WorldWideScience

Sample records for charge exchange injection

  1. Laser-Assisted H- Charge Exchange Injection in Magnetic Fields

    Energy Technology Data Exchange (ETDEWEB)

    Gorlov, Timofey V [ORNL; Danilov, Viatcheslav V [ORNL; Shishlo, Andrei P [ORNL

    2010-01-01

    The use of stripping foils for charge exchange injection can cause a number of operational problems in high intensity hadron accelerators. A recently proposed three-step method of laser-assisted injection is capable of overcoming these problems. This paper presents advances in the physical model of laser-assisted charge exchange injection of H- beams and covers a wide field of atomic physics. The model allows the calculation of the evolution of an H0 beam taking into account spontaneous emission, field ionization and external electromagnetic fields. Some new data on the hydrogen atom related to the problem are calculated. The numerical calculations in the model use realistic descriptions of laser field and injection beam. Generally, the model can be used for design and optimization of a laser-assisted injection cell within an accelerator lattice. Example calculations of laser-assisted injection for an intermediate experiment at SNS in Oak Ridge and for the PS2 accelerator at CERN are presented. Two different schemes, distinctively characterized by various magnetic fields at the excitation point, are discussed. It was shown that the emittance growth of an injected beam can be drastically decreased by moving excitation point into a strong magnetic field.

  2. Laser-assisted H- charge exchange injection in magnetic fields

    Science.gov (United States)

    Gorlov, T.; Danilov, V.; Shishlo, A.

    2010-05-01

    The use of stripping foils for charge exchange injection can cause a number of operational problems in high intensity hadron accelerators. A recently proposed three-step method of laser-assisted injection is capable of overcoming these problems. This paper presents advances in the physical model of laser-assisted charge exchange injection of H- beams and covers a wide field of atomic physics. The model allows the calculation of the evolution of an H0 beam taking into account spontaneous emission, field ionization, and external electromagnetic fields. Some new data on the hydrogen atom related to the problem are calculated. The numerical calculations in the model use realistic descriptions of laser field and injection beam. Generally, the model can be used for design and optimization of a laser-assisted injection cell within an accelerator lattice. Example calculations of laser-assisted injection for an intermediate experiment at SNS in Oak Ridge and for the PS2 accelerator at CERN are presented. Two different schemes, distinctively characterized by various magnetic fields at the excitation point, are discussed. It was shown that the emittance growth of an injected beam can be drastically decreased by moving the excitation point into a strong magnetic field.

  3. The first test experiment of H- charge-exchange injection in the KEK booster

    International Nuclear Information System (INIS)

    The H- charge-exchange injection method was applied to the 500 MeV booster of the 12 GeV proton synchrotron at KEK, as an alternative to the multi-turn injection method using direct injection of protons. The first test experiment of such injection was carried out during three weeks beginning in late September 1983. Experimental results showed that, in spite of the low injection energy used for our booster, such an injection method is promising for increasing the beam intensity of the booster. And also, some further improvements are proposed. (author)

  4. Charge exchange momentum transfer due to ion beam injection in partially ionized plasmas

    International Nuclear Information System (INIS)

    Time responses of a helium plasma to helium gas puffing without and with helium beam injection in a linear plasma device are experimentally investigated. Increase in the neutral density due to gas puffing is suppressed by ion beam injection. The experimental results show that a momentum transport from the ion beam to the puffed neutral particles occurs due to the charge exchange interaction, suggesting that charge exchange momentum transport is one of the processes responsible for the spatial redistribution of neutral atoms in partially ionized plasmas. (author)

  5. Kinetic treatment of the heavy ion charge exchange injection in synchrotrons

    CERN Document Server

    Dinev, D

    2002-01-01

    This paper describes the results of a kinetic treatment of the charge exchange injection of heavy ions into synchrotrons. Analytical expressions for the evolution of particle density in the transverse phase space and for the emittance growth due to elastic scattering and energy losses in the stripper have been derived. Numerical examples for the superconducting heavy ion synchrotron Nuclotron in JINR-Dubna are given as well.

  6. Performance of the CERN PSB at 160 MeV with $H^{-}$ charge exchange injection

    CERN Document Server

    AUTHOR|(CDS)2084247; Santoni, Claudio

    As part of the LHC Injectors Upgrade Project, the CERN PS Booster (PSB) will be upgraded with a H- charge exchange injection system and its injection energy will be raised from 50 MeV to 160 MeV to obtain the beam brightness required for the LHC High-Luminosity Upgrade. Space charge effects like beam losses and transverse emittance blow-up at injection are expected to be the main limitations towards the achievement of the required high brightness. Studies of beam dynamics in presence of space charge in order to evaluate the performances of the PSB after the Upgrade have been performed. The first part of the work consists of measurements in the present machine, to study the effects of space charge and its interplay with resonances and to have a good set of data for code benchmarking. The code chosen for the beam tracking in presence of space charge is PTC-Orbit (and PyOrbit). Necessary numerical convergence studies are presented together with a benchmark with the PSB measurements. Once assessed the code and it...

  7. Longitudinal painting schemes for H- charge exchange injection into the PS2

    CERN Document Server

    Benedikt, M; Hancock, S; Knünz, V; Vonderhaid, I

    2010-01-01

    Minimization of direct space charge tune shift at injection into the PS2 is important for the reduction of beam losses. A determining parameter for the tune shift is the bunching factor, defined as mean current over peak current for one RF period. Various longitudinal painting schemes for PS2 injection, all based on synchrotron motion, have been studied with respect to the resulting bunching factors.

  8. ACTIVE LONGITUDINAL PAINTING FOR THE H-CHARGE EXCHANGE INJECTION OF THE LINAC4 BEAM INTO THE PS BOOSTER

    CERN Document Server

    CARLI, C; CERN. Geneva. AB Department

    2008-01-01

    Linac4 will provide 160 MeV H- to the PS Booster synchrotron. The H-beam will be injected by charge exchange injection allowing injecting several times into the same volumes of phase space. Thus, a large number of turns can be injected with high efficiencies and â€ワpainting” in order to shape the initial particle distribution for optimum performance becomes possible. In particular, a chopper makes longitudinal painting possible in addition to painting in transverse phase spaces. The slow synchrotron motion in the PS Booster implies an active longitudinal painting scheme, where the Linac4 output energy is modulated. Several active longitudinal painting schemes are presented. One scheme, based on a triangular Linac energy modulation, is proposed for the PS Booster H- injection with Linac4.

  9. Beam emittance growth in a proton storage ring employing charge exchange injection

    International Nuclear Information System (INIS)

    Recently, it has been shown that very large currents can be accumulated in medium energy proton storage rings by multiturn injection of an H- beam through a charge stripping medium. Since the particles are injected continuously into the same phase space, it is possible to increase the circulating beam brightness with respect to that of the incoming beam by a large factor. The stored protons pass repeatedly through the stripper, however, so that this phase space is gradually enlarged by scattering. The dependence of the circulating beam phase space (emittance) growth rate on the nature of the scattering process and on where it occurs in the storage ring matrix is considered. Since the motivation for this work arose in connection with the design of the proposed high-current storage ring at LAMPF, the results are focused on the specific parameters of that device. (U.S.)

  10. Charge exchange system

    Science.gov (United States)

    Anderson, Oscar A.

    1978-01-01

    An improved charge exchange system for substantially reducing pumping requirements of excess gas in a controlled thermonuclear reactor high energy neutral beam injector. The charge exchange system utilizes a jet-type blanket which acts simultaneously as the charge exchange medium and as a shield for reflecting excess gas.

  11. Charge exchange produced K-shell x-ray emission from Ar16+ in a tokamak plasma with neutral beam injection

    Energy Technology Data Exchange (ETDEWEB)

    Beiersdorfer, P; Bitter, M; Marion, M; Olson, R E

    2004-12-27

    High-resolution spectroscopy of hot tokamak plasma seeded with argon ions and interacting with an energetic, short-pulse neutral hydrogen beam was used to obtain the first high-resolution K-shell x-ray spectrum formed solely by charge exchange. The observed K-shell emission of Ar{sup 16+} is dominated by the intercombination and forbidden lines, providing clear signatures of charge exchange. Results from an ab initio atomic cascade model provide excellent agreement, validating a semiclassical approach for calculating charge exchange cross sections.

  12. Charge-exchange straggling in equilibrium

    Energy Technology Data Exchange (ETDEWEB)

    Sigmund, P. [Department of Physics and Chemistry, University of Southern Denmark, DK-5230 Odense M (Denmark); Osmani, O. [Department of Physics, University of Duisburg-Essen, D-47048 Duisburg (Germany); Department of Physics, University of Kaiserslautern and Research Center OPTIMAS, D-67653 Kaiserslautern (Germany); Schinner, A. [Institut fuer Experimentalphysik, Johannes, Kepler Universitaet, A-4040 Linz (Austria)

    2011-05-01

    A general expression has been derived that allows computation of charge-exchange straggling of swift heavy ions when many charge states are involved. Charge exchange is found to hinge on the variation of the stopping cross section with the ion charge and on the transient behavior of the charge population as a function of traveled pathlength. These effects appear factorized in the final formula. The focus of this paper is on straggling in charge equilibrium. The case of MeV/u sulfur ions in carbon has been used as an illustration. Charge-exchange straggling is found to be dominating straggling over a considerable range of beam energies.

  13. Production of antihydrogen via double charge exchange

    International Nuclear Information System (INIS)

    Spectroscopy of the 1S-2S transition of antihydrogen confined in a neutral atom trap and comparison with the equivalent spectral line in hydrogen will provide an accurate test of CPT symmetry and the first one in a mixed baryon-lepton system. Also, with neutral antihydrogen atoms, the gravitational interaction between matter and antimatter can be tested unperturbed by the much stronger Coulomb forces. Antihydrogen is regularly produced at CERN's Antiproton Decelerator by three-body-recombination (TBR) of one antiproton and two positrons. The method requires injecting antiprotons into a cloud of positrons, which raises the average temperature of the antihydrogen atoms produced way above the typical 0.5 K trap depths of neutral atom traps. Therefore only very few antihydrogen atoms can be confined at a time. Precision measurements, like laser spectroscopy, will greatly benefit from larger numbers of simultaneously trapped antihydrogen atoms. Therefore, the ATRAP collaboration developed a different production method that has the potential to create much larger numbers of cold, trappable antihydrogen atoms. Positrons and antiprotons are stored and cooled in a Penning trap in close proximity. Laser excited cesium atoms collide with the positrons, forming Rydberg positronium, a bound state of an electron and a positron. The positronium atoms are no longer confined by the electric potentials of the Penning trap and some drift into the neighboring cloud of antiprotons where, in a second charge exchange collision, they form antihydrogen. The antiprotons remain at rest during the entire process, so much larger numbers of trappable antihydrogen atoms can be produced. Laser excitation is necessary to increase the efficiency of the process since the cross sections for charge-exchange collisions scale with the fourth power of the principal quantum number n. This method, named double charge-exchange, was demonstrated by ATRAP in 2004. Since then, ATRAP constructed a new combined

  14. Charge exchange spectroscopy as a fast ion diagnostic on TEXTOR

    NARCIS (Netherlands)

    Delabie, E.; Jaspers, R. J. E.; von Hellermann, M. G.; Nielsen, S.K.; Marchuk, O.

    2008-01-01

    An upgraded charge exchange spectroscopy diagnostic has been taken into operation at the TEXTOR tokamak. The angles of the viewing lines with the toroidal magnetic field are close to the pitch angles at birth of fast ions injected by one of the neutral beam injectors. Using another neutral beam for

  15. Charge exchange cooling in the tandem mirror plasma confinement apparatus

    International Nuclear Information System (INIS)

    A method and apparatus are described for cooling a plasma confined in the center mirror cell of the tandem mirror apparatus by injecting cold neutral species of the plasma into at least one mirroring region of the center mirror cell. The cooling is due to the loss of warm charged species through charge exchange with the cold neutral species with resulting diffusion of the warm neutral species out of the plasma

  16. Localization and delocalization of charges injected in DNA

    OpenAIRE

    Heim, Thomas; Melin, Thierry; Deresmes, Dominique; Vuillaume, Dominique

    2004-01-01

    To be published in Appl. Phys. Lett. The electrical properties of DNA molecules are investigated by charge injection and electric force microscopy experiments. Prior to injection, DNA molecules exhibit a weak positively charged state. We probe the electrical behaviour of DNA by measuring the localized or delocalized character of the DNA charge states upon injection of excess charges. We show that injected charges do not delocalize for overstretched DNA prepared by a receding meniscus techn...

  17. Around the laboratories: Dubna: Physics results and progress on bubble chamber techniques; Stanford (SLAC): Operation of a very rapid cycling bubble chamber; Daresbury: Photographs of visitors to the Laboratory; Argonne: Charge exchange injection tests into the ZGS in preparation for a proposed Booster

    CERN Multimedia

    1969-01-01

    Around the laboratories: Dubna: Physics results and progress on bubble chamber techniques; Stanford (SLAC): Operation of a very rapid cycling bubble chamber; Daresbury: Photographs of visitors to the Laboratory; Argonne: Charge exchange injection tests into the ZGS in preparation for a proposed Booster

  18. Pion double charge exchange and nuclear structure

    International Nuclear Information System (INIS)

    Pion double charge exchange to both the double-analog state and the ground state is studied for medium weight nuclei. The relative cross section of these two transitions and the importance of nuclear structure as a function of pion kinetic energy is examined. 16 figs., 5 tabs

  19. Charge exchange spectroscopy as a fast ion diagnostic on TEXTOR

    DEFF Research Database (Denmark)

    Delabie, E.; Jaspers, R.J.E.; von Hellermann, M.G.;

    2008-01-01

    active spectroscopy, injected counter the direction in which fast ions injected by the first beam are circulating, we can simultaneously measure a fast ion tail on the blue wing of the D-alpha spectrum while the beam emission spectrum is Doppler shifted to the red wing. An analysis combining the two......An upgraded charge exchange spectroscopy diagnostic has been taken into operation at the TEXTOR tokamak. The angles of the viewing lines with the toroidal magnetic field are close to the pitch angles at birth of fast ions injected by one of the neutral beam injectors. Using another neutral beam for...... parts of the spectrum offers possibilities to improve the accuracy of the absolute (fast) ion density profiles. Fast beam modulation or passive viewing lines cannot be used for background subtraction on this diagnostic setup and therefore the background has to be modeled and fitted to the data together...

  20. Charge exchange in solar wind - coometary interactions

    International Nuclear Information System (INIS)

    The authors examine the effect of charge exchange between fast solar wind ions and slow cometary neutrals at the contact discontinuity separating the ionosphere of a comet from the solar wind flow. The continuity equations were solved analytically for a water-dominated cometary ionosphere, including both ionization and recombination processes. It was found that this new solution differs significantly from the one obtained by neglecting recombination. (author)

  1. Dissociative charge exchange of H2+

    International Nuclear Information System (INIS)

    This thesis is devoted to molecular dissociation, in particular the dissociation of the hydrogen molecule H2 arising from electron capture of its ion H2+ in a collision. Thereby the important practical question how a chemical bond can be broken is implicitly addressed. This thesis opens (chapter I) with an overview of the available experimental approaches in molecular physics. Further the simple Demkov model for NRCE is described. In chapter II a novel experimental technique for measurements on dissociative processes is introduced which combines a high efficiency with a high energy resolution. A detailed description of the techniques applied in the detector, which has a high spatial and timing resolution with 30 μm and 350 psec FWHM respectively for the detection of one particle, is given in chapter III. A semi-classical theory for NRCE in the medium energy range between a diatomic molecular ion and an atom is developed in chapter IV. The experiments on dissociative charge exchange of H2+ with Ar, Mg, Na and Cs targets at keV energies are described in Chapter V. The predissociation of the c3PIsub(u)-state of H2 populated after charge exchange of H2 with several targets at keV energies; is the subject of chapter VI. In chapter VII, orientational oscillations in the cross section for charge exchange of H2+ with alkali targets are discussed. The last chapter deals with predissociation of highly excited states in H2. (Auth.)

  2. Charge Injection, Charge Trapping and Charge Transfer in Quantum-Dot Solids

    OpenAIRE

    Boehme, S.C.

    2015-01-01

    This study reports on fundamental processes in Quantum-Dot Solids, after light absorption. Transient Absorption and Time-resolved Photoluminescence spectrocopy reveal the dynamics of charge transfer and charge trapping processes. Typically, both occur on a picosecond time scale and compete with each other. We find that the efficiency of these processes depends on the Fermi level in the Quantum-Dot Solid. The latter can be controlled electrochemically, via charge injection into the Quantum-Dot...

  3. Anatomy of charge-exchange straggling

    International Nuclear Information System (INIS)

    We have studied charge-exchange straggling theoretically for swift krypton and silicon ions and five target gases in the MeV/u energy regime. We find a pronounced two-peak structure for all ion-target combinations. The peak at the highest energy appears around the velocity where the bare ion and the one-electron ion are equally abundant in the equilibrium charge distribution. Correspondingly, the low-energy peak appears near the cross-over between the charge fractions of the two- and the three-electron ion. The possibility of further peaks at lower energies is discussed. Our findings are compared with recent experimental results on straggling of krypton beams

  4. Anatomy of charge-exchange straggling

    Energy Technology Data Exchange (ETDEWEB)

    Sigmund, P., E-mail: sigmund@sdu.dk [Department of Physics, Chemistry and Pharmacy, University of Southern Denmark, DK-5230 Odense M (Denmark); Osmani, O. [Department of Physics, University of Duisburg-Essen, D-47048 Duisburg (Germany); Schinner, A. [Institut für Experimentalphysik, Johannes Kepler Universität, A-4040 Linz (Austria)

    2014-11-01

    We have studied charge-exchange straggling theoretically for swift krypton and silicon ions and five target gases in the MeV/u energy regime. We find a pronounced two-peak structure for all ion-target combinations. The peak at the highest energy appears around the velocity where the bare ion and the one-electron ion are equally abundant in the equilibrium charge distribution. Correspondingly, the low-energy peak appears near the cross-over between the charge fractions of the two- and the three-electron ion. The possibility of further peaks at lower energies is discussed. Our findings are compared with recent experimental results on straggling of krypton beams.

  5. Charge exchange recombination x-ray laser

    International Nuclear Information System (INIS)

    A recombining plasma x-ray laser using charge exchange recombination (CXR) is proposed. Fully stripped carbon ions collide with neutral He atoms and become excited hydrogenlike carbon ions, in which the excited levels with n=3 or 4 are mainly populated. We calculate the gain coefficients of the Balmer α and the Lyman β line of the hydrogenlike carbon ions by the use of a collisional-radiative model in which the CXR process is included. The calculated result shows that substantial gain can be generated for the Lyman β and Balmer α lines and that the gain of the Balmer α line can be strongly enhanced by the effect of CXR. We also report a preliminary experiment of this scheme. (author)

  6. Systematics of pion double charge exchange

    International Nuclear Information System (INIS)

    Differential cross sections have been measured for pion-induced double-charge-exchange (DCX) reactions leading to double-isobaric-analog states (DIAS) and low-lying nonanalog states in the residual nuclei. A description of the experimental details and data analysis is presented. The experimentally observed systematics of reactions leading to DIAS, to nonanalog ground states, and to low-lying 2+ states are described. Lowest-order optical-model calculations of DIAS DCX are compared to the data. Efforts to understand the anomalies by invoking additional reaction-mechanism amplitudes and a higher-order optical potential are described. Calculations of nonanalog DCX reactions leading to J/sup π/ = 0+ states were performed within a distorted-wave impulse-approximation framework. The sensitivities of these calculations to input parameters are discussed. 58 refs., 41 figs., 16 tabs

  7. Multistep processes in charge-exchange reactions

    CERN Document Server

    Demetriou, P; Marianski, B

    2002-01-01

    Cross sections for the charge-exchange sup 6 sup 5 Cu(p, n) sup 6 sup 5 Zn reaction at the incident energy of 27 MeV and the sup 1 sup 0 sup 0 Mo(p, n) sup 1 sup 0 sup 0 Tc reaction at the incident energy of 26 MeV have been calculated using the multistep direct reaction theory of Feshbach, Kerman and Koonin. The theory was modified to include the non-DWBA matrix elements and the isovector collective vibrations according to the prescription of Marcinkowski and Marianski. The results show enhanced contributions from two-, three- and four-step direct reactions in agreement with experiment.

  8. Fine structure of charge exchange lines observed in laboratory plasmas

    Energy Technology Data Exchange (ETDEWEB)

    Ida, K.; Nishimura, S. [National Inst. for Fusion Science, Nagoya (Japan); Kondo, K.

    1997-01-01

    The influence of the fine structure of charge exchange lines appears only at the plasma edge or in the recombining phase where the ion temperature is low enough. The observed spectra in Li III and C VI are consistent with the sum of fine-structure components populated by statistical weights (assuming complete l-mixing) not by direct charge exchange cross sections. Some discrepancy was observed in the intensity ratio of fine-structure components between the observation and calculation for C VI in the recombining phase. The fine-structure of charge exchange lines gives an apparent Doppler shift in plasma rotation velocity measurement using charge exchange spectroscopy. (author)

  9. Extracting electrode space charge limited current: Charge injection into conjugated polyelectrolytes with a semiconductor electrode

    Science.gov (United States)

    Walker, Ethan M.; Lonergan, Mark C.

    2016-05-01

    Conjugated polyelectrolytes and related mixed ionic-electronic conductors (MIECs) are being explored for energy applications including solid-state lighting and photovoltaics. Fundamental models of charge injection into MIECs have been primarily developed for MIECs contacted with highly conductive or metal electrodes (MEs), despite many potential applications involving semiconductors. We theoretically and experimentally demonstrate that an appropriate semiconductor electrode (SE), n-type for electron or p-type of hole injection, can limit injection into MIECs. When the SE is the injecting electrode and is under accumulation, there is little difference from a ME. When the SE acts as the extracting electrode, however, injection into the MIEC can be limited because a fraction of any applied bias must support charge depletion in the semiconductor rather than charge injection into the MIEC. In a ME/MIEC/SE system, this can lead to significant asymmetry in current-voltage and injected charge-voltage behavior.

