Science.gov

Sample records for absolute charge state

  1. Absolute charge calibration of scintillating screens for relativistic electron detection

    SciTech Connect

    Buck, A.; Popp, A.; Schmid, K.; Karsch, S.; Krausz, F.; Zeil, K.; Jochmann, A.; Kraft, S. D.; Sauerbrey, R.; Cowan, T.; Schramm, U.; Hidding, B.; Kudyakov, T.; Sears, C. M. S.; Veisz, L.; Pawelke, J.

    2010-03-15

    We report on new charge calibrations and linearity tests with high-dynamic range for eight different scintillating screens typically used for the detection of relativistic electrons from laser-plasma based acceleration schemes. The absolute charge calibration was done with picosecond electron bunches at the ELBE linear accelerator in Dresden. The lower detection limit in our setup for the most sensitive scintillating screen (KODAK Biomax MS) was 10 fC/mm{sup 2}. The screens showed a linear photon-to-charge dependency over several orders of magnitude. An onset of saturation effects starting around 10-100 pC/mm{sup 2} was found for some of the screens. Additionally, a constant light source was employed as a luminosity reference to simplify the transfer of a one-time absolute calibration to different experimental setups.

  2. Absolute charge calibration of scintillating screens for relativistic electron detection

    NASA Astrophysics Data System (ADS)

    Buck, A.; Zeil, K.; Popp, A.; Schmid, K.; Jochmann, A.; Kraft, S. D.; Hidding, B.; Kudyakov, T.; Sears, C. M. S.; Veisz, L.; Karsch, S.; Pawelke, J.; Sauerbrey, R.; Cowan, T.; Krausz, F.; Schramm, U.

    2010-03-01

    We report on new charge calibrations and linearity tests with high-dynamic range for eight different scintillating screens typically used for the detection of relativistic electrons from laser-plasma based acceleration schemes. The absolute charge calibration was done with picosecond electron bunches at the ELBE linear accelerator in Dresden. The lower detection limit in our setup for the most sensitive scintillating screen (KODAK Biomax MS) was 10 fC/mm2. The screens showed a linear photon-to-charge dependency over several orders of magnitude. An onset of saturation effects starting around 10-100 pC/mm2 was found for some of the screens. Additionally, a constant light source was employed as a luminosity reference to simplify the transfer of a one-time absolute calibration to different experimental setups.

  3. 47 CFR 64.1160 - Absolution procedures where the subscriber has not paid charges.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 47 Telecommunication 3 2010-10-01 2010-10-01 false Absolution procedures where the subscriber has... Preferred Telecommunications Service Providers § 64.1160 Absolution procedures where the subscriber has not paid charges. (a) This section shall only apply after a subscriber has determined that an...

  4. Low-charge-state linac

    SciTech Connect

    Shepard, K.W.; Kim, J.W.

    1995-08-01

    A design is being developed for a low-charge-state linac suitable for injecting ATLAS with a low-charge-state, radioactive beam. Initial work indicates that the existing ATLAS interdigital superconducting accelerating structures, together with the superconducting quadrupole transverse focussing element discussed above, provides a basis for a high-performance low-charge-state linac. The initial 2 or 3 MV of such a linac could be based on a normally-conducting, low-frequency RFQ, possibly combined with 24-MHz superconducting interdigital structures. Beam dynamics studies of the whole low-charge-state post-accelerator section were carried out in early FY 1995.

  5. State-of-charge coulometer

    NASA Technical Reports Server (NTRS)

    Rowlette, J. J. (Inventor)

    1985-01-01

    A coulometer for accurately measuring the state-of-charge of an open-cell battery utilizing an aqueous electrolyte, includes a current meter for measuring the battery/discharge current and a flow meter for measuring the rate at which the battery produces gas during charge and discharge. Coupled to the flow meter is gas analyzer which measures the oxygen fraction of the battery gas. The outputs of the current meter, flow meter, and gas analyzer are coupled to a programmed microcomputer which includes a CPU and program and data memories. The microcomputer calculates that fraction of charge and discharge current consumed in the generation of gas so that the actual state-of-charge can be determined. The state-of-charge is then shown on a visual display.

  6. Battery-Charge-State Model

    NASA Technical Reports Server (NTRS)

    Vivian, H. C.

    1985-01-01

    Charge-state model for lead/acid batteries proposed as part of effort to make equivalent of fuel gage for battery-powered vehicles. Models based on equations that approximate observable characteristics of battery electrochemistry. Uses linear equations, easier to simulate on computer, and gives smooth transitions between charge, discharge, and recuperation.

  7. Absolute calibration of a charge-coupled device camera with twin beams

    SciTech Connect

    Meda, A.; Ruo-Berchera, I. Degiovanni, I. P.; Brida, G.; Rastello, M. L.; Genovese, M.

    2014-09-08

    We report on the absolute calibration of a Charge-Coupled Device (CCD) camera by exploiting quantum correlation. This method exploits a certain number of spatial pairwise quantum correlated modes produced by spontaneous parametric-down-conversion. We develop a measurement model accounting for all the uncertainty contributions, and we reach the relative uncertainty of 0.3% in low photon flux regime. This represents a significant step forward for the characterization of (scientific) CCDs used in mesoscopic light regime.

  8. State estimation and absolute image registration for geosynchronous satellites

    NASA Technical Reports Server (NTRS)

    Nankervis, R.; Koch, D. W.; Sielski, H.

    1980-01-01

    Spacecraft state estimation and the absolute registration of Earth images acquired by cameras onboard geosynchronous satellites are described. The basic data type of the procedure consists of line and element numbers of image points called landmarks whose geodetic coordinates, relative to United States Geodetic Survey topographic maps, are known. A conventional least squares process is used to estimate navigational parameters and camera pointing biases from observed minus computed landmark line and element numbers. These estimated parameters along with orbit and attitude dynamic models are used to register images, using an automated grey level correlation technique, inside the span represented by the landmark data. In addition, the dynamic models can be employed to register images outside of the data span in a near real time mode. An important application of this mode is in support of meteorological studies where rapid data reduction is required for the rapid tracking and predicting of dynamic phenomena.

  9. High-charge-state ion sources

    SciTech Connect

    Clark, D.J.

    1983-06-01

    Sources of high charge state positive ions have uses in a variety of research fields. For heavy ion particle accelerators higher charge state particles give greater acceleration per gap and greater bending strength in a magnet. Thus higher energies can be obtained from circular accelerators of a given size, and linear accelerators can be designed with higher energy gain per length using higher charge state ions. In atomic physics the many atomic transitions in highly charged ions supplies a wealth of spectroscopy data. High charge state ion beams are also used for charge exchange and crossed beam experiments. High charge state ion sources are reviewed. (WHK)

  10. Determination of relative and absolute photoionization cross-sections in multiply-charged Ba^n+ Ions

    NASA Astrophysics Data System (ADS)

    Bizau, J.-M.; Cubaynes, D.; Esteva, J. M.; Wuilleumier, F. J.; Marmoret, R.; Petrault, L.; Remond, C.; Couillaud, C.; Compant La Fontaine, A.; Blancard, C.; Hitz, D.; Ludwig, P.; Deshmukh, P. C.; Zhou, H.-L.; Manson, S. T.

    2001-05-01

    Following our first photoionization measurements for the multiply-charged Xe^n+ [1] and Ba^2+ [2] ions, we introduced several modifications in the experimental set-up to allow us to measure absolute cross sections for multiply-charged ions. Photoionization studies of barium ions up to Ba^6+ were performed using synchrotron radiation emitted by an undulator of the Super ACO storage ring in Orsay and an ECR ion source. Collapse of the 4f (ɛ f) orbitals has been observed to occur faster than for Xe^n+: the relative intensity of transitions to continuum states is negligible already for Ba^3+ ions, discrete transitions to 4d^95s^25p^mnf states then dominating the measured spectra. The experimental results are in good agreement with the results of MCDF calculations for the discrete transitions and, in Ba^2+, with RRPA calculations for transitions to continuum states. 1. J.-M. Bizau et al., Phys. Rev. Lett. 84, 435 (2000). 2. J.-M. Bizau et al., Bull. Am. Phys. Soc. 45, 61 (2000).

  11. Ultrafast Measurement Confirms Charge Generation through Cold Charge Transfer States

    NASA Astrophysics Data System (ADS)

    Gautam, Bhoj; Younts, Robert; Yan, Liang; Danilov, Evgeny; Ade, Harald; You, Wei; Gundogdu, Kenan

    2015-03-01

    The role of excess energy in generation and extraction of charges through charge transfer (CT) states in polymer solar cells is a subject of debate. There are reports suggesting increase of charge generation yield with excess energy based on ultrafast experiments. On the other hand time delayed collection field measurements shows that excess photon energy has no effect in photovoltaic efficiency. Here we resolved this discrepancy by studying the dynamics of CT excitons and polarons in blends of medium gap copolymers. We found that low-lying charge transfer (CT) excitons can generate charges over a long time period (nanosecond) and contribute photocurrent on the bulk heterojunction devices. By performing resonant CT excitation as well as above gap excitation transient absorption measurements we investigated that the charges are generated more efficiently through low-lying CT states in efficient devices independent of excitation energy. This work is supported by Office of Naval Research Grant N000141310526 P00002.

  12. Charge state manipulation of qubits in diamond

    PubMed Central

    Grotz, Bernhard; Hauf, Moritz V.; Dankerl, Markus; Naydenov, Boris; Pezzagna, Sébastien; Meijer, Jan; Jelezko, Fedor; Wrachtrup, Jörg; Stutzmann, Martin; Reinhard, Friedemann; Garrido, Jose A.

    2012-01-01

    The nitrogen-vacancy (NV) centre in diamond is a promising candidate for a solid-state qubit. However, its charge state is known to be unstable, discharging from the qubit state NV− into the neutral state NV0 under various circumstances. Here we demonstrate that the charge state can be controlled by an electrolytic gate electrode. This way, single centres can be switched from an unknown non-fluorescent state into the neutral charge state NV0, and the population of an ensemble of centres can be shifted from NV0 to NV−. Numerical simulations confirm the manipulation of the charge state to be induced by the gate-controlled shift of the Fermi level at the diamond surface. This result opens the way to a dynamic control of transitions between charge states and to explore hitherto inaccessible states, such as NV+. PMID:22395620

  13. Measured Absolute Cross Section of Charge Transfer in H + H2+ at Low Energy: Signature of vi = 2 and Trajectory Effects

    NASA Astrophysics Data System (ADS)

    Strom, R. A.; Bacani, K. G.; Chi, R. M.; Heczko, S. L.; Singh, B. N.; Tobar, J. A.; Vassantachart, A. K.; Andrianarijaona, V. M.; Seely, D. G.; Havener, C. C.

    2015-04-01

    Measurements of absolute cross sections of charge transfer (CT) in H + H2+--> H+ + H2 were conducted at the merged-beam apparatus at Oak Ridge National Laboratory (ORNL) in Oak Ridge, Tennessee, which can reliably create and access collision energies as low as 0.1 eV/u. The measured absolute cross section shows evidence of trajectory effects at low energy. Also, the comparison to state-to-state calculations (PRA 67 022708 (2003) suggests a strong contribution from vi = 2 of the H2+that are produced by the electron cyclotron resonance ion source. The data analysis will be presented here. Research supported by the NASA Solar & Heliospheric Physics Program NNH07ZDA001N, the Office of Fusion Energy Sciences and the Division of Chemical Sciences, Geosciences, and Biosciences, Office of Basic Energy Sciences of the U.S. Department of Energy, the National Science Foundation through Grant No. PHY-1068877.

  14. Low-charge-state RFQ injector

    SciTech Connect

    Shepard, K.W.; Kim, J.W.

    1995-08-01

    Preliminary design work was done for a short, normally-conducting RFQ entrance section for a low-charge-state linac. Early results indicate that a low- frequency (12 MHz) RFQ, operated on a high-voltage platform, and injected with a pre-bunched beam, can provide ATLAS quality beams of ions of charge-to-mass ratio less than 1/132.

  15. State of charge sensing means

    SciTech Connect

    Whitford, D.R.

    1980-05-13

    Electrolyte from a battery cell is circulated by pump, through a container which contains a hydrometer float, and back to the cell. The float has an opaque neck which interrupts light passing from a light source assembly to a light receiving assembly, and the receiving assembly controls slave means, which can be an illuminated sign, as for example a group of visible light emitting diodes, the number of which illuminated indicating the density of the electrolyte. The slave means can alternatively be a volt meter, or a battery charger, the rate of charge of which is controlled by a voltage signal.

  16. Reliable absolute palaeointensities independent of magnetic domain state

    NASA Astrophysics Data System (ADS)

    Dekkers, Mark J.; Böhnel, Harald N.

    2006-08-01

    Knowledge of palaeointensity variation is required for determining the full vector variation of the geomagnetic field as a function of geological time. This provides essential constraints for numerical geodynamo models. To date, most palaeointensity determination methods are laborious, characterised by rather low success rates, and demand substantial processing time. The rocks under investigation must obey stringent criteria to yield faithful palaeointensities: the magnetic particles must be single domain, the natural remanent magnetisation must be a thermoremanent magnetisation, and during the successive heating steps in the laboratory no chemical alteration should occur. Here, we describe a new method that allows all magnetic domain states to be processed, i.e. it does not require single domain particles. The method makes use of the linearity of partial thermoremanent magnetisation (pTRM) with the applied laboratory field. Multiple specimens are used so that every sample is exposed only once to a laboratory field, warranting that all samples experienced the same magnetic history. Through the limited number of thermal steps alteration effects are reduced as well. The laboratory pTRM and natural remanent magnetisation (NRM) of the specimens are oriented parallel to minimise the effects of high-temperature tails that affect multidomain minerals. The pTRM acquisition temperature is selected below the temperature at which chemical alteration sets in and above the temperature trajectory where secondary viscous NRM components occur. The procedure requires a lower number of steps than any other palaeointensity method, reducing significantly the total time needed per rock unit. We propose to name the new protocol 'multispecimen parallel differential pTRM method'. It provides the correct answer to ˜ 5% for artificial samples and natural rocks containing multidomain magnetic particles that were given a laboratory TRM of known intensity. Application to the Paricutin

  17. Electronically shielded solid state charged particle detector

    DOEpatents

    Balmer, D.K.; Haverty, T.W.; Nordin, C.W.; Tyree, W.H.

    1996-08-20

    An electronically shielded solid state charged particle detector system having enhanced radio frequency interference immunity includes a detector housing with a detector entrance opening for receiving the charged particles. A charged particle detector having an active surface is disposed within the housing. The active surface faces toward the detector entrance opening for providing electrical signals representative of the received charged particles when the received charged particles are applied to the active surface. A conductive layer is disposed upon the active surface. In a preferred embodiment, a nonconductive layer is disposed between the conductive layer and the active surface. The conductive layer is electrically coupled to the detector housing to provide a substantially continuous conductive electrical shield surrounding the active surface. The inner surface of the detector housing is supplemented with a radio frequency absorbing material such as ferrite. 1 fig.

  18. Electronically shielded solid state charged particle detector

    SciTech Connect

    Balmer, D.K.; Haverty, T.W.; Nordin, C.W.; Tyree, W.H.

    1995-12-31

    An electronically shielded solid state charged particle detector system having enhanced radio frequency interference immunity includes a detector housing with a detector entrance opening for receiving the charged particles. A charged particle detector having an active surface is disposed within the housing. The active surface faces toward the detector entrance opening for providing electrical signals representative of the received charged particles when the received charged particles are applied to the active surface. A conductive layer is disposed upon the active surface. In a preferred embodiment, a nonconductive layer is disposed between the conductive layer and the active surface. The conductive layer is electrically coupled to the detector housing to provide a substantially continuous conductive electrical shield surrounding the active surface. The inner surface of the detector housing is supplemented with a radio frequency absorbing material such as ferrite.

  19. Electronically shielded solid state charged particle detector

    DOEpatents

    Balmer, David K.; Haverty, Thomas W.; Nordin, Carl W.; Tyree, William H.

    1996-08-20

    An electronically shielded solid state charged particle detector system having enhanced radio frequency interference immunity includes a detector housing with a detector entrance opening for receiving the charged particles. A charged particle detector having an active surface is disposed within the housing. The active surface faces toward the detector entrance opening for providing electrical signals representative of the received charged particles when the received charged particles are applied to the active surface. A conductive layer is disposed upon the active surface. In a preferred embodiment, a nonconductive layer is disposed between the conductive layer and the active surface. The conductive layer is electrically coupled to the detector housing to provide a substantially continuous conductive electrical shield surrounding the active surface. The inner surface of the detector housing is supplemented with a radio frequency absorbing material such as ferrite.

  20. Ion charge state fluctuations in vacuum arcs

    SciTech Connect

    Anders, Andre; Fukuda, Kentaro; Yushkov, Georgy Yu

    2004-12-14

    Ion charge state distributions of cathodic vacuum arcs have been investigated using a modified time-of-flight method. Experiments have been done in double gate and burst gate mode, allowing us to study both systematic and stochastic changes of ion charge state distributions with a time resolution down to 100 ns. In the double gate method, two ion charge spectra are recorded with a well-defined time between measurements. The elements Mg, Bi, and Cu were selected for tests, representing metals of very different properties. For all elements it was found that large stochastic changes occur even at the limit of resolution. This is in agreement with fast changing arc properties observed elsewhere. Correlation of results for short times between measurements was found but it is argued that this is due to velocity mixing rather than due to cathode processes. The burst mode of time-of-flight measurements revealed the systematic time evolution of ion charge states within a single arc discharge, as opposed to previous measurements that relied on data averaged over many pulses. The technique shows the decay of the mean ion charge state as well as the level of material-dependent fluctuations.

  1. Absolute single and multiple charge exchange cross sections for highly charged C, O, and Ne ions on H{sub 2}O, CO, and CO{sub 2}

    SciTech Connect

    Mawhorter, R. J.; Chutjian, A.; Djuric, N.; Hossain, S.; MacAskill, J. A.; Smith, S. J.; Simcic, J.; Cravens, T. E.; Lisse, C. M.; Williams, I. D.

    2007-03-15

    Reported herein are measured absolute single, double, and triple charge exchange (CE) cross sections for the highly charged ions (HCIs) C{sup q+} (q=5,6), O{sup q+} (q=6,7,8), and Ne{sup q+} (q=7,8) colliding with the molecular species H{sub 2}O, CO, and CO{sub 2}. Present data can be applied to interpreting observations of x-ray emissions from comets as they interact with the solar wind. As such, the ion impact energies of 7.0q keV (1.62-3.06 keV/amu) are representative of the fast solar wind, and data at 1.5q keV for O{sup 6+} (0.56 keV/amu) on CO and CO{sub 2} and 3.5q keV for O{sup 5+} (1.09 keV/amu) on CO provide checks of the energy dependence of the cross sections at intermediate and typical slow solar wind velocities. The HCIs are generated within a 14 GHz electron cyclotron resonance ion source. Absolute CE measurements are made using a retarding potential energy analyzer, with measurement of the target gas cell pressure and incident and final ion currents. Trends in the cross sections are discussed in light of the classical overbarrier model (OBM), extended OBM, and with recent results of the classical trajectory Monte Carlo theory.

  2. Absolute Charge Transfer and Fragmentation Cross Sections in He{sup 2+}-C{sub 60} Collisions

    SciTech Connect

    Rentenier, A.; Moretto-Capelle, P.; Bordenave-Montesquieu, D.; Bordenave-Montesquieu, A.; Ruiz, L. F.; Diaz-Tendero, S.; Alcami, M.; Martin, F.; Zarour, B.; Hanssen, J.; Hervieux, P.-A.; Politis, M. F.

    2008-05-09

    We have determined absolute charge transfer and fragmentation cross sections in He{sup 2+}+C{sub 60} collisions in the impact-energy range 0.1-250 keV by using a combined experimental and theoretical approach. We have found that the cross sections for the formation of He{sup +} and He{sup 0} are comparable in magnitude, which cannot be explained by the sole contribution of pure single and double electron capture but also by contribution of transfer-ionization processes that are important even at low impact energies. The results show that multifragmentation is important only at impact energies larger than 40 keV; at lower energies, sequential C{sub 2} evaporation is the dominant process.

  3. Absolute equation of state measurements of iron using laser driven shocks

    NASA Astrophysics Data System (ADS)

    Benuzzi-Mounaix, A.; Koenig, M.; Huser, G.; Faral, B.; Batani, D.; Henry, E.; Tomasini, M.; Marchet, B.; Hall, T. A.; Boustie, M.; de Rességuier, Th.; Hallouin, M.; Guyot, F.; Andrault, D.; Charpin, Th.

    2002-06-01

    First absolute equation of state measurements obtained for iron with laser driven shock waves are presented. The shock velocity and the free surface velocity of compressed iron have been simultaneously measured by using a VISAR diagnostic, and step targets. The pressure range 1-8 Mbar has been investigated, which is directly relevant to planetary physics. The experiments have been performed at the Laboratoire pour l'Utilisation des Lasers Intenses of the Ecole Polytechnique.

  4. State of charge indicators for a battery

    DOEpatents

    Rouhani, S. Zia

    1999-01-01

    The present invention relates to state of charge indicators for a battery. One aspect of the present invention utilizes expansion and contraction displacements of an electrode plate of a battery to gauge the state of charge in the battery. One embodiment of a battery of the present invention includes an anodic plate; a cathodic plate; an electrolyte in contact with the anodic and cathodic plates; plural terminals individually coupled with one of the anodic and cathodic plates; a separator intermediate the anodic and cathodic plates; an indicator configured to indicate an energy level of the battery responsive to movement of the separator; and a casing configured to house the anodic and cathodic plates, electrolyte, and separator.

  5. Solar wind ion composition and charge states

    SciTech Connect

    Vonsteiger, R.

    1995-06-01

    The solar wind, a highly tenuous plasma streaming from the Sun into interplanetary space at supersonic speed, is roughly composed of 95% hydrogen and 5% helium by number. All other, heavy elements contribute less than 0.1% by number and thus are truly test particles Nevertheless, these particles provide valuable information not present in the main components. The authors first discuss the importance of the heavy ions as tracers for processes in the solar atmosphere. Specifically, their relative abundances are found to be different in the solar wind as compared to the photosphere. This fractionation, which is best organized as a function of the first ionization time (FIT) of the elements under solar surface conditions, provides information on the structure of the chromosphere, where it is imparted on the partially ionized material by an atom-ion separation mechanism. Moreover, the charge states of the heavy ions can be used to infer the coronal temperature, since they are frozen-in near the altitude where the expansion time scale overcomes the ionization/recombination time scales. Next, the authors review the published values of ion abundances in the solar wind, concentrating on the recent results of the SWICS instrument on Ulysses. About 8 elements and more than 20 charge states can be routinely analyzed by this sensor. There is clear evidence that both the composition and the charge state distribution is significantly different in the fast solar wind from the south polar coronal hole, traversed by Ulysses in 1993/94, as compared to the solar wind normally encountered near the ecliptic plane. The fractionation between low- and high-FIT elements is reduced, and the charge states indicate a lower, more uniform coronal temperature in the hole. Finally, the authors discuss these results in the framework of existing theoretical models of the chromosphere and corona, attempting to identify differences between the low- and high-latitude regions of the solar atmosphere.

  6. Measurement of Absolute Excitation Cross Sections in Highly-Charged Ions Using Electron Energy Loss and Merged Beams

    NASA Technical Reports Server (NTRS)

    Chutjian, A.; Smith, Steven J.; Lozano, J.

    2002-01-01

    There is increasing emphasis during this decade on understanding energy balance and phenomena observed in high electron temperature plasmas. The UV spectral return from FUSE, the X-ray spectral return from the HETG on Chandra and the LETGS 011 XMM-Newton are just beginning. Line emissions are almost entirely from highly-charged ions (HCIs) of C, N, 0, Ne, Mg, S, Si, Ca, and Fe. The Constellation-X mission will provide X-ray spectroscopy up to photon energies of 0.12 nm (10 keV) where primary line emitters will be HCIs. A variety of atomic parameters are required to model the stellar and solar plasma. These include cross sections for excitation, ionization, charge-exchange, X-ray emission, direct and indirect recombination, lifetimes and branching ratios, and dependences on l, m mixing by external E and B fields. In almost all cases the atomic quantities are calculated, and few comparisons to experiment have been carried out. Collision strengths and Einstein A-values are required to convert the observed spectral intensities to electron temperatures and densities in the stellar plasma. The JPL electron energy-loss and merged beam approach has been used to measure absolute collision strengths in a number of ions, with critical comparison made to the best available theories.

  7. State approaches to the system benefits charge

    SciTech Connect

    Fang, J M

    1997-07-01

    This report documents the consideration and implementation of a non-bypassable system benefits charge (SBC) in six states through mid-May 1997. The SBC is being established to sustain important public-policy programs during the electric industry restructuring process. The states covered include Arizona, California, Massachusetts, New York, Rhode Island, and Wisconsin. This report was prepared for the Office of Energy and Resource Planning, Utah Department of Natural Resources, under the National Renewable Energy Laboratory`s Sustainable Technology Energy Partnerships Initiative, Second Round (STEP-2). The purpose of the report is to provide decision makers in Utah, including the Utah Public Service Commission and the state legislature, with relevant information on the SBC for use in their deliberation on the matter. The issues faced by the six states are the SBC in general; surcharge rate or funding levels; administrative structure and procedures; and actions, guidelines, and principles by program area.

  8. Measurement and Calculation of Absolute Single- and Multiple-Charge-Exchange Cross Sections for Feq+ Ions Impacting CO and CO2

    SciTech Connect

    Simcic, J.; Mawhorter, R. J.; Cadez, I.; Greenwood, J. B.; Chutjian, A.; Smith, S. J.

    2010-01-01

    Absolute cross sections are reported for single, double, and triple charge exchange of Feq+ (q=5- 13) ions with CO and CO2. The highly-charged Fe ions are generated in an electron cyclotron resonance ion source. Absolute data are derived from knowledge of the target gas pressure, target path length, and incident and charge-exchanged ion currents. Experimental results are compared with new calculations of these cross sections in the n-electron classical trajectory Monte-Carlo approximation, in which the ensuing radiative and non-radiative cascades are approximated with scaled hydrogenic transition probabilities and scaled Auger rates. The present data are needed in astrophysical applications of solar- and stellar-wind charge-exchange with comets, planetary atmospheres, and circumstellar clouds.

  9. 77 FR 60005 - Schedule of Charges Outside the United States

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-10-01

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF TRANSPORTATION Federal Aviation Administration Schedule of Charges Outside the United States AGENCY: Federal Aviation... of charges for services of FAA Flight Standards Aviation Safety Inspectors outside the United...

  10. Metastable states of plasma particles close to a charged surface

    SciTech Connect

    Shavlov, A. V.; Dzhumandzhi, V. A.

    2015-09-15

    The free energy of the plasma particles and the charged surface that form an electroneutral system is calculated on the basis of the Poisson-Boltzmann equation. It is shown that, owing to correlation of light plasma particles near the charged surface and close to heavy particles of high charge, there can be metastable states in plasma. The corresponding phase charts of metastable states of the separate components of plasma, and plasma as a whole, are constructed. These charts depend on temperature, the charge magnitude, the size of the particles, and the share of the charge of the light carriers out of the total charge of the plasma particles.

  11. Absolute 1* quantum yields for the ICN A state by diode laser gain versus absorption spectroscopy

    NASA Technical Reports Server (NTRS)

    Hess, Wayne P.; Leone, Stephen R.

    1987-01-01

    Absolute I* quantum yields were measured as a function of wavelength for room temperature photodissociation of the ICN A state continuum. The temperature yields are obtained by the technique of time-resolved diode laser gain-versus-absorption spectroscopy. Quantum yields are evaluated at seven wavelengths from 248 to 284 nm. The yield at 266 nm is 66.0 +/- 2% and it falls off to 53.4 +/- 2% and 44.0 +/- 4% at 284 and 248 respectively. The latter values are significantly higher than those obtained by previous workers using infrared fluorescence. Estimates of I* quantum yields obtained from analysis of CN photofragment rotational distributions, as discussed by other workers, are in good agreement with the I* yields. The results are considered in conjunction with recent theoretical and experimental work on the CN rotational distributions and with previous I* yield results.

  12. Absolute state-selected total cross sections for the O(+)(4S) + CO2 reactions

    NASA Astrophysics Data System (ADS)

    Flesch, G. D.; Ng, C. Y.

    1991-12-01

    Results are presented on measurements of absolute state-selected total cross sections for O2(+), CO2(+), CO(+), and C(+) produced in the reaction between O(+)(4S) and CO2, which were conducted in the center-of-mass collision energy (Ecm) range of 0.2-150 eV. It was found that, with increasing collisional energy, the cross section of O2(+) dropped off rapidly and became essentially zero at Ecm above 3 eV. The dependence of O2(+) cross section on the Ecm is consistent with a collision complex mechanism for the reaction between O(+)(4S) and CO2 yielding CO2(+) + O. The values for O2(+) obtained in this experiment were significantly higher than those reported by Rutherford and Vroom (1976).

  13. Solid-state conformations and absolute configurations of (+) and (-) alpha-, beta-, and gamma-hexabromocyclododecanes (HBCDs).

    PubMed

    Heeb, Norbert V; Schweizer, W Bernd; Mattrel, Peter; Haag, Regula; Gerecke, Andreas C; Kohler, Martin; Schmid, Peter; Zennegg, Markus; Wolfensberger, Max

    2007-06-01

    Hexabromocyclododecanes (HBCDs) are high production volume chemicals used as flame retardants for plastics and textiles. They are currently produced in quantities exceeding 20,000 t/y. Despite this fact, the correct stereochemistry of most HBCDs is still not known. Six stereocenters are formed during bromination of cyclododecatrienes, resulting in mixtures of different stereoisomers. Considering all elements of symmetry, 16 different stereoisomers including six pairs of enantiomers as well as 4 meso forms are possible theoretically. Recently, we isolated 8 of the 16 possible stereoisomers from a technical HBCD mixture and assigned their relative configurations. Herein, we report on the isolation of 6 enantiomerically pure alpha-, beta-, and gamma-HBCDs, obtained from preparative chiral-phase liquid chromatography, and we present their absolute configurations, which were determined from X-ray diffraction analysis. The absolute configuration of (-) alpha-HBCD was found to be (1R,2R,5S,6R,9R,10S), while the one of (+) beta-HBCD is assigned to (1S,2S,5S,6R,9S,10R), whereas the one of (-) gamma-HBCD corresponds to (1S,2S,5S,6R,9R,10S). The given structural information allows the unambiguous identification of the six most important HBCD stereoisomers, which typically account for more than 95% of technical HBCDs. In addition, we compared the solid-state conformations of racemic and enantiomerically pure alpha-, beta-, and gamma-HBCDs. In all cases, vicinal dibromides adopted a synclinal (sc) conformation with torsion angles of 69+/-6 degrees. A unique structural motive was common to all examined HBCD solid-state conformations. This conserved structure was described as an extended triple turn consisting of an arrangement of three pairs of synclinal and two antiperiplanar torsion angles. PMID:17346772

  14. Thermal State-of-Charge in Solar Heat Receivers

    NASA Technical Reports Server (NTRS)

    Hall, Carsie, A., III; Glakpe, Emmanuel K.; Cannon, Joseph N.; Kerslake, Thomas W.

    1998-01-01

    A theoretical framework is developed to determine the so-called thermal state-of-charge (SOC) in solar heat receivers employing encapsulated phase change materials (PCMS) that undergo cyclic melting and freezing. The present problem is relevant to space solar dynamic power systems that would typically operate in low-Earth-orbit (LEO). The solar heat receiver is integrated into a closed-cycle Brayton engine that produces electric power during sunlight and eclipse periods of the orbit cycle. The concepts of available power and virtual source temperature, both on a finite-time basis, are used as the basis for determining the SOC. Analytic expressions for the available power crossing the aperture plane of the receiver, available power stored in the receiver, and available power delivered to the working fluid are derived, all of which are related to the SOC through measurable parameters. Lower and upper bounds on the SOC are proposed in order to delineate absolute limiting cases for a range of input parameters (orbital, geometric, etc.). SOC characterization is also performed in the subcooled, two-phase, and superheat regimes. Finally, a previously-developed physical and numerical model of the solar heat receiver component of NASA Lewis Research Center's Ground Test Demonstration (GTD) system is used in order to predict the SOC as a function of measurable parameters.

  15. Easy Absolute Values? Absolutely

    ERIC Educational Resources Information Center

    Taylor, Sharon E.; Mittag, Kathleen Cage

    2015-01-01

    The authors teach a problem-solving course for preservice middle-grades education majors that includes concepts dealing with absolute-value computations, equations, and inequalities. Many of these students like mathematics and plan to teach it, so they are adept at symbolic manipulations. Getting them to think differently about a concept that they…

  16. Solid state cloaking for electrical charge carrier mobility control

    DOEpatents

    Zebarjadi, Mona; Liao, Bolin; Esfarjani, Keivan; Chen, Gang

    2015-07-07

    An electrical mobility-controlled material includes a solid state host material having a controllable Fermi energy level and electrical charge carriers with a charge carrier mobility. At least one Fermi level energy at which a peak in charge carrier mobility is to occur is prespecified for the host material. A plurality of particles are distributed in the host material, with at least one particle disposed with an effective mass and a radius that minimize scattering of the electrical charge carriers for the at least one prespecified Fermi level energy of peak charge carrier mobility. The minimized scattering of electrical charge carriers produces the peak charge carrier mobility only at the at least one prespecified Fermi level energy, set by the particle effective mass and radius, the charge carrier mobility being less than the peak charge carrier mobility at Fermi level energies other than the at least one prespecified Fermi level energy.

  17. Charging of a conducting sphere in a weakly ionized collisional plasma: Temporal dynamics and stationary state

    SciTech Connect

    Grach, V. S. Garasev, M. A.

    2015-07-15

    We consider the interaction of a isolated conducting sphere with a collisional weakly ionized plasma in an external field. We assume that the plasma consists of two species of ions neglecting of electrons. We take into account charging of the sphere due to sedimentation of plasma ions on it, the field of the sphere charge and the space charge, as well as recombination and molecular diffusion. The nonstationary problem of interaction of the sphere with the surrounding plasma is solved numerically. The temporal dynamics of the sphere charge and plasma perturbations is analyzed, as well as the properties of the stationary state. It is shown that the duration of transient period is determined by the recombination time and by the reverse conductivity of ions. The temporal dynamics of the sphere charge and plasma perturbations is determined by the intensity of recombination processes relative to the influence of the space charge field and diffusion. The stationary absolute value of the sphere charge increases linearly with the external electric field, decreases with the relative intensity of recombination processes and increases in the presence of substantial diffusion. The scales of the perturbed region in the plasma are determined by the radius of the sphere, the external field, the effect of diffusion, and the relative intensity of recombination processes. In the limiting case of the absence of molecular diffusion and a strong external field, the properties of the stationary state coincide with those obtained earlier as a result of approximate solution.

  18. Calculations of heavy ion charge state distributions for nonequilibrium conditions

    NASA Technical Reports Server (NTRS)

    Luhn, A.; Hovestadt, D.

    1985-01-01

    Numerical calculations of the charge state distributions of test ions in a hot plasma under nonequilibrium conditions are presented. The mean ionic charges of heavy ions for finite residence times in an instantaneously heated plasma and for a non-Maxwellian electron distribution function are derived. The results are compared with measurements of the charge states of solar energetic particles, and it is found that neither of the two simple cases considered can explain the observations.

  19. 78 FR 61446 - Schedule of Charges Outside the United States

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-10-03

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF TRANSPORTATION Federal Aviation Administration Schedule of Charges Outside the United States AGENCY: Federal Aviation... for services of FAA Flight Standards Aviation Safety Inspectors outside the United States....

  20. Quantum dynamics of charge state in silicon field evaporation

    NASA Astrophysics Data System (ADS)

    Silaeva, Elena P.; Uchida, Kazuki; Watanabe, Kazuyuki

    2016-08-01

    The charge state of an ion field-evaporating from a silicon-atom cluster is analyzed using time-dependent density functional theory coupled to molecular dynamics. The final charge state of the ion is shown to increase gradually with increasing external electrostatic field in agreement with the average charge state of silicon ions detected experimentally. When field evaporation is triggered by laser-induced electronic excitations the charge state also increases with increasing intensity of the laser pulse. At the evaporation threshold, the charge state of the evaporating ion does not depend on the electrostatic field due to the strong contribution of laser excitations to the ionization process both at low and high laser energies. A neutral silicon atom escaping the cluster due to its high initial kinetic energy is shown to be eventually ionized by external electrostatic field.

  1. Charge-displacement analysis for excited states

    SciTech Connect

    Ronca, Enrico Tarantelli, Francesco; Pastore, Mariachiara Belpassi, Leonardo; De Angelis, Filippo; Angeli, Celestino; Cimiraglia, Renzo

    2014-02-07

    We extend the Charge-Displacement (CD) analysis, already successfully employed to describe the nature of intermolecular interactions [L. Belpassi et al., J. Am. Chem. Soc. 132, 13046 (2010)] and various types of controversial chemical bonds [L. Belpassi et al., J. Am. Chem. Soc. 130, 1048 (2008); N. Salvi et al., Chem. Eur. J. 16, 7231 (2010)], to study the charge fluxes accompanying electron excitations, and in particular the all-important charge-transfer (CT) phenomena. We demonstrate the usefulness of the new approach through applications to exemplary excitations in a series of molecules, encompassing various typical situations from valence, to Rydberg, to CT excitations. The CD functions defined along various spatial directions provide a detailed and insightful quantitative picture of the electron displacements taking place.

  2. Charge-displacement analysis for excited states

    NASA Astrophysics Data System (ADS)

    Ronca, Enrico; Pastore, Mariachiara; Belpassi, Leonardo; De Angelis, Filippo; Angeli, Celestino; Cimiraglia, Renzo; Tarantelli, Francesco

    2014-02-01

    We extend the Charge-Displacement (CD) analysis, already successfully employed to describe the nature of intermolecular interactions [L. Belpassi et al., J. Am. Chem. Soc. 132, 13046 (2010)] and various types of controversial chemical bonds [L. Belpassi et al., J. Am. Chem. Soc. 130, 1048 (2008); N. Salvi et al., Chem. Eur. J. 16, 7231 (2010)], to study the charge fluxes accompanying electron excitations, and in particular the all-important charge-transfer (CT) phenomena. We demonstrate the usefulness of the new approach through applications to exemplary excitations in a series of molecules, encompassing various typical situations from valence, to Rydberg, to CT excitations. The CD functions defined along various spatial directions provide a detailed and insightful quantitative picture of the electron displacements taking place.

  3. Charge state hysteresis in semiconductor quantum dots

    NASA Astrophysics Data System (ADS)

    Yang, C. H.; Rossi, A.; Lai, N. S.; Leon, R.; Lim, W. H.; Dzurak, A. S.

    2014-11-01

    Semiconductor quantum dots provide a two-dimensional analogy for real atoms and show promise for the implementation of scalable quantum computers. Here, we investigate the charge configurations in a silicon metal-oxide-semiconductor double quantum dot tunnel coupled to a single reservoir of electrons. By operating the system in the few-electron regime, the stability diagram shows hysteretic tunnelling events that depend on the history of the dots charge occupancy. We present a model which accounts for the observed hysteretic behaviour by extending the established description for transport in double dots coupled to two reservoirs. We demonstrate that this type of device operates like a single-electron memory latch.

  4. Charge state hysteresis in semiconductor quantum dots

    SciTech Connect

    Yang, C. H.; Rossi, A. Lai, N. S.; Leon, R.; Lim, W. H.; Dzurak, A. S.

    2014-11-03

    Semiconductor quantum dots provide a two-dimensional analogy for real atoms and show promise for the implementation of scalable quantum computers. Here, we investigate the charge configurations in a silicon metal-oxide-semiconductor double quantum dot tunnel coupled to a single reservoir of electrons. By operating the system in the few-electron regime, the stability diagram shows hysteretic tunnelling events that depend on the history of the dots charge occupancy. We present a model which accounts for the observed hysteretic behaviour by extending the established description for transport in double dots coupled to two reservoirs. We demonstrate that this type of device operates like a single-electron memory latch.

  5. The Influence of Teaching and Other Factors Upon Absolute Salaries and Salary Increments at Illinois State University

    ERIC Educational Resources Information Center

    Koch, James V.; Chizmar, John F.

    1973-01-01

    Examination is made of the determinants of both absolute salary levels and recent salary increments of professors at Illinois State. Such variables as experience, scholarly output, teaching, administration, race, sex, committee work, degrees held, and the influence of outside market demand are considered. (SM)

  6. Coulometer battery state-of-charge indicator

    NASA Technical Reports Server (NTRS)

    Birchenough, A. G.; Secunde, R.

    1970-01-01

    Mercury-column electrochemical coulometer is a linear ampere-hour integrating device consisting of a sealed glass tube containing two columns of mercury separated by a gap containing an electrolyte. The drive circuit uses operational amplifier techniques to match nonlinear charge-discharge characteristics of an alkaline battery.

  7. Spin Charge Separation in the Quantum Spin Hall State

    SciTech Connect

    Qi, Xiao-Liang; Zhang, Shou-Cheng; /Stanford U., Phys. Dept.

    2010-03-19

    The quantum spin Hall state is a topologically non-trivial insulator state protected by the time reversal symmetry. We show that such a state always leads to spin-charge separation in the presence of a {pi} flux. Our result is generally valid for any interacting system. We present a proposal to experimentally observe the phenomenon of spin-charge separation in the recently discovered quantum spin Hall system.

  8. Periodic ground state for the charged massive Schwinger model

    SciTech Connect

    Nagy, S.; Sailer, K.; Polonyi, J.

    2004-11-15

    It is shown that the charged massive Schwinger model supports a periodic vacuum structure for arbitrary charge density, similar to the common crystalline layout known in solid state physics. The dynamical origin of the inhomogeneity is identified in the framework of the bosonized model and in terms of the original fermionic variables.

  9. Charging state of atmospheric nanoparticles during the nucleation burst events

    NASA Astrophysics Data System (ADS)

    Vana, M.; Tamm, E.; Hõrrak, U.; Mirme, A.; Tammet, H.; Laakso, L.; Aalto, P. P.; Kulmala, M.

    2006-12-01

    In this work, the charging state of atmospheric nanoparticles was estimated through simultaneous measurements of aerosol size distribution and air ions mobility distribution with the aim to elucidate the formation mechanisms of atmospheric aerosols. The measurements were performed as a part of the QUEST 2 campaign at a boreal forest station in Finland. The overlapping part of the measurement ranges of the particle size spectrometers and air ion mobility spectrometers in the mass diameter interval of 2.6-40 nm was used to assess the percentage of charged particles (charging probability). This parameter was obtained as the slope of the linear regression line on the scatterplot of the measured concentrations of total (neutral + charged) and charged particles for the same diameter interval. Charging probabilities as a function of particle diameter were calculated for different days and were compared with the steady state charging probabilities of the particles in the bipolar ion atmosphere. For the smallest particles detectable by the particle size spectrometers (2.6-5 nm), the high percentages of negatively charged particles were found during the nanometer particle concentration bursts. These values considerably exceeded the values for the steady charging state and it was concluded that negative cluster ions preferably act as condensation nuclei. This effect was found to be the highest in the case of comparatively weak nucleation bursts of nanoparticles, when the rate of the homogeneous nucleation and the concentration of freshly nucleated particles were low. The nucleation burst days were classified according to the concentration of the generated smallest detectable new particles (weak and strong bursts). Approximately the same classification was obtained based on the charge asymmetry on particles with respect to the charge sign (polarity). The probabilities of negative and positive charge on the particles with the diameter of 5-20 nm were found to be nearly equal

  10. Beam charge and current neutralization of high-charge-state heavy ions

    SciTech Connect

    Logan, B.G.; Callahan, D.A.

    1997-10-29

    High-charge-state heavy-ions may reduce the accelerator voltage and cost of heavy-ion inertial fusion drivers, if ways can be found to neutralize the space charge of the highly charged beam ions as they are focused to a target in a fusion chamber. Using 2-D Particle-In- Cell simulations, we have evaluated the effectiveness of two different methods of beam neutralization: (1) by redistribution of beam charge in a larger diameter, preformed plasma in the chamber, and (2), by introducing a cold-electron-emitting source within the beam channel at the beam entrance into the chamber. We find the latter method to be much more effective for high-charge-state ions.

  11. 3D geomechanical-numerical modelling of the absolute stress state for geothermal reservoir exploration

    NASA Astrophysics Data System (ADS)

    Reiter, Karsten; Heidbach, Oliver; Moeck, Inga

    2013-04-01

    For the assessment and exploration of a potential geothermal reservoir, the contemporary in-situ stress is of key importance in terms of well stability and orientation of possible fluid pathways. However, available data, e.g. Heidbach et al. (2009) or Zang et al. (2012), deliver only point wise information of parts of the six independent components of the stress tensor. Moreover most measurements of the stress orientation and magnitude are done for hydrocarbon industry obvious in shallow depth. Interpolation across long distances or extrapolation into depth is unfavourable, because this would ignore structural features, inhomogeneity's in the crust or other local effects like topography. For this reasons geomechanical numerical modelling is the favourable method to quantify orientations and magnitudes of the 3D stress field for a geothermal reservoir. A geomechanical-numerical modelling, estimating the 3D absolute stress state, requires the initial stress state as model constraints. But in-situ stress measurements within or close by a potential reservoir are rare. For that reason a larger regional geomechanical-numerical model is necessary, which derive boundary conditions for the wanted local reservoir model. Such a large scale model has to be tested against in-situ stress measurements, orientations and magnitudes. Other suitable and available data, like GPS measurements or fault slip rates are useful to constrain kinematic boundary conditions. This stepwise approach from regional to local scale takes all stress field factors into account, from first over second up to third order. As an example we present a large scale crustal and upper mantle 3D-geomechanical-numerical model of the Alberta Basin and the surroundings, which is constructed to describe continuously the full stress tensor. In-situ stress measurements are the most likely data, because they deliver the most direct information's of the stress field and they provide insights into different depths, a

  12. Increasing Protein Charge State When Using Laser Electrospray Mass Spectrometry

    NASA Astrophysics Data System (ADS)

    Karki, Santosh; Flanigan, Paul M.; Perez, Johnny J.; Archer, Jieutonne J.; Levis, Robert J.

    2015-05-01

    Femtosecond (fs) laser vaporization is used to transfer cytochrome c, myoglobin, lysozyme, and ubiquitin from the condensed phase into an electrospray (ES) plume consisting of a mixture of a supercharging reagent, m-nitrobenzyl alcohol ( m-NBA), and trifluoroacetic acid (TFA), acetic acid (AA), or formic acid (FA). Interaction of acid-sensitive proteins like cytochrome c and myoglobin with the highly charged ES droplets resulted in a shift to higher charge states in comparison with acid-stable proteins like lysozyme and ubiquitin. Laser electrospray mass spectrometry (LEMS) measurements showed an increase in both the average charge states (Zavg) and the charge state with maximum intensity (Zmode) for acid-sensitive proteins compared with conventional electrospray ionization mass spectrometry (ESI-MS) under equivalent solvent conditions. A marked increase in ion abundance of higher charge states was observed for LEMS in comparison with conventional electrospray for cytochrome c (ranging from 19+ to 21+ versus 13+ to 16+) and myoglobin (ranging from 19+ to 26+ versus 18+ to 21+) using an ES solution containing m-NBA and TFA. LEMS measurements as a function of electrospray flow rate yielded increasing charge states with decreasing flow rates for cytochrome c and myoglobin.

  13. Interfacial Charge Transfer States in Condensed Phase Systems

    NASA Astrophysics Data System (ADS)

    Vandewal, Koen

    2016-05-01

    Intermolecular charge transfer (CT) states at the interface between electron-donating (D) and electron-accepting (A) materials in organic thin films are characterized by absorption and emission bands within the optical gap of the interfacing materials. CT states efficiently generate charge carriers for some D-A combinations, and others show high fluorescence quantum efficiencies. These properties are exploited in organic solar cells, photodetectors, and light-emitting diodes. This review summarizes experimental and theoretical work on the electronic structure and interfacial energy landscape at condensed matter D-A interfaces. Recent findings on photogeneration and recombination of free charge carriers via CT states are discussed, and relations between CT state properties and optoelectronic device parameters are clarified.

  14. Interfacial Charge Transfer States in Condensed Phase Systems.

    PubMed

    Vandewal, Koen

    2016-05-27

    Intermolecular charge transfer (CT) states at the interface between electron-donating (D) and electron-accepting (A) materials in organic thin films are characterized by absorption and emission bands within the optical gap of the interfacing materials. CT states efficiently generate charge carriers for some D-A combinations, and others show high fluorescence quantum efficiencies. These properties are exploited in organic solar cells, photodetectors, and light-emitting diodes. This review summarizes experimental and theoretical work on the electronic structure and interfacial energy landscape at condensed matter D-A interfaces. Recent findings on photogeneration and recombination of free charge carriers via CT states are discussed, and relations between CT state properties and optoelectronic device parameters are clarified. PMID:26980308

  15. Charged anisotropic matter with linear or nonlinear equation of state

    SciTech Connect

    Varela, Victor; Rahaman, Farook; Ray, Saibal; Chakraborty, Koushik; Kalam, Mehedi

    2010-08-15

    Ivanov pointed out substantial analytical difficulties associated with self-gravitating, static, isotropic fluid spheres when pressure explicitly depends on matter density. Simplifications achieved with the introduction of electric charge were noticed as well. We deal with self-gravitating, charged, anisotropic fluids and get even more flexibility in solving the Einstein-Maxwell equations. In order to discuss analytical solutions we extend Krori and Barua's method to include pressure anisotropy and linear or nonlinear equations of state. The field equations are reduced to a system of three algebraic equations for the anisotropic pressures as well as matter and electrostatic energy densities. Attention is paid to compact sources characterized by positive matter density and positive radial pressure. Arising solutions satisfy the energy conditions of general relativity. Spheres with vanishing net charge contain fluid elements with unbounded proper charge density located at the fluid-vacuum interface. Notably the electric force acting on these fluid elements is finite, although the acting electric field is zero. Net charges can be huge (10{sup 19}C) and maximum electric field intensities are very large (10{sup 23}-10{sup 24} statvolt/cm) even in the case of zero net charge. Inward-directed fluid forces caused by pressure anisotropy may allow equilibrium configurations with larger net charges and electric field intensities than those found in studies of charged isotropic fluids. Links of these results with charged strange quark stars as well as models of dark matter including massive charged particles are highlighted. The van der Waals equation of state leading to matter densities constrained by cubic polynomial equations is briefly considered. The fundamental question of stability is left open.

  16. 20 CFR 416.2161 - Charges to States.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... determinations is charged in the following manner: (1) If making Medicaid determinations and providing basic SSI... the SSI program. (2) The State must pay half our additional cost caused by providing any information... basic SSI application information causes us additional cost, the State must pay our full additional...

  17. Microwave Emission from Hybridized States in a Semiconductor Charge Qubit

    NASA Astrophysics Data System (ADS)

    Stockklauser, A.; Maisi, V. F.; Basset, J.; Cujia, K.; Reichl, C.; Wegscheider, W.; Ihn, T.; Wallraff, A.; Ensslin, K.

    2015-07-01

    We explore the microwave radiation emitted from a biased double quantum dot due to the inelastic tunneling of single charges. Radiation is detected over a broad range of detuning configurations between the dot energy levels, with pronounced maxima occurring in resonance with a capacitively coupled transmission line resonator. The power emitted for forward and reverse resonant detuning is found to be in good agreement with a rate equation model, which considers the hybridization of the individual dot charge states.

  18. Microwave Emission from Hybridized States in a Semiconductor Charge Qubit.

    PubMed

    Stockklauser, A; Maisi, V F; Basset, J; Cujia, K; Reichl, C; Wegscheider, W; Ihn, T; Wallraff, A; Ensslin, K

    2015-07-24

    We explore the microwave radiation emitted from a biased double quantum dot due to the inelastic tunneling of single charges. Radiation is detected over a broad range of detuning configurations between the dot energy levels, with pronounced maxima occurring in resonance with a capacitively coupled transmission line resonator. The power emitted for forward and reverse resonant detuning is found to be in good agreement with a rate equation model, which considers the hybridization of the individual dot charge states. PMID:26252704

  19. Evaluation of several state-of-charge algorithms

    NASA Astrophysics Data System (ADS)

    Espinosa, J. M.; Martin, M. E.; Burke, A. F.

    1988-09-01

    One of the important needs in marketing an electric vehicle is a device which reliably indicates battery state-of-charge for all types of driving. The purpose of the state-of-charge indicator is analogous to a gas gauge in an internal combustion engine powered vehicle. Many different approaches have been tried to accurately predict battery state-of-charge. This report evaluates several of these approaches. Four different algorithms were implemented into software on an IBM PC and tested using a battery test database for ALCO 2200 lead-acid batteries generated at the INEL. The database was obtained under controlled conditions which compare with the battery response in real EV use. Each algorithm is described in detail as to theory and operational functionality. Also discussed is the hardware and data requirements particular to implementing the individual algorithms. The algorithms were evaluated for accuracy using constant power, stepped power, and simulated vehicle (SFUDS79) discharge profiles. Attempts were made to explain the cause of differences between the predicted and actual state-of-charge and to provide possible remedies to correct them. Recommendations for future work on battery state-of-charge indicators are presented that utilize the hardware and software now in place in the INEL Battery Laboratory.

  20. Iron charge states observed in the solar wind

    NASA Technical Reports Server (NTRS)

    Ipavich, F. M.; Galvin, A. B.; Gloeckler, G.; Hovestadt, D.; Klecker, B.; Scholer, M.

    1983-01-01

    Solar wind measurements from the ULECA sensor of the Max-Planck-Institut/University of Maryland experiment on ISEE-3 are reported. The low energy section of approx the ULECA sensor selects particles by their energy per charge (over the range 3.6 keV/Q to 30 keV/Q) and simultaneously measures their total energy with two low-noise solid state detectors. Solar wind Fe charge state measurements from three time periods of high speed solar wind occurring during a post-shock flow and a coronal hole-associated high speed stream are presented. Analysis of the post-shock flow solar wind indicates the charge state distributions for Fe were peaked at approx +16, indicative of an unusually high coronal temperature (3,000,000 K). In contrast, the Fe charge state distribution observed in a coronal hole-associated high speed stream peaks at approx -9, indicating a much lower coronal temperature (1,400,000 K). This constitutes the first reported measurements of iron charge states in a coronal hole-associated high speed stream.

  1. Measurements of charge state breeding efficiency at BNL test EBIS

    SciTech Connect

    Kondrashev, S.; Alessi, J.; Beebe, E.N.; Dickerson, C.; Ostroumov, P.N.; Pikin, A.; Savard, G.

    2011-04-02

    Charge breeding of singly charged ions is required to efficiently accelerate rare isotope ion beams for nuclear and astrophysics experiments, and to enhance the accuracy of low-energy Penning trap-assisted spectroscopy. An efficient charge breeder for the Californium Rare Isotope Breeder Upgrade (CARIBU) to the ANL Tandem Linear Accelerator System (ATLAS) facility is being developed using the BNL Test Electron Beam Ion Source (Test EBIS) as a prototype. Parameters of the CARIBU EBIS charge breeder are similar to those of the BNL Test EBIS except the electron beam current will be adjustable in the range from 1 to 2 {angstrom}. The electron beam current density in the CARIBU EBIS trap will be significantly higher than in existing operational charge state breeders based on the EBIS concept. The charge state breeding efficiency is expected to be about 25% for the isotope ions extracted from the CARIBU. For the success of our EBIS project, it is essential to demonstrate high breeding efficiency at the BNL Test EBIS tuned to the regime close to the parameters of the CARIBU EBIS at ANL. The breeding efficiency optimization and measurements have been successfully carried out using a Cs{sup +} surface ionization ion source for externally pulsed injection into the BNL Test EBIS. A Cs{sup +} ion beam with a total number of ions of 5 x 10{sup 8} and optimized pulse length of 70 {mu}s has been injected into the Test EBIS and charge-bred for 5.3 ms for two different electron beam currents 1 and 1.5 {angstrom}. In these experiments we have achieved 70% injection/extraction efficiency and breeding efficiency into the most abundant charge state 17%.

  2. SUPRATHERMAL ELECTRONS IN THE SOLAR CORONA: CAN NONLOCAL TRANSPORT EXPLAIN HELIOSPHERIC CHARGE STATES?

    SciTech Connect

    Cranmer, Steven R.

    2014-08-20

    There have been several ideas proposed to explain how the Sun's corona is heated and how the solar wind is accelerated. Some models assume that open magnetic field lines are heated by Alfvén waves driven by photospheric motions and dissipated after undergoing a turbulent cascade. Other models posit that much of the solar wind's mass and energy is injected via magnetic reconnection from closed coronal loops. The latter idea is motivated by observations of reconnecting jets and also by similarities of ion composition between closed loops and the slow wind. Wave/turbulence models have also succeeded in reproducing observed trends in ion composition signatures versus wind speed. However, the absolute values of the charge-state ratios predicted by those models tended to be too low in comparison with observations. This Letter refines these predictions by taking better account of weak Coulomb collisions for coronal electrons, whose thermodynamic properties determine the ion charge states in the low corona. A perturbative description of nonlocal electron transport is applied to an existing set of wave/turbulence models. The resulting electron velocity distributions in the low corona exhibit mild suprathermal tails characterized by ''kappa'' exponents between 10 and 25. These suprathermal electrons are found to be sufficiently energetic to enhance the charge states of oxygen ions, while maintaining the same relative trend with wind speed that was found when the distribution was assumed to be Maxwellian. The updated wave/turbulence models are in excellent agreement with solar wind ion composition measurements.

  3. Silicon radiation detectors with oxide charge state compensation

    NASA Technical Reports Server (NTRS)

    Walton, J. T.; Goulding, F. S.

    1987-01-01

    This paper discusses the use of boron implantation on high resistivity P type silicon before oxide growth to compensate for the presence of charge states in the oxide and oxide/silicon interface. The presence of these charge states on high resistivity P type silicon produces an inversion layer which causes high leakage currents on N(+)P junctions and high surface conductance. Compensating the surface region by boron implantation is shown to result in oxide passivated N(+)P junctions with very low leakage currents and with low surface conductance.

  4. Evidence for Absolute Moral Opposition to Genetically Modified Food in the United States.

    PubMed

    Scott, Sydney E; Inbar, Yoel; Rozin, Paul

    2016-05-01

    Public opposition to genetic modification (GM) technology in the food domain is widespread (Frewer et al., 2013). In a survey of U.S. residents representative of the population on gender, age, and income, 64% opposed GM, and 71% of GM opponents (45% of the entire sample) were "absolutely" opposed-that is, they agreed that GM should be prohibited no matter the risks and benefits. "Absolutist" opponents were more disgust sensitive in general and more disgusted by the consumption of genetically modified food than were non-absolutist opponents or supporters. Furthermore, disgust predicted support for legal restrictions on genetically modified foods, even after controlling for explicit risk-benefit assessments. This research suggests that many opponents are evidence insensitive and will not be influenced by arguments about risks and benefits. PMID:27217243

  5. Charge states of medium energy He ions scattered from single and poly-crystal surfaces

    NASA Astrophysics Data System (ADS)

    Okazawa, T.; Shibuya, K.; Nishimura, T.; Kido, Y.

    2007-03-01

    High-resolution medium energy ion scattering (MEIS) spectroscopy has unveiled fine structures of surfaces and interfaces. However, problematic issues arise due to its excellent energy resolution. In particular, when one uses He+ beams, the He+ fraction η+ (1) for the scattering component from top-layer atoms is frequently non-equilibrated owing to short exit path length. This leads to significant uncertainties of the absolute amount of atoms located on top of a surface. To overcome this difficulty, it is essential to acquire reliable data of equilibrium and non-equilibrium charge fractions and also to model the charge exchange process based on a simple picture. In this paper, we analyze the MEIS spectra from single and poly crystals of Si, Ni and Cu together with c-axis oriented graphite and derive electron capture (σ10) and loss (σ01) cross sections dependent on emerging ion velocity. Here, we assume that a He ion when arrives at a Maffin-tin sphere after a large angle collision takes the He+ state and then undergoes many charge exchanging collisions with valence electrons until leaving an electronic surface. The velocity dependent σ10 and σ01 values derived well reproduce equilibrium and non-equilibrium charge fractions of He+ except for graphite and poly-crystal Si at relatively large emerging angles. Such a deviation comes from the markedly anisotropic distributions of the valence electrons of Si and graphite with strong covalent bonds.

  6. Dynamic battery cell model and state of charge estimation

    NASA Astrophysics Data System (ADS)

    Wijewardana, S.; Vepa, R.; Shaheed, M. H.

    2016-03-01

    Mathematical modelling and the dynamic simulation of battery storage systems can be challenging and demanding due to the nonlinear nature of the battery chemistry. This paper introduces a new dynamic battery model, with application to state of charge estimation, considering all possible aspects of environmental conditions and variables. The aim of this paper is to present a suitable convenient, generic dynamic representation of rechargeable battery dynamics that can be used to model any Lithium-ion rechargeable battery. The proposed representation is used to develop a dynamic model considering the thermal balance of heat generation mechanism of the battery cell and the ambient temperature effect including other variables such as storage effects, cyclic charging, battery internal resistance, state of charge etc. The results of the simulations have been used to study the characteristics of a Lithium-ion battery and the proposed battery model is shown to produce responses within 98% of known experimental measurements.

  7. Fast electronic resistance switching involving hidden charge density wave states

    PubMed Central

    Vaskivskyi, I.; Mihailovic, I. A.; Brazovskii, S.; Gospodaric, J.; Mertelj, T.; Svetin, D.; Sutar, P.; Mihailovic, D.

    2016-01-01

    The functionality of computer memory elements is currently based on multi-stability, driven either by locally manipulating the density of electrons in transistors or by switching magnetic or ferroelectric order. Another possibility is switching between metallic and insulating phases by the motion of ions, but their speed is limited by slow nucleation and inhomogeneous percolative growth. Here we demonstrate fast resistance switching in a charge density wave system caused by pulsed current injection. As a charge pulse travels through the material, it converts a commensurately ordered polaronic Mott insulating state in 1T–TaS2 to a metastable electronic state with textured domain walls, accompanied with a conversion of polarons to band states, and concurrent rapid switching from an insulator to a metal. The large resistance change, high switching speed (30 ps) and ultralow energy per bit opens the way to new concepts in non-volatile memory devices manipulating all-electronic states. PMID:27181483

  8. Fast electronic resistance switching involving hidden charge density wave states

    NASA Astrophysics Data System (ADS)

    Vaskivskyi, I.; Mihailovic, I. A.; Brazovskii, S.; Gospodaric, J.; Mertelj, T.; Svetin, D.; Sutar, P.; Mihailovic, D.

    2016-05-01

    The functionality of computer memory elements is currently based on multi-stability, driven either by locally manipulating the density of electrons in transistors or by switching magnetic or ferroelectric order. Another possibility is switching between metallic and insulating phases by the motion of ions, but their speed is limited by slow nucleation and inhomogeneous percolative growth. Here we demonstrate fast resistance switching in a charge density wave system caused by pulsed current injection. As a charge pulse travels through the material, it converts a commensurately ordered polaronic Mott insulating state in 1T-TaS2 to a metastable electronic state with textured domain walls, accompanied with a conversion of polarons to band states, and concurrent rapid switching from an insulator to a metal. The large resistance change, high switching speed (30 ps) and ultralow energy per bit opens the way to new concepts in non-volatile memory devices manipulating all-electronic states.

  9. Fast electronic resistance switching involving hidden charge density wave states.

    PubMed

    Vaskivskyi, I; Mihailovic, I A; Brazovskii, S; Gospodaric, J; Mertelj, T; Svetin, D; Sutar, P; Mihailovic, D

    2016-01-01

    The functionality of computer memory elements is currently based on multi-stability, driven either by locally manipulating the density of electrons in transistors or by switching magnetic or ferroelectric order. Another possibility is switching between metallic and insulating phases by the motion of ions, but their speed is limited by slow nucleation and inhomogeneous percolative growth. Here we demonstrate fast resistance switching in a charge density wave system caused by pulsed current injection. As a charge pulse travels through the material, it converts a commensurately ordered polaronic Mott insulating state in 1T-TaS2 to a metastable electronic state with textured domain walls, accompanied with a conversion of polarons to band states, and concurrent rapid switching from an insulator to a metal. The large resistance change, high switching speed (30 ps) and ultralow energy per bit opens the way to new concepts in non-volatile memory devices manipulating all-electronic states. PMID:27181483

  10. Charge-state enhancement for radioactive beam post-acceleration

    SciTech Connect

    Nolen, J.A.; Dooling, J.

    1995-08-01

    A critical question for an ISOL-type radioactive-beam facility, such as that being discussed by the North American Isospin Laboratory Committee, is the efficiency and q/m of the ion source for the radioactive species. ISOLDE at CERN demonstrated that high efficiency is obtained for a wide variety of species in the 1{sup +} charge state. These ion sources also generally have excellent transverse emittances and low energy spreads. One possibility is to use this proven technology plus an ionizer stage to increase the output of such sources to 2, 3, or 4{sup +} with high efficiency. We are currently investigating technical options for such charge-state enhancement. There is a proposal by a Heidelberg/ISOLDE collaboration to build a {open_quotes}charge-state breeder{close_quotes} as part of an experiment called REX-ISOLDE. This concept would deliver batches of radioactive ions with low duty cycle, optimized for relatively low-intensity secondary beams, on the order of 10{sup 6}/sec. We are independently doing simulations of an alternative approach, called the Electron-Beam Charge-State Amplifier (EBQA), which would yield DC beams with improved transverse emittance and would not have the intensity limitation of the batch transfer process. The cost and efficiency of the EBQA will have to be compared with those of a normally-conducting CW RFQ followed by ion stripping, as alternatives for the first stage of a secondary ion accelerator.

  11. 75 FR 65401 - Schedule of Charges Outside the United States

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-10-22

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF TRANSPORTATION Federal Aviation Administration Schedule of Charges Outside the United States AGENCY: Federal Aviation... announcing the availability of Advisory Circular (AC) 187-1D which transmits an updated schedule of...

  12. Radiocarbon measurement with 1 MV AMS at charge state 1+

    NASA Astrophysics Data System (ADS)

    Sung, K. H.; Hong, W.; Park, G.; Lee, J. G.

    2015-10-01

    A 1 MV AMS was installed at KIGAM (Korea Institute of Geoscience and Mineral Resources) in 2007. We usually measure 14C at charge state 2+ because beam transmission yield reaches maximum value at a terminal voltage of 950 kV. However, this condition always has the possibility of interference by Li22+ molecules. To avoid the interference, samples with high Li contents need to be measured with charge states 1+ or 3+ because lithium ions only form the even charge states. Therefore, it was necessary to investigate the operating conditions of our AMS machine with charge state 1+ or 3+. The optimized condition for 1+ measurement was found to be 500 kV for terminal voltage and 2.5 × 10-2 mbar for stripper gas pressure. After setting up operating conditions for measurement with C1+, standard (IAEA C1, C7 and C8), blank, unknown wood and charcoal samples were measured and the results were compared with those obtained with a C2+ beam. The background level was determined to be as low as 2-5 × 10-15 for 14C1+.

  13. Charge-transfer-state photoluminescence in asymmetric coupled quantum wells

    NASA Astrophysics Data System (ADS)

    Norris, T. B.; Vodjdani, N.; Vinter, B.; Weisbuch, C.; Mourou, G. A.

    1989-07-01

    We have performed continuous and time-resolved photoluminescence experiments on novel double-quantum-well structures in Schottky diodes. We have directly observed the buildup of a charge-transfer (CT) state in which the electrons and holes are in separate wells because of the fact that they tunnel in opposite directions. We have studied the effect of an electric field on the CT state formation, and have observed a strong, linear Stark shift of the CT luminescence.

