19990099700&hterms=McCarthy&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3DMcCarthy%252C%2BR','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19990099700&hterms=McCarthy&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3DMcCarthy%252C%2BR"><span id="translatedtitle">The Relationship of Ion Beams and Fast Flows 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>Parks, G. K.; Reme, H.; Lin, R. P.; Sanderson, T.; Germany, G. A.; Spann, James F., Jr.; Brittnacher, M. J.; McCarthy, M.; Chen, L. J.; Larsen, D.; Phan, T. D.</p> <p>1998-01-01</p> <p>We report new findings on the behavior of <span class="hlt">plasmas</span> in the vicinity of the <span class="hlt">plasma</span> <span class="hlt">sheet</span> boundary layer (PSBL). A large geometrical factor detector on WIND (3D <span class="hlt">plasma</span> experiment) has discovered a unidirectional ion beam streaming in the tailward direction missed by previous observations. This tailward beam is as intense as the earthward streaming beam and it is found just inside the outer edge of the PSBL where earthward streaming beams are observed. The region where this tailward beam is observed includes an isotropic <span class="hlt">plasma</span> component which is absent in the outer edge where earthward streaming beams are found. When these different distributions are convolved to calculate the velocity moments, fast flows (greater than 400 km/s) result in the earthward direction and much slower flows (less than 200 km/s) in the tailward direction. These new findings are substantially different from previous observations. Thus, the interpretation of fast flows and earthward and counterstreaming ion beams in terms of a neutral line model must be reexamined.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pantherfile.uwm.edu/jhchen/www/Publications/pos_corona_plasma_2002.pdf','EPRINT'); return false;" href="https://pantherfile.uwm.edu/jhchen/www/Publications/pos_corona_plasma_2002.pdf"><span id="translatedtitle"><span class="hlt">Plasma</span> Chemistry and <span class="hlt">Plasma</span> Processing, Vol. 22, No. 2, June 2002 ( 2002) <span class="hlt">Electron</span> Density and Energy Distributions in</span></a></p> <p><a target="_blank" href="http://www.osti.gov/eprints/">E-print Network</a></p> <p>Chen, Junhong</p> <p></p> <p><span class="hlt">Plasma</span> Chemistry and <span class="hlt">Plasma</span> Processing, Vol. 22, No. 2, June 2002 ( 2002) <span class="hlt">Electron</span> Density in the corona <span class="hlt">plasma</span> is required to quantify the chemical processes. In this paper, the <span class="hlt">electron</span> density- ness of the <span class="hlt">plasma</span> and the <span class="hlt">electron</span> energy distribution are not affected. Smaller electrodes produce</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://www.ncbi.nlm.nih.gov/pubmed/23368060','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/23368060"><span id="translatedtitle"><span class="hlt">Electron</span> acoustic shock waves in a collisional <span class="hlt">plasma</span>.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Dutta, Manjistha; Ghosh, Samiran; Chakrabarti, Nikhil</p> <p>2012-12-01</p> <p>A nonlinear analysis for the finite amplitude <span class="hlt">electron</span> acoustic wave (EAW) is considered in a collisional <span class="hlt">plasma</span>. The fluid model is used to describe the two-temperature <span class="hlt">electron</span> species in a fixed ion background. In general, in <span class="hlt">electron</span>-ion <span class="hlt">plasma</span>, the presence of wave nonlinearity, dispersion, and dissipation (arising from fluid viscosity) give rise to the Korteweg-de Vries Burgers (KdVB) equation which exhibits shock wave. In this work, it is shown that the dissipation due to the collision between <span class="hlt">electron</span> and ion in the presence of collective phenomena (<span class="hlt">plasma</span> current) can also introduce an anomalous dissipation that causes the Burgers term and thus leads to the generation of <span class="hlt">electron</span> acoustic shock wave. Both analytical and numerical analysis show the formation of transient shock wave. Relevance of the results are discussed in the context of space <span class="hlt">plasma</span>. PMID:23368060</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/21268989','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/21268989"><span id="translatedtitle">Analysis of wakefield <span class="hlt">electron</span> orbits in <span class="hlt">plasma</span> wiggler</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Ta Phuoc, Kim; Corde, Sebastien; Fitour, Romuald; Shah, Rahul; Albert, Felicie; Rousseau, Jean-Philippe; Burgy, Frederic; Rousse, Antoine; Seredov, Vasily; Pukhov, Alexander</p> <p>2008-07-15</p> <p>In relativistic laser <span class="hlt">plasma</span> interaction, <span class="hlt">electrons</span> can be simultaneously accelerated and wiggled in an ion cavity created in the wake of an intense short pulse laser propagating in an underdense <span class="hlt">plasma</span>. As a consequence of their motion, the accelerated <span class="hlt">electrons</span> emit an intense x-ray beam called laser produced betatron radiation. Being an emission from charged particles, the features of the betatron source are directly linked to the <span class="hlt">electrons</span> trajectories. In particular, the radiation is emitted in the direction of the <span class="hlt">electrons</span> velocity. In this article we show how an image of <span class="hlt">electrons</span> orbits in the wakefield cavity can be deduced from the structure of x-ray spatial profiles.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/22252089','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/22252089"><span id="translatedtitle">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('http://ntrs.nasa.gov/search.jsp?R=19720054061&hterms=bhabha&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3Dbhabha','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19720054061&hterms=bhabha&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3Dbhabha"><span id="translatedtitle">Energy loss of fast <span class="hlt">electrons</span> and positrons in a <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>Gould, R. J.</p> <p>1972-01-01</p> <p>Calculation of the stopping power of a <span class="hlt">plasma</span> for fast <span class="hlt">electrons</span> and positrons. First the classical limit is considered where beta = v/c is much less than alpha is the fine structure constant. Then the nonrelativistic Born-approximation formulas are derived; this domain corresponds to alpha much less than beta much less than 1. Finally, the general case of relativistic <span class="hlt">electrons</span> and positrons is treated; in the relativistic case the scattering cross sections of Moller (<span class="hlt">electron-electron</span>) and Bhabha (positron-<span class="hlt">electron</span>) are used in the calculation. In all three energy domains the problem is broken up into cases of small and large momentum transfers. For large q, scattering off individual <span class="hlt">plasma</span> <span class="hlt">electrons</span> is considered, while in the limit of very small q for the quantum-mechanical domain, excitation of quantized <span class="hlt">plasma</span> oscillations contributes to dE/dx; in the classical limit for small q the polarizability of the <span class="hlt">plasma</span> provides the effective cutoff. The formulas for the stopping power differ slightly from those for a heavy ion going through a <span class="hlt">plasma</span> because there are exchange effects and the fast <span class="hlt">electrons</span> and positrons can lose a large fraction of their energy in one scattering off a <span class="hlt">plasma</span> <span class="hlt">electron</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/962209','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/962209"><span id="translatedtitle">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 and benchmark for a 2-D Harris current <span class="hlt">sheet</span> against tearing mode and other instabilities in linear theories/models. More importantly, we have, for the first time, carried out simulation of linear instabilities in a 2-D Harris current <span class="hlt">sheet</span> with a broad range of guide field BG and the realistic mi/me, and obtained important new results of current <span class="hlt">sheet</span> instabilities in the presence of a finite BG. Indeed the code has accurately reproduced waves of interest here, such as kinetic Alfven waves, compressional Alfven/whistler wave, and lower-hybrid/modified two-stream waves. Moreover, this simulation scheme is capable of investigating collisionless kinetic physics relevant to magnetic reconnection in the fusion <span class="hlt">plasmas</span>, in a global scale system for a long-time evolution and, thereby, produce significant new physics compared with both full-particle and hybrid codes. The results, with mi/me=1836 and moderate to large BG as in the real laboratory devices, have not been obtained in previous theory and simulations. The new simulation model will contribute significantly not only to the understanding of fundamental fusion (and space) <span class="hlt">plasma</span> physics but also to DOE's SciDAC initiative by further pushing the frontiers of simulating realistic fusion <span class="hlt">plasmas</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://w3.pppl.gov/~fisch/web/1997a.pdf','EPRINT'); return false;" href="http://w3.pppl.gov/~fisch/web/1997a.pdf"><span id="translatedtitle"><span class="hlt">Electron</span>-ion collisions in intensely illuminated <span class="hlt">plasmas</span> G. Shvetsa)</span></a></p> <p><a target="_blank" href="http://www.osti.gov/eprints/">E-print Network</a></p> <p></p> <p></p> <p><span class="hlt">Electron</span>-ion collisions in intensely illuminated <span class="hlt">plasmas</span> G. Shvetsa) and N. J. Fisch Princeton, the collisions of <span class="hlt">electrons</span> with ions can be made more frequent or less frequent, depending on the polarization 00802-1 I. INTRODUCTION The presence of an electromagnetic wave alters <span class="hlt">electron</span>- ion collisions, thereby</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2000RScI...71..859O','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2000RScI...71..859O"><span id="translatedtitle">Influence of <span class="hlt">electron</span> injection on <span class="hlt">electron</span> cyclotron resonance <span class="hlt">plasma</span> properties and reflected mode <span class="hlt">electrons</span> (abstract)</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ovsyannikov, V. P.; Ullmann, F.; Zschornack, G.</p> <p>2000-02-01</p> <p>The injection of an additional strong focused <span class="hlt">electron</span> beam from a special designed <span class="hlt">electron</span> gun into a magnetic <span class="hlt">electron</span> cyclotron resonance (ECR) confinement field is studied. The <span class="hlt">electron</span> gun uses a cathode with a long lifetime and resistiveness providing high emission current densities with <span class="hlt">electron</span> currents up to 50 mA and voltages up to 4 keV. A sequence of aluminum foils is used to investigate the trajectories of the <span class="hlt">electrons</span> in the magnetic field without <span class="hlt">plasma</span>. The high density <span class="hlt">electron</span> beam passes through the foils, welds them, and prints its image into the foils. Details of this technique are described in Ref. 1. Using this technique we see that before the <span class="hlt">electrons</span> enter the sextupole region the beam moves along the magnetic straight lines preserving its structure. Only a central beam passes through the sextupole region, thereby changing its form due to the interaction with radial components of the magnetic field. A new operation method at our 14.5 GHz ECR ion source is based on so-called reflection mode <span class="hlt">electrons</span> (RMEs) analogous to a known <span class="hlt">electron</span> beam ion source operation regime.2 The basic idea is that <span class="hlt">electrons</span>, which traveling from the cathode in a strong axial field, meet an anticathode potential, are reflected from it, move back to the cathode, and will be reflected again and so on. It can be supposed that the <span class="hlt">electrons</span> will make reflections up to the moment when the anode aperture of the gun is fulfilled and the <span class="hlt">electrons</span> will be collected on the anode electrode. Investigations are performed extracting nitrogen ions using the RME beam. As a result we got a clear increase in the beam current of the extracted ions (e.g., at 10 mA <span class="hlt">electron</span> injection an increase of the current of N5+ ions up to 400%) and a shift of the measured ion charge state distribution to higher mean ionization stages. Measured x-ray spectra from a neon loaded <span class="hlt">plasma</span> show for the case of RME operation increasing energy shifts to the high energy side of the spectra, i.e., the mean ionization degree of the ions in the <span class="hlt">plasma</span> increases. They also increase the intensity of the neon K x rays (more than 100% increase for RME injection of Ee=4 keV and Ie=10 mA) indicating that for the same operation parameters the mean density of energetic <span class="hlt">electrons</span> rises at RME injection, i.e., there are more <span class="hlt">electrons</span> with energies high enough to ionize K-shell <span class="hlt">electrons</span> in neon.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015PhPl...22k2111A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015PhPl...22k2111A"><span id="translatedtitle">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://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Akbari-Moghanjoughi, M.; Ghorbanalilu, M.</p> <p>2015-11-01</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> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/22063716','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/22063716"><span id="translatedtitle"><span class="hlt">Electron</span> current extraction from a permanent magnet waveguide <span class="hlt">plasma</span> cathode</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Weatherford, B. R.; Foster, J. E.; Kamhawi, H.</p> <p>2011-09-15</p> <p>An <span class="hlt">electron</span> cyclotron resonance <span class="hlt">plasma</span> produced in a cylindrical waveguide with external permanent magnets was investigated as a possible <span class="hlt">plasma</span> cathode <span class="hlt">electron</span> source. The configuration is desirable in that it eliminates the need for a physical antenna inserted into the <span class="hlt">plasma</span>, the erosion of which limits operating lifetime. <span class="hlt">Plasma</span> bulk density was found to be overdense in the source. Extraction currents over 4 A were achieved with the device. Measurements of extracted <span class="hlt">electron</span> currents were similar to calculated currents, which were estimated using Langmuir probe measurements at the <span class="hlt">plasma</span> cathode orifice and along the length of the external plume. The influence of facility effects and trace ionization in the anode-cathode gap are also discussed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/21974587','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/21974587"><span id="translatedtitle"><span class="hlt">Electron</span> current extraction from a permanent magnet waveguide <span class="hlt">plasma</span> cathode.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Weatherford, B R; Foster, J E; Kamhawi, H</p> <p>2011-09-01</p> <p>An <span class="hlt">electron</span> cyclotron resonance <span class="hlt">plasma</span> produced in a cylindrical waveguide with external permanent magnets was investigated as a possible <span class="hlt">plasma</span> cathode <span class="hlt">electron</span> source. The configuration is desirable in that it eliminates the need for a physical antenna inserted into the <span class="hlt">plasma</span>, the erosion of which limits operating lifetime. <span class="hlt">Plasma</span> bulk density was found to be overdense in the source. Extraction currents over 4 A were achieved with the device. Measurements of extracted <span class="hlt">electron</span> currents were similar to calculated currents, which were estimated using Langmuir probe measurements at the <span class="hlt">plasma</span> cathode orifice and along the length of the external plume. The influence of facility effects and trace ionization in the anode-cathode gap are also discussed. PMID:21974587</p> </li> <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 id="translatedtitle">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://www.ncbi.nlm.nih.gov/pubmed/23920166','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/23920166"><span id="translatedtitle">Quantification of ridging in ferritic stainless steel <span class="hlt">sheets</span> by <span class="hlt">electron</span> backscattered diffraction R-value maps.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Lee, Kye-Man; Park, Jieon; Kim, Sangseok; Park, Sooho; Huh, Moo-Young</p> <p>2013-08-01</p> <p>In ferritic stainless steel (FSS), undesirable surface defects of ridging appear during deep drawing. The formation of these defects is attributed to the inhomogeneous distribution of orientations of individual grains. In the present work, a new <span class="hlt">electron</span> backscattered diffraction R(?)-value map was introduced, and the dependence of the tensile directions on the formation of ridging in an FSS <span class="hlt">sheet</span> was discussed using this map. The results showed that large grain colonies in the R(?)-value maps lead to the formation of severe ridging in an FSS <span class="hlt">sheet</span>. PMID:23920166</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19850035938&hterms=electron+beam+atmosphere&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3Delectron%2Bbeam%2Batmosphere','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19850035938&hterms=electron+beam+atmosphere&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3Delectron%2Bbeam%2Batmosphere"><span id="translatedtitle">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('http://www.osti.gov/scitech/biblio/22303800','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/22303800"><span id="translatedtitle">Quantum tunneling resonant <span class="hlt">electron</span> transfer process in Lorentzian <span class="hlt">plasmas</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Hong, Woo-Pyo; Jung, Young-Dae</p> <p>2014-08-15</p> <p>The quantum tunneling resonant <span class="hlt">electron</span> transfer process between a positive ion and a neutral atom collision is investigated in nonthermal generalized Lorentzian <span class="hlt">plasmas</span>. The result shows that the nonthermal effect enhances the resonant <span class="hlt">electron</span> transfer cross section in Lorentzian <span class="hlt">plasmas</span>. It is found that the nonthermal effect on the classical resonant <span class="hlt">electron</span> transfer cross section is more significant than that on the quantum tunneling resonant charge transfer cross section. It is shown that the nonthermal effect on the resonant <span class="hlt">electron</span> transfer cross section decreases with an increase of the Debye length. In addition, the nonthermal effect on the quantum tunneling resonant <span class="hlt">electron</span> transfer cross section decreases with increasing collision energy. The variation of nonthermal and <span class="hlt">plasma</span> shielding effects on the quantum tunneling resonant <span class="hlt">electron</span> transfer process is also discussed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/22311133','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/22311133"><span id="translatedtitle"><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://arxiv.org/pdf/astro-ph/0008473v2','EPRINT'); return false;" href="http://arxiv.org/pdf/astro-ph/0008473v2"><span id="translatedtitle">Neutrino-<span class="hlt">electron</span> processes in a strongly magnetized thermal <span class="hlt">plasma</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/eprints/">E-print Network</a></p> <p>Stephen J. Hardy; Markus H. Thoma</p> <p>2000-11-15</p> <p>We present a new method of calculating the rate of neutrino-<span class="hlt">electron</span> interactions in a strong magnetic field based on finite temperature field theory. Using this method, in which the effect of the magnetic field on the <span class="hlt">electron</span> states is taken into account exactly, we calculate the rates of all of the lowest order neutrino-<span class="hlt">electron</span> interactions in a <span class="hlt">plasma</span>. As an example of the use of this technique, we explicitly calculate the rate at which neutrinos and antineutrinos annihilate in a highly magnetized <span class="hlt">plasma</span>, and compare that to the rate in an unmagnetized <span class="hlt">plasma</span>. The most important channel for energy deposition is the gyromagnetic absorption of a neutrino-antineutrino pair on an <span class="hlt">electron</span> or positron in the <span class="hlt">plasma</span> ($\</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://dspace.mit.edu/handle/1721.1/33937','EPRINT'); return false;" href="http://dspace.mit.edu/handle/1721.1/33937"><span id="translatedtitle"><span class="hlt">Electron</span> Bernstein wave current drive modeling in toroidal <span class="hlt">plasma</span> confinement</span></a></p> <p><a target="_blank" href="http://www.osti.gov/eprints/">E-print Network</a></p> <p>Decker, Joan, 1977-</p> <p>2005-01-01</p> <p>The steady-state confinement of tokamak <span class="hlt">plasmas</span> in a fusion reactor requires non-inductively driven toroidal currents. Radio frequency waves in the <span class="hlt">electron</span> cyclotron (EC) range of frequencies can drive localized currents ...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=20060035418&hterms=SOLITONS&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3DSOLITONS','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=20060035418&hterms=SOLITONS&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3DSOLITONS"><span id="translatedtitle">Alfvenic Solitons in Ultrarelativistic <span class="hlt">Electron</span>-Position <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>Verheest, G. S. Lakhina F.</p> <p>1997-01-01</p> <p>In <span class="hlt">electron</span>-positron <span class="hlt">plasmas</span> some of the <span class="hlt">plasma</span> modes are decoupled due to the equal charge-to-mass ratio of both species. We derive the dispersion law for a low-frequency, generalized X-mode, which exists at all angles of propagation with respect to the static magnetic field.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2001APS..DPPCO2002H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2001APS..DPPCO2002H"><span id="translatedtitle">Mating <span class="hlt">Electron</span> Beam Columns to <span class="hlt">Plasma</span> Window Apertures</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Hershcovitch, Ady</p> <p>2001-10-01</p> <p>The <span class="hlt">Plasma</span> Window is a novel apparatus that utilizes a stabilized <span class="hlt">plasma</span> arc as an interface between vacuum and atmosphere without solid material. In addition to sustaining a vacuum atmosphere interface, the <span class="hlt">plasma</span> window has a lensing effect on charged particles. The <span class="hlt">plasma</span> current generates an azimuthal magnetic field, which exerts a radial Lorentz force on charged particles moving parallel to the current channel. With proper orientation of the current direction, the Lorentz force is radially inward. This feature can be used to focus beams to a very small spot size, and to overcome beam dispersion due to scattering by atmospheric atoms and molecules. Consequently, for a number of particle beam applications, the <span class="hlt">plasma</span> window is an attractive alternative to differential pumping. Two such applications are non-vacuum <span class="hlt">electron</span> beam welding and hypersonic wind tunnel heating. Design issues that are presently under consideration involve <span class="hlt">electron</span> beam optics due to <span class="hlt">plasma</span> window lensing effects, and preventing ions and <span class="hlt">electrons</span> from entering the beam structure. Matching <span class="hlt">electron</span> beam columns to <span class="hlt">plasma</span> windows while shielding accelerating and focusing elements from <span class="hlt">plasma</span> particles to prevent breakdowns is to be discussed in the presentation.</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 id="translatedtitle">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> </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('http://adsabs.harvard.edu/abs/2002PhRvS...5l1301O','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2002PhRvS...5l1301O"><span id="translatedtitle">Dynamic focusing of an <span class="hlt">electron</span> beam through a long <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>O'Connell, C.; Decker, F.-J.; Hogan, M. J.; Iverson, R.; Raimondi, P.; Siemann, R. H.; Walz, D.; Blue, B.; Clayton, C. E.; Joshi, C.; Marsh, K. A.; Mori, W. B.; Wang, S.; Katsouleas, T.; Lee, S.; Muggli, P.</p> <p>2002-12-01</p> <p>The focusing effects of a 1.4m long, (0-2)×1014 cm-3 <span class="hlt">plasma</span> on a single 28.5GeV <span class="hlt">electron</span> bunch are studied experimentally in the underdense or blowout regime, where the beam density is much greater than the <span class="hlt">plasma</span> density. As the beam propagates through the <span class="hlt">plasma</span>, the density of <span class="hlt">plasma</span> <span class="hlt">electrons</span> along the incoming bunch drops from the ambient density to zero leaving a pure ion channel for the bulk of the beam. Thus, from the head of the beam up to the point where all <span class="hlt">plasma</span> <span class="hlt">electrons</span> are blown out, each successive longitudinal slice of the bunch experiences a different focusing force due to the <span class="hlt">plasma</span> ions. The time-changing focusing force results in a different number of betatron oscillations for each slice depending upon its location within the bunch. By using an <span class="hlt">electron</span> beam that has a correlated energy spread, this time-dependent focusing of the <span class="hlt">electron</span> bunch has been observed by measuring the beam spot size in the image plane of a magnetic energy spectrometer placed at the <span class="hlt">plasma</span> exit.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/22267801','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/22267801"><span id="translatedtitle">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://www.ncbi.nlm.nih.gov/pubmed/26573995','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/26573995"><span id="translatedtitle">Stability of two-dimensional PN monolayer <span class="hlt">sheets</span> and their <span class="hlt">electronic</span> properties.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Ma, ShuangYing; He, Chaoyu; Sun, L Z; Lin, Haiping; Li, Youyong; Zhang, K W</p> <p>2015-11-25</p> <p>Three two-dimensional phosphorus nitride (PN) monolayer <span class="hlt">sheets</span> (named as ?-, ?-, and ?-PN, respectively) with fantastic structures and properties are predicted based on first-principles calculations. The ?-PN and ?-PN have a buckled structure, whereas ?-PN shows puckered characteristics. Their unique structures endow these atomic PN <span class="hlt">sheets</span> with high dynamic stabilities and anisotropic mechanical properties. They are all indirect semiconductors and their band gap sensitively depends on the in-plane strain. Moreover, the nanoribbons patterned from these three PN monolayers demonstrate a remarkable quantum size effect. In particular, the zigzag ?-PN nanoribbon shows size-dependent ferromagnetism. Their significant properties show potential in nano-<span class="hlt">electronics</span>. The synthesis of the three phases of the PN monolayer <span class="hlt">sheet</span> is proposed theoretically, which is deserving of further study in experiments. PMID:26573995</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 id="translatedtitle">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('http://www.osti.gov/scitech/servlets/purl/968512','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/968512"><span id="translatedtitle">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> bunches. Chapters four and five present the experimental diagnostics and measurements for the trapped <span class="hlt">electrons</span>. Next, the sixth chapter introduces suggestions for future trapped <span class="hlt">electron</span> experiments. Then, Chapter seven contains the conclusions. In addition, there is an appendix chapter that covers a topic which is extraneous to <span class="hlt">electron</span> trapping, but relevant to the PWFA. This chapter explores the feasibility of one idea for the production of a hollow channel <span class="hlt">plasma</span>, which if produced could solve some of the remaining issues for a <span class="hlt">plasma</span>-based collider.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.df.uba.ar/users/dasso/publications/papers_df/_2009_weygand09_jgr_anisot_SWyPS.pdf','EPRINT'); return false;" href="http://www.df.uba.ar/users/dasso/publications/papers_df/_2009_weygand09_jgr_anisot_SWyPS.pdf"><span id="translatedtitle">Anisotropy of the Taylor scale and the correlation scale in <span class="hlt">plasma</span> <span class="hlt">sheet</span> and solar wind magnetic field fluctuations</span></a></p> <p><a target="_blank" href="http://www.osti.gov/eprints/">E-print Network</a></p> <p>Dasso, Sergio</p> <p></p> <p>Anisotropy of the Taylor scale and the correlation scale in <span class="hlt">plasma</span> <span class="hlt">sheet</span> and solar wind magnetic and C. Mouikis4 Received 23 September 2008; revised 2 April 2009; accepted 13 April 2009; published 14 and the solar wind are employed to determine the correlation scale and the magnetic Taylor microscale from</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://space.unh.edu/~rlk/research/reprints/jgr_108_1215_2003.pdf','EPRINT'); return false;" href="http://space.unh.edu/~rlk/research/reprints/jgr_108_1215_2003.pdf"><span id="translatedtitle">Correction to ``Three-dimensional analyses of electric currents and pressure anisotropies in the <span class="hlt">plasma</span> <span class="hlt">sheet</span>'' by Richard L. Kaufmann,</span></a></p> <p><a target="_blank" href="http://www.osti.gov/eprints/">E-print Network</a></p> <p>Kaufmann, Richard L.</p> <p></p> <p>Correction to ``Three-dimensional analyses of electric currents and pressure anisotropies. Paterson, and L. A. Frank, Correction to ``Three-dimensional analyses of electric currents and pressure] In the paper ``Three-dimensional analyses of electric currents and pressure anisotropies 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/2015JPhCS.653a2159V','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015JPhCS.653a2159V"><span id="translatedtitle">Movement of <span class="hlt">electron</span> when recombining in hydrogen <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>Vikhrev, V. V.</p> <p>2015-11-01</p> <p>An analytical model and the results of modeling are presented for movement of <span class="hlt">electrons</span> in recombining hydrogen <span class="hlt">plasma</span>. It is shown that in case of taking into account the magnetic moment and angular momentum as well as spin flip of <span class="hlt">electron</span> in magnetic field the <span class="hlt">electron</span> comes to the orbit with angular momentum ?/2. If azimuthal and radial components of kinetic energy of <span class="hlt">electron</span> are equal then the full energy of such the orbits is 13.6 eV.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013PhPl...20c4502S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013PhPl...20c4502S"><span id="translatedtitle"><span class="hlt">Plasma</span> parameters and <span class="hlt">electron</span> energy distribution functions in a magnetically focused <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>Samuell, C. M.; Blackwell, B. D.; Howard, J.; Corr, C. S.</p> <p>2013-03-01</p> <p>Spatially resolved measurements of ion density, <span class="hlt">electron</span> temperature, floating potential, and the <span class="hlt">electron</span> energy distribution function (EEDF) are presented for a magnetically focused <span class="hlt">plasma</span>. The measurements identify a central <span class="hlt">plasma</span> column displaying Maxwellian EEDFs at an <span class="hlt">electron</span> temperature of about 5 eV indicating the presence of a significant fraction of <span class="hlt">electrons</span> in the inelastic energy range (energies above 15 eV). It is observed that the EEDF remains Maxwellian along the axis of the discharge with an increase in density, at constant <span class="hlt">electron</span> temperature, observed in the region of highest magnetic field strength. Both <span class="hlt">electron</span> density and temperature decrease at the <span class="hlt">plasma</span> radial edge. <span class="hlt">Electron</span> temperature isotherms measured in the downstream region are found to coincide with the magnetic field lines.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/22085998','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/22085998"><span id="translatedtitle">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/biblio/5399267','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/5399267"><span id="translatedtitle">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 id="translatedtitle"><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('http://adsabs.harvard.edu/abs/2014JPhCS.529a2017K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014JPhCS.529a2017K"><span id="translatedtitle">Electrical conductivity of strongly degenerate <span class="hlt">plasma</span> with the account of <span class="hlt">electron-electron</span> scattering</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Karakhtanov, V. S.</p> <p>2014-08-01</p> <p>The influence of <span class="hlt">electron-electron</span> scattering on the strongly degenerate <span class="hlt">plasma</span> conductivity is investigated with a linear response theory. In the present work the temperature dependence of the <span class="hlt">electron-electron</span> scattering term of the electrical conductivity and further modification of the Ziman formula are discussed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/21359349','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/21359349"><span id="translatedtitle">Influence of <span class="hlt">electron</span> velocity distribution on the <span class="hlt">plasma</span> expansion features</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Shokoohi, R.; Abbasi, H.</p> <p>2009-08-01</p> <p>Collisionless <span class="hlt">plasma</span> expansion into vacuum is addressed emphasizing on the kinetic effects associated with the <span class="hlt">plasma</span> <span class="hlt">electrons</span>. It is an important issue since there are situations in which the <span class="hlt">plasmas</span> are in nonequilibrium state. Thus, the <span class="hlt">electron</span> distribution function (DF) that is generally non-Maxwellian has to be modeled. For this purpose, the generalized Lorentzian (kappa) DF is used to simulate the <span class="hlt">electron</span> DF. The Maxwellian and kappa distributions differ substantially in a high-energy tail. Thus, the <span class="hlt">electron</span> dynamics is studied by the Vlasov equation. Neglecting the ion temperatures, fluid equations are used for them. It is shown that by increasing the population of energetic <span class="hlt">electrons</span>, the expansion takes place faster, the resulting electric field is stronger, and the ions are accelerated to higher energy.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2005ApPhL..86b3509T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2005ApPhL..86b3509T"><span id="translatedtitle">Magnetic suppression of secondary <span class="hlt">electrons</span> in <span class="hlt">plasma</span> immersion ion implantation</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Tan, Ing Hwie; Ueda, Mario; Dallaqua, Renato S.; Rossi, Jose O.