Science.gov

Sample records for ion charge states

  1. 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)

  2. Ion-Ion Reactions with Fixed-Charge Modified Proteins to Produce Ions in a Single, Very High Charge State

    PubMed Central

    Frey, Brian L.; Krusemark, Casey J.; Ledvina, Aaron R.; Coon, Joshua J.; Belshaw, Peter J.

    2008-01-01

    Electrospray ionization (ESI) of denatured proteins produces a mass spectrum with a broad distribution of multiply charged ions. Attaching fixed positive charges, specifically quaternary ammonium groups, to proteins at their carboxylic acid groups generates substantially higher charge states compared to the corresponding unmodified proteins in positive-mode ESI. Ion-ion reactions of these modified proteins with reagent anions leads to charge reduction by proton transfer. These proton transfer reactions cannot remove charge from the quaternary ammonium groups, which do not have a proton to transfer to the anion. Thus, one might expect charge reduction to stop at a single charge state equal to the number of fixed charges on the modified protein. However, ion-ion reactions yield charge states lower than this number of fixed charges due to anion attachment (adduction) to the proteins. Charge reduction via ion-molecule reactions involving gas-phase bases also give adducts on the modified protein ions in low charge states. Such adducts are avoided by keeping the ions in charge states well above the number of fixed charges. In the present work protein ions were selectively “parked” within an ion trap mass spectrometer in a high charge state by mild radiofrequency excitation that dramatically slows their ion-ion reaction rate—a technique termed “ion parking”. The combination of ion parking with the fixed-charge modified proteins permits generation of a large population of ions in a single, very high charge state. PMID:19802328

  3. Ion-Ion Reactions with Fixed-Charge Modified Proteins to Produce Ions in a Single, Very High Charge State.

    PubMed

    Frey, Brian L; Krusemark, Casey J; Ledvina, Aaron R; Coon, Joshua J; Belshaw, Peter J; Smith, Lloyd M

    2008-10-01

    Electrospray ionization (ESI) of denatured proteins produces a mass spectrum with a broad distribution of multiply charged ions. Attaching fixed positive charges, specifically quaternary ammonium groups, to proteins at their carboxylic acid groups generates substantially higher charge states compared to the corresponding unmodified proteins in positive-mode ESI. Ion-ion reactions of these modified proteins with reagent anions leads to charge reduction by proton transfer. These proton transfer reactions cannot remove charge from the quaternary ammonium groups, which do not have a proton to transfer to the anion. Thus, one might expect charge reduction to stop at a single charge state equal to the number of fixed charges on the modified protein. However, ion-ion reactions yield charge states lower than this number of fixed charges due to anion attachment (adduction) to the proteins. Charge reduction via ion-molecule reactions involving gas-phase bases also give adducts on the modified protein ions in low charge states. Such adducts are avoided by keeping the ions in charge states well above the number of fixed charges. In the present work protein ions were selectively "parked" within an ion trap mass spectrometer in a high charge state by mild radiofrequency excitation that dramatically slows their ion-ion reaction rate-a technique termed "ion parking". The combination of ion parking with the fixed-charge modified proteins permits generation of a large population of ions in a single, very high charge state.

  4. Solar wind ion composition and charge states

    NASA Technical Reports Server (NTRS)

    vonSteiger, R.

    1995-01-01

    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. We 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, we 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, we 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.

  5. Charge-state measurements of backscattered ions from Au films

    SciTech Connect

    Arafah, D.; Meyer, J.D.; Sharabati, H.; Mahmoud, A.

    1989-04-15

    A small electrostatic accelerator (65 kV) was built as a postaccelerator for measuring the charge-state fractions of ions backscattered from solid or gas targets. A new method is described in which the charge-state fractions of /sup 3/He, /sup 4/He, /sup 12/C, /sup 14/N, and /sup 16/O ions backscattered from gold films are determined simultaneously. The added features in this work are the facts that the method can be efficiently used for low-energy incident ions and that spectra could be measured, compared, and analyzed by minimizing uncertainties inherent in experimental parameters. The energy dependence of the charge-state fractions of /sup 3/He, /sup 4/He, and /sup 12/C ions are measured between 3 MeV and 150 keV. The /sup 12/C charge-state-fraction data nicely fit the Gaussian model but none of the chi/sup 2/ models. The mean ion charge i/sub m/ and the standard deviation s are also measured. Preliminary measurements of the dependence of the charge-state fractions on target thickness are also discussed.

  6. Plasma immersion ion charge state and mass spectrometer

    SciTech Connect

    Ryabchikov, Alexander I.; Ryabchikov, Igor A.; Stepanov, Igor B.; Sinebryukhov, Andrei A.

    2006-03-15

    This work is devoted to the development and investigation of a new spectrometer for the measurement of ion charge state and mass composition of a plasma based on the combination of two methods--plasma immersion ion acceleration and time-of-flight ion separation. Ion acceleration in the spectrometer is carried out in the short-pulse mode by applying a negative bias potential to the plasma-immersed drift tube. The measurement of the ion current at the end of the tube using time-of-flight ion separation must be done after the bias potential pulse termination. The investigations of the ion charge state were carried out using a dc vacuum-arc Ti metal plasma. It is experimentally shown that the application of a negative bias potential with a pulse amplitude of more than 1.5 kV and duration in the range from 50 to 1000 ns allows measuring the spectra with good charge state and mass resolution for various plasma concentrations and drift tube lengths from 0.5 to 0.9 m. The spectrometer is noted for the design simplicity and compactness. It can be used for ion charge state and mass composition investigation in the wide range of concentration of most Periodic Table metal element plasmas.

  7. Formation of High Charge State Heavy Ion Beams with intense Space Charge

    SciTech Connect

    Seidl, P.A.; Vay, J-L.

    2011-03-01

    High charge-state heavy-ion beams are of interest and used for a number of accelerator applications. Some accelerators produce the beams downstream of the ion source by stripping bound electrons from the ions as they pass through a foil or gas. Heavy-ion inertial fusion (HIF) would benefit from low-emittance, high current ion beams with charge state >1. For these accelerators, the desired dimensionless perveance upon extraction from the emitter is {approx}10{sup -3}, and the electrical current of the beam pulse is {approx}1 A. For accelerator applications where high charge state and very high current are desired, space charge effects present unique challenges. For example, in a stripper, the separation of charge states creates significant nonlinear space-charge forces that impact the beam brightness. We will report on the particle-in-cell simulation of the formation of such beams for HIF, using a thin stripper at low energy.

  8. 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.

  9. The effect of reagent charge state on the charge inversion efficiency of singly charged polyatomic ions in the gas phase.

    PubMed

    Hassell, Kerry M; Hilger, Ryan T; McLuckey, Scott A

    2011-11-07

    A variety of combinations of oppositely charged ions have been reacted to examine the role of the charge state from a multiply protonated or multiply deprotonated reagent ion on the efficiency of conversion of a singly charged ion of opposite polarity to a singly charged ion of the same polarity as the reagent. Maximum efficiencies on the order of tens of percent were observed. A threshold for charge inversion was noted in all cases and, with one exception, a clear decrease in efficiency was also noted at high charge states. A model was developed to predict charge inversion efficiency based on charge states, cross-sections of the reactants, and relevant thermodynamic ion affinity values for the reactants and products. The model predicts a threshold for charge inversion, although the prediction does not match the observed threshold quantitatively. This discrepancy is likely due to a simplifying assumption that is not justified on a quantitative basis but which does reproduce the qualitative trend. The model does not predict the major decrease in efficiency at high charge states. However, calculations show that the kinetic energies of the charge inversion products can lead to significant scattering losses at high charge states of the ion-ion collision complex.

  10. Modeling the detector of charge states of relativistic multicharged ions

    NASA Astrophysics Data System (ADS)

    Malyshevsky, V. S.; Fomin, G. V.; Ivanova, I. A.

    2017-01-01

    A way to identify charge distributions of relativistic multicharged ions by recording the angular distribution of the Cherenkov radiation of ions is analyzed; preliminarily, ions with different charges are separated by ion velocities in an external target with a large charge number. As a result, when an ion beam enters the Cherenkov radiator, different charges radiate at different angles to the direction of the ion motion and the radiation intensity is proportional to the fraction of ions with a given charge in the beam.

  11. Charge state defect engineering of silicon during ion implantation

    SciTech Connect

    Brown, R.A.; Ravi, J.; Erokhin, Y.; Rozgonyi, G.A.; White, C.W.

    1997-01-01

    Effects of in situ interventions which alter defect interactions during implantation, and thereby affect the final damage state, have been investigated. Specifically, we examined effects of internal electric fields and charge carrier injection on damage accumulation in Si. First, we implanted H or He ions into diode structures which were either reverse or forward biased during implantation. Second, we implanted B or Si ions into plain Si wafers while illuminating them with UV light. In each case, the overall effect is one of damage reduction. Both the electric field and charge carrier injection effects may be understood as resulting from changes in defect interactions caused in part by changes to the charge state of defects formed during implantation.

  12. 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.

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

    SciTech Connect

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

    2016-02-15

    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.

  14. 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.

  15. 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.

  16. Production of multiply charge-state ions in a multicusp ion source

    NASA Astrophysics Data System (ADS)

    Williams, M. D.; deVries, G. J.; Gough, R. A.; Leung, K. N.; Monroy, M.

    1996-03-01

    High charge state ion beams are commonly used in atomic and nuclear physics experiments. Multiply charged ions are normally produced in an ECR or in an EBIS. Multicusp generators can confine primary electrons very efficiently. Therefore, the electrical and gas efficiencies of these devices are high. Since the magnetic cusp fields are localized near the chamber wall, large volumes of uniform and high density plasmas can be obtained at low pressure, conditions favorable for the formation of multiply charged state ions. Attempts have been made at LBNL to generate multiply charged ion beams by employing a 25-cm diam by 25-cm long multicusp source. Experimental results demonstrated that charge states as high as 7+ can be obtained with argon or xenon plasmas. Multiply charged metallic ions such as tungsten and titanium have also been successfully formed in the multicusp source by evaporation and sputtering processes. In order to extend the charge state to higher values, a novel technique of injecting high energy electrons into the source plasma is proposed. If this is successful, the multicusp source will become very useful for radioactive beam accelerators, ion implantation, and nuclear physics applications.

  17. 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.

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

    SciTech Connect

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

    2016-02-15

    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.

  19. High ion charge states in a high-current, short-pulse, vacuum ARC ion sources

    SciTech Connect

    Anders, A.; Brown, I.; MacGill, R.; Dickinson, M.

    1996-08-01

    Ions of the cathode material are formed at vacuum arc cathode spots and extracted by a grid system. The ion charge states (typically 1-4) depend on the cathode material and only little on the discharge current as long as the current is low. Here the authors report on experiments with short pulses (several {mu}s) and high currents (several kA); this regime of operation is thus approaching a more vacuum spark-like regime. Mean ion charge states of up to 6.2 for tungsten and 3.7 for titanium have been measured, with the corresponding maximum charge states of up to 8+ and 6+, respectively. The results are discussed in terms of Saha calculations and freezing of the charge state distribution.

  20. [Probabilistic calculations of biomolecule charge states that generate mass spectra of multiply charged ions].

    PubMed

    Raznikova, M O; Raznikov, V V

    2015-01-01

    In this work, information relating to charge states of biomolecule ions in solution obtained using the electrospray ionization mass spectrometry of different biopolymers is analyzed. The data analyses have mainly been carried out by solving an inverse problem of calculating the probabilities of retention of protons and other charge carriers by ionogenic groups of biomolecules with known primary structures. The approach is a new one and has no known to us analogues. A program titled "Decomposition" was developed and used to analyze the charge distribution of ions of native and denatured cytochrome c mass spectra. The possibility of splitting of the charge-state distribution of albumin into normal components, which likely corresponds to various conformational states of the biomolecule, has been demonstrated. The applicability criterion for using previously described method of decomposition of multidimensional charge-state distributions with two charge carriers, e.g., a proton and a sodium ion, to characterize the spatial structure of biopolymers in solution has been formulated. In contrast to known mass-spectrometric approaches, this method does not require the use of enzymatic hydrolysis or collision-induced dissociation of the biopolymers.

  1. Charge state dependent energy deposition by ion impact.

    PubMed

    Lake, R E; Pomeroy, J M; Grube, H; Sosolik, C E

    2011-08-05

    We report on a measurement of craters in thin dielectric films formed by Xe(Q+) (26 ≤ Q ≤ 44) projectiles. Tunnel junction devices with ion-irradiated barriers were used to amplify the effect of charge-dependent cratering through the exponential dependence of tunneling conductance on barrier thickness. Electrical conductance of a crater σ(c)(Q) increased by 4 orders of magnitude (7.9 × 10(-4) μS to 6.1 μS) as Q increased, corresponding to crater depths ranging from 2 to 11 Å. By employing a heated spike model, we determine that the energy required to produce the craters spans from 8 to 25 keV over the investigated charge states. Considering energy from preequilibrium nuclear and electronic stopping as well as neutralization, we find that at least (27 ± 2)% of available projectile neutralization energy is deposited into the thin film during impact.

  2. 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].

  3. Effects of Solvent on the Maximum Charge State and Charge State Distribution of Protein Ions Produced by Electrospray Ionization

    PubMed Central

    Iavarone, Anthony T.; Jurchen, John C.; Williams, Evan R.

    2005-01-01

    The effects of solvent composition on both the maximum charge states and charge state distributions of analyte ions formed by electrospray ionization were investigated using a quadrupole mass spectrometer. The charge state distributions of cytochrome c and myoglobin, formed from 47%/50%/3% water/solvent/acetic acid solutions, shift to lower charge (higher m/z) when the 50% solvent fraction is changed from water to methanol, to acetonitrile, to isopropanol. This is also the order of increasing gas-phase basicities of these solvents, although other physical properties of these solvents may also play a role. The effect is relatively small for these solvents, possibly due to their limited concentration inside the electrospray interface. In contrast, the addition of even small amounts of diethylamine (<0.4%) results in dramatic shifts to lower charge, presumably due to preferential proton transfer from the higher charge state ions to diethylamine. These results clearly show that the maximum charge states and charge state distributions of ions formed by electrospray ionization are influenced by solvents that are more volatile than water. Addition of even small amounts of two solvents that are less volatile than water, ethylene glycol and 2-methoxyethanol, also results in preferential deprotonation of higher charge state ions of small peptides, but these solvents actually produce an enhancement in the higher charge state ions for both cytochrome c and myoglobin. For instruments that have capabilities that improve with lower m/z, this effect could be taken advantage of to improve the performance of an analysis. PMID:11073261

  4. Charge States of y Ions in the Collision-Induced Dissociation of Doubly Charged Tryptic Peptide Ions

    NASA Astrophysics Data System (ADS)

    Neta, Pedatsur; Stein, Stephen E.

    2011-05-01

    Bonds that break in collision-induced dissociation (CID) are often weakened by a nearby proton, which can, in principle, be carried away by either of the product fragments. Since peptide backbone dissociation is commonly charge-directed, relative intensities of charge states of product y- and b-ions depend on the final location of that proton. This study examines y-ion charge distributions for dissociation of doubly charged peptide ions, using a large reference library of peptide ion fragmentation generated from ion-trap CID of peptide ions from tryptic digests. Trends in relative intensities of y2+ and y1+ ions are examined as a function of bond cleavage position, peptide length (n), residues on either side of the bond and effects of residues remote from the bond. It is found that yn-2/b2 dissociation is the most sensitive to adjacent amino acids, that y2+/y1+ steadily increase with increasing peptide length, that the N-terminal amino acid can have a major influence in all dissociations, and in some cases other residues remote from the bond cleavage exert significant effects. Good correlation is found between the values of y2+/y1+ for the peptide and the proton affinities of the amino acids present at the dissociating peptide bond. A few deviations from this correlation are rationalized by specific effects of the amino acid residues. These correlations can be used to estimate trends in y2+/y1+ ratios for peptide ions from amino acid proton affinities.

  5. 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.

  6. 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.

  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. Molecular effect on equilibrium charge-state distributions. [of nitrogen ions injected through carbon foil

    NASA Technical Reports Server (NTRS)

    Wickholm, D.; Bickel, W. S.

    1976-01-01

    The paper describes an experiment consisting of the acceleration of N(+) and N2(+) ions to energies between 0.25 and 1.75 MeV and their injection through a thin carbon foil, whereupon they were charge-state analyzed with an electrostatic analyzer. A foil-covered electrically suppressed Faraday cup, connected to a stepping motor, moved in the plane of the dispersed beams. The Faraday cup current, which was proportional to the number of incident ions, was sent to a current digitizer and computer programmed as a multiscaler. The energy-dependent charge-state fractions, the mean charge and the distribution width were calculated. It was shown that for incident atoms, the charge state distribution appeared to be spread over more charge states, while for the incident molecules, there was a greater fraction of charge states near the mean charge.

  9. Molecular effect on equilibrium charge-state distributions. [of nitrogen ions injected through carbon foil

    NASA Technical Reports Server (NTRS)

    Wickholm, D.; Bickel, W. S.

    1976-01-01

    The paper describes an experiment consisting of the acceleration of N(+) and N2(+) ions to energies between 0.25 and 1.75 MeV and their injection through a thin carbon foil, whereupon they were charge-state analyzed with an electrostatic analyzer. A foil-covered electrically suppressed Faraday cup, connected to a stepping motor, moved in the plane of the dispersed beams. The Faraday cup current, which was proportional to the number of incident ions, was sent to a current digitizer and computer programmed as a multiscaler. The energy-dependent charge-state fractions, the mean charge and the distribution width were calculated. It was shown that for incident atoms, the charge state distribution appeared to be spread over more charge states, while for the incident molecules, there was a greater fraction of charge states near the mean charge.

  10. Charge transfer to ground-state ions produces free electrons

    NASA Astrophysics Data System (ADS)

    You, D.; Fukuzawa, H.; Sakakibara, Y.; Takanashi, T.; Ito, Y.; Maliyar, G. G.; Motomura, K.; Nagaya, K.; Nishiyama, T.; Asa, K.; Sato, Y.; Saito, N.; Oura, M.; Schöffler, M.; Kastirke, G.; Hergenhahn, U.; Stumpf, V.; Gokhberg, K.; Kuleff, A. I.; Cederbaum, L. S.; Ueda, K.

    2017-01-01

    Inner-shell ionization of an isolated atom typically leads to Auger decay. In an environment, for example, a liquid or a van der Waals bonded system, this process will be modified, and becomes part of a complex cascade of relaxation steps. Understanding these steps is important, as they determine the production of slow electrons and singly charged radicals, the most abundant products in radiation chemistry. In this communication, we present experimental evidence for a so-far unobserved, but potentially very important step in such relaxation cascades: Multiply charged ionic states after Auger decay may partially be neutralized by electron transfer, simultaneously evoking the creation of a low-energy free electron (electron transfer-mediated decay). This process is effective even after Auger decay into the dicationic ground state. In our experiment, we observe the decay of Ne2+ produced after Ne 1s photoionization in Ne-Kr mixed clusters.

  11. Charge transfer to ground-state ions produces free electrons

    PubMed Central

    You, D.; Fukuzawa, H.; Sakakibara, Y.; Takanashi, T.; Ito, Y.; Maliyar, G. G.; Motomura, K.; Nagaya, K.; Nishiyama, T.; Asa, K.; Sato, Y.; Saito, N.; Oura, M.; Schöffler, M.; Kastirke, G.; Hergenhahn, U.; Stumpf, V.; Gokhberg, K.; Kuleff, A. I.; Cederbaum, L. S.; Ueda, K

    2017-01-01

    Inner-shell ionization of an isolated atom typically leads to Auger decay. In an environment, for example, a liquid or a van der Waals bonded system, this process will be modified, and becomes part of a complex cascade of relaxation steps. Understanding these steps is important, as they determine the production of slow electrons and singly charged radicals, the most abundant products in radiation chemistry. In this communication, we present experimental evidence for a so-far unobserved, but potentially very important step in such relaxation cascades: Multiply charged ionic states after Auger decay may partially be neutralized by electron transfer, simultaneously evoking the creation of a low-energy free electron (electron transfer-mediated decay). This process is effective even after Auger decay into the dicationic ground state. In our experiment, we observe the decay of Ne2+ produced after Ne 1s photoionization in Ne–Kr mixed clusters. PMID:28134238

  12. Probing lithium-ion batteries' state-of-charge using ultrasonic transmission - Concept and laboratory testing

    NASA Astrophysics Data System (ADS)

    Gold, Lukas; Bach, Tobias; Virsik, Wolfgang; Schmitt, Angelika; Müller, Jana; Staab, Torsten E. M.; Sextl, Gerhard

    2017-03-01

    For electrically powered applications such as consumer electronics and especially for electric vehicles a precise state-of-charge estimation for their lithium-ion batteries is desired to reduce aging, e.g. avoiding detrimental states-of-charge. Today, this estimation is performed by battery management systems that solely rely on charge bookkeeping and cell voltage measurements. In the present work we introduce a new, physical probe for the state-of-charge based on ultrasonic transmission. Within the simple experimental setup raised cosine pulses are applied to lithium-ion battery pouch cells, whose signals are sensitive to changes in porosity of the graphite anode during charging/dis-charging and, therefore, to the state-of-charge. The underlying physical principle can be related to Biot's theory about propagation of waves in fluid saturated porous media and by including scattering by boundary layers inside the cell.

  13. 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.

  14. Charge state distribution of anomalous oxygen ions in low Earth orbit during solar quiescence.

    PubMed

    Marenny, A M; Guertzen, G P; Nymmik, R A

    1990-01-01

    A new method of evaluating the charge state distribution of cosmic ray heavy ions, using a measured ratio of particle fluxes observed in two different satellite orbits passing through the Earth's magnetosphere, is described. The measurements of heavy ions were performed simultaneously on the Cosmos 1882 (orbital inclination 82 degrees) and Cosmos 1887 (inclination 62.3 degrees) satellites during September-October 1987. Solid state nuclear track detector stacks were used for the registration of C, N, O and heavier ions. After comparing the data of the two experiments with theoretical calculations, the charge state of galactic and anomalous heavy ions was derived.

  15. Model for charge state distributions of heavy Coulomb explosion fragment ions

    SciTech Connect

    Cooney, P.J.; Faibis, A.; Kanter, E.P.; Koenig, W.; Maor, D.; Zabransky, B.J.

    1985-01-01

    We have conclusively demonstrated the systematic shift of the distributions of final charge states, for Coulomb explosion fragments compared to isotachic monatomic ion beams. This shift includes both an enhanced yield of lower charge states (below the equilibrium mean) concomitant with a decrease in the yield of charge states above the mean and thus essentially preserves the shapes of the distributions. From the trends of the data, it was shown that this shift is attributable to an enhanced electron capture probability for ions emerging from the target foil as spatially correlated diatomic clusters. A simple model was presented relating the charge state distributions measured for molecular-ion impact to the equilibrium distribution measured for the case of impact by a monatomic ion beam. This model describes the apparent nonequilibration of the molecular-ion charge state distributions as a simple consequence of electron capture cross sections dependent upon the internuclear separations of the exiting cluster fragments. Because this separation is large compared to the orbital radius of captured electrons, the enhancement of the electron capture cross sections can be treated as a weak perturbation of the potential at the position of the electron. Such an approximation allows the estimation of this enhancement. This model, though admittedly overly simplified, resolves the long-standing problem of understanding the distributions of final charge states when heavy diatomic molecular ions exit from solids.

  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. Charge-state shifting of individual multiply-charged ions of bovine albumin dimer and molecular weight determination using an individual-ion approach

    SciTech Connect

    Cheng, X.; Bakhtiar, R.; Van Orden, S.; Smith, R.D. )

    1994-07-01

    Ion-molecule reactions of individual multiply-protonated ions of bovine albumin dimer, formed from electrospray ionization, have been studied using a Fourier transform ion cyclotron resonance mass spectrometer. Upon reaction of ammonia with a group of individual ions, charge-state shifting was observed due to proton transfer. Repeated additions of ammonia during remeasurements of the same ion population were observed to induce multiple-step charge-state shifts. Charge-state-dependent reactivity, as well as nonstatistical behavior in reactivity, was observed due to the small ion population. The molecular weights of individual ions whose charge state shifted during reaction were determined with an accuracy of 67 ppm, the first example of using an individual-ion approach to the determination of molecular weight for a large biopolymer. The molecular weight distribution of a group of ions can be determined with a precision related to the number of ions examined and the weight heterogeneity of the sample. We obtained the molecular weight for eight individual ions from which a molecular weight of 133 320 [+-] 210 Da was calculated for bovine albumin dimer. 17 refs., 3 figs., 1 tab.

  18. Dependence of hydrogen released on the charge state of incident ions

    NASA Astrophysics Data System (ADS)

    Gupta, D. P.; Chauhan, R. S.; Kumar, S.; Diwan, P. K.; Khan, S. A.; Tripathi, A.; Singh, F.; Ghosh, S.; Avasthi, D. K.; Mittal, V. K.

    2006-06-01

    The behavior of polymers under heavy ion bombardment is of great interest. In the present study, hydrogen released from polypropylene (PP) and polyethylene terephthalate (PET) was investigated as a function of charge state (11(+) , 14(+) , and 25(+) ) for 130 MeV 107 Ag ions. It was found that hydrogen released from the polymers varies as alpha q(n) , where n was found to be 2.98 and 1.94 for PP and PET, respectively, when compared with the value of similar to 3.0 reported in the literature for different polymers and ion combinations. Radii of the damaged zones or ion track formed were deduced from the slope of the hydrogen released versus ion fluence curves. This radius was also found to depend upon the charge state of the incident ion. It varies as beta q(m) , where m is 1.25 and 0.741 for PP and PET, respectively.

  19. Effects of Charge State, Charge Distribution, and Structure on the Ion Mobility of Protein Ions in Helium Gas: Results from Trajectory Method Calculations.

    PubMed

    Laszlo, Kenneth J; Bush, Matthew F

    2017-09-27

    Collision cross section (Ω) values of gas-phase ions of proteins and protein complexes are used to probe the structures of the corresponding species in solution. Ions of many proteins exhibit increasing Ω-values with increasing charge state but most Ω-values calculated for protein ions have used simple collision models that do not explicitly account for charge. Here we use a combination of ion mobility mass spectrometry experiments with helium gas and trajectory method calculations to characterize the extents to which increases in experimental Ω-values with increasing charge state may be attributed to increased momentum transfer concomitant with enhanced long-range interactions between the protein ion and helium atoms. Ubiquitin and C-to-N terminally linked diubiquitin ions generated from different solution conditions exhibit more than a 2-fold increase in Ω with increasing charge state. For native and energy-relaxed models of the proteins and most methods for distributing charge, Ω-values calculated using the trajectory method increase by less than 1% over the range of charge states observed from typical solution conditions used for native mass spectrometry. However, the calculated Ω-values increase by 10% to 15% over the full range of charge states observed from all solution conditions. Therefore, contributions from enhanced ion-induced dipole interactions with increasing charge state are significant but without additional structural changes can account for only a fraction of the increase in Ω observed experimentally. On the basis of these results, we suggest guidelines for calculating Ω-values in the context of applications in biophysics and structural biology.

  20. 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.

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

    NASA Astrophysics Data System (ADS)

    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.

  2. 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.

  3. 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.

  4. Time-dependence ion charge state distributions of vacuum arcs: An interpretation involving atoms and charge exchange collisions

    SciTech Connect

    Anders, Andre

    2004-08-27

    Experimentally observed charge state distributions are known to be higher at the beginning of each arc discharge. Up to know, this has been attributed to cathode surface effects in terms of changes of temperature, chemical composition and spot mode. Here it is shown that the initial decay of charge states of cathodic arc plasmas may at least in part due to charge exchange collisions of ions with neutrals that gradually fill the discharge volume. Sources of neutrals may include evaporated atoms from macroparticles and still-hot craters of previously active arc spots. More importantly, atoms are also produced by energetic condensation of the cathodic arc plasma. Self-sputtering is significant when ions impact with near-normal angle of incidence, and ions have low sticking probability when impacting at oblique angle of incidence. Estimates show that the characteristic time for filling the near-cathode discharge volume agrees well with the charge state decay time, and the likelihood of charge exchange is reasonably large to be taken into account.

  5. Future prospects for ECR ion sources with improved charge state distributions

    SciTech Connect

    Alton, G.D.

    1995-12-31

    Despite the steady advance in the technology of the ECR ion source, present art forms have not yet reached their 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 used to heat the plasma electrons. This article identifies fundamentally important methods which may enhance the performances of ECR ion sources through the use of: (1) a tailored magnetic field configuration (spatial domain) in combination with single-frequency microwave radiation to create a large uniformly distributed ECR ``volume`` or (2) the use of broadband frequency domain techniques (variable-frequency, broad-band frequency, or multiple-discrete-frequency microwave radiation), derived from standard TWT technology, to transform the resonant plasma ``surfaces`` of traditional ECR ion sources into resonant plasma ``volume``. The creation of a large ECR plasma ``volume`` permits coupling of more power into the plasma, resulting in the heating of a much larger electron population to higher energies, thereby producing higher charge state ions and much higher intensities within a particular charge state than possible in present forms of` the source. The ECR ion source concepts described in this article offer exciting opportunities to significantly advance the-state-of-the-art of ECR technology and as a consequence, open new opportunities in fundamental and applied research and for a variety of industrial applications.

  6. 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.

  7. State-selective charge transfer cross sections for light ion impact of atomic hydrogen

    SciTech Connect

    Schultz, D. R.; Stancil, Phillip C.; Havener, C. C.

    2015-01-01

    Owing to the utility of diagnosing plasma properties such as impurity concentration and spatial distribution, and plasma temperature and rotation, by detection of photon emission following capture of electrons from atomic hydrogen to excited states of multiply charged ions, new calculations of state-selective charge transfer involving light ions have been carried out using the atomic orbital close-coupling and the classical trajectory Monte Carlo methods. By comparing these with results of other approaches applicable in a lower impact energy regime, and by benchmarking them using key experimental data, knowledge of the cross sections can be made available across the range parameters needed by fusion plasma diagnostics.

  8. 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.

  9. 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.

  10. 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

  11. Pre- and postextraction analyses of different charge state ion components produced in a laser ion source

    NASA Astrophysics Data System (ADS)

    Belloni, F.; Doria, D.; Lorusso, A.; Nassisi, V.; Krasa, J.

    2006-03-01

    Knowledge of the relative abundance and the energy distributions of various ion species produced in laser ablation plasma is essential both in the fundamental physics ground, to understand the thermalization and expansion dynamics of the plasma plume, and in the applied physics ground, to obtain an efficient and versatile ion source. We present measurements and analyses related to such aspects, both for plasma in free expansion and for the extracted ion bunch. In particular, we characterized the former by means of ion current measurements, employing appropriate Faraday cups and electrostatic spectrometers. With regard to the latter, we performed time-of-flight spectrometry and depth profiling of implanted substrates. The extracted bunch signal showed modulation on time of flight due to the presence of multiply charged ions; depth profiling by x-ray photoelectron spectroscopy also showed a maximum penetration range and a profile modulation compatible with a multienergetic beam. In these experiments we used ultraviolet excimer lasers, at irradiance values in the range of 0.1-10GW/cm2, to generate plasma from Cu and Al targets. The ion beams were extracted at voltages of tens of kV, dc.

  12. 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.

  13. Resonant charge exchange involving electronically excited states of nitrogen atoms and ions

    SciTech Connect

    Kosarim, A. V.; Smirnov, B. M.; Laricchiuta, A.

    2006-12-15

    Within the framework of the asymptotic theory the matrices for the exchange interaction potentials of the nitrogen ion, with electron shell p{sup 2}, and nitrogen atom, with electron shell p{sup 3}, are constructed. The hierarchy of interactions in the nitrogen molecular ion at large internuclear distances is constructed for different electronic states. On the basis of these interaction potentials, the cross sections of resonant charge exchange in slow collisions are evaluated for different values of electron momentum projections and then averaged over these momentum projections. The mobilities of nitrogen ions in atomic nitrogen are also derived.

  14. An Enhanced Vacuum Arc Ion Source for High Current, High Charge State Uranium Beam Production

    NASA Astrophysics Data System (ADS)

    Johnson, B. M.; Hershcovitch, A.; Brown, I. G.; Leemans, W.; Liu, F.

    1996-05-01

    We plan to carry out an experimental program at LBNL to develop a novel kind of vacuum arc ion source in which the metal ions are further stripped by interaction with an energetic, dense electron beam. Preliminary results obtained by Batalin et al.(V. A. Batalin, Y. N. Volkov, T. V. Kulevoy, and S. V. Petrenko, ITEP, Moscow, Reprints 18-93 (1993), 33-94 (1994); Proc. EPAC 1994, p. 1453.) using this approach have been most promising; the vacuum arc ion source(I.G. Brown, ``Vacuum Arc Ion Sources'', Rev. Sci. Instrum. 65, 3061 (1994).) uranium ion beam output of mostly U^3+ ions was increased significantly, although the yield of high charge state ions was only a small fraction of the original source current. In our experiments the electron beam will propagate antiparallel to the ion beam so as to provide a radially inward Lorentz force to confine and focus the stripped uranium beam, thus maximizing the electron-ion interactions and increasing the ion beam current density. We expect improved performance over the encouraging earlier^1 results. The motivation for this work(Ady Hershcovitch and Brant Johnson, RHIC/DET Note 17 and AGS/ ADD/Tech. Note No. 416) is the desire to eventually inject fully stripped uranium into the Relativistic Heavy Ion Collider (RHIC).

  15. Exit charge state dependence of convoy electron production in heavy-ion solid collisions

    SciTech Connect

    Huelskoetter, H.P.; Burgdoerfer, J.; Sellin, I.A.

    1986-01-01

    The dependence of the yield of convoy electrons emitted near the forward direction in collisions involving fast ions and thin solid targets on the emergent projectile charge state is presented and described in terms of primary electron loss events in the solid. The data include a large array of projectiles, projectile energies and charge states, as well as targets ranging in thickness from the non-equilibrium well into the equilibrium thickness region. The description presented is consistent with other experimental and theoretical results indicating that the convoy electron production is closely linked to the ELC process observed in binary ion-atom collisions, with the dominant contribution to the convoy yield stemming from excited states of the projectiles. 22 refs., 3 figs.

  16. State of Charge estimation of lithium ion battery based on extended Kalman filtering algorithm

    NASA Astrophysics Data System (ADS)

    Yang, Fan; Feng, Yiming; Pan, Binbiao; Wan, Renzhuo; Wang, Jun

    2017-08-01

    Accurate estimation of state-of-charge (SOC) for lithium ion battery is crucial for real-time diagnosis and prognosis in green energy vehicles. In this paper, a state space model of the battery based on Thevenin model is adopted. The strategy of estimating state of charge (SOC) based on extended Kalman fil-ter is presented, as well as to combine with ampere-hour counting (AH) and open circuit voltage (OCV) methods. The comparison between simulation and experiments indicates that the model’s performance matches well with that of lithium ion battery. The algorithm of extended Kalman filter keeps a good accura-cy precision and less dependent on its initial value in full range of SOC, which is proved to be suitable for online SOC estimation.

  17. 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.

  18. 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.

  19. High intensity high charge state ion beam production with an evaporative cooling magnet ECRIS

    SciTech Connect

    Lu, W. Qian, C.; Sun, L. T.; Zhang, X. Z.; Feng, Y. C.; Ma, B. H.; Zhao, H. W.; Zhan, W. L.; Fang, X.; Guo, J. W.; Yang, Y.; Xiong, B.; Ruan, L.; Xie, D.

    2016-02-15

    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{sup 7+}, 620 eμA of Ar{sup 11+}, 430 eμA of Ar{sup 12+}, 430 eμA of Xe{sup 20+}, and so on. The comparison will be discussed in the paper.

  20. 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.

  1. 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.

  2. Charge-state related effects in sputtering of LiF by swift heavy ions

    NASA Astrophysics Data System (ADS)

    Assmann, W.; Ban-d'Etat, B.; Bender, M.; Boduch, P.; Grande, P. L.; Lebius, H.; Lelièvre, D.; Marmitt, G. G.; Rothard, H.; Seidl, T.; Severin, D.; Voss, K.-O.; Toulemonde, M.; Trautmann, C.

    2017-02-01

    Sputtering experiments with swift heavy ions in the electronic energy loss regime were performed by using the catcher technique in combination with elastic recoil detection analysis. The angular distribution of particles sputtered from the surface of LiF single crystals is composed of a jet-like peak superimposed on a broad isotropic distribution. By using incident ions of fixed energy but different charges states, the influence of the electronic energy loss on both components is probed. We find indications that isotropic sputtering originates from near-surface layers, whereas the jet component may be affected by contributions from depth up to about 150 nm.

  3. Charge state of sputtered impurity ions near a limiter or divertor in a tokamak

    SciTech Connect

    Boley, C.D.; Brooks, J.N.; Kim, Y.K.

    1983-03-01

    Many impurity atoms sputtered from a limiter or divertor plate are ionized in the scrapeoff zone and return to the sputtering surface bacause of friction with incoming plasma ions. The final charge state attained by such impurities has been calculated for a variety of plasma edge conditions. The surface materials considered are tungsten, beryllium, beryllium oxide, and carbon. Estimates of the successive ionization cross sections for tungsten are developed. In all cases examined, returning impurity ions are found to be multiply ionized. This implies a significant energy gain in the sheath region, with important implications for self-sputtering of redeposited surface material.

  4. A compact electron beam ion source with integrated Wien filter providing mass and charge state separated beams of highly charged ions.

    PubMed

    Schmidt, M; Peng, H; Zschornack, G; Sykora, S

    2009-06-01

    A Wien filter was designed for and tested with a room temperature electron beam ion source (EBIS). Xenon charge state spectra up to the charge state Xe46+ were resolved as well as the isotopes of krypton using apertures of different sizes. The complete setup consisting of an EBIS and a Wien filter has a length of less than 1 m substituting a complete classical beamline setup. The Wien filter is equipped with removable permanent magnets. Hence total beam current measurements are possible via simple removal of the permanent magnets. In dependence on the needs of resolution a weak (0.2 T) or a strong (0.5 T) magnets setup can be used. In this paper the principle of operation and the design of the Wien filter meeting the requirements of an EBIS are briefly discussed. The first ion beam extraction and separation experiments with a Dresden EBIS are presented.

  5. High intensity production of high and medium charge state uraniumand other heavy ion beams with VENUS

    SciTech Connect

    Leitner, Daniela; Galloway, Michelle L.; Loew, Timothy J.; Lyneis, Claude M.; Rodriguez, Ingrid Castro; Todd, Damon S.

    2007-11-15

    The next generation, superconducting ECR ion source VENUS(Versatile ECR ion source for NUclear Science) started operation with 28GHzmicrowave heating in 2004. Since then it has produced world recordion beam intensities. For example, 2850 e mu A of O6+, 200 e mu A of U33+or U34+, and in respect to high charge state ions, 1 e mu A of Ar18+, 270e mu A of Ar16+, 28 e mu A of Xe35+ and 4.9 e mu A of U47+ have beenproduced. A brief overview of the latest developments leading to theserecord intensities is given and the production of high intensity uraniumbeams is discussed in more detail.

  6. 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

  7. 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.

  8. Average charge states of heavy and superheavy ions passing through a rarified gas: Theory and experiment

    NASA Astrophysics Data System (ADS)

    Khuyagbaatar, J.; Shevelko, V. P.; Borschevsky, A.; Düllmann, Ch. E.; Tolstikhina, I. Yu.; Yakushev, A.

    2013-10-01

    The average charge states q¯ of heavy and superheavy ions (atomic numbers Z=80-114) passing through He gas are studied experimentally and theoretically. Experimental data were measured at the gas-filled recoil separator, i.e., the TransActinide Separator and Chemistry Apparatus (TASCA) at GSI Darmstadt, for ion energies of a few hundred keV/u at gas pressures of 0.2 to 2.0 mbar. An attempt is made to describe experimental q¯ values by means of atomic calculations of the binding energies and electron-loss and electron-capture cross sections. The influence of the gas-density effect is included in the calculations. The calculated q¯ reproduce the experimental values for elements with Z=80-114 within 20%. A comparison with different semiempirical models is presented as well, including a local fit of high accuracy, which is often used in superheavy-element experiments to estimate the average charge states of heavy ions, e.g., at the gas-filled recoil separator TASCA. The q¯ values for elements with Z=115, 117, 119, and 120 at He-gas pressure of 0.8 mbar are predicted.

  9. Direct evidence for projectile charge-state dependent crater formation due to fast ions.

    PubMed

    Papaléo, 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 (q(ini)+) ions of selected incident charge states q_(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_(ini). Variation of q_(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.

  10. 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.

  11. Determination of Peptide and Protein Ion Charge States by Fourier Transformation of Isotope-Resolved Mass Spectra

    SciTech Connect

    Tabb, Dave L; Shah, Manesh B; Strader, Michael B; Connelly, Heather M; Hettich, Robert {Bob} L; Hurst, Gregory {Greg} B

    2006-01-01

    We report an automated method for determining charge states from high-resolution mass spectra. Fourier transforms of isotope packets from high-resolution mass spectra are compared to Fourier transforms of modeled isotopic peak packets for a range of charge states. The charge state for the experimental ion packet is determined by the model isotope packet that yields the best match in the comparison of the Fourier transforms. This strategy is demonstrated for determining peptide ion charge states from 'zoom scan' data from a linear quadrupole ion trap mass spectrometer, enabling the subsequent automated identification of singly-through quadruply-charged peptide ions, while reducing the numbers of conflicting identifications from ambiguous charge state assignments. We also apply this technique to determine the charges of intact protein ions from LC-FTICR data, demonstrating that it is more sensitive under these experimental conditions than two existing algorithms. The strategy outlined in this paper should be generally applicable to mass spectra obtained from any instrument capable of isotopic resolution.

  12. High performance charge-state resolving ion energy analyzer optimized for intense laser studies on low-density cluster targets.

    PubMed

    Komar, D; Meiwes-Broer, K-H; Tiggesbäumker, J

    2016-10-01

    We report on a versatile ion analyzer which is capable to resolve ion charge states and energies with a resolution of E/ΔE = 100 at 75 keV/nucleon. Charge states are identified by their characteristic deflection in a magnetic field, whereas the ion energies are independently determined by a time-of-flight measurement. To monitor the signals a delay-line detector is used which records ion impact positions and times in each laser shot. Compared to conventional Thomson parabola spectrometers our instrument provides a low background measurement, hence a superior dynamic range. Further features are an improved energy resolution and a significantly increased transmission. We demonstrate the performance by showing charge-state resolved ion energy spectra from the Coulomb explosion of a low-density target, i.e., silver clusters exposed to intense femtosecond laser pulses.

  13. State of charge estimation of lithium-ion batteries using fractional order sliding mode observer.

    PubMed

    Zhong, Qishui; Zhong, Fuli; Cheng, Jun; Li, Hui; Zhong, Shouming

    2017-01-01

    This paper presents a state of charge (SOC) estimation method based on fractional order sliding mode observer (SMO) for lithium-ion batteries. A fractional order RC equivalent circuit model (FORCECM) is firstly constructed to describe the charging and discharging dynamic characteristics of the battery. Then, based on the differential equations of the FORCECM, fractional order SMOs for SOC, polarization voltage and terminal voltage estimation are designed. After that, convergence of the proposed observers is analyzed by Lyapunov's stability theory method. The framework of the designed observer system is simple and easy to implement. The SMOs can overcome the uncertainties of parameters, modeling and measurement errors, and present good robustness. Simulation results show that the presented estimation method is effective, and the designed observers have good performance.

  14. Charge Exchange with Highly Charged Ions

    NASA Astrophysics Data System (ADS)

    Glick, Jeremy; Ferri, Kevin; Schmitt, Jaclyn; Hanson, Joshua; Marler, Joan

    2016-05-01

    A detailed study of the physics of highly charged ions (HCIs) is critical for a deep understanding of observed phenomena resulting from interactions of HCIs with neutral atoms in astrophysical and fusion environments. Specifically the charge transfer rates and spectroscopy of the subsequent decay fluorescence are of great interest to these communities. Results from a laboratory based investigation of these rates will be presented. The experiment takes advantage of an energy and charge state selected beam of HCIs from the recently on-line Clemson University EBIT (CUEBIT). Progress towards an experimental apparatus for retrapping HCIs towards precision spectroscopy of HCIs will also be presented.

  15. 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.

  16. 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.

  17. 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.

  18. Multi-state charge transfer dynamics and trapping of hyperthermal and low energy alkali ions

    NASA Astrophysics Data System (ADS)

    Dahl, Eric Brian

    Experimental and theoretical studies were performed of the scattering of hyperthermal and keV energy Lisp+ and Nasp+ ions from Cu(001) surfaces. Chapter one presents measurements of relative total Li(2p) and Na(3p) yields, for 400 eV Lisp+ and 1320 eV Nasp+ scattering from clean and alkali-covered Cu(001). These excited-state yields were measured because they provide a sensitive test of multi-state models of resonant charge transfer, that is, models that are capable of treating more than two atomic states. Chapter two presents a detailed conceptual analysis of two multi-state models: a rate-equation model and the Marston model. The rate-equation model fails to reproduce the measured Li(2p) and Na(3p) yields, whereas the Marston model reproduces the primary trends in the yields. The different behaviors of these models are explained by physical reasoning. The rate-equation model is a fundamentally flawed description of resonant charge transfer, because it includes neither hybridization nor non-adiabatic excitations. Both aspects of resonant charge transfer are required to explain the Li(2p) and Na(3p) yields. These aspects are included in the Marston model, which describes the atom-metal system quantum-mechanically. The quantum mechanics of the atom-metal system can be understood from a physical viewpoint by the use of a few basic principles-principles which are broadly applicable to resonant charge transfer. A key principle is the tendency of the atom-metal system to electronically equilibrate throughout the scattering trajectory of an atom. Additional principles follow from an examination of the many-electron basis states of the atom-metal system. Chapter three presents measurements of the probability that 5 to 600 eV Nasp+ ions incident on Cu(001) become trapped on top of the surface. At a near-normal incident geometry the on-top trapping probability decreased monotonically as the incident energy was decreased. At 45sp° incidence along the < 100> azimuth, a

  19. State of charge classification for lithium-ion batteries using impedance based features

    NASA Astrophysics Data System (ADS)

    Patrik Felder, Marian; Götze, Jürgen

    2017-09-01

    Currently, the electrification of the drive train of passenger cars takes place, and the task of obtaining precise knowledge about the condition of the on board batteries gains importance. Due to a flat open circuit voltage (OCV) to state of charge (SoC) characteristic of lithium ion batteries, methods employed in applications with other cell chemistries cannot be adapted. Exploiting the higher significance of the impedance for state estimation for that chemistry, new impedance based features are proposed by this work. To evaluate the suitability of these features, simulations have been conducted using a simplified on-board power supply net as excitation source. The simulation outcome has been investigated regarding the cross correlation factor rxy and in a polynomial regression scenario. The results of the simulations show a best case error below 1 % SoC, which is 3 percentage points lower than using terminal voltage and impedance. When increasing the measurement uncertainty, the difference remains around 2 percent points.

  20. Electron Transfer Dissociation: Effects of Cation Charge State on Product Partitioning in Ion/Ion Electron Transfer to Multiply Protonated Polypeptides

    PubMed Central

    Liu, Jian; McLuckey, Scott A.

    2012-01-01

    The effect of cation charge state on product partitioning in the gas-phase ion/ion electron transfer reactions of multiply protonated tryptic peptides, model peptides, and relatively large peptides with singly charged radical anions has been examined. In particular, partitioning into various competing channels, such as proton transfer (PT) versus electron transfer (ET), electron transfer with subsequent dissociation (ETD) versus electron transfer with no dissociation (ET,noD), and fragmentation of backbone bonds versus fragmentation of side chains, was measured quantitatively as a function of peptide charge state to allow insights to be drawn about the fundamental aspects of ion/ion reactions that lead to ETD. The ET channel increases relative to the PT channel, ETD increases relative to ET,noD, and fragmentation at backbone bonds increases relative to side-chain cleavages as cation charge state increases. The increase in ET versus PT with charge state is consistent with a Landau-Zener based curve-crossing model. An optimum charge state for ET is predicted by the model for the ground state-to-ground state reaction. However, when the population of excited product ion states is considered, it is possible that a decrease in ET efficiency as charge state increases will not be observed due to the possibility of the population of excited electronic states of the products. Several factors can contribute to the increase in ETD versus ET,noD and backbone cleavage versus side-chain losses. These factors include an increase in reaction exothermicity and charge state dependent differences in precursor and product ion structures, stabilities, and sites of protonation. PMID:23264749

  1. Adding high time resolution to charge-state-specific ion energy measurements for pulsed copper vacuum arc plasmas

    NASA Astrophysics Data System (ADS)

    Tanaka, Koichi; Han, Liang; Zhou, Xue; Anders, André

    2015-08-01

    Charge-state-resolved ion energy-time distributions of pulsed Cu arc plasma were obtained by using direct (time-dependent) acquisition of the ion detection signal from a commercial ion mass-per-charge and energy-per-charge analyzer. We find a shift of energies of Cu2+, Cu3+ and Cu4+ ions to lower values during the first few hundred microseconds after arc ignition, which is evidence for particle collisions in the plasma. The generation of Cu+ ions in the later part of the pulse, measured by the increase of Cu+ signal intensity and an associated slight reduction of the mean charge state, points to charge exchange reactions between ions and neutrals. At the very beginning of the pulse, when the plasma expands into vacuum and the plasma potential strongly fluctuates, ions with much higher energy (over 200 eV) are observed. Early in the pulse, the ion energies observed are approximately proportional to the ion charge state, and we conclude that the acceleration mechanism is primarily based on acceleration in an electric field. This field is directed away from the cathode, indicative of a potential hump. Measurements by a floating probe suggest that potential structures travel, and ions moving in the traveling field can gain high energies up to a few hundred electron-volts. Later in the pulse, the approximate proportionality is lost, which is related to increased smearing out of different energies due to collisions with neutrals, and/or to a change of the acceleration character from electrostatic to ‘gas-dynamic’, i.e. dominated by pressure gradient.

  2. 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

  3. Origin and Ion Charge State Evolution of Solar Wind Transients during 4 - 7 August 2011

    NASA Astrophysics Data System (ADS)

    Rodkin, D.; Goryaev, F.; Pagano, P.; Gibb, G.; Slemzin, V.; Shugay, Y.; Veselovsky, I.; Mackay, D. H.

    2017-07-01

    We present a study of the complex event consisting of several solar wind transients detected by the Advanced Composition Explorer (ACE) on 4 - 7 August 2011, which caused a geomagnetic storm with Dst=-110 nT. The supposed coronal sources, three flares and coronal mass ejections (CMEs), occurred on 2 - 4 August 2011 in active region (AR) 11261. To investigate the solar origin and formation of these transients, we study the kinematic and thermodynamic properties of the expanding coronal structures using the Solar Dynamics Observatory/Atmospheric Imaging Assembly (SDO/AIA) EUV images and differential emission measure (DEM) diagnostics. The Helioseismic and Magnetic Imager (HMI) magnetic field maps were used as the input data for the 3D magnetohydrodynamic (MHD) model to describe the flux rope ejection (Pagano, Mackay, and Poedts, 2013b). We characterize the early phase of the flux rope ejection in the corona, where the usual three-component CME structure formed. The flux rope was ejected with a speed of about 200 km s^{-1} to the height of 0.25 R_{⊙}. The kinematics of the modeled CME front agrees well with the Solar Terrestrial Relations Observatory (STEREO) EUV measurements. Using the results of the plasma diagnostics and MHD modeling, we calculate the ion charge ratios of carbon and oxygen as well as the mean charge state of iron ions of the 2 August 2011 CME, taking into account the processes of heating, cooling, expansion, ionization, and recombination of the moving plasma in the corona up to the frozen-in region. We estimate a probable heating rate of the CME plasma in the low corona by matching the calculated ion composition parameters of the CME with those measured in situ for the solar wind transients. We also consider the similarities and discrepancies between the results of the MHD simulation and the observations.

  4. State selective Rydberg charge transfer and ionization in low energy ion-atom collisions

    NASA Astrophysics Data System (ADS)

    Perumal, A. N.; Tripathi, D. N.

    1998-10-01

    The Classical Trajectory Monte Carlo (CTMC) simulation method with a core modified interaction potential has been used to study the single charge transfer in Na +and Ar + ions colliding with a variety of state selected Na Rydberg atom targets ( n=24, 28, 33, 40 and l=2) in the reduced velocity region v=0.2-2.0. The experimentally observed structures in the total capture cross section versus reduced velocity curves are reproduced by CTMC method. The n-distribution of final capture state has got two peaks viz. first one at nf= ni and the second one at a higher nf depending on the initial angular momentum in the velocity regime 0.4-0.6. These structures have been explained in terms of quasimolecular-ion formation and a classical model proposed by Roy et al. (B.N. Roy, D.N. Tripathi, D.K. Rai, Phys. Rev. A 5 (1972) 1252). The CTMC ionization cross section results are benchmarked with the recent experimental measurement of Makarov et al. (O.P. Makarov, D.M. Homan, O.P. Sorokina, K.B. MacAdam, in: F. Aumayr, G. Betz, H.P. Winter (Eds.), Proceedings of the 20th International Conference on the Physics of Electronics and Atomic Collisions, Vienna, 1997, p. FR052) for Na +-Na(24 d).

  5. Charge-state dependent compaction and dissociation of protein complexes: insights from ion mobility and molecular dynamics.

    PubMed

    Hall, Zoe; Politis, Argyris; Bush, Matthew F; Smith, Lorna J; Robinson, Carol V

    2012-02-22

    Collapse to compact states in the gas phase, with smaller collision cross sections than calculated for their native-like structure, has been reported previously for some protein complexes although not rationalized. Here we combine experimental and theoretical studies to investigate the gas-phase structures of four multimeric protein complexes during collisional activation. Importantly, using ion mobility-mass spectrometry (IM-MS), we find that all four macromolecular complexes retain their native-like topologies at low energy. Upon increasing the collision energy, two of the four complexes adopt a more compact state. This collapse was most noticeable for pentameric serum amyloid P (SAP) which contains a large central cavity. The extent of collapse was found to be highly correlated with charge state, with the surprising observation that the lowest charge states were those which experience the greatest degree of compaction. We compared these experimental results with in vacuo molecular dynamics (MD) simulations of SAP, during which the temperature was increased. Simulations showed that low charge states of SAP exhibited compact states, corresponding to collapse of the ring, while intermediate and high charge states unfolded to more extended structures, maintaining their ring-like topology, as observed experimentally. To simulate the collision-induced dissociation (CID) of different charge states of SAP, we used MS to measure the charge state of the ejected monomer and assigned this charge to one subunit, distributing the residual charges evenly among the remaining four subunits. Under these conditions, MD simulations captured the unfolding and ejection of a single subunit for intermediate charge states of SAP. The highest charge states recapitulated the ejection of compact monomers and dimers, which we observed in CID experiments of high charge states of SAP, accessed by supercharging. This strong correlation between theory and experiment has implications for further

  6. State-of-charge estimation in lithium-ion batteries: A particle filter approach

    NASA Astrophysics Data System (ADS)

    Tulsyan, Aditya; Tsai, Yiting; Gopaluni, R. Bhushan; Braatz, Richard D.

    2016-11-01

    The dynamics of lithium-ion batteries are complex and are often approximated by models consisting of partial differential equations (PDEs) relating the internal ionic concentrations and potentials. The Pseudo two-dimensional model (P2D) is one model that performs sufficiently accurately under various operating conditions and battery chemistries. Despite its widespread use for prediction, this model is too complex for standard estimation and control applications. This article presents an original algorithm for state-of-charge estimation using the P2D model. Partial differential equations are discretized using implicit stable algorithms and reformulated into a nonlinear state-space model. This discrete, high-dimensional model (consisting of tens to hundreds of states) contains implicit, nonlinear algebraic equations. The uncertainty in the model is characterized by additive Gaussian noise. By exploiting the special structure of the pseudo two-dimensional model, a novel particle filter algorithm that sweeps in time and spatial coordinates independently is developed. This algorithm circumvents the degeneracy problems associated with high-dimensional state estimation and avoids the repetitive solution of implicit equations by defining a 'tether' particle. The approach is illustrated through extensive simulations.

  7. Charge exchange molecular ion source

    DOEpatents

    Vella, Michael C.

    2003-06-03

    Ions, particularly molecular ions with multiple dopant nucleons per ion, are produced by charge exchange. An ion source contains a minimum of two regions separated by a physical barrier and utilizes charge exchange to enhance production of a desired ion species. The essential elements are a plasma chamber for production of ions of a first species, a physical separator, and a charge transfer chamber where ions of the first species from the plasma chamber undergo charge exchange or transfer with the reactant atom or molecules to produce ions of a second species. Molecular ions may be produced which are useful for ion implantation.