  14. Stabilization of the potential multi-steady-state absolute instabilities in a gyrotron traveling-wave amplifier

    SciTech Connect

    Du Chaohai; Liu Pukun

    2009-10-15

    The problem of spurious oscillations induced by absolute instabilities is the most challenging one that hinders the development of the millimeter-wave gyrotron traveling-wave amplifiers (gyro-TWTs). A spurious oscillation exists as a high order axial mode (HOAM) in the interaction circuit. This paper is devoted to demonstrating the complicated steady states of these HOAMs and exploring corresponding techniques to stabilize these potential multi-steady-state absolute instabilities. The stability-oriented design principle is conveyed in a start-to-end design flow of a Ka-band TE{sub 11} mode gyro-TWT. Strong magnetic tapering near the downstream port, which is capable of cutting short the effective interaction circuit of a spurious oscillation and simultaneously boosting the amplification performance, is for the first time proposed to further improve the system stability. It is also found that an ideal prebunched electron beam in the linear stage is the necessary condition to efficient amplification in the nonlinear stage, suggesting that it is feasible to design a stable prebunching stage to replace the distributed-loss-loaded linear stage. The stability-oriented design principle provides more explicit reference for future design of a zero-drive stable gyro-TWT.

  15. Optical control of charged exciton states in tungsten disulfide

    NASA Astrophysics Data System (ADS)

    Currie, M.; Hanbicki, A. T.; Kioseoglou, G.; Jonker, B. T.

    2015-05-01

    A method is presented for optically preparing WS2 monolayers to luminescence from only the charged exciton (trion) state-completely suppressing the neutral exciton. When isolating the trion state, we observed changes in the Raman A1g intensity and an enhanced feature on the low energy side of the E12g peak. Photoluminescence and optical reflectivity measurements confirm the existence of the prepared trion state. This technique also prepares intermediate regimes with controlled luminescence amplitudes of the neutral and charged exciton. This effect is reversible by exposing the sample to air, indicating the change is mitigated by surface interactions with the ambient environment. This method provides a tool to modify optical emission energy and to isolate physical processes in this and other two-dimensional materials.

  16. Fractional charge and spin states in topological insulator constrictions

    NASA Astrophysics Data System (ADS)

    Klinovaja, Jelena; Loss, Daniel

    2015-09-01

    We theoretically investigate the properties of two-dimensional topological insulator constrictions both in the integer and fractional regimes. In the presence of a perpendicular magnetic field, the constriction functions as a spin filter with near-perfect efficiency and can be switched by electric fields only. Domain walls between different topological phases can be created in the constriction as an interface between tunneling, magnetic fields, charge density wave, or electron-electron interaction dominated regions. These domain walls host non-Abelian bound states with fractional charge and spin and result in degenerate ground states with parafermions. If a proximity gap is induced bound states give rise to an exotic Josephson current with 8 π periodicity.

  17. Measurement of the topological charge of mixed OAM states

    NASA Astrophysics Data System (ADS)

    Shutova, Mariia; Zhdanova, Alexandra; Sokolov, Alexei

    2016-05-01

    In the current work, we investigate how the technique of measuring the topological charge of an optical vortex by using a tilted convex lens (tilted lens technique) works for optical vortices in mixed orbital angular momentum (OAM) states (i.e. the case when one beam contains several components with different values of topological charge). A mixed OAM state may occur, for example, because of perturbations in the optical devices used to generate the state, such as spatial light modulators or spiral phase plates. Hence, we present experimental results and theoretical simulations for the measurement of the topological charge of mixed states with variable amounts of each component contributing to the total beam intensity. We also investigate two different cases: first, when interference between components is present (coherent addition of component OAM states), and second, when interference is absent (incoherent addition). We conclude that in both cases the results of the tilted lens technique are valid for that component of light which is dominant (i.e. the component that contributes to more than 50% of the beam's total intensity). Presenter is supported by the Herman F. Heep and Minnie Belle Heep Texas A&M University Endowed Fund administered by the Texas A&M Foundation.

  18. Momentum Distribution and Ground-State Energy of Liquid 4He at the Absolute Zero Temperature

    NASA Astrophysics Data System (ADS)

    Nishiyama, T.; Watanabe, Y.

    1980-11-01

    In the scheme of the density and phase operator approach, the momentum distribution nk and the ground-state energy E0 are obtained by employing the structure factor and the radial distribution function calculated by Chang and Campbell for the Morse dipole-dipole potential. The condensate fraction, the ratio of the occupation number of the single-particle zero-momentum state N0/N amounts to 0.096. The momentum distribution diverges as k-1 in the low-wave number limit. The ground-state energy becomes E0=-6.9NK at the mean density ρ0=0.02185Å-3.

  19. Heavy Inertial Confinement Energy: Interactions Involoving Low charge State Heavy Ion Injection Beams

    SciTech Connect

    DuBois, Robert D

    2006-04-14

    During the contract period, absolute cross sections for projectile ionization, and in some cases for target ionization, were measured for energetic (MeV/u) low-charge-state heavy ions interacting with gases typically found in high and ultra-high vacuum environments. This information is of interest to high-energy-density research projects as inelastic interactions with background gases can lead to serious detrimental effects when intense ion beams are accelerated to high energies, transported and possibly confined in storage rings. Thus this research impacts research and design parameters associated with projects such as the Heavy Ion Fusion Project, the High Current and Integrated Beam Experiments in the USA and the accelerator upgrade at GSI-Darmstadt, Germany. Via collaborative studies performed at GSI-Darmstadt, at the University of East Carolina, and Texas A&M University, absolute cross sections were measured for a series of collision systems using MeV/u heavy ions possessing most, or nearly all, of their bound electrons, e.g., 1.4 MeV/u Ar{sup +}, Xe{sup 3+}, and U{sup 4,6,10+}. Interactions involving such low-charge-state heavy ions at such high energies had never been previously explored. Using these, and data taken from the literature, an empirical model was developed for extrapolation to much higher energies. In order to extend our measurements to much higher energies, the gas target at the Experimental Storage Ring in GSI-Darmstadt was used. Cross sections were measured between 20 and 50 MeV/u for U{sup 28+}- H{sub 2} and - N{sub 2}, the primary components found in high and ultra-high vacuum systems. Storage lifetime measurements, information inversely proportional to the cross section, were performed up to 180 MeV/u. The lifetime and cross section data test various theoretical approaches used to calculate cross sections for many-electron systems. Various high energy density research projects directly benefit by this information. As a result, the general

  20. Solid-state track recorder dosimetry device to measure absolute reaction rates and neutron fluence as a function of time

    DOEpatents

    Gold, Raymond; Roberts, James H.

    1989-01-01

    A solid state track recording type dosimeter is disclosed to measure the time dependence of the absolute fission rates of nuclides or neutron fluence over a period of time. In a primary species an inner recording drum is rotatably contained within an exterior housing drum that defines a series of collimating slit apertures overlying windows defined in the stationary drum through which radiation can enter. Film type solid state track recorders are positioned circumferentially about the surface of the internal recording drum to record such radiation or its secondary products during relative rotation of the two elements. In another species both the recording element and the aperture element assume the configuration of adjacent disks. Based on slit size of apertures and relative rotational velocity of the inner drum, radiation parameters within a test area may be measured as a function of time and spectra deduced therefrom.

  1. Meta-Stable Magnetic Domain States That Prevent Reliable Absolute Palaeointensity Experiments Revealed By Magnetic Force Microscopy

    NASA Astrophysics Data System (ADS)

    de Groot, L. V.; Fabian, K.; Bakelaar, I. A.; Dekkers, M. J.

    2014-12-01

    Obtaining reliable estimates of the absolute palaeointensity of the Earth's magnetic field is notoriously difficult. Many methods to obtain paleointensities from suitable records such as lavas and archeological artifacts involve heating the samples. These heating steps are believed to induce 'magnetic alteration' - a process that is still poorly understood but prevents obtaining correct paleointensity estimates. To observe this magnetic alteration directly we imaged the magnetic domain state of titanomagnetite particles - a common carrier of the magnetic remanence in samples used for paleointensity studies. We selected samples from the 1971-flow of Mt. Etna from a site that systematically yields underestimates of the known intensity of the paleofield - in spite of rigorous testing by various groups. Magnetic Force Microscope images were taken before and after a heating step typically used in absolute palaeointensity experiments. Before heating, the samples feature distinct, blocky domains that sometimes seem to resemble a classical magnetite domain structure. After imparting a partial thermo-remanent magnetization at a temperature often critical to paleointensity experiments (250 °C) the domain state of the same titanomagnetite grains changes into curvier, wavy domains. Furthermore, these structures appeared to be unstable over time: after one-year storage in a magnetic field-free environment the domain states evolved into a viscous remanent magnetization state. Our observations may qualitatively explain reported underestimates from technically successful paleointensity experiments for this site and other sites reported previously. Furthermore the occurrence of intriguing observations such as 'the drawer storage effect' by Shaar et al (EPSL, 2011), and viscous magnetizations observed by Muxworthy and Williams (JGR, 2006) may be (partially) explained by our observations. The major implications of our study for all palaeointensity methods involving heating may be

  2. Optical control of charged exciton states in tungsten disulfide

    SciTech Connect

    Currie, M.; Hanbicki, A. T.; Jonker, B. T.; Kioseoglou, G.

    2015-05-18

    A method is presented for optically preparing WS{sub 2} monolayers to luminescence from only the charged exciton (trion) state–completely suppressing the neutral exciton. When isolating the trion state, we observed changes in the Raman A{sub 1g} intensity and an enhanced feature on the low energy side of the E{sup 1}{sub 2g} peak. Photoluminescence and optical reflectivity measurements confirm the existence of the prepared trion state. This technique also prepares intermediate regimes with controlled luminescence amplitudes of the neutral and charged exciton. This effect is reversible by exposing the sample to air, indicating the change is mitigated by surface interactions with the ambient environment. This method provides a tool to modify optical emission energy and to isolate physical processes in this and other two-dimensional materials.

  3. Spatial distribution of average charge state and deposition rate in high power impulse magnetron sputtering of copper

    SciTech Connect

    Anders, Andre; Horwat, David; Anders, Andre

    2008-05-10

    The spatial distribution of copper ions and atoms in high power impulse magnetron sputtering (HIPIMS) discharges was determined by (i) measuring the ion current to electrostatic probes and (ii) measuring the film thickness by profilometry. A set of electrostatic and collection probes were placed at different angular positions and distances from the target surface. The angular distribution of the deposition rate and the average charge state of the copper species (including ions and neutrals) were deduced.The discharge showed a distinct transition to a high current mode dominated by copper self-sputtering when the applied voltage exceeded the threshold of 535 V. For a lower voltage, the deposition rate was very low and the average charge state was found to be less than 0.4. For higher voltage (and average power), the absolute deposition rates were much higher, but they were smaller than the corresponding direct current (DC) rates if normalized to the same average power. At the high voltage level, the spatial distribution of the average charge state showed some similarities with the distribution of the magnetic field, suggesting that the generation and motion of copper ions is affected by magnetized electrons. At higher voltage, the average charge state increases with the distance from the target and locally may exceed unity, indicating the presence of significant amounts of doubly charged copper ions.

  4. Charge asymmetry in pure vibrational states of the HD molecule

    NASA Astrophysics Data System (ADS)

    Bubin, Sergiy; Leonarski, Filip; Stanke, Monika; Adamowicz, Ludwik

    2009-03-01

    Very accurate variational calculations of all rotationless states (also called pure vibrational states) of the HD molecule have been performed within the framework that does not assume the Born-Oppenheimer (BO) approximation. The non-BO wave functions of the states describing the internal motion of the proton, the deuteron, and the two electrons were expanded in terms of one-center explicitly correlated Gaussian functions multiplied by even powers of the internuclear distance. Up to 6000 functions were used for each state. Both linear and nonlinear parameters of the wave functions of all 18 states were optimized with a procedure that employs the analytical gradient of the energy with respect to the nonlinear parameters of the Gaussians. These wave functions were used to calculate expectation values of the interparticle distances and some other related quantities. The results allow elucidation of the charge asymmetry in HD as a function of the vibrational excitation.

  5. HIGH-INTENSITY, HIGH CHARGE-STATE HEAVY ION SOURCES

    SciTech Connect

    ALESSI,J.G.

    2004-08-16

    There are many accelerator applications for high intensity heavy ion sources, with recent needs including dc beams for RIA, and pulsed beams for injection into synchrotrons such as RHIC and LHC. The present status of sources producing high currents of high charge state heavy ions is reviewed. These sources include ECR, EBIS, and Laser ion sources. Benefits and limitations for these type sources are described. Possible future improvements in these sources are also mentioned.

  6. Solar Wind Charge State Composition Results from PLASTIC

    NASA Astrophysics Data System (ADS)

    Popecki, M.; Galvin, A. B.; Kistler, L. M.; Moebius, E.; Klecker, B.; Kucharek, H.; Simunac, K.; Bochsler, P.; Blush, L.; Karrer, R.; Daoudi, H.; Opitz, A.; Giammanco, C.; Wimmer-Schweingruber, R.

    2007-12-01

    The PLASTIC instrument on the STEREO spacecraft provides solar wind proton moments and heavy ion composition. Using an electrostatic analyzer with a time of flight and residual energy measurement, it can supply mass and ionic charge state for solar wind heavy ions. Preliminary results for iron will be shown for selected events, including the possible flux rope passage on May 21-22, 2007, and a near-magnetotail passage in February, 2007.

  7. New charging strategy for lithium-ion batteries based on the integration of Taguchi method and state of charge estimation

    NASA Astrophysics Data System (ADS)

    Vo, Thanh Tu; Chen, Xiaopeng; Shen, Weixiang; Kapoor, Ajay

    2015-01-01

    In this paper, a new charging strategy of lithium-polymer batteries (LiPBs) has been proposed based on the integration of Taguchi method (TM) and state of charge estimation. The TM is applied to search an optimal charging current pattern. An adaptive switching gain sliding mode observer (ASGSMO) is adopted to estimate the SOC which controls and terminates the charging process. The experimental results demonstrate that the proposed charging strategy can successfully charge the same types of LiPBs with different capacities and cycle life. The proposed charging strategy also provides much shorter charging time, narrower temperature variation and slightly higher energy efficiency than the equivalent constant current constant voltage charging method.

  8. Absolute I(asterisk) quantum yields for the ICN A state by diode laser gain-vs-absorption spectroscopy

    NASA Technical Reports Server (NTRS)

    Hess, Wayne P.; Leone, Stephen R.

    1987-01-01

    Absolute I(asterisk) quantum yields have been measured as a function of wavelength for room temperature photodissociation of the ICN A state continuum. The yields are obtained by the technique of time-resolved diode laser gain-vs-absorption spectroscopy. Quantum yields are evaluated at seven wavelengths from 248 to 284 nm. The yield at 266 nm is 66.0 + or - 2 percent and it falls off to 53.4 + or - 2 percent and 44.0 + or - 4 percent at 284 and 248 nm, respectively. The latter values are significantly higher than those obtained by previous workers using infrared fluorescence. Estimates of I(asterisk) quantum yields obtained from analysis of CN photofragment rotational distributions, as discussed by other workers, are in good agreement with the I(asterisk) yields reported here. The results are considered in conjunction with recent theoretical and experimental work on the CN rotational distributions and with previous I(asterisk) quantum yield results.

  9. Charge Order Induced in an Orbital Density-Wave State

    NASA Astrophysics Data System (ADS)

    Singh, Dheeraj Kumar; Takimoto, Tetsuya

    2016-04-01

    Motivated by recent angle resolved photoemission measurements [D. V. Evtushinsky et al., Phys. Rev. Lett. 105, 147201 (2010)] and evidence of the density-wave state for the charge and orbital ordering [J. García et al., Phys. Rev. Lett. 109, 107202 (2012)] in La0.5Sr1.5MnO4, the issue of charge and orbital ordering in a two-orbital tight-binding model for layered manganite near half doping is revisited. We find that the charge order with the ordering wavevector 2{Q} = (π ,π ) is induced by the orbital order of d-/d+-type having B1g representation with a different ordering wavevector Q, where the orbital order as the primary order results from the strong Fermi-surface nesting. It is shown that the induced charge order parameter develops according to TCO - T by decreasing the temperature below the orbital ordering temperature TCO, in addition to the usual mean-field behavior of the orbital order parameter. Moreover, the same orbital order is found to stabilize the CE-type spin arrangement observed experimentally below TCE < TCO.

  10. 26 CFR 1.163-2 - Installment purchases where interest charge is not separately stated.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 26 Internal Revenue 2 2010-04-01 2010-04-01 false Installment purchases where interest charge is... Individuals and Corporations § 1.163-2 Installment purchases where interest charge is not separately stated... carrying charge (including a finance charge, service charge, and the like) but the actual interest...

  11. Equilibrium and Dynamic Vortex States near Absolute Zero in a Weak Pinning Amorphous Film

    NASA Astrophysics Data System (ADS)

    Ochi, Aguri; Sohara, Naoya; Kaneko, Shin-ichi; Kokubo, Nobuhito; Okuma, Satoshi

    2016-04-01

    By developing and employing a mode-locking measurement with pulsed currents, we successfully determine the dynamic melting field B{c,dyn}∞ (T) for a driven vortex lattice of an amorphous MoxGe1-x film in the limit of zero temperature (T → 0) and complete a dynamic as well as a static vortex phase diagram. At T = 0, the mixed state in the absence of pinning comprises vortex-lattice and quantum-vortex-liquid (QVL) phases, and the melting field separating the two phases is identified as B{c,dyn}∞ (0). Comparison of the dynamic and static phase diagrams reveals that, when the weak pinning is introduced into the pin-free system, a disordered phase emerges just above the vortex-lattice phase and a threshold field separating the two phases is slightly suppressed from B{c,dyn}∞ (0), indicative of defect-induced disordering of the lattice. By contrast, a melting field into QVL is much enhanced from B{c,dyn}∞ (0) up to a point near the upper critical field, resulting in a significant suppression of the QVL phase. This is attributed to the stronger effective pinning at lower T, which survives quantum fluctuations.

  12. A Battery Charger and State of Charge Indicator

    NASA Technical Reports Server (NTRS)

    Latos, T. S.

    1984-01-01

    A battery charger which has a full wave rectifier in series with a transformer isolated 20 kHz dc-dc converter with high frequency switches, which are programmed to actively shape the input dc line current to be a mirror image of the ac line voltage is discussed. The power circuit operates at 2 kW peak and 1 kW average power. The BC/SCI has two major subsystems: (1) the battery charger power electronics with its controls; and (2) a microcomputer subsystem which is used to acquire battery terminal data and exercise the state of charge software programs. The state of charge definition employed is the energy remaining in the battery when extracted at a 10 kW rate divided by the energy capacity of a fully charged new battery. The battery charger circuit is an isolated boost converter operating at an internal frequency of 20 kHz. The switches selected for the battery charger are the single most important item in determining its efficiency. The combination of voltage and current requirements dictate the use of high power NPN Darlington switching transistors. The power circuit topology is a three switch design which utilizes a power FET on the center tap of the isolation transformer and the power Darlingtons on each of the two ends. An analog control system is employed to accomplish active input current waveshaping as well as the necessary regulation.

  13. Battery charger and state of charge indicator. Final report

    SciTech Connect

    Latos, T.S.

    1984-04-15

    The battery charger has a full-wave rectifier in series with a transformer isolated 20 kHz dc-dc converter with high frequency switches which are programmed to actively shape the input ac line current to be a mirror image of the ac line voltage. The power circuit is capable of operating at 2 kW peak and 1 kW average power. The BC/SCI has two major subsystems: (1) the battery charger power electronics with its controls; and (2) a microcomputer subsystem which is used to acquire battery terminal data and exercise the state-of-charge software programs. The state-of-charge definition employed is the energy remaining in the battery when extracted at a 10 kW rate divided by the energy capacity of a fully charged new battery. The battery charger circuit is an isolated boost converter operating at an internal frequency of 20 kHz. The switches selected for the battery charger are the single most important item in determining its efficiency. The combination of voltage and current requirements dictated the use of high power NPN Darlington switching transistors. The power circuit topology developed is a three switch design utilizing a power FET on the center tap of the isolation transformer and the power Darlingtons on each of the two ends. An analog control system is employed to accomplish active input current waveshaping as well as the necessary regulation.

  14. Charge state breeding experiences and plans at TRIUMF

    NASA Astrophysics Data System (ADS)

    Ames, F.; Marchetto, M.; Mjøs, A.; Morton, A. C.

    2016-02-01

    At the Isotope Separation and ACceleration (ISAC) facility at TRIUMF, an electron cyclotron resonance ion source (ECRIS) has been set up for the charge state breeding of radioactive ions. In order to reduce background from stable ions generated in the ECRIS, several measures, including changing materials for the plasma chamber and the surrounding components, have been implemented. Further reduction has been achieved by using the post-accelerator chain as a mass filter. Since the implementation of those measures in 2013, physics experiments with accelerated radioactive isotopes of Rb, Sr, K, and Mg have been performed. In most cases, a charge breeding efficiency of several percent has been achieved. With the planned expansion of the isotope production capabilities at TRIUMF within the Advanced Rare IsotopE Laboratory project, two new target stations, one using photo-fission induced by a high-power electron beam at 50 MeV and the other one using 480 MeV protons as at ISAC, will be put into operation within the next 5 yr. Additionally, a new electron beam ion source (EBIS) based charge state breeding system will be installed. Background from such a source is expected to be much lower. The drawback is that for the efficient operation of such a system, pulsed beam operation is required, which makes the installation of an additional ion buncher in front of the EBIS necessary.

  15. Air Force Ni-H2 cell test program: State of Charge test

    NASA Technical Reports Server (NTRS)

    Moore, Bruce; Smellie, Douglas

    1995-01-01

    Nickel-Hydrogen cells are being cycled under a LEO (low earth orbit) test regime to examine the benefits of operating the cells at lower States of Charge (SOC) than typically used. A group of four cells are cycled using a voltage limiting charge regime that limits the State of Charge that the cells are allowed to reach. The test cells are then compared to identical cells being cycled at or near 100% State of Charge using a constant current charge regime.

  16. Rechargeable, silver-zinc battery conditioner/monitor unit and state-of-charge indicator

    NASA Technical Reports Server (NTRS)

    Thomas, C. E.

    1974-01-01

    Unit automatically charges batteries to desired state-of-charge levels, monitors functional battery parameter data both on meters and printer, and automatically activates alarm in event of battery malfunctions. Unit consists of state-of-charge indicator panel, control panel, monitor panel, power panel, charging-current power supply, and load panel.

  17. Predicting ion charge state distributions of vacuum arc plasmas

    SciTech Connect

    Anders, A.; Schulke, T.

    1996-04-01

    Multiply charged ions are present in vacuum arc plasmas. The ions are produced at cathode spots, and their charge state distributions (CSDs) depend on the cathode material but only little on the arc current or other parameters as long as the current is relatively low and the anode is not actively involved in the plasma production. There are experimental data of ion CSDs available in the literature for 50 different cathode materials. The CSDs can be calculated based on the assumption that thermodynamic equilibrium is valid in the vicinity of the cathode spot, and the equilibrium CSDs `freeze` at a certain distance from the cathode spot (transition to a non-equilibrium plasma). Plasma temperatures and densities at the `freezing points` have been calculated, and, based on the existence of characteristic groups of elements in the Periodic Table, predictions of CSDs can be made for metallic elements which have not yet been used as cathode materials.

  18. Charge and electronic states of cuprite: Experiment and theory

    NASA Astrophysics Data System (ADS)

    Kim, Miyoung

    The bonding characteristics of cuprite have been studied by the using convergent beam electron diffraction (CBED) method. The low-order structure factors are closely related to the valence electron density, and the CBED is one of the most accurate methods of measuring the low order structure factors. The multipole model is used for converting the structure factors into charge density. The multipole expansion takes into account non-spherical valence electron density due to atomic bonding based on the crystal symmetry. The charge transfer from copper to oxygen is determined from the multipole fitting parameters. The hybridization state between 4s-3d orbitals of copper is also estimated. Electronic states of CU2O are investigated by studying the fine structure of the electron-energy loss spectrum (EELS). The cross section of the near edge structure is proportional to the density of state times an atomic transition site-projected matrix element which generally varies slowly in the region of interest. Both the fine structure of Cu- L2'3 and O-K of Cu2O are significantly different from those of CuO, which shows the sensitivity of EELS fine structure to the crystal bonding. Full-potential Linearized Augmented Plane Wave (FLAPW) calculations have been used to compare experimental results with theory. The structure factors and bonding charge density are compared with the results obtained by the CBED method, and the density of states is compared with the EELS. The FLAPW method has also been used in the local density approximations CLDA) to calculate values of the mean inner Coulomb potential V 0 for Si, Ge and MgO. These values are compared with recent measurements by electron holography. The supercell calculations are performed for crystal slabs, so that the effects of different crystal orientations and surface structures on V0 can be evaluated.

  19. Role of defect states in charge transport in semiconductor nanowires

    NASA Astrophysics Data System (ADS)

    Ko, Dongkyun; Zhao, Xianwei; Reddy, Kongara; Windl, Wolfgang; Padture, Nitin; Trivedi, Nandini; Yang, Fengyuan; Johnston-Halperin, Ezekiel

    2011-03-01

    Charge transport characteristics are investigated in Se-doped InP nanowires in order to determine the nature of the defect states. I-V curves indicate that transport is limited by trapped space charges rather than by Schottky at high bias. In addition, mobility calculations show that hopping between defect states plays an important role at low bias. A transition between hopping mechanisms as a function of temperature can be determined from the behavior of the temperature-dependent resistance R(T). Nearest neighbor hopping (NNH) is dominant in the high temperature regime (158K) , R ~exp (T 0 / T)1.03 , and Efros-Shklovskii variable range hopping (ES-VRH) is dominant in the low temperature regime (< 158K), R ~ exp (TES / T)0.49 . Gate-bias dependence of the transition temperature and hopping parameters are also investigated: these results suggest that applying positive gate-bias changes the strength of electron correlations in these quasi-1D systems. Funding for this research was provided by the Center for Emergent Materials at the Ohio State University, a NSF MRSEC (Award Number DMR-0820414).

  20. Absolute equation of state and opacity measurements of CH plastic to 40 TPa using the National Ignition Facility

    NASA Astrophysics Data System (ADS)

    Doeppner, T.; Swift, D.; Hawreliak, J.; Kritcher, A.; Collins, G.; Glenzer, S.; Rothman, S.; Chapman, D.; Gaffney, J.; Rose, S.; Falcone, R.

    2013-06-01

    We have developed an experimental configuration using a hohlraum-driven spherically-convergent shock to induce pressures into the gigabar range, measuring the Hugoniot radiographically. The shock pressure increases with convergence, so a range of Hugoniot states is obtained from a single experiment. The opacity along the Hugoniot is also deduced, which is essential in gigabar experiments as it changes significantly from its initial value. We are focusing initially on plastics, as we can reliably obtain spherical samples with the desired design of ablator, and the radiographic signal is reasonable. Our initial measurements on NIF used a conservative timing of the x-ray backlighter to allow for uncertainty in the EOS, and probed only part of the pressure range. The shock speed and compression, obtained from radiographic analysis, gave absolute Hugoniot states from 12-41 TPa, which is an order of magnitude greater than previously measured in CH. The measured EOS locus was consistent with the previous measurements, and significantly stiffer than the theoretical EOS used for comparison. Our analysis also gave the variation of opacity along the Hugoniot, which showed a decrease of an order of magnitude, as expected from atomic physics calculations. This work was performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344.

  1. Optimization of an absolute sensitivity in a glassy matrix during DNP-enhanced multidimensional solid-state NMR experiments.

    PubMed

    Takahashi, Hiroki; Fernández-de-Alba, Carlos; Lee, Daniel; Maurel, Vincent; Gambarelli, Serge; Bardet, Michel; Hediger, Sabine; Barra, Anne-Laure; De Paëpe, Gaël

    2014-02-01

    Thanks to instrumental and theoretical development, notably the access to high-power and high-frequency microwave sources, high-field dynamic nuclear polarization (DNP) on solid-state NMR currently appears as a promising solution to enhance nuclear magnetization in many different types of systems. In magic-angle-spinning DNP experiments, systems of interest are usually dissolved or suspended in glass-forming matrices doped with polarizing agents and measured at low temperature (down to ∼100K). In this work, we discuss the influence of sample conditions (radical concentration, sample temperature, etc.) on DNP enhancements and various nuclear relaxation times which affect the absolute sensitivity of DNP spectra, especially in multidimensional experiments. Furthermore, DNP-enhanced solid-state NMR experiments performed at 9.4 T are complemented by high-field CW EPR measurements performed at the same magnetic field. Microwave absorption by the DNP glassy matrix is observed even below the glass transition temperature caused by softening of the glass. Shortening of electron relaxation times due to glass softening and its impact in terms of DNP sensitivity is discussed. PMID:24480716

  2. Optimization of an absolute sensitivity in a glassy matrix during DNP-enhanced multidimensional solid-state NMR experiments

    NASA Astrophysics Data System (ADS)

    Takahashi, Hiroki; Fernández-de-Alba, Carlos; Lee, Daniel; Maurel, Vincent; Gambarelli, Serge; Bardet, Michel; Hediger, Sabine; Barra, Anne-Laure; De Paëpe, Gaël

    2014-02-01

    Thanks to instrumental and theoretical development, notably the access to high-power and high-frequency microwave sources, high-field dynamic nuclear polarization (DNP) on solid-state NMR currently appears as a promising solution to enhance nuclear magnetization in many different types of systems. In magic-angle-spinning DNP experiments, systems of interest are usually dissolved or suspended in glass-forming matrices doped with polarizing agents and measured at low temperature (down to ∼100 K). In this work, we discuss the influence of sample conditions (radical concentration, sample temperature, etc.) on DNP enhancements and various nuclear relaxation times which affect the absolute sensitivity of DNP spectra, especially in multidimensional experiments. Furthermore, DNP-enhanced solid-state NMR experiments performed at 9.4 T are complemented by high-field CW EPR measurements performed at the same magnetic field. Microwave absorption by the DNP glassy matrix is observed even below the glass transition temperature caused by softening of the glass. Shortening of electron relaxation times due to glass softening and its impact in terms of DNP sensitivity is discussed.

  3. Optical state-of-charge monitor for batteries

    DOEpatents

    Weiss, Jonathan D.

    1999-01-01

    A method and apparatus for determining the instantaneous state-of-charge of a battery in which change in composition with discharge manifests itself as a change in optical absorption. In a lead-acid battery, the sensor comprises a fiber optic system with an absorption cell or, alternatively, an optical fiber woven into an absorbed-glass-mat battery. In a lithium-ion battery, the sensor comprises fiber optics for introducing light into the anode to monitor absorption when lithium ions are introduced.

  4. Absolute Zero

    NASA Astrophysics Data System (ADS)

    Donnelly, Russell J.; Sheibley, D.; Belloni, M.; Stamper-Kurn, D.; Vinen, W. F.

    2006-12-01

    Absolute Zero is a two hour PBS special attempting to bring to the general public some of the advances made in 400 years of thermodynamics. It is based on the book “Absolute Zero and the Conquest of Cold” by Tom Shachtman. Absolute Zero will call long-overdue attention to the remarkable strides that have been made in low-temperature physics, a field that has produced 27 Nobel Prizes. It will explore the ongoing interplay between science and technology through historical examples including refrigerators, ice machines, frozen foods, liquid oxygen and nitrogen as well as much colder fluids such as liquid hydrogen and liquid helium. A website has been established to promote the series: www.absolutezerocampaign.org. It contains information on the series, aimed primarily at students at the middle school level. There is a wealth of material here and we hope interested teachers will draw their student’s attention to this website and its substantial contents, which have been carefully vetted for accuracy.

  5. Influence of Multiple Ionization on Charge State Distributions

    NASA Astrophysics Data System (ADS)

    Hahn, Michael; Savin, Daniel Wolf

    2015-08-01

    The spectrum emitted by a plasma depends on the charge state distribution (CSD) of the gas. For collisionally ionized plasmas, the CSD is is determined by the corresponding rates for electron-impact ionization and recombination. In astrophysics, such plasmas are formed in stars, supernova remnants, galaxies, and galaxy clusters. Current CSD calculations generally do not account for electron-impact multiple ionization (EIMI), a process in which multiple electrons are ejected by a single electron-ion collision. We have estimated the EIMI cross sections for all charge states of iron using a combination of the available experimental data and semi-empirical formulae. We then modeled the CSD and observed the influence of EIMI compared to only including single ionization. One case of interest for astrophysics is nanoflare heating, which is a leading theory to explain the heating of the solar corona. In order to determine whether this theory can indeed explain coronal heating, spectroscopic measurements are being compared to model nanoflare spectra. Such models have attempted to predict the spectra of impulsively heated plasmas in which the CSD is time dependent. These nonequilbirium ionization calculations have so far ignored EIMI, but our findings suggest that EIMI can have a significant effect on the CSD of a nanoflare-heated plasma, changing the ion abundances by up to about 50%.

  6. Coulomb charging energy of vacancy-induced states in graphene

    NASA Astrophysics Data System (ADS)

    Miranda, V. G.; Dias da Silva, Luis G. G. V.; Lewenkopf, C. H.

    2016-08-01

    Vacancies in graphene have been proposed to give rise to π -like magnetism in carbon materials, a conjecture which has been supported by recent experimental evidence. A key element in this "vacancy magnetism" is the formation of magnetic moments in vacancy-induced electronic states. In this work we compute the charging energy U of a single-vacancy-generated localized state for bulk graphene and graphene ribbons. We use a tight-binding model to calculate the dependency of the charging energy U on the amplitudes of the localized wave function on the graphene lattice sites. We show that for bulk graphene U scales with the system size L as (lnL) -2, confirming the predictions in the literature, based on heuristic arguments. In contrast, we find that for realistic system sizes U is of the order of eV, a value that is orders of magnitude higher than the previously reported estimates. Finally, when edges are considered, we show that U is very sensitive to the vacancy position with respect to the graphene flake boundaries. In the case of armchair nanoribbons, we find a strong enhancement of U in certain vacancy positions as compared to the value for vacancies in bulk graphene.

  7. Determination of Thermal State of Charge in Solar Heat Receivers

    NASA Technical Reports Server (NTRS)

    Glakpe, E. K.; Cannon, J. N.; Hall, C. A., III; Grimmett, I. W.

    1996-01-01

    The research project at Howard University seeks to develop analytical and numerical capabilities to study heat transfer and fluid flow characteristics, and the prediction of the performance of solar heat receivers for space applications. Specifically, the study seeks to elucidate the effects of internal and external thermal radiation, geometrical and applicable dimensionless parameters on the overall heat transfer in space solar heat receivers. Over the last year, a procedure for the characterization of the state-of-charge (SOC) in solar heat receivers for space applications has been developed. By identifying the various factors that affect the SOC, a dimensional analysis is performed resulting in a number of dimensionless groups of parameters. Although not accomplished during the first phase of the research, data generated from a thermal simulation program can be used to determine values of the dimensionless parameters and the state-of-charge and thereby obtain a correlation for the SOC. The simulation program selected for the purpose is HOTTube, a thermal numerical computer code based on a transient time-explicit, axisymmetric model of the total solar heat receiver. Simulation results obtained with the computer program are presented the minimum and maximum insolation orbits. In the absence of any validation of the code with experimental data, results from HOTTube appear reasonable qualitatively in representing the physical situations modeled.

  8. Charge structure of the hadronic final state in deep-inelastic muon-nucleon scattering

    NASA Astrophysics Data System (ADS)

    Arneodo, M.; Arvidson, A.; Aubert, J. J.; Bedełek, J.; Beaufays, J.; Bee, C. P.; Benchouk, C.; Berghoff, G.; Bird, I.; Blum, D.; Böhm, E.; de Bouard, X.; Brasse, F. W.; Braun, H.; Broll, C.; Brown, S.; Brück, H.; Calen, H.; Chima, J. S.; Ciborowski, J.; Clifft, R.; Coignet, G.; Combley, F.; Coughlan, J.; D'Agostini, G.; Dahlgren, S.; Dengler, F.; Derado, I.; Dreyer, T.; Drees, J.; Düren, M.; Eckardt, V.; Edwards, A.; Edwards, M.; Ernst, T.; Eszes, G.; Favier, J.; Ferrero, M. I.; Figiel, J.; Flauger, W.; Foster, J.; Ftáčnik, J.; Gabathuler, E.; Gajewski, J.; Gamet, R.; Gayler, J.; Geddes, N.; Grafström, P.; Grard, F.; Haas, J.; Hagberg, E.; Hasert, F. J.; Hayman, P.; Heusse, P.; Jaffré, M.; Jachołkowska, A.; Janata, F.; Jancsó, G.; Johnson, A. S.; Kabuss, E. M.; Kellner, G.; Korbel, V.; Krüger, J.; Kullander, S.; Landgraf, U.; Lanske, D.; Loken, J.; Long, K.; Maire, M.; Malecki, P.; Manz, A.; Maselli, S.; Mohr, W.; Montanet, F.; Montgomery, H. E.; Nagy, E.; Nassalski, J.; Norton, P. R.; Oakham, F. G.; Osborne, A. M.; Pascaud, C.; Pawlik, B.; Payre, P.; Peroni, C.; Peschel, H.; Pessard, H.; Pettinghale, J.; Pietrzyk, B.; Pietrzyk, U.; Pönsgen, B.; Pötsch, M.; Renton, P.; Ribarics, P.; Rith, K.; Rondio, E.; Sandacz, A.; Scheer, M.; Schlagböhmer, A.; Schiemann, H.; Schmitz, N.; Schneegans, M.; Schneider, A.; Scholz, M.; Schröder, T.; Schultze, K.; Sloan, T.; Stier, H. E.; Studt, M.; Taylor, G. N.; Thénard, J. M.; Thompson, J. C.; de La Torre, A.; Toth, J.; Urban, L.; Wallucks, W.; Whalley, M.; Wheeler, S.; Williams, W. S. C.; Wimpenny, S. J.; Windmolders, R.; Wolf, G.

    1988-09-01

    The general charge properties of the hadronic final state produced in μ + p and μ + d interactions at 280 GeV are investigated. Quark charge retention and local charge compensation is observed. The ratio F {2/ n }/ F {2/ p } of the neutron to proton structure function is derived from the measurement of the average hadronic charge in μ d interactions.

  9. The lowest-energy charge-transfer state and its role in charge separation in organic photovoltaics.

    PubMed

    Nan, Guangjun; Zhang, Xu; Lu, Gang

    2016-06-29

    Energy independent, yet higher than 90% internal quantum efficiency (IQE), has been observed in many organic photovoltaics (OPVs). However, its physical origin remains largely unknown and controversial. The hypothesis that the lowest charge-transfer (CT) state may be weakly bound at the interface has been proposed to rationalize the experimental observations. In this paper, we study the nature of the lowest-energy CT (CT1) state, and show conclusively that the CT1 state is localized in typical OPVs. The electronic couplings in the donor and acceptor are found to determine the localization of the CT1 state. We examine the geminate recombination of the CT1 state and estimate its lifetime from first principles. We identify the vibrational modes that contribute to the geminate recombination. Using material parameters determined from first principles and experiments, we carry out kinetic Monte Carlo simulations to examine the charge separation of the localized CT1 state. We find that the localized CT1 state can indeed yield efficient charge separation with IQE higher than 90%. Dynamic disorder and configuration entropy can provide the energetic and entropy driving force for charge separation. Charge separation efficiency depends more sensitively on the dimension and crystallinity of the acceptor parallel to the interface than that normal to the interface. Reorganization energy is found to be the most important material parameter for charge separation, and lowering the reorganization energy of the donor should be pursued in the materials design. PMID:27306609

  10. Charge-state-dependent energy loss of slow ions. I. Experimental results on the transmission of highly charged ions

    NASA Astrophysics Data System (ADS)

    Wilhelm, Richard A.; Gruber, Elisabeth; Smejkal, Valerie; Facsko, Stefan; Aumayr, Friedrich

    2016-05-01

    We report on energy loss measurements of slow (v ≪v0 ), highly charged (Q >10 ) ions upon transmission through a 1-nm-thick carbon nanomembrane. We emphasize here the scaling of the energy loss with the velocity and charge exchange or loss. We show that a weak linear velocity dependence exists, whereas charge exchange dominates the kinetic energy loss, especially in the case of a large charge capture. A universal scaling of the energy loss with the charge exchange and velocity is found and discussed in this paper. A model for charge-state-dependent energy loss for slow ions is presented in paper II in this series [R. A. Wilhelm and W. Möller, Phys. Rev. A 93, 052709 (2016), 10.1103/PhysRevA.93.052709].

  11. Absolute Summ

    NASA Astrophysics Data System (ADS)

    Phillips, Alfred, Jr.

    Summ means the entirety of the multiverse. It seems clear, from the inflation theories of A. Guth and others, that the creation of many universes is plausible. We argue that Absolute cosmological ideas, not unlike those of I. Newton, may be consistent with dynamic multiverse creations. As suggested in W. Heisenberg's uncertainty principle, and with the Anthropic Principle defended by S. Hawking, et al., human consciousness, buttressed by findings of neuroscience, may have to be considered in our models. Predictability, as A. Einstein realized with Invariants and General Relativity, may be required for new ideas to be part of physics. We present here a two postulate model geared to an Absolute Summ. The seedbed of this work is part of Akhnaton's philosophy (see S. Freud, Moses and Monotheism). Most important, however, is that the structure of human consciousness, manifest in Kenya's Rift Valley 200,000 years ago as Homo sapiens, who were the culmination of the six million year co-creation process of Hominins and Nature in Africa, allows us to do the physics that we do. .

  12. Anomalous Ion Charge State Behavior In Interplanetary Coronal Mass Ejections

    NASA Astrophysics Data System (ADS)

    Kocher, M.; Lepri, S. T.; Landi, E.; Zhao, L.

    2015-12-01

    A recent analysis of solar wind charge state composition measurements from the ACE/SWICS instrument showed that the expected correlation between the frozen-in values of the O7/O6 and C6/C5 ratios was violated in ~5% of the slow solar wind in the 1998-2011 period (Zhao et al. 2015). In this work we determine that such anomalous behavior is also found in over 40% of Interplanetary Coronal Mass Ejections (ICMEs), as identified by Richardson and Cane (2010). An analysis of the plasma composition during these events reveals significant depletions in densities of fully stripped ions of Carbon, Oxygen, and Nitrogen. We argue that these events are indicators of ICME plasma acceleration via magnetic reconnection near the freeze-in region of Carbon and Oxygen above the solar corona.

  13. Low charge state heavy ion production with sub-nanosecond laser

    NASA Astrophysics Data System (ADS)

    Kanesue, T.; Kumaki, M.; Ikeda, S.; Okamura, M.

    2016-02-01

    We have investigated laser ablation plasma of various species using nanosecond and sub-nanosecond lasers for both high and low charge state ion productions. We found that with sub-nanosecond laser, the generated plasma has a long tail which has low charge state ions determined by an electrostatic ion analyzer even under the laser irradiation condition for highly charged ion production. This can be caused by insufficient laser absorption in plasma plume. This property might be suitable for low charge state ion production. We used a nanosecond laser and a sub-nanosecond laser for low charge state ion production to investigate the difference of generated plasma using the Zirconium target.

  14. Battery state-of-charge estimation using approximate least squares

    NASA Astrophysics Data System (ADS)

    Unterrieder, C.; Zhang, C.; Lunglmayr, M.; Priewasser, R.; Marsili, S.; Huemer, M.

    2015-03-01

    In recent years, much effort has been spent to extend the runtime of battery-powered electronic applications. In order to improve the utilization of the available cell capacity, high precision estimation approaches for battery-specific parameters are needed. In this work, an approximate least squares estimation scheme is proposed for the estimation of the battery state-of-charge (SoC). The SoC is determined based on the prediction of the battery's electromotive force. The proposed approach allows for an improved re-initialization of the Coulomb counting (CC) based SoC estimation method. Experimental results for an implementation of the estimation scheme on a fuel gauge system on chip are illustrated. Implementation details and design guidelines are presented. The performance of the presented concept is evaluated for realistic operating conditions (temperature effects, aging, standby current, etc.). For the considered test case of a GSM/UMTS load current pattern of a mobile phone, the proposed method is able to re-initialize the CC-method with a high accuracy, while state-of-the-art methods fail to perform a re-initialization.

  15. Oxygen charge state abundance in the inner magnetosphere

    SciTech Connect

    Fennell, J.F.; Roeder, J.L.; Grande, M.; Wilken, B.

    1996-07-01

    The CRRES Magnetospheric Ion Composition Sensor (MICS) was used to obtain the relative oxygen charge state abundances in the earth{close_quote}s inner magnetosphere (3{lt}{ital L}{lt}7.5). These abundances were obtained for average and quiet ({ital Kp}{le}2+,{vert_bar}{ital D}{sub {ital ST}}{vert_bar}{lt}11) conditions. They are presented as normalized spectra and compared to the predictions of Spjeldvik and Fritz (1978). These comparisons show that the observed spectra agree best with the Spjeldvik and Fritz predictions that assume an O{sup +} source, at the high {ital L} boundary in their model, for oxygen with {ital Q}{le}+3 but agree better with their predictions for a solar wind source, O{sup +6}, for oxygen with {ital Q}{gt}+3 on average. As expected, O{sup +} is the dominant oxygen ion at all times in the inner magnetosphere for energies {gt}60 keV/Q. During average conditions the {ital Q}{ge}+4 ions have fluxes comparable to O{sup +3} in the {ital L}=4.5{endash}7.5 region and are about 50{percent} of the O{sup +3} fluxes in the {ital L}=3{endash}5 regions. Thus, the average O{sup +3} fluxes appear to represent a transition state between ionospheric and solar wind source oxygen. {copyright} {ital 1996 American Institute of Physics.}

  16. Angular and charge state distributions of highly charged ions scattered during low energy surface-channeling interactions with Au(110)

    SciTech Connect

    Meyer, F.W.; Folkerts, L.; Schippers, S.

    1994-10-01

    The authors have measured scattered projectile angular and charge state distributions for 3.75 keV/amu O{sup q+} (3 {le} q {le} 8) and 1.2 keV/amu Ar{sup 1+} (3 {le} q {le} 14) ions grazingly incident along the [110] and [100] directions of a Au(110) single crystal target. Scattered projectile angular distribution characteristic of surface channeling are observed. For both incident species, the dominant scattered charge fraction is neutral, which varies only by a few percent as a function of incident charge state. Significant O{sup {minus}} formation is observed, which manifests a distinct velocity threshold. For incident Ar projectiles with open L-shells, the positive scattered charge fractions, while always less than about 10%, increase linearly with increasing number of initial L-shell vacancies.

  17. Universal bounds on charged states in 2d CFT and 3d gravity

    NASA Astrophysics Data System (ADS)

    Benjamin, Nathan; Dyer, Ethan; Fitzpatrick, A. Liam; Kachru, Shamit

    2016-08-01

    We derive an explicit bound on the dimension of the lightest charged state in two dimensional conformal field theories with a global abelian symmetry. We find that the bound scales with c and provide examples that parametrically saturate this bound. We also prove that any such theory must contain a state with charge-to-mass ratio above a minimal lower bound. We comment on the implications for charged states in three dimensional theories of gravity.

  18. Resonance charge exchange between excited states in slow proton-hydrogen collisions

    SciTech Connect

    Tolstikhina, Inga Yu.; Kato, Daiji

    2010-09-15

    The theory of resonance charge exchange in slow collisions of a proton with a hydrogen atom in the excited state is developed. It extends the Firsov-Demkov theory of resonance charge exchange to the case of degenerate initial and final states. The theory is illustrated by semiclassical and quantum calculations of charge exchange cross sections between states with n=2 in parabolic and spherical coordinates. The results are compared with existing close-coupling calculations.

  19. Charge state dependence of cathodic vacuum arc ion energy andvelocity distributions

    SciTech Connect

    Rosen, Johanna; Schneider, Jochen M.; Anders, Andre

    2006-08-15

    In the literature, conflicting conclusions are reported concerning the charge state dependence of cathodic arc ion energy and velocity distributions. It appears that data from electrostatic energy analyzers indicate charge state dependence of ion energy, whereas time-of-flight methods support charge state independence of ion velocity. Here we present charge-state-resolved ion energy distributions and calculate the corresponding ion velocity distributions in aluminum vacuum arc plasma. We show that the conflicting conclusions reported in the literature for the two different characterization techniques may originate from the commonly employed data interpretation of energy and velocity, in which peak values and average values are not carefully distinguished.

  20. Physical limits for high ion charge states in pulsed discharges in vacuum

    SciTech Connect

    Yushkov, Georgy; Anders, Andre

    2008-12-23

    Short-pulse, high-current discharges in vacuum were investigated with the goal to maximize the ion charge state number. In a direct extension of previous work [Appl. Phys. Lett. 92, 041502 (2008)], the role of pulse length, rate of current rise, and current amplitude was studied. For all experimental conditions, the usable (extractable) mean ion charge state could not be pushed beyond 7+. Instead, a maximum of the mean ion charge state (about 6+ to 7+ for most cathode materials) was found for a power of 2-3 MW dissipated in the discharge gap. The maximum is the result of two opposing processes that occur when the power is increased: (i) the formation of higher ion charge states, and (ii) a greater production of neutrals (both metal and non-metal), which reduces the charge state via charge exchange collisions.

  1. Physical limits for high ion charge states in pulsed discharges in vacuum

    SciTech Connect

    Yushkov, Georgy Yu.; Anders, Andre

    2009-02-15

    Short-pulse high-current discharges in vacuum were investigated with the goal to maximize the ion charge state number. In a direct extension of previous work [G. Y. Yushkov and A. Anders, Appl. Phys. Lett. 92, 041502 (2008)], the role of pulse length, rate of current rise, and current amplitude was studied. For all experimental conditions, the usable (extractable) mean ion charge state could not be pushed beyond 7+. Instead, a maximum of the mean ion charge state (about 6+ to 7+ for most cathode materials) was found for a power of 2-3 MW dissipated in the discharge gap. The maximum is the result of two opposing processes that occur when the power is increased: (i) the formation of higher ion charge states and (ii) a greater production of neutrals (both metal and nonmetal), which reduces the charge state via charge exchange collisions.

  2. State to State and Charged Particle Kinetic Modeling of Time Filtering and Cs Addition

    SciTech Connect

    Capitelli, M.; Gorse, C.; Longo, S.; Diomede, P.; Pagano, D.

    2007-08-10

    We present here an account on the progress of kinetic simulation of non equilibrium plasmas in conditions of interest for negative ion production by using the 1D Bari code for hydrogen plasma simulation. The model includes the state to state kinetics of the vibrational level population of hydrogen molecules, plus a PIC/MCC module for the multispecies dynamics of charged particles. In particular we present new results for the modeling of two issues of great interest: the time filtering and the Cs addition via surface coverage.

  3. Charge state distributions and charge exchange cross sections of carbon in helium at 30-258 keV

    NASA Astrophysics Data System (ADS)

    Maxeiner, Sascha; Seiler, Martin; Suter, Martin; Synal, Hans-Arno

    2015-10-01

    With the introduction of helium stripping in radiocarbon (14C) accelerator mass spectrometry (AMS), higher +1 charge state yields in the 200 keV region and fewer beam losses are observed compared to nitrogen or argon stripping. To investigate the feasibility of even lower beam energies for 14C analyses the stripping characteristics of carbon in helium need to be further studied. Using two different AMS systems at ETH Zurich (myCADAS and MICADAS), ion beam transmissions of carbon ions for the charge states -1, +1, +2 and +3 were measured in the range of 258 keV down to 30 keV. The correction for beam losses and the extraction of charge state yields and charge exchange cross sections will be presented. An increase in population of the +1 charge state towards the lowest measured energies up to 75% was found as well as agreement with previous data from literature. The findings suggest that more compact radiocarbon AMS systems are possible and could provide even higher efficiency than current systems operating in the 200 keV range.

  4. Surface States and the Charge of a Dust Particle in a Plasma

    SciTech Connect

    Bronold, F. X.; Fehske, H.; Deutsch, H.; Kersten, H.

    2008-10-24

    We investigate electron and ion surface states of a negatively charged dust particle in a gas discharge and identify the charge of the particle with the electron surface density bound in the polarization-induced short-range part of the particle potential. On that scale, ions do not affect the charge. They are trapped in the shallow states of the Coulomb tail of the potential and act only as screening charges. Using orbital-motion limited electron charging fluxes and the particle temperature as an adjustable parameter, we obtain excellent agreement with experimental data.

  5. Deterministic Electrical Charge-State Initialization of Single Nitrogen-Vacancy Center in Diamond

    NASA Astrophysics Data System (ADS)

    Doi, Y.; Makino, T.; Kato, H.; Takeuchi, D.; Ogura, M.; Okushi, H.; Morishita, H.; Tashima, T.; Miwa, S.; Yamasaki, S.; Neumann, P.; Wrachtrup, J.; Suzuki, Y.; Mizuochi, N.

    2014-01-01

    Apart from applications in classical information-processing devices, the electrical control of atomic defects in solids at room temperature will have a tremendous impact on quantum devices that are based on such defects. In this study, we demonstrate the electrical manipulation of individual prominent representatives of such atomic solid-state defects, namely, the negative charge state of single nitrogen-vacancy defect centers (NV-) in diamond. We experimentally demonstrate, deterministic, purely electrical charge-state initialization of individual NV centers. The NV centers are placed in the intrinsic region of a p-i-n diode structure that facilitates the delivery of charge carriers to the defect for charge-state switching. The charge-state dynamics of a single NV center were investigated by time-resolved measurements and a nondestructive single-shot readout of the charge state. Fast charge-state switching rates (from negative to neutrally charged defects), which are greater than 0.72 ± 0.10 μs-1, were realized. Furthermore, in no-operation mode, the realized charge states were stable for presumably much more than 0.45 s. We believe that the results obtained are useful not only for ultrafast electrical control of qubits, long T2 quantum memory, and quantum sensors associated with single NV centers but also for classical memory devices based on single atomic storage bits working under ambient conditions.

  6. CHARGE STATE EVOLUTION IN THE SOLAR WIND. II. PLASMA CHARGE STATE COMPOSITION IN THE INNER CORONA AND ACCELERATING FAST SOLAR WIND

    SciTech Connect

    Landi, E.; Gruesbeck, J. R.; Lepri, S. T.; Zurbuchen, T. H.; Fisk, L. A.

    2012-12-10

    In the present work, we calculate the evolution of the charge state distribution within the fast solar wind. We use the temperature, density, and velocity profiles predicted by Cranmer et al. to calculate the ionization history of the most important heavy elements in the solar corona and solar wind: C, N, O, Ne, Mg, Si, S, and Fe. The evolution of each charge state is calculated from the source region in the lower chromosphere to the final freeze-in point. We show that the solar wind velocity causes the plasma to experience significant departures from equilibrium at very low heights, well inside the field of view (within 0.6 R{sub sun} from the solar limb) of nearly all the available remote-sensing instrumentation, significantly affecting observed spectral line intensities. We also study the evolution of charge state ratios with distance from the source region, and the temperature they indicate if ionization equilibrium is assumed. We find that virtually every charge state from every element freezes in at a different height, so that the definition of freeze-in height is ambiguous. We also find that calculated freeze-in temperatures indicated by charge state ratios from in situ measurements have little relation to the local coronal temperature of the wind source region, and stop evolving much earlier than their correspondent charge state ratio. We discuss the implication of our results on plasma diagnostics of coronal holes from spectroscopic measurements as well as on theoretical solar wind models relying on coronal temperatures.

  7. State of charge monitoring methods for vanadium redox flow battery control

    NASA Astrophysics Data System (ADS)

    Skyllas-Kazacos, Maria; Kazacos, Michael

    2011-10-01

    During operation of redox flow batteries, differential transfer of ions and electrolyte across the membrane and gassing side reactions during charging, can lead to an imbalance between the two half-cells that results in loss of capacity. This capacity loss can be corrected by either simple remixing of the two solutions, or by chemical or electrochemical rebalancing. In order to develop automated electrolyte management systems therefore, the state-of-charge of each half-cell electrolyte needs to be known. In this study, two state-of-charge monitoring methods are investigated for use in the vanadium redox flow battery. The first method utilizes conductivity measurements to independently measure the state-of-charge of each half-cell electrolyte. The second method is based on spectrophotometric principles and uses the different colours of the charged and discharged anolyte and catholyte to monitor system balance and state-of charge of each half-cell of the VRB during operation.

  8. Charge-state dynamics in electrostatic force spectroscopy.

    PubMed

    Ondráček, Martin; Hapala, Prokop; Jelínek, Pavel

    2016-07-01

    We present a numerical model that allows us to study the response of an oscillating probe in electrostatic force spectroscopy to charge switching in quantum dots at various time scales. The model provides more insight into the behavior of frequency shift and dissipated energy under different scanning conditions when measuring a temporarily charged quantum dot on a surface. Namely, we analyze the dependence of the frequency shift, the dissipated energy, and their fluctuations on the resonance frequency of the tip and on the electron tunneling rates across the tip-quantum dot and quantum dot-sample junctions. We discuss two complementary approaches to simulating the charge dynamics, a stochastic and a deterministic one. In addition, we derive analytic formulas valid for small amplitudes, describing relations between the frequency shift, dissipated energy, and the characteristic rates driving the charging and discharging processes. PMID:27242270

  9. Charge-state dynamics in electrostatic force spectroscopy

    NASA Astrophysics Data System (ADS)

    Ondráček, Martin; Hapala, Prokop; Jelínek, Pavel

    2016-07-01

    We present a numerical model that allows us to study the response of an oscillating probe in electrostatic force spectroscopy to charge switching in quantum dots at various time scales. The model provides more insight into the behavior of frequency shift and dissipated energy under different scanning conditions when measuring a temporarily charged quantum dot on a surface. Namely, we analyze the dependence of the frequency shift, the dissipated energy, and their fluctuations on the resonance frequency of the tip and on the electron tunneling rates across the tip–quantum dot and quantum dot–sample junctions. We discuss two complementary approaches to simulating the charge dynamics, a stochastic and a deterministic one. In addition, we derive analytic formulas valid for small amplitudes, describing relations between the frequency shift, dissipated energy, and the characteristic rates driving the charging and discharging processes.

  10. Influence of argon and oxygen on charge-state-resolved ion energydistributions of filtered aluminum arcs

    SciTech Connect

    Rosen, Johanna; Anders, Andre; Mraz, Stanislav; Atiser, Adil; Schneider, Jochen M.

    2006-03-23

    The charge-state-resolved ion energy distributions (IEDs) in filtered aluminum vacuum arc plasmas were measured and analyzed at different oxygen and argon pressures in the range 0.5 8.0 mTorr. A significant reduction of the ion energy was detected as the pressure was increased, most pronounced in an argon environment and for the higher charge states. The corresponding average charge state decreased from 1.87 to 1.0 with increasing pressure. The IEDs of all metal ions in oxygen were fitted with shifted Maxwellian distributions. The results show that it is possible to obtain a plasma composition with a narrow charge-state distribution as well as a narrow IED. These data may enable tailoring thin-film properties through selecting growth conditions that are characterized by predefined charge state and energy distributions.

  11. Interplay between strain, defect charge state, and functionality in complex oxides

    NASA Astrophysics Data System (ADS)

    Aschauer, Ulrich; Spaldin, Nicola A.

    2016-07-01

    We use first-principles calculations to investigate the interplay between strain and the charge state of point defect impurities in complex oxides. Our work is motivated by recent interest in using defects as active elements to provide novel functionality in coherent epitaxial films. Using oxygen vacancies as model point defects, and CaMnO3 and MnO as model materials, we calculate the changes in internal strain caused by changing the charge state of the vacancies, and conversely the effect of strain on charge-state stability. Our results show that the charge state is a degree of freedom that can be used to control the interaction of defects with strain and hence the concentration and location of defects in epitaxial films. We propose the use of field-effect gating to reversibly change the charge state of defects and hence the internal strain and corresponding strain-induced functionalities.

  12. Absolute spectrum and charge ratio of cosmic ray muons in the energy region from 0.2 GeV to 100 GeV at 600 m above sea level

    NASA Technical Reports Server (NTRS)

    De Pascale, M. P.; Morselli, A.; Picozza, P.; Golden, R. L.; Grimani, C.; Kimbell, B. L.; Stephens, S. A.; Stochaj, S. J.; Webber, W. R.; Basini, G.

    1993-01-01

    We have determined the momentum spectrum and charge ratio of muons in the region from 250 MeV/c to 100 GeV/c using a superconducting magnetic spectrometer. The absolute differential spectrum of muons obtained in this experiment at 600 m above sea level is in good agreement with the previous measurements at sea level. The differential spectrum can be represented by a power law with a varying index, which is consistent with zero below 450 MeV/c and steepens to a value of -2.7 +/- 0.1 between 20 and 100 GeV/c. The integral f1ux of muons measured in this experiment span a very large range of momentum and is in excellent agreement with the earlier results. The positive to negative muon ratio appears to be constant in the entire momentum range covered in this experiment within the errors and the mean value is 1.220 +/- 0.044. The absolute momentum spectrum and the charge ratio measured in this experiment are also consistent with the theoretical expectations. This is the only experiment which covers a wide range of nearly three decades in momentum from a very low momentum.

  13. Basophile: Accurate Fragment Charge State Prediction Improves Peptide Identification Rates

    SciTech Connect

    Wang, Dong; Dasari, Surendra; Chambers, Matthew C.; Holman, Jerry D.; Chen, Kan; Liebler, Daniel; Orton, Daniel J.; Purvine, Samuel O.; Monroe, Matthew E.; Chung, Chang Y.; Rose, Kristie L.; Tabb, David L.

    2013-03-07

    In shotgun proteomics, database search algorithms rely on fragmentation models to predict fragment ions that should be observed for a given peptide sequence. The most widely used strategy (Naive model) is oversimplified, cleaving all peptide bonds with equal probability to produce fragments of all charges below that of the precursor ion. More accurate models, based on fragmentation simulation, are too computationally intensive for on-the-fly use in database search algorithms. We have created an ordinal-regression-based model called Basophile that takes fragment size and basic residue distribution into account when determining the charge retention during CID/higher-energy collision induced dissociation (HCD) of charged peptides. This model improves the accuracy of predictions by reducing the number of unnecessary fragments that are routinely predicted for highly-charged precursors. Basophile increased the identification rates by 26% (on average) over the Naive model, when analyzing triply-charged precursors from ion trap data. Basophile achieves simplicity and speed by solving the prediction problem with an ordinal regression equation, which can be incorporated into any database search software for shotgun proteomic identification.

  14. NO adsorption and dissociation on palladium clusters: The importance of charged state and metal doping

    NASA Astrophysics Data System (ADS)

    Gao, Yang; Zhang, Li Mei; Kong, Chun Cai; Yang, Zhi Mao; Chen, Yong Mei

    2016-08-01

    The NO adsorption and dissociation on neutral, charged and Ni-doped Pd13 clusters were studied by using density functional calculations. Our results revealed that NO always prefers to adsorb on the hollow site rather than the top or bridge sites. However, the charge state and Ni doping remarkably influence NO adsorption energy, dissociation barrier and reaction energy. The reaction on Pd13- has the lowest energy barrier and largest reaction energy. The Hirshfeld charge analysis discloses that the origin of the catalytic activity difference is the charge transfer from clusters to NO in the metastable NO adsorption state.

  15. Low charge state heavy ion production with sub-nanosecond laser.

    PubMed

    Kanesue, T; Kumaki, M; Ikeda, S; Okamura, M

    2016-02-01

    We have investigated laser ablation plasma of various species using nanosecond and sub-nanosecond lasers for both high and low charge state ion productions. We found that with sub-nanosecond laser, the generated plasma has a long tail which has low charge state ions determined by an electrostatic ion analyzer even under the laser irradiation condition for highly charged ion production. This can be caused by insufficient laser absorption in plasma plume. This property might be suitable for low charge state ion production. We used a nanosecond laser and a sub-nanosecond laser for low charge state ion production to investigate the difference of generated plasma using the Zirconium target. PMID:26931977

  16. Measurement of absolute transition frequencies of {sup 87}Rb to nS and nD Rydberg states by means of electromagnetically induced transparency

    SciTech Connect

    Mack, Markus; Karlewski, Florian; Hattermann, Helge; Hoeckh, Simone; Jessen, Florian; Cano, Daniel; Fortagh, Jozsef

    2011-05-15

    We report the measurement of absolute excitation frequencies of {sup 87}Rb to nS and nD Rydberg states. The Rydberg transition frequencies are obtained by observing electromagnetically induced transparency on a rubidium vapor cell. The accuracy of the measurement of each state is < or approx. 1 MHz, which is achieved by frequency stabilizing the two diode lasers employed for the spectroscopy to a frequency comb and a frequency comb calibrated wavelength meter, respectively. Based on the spectroscopic data we determine the quantum defects of {sup 87}Rb, and compare it with previous measurements on {sup 85}Rb. We determine the ionization frequency from the 5S{sub 1/2}(F=1) ground state of {sup 87}Rb to 1010.029 164 6(3)THz, providing the binding energy of the ground state with an accuracy improved by two orders of magnitude.

  17. Basophile: Accurate Fragment Charge State Prediction Improves Peptide Identification Rates

    DOE PAGESBeta

    Wang, Dong; Dasari, Surendra; Chambers, Matthew C.; Holman, Jerry D.; Chen, Kan; Liebler, Daniel; Orton, Daniel J.; Purvine, Samuel O.; Monroe, Matthew E.; Chung, Chang Y.; et al

    2013-03-07

    In shotgun proteomics, database search algorithms rely on fragmentation models to predict fragment ions that should be observed for a given peptide sequence. The most widely used strategy (Naive model) is oversimplified, cleaving all peptide bonds with equal probability to produce fragments of all charges below that of the precursor ion. More accurate models, based on fragmentation simulation, are too computationally intensive for on-the-fly use in database search algorithms. We have created an ordinal-regression-based model called Basophile that takes fragment size and basic residue distribution into account when determining the charge retention during CID/higher-energy collision induced dissociation (HCD) of chargedmore » peptides. This model improves the accuracy of predictions by reducing the number of unnecessary fragments that are routinely predicted for highly-charged precursors. Basophile increased the identification rates by 26% (on average) over the Naive model, when analyzing triply-charged precursors from ion trap data. Basophile achieves simplicity and speed by solving the prediction problem with an ordinal regression equation, which can be incorporated into any database search software for shotgun proteomic identification.« less

  18. Contribution of Charged Groups to the Enthalpic Stabilization of the Folded States of Globular Proteins

    PubMed Central

    Dadarlat, Voichita M.; Post, Carol Beth

    2016-01-01

    In this paper we use the results from all atom MD simulations of proteins and peptides to assess individual contribution of charged atomic groups to the enthalpic stability of the native state of globular proteins and investigate how the distribution of charged atomic groups in terms of solvent accessibility relates to protein enthalpic stability. The contributions of charged groups is calculated using a comparison of nonbonded interaction energy terms from equilibrium simulations of charged amino acid dipeptides in water (the “unfolded state”) and charged amino acids in globular proteins (the “folded state”). Contrary to expectation, the analysis shows that many buried, charged atomic groups contribute favorably to protein enthalpic stability. The strongest enthalpic contributions favoring the folded state come from the carboxylate (COO−) groups of either Glu or Asp. The contributions from Arg guanidinium groups are generally somewhat stabilizing, while NH3+ groups from Lys contribute little toward stabilizing the folded state. The average enthalpic gain due to the transfer of a methyl group in an apolar amino acid from solution to the protein interior is described for comparison. Notably, charged groups that are less exposed to solvent contribute more favorably to protein native-state enthalpic stability than charged groups that are solvent exposed. While solvent reorganization/release has favorable contributions to folding for all charged atomic groups, the variation in folded state stability among proteins comes mainly from the change in the nonbonded interaction energy of charged groups between the unfolded and folded states. A key outcome is that the calculated enthalpic stabilization is found to be inversely proportional to the excess charge density on the surface, in support of an hypothesis proposed previously. PMID:18303881

  19. The influence of the beam charge state on the analytical calculation of RBS and ERDA spectra

    NASA Astrophysics Data System (ADS)

    Barradas, Nuno P.; Kosmata, Marcel; Hanf, Daniel; Munnik, Frans

    2016-03-01

    Analytical codes dedicated to the analysis of Ion Beam Analysis data rely on the accuracy of both the calculations and of basic data such as scattering cross sections and stopping powers. So far, the effect of the beam charge state of the incoming beam has been disregard by general purpose analytical codes such as NDF. In fact, the codes implicitly assume that the beam always has the equilibrium charge state distribution, by using tabulated stopping power values e.g. from SRIM, which are in principle valid for the effective charge state. The dependence of the stopping power with the changing charge state distribution is ignored. This assumption is reasonable in most cases, but for high resolution studies the actual change of the charge state distribution from the initial beam charge state towards equilibrium as it enters and traverses the sample must be taken into account, as it influences the shape of the observed data. In this work, we present an analytical calculation, implemented in NDF, that takes this effect into account. For elastic recoil detection analysis (ERDA), the changing charge state distribution of the recoils can also be taken into account. We apply the calculation to the analysis of experimental high depth resolution ERDA data for various oxide layers collected using a magnetic spectrometer.