  10. Analysis of JET charge exchange spectra using neural networks

    International Nuclear Information System (INIS)

    Active charge exchange spectra representing the local interaction of injected neutral beams and fully stripped impurity ions are hard to analyse due to strong blending with passive emission from the plasma edge. As a result, the deduced plasma parameters (e.g. ion temperature, rotation velocity, impurity density) cannot always be determined unambiguously. Also, the speed of the analysis is limited by the time consuming nonlinear least-squares minimization procedure. In practice, semi-manual analysis is necessary and fast, automatic analysis, based on currently used techniques, does not seem feasible. In this paper the development of a robust and accurate analysis procedure based on multi-layer perceptron (MLP) neural networks is described. This procedure is fully automatic and fast, thus enabling a real-time analysis of charge exchange spectra. Accuracy has been increased in several ways as compared to earlier straightforward neural network implementations and is comparable to a standard least-squares based analysis. Robustness is achieved by using a combination of different confidence measures. A novel technique for the creation of training data, suitable for high-dimensional inverse problems has been developed and used extensively. A new method for fast calculation of error bars directly from the hidden neurons in a MLP network is also described, and used as part of the confidence calculations. For demonstration purposes, a real-time ion temperature profile diagnostic based on this work has been implemented. (author)

  11. Analysis of JET charge exchange spectra using neural networks

    International Nuclear Information System (INIS)

    Active charge exchange spectra representing the local interaction of injected neutral beams and fully stripped impurity ions are hard to analyse due to the strong blending with passive emission from the plasma edge. As a result, the deduced plasma parameters (e.g. ion temperature, rotation velocity, impurity density) can not always be determined unambiguously. Also, the speed of the analysis is limited by the time consuming non-linear least-squares minimisation procedure. In practice, semi-manual analysis is necessary, and fast, automatic analysis, based on currently used techniques, does not seem feasible. In this paper the development of a robust and accurate analysis procedure based on Multi Layer Perception (MLP) neural networks is described. This procedure is fully automatic and fast, thus enabling a real-time analysis of charge exchange spectra. Accuracy has been increased in several ways as compared to earlier straight-forward neural network implementations and is comparable to a standard least squares based analysis. Robustness is achieved by using a combination of different confidence measures. A novel technique for the creation of training data, suitable for high dimensional inverse problems has been developed, and used extensively. A new method for fast calculation of error bars directly from the hidden neurons in a MLP network is also described, and used as part of the confidence calculations. For demonstration purposes, a real-time ion temperature profile diagnostic based on this has been implemented. (author)

  12. Suzaku Observations of Charge Exchange Emission from Solar System Objects

    Science.gov (United States)

    Ezoe, Y.; Fujimoto, R.; Yamasaki, N. Y.; Mitsuda, K.; Ohashi, T.; Ishikawa, K.; Oishi, S.; Miyoshi, Y; Terada, N.; Futaana, Y.; Porter, F. S.; Brown, G. V.

    2012-01-01

    Recent results of charge exchange emission from solar system objects observed with the Japanese Suzaku satellite are reviewed. Suzaku is of great importance to investigate diffuse X-ray emission like the charge exchange from planetary exospheres and comets. The Suzaku studies of Earth's exosphere, Martian exosphere, Jupiter's aurorae, and comets are overviewed.

  13. Development of the charge exchange type beam scraper system at the J-PARC

    Science.gov (United States)

    Okabe, K.; Yamamoto, K.; Kinsho, M.

    2016-03-01

    Improvement in injection beam quality at the Japan Proton Accelerator Research Complex 3-GeV rapid cycle synchrotron is to mitigate beam loss at the injection section. We developed a charge-exchange type scraper system with a thin carbon foil to collimate the beam halo in the injection beam line of the synchrotron. The key issue to realize the scraper is a reduction of the beam loss induced by the multiple-scattering effect of charge-exchange foil placed at the scraper head. In order to determine the adequate foil thickness, a charge-exchange efficiency of a carbon foil and particle-tracking simulation study of the collimated beam have been performed assuming a realistic halo at the scraper section. Using the results of this study, we chose the thickness of a 520 μg /cm2 as the scraper foils to mitigate radiation dose around the L3BT scraper section. A charge-exchange scraper system that prevents the emission of radioactive fragments of the carbon foil was build. The system was put into operation to prove its effectiveness in eliminating the beam halo. From the result of a preliminary beam experiments, we confirmed that the installed scrapers eliminate a transverse beam tail or halo. After two days of operation with beam collimation, the radiation dose level around the scraper section was a tolerable one for the hands-on maintenance.

  14. X-ray emission from charge exchange of highly-charged ions in atoms and molecules

    Science.gov (United States)

    Greenwood, J. B.; Williams, I. D.; Smith, S. J.; Chutjian, A.

    2000-01-01

    Charge exchange followed by radiative stabilization are the main processes responsible for the recent observations of X-ray emission from comets in their approach to the Sun. A new apparatus was constructed to measure, in collisions of HCIs with atoms and molecules, (a) absolute cross sections for single and multiple charge exchange, and (b) normalized X-ray emission cross sections.

  15. Proceedings of the LAMPF workshop on pion double charge exchange

    International Nuclear Information System (INIS)

    Experimental and theoretical aspects of double-analog, nonanalog, and continuum pion double charge exchange in the 50- to 310-MeV energy range are covered. Separate abstracts were prepared for 22 papers in these proceedings

  16. Charge exchange between singly ionized helium ions

    International Nuclear Information System (INIS)

    The plane-wave Born approximation was used to evaluate the charge transfer cross sections for the reaction He+ + He+ → He++ + He. The charge transfer cross section is graphed as a function of incident energy and compared with experimental measurements

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

    Science.gov (United States)

    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.

  18. Charge exchange emission from solar wind helium ions

    NARCIS (Netherlands)

    Bodewits, D; Hoekstra, R; Seredyuk, B; McCullough, RW; Jones, GH; Tielens, AGGM

    2006-01-01

    Charge exchange X-ray and far-ultraviolet (FUV) aurorae can provide detailed insight into the interaction between solar system plasmas. Using the two complementary experimental techniques of photon emission spectroscopy and translation energy spectroscopy, we have studied state-selective charge exch

  19. Impurity charge-exchange processes in Tokamak plasmas

    International Nuclear Information System (INIS)

    Charge-exchange reactions between multiply-charged impurity ions and neutral hydrogen isotopes are considered. Ionization equilibrium and radiative losses are evaluated for oxygen and iron in the presence of either 'thermal' or 'beam' neutrals. The influence of 'thermal' neutrals on recently reported results from ohmically heated TFR discharges is also discussed

  20. Probing nuclear correlations with pion-nucleus double charge exchange

    International Nuclear Information System (INIS)

    In this paper we have calculated the lowest order pion double charge reaction mechanism using shell model wavefunctions of medium weight nuclei. We have the sequential reaction mechanism in which the pion undergoes two single-charge exchange scatterings on the valence neutrons. The distortion of the incoming, intermediate, and outgoing pion are included. The closure approximation is made for the intermediate states with an average excitation energy used in the pion propagator. The double-charge exchange is assumed to take place on the valence nucleons which are assumed to be in one spherical shell model orbital. 34 refs., 5 figs., 3 tabs

  1. Charge exchange of a polar molecule at its cation

    International Nuclear Information System (INIS)

    The Landau-Herring method is used to derive an analytic expression for the one-electron exchange interaction of a polar molecule with its positively charged ion, induced by a σ-electron. Analogously to the classical Van der Pole method, the exchange interaction potential is averaged over the rotational states of colliding particles. The resonant charge-transfer cross section is calculated, and the effect of the dipole moments of the core on the cross section is analyzed. It is shown that allowance for the dependence of the exchange potential on the orientation of the dipole moments relative to the molecular axis may change the dependence of the cross section on the velocity of colliding particles, which is typical of the resonant charge exchange, from the resonance to the quasi-resonance dependence.

  2. Charge exchange X-rays from the heliosheath

    Science.gov (United States)

    Medvedev, M. V.; Robertson, I. P.; Cravens, T. E.; Zank, G. P.; Florinski, V.

    2006-09-01

    X-rays are produced throughout the heliosphere as a consequence of charge transfer collisions between heavy solar wind ions and neutral atoms. After such a collision the solar wind ion is left in a highly excited state and emits extreme ultraviolet and soft X-ray photons. In the outer heliosphere, solar wind charge exchange X-ray emission is mainly due to charge exchange with neutral interstellar hydrogen. We have combined MHD simulations with a comprehensive charge exchange computation code. We trace the full evolution of solar wind ions along stream line in order to produce three-dimensional emissivities and, subsequently, two-dimensional X-ray brightness and spectral maps of the heliosphere as would be observed from the outside. The model treats both the collisionally thin and the collisionally thick regimes. This model can be a diagnostic tool for studying stellar wind properties of nearby Sun-like stars.

  3. Current Injection Attack against the KLJN Secure Key Exchange

    OpenAIRE

    Chen, Hsien-Pu; Mohammad, Muneer; Kish, Laszlo B.

    2015-01-01

    The Kirchhoff-law-Johnson-noise (KLJN) scheme is a statistical/physical secure key exchange system based on the laws of classical statistical physics to provide unconditional security. We used the LTSPICE industrial cable and circuit simulator to emulate one of the major active (invasive) attacks, the current injection attack, against the ideal and a practical KLJN system, respectively. We show that two security enhancement techniques, namely, the instantaneous voltage/current comparison meth...

  4. Study of nuclei' excitation in the charge exchange reactions (Draft)

    International Nuclear Information System (INIS)

    Carried out experimental and theoretical studies show, that in the nuclear charge exchange reactions there is an unique ability for study both properties and behavior of the delta-isobar in the excited nuclear environment. However for theoretical analysis of these reactions it is necessary have experimental data on nuclei charge exchange on free nucleons. It is offered the experiment of measurement dependence of inclusive cross section of the tritium nuclei charge exchange in 3He nuclei on hydrogen from transferred energy. This reaction is isotopically dependent on 3He nuclei in tritons charge exchange reaction on neutrons. Aim of proposed experiment is checking of a hypothesis believability about the delta-isobar excitation in flying nucleus, and measurement of the process intensity. Peculiarity of this experiment is application of relativistic tritons beams formed from accelerated fragments of 4He nuclei. Experimental facility presents of combination of two one-arm spectrometers: first one - time-flying spectrometer for measurement tritium nuclei impulse in beam to target with accuracy 0.3 % for 6 GeV/s and identification of tritium nuclei, the second one - magnetic spectrometer for identification and measurement of 3He nuclei impulse forming in the result of the charge exchange reaction

  5. A charge exchange chamber with built-in focusing

    International Nuclear Information System (INIS)

    This invention concerns a charge exchange chamber with built-in focusing enabling a beam of low divergence neutrals to be obtained from a beam of ions of a given energy. The ion beam enters the charge exchange chamber filled with a neutral gas under pressure, the effect of which is an exchange of charges between the ions and the neutral molecules or atoms of the gas. The positive ions are substantially sent along the axis of the enclosure, characterised in that it includes electric facilities for concentrating the ions of the beam near this axis. These electric facilities are composed of a series of grids perpendicular to the direction of the ion jet, grids that are transparent and of negative potential and the potential of each of these grids increases in absolute value along the path of the ion jet in the enclosure

  6. Charge-exchange giant resonances as probes of nuclear structure

    International Nuclear Information System (INIS)

    Giant resonances populated in charge-exchange reactions can reveal detailed information about nuclear structure properties, in spite of their apparent featurelessness. The (p,n) and (n,p) reactions - as well as their analog reactions - proceed via the same nuclear matrix element as beta decay. Thereby, they are useful for probing electroweak properties in nuclei, especially for those not accessible to beta decay. The nuclear physics aspects of double beta decay might be investigated in double charge-exchange reactions. detailed nuclear structure information, such as the presence of ground-state correlations, can be revealed via identification of 'first-forbidden' transitions. In addition, astrophysics aspects and halo properties of nuclei have been investigated in charge exchange. Finally, these experiments have questioned our knowledge of the absolute strength of the strong interaction

  7. Charge-exchange giant resonances as probes of nuclear structure

    Energy Technology Data Exchange (ETDEWEB)

    Blomgren, J. [Uppsala Univ., (Sweden). Dept. of Neutron Research

    2001-09-01

    Giant resonances populated in charge-exchange reactions can reveal detailed information about nuclear structure properties, in spite of their apparent featurelessness. The (p,n) and (n,p) reactions - as well as their analog reactions - proceed via the same nuclear matrix element as beta decay. Thereby, they are useful for probing electroweak properties in nuclei, especially for those not accessible to beta decay. The nuclear physics aspects of double beta decay might be investigated in double charge-exchange reactions. detailed nuclear structure information, such as the presence of ground-state correlations, can be revealed via identification of 'first-forbidden' transitions. In addition, astrophysics aspects and halo properties of nuclei have been investigated in charge exchange. Finally, these experiments have questioned our knowledge of the absolute strength of the strong interaction.

  8. Charge injection and transport in fluorene-based copolymers.

    Science.gov (United States)

    Fong, Hon Hang; Malliaras, George G.; Lu, Tianjian; Dunlap, David

    2007-03-01

    Fluorene-based copolymer is considered to be one of the most promising hole transporting and blue light-emitting conjugated polymers used in polymeric light-emitting diodes (PLEDs). Time-of-flight (TOF) technique has been employed to evaluate the charge drift mobility under a temperature range between 200 - 400 K at the thick film regime (1-10 micron). Meanwhile, contact ohmicity is studied by Dark Current Space Charge Limited Conduction (DISCLC) technique. Charge injection efficiencies from different electrical contacts are also studied and the corresponding injection barriers are independently investigated by photoemission and electroabsorption spectroscopies. Results show that the copolymers exhibit non-dispersive charge transport behavior and possess superior mobilities of up to 0.01cm^2V-1s-1 while single-carrier devices from various electrical contacts such as PEDOT:PSS are varied, depending on the chemical structure of amine component in the fluorene-triarylamine copolymers. Results will shed light on the enhancement of device efficiency and stability in the future polymer electronic devices.

  9. Charge Exchange Spectra of Hydrogenic and He-like Iron

    CERN Document Server

    Wargelin, B J; Neill, P A; Olson, R E; Scofield, J H

    2005-01-01

    We present H-like Fe XXVI and He-like Fe XXV charge-exchange spectra resulting from collisions of highly charged iron with N2 gas at an energy of 10 eV/amu in an electron beam ion trap. Although individual high-n emission lines are not resolved in our measurements, we observe that the most likely level for Fe25+ --> Fe24+ electron capture is n~9, in line with expectations, while the most likely value for Fe26+ --> Fe25+ charge exchange is significantly higher. In the Fe XXV spectrum, the K-alpha emission feature dominates, whether produced via charge exchange or collisional excitation. The K-alpha centroid is lower in energy for the former case than the latter (6666 versus 6685 eV, respectively), as expected because of the strong enhancement of emission from the forbidden and intercombination lines, relative to the resonance line, in charge-exchange spectra. In contrast, the Fe XXVI high-n Lyman lines have a summed intensity greater than that of Ly-alpha, and are substantially stronger than predicted from the...

  10. Charge Exchange Reaction in Dopant-Assisted Atmospheric Pressure Chemical Ionization and Atmospheric Pressure Photoionization

    Science.gov (United States)

    Vaikkinen, Anu; Kauppila, Tiina J.; Kostiainen, Risto

    2016-04-01

    The efficiencies of charge exchange reaction in dopant-assisted atmospheric pressure chemical ionization (DA-APCI) and dopant-assisted atmospheric pressure photoionization (DA-APPI) mass spectrometry (MS) were compared by flow injection analysis. Fourteen individual compounds and a commercial mixture of 16 polycyclic aromatic hydrocarbons were chosen as model analytes to cover a wide range of polarities, gas-phase ionization energies, and proton affinities. Chlorobenzene was used as the dopant, and methanol/water (80/20) as the solvent. In both techniques, analytes formed the same ions (radical cations, protonated molecules, and/or fragments). However, in DA-APCI, the relative efficiency of charge exchange versus proton transfer was lower than in DA-APPI. This is suggested to be because in DA-APCI both dopant and solvent clusters can be ionized, and the formed reagent ions can react with the analytes via competing charge exchange and proton transfer reactions. In DA-APPI, on the other hand, the main reagents are dopant-derived radical cations, which favor ionization of analytes via charge exchange. The efficiency of charge exchange in both DA-APPI and DA-APCI was shown to depend heavily on the solvent flow rate, with best efficiency seen at lowest flow rates studied (0.05 and 0.1 mL/min). Both DA-APCI and DA-APPI showed the radical cation of chlorobenzene at 0.05-0.1 mL/min flow rate, but at increasing flow rate, the abundance of chlorobenzene M+. decreased and reagent ion populations deriving from different gas-phase chemistry were recorded. The formation of these reagent ions explains the decreasing ionization efficiency and the differences in charge exchange between the techniques.

  11. Measurement of absorption and charge exchange of $\\pi^+$ on carbon

    CERN Document Server

    Ieki, K; Berkman, S; Bhadra, S; Cao, C; de Perio, P; Hayato, Y; Ikeda, M; Kanazawa, Y; Kim, J; Kitching, P; Mahn, K; Nakaya, T; Nicholson, M; Olchanski, K; Rettie, S; Tanaka, H A; Wilking, M J; Tobayama, S; Yamauchi, T; Yen, S; Yokoyama, M

    2015-01-01

    The combined cross section for absorption and charge exchange interactions of positively charged pions with carbon nuclei for the momentum range 200 MeV/c to 300 MeV/c have been measured with the DUET experiment at TRIUMF. The uncertainty is reduced by nearly half compared to previous experiments. This result will be a valuable input to existing models to constrain pion interactions with nuclei.

  12. Method and Circuit for Injecting a Precise Amount of Charge onto a Circuit Node

    Science.gov (United States)

    Hancock, Bruce R. (Inventor)

    2016-01-01

    A method and circuit for injecting charge into a circuit node, comprising (a) resetting a capacitor's voltage through a first transistor; (b) after the resetting, pre-charging the capacitor through the first transistor; and (c) after the pre-charging, further charging the capacitor through a second transistor, wherein the second transistor is connected between the capacitor and a circuit node, and the further charging draws charge through the second transistor from the circuit node, thereby injecting charge into the circuit node.

  13. Current Injection Attack against the KLJN Secure Key Exchange

    CERN Document Server

    Chen, Hsien-Pu; Kish, Laszlo B

    2015-01-01

    The Kirchhoff-law-Johnson-noise (KLJN) scheme is a statistical/physical secure key exchange system based on the laws of classical statistical physics to provide unconditional security. We used the LTSPICE industrial cable and circuit simulator to emulate one of the major active (invasive) attacks, the current injection attack, against the ideal and a practical KLJN system, respectively. We show that two security enhancement techniques, namely, the instantaneous voltage/current comparison method, and a simple privacy amplification scheme, independently and effectively eliminate the information leak and successfully preserve the system's unconditional security.

  14. Charge exchange between hydrogen atoms and fully stripped heavy ions

    International Nuclear Information System (INIS)

    Charge exchange between multicharged ions and background atomic and molecular gases represents one of the limitations to the attainment of high charge states in heavy ion sources, particularly containment sources. An attempt is made to study systematically a particularly simple but in many respects representative class of such reactions, namely charge transfer between atomic hydrogen and fully stripped heavy ions. Approximate cross sections for these processes in the low keV range of collision energies were obtained using a multistate Landau--Zener method. The energy and Z dependences of the cross sections are discussed

  15. Performance study of the TFTR diagnostic neutral beam for active charge exchange measurements

    International Nuclear Information System (INIS)

    A neutral beam source will be incorporated in the Tokamak Fusion Test Reactor (TFTR) charge exchange diagnostic to provide a time modulated, spatially localized enhancement of the charge exchange efflux. Two autonomous Charge Exchange Neutral Analyzer (CENA) systems are being designed for the TFTR. One system measures the plasma ion temperature along twelve vertical line-of-sight chords spaced approximately equidistantly across the torus minor diameter. The other system is dedicated primarily to measurement of ion phenomena associated with neutral beam injection heating and has a fan-like field of view along eight sight-lines in the equitorial plane. The neutral beam is steerable in order to access the viewing field of both CENA systems, though in general not simultaneously. The performance of the diagnostic neutral beam is evaluated to determine the optimal beam specifications for active charge exchange measurements. Using the optimal beam design parameters, the efficacy of the neutral doping is examined for both CENA systems over the envisioned range of the TFTR plasma density and temperature

  16. Fundamental Investigation of Charge Injection Type of Electrostatic Oil Filter

    Science.gov (United States)

    Tran, Khanh Duong; Yanada, Hideki

    This paper deals with the effects of mechanical factors on the filtration speed of a charge injection type of electrostatic oil filter. The new filter has been proposed by Yanada and his coworkers and it has been demonstrated that the filtration speed can be increased to a great or some degree by injecting charges into oils, but the experimental condition was limited. In this paper, the effects of the number of the projections, the electrode spacing, the applied voltage and the oil temperature on the filtration speed are examined using a simple filter model and various types of oil. In order to discuss the effects of those mechanical factors on the filtration speed, numerical simulation of electrostatic field between electrodes is done and the oil flow caused between the electrodes due to ion drag phenomenon, called the ion drag flow in the paper, is observed using a charge coupled devise (CCD) camera and is analyzed using a particle image velocimetry (PIV) technique. The experiments and numerical simulation make clear the effects of the mechanical factors on the filtration speed. An optimal electrode configuration and operating condition are found out.

  17. Charge exchange and chemical reactions with trapped Th3+

    International Nuclear Information System (INIS)

    We have measured the reaction rates of trapped, buffer gas cooled Th3+ and various gases and have analyzed the reaction products using trapped ion mass spectrometry techniques. Ion trap lifetimes are usually limited by reactions with background molecules, and the high electron affinity of multiply charged ions such as Th3+ make them more prone to loss. Our results show that reactions of Th3+ with carbon dioxide, methane, and oxygen all occur near the classical Langevin rate, while reaction rates with argon, hydrogen, and nitrogen are orders of magnitude lower. Reactions of Th3+ with oxygen and methane proceed primarily via charge exchange, while simultaneous charge exchange and chemical reaction occurs between Th3+ and carbon dioxide. Loss rates of Th3+ in helium are consistent with reaction with impurities in the gas. Reaction rates of Th3+ with nitrogen and argon depend on the internal electronic configuration of the Th3+.

  18. Charge Exchange and Chemical Reactions with Trapped Th$^{3+}$

    CERN Document Server

    Churchill, L R; Chapman, M S

    2010-01-01

    We have measured the reaction rates of trapped, buffer gas cooled Th$^{3+}$ and various gases and have analyzed the reaction products using trapped ion mass spectrometry techniques. Ion trap lifetimes are usually limited by reactions with background molecules, and the high electron affinity of multiply charged ions such as Th$^{3+}$ make them more prone to loss. Our results show that reactions of Th$^{3+}$ with carbon dioxide, methane, and oxygen all occur near the classical Langevin rate, while reaction rates with argon, hydrogen, and nitrogen are orders of magnitude lower. Reactions of Th$^{3+}$ with oxygen and methane proceed primarily via charge exchange, while simultaneous charge exchange and chemical reaction occurs between Th$^{3+}$ and carbon dioxide. Loss rates of Th$^{3+}$ in helium are consistent with reaction with impurities in the gas. Reaction rates of Th$^{3+}$ with nitrogen and argon depend on the internal electronic configuration of the Th$^{3+}$.

  19. Progress in the pellet charge exchange diagnostics on LHD and local neutral particle spectra analysis

    International Nuclear Information System (INIS)

    Production, confinement and thermalization of high-energy particles are the fundamental issues in fusion plasma ion kinetics. The ion distribution function ft(ν, θ, t) and its evolution under the ion cyclotron heating (ICH) and neutral beam injection (NBI) are studied by energy resolved charge exchange neutral particle flux measurements. For helical systems, such as LHD, local diagnostics are required due to the complex 3D magnetic configuration. First radially resolved measurements of local H0 atomic energy spectra have been made on LHD by the pellet charge exchange (PCX) method with a Compact Neutral Particle Analyzer (CNPA). The diagnostic technique, the initial measurement results in the range 10-100 keV and the data analysis are described. (author)

  20. Switchable Charge Injection Barrier in an Organic Supramolecular Semiconductor.

    Science.gov (United States)

    Gorbunov, Andrey V; Haedler, Andreas T; Putzeys, Tristan; Zha, R Helen; Schmidt, Hans-Werner; Kivala, Milan; Urbanavičiu̅tė, Indre; Wübbenhorst, Michael; Meijer, E W; Kemerink, Martijn

    2016-06-22

    We disclose a supramolecular material that combines semiconducting and dipolar functionalities. The material consists of a discotic semiconducting carbonyl-bridged triarylamine core, which is surrounded by three dipolar amide groups. In thin films, the material self-organizes in a hexagonal columnar fashion through π-stacking of the molecular core and hydrogen bonding between the amide groups. Alignment by an electrical field in a simple metal/semiconductor/metal geometry induces a polar order in the interface layers near the metal contacts that can be reversibly switched, while the bulk material remains nonpolarized. On suitably chosen electrodes, the presence of an interfacial polarization field leads to a modulation of the barrier for charge injection into the semiconductor. Consequently, a reversible switching is possible between a high-resistance, injection-limited off-state and a low-resistance, space-charge-limited on-state. The resulting memory diode shows switchable rectification with on/off ratios of up to two orders of magnitude. This demonstrated multifunctionality of a single material is a promising concept toward possible application in low-cost, large-area, nonvolatile organic memories. PMID:27246280

  1. X-UV SPECTROSCOPY OF LOW ENERGY CHARGE EXCHANGE COLLISIONS

    OpenAIRE

    Bliman, S.; Bonnet, J.; Bonnefoy, M.; Dousson, S.; Fleury, A.; Hitz, D.; Lu Dac, T.; Mayo, M.