  8. Origin and Ion Charge State Evolution of Solar Wind Transients 4 - 7 August 2011

    NASA Astrophysics Data System (ADS)

    Rodkin, Denis; Goryaev, Farid; Pagano, Paolo; Gibb, Gordon; Slemzin, Vladimir; Shugay, Yulia; Veselovsky, Igor; Mackay, Duncan

    2017-04-01

    Identification of transients and their origins on the Sun is one of the most important problems of the space weather forecasting. In our work, we present a case study of the complex event consisting of several solar wind transients detected by ACE on 4 - 7 August 2011, that caused a geomagnetic storm with Dst= - 110 nT. The supposed coronal sources - three flares and coronal mass ejections (CMEs) occurred on 2 - 4 August 2011 in the active region AR 11261. To investigate the solar origins and formation of these transients, we studied kinematic and thermodynamic properties of expanding coronal structures using the SDO/AIA EUV images and the differential emission measure (DEM) diagnostics. The Helioseismic and Magnetic Imager (HMI) magnetic field maps were used as the input data for the 3D numerical model to describe the flux rope ejection. We characterize the early phase of the flux rope ejection in the corona, where the usual three-component CME structure formed. The flux rope ejected with the speed about 200 km/s to the height of 0.25 Rsun. The kinematics of the modeled CME front well agrees with the STEREO EUV measurements. Using the results of the plasma diagnostics and MHD modeling, we calculated the ion charge ratios of carbon and oxygen as well as the mean charge state of iron ions of the 2 August 2011 CME taking into account the processes of heating, cooling, expansion, ionization and recombination of the moving plasma in the corona up to the freeze-in region. We estimated a probable heating rate of the CME plasma in the low corona by matching the calculated ion composition parameters of the CME with that measured in-situ parameters of the solar wind transients. We also consider the similarities and discrepancies between the results of the MHD simulation and the observation of the event. Our results show that analysis of the ion composition of CMEs enables to disclose a relationship between parameters of the solar wind transients and properties of their

  9. Dependence of radiative stabilization on the projectile charge state after double-electron-transfer processes in slow, highly charged ion-molecule collisions

    NASA Astrophysics Data System (ADS)

    Krok, Franciszek; Tolstikhina, Inga Yu.; Sakaue, Hiroyuki A.; Yamada, Ichihiro; Hosaka, Kazumoto; Kimura, Masahiro; Nakamura, Nobuyuki; Ohtani, Shunsuke; Tawara, Hiroyuki

    1997-12-01

    We have measured the radiative stabilization probabilities after double-electron-transfer processes in slow (1.5q keV) Iq++CO collisions in the charge-state regime 8<=q<=26 by using the charge-selected-projectile-recoil-ion-coincidence method. It was found that the radiative stabilization probabilities Prad, defined as Prad=TDC/(TDC+ADC) (TDC is true double capture, and ADC autoionizing double capture), increases from about 1% at the lowest charge up to about 10% at the highest charge as the charge state of the projectile increases. A model is proposed which can explain such a feature, by incorporating a slight modification of the initial population of the transferred levels in the projectile predicted in the extended classical over-barrier model. Based upon the present model, theoretical radiative and autoionization decay rates have been calculated, using the Cowan code. Fairly good agreement between the measured and calculated results has been obtained.

  10. 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.

  11. Solid-state NMR Study of Ion Adsorption and Charge Storage in Graphene Film Supercapacitor Electrodes

    NASA Astrophysics Data System (ADS)

    Li, Kecheng; Bo, Zheng; Yan, Jianhua; Cen, Kefa

    2016-12-01

    Graphene film has been demonstrated as promising active materials for electric double layer capacitors (EDLCs), mainly due to its excellent mechanical flexibility and freestanding morphology. In this work, the distribution and variation pattern of electrolyte ions in graphene-film based EDLC electrodes are investigated with a 11B magic-angle spinning nuclear magnetic resonance (MAS-NMR) spectroscopy. For neutral graphene films soaked with different amounts of electrolytes (1 M TEABF4/ACN), weakly and strongly adsorbed anions are identified based on the resonances at different 11B chemical shifts. Unlike other porous carbonaceous materials, the strongly adsorbed anions are found as the major electrolyte anions components in graphene films. Further measurements on the ion population upon charging are carried out with applying different charging voltages on the graphene films. Results indicate that the charging process of graphene-film based EDLCs can be divided into two distinct charge storage stages (i.e., ejection of co-ions and adsorption of counter-ions) for different voltages. The as-obtained results will be useful for the design and fabrication of high performance graphene-film based EDLCs.

  12. Solid-state NMR Study of Ion Adsorption and Charge Storage in Graphene Film Supercapacitor Electrodes.

    PubMed

    Li, Kecheng; Bo, Zheng; Yan, Jianhua; Cen, Kefa

    2016-12-21

    Graphene film has been demonstrated as promising active materials for electric double layer capacitors (EDLCs), mainly due to its excellent mechanical flexibility and freestanding morphology. In this work, the distribution and variation pattern of electrolyte ions in graphene-film based EDLC electrodes are investigated with a (11)B magic-angle spinning nuclear magnetic resonance (MAS-NMR) spectroscopy. For neutral graphene films soaked with different amounts of electrolytes (1 M TEABF4/ACN), weakly and strongly adsorbed anions are identified based on the resonances at different (11)B chemical shifts. Unlike other porous carbonaceous materials, the strongly adsorbed anions are found as the major electrolyte anions components in graphene films. Further measurements on the ion population upon charging are carried out with applying different charging voltages on the graphene films. Results indicate that the charging process of graphene-film based EDLCs can be divided into two distinct charge storage stages (i.e., ejection of co-ions and adsorption of counter-ions) for different voltages. The as-obtained results will be useful for the design and fabrication of high performance graphene-film based EDLCs.

  13. Solid-state NMR Study of Ion Adsorption and Charge Storage in Graphene Film Supercapacitor Electrodes

    PubMed Central

    Li, Kecheng; Bo, Zheng; Yan, Jianhua; Cen, Kefa

    2016-01-01

    Graphene film has been demonstrated as promising active materials for electric double layer capacitors (EDLCs), mainly due to its excellent mechanical flexibility and freestanding morphology. In this work, the distribution and variation pattern of electrolyte ions in graphene-film based EDLC electrodes are investigated with a 11B magic-angle spinning nuclear magnetic resonance (MAS-NMR) spectroscopy. For neutral graphene films soaked with different amounts of electrolytes (1 M TEABF4/ACN), weakly and strongly adsorbed anions are identified based on the resonances at different 11B chemical shifts. Unlike other porous carbonaceous materials, the strongly adsorbed anions are found as the major electrolyte anions components in graphene films. Further measurements on the ion population upon charging are carried out with applying different charging voltages on the graphene films. Results indicate that the charging process of graphene-film based EDLCs can be divided into two distinct charge storage stages (i.e., ejection of co-ions and adsorption of counter-ions) for different voltages. The as-obtained results will be useful for the design and fabrication of high performance graphene-film based EDLCs. PMID:28000786

  14. 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.

  15. 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

  16. State of Charge Dependent Mechanical Integrity Behavior of 18650 Lithium-ion Batteries.

    PubMed

    Xu, Jun; Liu, Binghe; Hu, Dayong

    2016-02-25

    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.

  17. 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

  18. Reduction of the energy loss of swift molecular ions in solids due to vicinage effects in the charge state

    SciTech Connect

    Heredia-Avalos, Santiago; Garcia-Molina, Rafael

    2007-09-15

    We have calculated the energy loss of swift O{sub 2}{sup +}, N{sub 2}{sup +}, and C{sub n}{sup +} (n=2-60) molecular ions moving through an amorphous carbon target. The dielectric formalism is used to evaluate the vicinage effects in the energy loss of the atomic ions that form the molecular projectile, but we take into account that the charge state of these atomic ions is affected by their correlated motion through the target and by the screened Coulomb potential between them. When vicinage effects in the charge state are taken into account, the Coulomb repulsion is weakened, leading to a reduction in the interatomic separations ({approx}3% for N{sub 2}{sup +} and {approx}9% for C{sub 60}{sup +}, both having similar velocities). These charge state effects can be neglected for diatomic molecular ions, but they give rise to a reduction of {approx}8% in the vicinage effects in the energy loss of larger molecular ions with cage like geometrical structures, like C{sub n}{sup +} (n=20,60) projectiles.

  19. Magnetic latitude dependence of oxygen charge states in the global magnetosphere: Insights into solar wind-originating ion injection

    NASA Astrophysics Data System (ADS)

    Allen, R. C.; Livi, S. A.; Vines, S. K.; Goldstein, J.

    2016-10-01

    Understanding the sources and subsequent evolution of plasma in a magnetosphere holds intrinsic importance for magnetospheric dynamics. Previous studies have investigated the balance of ionospheric-originating heavy ions (low charge state) from those of solar wind origin (high charge state) in the magnetosphere of Earth. These studies have suggested a variety of entry mechanisms for solar wind ions to penetrate into the magnetosphere. Following from recently published distributions for oxygen charge states observed by the Polar spacecraft, this paper investigates oxygen charge state flux distributions versus L shell and magnetic latitude. By showing these distributions in this frame, and binning by various proxies for magnetospheric dynamics (Dst, AE, VSW∗BZ, Pdyn), insight has been gained into the underlying physics at play for oxygen injection. Ionospheric-originating oxygen is observed to depend predominantly on Dst, whereas solar wind-originating oxygen is observed to have a strong dependence on solar wind dynamic pressure (Pdyn) at the flanks and on VSW∗BZ at the dayside. This suggests that both Kelvin-Helmholtz instabilities and reconnection play major roles in solar wind ion penetration into a magnetosphere. Additionally, the near-Earth magnetotail reconnection site does not seem to be a major injection site of solar wind-originating plasma in the 1 to 200 keV/e energy range.

  20. Acceleration of high charge-state target ions in high-intensity laser interactions with sub-micron targets

    NASA Astrophysics Data System (ADS)

    McGuffey, C.; Raymond, A.; Batson, T.; Hua, R.; Petrov, G. M.; Kim, J.; Krauland, C. M.; Maksimchuk, A.; Thomas, A. G. R.; Yanovsky, V.; Krushelnick, K.; Beg, F. N.

    2016-11-01

    We have studied laser acceleration of ions from Si3N4 and Al foils ranging in thickness from 1800 to 8 nm with particular interest in acceleration of ions from the bulk of the target. The study includes results of experiments conducted with the HERCULES laser with pulse duration 40 fs and intensity 3 × 1020 W cm-2 and corresponding two-dimensional particle-in-cell simulations. When the target thickness was reduced the distribution of ion species heavier than protons transitioned from being dominated by carbon contaminant ions of low ionization states to being dominated by high ionization states of bulk ions (such as Si12+) and carbon. Targets in the range 50-150 nm yielded dramatically greater particle number and higher ion maximum energy for these high ionization states compared to thicker targets typifying the Target Normal Sheath Acceleration (TNSA) regime. The high charge states persisted for the thinnest targets, but the accelerated particle numbers decreased for targets 35 nm and thinner. This transition to an enhanced ion TNSA regime, which more efficiently generates ion beams from the bulk target material, is also seen in the simulations.

  1. 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.

  2. Highly charged ion secondary ion mass spectroscopy

    DOEpatents

    Hamza, Alex V.; Schenkel, Thomas; Barnes, Alan V.; Schneider, Dieter H.

    2001-01-01

    A secondary ion mass spectrometer using slow, highly charged ions produced in an electron beam ion trap permits ultra-sensitive surface analysis and high spatial resolution simultaneously. The spectrometer comprises an ion source producing a primary ion beam of highly charged ions that are directed at a target surface, a mass analyzer, and a microchannel plate detector of secondary ions that are sputtered from the target surface after interaction with the primary beam. The unusually high secondary ion yield permits the use of coincidence counting, in which the secondary ion stops are detected in coincidence with a particular secondary ion. The association of specific molecular species can be correlated. The unique multiple secondary nature of the highly charged ion interaction enables this new analytical technique.

  3. Optimization of a charge-state analyzer for electron cyclotron resonance ion source beams.

    PubMed

    Saminathan, S; Beijers, J P M; Kremers, H R; Mironov, V; Mulder, J; Brandenburg, S

    2012-07-01

    A detailed experimental and simulation study of the extraction of a 24 keV He(+) beam from an ECR ion source and the subsequent beam transport through an analyzing magnet is presented. We find that such a slow ion beam is very sensitive to space-charge forces, but also that the neutralization of the beam's space charge by secondary electrons is virtually complete for beam currents up to at least 0.5 mA. The beam emittance directly behind the extraction system is 65 π mm mrad and is determined by the fact that the ion beam is extracted in the strong magnetic fringe field of the ion source. The relatively large emittance of the beam and its non-paraxiality lead, in combination with a relatively small magnet gap, to significant beam losses and a five-fold increase of the effective beam emittance during its transport through the analyzing magnet. The calculated beam profile and phase-space distributions in the image plane of the analyzing magnet agree well with measurements. The kinematic and magnet aberrations have been studied using the calculated second-order transfer map of the analyzing magnet, with which we can reproduce the phase-space distributions of the ion beam behind the analyzing magnet. Using the transfer map and trajectory calculations we have worked out an aberration compensation scheme based on the addition of compensating hexapole components to the main dipole field by modifying the shape of the poles. The simulations predict that by compensating the kinematic and geometric aberrations in this way and enlarging the pole gap the overall beam transport efficiency can be increased from 16% to 45%.

  4. Laser ion sources for highly charged ions (invited)

    NASA Astrophysics Data System (ADS)

    Sherwood, T. R.

    1992-04-01

    The development of laser ion sources is reviewed in the light of possible future requirement for highly charged ions at CERN. After the advent of high power Q-switched pulsed lasers in the 1960's, there were a number of proposals to use the laser produced plasma as sources of ions. Such ion sources have been constructed for a number of uses, and in particular, for injection of ions into particle accelerators. At CERN, a new test facility has recently started operation. Initial results indicate ion currents in excess of 5 mA for lead ions with charge state about 20.

  5. Generation of high charge state platinum ions on vacuum arc plasma heated by gyrotron radiation.

    PubMed

    Yushkov, G Yu; Vodopyanov, A V; Nikolaev, A G; Izotov, I V; Savkin, K P; Golubev, S V; Oks, E M

    2014-02-01

    The hybrid high charge metal ion source based on vacuum arc plasma heated by gyrotron radiation into simple magnetic trap has been developed. Two types of magnetic traps were used: a mirror configuration and a cusp one with inherent "minimum-B" structure. Pulsed high power (>100 kW) gyrotrons with frequency 37.5 GHz and 75 GHz were used for heating the vacuum arc plasma injected into the traps. Two different ways were used for injecting the metal plasma-axial injection by a miniature arc source located on-axis near the microwave window, and simultaneous radial injection by a number of sources mounted radially at the midplane of the traps. This article represents all data gathered for platinum ions, thus making comparison of the experimental results obtained with different traps and injections convenient and accurate.

  6. High intensity production of high and medium charge state uranium and other heavy ion beams with VENUS

    SciTech Connect

    Leitner, D.; Galloway, M. L.; Loew, T. J.; Lyneis, C. M.; Castro Rodriguez, I.; Todd, D. S.

    2008-02-15

    The next generation, superconducting electron cyclotron resonance (ECR) ion source VENUS (versatile ECR ion source for nuclear science) started operation with 28 GHz microwave heating in 2004. Since then it has produced world record ion beam intensities. For example, 2850 e {mu}A of O{sup 6+}, 200 e {mu}A of U{sup 33+} or U{sup 34+}, and in respect to high charge state ions, 1 e {mu}A of Ar{sup 18+}, 270 e {mu}A of Ar{sup 16+}, 28 e {mu}A of Xe{sup 35+}, and 4.9 e {mu}A of U{sup 47+} have been produced. A brief overview of the latest developments leading to these record intensities is given and the production of high intensity uranium beams is discussed in more detail.

  7. 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.

  8. Generation of high charge state metal ion beams by electron cyclotron resonance heating of vacuum arc plasma in cusp trap.

    PubMed

    Nikolaev, A G; Savkin, K P; Oks, E M; Vizir, A V; Yushkov, G Yu; Vodopyanov, A V; Izotov, I V; Mansfeld, D A

    2012-02-01

    A method for generating high charge state heavy metal ion beams based on high power microwave heating of vacuum arc plasma confined in a magnetic trap under electron cyclotron resonance conditions has been developed. A feature of the work described here is the use of a cusp magnetic field with inherent "minimum-B" structure as the confinement geometry, as opposed to a simple mirror device as we have reported on previously. The cusp configuration has been successfully used for microwave heating of gas discharge plasma and extraction from the plasma of highly charged, high current, gaseous ion beams. Now we use the trap for heavy metal ion beam generation. Two different approaches were used for injecting the vacuum arc metal plasma into the trap--axial injection from a miniature arc source located on-axis near the microwave window, and radial injection from sources mounted radially at the midplane of the trap. Here, we describe preliminary results of heating vacuum arc plasma in a cusp magnetic trap by pulsed (400 μs) high power (up to 100 kW) microwave radiation at 37.5 GHz for the generation of highly charged heavy metal ion beams.

  9. Generation of high charge state metal ion beams by electron cyclotron resonance heating of vacuum arc plasma in cusp trapa)

    NASA Astrophysics Data System (ADS)

    Nikolaev, A. G.; Savkin, K. P.; Oks, E. M.; Vizir, A. V.; Yushkov, G. Yu.; Vodopyanov, A. V.; Izotov, I. V.; Mansfeld, D. A.

    2012-02-01

    A method for generating high charge state heavy metal ion beams based on high power microwave heating of vacuum arc plasma confined in a magnetic trap under electron cyclotron resonance conditions has been developed. A feature of the work described here is the use of a cusp magnetic field with inherent "minimum-B" structure as the confinement geometry, as opposed to a simple mirror device as we have reported on previously. The cusp configuration has been successfully used for microwave heating of gas discharge plasma and extraction from the plasma of highly charged, high current, gaseous ion beams. Now we use the trap for heavy metal ion beam generation. Two different approaches were used for injecting the vacuum arc metal plasma into the trap - axial injection from a miniature arc source located on-axis near the microwave window, and radial injection from sources mounted radially at the midplane of the trap. Here, we describe preliminary results of heating vacuum arc plasma in a cusp magnetic trap by pulsed (400 μs) high power (up to 100 kW) microwave radiation at 37.5 GHz for the generation of highly charged heavy metal ion beams.

  10. Generation of high charge state metal ion beams by electron cyclotron resonance heating of vacuum arc plasma in cusp trap

    SciTech Connect

    Nikolaev, A. G.; Savkin, K. P.; Oks, E. M.; Vizir, A. V.; Yushkov, G. Yu.; Vodopyanov, A. V.; Izotov, I. V.; Mansfeld, D. A.

    2012-02-15

    A method for generating high charge state heavy metal ion beams based on high power microwave heating of vacuum arc plasma confined in a magnetic trap under electron cyclotron resonance conditions has been developed. A feature of the work described here is the use of a cusp magnetic field with inherent ''minimum-B'' structure as the confinement geometry, as opposed to a simple mirror device as we have reported on previously. The cusp configuration has been successfully used for microwave heating of gas discharge plasma and extraction from the plasma of highly charged, high current, gaseous ion beams. Now we use the trap for heavy metal ion beam generation. Two different approaches were used for injecting the vacuum arc metal plasma into the trap - axial injection from a miniature arc source located on-axis near the microwave window, and radial injection from sources mounted radially at the midplane of the trap. Here, we describe preliminary results of heating vacuum arc plasma in a cusp magnetic trap by pulsed (400 {mu}s) high power (up to 100 kW) microwave radiation at 37.5 GHz for the generation of highly charged heavy metal ion beams.

  11. Charge exchange ionization in collision cells as a method to detect the presence of long-lived excited electronic states of polyatomic ions.

    PubMed

    Kwon, C H; Kim, M S; Choe, J C

    2001-10-01

    Charge exchange ionization in collision cells installed in a double focusing mass spectrometer with reversed geometry has been used to detect the presence of a long-lived excited electronic state of benzene ion. In particular, the first collision cell located between the ion source and the magnetic sector was modified to serve as an ion source for the reagent ion generated by charge exchange with the primary ion. Strong reagent ion signals were observed when the ionization energies of the reagents (1,3-C4H6, CS2, CH3Cl) were lower than the recombination energy (approximately 11.5 eV) of the excited state benzene ion, while the signals were negligible for reagents (CH3F,CH4) with higher ionization energy. The fact that a strong signal is observable only for electronically exoergic charge exchange is useful for detecting the presence of a long-lived electronically excited state.

  12. 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.

  13. Charge state of C10 and C5 energetic cluster ions in amorphous carbon targets: simulations

    NASA Astrophysics Data System (ADS)

    Nardi, E.; Tombrello, T. A.

    2006-12-01

    We present here detailed simulations of the interaction of energetic C10 and C5 clusters at the energies of 1, 2, and 4 MeV per carbon atom with an amorphous carbon target. The spatial evolution of the cluster components is simulated accounting for both scattering and Coulomb explosion. The former is calculated by means of the Monte Carlo method while the latter is computed by means of molecular dynamics. The charge state of the individual cluster components is calculated as a function of penetration depth, and is determined by the competition between electron ionization and recombination. The results of calculations of the effect of the neighbouring cluster components on the suppression of the values of the charge state are presented and compared to the experimental values of Brunelle et al. Charge state suppression calculations for the 2 MeV/C clusters for both C10 and C5 agree well with the experimental results for penetration depths of less than about 500 and 250 Å respectively, assuming the intracluster Coulomb potential is screened by four target valence electrons. At 4 MeV/C the results are similar although less screening is required; a possible explanation is the inability of the plasma to completely screen the higher velocity projectiles. The 1 MeV/C calculated results however differ in their behaviour from the 2 and 4 MeV/C cases.

  14. ION PRODUCING MECHANISM (CHARGE CUPS)

    DOEpatents

    Brobeck, W.W.

    1959-04-21

    The problems of confining a charge material in a calutron and uniformly distributing heat to the charge is described. The charge is held in a cup of thermally conductive material removably disposed within the charge chamber of the ion source block. A central thermally conducting stem is incorporated within the cup for conducting heat to the central portion of the charge contained within the cup.

  15. Excited-state energies and fine structure of highly charged lithiumlike ions

    NASA Astrophysics Data System (ADS)

    Li, Jin-ying; Ding, Da-jun; Wang, Zhi-wen

    2013-10-01

    The full-core-plus-correlation method (FCPC) is extended to calculate the energies and fine structures of 1s2nd and 1s2nf (n≤5) states for the lithiumlike systems with high nuclear charge from Z = 41 to 50. In calculating energy, the higher-order relativistic contribution is estimated under a hydrogenic approximation. The nonrelativistic energies and wave functions are calculated by the Rayleigh-Ritz method. The mass polarization and the relativistic corrections including the kinetic energy correction, the Darwin term, the electron-electron contact term, and the orbit-orbit interaction are calculated perturbatively as the first-order correction. The quantum-electrodynamics contributions to the energy and to the fine-structure splitting are estimated by using the effective nuclear charge formula. The excited energies, the fine structures, and other relevant term energies are given and compared with the data available in the literature.

  16. Charge states of low energy ions from the sun. Ph.D. Thesis

    NASA Technical Reports Server (NTRS)

    Sciambi, R. K.

    1975-01-01

    Measurements of ionization states and energy spectra of carbon, oxygen, and iron accelerated in ten solar flare particle events are reported, for energies between 15 keV per nucleon and 600 keV per nucleon. The ionization states were remarkably constant from flare to flare, despite great variations in other event parameters. The mean ionization state for carbon was 5.7, for oxygen 6.2, and for iron 11.7, values which are similar to the respective ionization states in the solar wind. The time profile of the He/C+N+O ratio was examined, and it was found that the ratio was small early in the event, and increased with time. The energy spectra of the medium ions showed a flattening below 100 keV per nucleon, which was highly correlated with event size as measured by the event averaged flux of 130 to 220 keV protons.

  17. 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.

  18. Results from the Heavy Ions In Space (HIIS) experiment on the ionic charge state of solar energetic particles

    NASA Technical Reports Server (NTRS)

    Tylka, Allan J.; Boberg, Paul R.; Adams, James H., Jr.; Beahm, Lorraine P.; Kleis, Thomas

    1995-01-01

    It has long been known that low-energy solar energetic particles (SEP's) are partially-ionized. For example, in large, so-called 'gradual' solar energetic particle events, at approximately 1 MeV/nucleon the measured mean ionic charge state, Q, of Fe ions is 14.1 +/- 0.2, corresponding to a plasma temperature of approximately 2 MK in the coronal or solar-wind source material. Recent studies, which have greatly clarified the origin of solar energetic particles and their relation to solar flares, suggest that ions in these SEP events are accelerated not at a flare site, but by shocks propagating through relatively low-density regions in the interplanetary medium. As a result, the partially-ionized states observed at low energies are expected to continue to higher energies. However, up to now there have been no high-energy measurements of ionic charge states to confirm this notion. We report here HIIS observations of Fe-group ions at 50-600 MeV/nucleon, at energies and fluences which cannot be explained by fully-ionized galactic cosmic rays, even in the presence of severe geomagnetic cutoff suppression. Above approximately 200 MeV/nucleon, all features of our data -- fluence, energy spectrum, elemental composition, and arrival directions -- can be explained by the large SEP events of October 1989, provided that the mean ionic charge state at these high energies is comparable to the measured value at approximately 1 MeV/nucleon. By comparing the HIIS observations with measurements in interplanetary space in October 1989, we determine the mean ionic charge state of SEP Fe ions at approximately 200-600 MeV/nucleon to be Q = 13.4 plus or minus 1.0, in good agreement with the observed value at approximately 1 MeV/nucleon. The source of the ions below approximately 200 MeV/nucleon is not yet clear. Partially-ionized ions are less effectively deflected by the Earth's magnetic field than fully-ionized cosmic rays and therefore have greatly enhanced access to low-Earth orbit

  19. BREIT code: Analytical solution of the balance rate equations for charge-state evolutions of heavy-ion beams in matter

    NASA Astrophysics Data System (ADS)

    Winckler, N.; Rybalchenko, A.; Shevelko, V. P.; Al-Turany, M.; Kollegger, T.; Stöhlker, Th.

    2017-02-01

    A detailed description of a recently developed BREIT computer code (Balance Rate Equations of Ion Transportation) for calculating charge-state fractions of ion beams passing through matter is presented. The code is based on the analytical solutions of the differential balance equations for the charge-state fractions as a function of the target thickness and can be used for calculating the ion evolutions in gaseous, solid and plasma targets. The BREIT code is available on-line and requires the charge-changing cross sections and initial conditions in the input file. The eigenvalue decomposition method, applied to obtain the analytical solutions of the rate equations, is described in the paper. Calculations of non-equilibrium and equilibrium charge-state fractions, performed by the BREIT code, are compared with experimental data and results of other codes for ion beams in gaseous and solid targets. Ability and limitations of the BREIT code are discussed in detail.

  20. Measurements of charge state distributions of 0.74 and 1.4 MeV /u heavy ions passing through dilute gases

    NASA Astrophysics Data System (ADS)

    Scharrer, P.; Düllmann, Ch. E.; Barth, W.; Khuyagbaatar, J.; Yakushev, A.; Bevcic, M.; Gerhard, P.; Groening, L.; Horn, K. P.; Jäger, E.; Krier, J.; Vormann, H.

    2017-04-01

    In many modern heavy-ion accelerator facilities, gas strippers are used to increase the projectile charge state for improving the acceleration efficiency of ion beams to higher energies. For this application, the knowledge on the behavior of charge state distributions of heavy-ions after passing through dilute gases is of special interest. Charge state distributions of uranium (238U), bismuth (209Bi), titanium (50Ti), and argon (40Ar) ion beams with energies of 0.74 MeV /u and 1.4 MeV /u after passing through hydrogen (H2 ), helium (He), carbon dioxide (CO2 ), nitrogen (N2 ), oxygen (O2 ), neon (Ne), and argon (Ar) gases were measured. Gas stripper target thicknesses up to 100 μ g /cm2 were applied. The observed behavior of the charge state distributions, including their width and mean charge state, are discussed. The measurements show the highest equilibrium charge state at 1.4 MeV /u for 238U on H2 gas of 29.2 ±1.2 . Narrow charge state distributions are observed for 238U and 209Bi on H2 and He gas, which are highly beneficial, e.g., for the production of beams of high intensities in accelerators.

  1. 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.

  2. 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.

  3. Space Charge Layer Effect in Solid State Ion Conductors and Lithium Batteries: Principle and Perspective.

    PubMed

    Chen, Cheng; Guo, Xiangxin

    2016-01-01

    The space charge layer (SCL) effects were initially developed to explain the anomalous conductivity enhancement in composite ionic conductors. They were further extended to qualitatively as well as quantitatively understand the interfacial phenomena in many other ionic-conducting systems. Especially in nanometre-scale systems, the SCL effects could be used to manipulate the conductivity and construct artificial conductors. Recently, existence of such effects either at the electrolyte/cathode interface or at the interfaces inside the composite electrode in all solid state lithium batteries (ASSLB) has attracted attention. Therefore, in this article, the principle of SCL on basis of defect chemistry is first presented. The SCL effects on the carrier transport and storage in typical conducting systems are reviewed. For ASSLB, the relevant effects reported so far are also reviewed. Finally, the perspective of interface engineer related to SCL in ASSLB is addressed.

  4. Internal potential mapping of charged solid-state-lithium ion batteries using in situ Kelvin probe force microscopy.

    PubMed

    Masuda, Hideki; Ishida, Nobuyuki; Ogata, Yoichiro; Ito, Daigo; Fujita, Daisuke

    2017-01-05

    Solid-state-lithium ion batteries (SS-LIBs) are a promising candidate for next-generation energy storage devices. Novel methods for characterizing electrochemical reactions occurring during battery operation at the nanoscale are highly required for understanding the fundamental working principle and improving the performance of the devices. In this work, we combined Ar ion milling under non-atmospheric conditions with in situ cross-sectional Kelvin probe force microscopy (KPFM) for direct imaging of the internal electrical potential distribution of the SS-LIBs. We succeeded in the direct visualization of the change in the potential distribution of a cathode composite electrode (a mixture of the active materials, solid electrolytes, and conductive additives) arising from battery charging (electrochemical reaction). The observed results provided several insights into battery operation, such as the behavior of Li ions and inhomogeneity of electrochemical reactions in the electrode. Our method paves the way to characterize the fundamental aspects of SS-LIBs for the improvement of device performance, including the evaluation of the distribution of the Li ion depleted regions, visualization of the conductive paths, and analysis of the cause of degradation.

  5. Multiply-charged ions and interstellar chemistry.

    PubMed

    Böhme, Diethard Kurt

    2011-11-07

    Gaseous molecules and ions, and even dust grains, can accumulate charge in the interstellar medium (ISM) by harvesting the energy of UV photons, cosmic rays, helium ions and metastable atoms. This Perspective views the various modes of gas-phase formation of multiply-charged cations and the possible impact of their reactions on the chemical and ionization structure of the ISM, in the light of what is still very limited knowledge. Emphasis is given to gas-phase reactions of multiply-charged cations with atoms, molecules and electrons that lead to charge reduction, charge separation and chemical bond formation and these are examined for multiply-charged atoms, small molecules, hydrocarbons, polycyclic aromatic hydrocarbons and fullerenes, primarily as dications but also as a function of charge state. The increased electrostatic interaction due to multiple charge is seen to promote bonding to individual charge sites on large molecules (e.g. fullerenes) and allow ensuing "surface" chemistry under the influence of Coulomb repulsion. The unique ability of multiply charged cations to undergo charge separation reactions, either unimolecular or bimolecular, can feature in the production in the ISM of internally cold, but translationally hot, cations of lower charge state or hot atoms that may provide the driving force for subsequent chemical reactions in what is otherwise an ultracold environment. Available chemical kinetic models that account for the role of multiply-charged ions in the ISM are few and of limited scope and the observation of these ions in the ISM has remained elusive. This journal is © the Owner Societies 2011

  6. Charge-State-Resolved Ion Energy Distribution Functions ofCathodic Vacuum Arcs: A Study Involving the Plasma Potential and BiasedPlasmas

    SciTech Connect

    Anders, Andre; Oks, Efim

    2006-03-09

    There are divergent results in the literature on the(in)dependence of the ion velocity distribution functions on the ioncharge states. Apparently, most time-of-flight methods of measurementsindicate independence whereas most measurements with electrostaticanalyzers state the opposite. It is shown here that this grouping iscoincidental with investigations of pulsed and continuous arcs. Allresults can be consolidated by taking ion-neutral interaction intoaccount, especially charge exchange collisions with the metal neutralsproduced by the arc itself. The velocity distribution functions areindependent of charge state when produced at cathode spots but becomecharge-state dependent when the plasma interacts withneutrals.

  7. Charge state effect on Si K X-ray emission induced by Iq+ ions impacting

    NASA Astrophysics Data System (ADS)

    Lei, Yu; Zhao, Yongtao; Cheng, Rui; Zhou, Xianming; Sun, Yuanbo; Wang, Xing; Wang, Yuyu; Ren, Jieru; Li, Yongfeng; Yu, Yang; Liu, Shidong; Xu, Ge

    2014-04-01

    K X-ray emission of Si induced by Iq+ (q=20, 22, 25) ion impact has been investigated. The results show a much higher intensity of X-ray emission for I25+ ions bombardment compared to I20+ and I22+ ions. The experimental data are explained within the framework of 3dπ, δ-3dσ rotational coupling.

  8. Production and ion-ion cooling of highly charged ions in electron string ion source.

    PubMed

    Donets, D E; Donets, E D; Donets, E E; Salnikov, V V; Shutov, V B; Syresin, E M

    2009-06-01

    The scheme of an internal injection of Au atoms into the working space of the "Krion-2" electron string ion source (ESIS) was applied and tested. In this scheme Au atoms are evaporated from the thin tungsten wire surface in vicinity of the source electron string. Ion beams with charge states up to Au51+ were produced. Ion-ion cooling with use of C and O coolant ions was studied. It allowed increasing of the Au51+ ion yield by a factor of 2. Ions of Kr up to charge state 28+ were also produced in the source. Electron strings were first formed with injection electron energy up to 6 keV. Methods to increase the ESIS ion output are discussed.

  9. On state-of-charge determination for lithium-ion batteries

    NASA Astrophysics Data System (ADS)

    Li, Zhe; Huang, Jun; Liaw, Bor Yann; Zhang, Jianbo

    2017-04-01

    Accurate estimation of state-of-charge (SOC) of a battery through its life remains challenging in battery research. Although improved precisions continue to be reported at times, almost all are based on regression methods empirically, while the accuracy is often not properly addressed. Here, a comprehensive review is set to address such issues, from fundamental principles that are supposed to define SOC to methodologies to estimate SOC for practical use. It covers topics from calibration, regression (including modeling methods) to validation in terms of precision and accuracy. At the end, we intend to answer the following questions: 1) can SOC estimation be self-adaptive without bias? 2) Why Ah-counting is a necessity in almost all battery-model-assisted regression methods? 3) How to establish a consistent framework of coupling in multi-physics battery models? 4) To assess the accuracy in SOC estimation, statistical methods should be employed to analyze factors that contribute to the uncertainty. We hope, through this proper discussion of the principles, accurate SOC estimation can be widely achieved.

  10. Temperature dependency of state of charge inhomogeneities and their equalization in cylindrical lithium-ion cells

    NASA Astrophysics Data System (ADS)

    Osswald, P. J.; Erhard, S. V.; Rheinfeld, A.; Rieger, B.; Hoster, H. E.; Jossen, A.

    2016-10-01

    The influence of cell temperature on the current density distribution and accompanying inhomogeneities in state of charge (SOC) during cycling is analyzed in this work. To allow for a detailed insight in the electrochemical behavior of the cell, commercially available 26650 cells were modified to allow for measuring local potentials at four different, nearly equidistant positions along the electrodes. As a follow-up to our previous work investigating local potentials within a cell, we apply this method for studying SOC deviations and their sensitivity to cell temperature. The local potential distribution was studied during constant current discharge operations for various current rates and discharge pulses in order to evoke local inhomogeneities for temperatures ranging from 10 °C to 40 °C. Differences in local potentials were considered for estimating local SOC variations within the electrodes. It could be observed that even low currents such as 0.1C can lead to significant inhomogeneities, whereas a higher cell temperature generally results in more pronounced inhomogeneities. A rapid SOC equilibration can be observed if the variation in the SOC distribution corresponds to a considerable potential difference defined by the open circuit voltage of either the positive or negative electrode. With increasing temperature, accelerated equalization effects can be observed.

  11. Detection method for dissociation of multiple-charged ions

    DOEpatents

    Smith, Richard D.; Udseth, Harold R.; Rockwood, Alan L.

    1991-01-01

    Dissociations of multiple-charged ions are detected and analyzed by charge-separation tandem mass spectrometry. Analyte molecules are ionized to form multiple-charged parent ions. A particular charge parent ion state is selected in a first-stage mass spectrometer and its mass-to-charge ratio (M/Z) is detected to determine its mass and charge. The selected parent ions are then dissociated, each into a plurality of fragments including a set of daughter ions each having a mass of at least one molecular weight and a charge of at least one. Sets of daughter ions resulting from the dissociation of one parent ion (sibling ions) vary in number but typically include two to four ions, one or more multiply-charged. A second stage mass spectrometer detects mass-to-charge ratio (m/z) of the daughter ions and a temporal or temporo-spatial relationship among them. This relationship is used to correlate the daughter ions to determine which (m/z) ratios belong to a set of sibling ions. Values of mass and charge of each of the sibling ions are determined simultaneously from their respective (m/z) ratios such that the sibling ion charges are integers and sum to the parent ion charge.

  12. Element- and charge-state-resolved ion energies in the cathodic arc plasma from composite AlCr cathodes in argon, nitrogen and oxygen atmospheres

    PubMed Central

    Franz, Robert; Polcik, Peter; Anders, André

    2015-01-01

    The energy distribution functions of ions in the cathodic arc plasma using composite AlCr cathodes were measured as a function of the background gas pressure in the range 0.5 to 3.5 Pa for different cathode compositions and gas atmospheres. The most abundant aluminium ions were Al+ regardless of the background gas species, whereas Cr2+ ions were dominating in Ar and N2 and Cr+ in O2 atmospheres. The energy distributions of the aluminium and chromium ions typically consisted of a high-energy fraction due to acceleration in the expanding plasma plume from the cathode spot and thermalised ions that were subjected to collisions in the plasma cloud. The fraction of the latter increased with increasing background gas pressure. Atomic nitrogen and oxygen ions showed similar energy distributions as the aluminium and chromium ions, whereas the argon and molecular nitrogen and oxygen ions were formed at greater distance from the cathode spot and thus less subject to accelerating gradients. In addition to the positively charged metal and gas ions, negatively charged oxygen and oxygen-containing ions were observed in O2 atmosphere. The obtained results are intended to provide a comprehensive overview of the ion energies and charge states in the arc plasma of AlCr composite cathodes in different gas atmospheres as such plasmas are frequently used to deposit thin films and coatings. PMID:26120236

  13. Element- and charge-state-resolved ion energies in the cathodic arc plasma from composite AlCr cathodes in argon, nitrogen and oxygen atmospheres

    DOE PAGES

    Franz, Robert; Polcik, Peter; Anders, André

    2015-06-01

    The energy distribution functions of ions in the cathodic arc plasma using composite AlCr cathodes were measured as a function of the background gas pressure in the range 0.5 to 3.5 Pa for different cathode compositions and gas atmospheres. The most abundant aluminium ions were Al+ regardless of the background gas species, whereas Cr2+ ions were dominating in Ar and N2 and Cr+ in O2 atmospheres. The energy distributions of the aluminium and chromium ions typically consisted of a high-energy fraction due to acceleration in the expanding plasma plume from the cathode spot and thermalised ions that were subjected tomore » collisions in the plasma cloud. The fraction of the latter increased with increasing background gas pressure. Atomic nitrogen and oxygen ions showed similar energy distributions as the aluminium and chromium ions, whereas the argon and molecular nitrogen and oxygen ions were formed at greater distance from the cathode spot and thus less subject to accelerating gradients. In addition to the positively charged metal and gas ions, negatively charged oxygen and oxygen-containing ions were observed in O2 atmosphere. The obtained results are intended to provide a comprehensive overview of the ion energies and charge states in the arc plasma of AlCr composite cathodes in different gas atmospheres as such plasmas are frequently used to deposit thin films and coatings.« less

  14. Element- and charge-state-resolved ion energies in the cathodic arc plasma from composite AlCr cathodes in argon, nitrogen and oxygen atmospheres.

    PubMed

    Franz, Robert; Polcik, Peter; Anders, André

    2015-06-25

    The energy distribution functions of ions in the cathodic arc plasma using composite AlCr cathodes were measured as a function of the background gas pressure in the range 0.5 to 3.5 Pa for different cathode compositions and gas atmospheres. The most abundant aluminium ions were Al(+) regardless of the background gas species, whereas Cr(2+) ions were dominating in Ar and N2 and Cr(+) in O2 atmospheres. The energy distributions of the aluminium and chromium ions typically consisted of a high-energy fraction due to acceleration in the expanding plasma plume from the cathode spot and thermalised ions that were subjected to collisions in the plasma cloud. The fraction of the latter increased with increasing background gas pressure. Atomic nitrogen and oxygen ions showed similar energy distributions as the aluminium and chromium ions, whereas the argon and molecular nitrogen and oxygen ions were formed at greater distance from the cathode spot and thus less subject to accelerating gradients. In addition to the positively charged metal and gas ions, negatively charged oxygen and oxygen-containing ions were observed in O2 atmosphere. The obtained results are intended to provide a comprehensive overview of the ion energies and charge states in the arc plasma of AlCr composite cathodes in different gas atmospheres as such plasmas are frequently used to deposit thin films and coatings.

  15. Current sensor-less state-of-charge estimation algorithm for lithium-ion batteries utilizing filtered terminal voltage

    NASA Astrophysics Data System (ADS)

    Chun, Chang Yoon; Baek, Jongbok; Seo, Gab-Su; Cho, B. H.; Kim, Jonghoon; Chang, Il Kwon; Lee, Sangwoo

    2015-01-01

    This paper proposes state-of-charge (SOC) estimation algorithms that utilize a filtered battery terminal voltage without measuring the current. These methods extract an estimated open-circuit voltage (OCV) or current from the battery terminal voltage through equivalent circuit model-based filters, which streamlines the estimation process. In the methods, the OCV values derived from the corresponding SOCs are used to extract the filter coefficient for ease of implementation. The relationship between the model's accuracy and estimation performance is investigated, and the variation of the SOC estimation error due to the model parameter tolerance is also derived by the Monte Carlo simulation tool to confirm the practicality of the method. To validate the performance of the proposed approach, a parameter extraction profile and an actual mobile phone profile are applied to a 2.6 Ah prismatic Li-ion battery. The experimental results show the feasibility of the proposed SOC estimation algorithm to within a 5% SOC estimation error.

  16. Tailoring Ion Charge State Distribution in Tetramethyltin Clusters under Influence of Moderate Intensity Picosecond Laser Pulse: Role of Laser Wavelength and Rate of Energy Deposition

    NASA Astrophysics Data System (ADS)

    Sharma, Pramod; Das, Soumitra; Vatsa, Rajesh K.

    2017-07-01

    Systematic manipulation of ionic-outcome in laser-cluster interaction process has been realized for studies carried out on tetramethyltin (TMT) clusters under picosecond laser conditions, determined by choice of laser wavelength and intensity. As a function of laser intensity, TMT clusters exhibit gradual enhancement in overall ionization of its cluster constituents, up to a saturation level of ionization, which was distinct for different wavelengths (266, 355, and 532 nm). Simultaneously, systematic appearance of higher multiply charged atomic ions and shift in relative abundance of multiply charged atomic ions towards higher charge state was observed, using time-of-flight mass spectrometer. At saturation level, multiply charged atomic ions up to (C2+, Sn2+) at 266 nm, (C4+, Sn4+) at 355 nm, and (C4+, Sn6+) at 532 nm were detected. In addition, at 355 nm intra-cluster ion chemistry within the ionized cluster leads to generation of molecular hydrogen ion (H2 +) and triatomic molecular hydrogen ion (H3 +). Generation of multiply charged atomic ions is ascribed to efficient coupling of laser pulse with the cluster media, facilitated by inner-ionized electrons produced within the cluster, at the leading edge of laser pulse. Role of inner-ionized electrons is authenticated by measuring kinetic energy distribution of electrons liberated upon disintegration of excessively ionized cluster, under the influence of picosecond laser pulse.

  17. Hydration of highly charged ions.

    PubMed

    Hofer, Thomas S; Weiss, Alexander K H; Randolf, Bernhard R; Rode, Bernd M

    2011-08-01

    Based on a series of ab initio quantum mechanical charge field molecular dynamics (QMCF MD) simulations, the broad spectrum of structural and dynamical properties of hydrates of trivalent and tetravalent ions is presented, ranging from extreme inertness to immediate hydrolysis. Main group and transition metal ions representative for different parts of the periodic system are treated, as are 2 threefold negatively charged anions. The results show that simple predictions of the properties of the hydrates appear impossible and that an accurate quantum mechanical simulation in cooperation with sophisticated experimental investigations seems the only way to obtain conclusive results.

  18. Highly-Charged Ions in Traps - Progress and Opportunities

    NASA Astrophysics Data System (ADS)

    Church, D. A.; Schneider, D.; Steiger, J.; Beck, B. R.; Holder, J. P.; Weinberg, G.; Gruber, L.; Moehs, D. P.; McDonald, J.

    Penning and Kingdon ion traps have been used to study low-energy multiply-charged ions with charge states up to 80+ during the last few years. The ions have been captured into the traps from beams of external multiply-charged ion sources, or have been produced inside the trap. Measurements of cross sections for electron capture from neutrals to ions and studies of relative double electron capture rates have been completed. The lifetimes of metastable levels of ions, precision spectroscopy on multiply-charged ions in traps, and cooling of trapped ions using lasers, ion-ion elastic collisions, and parallel-tuned circuits, are briefly reviewed. Prospects for the future of highly-charged ions in traps are also discussed.

  19. An integrated approach for real-time model-based state-of-charge estimation of lithium-ion batteries

    NASA Astrophysics Data System (ADS)

    Zhang, Cheng; Li, Kang; Pei, Lei; Zhu, Chunbo

    2015-06-01

    Lithium-ion batteries have been widely adopted in electric vehicles (EVs), and accurate state of charge (SOC) estimation is of paramount importance for the EV battery management system. Though a number of methods have been proposed, the SOC estimation for Lithium-ion batteries, such as LiFePo4 battery, however, faces two key challenges: the flat open circuit voltage (OCV) vs SOC relationship for some SOC ranges and the hysteresis effect. To address these problems, an integrated approach for real-time model-based SOC estimation of Lithium-ion batteries is proposed in this paper. Firstly, an auto-regression model is adopted to reproduce the battery terminal behaviour, combined with a non-linear complementary model to capture the hysteresis effect. The model parameters, including linear parameters and non-linear parameters, are optimized off-line using a hybrid optimization method that combines a meta-heuristic method (i.e., the teaching learning based optimization method) and the least square method. Secondly, using the trained model, two real-time model-based SOC estimation methods are presented, one based on the real-time battery OCV regression model achieved through weighted recursive least square method, and the other based on the state estimation using the extended Kalman filter method (EKF). To tackle the problem caused by the flat OCV-vs-SOC segments when the OCV-based SOC estimation method is adopted, a method combining the coulombic counting and the OCV-based method is proposed. Finally, modelling results and SOC estimation results are presented and analysed using the data collected from LiFePo4 battery cell. The results confirmed the effectiveness of the proposed approach, in particular the joint-EKF method.

  20. New Charge Exchange Calculations for Lowly-Charged Ions

    NASA Astrophysics Data System (ADS)

    Stancil, P. C.

    2005-05-01

    The process of charge exchange, which occurs during the collision of an ion with a neutral species, is important in a variety of astrophysical and atmospheric environments. It can have an influence on the ionization and thermal balances of the plasma and may also contribute to the emission spectrum. The charge exchange of multiply-charged ions (q>2) usually proceeds at a fast rate with rate coefficients typically of 10-10 to 10-9 cm3s-1. Therefore, highly-charged ions, which are created in UV or x-ray ionized gas, quickly recombine to smaller charges. However, the rate coefficients for singly- and doubly-charged ions can vary over five orders of magnitude depending on the ion species, the neutral target, and the temperature. In particular, the rate coefficients depend sensitively on the dominant mechanism which may be due to radial, rotational, radiative, or spin-orbit coupling and the corresponding quasi-molecular curves can be very complicated. Measurements of such processes are complicated by metastable contamination and uncertainties in target purity and estimates of empirical values inferred from astrophysical modeling are typically suspect. Therefore, the state of knowledge of lowly-charged electron transfer processes is generally poor, but these reactions can be critical in determining the state of the plasma. If, for example, the rate coefficient for a q=2 ion is very small, the process would result in a bottle-neck in the recombination cascade from higer charges. In an effort to address these problems, quantum-mechanical calculations have been carried out for a number of singly- and doubly-charged ions and benchmarked to measurements when available. I will present a summary of these results which reveal significant differences from values adopted in rate coefficient compilations used by various modeling packages. This work was performed in collaboration with L. B. Zhao, C. Y. Lin, J. P. Gu, H. P. Liebermann, R. J. Buenker, and M. Kimura. Support from NASA

  1. Measurements of charge-state fractions following gas cells in beams of light negative ions

    SciTech Connect

    Grisham, L.R.; Post, D.E.; Johnson, B.M.; Jones, K.W.; Barrette, J.; Kruse, T.H.; Tserruya, I.; Da-Hai, W.

    1981-01-01

    We have measured neutral and charged particle fractions formed by passing beams of Li/sup -/, C/sup -/, O/sup -/, and Si/sup -/ at energies up to 7 MeV through gas cells of N/sub 2/, Ar, or CO/sub 2/. We discuss the implications of these results for the design of neutralizers to yield light atom beams for tokamak heating or current drive.

  2. Charge States of O Ions Injected at Substorm Onset and Estimation of the O+/O6+ Flux Ratio: Geotail/EPIC Observation

    NASA Astrophysics Data System (ADS)

    Fujimori, T.; Nose, M.; Keika, K.; Christon, S. P.

    2004-12-01

    Oxygen ions in the Earth's magnetosphere are supplied from two sources, that is, the ionosphere and the solar wind. The charge states of oxygen from the ionosphere are generally low such as O+, while those from the solar wind are highly charged (mainly O6+). Investigating the amount of oxygen with each charge state in various energy ranges in the magnetosphere and its source region gives us information how it is energized during travel from its origin to the magnetosphere. This would be a clue to know the acceleration mechanisms of oxygen in the magnetosphere. However, only a few satellites carried instruments which can measure the ions' charge states. Furthermore, they are not sensitive enough in the high energy range (more than 100 keV) because the number of ions in this energy range is small. It is also difficult to analyze a phenomenon in a short time scale such as ion injection from the near-Earth tail into the inner magnetosphere at substorm onset. In this study, we estimate the charge state of injected oxygen in various energy ranges by using the method of Sibeck et al. [Geophys. Res. Lett., 15, 1287 - 1290, 1988] with the flux data from the EPIC/ICS instrument on Geotail; it can measure mass of ion in the energy range of 50 keV - 3 MeV but not charge state. This method uses the energy dispersion of flux enhancements of injected ions, which is dependent on the charge state of them. This dispersion is responsible for the drift velocity of ions in the inner magnetosphere depending on their energy and charge state. We analyzed the ICS data statistically to estimate charge state of oxygen ions for the period of 1996 and October 2000 to September 2001. We also used data from the Geotail/EPIC STICS sensor, which can measure charge state and ion mass, so that the O+/O6+ ratios were given for a few cases where STICS provided enough ion flux to be analyzed for these events. From the analysis we found that (1)In the 50 to 150 keV energy range, the amount of injected O

  3. High charge state, ion-atom collision experiments using accel-decel

    SciTech Connect

    Bernstein, E.M.; Clark, M.W.; Tanis, J.A.; Graham, W.G.

    1987-01-01

    Recent studies of /sub 16/S/sup 13 +/ + He collisions between 2.5 and 200 MeV, which were made using the accel-decel technique with the Brookhaven National Laboratory coupled MP tandem Van de Graaff accelerators, are discussed. Cross sections were measured for single electron-capture and -loss as well as K x rays correlated to electron-capture. Other planned ion-atom collision experiments requiring accel-decel are also presented. 18 refs., 3 figs.

  4. Kalman filter for onboard state of charge estimation and peak power capability analysis of lithium-ion batteries

    NASA Astrophysics Data System (ADS)

    Dong, Guangzhong; Wei, Jingwen; Chen, Zonghai

    2016-10-01

    To evaluate the continuous and instantaneous load capability of a battery, this paper describes a joint estimator for state-of-charge (SOC) and state-of-function (SOF) of lithium-ion batteries (LIB) based on Kalman filter (KF). The SOC is a widely used index for remain useful capacity left in a battery. The SOF represents the peak power capability of the battery. It can be determined by real-time SOC estimation and terminal voltage prediction, which can be derived from impedance parameters. However, the open-circuit-voltage (OCV) of LiFePO4 is highly nonlinear with SOC, which leads to the difficulties in SOC estimation. To solve these problems, this paper proposed an onboard SOC estimation method. Firstly, a simplified linearized equivalent-circuit-model is developed to simulate the dynamic characteristics of a battery, where the OCV is regarded as a linearized function of SOC. Then, the system states are estimated based on the KF. Besides, the factors that influence peak power capability are analyzed according to statistical data. Finally, the performance of the proposed methodology is demonstrated by experiments conducted on a LiFePO4 LIBs under different operating currents and temperatures. Experimental results indicate that the proposed approach is suitable for battery onboard SOC and SOF estimation.

  5. Measurement of Charge Transfer Rate Coefficient Between Ground-State N(2+) Ion and He at Electron-Volt Energies

    NASA Technical Reports Server (NTRS)

    Fang, Z.; Kwong, Victor H. S.

    1997-01-01

    The charge transfer rate coefficient for the reaction N(2+)(2p(sup 2)P(sup 0)) + He yields products is measured by recording the time dependence of the N(2+) ions stored in an ion trap. A cylindrical radio-frequency ion trap was used to store N(2+) ions produced by laser ablation of a solid titanium nitride target. The decay of the ion signals was analyzed by single exponential least-squares fits to the data. The measured rate coefficient is 8.67(0.76) x 10(exp -11)sq cm/s. The N(2+) ions were at a mean energy of 2.7 eV while He gas was at room temperature, corresponding to an equivalent temperature of 3.9 x 10(exp 3) K. The measured value is in good agreement with a recent calculation.

  6. 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.

  7. 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.

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

    DOE PAGES

    Kumar, Deepak; Englesbe, Alexander; Parman, Matthew; ...

    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

  9. Direct correlation of the crystal structure of proteins with the maximum positive and negative charge states of gaseous protein ions produced by electrospray ionization.

    PubMed

    Prakash, Halan; Mazumdar, Shyamalava

    2005-09-01

    Electrospray mass spectrometric studies in native folded forms of several proteins in aqueous solution have been performed in the positive and negative ion modes. The mass spectra of the proteins show peaks corresponding to multiple charge states of the gaseous protein ions. The results have been analyzed using the known crystal structures of these proteins. Crystal structure analysis shows that among the surface exposed residues some are involved in hydrogen-bonding or salt-bridge interactions while some are free. The maximum positive charge state of the gaseous protein ions was directly related to the number of free surface exposed basic groups whereas the maximum negative charge state was related to the number of free surface exposed acidic groups of the proteins. The surface exposed basic groups, which are involved in hydrogen bonding, have lower propensity to contribute to the positive charge of the protein. Similarly, the surface exposed acidic groups involved in salt bridges have lower propensity to contribute to the negative charge of the protein. Analysis of the crystal structure to determine the maximum charge state of protein in the electrospray mass spectrum was also used to interpret the reported mass spectra of several proteins. The results show that both the positive and the negative ion mass spectra of the proteins could be interpreted by simple consideration of the crystal structure of the folded proteins. Moreover, unfolding of the protein was shown to increase the positive charge-state because of the availability of larger number of free basic groups at the surface of the unfolded protein.

  10. Study on the correlation between state of charge and coulombic efficiency for commercial lithium ion batteries

    NASA Astrophysics Data System (ADS)

    Zheng, Yuejiu; Ouyang, Minggao; Lu, Languang; Li, Jianqiu; Zhang, Zhendong; Li, Xiangjun

    2015-09-01

    Coulombic efficiency (CE) is an important parameter for battery cells. Unfortunately, precise measurement of CE is extremely difficult, so CE is seldom focused during cell performance study. Nevertheless, correlation between stage of charge (SOC) and CE has significant impact on battery pack performance, while the influences of different correlations between SOC and CE on battery packs have never been explored as far as we know. We present a novel method which implements two series-connected cells that can determine the correlation between SOC and CE. The experimental result shows that CE is almost invariant with SOC changes for the experimental commercial LiFePO4/C cells. This paper further investigates series-connected cells with three typical correlations between SOC and CE in simulations. The simulation results indicate that cells with negative correlations between CE and SOC are preferred for series-connected battery packs, as they tend to diminish SOC difference and increase the pack capacity which can be considered as a self-balancing mechanism.

  11. Fragmentation of biomolecules using slow highly charged ions

    NASA Astrophysics Data System (ADS)

    Ruehlicke, Christiane; Schneider, Dieter; DuBois, Robert; Balhorn, Rodney

    1997-02-01

    We present first results of biomolecular fragmentation studies with slow highly charged ions (HCI). A thin layer of the tripeptide RVA was deposited on gold targets and irradiated with slow (few 100 keV) ions, e.g. Xe50+ and Xe15+, extracted from the LLNL EBIT (electron beam ion trap). The secondary ions released upon ion impact were mass analyzed via Time-Of-Flight Secondary-Ion-Mass-Spectrometry (TOF-SIMS). The results show a strong dependence of the positive and negative ion yields on the charge state of the incident ion. We also found that incident ions with high charge states cause the ejection of fragments with a wide mass range as well as the intact molecule (345 amu). The underlying mechanisms are not yet understood but electron depletion of the target due to the high incident charge is likely to cause a variety of fragmentation processes.

  12. Injected 1+ ion beam as a diagnostics tool of charge breeder ECR ion source plasmas

    NASA Astrophysics Data System (ADS)

    Tarvainen, O.; Lamy, T.; Angot, J.; Thuillier, T.; Delahaye, P.; Maunoury, L.; Choinski, J.; Standylo, L.; Galatà, A.; Patti, G.; Koivisto, H.

    2015-06-01

    Charge breeder electron cyclotron resonance ion sources (CB-ECRIS) are used as 1+  →n+  charge multiplication devices of post-accelerated radioactive ion beams. The charge breeding process involves thermalization of the injected 1+  ions with the plasma ions in ion-ion collisions, subsequent ionization by electron impact and extraction of the n+  ions. Charge breeding experiments of 85Rb and 133Cs ion beams with the 14.5 GHz PHOENIX CB-ECRIS operating with oxygen gas demonstrate the plasma diagnostics capabilities of the 1+  injection method. Two populations can be distinguished in the m/q-spectrum of the extracted ion beams, the low (1+  and 2+) charge states representing the uncaptured fraction of the incident 1+  ion beam and the high charge states that have been captured in ion-ion collisions and subsequently charge bred through electron impact ionization. Identification of the uncaptured fraction of the 1+  ions allows estimating the lower limit of ion-ion collision frequency of various charge states in the ECRIS plasma. The collision frequencies of highly charged ions (˜107 Hz) are shown to exceed their gyrofrequencies (˜106 Hz) at least by an order of magnitude, which implies that the dynamics of high charge state ions are dictated by magnetically confined electrons and ambipolar diffusion and only low charge state ions can be considered magnetized. Furthermore, it is concluded that the plasma density of the ECRIS charge breeder is most likely on the order of 1011 cm-3 i.e. well below the critical density for 14.5 GHz microwaves.