  20. Theory for charge states of energetic oxygen ions in the earth's radiation belts

    NASA Technical Reports Server (NTRS)

    Spjeldvik, W. N.; Fritz, T. A.

    1978-01-01

    Fluxes of geomagnetically trapped energetic oxygen ions have been studied in detail. Ion distributions in radial locations below the geostationary orbit, energy spectra between 1 keV and 100 MeV, and the distribution over charge states have been computed for equatorially mirroring ions. Both ionospheric and solar wind oxygen ion sources have been considered, and it is found that the charge state distributions in the interior of the radiation belts are largely independent of the charge state characteristics of the sources. In the MeV range, oxygen ions prove to be a more sensitive probe for radiation belt dynamics than helium ions and protons.

  1. Evidence of Delocalization in Charge-Transfer State Manifold for Donor:Acceptor Organic Photovoltaics.

    PubMed

    Guan, Zhiqiang; Li, Ho-Wa; Zhang, Jinfeng; Cheng, Yuanhang; Yang, Qingdan; Lo, Ming-Fai; Ng, Tsz-Wai; Tsang, Sai-Wing; Lee, Chun-Sing

    2016-08-24

    How charge-transfer states (CTSs) assist charge separation of a Coulombically bound exciton in organic photovoltaics has been a hot topic. It is believed that the delocalization feature of a CTS plays a crucial role in the charge separation process. However, the delocalization of the "hot" and the "relaxed" CTSs is still under debate. Here, with a novel frequency dependent charge-modulated electroabsorption spectroscopy (CMEAS) technique, we elucidate clearly that both "hot" and "relaxed" CTSs are loosely bound and delocalized states. This is confirmed by comparing the CMEAS results of CTSs with those of localized polaron states. Our results reveal the role of CTS delocalization on charge separation and indicate that no substantial delocalization gradient exists in CTSs. PMID:27482867

  2. Determining charge state of graphene vacancy by noncontact atomic force microscopy and first-principles calculations

    NASA Astrophysics Data System (ADS)

    Liu, Y.; Weinert, M.; Li, L.

    2015-01-01

    Graphene vacancies are engineered for novel functionalities, however, the charge state of these defects, the key parameter that is vital to charge transfer during chemical reactions and carrier scattering, is generally unknown. Here, we carried out atomic resolution imaging of graphene vacancy defects created by Ar plasma using noncontact atomic force microscopy, and made the first determination of their charge state by local contact potential difference measurements. Combined with density functional theory calculations, we show that graphene vacancies are typically positively charged, with size-dependent charge states that are not necessarily integer-valued. These findings provide new insights into carrier scattering by vacancy defects in graphene, as well as its functionalization for chemical sensing and catalysis, and underline the tunability of these functions by controlling the size of vacancy defect.

  3. Role of metastable charge states in a quantum-dot spin-qubit readout

    NASA Astrophysics Data System (ADS)

    Mason, J. D.; Studenikin, S. A.; Kam, A.; Wasilewski, Z. R.; Sachrajda, A. S.; Kycia, J. B.

    2015-09-01

    Readout of a spin qubit in a lateral gate-defined quantum-dot device typically involves a charge detector and a spin-to-charge conversion technique employing spin blockade. We investigate alternative mechanisms for spin-to-charge conversion involving metastable excited charge states made possible by an asymmetry in the tunneling rates to the leads. This technique is used to observe Landau-Zener-Stückelberg oscillations of the S -T+ qubit within the (1,0) ground state region of the charge stability diagram. The oscillations are π phase shifted relative to those detected using the standard technique and display a nonsinusoidal waveform due to the increased relaxation time from the metastable state.

  4. A high-charge-state plasma neutralizer for an energetic H/sup -/ beam

    SciTech Connect

    Schlachter, A.S.; Leung, K.N.; Stearns, J.W.; Olson, R.E.

    1986-10-01

    A high-charge-state plasma neutralizer for a beam of energetic H/sup -/ ions offers the potential of high optimum neutralization efficiency (approx.85%) relative to a gas target (50 to 60%), and considerably reduced target thickness. We have calculated cross sections for charge-changing interactions of fast H/sup -/ and H/sup 0/ in collision with highly charged ions using a semiclassical model for H/sup -/, and the Classical-Trajectory Monte Carlo method plus Born calculations, to obtain correct asymptotic cross sections in the high-energy limit. Charge-state fractions as a function of plasma line density, and f/sub 0//sup max/, the maximum H/sup 0/ fraction, are calculated using these cross sections; we find that f/sub 0//sup mx/ approx. = 85% for ion charge states in the range 1+ to 10+, and that target ion line density for f/sub 0//sup max/ decreases approximately as the square of the plasma ion charge state. The maximum neutral fraction is also high for a partially ionized plasma. We have built a small multicusp plasma generator to use a a plasma neutralizer; preliminary results show that the plasma contains argon ions with an average charge state between 2+ and 3+ for a steady-state discharge.

  5. 20 CFR 416.2161 - Charges to States.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... Employees' Benefits SOCIAL SECURITY ADMINISTRATION SUPPLEMENTAL SECURITY INCOME FOR THE AGED, BLIND, AND... eligibility determination agreement. A State with which we have an agreement to make Medicaid eligibility... application information for a State causes us additional cost, the State must pay half of that additional...

  6. Charge density stabilised local electron spin pair states in insulating polymers

    SciTech Connect

    Serra, S.; Dissado, L. A.

    2014-12-14

    A model is presented that addresses the energy stability of localized electron states in insulating polymers with respect to delocalized free electron-like states at variable charge densities. The model was derived using an effective Hamiltonian for the total energy of electrons trapped in large polarons and spin-paired bipolarons, which includes the electrostatic interaction between charges that occurs when the charge density exceeds the infinite dilution limit. The phase diagram of the various electronic states with respect to the charge density is derived using parameters determined from experimental data for polyethylene, and it is found that a phase transition from excess charge in the form of stable polarons to a stable state of bipolarons with charge = 2 and spin number S = 0 is predicted for a charge density between 0.2 C/m{sup 3} and ∼2 C/m{sup 3}. This transition is consistent with a change from low mobility charge transport to charge transport in the form of pulses with a mobility orders of magnitude higher that has been observed in several insulating polymers.

  7. Charge states of energetic oxygen and sulfur ions in Jupiter's magnetosphere

    NASA Astrophysics Data System (ADS)

    Clark, G.; Mauk, B. H.; Paranicas, C.; Kollmann, P.; Smith, H. T.

    2016-03-01

    Pitch angle distributions of proton and energetic heavy ion fluxes near Europa's orbit have been measured by the Galileo Energetic Particles Detector (EPD). At similar energies, these distributions have important differences. If their source and transport processes are similar, as we hypothesize here, then it is difficult to reconcile their different pitch angle distributions. By looking at the same question, other researchers have proposed that the heavies are multiply charged, leading to differences in how the particles are lost. This could not be confirmed directly with EPD because that detector does not separate heavy ion measurements by charge state. However, indirect analyses of the data have extracted the charge state of a few sulfur events. We present here a complete list of ion injections observed with EPD over the whole mission. Energetic sulfur and oxygen charge states can be inferred through a dispersion analysis of dynamic injections that makes use of the charge-dependent nature of the gradient-curvature azimuthal drift. We find that sulfur is predominantly multiply charged, whereas oxygen is more evenly distributed between singly and doubly charged states. In addition to current theories on energetic heavy ion transport near the Europa region, we propose that charge gain for the oxygen ions (electron stripping) may play an important role in the character of energetic particles in that region.

  8. Charge state distribution and emission characteristics in a table top reflex discharge—Effect of ion confinement and electrons accelerated across the sheath

    SciTech Connect

    Kumar, Deepak Englesbe, Alexander; Parman, Matthew; Stutman, Dan; Finkenthal, Michael

    2015-11-15

    Tabletop reflex discharges in a Penning geometry have many applications including ion sources and eXtreme Ultra-Violet (XUV) sources. The presence of primary electrons accelerated across the cathode sheaths is responsible for the distribution of ion charge states and of the unusually high XUV brightness of these plasmas. Absolutely calibrated space resolved XUV spectra from a table top reflex discharge operating with Al cathodes and Ne gas are presented. The spectra are analyzed with a new and complete model for ion charge distribution in similar reflex discharges. The plasma in the discharge was found to have a density of ∼10{sup 18 }m{sup −3} with a significant fraction >0.01 of fast primary electrons. The implications of the new model on the ion states achievable in a tabletop reflex plasma discharge are also discussed.

  9. Charge state distribution and emission characteristics in a table top reflex discharge - Effect of ion confinement and electrons accelerated across the sheath

    SciTech Connect

    Kumar, Deepak; Englesbe, Alexander; Parman, Matthew; Stutman, Dan; Finkenthal, Michael

    2015-11-05

    Tabletop reflex discharges in a Penning geometry have many applications including ion sources and eXtreme Ultra-Violet (XUV) sources. The presence of primary electrons accelerated across the cathode sheaths is responsible for the distribution of ion charge states and of the unusually high XUV brightness of these plasmas. Absolutely calibrated space resolved XUV spectra from a table top reflex discharge operating with Al cathodes and Ne gas are presented. The spectra are analyzed with a new and complete model for ion charge distribution in similar reflex discharges. The plasma in the discharge was found to have a density of ~1018m–3 with a significant fraction >0.01 of fast primary electrons. As a result, the implications of the new model on the ion states achievable in a tabletop reflex plasma discharge are also discussed.

  10. Charge state distribution and emission characteristics in a table top reflex discharge - Effect of ion confinement and electrons accelerated across the sheath

    DOE PAGESBeta

    Kumar, Deepak; Englesbe, Alexander; Parman, Matthew; Stutman, Dan; Finkenthal, Michael

    2015-11-05

    Tabletop reflex discharges in a Penning geometry have many applications including ion sources and eXtreme Ultra-Violet (XUV) sources. The presence of primary electrons accelerated across the cathode sheaths is responsible for the distribution of ion charge states and of the unusually high XUV brightness of these plasmas. Absolutely calibrated space resolved XUV spectra from a table top reflex discharge operating with Al cathodes and Ne gas are presented. The spectra are analyzed with a new and complete model for ion charge distribution in similar reflex discharges. The plasma in the discharge was found to have a density of ~1018m–3 withmore » a significant fraction >0.01 of fast primary electrons. As a result, the implications of the new model on the ion states achievable in a tabletop reflex plasma discharge are also discussed.« less

  11. Charge state distribution and emission characteristics in a table top reflex discharge—Effect of ion confinement and electrons accelerated across the sheath

    NASA Astrophysics Data System (ADS)

    Kumar, Deepak; Englesbe, Alexander; Parman, Matthew; Stutman, Dan; Finkenthal, Michael

    2015-11-01

    Tabletop reflex discharges in a Penning geometry have many applications including ion sources and eXtreme Ultra-Violet (XUV) sources. The presence of primary electrons accelerated across the cathode sheaths is responsible for the distribution of ion charge states and of the unusually high XUV brightness of these plasmas. Absolutely calibrated space resolved XUV spectra from a table top reflex discharge operating with Al cathodes and Ne gas are presented. The spectra are analyzed with a new and complete model for ion charge distribution in similar reflex discharges. The plasma in the discharge was found to have a density of ˜1018 m-3 with a significant fraction >0.01 of fast primary electrons. The implications of the new model on the ion states achievable in a tabletop reflex plasma discharge are also discussed.

  12. A model for electrophoretic transport of charged particles through membrane before steady state

    NASA Astrophysics Data System (ADS)

    de Souza, Tatiana Miranda; Fragoso, Viviane Muniz da Silva; Cruz, Frederico Alan de Oliveira

    2015-12-01

    In this paper, we are presenting a model for electrophoretic motion of a charged particle through the membrane before it reaches the steady state, based on concepts of Physics. Some results from analysis of the model are discussed.

  13. Recoil ion charge state distribution following the beta(sup +) decay of {sup 21}Na

    SciTech Connect

    Scielzo, Nicholas D.; Freedman, Stuart J.; Fujikawa, Brian K.; Vetter, Paul A.

    2003-01-03

    The charge state distribution following the positron decay of 21Na has been measured, with a larger than expected fraction of the daughter 21Ne in positive charge states. No dependence on either the positron or recoil nucleus energy is observed. The data is compared to a simple model based on the sudden approximation. Calculations suggest a small but important contribution from recoil ionization has important consequences for precision beta decay correlation experiments detecting recoil ions.

  14. Absolute determination of charge-coupled device quantum detection efficiency using Si K-edge x-ray absorption fine structure

    SciTech Connect

    Dunn, J; Steel, A B

    2012-05-06

    We report a method to determine the quantum detection efficiency and the absorbing layers on a front-illuminated charge-coupled device (CCD). The CCD under study, as part of a crystal spectrometer, measures intense continuum x-ray emission from a picosecond laser-produced plasma and spectrally resolves the Si K-edge x-ray absorption fine structure features due to the electrode gate structure of the device. The CCD response across the Si K-edge shows a large discontinuity as well as a number of oscillations that are identified individually and uniquely from Si, SiO{sub 2}, and Si{sub 3}N{sub 4} layers. From the spectral analysis of the structure and K-edge discontinuity, the active layer thickness and the different absorbing layers thickness can be determined precisely. A precise CCD detection model from 0.2-10 keV can be deduced from this highly sensitive technique.

  15. Teaching Absolute Value Meaningfully

    ERIC Educational Resources Information Center

    Wade, Angela

    2012-01-01

    What is the meaning of absolute value? And why do teachers teach students how to solve absolute value equations? Absolute value is a concept introduced in first-year algebra and then reinforced in later courses. Various authors have suggested instructional methods for teaching absolute value to high school students (Wei 2005; Stallings-Roberts…

  16. ARCHITECTURE OF A CHARGE-TRANSFER STATE REGULATING LIGHT HARVESTING IN A PLANT ANTENNA PROTEIN

    SciTech Connect

    Fleming, Graham; Ahn, Tae Kyu; Avenson, Thomas J.; Ballottari, Matteo; Cheng, Yuan-Chung; Niyogi, Krishna K.; Bassi, Roberto; Fleming, Graham R.

    2008-04-02

    Energy-dependent quenching of excess absorbed light energy (qE) is a vital mechanism for regulating photosynthetic light harvesting in higher plants. All of the physiological characteristics of qE have been positively correlated with charge-transfer between coupled chlorophyll and zeaxanthin molecules in the light-harvesting antenna of photosystem II (PSII). In this work, we present evidence for charge-transfer quenching in all three of the individual minor antenna complexes of PSII (CP29, CP26, and CP24), and we conclude that charge-transfer quenching in CP29 involves a de-localized state of an excitonically coupled chlorophyll dimer. We propose that reversible conformational changes in CP29 can `tune? the electronic coupling between the chlorophylls in this dimer, thereby modulating the energy of the chlorophylls-zeaxanthin charge-transfer state and switching on and off the charge-transfer quenching during qE.

  17. Ionic charge state measurements during He(+)-rich solar particle events

    NASA Technical Reports Server (NTRS)

    Hovestadt, D.; Klecker, B.; Scholer, M.; Gloeckler, G.

    1984-01-01

    Ionic charge state measurements of carbon, oxygen, and iron in He(+)-rich energetic particle events are presented. The data have been obtained with the Max-Planck-Institut/University of Maryland sensor system on the ISEE 3 spacecraft. The ionic charge states cannot be explained in terms of a model in which the coronal temperature determines a charge equilibrium which is subsequently frozen-in nor in terms of charge exchange during transition through coronal matter after acceleration. It is concluded that the acceleration and probably also the injection process is biased against particles with high mass-to-charge ratios. The plasma injected into the acceleration process must consist of material of cold (not greater than 8.5 x 10 to the 4th K) as well as hot (2.5 x 10 to the 6th K) origin. The cold material must be more abundant than the hot material.

  18. Charge-state-dependent energy loss of slow ions. II. Statistical atom model

    NASA Astrophysics Data System (ADS)

    Wilhelm, Richard A.; Möller, Wolfhard

    2016-05-01

    A model for charge-dependent energy loss of slow ions is developed based on the Thomas-Fermi statistical model of atoms. Using a modified electrostatic potential which takes the ionic charge into account, nuclear and electronic energy transfers are calculated, the latter by an extension of the Firsov model. To evaluate the importance of multiple collisions even in nanometer-thick target materials we use the charge-state-dependent potentials in a Monte Carlo simulation in the binary collision approximation and compare the results to experiment. The Monte Carlo results reproduce the incident charge-state dependence of measured data well [see R. A. Wilhelm et al., Phys. Rev. A 93, 052708 (2016), 10.1103/PhysRevA.93.052708], even though the experimentally observed charge exchange dependence is not included in the model.

  19. High-sensitivity single NV magnetometry by spin-to-charge state mapping

    NASA Astrophysics Data System (ADS)

    Jaskula, Jean-Christophe; Shields, Brendan; Bauch, Erik; Lukin, Mikhail; Walsworth, Ronald; Trifonov, Alexei

    2015-05-01

    Nitrogen-Vacancy (NV) centers in diamond are atom-like quantum system in a solid state matrix whom its structure allows optical readout of the electronic spin. However, the optimal duration of optical readout is limited by a singlet state lifetime making single shot spin readout out of reach. On the other side, the NV center charge state readout can be extremely efficient (up to 99% fidelity) by using excitation at 594 nm. We will present a new method of spin readout utilizing a spin-depending photoionization process to map the electronic spin state of the NV onto the its charge state. Moreover, pre-selection on the charged state allows to minimize data acquisition time. This scheme improves single NV AC magnetometry by a factor of 5 and will benefit other single NV center experiments as well.

  20. A Summary of Recent Experimental Research on Ion Energy and Charge States of Pulsed Vacuum Arcs

    SciTech Connect

    Oks, Efim M.; Yushkov, Georgy Yu.; Anders, Andre

    2008-06-16

    The paper reviews the results of vacuum arc experimental investigations made collaboratively by research groups from Berkeley and Tomsk over the last two years, i.e. since the last ISDEIV in 2006. Vacuum arc plasma of various metals was produced in pulses of a few hundred microseconds duration, and the research focussed on three topics: (i) the energy distribution functions for different ion charge states, (ii) the temporal development of the ion charge state distribution, and (iii) the evolution of the mean directed ion velocities during plasma expansion. A combined quadruple mass-to-charge and energy ana-lyzer (EQP by HIDEN Ltd) and a time-of-flight spectrometer were employed. Cross-checking data by those complimen-tary techniques helped to avoid possible pitfalls in interpre-tation. It was found that the ion energy distribution func-tions in the plasma were independent of the ion charge state, which implies that the energy distribution on a substrate are not equal to due to acceleration in the substrate's sheath. In pulsed arc mode, the individual ion charge states fractions showed changes leading to a decrease of the mean charge state toward a steady-state value. This decrease can be re-duced by lower arc current, higher pulse repetition rate and reduced length of the discharge gap. It was also found that the directed ion velocity slightly decreased as the plasma expanded into vacuum.

  1. Temporal development of ion beam mean charge state in pulsed vacuum arc ion sources

    SciTech Connect

    Oks, E. M.; Yushkov, G. Yu.; Anders, A.

    2008-02-15

    Vacuum arc ion sources, commonly also known as 'Mevva' ion sources, are used to generate intense pulsed metal ion beams. It is known that the mean charge state of the ion beam lies between 1 and 4, depending on cathode material, arc current, arc pulse duration, presence or absence of magnetic field at the cathode, as well as background gas pressure. A characteristic of the vacuum arc ion beam is a significant decrease in ion charge state throughout the pulse. This decrease can be observed up to a few milliseconds, until a ''noisy'' steady-state value is established. Since the extraction voltage is constant, a decrease in the ion charge state has a proportional impact on the average ion beam energy. This paper presents results of detailed investigations of the influence of arc parameters on the temporal development of the ion beam mean charge state for a wide range of cathode materials. It is shown that for fixed pulse duration, the charge state decrease can be reduced by lower arc current, higher pulse repetition rate, and reduction of the distance between cathode and extraction region. The latter effect may be associated with charge exchange processes in the discharge plasma.

  2. High energy implantation with high-charge-state ions in a vacuum arc ion implanter

    SciTech Connect

    Oks, E.M. |; Anders, A.; Brown, I.G.; Dickinson, M.R.; MacGill, R.A.

    1996-08-01

    Ion implantation energy can in principal be increased by increasing the charge states of the ions produced by the ion source rather than by increasing the implanter operating voltage, providing an important savings in cost and size of the implanter. In some recent work the authors have shown that the charge states of metal ions produced in a vacuum arc ion source can be elevated by a strong magnetic field. In general, the effect of both high arc current and high magnetic field is to push the distribution to higher charge states--the mean ion charge state is increased and new high charge states are formed. The effect is significant for implantation application--the mean ion energy can be about doubled without change in extraction voltage. Here they describe the ion source modifications, the results of time-of-flight measurements of ion charge state distributions, and discuss the use and implications of this technique as a means for doing metal iron implantation in the multi-hundreds of keV ion energy range.

  3. Temporal Development of Ion Beam Mean Charge State in PulsedVacuum Arc Ion Sources

    SciTech Connect

    Oks, Efim M.; Yushkov, Georgy Yu.; Anders, Andre

    2007-06-21

    Vacuum arc ion sources, commonly also known as "Mevva" ionsources, are used to generate intense pulsed metal ion beams. It is knownthat the mean charge state of the ion beam lies between 1 and 4,depending on cathode material, arc current, arc pulse duration, presenceor absence of magnetic field at the cathode, as well background gaspressure. A characteristic of the vacuum arc ion beam is a significantdecrease in ion charge state throughout the pulse. This decrease can beobserved up to a few milliseconds, until a "noisy" steady-state value isestablished. Since the extraction voltage is constant, a decrease in theion charge state has a proportional impact on the average ion beamenergy. This paper presents results of detailed investigations of theinfluence of arc parameters on the temporal development of the ion beammean charge state for a wide range of cathode materials. It is shown thatfor fixed pulse duration, the charge state decrease can be reduced bylower arc current, higher pulse repetition rate, and reduction of thedistance between cathode and extraction region. The latter effect may beassociated with charge exchange processes in the dischargeplasma.

  4. Heavy ion charge-state distribution effects on energy loss in plasmas

    NASA Astrophysics Data System (ADS)

    Barriga-Carrasco, Manuel D.

    2013-10-01

    According to dielectric formalism, the energy loss of the heavy ion depends on its velocity and its charge density. Also, it depends on the target through its dielectric function; here the random phase approximation is used because it correctly describes fully ionized plasmas at any degeneracy. On the other hand, the Brandt-Kitagawa (BK) model is employed to depict the projectile charge space distribution, and the stripping criterion of Kreussler is used to determine its mean charge state . This latter criterion implies that the mean charge state depends on the electron density and temperature of the plasma. Also, the initial charge state of the heavy ion is crucial for calculating inside the plasma. Comparing our models and estimations with experimental data, a very good agreement is found. It is noticed that the energy loss in plasmas is higher than that in the same cold gas cases, confirming the well-known enhanced plasma stopping (EPS). In this case, EPS is only due to the increase in projectile effective charge Qeff, which is obtained as the ratio between the energy loss of each heavy ion and that of the proton in the same plasma conditions. The ratio between the effective charges in plasmas and in cold gases is higher than 1, but it is not as high as thought in the past. Finally, another significant issue is that the calculated effective charge in plasmas Qeff is greater than the mean charge state , which is due to the incorporation of the BK charge distribution. When estimations are performed without this distribution, they do not fit well with experimental data.

  5. Anomalous charge and negative-charge-transfer insulating state in cuprate chain compound KCuO2

    NASA Astrophysics Data System (ADS)

    Choudhury, D.; Rivero, P.; Meyers, D.; Liu, X.; Cao, Y.; Middey, S.; Whitaker, M. J.; Barraza-Lopez, S.; Freeland, J. W.; Greenblatt, M.; Chakhalian, J.

    2015-11-01

    Using a combination of x-ray absorption spectroscopy (XAS) experiments and first-principles calculations, we demonstrate that insulating KCuO2 contains Cu in an unusually high formal 3+ valence state, and the ligand-to-metal (O-to-Cu) charge-transfer energy is intriguingly negative (Δ ˜-1.5 eV) and has a dominant (˜60 % ) ligand-hole character in the ground state akin to the high Tc cuprate Zhang-Rice state. Unlike most other formal Cu3 + compounds, the Cu 2 p XAS spectra of KCuO2 exhibit pronounced 3 d8 (Cu3 +) multiplet structures, which account for ˜40 % of its ground state wave function. Ab initio calculations elucidate the origin of the band gap in KCuO2 as arising primarily from strong intracluster Cu 3 d -O 2 p hybridizations (tpd); the value of the band gap decreases with a reduced value of tpd. Further, unlike conventional negative-charge-transfer insulators, the band gap in KCuO2 persists even for vanishing values of Coulomb repulsion U , underscoring the importance of single-particle band-structure effects connected to the one-dimensional nature of the compound.

  6. Inline state of health estimation of lithium-ion batteries using state of charge calculation

    NASA Astrophysics Data System (ADS)

    Sepasi, Saeed; Ghorbani, Reza; Liaw, Bor Yann

    2015-12-01

    The determination of state-of-health (SOH) and state-of-charge (SOC) is challenging and remains as an active research area in academia and industry due to its importance for Li-ion battery applications. The estimation process poses more challenges after substantial battery aging. This paper presents an inline SOH and SOC estimation method for Li-ion battery packs, specifically for those based on LiFePO4 chemistry. This new hybridized SOC and SOH estimator can be used for battery packs. Inline estimated model parameters were used in a compounded SOC + SOH estimator consisting of the SOC calculation based on coulomb counting method as an expedient approach and an SOH observer using an extended Kalman filter (EKF) technique for calibrating the estimates from the coulomb counting method. The algorithm's low SOC and SOH estimation error, fast response time, and less-demanding computational requirement make it practical for on-board estimations. The simulation and experimental results, along with the test bed structure, are presented to validate the proposed methodology on a single cell and a 3S1P LiFePO4 battery pack.

  7. Mixed Exciton–Charge-Transfer States in Photosystem II: Stark Spectroscopy on Site-Directed Mutants

    PubMed Central

    Romero, Elisabet; Diner, Bruce A.; Nixon, Peter J.; Coleman, Wiliam J.; Dekker, Jan P.; van Grondelle, Rienk

    2012-01-01

    We investigated the electronic structure of the photosystem II reaction center (PSII RC) in relation to the light-induced charge separation process using Stark spectroscopy on a series of site-directed PSII RC mutants from the cyanobacterium Synechocystis sp. PCC 6803. The site-directed mutations modify the protein environment of the cofactors involved in charge separation (PD1, PD2, ChlD1, and PheD1). The results demonstrate that at least two different exciton states are mixed with charge-transfer (CT) states, yielding exciton states with CT character: (PD2δ+PD1δ−ChlD1)∗673nm and (ChlD1δ+PheD1δ−)∗681nm (where the subscript indicates the wavelength of the electronic transition). Moreover, the CT state PD2+PD1− acquires excited-state character due to its mixing with an exciton state, producing (PD2+PD1−)δ∗684nm. We conclude that the states that initiate charge separation are mixed exciton-CT states, and that the degree of mixing between exciton and CT states determines the efficiency of charge separation. In addition, the results reveal that the pigment-protein interactions fine-tune the energy of the exciton and CT states, and hence the mixing between these states. This mixing ultimately controls the selection and efficiency of a specific charge separation pathway, and highlights the capacity of the protein environment to control the functionality of the PSII RC complex. PMID:22853895

  8. Constructing diabatic states from adiabatic states: Extending generalized Mulliken-Hush to multiple charge centers with Boys localization

    NASA Astrophysics Data System (ADS)

    Subotnik, Joseph E.; Yeganeh, Sina; Cave, Robert J.; Ratner, Mark A.

    2008-12-01

    This article shows that, although Boys localization is usually applied to single-electron orbitals, the Boys method itself can be applied to many electron molecular states. For the two-state charge-transfer problem, we show analytically that Boys localization yields the same charge-localized diabatic states as those found by generalized Mulliken-Hush theory. We suggest that for future work in electron transfer, where systems have more than two charge centers, one may benefit by using a variant of Boys localization to construct diabatic potential energy surfaces and extract electronic coupling matrix elements. We discuss two chemical examples of Boys localization and propose a generalization of the Boys algorithm for creating diabatic states with localized spin density that should be useful for Dexter triplet-triplet energy transfer.

  9. Exceptionally Long-Lived Charge Separated State in Zeolitic Imidazolate Framework: Implication for Photocatalytic Applications.

    PubMed

    Pattengale, Brian; Yang, Sizhuo; Ludwig, John; Huang, Zhuangqun; Zhang, Xiaoyi; Huang, Jier

    2016-07-01

    Zeolitic imidazolate frameworks (ZIFs) have emerged as a novel class of porous metal-organic frameworks (MOFs) for catalysis application because of their exceptional thermal and chemical stability. Inspired by the broad absorption of ZIF-67 in UV-vis-near IR region, we explored its excited state and charge separation dynamics, properties essential for photocatalytic applications, using optical (OTA) and X-ray transient absorption (XTA) spectroscopy. OTA results show that an exceptionally long-lived excited state is formed after photoexcitation. This long-lived excited state was confirmed to be the charge-separated (CS) state with ligand-to-metal charge-transfer character using XTA. The surprisingly long-lived CS state, together with its intrinsic hybrid nature, all point to its potential application in heterogeneous photocatalysis and energy conversion. PMID:27322216

  10. Even and Odd Charge Coherent States: Higher-Order Nonclassical Properties and Generation Scheme

    NASA Astrophysics Data System (ADS)

    Duc, Truong Minh; Dinh, Dang Huu; Dat, Tran Quang

    2016-06-01

    We examine the higher-order nonclassical properties of the even and odd charge coherent states as well as proposing a scheme to generate these states whose modes can freely travel in open space. We show that the even and odd charge coherent states exhibit both higher-order antibunching and higher-order squeezing. While the two-mode higher-order antibunching occurs in any order and essentially depends on the charge number, the two-mode higher-order squeezing appears only in the even orders. We also prove that these states are genuinely entangled, and they can be generated by means of cross-Kerr media, beam splitters, phase shifts and threshold detectors. We find that the fidelity and the corresponding success probability to generate these states are dependent on the correlative parameters.

  11. Observation of slow charge redistribution preceding excited-state proton transfer

    SciTech Connect

    Spry, D. B.; Fayer, M. D.

    2007-11-28

    The photoacid 8-hydroxy-N,N,N{sup '},N{sup '},N{sup '},N{sup '}-hexamethylpyrene-1,3,6-trisulfonamide (HPTA) and related compounds are used to investigate the steps involved in excited-state deprotonation in polar solvents using pump-probe spectroscopy and time correlated single photon counting fluorescence spectroscopy. The dynamics show a clear two-step process leading to excited-state proton transfer. The first step after electronic excitation is charge redistribution occurring on a tens of picoseconds time scale followed by proton transfer on a nanosecond time scale. The three states observed in the experiments (initial excited state, charge redistributed state, and proton transfer state) are recognized by distinct features in the time dependence of the pump-probe spectrum and fluorescence spectra. In the charge redistributed state, charge density has transferred from the hydroxyl oxygen to the pyrene ring, but the OH sigma bond is still intact. The experiments indicate that the charge redistribution step is controlled by a specific hydrogen bond donation from HPTA to the accepting base molecule. The second step is the full deprotonation of the photoacid. The full deprotonation is clearly marked by the growth of stimulated emission spectral band in the pump-probe spectrum that is identical to the fluorescence spectrum of the anion.

  12. Topological charges in 2D N =(2 ,2 ) theories and massive BPS states

    NASA Astrophysics Data System (ADS)

    Park, Daniel S.

    2015-07-01

    We study how charges of global symmetries that are manifest in the ultraviolet definition of a theory are realized as topological charges in its infrared effective theory for two-dimensional theories with N =(2 ,2 ) supersymmetry. We focus on the charges that the states living on S1 carry. The central charge—or Bogomol'nyi-Prasad-Sommerfield (BPS) masses—of the supersymmetry algebra play a crucial role in making this correspondence precise. We study two examples: U (1 ) gauge theories with chiral matter and world-volume theories of "dynamical surface operators" of four-dimensional N =2 gauge theories. In the former example, we show that the flavor charges of the theory are realized as topological winding numbers in the effective theory on the Coulomb branch. In the latter, we show that there is a one-to-one correspondence between topological charges of the effective theory of the dynamical surface operator and the electric, magnetic, and flavor charges of the four-dimensional gauge theory. We also examine the topologically charged massive BPS states on S1 and discover that the massive BPS spectrum is sensitive to the radius of the circle in the simplest theory—the free theory of a periodic twisted chiral field. We clarify this behavior by showing that the massive BPS spectrum on S1, unlike the BPS ground states, cannot be identified as elements of a cohomology.

  13. Tunable cw UV laser with <35 kHz absolute frequency instability for precision spectroscopy of Sr Rydberg states.

    PubMed

    Bridge, Elizabeth M; Keegan, Niamh C; Bounds, Alistair D; Boddy, Danielle; Sadler, Daniel P; Jones, Matthew P A

    2016-02-01

    We present a solid-state laser system that generates over 200 mW of continuous-wave, narrowband light, tunable from 316.3 nm - 317.7 nm and 318.0 nm - 319.3 nm. The laser is based on commercially available fiber amplifiers and optical frequency doubling technology, along with sum frequency generation in a periodically poled stoichiometric lithium tantalate crystal. The laser frequency is stabilized to an atomic-referenced high finesse optical transfer cavity. Using a GPS-referenced optical frequency comb we measure a long term frequency instability of < 35 kHz for timescales between 10(-3) s and 10(3) s. As an application we perform spectroscopy of Sr Rydberg states from n = 37 - 81, demonstrating mode-hop-free scans of 24 GHz. In a cold atomic sample we measure Doppler-limited linewidths of 350 kHz. PMID:26906804

  14. and interactions and the charged charmonium-like state Z(4430)

    NASA Astrophysics Data System (ADS)

    Jun, He; Pei-Liang, Lü

    2016-04-01

    The and interactions are studied in a one-boson-exchange model. Isovector bound state solutions with spin parity J P = 1+ are found from the interaction, which may be related to the observed charged charmonium-like state Z(4430). There is no bound state solution found from the interaction. Supported by Major State Basic Research Development Program in China (2014CB845405), National Natural Science Foundation of China (11275235)

  15. Charge state evolution of 2 MeV/u sulfur ion passing through thin carbon foil

    NASA Astrophysics Data System (ADS)

    Imai, M.; Sataka, M.; Kawatsura, K.; Takahiro, K.; Komaki, K.; Shibata, H.; Sugai, H.; Nishio, K.

    2007-03-01

    Charge state distribution and its evolution for 2.0 MeV/u sulfur ions after passing through 0.9, 1.1, 1.5, 2.0, 3.0, 4.7, 6.9 and 10 μg/cm2 carbon foils have been extensively studied following our previous paper [M. Imai, M. Sataka, K. Kawatsura, K. Takahiro, K. Komaki, H. Shibata, H. Sugai, K. Nishio, Nucl. Instr. and Meth. B 230 (2005) 63] to derive data for all the initial charge states between 6+ and 14+. Measured charge state distributions, their mean charge states and distribution widths do not flat off to establish equilibrium within the measured target thickness, and an overshooting feature of the distribution width for S6+ projectile is observed around 1 μg/cm2 in the target thickness. Two kinds of calculations, one based on rate equations accounting only for single charge transfer and the other applying ETACHA code, show good agreements with the experimental evolutions of mean charge and distribution width.

  16. Development of reference states for use in absolute free energy calculations of atomic clusters with application to 55-atom Lennard-Jones clusters in the solid and liquid states

    NASA Astrophysics Data System (ADS)

    Amon, L. M.; Reinhardt, W. P.

    2000-09-01

    In this paper four reference states allowing computation of the absolute internal free energies of solid and liquid clusters are introduced and implemented. Three of these are introduced for the first time. Two of these references are useful for highly fluctional liquidlike clusters while the other two are appropriate for more rigid solidlike clusters. These reference states are combined with a finite time variational method to obtain upper and lower bounds to the absolute free energies of clusters of Lennard-Jones (LJ) atoms, LJ4 and LJ55, allowing the efficiency of each of the four reference states to be elucidated. The optimal references are then applied to obtain upper and lower bounds to the internal free energies (the absolute free energy in the cluster center of mass frame) of LJ55 over a series of fixed temperatures including the solid-liquid coexistence regime. The reversible scaling method, recently introduced by de Koning, Antonelli, and Yip, is then used to extend the results over a continuous range of temperatures. Estimation of the rotational free energy allows comparisons to free energies of LJ55 in the nonrotating center of mass frame as estimated by Doye and Wales.

  17. Controllable Quantum State Transfer Between a Josephson Charge Qubit and an Electronic Spin Ensemble

    NASA Astrophysics Data System (ADS)

    Yan, Run-Ying; Wang, Hong-Ling; Feng, Zhi-Bo

    2016-01-01

    We propose a theoretical scheme to implement controllable quantum state transfer between a superconducting charge qubit and an electronic spin ensemble of nitrogen-vacancy centers. By an electro-mechanical resonator acting as a quantum data bus, an effective interaction between the charge qubit and the spin ensemble can be achieved in the dispersive regime, by which state transfers are switchable due to the adjustable electrical coupling. With the accessible experimental parameters, we further numerically analyze the feasibility and robustness. The present scheme could provide a potential approach for transferring quantum states controllably with the hybrid system.

  18. Spectroscopic charge pumping investigation of the amphoteric nature of Si/SiO2 interface states

    NASA Astrophysics Data System (ADS)

    Ryan, J. T.; Yu, L. C.; Han, J. H.; Kopanski, J. J.; Cheung, K. P.; Zhang, F.; Wang, C.; Campbell, J. P.; Suehle, J. S.

    2011-06-01

    The amphoteric nature of Si/SiO2 interface states in submicron sized metal-oxide-silicon-field-effect-transistors is observed using an enhanced spectroscopic charge pumping method. The method's simplicity and high sensitivity makes it a powerful tool for interrogating the true nature of electrically measured interface states in samples which exhibit extremely low defect densities. The spectroscopic results obtained clearly illustrate a signature "double peak" density of states consistent with amphoteric Pb center data obtained from electron spin resonance measurements. Since the method is a hybrid of the commonly used charge pumping methodology, it should find widespread use in electronic device characterization.

  19. Target life time of laser ion source for low charge state ion production

    SciTech Connect

    Kanesue,T.; Tamura, J.; Okamura, M.

    2008-06-23

    Laser ion source (LIS) produces ions by irradiating pulsed high power laser shots onto the solid state target. For the low charge state ion production, laser spot diameter on the target can be over several millimeters using a high power laser such as Nd:YAG laser. In this case, a damage to the target surface is small while there is a visible crater in case of the best focused laser shot for high charge state ion production (laser spot diameter can be several tens of micrometers). So the need of target displacement after each laser shot to use fresh surface to stabilize plasma is not required for low charge state ion production. We tested target lifetime using Nd:YAG laser with 5 Hz repetition rate. Also target temperature and vacuum condition were recorded during experiment. The feasibility of a long time operation was verified.

  20. Characterization of Final State Interaction Strength in Plastic Scintillator by Muon-Neutrino Charged Current Charged Pion Production

    SciTech Connect

    Eberly, Brandon M.

    2014-01-01

    Precise knowledge of neutrino-nucleus interactions is increasingly important as neutrino oscillation measurements transition into the systematics-limited era. In addition to modifying the initial interaction, the nuclear medium can scatter and absorb the interaction by-products through final state interactions, changing the types and kinematic distributions of particles seen by the detector. Recent neutrino pion production data from MiniBooNE is inconsistent with the final state interaction strength predicted by models and theoretical calculations, and some models fit best to the MiniBooNE data only after removing final state interactions entirely. This thesis presents a measurement of dσ/dTπ and dσ/dθπ for muon-neutrino charged current charged pion production in the MINER A scintillator tracker. MINER A is a neutrino-nucleus scattering experiment installed in the few-GeV NuMI beam line at Fermilab. The analysis is limited to neutrino energies between 1.5-10 GeV. Dependence on invariant hadronic mass W is studied through two versions of the analysis that impose the limits W < 1.4 GeV and W < 1.8 GeV. The lower limit on W increases compatibility with the MiniBooNE pion data. The shapes of the differential cross sections, which depend strongly on the nature of final state interactions, are compared to Monte Carlo and theoretical predictions. It is shown that the measurements presented in this thesis favor models that contain final state interactions. Additionally, a variety of neutrino-nucleus interaction models are shown to successfully reproduce the thesis measurements, while simultaneously failing to describe the shape of the MiniBooNE data.

  1. Space-charge-limited solid-state triode

    NASA Technical Reports Server (NTRS)

    Shumka, A. (Inventor)

    1975-01-01

    A solid-state triode is provided from a wafer of nearinstrinsic semiconductor material sliced into filaments of rectangular cross section. Before slicing, emitter and collector regions are formed on the narrow sides of the filaments, and after slicing gate regions are formed in arrow strips extending longitudinally along the midsections of the wide sides of the filaments. Contacts are then formed on the emitter, collector and gate regions of each filament individually for a single filament device, or in parallel for an array of filament devices to increase load current.

  2. Performance characteristics of a battery charger and state-of-charge indicator

    NASA Technical Reports Server (NTRS)

    Edwards, D.; Klein, J.

    1984-01-01

    A battery charge/state of charge indicator (BC/SCI) system for electric vehicle use was developed. The original and subsequent objectives for the BC/SCI and the rationale for those objectives are described. The requirements generated from the objectives are listed and a description of the BC/SCI is provided. The power section problem, the tests, and the test results are discussed.

  3. Under non-denaturing solvent conditions, the mean charge state of a multiply charged protein ion formed by electrospray is linearly correlated with the macromolecular surface

    NASA Astrophysics Data System (ADS)

    Hautreux, Mélanie; Hue, Nathalie; Du Fou de Kerdaniel, Alexis; Zahir, Abdelattif; Malec, Valérie; Laprévote, Olivier

    2004-02-01

    The charge states of protein ion species generated by electrospray under non-denaturing solvent conditions are strongly dependent on the occurrence of gas phase proton transfer reactions. Thus, by adding basic compounds to an array of model protein solutions, the charged states of multiply charged ions decrease with increasing the gas phase basicity of these additives. The role played by the basic (lysine and arginine) and acidic (aspartic and glutamic acids) amino acid side chains toward the proton exchange processes has been examined by using a series of basic compounds added to the protein solutions. In the present study, no relationship could be established between the presence at the protein surface of basic or acidic residues and the measured charged states. Actually, independently on their amino acid composition, the protein ions show a linear correlation between their mean charge state and their surface considered as a spherical area.

  4. Defect charge states in Si doped hexagonal boron-nitride monolayer

    NASA Astrophysics Data System (ADS)

    Mapasha, R. E.; Molepo, M. P.; Andrew, R. C.; Chetty, N.

    2016-02-01

    We perform ab initio density functional theory calculations to investigate the energetics, electronic and magnetic properties of isolated stoichiometric and non-stoichiometric substitutional Si complexes in a hexagonal boron-nitride monolayer. The Si impurity atoms substituting the boron atom sites SiB giving non-stoichiometric complexes are found to be the most energetically favourable, and are half-metallic and order ferromagnetically in the neutral charge state. We find that the magnetic moments and magnetization energies increase monotonically when Si defects form a cluster. Partial density of states and standard Mulliken population analysis indicate that the half-metallic character and magnetic moments mainly arise from the Si 3p impurity states. The stoichiometric Si complexes are energetically unfavorable and non-magnetic. When charging the energetically favourable non-stoichiometric Si complexes, we find that the formation energies strongly depend on the impurity charge states and Fermi level position. We also find that the magnetic moments and orderings are tunable by charge state modulation q  =  -2, -1, 0, +1, +2. The induced half-metallic character is lost (retained) when charging isolated (clustered) Si defect(s). This underlines the potential of a Si doped hexagonal boron-nitride monolayer for novel spin-based applications.

  5. Charge state evolution in the solar wind. III. Model comparison with observations

    SciTech Connect

    Landi, E.; Oran, R.; Lepri, S. T.; Zurbuchen, T. H.; Fisk, L. A.; Van der Holst, B.

    2014-08-01

    We test three theoretical models of the fast solar wind with a set of remote sensing observations and in-situ measurements taken during the minimum of solar cycle 23. First, the model electron density and temperature are compared to SOHO/SUMER spectroscopic measurements. Second, the model electron density, temperature, and wind speed are used to predict the charge state evolution of the wind plasma from the source regions to the freeze-in point. Frozen-in charge states are compared with Ulysses/SWICS measurements at 1 AU, while charge states close to the Sun are combined with the CHIANTI spectral code to calculate the intensities of selected spectral lines, to be compared with SOHO/SUMER observations in the north polar coronal hole. We find that none of the theoretical models are able to completely reproduce all observations; namely, all of them underestimate the charge state distribution of the solar wind everywhere, although the levels of disagreement vary from model to model. We discuss possible causes of the disagreement, namely, uncertainties in the calculation of the charge state evolution and of line intensities, in the atomic data, and in the assumptions on the wind plasma conditions. Last, we discuss the scenario where the wind is accelerated from a region located in the solar corona rather than in the chromosphere as assumed in the three theoretical models, and find that a wind originating from the corona is in much closer agreement with observations.

  6. Modulation of nitrogen vacancy charge state and fluorescence in nanodiamonds using electrochemical potential

    NASA Astrophysics Data System (ADS)

    Karaveli, Sinan; Gaathon, Ophir; Wolcott, Abraham; Sakakibara, Reyu; Shemesh, Or A.; Peterka, Darcy S.; Boyden, Edward S.; Owen, Jonathan S.; Yuste, Rafael; Englund, Dirk

    2016-04-01

    The negatively charged nitrogen vacancy (NV-) center in diamond has attracted strong interest for a wide range of sensing and quantum information processing applications. To this end, recent work has focused on controlling the NV charge state, whose stability strongly depends on its electrostatic environment. Here, we demonstrate that the charge state and fluorescence dynamics of single NV centers in nanodiamonds with different surface terminations can be controlled by an externally applied potential difference in an electrochemical cell. The voltage dependence of the NV charge state can be used to stabilize the NV- state for spin-based sensing protocols and provides a method of charge state-dependent fluorescence sensing of electrochemical potentials. We detect clear NV fluorescence modulation for voltage changes down to 100 mV, with a single NV and down to 20 mV with multiple NV centers in a wide-field imaging mode. These results suggest that NV centers in nanodiamonds could enable parallel optical detection of biologically relevant electrochemical potentials.

  7. Probing excited state charge transfer dynamics in a heteroleptic ruthenium complex.

    PubMed

    Ghosh, Rajib; Palit, Dipak K

    2014-01-01

    Dynamics of metal to ligand charge transfer in the excited states of ruthenium polypyridyl complexes, which have shown promise as materials for artificial solar energy harvesting, has been of immense interest recently. Mixed ligand complexes are especially important for broader absorption in the visible region. Dynamics of ultrafast vibrational energy relaxation and inter-ligand charge transfer processes in the excited states of a heteroleptic ruthenium complex, [Ru(bpy)2(pap)](ClO4)2 (where bpy is 2,2'-bipyridine and pap is 2-(phenylazo)pyridine) have been investigated using femtosecond to nanosecond time-resolved transient absorption spectroscopic techniques. A good agreement between the TA spectrum of the lowest excited (3)MLCT state of [Ru(bpy)2(pap)](ClO4)2 complex and the anion radical spectrum of the pap ligand, which has been generated using the pulse radiolysis technique, confirmed the charge localization at the pap ligand. While the lifetime of the inter-ligand charge transfer from the bpy to the pap ligand in the (3)MLCT state is about 2.5 ps, vibrational cooling of the pap-localized(3)MLCT state occurs over a much longer time scale with a lifetime of about 35 ps. Ultrafast charge localization dynamics observed here may have important consequences in artificial solar energy harvesting systems, which employ heteroleptic ruthenium complexes. PMID:24247908

  8. A vacuum spark ion source: High charge state metal ion beams

    NASA Astrophysics Data System (ADS)

    Yushkov, G. Yu.; Nikolaev, A. G.; Oks, E. M.; Frolova, V. P.

    2016-02-01

    High ion charge state is often important in ion beam physics, among other reasons for the very practical purpose that it leads to proportionately higher ion beam energy for fixed accelerating voltage. The ion charge state of metal ion beams can be increased by replacing a vacuum arc ion source by a vacuum spark ion source. Since the voltage between anode and cathode remains high in a spark discharge compared to the vacuum arc, higher metal ion charge states are generated which can then be extracted as an ion beam. The use of a spark of pulse duration less than 10 μs and with current up to 10 kA allows the production of ion beams with current of several amperes at a pulse repetition rate of up to 5 pps. We have demonstrated the formation of high charge state heavy ions (bismuth) of up to 15 + and a mean ion charge state of more than 10 +. The physics and techniques of our vacuum spark ion source are described.

  9. A vacuum spark ion source: High charge state metal ion beams.

    PubMed

    Yushkov, G Yu; Nikolaev, A G; Oks, E M; Frolova, V P

    2016-02-01

    High ion charge state is often important in ion beam physics, among other reasons for the very practical purpose that it leads to proportionately higher ion beam energy for fixed accelerating voltage. The ion charge state of metal ion beams can be increased by replacing a vacuum arc ion source by a vacuum spark ion source. Since the voltage between anode and cathode remains high in a spark discharge compared to the vacuum arc, higher metal ion charge states are generated which can then be extracted as an ion beam. The use of a spark of pulse duration less than 10 μs and with current up to 10 kA allows the production of ion beams with current of several amperes at a pulse repetition rate of up to 5 pps. We have demonstrated the formation of high charge state heavy ions (bismuth) of up to 15 + and a mean ion charge state of more than 10 +. The physics and techniques of our vacuum spark ion source are described. PMID:26931966

  10. Modulation of nitrogen vacancy charge state and fluorescence in nanodiamonds using electrochemical potential

    PubMed Central

    Karaveli, Sinan; Gaathon, Ophir; Wolcott, Abraham; Sakakibara, Reyu; Shemesh, Or A.; Peterka, Darcy S.; Boyden, Edward S.; Owen, Jonathan S.; Yuste, Rafael; Englund, Dirk

    2016-01-01

    The negatively charged nitrogen vacancy (NV−) center in diamond has attracted strong interest for a wide range of sensing and quantum information processing applications. To this end, recent work has focused on controlling the NV charge state, whose stability strongly depends on its electrostatic environment. Here, we demonstrate that the charge state and fluorescence dynamics of single NV centers in nanodiamonds with different surface terminations can be controlled by an externally applied potential difference in an electrochemical cell. The voltage dependence of the NV charge state can be used to stabilize the NV− state for spin-based sensing protocols and provides a method of charge state-dependent fluorescence sensing of electrochemical potentials. We detect clear NV fluorescence modulation for voltage changes down to 100 mV, with a single NV and down to 20 mV with multiple NV centers in a wide-field imaging mode. These results suggest that NV centers in nanodiamonds could enable parallel optical detection of biologically relevant electrochemical potentials. PMID:27035935

  11. Charge State Evolution in the Solar Wind. III. Model Comparison with Observations

    NASA Astrophysics Data System (ADS)

    Landi, E.; Oran, R.; Lepri, S. T.; Zurbuchen, T. H.; Fisk, L. A.; van der Holst, B.

    2014-08-01

    We test three theoretical models of the fast solar wind with a set of remote sensing observations and in-situ measurements taken during the minimum of solar cycle 23. First, the model electron density and temperature are compared to SOHO/SUMER spectroscopic measurements. Second, the model electron density, temperature, and wind speed are used to predict the charge state evolution of the wind plasma from the source regions to the freeze-in point. Frozen-in charge states are compared with Ulysses/SWICS measurements at 1 AU, while charge states close to the Sun are combined with the CHIANTI spectral code to calculate the intensities of selected spectral lines, to be compared with SOHO/SUMER observations in the north polar coronal hole. We find that none of the theoretical models are able to completely reproduce all observations; namely, all of them underestimate the charge state distribution of the solar wind everywhere, although the levels of disagreement vary from model to model. We discuss possible causes of the disagreement, namely, uncertainties in the calculation of the charge state evolution and of line intensities, in the atomic data, and in the assumptions on the wind plasma conditions. Last, we discuss the scenario where the wind is accelerated from a region located in the solar corona rather than in the chromosphere as assumed in the three theoretical models, and find that a wind originating from the corona is in much closer agreement with observations.

  12. Effects of Solar Magnetic Activity on the Charge States of Minor Ions of Solar Wind

    NASA Astrophysics Data System (ADS)

    Wang, Xuyu

    We present an investigation of the effects of solar magnetic activity on the charge states of minor ions (Fe, Si, Mg, Ne, O, C) in the solar wind using ACE solar wind data, the Current Sheet Source Surface (CSSS) model of the corona and SoHO/MDI data during the 23rd solar cycle. We found that the mean charge states indicate a clear trend to increase with the solar activity when the solar wind speed is above 550 km/s. Below this speed, no significant solar activity dependence is found. When displayed as a function of solar wind speed, iron is different from other elements in that it displays lower charge states in slow wind than in fast wind. The percentages of the high charge states for species with higher m/q (Fe) increase with the solar wind speed, while for the species with lower m/q (Si,Mg, O, C), the percentages of the high charge states decrease with the solar wind speed.

  13. Eosinophil count - absolute

    MedlinePlus

    Eosinophils; Absolute eosinophil count ... the white blood cell count to give the absolute eosinophil count. ... than 500 cells per microliter (cells/mcL). Normal value ranges may vary slightly among different laboratories. Talk ...

  14. Decay of Bloch oscillations in the charge-density-wave ordered phase of an all electronic charge density wave state

    NASA Astrophysics Data System (ADS)

    Matveev, Oleg; Shvaika, Andrij; Devereaux, Thomas; Freericks, James

    The charge-density-wave phase of the Falicov-Kimball model displays a number of anomalous behavior including the appearance of subgap density of states as the temperature increases. These subgap states should have a significant impact on transport properties, particularly the nonlinear response of the system to a large dc electric field. Using the Kadanoff-Baym-Keldysh formalism, we employ nonequilibrium dynamical mean-field theory to exactly solve for this nonlinear response. We examine both the current and the order parameter of the conduction electrons as the ordered system is driven by a dc electric field. Institute for Condensed Matter Physics of the National Academy of Sciences of Ukraine, Lviv, Ukraine.

  15. Excited state and charge dynamics of hybrid organic/inorganic heterojunctions. I. Theory

    NASA Astrophysics Data System (ADS)

    Renshaw, C. Kyle; Forrest, Stephen R.

    2014-07-01

    The different cohesive forces that bond organic (i.e. excitonic) and inorganic semiconductors lead to widely disparate dielectric constants, charge mobilities, and other fundamental optoelectronic properties that make junctions between these materials interesting for numerous practical applications. Yet, there are no detailed theories addressing charge and energy transport across interfaces between these hybrid systems. Here, we develop a comprehensive physical model describing charge transport and photocurrent generation based on first-principles charge and excited state dynamics at the organic/inorganic heterojunction. We consider interfaces that are trap-free, as well as those with an exponential distribution of trap states. We find that the hybrid charge-transfer state resulting from photon absorption near the junction that subsequently migrates to the heterointerface is often unstable at room temperature, leading to its rapid dissociation into free charges that are collected at the device contacts. In the companion Paper II [A. Panda et al., Phys. Rev. B 90, 045303 (2014), 10.1103/PhysRevB.90.045303], we apply our theories to understanding the optical and electronic properties of archetype organic/inorganic heterojunction diodes. Our analysis provides insights for developing high performance optoelectronic devices whose properties are otherwise inaccessible to either conventional excitonic or inorganic semiconductor junctions.

  16. Local charge states in hexagonal boron nitride with Stone-Wales defects.

    PubMed

    Wang, Rui; Yang, Jiali; Wu, Xiaozhi; Wang, Shaofeng

    2016-04-21

    A Stone-Wales (SW) defect is the simplest topological defect in graphene-like materials and can be potentially employed to design electronic devices . In this paper, we have systematically investigated the formation, structural, and electronic properties of the neutral and charged SW defects in hexagonal boron nitride (BN) using first-principles calculations. The transition states and energy barrier for the formation of SW defects demonstrate that the defected BN is stable. Our calculations show that there are two in-gap defect levels, which originate from the asymmetrical pentagon-heptagon pairs. The local defect configurations and electronic properties are sensitive to their charge states induced by the defect levels. The electronic band structures show that the negative and positive charged defects are mainly determined by shifting the conduction band minimum (CBM) and valence band maximum (VBM) respectively, and the SW-defected BN can realize -1 and +1 spin-polarized charge states. The effects of carbon (C) substitution on neutral and charged SW-defected BN have also been studied. Our results indicate that the C substitution of B in BN is in favour of the formation of SW defects. Structural and electronic calculations show rich charge-dependent properties of C substitutions in SW-defected BN, thus our theoretical study is important for various applications in the design of BN nanostructure-based devices. PMID:27030259

  17. Local charge states in hexagonal boron nitride with Stone-Wales defects

    NASA Astrophysics Data System (ADS)

    Wang, Rui; Yang, Jiali; Wu, Xiaozhi; Wang, Shaofeng

    2016-04-01

    A Stone-Wales (SW) defect is the simplest topological defect in graphene-like materials and can be potentially employed to design electronic devices . In this paper, we have systematically investigated the formation, structural, and electronic properties of the neutral and charged SW defects in hexagonal boron nitride (BN) using first-principles calculations. The transition states and energy barrier for the formation of SW defects demonstrate that the defected BN is stable. Our calculations show that there are two in-gap defect levels, which originate from the asymmetrical pentagon-heptagon pairs. The local defect configurations and electronic properties are sensitive to their charge states induced by the defect levels. The electronic band structures show that the negative and positive charged defects are mainly determined by shifting the conduction band minimum (CBM) and valence band maximum (VBM) respectively, and the SW-defected BN can realize -1 and +1 spin-polarized charge states. The effects of carbon (C) substitution on neutral and charged SW-defected BN have also been studied. Our results indicate that the C substitution of B in BN is in favour of the formation of SW defects. Structural and electronic calculations show rich charge-dependent properties of C substitutions in SW-defected BN, thus our theoretical study is important for various applications in the design of BN nanostructure-based devices.

  18. Cathode material comparison of thermal runaway behavior of Li-ion cells at different state of charges including over charge

    NASA Astrophysics Data System (ADS)

    Mendoza-Hernandez, Omar Samuel; Ishikawa, Hiroaki; Nishikawa, Yuuki; Maruyama, Yuki; Umeda, Minoru

    2015-04-01

    The analysis of Li-ion secondary cells under outstanding conditions, as overcharge and high temperatures, is important to determine thermal abuse characteristics of electroactive materials and precise risk assessments on Li-ion cells. In this work, the thermal runaway behavior of LiCoO2 and LiMn2O4 cathode materials were compared at different state of charges (SOCs), including overcharge, by carrying out accelerating rate calorimetry (ARC) measurements using 18650 Li-ion cells. Onset temperatures of self-heating reactions and thermal runaway behavior were identified, and by using these onset points thermal mapping plots were made. We were able to identify non-self-heating, self-heating and thermal runaway regions as a function of state of charge and temperature. The cell using LiMn2O4 cathode material was found to be more thermally stable than the cell using LiCoO2. In parallel with the ARC measurements, the electrochemical behavior of the cells was monitored by measuring the OCV and internal resistance of the cells. The electrochemical behavior of the cells showed a slightly dependency on SOC.

  19. Calculation of charge-state ratios for satellite Tor I

    NASA Technical Reports Server (NTRS)

    Summers, D.; Siscoe, G. L.

    1985-01-01

    The diffusion of ions in a satellite plasma torus is presently modeled in terms of a one-dimensional random walk in which the particle source is at 0, the particle sink is at an N value that is an integer greater than 2, and the scale size of the diffusion cell is unity. The probability distribution function of the number of steps to exit for an ion is obtained and used in a model which incorporates ionization by electron impact to derive steady state expressions for the ratio of doubly to singly ionized ions, as well as the total number of ions in the torus. The results thus obtained are applied to the torus of the Jovian satellite Io, in order to predict mean residence times for sulfur and oxygen ions.

  20. Nature and location of excited charge-transfer states in the porphine-magnesium porphine dimer

    NASA Astrophysics Data System (ADS)

    Petke, J. D.; Maggiora, G. M.

    1983-05-01

    The ground and excited states of a cofacial porphine-magnesium porphine dimer with a ring separation of 5.35 Å are investigated by ab initio configuration interaction calculations, using a floating gaussian basis. A pair of charge-transfer states are found ≈23000 cm -1 above the ground state, but are lowered by ≈7400 cm -1 upon coordination of the Mg atom with chloride ion.

  1. Excited-state charging energies in quantum dots investigated by terahertz photocurrent spectroscopy

    NASA Astrophysics Data System (ADS)

    Zhang, Y.; Shibata, K.; Nagai, N.; Ndebeka-Bandou, C.; Bastard, G.; Hirakawa, K.

    2016-06-01

    We have investigated the excited-state (ES) charging energies in quantum dots (QDs) by measuring a terahertz (THz)-induced photocurrent in a single-electron transistor (SET) geometry that contains a single InAs QD between metal nanogap electrodes. A photocurrent is produced in the QD SETs through THz intersublevel transitions and the subsequent resonant tunneling. We have found that the photocurrent exhibits stepwise change even within one Coulomb blockaded region as the electrochemical potential in the QD is swept by the gate voltage. From the threshold for the photocurrent generation, we have determined the charging energies for adding an electron in the photoexcited state in the QD. Furthermore, the charging energies for the ESs with different electron configurations are clearly resolved. The present THz photocurrent measurements are essentially dynamical experiments and allow us to analyze electronic properties in off-equilibrium states in the QD.

  2. Charge state dynamics of the nitrogen vacancy center in diamond under 1064-nm laser excitation

    NASA Astrophysics Data System (ADS)

    Ji, Peng; Dutt, M. V. Gurudev

    2016-07-01

    The photophysics and charge state dynamics of the nitrogen vacancy (NV) center in diamond has been extensively investigated, but is still not fully understood. In contrast to previous work, we find that NV0 converts to NV- under excitation with low power near-infrared (1064-nm) light, resulting in increased photoluminescence from the NV- state. We used a combination of spectral and time-resolved photoluminescence experiments and rate-equation modeling to conclude that NV0 converts to NV- via absorption of 1064-nm photons from the valence band of diamond. We report fast quenching and recovery of the photoluminescence from both charge states of the NV center under low power 1064-nm laser excitation, which has not been previously observed. We also find, using optically detected magnetic resonance experiments, that the charge transfer process mediated by the 1064-nm laser is spin dependent.

  3. Ionic charge state distribution of helium, carbon, oxygen, and iron in an energetic storm particle enhancement

    NASA Technical Reports Server (NTRS)

    Hovestadt, D.; Klecker, B.; Hoefner, H.; Scholer, M.; Gloeckler, G.; Ipavich, F. M.

    1982-01-01

    An analysis is presented of the ionic charge state distribution of He, C, O and Fe in the energetic storm particle event of September 28-29, 1978. Data were obtained with the ULEZEQ electrostatic analyzer-proportional counter on board the ISEE 3 spacecraft. The He(+)/He(++) ratio between 0.4 and 1 MeV/n is shown to be significantly lower during the energetic storm particle event than during the preceding period of solar flare particle enhancement, with a temporal evolution similar to that of the Fe/He ratio as reported by Klecker et al. (1981). Increases in the mean charge state for oxygen by about 3% and for iron by about 16% are also noted. The temporal variations in charge states are accounted for in terms of first-order Fermi acceleration of the pre-existing solar flare particles by a propagating interplanetary shock wave.

  4. Charge-state dependence of kinetic electron emission induced by slow ions in metals

    SciTech Connect

    Juaristi, J.I.; Dubus, A.; Roesler, M.

    2003-07-01

    A calculation is performed in order to analyze the charge-state dependence of the kinetic electron emission induced by slow ions in metals. All stages of the emission process are included: the excitation of the electrons, the neutralization of the projectile during its passage through the solid, and the transport of the excited electrons from where they are created to the surface. It is shown that the number of excited electrons depends strongly on the ion charge state. Nevertheless, due to the fast neutralization of the ions within the escape depth of the excited electrons, no significant initial charge-state dependence is expected in the kinetic electron yield. This result is consistent with available experimental data.

  5. Charge Transfer and Triplet States in High Efficiency OPV Materials and Devices

    NASA Astrophysics Data System (ADS)

    Dyakonov, Vladimir

    2013-03-01

    The advantage of using polymers and molecules in electronic devices, such as light-emitting diodes (LED), field-effect transistors (FET) and, more recently, solar cells (SC) is justified by the unique combination of high device performance and processing of the semiconductors used. Power conversion efficiency of nanostructured polymer SC is in the range of 10% on lab scale, making them ready for up-scaling. Efficient charge carrier generation and recombination in SC are strongly related to dissociation of the primary singlet excitons. The dissociation (or charge transfer) process should be very efficient in photovoltaics. The mechanisms governing charge carrier generation, recombination and transport in SC based on the so-called bulk-heterojunctions, i.e. blends of two or more semiconductors with different electron affinities, appear to be very complex, as they imply the presence of the intermediate excited states, neutral and charged ones. Charge transfer states, or polaron pairs, are the intermediate states between free electrons/holes and strongly bound excitons. Interestingly, the mostly efficient OLEDs to date are based on the so-called triplet emitters, which utilize the triplet-triplet annihilation process. In SC, recent investigations indicated that on illumination of the device active layer, not only mobile charges but also triplet states were formed. With respect to triplets, it is unclear how these excited states are generated, via inter-system crossing or via back transfer of the electron from acceptor to donor. Triplet formation may be considered as charge carrier loss channel; however, the fusion of two triplets may lead to a formation of singlet excitons instead. In such case, a generation of charges by utilizing of the so far unused photons will be possible. The fundamental understanding of the processes involving the charge transfer and triplet states and their relation to nanoscale morphology and/or energetics of blends is essential for the

  6. Ion charge state distributions of pulsed vacuum arc plasmas in strong magnetic fields

    SciTech Connect

    Anders, A.; Yushkov, G.; Oks, E.; Nikolaev, A.; Brown, I.