</p> <p>2005-01-01</p> <p>In this work, magnetic suppression of secondary <span class="hlt">electrons</span> in <span class="hlt">plasma</span> immersion ion implantation is demonstrated experimentally in a vacuum arc system. Secondary <span class="hlt">electrons</span> emitted normally to a copper sample surface were detected by a Faraday cup, whose signal exhibited large negative spikes coincident with high voltage pulses when aluminum ions of an unmagnetized <span class="hlt">plasma</span> were implanted. When a 12.5 mT magnetic field parallel to the sample's surface is applied, these spikes are not seen, showing that secondary <span class="hlt">electrons</span> were magnetically suppressed. Another cup, oriented to detect <span class="hlt">electrons</span> that flow along the field lines, does not exhibit such negative spikes in either unmagnetized or magnetized <span class="hlt">plasmas</span>, indicating that a virtual cathode was formed by the trapped secondary <span class="hlt">electrons</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/22218490','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/22218490"><span id="translatedtitle">Transition of <span class="hlt">electron</span> kinetics in weakly magnetized inductively coupled <span class="hlt">plasmas</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Kim, Jin-Yong; Lee, Hyo-Chang; Kim, Young-Do; Chung, Chin-Wook; Kim, Young-Cheol</p> <p>2013-10-15</p> <p>Transition of the <span class="hlt">electron</span> kinetics from nonlocal to local regime was studied in weakly magnetized solenoidal inductively coupled <span class="hlt">plasma</span> from the measurement of the <span class="hlt">electron</span> energy probability function (EEPF). Without DC magnetic field, the discharge property was governed by nonlocal <span class="hlt">electron</span> kinetics at low gas pressure. The <span class="hlt">electron</span> temperatures were almost same in radial position, and the EEPFs in total <span class="hlt">electron</span> energy scale were radially coincided. However, when the DC magnetic field was applied, radial non-coincidence of the EEPFs in total <span class="hlt">electron</span> energy scale was observed. The <span class="hlt">electrons</span> were cooled at the discharge center where the <span class="hlt">electron</span> heating is absent, while the <span class="hlt">electron</span> temperature was rarely changed at the discharge boundary with the magnetic field. These changes show the transition from nonlocal to local <span class="hlt">electron</span> kinetics and the transition is occurred when the <span class="hlt">electron</span> gyration diameter was smaller than the skin depth. The nonlocal to local transition point almost coincided with the calculation results by using nonlocal parameter and collision parameter.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2009APS..GEC.BM002K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009APS..GEC.BM002K"><span id="translatedtitle">Nonlocal collisionless and collisional <span class="hlt">electron</span> transport in low temperature <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>Kaganovich, Igor</p> <p>2009-10-01</p> <p>The purpose of the talk is to describe recent advances in nonlocal <span class="hlt">electron</span> kinetics in low-pressure <span class="hlt">plasmas</span>. A distinctive property of partially ionized <span class="hlt">plasmas</span> is that such <span class="hlt">plasmas</span> are always in a non-equilibrium state: the <span class="hlt">electrons</span> are not in thermal equilibrium with the neutral species and ions, and the <span class="hlt">electrons</span> are also not in thermodynamic equilibrium within their own ensemble, which results in a significant departure of the <span class="hlt">electron</span> velocity distribution function 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. Typical phenomena in such discharges include nonlocal <span class="hlt">electron</span> kinetics, nonlocal electrodynamics with collisionless <span class="hlt">electron</span> heating, and nonlinear processes in the sheaths and in the bounded <span class="hlt">plasmas</span>. Significant progress in understanding the interaction of electromagnetic fields with real bounded <span class="hlt">plasma</span> created by this field and the resulting changes in the structure of the applied electromagnetic field has been one of the major achievements of the last decade in this area of research [1-3]. We show on specific examples that this progress was made possible by synergy between full scale particle-in-cell simulations, analytical models, and experiments. In collaboration with Y. Raitses, A.V. Khrabrov, Princeton <span class="hlt">Plasma</span> Physics Laboratory, Princeton, NJ, USA; V.I. Demidov, UES, Inc., 4401 Dayton-Xenia Rd., Beavercreek, OH 45322, USA and AFRL, Wright-Patterson AFB, OH 45433, USA; and D. Sydorenko, University of Alberta, Edmonton, Canada. [4pt] [1] D. Sydorenko, A. Smolyakov, I. Kaganovich, and Y. Raitses, IEEE Trans. <span class="hlt">Plasma</span> Science 34, 895 (2006); Phys. <span class="hlt">Plasmas</span> 13, 014501 (2006); 14 013508 (2007); 15, 053506 (2008). [0pt] [2] I. D. Kaganovich, Y. Raitses, D. Sydorenko, and A. Smolyakov, Phys. <span class="hlt">Plasmas</span> 14, 057104 (2007). [0pt] [3] V.I. Demidov, C.A. DeJoseph, and A.A. Kudryavtsev, Phys. Rev. Lett. 95, 215002 (2005); V.I. Demidov, C.A. DeJoseph, J. Blessington, and M.E. Koepke, Europhysics News, 38, 21 (2007).</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/21124056','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/21124056"><span id="translatedtitle">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('http://www.osti.gov/scitech/biblio/20861387','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/20861387"><span id="translatedtitle">Simulation of <span class="hlt">sheet</span>-shaped lithium beam probe performance for two-dimensional edge <span class="hlt">plasma</span> measurement</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Tsuchiya, H.; Morisaki, T.; Komori, A.; Motojima, O.</p> <p>2006-10-15</p> <p>A <span class="hlt">sheet</span>-shaped thermal lithium beam probe has been developed for two-dimensional density measurements in the edge region of the torus <span class="hlt">plasma</span>. A numerical simulation was carried out to confirm the validity of the diagnostics for fast and transient phenomena such as edge localized modes or blobs, etc., where the velocity of blobs is faster than that of the probe beam. It was found in the simulation that the density of the blob itself is reconstructed to be low and unexpected ghosts appear in the reconstructed density profile near the blob, if the conventional reconstruction method is employed. These results invite our attention to the numerical errors in the density reconstruction process. On the other hand, the errors can be corrected by using the simulation results.</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 id="translatedtitle">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> </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://www.osti.gov/scitech/biblio/22089521','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/22089521"><span id="translatedtitle">Secondary-<span class="hlt">electrons</span>-induced cathode <span class="hlt">plasma</span> in a relativistic magnetron</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Queller, T.; Gleizer, J. Z.; Krasik, Ya. E.</p> <p>2012-11-19</p> <p>Results of time- and space-resolved spectroscopic studies of cathode <span class="hlt">plasma</span> during a S-band relativistic magnetron operation and a magnetically insulated diode having an identical interelectrode gap are presented. It was shown that in the case of the magnetron operation, one obtains an earlier, more uniform <span class="hlt">plasma</span> formation due to energetic <span class="hlt">electrons</span>' interaction with the cathode surface and ionization of desorbed surface monolayers. No differences were detected in the cathode's <span class="hlt">plasma</span> temperature between the magnetron and the magnetically insulated diode operation, and no anomalous fast cathode <span class="hlt">plasma</span> expansion was observed in the magnetron at rf power up to 350 MW.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/21537669','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/21537669"><span id="translatedtitle"><span class="hlt">Electron</span> inertia effects on the planar <span class="hlt">plasma</span> sheath problem</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Duarte, V. N.; Clemente, R. A.</p> <p>2011-04-15</p> <p>The steady one-dimensional planar <span class="hlt">plasma</span> sheath problem, originally considered by Tonks and Langmuir, is revisited. Assuming continuously generated free-falling ions and isothermal <span class="hlt">electrons</span> and taking into account <span class="hlt">electron</span> inertia, it is possible to describe the problem in terms of three coupled integro-differential equations that can be numerically integrated. The inclusion of <span class="hlt">electron</span> inertia in the model allows us to obtain the value of the <span class="hlt">plasma</span> floating potential as resulting from an <span class="hlt">electron</span> density discontinuity at the walls, where the <span class="hlt">electrons</span> attain sound velocity and the electric potential is continuous. Results from numerical computation are presented in terms of plots for densities, electric potential, and particles velocities. Comparison with results from literature, corresponding to <span class="hlt">electron</span> Maxwell-Boltzmann distribution (neglecting <span class="hlt">electron</span> inertia), is also shown.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://surface.iphy.ac.cn/sf03/articles/Electron%20cyclotron%20wave%20resonance%20plasma%20assisted%20deposition.pdf','EPRINT'); return false;" href="http://surface.iphy.ac.cn/sf03/articles/Electron%20cyclotron%20wave%20resonance%20plasma%20assisted%20deposition.pdf"><span id="translatedtitle"><span class="hlt">Electron</span> cyclotron wave resonance <span class="hlt">plasma</span> assisted deposition of cubic boron nitride thin films</span></a></p> <p><a target="_blank" href="http://www.osti.gov/eprints/">E-print Network</a></p> <p>Zexian, Cao</p> <p></p> <p><span class="hlt">Electron</span> cyclotron wave resonance <span class="hlt">plasma</span> assisted deposition of cubic boron nitride thin films Z. X-pressure <span class="hlt">plasma</span> source. The <span class="hlt">electron</span>-cyclotron-wave resonance ECWR <span class="hlt">plasma</span> served both to sputter the hBN target</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/22420281','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/22420281"><span id="translatedtitle">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 <span class="hlt">plasma</span>–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('http://adsabs.harvard.edu/abs/2015ApPhL.106e3703L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015ApPhL.106e3703L"><span id="translatedtitle">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://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Lunov, O.; Churpita, O.; Zablotskii, V.; Deyneka, I. G.; Meshkovskii, I. K.; Jäger, A.; Syková, E.; Kubinová, Š.; Dejneka, A.</p> <p>2015-02-01</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 <span class="hlt">plasma</span>-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('http://www.osti.gov/scitech/biblio/22072533','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/22072533"><span id="translatedtitle">Three-wave coupling in <span class="hlt">electron</span>-positron-ion <span class="hlt">plasmas</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Tinakiche, N.; Annou, R.; Tripathi, V. K.</p> <p>2012-07-15</p> <p>The three-wave coupling processes in <span class="hlt">electron</span>-positron-ion <span class="hlt">plasmas</span> are investigated. The non-linear dispersion relation is derived along with the non-linear growth rate in both resonant and non resonant processes. It is shown that the inclusion of positron affects the dielectric properties of the <span class="hlt">plasma</span> as well as the nonlinear growth rates of parametric processes. As one increases the positron density to <span class="hlt">electron</span> density ratio from 0 to 1, maintaining quasi neutrality of the <span class="hlt">plasma</span>, the growth rates of stimulated Raman, Brillouin, and Compton scattering processes in an isothermal <span class="hlt">plasma</span> tend to zero due to the ponderomotive forces acting on <span class="hlt">electrons</span> and positrons due the pump and scattered waves being equal.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/22303448','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/22303448"><span id="translatedtitle"><span class="hlt">Electron</span> energy distributions in a magnetized inductively coupled <span class="hlt">plasma</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Song, Sang-Heon E-mail: Sang-Heon.Song@us.tel.com; Yang, Yang; Kushner, Mark J.</p> <p>2014-09-15</p> <p>Optimizing and controlling <span class="hlt">electron</span> energy distributions (EEDs) is a continuing goal in <span class="hlt">plasma</span> materials processing as EEDs determine the rate coefficients for <span class="hlt">electron</span> impact processes. There are many strategies to customize EEDs in low pressure inductively coupled <span class="hlt">plasmas</span> (ICPs), for example, pulsing and choice of frequency, to produce the desired <span class="hlt">plasma</span> properties. Recent experiments have shown that EEDs in low pressure ICPs can be manipulated through the use of static magnetic fields of sufficient magnitudes to magnetize the <span class="hlt">electrons</span> and confine them to the electromagnetic skin depth. The EED is then a function of the local magnetic field as opposed to having non-local properties in the absence of the magnetic field. In this paper, EEDs in a magnetized inductively coupled <span class="hlt">plasma</span> (mICP) sustained in Ar are discussed with results from a two-dimensional <span class="hlt">plasma</span> hydrodynamics model. Results are compared with experimental measurements. We found that the character of the EED transitions from non-local to local with application of the static magnetic field. The reduction in cross-field mobility increases local <span class="hlt">electron</span> heating in the skin depth and decreases the transport of these hot <span class="hlt">electrons</span> to larger radii. The tail of the EED is therefore enhanced in the skin depth and depressed at large radii. <span class="hlt">Plasmas</span> densities are non-monotonic with increasing pressure with the external magnetic field due to transitions between local and non-local kinetics.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/22408263','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/22408263"><span id="translatedtitle">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('http://hdl.handle.net/2060/19850004205','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19850004205"><span id="translatedtitle">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://ntrs.nasa.gov/search.jsp?R=19850051341&hterms=cold+plasma&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3Dcold%2Bplasma','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19850051341&hterms=cold+plasma&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3Dcold%2Bplasma"><span id="translatedtitle">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('http://www.osti.gov/scitech/biblio/22218608','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/22218608"><span id="translatedtitle">Coupled <span class="hlt">electron</span> and ion nonlinear oscillations in a collisionless <span class="hlt">plasma</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Karimov, A. R.</p> <p>2013-05-15</p> <p>Dynamics of coupled electrostatic <span class="hlt">electron</span> and ion nonlinear oscillations in a collisionless <span class="hlt">plasma</span> is studied with reference to a kinetic description. Proceeding from the exact solution of Vlasov-Maxwell equations written as a function of linear functions in the <span class="hlt">electron</span> and ion velocities, we arrive at the two coupled nonlinear equations which describe the evolution of the system.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/22399196','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/22399196"><span id="translatedtitle">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://aero.uc3m.es/ep2/docs/publicaciones/corr15a.pdf','EPRINT'); return false;" href="http://aero.uc3m.es/ep2/docs/publicaciones/corr15a.pdf"><span id="translatedtitle">Collisionless <span class="hlt">electron</span> cooling on magnetized <span class="hlt">plasma</span> expansions: advances on modelling</span></a></p> <p><a target="_blank" href="http://www.osti.gov/eprints/">E-print Network</a></p> <p>Carlos III de Madrid, Universidad</p> <p></p> <p>-117/ISTS-2015-b-117 Presented at Joint Conference of 30th International Symposium on Space Technology through a magnetic nozzle channel (quasi-1D). At the <span class="hlt">plasma</span> reservoir, far upstream from the magnetic nozzle throat, <span class="hlt">electrons</span> and ions are considered fully Maxwellian. Ion and <span class="hlt">electron</span> distribution</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015PlPhR..41..737V','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015PlPhR..41..737V"><span id="translatedtitle"><span class="hlt">Electron</span>-ion relaxation time in moderately degenerate <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>Vronskii, M. A.; Koryakina, Yu. V.</p> <p>2015-09-01</p> <p>A formula is derived for the <span class="hlt">electron</span>-ion relaxation time in a partially degenerate <span class="hlt">plasma</span> with <span class="hlt">electron</span>-ion interaction via a central field. The resulting expression in the form of an integral of the transport cross section generalizes the well-known Landau and Brysk approximations.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015JPhCS.642a2030Y','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015JPhCS.642a2030Y"><span id="translatedtitle">Solar Wind <span class="hlt">Electron</span> Energization by <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>Yoon, P. H.</p> <p>2015-09-01</p> <p>The solar wind <span class="hlt">electrons</span> are made of the low-energy Maxwellian core, intermediate-energy halo, field-aligned strahl, and the highly-energetic super-halo <span class="hlt">electrons</span>. The present paper discusses a model in which the halo <span class="hlt">electrons</span> interact with the whistler fluctuation via cyclotron wave-particle resonance, and the super-halo <span class="hlt">electrons</span> interact through Landau resonance with the Langmuir fluctuation, thus maintaining a local steady state.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/doepatents/biblio/870998','DOE-PATENT-XML'); return false;" href="http://www.osti.gov/doepatents/biblio/870998"><span id="translatedtitle">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 (Ann Arbor, MI); Esarey, Eric (Chevy Chase, MD); Kim, Joon K. (Ann Arbor, MI)</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://www.osti.gov/doepatents/biblio/489098','DOE-PATENT-XML'); return false;" href="http://www.osti.gov/doepatents/biblio/489098"><span id="translatedtitle">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://ntrs.nasa.gov/search.jsp?R=19820058707&hterms=bpd&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3Dbpd','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19820058707&hterms=bpd&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3Dbpd"><span id="translatedtitle">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://www.osti.gov/scitech/biblio/6685054','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/6685054"><span id="translatedtitle">Suprathermal <span class="hlt">electrons</span> produced by Beam-<span class="hlt">Plasma</span>-Discharge</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Sharp, W.E.</p> <p>1982-08-01</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://www.osti.gov/scitech/biblio/22068878','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/22068878"><span id="translatedtitle">Kinetic description of <span class="hlt">electron</span> <span class="hlt">plasma</span> waves with orbital angular momentum</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Mendonca, J. T.</p> <p>2012-11-15</p> <p>We describe the kinetic theory of <span class="hlt">electron</span> <span class="hlt">plasma</span> waves with orbital angular momentum or twisted plasmons. The conditions for a twisted Landau resonance to exist are established, and this concept is introduced for the first time. Expressions for the kinetic dispersion relation and for the <span class="hlt">electron</span> Landau damping are derived. The particular case of a Maxwellian <span class="hlt">plasma</span> is examined in detail. The new contributions to wave dispersion and damping due the orbital angular momentum are discussed. It is shown that twisted plasmons can be excited by rotating <span class="hlt">electron</span> beams.</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://adsabs.harvard.edu/abs/2010ApPhL..96g1502F','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010ApPhL..96g1502F"><span id="translatedtitle">A high current density <span class="hlt">plasma</span> cathode <span class="hlt">electron</span> gun</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Fu, Wenjie; Yan, Yang; Li, Wenxu; Li, Xiaoyun; Wu, Jianqiang</p> <p>2010-02-01</p> <p>The design, performance, and characteristics of a <span class="hlt">plasma</span> cathode <span class="hlt">electron</span> gun are presented. The <span class="hlt">plasma</span> cathode is based on a hollow cathode direct current discharge, and the <span class="hlt">electron</span> beam is accelerated by pulse voltage. By discharging at high gas pressure and operating at low gas pressure, both the maximum accelerating voltage and maximum emitting current could be increased. Utilizing argon, with the accelerating voltage up to 9 kV and gas pressure down to 52 mPa, the gun is able to generate an <span class="hlt">electron</span> beam of about 4.7 A, and the corresponding emitting current density is about 600 A/cm2.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/21347274','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/21347274"><span id="translatedtitle">A high current density <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>Fu Wenjie; Yan Yang; Li Wenxu; Li Xiaoyun; Wu Jianqiang</p> <p>2010-02-15</p> <p>The design, performance, and characteristics of a <span class="hlt">plasma</span> cathode <span class="hlt">electron</span> gun are presented. The <span class="hlt">plasma</span> cathode is based on a hollow cathode direct current discharge, and the <span class="hlt">electron</span> beam is accelerated by pulse voltage. By discharging at high gas pressure and operating at low gas pressure, both the maximum accelerating voltage and maximum emitting current could be increased. Utilizing argon, with the accelerating voltage up to 9 kV and gas pressure down to 52 mPa, the gun is able to generate an <span class="hlt">electron</span> beam of about 4.7 A, and the corresponding emitting current density is about 600 A/cm{sup 2}.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/6525482','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/6525482"><span id="translatedtitle">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> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/22118560','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/22118560"><span id="translatedtitle">Two-dimensional-spatial distribution measurement of <span class="hlt">electron</span> temperature and <span class="hlt">plasma</span> density in low temperature <span class="hlt">plasmas</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Kim, Young-Cheol; Jang, Sung-Ho; Oh, Se-Jin; Lee, Hyo-Chang; Chung, Chin-Wook</p> <p>2013-05-15</p> <p>A real-time measurement method for two-dimensional (2D) spatial distribution of the <span class="hlt">electron</span> temperature and <span class="hlt">plasma</span> density was developed. The method is based on the floating harmonic method and the real time measurement is achieved with little <span class="hlt">plasma</span> perturbation. 2D arrays of the sensors on a 300 mm diameter wafer-shaped printed circuit board with a high speed multiplexer circuit were used. Experiments were performed in an inductive discharge under various external conditions, such as powers, gas pressures, and different gas mixing ratios. The results are consistent with theoretical prediction. Our method can measure the 2D spatial distribution of <span class="hlt">plasma</span> parameters on a wafer-level in real-time. This method can be applied to <span class="hlt">plasma</span> diagnostics to improve the <span class="hlt">plasma</span> uniformity of <span class="hlt">plasma</span> reactors for <span class="hlt">plasma</span> processing.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19720029854&hterms=electron+backscattering&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D60%26Ntt%3Delectron%2Bbackscattering','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19720029854&hterms=electron+backscattering&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D60%26Ntt%3Delectron%2Bbackscattering"><span id="translatedtitle">Probe and radar <span class="hlt">electron</span> temperatures in an isotropic nonequilibrium <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>Hoegy, W. R.</p> <p>1971-01-01</p> <p><span class="hlt">Electron</span> temperatures measured by electrostatic probes and radar backscatter are distinct physical quantities, the temperature from each technique determined from a different moment of the <span class="hlt">electron</span>-distribution function. Numerical inequality of temperatures results from a non-Maxwellian <span class="hlt">electron</span>-distribution function or, equivalently, from a nonequilibrium <span class="hlt">electron</span> <span class="hlt">plasma</span>. Probe and backscatter <span class="hlt">electron</span> temperatures are studied for low- and high-energy (isotropic) distortions of the distribution function. The nonequilibrium <span class="hlt">plasma</span> generally produces higher probe than backscatter temperatures; however, the temperature difference is small for distortions due to realistic photoelectron populations. If the ionosphere is in a highly nonequilibrium state, probe and backscatter temperatures would differ from the temperature characterizing the average <span class="hlt">electron</span> kinetic energy, and a single temperature applicable to a variety of physical processes would no longer exist.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/797847','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/797847"><span id="translatedtitle">Synchrotron radiation from <span class="hlt">electron</span> beams in <span class="hlt">plasma</span> focusing channels</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Esarey, E.; Shadwick, B.A.; Catravas, P.; Leemans, W.P.</p> <p>2001-12-06</p> <p>Spontaneous radiation emitted from relativistic <span class="hlt">electrons</span> undergoing betatron motion in a <span class="hlt">plasma</span> focusing channel is analyzed and application to <span class="hlt">plasma</span> wakefield accelerator experiments and to the ion channel laser (ICL) are discussed. Important similarities and differences between a free <span class="hlt">electron</span> laser (FEL) and an ICL are delineated. It is shown that the frequency of spontaneous radiation is a strong function of the betatron strength parameter alpha-beta, which plays a similar role to that of the wiggler strength parameter in a conventional FEL. For alpha-beta > 1, radiation is emitted in numerous harmonics. Furthermore, alpha-beta is proportional to the amplitude of the betatron orbit, which varies for every <span class="hlt">electron</span> in the beam. The radiation spectrum emitted from an <span class="hlt">electron</span> beam is calculated by averaging the single <span class="hlt">electron</span> spectrum over the <span class="hlt">electron</span> distribution. This leads to a frequency broadening of the radiation spectrum, which places serious limits on the possibility of realizing an ICL.</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 id="translatedtitle">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://adsabs.harvard.edu/abs/2015AIPC.1670c0031S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015AIPC.1670c0031S"><span id="translatedtitle">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://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Shrivastava, G.; Shrivastava, J.; Ahirwar, G.</p> <p>2015-07-01</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 ? 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 (Ti/Te), 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/6045278','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/6045278"><span id="translatedtitle">Collective ion acceleration by relativistic <span class="hlt">electron</span> beams in <span class="hlt">plasmas</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Galvez, M.; Gisler, G. )</p> <p>1991-01-01</p> <p>A two-dimensional fully electromagnetic particle-in-cell code is used to simulate the interaction of a relativistic <span class="hlt">electron</span> beam injected into a finite-size background neutral <span class="hlt">plasma</span>. The simulations show that the background <span class="hlt">electrons</span> are pushed away from the beam path, forming a neutralizing ion channel. Soon after the beam head leaves the <span class="hlt">plasma</span>, a virtual cathode forms which travels away with the beam. However, at later times a second, quasi-stationary, virtual cathode forms. Its position and strength depends critically on the parameters of the system which critically determines the efficiency of the ion acceleration process. The background ions trapped in the electrostatic well of the virtual cathode are accelerated and at later times, the ions as well as the virtual cathode drift away from the <span class="hlt">plasma</span> region. The surfing of the ions in the electrostatic well produces an ion population with energies several times the initial <span class="hlt">electron</span> beam energy. It is found that optimum ion acceleration occurs when the beam-to-<span class="hlt">plasma</span> density ratio is near unity. When the <span class="hlt">plasma</span> is dense, the beam is a weak perturbation and accelerates few ions, while when the <span class="hlt">plasma</span> is tenuous, the beam is not effectively neutralized, and a virtual cathode occurs right at the injection plane. The simulations also show that, at the virtual cathode position, the <span class="hlt">electron</span> beam is pinched producing a self-focusing phenomena.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/doepatents/biblio/6734987','DOE-PATENT-XML'); return false;" href="http://www.osti.gov/doepatents/biblio/6734987"><span id="translatedtitle">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('http://adsabs.harvard.edu/abs/2003AIPC..669..358B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2003AIPC..669..358B"><span id="translatedtitle">Fore-Vacuum <span class="hlt">Plasma</span> <span class="hlt">Electron</span> Gun of Ribbon Beam</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Burdovitsin, Viktor; Burachevsky, Yurii; Oks, Efim; Fedorov, Michael</p> <p>2003-06-01</p> <p><span class="hlt">Plasma</span> <span class="hlt">electron</span> gun for ribbon beam generation was designed on the basis of glow discharge with hollow cathode. <span class="hlt">Electrons</span> were extracted through emission hole in the anode from <span class="hlt">plasma</span> boundary, stabilized by metal mesh, and accelerated by the voltage applied between the anode and extractor. <span class="hlt">Electron</span> beam was of 25 cm width, 1 cm thickness. Beam current and energy were of 0.1-1 A and 2-6 keV respectively, at gas pressure of 10 - 60 mTorr. Maximum parameters are defined mostly by the acceleration gap geometry. Current density distribution along the beam width depends on the gas pressure and total beam current. At pressures higher than 30 mTorr local current maximums appear in the <span class="hlt">electron</span> beam. They look as streams, and their positions are determined by the anode mesh deviation from flatness, but they are always at the edges of the beam. Our experiments show that in the absence of <span class="hlt">electron</span> emission <span class="hlt">plasma</span> density distribution in a hollow cathode maintains maximums at edges but their amounts are not more than 5 percents. At the same time, local beam maximums are about two times more. It means there is another reason of non-uniformity. We believe this intensifying is caused by gas ionization in the acceleration gap and back-stream ion flow to discharge <span class="hlt">plasma</span>. Recharging in <span class="hlt">plasma</span>, these ions increase <span class="hlt">plasma</span> density and that, in its turn, leads to stream intensifying and so on. Local <span class="hlt">plasma</span> density growth is balanced by ion diffusion from this excite zone. Lower pressure, lower ion back flow and lower <span class="hlt">plasma</span> non-uniformity.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015PlST...17..826Z','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015PlST...17..826Z"><span id="translatedtitle">Terahertz <span class="hlt">Plasma</span> Waves in Two Dimensional Quantum <span class="hlt">Electron</span> Gas with <span class="hlt">Electron</span> Scattering</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Zhang, Liping</p> <p>2015-10-01</p> <p>We investigate the Terahertz (THz) <span class="hlt">plasma</span> waves in a two-dimensional (2D) <span class="hlt">electron</span> gas in a nanometer field effect transistor (FET) with quantum effects, the <span class="hlt">electron</span> scattering, the thermal motion of <span class="hlt">electrons</span> and <span class="hlt">electron</span> exchange-correlation. We find that, while the <span class="hlt">electron</span> scattering, the wave number along y direction and the <span class="hlt">electron</span> exchange-correlation suppress the radiation power, but the thermal motion of <span class="hlt">electrons</span> and the quantum effects can amplify the radiation power. The radiation frequency decreases with <span class="hlt">electron</span> exchange-correlation contributions, but increases with quantum effects, the wave number along y direction and thermal motion of <span class="hlt">electrons</span>. It is worth mentioning that the <span class="hlt">electron</span> scattering has scarce influence on the radiation frequency. These properties could be of great help to the realization of practical THz <span class="hlt">plasma</span> oscillations in nanometer FET. supported by National Natural Science Foundation of China (No. 10975114)</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1997APS..GECOWP203K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1997APS..GECOWP203K"><span id="translatedtitle">Negative Ion Measurements in <span class="hlt">Electron</span> Cyclotron Resonance Etching <span class="hlt">Plasmas</span> [1</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Koo, Bon-Woong; Hershkowitz, Noah</p> <p>1997-10-01</p> <p>Negative ions are known to be the precursor for particle formation in processing <span class="hlt">plasmas</span>. Significant concentrations of negative ions have previously been identified in capacitively-coupled low pressure fluorocarbon and silane <span class="hlt">plasmas</span>, low pressure multi-dipole hydrogen <span class="hlt">plasmas</span>, etc. Negative ions can also change the <span class="hlt">plasma</span> potential, spatial <span class="hlt">plasma</span> profiles and <span class="hlt">plasma</span> density in processing <span class="hlt">plasmas</span>. Since electronegative gases are often used in <span class="hlt">plasma</span> etching, it is interesting to know what negative ion species are present. Here we report measurements of negative ions in an <span class="hlt">electron</span> cyclotron resonance (ECR) etching tool. An omegatron mass analyzer, which took advantage of the dc magnetic field in the etching tool, was used to make measurements at pressures of 0.1 5.0mTorr. The omegatron mass analyzer was geometrically modified to detect both positive and negative ions by changing the polarity and magnitude of the bias voltage of the electrodes inside the omegatron chamber. The geometry also provides differential pumping with pressure inside the omegatron below the 0.05 mTorr range, reducing collisional effects and insulating film deposition. The main goals of this study are to understand omegatron physics and (2) to measure the negative ion species in ECR etching <span class="hlt">plasmas</span>. Positive ions were also measured mainly to calibrate the ion mass in negative ion measurements. Preliminary results show H(+), H2(+), H3(+) and He(+) ions in an H2 + He <span class="hlt">plasmas</span>, H(-) and H2(-) in hydrogen <span class="hlt">plasmas</span>, N(+), N2(+) in nitrogen <span class="hlt">plasmas</span>, F(-), F2(-) in fluorocarbon ECR <span class="hlt">plasmas</span>. Recent experiments will be presented.