  13. Charge Detection Mass Spectrometry with Resolved Charge States

    NASA Astrophysics Data System (ADS)

    Contino, Nathan C.; Pierson, Elizabeth E.; Keifer, David Z.; Jarrold, Martin F.

    2013-01-01

    Charge detection mass spectrometry (CDMS) measurements have been performed for cytochrome c and alcohol dehydrogenase (ADH) monomer using a modified cone trap incorporating a cryogenically cooled JFET. Cooling the JFET increases its transconductance and lowers thermal noise, improving the signal to noise (S/N) ratio. Single ions with as few as 9 elementary charges (e) have been detected. According to simulations, the detection efficiency for ions with a charge of 13 e is 75 %, and for charges above 13 e the detection efficiency rapidly approaches 95 %. With the low limit of detection achieved here, adjacent charge states are easily resolved in the m/ z spectrum, so the accuracy and precision of the image charge measurements can be directly evaluated by comparing the measured image charge to the charge deduced from the m/ z spectrum. For ADH monomer ions with 32 to 43 charges, the root mean square deviation of the measured image charge is around 2.2 e. Ions were trapped for over 1500 cycles. The number of cycles detected appears to be limited mainly by collisions with the background gas.[Figure not available: see fulltext.

  14. Equilibrium and non-equilibrium charge-state distributions of 2 MeV/u sulfur ions passing through carbon foils

    NASA Astrophysics Data System (ADS)

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

    2009-08-01

    Both equilibrium and non-equilibrium charge-state distributions for 2.0 MeV/u sulfur ions after passing through carbon foils were studied experimentally. For the equilibrium charge-state distribution, incident ions of S 7+, S 12+, S 14+ and S 16+ were injected into carbon foils 54, 98, 150 and 200 μg/cm 2 in thickness, whereas for the non-equilibrium distributions, new measurements for S 15+ and S 16+ incidences were made through carbon foils of 0.9-10 μg/cm 2 to supplement our previous experiments regarding S 6+-S 14+ incidences [M. Imai, M. Sataka, K. Kawatsura, K. Takahiro, K. Komaki, H. Shibata, H. Sugai, K. Nishio, Nucl. Instr. and Meth. B 230 (2005) 63; M. Imai, M. Sataka, K. Kawatsura, K. Takahiro, K. Komaki, H. Shibata, H. Sugai, K. Nishio, Nucl. Instr. and Meth. B 256 (2007) 11]. Mean charge states for S 6+-S 14+ incidences as functions of the penetration thickness merged at 6.9 μg/cm 2 and changed together until reaching equilibrium at around 100 μg/cm 2, while those for S 15+ and S 16+ incidences took different paths to equilibrium, which was also the case for distribution widths for S 6+-S 14+, S 15+ and S 16+ incidences. An equilibrium mean charge state of 12.68 and distribution width of 1.11 were attained with equilibrium charge distributions between 6+ and 16+.

  15. Multi-time-scale observer design for state-of-charge and state-of-health of a lithium-ion battery

    NASA Astrophysics Data System (ADS)

    Zou, Changfu; Manzie, Chris; Nešić, Dragan; Kallapur, Abhijit G.

    2016-12-01

    The accurate online state estimation for some types of nonlinear singularly perturbed systems is challenging due to extensive computational requirements, ill-conditioned gains and/or convergence issues. This paper proposes a multi-time-scale estimation algorithm for a class of nonlinear systems with coupled fast and slow dynamics. Based on a boundary-layer model and a reduced model, a multi-time-scale estimator is proposed in which the design parameter sets can be tuned in different time-scales. Stability property of the estimation errors is analytically characterized by adopting a deterministic version of extended Kalman filter (EKF). This proposed algorithm is applied to estimator design for the state-of-charge (SOC) and state-of-health (SOH) in a lithium-ion battery using the developed reduced order battery models. Simulation results on a high fidelity lithium-ion battery model demonstrate that the observer is effective in estimating SOC and SOH despite a range of common errors due to model order reductions, linearisation, initialisation and noisy measurement.

  16. Adiabatic calorimetry test of the reaction kinetics and self-heating model for 18650 Li-ion cells in various states of charge

    NASA Astrophysics Data System (ADS)

    Chen, Wei-Chun; Wang, Yih-Wen; Shu, Chi-Min

    2016-06-01

    Use of adiabatic calorimetry to characterise thermal runaway of Li-ion cells is a crucial technique in battery safety testing. Various states of charge (SoC) of Li-ion cells were investigated to ascertain their thermal runaway features using a Vent Sizing Package 2 (VSP2) adiabatic calorimeter. To evaluate the thermal runaway characteristics, the temperature-pressure-time trajectories of commercial cylindrical cells were tested, and it was found that cells at a SoC of greater than 50% were subject to thermal explosion at elevated temperatures. Calorimetry data from various 18650 Li-ion cells with different SoC were used to calculate the thermal explosion energies and chemical kinetics; furthermore, a novel self-heating model based on a pseudo-zero-order reaction that follows the Arrhenius equation was found to be applicable for studying the exothermic reaction of a charged cell.

  17. Extremely supercharged proteins in mass spectrometry: profiling the pH of electrospray generated droplets, narrowing charge state distributions, and increasing ion fragmentation.

    PubMed

    Zenaidee, Muhammad A; Donald, William A

    2015-03-21

    The effects of 12 acids, 4 solvents, and 8 low-volatility additives that increase analyte charging (i.e., superchargers) on the charge state distributions (CSDs) of protein ions in ESI-MS were investigated. We discovered that (i) relatively low concentrations [5% (v/v)] of 1,2-butylene carbonate (and 4-vinyl-1,3-dioxolan-2-one) can be added to ESI solutions to form higher charge states of cytochrome c and myoglobin ions than by using more traditional additives (e.g., propylene carbonate, sulfolane, or m-nitrobenzyl alcohol) under these conditions and (ii) the width of CSDs narrow as the effectiveness of superchargers increase, which concentrates protein ions into fewer detection channels. The use of strong acids (pKa values < 0) results in essentially no protein supercharging, higher adduction of acid molecules, and wider CSDs for many superchargers and proteins, whereas the use of weak acids (pKa > 0) results in significantly higher protein ion charging, less acid adduction, and narrower CSDs, indicating that protein ion supercharging in ESI can be significantly limited by the binding of conjugate base anions of acids that neutralize charge sites and broaden CSDs. The extent of protein charging as a function of acid identity (HA) does not strongly correlate with gas-phase proton transfer data (i.e., gas-phase basicity and proton affinity values for HA and A(-)), solution-phase protein secondary structures (as determined by circular dichroism spectroscopy), and/or acid molecule volatility data. For protein-denaturing solutions, these data were used to infer that the "effective" pH of ESI generated droplets near the moment of ion formation can be ∼0, which is ca. 1 to 3 pH units lower than the pH of the solutions prior to ESI. Electron capture dissociation (ECD) of [ubiquitin, 17H](17+) resulted in the identification of 223 cleavages, 74 of 75 inter-residue sites, and 92% ECD fragmentation efficiency, which correspond to highest of these values that have been

  18. Quantification of Steady-State Ion Transport through Single Conical Nanopores and a Nonuniform Distribution of Surface Charges

    SciTech Connect

    Liu, Juan; Wang, Dengchao; Kvetny, Maksim; Brown, Warren; Liu, Yan; Wang, Gangli

    2013-07-09

    Electrostatic interactions of mobile charges in solution with the fixed surface charges are known to strongly affect stochastic sensing and electrochemical energy conversion processes at nanodevices or devices with nanostructured interfaces. The key parameter to describe this interaction, surface charge density (SCD), is not directly accessible at nanometer scale and often extrapolated from ensemble values. In this report, the steady-state current–voltage (i–V) curves measured using single conical glass nanopores in different electrolyte solutions are fitted by solving Poisson and Nernst–Planck equations through finite element approach. Both high and low conductivity state currents of the rectified i–V curve are quantitatively fitted in simulation at less than 5% error. The overestimation of low conductivity state current using existing models is overcome by the introduction of an exponential SCD distribution inside the conical nanopore. A maximum SCD value at the pore orifice is determined from the fitting of the high conductivity state current, while the distribution length of the exponential SCD gradient is determined by fitting the low conductivity state current. Quantitative fitting of the rectified i–V responses and the efficacy of the proposed model are further validated by the comparison of electrolytes with different types of cations (K+ and Li+). In conclusion, the gradient distribution of surface charges is proposed to be dependent on the local electric field distribution inside the conical nanopore.

  19. Novel Energy Sources -Material Architecture and Charge Transport in Solid State Ionic Materials for Rechargeable Li ion Batteries

    SciTech Connect

    Katiyar, Ram S; Gómez, M; Majumder, S B; Morell, G; Tomar, M S; Smotkin, E; Bhattacharya, P; Ishikawa, Y

    2009-01-19

    Since its introduction in the consumer market at the beginning of 1990s by Sony Corporation ‘Li-ion rechargeable battery’ and ‘LiCoO2 cathode’ is an inseparable couple for highly reliable practical applications. However, a separation is inevitable as Li-ion rechargeable battery industry demand more and more from this well serving cathode. Spinel-type lithium manganate (e.g., LiMn2O4), lithium-based layered oxide materials (e.g., LiNiO2) and lithium-based olivine-type compounds (e.g., LiFePO4) are nowadays being extensively studied for application as alternate cathode materials in Li-ion rechargeable batteries. Primary goal of this project was the advancement of Li-ion rechargeable battery to meet the future demands of the energy sector. Major part of the research emphasized on the investigation of electrodes and solid electrolyte materials for improving the charge transport properties in Li-ion rechargeable batteries. Theoretical computational methods were used to select electrodes and electrolyte material with enhanced structural and physical properties. The effect of nano-particles on enhancing the battery performance was also examined. Satisfactory progress has been made in the bulk form and our efforts on realizing micro-battery based on thin films is close to give dividend and work is progressing well in this direction.

  20. A spectrometer on chemical vapour deposition-diamond basis for the measurement of the charge-state distribution of heavy ions in a laser-generated plasma

    SciTech Connect

    Cayzac, Witold; Frank, Alexander; Schumacher, Dennis; Roth, Markus; Blazevic, Abel; Wamers, Felix; Traeger, Michael; Berdermann, Eleni; Voss, Bernd; Hessling, Thomas

    2013-04-15

    This article reports on the development and the first applications of a new spectrometer which enables the precise and time-resolved measurement of both the energy loss and the charge-state distribution of ion beams with 10 < Z < 30 at energies of 4-8 MeV/u after their interaction with a laser-generated plasma. The spectrometer is based on five 20 Multiplication-Sign 7 mm{sup 2} large and 20 {mu}m thick polycrystalline diamond samples produced via the Chemical Vapour Deposition (CVD) process and was designed with the help of ion-optical simulations. First experiments with the spectrometer were successfully carried out at GSI using {sup 48}Ca ions at an energy of 4.8 MeV/u interacting with a carbon plasma generated by the laser irradiation of a thin foil target. Owing to the high rate capability and the short response time of the spectrometer, pulsed ion beams with 10{sup 3}-10{sup 4} ions per bunch at a bunch frequency of 108 MHz could be detected. The temporal evolution of the five main charge states of the calcium ion beams as well as the corresponding energy loss values could be measured simultaneously. Due to the outstanding properties of diamond as a particle detector, a beam energy resolution ({Delta}E/E) Almost-Equal-To 0.1% could be reached using the presented experimental method, while a precision of 10% in the energy loss and charge-state distribution data was obtained.

  1. Modeling of the charge-state separation at ITEP experimental facility for material science based on a Bernas ion source

    SciTech Connect

    Barminova, H. Y. Saratovskyh, M. S.

    2016-02-15

    The experiment automation system is supposed to be developed for experimental facility for material science at ITEP, based on a Bernas ion source. The program CAMFT is assumed to be involved into the program of the experiment automation. CAMFT is developed to simulate the intense charged particle bunch motion in the external magnetic fields with arbitrary geometry by means of the accurate solution of the particle motion equation. Program allows the consideration of the bunch intensity up to 10{sup 10} ppb. Preliminary calculations are performed at ITEP supercomputer. The results of the simulation of the beam pre-acceleration and following turn in magnetic field are presented for different initial conditions.

  2. Modeling of the charge-state separation at ITEP experimental facility for material science based on a Bernas ion source.

    PubMed

    Barminova, H Y; Saratovskyh, M S

    2016-02-01

    The experiment automation system is supposed to be developed for experimental facility for material science at ITEP, based on a Bernas ion source. The program CAMFT is assumed to be involved into the program of the experiment automation. CAMFT is developed to simulate the intense charged particle bunch motion in the external magnetic fields with arbitrary geometry by means of the accurate solution of the particle motion equation. Program allows the consideration of the bunch intensity up to 10(10) ppb. Preliminary calculations are performed at ITEP supercomputer. The results of the simulation of the beam pre-acceleration and following turn in magnetic field are presented for different initial conditions.

  3. Charge breeding simulations for radioactive ion beam production

    SciTech Connect

    Variale, V.; Raino, A. C.; Clauser, T.

    2012-02-15

    The charge breeding technique is used for radioactive ion beam (RIB) production in order of optimizing the re-acceleration of the radioactive element ions produced by a primary beam in a thick target. Charge breeding is achieved by means of a device capable of increasing the ion charge state from 1+ to a desired value n+. In order to get high intensity RIB, experiments with charge breeding of very high efficiency could be required. To reach this goal, the charge breeding simulation could help to optimize the high charge state production efficiency by finding more proper parameters for the radioactive 1+ ions. In this paper a device based on an electron beam ion source (EBIS) is considered. In order to study that problem, a code already developed for studying the ion selective containment in an EBIS with RF quadrupoles, BRICTEST, has been modified to simulate the ion charge state breeding rate for different 1+ ion injection conditions. Particularly, the charge breeding simulations for an EBIS with a hollow electron beam have been studied.

  4. 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.

  5. Facility produced charge-exchange ions

    NASA Technical Reports Server (NTRS)

    Carruth, M. R., Jr.

    1981-01-01

    These facility produced ions are created by charge-exchange collisions between neutral atoms and energetic thruster beam ions. The result of the electron transfer is an energetic neutral atom and an ion of only thermal energy. There are true charge-exchange ions produced by collisions with neutrals escaping from the ion thruster and being charge-exchange ionized before the neutral intercepts the tank wall. The facility produced charge-exchange ions will not exist in space and therefore, represent a source of error where measurements involving ion thruster plasmas and their density are involved. The quantity of facility produced ions in a test chamber with a 30 cm mercury ion thruster was determined.

  6. Population of n, l States in Electron-Capture Collisions Between Highly Charged, Medium-Velocity Ions and H2

    NASA Astrophysics Data System (ADS)

    Hvelplund, P.; Samsoe, E.; Andersen, L. H.; Haugen, H. K.; Knudsen, H.

    1983-01-01

    The formation of excited states resulting from electron capture by Auq+ ions (q from 12 to 18, v = 2v0) colliding with H2 has been measured by means of optical methods. The capture cross sections into various n, l states are derived from measured emission cross sections by applying a simplified cascade correction. It is found that high l states are preferentially populated and that a large number of n states contributes to the total capture process. The general picture, which emerges from the present study, is in reasonable agreement with theoretical calculations by Olson, by Ryufuku and Watanabe, and by Crothers.

  7. Highly charged Arq+ ions interacting with metals

    NASA Astrophysics Data System (ADS)

    Wang, Jijin; Zhang, Jian; Gu, Jiangang; Luo, Xianwen; Hu, Bitao

    2009-12-01

    Using computer simulation, alternative methods of the interaction of highly charged ions Arq+ with metals (Au, Ag) are used and verified in the present work. Based on the classical over-barrier model, we discussed the promotion loss and peeling off processes. The simulated total potential electron yields agree well with the experiment data in incident energy ranging from 100 eV to 5 keV and all charge states of Arq+ . Based on the TRIM code, we obtain the side-feeding rate as well as the motion and charge transfer of HCI below the surface. Some results, including the array of KLx x-ray satellite lines, the respective contribution of autoionization, and side-feeding to inner shells, and the filling rates and lifetime of inner shells for Ar agree well with experiment or theory.

  8. Production of soft X-ray emitting slow multiply charged ions - Recoil ion spectroscopy

    NASA Technical Reports Server (NTRS)

    Sellin, I. A.; Elston, S. B.; Forester, J. P.; Griffin, P. M.; Pegg, D. J.; Peterson, R. S.; Thoe, R. S.; Vane, C. R.; Wright, J. J.; Groeneveld, K.-O.

    1977-01-01

    S ions with a mean charge state of about 14+ and Cl ions with a mean charge state of 12+ were used to study Ne L-shell vacancy production. The ions caused copious production of NeII-NeVIII excited states with approximately 10 to the minus 18 sq cm cross sections. The induced recoil velocities might have application to a significantly higher resolution spectroscopy than is possible with beam-foil methods.

  9. Charge prediction machine: tool for inferring precursor charge states of electron transfer dissociation tandem mass spectra.

    PubMed

    Carvalho, Paulo C; Cociorva, Daniel; Wong, Catherine C L; Carvalho, Maria da Gloria da C; Barbosa, Valmir C; Yates, John R

    2009-03-01

    Electron transfer dissociation (ETD) can dissociate highly charged ions. Efficient analysis of ions dissociated with ETD requires accurate determination of charge states for calculation of molecular weight. We created an algorithm to assign the charge state of ions often used for ETD. The program, Charge Prediction Machine (CPM), uses Bayesian decision theory to account for different charge reduction processes encountered in ETD and can also handle multiplex spectra. CPM correctly assigned charge states to 98% of the 13,097 MS2 spectra from a combined data set of four experiments. In a comparison between CPM and a competing program, Charger (ThermoFisher), CPM produced half the mistakes.

  10. EBIS charge breeder for radioactive ion beams at ATLAS.

    SciTech Connect

    Ostroumov, P.; Kondrashev, S.; Pardo, R.; Savard, G.; Vondrasek, R.; Alessi, J.; Beebe, E.; Pikin, A.

    2010-07-01

    The construction of the Californium Rare Isotope Breeder Upgrade (CARIBU) for the Argonne National Laboratory ATLAS facility is completed and its commissioning is being performed. In its full capacity, the CARIBU facility will use fission fragments from a 1 Curie (Ci) {sup 252}Cf source. The ions will be thermalized and collected into a low-energy ion beam by a helium gas catcher, mass analyzed by an isobar separator, and charge bred to higher charge states for acceleration in ATLAS. To reach energies E/A 10 MeV/u, one should inject ions with charge-to-mass ratio (q/A) {ge} 1/7 into the ATLAS linac. In the first stage, the existing Electron Cyclotron Resonance (ECR) ion source will be used as a charge breeder. The maximum intensity of radioactive ion beams at the output of the gas catcher will not exceed 10{sup 7} ions per second. A charge breeder based on an Electron Beam Ion Source (EBIS) has significant advantages over the ECR option for ion beam intensities up to about 10{sup 9} ions per second, providing 3-4 times higher efficiency and significantly better purity of highly charged radioactive ion beams for further acceleration. The proposed EBIS project for CARIBU will heavily utilize state-of-the-art EBIS technology recently developed at Brookhaven National Laboratory. This will allow us to reduce both the project cost and timescale, simultaneously insuring reliable technical realization of the cutting-edge technology. Several parameters of the CARIBU EBIS charge breeder (EBIS-CB) will be relaxed with respect to the BNL EBIS in favor of higher reliability and lower cost. Technical performance of the CARIBU charge breeder will not suffer from such a relaxation and will provide high efficiency for a whole range of radioactive ion beams. The goal of this paper is to present the initial design of the EBIS charge breeder for radioactive ion beams at ATLAS.

  11. EBIS charge breeder for radioactive ion beams at ATLAS

    NASA Astrophysics Data System (ADS)

    Ostroumov, P.; Kondrashev, S.; Pardo, R.; Savard, G.; Vondrasek, R.; Alessi, J.; Beebe, E.; Pikin, A.

    2010-07-01

    The construction of the Californium Rare Isotope Breeder Upgrade (CARIBU) for the Argonne National Laboratory ATLAS facility is completed and its commissioning is being performed. In its full capacity, the CARIBU facility will use fission fragments from a 1 Curie (Ci) 252Cf source. The ions will be thermalized and collected into a low-energy ion beam by a helium gas catcher, mass analyzed by an isobar separator, and charge bred to higher charge states for acceleration in ATLAS. To reach energies E/A 10 MeV/u, one should inject ions with charge-to-mass ratio (q/A) >= 1/7 into the ATLAS linac. In the first stage, the existing Electron Cyclotron Resonance (ECR) ion source will be used as a charge breeder. The maximum intensity of radioactive ion beams at the output of the gas catcher will not exceed 107 ions per second. A charge breeder based on an Electron Beam Ion Source (EBIS) has significant advantages over the ECR option for ion beam intensities up to about 109 ions per second, providing 3-4 times higher efficiency and significantly better purity of highly charged radioactive ion beams for further acceleration. The proposed EBIS project for CARIBU will heavily utilize state-of-the-art EBIS technology recently developed at Brookhaven National Laboratory. This will allow us to reduce both the project cost and timescale, simultaneously insuring reliable technical realization of the cutting-edge technology. Several parameters of the CARIBU EBIS charge breeder (EBIS-CB) will be relaxed with respect to the BNL EBIS in favor of higher reliability and lower cost. Technical performance of the CARIBU charge breeder will not suffer from such a relaxation and will provide high efficiency for a whole range of radioactive ion beams. The goal of this paper is to present the initial design of the EBIS charge breeder for radioactive ion beams at ATLAS.

  12. EBIS charge breeder for radioactive ion beams at ATLAS

    SciTech Connect

    Ostroumov, P.; Alessi, J.; Kondrashev, S.; Pardo, R.; Savard, G.; Vondrasek, R.; Beebe, E.; Pikin, A.

    2010-07-20

    The construction of the Californium Rare Isotope Breeder Upgrade (CARIBU) for the Argonne National Laboratory ATLAS facility is completed and its commissioning is being performed. In its full capacity, the CARIBU facility will use fission fragments from a 1 Curie (Ci) {sup 252}Cf source. The ions will be thermalized and collected into a low-energy ion beam by a helium gas catcher, mass analyzed by an isobar separator, and charge bred to higher charge states for acceleration in ATLAS. To reach energies E/A 10 MeV/u, one should inject ions with charge-to-mass ratio (q/A) {ge} 1/7 into the ATLAS linac. In the first stage, the existing Electron Cyclotron Resonance (ECR) ion source will be used as a charge breeder. The maximum intensity of radioactive ion beams at the output of the gas catcher will not exceed 10{sup 7} ions per second. A charge breeder based on an Electron Beam Ion Source (EBIS) has significant advantages over the ECR option for ion beam intensities up to about 10{sup 9} ions per second, providing 3-4 times higher efficiency and significantly better purity of highly charged radioactive ion beams for further acceleration. The proposed EBIS project for CARIBU will heavily utilize state-of-the-art EBIS technology recently developed at Brookhaven National Laboratory. This will allow us to reduce both the project cost and timescale, simultaneously insuring reliable technical realization of the cutting-edge technology. Several parameters of the CARIBU EBIS charge breeder (EBIS-CB) will be relaxed with respect to the BNL EBIS in favor of higher reliability and lower cost. Technical performance of the CARIBU charge breeder will not suffer from such a relaxation and will provide high efficiency for a whole range of radioactive ion beams. The goal of this paper is to present the initial design of the EBIS charge breeder for radioactive ion beams at ATLAS.

  13. The charge state distribution of Be, C, Cl and Al ions at the Lund Pelletron accelerator with the recently modified terminal pumping in use

    NASA Astrophysics Data System (ADS)

    Kiisk, Madis; Hellborg, Ragnar; Persson, Per; Faarinen, Mikko; Skog, Göran; Stenström, Kristina

    2004-04-01

    Some years ago terminal pumping for the gas stripper system at the 3 MV Lund Tandem Pelletron accelerator was installed and charge state distribution measurements using the new installation were reported. Since then, new modifications of the mechanical design of the stripper system have been made. The results of pressure profile measurements as well as the results of charge state distribution measurements in a N 2 and Ar gas stripper at different, new geometrical modifications of the stripper system using C, Be, Al and Cl ion beams are reported. A comparison between pressure profiles obtained for different geometries shows a clear improvement of the vacuum conditions outside the stripper housing for the smallest conductance pipes between the stripper system and the accelerator tubes. These improvements are also well reflected in the charge state distribution measurements, as a higher mean charge state is obtained under the same vacuum conditions in the accelerator tubes for the improved stripper system in comparison with the former mechanical design.

  14. The Solar Connection of Enhanced Heavy Ion Charge States in the Interplanetary Medium: Implications for the Flux-Rope Structure of CMEs

    NASA Technical Reports Server (NTRS)

    Gopalswamy, N.; Makela, P.; Akiyama, S.; Xie, H.; Yashiro, S.; Reinard, A. A.

    2013-01-01

    We investigated a set of 54 interplanetary coronal mass ejection (ICME) events whose solar sources are very close to the disk center (within +/- 15deg from the central meridian). The ICMEs consisted of 23 magnetic-cloud (MC) events and 31 non-MC events. Our analyses suggest that the MC and non-MC ICMEs have more or less the same eruption characteristics at the Sun in terms of soft X-ray flares and CMEs. Both types have significant enhancements in ion charge states, although the non-MC structures have slightly lower levels of enhancement. The overall duration of charge-state enhancement is also considerably smaller than that in MCs as derived from solar wind plasma and magnetic signatures. We find very good correlation between the Fe and O charge-state measurements and the flare properties such as soft X-ray flare intensity and flare temperature for both MCs and non-MCs. These observations suggest that both MC and non-MC ICMEs are likely to have a flux-rope structure and the unfavorable observational geometry may be responsible for the appearance of non-MC structures at 1 AU. We do not find any evidence for an active region expansion resulting in ICMEs lacking a flux-rope structure because the mechanism of producing high charge states and the flux-rope structure at the Sun is the same for MC and non-MC events.

  15. The Solar Connection of Enhanced Heavy Ion Charge States in the Interplanetary Medium: Implications for the Flux-Rope Structure of CMEs

    NASA Technical Reports Server (NTRS)

    Gopalswamy, N.; Makela, P.; Akiyama, S.; Xie, H.; Yashiro, S.; Reinard, A. A.

    2013-01-01

    We investigated a set of 54 interplanetary coronal mass ejection (ICME) events whose solar sources are very close to the disk center (within +/- 15deg from the central meridian). The ICMEs consisted of 23 magnetic-cloud (MC) events and 31 non-MC events. Our analyses suggest that the MC and non-MC ICMEs have more or less the same eruption characteristics at the Sun in terms of soft X-ray flares and CMEs. Both types have significant enhancements in ion charge states, although the non-MC structures have slightly lower levels of enhancement. The overall duration of charge-state enhancement is also considerably smaller than that in MCs as derived from solar wind plasma and magnetic signatures. We find very good correlation between the Fe and O charge-state measurements and the flare properties such as soft X-ray flare intensity and flare temperature for both MCs and non-MCs. These observations suggest that both MC and non-MC ICMEs are likely to have a flux-rope structure and the unfavorable observational geometry may be responsible for the appearance of non-MC structures at 1 AU. We do not find any evidence for an active region expansion resulting in ICMEs lacking a flux-rope structure because the mechanism of producing high charge states and the flux-rope structure at the Sun is the same for MC and non-MC events.

  16. A study of 40 Ah lithium ion batteries at zero percent state of charge as a function of temperature

    NASA Astrophysics Data System (ADS)

    Attidekou, Pierrot S.; Lambert, Simon; Armstrong, Matthew; Widmer, James; Scott, Keith; Christensen, Paul A.

    2014-12-01

    A theoretical equivalent circuit model of two 40 Ah commercial batteries supplied by Saft was formulated to interpret electrochemical impedance spectra as a function of temperature at zero state-of-charge. The batteries were chosen to represent viable and non-viable products from the Saft production line. This paper is the first contribution from a project in Newcastle to develop a rapid, non-destructive analytical method for quality control on the battery production line. Using the model, it proved straightforward to discriminate between viable and non-viable batteries based on the temperature dependence of the electrochemical reaction kinetics at the electrodes, the average diffusion coefficients and the charge transfer resistances. Furthermore, as well as marked differences, for example, between the time constants, activation energies, polarisation resistances of the viable and non-viable batteries, the individual contributions of the anodes and cathodes in the batteries were de-convoluted and interpreted through the model framework.

  17. Precision mass measurements of highly charged ions

    NASA Astrophysics Data System (ADS)

    Kwiatkowski, A. A.; Bale, J. C.; Brunner, T.; Chaudhuri, A.; Chowdhury, U.; Ettenauer, S.; Frekers, D.; Gallant, A. T.; Grossheim, A.; Lennarz, A.; Mane, E.; MacDonald, T. D.; Schultz, B. E.; Simon, M. C.; Simon, V. V.; Dilling, J.

    2012-10-01

    The reputation of Penning trap mass spectrometry for accuracy and precision was established with singly charged ions (SCI); however, the achievable precision and resolving power can be extended by using highly charged ions (HCI). The TITAN facility has demonstrated these enhancements for long-lived (T1/2>=50 ms) isobars and low-lying isomers, including ^71Ge^21+, ^74Rb^8+, ^78Rb^8+, and ^98Rb^15+. The Q-value of ^71Ge enters into the neutrino cross section, and the use of HCI reduced the resolving power required to distinguish the isobars from 3 x 10^5 to 20. The precision achieved in the measurement of ^74Rb^8+, a superallowed β-emitter and candidate to test the CVC hypothesis, rivaled earlier measurements with SCI in a fraction of the time. The 111.19(22) keV isomeric state in ^78Rb was resolved from the ground state. Mass measurements of neutron-rich Rb and Sr isotopes near A = 100 aid in determining the r-process pathway. Advanced ion manipulation techniques and recent results will be presented.

  18. Secondary ions from condensed gas solids by singly and multiply charged ion impacts

    NASA Astrophysics Data System (ADS)

    Tachibana, T.; Fukai, K.; Naemura, I.; Koizumi, T.; Hirayama, T.

    2009-11-01

    Ion desorption from a condensed gas solid Ne impacted by singly- and multiply-charged Arq+ ions (q = 1-7) has been investigated. Various secondary ions such as cluster ions, Ne+n (n = 2-20) as well as atomic ions are observed. Mass spectral patterns, thickness dependence of the yields, and kinetic energy distributions of the desorbed Ne+n (n = 1,2) depend strongly on the projectile charge state. These results indicate that the dissipation of the projectile potential energy on the surface leads to the desorption of the monomer and small cluster ions by a Coulomb repulsion between adjacent target ions.

  19. Surface nanostructures by single highly charged ions.

    PubMed

    Facsko, S; Heller, R; El-Said, A S; Meissl, W; Aumayr, F

    2009-06-03

    It has recently been demonstrated that the impact of individual, slow but highly charged ions on various surfaces can induce surface modifications with nanometer dimensions. Generally, the size of these surface modifications (blisters, hillocks, craters or pits) increases dramatically with the potential energy of the highly charged ion, while the kinetic energy of the projectile ions seems to be of little importance. This paper presents the currently available experimental evidence and theoretical models and discusses the circumstances and conditions under which nanosized features on different surfaces due to the impact of slow highly charged ions can be produced.

  20. In-Trap Spectroscopy of Charge-Bred Radioactive Ions

    NASA Astrophysics Data System (ADS)

    Lennarz, A.; Grossheim, A.; Leach, K. G.; Alanssari, M.; Brunner, T.; Chaudhuri, A.; Chowdhury, U.; Crespo López-Urrutia, J. R.; Gallant, A. T.; Holl, M.; Kwiatkowski, A. A.; Lassen, J.; Macdonald, T. D.; Schultz, B. E.; Seeraji, S.; Simon, M. C.; Andreoiu, C.; Dilling, J.; Frekers, D.

    2014-08-01

    In this Letter, we introduce the concept of in-trap nuclear decay spectroscopy of highly charged radioactive ions and describe its successful application as a novel spectroscopic tool. This is demonstrated by a measurement of the decay properties of radioactive mass A=124 ions (here, In124 and Cs124) in the electron-beam ion trap of the TITAN facility at TRIUMF. By subjecting the trapped ions to an intense electron beam, the ions are charge bred to high charge states (i.e., equivalent to the removal of N-shell electrons), and an increase of storage times to the level of minutes without significant ion losses is achieved. The present technique opens the venue for precision spectroscopy of low branching ratios and is being developed in the context of measuring electron-capture branching ratios needed for determining the nuclear ground-state properties of the intermediate odd-odd nuclei in double-beta (ββ) decay.

  1. Holographic heavy ion collisions with baryon charge

    SciTech Connect

    Casalderrey-Solana, Jorge; Mateos, David; van der Schee, Wilke; Triana, Miquel

    2016-09-19

    We numerically simulate collisions of charged shockwaves in Einstein-Maxwell theory in anti-de Sitter space as a toy model of heavy ion collisions with non-zero baryon charge. The stress tensor and the baryon current become well described by charged hydrodynamics at roughly the same time. The effect of the charge density on generic observables is typically no larger than 15%. Finally, we find significant stopping of the baryon charge and compare our results with those in heavy ion collision experiments.

  2. Holographic heavy ion collisions with baryon charge

    NASA Astrophysics Data System (ADS)

    Casalderrey-Solana, Jorge; Mateos, David; van der Schee, Wilke; Triana, Miquel

    2016-09-01

    We numerically simulate collisions of charged shockwaves in Einstein-Maxwell theory in anti-de Sitter space as a toy model of heavy ion collisions with non-zero baryon charge. The stress tensor and the baryon current become well described by charged hydrodynamics at roughly the same time. The effect of the charge density on generic observables is typically no larger than 15%. We find significant stopping of the baryon charge and compare our results with those in heavy ion collision experiments.

  3. Magnetic hyperfine structure of the ground-state doublet in highly charged ions 89+,87+229Th and the Bohr-Weisskopf effect

    NASA Astrophysics Data System (ADS)

    Tkalya, E. V.; Nikolaev, A. V.

    2016-07-01

    Background: The search for new opportunities to investigate the low-energy level in the 229Th nucleus, which is nowadays intensively studied experimentally, has motivated us to theoretical studies of the magnetic hyperfine (MHF) structure of the 5 /2+ (0.0 eV) ground state and the low-lying 3 /2+ (7.8 eV) isomeric state in highly charged 89+229Th and 87+229Th ions. Purpose: The aim is to calculate, with the maximal precision presently achievable, the energy of levels of the hyperfine structure of the 229Th ground-state doublet in highly charged ions and the probability of radiative transitions between these levels. Methods: The distribution of the nuclear magnetization (the Bohr-Weisskopf effect) is accounted for in the framework of the collective nuclear model with Nilsson model wave functions for the unpaired neutron. Numerical calculations using precise atomic density functional theory methods, with full account of the electron self-consistent field, have been performed for the electron structure inside and outside the nuclear region. Results: The deviations of the MHF structure for the ground and isomeric states from their values in a model of a pointlike nuclear magnetic dipole are calculated. The influence of the mixing of the states with the same quantum number F on the energy of sublevels is studied. Taking into account the mixing of states, the probabilities of the transitions between the components of the MHF structure are calculated. Conclusions: Our findings are relevant for experiments with highly ionized 229Th ions in a storage ring at an accelerator facility.

  4. The charge spectrum of positive ions in a hydrogen aurora

    NASA Technical Reports Server (NTRS)

    Lynch, J.; Pulliam, D.; Leach, R.; Scherb, F.

    1976-01-01

    An auroral ion charge spectrometer was flown into a hydrogen aurora on a Javelin sounding rocket launched from Churchill, Manitoba. The instrument contained an electrostatic analyzer which selected particles with incident energy per unit charge up to 20 keV/charge and an 80-kV power supply which accelerated these ions onto an array of solid state detectors. Ions tentatively identified as H(+), He(+2), and O(+) were detected from 225 to 820 km in altitude. The experiment did not discriminate between H(+) and He(+), or between O(+), N(+), and C(+). Upper limits of highly charged heavy ion abundances have been set at 20% of the He(+2) and 0.15% of the H(+). It is concluded that both terrestrial and solar wind sources play significant roles in auroral ion precipitation.

  5. The charge spectrum of positive ions in a hydrogen aurora

    NASA Technical Reports Server (NTRS)

    Lynch, J.; Pulliam, D.; Leach, R.; Scherb, F.

    1976-01-01

    An auroral ion charge spectrometer was flown into a hydrogen aurora on a Javelin sounding rocket launched from Churchill, Manitoba. The instrument contained an electrostatic analyzer which selected particles with incident energy per unit charge up to 20 keV/charge and an 80-kV power supply which accelerated these ions onto an array of solid state detectors. Ions tentatively identified as H(+), He(+2), and O(+) were detected from 225 to 820 km in altitude. The experiment did not discriminate between H(+) and He(+), or between O(+), N(+), and C(+). Upper limits of highly charged heavy ion abundances have been set at 20% of the He(+2) and 0.15% of the H(+). It is concluded that both terrestrial and solar wind sources play significant roles in auroral ion precipitation.

  6. The 4-pyridylmethyl ester as a protecting group for glutamic and aspartic acids: 'flipping' peptide charge states for characterization by positive ion mode ESI-MS.

    PubMed

    Garapati, Sriramya; Burns, Colin S

    2014-03-01

    Use of the 4-pyridylmethyl ester group for side-chain protection of glutamic acid residues in solid-phase peptide synthesis enables switching of the charge state of a peptide from negative to positive, thus making detection by positive ion mode ESI-MS possible. The pyridylmethyl ester moiety is readily removed from peptides in high yield by hydrogenation. Combining the 4-pyridylmethyl ester protecting group with benzyl ester protection reduces the number of the former needed to produce a net positive charge and allows for purification by RP HPLC. This protecting group is useful in the synthesis of highly acidic peptide sequences, which are often beset by problems with purification by standard RP HPLC and characterization by ESI-MS. Copyright © 2014 European Peptide Society and John Wiley & Sons, Ltd.

  7. Laserspray ionization imaging of multiply charged ions using a commercial vacuum MALDI ion source.

    PubMed

    Inutan, Ellen D; Wager-Miller, James; Mackie, Ken; Trimpin, Sarah

    2012-11-06

    This is the first report of imaging mass spectrometry (MS) from multiply charged ions at vacuum. Laserspray ionization (LSI) was recently extended to applications at vacuum producing electrospray ionization-like multiply charged ions directly from surfaces using a commercial intermediate pressure matrix-assisted laser desorption/ionization ion mobility spectrometry (IMS) MS instrument. Here, we developed a strategy to image multiply charged peptide ions. This is achieved by the use of 2-nitrophloroglucinol as matrix for spray deposition onto the tissue section and implementation of "soft" acquisition conditions including lower laser power and ion accelerating voltages similar to electrospray ionization-like conditions. Sufficient ion abundance is generated by the vacuum LSI method to employ IMS separation in imaging multiply charged ions obtained on a commercial mass spectrometer ion source without physical instrument modifications using the laser in the commercially available reflection geometry alignment. IMS gas-phase separation reduces the complexity of the ion signal from the tissue, especially for multiply charged relative to abundant singly charged ions from tissue lipids. We show examples of LSI tissue imaging from charge state +2 of three endogenous peptides consisting of between 1 and 16 amino acid residues from the acetylated N-terminal end of myelin basic protein: mass-to-charge (m/z) 795.81 (+2) molecular weight (MW) 1589.6, m/z 831.35 (+2) MW 1660.7, and m/z 917.40 (+2) MW 1832.8.

  8. Spacecraft charging during ion beam emissions in sunlight

    NASA Technical Reports Server (NTRS)

    Lai, S. T.; Mcneil, W. J.; Aggson, T. L.

    1990-01-01

    During ion beam emissions from the SCATHA satellite, the potential of the negatively charged satellite body shows a sinusoidal oscillation frequency of once-per-spin of the satellite. The minimum occurs when the ion beam is sunward. The processes that may be responsible for the voltage modulation are considered. Neutralization of ion beam space charge by photoelectrons is examined. The photoelectrons are accelerated by the negative potential of the satellite. Effects of electron impact ionization, excitation of metastable states, and photoionization of xenon neutral atoms in the ion beam are studied in detail. Critical ionization velocity interaction is unlikely under the condition considered.

  9. The spectral lines of highly charged gold ions

    NASA Astrophysics Data System (ADS)

    Hu, Feng; Yang, Jiamin; Zhang, Jiyan; Jiang, Gang

    2015-02-01

    Extreme ultraviolet spectra of highly charged gold were produced with an electron beam ion trap at the University of Electro-Communications, Tokyo. The X-ray spectra (3240-3360 eV) of Au with well-defined maximum charge states ranging from Cu- to Se-like ions were recorded. Guided by configuration interaction calculations, the strongest 3d-5f transitions have been well defined.

  10. Estimation of state-of-charge of Li-ion batteries in EV using the genetic particle filter

    NASA Astrophysics Data System (ADS)

    Bi, Jun; Gao, Hang; Wang, Yongxing; Zhao, Xiaomei

    2017-08-01

    Estimating the state of charge (SOC) of electric vehicle (EV) batteries accurately and timely is of great significance to the safe trip of pure EV. Based on the nonlinear properties of the battery, and the standard particle filter (PF) has certain adaptability for this feature, so it can be used to accurately estimate the SOC of the batteries. However, the standard PF has particle degeneracy phenomenon, which will make the accuracy of prediction lower. Therefore, in this paper, the genetic algorithm is applied to the standard PF, and the estimation of SOC is optimized, which makes the improved filter algorithm more accurate. Based on the measured data of Beijing pure electric sanitation vehicle, an experiment is defined to verify the algorithm. The experimental results show that the genetic particle filter (GPF) can increase the diversity of particles and has better prediction accuracy and timeliness than the PF.

  11. ION SOURCE WITH SPACE CHARGE NEUTRALIZATION

    DOEpatents

    Flowers, J.W.; Luce, J.S.; Stirling, W.L.

    1963-01-22

    This patent relates to a space charge neutralized ion source in which a refluxing gas-fed arc discharge is provided between a cathode and a gas-fed anode to provide ions. An electron gun directs a controlled, monoenergetic electron beam through the discharge. A space charge neutralization is effected in the ion source and accelerating gap by oscillating low energy electrons, and a space charge neutralization of the source exit beam is effected by the monoenergetic electron beam beyond the source exit end. The neutralized beam may be accelerated to any desired energy at densities well above the limitation imposed by Langmuir-Child' s law. (AEC)

  12. A novel method for state of charge estimation of lithium-ion batteries using a nonlinear observer

    NASA Astrophysics Data System (ADS)

    Xia, Bizhong; Chen, Chaoren; Tian, Yong; Sun, Wei; Xu, Zhihui; Zheng, Weiwei

    2014-12-01

    The state of charge (SOC) is important for the safety and reliability of battery operation since it indicates the remaining capacity of a battery. However, as the internal state of each cell cannot be directly measured, the value of the SOC has to be estimated. In this paper, a novel method for SOC estimation in electric vehicles (EVs) using a nonlinear observer (NLO) is presented. One advantage of this method is that it does not need complicated matrix operations, so the computation cost can be reduced. As a key step in design of the nonlinear observer, the state-space equations based on the equivalent circuit model are derived. The Lyapunov stability theory is employed to prove the convergence of the nonlinear observer. Four experiments are carried out to evaluate the performance of the presented method. The results show that the SOC estimation error converges to 3% within 130 s while the initial SOC error reaches 20%, and does not exceed 4.5% while the measurement suffers both 2.5% voltage noise and 5% current noise. Besides, the presented method has advantages over the extended Kalman filter (EKF) and sliding mode observer (SMO) algorithms in terms of computation cost, estimation accuracy and convergence rate.

  13. 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.

  14. Local charge exchange of He+ ions at Aluminum surfaces

    NASA Astrophysics Data System (ADS)

    Riccardi, P.; Sindona, A.; Dukes, C. A.

    2017-04-01

    We report on experiments designed to observe the correlation between the autoionization of doubly excited helium atoms and the Auger decay of 2p vacancies in Al. The autoionizing states are formed when incident He+* and He++ are neutralized by resonant electron capture at the surface. 2p excitation in Al occurs in dielectronic charge transfer during the close encounter of an excited helium ion and an Al atom. These results clarify the mechanism for Al-2p excitation in the case of singly charged ground state He+(1s) ion impact, where the dielectronic transition occurs after promotion of the 1s electron of incoming ions.

  15. Laser ion source for low charge heavy ion beams

    SciTech Connect

    Okamura,M.; Pikin, A.; Zajic, V.; Kanesue, T.; Tamura, J.

    2008-08-03

    For heavy ion inertial fusion application, a combination of a laser ion source and direct plasma injection scheme into an RFQ is proposed. The combination might provide more than 100 mA of singly charged heavy ion beam from a single laser shot. A planned feasibility test with moderate current is also discussed.

  16. Photoionizing Trapped Highly Charged Ions with Synchrotron Radiation

    SciTech Connect

    Crespo, J R; Simon, M; Beilmann, C; Rudolph, J; Steinbruegge, R; Eberle, S; Schwarz, M; Baumann, T; Schmitt, B; Brunner, F; Ginzel, R; Klawitter, R; Kubicek, K; Epp, S; Mokler, P; Maeckel, V; Ullrich, J; Brown, G V; Graf, A; Leutenegger, M; Beiersdorfer, P; Behar, E; Follath, R; Reichardt, G; Schwarzkopf, O

    2011-09-12

    Photoabsorption by highly charged ions plays an essential role in astrophysical plasmas. Diagnostics of photoionized plasmas surrounding binary systems rely heavily on precise identification of absorption lines and on the knowledge of their cross sections and widths. Novel experiments using an electron beam ion trap, FLASH EBIT, in combination with monochromatic synchrotron radiation allow us to investigate ions in charge states hitherto out of reach. Trapped ions can be prepared in any charge state at target densities sufficient to measure absorption cross sections below 0.1 Mb. The results benchmark state-of-the-art predictions of the transitions wavelengths, widths, and absolute cross sections. Recent high resolution results on Fe{sup 14+}, Fe{sup 15+}, and Ar{sup 12+} at photon energies up to 1 keV are presented.

  17. The retinal chromophore/chloride ion pair: structure of the photoisomerization path and interplay of charge transfer and covalent states.

    PubMed

    Cembran, Alessandro; Bernardi, Fernando; Olivucci, Massimo; Garavelli, Marco

    2005-05-03

    Ab initio multi-reference second-order perturbation theory computations are used to explore the photochemical behavior of two ion pairs constituted by a chloride counterion interacting with either a rhodopsin or bacteriorhodopsin chromophore model (i.e., the 4-cis-gamma-methylnona-2,4,6,8-tetraeniminium and all-trans-nona-2,4,6,8-tetraeniminium cations, respectively). Significant counterion effects on the structure of the photoisomerization paths are unveiled by comparison with the paths of the same chromophores in vacuo. Indeed, we demonstrate that the counterion (i) modulates the relative stability of the S0, S1, and S2 energy surfaces leading to an S1 isomerization energy profile where the S1 and S2 states are substantially degenerate; (ii) leads to the emergence of significant S1 energy barriers along all of the isomerization paths except the one mimicking the 11-cis --> all-trans isomerization of the rhodopsin chromophore model; and (iii) changes the nature of the S1 --> S0 decay funnel that becomes a stable excited state minimum when the isomerizing double bond is located at the center of the chromophore moiety. We show that these (apparently very different) counterion effects can be rationalized on the basis of a simple qualitative electrostatic model, which also provides a crude basis for understanding the behavior of retinal protonated Schiff bases in solution.

  18. The retinal chromophore/chloride ion pair: Structure of the photoisomerization path and interplay of charge transfer and covalent states

    PubMed Central

    Cembran, Alessandro; Bernardi, Fernando; Olivucci, Massimo; Garavelli, Marco

    2005-01-01

    Ab initio multireference second-order perturbation theory computations are used to explore the photochemical behavior of two ion pairs constituted by a chloride counterion interacting with either a rhodopsin or bacteriorhodopsin chromophore model (i.e., the 4-cis-γ-methylnona-2,4,6,8-tetraeniminium and all-trans-nona-2,4,6,8-tetraeniminium cations, respectively). Significant counterion effects on the structure of the photoisomerization paths are unveiled by comparison with the paths of the same chromophores in vacuo. Indeed, we demonstrate that the counterion (i) modulates the relative stability of the S0, S1, and S2 energy surfaces leading to an S1 isomerization energy profile where the S1 and S2 states are substantially degenerate; (ii) leads to the emergence of significant S1 energy barriers along all of the isomerization paths except the one mimicking the 11-cis → all-trans isomerization of the rhodopsin chromophore model; and (iii) changes the nature of the S1 → S0 decay funnel that becomes a stable excited state minimum when the isomerizing double bond is located at the center of the chromophore moiety. We show that these (apparently very different) counterion effects can be rationalized on the basis of a simple qualitative electrostatic model, which also provides a crude basis for understanding the behavior of retinal protonated Schiff bases in solution. PMID:15855270

  19. Estimation method of state-of-charge for lithium-ion battery used in hybrid electric vehicles based on variable structure extended kalman filter

    NASA Astrophysics Data System (ADS)

    Sun, Yong; Ma, Zilin; Tang, Gongyou; Chen, Zheng; Zhang, Nong

    2016-07-01

    Since the main power source of hybrid electric vehicle(HEV) is supplied by the power battery, the predicted performance of power battery, especially the state-of-charge(SOC) estimation has attracted great attention in the area of HEV. However, the value of SOC estimation could not be greatly precise so that the running performance of HEV is greatly affected. A variable structure extended kalman filter(VSEKF)-based estimation method, which could be used to analyze the SOC of lithium-ion battery in the fixed driving condition, is presented. First, the general lower-order battery equivalent circuit model(GLM), which includes column accumulation model, open circuit voltage model and the SOC output model, is established, and the off-line and online model parameters are calculated with hybrid pulse power characteristics(HPPC) test data. Next, a VSEKF estimation method of SOC, which integrates the ampere-hour(Ah) integration method and the extended Kalman filter(EKF) method, is executed with different adaptive weighting coefficients, which are determined according to the different values of open-circuit voltage obtained in the corresponding charging or discharging processes. According to the experimental analysis, the faster convergence speed and more accurate simulating results could be obtained using the VSEKF method in the running performance of HEV. The error rate of SOC estimation with the VSEKF method is focused in the range of 5% to 10% comparing with the range of 20% to 30% using the EKF method and the Ah integration method. In Summary, the accuracy of the SOC estimation in the lithium-ion battery cell and the pack of lithium-ion battery system, which is obtained utilizing the VSEKF method has been significantly improved comparing with the Ah integration method and the EKF method. The VSEKF method utilizing in the SOC estimation in the lithium-ion pack of HEV can be widely used in practical driving conditions.

  20. Charge exchange and energy loss of slow highly charged ions in 1 nm thick carbon nanomembranes.

    PubMed

    Wilhelm, Richard A; Gruber, Elisabeth; Ritter, Robert; Heller, René; Facsko, Stefan; Aumayr, Friedrich

    2014-04-18

    Experimental charge exchange and energy loss data for the transmission of slow highly charged Xe ions through ultrathin polymeric carbon membranes are presented. Surprisingly, two distinct exit charge state distributions accompanied by charge exchange dependent energy losses are observed. The energy loss for ions exhibiting large charge loss shows a quadratic dependency on the incident charge state indicating that equilibrium stopping force values do not apply in this case. Additional angle resolved transmission measurements point on a significant contribution of elastic energy loss. The observations show that regimes of different impact parameters can be separated and thus a particle's energy deposition in an ultrathin solid target may not be described in terms of an averaged energy loss per unit length.

  1. Spectroscopy with trapped highly charged ions

    SciTech Connect

    Beiersdorfer, P

    2008-01-23

    We give an overview of atomic spectroscopy performed on electron beam ion traps at various locations throughout the world. Spectroscopy at these facilities contributes to various areas of science and engineering, including but not limited to basic atomic physics, astrophysics, extreme ultraviolet lithography, and the development of density and temperature diagnostics of fusion plasmas. These contributions are accomplished by generating, for example, spectral surveys, making precise radiative lifetime measurements, accounting for radiative power emitted in a given wavelength band, illucidating isotopic effects, and testing collisional-radiative models. While spectroscopy with electron beam ion traps had originally focused on the x-ray emission from highly charged ions interacting with the electron beam, the operating modes of such devices have expanded to study radiation in almost all wavelength bands from the visible to the hard x-ray region; and at several facilities the ions can be studied even in the absence of an electron beam. Photon emission after charge exchange or laser excitation has been observed, and the work is no longer restricted to highly charged ions. Much of the experimental capabilities are unique to electron beam ion traps, and the work performed with these devices cannot be undertaken elsewhere. However, in other areas the work on electron beam ion traps rivals the spectroscopy performed with conventional ion traps or heavy-ion storage rings. The examples we present highlight many of the capabilities of the existing electron beam ion traps and their contributions to physics.

  2. Current density and state of charge inhomogeneities in Li-ion battery cells with LiFePO4 as cathode material due to temperature gradients

    NASA Astrophysics Data System (ADS)

    Fleckenstein, Matthias; Bohlen, Oliver; Roscher, Michael A.; Bäker, Bernard

    2011-05-01

    Current density distributions and local state of charge (SoC) differences that are caused by temperature gradients inside actively cooled Li-ion battery cells are discussed and quantified. As an example, a cylindrical Li-ion cell with LiFePO4 as cathode material (LiFePO4-cell) is analyzed in detail both experimentally and by means of spatial electro-thermal co-simulations. The reason for current density inhomogeneities is found to be the local electrochemical impedance varying with temperature in different regions of the jelly roll. For the investigated cell, high power cycling and the resulting temperature gradient additionally cause SoC-gradients inside the jelly roll. The local SoCs inside one cell diverge firstly because of asymmetric current density distributions during charge and discharge inside the cell and secondly because of the temperature dependence of the local open circuit potential. Even after long relaxation periods, the SoC distribution in cycled LiFePO4-cells remains inhomogeneous across the jelly roll as a result of hysteresis in the open circuit voltage. The occurring thermal electrical inhomogeneities are expected to influence local aging differences and thus, global cell aging. Additionally the occurrence of inhomogeneous current flow and SoC-development inside non-uniformly cooled battery packs of parallel connected LiFePO4-cells is measured and discussed.

  3. Charge transfer between fullerenes and highly charged noble gas ions

    NASA Astrophysics Data System (ADS)

    Narits, A. A.

    2008-07-01

    A semiclassical model for the description of charge-exchange processes in collisions between fullerenes and multiply charged ions is developed. It is based on the decay model combined with the impact-parameter representation for the heavy particles' relative motion. The charge-transfer process in our model is treated as a transition of the active electron over and under the quasistatic potential barrier formed by the electric fields of the target and projectile. Due to the high electron delocalization on the surface of fullerene we represent it as a perfectly conducting hard sphere, whose radius is determined by the dipole polarizability of C60. The energies of the active electrons are assumed to be equal to the corresponding ionization potentials including the Stark-shift effect. We have developed an efficient technique for the evaluation of the electron transmission coefficient through the asymmetric potential barrier. It is shown that our model provides a good agreement with the available experimental data on single-electron charge-exchange processes. Moreover, it allows us to get an adequate description of multi-electron transfer processes. The first theoretical results on charge exchange between the fullerene ions and highly charged ions have been obtained.

  4. Secondary ion coincidence in highly charged ion based secondary ion mass spectroscopy for process characterization

    SciTech Connect

    Hamza, A.V.; Schenkel, T.; Barnes, A.V.; Schneider, D.H.

    1999-01-01

    Coincidence counting in highly charged ion based secondary ion mass spectroscopy has been applied to the characterization of selective tungsten deposition via disilane reduction of tungsten hexafluoride on a patterned SiO{sub 2}/Si wafer. The high secondary ion yield and the secondary ion emission from a small area produced by highly charged ions make the coincidence technique very powerful.

  5. Attraction between like-charged monovalent ions.

    PubMed

    Zangi, Ronen

    2012-05-14

    Ions with like-charges repel each other with a magnitude given by the Coulomb law. The repulsion is also known to persist in aqueous solutions albeit factored by the medium's dielectric constant. In this paper, we report results from molecular dynamics simulations of alkali halides salt solutions indicating an effective attraction between some of the like-charged monovalent ions. The attraction is observed between anions, as well as between cations, leading to the formation of dimers with lifetimes on the order of few picoseconds. Two mechanisms have been identified to drive this counterintuitive attraction. The first is exhibited by high-charge density ions, such as fluoride, at low salt concentrations, yielding effective attractions with magnitude up to the order of 1-2 kT. In this case, the stronger local electric field generated when the two ions are in contact augments the alignment of neighboring waters toward the ions. This results in a gain of substantial favorable ion-water interaction energy. For fluorides, this interaction constitutes the major change among the different energy components compensating for the anion-anion repulsion, and therefore, rendering like-charge association possible. The second mechanism involves mediation by counterions, the attractions increase with salt concentration and are characterized by small magnitudes. In particular, clusters of ion triplets, in which a counterion is either bridging the two like-charged ions or is paired to only one of them, are formed. Although these two mechanisms may not yield net attractions in many cases, they might still be operational and significant, explaining effective repulsions between like-charged ions with magnitudes much smaller than expected based on continuum electrostatics.