    1998-02-01

    Vacuum arc plasmas with discharge currents of 300 A and duration 250 {mu}s have been produced in strong magnetic fields up to 4 T. Ion charge state distributions have been measured for C, Al, Ag, Ta, Pt, Ho, and Er with a time-of-flight charge-mass spectrometer. Our previous measurements have been confirmed which show that ion charge states can be considerably enhanced when increasing the magnetic field up to about 1 T. The new measurements address the question of whether or not the additional increase continues at even higher magnetic field strength. It has been found that the increase becomes insignificant for field strengths greater than 1 T. Ion charge state distributions are almost constant for magnetic field strengths between 2 and 4 T. The results are explained by comparing the free expansion length with the freezing length. The most significant changes of charge state distributions are observed when these lengths are similar. {copyright} {ital 1998 American Institute of Physics.}

  7. Charge-ordering cascade with spin-orbit Mott dimer states in metallic iridium ditelluride.

    PubMed

    Ko, K-T; Lee, H-H; Kim, D-H; Yang, J-J; Cheong, S-W; Eom, M J; Kim, J S; Gammag, R; Kim, K-S; Kim, H-S; Kim, T-H; Yeom, H-W; Koo, T-Y; Kim, H-D; Park, J-H

    2015-01-01

    Spin-orbit coupling results in technologically-crucial phenomena underlying magnetic devices like magnetic memories and energy-efficient motors. In heavy element materials, the strength of spin-orbit coupling becomes large to affect the overall electronic nature and induces novel states such as topological insulators and spin-orbit-integrated Mott states. Here we report an unprecedented charge-ordering cascade in IrTe2 without the loss of metallicity, which involves localized spin-orbit Mott states with diamagnetic Ir(4+)-Ir(4+) dimers. The cascade in cooling, uncompensated in heating, consists of first order-type consecutive transitions from a pure Ir(3+) phase to Ir(3+)-Ir(4+) charge-ordered phases, which originate from Ir 5d to Te 5p charge transfer involving anionic polymeric bond breaking. Considering that the system exhibits superconductivity with suppression of the charge order by doping, analogously to cuprates, these results provide a new electronic paradigm of localized charge-ordered states interacting with itinerant electrons through large spin-orbit coupling. PMID:26059464

  8. Excited states and valley effects in a negatively charged impurity in a silicon FinFET.

    SciTech Connect

    Hollenberg, Lloyd; Klimeck, Gerhard; Carroll, Malcolm S.; Rahman, Rajib; Muller, Richard Partain; Rogge, Sven; Verduijn, Arjan; Lansbergen, Gabriel

    2010-07-01

    The observation and characterization of a single atom system in silicon is a significant landmark in half a century of device miniaturization, and presents an important new laboratory for fundamental quantum and atomic physics. We compare with multi-million atom tight binding (TB) calculations the measurements of the spectrum of a single two-electron (2e) atom system in silicon - a negatively charged (D-) gated Arsenic donor in a FinFET. The TB method captures accurate single electron eigenstates of the device taking into account device geometry, donor potentials, applied fields, interfaces, and the full host bandstructure. In a previous work, the depths and fields of As donors in six device samples were established through excited state spectroscopy of the D0 electron and comparison with TB calculations. Using self-consistent field (SCF) TB, we computed the charging energies of the D- electron for the same six device samples, and found good agreement with the measurements. Although a bulk donor has only a bound singlet ground state and a charging energy of about 40 meV, calculations show that a gated donor near an interface can have a reduced charging energy and bound excited states in the D- spectrum. Measurements indeed reveal reduced charging energies and bound 2e excited states, at least one of which is a triplet. The calculations also show the influence of the host valley physics in the two-electron spectrum of the donor.

  9. Dependence of multiply charged ions on the polarization state in nanosecond laser-benzene cluster interaction

    NASA Astrophysics Data System (ADS)

    Wang, Weiguo; Zhao, Wuduo; Hua, Lei; Hou, Keyong; Li, Haiyang

    2016-05-01

    This paper investigated the dependence of multiply charged ions on the laser polarization state when benzene cluster was irradiated with 532 and 1064 nm nanosecond laser. A circle, square and flower distribution for C2+, C3+ and C4+ were observed with 532 nm laser respectively, while flower petals for C2+, C3+ and C4+ were observed at 1064 nm as the laser polarization varied. A theoretical calculation was performed to interpret the polarization state and wavelength dependence of the multiply charged ions. The simulated results agreed well with the experimental observation with considering the contribution from the cluster disintegration.

  10. Incipient charge order observed by NMR in the normal state of YBa2Cu3Oy

    PubMed Central

    Wu, Tao; Mayaffre, Hadrien; Krämer, Steffen; Horvatić, Mladen; Berthier, Claude; Hardy, W.N.; Liang, Ruixing; Bonn, D.A.; Julien, Marc-Henri

    2015-01-01

    The pseudogap regime of high-temperature cuprates harbours diverse manifestations of electronic ordering whose exact nature and universality remain debated. Here, we show that the short-ranged charge order recently reported in the normal state of YBa2Cu3Oy corresponds to a truly static modulation of the charge density. We also show that this modulation impacts on most electronic properties, that it appears jointly with intra-unit-cell nematic, but not magnetic, order, and that it exhibits differences with the charge density wave observed at lower temperatures in high magnetic fields. These observations prove mostly universal, they place new constraints on the origin of the charge density wave and they reveal that the charge modulation is pinned by native defects. Similarities with results in layered metals such as NbSe2, in which defects nucleate halos of incipient charge density wave at temperatures above the ordering transition, raise the possibility that order–parameter fluctuations, but no static order, would be observed in the normal state of most cuprates if disorder were absent. PMID:25751448

  11. Incipient charge order observed by NMR in the normal state of YBa2Cu3Oy

    NASA Astrophysics Data System (ADS)

    Wu, Tao; Mayaffre, Hadrien; Krämer, Steffen; Horvatić, Mladen; Berthier, Claude; Hardy, W. N.; Liang, Ruixing; Bonn, D. A.; Julien, Marc-Henri

    2015-03-01

    The pseudogap regime of high-temperature cuprates harbours diverse manifestations of electronic ordering whose exact nature and universality remain debated. Here, we show that the short-ranged charge order recently reported in the normal state of YBa2Cu3Oy corresponds to a truly static modulation of the charge density. We also show that this modulation impacts on most electronic properties, that it appears jointly with intra-unit-cell nematic, but not magnetic, order, and that it exhibits differences with the charge density wave observed at lower temperatures in high magnetic fields. These observations prove mostly universal, they place new constraints on the origin of the charge density wave and they reveal that the charge modulation is pinned by native defects. Similarities with results in layered metals such as NbSe2, in which defects nucleate halos of incipient charge density wave at temperatures above the ordering transition, raise the possibility that order-parameter fluctuations, but no static order, would be observed in the normal state of most cuprates if disorder were absent.

  12. Quantification of the solid-state charge mobility in a model radical polymer

    SciTech Connect

    Baradwaj, Aditya G.; Rostro, Lizbeth; Boudouris, Bryan W.; Alam, Muhammad A.

    2014-05-26

    We establish that an oft-used radical polymer, poly(2,2,6,6-tetramethylpiperidinyloxy methacrylate) (PTMA), has a solid-state hole mobility value on the order of 10{sup −4} cm{sup 2} V{sup −1} s{sup −1} in a space charge-limited device geometry. Despite being completely amorphous and lacking any π-conjugation, these results demonstrate that the hole mobility of PTMA is comparable to many well-studied conjugated polymers [e.g., poly(3-hexylthiophene)]. Furthermore, we show that the space charge-limited charge carrier mobility of these macromolecules is only a weak function of temperature, in contrast to many thermally-activated models of charge transport in polymeric materials. This key result demonstrates that the charge transport in radical polymers is inherently different than that in semicrystalline, conjugated polymers. These results establish the mechanism of solid-state charge transport in radical polymers and provide macromolecular design principles for this emerging class of organic electronic materials.

  13. High Charge State Ions Extracted from Metal Plasmas in the Transition Regime from Vacuum Spark to High Current Vacuum Arc

    SciTech Connect

    Yushkov, Georgy Yu.; Anders, A.

    2008-06-19

    Metal ions were extracted from pulsed discharge plasmas operating in the transition region between vacuum spark (transient high voltage of kV) and vacuum arc (arc voltage ~;; 20 V). At a peak current of about 4 kA, and with a pulse duration of 8 ?s, we observed mean ion charges states of about 6 for several cathode materials. In the case of platinum, the highest average charge state was 6.74 with ions of charge states as high as 10 present. For gold we found traces of charge state 11, with the highest average charge state of 7.25. At currents higher than 5 kA, non-metallic contaminations started to dominate the ion beam, preventing further enhancement of the metal charge states.

  14. Hospital charges to injured drinking drivers in Washington State: 1989-1993.

    PubMed

    Mueller, B A; Kenaston, T; Grossman, D; Salzberg, P

    1998-09-01

    The Washington State Patrol Crash Database and computerized hospitalization records for 1989-1993 were used to determine total hospital charges billed for motor vehicle collision injuries to drivers whose crash reports contained any indication of alcohol use. In this population-based study, total hospital charges were summed, and mean charges and lengths of stay were computed within alcohol use and insurance coverage status categories in an attempt to evaluate the hospital charges billed to public funding and private insurance. Of the total hospital charges for drivers with injuries from motor vehicle collisions for which a police-reported indicator of alcohol use status was available, 43% (U.S.$64.8 million) were for drivers who reportedly had been drinking. At the time of discharge, Medicaid was identified as the payor for 47% of these hospitalizations. The mean hospital charge billed per collision was greater for drinking (U.S.$18,258) than nondrinking drivers (U.S.$14,181). Drinking drivers also had longer hospital stays, even after adjustment for patient age, gender and injury severity. During this time in Washington state, the average annual amount billed at discharge for initial inpatient care of injuries to drivers who reportedly had been drinking at the time of the motor vehicle collision was U.S.$13 million. This includes only the amount assessed by the hospital at the time of discharge for treatment of the initial injury and does not include other related medical charges for rehabilitation or outpatient care, or for doctors' or laboratory fees. As increasing pressures of managed and capitated care lead to a shift of financial risk from the federal government and insurers to states and providers, the financial burden of specific, potentially preventable conditions such as this will receive greater attention. PMID:9678213

  15. Localized chemical switching of the charge state of nitrogen-vacancy luminescence centers in diamond

    SciTech Connect

    Shanley, Toby W.; Martin, Aiden A.; Aharonovich, Igor Toth, Milos

    2014-08-11

    We present a direct-write chemical technique for controlling the charge state of near-surface nitrogen vacancy centers (NVs) in diamond by surface fluorination. Fluorination of H-terminated diamond is realized by electron beam stimulated desorption of H{sub 2}O in the presence of NF{sub 3} and verified with environmental photoyield spectroscopy (EPYS) and photoluminescence (PL) spectroscopy. PL spectra of shallow NVs in H- and F-terminated nanodiamonds show the expected dependence of the NV charge state on their energetic position with respect to the Fermi-level. EPYS reveals a corresponding difference between the ionization potential of H- and F-terminated diamond. The electron beam fluorination process is highly localized and can be used to fluorinate H-terminated diamond, and to increase the population of negatively charged NV centers.

  16. Performance on the low charge state laser ion source in BNL

    SciTech Connect

    Okamura, M.; Alessi, J.; Beebe, E.; Costanzo, M.; DeSanto, L.; Jamilkowski, J.; Kanesue, T.; Lambiase, R.; Lehn, D.; Liaw, C. J.; McCafferty, D.; Morris, J.; Olsen, R.; Pikin, A.; Raparia, D.; Steszyn, A.; Ikeda, S.

    2015-09-07

    On March 2014, a Laser Ion Source (LIS) was commissioned which delivers high-brightness, low-charge-state heavy ions for the hadron accelerator complex in Brookhaven National Laboratory (BNL). Since then, the LIS has provided many heavy ion species successfully. The low-charge-state (mostly singly charged) beams are injected to the Electron Beam Ion Source (EBIS), where ions are then highly ionized to fit to the following accelerator’s Q/M acceptance, like Au32+. Recently we upgraded the LIS to be able to provide two different beams into EBIS on a pulse-to-pulse basis. Now the LIS is simultaneously providing beams for both the Relativistic Heavy Ion Collider (RHIC) and NASA Space Radiation Laboratory (NSRL).

  17. Ion Species and Charge States of Vacuum Arc Plasma with Gas Feed and Longitudinal Magnetic Field

    SciTech Connect

    Oks, Efim; Anders, Andre

    2010-06-23

    The evolution of copper ion species and charge state distributions is measured for a long vacuum arc discharge plasma operated in the presence of a longitudinal magnetic field of several 10 mT and working gas (Ar). It was found that changing the cathode-anode distance within 20 cm as well as increasing the gas pressure did not affect the arc burning voltage and power dissipation by much. In contrast, burning voltage and power dissipation were greatly increased as the magnetic field was increased. The longer the discharge gap the greater was the fraction of gaseous ions and the lower the fraction of metal ions, while the mean ion charge state was reduced. It is argued that the results are affected by charge exchange collisions and electron impact ionization.

  18. 1976-77 Student Charges at State and Land-Grant Universities (Tuition, Required Fees, Room and Board).

    ERIC Educational Resources Information Center

    National Association of State Universities and Land-Grant Colleges, Washington, DC. Office of Research and Information.

    The annual report on student charges for state and land grant colleges and universities shows substantial increases in student charges over the previous year. The median tuition rose 10 percent for in-state undergraduate students and 12.5 percent for out-of-state students. Increases in room and board and other student fees were substantial but not…

  19. Matrix engineering, state filling, and charge transport in PbSe quantum dot solids

    NASA Astrophysics Data System (ADS)

    Law, Matt

    Colloidal semiconductor quantum dots (QDs) are attractive building blocks for solar photovoltaics (PV). In this talk, I will highlight our recent progress in designing PbX (X = S, Se, Te) QD thin film absorbers for next-generation PV. Basic requirements for QD absorber layers include efficient light absorption, charge separation, charge transport, and long-term stability. I begin by discussing QD film fabrication, charge transport physics, insights from theory, and evidence that the carrier diffusion length is short and limited by electronic states in the QD band gap. Studies of carrier mobility as a function of basic film parameters such as inter-QD spacing, QD size, and QD size distribution have led to a better understanding of charge transport within highly disordered QD films. Efforts to improve carrier mobility by enhancing inter-dot electronic coupling, passivating surface states, and implementing surface doping will be highlighted. Engineering the inter-QD matrix to produce QD/inorganic or QD/organic nanocomposites is presented as a powerful way to optimize coupling, remove surface states, eliminate hysteretic charge trapping and ion motion, and achieve long-term environmental stability for high-performance, robust QD films that feature good carrier multiplication efficiency. New results on the use of atomic layer deposition infilling of QD films to yield all-inorganic QD transistors free of the bias-stress effect will be presented, and the likely role of ion transport in QD optoelectronics discussed. The use of infrared transmission spectroscopy to understand state filling and study charge transport in QD thin film transistors will be presented.

  20. A novel method for the injection and manipulation of magnetic charge states in nanostructures.

    PubMed

    Gartside, J C; Burn, D M; Cohen, L F; Branford, W R

    2016-01-01

    Realising the promise of next-generation magnetic nanotechnologies is contingent on the development of novel methods for controlling magnetic states at the nanoscale. There is currently demand for simple and flexible techniques to access exotic magnetisation states without convoluted fabrication and application processes. 360° domain walls (metastable twists in magnetisation separating two domains with parallel magnetisation) are one such state, which is currently of great interest in data storage and magnonics. Here, we demonstrate a straightforward and powerful process whereby a moving magnetic charge, provided experimentally by a magnetic force microscope tip, can write and manipulate magnetic charge states in ferromagnetic nanowires. The method is applicable to a wide range of nanowire architectures with considerable benefits over existing techniques. We confirm the method's efficacy via the injection and spatial manipulation of 360° domain walls in Py and Co nanowires. Experimental results are supported by micromagnetic simulations of the tip-nanowire interaction. PMID:27615372

  1. 42 CFR 447.68 - Alternative copayments, coinsurance, deductibles, or similar cost sharing charges: State plan...

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 42 Public Health 4 2013-10-01 2013-10-01 false Alternative copayments, coinsurance, deductibles, or similar cost sharing charges: State plan requirements. 447.68 Section 447.68 Public Health CENTERS FOR MEDICARE & MEDICAID SERVICES, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED)...

  2. 42 CFR 447.68 - Alternative copayments, coinsurance, deductibles, or similar cost sharing charges: State plan...

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 42 Public Health 4 2011-10-01 2011-10-01 false Alternative copayments, coinsurance, deductibles, or similar cost sharing charges: State plan requirements. 447.68 Section 447.68 Public Health CENTERS FOR MEDICARE & MEDICAID SERVICES, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED)...

  3. 42 CFR 447.68 - Alternative copayments, coinsurance, deductibles, or similar cost sharing charges: State plan...

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 42 Public Health 4 2012-10-01 2012-10-01 false Alternative copayments, coinsurance, deductibles, or similar cost sharing charges: State plan requirements. 447.68 Section 447.68 Public Health CENTERS FOR MEDICARE & MEDICAID SERVICES, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED)...

  4. Solvent-induced reversible solid-state colour change of an intramolecular charge-transfer complex.

    PubMed

    Li, Ping; Maier, Josef M; Hwang, Jungwun; Smith, Mark D; Krause, Jeanette A; Mullis, Brian T; Strickland, Sharon M S; Shimizu, Ken D

    2015-10-11

    A dynamic intramolecular charge-transfer (CT) complex was designed that displayed reversible colour changes in the solid-state when treated with different organic solvents. The origins of the dichromatism were shown to be due to solvent-inclusion, which induced changes in the relative orientations of the donor pyrene and acceptor naphthalenediimide units. PMID:26299357

  5. The excited spin-triplet state of a charged exciton in quantum dots.

    PubMed

    Molas, M R; Nicolet, A A L; Piętka, B; Babiński, A; Potemski, M

    2016-09-14

    We report on spectroscopic studies of resonances related to ladder of states of a charged exciton in single GaAlAs/AlAs quantum dot structures. Polarization-resolved photoluminescence, photoluminescence excitation and photon-correlation measurements were performed at low (T  =  4.2 K) temperature also in magnetic field applied in Faraday configuration. The investigated resonances are assigned to three different configurations of a positively charged exciton. Together with a singlet ground state and a conventional triplet state (involving an electron from the ground state electronic s-shell), an excited triplet state, which involved an electron from the excited electronic p-shell was identified in single dots. The appearance of an emission line related to the latter complex is due to a partially suppressed electron relaxation in the investigated dots. An analysis of this emission line allows us to scrupulously determine properties of the excited triplet state and compare them with those of the conventional triplet state. Both triplets exhibit similar patterns of anisotropic fine structure and Zeeman splitting, however their amplitudes significantly differ for those two states. Presented results emphasize the role of the symmetry of the electronic state on the properties of the triplet states of two holes  +  electron excitonic complex. PMID:27391126

  6. The excited spin-triplet state of a charged exciton in quantum dots

    NASA Astrophysics Data System (ADS)

    Molas, M. R.; Nicolet, A. A. L.; Piętka, B.; Babiński, A.; Potemski, M.

    2016-09-01

    We report on spectroscopic studies of resonances related to ladder of states of a charged exciton in single GaAlAs/AlAs quantum dot structures. Polarization-resolved photoluminescence, photoluminescence excitation and photon-correlation measurements were performed at low (T  =  4.2 K) temperature also in magnetic field applied in Faraday configuration. The investigated resonances are assigned to three different configurations of a positively charged exciton. Together with a singlet ground state and a conventional triplet state (involving an electron from the ground state electronic s-shell), an excited triplet state, which involved an electron from the excited electronic p-shell was identified in single dots. The appearance of an emission line related to the latter complex is due to a partially suppressed electron relaxation in the investigated dots. An analysis of this emission line allows us to scrupulously determine properties of the excited triplet state and compare them with those of the conventional triplet state. Both triplets exhibit similar patterns of anisotropic fine structure and Zeeman splitting, however their amplitudes significantly differ for those two states. Presented results emphasize the role of the symmetry of the electronic state on the properties of the triplet states of two holes  +  electron excitonic complex.

  7. Absolute nuclear material assay

    DOEpatents

    Prasad, Manoj K.; Snyderman, Neal J.; Rowland, Mark S.

    2012-05-15

    A method of absolute nuclear material assay of an unknown source comprising counting neutrons from the unknown source and providing an absolute nuclear material assay utilizing a model to optimally compare to the measured count distributions. In one embodiment, the step of providing an absolute nuclear material assay comprises utilizing a random sampling of analytically computed fission chain distributions to generate a continuous time-evolving sequence of event-counts by spreading the fission chain distribution in time.

  8. Absolute nuclear material assay

    DOEpatents

    Prasad, Manoj K.; Snyderman, Neal J.; Rowland, Mark S.

    2010-07-13

    A method of absolute nuclear material assay of an unknown source comprising counting neutrons from the unknown source and providing an absolute nuclear material assay utilizing a model to optimally compare to the measured count distributions. In one embodiment, the step of providing an absolute nuclear material assay comprises utilizing a random sampling of analytically computed fission chain distributions to generate a continuous time-evolving sequence of event-counts by spreading the fission chain distribution in time.

  9. Comparison of charge state distribution in commercially available sulfated cyclodextrins used as chiral resolving agents in capillary electrophoresis.

    PubMed

    Estrada, Roy; Vigh, Gyula

    2012-02-24

    The charge state distributions of randomly sulfated cyclodextrins from Sigma-Aldrich and Beckman-Coulter, as well as single isomer sulfated cyclodextrins from TM Chemicals LP were investigated using hydrophilic interaction liquid chromatography (HILIC). A cross-linked diol phase and an unbonded silica phase were used as HILIC stationary phases. Groups of sulfated cyclodextrins with different charge states were resolved from each other, while regioisomers in a charge group were partially separated. A ladder of sulfated cyclodextrins having a charge state distribution from 1 to 14 was prepared and was used to determine the charge state heterogeneity of the commercially available sulfated cyclodextrin samples. Wide charge state and regioisomer distributions are seen for the randomly sulfated cyclodextrins, while HILIC analysis of every single isomer sulfated cyclodextrin sample indicates the presence of a single species. PMID:21872870

  10. Diffusion Approach to Long Distance Charge Migration in DNA: Time-Dependent and Steady-State Analytical Solutions for the Product Yields

    PubMed Central

    Roginskaya, Marina; Razskazovskiy, Yuriy

    2007-01-01

    In this study we report analytical solutions for both time-dependent and steady-state problems of unbiased charge transfer through a regular DNA sequence via a hopping mechanism. The phenomenon is treated as a diffusion of charge in a one-dimensional array of equally spaced and energetically equivalent temporary trapping sites. The solutions take into account the rates of charge hopping (k), side reactions (kr), and charge transfer to a terminal charge acceptor (kt). A detailed analysis of the time-dependent problem is performed for the diffusion-controlled regime, i.e., under the assumption that kt ≫ k, which is also equivalent to the fast relaxation limit of charge trapping. The analysis shows that the kinetics of charge hopping through DNA is always multiexponential, but under certain circumstances it can be asymptotically approximated by a single-exponential term. In that case, the efficiency of charge transfer can be characterized by a single rate constant kCT = 1.23kN−2 + kr, where N is the DNA length expressed in terms of the number of equidistant trapping sites and kr is the rate of competing chemical processes. The absolute yield of charge transfer under steady-state conditions in general is obtained as Y∞ = ω [α sinh(αN) + ω cosh(αN)]−1, where α = (2kr/k)1/2 and ω = 2kt/k. For the diffusion-controlled regime and small N, in particular, it turns into the known “algebraic” dependence Y∞ = [1 + (kr/k)N2]−1. At large N the solution is asymptotically exponential with the parameter α mimicking the tunneling parameter β in agreement with earlier predictions. Similar equations and distance dependencies have also been obtained for the damage ratios at the intermediate and terminal trapping sites in DNA. The nonlinear least-squares fit of one of these equations to experimental yields of guanine oxidation available from the literature returns kinetic parameters that are in reasonable agreement with those obtained by Bixon et al. [Proc. Natl

  11. Energy and charge state dependences of transfer ionization to single capture ratio for fast multiply charged ions on helium

    NASA Astrophysics Data System (ADS)

    Unal, Ridvan

    The charge state and energy dependences of Transfer Ionization (TI) and Single Capture (SC) processes in collisions of multiply charged ions with He from intermediate to high velocities are investigated using coincident recoil ion momentum spectroscopy. The collision chamber is commissioned on the 15-degree port of a switching magnet, which allows the delivery of a beam with very little impurity. The target was provided from a supersonic He jet with a two-stage collimation. The two-stage, geometrically cooled, supersonic He jet has significantly reduced background contribution to the spectrum compared to a single stage He jet. In the case of a differentially pumped gas cell complex calculations based on assumptions for the correction due to the collisions with the contaminant beam led to corrections, which were up to 50%. The new setup allows one to make a direct separation of contaminant processes in the experimental data using the longitudinal momentum spectra. Furthermore, this correction is much smaller (about 8.8%) yielding better overall precision. The collision systems reported here are 1 MeV/u O(4--8)+ , 0.5--2.5 MeV/u F(4--9)+, 2.0 MeV/u Ti 15,17,18+, 1.6--1.75 MeV/u Cu18,20+ and 0.25--0.5 MeV/u I(15--25)+ ions interacting with helium. We have determined the sTIsSC ratio for high velocity highly charged ions on He at velocities in the range of 6 to 10 au and observed that the ratio is monotonically decreasing with velocity. Furthermore, we see a ratio that follows a q2 dependence up to approximately q = 9. Above q = 9 the experimental values exceed the q2 dependence prediction due to antiscreening. C. D. Lin and H. C. Tseng have performed coupled channel calculations for the energy dependence of TI and SC for F9+ + He and find values slightly higher than our measured values, but with approximately the same energy dependence. The new data, Si, Ti and Cu, go up only to q = 20 and show a smooth monotonically increasing TI/SC ratio. The TI/SC ratio for I (15

  12. Ultrafast twisting dynamics of thioflavin-T: spectroscopy of the twisted intramolecular charge-transfer state.

    PubMed

    Ghosh, Rajib; Palit, Dipak K

    2014-12-15

    Understanding the excited-state properties of thioflavin-T (ThT) has been of immense importance, because of its efficient amyloid-sensing ability related to neurodegenerative disorders. The excited-state dynamics of ThT is studied by using sub-pico- and nanosecond time-resolved transient absorption techniques as well as density functional theory (DFT)/time-dependent DFT calculations. Barrierless twisting around the central C-C bond between two aromatic moieties is the dominant process that contributes to the ultrafast dynamics of the S1 state. The spectroscopic properties of the intramolecular charge-transfer state are characterized for the first time. The energetics of the S0 and S1 states has also been correlated with the experimentally observed spectroscopic parameters and structural dynamics. A longer-lived transient state populated with a very low yield has been characterized as the triplet state. PMID:25251013

  13. UV-Induced Charge Transfer States in DNA Promote Sequence Selective Self-Repair.

    PubMed

    Bucher, Dominik Benjamin; Kufner, Corinna Lucia; Schlueter, Alexander; Carell, Thomas; Zinth, Wolfgang

    2016-01-13

    Absorption of UV-radiation in nucleotides initiates a number of photophysical and photochemical processes, which may finally cause DNA damage. One major decay channel of photoexcited DNA leads to reactive charge transfer states. This study shows that these states trigger self-repair of DNA photolesions. The experiments were performed by UV spectroscopy and HPLC on different single and double stranded oligonucleotides containing a cyclobutane pyrimidine dimer (CPD) lesion. In a first experiment we show that photoexcitation of adenine adjacent to a CPD has no influence on this lesion. However, excitation of a guanine (G) adenine (A) sequence leads to reformation of the intact thymine (T) bases. The involvement of two bases for the repair points to a long-living charge transfer state between G and A to be responsible for the repair. The negatively charged A radical anion donates an electron to the CPD, inducing ring splitting and repair. In contrast, a TA sequence, having an inverted charge distribution (T radical anion, A radical cation), is not able to repair the CPD lesion. The investigations show that the presence of an adjacent radical ion is not sufficient for repair. More likely it is the driving power represented by the oxidation potential of the radical ion, which controls the repair. Thus, repair capacities are strongly sequence-dependent, creating DNA regions with different tendencies of self-repair. This self-healing activity represents the simplest sequence-dependent DNA repair system. PMID:26651219

  14. Charge state and stopping dynamics of fast heavy ions in dense matter

    SciTech Connect

    Rosmej, O. N.; Blazevic, A.; Korostiy, S.; Bock, R.; Hoffmann, D. H. H.; Pikuz, S. A. Jr.; Efremov, V. P.; Fortov, V. E.; Fertman, A.; Mutin, T.; Pikuz, T. A.; Faenov, A. Ya.

    2005-11-15

    K-shell radiation of fast heavy ions penetrating solid matter was used to analyze the stopping dynamics of ions over more than 80% of the stopping path. The most important advantage of this method is that the data is obtained with a high spatial resolution directly from the interaction volume. In experiments 11.4 MeV/u Ca projectile were slowed down in solid quartz and low-density SiO{sub 2} aerogel targets. Characteristic projectile and target spectra in the photon energy range of 1.5-4 keV were registered by means of spherically bent crystal spectrometers with high spectral and spatial resolution in the direction of the ion beam propagation. K-shell spectra of heavy ions induced by close collisions with target atoms provided information about the projectile charge state and velocity dynamics. The line intensity distribution of the K-shell transitions arising from ions with different ion charges represents the charge state distribution along the ion beam track. The variation of the line Doppler shift due to the ion deceleration in the target material was used to determine the ion velocity dynamics. The spectroscopic analysis of the stopping process was complemented by measurements of the energy loss and ion charge state distribution after the ion beam emerged from the target using a standard time-of-flight method and magnet spectrometer.

  15. Modeling of direct beam extraction for a high-charge-state fusion driver

    NASA Astrophysics Data System (ADS)

    Anderson, O. A.; Grant Logan, B.

    A newly proposed type of multicharged ion source offers the possibility of an economically advantageous high-charge-state fusion driver. Multiphoton absorption in an intense uniform laser focus can give multiple charge states of high purity, simplifying or eliminating the need for charge-state separation downstream. Very large currents (hundreds of amperes) can be extracted from this type of source. Several arrangements are possible. For example, the laser plasma could be tailored for storage in a magnetic bucket, with beam extracted from the bucket. A different approach, described in this report, is direct beam extraction from the expanding laser plasma. We discuss extraction and focusing for the particular case of a 4.1 MV beam of Xe 16+ ions. The maximum duration of the beam pulse is limited by the total charge in the plasma, while the practical pulse length is determined by the range of plasma radii over which good beam optics can be achieved. The extraction electrode contains a solenoid for beam focusing. Our design studies were carried out first with an envelope code and then with a self-consistent particle code. Results from our initial model showed that hundreds of amperes could be extracted, but that most of this current missed the solenoid entrance or was intercepted by the wall and that only a few amperes were able to pass through. We conclude with an improved design which increases the surviving beam to more than 70 A.

  16. Measurements of Charge States of Solar Energetic Ions Observed by the STEREO Instruments

    NASA Astrophysics Data System (ADS)

    Dietrich, W. F.; Tylka, A. J.

    2012-12-01

    The measurements of the Time To Maximums (TTMs) of elemental particle rates in Solar Energetic Particle events employing near Earth instruments in space affords a method by which the charge states of ions, and in particular Fe, can indirectly measured for some SEP events. For some events the TTM is observed to vary strongly as some function of energy and charge to mass ratio (Q/M). When the observed TTMs are plotted as a function of rigidity, the TTMS are seen to vary inversely as a power law over a substantial energy range. The difference between the Q/M ratio of protons and heavier ions (generally near 2) allows the establishment of the spectral index alpha, when the TTMs are plotted not as a function of rigidity R, but instead as β R** α ,where. β is v/c, and α frequently near 1/2. The loci of all the TTMs should be the same for Q>1 ions that are fully stripped, and to the degree they are not, the charge state assumed can be reduced to bring the TTMs for these species into concert with the remainder. The results are clearest for Fe. Because the method depends only on TTMs, we can explore the possibility measuring ion charge states at the STEREO spacecraft as we have done with near Earth instruments.

  17. State-selective charge transfer in ion-ion interactions at intermediate and high energies

    NASA Astrophysics Data System (ADS)

    Samanta, R.; Purkait, M.; Mandal, C. R.

    2010-12-01

    The total and state-selective cross sections for charge transfer in H++He+, He2++Li2+, He2++He+ and Li3++Li2+ collisions were calculated using the boundary corrected continuum intermediate state approximation with an energy range of 30-2000 keV amu-1. In this model, distortion in the final channel related to the Coulomb continuum states of the projectile ion and the electron in the field of the residual target is included. The sub-shell distribution of total charge transfer cross section has been reported in tabular form. Comparison of the results is made with those of other recent theoretical investigations and experimental findings. The present results are found to be in very good agreement with the available experimental findings.

  18. Quantum states emerging from charged transformation-wave in a uniform magnetic field

    NASA Astrophysics Data System (ADS)

    Lin, De-Hone

    2016-06-01

    It is the purpose of this paper to investigate the behavior of a charged transformation-wave in a uniform magnetic field. We first derive the equation which a transformation-wave needs to satisfy, and then, as the main application, the magnetic duality of the Hooke-Newton transmutation is performed by a conformal mapping which generates the novel states with the following characteristics: (a) bound or scattering states are classified by the signatures of the quantum number of the angular momentum and the charge of the particle; (b) the angular momentum satisfies the half-integer quantization rule; and (c) the mass parameter to reach the states is isotropic. Finally, as an alternative application, we report the construction of the fractional angular momentum and fractional Landau levels with the transformation design method.

  19. Full control of quadruple quantum dot circuit charge states in the single electron regime

    SciTech Connect

    Delbecq, M. R. Nakajima, T.; Otsuka, T.; Amaha, S.; Watson, J. D.; Manfra, M. J.; Tarucha, S.

    2014-05-05

    We report the realization of an array of four tunnel coupled quantum dots in the single electron regime, which is the first required step toward a scalable solid state spin qubit architecture. We achieve an efficient tunability of the system but also find out that the conditions to realize spin blockade readout are not as straightforwardly obtained as for double and triple quantum dot circuits. We use a simple capacitive model of the series quadruple quantum dots circuit to investigate its complex charge state diagrams and are able to find the most suitable configurations for future Pauli spin blockade measurements. We then experimentally realize the corresponding charge states with a good agreement to our model.

  20. Full control of quadruple quantum dot circuit charge states in the single electron regime

    NASA Astrophysics Data System (ADS)

    Delbecq, M. R.; Nakajima, T.; Otsuka, T.; Amaha, S.; Watson, J. D.; Manfra, M. J.; Tarucha, S.

    2014-05-01

    We report the realization of an array of four tunnel coupled quantum dots in the single electron regime, which is the first required step toward a scalable solid state spin qubit architecture. We achieve an efficient tunability of the system but also find out that the conditions to realize spin blockade readout are not as straightforwardly obtained as for double and triple quantum dot circuits. We use a simple capacitive model of the series quadruple quantum dots circuit to investigate its complex charge state diagrams and are able to find the most suitable configurations for future Pauli spin blockade measurements. We then experimentally realize the corresponding charge states with a good agreement to our model.

  1. Atomistic simulations of negatively charged donor states probed in STM experiments

    NASA Astrophysics Data System (ADS)

    Tankasala, Archana; Salfi, Joe; Rogge, Sven; Klimeck, Gerhard; Rahman, Rajib

    A single donor in silicon binding two electrons (D-) is important for electron spin readout and two-qubit operations in a donor based silicon (Si) quantum computer, and has recently been probed in Scanning Tunneling Microscope (STM) experiments for sub-surface dopants. In this work, atomistic configuration interaction technique is used to compute the two-electron states of the donor taking into account the geometry of the STM-vacuum-silicon-reservoir device. While 45 meV charging energy is obtained for D- in bulk Si, the electrostatics of the device reduces the charging energy to 30 meVs. It is also shown that the reduced charging energy enables spin triplet states to be bound to the donor. The exchange splitting between the singlet and triplet states can be tuned by an external electric field. The computed wavefunctions of the D- state helps to understand how the contribution of the momentum space valley states change with donor depth and electric field.

  2. Charge density waves and local states in quasi-one-dimensional mixed valence inorganic complexes

    NASA Astrophysics Data System (ADS)

    Conradson, S. D.; Stroud, M. A.; Zietlow, M. H.; Swanson, B. I.; Baeriswyl, D.; Bishop, A. R.

    1988-02-01

    The ground state structures and local states associated with chemical defects in quasi-one-dimensional halogen ( X) bridged transition metal ( M) mixed valence solids of MX and MMX type have been studied. An adiabatic Hartree-Fock theoretical framework is presented and representative members are classified. The MX materials provide a class whose strong electron-phonon coupling usually favors a charge-density-wave (CDW) ground state. However, the coupling strength can be chemically tuned (e.g., by extension to MMX systems) or altered by pressure, driving the ground state structures towards, e.g., a bond-order-wave (BOW) phase. Electron-phonon driven self-trapped states are expected in both the CDW or BOW regimes. Resonance Raman spectra of the MMX solid K 4[Pt 2(P 2O 5H 2) 4Cl]·H 2O show, in addition to the homogeneous ground state modes, sharp new features with excitation profiles shifted to the red of the intervalence-charge-transfer (IVCT) band. We attribute these new bands to a local polaron state formed by oxidation of the Pt 2Cl chain by a chemical defect. The observed spectral characteristics of this local state are in good agreement with theoretical predictions.

  3. Role of mid-gap states in charge transport and photoconductivity in semiconductor nanocrystal films

    SciTech Connect

    Nagpal, Prashant; Klimov, Victor I.

    2011-09-27

    Colloidal semiconductor nanocrystals have attracted significant interest for applications in solution-processable devices such as light-emitting diodes and solar cells. However, a poor understanding of charge transport in nanocrystal assemblies, specifically the relation between electrical conductance in dark and under light illumination, hinders their technological applicability. Here we simultaneously address the issues of 'dark' transport and photoconductivity in films of PbS nanocrystals, by incorporating them into optical field-effect transistors in which the channel conductance is controlled by both gate voltage and incident radiation. Spectrally resolved photoresponses of these devices reveal a weakly conductive mid-gap band that is responsible for charge transport in dark. The mechanism for conductance, however, changes under illumination when it becomes dominated by band-edge quantized states. In this case, the mid-gap band still has an important role as its occupancy (tuned by the gate voltage) controls the dynamics of band-edge charges.

  4. Ionic charge states of solar energetic particles - Effects of flare X-rays

    NASA Technical Reports Server (NTRS)

    Mullan, D. J.; Waldron, W. L.

    1986-01-01

    Ionic charge states of solar energetic particles (SEP) from three flares have been reported by Luhn et al. (1984). Interpretations of the mean charges in terms of a source temperature Ts (assuming collisional ionization equilibrium) yield inconsistent results. For Mg, the required Ts (up to 8 x 10 to the 6th K) are larger than for N and Si by factors of up to 5. Here it is pointed out that flare X-rays photoionize the ambient corona, causing apparent ionization temperatures there to exceed the local electron temperature, Te. Using realistic flare X-ray fluxes, it is shown that the charge data for six elements (C, N, Ne, Mg, Si, and S) can be fitted if the source is at coronal temperatures (Te = 1-2 x 10 to the 6th K), but the ionization equilibrium is radiation dominated. For oxygen, a slight inconsistency persists in the three flares.

  5. Excited state and charge-carrier dynamics in perovskite solar cell materials.

    PubMed

    Ponseca, Carlito S; Tian, Yuxi; Sundström, Villy; Scheblykin, Ivan G

    2016-02-26

    Organo-metal halide perovskites (OMHPs) have attracted enormous interest in recent years as materials for application in optoelectronics and solar energy conversion. These hybrid semiconductors seem to have the potential to challenge traditional silicon technology. In this review we will give an account of the recent development in the understanding of the fundamental light-induced processes in OMHPs from charge-photo generation, migration of charge carries through the materials and finally their recombination. Our and other literature reports on time-resolved conductivity, transient absorption and photoluminescence properties are used to paint a picture of how we currently see the fundamental excited state and charge-carrier dynamics. We will also show that there is still no fully coherent picture of the processes in OMHPs and we will indicate the problems to be solved by future research. PMID:26820442

  6. The evolution of ion charge states in cathodic vacuum arc plasmas: a review

    SciTech Connect

    Anders, Andre

    2011-12-18

    Cathodic vacuum arc plasmas are known to contain multiply charged ions. 20 years after “Pressure Ionization: its role in metal vapour vacuum arc plasmas and ion sources” appeared in vol. 1 of Plasma Sources Science and Technology, it is a great opportunity to re-visit the issue of pressure ionization, a non-ideal plasma effect, and put it in perspective to the many other factors that influence observable charge state distributions, such as the role of the cathode material, the path in the density-temperature phase diagram, the “noise” in vacuum arc plasma as described by a fractal model approach, the effects of external magnetic fields and charge exchange collisions with neutrals. A much more complex image of the vacuum arc plasma emerges putting decades of experimentation and modeling in perspective.

  7. Excited state and charge-carrier dynamics in perovskite solar cell materials

    NASA Astrophysics Data System (ADS)

    Ponseca, Carlito S., Jr.; Tian, Yuxi; Sundström, Villy; Scheblykin, Ivan G.

    2016-02-01

    Organo-metal halide perovskites (OMHPs) have attracted enormous interest in recent years as materials for application in optoelectronics and solar energy conversion. These hybrid semiconductors seem to have the potential to challenge traditional silicon technology. In this review we will give an account of the recent development in the understanding of the fundamental light-induced processes in OMHPs from charge-photo generation, migration of charge carries through the materials and finally their recombination. Our and other literature reports on time-resolved conductivity, transient absorption and photoluminescence properties are used to paint a picture of how we currently see the fundamental excited state and charge-carrier dynamics. We will also show that there is still no fully coherent picture of the processes in OMHPs and we will indicate the problems to be solved by future research.

  8. Role of mid-gap states in charge transport and photoconductivity in semiconductor nanocrystal films

    PubMed Central

    Nagpal, Prashant; Klimov, Victor I.

    2011-01-01

    Colloidal semiconductor nanocrystals have attracted significant interest for applications in solution-processable devices such as light-emitting diodes and solar cells. However, a poor understanding of charge transport in nanocrystal assemblies, specifically the relation between electrical conductance in dark and under light illumination, hinders their technological applicability. Here we simultaneously address the issues of 'dark' transport and photoconductivity in films of PbS nanocrystals, by incorporating them into optical field-effect transistors in which the channel conductance is controlled by both gate voltage and incident radiation. Spectrally resolved photoresponses of these devices reveal a weakly conductive mid-gap band that is responsible for charge transport in dark. The mechanism for conductance, however, changes under illumination when it becomes dominated by band-edge quantized states. In this case, the mid-gap band still has an important role as its occupancy (tuned by the gate voltage) controls the dynamics of band-edge charges. PMID:21952220

  9. High charge state carbon and oxygen ions in Earth's equatorial quasi-trapping region

    NASA Technical Reports Server (NTRS)

    Christon, S. P.; Hamilton, D. C.; Gloeckler, G.; Eastmann, T. E.

    1994-01-01

    Observations of energetic (1.5 - 300 keV/e) medium-to-high charge state (+3 less than or equal to Q less than or equal to +7) solar wind origin C and O ions made in the quasi-trapping region (QTR) of Earth's magnetosphere are compared to ion trajectories calculated in model equatorial magnetospheric magnetic and electric fields. These comparisons indicate that solar wind ions entering the QTR on the nightside as an energetic component of the plasma sheet exit the region on the dayside, experiencing little or no charge exchange on the way. Measurements made by the CHarge Energy Mass (CHEM) ion spectrometer on board the Active Magnetospheric Particle Tracer Explorer/Charge Composition Explorer (AMPTE/CCE) spacecraft at 7 less than L less than 9 from September 1984 to January 1989 are the source of the new results contained herein: quantitative long-term determination of number densities, average energies, energy spectra, local time distributions, and their variation with geomagnetic disturbance level as indexed by Kp. Solar wind primaries (ions with charge states unchanged) and their secondaries (ions with generally lower charge states produced from primaries in the magnetosphere via charge exchange)are observed throughout the QTR and have distinctly different local time variations that persist over the entire 4-year analysis interval. During Kp larger than or equal to 3 deg intervals, primary ion (e.g., O(+6)) densities exhibit a pronounced predawn maximum with average energy minimum and a broad near-local-noon density minimum with average energy maximum. Secondary ion (e.g., O(+5)) densities do not have an identifiable predawn peak, rather they have a broad dayside maximum peaked in local morning and a nightside minimum. During Kp less than or equal to 2(-) intervals, primary ion density peaks are less intense, broader in local time extent, and centered near midnight, while secondary ion density local time variations diminish. The long-time-interval baseline helps

  10. Energy-dependent Charge States and Their Connection with Ion Abundances in Impulsive Solar Energetic Particle Events

    NASA Astrophysics Data System (ADS)

    DiFabio, R.; Guo, Z.; Möbius, E.; Klecker, B.; Kucharek, H.; Mason, G. M.; Popecki, M.

    2008-11-01

    Impulsive solar energetic particle (SEP) events show substantial enhancements of heavy ions and 3He over the composition in the Sun's atmosphere. Mass per charge dependent acceleration mechanisms have been proposed to account for this preferential acceleration. However, a problem emerged for all the preferential acceleration models with the measurement of ionization states near 1 MeV nucleon-1, which showed that ions from C to Mg are fully stripped, a challenge that had been recognized early on. Since all models relied on differences in the charge-to-mass ratio to enable preferential acceleration, the proposed mechanisms were incompatible with this observation. Recent observations of the ionic charge states at lower energies have revealed a dependence on energy, with the charge states decreasing for lower energy ions. This raises the possibility that the low-energy charge states reflect the plasma conditions at the acceleration site, while the high-energy charge states are due to stripping low in the solar corona. In a survey of impulsive events we show that the increase of the Fe charge states with energy is highly significant for the sample of events and thus most likely a general feature of impulsive events. To see whether there is a connection between the enhancements and charge states, we extended the ACE SEPICA charge-state observations to lower energies and combined them with the ion fluxes from ACE ULEIS for impulsive events observed between 1997 and 2000. We find a positive correlation between the abundance ratios and the charge states at low energy, while the charge states at the highest energy do not demonstrate such dependence. This supports the idea that the higher mass particles are preferentially accelerated before being stripped.

  11. Investigation Of The EMF Versus State Of Charge Behavior Of Individual Electrodes In New And Cycled Sony 18650 HC Cells

    NASA Astrophysics Data System (ADS)

    Dudley, G.; Mattle, T.

    2011-10-01

    Individual electrode EMFs of new and cycled Sony 18650 HC cells have been measured with the help of a lithium reference electrode inserted into complete cells. Results have revealed the relative contribution of each electrode to voltage hysteresis (the difference in cell EMF between charge and discharge at the same state of charge).They have also shown changes to the shape of the positive electrode EMF versus state of charge in cycled compared to beginning of life cells.

  12. The s-channel charged Higgs in the fully hadronic final state at LHC

    NASA Astrophysics Data System (ADS)

    Ahmed, Ijaz; Hashemi, Majid; Tajuddin, Wan Ahmad

    2016-04-01

    With the current measurements performed by CMS and ATLAS experiments, the light charged Higgs scenario (m_{H^{± }} < 160 GeV), is excluded for most of the parameter space in the context of MSSM. However, there is still possibility to look for heavy charged Higgs boson particularly in the s-channel single top production process where the charged Higgs may appear as a heavy resonance state and decay to tbar{b}. The production process under consideration in this paper is pp → H^{± } → tbar{b} + h.c., where the top quark decays to W+b and W+ boson subsequently decays to two light jets. It is shown that despite the presence of large QCD and electroweak background events, the charged Higgs signal can be extracted and observed at a large area of MSSM parameter space (m_{H^{± }}, tanβ ) at LHC. The observability of charged Higgs is potentially demonstrated with 5σ contours and 95 % confidence level exclusion curves at different integrated LHC luminosities assuming a nominal center of mass energy of √{s} = 14 TeV.

  13. Measurement of Absolute Carbon Isotope Ratios: Mechanisms and Implications

    NASA Astrophysics Data System (ADS)

    Vogel, J. S.; Giacomo, J. A.; Dueker, S. R.

    2012-12-01

    An accelerator mass spectrometer (AMS) produced absolute isotope ratio measurements for 14C/13C as tested against >500 samples of NIST SRM-4990-C (OxII 14C standard) to an accuracy of 2.2±0.6‰ over a period of one year with measurements made to 1% counting statistics. The spectrometer is not maximized for 13C/12C, but measured ∂13C to 0.4±0.1‰ accuracy, with known methods for improvement. An AMS produces elemental anions from a sputter ion source and includes a charge-changing collision in a gas cell to isolate the rare 14C from the common isotopes and molecular isobars. Both these physical processes have been modeled to determine the parameters providing such absolute measures. Neutral resonant ionization in a cesium plasma produces mass-independent ionization, while velocity dependent charge-state distributions in gas collisions produce relative ion beam intensities that are linear in mass at specific collision energies. The mechanisms are not specific to carbon isotopes, but stand alone absolute IRMS (AIR-MS) instruments have not yet been made. Aside from the obvious applications in metrology, AIR-MS is particularly valuable in coupled separatory MS because no internal or external standards are required. Sample definition processes can be compared, even if no exact standard reference sample exists. Isotope dilution measurements do not require standards matching the dilution end-points and can be made over an extended, even extrapolated, range.

  14. Charge state dynamics of the nitrogen vacancy center in diamond under near-infrared excitation

    NASA Astrophysics Data System (ADS)

    Ji, Peng; Dutt, M. V. Gurudev

    2016-05-01

    The negatively charged NV defect center (NV-) in diamond has become prominent for applications in quantum information, nanoscale magnetic and electric field sensing, and fluorescent biological markers. Switching between NV- and neutral charge states (NV0) have been extensively studied and modeled using exciting laser wavelengths that are shorter than the NV- zero-phonon line (ZPL), and typically result in decreased fluorescence from the NV- state. In this work, we report on the experimental observation that NV0 converts to NV- under excitation with near-infrared (1064 nm) light, resulting in increased fluorescence from the NV- state. We have observed this effect in both ensembles of NVs in bulk diamond, and in diamond nanocrystals, and find that it is robust both at room and low temperature. We carried out microwave and two-color excitation combined with spectral and time-resolved experimental studies. We used rate-equation modeling and find evidence for competition between one-photon and two-photon processes for hole and electron ionization. This finding may help elucidate the study of the NV energy level structure, and impact recently emerging research in single-shot measurement of the NV- spin state via spin-to-charge conversion.

  15. The study towards high intensity high charge state laser ion sources.

    PubMed

    Zhao, H Y; Jin, Q Y; Sha, S; Zhang, J J; Li, Z M; Liu, W; Sun, L T; Zhang, X Z; Zhao, H W

    2014-02-01

    As one of the candidate ion sources for a planned project, the High Intensity heavy-ion Accelerator Facility, a laser ion source has been being intensively studied at the Institute of Modern Physics in the past two years. The charge state distributions of ions produced by irradiating a pulsed 3 J/8 ns Nd:YAG laser on solid targets of a wide range of elements (C, Al, Ti, Ni, Ag, Ta, and Pb) were measured with an electrostatic ion analyzer spectrometer, which indicates that highly charged ions could be generated from low-to-medium mass elements with the present laser system, while the charge state distributions for high mass elements were relatively low. The shot-to-shot stability of ion pulses was monitored with a Faraday cup for carbon target. The fluctuations within ±2.5% for the peak current and total charge and ±6% for pulse duration were demonstrated with the present setup of the laser ion source, the suppression of which is still possible. PMID:24593615

  16. Toward A More General Technique to Infer Ionic Charge States of Solar Energetic Particles

    NASA Astrophysics Data System (ADS)

    Sollitt, L. S.; Aguirre, E. M.; Briggs, P.

    2011-12-01

    We report on a new method to infer charge states of high energy (≥ 10 MeV/nuc) solar energetic particles. We build on ideas developed in Sollitt (2004) and Sollitt et al. (2008); those papers indicated that in the decay phase of large well-connected solar particle events, particles of different species with the same rigidity (mv/q) exhibit similar decay profiles. Mason et al. (2006) suggested that these similarities extend to overall time-intensity profiles. Our method uses one-hour average particle flux data from the Solar Isotope Spectrometer (SIS) aboard the Advanced Composition Explorer (ACE) spacecraft. We choose a reference species (e.g. Carbon) for which the charge state is known to be stable over a wide range of energies. At each hour we construct a continuous reference energy profile using a cubic spline fit of the flux at the nominal passband energies. Then we best-fit the time profiles of target species (e.g. Iron) to the interpolated time profiles of the reference. Assuming that the matching profiles represent particles of the same rigidity, this analysis generates the ratio of the target species charge to the reference species charge.

  17. Charge and magnetic states of Mn-, Fe-, and Co-doped monolayer MoS{sub 2}

    SciTech Connect

    Lin, Xianqing; Ni, Jun

    2014-07-28

    First-principles calculations have been performed to investigate the electronic and magnetic properties of monolayer MoS{sub 2} substitutionally doped with Mn, Fe, and Co in possible charge states (q). We find that the Mn, Fe, and Co dopants substituting for a Mo atom in monolayer MoS{sub 2} (Mn@Mo, Fe@Mo, and Co@Mo) are all magnetic in their neutral and charge states except in the highest positive charge states. Mn@Mo, Fe@Mo, and Co@Mo have the same highest negative charge states of q=−2 for chemical potential of electron just below the conduction band minimum, which corresponds to the electron doping. In the q=−2 state, Mn@Mo has a much larger magnetic moment than its neutral state with the antiferromagnetic coupling between the Mn dopant and its neighboring S atoms maintained, while Fe@Mo and Co@Mo have equal or smaller magnetic moments than their neutral states. The possible charge states of Mn@Mo, Fe@Mo, and Co@Mo and the variation of the magnetic moments for different dopants and charge states are due to the change of the occupation and energy of the anti-bonding defect levels in the band gap. The rich magnetic properties of the neutral and charge states suggest possible realization of the substitutionally Mn-, Fe-, and Co-doped monolayer MoS{sub 2} as dilute magnetic semiconductors.

  18. Determination of the state-of-charge in leadacid batteries by means of a reference cell

    NASA Astrophysics Data System (ADS)

    Armenta, C.

    A knowledge of the state-of-charge of any battery is an essential requirement for system energy management and for battery life extension. In photovoltaic power plants and stand-alone photovoltaic installations, a knowledge of the state-of-charge helps one to predict remaining energy, to determine time remaining before battery turndown, and to avoid failures during operation. A reliable method of predicting the state-of-charge will allow reduced installation costs because less reserve capacity is needed to guarantee a reliable energy supply. We propose an on-line method based on simple electrical measurements combined with a new electrolyte agitation technique which avoids systematic control of the battery state-of-charge. The method is very accurate and reduces the standard error in the state-of-charge prediction.

  19. Influence of argon and oxygen on charge-state-resolved ion energy distributions of filtered aluminum arcs

    NASA Astrophysics Data System (ADS)

    Rosén, Johanna; Anders, André; Mráz, Stanislav; Atiser, Adil; Schneider, Jochen M.

    2006-06-01

    The charge-state-resolved ion energy distributions (IEDs) in filtered aluminum vacuum arc plasmas were measured and analyzed at different oxygen and argon pressures in the range of 0.5-8.0 mTorr. A significant reduction of the ion energy was detected as the pressure was increased, most pronounced in an argon environment and for the higher charge states. The corresponding average charge state decreased from 1.87 to 1.0 with increasing pressure. The IEDs of all metal ions in oxygen were fitted with shifted Maxwellian distributions. The results show that it is possible to obtain a plasma composition with a narrow charge-state distribution as well as a narrow IED. These data may enable tailoring thin film properties through selecting growth conditions that are characterized by predefined charge state and energy distributions.

  20. Contribution of material's surface layer on charge state distribution in laser ablation plasma.

    PubMed

    Kumaki, Masafumi; Steski, Dannie; Ikeda, Shunsuke; Kanesue, Takeshi; Okamura, Masahiro; Washio, Masakazu

    2016-02-01

    To generate laser ablation plasma, a pulse laser is focused onto a solid target making a crater on the surface. However, not all the evaporated material is efficiently converted to hot plasma. Some portion of the evaporated material could be turned to low temperature plasma or just vapor. To investigate the mechanism, we prepared an aluminum target coated by thin carbon layers. Then, we measured the ablation plasma properties with different carbon thicknesses on the aluminum plate. The results showed that C(6+) ions were generated only from the surface layer. The deep layers (over 250 nm from the surface) did not provide high charge state ions. On the other hand, low charge state ions were mainly produced by the deeper layers of the target. Atoms deeper than 1000 nm did not contribute to the ablation plasma formation. PMID:26931982

  1. Using Ion Injections to Infer the Energetic Oxygen and Sulfur Charge States in Jupiter's Inner and Middle Magnetosphere

    NASA Astrophysics Data System (ADS)

    Clark, G. B.; Mauk, B.; Paranicas, C.; Kollmann, P.; Mitchell, D. G.

    2015-12-01

    Neutral gases can, through the charge exchange processes, shape the distributions of energetic ions trapped within a planetary magnetosphere, and also redistribute the energetic ion charge states. One region where the prevalence of such processes has been proposed is the orbital region of Jupiter's moon Europa, where the existence of a neutral gas torus has been inferred. Data from the Galileo Energetic Particle Detector (EPD) showed a depletion of protons with near equatorial pitch angles near Europa, while oxygen and sulfur maintained their trapped profile as they were transported inward. The contrast in these distributions was attributed by Lagg et al. (2003) to the multiple charge states of the oxygen and sulfur, dramatically increasing the charge exchange lifetimes of these species. It was proposed that as the ions diffuse inwards across Europa's orbit and into the Io torus regions, the distributed neutral gas interactions redistribute the charge states of the heavy ions until, close to Io, these ions may be heavily depleted. And so, the charge state of the heavy ions is a critical parameter in determining whether or not these processes are taking place. Limited evidence for the multiple charged states of heavy ions was provided by Mauk et al. [1999], who analyzed three ion injection events and found evidence of multiply charged energetic oxygen and sulfur ions in two of the events, but not in the third event. Injections introduce a transient disturbance to the ion distributions, and the drift rate of disturbed ions away from the injection region depends on the charge state of the ions. In this work we revisit the Galileo EPD data set and find additional ion dispersion events from which composition can be measured and charge state can be inferred. We aspire to develop a much clearer picture as to the ordering of charge state as a function of radial distance. Results and conclusions will be presented as well as the importance from new measurements from the

  2. A model for charge transfer in ultracold Rydberg ground-state atomic collisions

    NASA Astrophysics Data System (ADS)

    Markson, Samuel; Sadeghpour, H. R.

    2016-06-01

    In excited molecules, the interaction between the covalent Rydberg and ion-pair channels forms a unique class of excited states, in which the infinite manifold of vibrational levels are the equivalent of atomic Rydberg states with a heavy electron mass. Production of the ion-pair states usually requires excitation through one or several interacting Rydberg states; these interacting channels lead to loss of flux, diminishing the rate of ion-pair production. Here, we develop an analytical, asymptotic charge-transfer model for the interaction between ultracold Rydberg molecular states, and employ this method to demonstrate the utility of off-resonant field control over the ion-pair formation, with near unity efficiency.

  3. A high gradient superconducting quadrupole for a low charge state ion linac

    SciTech Connect

    Kim, J.W.; Shepard, K.W.; Nolen, J.A.

    1995-07-01

    A superconducting quadrupole magnet has been designed for use as the focusing element in a low charge state linac proposed at Argonne. The expected field gradient is 350 T/m at an operating current of 53 A, and the bore diameter is 3 cm. The use of rare earth material holmium for pole tips provides about 10% more gradient then iron pole tips. The design and the status of construction of a prototype singlet magnet is described.

  4. Device and Method for Continuously Equalizing the Charge State of Lithium Ion Battery Cells

    NASA Technical Reports Server (NTRS)

    Schwartz, Paul D. (Inventor); Martin, Mark N. (Inventor); Roufberg, Lewis M. (Inventor)

    2015-01-01

    A method of equalizing charge states of individual cells in a battery includes measuring a previous cell voltage for each cell, measuring a previous shunt current for each cell, calculating, based on the previous cell voltage and the previous shunt current, an adjusted cell voltage for each cell, determining a lowest adjusted cell voltage from among the calculated adjusted cell voltages, and calculating a new shunt current for each cell.

  5. Interpreting Zcbold" (3900bold" ) and Zcbold" (4025bold" )/Zcbold" (4020bold" ) as charged tetraquark states

    NASA Astrophysics Data System (ADS)

    Deng, Chengrong; Ping, Jialun; Huang, Hongxia; Wang, Fan

    2014-09-01

    In the framework of the color flux-tube model with a four-body confinement potential, the lowest charged tetraquark states [Qq][Q¯'q¯'](Q=c,b,q=u,d,s) are studied by using the variational method, the Gaussian expansion method. The results indicate that some compact resonance states with three-dimensional spatial structures can be formed. These states cannot decay into two color singlet mesons Qq¯' and Q¯'q through the breakdown and recombination of color flux tubes but into QQ¯' and qq¯'. The four-body confinement potential is a crucial dynamical mechanism for the formation of these compact resonance states. The decay process is similar to that of a compound nucleus but due to the multibody color confinement. The newly observed charged states Zc(3900) and Zc(4025)/Zc(4020) can be interpreted as the S-wave tetraquark states [cu][c¯d¯] with quantum numbers IJP=11+ and 12+, respectively.

  6. On the maximum charge state and proton transfer reactivity of peptide and protein ions formed by electrospray ionization.

    PubMed

    Schnier, P D; Gross, D S; Williams, E R

    1995-11-01

    A relatively simple model for calculation of the energetics of gas-phase proton transfer reactions and the maximum charge state of multiply protonated ions formed by electrospray ionization is presented. This model is based on estimates of the intrinsic proton transfer reactivity of sites of protonation and point charge Coulomb interactions. From this model, apparent gas-phase basicities (GB(app)) of multiply protonated ions are calculated. Comparison of this value to the gas-phase basicity of the solvent from which an ion is formed enables a maximum charge state to be calculated. For 13 commonly electrosprayed proteins, our calculated maximum charge states are within an average of 6% of the experimental values reported in the literature. This indicates that the maximum charge state for proteins is determined by their gas-phase reactivity. Similar results are observed for peptides with many basic residues. For peptides with few basic residues, we find that the maximum charge state is better correlated to the charge state in solution. For low charge state ions, we find that the most basic sites Arg, Lys, and His are preferentially protonated. A significant fraction of the less basic residues Pro, Trp, and Gln are protonated in high charge state ions. The calculated GB(app) of individual protonation sites varies dramatically in the high charge state ions. From these values, we calculate a reduced cross section for proton transfer reactivity that is significantly lower than the Langevin collision frequency when the GB(app) of the ion is approximately equal to the GB of the neutral base. PMID:24214055

  7. Temporal evolution of ion energy distribution functions and ion charge states of Cr and Cr-Al pulsed arc plasmas

    SciTech Connect

    Tanaka, Koichi; Anders, André

    2015-11-15

    To study the temporal evolution of ion energy distribution functions, charge-state-resolved ion energy distribution functions of pulsed arc plasmas from Cr and Cr-Al cathodes were recorded with high time resolution by using direct data acquisition from a combined energy and mass analyzer. The authors find increases in intensities of singly charged ions, which is evidence that charge exchange reactions took place in both Cr and Cr-Al systems. In Cr-Al plasmas, the distributions of high-charge-state ions exhibit high energy tails 50 μs after discharge ignition, but no such tails were observed at 500 μs. The energy ratios of ions of different charge states at the beginning of the pulse, when less neutral atoms were in the space in front of the cathode, suggest that ions are accelerated by an electric field. The situation is not so clear after 50 μs due to particle collisions. The initial mean ion charge state of Cr was about the same in Cr and in Cr-Al plasmas, but it decreased more rapidly in Cr-Al plasmas compared to the decay in Cr plasma. The faster decay of the mean ion charge state and ion energy caused by the addition of Al into a pure Cr cathode suggests that the mean ion charge state is determined not only by ionization processes at the cathode spot but also by inelastic collision between different elements.

  8. Charge-transfer photodissociation of adsorbed molecules via electron image states

    SciTech Connect

    Jensen, E. T.

    2008-01-28

    The 248 and 193 nm photodissociations of submonolayer quantities of CH{sub 3}Br and CH{sub 3}I adsorbed on thin layers of n-hexane indicate that the dissociation is caused by dissociative electron attachment from subvacuum level photoelectrons created in the copper substrate. The characteristics of this photodissociation-translation energy distributions and coverage dependences show that the dissociation is mediated by an image potential state which temporarily traps the photoelectrons near the n-hexane-vacuum interface, and then the charge transfers from this image state to the affinity level of a coadsorbed halomethane which then dissociates.

  9. Gas-pressure dependence of charge-state fractions and mean charges of 1.4 MeV/u-uranium ions stripped in molecular hydrogen

    NASA Astrophysics Data System (ADS)

    Shevelko, V. P.; Winckler, N.; Tolstikhina, I. Yu.

    2016-06-01

    Using a recently created BREIT computer code (Balance Rate Equations for Ion Transportation), evolutions of the charge-state fractions Fq (x) and equilibrium mean charge states q bar are calculated for stripping of 1.4 MeV/u-U4+ ions in H2 gas for target thicknesses x ⩽ 100 μg /cm2 (⩽ 3 ·1019molecule /cm2) and gas pressures 10-4 ⩽ P ⩽ 500 mbar. Calculations of the non-equilibrium Fq (x) and equilibrium Fq0 distributions for ion charges 4 ⩽ q ⩽ 40 are performed by solving the balance (rate) equations with account for the multi-electron processes and the target-density effect. Calculated equilibrium mean charge state increases from q bar ≈ 27.6 at P =10-4 mbar to its saturated (maximum) value of q bar ≈ 32.7 at pressures P≳ 250 mbar while the equilibrium target thickness xeq increases from 20 to 50 μg /cm2 (from 0.6 to 1.5 in units of 1019molecule /cm2) in the H2-pressure range considered. From the present calculations it is concluded that the maximum mean charge state q bar which can be achieved in stripping of 1.4 MeV/u-U4+ ions in H2 gas is about q bar ≈ 33 at a gas pressure P≳ 250 mbar.

  10. Substituent and Solvent Effects on Excited State Charge Transfer Behavior of Highly Fluorescent Dyes Containing Thiophenylimidazole-Based Aldehydes

    NASA Technical Reports Server (NTRS)

    Santos, Javier; Bu, Xiu R.; Mintz, Eric A.

    2001-01-01

    The excited state charge transfer for a series of highly fluorescent dyes containing thiophenylimidazole moiety was investigated. These systems follow the Twisted Intramolecular Charge Transfer (TICT) model. Dual fluorescence was observed for each substituted dye. X-ray structures analysis reveals a twisted ground state geometry for the donor substituted aryl on the 4 and 5 position at the imidazole ring. The excited state charge transfer was modeled by a linear solvation energy relationship using Taft's pi and Dimroth's E(sub T)(30) as solvent parameters. There is linear relation between the energy of the fluorescence transition and solvent polarity. The degree of stabilization of the excited state charge transfer was found to be consistent with the intramolecular molecular charge transfer. Excited dipole moment was studied by utilizing the solvatochromic shift method.

  11. Multiple Charge Transfer States at Ordered and Disordered Donor/Acceptor Interfaces

    NASA Astrophysics Data System (ADS)

    Fusella, Michael; Verreet, Bregt; Lin, Yunhui; Brigeman, Alyssa; Purdum, Geoffrey; Loo, Yueh-Lin; Giebink, Noel; Rand, Barry

    The presence of charge transfer (CT) states in organic solar cells is accepted, but their role in photocurrent generation is not well understood. Here we investigate solar cells based on rubrene and C60 to show that CT state properties are influenced by molecular ordering at the donor/acceptor (D/A) interface. Crystalline rubrene films are produced with domains of 100s of microns adopting the orthorhombic phase, as confirmed by grazing incidence XRD, with the (h00) planes parallel to the substrate. C60 grown atop these films adopts a highly oriented face-centered cubic phase with the (111) plane parallel to the substrate. For this highly ordered system we have discovered the presence of four CT states. Polarized external quantum efficiency (EQE) measurements assign three of these to crystalline origins with the remaining one well aligned with the disordered CT state. Varying the thickness of a disordered blend of rubrene:C60 atop the rubrene template modulates the degree of crystallinity at the D/A interface. Strikingly, this process alters the prominence of the four CT states measured via EQE, and results in a transition from single to multiple electroluminescence peaks. These results underscore the impact of molecular structure at the heterojunction on charge photogeneration.