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www-pw.physics.uiowa.edu/~dag/publications/2008_ElectronDensitiesInTheUpperIonosphereOfMarsFromTheExcitationOfElectronPlasmaOscillations_JGR.pdf','EPRINT'); return false;" href="http://www-pw.physics.uiowa.edu/~dag/publications/2008_ElectronDensitiesInTheUpperIonosphereOfMarsFromTheExcitationOfElectronPlasmaOscillations_JGR.pdf"><span id="translatedtitle"><span class="hlt">Electron</span> densities in the upper ionosphere of Mars from the excitation of <span class="hlt">electron</span> <span class="hlt">plasma</span> oscillations</span></a></p> <p><a target="_blank" href="http://www.osti.gov/eprints/">E-print Network</a></p> <p>Gurnett, Donald A.</p> <p></p> <p><span class="hlt">Electron</span> densities in the upper ionosphere of Mars from the excitation of <span class="hlt">electron</span> <span class="hlt">plasma</span> to remote radio sounding of the ionosphere of Mars, the MARSIS (Mars Advanced Radar for Subsurface and Ionospheric Sounding) instrument on the Mars Express spacecraft is also able to measure the in situ <span class="hlt">electron</span></p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1990masu.conf....3H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1990masu.conf....3H"><span id="translatedtitle">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://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Hones, E. W.; Elphinstone, R.; Murphree, J. S.; Galvin, A. B.; Heinemann, N. C.</p> <p></p> <p>One of the periods being studied 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 the Dynamics Explorer 1 (DE 1) 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 Defense Meteorological Satellite Program (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('http://adsabs.harvard.edu/abs/2014JPhCS.552a2014D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014JPhCS.552a2014D"><span id="translatedtitle">Effect of <span class="hlt">electron</span> extraction from a grid <span class="hlt">plasma</span> cathode on the generation of emission <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>Devyatkov, V. N.; Koval, N. N.</p> <p>2014-11-01</p> <p>The paper describes the operating mode of a <span class="hlt">plasma</span> <span class="hlt">electron</span> source based on a low- pressure arc discharge with grid stabilization of the <span class="hlt">plasma</span> emission boundary which provides a considerable (up to twofold) increase in discharge and beam currents at an Ar pressure in the vacuum chamber p = 0.02-0.05 Pa, accelerating voltages of up to U = 10 kV, and longitudinal magnetic field of up to Bz = 0.1 T. The discharge and beam currents are increased on <span class="hlt">electron</span> extraction from the emission <span class="hlt">plasma</span> through meshes of a fine metal grid due to the energy of a high-voltage power supply which ensures <span class="hlt">electron</span> emission and acceleration. The <span class="hlt">electron</span> emission from the <span class="hlt">plasma</span> cathode and arrival of ions from the acceleration gap in the discharge changes the discharge <span class="hlt">plasma</span> parameters near the emission grid, thus changing the potential of the emission grid electrode with respect to the discharge cathode. The load is not typical and changes the voltage polarity of the electrode gap connected to the discharge power supply, which is to be taken into account in its calculation and design. The effect of <span class="hlt">electron</span> emission from the <span class="hlt">plasma</span> cathode on the discharge system can not only change the discharge and beam current pulse shapes but can also lead to a breakdown of the acceleration gap and failure of semiconductor elements in the discharge power supply unit.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015PPCF...57h5007H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015PPCF...57h5007H"><span id="translatedtitle"><span class="hlt">Plasma</span> effects on the free-<span class="hlt">electron</span> laser gain with a <span class="hlt">plasma</span> wave undulator</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Hedayati, R.; Jafari, S.; Batebi, S.</p> <p>2015-08-01</p> <p>Employing a magnetized <span class="hlt">plasma</span> medium in the interaction region of a free-<span class="hlt">electron</span> laser (FEL) offers the possibility of generating short wavelengths using moderate energy beams. <span class="hlt">Plasma</span> in the presence of static magnetic field supports right and left circularly polarized electromagnetic modes. By superposition of these two modes, a linearly polarized electromagnetic mode is generated which can be employed as a <span class="hlt">plasma</span> undulator in a FEL. This configuration has a higher tunability by controlling the <span class="hlt">plasma</span> density on top of the ? -tubability of the conventional FELs. The roles of the axial magnetic field and <span class="hlt">plasma</span> on the laser gain and the <span class="hlt">electron</span> trajectories of an e-beam propagating through the <span class="hlt">plasma</span> medium have been studied and new orbits of group (I, II, and III) have been found. Moreover, the stability of these orbits for different values of <span class="hlt">plasma</span> frequencies has been investigated. It is shown that by increasing the axial guide magnetic field strength, the gain for orbits of group I trivially increase, while a decrease in gain has been obtained for orbits of group II and group III. In addition, it is found that with increasing the <span class="hlt">plasma</span> frequency (or <span class="hlt">plasma</span> density) the gain for orbits of group I and group II trivially decreases and shift to the lower cyclotron frequencies, while an increase in gain has been obtained for orbits of group III.</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 id="translatedtitle">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('http://www.osti.gov/scitech/biblio/21347403','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/21347403"><span id="translatedtitle">The functionalization of graphene using <span class="hlt">electron</span>-beam generated <span class="hlt">plasmas</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Baraket, M.; Walton, S. G.; Lock, E. H.; Robinson, J. T.; Perkins, F. K.</p> <p>2010-06-07</p> <p>A <span class="hlt">plasmas</span>-based, reversible functionalization of graphene is discussed. Using <span class="hlt">electron</span>-beam produced <span class="hlt">plasmas</span>, oxygen and fluorine functionalities have been added by changing the processing gas mixtures from Ar/O{sub 2} to Ar/SF{sub 6}, respectively. The reversibility of the functionalization was investigated by annealing the samples. The chemical composition and structural changes were studied by x-ray photoelectron spectroscopy and Raman spectroscopy.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/22047116','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/22047116"><span id="translatedtitle">Decays of <span class="hlt">electron</span> Bernstein waves near <span class="hlt">plasma</span> edge</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Xiang Nong; Cary, John R.</p> <p>2011-12-15</p> <p>Nonlinear wave-wave couplings near the upper hybrid resonance are studied via particle-in-cell simulations. It is found that the decay of an <span class="hlt">electron</span> Bernstein wave (EBW) depends on the ratio of the incident frequency and <span class="hlt">electron</span> cyclotron frequency. For ratios less than two, parametric decay into a lower hybrid wave (or an ion Bernstein wave) and EBWs at a lower frequency is observed. For ratios larger than two, the daughter waves could be an <span class="hlt">electron</span> cyclotron quasi-mode and another EBW or an ion wave and EBW. For sufficiently high incident power, the former process may dominate. Because of the <span class="hlt">electron</span> cyclotron quasi-mode, <span class="hlt">electrons</span> can be strongly heated by nonlinear Landau damping. As a result, the bulk of the incident power can be absorbed near <span class="hlt">plasma</span> edge at high power. The increase in number of decay channels with frequency implies that the allowable power into the <span class="hlt">plasma</span> must decrease with frequency.</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://www.osti.gov/scitech/biblio/21255224','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/21255224"><span id="translatedtitle">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('http://www.osti.gov/scitech/biblio/6384383','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/6384383"><span id="translatedtitle"><span class="hlt">Plasma</span> properties in <span class="hlt">electron</span>-bombardment ion thrusters</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Matossian, J.N.; Beattie, J.R.</p> <p>1987-05-01</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. 20 references.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://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="http://ntrs.nasa.gov/search.jsp?R=19870053861&hterms=1076&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3D%2526%25231076"><span id="translatedtitle"><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/2000RScI...71..388G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2000RScI...71..388G"><span id="translatedtitle">High current, low pressure <span class="hlt">plasma</span> cathode <span class="hlt">electron</span> gun</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Goebel, Dan M.; Watkins, Ron M.</p> <p>2000-02-01</p> <p>A <span class="hlt">plasma</span>-cathode <span class="hlt">electron</span> gun based on a moderate pressure (>5 mTorr) cold-cathode discharge and a high perveance, multiaperture accelerator was previously developed at Hughes Research Laboratories and produced <span class="hlt">electron</span> beam currents of up to 1 kA at voltages of over 200 kV for pulse lengths of 100 ?s. This gun was limited in pulse repetition frequency and duty by the gas-puff system that provided adequate gas pressure in the hollow cathode to operate the glow discharge while keeping the pressure in the beam transport region sufficiently low. We describe a new <span class="hlt">plasma</span> cathode <span class="hlt">electron</span> gun (PCE gun) that eliminates this problem by replacing the glow-discharge <span class="hlt">plasma</span> generator in the <span class="hlt">electron</span> gun by a low-pressure thermionic discharge in a magnetic multipole confinement chamber. Proper design of the <span class="hlt">plasma</span> generator and electrical circuit provides high <span class="hlt">electron</span>-current densities to the accelerator structure at very low gas pressure (<10-4 Torr). The static gas pressure permits the pulse repetition frequency to be very high (>1.5 kHz demonstrated) with <span class="hlt">electron</span> beam currents up to 200 A at voltages up to 120 kV demonstrated. The design and performance of the PCE gun, along with several models used to predict and scale the performance, are discussed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/22224163','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/22224163"><span id="translatedtitle">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, ?= 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 emigration to a preferred electrode direction. Regardless of <span class="hlt">plasma</span> electrodes positions and <span class="hlt">plasma</span> shape, ions can be departed from one electrode to deposit on the other one. In consequence, as an application the AF <span class="hlt">plasma</span> type can enhance the metal deposition from one electrode to the other.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/22303618','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/22303618"><span id="translatedtitle">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('http://adsabs.harvard.edu/abs/2014PhPl...21i2108A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014PhPl...21i2108A"><span id="translatedtitle">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('http://ntrs.nasa.gov/search.jsp?R=19920029434&hterms=electron+backscattering&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3Delectron%2Bbackscattering','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19920029434&hterms=electron+backscattering&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3Delectron%2Bbackscattering"><span id="translatedtitle">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://ntrs.nasa.gov/search.jsp?R=19800046372&hterms=Haber+process&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3D%2528Haber%2Bprocess%2529','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19800046372&hterms=Haber+process&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3D%2528Haber%2Bprocess%2529"><span id="translatedtitle">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://www.osti.gov/scitech/biblio/22317935','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/22317935"><span id="translatedtitle">Novel spin-<span class="hlt">electronic</span> properties of BC{sub 7} <span class="hlt">sheets</span> induced by strain</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Xu, Lei; Dai, ZhenHong Sui, PengFei; Sun, YuMing; Wang, WeiTian</p> <p>2014-11-01</p> <p>Based on first-principles calculations, the authors have investigated the <span class="hlt">electronic</span> and magnetic properties of BC{sub 7} <span class="hlt">sheets</span> with different planar strains. It is found that metal–semiconductor transition appears at the biaxial strain of 15.5%, and the <span class="hlt">sheets</span> are characteristic of spin-polarized semiconductor with a zero band-gap. The band-gap rapidly increases with strain, and reaches a maximum value of 0.60 eV at the strain of 20%. Subsequently, the band-gap decreases until the strain reaches up to 22% and shows a semiconductor-half metal transformation. It will further present metal properties until the strain is up to the maximum value of 35%. The magnetic moments also have some changes induced by biaxial strain. The numerical analysis shows that the two-dimensional distortions have great influences on the magnetic moments. The novel spin-<span class="hlt">electronic</span> properties make BC{sub 7} <span class="hlt">sheets</span> have potential applications in future spintronic nanodevices.</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 id="translatedtitle">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://arxiv.org/pdf/1601.00880.pdf','EPRINT'); return false;" href="http://arxiv.org/pdf/1601.00880.pdf"><span id="translatedtitle">A "slingshot" laser-driven acceleration mechanism of <span class="hlt">plasma</span> <span class="hlt">electrons</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/eprints/">E-print Network</a></p> <p>Fiore, Gaetano; Fedele, Renato</p> <p>2016-01-01</p> <p>We briefly report on the recently proposed [G. Fiore, R. Fedele, U. de Angelis, Phys. <span class="hlt">Plasmas</span> 21 (2014), 113105], [G. Fiore, S. De Nicola, arXiv:1509.04656] <span class="hlt">electron</span> acceleration mechanism named "slingshot effect": under suitable conditions the impact of an ultra-short and ultra-intense laser pulse against the surface of a low-density <span class="hlt">plasma</span> is expected to cause the expulsion of a bunch of superficial <span class="hlt">electrons</span> with high energy in the direction opposite to that of the pulse propagation; this is due to the interplay of the huge ponderomotive force, huge longitudinal field arising from charge separation, and the finite size of the laser spot.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19870029397&hterms=cold+plasma&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D70%26Ntt%3Dcold%2Bplasma','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19870029397&hterms=cold+plasma&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D70%26Ntt%3Dcold%2Bplasma"><span id="translatedtitle"><span class="hlt">Electron</span>-cyclotron maser instability in relativistic <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>Pritchett, P. L.</p> <p>1986-01-01</p> <p>The <span class="hlt">electron</span>-cyclotron maser instability is studied for the case of an anisotropic <span class="hlt">electron</span> velocity distribution in the regime where the relativistic corrections to the wave dispersion are significant. Solution of the linear dispersion relation reveals that when the <span class="hlt">plasma</span> frequency-gyrofrequency ratio is less than v(te)/c, the instability is localized just below k(perpendicular)c/Omega(e) = 1. The growth rate is then strongly peaked for emission at 90 deg to the magnetic field and is considerably larger than would be the case if the cold-<span class="hlt">plasma</span> dispersion theory were valid. These features are confirmed by EM particle simulations.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/22304083','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/22304083"><span id="translatedtitle">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/?{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://www.osti.gov/scitech/biblio/22227984','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/22227984"><span id="translatedtitle">Influence of <span class="hlt">electron</span> evaporative cooling on ultracold <span class="hlt">plasma</span> expansion</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Wilson, Truman; Chen, Wei-Ting; Roberts, Jacob</p> <p>2013-07-15</p> <p>The expansion of ultracold neutral <span class="hlt">plasmas</span> (UCP) is driven primarily by the thermal pressure of the <span class="hlt">electron</span> component and is therefore sensitive to the <span class="hlt">electron</span> temperature. For typical UCP spatial extents, evaporative cooling has a significant influence on the UCP expansion rate at lower densities (less than 10{sup 8}/cm{sup 3}). We studied the effect of <span class="hlt">electron</span> evaporation in this density range. Owing to the low density, the effects of three-body recombination were negligible. We modeled the expansion by taking into account the change in <span class="hlt">electron</span> temperature owing to evaporation as well as adiabatic expansion and found good agreement with our data. We also developed a simple model for initial evaporation over a range of ultracold <span class="hlt">plasma</span> densities, sizes, and <span class="hlt">electron</span> temperatures to determine over what parameter range <span class="hlt">electron</span> evaporation is expected to have a significant effect. We also report on a signal calibration technique, which relates the signal at our detector to the total number of ions and <span class="hlt">electrons</span> in the ultracold <span class="hlt">plasma</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://arxiv.org/pdf/1501.01404.pdf','EPRINT'); return false;" href="http://arxiv.org/pdf/1501.01404.pdf"><span id="translatedtitle">Mechanisms of <span class="hlt">plasma</span> disruption and runaway <span class="hlt">electron</span> losses in tokamaks</span></a></p> <p><a target="_blank" href="http://www.osti.gov/eprints/">E-print Network</a></p> <p>Abdullaev, S S; Wongrach, K; Tokar, M; Koslowski, H R; Willi, O; Zeng, L</p> <p>2015-01-01</p> <p>Based on the analysis of data from the numerous dedicated experiments on <span class="hlt">plasma</span> disruptions in the TEXTOR tokamak mechanisms of the formation of runaway <span class="hlt">electron</span> beams and their losses are proposed. The <span class="hlt">plasma</span> disruption is caused by strong stochastic magnetic field formed due to nonlinearly excited low-mode number MHD modes. It is hypothesized that the runaway <span class="hlt">electron</span> beam is formed in the central <span class="hlt">plasma</span> region confined inside the intact magnetic surface located between $q=1$ and the closest low--order rational [$q=4/3$ or $q=3/2$] magnetic surfaces. The thermal quench time caused by the fast <span class="hlt">electron</span> transport in a stochastic magnetic field is calculated using the collisional transport model. The current decay stage is due to the ambipolar particle transport in a stochastic magnetic field. The runaway <span class="hlt">electron</span> beam in the confined <span class="hlt">plasma</span> region is formed due to their acceleration the inductive toroidal electric field. The runaway <span class="hlt">electron</span> beam current is modeled as a sum of toroidally symmetric part and a ...</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 id="translatedtitle">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('http://hdl.handle.net/2060/19770010909','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19770010909"><span id="translatedtitle"><span class="hlt">Electron</span> dynamics in a <span class="hlt">plasma</span> focus. [<span class="hlt">electron</span> acceleration</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Hohl, F.; Gary, S. P.; Winters, P. A.</p> <p>1977-01-01</p> <p>Results are presented of a numerical integration of the three-dimensional relativistic equations of motion of <span class="hlt">electrons</span> subject to given electric and magnetic fields deduced from experiments. Fields due to two different models are investigated. For the first model, the fields are those due to a circular distribution of axial current filaments. As the current filaments collapse toward the axis, large azimuthal magnetic and axial electric fields are induced. These fields effectively heat the <span class="hlt">electrons</span> to a temperature of approximately 8 keV and accelerate <span class="hlt">electrons</span> within the radius of the filaments to high axial velocities. Similar results are obtained for the current-reduction phase of focus formation. For the second model, the fields are those due to a uniform current distribution. Both the current-reduction and the compression phases were studied. These is little heating or acceleration of <span class="hlt">electrons</span> during the compression phase because the <span class="hlt">electrons</span> are tied to the magnetic field. However, during the current-reduction phase, <span class="hlt">electrons</span> near the axis are accelerated toward the center electrode and reach energies of 100 keV. A criterion is obtained which limits the runaway <span class="hlt">electron</span> current to about 400 A.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015JGRA..120.6427Y','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015JGRA..120.6427Y"><span id="translatedtitle">Formation and evolution of high-<span class="hlt">plasma</span>-pressure region in the near-Earth <span class="hlt">plasma</span> <span class="hlt">sheet</span>: Precursor and postcursor of substorm expansion onset</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Yao, Y.; Ebihara, Y.; Tanaka, T.</p> <p>2015-08-01</p> <p>Cause of substorm expansion onset is one of the major problems in the magnetospheric study. On the basis of a global magnetohydrodynamic (MHD) simulation, Tanaka et al. (2010) suggested that formation and evolution of a high-pressure region (HPR) in the near-Earth <span class="hlt">plasma</span> <span class="hlt">sheet</span> could result in sudden intensification of the Region 1 field-aligned current and the westward auroral electrojet. In this sense, the formation and evolution of the HPR are a key in understanding the cause of the onset. On 5 April 2009, three probes of the Time History of Events and Macroscale Interactions during Substorms (THEMIS) were located at XGSM~-11 Re around the equator, which provide unique opportunity to investigate the spatial-temporal evolution of the HPR near the substorm expansion onset. Just before the onset, a positive excursion of the <span class="hlt">plasma</span> pressure appeared at the outermost probe first, followed by the inner ones. Just after the onset, the opposite sequence took place. A positive excursion of the Y component of the current density was observed near the onset by the THEMIS probes and followed by a decrease trend. A similar variation was also found in the MHD simulation. All these features are consistent with the simulation result that a squeeze of the <span class="hlt">plasma</span> from the <span class="hlt">plasma</span> <span class="hlt">sheet</span> results in the formation of the HPR before the onset and that the accumulated <span class="hlt">plasma</span> spreads outward after the onset. The HPR is shown to be important for the dynamics of the magnetosphere during a substorm.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014PlST...16..995Z','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014PlST...16..995Z"><span id="translatedtitle"><span class="hlt">Electron</span> Acoustic Solitary Waves in Magnetized Quantum <span class="hlt">Plasma</span> with Relativistic Degenerated <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>Zhu, Zhenni; Wu, Zhengwei; Li, Chunhua; Yang, Weihong</p> <p>2014-11-01</p> <p>A model for the nonlinear properties of obliquely propagating <span class="hlt">electron</span> acoustic solitary waves in a two-<span class="hlt">electron</span> populated relativistically quantum magnetized <span class="hlt">plasma</span> is presented. By using the standard reductive perturbation technique, the Zakharov-Kuznetsov (ZK) equation is derived and this equation gives the solitary wave solution. It is observed that the relativistic effects, the ratio of the cold to hot <span class="hlt">electron</span> unperturbed number density and the magnetic field normalized by <span class="hlt">electron</span> cyclotron frequency significantly influence the solitary structures.</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('http://ntrs.nasa.gov/search.jsp?R=19830052978&hterms=electron+beam+atmosphere&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3Delectron%2Bbeam%2Batmosphere','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19830052978&hterms=electron+beam+atmosphere&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3Delectron%2Bbeam%2Batmosphere"><span id="translatedtitle"><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://www.osti.gov/scitech/biblio/21347213','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/21347213"><span id="translatedtitle">Continuous gas discharge <span class="hlt">plasma</span> with 200 K <span class="hlt">electron</span> temperature</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Dickson, Shannon; Robertson, Scott</p> <p>2010-03-15</p> <p>A very cold and collisional hot-filament discharge <span class="hlt">plasma</span> is created in a vacuum chamber with an inner wall cooled by liquid nitrogen. The inner chamber (16.5 cm diameterx30 cm) has two negatively biased tungsten filaments for <span class="hlt">plasma</span> generation and a Langmuir probe on axis for diagnostic measurements. With the wall at 140 K, 0.5-16 mA filament emission, and 1.6 mTorr carbon monoxide as the working gas, probe data give <span class="hlt">electron</span> temperatures of 17-28 meV (197-325 K) with corresponding densities of 10{sup 8}-10{sup 9} cm{sup -3}. With He, Ar, H{sub 2}, and N{sub 2} at 140 K, the <span class="hlt">electron</span> temperatures are >500 K. The lower <span class="hlt">electron</span> temperature with CO is attributed to the asymmetric CO molecule having a larger cross section for <span class="hlt">electron</span> excitation of rotational modes as a consequence of its dipole moment.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010JGRA..115.8205C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010JGRA..115.8205C"><span id="translatedtitle">Geomagnetic signatures of current wedge produced by fast flows in a <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, Jin-Bin; Yan, Chunxiao; Dunlop, Malcolm; Reme, Henri; Dandouras, Iannis; Zhang, Tielong; Yang, Dongmei; Moiseyev, Alexey; Solovyev, Stepan I.; Wang, Z. Q.; Leonoviche, A.; Zolotukhina, N.; Mishin, V.</p> <p>2010-08-01</p> <p>This paper uses the <span class="hlt">plasma</span> data from Cluster and TC-1 and geomagnetic data to study the geomagnetic signatures of the current wedge produced by fast-flow braking in the <span class="hlt">plasma</span> <span class="hlt">sheet</span>. The three fast flows studied here occurred in a very quiet background and were accompanied by no (or weak) particle injections, thus avoiding the influences from other disturbances. All the geomagnetic signatures of a substorm current wedge can be found in the geomagnetic signatures of a current system produced by the braking of fast flows, indicating that the fast flows can produce a complete current wedge which contains postmidnight downward and premidnight upward field-aligned currents, as well as a westward electrojet. The Pi2 precursors exist not only at high latitudes but also at midlatitudes. The starting times of midlatitude Pi2 precursors can be identified more precisely than those of high-latitude Pi2 precursors, providing a possible method to determine the starting time of fast flows in their source regions. The AL drop that a bursty bulk flow produces is proportional to its velocity and duration. In three cases, the AL drops are <100 nT. Because the AE increase of a typical substorm is >200 nT, whether a substorm can be triggered depends mainly on the conditions of the braking regions before fast flows. The observations of solar wind before the three fast flows suggest that it is difficult for the fast flows to trigger a substorm when the interplanetary magnetic field Bz of solar wind is weakly southward.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=20060009303&hterms=electric+current&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3D%2528electric%2Bcurrent%2529','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=20060009303&hterms=electric+current&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3D%2528electric%2Bcurrent%2529"><span id="translatedtitle">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/2015PSST...24b5032B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015PSST...24b5032B"><span id="translatedtitle">Measuring the <span class="hlt">electron</span> density, temperature, and electronegativity in <span class="hlt">electron</span> beam-generated <span class="hlt">plasmas</span> produced in argon/SF6 mixtures</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Boris, D. R.; Fernsler, R. F.; Walton, S. G.</p> <p>2015-04-01</p> <p>This paper presents measurements of <span class="hlt">electron</span> density (ne0), <span class="hlt">electron</span> temperature (Te), and electronegativity (?) in <span class="hlt">electron</span> beam-generated <span class="hlt">plasmas</span> produced in mixtures of argon and SF6 using Langmuir probes and <span class="hlt">plasma</span> resonance spectroscopy. Langmuir probe measurements are analyzed using a model capable of handling multi-component <span class="hlt">plasmas</span> with both positive and negative ions. Verification of the model is provided through <span class="hlt">plasma</span> frequency resonance measurements of ne0. The results suggest a simple approach to ascertaining ? in negative-ion-containing <span class="hlt">plasmas</span> using Langmuir probes alone. In addition, modest amounts of SF6 are shown to produce sharp increases in both Te and ? in <span class="hlt">electron</span> beam generated <span class="hlt">plasmas</span>.</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 id="translatedtitle">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/2015PhPl...22b2902B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015PhPl...22b2902B"><span id="translatedtitle">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://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Berezhiani, V. I.; Shatashvili, N. L.; Mahajan, S. M.</p> <p>2015-02-01</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://arxiv.org/pdf/1412.6656.pdf','EPRINT'); return false;" href="http://arxiv.org/pdf/1412.6656.pdf"><span id="translatedtitle">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/eprints/">E-print Network</a></p> <p>Berezhiani, V I; Mahajan, S M</p> <p>2014-01-01</p> <p>A new class of Double Beltrami-Bernoulli equilibria, sustained by <span class="hlt">electron</span> degeneracy pressure, are 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://hdl.handle.net/2060/19870010644','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19870010644"><span id="translatedtitle"><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('http://adsabs.harvard.edu/abs/2012JGRA..117.3211T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012JGRA..117.3211T"><span id="translatedtitle">Dynamics of long-period ULF waves in the <span class="hlt">plasma</span> <span class="hlt">sheet</span>: Coordinated space and ground observations</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Tian, A. M.; Zong, Q. G.; Zhang, T. L.; Nakamura, R.; Du, A. M.; Baumjohann, W.; Glassmeier, K. H.; Volwerk, M.; Hartinger, M.; Wang, Y. F.; Du, J.; Yang, B.; Zhang, X. Y.; Panov, E.</p> <p>2012-03-01</p> <p>Spacecraft and ground-based observations are used to study characteristics of ultralow frequency waves in the <span class="hlt">plasma</span> <span class="hlt">sheet</span> from the postmidnight to morning local time sectors in the terrestrial magnetosphere. Field line resonance (FLR) type oscillations with discrete and latitude-dependent frequencies in the ranges of 1.7-2.0 and 3.0-3.2 mHz are observed in situ by the Time History of Events and Macroscale Interactions during Substorms C (THEMIS C), THEMIS D, THEMIS E, and GOES 12 spacecraft. The ground resonant oscillations in the two mentioned frequency bands are also observed at corresponding spacecraft footprints. Spectral peaks at these frequencies are observed by nearly all ground stations from premidnight to noon, with the larger-amplitude oscillations occurring in a narrow range of latitudes (3°-6°). The largest wave activity occurred in the magnetic local time of ˜05:00. The ground observations indicate westward propagation for the 1.8 mHz wave activity with an azimuthal wave number of about -2.6. The Poynting vectors from the THEMIS spacecraft show weak net energy flow (antifield aligned) toward the ionosphere of the southern hemisphere. They also show notable net energy flow toward the west. A possible interpretation is that the observed FLRs are driven by cavity and waveguide modes in the nightside outer magnetosphere after a period of long-lasting northward interplanetary magnetic field.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012SoPh..281..423S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012SoPh..281..423S"><span id="translatedtitle">The Heliospheric <span class="hlt">Plasma</span> <span class="hlt">Sheet</span> Observed in situ by Three Spacecraft over Four Solar Rotations</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Simunac, K. D. C.; Galvin, A. B.; Farrugia, C. J.; Kistler, L. M.; Kucharek, H.; Lavraud, B.; Liu, Y. C.-M.; Luhmann, J. G.; Ogilvie, K. W.; Opitz, A.; Popecki, M. A.; Sauvaud, J.-A.; Wang, S.