  6. Attraction between like-charged monovalent ions

    NASA Astrophysics Data System (ADS)

    Zangi, Ronen

    2012-05-01

    Ions with like-charges repel each other with a magnitude given by the Coulomb law. The repulsion is also known to persist in aqueous solutions albeit factored by the medium's dielectric constant. In this paper, we report results from molecular dynamics simulations of alkali halides salt solutions indicating an effective attraction between some of the like-charged monovalent ions. The attraction is observed between anions, as well as between cations, leading to the formation of dimers with lifetimes on the order of few picoseconds. Two mechanisms have been identified to drive this counterintuitive attraction. The first is exhibited by high-charge density ions, such as fluoride, at low salt concentrations, yielding effective attractions with magnitude up to the order of 1-2 kT. In this case, the stronger local electric field generated when the two ions are in contact augments the alignment of neighboring waters toward the ions. This results in a gain of substantial favorable ion-water interaction energy. For fluorides, this interaction constitutes the major change among the different energy components compensating for the anion-anion repulsion, and therefore, rendering like-charge association possible. The second mechanism involves mediation by counterions, the attractions increase with salt concentration and are characterized by small magnitudes. In particular, clusters of ion triplets, in which a counterion is either bridging the two like-charged ions or is paired to only one of them, are formed. Although these two mechanisms may not yield net attractions in many cases, they might still be operational and significant, explaining effective repulsions between like-charged ions with magnitudes much smaller than expected based on continuum electrostatics.

  7. Laserspray ionization on a commercial atmospheric pressure-MALDI mass spectrometer ion source: selecting singly or multiply charged ions.

    PubMed

    McEwen, Charles N; Larsen, Barbara S; Trimpin, Sarah

    2010-06-15

    Multiply charged ions, similar to those obtained with electrospray ionization, are produced at atmospheric pressure (AP) using standard MALDI conditions of laser fluence and reflective geometry. Further, the charge state can be switched to singly charged ions nearly instantaneously by changing the voltage applied to the MALDI target plate. Under normal AP-MALDI operating conditions in which a voltage is applied to the target plate, primarily singly charged ions are observed, but at or near zero volts, highly charged ions are observed for peptides and proteins. Thus, switching between singly and multiply charged ions requires only manipulation of a single voltage. As in ESI, multiple charging, produced using the AP-MALDI source, allows compounds with molecular weights beyond the mass-to-charge limit of the mass spectrometer to be observed and improves the fragmentation relative to singly charged ions.

  8. Highly Charged Protein Ions: The Strongest Organic Acids to Date.

    PubMed

    Zenaidee, Muhammad A; Leeming, Michael G; Zhang, Fangtong; Funston, Toby T; Donald, William A

    2017-07-10

    The basicity of highly protonated cytochrome c (cyt c) and myoglobin (myo) ions were investigated using tandem mass spectrometry, ion-molecule reactions (IMRs), and theoretical calculations as a function of charge state. Surprisingly, highly charged protein ions (HCPI) can readily protonate non-polar molecules and inert gases, including Ar, O2 , and N2 in thermal IMRs. The most HCPIs that can be observed are over 130 kJ mol(-1) less basic than the least basic neutral organic molecules known (tetrafluoromethane and methane). Based on theoretical calculations, it is predicted that protonated cyt c and myo ions should spontaneously lose a proton to vacuum for charge states in which every third residue is protonated. In this study, HCPIs are formed where every fourth residue on average is protonated. These results indicate that protein ions in higher charge states can be formed using a low-pressure ion source to reduce proton-transfer reactions between protein ions and gases from the atmosphere. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  9. The ECRIS charge state breeding project at TRIUMF.

    PubMed

    Ames, F; Baartman, R; Bricault, P; Jayamanna, K; McDonald, M; Schmor, P; Spanjers, T; Yuan, D H L; Lamy, T

    2008-02-01

    The performance of charge state breeding with an electron cyclotron resonance (ECR) ion source intended to increase the charge state of online produced radioactive ions at the ISAC facility at TRIUMF has been investigated. A 14 GHz PHOENIX from PANTECHNIK has been setup on a test bench. Singly charged ions have been produced with several ion sources typical for the on-line operation and were injected into the charge breeder. The main purpose of the tests has been the optimization of the efficiency for the charge breeding into the desired charge state. Maximum efficiencies reached so far with the standard one step deceleration of the ions in front of the plasma are up to about 6% for noble gas ions and about 3.5% for alkalines. As ion optics simulations show, the acceptance can be increased by a two step deceleration. In order to meet the velocity acceptance of the accelerator at different A/q values a similar two gap acceleration system for the highly charged ions has been installed to allow the source to run at different voltages. For the further beam transport to the accelerator, cross sections for charge exchange of the highly charged ions with the residual gas have been determined.

  10. Measurement of Metastable Lifetimes of Highly-Charged Ions

    NASA Technical Reports Server (NTRS)

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

    2002-01-01

    The present work is part of a series of measurements of metastable lifetimes of highly-charged ions (HCIs) which contribute to optical absorption, emission and energy balance in the Interstellar Medium (ISM), stellar atmospheres, etc. Measurements were carried out using the 14-GHz electron cyclotron resonance ion source (ECRIS) at the JPL HCI facility. The ECR provides useful currents of charge states such as C(sup(1-6)+), Mg(sup(1-6)+) and Fe(sup(1-17)+). In this work the HCI beam is focused into a Kingdon electrostatic ion trap for measuring lifetimes via optical decays.

  11. Switch between charge transfer and local excited states in 4-aminophenyl-substituted Hantzsch 1,4-dihydropyridine induced by pH change and transition metal ions.

    PubMed

    Chen, Bin; Peng, Ming-Li; Wu, Li-Zhu; Zhang, Li-Ping; Tung, Chen-Ho

    2006-10-01

    The absorption and fluorescence spectra of a Hantzsch 1,4-dihydropyridine derivative bearing a N,N-dimethylaminophenyl group at 4-position (H(2)Py-PhN(CH(3))(2)) in aprotic solvents have been examined and compared to model compounds 4-phenyl- and 4-methyl-substituted Hantzsch 1,4-dihydropyridines (H(2)Py-Ph and H(2)Py-Me). While H(2)Py-Ph and H(2)Py-Me show fluorescence around 420 nm from the local excited state of the dihydropyridine chromophore, H(2)Py-PhN(CH(3))(2) exhibits fluorescence around 520 nm from the intramolecular charge transfer (ICT) state involving the aniline and dihydropyridine groups as donor and acceptor, respectively. Upon addition of an acid to the solution of H(2)Py-PhN(CH(3))(2), the amino group in the aniline is protonated. Thus, the photoinduced intramolecular charge transfer is prevented, and only the fluorescence from the local excited state of the dihydropyridine chromophore can be detected. These changes in the fluorescence behavior are fully reversible: subsequent addition of a base to the acidic solution leads to the recovery of the ICT fluorescence and the quenching of the local fluorescence. Transition metal ions also can switch the fluorescence of H(2)Py-PhN(CH(3))(2). Evidence for the interaction between transition metal ions and the amino group in the dimethylaniline have been provided by absorption and emission spectrum as well as NMR studies.

  12. On-board adaptive model for state of charge estimation of lithium-ion batteries based on Kalman filter with proportional integral-based error adjustment

    NASA Astrophysics Data System (ADS)

    Wei, Jingwen; Dong, Guangzhong; Chen, Zonghai

    2017-10-01

    With the rapid development of battery-powered electric vehicles, the lithium-ion battery plays a critical role in the reliability of vehicle system. In order to provide timely management and protection for battery systems, it is necessary to develop a reliable battery model and accurate battery parameters estimation to describe battery dynamic behaviors. Therefore, this paper focuses on an on-board adaptive model for state-of-charge (SOC) estimation of lithium-ion batteries. Firstly, a first-order equivalent circuit battery model is employed to describe battery dynamic characteristics. Then, the recursive least square algorithm and the off-line identification method are used to provide good initial values of model parameters to ensure filter stability and reduce the convergence time. Thirdly, an extended-Kalman-filter (EKF) is applied to on-line estimate battery SOC and model parameters. Considering that the EKF is essentially a first-order Taylor approximation of battery model, which contains inevitable model errors, thus, a proportional integral-based error adjustment technique is employed to improve the performance of EKF method and correct model parameters. Finally, the experimental results on lithium-ion batteries indicate that the proposed EKF with proportional integral-based error adjustment method can provide robust and accurate battery model and on-line parameter estimation.

  13. Cryogenic linear Paul trap for cold highly charged ion experiments.

    PubMed

    Schwarz, M; Versolato, O O; Windberger, A; Brunner, F R; Ballance, T; Eberle, S N; Ullrich, J; Schmidt, P O; Hansen, A K; Gingell, A D; Drewsen, M; López-Urrutia, J R Crespo

    2012-08-01

    Storage and cooling of highly charged ions require ultra-high vacuum levels obtainable by means of cryogenic methods. We have developed a linear Paul trap operating at 4 K capable of very long ion storage times of about 30 h. A conservative upper bound of the H(2) partial pressure of about 10(-15) mbar (at 4 K) is obtained from this. External ion injection is possible and optimized optical access for lasers is provided, while exposure to black body radiation is minimized. First results of its operation with atomic and molecular ions are presented. An all-solid state laser system at 313 nm has been set up to provide cold Be(+) ions for sympathetic cooling of highly charged ions.

  14. Laser-induced charging of microfabricated ion traps

    NASA Astrophysics Data System (ADS)

    Wang, Shannon X.; Hao Low, Guang; Lachenmyer, Nathan S.; Ge, Yufei; Herskind, Peter F.; Chuang, Isaac L.

    2011-11-01

    Electrical charging of metal surfaces due to photoelectric generation of carriers is of concern in trapped ion quantum computation systems, due to the high sensitivity of the ions' motional quantum states to deformation of the trapping potential. The charging induced by typical laser frequencies involved in Doppler cooling and quantum control is studied here, with microfabricated surface-electrode traps made of aluminum, copper, and gold, operated at 6 K with a single Sr+ ion trapped 100 μm above the trap surface. The lasers used are at 370, 405, 460, and 674 nm, and the typical photon flux at the trap is 1014 photons/cm2/sec. Charging is detected by monitoring the ion's micromotion signal, which is related to the number of charges created on the trap. A wavelength and material dependence of the charging behavior is observed: Lasers at lower wavelengths cause more charging, and aluminum exhibits more charging than copper or gold. We describe the charging dynamic based on a rate-equation approach.

  15. 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.

  16. Wall-loss distribution of charge breeding ions in an electron cyclotron resonance ion source

    SciTech Connect

    Jeong, S. C.; Oyaizu, M.; Imai, N.; Hirayama, Y.; Ishiyama, H.; Miyatake, H.; Niki, K.; Okada, M.; Watanabe, Y. X.; Otokawa, Y.; Osa, A.; Ichikawa, S.

    2011-03-15

    The ion loss distribution in an electron cyclotron resonance ion source (ECRIS) was investigated to understand the element dependence of the charge breeding efficiency in an electron cyclotron resonance (ECR) charge breeder. The radioactive {sup 111}In{sup 1+} and {sup 140}Xe{sup 1+} ions (typical nonvolatile and volatile elements, respectively) were injected into the ECR charge breeder at the Tokai Radioactive Ion Accelerator Complex to breed their charge states. Their respective residual activities on the sidewall of the cylindrical plasma chamber of the source were measured after charge breeding as functions of the azimuthal angle and longitudinal position and two-dimensional distributions of ions lost during charge breeding in the ECRIS were obtained. These distributions had different azimuthal symmetries. The origins of these different azimuthal symmetries are qualitatively discussed by analyzing the differences and similarities in the observed wall-loss patterns. The implications for improving the charge breeding efficiencies of nonvolatile elements in ECR charge breeders are described. The similarities represent universal ion loss characteristics in an ECR charge breeder, which are different from the loss patterns of electrons on the ECRIS wall.

  17. Metrology and Transport of Multiply Charged Ions

    NASA Astrophysics Data System (ADS)

    Kulkarni, Dhruva

    The transport and interaction of singly- and multiply-charged ions with matter has been studied. The experiments were performed in an ultra-high vacuum environment. The low- and hyperthermal-energy ion beamline was used as a source of singly charged ions, while the CUEBIT facility was used as a source of multiply charged ions. The kinetic energy of the ion beam obtained from the CUEBIT is offset from the nominal value expected from the applied electrostatic potentials. These offsets were studied by measuring the kinetic energy of the beam using a retarding field analyzer (RFA). The offset was attributed to the space charge of the electron beam that is used to create the multiply charged ions. The charge density of the electron beam was varied by changing operational parameters of the electron beam, namely the electron beam current and the energy of the electron beam. Ion beams of Ar4+ and Ar8+ were extracted from the source and the offsets observed in the kinetic energy were related to the variation in the space charge potential of the electron beam. Measurements of these offsets, ranging from 100 eV/Q to 300 eV/Q, are significant and important for experiments that aim to utilize the potential energy of slow multiply charged ions. The transport of ions using capillaries has been studied to investigate the viability of ion-guiding as a means for a novel ion delivery mechanism. Results on transport through large bore capillaries (macrocapillaries) that probe both the geometric and ionguided mechanisms are presented. The angle- and position-dependent transport properties were found to depend on the material of the capillary (specifically, whether metal or insulator) and the geometry of the capillary. Rb+ ions at a kinetic energy of 1 keV were transmitted through metal and glass capillaries that were a few centimeters in length and a few millimeters in diameter. Oscillations were observed in the capillaries made of glass which were absent in the metal capillaries

  18. 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.

  19. Utilization of photoinduced charge-separated state of donor-acceptor-linked molecules for regulation of cell membrane potential and ion transport.

    PubMed

    Numata, Tomohiro; Murakami, Tatsuya; Kawashima, Fumiaki; Morone, Nobuhiro; Heuser, John E; Takano, Yuta; Ohkubo, Kei; Fukuzumi, Shunichi; Mori, Yasuo; Imahori, Hiroshi

    2012-04-11

    The control of ion transport across cell membranes by light is an attractive strategy that allows targeted, fast control of precisely defined events in the biological membrane. Here we report a novel general strategy for the control of membrane potential and ion transport by using charge-separation molecules and light. Delivery of charge-separation molecules to the plasma membrane of PC12 cells by a membranous nanocarrier and subsequent light irradiation led to depolarization of the membrane potential as well as inhibition of the potassium ion flow across the membrane. Photoregulation of the cell membrane potential and ion transport by using charge-separation molecules is highly promising for control of cell functions. © 2012 American Chemical Society

  20. Observation of anomalous Iron Ion Charge Distribution in FTU

    SciTech Connect

    Finkenthal, M; May, M; Pacella, D; Leigheb, M; Zagorski, R; Mattioli, M; Fournier, K

    2003-11-14

    Iron coming from the poloidal limiter or the stainless steel vessel is an important intrinsic impurity in the FTU tokamak discharges, and X-ray and VUV spectroscopy provide useful information about the impurity behavior. The iron ion charge state distribution, as usual for tokamaks, is analyzed assuming a collisional radiative model and an anomalous perpendicular diffusion. In our experiment the iron ionization level depends, as it is expected, on central electron temperature (fig. 1), but the ion charge state distribution shows a different behavior when the first wall material or the iron source are changed.

  1. Ion thruster charge-exchange plasma flow

    NASA Technical Reports Server (NTRS)

    Carruth, M. R., Jr.; Gabriel, S. B.; Kitamura, S.

    1982-01-01

    The electron bombardment ion thruster has been under development for a number of years and during this time, studies of the plasmas produced by the thrusters and their interactions with spacecraft have been evaluated, based on available data. Due to diagnostic techniques used and facility effects, there is uncertainty as to the reliability of data from these early studies. This paper presents data on the flow of the charge-exchange plasma produced just downstream of the thruster's ion optics. The 'end-effect' of a cylindrical Langmuir probe is used to determine ion density and directed ion velocity. Results are compared with data obtained from a retarding potential analyzer-Faraday cup.

  2. 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.

  3. Quantum dynamics of charge state in silicon field evaporation

    SciTech Connect

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

    2016-08-15

    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.

  4. Measurement of Doubly Charged Ions in Ion Thruster Plumes

    NASA Technical Reports Server (NTRS)

    Williams, George J., Jr.; Domonkos, Matthew T.; Chavez, Joy M.

    2002-01-01

    The ratio of doubly to singly charged ions was measured in the plumes of a 30 cm and of a 40 cm ion thruster. The measured ratio was correlated with observed erosion rates and thruster operating conditions. The measured and calculated erosion rates paralleled variation in the j(sup ++)/j(sup +) ratio and indicated that the erosion was dominated by Xe III. Simple models of cathode potential surfaces which were developed in support of this work were in agreement with this conclusion and provided a predictive capability of the erosion given the ratio of doubly to singly charged ion currents.

  5. Solar photovoltaic charging of lithium-ion batteries

    NASA Astrophysics Data System (ADS)

    Gibson, Thomas L.; Kelly, Nelson A.

    Solar photovoltaic (PV) charging of batteries was tested by using high efficiency crystalline and amorphous silicon PV modules to recharge lithium-ion battery modules. This testing was performed as a proof of concept for solar PV charging of batteries for electrically powered vehicles. The iron phosphate type lithium-ion batteries were safely charged to their maximum capacity and the thermal hazards associated with overcharging were avoided by the self-regulating design of the solar charging system. The solar energy to battery charge conversion efficiency reached 14.5%, including a PV system efficiency of nearly 15%, and a battery charging efficiency of approximately 100%. This high system efficiency was achieved by directly charging the battery from the PV system with no intervening electronics, and matching the PV maximum power point voltage to the battery charging voltage at the desired maximum state of charge for the battery. It is envisioned that individual homeowners could charge electric and extended-range electric vehicles from residential, roof-mounted solar arrays, and thus power their daily commuting with clean, renewable solar energy.

  6. Time resolved ion beam induced charge collection

    SciTech Connect

    SEXTON,FREDERICK W.; WALSH,DAVID S.; DOYLE,BARNEY L.; DODD,PAUL E.

    2000-04-01

    Under this effort, a new method for studying the single event upset (SEU) in microelectronics has been developed and demonstrated. Called TRIBICC, for Time Resolved Ion Beam Induced Charge Collection, this technique measures the transient charge-collection waveform from a single heavy-ion strike with a {minus}.03db bandwidth of 5 GHz. Bandwidth can be expanded up to 15 GHz (with 5 ps sampling windows) by using an FFT-based off-line waveform renormalization technique developed at Sandia. The theoretical time resolution of the digitized waveform is 24 ps with data re-normalization and 70 ps without re-normalization. To preserve the high bandwidth from IC to the digitizing oscilloscope, individual test structures are assembled in custom high-frequency fixtures. A leading-edge digitized waveform is stored with the corresponding ion beam position at each point in a two-dimensional raster scan. The resulting data cube contains a spatial charge distribution map of up to 4,096 traces of charge (Q) collected as a function of time. These two dimensional traces of Q(t) can cover a period as short as 5 ns with up to 1,024 points per trace. This tool overcomes limitations observed in previous multi-shot techniques due to the displacement damage effects of multiple ion strikes that changed the signal of interest during its measurement. This system is the first demonstration of a single-ion transient measurement capability coupled with spatial mapping of fast transients.

  7. Lithium-Ion Cell Charge Control Unit

    NASA Technical Reports Server (NTRS)

    Reid, Concha; Button, Robert; Manzo, Michelle; McKissock, Barbara; Miller, Thomas; Gemeiner, Russel; Bennett, William; Hand, Evan

    2006-01-01

    Life-test data of Lithium-Ion battery cells is critical in order to establish their performance capabilities for NASA missions and Exploration goals. Lithium-ion cells have the potential to replace rechargeable alkaline cells in aerospace applications, but they require a more complex charging scheme than is typically required for alkaline cells. To address these requirements in our Lithium-Ion Cell Test Verification Program, a Lithium-Ion Cell Charge Control Unit was developed by NASA Glenn Research Center (GRC). This unit gives researchers the ability to test cells together as a pack, while allowing each cell to charge individually. This allows the inherent cell-to-cell variations to be addressed on a series string of cells and results in a substantial reduction in test costs as compared to individual cell testing. The Naval Surface Warfare Center at Crane, Indiana developed a power reduction scheme that works in conjunction with the Lithium-Ion Cell Charge Control Unit. This scheme minimizes the power dissipation required by the circuitry to prolong circuit life and improve its reliability.

  8. Coulomb crystallization of highly charged ions.

    PubMed

    Schmöger, L; Versolato, O O; Schwarz, M; Kohnen, M; Windberger, A; Piest, B; Feuchtenbeiner, S; Pedregosa-Gutierrez, J; Leopold, T; Micke, P; Hansen, A K; Baumann, T M; Drewsen, M; Ullrich, J; Schmidt, P O; López-Urrutia, J R Crespo

    2015-03-13

    Control over the motional degrees of freedom of atoms, ions, and molecules in a field-free environment enables unrivalled measurement accuracies but has yet to be applied to highly charged ions (HCIs), which are of particular interest to future atomic clock designs and searches for physics beyond the Standard Model. Here, we report on the Coulomb crystallization of HCIs (specifically (40)Ar(13+)) produced in an electron beam ion trap and retrapped in a cryogenic linear radiofrequency trap by means of sympathetic motional cooling through Coulomb interaction with a directly laser-cooled ensemble of Be(+) ions. We also demonstrate cooling of a single Ar(13+) ion by a single Be(+) ion-the prerequisite for quantum logic spectroscopy with a potential 10(-19) accuracy level. Achieving a seven-orders-of-magnitude decrease in HCI temperature starting at megakelvin down to the millikelvin range removes the major obstacle for HCI investigation with high-precision laser spectroscopy.

  9. A Phenomenological Model of Bulk Force in a Li-Ion Battery Pack and Its Application to State of Charge Estimation

    SciTech Connect

    Mohan, S; Kim, Y; Siegel, JB; Samad, NA; Stefanopoulou, AG

    2014-09-19

    A phenomenological model of the bulk force exerted by a lithium ion cell during various charge, discharge, and temperature operating conditions is developed. The measured and modeled force resembles the carbon expansion behavior associated with the phase changes during intercalation, as there are ranges of state of charge (SOC) with a gradual force increase and ranges of SOC with very small change in force. The model includes the influence of temperature on the observed force capturing the underlying thermal expansion phenomena. Moreover the model is capable of describing the changes in force during thermal transients, when internal battery heating due to high C-rates or rapid changes in the ambient temperature, which create a mismatch in the temperature of the cell and the holding fixture. It is finally shown that the bulk force model can be very useful for a more accurate and robust SOC estimation based on fusing information from voltage and force (or pressure) measurements. (C) The Author(s) 2014. Published by ECS. This is an open access article distributed under the terms of the Creative Commons Attribution Non-Commercial No Derivatives 4.0 License (CC BY-NC-ND, http://creativecommons.org/licenses/by-nc-nd/4.0/), which permits non-commercial reuse, distribution, and reproduction in any medium, provided the original work is not changed in any way and is properly cited. For permission for commercial reuse, please email oa@electrochem.org. All rights reserved.

  10. Charge-discharge characteristics of all-solid-state thin-filmed lithium-ion batteries using amorphous Nb 2O 5 negative electrodes

    NASA Astrophysics Data System (ADS)

    Nakazawa, Hiromi; Sano, Kimihiro; Abe, Takashi; Baba, Mamoru; Kumagai, Naoaki

    All-solid-state thin-filmed lithium-ion rechargeable batteries composed of amorphous Nb 2O 5 negative electrode with the thickness of 50-300 nm and amorphous Li 2Mn 2O 4 positive electrode with a constant thickness of 200 nm, and amorphous Li 3PO 4- xN x electrolyte (100 nm thickness), have been fabricated on glass substrates with a 50 mm × 50 mm size by a sputtering method, and their electrochemical characteristics were investigated. The charge-discharge capacity based on the volume of positive electrode increased with increasing thickness of negative electrode, reaching about 600 mAh cm -3 for the battery with the negative electrode thickness of 200 nm. But the capacity based on the volume of both the positive and negative electrodes was the maximum value of about 310 mAh cm -3 for the battery with the negative electrode thickness of 100 nm. The shape of charge-discharge curve consisted of a two-step for the batteries with the negative electrode thickness more than 200 nm, but that with the thickness of 100 nm was a smooth S-shape curve during 500 cycles.

  11. X-Ray Diagnostics of CUEBIT Highly Charged Ion Plasma

    NASA Astrophysics Data System (ADS)

    Silwal, Roshani; Gall, Amy; Sosolik, Chad; Harriss, James; Takacs, Endre

    2015-05-01

    Clemson University Electron Beam Ion Trap (CUEBIT) is one of the few EBIT facilities around the globe that produces highly charged ions by successive electron impact ionization. Ions are confined in the machine by the space-charge of the electron beam, a 6 T magnetic field generated by a superconducting magnet, and the voltages applied to axial electrodes. The device is a small laboratory scale instrument for the study of the structure and emission of highly charged ions and the collisions of these ions with external targets. Along with the introduction of the facility including its structure and capabilities, we present an overview of various spectroscopic and imaging tools that allow the diagnosis of the high temperature ion cloud of the CUEBIT. Instruments include a crystal spectrometer, solid-state detectors, and pin-hole imaging setup equipped with an x-ray CCD camera. Measurements of x-ray radiation from CUEBIT are used to investigate the fundamental properties of the highly charged ions and their interaction with the energetic electron beam.

  12. Effect of charge compensator ions (R+ = Li+, Na+ and K+) on Sr2MgSi2O7:Dy3+ phosphors by solid-state reaction method

    NASA Astrophysics Data System (ADS)

    Sahu, Ishwar Prasad

    2016-09-01

    The Sr2MgSi2O7:Dy3+ and Sr2MgSi2O7:Dy3+, R+ (R+ = Li+, Na+ and K+) phosphors were prepared by solid-state reaction method. The crystal structures of sintered phosphors were an akermanite-type structure which belongs to the tetragonal crystallography. The prepared phosphors were excited at 350 nm, and their corresponding emission spectrum were recorded at blue (482 nm) and yellow (575 nm) region due to the 4F9/2 → 6H15/2 and 4F9/2 → 6H13/2 transitions, respectively, of Dy3+ ions. Commission Internationale de L'Eclairage coordinates have been calculated for each sample and its value exhibited that overall emission is near white light. The possible mechanisms of discussed white light emitting phosphors were also investigated. In order to investigate the suitability of the samples as white color light sources for industrial uses, color purity, correlated color temperature (CCT) and color rendering index (CRI) were calculated. Values of color purity, CCT and CRI were found well within the defined acceptable range. With incorporating (R+ = Li+, Na+ and K+) as charge compensator ions, the emission intensity of Sr2MgSi2O7:Dy3+ can be obviously enhanced. The results indicate that prepared phosphors may be a potential application in display devices.

  13. Particle-filtering-based failure prognosis via sigma-points: Application to Lithium-Ion battery State-of-Charge monitoring

    NASA Astrophysics Data System (ADS)

    Acuña, David E.; Orchard, Marcos E.

    2017-02-01

    This paper presents a novel prognostic method that allows a proper characterization of the uncertainty associated with the evolution in time of nonlinear dynamical systems. The method assumes a state-space representation of the system, as well as the availability of particle-filtering-based estimates of the state posterior density at the moment in which the prognostic algorithm is executed. Our proposal significantly improves all particle-filtering-based prognosis frameworks currently available in two main aspects. First, it provides a correction for the expression that is used for the computation of the Time-of-Failure (ToF) probability mass function in the context of online monitoring schemes. Secondly, it presents a method for improved characterization of the tails of the ToF probability mass function via sequential propagation of sigma-points and the computation of Gaussian Mixture Models (GMMs). The proposed algorithm is tested and validated using experimental data related to the problem of Lithium-Ion battery State-of-Charge prognosis.

  14. Electrochemical model based charge optimization for lithium-ion batteries

    NASA Astrophysics Data System (ADS)

    Pramanik, Sourav; Anwar, Sohel

    2016-05-01

    In this paper, we propose the design of a novel optimal strategy for charging the lithium-ion battery based on electrochemical battery model that is aimed at improved performance. A performance index that aims at minimizing the charging effort along with a minimum deviation from the rated maximum thresholds for cell temperature and charging current has been defined. The method proposed in this paper aims at achieving a faster charging rate while maintaining safe limits for various battery parameters. Safe operation of the battery is achieved by including the battery bulk temperature as a control component in the performance index which is of critical importance for electric vehicles. Another important aspect of the performance objective proposed here is the efficiency of the algorithm that would allow higher charging rates without compromising the internal electrochemical kinetics of the battery which would prevent abusive conditions, thereby improving the long term durability. A more realistic model, based on battery electro-chemistry has been used for the design of the optimal algorithm as opposed to the conventional equivalent circuit models. To solve the optimization problem, Pontryagins principle has been used which is very effective for constrained optimization problems with both state and input constraints. Simulation results show that the proposed optimal charging algorithm is capable of shortening the charging time of a lithium ion cell while maintaining the temperature constraint when compared with the standard constant current charging. The designed method also maintains the internal states within limits that can avoid abusive operating conditions.

  15. Production of negatively charged radioactive ion beams

    NASA Astrophysics Data System (ADS)

    Liu, Y.; Stracener, D. W.; Stora, T.

    2017-08-01

    Beams of short-lived radioactive nuclei are needed for frontier experimental research in nuclear structure, reactions, and astrophysics. Negatively charged radioactive ion beams have unique advantages and allow for the use of a tandem accelerator for post-acceleration, which can provide the highest beam quality and continuously variable energies. Negative ion beams can be obtained with high intensity and some unique beam purification techniques based on differences in electronegativity and chemical reactivity can be used to provide beams with high purity. This article describes the production of negative radioactive ion beams at the former holifield radioactive ion beam facility at Oak Ridge National Laboratory and at the CERN ISOLDE facility with emphasis on the development of the negative ion sources employed at these two facilities. ).

  16. Circuit for Full Charging of Series Lithium-Ion Cells

    NASA Technical Reports Server (NTRS)

    Ott, William E.; Saunders, David L.

    2007-01-01

    An advanced charger has been proposed for a battery that comprises several lithium-ion cells in series. The proposal is directed toward charging the cells in as nearly an optimum manner as possible despite unit-to-unit differences among the nominally identical cells. The particular aspect of the charging problem that motivated the proposal can be summarized as follows: During bulk charging (charging all the cells in series at the same current), the voltages of individual cells increase at different rates. Once one of the cells reaches full charge, bulk charging must be stopped, leaving other cells less than fully charged. To make it possible to bring all cells up to full charge once bulk charging has been completed, the proposed charger would include a number of top-off chargers one for each cell. The top-off chargers would all be powered from the same DC source, but their outputs would be DC-isolated from each other and AC-coupled to their respective cells by means of transformers, as described below. Each top-off charger would include a flyback transformer, an electronic switch, and an output diode. For suppression of undesired electromagnetic emissions, each top-off charger would also include (1) a resistor and capacitor configured to act as a snubber and (2) an inductor and capacitor configured as a filter. The magnetic characteristics of the flyback transformer and the duration of its output pulses determine the energy delivered to the lithium-ion cell. It would be necessary to equip the cell with a precise voltage monitor to determine when the cell reaches full charge. In response to a full-charge reading by this voltage monitor, the electronic switch would be held in the off state. Other cells would continue to be charged similarly by their top-off chargers until their voltage monitors read full charge.

  17. Solar Wind Charge Exchange Studies of Highly Charged Ions on Atomic Hydrogen

    SciTech Connect

    Draganic, Ilija N; Seely, D. G.; McCammon, D; Havener, Charles C

    2011-01-01

    Accurate studies of low energy charge exchange (CX) are critical to understanding underlying soft X ray radiation processes in the interaction of highly charged ions from the solar wind with the neutral atoms and molecules in the heliosphere, cometary comas, planetary atmospheres, interstellar winds, etc.. Particularly important are the CX cross sections for bare, H like, and He like ions of C, N, O and Ne, which are the dominant charge states for these heavier elements in the solar wind. Absolute total cross sections for single electron capture by H like ions of C, N, O and fully stripped O ions from atomic hydrogen have been measured in an expanded range of relative collision energies (5 eV u 20 keV u) and compared to previous H oven measurements. The present measurements are performed using a merged beams technique with intense highly charged ion beams extracted from a 14.5 GHz ECR ion source installed on a high voltage platform at the Oak Ridge National Laboratory. For the collision energy range of 0.3 keV u 3.3 keV u, which corresponds to typical ion velocities in the solar wind, the new measurements are in good agreement with previous H oven measurements. The experimental results are discussed in detail and compared with theoretical calculations where available.

  18. Solar Wind Charge Exchange Studies Of Highly Charged Ions On Atomic Hydrogen

    SciTech Connect

    Draganic, I. N.; Havener, C. C.; Seely, D. G.; McCammon, D.

    2011-06-01

    Accurate studies of low-energy charge exchange (CX) are critical to understanding underlying soft X-ray radiation processes in the interaction of highly charged ions from the solar wind with the neutral atoms and molecules in the heliosphere, cometary comas, planetary atmospheres, interstellar winds, etc.. Particularly important are the CX cross sections for bare, H-like, and He-like ions of C, N, O and Ne, which are the dominant charge states for these heavier elements in the solar wind. Absolute total cross sections for single electron capture by H-like ions of C, N, O and fully-stripped O ions from atomic hydrogen have been measured in an expanded range of relative collision energies (5 eV/u-20 keV/u) and compared to previous H-oven measurements. The present measurements are performed using a merged-beams technique with intense highly charged ion beams extracted from a 14.5 GHz ECR ion source installed on a high voltage platform at the Oak Ridge National Laboratory. For the collision energy range of 0.3 keV/u-3.3 keV/u, which corresponds to typical ion velocities in the solar wind, the new measurements are in good agreement with previous H-oven measurements. The experimental results are discussed in detail and compared with theoretical calculations where available.

  19. Review of highly charged heavy ion production with electron cyclotron resonance ion source (invited)

    NASA Astrophysics Data System (ADS)

    Nakagawa, T.

    2014-02-01

    The electron cyclotron resonance ion source (ECRIS) plays an important role in the advancement of heavy ion accelerators and other ion beam applications worldwide, thanks to its remarkable ability to produce a great variety of intense highly charged heavy ion beams. Great efforts over the past decade have led to significant ECRIS performance improvements in both the beam intensity and quality. A number of high-performance ECRISs have been built and are in daily operation or are under construction to meet the continuously increasing demand. In addition, comprehension of the detailed and complex physical processes in high-charge-state ECR plasmas has been enhanced experimentally and theoretically. This review covers and discusses the key components, leading-edge developments, and enhanced ECRIS performance in the production of highly charged heavy ion beams.

  20. Investigation of ion capture in an electron beam ion trap charge-breeder for rare isotopes

    NASA Astrophysics Data System (ADS)

    Kittimanapun, Kritsada

    Charge breeding of rare isotope ions has become an important ingredient for providing reaccelerated rare isotope beams for science. At the National Superconducting Cyclotron Laboratory (NSCL), a reaccelerator, ReA, has been built that employs an advanced Electron Beam Ion Trap (EBIT) as a charge breeder. ReA will provide rare-isotope beams with energies of a few hundred keV/u up to tens of MeV/u to enable the study of properties of rare isotopes via low energy Coulomb excitation and transfer reactions, and to investigate nuclear reactions important for nuclear astrophysics. ReA consists of an EBIT charge breeder, a charge-over-mass selector, a room temperature radio-frequency quadrupole accelerator, and a superconducting radio-frequency linear accelerator. The EBIT charge breeder features a high-current electron gun, a long trap structure, and a hybrid superconducting magnet to reach both high acceptance for injected low-charge ions as well as high-electron beam current densities for fast charge breeding. In this work, continuous ion injection and capture in the EBIT have been investigated with a dedicated Monte-Carlo simulation code and in experimental studies. The Monte-Carlo code NEBIT considers the electron-impact ionization cross sections, space charge due to the electron beam current, ion dynamics, electric field from electrodes, and magnetic field from the superconducting magnet. Experiments were performed to study the capture efficiency as a function of injected ion beam current, electron beam current, trap size, and trap potential depth. The charge state evolution of trapped ions was studied, providing information about the effective current density of the electron beam inside the EBIT. An attempt was made to measure the effective space-charge potential of the electron beam by studying the dynamics of a beam injected and reflected inside the trap.

  1. Transport, charge exchange and loss of energetic heavy ions in the earth's radiation belts - Applicability and limitations of theory

    NASA Technical Reports Server (NTRS)

    Spjeldvik, W. N.

    1981-01-01

    Computer simulations of processes which control the relative abundances of ions in the trapping regions of geospace are compared with observations from discriminating ion detectors. Energy losses due to Coulomb collisions between ions and exospheric neutrals are considered, along with charge exchange losses and internal charge exchanges. The time evolution of energetic ion fluxes of equatorially mirroring ions under radial diffusion is modelled to include geomagnetic and geoelectric fluctutations. Limits to the validity of diffusion transport theory are discussed, and the simulation is noted to contain provisions for six ionic charge states and the source effect on the radiation belt oxygen ion distributions. Comparisons are made with ion flux data gathered on Explorer 45 and ISEE-1 spacecraft and results indicate that internal charge exchanges cause the radiation belt ion charge state to be independent of source charge rate characteristics, and relative charge state distribution is independent of the radially diffusive transport rate below the charge state redistribution zone.

  2. Transport, charge exchange and loss of energetic heavy ions in the earth's radiation belts - Applicability and limitations of theory

    NASA Technical Reports Server (NTRS)

    Spjeldvik, W. N.

    1981-01-01

    Computer simulations of processes which control the relative abundances of ions in the trapping regions of geospace are compared with observations from discriminating ion detectors. Energy losses due to Coulomb collisions between ions and exospheric neutrals are considered, along with charge exchange losses and internal charge exchanges. The time evolution of energetic ion fluxes of equatorially mirroring ions under radial diffusion is modelled to include geomagnetic and geoelectric fluctutations. Limits to the validity of diffusion transport theory are discussed, and the simulation is noted to contain provisions for six ionic charge states and the source effect on the radiation belt oxygen ion distributions. Comparisons are made with ion flux data gathered on Explorer 45 and ISEE-1 spacecraft and results indicate that internal charge exchanges cause the radiation belt ion charge state to be independent of source charge rate characteristics, and relative charge state distribution is independent of the radially diffusive transport rate below the charge state redistribution zone.

  3. Measurement of charge exchange cross sections for highly charged xenon and thorium ions with molecular hydrogen in a Penning Ion Trap

    SciTech Connect

    Weinberg, G.M.

    1995-12-01

    Highly charged xenon (35+ to 46+) and thorium (72+ to 79+) ions were produced in an Electron Beam Ion Trap (EBIT). The ions were extracted from EBIT in a short pulse. Ions of one charge state were selected using an electromagnet. The ions were recaptured at low energy in a cryogenic Penning trap (RETRAP). As the ions captured electrons from molecular hydrogen, populations of the various charge states were obtained by measuring the image currents induced by the ions on the electrodes of the trap. Data on the number of ions in each charge state vs. time were compared to theoretical rate equations in order to determine the average charge exchange rates. These rates were compared to charge exchange rates of an ion with a known charge exchange cross section (Ar{sup 11+}) measured in a similar manner in order to determine the average charge exchange cross sections for the highly charged ions. The energy of interaction between the highly charged ions and hydrogen was estimated to be 4 eV in the center of mass frame. The mean charge exchange cross sections were 9 {times} 10{sup {minus}14} cm{sup 2} for Xe{sup 43+} to Xe{sup 46+} and 2 {times} 10{sup {minus}13} cm{sup 2} for Th{sup 73+} to Th{sup 79+}. Double capture was approximately 20--25% of the total for both xenon and thorium. A fit indicated that the cross sections were approximately proportional to q. This is consistent with a linear dependence of cross section on q within the measurement uncertainties.

  4. Demonstration of charge breeding in a compact room temperature electron beam ion trap

    NASA Astrophysics Data System (ADS)

    Vorobjev, G.; Sokolov, A.; Thorn, A.; Herfurth, F.; Kester, O.; Quint, W.; Stöhlker, Th.; Zschornack, G.

    2012-05-01

    For the first time, a small room-temperature electron beam ion trap (EBIT), operated with permanent magnets, was successfully used for charge breeding experiments. The relatively low magnetic field of this EBIT does not contribute to the capture of the ions; single-charged ions are only caught by the space charge potential of the electron beam. An over-barrier injection method was used to fill the EBIT's electrostatic trap with externally produced, single-charged potassium ions. Charge states as high as K19+ were reached after about a 3 s breeding time. The capture and breeding efficiencies up to 0.016(4)% for K17+ have been measured.

  5. Estimation of state-of-charge and state-of-power capability of lithium-ion battery considering varying health conditions

    NASA Astrophysics Data System (ADS)

    Sun, Fengchun; Xiong, Rui; He, Hongwen

    2014-08-01

    Battery state-of-charge (SoC) and state-of-power capability (SoP) are two of the most significant decision factors for energy management system in electrified vehicles. This paper tries to make two contributions to the existing literature. (1) Based on the adaptive extended Kalman filter algorithm, a data-driven joint estimator for battery SoC and SoP against varying degradations has been developed. (2) To achieve accurate estimations of SoC and SoP in the whole calendar-life of battery, the need for model parameter updates with lowest computation burden has been discussed and studied. The robustness of the joint estimator against dynamic loading profiles and varying health conditions is evaluated. We subsequently used data from cells that have different aging levels to assess the robustness of the SoC and SoP estimation algorithm. The results show that battery SoP has close relationship with its aging levels. And the prediction precision would be significantly improved if recalibrating the parameter of battery capacity and resistance timely. What's more, the method reaches accuracies for new and aged battery cells in electrified vehicle applications of better than 97.5%.

  6. Charge-dependent dissociation of insulin cations via ion/ion electron transfer

    NASA Astrophysics Data System (ADS)

    Liu, Jian; Gunawardena, Harsha P.; Huang, Teng-Yi; McLuckey, Scott A.

    2008-10-01

    The dissociation reactions of various charge states of insulin cations obtained directly from nano-electrospray were investigated as a result of ion/ion electron transfer from azobenzene anions. Data were collected with and without simultaneous ion trap collisional excitation of the first generation charge-reduced product during the ion/ion reaction period. Neither separation of the two constituent chains nor cleavages within the loop defined by the disulfide bridges were observed under normal electron transfer dissociation (ETD) conditions for any of the charge states studied. However, substantial sequence coverage (exocyclic region: 82.6%; entire protein: 38.8%) outside the ring structure was obtained for insulin +6, while only limited coverage (exocyclic: 43.5%; entire protein: 20.4%) was observed for insulin +5 and no dissociation, aside from low abundance side-chain losses, was noted for insulin +4 and +3 in the normal ETD spectra. When the first generation charge-reduced precursor ions were subjected to collisional activation during the ion/ion reaction period, higher sequence coverages were obtained for both insulin +5 (entire protein: 34.7%) and +4 (entire protein: 20.4%) with backbone cleavages occurring within the loop defined by the disulfide bonds. Dissociation of insulin +3 was not significantly improved by the additional activation. Separation of the two constituent chains resulting from cleavages of both of the two disulfide bridges that link the chains was observed for insulin +6, +5, and +4 when the charge-reduced species were activated. The dissociation of disulfide linkages in this study suggests that as the charge state decreases, disulfide bond cleavages dominate over N-C[alpha] bond cleavages in the electron transfer dissociation process.

  7. Hydrogen Ion-Molecule Isotopomer Collisions: Charge Transfer and Rearrangement

    NASA Astrophysics Data System (ADS)

    Wang, J. G.; Stancil, P. C.

    A survey of existing data for collisions of isotopes of hydrogen atoms, ions, and molecules is presented. The survey was limited to atom - diatom ionic collisions and to energies generally less than about 10 keV/u. The processes include particle-rearrangement and charge transfer, including both dissociative and non-dissociative channels, with an emphasis on state-to-state (or state-selected) data, where available. Since the last survey (Linder, Janev and Botero 1995), a small number of investigations for deuterium and tritium ion-diatom systems have been performed, with some involving state-resolved data, which include the initial-state-resolved and state-to-state processes. While some progress has been made since the last survey, the database involving hydrogen isotope collisional processes, both total and state- resolved, is far from complete.

  8. Charge exchange processes involving highly charged ions and targets of interest in astrophysics and fusion plasmas

    NASA Astrophysics Data System (ADS)

    Otranto, S.

    2012-11-01

    Renewed interest in charge exchange processes involving highly charged ions arises because of their crucial role in the planned ITER reactor as well as to recent X-ray observations in the astrophysical context. In this work, the classical trajectory Monte Carlo method (CTMC) is used to calculate state selective single charge exchange n-level cross sections and line emission cross sections pertinent to both fields. These are contrasted to recent laboratory data from KVI for the Xe18+ + Na(3s) collision system and NIST/BERLIN-EBIT data for the Ar18+ +Ar system.

  9. Influence of memory effect on the state-of-charge estimation of large-format Li-ion batteries based on LiFePO4 cathode

    NASA Astrophysics Data System (ADS)

    Shi, Wei; Wang, Jiulin; Zheng, Jianming; Jiang, Jiuchun; Viswanathan, Vilayanur; Zhang, Ji-Guang

    2016-04-01

    In this work, we systematically investigated the influence of the memory effect of LiFePO4 cathodes in large-format full batteries. The electrochemical performance of the electrodes used in these batteries was also investigated separately in half-cells to reveal their intrinsic properties. We noticed that the memory effect of LiFePO4/graphite cells depends not only on the maximum state of charge reached during the memory writing process, but is also affected by the depth of discharge reached during the memory writing process. In addition, the voltage deviation in a LiFePO4/graphite full battery is more complex than in a LiFePO4/Li half-cell, especially for a large-format battery, which exhibits a significant current variation in the region near its terminals. Therefore, the memory effect should be taken into account in advanced battery management systems to further extend the long-term cycling stabilities of Li-ion batteries using LiFePO4 cathodes.

  10. State-selected ion-molecule reactions: The charge-transfer N2+(X,v+)+O2→O2++N2

    NASA Astrophysics Data System (ADS)

    Knott, W. J.; Proch, D.; Kompa, K. L.

    1999-05-01

    The charge-transfer process, which is the subject of this paper, is an important link in the chain of reactive events which occur in the E- and F-regions of the earth's atmosphere. The reaction is suspected to proceed via the formation of a short-lived intermediate complex (N2ṡO2)+. The transient existence of this van der Waals molecule has been inferred from molecular orbital and ab initio arguments. To the present day, however, none of the numerous studies focusing on this system has provided proof of its existence. The positive evidence obtained from this experiment is of an indirect nature, based on measurements of the kinetic energy of the released O2+ as a function of the expendable center-of-mass collision energy. The results point to an indirect reaction (i.e., via an intermediate) in the low energy regime, and a direct process once the center-of-mass energy exceeds the bond energy of the complex. A model description which contracts both pictures matches the complete set of energy-dependent cross section data in a very persuasive manner. A competing reactive channel which has also been given attention results in the formation of NO+. The initiation of this reaction requires a cleavage of the N-N bond, which should be eased by vibrational excitation of the reagent ion. The cross section data, however, turn out to be unaffected by such details of reagent state preparation.

  11. Electron impact ionization of highly charged lithiumlike ions

    SciTech Connect

    Wong, K L

    1992-10-01

    Electron impact ionization cross sections can provide valuable information about the charge-state and power balance of highly charged ions in laboratory and astrophysical plasmas. In the present work, a novel technique based on x-ray measurements has been used to infer the ionization cross section of highly charged lithiumlike ions on the Livermore electron beam ion trap. In particular, a correspondence is established between an observed x ray and an ionization event. The measurements are made at one energy corresponding to approximately 2.3 times the threshold energy for ionization of lithiumlike ions. The technique is applied to the transition metals between Z=22 (titanium, Ti[sup 19+]) and Z=26 (iron, Fe[sup 23+]) and to Z=56 (barium, Ba[sup 53+]). The results for the transition metals, which have an estimated 17-33% uncertainty, are in good overall agreement with a relativistic distorted-wave calculation. However, less good agreement is found for barium, which has a larger uncertainty. Methods for properly accounting for the polarization in the x-ray intensities and for inferring the charge-state abundances from x-ray observations, which were developed for the ionization measurements, as well as an x-ray model that assists in the proper interpretation of the data are also presented.

  12. Atomic physics with highly charged ions. Progress report

    SciTech Connect

    Richard, P.

    1994-08-01

    The study of inelastic collision phenomena with highly charged projectile ions and the interpretation of spectral features resulting from these collisions remain as the major focal points in the atomic physics research at the J.R. Macdonald Laboratory, Kansas State University, Manhattan, Kansas. The title of the research project, ``Atomic Physics with Highly Charged Ions,`` speaks to these points. The experimental work in the past few years has divided into collisions at high velocity using the primary beams from the tandem and LINAC accelerators and collisions at low velocity using the CRYEBIS facility. Theoretical calculations have been performed to accurately describe inelastic scattering processes of the one-electron and many-electron type, and to accurately predict atomic transition energies and intensities for x rays and Auger electrons. Brief research summaries are given for the following: (1) electron production in ion-atom collisions; (2) role of electron-electron interactions in two-electron processes; (3) multi-electron processes; (4) collisions with excited, aligned, Rydberg targets; (5) ion-ion collisions; (6) ion-molecule collisions; (7) ion-atom collision theory; and (8) ion-surface interactions.

  13. Charge exchange lifetimes for ions in the magnetosphere

    NASA Technical Reports Server (NTRS)

    Smith, P. H.; Bewtra, N. K.

    1977-01-01

    Latest and best measurements of physical quantities involved in complete calculation of the charge exchange lifetime of mirroring magnetospheric ions are coalesced and summarized. It is critical that the charge exchange lifetimes for ions be known as accurately as possible in order to apply the charge exchange mechanism to ion phenomena within the earth's magnetosphere.

  14. Pulse Response Yields Battery Charge State

    NASA Technical Reports Server (NTRS)

    Chapman, C. P.; Barber, T. A.

    1984-01-01

    Response to input pulse characterizes state of charge of battery. Instrument electronically measures input and response of forcing-function pulse that periodically modulates charge or discharge current.

  15. Correlated charge-changing ion-atom collisions

    SciTech Connect

    Tanis, J.A.

    1992-04-01

    This report summarizes the progress and accomplishments in accelerator atomic physics research supported by DOE grant DE-FG02-87ER13778 from March 16, 1991 through March 15, 1992. This work involves the experimental investigation of fundamental atomic processes in collisions of charged projectiles with neutral targets or electrons, with particular emphasis on two-electron interactions and electron correlation effects. Processes involving combinations of excitation, ionization, and charge transfer are investigated utilizing coincidence techniques in which projectiles charge-changing events are associated with x-ray emission, target recoil ions, or electron emission. New results have been obtained for studies involving (1) resonant recombination of atomic ions, (2) double ionization of helium, and (3) continuum electron emission. Experiments were conducted using accelerators at the Lawrence Berkeley Laboratory, Argonne National Laboratory, Michigan State University, Western Michigan University, and the Institute of Nuclear Research, Debrecen, Hungary. Brief summaries of work completed and work in progress are given in this report.

  16. Numerical simulation of ion charge breeding in electron beam ion source

    SciTech Connect

    Zhao, L. Kim, Jin-Soo

    2014-02-15

    The Electron Beam Ion Source particle-in-cell code (EBIS-PIC) tracks ions in an EBIS electron beam while updating electric potential self-consistently and atomic processes by the Monte Carlo method. Recent improvements to the code are reported in this paper. The ionization module has been improved by using experimental ionization energies and shell effects. The acceptance of injected ions and the emittance of extracted ion beam are calculated by extending EBIS-PIC to the beam line transport region. An EBIS-PIC simulation is performed for a Cs charge-breeding experiment at BNL. The charge state distribution agrees well with experiments, and additional simulation results of radial profiles and velocity space distributions of the trapped ions are presented.

  17. Formation and fragmentation of quadruply charged molecular ions by intense femtosecond laser pulses.

    PubMed

    Yatsuhashi, Tomoyuki; Nakashima, Nobuaki

    2010-07-22

    We investigated the formation and fragmentation of multiply charged molecular ions of several aromatic molecules by intense nonresonant femtosecond laser pulses of 1.4 mum with a 130 fs pulse duration (up to 2 x 10(14) W cm(-2)). Quadruply charged states were produced for 2,3-benzofluorene and triphenylene molecular ion in large abundance, whereas naphthalene and 1,1'-binaphthyl resulted only in up to triply charged molecular ions. The laser wavelength was nonresonant with regard to the electronic transitions of the neutral molecules, and the degree of fragmentation was strongly correlated with the absorption of the singly charged cation radical. Little fragmentation was observed for naphthalene (off-resonant with cation), whereas heavy fragmentation was observed in the case of 1,1'-binaphthyl (resonant with cation). The degree of H(2) (2H) and 2H(2) (4H) elimination from molecular ions increased as the charge states increased in all the molecules examined. A striking difference was found between triply and quadruply charged 2,3-benzofluorene: significant suppression of molecular ions with loss of odd number of hydrogen was observed in the quadruply charged ions. The Coulomb explosion of protons in the quadruply charged state and succeeding fragmentation resulted in the formation of triply charged molecular ions with an odd number of hydrogens. The hydrogen elimination mechanism in the highly charged state is discussed.

  18. Equilibrium charge states of uranium at relativistic energies

    SciTech Connect

    Crawford, H.; Gould, H.; Greiner, D.; Lindstrom, P.; Symons, J.

    1983-06-01

    We have measured the charge fractions of uranium ions at energies of 962 MeV/amu and 430 MeV/amu passing through various thickness targets of mylar (Z approx. = 6.6), Cu (Z = 29) and Ta (Z = 73). From these we determine the equilibrium charge state distributions.

  19. Improved Control of Charging Voltage for Li-Ion Battery

    NASA Technical Reports Server (NTRS)

    Timmerman, Paul; Bugga, Ratnakumar

    2006-01-01

    The protocol for charging a lithium-ion battery would be modified, according to a proposal, to compensate for the internal voltage drop (charging current internal resistance of the battery). The essence of the modification is to provide for measurement of the internal voltage drop and to increase the terminal-voltage setting by the amount of the internal voltage drop. Ordinarily, a lithium-ion battery is charged at constant current until its terminal voltage attains a set value equal to the nominal full-charge potential. The set value is chosen carefully so as not to exceed the lithium-plating potential, because plated lithium in metallic form constitutes a hazard. When the battery is charged at low temperature, the internal voltage drop is considerable because the electrical conductivity of the battery electrolyte is low at low temperature. Charging the battery at high current at any temperature also gives rise to a high internal voltage drop. In some cases, the internal voltage drop can be as high as 1 volt per cell. Because the voltage available for charging is less than the terminal voltage by the amount of the internal voltage drop, the battery is not fully charged (see figure), even when the terminal voltage reaches the set value. In the modified protocol, the charging current would be periodically interrupted so that the zero-current battery-terminal voltage indicative of the state of charge could be measured. The terminal voltage would also be measured at full charging current. The difference between the full-current and zero-current voltages would equal the internal voltage drop. The set value of terminal voltage would then be increased beyond the nominal full-charge potential by the amount of the internal voltage drop. This adjustment would be performed repeatedly, in real time, so that the voltage setting would track variations in the internal voltage drop to afford full charge without risk of lithium plating. If the charging current and voltage settings

  20. Investigation and optimization of parameters affecting the multiply charged ion yield in AP-MALDI MS.

    PubMed

    Ryumin, Pavel; Brown, Jeffery; Morris, Michael; Cramer, Rainer

    2016-07-15

    Liquid matrix-assisted laser desorption/ionization (MALDI) allows the generation of predominantly multiply charged ions in atmospheric pressure (AP) MALDI ion sources for mass spectrometry (MS) analysis. The charge state distribution of the generated ions and the efficiency of the ion source in generating such ions crucially depend on the desolvation regime of the MALDI plume after desorption in the AP-to-vacuum inlet. Both high temperature and a flow regime with increased residence time of the desorbed plume in the desolvation region promote the generation of multiply charged ions. Without such measures the application of an electric ion extraction field significantly increases the ion signal intensity of singly charged species while the detection of multiply charged species is less dependent on the extraction field. In general, optimization of high temperature application facilitates the predominant formation and detection of multiply charged compared to singly charged ion species. In this study an experimental set-up and optimization strategy is described for liquid AP-MALDI MS which improves the ionization efficiency of selected ion species up to 14 times. In combination with ion mobility separation, the method allows the detection of multiply charged peptide and protein ions for analyte solution concentrations as low as 2fmol/μL (0.5μL, i.e. 1fmol, deposited on the target) with very low sample consumption in the low nL-range. Copyright © 2016. Published by Elsevier Inc.

  1. Laboratory Studies of Thermal Energy Charge Transfer of Silicon and Iron Ions in Astrophysical Plasmas

    NASA Technical Reports Server (NTRS)

    Kwong, Victor H. S.

    1996-01-01

    Charge transfer at electron-volt energies between multiply charged atomic ions and neutral atoms and molecules is of considerable importance in astrophysics, plasma physics, and in particular, fusion plasmas. In the year covered by this report, several major tasks were completed. These include: (1) the re-calibration of the ion gauge to measure the absolute particle densities of H2, He, N2, and CO for our current measurements; (2) the analysis of data for charge transfer reactions of N(exp 2 plus) ion and He, H2, N2, and CO; (3) measurement and data analysis of the charge transfer reaction of (Fe(exp 2 plus) ion and H2; (4) charge transfer measurement of Fe(exp 2 plus) ion and H2; and (5) redesign and modification of the ion detection and data acquisition system for the low energy beam facility (reflection time of flight mass spectrometer) dedicated to the study of state select charge transfer.

  2. Experimental Evidence for Space-Charge Effects between Ions of the Same Mass-to-Charge in Fourier-Transform Ion Cyclotron Resonance Mass Spectrometry

    PubMed Central

    Wong, Richard L.; Amster, I. Jonathan

    2009-01-01

    It is often stated that ions of the same mass-to-charge do not induce space-charge frequency shifts among themselves in an ion cyclotron resonance mass spectrometry measurement. Here, we demonstrate space-charge induced frequency shifts for ions of a single mass-to-charge. The monoisotopic atomic ion, Cs+, was used for this study. The measured frequency is observed to decrease linearly with an increase in the number of ions, as has been reported previously for space-charge effects between ions of different mass-to-charge. The frequency shift between ions of the same m/z value are compared to that induced between ions of different m/z value, and is found to be 7.5 times smaller. Control experiments were performed to ensure that the observed space-charge effects are not artifacts of the measurement or of experimental design. The results can be rationalized by recognizing that the electric forces between ions in a magnetic field conform to the weak form of the Newton's third law, where the action and reaction forces do not cancel exactly. PMID:19562102

  3. Calculating method for confinement time and charge distribution of ions in electron cyclotron resonance sources

    SciTech Connect

    Dougar-Jabon, V.D.; Umnov, A.M.; Kutner, V.B.