    1986-01-01

    In the field of hot plasmas, it is well known that a knowledge of the relation between collisions and radiation is needed. We show that considering the charge exchange process in which a highly charged, low velocity ion impinges on an atom, we have an X-UV light source allowing new developments. Basically, at velocities less than the atomic unit (vo = 2.2 108 cm/s), the capture of one electron will leave the projectile ion in an excited state. The most probably populated level np is dependant...

  2. Controlled Electron Injection into Plasma Accelerators and Space Charge Estimates

    International Nuclear Information System (INIS)

    Plasma based accelerators are capable of producing electron sources which are ultra-compact (a few microns) and high energies (up to hundreds of MeVs) in much shorter distances than conventional accelerators. This is due to the large longitudinal electric field that can be excited without the limitation of breakdown as in RF structures.The characteristic scale length of the accelerating field is the plasma wavelength and for typical densities ranging from 1018 - 1019 cm-3, the accelerating fields and scale length can hence be on the order of 10-100GV/m and 10-40 mu m, respectively. The production of quasimonoenergetic beams was recently obtained in a regime relying on self-trapping of background plasma electrons, using a single laser pulse for wakefield generation. In this dissertation, we study the controlled injection via the beating of two lasers (the pump laser pulse creating the plasma wave and a second beam being propagated in opposite direction) which induce a localized injection of background plasma electrons. The aim of this dissertation is to describe in detail the physics of optical injection using two lasers, the characteristics of the electron beams produced (the micrometer scale plasma wavelength can result in femtosecond and even attosecond bunches) as well as a concise estimate of the effects of space charge on the dynamics of an ultra-dense electron bunch with a large energy spread

  3. Automatic analysis of JET charge exchange spectra using neural networks

    International Nuclear Information System (INIS)

    The analysis of charge exchange recombination spectra represents a very challenging problem due to the presence of many overlapping spectral lines. Conventional approaches are based on iterative least-squares optimization and suffer from the two difficulties of low speed and the need for a good initial approximation to the solution. This latter problem necessitates considerable human supervision of the analysis procedure. It is shown how neural network techniques allow charge exchange data to be analysed very rapidly, to give an approximate solution without the need for supervision. The network approach is well suited to the fast intershot analysis of large volumes of data, and can readily be implemented in dedicated hardware for real-time applications. The neural network can also be used to provide the initial guess for the standard least-squares algorithm when high accuracy is required. (Author)

  4. Pion charge-exchange reactions: The analog state transitions

    International Nuclear Information System (INIS)

    The general features of pion charge-exchange reactions leading to nuclear-isobaric-analog states (IAS) and double-isobaric-analog states (DIAS), as they have emerged from studies over the past ten years, are reviewed. The energy range investigated is 20 to 550 MeV for IAS transitions and 20 to 300 MeV for DIAS transitions. These data are seen to play an important role in characterizing the pion optical potential, in determining the Δ-N interaction in nuclei, and in the study of nucleon correlations in nuclei. Recent progress achieved in understanding the role of such correlations in double-charge-exchange reactions is reviewed. 55 refs., 43 figs., 3 tabs

  5. Microscopic optical potentials - study of charge-exchange reactions

    International Nuclear Information System (INIS)

    The present thesis is engaged in two different aspects of direct nuclear reactions, namely on the one hand in the microscopic calculation of the imaginary optical potential for the elastic alpha-nucleus scattering as well on the other hand in the microscopic analysis of giant resonance states which are excited by (p,n) and (n,p) charge-exchange reactions. In the first part in the framework of the nuclear structure approximation to the optical potential a microscopic calculation of the imaginary part of the optical potential for α40Ca scattering at Esub(α) = 31 and 100 MeV is performed. In the second part the 208Pb(p,n) and 208Pb(n,p) charge-exchange reactions are studied at low ( E 100 MeV) incident energies. (orig./HS)

  6. Improved pellet charge exchange measurements in Large Helical Device

    International Nuclear Information System (INIS)

    The pellet charge exchange technique (PCX), which is a combination of the compact neutral particle analyzer and an impurity pellet, is a unique method to observe the radial energetic particle distribution. There are not only charge exchange reactions between the hydrogen in the pellet and a proton, but also between the partially ionized carbon in the pellet and the proton. The neutralization factor from energetic ion to neutral particle could be deduced from the electron temperature and the electron density of the pellet cloud. The radial profiles of energetic particle distribution were measured and compared in various ion cyclotron resonance heating (ICH) plasmas. The energetic particle flux significantly increased at the resonance layer created by the ICH. PCX provides more precise information about the resonance layer than conventional neutral particle diagnostics. (author)

  7. Elastic scattering and charge exchange reactions with exotic beams

    International Nuclear Information System (INIS)

    The elastic scattering of 6He, 10,11Be secondary beams on a (CH2)3 target and the charge exchange reaction p(6He,6Li)n have been measured. Very good agreement was found for the 6He+12C data with a four-body eikonal scattering model. A microscopic optical potential was used to reproduce the proton-nucleus elastic scattering data. (author)

  8. Elastic and charge exchange scattering of pions from 3He

    International Nuclear Information System (INIS)

    Elastic and charge exchange scatterings of pions from 3He are studied using on optical potential in the momentum representation, which includes the second order effect as well as the nucleon binding correction. These corrections are found to be appreaciable but still not enough to resolve the discrepancy between theoretical calculations and recent experimental data on the reaction 3He(π-, π0)3H. (author)

  9. μ+ charge exchange and muonium formation in low pressure gases

    International Nuclear Information System (INIS)

    Using the basic muon spin rotation technique, the fractions of energetic positive muons thermalizing in diamagnetic environments (fsub(μ)) or as the paramagnetic muonium atom (fsub(Mu)) have been measured in low pressure pure gases (He, Ne, Ar, Kr, Xe, H2, N2, NH3, and CH4) as well as in several gas mixtures (Ne/Xe, Ne/Ar, Ne/NH3, Ne/CH4). In the pure gases, the muonium fractions fsub(Mu) are generally found to be smaller than expected from analogous proton charge exchange studies, particularly in the molecular gases. This is probably due to hot atom reactions of muonium following the charge exchange regime. Comparisons with monium formation in condensed matter as well as positronium formation in gases are also presented. In the gas mixtures, the addition of only a few hundred ppm of a dopant gas, which is exothermic for muonium formation (e.g. Xe), gives rise to an fsub(Mu) characteristic of the pure dopant gas itself, demonstrating the importance of the neutralization process right down to thermal energies. In all cases, the experimental signal amplitudes are found to be strongly pressure dependent, which is interpreted in terms of the time spent by the muon as neutral muonium in the charge exchange regime: tsub(n) < 0.2 ns. This time is generally shorter in the case of molecular gases than in rare gases

  10. Solar System X-rays from Charge Exchange Processes

    Science.gov (United States)

    Lisse, Carey M.; Christian, D. J.; Bhardwaj, A.; Dennerl, K.; Wolk, S. J.; Bodewits, D.; Combi, M. R.; Zurbuchen, T. H.; Lepri, S. T.

    2013-04-01

    The discovery of high energy x-ray emission in 1996 from comet C/1996 B2 (Hyakutake) uncovered a new class of x-ray emitting objects. Subsequent detections of the morphology, spectra, and time dependence of the x-rays from more than 20 comets have shown that the very soft (E charge-exchange interaction between highly charged solar wind minor ions and the comet's extended neutral atmosphere. Many solar system objects are now known to shine in the X-ray, including Venus, Mars, the Moon, the Earth, Jupiter, and Saturn, with total power outputs on the MW - GW scale. Like comets, the X-ray emission from the Earth's geo-corona, the Jovian & Saturnian aurorae, and the Martian halo are thought to be driven by charge exchange between highly charged minor (heavy) ions in the solar wind and gaseous neutral species in the bodies' atmosphere. The non-auroral X-ray emissions from Jupiter, Saturn, and Earth, and those from disks of Mars, Venus, and the Moon are produced by scattering of solar X-rays. The first soft X-ray observations of Earth’s aurora by Chandra shows that it is highly variable, and the giant planet aurorae are fascinating puzzles that are just beginning to yield their secrets and may be the only x-ray sources not driven directly by the Sun in the whole system as well as properties of hot exo-solar Jupiters. Observations of local solar system charge exchange processes can also help inform us about x-rays produced at more distant hot ionized gas/cold neutral gas interfaces, like the heliopause, stellar astrospheres, galactic star forming regions, and starburst galaxies.

  11. Toward charging free plasma etching; Insitu measurement of negative charge injection and charge reduction in a contact hole

    Science.gov (United States)

    Ohmori, Takeshi; Makabe, Toshiaki

    2003-10-01

    It will be essential to develop in-situ diagnostics for damage free plasma etching in the interface under close and complementary cooperation between optical and electric procedure in a top-down nanoscale etching. In our previous paper[1], we have applied an emission selected omputerized tomography close to the wafer exposed to plasma etching, in order to investigate the polarity and the phase of high energy charged particles incident on the wafer, biased deeply by a low frequency source in RIE. A reduction in charging voltage on a contact hole bottom of SiO2 was validated in the pulsed plasma power source in the 2f-CCP in CF_4/Ar, by using a dual measurement system onsisting of a temporal emission CT and a contact hole charging voltage. In the present work, detailed correlational results of the reduction in the charging voltage are shown as a function of phase and amplitude of the single bias pulse at 500 kHz. Discussion is focused both on the injection mechanism of energetic negative charges to the wafer and on the magnitude of the negative charges. As a result, during the off-period 10 us of VHF power source in the dual pulsed 2f-CCP, it is confirmed that; 1)the magnitude of the injected negative charge increases with increasing the on-time of the single bias pulse, and a strong reduction in the charging voltage is performed, 2)a strong negative self-bias-voltage is always kept to have an efficient RIE under energetic positive ion impact on the wafer except for the period of the single bias pulse. Some of predictive story will be also introduced by VicAddress. 1)T.Ohmori, T.K.Goto, T.Kitajima, and T.Makabe, Proc.of Dry Process Symposium 165(2002)Tokyo, and Appl.Phys.Lett.(submitted).

  12. Charge exchange in fluid description of partially ionized plasmas

    CERN Document Server

    Vranjes, J; Luna, M

    2015-01-01

    The effects of charge exchange on waves propagating in weakly ionized plasmas are discussed. It is shown that for low-frequency processes, ions and neutrals should be treated as a single fluid with some effective charge on all of them. We have derived a new momentum equation which should be used in such an environment. As a result, the low-frequency magnetic waves can propagate even if particles are not magnetized, which is entirely due to the charge exchange and the fact that it is not possible to separate particles into two different populations as charged and neutral species. So there can be no friction force between ions and neutrals in the usual sense. The mean force per particle is proportional to the ionization ratio $n_i/(n_i+ n_n)$. Regarding the application of the theory to the Alfven wave propagation in the lower solar atmosphere, the results predict that the plane of displacement of the fluid must change by 90 degrees when an Alfven wave propagates from the area where particles are un-magnetized (...

  13. A photodiode-based neutral particle bolometer for characterizing charge-exchanged fast-ion behavior

    Energy Technology Data Exchange (ETDEWEB)

    Clary, R.; Smirnov, A.; Dettrick, S.; Knapp, K.; Korepanov, S.; Ruskov, E. [Tri Alpha Energy, Inc., Rancho Santa Margarita, California 92688 (United States); Heidbrink, W. W.; Zhu, Y. [University of California-Irvine, Irvine, California 92697 (United States)

    2012-10-15

    A neutral particle bolometer (NPB) has been designed and implemented on Tri Alpha Energy's C-2 device in order to spatially and temporally resolve the charge-exchange losses of fast-ion populations originating from neutral beam injection into field-reversed configuration plasmas. This instrument employs a silicon photodiode as the detection device with an integrated tungsten filter coating to reduce sensitivity to light radiation. Here we discuss the technical aspects and calibration of the NPB, and report typical NPB measurement results of wall recycling effects on fast-ion losses.

  14. A photodiode-based neutral particle bolometer for characterizing charge-exchanged fast-ion behavior.

    Science.gov (United States)

    Clary, R; Smirnov, A; Dettrick, S; Knapp, K; Korepanov, S; Ruskov, E; Heidbrink, W W; Zhu, Y

    2012-10-01

    A neutral particle bolometer (NPB) has been designed and implemented on Tri Alpha Energy's C-2 device in order to spatially and temporally resolve the charge-exchange losses of fast-ion populations originating from neutral beam injection into field-reversed configuration plasmas. This instrument employs a silicon photodiode as the detection device with an integrated tungsten filter coating to reduce sensitivity to light radiation. Here we discuss the technical aspects and calibration of the NPB, and report typical NPB measurement results of wall recycling effects on fast-ion losses. PMID:23126887

  15. Configuration interaction in charge exchange spectra of tin and xenon

    International Nuclear Information System (INIS)

    Charge-state-specific extreme ultraviolet spectra from both tin ions and xenon ions have been recorded at Tokyo Metropolitan University. The electron cyclotron resonance source spectra were produced from charge exchange collisions between the ions and rare gas target atoms. To identify unknown spectral lines of tin and xenon, atomic structure calculations were performed for Sn14+-Sn17+ and Xe16+-Xe20+ using the Hartree-Fock configuration interaction code of Cowan (1981 The Theory of Atomic Structure and Spectra (Berkeley, CA: University of California Press)). The energies of the capture states involved in the single-electron process that occurs in these slow collisions were estimated using the classical over-barrier model.

  16. Design of control system for the 2nd and 3rd charge exchange system in J-PARC 3GeV RCS

    International Nuclear Information System (INIS)

    J-PARC 3GeV Synchrotron Accelerator is using method of charge exchange injection using three carbon foils. In order to achieve this injection, three charge exchange devices installed in this facility. These devices are controlled by one control system. The 2nd and 3rd charge exchange devices are upgrading to increase maintainability and exhaust ability of the vacuum unit, and the control system has reconsidered. Basic policy of redesigning the control system is separated from centralized control system of the three devices, and we reconstruct the control system that independent from the centralized control system. On this condition, we are upgrading of the 2nd and 3rd charge exchange device. It is necessary to redesign the interlock unit about safety, because of being stand-alone control. Now, the error signal of the charge exchange unit consolidates the error signal of three devices, and it operates the Machine Protection System (MPS). Therefore, we needed long time to search occasion why the error happened. However, the MPS will be operated by the error signal on each unit, we hope it makes a difference to search occasion easily. The 2nd and 3rd charge exchange units adopt a simple control system using Yokogawa electric PLC FA-M3. We are designing of the control system with safety that fuses the drive unit and the vacuum unit. This report is about design of the 2nd and 3rd charge exchange unit control system that reconstructed the hardware of their unit. (author)

  17. Charge exchange as a recombination mechanism in high-temperature plasmas

    International Nuclear Information System (INIS)

    Charge exchange with neutral hydrogen is examined as a recombination mechanism for multi-charged impurity ions present in high-temperature fusion plasmas. At sufficiently low electron densities, fluxes of atomic hydrogen produced by either the injection of neutral heating beams or the background of thermal neutrals can yield an important or even dominant recombination process for such ions. Equilibrium results are given for selected impurity elements showing the altered ionization balance and radiative cooling rate produced by the presence of various neutral populations. A notable result is that the stripping of impurities to relatively non-radiative ionization states with increasing electron temperature can be postponed or entirely prevented by the application of intense neutral beam heating power. A time dependent calculation modelling the behavior of iron in recent PLT tokamak high power neutral beam heating experiments is also presented

  18. Ocean Remote Sensing With A Charge Injection Device (CID) Array

    Science.gov (United States)

    Stewart, S. E.; Buntzen, R. R.

    1984-09-01

    Ocean optical data has been remotely collected using the Advanced Solidstate Array Spectroradiometer (ASAS). ASAS is a multispectral pushbroom scanner with 32 channels extending from 400 to 850 nm. It is built around a 32 by 512 element charge injection device (CID) array with enhanced sensitivity in the blue. Twelve-bit digital output with variable gain and offset in the pre-amp and low system noise give this scanner the ability to pick up low level subsurface upwelling light from the ocean. The scanner was built by General Electric and the NASA Johnson Space Center with optics from TRW under a Naval Ocean Systems Center program for ocean remote sensing. It was first flown with the detector uncooled in September of 1983 at the Naval Coastal Systems Center in Panama City, Florida. Preliminary analysis of the data indicates a signal-to-noise ratio of at least 200 to 1. Subsequent image processing and refinements in the scanner hardware promise to improve this figure significantly. Details of the scanner design, calibration, and noise reduction will be presented. The scan-ner's potential for use in shallow water bottom mapping and chlorophyll determination will be discussed. Fi-nally, projected improvements in the scanner and its performance will be described.

  19. Nucleon charge-exchange reactions at intermediate energy

    Energy Technology Data Exchange (ETDEWEB)

    Alford, W.P. [Western Ontario Univ., London, ON (Canada). Dept. of Physics]|[TRIUMF, Vancouver, BC (Canada); Spicer, B.M. [Melbourne Univ., Parkville, VIC (Australia). School of Physics

    1997-12-31

    An historical review of the development of ideas pertaining to Gamow-Teller giant resonances is given, and a description of the emergence of techniques for the study of charge exchange reactions - particularly the technical advances which yielded the recent volume of new date. The present status of charge exchange reactions is reviewed and assessed. Evidence is presented from the {sup 14}C(p,n) reaction for the dominance of the spin-isospin component of the nucleon-nucleon interaction in intermediate energy reactions. In (p,n) reactions the Gamow-Teller giant resonance dominates the spectra, with higher multipoles contributing. By contrast, in (n,p) reactions in the heavier nuclei, the Gamow-Teller transitions are substantially Pauli-blocked and the spin dipole resonance dominates, with contributions from higher multipoles. Discussions of the multipole decomposition process, used to obtain from the data the contributions of the different multipoles, and the contributions of the multipoles, are given. 226 refs., 19 figs.

  20. Charge exchange measurements of ion behavior in the ISX tokamak

    International Nuclear Information System (INIS)

    Analysis of charge exchange neutrals is the standard method for measuring ion behavior in tokamak plasmas. Limitations of this technique, which arise in dense and neutral-beam-heated plasmas, are discussed. Two refinements that address these limitations are described: a neutral particle analyzer, which incorporates both mass and energy resolution to distinguish different ion components such as the fast and thermal ions in beam-heated plasmas, and an improved data analysis procedure, which accounts for the effects of profiles and neutral attenuation in dense plasmas. A simple two-dimensional Monte Carlo neutral transport code was developed and used to investigate the effects of toroidally asymmetric neutral density profiles. Applications of these methods to experiments in the Impurity Study Experiment (ISX) are discussed; they include energy confinement studies on ISX-A, natural beam heating and high beta studies on ISX-B, and pellet fueling studies on ISX-B

  1. Delta excitation in nuclei: the lesson of charge exchange reactions

    International Nuclear Information System (INIS)

    We present an attempt of theoretical interpretation of charge exchange reactions on nuclei in the region of the delta resonance. Special care is taken to insure consistency with the constraints from pion and photon excitation channels. Good agreement with measured spectra can be obtained for all types of targets and incident ions except for polarized deuterons data which appear hardly reconcilable with the others within our interpretation. Despite the peripheral character of these reactions, a sizeable part of the observed downward shift of the resonance is possibly ascribable to a yet undetected collective mode of the nucleus at high excitation, the pionic branch. Our limited commitment is due to uncomplete knowledge of the NN → N Δ interaction and the transition form factors of the probing ions which has been palliated by some phenomenology

  2. Charge Exchange Losses and Stochastic Acceleration in the Solar Wind

    CERN Document Server

    Kenny, Ciaran

    2016-01-01

    Stochastic acceleration of particles under a pressure balance condition can accommodate the universal $p^{-5}$ spectra observed under many different conditions in the inner heliosphere. In this model, in order to avoid an infinite build up of particle pressure, a relationship between the momentum diffusion of particles and the adiabatic deceleration in the solar wind must exist. This constrains both the spatial and momentum diffusion coefficients and results in the $p^{-5}$ spectrum in the presence of adiabatic losses in the solar wind. However, this theory cannot explain the presence of such spectra beyond the termination shock, where adiabatic deceleration is negligible. To explain this apparent discrepancy, we include the effect of charge exchange losses, resulting in new forms of both the spatial and momentum diffusion coefficients that have not previously been considered. Assuming that the turbulence is of a large-scale compressible nature, we find that a balance between momentum diffusion and losses can...

  3. Coherent pion production in heavy ion charge exchange reactions

    International Nuclear Information System (INIS)

    We report the first observation of coherent pion production induced by a heavy ion charge exchange reaction. The (12C,12N) reaction [D. Bachelier et al., Phys. Lett. B 172 (1986) 23; M. Roy-Stephan et al., Nucl. Phys. A 488 (1988) 178] at 1.1 GeV/nucleon has been used to shine negative (off-shell) pions on nuclei and observe (on-shell) pions, leaving the target nucleus in its ground state. The experiment was performed at the Laboratoire National Saturne with the SPES4-π setup [Laurent Farhi PHD thesis IPNO-T97-12, Universite d'Orsay, 1997; Rasmus Dahl Ph.D., Niels Bohr Institutet, Copenhagen (1999)

  4. Deuteron-proton charge exchange reaction at small transfer momentum

    CERN Document Server

    Ladygina, N B

    2004-01-01

    The charge-exchange reaction pd -> npp at 1 GeV projectile proton energy is studied. This reaction is considered in a special kinematics, when the transfer momentum from the beam proton to fast outgoing neutron is close to zero. Our approach is based on the Alt-Grassberger-Sandhas formulation of the multiple-scattering theory for the three-nucleon system. The matrix inversion method has been applied to take account of the final state interaction (FSI) contributions. The differential cross section, tensor analyzing power $C_{0,yy}$, vector-vector $C_{y,y}$ and vector-tensor $C_{y,xz}$ spin correlation parameters of the initial particles are presented. It is shown, that the FSI effects play a very important role under such kinematical conditions. The high sensitivity of the considered observables to the elementary nucleon-nucleon amplitudes has been obtained.

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

    International Nuclear Information System (INIS)

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

  6. Charge Accretion Rate and Injection Radius of Ionized-Induced Injections in Laser Wakefield Accelerators

    Science.gov (United States)

    Zeng, Ming; Chen, Min; Sheng, Zheng-Ming

    2016-03-01

    Ionization-induced injection has recently been proved to be a stable injection method with several advantages in laser wakefield accelerators. However, the controlling of this injection process aiming at producing high quality electron beams is still challenging. In this paper, we examine the ionization injection processes and estimate the injection rate with two-dimensional particle-in-cell simulations. The injection rate is shown to increase linearly with the high-Z gas density as long as its ratio is smaller than some threshold in the mix gases. It is also shown that by changing the transverse mode of the driving lasers one can control the injection rate.