</p> <p>2012-11-01</p> <p>In this paper we present in situ observations of the heliospheric <span class="hlt">plasma</span> <span class="hlt">sheet</span> (HPS) from STEREO-A, Wind, and STEREO-B over four solar rotations in the declining phase of Solar Cycle 23, covering late March through late June 2007. During this time period the three spacecraft were located in the ecliptic plane, and were gradually separating in heliographic longitude from about 3 degrees to 14 degrees. Crossings of the HPS were identified using the following criteria: reversal of the interplanetary magnetic field sector, enhanced proton density, and local minima in both the proton specific entropy argument and in the alpha particle-to-proton number density ratio ( N a/ N p). Two interplanetary coronal mass ejections (ICMEs) were observed during the third solar rotation of our study period, which disrupted the HPS from its quasi-stationary state. We find differences in the in situ proton parameters at the HPS between the three spacecraft despite temporal separations of less than one day. We attribute these differences to both small separations in heliographic latitude and radial evolution of the solar wind leading to the development of compression regions associated with stream interaction regions (SIRs). We also observed a modest enhancement in the density of iron ions at the HPS.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2007JaJAP..46.6051W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2007JaJAP..46.6051W"><span id="translatedtitle">Numerical Study of Instabilities Induced by <span class="hlt">Sheet</span> <span class="hlt">Electron</span> Beam on Corrugated Metal Plate</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Watanabe, Osamu; Watanabe, Tsuguhiro; Ogura, Kazuo; Tatematsu, Yoshinori; Shima, Yoriko; Imai, Tsuyoshi</p> <p>2007-09-01</p> <p>It has been confirmed that the normal mode of a surface wave on a corrugated metal plate can be excited by a <span class="hlt">sheet</span> <span class="hlt">electron</span> beam. Two types of instabilities are analyzed numerically. One is the Cherenkov instability between the surface normal mode and the slow-space-charge mode of the <span class="hlt">electron</span> beam. This instability is possibly absolute instability. The oscillation frequency of this instability can be controlled by the amplitude of the corrugation depth. The <span class="hlt">electron</span> beam energy for this instability is determined by the ratio of the period length and the amplitude of the corrugation. Another is the Smith-Purcell-type instability. This instability is always convective-type instability. The oscillation frequency is higher than that of the above-mentioned Cherenkov instability and is in a broad band. The temporal growth rate of this instability is strongly reduced as the beam energy is reduced.</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 id="translatedtitle">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('http://www.osti.gov/scitech/biblio/21255213','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/21255213"><span id="translatedtitle">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('http://adsabs.harvard.edu/abs/2004APS..DPPFP1123B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2004APS..DPPFP1123B"><span id="translatedtitle">New <span class="hlt">Electron</span> Temperature Diagnostic for Low Temperature <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>Boivin, Robert; Loch, Stuart</p> <p>2004-11-01</p> <p>A new line ratio diagnostic design to measure <span class="hlt">electron</span> temperature in <span class="hlt">plasma</span> is presented. Unlike previous diagnostics, this new technique features emission lines originating from levels with different principal quantum numbers. A significant advantage of this approach is that the line ratio varies considerably with temperature in the 1 to 20 eV range. Another advantage is that both transitions are optically thin even for <span class="hlt">plasma</span> density up to 1 E 14 cm-3. The drawbacks are: a large difference in the line intensities and the significant difference in wavelength. The event of high sensitivity CCD camera combine with precise calibration can to a large extent minimize these latest two issues. The diagnostic is tested on the ASTRAL (Auburn Steady sTate Research fAciLity) helicon <span class="hlt">plasma</span> source. ASTRAL is a 2.3 m long helicon source designed to investigate basic <span class="hlt">plasma</span> and space <span class="hlt">plasma</span> processes. The device produces <span class="hlt">plasmas</span> with the following typical parameters ne = 1 E9 to 1 E13 cm-3, Te = 2 to 20 eV and Ti = 0.03 to 0.3 eV. A series of 8 large coils produce an axial magnetic field up to 1.2 kGauss. Operating pressure varies from 0.1 to 100 mTorr. A water cooled fractional helix antenna is used to introduce RF power up to 2 kwatt through a standard matching circuit. The line ratio temperatures are measured by means of a 0.33 m McPherson Criss-Cross Scanning monochromator instrumented with a SPH5 Apogee CCD camera. The line ratio temperatures are compared to <span class="hlt">electron</span> temperatures measured by a rf compensated Langmuir Probe. To validate the diagnostic, a new collisional radiative model that makes use of the latest excitation cross-section values is presented. The model is also used to predict the potential range of this new diagnostic both in terms of <span class="hlt">electron</span> temperature and <span class="hlt">plasma</span> density.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4557361','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4557361"><span id="translatedtitle">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://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Rumbach, Paul; Bartels, David M.; Sankaran, R. Mohan; Go, David B.</p> <p>2015-01-01</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. PMID:26088017</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2009JIMTW..30..670S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009JIMTW..30..670S"><span id="translatedtitle">Design of <span class="hlt">Sheet</span>-Beam <span class="hlt">Electron</span> Gun with Planar Cathode for Terahertz Devices</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Srivastava, Anurag; So, Jin-Kyu; Wang, Yiman; Wang, Jinshu; Raju, R. S.; Han, Seong-Tae; Park, Gun-Sik</p> <p>2009-07-01</p> <p>The design of a <span class="hlt">sheet</span>-beam <span class="hlt">electron</span> gun with planar cathode was made with the help of a three-dimensional electrostatic field solver that was capable of forming a <span class="hlt">sheet</span>-beam of 19 mA at 12 kV. It uses one-dimensional three-fold beam cross-sectional area compression meets the specific requirement of a beam to be formed of height 30 µm and width 600 µm at the beam-waist position with over 100 A/cm2 uniform current density and 0.068 ?-mm-mrad emittance, typically, for 0.5 THz devices. A novel beam focusing electrode (BFE) provided with extended-corner rectangular-aperture geometry alleviating the commonly encountered <span class="hlt">sheet</span>-beam formation problem with a gun that uses a conventional BFE, as well as it reduced beam emittance more than 50%. The practicability of the design was tested by the high-voltage, the thermal and structural analyses. Work has been initiated to test the performance of special high current scandate cathode using anode-aperture mapping.</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 id="translatedtitle">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('http://ntrs.nasa.gov/search.jsp?R=19930062681&hterms=CNRS&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3DCNRS','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19930062681&hterms=CNRS&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3DCNRS"><span id="translatedtitle">Determining <span class="hlt">electron</span> temperature and density in a hydrogen microwave <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>Scott, Carl D.; Farhat, Samir; Gicquel, Alix; Hassouni, Khaled; Lefebvre, Michel</p> <p>1993-01-01</p> <p>A three-temperature thermo-chemical model is developed for analyzing the chemical composition and energy states of a hydrogen microwave <span class="hlt">plasma</span> used for studying diamond deposition. The chemical and energy exchange rate coefficients are determined from cross section data, assuming Maxwellian velocity distributions for <span class="hlt">electrons</span>. The model is reduced to a zero-dimensional problem to solve for the <span class="hlt">electron</span> temperature and ion mole fraction, using measured vibrational and rotational temperatures. The calculations indicate that the <span class="hlt">electron</span> temperature may be determined to within a few percent error even though the uncertainty in dissociation fraction is many times larger.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013APS..GECHW1075S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013APS..GECHW1075S"><span id="translatedtitle"><span class="hlt">Electron</span> energy balance analysis of ccrf discharge <span class="hlt">plasmas</span> in oxygen</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Sheykin, Igor; Becker, Markus M.; Loffhagen, Detlef</p> <p>2013-09-01</p> <p>In capacitively coupled radio frequency (ccrf) oxygen <span class="hlt">plasmas</span> at low pressure the mean <span class="hlt">electron</span> energy is assumed to be a measure for etching, deposition and other surface processes. Hence, it is important to know its spatio-temporal distribution, dependence on applied voltage and discharge parameters. Here, an axially and phase resolved analysis of the mean <span class="hlt">electron</span> energy has been performed by means of fluid modelling for discharge <span class="hlt">plasmas</span> in a reactor with plane parallel electrodes. The model includes the coupled system of balance equations for heavy species, the <span class="hlt">electron</span> component and the mean <span class="hlt">electron</span> energy as well as Poisson's equation with the corresponding boundary conditions. The analysis has been done for pressures between 30 and 50 Pa, applied voltage amplitudes from 100 to 500 V and a frequency of 13 . 56 MHz. The impact of the different contributions to the <span class="hlt">electron</span> energy balance is discussed. In particular, it was found that the ratio between energy gain due to Joule heating and energy flux in the <span class="hlt">plasma</span> bulk depends strongly on the applied voltage and pressure of the gas. The work has been supported by DFG with SFB-TRR 24.</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/2015JPhCS.652a2067V','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015JPhCS.652a2067V"><span id="translatedtitle"><span class="hlt">Electron</span> source with a multi-apertured <span class="hlt">plasma</span> emitter</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Vorobyov, M. S.; Koval, N. N.; Sulakshin, S. A.</p> <p>2015-11-01</p> <p>In the present study, we investigated the energy efficiency of an <span class="hlt">electron</span> source with a multi-aperture <span class="hlt">plasma</span> emitter where the generated beam is extracted into the atmosphere through a thin metal foil. The boundary of the <span class="hlt">plasma</span> produced in this type of emitter is stabilized with a fine metal grid. To prevent the loss of <span class="hlt">electrons</span> at the circle-holed support grid of the extraction foil window, a metal mask with holes of smaller diameter arranged coaxially to the support grid holes is put on the emission grid. Thus, the <span class="hlt">electron</span> beam is a superposition of beamlets formed by individual <span class="hlt">electron</span> emitting units with the <span class="hlt">plasma</span> boundary stabilized by the fine metal grid. The efficiency of current extraction from the acceleration gap into the atmosphere reached 75% with respect to the gap current, making possible to increase the average power of the extracted <span class="hlt">electron</span> beam. With a 200 -kV accelerating voltage, a 16-A current in the acceleration gap, and 40 ?s FWHM pulse duration, 4 kW of the average beam power was extracted into the atmosphere from the acceleration gap. With the geometric transparency of the support grid of the extraction foil window equal to 56%, this made 65% of the beam power in the gap. Further increasing the beam power was limited by the power of the high-voltage power supply.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/776651','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/776651"><span id="translatedtitle">Betatron radiation from <span class="hlt">electron</span> beams in <span class="hlt">plasma</span> focusing channels</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Esarey, E.; Catravas, P.; Leemans, W.P.</p> <p>2000-06-01</p> <p>Spontaneous radiation emitted from an <span class="hlt">electron</span> undergoing betatron motion is a <span class="hlt">plasma</span> focusing channel is analyzed and applications to <span class="hlt">plasma</span> wakefield accelerator experiments and to the ion channel laser (ICL) are discussed. Important similarities and differences between a free <span class="hlt">electron</span> laser (FEL) and in an ICL are delineated. It is shown that the frequency of spontaneous radiation is a strong function of the betatron strength parameter a{sub {beta}}, which plays a similar role to that of the wiggler strength parameter in a conventional FEL. For a{sub {beta}} {approx_gt} 1, radiation is emitted in numerous harmonics. Furthermore, a{sub {beta}} is proportional to the amplitude of the betatron orbit, which varies for every <span class="hlt">electron</span> in the beam. This places serious limits on the possibility of realizing an ICL.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/22299706','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/22299706"><span id="translatedtitle"><span class="hlt">Electron</span> energy spectrum in circularly polarized laser irradiated overdense <span class="hlt">plasma</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Liu, C. S.; Tripathi, V. K.; Shao, Xi; Kumar, Pawan</p> <p>2014-10-15</p> <p>A circularly polarized laser normally impinged on an overdense <span class="hlt">plasma</span> thin foil target is shown to accelerate the <span class="hlt">electrons</span> in the skin layer towards the rear, converting the quiver energy into streaming energy exactly if one ignores the space charge field. The energy distribution of <span class="hlt">electrons</span> is close to Maxwellian with an upper cutoff ?{sub max}=mc{sup 2}[(1+a{sub 0}{sup 2}){sup 1/2}?1], where a{sub 0}{sup 2}=(1+(2?{sup 2}/?{sub p}{sup 2})|a{sub in}|{sup 2}){sup 2}?1, |a{sub in}| is the normalized amplitude of the incident laser of frequency ?, and ?{sub p} is the <span class="hlt">plasma</span> frequency. The energetic <span class="hlt">electrons</span> create an electrostatic sheath at the rear and cause target normal sheath acceleration of protons. The energy gain by the accelerated ions is of the order of ?{sub max}.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.unl.edu/diocles/PhysPlasmas_18_056704.pdf','EPRINT'); return false;" href="http://www.unl.edu/diocles/PhysPlasmas_18_056704.pdf"><span id="translatedtitle"><span class="hlt">Electron</span> self-injection into an evolving <span class="hlt">plasma</span> bubble: Quasi-monoenergetic laser-<span class="hlt">plasma</span> acceleration in the blowout regimea)</span></a></p> <p><a target="_blank" href="http://www.osti.gov/eprints/">E-print Network</a></p> <p>Umstadter, Donald</p> <p></p> <p><span class="hlt">Electron</span> self-injection into an evolving <span class="hlt">plasma</span> bubble: Quasi-monoenergetic laser (Received 26 November 2010; accepted 27 January 2011; published online 12 April 2011) An <span class="hlt">electron</span> density quiescent <span class="hlt">plasma</span> <span class="hlt">electrons</span>, whereas stabilization and contraction terminate self-injection thus limiting</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=20020043373&hterms=measure+density&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3Dmeasure%2Bdensity','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=20020043373&hterms=measure+density&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3Dmeasure%2Bdensity"><span id="translatedtitle"><span class="hlt">Electron</span> Densities Near Io from Galileo <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>Gurnett, D. A.; Persoon, A. M.; Kurth, W. S.; Roux, A.; Bolton, S. J.</p> <p>2001-01-01</p> <p>This paper presents an overview of <span class="hlt">electron</span> densities obtained near Io from the Galileo <span class="hlt">plasma</span> wave instrument during the first four flybys of Io. These flybys were Io, which was a downstream wake pass that occurred on December 7, 1995; I24, which was an upstream pass that occurred on October 11, 1999; I25, which was a south polar pass that occurred on November 26, 1999; and I27, which was an upstream pass that occurred on February 22, 2000. Two methods were used to measure the <span class="hlt">electron</span> density. The first was based on the frequency of upper hybrid resonance emissions, and the second was based on the low-frequency cutoff of electromagnetic radiation at the <span class="hlt">electron</span> <span class="hlt">plasma</span> frequency. For three of the flybys, Io, I25, and I27, large density enhancements were observed near the closest approach to Io. The peak <span class="hlt">electron</span> densities ranged from 2.1 to 6.8 x 10(exp 4) per cubic centimeters. These densities are consistent with previous radio occultation measurements of Io's ionosphere. No density enhancement was observed during the I24 flyby, most likely because the spacecraft trajectory passed too far upstream to penetrate Io's ionosphere. During two of the flybys, I25 and I27, abrupt step-like changes were observed at the outer boundaries of the region of enhanced <span class="hlt">electron</span> density. Comparisons with magnetic field models and energetic particle measurements show that the abrupt density steps occur as the spacecraft penetrated the boundary of the Io flux tube, with the region of high <span class="hlt">plasma</span> density on the inside of the flux tube. Most likely the enhanced <span class="hlt">electron</span> density within the Io flux tube is associated with magnetic field lines that are frozen to Io by the high conductivity of Io's atmosphere, thereby enhancing the escape of <span class="hlt">plasma</span> along the magnetic field lines that pass through Io's ionosphere.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1996Ap%26SS.239..125V','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1996Ap%26SS.239..125V"><span id="translatedtitle">Electrostatic Solitons in Multispecies <span class="hlt">Electron</span>-Positron <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>Verheest, F.; Hellberg, M. A.; Gray, G. J.; Mace, R. L.</p> <p>1996-05-01</p> <p>Acoustic solitons are investigated in <span class="hlt">electron</span>-positron <span class="hlt">plasmas</span> containing equal hot and cool components of both species. The hot components are isothermal Boltzmann distributed, the cool constituents are modelled by adiabatic fluids. The equations are integrated exactly in terms of a Sagdeev potential. Solitons are shown to be possible, but no double layers, due to the symmetry in the model. Bearing in mind the constraints imposed by the Boltzmann assumption, small amplitude solitons only are found. Such findings are relevant for different kinds of astrophysical <span class="hlt">plasmas</span>, as well as for other types of similar acoustic solitons.</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 id="translatedtitle">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 relative importance of the avalanche mechanism is investigated as a function of the key parameters for runaway <span class="hlt">electron</span> formation, namely the <span class="hlt">plasma</span> temperature and the electric field strength. In agreement with theoretical predictions, the LUKE simulations show that in low temperature and electric field the knock-on collisions becomes the dominant source of runaway <span class="hlt">electrons</span> and can play a significant role for runaway <span class="hlt">electron</span> generation, including in non-disruptive tokamak scenarios.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012JPhCS.365a2048V','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012JPhCS.365a2048V"><span id="translatedtitle">Investigation of <span class="hlt">electron</span> beam parameters inside the drift region of <span class="hlt">plasma</span> cathode <span class="hlt">electron</span> gun</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Verma, Deepak K.; Pal, U. N.; Kumar, N.; Prajapati, J.; Kumar, M.; Prakash, Ram; Srivastava, V.</p> <p>2012-05-01</p> <p>This paper presents experimental studies for the production and propagation of an <span class="hlt">electron</span> beam from a single gap pseudospark discharge based <span class="hlt">plasma</span> cathode <span class="hlt">electron</span> (PCE) gun. The generated <span class="hlt">electron</span> beam has been successfully propagated for more than 25 cm in a gaseous environment without application of external guiding magnetic field at different operating conditions. The <span class="hlt">electron</span> beam losses due to recombination with ions and collision with walls of drift space have been estimated. The <span class="hlt">electron</span> beam profile has also been analyzed in the drift region of the gun.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015PhPl...22f2307M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015PhPl...22f2307M"><span id="translatedtitle">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://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Mbuli, L. N.; Maharaj, S. K.; Bharuthram, R.; Singh, S. V.; Lakhina, G. S.</p> <p>2015-06-01</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('http://adsabs.harvard.edu/abs/2006NIMPA.566..662C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2006NIMPA.566..662C"><span id="translatedtitle"><span class="hlt">Electron</span> emission and <span class="hlt">plasma</span> generation in a modulator <span class="hlt">electron</span> gun using ferroelectric cathode</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Chen, Shutao; Zheng, Shuxin; Zhu, Ziqiu; Dong, Xianlin; Tang, Chuanxiang</p> <p>2006-10-01</p> <p>Strong <span class="hlt">electron</span> emission and dense <span class="hlt">plasma</span> generation have been observed in a modulator <span class="hlt">electron</span> gun with a Ba 0.67Sr 0.33TiO 3 ferroelectric cathode. Parameter of the modulator <span class="hlt">electron</span> gun and lifetime of the ferroelectric cathode were investigated. It was shown that <span class="hlt">electron</span> emission from Ba 0.67Sr 0.33TiO 3 cathode with a positive triggering pulse is a sort of <span class="hlt">plasma</span> emission. <span class="hlt">Electrons</span> were emitted by the co-effect of surface <span class="hlt">plasma</span> and non-compensated negative polarization charges at the surface of the ferroelectric. The element analyses of the graphite collector after emission process was performed to show the ingredient of the <span class="hlt">plasma</span> consist of Ba, Ti and Cu heavy cations of the ceramic compound and electrode. It was demonstrated the validity of the Child-Langmuir law by introducing the decrease of vacuum gap and increase of emission area caused by the expansion of the surface <span class="hlt">plasma</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014AGUFMSM23C4254Y','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014AGUFMSM23C4254Y"><span id="translatedtitle">Sudden Pressure Enhancement and Tailward Retreat in the Near-Earth <span class="hlt">Plasma</span> <span class="hlt">Sheet</span>: THEMIS Observation and MHD Simulation</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Yao, Y.; Ebihara, Y.; Tanaka, T.</p> <p>2014-12-01</p> <p>Sudden enhancement of the <span class="hlt">plasma</span> pressure in the near-Earth <span class="hlt">plasma</span> <span class="hlt">sheet</span> is one of the common manifestations of the substorms, and is thought to play an important role in relevant disturbances in the magnetosphere and ionosphere. On 1 March 2008 four of the THEMIS (Time History of Events and Macroscale Interactions during Substorms) probes observed the sudden enhancement of the <span class="hlt">plasma</span> pressure around 15:40 UT. The four probes were almost aligned along the Sun-Earth line, which was suitable for investigating spatial-temporal evolution of the near-Earth <span class="hlt">plasma</span> <span class="hlt">sheet</span> around the substorm onset. The four probes were located off the equatorial plane, according to a magnetic field model. The <span class="hlt">plasma</span> pressure suddenly increased at the inner most probe first (at ~7.2 Re), followed by the outer probes (at ~7.5, ~8.3, and ~10.4 Re), that could be seen as a tailward propagation (or retreat) of high-pressure region (HPR). After comparing with results of a global magnetohydrodynamics (MHD) simulation, we found that only the tailward propagation of the HPR could be seen at off-equator. Near the equatorial plane, the HPR propagates earthward from the magnetotail region, then it retreats tailward. In the course of the tailward propagation, the HPR also propagates away from the equatorial plane. As a consequence, the inner most probe observed the pressure enhancement first, followed by the outer probes. The propagation of the HPR in the ZGSM direction is understood to be a combination of the convergence of the <span class="hlt">plasma</span> flow (the divergence of bulk velocity along the ZGSM axis), and the pressure gradient force.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015JGRA..120..201Y','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015JGRA..120..201Y"><span id="translatedtitle">Sudden pressure enhancement and tailward retreat in the near-Earth <span class="hlt">plasma</span> <span class="hlt">sheet</span>: THEMIS observation and MHD simulation</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Yao, Y.; Ebihara, Y.; Tanaka, T.</p> <p>2015-01-01</p> <p>enhancement of the <span class="hlt">plasma</span> pressure in the near-Earth <span class="hlt">plasma</span> <span class="hlt">sheet</span> is one of the common manifestations of substorms and is thought to play an important role in relevant disturbances in the magnetosphere and ionosphere. On 1 March 2008, four of the Time History of Events and Macroscale Interactions during Substorms probes observed the sudden enhancement of the <span class="hlt">plasma</span> pressure around 15:40 UT. The four probes were almost aligned along the Sun-Earth line, which was suitable for investigating spatial-temporal evolution of the near-Earth <span class="hlt">plasma</span> <span class="hlt">sheet</span> around the substorm onset. The four probes were located off the equatorial plane, according to a magnetic field model. The <span class="hlt">plasma</span> pressure suddenly increased at the innermost probe first (at ~7.2 Re), followed by the outer probes (at ~7.5, ~8.3, and ~10.4 Re), that could be seen as a tailward propagation (or retreat) of high-pressure region (HPR). After comparing with results of a global magnetohydrodynamic simulation, we found that only the tailward propagation of the HPR could be seen at off equator. Near the equatorial plane, the HPR propagates earthward from the magnetotail region, then it retreats tailward. In the course of the tailward retreat, the HPR also propagates away from the equatorial plane. As a consequence, the innermost probe observed the pressure enhancement first, followed by the outer probes. The propagation of the HPR in the ZGSM direction is understood to be a combination of the convergence of the <span class="hlt">plasma</span> flow (the divergence of bulk velocity along the ZGSM axis) and the pressure gradient force.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19970040338&hterms=cold+plasma&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3Dcold%2Bplasma','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19970040338&hterms=cold+plasma&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3Dcold%2Bplasma"><span id="translatedtitle">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('http://adsabs.harvard.edu/abs/2014JGRA..119.7199L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014JGRA..119.7199L"><span id="translatedtitle">Classification of fast flows in central <span class="hlt">plasma</span> <span class="hlt">sheet</span>: Superposed epoch analysis based on THEMIS observations</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Li, H.; Wang, C.; Fu, S. Y.</p> <p>2014-09-01</p> <p>A statistical survey of 560 fast flows in midnight central <span class="hlt">plasma</span> <span class="hlt">sheet</span> is performed based on Time History of Events and Macroscale Interactions during Substorms (THEMIS) observations during its first two tail phases. From superposed epoch analysis, no significant substorm activities are found to be associated with the occurrence of fast flows beyond X=-15 Re. Considering the associations with substorm activities, the fast flows inside of X=-15 Re can be classified into two obvious classes: short duration (< 2.0 min) and long duration (> 4.0 min). Substorm breakups are shown to be more closely correlated to short-duration fast flows. Furthermore, the onset of short-duration fast flows in the dipolarization region (X=-9 to -11 Re) is almost simultaneous with the onset of substorm breakups and dipolarizations. On the other hand, time delays of 2-4 min are both found in the near-Earth region (X=-7 to -9 Re) and in the near-tail region (X=-11 to -15 Re). Assuming that short-duration fast flows are generated by the force imbalance caused by cross-tail current disruption, these features are consistent with the predictions made by the cowling electrojet current loop and the cross-tail current disruption substorm models. In comparison, although more magnetic flux is transported toward Earth for long-duration fast flows, no clear substorm breakup is closely associated with them. The analysis of 2-D ion velocity distribution further shows some differences. For short-duration fast flows, multiple crescent-shaped ion populations are found. However, for long-duration fast flows, there exists only a single crescent-shaped ion population. The difference may be an important signature for distinguishing these two classes of fast flows.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/12059723','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/12059723"><span id="translatedtitle">Synchrotron radiation from <span class="hlt">electron</span> beams in <span class="hlt">plasma</span>-focusing channels.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Esarey, E; Shadwick, B A; Catravas, P; Leemans, W P</p> <p>2002-05-01</p> <p>Spontaneous radiation emitted from relativistic <span class="hlt">electrons</span> undergoing betatron motion in a <span class="hlt">plasma</span>-focusing channel is analyzed, and applications to <span class="hlt">plasma</span> wake-field accelerator experiments and to the ion-channel laser (ICL) are discussed. Important similarities and differences between a free <span class="hlt">electron</span> laser (FEL) and an ICL are delineated. It is shown that the frequency of spontaneous radiation is a strong function of the betatron strength parameter a(beta), which plays a role similar to that of the wiggler strength parameter in a conventional FEL. For a(beta) > or approximately 1, radiation is emitted in numerous harmonics. Furthermore, a(beta) is proportional to the amplitude of the betatron orbit, which varies for every <span class="hlt">electron</span> in the beam. The radiation spectrum emitted from an <span class="hlt">electron</span> beam is calculated by averaging the single-<span class="hlt">electron</span> spectrum over the <span class="hlt">electron</span> distribution. This leads to a frequency broadening of the radiation spectrum, which places serious limits on the possibility of realizing an ICL. PMID:12059723</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/22403284','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/22403284"><span id="translatedtitle">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/1983JGR....8810123P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1983JGR....8810123P"><span id="translatedtitle">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://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Persoon, A. M.; Gurnett, D. A.; Shawhan, S. D.</p> <p>1983-12-01</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> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20110004225','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20110004225"><span id="translatedtitle">Non-ambipolar radio-frequency <span class="hlt">plasma</span> <span class="hlt">electron</span> source and systems and methods for generating <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>Hershkowitz, Noah (Inventor); Longmier, Benjamin (Inventor); Baalrud, Scott (Inventor)</p> <p>2011-01-01</p> <p>An <span class="hlt">electron</span> generating device extracts <span class="hlt">electrons</span>, through an <span class="hlt">electron</span> sheath, from <span class="hlt">plasma</span> produced using RF fields. The <span class="hlt">electron</span> sheath is located near a grounded ring at one end of a negatively biased conducting surface, which is normally a cylinder. Extracted <span class="hlt">electrons</span> pass through the grounded ring in the presence of a steady state axial magnetic field. Sufficiently large magnetic fields and/or RF power into the <span class="hlt">plasma</span> allow for helicon <span class="hlt">plasma</span> generation. The ion loss area is sufficiently large compared to the <span class="hlt">electron</span> loss area to allow for total non-ambipolar extraction of all <span class="hlt">electrons</span> leaving the <span class="hlt">plasma</span>. Voids in the negatively-biased conducting surface allow the time-varying magnetic fields provided by the antenna to inductively couple to the <span class="hlt">plasma</span> within the conducting surface. The conducting surface acts as a Faraday shield, which reduces any time-varying electric fields from entering the conductive surface, i.e. blocks capacitive coupling between the antenna and the <span class="hlt">plasma</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/doepatents/biblio/973142','DOE-PATENT-XML'); return false;" href="http://www.osti.gov/doepatents/biblio/973142"><span id="translatedtitle">Non-ambipolar radio-frequency <span class="hlt">plasma</span> <span class="hlt">electron</span> source and systems and methods for generating <span class="hlt">electron</span> beams</span></a></p> <p><a target="_blank" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Hershkowitz, Noah (Madison, WI); Longmier, Benjamin (Madison, WI); Baalrud, Scott (Madison, WI)</p> <p>2009-03-03</p> <p>An <span class="hlt">electron</span> generating device extracts <span class="hlt">electrons</span>, through an <span class="hlt">electron</span> sheath, from <span class="hlt">plasma</span> produced using RF fields. The <span class="hlt">electron</span> sheath is located near a grounded ring at one end of a negatively biased conducting surface, which is normally a cylinder. Extracted <span class="hlt">electrons</span> pass through the grounded ring in the presence of a steady state axial magnetic field. Sufficiently large magnetic fields and/or RF power into the <span class="hlt">plasma</span> allow for helicon <span class="hlt">plasma</span> generation. The ion loss area is sufficiently large compared to the <span class="hlt">electron</span> loss area to allow for total non-ambipolar extraction of all <span class="hlt">electrons</span> leaving the <span class="hlt">plasma</span>. Voids in the negatively-biased conducting surface allow the time-varying magnetic fields provided by the antenna to inductively couple to the <span class="hlt">plasma</span> within the conducting surface. The conducting surface acts as a Faraday shield, which reduces any time-varying electric fields from entering the conductive surface, i.e. blocks capacitive coupling between the antenna and the <span class="hlt">plasma</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20090043095','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20090043095"><span id="translatedtitle">Non-ambipolar radio-frequency <span class="hlt">plasma</span> <span class="hlt">electron</span> source and systems and methods for generating <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>Hershkowitz, Noah (Inventor); Longmier, Benjamin (Inventor); Baalrud, Scott (Inventor)</p> <p>2009-01-01</p> <p>An <span class="hlt">electron</span> generating device extracts <span class="hlt">electrons</span>, through an <span class="hlt">electron</span> sheath, from <span class="hlt">plasma</span> produced using RF fields. The <span class="hlt">electron</span> sheath is located near a grounded ring at one end of a negatively biased conducting surface, which is normally a cylinder. Extracted <span class="hlt">electrons</span> pass through the grounded ring in the presence of a steady state axial magnetic field. Sufficiently large magnetic fields and/or RF power into the <span class="hlt">plasma</span> allow for helicon <span class="hlt">plasma</span> generation. The ion loss area is sufficiently large compared to the <span class="hlt">electron</span> loss area to allow for total non-ambipolar extraction of all <span class="hlt">electrons</span> leaving the <span class="hlt">plasma</span>. Voids in the negatively-biased conducting surface allow the time-varying magnetic fields provided by the antenna to inductively couple to the <span class="hlt">plasma</span> within the conducting surface. The conducting surface acts as a Faraday shield, which reduces any time-varying electric fields from entering the conductive surface, i.e. blocks capacitive coupling between the antenna and the <span class="hlt">plasma</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_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://www.osti.gov/scitech/biblio/21562064','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/21562064"><span id="translatedtitle">Trapped <span class="hlt">Electron</span> Mode Turbulence Driven Intrinsic Rotation in Tokamak <span class="hlt">Plasmas</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Wang, W. X.; Hahm, T. S.; Ethier, S.; Zakharov, L. E.; Diamond, P. H.