    1996-03-01

    It is common knowledge that the electrostatic pit in a core plasma of electron cyclotron resonance sources exerts strict control over generation of ions in high charge states. This work is aimed at finding a dependence of the lifetime of ions on their charge states in the core region and to elaborate a numerical model of ion charge dispersion not only for the core plasmas but for extracted beams as well. The calculated data are in good agreement with the experimental results on charge distributions and magnitudes for currents of beams extracted from the 14 GHz DECRIS source. {copyright} {ital 1996 American Institute of Physics.}

  4. Highly charged ions as a basis of optical atomic clockwork of exceptional accuracy.

    PubMed

    Derevianko, Andrei; Dzuba, V A; Flambaum, V V

    2012-11-02

    We propose a novel class of atomic clocks based on highly charged ions. We consider highly forbidden laser-accessible transitions within the 4f(12) ground-state configurations of highly charged ions. Our evaluation of systematic effects demonstrates that these transitions may be used for building exceptionally accurate atomic clocks which may compete in accuracy with recently proposed nuclear clocks.

  5. Charge-exchange collisions of C 60z+ : a probe of the ion charge distribution

    NASA Astrophysics Data System (ADS)

    Cameron, Douglas B.; Parks, Joel H.

    1997-06-01

    We present Paul trap measurements of charge-exchange collisions of Li, Cs and C 60 with C 60z+ ions ( z = 1-3) at thermal energies. Surprisingly, the measured charge-exchange rates for each neutral species are not proportional to the ion charge z as would be expected for Langevin collisions involving a uniformly charged ion. The relative rates can be reproduced by a model based on a symmetric distribution of point charges that are free to move on the ion surface during the neutral trajectory. Such behavior can be attributed to static and possibly dynamic Jahn-Teller effects in C 60z+ ions.

  6. Beam Extraction from Laser Driven Multi-Charged Ion Source

    SciTech Connect

    Anderson, O A; Logan, B G

    2001-03-19

    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. They discuss extraction and focusing for the particular case of a 4.1-MV beam of Xe{sup 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. The design studies were carried out first with an envelope code and then with a self-consistent particle code. Results from the 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. They conclude with an improved design which increases the surviving beam to more than 70 amperes.

  7. The behavior of ions near a charged wall - dependence on ion size, concentration and surface charge

    PubMed Central

    Howard, Jesse J.; Perkyns, John S.

    2010-01-01

    A renormalization of the 3D-RISM-HNC integral equation is used to study the solvent and ion distributions at neutral and negatively charged planar atomistic surfaces. The charge density of the surfaces ranged from 0.0 to 0.4116 C/m2 and the modeled electrolyte solutions consist of the salts NaCl, KCl, and CsCl at concentrations of 0.1M, 0.25M and 1.0M in SPC/E water. The results are qualitatively compared to the results from other integral equation methods and simulations for similar models. We find that the 3D-IEs predict an electric multilayer screening behavior in the solvent and ion distributions in contrast to the double layer anticipated from Poisson-Boltzmann theory. It is observed that the cation size has a significant effect on the distributions near the surface up to 3 solvation layers beyond which the behavior is the same among the different cations. The response of the distributions to the charged surface is described as an increase in ion and solvent density near the wall. The higher concentration solutions screen the electrostatic source more strongly at the wall as expected. The importance of ion-solvent and ion-ion correlations near the surface are shown through 3-body correlation functions which are obtainable from the 3D-IEs in this study. PMID:20405885

  8. (The physics of highly charged ions)

    SciTech Connect

    Phaneuf, R.A.

    1990-10-12

    The Fifth International Conference on the Physics of Highly Charged Ions drew more than 200 participants, providing an excellent overview of this growing field. Important technical developments and experimental results in electron-ion collisions were reported. The merging of fast ion beams from accelerators or storage rings with advanced high-intensity electron-beam targets has yielded data of unprecedented quality on radiative and dielectronic recombination, providing stringent tests of theory. Long-awaited technical innovations in electron-impact excitation measurements were also reported. The level of activity in multicharged ion-surface interactions has increased. More sophisticated experimental studies of the neutralization process have shown the inadequacy of previously accepted mechanisms, and theoretical activity in this area is just being initiated. The IAEA meetings addressed atomic and molecular data needs for fusion research, with ITER providing a key focus. Such data are especially critical to modeling and diagnostics of the edge plasma. The ALADDIN data base system has been universally accepted and has streamlined the exchange of numerical data among data centers and the fusion community. The IAEA continues to play a pivotal role in the identification of data needs, and in the coordination of data compilation and research activities for fusion applications.

  9. Ion-induced interactions between charged macroions and dielectric inhomogeneities

    NASA Astrophysics Data System (ADS)

    Zwanikken, Jos; Olvera de La Cruz, Monica

    2012-02-01

    We present a theoretical study of the interactions between macroions in ionic solutions, that are induced by the surrounding electrolyte. In a first scenario, we consider responsive nanoparticles with positively and negatively charged surface groups, and predict that thermal fluctuations of the net surface charge are responsible for an effective attraction, as a chemical analogue of the atomic London-forces. In a second scenario, we consider nanoparticles in solvents with a low dielectric permittivity, where the Coulomb interactions between ions easily exceed the thermal energy. We predict an ionic condensation in the confinement between two nearby nanoparticles, where the suppression of fluctuations leads to a locally dense state of ions, and a consequent strong effective attraction between the nanoparticles. The induced potential between the nanoparticles is also related to the ion-nanoparticle interactions, by e.g. Van der Waals, surface charge, or image charge attractions. Recently developed theoretical methods are discussed, based on earlier work [1,2]. [4pt] [1] J. W. Zwanikken, and M. Olvera de la Cruz, Phys. Rev. E 82, 050401(R) (2010). [0pt] [2] J. W. Zwanikken, P. K. Jha, and M. Olvera de la Cruz, J. Chem. Phys. 135, 064106 (2011);

  10. Charge transfer between O{sup +} ions and helium

    SciTech Connect

    Zhao, L.B.; Stancil, P.C.; Liebermann, H.P.; Funke, P.; Buenker, R.J.

    2005-06-15

    The charge-transfer processes O{sup +}({sup 4}S{sup 0},{sup 2}D{sup 0},{sup 2}P{sup 0})+He{yields}O({sup 3}P)+He{sup +} have been investigated by using a fully quantal molecular-orbital close-coupling (QMOCC) approach. Cross sections are presented for ion energies from 0.5 to 10 keV and compared with those from recent experiments and semiclassical theory. Good agreement is found between the QMOCC results and the measurements. Particular attention is given to addressing the metastable component of the experimental ion beams. We further argue that the so-called 'suppressed electron-capture effect' for metastable ions proposed by Wolfrum et al. is not a viable mechanism to explain their measurements. However, the current QMOCC calculations were found to reproduce neither the ground-state nor metastable-state cross sections predicted by the semiclassical method.

  11. Electron excited multiply charged argon ions studied by means of an energy resolved electron-ion coincidence technique

    NASA Astrophysics Data System (ADS)

    Kumar, Sunil; Prajapati, Suman; Singh, Bhupendra; Singh, Bhartendu Kumar; Shanker, Rama

    2017-03-01

    Multiply charged argon ions produced from decay of L-shell hole states by impact of a continuous beam of 3.5 keV electrons are studied for the first time using an energy resolved electron-ion coincidence technique. The TOF spectra of argon ions are measured in coincidence with 18-energy selected electrons emitted in a wide energy range (126-242 eV). The coincidence measurement between the energy selected electrons and the correlated ions specifies the individual decay channel for various multiply charged ions. New experimental data are obtained and reported on the correlation probability for production of argon ions with charge states 1+ to 4+ as a function of ejected electrons in the considered energy range. The relative correlation probability of producing different charge state ions and corresponding physical processes involved in their production are presented and discussed. It has been found that the maximum probability for production of Ar2+ ions correlated to ejected Auger electrons in the energy range of 205-209 eV is 100%. No theoretical predictions are available to compare with these results. The present study shows further that not only the auto-ionization and normal Auger transitions but also several other decay processes including Coster-Kronig transitions followed by Auger cascades with a fraction of shake process play important role in producing ions with charge states 1+ to 4+.

  12. Potential sputtering of ionic species from rare gas solids by multiply charged ion impact

    NASA Astrophysics Data System (ADS)

    Fukai, K.; Fujita, S.; Tachibana, T.; Koizumi, T.; Hirayama, T.

    2010-03-01

    The interaction of low-energy multiply charged Arq + (q <= 7) ions with a solid Ne surface is experimentally studied. Desorption of very large cluster ions Nen + (n > 100) is observed. The size distribution of smaller (n = 1-3) cluster ions depends strongly on the charge state of the incident ion, whereas that of larger (n > 7) cluster ions exhibits no dependence on the charge state, indicating that desorption of large cluster ions is due to kinetic sputtering. The potential sputtering yield is estimated by analyzing the size distribution of the desorbed cluster ions. The results suggest that the ion desorption mechanism, which is known as desorption induced by electronic transitions, can also be applied to explain the present results.

  13. An electrostatic deceleration lens for highly charged ions.

    PubMed

    Rajput, J; Roy, A; Kanjilal, D; Ahuja, R; Safvan, C P

    2010-04-01

    The design and implementation of a purely electrostatic deceleration lens used to obtain beams of highly charged ions at very low energies is presented. The design of the lens is such that it can be used with parallel as well as diverging incoming beams and delivers a well focused low energy beam at the target. In addition, tuning of the final energy of the beam over a wide range (1 eV/q to several hundred eV/q, where q is the beam charge state) is possible without any change in hardware configuration. The deceleration lens was tested with Ar(8+), extracted from an electron cyclotron resonance ion source, having an initial energy of 30 keV/q and final energies as low as 70 eV/q have been achieved.

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

    NASA Astrophysics Data System (ADS)

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

    2011-06-01

    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 A. 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 + surface ionization ion source for externally pulsed injection into the BNL Test EBIS. A Cs + ion beam with a total number of ions of 5×10 8 and optimized pulse length of 70 μs has been injected into the Test EBIS and charge-bred for 5.3 ms for two different electron beam currents - 1 and 1.5 A. In these experiments we have achieved 70% injection/extraction efficiency and breeding efficiency into the most abundant charge state ˜17%.

  15. 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%.

  16. Charge neutralization apparatus for ion implantation system

    DOEpatents

    Leung, Ka-Ngo; Kunkel, Wulf B.; Williams, Malcom D.; McKenna, Charles M.

    1992-01-01

    Methods and apparatus for neutralization of a workpiece such as a semiconductor wafer in a system wherein a beam of positive ions is applied to the workpiece. The apparatus includes an electron source for generating an electron beam and a magnetic assembly for generating a magnetic field for guiding the electron beam to the workpiece. The electron beam path preferably includes a first section between the electron source and the ion beam and a second section which is coincident with the ion beam. The magnetic assembly generates an axial component of magnetic field along the electron beam path. The magnetic assembly also generates a transverse component of the magnetic field in an elbow region between the first and second sections of the electron beam path. The electron source preferably includes a large area lanthanum hexaboride cathode and an extraction grid positioned in close proximity to the cathode. The apparatus provides a high current, low energy electron beam for neutralizing charge buildup on the workpiece.

  17. Trajectory effects in multiply charged ion-surface interactions

    SciTech Connect

    Lebius, H.; Huang, W.; Schuch, R.

    1999-06-10

    Ar ions of 4.3 keV q{sub in} were scattered at large angles ({theta}=75 degree sign ) from a clean oriented surface. By selecting Ar projectiles having a large ionization potential and by using a large scattering angle only ions scattered at the first atomic layer of the surface were detected. Scattered ion energy spectra show peaks of single scattering and double scattering of the Ar projectile ions from one or two surface Au atoms, and the distribution attributed to double collisions splits into two peaks when the scattering plane coincides with a crystallographic plane. Simulations with a MARLOWE code allowed for interpretation of the structure in the double collision peak by in-plane and zig-zag double collisions. Differences in the relative peak heights between the experiment and a MARLOWE simulation were partly explained by different neutralization probabilities with varying trajectories. Yield changes with increasing charge states show interesting possibilities for future experiments with highly charged ions.

  18. Highly charged Ar{sup q+} ions interacting with metals

    SciTech Connect

    Wang Jijin; Zhang Jian; Gu Jiangang; Luo Xianwen; Hu Bitao

    2009-12-15

    Using computer simulation, alternative methods of the interaction of highly charged ions Ar{sup q+} with metals (Au, Ag) are used and verified in the present work. Based on the classical over-barrier model, we discussed the promotion loss and peeling off processes. The simulated total potential electron yields agree well with the experiment data in incident energy ranging from 100 eV to 5 keV and all charge states of Ar{sup q+}. Based on the TRIM code, we obtain the side-feeding rate as well as the motion and charge transfer of HCI below the surface. Some results, including the array of KL{sup x} x-ray satellite lines, the respective contribution of autoionization, and side-feeding to inner shells, and the filling rates and lifetime of inner shells for Ar agree well with experiment or theory.

  19. New development of laser ion source for highly charged ion beam production at Institute of Modern Physics (invited).

    PubMed

    Zhao, H Y; Zhang, J J; Jin, Q Y; Liu, W; Wang, G C; Sun, L T; Zhang, X Z; Zhao, H W

    2016-02-01

    A laser ion source based on Nd:YAG laser has been being studied at the Institute of Modern Physics for the production of high intensity high charge state heavy ion beams in the past ten years, for possible applications both in a future accelerator complex and in heavy ion cancer therapy facilities. Based on the previous results for the production of multiple-charged ions from a wide range of heavy elements with a 3 J/8 ns Nd:YAG laser [Zhao et al., Rev. Sci. Instrum. 85, 02B910 (2014)], higher laser energy and intensity in the focal spot are necessary for the production of highly charged ions from the elements heavier than aluminum. Therefore, the laser ion source was upgraded with a new Nd:YAG laser, the maximum energy of which is 8 J and the pulse duration can be adjusted from 8 to 18 ns. Since then, the charge state distributions of ions from various elements generated by the 8 J Nd:YAG laser were investigated for different experimental conditions, such as laser energy, pulse duration, power density in the focal spot, and incidence angle. It was shown that the incidence angle is one of the most important parameters for the production of highly charged ions. The capability of producing highly charged ions from the elements lighter than silver was demonstrated with the incidence angle of 10° and laser power density of 8 × 10(13) W cm(-2) in the focal spot, which makes a laser ion source complementary to the superconducting electron cyclotron resonance ion source for the future accelerator complex especially in terms of the ion beam production from some refractory elements. Nevertheless, great efforts with regard to the extraction of intense ion beams, modification of the ion beam pulse duration, and reliability of the ion source still need to be made for practical applications.

  20. New development of laser ion source for highly charged ion beam production at Institute of Modern Physics (invited)

    NASA Astrophysics Data System (ADS)

    Zhao, H. Y.; Zhang, J. J.; Jin, Q. Y.; Liu, W.; Wang, G. C.; Sun, L. T.; Zhang, X. Z.; Zhao, H. W.

    2016-02-01

    A laser ion source based on Nd:YAG laser has been being studied at the Institute of Modern Physics for the production of high intensity high charge state heavy ion beams in the past ten years, for possible applications both in a future accelerator complex and in heavy ion cancer therapy facilities. Based on the previous results for the production of multiple-charged ions from a wide range of heavy elements with a 3 J/8 ns Nd:YAG laser [Zhao et al., Rev. Sci. Instrum. 85, 02B910 (2014)], higher laser energy and intensity in the focal spot are necessary for the production of highly charged ions from the elements heavier than aluminum. Therefore, the laser ion source was upgraded with a new Nd:YAG laser, the maximum energy of which is 8 J and the pulse duration can be adjusted from 8 to 18 ns. Since then, the charge state distributions of ions from various elements generated by the 8 J Nd:YAG laser were investigated for different experimental conditions, such as laser energy, pulse duration, power density in the focal spot, and incidence angle. It was shown that the incidence angle is one of the most important parameters for the production of highly charged ions. The capability of producing highly charged ions from the elements lighter than silver was demonstrated with the incidence angle of 10° and laser power density of 8 × 1013 W cm-2 in the focal spot, which makes a laser ion source complementary to the superconducting electron cyclotron resonance ion source for the future accelerator complex especially in terms of the ion beam production from some refractory elements. Nevertheless, great efforts with regard to the extraction of intense ion beams, modification of the ion beam pulse duration, and reliability of the ion source still need to be made for practical applications.

  1. New development of laser ion source for highly charged ion beam production at Institute of Modern Physics (invited)

    SciTech Connect

    Zhao, H. Y. Zhang, J. J.; Jin, Q. Y.; Sun, L. T.; Zhang, X. Z.; Zhao, H. W.; Liu, W.; Wang, G. C.

    2016-02-15

    A laser ion source based on Nd:YAG laser has been being studied at the Institute of Modern Physics for the production of high intensity high charge state heavy ion beams in the past ten years, for possible applications both in a future accelerator complex and in heavy ion cancer therapy facilities. Based on the previous results for the production of multiple-charged ions from a wide range of heavy elements with a 3 J/8 ns Nd:YAG laser [Zhao et al., Rev. Sci. Instrum. 85, 02B910 (2014)], higher laser energy and intensity in the focal spot are necessary for the production of highly charged ions from the elements heavier than aluminum. Therefore, the laser ion source was upgraded with a new Nd:YAG laser, the maximum energy of which is 8 J and the pulse duration can be adjusted from 8 to 18 ns. Since then, the charge state distributions of ions from various elements generated by the 8 J Nd:YAG laser were investigated for different experimental conditions, such as laser energy, pulse duration, power density in the focal spot, and incidence angle. It was shown that the incidence angle is one of the most important parameters for the production of highly charged ions. The capability of producing highly charged ions from the elements lighter than silver was demonstrated with the incidence angle of 10° and laser power density of 8 × 10{sup 13} W cm{sup −2} in the focal spot, which makes a laser ion source complementary to the superconducting electron cyclotron resonance ion source for the future accelerator complex especially in terms of the ion beam production from some refractory elements. Nevertheless, great efforts with regard to the extraction of intense ion beams, modification of the ion beam pulse duration, and reliability of the ion source still need to be made for practical applications.

  2. Charge Breeding Techniques in an Electron Beam Ion Trap for High Precision Mass Spectrometry at TITAN

    NASA Astrophysics Data System (ADS)

    MacDonald, T. D.; Simon, M. C.; Bale, J. C.; Chowdhury, U.; Eibach, M.; Gallant, A. T.; Lennarz, A.; Simon, V. V.; Chaudhuri, A.; Grossheim, A.; Kwiatkowski, A. A.; Schultz, B. E.; Dilling, J.

    2012-10-01

    Penning trap mass spectrometry is the most accurate and precise method available for performing atomic mass measurements. TRIUMF's Ion Trap for Atomic and Nuclear science is currently the only facility to couple its Penning trap to a rare isotope facility and an electron beam ion trap (EBIT). The EBIT is a valuable tool for beam preparation: since the precision scales linearly with the charge state, it takes advantage of the precision gained by using highly charged ions. However, this precision gain is contingent on fast and efficient charge breeding. An optimization algorithm has been developed to identify the optimal conditions for running the EBIT. Taking only the mass number and half-life of the isotope of interest as inputs, the electron beam current density, charge breeding time, charge state, and electron beam energy are all specified to maximize this precision. An overview of the TITAN charge breeding program, and the results of charge breeding simulations will be presented.

  3. Multiply charged carbon-ion production for medical application

    SciTech Connect

    Kitagawa, A.; Muramatsu, M.; Sasaki, N.; Takasugi, W.; Wakaisami, S.; Biri, S.; Drentje, A. G.

    2008-02-15

    Over 3000 cancer patients have already been treated by the heavy-ion medical accelerator in Chiba at the National Institute of Radiological Sciences since 1994. The clinical results have clearly verified the effectiveness and safety of heavy-ion radiotherapy. The most important result has been to establish that the carbon ion is one of the most effective radiations for radiotherapy. The ion source is required to realize a stable beam with the same conditions for daily operation. However, the deposition of carbon ions on the wall of the plasma chamber is normally unavoidable. This causes an ''anti-wall-coating effect,'' i.e., a decreasing of the beam, especially for the higher charge-state ions due to the surface material of the wall. The ion source must be required to produce a sufficiently intense beam under the bad condition. Other problems were solved by improvements and maintenance, and thus we obtained enough reproducibility and stability along with decreased failures. We summarize our over 13 years of experience, and show the scope for further developments.

  4. Lithium-Ion Cell Charge-Control Unit Developed

    NASA Technical Reports Server (NTRS)

    Reid, Concha M.; Manzo, Michelle A.; Buton, Robert M.; Gemeiner, Russel

    2005-01-01

    A lithium-ion (Li-ion) cell charge-control unit was developed as part of a Li-ion cell verification program. This unit manages the complex charging scheme that is required when Li-ion cells are charged in series. It enables researchers to test cells together as a pack, while allowing each cell to charge individually. This allows the inherent cell-to-cell variations to be addressed on a series string of cells and reduces test costs substantially in comparison to individual cell testing.

  5. Influence of the density of states on the odd-even staggering in the charge distribution of the emitted fragments in nuclear heavy-ion collisions

    NASA Astrophysics Data System (ADS)

    Calleya, N. L.; Souza, S. R.; Carlson, B. V.; Donangelo, R.; Lynch, W. G.; Tsang, M. B.; Winkelbauer, J. R.

    2014-11-01

    The fragmentation of thermalized sources is studied using a version of the Statistical Multifragmentation Model which employs state densities that take the pairing gap in the nuclear levels into account. Attention is focused on the properties of the charge distributions observed in the breakup of the source. Since the microcanonical version of the model used in this study provides the primary fragment excitation energy distribution, one may correlate the reduction of the odd-even staggering in the charge distribution with the increasing occupation of high-energy states. Thus, in the framework of this model, such staggering tends to disappear as a function of the total excitation energy of the source, although the energy per particle may be small for large systems. We also find that, although the deexcitation of the primary fragments should, in principle, blur these odd-even effects as the fragments follow their decay chains, the consistent treatment of pairing may significantly enhance these staggering effects on the final yields. In the framework of this model, we find that odd-even effects in the charge distributions should be observed in the fragmentation of relatively light systems at very low excitation energies. Our results also suggest that the odd-even staggering may provide useful information on the nuclear state density.

  6. Solvated calcium ions in charged silica nanopores

    NASA Astrophysics Data System (ADS)

    Bonnaud, Patrick A.; Coasne, Benoît; Pellenq, Roland J.-M.

    2012-08-01

    Hydroxyl surface density in porous silica drops down to nearly zero when the pH of the confined aqueous solution is greater than 10.5. To study such extreme conditions, we developed a model of slit silica nanopores where all the hydrogen atoms of the hydroxylated surface are removed and the negative charge of the resulting oxygen dangling bonds is compensated by Ca2+ counterions. We employed grand canonical Monte Carlo and molecular dynamics simulations to address how the Ca2+ counterions affect the thermodynamics, structure, and dynamics of confined water. While most of the Ca2+ counterions arrange themselves according to the so-called "Stern layer," no diffuse layer is observed. The presence of Ca2+ counterions affects the pore filling for strong confinement where the surface effects are large. At full loading, no significant changes are observed in the layering of the first two adsorbed water layers compared to nanopores with fully hydroxylated surfaces. However, the water structure and water orientational ordering with respect to the surface is much more disturbed. Due to the super hydrophilicity of the Ca2+-silica nanopores, water dynamics is slowed down and vicinal water molecules stick to the pore surface over longer times than in the case of hydroxylated silica surfaces. These findings, which suggest the breakdown of the linear Poisson-Boltzmann theory, provide important information about the properties of nanoconfined electrolytes upon extreme conditions where the surface charge and ion concentration are large.

  7. The multiple conformational charge states of zinc(II) coordination by 2His-2Cys oligopeptide investigated by ion mobility-mass spectrometry, density functional theory and theoretical collision cross sections.

    PubMed

    Wagoner, Stephanie M; Deeconda, Manogna; Cumpian, Kayleah L; Ortiz, Rafael; Chinthala, Swetha; Angel, Laurence A

    2016-12-01

    Whether traveling wave ion mobility-mass spectrometry (IM-MS), B3LYP/LanL2DZ density functional theory, and ion size scaled Lennard-Jones (LJ) collision cross sections (CCS) from the B3LYP optimized structures could be used to determine the type of Zn(II) coordination by the oligopeptide acetyl-His1 -Cys2 -Gly3 -Pro4 -Tyr5 -His6 -Cys7 (amb5 ) was investigated. The IM-MS analyses of a pH titration of molar equivalents of Zn(II):amb5 showed that both negatively and positively charged complexes formed and coordination of Zn(II) increased as the His and Cys deprotonated near their pKa values. The B3LYP method was used to generate a series of alternative coordination structures to compare with the experimental results. The method predicted that the single negatively charged complex coordinated Zn(II) in a distorted tetrahedral geometry via the 2His-2Cys substituent groups, whereas, the double negatively charged and positively charged complexes coordinated Zn(II) via His, carbonyl oxygens and the C-terminus. The CCS of the B3LYP complexes were calculated using the LJ method and compared with those measured by IM-MS for the various charge state complexes. The LJ method provided CCS that agreed with five of the alternative distorted tetrahedral and trigonal bipyramidal coordinations for the doubly charged complexes, but provided CCS that were 15 to 31 Å(2) larger than those measured by IM-MS for the singly charged complexes. Collision-induced dissociation of the Zn(II) complexes and a further pH titration study of amb5B , which included amidation of the C-terminus, suggested that the 2His-2Cys coordination was more significant than coordinations that included the C-terminus. Copyright © 2016 John Wiley & Sons, Ltd.

  8. Diagnostics of a charge breeder electron cyclotron resonance ion source helium plasma with the injection of 23Na1+ ions

    NASA Astrophysics Data System (ADS)

    Tarvainen, O.; Koivisto, H.; Galatà, A.; Angot, J.; Lamy, T.; Thuillier, T.; Delahaye, P.; Maunoury, L.; Mascali, D.; Neri, L.

    2016-05-01

    This work describes the utilization of an injected 23Na1+ ion beam as a diagnostics of the helium plasma of a charge breeder electron cyclotron resonance ion source. The obtained data allows estimating the upper limit for the ion-ion collision mean-free path of the incident sodium ions, the lower limit of ion-ion collision frequencies for all charge states of the sodium ions and the lower limit of the helium plasma density. The ion-ion collision frequencies of high charge state ions are shown to be at least on the order of 1-10 MHz and the plasma density is estimated to be on the order of 1011 cm-3 or higher. The experimental results are compared to simulations of the 23Na1+ capture into the helium plasma. The results indicate that the lower breeding efficiency of light ions in comparison to heavier elements is probably due to different capture efficiencies in which the in-flight ionization of the incident 1 + ions plays a vital role.

  9. Ionization of highly charged iodine ions near the Bohr velocity

    NASA Astrophysics Data System (ADS)

    Zhou, Xianming; Cheng, Rui; Lei, Yu; Sun, Yuanbo; Ren, Jieru; Liu, Shidong; Deng, Jiachuan; Zhao, Yongtao; Xiao, Guoqing

    2015-01-01

    We have measured the L-shell X-rays of iodine from the collisions of 3 MeV Iq+(q=15,20,22,25,26) ions with an iron target. It is found that the X-ray yield decreases with the increasing initial charge state. The energy of the subshell X-ray has a blue shift, which is independent of the projectile charge state. In addition, the relative intensity ratios of Lβ1,3,4 and Lβ2,15 to Lα1,2 X-ray are obtained and compared with the theoretical calculations. That they are larger than for a singly ionized atom can be understood by the multiple ionization effect of the outer-shell electrons.

  10. Charge Exchange Cross Sections for Multiply-Charged Ions Colliding with Water

    SciTech Connect

    Otranto, S.; Olson, R. E.

    2009-03-10

    The classical trajectory Monte Carlo method is used to calculate total and state selective nl-electron capture cross sections for highly charged ions Z = 4-10, 14, 18 and 26 colliding with water. The initialization for the 1B1 and 3A1 orbitals of the water molecule is based on a Slater orbital expansion. The Z-dependence of the calculated total cross sections is in reasonable agreement with recent data. The K-shell x-ray emission cross sections are determined from the calculated state-selective electron capture results.

  11. Cooling of highly charged ions in a Penning trap

    SciTech Connect

    Gruber, Lukas

    2000-03-31

    Highly charged ions are extracted from an electron beam ion trap and guided to Retrap, a cryogenic Penning trap, where they are merged with laser cooled Be+ ions. The Be+ ions act as a coolant for the hot highly charged ions and their temperature is dropped by about 8 orders of magnitude in a few seconds. Such cold highly charged ions form a strongly coupled nonneutral plasma exhibiting, under such conditions, the aggregation of clusters and crystals. Given the right mixture, these plasmas can be studied as analogues of high density plasmas like white dwarf interiors, and potentially can lead to the development of cold highly charged ion beams for applications in nanotechnology. Due to the virtually non existent Doppler broadening, spectroscopy on highly charged ions can be performed to an unprecedented precision. The density and the temperature of the Be+ plasma were measured and highly charged ions were sympathetically cooled to similar temperatures. Molecular dynamics simulations confirmed the shape, temperature and density of the highly charged ions. Ordered structures were observed in the simulations.

  12. Slow highly charged ion induced nanopit formation on the KCl(001) surface

    NASA Astrophysics Data System (ADS)

    Wilhelm, R. A.; Heller, R.; Facsko, S.

    2016-08-01

    We report on nanostructuring of the KCl(001) surface induced by the individual impact of slow highly charged ions. Samples were irradiated with Xe ions with charge states of Q = 15 to 40 at kinetic energies from 1.7 to 160 keV. The formation of nanopits at the virgin surface is observed and attributed to a defect-mediated desorption process involving the removal of up to 2000 surface atoms per incident ion. The depth of the produced pits is shallow, but not limited to the first monolayer. From the variation of the ion parameters (charge state and kinetic energy) we derive a phase diagram for the structuring of the KCl(001) surface with highly charged ions.

  13. Transfer ionization in collisions with a fast highly charged ion.

    PubMed

    Voitkiv, A B

    2013-07-26

    Transfer ionization in fast collisions between a bare ion and an atom, in which one of the atomic electrons is captured by the ion whereas another one is emitted, crucially depends on dynamic electron-electron correlations. We show that in collisions with a highly charged ion a strong field of the ion has a very profound effect on the correlated channels of transfer ionization. In particular, this field weakens (strongly suppresses) electron emission into the direction opposite (perpendicular) to the motion of the ion. Instead, electron emission is redirected into those parts of the momentum space which are very weakly populated in fast collisions with low charged ions.

  14. High sensitivity charge amplifier for ion beam uniformity monitor

    DOEpatents

    Johnson, Gary W.

    2001-01-01

    An ion beam uniformity monitor for very low beam currents using a high-sensitivity charge amplifier with bias compensation. The ion beam monitor is used to assess the uniformity of a raster-scanned ion beam, such as used in an ion implanter, and utilizes four Faraday cups placed in the geometric corners of the target area. Current from each cup is integrated with respect to time, thus measuring accumulated dose, or charge, in Coulombs. By comparing the dose at each corner, a qualitative assessment of ion beam uniformity is made possible. With knowledge of the relative area of the Faraday cups, the ion flux and areal dose can also be obtained.

  15. Aircraft battery state of charge and charge control system

    NASA Astrophysics Data System (ADS)

    Viswanathan, S.; Charkey, A.

    1986-02-01

    This Interim Report describes work done in developing an aircraft battery state of charge and charge control system. The basis for this system developed by ERC is a nickel-oxygen (NiO2) Pilot cell (0.374 Ah). This pilot cell is cycled in tandem with a nickel-cadmium battery. The oxygen pressure of the pilot cell is utilized to determine and control the state of charge of the nickel-cadmium battery. The NiO2 pilot cell baseline performance was determined during this period. The effect of using different nickel electrodes (ERC, SAFT, MARATHON) was also performed.

  16. 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.

  17. Capture and isolation of highly charged ions in a unitary Penning trap

    NASA Astrophysics Data System (ADS)

    Brewer, Samuel M.; Guise, Nicholas D.; Tan, Joseph N.

    2013-12-01

    We recently used a compact Penning trap to capture and isolate highly charged ions extracted from an electron beam ion trap (EBIT) at the National Institute of Standards and Technology. Isolated charge states of highly stripped argon and neon ions with total charge Q≥10, extracted at energies of up to 4×103Q eV, are captured in a trap with well depths of ≈(4-12)Q eV. Here we discuss in detail the process to optimize velocity tuning, capture, and storage of highly charged ions in a unitary Penning trap designed to provide easy radial access for atomic or laser beams in charge exchange or spectroscopic experiments, such as those of interest for proposed studies of one-electron ions in Rydberg states or optical transitions of metastable states in multiply charged ions. Under near-optimal conditions, ions captured and isolated in such rare-earth Penning traps can be characterized by an initial energy distribution that is ≈60 times narrower than typically found in an EBIT. This reduction in thermal energy is obtained passively, without the application of any active cooling scheme in the ion-capture trap.

  18. Ion momentum and energy transfer rates for charge exchange collisions

    NASA Technical Reports Server (NTRS)

    Horwitz, J.; Banks, P. M.

    1973-01-01

    The rates of momentum and energy transfer have been obtained for charge exchange collisions between ion and neutral gases having arbitrary Maxwellian temperatures and bulk transport velocities. The results are directly applicable to the F-region of the ionosphere where 0+ - 0 charge is the dominant mechanism affecting ion momentum and energy transfer.

  19. Problems with Accurate Atomic Lfetime Measurements of Multiply Charged Ions

    SciTech Connect

    Trabert, E

    2009-02-19

    A number of recent atomic lifetime measurements on multiply charged ions have reported uncertainties lower than 1%. Such a level of accuracy challenges theory, which is a good thing. However, a few lessons learned from earlier precision lifetime measurements on atoms and singly charged ions suggest to remain cautious about the systematic errors of experimental techniques.

  20. Maximizing Ion Current by Space Charge Neutralization using Negative Ions and Dust Particles

    SciTech Connect

    A. Smirnov; Y. Raitses; N.J. Fisch

    2005-01-25

    Ion current extracted from an ion source (ion thruster) can be increased above the Child-Langmuir limit if the ion space charge is neutralized. Similarly, the limiting kinetic energy density of the plasma flow in a Hall thruster might be exceeded if additional mechanisms of space charge neutralization are introduced. Space charge neutralization with high-mass negative ions or negatively charged dust particles seems, in principle, promising for the development of a high current or high energy density source of positive light ions. Several space charge neutralization schemes that employ heavy negatively charged particles are considered. It is shown that the proposed neutralization schemes can lead, at best, only to a moderate but nonetheless possibly important increase of the ion current in the ion thruster and the thrust density in the Hall thruster.

  1. Charge-exchange born He(+) ions in the solar wind

    NASA Technical Reports Server (NTRS)

    Gruntman, Michael A.

    1992-01-01

    The effect of charge transfer between solar wind alpha-particles and hydrogen atoms of interstellar origin is revisited. Singly-charged helium ions born in the charge transfer carry important information on processes in the solar wind and the heliosphere. The velocity distribution of such He(+) ions is substantially different from that of He(+) pick-up ions due to ionization of the interstellar helium atoms. Estimates of the expected abundances of the charge-exchange born He(+) in the solar wind are presented, and the possibility of measuring this plasma component on deep space missions is discussed.

  2. Highly charged ions from laser-cluster interactions: local-field-enhanced impact ionization and frustrated electron-ion recombination.

    PubMed

    Fennel, Thomas; Ramunno, Lora; Brabec, Thomas

    2007-12-07

    Our molecular dynamics analysis of Xe_{147-5083} clusters identifies two mechanisms that contribute to the yet unexplained observation of extremely highly charged ions in intense laser cluster experiments. First, electron impact ionization is enhanced by the local cluster electric field, increasing the highest charge states by up to 40%; a corresponding theoretical method is developed. Second, electron-ion recombination after the laser pulse is frustrated by acceleration electric fields typically used in ion detectors. This increases the highest charge states by up to 90%, as compared to the usual assumption of total recombination of all cluster-bound electrons. Both effects together augment the highest charge states by up to 120%, in reasonable agreement with experiments.

  3. Highly Charged Ions from Laser-Cluster Interactions: Local-Field-Enhanced Impact Ionization and Frustrated Electron-Ion Recombination

    SciTech Connect

    Fennel, Thomas; Ramunno, Lora; Brabec, Thomas

    2007-12-07

    Our molecular dynamics analysis of Xe{sub 147-5083} clusters identifies two mechanisms that contribute to the yet unexplained observation of extremely highly charged ions in intense laser cluster experiments. First, electron impact ionization is enhanced by the local cluster electric field, increasing the highest charge states by up to 40%; a corresponding theoretical method is developed. Second, electron-ion recombination after the laser pulse is frustrated by acceleration electric fields typically used in ion detectors. This increases the highest charge states by up to 90%, as compared to the usual assumption of total recombination of all cluster-bound electrons. Both effects together augment the highest charge states by up to 120%, in reasonable agreement with experiments.

  4. Space-charge dynamics in ultra-cold ion bunches

    NASA Astrophysics Data System (ADS)

    Scholten, Robert; Murphy, Dene; Speirs, Rory; Thompson, Daniel; Sparkes, Benjamin; McCulloch, Andrew

    2014-05-01

    Cold ion sources based on photoionisation of laser cooled atoms provide a unique system for investigating Coulomb interactions within complex charged particle bunches. Space-charge driven expansion in charged particle beams is of critical importance for applications including electron and ion microscopy, mass spectrometry, synchrotrons and x-ray free electron lasers, and in electron diffraction where space-charge effects constrain the capacity to obtain diffraction information. Self-field effects are often difficult to observe because of thermal diffusion with traditional sources. Cold atom sources produce ions with temperatures of a few mK, such that subtle space-charge effects are apparent. We illustrate the capabilities through detailed investigation of a complex ion bunch shape, showing collective behaviour including high density caustics and shockwave structures arising from long-range interactions between small charge bunches.

  5. Ion charge neutralization effects in scanning electron microscopes.

    PubMed

    Crawford, C K

    1980-01-01

    The use of low energy ion charge neutralization to stabilize surface potentials in scanning microscopes leads to the observation of new effects. Among the most important of these, are effects which result from the primary beam being scanned in a raster. A new theory which describes raster charge-up for highly insulating specimens is presented. It is shown that the required neutralizing ion current is a surprisingly strong function of the primary electron current, the raster parameters, specimen parameters, and magnification. Contrary to intuition, the required ion current is not linearly related to the primary electron current. Methods of adjusting parameters to achieve better ion charge neutralization are discussed.

  6. An Ion Switch Regulates Fusion of Charged Membranes

    PubMed Central

    Siepi, Evgenios; Lutz, Silke; Meyer, Sylke; Panzner, Steffen

    2011-01-01

    Here we identify the recruitment of solvent ions to lipid membranes as the dominant regulator of lipid phase behavior. Our data demonstrate that binding of counterions to charged lipids promotes the formation of lamellar membranes, whereas their absence can induce fusion. The mechanism applies to anionic and cationic liposomes, as well as the recently introduced amphoteric liposomes. In the latter, an additional pH-dependent lipid salt formation between anionic and cationic lipids must occur, as indicated by the depletion of membrane-bound ions in a zone around pH 5. Amphoteric liposomes fuse under these conditions but form lamellar structures at both lower and higher pH values. The integration of these observations into the classic lipid shape theory yielded a quantitative link between lipid and solvent composition and the physical state of the lipid assembly. The key parameter of the new model, κ(pH), describes the membrane phase behavior of charged membranes in response to their ion loading in a quantitative way. PMID:21575575

  7. Highly charged ion based time of flight emission microscope

    DOEpatents

    Barnes, Alan V.; Schenkel, Thomas; Hamza, Alex V.; Schneider, Dieter H.; Doyle, Barney

    2001-01-01

    A highly charged ion based time-of-flight emission microscope has been designed, which improves the surface sensitivity of static SIMS measurements because of the higher ionization probability of highly charged ions. Slow, highly charged ions are produced in an electron beam ion trap and are directed to the sample surface. The sputtered secondary ions and electrons pass through a specially designed objective lens to a microchannel plate detector. This new instrument permits high surface sensitivity (10.sup.10 atoms/cm.sup.2), high spatial resolution (100 nm), and chemical structural information due to the high molecular ion yields. The high secondary ion yield permits coincidence counting, which can be used to enhance determination of chemical and topological structure and to correlate specific molecular species.

  8. Demonstration of charge breeding in a compact room temperature electron beam ion trap

    SciTech Connect

    Vorobjev, G.; Sokolov, A.; Herfurth, F.; Kester, O.; Quint, W.; Stoehlker, Th.; Thorn, A.; Zschornack, G.

    2012-05-15

    For the first time, a small room-temperature electron beam ion trap (EBIT), operated with permanent magnets, was successfully used for charge breeding experiments. The relatively low magnetic field of this EBIT does not contribute to the capture of the ions; single-charged ions are only caught by the space charge potential of the electron beam. An over-barrier injection method was used to fill the EBIT's electrostatic trap with externally produced, single-charged potassium ions. Charge states as high as K{sup 19+} were reached after about a 3 s breeding time. The capture and breeding efficiencies up to 0.016(4)% for K{sup 17+} have been measured.

  9. Comments on velocity space relaxation in high charge-state plasma neutralizers

    SciTech Connect

    Hershcovitch, A.

    1989-01-01

    Scaling of velocity space relaxation rates, which affect the final temperature of a natural beam, with ion charge state in plasma neutralizers is examined. Overall, this scaling indicates a substantial enhancement in emittance growth of the neutral beam with increase in the charge state of ions in plasma neutralizers. 9 refs.

  10. Charge transfer reactions in multiply charged ion-atom collisions. [in interstellar clouds

    NASA Technical Reports Server (NTRS)

    Steigman, G.

    1975-01-01

    Charge-transfer reactions in collisions between highly charged ions and neutral atoms of hydrogen and/or helium may be rapid at thermal energies. If these reactions are rapid, they will suppress highly charged ions in H I regions and guarantee that the observed absorption features from such ions cannot originate in the interstellar gas. A discussion of such charge-transfer reactions is presented and compared with the available experimental data. The possible implications of these reactions for observations of the interstellar medium, H II regions, and planetary nebulae are outlined.

  11. Optimization of electron-cyclotron-resonance charge-breeder ions : Final CRADA Report.

    SciTech Connect

    Pardo, R.; Physics; Far-Tech, Inc.

    2009-10-09

    Measurements of 1+ beam properties and associated performance of ECR Charge Breeder source determined by total efficiency measurement and charge state distributions from the ECR Charge Breeder. These results were communicated to Far-Tech personnel who used them to benchmark the newly developed programs that model ion capture and charge breeding in the ECR Charge Breeder Source. Providing the basic data described above and in the discussion below to Far-Tech allowed them to improve and refine their calculational tools for ECR ion sources. These new tools will be offered for sale to industry and will also provide important guidance to other research labs developing Charge Breeding ion sources for radioactive beam physics research.

  12. Cell design and image analysis for in situ Raman mapping of inhomogeneous state-of-charge profiles in lithium-ion batteries

    NASA Astrophysics Data System (ADS)

    Fang, Shuyu; Yan, Min; Hamers, Robert J.

    2017-06-01

    The study of inhomogeneous battery failure processes requires proper tools with high spatial resolving power. Here we describe a simple way to adapt industry-standard coin cells to enable in situ Raman mapping of lithium-ion battery materials. We describe the important cell design parameters and validate that the design achieves a uniform potential distribution within the region probed by Raman. We further validate that the cell yields electrical performance characteristics equivalent to a standard, non-modified coin cell. Using this cell, we probe the local charging profiles of LiNi0.5Mn0.3Co0.2O2 (;NMC;) particles during cycling and demonstrate the ability to achieve spatial maps of the Raman spectra. In order to reduce the effects of local topography, we further analyze these data by numerically extracting the local frequency of the A1g vibrational mode, which is sensitive to the local extent of lithiation, and producing spatial maps of the local frequency of the A1g mode. This work demonstrates a way to collect and analyze high quality in situ spectra with an easy-to-implement cell design that can be applied to a wide range of electrode materials.

  13. Wall-loss distribution of charge breeding ions in an electron cyclotron resonance ion source

    SciTech Connect

    Jeong, S. C.; Oyaizu, M.; Imai, N.; Hirayama, Y.; Ishiyama, H.; Miyatake, H.; Niki, K.; Okada, M.; Watanabe, Y. X.; Otokawa, Y.; Osa, A.; Ichikawa, S.

    2012-02-15

    We investigated the ion-loss distribution on the sidewall of an electron cyclotron resonance (ECR) plasma chamber using the 18-GHz ECR charge breeder at the Tokai Radioactive Ion Accelerator Complex (TRIAC). Similarities and differences between the ion-loss distributions (longitudinal and azimuthal) of different ion species (i.e., radioactive {sup 111}In{sup 1+} and {sup 140}Xe{sup 1+} ions that are typical volatile and nonvolatile elements) was qualitatively discussed to understand the element dependence of the charge breeding efficiency. Especially, the similarities represent universal ion loss characteristics in an ECR charge breeder, which are different from the loss patterns of electrons on the ECRIS wall.

  14. High Mass Ion Detection with Charge Detector Coupled to Rectilinear Ion Trap Mass Spectrometer

    NASA Astrophysics Data System (ADS)

    Patil, Avinash A.; Chou, Szu-Wei; Chang, Pei-Yu; Lee, Chen-Wei; Cheng, Chun-Yen; Chu, Ming-Lee; Peng, Wen-Ping

    2016-12-01

    Conventional linear ion trap mass analyzers (LIT-MS) provide high ion capacity and show their MS n ability; however, the detection of high mass ions is still challenging because LIT-MS with secondary electron detectors (SED) cannot detect high mass ions. To detect high mass ions, we coupled a charge detector (CD) to a rectilinear ion trap mass spectrometer (RIT-MS). Immunoglobulin G ions (m/z 150,000) are measured successfully with controlled ion kinetic energy. In addition, when mass-to-charge (m/z) ratios of singly charged ions exceed 10 kTh, the detection efficiency of CD is found to be greater than that of SED. The CD can be coupled to LIT-MS to extend the detection mass range and provide the potential to perform MS n of high mass ions inside the ion trap.

  15. High Mass Ion Detection with Charge Detector Coupled to Rectilinear Ion Trap Mass Spectrometer

    NASA Astrophysics Data System (ADS)

    Patil, Avinash A.; Chou, Szu-Wei; Chang, Pei-Yu; Lee, Chen-Wei; Cheng, Chun-Yen; Chu, Ming-Lee; Peng, Wen-Ping

    2017-06-01

    Conventional linear ion trap mass analyzers (LIT-MS) provide high ion capacity and show their MS n ability; however, the detection of high mass ions is still challenging because LIT-MS with secondary electron detectors (SED) cannot detect high mass ions. To detect high mass ions, we coupled a charge detector (CD) to a rectilinear ion trap mass spectrometer (RIT-MS). Immunoglobulin G ions ( m/ z 150,000) are measured successfully with controlled ion kinetic energy. In addition, when mass-to-charge ( m/ z) ratios of singly charged ions exceed 10 kTh, the detection efficiency of CD is found to be greater than that of SED. The CD can be coupled to LIT-MS to extend the detection mass range and provide the potential to perform MS n of high mass ions inside the ion trap. [Figure not available: see fulltext.

  16. State promotion and neutralization оf ions near metal surface

    NASA Astrophysics Data System (ADS)

    Zinoviev, A. N.

    2011-05-01

    When a multiply charged ion with charge Z approaches the metal surface, a dipole is formed by the multiply charged ion and the charge induced in the metal. The states for such a dipole are promoted into continuum with decreasing ion-surface distance and cross the states formed from metal atom. The model proposed explains the dominant population of deep bound states in collisions considered.

  17. A singly charged ion source for radioactive 11C ion acceleration

    NASA Astrophysics Data System (ADS)

    Katagiri, K.; Noda, A.; Nagatsu, K.; Nakao, M.; Hojo, S.; Muramatsu, M.; Suzuki, K.; Wakui, T.; Noda, K.

    2016-02-01

    A new singly charged ion source using electron impact ionization has been developed to realize an isotope separation on-line system for simultaneous positron emission tomography imaging and heavy-ion cancer therapy using radioactive 11C ion beams. Low-energy electron beams are used in the electron impact ion source to produce singly charged ions. Ionization efficiency was calculated in order to decide the geometric parameters of the ion source and to determine the required electron emission current for obtaining high ionization efficiency. Based on these considerations, the singly charged ion source was designed and fabricated. In testing, the fabricated ion source was found to have favorable performance as a singly charged ion source.

  18. A singly charged ion source for radioactive {sup 11}C ion acceleration

    SciTech Connect

    Katagiri, K.; Noda, A.; Nagatsu, K.; Nakao, M.; Hojo, S.; Muramatsu, M.; Suzuki, K.; Wakui, T.; Noda, K.

    2016-02-15

    A new singly charged ion source using electron impact ionization has been developed to realize an isotope separation on-line system for simultaneous positron emission tomography imaging and heavy-ion cancer therapy using radioactive {sup 11}C ion beams. Low-energy electron beams are used in the electron impact ion source to produce singly charged ions. Ionization efficiency was calculated in order to decide the geometric parameters of the ion source and to determine the required electron emission current for obtaining high ionization efficiency. Based on these considerations, the singly charged ion source was designed and fabricated. In testing, the fabricated ion source was found to have favorable performance as a singly charged ion source.

  19. The role of space charge compensation for ion beam extraction and ion beam transport (invited)

    SciTech Connect

    Spädtke, Peter

    2014-02-15

    Depending on the specific type of ion source, the ion beam is extracted either from an electrode surface or from a plasma. There is always an interface between the (almost) space charge compensated ion source plasma, and the extraction region in which the full space charge is influencing the ion beam itself. After extraction, the ion beam is to be transported towards an accelerating structure in most cases. For lower intensities, this transport can be done without space charge compensation. However, if space charge is not negligible, the positive charge of the ion beam will attract electrons, which will compensate the space charge, at least partially. The final degree of Space Charge Compensation (SCC) will depend on different properties, like the ratio of generation rate of secondary particles and their loss rate, or the fact whether the ion beam is pulsed or continuous. In sections of the beam line, where the ion beam is drifting, a pure electrostatic plasma will develop, whereas in magnetic elements, these space charge compensating electrons become magnetized. The transport section will provide a series of different plasma conditions with different properties. Different measurement tools to investigate the degree of space charge compensation will be described, as well as computational methods for the simulation of ion beams with partial space charge compensation.

  20. Defect mediated desorption of the KBr(001) surface induced by single highly charged ion impact.

    PubMed

    Heller, R; Facsko, S; Wilhelm, R A; Möller, W

    2008-08-29

    The individual impacts of slow (300 eV/amu) highly charged Xe ions induce nanometer sized pitlike structures on the KBr (001) surface. The volume of these structures shows a strong dependence on the ions potential energy. Total potential sputter yields from atomically flat (001) terraces are determined by imaging single ion impact sites. The dependence of the sputter yield on the ions initial charge state combined with structure formation at low and high-fluence irradiations indicates that agglomeration of defects into complex centers plays a major role in the desorption process induced by the potential energy.

  1. Highly charged ions in magnetic fusion plasmas: research opportunities and diagnostic necessities

    NASA Astrophysics Data System (ADS)

    Beiersdorfer, P.

    2015-07-01

    Highly charged ions play a crucial role in magnetic fusion plasmas. These plasmas are excellent sources for producing highly charged ions and copious amounts of radiation for studying their atomic properties. These studies include calibration of density diagnostics, x-ray production by charge exchange, line identifications and accurate wavelength measurements, and benchmark data for ionization balance calculations. Studies of magnetic fusion plasmas also consume a large amount of atomic data, especially in order to develop new spectral diagnostics. Examples we give are the need for highly accurate wavelengths as references for measurements of bulk plasma motion, the need for accurate line excitation rates that encompass both electron-impact excitation and indirect line formation processes, for accurate position and resonance strength information of dielectronic recombination satellite lines that may broaden or shift diagnostic lines or that may provide electron temperature information, and the need for accurate ionization balance calculations. We show that the highly charged ions of several elements are of special current interest to magnetic fusion, notably highly charged ions of argon, iron, krypton, xenon, and foremost of tungsten. The electron temperatures thought to be achievable in the near future may produce W70+ ions and possibly ions with even higher charge states. This means that all but a few of the most highly charged ions are of potential interest as plasma diagnostics or are available for basic research.

  2. Ab initio Determination of Formation Energies and Charge Transfer Levels of Charged Ions in Water

    NASA Astrophysics Data System (ADS)

    Vatti, Anoop Kishore; Todorova, Mira; Neugebauer, Joerg

    The ability to describe the complex atomic and electronic structure of liquid water and hydrated ions on a microscopic level is a key requirement to understand and simulate electro-chemical and biological processes. Identifying theoretical concepts which enable us to achieve an accurate description in a computationally efficient way is thereby of central importance. Aiming to unravel the importance and influence of different contributions on the hydration energy of ions we perform extensive ab-initio molecular dynamics simulations for charged and neutral cations (Zn, Mg) and anions (Cl, Br, I) in water. The structural correlations and electronic properties of the studied ions are analysed and compared to experimental observations. Following an approach inspired by the defect chemistry in semiconductors and aligning the water band edges on an absolute scale allows us to benchmark the calculated formation energies, identify transition states and compare the results to experiment. Based on these results we discuss the performance of various DFT xc-functionals to predict charge transfer levels and photo-emission experiments.

  3. Status of Charge Exchange Cross Section Measurements for Highly Charged Ions on Atomic Hydrogen

    NASA Astrophysics Data System (ADS)

    Draganic, I. N.; Havener, C. C.; Schultz, D. R.; Seely, D. G.; Schultz, P. C.

    2011-05-01

    Total cross sections of charge exchange (CX) for C5+, N6+, and O7+ ions on ground state atomic hydrogen are measured in an extended collision energy range of 1 - 20,000 eV/u. Absolute CX measurements are performed using an improved merged-beams technique with intense highly charged ion beams extracted from a 14.5 GHz ECR ion source mounted on a high voltage platform. In order to improve the problematic H+ signal collection for these exoergic CX collisions at low relative energies, a new double focusing electrostatic analyzer was installed. Experimental CX data are in good agreement with all previous H-oven relative measurements at higher collision energies. We compare our results with the most recent molecular orbital close-coupling (MOCC) and atomic orbital close-coupling (AOCC) theoretical calculations. Work supported by the NASA Solar & Heliospheric Physics Program NNH07ZDA001N, the Office of Fusion Energy Sciences and the Division of Chemical Sciences, Geosciences, and Biosciences, and the Office of Basic Energy Sciences of the U.S. DoE.

  4. Dust charging effects on test charge potential in a multi-ion dusty plasma

    NASA Astrophysics Data System (ADS)

    Ali, S.

    2009-11-01

    The Debye-Hückel and oscillatory wake potentials caused by a test charge are studied in a multi-ion dusty plasma, whose constituents are the Boltzmann distributed electrons and light positive ions, the heavy mobile negative ions, and static but charge fluctuating dust particles. For this purpose, fluid equations are employed to obtain the dielectric constant of the dust-negative-ion acoustic wave involving the negative ions and dust charge fluctuation effects. Theoretical and numerical investigations have revealed the modification in the Debye-Hückel and wake potentials due to the effects of dust relaxation rate, dust absorption frequency, dust grain radius, and negative ion temperature. The present results should be important to form new materials in the presence of negative ions in laboratory as well as dust coagulation/agglomeration in space dusty plasmas.

  5. Possible Diamond-Like Nanoscale Structures Induced by Slow Highly-Charged Ions on Graphite (HOPG)

    SciTech Connect

    Sideras-Haddad, E.; Schenkel, T.; Shrivastava, S.; Makgato, T.; Batra, A.; Weis, C. D.; Persaud, A.; Erasmus, R.; Mwakikunga, B.

    2009-01-06

    The interaction between slow highly-charged ions (SHCI) of different charge states from an electron-beam ion trap and highly oriented pyrolytic graphite (HOPG) surfaces is studied in terms of modification of electronic states at single-ion impact nanosizeareas. Results are presented from AFM/STM analysis of the induced-surface topological features combined with Raman spectroscopy. I-V characteristics for a number of different impact regions were measured with STM and the results argue for possible formation of diamond-like nanoscale structures at the impact sites.

  6. Time-dependent cylindrical and spherical ion-acoustic solitary structures in relativistic degenerate multi-ion plasmas with positively-charged heavy ions

    NASA Astrophysics Data System (ADS)

    Hossen, M. R.; Nahar, L.; Mamun, A. A.

    2014-12-01

    The properties of time-dependent cylindrical and spherical, modified ion-acoustic (mIA) solitary structures in relativistic degenerate multi-ion plasmas (containing degenerate electron fluids, inertial positively-, as well as negatively-, charged light ions, and positively-charged static heavy ions) have been investigated theoretically. This investigation is valid for both non-relativistic and ultra-relativistic limits. The well-known reductive perturbation method has been used to derive the Korteweg-de Vries (K-dV) and the mK-dV equations for studying the basic features of solitary waves. The fundamental characteristics of mIA solitary waves are found to be significantly modified by the effects of the degenerate pressures of the electron and the ion fluids, their number densities, and the various charge states of heavy ions. The relevance of our results in astrophysical compact objects like white dwarfs and neutron stars, which are of scientific interest, is briefly discussed.

  7. Space-charge limits of ion sensitive probes

    NASA Astrophysics Data System (ADS)

    Brunner, D.; LaBombard, B.; Ochoukov, R.; Sullivan, R.; Whyte, D.