  12. Excited State Structural Dynamics of Carotenoids and ChargeTransfer Systems

    SciTech Connect

    Van Tassle, Aaron Justin

    2006-09-01

    This dissertation describes the development andimplementation of a visible/near infrared pump/mid-infrared probeapparatus. Chapter 1 describes the background and motivation ofinvestigating optically induced structural dynamics, paying specificattention to solvation and the excitation selection rules of highlysymmetric molecules such as carotenoids. Chapter 2 describes thedevelopment and construction of the experimental apparatus usedthroughout the remainder of this dissertation. Chapter 3 will discuss theinvestigation of DCM, a laser dye with a fluorescence signal resultingfrom a charge transfer state. By studying the dynamics of DCM and of itsmethyl deuterated isotopomer (an otherwise identical molecule), we areable to investigate the origins of the charge transfer state and provideevidence that it is of the controversial twisted intramolecular (TICT)type. Chapter 4 introduces the use of two-photon excitation to the S1state, combined with one-photon excitation to the S2 state of thecarotenoid beta-apo-8'-carotenal. These 2 investigations show evidencefor the formation of solitons, previously unobserved in molecular systemsand found only in conducting polymers Chapter 5 presents an investigationof the excited state dynamics of peridinin, the carotenoid responsiblefor the light harvesting of dinoflagellates. This investigation allowsfor a more detailed understanding of the importance of structuraldynamics of carotenoids in light harvesting.

  13. Absolute biological needs.

    PubMed

    McLeod, Stephen

    2014-07-01

    Absolute needs (as against instrumental needs) are independent of the ends, goals and purposes of personal agents. Against the view that the only needs are instrumental needs, David Wiggins and Garrett Thomson have defended absolute needs on the grounds that the verb 'need' has instrumental and absolute senses. While remaining neutral about it, this article does not adopt that approach. Instead, it suggests that there are absolute biological needs. The absolute nature of these needs is defended by appeal to: their objectivity (as against mind-dependence); the universality of the phenomenon of needing across the plant and animal kingdoms; the impossibility that biological needs depend wholly upon the exercise of the abilities characteristic of personal agency; the contention that the possession of biological needs is prior to the possession of the abilities characteristic of personal agency. Finally, three philosophical usages of 'normative' are distinguished. On two of these, to describe a phenomenon or claim as 'normative' is to describe it as value-dependent. A description of a phenomenon or claim as 'normative' in the third sense does not entail such value-dependency, though it leaves open the possibility that value depends upon the phenomenon or upon the truth of the claim. It is argued that while survival needs (or claims about them) may well be normative in this third sense, they are normative in neither of the first two. Thus, the idea of absolute need is not inherently normative in either of the first two senses. PMID:23586876

  14. 2D coherent charge transport in highly ordered conducting polymers doped by solid state diffusion

    NASA Astrophysics Data System (ADS)

    Kang, Keehoon; Watanabe, Shun; Broch, Katharina; Sepe, Alessandro; Brown, Adam; Nasrallah, Iyad; Nikolka, Mark; Fei, Zhuping; Heeney, Martin; Matsumoto, Daisuke; Marumoto, Kazuhiro; Tanaka, Hisaaki; Kuroda, Shin-Ichi; Sirringhaus, Henning

    2016-08-01

    Doping is one of the most important methods to control charge carrier concentration in semiconductors. Ideally, the introduction of dopants should not perturb the ordered microstructure of the semiconducting host. In some systems, such as modulation-doped inorganic semiconductors or molecular charge transfer crystals, this can be achieved by spatially separating the dopants from the charge transport pathways. However, in conducting polymers, dopants tend to be randomly distributed within the conjugated polymer, and as a result the transport properties are strongly affected by the resulting structural and electronic disorder. Here, we show that in the highly ordered lamellar microstructure of a regioregular thiophene-based conjugated polymer, a small-molecule p-type dopant can be incorporated by solid state diffusion into the layers of solubilizing side chains without disrupting the conjugated layers. In contrast to more disordered systems, this allows us to observe coherent, free-electron-like charge transport properties, including a nearly ideal Hall effect in a wide temperature range, a positive magnetoconductance due to weak localization and the Pauli paramagnetic spin susceptibility.

  15. Fragile charge order in the nonsuperconducting ground state of the underdoped high-temperature superconductors

    PubMed Central

    Tan, B. S.; Harrison, N.; Zhu, Z.; Balakirev, F.; Ramshaw, B. J.; Srivastava, A.; Sabok-Sayr, S. A.; Dabrowski, B.; Lonzarich, G. G.; Sebastian, Suchitra E.

    2015-01-01

    The normal state in the hole underdoped copper oxide superconductors has proven to be a source of mystery for decades. The measurement of a small Fermi surface by quantum oscillations on suppression of superconductivity by high applied magnetic fields, together with complementary spectroscopic measurements in the hole underdoped copper oxide superconductors, point to a nodal electron pocket from charge order in YBa2Cu3O6+δ. Here, we report quantum oscillation measurements in the closely related stoichiometric material YBa2Cu4O8, which reveals similar Fermi surface properties to YBa2Cu3O6+δ, despite the nonobservation of charge order signatures in the same spectroscopic techniques, such as X-ray diffraction, that revealed signatures of charge order in YBa2Cu3O6+δ. Fermi surface reconstruction in YBa2Cu4O8 is suggested to occur from magnetic field enhancement of charge order that is rendered fragile in zero magnetic fields because of its potential unconventional nature and/or its occurrence as a subsidiary to more robust underlying electronic correlations. PMID:26199413

  16. Fragile charge order in the nonsuperconducting ground state of the underdoped high-temperature superconductors.

    PubMed

    Tan, B S; Harrison, N; Zhu, Z; Balakirev, F; Ramshaw, B J; Srivastava, A; Sabok-Sayr, S A; Sabok, S A; Dabrowski, B; Lonzarich, G G; Sebastian, Suchitra E

    2015-08-01

    The normal state in the hole underdoped copper oxide superconductors has proven to be a source of mystery for decades. The measurement of a small Fermi surface by quantum oscillations on suppression of superconductivity by high applied magnetic fields, together with complementary spectroscopic measurements in the hole underdoped copper oxide superconductors, point to a nodal electron pocket from charge order in YBa2Cu3(6+δ). Here, we report quantum oscillation measurements in the closely related stoichiometric material YBa2Cu4O8, which reveals similar Fermi surface properties to YBa2Cu3(6+δ), despite the nonobservation of charge order signatures in the same spectroscopic techniques, such as X-ray diffraction, that revealed signatures of charge order in YBa2Cu3(6+δ). Fermi surface reconstruction in YBa2Cu4O8 is suggested to occur from magnetic field enhancement of charge order that is rendered fragile in zero magnetic fields because of its potential unconventional nature and/or its occurrence as a subsidiary to more robust underlying electronic correlations. PMID:26199413

  17. Charge transport model in solid-state avalanche amorphous selenium and defect suppression design

    NASA Astrophysics Data System (ADS)

    Scheuermann, James R.; Miranda, Yesenia; Liu, Hongyu; Zhao, Wei

    2016-01-01

    Avalanche amorphous selenium (a-Se) in a layer of High Gain Avalanche Rushing Photoconductor (HARP) is being investigated for its use in large area medical imagers. Avalanche multiplication of photogenerated charge requires electric fields greater than 70 V μm-1. For a-Se to withstand this high electric field, blocking layers are used to prevent the injection of charge carriers from the electrodes. Blocking layers must have a high injection barrier and deep trapping states to reduce the electric field at the interface. In the presence of a defect in the blocking layer, a distributed resistive layer (DRL) must be included into the structure to build up space charge and reduce the electric field in a-Se and the defect. A numerical charge transport model has been developed to optimize the properties of blocking layers used in various HARP structures. The model shows the incorporation of a DRL functionality into the p-layer can reduce dark current at a point defect by two orders of magnitude by reducing the field in a-Se to the avalanche threshold. Hole mobility in a DRL of ˜10-8 cm2 V-1 s-1 at 100 V μm-1 as demonstrated by the model can be achieved experimentally by varying the hole mobility of p-type organic or inorganic semiconductors through doping, e.g., using Poly(9-vinylcarbozole) doped with 1%-3% (by weight) of poly(3-hexylthiopene).

  18. Adaptive Kalman filter based state of charge estimation algorithm for lithium-ion battery

    NASA Astrophysics Data System (ADS)

    Zheng, Hong; Liu, Xu; Wei, Min

    2015-09-01

    In order to improve the accuracy of the battery state of charge (SOC) estimation, in this paper we take a lithium-ion battery as an example to study the adaptive Kalman filter based SOC estimation algorithm. Firstly, the second-order battery system model is introduced. Meanwhile, the temperature and charge rate are introduced into the model. Then, the temperature and the charge rate are adopted to estimate the battery SOC, with the help of the parameters of an adaptive Kalman filter based estimation algorithm model. Afterwards, it is verified by the numerical simulation that in the ideal case, the accuracy of SOC estimation can be enhanced by adding two elements, namely, the temperature and charge rate. Finally, the actual road conditions are simulated with ADVISOR, and the simulation results show that the proposed method improves the accuracy of battery SOC estimation under actual road conditions. Thus, its application scope in engineering is greatly expanded. Project supported by the National Natural Science Foundation of China (Grant Nos. 61004048 and 61201010).

  19. Stable bound states of like charges on top of graphene in magnetic field

    NASA Astrophysics Data System (ADS)

    Slizovskiy, Sergey

    We show theoretically that in the external magnetic field like charges on top of graphene monolayer may be mutually attracted to form thermodinamically stable macro-molecules. For this to happen graphene needs to be in Quantum Hall plateau state with local chemical potential being between the Landau levels. Graphene electron(s) gets localized in the middle between charges and provides overscreening of Coulomb repulsion between the charges. The size of the resulting macro-molecules is of the order of the magnetic length (~ 10 nm for magnetic field 10 T). The possible stable macro-molecules that unit charges can form on graphene in magnetic field are classified. The binding survives significant temperatures, exceeding mobility barriers for many ionically bond impurities. The influence of possible lattice-scale effects of valley-mixing are discussed. Tuning the doping of graphene or the magnetic field, the binding of impurities can be turned on and off and the macro-molecule size may be tuned. This opens the perspective to nanoscopic manipulation of ions on graphene by using magnetic field and gating. Acknowledge EPSRC EP/l02669X/1 and EP/H049797/1 and RSF Grant 14-22-00281.

  20. Influence of the charge state of recombination centers on the photosensitivity of semiconductors

    SciTech Connect

    Karakis, Yu.N.; Vasilevskii, D.L.; Moreno, K.; Serdyuk, V.V.

    1988-12-01

    The introduction of recombination centers with significantly different capture cross sections for the majority (S/sub n/) and minority (S/sub p/) charge carriers (W/sub p//S/sub n/ > 10/sup 4/) into photosensitive semiconductors such as CdSe, CdS, and some other compounds significantly increases the lifetime of the nonequilibrium electrons /tau//sub n/ in a number of cases. The authors made an attempt to precisely describe the variation of the lifetime of the majority current carriers in a semiconductor with enhanced photosensitivity. The results of the calculations show that the variation of the lifetime of the majority charge carriers in a sample with enhanced photosensitivity depends on the charge state of the centers which play the role of the rapid-recombination centers. When these centers are positively charged, /tau//sub n/ increases by /approx/2 orders of magnitude. If the electrons are captured in neutral levels, the lifetime /tau//sub n/ varies to a considerably greater degree. In both cases, an increase in the photoexcitation intensity results, as expected, in a decrease in /tau//sub n/ in a crystal with increased photosensitivity.

  1. Charge transfer excitations from excited state Hartree-Fock subsequent minimization scheme

    SciTech Connect

    Theophilou, Iris; Tassi, M.; Thanos, S.

    2014-04-28

    Photoinduced charge-transfer processes play a key role for novel photovoltaic phenomena and devices. Thus, the development of ab initio methods that allow for an accurate and computationally inexpensive treatment of charge-transfer excitations is a topic that nowadays attracts a lot of scientific attention. In this paper we extend an approach recently introduced for the description of single and double excitations [M. Tassi, I. Theophilou, and S. Thanos, Int. J. Quantum Chem. 113, 690 (2013); M. Tassi, I. Theophilou, and S. Thanos, J. Chem. Phys. 138, 124107 (2013)] to allow for the description of intermolecular charge-transfer excitations. We describe an excitation where an electron is transferred from a donor system to an acceptor one, keeping the excited state orthogonal to the ground state and avoiding variational collapse. These conditions are achieved by decomposing the space spanned by the Hartree-Fock (HF) ground state orbitals into four subspaces: The subspace spanned by the occupied orbitals that are localized in the region of the donor molecule, the corresponding for the acceptor ones and two more subspaces containing the virtual orbitals that are localized in the neighborhood of the donor and the acceptor, respectively. Next, we create a Slater determinant with a hole in the subspace of occupied orbitals of the donor and a particle in the virtual subspace of the acceptor. Subsequently we optimize both the hole and the particle by minimizing the HF energy functional in the corresponding subspaces. Finally, we test our approach by calculating the lowest charge-transfer excitation energies for a set of tetracyanoethylene-hydrocarbon complexes that have been used earlier as a test set for such kind of excitations.

  2. Charge transfer excitations from excited state Hartree-Fock subsequent minimization scheme.

    PubMed

    Theophilou, Iris; Tassi, M; Thanos, S

    2014-04-28

    Photoinduced charge-transfer processes play a key role for novel photovoltaic phenomena and devices. Thus, the development of ab initio methods that allow for an accurate and computationally inexpensive treatment of charge-transfer excitations is a topic that nowadays attracts a lot of scientific attention. In this paper we extend an approach recently introduced for the description of single and double excitations [M. Tassi, I. Theophilou, and S. Thanos, Int. J. Quantum Chem. 113, 690 (2013); M. Tassi, I. Theophilou, and S. Thanos, J. Chem. Phys. 138, 124107 (2013)] to allow for the description of intermolecular charge-transfer excitations. We describe an excitation where an electron is transferred from a donor system to an acceptor one, keeping the excited state orthogonal to the ground state and avoiding variational collapse. These conditions are achieved by decomposing the space spanned by the Hartree-Fock (HF) ground state orbitals into four subspaces: The subspace spanned by the occupied orbitals that are localized in the region of the donor molecule, the corresponding for the acceptor ones and two more subspaces containing the virtual orbitals that are localized in the neighborhood of the donor and the acceptor, respectively. Next, we create a Slater determinant with a hole in the subspace of occupied orbitals of the donor and a particle in the virtual subspace of the acceptor. Subsequently we optimize both the hole and the particle by minimizing the HF energy functional in the corresponding subspaces. Finally, we test our approach by calculating the lowest charge-transfer excitation energies for a set of tetracyanoethylene-hydrocarbon complexes that have been used earlier as a test set for such kind of excitations. PMID:24784248

  3. Calculation of Ion Charge State Distributions After Inner-Shell Ionization in Xe Atom

    SciTech Connect

    Mohammedein, Adel M.; Ghoneim, Adel A.; Kandil, Kandil M.; Kadad, Ibrahim M.

    2010-01-05

    The vacancy cascades following initial inner-shell vacancies in single and multi-ionized atoms often lead to highly charged residual ions. The inner-shell vacancy produced by ionization processes may decay by either a radiative or non-radiative transition. In addition to the vacancy filling processes, there is an electron shake off process due to the change of core potential of the atom. In the calculation of vacancy cascades, the radiative (x-ray) and non-radiative (Auger and Coster-Kronig) branching ratios give valuable information on the de-excitation dynamics of an atom with inner-shell vacancy. The production of multi-charged ions yield by the Auger cascades following inner shell ionization of an atom has been studied both experimentally and theoretically. Multi-charged Xe ions following de-excitation of K-, L{sub 1}-, L{sub 2,3}-, M{sub 1}-, M{sub 2,3}- and M{sub 4,5} subshell vacancies are calculated using Monte-Carlo algorithm to simulate the vacancy cascade development. Fluorescence yield (radiative) and Auger, Coster- Kronig yield (non- radiative) are evaluated. The decay of K hole state through radiative transitions is found to be more probable than non-radiative transitions in the first step of de-excitation. On the other hand, the decay of L, M vacancies through non-radiative transitions are more probable. The K shell ionization in Xe atom mainly yields Xe{sup 7+}, Xe{sup 8+}, Xe{sup 9+} and Xe{sup 10+} ions, and the charged X{sup 8+} ions are the highest. The main product from the L{sub 1}- shell ionization is found to be Xe{sup 8+}, Xe{sup 9+} ions, while the charged Xe{sup 8+} ions predominate at L{sub 2,3} hole states. The charged Xe{sup 6+}, Xe{sup 7+} and Xe{sup 8+} ions mainly yield from 3s{sub 1/2} and 3p{sub 1/2,3/2} ionization, while Xe in 3d{sub 3/2,5/2} hole states mainly turns into Xe{sup 4+} and Xe{sup 5+} ions. The present results are found to agree well with the experimental data.

  4. Charge transfer complex states in diketopyrrolopyrrole polymers and fullerene blends: Implications for organic solar cell efficiency

    NASA Astrophysics Data System (ADS)

    Moghe, D.; Yu, P.; Kanimozhi, C.; Patil, S.; Guha, S.

    2011-12-01

    The spectral photocurrent characteristics of two donor-acceptor diketopyrrolopyrrole (DPP)-based copolymers (PDPP-BBT and TDPP-BBT) blended with a fullerene derivative [6,6]-phenyl C61-butyric acid methyl ester (PCBM) were studied using Fourier-transform photocurrent spectroscopy (FTPS) and monochromatic photocurrent (PC) method. PDPP-BBT:PCBM shows the onset of the lowest charge transfer complex (CTC) state at 1.42 eV, whereas TDPP-BBT:PCBM shows no evidence of the formation of a midgap CTC state. The FTPS and PC spectra of P3HT:PCBM are also compared. The larger singlet state energy difference of TDPP-BBT and PCBM compared to PDPP-BBT/P3HT and PCBM obliterates the formation of a midgap CTC state resulting in an enhanced photovoltaic efficiency over PDPP-BBT:PCBM.

  5. Magnetic field dependence of a charge-frustrated state in a triangular triple quantum dot

    NASA Astrophysics Data System (ADS)

    Seo, M.; Chung, Y.

    2013-11-01

    We studied the magnetic field dependence of a charge-frustrated state formed in a triangular triple quantum dot. Stability diagrams at various magnetic fields were measured by using two-terminal and three-terminal conductance measurement schemes. We found that the frustrated state broke down at an external magnetic field of around 0.1 T. This result is due to the confinement energy shifts in quantum dots under external magnetic fields. A similar breakdown of the frustrated state was observed when the confinement energy of a quantum dot was intentionally shifted by the plunger gate of the dot, which confirm the reason for the breakdown of the frustrated state under on applied magnetic field. Our measured stability diagrams differed depending on the measurement schemes, which could not be explained by the capacitive interaction model based on an independent particle picture. We believe that the discrepancy is related to the closed electron and hole trajectories inside a triple quantum dot.

  6. Effect of surface charge state on the surface stress of a microcantilever.

    PubMed

    Zhang, Neng-Hui; Wu, Jun-Zheng; Meng, Wei-Lie; Tan, Zou-Qing

    2016-04-01

    The surface charge state at a liquid-solid interface is important to the variations in the physical/chemical properties of adsorbate film such as surface stress and the ensuing tip deflection of the microcantilever. The well-known Stoney's equation, derived more than 100 years ago, conceals the film electrical properties with the replacement of substrate deformation induced by adsorptions of particles. This implicit expression provides a shortcut to circumvent the difficulty in identifying some film properties, however, it limits the capacity to ascertain the relation between surface stress variation and the surface charge state. In this paper, we present an analytical expression to quantify the cantilever deflection/surface stress and the film potential difference by combining the piezoelectric theory and Poisson-Boltzmann equation for electrolyte solution. This updated version indicates that the two linear correlations between surface stress and surface charge density or the bias voltage are not contradictory, but two aspects of one thing under different conditions. Based on Parsegian's mesoscopic interaction potential, a multiscale prediction for the piezoelectric coefficient of double-stranded DNA (dsDNA) film is done, and the results show that the distinctive size effect with variations in salt concentration and nucleotide number provides us with an opportunity to obtain a more sensitive potential-actuated microcantilever sensor by careful control of packing conditions. PMID:26916422

  7. Field-induced conductance switching by charge-state alternation in organometallic single-molecule junctions.

    PubMed

    Schwarz, Florian; Kastlunger, Georg; Lissel, Franziska; Egler-Lucas, Carolina; Semenov, Sergey N; Venkatesan, Koushik; Berke, Heinz; Stadler, Robert; Lörtscher, Emanuel

    2016-02-01

    Charge transport through single molecules can be influenced by the charge and spin states of redox-active metal centres placed in the transport pathway. These intrinsic properties are usually manipulated by varying the molecule's electrochemical and magnetic environment, a procedure that requires complex setups with multiple terminals. Here we show that oxidation and reduction of organometallic compounds containing either Fe, Ru or Mo centres can solely be triggered by the electric field applied to a two-terminal molecular junction. Whereas all compounds exhibit bias-dependent hysteresis, the Mo-containing compound additionally shows an abrupt voltage-induced conductance switching, yielding high-to-low current ratios exceeding 1,000 at bias voltages of less than 1.0 V. Density functional theory calculations identify a localized, redox-active molecular orbital that is weakly coupled to the electrodes and closely aligned with the Fermi energy of the leads because of the spin-polarized ground state unique to the Mo centre. This situation provides an additional slow and incoherent hopping channel for transport, triggering a transient charging effect in the entire molecule with a strong hysteresis and large high-to-low current ratios. PMID:26571004

  8. Field-induced conductance switching by charge-state alternation in organometallic single-molecule junctions

    NASA Astrophysics Data System (ADS)

    Schwarz, Florian; Kastlunger, Georg; Lissel, Franziska; Egler-Lucas, Carolina; Semenov, Sergey N.; Venkatesan, Koushik; Berke, Heinz; Stadler, Robert; Lörtscher, Emanuel

    2016-02-01

    Charge transport through single molecules can be influenced by the charge and spin states of redox-active metal centres placed in the transport pathway. These intrinsic properties are usually manipulated by varying the molecule's electrochemical and magnetic environment, a procedure that requires complex setups with multiple terminals. Here we show that oxidation and reduction of organometallic compounds containing either Fe, Ru or Mo centres can solely be triggered by the electric field applied to a two-terminal molecular junction. Whereas all compounds exhibit bias-dependent hysteresis, the Mo-containing compound additionally shows an abrupt voltage-induced conductance switching, yielding high-to-low current ratios exceeding 1,000 at bias voltages of less than 1.0 V. Density functional theory calculations identify a localized, redox-active molecular orbital that is weakly coupled to the electrodes and closely aligned with the Fermi energy of the leads because of the spin-polarized ground state unique to the Mo centre. This situation provides an additional slow and incoherent hopping channel for transport, triggering a transient charging effect in the entire molecule with a strong hysteresis and large high-to-low current ratios.

  9. Low-energy/high-charge-state ions in the polar ionosphere observed by AKEBONO/SMS

    NASA Astrophysics Data System (ADS)

    Sagawa, E.; Watanabe, Shigeaki; Watanabe, Shigeto

    The suprathermal ion mass spectrometer (SMS) onboard the AKEBONO satellite has occasionally observed a broad mass peak in the ion mass spectrum at amu/ q ˜ 2.7. SMS is capable of measuring a wide range of ion mass (1-64 amu/ q) at low energy ( E < ˜100 eV) with good mass resolution (Δ M/ M ˜ 0.1). The events were observed at about 1 Re altitude, and mostly at the polar cusp region as identified by the on-board low-energy particle (LEP) instrument. The broad mass peak is consistent with high-charge state ions commonly seen in the solar wind such as C 6+, O 7+, and O 6+. Although it is difficult to identify the charge state of these ions definitively using SMS, which is a mass-per-charge analyzer, decomposition of the broad mass peak results in a reasonable ratio of O 7+/O 6+ to that in the solar wind. Statistical study shows that this type of events has been observed with an occurrence rate of about 10% near the dayside cusp region. Also, the occurrence rate is slightly higher when IMF Bz is positive, suggesting the entry of the solar wind plasma into the polar ionosphere with weaker acceleration during northward IMF compared with southward IMF.

  10. Assessing Attitudinal Congruency: A Case for Absolute (As Well As Relative) Indices. A Study of Schooling in the United States. Technical Report Series, No. 12.

    ERIC Educational Resources Information Center

    Sirotnik, Kenneth A.

    Two analytic models, each with different implications for data analysis, have been used in behavioral science research for assessing attitudinal congruency. The term relative congruence applies to the family of agreement indices which, although functions of the absolute index, are formulated relative to chance expectations. The term absolute…

  11. Calculations on charge state and energy loss of argon ions in partially and fully ionized carbon plasmas.

    PubMed

    Barriga-Carrasco, Manuel D; Casas, David; Morales, Roberto

    2016-03-01

    The energy loss of argon ions in a target depends on their velocity and charge density. At the energies studied in this work, it depends mostly on the free and bound electrons in the target. Here the random-phase approximation is used for analyzing free electrons at any degeneracy. For the plasma-bound electrons, an interpolation between approximations for low and high energies is applied. The Brandt-Kitagawa (BK) model is employed to depict the projectile charge space distribution, and the stripping criterion of Kreussler et al. is used to determine its equilibrium charge state Q(eq). This latter criterion implies that the equilibrium charge state depends slightly on the electron density and temperature of the plasma. On the other hand, the effective charge Q(eff) is obtained as the ratio between the energy loss of the argon ion and that of the proton for the same plasma conditions. This effective charge Q(eff) is larger than the equilibrium charge state Q(eq) due to the incorporation of the BK charge distribution. Though our charge-state estimations are not exactly the same as the experimental values, our energy loss agrees quite well with the experiments. It is noticed that the energy loss in plasmas is higher than that in the same cold target of about, ∼42-62.5% and increases with carbon plasma ionization. This confirms the well-known enhanced plasma stopping. It is also observed that only a small part of this energy loss enhancement is due to an increase of the argon charge state, namely only ∼2.2 and 5.1%, for the partially and the fully ionized plasma, respectively. The other contribution is connected with a better energy transfer to the free electrons at plasma state than to the bound electrons at solid state of about, ∼38.8-57.4%, where higher values correspond to a fully ionized carbon plasma. PMID:27078472

  12. Calculations on charge state and energy loss of argon ions in partially and fully ionized carbon plasmas

    NASA Astrophysics Data System (ADS)

    Barriga-Carrasco, Manuel D.; Casas, David; Morales, Roberto

    2016-03-01

    The energy loss of argon ions in a target depends on their velocity and charge density. At the energies studied in this work, it depends mostly on the free and bound electrons in the target. Here the random-phase approximation is used for analyzing free electrons at any degeneracy. For the plasma-bound electrons, an interpolation between approximations for low and high energies is applied. The Brandt-Kitagawa (BK) model is employed to depict the projectile charge space distribution, and the stripping criterion of Kreussler et al. is used to determine its equilibrium charge state Qeq. This latter criterion implies that the equilibrium charge state depends slightly on the electron density and temperature of the plasma. On the other hand, the effective charge Qeff is obtained as the ratio between the energy loss of the argon ion and that of the proton for the same plasma conditions. This effective charge Qeff is larger than the equilibrium charge state Qeq due to the incorporation of the BK charge distribution. Though our charge-state estimations are not exactly the same as the experimental values, our energy loss agrees quite well with the experiments. It is noticed that the energy loss in plasmas is higher than that in the same cold target of about, ˜42 -62.5 % and increases with carbon plasma ionization. This confirms the well-known enhanced plasma stopping. It is also observed that only a small part of this energy loss enhancement is due to an increase of the argon charge state, namely only ˜2.2 and 5.1 % , for the partially and the fully ionized plasma, respectively. The other contribution is connected with a better energy transfer to the free electrons at plasma state than to the bound electrons at solid state of about, ˜38.8 -57.4 % , where higher values correspond to a fully ionized carbon plasma.

  13. Charge state composition in coronal hole and CME related solar wind: Latitudinal variations observed by Ulysses and WIND

    NASA Technical Reports Server (NTRS)

    Galvin, A. B.; Gloeckler, G.

    1997-01-01

    Iron charge states in recurrent coronal hole-associated solar wind flows are obtained in the ecliptic by WIND/SMS, while measurements of iron and silicon from the polar coronal holes are available from Ulysses/SWICS. Ulysses/SWICS also provides ion composition of coronal mass ejection (CME)-related solar wind. Both coronal hole-associated and CME-related solar wind charge charges show heliographic latitudinal variations.

  14. Non-Abelian states in Fractional Quantum Hall effect in charge carrier hole systems

    NASA Astrophysics Data System (ADS)

    Simion, George; Lyanda-Geller, Yuli

    Quasiparticle excitations obeying non-Abelian statistics represent the key element of topological quantum computing. Crossing of levels and strong coupling between angular momentum and orbital motion, described by Luttinger Hamiltonian, make properties of charge carrier holes different from those of electrons. Peculiarities of hole spectrum in magnetic field provide an opportunity for controlling Landau level mixing in charge carier hole systems. In order to describe Fractional Quantum Hall effect for holes, we propose a method to map hole spectrum and wavefunctions using a spherical shell. We investigate the experimentally observed ν = 1 / 2 state in spherical geometry. Haldane pseudopotentials are computed and the effect of Landau level mixing is evaluated. Exact diagonalization of Coulomb interaction in systems with eight to fourteen holes is performed. We determine that the ground state superposition with Abelian 331 state is very small and the overlap with Moore-Read state is significant. The quasihole and quasielectron excitations are discussed. Research was supported by the U.S. Department of Energy, Office of Basic Energy Sciences, Division of Materials Sciences and Engineering under Award DE-SC0010544.

  15. The plasma environment, charge state, and currents of Saturn's C and D rings

    NASA Technical Reports Server (NTRS)

    Wilson, G. R.

    1991-01-01

    The charge state and associated currents of Saturn's C an D rings are studied by modeling the flow of ionospheric plasma from the mid- to low-latitude ionosphere to the vicinity of the rings. It is found that the plasma density near the C and D rings, at a given radial location, will experience a one to two order of magnitude diurnal variation. The surface charge density (SCD) of these rings can show significant radial and azimuthal variations due mainly to variation in the plasma density. The SCD also depends on structural features of the rings such as thickness and the nature of the particle size distribution. The associated azimuthal currents carried by these rings also show large diurnal variations resulting in field-aligned currents which close in the ionosphere. The resulting ionospheric electric field will probably not produce a significant amount of plasma convection in the topside ionosphere and inner plasmasphere.

  16. Evidence of the charge-density wave state in polypyrrole nanotubes

    NASA Astrophysics Data System (ADS)

    Sarma, Abhisakh; Sanyal, Milan K.; Littlewood, Peter B.

    2015-04-01

    We present a detailed investigation of the low-frequency dielectric and conductivity properties of conducting polymer nanowires. Our results, obtained by connecting ˜107 nanowires in parallel, show that these polypyrrole nanowires behave like conventional charge-density wave (CDW) materials, in their nonlinear and dynamic response, together with scaling of relaxation time and conductivity. The observed Arrhenius law for both these quantities gives a CDW gap of 3.5 meV in the regime of temperature (˜40 K) in which the CDW state survives. We find good agreement with a theory of weakly pinned CDW, screened by thermally excited carriers across the CDW gap. The identification of polymer nanowires as CDW provides us a model system to investigate charge ordering owing to electrostatic interaction, relevant to a variety of systems from dusty plasma to molecular biology.

  17. The partial state-of-charge cycle performance of lead-acid batteries

    NASA Astrophysics Data System (ADS)

    Takeuchi, Taisuke; Sawai, Ken; Tsuboi, Yuichi; Shiota, Masashi; Ishimoto, Shinji; Hirai, Nobumitsu; Osumi, Shigeharu

    Negative plate lugs of flooded lead-acid battery were corroded during partial state-of-charge (PSoC) pattern cycle life tests simulated from stop and go vehicle driving. Potential step was applied to Pb-Ca-Sn alloy electrode at various potential and time regimes, and the electrode surface was observed by in situ electrochemical atomic force microscope (EC-AFM) to investigate the corrosion mechanisms during the potential step cycles. It was found out that the severe corrosion occurs when the oxidation of Pb to PbSO 4 and partial reduction of passive layer of PbSO 4 take turns many times. It was also found out that the periodic full charge, the optimization of the alloy composition, addition of the material that may make the reaction mechanism change to electrolyte were effective to suppress the corrosion rate.

  18. Radiative charge-transfer lifetime of the excited state of (NaCa){sup +}

    SciTech Connect

    Makarov, Oleg P.; Cote, R.; Michels, H.; Smith, W.W.

    2003-04-01

    New experiments were proposed recently to investigate the regime of cold atomic and molecular ion-atom collision processes in a special hybrid neutral-atom-ion trap under high-vacuum conditions. We study the collisional cooling of laser precooled Ca{sup +} ions by ultracold Na atoms. Modeling this process requires knowledge of the radiative lifetime of the excited singlet A {sup 1}{sigma}{sup +} state of the (NaCa){sup +} molecular system. We calculate the rate coefficient for radiative charge transfer using a semiclassical approach. The dipole radial matrix elements between the ground and the excited states, and the potential curves were calculated using complete active space self-consistent field and Moeller-Plesset second-order perturbation theory with an extended Gaussian basis, 6-311+G (3df). The semiclassical charge-transfer rate coefficient was averaged over a thermal Maxwellian distribution. In addition, we also present elastic collision cross sections and the spin-exchange cross section. The rate coefficient for charge transfer was found to be 2.3x10{sup -16} cm{sup 3}/sec, while those for the elastic and spin-exchange cross sections were found to be several orders of magnitude higher (1.1x10{sup -8} cm{sup 3}/sec and 2.3x10{sup -9} cm{sup 3}/sec, respectively). This confirms our assumption that the milli-Kelvin regime of collisional cooling of calcium ions by sodium atoms is favorable with the respect to low loss of calcium ions due to the charge transfer.

  19. Excited state and charge dynamics of hybrid organic/inorganic heterojunctions. II. Experiment

    NASA Astrophysics Data System (ADS)

    Panda, Anurag; Renshaw, C. Kyle; Oskooi, Ardavan; Lee, Kyusang; Forrest, Stephen R.

    2014-07-01

    In our companion paper (Paper I) [C. K. Renshaw and S. R. Forrest, Phys. Rev. B 90, 045302 (2014), 10.1103/PhysRevB.90.045302], we developed a model for charge transport and photogeneration at hybrid organic/inorganic semiconductor heterojunctions (OI-HJs). Here we apply the model to two planar bilayer hybrid photovoltaic devices: the first using the wide-band gap n-TiO2 in combination with the hole transporting tetraphenyl-dibenzoperiflanthene (DBP), and the second based on the moderate-band gap n-InP and the hole transporting pentacene (PEN). We measure the external quantum efficiency (EQE) and current density vs voltage (J-V) characteristics of both devices as functions of temperature. The EQE spectra for both TiO2/DBP and InP/PEN provide convincing evidence that Frenkel states generated in the organic form hybrid charge transfer excitons (HCTEs) at the OI-HJ that are subsequently dissociated into free charges, and then collected at the opposing electrodes. The dissociation efficiency is found to be strongly influenced by the presence of surface states, particularly in the InP/PEN device. We further develop the J-V model from Paper I to include an analytical expression for space-charge effects in the organic at high currents. Model fits to the J-V data suggest that the temperature-dependent hole mobilities in both DBP and PEN result in increasing space-charge effects at low temperatures. Furthermore, we find that the J-V characteristics of the TiO2/DBP device both in the dark and under illumination are governed by interface recombination. In contrast, the dark current in the InP/PEN device is governed by injection over the OI-HJ barrier, whereas the photocurrent is dominated by interface recombination. This work elucidates the role of the HCTE state in photogeneration, and the applicability of our model to a range of important optoelectronic devices.

  20. Is dipole moment a valid descriptor of excited state's charge-transfer character?

    PubMed

    Petelenz, Piotr; Pac, Barbara

    2013-11-20

    In the ongoing discussion on excited states of the pentacene crystal, dipole moment values have been recently invoked to gauge the CT admixture to excited states of Frenkel parentage in a model cluster. In the present paper, a simple dimer model is used to show that, in general, the dipole moment is not a valid measure of the CT contribution. This finding eliminates some apparent disagreement between the computational results published by different research groups. The implications of our results and other related aspects of cluster-type quantum chemistry calculations are discussed in the context of the standing literature dispute concerning the mechanism of singlet fission in the pentacene crystal, notably the role of charge transfer contributions vs the involvement of an excimer-like doubly excited intermediate (D state). PMID:24138489

  1. Photoionization study of quasibound states of doubly charged molecular nitrogen ions

    NASA Astrophysics Data System (ADS)

    Hellner, L.; Besnard, M. J.; Dujardin, G.; Malinovich, Y.

    1988-01-01

    Doubly charged N 22+ ions were produced by double photoionization of neutral nitrogen molecules with the synchrotron radiation from ACO as a photon source of variable energy in the 40-70 eV range. From the double photoionization spectrum the threshold energy of the stable X 1Σ g+ state was found at 43.1 ± 0.1 eV. The D 1Σ g+ → X 1Σ g+ emission observed by using a photoion-photon of fluorescence coincidence (PIFCO) experiment. The onset energy of this emitting D 1Σ u+ state at 50.5 eV, was deduced from the variation of the fluorescence efficiency as a function of the excitation photon energy. The lifetime of this emitting state was measured to be τ = 8 ± 3 ns.

  2. Quantum Lattice Fluctuations in the Charge Density Wave State beyond the Adiabatic Approximation

    NASA Astrophysics Data System (ADS)

    Shida, Keisuke; Watanabe, Yuko; Gomi, Hiroki; Takahashi, Akira; Tomita, Norikazu

    2015-12-01

    We have developed a tractable numerical method in which large-amplitude quantum lattice fluctuations can be described beyond the adiabatic approximation using the coherent state representation of phonons. A many-body wave function is constructed by the superposition of direct products of non-orthogonal Slater determinants for electrons and coherent states of phonons. Both orbitals in all the Slater determinants and the amplitudes of all the coherent states are simultaneously optimized. We apply the method to the one-dimensional Su-Schrieffer-Heeger model with the on-site and nearest-neighbor-site Coulomb interactions. It is shown the lattice fluctuations in doped charge density wave (CDW) systems are described by the translational and vibrational motion of lattice solitons. Such lattice solitons induce bond alternation in the doped CDW system while the lattice becomes equidistant in the half-filled CDW system.

  3. Charge and magnetic states of rutile TiO2 doped with Cr ions.

    PubMed

    Kim, Rokyeon; Cho, Suyeon; Park, Won-Goo; Cho, Deok-Yong; Oh, Se-Jung; Saint-Martin, Romuald; Berthet, Patrick; Park, Je-Geun; Yu, Jaejun

    2014-04-01

    We observe that the electronic and magnetic properties of Cr-doped rutile TiO2 single crystals are highly dependent on growth conditions. The ferromagnetic component of magnetic susceptibility is observed to be enhanced for samples grown under oxygen-rich conditions. To understand the charge state of Cr dopants and their role in response to an external magnetic field, we carry out density functional theory calculations for Cr-doped rutile TiO2. Using the results of formation energy calculations in the presence of oxygen vacancies and Cr atom substitution at the Ti sites, we demonstrate that the Cr3+ state is a source of Curie-Weiss-type magnetic response, whereas the Cr4+ defect states contribute to the ferromagnetic component. We also provide the electronic structures of various defect configurations and attempt to explain the optical and electronic properties of the Cr-doped system. PMID:24651728

  4. Identifying the magnetoconductance responses by the induced charge transfer complex states in pentacene-based diodes

    NASA Astrophysics Data System (ADS)

    Huang, Wei-Shun; Lee, Tsung-Hsun; Guo, Tzung-Fang; Huang, J. C. A.; Wen, Ten-Chin

    2012-07-01

    We investigate the magnetoconductance (MC) responses in photocurrent, unipolar injection, and bipolar injection regimes in pentacene-based diodes. Both photocurrent and bipolar injection contributed MC responses show large difference in MC line shape, which are attributed to triplet-polaron interaction modulated by the magnetic field dependent singlet fission and the intersystem crossing of the polaron pair, respectively. By blending 2,3,5,6-tetrafluoro-7,7,8,8-tetracyanoquinodimethane into pentacene, all the MC responses are suppressed but the MC response at unipolar injection regime is enhanced, which is attributed to the induced charge transfer complex states (CT complex states). This work identify the MC responses between single carrier contributed MC and exciton related MC by the induced CT complex states.

  5. Generation of excited coherent states for a charged particle in a uniform magnetic field

    SciTech Connect

    Mojaveri, B.; Dehghani, A. E-mail: alireza.dehghani@gmail.com

    2015-04-15

    We introduce excited coherent states, |β,α;nгЂ‰≔a{sup †n}|β,αгЂ‰, where n is an integer and states |β,αгЂ‰ denote the coherent states of a charged particle in a uniform magnetic field. States |β,αгЂ‰ minimize the Schrödinger-Robertson uncertainty relation while having the nonclassical properties. It has been shown that the resolution of identity condition is realized with respect to an appropriate measure on the complex plane. Some of the nonclassical features such as sub-Poissonian statistics and quadrature squeezing of these states are investigated. Our results are compared with similar Agarwal’s type photon added coherent states (PACSs) and it is shown that, while photon-counting statistics of |β,α,nгЂ‰ are the same as PACSs, their squeezing properties are different. It is also shown that for large values of |β|, while they are squeezed, they minimize the uncertainty condition. Additionally, it has been demonstrated that by changing the magnitude of the external magnetic field, B{sub ext}, the squeezing effect is transferred from one component to another. Finally, a new scheme is proposed to generate states |β,α;nгЂ‰ in cavities. .

  6. Combined State of Charge and State of Health estimation over lithium-ion battery cell cycle lifespan for electric vehicles

    NASA Astrophysics Data System (ADS)

    Zou, Yuan; Hu, Xiaosong; Ma, Hongmin; Li, Shengbo Eben

    2015-01-01

    A combined SOC (State Of Charge) and SOH (State Of Health) estimation method over the lifespan of a lithium-ion battery is proposed. First, the SOC dependency of the nominal parameters of a first-order RC (resistor-capacitor) model is determined, and the performance degradation of the nominal model over the battery lifetime is quantified. Second, two Extended Kalman Filters with different time scales are used for combined SOC/SOH monitoring: the SOC is estimated in real-time, and the SOH (the capacity and internal ohmic resistance) is updated offline. The time scale of the SOH estimator is determined based on model accuracy deterioration. The SOC and SOH estimation results are demonstrated by using large amounts of testing data over the battery lifetime.

  7. Observation of excited state charge transfer with fs/ps-CARS

    SciTech Connect

    Blom, Alex Jason

    2009-01-01

    Excited state charge transfer processes are studied using the fs/ps-CARS probe technique. This probe allows for multiplexed detection of Raman active vibrational modes. Systems studied include Michler's Ketone, Coumarin 120, 4-dimethylamino-4'-nitrostilbene, and several others. The vibrational spectrum of the para di-substituted benzophenone Michler's Ketone in the first excited singlet state is studied for the first time. It is found that there are several vibrational modes indicative of structural changes of the excited molecule. A combined experimental and theoretical approach is used to study the simplest 7-amino-4-methylcoumarin, Coumarin 120. Vibrations observed in FTIR and spontaneous Raman spectra are assigned using density functional calculations and a continuum solvation model is used to predict how observed modes are affected upon inclusion of a solvent. The low frequency modes of the excited state charge transfer species 4-dimethylamino-4{prime}-nitrostilbene are studied in acetonitrile. Results are compared to previous work on this molecule in the fingerprint region. Finally, several partially completed projects and their implications are discussed. These include the two photon absorption of Coumarin 120, nanoconfinement in cyclodextrin cavities and sensitization of titania nanoparticles.

  8. Future prospects for ECR plasma generators with improved charge state distributions

    SciTech Connect

    Alton, G.D.; Liu, Y.

    1997-06-01

    The growing number and variety of fundamental, applied, and industrial uses for high intensity, high charge state ion beams continues to be the driving force behind efforts to develop Electron Cyclotron Resonance (ECR) ion sources with superior performance characteristics. Incumbent with the advent of sub-micron electronic devices and their fabrication has been the demand for improved process control and optimization. These demands have led to the development of methods for cleaning, chemical etching, and deposition of thin films based on the use of plasma devices including ECR sources. Despite the steady advance in the technology, ECR plasma heating has not yet reached its full potential in terms of charge state and intensity within a particular charge state, in part, because of the narrow band width, single-frequency microwave radiation commonly used to heat the plasma electrons. This heating technique, coupled with conventional minimum-B configuration magnetic fields used for confining the electrons, resulting in the formation of the thin, ECR surfaces within the plasma volumes of these sources. This report identifies fundamentally important methods for enhancing the performances of ECR plasma generators by transforming the ECR zones from surfaces to volumes. Two methods are readily available for increasing the sizes of these zones. These techniques include: (1) a tailored magnetic field configuration in combination with single-frequency microwave radiation to create a large uniformly distributed ECR volume and; (2) the use of broadband-frequency domain techniques derived from standard TWT technology, to transform the resonant plasma surfaces of traditional ECR ion sources into resonant plasma volumes.

  9. Excess-electron and excess-hole states of charged alkali halide clusters

    NASA Astrophysics Data System (ADS)

    Honea, Eric C.; Homer, Margie L.; Whetten, R. L.

    1990-12-01

    Charged alkali halide clusters from a He-cooled laser vaporization source have been used to investigate two distinct cluster states corresponding to the excess-electron and excess-hole states of the crystal. The production method is UV-laser vaporization of an alkali metal rod into a halogen-containing He flow stream, resulting in variable cluster composition and cooling sufficient to stabilize weakly bound forms. Detection of charged clusters is accomplished without subsequent ionization by pulsed-field time-of-flight mass spectrometry of the skimmed cluster beam. Three types of positively charged sodium fluoride cluster are observed, each corresponding to a distinct physical situation: NanF+n-1 (purely ionic form), Nann+1F+n-1 (excess-electron form), and NanF+n (excess-hole form). The purely ionic clusters exhibit an abundance pattern similar to that observed in sputtering and fragmentation experiments and are explained by the stability of completed cubic microlattice structures. The excess-electron clusters, in contrast, exhibit very strong abundance maxima at n = 13 and 22, corresponding to the all-odd series (2n + 1 = jxkxl;j,k,l odd). Their high relative stability is explained by the ease of Na(0) loss except when the excess electron localizes in a lattice site to complete a cuboid structure. These may correspond to the internal F-center state predicted earlier. A localized electron model incorporating structural simulation results as account for the observed pattern. The excess-hole clusters, which had been proposed as intermediates in the ionization-induced fragmentation of neutral AHCs, exhibit a smaller variation in stability, indicating that the hole might not be well localized.

  10. Elemental and charge state composition of the fast solar wind observed with SMS instruments on WIND

    NASA Technical Reports Server (NTRS)

    Gloeckler, G.; Galvin, A. B.; Ipavich, F. M.; Hamilton, D. C.; Bochsler, P.; Geiss, J.; Fisk, L. A.; Wilken, B.

    1995-01-01

    The elemental composition and charge state distributions of heavy ions of the solar wind provide essential information about: (1) atom-ion separation processes in the solar atmosphere leading to the 'FIP effect' (the overabundance of low First Ionization potential (FIP) elements in the solar wind compared to the photosphere); and (2) coronal temperature profiles, as well as mechanisms which heat the corona and accelerate the solar wind. This information is required for solar wind acceleration models. The SWICS instrument on Ulysses measures for all solar wind flow conditions the relative abundance of about 8 elements and 20 charge states of the solar wind. Furthermore, the Ulysses high-latitude orbit provides an unprecedented look at the solar wind from the polar coronal holes near solar minimum conditions. The MASS instrument on the WIND spacecraft is a high-mass resolution solar wind ion mass spectrometer that will provide routinely not only the abundances and charge state of all elements easily measured with SWICS, but also of N, Mg, S. The MASS sensor was fully operational at the end of 1994 and has sampled the in-ecliptic solar wind composition in both the slow and the corotating fast streams. This unique combination of SWICS on Ulysses and MASS on WIND allows us to view for the first time the solar wind from two regions of the large coronal hole. Observations with SWICS in the coronal hole wind: (1) indicate that the FIP effect is small; and (2) allow us determine the altitude of the maximum in the electron temperature profile, and indicate a maximum temperature of approximately 1.5 MK. New results from the SMS instruments on Wind will be compared with results from SWICS on Ulysses.

  11. The Effect of Interfacial Geometry on Charge-Transfer States in the Phthalocyanine/Fullerene Organic Photovoltaic System.

    PubMed

    Lee, Myeong H; Geva, Eitan; Dunietz, Barry D

    2016-05-19

    The dependence of charge-transfer states on interfacial geometry at the phthalocyanine/fullerene organic photovoltaic system is investigated. The effect of deviations from the equilibrium geometry of the donor-donor-acceptor trimer on the energies of and electronic coupling between different types of interfacial electronic excited states is calculated from first-principles. Deviations from the equilibrium geometry are found to destabilize the donor-to-donor charge transfer states and to weaken their coupling to the photoexcited donor-localized states, thereby reducing their ability to serve as charge traps. At the same time, we find that the energies of donor-to-acceptor charge transfer states and their coupling to the donor-localized photoexcited states are either less sensitive to the interfacial geometry or become more favorable due to modifications relative to the equilibrium geometry, thereby enhancing their ability to serve as gateway states for charge separation. Through these findings, we eludicate how interfacial geometry modifications can play a key role in achieving charge separation in this widely studied organic photovoltaic system. PMID:26237431

  12. The absolute path command

    2012-05-11

    The ap command traveres all symlinks in a given file, directory, or executable name to identify the final absolute path. It can print just the final path, each intermediate link along with the symlink chan, and the permissions and ownership of each directory component in the final path. It has functionality similar to "which", except that it shows the final path instead of the first path. It is also similar to "pwd", but it canmore » provide the absolute path to a relative directory from the current working directory.« less

  13. The absolute path command

    SciTech Connect

    Moody, A.

    2012-05-11

    The ap command traveres all symlinks in a given file, directory, or executable name to identify the final absolute path. It can print just the final path, each intermediate link along with the symlink chan, and the permissions and ownership of each directory component in the final path. It has functionality similar to "which", except that it shows the final path instead of the first path. It is also similar to "pwd", but it can provide the absolute path to a relative directory from the current working directory.

  14. Direct Evidence for Projectile Charge-State Dependent Crater Formation Due to Fast Ions

    SciTech Connect

    Papaleo, R. M.; Silva, M. R.; Leal, R.; Grande, P. L.; Roth, M.; Schattat, B.; Schiwietz, G.

    2008-10-17

    We report on craters formed by individual 3 MeV/u Au{sup q{sub i}{sub n}{sub i}{sup +}} ions of selected incident charge states q{sub ini} penetrating thin layers of poly(methyl methacrylate). Holes and raised regions are formed around the region of the impact, with sizes that depend strongly and differently on q{sub ini}. Variation of q{sub ini}, of the film thickness and of the angle of incidence allows us to extract information about the depth of origin contributing to different crater features.

  15. Inducing Transient Charge State of a Single Water Cluster on Cu(111) Surface.

    PubMed

    Guo, Yang; Ding, Zijing; Sun, Lihuan; Li, Jianmei; Meng, Sheng; Lu, Xinghua

    2016-04-26

    The hydrated electron on solid surface is a crucial species to interfacial chemistry. We present a joint low-temperature scanning tunneling microscopy and density functional theory investigation to explore the existence of a transient hydrated electron state induced by injecting tunneling electrons into a single water nonamer cluster on Cu(111) surface. The directional diffusion of water cluster under the Coulomb repulsive potential has been observed as evidence for the emergence of the transient hydrated electron. A critical structure transformation in water cluster for the emergence of hydrated electron has been identified. A charging mechanism has been proposed based on density functional theory calculation and scanning tunneling microscope results. PMID:27007702

  16. Transient Velocity And Steady State Entropy Generation In A Microfluidic Couette Flow Containing Charged Nano Particles

    NASA Astrophysics Data System (ADS)

    Gorla, R. S. R.; Gireesha, B. J.

    2015-12-01

    An analysis has been provided to determine the transient velocity and steady state entropy generation in a microfluidic Couette flow influenced by electro-kinetic effect of charged nanoparticles. The equation for calculating the Couette flow velocity profile is derived for transient flow. The solutions for momentum and energy equations are used to get the exact solution for the dimensionless velocity ratio and dimensionless entropy generation number. The effects of the dimensionless entropy generation number, Bejan number, irreversibility ratio, entropy generation due to fluid friction and due to heat transfer on dimensionless time, relative channel height, Brinkman number, dimensionless temperature ratio, nanoparticle volume fraction are analyzed.

  17. Polymer space-charge-limited transistor as a solid-state vacuum tube triode

    NASA Astrophysics Data System (ADS)

    Chao, Yu-Chiang; Ku, Ming-Che; Tsai, Wu-Wei; Zan, Hsiao-Wen; Meng, Hsin-Fei; Tsai, Hung-Kuo; Horng, Sheng-Fu

    2010-11-01

    We report the construction of a polymer space-charge-limited transistor (SCLT), a solid-state version of vacuum tube triode. The SCLT achieves a high on/off ratio of 3×105 at a low operation voltage of 1.5 V by using high quality insulators both above and below the grid base electrode. Applying a greater bias to the base increases the barrier potential, and turns off the channel current, without introducing a large parasitic leakage current. Simulation result verifies the influence of base bias on channel potential distribution. The output current density is 1.7 mA/cm2 with current gain greater than 1000.

  18. Spin-charge separation of dark-state polaritons in a Rydberg medium

    NASA Astrophysics Data System (ADS)

    Shi, Xiao-Feng; Svetlichnyy, P.; Kennedy, T. A. B.

    2016-04-01

    The propagation of light fields through a quasi one-dimensional cold atomic gas, exciting atomic Rydberg levels of large principal quantum number under conditions of electromagnetically induced transparency, can lead to a stable two-mode Luttinger liquid system. Atomic van der Waals interactions induce a coupling of bosonic field modes that display both photonic and atomic character, the Rydberg dark-state polaritons (RDPs). It is shown that by tunable control of the van der Waals coupling, the RDP may decouple into independent ‘spin’ and ‘charge’ fields which propagate at different speeds, analogous to spin-charge separation of electrons in a one-dimensional metal.

  19. State of charge modeling of lithium-ion batteries using dual exponential functions

    NASA Astrophysics Data System (ADS)

    Kuo, Ting-Jung; Lee, Kung-Yen; Huang, Chien-Kang; Chen, Jau-Horng; Chiu, Wei-Li; Huang, Chih-Fang; Wu, Shuen-De

    2016-05-01

    A mathematical model is developed by fitting the discharging curve of LiFePO4 batteries and used to investigate the relationship between the state of charge and the closed-circuit voltage. The proposed mathematical model consists of dual exponential terms and a constant term which can fit the characteristics of dual equivalent RC circuits closely, representing a LiFePO4 battery. One exponential term presents the stable discharging behavior and the other one presents the unstable discharging behavior and the constant term presents the cut-off voltage.

  20. MOS Capacitance—Voltage Characteristics: IV. Trapping Capacitance from 3-Charge-State Impurities

    NASA Astrophysics Data System (ADS)

    Binbin, Jie; Chihtang, Sah

    2012-01-01

    Metal—Oxide—Semiconductor Capacitance—Voltage (MOSCV) characteristics containing giant carrier trapping capacitances from 3-charge-state or 2-energy-level impurities are presented for not-doped, n-doped, p-doped and compensated silicon containing the double-donor sulfur and iron, the double-acceptor zinc, and the amphoteric or one-donor and one-acceptor gold and silver impurities. These impurities provide giant trapping capacitances at trapping energies from 200 to 800 meV (50 to 200 THz and 6 to 1.5 μm), which suggest potential sub-millimeter, far-infrared and spin electronics applications.

  1. Iron charge states in the solar wind as measured by SMS on Wind

    NASA Technical Reports Server (NTRS)

    Galvin, A. B.; Cohen, C. M. S.; Ipavich, F. M.; Gloeckler, G.; Hamilton, D. C.; Chotoo, K.; Balsiger, H.; Sheldon, R.

    1995-01-01

    The Wind spacecraft was launched in November 1994. In the first half of 1995 it was in the interplanetary medium upstream of the Earth. The Solar Wind and Suprathermal Ion Composition Experiment (SMS) on Wind consists of three sensors, the Solar Wind Ion Composition Spectrometer (SWICS), the Suprathermal Ion Composition Spectrometer (STICS), and the high mass resolution spectrometer (MASS). All three instruments utilize electrostatic deflection combined with time-of-flight measurement. The data from these three sensors allows the determination of the ionic composition of the solar wind in a variety of solar wind conditions over a large energy/charge range (0.5 to 230 keV/e). We have examined the Wind database for time periods conducive to observing solar wind iron. With the high mass resolution of the MASS spectrometer (M/Delta-M greater than 100) iron is easily identified while the electrostatic deflection provides information concerning the mass/charge distribution. We present here the relative abundance of iron charge states in the solar wind near 1 AU.

  2. Organic heterojunctions: Contact-induced molecular reorientation, interface states, and charge re-distribution

    NASA Astrophysics Data System (ADS)

    Opitz, Andreas; Wilke, Andreas; Amsalem, Patrick; Oehzelt, Martin; Blum, Ralf-Peter; Rabe, Jürgen P.; Mizokuro, Toshiko; Hörmann, Ulrich; Hansson, Rickard; Moons, Ellen; Koch, Norbert

    2016-02-01

    We reveal the rather complex interplay of contact-induced re-orientation and interfacial electronic structure - in the presence of Fermi-level pinning - at prototypical molecular heterojunctions comprising copper phthalocyanine (H16CuPc) and its perfluorinated analogue (F16CuPc), by employing ultraviolet photoelectron and X-ray absorption spectroscopy. For both layer sequences, we find that Fermi-level (EF) pinning of the first layer on the conductive polymer substrate modifies the work function encountered by the second layer such that it also becomes EF-pinned, however, at the interface towards the first molecular layer. This results in a charge transfer accompanied by a sheet charge density at the organic/organic interface. While molecules in the bulk of the films exhibit upright orientation, contact formation at the heterojunction results in an interfacial bilayer with lying and co-facial orientation. This interfacial layer is not EF-pinned, but provides for an additional density of states at the interface that is not present in the bulk. With reliable knowledge of the organic heterojunction’s electronic structure we can explain the poor performance of these in photovoltaic cells as well as their valuable function as charge generation layer in electronic devices.

  3. Organic heterojunctions: Contact-induced molecular reorientation, interface states, and charge re-distribution.

    PubMed

    Opitz, Andreas; Wilke, Andreas; Amsalem, Patrick; Oehzelt, Martin; Blum, Ralf-Peter; Rabe, Jürgen P; Mizokuro, Toshiko; Hörmann, Ulrich; Hansson, Rickard; Moons, Ellen; Koch, Norbert

    2016-01-01

    We reveal the rather complex interplay of contact-induced re-orientation and interfacial electronic structure - in the presence of Fermi-level pinning - at prototypical molecular heterojunctions comprising copper phthalocyanine (H16CuPc) and its perfluorinated analogue (F16CuPc), by employing ultraviolet photoelectron and X-ray absorption spectroscopy. For both layer sequences, we find that Fermi-level (EF) pinning of the first layer on the conductive polymer substrate modifies the work function encountered by the second layer such that it also becomes EF-pinned, however, at the interface towards the first molecular layer. This results in a charge transfer accompanied by a sheet charge density at the organic/organic interface. While molecules in the bulk of the films exhibit upright orientation, contact formation at the heterojunction results in an interfacial bilayer with lying and co-facial orientation. This interfacial layer is not EF-pinned, but provides for an additional density of states at the interface that is not present in the bulk. With reliable knowledge of the organic heterojunction's electronic structure we can explain the poor performance of these in photovoltaic cells as well as their valuable function as charge generation layer in electronic devices. PMID:26887445

  4. Organic heterojunctions: Contact-induced molecular reorientation, interface states, and charge re-distribution

    PubMed Central

    Opitz, Andreas; Wilke, Andreas; Amsalem, Patrick; Oehzelt, Martin; Blum, Ralf-Peter; Rabe, Jürgen P.; Mizokuro, Toshiko; Hörmann, Ulrich; Hansson, Rickard; Moons, Ellen; Koch, Norbert

    2016-01-01

    We reveal the rather complex interplay of contact-induced re-orientation and interfacial electronic structure – in the presence of Fermi-level pinning – at prototypical molecular heterojunctions comprising copper phthalocyanine (H16CuPc) and its perfluorinated analogue (F16CuPc), by employing ultraviolet photoelectron and X-ray absorption spectroscopy. For both layer sequences, we find that Fermi-level (EF) pinning of the first layer on the conductive polymer substrate modifies the work function encountered by the second layer such that it also becomes EF-pinned, however, at the interface towards the first molecular layer. This results in a charge transfer accompanied by a sheet charge density at the organic/organic interface. While molecules in the bulk of the films exhibit upright orientation, contact formation at the heterojunction results in an interfacial bilayer with lying and co-facial orientation. This interfacial layer is not EF-pinned, but provides for an additional density of states at the interface that is not present in the bulk. With reliable knowledge of the organic heterojunction’s electronic structure we can explain the poor performance of these in photovoltaic cells as well as their valuable function as charge generation layer in electronic devices. PMID:26887445

  5. Dark Energy:. the Absolute Electric Potential of the Universe

    NASA Astrophysics Data System (ADS)

    Jiménez, Jose Beltrán; Maroto, Antonio L.

    Is there an absolute cosmic electric potential? The recent discovery of the accelerated expansion of the universe could be indicating that this is certainly the case. In this essay we show that the consistency of the covariant and gauge-invariant theory of electromagnetism is truly questionable when considered on cosmological scales. Out of the four components of the electromagnetic field, Maxwell's theory contains only two physical degrees of freedom. However, in the presence of gravity, one of the "unphysical" states cannot be consistently eliminated, thus becoming real. This third polarization state is completely decoupled from charged matter, but can be excited gravitationally, thus breaking gauge invariance. On large scales the new state can be seen as a homogeneous cosmic electric potential, whose energy density behaves as a cosmological constant.

  6. High-resolution electronic spectroscopy of the doorway states to intramolecular charge transfer.

    PubMed

    Fleisher, Adam J; Bird, Ryan G; Zaleski, Daniel P; Pate, Brooks H; Pratt, David W

    2013-04-25

    Reported here are several of the ground, first, and second excited state structures and dipole moments of three benchmark intramolecular charge transfer (ICT) systems; 4-(1H-pyrrol-1-yl)benzonitrile (PBN), 4,4'-dimethylaminobenzonitrile (DMABN), and 4-(1-pyrrolidinyl)benzonitrile (PYRBN), isolated in the gas phase and probed by rotationally resolved spectroscopy in a molecular beam. The related molecules 1-phenylpyrrole (PP) and 4-aminobenzonitrile (ABN) also are discussed. We find that the S1 electronic state is of B symmetry in all five molecules. In PBN, a second excited state (S2) of A symmetry is found only ~400 cm(-1) above the presumed origin of the S1 state. The change in dipole moment upon excitation to the A state is measured to be Δμ ≈ 3.0 D, significantly smaller than the value predicted by theory and also smaller than that observed for the "anomalous" ICT band of PBN in solution. The B state dipole moments of DMABN and PYRBN are large, ~10.6 D, slightly larger than those attributed to "normal" LE fluorescence in solution. In addition, we find the unsaturated donor molecules (PP, PBN) to be twisted in their ground states and to become more planar upon excitation, even in the A state, whereas the saturated donor molecules (ABN, DMABN, PYRBN), initially planar, either remain planar or become more twisted in their excited states. It thus appears that the model that is appropriate for describing ICT in these systems depends on the geometry of the ground state. PMID:22913563

  7. Enhancing the estimation accuracy in low state-of-charge area: A novel onboard battery model through surface state of charge determination

    NASA Astrophysics Data System (ADS)

    Ouyang, Minggao; Liu, Guangming; Lu, Languang; Li, Jianqiu; Han, Xuebing

    2014-12-01

    In order to predict the battery remaining discharge energy in electric vehicles, an accurate onboard battery model is needed for the terminal voltage and state of charge (SOC) estimation in the whole SOC range. However, the commonly-used equivalent circuit model (ECM) provides limited accuracy in low-SOC area, which hinders the full use of battery remaining energy. To improve the low-SOC-area performance, this paper presents an extended equivalent circuit model (EECM) based on single-particle electrochemical model. In EECM, the solid-phase diffusion process is represented by the SOC difference within the electrode particle, and the terminal voltage is determined by the surface SOC (SOCsurf) representing the lithium concentration at the particle surface. Based on a large-format lithium-ion battery, the voltage estimation performance of ECM and EECM is compared in the entire SOC range (0-100%) under different load profiles, and the genetic algorithm is implemented in model parameterization. Results imply that the EECM could reduce the voltage error by more than 50% in low-SOC area. The SOC estimation accuracy is then discussed employing the extended Kalman filter, and the EECM also exhibits significant advantage. As a result, the EECM is very potential for real-time applications to enhance the voltage and SOC estimation precision especially for low-SOC cases.

  8. VRLA Ultrabattery for high-rate partial-state-of-charge operation

    NASA Astrophysics Data System (ADS)

    Lam, L. T.; Louey, R.; Haigh, N. P.; Lim, O. V.; Vella, D. G.; Phyland, C. G.; Vu, L. H.; Furukawa, J.; Takada, T.; Monma, D.; Kano, T.