</p> <p>2011-02-25</p> <p>Progress from global gyrokinetic simulations in understanding the origin of intrinsic rotation in toroidal <span class="hlt">plasmas</span> is reported. The turbulence-driven intrinsic torque associated with nonlinear residual stress generation due to zonal flow shear induced asymmetry in the parallel wave number spectrum is shown to scale close to linearly with <span class="hlt">plasma</span> gradients and the inverse of the <span class="hlt">plasma</span> current, qualitatively reproducing experimental empirical scalings of intrinsic rotation. The origin of current scaling is found to be enhanced k{sub ||} symmetry breaking induced by the increased radial variation of the safety factor as the current decreases. The intrinsic torque is proportional to the pressure gradient because both turbulence intensity and zonal flow shear, which are two key ingredients for driving residual stress, increase with turbulence drive, which is R/L{sub T{sub e}} and R/L{sub n{sub e}} for the trapped <span class="hlt">electron</span> mode.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/917844','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/917844"><span id="translatedtitle">Observations of underdense <span class="hlt">plasma</span> lens focusing of 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>Thompson, M.C.; Badakov, H.; Rosenzweig, J.B.; Travish, G.; Fliller, R.; Kazakevich, G.M.; Piot, P.; Santucci, J.; Li, J.; Tikhoplav, R.; /Rochester U.</p> <p>2007-06-01</p> <p>Focusing of a 15 MeV, 19 nC <span class="hlt">electron</span> bunch by an underdense <span class="hlt">plasma</span> lens operated just beyond the threshold of the underdense condition has been demonstrated in experiments at the Fermilab NICADD Photoinjector Laboratory (FNPL). The strong 1.9 cm focal-length <span class="hlt">plasma</span>-lens focused both transverse directions simultaneously and reduced the minimum area of the beam spot by a factor of 23. Analysis of the beam-envelope evolution observed near the beam waist shows that the spherical aberrations of this underdense lens are lower than those of an overdense <span class="hlt">plasma</span> lens, as predicted by theory. Correlations between the beam charge and the properties of the beam focus corroborate this conclusion.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015JPlPh..81c9024G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015JPlPh..81c9024G"><span id="translatedtitle">Amplitude saturation effect of a laser-driven <span class="hlt">plasma</span> beat-wave on <span class="hlt">electron</span> accelerations</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Gupta, D. N.; Singh, Mamta; Suk, H.</p> <p>2015-06-01</p> <p>A large-amplitude <span class="hlt">plasma</span> beat-wave driven by two lasers (differing in frequencies equal to the <span class="hlt">plasma</span> frequency) can accelerate the <span class="hlt">plasma</span> <span class="hlt">electrons</span> to a higher energy level. As the <span class="hlt">plasma</span> beat-wave grows, it becomes susceptible to oscillating two-stream instability. The decayed sideband <span class="hlt">plasma</span> wave couples with the pump wave to divert its energy by the instability, and saturates it. The saturated amplitude of the <span class="hlt">plasma</span> beat-wave traps the <span class="hlt">electrons</span> more effectively to accelerate them to higher energy. The saturation of <span class="hlt">plasma</span> beat-wave amplitude is shown to have a significant effect in an <span class="hlt">electron</span> energy gain.</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 id="translatedtitle"><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://www.osti.gov/scitech/servlets/purl/928795','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/928795"><span id="translatedtitle">A <span class="hlt">Plasma</span> Channel Beam Conditioner for a Free <span class="hlt">Electron</span> Laser</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Penn, G.; Sessler, A.M.; Wurtele, J.S.</p> <p>2007-07-01</p> <p>By "conditioning" an <span class="hlt">electron</span> beam, through establishing acorrelation between transverse action and energy within the beam, theperformance of free <span class="hlt">electron</span> lasers (FELs) can be dramatically improved.Under certain conditions, the FEL can perform as if the transverseemittances of the beam were substantially lower than the actual values.After a brief review of the benefits of beam conditioning, we present amethod to generate this correlation through the use of a <span class="hlt">plasma</span> channel.The strong transverse focusing produced by a <span class="hlt">plasma</span> channel (chosen tohave density 1016/cm3) allows the optimal correlation to be achieved in areasonable length channel, of order 1 m. This appears to be a convenientand practical method for achieving conditioned beams, in comparison withother methods which require either a long beamline or multiple passesthrough some type of ring.</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 id="translatedtitle">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 ?-1,4 glycosidic bounds and peptide bonds, respectively.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014APS..DPPTO6010H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014APS..DPPTO6010H"><span id="translatedtitle">Optical Guiding and <span class="hlt">Electron</span> Acceleration in Programmably Modulated <span class="hlt">Plasma</span> Waveguides</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Hine, George; Goers, Andrew; Elle, Jennifer; Feder, Linus; Milchberg, Howard</p> <p>2014-10-01</p> <p>We demonstrate the guiding of relativistically intense laser pulses through programmably structured <span class="hlt">plasma</span> waveguides. The structure of the waveguide is dictated <span class="hlt">electronically</span> using a Spatial Light Modulator (SLM). The waveguides are generated by sending a radially patterned intense laser pulse through an axicon in a clustered gas medium, efficiently ionizing and heating a column of <span class="hlt">plasma</span> which expands to form an optical guiding structure. Intensity modulations at the line focus produce density modulations as the waveguide evolves. Patterning of the intense laser pulse is achieved using the SLM in an interferometric configuration. This SLM patterning technique allows for in situ sculpting of waveguides with arbitrary density structures. Density ramps are generated for <span class="hlt">electron</span> injection, and periodic structures are formed to quasi-phasematch laser wakefield acceleration and direct laser acceleration. This work is supported by the DoE and DTRA.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/22254891','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/22254891"><span id="translatedtitle">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/2011PhPl...18k3504J','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011PhPl...18k3504J"><span id="translatedtitle">Cutoff effects of <span class="hlt">electron</span> velocity distribution to the properties of <span class="hlt">plasma</span> parameters near the <span class="hlt">plasma</span>-sheath boundary</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Jeli?, N.</p> <p>2011-11-01</p> <p>The <span class="hlt">plasma</span> properties under high thermodynamic non-equilibrium condition, established due to the presence of electrically biased electrode, are investigated. Assumption of <span class="hlt">electron</span> cut-off velocity distribution function (VDF), as done by Andrews and Varey in their investigations of the sheath region [J. Phys. A 3, 413 (1970)], has been extended here to both <span class="hlt">plasma</span> and sheath regions. Analytic expressions for the moments of <span class="hlt">electron</span> VDF, as well as for the <span class="hlt">electron</span> screening temperature function dependence on the <span class="hlt">plasma</span>-sheath local potential are derived. In deriving the ion velocity distribution the "standard" assumption of strict <span class="hlt">plasma</span> quasineutrality, or equivalently vanishing of the <span class="hlt">plasma</span> Debye length, is employed, whereas the ions are assumed to be generated at rest over the <span class="hlt">plasma</span> region. However, unlike the standard approach of solving the <span class="hlt">plasma</span> equation, where pure Boltzmann <span class="hlt">electron</span> density profile is used, here we employ modified Boltzmann's <span class="hlt">electron</span> density profile, due to cutoff effect of the <span class="hlt">electron</span> velocity distribution. It is shown that under these conditions the quasineutrality equation solution is characterised by the electric field singularity for any negative value of the electrode bias potential as measured with respect to the <span class="hlt">plasma</span> potential. The point of singularity i.e., the <span class="hlt">plasma</span> length and its dependence on the electrode bias and sheath potential is established for the particular case of ionization profile mechanism proportional to the local <span class="hlt">electron</span> density. Relevant parameters for the kinetic Bohm criterion are explicitly calculated for both ions and <span class="hlt">electrons</span>, for arbitrary electrode bias.</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 id="translatedtitle">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('http://adsabs.harvard.edu/abs/2012APS..DPPJO7003J','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012APS..DPPJO7003J"><span id="translatedtitle">Optical Spectroscopy of High Intensity <span class="hlt">Electron</span> Beam <span class="hlt">Plasmas</span>^1</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; Oliver, Bryan; Bruner, Nichelle; Welch, Dale; Maron, Yitzhak</p> <p>2012-10-01</p> <p>This talk will be an overview of spectroscopic results obtained on the RITS-6 accelerator at Sandia National Laboratories on the Self-Magnetic Pinch (SMP) <span class="hlt">electron</span> beam diode. The SMP diode produces a focused (<3mm diameter), e-beam at 7MeV and 150kA, which is used as an intense, flash x-ray source. During the ˜45ns <span class="hlt">electron</span> beam pulse, <span class="hlt">plasmas</span> are generated on the electrode surfaces which propagate into the A-K vacuum gap, affecting the diode impedance, x-ray spectrum, and pulse-width. These <span class="hlt">plasmas</span> are measured using a series of optical diagnostics including: streak cameras, ICCD cameras, and avalanche photodetectors. Visible spectroscopy is used to gather time and space information on these <span class="hlt">plasmas</span>. Density and temperature calculations are made using detailed, time-dependent, collisional-radiative (CR) and radiation transport modelings. The results are then used in conjunction with hybrid PIC/fluid simulations to model the overall <span class="hlt">plasma</span> behavior. Details regarding the data collection, system calibration, analyses, and interpretation of results will be presented. [4pt] ^1Sandia 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('http://ntrs.nasa.gov/search.jsp?R=19850054010&hterms=electron+beam+atmosphere&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3Delectron%2Bbeam%2Batmosphere','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19850054010&hterms=electron+beam+atmosphere&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3Delectron%2Bbeam%2Batmosphere"><span id="translatedtitle">The spatial evolution of energetic <span class="hlt">electrons</span> and <span class="hlt">plasma</span> waves during the steady state 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>Llobet, X.; Bernstein, W.; Kondradi, A.</p> <p>1985-01-01</p> <p>Experiments, involving the injection of energetic (keV) <span class="hlt">electron</span> beams into the ionosphere-upper atmosphere system from rocket-borne <span class="hlt">electron</span> guns, have provided evidence for the occurrence of strong beam-<span class="hlt">plasma</span> interactions (BPI) both near to and remote from the injection point. However, the flight experiments have not provided clear and unambiguous evidence for the basic physical processes which produce the variety of confusing signatures. A laboratory experimental program was initiated to clarify some of a number of ambiguities regarding the obtained results. The present investigation is concerned with some experimental studies of the evolution of both the beam energy spectrum and the local wave amplitude-frequency spectrum at increasing axial distances from the <span class="hlt">electron</span> gun for a variety of experimental conditions. The results of the studies show that the high frequency beam-<span class="hlt">plasma</span> interaction represents the most important process.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/21550326','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/21550326"><span id="translatedtitle"><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> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/21599373','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/21599373"><span id="translatedtitle"><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.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. PMID:21599373</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://arxiv.org/pdf/1511.05936.pdf','EPRINT'); return false;" href="http://arxiv.org/pdf/1511.05936.pdf"><span id="translatedtitle">Vacuum laser acceleration of relativistic <span class="hlt">electrons</span> using <span class="hlt">plasma</span> mirror injectors</span></a></p> <p><a target="_blank" href="http://www.osti.gov/eprints/">E-print Network</a></p> <p>Thévenet, M; Kahaly, S; Vincenti, H; Vernier, A; Quéré, F; Faure, J</p> <p>2015-01-01</p> <p>Accelerating particles to relativistic energies over very short distances using lasers has been a long standing goal in physics. Among the various schemes proposed for <span class="hlt">electrons</span>, vacuum laser acceleration has attracted considerable interest and has been extensively studied theoretically because of its appealing simplicity: <span class="hlt">electrons</span> interact with an intense laser field in vacuum and can be continuously accelerated, provided they remain at a given phase of the field until they escape the laser beam. But demonstrating this effect experimentally has proved extremely challenging, as it imposes stringent requirements on the conditions of injection of <span class="hlt">electrons</span> in the laser field. Here, we solve this long-standing experimental problem for the first time by using a <span class="hlt">plasma</span> mirror to inject <span class="hlt">electrons</span> in an ultraintense laser field, and obtain clear evidence of vacuum laser acceleration. With the advent of PetaWatt class lasers, this scheme could provide a competitive source of very high charge (nC) and ultrashort rela...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/1022732','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/1022732"><span id="translatedtitle">Ultrafast Diagnostics for <span class="hlt">Electron</span> Beams from Laser <span class="hlt">Plasma</span> Accelerators</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Matlis, N. H.; Bakeman, M.; Geddes, C. G. R.; Gonsalves, T.; Lin, C.; Nakamura, K.; Osterhoff, J.; Plateau, G. R.; Schroeder, C. B.; Shiraishi, S.; Sokollik, T.; van Tilborg, J.; Toth, Cs.; Leemans, W. P.</p> <p>2010-06-01</p> <p>We present an overview of diagnostic techniques for measuring key parameters of <span class="hlt">electron</span> bunches from Laser <span class="hlt">Plasma</span> Accelerators (LPAs). The diagnostics presented here were chosen because they highlight the unique advantages (e.g., diverse forms of electromagnetic emission) and difficulties (e.g., shot-to-shot variability) associated with LPAs. Non destructiveness and high resolution (in space and time and energy) are key attributes that enable the formation of a comprehensive suite of simultaneous diagnostics which are necessary for the full characterization of the ultrashort, but highly-variable <span class="hlt">electron</span> bunches from LPAs.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://cds.cern.ch/record/621752/files/ext-2003-041.pdf','EPRINT'); return false;" href="http://cds.cern.ch/record/621752/files/ext-2003-041.pdf"><span id="translatedtitle">Gas <span class="hlt">Electron</span> Multiplier produced with the <span class="hlt">plasma</span> etching method</span></a></p> <p><a target="_blank" href="http://www.osti.gov/eprints/">E-print Network</a></p> <p>Inuzuka, M; Ozawa, K; Tamagawa, T; Isobe, T</p> <p>2004-01-01</p> <p>We have produced Gas <span class="hlt">Electron</span> Multiplier (GEM) using the <span class="hlt">plasma</span> etching method. The new GEM has holes with a cylindrical shape and can hold up to 520V in nitrogen. Amplification factor was measured as a function of the applied voltage. A gain of 10^4 was obtained in argon-mixture gases. The gain characteristics are very similar to those of the GEMs made at CERN.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015PhPl...22h3505W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015PhPl...22h3505W"><span id="translatedtitle"><span class="hlt">Electron</span> density dependence of impedance probe <span class="hlt">plasma</span> potential measurements</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Walker, D. N.; Blackwell, D. D.; Amatucci, W. E.</p> <p>2015-08-01</p> <p>In earlier works, we used spheres of various sizes as impedance probes in demonstrating a method of determining <span class="hlt">plasma</span> potential, ?p, when the probe radius is much larger than the Debye length, ?D. The basis of the method in those works [Walker et al., Phys. <span class="hlt">Plasmas</span> 13, 032108 (2006); ibid. 15, 123506 (2008); ibid. 17, 113503 (2010)] relies on applying a small amplitude signal of fixed frequency to a probe in a <span class="hlt">plasma</span> and, through network analyzer-based measurements, determining the complex reflection coefficient, ?, for varying probe bias, Vb. The frequency range of the applied signal is restricted to avoid sheath resonant effects and ion contributions such that ?pi ? ? ? ?pe, where ?pi is the ion <span class="hlt">plasma</span> frequency and ?pe is the <span class="hlt">electron</span> <span class="hlt">plasma</span> frequency. For a given frequency and applied bias, both Re(Zac) and Im(Zac) are available from ?. When Re(Zac) is plotted versus Vb, a minimum predicted by theory occurs at ?p [Walker et al., Phys. <span class="hlt">Plasmas</span> 17, 113503 (2010)]. In addition, Im(Zac) appears at, or very near, a maximum at ?p. As ne decreases and the sheath expands, the minimum becomes harder to discern. The purpose of this work is to demonstrate that when using network analyzer-based measurements, ? itself and Im(Zac) and their derivatives are useful as accompanying indicators to Re(Zac) in these difficult cases. We note the difficulties encountered by the most commonly used <span class="hlt">plasma</span> diagnostic, the Langmuir probe. Spherical probe data is mainly used in this work, although we present limited data for a cylinder and a disk. To demonstrate the effect of lowered density as a function of probe geometry, we compare the cylinder and disk using only the indicator Re(Zac).</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/22408201','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/22408201"><span id="translatedtitle">Non-linear <span class="hlt">plasma</span> wake growth of <span class="hlt">electron</span> holes</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Hutchinson, I. H.; Haakonsen, C. B.; Zhou, C.</p> <p>2015-03-15</p> <p>An object's wake in a <span class="hlt">plasma</span> with small Debye length that drifts across the magnetic field is subject to electrostatic <span class="hlt">electron</span> instabilities. Such situations include, for example, the moon in the solar wind and probes in magnetized laboratory <span class="hlt">plasmas</span>. The instability drive mechanism can equivalently be considered drift down the potential-energy gradient or drift up the density-gradient. The gradients arise because the <span class="hlt">plasma</span> wake has a region of depressed density and electrostatic potential into which ions are attracted along the field. The non-linear consequences of the instability are analysed in this paper. At physical ratios of <span class="hlt">electron</span> to ion mass, neither linear nor quasilinear treatment can explain the observation of large-amplitude perturbations that disrupt the ion streams well before they become ion-ion unstable. We show here, however, that <span class="hlt">electron</span> holes, once formed, continue to grow, driven by the drift mechanism, and if they remain in the wake may reach a maximum non-linearly stable size, beyond which their uncontrolled growth disrupts the ions. The hole growth calculations provide a quantitative prediction of hole profile and size evolution. Hole growth appears to explain the observations of recent particle-in-cell simulations.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/22299736','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/22299736"><span id="translatedtitle">Ion boundary conditions in semi-infinite fluid models of <span class="hlt">electron</span> beam-<span class="hlt">plasma</span> interaction</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Levko, Dmitry</p> <p>2014-10-15</p> <p>The modified Bohm criterion is derived for the <span class="hlt">plasma</span> consisting of the monoenergetic <span class="hlt">electron</span> beam and thermal <span class="hlt">electrons</span>. This criterion allows us to define the accurate ion boundary conditions for semi-infinite collisionless fluid models of <span class="hlt">electron</span> beam–<span class="hlt">plasma</span> interaction. In the absence of <span class="hlt">electron</span> beam, these boundary conditions give the classical sheath parameters. When the monoenergetic <span class="hlt">electron</span> beam propagates through the <span class="hlt">plasma</span>, the fluid model with proposed boundary conditions gives the results, which are in qualitative agreement with the results obtained earlier in M. Sharifian and B. Shokri, Phys. <span class="hlt">Plasmas</span> 14, 093503 (2007). However, dynamics and parameters of the <span class="hlt">plasma</span> sheath are different.</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://www.osti.gov/scitech/biblio/22043558','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/22043558"><span id="translatedtitle">Observation of <span class="hlt">electron</span> <span class="hlt">plasma</span> waves inside large amplitude electromagnetic pulses in a temporally growing <span class="hlt">plasma</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Pandey, Shail; Bhattacharjee, Sudeep; Sahu, Debaprasad</p> <p>2012-01-15</p> <p>Observation of <span class="hlt">electron</span> <span class="hlt">plasma</span> waves excited inside high power ({approx}10 kW) short pulse ({approx}20 {mu}s) electromagnetic (em) waves interacting with a gaseous medium (argon) in the pressure range 0.2-2.5 mTorr is reported. The waves have long wavelength ({approx}13 cm) and get damped at time scales slower ({approx}3 {mu}s) than the <span class="hlt">plasma</span> period (0.1-0.3 {mu}s), the energy conveyed to the medium lead to intense ionization (ion density n{sub i} {approx} 10{sup 11} cm{sup -3} and <span class="hlt">electron</span> temperature T{sub e} {approx} 6-8 eV) and rapid growth of the <span class="hlt">plasma</span> ({approx}10{sup 5} s{sup -1}) beyond the waves. Time frequency analysis of the generated oscillations indicate the presence of two principal frequencies centered around 3.8 MHz and 13.0 MHz with a spread {Delta}f {approx} 4 MHz, representing primarily two population of <span class="hlt">electrons</span> in the <span class="hlt">plasma</span> wave. The experimental results are in reasonable agreement with a model that considers spatiotemporal forces of the em wave on the medium, space charges and diffusion.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015JPhD...48P4001R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015JPhD...48P4001R"><span id="translatedtitle">The effect of air on solvated <span class="hlt">electron</span> chemistry at a <span class="hlt">plasma</span>/liquid interface</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.; Mohan Sankaran, R.; Go, David B.</p> <p>2015-10-01</p> <p><span class="hlt">Plasmas</span> in contact with liquids initiate complex chemistry that leads to the generation of a wide range of reactive species. For example, in an electrolytic configuration with a cathodic <span class="hlt">plasma</span> electrode, <span class="hlt">electrons</span> from the <span class="hlt">plasma</span> are injected into the solution, leading to solvation and ensuing reactions. If the gas contains oxygen, electronegative oxygen molecules may react with the <span class="hlt">plasma</span> <span class="hlt">electrons</span> via attachment to reduce the <span class="hlt">electron</span> flux to the solution reducing the production of solvated <span class="hlt">electrons</span> or produce reactive oxygen species that quickly scavenge solvated <span class="hlt">electrons</span> in solution. Here, we applied a total internal reflection absorption spectroscopy technique to compare the concentration of solvated <span class="hlt">electrons</span> produced in solution by an argon <span class="hlt">plasma</span> containing various amounts of oxygen, nitrogen, and air. Our measurements indicate that in oxygen or air ambients, <span class="hlt">electron</span> attachment in the <span class="hlt">plasma</span> phase greatly attenuates the <span class="hlt">electron</span> flux incident on the liquid surface. The remaining <span class="hlt">electrons</span> then solvate but are quickly scavenged by reactive oxygen species in the liquid phase.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19850029363&hterms=technologie&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3Dtechnologie','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19850029363&hterms=technologie&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3Dtechnologie"><span id="translatedtitle">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('http://www.osti.gov/scitech/biblio/22407930','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/22407930"><span id="translatedtitle">The behavior of the <span class="hlt">electron</span> <span class="hlt">plasma</span> boundary in ultraintense laser–highly overdense <span class="hlt">plasma</span> interaction</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Sánchez-Arriaga, G.; Sanz, J.; Debayle, A.; Lehmann, G.</p> <p>2014-12-15</p> <p>The structural stability of the laser/<span class="hlt">plasma</span> interaction is discussed, for the case of a linearly polarized laser beam interacting with a solid at normal incidence. Using a semi-analytical cold fluid model, the dynamics of the <span class="hlt">electron</span> <span class="hlt">plasma</span> boundary (EPB), usually related to the high-order harmonic generation and laser absorption, are presented. While the well-known J?×?B <span class="hlt">plasma</span> oscillations at two times the laser frequency are recovered by the model, several other periodic in time stable solutions exist for exactly the same value of the physical parameters. This novel behavior highlights the importance of the laser pulse history among other factors. Some important features, such as the synchronization between the incident laser and the EPB oscillation, depend on the solution under consideration. A description of the possible types of stable oscillations in a parametric plane involving <span class="hlt">plasma</span> density and laser amplitude is presented. The semi-analytical model is compared with particle-in-cell and semi-Lagrangian Vlasov simulations. They show that, among all the stable solutions, the <span class="hlt">plasma</span> preferentially evolves to a state with the EPB oscillating twice faster than the laser. The effect of the <span class="hlt">plasma</span> temperature and the existence of a ramp in the ion density profile are also discussed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/985205','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/985205"><span id="translatedtitle">Relativistic warm <span class="hlt">plasma</span> theory of nonlinear laser-driven <span class="hlt">electron</span> <span class="hlt">plasma</span> waves</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Schroeder, Carl B.; Esarey, Eric</p> <p>2010-06-30</p> <p>A relativistic, warm fluid model of a nonequilibrium, collisionless <span class="hlt">plasma</span> is developed and applied to examine nonlinear Langmuir waves excited by relativistically-intense, short-pulse lasers. Closure of the covariant fluid theory is obtained via an asymptotic expansion assuming a non-relativistic <span class="hlt">plasma</span> temperature. The momentum spread is calculated in the presence of an intense laser field and shown to be intrinsically anisotropic. Coupling between the transverse and longitudinal momentum variances is enabled by the laser field. A generalized dispersion relation is derived for langmuir waves in a thermal <span class="hlt">plasma</span> in the presence of an intense laser field. Including thermal fluctuations in three velocity-space dimensions, the properties of the nonlinear <span class="hlt">electron</span> <span class="hlt">plasma</span> wave, such as the <span class="hlt">plasma</span> temperature evolution and nonlinear wavelength, are examined, and the maximum amplitude of the nonlinear oscillation is derived. The presence of a relativistically intense laser pulse is shown to strongly influence the maximum <span class="hlt">plasma</span> wave amplitude for non-relativistic phase velocities owing to the coupling between the longitudinal and transverse momentum variances.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014PhPl...21l3107S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014PhPl...21l3107S"><span id="translatedtitle">The behavior of the <span class="hlt">electron</span> <span class="hlt">plasma</span> boundary in ultraintense laser-highly overdense <span class="hlt">plasma</span> interaction</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Sánchez-Arriaga, G.; Sanz, J.; Debayle, A.; Lehmann, G.</p> <p>2014-12-01</p> <p>The structural stability of the laser/<span class="hlt">plasma</span> interaction is discussed, for the case of a linearly polarized laser beam interacting with a solid at normal incidence. Using a semi-analytical cold fluid model, the dynamics of the <span class="hlt">electron</span> <span class="hlt">plasma</span> boundary (EPB), usually related to the high-order harmonic generation and laser absorption, are presented. While the well-known J × B <span class="hlt">plasma</span> oscillations at two times the laser frequency are recovered by the model, several other periodic in time stable solutions exist for exactly the same value of the physical parameters. This novel behavior highlights the importance of the laser pulse history among other factors. Some important features, such as the synchronization between the incident laser and the EPB oscillation, depend on the solution under consideration. A description of the possible types of stable oscillations in a parametric plane involving <span class="hlt">plasma</span> density and laser amplitude is presented. The semi-analytical model is compared with particle-in-cell and semi-Lagrangian Vlasov simulations. They show that, among all the stable solutions, the <span class="hlt">plasma</span> preferentially evolves to a state with the EPB oscillating twice faster than the laser. The effect of the <span class="hlt">plasma</span> temperature and the existence of a ramp in the ion density profile are also discussed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.math.rutgers.edu/~lebowitz/PUBLIST/jllpub-348.pdf','EPRINT'); return false;" href="http://www.math.rutgers.edu/~lebowitz/PUBLIST/jllpub-348.pdf"><span id="translatedtitle"><span class="hlt">Electron</span> velocity distribution in a weakly ionized <span class="hlt">plasma</span> with an external electric field</span></a></p> <p><a target="_blank" href="http://www.osti.gov/eprints/">E-print Network</a></p> <p>Lebowitz, Joel</p> <p></p> <p><span class="hlt">Electron</span> velocity distribution in a weakly ionized <span class="hlt">plasma</span> with an external electric field A. V(v) of the <span class="hlt">electron</span> component of a weakly ionized <span class="hlt">plasma</span> is investigated in a spatially homogeneous external electric with a priori specified temperatures while the <span class="hlt">electron-electron</span> interactions are given by a Landau</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://mwalker.gatech.edu/papers/2015_Sam_PoP2.pdf','EPRINT'); return false;" href="http://mwalker.gatech.edu/papers/2015_Sam_PoP2.pdf"><span id="translatedtitle">Effect of secondary <span class="hlt">electron</span> emission on the <span class="hlt">plasma</span> sheath S. Langendorf and M. Walker</span></a></p> <p><a target="_blank" href="http://www.osti.gov/eprints/">E-print Network</a></p> <p>Walker, Mitchell</p> <p></p> <p>Effect of secondary <span class="hlt">electron</span> emission on the <span class="hlt">plasma</span> sheath S. Langendorf and M. Walker Citation. A 30, 051303 (2012); 10.1116/1.4737615 Dependence of ion sheath collapse on secondary <span class="hlt">electron</span> emission.1063/1.1755850 Effect of secondary <span class="hlt">electron</span> emission on sheath potential in an <span class="hlt">electron</span> cyclotron resonance <span class="hlt">plasma</span> J</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/21137443','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/21137443"><span id="translatedtitle">Investigation of <span class="hlt">plasma</span> distribution in <span class="hlt">electron</span>-focused electric field enhanced glow discharge <span class="hlt">plasma</span> immersion ion implantation</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Lu Qiuyuan; Li Liuhe; Fu, Ricky K. Y.; Chu, Paul K.