    2013-12-01

    Ion sensitive probes (ISPs) are used to measure ion temperature and plasma potential in magnetized plasmas. Their operation relies on the difference in electron and ion Larmor radii to preferentially collect the ion species on a recessed electrode. Because of their simple two-electrode construction and optimal geometry for heat flux handling they are an attractive probe to use in the high heat flux boundary of magnetic confinement fusion experiments. However, the integrity of its measurements is rarely, if ever, checked under such conditions. Recent measurements with an ISP in the Alcator C-Mod tokamak have shown that its ion current is space-charge limited and thus its current-voltage (I-V) response does not contain information on the ion temperature. We numerically solve a 1D Vlasov-Poisson model of ion collection to determine how much bias is needed to overcome space-charge effects and regain the classic I-V characteristic with an exponential decay. Prompted by the observations of space charge in C-Mod, we have performed a survey of ISP measurements reported in the literature. Evidence of space-charge limited current collection is found on many probes, with few authors noting its presence. Some probes are able to apparently exceed the classic 1D space-charge limit because electrons can E × B drift into the probe volume, partially reducing the net ion charge; it is argued that this does not, however, change the basic problem that space charge compromises the measurement of ion temperature. Guidance is given for design of ISPs to minimize the effects of space charge.

  8. Special issue on the spectroscopy of highly-charged ions

    NASA Astrophysics Data System (ADS)

    Nakamura, Nobuyuki; Ralchenko, Yuri; Stöhlker, Thomas

    2014-07-01

    Journal of Physics B: Atomic, Molecular and Optical Physics is delighted to announce a forthcoming special issue on the spectroscopy of highly-charged ions, to appear in the early summer of 2015, and invites you to submit a paper. From fusion to astrophysics to EUV lithography, highly-charged ions (HCI) are used to diagnose plasma properties, create new powerful sources of light and even verify the most fundamental theories. Since the mere creation of such multiply-stripped atoms requires extreme temperature or energies, their radiation is frequently the only physical data available to researchers. Even so, the HCI spectra provide a variety of rich and detailed information on ion properties and environment conditions. Over the last couple of decades, spectroscopy of HCI has been given a strong impetus through the development of both compact (e.g. electron beam ion traps) and large-scale (e.g. tokamaks, stellarators, storage rings) machines capable of efficiently producing atoms that are ionized fifty, sixty, or even ninety times. This, in turn, triggered the development of new experimental and theoretical techniques to measure and analyze HCI spectra and to use this radiation for plasma diagnostics. The purpose of this special issue will be to provide an extensive account of the state of the art in this thriving area of atomic physics. The covered topics, in particular, will include (but not be limited to): New experimental methods for the production and recording of HCI spectra Identification of HCI spectra Measurement of transition lifetimes Relativistic, QED and nuclear effects in HCI spectra Polarization and angular distribution of radiation Effects of external fields on HCI spectra Tests of fundamental theories Plasma spectroscopy and spectra modeling with HCI Please submit your article by 1 December 2014 using our website http://mc04.manuscriptcentral.com/jphysb-iop. Submissions received after this date will be considered for the journal, but may not be

  9. Electron parallel closures for various ion charge numbers

    SciTech Connect

    Ji, Jeong-Young Held, Eric D.; Kim, Sang-Kyeun; Na, Yong-Su

    2016-03-15

    Electron parallel closures for the ion charge number Z = 1 [J.-Y. Ji and E. D. Held, Phys. Plasmas 21, 122116 (2014)] are extended for 1 ≤ Z ≤ 10. Parameters are computed for various Z with the same form of the Z = 1 kernels adopted. The parameters are smoothly varying in Z and hence can be used to interpolate parameters and closures for noninteger, effective ion charge numbers.

  10. HITRAP: A Facility for Experiments with Trapped Highly Charged Ions

    NASA Astrophysics Data System (ADS)

    Quint, W.; Dilling, J.; Djekic, S.; Häffner, H.; Hermanspahn, N.; Kluge, H.-J.; Marx, G.; Moore, R.; Rodriguez, D.; Schönfelder, J.; Sikler, G.; Valenzuela, T.; Verdú, J.; Weber, C.; Werth, G.

    2001-01-01

    HITRAP is a planned ion trap facility for capturing and cooling of highly charged ions produced at GSI in the heavy-ion complex of the UNILAC-SIS accelerators and the ESR storage ring. In this facility heavy highly charged ions up to uranium will be available as bare nuclei, hydrogen-like ions or few-electron systems at low temperatures. The trap for receiving and studying these ions is designed for operation at extremely high vacuum by cooling to cryogenic temperatures. The stored highly charged ions can be investigated in the trap itself or can be extracted from the trap at energies up to about 10 keV/q. The proposed physics experiments are collision studies with highly charged ions at well-defined low energies (eV/u), high-accuracy measurements to determine the g-factor of the electron bound in a hydrogen-like heavy ion and the atomic binding energies of few-electron systems, laser spectroscopy of HFS transitions and X-ray spectroscopy.

  11. High-charge energetic ions generated by intersecting laser pulses

    SciTech Connect

    Yang, L.; Deng, Z. G.; Yu, M. Y.; Wang, X. G.

    2016-08-15

    Ion acceleration from the interaction of two intersecting intense laser pulses with an overdense plasma is investigated using a three-dimensional particle-in-cell simulation. It is found that, comparing with the single-pulse case, the charge of the resulting energetic ion bunch can be increased by more than an order of magnitude without much loss of quality. Dependence of the ion charge on the interaction parameters, including separation distance and incidence angles of the lasers, is considered. It is shown that the charge of the accelerated ion bunch can be optimized by controlling the degree of laser overlapping. The improved performance can be attributed to the enhanced laser intensity as well as stochastic heating of the accelerated electrons. Since at present the intensity of readily available lasers is limited, the two pulse scheme should be useful for realizing higher laser intensity in order to achieve higher-energy target normal sheath acceleration ions.

  12. Determination of Dusty Particle Charge Taking into Account Ion Drag

    SciTech Connect

    Ramazanov, T. S.; Dosbolayev, M. K.; Jumabekov, A. N.; Amangaliyeva, R. Zh.; Orazbayev, S. A.; Petrov, O. F.; Antipov, S. N.

    2008-09-07

    This work is devoted to the experimental estimation of charge of dust particle that levitates in the stratum of dc glow discharge. Particle charge is determined on the basis of the balance between ion drag force, gravitational and electric forces. Electric force is obtained from the axial distribution of the light intensity of strata.

  13. Collision phenomena involving highly-charged ions in astronomical objects

    NASA Technical Reports Server (NTRS)

    Chutjian, A.

    2001-01-01

    A description of the role of highly charged ions in various astronomical objects; includes the use of critical quantities such as cross sections for excitation, charge-exchange, X-ray emission, radiative recombination (RR) and dielectronic recombination (DR); and lifetimes, branching ratios, and A-values.

  14. Final report: Department of Energy grant to Kansas State University - J. R. Macdonald Laboratory. Atomic physics with highly charged ions: Supplementary request for Accelerator Improvement Project

    SciTech Connect

    Richard, Patrick

    2001-12-11

    The following tasks for previous funding periods are sketched: LHe compressor relocation, LINAC RF electronics upgrade, tandem Van de Graaff foil changer; tandem Van de Graaff terminal pump installation; replace power transistors in magnet power supplies; new EBIS beam line vacuum system, EBIS beam optics upgrade, tandem Van de Graaff cryopumps, tandem upcharge system, PIG source for ion-ion system, LINAC beam line, EBIS beam optics and safety upgrade, EBIS beam power upgrade, ion-ion facility upgrade, ion-ion upgrade, new LINAC beamline, LINAC cryostat upgrade, LHe plant equipment, EBIS beamline upgrade. The task for this period, high voltage platform and ion-beam handling peripherals, is gone into in greater detail.

  15. Observation of doubly-charged ions of francium isotopes extracted from a gas cell

    NASA Astrophysics Data System (ADS)

    Schury, P.; Wada, M.; Ito, Y.; Kaji, D.; Haba, H.; Hirayama, Y.; Kimura, S.; Koura, H.; MacCormick, M.; Miyatake, H.; Moon, J. Y.; Morimoto, K.; Morita, K.; Murray, I.; Ozawa, A.; Rosenbusch, M.; Reponen, M.; Takamine, A.; Tanaka, T.; Watanabe, Y. X.; Wollnik, H.

    2017-09-01

    Various isotopes of Ac, Ra, Fr, and Rn were produced by fusion-evaporation reactions using a 48Ca beam. The energetic ions were stopped in and extracted from a helium gas cell. The extracted ions were identified using a multi-reflection time-of-fight mass spectrograph. In all cases, it was observed that the predominant charge state for the extracted ions, including the alkali Fr, was 2+.

  16. The ReA electron-beam ion trap charge breeder for reacceleration of rare isotopes

    SciTech Connect

    Lapierre, A.; Schwarz, S.; Kittimanapun, K.; Fogleman, J.; Krause, S.; Nash, S.; Rencsok, R.; Tobos, L.; Perdikakis, G.; Portillo, M.; Rodriguez, J. A.; Wittmer, W.; Wu, X.; Bollen, G.; Leitner, D.; Syphers, M.; Collaboration: ReA Team

    2013-04-19

    ReA is a post-accelerator at the National Superconducting Cyclotron Laboratory at Michigan State University. ReA is designed to reaccelerate rare isotopes to energies of a few MeV/u following production by projectile fragmentation and thermalization in a gas cell. The facility consists of four main components: an electron-beam ion trap (EBIT) charge breeder, an achromatic charge-over-mass (Q/A) separator, a radio-frequency quadrupole accelerator, and a superconducting radio-frequency linear accelerator. The EBIT charge breeder was specifically designed to efficiently capture continuous beams of singly charged ions injected at low energy (<60 keV), charge breed in less than 50 ms, and extract highly charged ions to the Q/A separator for charge-state selection and reacceleration through the accelerator structures. The use of highly charged ions to reach high beam energies is a key aspect that makes ReA a compact and cost-efficient post-accelerator. The EBIT is characterized by a high-current electron gun, a long multi-electrode trap structure and a dual magnet to provide both the high electron-beam current density necessary for fast charge breeding of short-lived isotopes as well as the high capture probability of injected beams. This paper presents an overview and the status of the ReA EBIT, which has extracted for reacceleration tests stable {sup 20}Ne{sup 8+} ion beams produced from injected gas and more recently {sup 39}K{sup 16+} beams by injecting stable {sup 39,41}K{sup +} ions from an external ion source.

  17. The ReA electron-beam ion trap charge breeder for reacceleration of rare isotopes

    NASA Astrophysics Data System (ADS)

    Lapierre, A.; Schwarz, S.; Kittimanapun, K.; Fogleman, J.; Krause, S.; Nash, S.; Rencsok, R.; Tobos, L.; Perdikakis, G.; Portillo, M.; Rodriguez, J. A.; Wittmer, W.; Wu, X.; Bollen, G.; Leitner, D.; Syphers, M.; ReA Team

    2013-04-01

    ReA is a post-accelerator at the National Superconducting Cyclotron Laboratory at Michigan State University. ReA is designed to reaccelerate rare isotopes to energies of a few MeV/u following production by projectile fragmentation and thermalization in a gas cell. The facility consists of four main components: an electron-beam ion trap (EBIT) charge breeder, an achromatic charge-over-mass (Q/A) separator, a radio-frequency quadrupole accelerator, and a superconducting radio-frequency linear accelerator. The EBIT charge breeder was specifically designed to efficiently capture continuous beams of singly charged ions injected at low energy (<60 keV), charge breed in less than 50 ms, and extract highly charged ions to the Q/A separator for charge-state selection and reacceleration through the accelerator structures. The use of highly charged ions to reach high beam energies is a key aspect that makes ReA a compact and cost-efficient post-accelerator. The EBIT is characterized by a high-current electron gun, a long multi-electrode trap structure and a dual magnet to provide both the high electron-beam current density necessary for fast charge breeding of short-lived isotopes as well as the high capture probability of injected beams. This paper presents an overview and the status of the ReA EBIT, which has extracted for reacceleration tests stable 20Ne8+ ion beams produced from injected gas and more recently 39K16+ beams by injecting stable 39,41K+ ions from an external ion source.

  18. Charge state breeding experiences and plans at TRIUMF

    SciTech Connect

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

    2016-02-15

    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.

  19. 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.

  20. Charge state breeding experiences and plans at TRIUMF.

    PubMed

    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.

  1. Tuning the Fabrication of Nanostructures by Low-Energy Highly Charged Ions.

    PubMed

    El-Said, Ayman S; Wilhelm, Richard A; Heller, Rene; Sorokin, Michael; Facsko, Stefan; Aumayr, Friedrich

    2016-09-16

    Slow highly charged ions have been utilized recently for the creation of monotype surface nanostructures (craters, calderas, or hillocks) in different materials. In the present study, we report on the ability of slow highly charged xenon ions (^{129}Xe^{Q+}) to form three different types of nanostructures on the LiF(100) surface. By increasing the charge state from Q=15 to Q=36, the shape of the impact induced nanostructures changes from craters to hillocks crossing an intermediate stage of caldera structures. A dimensional analysis of the nanostructures reveals an increase of the height up to 1.5 nm as a function of the potential energy of the incident ions. Based on the evolution of both the geometry and size of the created nanostructures, defect-mediated desorption and the development of a thermal spike are utilized as creation mechanisms of the nanostructures at low and high charge states, respectively.

  2. Charge exchange and ionization in hydrogen atom-fully stripped ion collisions in Debye plasmas

    SciTech Connect

    Zhang, H.; Wang, J. G.; He, B.; Qiu, Y. B.; Janev, R. K.

    2007-05-15

    The processes of charge exchange and ionization in collisions of ground state hydrogen atom with fully stripped ions in a weakly coupled plasma are studied by the classical trajectory Monte Carlo method in the collision energy range 10-900 keV/amu. The interparticle interactions are described by the Debye-Hueckel model with inclusion of dynamical effects associated with the projectile velocity. The microcanonical distribution of initial state electronic coordinates and momenta has been determined by inclusion of plasma screening effects. The cross section dependencies on plasma parameters and ion charge and velocity are investigated. It is shown that plasma effects on charge exchange and ionization cross sections are significant and particularly pronounced at low collision velocities. The results of systematic cross section calculations for different values of Debye screening length (in the range 1-50a{sub 0}) and ion charges (in the range 1-14) are presented.

  3. Potential and kinetic sputtering of alkanethiol self-assembled monolayers by impact of highly charged ions

    NASA Astrophysics Data System (ADS)

    Flores, M.; O'Rourke, B. E.; Yamazaki, Y.; Esaulov, V. A.

    2009-02-01

    Highly charged ions have been used to study the sputtering of positive molecular fragments from mercaptoundecanoic acid and dodecanethiol self-assembled monolayers on gold surfaces. The samples were bombarded with Arq+ (4⩽q⩽10) ions with kinetic energies from 2to18keV . The main fragments detected were H+ , CnH2n+ , and Cn+1O2H2n+1+ from mercaptoundecanoic and H+ , CnH2n+ , and Cn+1H2n+3+ from dodecanethiol. The proton yields were increased with larger charge state q of the highly charged ion (HCI) in both samples, scaling as qγ , with γ˜5 . The charge state dependence is discussed in terms of electron transfer to the HCI. The final yield of protons depends on molecular functional group characteristics, orientation on the surface, and reneutralization phenomena.

  4. Tuning the Fabrication of Nanostructures by Low-Energy Highly Charged Ions

    NASA Astrophysics Data System (ADS)

    El-Said, Ayman S.; Wilhelm, Richard A.; Heller, Rene; Sorokin, Michael; Facsko, Stefan; Aumayr, Friedrich

    2016-09-01

    Slow highly charged ions have been utilized recently for the creation of monotype surface nanostructures (craters, calderas, or hillocks) in different materials. In the present study, we report on the ability of slow highly charged xenon ions (129Xe Q+ ) to form three different types of nanostructures on the LiF(100) surface. By increasing the charge state from Q =15 to Q =36 , the shape of the impact induced nanostructures changes from craters to hillocks crossing an intermediate stage of caldera structures. A dimensional analysis of the nanostructures reveals an increase of the height up to 1.5 nm as a function of the potential energy of the incident ions. Based on the evolution of both the geometry and size of the created nanostructures, defect-mediated desorption and the development of a thermal spike are utilized as creation mechanisms of the nanostructures at low and high charge states, respectively.

  5. 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.

  6. 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.

  7. Charge Induced by Displacement of an Ion.

    ERIC Educational Resources Information Center

    Spokas, John J.

    1978-01-01

    Tries to clarify and explain some inaccuracies that appeared in a recent article dealing with a current induced in an external circuit due to charges moving within a device, an ionization chamber of planar geometry, in the circuit. (GA)

  8. Ion and water transport in charge-modified graphene nanopores

    NASA Astrophysics Data System (ADS)

    Qiu, Ying-Hua; Li, Kun; Chen, Wei-Yu; Si, Wei; Tan, Qi-Yan; Chen, Yun-Fei

    2015-10-01

    Porous graphene has a high mechanical strength and an atomic-layer thickness that makes it a promising material for material separation and biomolecule sensing. Electrostatic interactions between charges in aqueous solutions are a type of strong long-range interaction that may greatly influence fluid transport through nanopores. In this study, molecular dynamic simulations were conducted to investigate ion and water transport through 1.05-nm diameter monolayer graphene nanopores, with their edges charge-modified. Our results indicated that these nanopores are selective to counterions when they are charged. As the charge amount increases, the total ionic currents show an increase-decrease profile while the co-ion currents monotonically decrease. The co-ion rejection can reach 76.5% and 90.2% when the nanopores are negatively and positively charged, respectively. The Cl- ion current increases and reaches a plateau, and the Na+ current decreases as the charge amount increases in systems in which Na+ ions act as counterions. In addition, charge modification can enhance water transport through nanopores. This is mainly due to the ion selectivity of the nanopores. Notably, positive charges on the pore edges facilitate water transport much more strongly than negative charges. Project supported by the National Basic Research Program of China (Grant Nos. 2011CB707601 and 2011CB707605), the National Natural Science Foundation of China (Grant No. 50925519), the Fundamental Research Funds for the Central Universities, Funding of Jiangsu Provincial Innovation Program for Graduate Education, China (Grant No. CXZZ13_0087), and the Scientific Research Foundation of Graduate School of Southeast University (Grant No. YBJJ 1322).

  9. Damage in graphene due to electronic excitation induced by highly charged ions

    NASA Astrophysics Data System (ADS)

    Hopster, J.; Kozubek, R.; Ban-d'Etat, B.; Guillous, S.; Lebius, H.; Schleberger, M.

    2014-06-01

    Graphene is expected to be rather insensitive to ion irradiation. We demonstrate that single layers of exfoliated graphene sustain significant damage from irradiation with slow highly charged ions. We have investigated the ion induced changes of graphene after irradiation with highly charged ions of different charge states (q = 28-42) and kinetic energies ({{E}_{\\text{kin}}} = 150-450 keV). Atomic force microscopy images reveal that the ion induced defects are not topographic in nature but are related to a significant change in friction. To create these defects, a minimum charge state is needed. In addition to this threshold behaviour, the required minimum charge state as well as the defect diameter show a strong dependency on the kinetic energy of the projectiles. From the linear dependency of the defect diameter on the projectile velocity we infer that electronic excitations triggered by the incoming ion in the above-surface phase play a dominant role for this unexpected defect creation in graphene.

  10. A compact source for bunches of singly charged atomic ions

    NASA Astrophysics Data System (ADS)

    Murböck, T.; Schmidt, S.; Andelkovic, Z.; Birkl, G.; Nörtershäuser, W.; Vogel, M.

    2016-04-01

    We have built, operated, and characterized a compact ion source for low-energy bunches of singly charged atomic ions in a vacuum beam line. It is based on atomic evaporation from an electrically heated oven and ionization by electron impact from a heated filament inside a grid-based ionization volume. An adjacent electrode arrangement is used for ion extraction and focusing by applying positive high-voltage pulses to the grid. The method is particularly suited for experimental environments which require low electromagnetic noise. It has proven simple yet reliable and has been used to produce μs-bunches of up to 106 Mg+ ions at a repetition rate of 1 Hz. We present the concept, setup and characterizing measurements. The instrument has been operated in the framework of the SpecTrap experiment at the HITRAP facility at GSI/FAIR to provide Mg+ ions for sympathetic cooling of highly charged ions by laser-cooled 24Mg+.

  11. New State of Nuclear Matter: Nearly Perfect Fluid of Quarks and Gluons in Heavy Ion Collisions at RHIC Energies From Charged Particle Density to Jet Quenching

    SciTech Connect

    Nouicer, R.

    2016-03-28

    This article reviews several important results from RHIC experiments and discusses their implications. They were obtained in a unique environment for studying QCD matter at temperatures and densities that exceed the limits wherein hadrons can exist as individual entities and raises to prominence the quark-gluon degrees of freedom. These findings are supported by major experimental observations via measuring of the bulk properties of particle production, particle ratios and chemical freeze-out conditions, and elliptic ow; followed by hard probe measurements: high-pT hadron suppression, dijet fragment azimuthal correlations, and heavy favor probes. These measurements are presented for particles of different species as a function of system sizes, collision centrality, and energy carried out in RHIC experiments. The results reveal that a dense, strongly-interacting medium is created in central Au + Au collisions at p sNN = 200 GeV at RHIC. This revelation of a new state of nuclear matter has also been observed in measurements at the LHC. Further, the IP-Glasma model coupled with viscous hydrodynamic models, which assumes the formation of a QGP, reproduces well the experimental ow results from Au + Au at p sNN = 200 GeV. This implies that the fluctuations in the initial geometry state are important and the created medium behaves as a nearly perfect liquid of nuclear matter because it has an extraordinarily low ratio of shear viscosity to entropy density, =s 0.12. However, these discoveries are far from being fully understood. Furthermore, recent experimental results from RHIC and LHC in small p + A, d + Au and 3He+Au collision systems provide brand new insight into the role of initial and final state effects. These have proven to be interesting and more surprising than originally anticipated; and could conceivably shed new light in our understanding of collective behavior in heavy-ion physics. Accordingly, the focus of the experiments at both facilities RHIC and the LHC

  12. New State of Nuclear Matter: Nearly Perfect Fluid of Quarks and Gluons in Heavy Ion Collisions at RHIC Energies From Charged Particle Density to Jet Quenching

    DOE PAGES

    Nouicer, R.

    2016-03-28

    This article reviews several important results from RHIC experiments and discusses their implications. They were obtained in a unique environment for studying QCD matter at temperatures and densities that exceed the limits wherein hadrons can exist as individual entities and raises to prominence the quark-gluon degrees of freedom. These findings are supported by major experimental observations via measuring of the bulk properties of particle production, particle ratios and chemical freeze-out conditions, and elliptic ow; followed by hard probe measurements: high-pT hadron suppression, dijet fragment azimuthal correlations, and heavy favor probes. These measurements are presented for particles of different species asmore » a function of system sizes, collision centrality, and energy carried out in RHIC experiments. The results reveal that a dense, strongly-interacting medium is created in central Au + Au collisions at p sNN = 200 GeV at RHIC. This revelation of a new state of nuclear matter has also been observed in measurements at the LHC. Further, the IP-Glasma model coupled with viscous hydrodynamic models, which assumes the formation of a QGP, reproduces well the experimental ow results from Au + Au at p sNN = 200 GeV. This implies that the fluctuations in the initial geometry state are important and the created medium behaves as a nearly perfect liquid of nuclear matter because it has an extraordinarily low ratio of shear viscosity to entropy density, =s 0.12. However, these discoveries are far from being fully understood. Furthermore, recent experimental results from RHIC and LHC in small p + A, d + Au and 3He+Au collision systems provide brand new insight into the role of initial and final state effects. These have proven to be interesting and more surprising than originally anticipated; and could conceivably shed new light in our understanding of collective behavior in heavy-ion physics. Accordingly, the focus of the experiments at both facilities RHIC and

  13. New state of nuclear matter: Nearly perfect fluid of quarks and gluons in heavy-ion collisions at RHIC energies. From charged particle density to jet quenching

    NASA Astrophysics Data System (ADS)

    Nouicer, R.

    2016-03-01

    This article reviews several important results from RHIC experiments and discusses their implications. They were obtained in a unique environment for studying QCD matter at temperatures and densities that exceed the limits wherein hadrons can exist as individual entities and raises to prominence the quark-gluon degrees of freedom. These findings are supported by major experimental observations via measuring of the bulk properties of particle production, particle ratios and chemical freeze-out conditions, and elliptic flow; followed by hard probe measurements: high- pT hadron suppression, dijet fragment azimuthal correlations, and heavy-flavor probes. These measurements are presented for particles of different species as a function of system sizes, collision centrality, and energy carried out in RHIC experiments. The results reveal that a dense, strongly interacting medium is created in central Au+Au collisions at sqrt{s_{NN}} = 200 GeV at RHIC. This revelation of a new state of nuclear matter has also been observed in measurements at the LHC. Further, the IP-Glasma model coupled with viscous hydrodynamic models, which assumes the formation of a QGP, reproduces well the experimental flow results from Au+Au at sqrt{s_{NN}} = 200 GeV. This implies that the fluctuations in the initial geometry state are important and the created medium behaves as a nearly perfect liquid of nuclear matter because it has an extraordinarily low ratio of shear viscosity to entropy density, η/s≈ 0.12. However, these discoveries are far from being fully understood. Furthermore, recent experimental results from RHIC and LHC in small p+A, d+ Au and 3He+Au collision systems provide brand new insight into the role of initial and final state effects. These have proven to be interesting and more surprising than originally anticipated; and could conceivably shed new light in our understanding of collective behavior in heavy-ion physics. Accordingly, the focus of the experiments at both

  14. Intense beam production of highly charged heavy ions by the superconducting electron cyclotron resonance ion source SECRAL.

    PubMed

    Zhao, H W; Sun, L T; Zhang, X Z; Guo, X H; Cao, Y; Lu, W; Zhang, Z M; Yuan, P; Song, M T; Zhao, H Y; Jin, T; Shang, Y; Zhan, W L; Wei, B W; Xie, D Z

    2008-02-01

    There has been increasing demand to provide higher beam intensity and high enough beam energy for heavy ion accelerator and some other applications, which has driven electron cyclotron resonance (ECR) ion source to produce higher charge state ions with higher beam intensity. One of development trends for highly charged ECR ion source is to build new generation ECR sources by utilization of superconducting magnet technology. SECRAL (superconducting ECR ion source with advanced design in Lanzhou) was successfully built to produce intense beams of highly charged ion for Heavy Ion Research Facility in Lanzhou (HIRFL). The ion source has been optimized to be operated at 28 GHz for its maximum performance. The superconducting magnet confinement configuration of the ion source consists of three axial solenoid coils and six sextupole coils with a cold iron structure as field booster and clamping. An innovative design of SECRAL is that the three axial solenoid coils are located inside of the sextupole bore in order to reduce the interaction forces between the sextupole coils and the solenoid coils. For 28 GHz operation, the magnet assembly can produce peak mirror fields on axis of 3.6 T at injection, 2.2 T at extraction, and a radial sextupole field of 2.0 T at plasma chamber wall. During the commissioning phase at 18 GHz with a stainless steel chamber, tests with various gases and some metals have been conducted with microwave power less than 3.5 kW by two 18 GHz rf generators. It demonstrates the performance is very promising. Some record ion beam intensities have been produced, for instance, 810 e microA of O(7+), 505 e microA of Xe(20+), 306 e microA of Xe(27+), and so on. The effect of the magnetic field configuration on the ion source performance has been studied experimentally. SECRAL has been put into operation to provide highly charged ion beams for HIRFL facility since May 2007.

  15. Stopping power of charged particles due to ion wave excitations.

    PubMed

    Nitta, H; Muroki, C; Nambu, M

    2002-08-01

    Stopping power due to ion wave excitations is derived for a charged particle moving in a two-component plasma. Unlike previous theories based on ion-acoustic-wave approximation (IAWA), the excitation of short-wavelength ion waves is taken into account. The obtained stopping power has a magnitude larger than that of IAWA. Stopping power at subsonic velocities, where stopping power in IAWA disappears, is even larger than that of supersonic velocities.

  16. Stopping power of charged particles due to ion wave excitations

    NASA Astrophysics Data System (ADS)

    Nitta, H.; Muroki, C.; Nambu, M.

    2002-08-01

    Stopping power due to ion wave excitations is derived for a charged particle moving in a two-component plasma. Unlike previous theories based on ion-acoustic-wave approximation (IAWA), the excitation of short-wavelength ion waves is taken into account. The obtained stopping power has a magnitude larger than that of IAWA. Stopping power at subsonic velocities, where stopping power in IAWA disappears, is even larger than that of supersonic velocities.

  17. Characterization of the internal ion environment of biofilms based on charge density and shape of ion.

    PubMed

    Kurniawan, Andi; Tsuchiya, Yuki; Eda, Shima; Morisaki, Hisao

    2015-12-01

    Biofilm polymers contain both electrically positively and negatively charged sites. These charged sites enable the biofilm to trap and retain ions leading to an important role of biofilm such as nutrient recycling and pollutant purification. Much work has focused on the ion-exchange capacity of biofilms, and they are known to adsorb ions through an exchange mechanism between the ions in solution and the ions adsorbed to the charged sites on the biofilm polymer. However, recent studies suggest that the adsorption/desorption behavior of ions in a biofilm cannot be explained solely by this ion exchange mechanism. To examine the possibility that a substantial amount of ions are held in the interstitial region of the biofilm polymer by an electrostatic interaction, intact biofilms formed in a natural environment were immersed in distilled water and ion desorption was investigated. All of the detected ion species were released from the biofilms over a short period of time, and very few ions were subsequently released over more time, indicating that the interstitial region of biofilm polymers is another ion reserve. The extent of ion retention in the interstitial region of biofilms for each ion can be determined largely by charge density, |Z|/r, where |Z| is the ion valence as absolute value and r is the ion radius. The higher |Z|/r value an ion has, the stronger it is retained in the interstitial region of biofilms. Ion shape is also a key determinant of ion retention. Spherical and non-spherical ions have different correlations between the condensation ratio and |Z|/r. The generality of these findings were assured by various biofilm samples. Thus, the internal regions of biofilms exchange ions dynamically with the outside environment.

  18. Investigation of charge balance in ion accelerator TEMP-4M

    NASA Astrophysics Data System (ADS)

    Khailov, I. P.; Pak, V. G.

    2014-10-01

    The paper presents the results of a study on the balance of charge in accelerator TEMP-4M operating in double-pulse mode with resistance load and ion diode. Crucially, it was found, that during the switching there is no losses of accumulated charge. It means, that all accumulated charge transferred to the load. However when the charge is transferred from the Marx generator to Blumlein line the half of accumulated charge is lost. Calibration of diagnostic equipment showed a good agreement between the calculated and experimental values of voltage and current. It means, that our diagnostic system is correct for registration parameters of the ion accelerator. A distinctive feature of the ion accelerators with self-magnetically insulated diode is that there is no need to use additional energy source for the creation of an external magnetic field. That's why the efficiency of ion diodes with an external magnetic field is not more than 10-15%. The efficiency of energy conversion in self-magnetically insulated diodes will be determined by not only the efficiency of the diode, but the energy losses in the units of the accelerator. The aim of the researches is the analysis of the balance of charge in units of the ion beams pulsed generator and definition of the most significant channels of energy loss.

  19. Charge Retention by Monodisperse Gold Clusters on Surfaces Prepared Using Soft Landing of Mass Selected Ions

    NASA Astrophysics Data System (ADS)

    Johnson, Grant; Priest, Thomas; Laskin, Julia

    2012-02-01

    Monodisperse gold clusters have been prepared on surfaces in different charge states through soft landing of mass-selected ions. Gold clusters were synthesized in methanol solution by reduction of a gold precursor with a weak reducing agent in the presence of a diphosphine capping ligand. Electrospray ionization was used to introduce the clusters into the gas-phase and mass-selection was employed to isolate a single ionic cluster species which was delivered to surfaces at well controlled kinetic energies. Using in-situ time of flight secondary ion mass spectrometry (SIMS) it is demonstrated that the cluster retains its 3+ charge state when soft landed onto the surface of a fluorinated self assembled monolayer on gold. In contrast, when deposited onto carboxylic acid terminated and conventional alkyl thiol surfaces on gold the clusters exhibit larger relative abundances of the 2+ and 1+ charge states, respectively. The kinetics of charge reduction on the surface have been investigated using in-situ Fourier Transform Ion Cyclotron Resonance SIMS. It is shown that an extremely slow interfacial charge reduction occurs on the fluorinated monolayer surface while an almost instantaneous neutralization takes place on the surface of the alkyl thiol monolayer. Our results demonstrate that the size and charge state of small gold clusters on surfaces, both of which exert a dramatic influence on their chemical and physical properties, may be tuned through soft landing of mass-selected ions onto selected substrates.

  20. Ion-based materials comprising planar charged species.

    PubMed

    Dong, Bin; Maeda, Hiromitsu

    2013-05-14

    Materials comprising planar units have the propensity to form stacking assemblies with nanoscale architectures and intriguing properties. In this feature article, some recent examples of ion-based materials comprising positively and negatively charged planar species are described. Various ion-based solid and soft materials can be formed by planar charged species alone or with the aid of other components. It is more challenging to prepare planar anions than planar cations; however, the noncovalent association of electronically neutral planar anion receptors and anions is an efficient strategy for the preparation of planar anions. Suitable candidates include dipyrrolyldiketone boron complexes, which exhibit the formation of various receptor-anion complexes and can be used to fabricate advanced materials in combination with countercations. Ion-based materials consisting of planar charged components have potential as electrically conductive materials, resulting from the ordered arrangement of the planar charged species.

  1. Progress in collisions of multiply charged ions

    SciTech Connect

    Phaneuf, R.A.

    1991-01-01

    The increasing power and availability of supercomputers during the last decade led to significant progress in the theory of multicharged ion interactions. However, important tests of many theoretical predictions were lacking, and have become possible only quite recently as new capabilities have been realized in the laboratory. This paper broadly surveys some of these experimental developments, and their impact on our understanding of collisional interactions of multicharged ions. The scope is limited to measurements made with monoenergetic beams. 35 refs., 6 figs.

  2. Penning-trap experiments for spectroscopy of highly-charged ions at HITRAP

    NASA Astrophysics Data System (ADS)

    Vogel, M.; Andelkovic, Z.; Birkl, G.; Ebrahimi, S.; Hannen, V.; von Lindenfels, D.; Martin, A.; Murböck, T.; Nörtershäuser, W.; Quint, W.; Schmidt, S.; Segal, D. M.; Thompson, R. C.; Vollbrecht, J.; Weinheimer, Ch; Wiesel, M.

    2015-11-01

    Highly charged ions offer the possibility to measure electronic fine structures and hyperfine structures with precisions of optical lasers. Microwave spectroscopy of transitions between Zeeman substates further yields magnetic moments (g-factors) of bound electrons, making tests of calculations in the framework of bound-state QED possible in the strong-field regime. We present the SPECTRAP and ARTEMIS experiments, which are currently being commissioned with highly charged ions in the framework of the HITRAP facility at GSI, Germany. We present the scientific outline, the experimental setups and first results with confined ions.

  3. Optimal charging profiles for mechanically constrained lithium-ion batteries

    SciTech Connect

    Suthar, B; Ramadesigan, V; De, S; Braatz, RD; Subramanian, VR

    2014-01-01

    The cost and safety related issues of lithium-ion batteries require intelligent charging profiles that can efficiently utilize the battery. This paper illustrates the application of dynamic optimization in obtaining the optimal current profile for charging a lithium-ion battery using a single-particle model while incorporating intercalation-induced stress generation. In this paper, we focus on the problem of maximizing the charge stored in a given time while restricting the development of stresses inside the particle. Conventional charging profiles for lithium-ion batteries (e.g., constant current followed by constant voltage) were not derived by considering capacity fade mechanisms. These charging profiles are not only inefficient in terms of lifetime usage of the batteries but are also slower since they do not exploit the changing dynamics of the system. Dynamic optimization based approaches have been used to derive optimal charging and discharging profiles with different objective functions. The progress made in understanding the capacity fade mechanisms has paved the way for inclusion of that knowledge in deriving optimal controls. While past efforts included thermal constraints, this paper for the first time presents strategies for optimally charging batteries by guaranteeing minimal mechanical damage to the electrode particles during intercalation. In addition, an executable form of the code has been developed and provided. This code can be used to identify optimal charging profiles for any material and design parameters.

  4. EXAFS study of dopant ions with different charges in nanocrystalline anatase: evidence for space-charge segregation of acceptor ions.

    PubMed

    Knauth, Philippe; Chadwick, Alan V; Lippens, Pierre E; Auer, Gerhard

    2009-06-02

    Nanocrystalline TiO(2) (anatase) is an essential oxide for environment and energy applications. A combination of EXAFS spectroscopy and DFT calculations on a series of dopants with quite similar ion radius, but increasing ion charge, show boundary space charge segregation of acceptor cations. The picture illustrates the Fourier-transformed EXAFS spectrum for Sn(4+)-doped TiO(2).A series of dopants, including acceptor ions (Zn(2+), Y(3+)), isovalent ions (Zr(4+), Sn(4+)) as well as a donor ion (Nb(5+)), were studied by EXAFS spectroscopy in nanocrystalline TiO(2) anatase powders and nanoceramics. Similar results were found for nanocrystalline powders and nanocrystalline ceramics, made by hot-pressing the powders. Boundary segregation was observed for the acceptor ions yttrium and zinc, whereas tin, zirconium and niobium ions were placed on substitutional bulk sites and did not segregate, whatever their concentration. These results can be interpreted based on defect thermodynamics, in the framework of a space charge segregation model with positive boundary core, due to excess oxide ion vacancies, and negative space charge regions, where ionized acceptors are segregated.

  5. Influence of Ion Field Emission on the Dust Charge

    NASA Astrophysics Data System (ADS)

    Pavlu, J.; Richterova, I.; Safrankova, J.; Nemecek, Z.

    2005-12-01

    In the interplanetary space where the dominant process charging the dust immersed in the tenuous ambient plasma is photoelectron current, the grains collect a positive charge. This charge can be further enhanced by impacts of the energetic ions. The attainable charge is limited by the ion field emission. However, the ion field emission is a term generally used for three different processes: Field ionization, field desorption, and field evaporation. First of them can be of interest under laboratory conditions but negligible in the interplanetary space because the surrounding gas is often fully ionized. Field desorption can be important but under particular circumstances, e.g., for dust grains freshly released from larger objects (like comets) because the grains are bombarded by energetic particles that rapidly clean-up their surfaces. On the other hand, the field evaporating dust grains may be important sources of heavy ions in the space. There is an observational evidence of pickup ions in the solar wind and the field emission of dust grain material was suggested to be responsible for the production of these ions. For these reasons, the knowledge of basic characteristics of the ion field emission from the dust grains is significant for understanding of the plasma processes in the space. The present study deals with the ion field emission from highly charged spherical samples form a MF resin (alternatively covered by a thin layer of Ni) and Au. The samples were charged by the ion beam of various energies up to 5 keV. Investigations of spontaneous grain discharging allow us to suggest that the field desorption (together with post-ionization) is the main process responsible for observed gradual discharging of used metallic grain samples. However, the grain charge is accumulated in a thick surface layer of non-conducting samples. The thickness of this layer depends on the mass and energy of primary ions. We can thus conclude that the charging history (mass and energy

  6. Fast and efficient charge breeding of the Californium rare isotope breeder upgrade electron beam ion source

    NASA Astrophysics Data System (ADS)

    Ostroumov, P. N.; Barcikowski, A.; Dickerson, C. A.; Perry, A.; Pikin, A. I.; Sharamentov, S. I.; Vondrasek, R. C.; Zinkann, G. P.

    2015-08-01

    The Electron Beam Ion Source (EBIS), developed to breed Californium Rare Isotope Breeder Upgrade (CARIBU) radioactive beams at Argonne Tandem Linac Accelerator System (ATLAS), is being tested off-line. A unique property of the EBIS is a combination of short breeding times, high repetition rates, and a large acceptance. Overall, we have implemented many innovative features during the design and construction of the CARIBU EBIS as compared to the existing EBIS breeders. The off-line charge breeding tests are being performed using a surface ionization source that produces singly charged cesium ions. The main goal of the off-line commissioning is to demonstrate stable operation of the EBIS at a 10 Hz repetition rate and a breeding efficiency into single charge state higher than 15%. These goals have been successfully achieved and exceeded. We have measured (20% ± 0.7%) breeding efficiency into the single charge state of 28+ cesium ions with the breeding time of 28 ms. In general, the current CARIBU EBIS operational parameters can provide charge breeding of any ions in the full mass range of periodic table with high efficiency, short breeding times, and sufficiently low charge-to-mass ratio, 1/6.3 for the heaviest masses, for further acceleration in ATLAS. In this paper, we discuss the parameters of the EBIS and the charge breeding results in a pulsed injection mode with repetition rates up to 10 Hz.

  7. Fast and efficient charge breeding of the Californium rare isotope breeder upgrade electron beam ion source.

    PubMed

    Ostroumov, P N; Barcikowski, A; Dickerson, C A; Perry, A; Pikin, A I; Sharamentov, S I; Vondrasek, R C; Zinkann, G P

    2015-08-01

    The Electron Beam Ion Source (EBIS), developed to breed Californium Rare Isotope Breeder Upgrade (CARIBU) radioactive beams at Argonne Tandem Linac Accelerator System (ATLAS), is being tested off-line. A unique property of the EBIS is a combination of short breeding times, high repetition rates, and a large acceptance. Overall, we have implemented many innovative features during the design and construction of the CARIBU EBIS as compared to the existing EBIS breeders. The off-line charge breeding tests are being performed using a surface ionization source that produces singly charged cesium ions. The main goal of the off-line commissioning is to demonstrate stable operation of the EBIS at a 10 Hz repetition rate and a breeding efficiency into single charge state higher than 15%. These goals have been successfully achieved and exceeded. We have measured (20% ± 0.7%) breeding efficiency into the single charge state of 28+ cesium ions with the breeding time of 28 ms. In general, the current CARIBU EBIS operational parameters can provide charge breeding of any ions in the full mass range of periodic table with high efficiency, short breeding times, and sufficiently low charge-to-mass ratio, 1/6.3 for the heaviest masses, for further acceleration in ATLAS. In this paper, we discuss the parameters of the EBIS and the charge breeding results in a pulsed injection mode with repetition rates up to 10 Hz.

  8. Fast and efficient charge breeding of the Californium rare isotope breeder upgrade electron beam ion source

    DOE PAGES

    Ostroumov, P. N.; Barcikowski, A.; Dickerson, C. A.; ...

    2015-08-28

    The Electron Beam Ion Source (EBIS), developed to breed Californium Rare Isotope Breeder Upgrade (CARIBU) radioactive beams at Argonne Tandem Linac Accelerator System (ATLAS), is being tested off-line. A unique property of the EBIS is a combination of short breeding times, high repetition rates, and a large acceptance. Overall, we have implemented many innovative features during the design and construction of the CARIBU EBIS as compared to the existing EBIS breeders. The off-line charge breeding tests are being performed using a surface ionization source that produces singly charged cesium ions. The main goal of the off-line commissioning is to demonstratemore » stable operation of the EBIS at a 10 Hz repetition rate and a breeding efficiency into single charge state higher than 15%. These goals have been successfully achieved and exceeded. We have measured (20% ± 0.7%) breeding efficiency into the single charge state of 28+ cesium ions with the breeding time of 28 ms. In general, the current CARIBU EBIS operational parameters can provide charge breeding of any ions in the full mass range of periodic table with high efficiency, short breeding times, and sufficiently low charge-to-mass ratio, 1/6.3 for the heaviest masses, for further acceleration in ATLAS. In this study, we discuss the parameters of the EBIS and the charge breeding results in a pulsed injection mode with repetition rates up to 10 Hz.« less

  9. Fast and efficient charge breeding of the Californium rare isotope breeder upgrade electron beam ion source

    SciTech Connect

    Ostroumov, P. N. Barcikowski, A.; Dickerson, C. A.; Perry, A.; Sharamentov, S. I.; Vondrasek, R. C.; Zinkann, G. P.; Pikin, A. I.

    2015-08-15

    The Electron Beam Ion Source (EBIS), developed to breed Californium Rare Isotope Breeder Upgrade (CARIBU) radioactive beams at Argonne Tandem Linac Accelerator System (ATLAS), is being tested off-line. A unique property of the EBIS is a combination of short breeding times, high repetition rates, and a large acceptance. Overall, we have implemented many innovative features during the design and construction of the CARIBU EBIS as compared to the existing EBIS breeders. The off-line charge breeding tests are being performed using a surface ionization source that produces singly charged cesium ions. The main goal of the off-line commissioning is to demonstrate stable operation of the EBIS at a 10 Hz repetition rate and a breeding efficiency into single charge state higher than 15%. These goals have been successfully achieved and exceeded. We have measured (20% ± 0.7%) breeding efficiency into the single charge state of 28+ cesium ions with the breeding time of 28 ms. In general, the current CARIBU EBIS operational parameters can provide charge breeding of any ions in the full mass range of periodic table with high efficiency, short breeding times, and sufficiently low charge-to-mass ratio, 1/6.3 for the heaviest masses, for further acceleration in ATLAS. In this paper, we discuss the parameters of the EBIS and the charge breeding results in a pulsed injection mode with repetition rates up to 10 Hz.

  10. Fast and efficient charge breeding of the Californium rare isotope breeder upgrade electron beam ion source

    SciTech Connect

    Ostroumov, P. N.; Barcikowski, A.; Dickerson, C. A.; Perry, A.; Pikin, A. I.; Sharamentov, S. I.; Vondrasek, R. C.; Zinkann, G. P.

    2015-08-28

    The Electron Beam Ion Source (EBIS), developed to breed Californium Rare Isotope Breeder Upgrade (CARIBU) radioactive beams at Argonne Tandem Linac Accelerator System (ATLAS), is being tested off-line. A unique property of the EBIS is a combination of short breeding times, high repetition rates, and a large acceptance. Overall, we have implemented many innovative features during the design and construction of the CARIBU EBIS as compared to the existing EBIS breeders. The off-line charge breeding tests are being performed using a surface ionization source that produces singly charged cesium ions. The main goal of the off-line commissioning is to demonstrate stable operation of the EBIS at a 10 Hz repetition rate and a breeding efficiency into single charge state higher than 15%. These goals have been successfully achieved and exceeded. We have measured (20% ± 0.7%) breeding efficiency into the single charge state of 28+ cesium ions with the breeding time of 28 ms. In general, the current CARIBU EBIS operational parameters can provide charge breeding of any ions in the full mass range of periodic table with high efficiency, short breeding times, and sufficiently low charge-to-mass ratio, 1/6.3 for the heaviest masses, for further acceleration in ATLAS. In this study, we discuss the parameters of the EBIS and the charge breeding results in a pulsed injection mode with repetition rates up to 10 Hz.

  11. Velocity and ion charge in a copper plasma plume ejected from 5 microsecond vacuum arcs

    NASA Astrophysics Data System (ADS)

    Silver, Y.; Nachshon, I.; Beilis, I. I.; Leibovitch, G.; Shafir, G.

    2017-02-01

    The charge state and velocity of ions extracted from the expanding plasma of 5 μs vacuum arc were measured using a Time of Flight mass spectrometer. The arc was sustained between the cylindrical copper cathode of 1 mm diameter and Kovar cylindrical anode. The distance between the two electrodes is 0.1 mm. The ion charge state and velocity were detected after the arc pulse at different times (in range 20-45 μs) by opening an electronic shutter. The arc current was 35 A. It was obtained that the ion velocities are decreasing with detection times from 3.75 to 1.75 cm/μs. The fastest ions are made of a large fraction of Cu+3 with some Cu+2 while the slowest ions are made of a larger fraction of Cu+2 with some Cu+.

  12. 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.

  13. 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.

  14. 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.

  15. Ion transport through macrocapillaries - Oscillations due to charge patch formation

    NASA Astrophysics Data System (ADS)

    Kulkarni, D. D.; Lyle, L. A. M.; Sosolik, C. E.

    2016-09-01

    We present results on ion transport through large bore capillaries (macrocapillaries) that probe both the geometric and ion-guided aspects of this ion delivery mechanism. We have demonstrated that guiding in macrocapillaries exhibits position- and angle-dependent transmission properties which are directly related to the capillary material (either metal or insulator) and geometry. Specifically, we have passed 1 keV Rb+ ions through glass and metal macrocapillaries, and have observed oscillations for the transmitted ion current passing through the insulating capillaries. Straightforward calculations show that these oscillations can be attributed to beam deflections from charge patches that form on the interior walls of the capillary. The absence of these oscillations in the metal capillary data serve as further confirmation of the role of charge patch formation.

  16. Multiple electron capture from isolated protein poly-anions in collision with slow highly charged ions.

    PubMed

    Milosavljević, A R; Rousseau, P; Domaracka, A; Huber, B A; Giuliani, A

    2017-08-02

    Collisions of 375 keV Xe(25+) ions with trapped mass/charge selected poly-anions of the cytochrome C protein (∼12.5 kDa) were studied by coupling a linear quadrupole ion trap with low-energy ion beam facility. Tandem mass spectra were recorded for the protein precursor charge states ranging from -9 to -17. The present work reports the first study of slow highly charged ion collisions with poly-anions. A high signal to noise ratio allowed the study of the intensity of single and multiple electron removal by a projectile, as well as associated neutral losses, as a function of the target charge state. Relative single and double electron detachment cross sections were found to increase with increasing charge state of the precursor anion. The experimental findings are supported by the calculations of the total electron capture cross sections, based on the classical over-the-barrier model, restricted to a simple uniformly charged linear protein structure and a near-end electron capture.

  17. Study on space charge compensation in negative hydrogen ion beam.

    PubMed

    Zhang, A L; Peng, S X; Ren, H T; Zhang, T; Zhang, J F; Xu, Y; Guo, Z Y; Chen, J E

    2016-02-01

    Negative hydrogen ion beam can be compensated by the trapping of ions into the beam potential. When the beam propagates through a neutral gas, these ions arise due to gas ionization by the beam ions. However, the high neutral gas pressure may cause serious negative hydrogen ion beam loss, while low neutral gas pressure may lead to ion-ion instability and decompensation. To better understand the space charge compensation processes within a negative hydrogen beam, experimental study and numerical simulation were carried out at Peking University (PKU). The simulation code for negative hydrogen ion beam is improved from a 2D particle-in-cell-Monte Carlo collision code which has been successfully applied to H(+) beam compensated with Ar gas. Impacts among ions, electrons, and neutral gases in negative hydrogen beam compensation processes are carefully treated. The results of the beam simulations were compared with current and emittance measurements of an H(-) beam from a 2.45 GHz microwave driven H(-) ion source in PKU. Compensation gas was injected directly into the beam transport region to modify the space charge compensation degree. The experimental results were in good agreement with the simulation results.

  18. Study on space charge compensation in negative hydrogen ion beam

    SciTech Connect

    Zhang, A. L.; Chen, J. E.; Peng, S. X. Ren, H. T.; Zhang, T.; Zhang, J. F.; Xu, Y.; Guo, Z. Y.

    2016-02-15

    Negative hydrogen ion beam can be compensated by the trapping of ions into the beam potential. When the beam propagates through a neutral gas, these ions arise due to gas ionization by the beam ions. However, the high neutral gas pressure may cause serious negative hydrogen ion beam loss, while low neutral gas pressure may lead to ion-ion instability and decompensation. To better understand the space charge compensation processes within a negative hydrogen beam, experimental study and numerical simulation were carried out at Peking University (PKU). The simulation code for negative hydrogen ion beam is improved from a 2D particle-in-cell-Monte Carlo collision code which has been successfully applied to H{sup +} beam compensated with Ar gas. Impacts among ions, electrons, and neutral gases in negative hydrogen beam compensation processes are carefully treated. The results of the beam simulations were compared with current and emittance measurements of an H{sup −} beam from a 2.45 GHz microwave driven H{sup −} ion source in PKU. Compensation gas was injected directly into the beam transport region to modify the space charge compensation degree. The experimental results were in good agreement with the simulation results.

  19. Magnetic piston model for higher ion charge and different electron and ion plasma temperatures

    SciTech Connect

    Bogatu, I. N.

    2013-05-15

    A new formula for the magnetic piston model, which explicitly describes how the momentum imparted to the ions by the magnetic pressure depends not only on the ion mass but also on the ion charge, as well as, on the plasma electron and ion temperatures, is derived following Rosenbluth's classical particle-field self-consistent plane approximation analytic calculation. The formula presented in this paper has implications in explaining the experimentally observed separation of the ions of different species and charges by the magnetic field penetrating the plasma and specularly reflecting them.

  20. Dynamics of guiding highly charged ions through SiO{sub 2} nanocapillaries

    SciTech Connect

    Zhang, H.-Q.; Skog, P.; Schuch, R.

    2010-11-15

    The time evolution of angular distributions of 7-keV Ne{sup 7+} ions transmitted through SiO{sub 2} nanocapillaries is studied starting with already-charged capillaries, as well as with fully discharged capillaries, under well-defined conditions. We deduce the rearrangement of charge patches for the charged capillaries from the time evolution of the angular distributions. The rearrangement time is found to be orders of magnitude shorter than the discharge time. Combined with a model calculation, we derive quantitative information on the formation of charge patches downstream of the entrance patch during charging-up, starting with the fully discharged capillaries. A pattern of a small number of charge patches guiding ions is deduced in the stationary state of transmission. The model predicts the width and broadening of the transmitted intensity in accord with measurements. We find strong evidence that the deposited charge patches, formed during charge-up, remain localized in the steady state of ion transmission.

  1. Threshold and efficiency for perforation of 1 nm thick carbon nanomembranes with slow highly charged ions

    NASA Astrophysics Data System (ADS)

    Wilhelm, Richard A.; Gruber, Elisabeth; Ritter, Robert; Heller, René; Beyer, André; Turchanin, Andrey; Klingner, Nico; Hübner, René; Stöger-Pollach, Michael; Vieker, Henning; Hlawacek, Gregor; Gölzhäuser, Armin; Facsko, Stefan; Aumayr, Friedrich

    2015-09-01

    Cross-linking of a self-assembled monolayer of 1,1‧-biphenyl-4-thiol by low energy electron irradiation leads to the formation of a carbon nanomembrane, that is only 1 nm thick. Here we study the perforation of these freestanding membranes by slow highly charged ion irradiation with respect to the pore formation yield. It is found that a threshold in potential energy of the highly charged ions of about 10 keV must be exceeded in order to form round pores with tunable diameters in the range of 5-15 nm. Above this energy threshold, the efficiency for a single ion to form a pore increases from 70% to nearly 100% with increasing charge. These findings are verified by two independent methods, namely the analysis of individual membranes stacked together during irradiation and the detailed analysis of exit charge state spectra utilizing an electrostatic analyzer.

  2. Cluster-assisted multiple-ionization of methyl iodide by a nanosecond laser: Wavelength dependence of multiple-charge ions

    NASA Astrophysics Data System (ADS)

    Wang, Weiguo; Li, Haiyang; Niu, Dongmei; Wen, Lihua; Zhang, Nazhen

    2008-09-01

    As efforts continue to elucidate laser-cluster interactions, we investigated the influence of laser wavelength on ion products. In this study, a pulsed methyl iodide cluster was irradiated with a Nd-YAG nanosecond laser, and the ion products were analyzed using time-of-flight mass spectrometry. Multiple-charge atomic ions of C q+ and I q+ ( q ⩾ 2) were observed using 532 and 1064 nm laser wavelengths; however, only single-charge atomic and molecular ions appeared at 266 and 355 nm. We show that the charge-state distribution for multiple-charge ions is almost independent of laser intensity. A three-stage model was developed to further understand these experimental results: the inverse electron bremsstrahlung heating rate is proportional to the square of laser wavelength, which seems to explain the dependence of multiple-charge ions on the wavelength.

  3. Low energy alkali ion-surface charge exchange for Si(111) as a function of doping

    NASA Astrophysics Data System (ADS)

    Gann, Reuben D.; Yarmoff, Jory A.

    2011-03-01

    Alkali ion-surface charge exchange, which can be used to probe surface electronic states, is well understood within the context of the resonant charge transfer (RCT) model. Recent studies have extended the use of alkali ion scattering and the RCT model from metal surfaces to semiconductors and insulators. In the present work, we measure the effect of doping type and concentration on the neutralization probability of alkali ions scattered from semiconductors. Si(111) surfaces were prepared in UHV, and the neutralization probability of scattered Li + ions was measured for projectiles that were singly scattered from Si atomic sites. For the clean Si(111)- 7 × 7 surface, the neutralization is determined by the surface electronic states and is independent of doping. Samples were then dosed with atomic hydrogen in order to passivate the surface states and unpin the Fermi level. This affects the neutralization probabilities and reveals differences between n and p-type materials.

  4. Atomic physics with highly charged ions

    SciTech Connect

    Richard, P.

    1991-08-01

    This report discusses: One electron outer shell processes in fast ion-atom collisions; role of electron-electron interaction in two-electron processes; multi-electron processes at low energy; multi-electron processes at high energy; inner shell processes; molecular fragmentation studies; theory; and, JRM laboratory operations.

  5. Emission of secondary particles from metals and insulators at impact of slow highly charged ions

    SciTech Connect

    Schenkel, T.

    1996-10-31

    Emission of secondary electrons and ions from clean Au, CxHy-Au, and SiO{sub 2} surfaces at impact of slow (v{approx}0.3 v{sub Bohr}) ions were measured as function of incident ion charge for 1+{le}q{le}75+. Electron yields from thermal SiO{sub 2} films (150 mm on Si) were found to be lower than those from the other two for q>3+. Yields of negative secondary ions from SiO{sub 2} and CxHy-Au were recorded in parallel with electron emission data and exhibit a q{sub 4} dependency on incident ion charge. Direct comparison of collisional and electronic contributions to secondary ion production from SiO{sub 2} films using a beam of charge state equilibrated Xe (at 2.75 keV/u) shows positive and negative secondary ion yield increases with incident ion charge of >400. Results are discussed in relation to key signatures of electronic sputtering by Coulomb explosions.

  6. Fragmentation of phosphorylated and singly charged peptide ions via interaction with metastable atoms

    PubMed Central

    Berkout, Vadym D.; Doroshenko, Vladimir M.