  7. Tuning The Optical, Charge Injection, and Charge Transport Properties of Organic Electronic Devices

    Science.gov (United States)

    Zalar, Peter

    Since the early 1900's, synthetic insulating polymers (plastics) have slowly taken over the role that traditional materials like wood or metal have had as basic components for construction, manufactured goods, and parts. Plastics allow for high throughput, low temperature processing, and control of bulk properties through molecular modifications. In the same way, pi-conjugated organic molecules are emerging as a possible substitute for inorganic materials due to their electronic properties. The semiconductive nature of pi-conjugated materials make them an attractive candidate to replace inorganic materials, primarily due to their promise for low cost and large-scale production of basic semiconducting devices such as light-emitting diodes, solar cells, and field-effect transistors. Before organic semiconductors can be realized as a commercial product, several hurdles must be cleared. The purpose of this dissertation is to address three distinct properties that dominate the functionality of devices harnessing these materials: (1) optical properties, (2) charge injection, and (3) charge transport. First, it is shown that the electron injection barrier in the emissive layer of polymer light-emitting diodes can be significantly reduced by processing of novel conjugated oligoelectrolytes or deoxyribonucleic acid atop the emissive layer. Next, the charge transport properties of several polymers could be modified by processing them from solvents containing small amounts of additives or by using regioregular and enantiopure chemical structures. It is then demonstrated that the optical and electronic properties of Lewis basic polymer structures can be readily modified by interactions with strongly electron-withdrawing Lewis acids. Through red-shifted absorption, photoluminescence, and electroluminescence, a single pi-conjugated backbone can be polychromatic. In addition, interaction with Lewis acids can remarkably p-dope the hole transport of the parent polymer, leading to a

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

    International Nuclear Information System (INIS)

    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.

  9. Plasma code for astrophysical charge exchange emission at X-ray wavelengths

    CERN Document Server

    Gu, Liyi; Raassen, A J J

    2016-01-01

    Charge exchange X-ray emission provides unique insights into the interactions between cold and hot astrophysical plasmas. Besides its own profound science, this emission is also technically crucial to all observations in the X-ray band, since charge exchange with the solar wind often contributes a significant foreground component that contaminates the signal of interest. By approximating the cross sections resolved to $n$ and $l$ atomic subshells, and carrying out complete radiative cascade calculation, we create a new spectral code to evaluate the charge exchange emission in the X-ray band. Comparing to collisional thermal emission, charge exchange radiation exhibits enhanced lines from large-$n$ shells to the ground, as well as large forbidden-to-resonance ratios of triplet transitions. Our new model successfully reproduces an observed high-quality spectrum of comet C/2000 WM1 (LINEAR), which emits purely by charge exchange between solar wind ions and cometary neutrals. It demonstrates that a proper charge ...

  10. High spatial and temporal resolution charge exchange recombination spectroscopy on the HL-2A tokamak

    Energy Technology Data Exchange (ETDEWEB)

    Wei, Y. L.; Yu, D. L., E-mail: yudl@swip.ac.cn; Liu, L.; Cao, J. Y.; Sun, A. P.; Ma, Q.; Chen, W. J.; Liu, Yi; Yan, L. W.; Yang, Q. W.; Duan, X. R.; Liu, Yong [Southwestern Institute of Physics, Chengdu 610041 (China); Ida, K. [National Institute for Fusion Science, Toki 509-5292 (Japan); Hellermann, M. von [ITER Diagnostic Team, IO, Route de Vinon sur Verdon, 13115 St Paul lez Durance (France); FOM-Institute for Plasma physics “Rijnhuizen,” Association EURATOM, Trilateral Euregio Cluster, 3430 BE Nieuwegein (Netherlands)

    2014-10-01

    A 32/64-channel charge exchange recombination spectroscopy (CXRS) diagnostic system is developed on the HL-2A tokamak (R = 1.65 m, a = 0.4 m), monitoring plasma ion temperature and toroidal rotation velocity simultaneously. A high throughput spectrometer (F/2.8) and a pitch-controlled fiber bundle enable the temporal resolution of the system up to 400 Hz. The observation geometry and an optimized optic system enable the highest radial resolution up to ~1 cm at the plasma edge. The CXRS system monitors the carbon line emission (C VI, n = 8–7, 529.06 nm) whose Doppler broadening and Doppler shift provide ion temperature and plasma rotation velocity during the neutral beam injection. The composite CX spectral data are analyzed by the atomic data and analysis structure charge exchange spectroscopy fitting (ADAS CXSFIT) code. First experimental results are shown for the case of HL-2A plasmas with sawtooth oscillations, electron cyclotron resonance heating, and edge transport barrier during the high-confinement mode (H-mode)

  11. High spatial and temporal resolution charge exchange recombination spectroscopy on the HL-2A tokamak

    International Nuclear Information System (INIS)

    A 32/64-channel charge exchange recombination spectroscopy (CXRS) diagnostic system is developed on the HL-2A tokamak (R = 1.65 m, a = 0.4 m), monitoring plasma ion temperature and toroidal rotation velocity simultaneously. A high throughput spectrometer (F/2.8) and a pitch-controlled fiber bundle enable the temporal resolution of the system up to 400 Hz. The observation geometry and an optimized optic system enable the highest radial resolution up to ∼1 cm at the plasma edge. The CXRS system monitors the carbon line emission (C VI, n = 8–7, 529.06 nm) whose Doppler broadening and Doppler shift provide ion temperature and plasma rotation velocity during the neutral beam injection. The composite CX spectral data are analyzed by the atomic data and analysis structure charge exchange spectroscopy fitting (ADAS CXSFIT) code. First experimental results are shown for the case of HL-2A plasmas with sawtooth oscillations, electron cyclotron resonance heating, and edge transport barrier during the high-confinement mode (H-mode)

  12. Charge-exchange reaction by Reggeon exchange and W{sup +}W{sup −}-fusion

    Energy Technology Data Exchange (ETDEWEB)

    Schicker, R. [Phys. Inst., University Heidelberg (Germany)

    2015-04-10

    Charge-exchange reactions at high energies are examined. The existing cross section data on the Reggeon induced reaction pp → n + Δ{sup ++} taken at the ZGS and ISR accelerators are extrapolated to the energies of the RHIC and LHC colliders. The interest in the charge-exchange reaction induced by W{sup ±}-fusion is presented, and the corresponding QCD-background is examined.

  13. Efficient barrier for charge injection in polyethylene by silver nanoparticles/plasma polymer stack

    International Nuclear Information System (INIS)

    Charge injection from a metal/insulator contact is a process promoting the formation of space charge in polymeric insulation largely used in thick layers in high voltage equipment. The internal charge perturbs the field distribution and can lead to catastrophic failure either through its electrostatic effects or through energetic processes initiated under charge recombination and/or hot electrons effects. Injection is still ill-described in polymeric insulation due to the complexity of the contact between the polymer chains and the electrodes. Barrier heights derived from the metal work function and the polymer electronic affinity do not provide a good description of the measurements [Taleb et al., IEEE Trans. Dielectr. Electr. Insul. 20, 311–320 (2013)]. Considering the difficulty to describe the contact properties and the need to prevent charge injection in polymers for high voltage applications, we developed an alternative approach by tailoring the interface properties by the silver nanoparticles (AgNPs)/plasma polymer stack, deposited on the polymer film. Due to their small size, the AgNPs, covered by a very thin film of plasma polymer, act as deep traps for the injected charges thereby stabilizing the interface from the point of view of charge injection. After a quick description of the method for elaborating the nanostructured layer near the contact, it is demonstrated how the AgNPs/plasma polymer stack effectively prevents, in a spectacular way, the formation of bulk space charge.

  14. Efficient barrier for charge injection in polyethylene by silver nanoparticles/plasma polymer stack

    Energy Technology Data Exchange (ETDEWEB)

    Milliere, L. [LAPLACE (Laboratoire Plasma et Conversion d' Energie), Université de Toulouse, UPS, INPT, 118 route de Narbonne, F-31062 Toulouse Cedex 9 (France); Makasheva, K., E-mail: kremena.makasheva@laplace.univ-tlse.fr; Laurent, C.; Despax, B.; Teyssedre, G. [LAPLACE (Laboratoire Plasma et Conversion d' Energie), Université de Toulouse, UPS, INPT, 118 route de Narbonne, F-31062 Toulouse Cedex 9 (France); CNRS, LAPLACE, F-31062 Toulouse (France)

    2014-09-22

    Charge injection from a metal/insulator contact is a process promoting the formation of space charge in polymeric insulation largely used in thick layers in high voltage equipment. The internal charge perturbs the field distribution and can lead to catastrophic failure either through its electrostatic effects or through energetic processes initiated under charge recombination and/or hot electrons effects. Injection is still ill-described in polymeric insulation due to the complexity of the contact between the polymer chains and the electrodes. Barrier heights derived from the metal work function and the polymer electronic affinity do not provide a good description of the measurements [Taleb et al., IEEE Trans. Dielectr. Electr. Insul. 20, 311–320 (2013)]. Considering the difficulty to describe the contact properties and the need to prevent charge injection in polymers for high voltage applications, we developed an alternative approach by tailoring the interface properties by the silver nanoparticles (AgNPs)/plasma polymer stack, deposited on the polymer film. Due to their small size, the AgNPs, covered by a very thin film of plasma polymer, act as deep traps for the injected charges thereby stabilizing the interface from the point of view of charge injection. After a quick description of the method for elaborating the nanostructured layer near the contact, it is demonstrated how the AgNPs/plasma polymer stack effectively prevents, in a spectacular way, the formation of bulk space charge.

  15. Role of charge exchange neutrals in the deuterium retention for Tore Supra long discharges

    International Nuclear Information System (INIS)

    In Tore Supra long pulses, particle balance gives evidence that a constant fraction of the injected gas is retained in the wall all along the shot (typically 50%), showing no sign of wall saturation after more than 6 minutes of discharge. During the discharge, the retention rate first decreases (phase 1), then remains constant throughout the pulse (phase 2). Phase 1 could be interpreted as implantation of particles combined with a constant co-deposition rate, while phase 2 could correspond to co-deposition alone, once the implanted surfaces are saturated with deuterium. This paper presents a possible contribution of charge exchange neutrals to the implantation process, based on modelling results with the Eirene neutral transport code. A complex pattern of particle implantation is evidenced, with saturation time constants ranging from less than one to several hundreds seconds, compatible with the experimental behaviour during phase 1. (authors)

  16. Minimizing electrode edge in organic transistors with ultrathin reduced graphene oxide for improving charge injection efficiency.

    Science.gov (United States)

    Xu, Zeyang; Chen, Xiaosong; Zhang, Suna; Wu, Kunjie; Li, Hongwei; Meng, Yancheng; Li, Liqiang

    2016-05-11

    Electrode materials and geometry play a crucial role in the charge injection efficiency in organic transistors. Reduced graphene oxide (RGO) electrodes show good compatibility with an organic semiconductor from the standpoint of energy levels and ordered growth of the organic semiconductor, both of which are favourable for charge injection. However, the wide electrode edge (>10 nm) in commonly-used RGO electrodes is generally detrimental to charge injection. In this study, ultrathin (about 3 nm) RGO electrodes are fabricated via a covalency-based assembly strategy, which has advantages such as robustness against solvents, high conductivity, transparency, and easy scaling-up. More remarkably, the ultrathin electrode fabricated in this study has a narrow edge, which may facilitate the diffusion and assembly of organic semiconductors and thus form a uniform semiconductor film across the electrode/channel junction area. As a result, the minimized electrode edge may significantly improve the charge injection in organic transistors compared with thick electrodes. PMID:27062997

  17. Characteristics of solid-target charge-exchange analyzers for energetic ion diagnostics on tokamaks

    International Nuclear Information System (INIS)

    Compact electrostatic charge-exchange analyzers have been constructed for installation in areas of high magnetic fields and restricted access near tokamak fusion devices. The analyzers employed carbon stripping foils, and have been calibrated for proton energies between 1 and 70 keV. They have been successfully used to study charge-exchange losses in auxiliary-heated tokamak plasmas

  18. Charge injection E/D MESFET structures for high speed and low power applications

    OpenAIRE

    Masera, G; Piccinini, G.; Ruo Roch, M.; Zamboni, M

    1998-01-01

    In this paper new dynamic charge injection E/D logics are presented and compared with traditional dynamic ones such as TDFL (Two Phase Dynamic Fet Logic). The main drawbacks of TDFL will be analyzed together with the advantages offered with respect to the static DCFL based topologies; a tentative structure has been derived (MTDFL - Modified TDFL) to comply with the VLSI requirements; then the advantages of the charge injection principles applied to the design of new logic topologies are inspe...

  19. Charge injection from a surface depletion region—The Al 2O 3-silicon system

    Science.gov (United States)

    Kolk, J.; Heasell, E. L.

    1980-03-01

    Electron injection from a surface depletion region, over the surface barrier at an Al 2O 3-silicon interface is studied. The current passing over the barrier is measured by observing the rate of flat-band voltage shift as charge is trapped in the oxide. The data obtained is compared with the predictions of present models for charge injection. It is found that the so-called 'lucky-electron' model gives the most generally satisfactory agreement with the observations.

  20. Impact of charge carrier injection on single-chain photophysics of conjugated polymers

    CERN Document Server

    Hofmann, Felix J; Lupton, John M

    2016-01-01

    Charges in conjugated polymer materials have a strong impact on the photophysics and their interaction with the primary excited state species has to be taken into account in understanding device properties. Here, we employ single-molecule spectroscopy to unravel the influence of charges on several photoluminescence (PL) observables. The charges are injected either stochastically by a photochemical process, or deterministically in a hole-injection sandwich device configuration. We find that upon charge injection, besides a blue-shift of the PL emission and a shortening of the PL lifetime due to quenching and blocking of the lowest-energy chromophores, the non-classical photon arrival time distribution of the multichromophoric chain is modified towards a more classical distribution. Surprisingly, the fidelity of photon antibunching deteriorates upon charging, whereas one would actually expect the number of chromophores to be reduced. A qualitative model is presented to explain the observed PL changes. The resul...

  1. Nuclear isovector giant resonances excited by pion single charge exchange

    International Nuclear Information System (INIS)

    This thesis is an experimental study of isovector giant resonances in light nuclei excited by pion single charge exchange reactions. Giant dipole resonances in light nuclei are known to be highly structured. For the mass 9 and 13 giant dipole resonances, isospin considerations were found to be very important to understanding this structure. by comparing the excitation functions from cross section measurements of the (π+, π0) and (π, π0) inclusive reactions, the authors determined the dominant isospin structure of the analog IVGR's. The comparison was made after decomposing the cross section into resonant and non-resonant components. This decomposition is made in the framework of strong absorption and quasi-free scattering. Measurements in the region of the isovector giant dipole resonances (IVGDR) were made to cover the inclusive angular distributions out to the second minimum. Study of the giant resonance decay process provides further understanding of the resonances. This study was carried out by observing the (π+, π0p) coincident reactions involving the resonances of 9B and 13N excited from 9Be and 13C nuclei. These measurements determined the spectra of the decay protons. This method also permitted a decomposition of the giant resonances into their isospin components. The multipolarities of the resonances were revealed by the decay proton angular correlations which, for dipoles, are of the form 1 + A2P2(cos θ)

  2. Charge exchange recombination spectroscopy on the T-10 tokamak.

    Science.gov (United States)

    Klyuchnikov, L A; Krupin, V A; Nurgaliev, M R; Korobov, K V; Nemets, A R; Dnestrovskij, A Yu; Tugarinov, S N; Serov, S V; Naumenko, N N

    2016-05-01

    The charge exchange recombination spectroscopy (CXRS) diagnostics on the T-10 tokamak is described. The system is based on a diagnostic neutral beam and includes three high etendue spectrometers designed for the ITER edge CXRS system. A combined two-channel spectrometer is developed for simultaneous measurements of two beam-induced spectral lines using the same lines of sight. A basic element of the combined spectrometer is a transmitting holographic grating designed for the narrow spectral region 5291 ± 100 Å. The whole CXRS system provides simultaneous measurements of two CXRS impurity spectra and Hα beam line. Ion temperature measurements are routinely provided using the C(6+) CXRS spectral line 5291 Å. Simultaneous measurements of carbon densities and one more impurity (oxygen, helium, lithium etc.) are carried out. Two light collecting systems with 9 lines of sight in each system are used in the diagnostics. Spatial resolution is up to 2.5 cm and temporal resolution of 1 ms is defined by the diagnostic neutral beam diameter and pulse duration, respectively. Experimental results are shown to demonstrate a wide range of the CXRS diagnostic capabilities on T-10 for investigation of impurity transport processes in tokamak plasma. Developed diagnostics provides necessary experimental data for studying of plasma electric fields, heat and particle transport processes, and for investigation of geodesic acoustic modes. PMID:27250422

  3. Charge Exchange, from the Laboratory to Galaxy Clusters

    Science.gov (United States)

    Betancourt-Martinez, Gabriele; Beiersdorfer, Peter; Brown, Gregory; Hell, Natalie; Leutenegger, Maurice A.; Porter, Frederick S.; Reynolds, Christopher S.

    2016-04-01

    X-ray emission due to charge exchange (CX) between solar wind ions and neutrals in comets and planetary atmospheres is ubiquitous in the solar system, and is also a significant foreground in all observations from low-Earth orbit. It is also possible that CX is common astrophysically, in any environment where hot plasma and cold gas interact. A current challenge is that theoretical models of CX spectra do not always accurately describe observations, and require further experimental verification. This is especially important to focus on now, as the recent launch of Astro-H is providing us with the first high-resolution spectra of extended x-ray sources. In order to improve our understanding and modeling of CX spectra, we take advantage of the laboratory astrophysics program at the Lawrence Livermore National Laboratory and use an Electron Beam Ion Trap (EBIT) to perform CX experiments, using the EBIT Calorimeter Spectrometer. We present experimental benchmarks that can be used to develop a more comprehensive and accurate CX theory. On the observational side, we also investigate the possibility of CX occurring in the filaments around the central galaxy of the Perseus cluster, NGC 1275. We use Chandra ACIS data, combined with what we know about laboratory CX spectra, to investigate the possibility of CX being a significant contributor to the x-ray emission.

  4. The Solar Wind Charge-Exchange Production Factor for Hydrogen

    CERN Document Server

    Kuntz, K D; Collier, M R; Connor, H K; Cravens, T E; Koutroumpa, D; Porter, F S; Robertson, I P; Sibeck, D G; Snowden, S L; Thomas, N E; Wash, B M

    2015-01-01

    The production factor, or broad band averaged cross-section, for solar wind charge-exchange with hydrogen producing emission in the ROSAT 1/4 keV (R12) band is $3.8\\pm0.2\\times10^{-20}$ count degree$^{-2}$ cm$^4$. This value is derived from a comparison of the Long-Term (background) Enhancements in the ROSAT All-Sky Survey with magnetohysdrodynamic simulations of the magnetosheath. This value is 1.8 to 4.5 times higher than values derived from limited atomic data, suggesting that those values may be missing a large number of faint lines. This production factor is important for deriving the exact amount of 1/4 keV band flux that is due to the Local Hot Bubble, for planning future observations in the 1/4 keV band, and for evaluating proposals for remote sensing of the magnetosheath. The same method cannot be applied to the 3/4 keV band as that band, being composed primarily of the oxygen lines, is far more sensitive to the detailed abundances and ionization balance in the solar wind. We also show, incidentally,...

  5. The TFTR E Parallel B Spectrometer for Mass and Energy Resolved Multi-Ion Charge Exchange Diagnostics

    Energy Technology Data Exchange (ETDEWEB)

    A.L. Roquemore; S.S. Medley

    1998-01-01

    The Charge Exchange Neutral Analyzer diagnostic for the Tokamak Fusion Test Reactor was designed to measure the energy distributions of both the thermal ions and the supra thermal populations arising from neutral-beam injection and ion cyclotron radio-frequency heating. These measurements yield the plasma ion temperature, as well as several other plasma parameters necessary to provide an understanding of the plasma condition and the performance of the auxiliary heating methods. For this application, a novel charge-exchange spectrometer using a dee-shaped region of parallel electric and magnetic fields was developed at the Princeton Plasma Physics Laboratory. The design and performance of this spectrometer is described in detail, including the effects of exposure of the microchannel plate detector to magnetic fields, neutrons, and tritium.

  6. Raising the barrier for photoinduced DNA charge injection with a cyclohexyl artificial base pair.

    Science.gov (United States)

    Singh, Arunoday P N; Harris, Michelle A; Young, Ryan M; Miller, Stephen A; Wasielewski, Michael R; Lewis, Frederick D

    2015-01-01

    The effects of an artificial cyclohexyl base pair on the quantum yields of fluorescence and dynamics of charge separation and charge recombination have been investigated for several synthetic DNA hairpins. The hairpins possess stilbenedicarboxamide, perylenediimide, or naphthalenediimide linkers and base-paired stems. In the absence of the artificial base pair hole injection into both adenine and guanine purine bases is exergonic and irreversible, except in the case of stilbene with adenine for which it is slightly endergonic and reversible. Insertion of the artificial base pair renders hole injection endergonic or isoergonic except in the case of the powerful naphthalene acceptor for which it remains exergonic. Both hole injection and charge recombination are slower for the naphthalene acceptor in the presence of the artificial base pair than in its absence. The effect of an artificial base pair on charge separation and charge recombination in hairpins possessing stilbene and naphthalene acceptor linkers and a stilbenediether donor capping group has also been investigated. In the case of the stilbene acceptor-stilbene donor capped hairpins photoinduced charge separation across six base pairs is efficient in the absence of the artificial base pair but does not occur in its presence. In the case of the naphthalene acceptor-stilbene donor capped hairpins the artificial base pair slows but does not stop charge separation and charge recombination, leading to the formation of long-lived charge separated states. PMID:26442603

  7. Profiling of the injected charge drift current transients by cross-sectional scanning technique

    Science.gov (United States)

    Gaubas, E.; Ceponis, T.; Pavlov, J.; Baskevicius, A.

    2014-02-01

    The electric field distribution and charge drift currents in Si particle detectors are analyzed. Profiling of the injected charge drift current transients has been implemented by varying charge injection position within a cross-sectional boundary of the particle detector. The obtained profiles of the induction current density and duration of the injected charge drift pulses fit well the simulated current variations. Induction current transients have been interpreted by different stages of the bipolar and monopolar drift of the injected carriers. Profiles of the injected charge current transients registered in the non-irradiated and neutron irradiated Si diodes are compared. It has been shown that the mixed regime of the competing processes of drift, recombination, and diffusion appears in the measured current profiles on the irradiated samples. The impact of the avalanche effects can be ignored based on the investigations presented. It has been shown that even a simplified dynamic model enabled us to reproduce the main features of the profiled transients of induced charge drift current.