</p> <p>2008-08-15</p> <p>In enhanced glow discharge <span class="hlt">plasma</span> immersion ion implantation (EGDPIII) that involves a small pointed anode and large area tabular cathode, the high negative substrate bias not only acts as the <span class="hlt">plasma</span> producer but also supplies the implantation voltage. Consequently, an electric field is created to focus the <span class="hlt">electrons</span> and the <span class="hlt">electron</span>-focusing field enhances the glow discharge process. In this work, the <span class="hlt">plasma</span> distribution is measured using a Langmuir probe to obtain the <span class="hlt">plasma</span> density. Numerical interpolation is performed to obtain the <span class="hlt">plasma</span> density distribution throughout the entire discharge region. The effects of different distances between the anode and cathode on the glow discharge characteristics and the influence of the <span class="hlt">plasma</span> <span class="hlt">electron</span> density are also evaluated. Our results experimentally verify the <span class="hlt">electron</span>-focusing phenomenon and suggest optimal processing windows for enhanced ionization rates and efficiency in EGDPIII.</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 id="translatedtitle">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 ? e/? 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('http://adsabs.harvard.edu/abs/2015PSST...24c4011G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015PSST...24c4011G"><span id="translatedtitle">Localized <span class="hlt">electron</span> heating and density peaking in downstream helicon <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>Ghosh, Soumen; Barada, K. K.; Chattopadhyay, P. K.; Ghosh, J.; Bora, D.</p> <p>2015-06-01</p> <p>Localized <span class="hlt">electron</span> temperature and density peaking at different axial locations in the downstream helicon <span class="hlt">plasma</span> have been observed in a linear helicon device with both geometrical and magnetic expansion. The discharge is produced with an m=+1 right helical antenna powered by a RF source operating at 13.56 MHz. Axial wave field measurement shows the presence of damped helicon waves with standing wave character folded into it even at low densities (˜ {{10}16} m-3 ). The measured helicon wavelength is just about twice the antenna length and the phase velocity ?ft({{v}p}\\right) is almost the speed required for <span class="hlt">electron</span> impact ionization. These experimental observations strongly advocate the Landau damping heating and density production by the helicon waves, particularly in low density <span class="hlt">plasma</span> such as ours. The <span class="hlt">electron</span> temperature maximizes at 35-45?cm away from the antenna center in our experiments indicating a local source of heating at those locations. Different mechanisms responsible for this additional heating at a particular spatial location have been discussed for their possible roles. Further downstream from the location of the maximum <span class="hlt">electron</span> temperature, a density peak located 55-65?cm away from the antenna is observed. This downstream density peaking can be explained through pressure balance in the system.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/22036815','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/22036815"><span id="translatedtitle">Enhanced <span class="hlt">electron</span> field emission from <span class="hlt">plasma</span>-nitrogenated carbon nanotips</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Wang, B. B.; Cheng, Q. J.; Ostrikov, K.; Zhong, X. X.; Wang, Y. Q.; Chen, Y. A.</p> <p>2012-02-15</p> <p>Nitrogenated carbon nanotips (NCNTPs) are synthesized by <span class="hlt">plasma</span>-enhanced hot filament chemical vapor deposition from the hydrogen, methane, and nitrogen gas mixtures with different flow rate ratios of hydrogen to nitrogen. The morphological, structural, compositional, and <span class="hlt">electron</span> field emission (EFE) properties of the NCNTPs were investigated by field emission scanning <span class="hlt">electron</span> microscopy, Raman spectroscopy, x ray photoelectron spectroscopy, and EFE high-vacuum system. It is shown that the NCNTPs deposited at an intermediate flow rate ratio of hydrogen to nitrogen feature the best size/shape and pattern uniformity, the highest nanotip density, the highest nitrogen concentration, as well as the best <span class="hlt">electron</span> field emission performance. Several factors that come into play along with the nitrogen incorporation, such as the combined effect of the <span class="hlt">plasma</span> sputtering and etching, the transition of sp{sup 3} carbon clusters to sp{sup 2} carbon clusters, the increase of the size of the sp{sup 2} clusters, as well as the reduction of the work function, have been examined to interpret these experimental findings. Our results are highly relevant to the development of the next generation <span class="hlt">electron</span> field emitters, flat panel displays, atomic force microscope probes, and several other advanced applications.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015PhLA..379.2661J','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015PhLA..379.2661J"><span id="translatedtitle"><span class="hlt">Electronic</span> and transmission properties of magnetotunnel junctions of cobalt/iron intercalated bilayer two dimensional <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>Jiao, N.; Xie, M. D.; Zhou, P.; Sun, L. Z.</p> <p>2015-10-01</p> <p>Density functional theory and the nonequilibrium Green's function method are used to study the <span class="hlt">electronic</span> properties and tunneling magnetoresistance (TMR) of magnetotunnel junctions (MTJs) based on Co/Fe intercalated bilayer graphene (bi-Gr), bilayer hexagonal boron nitride (bi-h-BN), and bilayer Gr-h-BN (bi-GBN). The spin-polarized bands around the Fermi energy of the two dimensional bilayer <span class="hlt">sheets</span> are modulated by the intercalated cobalt. The TMR ratio reaches 169.94% and 173.00% for cobalt and iron intercalated Ni|bi-GBN|Ni MTJs, respectively. We observe that the Co/Fe intercalated bi-GBN is a promising candidate as a spacer in MTJs for spintronics.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19910026464&hterms=Earth+layers&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D60%26Ntt%3DEarth%2527s%2Blayers','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19910026464&hterms=Earth+layers&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D60%26Ntt%3DEarth%2527s%2Blayers"><span id="translatedtitle">ISEE observations of low frequency waves and ion distribution function evolution 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>Elphic, R. C.; Gary, S. P.</p> <p>1990-01-01</p> <p>This paper describes ISEE <span class="hlt">plasma</span> and magnetic fluctuation observations during two crossings of the <span class="hlt">plasma</span> <span class="hlt">sheet</span> boundary layer (PSBL) in the earth's magnetotail. Distribution function observations show that the counterstreaming ion components undergo pitch-angle scattering and evolve into a shell distribution in velocity space. This evolution is correlated with the development of low frequency, low amplitude magnetic fluctuations. However, the measured wave amplitudes are insufficient to accomplish the observed degree of ion pitch-angle scatttering locally; the near-earth distributions may be the result of processes occurring much farther down the magnetotail. Results show a clear correlation between the ion component beta and the relative streaming speed of the two components, suggesting that electromagnetic ion/ion instabilities do play an important role in the scattering of PSBL ions.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015JPhCS.653a2006A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015JPhCS.653a2006A"><span id="translatedtitle">Laser <span class="hlt">electron</span> acceleration in the prepulse produced <span class="hlt">plasma</span> corona</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Andreev, N. E.; Povarnitsyn, M. E.; Pugachev, L. P.; Levashov, P. R.</p> <p>2015-11-01</p> <p>The generation of hot <span class="hlt">electrons</span> at grazing incidence of a subpicosecond relativistic-intense laser pulse onto the plane solid target is analyzed for the parameters of the petawatt class laser systems. We study the preplasma formation on the surface of solid Al target produced by the laser prepulses with different time structure. For modeling of the preplasma dynamics we use a wide-range two-temperature hydrodynamic model. As a result of simulations, the preplasma expansion under the action of the laser prepulse and the <span class="hlt">plasma</span> density profiles for different contrast ratios of the nanosecond pedestal are found. These density profiles were used as the initial density distributions in 3-D PIC simulations of <span class="hlt">electron</span> acceleration by the main P-polarized laser pulse. Results of modeling demonstrate the substantial increase of the characteristic energy and number of accelerated <span class="hlt">electrons</span> for the grazing incidence of a subpicosecond intense laser pulse in comparison with the laser-target interaction at normal incidence.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013AGUFMSM13B2146J','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013AGUFMSM13B2146J"><span id="translatedtitle">Study of <span class="hlt">Electron</span>-scale Dissipation near the X-line During Magnetic Reconnection in a 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>Ji, H.; Yoo, J.; Dorfman, S. E.; Jara-Almonte, J.; Yamada, M.; Swanson, C.; Daughton, W. S.; Roytershteyn, V.; Kuwahata, A.; Ii, T.; Inomoto, M.; Ono, Y.; von Stechow, A.; Grulke, O.; Phan, T.; Mozer, F.; Bale, S. D.</p> <p>2013-12-01</p> <p>Despite its disruptive influences on the large-scale structures of space and solar <span class="hlt">plasmas</span>, the crucial topological changes and associated dissipation during magnetic reconnection take place only near an X-line within thin singular layers. In the modern collisionless models where <span class="hlt">electrons</span> and ions are allowed to move separately, it has been predicted that ions exhaust efficiently through a thicker, ion-scale dissipative layer while mobile <span class="hlt">electrons</span> can evacuate through a thinner, <span class="hlt">electron</span>-scale dissipation layer, allowing for efficient release of magnetic energy. While ion dissipation layers have been frequently detected, the existence of election layers near the X-line and the associated dissipation structures and mechanisms are still an open question, and will be a main subject of the coming MMS mission. In this presentation, we will summarize our efforts in the past a few years to study <span class="hlt">electron</span>-scale dissipation in a well-controlled and well-diagnosed reconnecting current <span class="hlt">sheet</span> in a laboratory <span class="hlt">plasma</span>, with close comparisons with the state-of-the-art, 2D and 3D fully kinetic simulations. Key results include: (1) positive identification of electromagnetic waves detected at the current <span class="hlt">sheet</span> center as long wave-length, lower-hybrid drift instabilities (EM-LHDI), (2) however, there is strong evidence that this EM-LHDI cannot provide the required force to support the reconnection electric field, (3) detection of 3D flux-rope-like magnetic structures during impulsive reconnection events, and (4) <span class="hlt">electrons</span> are heated through non-classical mechanisms near the X-line with a small but clear temperature anisotropy. These results, unfortunately, do not resolve the outstanding discrepancies on <span class="hlt">electron</span> layer thickness between best available experiments and fully kinetic simulations. To make further progress, we are continuously pushing in the both experimental and numerical frontiers. Experimentally, we started investigations on EM-LHDI and <span class="hlt">electron</span> heating as a function of guide field strength and symmetry of reconnection geometry, with new attempts to measure non-thermal <span class="hlt">electrons</span> and higher frequency fluctuations. Numerically, we started investigations of kinetic simulations at realistic ratios of <span class="hlt">electron</span> <span class="hlt">plasma</span> frequency to cyclotron frequency, and also at realistic ratios of ion mass to <span class="hlt">electron</span> mass. The most updated results of these new projects will be presented with discussions on the relevance to space observations.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.phy.mtu.edu/pandey/publications/LPPP2006.pdf','EPRINT'); return false;" href="http://www.phy.mtu.edu/pandey/publications/LPPP2006.pdf"><span id="translatedtitle">First-principles study of the stability and <span class="hlt">electronic</span> properties of <span class="hlt">sheets</span> and nanotubes of elemental boron</span></a></p> <p><a target="_blank" href="http://www.osti.gov/eprints/">E-print Network</a></p> <p>Pandey, Ravi</p> <p></p> <p>of elemental boron Kah Chun Lau a , Ranjit Pati a , Ravindra Pandey a,*, Andrew C. Pineda b,c a Department The structural and <span class="hlt">electronic</span> properties of <span class="hlt">sheets</span> and nanotubes of boron are investigated using density Elsevier B.V. All rights reserved. Boron holds a unique place among the elements of the periodic table</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/212790','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/212790"><span id="translatedtitle">To the problem of <span class="hlt">electron</span> temperature control in <span class="hlt">plasma</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Galechyan, G.A.; Anna, P.R.</p> <p>1995-12-31</p> <p>One of the main problems in low temperature <span class="hlt">plasma</span> is control <span class="hlt">plasma</span> parameters at fixed values of current and gas pressure in the discharge. It is known that an increase in the intensity of sound wave directed along the positive column to values in excess of a definite threshold leads to essential rise of the temperature of <span class="hlt">electrons</span>. However, no less important is the reduction of <span class="hlt">electron</span> temperature in the discharge down to the value less than that in <span class="hlt">plasma</span> in the absence external influence. It is known that to reduce the <span class="hlt">electron</span> temperature in the <span class="hlt">plasma</span> of CO{sub 2} laser, easily ionizable admixture are usually introduced in the discharge area with the view of increasing the overpopulation. In the present work we shall show that the value of <span class="hlt">electron</span> temperature can be reduced by varying of sound wave intensity at its lower values. The experiment was performed on an experimental setup consisted of the tube with length 52 cm and diameter 9.8 cm, two electrodes placed at the distance of 27 cm from each other. An electrodynamical radiator of sound wave was fastened to one of tube ends. Fastened to the flange at the opposite end was a microphone for the control of sound wave parameters. The studies were performed in range of pressures from 40 to 180 Torr and discharge currents from 40 to 110 mA. The intensity of sound wave was varied from 74 to 92 dB. The measurement made at the first resonance frequency f = 150 Hz of sound in the discharge tube, at which a quarter of wave length keep within the length of the tube. The measurement of longitudinal electric field voltage in <span class="hlt">plasma</span> of positive column was conducted with the help of two probes according to the compensation method. Besides, the measurement of gas temperature in the discharge were taken. Two thermocouple sensors were arranged at the distance of 8 cm from the anode, one of them being installed on the discharge tube axis, the second-fixed the tube wall.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/1007180','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/1007180"><span id="translatedtitle">Trapped <span class="hlt">Electron</span> Mode Turbulence Driven Intrinsic Rotation in Tokamak <span class="hlt">Plasmas</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Wang, W. X.; Hahm, T. S.; Ethier, S.; Zakharov, L. E.</p> <p>2011-02-07</p> <p>Recent progress from global gyrokinetic simulations in understanding the origin of intrinsic rotation in toroidal <span class="hlt">plasmas</span> is reported with emphasis on <span class="hlt">electron</span> thermal transport dominated regimes. The turbulence driven intrinsic torque associated with nonlinear residual stress generation by the fluctuation intensity and the intensity gradient in the presence of zonal flow shear induced asymmetry in the parallel wavenumber spectrum is shown to scale close to linearly with <span class="hlt">plasma</span> gradients and the inverse of the <span class="hlt">plasma</span> current. These results qualitatively reproduce empirical scalings of intrinsic rotation observed in various experiments. The origin of current scaling is found to be due to enhanced kll symmetry breaking induced by the increased radial variation of the safety factor as the current decreases. The physics origin for the linear dependence of intrinsic torque on pressure gradient is that both turbulence intensity and the zonal flow shear, which are two key ingredients for driving residual stress, increase with the strength of turbulence drive, which is R0/LTe and R0/Lne for the trapped <span class="hlt">electron</span> mode. __________________________________________________</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19920055082&hterms=shock+hugoniot&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3Dshock%2Bhugoniot','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19920055082&hterms=shock+hugoniot&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3Dshock%2Bhugoniot"><span id="translatedtitle">Relativistic, perpendicular shocks in <span class="hlt">electron</span>-positron <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>Gallant, Yves A.; Hoshino, Masahiro; Langdon, A. B.; Arons, Jonathan; Max, Claire E.</p> <p>1992-01-01</p> <p>One-dimensional particle-in-cell <span class="hlt">plasma</span> simulations are used to examine the mechanical structure and thermalization properties of collisionless relativistic shock waves in <span class="hlt">electron</span>-positron <span class="hlt">plasmas</span>. Shocks propagating perpendicularly to the magnetic field direction are considered. It is shown that these shock waves exist, and that they are completely parameterized by the ratio of the upstream Poynting flux to the upstream kinetic energy flux. The way in which the Rankine-Hugoniot shock jump conditions are modified by the presence of wave fluctuations is shown, and they are used to provide a macroscopic description of these collisionless shock flows. The results of a 2D simulation that demonstrates the generality of these results beyond the assumption of the 1D case are discussed. It is suggested that the thermalization mechanism is the formation of a synchrotron maser by the coherently reflected particles in the shock front. Because the downstream medium is thermalized, it is argued that perpendicular shocks in pure <span class="hlt">electron</span>-positron <span class="hlt">plasmas</span> are not candidates as nonthermal particle accelerators.</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('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4169717','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4169717"><span id="translatedtitle">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://sdpha2.ucsd.edu/pdf_files/PP3_1250_96.pdf','EPRINT'); return false;" href="http://sdpha2.ucsd.edu/pdf_files/PP3_1250_96.pdf"><span id="translatedtitle">Temperature and anisotropic-temperature relaxation measurements in cold, pure-<span class="hlt">electron</span> <span class="hlt">plasmas</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/eprints/">E-print Network</a></p> <p>California at San Diego, University of</p> <p></p> <p>, ultra-high vacuum, pure-<span class="hlt">electron</span> <span class="hlt">plasma</span> trap. The rate at which the temperatures parallel, and T is the <span class="hlt">plasma</span> temperature. The <span class="hlt">plasma</span> temperatures parallel and perpendicular to the mag- netic field need operation: the <span class="hlt">electron</span> source, three collimated, cylindrical electrodes, and five charge collectors. All</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://htx.pppl.gov/publication/Conference/IEPC09_024%20cathode.pdf','EPRINT'); return false;" href="http://htx.pppl.gov/publication/Conference/IEPC09_024%20cathode.pdf"><span id="translatedtitle">A Parametric Study of <span class="hlt">Electron</span> Extraction from a Low Frequency Inductively Coupled RF-<span class="hlt">Plasma</span> Source</span></a></p> <p><a target="_blank" href="http://www.osti.gov/eprints/">E-print Network</a></p> <p></p> <p></p> <p>: The <span class="hlt">electron</span> extraction from a low-frequency (2 MHz) inductively-coupled rf-<span class="hlt">plasma</span> cathode is characterized cathodes with thermionic emitters made from low work function materials are extensively used in <span class="hlt">plasma</span> <span class="hlt">plasma</span>. At low pressures, the arcjet operation requires <span class="hlt">electron</span> emission from its cathode to maintain</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://sdpha2.ucsd.edu/pdf_files/pop_anderegg_03.pdf','EPRINT'); return false;" href="http://sdpha2.ucsd.edu/pdf_files/pop_anderegg_03.pdf"><span id="translatedtitle">Thermally excited TrivelpieceGould modes as a pure <span class="hlt">electron</span> <span class="hlt">plasma</span> temperature diagnostica...</span></a></p> <p><a target="_blank" href="http://www.osti.gov/eprints/">E-print Network</a></p> <p>California at San Diego, University of</p> <p></p> <p>Thermally excited Trivelpiece­Gould modes as a pure <span class="hlt">electron</span> <span class="hlt">plasma</span> temperature diagnostica... F; accepted 19 December 2002 Thermally excited <span class="hlt">plasma</span> modes are observed in trapped, near-thermal-equilibrium pure <span class="hlt">electron</span> <span class="hlt">plasmas</span> over a temperature range of 0.05 kT 5 eV. The modes are excited and damped</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/22113417','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/22113417"><span id="translatedtitle">Wakefields generated by collisional neutrinos in neutral-<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>Tinakiche, Nouara</p> <p>2013-02-15</p> <p>A classical fluid description is adopted to investigate nonlinear interaction between an <span class="hlt">electron</span>-type neutrino beam and a relativistic collisionless unmagnetized neutral-<span class="hlt">electron</span>-positron <span class="hlt">plasma</span>. In this work, we consider the collisions of the neutrinos with neutrals in the <span class="hlt">plasma</span> and study their effect on the generation of wakefields in this <span class="hlt">plasma</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://htx.pppl.gov/publication/Journal/PhysRevLett.111.075002.pdf','EPRINT'); return false;" href="http://htx.pppl.gov/publication/Journal/PhysRevLett.111.075002.pdf"><span id="translatedtitle">Kinetic Theory of <span class="hlt">Plasma</span> Sheaths Surrounding <span class="hlt">Electron</span>-Emitting Surfaces J. P. Sheehan* and N. Hershkowitz</span></a></p> <p><a target="_blank" href="http://www.osti.gov/eprints/">E-print Network</a></p> <p></p> <p></p> <p>cathode in the afterglow of an rf <span class="hlt">plasma</span>. The measured sheath potential shrunk to zero as the <span class="hlt">plasma</span>Kinetic Theory of <span class="hlt">Plasma</span> Sheaths Surrounding <span class="hlt">Electron</span>-Emitting Surfaces J. P. Sheehan* and N. D. Kaganovich, H. Wang, and Y. Raitses Princeton <span class="hlt">Plasma</span> Physics Laboratory, Princeton, New Jersey</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://farside.ph.utexas.edu/Papers/1.3374427.pdf','EPRINT'); return false;" href="http://farside.ph.utexas.edu/Papers/1.3374427.pdf"><span id="translatedtitle">Magnetic reconnection in weakly collisional highly magnetized <span class="hlt">electron</span>-ion <span class="hlt">plasmas</span> Richard Fitzpatrick</span></a></p> <p><a target="_blank" href="http://www.osti.gov/eprints/">E-print Network</a></p> <p>Fitzpatrick, Richard</p> <p></p> <p>Magnetic reconnection in weakly collisional highly magnetized <span class="hlt">electron</span>-ion <span class="hlt">plasmas</span> Richard during magnetic reconnection: A simulation scaling study Phys. <span class="hlt">Plasmas</span> 21, 122902 (2014); 10.1063/1.4904203 Magnetic reconnection in a weakly ionized <span class="hlt">plasma</span> Phys. <span class="hlt">Plasmas</span> 20, 061202 (2013); 10</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/22252096','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/22252096"><span id="translatedtitle">Fluid aspects of <span class="hlt">electron</span> streaming instability in <span class="hlt">electron</span>-ion <span class="hlt">plasmas</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Jao, C.-S.; Hau, L.-N.; Department of Physics, National Central University, Jhongli, Taiwan </p> <p>2014-02-15</p> <p><span class="hlt">Electrons</span> streaming in a background <span class="hlt">electron</span> and ion <span class="hlt">plasma</span> may lead to the formation of electrostatic solitary wave (ESW) and hole structure which have been observed in various space <span class="hlt">plasma</span> environments. Past studies on the formation of ESW are mostly based on the particle simulations due to the necessity of incorporating particle's trapping effects. In this study, the fluid aspects and thermodynamics of streaming instabilities in <span class="hlt">electron</span>-ion <span class="hlt">plasmas</span> including bi-streaming and bump-on-tail instabilities are addressed based on the comparison between fluid theory and the results from particle-in-cell simulations. The energy closure adopted in the fluid model is the polytropic law of d(p?{sup ??})/dt=0 with ? being a free parameter. Two unstable modes are identified for the bump-on-tail instability and the growth rates as well as the dispersion relation of the streaming instabilities derived from the linear theory are found to be in good agreement with the particle simulations for both bi-streaming and bump-on-tail instabilities. At the nonlinear saturation, 70% of the <span class="hlt">electrons</span> are trapped inside the potential well for the drift velocity being 20 times of the thermal velocity and the p?{sup ??} value is significantly increased. Effects of ion to <span class="hlt">electron</span> mass ratio on the linear fluid theory and nonlinear simulations are also examined.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/21371250','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/21371250"><span id="translatedtitle">Study of <span class="hlt">plasma</span> heating induced by fast <span class="hlt">electrons</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Morace, A.; Batani, D.; Redaelli, R.; Magunov, A.; Fourment, C.; Santos, J. J.; Malka, G.; Boscheron, A.; Nazarov, W.; Vinci, T.; Okano, Y.; Inubushi, Y.; Nishimura, H.; Flacco, A.; Spindloe, C.; Tolley, M.</p> <p>2009-12-15</p> <p>We studied the induced <span class="hlt">plasma</span> heating in three different kinds of targets: mass limited, foam targets, and large mass targets. The experiment was performed at Alise Laser Facility of CEA/CESTA. The laser system emitted a approx1 ps pulse with approx10 J energy at a wavelength of approx1 {mu}m. Mass limited targets had three layers with thicknesses of 10 {mu}m C{sub 8}H{sub 8}, 1 {mu}m C{sub 8}H{sub 7}Cl, and 10 {mu}m C{sub 8}H{sub 8} with size of 100x100 {mu}m{sup 2}. Detailed spectroscopic analysis of x rays emitted from the Cl tracer showed that it was possible to heat up the <span class="hlt">plasma</span> from mass limited targets to a temperature of approx250 eV with density of approx10{sup 21} cm{sup -3}. The <span class="hlt">plasma</span> heating is only produced by fast <span class="hlt">electron</span> transport in the target, being the 10 {mu}m C{sub 8}H{sub 8} overcoating thick enough to prevent any possible direct irradiation of the tracer layer even taking into account mass-ablation due to the prepulse. These results demonstrate that with mass limited targets, it is possible to generate a <span class="hlt">plasma</span> heated up to several hundreds eV. It is also very important for research concerning high energy density phenomena and for fast ignition (in particular for the study of fast <span class="hlt">electrons</span> transport and induced heating).</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://arxiv.org/pdf/1503.06082.pdf','EPRINT'); return false;" href="http://arxiv.org/pdf/1503.06082.pdf"><span id="translatedtitle">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://www.osti.gov/eprints/">E-print Network</a></p> <p>Nilsson, E; Peysson, Y; Granetz, R S; Saint-Laurent, F; Vlainic, M</p> <p>2015-01-01</p> <p>Runaway <span class="hlt">electrons</span> (REs) can be generated in tokamak <span class="hlt">plasmas</span> if the accelerating force from the toroidal electric field exceeds the collisional drag force due to Coulomb collisions with the background <span class="hlt">plasma</span>. In ITER, disruptions are expected to generate REs mainly through knock-on collisions, 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 REs. 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 3-D kinetic description, since these <span class="hlt">electrons</span> are highly sensitive to the magnetic non-uniformity of a toroidal configuration. A bounce-averaged knock-on source term is derived. The generation of REs from the combined effect of Dreicer mechanism and knock-on collision process is studied with the code LUKE, a s...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/22085965','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/22085965"><span id="translatedtitle">Diagnosis of gas temperature, <span class="hlt">electron</span> temperature, and <span class="hlt">electron</span> density in helium atmospheric pressure <span class="hlt">plasma</span> jet</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Chang Zhengshi; Zhang Guanjun; Shao Xianjun; Zhang Zenghui</p> <p>2012-07-15</p> <p>The optical emission spectra of helium atmospheric pressure <span class="hlt">plasma</span> jet (APPJ) are captured with a three grating spectrometer. The grating primary spectrum covers the whole wavelength range from 200 nm to 900 nm, with the overlapped grating secondary spectrum appearing from 500 nm to 900 nm, which has a higher resolution than that of the grating primary spectrum. So the grating secondary spectrum of OH (A{sup 2}{Sigma} {sup +}({upsilon} Prime = 0) {yields} X{sup 2}{Pi}({upsilon} Double-Prime = 0)) is employed to calculate the gas temperature (T{sub g}) of helium APPJ. Moreover, the <span class="hlt">electron</span> temperature (T{sub e}) is deduced from the Maxwellian <span class="hlt">electron</span> energy distribution combining with T{sub g}, and the <span class="hlt">electron</span> density (n{sub e}) is extracted from the <span class="hlt">plasma</span> absorbed power. The results are helpful for understanding the physical property of APPJs.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013JPlPh..79..473H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013JPlPh..79..473H"><span id="translatedtitle">The scaling of collisionless magnetic reconnection in an <span class="hlt">electron</span>-positron <span class="hlt">plasma</span> with non-scalar pressure</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Hosseinpour, M.; Mohammadi, M. A.; Biabani, S.; Biabani</p> <p>2013-10-01</p> <p>Collisionless magnetic reconnection via tearing instability in non-relativistic <span class="hlt">electron</span>-positron (pair) <span class="hlt">plasma</span> with an anisotropic pressure is investigated. The equilibrium magnetic field is considered to be sheared force-free, and a set of linearized collisionless Magnetohydrodynamics equations describes the evolution of reconnection dynamics. A linear analytical analysis, based on scaling, demonstrates that in such a pair <span class="hlt">plasma</span>, breaking the frozen in flow constraint for field lines can be mainly provided by the non-gyrotropic pressure of <span class="hlt">electrons</span> and positrons (rather than the particle bulk inertia) when the current <span class="hlt">sheet</span> width is smaller than the particle Larmor radius (?x < r L ). This condition is satisfied when ? > d 2 (d = c/? p is the particle skin-depth with the <span class="hlt">electron</span>/positron frequency ? p and ? = 8?P (0)/B 0 2 << 1). Meanwhile, on top of the Lorentz force and in the absence of the reconnection facilitating mechanism of the Hall effect, non-scalar pressure force can accelerate bulk <span class="hlt">plasma</span> into the diffusion region at the scale lengths of the order of dx. Therefore, the respective regime of tearing instability proceeds much faster compared with the case of an isotropic pressure with a new dimensionless growth rate of (?? A ) ~ d.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010ChPhB..19f4210Z','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010ChPhB..19f4210Z"><span id="translatedtitle"><span class="hlt">Electron</span> trajectory evaluation in laser-<span class="hlt">plasma</span> interaction for effective output beam</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Zobdeh, P.; Sadighi-Bonabi, R.; Afarideh, H.</p> <p>2010-06-01</p> <p>Using the ellipsoidal cavity model, the quasi-monoenergetic <span class="hlt">electron</span> output beam in laser-<span class="hlt">plasma</span> interaction is described. By the cavity regime the quality of <span class="hlt">electron</span> beam is improved in comparison with those generated from other methods such as periodic <span class="hlt">plasma</span> wave field, spheroidal cavity regime and <span class="hlt">plasma</span> channel guided acceleration. Trajectory of <span class="hlt">electron</span> motion is described as hyperbolic, parabolic or elliptic paths. We find that the self-generated <span class="hlt">electron</span> bunch has a smaller energy width and more effective gain in energy spectrum. Initial condition for the ellipsoidal cavity is determined by laser-<span class="hlt">plasma</span> parameters. The <span class="hlt">electron</span> trajectory is influenced by its position, energy and cavity electrostatic potential.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/22218638','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/22218638"><span id="translatedtitle"><span class="hlt">Electron</span> beam driven lower hybrid waves in a dusty <span class="hlt">plasma</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Prakash, Ved; Vijayshri; Sharma, Suresh C.; Gupta, Ruby</p> <p>2013-05-15</p> <p>An <span class="hlt">electron</span> beam propagating through a magnetized dusty <span class="hlt">plasma</span> drives electrostatic lower hybrid waves to instability via Cerenkov interaction. A dispersion relation and the growth rate of the instability for this process have been derived taking into account the dust charge fluctuations. The frequency and the growth rate of the unstable wave increase with the relative density of negatively charged dust grains. Moreover, the growth rate of the instability increases with beam density and scales as the one-third power of the beam density. In addition, the dependence of the growth rate on the beam velocity is also discussed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19900050659&hterms=1580&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3D%2526%25231580','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19900050659&hterms=1580&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3D%2526%25231580"><span id="translatedtitle">Deposition of diamondlike films by <span class="hlt">electron</span> cyclotron resonance microwave <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>Pool, F. S.; Shing, Y. H.