    The objective of this study is to produce and test the hybrid valve-regulated Ultrabattery designed specifically for hybrid-electric vehicle duty, i.e., high-rate partial-state-of-charge operation. The Ultrabattery developed by CSIRO Energy Technology is a hybrid energy-storage device, which combines an asymmetric supercapacitor, and a lead-acid battery in one unit cells, taking the best from both technologies without the need for extra, expensive electronic controls. The capacitor will enhance the power and lifespan of the lead-acid battery as it acts as a buffer during high-rate discharging and charging. Consequently, this hybrid technology is able to provide and absorb charge rapidly during vehicle acceleration and braking. The work programme of this study is divided into two main parts, namely, field trial of prototype Ultrabatteries in a Honda Insight HEV and laboratory tests of prototype batteries. In this paper, the performance of prototype Ultrabatteries under different laboratory tests is reported. The evaluation of Ultrabatteries in terms of initial performance and cycling performance has been conducted at both CSIRO and Furukawa laboratories. The initial performance of prototype Ultrabatteries, such as capacity, power, cold cranking and self-discharge has been evaluated based upon the US FreedomCAR Battery Test Manual (DOE/ID-11069, October 2003). Results show that the Ultrabatteries meet, or exceed, respective targets of power, available energy, cold cranking and self-discharge set for both minimum and maximum power-assist HEVs. The cycling performance of prototype Ultrabatteries has been evaluated using: (i) simplified discharge and charge profile to simulate the driving conditions of micro-HEV; (ii) 42-V profile to simulate the driving conditions of mild-HEV and (iii) EUCAR and RHOLAB profiles to simulate the driving conditions of medium-HEV. For comparison purposes, nickel-metal-hydride (Ni-MH) cells, which are presently used in the Honda Insight HEV

  9. Fractional charge and inter-Landau-level states at points of singular curvature.

    PubMed

    Biswas, Rudro R; Son, Dam Thanh

    2016-08-01

    The quest for universal properties of topological phases is fundamentally important because these signatures are robust to variations in system-specific details. Aspects of the response of quantum Hall states to smooth spatial curvature are well-studied, but challenging to observe experimentally. Here we go beyond this prevailing paradigm and obtain general results for the response of quantum Hall states to points of singular curvature in real space; such points may be readily experimentally actualized. We find, using continuum analytical methods, that the point of curvature binds an excess fractional charge and sequences of quantum states split away, energetically, from the degenerate bulk Landau levels. Importantly, these inter-Landau-level states are bound to the topological singularity and have energies that are universal functions of bulk parameters and the curvature. Our exact diagonalization of lattice tight-binding models on closed manifolds demonstrates that these results continue to hold even when lattice effects are significant. An important technological implication of these results is that these inter-Landau-level states, being both energetically and spatially isolated quantum states, are promising candidates for constructing qubits for quantum computation. PMID:27436906

  10. The plasma environment, charge state, and currents of Saturn's C and D rings

    SciTech Connect

    Wilson, G.R. )

    1991-06-01

    The plasma environment of the Saturnian C and D rings is investigated by modeling the flow of ionospheric plasma from the mid- to low-latitude ionosphere to the vicinity of the rings. The model used is time-dependent and kinetic and incorporates the gravitational, centripetal, magnetic mirror and ambipolar electric forces. It was found that the plasma density near the C and D rings, at a given radial location, will experience a one to two order of magnitude diurnal variation. With a knowledge of the plasma density and temperature near these rings their charge state is investigated by use of a dust cloud charging model. The associated azimuthal currents are also found. Results show that the surface charge density of the C and D rings can show significant radial and azimuthal variations, due mainly to variations in the plasma density. In addition to its plasma density and temperature dependence the surface charge density will also depend on structural features of the rings such as the ring thickness and the nature of the particle size distribution. Its magnitude may vary over seven decades. The associated azimuthal currents carried by these rings will also show large diurnal variations resulting in field-aligned currents which close in the ionosphere as shown by Ip and Mendis (1983). However, the resulting ionospheric electric fields will probably not produce a significant amount of plasma convection in the topside ionosphere and inner plasmasphere as proposed by these authors, due in part to the level of the currents as well as the height-integrated Pedersen conductivities at the local times where the currents close.

  11. Re-creation of aerosol charge state found near HV power lines using a high voltage corona charger

    NASA Astrophysics Data System (ADS)

    Matthews, J. C.; Wright, M. D.; Biddiscombe, M. F.; Underwood, R.; Usmani, O. S.; Shallcross, D. E.; Henshaw, D. L.

    2015-10-01

    Corona ionisation from AC HV power lines (HVPL) can release ions into the environment, which have the potential to electrically charge pollutant aerosol in the atmosphere. It has been hypothesised that these charged particles have an enhanced probability of being deposited in human airways upon inhalation due to electrostatic attraction by image charge within the lung, with implications for human health. Carbonaceous aerosol particles from a Technegas generator were artificially charge-enhanced using a corona charger. Once generated, particles were passed through the charger, which was either on or off, and stored in a 15 litre conducting bag for ∼20 minutes to observe size and charge distribution changes over time. Charge states were estimated using two Sequential Mobility Particle Sizers measuring the size and mobility distributions. Charge-neutral particles were measured 7 times and positive particles 9 times, the average charge-neutral value of x was 1.00 (sd = 0.06) while the average positive value was 4.60 (0.72). The system will be used to generate positive or charge neutral particles for delivery to human volunteers in an inhalation study to assess the impact of charge on ultrafine (size < 100 nm) particle deposition.

  12. Automated charge state determination of complex isotope-resolved mass spectra by peak-target Fourier transform.

    PubMed

    Chen, Li; Yap, Yee Leng

    2008-01-01

    This study describes a new algorithm for charge state determination of complex isotope-resolved mass spectra. This algorithm is based on peak-target Fourier transform (PTFT) of isotope packets. It is modified from the widely used Fourier transform method because Fourier transform may give ambiguous charge state assignment for low signal-to-noise ratio (S/N) or overlapping isotopic clusters. The PTFT algorithm applies a novel "folding" strategy to enhance peaks that are symmetrically spaced about the targeted peak before applying the FT. The "folding" strategy multiplies each point to the high-m/z side of the targeted peak by its counterpart on the low-m/z side. A Fourier transform of this "folded" spectrum is thus simplified, emphasizing the charge state of the "chosen" ion, whereas ions of other charge states contribute less to the transformed data. An intensity-dependent technique is also proposed for charge state determination from frequency signals. The performance of PTFT is demonstrated using experimental electrospray ionization Fourier transform ion cyclotron resonance mass spectra. The results show that PTFT is robust for charge state determination of low S/N and overlapping isotopic clusters, and also useful for manual verification of potential hidden isotopic clusters that may be missed by the current analysis algorithms, i.e., AID-MS or THRASH. PMID:18293485

  13. Dynamics of H/sup +/ + Kr and H/sup +/ + Xe elastic and charge-transfer collisions: State-selected differential cross sections at low collision energies

    SciTech Connect

    Baer, M.; Dueren, R.; Friedrich, B.; Niedner, G.; Noll, M.; Toennies, J.P.

    1987-08-01

    Elastic and charge-transfer scattering of protons by Kr and Xe targets has been investigated in a crossed-beam experiment at collision energies E/sub c.m./ = 30.6 and 51.7 eV. The charge-transfer collisions led to the formation of Kr/sup +/( /sup 2/P/sub 3/2/, /sup 2/P/sub 1/2/)+H(n = 1) and Xe/sup +/( /sup 2/P/sub 3/2/, /sup 2/P/sub 1/2/)+H(n = 1,n = 2) products respectively. Interference patterns in the state-selected relative differential cross sections were clearly resolved and have been ascribed to primary and secondary rainbows and/or Stueckelberg-type oscillations. The H/sup +/+Xe collisions have also been investigated theoretically by the exact close-coupling method. A good agreement between theory and experiment has been found. A novel method for determining the absolute H-atom detection efficiency is suggested.

  14. 20 CFR 404.1205 - Absolute coverage groups.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 20 Employees' Benefits 2 2010-04-01 2010-04-01 false Absolute coverage groups. 404.1205 Section... INSURANCE (1950- ) Coverage of Employees of State and Local Governments What Groups of Employees May Be Covered § 404.1205 Absolute coverage groups. (a) General. An absolute coverage group is a...

  15. Particle acceleration through multiple conversions from a charged into a neutral state and back

    NASA Astrophysics Data System (ADS)

    Derishev, E. V.; Aharonian, F. A.; Kocharovsky, V. V.; Kocharovsky, Vl. V.

    2003-08-01

    We propose a new means for a quick and efficient acceleration of protons and/or electrons in relativistic bulk flows. The maximum attainable particle energies are limited either by radiative losses or by the condition of confinement in the magnetic field. The new mechanism takes advantage of a conversion of particles from the charged state (protons, electrons or positrons) into a neutral state (neutrons or photons) and back. In most cases, the conversion is photon induced and requires the presence of intense radiation fields, but under special circumstances the converter acceleration mechanism may operate via other charge-changing reactions, for example, inelastic nucleon-nucleon collisions. As in the traditional, “stochastic” (or diffusive) acceleration models, the acceleration cycle in the proposed scenario consists of the escape of particles from the relativistic flow followed by their return back after deflection from the ambient magnetic field. The difference is that the charge-changing reactions, which occur during the cycle, allow accelerated particles to increase their energies in each cycle by a factor much larger than 2 and usually roughly equal to the bulk Lorentz factor squared. The emerging spectra of accelerated particles can be very hard and their maximum energy in some cases is larger than in the standard mechanism. This significantly reduces the required energy budget of the sources of the highest-energy particles observed in cosmic rays. The proposed acceleration mechanism has a distinctive feature—it unavoidably creates neutral beams, consisting of photons, neutrinos, or neutrons, whose beam pattern may be much broader than the inverse Lorentz factor of the relativistic flow. Also, the new mechanism may serve as an efficient means of transferring the energy of bulk motion to gamma radiation and, if the accelerated particles are nucleons, inevitably produces high-energy neutrinos at a relative efficiency approaching ≳50%.

  16. Chiral and nonchiral edge states in quantum Hall systems with charge density modulation

    NASA Astrophysics Data System (ADS)

    Szumniak, Paweł; Klinovaja, Jelena; Loss, Daniel

    2016-06-01

    We consider a system of weakly coupled wires with quantum Hall effect (QHE) and in the presence of a spatially periodic modulation of the chemical potential along the wire, equivalent to a charge density wave (CDW). We investigate the competition between the two effects which both open a gap. We show that by changing the ratio between the amplitudes of the CDW modulation and the tunneling between wires, one can switch between nontopological CDW-dominated phase to topological QHE-dominated phase. Both phases host edge states of chiral and nonchiral nature robust to on-site disorder. However, only in the topological phase, the edge states are immune to disorder in the phase shifts of the CDWs. We provide analytical solutions for filling factor ν =1 and study numerically effects of disorder as well as present numerical results for higher filling factors.

  17. High intensity high charge state ion beam production with an evaporative cooling magnet ECRIS.

    PubMed

    Lu, W; Qian, C; Sun, L T; Zhang, X Z; Fang, X; Guo, J W; Yang, Y; Feng, Y C; Ma, B H; Xiong, B; Ruan, L; Zhao, H W; Zhan, W L; Xie, D

    2016-02-01

    LECR4 (Lanzhou ECR ion source No. 4) is a room temperature electron cyclotron resonance ion source, designed to produce high current, high charge state ion beams for the SSC-LINAC injector (a new injector for sector separated cyclotron) at the Institute of Modern Physics. LECR4 also serves as a PoP machine for the application of evaporative cooling technology in accelerator field. To achieve those goals, LECR4 ECR ion source has been optimized for the operation at 18 GHz. During 2014, LECR4 ion source was commissioned at 18 GHz microwave of 1.6 kW. To further study the influence of injection stage to the production of medium and high charge state ion beams, in March 2015, the injection stage with pumping system was installed, and some optimum results were produced, such as 560 eμA of O(7+), 620 eμA of Ar(11+), 430 eμA of Ar(12+), 430 eμA of Xe(20+), and so on. The comparison will be discussed in the paper. PMID:26931956

  18. High intensity high charge state ion beam production with an evaporative cooling magnet ECRIS

    NASA Astrophysics Data System (ADS)

    Lu, W.; Qian, C.; Sun, L. T.; Zhang, X. Z.; Fang, X.; Guo, J. W.; Yang, Y.; Feng, Y. C.; Ma, B. H.; Xiong, B.; Ruan, L.; Zhao, H. W.; Zhan, W. L.; Xie, D.

    2016-02-01

    LECR4 (Lanzhou ECR ion source No. 4) is a room temperature electron cyclotron resonance ion source, designed to produce high current, high charge state ion beams for the SSC-LINAC injector (a new injector for sector separated cyclotron) at the Institute of Modern Physics. LECR4 also serves as a PoP machine for the application of evaporative cooling technology in accelerator field. To achieve those goals, LECR4 ECR ion source has been optimized for the operation at 18 GHz. During 2014, LECR4 ion source was commissioned at 18 GHz microwave of 1.6 kW. To further study the influence of injection stage to the production of medium and high charge state ion beams, in March 2015, the injection stage with pumping system was installed, and some optimum results were produced, such as 560 eμA of O7+, 620 eμA of Ar11+, 430 eμA of Ar12+, 430 eμA of Xe20+, and so on. The comparison will be discussed in the paper.

  19. Exciton Transfer and Emergent Excitonic States in Oppositely-Charged Conjugated Polyelectrolyte Complexes.

    PubMed

    Hollingsworth, William R; Segura, Carmen; Balderrama, Jonathan; Lopez, Nathaniel; Schleissner, Pamela; Ayzner, Alexander L

    2016-08-11

    Photosynthetic organisms have mastered the use of "soft" macromolecular assemblies for light absorption and concentration of electronic excitation energy. Nature's design centers on an optically inactive protein-based backbone that acts as a host matrix for an array of light-harvesting pigment molecules. The pigments are organized in space such that excited states can migrate between molecules, ultimately delivering the energy to the reaction center. Here we report our investigation of an artificial light-harvesting energy transfer antenna based on complexes of oppositely charged conjugated polyelectrolytes (CPEs). The conjugated backbone and the charged side chains of the CPE lead to an architecture that simultaneously functions as a structural scaffold and an electronic energy "highway". We find that the process of ionic complex formation leads to a remarkable change in the excitonic wavefunction of the energy acceptor, which manifests in a dramatic increase in the fluorescence quantum yield. We argue that the extended backbone of the donor CPE effectively templates a planarized acceptor polymer, leading to excited states that are highly delocalized along the polymer backbone. PMID:27428604

  20. Quartz resonator state-of-charge monitor for lead-acid batteries

    NASA Astrophysics Data System (ADS)

    Cernosek, R. W.; Martin, S. J.; Wessendorf, K. O.; Rumpf, A. N.

    We have demonstrated that a thickness shear mode quartz resonator can be used as a real-time, in situ monitor of the state-of-charge of lead-acid batteries. The resonator is sensitive to changes in the density and viscosity of the sulfuric acid electrolyte. Both of these liquid parameters vary monotonically with the battery state-of-charge. This new monitor is more precise than sampling hydrometers, and since it is compatible with the corrosive electrolyte environment, it can be used for in situ monitoring. A TSM resonator consists of gold electrodes deposited on opposite surfaces of a thin AT-cut quartz crystal. When an RF voltage is applied to the electrodes, a shear strain is introduced in the piezoelectric quartz and mechanical resonance occurs between the surfaces. A liquid in contact with one of the quartz surfaces is viscously entrained, which perturbs the resonant frequency and resonance magnitude. If the surface is smooth, the changes in both frequency and magnitude are proportional to (rho(eta))(exp (1/2)), where rho is the liquid density and eta is the viscosity.

  1. Quartz resonator state-of-charge monitor for lead-acid batteries

    SciTech Connect

    Cernosek, R.W.; Martin, S.J.; Wessendorf, K.O.; Rumpf, A.N.

    1994-06-01

    We have demonstrated that a thickness shear mode quartz resonator can be used as a real-time, in situ monitor of the state-of-charge of lead-acid batteries. The resonator is sensitive to hanges in the density and viscosity of the sulfuric acid electrolyte. Both of these liquid parameters vary monotonically with the battery state-of-charge. This new monitor is more precise than sampling hydrometers, and since it is compatible with the Corrosive electrolyte environment, it can be used for in situ monitoring. A TSM resonator consists of gold electrodes deposited on opposite surfaces of a thin AT-cut quartz crystal. When an RF voltage is applied to the electrodes, a shear strain is introduced in the piezoelectric quartz and mechanical resonance occurs between the surfaces. A liquid in contact with one of the quartz surfaces is viscously entrained, which perturbs the resonant frequency and resonance magnitude. If the surface is smooth, the changes in both frequency and magnitude are proportional to ({rho}{eta}) {sup {1/2}}, where {rho} is the liquid density and {eta} is the viscosity.

  2. Excited state structural evolution during charge-transfer reactions in betaine-30.

    PubMed

    Ruchira Silva, W; Frontiera, Renee R

    2016-07-27

    Ultrafast photo-induced charge-transfer reactions are fundamental to a number of photovoltaic and photocatalytic devices, yet the multidimensional nature of the reaction coordinate makes these processes difficult to model theoretically. Here we use femtosecond stimulated Raman spectroscopy to probe experimentally the structural changes occurring following photoexcitation in betaine-30, a canonical intramolecular charge-transfer complex. We observe changes in vibrational mode frequencies and amplitudes on the femtosecond timescale, which for some modes results in frequency shifts of over 20 cm(-1) during the first 200 fs following photoexcitation. These rapid mode-specific frequency changes track the planarization of the molecule on the 400 ± 100 fs timescale. Oscillatory amplitude modulations of the observed high frequency Raman modes indicate coupling between specific high frequency and low frequency vibrational motions, which we quantify for 6 low frequency modes and 4 high frequency modes. Analysis of the mode-specific kinetics is suggestive of the existence of a newly discovered electronic state involved in a relaxation pathway, which may be a low-lying triplet state. These results directly track the multiple nuclear coordinates involved in betaine-30's reactive pathway, and should be of use in rationally designing molecular systems with rapid electron transfer processes. PMID:26725657

  3. Fuzzy modelling for the state-of-charge estimation of lead-acid batteries

    NASA Astrophysics Data System (ADS)

    Burgos, Claudio; Sáez, Doris; Orchard, Marcos E.; Cárdenas, Roberto

    2015-01-01

    This paper introduces a novel fuzzy model based structure for the characterisation of discharge processes in lead-acid batteries. This structure is based on a fuzzy model that characterises the relationship between the battery open-circuit voltage (Voc), the state of charge (SoC), and the discharge current. The model is identified and validated using experimental data that is obtained from an experimental system designed to test battery banks with several charge/discharge profiles. For model identification purposes, two standard experimental tests are implemented; one of these tests is used to identify the Voc-SoC curve, while the other helps to identify additional parameters of the model. The estimation of SoC is performed using an Extended Kalman Filter (EKF) with a state transition equation that is based on the proposed fuzzy model. Performance of the proposed estimation framework is compared with other parametric approaches that are inspired on electrical equivalents; e.g., Thevenin, Plett, and Copetti.

  4. Electron capture into large-l Rydberg states of multiply charged ions escaping from solid surfaces

    NASA Astrophysics Data System (ADS)

    Nedeljković, N.; Nedeljković, Lj.; Mirković, M.

    2003-07-01

    We have investigated the electron capture into large-l Rydberg states of multiply charged ionic projectiles (e.g., the core charges Z=6, 7, and 8) escaping solid surfaces with intermediate velocities (v≈1 a.u.) in the normal emergence geometry. A model of the nonresonant electron capture from the solid conduction band into the moving large angular-momentum Rydberg states of the ions is developed through a generalization of our results obtained previously for the low-l cases (l=0, 1, and 2). The model is based on the two-wave-function dynamics of the Demkov-Ostrovskii type. The electron exchange process is described by a mixed flux through a moving plane (“Firsov plane”), placed between the solid surface and the ionic projectile. Due to low eccentricities of the large-l Rydberg systems, the mixed flux must be evaluated through the whole Firsov plane. It is for this purpose that a suitable asymptotic method is developed. For intermediate ionic velocities and for all relevant values of the principal quantum number n≈Z, the population probability Pnl is obtained as a nonlinear l distribution. The theoretical predictions concerning the ions S VI, Cl VII, and Ar VIII are compared with the available results of the beam-foil experiments.

  5. Hospitalization frequency and charges for neurocysticercosis, United States, 2003-2012.

    PubMed

    O'Neal, Seth E; Flecker, Robert H

    2015-06-01

    Neurocysticercosis, brain infection with Taenia solium larval cysts, causes substantial neurologic illness around the world. To assess the effect of neurocysticercosis in the United States, we reviewed hospitalization discharge data in the Nationwide Inpatient Sample for 2003-2012 and found an estimated 18,584 hospitalizations for neurocysticercosis and associated hospital charges totaling >US $908 million. The risk for hospitalization was highest among Hispanics (2.5/100,000 population), a rate 35 times higher than that for the non-Hispanic white population. Nearly three-quarters of all hospitalized patients with neurocysticercosis were Hispanic. Male sex and age 20-44 years also incurred increased risk. In addition, hospitalizations and associated charges related to cysticercosis far exceeded those for malaria and were greater than for those for all other neglected tropical diseases combined. Neurocysticercosis is an increasing public health concern in the United States, especially among Hispanics, and costs the US health care system a substantial amount of money. PMID:25988221

  6. Self/anti-self charge conjugate states in the helicity basis

    SciTech Connect

    Dvoeglazov, Valeriy V.

    2013-07-23

    We construct self/anti-self charge conjugate (Majorana-like) states for the (1/2,0)⊕(0,1/2) representation of the Lorentz group, and their analogs for higher spins within the quantum field theory. The problem of the basis rotations and that of the selection of phases in the Dirac-like and Majorana-like field operators are considered. The discrete symmetries properties (P, C, T) are studied. Particular attention has been paid to the question of (anti)commutation of the Charge conjugation operator and the Parity in the helicity basis. Dynamical equations have also been presented. In the (1/2,0)⊕(0,1/2) representation they obey the Dirac-like equation with eight components, which has been first introduced by Markov. Thus, the Fock space for corresponding quantum fields is doubled (as shown by Ziino). The chirality and the helicity (two concepts which are frequently confused in the literature) for Dirac and Majorana states have been discussed.

  7. Magnetic measurements of the transuranium elements and charge state characterization of actinides in monazite. Progress report

    SciTech Connect

    Huray, P. G.

    1980-01-01

    A micromagnetic susceptometer for the purpose of measuring extremely small sample quantities (on the microgram level) was designed, constructed, and calibrated in previous years. (The 1979 progress report gives details of its operation.) This device has operated without significant downtime in this funding period, and much progress has been made in the magnetic characterization of elements beyond Am in the periodic table. This program has roughly doubled man's knowledge of magnetism in Cm, Bk, and Cf, and includes the only Es magnetic measurements to date. The incorporation of an automatic data collection system in this period has made analysis much more accurate, and has allowed quicker turnaround of compounds and metals for study. Results obtained for the compounds and metals studied this year are summarized. The lanthanide orthophosphates are being investigated as an alternate means of primary containment for high-level actinide wastes. Researchers at the Oak Ridge National Laboratory are involved in preparation of actinide-doped compounds for all of the lanthanide transition series (La through Lu) for a study of leaching characteristics and E.S.R. classification. To aid this study the charge state of /sup 237/Np or /sup 57/Fe has been identified, either in the as-prepared compounds or following radioactive decay of /sup 241/Am via the Moessbauer Effect. The final charge state will be an influential variable in the immobilization characteristics of the waste products stored in this synthetic monazite form. 10 figures, 1 table. (RWR)

  8. 26Al measurements below 500 kV in charge state 2+

    NASA Astrophysics Data System (ADS)

    Müller, Arnold Milenko; Christl, Marcus; Lachner, Johannes; Synal, Hans-Arno; Vockenhuber, Christof; Zanella, Claudia

    2015-10-01

    The use of helium as stripper gas improved the measurement efficiency of compact AMS systems for many radionuclides significantly because of a higher mean charge state and reduced scattering losses compared with other conventional gases. Recent tests at the ETH 500 kV AMS facility (Tandy) with aluminum have demonstrated that a transmission of more than 50% is achievable in the charge state 2+ at terminal voltages between 300 and 500 kV. On the other hand the m/q interference of 13C1+ entering the detector at very high intensity has to be suppressed. Based on first positive results with a very simple absorber cell a more elaborate absorber detector configuration was designed and built in order to eliminate the carbon interference. The suppression of carbon with the new detector-absorber design has been studied extensively at 300 kV (950 keV) and 500 kV (1550 keV) and the results are compared with simulated data. With the new configuration an overall transmission for 26Al of more than 42% at 500 kV and about 30% at 300 kV terminal voltage is achieved, while 26Al/27Al blank ratios of aluminum targets in the range of 5-14·10-15 are measured.

  9. Constraints on CME Evolution from in situ Observations of Ionic Charge States

    NASA Technical Reports Server (NTRS)

    Gruesbeck, Jacob R.; Lepri, Susan T.; Zurbuchen, Thomas H.; Antiochos, Spiro K.

    2010-01-01

    We present a novel procedure for deriving the physical properties of Coronal Mass Ejections (CMES) in the corona. Our methodology uses in-situ measurements of ionic charge states of C, O, Si and Fe in the heliosphere and interprets them in the context of a model for the early evolution of ICME plasma, between 2 - 5 R-solar. We find that the data can be fit only by an evolution that consists of an initial heating of the plasma, followed by an expansion that ultimately results in cooling. The heating profile is consistent with a compression of coronal plasma due to flare reconnect ion jets and an expansion cooling due to the ejection, as expected from the standard CME/flare model. The observed frozen-in ionic charge states reflect this time-history and, therefore, provide important constraints for the heating and expansion time-scales, as well as the maximum temperature the CME plasma is heated to during its eruption. Furthermore, our analysis places severe limits on the possible density of CME plasma in the corona. We discuss the implications of our results for CME models and for future analysis of ICME plasma composition.

  10. Abundances and charge states in quiet-time low-energy ion fluxes at 1 AU

    NASA Astrophysics Data System (ADS)

    Kecskemety, Karoly; Zeldovich, Mariya; Klecker, Berndt; Logachev, Yurii

    Abundances of C and Fe ions with energies 0.04-1.28 MeV/nuc in the 23rd solar activity cycle are examined in the quiet-time fluxes using ACE, SOHO and STEREO data. They are com-bined with charge state measurement data from SEPICA (ACE, 0.18-0.43 MeV/nuc). Quiet periods of solar activity were selected using the criteria a) Jp < 2x10-4 protons/(cm2 s sr MeV) for 4-8 MeV protons (from EPHIN/SOHO) and b) the ratio H/He < 10 at these energies. The values of C/O and Fe/O were determined over the solar cycle and the following was found. In about 50% of the time intervals during high activity they both were near the average values observed in the solar corona, whereas at solar minimum in more than 90% of the periods the ratios were around the solar wind values. Most of the quiet time periods around maximum, which have sufficient statistics show high average Fe charge states (>15), consistent with im-pulsive solar event origin. During the SC minima the abundances in almost all cases correspond to solar wind values. The results obtained suggest that the active structures on the Sun arising at low solar activity are mostly responsible for background particle fluxes at these energies. There may be microflares, disappearing of ribbons, soft X-ray bright points etc.

  11. Hospitalization Frequency and Charges for Neurocysticercosis, United States, 2003–2012

    PubMed Central

    Flecker, Robert H.

    2015-01-01

    Neurocysticercosis, brain infection with Taenia solium larval cysts, causes substantial neurologic illness around the world. To assess the effect of neurocysticercosis in the United States, we reviewed hospitalization discharge data in the Nationwide Inpatient Sample for 2003–2012 and found an estimated 18,584 hospitalizations for neurocysticercosis and associated hospital charges totaling >US $908 million. The risk for hospitalization was highest among Hispanics (2.5/100,000 population), a rate 35 times higher than that for the non-Hispanic white population. Nearly three-quarters of all hospitalized patients with neurocysticercosis were Hispanic. Male sex and age 20–44 years also incurred increased risk. In addition, hospitalizations and associated charges related to cysticercosis far exceeded those for malaria and were greater than for those for all other neglected tropical diseases combined. Neurocysticercosis is an increasing public health concern in the United States, especially among Hispanics, and costs the US health care system a substantial amount of money. PMID:25988221

  12. Charge separation in solid-state dye-sensitized heterojunction solar cells

    SciTech Connect

    Bach, U.; Tachibana, Yasuhiro; Moser, J.E.; Haque, S.A.; Durrant, J.R.; Graetzel, M.; Klug, D.R.

    1999-08-18

    Dye-sensitized nanocrystalline solar cells are presently under intensive investigation, as they offer an attractive alternative to conventional p--n junction devices. Solid-state versions have been described where the electrolyte present in the pores of the malodorous oxide film is replaced by a large band gap p-type semiconductor. In this way, a solid-state heterojunction of very large contact area is formed. Light is absorbed by the dye that is located at the interface. Upon excitation, the dye injects electrons into the conduction band of the oxide and is regenerated by hole injection into the p-type conductor. High incident photon-to-electric current conversion efficiencies have been achieved recently with a cell consisting of a dye-derivatized mesoporous TiO{sub 2} film contacted by a new organic hole conductor. The great advantage of such systems with regard to conventional p--n junctions is that only majority carriers are involved in the photoelectric conversion process. Moreover, these are generated by the dye precisely at the site of the junction where the electric field is maximal, enhancing charge separation. Photoelectric conversion by conventional solar cells involves minority carriers whose lifetime is restricted due to recombination. As they are generated throughout the semiconductor and away from the junction, expensive high-purity materials are required in order to maintain the minority carrier diffusion length at a level where current losses are avoided. While the dynamics of photoinduced redo processes in photoelectrochemical systems have been studied in great detail, little is known about the electron-transfer dynamics in solid-state sensitized junctions. Here the authors report for the first time on the direct observation of photoinduced, interfacial charge separation across a dye-sensitized solid-state heterojunction by means of picosecond transient absorption laser spectroscopy.

  13. Charge Transfer States in Dilute Donor-Acceptor Blend Organic Heterojunctions.

    PubMed

    Liu, Xiao; Ding, Kan; Panda, Anurag; Forrest, Stephen R

    2016-08-23

    We study the charge transfer (CT) states in small-molecule blend heterojunctions comprising the nonpolar donor, tetraphenyldibenzoperiflanthene (DBP), and the acceptor, C70, using electroluminescence and steady-state and time-resolved photoluminescence spectroscopy along with density functional theory calculations. We find that the CT exciton energy blue shifts as the C70 concentration in the blend is either decreased or increased away from 50 vol %. At 20 K, the increase in CT state lifetime is correlated with the increasing diameter of C70 nanocrystallites in the blends. A quantum confinement model is used to quantitatively describe the dependence of both CT energy and lifetime on the C70 or DBP domain size. Two discrete CT emission peaks are observed for blends whose C70 concentration is >65%, at which point C70 nanocrystallites with diameters >4 nm appear in high-resolution transmission electron micrographs. The presence of two CT states is attributed to coexistence of crystalline C70 and amorphous phases in the blends. Furthermore, analysis of CT dissociation efficiency versus photon energy suggests that the >90% dissociation efficiency of delocalized CT2 states from the crystalline phase significantly contributes to surprisingly efficient photogeneration in highly dilute (>80% C70) DBP/C70 heterojunctions. PMID:27487403

  14. Mixing of exciton and charge-transfer states in light-harvesting complex Lhca4.

    PubMed

    Novoderezhkin, Vladimir I; Croce, Roberta; Wahadoszamen, Md; Polukhina, Iryna; Romero, Elisabet; van Grondelle, Rienk

    2016-07-28

    Lhca4 is one of the peripheral antennae of higher plant photosystem I and it is characterized by the presence of chlorophyll a with absorption and emission bands around 30 nm red-shifted compared to those of the other chlorophylls associated with plant complexes. In this work we have investigated the origin of this red shift by using the recent structure of Lhca4 (Qin et al., Science, 2015, 348, 989) to build an exciton model that includes a charge-transfer (CT) state mixed with the excited-state manifold. A simultaneous quantitative fit of absorption, linear dichroism, fluorescence, and Stark absorption spectra of the wild-type Lhca4 and NH mutant (where the sites involved in CT are affected) enables us to determine the origin of the CT state and explore its spectral signatures. A huge borrowing of dipole strength by the CT, accompanied by anomalous broadening and red-shifting of the fluorescence as well as dramatic changes in the Stark spectrum, can be accounted for by a model implying an exciton-type mixing between excited states and CT states. PMID:27375175

  15. High-Fidelity Rapid Initialization and Read-Out of an Electron Spin via the Single Donor D- Charge State

    NASA Astrophysics Data System (ADS)

    Watson, T. F.; Weber, B.; House, M. G.; Büch, H.; Simmons, M. Y.

    2015-10-01

    We demonstrate high-fidelity electron spin read-out of a precision placed single donor in silicon via spin selective tunneling to either the D+ or D- charge state of the donor. By performing read-out at the stable two electron D0↔D- charge transition we can increase the tunnel rates to a nearby single electron transistor charge sensor by nearly 2 orders of magnitude, allowing faster qubit read-out (1 ms) with minimum loss in read-out fidelity (98.4%) compared to read-out at the D+↔D0 transition (99.6%). Furthermore, we show that read-out via the D- charge state can be used to rapidly initialize the electron spin qubit in its ground state with a fidelity of FI=99.8 %.

  16. Conformation-Controlled Diplatinum(II)-Ferrocene Dyads to Achieve Long-Lived Charge-Separated States.

    PubMed

    Wang, Ge-Xia; Feng, Ke; Crossley, Maxwell J; Xing, Ling-Bao; Xiao, Hong-Yan; Li, Wen; Tung, Chen-Ho; Wu, Li-Zhu

    2016-08-16

    Square-planar polypyridyl platinum(II) complexes possess a rich range of structural and spectroscopic properties that are ideal for designing artificial photosynthetic centers. Taking advantage of the directionality in the charge-transfer excitation from the metal to the polypyridyl ligand, we describe here diplatinum(II)-ferrocene dyads, open-butterfly-like dyad 1 and closed-butterfly-like dyad 2, which were designed to understand the conformation and orientation effects to prolong the lifetime of charge-separated state. In contrast to the open-butterfly-like dyad 1, the closed-butterfly-like dyad 2 shows three-times long lifetime of charge separated state upon photoexcitation, demonstrating that the orientation in the rigid structure of dyad 2 is a very important issue to achieve long-lived charge separated state. PMID:27339465

  17. Online state of charge and model parameters estimation of the LiFePO4 battery in electric vehicles using multiple adaptive forgetting factors recursive least-squares

    NASA Astrophysics Data System (ADS)

    Duong, Van-Huan; Bastawrous, Hany Ayad; Lim, KaiChin; See, Khay Wai; Zhang, Peng; Dou, Shi Xue

    2015-11-01

    This paper deals with the contradiction between simplicity and accuracy of the LiFePO4 battery states estimation in the electric vehicles (EVs) battery management system (BMS). State of charge (SOC) and state of health (SOH) are normally obtained from estimating the open circuit voltage (OCV) and the internal resistance of the equivalent electrical circuit model of the battery, respectively. The difficulties of the parameters estimation arise from their complicated variations and different dynamics which require sophisticated algorithms to simultaneously estimate multiple parameters. This, however, demands heavy computation resources. In this paper, we propose a novel technique which employs a simplified model and multiple adaptive forgetting factors recursive least-squares (MAFF-RLS) estimation to provide capability to accurately capture the real-time variations and the different dynamics of the parameters whilst the simplicity in computation is still retained. The validity of the proposed method is verified through two standard driving cycles, namely Urban Dynamometer Driving Schedule and the New European Driving Cycle. The proposed method yields experimental results that not only estimated the SOC with an absolute error of less than 2.8% but also characterized the battery model parameters accurately.

  18. The low-energy, charge-transfer excited states of 4-amino-4-prime-nitrodiphenyl sulfide

    NASA Technical Reports Server (NTRS)

    O'Connor, Donald B.; Scott, Gary W.; Tran, Kim; Coulter, Daniel R.; Miskowski, Vincent M.; Stiegman, Albert E.; Wnek, Gary E.

    1992-01-01

    Absorption and emission spectra of 4-amino-4-prime-nitrodiphenyl sulfide in polar and nonpolar solvents were used to characterize and assign the low-energy excited states of the molecule. Fluorescence-excitation anisotropy spectra and fluorescence quantum yields were also used to characterize the photophysics of these states. The lowest-energy fluorescent singlet state was determined to be an intramolecular charge transfer (ICT) state involving transfer of a full electron charge from the amino to the nitro group yielding a dipole moment of about 50 D. A low-energy, intense absorption band is assigned as a transition to a different ICT state involving a partial electron charge transfer from sulfur to the nitro group.

  19. The role of charge-transfer states in energy transfer and dissipation within natural and artificial bacteriochlorophyll-proteins

    PubMed Central

    Wahadoszamen, Md.; Margalit, Iris; Ara, Anjue Mane; van Grondelle, Rienk; Noy, Dror

    2014-01-01

    Understanding how specific protein environments affect the mechanisms of non-radiative energy dissipation within densely assembled chlorophylls in photosynthetic protein complexes is of great interest to the construction of bioinspired solar energy conversion devices. Mixing of charge-transfer and excitonic states in excitonically interacting chlorophylls was implicated in shortening excited states lifetimes but its relevance to active control of energy dissipation in natural systems is under considerable debate. Here we show that the degree of fluorescence quenching in two similar pairs of excitonically interacting bacteriochlorophyll derivatives is directly associated with increasing charge transfer character in the excited state, and that the protein environment may control non-radiative dissipation by affecting the mixing of charge transfer and excitonic states. The capability of local protein environments to determine the fate of excited states, and thereby to confer different functionalities to excitonically coupled dimers substantiates the dimer as the basic functional element of photosynthetic enzymes. PMID:25342121

  20. A unified approach to modelling the charge state of monatomic hydrogen and other defects in crystalline silicon

    SciTech Connect

    Sun, Chang Rougieux, Fiacre E.; Macdonald, Daniel

    2015-01-28

    There are a number of existing models for estimating the charge states of defects in silicon. In order of increasing complexity, these are (a) the Fermi-Dirac distribution, (b) the Shockley-Last model, (c) the Shockley-Read-Hall model, and (d) the Sah-Shockley model. In this work, we demonstrate their consistency with the general occupancy ratio α, and show that this parameter can be universally applied to predict the charge states of both monovalent and multivalent deep levels, under either thermal equilibrium or steady-state conditions with carrier injection. The capture cross section ratio is shown to play an important role in determining the charge state under non-equilibrium conditions. The application of the general occupancy ratio is compared with the quasi-Fermi levels, which are sometimes used to predict the charge states in the literature, and the conditions where the latter can be a good approximation are identified. The general approach is then applied to the prediction of the temperature- and injection level-dependent charge states for the technologically important case of multivalent monatomic hydrogen, and several other key monovalent deep levels including Fe, Cr, and the boron-oxygen complex in silicon solar cells. For the case of hydrogen, we adapt the model of Herring et al., which describes the charge states of hydrogen in thermal equilibrium, and generalize it for non-equilibrium conditions via the inclusion of the general occupancy ratio, while retaining the pre-factors which make the model more complete. Based on these results, the impact of temperature and injection on the hydrogenation of the key monovalent defects, and other pairing reactions, are discussed, demonstrating that the presented model provides a rigorous methodology for understanding the impact of charge states.

  1. A unified approach to modelling the charge state of monatomic hydrogen and other defects in crystalline silicon

    NASA Astrophysics Data System (ADS)

    Sun, Chang; Rougieux, Fiacre E.; Macdonald, Daniel

    2015-01-01

    There are a number of existing models for estimating the charge states of defects in silicon. In order of increasing complexity, these are (a) the Fermi-Dirac distribution, (b) the Shockley-Last model, (c) the Shockley-Read-Hall model, and (d) the Sah-Shockley model. In this work, we demonstrate their consistency with the general occupancy ratio α, and show that this parameter can be universally applied to predict the charge states of both monovalent and multivalent deep levels, under either thermal equilibrium or steady-state conditions with carrier injection. The capture cross section ratio is shown to play an important role in determining the charge state under non-equilibrium conditions. The application of the general occupancy ratio is compared with the quasi-Fermi levels, which are sometimes used to predict the charge states in the literature, and the conditions where the latter can be a good approximation are identified. The general approach is then applied to the prediction of the temperature- and injection level-dependent charge states for the technologically important case of multivalent monatomic hydrogen, and several other key monovalent deep levels including Fe, Cr, and the boron-oxygen complex in silicon solar cells. For the case of hydrogen, we adapt the model of Herring et al., which describes the charge states of hydrogen in thermal equilibrium, and generalize it for non-equilibrium conditions via the inclusion of the general occupancy ratio, while retaining the pre-factors which make the model more complete. Based on these results, the impact of temperature and injection on the hydrogenation of the key monovalent defects, and other pairing reactions, are discussed, demonstrating that the presented model provides a rigorous methodology for understanding the impact of charge states.

  2. Charge asymmetry and relativistic corrections in pure vibrational states of the HD+ ion

    NASA Astrophysics Data System (ADS)

    Stanke, Monika; Adamowicz, Ludwik

    2014-03-01

    In this work we present very accurate quantum-mechanical calculations of all bound pure vibrational states of the HD+ ion performed without the Born-Oppenheimer (BO) approximation. All three particles forming the system are treated on equal footing. The approach involves separating the center-of-mass motion from the laboratory-frame nonrelativistic Hamiltonian and expending the wave function of each considered state in terms of all-particle explicitly correlated Gaussian functions. The Gaussian exponential parameters are variationally optimized with the aid of the analytical energy gradient calculated with respect to these parameters. For each state the leading relativistic corrections are calculated as expectation values of the corresponding operators with the non-BO wave function of the state. The non-BO approach allows us to directly describe the charge asymmetry in HD+ which is due to the nuclear-mass asymmetry. The effect increases with the vibrational excitation and affects the values of the relativistic corrections. This phenomenon is the focus of the present study.

  3. Charge state of anomalous cosmic-ray nitrogen, oxygen, and neon: SAMPEX observations

    NASA Technical Reports Server (NTRS)

    Klecker, B.; Mcnab, M. C.; Blake, J. B.; Hamilton, D. C.; Hovestadt, D.; Kaestle, H.; Looper, M. D.; Mason, G. M.; Mazur, J. E.; Scholer, M.

    1995-01-01

    We report observations of the ionization state of anomalous cosmic-ray (ACR) nitrogen, oxygen, and neon during the period 1992 October to 1993 May, carried out with instrumentation on the Solar, Anomalous & Magnetospheric Particle Explorer (SAMPEX) spacecraft. The low-altitude (510 x 675 km) and high-inclination (82 deg) orbit enables SAMPEX to sample the interplanetary ACR fluxes on each polar pass and then to observe the cutoff of these fluxes by the geomagnetic field at lower latitudes. The arrival time and direction of each ion is recorded by the instruments, allowing detailed calculations of the particle's trajectory through the Earth's magnetic field and thereby placing upper limits on the ionization state of the particles. We find (a) that ACR nitrogen, oxygen, and neon each contain singly ionized particles and (b) that ACR oxygen is predominantly singly ionized with an upper limit of 10% for higher ionization states. These ionization states confirm theories of ACR origin as neutral interstellar material that is singly ionized near the Sun by UV or charge exchange with the solar wind, and is subsequently accelerated in the outer heliosphere.

  4. Exploring excited states of Pt(II) diimine catecholates for photoinduced charge separation.

    PubMed

    Scattergood, Paul A; Jesus, Patricia; Adams, Harry; Delor, Milan; Sazanovich, Igor V; Burrows, Hugh D; Serpa, Carlos; Weinstein, Julia A

    2015-07-14

    The intense absorption in the red part of the visible range, and the presence of a lowest charge-transfer excited state, render Platinum(II) diimine catecholates potentially promising candidates for light-driven applications. Here, we test their potential as sensitisers in dye-sensitised solar cells and apply, for the first time, the sensitive method of photoacoustic calorimetry (PAC) to determine the efficiency of electron injection in the semiconductor from a photoexcited Pt(II) complex. Pt(II) catecholates containing 2,2′-bipyridine-4,4′-di-carboxylic acid (dcbpy) have been prepared from their parent iso-propyl ester derivatives, complexes of 2,2′-bipyridine-4,4′-di-C(O)OiPr, (COOiPr)2bpy, and their photophysical and electrochemical properties studied. Modifying diimine Pt(II) catecholates with carboxylic acid functionality has allowed for the anchoring of these complexes to thin film TiO2, where steric bulk of the complexes (3,5-di(t)Bu-catechol vs. catechol) has been found to significantly influence the extent of monolayer surface coverage. Dye-sensitised solar cells using Pt(dcbpy)((t)Bu2Cat), 1a, and Pt(dcbpy)(pCat), 2a, as sensitisers, have been assembled, and photovoltaic measurements performed. The observed low, 0.02–0.07%, device efficiency of such DSSCs is attributed at least in part to the short excited state lifetime of the sensitisers, inherent to this class of complexes. The lifetime of the charge-transfer ML/LLCT excited state in Pt((COO(I)Pr)2bpy)(3,5-di-(t)Bu-catechol) was determined as 250 ps by picosecond time-resolved infrared spectroscopy, TRIR. The measured increase in device efficiency for 2a over 1a is consistent with a similar increase in the quantum yield of charge separation (where the complex acts as a donor and the semiconductor as an acceptor) determined by PAC, and is also proportional to the increased surface loading achieved with 2a. It is concluded that the relative efficiency of devices sensitised with these particular

  5. Transport of charge and atomic particles in Rydberg state-rich plasmas

    NASA Astrophysics Data System (ADS)

    Hagström, Magnus; Davidsson, Jan; Holmlid, Leif

    1998-02-01

    New methods make it possible to form considerable flux densities of Rydberg atoms of alkali metals. It is now possible to study the transport processes in regions where the density of Rydberg atoms is large. Examples of such studies have been given by Svensson and coworkers. In the present study, 0022-3727/31/4/013/img1 ions and Rydberg states 0022-3727/31/4/013/img2 are formed by desorption at 1300-1800 K from an Ir surface covered by a thin graphite layer. Due to the very large cross sections for collision processes involving Rydberg species, the Rydberg state-rich plasma between the Ir emitter and a cold grid electrode is not collision free, even at a pressure of 0022-3727/31/4/013/img3 mbar. Electron or 0022-3727/31/4/013/img4 emission takes place from the grid at a rate controlled by the flux of 0022-3727/31/4/013/img1 and 0022-3727/31/4/013/img2. The transition to penetration of 0022-3727/31/4/013/img1 and 0022-3727/31/4/013/img2 through the cloud of excited species between the emitter and grid is observed directly by molecular beam and ion sampling to detectors in a separate chamber. There is a space-charge limited behaviour for the positive current through the plasma as well as, in some modes, a clear positive saturation current, which shows that little gas phase ionization takes place. A current larger than expected from the saturation current as well as maxima in the voltage dependences are observed at high Rydberg densities. These effects are probably caused by space charge compensation due to a dielectric phase of condensed excited species, which means, for example, that the effective distance between the emitter and grid is decreased, as observed. The temperature variation of the space charge limited behaviour gives an activation energy of 0022-3727/31/4/013/img9, while the saturation current gives an activation energy of 0022-3727/31/4/013/img10. This agrees well with the electronic excitations 0022-3727/31/4/013/img11 at 0.90 eV and 0022

  6. First Use of High Charge States for Mass Measurements of Short-Lived Nuclides in a Penning Trap

    SciTech Connect

    Ettenauer, S.; Gallant, A. T.; Dilling, J.; Simon, M. C.; Chaudhuri, A.; Mane, E.; Delheij, P.; Pearson, M. R.; Brunner, T.; Chowdhury, U.; Simon, V. V.; Brodeur, M.; Andreoiu, C.; Audi, G.; Lopez-Urrutia, J. R. Crespo; Ullrich, J.; Gwinner, G.; Lapierre, A.; Lunney, D.; Ringle, R.

    2011-12-30

    Penning trap mass measurements of short-lived nuclides have been performed for the first time with highly charged ions, using the TITAN facility at TRIUMF. Compared to singly charged ions, this provides an improvement in experimental precision that scales with the charge state q. Neutron-deficient Rb isotopes have been charge bred in an electron beam ion trap to q=8-12+ prior to injection into the Penning trap. In combination with the Ramsey excitation scheme, this unique setup creating low energy, highly charged ions at a radioactive beam facility opens the door to unrivaled precision with gains of 1-2 orders of magnitude. The method is particularly suited for short-lived nuclides such as the superallowed {beta} emitter {sup 74}Rb (T{sub 1/2}=65 ms). The determination of its atomic mass and an improved Q{sub EC} value are presented.

  7. First use of high charge states for mass measurements of short-lived nuclides in a Penning trap.

    PubMed

    Ettenauer, S; Simon, M C; Gallant, A T; Brunner, T; Chowdhury, U; Simon, V V; Brodeur, M; Chaudhuri, A; Mané, E; Andreoiu, C; Audi, G; López-Urrutia, J R Crespo; Delheij, P; Gwinner, G; Lapierre, A; Lunney, D; Pearson, M R; Ringle, R; Ullrich, J; Dilling, J

    2011-12-30

    Penning trap mass measurements of short-lived nuclides have been performed for the first time with highly charged ions, using the TITAN facility at TRIUMF. Compared to singly charged ions, this provides an improvement in experimental precision that scales with the charge state q. Neutron-deficient Rb isotopes have been charge bred in an electron beam ion trap to q=8-12+ prior to injection into the Penning trap. In combination with the Ramsey excitation scheme, this unique setup creating low energy, highly charged ions at a radioactive beam facility opens the door to unrivaled precision with gains of 1-2 orders of magnitude. The method is particularly suited for short-lived nuclides such as the superallowed β emitter 74Rb (T(1/2)=65  ms). The determination of its atomic mass and an improved Q(EC) value are presented. PMID:22243307

  8. Surface-State-Dominated Spin-Charge Current Conversion in Topological-Insulator-Ferromagnetic-Insulator Heterostructures

    NASA Astrophysics Data System (ADS)

    Wang, Hailong; Kally, James; Lee, Joon Sue; Liu, Tao; Chang, Houchen; Hickey, Danielle Reifsnyder; Mkhoyan, K. Andre; Wu, Mingzhong; Richardella, Anthony; Samarth, Nitin

    2016-08-01

    We report the observation of ferromagnetic resonance-driven spin pumping signals at room temperature in three-dimensional topological insulator thin films—Bi2Se3 and (Bi,Sb ) 2Te3 —deposited by molecular beam epitaxy on Y3 Fe5 O12 thin films. By systematically varying the Bi2 Se3 film thickness, we show that the spin-charge conversion efficiency, characterized by the inverse Rashba-Edelstein effect length (λIREE ), increases dramatically as the film thickness is increased from two quintuple layers, saturating above six quintuple layers. This suggests a dominant role of surface states in spin and charge interconversion in topological-insulator-ferromagnet heterostructures. Our conclusion is further corroborated by studying a series of Y3 Fe5 O12 /(Bi,Sb ) 2Te3 heterostructures. Finally, we use the ferromagnetic resonance linewidth broadening and the inverse Rashba-Edelstein signals to determine the effective interfacial spin mixing conductance and λIREE.

  9. Acquiring impedance spectra from diode-coupled primary batteries to determine health and state of charge

    NASA Astrophysics Data System (ADS)

    Christophersen, Jon P.; Morrison, John L.; Morrison, William H.

    The U.S. Army uses BA5590 Lithium Sulfur Dioxide primary batteries for portable electronic systems. There remains a need, however, for technology that can rapidly assess these batteries and estimate their remaining state of health after being used without degrading them to determine if there is remaining useful life for additional missions. This allows the full range of charge to be consumed before the battery is recycled or disposed. Impedance spectroscopy measurements have been shown to be a useful diagnostic tool, but standard methods cannot be applied to the BA5590 batteries because of the up-front electronics. The BA5590 module is diode-coupled and a charge-neutral excitation signal would be half-wave rectified and completely corrupt the results. However, a rapid impedance spectrum measurement technique has been developed that can be used for the BA5590s based on the addition of a small discharge bias load super-imposed on the sinusoidal excitation signal. The feasibility of this approach was initially simulated and then successfully applied to cell strings on four fresh BA5590 modules. The results clearly showed consistent and repeatable impedance spectra with no significant impact on the SOC as a result of the measurement. Details of this measurement technique and discussion of the preliminary results are presented.

  10. Charge state of arginine as an additive on heat-induced protein aggregation.

    PubMed

    Miyatake, Takumi; Yoshizawa, Shunsuke; Arakawa, Tsutomu; Shiraki, Kentaro

    2016-06-01

    Arginine (Arg) is one of the most versatile solvent additives, such as suppressing protein aggregation, increasing solubility of small aromatic compounds and peptides, and preventing protein binding on solid surfaces. In this study, we investigated the role of the charged state of α-amino group of Arg for the prevention of protein aggregation. As expected, Arg effectively suppressed thermal aggregation of hen egg-white lysozyme at neutral pH, whereas the suppression effect diminished at and above pH 9.0, which corresponds to the pK of Arg's α-amino group. The pH dependence of Arg as an aggregation suppressor was confirmed by additional experiments with neutral proteins, bovine hemoglobin and bovine γ-globulin. Interestingly, N-acetylated arginine, which lacks the α-amino group, showed a weaker suppressive effect on protein aggregation than Arg, even at neutral pH. These results indicate that both positively charged α-amino group and guanidinium group play important roles in suppressing heat-induced protein aggregation by Arg. The elucidated limitation of Arg at alkaline pH provides new insight in the application as well as the mechanism of Arg as a solvent additive. PMID:26987431

  11. Utilizing Metal to Ligand Charge Transfer States of MM Quadruply Bonded Complexes for Photovoltaic Applications

    NASA Astrophysics Data System (ADS)

    Lewis, Sharlene A.; Brown-Xu, Samantha E.; Chisholm, Malcolm H.; Epstein, Arthur J.

    2013-06-01

    In this contribution, we report two examples of our efforts to develop MM quadruply bonded complexes for photovoltaic applications. In the first example, evidence, based on femtosecond transient absorption and time resolved infrared spectroscopy, is presented for photoinduced charge transfer from the Mo_{2}δ orbital of the quadruply bonded molecule trans-Mo_{2}(TiPB)_{2}BTh)_{2}, where TiPB = 2,4,6-triisopropyl benzoate and BTh = 2,2'-bithienylcarboxylate, to di-n-octyl perylene diimide and di-n-hexylheptyl perylene diimide in thin films and solutions of the mixtures. In the second example, the structural and photophysical properties of the new compounds trans-M_{2}(TiPB)_{2}(L)_{2} and trans-M_{2}(TiPB)_{2}(L')_{2}, where M=Mo or W and L and L' are triphenylamine-cyanoacrylate ligands are presented. These ligands promote intense metal to ligand charge transfer transitions that span the range 550 to 1100 nm. The excited states have been studied by transient absorption and time resolved infrared spectroscopy

  12. Controlling DNA Translocation Speed through Solid-State Nanopores by Surface Charge Modulation

    NASA Astrophysics Data System (ADS)

    Meller, Amit

    2013-03-01

    The Nanopore method is an emerging technique, which extends gel-electrophoresis to the single-molecule level and allows the analysis of DNAs, RNAs and DNA-protein complexes. The strength of the technique stems from two fundamental facts: First, nanopores due to their nanoscale size can be used to uncoil biopolymers, such as DNA or RNA and slide them in a single file manner that allows scanning their properties. Consequently, the method can be used to probe short as well as extremely long biopolymers, such as genomic DNA with high efficiency. Second, electrostatic focusing of charged biopolymers into the nanopore overcomes thermally driven diffusion, thus facilitating an extremely efficient end-threading (or capture) of DNA. Thus, nanopores can be used to detect minute DNA copy numbers, circumventing costly molecular amplification such as Polymerase Chain Reaction. A critical factor, which determines the ability of nanopore to distinguish fine properties within biopolymers, such as the location of bound small-molecules, proteins, or even the nucleic acid's sequence, is the speed at which molecules are translocated through the pore. When the translocation speed is too high the electrical noise masks the desired signal, thus limiting the utility of the method. Here I will discuss new experimental results showing that modulating the surface charge inside the pore can effectively reduce the translocation speed through solid-state nanopores fabricated in thin silicon nitride membranes. I will present a simple physical model to account for these results.

  13. Gap state charge induced spin-dependent negative differential resistance in tunnel junctions

    NASA Astrophysics Data System (ADS)

    Jiang, Jun; Zhang, X.-G.; Han, X. F.

    2016-04-01

    We propose and demonstrate through first-principles calculation a new spin-dependent negative differential resistance (NDR) mechanism in magnetic tunnel junctions (MTJ) with cubic cation disordered crystals (CCDC) AlO x or Mg1‑x Al x O as barrier materials. The CCDC is a class of insulators whose band gap can be changed by cation doping. The gap becomes arched in an ultrathin layer due to the space charge formed from metal-induced gap states. With an appropriate combination of an arched gap and a bias voltage, NDR can be produced in either spin channel. This mechanism is applicable to 2D and 3D ultrathin junctions with a sufficiently small band gap that forms a large space charge. It provides a new way of controlling the spin-dependent transport in spintronic devices by an electric field. A generalized Simmons formula for tunneling current through junction with an arched gap is derived to show the general conditions under which ultrathin junctions may exhibit NDR.

  14. Surface-State-Dominated Spin-Charge Current Conversion in Topological-Insulator-Ferromagnetic-Insulator Heterostructures.

    PubMed

    Wang, Hailong; Kally, James; Lee, Joon Sue; Liu, Tao; Chang, Houchen; Hickey, Danielle Reifsnyder; Mkhoyan, K Andre; Wu, Mingzhong; Richardella, Anthony; Samarth, Nitin

    2016-08-12

    We report the observation of ferromagnetic resonance-driven spin pumping signals at room temperature in three-dimensional topological insulator thin films-Bi_{2}Se_{3} and (Bi,Sb)_{2}Te_{3}-deposited by molecular beam epitaxy on Y_{3}Fe_{5}O_{12} thin films. By systematically varying the Bi_{2}Se_{3} film thickness, we show that the spin-charge conversion efficiency, characterized by the inverse Rashba-Edelstein effect length (λ_{IREE}), increases dramatically as the film thickness is increased from two quintuple layers, saturating above six quintuple layers. This suggests a dominant role of surface states in spin and charge interconversion in topological-insulator-ferromagnet heterostructures. Our conclusion is further corroborated by studying a series of Y_{3}Fe_{5}O_{12}/(Bi,Sb)_{2}Te_{3} heterostructures. Finally, we use the ferromagnetic resonance linewidth broadening and the inverse Rashba-Edelstein signals to determine the effective interfacial spin mixing conductance and λ_{IREE}. PMID:27563980

  15. Benefits of partial-state-of-charge operation in remote-area power-supply systems

    NASA Astrophysics Data System (ADS)

    Newnham, R. H.; Baldsing, W. G. A.

    Many people throughout the world are remote from electricity networks and do not have access to reliable power. Remote-area power-supply (RAPS) systems offer a reliable and cost-effective alternative to grid connection. Achieving adequate performance from such systems requires appropriate componentry and well-designed control systems/strategies. A relatively new operating methodology—known as partial-state-of-charge (PSoC) operation—is now finding application in the field. The strategy, which can give a three-fold increase in the lifetime energy-delivery of gelled-electrolyte batteries compared with that obtained using traditional charging procedures, is to be employed in RAPS systems in Peru. The PSoC algorithms will be formulated and trailed in the laboratory, and then installed in the Peru facilities where they will be monitored and controlled remotely via a satellite link-up. This approach allows the algorithms to be fine-tuned in situ, and will ensure that system efficiency and battery lifetime are maximised. Use of the PSoC concept is expected to provide a battery lifetime of 8 years.

  16. Absolute rates of hole transfer in DNA.

    PubMed

    Senthilkumar, Kittusamy; Grozema, Ferdinand C; Guerra, Célia Fonseca; Bickelhaupt, F Matthias; Lewis, Frederick D; Berlin, Yuri A; Ratner, Mark A; Siebbeles, Laurens D A

    2005-10-26

    Absolute rates of hole transfer between guanine nucleobases separated by one or two A:T base pairs in stilbenedicarboxamide-linked DNA hairpins were obtained by improved kinetic analysis of experimental data. The charge-transfer rates in four different DNA sequences were calculated using a density-functional-based tight-binding model and a semiclassical superexchange model. Site energies and charge-transfer integrals were calculated directly as the diagonal and off-diagonal matrix elements of the Kohn-Sham Hamiltonian, respectively, for all possible combinations of nucleobases. Taking into account the Coulomb interaction between the negative charge on the stilbenedicarboxamide linker and the hole on the DNA strand as well as effects of base pair twisting, the relative order of the experimental rates for hole transfer in different hairpins could be reproduced by tight-binding calculations. To reproduce quantitatively the absolute values of the measured rate constants, the effect of the reorganization energy was taken into account within the semiclassical superexchange model for charge transfer. The experimental rates could be reproduced with reorganization energies near 1 eV. The quantum chemical data obtained were used to discuss charge carrier mobility and hole-transport equilibria in DNA. PMID:16231945

  17. Do fluorescence and transient absorption probe the same intramolecular charge transfer state of 4-(dimethylamino)benzonitrile?

    SciTech Connect

    Gustavsson, Thomas; Fujiwara, Takashige; Lim, Edward C.

    2009-07-21

    We present here the results of time-resolved absorption and emission experiments for 4-(dimethylamino)benzonitrile in solution, which suggest that the fluorescent intramolecular charge transfer (ICT) state may differ from the twisted ICT (TICT) state observed in transient absorption.

  18. State Educational Support, Student Enrollment, and Tuition Charges in Kentucky Public Higher Education, 1971-1980: A Decade of Changes.

    ERIC Educational Resources Information Center

    Dean, Robert L.

    State educational support, full-time-equivalent (FTE) enrollments, and tuition charges at the public colleges and universities in Kentucky from 1971 to 1980 were studied, using a comparative indexing technique. Financial data are presented in actual and indexed values, and are shown in both current and constant dollars. State educational support…

  19. Observations of energetic oxygen and carbon ions with charge states between 3 and 6 in the magnetosphere

    NASA Technical Reports Server (NTRS)

    Kremser, G.; Stuedemann, W.; Wilken, B.; Gloeckler, G.; Hamilton, D. C.

    1988-01-01

    Data obtained by the AMPTE/CCE charge-energy-mass spectrometer are used to study the average spatial distributions of oxygen and carbon ions with charge states between 3 and 6. The O(6+) and C(6+) ion fluxes are found to increase with the drift shell parameter L up to a constant level at L of not less than 7. It is suggested that the diurnal variations noted are related to the shape of the L profiles. The results support a model in which the solar wind origin O(6+) and C(6+) ions and the terrestrial origin O(+) and O(2+) ions are transported from the tail towards the earth. Charge exchange processes near the earth produce the oxygen and carbon ions with charge states between 3 and 5.

  20. Projectile charge state effects on electron emission in transfer ionization processes

    NASA Astrophysics Data System (ADS)

    Zhang, R. T.; Zhu, X. L.; Feng, W. T.; Guo, D. L.; Gao, Y.; Qian, D. B.; Li, B.; Yan, S. C.; Xu, S.; Zhang, P.; Ma, X.

    2015-07-01

    Electron emissions in transfer ionization processes were studied for 75 keV u-1 He2+, and 80 keV u-1 Ne8+on He collisions, using the well-developed reaction microscope techniques. Momentum distributions in the scattering plane, doubly differential distributions as a function of longitudinal momentum and emission angles of the ejected electrons were obtained. An apparent enhancement of electrons distributed around the projectile in the scattering plane was found for the Ne8+ incident case. Furthermore, we report the ratio of doubly differential distributions at the emission angle of 0° between these two transfer ionization processes, in which an abrupt rise is found at and above the electron capture to the continuum peak. This rise qualitatively agrees with the prediction within the framework of Dettmann’s theory. We conclude that this kind of enhancement was caused by the charge state effect of the projectile.

  1. Effect of Surface Defect States on Valence Band and Charge Separation and Transfer Efficiency.

    PubMed

    Xu, Juan; Teng, Yiran; Teng, Fei

    2016-01-01

    Both energy band and charge separation and transfer are the crucial affecting factor for a photochemical reaction. Herein, the BiOCl nanosheets without and with surface bismuth vacancy (BOC, V-BOC) are prepared by a simple hydrothermal method. It is found that the new surface defect states caused by bismuth vacancy have greatly up-shifted the valence band and efficiently enhanced the separation and transfer rates of photogenerated electron and hole. It is amazing that the photocatalytic activity of V-BOC is 13.6 times higher than that of BOC for the degradation methyl orange (MO). We can develop an efficient photocatalyst by the introduction of defects. PMID:27586149

  2. Charge state breeding for the acceleration of radioactive ions at TRIUMF

    SciTech Connect

    Ames, F.; Baartman, R.; Bricault, P.; Jayamanna, K.; McDonald, M.; Lamy, T.

    2010-02-15

    A 14.5 GHz electron cyclotron resonance ion source (PHOENIX from Pantechnik) has been set up at the Isotope Separation and ACceleration (ISAC) facility at TRIUMF for the charge state breeding of radioactive ions. After extensive testing and optimization on a test bench it has been moved on-line and put into operation. During a first test in 2008 a beam of {sup 80}Rb{sup 14+} was successfully created from {sup 80}Rb{sup 1+} and accelerated by the ISAC postaccelerator. Further tests with different stable and radioactive isotopes from the ISAC on-line sources and from a test source with stable Cs have been carried out. Until now an efficiency of 1.4% for {sup 124}Cs{sup 20+} has been obtained.

  3. Confinement physics for thermal, neutral, high-charge-state plasmas in nested-well solenoidal traps.

    PubMed

    Dolliver, D D; Ordonez, C A

    1999-06-01

    A theoretical study is presented which indicates that it is possible to confine a neutral plasma using static electric and solenoidal magnetic fields. The plasma consists of equal temperature electrons and highly stripped ions. The solenoidal magnetic field provides radial confinement, while the electric field, which produces an axial nested-well potential profile, provides axial confinement. A self-consistent, multidimensional numerical solution for the electric potential is obtained, and a fully kinetic theoretical treatment on axial transport is used to determine an axial confinement time scale. The effect on confinement of the presence of a radial electric field is explored with the use of ion trajectory calculations. A thermal, neutral, high-charge-state plasma confined in a nested-well trap opens new possibilities for fundamental studies on plasma recombination and cross-field transport processes under highly controlled conditions. PMID:11969700

  4. Charge state breeding for the acceleration of radioactive ions at TRIUMFa)

    NASA Astrophysics Data System (ADS)

    Ames, F.; Baartman, R.; Bricault, P.; Jayamanna, K.; Lamy, T.; McDonald, M.

    2010-02-01

    A 14.5 GHz electron cyclotron resonance ion source (PHOENIX from Pantechnik) has been set up at the Isotope Separation and ACceleration (ISAC) facility at TRIUMF for the charge state breeding of radioactive ions. After extensive testing and optimization on a test bench it has been moved on-line and put into operation. During a first test in 2008 a beam of R80b14+ was successfully created from R80b1+ and accelerated by the ISAC postaccelerator. Further tests with different stable and radioactive isotopes from the ISAC on-line sources and from a test source with stable Cs have been carried out. Until now an efficiency of 1.4% for C124s20+ has been obtained.

  5. Lead-acid batteries for partial-state-of-charge applications

    NASA Astrophysics Data System (ADS)

    Hariprakash, B.; Gaffoor, S. A.; Shukla, A. K.

    2 V/40 Ah valve-regulated lead-acid (VRLA) cells have been constructed with negative plates employing carbon black as well as an admixture of carbon black + fumed silica as additives in negative active material for partial-state-of-charge (PSoC) applications. Electrical performance of such cells is compared with conventional 2 V/40 Ah VRLA cells for PSoC operation. Active material utilization has been found to be higher for carbon-black + fumed-silica mixed negative plates while formation is faster for cells with carbon-black mixed negative plates. Both faradaic efficiency and percentage capacity delivered have been found to be higher for cells with carbon-black + fumed-silica mixed negative plates. However, a high self-discharge rate is observed for cells with carbon-black + fumed-silica mixed negative plates.

  6. Effect of Surface Defect States on Valence Band and Charge Separation and Transfer Efficiency

    PubMed Central

    Xu, Juan; Teng, Yiran; Teng, Fei

    2016-01-01

    Both energy band and charge separation and transfer are the crucial affecting factor for a photochemical reaction. Herein, the BiOCl nanosheets without and with surface bismuth vacancy (BOC, V-BOC) are prepared by a simple hydrothermal method. It is found that the new surface defect states caused by bismuth vacancy have greatly up-shifted the valence band and efficiently enhanced the separation and transfer rates of photogenerated electron and hole. It is amazing that the photocatalytic activity of V-BOC is 13.6 times higher than that of BOC for the degradation methyl orange (MO). We can develop an efficient photocatalyst by the introduction of defects. PMID:27586149

  7. Scaling for state-selective charge exchange due to collisions of multicharged ions with hydrogen

    NASA Astrophysics Data System (ADS)

    Jorge, A.; Illescas, Clara; Miraglia, J. E.; Gravielle, M. S.

    2015-12-01

    In this article we evaluate state-resolved charge exchange cross sections for Be{}4+, {{{B}}}5+, {{{C}}}6+, {{{N}}}7+, and {{{O}}}8+ projectiles colliding with atomic hydrogen employing two different methods: the classical trajectory Monte Carlo and the eikonal impulse approximations. These cross sections are used to extend previously derived scaling laws for n-, nl-, and nlm-distributions to highly excited final levels with 4≤slant n≤slant 9, covering energies in the range 50-2000 {{keV}}/ amu. Present total and partial capture cross sections are in agreement with available experimental and theoretical data for these collision systems. Besides, the proposed scaling rules are also verified by other theories, becoming a useful instrument for plasma research.