  8. Profiling of the injected charge drift current transients by cross-sectional scanning technique

    International Nuclear Information System (INIS)

    The electric field distribution and charge drift currents in Si particle detectors are analyzed. Profiling of the injected charge drift current transients has been implemented by varying charge injection position within a cross-sectional boundary of the particle detector. The obtained profiles of the induction current density and duration of the injected charge drift pulses fit well the simulated current variations. Induction current transients have been interpreted by different stages of the bipolar and monopolar drift of the injected carriers. Profiles of the injected charge current transients registered in the non-irradiated and neutron irradiated Si diodes are compared. It has been shown that the mixed regime of the competing processes of drift, recombination, and diffusion appears in the measured current profiles on the irradiated samples. The impact of the avalanche effects can be ignored based on the investigations presented. It has been shown that even a simplified dynamic model enabled us to reproduce the main features of the profiled transients of induced charge drift current

  9. Profiling of the injected charge drift current transients by cross-sectional scanning technique

    Energy Technology Data Exchange (ETDEWEB)

    Gaubas, E., E-mail: eugenijus.gaubas@ff.vu.lt; Ceponis, T.; Pavlov, J.; Baskevicius, A. [Institute of Applied Research, Vilnius University, Sauletekio av. 9-III, LT-10222 Vilnius (Lithuania)

    2014-02-07

    The electric field distribution and charge drift currents in Si particle detectors are analyzed. Profiling of the injected charge drift current transients has been implemented by varying charge injection position within a cross-sectional boundary of the particle detector. The obtained profiles of the induction current density and duration of the injected charge drift pulses fit well the simulated current variations. Induction current transients have been interpreted by different stages of the bipolar and monopolar drift of the injected carriers. Profiles of the injected charge current transients registered in the non-irradiated and neutron irradiated Si diodes are compared. It has been shown that the mixed regime of the competing processes of drift, recombination, and diffusion appears in the measured current profiles on the irradiated samples. The impact of the avalanche effects can be ignored based on the investigations presented. It has been shown that even a simplified dynamic model enabled us to reproduce the main features of the profiled transients of induced charge drift current.

  10. Charge-exchange and charge-conserving reactions on Mg, Ar, Zr, and Sn isotopes

    International Nuclear Information System (INIS)

    We investigate charge-exchange reactions (CEXRs) and charge-conserving reactions (CCORs) on Mg, Ar, Zr, and Sn isotopes by comparing our theoretical results to relevant experimental data on stable nuclei. As for CEXRs, first, we discuss nuclear beta decay because it may give more convincing input data on the network calculations for successive capture reactions by protons and neutrons. Second, we address the importance of the Gamow Teller (GT) states that are low-lying excited states well known in the conventional nuclear physics while high-lying excited states still remain to be studied. The third topic, which is viable through the CCORs, is the symmetry energy associated with the equation of state of nuclear matter. By using the CCORs, we can study the isoscalar giant dipole resonance (ISGDR) and the pigmy dipole resonance (PDR). We discuss theoretical results regarding these CEXRs and CCORs on 26Mg, 40Ar, 90,92Zr, and 112∼124Sn and compare them with available experimental data. Our calculations are carried out by using the proton-neutron quasi-particle random phase approximation (pnQRPA), the QRPA, the deformed QRPA (DQRPA), the shell model and a hybrid model. Our results are shown to agree with the data available. These nuclear reactions considered in this report will complement capture reactions by protons and neutrons which are of vital importance for understanding the element abundances in the cosmos.

  11. Neutrino and antineutrino charge-exchange reactions on 12C

    International Nuclear Information System (INIS)

    We extend the formalism of weak interaction processes, obtaining new expressions for the transition rates, which greatly facilitate numerical calculations, for both neutrino-nucleus reactions and muon capture. Explicit violation of the conserved vector current hypothesis by the Coulomb field, as well as development of a sum-rule approach for inclusive cross sections, has been worked out. We have done a thorough study of exclusive (ground-state) properties of 12B and 12N within the projected quasiparticle random phase approximation (PQRPA). Good agreement with experimental data achieved in this way put into evidence the limitations of the standard RPA and QRPA models, which come from the inability of the RPA to open the p3/2 shell and from the nonconservation of the number of particles in the QRPA. The inclusive neutrino/antineutrino (ν/ν-tilde) reactions 12C(ν,e-)12N and 12C(ν-tilde,e+)12B are calculated within both the PQRPA and the relativistic QRPA. It is found that (i) the magnitudes of the resulting cross sections are close to the sum-rule limit at low energy, but significantly smaller than this limit at high energies, for both ν and ν-tilde; (ii) they increase steadily when the size of the configuration space is augmented, particularly for ν/ν-tilde energies >200 MeV; and (iii) they converge for sufficiently large configuration space and final-state spin. The quasi-elastic 12C(ν,μ-)12N cross section recently measured in the MiniBooNE experiment is briefly discussed. We study the decomposition of the inclusive cross section based on the degree of forbiddenness of different multipoles. A few words are dedicated to the ν/ν-tilde-12C charge-exchange reactions related to astrophysical applications.

  12. Charge Exchange Collisions between Ultracold Fermionic Lithium Atoms and Calcium Ions

    CERN Document Server

    Haze, Shinsuke; Saito, Ryoichi; Mukaiyama, Takashi

    2014-01-01

    An observation of charge exchange collisions between ultracold fermionic 6Li atoms and 40Ca+ ions is reported. The reaction product of the charge exchange collision is dentified via mass spectrometry where the motion of the ions is excited parametrically. We measure the cross section of the charge exchange collisions between the 6Li atoms in the ground state and the 40Ca+ ions in the ground and metastable excited states. Investigation of the inelastic collision characteristics in the atom-ion mixture is an important step toward ultracold chemistry based on ultracold atoms and ions.

  13. Carbon charge exchange analysis in the ITER-like wall environment

    International Nuclear Information System (INIS)

    Charge exchange spectroscopy has long been a key diagnostic tool for fusion plasmas and is well developed in devices with Carbon Plasma-Facing Components. Operation with the ITER-like wall at JET has resulted in changes to the spectrum in the region of the Carbon charge exchange line at 529.06 nm and demonstrates the need to revise the core charge exchange analysis for this line. An investigation has been made of this spectral region in different plasma conditions and the revised description of the spectral lines to be included in the analysis is presented

  14. Charge exchange cross section database for proton collisions with hydrocarbon molecules

    International Nuclear Information System (INIS)

    The available experimental and theoretical cross section data on charge exchange processes in collisions of protons with hydrocarbon molecules have been collected and critically assessed. Using well established scaling relationships for the charge exchange cross sections at low and high collision energies, as well as the known rate coefficients for these reactions in the thermal energy region, a complete cross sections database is constructed for proton-CxHy charge exchange reactions from thermal energies up to several hundreds keV for all CxHy molecules with x=1,2,3 and 1≤y≤2x+2. (author)

  15. Injecting Drug Users Retention in Needle-Exchange Program and its Determinants in Iran Prisons

    OpenAIRE

    Shahbazi, Mohammad; Farnia, Marzieh; MORADI, Ghobad; Karamati, Mohammadreza; Paknazar, Fatemeh; Mirmohammad'khani, Majid

    2015-01-01

    Background: Participation and to stay in a health program depends on many factors. One of these programs is Needle Exchange Program (NEP) in prisons. Objectives: The current study aimed to evaluate the retention of injecting drug prisoners and find the related factors in Iran. Patients and Methods: This cohort study analyzed data about injecting drug male prisoners who were participated in NEP in three Iranian prisons. Data was collected from October 2009 to June 2010. A proper approach of su...

  16. Active neutral particle diagnostics on LHD by locally enhanced charge exchange on an impurity pellet ablation cloud

    International Nuclear Information System (INIS)

    Production, confinement and thermalization of high-energy particles are the fundamental issues in fusion plasma ion kinetics. The ion distribution function and its evolution under the ion cyclotron heating and neutral beam injection are studied by energy resolved charge exchange neutral flux measurements. For helical systems, such as LHD, local diagnostics are required due to the complex 3D magnetic field. In passive methods one needs to analyze the integral relation between the plasma ion distribution function and the observed neutral flux, which is a superposition along the diagnostic sightline, taking into account the charge exchange target density profile. In active measurements either a diagnostic neutral beam or a solid pellet injection are used to enhance the charge exchange locally. An impurity pellet ablation cloud rcloud plasma provides a localized charge exchange target scanning the plasma radially. Pellet-induced neutral fluxes were previously measured on LHD with a natural diamond detector. However, obtaining the energy spectra from these data in the main energy range of interest (101-102 keV in the present experiments) is complicated due to the high operating speed, i.e. the spatial resolution requirement. A new diagnostic based on a compact neutral particle analyser (CNPA) has been installed on LHD for measurements in the H0 energy range 1 - 170 keV. CNPA employs a thin 50 A diamond-like carbon stripping film instead of a traditional gas stripping cell, a high-field-strength permanent analysing magnet and an array of 40 channel electron multipliers (CEMs) for particle detection. CEMs can be used in both counting and current modes to be able to process high neutral particle fluxes from the charge exchange on the dense pellet cloud. Thus, the system is suitable for both passive measurements and the active probing with a diagnostic pellet. Pneumatically accelerated polystyrene (-C8H8-)n balls are injected transversally; typical Dpel = 500-900 μm, vpel

  17. Charge injection in an LED with a hybrid composite as the emissive layer

    International Nuclear Information System (INIS)

    Understanding and controlling charge transport are crucial to achieve optimized organic devices, including light emitting diodes. In this study, we investigate the charge injection in devices made with a hybrid composite (HC) containing Zn2SiO4:Mn (ZSP:Mn) in a polymeric blend consisting of poly(o-methoxyaniline) (POMA) and poly(vinylidene co-trifluorethylene) P(VDFTrFE), with the architecture ITO/HC/metallic electrode (ME). Charge injection was found to depend mainly on the POMA semiconducting phase. For ITO/HC/Au, an Ohmic junction was observed because the work function of ITO is close to that of Au, which also matches the energy levels of HC. Holes are injected through the HC/Au junction, as the highest occupied molecular orbital (HOMO) level of POMA matches the Fermi level of Au. The impedance spectroscopy data for the ITO/HC/ME devices were analyzed with a theoretical model where charge injection was assumed to occur via hopping with a distribution of potential energy barriers. The average hopping distance was estimated as 5.5 A and only the device with the Al electrode had the current limited by the interface mechanism (charge injection). For ITO/HC/Cu and ITO/HC/Au devices the limiting factor for the charge transport was the bulk resistance of the samples, in spite of the existence of a small interface energy barrier. The disorder parameter was 0.18 and 0.19 for the HC/Cu and HC/Al interfaces, respectively, which arises from the disordered nature of the hybrid material. The combination of the Cole-Cole model and the Miller-Abrahams function are a good approach to describe charge a.c. injection processes in disordered materials.

  18. Design and operation of the pellet charge exchange diagnostic for measurement of energetic confined alphas and tritons on TFTR

    International Nuclear Information System (INIS)

    Radially-resolved energy and density distributions of the energetic confined alpha particles in D-T experiments on TFTR are being measured by active neutral particle analysis using low-Z impurity pellet injection. When injected into a high temperature plasma, an impurity pellet (e.g. Lithium or Boron) rapidly ablates forming an elongated cloud which is aligned with the magnetic field and moves with the pellet. This ablation cloud provides a dense target with which the alpha particles produced in D-T fusion reactions can charge exchange. A small fraction of the alpha particles incident on the pellet ablation cloud will be converted to helium neutrals whose energy is essentially unchanged by the charge transfer process. By measuring the resultant helium neutrals escaping from the plasma using a mass and energy resolving charge exchange analyzer, this technique offers a direct measurement of the energy distribution of the incident high-energy alpha particles. Other energetic ion species can be detected as well, such as tritons generated in D-D plasmas and H or He3 RF-driven minority ion tails. The diagnostic technique and its application on TFTR are described in detail

  19. A Method to Overcome Space Charge at Injection

    Energy Technology Data Exchange (ETDEWEB)

    Ya. Derbenev

    2005-09-29

    The transverse space charge forces in a high current, low energy beam can be reduced by mean of a large increase of the beam's transverse sizes while maintaining the beam area in the 4D phase space. This can be achieved by transforming the beam area in phase space of each of two normal 2D transverse (either plane or circular) modes from a spot shape into a narrow ring of a large amplitude, but homogeneous in phase. Such a transformation results from the beam evolution in the island of a dipole resonance when the amplitude width of the island shrinks adiabatically. After stacking (by using stripping foils or cooling) the beam in such a state and accelerating to energies sufficiently high that the space charge becomes insignificant, the beam then can be returned back to a normal spot shape by applying the reverse transformation. An arrangement that can provide such beam gymnastics along a transport line after a linac and before a booster and/or in a ring with circulating beam will be described and numerical estimates will be presented. Other potential applications of the method will be briefly discussed.

  20. A Method to Overcome Space Charge at Injection

    International Nuclear Information System (INIS)

    The transverse space charge forces in a high current, low energy beam can be reduced by mean of a large increase of the beam's transverse sizes while maintaining the beam area in the 4D phase space. This can be achieved by transforming the beam area in phase space of each of two normal 2D transverse (either plane or circular) modes from a spot shape into a narrow ring of a large amplitude, but homogeneous in phase. Such a transformation results from the beam evolution in the island of a dipole resonance when the amplitude width of the island shrinks adiabatically. After stacking (by using stripping foils or cooling) the beam in such a state and accelerating to energies sufficiently high that the space charge becomes insignificant, the beam then can be returned back to a normal spot shape by applying the reverse transformation. An arrangement that can provide such beam gymnastics along a transport line after a linac and before a booster and/or in a ring with circulating beam will be described and numerical estimates will be presented. Other potential applications of the method will be briefly discussed

  1. A purely classical description of crossings of energy levels and spectroscopic signatures of charge exchange

    International Nuclear Information System (INIS)

    Charge exchange and crossings of corresponding energy levels that enhance charge exchange are strongly connected with problems of energy loss and diagnostics in high-temperature plasmas. Charge exchange has also been proposed as one of the most effective mechanisms for population inversion in the soft x-ray and VUV ranges. One area of the most fundamental theoretical importance in the study of charge exchange is the problem of electron terms in the field of two stationary Coulomb centres (TCC) of charges Z and Z' separated by a distance R. This involves fascinating atomic physics: the terms can have crossings and quasicrossings. These rich features of the TCC problem are also manifest in other areas of physics such as plasma spectroscopy: a quasicrossing of the TCC terms, by enhancing charge exchange, can result in an unusual structure (a dip) in the spectral line profile emitted by a Z-ion from a plasma consisting of both Z- and Z'-ions, as has been shown theoretically and experimentally. The paradigm is that these sophisticated features of the TCC problem and their flourishing applications are inherently quantum phenomena. In this paper we disprove this paradigm. We present a purely classical description of both the crossings of energy levels in the TCC problem and the dips in the corresponding spectral line profiles caused by the crossing (via enhanced charge exchange). Our classical description is based on first principles and does not use any model assumptions. (author)

  2. Charge injection in thin dielectric layers by atomic force microscopy: influence of geometry and material work function of the AFM tip on the injection process

    Science.gov (United States)

    Villeneuve-Faure, C.; Makasheva, K.; Boudou, L.; Teyssedre, G.

    2016-06-01

    Charge injection and retention in thin dielectric layers remain critical issues for the reliability of many electronic devices because of their association with a large number of failure mechanisms. To overcome this drawback, a deep understanding of the mechanisms leading to charge injection close to the injection area is needed. Even though the charge injection is extensively studied and reported in the literature to characterize the charge storage capability of dielectric materials, questions about charge injection mechanisms when using atomic force microscopy (AFM) remain open. In this paper, a thorough study of charge injection by using AFM in thin plasma-processed amorphous silicon oxynitride layers with properties close to that of thermal silica layers is presented. The study considers the impact of applied voltage polarity, work function of the AFM tip coating and tip curvature radius. A simple theoretical model was developed and used to analyze the obtained experimental results. The electric field distribution is computed as a function of tip geometry. The obtained experimental results highlight that after injection in the dielectric layer the charge lateral spreading is mainly controlled by the radial electric field component independently of the carrier polarity. The injected charge density is influenced by the nature of electrode metal coating (work function) and its geometry (tip curvature radius). The electron injection is mainly ruled by the Schottky injection barrier through the field electron emission mechanism enhanced by thermionic electron emission. The hole injection mechanism seems to differ from the electron one depending on the work function of the metal coating. Based on the performed analysis, it is suggested that for hole injection by AFM, pinning of the metal Fermi level with the metal-induced gap states in the studied silicon oxynitride layers starts playing a role in the injection mechanisms.

  3. Plastification en injection des polymères fonctionnels et chargés

    OpenAIRE

    Pham, Thuy Linh

    2013-01-01

    The main objective of the thesis is modelling and visualization of the phenomena of polymer plastication in the injection-moulding process. In injection moulding or in extrusion, plastication is the step during which polymer pellets are melted by the means of mechanical dissipation provided by a rotating screw and by thermal conduction coming from a heated metallic barrel. This step is crucial for melt thermal homogeneity, charge dispersion and fibre length preservation. Although there have b...

  4. Dispersion Matching of a Space Charge dominated Beam at Injection into the CERN PS Booster

    CERN Document Server

    Hanke, Klaus; Scrivens, Richard

    2005-01-01

    In order to match the dispersion at injection into the CERN PS Booster, the optics of the injection line was simulated using two different codes (MAD and TRACE). The simulations were benchmarked versus experimental results. The model of the line was then used to re-match the dispersion. Experimental results are presented for different optics of the line. Measurements with varying beam current show the independence of the measured quantity of space-charge effects.

  5. Spectrophotometric flow injection catalytic determination of molybdenum in plant digest using ion exchange resin

    International Nuclear Information System (INIS)

    A spectrophotometric flow injection analytical method based on the catalytic action of molybdenum on the oxidation of iodide by hydrogen peroxide in acidic medium is proposed for the molybdenum determination in plant digests. A cation exchange resin column is incorporated into a flow injection system for removal of interferents. The following system variables were investigated and optimized: reagent concentrations, sample injection volume, mixing and reaction coil lengths, temperature, sampling time, pumping rate and concentration of eluting agents. The effects of interfering species and of the acidity of samples on the molybdenum retention by the ion exchange resin column were investigated. The proposed method is characterized by good precision (r.s.d. (2.0%), a sampling rate of about 40 samples per hour, and permits the determination of molybdenum in plant digests in the range 1.0 to 40.0 μg/l. The results compare well with those obtained by graphite furnace atomic absorption spectrometry. (author)

  6. Space charge effects in axial injection line for U-400 cyclotron

    International Nuclear Information System (INIS)

    The space charge influence on the beam dynamics in transport line is studied by the method of the distribution moments. Fifteen equations describing dependence of the first and second order moments (average transverse beam sizes and velocities, cross terms) on longitudinal coordinate are solved numerically. For particular U-400 cyclotron injection line the value of current which produces significant effect on beam dynamics is defined. It is shown that space charge effects can be compensated by proper readjusting of the solenoid strengths

  7. Impact of charge carrier injection on single-chain photophysics of conjugated polymers

    Science.gov (United States)

    Hofmann, Felix J.; Vogelsang, Jan; Lupton, John M.

    2016-06-01

    Charges in conjugated polymer materials have a strong impact on the photophysics and their interaction with the primary excited state species has to be taken into account in understanding device properties. Here, we employ single-molecule spectroscopy to unravel the influence of charges on several photoluminescence (PL) observables. The charges are injected either stochastically by a photochemical process or deterministically in a hole-injection sandwich device configuration. We find that upon charge injection, besides a blue-shift of the PL emission and a shortening of the PL lifetime due to quenching and blocking of the lowest-energy chromophores, the non-classical photon arrival time distribution of the multichromophoric chain is modified towards a more classical distribution. Surprisingly, the fidelity of photon antibunching deteriorates upon charging, whereas one would actually expect the opposite: the number of chromophores to be reduced. A qualitative model is presented to explain the observed PL changes. The results are of interest to developing a microscopic understanding of the intrinsic charge-exciton quenching interaction in devices.

  8. Significance of anion exchange in pentachlorophenol sorption by variable-charge soils.

    Science.gov (United States)

    Hyun, Seunghun; Lee, Linda S; Rao, P Suresh C

    2003-01-01

    Sorption data and subsequent predictive models for evaluating acidic pesticide behavior on variable-charge soils are needed to improve pesticide management and environmental stewardship. Previous work demonstrated that sorption of pentachlorophenol (PCP), a model organic acid, was adequately modeled by accounting for pH-and pKa-dependent chemical speciation and using two organic carbon-normalized sorption coefficients; one each for the neutral and anionic species. Such models do not account for organic anion interaction to positively charged surface sites, which can be significant for variable-charge minerals present in weathered soils typical of tropical and subtropical regions. The role of anion exchange in sorption of ionizable chemicals by variable-charge soils was assessed by measuring sorption of PCP by several variable-charge soils from aqueous solutions of CaCl2, CaSO4, Ca(H2PO4)2 as a function of pH. Differences in sorption from phosphate and chloride electrolyte solutions were attributed to pentachlorophenolate interactions with anion exchange sites. Suppression of PCP sorption by phosphate ranged from negligible in a soil with essentially no positively charge sites, as measured by negligible anion exchange capacity, to as much as 69% for variable-charge soils. Pentachlorophenolate exchange correlated well with the ratio of pH-dependent anion exchange capacity to net surface charge. Sorption reversibility of PCP by both CaCl2 and Ca(H2PO4)2 solutions was also demonstrated. Results for PCP clearly demonstrate that sorption to anion exchange sites in variable-charge soils should be considered in assessing pesticide mobility and that phosphate fertilizer application may increase the mobility of acidic pesticides. PMID:12809297

  9. Maximal charge injection of consecutive electron pulses with uniform temporal pulse separation

    International Nuclear Information System (INIS)

    A charge sheet model is proposed for the study of the space-charge limited density of consecutive electron pulses injected to in a diode with uniform temporal pulse separation. Based on the model, an analytical formula is derived for expressing the dependency of the charge density limit on the gap spacing, gap voltage, and pulse separation. The theoretical results are verified by numerical solutions up to electron energy of a few MeV, including relativistic effects. The model can be applied to the design of multiple-pulse electron beams for time resolved electron microscopy and free electron lasers

  10. Charge Injection and Transport in Metal/Polymer Chains/Metal Sandwich Structure

    Institute of Scientific and Technical Information of China (English)

    LI Hai-Hong; LI Dong-Mei; LI Yuan; GAO Kun; LIU De-Sheng; XIE Shi-Jie

    2008-01-01

    @@ Using the tight-binding Su-Schrieffer-Heeger model and a nonadiabatic dynamic evolution method, we study the dynamic processes of the charge injection and transport in a metal/two coupled conjugated polymer chains/metal structure. It is found that the charge interchain transport is determined by the strength of the electric field and the magnitude of the voltage bias applied on the metal electrode. The stronger electric field and the larger voltage bias are both in favour of the charge interchain transport.

  11. N(+)-N long-range interaction energies and resonance charge exchange

    Science.gov (United States)

    Stallcop, J. R.; Partridge, H.

    1985-01-01

    The aerothermodynamic studies of proposed space missions require atmospheric charge-transfer data. N2(+) eigenstate energies are calculated with use of the complete-active-space self-consistent-field method with an extended Gaussian basis set. The N(+)-N charge-exchange cross section, determined from these energies, agrees with merged-beam measurements. This contradicts the previous theoretical conclusion. A simple physical description of the long-range interaction is presented and should expedite future charge-transfer studies.