</p> <p>1990-01-01</p> <p>Hard a-C:H films have been deposited through <span class="hlt">electron</span> cyclotron resonance (ECR) microwave <span class="hlt">plasma</span> decomposition of CH4 diluted with H2 gas. It has been found that hard diamondlike films could only be produced under a RF-induced negative self-bias of the substrate stage. Raman spectra indicate the deposition of two distinct film types: one film type exhibiting well-defined bands at 1360 and 1580/cm and another displaying a broad Raman peak centered at approximately 1500/cm. Variation of the mirror magnetic-field profile of the ECR system was examined, demonstrating the manipulation of film morphology through the extraction of different ion energies.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/22127014','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/22127014"><span id="translatedtitle">CURRENT <span class="hlt">SHEET</span> REGULATION OF SOLAR NEAR-RELATIVISTIC <span class="hlt">ELECTRON</span> INJECTION HISTORIES</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Agueda, N.; Sanahuja, B.; Vainio, R.; Dalla, S.; Lario, D.</p> <p>2013-03-10</p> <p>We present a sample of three large near-relativistic (>50 keV) <span class="hlt">electron</span> events observed in 2001 by both the ACE and the Ulysses spacecraft, when Ulysses was at high-northern latitudes (>60 Degree-Sign ) and close to 2 AU. Despite the large latitudinal distance between the two spacecraft, <span class="hlt">electrons</span> injected near the Sun reached both heliospheric locations. All three events were associated with large solar flares, strong decametric type II radio bursts and accompanied by wide (>212 Degree-Sign ) and fast (>1400 km s{sup -1}) coronal mass ejections (CMEs). We use advanced interplanetary transport simulations and make use of the directional intensities observed in situ by the spacecraft to infer the <span class="hlt">electron</span> injection profile close to the Sun and the interplanetary transport conditions at both low and high latitudes. For the three selected events, we find similar interplanetary transport conditions at different heliolatitudes for a given event, with values of the mean free path ranging from 0.04 AU to 0.27 AU. We find differences in the injection profiles inferred for each spacecraft. We investigate the role that sector boundaries of the heliospheric current <span class="hlt">sheet</span> (HCS) have on determining the characteristics of the <span class="hlt">electron</span> injection profiles. Extended injection profiles, associated with coronal shocks, are found if the magnetic footpoints of the spacecraft lay in the same magnetic sector as the associated flare, while intermittent sparse injection episodes appear when the spacecraft footpoints are in the opposite sector or a wrap in the HCS bounded the CME structure.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/334290','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/334290"><span id="translatedtitle"><span class="hlt">Plasma</span> and ion barrier for <span class="hlt">electron</span> beam spot stability</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Kwan, T.J.T.; Snell, C.M.</p> <p>1999-04-01</p> <p>The concept of a self-biased target to spatially confine the ions generated by the bombardment of intense <span class="hlt">electron</span> beams on bremsstrahlung conversion targets has been predicted by computer simulation and further verified by experiments at the Integrated Test Stand for DARHT at Los Alamos National Laboratory. This technical article reports an alternative method of containing the <span class="hlt">plasmas</span> and ions from the bremsstrahlung conversion target if the energy density of the <span class="hlt">electron</span> beam is below a certain threshold. With the proposed changes of the <span class="hlt">electron</span> beam parameters of the second axis of DARHT, the authors are able to show that a thin (0.5 mm) metallic barrier such as pure beryllium, or boron carbide with desirable thermal properties, is sufficiently transparent to the 20 MeV DARHT beam and at the same time able to confine the ions between the target and the barrier foil. The temperature rise in the foil due to energy deposited by the <span class="hlt">electron</span> beam is expected to be below the melting point of the materials for the first three pulses. More important, they have shown in their time dependent particle-in-cell simulations that the deployment of a barrier situated 1 to 2 cm away from the converter target can achieve the ion confinement needed for the stability of the <span class="hlt">electron</span> beam spot.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2011ApPhB.105..309G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011ApPhB.105..309G"><span id="translatedtitle">Laser-<span class="hlt">plasma</span> <span class="hlt">electron</span> acceleration in dielectric capillary tubes</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Genoud, G.; Cassou, K.; Wojda, F.; Ferrari, H. E.; Kamperidis, C.; Burza, M.; Persson, A.; Uhlig, J.; Kneip, S.; Mangles, S. P. D.; Lifschitz, A.; Cros, B.; Wahlström, C.-G.</p> <p>2011-11-01</p> <p><span class="hlt">Electron</span> beams and betatron X-ray radiation generated by laser wakefield acceleration in long <span class="hlt">plasma</span> targets are studied. The targets consist of hydrogen filled dielectric capillary tubes of diameter 150 to 200 microns and length 6 to 20 mm. <span class="hlt">Electron</span> beams are observed for peak laser intensities as low as 5×1017 W/cm2. It is found that the capillary collects energy outside the main peak of the focal spot and contributes to keep the beam self-focused over a distance longer than in a gas jet of similar density. This enables the pulse to evolve enough to reach the threshold for wavebreaking, and thus trap and accelerate <span class="hlt">electrons</span>. No <span class="hlt">electrons</span> were observed for capillaries of large diameter (250 ?m), confirming that the capillary influences the interaction and does not have the same behaviour as a gas cell. Finally, X-rays are used as a diagnostic of the interaction and, in particular, to estimate the position of the <span class="hlt">electrons</span> trapping point inside the capillary.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015PSST...24f5013L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015PSST...24f5013L"><span id="translatedtitle"><span class="hlt">Electron</span> dynamics and ion acceleration in expanding-<span class="hlt">plasma</span> thrusters</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Lafleur, T.; Cannat, F.; Jarrige, J.; Elias, P. Q.; Packan, D.</p> <p>2015-12-01</p> <p>In most expanding-<span class="hlt">plasma</span> thrusters, ion acceleration occurs due to the formation of ambipolar-type electric fields; a process that depends strongly on the <span class="hlt">electron</span> dynamics of the discharge. The <span class="hlt">electron</span> properties also determine the heat flux leaving the thruster as well as the maximum ion energy, which are important parameters for the evaluation of thruster performance. Here we perform an experimental and theoretical investigation with both magnetized, and unmagnetized, low-pressure thrusters to explicitly determine the relationship between the ion energy, E i , and the <span class="hlt">electron</span> temperature, T e0. With no magnetic field a relatively constant value of {{E}i}/{{T}e0}? 6 is found for xenon, while when a magnetic nozzle is present, {{E}i}/{{T}e0} is between about 4–5. These values are shown to be a function of both the magnetic field strength, as well as the <span class="hlt">electron</span> energy distribution function, which changes significantly depending on the mass flow rate (and hence neutral gas pressure) used in the thruster. The relationship between the ion energy and <span class="hlt">electron</span> temperature allows estimates to be made for polytropic indices of use in a number of fluid models, as well as estimates of the upper limits to the performance of these types of systems, which for xenon and argon result in maximum specific impulses of about 2500 s and 4500 s respectively.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1999PhPl....6..238M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1999PhPl....6..238M"><span id="translatedtitle">Energy limits on runaway <span class="hlt">electrons</span> 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>Martín-Solís, J. R.; Esposito, B.; Sánchez, R.; Alvarez, J. D.</p> <p>1999-01-01</p> <p>A test particle description of the runaway dynamics is used to analyze some of the main mechanisms limiting the runaway energy in a tokamak <span class="hlt">plasma</span>. It is found that the synchrotron radiation losses associated with the <span class="hlt">electron</span> gyromotion around the magnetic field lines can explain the energy limit of runaway <span class="hlt">electrons</span> found experimentally by observing their bremsstrahlung spectra during the current ramp-up of low density Ohmic discharges in the Joint European Torus (JET) [Nucl. Fusion 25, 1011 (1985)]. The model is applied to the problem of determining the influence of a resonance between the <span class="hlt">electron</span> gyromotion and the magnetic field ripple of the tokamak on the radiation loss and energy limits of runaway <span class="hlt">electrons</span>. The equilibrium energy at the resonance and the conditions under which the ripple mechanism can create an upper bound on the runaway energy are investigated. Predictions are discussed on the effect of the ripple resonance on the maximum energy attainable by disruption generated runaway <span class="hlt">electrons</span> in JET and the projected International Thermonuclear Experimental Reactor (ITER) [ITER EDA Agreement and Protocol 2, International Atomic Energy Agency, Vienna, 1994].</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('http://sprg.ssl.berkeley.edu/adminstuff/webpubs/2008_jgr_A07S33.pdf','EPRINT'); return false;" href="http://sprg.ssl.berkeley.edu/adminstuff/webpubs/2008_jgr_A07S33.pdf"><span id="translatedtitle"><span class="hlt">Electron</span> density estimations derived from spacecraft potential measurements on Cluster in tenuous <span class="hlt">plasma</span> regions</span></a></p> <p><a target="_blank" href="http://www.osti.gov/eprints/">E-print Network</a></p> <p>California at Berkeley, University of</p> <p></p> <p><span class="hlt">Electron</span> density estimations derived from spacecraft potential measurements on Cluster in tenuous density measurements. The spacecraft photoelectron characteristic (photoelectrons escaping to the <span class="hlt">plasma</span>. The consequences for <span class="hlt">plasma</span> density measurements are addressed. Typical examples are presented to demonstrate</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://sprg.ssl.berkeley.edu/~matt/AGUS2005/AGU_S2005.pdf','EPRINT'); return false;" href="http://sprg.ssl.berkeley.edu/~matt/AGUS2005/AGU_S2005.pdf"><span id="translatedtitle">2005 Joint Assembly SM52A-05 <span class="hlt">Electron</span> Acceleration in the</span></a></p> <p><a target="_blank" href="http://www.osti.gov/eprints/">E-print Network</a></p> <p>Fillingim, Matthew</p> <p></p> <p>2005 Joint Assembly SM52A-05 <span class="hlt">Electron</span> Acceleration in the Near Earth <span class="hlt">Plasma</span> <span class="hlt">Sheet</span> M. O. Fillingim, G. K. Parks, R. P. Lin Space Sciences Laboratory, University of California, Berkeley #12;2005 Joint motion #12;2005 Joint Assembly SM52A-05 <span class="hlt">Electron</span> Spectra in the <span class="hlt">Plasma</span> <span class="hlt">Sheet</span> ! From 10s of eV to several</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013PhRvB..88w5425H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013PhRvB..88w5425H"><span id="translatedtitle"><span class="hlt">Electronic</span> properties of mixed-phase graphene/h-BN <span class="hlt">sheets</span> using real-space pseudopotentials</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Huang, ZhaoHui; Crespi, Vincent H.; Chelikowsky, James R.</p> <p>2013-12-01</p> <p>A major challenge for applications of graphene is the creation of a tunable <span class="hlt">electronic</span> band gap. Hexagonal boron nitride has a lattice very similar to that of graphene and a much larger band gap, but B-N and C do not alloy: B-C-N materials tend to phase separate into h-BN and C domains. Quantum confinement within the finite-sized C domains of a mixed B-C-N system can create a band gap, albeit within an inhomogeneous system. Here we investigate the properties of hybrid h-BN/C <span class="hlt">sheets</span> with real-space pseudopotential density functional theory. We find that the <span class="hlt">electronic</span> properties are determined not just by geometrical confinement, but also by the bonding character at the h-BN/C interface. B-C terminated carbon regions tend to have larger gaps than N-C terminated regions, suggesting that boron-carbon bonds are more stable. We examine two series of symmetric structures that represent different kinds of confinement: a graphene dot within a h-BN background and a h-BN antidot within a graphene background. The gaps in both cases vary inversely with the size of the graphenic region, as expected, and can be fit by simple empirical expressions.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2011JGRA..116.1212M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011JGRA..116.1212M"><span id="translatedtitle">Interactions of the heliospheric current and <span class="hlt">plasma</span> <span class="hlt">sheets</span> with the bow shock: Cluster and Polar observations in the magnetosheath</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Maynard, Nelson C.; Farrugia, Charles J.; Burke, William J.; Ober, Daniel M.; Scudder, Jack D.; Mozer, Forrest S.; Russell, Christopher T.; Rème, Henri; Mouikis, Christopher; Siebert, Keith D.</p> <p>2011-01-01</p> <p>On 12 March 2001, the Polar and Cluster spacecraft were at subsolar and cusp latitudes in the dayside magnetosheath, respectively, where they monitored the passage by Earth of a large-scale planar structure containing the high-density heliospheric <span class="hlt">plasma</span> <span class="hlt">sheet</span> (HPS) and the embedded current <span class="hlt">sheet</span>. Over significant intervals, as the magnetic hole of the HPS passed Cluster and Polar, magnetic field strengths ?B? were much smaller than expected for the shocked interplanetary magnetic field. For short periods, ?B? even fell below values measured by ACE in the upstream solar wind. Within the magnetic hole the ratio of <span class="hlt">plasma</span> thermal and magnetic pressures (<span class="hlt">plasma</span> ?) was consistently >100 and exceeded 1000. A temporary increase in lag times for identifiable features in B components to propagate from the location of ACE to those of Cluster and Polar was associated with the expansion (and subsequent compression) of the magnetic field and observed low ?B?. Triangulation of the propagation velocity of these features across the four Cluster spacecraft configuration showed consistency with the measured component of ion velocity normal to the large-scale planar structure. B experienced large-amplitude wave activity, including fast magnetosonic waves. Within the low ?B? region, guiding center behavior was disrupted and ions were subject to hydrodynamic rather than magnetohydrodynamic forcing. Under the reported conditions, a significant portion of the interplanetary coupling to the magnetosphere should proceed through interaction with the low-latitude boundary layer. Data acquired during a nearly simultaneous high-latitude pass of a Defense Meteorological Satellites Program satellite are consistent with this conjecture.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://sprg.ssl.berkeley.edu/adminstuff/webpubs/2009_grl_18109.pdf','EPRINT'); return false;" href="http://sprg.ssl.berkeley.edu/adminstuff/webpubs/2009_grl_18109.pdf"><span id="translatedtitle">Tracing solar wind <span class="hlt">plasma</span> entry into the magnetosphere using ion-to-<span class="hlt">electron</span> temperature ratio</span></a></p> <p><a target="_blank" href="http://www.osti.gov/eprints/">E-print Network</a></p> <p>California at Berkeley, University of</p> <p></p> <p>. They all show that the low ion-to-<span class="hlt">electron</span> temperature ratio can be preserved as the <span class="hlt">plasma</span> entersTracing solar wind <span class="hlt">plasma</span> entry into the magnetosphere using ion-to-<span class="hlt">electron</span> temperature ratio B of a magnetic cloud at Earth on November 25, 2001. The ion- to-<span class="hlt">electron</span> temperature ratio was indeed low</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://dusty.physics.uiowa.edu/~goree/papers/sheridan_JVST_90_electron_ion_transport.pdf','EPRINT'); return false;" href="http://dusty.physics.uiowa.edu/~goree/papers/sheridan_JVST_90_electron_ion_transport.pdf"><span id="translatedtitle"><span class="hlt">Electron</span> and ion transport in magnetron <span class="hlt">plasmas</span> T. E. Sheridan, M. J. Goeckner, and J. Goree</span></a></p> <p><a target="_blank" href="http://www.osti.gov/eprints/">E-print Network</a></p> <p>Goree, John</p> <p></p> <p><span class="hlt">Electron</span> and ion transport in magnetron <span class="hlt">plasmas</span> T. E. Sheridan, M. J. Goeckner, and J. Goree; accepted 27 December 1989) We demonstrate experimentally that there is a strong link between <span class="hlt">electron</span> transport and ion transport in sputtering magnetron <span class="hlt">plasmas</span>. <span class="hlt">Electron</span> densities and discharge currents</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015BrJPh..45..409E','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015BrJPh..45..409E"><span id="translatedtitle">Nonlinear Electromagnetic Waves in a Degenerate <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-Labany, S. K.; El-Taibany, W. F.; El-Samahy, A. E.; Hafez, A. M.; Atteya, A.</p> <p>2015-08-01</p> <p>Using the reductive perturbation technique (RPT), the nonlinear propagation of magnetosonic solitary waves in an ultracold, degenerate (extremely dense) <span class="hlt">electron</span>-positron (EP) <span class="hlt">plasma</span> (containing ultracold, degenerate <span class="hlt">electron</span>, and positron fluids) is investigated. The set of basic equations is reduced to a Korteweg-de Vries (KdV) equation for the lowest-order perturbed magnetic field and to a KdV type equation for the higher-order perturbed magnetic field. The solutions of these evolution equations are obtained. For better accuracy and searching on new features, the new solutions are analyzed numerically based on compact objects (white dwarf) parameters. It is found that including the higher-order corrections results as a reduction (increment) of the fast (slow) electromagnetic wave amplitude but the wave width is increased in both cases. The ranges where the RPT can describe adequately the total magnetic field including different conditions are discussed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/21241973','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/21241973"><span id="translatedtitle"><span class="hlt">Electron</span> state density and <span class="hlt">electron</span> diffusion coefficient in energy space in nonideal nonequilibrium <span class="hlt">plasmas</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Bobrov, A. A.; Bronin, S. Ya.; Zelener, B. B. Zelener, B. V.; Manykin, E. A.</p> <p>2008-07-15</p> <p>We suggest a model for a hydrogenic low-temperature nonequilibrium nonideal <span class="hlt">plasma</span> that allows the kinetic parameters of the <span class="hlt">plasma</span> to be calculated by the method of molecular dynamics by taking into account the interparticle interaction. The charges interact according to Coulomb's law; for unlike charges, the interaction is assumed to be equal to a constant at a distance smaller than several Bohr radii. For a system of particles, we solve the classical equations of motion under periodic boundary conditions. The initial conditions are specified in such a way that the <span class="hlt">electrons</span> have a positive total energy. We consider the temperatures 1-50 K and densities n = 10{sup 9}-10{sup 10} cm{sup -3} produced in an experiment through laser cooling and resonant excitation. We calculate the <span class="hlt">electron</span> state density as a function of the <span class="hlt">plasma</span> coupling parameter and the <span class="hlt">electron</span> diffusion coefficient in energy space for highly excited (Rydberg) <span class="hlt">electron</span> states close to the boundary of the discrete and continuum spectra.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://w3.pppl.gov/~fisch/fischpapers/2011/raitses.ieee.2011.pdf','EPRINT'); return false;" href="http://w3.pppl.gov/~fisch/fischpapers/2011/raitses.ieee.2011.pdf"><span id="translatedtitle">IEEE TRANSACTIONS ON <span class="hlt">PLASMA</span> SCIENCE, VOL. 39, NO. 4, APRIL 2011 995 Effect of Secondary <span class="hlt">Electron</span> Emission on <span class="hlt">Electron</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/eprints/">E-print Network</a></p> <p></p> <p></p> <p>field and its dependence on the applied voltage and the <span class="hlt">electron</span>-induced secondary <span class="hlt">electron</span> emissionIEEE TRANSACTIONS ON <span class="hlt">PLASMA</span> SCIENCE, VOL. 39, NO. 4, APRIL 2011 995 Effect of Secondary <span class="hlt">Electron</span> Emission on <span class="hlt">Electron</span> Cross-Field Current in E × B Discharges Yevgeny Raitses, Igor D. Kaganovich, Alexander</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4612307','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4612307"><span id="translatedtitle">Effect of <span class="hlt">Electron</span> Energy Distribution on the Hysteresis of <span class="hlt">Plasma</span> Discharge: Theory, Experiment, and Modeling</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Lee, Hyo-Chang; Chung, Chin-Wook</p> <p>2015-01-01</p> <p>Hysteresis, which is the history dependence of physical systems, is one of the most important topics in physics. Interestingly, bi-stability of <span class="hlt">plasma</span> with a huge hysteresis loop has been observed in inductive <span class="hlt">plasma</span> discharges. Despite long <span class="hlt">plasma</span> research, how this <span class="hlt">plasma</span> hysteresis occurs remains an unresolved question in <span class="hlt">plasma</span> physics. Here, we report theory, experiment, and modeling of the hysteresis. It was found experimentally and theoretically that evolution of the <span class="hlt">electron</span> energy distribution (EED) makes a strong <span class="hlt">plasma</span> hysteresis. In Ramsauer and non-Ramsauer gas experiments, it was revealed that the <span class="hlt">plasma</span> hysteresis is observed only at high pressure Ramsauer gas where the EED deviates considerably from a Maxwellian shape. This hysteresis was presented in the <span class="hlt">plasma</span> balance model where the EED is considered. Because <span class="hlt">electrons</span> in <span class="hlt">plasmas</span> are usually not in a thermal equilibrium, this EED-effect can be regarded as a universal phenomenon in <span class="hlt">plasma</span> physics. PMID:26482650</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015NatSR...515254L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015NatSR...515254L"><span id="translatedtitle">Effect of <span class="hlt">Electron</span> Energy Distribution on the Hysteresis of <span class="hlt">Plasma</span> Discharge: Theory, Experiment, and Modeling</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>2015-10-01</p> <p>Hysteresis, which is the history dependence of physical systems, is one of the most important topics in physics. Interestingly, bi-stability of <span class="hlt">plasma</span> with a huge hysteresis loop has been observed in inductive <span class="hlt">plasma</span> discharges. Despite long <span class="hlt">plasma</span> research, how this <span class="hlt">plasma</span> hysteresis occurs remains an unresolved question in <span class="hlt">plasma</span> physics. Here, we report theory, experiment, and modeling of the hysteresis. It was found experimentally and theoretically that evolution of the <span class="hlt">electron</span> energy distribution (EED) makes a strong <span class="hlt">plasma</span> hysteresis. In Ramsauer and non-Ramsauer gas experiments, it was revealed that the <span class="hlt">plasma</span> hysteresis is observed only at high pressure Ramsauer gas where the EED deviates considerably from a Maxwellian shape. This hysteresis was presented in the <span class="hlt">plasma</span> balance model where the EED is considered. Because <span class="hlt">electrons</span> in <span class="hlt">plasmas</span> are usually not in a thermal equilibrium, this EED-effect can be regarded as a universal phenomenon in <span class="hlt">plasma</span> physics.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015SPIE.9543E..0ZZ','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015SPIE.9543E..0ZZ"><span id="translatedtitle">Theoretical study on the <span class="hlt">electron</span> energy distribution function and <span class="hlt">electron</span> transport parameters of argon <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>Zhang, Yachun; He, Xiang; Chen, Jianping; Lu, Jian; Ni, Xiaowu; Shen, Zhonghua</p> <p>2015-05-01</p> <p>Fluid model of argon <span class="hlt">plasma</span> require the input of transport parameters that depend on the <span class="hlt">electron</span> energy distribution function (EEDF). The EEDF and <span class="hlt">electron</span> transport parameters of reduced field and electric field frequency in argon <span class="hlt">plasma</span> are investigated by solving the Boltzmann equation with the two-term approximation. It is found that the EEDF closes to Druyvesteyn distribution and decreases sharply after several eV when the reduced field is less than 10Td. The low energy part of EEDF flats with the reduced field, and the high energy tail of EEDF increases with the reduced field. The EEDF approaches to dual temperature Maxwellian distribution when the reduced field is larger than 50Td. When the reduced field is larger than 300Td, the high energy tail of EEDF decreases more slowly than Maxwellian distribution, and the shape of EEDF tends to concave. The <span class="hlt">electron</span> mobility decreases with the reduced field, and tends to a const . The <span class="hlt">electron</span> diffusion coefficient increases with the reduced field, but exists a local minimum at 50Td. The relationship between EEDF and electric field frequency shows that the EEDF approaches to Maxwellian distribution in a high frequency field because of the collision with <span class="hlt">electrons</span> and neutral particles. In this case, the <span class="hlt">electron</span> mobility and diffusion coefficient are complex number, and the imaginary parts raise with the field frequency. The absolute value of transport parameters decrease with the field frequency.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1987SPIE..787..105C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1987SPIE..787..105C"><span id="translatedtitle"><span class="hlt">Electron</span> Temperature Measurements Of The Thermonuclear <span class="hlt">Plasma</span> In The TFTR Tokamak Using Millimeter Wave <span class="hlt">Plasma</span> Emission</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Cavallo, A.; Efthimion, P. C.; Taylor, G.; Stauffer, F. J.; McCarthy, M. P.; Cutler, R. C.</p> <p>1987-10-01</p> <p>Precision measurements of the <span class="hlt">electron</span> temperature and the <span class="hlt">electron</span> temperature fluctuations in the Tokamak Fusion Test Reactor (TFTR) (major radius 2.6 meters, minor radius 0.8 meters, ion temperature 200 million degrees, <span class="hlt">electron</span> temperature 70 million degrees) are necessary to understand the details of <span class="hlt">plasma</span> stability and energy confinement. These measurements must be made remotely since there will be high radiation levels ( 1019 neutrons/pulse, 100 rads/pulse) as well as high levels of stray radiofrequency energy (50 MHz) and time changing magnetic fields in the vicinity of the tokamak. Three different instruments are used for these studies: a fast scanning superheterodyne radiometer (0.002 sec temperature profile); a fast scanning Michelson Interferometer (0.01 sec scan); and a twenty channel grating polychrometer which monitors <span class="hlt">electron</span> temperature at twenty locations in the <span class="hlt">plasma</span> continuously. The scanning radiometer uses state of the art mixers, detectors and levelers and must be heavily shielded from stray magnetic and radiofrequency fields, but is insensitive to neutrons and x-ray radiation. The Michelson system is relatively insensitive to radiation or stray fields. The grating instrument is located outside the 1.54 meter concrete shield wall to avoid a subtle neutron-detector interaction. Because of the large n, 4He inelastic cross-section (7 barns at 1.25 MeV), the neutron flux from the tokamak can perturb the temperature of the liquid helium bath used to cool the detectors. A temperature rise of several millikelvin is equivalent to a significant fraction of the temperature signal at the edge of the <span class="hlt">plasma</span>. All three instruments may be calibrated absolutely and are designed for reliability and ease of maintenance.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/22218364','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/22218364"><span id="translatedtitle"><span class="hlt">Electron</span> self-injection in the proton-driven-<span class="hlt">plasma</span>-wakefield acceleration</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Hu, Zhang-Hu; Wang, You-Nian</p> <p>2013-12-15</p> <p>The self-injection process of <span class="hlt">plasma</span> <span class="hlt">electrons</span> in the proton-driven-<span class="hlt">plasma</span>-wakefield acceleration scheme is investigated using a two-dimensional, electromagnetic particle-in-cell method. <span class="hlt">Plasma</span> <span class="hlt">electrons</span> are self-injected into the back of the first acceleration bucket during the initial bubble formation period, where the wake phase velocity is low enough to trap sufficient <span class="hlt">electrons</span>. Most of the self-injected <span class="hlt">electrons</span> are initially located within a distance of the skin depth c/?{sub pe} to the beam axis. A decrease (or increase) in the beam radius (or length) leads to a significant reduction in the total charges of self-injected <span class="hlt">electron</span> bunch. Compared to the uniform <span class="hlt">plasma</span>, the energy spread, emittance and total charges of the self-injected bunch are reduced in the <span class="hlt">plasma</span> channel case, due to a reduced injection of <span class="hlt">plasma</span> <span class="hlt">electrons</span> that initially located further away from the beam axis.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19960008372','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19960008372"><span id="translatedtitle">Integration issues of a <span class="hlt">plasma</span> contactor Power <span class="hlt">Electronics</span> Unit</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Pinero, Luis R.; York, Kenneth W.; Bowers, Glen E.</p> <p>1995-01-01</p> <p>A hollow cathode-based <span class="hlt">plasma</span> contactor is baselined on International Space Station Alpha (ISSA) for spacecraft charge control. The <span class="hlt">plasma</span> contactor system consists of a hollow cathode assembly (HCA), a power <span class="hlt">electronics</span> unit (PEU), and an expellant management unit (EMU). The <span class="hlt">plasma</span> contactor has recently been required to operate in a cyclic mode to conserve xenon expellant and extend system life. Originally, a DC cathode heater converter was baselined for a continuous operation mode because only a few ignitions of the hollow cathode were expected. However, for cyclic operation, a DC heater supply can potentially result in hollow cathode heater component failure due to the DC electrostatic field. This can prevent the heater from attaining the proper cathode tip temperature for reliable ignition of the hollow cathode. To mitigate this problem, an AC cathode heater supply was therefore designed, fabricated, and installed into a modified PEU. The PEU was tested using resistive loads and then integrated with an engineering model hollow cathode to demonstrate stable steady-state operation. Integration issues such as the effect of line and load impedance on the output of the AC cathode heater supply and the characterization of the temperature profile of the heater under AC excitation were investigated.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://arxiv.org/pdf/1512.00744.pdf','EPRINT'); return false;" href="http://arxiv.org/pdf/1512.00744.pdf"><span id="translatedtitle">Strongly Enhanced Stimulated Brillouin Backscattering 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/eprints/">E-print Network</a></p> <p>Edwards, Matthew R; Mikhailova, Julia M</p> <p>2015-01-01</p> <p>Stimulated Brillouin backscattering of light is shown to be drastically enhanced in <span class="hlt">electron</span>-positron <span class="hlt">plasmas</span>, in contrast to the suppression of stimulated Raman scattering. A generalized theory of three-wave coupling between electromagnetic and <span class="hlt">plasma</span> waves in two-species <span class="hlt">plasmas</span> with arbitrary mass ratios, confirmed with a comprehensive set of particle-in-cell simulations, reveals violations of commonly-held assumptions about the behavior of <span class="hlt">electron</span>-positron <span class="hlt">plasmas</span>. Specifically, in the <span class="hlt">electron</span>-positron limit three-wave parametric interaction between light and the <span class="hlt">plasma</span> acoustic wave can occur, and the acoustic wave phase velocity differs from its usually assumed value.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/22218475','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/22218475"><span id="translatedtitle">Observation of <span class="hlt">plasma</span> instabilities related to dust particle growth mechanisms in <span class="hlt">electron</span> cyclotron resonance <span class="hlt">plasmas</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Drenik, A.; CNRS, LAPLACE, 31062 Toulouse Yuryev, P.; Clergereaux, R.; Margot, J.</p> <p>2013-10-15</p> <p>Instabilities are observed in the self-bias voltage measured on a probe immersed in microwave <span class="hlt">plasma</span> excited at <span class="hlt">Electron</span> Cyclotron Resonance (ECR). Observed in the MHz range, they were systematically measured in dust-free or dusty <span class="hlt">plasmas</span> (obtained for different conditions of applied microwave powers and acetylene flow rates). Two characteristic frequencies, well described as lower hybrid oscillations, can be defined. The first one, in the 60–70 MHz range, appears as a sharp peak in the frequency spectra and is observed in every case. Attributed to ions, its position shift observed with the output power highlights that nucleation process takes place in the dusty <span class="hlt">plasma</span>. Attributed to lower hybrid oscillation of powders, the second broad peak in the 10–20 MHz range leads to the characterization of dust particles growth mechanisms: in the same way as in capacitively coupled <span class="hlt">plasmas</span>, accumulation of nucleus confined near the probe in the magnetic field followed by aggregation takes place. Then, the measure of electrical instabilities on the self-bias voltage allows characterizing the discharge as well as the chemical processes that take place in the magnetic field region and their kinetics.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015ApJ...809...35K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015ApJ...809...35K"><span id="translatedtitle">Collisional Relaxation of <span class="hlt">Electrons</span> in a Warm <span class="hlt">Plasma</span> and Accelerated Nonthermal <span class="hlt">Electron</span> Spectra 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>Kontar, Eduard P.; Jeffrey, Natasha L. S.; Emslie, A. Gordon; Bian, N. H.