    2008-01-01

    Fragmentation of phosphorylated peptide ions via interaction with electronically excited metastable argon atoms was studied in a linear trap – time-of-flight mass spectrometer. Doubly charged ions of phosphorylated peptides from an Enolase digest were produced by electrospray ionization and subjected to a metastable atom beam in the linear trap. The metastable argon atoms were generated using a glow-discharge source. An intensive series of c- and z- ions were observed in all cases, with the phosphorylation group intact. The formation of molecular radical cations with reduced charge indicated that an electron transfer from a highly excited metastable state of argon to the peptide cation occurred. Additionally, singly charged Bradykinin, Substance P and Fibrinopeptide A molecular ions were fragmented via interaction with electronically excited metastable helium atoms. The fragmentation mechanism was different in this case and involved Penning ionization. PMID:19956340

  7. Ion temperatures in HIP-1 and SUMMA from charge-exchange neutral optical emission spectra

    NASA Technical Reports Server (NTRS)

    Patch, R. W.; Lauver, M. R.

    1976-01-01

    Ion temperatures were obtained from observations of the H sub alpha, D sub alpha, and He 587.6 nm lines emitted from hydrogen, deuterium, and helium plasmas in the SUMMA and HIP-1 mirror devices at Lewis Research Center. Steady state discharges were formed by applying a radially inward dc electric field between cylindrical or annular anodes and hollow cathodes located at the peaks of the mirrors. The ion temperatures were found from the Doppler broadening of the charge-exchange components of spectral lines. A statistical method was developed for obtaining scaling relations of ion temperature as a function of current, voltage, and magnetic flux density. Derivations are given that take into account triangular monochromator slit functions, loss cones, and superimposed charge-exchange processes. In addition, the Doppler broadening was found to be sensitive to the influence of drift on charge-exchange cross section. The effects of finite ion-cyclotron radius, cascading, and delayed emission are reviewed.

  8. Fragmentation of phosphorylated and singly charged peptide ions via interaction with metastable atoms.

    PubMed

    Berkout, Vadym D; Doroshenko, Vladimir M

    2008-12-01

    Fragmentation of phosphorylated peptide ions via interaction with electronically excited metastable argon atoms was studied in a linear trap - time-of-flight mass spectrometer. Doubly charged ions of phosphorylated peptides from an Enolase digest were produced by electrospray ionization and subjected to a metastable atom beam in the linear trap. The metastable argon atoms were generated using a glow-discharge source. An intensive series of c- and z- ions were observed in all cases, with the phosphorylation group intact. The formation of molecular radical cations with reduced charge indicated that an electron transfer from a highly excited metastable state of argon to the peptide cation occurred. Additionally, singly charged Bradykinin, Substance P and Fibrinopeptide A molecular ions were fragmented via interaction with electronically excited metastable helium atoms. The fragmentation mechanism was different in this case and involved Penning ionization.

  9. Optical state-of-charge monitor for batteries

    SciTech Connect

    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.

  10. Solar wind ionization temperatures inferred from the charge state composition of diffuse particle events

    NASA Technical Reports Server (NTRS)

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

    1984-01-01

    Detailed measurements of the charge state composition of energetic heavy ions in the diffuse component are presented for the first time. Spectral characteristics and charge state measurements for 12 diffuse ion events observed upstream of the earth's bow shock are reported. One event is analyzed in order to illustrate the basic assumptions and general techniques involved in the determination of charge state composition from the data. The probable solar wind origin of the seed population of the diffuse component is used together with the charge state composition of these heavy ions to estimate the charge state composition in the concurrent solar wind, and hence to infer the equilibrium coronal temperatures associated with a variety of solar wind flows. The results are compared with predicted solar wind values.

  11. Effects of Ti charge state, ion size and beam-induced compaction on the formation of Ag metal nanoparticles in fused silica

    NASA Astrophysics Data System (ADS)

    Magruder, R. H.; Meldrum, A.; Haglund, R. F.

    2015-04-01

    Metal nanoparticles formed by ion implantation in fused silica exhibit linear and nonlinear optical properties that can be altered by co-doping the silica substrate with transition-metal ions. For example, implantation of scandium in fused silica creates a directional optical dichroism due to the different spatial distribution of silver nanoparticles subsequently formed by Ag ion implantation. In this paper, we show that implantation of titanium ions alters the short- and intermediate-range order in the silica and thereby alters the diffusion and nucleation processes that lead to formation of silver nanoparticles. In particular, the dichroic response observed for Ag nanoparticles in Sc-implanted silica is, with one exception, in Ti-implanted silica. Compaction of the silica due to the ion implantation process appears to be similar for both Sc and Ti implantations, based on the observed shift of the 1,124 cm-1 transverse-optical phonon mode in the infrared reflectance spectrum. However, differences in chemical reactivity, bond lengths and electronic structure of Sc and Ti produce changes in electronic structure and strain that are sensitively reflected in the reflectance spectra of the Ag nanoparticles. These differences lead to modifications in the size, shape and spatial distributions of the silver nanoparticles and offer a powerful means of controlling their optical properties.

  12. X-ray emission cross sections following charge exchange by multiply charged ions of astrophysical interest

    SciTech Connect

    Otranto, S.; Olson, R. E.; Beiersdorfer, P.

    2006-02-15

    State selective nl-electron capture cross sections are presented for highly charged ions with Z=6-10 colliding with atoms and molecules. The energy range investigated was from 1 eV/amu(v=0.006 a.u.)to 100 keV/amu(v=2.0 a.u.). The energy dependence of the l-level populations is investigated. The K shell x-ray emission cross sections are determined by using the calculated state-selective electron capture results as input and then applying hydrogenic branching and cascading values for the photon emission. A major shift in the line emission from being almost solely Lyman-{alpha} transitions at the highest collisions energies to strong high-n to 1s transitions at the lowest energies is observed. The calculated cross sections are in reasonable accord with measurements made by Greenwood et al. [Phys. Rev. A 63, 062707 (2001)], using O{sup 8+} and Ne{sup 10+} on various targets at 3 keV/amu. The calculations are also in accord with x-ray emission cross section data obtained on the EBIT machine at Lawrence Livermore National Laboratory (LLNL) where O{sup 8+} and Ne{sup 10+} high resolution measurements were made at a temperature of 10 eV/amu for a series of targets with varying ionization potentials. The Ne{sup 10+} data clearly shows the contribution from multiple capture followed by Auger autoionization in the line emission spectra. Our calculated line emission cross sections are used to provide an ab initio determination of the soft x-ray spectrum of comet C/Linear 1999 S4 that was observed on the Chandra X-ray Observatory. The calculations show that the spectrum is due to the charge exchange of the neutral gases in the comet's coma with the ions of the slow solar wind.

  13. On the Analytical Model of Charge Evolution of Solar Flare Ions

    NASA Astrophysics Data System (ADS)

    Perez-Peraza, Jorge; Balderas-Avilez, Gabriel; Rodriguez-Frias, Dolores; Del Peral, Luis; Hebrero, Gema; Cruz, Ricardo

    Models attempting to describe the charge state of solar flare ions are in general of numerical nature, where the involved physics is masked by their high mathematical complexity. There is however, the oldest of the models, developed long ago for one of us, which is of analytical nature, and based in very simple physical concepts, namely hereafter the High Energy Crosssections Model (HECSM). In this model definition of the charge state of the energetic ions occurs during the acceleration process at the flare source. It is assumed the atomic interactions between a population which is being accelerated getting an exponential (or power law) spectrum, namely the ions projectiles, and another population which is in thermodynamic equilibrium (TE), with a Maxwellian spectrum, namely the targets. In contrast with other models that use thermal cross-sections (ionization and recombination) even for energetic ions which are out of the (TE), in our model we employ High Energy Cross-sections for electron capture and loss, since the population which is being accelerated acquires a non-thermal spectrum. First, we have built temperature-dependent cross-sections. Then, we have developed criteria for charge interchange establishment, it is determined whether there is establishment of (1) both processes, capture and los, or (2) only one of them, or even (3) none of them. In case (1) charge equilibrium is reached. In case (2) when only electron capture is established, at the beginning of the acceleration process, the local charge value will decrease up to an energy where both crosssection becomes of the same order, or when only electron loss is established the effective charge goes faster toward the nuclear charge value than in conditions of charge equilibrium. In case (3) ions keep the local thermal charge at the source temperature. After, we derivate an analytical expression for the Effective Charge (equilibrium charge), qef f, on basis to direct and simple physical concepts. We

  14. Probing the vacuum with highly charged ions

    SciTech Connect

    Bottcher, C.; Strayer, M.R.

    1987-01-01

    The physics of the Fermion vacuum is briefly described, and applied to pair production in heavy ion collisions. We consider in turn low energies (<50 MeV/nucleon), intermediate energies (<5 GeV/nucleon), and ultrahigh energies such as would be produced in a ring collider. At high energies, interesting questions of Lorentz and gauge invariance arise. Finally, some applications to the structure of high Z atoms are examined. 14 refs., 11 figs.

  15. Electroweak Decay Studies of Highly Charged Radioactive Ions with TITAN at TRIUMF

    NASA Astrophysics Data System (ADS)

    Leach, Kyle; Dillmann, Iris; Klawitter, Renee; Leistenschneider, Erich; Lennarz, Annika; Brunner, Thomas; Frekers, Dieter; Andreoiu, Corina; Kwiatkowski, Anna; Dilling, Jens

    2017-03-01

    Several modes of electroweak radioactive decay require an interaction between the nucleus and bound electrons within the constituent atom. Thus, the probabilities of the respective decays are not only influenced by the structure of the initial and final states in the nucleus, but can also depend strongly on the atomic charge. Conditions suitable for the partial or complete ionization of these rare isotopes occur naturally in hot, dense astrophysical environments, but can also be artificially generated in the laboratory to selectively block certain radioactive decay modes. Direct experimental studies on such scenarios are extremely difficult due to the laboratory conditions required to generate and store radioactive ions at high charge states. A new electron-beam ion trap (EBIT) decay setup with the TITAN experiment at TRIUMF has successfully demonstrated such techniques for performing spectroscopy on the radioactive decay of highly charged ions.

  16. EBIT spectroscopy of highly charged heavy ions relevant to hot plasmas

    NASA Astrophysics Data System (ADS)

    Nakamura, Nobuyuki

    2013-05-01

    An electron beam ion trap (EBIT) is a versatile device for studying highly charged ions. We have been using two types of EBITs for the spectroscopic studies of highly charged ions. One is a high-energy device called the Tokyo-EBIT, and another is a compact low-energy device called CoBIT. Complementary use of them enables us to obtain spectroscopic data for ions over a wide charge-state range interacting with electrons over a wide energy range. In this talk, we present EBIT spectra of highly charged ions for tungsten, iron, bismuth, etc., which are relevant to hot plasmas. Tungsten is considered to be the main impurity in the ITER (the next generation nuclear fusion reactor) plasma, and thus its emission lines are important for diagnosing and controlling the ITER plasma. We have observed many previously unreported lines to supply the lack of spectroscopic data of tungsten ions. Iron is one of the main components of the solar corona, and its spectra are used to diagnose temperature, density, etc. The diagnostics is usually done by comparing observed spectra with model calculations. An EBIT can provide spectra under a well-defined condition; they are thus useful to test the model calculations. Laser-produced bismuth plasma is one of the candidates for a soft x-ray source in the water window region. An EBIT has a narrow charge state distribution; it is thus useful to disentangle the spectra of laser-produced plasma containing ions with a wide charge-state range. Performed with the support and under the auspices of the NIFS Collaboration Research program (NIFS09KOAJ003) and JSPS KAKENHI Number 23246165, and partly supported by the JSPS-NRF-NSFC A3 Foresight Program in the field of Plasma Physics.

  17. 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.

  18. 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

    2016-05-16

    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.

  19. 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

  20. Charge breeding results and future prospects with electron cyclotron resonance ion source and electron beam ion source (invited)

    SciTech Connect

    Vondrasek, R.; Levand, A.; Pardo, R.; Savard, G.; Scott, R.

    2012-02-15

    The Californium Rare Ion Breeder Upgrade (CARIBU) of the Argonne National Laboratory ATLAS facility will provide low-energy and reaccelerated neutron-rich radioactive beams for the nuclear physics program. A 70 mCi {sup 252}Cf source produces fission fragments which are thermalized and collected by a helium gas catcher into a low-energy particle beam with a charge of 1+ or 2+. An electron cyclotron resonance (ECR) ion source functions as a charge breeder in order to raise the ion charge sufficiently for acceleration in the ATLAS linac. The final CARIBU configuration will utilize a 1 Ci {sup 252}Cf source to produce radioactive beams with intensities up to 10{sup 6} ions/s for use in the ATLAS facility. The ECR charge breeder has been tested with stable beam injection and has achieved charge breeding efficiencies of 3.6% for {sup 23}Na{sup 8+}, 15.6% for {sup 84}Kr{sup 17+}, and 13.7% for {sup 85}Rb{sup 19+} with typical breeding times of 10 ms/charge state. For the first radioactive beams, a charge breeding efficiency of 11.7% has been achieved for {sup 143}Cs{sup 27+} and 14.7% for {sup 143}Ba{sup 27+}. The project has been commissioned with a radioactive beam of {sup 143}Ba{sup 27+} accelerated to 6.1 MeV/u. In order to take advantage of its lower residual contamination, an EBIS charge breeder will replace the ECR charge breeder in the next two years. The advantages and disadvantages of the two techniques are compared taking into account the requirements of the next generation radioactive beam facilities.

  1. Charge breeding results and future prospects with electron cyclotron resonance ion source and electron beam ion source (invited)a)

    NASA Astrophysics Data System (ADS)

    Vondrasek, R.; Levand, A.; Pardo, R.; Savard, G.; Scott, R.

    2012-02-01

    The Californium Rare Ion Breeder Upgrade (CARIBU) of the Argonne National Laboratory ATLAS facility will provide low-energy and reaccelerated neutron-rich radioactive beams for the nuclear physics program. A 70 mCi 252Cf source produces fission fragments which are thermalized and collected by a helium gas catcher into a low-energy particle beam with a charge of 1+ or 2+. An electron cyclotron resonance (ECR) ion source functions as a charge breeder in order to raise the ion charge sufficiently for acceleration in the ATLAS linac. The final CARIBU configuration will utilize a 1 Ci 252Cf source to produce radioactive beams with intensities up to 106 ions/s for use in the ATLAS facility. The ECR charge breeder has been tested with stable beam injection and has achieved charge breeding efficiencies of 3.6% for 23Na8+, 15.6% for 84Kr17+, and 13.7% for 85Rb19+ with typical breeding times of 10 ms/charge state. For the first radioactive beams, a charge breeding efficiency of 11.7% has been achieved for 143Cs27+ and 14.7% for 143Ba27+. The project has been commissioned with a radioactive beam of 143Ba27+ accelerated to 6.1 MeV/u. In order to take advantage of its lower residual contamination, an EBIS charge breeder will replace the ECR charge breeder in the next two years. The advantages and disadvantages of the two techniques are compared taking into account the requirements of the next generation radioactive beam facilities.

  2. 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.

  3. Emission Spectroscopy of Highly Charged Ions in Plasma of an Electron Beam Ion Trap

    SciTech Connect

    Draganic, I.; Crespo Lopez-Urrutia, J.R.; Soria Orts, R.; Ullrich, J.; DuBois, R.; Shevelko, V.; Fritzsche, S.; Zou, Y.

    2004-12-01

    The results of experimental study of magnetic dipole (M1) transitions in highly charged ions of argon (Ar9+, Ar10+, Ar13+ and Ar14+) and krypton (Kr18+ and Kr22+) are presented. The forbidden transitions of the highly charged ions in the visible and near UV range of the photon emission spectra have been measured with accuracy better than 1 ppm. Our measurements for the 'coronal lines' are the most accurate yet reported using an EBIT as a spectroscopic source of highly charged ions. These precise wavelength determinations provide a useful test and challenge for atomic structure calculations of many-electron systems.

  4. Charge-exchange plasma generated by an ion thruster

    NASA Technical Reports Server (NTRS)

    Kaufman, H. R.

    1977-01-01

    The charge exchange plasma generated by an ion thruster was investigated experimentally using both 5 cm and 15 cm thrusters. Results are shown for wide ranges of radial distance from the thruster and angle from the beam direction. Considerations of test environment, as well as distance from the thruster, indicate that a valid simulation of a thruster on a spacecraft was obtained. A calculation procedure and a sample calculation of charge exchange plasma density and saturation electron current density are included.

  5. Studies of emittance of multiply charged ions extracted from high temperature superconducting electron cyclotron resonance ion source, PKDELIS

    SciTech Connect

    Rodrigues, G.; Lakshmy, P. S.; Kumar, Sarvesh; Mandal, A.; Kanjilal, D.; Roy, A.; Baskaran, R.

    2010-02-15

    For the high current injector project at Inter University Accelerator Centre, a high temperature superconducting electron cyclotron resonance (ECR) ion source, PKDELIS, would provide the high charge state ions. The emittance of the ECR ion source is an important parameter to design further beam transport system and to match the acceptances of the downstream radio frequency quadrupole and drift tube linac accelerators of the high current injector. The emittance of the analyzed beam of PKDELIS ECR source has been measured utilizing the three beam size technique. A slit and two beam profile monitors positioned at fixed distances from each other were used to measure the beam size. The digitized beam profiles have been analyzed to determine the emittance of various multiply charged ions. The variation of emittance with gas mixing, ultrahigh frequency power, and extraction energy are discussed in this presentation.

  6. Production of highly charged ion beams with SECRAL.

    PubMed

    Sun, L T; Zhao, H W; Lu, W; Zhang, X Z; Feng, Y C; Li, J Y; Cao, Y; Guo, X H; Ma, H Y; Zhao, H Y; Shang, Y; Ma, B H; Wang, H; Li, X X; Jin, T; Xie, D Z

    2010-02-01

    Superconducting electron cyclotron resonance ion source with advanced design in Lanzhou (SECRAL) is an all-superconducting-magnet electron cyclotron resonance ion source (ECRIS) for the production of intense highly charged ion beams to meet the requirements of the Heavy Ion Research Facility in Lanzhou (HIRFL). To further enhance the performance of SECRAL, an aluminum chamber has been installed inside a 1.5 mm thick Ta liner used for the reduction of x-ray irradiation at the high voltage insulator. With double-frequency (18+14.5 GHz) heating and at maximum total microwave power of 2.0 kW, SECRAL has successfully produced quite a few very highly charged Xe ion beams, such as 10 e microA of Xe(37+), 1 e microA of Xe(43+), and 0.16 e microA of Ne-like Xe(44+). To further explore the capability of the SECRAL in the production of highly charged heavy metal ion beams, a first test run on bismuth has been carried out recently. The main goal is to produce an intense Bi(31+) beam for HIRFL accelerator and to have a feel how well the SECRAL can do in the production of very highly charged Bi beams. During the test, though at microwave power less than 3 kW, more than 150 e microA of Bi(31+), 22 e microA of Bi(41+), and 1.5 e microA of Bi(50+) have been produced. All of these results have again demonstrated the great capability of the SECRAL source. This article will present the detailed results and brief discussions to the production of highly charged ion beams with SECRAL.

  7. Production of highly charged ion beams with SECRAL

    SciTech Connect

    Sun, L. T.; Zhao, H. W.; Zhang, X. Z.; Feng, Y. C.; Li, J. Y.; Guo, X. H.; Ma, H. Y.; Zhao, H. Y.; Ma, B. H.; Wang, H.; Li, X. X.; Jin, T.; Xie, D. Z.; Lu, W.; Cao, Y.; Shang, Y.

    2010-02-15

    Superconducting electron cyclotron resonance ion source with advanced design in Lanzhou (SECRAL) is an all-superconducting-magnet electron cyclotron resonance ion source (ECRIS) for the production of intense highly charged ion beams to meet the requirements of the Heavy Ion Research Facility in Lanzhou (HIRFL). To further enhance the performance of SECRAL, an aluminum chamber has been installed inside a 1.5 mm thick Ta liner used for the reduction of x-ray irradiation at the high voltage insulator. With double-frequency (18+14.5 GHz) heating and at maximum total microwave power of 2.0 kW, SECRAL has successfully produced quite a few very highly charged Xe ion beams, such as 10 e {mu}A of Xe{sup 37+}, 1 e {mu}A of Xe{sup 43+}, and 0.16 e {mu}A of Ne-like Xe{sup 44+}. To further explore the capability of the SECRAL in the production of highly charged heavy metal ion beams, a first test run on bismuth has been carried out recently. The main goal is to produce an intense Bi{sup 31+} beam for HIRFL accelerator and to have a feel how well the SECRAL can do in the production of very highly charged Bi beams. During the test, though at microwave power less than 3 kW, more than 150 e {mu}A of Bi{sup 31+}, 22 e {mu}A of Bi{sup 41+}, and 1.5 e {mu}A of Bi{sup 50+} have been produced. All of these results have again demonstrated the great capability of the SECRAL source. This article will present the detailed results and brief discussions to the production of highly charged ion beams with SECRAL.

  8. Non-equilibrium energy loss for very highly charged ions in insulators

    SciTech Connect

    Briere, M.A.; Schenkel, T.; Bauer, P.; Amau, A.

    1996-12-31

    The energy loss of 144 keV Ar{sup +16} ions on a bilayer structure of C-CaF{sub 2} has been measured. An asymmetry in the results is found depending on which layer is passed by the ion first: the energy loss is about four times larger when the CaF{sub 2} layer is traversed by the ion first. We interpret this as an indication of the existence of a nonequilibrium charge state of the Ar ions inside the solid in the case of the insulator.

  9. The Oxford electron-beam ion trap: A device for spectroscopy of highly charged ions

    NASA Astrophysics Data System (ADS)

    Silver, J. D.; Varney, A. J.; Margolis, H. S.; Baird, P. E. G.; Grant, I. P.; Groves, P. D.; Hallett, W. A.; Handford, A. T.; Hirst, P. J.; Holmes, A. R.; Howie, D. J. H.; Hunt, R. A.; Nobbs, K. A.; Roberts, M.; Studholme, W.; Wark, J. S.; Williams, M. T.; Levine, M. A.; Dietrich, D. D.; Graham, W. G.; Williams, I. D.; O'Neil, R.; Rose, S. J.

    1994-04-01

    An electron-beam ion trap (EBIT) has just been completed in the Clarendon Laboratory, Oxford. The design is similar to the devices installed at the Lawrence Livermore National Laboratory. It is intended that the Oxford EBIT will be used for x-ray and UV spectroscopy of hydrogenic and helium-like ions, laser resonance spectroscopy of hydrogenic ions and measurements of dielectronic recombination cross sections, in order to test current understanding of simple highly charged ions.

  10. Size and Charge Distributions of Stable Clusters Formed in Ion Sputtering of Metals

    NASA Astrophysics Data System (ADS)

    Matveev, V. I.; Kapustin, S. N.

    2016-10-01

    A theory of ion sputtering of metals in the form of neutral and charged clusters with their subsequent fragmentation into the stable state is developed. The theory is based on simple physical assumptions and is in good agreement with experiment. Results are presented in the form of formulas convenient for practical application. As an example, calculations of the total yield of stable neutral and charged clusters of silver, indium, and niobium are carried out.

  11. Ionization Efficiency of Doubly Charged Ions Formed from Polyprotic Acids in Electrospray Negative Mode

    NASA Astrophysics Data System (ADS)

    Liigand, Piia; Kaupmees, Karl; Kruve, Anneli

    2016-07-01

    The ability of polyprotic acids to give doubly charged ions in negative mode electrospray was studied and related to physicochemical properties of the acids via linear discriminant analysis (LDA). It was discovered that the compound has to be strongly acidic (low p K a1 and p K a2) and to have high hydrophobicity (log P ow) to become multiply charged. Ability to give multiply charged ions in ESI/MS cannot be directly predicted from the solution phase acidities. Therefore, for the first time, a quantitative model to predict the charge state of the analyte in ESI/MS is proposed and validated for small anions. Also, a model to predict ionization efficiencies of these analytes was developed. Results indicate that acidity of the analyte, its octanol-water partition coefficient, and charge delocalization are important factors that influence ionization efficiencies as well as charge states of the analytes. The pH of the solvent was also found to be an important factor influencing the ionization efficiency of doubly charged ions.

  12. Polarization and charge transfer in the hydration of chloride ions

    SciTech Connect

    Zhao Zhen; Rogers, David M.; Beck, Thomas L.

    2010-01-07

    A theoretical study of the structural and electronic properties of the chloride ion and water molecules in the first hydration shell is presented. The calculations are performed on an ensemble of configurations obtained from molecular dynamics simulations of a single chloride ion in bulk water. The simulations utilize the polarizable AMOEBA force field for trajectory generation and MP2-level calculations are performed to examine the electronic structure properties of the ions and surrounding waters in the external field of more distant waters. The ChelpG method is employed to explore the effective charges and dipoles on the chloride ions and first-shell waters. The quantum theory of atoms in molecules (QTAIM) is further utilized to examine charge transfer from the anion to surrounding water molecules. The clusters extracted from the AMOEBA simulations exhibit high probabilities of anisotropic solvation for chloride ions in bulk water. From the QTAIM analysis, 0.2 elementary charges are transferred from the ion to the first-shell water molecules. The default AMOEBA model overestimates the average dipole moment magnitude of the ion compared to the quantum mechanical value. The average magnitude of the dipole moment of the water molecules in the first shell treated at the MP2-level, with the more distant waters handled with an AMOEBA effective charge model, is 2.67 D. This value is close to the AMOEBA result for first-shell waters (2.72 D) and is slightly reduced from the bulk AMOEBA value (2.78 D). The magnitude of the dipole moment of the water molecules in the first solvation shell is most strongly affected by the local water-water interactions and hydrogen bonds with the second solvation shell, rather than by interactions with the ion.

  13. Charges and current induced by moving ions in multiwire chambers

    NASA Astrophysics Data System (ADS)

    Erskine, G. A.

    1982-07-01

    A method for calculating the charges induced on the grid wires, and on cathode strips parallel to the grid wires, by a point charge in a multiwire chamber is described. The method is applied to the calculation, as a function of time, of the charge and current induced by a small group of positive ions moving in accordance with the drift equation v= μE where v is the velocity. An appendix lists a number of formulae relating to the electrostatic field of a multiwire chamber.

  14. Selection of charge methods for lithium ion batteries by considering diffusion induced stress and charge time

    NASA Astrophysics Data System (ADS)

    Lu, Bo; Song, Yicheng; Zhang, Junqian

    2016-07-01

    This article demonstrates the design of charging strategies for lithium ion batteries with considering the balance between diffusion induced stress and total charge time for two- and three-stage charge methods. For the two-stage galvanostatic-potentiostatic charge method the low mechanical stress can be achieved without increasing total charge time by switching the galvanostatic to the potentiostatic at the time moment when the lithium concentration at the surface of particles reaches the limit cbarsurf = 0 . A three-stage method, which consists of an initial galvanostatic stage of high current, a galvanostatic stage of low current and a potentiostatic ending stage, is suggested. Employing the initial galvanostatic stage of high current is helpful not only in accelerating the charge process, but also in controlling the mechanical stress once the electrical current and time duration of the initial galvanostatic stage are properly designed.

  15. Bridging like-charged macroions through long divalent rodlike ions.

    PubMed

    May, Sylvio; Iglic, Ales; Rescic, Jurij; Maset, Stefano; Bohinc, Klemen

    2008-02-14

    Like-charged macroions in aqueous electrolyte solution can attract each other because of the presence of inter- and/or intramolecular correlations. Poisson-Boltzmann theory is able to predict attractive interactions if the spatially extended structure (which reflects the presence of intramolecular correlations) of the mobile ions in the electrolyte is accounted for. We demonstrate this for the case of divalent, mobile ions where each ion consists of two individual charges separated by a fixed distance. Variational theory applied to this symmetric 2:2 electrolyte of rodlike ions leads to an integro-differential equation, valid for arbitrary rod length. Numerical solutions reveal the existence of a critical rod length above which electrostatic attraction starts to emerge. This electrostatic attraction is distinct from nonelectrostatic depletion forces. Analysis of the orientational distribution functions suggests a bridging mechanism of the rodlike ions to hold the two macroions together. For sufficiently large rod length, we also observe "overcharging", that is, an over-compensation of the macroion charges by the diffuse layer of mobile rodlike ions. Our results emphasize the importance of the often rodlike internal structure that condensing agents such as polyamines, peptides, or polymer segments exhibit. The results were compared with Monte Carlo simulations.

  16. Commercial intermediate pressure MALDI ion mobility spectrometry mass spectrometer capable of producing highly charged laserspray ionization ions.

    PubMed

    Inutan, Ellen D; Wang, Beixi; Trimpin, Sarah

    2011-02-01

    The first examples of highly charged ions observed under intermediate pressure (IP) vacuum conditions are reported using laser ablation of matrix/analyte mixtures. The method and results are similar to those obtained at atmospheric pressure (AP) using laserspray ionization (LSI) and/or matrix assisted inlet ionization (MAII). Electrospray ionization (ESI), LSI, and MAII are methods operating at AP and have been shown, with or without the use of a voltage or a laser, to produce highly charged ions with very similar ion abundance and charge states. A commercial matrix-assisted laser desorption/ionization ion mobility spectrometry (IMS) mass spectrometry (MS) instrument (SYNAPT G2) was used for the IP developments. The necessary conditions for producing highly charged ions of peptides and small proteins at IP appear to be a pressure drop region and the use of suitable matrixes and laser fluence. Ionization to produce these highly charged ions under the low pressure conditions of IP does not require specific heating or a special inlet ion transfer region. However, under the current setup, ubiquitin is the highest molecular weight protein observed. These findings are in accord with the need to provide thermal energy in the pressure drop region, similar to LSI and MAII, to improve sensitivity and extend the types of compounds that produce highly charged ions. The practical utility of IP-LSI in combination with IMS-MS is demonstrated for the analysis of model mixtures composed of a lipid, peptides, and a protein. Further, endogenous multiply charged peptides are observed directly from delipified mouse brain tissue with drift time distributions that are nearly identical in appearance to those obtained from a synthesized neuropeptide standard analyzed by either LSI- or ESI-IMS-MS at AP. Efficient solvent-free gas-phase separation enabled by the IMS dimension separates the multiply charged peptides from lipids that remained on the delipified tissue. Lipid and peptide

  17. Prospects for advanced electron cyclotron resonance and electron beam ion source charge breeding methods for EURISOL

    SciTech Connect

    Delahaye, P.; Jardin, P.; Maunoury, L.; Traykov, E.; Varenne, F.; Angot, J.; Lamy, T.; Sortais, P.; Thuillier, T.; Ban, G.; Celona, L.; Lunney, D.; Choinski, J.; Gmaj, P.; Jakubowski, A.; Steckiewicz, O.; Kalvas, T.; and others

    2012-02-15

    As the most ambitious concept of isotope separation on line (ISOL) facility, EURISOL aims at producing unprecedented intensities of post-accelerated radioactive isotopes. Charge breeding, which transforms the charge state of radioactive beams from 1+ to an n+ charge state prior to post-acceleration, is a key technology which has to overcome the following challenges: high charge states for high energies, efficiency, rapidity and purity. On the roadmap to EURISOL, a dedicated R and D is being undertaken to push forward the frontiers of the present state-of-the-art techniques which use either electron cyclotron resonance or electron beam ion sources. We describe here the guidelines of this R and D.

  18. Production of multiply charged ion beams from solid substances with the mVINIS ion source

    SciTech Connect

    Draganic, I.; Dobrosavljevic, A.; Nedeljkovic, T.; Siljegovic, M.

    2006-03-15

    The mVINIS ion source has enabled us to obtain multiply charged ion beams from gases as well as from solid materials. The solid substance ion beams were produced by using two techniques: (a) the evaporation of metals by using the inlet system based on a minioven and (b) the metal-ions-from-volatile-compounds method (MIVOC) by using the modified gas inlet system. Great efforts were made in the production of high current stable ion beams of solids with relatively high melting points (over 1000 deg. C). The B{sup 3+} ion-beam current of over 300 {mu}A was one of the most intensive beams extracted until now. The obtained multiply charged ion-beam spectra of solid substances (B, Fe, and Zn) are presented as well as some of the corresponding experimental results achieved during the modification of polymers, carbon materials, and fullerenes.

  19. Charge state separation for protein applications using a quadrupole time-of-flight mass spectrometer.

    PubMed

    Chernushevich, I V; Fell, L M; Bloomfield, N; Metalnikov, P S; Loboda, A V

    2003-01-01

    A novel method for separating ions according to their charge state using a quadrupole time-of-flight mass spectrometer is presented. The benefits of charge state separation are particularly apparent in protein identification applications at low femtomole concentration levels, where in conventional TOF MS spectra peptide ions are often lost in a sea of chemical noise. When doubly and triply charged tryptic peptide ions need to be filtered from singly charged background ions, the latter are suppressed by two to three orders of magnitude, while from 10-50% of multiply charged ions remain. The suppression of chemical noise reduces the need for chromatography and can make this experimental approach the electrospray equivalent of conventional MALDI peptide maps. If unambiguous identification cannot be achieved, MS/MS experiments are performed on the precursor ions identified through charge separation, while the previously described Q2-trapping duty cycle enhancement is tuned for approximately 1.4 of the precursor m/z to enhance intensities of ions with m/z values above that of the precursor. The resulting product ion spectra contain few fragments of impurities and provide quick and unambiguous identification through database search. The multiple charge separation technique requires minimal tuning and may become a useful tool for analysis of complex mixtures.

  20. Charge-Control Unit for Testing Lithium-Ion Cells

    NASA Technical Reports Server (NTRS)

    Reid, Concha M.; Mazo, Michelle A.; Button, Robert M.

    2008-01-01

    A charge-control unit was developed as part of a program to validate Li-ion cells packaged together in batteries for aerospace use. The lithium-ion cell charge-control unit will be useful to anyone who performs testing of battery cells for aerospace and non-aerospace uses and to anyone who manufacturers battery test equipment. This technology reduces the quantity of costly power supplies and independent channels that are needed for test programs in which multiple cells are tested. Battery test equipment manufacturers can integrate the technology into their battery test equipment as a method to manage charging of multiple cells in series. The unit manages a complex scheme that is required for charging Li-ion cells electrically connected in series. The unit makes it possible to evaluate cells together as a pack using a single primary test channel, while also making it possible to charge each cell individually. Hence, inherent cell-to-cell variations in a series string of cells can be addressed, and yet the cost of testing is reduced substantially below the cost of testing each cell as a separate entity. The unit consists of electronic circuits and thermal-management devices housed in a common package. It also includes isolated annunciators to signal when the cells are being actively bypassed. These annunciators can be used by external charge managers or can be connected in series to signal that all cells have reached maximum charge. The charge-control circuitry for each cell amounts to regulator circuitry and is powered by that cell, eliminating the need for an external power source or controller. A 110-VAC source of electricity is required to power the thermal-management portion of the unit. A small direct-current source can be used to supply power for an annunciator signal, if desired.

  1. Dressed counterions: Polyvalent and monovalent ions at charged dielectric interfaces

    NASA Astrophysics Data System (ADS)

    Kanduč, Matej; Naji, Ali; Forsman, Jan; Podgornik, Rudolf

    2011-07-01

    We investigate the ion distribution and overcharging at charged interfaces with dielectric inhomogeneities in the presence of asymmetric electrolytes containing polyvalent and monovalent ions. We formulate an effective “dressed counterion” approach by integrating out the monovalent salt degrees of freedom and show that it agrees with results of explicit Monte Carlo simulations. We then apply the dressed counterion approach within the framework of the generalized strong-coupling theory, valid for polyvalent ions at low concentrations, which enables an analytical description for salt effects as well as dielectric inhomogeneities in the limit of strong Coulomb interactions. Limitations and applicability of this theory are examined by comparing the results with simulations.

  2. Experimental Studies of Ion Charge Ion Flux in Streaming Plasmas.

    DTIC Science & Technology

    1980-12-01

    THIS PAGE (When Data Entered) L T R C I N CEflBIDOCUETATIONPDAGE BFRECMLTIGFR GOVTACCSOON O.3RECIPIENT’S C( 744,,OG NUMBER q v ]WERMENAL TUDIES OF ION...Controlling Office) IS. SECURITY CLASS. (of t )*r~g unclassified £ - 15.OECLASSIFICATION DOWNGRADING 16. DISTRIBUTION STATEMENT (of this Report) qp...radiation, such as in our experiment, will decrease as the inverse square of the radius; blast wave theory then predicts(13) R~ t / t ccnh where n is

  3. Characterization of a Bernas ion source for multiply charged ion implantation

    NASA Astrophysics Data System (ADS)

    Walther, S. R.

    1994-04-01

    Due to concerns about energy purity and reduced beam current, the use of multiply charged ions to achieve higher effective ion energies with a fixed acceleration potential has not been common for implantation users in the semiconductor industry. Energy purity is compromised primarily by charge exchange in the implanter beamline, caused by neutral gas originating from the ion source extraction aperture. Beam current has been an issue, since traditional implanter ion sources, such as the Freeman source, produce very limited currents of multiply charged species. At low beam currents, the implanter is not economical to use, hence the lack of commercial use of multiply charged ion implantation. Ion sources that address these issues must also meet requirements for adequate source lifetime, simplicity of operation (for computer control) and maintenance, and low cost of ownership. This paper details beam energy purity and usable beam currents for a new medium current Bernas ion source as compared to a standard Freeman ion source. The results show significant performance improvements, while also increasing the ion source lifetime.

  4. Ion Beam Induced Charge analysis of diamond diodes

    NASA Astrophysics Data System (ADS)

    Lehnert, J.; Meijer, J.; Ronning, C.; Spemann, D.; Vittone, E.

    2017-08-01

    Diamond based p-i-n light-emitting diodes, developed to electrically drive single-photon sources in the visible spectral region at room temperature, have the potential to play a key role in quantum based technologies. In order to gain more insight into the charge injection mechanism occurring in these diodes, we carried out an experiment aimed to investigate the electrostatics and the charge carrier transport by the Ion Beam Induced Charge (IBIC) technique, using 1 MeV He microbeam raster scanning of p-i-n structures fabricated in a high purity diamond substrate, using lithographic masking and P and B ion implantation doping. Charge Collection Efficiency (CCE) maps obtained at low ion fluence, show that induced charge pulses arise only from the P-implanted region, whereas no IBIC signals arise from the B-implanted region. This result suggests the formation of a slightly p-type doped substrate, forming a n+-p-p+, rather than the expected p-i-n, structure. However, for high fluence scans of small areas covering the intrinsic gap, CCE maps are more uniform and compatible with a p-i-n structure, suggesting the occurrence of a ;priming effect;, which saturates acceptor levels resulting in a decrease of the effective doping of the diamond substrate.

  5. Theory of a stationary microwave discharge with multiply charged ions in an expanding gas jet

    NASA Astrophysics Data System (ADS)

    Shalashov, A. G.; Abramov, I. S.; Golubev, S. V.; Gospodchikov, E. D.

    2016-08-01

    The formation of a jet of a nonequilibrium multiply charged ion plasma is studied in the inhomogeneous gas jet. It is shown that the geometrical divergence of the jet restricts the maximum ion charge state and results in the spatial localization of the discharge. Stationary solutions corresponding to such regimes are constructed. The model proposed can be used to optimize modern experiments on generation of hard UV radiation due to the line emission of multiply ionized atoms in a gas jet heated by high-power millimeter and submillimeter radiation.

  6. Theory of a stationary microwave discharge with multiply charged ions in an expanding gas jet

    SciTech Connect

    Shalashov, A. G. Abramov, I. S.; Golubev, S. V.; Gospodchikov, E. D.

    2016-08-15

    The formation of a jet of a nonequilibrium multiply charged ion plasma is studied in the inhomogeneous gas jet. It is shown that the geometrical divergence of the jet restricts the maximum ion charge state and results in the spatial localization of the discharge. Stationary solutions corresponding to such regimes are constructed. The model proposed can be used to optimize modern experiments on generation of hard UV radiation due to the line emission of multiply ionized atoms in a gas jet heated by high-power millimeter and submillimeter radiation.

  7. Chemical Noise Reduction via Mass Spectrometry and Ion/Ion Charge Inversion: Amino Acids

    PubMed Central

    Hassell, Kerry M.; LeBlanc, Yves C.; McLuckey, Scott A.

    2011-01-01

    Charge inversion ion/ion reactions can provide a significant reduction in chemical noise associated with mass spectra derived from complex mixtures for species comprised of both acidic and basic sites, provided the ions derived from the matrix largely undergo neutralization. Amino acids constitute an important class of amphoteric compounds that undergo relatively efficient charge inversion. Precipitated plasma constitutes a relatively complex biological matrix that yields detectable signals at essentially every mass-to-charge value over a wide range. This chemical noise can be dramatically reduced by using multiply-charged reagent ions that can invert the charge of species amenable to the transfer of multiple charges upon a single interaction and by detecting product ions of opposite polarity. The principle is illustrated here with amino acids present in precipitated plasma subjected to ionization in the positive mode, reaction with anions derived from negative nano-electrospray ionization of poly (amido amine) dendrimer generation 3.5, and mass analysis in the negative ion mode. PMID:21456599

  8. Photodissociation and charge transfer dynamics of negative ions studied with femtosecond photoelectron spectroscopy

    SciTech Connect

    Zanni, Martin Thomas

    1999-12-01

    This dissertation presents studies aimed at understanding the potential energy surfaces and dynamics of isolated negative ions, and the effects of solvent on each. Although negative ions play important roles in atmospheric and solution phase chemistry, to a large extent the ground and excited state potential energy surfaces of gas phase negative ions are poorly characterized, and solvent effects even less well understood. In an effort to fill this gap, the author's coworkers and the author have developed a new technique, anion femtosecond photoelectron spectroscopy, and applied it to gas phase photodissociation and charge transfer processes. Studies are presented that (1) characterize the ground and excited states of isolated and clustered anions, (2) monitor the photodissociation dynamics of isolated and clustered anions, and (3) explore the charge-transfer-to-solvent states of atomic iodide clustered with polar and non-polar solvents.

  9. Systematics of heavy-ion charge-exchange straggling

    NASA Astrophysics Data System (ADS)

    Sigmund, P.; Schinner, A.

    2016-10-01

    The dependence of heavy-ion charge-exchange straggling on the beam energy has been studied theoretically for several ion-target combinations. Our previous work addressed ions up to krypton, while the present study focuses on heavier ions, especially uranium. Particular attention has been paid to a multiple-peak structure which has been predicted theoretically in our previous work. For high-Z1 and high-Z2 systems, exemplified by U in Au, we identify three maxima in the energy dependence of charge-exchange straggling, while the overall magnitude is comparable with that of collisional straggling. Conversely, for U in C, charge-exchange straggling dominates, but only two peaks lie in the energy range where we presently are able to produce credible predictions. For U-Al we find good agreement with experiment in the energy range around the high-energy maximum. The position of the high-energy peak - which is related to processes in the projectile K shell - is found to scale as Z12, in contrast to the semi-empirical Z13/2 dependence proposed by Yang et al. Measurements for heavy ions in heavy targets are suggested in order to reconcile a major discrepancy between the present calculations and the frequently-used formula by Yang et al.

  10. 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+.

  11. Charge transfer states of the reaction center

    NASA Astrophysics Data System (ADS)

    Scherer, P. O. J.; Fischer, Sighart F.

    1998-08-01

    The energies of the low lying charge transfer states relevant for the photoinduced charge separation are analysed for Rps. viridis. The main prosthetic groups consisting of the special pair dimer P, the two adjacent monomers BL, and BM and the two pheophytines HL and HM are treated together with the surrounding residues quantum mechanically within a supermolecule approach on the basis of an INDO approximation. High order configuration interactions are incorporated to account for polarization effects and long range electrostatic effects of the protein are considered. The results are analyzed with regard to symmetry breaking effects between the L- and the M-branch. Internal reorganization effects within the dimer are also discussed.

  12. Charged particles and cluster ions produced during cooking activities.

    PubMed

    Stabile, L; Jayaratne, E R; Buonanno, G; Morawska, L

    2014-11-01

    Previous studies showed that a significant number of the particles present in indoor air are generated by cooking activities, and measured particle concentrations and exposures have been used to estimate the related human dose. The dose evaluation can be affected by the particle charge level which is usually not considered in particle deposition models. To this purpose, in this paper we show, for the very first time, the electric charge of particles generated during cooking activities and thus extending the interest on particle charging characterization to indoor micro-environments, so far essentially focused on outdoors. Particle number, together with positive and negative cluster ion concentrations, was monitored using a condensation particle counter and two air ion counters, respectively, during different cooking events. Positively-charged particle distribution fractions during gas combustion, bacon grilling, and eggplant grilling events were measured by two Scanning Mobility Particle Sizer spectrometers, used with and without a neutralizer. Finally, a Tandem Differential Mobility Analyzer was used to measure the charge specific particle distributions of bacon and eggplant grilling experiments, selecting particles of 30, 50, 80 and 100 nm in mobility diameter. The total fraction of positively-charged particles was 4.0%, 7.9%, and 5.6% for gas combustion, bacon grilling, and eggplant grilling events, respectively, then lower than other typical outdoor combustion-generated particles.

  13. Negative ion-uranium hexafluoride charge transfer reactions

    NASA Astrophysics Data System (ADS)

    Streit, Gerald E.; Newton, T. W.

    1980-10-01

    The flowing afterglow technique has been used to study the process of charge transfer from selected negative ions (F-, Cl-, Br-, I-, SF6-) to UF6. The sole ionic product in all cases was observed to be UF6-. Data analysis was complicated by an unexpected coupling of chemical and diffusive ion loss processes when UF6- product ions were present. The rate coefficients for the charge transfer processes are (k in 10-9 cm3 molecule-1 s-1) F-, 1.3; Cl-, 1.1; Br-, 0.93; I-, 0.77; and SF6-, 0.69. The rate constants agree quite well with the classical Langevin predictions.

  14. Lithium-ion battery aging mechanisms and life model under different charging stresses

    NASA Astrophysics Data System (ADS)

    Gao, Yang; Jiang, Jiuchun; Zhang, Caiping; Zhang, Weige; Ma, Zeyu; Jiang, Yan

    2017-07-01

    The charging time-consuming and lifespan of lithium-ion batteries have always been the bottleneck for the tremendous application of electric vehicles. In this paper, cycle life tests are conducted to reveal the influence of different charging current rates and cut-off voltages on the aging mechanism of batteries. The long-term effects of charging current rates and cut-off voltages on capacity degradation and resistance increase are compared. The results show that there exists a critical charging current and a critical charging cut-off voltage. When the charging stress exceeds the critical value, battery degradation speed will be greatly accelerated. Furthermore, battery aging mechanisms at various charging currents and cut-off voltages are investigated using incremental capacity analysis. It is indicated that charging current and cut-off voltage should be reduced to retard battery degradation when the battery degrades to a certain extent. The time when the loss of electrode material accelerates is taken as the crisis to reduce charging current and the time when the loss of lithium inventory accelerates is taken as the crisis to reduce charging cut-off voltage. Moreover, an experiential model quantitatively describing the relationship between capacity degradation rate and charging stresses at different aging states is established.

  15. Generation of highly charged peptide and protein ions by atmospheric pressure matrix-assisted infrared laser desorption/ionization ion trap mass spectrometry.

    PubMed

    König, Simone; Kollas, Oliver; Dreisewerd, Klaus

    2007-07-15

    We show that highly charged ions can be generated if a pulsed infrared laser and a glycerol matrix are employed for atmospheric pressure matrix-assisted laser desorption/ionization mass spectrometry with a quadrupole ion trap. Already for small peptides like bradykinin, doubly protonated ions form the most abundant analyte signal in the mass spectra. The center of the charge-state distribution increases with the size of the analyte. For example, insulin is detected with a most abundant ion signal corresponding to a charge state of four, whereas for cytochrome c, the 10 times protonated ion species produces the most intense signal. Myoglobin is observed with up to 13 charges. The high m/z ratios allow us to use the Paul trap for the detection of MALDI-generated protein ions that are, owing to their high molecular weight, not amenable in their singly protonated charge state. Formation of multiple charges critically depends on the addition of diluted acid to the analyte-matrix solution. Tandem mass spectra generated by collision-induced dissociation of doubly charged peptides are also presented. The findings allow speculations about the involvement of electrospray ionization processes in these MALDI experiments.

  16. On the formation of highly charged gaseous ions from unfolded proteins by electrospray ionization.

    PubMed

    Konermann, Lars; Rodriguez, Antony D; Liu, Jiangjiang

    2012-08-07

    Electrospray ionization (ESI) of native proteins results in a narrow distribution of low protonation states. ESI for these folded species proceeds via the charged residue mechanism. In contrast, ESI of unfolded proteins yields a wide distribution of much higher charge states. The current work develops a model that can account for this effect. Recent molecular dynamics simulations revealed that ESI for unfolded polypeptide chains involves protein ejection from nanodroplets, representing a type of ion evaporation mechanism (IEM). We point out the analogies between this IEM, and the dissociation of gaseous protein complexes after collisional activation. The latter process commences with unraveling of a single subunit, in concert with Coulombically driven proton transfer. The subunit then separates from the residual complex as a highly charged ion. We propose that similar charge equilibration events accompany the IEM of unfolded proteins, thereby causing the formation of high ESI charge states. A bead chain model is used for examining how charge is partitioned as protein and droplet separate. It is shown that protein ejection from differently sized ESI droplets generates a range of protonation states. The predicted behavior agrees well with experimental data.

  17. Contribution of charge-transfer processes to ion-induced electron emission

    SciTech Connect

    Roesler, M.

    1996-12-01

    Charge changing events of ions moving inside metals are shown to contribute significantly to electron emission in the intermediate velocity regime via electrons coming from projectile ionization. Inclusion of equilibrium charge state fractions, together with two-electron Auger processes and resonant-coherent electron loss from the projectile, results in reasonable agreement with previous calculations for frozen protons, though a significant part of the emission is now interpreted in terms of charge exchange. The quantal character of the surface barrier transmission is shown to play an important role. The theory compares well with experimental observations for {ital H} projectiles. {copyright} {ital 1996 The American Physical Society.}

  18. SMILETRAP—A Penning trap facility for precision mass measurements using highly charged ions

    NASA Astrophysics Data System (ADS)

    Bergström, I.; Carlberg, C.; Fritioff, T.; Douysset, G.; Schönfelder, J.; Schuch, R.

    2002-07-01

    The precision of mass measurements in a Penning trap increases linearly with the charge of the ion. Therefore we have attached a Penning trap, named SMILETRAP, to the electron beam ion source CRYSIS at MSL. CRYSIS is via an isotope separator connected to an ion source that can deliver singly charged ions of practically any element. In CRYSIS charge state breeding occurs by intense electron bombardment. We have shown that it is possible to produce, catch and measure the cyclotron frequencies of ions in the charge region 1+ to 52+. The relevant observable in mass measurements using a Penning trap is the ratio of the cyclotron frequencies of the ion of interest and ion used as a mass reference. High precision requires that the two frequencies are measured after one another in the shortest possible time. For reasons of convenience the precision trap operates at room temperature. So far it has been believed that warm traps working at 4 K are required for high mass precision with exactly one ion in the trap at a time. In this paper we demonstrate that mass precision of a few parts in 10 10 also can be obtained in a warm trap at a pressure of about 5×10 -12 mbar by stabilizing the pressure in the He-dewar, the trap temperature and the frequency synthesizer. In order to reduce the influence of changes of the magnetic field to a level below 10 -10, the scanning of the frequencies close to the resonances of both the ion of interest and the reference ion is done in a total time <2 min. Trapping of ions is a statistical procedure, allowing more than one ion to be trapped in each measurement cycle. However, after completing the measurements it is possible to reject all information except for events based on 1 and 2 trapped ions. The procedures of producing, transporting, catching, exciting and measuring the cyclotron resonance frequencies of highly charged ions and the mass reference ions with the time-of-flight method are described. In routine measurements with 1 s excitation

  19. Charge transfer during low energy metal/semiconductor ion-surface interactions

    NASA Astrophysics Data System (ADS)

    Chen, Xiaojian

    Ion-surface charge exchange is a central process in many surface analysis techniques and technical processes. Previous ion scattering studies have extensively investigated the interactions between alkali/noble gas ions and surfaces. Investigations of the interactions between metal/semiconductor ions and metal surfaces have seldom been reported, although they are of central importance in understanding processes involving the removal material from metal/semiconductor surfaces. This dissertation uses low energy ion scattering and direct recoil to reveal charge transfer mechanisms between metal/semiconductor atomic particles and clean and adsorb ate-covered Al and Si surfaces. All involved experiments were performed in ultra-high vacuum. Charge transfer between an Al atom and an Al surface is studied by producing energetic recoiled Al from a Al(100) surface via Xe+ bombardment. The measured neutral fractions of the recoils show that resonant charge transfer (RCT) is a key mechanism. The ion formation of recoiled and sputtered atoms can be both described by RCT. The characteristic difference between recoiled and sputtered atoms is interpreted as due to different surface conditions at the time of ion emission. 1˜5 keV Si+ ions were incident on atomically clean Al(100) surface. All scattered Si was neutralized, while Al ions were found in multi-charged states. In contrast to the traditional sputtering studies, there is an abnormally high yield of Al2+ and Al3+. The multiply charged ions are attributed to the charge promotion of Al 2p level during the electronically nearly-symmetric Si-Al collision, and subsequent shake-off processes. This mechanism is supported by the energy dependence of Al ions as well as ion induced Auger electrons. Si+ ions were scattered from submonolayers of Cs deposited onto Al(100). Because of the high ionization energy of Si, resonant charge transfer would be expected to completely neutralize the scattered projectiles. In contrast, a

  20. High resolution charge spectroscopy of heavy ions with FNTD technology

    NASA Astrophysics Data System (ADS)

    Bartz, J. A.; Kodaira, S.; Kurano, M.; Yasuda, N.; Akselrod, M. S.

    2014-09-01

    This paper is focused on the improvement of the heavy charge particle charge resolution of Fluorescent Nuclear Track Detector (FNTD) technology. Fluorescent intensity of individual heavy charge particle tracks is used to construct the spectrum. Sources of spectroscopic line broadening were investigated and several fluorescent intensity correction procedures were introduced to improve the charge resolution down to δZ = 0.25 c.u. and enable FNTD technology to distinguish between all projectile fragments of 290 MeV carbon ions. The benefits of using FNTD technology for fragmentation study include large dynamic range and wide angular acceptance. While we describe these developments in the context of fragmentation studies, the same techniques are readily extended to FNTD LET spectroscopy in general.

  1. Supercharging with m-nitrobenzyl alcohol and propylene carbonate: forming highly charged ions with extended, near-linear conformations.

    PubMed

    Going, Catherine C; Williams, Evan R

    2015-04-07

    The effectiveness of the supercharging reagents m-nitrobenzyl alcohol (m-NBA) and propylene carbonate at producing highly charged protein ions in electrospray ionization is compared. Addition of 5% m-NBA or 15% propylene carbonate increases the average charge of three proteins by ∼21% or ∼23%, respectively, when these ions are formed from denaturing solutions (water/methanol/acetic acid). These results indicate that both reagents are nearly equally effective at supercharging when used at their optimum concentrations. A narrowing of the charge state distribution occurs with both reagents, although this effect is greater for propylene carbonate. Focusing the ion signal into fewer charge states has the advantage of improving sensitivity. The maximum charge state of ubiquitin formed with propylene carbonate is 21+, four charges higher than previously reported. Up to nearly 30% of all residues in a protein can be charged, and the collisional cross sections of the most highly charged ions of both ubiquitin and cytochrome c formed with these supercharging reagents were measured for the first time and found to be similar to those calculated for theoretical highly extended, linear or near-linear conformations. Under native supercharging conditions, m-NBA is significantly more effective at producing high charge states than propylene carbonate.

  2. Aerosol Charging by Ion Attachment and Electrical Conductivity in the Lower Atmosphere of Mars

    NASA Astrophysics Data System (ADS)

    Tripathi, S. N.; Michael, M.

    2007-12-01

    Aerosol in the atmosphere of Mars is a topic of considerable interest since their effect on the climate has been recognized. The aerosols interact with both visible and infrared radiation and modify atmospheric heating rates which are responsible for the atmospheric circulation, dust storms etc. In the present work, the charging of aerosols and the conductivity of the lower atmosphere of Mars during the day and night-time are calculated. Galactic cosmic rays are the dominant ionizing process in the lower atmosphere producing molecular ions and ion clusters. These ion clusters get attached to the aerosols and charging occurs during the night-time. Solar UV photons are an additional ionizing agent during the day-time. Solar photons of energy less than 6 eV reach the surface of Mars as those with energies greater than 6 eV are absorbed by the atmospheric molecules before they reach the lower atmosphere. Those photons, which reach the lower atmosphere, ionize the aerosols as the ionization potential of most of the aerosols is less than 6 eV and produce electrons. Aerosols become charged by the attachment of ions and electrons during the day-time. The ion-aerosol and electron-aerosol attachment coefficients are calculated. The neutral atmospheric properties required to calculate the aerosol charging and the conductivity are obtained from Magalhaes et al. (1999). The aerosols have a concentration and effective radius of 2.26 cm-3 and 1.9 mm, respectively, at the surface. The charge distribution of aerosols is obtained by the simultaneous solution of the ion-electron-aerosol charge balance equations. Both the steady state and time dependent concentration of charged aerosols are calculated. It was observed that about 80% of the aerosols close to the surface become charged during the night-time (Michael et al., 2007). In addition to ions, electrons are also present during the day-time. More charging occurs and most of the aerosols become charged during the day-time. The

  3. A compact source for bunches of singly charged atomic ions

    SciTech Connect

    Murböck, T.; Birkl, G.; Schmidt, S.; Nörtershäuser, W.; Andelkovic, Z.; Vogel, M.

    2016-04-15

    We have built, operated, and characterized a compact ion source for low-energy bunches of singly charged atomic ions in a vacuum beam line. It is based on atomic evaporation from an electrically heated oven and ionization by electron impact from a heated filament inside a grid-based ionization volume. An adjacent electrode arrangement is used for ion extraction and focusing by applying positive high-voltage pulses to the grid. The method is particularly suited for experimental environments which require low electromagnetic noise. It has proven simple yet reliable and has been used to produce μs-bunches of up to 10{sup 6} Mg{sup +} ions at a repetition rate of 1 Hz. We present the concept, setup and characterizing measurements. The instrument has been operated in the framework of the SpecTrap experiment at the HITRAP facility at GSI/FAIR to provide Mg{sup +} ions for sympathetic cooling of highly charged ions by laser-cooled {sup 24}Mg{sup +}.