  12. Charge-exchange and fusion reaction measurements during compression experiments with neutral beam heating in the Tokamak Fusion Test Reactor

    International Nuclear Information System (INIS)

    Adiabatic toroidal compression experiments were performed in conjunction with high power neutral beam injection in the Tokamak Fusion Test Reactor (TFTR). Acceleration of beam ions to energies nearly twice the injection energy was measured with a charge-exchange neutral particle analyzer. Measurements were also made of 2.5 MeV neutrons and 15 MeV protons produced in fusion reactions between the deuterium beam ions and the thermal deuterium and 3He ions, respectively. When the plasma was compressed, the d(d,n)3He fusion reaction rate increased a factor of five, and the 3He(d,p)4He rate by a factor of twenty. These data were simulated with a bounce-averaged Fokker-Planck program, which assumed conservation of angular momentum and magnetic moment during compression. The results indicate that the beam ion acceleration was consistent with adiabatic scaling

  13. X-ray Signature of Charge Exchange in the Spectra of L-shell Iron Ions

    Energy Technology Data Exchange (ETDEWEB)

    Beiersdorfer, P; Schweikhard, L; Liebisch, P; Brown, G V

    2007-01-05

    The X-ray signature of charge exchange between highly charged L-shell iron ions and neutral gas atoms was studied in the laboratory in order to assess its diagnostic utility. Significant differences with spectra formed by electron-impact excitation were observed. In particular, a strong enhancement was found of the emission corresponding to n {le} 4 {yields} n = 2 transitions relative to the n = 3 {yields} n = 2 emission. This enhancement was detectable even with relatively low-resolution X-ray instrumentation (E/{Delta}E {approx} 10) and may enable future identification of charge exchange as a line-formation mechanism in astrophysical spectra.

  14. Laboratory simulation of charge exchange-produced X-ray emission from comets.

    Science.gov (United States)

    Beiersdorfer, P; Boyce, K R; Brown, G V; Chen, H; Kahn, S M; Kelley, R L; May, M; Olson, R E; Porter, F S; Stahle, C K; Tillotson, W A

    2003-06-01

    In laboratory experiments using the engineering spare microcalorimeter detector from the ASTRO-E satellite mission, we recorded the x-ray emission of highly charged ions of carbon, nitrogen, and oxygen, which simulates charge exchange reactions between heavy ions in the solar wind and neutral gases in cometary comae. The spectra are complex and do not readily match predictions. We developed a charge exchange emission model that successfully reproduces the soft x-ray spectrum of comet Linear C/1999 S4, observed with the Chandra X-ray Observatory. PMID:12791989

  15. The Contribution of Reggeon in Charge Exchange Processes

    CERN Document Server

    Yu Feng Zhou; Lian Shou Liu; Yufeng, Zhou; Hongan, Peng; Lianshou, Liu

    1998-01-01

    We discuss in this paper The experimental results on maximum psedo-rapidity Collaboration at HERA. We calculate the contributions of \\regg ($\\rho$-Reggeon associated with $\\rho$ meson) from regge phenomenology and $\\pi^{+}$-exchange from pion cloud model. The results show that neither the \\regg-exchange nor the pion cloud model alone can explain the experimental data well, but after considering both these two processes together, by using Monte Carlo simulation, a good agreement between theoretical results and experimental data is found. This means that in discussing the large rapidity gap phenomena in deep inelastic scattering, both of the two processes play substantial role.

  16. To what extent can charge localization influence electron injection efficiency at graphene-porphyrin interfaces?

    KAUST Repository

    Mohammed, Omar F.

    2015-04-28

    Controlling the electron transfer process at donor- acceptor interfaces is a research direction that has not yet seen much progress. Here, with careful control of the charge localization on the porphyrin macrocycle using β -Cyclodextrin as an external cage, we are able to improve the electron injection efficiency from cationic porphyrin to graphene carboxylate by 120% . The detailed reaction mechanism is also discussed.

  17. Charge injection and discharging of Si nanocrystals and arrays by atomic force microscopy

    Science.gov (United States)

    Boer, E.; Ostraat, M.; Brongersma, M. L.; Flagan, R. C.; Atwater, H. A.

    2000-01-01

    Charge injection and storage in dense arrays of silicon nanocrystals in SiO(sub 2) is a critical aspect of the performance of potential nanocrystal flash memory structures. The ultimate goal for this class of devices is few-or single- electron storage in a small number of nanocrystal elements.

  18. Influence of injected charge carriers on photocurrents in polymer solar cells

    NARCIS (Netherlands)

    Wehenkel, Dominique J.; Koster, L. Jan Anton; Wienk, Martijn M.; Janssen, Rene A. J.

    2012-01-01

    We determine and analyze the photocurrent Jph in polymer solar cells under conditions where, no, one, or two different charge carriers can be injected by choosing appropriate electrodes and compare the experimental results to simulations based on a drift-diffusion device model that accounts for phot

  19. In vivo charge injection limits increased after 'unsafe' stimulation

    DEFF Research Database (Denmark)

    Meijs, Suzan; Sørensen, Søren; Rechendorff, Kristian; Rijkhoff, Nico

    The effect of unsafe stimulation on charge injection limits (Qinj) and pulsing capacitance (Cpulse) was investigated. Four stimulation protocols were applied: 20 mA – 200 and 400 Hz, 50 mA – 200 and 400 Hz. Increasing Qinj and Cpulse were observed for all stimulation protocols. Corrosion was not ...

  20. Pion induced double-charge exchange above the resonance

    International Nuclear Information System (INIS)

    The zero degree excitation function for (π+, π-) is calculated for pion energies of 300 to 1400 MeV assuming a sequential mechanism. The cross section around 1225 MeV is 104 smaller than at 800 MeV. Experiments at this energy should be ideal for searches for effects due to exchange currents, and other non-conventional mechanisms. 15 refs

  1. Improved charge injection of pentacene transistors by immobilizing DNA on gold source-drain electrodes

    Science.gov (United States)

    Gui, Haiyang; Wei, Bin; Zhang, Jianhua; Wang, Jun

    2014-06-01

    We successfully optimized the charge injection of pentacene-based organic thin-film transistors with bottom contact by immobilizing deoxyribonucleic acid (DNA) on gold electrodes. The single-stranded DNA having mercapto group (-SH) was used as the modified layer by molecular self-assembly onto the surface of gold electrodes. The threshold voltage is -10 V, and the field-effect mobility reaches 0.34 cm2/V s, which is comparable with that of typical top-contact devices. Mechanism of performance improvement is due to the high carrier density in contact region attracted by the phosphate group on the DNA backbone increasing the tunneling probability for improved charge injection. Furthermore, the introduction of modified layer significantly enhanced the grain size of pentacene that is beneficial for charge transport, which also is responsible for the improved device performances.

  2. Experiments on air bubbles injection into a vertical shell and coiled tube heat exchanger; exergy and NTU analysis

    International Nuclear Information System (INIS)

    Highlights: • Air bubbles injection was employed to enhance the performance of a vertical shell and coiled tube heat exchanger. • Air bubbles were injected into the shell side of heat exchanger via a new method at different conditions. • NTU enhancement and Exergy loss due to air bubbles injection were studied. • Present type of air bubble injection significantly increased the amount NTU and performance of heat exchanger. - Abstract: In this paper, attempts are made to increase the number of thermal units (NTU) and performance in a vertical shell and coiled tube heat exchanger via air bubble injection into the shell side of heat exchanger. Besides, exergy loss due to air bubble injection is investigated. Indeed, air bubble injection and bubbles mobility (because of buoyancy force) can intensify the NTU and exergy loss by mixing the thermal boundary layer and increasing the turbulence level of the fluid flow. Air bubbles were injected inside the heat exchanger via a special method and at new different conditions in this paper. It was demonstrated that the amount of NTU and effectiveness can be significantly improved due to air bubbles injection

  3. The Impact of Legalizing Syringe Exchange Programs on Arrests Among Injection Drug Users in California

    OpenAIRE

    Martinez, Alexis N.; Bluthenthal, Ricky N.; Lorvick, Jennifer; Anderson, Rachel; Flynn, Neil; Kral, Alex H.

    2007-01-01

    Legislation passed in 2000 allowed syringe exchange programs (SEPs) in California to operate legally if local jurisdictions declare a local HIV public health emergency. Nonetheless, even in locales where SEPs are legal, the possession of drug paraphernalia, including syringes, remained illegal. The objective of this paper is to examine the association between the legal status of SEPs and individual arrest or citation for drug paraphernalia among injection drug users (IDUs) in California from ...

  4. Master equation approach to charge injection and transport in organic insulators.

    Science.gov (United States)

    Freire, José A; Voss, Grasiela

    2005-03-22

    We develop a master equation model of a disordered organic insulator sandwiched between metallic electrodes by treating as rate processes both the injection and the internal transport. We show how the master equation model allows for the inclusion of crucial correlation effects in the charge transport, particularly of the Pauli exclusion principle and of space-charge effects, besides, being dependent on just the microscopic form of the transfer rate between the localized electronic states, it allows for the investigation of different microscopic scenarios in the organic, such as polaronic hopping, correlated energy levels, interaction with image charge, etc. The model allows for a separate analysis of the injection and the recombination currents. We find that the disorder, besides increasing the injection current, eliminates the possibility of observation of a Fowler-Nordheim injection current at zero temperature, and that it does not alter the Schottky barrier size of the zero-field thermionic injection current from the value based on the energy difference between the electrode Fermi level and the highest occupied molecular orbital/lowest unoccupied molecular orbital levels in the organic, but it makes the Arrhenius temperature dependence appear at larger temperatures. We investigate how the I(V) characteristics of a device is affected by the presence of correlations in the site energy distribution and by the form of the internal hopping rate, specifically the Miller-Abrahams rate and the Marcus or small-polaron rate. We show that the disorder does not modify significantly the ebeta square root E field dependence of the net current due to the Schottky barrier lowering caused by the attraction between the charge and its image in the electrode. PMID:15836407

  5. X-Ray Emission Cross Sections following Charge Exchange by Multiply-Charged Ions of Astrophysical Interest

    Energy Technology Data Exchange (ETDEWEB)

    Otranto, S; Olson, R E; Beiersdorfer, P

    2007-03-12

    The CTMC method is used to calculate emission cross sections following charge exchange processes involving highly charged ions of astrophysical interest and typical cometary targets. Comparison is made to experimental data obtained on the EBIT-I machine at Lawrence Livermore National Laboratory LLNL for O{sup 8+} projectiles impinging on different targets at a collision energy of 10 eV/amu. The theoretical cross sections are used together with ion abundances measured by the Advanced Composition Explorer to reproduce cometary spectra. Discrepancies due to different estimated delays of solar wind events between the comet and the Earth-orbiting satellite are discussed.

  6. Integrated analysis and consistency measurement of bremsstrahlung and charge exchange spectroscopy data for the determination of the ion effective charge

    International Nuclear Information System (INIS)

    In the context of Bayesian probability theory, we discuss a model for estimating the plasma ion effective charge Zeff, integrating data from both bremsstrahlung spectroscopy and individual impurity concentrations obtained via charge exchange spectroscopy (CXS). The validity of the model, taking into account statistical as well as systematic uncertainties, is shown via the deviance information criterion. The consistency of the continuum and CXS data regarding Zeff is improved, as measured by the symmetrized Kullback-Leibler divergence and the geodesic distance between the respective Zeff marginal posterior densities.

  7. Removal of charged micropollutants from water by ion-exchange polymers -- effects of competing electrolytes.

    Science.gov (United States)

    Bäuerlein, Patrick S; Ter Laak, Thomas L; Hofman-Caris, Roberta C H M; de Voogt, Pim; Droge, Steven T J

    2012-10-15

    A wide variety of environmental compounds of concern, e.g. pharmaceuticals or illicit drugs, are acids or bases that may predominantly be present as charged species in drinking water sources. These charged micropollutants may prove difficult to remove by currently used water treatment steps (e.g. UV/H(2)O(2), activated carbon (AC) or membranes). We studied the sorption affinity of some ionic organic compounds to both AC and different charged polymeric materials. Ion-exchange polymers may be effective as additional extraction phases in water treatment, because sorption of all charged compounds to oppositely charged polymers was stronger than to AC, especially for the double-charged cation metformin. Tested below 1% of the polymer ion-exchange capacity, the sorption affinity of charged micropollutants is nonlinear and depends on the composition of the aqueous medium. Whereas oppositely charged electrolytes do not impact sorption of organic ions, equally charged electrolytes do influence sorption indicating ion-exchange (IE) to be the main sorption mechanism. For the tested polymers, a tenfold increased salt concentration lowered the IE-sorption affinity by a factor two. Different electrolytes affect IE with organic ions in a similar way as inorganic ions on IE-resins, and no clear differences in this trend were observed between the sulphonated and the carboxylated cation-exchanger. Sorption of organic cations is five fold less in Ca(2+) solutions compared to similar concentrations of Na(+), while that of anionic compounds is three fold weaker in SO(4)(2-) solutions compared to equal concentrations of Cl(-). PMID:22818952

  8. Secure key-exchange protocol with an absence of injective functions

    International Nuclear Information System (INIS)

    The security of neural cryptography is investigated. A key-exchange protocol over a public channel is studied where the parties exchanging secret messages use multilayer neural networks which are trained by their mutual output bits and synchronize to a time dependent secret key. The weights of the networks have integer values between ±L. Recently an algorithm for an eavesdropper which could break the key was introduced by [A. Shamir, A. Mityagin, and A. Klimov, Ramp Session (Eurocrypt, Amsterdam, 2002)]. We show that the synchronization time increases with L2 while the probability to find a successful attacker decreases exponentially with L. Hence for large L we find a secure key-exchange protocol which depends neither on number theory nor on injective trapdoor functions used in conventional cryptography

  9. Secure key-exchange protocol with an absence of injective functions.

    Science.gov (United States)

    Mislovaty, R; Perchenok, Y; Kanter, I; Kinzel, W

    2002-12-01

    The security of neural cryptography is investigated. A key-exchange protocol over a public channel is studied where the parties exchanging secret messages use multilayer neural networks which are trained by their mutual output bits and synchronize to a time dependent secret key. The weights of the networks have integer values between +/-L. Recently an algorithm for an eavesdropper which could break the key was introduced by [A. Shamir, A. Mityagin, and A. Klimov, Ramp Session (Eurocrypt, Amsterdam, 2002)]. We show that the synchronization time increases with L2 while the probability to find a successful attacker decreases exponentially with L. Hence for large L we find a secure key-exchange protocol which depends neither on number theory nor on injective trapdoor functions used in conventional cryptography. PMID:12513342

  10. Atomic hydrogen escape rate due to charge exchange with hot plasmaspheric ions

    Science.gov (United States)

    Maher, L. J.; Tinsley, B. A.

    1977-01-01

    Data on ion and electron temperatures and concentrations to several thousand kilometers of altitude were obtained from the Atmosphere Explorer C satellite for 1974 and to 850 km from Arecibo incoherent scatter radar measurements. These data were used to normalize diffusive equilibrium profiles. From these profiles and by using the neutral atmospheric model of Jacchia (1971) and a new hydrogen model, the charge-exchange-induced neutral hydrogen escape fluxes for equatorial and middle latitudes were calculated. The data confirm earlier estimates that the charge exchange loss is more important than Jeans escape for the earth. It is also found that inside the plasmapause this charge exchange process with hot plasmapheric ions is the major production and loss process for the satellite population in the hydrogen geocorona.

  11. The diurnal and solar cycle variation of the charge exchange induced hydrogen escape flux

    Science.gov (United States)

    Maher, L. J.; Tinsley, B. A.

    1978-01-01

    On the basis of ion temperature and density data at specific points and times in June 1969 provided by the OGO 6 satellite, and altitude profiles of the ion and electron temperature and concentration provided by the Arecibo radar facility over the period February 1972-April 1974, the diurnal and solar cycle variation of the charge-exchange-induced hydrogen escape flux was investigated. It was calculated that for low to moderate solar activity at Arecibo, the diurnal ratio of the maximum-to-minimum charge-exchange-induced hydrogen escape flux was approximately 6 with a peak around noon and a minimum somewhere between 0100 and 0300 h LT. This study of a limited amount of OGO 6 and Arecibo data seems to indicate that the charge-exchange-induced hydrogen escape flux increases as the F(10.7) flux increases for low to moderate solar activity.

  12. X-ray emission measurements following charge exchange between C$^{6+}$ and H$_2$

    CERN Document Server

    Fogle, M; Morgan, K; McCammon, D; Seely, D G; Draganić, I N; Havener, C C

    2014-01-01

    Lyman x-ray spectra following charge exchange between C$^{6+}$ and H$_2$ are presented for collision velocities between 400 and 2300 km/s (1--30 keV/amu). Spectra were measured by a microcalorimeter x-ray detector capable of fully resolving the C VI Lyman series emission lines though Lyman-$\\delta$. The ratios of the measured emission lines are sensitive to the angular momentum $l$-states populated during charge exchange and are used to gauge the effectiveness of different $l$-distribution models in predicting Lyman emission due to charge exchange. At low velocities, we observe that both single electron capture and double capture autoionization contribute to Lyman emission and that a statistical $l$-distribution best describes the measured line ratios. At higher velocities single electron capture dominates with the $l$-distribution peaked at the maximum $l$.

  13. Performance of multiple mini-tube heat exchangers as an internal heat exchanger of a vapor-injection cycle heat pump

    Science.gov (United States)

    Jang, Jin Yong; Jeong, Ji Hwan

    2016-04-01

    A multiple mini-tube (MMT) heat exchanger was considered as an internal heat exchanger of vapor-injection cycle heat pump. Heat transfer and pressure drop in multiple mini-tube heat exchangers were numerically and experimentally investigated. Results show that the best performance of the MMT heat exchanger can be obtained when the intermediate-pressure two-phase refrigerant is supplied to the shell-side and this refrigerant reaches a saturated vapor state at the exit of the heat exchanger.

  14. Inclusive double-charge-exchange π- production at 100 GeV/c

    International Nuclear Information System (INIS)

    Measurements of inclusive cross sections at 100 GeV/c are presented for the double-charge-exchange reactions a+p → π-X with a = π, K, or p. The measurements covered a kinematic range in the Feynman x variable of 0.3 - production is used to fit the data and demonstrates the importance of resonance production via one-pion exchange for large values of the Feynman x

  15. New charge exchange model of GEANT4 for 9Be(p,n)9B reaction

    International Nuclear Information System (INIS)

    A new data-based charge exchange model of GEANT4 dedicated to the 9Be(p,n)9B reaction is developed by taking the ENDF/B-VII.1 differential cross-section data as input. Our model yields results that are in good agreement with the experimental neutron yield spectrum data obtained for proton beams of energy (20–35) MeV. In particular, in contrast to all the considered GEANT4 hadronic models, the peak structure resulting from the discrete neutrons generated by the charge-exchange reaction is observed to be accurately reproduced in our model

  16. Spectroscopic signatures of avoided crossings caused by charge exchange in plasmas

    International Nuclear Information System (INIS)

    Electron terms in the field of two stationary Coulomb centres (TCCs) of charges Z and Z' separated by a distance R are a fundamental problem of quantum mechanics, presenting fascinating atomic physics: the terms show crossings and avoided crossings. In the latter situation, the electron has a much larger probability of tunnelling from one well to the other (i.e. of charge exchange) than in the absence of such degeneracy. These rich features of the TCC problem are also manifest in different areas of physics such as plasma spectroscopy. Recently it was shown experimentally that charge exchange, enhanced by the encounter of two TCC terms, can result in an unusual structure (a dip) in the spectral line profile emitted by a Z ion from a plasma consisting of both Z and Z' ions. In this paper we present a detailed quantitative theory of this phenomenon, in which its origin is directly traced to the avoided crossings of terms in the TCC problem. We show that our theory explains quantitatively all the results of the above experiment where such a dip was observed in a hydrogen line. We also consider in detail several prospective 'radiator-perturber' pairs for observing these signatures of charge exchange in lines of hydrogen-like ions. Further experimental studies of such dips would serve to produce not-yet-available fundamental data on charge exchange between multicharged ions, virtually inaccessible by other experimental methods. (author)

  17. Electric Field Analysis of Space Charge Injection from a Conductive Nano-Filler Electrode

    International Nuclear Information System (INIS)

    A simulation on the electric field distribution near the electrode is proposed to explain the reason for using nanosized carbon black mixed with ethylene vinyl acetate, as the electrode could lead to more charge injection into the polymer than using a deposited metal electrode. The electrode is simplified to a layer of conductive semi-spheres with fixed size and constant electric potential. By using the finite element method, it is found that both the size of the semi-spheres and the distance between adjacent semi-spheres could dramatically influence the electric field near the surface of the spheres; these are considered to be the two decisive factors for the charge injecting rate at electrodes of various materials. (condensed matter: electronicstructure, electrical, magnetic, and opticalproperties)

  18. Charge injection and accumulation in organic light-emitting diode with PEDOT:PSS anode

    Energy Technology Data Exchange (ETDEWEB)

    Weis, Martin, E-mail: martin.weis@stuba.sk [Institute of Electronics and Photonics, Slovak University of Technology, Ilkovičova 3, Bratislava 81219 (Slovakia); Otsuka, Takako; Taguchi, Dai; Manaka, Takaaki; Iwamoto, Mitsumasa, E-mail: iwamoto@ome.pe.titech.ac.jp [Department of Physical Electronics, Tokyo Institute of Technology, 2-12-1 O-okayama, Meguro-ku, Tokyo 152-8552 (Japan)

    2015-04-21

    Organic light-emitting diode (OLED) displays using flexible substrates have many attractive features. Since transparent conductive oxides do not fit the requirements of flexible devices, conductive polymer poly(3,4-ethylenedioxythiophene):poly(4-styrenesulfonate) (PEDOT:PSS) has been proposed as an alternative. The charge injection and accumulation in OLED devices with PEDOT:PSS anodes are investigated and compared with indium tin oxide anode devices. Higher current density and electroluminescence light intensity are achieved for the OLED device with a PEDOT:PSS anode. The electric field induced second-harmonic generation technique is used for direct observation of temporal evolution of electric fields. It is clearly demonstrated that the improvement in the device performance of the OLED device with a PEDOT:PSS anode is associated with the smooth charge injection and accumulation.

  19. Properties of Laser-Produced Highly Charged Heavy Ions for Direct Injection Scheme

    CERN Document Server

    Sakakibara, Kazuhiko; Hayashizaki, Noriyosu; Ito, Taku; Kashiwagi, Hirotsugu; Okamura, Masahiro

    2005-01-01

    To accelerate highly charged intense ion beam, we have developed the Direct Plasma Injection Scheme (DPIS) with laser ion source. In this scheme an ion beam from a laser ion source is injected directly to a RFQ linac without a low energy beam transport (LEBT) and the beam loss in the LEBT can be avoided. We achieved high current acceleration of carbon ions (60mA) by DPIS with the high current optimized RFQ. As the next setp we will use heavier elements like Ag, Pb, Al and Cu as target in LIS (using CO2, Nd-YAG or other laser) for DPIS and will examine properties of laser-produced plasma (the relationship of between charge state and laser power density, the current dependence of the distance from the target, etc).

  20. Solar wind charge exchange X-ray emission from Mars Model and data comparison

    OpenAIRE

    Koutroumpa, Dimitra; Modolo, Ronan; Chanteur, Gerard; Chaufray, Jean-Yves; Kharchenko, Vasili; Lallement, Rosine

    2012-01-01

    Aims. We study the soft X-ray emission induced by charge exchange (CX) collisions between solar-wind, highly charged ions and neutral atoms of the Martian exosphere. Methods. A 3D multi species hybrid simulation model with improved spatial resolution (130 km) is used to describe the interaction between the solar wind and the Martian neutrals. We calculated velocity and density distributions of the solar wind plasma in the Martian environment with realistic planetary ions description, using sp...