  8. Scaling for state-selective charge exchange due to collisions of multicharged ions with hydrogen

    NASA Astrophysics Data System (ADS)

    Jorge, A.; Illescas, Clara; Miraglia, J. E.; Gravielle, M. S.

    2014-12-01

    In this article we evaluate state-resolved charge exchange cross sections for Be{}4+, {{{B}}}5+, {{{C}}}6+, {{{N}}}7+, and {{{O}}}8+ projectiles colliding with atomic hydrogen employing two different methods: the classical trajectory Monte Carlo and the eikonal impulse approximations. These cross sections are used to extend previously derived scaling laws for n-, nl-, and nlm-distributions to highly excited final levels with 4≤slant n≤slant 9, covering energies in the range 50-2000 {{keV}}/ amu. Present total and partial capture cross sections are in agreement with available experimental and theoretical data for these collision systems. Besides, the proposed scaling rules are also verified by other theories, becoming a useful instrument for plasma research.

  9. Investigation of ground state charge transfer complex between paracetamol and p-chloranil through DFT and UV-visible studies

    NASA Astrophysics Data System (ADS)

    Shukla, Madhulata; Srivastava, Nitin; Saha, Satyen

    2012-08-01

    The present report deals with the theoretical investigation on ground state structure and charge transfer (CT) transitions in paracetamol (PA)/p-chloranil (CA) complex using Density Functional Theory (DFT) and Time Dependent Density Functional Theory (TD-DFT) method. It is found that Cdbnd O bond length of p-chloranil increases on complexation with paracetamol along with considerable amount of charge transfer from PA to CA. TD-DFT calculations have been performed to analyse the observed UV-visible spectrum of PA-CA charge transferred complex. Interestingly, in addition to expected CT transition, a weak symmetry relieved π-π* transition in the chloranil is also observed.

  10. Charge-state dependence of binary-encounter-electron cross sections and peak energies

    NASA Astrophysics Data System (ADS)

    Hidmi, H. I.; Richard, P.; Sanders, J. M.; Schöne, H.; Giese, J. P.; Lee, D. H.; Zouros, T. J. M.; Varghese, S. L.

    1993-12-01

    The charge-state dependence of the binary-encounter-electron (BEE) double-differential cross section (DDCS) at 0° with respect to the beam direction resulting from collisions of 1 MeV/amu H+, Cq+, Nq+, Oq+, Fq+, Siq+, and Clq+, and 0.5 MeV/amu Cuq+ with H2 is reported. The data show an enhancement in the BEE DDCS as the charge state of the projectile is decreased, in agreement with the data reported by Richard et al. [J. Phys. B 23, L213 (1990)]. The DDCS enhancement ratios observed for the three-electron isoelectronic sequence C3+:C6+, N4+:N7+, O5+:O8+, and F6+:F9+ are about 1.35, whereas a DDCS enhancement of 3.5 was observed for Cu4+. The BEE enhancement with increasing electrons on the projectile has been shown by several authors to be due to the non-Coulomb static potential of the projectile and additionally to the e-e exchange interaction. An impulse-approximation (IA) model fits the shape of the BEE DDCS and predicts a Z2p dependence for the bare-ion cross sections. The IA also predicts a binary peak energy that is independent of q and Zp and below the classical value of 4t, where t is the energy of electrons traveling with the projectile velocity. We observed a BEE energy shift ΔE (ΔE=4t-Epeak, where Epeak is the measured energy at the peak of the binary encounter electrons) that is approximately independent of q for the low-Zp ions, whereas the measured ΔE values for Si, Cl, and Cu were found to be q dependent.

  11. Multi-band reflectance spectroscopy of carbonaceous lithium iron phosphate battery electrodes versus state of charge

    NASA Astrophysics Data System (ADS)

    Norris, R.; Iyer, K.; Chabot, V.; Nieva, P.; Yu, A.; Khajepour, A.; Wang, J.

    2014-03-01

    This study aims to expand the body of knowledge about the optical properties of battery cathode materials. Although some studies have been conducted on the optical properties of Lithium Iron Phosphate (LiFePO4), to the authors' knowledge, this is the first study of its kind on electrodes extracted from commercially available LiFePO4 batteries. The use of Vis/NIR and FTIR spectroscopy provides for a methodology to study the optical properties of LiFePO4 and may allow for the characterization of other properties such as particle size and the proportions of LiFePO4 versus FePO4 material. Knowledge of these properties is important for the development of a mechanism to measure the state-of charge (SOC) in lithium ion batteries. These properties are also important in a host of other applications including battery modeling and materials characterization. Cylindrical LiFePO4 batteries (from A123 Systems Inc.) were acquired from the commercial market and charged to 10 different states between 30% and 80% of their nominal capacity using a constant-current, constant-voltage (CCCV) cycling method. Visual inspection of the extracted electrodes shows that the LiFePO4/C-cathodes display subtle changes in color (shades of grey) with respect to SOC. Vis/NIR measurements support the visual observation of uniform intensity variations versus SOC. FTIR measurements show an absorbance signature that varies with SOC and is distinct from results found in the literature for similar LiFePO4-based material systems, supporting the uniqueness of the absorbance fingerprint.

  12. Valence states and possible charge ordering in LaCo(1-x)Rh(x)O₃.

    PubMed

    Streltsov, Sergey V; Gapontsev, Vladimir V; Khomskii, Daniel I

    2016-03-01

    An unusual effect was discovered in Li et al (2010 J. Solid State Chem. 183 1388): the substitution of nonmagnetic low-spin Co(3+) in LaCoO3 by the formally isoelectronic and also nonmagnetic Rh(3+) led, surprisingly, to a rapid appearance of magnetism in LaCo(1-x)Rh(x)O3, even for small amounts of doping. Different explanations for this effect were proposed in the literature. To clarify the situation we carried out unbiased ab initio calculations of this system. We concluded that, in agreement with the original assumption of Li et al, but in contrast with later statements (Knizek et al 2012 Phys. Rev. B 85 134401), this effect is caused by the valence change ('redox reaction') Co(3+) +  Rh(3+) → Co(2+) +  Rh(4+), which creates magnetic Co(2+) and Rh(4+) ions. For the half-filled case LaCo1/2Rh1/2O3 we obtained the state with charge ordering of Co(2+) and Rh(4+) ions, which according to our calculations are antiferromagnetically coupled. The obtained results reasonably explain the observed behavior of the magnetic susceptibility of LaCo(1-x)Rh(x)O3, and the novel state predicted at half-doping could be verified experimentally by detailed structural and magnetic studies and by x-ray absorption spectroscopy. PMID:26852883

  13. A new method of modeling and state of charge estimation of the battery

    NASA Astrophysics Data System (ADS)

    Liu, Congzhi; Liu, Weiqun; Wang, Lingyan; Hu, Guangdi; Ma, Luping; Ren, Bingyu

    2016-07-01

    Accurately estimating the State of Charge (SOC) of the battery is the basis of Battery Management System (BMS). This paper has introduced a new modeling and state estimation method for the lithium battery system, which utilizes the fractional order theories. Firstly, a fractional order model based on the PNGV (Partnership for a New Generation of Vehicle) model is proposed after analyzing the impedance characteristics of the lithium battery and compared with the integer order model. With the observability of the discrete non-linear model of the battery confirmed, the method of the state observer based on the extended fractional Kalman filter (EFKF) and the least square identification method of battery parameters are studied. Then, it has been applied successfully to estimate the battery SOC using the measured battery current and voltage. Finally, a standard HPPC (Hybrid Pulse Power Characteristic) test is used for parameter identification and several experimental validations are investigated on a ternary manganese-nickel-cobalt lithium battery pack with a nominal capacity of 24 Ah which consists of ten Sony commercial cells (US18650GR G7) in parallels. The results demonstrate the effectiveness of the fractional order model and the estimation method.

  14. Valence states and possible charge ordering in LaCo1-x Rh x O3

    NASA Astrophysics Data System (ADS)

    Streltsov, Sergey V.; Gapontsev, Vladimir V.; Khomskii, Daniel I.

    2016-03-01

    An unusual effect was discovered in Li et al (2010 J. Solid State Chem. 183 1388): the substitution of nonmagnetic low-spin Co3+ in LaCoO3 by the formally isoelectronic and also nonmagnetic Rh3+ led, surprisingly, to a rapid appearance of magnetism in LaCo1-x Rh x O3, even for small amounts of doping. Different explanations for this effect were proposed in the literature. To clarify the situation we carried out unbiased ab initio calculations of this system. We concluded that, in agreement with the original assumption of Li et al, but in contrast with later statements (Knizek et al 2012 Phys. Rev. B 85 134401), this effect is caused by the valence change (’redox reaction’) Co3+   +  Rh3+ \\to Co2+   +  Rh4+ , which creates magnetic Co2+ and Rh4+ ions. For the half-filled case LaCo1/2Rh1/2O3 we obtained the state with charge ordering of Co2+ and Rh4+ ions, which according to our calculations are antiferromagnetically coupled. The obtained results reasonably explain the observed behavior of the magnetic susceptibility of LaCo1-x Rh x O3, and the novel state predicted at half-doping could be verified experimentally by detailed structural and magnetic studies and by x-ray absorption spectroscopy.

  15. Coherence, Energy and Charge Transfers in De-Excitation Pathways of Electronic Excited State of Biomolecules in Photosynthesis

    NASA Astrophysics Data System (ADS)

    Bohr, Henrik G.; Malik, F. Bary

    2013-11-01

    The observed multiple de-excitation pathways of photo-absorbed electronic excited state in the peridinin-chlorophyll complex, involving both energy and charge transfers among its constituents, are analyzed using the bio-Auger (B-A) theory. It is also shown that the usually used Förster-Dexter theory, which does not allow for charge transfer, is a special case of B-A theory. The latter could, under appropriate circumstances, lead to excimers.

  16. Equilibrium charge state distributions of Ni, Co, and Cu beams in molybdenum foil at 2 MeV/u

    NASA Astrophysics Data System (ADS)

    Gastis, Panagiotis; Perdikakis, George; Robertson, Daniel; Bauder, Will; Skulski, Michael; Collon, Phillipe; Anderson, Tyler; Ostdiek, Karen; Aprahamian, Ani; Lu, Wenting; Almus, Robert

    2015-10-01

    The charge states of heavy-ions are important for the study of nuclear reactions in inverse kinematics when electromagnetic recoil mass spectrometers are used. The passage of recoil products through a material, like the windows of gas cells or charge state boosters, results a charge state distribution (CSD) in the exit. This distribution must be known for the extraction of any cross section since only few charge-state can be transmitted through a magnetic separator separator for a given setting. The calculation of CSDs for heavy ions is challenging. Currently we rely on semi-empirical models with unknown accuracy for ion/target combinations in the Z > 20 region. In the present study were measured the CSDs of the stable 60Ni, 59Co, and 63Cu beams while passing through a 1 μm molybdenum foil. The beam energies were 1.84 MeV/u, 2.09 MeV/u, and 2.11 MeV/u for the 60Ni, 59Co, and 63Cu respectively. The results of this study mainly check the accuracy of the semi-empirical models used by the program LISE++, on calculating CSDs for ion/target combinations of Z > 20. In addition, other empirical models on calculating mean charge states were compared and checked.

  17. Open-State Occupancy Prevents Gating Charge Relaxation of N-type (CaV2.2) Calcium Channels

    PubMed Central

    Yarotskyy, Viktor; Elmslie, Keith S.

    2009-01-01

    N-type and L-type channels have significant gating differences, and we wondered whether some of these differences are linked to the relationship between charge movement and channel opening. The time constants for N-channel closing (τDeact) and Off-gating charge movement (τQOff) were compared over a range of voltages. τQOff was significantly larger than τDeact at voltages < −10 mV, and the voltage dependence of the τQOff was less steep than that for τDeact, which suggests that gating charge relaxation does not limit channel closing. Roscovitine, a drug that slows N-channel closing by holding the channel in a high open-probability state, was found to slow both τQOff and τDeact, and thus the time courses of channel closing and gating charge relaxation were similar. Our gating current results were reproduced with the addition of a voltage-independent, closed-closed transition to our previously published two-open-state N-channel model. This work suggests that, like L-type channels, there is a voltage-independent transition along the N-channel activation/deactivation pathway, but this transition occurs between closed states instead of the closed-open states of the L-channel. Also unlike L-type channels, the gating charge appears to be locked into the activated position by the N-channel open state. PMID:19883587

  18. Tracking the charge and spin dynamics of electronic excited states in inorganic complexes

    NASA Astrophysics Data System (ADS)

    Gaffney, Kelly

    2015-03-01

    Inorganic complexes have many advantageous properties for solar energy applications, including strong visible absorption and photocatalytic activity. Whether used as a photocatalyst or a photosensitizer, the lifetime of electronic excited states and the earth abundance of the molecular components represent a key property for solar energy applications. These dual needs have undermined the usefulness of many coordination compounds. Isoelectronic iron and ruthenium based complexes represent a clear example. Ru-polypyridal based molecules have been the workhorse of solar energy related research and dye sensitized solar cells for decades, but the replacement of low abundance Ru with Fe leads to million-fold reductions in metal to ligand charge transfer (MLCT) excited state lifetimes. Understanding the origin of this million-fold reduction in lifetime and how to control excited state relaxation in 3d-metal complexes motivates the work I will discuss. We have used the spin sensitivity of hard x-ray fluorescence spectroscopy and the intense femtosecond duration pulses generated by the LCLS x-ray laser to probe the spin dynamics in a series of electronically excited [Fe(CN)6-2N(2,2'-bipyridine)N]2 N - 4 complexes, with N = 1-3. These femtosecond resolution measurements demonstrate that modification of the solvent and ligand environment can lengthen the MLCT excited state lifetime by more than two orders of magnitude. They also verify the role of triplet ligand field excited states in the spin crossover dynamics from singlet to quintet spin configurations. Work supported by the AMOS program within the Chemical Sciences, Geosciences, and Biosciences Division of the Office of Basic Energy Sciences, Office of Science, U.S. Department of Energy.

  19. Gating Charge Immobilization in Kv4.2 Channels: The Basis of Closed-State Inactivation

    PubMed Central

    Dougherty, Kevin; De Santiago-Castillo, Jose A.; Covarrubias, Manuel

    2008-01-01

    Kv4 channels mediate the somatodendritic A-type K+ current (ISA) in neurons. The availability of functional Kv4 channels is dynamically regulated by the membrane potential such that subthreshold depolarizations render Kv4 channels unavailable. The underlying process involves inactivation from closed states along the main activation pathway. Although classical inactivation mechanisms such as N- and P/C-type inactivation have been excluded, a clear understanding of closed-state inactivation in Kv4 channels has remained elusive. This is in part due to the lack of crucial information about the interactions between gating charge (Q) movement, activation, and inactivation. To overcome this limitation, we engineered a charybdotoxin (CTX)-sensitive Kv4.2 channel, which enabled us to obtain the first measurements of Kv4.2 gating currents after blocking K+ conduction with CTX (Dougherty and Covarrubias. 2006J. Gen. Physiol. 128:745–753). Here, we exploited this approach further to investigate the mechanism that links closed-state inactivation to slow Q-immobilization in Kv4 channels. The main observations revealed profound Q-immobilization at steady-state over a range of hyperpolarized voltages (−110 to −75 mV). Depolarization in this range moves <5% of the observable Q associated with activation and is insufficient to open the channels significantly. The kinetics and voltage dependence of Q-immobilization and ionic current inactivation between −153 and −47 mV are similar and independent of the channel's proximal N-terminal region (residues 2–40). A coupled state diagram of closed-state inactivation with a quasi-absorbing inactivated state explained the results from ionic and gating current experiments globally. We conclude that Q-immobilization and closed-state inactivation at hyperpolarized voltages are two manifestations of the same process in Kv4.2 channels, and propose that inactivation in the absence of N- and P/C-type mechanisms involves desensitization to

  20. Electronic Absolute Cartesian Autocollimator

    NASA Technical Reports Server (NTRS)

    Leviton, Douglas B.

    2006-01-01

    An electronic absolute Cartesian autocollimator performs the same basic optical function as does a conventional all-optical or a conventional electronic autocollimator but differs in the nature of its optical target and the manner in which the position of the image of the target is measured. The term absolute in the name of this apparatus reflects the nature of the position measurement, which, unlike in a conventional electronic autocollimator, is based absolutely on the position of the image rather than on an assumed proportionality between the position and the levels of processed analog electronic signals. The term Cartesian in the name of this apparatus reflects the nature of its optical target. Figure 1 depicts the electronic functional blocks of an electronic absolute Cartesian autocollimator along with its basic optical layout, which is the same as that of a conventional autocollimator. Referring first to the optical layout and functions only, this or any autocollimator is used to measure the compound angular deviation of a flat datum mirror with respect to the optical axis of the autocollimator itself. The optical components include an illuminated target, a beam splitter, an objective or collimating lens, and a viewer or detector (described in more detail below) at a viewing plane. The target and the viewing planes are focal planes of the lens. Target light reflected by the datum mirror is imaged on the viewing plane at unit magnification by the collimating lens. If the normal to the datum mirror is parallel to the optical axis of the autocollimator, then the target image is centered on the viewing plane. Any angular deviation of the normal from the optical axis manifests itself as a lateral displacement of the target image from the center. The magnitude of the displacement is proportional to the focal length and to the magnitude (assumed to be small) of the angular deviation. The direction of the displacement is perpendicular to the axis about which the

  1. Nanoscale manipulation of the Mott insulating state coupled to charge order in 1T-TaS2

    NASA Astrophysics Data System (ADS)

    Cho, Doohee; Cheon, Sangmo; Kim, Ki-Seok; Lee, Sung-Hoon; Cho, Yong-Heum; Cheong, Sang-Wook; Yeom, Han Woong

    2016-01-01

    The controllability over strongly correlated electronic states promises unique electronic devices. A recent example is an optically induced ultrafast switching device based on the transition between the correlated Mott insulating state and a metallic state of a transition metal dichalcogenide 1T-TaS2. However, the electronic switching has been challenging and the nature of the transition has been veiled. Here we demonstrate the nanoscale electronic manipulation of the Mott state of 1T-TaS2. The voltage pulse from a scanning tunnelling microscope switches the insulating phase locally into a metallic phase with irregularly textured domain walls in the charge density wave order inherent to this Mott state. The metallic state is revealed as a correlated phase, which is induced by the moderate reduction of electron correlation due to the charge density wave decoherence.

  2. Nanoscale manipulation of the Mott insulating state coupled to charge order in 1T-TaS2

    PubMed Central

    Cho, Doohee; Cheon, Sangmo; Kim, Ki-Seok; Lee, Sung-Hoon; Cho, Yong-Heum; Cheong, Sang-Wook; Yeom, Han Woong

    2016-01-01

    The controllability over strongly correlated electronic states promises unique electronic devices. A recent example is an optically induced ultrafast switching device based on the transition between the correlated Mott insulating state and a metallic state of a transition metal dichalcogenide 1T-TaS2. However, the electronic switching has been challenging and the nature of the transition has been veiled. Here we demonstrate the nanoscale electronic manipulation of the Mott state of 1T-TaS2. The voltage pulse from a scanning tunnelling microscope switches the insulating phase locally into a metallic phase with irregularly textured domain walls in the charge density wave order inherent to this Mott state. The metallic state is revealed as a correlated phase, which is induced by the moderate reduction of electron correlation due to the charge density wave decoherence. PMID:26795073

  3. Absolute number density calibration of the absorption by ground-state lead atoms of the 283. 3-nm resonance line from a high-intensity lead hollow cathode lamp and the calculated effect of argon pressures

    SciTech Connect

    Simons, J.W.; McClean, R.E. ); Oldenborg, R.C. )

    1991-03-21

    The absolute number density calibration for the absorption by ground-state lead atoms of the 283.3-nm resonance line from a high-intensity lead hollow cathode lamp (Photron superlamp) is determined and found to be the same as that of a standard hollow cathode lamp. Comparisons of the calibrations to theoretical calculations are found to be quite satisfactory. The effects of argon pressures in the absorption cell on the calibration are examined theoretically by using a simple Lorentzian broadening and shifting model. These calculations show the expected reduction in sensitivity and increasing linearity of Beer-Lambert plots with increasing argon pressure.

  4. Valence state parameters of all transition metal atoms in metalloproteins--development of ABEEMσπ fluctuating charge force field.

    PubMed

    Yang, Zhong-Zhi; Wang, Jian-Jiang; Zhao, Dong-Xia

    2014-09-01

    To promote accuracy of the atom-bond electronegativity equalization method (ABEEMσπ) fluctuating charge polarizable force fields, and extend it to include all transition metal atoms, a new parameter, the reference charge is set up in the expression of the total energy potential function. We select over 700 model molecules most of which model metalloprotein molecules that come from Protein Data Bank. We set reference charges for different apparent valence states of transition metals and calibrate the parameters of reference charges, valence state electronegativities, and valence state hardnesses for ABEEMσπ through linear regression and least square method. These parameters can be used to calculate charge distributions of metalloproteins containing transition metal atoms (Sc-Zn, Y-Cd, and Lu-Hg). Compared the results of ABEEMσπ charge distributions with those obtained by ab initio method, the quite good linear correlations of the two kinds of charge distributions are shown. The reason why the STO-3G basis set in Mulliken population analysis for the parameter calibration is specially explained in detail. Furthermore, ABEEMσπ method can also quickly and quite accurately calculate dipole moments of molecules. Molecular dynamics optimizations of five metalloproteins as the examples show that their structures obtained by ABEEMσπ fluctuating charge polarizable force field are very close to the structures optimized by the ab initio MP2/6–311G method. This means that the ABEEMσπ/MM can now be applied to molecular dynamics simulations of systems that contain metalloproteins with good accuracy. PMID:25042901

  5. Energy of charged states in the acetanilide crystal: Trapping of charge-transfer states at vacancies as a possible mechanism for optical damage

    NASA Astrophysics Data System (ADS)

    Tsiaousis, D.; Munn, R. W.

    2004-04-01

    Calculations for the acetanilide crystal yield the effective polarizability (16.6 Å3), local electric field tensor, effective dipole moment (5.41 D), and dipole-dipole energy (-12.8 kJ/mol). Fourier-transform techniques are used to calculate the polarization energy P for a single charge in the perfect crystal (-1.16 eV); the charge-dipole energy WD is zero if the crystal carries no bulk dipole moment. Polarization energies for charge-transfer (CT) pairs combine with the Coulomb energy EC to give the screened Coulomb energy Escr; screening is nearly isotropic, with Escr≈EC/2.7. For CT pairs WD reduces to a term δWD arising from the interaction of the charge on each ion with the change in dipole moment on the other ion relative to the neutral molecule. The dipole moments calculated by density-functional theory methods with the B3LYP functional at the 6-311++G** level are 3.62 D for the neutral molecule, changing to 7.13 D and 4.38 D for the anion and cation, relative to the center of mass. Because of the large change in the anion, δWD reaches -0.9 eV and modifies the sequence of CT energies markedly from that of Escr, giving the lowest two CT pairs at -1.98 eV and -1.41 eV. The changes in P and WD near a vacancy are calculated; WD changes for the individual charges because the vacancy removes a dipole moment and modifies the crystal dielectric response, but δWD and EC do not change. A vacancy yields a positive change ΔP that scatters a charge or CT pair, but the change ΔWD can be negative and large enough to outweigh ΔP, yielding traps with depths that can exceed 150 meV for single charges and for CT pairs. Divacancies yield traps with depths nearly equal to the sum of those produced by the separate vacancies and so they can exceed 300 meV. These results are consistent with a mechanism of optical damage in which vacancies trap optically generated CT pairs that recombine and release energy; this can disrupt the lattice around the vacancy, thereby favoring

  6. ABSOLUTE POLARIMETRY AT RHIC.

    SciTech Connect

    OKADA; BRAVAR, A.; BUNCE, G.; GILL, R.; HUANG, H.; MAKDISI, Y.; NASS, A.; WOOD, J.; ZELENSKI, Z.; ET AL.

    2007-09-10

    Precise and absolute beam polarization measurements are critical for the RHIC spin physics program. Because all experimental spin-dependent results are normalized by beam polarization, the normalization uncertainty contributes directly to final physics uncertainties. We aimed to perform the beam polarization measurement to an accuracy Of {Delta}P{sub beam}/P{sub beam} < 5%. The absolute polarimeter consists of Polarized Atomic Hydrogen Gas Jet Target and left-right pairs of silicon strip detectors and was installed in the RHIC-ring in 2004. This system features proton-proton elastic scattering in the Coulomb nuclear interference (CNI) region. Precise measurements of the analyzing power A{sub N} of this process has allowed us to achieve {Delta}P{sub beam}/P{sub beam} = 4.2% in 2005 for the first long spin-physics run. In this report, we describe the entire set up and performance of the system. The procedure of beam polarization measurement and analysis results from 2004-2005 are described. Physics topics of AN in the CNI region (four-momentum transfer squared 0.001 < -t < 0.032 (GeV/c){sup 2}) are also discussed. We point out the current issues and expected optimum accuracy in 2006 and the future.

  7. Probing of Charge Transfer States at Buried Organic Interfaces with Even-Order Spectroscopy

    NASA Astrophysics Data System (ADS)

    Pandey, Ravindra; Moon, Aaron; Roberts, Sean

    Organic thin film photovoltaics (OPV) are an emerging economically competitive technology that combines manufacturing adaptability, low-cost processing and a lightweight, flexible device end-product. At junctions formed between organic electron-donating and electron-accepting materials, the abrupt change in the dielectric properties can strongly perturb the density of states of the OPV. This can substantially alter the driving force for charge transfer between these materials. Electronic Sum Frequency Generation (ESFG), owing to its inherent interfacial sensitivity, is ideally suited to probe buried interfaces. Here, we report the ESFG spectra of Copper Phthalocyanine (CuPc) films, deposited on SiO2 measured for both reflection and transmission geometries. Three peaks are observed that roughly correlate with resonances that comprise CuPc's Q-band absorption but display slight shifts and amplitude changes with respect to CuPc's bulk absorption spectrum. Experimental results are compared with calculations based on a thin film interference model that accounts for ESFG emitted from both the CuPc:Air and CuPc:SiO2 interface as well as contributions to the signal from higher order source terms from the bulk. The model reveals a difference in the density of states between the two interfaces and suggests that by combining experimental transmission and reflection data it is possible to separate bulk and interfacial contributions to ESFG spectra.

  8. X-ray absorption structural study of a reversible, photoexcited charge-transfer state

    SciTech Connect

    Chen, L.X.; Bowman, M.K.; Norris, J.R. Univ. of Chicago, IL ); Montano, P.A. )

    1993-05-19

    Electron-transfer reactions can be accompanied by significant nuclear movements. Nuclear motion appears to be especially vital to the reversible, photoinduced charge-transfer chemistry of cyclopentadienylnickel nitrosyl (C[sub 5]H[sub 5]NiNO). Although extended X-ray absorption fine structure (EXAFS) spectroscopy has recorded photoinduced changes in the ligation of myoglobins, similar X-ray studies of electron-transfer chemistry have not been reported. Here we examine reversible, photoinduced structural changes in C[sub 5]H[sub 5]NiNO by EXAFS and propose a mechanism for the electron-transfer chemistry. This work demonstrates that EXAFS can measure distance changes accompanying photoinduced electron transfer to provide new details of the geometry of photoexcited state and suggests that electron transfer occurs in the transient, optically excited states of C[sub 5]H[sub 5]NiNO and C[sub 5]H[sub 5]NiNO[sup CT] as dictated by NO movement that produces either C[sub 5]H[sub 5]NiNO[sup CT] or C[sub 5]H[sub 5]NiNO[sup GS]. 14 refs., 2 figs.

  9. Spectroscopy of middle charge state high-Z ions in the ultraviolet for plasma diagnostics

    NASA Astrophysics Data System (ADS)

    Utter, Steven Bryan

    The quest for the creation of an economically feasible thermonuclear fusion energy reactor is still active after many decades of research. Modern machines produce plasmas which are both hotter and more dense than those created 30 years ago and future devices promise to continue this trend. Paramount to this research is the capability to adequately measure certain parameters of the plasma such as temperature, density, impurity concentration and radiation loss. This dissertation reports three sets of spectroscopic measurements from intermediate charge state of high-Z ions, which have been performed at the Electron Beam Ion Rap (EBIT) facility of the Lawrence Livermore National Laboratory 1, relevant to the development of spectral plasma diagnostics and to the understanding of radiative energy loss from heavy impurity ions of today's and future fusion devices: measurements of W radiation from 40-85 Å, precision measurements along the Cu isoelectronic sequence, and UV spectroscopy of Ti-like W. The results are also compared to the best available theoretical calculations. 1This work was performed under the auspices of the United States Department of Energy by Lawrence Livermore National Laboratory under contract number W-7405-ENG-48.

  10. Fractional-order modeling and State-of-Charge estimation for ultracapacitors

    NASA Astrophysics Data System (ADS)

    Zhang, Lei; Hu, Xiaosong; Wang, Zhenpo; Sun, Fengchun; Dorrell, David G.

    2016-05-01

    Ultracapacitors (UCs) have been widely recognized as an enabling energy storage technology in various industrial applications. They hold several advantages including high power density and exceptionally long lifespan over the well-adopted battery technology. Accurate modeling and State-of-Charge (SOC) estimation of UCs are essential for reliability, resilience, and safety in UC-powered system operations. In this paper, a novel fractional-order model composed of a series resistor, a constant-phase-element (CPE), and a Walburg-like element, is proposed to emulate the UC dynamics. The Grünald-Letnikov derivative (GLD) is then employed to discretize the continuous-time fractional-order model. The model parameters are optimally extracted using genetic algorithm (GA), based on the time-domain data acquired through the Federal Urban Driving Schedule (FUDS) test. By means of this fractional-order model, a fractional Kalman filter is synthesized to recursively estimate the UC SOC. Validation results prove that the proposed fractional-order modeling and state estimation scheme is accurate and outperforms current practice based on integer-order techniques.

  11. Charge Energy Transport in Hopping Systems with Rapidly Decreasing Density of States

    NASA Astrophysics Data System (ADS)

    Mendels, Dan; Organic Electronics Group Technion Team

    2014-03-01

    An accurate description of the carrier hopping topology in the energy domain of hopping systems incorporating a rapidly decreasing density of states and the subsequent energetic position of these systems' so called effective conduction band is crucial for rationalizing and quantifying these systems' thermo-electric properties, doping related phenomena and carrier gradient effects such as the emergence of the General Einstein Relation under degenerate conditions. Additionally, as will be shown, the 'mobile' carriers propagating through the system can have excess energies reaching 0.3eV above the system quasi-Fermi energy. Hence, since these mobile carriers are most prone to reach systems interfaces and interact with oppositely charged carriers, their excess energy should be considered in determining the efficiencies of energy dependent processes such as carrier recombination and exciton dissociation. In light of the stated motivations, a comprehensive numerical and analytical study of the topology of hopping in the energetic density of such systems (i.e. the statistics regarding which energy values carriers visit most and in what manner) was implemented and the main statistical features of the hopping process that determine the position in energy of the system's effective conduction band were distilled. The obtained results also help shed light on yet to be elucidated discrepancies between predictions given by the widely employed transport energy concept and Monte Carlo simulations.

  12. Mobility of singly-charged lanthanide cations in rare gases: Theoretical assessment of the state specificity

    SciTech Connect

    Buchachenko, Alexei A.; Viehland, Larry A.

    2014-03-21

    High quality, ab initio calculations are reported for the potential energy curves governing the interactions of four singly-charged lanthanide ions (Yb{sup +}, Eu{sup +}, Lu{sup +}, and Gd{sup +}) with the rare gases (RG = He–Xe). Scalar-relativistic coupled cluster calculations are used for the first three S-state ions, but for Gd{sup +}({sup 10}D°) it is necessary to take the interaction anisotropy into account with the help of the multi-reference technique. The potential energy curves are used to determine the ion mobility and other transport properties describing the motion of the ions through the dilute RG, both as functions of the temperature, T, in the low-field limit, and at fixed T as functions of the ratio of the electrostatic field strength to the gas number density, E/N. The calculated mobilities are in good agreement with the very limited experimental data that have become available recently. The calculations show a pronounced dependence of the transport properties on the electronic configuration of the ion, as well as a significant effect of the spin-orbit coupling on the transport properties of the Gd{sup +} ion, and predict that state-specific mobilities could be detectable in Gd{sup +}–RG experiments.

  13. Measurements of charged two-particle exclusive states in photon-photon interactions

    SciTech Connect

    Johnson, R.P.

    1986-03-01

    A description is given of an experiment performed at the PEP electron-positron storage ring, using the DELCO detector, to measure the formation of charged particle pairs from interactions of pairs of virtual photons radiated from the colliding electron beams. The final states which are measured are electron-positron pairs, charged pion pairs, charged kaon pairs, and proton pairs. Electron-positron pairs are separated from other data by use of gas Cerenkov counters. The shapes of all kinematic distributions are found to agree with predictions of quantum electrodynamics. These data also are used as an accurate normalization for subtraction of the muon-pair background and for measurement of the cross sections of the three hadronic channels. Pion pairs are measured in the mass range from 0.6 to 2.0 GeV, where production of the f (1270) resonance is observed to interfere with significant continuum production. The continuum is well described by single-pion exchange, allowing a measurement of the f two-photon partial width of 3.47 +- 0.37 keV. No a priori assumption is made about the ratio of helicity amplitudes, and the phenomenological model used in fitting the data is constrained to satisfy elastic unitarity. If unitarity is not required, then the fitted partial width is a factor of 0.83 lower than the quoted value. The Q/sup 2/ dependence of the cross section is found to be consistent with predictions of the Generalized Vector Dominance Model. Kaon pairs and proton pairs are identified by time-of-flight measurements. Kaon pairs are measured in the mass range from 1.3 to 2.0 GeV, where production of the f' (1520) resonance is observed. The ratio of the f and f' two-photon partial widths is found to be consistent with SU(3) quark model predictions with a mixing angle of 28 +- 4 degrees. Twenty-three proton pairs are observed.

  14. MAPPING THE DISTRIBUTION OF ELECTRON TEMPERATURE AND Fe CHARGE STATES IN THE CORONA WITH TOTAL SOLAR ECLIPSE OBSERVATIONS

    SciTech Connect

    Habbal, S. Rifai; Morgan, H.; Scholl, I.; Druckmueller, M.; Daw, A.; Johnson, J.; Ding, A.; Arndt, M.; Esser, R.; Rusin, V.

    2010-01-10

    The inference of electron temperature from the ratio of the intensities of emission lines in the solar corona is valid only when the plasma is collisional. Once collisionless, thermodynamic ionization equilibrium no longer holds, and the inference of an electron temperature and its gradient from such measurements is no longer valid. At the heliocentric distance where the transition from a collision-dominated to a collisionless plasma occurs, the charge states of different elements are established, or frozen-in. These are the charge states which are subsequently measured in interplanetary space. We show in this study how the 2006 March 29 and 2008 August 1 eclipse observations of a number of Fe emission lines yield an empirical value for a distance, which we call R{sub t} , where the emission changes from being collisionally to radiatively dominated. R{sub t} ranges from 1.1 to 2.0 R{sub sun}, depending on the charge state and the underlying coronal density structures. Beyond that distance, the intensity of the emission reflects the distribution of the corresponding Fe ion charge states. These observations thus yield the two-dimensional distribution of electron temperature and charge state measurements in the corona for the first time. The presence of the Fe X 637.4 nm and Fe XI 789.2 nm emission in open magnetic field regions below R{sub t} , such as in coronal holes and the boundaries of streamers, and the absence of Fe XIII 1074.7 nm and Fe XIV 530.3 nm emission there indicate that the sources of the solar wind lie in regions where the electron temperature is less than 1.2 x 10{sup 6} K. Beyond R{sub t} , the extent of the Fe X [Fe{sup 9+}] and Fe XI emission [Fe{sup 10+}], in comparison with Fe XIII [Fe{sup 12+}] and Fe XIV [Fe{sup 13+}], matches the dominance of the Fe{sup 10+} charge states measured by the Solar Wind Ion Composition Spectrometer, SWICS, on Ulysses, at -43{sup 0} latitude at 4 AU, in March-April 2006, and Fe{sup 9+} and Fe{sup 10+} charge

  15. Absorption by ground-state lead atoms of the 283. 3-nm resonant line from a lead hollow cathode lamp. An absolute number density calibration

    SciTech Connect

    Simons, J.W. ); Oldenborg, R.C.; Baughcum, S.L. )

    1989-10-19

    An accurate absolute number density calibration curve for absorption by gaseous lead atoms of the 283.3-nm resonant line from a typical lead hollow cathode lamp is reported. This calibration shows the usual curvature in the Beer-Lambert plot for atomic absorption at moderate to high absorbances that is commonly attributed to self-absorption leading to line reversal in the source and/or preferential absorption at the line center when the absorber temperature is not much greater than the source Doppler temperature. A theoretical calculation utilizing a Doppler-limited Fourier transform spectrum of the 283.3-nm emission from the lamp and a tabulated value of the absorption cross section and accounting for the isotopic and nuclear hyperfine components in both the emission and absorption due to naturally occurring lead quantitatively reproduces the experimental calibration curve without any parameter adjustments. It is found that the curvature in the Beer-Lambert plot has more to do with the fact that the absorbing and emitting atoms are a mixture of isotopes giving several isotopic and nuclear hyperfine transitions at slightly different frequencies than it does with preferential absorption at line centers.

  16. Magnetospectroscopy of excited states in charge-tunable GaAs/AlGaAs [111] quantum dots

    NASA Astrophysics Data System (ADS)

    Durnev, M. V.; Vidal, M.; Bouet, L.; Amand, T.; Glazov, M. M.; Ivchenko, E. L.; Zhou, P.; Wang, G.; Mano, T.; Ha, N.; Kuroda, T.; Marie, X.; Sakoda, K.; Urbaszek, B.

    2016-06-01

    We present a combined experimental and theoretical study of highly charged and excited electron-hole complexes in strain-free (111) GaAs/AlGaAs quantum dots grown by droplet epitaxy. We address the complexes with one of the charge carriers residing in the excited state, namely, the "hot" trions X-* and X+*, and the doubly negatively charged exciton X2 -. Our magnetophotoluminescence experiments performed on single quantum dots in the Faraday geometry uncover characteristic emission patterns for each excited electron-hole complex, which are very different from the photoluminescence spectra observed in (001)-grown quantum dots. We present a detailed theory of the fine structure and magnetophotoluminescence spectra of X-*,X+*, and X2 - complexes, governed by the interplay between the electron-hole Coulomb exchange interaction and the heavy-hole mixing, characteristic for these quantum dots with a trigonal symmetry. Comparison between experiment and theory allows for precise charge state identification, as well as extraction of electron-hole exchange interaction constants and g factors for the charge carriers occupying excited states.

  17. Implants as absolute anchorage.

    PubMed

    Rungcharassaeng, Kitichai; Kan, Joseph Y K; Caruso, Joseph M

    2005-11-01

    Anchorage control is essential for successful orthodontic treatment. Each tooth has its own anchorage potential as well as propensity to move when force is applied. When teeth are used as anchorage, the untoward movements of the anchoring units may result in the prolonged treatment time, and unpredictable or less-than-ideal outcome. To maximize tooth-related anchorage, techniques such as differential torque, placing roots into the cortex of the bone, the use of various intraoral devices and/or extraoral appliances have been implemented. Implants, as they are in direct contact with bone, do not possess a periodontal ligament. As a result, they do not move when orthodontic/orthopedic force is applied, and therefore can be used as "absolute anchorage." This article describes different types of implants that have been used as orthodontic anchorage. Their clinical applications and limitations are also discussed. PMID:16463910

  18. Absolute Equilibrium Entropy

    NASA Technical Reports Server (NTRS)

    Shebalin, John V.

    1997-01-01

    The entropy associated with absolute equilibrium ensemble theories of ideal, homogeneous, fluid and magneto-fluid turbulence is discussed and the three-dimensional fluid case is examined in detail. A sigma-function is defined, whose minimum value with respect to global parameters is the entropy. A comparison is made between the use of global functions sigma and phase functions H (associated with the development of various H-theorems of ideal turbulence). It is shown that the two approaches are complimentary though conceptually different: H-theorems show that an isolated system tends to equilibrium while sigma-functions allow the demonstration that entropy never decreases when two previously isolated systems are combined. This provides a more complete picture of entropy in the statistical mechanics of ideal fluids.

  19. The calculation of electron chemical potential and ion charge state and their influence on plasma conductivity in electrical explosion of metal wire

    SciTech Connect

    Shi, Zongqian; Wang, Kun; Li, Yao; Shi, Yuanjie; Wu, Jian; Jia, Shenli

    2014-03-15

    The electron chemical potential and ion charge state (average ion charge and ion distribution) are important parameters in calculating plasma conductivity in electrical explosion of metal wire. In this paper, the calculating method of electron chemical potential and ion charge state is discussed at first. For the calculation of electron chemical potential, the ideal free electron gas model and Thomas-Fermi model are compared and analyzed in terms of the coupling constant of plasma. The Thomas-Fermi ionization model, which is used to calculate ion charge state, is compared with the method based on Saha equation. Furthermore, the influence of electron degenerated energy levels and ion excited states in Saha equation on the ion charge state is also analyzed. Then the influence of different calculating methods of electron chemical potential and ion charge state on plasma conductivity is discussed by applying them in the Lee-More conductivity model.

  20. Materials Characterization at Utah State University: Facilities and Knowledge-base of Electronic Properties of Materials Applicable to Spacecraft Charging

    NASA Technical Reports Server (NTRS)

    Dennison, J. R.; Thomson, C. D.; Kite, J.; Zavyalov, V.; Corbridge, Jodie

    2004-01-01

    In an effort to improve the reliability and versatility of spacecraft charging models designed to assist spacecraft designers in accommodating and mitigating the harmful effects of charging on spacecraft, the NASA Space Environments and Effects (SEE) Program has funded development of facilities at Utah State University for the measurement of the electronic properties of both conducting and insulating spacecraft materials. We present here an overview of our instrumentation and capabilities, which are particularly well suited to study electron emission as related to spacecraft charging. These measurements include electron-induced secondary and backscattered yields, spectra, and angular resolved measurements as a function of incident energy, species and angle, plus investigations of ion-induced electron yields, photoelectron yields, sample charging and dielectric breakdown. Extensive surface science characterization capabilities are also available to fully characterize the samples in situ. Our measurements for a wide array of conducting and insulating spacecraft materials have been incorporated into the SEE Charge Collector Knowledge-base as a Database of Electronic Properties of Materials Applicable to Spacecraft Charging. This Database provides an extensive compilation of electronic properties, together with parameterization of these properties in a format that can be easily used with existing spacecraft charging engineering tools and with next generation plasma, charging, and radiation models. Tabulated properties in the Database include: electron-induced secondary electron yield, backscattered yield and emitted electron spectra; He, Ar and Xe ion-induced electron yields and emitted electron spectra; photoyield and solar emittance spectra; and materials characterization including reflectivity, dielectric constant, resistivity, arcing, optical microscopy images, scanning electron micrographs, scanning tunneling microscopy images, and Auger electron spectra. Further

  1. The reactivity of stoichiometric tungsten oxide clusters towards carbon monoxide: the effects of cluster sizes and charge states.

    PubMed

    Lin, Shu-Juan; Cheng, Jing; Zhang, Chang-Fu; Wang, Bin; Zhang, Yong-Fan; Huang, Xin

    2015-05-01

    Density functional theory (DFT) calculations are employed to investigate the reactivity of tungsten oxide clusters towards carbon monoxide. Extensive structural searches show that all the ground-state structures of (WO3)n(+) (n = 1-4) contain an oxygen radical center with a lengthened W-O bond which is highly active in the oxidation of carbon monoxide. Energy profiles are calculated to determine the reaction mechanisms and evaluate the effect of cluster sizes. The monomer WO3(+) has the highest reactivity among the stoichiometric clusters of different sizes (WO3)n(+) (n = 1-4). The reaction mechanisms for CO with mono-nuclear stoichiometric tungsten oxide clusters with different charges (WO3(-/0/+)) are also studied to clarify the influence of charge states. Our calculated results show that the ability to oxidize CO gets weaker from WO3(+) to WO3(-) as the negative charge accumulates progressively. PMID:25854200

  2. Competition between diagonal and off-diagonal coupling gives rise to charge-transfer states in polymeric solar cells

    PubMed Central

    Yao, Yao; Zhou, Nengji; Prior, Javier; Zhao, Yang

    2015-01-01

    It has long been a puzzle on what drives charge separation in artificial polymeric solar cells as a consensus has yet to emerge among rivaling theories based upon electronic localization and delocalization pictures. Here we propose an alternative using the two-bath spin-boson model with simultaneous diagonal and off-diagonal coupling: the critical phase, which is born out of the competition of the two coupling types, and is neither localized nor delocalized. The decoherence-free feature of the critical phase also helps explain sustained coherence of the charge-transfer state. Exploiting Hamiltonian symmetries in an enhanced algorithm of density-matrix renormalization group, we map out boundaries of the critical phase to a precision previously unattainable, and determine the bath spectral densities inducive to the existence of the charge-transfer state. PMID:26412693

  3. Polydivinylferrocene surface modified electrode for measuring state-of-charge of lead-acid battery

    NASA Astrophysics Data System (ADS)

    Lee, Todd; Singh, Pritam; Baker, Murray V.; Issa, Touma B.

    This paper outlines an investigation of the electrochemical behaviour of polymeric divinylferrocene (PDVF) produced by direct polymerisation of divinylferrocene (DVF) monomer on a glassy carbon substrate. The findings indicate that PDVF undergoes reversible reduction/oxidation in neutral and acidic aqueous media containing perchlorate (ClO 4 -) and sulfhate (SO 4 2-). The anodic peak potential of the PDVF shifts linearly to less positive potentials as the sulfuric acid (H 2SO 4) concentration is increased from 1 to 5 M. The polymer film strongly adheres to the glassy carbon surface and is electrochemically stable when subjected to repeated voltammetric cycling in the potential range of -0.2 to +0.8 V vs. Ag|AgCl. The potential of the partially oxidized film of PVDF on a glassy carbon substrate against a Ag|AgCl/KCl reference electrode in sulfuric acid solution is stable, reproducible and varies linearly with the acid concentration in the range of 1-5 M. This observation may be suitable for potentiometrically measuring the state-of-charge of lead-acid batteries.

  4. State of Charge Dependent Mechanical Integrity Behavior of 18650 Lithium-ion Batteries

    NASA Astrophysics Data System (ADS)

    Xu, Jun; Liu, Binghe; Hu, Dayong

    2016-02-01

    Understanding the mechanism of mechanical deformation/stress-induced electrical failure of lithium-ion batteries (LIBs) is important in crash-safety design of power LIBs. The state of charge (SOC) of LIBs is a critical factor in their electrochemical performance; however, the influence of SOC with mechanical integrity of LIBs remains unclear. This study investigates the electrochemical failure behaviors of LIBs with various SOCs under both compression and bending loadings, underpinned by the short circuit phenomenon. Mechanical behaviors of the whole LIB body, which is regarded as an intact structure, were analyzed in terms of structure stiffness. Results showed that the mechanical behaviors of LIBs depend highly on SOC. Experimental verification on the cathode and anode sheet compression tests show that higher SOC with more lithium inserted in the anode leads to higher structure stiffness. In the bending tests, failure strain upon occurrence of short circuit has an inverse linear relationship with the SOC value. These results may shed light on the fundamental physical mechanism of mechanical integrity LIBs in relation to inherent electrochemical status.

  5. State of Charge Dependent Mechanical Integrity Behavior of 18650 Lithium-ion Batteries

    PubMed Central

    Xu, Jun; Liu, Binghe; Hu, Dayong

    2016-01-01

    Understanding the mechanism of mechanical deformation/stress-induced electrical failure of lithium–ion batteries (LIBs) is important in crash-safety design of power LIBs. The state of charge (SOC) of LIBs is a critical factor in their electrochemical performance; however, the influence of SOC with mechanical integrity of LIBs remains unclear. This study investigates the electrochemical failure behaviors of LIBs with various SOCs under both compression and bending loadings, underpinned by the short circuit phenomenon. Mechanical behaviors of the whole LIB body, which is regarded as an intact structure, were analyzed in terms of structure stiffness. Results showed that the mechanical behaviors of LIBs depend highly on SOC. Experimental verification on the cathode and anode sheet compression tests show that higher SOC with more lithium inserted in the anode leads to higher structure stiffness. In the bending tests, failure strain upon occurrence of short circuit has an inverse linear relationship with the SOC value. These results may shed light on the fundamental physical mechanism of mechanical integrity LIBs in relation to inherent electrochemical status. PMID:26911922

  6. Charge State Coalescence During Electrospray Ionization Improves Peptide Identification by Tandem Mass Spectrometry

    NASA Astrophysics Data System (ADS)

    Meyer, Jesse G.; A. Komives, Elizabeth

    2012-08-01

    We report the effects of supercharging reagents dimethyl sulphoxide (DMSO) and m-nitrobenzyl alcohol ( m-NBA) applied to untargeted peptide identification, with special emphasis on non-tryptic peptides. Peptides generated from a mixture of five standard proteins digested with trypsin, elastase, or pepsin were separated with nanoflow liquid chromatography using mobile phases modified with either 5 % DMSO or 0.1 % m-NBA. Eluting peptides were ionized by online electrospray and sequenced by both CID and ETD using data-dependent MS/MS. Statistically significant improvements in peptide identifications were observed with DMSO co-solvent. In order to understand this observation, we assessed the effects of supercharging reagents on the chromatographic separation and the electrospray quality. The increase in identifications was not due to supercharging, which was greater for the 0.1 % m-NBA co-solvent and not observed for the 5.0 % DMSO co-solvent. The improved MS/MS efficiency using the DMSO modified mobile phase appeared to result from charge state coalescence.

  7. Charge State Coalescence During Electrospray Ionization Improves Peptide Identification by Tandem Mass Spectrometry

    NASA Astrophysics Data System (ADS)

    Meyer, Jesse G.; Komives, Elizabeth A.

    2012-05-01

    We report the effects of supercharging reagents dimethyl sulphoxide (DMSO) and m-nitrobenzyl alcohol (m-NBA) applied to untargeted peptide identification, with special emphasis on non-tryptic peptides. Peptides generated from a mixture of five standard proteins digested with trypsin, elastase, or pepsin were separated with nanoflow liquid chromatography using mobile phases modified with either 5 % DMSO or 0.1 % m-NBA. Eluting peptides were ionized by online electrospray and sequenced by both CID and ETD using data-dependent MS/MS. Statistically significant improvements in peptide identifications were observed with DMSO co-solvent. In order to understand this observation, we assessed the effects of supercharging reagents on the chromatographic separation and the electrospray quality. The increase in identifications was not due to supercharging, which was greater for the 0.1 % m-NBA co-solvent and not observed for the 5.0 % DMSO co-solvent. The improved MS/MS efficiency using the DMSO modified mobile phase appeared to result from charge state coalescence.

  8. Protein diffusion and long-term adsorption states at charged solid surfaces.

    PubMed

    Kubiak-Ossowska, Karina; Mulheran, Paul A

    2012-11-01

    The diffusion pathways of lysozyme adsorbed to a model charged ionic surface are studied using fully atomistic steered molecular dynamics simulation. The simulations start from existing protein adsorption trajectories, where it has been found that one particular residue, Arg128 at the N,C-terminal face, plays a crucial role in anchoring the lysozyme to the surface [Langmuir 2010 , 26 , 15954 - 15965]. We first investigate the desorption pathway for the protein by pulling the Arg128 side chain away from the surface in the normal direction, and its subsequent readsorption, before studying diffusion pathways by pulling the Arg128 side chain parallel to the surface. We find that the orientation of this side chain plays a decisive role in the diffusion process. Initially, it is oriented normal to the surface, aligning in the electrostatic field of the surface during the adsorption process, but after resorption it lies parallel to the surface, being unable to return to its original orientation due to geometric constraints arising from structured water layers at the surface. Diffusion from this alternative adsorption state has a lower energy barrier of ∼0.9 eV, associated with breaking hydrogen bonds along the pathway, in reasonable agreement with the barrier inferred from previous experimental observation of lysozyme surface clustering. These results show the importance of studying protein diffusion alongside adsorption to gain full insight into the formation of protein clusters and films, essential steps in the future development of functionalized surfaces. PMID:23062108

  9. Spatially-Resolved Beam Current and Charge-State Distributions for the NEXT Ion Engine

    NASA Technical Reports Server (NTRS)

    Pollard, James E.; Diamant, Kevin D.; Crofton, Mark W.; Patterson, Michael J.; Soulas, George C.

    2010-01-01

    Plume characterization tests with the 36-cm NEXT ion engine are being performed at The Aerospace Corporation using engineering-model and prototype-model thrusters. We have examined the beam current density and xenon charge-state distribution as functions of position on the accel grid. To measure the current density ratio j++/j+, a collimated Eprobe was rotated through the plume with the probe oriented normal to the accel electrode surface at a distance of 82 cm. The beam current density jb versus radial position was measured with a miniature planar probe at 3 cm from the accel. Combining the j++/j+ and jb data yielded the ratio of total Xe+2 current to total Xe+1 current (J++/J+) at forty operating points in the standard throttle table. The production of Xe+2 and Xe+3 was measured as a function of propellant utilization to support performance and lifetime predictions for an extended throttle table. The angular dependence of jb was measured at intermediate and far-field distances to assist with plume modeling and to evaluate the thrust loss due to beam divergence. Thrust correction factors were derived from the total doubles-to-singles current ratio and from the far-field divergence data

  10. Density functional investigation of the electronic structure and charge transfer excited states of a multichromophoric antenna

    NASA Astrophysics Data System (ADS)

    Basurto, Luis; Zope, Rajendra R.; Baruah, Tunna

    2016-05-01

    We report an electronic structure study of a multichromophoric molecular complex containing two of each borondipyrromethane dye, Zn-tetraphenyl-porphyrin, bisphenyl anthracene and a fullerene. The snowflake shaped molecule behaves like an antenna capturing photon at different frequencies and transferring the photon energy to the porphyrin where electron transfer occurs from the porphyrin to the fullerene. The study is performed within density functional formalism using large polarized Guassian basis sets (12,478 basis functions in total). The energies of the HOMO and LUMO states in the complex, as adjudged by the ionization potential and the electron affinity values, show significant differences with respect to their values in participating subunits in isolation. These differences are also larger than the variations of the ionization potential and electron affinity values observed in non-bonded C60-ZnTPP complexes in co-facial arrangement or end-on orientations. An understanding of the origin of these differences is obtained by a systematic study of the effect of structural strain, the presence of ligands, the effect of orbital delocalization on the ionization energy and the electron affinity. Finally, a few lowest charge transfer energies involving electronic transitions from the porphyrin component to the fullerene subunit of the complex are predicted.

  11. State of Charge Dependent Mechanical Integrity Behavior of 18650 Lithium-ion Batteries.

    PubMed

    Xu, Jun; Liu, Binghe; Hu, Dayong

    2016-01-01

    Understanding the mechanism of mechanical deformation/stress-induced electrical failure of lithium-ion batteries (LIBs) is important in crash-safety design of power LIBs. The state of charge (SOC) of LIBs is a critical factor in their electrochemical performance; however, the influence of SOC with mechanical integrity of LIBs remains unclear. This study investigates the electrochemical failure behaviors of LIBs with various SOCs under both compression and bending loadings, underpinned by the short circuit phenomenon. Mechanical behaviors of the whole LIB body, which is regarded as an intact structure, were analyzed in terms of structure stiffness. Results showed that the mechanical behaviors of LIBs depend highly on SOC. Experimental verification on the cathode and anode sheet compression tests show that higher SOC with more lithium inserted in the anode leads to higher structure stiffness. In the bending tests, failure strain upon occurrence of short circuit has an inverse linear relationship with the SOC value. These results may shed light on the fundamental physical mechanism of mechanical integrity LIBs in relation to inherent electrochemical status. PMID:26911922

  12. Energy awareness for supercapacitors using Kalman filter state-of-charge tracking

    NASA Astrophysics Data System (ADS)

    Nadeau, Andrew; Hassanalieragh, Moeen; Sharma, Gaurav; Soyata, Tolga

    2015-11-01

    Among energy buffering alternatives, supercapacitors can provide unmatched efficiency and durability. Additionally, the direct relation between a supercapacitor's terminal voltage and stored energy can improve energy awareness. However, a simple capacitive approximation cannot adequately represent the stored energy in a supercapacitor. It is shown that the three branch equivalent circuit model provides more accurate energy awareness. This equivalent circuit uses three capacitances and associated resistances to represent the supercapacitor's internal SOC (state-of-charge). However, the SOC cannot be determined from one observation of the terminal voltage, and must be tracked over time using inexact measurements. We present: 1) a Kalman filtering solution for tracking the SOC; 2) an on-line system identification procedure to efficiently estimate the equivalent circuit's parameters; and 3) experimental validation of both parameter estimation and SOC tracking for 5 F, 10 F, 50 F, and 350 F supercapacitors. Validation is done within the operating range of a solar powered application and the associated power variability due to energy harvesting. The proposed techniques are benchmarked against the simple capacitive model and prior parameter estimation techniques, and provide a 67% reduction in root-mean-square error for predicting usable buffered energy.

  13. Steady-state electrodiffusion. Scaling, exact solution for ions of one charge, and the phase plane.

    PubMed Central

    Leuchtag, H R; Swihart, J C

    1977-01-01

    This is the first of two papers dealing with electrodiffusion theory (the Nernst-Planck equation coupled with Gauss's law) and its application to the current-voltage behavior of squid axon. New developments in the exact analysis of the steady-state electrodiffusion problem presented here include (a) a scale transformation that connects a given solution to an infinity of other solutions, suggesting the po-sibility of direct comparison of electrical data for membranes with different thicknesses and other properties; (b) a first-integral relation between the electric field and ion densities more general than analogous relations previously reported, and (c) an exact solution for the homovalent system, i.e., a membrane system permeated by various ion species of the same charge. The latter is a generalization of the known one-ion solution. The properties of the homovalent solution are investigated analytically and graphically. In particular we study the phase-plane curves, which reduce to the parabolas discussed by K. S. Cole in the special case in which the current-density parameter (a linear combination of the ionic current densities) is zero. PMID:831855

  14. The beam commissioning of a CW high charge state heavy ion RFQ

    NASA Astrophysics Data System (ADS)

    Zhu, K.; Lu, Y. R.; Yin, X. J.; Yang, Y. Q.; Gao, S. L.; Wang, Z.; He, Y.; Liu, G.; Zhang, X. H.; Yuan, Y. J.; Zhao, H. W.; Xia, J. W.; Chen, C. E.

    2015-09-01

    The SSC-LINAC project is launched at Institute of Modern Physics in China to develop one new linear accelerator (LINAC) injector for separated sector cyclotron (SSC). It includes a high charge state ion source, a CW RFQ and a DTL section, and is designed to accelerate ions up to 580 keV/u. Now the ion source and the RFQ cavity have been installed in the main hall and the beam commissioning has been carried out. Two kinds of ions have been tested, 16O5+ and 40Ar8+. The experiment result of 16O5+ is: the measured beam current is 180 μA at entrance of RFQ and 150 μA at exit of RFQ. The output energy of 16O5+ is 141.89 keV/u. The measured beam current is 210 μA at entrance of RFQ and 198 μA at exit of RFQ for 40Ar8+. The output energy of 40Ar8+ is 142.78 keV/u. The experiment results agree with the design parameters of RFQ very well. This paper presents: the design consideration of beam dynamics, RF and cooling structure design; measurement of the cold model; high power test of RFQ and beam commissioning result.

  15. CHARGE STATE EVOLUTION IN THE SOLAR WIND. RADIATIVE LOSSES IN FAST SOLAR WIND PLASMAS

    SciTech Connect

    Landi, E.; Gruesbeck, J. R.; Lepri, S. T.; Zurbuchen, T. H.; Fisk, L. A.

    2012-10-10

    We study the effects of departures from equilibrium on the radiative losses of the accelerating fast, coronal hole-associated solar wind plasma. We calculate the evolution of the ionic charge states in the solar wind with the Michigan Ionization Code and use them to determine the radiative losses along the wind trajectory. We use the velocity, electron temperature, and electron density predicted by Cranmer et al. as a benchmark case even though our approach and conclusions are more broadly valid. We compare non-equilibrium radiative losses to values calculated assuming ionization equilibrium at the local temperature, and we find that differences are smaller than 20% in the corona but reach a factor of three in the upper chromosphere and transition region. Non-equilibrium radiative losses are systematically larger than the equilibrium values, so that non-equilibrium wind plasma radiates more efficiently in the transition region. Comparing the magnitude of the dominant energy terms in the Cranmer et al. model, we find that wind-induced departures from equilibrium are of the same magnitude as the differences between radiative losses and conduction in the energy equation. We investigate which ions are most responsible for such effects, finding that carbon and oxygen are the main source of departures from equilibrium. We conclude that non-equilibrium effects on the wind energy equation are significant and recommend that they are included in theoretical models of the solar wind, at least for carbon and oxygen.

  16. Charge-state dependence of fast heavy-ion-induced desorption yields described in a thermal model

    SciTech Connect

    Nieschler, E.; Nees, B.; Voit, H.

    1988-11-01

    Yields for secondary ions desorbed from valine, tetrabutylammonium tetraphenylborate, and CsI samples by 13- and 30-MeV /sup 16/O ions have been measured as a function of the primary-ion charge state. The experimental data can be reproduced in terms of a simple thermal model.

  17. Improved Cell Typing by Charge-State Deconvolution of matrix-assisted laser desorption/ionization Mass Spectra

    SciTech Connect

    Wilkes, Jon G.; Buzantu, Dan A.; Dare, Diane J.; Dragan, Yvonne P.; Chiarelli, M. Paul; Holland, Ricky D.; Beaudoin, Michael; Heinze, Thomas M.; Nayak, Rajesh; Shvartsburg, Alexandre A.

    2006-05-30

    Robust, specific, and rapid identification of toxic strains of bacteria and viruses, to guide the mitigation of their adverse health effects and optimum implementation of other response actions, remains a major analytical challenge. This need has driven the development of methods for classification of microorganisms using mass spectrometry, particularly matrix-assisted laser desorption ionization MS (MALDI) that allows high throughput analyses with minimum sample preparation. We describe a novel approach to cell typing based on pattern recognition of MALDI spectra, which involves charge-state deconvolution in conjunction with a new correlation analysis procedure. The method is applicable to both prokaryotic and eukaryotic cells. Charge-state deconvolution improves the quantitative reproducibility of spectra because multiply-charged ions resulting from the same biomarker attaching a different number of protons are recognized and their abundances are combined. This allows a clearer distinction of bacterial strains or of cancerous and normal liver cells. Improved class distinction provided by charge-state deconvolution was demonstrated by cluster spacing on canonical variate score charts and by correlation analyses. Deconvolution may enhance detection of early disease state or therapy progress markers in various tissues analyzed by MALDI.

  18. Evolution of the Relationships between Helium Abundance, Minor Ion Charge State, and Solar Wind Speed over the Solar Cycle

    NASA Astrophysics Data System (ADS)

    Kasper, J. C.; Stevens, M. L.; Korreck, K. E.; Maruca, B. A.; Kiefer, K. K.; Schwadron, N. A.; Lepri, S. T.

    2012-02-01

    The changing relationships between solar wind speed, helium abundance, and minor ion charge state are examined over solar cycle 23. Observations of the abundance of helium relative to hydrogen (A He ≡ 100 × n He/n H) by the Wind spacecraft are used to examine the dependence of A He on solar wind speed and solar activity between 1994 and 2010. This work updates an earlier study of A He from 1994 to 2004 to include the recent extreme solar minimum and broadly confirms our previous result that A He in slow wind is strongly correlated with sunspot number, reaching its lowest values in each solar minima. During the last minimum, as sunspot numbers reached their lowest levels in recent history, A He continued to decrease, falling to half the levels observed in slow wind during the previous minimum and, for the first time observed, decreasing even in the fastest solar wind. We have also extended our previous analysis by adding measurements of the mean carbon and oxygen charge states observed with the Advanced Composition Explorer spacecraft since 1998. We find that as solar activity decreased, the mean charge states of oxygen and carbon for solar wind of a given speed also fell, implying that the wind was formed in cooler regions in the corona during the recent solar minimum. The physical processes in the coronal responsible for establishing the mean charge state and speed of the solar wind have evolved with solar activity and time.

  19. 1972-73 Student Charges at State and Land Grant Universities (Tuition, Required Fees, Room and Board).

    ERIC Educational Resources Information Center

    National Association of State Universities and Land-Grant Colleges, Washington, DC. Office of Research and Information.

    Tuition for resident students at state and land-grant universities increased less in fall 1972 than it has for any fall since 1968. Two universities even put tuition decreases into effect. The slowdown in the amount of increase in student charges is based on responses to a survey from 98 of the 101 multi-campus institutions holding membership in…

  20. Excited state intramolecular charge transfer reaction in nonaqueous electrolyte solutions: Temperature dependence

    SciTech Connect

    Pradhan, Tuhin; Gazi, Harun Al Rasid; Biswas, Ranjit

    2009-08-07

    Temperature dependence of the excited state intramolecular charge transfer reaction of 4-(1-azetidinyl)benzonitrile (P4C) in ethyl acetate (EA), acetonitrile (ACN), and ethanol at several concentrations of lithium perchlorate (LiClO{sub 4}) has been investigated by using the steady state and time resolved fluorescence spectroscopic techniques. The temperature range considered is 267-343 K. The temperature dependent spectral peak shifts and reaction driving force (-{Delta}G{sub r}) in electrolyte solutions of these solvents can be explained qualitatively in terms of interaction between the reactant molecule and ion-atmosphere. Time resolved studies indicate that the decay kinetics of P4C is biexponential, regardless of solvents, LiClO{sub 4} concentrations, and temperatures considered. Except at higher electrolyte concentrations in EA, reaction rates in solutions follow the Arrhenius-type temperature dependence where the estimated activation energy exhibits substantial electrolyte concentration dependence. The average of the experimentally measured activation energies in these three neat solvents is found to be in very good agreement with the predicted value based on data in room temperature solvents. While the rate constant in EA shows a electrolyte concentration induced parabolic dependence on reaction driving force (-{Delta}G{sub r}), the former in ethanol and ACN increases only linearly with the increase in driving force (-{Delta}G{sub r}). The data presented here also indicate that the step-wise increase in solvent reorganization energy via sequential addition of electrolyte induces the ICT reaction in weakly polar solvents to crossover from the Marcus inverted region to the normal region.

  1. Merit of ground-state electronegativities; a reply to ``Comments on `Introduction to the chemistry of fractionally charged atoms: Electronegativity' ''

    NASA Astrophysics Data System (ADS)

    Lackner, Klaus S.; Zweig, George

    1987-09-01

    The arguments presented in the Comment by Liebman and Huheey are shown to be incorrect. The operational equivalence of Mulliken ground-state electronegativities and Pauling electronegativities is demonstrated for neutral atoms. It is shown that ground-state electronegativities and valence-state electronegativities for both neutral atoms and ions are also operationally equivalent. A single electronegativity scale based on Mulliken ground-state electronegativities may therefore be used for neutral atoms, ions, and fractionally charged atoms, as originally implied in the paper by Lackner and Zweig.

  2. Merit of ground-state electronegativities; a reply to ''Comments on 'Introduction to the chemistry of fractionally charged atoms: Electronegativity' ''

    SciTech Connect

    Lackner, K.S.; Zweig, G.