  4. A compact source for bunches of singly charged atomic ions.

    PubMed

    Murböck, T; Schmidt, S; Andelkovic, Z; Birkl, G; Nörtershäuser, W; Vogel, M

    2016-04-01

    We have built, operated, and characterized a compact ion source for low-energy bunches of singly charged atomic ions in a vacuum beam line. It is based on atomic evaporation from an electrically heated oven and ionization by electron impact from a heated filament inside a grid-based ionization volume. An adjacent electrode arrangement is used for ion extraction and focusing by applying positive high-voltage pulses to the grid. The method is particularly suited for experimental environments which require low electromagnetic noise. It has proven simple yet reliable and has been used to produce μs-bunches of up to 10(6) Mg(+) ions at a repetition rate of 1 Hz. We present the concept, setup and characterizing measurements. The instrument has been operated in the framework of the SpecTrap experiment at the HITRAP facility at GSI/FAIR to provide Mg(+) ions for sympathetic cooling of highly charged ions by laser-cooled (24)Mg(+).

  5. Studies of Ion Beam Charge Neutralization by Ferroelectric Plasma Sources

    NASA Astrophysics Data System (ADS)

    Stepanov, A.; Gilson, E. P.; Grisham, L.; Davidson, R. C.

    2013-10-01

    Space-charge forces limit the possible transverse compression of high perveance ion beams that are used in ion-beam-driven high energy density physics applications; the minimum radius to which a beam can be focused is an increasing function of perveance. The limit can be overcome if a plasma is introduced in the beam path between the focusing element and the target in order to neutralize the space charge of the beam. This concept has been implemented on the Neutralized Drift Compression eXperiment (NDCX) at LBNL using Ferroelectric Plasma Sources (FEPS). In our experiment at PPPL, we propagate a perveance-dominated ion beam through a FEPS to study the effect of the neutralizing plasma on the beam envelope and its evolution in time. A 30-60 keV space-charge-dominated Argon beam is focused with an Einzel lens into a FEPS located at the beam waist. The beam is intercepted downstream from the FEPS by a movable Faraday cup that provides time-resolved 2D current density profiles of the beam spot on target. We report results on: (a) dependence of charge neutralization on FEPS plasma density; (b) effects on beam emittance, and (c) time evolution of the beam envelope after the FEPS pulse. Research supported by the U.S. Department of Energy.

  6. Charge collection efficiency degradation induced by MeV ions in semiconductor devices: Model and experiment

    DOE PAGES

    Vittone, Ettore; Pastuovic, Zeljko; Breese, Mark B. H.; ...

    2016-02-08

    This study investigates both theoretically and experimentally the charge collection efficiency (CCE) degradation in silicon diodes induced by energetic ions. Ion Beam Induced Charge (IBIC) measurements carried out on n- and p-type silicon diodes which were previously irradiated with MeV He ions show evidence that the CCE degradation does not only depend on the mass, energy and fluence of the damaging ion, but also depends on the ion probe species and on the polarization state of the device. A general one-dimensional model is derived, which accounts for the ion-induced defect distribution, the ionization profile of the probing ion and themore » charge induction mechanism. Using the ionizing and non-ionizing energy loss profiles resulting from simulations based on the binary collision approximation and on the electrostatic/transport parameters of the diode under study as input, the model is able to accurately reproduce the experimental CCE degradation curves without introducing any phenomenological additional term or formula. Although limited to low level of damage, the model is quite general, including the displacement damage approach as a special case and can be applied to any semiconductor device. It provides a method to measure the capture coefficients of the radiation induced recombination centres. They can be considered indexes, which can contribute to assessing the relative radiation hardness of semiconductor materials.« less

  7. Charge collection efficiency degradation induced by MeV ions in semiconductor devices: Model and experiment

    SciTech Connect

    Vittone, Ettore; Pastuovic, Zeljko; Breese, Mark B. H.; Lopez, Javier Garicia; Jaksic, Milko; Raisanen, Jyrki; Siegele, Rainer; Simon, Aliz; Vizkelethy, Gyorgy

    2016-02-08

    This study investigates both theoretically and experimentally the charge collection efficiency (CCE) degradation in silicon diodes induced by energetic ions. Ion Beam Induced Charge (IBIC) measurements carried out on n- and p-type silicon diodes which were previously irradiated with MeV He ions show evidence that the CCE degradation does not only depend on the mass, energy and fluence of the damaging ion, but also depends on the ion probe species and on the polarization state of the device. A general one-dimensional model is derived, which accounts for the ion-induced defect distribution, the ionization profile of the probing ion and the charge induction mechanism. Using the ionizing and non-ionizing energy loss profiles resulting from simulations based on the binary collision approximation and on the electrostatic/transport parameters of the diode under study as input, the model is able to accurately reproduce the experimental CCE degradation curves without introducing any phenomenological additional term or formula. Although limited to low level of damage, the model is quite general, including the displacement damage approach as a special case and can be applied to any semiconductor device. It provides a method to measure the capture coefficients of the radiation induced recombination centres. They can be considered indexes, which can contribute to assessing the relative radiation hardness of semiconductor materials.

  8. Proceedings of the workshop on opportunities for atomic physics using slow, highly-charged ions

    SciTech Connect

    Not Available

    1987-01-01

    The study of atomic physics with highly-charged ions is an area of intense activity at the present time because of a convergence of theoretical interest and advances in experimental techniques. The purpose of the Argonne ''Workshop on Opportunities for Atomic Physics Using Slow, Highly-Charged Ions'' was to bring together atomic, nuclear, and accelerator physicists in order to identify what new facilities would be most useful for the atomic physics community. The program included discussion of existing once-through machines, advanced ion sources, recoil ion techniques, ion traps, and cooler rings. One of the topics of the Workshop was to discuss possible improvement to the ANL Tandem-Linac facility (ATLAS) to enhance the capability for slowing down ions after they are stripped to a high-charge state (the Accel/Decel technique). Another topic was the opportunity for atomic physics provided by the ECR ion source which is being built for the Uranium Upgrade of ATLAS. 18 analytics were prepared for the individual papers in this volume.

  9. Study on space charge effect in an electrostatic ion analyzer applied to measure laser produced ions

    SciTech Connect

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

    2014-03-15

    The abundance of different ions produced by laser ion sources is usually analyzed by an electrostatic ion analyzer (EIA). Ion current intensities in the range of several mA/cm{sup 2} at the position of the EIA have been achieved from the laser ion source developed by the Institute of Modern Physics; this indicates that a noticeable influence of space charge effect during the ion transmission will occur. Hence, while the parameters of the EIA or the beams are changed, such as ion species, current intensity, the ions’ transmission efficiency through the EIA is different, which will result in an uncertainty in the estimation of the ions’ yields. Special attention is focused on this issue in this paper. Ion's transmissions through the EIA under different circumstances are studied with simulations and experiments, the results of which are consistent with each other.

  10. Ionization efficiency studies with charge breeder and conventional electron cyclotron resonance ion source

    SciTech Connect

    Koivisto, H. Tarvainen, O.; Toivanen, V.; Komppula, J.; Kronholm, R.; Lamy, T.; Angot, J.; Delahaye, P.; Maunoury, L.; Patti, G.; Standylo, L.; Steczkiewicz, O.; Choinski, J.

    2014-02-15

    Radioactive Ion Beams play an increasingly important role in several European research facility programs such as SPES, SPIRAL1 Upgrade, and SPIRAL2, but even more for those such as EURISOL. Although remarkable advances of ECRIS charge breeders (CBs) have been achieved, further studies are needed to gain insight on the physics of the charge breeding process. The fundamental plasma processes of charge breeders are studied in the frame of the European collaboration project, EMILIE, for optimizing the charge breeding. Important information on the charge breeding can be obtained by conducting similar experiments using the gas mixing and 2-frequency heating techniques with a conventional JYFL 14 GHz ECRIS and the LPSC-PHOENIX charge breeder. The first experiments were carried out with noble gases and they revealed, for example, that the effects of the gas mixing and 2-frequency heating on the production of high charge states appear to be additive for the conventional ECRIS. The results also indicate that at least in the case of noble gases the differences between the conventional ECRIS and the charge breeder cause only minor impact on the production efficiency of ion beams.

  11. Charge-exchange plasma generated by an ion thruster

    NASA Technical Reports Server (NTRS)

    Kaufman, H. R.

    1975-01-01

    The use of high voltage solar arrays greatly reduces or eliminates power processing requirements in space electric propulsion systems. This use also requires substantial areas of solar array to be at high positive potential relative to space and most of the spacecraft. The charge exchange plasma conducts electrons from the ion beam to such positive surfaces, and thereby electrically load the high voltage solar array. To evaluate this problem, the charge-exchange plasma generated by an ion beam was investigated experimentally. Based upon the experimental data, a simple model was derived for the charge-exchange plasma. This model is conservative in the sense that both the electron/ion density and the electron current density should be equal to, or less than, the preducted value for all directions in the hemisphere upstream of the ion beam direction. Increasing the distance between a positive potential surface (such as a high voltage solar array) and the thruster is the simplest way to control interactions. Both densities and currents vary as the inverse square of this distance.

  12. ECR plasma source for heavy ion beam charge neutralization

    SciTech Connect

    Efthimion, P.C.; Gilson, E.; Grisham, L.; Kolchin, P.; Davidson, E.C.; Yu, S.S.; Logan, B.G.

    2002-05-01

    Highly ionized plasmas are being considered as a medium for charge neutralizing heavy ion beams in order to focus beyond the space-charge limit. Calculations suggest that plasma at a density of 1-100 times the ion beam density and at a length {approx} 0.1-2 m would be suitable for achieving a high level of charge neutralization. An ECR source has been built at the Princeton Plasma Physics Laboratory (PPPL) to support a joint Neutralized Transport Experiment (NTX) at the Lawrence Berkeley National Laboratory (LBNL) to study ion beam neutralization with plasma. The ECR source operates at 13.6 MHz and with solenoid magnetic fields of 1-10 gauss. The goal is to operate the source at pressures {approx} 10{sup -6} Torr at full ionization. The initial operation of the source has been at pressures of 10{sup -4}-10{sup -1} Torr. Electron densities in the range of 10{sup 8}-10{sup 11} cm{sup -3} have been achieved. Low-pressure operation is important to reduce ion beam ionization. A cusp magnetic field has been installed to improve radial confinement and reduce the field strength on the beam axis. In addition, axial confinement is believed to be important to achieve lower-pressure operation. To further improve breakdown at low pressure, a weak electron source will be placed near the end of the ECR source.

  13. Molecular Bound States of Supercritical Charged Impurities on Graphene

    NASA Astrophysics Data System (ADS)

    Velizhanin, Kirill; Adamska, Lyudmyla; Solenov, Dmitry

    2015-03-01

    Functionalization of graphene by chemical groups/atoms allows one to tune its electronic, chemical and mechanical properties. For example, metallic adatoms (e.g., Li, Ca, Y) can be important in applications ranging from hydrogen storage to superconductivity. Such adatoms bind ionically to graphene and the resulting positive ions move along graphene relatively freely, so understanding the energetics of their interaction with graphene and between each other becomes critical for assessing stability of resulting materials in practical applications. It has recently been demonstrated that ions with charge greater than Z ~ 1 induce a very peculiar non-linear electronic polarization of graphene, which is reminiscent to the Dirac vacuum reconstruction around superheavy nuclei. In our work we demonstrate that such non-linear polarization qualitatively changes not only graphene electronic structure but also the energetics of the effective graphene-mediated interaction between such ions. In my talk, I will discuss the properties of such effective interaction and its dependence on various parameters of the system. In particular, I will report on our finding that molecular bound states of supercritically charged ions can be formed on graphene at certain conditions. This work was performed under the NNSA of the U.S. DOE at LANL under Contract No. DE-AC52-06NA25396.

  14. Doubly-charged ions in the planetary ionospheres: a review.

    PubMed

    Thissen, Roland; Witasse, Olivier; Dutuit, Odile; Wedlund, Cyril Simon; Gronoff, Guillaume; Lilensten, Jean

    2011-11-07

    This paper presents a review of the current knowledge on the doubly-charged atomic and molecular positive ions in the planetary atmospheres of the Solar System. It is focused on the terrestrial planets which have a dense atmosphere of N(2) or CO(2), i.e. Venus, the Earth and Mars, but also includes Titan, the largest satellite of Saturn, which has a dense atmosphere composed mainly of N(2) and a few percent of methane. Given the composition of these neutral atmospheres, the following species are considered: C(++), N(++), O(++), CH(4)(++), CO(++), N(2)(++), NO(++), O(2)(++), Ar(++) and CO(2)(++). We first discuss the status of their detection in the atmospheres of planets. Then, we provide a comprehensive review of their complex and original photochemistry, production and loss processes. Synthesis tables are provided for those ions, while a discussion on individual species is also provided. Methods for detecting doubly-charged ions in planetary atmospheres are presented, namely with mass-spectrometry, remote sensing and fine plasma density measurements. A section covers some original applications, like the possible effect of the presence of doubly-charged ions on the escape of an atmosphere, which is a key topic of ongoing planetary exploration, related to the evolution of a planet. The results of models, displayed in a comparative way for Venus, Earth, Mars and Titan, are discussed, as they can predict the presence of doubly-charged ions and will certainly trigger new investigations. Finally we give our view concerning next steps, challenges and needs for future studies, hoping that new scientific results will be achieved in the coming years and feed the necessary interdisciplinary exchanges amongst different scientific communities.

  15. 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.

  16. Charge exchange between low energy Si ions and Cs adatoms

    NASA Astrophysics Data System (ADS)

    Chen, X.; Sroubek, Z.; Yarmoff, J. A.

    Unexpectedly large yields of positive and negative ions are produced when 2 and 5 keV Si + is singly scattered from Cs adatoms on Al(1 0 0) and Si(1 1 1). This is in contrast with Li +, in which case the ions are almost completely neutralized. The Si + ions likely result from valence electron resonant charge transfer (RCT) enhanced by promotion of the ionization level as it interacts with the Cs 5p level, but incomplete resonance neutralization of the incoming Si + cannot be absolutely excluded. The experimental data are quantitatively compared to the model and values of the microscopic parameters are estimated. Negative Si - ions are produced when the surface work function is very small, presumably by direct RCT to the projectile affinity level as it is bent downward by the image potential and by the dipole formed by the adsorbed Cs.

  17. The charge state of iron implanted into sapphire

    SciTech Connect

    McHargue, C.J.; Sklad, P.S.; White, C.W.; Farlow, G.C.; Perez, A.; Kornilios, N.; Marest, G.

    1987-08-01

    Several techniques (RBS, TEM, CEMS) have been used to characterize sapphire single crystals implanted with iron at room temperature to fluences of 10/sup 16/ to 10/sup 17/ ions cm/sup -2/. At low fluences the as-implanted iron is found mainly in the ferrous state. As the fluence is increased, Fe/sup 3 +/ and metallic iron clusters became dominant. There is a strong correlation between the probability of finding specific configurations of iron ions within four cation coordination shells and the relative amounts of each charge state observed. The superparamagnetic behavior of the clusters suggest that they are of the order of 2 nm in size but the large amount of irradiation-induced damage and residual stress has prevented their imaging by TEM. 13 refs., 7 figs.

  18. Modelling of charging effects in plasma immersion ion implantation

    NASA Astrophysics Data System (ADS)

    En, William; Cheung, Nathan W.

    1995-03-01

    The charging effects of plasma immersion ion implantation on several device structures is simulated. The simulations use an analytical model which couples the interaction of the plasma and IC devices during plasma implantation. The plasma model is implemented within the circuit simulator SPICE, which allows the model to uses all of the IC device models existing within SPICE. The model of the Fowler-Nordheim tunneling current through thin gate oxides of MOS devices is demonstrated, and shown how it can be used to quantify the damage induced. Charging damage is shown to be strongly affected by the device structure.

  19. Ions with low charges in the solar wind as measured by SWICS on board Ulysses. [Solar Wind Ion Composition Spectrometer

    NASA Technical Reports Server (NTRS)

    Geiss, J.; Ogilvie, K. W.; Von Steiger, R.; Mall, U.; Gloeckler, G.; Galvin, A. B.; Ipavich, F.; Wilken, B.; Gliem, F.

    1992-01-01

    We present new data on rare ions in the solar wind. Using the Ulysses-SWICS instrument with its very low background we have searched for low-charge ions during a 6-d period of low-speed solar wind and established sensitive upper limits for many species. In the solar wind, we found He(1+)/He(2+) of less than 5 x 10 exp -4. This result and the charge state distributions of heavier elements indicate that all components of the investigated ion population went through a regular coronal expansion and experienced the typical electron temperatures of 1 to 2 million Kelvin. We argue that the virtual absence of low-charge ions demonstrates a very low level of nonsolar contamination in the source region of the solar wind sample we studied. Since this sample showed the FlP effect typical for low-speed solar wind, i.e., an enhancement in the abundances of elements with low first ionization potential, we conclude that this enhancement was caused by an ion-atom separation mechanism operating near the solar surface and not by foreign material in the corona.

  20. Quantum-State-Resolved Ion-Molecule Chemistry

    NASA Astrophysics Data System (ADS)

    Chen, Gary; Yang, Tiangang; Campbell, Wesley; Hudson, Eric

    2016-05-01

    We propose a method to achieve quantum-state-resolved ion-molecule chemistry by utilizing cryogenic buffer gas cooling techniques and a combination of ion imaging and mass spectrometry of targets in an RF Paul trap. Cold molecular species produced by a cryogenic buffer gas beam (CBGB) are introduced to target ion species in an linear quadrupole trap (LQT) where ion imaging techniques and time of flight mass spectrometry (ToF) are then used to observe the target ions and the charged reaction products [1,2]. By taking advantage of the large ion-neutral interaction cross sections and characteristically long ion trap lifetimes, we can utilize the precision control over quantum states allowed by an ion trap to resolve state-to-state quantum chemical reactions without high-density molecular sample production, well within proposed capabilities. The combination of these two very general cold species production techniques allows for production and observation of a broad range of ion-neutral reactions. We initially plan to study chemical reactions between sympathetically cooled carbon ions (via laser cooled beryllium ions) with buffer gas cooled water. This work is supported by the US Air Force Office of Scientific Research.

  1. Dust negative ion acoustic shock waves in a dusty multi-ion plasma with positive dust charging current

    SciTech Connect

    Duha, S. S.

    2009-11-15

    Recent analysis of Mamun et al.[ Phys. Lett. A 373, 2355 (2009)], who considered electrons, light positive ions, heavy negative ions, and extremely massive (few micron size) charge fluctuating dust, has been extended by positive dust charging current, i.e., considering the charging currents for positively charged dust grains. A dusty multi-ion plasma system consisting of electrons, light positive ions, negative ions, and extremely massive (few micron size) charge fluctuating stationary dust have been considered. The electrostatic shock waves associated with negative ion dynamics and dust charge fluctuation have been investigated by employing the reductive perturbation method. It has been shown that the dust charge fluctuation is a source of dissipation and is responsible for the formation of dust negative ion acoustic (DNIA) shock structures. The basic features of such DNIA shock structures have been identified. The findings of this investigation may be useful in understanding the laboratory phenomena and space dusty plasmas.

  2. A multi time-scale state-of-charge and state-of-health estimation framework using nonlinear predictive filter for lithium-ion battery pack with passive balance control

    NASA Astrophysics Data System (ADS)

    Hua, Yin; Cordoba-Arenas, Andrea; Warner, Nicholas; Rizzoni, Giorgio

    2015-04-01

    With respect to cell-to-cell variation in battery packs for electric vehicles (EVs), the estimation of state of charge (SOC) and state of health (SOH) of battery systems remains a challenging problem that needs to be solved under the strict computational limitations of battery management system. This paper aims at proposing a stable and accurate SOC/SOH estimation framework for battery pack with multi-cells connected in series with passive balance control. First, the concepts of cell-level and pack-level state definitions, which clearly describe the relationship between the states of the battery cells and those of the battery pack, are introduced. Then a multi time-scale framework for estimating the SOC/SOH of pack is developed. Within the framework, the SOH values (slow dynamics) are estimated with long time interval, while the SOC (fast dynamics) is estimated in real-time. For the framework implementation, nonlinear predictive filter (NPF) is used as the estimation algorithm to provide accurate estimates of SOC and SOH. Finally, experiments are conducted on a battery pack under UDDS driving cycles to validate the performance of the proposed framework. The experimental validation indicates that the SOC and SOH of the battery pack can be accurately estimated using the proposed framework.

  3. Influence of solar wind ions on photoemission charging of dust

    NASA Astrophysics Data System (ADS)

    Nouzak, Libor; Richterova, Ivana; Pavlu, Jiri; Safrankova, Jana; Nemecek, Zdenek

    2016-04-01

    The lunar surface covered by a layer of dust grains is exposed to solar wind particles and photons coming from the Sun on the sunlit side. Solar wind ions cause sputtering of dust grains or can be implanted into grains. We suppose that as a consequence of ion implantation, an additional energy is transferred to grains, more valence band electrons are excited, and the photoelectron yield is increased. An increase of the photoelectron current causes the enhanced density of electrons that form a sheet above the illuminated lunar surface. Thus, an influence of solar wind ions on the Debye length and photoelectron sheet formation is expected. We present laboratory estimations of work functions and photoelectron yields of a single micron-sized silica grain before and after ion implantation. The silica grain used as a lunar simulant is caught in the electrodynamic trap. Grain's specific charge is evaluated by an analysis of the grain motion within the trap, while its work function is determined from observations of a time evolution of the charge-to-mass ratio when the grain is irradiated by photons of different emission lines. By comparison of the photoelectron current (from grain) with photon flux (from UV source), we establish the photoelectron yield of the trapped object. The influence of ion implantation is thoroughly analyzed and discussed.

  4. Molecular ion battery: a rechargeable system without using any elemental ions as a charge carrier

    PubMed Central

    Yao, Masaru; Sano, Hikaru; Ando, Hisanori; Kiyobayashi, Tetsu

    2015-01-01

    Is it possible to exceed the lithium redox potential in electrochemical systems? It seems impossible to exceed the lithium potential because the redox potential of the elemental lithium is the lowest among all the elements, which contributes to the high voltage characteristics of the widely used lithium ion battery. However, it should be possible when we use a molecule-based ion which is not reduced even at the lithium potential in principle. Here we propose a new model system using a molecular electrolyte salt with polymer-based active materials in order to verify whether a molecular ion species serves as a charge carrier. Although the potential of the negative-electrode is not yet lower than that of lithium at present, this study reveals that a molecular ion can work as a charge carrier in a battery and the system is certainly a molecular ion-based “rocking chair” type battery. PMID:26043147

  5. Molecular ion battery: a rechargeable system without using any elemental ions as a charge carrier.

    PubMed

    Yao, Masaru; Sano, Hikaru; Ando, Hisanori; Kiyobayashi, Tetsu

    2015-06-04

    Is it possible to exceed the lithium redox potential in electrochemical systems? It seems impossible to exceed the lithium potential because the redox potential of the elemental lithium is the lowest among all the elements, which contributes to the high voltage characteristics of the widely used lithium ion battery. However, it should be possible when we use a molecule-based ion which is not reduced even at the lithium potential in principle. Here we propose a new model system using a molecular electrolyte salt with polymer-based active materials in order to verify whether a molecular ion species serves as a charge carrier. Although the potential of the negative-electrode is not yet lower than that of lithium at present, this study reveals that a molecular ion can work as a charge carrier in a battery and the system is certainly a molecular ion-based "rocking chair" type battery.

  6. Formation of ion clusters in the phase separated structures of neutral-charged polymer blends

    NASA Astrophysics Data System (ADS)

    Kwon, Ha-Kyung; Olvera de La Cruz, Monica

    2015-03-01

    Polyelectrolyte blends, consisting of at least one charged species, are promising candidate materials for fuel cell membranes, for their mechanical stability and high selectivity for proton conduction. The phase behavior of the blends is important to understand, as this can significantly affect the performance of the device. The phase behavior is controlled by χN, the Flory-Huggins parameter multiplied by the number of mers, as well as the electrostatic interactions between the charged backbone and the counterions. It has recently been shown that local ionic correlations, incorporated via liquid state (LS) theory, enhance phase separation of the blend, even in the absence of polymer interactions. In this study, we show phase diagrams of neutral-charged polymer blends including ionic correlations via LS theory. In addition to enhanced phase separation at low χN, the blends show liquid-liquid phase separation at high electrostatic interaction strengths. Above the critical strength, the charged polymer phase separates into ion-rich and ion-poor regions, resulting in the formation of ion clusters within the charged polymer phase. This can be shown by the appearance of multiple spinodal and critical points, indicating the coexistence of several charge separated phases. This work was performed under the following financial assistance award 70NANB14H012 from U.S. Department of Commerce, National Institute of Standards and Technology as part of the Center for Hierarchical Materials Design (CHiMaD).

  7. Highly charged ions for atomic clocks, quantum information, and search for α variation.

    PubMed

    Safronova, M S; Dzuba, V A; Flambaum, V V; Safronova, U I; Porsev, S G; Kozlov, M G

    2014-07-18

    We propose 10 highly charged ions as candidates for the development of next generation atomic clocks, quantum information, and search for α variation. They have long-lived metastable states with transition wavelengths to the ground state between 170-3000 nm, relatively simple electronic structure, stable isotopes, and high sensitivity to α variation (e.g., Sm(14+), Pr(10+), Sm(13+), Nd(10+)). We predict their properties crucial for the experimental exploration and highlight particularly attractive systems for these applications.

  8. Single ion induced surface nanostructures: a comparison between slow highly charged and swift heavy ions.

    PubMed

    Aumayr, Friedrich; Facsko, Stefan; El-Said, Ayman S; Trautmann, Christina; Schleberger, Marika

    2011-10-05

    This topical review focuses on recent advances in the understanding of the formation of surface nanostructures, an intriguing phenomenon in ion-surface interaction due to the impact of individual ions. In many solid targets, swift heavy ions produce narrow cylindrical tracks accompanied by the formation of a surface nanostructure. More recently, a similar nanometric surface effect has been revealed for the impact of individual, very slow but highly charged ions. While swift ions transfer their large kinetic energy to the target via ionization and electronic excitation processes (electronic stopping), slow highly charged ions produce surface structures due to potential energy deposited at the top surface layers. Despite the differences in primary excitation, the similarity between the nanostructures is striking and strongly points to a common mechanism related to the energy transfer from the electronic to the lattice system of the target. A comparison of surface structures induced by swift heavy ions and slow highly charged ions provides a valuable insight to better understand the formation mechanisms.

  9. The Dynamics of Resonant Charge Transfer in Hyperthermal Energy Ion-Surface Collisions

    NASA Astrophysics Data System (ADS)

    Behringer, Ernest Robert

    I have studied the dynamics of resonant charge transfer in hyperthermal energy collisions of positively charged alkali ions with clean and alkali-covered Cu(001) surfaces. Li^+ ions incident on these surfaces may scatter into a variety of directions with different energies and in different charge states. To characterize the scattering from these surfaces, I have measured the in-plane energy and angular distributions of Li^+ scattered from the clean Cu(001) surface for incident energies of 400 and 100 eV and have reproduced these distributions with classical trajectory simulations which make use of a model ion-surface potential constructed from a sum of Hartree-Fock pair potentials and a long-ranged attractive potential. It is found that the scattering of lithium is more complex than for the other alkalis due to its small size, and that inelastic losses are appreciable for this system at the incident energies studies. The measurements of the scattering distractions provide useful information for the analysis of the charge transfer experiments. I have studied the dynamics of charge transfer by measuring the work function dependence of the absolute yields of different charge states and of the relative yields of excited states in the scattered flux that results when hyperthermal energy Li^+ ions impinge on clean and alkali-covered Cu(001). The data are compared to the predictions of a many-body charge transfer theory and it is found that all of the qualitative trends in the data are reproduced. Examination of the theoretical predictions shows that the dynamics of the charge transfer are complex and depend on the energies and lifetimes of all of the atomic states, even if these states are not found in the scattered flux. The theory also indicates that the dynamics depends on the relationship between the time scales set by the atomic state lifetimes and the velocity of the scattered particle, and predicts that most of the charge transferred from the mental to the atom is

  10. Charge exchange of low-energy ions in thin carbon foils

    NASA Technical Reports Server (NTRS)

    Buergi, Alfred; Oetliker, Michael; Bochsler, Peter; Geiss, Johannes; Coplan, Michael A.

    1990-01-01

    In order to calibrate a time-of-flight mass spectrometer which is to be flown in the solar wind, the charge exchange properties of low-energy ions in thin carbon foils have been investigated. Incident ions of He, C, N, O, Ne, and Ar with energies in the range 0.5-2 keV/nucleon have been used to measure charge-state distribution, residual energy, and angular distribution after transmission through thin (1-6 microgram/sq cm) carbon foils. Within such foils, an equilibrium between ionization and recombination of the projectile is rapidly established, and, consequently, the charge state of the emerging particle depends essentially on its residual velocity. A comparison of the charge exchange properties of Ne-22 with Ne-20 demonstrates that indeed the velocity (and not the energy) of the emerging particle determines its final charge. A comparison of properties of different elements provides an indication of an electron shell effect. Predictions for the energy loss of ions within the carbon foils made with the TRIM code are in good agreement with the experimental results presented in this paper.

  11. The g-factor of highly charged ions

    NASA Astrophysics Data System (ADS)

    Sturm, Sven; Köhler, Florian; Werth, Günter

    2015-04-01

    Highly charged ions provide a unique opportunity to test our understanding of atomic properties under extreme conditions: The electric field strength seen by an electron bound to a nucleus at the distance of the Bohr radius ranges from 1010 V/cm in hydrogen to1016 V/cm in hydrogenlike uranium. The theory of quantum electrodynamics (QED) allows for calculation e.g. of binding energies, transition probabilities or magnetic moments. While at low fields QED is tested to very high precision, new, hypothetical nonlinear effects like photon- photon interaction or a violation of Lorentz symmetry may occur in strong fields which then would lead to an extension of the Standard Model. The ultra-high precision determination of the magnetic moment of a bound electron in a highly charged ion provides a unique possibility to probe the validity of the current Standard Model in extreme conditions.

  12. UNIVERSAL BEHAVIOR OF CHARGED PARTICLE PRODUCTION IN HEAVY ION COLLISIONS.

    SciTech Connect

    STEINBERG,P.A.FOR THE PHOBOS COLLABORATION

    2002-07-24

    The PHOBOS experiment at RHIC has measured the multiplicity of primary charged particles as a function of centrality and pseudorapidity in Au+Au collisions at {radical}(s{sub NN}) = 19.6, 130 and 200 GeV. Two observations indicate universal behavior of charged particle production in heavy ion collisions. The first is that forward particle production, over a range of energies, follows a universal limiting curve with a non-trivial centrality dependence. The second arises from comparisons with pp/{bar p}p and e{sup +}e{sup -} data. / in nuclear collisions at high energy scales with {radical}s in a similar way as N{sub ch} in e{sup +}e{sup -} collisions and has a very weak centrality dependence. These features may be related to a reduction in the leading particle effect due to the multiple collisions suffered per participant in heavy ion collisions.

  13. Ion mobility-mass spectrometry of phosphorylase B ions generated with supercharging reagents but in charge-reducing buffer.

    PubMed

    Hogan, Christopher J; Ogorzalek Loo, Rachel R; Loo, Joseph A; de la Mora, Juan Fernandez

    2010-11-07

    We investigate whether "supercharging" reagents able to shift the charge state distributions (CSDs) of electrosprayed protein ions upward also influence gas-phase protein structure. A differential mobility analyzer and a mass spectrometer are combined in series (DMA-MS) to measure the mass and mobility of monomer and multimeric phosphorylase B ions (monomer molecular weight ∼97 kDa) in atmospheric pressure air. Proteins are electrosprayed from charge-reducing triethylammonium formate in water (pH = 6.8) with and without the addition of the supercharging reagent tetramethylene sulfone (sulfolane). Because the DMA measures ion mobility prior to collisional heating or declustering, it probes the structure of supercharged protein ions immediately following solvent (water) evaporation. As in prior studies, the addition of sulfolane is found to drastically increase both the mean and maximum charge state of phosphorylase B ions. Ions from all protein n-mers were found to yield mobilities that, for a given charge state, were ∼6-10% higher in the absence of sulfolane. We find that the mobility decrease which arises with sulfolane is substantially smaller than that typically observed for folded-to-unfolded transitions in protein ions (where a ∼60% decrease in mobility is typical), suggesting that supercharging reagents do not cause structural protein modifications in solution as large as noted recently by Williams and colleagues [E. R. Williams et al., J. Am. Soc. Mass Spectrom., 2010, 21, 1762-1774]. In fact, the measurements described here indicate that the modest mobility decrease observed can be partly attributed to sulfolane trapping within the protein ions during DMA measurements, and probably also in solution. As the most abundant peaks in measured mass-mobility spectra for ions produced with and without sulfolane correspond to non-covalently bound phosphorylase B dimers, we find that in spite of a change in mobility/cross section, sulfolane addition does not

  14. Metastable charge-transfer state of californium(iii) compounds.

    PubMed

    Liu, Guokui; Cary, Samantha K; Albrecht-Schmitt, Thomas E

    2015-06-28

    Among a series of anomalous physical and chemical properties of Cf(iii) compounds revealed by recent investigations, the present work addresses the characteristics of the optical spectra of An(HDPA)3·H2O (An = Am, Cm, and Cf), especially the broadband photoluminescence from Cf(HDPA)3·H2O induced by ligand-to-metal charge transfer (CT). As a result of strong ion-ligand interactions and the relative ease of reducing Cf(iii) to Cf(ii), a CT transition occurs at low energy (<3 eV) via the formation of a metastable Cf(ii) state. It is shown that the systematic trend in CT transitions of the lanthanide series is not paralleled by actinide elements lighter than Cf(iii), and californium represents a turning point in the periodicity of the actinide series. Analyses and modeling of the temperature-dependent luminescence dynamics indicate that the metastable Cf(ii) charge-transfer state undergoes radiative and non-radiative relaxations. Broadening of the CT transition arises from strong vibronic coupling and hole-charge interactions in the valence band. The non-radiative relaxation of the metastable CT state results from a competition between phonon-relaxation and thermal tunneling that populates the excited states of Cf(iii).

  15. Impact of Charge Methodology Upon the Performance of Lithium Ion Cells

    NASA Technical Reports Server (NTRS)

    Smart, M. C.; Ratnakumar, B. V.; Whitcanack, L.; Chin, K.; Surampudi, S.

    2002-01-01

    This viewgraph gives an overview on the impact of charge methodology upon the performance of lithium ion cells. Charge characteristics are given on the following: (1) lithium ion prototype cells, including charge rate characteristics at different temperatures, the effect of charge methodology upon cycle life performance, the effect of charge voltage upon cell performance; (2) three-electrode cells; and (3) lithium-ion eight-cell batteries.

  16. Momentum transfer in relativistic heavy ion charge-exchange reactions

    NASA Technical Reports Server (NTRS)

    Townsend, L. W.; Wilson, J. W.; Khan, F.; Khandelwal, G. S.

    1991-01-01

    Relativistic heavy ion charge-exchange reactions yield fragments (Delta-Z = + 1) whose longitudinal momentum distributions are downshifted by larger values than those associated with the remaining fragments (Delta-Z = 1, -2,...). Kinematics alone cannot account for the observed downshifts; therefore, an additional contribution from collision dynamics must be included. In this work, an optical model description of collision momentum transfer is used to estimate the additional dynamical momentum downshift. Good agreement between theoretical estimates and experimental data is obtained.

  17. Modeling space charge in beams for heavy-ion fusion

    SciTech Connect

    Sharp, W.M.

    1995-05-02

    A new analytic model is presented which accurately estimates the radially averaged axial component of the space-charge field of an axisymmetric heavy-ion beam in a cylindrical beam pipe. The model recovers details of the field near the beam ends that are overlooked by simpler models, and the results compare well to exact solutions of Poisson`s equation. Field values are shown for several simple beam profiles and are compared with values obtained from simpler models.

  18. Production of a highly charged uranium ion beam with RIKEN superconducting electron cyclotron resonance ion source

    SciTech Connect

    Higurashi, Y.; Ohnishi, J.; Nakagawa, T.; Haba, H.; Fujimaki, M.; Komiyama, M.; Kamigaito, O.; Tamura, M.; Aihara, T.; Uchiyama, A.

    2012-02-15

    A highly charged uranium (U) ion beam is produced from the RIKEN superconducting electron cyclotron resonance ion source using 18 and 28 GHz microwaves. The sputtering method is used to produce this U ion beam. The beam intensity is strongly dependent on the rod position and sputtering voltage. We observe that the emittance of U{sup 35+} for 28 GHz microwaves is almost the same as that for 18 GHz microwaves. It seems that the beam intensity of U ions produced using 28 GHz microwaves is higher than that produced using 18 GHz microwaves at the same Radio Frequency (RF) power.

  19. EBIT in the Magnetic Trapping Mode: Mass Spectrometry, Atomic Lifetime Measurements, and Charge Transfer Reactions of Highly Charged Atomic Ions

    SciTech Connect

    Schweikhard, L; Beiersdorfer, P; Trabert, E

    2001-07-10

    Although it may sound like a contradiction in terms, the electron beam ion trap (EBIT) works as an ion trap even when the electron beam is switched off. We present various experiments that exploit the ''magnetic trapping mode'' for investigations of ion confinement, charge exchange processes, atomic lifetime and ion mass measurements.

  20. Laboratory Studies of Thermal Energy Charge Transfer of Multiply Charged Ions in Astrophysical Plasmas

    NASA Technical Reports Server (NTRS)

    Kwong, Victor H. S.

    2003-01-01

    The laser ablation/ion storage facility at the UNLV Physics Department has been dedicated to the study of atomic and molecular processes in low temperature plasmas. Our program focuses on the charge transfer (electron capture) of multiply charged ions and neutrals important in astrophysics. The electron transfer reactions with atoms and molecules is crucial to the ionization condition of neutral rich photoionized plasmas. With the successful deployment of the Far Ultraviolet Spectroscopic Explorer (FUSE) and the Chandra X-ray Observatory by NASA high resolution VUV and X-ray emission spectra fiom various astrophysical objects have been collected. These spectra will be analyzed to determine the source of the emission and the chemical and physical environment of the source. The proper interpretation of these spectra will require complete knowledge of all the atomic processes in these plasmas. In a neutral rich environment, charge transfer can be the dominant process. The rate coefficients need to be known accurately. We have also extended our charge transfer measurements to KeV region with a pulsed ion beam. The inclusion of this facility into our current program provides flexibility in extending the measurement to higher energies (KeV) if needed. This flexibility enables us to address issues of immediate interest to the astrophysical community as new observations are made by high resolution space based observatories.

  1. X-ray And EUV Spectroscopy Of Highly Charged Tungsten Ions

    SciTech Connect

    Biedermann, Christoph; Radtke, Rainer

    2009-09-10

    The Berlin EBIT has been established by the Max-Planck-Institut fuer Plasmaphysik to generate atomic physics data in support of research in the field of controlled nuclear fusion, by measuring the radiation from highly charged ions in the x-ray, extreme ultraviolet and visible spectral ranges and providing valuable diagnostics for high temperature plasmas. In future fusion devices, for example ITER, currently being constructed at Cadarache, France, the plasma facing components will be armored with high-Z materials, most likely tungsten, due to the favorable properties of this element. At the same time the tremendous radiation cooling of these high-Z materials represents a threat to fusion and obliges one to monitor carefully the radiation. With EBIT a selected ensemble of ions in specific charge states can be produced, stored and excited for spectroscopic investigations. Employing this technique, we have for example resolved the wide structure observed around 5 nm at the ASDEX Upgrade tokamak as originating from E1-transitions into the open 4d shell of tungsten ions in charge states 25+ to 37+ producing a band-like emission pattern. Further, these ions emit well-separated M1 lines in the EUV range around 65 nm suitable for plasma diagnostics. Kr-like to Cr-like tungsten ions (38+ to 50+) show strong soft-x-ray lines in the range 0.5 to 2 and 5 to 15 nm. Lines of even higher charged tungsten ions, up to Ne-like W{sup 64+}, abundant in the core plasma of present and future fusion test devices, have been investigated with high resolution Bragg-crystal spectroscopy at 0.13 nm. Recently, x-ray spectroscopic measurements of the dielectronic recombination LMn resonances of W{sup 60+} to W{sup 67+} ions have been preformed and compare well with atomic structure calculations.

  2. Electron emission and defect formation in the interaction of slow,highly charged ions with diamond surfaces

    SciTech Connect

    Sideras-Haddad, E.; Shrivastava, S.; Rebuli, D.B.; Persaud, A.; Schneider, D.H.; Schenkel, T.

    2006-05-31

    We report on electron emission and defect formation in theinteraction between slow (v~;0.3 vBohr) highly charged ions (SHCI) withinsulating (type IIa) and semiconducting (type IIb) diamonds. Electronemission induced by 31Pq+ (q=5 to 13), and 136Xeq+ (q=34 to 44) withkinetic energies of 9 kVxq increase linearly with the ion charge states,reaching over 100 electrons per ion for high xenon charge states withoutsurface passivation of the diamond with hydrogen. Yields from bothdiamond types are up to a factor of two higher then from reference metalsurfaces. Crater like defects with diameters of 25 to 40 nm are formed bythe impact of single Xe44+ ions. High secondary electron yields andsingle ion induced defects enable the formation of single dopant arrayson diamond surfaces.

  3. Dynamics of Ion Beam Charge Neutralization by Ferroelectric Plasma Sources

    NASA Astrophysics Data System (ADS)

    Stepanov, Anton D.; Gilson, Erik P.; Grisham, Larry R.; Kaganovich, Igor D.; Davidson, Ronald C.; Ji, Qing; Persaud, Arun; Seidl, Peter A.; Schenkel, Thomas

    2016-10-01

    Ferroelectric Plasma Sources (FEPSs) can generate plasma that provides effective space-charge neutralization of intense high-perveance ion beams. Here we present experimental results on charge neutralization of a high-perveance 38 keV Ar+ beam by a FEPS plasma. By comparing the measured beam radius with the envelope model for space-charge expansion, it is shown that a charge neutralization fraction of 98% is attainable. The transverse electrostatic potential of the ion beam is reduced from 15 V before neutralization to 0.3 V, implying that the energy of the neutralizing electrons is below 0.3 eV. Near-complete charge neutralization is established 5 μs after the driving pulse is applied to the FEPS, and can last for 35 μs. It is argued that the duration of neutralization is much longer than a reasonable lifetime of the plasma produced in the sub- μs surface discharge. Measurements of current flow in the driving circuit of the FEPS suggest that plasma can be generated for tens of μs after the high voltage pulse is applied. This is confirmed by fast photography of the plasma in the 1-meter long FEPS on NDCX-II, where effective charge neutralization of the beam was achieved with the optimized FEPS timing. This work was supported by the Office of Science of the US Department of Energy under contracts DE-AC0209CH11466 (PPPL) and DE-AC0205CH11231 (LBNL).

  4. Size-to-charge dispersion of collision-induced dissociation product ions for enhancement of structural information and product ion identification.

    PubMed

    Zinnel, Nathanael F; Russell, David H

    2014-05-20

    Ion mobility is used to disperse product ions formed by collision-induced dissociation (CID) on the basis of charge state and size-to-charge ratio. We previously described an approach for combining CID with ion mobility mass spectrometry (IM-MS) for dispersing fragment ions along charge state specific trend lines (Zinnel, N. F.; Pai, P. J.; Russell, D. H. Anal. Chem. 2012, 84, 3390; Sowell, R. A.; Koeniger, S. L.; Valentine, S. J.; Moon, M. H.; Clemmer, D. E. J. Am. Soc. Mass Spectrom. 2004, 15, 1341; McLean, J. A.; Ruotolo, B. T.; Gillig, K. J.; Russell, D. H. Int. J. Mass Spectrom. 2005, 240, 301), and this approach was used to assign metal ion binding sites for human metallothionein protein MT-2a (Chen, S. H.; Russell, W. K.; Russell, D. H. Anal. Chem. 2013, 85, 3229). Here, we use this approach to distinguish b-type N-terminal fragment ions from both internal fragment ions and y-type C-terminal fragment ions. We also show that in some cases specific secondary structural elements, viz., extended coils or helices, can be obtained for the y-type fragment ions series. The advantage of this approach is that product ion identity can be correlated to gas-phase ion structure, which provides rapid identification of the onset and termination of extended coil structure in peptides.

  5. Fragmentation of organic ions bearing fixed multiple charges observed in MALDI MS.

    PubMed

    Lou, Xianwen; Li, Bao; de Waal, Bas F M; Schill, Jurgen; Baker, Matthew B; Bovee, Ralf A A; van Dongen, Joost L J; Milroy, Lech-Gustav; Meijer, E W

    2017-09-29

    Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI TOF MS) was used to analyze a series of synthetic organic ions bearing fixed multiple charges. Despite the multiple intrinsic charges, only singly charged ions were recorded in each case. In addition to the pseudo-molecular ions formed by counter-ion adduction, deprotonation and electron-capture, a number of fragment ions were also observed. Charge splitting by fragmentation was found to be a viable route for charge reduction leading to the formation of the observed singly charged fragment ions. Unlike multivalent metal ions, organic ions can rearrange and/or fragment during charge reduction. This fragmentation process will evidently complicate the interpretation of the MALDI MS spectrum. Because MALDI MS is usually considered as a soft ionization technique, the fragment ion peaks can easily be erroneously interpreted as impurities. Therefore, the awareness and understanding of the underlying MALDI-induced fragmentation pathways is essential for a proper interpretation of the corresponding mass spectra. Due to the fragment ions generated during charge reduction, special care should be taken in the MALDI MS analysis of multiply charged ions. In this work, the possible mechanisms by which the organic ions bearing fixed multiple charges fragment are investigated. With an improved understanding of the fragmentation mechanisms, MALDI TOF MS should still be a useful technique for the characterization of organic ions with fixed multiple charges. This article is protected by copyright. All rights reserved.

  6. Charged particle measurements on a 30-CM diameter mercury ion engine thrust beam

    NASA Technical Reports Server (NTRS)

    Sellen, J. M., Jr.; Komatsu, G. K.; Hoffmaster, D. K.; Kemp, R. F.

    1974-01-01

    Measurements of both thrust ions and charge exchange ions were made in the beam of a 30 centimeter diameter electron bombardment mercury ion thruster. A qualitative model is presented which describes magnitudes of charge exchange ion formation and motions of these ions in the weak electric field structure of the neutralized thrust beam plasma. Areas of agreement and discrepancy between observed and modeled charge exchange properties are discussed.

  7. Structural Heterogeneity of Doubly-Charged Peptide b-Ions

    PubMed Central

    Li, Xiaojuan; Huang, Yiqun; O’Connor, Peter B.; Lin, Cheng

    2011-01-01

    Performing collisionally activated dissociation (CAD) and electron capture dissociation (ECD) in tandem has shown great promise in providing comprehensive sequence information that was otherwise unobtainable by using either fragmentation method alone or in duet. However, the general applicability of this MS3 approach in peptide sequencing may be undermined by the formation of non-direct sequence ions, as sometimes observed under CAD, particularly when multiple stages of CAD are involved. In this study, varied-sized doubly-charged b-ions from three tachykinin peptides were investigated by ECD. Sequence scrambling was observed in ECD of all b-ions from neurokinin A (HKTDSFVGLM-NH2), suggesting the presence of N- and C-termini linked macro-cyclic conformers. On the contrary, none of the b-ions from eledoisin (pEPSKDAFIGLM-NH2) produced non-direct sequence ions under ECD, as it does not contain a free N-terminal amino group. ECD of several b-ions from Substance P (RPKPQQFFGLM-NH2) showed series of cm-Lys fragment ions which suggested that the macro-cyclic structure may also be formed by connecting the C-terminal carbonyl group and the ε-amino group of the lysine side chain. Theoretical investigation of selected Substance P b-ions revealed several low energy conformers, including both linear oxazolones and macro-ring structures, in corroboration with the experimental observation. This study showed that a b-ion may exist as a mixture of several forms, with their propensities influenced by its N-terminus, length, and certain side-chain groups. Further, the presence of several macro-cyclic structures may result in erroneous sequence assignment when the combined CAD and ECD methods are used in peptide sequencing. PMID:21472584

  8. Intense highly charged ion beam production and operation with a superconducting electron cyclotron resonance ion source

    NASA Astrophysics Data System (ADS)

    Zhao, H. W.; Sun, L. T.; Guo, J. W.; Lu, W.; Xie, D. Z.; Hitz, D.; Zhang, X. Z.; Yang, Y.

    2017-09-01

    The superconducting electron cyclotron resonance ion source with advanced design in Lanzhou (SECRAL) is a superconducting-magnet-based electron cyclotron resonance ion source (ECRIS) for the production of intense highly charged heavy ion beams. It is one of the best performing ECRISs worldwide and the first superconducting ECRIS built with an innovative magnet to generate a high strength minimum-B field for operation with heating microwaves up to 24-28 GHz. Since its commissioning in 2005, SECRAL has so far produced a good number of continuous wave intensity records of highly charged ion beams, in which recently the beam intensities of 40Ar+ and 129Xe26+ have, for the first time, exceeded 1 emA produced by an ion source. Routine operations commenced in 2007 with the Heavy Ion accelerator Research Facility in Lanzhou (HIRFL), China. Up to June 2017, SECRAL has been providing more than 28,000 hours of highly charged heavy ion beams to the accelerator demonstrating its great capability and reliability. The great achievement of SECRAL is accumulation of numerous technical advancements, such as an innovative magnetic system and an efficient double-frequency (24 +18 GHz ) heating with improved plasma stability. This article reviews the development of SECRAL and production of intense highly charged ion beams by SECRAL focusing on its unique magnet design, source commissioning, performance studies and enhancements, beam quality and long-term operation. SECRAL development and its performance studies representatively reflect the achievements and status of the present ECR ion source, as well as the ECRIS impacts on HIRFL.

  9. X-ray radiography with highly charged ions

    DOEpatents

    Marrs, Roscoe E.

    2000-01-01

    An extremely small (1-250 micron FWHM) beam of slow highly charged ions deexciting on an x-ray production target generates x-ray monochromatic radiation that is passed through a specimen and detected for imaging. The resolution of the x-ray radiograms is improved and such detection is achieved with relatively low dosages of radiation passing through the specimen. An apparatus containing an electron beam ion trap (and modifications thereof) equipped with a focusing column serves as a source of ions that generate radiation projected onto an image detector. Electronic and other detectors are able to detect an increased amount of radiation per pixel than achieved by previous methods and apparati.

  10. Positively and Negatively Charged Cesium and (C60) m Cs n Cluster Ions.

    PubMed

    Renzler, Michael; Kranabetter, Lorenz; Goulart, Marcelo; Scheier, Paul; Echt, Olof

    2017-05-25

    We report on the formation and ionization of cesium and C60Cs clusters in superfluid helium nanodroplets. Size distributions of positively and negatively charged (C60) m Cs n(±) ions have been measured for m ≤ 7, n ≤ 12. Reproducible intensity anomalies are observed in high-resolution mass spectra. For both charge states, (C60) m Cs3(±) and (C60) m Cs5(±) are particularly abundant, with little dependence on the value of m. Distributions of bare cesium cluster ions also indicate enhanced stability of Cs3(±) and Cs5(±), in agreement with theoretical predictions. These findings contrast with earlier reports on highly Cs-doped cationic fullerene aggregates which showed enhanced stability of C60Cs6 building blocks attributed to charge transfer. The dependence of the (C60) m Cs3(-) anion yield on electron energy shows a resonance that, surprisingly, oscillates in strength as m increases from 1 to 6.

  11. Correlated charge-changing ion-atom collisions. Progress report, March 16, 1991--March 15, 1992

    SciTech Connect

    Tanis, J.A.

    1992-04-01

    This report summarizes the progress and accomplishments in accelerator atomic physics research supported by DOE grant DE-FG02-87ER13778 from March 16, 1991 through March 15, 1992. This work involves the experimental investigation of fundamental atomic processes in collisions of charged projectiles with neutral targets or electrons, with particular emphasis on two-electron interactions and electron correlation effects. Processes involving combinations of excitation, ionization, and charge transfer are investigated utilizing coincidence techniques in which projectiles charge-changing events are associated with x-ray emission, target recoil ions, or electron emission. New results have been obtained for studies involving (1) resonant recombination of atomic ions, (2) double ionization of helium, and (3) continuum electron emission. Experiments were conducted using accelerators at the Lawrence Berkeley Laboratory, Argonne National Laboratory, Michigan State University, Western Michigan University, and the Institute of Nuclear Research, Debrecen, Hungary. Brief summaries of work completed and work in progress are given in this report.

  12. Rocket Propulsion Through Multiply-Charged Ions From a Mirror Plasma

    SciTech Connect

    Leung, L.; Petty, C. C.

    2007-09-28

    This paper evaluates a new type of ambipolar plasma thruster that uses multiply-charged ions as propellant. Beginning with an electron cyclotron heated (ECH) mirror plasma with energetic electrons, the ion charge state distribution and confining electrostatic potentials are self-consistently modeled for different fill gases using the particle, charge, and energy conservation equations and Pastukhov-flow confinement. The specific impulse is found to be high ({approx}6000 s) and easily varied. Although the thrust efficiency is low, 24% for double-ended operation and 45% for single-ended operation, this ambipolar thruster is capable of producing high thrust in a compact source because ECH mirror plasmas can operate at high density.

  13. Laser acceleration of electrons to giga-electron-volt energies using highly charged ions.

    PubMed

    Hu, S X; Starace, Anthony F

    2006-06-01

    The recent proposal to use highly charged ions as sources of electrons for laser acceleration [S. X. Hu and A. F. Starace, Phys. Rev. Lett. 88, 245003 (2002)] is investigated here in detail by means of three-dimensional, relativistic Monte Carlo simulations for a variety of system parameters, such as laser pulse duration, ionic charge state, and laser focusing spot size. Realistic laser focusing effects--e.g., the existence of longitudinal laser field components-are taken into account. Results of spatial averaging over the laser focus are also presented. These numerical simulations show that the proposed scheme for laser acceleration of electrons from highly charged ions is feasible with current or near-future experimental conditions and that electrons with GeV energies can be obtained in such experiments.

  14. Spectroscopy of Highly Charged Tin Ions for AN Extreme Ultraviolet Light Source for Lithography

    NASA Astrophysics Data System (ADS)

    Torretti, Francesco; Windberger, Alexander; Ubachs, Wim; Hoekstra, Ronnie; Versolato, Oscar; Ryabtsev, Alexander; Borschevsky, Anastasia; Berengut, Julian; Crespo Lopez-Urrutia, Jose

    2017-06-01

    Laser-produced tin plasmas are the prime candidates for the generation of extreme ultraviolet (EUV) light around 13.5 nm in nanolithographic applications. This light is generated primarily by atomic transitions in highly charged tin ions: Sn^{8+}-Sn^{14+}. Due to the electronic configurations of these charge states, thousands of atomic lines emit around 13.5 nm, clustered in a so-called unresolved transition array. As a result, accurate line identification becomes difficult in this regime. Nevertheless, this issue can be circumvented if one turns to the optical: with far fewer atomic states, only tens of transitions take place and the spectra can be resolved with far more ease. We have investigated optical emission lines in an electron-beam-ion-trap (EBIT), where we managed to charge-state resolve the spectra. Based on this technique and on a number of different ab initio techniques for calculating the level structure, the optical spectra could be assigned [1,2]. As a conclusion the assignments of EUV transitions in the literature require corrections. The EUV and optical spectra are measured simultaneously in the controlled conditions of the EBIT as well as in a droplet-based laser-produced plasma source providing information on the contribution of Sn^{q+} charge states to the EUV emission. [1] A. Windberger, F. Torretti, A. Borschevsky, A. Ryabtsev, S. Dobrodey, H. Bekker, E. Eliav, U. Kaldor, W. Ubachs, R. Hoekstra, J.R. Crespo Lopez-Urrutia, O.O. Versolato, Analysis of the fine structure of Sn^{11+} - Sn^{14+} ions by optical spectroscopy in an electron beam ion trap, Phys. Rev. A 94, 012506 (2016). [2] F. Torretti, A. Windberger, A. Ryabtsev, S. Dobrodey, H. Bekker, W. Ubachs, R. Hoekstra, E.V. Kahl, J.C. Berengut, J.R. Crespo Lopez-Urrutia, O.O. Versolato, Optical spectroscopy of complex open 4d-shell ions Sn^{7+} - Sn^{10+}, arXiv:1612.00747

  15. Transport of intense beams of highly charged ions

    NASA Astrophysics Data System (ADS)

    Winkler, M.; Gammino, S.; Ciavola, G.; Celona, L.; Spadtke, P.; Tinschert, K.

    2005-10-01

    The new generation of ion sources delivers beams with intensities of several mA. This requires a careful design of the analysing system and the low-energy beam transport (LEBT) from the source to the subsequent systems. At INFN-LNS, high intensity proton sources (TRIPS [L. Celona, G. Ciavola, S. Gammino et al ., Rev. Sci. Instrum. 75(5) 1423 (2004)], PM-TRIPS [G. Ciavola, L. Celona, S. Gammino et al ., Rev. Sci. Instrum. 75(5) 1453 (2004)]) as well as ECR ion sources for the production of highly charged high-intensity heavy ion beams are developed (SERSE [S. Gammino, G. Ciavola, L. Celona et al ., Rev. Sci. Instrum. 72(11) 4090 (2001), and references therein], GyroSERSE [S. Gammino et al ., Rev. Sci. Instrum. 75(5) 1637 (2004)], MS-ECRIS [G. Ciavola et al ., (2005), 11th Int. Conf. on Ion Sources, Caen, (in press)]). In this paper, we present ion-optical design studies of various LEBT systems for ion-sources devoted to the production of intense beams. Calculations were performed using the computer codes GIOS [H. Wollnik, J. Brezina and M. Berz, NIM A 258 (1987)], GICO [M. Berz, H.C. Hoffmann, and H. Wollnik, NIM A 258 (1987)], and TRANSPORT [K.L. Brown, F. Rothacker and D.C. Carey, SLAC-R-95-462, Fermilab-Pub-95/069, UC-414 (1995)]. Simulations take into account the expected phase space growth of the beam emittance due to space-charge effects and image aberrations introduced by the magnetic elements.

  16. Photoionization of Doubly-Charged Ba2+ Ions using an ECR