</p> <p>2015-08-01</p> <p>Extending previous studies of nonthermal <span class="hlt">electron</span> transport in solar flares, which include the effects of collisional energy diffusion and thermalization of fast <span class="hlt">electrons</span>, we present an analytic method to infer more accurate estimates of the accelerated <span class="hlt">electron</span> spectrum in solar flares from observations of the hard X-ray spectrum. Unlike for the standard cold-target model, the spatial characteristics of the flaring region, especially the necessity to consider a finite volume of hot <span class="hlt">plasma</span> in the source, need to be taken into account in order to correctly obtain the injected <span class="hlt">electron</span> spectrum from the source-integrated <span class="hlt">electron</span> flux spectrum (a quantity straightforwardly obtained from hard X-ray observations). We show that the effect of <span class="hlt">electron</span> thermalization can be significant enough to nullify the need to introduce an ad hoc low-energy cutoff to the injected <span class="hlt">electron</span> spectrum in order to keep the injected power in non-thermal <span class="hlt">electrons</span> at a reasonable value. Rather, the suppression of the inferred low-energy end of the injected spectrum compared to that deduced from a cold-target analysis allows the inference from hard X-ray observations of a more realistic energy in injected non-thermal <span class="hlt">electrons</span> in solar flares.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/22303450','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/22303450"><span id="translatedtitle">Nonlocal control of <span class="hlt">electron</span> temperature in short direct current glow discharge <span class="hlt">plasma</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Demidov, V. I.; Kudryavtsev, A. A.; Stepanova, O. M.; Kurlyandskaya, I. P.</p> <p>2014-09-15</p> <p>To demonstrate controlling the <span class="hlt">electron</span> temperature in nonlocal <span class="hlt">plasma</span>, experiments have been performed on a short (without positive column) dc glow discharge with a cold cathode by applying different voltages to the conducting discharge wall. The experiments have been performed for low-pressure noble gas discharges. The applied voltage can modify trapping the energetic <span class="hlt">electrons</span> emitted from the cathode sheath and arising from the atomic and molecular processes in the <span class="hlt">plasma</span> within the device volume. This phenomenon results in the energetic <span class="hlt">electrons</span> heating the slow <span class="hlt">plasma</span> <span class="hlt">electrons</span>, which consequently modifies the <span class="hlt">electron</span> temperature. Furthermore, a numerical model of the discharge has demonstrated the <span class="hlt">electron</span> temperature modification for the above case.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/21537865','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/21537865"><span id="translatedtitle">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 Ring Trap 1</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Saitoh, H.; Yoshida, Z.; Morikawa, J.; Furukawa, M.; Yano, Y.; Kawai, Y.; Kobayashi, M.; Vogel, G.; Mikami, H.</p> <p>2011-05-15</p> <p>Formation of high-{beta} <span class="hlt">electron</span> cyclotron resonance heating <span class="hlt">plasma</span> and stable confinement of pure <span class="hlt">electron</span> <span class="hlt">plasma</span> have been realized in the Ring Trap 1 device, a magnetospheric configuration generated by a levitated dipole field magnet. The effects of coil levitation resulted in drastic improvements of the confinement properties, and the maximum local {beta} value has exceeded 70%. Hot <span class="hlt">electrons</span> are major component of <span class="hlt">electron</span> populations, and its particle confinement time is 0.5 s. <span class="hlt">Plasma</span> has a peaked density profile in strong field region [H. Saitoh et al., 23rd IAEA Fusion Energy Conference EXC/9-4Rb (2010)]. In pure <span class="hlt">electron</span> <span class="hlt">plasma</span> experiment, inward particle diffusion is realized, and <span class="hlt">electrons</span> are stably trapped for more than 300 s. When the <span class="hlt">plasma</span> is in turbulent state during beam injection, <span class="hlt">plasma</span> flow has a shear, which activates the diocotron (Kelvin-Helmholtz) instability. The canonical angular momentum of the particle is not conserved in this phase, realizing the radial diffusion of charged particles across closed magnetic surfaces. [Z. Yoshida et al., Phys Rev. Lett. 104, 235004 (2010); H. Saitoh et al., Phys. <span class="hlt">Plasmas</span> 17, 112111 (2010).].</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('http://ntrs.nasa.gov/search.jsp?R=19850062508&hterms=Electromagnetic+pulse&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3DElectromagnetic%2Bpulse','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19850062508&hterms=Electromagnetic+pulse&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3DElectromagnetic%2Bpulse"><span id="translatedtitle">Radiation from long pulse train <span class="hlt">electron</span> beams in space <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>Harker, K. J.; Banks, P. M.</p> <p>1985-01-01</p> <p>A previous study of electromagnetic radiation from a finite train of <span class="hlt">electron</span> pulses is extended to an infinite train of such pulses. The <span class="hlt">electrons</span> are assumed to follow an idealized helical path through a space <span class="hlt">plasma</span> in such a manner as to retain their respective position within the beam. This leads to radiation by coherent spontaneous emission. The waves of interest in this region are the whistler slow (compressional) and fast (torsional) Alfven waves. Although a general theory is developed, analysis is then restricted to two approximations, the short and long <span class="hlt">electron</span> beam. Formulas for the radiation per unit solid angle from the short beam are presented as a function of both propagation and ray angles, <span class="hlt">electron</span> beam pulse width and separation and beam current, voltage, and pitch angle. Similar formulas for the total power radiated from the long beam are derived as a function of frequency, propagation angle, and ray angle. Predictions of the power radiated are presented for representative examples as determined by the long beam theory.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/1048309','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/1048309"><span id="translatedtitle"><span class="hlt">Electron</span> Beam Charge Diagnostics for Laser <span class="hlt">Plasma</span> Accelerators</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Nakamura, Kei; Gonsalves, Anthony; Lin, Chen; Smith, Alan; Rodgers, David; Donahue, Rich; Byrne, Warren; Leemans, Wim</p> <p>2011-06-27</p> <p>A comprehensive study of charge diagnostics is conducted to verify their validity for measuring <span class="hlt">electron</span> beams produced by laser <span class="hlt">plasma</span> accelerators (LPAs). First, a scintillating screen (Lanex) was extensively studied using subnanosecond <span class="hlt">electron</span> beams from the Advanced Light Source booster synchrotron, at the Lawrence Berkeley National Laboratory. The Lanex was cross calibrated with an integrating current transformer (ICT) for up to the <span class="hlt">electron</span> energy of 1.5 GeV, and the linear response of the screen was confirmed for charge density and intensity up to 160 pC/mm{sup 2} and 0.4 pC/(ps mm{sup 2}), respectively. After the radio-frequency accelerator based cross calibration, a series of measurements was conducted using <span class="hlt">electron</span> beams from an LPA. Cross calibrations were carried out using an activation-based measurement that is immune to electromagnetic pulse noise, ICT, and Lanex. The diagnostics agreed within {+-}8%, showing that they all can provide accurate charge measurements for LPAs.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015JaJAP..54i5103O','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015JaJAP..54i5103O"><span id="translatedtitle">Improvement of device performance of polymer organic light-emitting diodes on smooth transparent <span class="hlt">sheet</span> with graphene films synthesized by <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>Okigawa, Yuki; Mizutani, Wataru; Suzuki, Kenkichi; Ishihara, Masatou; Yamada, Takatoshi; Hasegawa, Masataka</p> <p>2015-09-01</p> <p>Because graphene films have one-atom thickness, the morphology of the transparent <span class="hlt">sheets</span> could have a greater effect on the performance of organic light-emitting diode (OLED) devices with graphene films than on that with indium tin oxide (ITO). In this study, we have evaluated the polymer OLED devices with graphene films synthesized by <span class="hlt">plasma</span> treatment on poly(ethylene terephthalate) (PET) and poly(ethylene naphthalate) (PEN) <span class="hlt">sheets</span> having high flatness. The results imply that the surface roughness of the transparent <span class="hlt">sheets</span> predominantly affects the luminescence of polymer OLED devices with graphene films. The suppression of leakage current and a luminescence higher than 8000 cd/m2 at 15 V were attained for the devices on the transparent <span class="hlt">sheet</span> with higher flatness in spite of the presence of large sharp spikes.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/22252101','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/22252101"><span id="translatedtitle">Effects of initially energetic <span class="hlt">electrons</span> on relativistic laser-driven <span class="hlt">electron</span> <span class="hlt">plasma</span> waves</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Yazdanpanah, J. Anvari, A.</p> <p>2014-02-15</p> <p>In this paper, using kinetic calculations and accurate 1D2V particle-in-cell simulations, we point out the important role of initially energetic <span class="hlt">electrons</span> of the distribution tail in the behavior of high amplitude <span class="hlt">electron</span> <span class="hlt">plasma</span> waves (EPWs). In the presence of these <span class="hlt">electrons</span>, the conventional warm fluid theory (WFT) breaks at very high wave amplitudes that are still noticeably lower than the wave breaking amplitude (WBA). The fluid breakdown results in <span class="hlt">electron</span> super-heating with respect to the adiabatic laws. Indeed, a new kinetic regime of the relativistic EPWs appears below the WBA. It is argued that the mentioned super-heating results in WBA values lower than the corresponding WFT prediction.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/22350937','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/22350937"><span id="translatedtitle">Coherent kilo-<span class="hlt">electron</span>-volt backscattering from <span class="hlt">plasma</span>-wave boosted relativistic <span class="hlt">electron</span> mirrors</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Li, F. Y.; Chen, M. Liu, Y.; Zhang, J.; Sheng, Z. M. E-mail: zmsheng@sjtu.edu.cn; Wu, H. C.; Meyer-ter-Vehn, J.; Mori, W. B.</p> <p>2014-10-20</p> <p>A different parameter regime of laser wakefield acceleration driven by sub-petawatt femtosecond lasers is proposed, which enables the generation of relativistic <span class="hlt">electron</span> mirrors further accelerated by the <span class="hlt">plasma</span> wave. Integrated particle-in-cell simulation, including both the mirror formation and Thomson scattering, demonstrates that efficient coherent backscattering up to keV photon energy can be obtained with moderate driving laser intensities and high density gas targets.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/936946','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/936946"><span id="translatedtitle">Thomson scattering from near-solid density <span class="hlt">plasmas</span> using soft x-ray free <span class="hlt">electron</span> lasers</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Holl, A; Bornath, T; Cao, L; Doppner, T; Dusterer, S; Forster, E; Fortmann, C; Glenzer, S H; Gregori, G; Laarmann, T; Meiwes-Broer, K H; Przystawik, A; Radcliffe, P; Redmer, R; Reinholz, H; Ropke, G; Thiele, R; Tiggesbaumker, J; Toleikis, S; Truong, N X; Tschentscher, T; Uschmann, I; Zastrau, U</p> <p>2006-11-21</p> <p>We propose a collective Thomson scattering experiment at the VUV free <span class="hlt">electron</span> laser facility at DESY (FLASH) which aims to diagnose warm dense matter at near-solid density. The <span class="hlt">plasma</span> region of interest marks the transition from an ideal <span class="hlt">plasma</span> to a correlated and degenerate many-particle system and is of current interest, e.g. in ICF experiments or laboratory astrophysics. <span class="hlt">Plasma</span> diagnostic of such <span class="hlt">plasmas</span> is a longstanding issue. The collective <span class="hlt">electron</span> <span class="hlt">plasma</span> mode (plasmon) is revealed in a pump-probe scattering experiment using the high-brilliant radiation to probe the <span class="hlt">plasma</span>. The distinctive scattering features allow to infer basic <span class="hlt">plasma</span> properties. For <span class="hlt">plasmas</span> in thermal equilibrium the <span class="hlt">electron</span> density and temperature is determined from scattering off the plasmon mode.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://sprg.ssl.berkeley.edu/adminstuff/webpubs/2008_jgr_A02205.pdf','EPRINT'); return false;" href="http://sprg.ssl.berkeley.edu/adminstuff/webpubs/2008_jgr_A02205.pdf"><span id="translatedtitle">Two classes of earthward fast flows in the <span class="hlt">plasma</span> <span class="hlt">sheet</span> J.-H. Shue,1</span></a></p> <p><a target="_blank" href="http://www.osti.gov/eprints/">E-print Network</a></p> <p>California at Berkeley, University of</p> <p></p> <p>rates for most of the earthward fast flows in Class II are low. The auroral features, such as poleward of VxBz > 2 mV/m for an identification of fast flows, where Vx is the X component of the <span class="hlt">plasma</span> flow of <span class="hlt">plasma</span> and magnetic fields in the near-Earth region vary in response to changing solar wind conditions</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://arxiv.org/pdf/astro-ph/0307456v1','EPRINT'); return false;" href="http://arxiv.org/pdf/astro-ph/0307456v1"><span id="translatedtitle">Charge separation effects in magnetized <span class="hlt">electron</span>-ion <span class="hlt">plasma</span> expansion into a vacuum</span></a></p> <p><a target="_blank" href="http://www.osti.gov/eprints/">E-print Network</a></p> <p>Kazumi Nishimura; Edison Liang; S. Peter Gary</p> <p>2003-07-25</p> <p>Charge separation effects in the expansion of magnetized relativistic <span class="hlt">electron</span>-ion <span class="hlt">plasmas</span> into a vacuum are examined using 2-1/2-dimensional particle-in-cell <span class="hlt">plasma</span> simulations. The electrostatic field at the <span class="hlt">plasma</span> surface decelerates <span class="hlt">electrons</span> and accelerates ions. A fraction of the surface <span class="hlt">electrons</span> are trapped and accelerated by the pondermotive force of the propagating electromagnetic pulse, a mechanism we call the DRPA (diamagnetic relativistic pulse accelerator). This charge separation is enhanced as the initial <span class="hlt">plasma</span> temperature is decreased. The overall energy gain of the <span class="hlt">plasma</span> particles through the expansion strongly depends on the initial <span class="hlt">plasma</span> temperature. Moreover, the <span class="hlt">electrons</span> become relatively less energized and the ions more energized as the <span class="hlt">plasma</span> temperature decreases.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/160783','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/160783"><span id="translatedtitle"><span class="hlt">Electron</span> beam-<span class="hlt">plasma</span> interaction experiments with the Versatile Toroidal Facility (VTF)</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Murphy, S.M.; Lee, M.C.; Moriarty, D.T.; Riddolls, R.J.</p> <p>1995-12-31</p> <p>The laboratory investigation of <span class="hlt">electron</span> beam-<span class="hlt">plasma</span> interactions is motivated by the recent space shuttle experiments. Interesting but puzzling phenomena were observed in the shuttle experiments such as the bulk heating of background ionospheric <span class="hlt">plasmas</span> by the injected <span class="hlt">electron</span> beams and the excitation of <span class="hlt">plasma</span> waves in the frequency range of ELF waves. The <span class="hlt">plasma</span> machine, the Versatile Toroidal Facility (VTF) can generate a large magnetized <span class="hlt">plasma</span> with the <span class="hlt">electron</span> <span class="hlt">plasma</span> frequency greater than the <span class="hlt">electron</span> gyrofrequency by a factor of 3--5 similar to the <span class="hlt">plasma</span> condition in the ionosphere. Short pulses of <span class="hlt">electron</span> beams are injected into the VTF <span class="hlt">plasmas</span> in order to simulate the beam injection from spacecrafts in the ionosphere. A Langmuir probe installed at a bottom port of VTF monitors the spatial variation of <span class="hlt">electron</span> beams emitted from LaB6 filaments. An energy analyzer has been used to determine the particle energy distribution in the VTF <span class="hlt">plasmas</span>. Several mechanisms will be tested as potential causes of the bulk heating of background <span class="hlt">plasmas</span> by the injected <span class="hlt">electron</span> beams as seen in the space shuttle experiments. It is speculated that the observed ELF emissions result from the excitation of purely growing modes detected by the space shuttle-borne detectors. Results of the laboratory experiments will be reported to corroborate this speculation.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19850046914&hterms=electromagnetic+radiation&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3D%2528electromagnetic%2Bradiation%2529','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19850046914&hterms=electromagnetic+radiation&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3D%2528electromagnetic%2Bradiation%2529"><span id="translatedtitle">Electromagnetic radiation and nonlinear energy flow in an <span class="hlt">electron</span> beam-<span class="hlt">plasma</span> system</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Whelan, D. A.; Stenzel, R. L.</p> <p>1985-01-01</p> <p>It is shown that the unstable <span class="hlt">electron-plasma</span> waves of a beam-<span class="hlt">plasma</span> system can generate electromagnetic radiation in a uniform <span class="hlt">plasma</span>. The generation mechanism is a scattering of the unstable <span class="hlt">electron</span> <span class="hlt">plasma</span> waves off ion-acoustic waves, producing electromagnetic waves whose frequency is near the local <span class="hlt">plasma</span> frequency. The wave vector and frequency matching conditions of the three-wave mode coupling are experimentally verified. The electromagnetic radiation is observed to be polarized with the electric field parallel to the beam direction, and its source region is shown to be localized to the unstable <span class="hlt">plasma</span> wave region. The frequency spectrum shows negligible intensity near the second harmonic of the <span class="hlt">plasma</span> frequency. These results suggest that the observed electromagnetic radiation of type III solar bursts may be generated near the local <span class="hlt">plasma</span> frequency and observed downstream where the wave frequency is near the harmonic of the <span class="hlt">plasma</span> frequency.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/22039038','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/22039038"><span id="translatedtitle">Characteristics of InGaP/InGaAs pseudomorphic high <span class="hlt">electron</span> mobility transistors with triple delta-doped <span class="hlt">sheets</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Chu, Kuei-Yi; Chiang, Meng-Hsueh Cheng, Shiou-Ying; Liu, Wen-Chau</p> <p>2012-02-15</p> <p>Fundamental and insightful characteristics of InGaP/InGaAs double channel pseudomorphic high <span class="hlt">electron</span> mobility transistors (DCPHEMTs) with graded and uniform triple {delta}-doped <span class="hlt">sheets</span> are coomprehensively studied and demonstrated. To gain physical insight, band diagrams, carrier densities, and direct current characteristics of devices are compared and investigated based on the 2D semiconductor simulator, Atlas. Due to uniform carrier distribution and high <span class="hlt">electron</span> density in the double InGaAs channel, the DCPHEMT with graded triple {delta}-doped <span class="hlt">sheets</span> exhibits better transport properties, higher and linear transconductance, and better drain current capability as compared with the uniformly triple {delta}-doped counterpart. The DCPHEMT with graded triple {delta}-doped structure is fabricated and tested, and the experimental data are found to be in good agreement with simulated results.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015EPJAP..7031301T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015EPJAP..7031301T"><span id="translatedtitle">Stability, <span class="hlt">electronic</span> and magnetic properties of Co-anchored on graphene <span class="hlt">sheets</span> towards S, SH and H2S molecules</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Tang, Yanan; Liu, Zhiyong; Chen, Weiguang; Fu, Zhaoming; Li, Wei; Dai, Xianqi</p> <p>2015-06-01</p> <p>The adsorption behaviors of H2S and its intermediates (SH and S) on Co anchored graphene <span class="hlt">sheets</span> (Co-graphene) are investigated using first-principles calculations based density functional theory. It is found that the adsorbed SH and S species on the Co-graphene <span class="hlt">sheets</span> are more stable than that of the H2S molecule. Besides, the chemisorbed SH and S species on the Co-graphene can lead to dramatic changes in the <span class="hlt">electronic</span> structure and magnetic property by the occurring charge transfer. The <span class="hlt">electronic</span> transport behaviors of Co-graphene nanosheets indicate that the chemical sensors construct with the materials could exhibit high sensitivity for detecting SH and S species. Therefore, these results provide valuable guidance on designing graphene-based gas sensors.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015JGRA..120.1957Y','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015JGRA..120.1957Y"><span id="translatedtitle">A 2-D empirical <span class="hlt">plasma</span> <span class="hlt">sheet</span> pressure model for substorm growth phase using the Support Vector Regression Machine</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Yue, Chao; Wang, Chih-Ping; Lyons, Larry; Wang, Yongli; Hsu, Tung-Shin; Henderson, Michael; Angelopoulos, Vassilis; Lui, A. T. Y.; Nagai, Tsugunobu</p> <p>2015-03-01</p> <p>The <span class="hlt">plasma</span> <span class="hlt">sheet</span> pressure and its spatial structure during the substorm growth phase are crucial to understanding the development and initiation of substorms. In this paper, we first statistically analyzed the growth phase pressures using Geotail and Time History of Events and Macroscale Interactions during Substorms data and identified that solar wind dynamic pressure (PSW), energy loading, and sunspot number as the three primary factors controlling the growth phase pressure change. We then constructed a 2-D equatorial empirical pressure model and an error model within r ? 20 RE using the Support Vector Regression Machine with the three factors as input. The model predicts the <span class="hlt">plasma</span> <span class="hlt">sheet</span> pressure accurately with median errors of 5%, and predicted pressure gradients agree reasonably well with observed gradients obtained from two-probe measurements. The model shows that pressure increases linearly as PSW increases, and the PSW effect is stronger under lower energy loading. However, the pressure responses to energy loading and sunspot number are nonlinear. The pressure increases first with increasing loading or sunspot number, then remains relatively constant after reaching a peak value at ~8000 kV min loading or sunspot number of ~80. The loading effect is stronger when PSW is lower and the pressure variations are stronger near midnight than away from midnight. The sunspot number effect is clearer at smaller r. The pressure model can also be applied to understand the pressure changes observed during a substorm event by providing evaluations of the effects of energy loading and PSW, as well as the temporal and spatial effects along the spacecraft trajectory.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20110005665','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20110005665"><span id="translatedtitle">Modeling of the Convection and Interaction of Ring Current, Plasmaspheric and <span class="hlt">Plasma</span> <span class="hlt">Sheet</span> <span class="hlt">Plasmas</span> in the Inner Magnetosphere</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Fok, Mei-Ching; Chen, Sheng-Hsien; Buzulukova, Natalia; Glocer, Alex</p> <p>2010-01-01</p> <p>Distinctive sources of ions reside in the plasmasphere, plasmasheet, and ring current regions at discrete energies constitute the major <span class="hlt">plasma</span> populations in the inner/middle magnetosphere. They contribute to the electrodynamics of the ionosphere-magnetosphere system as important carriers of the global current system, in triggering; geomagnetic storm and substorms, as well as critical components of <span class="hlt">plasma</span> instabilities such as reconnection and Kelvin-Helmholtz instability at the magnetospheric boundaries. Our preliminary analysis of in-situ measurements shoves the complexity of the <span class="hlt">plasmas</span> pitch angle distributions at particularly the cold and warm <span class="hlt">plasmas</span>, vary dramatically at different local times and radial distances from the Earth in response to changes in solar wind condition and Dst index. Using an MHD-ring current coupled code, we model the convection and interaction of cold, warm and energetic ions of plasmaspheric, plasmasheet, and ring current origins in the inner magnetosphere. We compare our simulation results with in-situ and remotely sensed measurements from recent instrumentation on Geotail, Cluster, THEMIS, and TWINS spacecraft.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://geddes.lbl.gov/papers/plateau%20geddes%20etal,%20wavefront%20sensor%20electon%20density%20RSI%202010.pdf','EPRINT'); return false;" href="http://geddes.lbl.gov/papers/plateau%20geddes%20etal,%20wavefront%20sensor%20electon%20density%20RSI%202010.pdf"><span id="translatedtitle">Wavefront-sensor-based <span class="hlt">electron</span> density measurements for laser-<span class="hlt">plasma</span> accelerators</span></a></p> <p><a target="_blank" href="http://www.osti.gov/eprints/">E-print Network</a></p> <p>Geddes, Cameron Guy Robinson</p> <p></p> <p>Wavefront-sensor-based <span class="hlt">electron</span> density measurements for laser-<span class="hlt">plasma</span> accelerators G. R. Plateau wavelength and hence on the <span class="hlt">electron</span> density. Density measurements using a conventional folded density measurements are conventionally per- formed using nonperturbative laser interferometric tech</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015PhPl...22j4501D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015PhPl...22j4501D"><span id="translatedtitle">Measurements of low-energy <span class="hlt">electron</span> reflection at a <span class="hlt">plasma</span> boundary</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.; Kaganovich, I. D.; Koepke, M. E.; Kurlyandskaya, I. P.</p> <p>2015-10-01</p> <p>It is demonstrated that low-energy (<3 eV) <span class="hlt">electron</span> reflection from a solid surface in contact with a low-temperature <span class="hlt">plasma</span> can have significant variation with time. An uncontaminated, i.e., "clean," metallic surface (just after heating up to glow) in a <span class="hlt">plasma</span> environment may have practically no reflection of low-energy incident <span class="hlt">electrons</span>. However, a contaminated, i.e., "dirty," surface (in some time after cleaning by heating) that has a few monolayers of absorbent can reflect low-energy incident <span class="hlt">electrons</span> and therefore significantly affect the net <span class="hlt">electron</span> current collected by the surface. This effect may significantly change <span class="hlt">plasma</span> properties and should be taken into account in <span class="hlt">plasma</span> experiments and models. A diagnostic method is demonstrated for measurements of low-energy <span class="hlt">electron</span> absorption coefficient in <span class="hlt">plasmas</span> with a mono-energetic <span class="hlt">electron</span> group.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012PlST...14...89D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012PlST...14...89D"><span id="translatedtitle">Numerical Simulation of the Self-Heating Effect Induced by <span class="hlt">Electron</span> Beam <span class="hlt">Plasma</span> in Atmosphere</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Deng, Yongfeng; Tan, Chang; Han, Xianwei; Tan, Yonghua</p> <p>2012-02-01</p> <p>For exploiting advantages of <span class="hlt">electron</span> beam air <span class="hlt">plasma</span> in some unusual applications, a Monte Carlo (MC) model coupled with heat transfer model is established to simulate the characteristics of <span class="hlt">electron</span> beam air <span class="hlt">plasma</span> by considering the self-heating effect. Based on the model, the <span class="hlt">electron</span> beam induced temperature field and the related <span class="hlt">plasma</span> properties are investigated. The results indicate that a nonuniform temperature field is formed in the <span class="hlt">electron</span> beam <span class="hlt">plasma</span> region and the average temperature is of the order of 600 K. Moreover, much larger volume pear-shaped <span class="hlt">electron</span> beam <span class="hlt">plasma</span> is produced in hot state rather than in cold state. The beam ranges can, with beam energies of 75 keV and 80 keV, exceed 1.0 m and 1.2 m in air at pressure of 100 torr, respectively. Finally, a well verified formula is obtained for calculating the range of high energy <span class="hlt">electron</span> beam in atmosphere.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/15457251','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/15457251"><span id="translatedtitle">Monoenergetic beams of relativistic <span class="hlt">electrons</span> from intense laser-<span class="hlt">plasma</span> interactions.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Mangles, S P D; Murphy, C D; Najmudin, Z; Thomas, A G R; Collier, J L; Dangor, A E; Divall, E J; Foster, P S; Gallacher, J G; Hooker, C J; Jaroszynski, D A; Langley, A J; Mori, W B; Norreys, P A; Tsung, F S; Viskup, R; Walton, B R; Krushelnick, K</p> <p>2004-09-30</p> <p>High-power lasers that fit into a university-scale laboratory can now reach focused intensities of more than 10(19) W cm(-2) at high repetition rates. Such lasers are capable of producing beams of energetic <span class="hlt">electrons</span>, protons and gamma-rays. Relativistic <span class="hlt">electrons</span> are generated through the breaking of large-amplitude relativistic <span class="hlt">plasma</span> waves created in the wake of the laser pulse as it propagates through a <span class="hlt">plasma</span>, or through a direct interaction between the laser field and the <span class="hlt">electrons</span> in the <span class="hlt">plasma</span>. However, the <span class="hlt">electron</span> beams produced from previous laser-<span class="hlt">plasma</span> experiments have a large energy spread, limiting their use for potential applications. Here we report high-resolution energy measurements of the <span class="hlt">electron</span> beams produced from intense laser-<span class="hlt">plasma</span> interactions, showing that--under particular <span class="hlt">plasma</span> conditions--it is possible to generate beams of relativistic <span class="hlt">electrons</span> with low divergence and a small energy spread (less than three per cent). The monoenergetic features were observed in the <span class="hlt">electron</span> energy spectrum for <span class="hlt">plasma</span> densities just above a threshold required for breaking of the <span class="hlt">plasma</span> wave. These features were observed consistently in the <span class="hlt">electron</span> spectrum, although the energy of the beam was observed to vary from shot to shot. If the issue of energy reproducibility can be addressed, it should be possible to generate ultrashort monoenergetic <span class="hlt">electron</span> bunches of tunable energy, holding great promise for the future development of 'table-top' particle accelerators. PMID:15457251</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19930055360&hterms=electron&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DTitle%26N%3D0%26No%3D20%26Ntt%3Delectron','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19930055360&hterms=electron&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DTitle%26N%3D0%26No%3D20%26Ntt%3Delectron"><span id="translatedtitle">Reduction of <span class="hlt">plasma</span> <span class="hlt">electron</span> density in a gas ionized by an <span class="hlt">electron</span> beam - Use of a gaseous dielectric</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Reid, Max B.</p> <p>1993-01-01</p> <p>Propagation of an <span class="hlt">electron</span> beam through a gas creates a secondary <span class="hlt">electron</span>/ion <span class="hlt">plasma</span> which can have subsequent deleterious effects on the propagation of the beam. In the case of pulsed <span class="hlt">electron</span> beams with short micropulse durations, these effects can be greatly reduced through the use of a small doping fraction of an <span class="hlt">electron</span> attachment gas. We present a model which allows the calculation of the reduction in unbound <span class="hlt">plasma</span> <span class="hlt">electron</span> density attainable with a gaseous dielectric dopant. Potential problems with a dopant, including increased ionization, increased scattering, altered refractive index, and dopant saturation and fragmentation, are discussed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015Ap%26SS.357...36R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015Ap%26SS.357...36R"><span id="translatedtitle">Positron-acoustic solitary waves in a magnetized <span class="hlt">electron</span>-positron-ion <span class="hlt">plasma</span> with nonthermal <span class="hlt">electrons</span> and positrons</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Rahman, M. M.; Alam, M. S.; Mamun, A. A.</p> <p>2015-05-01</p> <p>Obliquely propagating positron-acoustic solitary waves (PASWs) in a magnetized <span class="hlt">electron</span>-positron-ion <span class="hlt">plasma</span> (containing nonthermal hot positrons and <span class="hlt">electrons</span>, inertial cold positrons, and immobile positive ions) are precisely investigated by deriving the Zakharov-Kuznetsov equation. It is found that the characteristics of the PASWs are significantly modified by the effects of external magnetic field, obliqueness, nonthermality of hot positrons and <span class="hlt">electrons</span>, temperature ratio of hot positrons and <span class="hlt">electrons</span>, and respective number densities of hot positrons and <span class="hlt">electrons</span>. The findings of our results can be employed in understanding the localized electrostatic structures and the characteristics of PASWs in various space and laboratory <span class="hlt">plasmas</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_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><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_25 --> <center> <div class="footer-extlink text-muted"><small>Some links on this page may take you to non-federal websites. 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