  1. Ion slowing down and charge exchange at small impact parameters selected by channeling: superdensity effects

    OpenAIRE

    L'Hoir, A.; Adoui, A.; Barrué, F.; Billebaud, A.; Bosch, F.; Bräuning-Demian, A.; Bräuning, H.; Cassimi, A.; Chevallier, M.; C. Cohen; Dauvergne, D; Demonchy, C.E.; Giot, L.; Kirsch, R.; Gumberidze, A

    2005-01-01

    In two experiments performed with 20-30 MeV/u highly charged heavy ions (Pb56+, U91+) channeled through thin silicon crystals, we observed the original features of superdensity, associated to the glancing collisions with atomic rows undergone by part of the incident projectiles. In particular the very high collision rate yields a quite specific charge exchange regime, that leads to a higher ionization probability than in random conditions. X-ray measurements show that electrons captured in ou...

  2. Resonant behaviour in double charge exchange reaction of π+-mesons on the nuclear photoemulsion

    International Nuclear Information System (INIS)

    The invariant-mass spectra of the ppπ- and pp systems produced in the double charge exchange (DCX) of positively charged pions on photoemulsion are analysed. A pronounced peak is observed in the ppπ- invariant-mass spectrum, while the Mpp spectrum exhibits a strong Migdal-Watson effect of the proton-proton final-state interaction. These findings are in favor of the NN-decoupled NN π pseudoscalar resonance with T=0 called d'

  3. Method of producing weakly acidic cation exchange resin particles charged with uranyl ions

    Energy Technology Data Exchange (ETDEWEB)

    Abdelmonem, N.; Ringel, H.; Zimmer, E.

    1981-07-21

    Weakly acidic cationic ion exchange resin particles are charged with uranyl ions by contacting the particles step wise with aqueous uranyl nitrate solution at higher uranium concentrations from stage to stage. An alkaline medium is added to the uranyl nitrate solution in each stage to increase the successive pH values of the uranyl nitrate solution contacting the particles in dependence upon the uranium concentration effective for maximum charging of the particles with uranyl ions.

  4. Influence of injected charge carriers on photocurrents in polymer solar cells

    OpenAIRE

    Wehenkel, Dominique J.; Koster, L. Jan Anton; Wienk, Martijn M.; Janssen, Rene A. J.

    2012-01-01

    We determine and analyze the photocurrent Jph in polymer solar cells under conditions where, no, one, or two different charge carriers can be injected by choosing appropriate electrodes and compare the experimental results to simulations based on a drift-diffusion device model that accounts for photogeneration and Langevin recombination of electrons and holes. We demonstrate that accounting for the series resistance of the device is essential to determine Jph. Without such correction, the res...

  5. Total cross sections for pion charge exchange on the proton

    Energy Technology Data Exchange (ETDEWEB)

    Breitschopf, J.

    2006-04-28

    This work describes the measurement of total SCX cross sections employing a new 4{pi} scintillation counter to perform transmission measurements in the incident pion energy range from about 38 to 250 MeV. A small 4{pi} detector box consisting of thin plastic scintillators has been constructed. The transmission technique, which was used, relates the number of transmitted charged pions to that of incident beam pions and this way effectively counts events with neutral products. The incoming negative pions were counted by three beam defining counters before they hit a target of very well known size and chemical composition. The target was placed in the box detector which was not sensitive to the neutral particles resulting from the SCX. The total cross section for emerging neutral particles was derived from the comparison of the numbers of the incoming and transmitted charged particles. The total SCX cross section on hydrogen was derived from the transmissions of a CH{sub 2} target, a carbon target and an empty target. For a detailed offline analysis all TDC, QDC and FADC information was recorded in an event by event mode for each triggered beam event. Various corrections had to be applied to the data, such as random correction, the detection of neutrals in the detector, Dalitz decay, pion decay and the radiative pion capture. This measurement covers, as the only experiment, the whole {delta}-resonance and the sp-interference region in one single experimental setup and improves the available data base for the SCX reaction. It is shown that the description of the SCX cross sections is improved if the s-wave amplitudes, that have been fixed essentially by elastic pion-nucleon scattering data, is reduced by (4{+-}1.5)%. The exact value depends on the SCX literature data included and on the parameters of the {delta}{sup 0} Breit-Wigner resonance describing the p{sub 33}-waves. This shows that p-wave as well as s-wave effects should be considered in studies of isospin

  6. Total cross sections for pion charge exchange on the proton

    International Nuclear Information System (INIS)

    This work describes the measurement of total SCX cross sections employing a new 4π scintillation counter to perform transmission measurements in the incident pion energy range from about 38 to 250 MeV. A small 4π detector box consisting of thin plastic scintillators has been constructed. The transmission technique, which was used, relates the number of transmitted charged pions to that of incident beam pions and this way effectively counts events with neutral products. The incoming negative pions were counted by three beam defining counters before they hit a target of very well known size and chemical composition. The target was placed in the box detector which was not sensitive to the neutral particles resulting from the SCX. The total cross section for emerging neutral particles was derived from the comparison of the numbers of the incoming and transmitted charged particles. The total SCX cross section on hydrogen was derived from the transmissions of a CH2 target, a carbon target and an empty target. For a detailed offline analysis all TDC, QDC and FADC information was recorded in an event by event mode for each triggered beam event. Various corrections had to be applied to the data, such as random correction, the detection of neutrals in the detector, Dalitz decay, pion decay and the radiative pion capture. This measurement covers, as the only experiment, the whole Δ-resonance and the sp-interference region in one single experimental setup and improves the available data base for the SCX reaction. It is shown that the description of the SCX cross sections is improved if the s-wave amplitudes, that have been fixed essentially by elastic pion-nucleon scattering data, is reduced by (4±1.5)%. The exact value depends on the SCX literature data included and on the parameters of the Δ0 Breit-Wigner resonance describing the p33-waves. This shows that p-wave as well as s-wave effects should be considered in studies of isospin symmetry breaking. Interestingly, our

  7. Theoretical study on charge injection and transport properties of six emitters with push–pull structure

    International Nuclear Information System (INIS)

    Highlights: • We investigated six small organic molecules by using computational approaches. • This investigation is mainly based on the Marcus electron transfer theory. • The density functional theory (DFT) was used in this investigation. • The IP, EA, reorganization energy and transfer integral were calculated. • We analyzed the charge properties of the molecules by using the computed results. - Abstract: The charge injection and transport properties of six organic light-emitting molecules with push–pull structures were studied by theoretical calculations. The ground-state geometries for the neutral, cationic and anionic states were optimized using density functional theory. Subsequently, the ionization potentials and electron affinities were calculated. We computed the reorganization energies and the transfer integrals based on the Marcus electron transfer theory. It was found that in addition to being emitters the six compounds are multifunctional materials being capable of transport for both holes and electrons. Moreover, the double-branched compound DCDPC2 was found to have higher charge injection ability and better balanced charge transport properties than single-branched compounds

  8. Scanning capacitance microscope study of a SiO2/Si interface modified by charge injection

    Science.gov (United States)

    Tomiye, H.; Yao, T.

    We have investigated the local electrical properties of an SiO2/Si structure using a scanning capacitance microscope (SCaM) combined with an atomic force and a scanning tunneling microscope (AFM and STM). The electrical properties of the Si substrate and the SiO2/Si interface vary with position. In this experiment we have injected charge into the SiO2 and investigated the nature of charge storage at the SiO2/Si interface. We have used the combined microscope to apply a pulse to the SiO2/Si sample, causing charge to be trapped in the SiO2/Si interface. We could clearly detect the local variation of interface charge in a non-destructive manner using the SCaM and simultaneously by capacitance-voltage (C-V) characterization. The volume of the C-V curve shift along the voltage axis due to trapped charges is dependent upon the density of the trapped charges. In doing this experiment we show one of the many possible applications of the combined SCaM/AFM/STM.

  9. The role of electron capture and energy exchange of positively charged particles passing through matter

    OpenAIRE

    Ulmer, W.

    2011-01-01

    The conventional treatment of the Bethe-Bloch equation for protons accounts for electron capture at the end of the projectile track by the small Barkas correction. This is only a possible way for protons, whereas for light and heavier charged nuclei the exchange of energy and charge along the track has to be accounted for by regarding the projectile charge q as a function of the residual energy. This leads to a significant modification of the Bethe-Bloch equation, otherwise the range in a med...

  10. Influence of magneto-electric coefficient for magnetic and electric charge injection properties in magneto-electric MIS capacitors

    International Nuclear Information System (INIS)

    We investigated the electric charge injection properties of a floating-gate type metal-insulator Si capacitor having different-ME gate insulators. The samples showed charge-injection type behaviour in capacitance-voltage curves, and it was revealed that the amount of injected charges can be controlled by the application of an external magnetic field. The sample having a high-ME-coefficient gate insulator showed stepwise capacitance-voltage curves unlike the normal one. These results indicate that this capacitor, which employs a magnetic gate insulator, has the potential to be used in multilevel memory by the application of an external magnetic field.

  11. Antiproton small momentum transfer charge exchange scattering on protons at 30 GeV/c

    International Nuclear Information System (INIS)

    Antiproton charge exchange scattering on protons anti pp→anti nn is investigated with 30 GeV/c antiprotons at the IHEP accelerator. The experiment confirms the existence of a structure at small angles in the angular distribution of this reaction at high energies, observed earlier

  12. Short-range NN and NΔ correlations in pion double charge exchange (DCX)

    International Nuclear Information System (INIS)

    I will review several important results related to the short-range nucleon-nucleon and delta-nucleon interaction that have been obtained from recent studies of pion double charge exchange in selected nuclei. 32 refs., 5 figs., 3 tabs

  13. Neutron-proton charge exchange scattering from 9 to 23 GeV/c

    International Nuclear Information System (INIS)

    The differential cross sections for neutron-proton charge-exchange scattering have been measured with high statistics in the region of momentum transfer squared 0.0022 and for incident neutron momenta 9< p<=23 GeV/c. (Auth.)

  14. Effect of main injection timing for controlling the combustion phasing of a homogeneous charge compression ignition engine using a new dual injection strategy

    International Nuclear Information System (INIS)

    Highlights: • A new dual injection concept is developed by minimum geometry modification. • The occurrence of combustion parameters strongly depend on main injection timing. • At higher load, premixed equivalence ratio dominates over main injection timing. • Retarded of main injection timing tends to retard combustion phasing. • Slightly retarded main injection timing is recommended to avoid intense knocking. - Abstract: Homogeneous charge compression ignition combustion of diesel fuel is implemented using a novel dual injection strategy. A new experimental technique is developed to modify a single cylinder direct injection diesel engine to run on homogeneous combustion mode. Effect of main injection timing is investigated covering a range from 26 to 8 crank angle degrees before top dead center with an interval of 3°. Retarded main injection timing is identified as a control strategy for delaying combustion phasing and a means of controlled combustion phasing of direct injection homogeneous charge compression ignition combustion. Two load conditions were investigated and it was observed that at higher load, start of combustion depends more on fuel air equivalence ratio than main injection timing, whereas at low load, it significantly varies with varying main injection timing. Significant improvements in smoke and oxides of nitrogen emissions are observed when compared with the baseline conventional combustion. By studying different combustion parameters, it is observed that there is an improvement in performance and emissions with marginal loss in thermal efficiency when the main injection timing is 20° before top dead center. This is identified as the optimum main injection timing for such homogeneous combustion under the same operating condition

  15. Experimental study of combustion and emission characteristics of ethanol fuelled port injected homogeneous charge compression ignition (HCCI) combustion engine

    Energy Technology Data Exchange (ETDEWEB)

    Maurya, Rakesh Kumar; Agarwal, Avinash Kumar [Engine Research Laboratory, Department of Mechanical Engineering, Indian Institute of Technology Kanpur, Kanpur 208 016 (India)

    2011-04-15

    The homogeneous charge compression ignition (HCCI) is an alternative combustion concept for in reciprocating engines. The HCCI combustion engine offers significant benefits in terms of its high efficiency and ultra low emissions. In this investigation, port injection technique is used for preparing homogeneous charge. The combustion and emission characteristics of a HCCI engine fuelled with ethanol were investigated on a modified two-cylinder, four-stroke engine. The experiment is conducted with varying intake air temperature (120-150 C) and at different air-fuel ratios, for which stable HCCI combustion is achieved. In-cylinder pressure, heat release analysis and exhaust emission measurements were employed for combustion diagnostics. In this study, effect of intake air temperature on combustion parameters, thermal efficiency, combustion efficiency and emissions in HCCI combustion engine is analyzed and discussed in detail. The experimental results indicate that the air-fuel ratio and intake air temperature have significant effect on the maximum in-cylinder pressure and its position, gas exchange efficiency, thermal efficiency, combustion efficiency, maximum rate of pressure rise and the heat release rate. Results show that for all stable operation points, NO{sub x} emissions are lower than 10 ppm however HC and CO emissions are higher. (author)

  16. Catalytic spectrophotometric determination of cerium by ion exchange separation coupled to a flow injection system

    International Nuclear Information System (INIS)

    A flow injection method is described intended for the determination of cerium based on its catalytic effect on the oxidation of gallocyanine by peroxydisulfate in acidic media. The proposed flow injection manifold incorporates a ion exchange separation system in the carrier stream. The decolorisation of gallocyanine due to its oxidation was used to monitor the reaction by spectrophotometry at 524 nm. The variables which affected the reaction rate were fully investigated. By this method cerium(4) can be determined in the range of 0.30-10.0 μg with a limit of detection of 0.25 μg. The relative standard deviation for ten replicate determinations of 1.0 μg of cerium(4) was 1.8 %

  17. Improved charge-coupled device detectors for high-speed, charge exchange spectroscopy studies on the DIII-D tokamak

    International Nuclear Information System (INIS)

    Charge exchange spectroscopy is one of the key ion diagnostics on the DIII-D tokamak. It allows determination of ion temperature, poloidal and toroidal velocity, impurity density, and radial electric field Er throughout the plasma. For the 2003 experimental campaign, we replaced the intensified photodiode array detectors on the central portion of the DIII-D charge exchange spectroscopy system with advanced charge-coupled device (CCD) detectors mounted on faster (f/4.7) Czerny-Turner spectrometers equipped with toroidal mirrors. The CCD detectors are improved versions of the ones installed on our edge system in 1999. The combination improved the photoelectron signal level by about a factor of 20 and the signal to noise by a factor of 2-8, depending on the absolute signal level. The new cameras also allow shorter minimum integration times while archiving to PC memory: 0.552 ms for the slower, lower-read noise (15 e) readout mode and 0.274 ms in the faster, higher-read noise (30 e) mode

  18. Charge exchange and energy loss of slowed down heavy ions channeled in silicon crystals

    International Nuclear Information System (INIS)

    This work is devoted to the study of charge exchange processes and of the energy loss of highly charged heavy ions channeled in thin silicon crystals. The two first chapters present the techniques of heavy ion channeling in a crystal, the ion-electron processes and the principle of our simulations (charge exchange and trajectory of channeled ions). The next chapters describe the two experiments performed at the GSI facility in Darmstadt, the main results of which follow: the probability per target atom of the mechanical capture (MEC) of 20 MeV/u U91+ ions as a function of the impact parameter (with the help of our simulations), the observation of the strong polarization of the target electron gas by the study of the radiative capture and the slowing down of Pb81+ ions from 13 to 8,5 MeV/u in channeling conditions for which electron capture is strongly reduced. (author)

  19. Meson exchange current and three-body force contributions to the 4He charge form factor

    International Nuclear Information System (INIS)

    Effects of meson exchange current (MEC) on the charge form factor (CFF) and charge density of 4He are investigated, including pair, mesonic and retardation current terms. The influence of three-body force (3BF) is considered by adopting the realistic wave function obtained from the nuclear Hamiltonian which explicitly includes the two-pion exchange 3BF. As a result the 3BF is found to greatly enhance the MEC contribution. When the 3BF is taken into account, the MEC contribution is shown to remove most of the discrepancy between the theoretical and experimental CFF's at the second maximum. Resulting effects on the charge density are found to yield a depression in the central region. (author)

  20. Flow injection spectrophotometric determination of low concentrations of orthosphate in natural waters employing ion exchange resin

    International Nuclear Information System (INIS)

    A simple and fast method for the determination of low concentrations of orthophosphate in natural waters is described. Ion exchange is incorporated into a flow injection system by usina a resin column in the sample loop of a proportion injector. Effects of sample aspiration rate, sampling time, eluting agent concentration, pumping rate of the sample carrier stream and interfaces, were investigated both using 32PO3-4 or 31PO3-4 with columns coupled to a gerger-muller detector and incorporated in a flow system with molybdenum blue colorinetry. (M.A.C.)

  1. Achievement of the charge exchange work diminishing of an internal combustion engine in part load

    Directory of Open Access Journals (Sweden)

    Stefan POSTRZEDNIK

    2012-01-01

    Full Text Available Internal combustion engines, used for driving of different cars, occurs not only at full load, but mostly at the part load. The relative load exchange work at the full (nominal engine load is significantly low. At the part load of the IC engine its energy efficiency ηe is significantly lower than in the optimal (nominal field range of the performance parameters. One of the numerous reasons of this effect is regular growing of the relative load exchange work of the IC engine. It is directly connected with the quantitative regulation method commonly used in the IC engines. From the thermodynamic point of view - the main reason of this effect is the throttling process (causing exergy losses occurring in the inlet and outlet channels. The known proposals for solving of this problem are based on applying of the fully electronic control of the motion of inlet, outlet valves and new reference cycles.The idea presented in the paper leads to diminishing the charge exchange work of the IC engines. The problem can be solved using presented in the paper a new concept of the reference cycle (called as eco-cycle of IC engine. The work of the engine basing on the eco-cycle occurs in two 3-stroke stages; the fresh air is delivered only once for both stages, but in range of each stage a new portion of fuel is burned. Normally the charge exchange occurs once during each engine cycle realized. Elaborated proposition bases on the elimination of chosen charge exchange processes and through this the dropping of the charge exchange work can be achieved.

  2. Charge-dependent many-body exchange and dispersion interactions in combined QM/MM simulations

    International Nuclear Information System (INIS)

    Accurate modeling of the molecular environment is critical in condensed phase simulations of chemical reactions. Conventional quantum mechanical/molecular mechanical (QM/MM) simulations traditionally model non-electrostatic non-bonded interactions through an empirical Lennard-Jones (LJ) potential which, in violation of intuitive chemical principles, is bereft of any explicit coupling to an atom’s local electronic structure. This oversight results in a model whereby short-ranged exchange-repulsion and long-ranged dispersion interactions are invariant to changes in the local atomic charge, leading to accuracy limitations for chemical reactions where significant atomic charge transfer can occur along the reaction coordinate. The present work presents a variational, charge-dependent exchange-repulsion and dispersion model, referred to as the charge-dependent exchange and dispersion (QXD) model, for hybrid QM/MM simulations. Analytic expressions for the energy and gradients are provided, as well as a description of the integration of the model into existing QM/MM frameworks, allowing QXD to replace traditional LJ interactions in simulations of reactive condensed phase systems. After initial validation against QM data, the method is demonstrated by capturing the solvation free energies of a series of small, chlorine-containing compounds that have varying charge on the chlorine atom. The model is further tested on the SN2 attack of a chloride anion on methylchloride. Results suggest that the QXD model, unlike the traditional LJ model, is able to simultaneously obtain accurate solvation free energies for a range of compounds while at the same time closely reproducing the experimental reaction free energy barrier. The QXD interaction model allows explicit coupling of atomic charge with many-body exchange and dispersion interactions that are related to atomic size and provides a more accurate and robust representation of non-electrostatic non-bonded QM/MM interactions

  3. Charge-dependent many-body exchange and dispersion interactions in combined QM/MM simulations

    Energy Technology Data Exchange (ETDEWEB)

    Kuechler, Erich R. [BioMaPS Institute and Department of Chemistry and Chemical Biology, Rutgers University, Piscataway, New Jersey 08854-8087 (United States); Department of Chemistry, University of Minnesota, Minneapolis, Minnesota 55455-0431 (United States); Giese, Timothy J.; York, Darrin M. [BioMaPS Institute and Department of Chemistry and Chemical Biology, Rutgers University, Piscataway, New Jersey 08854-8087 (United States)

    2015-12-21

    Accurate modeling of the molecular environment is critical in condensed phase simulations of chemical reactions. Conventional quantum mechanical/molecular mechanical (QM/MM) simulations traditionally model non-electrostatic non-bonded interactions through an empirical Lennard-Jones (LJ) potential which, in violation of intuitive chemical principles, is bereft of any explicit coupling to an atom’s local electronic structure. This oversight results in a model whereby short-ranged exchange-repulsion and long-ranged dispersion interactions are invariant to changes in the local atomic charge, leading to accuracy limitations for chemical reactions where significant atomic charge transfer can occur along the reaction coordinate. The present work presents a variational, charge-dependent exchange-repulsion and dispersion model, referred to as the charge-dependent exchange and dispersion (QXD) model, for hybrid QM/MM simulations. Analytic expressions for the energy and gradients are provided, as well as a description of the integration of the model into existing QM/MM frameworks, allowing QXD to replace traditional LJ interactions in simulations of reactive condensed phase systems. After initial validation against QM data, the method is demonstrated by capturing the solvation free energies of a series of small, chlorine-containing compounds that have varying charge on the chlorine atom. The model is further tested on the S{sub N}2 attack of a chloride anion on methylchloride. Results suggest that the QXD model, unlike the traditional LJ model, is able to simultaneously obtain accurate solvation free energies for a range of compounds while at the same time closely reproducing the experimental reaction free energy barrier. The QXD interaction model allows explicit coupling of atomic charge with many-body exchange and dispersion interactions that are related to atomic size and provides a more accurate and robust representation of non-electrostatic non-bonded QM

  4. Anion Exchange Capacity As a Mechanism for Deep Soil Carbon Storage in Variable Charge Soils

    Science.gov (United States)

    Dietzen, C.; James, J. N.; Ciol, M.; Harrison, R. B.

    2014-12-01

    Soil is the most important long-term sink for carbon (C) in terrestrial ecosystems, containing more C than plant biomass and the atmosphere combined. However, soil has historically been under-represented in C cycling literature, especially in regards to information about subsurface (>1.0 m) layers and processes. Previous research has indicated that Andisols with large quantities of noncrystalline, variable-charge minerals, including allophane, imogolite, and ferrihydrite, contain more C both in total and at depth than other soil types in the Pacific Northwest. The electrostatic charge of variable-charge soils depends on pH and is sometimes net positive, particularly in acid conditions, such as those commonly developed under the coniferous forests of the Pacific Northwest. However, even soils with a net negative charge may contain a mixture of negative and positive exchange sites and can hold some nutrient anions through the anion exchange capacity. To increase our understanding of the effects of variable-charge on soil organic matter stabilization, deep sampling is under way at the Fall River Long-Term Soil Productivity Site in western Washington. This site has a deep, well-drained soil with few rocks, which developed from weathered basalt and is classified as an Andisol of the Boistfort Series. Samples have been taken to a depth of 3 m at eight depth intervals. In addition to analyzing total soil C, these soils will be analyzed to determine functional groups present, cation exchange capacity, anion exchange capacity, and non-crystalline mineral content. These data will be analyzed to determine any correlations that may exist between these mineralogical characteristics, total soil C, and types of functional groups stored at depth. The most abundant organic functional groups, including carboxylic and phenolic groups, are anionic in nature, and soil positive charge may play an important role in binding and stabilizing soil organic matter and sequestering C.