    1987-09-01

    The arguments presented in the Comment by Liebman and Huheey are shown to be incorrect. The operational equivalence of Mulliken ground-state electronegativities and Pauling electronegativities is demonstrated for neutral atoms. It is shown that ground-state electronegativities and valence-state electronegativities for both neutral atoms and ions are also operationally equivalent. A single electronegativity scale based on Mulliken ground-state electronegativities may therefore be used for neutral atoms, ions, and fractionally charged atoms, as originally implied in the paper by Lackner and Zweig.

  3. Quantitative charge state analysis of manganese biominerals in aqueous suspension using scanning transmission X-ray microscopy (STXM)

    NASA Astrophysics Data System (ADS)

    Pecher, K.; McCubbery, D.; Kneedler, E.; Rothe, J.; Bargar, J.; Meigs, G.; Cox, L.; Nealson, K.; Tonner, B.

    2003-03-01

    We have applied Scanning Transmission Soft X-ray Microscopy (STXM) to investigate the charge state distribution of Mn in two kinds of Mn-biominerals, Mn nodules collected from Lake Michigan sediments and Mn precipitates formed by spores of a marine bacillus SG-1 under transport limited reaction conditions. A data analysis technique was developed, which allows for extraction of spatially resolved 2-d charge state maps of manganese on a submicron level. We find that the charge state of Mn dominates the spectral shape of L-edge spectra of environmentally important single oxidation state Mn minerals and that spectra of mixed oxidation state oxides can be modelled by a combination of appropriate single oxidation state reference spectra. Two-dimensional maps of charge state distributions clearly reveal domains of different oxidation states within single particles of Mn-micronodules. Spots of preferred accumulation of Mn(II) were found, which indicates biogenic precipitation of Mn(II)-species as a first step of nodule formation. The presence of Mn(III) in the studied sediment samples suggests the involvement of one-electron oxidation processes and reaction conditions which inhibit or slow down the disproportionation of Mn(III)-products. Under transport limited conditions, Mn oxidation products formed by spores of the marine bacillus SG-1 can vary from cell to cell. The presence of significant amounts of Mn(III) containing species points to the involvement of one-electron oxidation reactions as in the case of the micro-nodules. Our technique and the results obtained form a new basis for the mechanistic understanding of the formation of Mn biominerals in the environment.

  4. Quantum states of charge carriers and longitudinal conductivity in double periodic n-type semiconductor lattice structures in electric field

    SciTech Connect

    Perov, A. A. Penyagin, I. V.

    2015-07-15

    Quantum states of charge carriers in double periodic semiconductor superlattices of n-type quantum dots with Rashba spin–orbit coupling in an electron gas have been calculated in the one-electron approximation in the presence of mutually perpendicular electric and magnetic fields. For these structures in weak constant electric field, the solution to the quasi-classical kinetic Boltzmann equation shows that the states of carriers in magnetic Landau minibands with negative differential conductivity are possible.

  5. The low-lying {pi}{sigma}* state and its role in the intramolecular charge transfer of aminobenzonitriles and aminobenzethyne

    SciTech Connect

    Lee, Jae-Kwang; Fujiwara, Takashige; Kofron, William G.; Zgierski, Marek Z.; Lim, Edward C.

    2008-04-28

    Electronic absorption spectra of the low-lying {pi}{pi}* and {pi}{sigma}* states of several aminobenzonitriles and 4-dimethylaminobenzethyne have been studied by time-resolved transient absorption and time-dependent density functional theory calculation. In acetonitrile, the lifetime of the {pi}{sigma}*-state absorption is very short (picoseconds or subpicosecond) for molecules that exhibit intramolecular charge transfer (ICT), and very long (nanoseconds) for those that do not. Where direct comparison of the temporal characteristics of the {pi}{sigma}*-state and the ICT-state transients could be made, the formation rate of the ICT state is identical to the decay rate of the {pi}{sigma}* state within the experimental uncertainty. These results are consistent with the {pi}{sigma}*-mediated ICT mechanism, L{sub a} ({pi}{pi}*){yields}{pi}{sigma}*{yields}ICT, in which the decay rate of the {pi}{sigma}* state is determined by the rate of the solvent-controlled {pi}{sigma}*{yields}ICT charge-shift reaction. The {pi}{pi}*{yields}{pi}{sigma}* state crossing does not occur in 3-dimethylaminobenzonitrile or 2-dimethylaminobenzonitrile, as predicted by the calculation, and 4-aminobenzonitrile and 4-dimethylaminobenzethyne does not exhibit the ICT reaction, consistent with the higher energy of the ICT state relative to the {pi}{sigma}* state.

  6. Active charge state control of single NV centres in diamond by in-plane Al-Schottky junctions

    PubMed Central

    Schreyvogel, C.; Polyakov, V.; Wunderlich, R.; Meijer, J.; Nebel, C. E.

    2015-01-01

    In this paper, we demonstrate an active control of the charge state of a single nitrogen-vacancy (NV) centre by using in-plane Schottky-diode geometries with aluminium on hydrogen-terminated diamond surface. A switching between NV+, NV0 and NV− can be performed with the Al-gates which apply electric fields in the hole depletion region of the Schottky junction that induces a band bending modulation, thereby shifting the Fermi-level over NV charge transition levels. We simulated the in-plane band structure of the Schottky junction with the Software ATLAS by solving the drift-diffusion model and the Poisson-equation self-consistently. We simulated the IV-characteristics, calculated the width of the hole depletion region, the position of the Fermi-level intersection with the NV charge transition levels for different reverse bias voltages applied on the Al-gate. We can show that the field-induced band bending modulation in the depletion region causes a shifting of the Fermi-level over NV charge transition levels in such a way that the charge state of a single NV centre and thus its electrical and optical properties is tuned. In addition, the NV centre should be approx. 1–2 μm away from the Al-edge in order to be switched with moderate bias voltages. PMID:26177799

  7. High rate partial-state-of-charge operation of VRLA batteries

    NASA Astrophysics Data System (ADS)

    Moseley, Patrick T.

    The world market for 12 V SLI batteries currently stands at around US$ 12 billion. The lack of a serious challenge from other battery types has allowed lead-acid products to serve this market exclusively, with minimal demand for product improvement through research and development, and a sharp competition has, over time, cut sales prices to commodity levels. The electrochemical storage of energy in automobiles now faces the possibility of a major change, in the form of the proposed 36/42 V electrical systems for vehicles that remain primarily powered by internal combustion engines, and of the hybrid electric vehicle. The duty cycle for these two applications sees the battery held at a partial-state-of-charge (PSoC) for most of its life and required to supply, and to accept, charge at unprecedented rates. The remarkable advances achieved with VRLA battery technology for electric vehicles during the past 8-10 years will be of only passing value in overcoming the challenges posed by high rate PSoC service in 36/42 V and HEV duty. This is because the failure modes seen in PSoC are quite different from those faced in EV (deep cycle) use. The replacement of the 12 V SLI will not take place rapidly. However, if the applications which take its place are to be satisfied by a lead-acid product (probably VRLA), rather than by a battery of a different chemistry, a program of development as successful as that mounted for deep cycle duty will be required. The present phase of the Advanced Lead-Acid Battery Consortium (ALABC) R&D program has begun to shed light on those aspects of the function of a VRLA battery which currently limit its life in high rate PSoC duty. The program is also pursuing the several technologies which show promise of overcoming those limits, including multiple tab plate design, mass transport facilitation and minor component (both beneficial and detrimental impurity) management. This paper presents a brief review of the changes which are taking place in

  8. Charge states of the reactants in the hydrogen passivation of interstitial iron in P-type crystalline silicon

    NASA Astrophysics Data System (ADS)

    Sun, Chang; Liu, AnYao; Phang, Sieu Pheng; Rougieux, Fiacre E.; Macdonald, Daniel

    2015-08-01

    Significant reductions in interstitial iron (Fei) concentrations occur during annealing Fe-containing silicon wafers with silicon nitride films in the temperature range of 250 °C-700 °C. The silicon nitride films are known to release hydrogen during the annealing step. However, in co-annealed samples with silicon oxide films, which are hydrogen-lean, changes in the Fei concentrations were much less significant. The precipitation of Fei is ruled out as a possible explanation for the significant reductions. The hydrogen passivation of Fei, which is the complexing of monatomic H and isolated Fei forming a recombination-inactive hydride, is proposed as the most probable model to explain the reductions. Under the assumption that the reduction is caused by the hydrogenation of Fei, the reactants' charge states in the hydrogenation reaction are determined by two independent approaches. In the first approach, illumination is found to have a small but detectible impact on the reaction kinetics in the lower temperature range. The dominating reactants' charge states are concluded to be Fe0 + H+ as revealed by modelling the injection-dependent charge states of isolated Fei and monatomic H. In the second approach, the reaction kinetics are fitted with the Arrhenius equation over a large temperature range of 250 °C-700 °C. A reasonable fit is only obtained when assuming the reacting charge states are Fe0 + H+. This supports the conclusion on the reacting charge states and also gives a value of the activation energy of hydrogenation in the 0.7-0.8 eV range.

  9. Controlling the Charge State and Redox Properties of Supported Polyoxometalates via Soft Landing of Mass Selected Ions

    SciTech Connect

    Gunaratne, Kalupathirannehelage Don D.; Johnson, Grant E.; Andersen, Amity; Du, Dan; Zhang, Weiying; Prabhakaran, Venkateshkumar; Lin, Yuehe; Laskin, Julia

    2014-12-04

    We investigate the controlled deposition of Keggin polyoxometalate (POM) anions, PMo12O403- and PMo12O402-, onto different self-assembled monolayer (SAM) surfaces via soft landing of mass-selected ions. Utilizing in situ infrared reflection absorption spectroscopy (IRRAS), ex situ cyclic voltammetry (CV) and electronic structure calculations, we examine the structure and charge retention of supported multiply-charged POM anions and characterize the redox properties of the modified surfaces. SAMs of alkylthiol (HSAM), perfluorinated alkylthiol (FSAM), and alkylthiol terminated with NH3+ functional groups (NH3+SAM) are chosen as model substrates for soft landing to examine the factors which influence the immobilization and charge retention of multiply charged anionic molecules. The distribution of charge states of POMs on different SAM surfaces are determined by comparing the IRRAS spectra with vibrational spectra calculated using density functional theory (DFT). In contrast to the results obtained previously for multiply charged cations, soft landed anions are found to retain charge on all three SAM surfaces. This charge retention is attributed to the substantial electron binding energy of the POM anions. Investigation of redox properties by CV reveals that, while surfaces prepared by soft landing exhibit similar features to those prepared by adsorption of POM from solution, the soft landed POM2- has a pronounced shift in oxidation potential compared to POM3- for one of the redox couples. These results demonstrate that ion soft landing is uniquely suited for precisely controlled preparation of substrates with specific electronic and chemical properties that cannot be achieved using conventional deposition techniques.

  10. Absolute neutrino mass measurements

    NASA Astrophysics Data System (ADS)

    Wolf, Joachim

    2011-10-01

    The neutrino mass plays an important role in particle physics, astrophysics and cosmology. In recent years the detection of neutrino flavour oscillations proved that neutrinos carry mass. However, oscillation experiments are only sensitive to the mass-squared difference of the mass eigenvalues. In contrast to cosmological observations and neutrino-less double beta decay (0v2β) searches, single β-decay experiments provide a direct, model-independent way to determine the absolute neutrino mass by measuring the energy spectrum of decay electrons at the endpoint region with high accuracy. Currently the best kinematic upper limits on the neutrino mass of 2.2eV have been set by two experiments in Mainz and Troitsk, using tritium as beta emitter. The next generation tritium β-experiment KATRIN is currently under construction in Karlsruhe/Germany by an international collaboration. KATRIN intends to improve the sensitivity by one order of magnitude to 0.2eV. The investigation of a second isotope (137Rh) is being pursued by the international MARE collaboration using micro-calorimeters to measure the beta spectrum. The technology needed to reach 0.2eV sensitivity is still in the R&D phase. This paper reviews the present status of neutrino-mass measurements with cosmological data, 0v2β decay and single β-decay.

  11. Absolute neutrino mass measurements

    SciTech Connect

    Wolf, Joachim

    2011-10-06

    The neutrino mass plays an important role in particle physics, astrophysics and cosmology. In recent years the detection of neutrino flavour oscillations proved that neutrinos carry mass. However, oscillation experiments are only sensitive to the mass-squared difference of the mass eigenvalues. In contrast to cosmological observations and neutrino-less double beta decay (0v2{beta}) searches, single {beta}-decay experiments provide a direct, model-independent way to determine the absolute neutrino mass by measuring the energy spectrum of decay electrons at the endpoint region with high accuracy.Currently the best kinematic upper limits on the neutrino mass of 2.2eV have been set by two experiments in Mainz and Troitsk, using tritium as beta emitter. The next generation tritium {beta}-experiment KATRIN is currently under construction in Karlsruhe/Germany by an international collaboration. KATRIN intends to improve the sensitivity by one order of magnitude to 0.2eV. The investigation of a second isotope ({sup 137}Rh) is being pursued by the international MARE collaboration using micro-calorimeters to measure the beta spectrum. The technology needed to reach 0.2eV sensitivity is still in the R and D phase. This paper reviews the present status of neutrino-mass measurements with cosmological data, 0v2{beta} decay and single {beta}-decay.

  12. Hospital charges for people with AIDS in Washington State: utilization of a statewide hospital discharge data base.

    PubMed Central

    Lafferty, W E; Hopkins, S G; Honey, J; Harwell, J D; Shoemaker, P C; Kobayashi, J M

    1988-01-01

    We analyzed Washington State inpatient hospital utilization for 165 AIDS (acquired immunodeficiency syndrome) cases with 344 hospitalizations from July 1984 through December 1985. We found that mean charges per hospitalization were $9,166 and mean length of stay was 13.3 days. In addition, evaluation of two diagnosis-related groups (DRGs 079 and 398) commonly used for AIDS hospitalizations showed that AIDS hospitalizations were substantially more expensive than non-AIDS hospitalizations within the same diagnosis-related group. AIDS-specific diagnosis-related groups may be necessary to achieve a balance between inpatient charges and reimbursements. PMID:3133953

  13. A status report on the design and implementation of state renewable portfolio standards and system benefits charge policies

    SciTech Connect

    Porter, K.; Wiser, R.

    2000-05-01

    At last year's Windpower conference, we reported on state policies to foster renewable energy as part of efforts to restructure state electric power markets. The primary policies states are pursuing for renewables are system benefits charges (SBC) and renewable portfolio standards (RPS). Renewable portfolio standard policies began taking effect this year, while other states are continuing to work on the design of their RPS implementation strategies. In addition, states have begun distributing proceeds from their SBC funds. As a result, some renewable energy projects are beginning to materialize. This paper provides an update on state efforts with these two policies and examines some of the implementation issues and difficulties that states have faced thus far.

  14. Dynamics of the Rydberg state population of slow highly charged ions impinging a solid surface at arbitrary collision geometry

    NASA Astrophysics Data System (ADS)

    Nedeljković, N. N.; Majkić, M. D.; Božanić, D. K.; Dojčilović, R. J.

    2016-06-01

    We consider the population dynamics of the intermediate Rydberg states of highly charged ions (core charge Z\\gg 1, principal quantum number {n}{{A}}\\gg 1) interacting with solid surfaces at arbitrary collision geometry. The recently developed resonant two-state vector model for the grazing incidence (2012 J. Phys. B: At. Mol. Opt. Phys. 45 215202) is extended to the quasi-resonant case and arbitrary angle of incidence. According to the model, the population probabilities depend both on the projectile parallel and perpendicular velocity components, in a complementary way. A cascade neutralization process for {{{Xe}}}Z+ ions, for Z=15{--}45, interacting with a conductive-surface is considered by taking into account the population dynamics. For an arbitrary collision geometry and given range of ionic velocities, a micro-staircase model for the simultaneous calculation of the kinetic energy gain and the charge state of the ion in front of the surface is proposed. The relevance of the obtained results for the explanation of the formation of nanostructures on solid surfaces by slow highly charged ions for normal incidence geometry is briefly discussed.

  15. Defect states and charge trapping characteristics of HfO{sub 2} films for high performance nonvolatile memory applications

    SciTech Connect

    Zhang, Y.; Shao, Y. Y.; Lu, X. B. Zeng, M.; Zhang, Z.; Gao, X. S.; Zhang, X. J.; Liu, J.-M.; Dai, J. Y.

    2014-10-27

    In this work, we present significant charge trapping memory effects of the metal-hafnium oxide-SiO{sub 2}-Si (MHOS) structure. The devices based on 800 °C annealed HfO{sub 2} film exhibit a large memory window of ∼5.1 V under ±10 V sweeping voltages and excellent charge retention properties with only small charge loss of ∼2.6% after more than 10{sup 4 }s retention. The outstanding memory characteristics are attributed to the high density of deep defect states in HfO{sub 2} films. We investigated the defect states in the HfO{sub 2} films by photoluminescence and photoluminescence excitation measurements and found that the defect states distributed in deep energy levels ranging from 1.1 eV to 2.9 eV below the conduction band. Our work provides further insights for the charge trapping mechanisms of the HfO{sub 2} based MHOS devices.

  16. Impedance spectra classification for determining the state of charge on a lithium iron phosphate cell using a support vector machine

    NASA Astrophysics Data System (ADS)

    Jansen, P.; Vergossen, D.; Renner, D.; John, W.; Götze, J.

    2015-11-01

    An alternative method for determining the state of charge (SOC) on lithium iron phosphate cells by impedance spectra classification is given. Methods based on the electric equivalent circuit diagram (ECD), such as the Kalman Filter, the extended Kalman Filter and the state space observer, for instance, have reached their limits for this cell chemistry. The new method resigns on the open circuit voltage curve and the parameters for the electric ECD. Impedance spectra classification is implemented by a Support Vector Machine (SVM). The classes for the SVM-algorithm are represented by all the impedance spectra that correspond to the SOC (the SOC classes) for defined temperature and aging states. A divide and conquer based search algorithm on a binary search tree makes it possible to grade measured impedances using the SVM method. Statistical analysis is used to verify the concept by grading every single impedance from each impedance spectrum corresponding to the SOC by class with different magnitudes of charged error.

  17. [Photoinduced charge separation in solid state and molecular systems]. Final report

    SciTech Connect

    Not Available

    1993-10-01

    A critical theme has been to understand the role of intrinsic cyanometalate overlayers in modulating interfacial photoinduced charge transfer processes occurring at the Cd chalconide/aqueous ferri-ferrocyanide interface. Structural and charge transfer studies of [CdFe(CN){sub 6}]{sup 2-/1-} overlayers have been undertaken. It is reiterated that the focus of attention on the Cd ferrocyanide overlayer as a critical element in II-VI semiconductor based photoelectrochemical cells, is correct. A new project on metallization of solid supports, using photodeposition of Pt, has been initiated. A project has also been started in the area of visible light, molecular, charge transfer photochemistry.

  18. Charge Order in LuFe2O4: Antiferroelectric Ground State and Coupling to Magnetism

    SciTech Connect

    Angst, Manuel; Hermann, Raphael P.; Christianson, Andrew D; Lumsden, Mark D; Lee, C; Whangbo, M.-H.; Kim, J.-W.; Ryan, P J; Nagler, Stephen E; Tian, Wei; Jin, Rongying; Sales, Brian C; Mandrus, David

    2008-11-01

    X-ray scattering by multiferroic LuFe2O4 is reported. Below 320 K, superstructure reflections indicate an incommensurate charge order with propagation close to 1 3 1 3 3 2 . The corresponding charge configuration, also found by electronic structure calculations as most stable, contains polar Fe=O double layers with antiferroelectric stacking. Diffuse scattering at 360 K, with 1 3 1 3 0 propagation, indicates ferroelectric short-range correlations between neighboring double layers. The temperature dependence of the incommensuration indicates that charge order and magnetism are coupled.

  19. Minimum uncertainty states in angular momentum and angle variables for charged particles in structured electromagnetic fields

    NASA Astrophysics Data System (ADS)

    Rodríguez-Méndez, D.; Hacyan, S.; Jáuregui, R.

    2013-10-01

    We study the phase-space properties of a charged particle in a static electromagnetic field exhibiting vortex pairs with complementary topological charges and in a pure gauge field. A stationary solution of the Schrödinger equation that minimizes the uncertainty relations for angular momentum and trigonometric functions of the phase is obtained. It does not exhibit vortices and the angular momentum is due to the gauge field only. Increasing the topological charge of the vortices increases the regions where the Wigner function in the angle-angular momentum plane takes negative values, and thus enhances the quantum character of the dynamics.

  20. Topics in quantum transport of charge and heat in solid state systems

    NASA Astrophysics Data System (ADS)

    Choi, Yunjin

    In the thesis, we present a series of investigations for quantum transport of charge and heat in solid state systems. The first topic of the thesis focuses on the fundamental quantum problems which can be studied with electron transport along with the correlations of detectors to measure physical properties. We theoretically describe a generalized ``which-path'' measurement using a pair of coupled electronic Mach-Zehnder Interferometers. In the second topic of thesis, we investigate an operational approach to measure the tunneling time based on the Larmor clock. To handle the cases of indirect measurement from the first and second topics, we introduce the contextual values formalism. The form of the contextual values provides direct physical insight into the measurement being performed, providing information about the correlation strength between system and detector, the measurement inefficiency, the proper background removal, and the conditioned average value of the system operator. Additionally, the weak interaction limit of these conditioned averages produces weak values of the system operator and an additional detector dependent disturbance term for both cases. In our treatment of the third topic of the thesis, we propose a three terminal heat engine based on semiconductor superlattices for energy harvesting. The periodicity of the superlattice structure creates an energy miniband, giving an energy window to allow electron transport. We find that this device delivers a large amount of power, nearly twice that produced by the heat engine based on quantum wells, with a small reduction of efficiency. This engine also works as a refrigerator in a different regime of the system's parameters. The thermoelectric performance of the refrigerator is analyzed, including the cooling power and coefficient of performance in the optimized condition. We also calculate phonon heat current through the system and explore the reduction of phonon heat current compared to the bulk

  1. Ground state configurations of charged particles in a disk at zero temperature

    NASA Astrophysics Data System (ADS)

    Cerkaski, M.; Nazmitdinov, R. G.

    2014-11-01

    We discuss a novel theoretical approach which explains the self-organization of charged particles in a disk geometry. It allows to calculate readily equilibrium configurations for n <= 400 with a remarkable accuracy, when compared with the molecular dynamics calculations.

  2. Doping dependence of self-diffusion in germanium and the charge states of vacancies

    SciTech Connect

    Suedkamp, T.; Bracht, H.; Impellizzeri, G.; Lundsgaard Hansen, J.; Nylandsted Larsen, A.; Haller, E. E.

    2013-06-17

    Self-diffusion in boron-doped germanium has been studied at temperatures between 526 and 749 Degree-Sign C with secondary ion mass spectrometry. Self-diffusion under acceptor doping is retarded compared to intrinsic conditions. This demonstrates the contribution of charged vacancies in self-diffusion. Taking into account the dominance of doubly negatively charged vacancies under donor doping, the doping dependence of self-diffusion is best described with an inverse level ordering for singly and doubly negatively charged vacancies for all doping conditions. The level ordering explains the dominance of doubly charged vacancies under donor doping and their decreasing contribution with increasing acceptor doping until neutral vacancies mediate self-diffusion.

  3. Fluctuations in Electronic Energy Affecting Singlet Fission Dynamics and Mixing with Charge-Transfer State: Quantum Dynamics Study.

    PubMed

    Fujihashi, Yuta; Ishizaki, Akihito

    2016-02-01

    Singlet fission is a spin-allowed process by which a singlet excited state is converted to two triplet states. To understand mechanisms of the ultrafast fission via a charge transfer (CT) state, one has investigated the dynamics through quantum-dynamical calculations with the uncorrelated fluctuation model; however, the electronic states are expected to experience the same fluctuations induced by the surrounding molecules because the electronic structure of the triplet pair state is similar to that of the singlet state except for the spin configuration. Therefore, the fluctuations in the electronic energies could be correlated, and the 1D reaction coordinate model may adequately describe the fission dynamics. In this work we develop a model for describing the fission dynamics to explain the experimentally observed behaviors. We also explore impacts of fluctuations in the energy of the CT state on the fission dynamics and the mixing with the CT state. The overall behavior of the dynamics is insensitive to values of the reorganization energy associated with the transition from the singlet state to the CT state, although the coherent oscillation is affected by the fluctuations. This result indicates that the mixing with the CT state is rather robust under the fluctuations in the energy of the CT state as well as the high-lying CT state. PMID:26732701

  4. Sun-to-Earth Analysis of Heavy Ion Charge States and Solar Wind Properties in Pseudo Streamers

    NASA Astrophysics Data System (ADS)

    Oran, R.; van der Holst, B.; Landi, E.; Gombosi, T. I.

    2013-12-01

    Coronal pseudo-streamers constitute a distinct type of magnetic structures, relatively less understood compared to helmet streamers and coronal holes. Studying the plasma dynamics in pseudo-streamers opens up an additional window into the larger problems of coronal heating and solar wind acceleration. Pseudo-streamers do not necessarily possess the low densities observed in coronal holes, making them almost indistinguishable from their surroundings in remote images of the corona. Thus locating pseudo-streamers requires a realistic 3D model of the magnetic field. In this work, we present results from the Alfven Wave Solar Model (AWSoM), a 3D magnetohydrodynamic model extending from the top of the chromosphere to 1AU, combined with a charge state evolution model (Michigan Ionization Code) for heavy ions. The MHD model is driven by Alfvenic turbulence, which is the sole source of heating, and is constrained by the observed photospheric magnetic field. The 3D nature of the MHD solution allows us to connect the plasma at any point at 1AU to its origin on the solar surface. We can then identify the coronal foot-point of a pseudo-streamer as well as its signature in in-situ observations at 1AU. The speed, electron temperature and density distribution along the selected magnetic field lines are extracted from the MHD solution and used as input to the charge state evolution model. The predicted charge state distribution will be used study the pseudo-streamer in two ways. First, the predicted frozen-in charge state distribution can be directly compared to in-situ measurements in the heliosphere made by the SWICS instrument on board ACE and Ulysses. Second, the charge state values predicted in the inner corona (below 1.5 solar radii) can be combined with the CHIANTI database and the 3D model's temperature and density distributions to calculate spectra line intensities and narrow-band images along any line of sight, to be compared with observations from SOHO, STEREO, Hinode

  5. FIRST-PRINCIPLES CALCULATIONS OF CHARGE STATES AND FORMATION ENERGIES OF Mg, Al, and Be TRANSMUTANTS IN 3C-SiC

    SciTech Connect

    Hu, Shenyang Y.; Setyawan, Wahyu; Jiang, Weilin; Henager, Charles H.; Kurtz, Richard J.

    2014-08-28

    The Vienna Ab-initio Simulation Package (VASP) is employed to calculate charge states and the formation energies of Mg, Al and Be transmutants at different lattice sites in 3C-SiC. The results provide important information on the dependence of the most stable charge state and formation energy of Mg, Al, Be and vacancies on electron potentials.

  6. Direct observation of charge state in the quasi-one-dimensional conductor Li0.9Mo6O17.

    PubMed

    Wu, Guoqing; Ye, Xiao-shan; Zeng, Xianghua; Wu, Bing; Clark, W G

    2016-01-01

    The quasi-one-dimensional conductor Li0.9Mo6O17 has been of great interest because of its unusual properties. It has a conducting phase with properties different from a simple Fermi liquid, a poorly understood "insulating" phase as indicated by a metal-"insulator" crossover (a mystery for over 30 years), and a superconducting phase which may involve spin triplet Cooper pairs as a three-dimensional (p-wave) non-conventional superconductor. Recent evidence suggests a density wave (DW) gapping regarding the metal-"insulator" crossover. However, the nature of the DW, such as whether it is due to the change in the charge state or spin state, and its relationship to the dimensional crossover and to the spin triplet superconductivity, remains elusive. Here by performing (7)Li-/(95)Mo-nuclear magnetic resonance (NMR) spectroscopy, we directly observed the charge state which shows no signature of change in the electric field gradient (nuclear quadrupolar frequency) or in the distribution of it, thus providing direct experimental evidences demonstrating that the long mysterious metal-"insulator" crossover is not due to the charge density wave (CDW) that was thought, and the nature of the DW gapping is not CDW. This discovery opens a parallel path to the study of the electron spin state and its possible connections to other unusual properties. PMID:26853454

  7. Charge 2e/3 Superconductivity and Topological Degeneracies without Localized Zero Modes in Bilayer Fractional Quantum Hall States.

    PubMed

    Barkeshli, Maissam

    2016-08-26

    It has been recently shown that non-Abelian defects with localized parafermion zero modes can arise in conventional Abelian fractional quantum Hall (FQH) states. Here we propose an alternate route to creating, manipulating, and measuring topologically protected degeneracies in bilayer FQH states coupled to superconductors, without the creation of localized parafermion zero modes. We focus mainly on electron-hole bilayers, with a ±1/3 Laughlin FQH state in each layer, with boundaries that are proximity coupled to a superconductor. We show that the superconductor induces charge 2e/3 quasiparticle-pair condensation at each boundary of the FQH state, and that this leads to (i) topologically protected degeneracies that can be measured through charge sensing experiments and (ii) a fractional charge 2e/3 ac Josephson effect. We demonstrate that an analog of non-Abelian braiding is possible, despite the absence of a localized zero mode. We discuss several practical advantages of this proposal over previous work, and also several generalizations. PMID:27610873

  8. Direct observation of charge state in the quasi-one-dimensional conductor Li0.9Mo6O17

    PubMed Central

    Wu, Guoqing; Ye, Xiao-shan; Zeng, Xianghua; Wu, Bing; Clark, W. G.

    2016-01-01

    The quasi-one-dimensional conductor Li0.9Mo6O17 has been of great interest because of its unusual properties. It has a conducting phase with properties different from a simple Fermi liquid, a poorly understood “insulating” phase as indicated by a metal-“insulator” crossover (a mystery for over 30 years), and a superconducting phase which may involve spin triplet Cooper pairs as a three-dimensional (p-wave) non-conventional superconductor. Recent evidence suggests a density wave (DW) gapping regarding the metal-“insulator” crossover. However, the nature of the DW, such as whether it is due to the change in the charge state or spin state, and its relationship to the dimensional crossover and to the spin triplet superconductivity, remains elusive. Here by performing 7Li-/95Mo-nuclear magnetic resonance (NMR) spectroscopy, we directly observed the charge state which shows no signature of change in the electric field gradient (nuclear quadrupolar frequency) or in the distribution of it, thus providing direct experimental evidences demonstrating that the long mysterious metal-“insulator” crossover is not due to the charge density wave (CDW) that was thought, and the nature of the DW gapping is not CDW. This discovery opens a parallel path to the study of the electron spin state and its possible connections to other unusual properties. PMID:26853454

  9. Absolute Identification by Relative Judgment

    ERIC Educational Resources Information Center

    Stewart, Neil; Brown, Gordon D. A.; Chater, Nick

    2005-01-01

    In unidimensional absolute identification tasks, participants identify stimuli that vary along a single dimension. Performance is surprisingly poor compared with discrimination of the same stimuli. Existing models assume that identification is achieved using long-term representations of absolute magnitudes. The authors propose an alternative…

  10. Be Resolute about Absolute Value

    ERIC Educational Resources Information Center

    Kidd, Margaret L.

    2007-01-01

    This article explores how conceptualization of absolute value can start long before it is introduced. The manner in which absolute value is introduced to students in middle school has far-reaching consequences for their future mathematical understanding. It begins to lay the foundation for students' understanding of algebra, which can change…

  11. A comparison between theoretical and experimental state-to-state charge transfer cross sections for H(+) + H2 at 20 eV: Evidence for quantum effects

    NASA Astrophysics Data System (ADS)

    Baer, Michael; Niedner, Gereon; Toennies, J. Peter

    1988-06-01

    A 3-D quantum mechanical close coupling study for the system H(+) +H2 is communicated. The quantum calculations, caried out in the finite order swiden approximation, show a better fit to previous experiments than the classical trajectory surface hopping (TSH) calculations, and provide direct evidence for the usefulness of a quantum treatment in predicting charge transfer (CT) processes. The total differential cross sections (summed over all final vibrational states) for the CT processes were calculated, in good agreement with experimental results. It is shown that a quantum mechanical treatment of both the inelastic and the charge transfer nonadiabatic processes is feasible and provides a superior description of the experiments compared to the TSH treatment. This demonstrates the importance of quantum effects in ion-molecule charge transfer.

  12. Tuning extreme ultraviolet emission for optimum coupling with multilayer mirrors for future lithography through control of ionic charge states

    SciTech Connect

    Ohashi, Hayato Higashiguchi, Takeshi Suzuki, Yuhei; Kawasaki, Masato; Li, Bowen; Dunne, Padraig; O'Sullivan, Gerry; Kanehara, Tatsuhiko; Aida, Yuya; Nakamura, Nobuyuki; Torii, Shuichi; Makimura, Tetsuya; Jiang, Weihua

    2014-01-21

    We report on the identification of the optimum plasma conditions for a laser-produced plasma source for efficient coupling with multilayer mirrors at 6.x nm for beyond extreme ultraviolet lithography. A small shift to lower energies of the peak emission for Nd:YAG laser-produced gadolinium plasmas was observed with increasing laser power density. Charge-defined emission spectra were observed in electron beam ion trap (EBIT) studies and the charge states responsible identified by use of the flexible atomic code (FAC). The EBIT spectra displayed a larger systematic shift of the peak wavelength of intense emission at 6.x nm to longer wavelengths with increasing ionic charge. This combination of spectra enabled the key ion stage to be confirmed as Gd{sup 18+}, over a range of laser power densities, with contributions from Gd{sup 17+} and Gd{sup 19+} responsible for the slight shift to longer wavelengths in the laser-plasma spectra. The FAC calculation also identified the origin of observed out-of-band emission and the charge states responsible.

  13. In situ X-ray near-edge absorption spectroscopy investigation of the state of charge of all-vanadium redox flow batteries.

    PubMed

    Jia, Chuankun; Liu, Qi; Sun, Cheng-Jun; Yang, Fan; Ren, Yang; Heald, Steve M; Liu, Yadong; Li, Zhe-Fei; Lu, Wenquan; Xie, Jian

    2014-10-22

    Synchrotron-based in situ X-ray near-edge absorption spectroscopy (XANES) has been used to study the valence state evolution of the vanadium ion for both the catholyte and anolyte in all-vanadium redox flow batteries (VRB) under realistic cycling conditions. The results indicate that, when using the widely used charge-discharge profile during the first charge process (charging the VRB cell to 1.65 V under a constant current mode), the vanadium ion valence did not reach V(V) in the catholyte and did not reach V(II) in the anolyte. Consequently, the state of charge (SOC) for the VRB cell was only 82%, far below the desired 100% SOC. Thus, such incompletely charged mix electrolytes results in not only wasting the electrolytes but also decreasing the cell performance in the following cycles. On the basis of our study, we proposed a new charge-discharge profile (first charged at a constant current mode up to 1.65 V and then continuously charged at a constant voltage mode until the capacity was close to the theoretical value) for the first charge process that achieved 100% SOC after the initial charge process. Utilizing this new charge-discharge profile, the theoretical charge capacity and the full utilization of electrolytes has been achieved, thus having a significant impact on the cost reduction of the electrolytes in VRB. PMID:25191695

  14. Preserving Charge and Oxidation State of Au(III) Ions in an Agent-Functionalized Nanocrystal Model System

    PubMed Central

    2011-01-01

    Supporting functional molecules on crystal facets is an established technique in nanotechnology. To preserve the original activity of ionic metallorganic agents on a supporting template, conservation of the charge and oxidation state of the active center is indispensable. We present a model system of a metallorganic agent that, indeed, fulfills this design criterion on a technologically relevant metal support with potential impact on Au(III)-porphyrin-functionalized nanoparticles for an improved anticancer-drug delivery. Employing scanning tunneling microscopy and -spectroscopy in combination with photoemission spectroscopy, we clarify at the single-molecule level the underlying mechanisms of this exceptional adsorption mode. It is based on the balance between a high-energy oxidation state and an electrostatic screening-response of the surface (image charge). Modeling with first principles methods reveals submolecular details of the metal–ligand bonding interaction and completes the study by providing an illustrative electrostatic model relevant for ionic metalorganic agent molecules, in general. PMID:21736315

  15. Charge-state-dependent collisional energy-loss straggling of swift ions in a degenerate electron gas

    NASA Astrophysics Data System (ADS)

    Nagy, I.; Aldazabal, I.

    2009-12-01

    In order to characterize the statistical aspect of the energy loss in particle penetration, Bohr developed a kinetic theory and applied it to a beam of fast α particles interacting with free electrons. The present study rests on this classical theory of collisional straggling, and it is implemented by using a partially screened Coulomb potential to model the electron-projectile interaction. The deflection angle of electron scattering in this long-ranged field is calculated analytically within the framework of classical mechanics. The transport fluctuation cross section, which is the basic quantity to the collisional straggling in Bohr’s modeling, is determined numerically. By varying the number of bound electrons around the swift He ions, the effect of prefixed charge states in the collisional energy-loss straggling is quantified. An incoherent weighted summation of different fixed charge-state channels is discussed as well, by using normalized probabilities.

  16. Equilibrium and non-equilibrium charge-state distributions of 2.0 MeV/u carbon ions passing through carbon foils

    NASA Astrophysics Data System (ADS)

    Imai, M.; Sataka, M.; Matsuda, M.; Okayasu, S.; Kawatsura, K.; Takahiro, K.; Komaki, K.; Shibata, H.; Nishio, K.

    2015-07-01

    Both equilibrium and non-equilibrium charge-state distributions were studied experimentally for 2.0 MeV/u carbon ions after passing through carbon foils. Measured charge-state distribution established the equilibrium at a target thickness of 10 μg/cm2 and this remained unchanged until a maximum target thickness of 98 μg/cm2. The equilibrium charge-state distribution, the equilibrium mean charge-state, and the width and skewness of the equilibrium distribution were compared with predictions using existing semi-empirical formulae as well as simulation results, including the ETACHA code. It was found that charge-state distributions, mean charge states, and distribution widths for C2+, C3+, and C4+ incident ions merged into quasi-equilibrium values at a target thickness of 5.7 μg/cm2 in the pre-equilibrium region and evolved simultaneously to the 'real equilibrium' values for all of the initial charge states, including C5+ and C6+ ions, as previously demonstrated for sulfur projectile ions at the same velocity (Imai et al., 2009). Two kinds of simulation, ETACHA and solution of rate equations taking only single electron transfers into account, were used, and both of them reproduced the measured charge evolution qualitatively. The quasi-equilibrium behavior could be reproduced with the ETACHA code, but not with solution of elementary rate equations.

  17. (Photoinduced charge separation in solid-state and molecular systems: Year three progress report)

    SciTech Connect

    Bocarsly, A.B.

    1991-01-01

    Our goal is to understand the role of intrinsic cyanometalate overlayers in modulating interfacial photoinduced charge transfer processes occurring at the cadmium chalconide/aqueous ferri-ferrocyanide interface. To accomplish this goal, detailed structural and charge transfer studies of (CdFe(CN){sub 6}){sup 2-/1-} overlayers generated either intrinsically via photoelectrochemistry at the illuminated CdX/(Fe(CN){sub 6}){sup 4-/32} (X=S or Se) interface, or synthesized as chemical modification layers on inert metal electrodes have been undertaken. From these studies, a picture has evolved which directly links charge transfer mediated cation intercalation processes to surface overlayer crystal structure, and overlayer structure to critical charge transfer parameters. We have discovered that a photoelectrochemical cell of composition n-CdSe/(1M) KCN provides a relatively unique environment for testing the dynamic effects of chemisorption processes on heterogeneous charge transfer at the semiconductor-liquid junction. Thus, our retrospective studies have provided for new insight into semiconductor photochemistry. In parallel with our photoelectrochemical projects we have also introduced work on the spatially resolved photodeposition of platinum metal on nonconducting and semiconducting substrates. This chemistry provides new opportunities for the design of semiconductor (or insulator)-metal heterostructures which have applications in solar energy conversion.

  18. EVOLUTION OF THE RELATIONSHIPS BETWEEN HELIUM ABUNDANCE, MINOR ION CHARGE STATE, AND SOLAR WIND SPEED OVER THE SOLAR CYCLE

    SciTech Connect

    Kasper, J. C.; Stevens, M. L.; Korreck, K. E.; Maruca, B. A.; Kiefer, K. K.; Schwadron, N. A.; Lepri, S. T.

    2012-02-01

    The changing relationships between solar wind speed, helium abundance, and minor ion charge state are examined over solar cycle 23. Observations of the abundance of helium relative to hydrogen (A{sub He} {identical_to} 100 Multiplication-Sign n{sub He}/n{sub H}) by the Wind spacecraft are used to examine the dependence of A{sub He} on solar wind speed and solar activity between 1994 and 2010. This work updates an earlier study of A{sub He} from 1994 to 2004 to include the recent extreme solar minimum and broadly confirms our previous result that A{sub He} in slow wind is strongly correlated with sunspot number, reaching its lowest values in each solar minima. During the last minimum, as sunspot numbers reached their lowest levels in recent history, A{sub He} continued to decrease, falling to half the levels observed in slow wind during the previous minimum and, for the first time observed, decreasing even in the fastest solar wind. We have also extended our previous analysis by adding measurements of the mean carbon and oxygen charge states observed with the Advanced Composition Explorer spacecraft since 1998. We find that as solar activity decreased, the mean charge states of oxygen and carbon for solar wind of a given speed also fell, implying that the wind was formed in cooler regions in the corona during the recent solar minimum. The physical processes in the coronal responsible for establishing the mean charge state and speed of the solar wind have evolved with solar activity and time.

  19. A donor-acceptor triptycene-coumarin hybrid dye featuring a charge separated excited state and AIE properties.

    PubMed

    Qian, Rui; Tong, Hongjuan; Huang, Cui; Li, Junhao; Tang, Yun; Wang, Rui; Lou, Kaiyan; Wang, Wei

    2016-06-14

    A triptycene-coumarin hybrid dye DCT-1 with a 1,4-dimethoxybenzene group as the electron donor and a coumarin fluorophore as the acceptor on the separated fins of a triptycene was synthesized. DCT-1 features a charge separated excited state with emissions sensitive to solvent polarities. Moreover, DCT-1 also exhibits aggregation-induced emission properties in water with excellent photostability and pH-stability for potential cell imaging applications. PMID:27186970

  20. Atomistic simulation of charge effects: From tunable thin film growth to isolation of surface states with spin-orbit coupling

    NASA Astrophysics Data System (ADS)

    Ming, Wenmei

    This dissertation revitalizes the importance of surface charge effects in semiconductor nanostructures, in particular in the context of thin film growth and exotic electronic structures under delicate spin-orbit coupling. A combination of simulation techniques, including density functional theory calculation, kinetic Monte Carlo method, nonequilibrium Green's function method, and tight binding method, were employed to reveal the underlying physical mechanisms of four topics: (1) Effects of Li doping on H-diffusion in MgH 2 for hydrogen storage. It addresses both the effect of Fermi level tuning by charged dopant and the effect of dopant-defect interaction, and the latter was largely neglected in previous works; (2) Tuning nucleation density of the metal island with charge doping of the graphene substrate. It is the first time that the surface charge doping effect is proposed and studied as an effective approach to tune the kinetics of island nucleation at the early stage of thin film growth; (3) Complete isolation of Rashba surface states on the saturated semiconductor surface. It shows that the naturally saturated semiconductor surface of InSe(0001) with Au single layer film provides a mechanism for the formation of Rashba states with large spin splitting; it opens up an innovative route to obtaining ideal Rashba states without the overwhelming bulk spin-degenerate carriers in spin-dependent transport; (4) Formation of large band gap quantum spin Hall state on Si surface. This study reveals the importance of atomic orbital composition in the formation of a topological insulator, and shows promisingly the possible integration of topological insulator technology into Si-based modern electronic devices.

  1. Failure mode of valve-regulated lead-acid batteries under high-rate partial-state-of-charge operation

    NASA Astrophysics Data System (ADS)

    Lam, L. T.; Haigh, N. P.; Phyland, C. G.; Urban, A. J.

    Within the next decade, there will be major changes in automotive technology with the introduction of several new features which will increase significantly the on-board power requirements. This high power demand is beyond the capability of present 14 V alternators and thus a 42 V power network is to be adopted. The new 'PowerNet' requires the lead-acid battery to be capable of providing a large number of shallow discharge-charge cycles at a high rate. High-rate discharge is necessary for engine cranking and power assist, while high-rate charge is associated with regenerative braking. The battery will operate at these high rates in a partial-state-of-charge condition, so-called HRPSoC duty. Under simulated HRPSoC duty, it is found that the valve-regulated lead-acid (VRLA) battery fails prematurely due to the progressive accumulation of lead sulfate mainly on the surfaces of the negative plates. This is because the lead sulfate cannot be converted efficiently back to sponge lead during charging either from the engine or from regenerative braking. Eventually, the layer of lead sulfate develops to such extent that the effective surface area of the plate is reduced markedly and the plate can no longer deliver the high cranking-current demanded by the automobile. A mechanistic analysis of battery operation during HRPSoC duty shows that high-rate discharge is the key factor responsible for the build-up of the lead sulfate layer. Such discharge causes a compact layer of tiny lead sulfate crystals to form on the surface of the negative plate and subsequent charging gives rise to an early evolution of hydrogen. Hydrogen evolution is further exacerbated when a high charging current is used.

  2. Signature OH Absorption Spectrum from cluster Models of Solvation: a solvent-to-solute charge transfer state

    SciTech Connect

    Tsai, Ming Kang; Kowalski, Karol; Valiev, Marat; Dupuis, Michel

    2007-10-25

    ab initio electronic structure theories applied to cluster models support the characterization of the signature of the OH absorption spectrum to be a solvent-to-solute charge transfer state affected by the hydrogen bonding environment in the region of 250 nm (calculated). The vertical excited states were calculated at the TDDFT level of theory with using OH(H2O)n clusters (n = 0-7, 16) with companion calculations at the EOM-CCSD level of theory for n ≤ 7. An intense solvent-to-solute charge transfer transition was calculated for n = 16 cluster where the donor and acceptor molecular orbitals are in favorable alignment. In the other smaller clusters the transitions in this region were found to be weak. The present findings are consistent with the experimental absorption at 230 nm suggested to be a solvent-to-solute charge transfer and provide insight into the electronic states and orbitals that give rise to the intensity of the band. This work was supported by the U.S. Department of Energy's (DOE) Office of Basic Energy Sciences, Chemical Sciences program, and was performed in part using the Molecular Science Computing Facility (MSCF) in the William R. Wiley Environmental Molecular Sciences Laboratory, a DOE national scientific user facility located at the Pacific Northwest National Laboratory (PNNL). PNNL is operated by Battelle for DOE.

  3. Effective Control of the Charge and Magnetic States of Transition-Metal Atoms on Single-Layer Boron Nitride

    SciTech Connect

    Huang, B.; Xiang, H. J.; Yu, J. J.; Wei, S. H.

    2012-05-18

    Developing approaches to effectively control the charge and magnetic states is critical to the use of magnetic nanostructures in quantum information devices but is still challenging. Here we suggest that the magnetic and charge states of transition-metal (TM) doped single-layer boron-nitride (SLBN) systems can be easily controlled by the (internal) defect engineering and (external) electric fields (E{sub ext}). The relative positions and symmetries of the in-gap levels induced by defect engineering and the TM d-orbital energy levels effectively determine the charge states and magnetic properties of the TM/SLBN system. Remarkably, the application of an E{sub ext} can easily control the size of the crystal field splitting of the TM d orbitals and thus, leading to the spin crossover in TM/SLBN, which could be used as E{sub ext}-driven nonvolatile memory devices. Our conclusion obtained from TM/SLBN is valid generally in other TM adsorbed layered semiconductors.

  4. Spatially resolved charge-state and current-density distributions at the extraction of an electron cyclotron resonance ion source

    SciTech Connect

    Panitzsch, Lauri; Peleikis, Thies; Stalder, Michael; Wimmer-Schweingruber, Robert F.

    2011-09-15

    In this paper we present our measurements of charge-state and current-density distributions performed in very close vicinity (15 mm) of the extraction of our hexapole geometry electron cyclotron resonance ion source. We achieved a relatively high spatial resolution reducing the aperture of our 3D-movable extraction (puller) electrode to a diameter of only 0.5 mm. Thus, we are able to limit the source of the extracted ion beam to a very small region of the plasma electrode's hole (O = 4 mm) and therefore to a very small region of the neutral plasma sheath. The information about the charge-state distribution and the current density in the plane of the plasma electrode at each particular position is conserved in the ion beam. We determined the total current density distribution at a fixed coaxial distance of only 15 mm to the plasma electrode by remotely moving the small-aperture puller electrode which contained a dedicated Faraday cup (FC) across the aperture of the plasma electrode. In a second measurement we removed the FC and recorded m/q-spectra for the different positions using a sector magnet. From our results we can deduce that different ion charge-states can be grouped into bloated triangles of different sizes and same orientation at the extraction with the current density peaking at centre. This confirms observations from other groups based on simulations and emittance measurements. We present our measurements in detail and discuss possible systematic errors.

  5. Charge state, angular distribution, and kinetic energy of ions from multicomponent-cathodes in vacuum arc devices

    SciTech Connect

    Nikolaev, A. G. Savkin, K. P.; Yushkov, G. Yu.; Frolova, V. P.; Barengolts, S. A.

    2014-12-07

    We present research results on vacuum arc plasma produced with multicomponent cathode made of several different elements. The ion mass-to-charge-state spectra of the plasmas were studied by time-of-flight spectrometry. The angular distributions of different ion species were measured, and the kinetic energy of their directed (streaming) motion was determined. It is shown that the fractional composition of ions of different cathode components in the plasma flow from the cathode spot closely matches the fractional content of these components in the composite cathode. The charge states of ions of the various cathode components are determined by the average electron temperature in the cathode spot plasma. The angular distribution of lower mass ions in the plasma from a multicomponent cathode is less isotropic and broader than for the plasma from a single-component cathode of the same light element. The directed kinetic energies of the ions of the different components for plasma from a multicomponent cathode are lower for lighter elements and greater for heavier elements compared to the ion directed energy for plasmas from single-component cathodes made of the same materials. The physical processes responsible for these changes in the ion charge states in multicomponent-cathode vacuum arc plasma are discussed.

  6. A Statistical Study of the Average Iron Charge State Distributions inside Magnetic Clouds for Solar Cycle 23

    NASA Astrophysics Data System (ADS)

    Song, H. Q.; Zhong, Z.; Chen, Y.; Zhang, J.; Cheng, X.; Zhao, L.; Hu, Q.; Li, G.

    2016-06-01

    Magnetic clouds (MCs) are the interplanetary counterparts of coronal magnetic flux ropes. They can provide valuable information regarding flux rope characteristics at their eruption stage in the corona, which is unable to be explored in situ at present. In this paper, we make a comprehensive survey of the average iron charge-state (< Q> {Fe}) distributions inside 96 MCs for solar cycle 23 using Advanced Composition Explorer (ACE) data. Since the < Q> {Fe} in the solar wind are typically around 9+ to 11+, the Fe charge state is defined as being high when the < Q> {Fe} is larger than 12+, which implies the existence of a considerable amount of Fe ions with high charge states (e.g., ≥16+). The statistical results show that the < Q> {Fe} distributions of 92 (∼96%) MCs can be classified into four groups with different characteristics. In group A (11 MCs), the < Q> {Fe} shows a bi-modal distribution with both peaks being higher than 12+. Group B (4 MCs) presents a unimodal distribution of < Q> {Fe}, with its peak being higher than 12+. In groups C (29 MCs) and D (48 MCs), the < Q> {Fe} remains higher and lower than 12+ throughout ACE’s passage through the MC, respectively. Possible explanations of these distributions are discussed.

  7. Improvement of Charge Collection and Performance Reproducibility in Inverted Organic Solar Cells by Suppression of ZnO Subgap States.

    PubMed

    Wu, Bo; Wu, Zhenghui; Yang, Qingyi; Zhu, Furong; Ng, Tsz-Wai; Lee, Chun-Sing; Cheung, Sin-Hang; So, Shu-Kong

    2016-06-15

    Organic solar cells (OSCs) with inverted structure usually exhibit higher power conversion efficiency (PCE) and are more stable than corresponding devices with regular configuration. Indium tin oxide (ITO) surface is often modified with solution-processed low work function metal oxides, such as ZnO, serving as the transparent cathode. However, the defect-induced subgap states in the ZnO interlayer hamper the efficient charge collection and the performance reproducibility of the OSCs. In this work, we demonstrate that suppression of the ZnO subgap states by modification of its surface with an ultrathin Al layer significantly improves the charge extraction and performance reproducibility, achieving PCE of 8.0%, which is ∼15% higher than that of a structurally identical control cell made with a pristine ZnO interlayer. Light intensity-dependent current density-voltage characteristic, photothermal deflection spectroscopy, and X-ray photoelectron spectroscopy measurements point out the enhancement of charge collection efficiency at the organic/cathode interface, due to the suppression of the subgap states in the ZnO interlayer. PMID:27224960

  8. Persistent State-of-Charge Heterogeneity in Relaxed, Partially Charged Li1- x Ni1/3 Co1/3 Mn1/3 O2 Secondary Particles.

    PubMed

    Gent, William E; Li, Yiyang; Ahn, Sungjin; Lim, Jongwoo; Liu, Yijin; Wise, Anna M; Gopal, Chirranjeevi Balaji; Mueller, David N; Davis, Ryan; Weker, Johanna Nelson; Park, Jin-Hwan; Doo, Seok-Kwang; Chueh, William C

    2016-08-01

    Ex situ transmission X-ray microscopy reveals micrometer-scale state-of-charge heterogeneity in solid-solution Li1- x Ni1/3 Co1/3 Mn1/3 O2 secondary particles even after extensive relaxation. The heterogeneity generates overcharged domains at the cutoff voltage, which may accelerate capacity fading and increase impedance with extended cycling. It is proposed that optimized secondary structures can minimize the state-of-charge heterogeneity by mitigating the buildup of nonuniform internal stresses associated with volume changes during charge. PMID:27187238

  9. Regional disparities in hospitalization charges for patients undergoing craniotomy for tumor resection in New York State: correlation with outcomes.

    PubMed

    Missios, Symeon; Bekelis, Kimon

    2016-06-01

    There is increasing regulatory pressure for cost containment in neuro-oncology, and rationalization of the observed regional disparities. We investigated the presence of such disparities in New York State and examined the impact of risk adjustment on the magnitude of this variation. We performed a cohort study involving patients with brain tumors (gliomas, metastases, or meningiomas), who underwent craniotomy for resection from 2009 to 2013, and were registered in the Statewide Planning and Research Cooperative System (SPARCS) database. A linear regression model was utilized for risk-adjustment of inpatient charges using socioeconomic factors and comorbidities. Hospitals with fewer than 20 craniotomies were excluded. 13,535 patients underwent treatment, including 5032 (37.2 %) gliomas, 4858 (35.9 %) metastases, and 3645 (26.9 %) meningiomas. Unadjusted median hospitalization charges ranged from $22,954 to $177,398 at the hospital level, and $30,086 to $159,281 at the county level. Despite extensive risk-adjustment we observed persistent disparities with median hospitalization charges ranging from $40,455 to $124,691 at the hospital level, and $53,999 to $94,844 at the county level. Analysis of variance (ANOVA) demonstrated that these disparities were significant at the facility and the county level (P < 0.0001). Increased charges were not associated with shorter LOS (r = 0.10, P = 0.41), or lower rates of death (r = 0.09, P = 0.46), and unfavorable discharge (r = 0.24, P = 0.06). Using a comprehensive all-payer cohort of patients with brain tumors in New York State we identified wide disparities at the hospital and the county level despite comprehensive risk-adjustment. Increased charges were not associated with shorter LOS, or lower rates of death and unfavorable discharge. PMID:27072560

  10. Influence of bias voltage and temperature on charge transfer states in organic photovoltaic and electroluminescent integrated device

    SciTech Connect

    Huang, Jiang; Wang, Hanyu; Qi, Yige; Yu, Junsheng

    2014-05-19

    Based on the organic photovoltaic (PV) and electroluminescent (EL) integrated device with a structure of SubPc/C{sub 60} heterojunction, both PV and EL properties of charge transfer states (CTSs) were simultaneously investigated. By means of infrared and visible isolating method, the EL characteristics of CTSs and singlet-triplet excitons were separated, and their properties dependence on bias voltage and temperature was analyzed by introducing modified diode models. From the simulation on the emissive photons from CTSs, the temperature independent parameters of CTSs were extracted, which have close relationship with thermal activation energy and effective emissive state number of CTSs at the SubPc/C{sub 60} interface.

  11. Absolute Integral Cross Sections for the State-selected Ion–Molecule Reaction N2+(X2Σg+ v+ = 0–2) + C2H2 in the Collision Energy Range of 0.03–10.00 eV

    NASA Astrophysics Data System (ADS)

    Xu, Yuntao; Xiong, Bo; Chung Chang, Yih; Ng, C. Y.

    2016-08-01

    Using the vacuum ultraviolet laser pulsed field ionization-photoion source, together with the double-quadrupole–double-octopole mass spectrometer developed in our laboratory, we have investigated the state-selected ion–molecule reaction {{{{N}}}2}+({X}2{{{{Σ }}}{{g}}}+; v + = 0–2, N+ = 0–9) + C2H2, achieving high internal-state selectivity and high kinetic energy resolution for reactant {{{{N}}}2}+ ions. The charge transfer (CT) and hydrogen-atom transfer (HT) channels, which lead to the respective formation of product {{{C}}}2{{{{H}}}2}+ and N2H+ ions, are observed. The vibrationally selected absolute integral cross sections for the CT [σ CT(v +)] and HT [[σ HT(v +)] channels obtained in the center-of-mass collision energy (E cm) range of 0.03–10.00 eV reveal opposite E cm dependences. The σ CT(v +) is found to increase as E cm is decreased, and is consistent with the long-range exothermic CT mechanism, whereas the E cm enhancement observed for the σ HT(v +) suggests effective coupling of kinetic energy to internal energy, enhancing the formation of N2H+. The σ HT(v +) curve exhibits a step at E cm = 0.70–1.00 eV, suggesting the involvement of the excited {{{C}}}2{{{{H}}}2}+({A}2{{{{Σ }}}{{g}}}+) state in the HT reaction. Contrary to the strong E cm dependences for σ CT(v +) and σ HT(v +), the effect of vibrational excitation of {{{{N}}}2}+ on both the CT and HT channels is marginal. The branching ratios and cross sections for the CT and HT channels determined in the present study are useful for modeling the atmospheric compositions of Saturn's largest moon, Titan. These cross sections and branching ratios are also valuable for benchmarking theoretical calculations on chemical dynamics of the titled reaction.

  12. Fe, O, and C Charge States Associated with Quiescent Versus Active Current Sheets in the Solar Wind

    NASA Technical Reports Server (NTRS)

    Suess, S. T.; Ko, Y.-K.; vonSteiger, R.

    2008-01-01

    Ulysses MAG data were used to locate the heliospheric current sheet in data from 1991 through 2006. The purpose was to characterize typical charge states for Fe, O, and C in the vicinity of the current sheet and provide insight into the physical sources for these charge states in the corona. A study of He/H around the current sheets has led to a clear distinction between quiescent current sheets at times of low solar activity and active current sheets associated with magnetic clouds (and, presumably, ICMES). It has been shown that high ionization state Fe is produced in the corona in current sheets associated with CMEs through spectroscopic observations of the corona and through in situ detection at Ulysses. Here we show that the ionization state of Fe is typically only enhanced around active current sheets while the ionization states of O and C are commonly enhanced around both quiescent and active current sheets. This is consistent with UV coronal spectroscopy, which has shown that reconnection in current sheets behind CMEs leads to high temperatures not typically seen above quiet streamers.

  13. 2D coherent charge transport in highly ordered conducting polymers doped by solid state diffusion.

    PubMed

    Kang, Keehoon; Watanabe, Shun; Broch, Katharina; Sepe, Alessandro; Brown, Adam; Nasrallah, Iyad; Nikolka, Mark; Fei, Zhuping; Heeney, Martin; Matsumoto, Daisuke; Marumoto, Kazuhiro; Tanaka, Hisaaki; Kuroda, Shin-Ichi; Sirringhaus, Henning

    2016-08-01

    Doping is one of the most important methods to control charge carrier concentration in semiconductors. Ideally, the introduction of dopants should not perturb the ordered microstructure of the semiconducting host. In some systems, such as modulation-doped inorganic semiconductors or molecular charge transfer crystals, this can be achieved by spatially separating the dopants from the charge transport pathways. However, in conducting polymers, dopants tend to be randomly distributed within the conjugated polymer, and as a result the transport properties are strongly affected by the resulting structural and electronic disorder. Here, we show that in the highly ordered lamellar microstructure of a regioregular thiophene-based conjugated polymer, a small-molecule p-type dopant can be incorporated by solid state diffusion into the layers of solubilizing side chains without disrupting the conjugated layers. In contrast to more disordered systems, this allows us to observe coherent, free-electron-like charge transport properties, including a nearly ideal Hall effect in a wide temperature range, a positive magnetoconductance due to weak localization and the Pauli paramagnetic spin susceptibility. PMID:27159015

  14. Sign inversion of surface stress-charge response of bulk nanoporous nickel actuators with different surface states.

    PubMed

    Bai, Qingguo; Si, Conghui; Zhang, Jie; Zhang, Zhonghua

    2016-07-20

    The surface stress-charge coefficient, ζ, is a fundamental material parameter and reflects the response of surface stress to the change of superficial charge. The sign and the quantity of ζ play a crucial role in electrochemically induced actuation of nanostructured metals. Here, for the first time, we address the electrochemical actuation and the associated stress-charge coefficients of bulk nanoporous nickel (np-Ni) in both strongly (NaOH) and weakly (NaF) adsorbed electrolytes. The results reveal a normal negative value of ζ for the np-Ni with the clean surface, and unusual positive values of ζ for the oxide-covered surface. Interestingly, the oxidized np-Ni cannot recover the conventional negative value of ζ even in the cathodic potential window. Moreover, the reversible strain amplitude and the involved charge are quite different in distinct potential windows (the same electrolyte) or in different electrolytes (strongly or weakly adsorbed). In addition, density functional theory (DFT) calculations have been performed to understand the electrochemical actuation behaviors of the np-Ni with different surface states. In some aspects, the scenario of the np-Ni indeed differs from that of nanoporous noble metals like Au or Pt. Our findings provide useful information on understanding the electrochemical actuation of nanostructured metals, and novel actuators or sensors could be developed based upon earth-abundant metals like Ni, Co, and so forth. PMID:27389658

  15. Charge transport of graphene ferromagnetic-insulator-superconductor junction with pairing state of broken time reversal symmetry

    NASA Astrophysics Data System (ADS)

    Hajati, Yaser

    2015-04-01

    We investigate the charge transport through a graphene-based ferromagnetic-insulator-superconductor junction with a broken time reversal symmetry (BTRS) of dx2-y2 + is and dx2-y2 + idxy superconductor using the extended Blonder-Tinkham-Klapwijk formalism. Our analysis have shown several charateristics in this junction, providing a useful probe to understand the role of the order parameter symmetry in the superconductivity. We find that the presence of the BTRS (X) state in the superconductor region has a strong effect on the tunneling conductance curves which leads to a decrease in the height of the zero-bias conductance peak (ZBCP). In particular, we show that the magnitude of the superconducting proximity effect depends to a great extent on X and by increasing X, the zero-bias charge conductance oscillations with respect to the rotation angle β are suppressed. In addition, we find that at the maximum rotation angle β = π/4, introducing BTRS in the FIS junction causes oscillatory behavior of the zero-bias charge conductance with the barrier strength (χG) by a period of π and by approaching the X to 1, the amplitude of charge conductance oscillations increases. This behavior is drastically different from none BTRS similar graphene junctions. At last, we suggest an experimental setup for verifying our predicted effects.

  16. Charge state control in single InAs/GaAs quantum dots by external electric and magnetic fields

    SciTech Connect

    Tang, Jing; Cao, Shuo; Gao, Yunan; Sun, Yue; Jin, Kuijuan; Xu, Xiulai; Geng, Weidong; Williams, David A.

    2014-07-28

    We report a photoluminescence (PL) spectroscopy study of charge state control in single self-assembled InAs/GaAs quantum dots by applying electric and/or magnetic fields at 4.2 K. Neutral and charged exciton complexes were observed under applied bias voltages from −0.5 V to 0.5 V by controlling the carrier tunneling. The highly negatively charged exciton emission becomes stronger with increasing pumping power, arising from the fact that electrons have a smaller effective mass than holes and are more easily captured by the quantum dots. The integrated PL intensity of negatively charged excitons is affected significantly by a magnetic field applied along the sample growth axis. This observation is explained by a reduction in the electron drift velocity caused by an applied magnetic field, which increases the probability of non-resonantly excited electrons being trapped by localized potentials at the wetting layer interface, and results in fewer electrons distributed in the quantum dots. The hole drift velocity is also affected by the magnetic field, but it is much weaker.

  17. Absolute photoionization cross sections of atomic oxygen

    NASA Technical Reports Server (NTRS)

    Samson, J. A. R.; Pareek, P. N.

    1985-01-01

    The absolute values of photoionization cross sections of atomic oxygen were measured from the ionization threshold to 120 A. An auto-ionizing resonance belonging to the 2S2P4(4P)3P(3Do, 3So) transition was observed at 479.43 A and another line at 389.97 A. The experimental data is in excellent agreement with rigorous close-coupling calculations that include electron correlations in both the initial and final states.

  18. Absolute photoionization cross sections of atomic oxygen

    NASA Technical Reports Server (NTRS)

    Samson, J. A. R.; Pareek, P. N.

    1982-01-01

    The absolute values of photoionization cross sections of atomic oxygen were measured from the ionization threshold to 120 A. An auto-ionizing resonance belonging to the 2S2P4(4P)3P(3Do, 3So) transition was observed at 479.43 A and another line at 389.97 A. The experimental data is in excellent agreement with rigorous close-coupling calculations that include electron correlations in both the initial and final states.

  19. CHARGE IMBALANCE

    SciTech Connect

    Clarke, John

    1980-09-01

    The purpose of this article is to review the theory of charge imbalance, and to discuss its relevance to a number of experimental situations. We introduce the concepts of quasiparticle charge and charge imbalance, and discuss the generation and detection of charge imbalance by tunneling. We describe the relaxation of the injected charge imbalance by inelastic scattering processes, and show how the Boltzmann equation can be solved to obtain the steady state quasiparticle distribution and the charge relaxation rate. Details are given of experiments to measure charge imbalance and the charge relaxation rate when inelastic scattering is the predominant relaxation mechanism. Experiments on and theories of other charge relaxation mechanisms are discussed, namely relaxation via elastic scattering in the presence of energy gap anisotropy, or in the presence of a pair breaking mechanism such as magnetic impurities or an applied supercurrent or magnetic field. We describe three other situations in which charge imbalance occurs, namely the resistance of the NS interface, phase slip centers, and the flow of a supercurrent in the presence of a temperature gradient.

  20. Effect of the redox state of QB on electric field-induced charge recombination in Photosystem II.

    PubMed

    Hemelrijk, P W; van Gorkom, H J

    1996-05-01

    Electric field-induced charge recombination in Photosystem II (PS II) was studied in osmotically swollen spinach chloroplasts ('blebs') by measurement of the concomitant chlorophyll luminescence emission (electroluminescence). A pronounced dependence on the redox state of the two-electron gate QB was observed and the earlier failure to detect it is explained. The influence of the QB/QB (-) oscillation on electroluminescence was dependent on the redox state of the oxygen evolving complex; at times around one millisecond after flash illumination a large effect was observed in the states S2 and S3, but not in the state 'S4' (actually Z(+)S3). The presence of the oxidized secondary electron donor, tyrosine Z(+), appeared to prevent expression of the QB/QB (-) effect on electroluminescence, possibly because this effect is primarily due to a shift of the redox equilibrium between Z/Z(+) and the oxygen evolving complex. PMID:24271299