  5. Spectroscopic investigation of charge injection process in the bulk-heterojunction P3HT:PCBM solar cell

    International Nuclear Information System (INIS)

    The effect of charge injection in solar cells is usually difficult to examine although it is expected to highly affect the solar cell operation. The effect of charge injection on the operation of bulk-heterojunction (BHJ) solar cells made from blend films of poly(3-hexylthiophene) (P3HT) and methanofullerene (PCBM) is studied using a spectroscopic technique combined with modulation of applied bias, termed a device modulation (DM) spectroscopic technique. The DM measurements enable selective detection of spectroscopic signals from injected P3HT polarons. The voltage dependent-DM measurements in the dark condition reveal the starting point bias of charge injection (∝0 V) and the voltage-dependence of the polaron density, directly from the spectroscopic signals. The frequency dependence of DM signals in the dark condition demonstrates that a bimolecular recombination process dominates the loss mechanism for the injected polarons (copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  6. Study of proton polarization in charge exchange process on optically oriented sodium atoms

    International Nuclear Information System (INIS)

    Using high-power adjustable dye lasers for electron spin orientation in a charge-exchange target enables to significantly increase the proton polarization efficiency. A device is described that permits to avoid growth of the polarized proton beam emittance in a charge-exchange process in a strong magnetic field. The devise main feature is the use of an intensive source of neutral hydrogen atoms and the presence of a helium additional charge-exchange target which actualy is a proton ''source''. The helium charge-exchange cell is placed in the same magnetic field of a solenoid where a cell with oriented sodium is placed, a polarized electron being captured by a proton in the latter cell. In this case the beam at the solenoid inlet and outlet is in a neutral state; emittance growth related to the effect of end magnetic fields is not observed. The device after all prouduces polarized protons, their polarization degree is measured and the effect of various factors on polarization degree is studied. The description of the laser source and laser system is given. Measurement results have shown the beam intensity of neutral 7 keV atoms which passed through a polarizer to be 2 mA. The proton current doesn't depend. On the beeld fin the region of chrge exchange for the 8 kGs magnetic field. The degree of sodium polarization was 80% and polarized proton current approximately 70 μA at a temperature of the polarized sodium cell corresponding to the density of sodium vapar approximately 3x1013 at/cm2

  7. A discussion of contributions to the 0νββ decay from the pion-charge-exchange mechanisms

    International Nuclear Information System (INIS)

    The contributions to the amplitude of the 0νββ decay, mediated by the heavy neutrino, from the two kinds of pion-charge-exchange mechanisms were discussed. The point-double-exchange mechanism is much more important for the 0 νββ decay in nuclei, compared to the point-single-exchange mechanism

  8. Calibration by precise charge injection of a sub-detector of CMS; Calibration par injection de charge du calorimetre electromagnetique de CMS

    Energy Technology Data Exchange (ETDEWEB)

    Yong-Wook Baek

    2001-01-26

    This thesis was carried out within the framework of the international collaboration which has the responsibility of the experience CMS (Compact Muon Solenoid) on LHC, at CERN. The physics of the fundamental particles which will be explored by this experiment is described within the standard model. The configuration of sub-detector of CMS is briefly described, with a particular weight on the read-out chain of the electromagnetic calorimeter. The work carried out to calibrate this chain by a precise charge injection at the input of preamplifiers is described. The 4 integrated circuits CTRL, TPLS, DAC, and injector which will constitute the components of this chain of calibration are described. The circuit of injection, which is the main circuit in this project, was imagined and developed at the laboratory in DMILL technology. This injector generates a signal which has a form identical to the signal of the detector. The measurements on the linearity of the injectors are presented. In order to know its behavior under real conditions (flow of neutrons {approx} 2 x 10{sup 13} neutrons/cm{sup 2}/10 years) where this circuit is installed in detector CMS, we submitted the prototypes of injector to irradiation and the results are summarized. The research and development on this circuit produced an integrated circuit hardened to irradiations, whose variation of slope is lower than 0.25% for an integrated of 2 x 10{sup 13} neutrons/cm{sup 2} and indestructible under 10{sup 15} neutrons/cm{sup 2}. This circuit has satisfactory qualities to be assembled on the electronic card which will treat the data of calorimeter ECAL of CMS. (author)

  9. An advanced tracker design for pointing and control of space vehicles using the charge injection device

    Science.gov (United States)

    Jones, C.; Kollodge, J. C.

    1982-01-01

    The use of charge transfer devices (CTD) in pointing and control of space vehicles is examined, with emphasis on the use of charge injection devices (CID). The selection of CTD type and CID operation, including CID signal and noise analysis and signal improvement, are discussed. Star tracking operational advantages of the CTD are pointed out, and the tracking optical concept is discussed and graphically depicted. The position interpolation procedure and the effects of rate of stellar motion on position interpolation are considered, and error analysis is examined. Finally, the breadboard and test program are discussed in detail, coarse and fine acquisition, test for star, track pattern, test procedure and results. An overall accuracy performance of approximately 0.02 pixels or approximately 0.8 arcsec for the test equipment and tracker was obtained.

  10. Analytical Evaluation of the Ratio Between Injection and Space-Charge Limited Currents in Single Carrier Organic Diodes

    OpenAIRE

    Alvarez, Angel Luis; Arredondo, Belen; Romero, Beatriz; Quintana Arregui, Patxi Xabier; Gutierrez Llorente, Araceli; Mallavia, Ricardo; Otón Sánchez, José Manuel

    2008-01-01

    An analytical, complete framework to describe the current-voltage (I-V) characteristics of organic diodes without the use of previous approaches, such as injection or bulk-limited conduction is proposed. Analytical expressions to quantify the ratio between injection and space-charge-limited current from experimental I-V characteristics in organic diodes have been derived. These are used to propose a numerical model in which both bulk transport and injection mechanisms are considered simultane...

  11. Removing Spectral Diagnostics of Galactic and Stellar X-Ray Emission from Charged Exchange Recombination

    Science.gov (United States)

    Wargelin, Brad

    2004-01-01

    Our research uses the electron beam ion trap (EBIT) at the Lawrence Livermore National Laboratory to study X-ray emission from the charge exchange (CX) of highly charged ions with neutral gases. The resulting data help to fill a void in existing experimental and theoretical understanding of this atomic physics process, and are needed to explain all or part of the observed X-ray emission from the soft X-ray background, stellar winds, the Galactic Center and Galactic Ridge, supernova ejecta, and photoionized nebulae. Appreciation of the astrophysical relevance of our work continues to grow with the publication of roughly a dozen papers in the past four years describing Chandra and XMM observations of geocoronal and heliospheric CX emission, the temporal variation of such emission and correlation with X-ray emission enhancements observed by ROSAT, the theoretical spatial distribution of that emission, and CX emission around other stars. A similar number of papers were also published during that time describing CX emission from planets and comets. We expect that the launch of ASTRSE2, with its second-generation XRS microcalo- (with 6-eV resolution), will reveal even more clearly the contributions of CX to astrophysical emission. In our EBIT work we collected CX spectra from such ions as H-like and He-like Ne, Ar, and Fe. Our early measurements were made with a high-purity Ge detector, but during the second year we began operation of the first-generation XRS microcalorimeter (a twin of the XRS on ASTRO-E) and greatly improved the resolution of our measurements from roughly 150 eV (FWHM) with the Ge detectors to 10 eV with the XRS. We found that saturation of the XRS counting apparatus, which we described in our proposal as a potential concern, is not a problem for studying CX. During the course of our research, we expanded the number of injection gases permitted by the LLNL safety team, purchased and eventually operated an atomic H source, and clearly demonstrated the

  12. Experimental and Theoretical Characterization of Artificial Muscles Based on Charge Injection in Carbon Nanotubes

    Science.gov (United States)

    Baughman, Ray

    2002-03-01

    We theoretically predicted that carbon nanotubes have the potential of providing at least an order of magnitude higher work capacity per cycle and stress generation capability, as compared with any prior-art material for directly converting electrical energy to mechanical energy. Experimental and theoretical results expand understanding of the nanotube actuation mechanism, and demonstrate that improvements in nanotube sheet and macrofiber properties correspondingly increase actuator performance. The actuation mechanism is electrochemical double-layer charge injection, which we show is dominated by band structure effects for low degrees of charge transfer and by intra-tube electrostatic repulsion when charge transfer is large. Measurements indicate that charge transfer is limited to the outer nanotubes in a nanotube bundle, which limits present performance (as does creep, nanotube misalignment, and poor inter-bundle stress transfer). Nevertheless, measured actuation stresses are 100 times that of natural muscle, and the measured gravimetric work-per-cycle (fixed load condition) is already much higher than for the hard ferroelectrics. Efforts to eliminate these problems (via debundling, nanotube welding, and improvements in nanotube spinning methods) will be described, together with the initial demonstration and analysis of chemically powered carbon nanotube muscles.

  13. ({sup 18}O,{sup 18}Ne) double charge-exchange with MAGNEX

    Energy Technology Data Exchange (ETDEWEB)

    Bondí, M.; Cappuzzello, F.; Nicolosi, D.; Tropea, S. [Dipartimento di Fisica e Astrofisica, Universitá degli studi di Catania, Catania, 95100, Italy and Istituto di Fisica Nucleare - Laboratori Nazionali del Sud, Catania, 95100 (Italy); Agodi, C.; Carbone, D.; Cavallaro, M.; Cunsolo, A. [Istituto di Fisica Nucleare - Laboratori Nazionali del Sud, Catania, 95100 (Italy); De Napoli, M.; Foti, A. [Istituto di Fisica Nucleare - Sezione di Catania, Catania, 95100 (Italy)

    2014-05-09

    An experimental study concerning Double Gamow-Teller (DGT) modes in ({sup 18}O,{sup 18}Ne) Double Charge-Exchange reactions has been very recently performed at INFN-LNS laboratory in Catania. The experiment was performed using a {sup 40}Ca solid target and a {sup 18}O Cyclotron beam at 270 MeV incident energy. Charged ejectiles produced in the reaction were momentum analyzed and identified by MAGNEX spectrometer at very forward angles. Preliminary results are presented in the present paper.

  14. Charge-Exchange Neutral Particle Analyzer Diagnostic of TJ-II

    Energy Technology Data Exchange (ETDEWEB)

    Fontdecaba, J. M.; Balbin, R.; Petrov, S.; TJ-II team

    2003-07-01

    A description of the Charge Exchange Neutral Particle Analyzers in operation in the heliac flexible TJ-II is reported. A description of the detectors, as well as the operation characteristics, hardware and software used in the control and analysis of the data obtained with the diagnostic is detailed. Two NPAs are in operation in TJ-II. One of them is a 5-channel analyzer and another one is an Acord-12. The 5-channel analyzer provides measurements of charge exchange neutral fluxes at five energy channels, whereas the Acord-12 can measure simultaneously two different hydrogen isotopes (H and D) at six energy channels. Their lines of sight can be varied poloidally in order to observe the different sections of the plasma. (Author) 10 refs.

  15. Low-energy pion double charge exchange and nucleon-nucleon correlations in nuclei

    International Nuclear Information System (INIS)

    Recent measurements of pion double-charge exchange (DCX) at energies 20 to 70 MeV are providing a new means for studying nucleon-nucleon correlations in nuclei. At these energies the nucleus is relatively transparent, allowing simpler theoretical models to be used in interpreting the data and leading to a clearer picture. Also the contribution to DCX of sequential charge-exchange scattering through the intermediate analog state is suppressed near 50 MeV and transitions through non-analog intermediate states become very important. Recent theoretical studies by several groups have shown that while transitions through the analog route involve relatively long nucleon-nucleon distances, those through non-analog intermediate states obtain nearly half their strength from nucleon pairs with less than 1 fermi separation. Thus DCX near 50 MeV is an excellent way to study short-range nucleon-nucleon correlations. 31 refs., 29 figs., 4 tabs

  16. Core polarization phenomena in pion-nucleus charge-exchange reactions above the delta resonance

    International Nuclear Information System (INIS)

    We study pion-induced single- and double-charge exchange reactions in nuclei at energies above the Δ(3/2,3/2) resonance using a microscopic, parameter-free Glauber approach. We introduce corrections in the amplitudes due to the medium polarization from an isospin-flip spin-nonflip source which dominates the reaction in the transitions studied and which has not previously been identified. Using an effective force derived from the study of electromagnetic transitions we obtain sizable reductions of the cross sections in both single- and double-charge exchanges, which bring the results of both reactions into close agreement with experiment. Predictions for angular distributions for both reactions on 14C, 18O, and 42Ca targets are made which should serve as guidelines for experiments planned in this region and as further tests of the proposed isovector renormalization

  17. Influence of resonant charge exchange on the viscosity of partially ionized plasma in a magnetic field

    International Nuclear Information System (INIS)

    The influence of resonant charge exchange for ion-atom interaction on the viscosity of partially ionized plasma embedded in the magnetic field is investigated. The general system of equations used to derive the viscosity coefficients for an arbitrary plasma component in the 21-moment approximation of Grad’s method is presented. The expressions for the coefficients of total and partial viscosities of a multicomponent partially ionized plasma in the magnetic field are obtained. As an example, the coefficients of the parallel and transverse viscosities for the ionic and neutral components of the partially ionized hydrogen plasma are calculated. It is shown that the account for resonant charge exchange can lead to a substantial change of the parallel and transverse viscosity of the plasma components in the region of low degrees of ionization on the order of 0.1

  18. Charge exchange contamination of CRIT-II barium CIV experiment. [critical ionization velocity in ionosphere

    Science.gov (United States)

    Swenson, G. R.; Mende, S. B.; Meyerott, R. E.; Rairden, R. L.

    1991-01-01

    Experiments have been recently performed which attempted to confirm critical ionization velocity (CIV) ionization by deploying chemicals at high velocity in the ionosphere. Specifically, the CRIT-II rocket performed a barium release in the ionosphere, where observations of Ba(+) resonant emissions following the release are believed to have resulted from the CIV process. Calculations are presented which suggest a significant fraction (if not all) of the Ba(+) observed likely resulted from charge exchange with the thermosphere ions and not through CIV processes. The results presented here are pertinent to other CIV experiments performed in the ionosphere. It is recommended that laboratory measurements should be made of the charge exchange cross section between O(+) and Ba as well as other metal vapors used in CIV experiments.

  19. Solar wind/local interstellar medium interaction including charge exchange with neural hydrogen

    Science.gov (United States)

    Pauls, H. Louis; Zank, Gary P.

    1995-01-01

    We present results from a hydrodynamic model of the interaction of the solar wind with the local interstellar medium (LISM), self-consistently taking into account the effects of charge exchange between the plasma component and the interstellar neutrals. The simulation is fully time dependent, and is carried out in two or three dimensions, depending on whether the helio-latitudinal dependence of the solar wind speed and number density (both giving rise to three dimensional effects) are included. As a first approximation it is assumed that the neutral component of the flow can be described by a single, isotropic fluid. Clearly, this is not the actual situation, since charge exchange with the supersonic solar wind plasma in the region of the nose results in a 'second' neutral fluid propagating in the opposite direction as that of the LISM neutrals.

  20. Solar Wind Charge Exchange X-ray Emission from Earth's Magnetosheath

    Science.gov (United States)

    Snowden, Steve L.; Kuntz, K. D.

    2016-04-01

    The magnetospheric component of solar wind charge-exchange (SWCX) emission is primarily due to interaction between the high-state ions in the solar wind and the hydrogen in the outermost part of the Earth’s atmosphere. This emission was the primary source of the ROSAT long-term enhancements (LTEs). Using the correlation between the LTEs and the solar wind flux as well as a dynamic models of the magnetosheath, we have derived the 1/4 keV broad-band charge-exchange cross-section, and can show that this method can not be directly applied to the 3/4 keV band. I will discuss the uncertainties in this method and the prospects for improvement.

  1. Analysing powers and spin correlations in deuteron–proton charge exchange at 726 MeV

    Directory of Open Access Journals (Sweden)

    S. Dymov

    2015-05-01

    Full Text Available The charge exchange of vector polarised deuterons on a polarised hydrogen target has been studied in a high statistics experiment at the COSY-ANKE facility at a deuteron beam energy of Td=726 MeV. By selecting two fast protons at low relative energy Epp, the measured analysing powers and spin correlations are sensitive to interference terms between specific neutron–proton charge-exchange amplitudes at a neutron kinetic energy of Tn≈12Td=363 MeV. An impulse approximation calculation, which takes into account corrections due to the angular distribution in the diproton, describes reasonably the dependence of the data on both Epp and the momentum transfer. This lends broad support to the current neutron–proton partial wave solution that was used in the estimation.

  2. Analysing powers and spin correlations in deuteron-proton charge exchange at 726 MeV

    CERN Document Server

    Dymov, S; Bagdasarian, Z; Barsov, S; Carbonell, J; Chiladze, D; Engels, R; Gebel, R; Grigoryev, K; Hartmann, M; Kacharava, A; Khoukaz, A; Komarov, V; Kulessa, P; Kulikov, A; Kurbatov, V; Lomidze, N; Lorentz, B; Macharashvili, G; Mchedlishvili, D; Merzliakov, S; Mielke, M; Mikirtychyants, M; Mikirtychyants, S; Nioradze, M; Ohm, H; Prasuhn, D; Rathmann, F; Serdyuk, V; Seyfarth, H; Shmakova, V; Ströher, H; Tabidze, M; Trusov, S; Tsirkov, D; Uzikov, Yu; Valdau, Yu; Weidemann, C; Wilkin, C

    2015-01-01

    The charge exchange of vector polarised deuterons on a polarised hydrogen target has been studied in a high statistics experiment at the COSY-ANKE facility at a deuteron beam energy of Td = 726 MeV. By selecting two fast protons at low relative energy E_{pp}, the measured analysing powers and spin correlations are sensitive to interference terms between specific neutron-proton charge-exchange amplitudes at a neutron kinetic energy of Tn ~ 1/2 Td =363 MeV. An impulse approximation calculation, which takes into account corrections due to the angular distribution in the diproton, describes reasonably the dependence of the data on both E_{pp} and the momentum transfer. This lends broad support to the current neutron-proton partial-wave solution that was used in the estimation.

  3. Electron capture rates in stars studied with heavy ion charge exchange reactions

    CERN Document Server

    Bertulani, C A

    2015-01-01

    Indirect methods using nucleus-nucleus reactions at high energies (here, high energies mean $\\sim$ 50 MeV/nucleon and higher) are now routinely used to extract information of interest for nuclear astrophysics. This is of extreme relevance as many of the nuclei involved in stellar evolution are short-lived. Therefore, indirect methods became the focus of recent studies carried out in major nuclear physics facilities. Among such methods, heavy ion charge exchange is thought to be a useful tool to infer Gamow-Teller matrix elements needed to describe electron capture rates in stars and also double beta-decay experiments. In this short review, I provide a theoretical guidance based on a simple reaction model for charge exchange reactions.

  4. ROSAT Observations of Solar Wind Charge Exchange with the Lunar Exosphere

    Science.gov (United States)

    Collier, Michael R.; Snowden, S. L.; Benna, M.; Carter, J. A.; Cravens, T. E.; Hills, H. Kent; Hodges, R. R.; Kuntz, K. D.; Porter, F. Scott; Read, A.; Robertson, I. P.; Sembay, S. F.; Sibeck, D. G.; Stubbs, Timothy J.; Travnicek, P.

    2012-01-01

    We analyze the ROSAT PSPC soft X-ray image of the Moon taken on 29 June 1990 by examining the radial profile of the count rate in three wedges, two wedges (one north and one south) 13-32 degrees off (19 degrees wide) the terminator towards the dark side and one wedge 38 degrees wide centered on the anti-solar direction. The radial profiles of both the north and the south wedges show substantial limb brightening that is absent in the 38 degree wide antisolar wedge. An analysis of the count rate increase associated with the limb brightening shows that its magnitude is consistent with that expected due to solar wind charge exchange (SWCX) with the tenuous lunar atmosphere. Along with Mars, Venus, and Earth, the Moon represents another solar system body at which solar wind charge exchange has been observed. This technique can be used to explore the solar wind-lunar interaction.

  5. Low-energy pion double charge exchange and nucleon-nucleon correlations in nuclei

    Energy Technology Data Exchange (ETDEWEB)

    Leitch, M.J.

    1989-01-01

    Recent measurements of pion double-charge exchange (DCX) at energies 20 to 70 MeV are providing a new means for studying nucleon-nucleon correlations in nuclei. At these energies the nucleus is relatively transparent, allowing simpler theoretical models to be used in interpreting the data and leading to a clearer picture. Also the contribution to DCX of sequential charge-exchange scattering through the intermediate analog state is suppressed near 50 MeV and transitions through non-analog intermediate states become very important. Recent theoretical studies by several groups have shown that while transitions through the analog route involve relatively long nucleon-nucleon distances, those through non-analog intermediate states obtain nearly half their strength from nucleon pairs with less than 1 fermi separation. Thus DCX near 50 MeV is an excellent way to study short-range nucleon-nucleon correlations. 31 refs., 29 figs., 4 tabs.

  6. ReO{sub x} charge injection/blocking layers in organic electronic devices

    Energy Technology Data Exchange (ETDEWEB)

    Luo Jiaxiu; Xiao Lixin; Chen Zhijian; Qu Bo; Gong Qihuang, E-mail: xiao66@pku.edu.c, E-mail: qhgong@pku.edu.c [State Key Laboratory for Mesoscopic Physics and Department of Physics, Peking University, Beijing 100871 (China)

    2010-09-29

    The charge transport of rhenium oxide (ReO{sub x}) in organic electronic devices was investigated. The hole injection/transport was blocked and the electron injection/transport was enhanced with doping of ReO{sub x} in organic electronic devices. Thus the charge balance and efficiency of organic light-emitting diodes were improved; current efficiency of 2.7 cd A{sup -1} at 20 mA cm{sup -2} for the device with ReO{sub x} was higher than 1.5 cd A{sup -1} for the device without it. In the case of organic photovoltaic cells, the open-circuit voltage (V{sub oc}), 0.58 V, was higher compared with the device without ReO{sub x} (0.44 V) due to the improvement of interface properties. The power conversion efficiency was increased to 2.27% by the combination of ReO{sub x} (increases V{sub oc}) with poly(3,4-ethylenedioxythiophene) : poly(styrene-sulfonate) (improves hole transport to increase J{sub sc}) on the modification of the anode, higher than 1.85% for the device without ReO{sub x}.

  7. What can we learn from A(π+, η)B charge exchange reaction?

    International Nuclear Information System (INIS)

    Within DWIA formalism, the η production cross sections from nuclear target by charge exchange reaction A(π+, η)B are calculated. For 13C target the cross sections at forward angles are of the order of 10 μb/sr at Tπ = 660 MeV, which can be measured experimentally. The high momentum component of the wave function of single particle bound state is essential for describing this reaction

  8. Charge-exchange excitations with finite range interactions including tensor terms

    CERN Document Server

    De Donno, V; Anguiano, M; Lallena, A M

    2014-01-01

    We study charge-exchange excitations in doubly magic-nuclei by using a self-consistent Hartree-Fock plus Random Phase Approximation model. We use four Gogny-like finite-range interactions, two of them containing tensor forces. We investigate the effects of the various parts of the tensor forces in the two computational steps of our model, and we find that their presence is not negligible and improves the agreement with the experimental data.

  9. A Schwinger-type variational principle for charge exchange at arbitrary energies

    International Nuclear Information System (INIS)

    An overview of difficulties encountered in charge exchange collision theory is presented. We emphasize problems in the most critical intermediate energy region where, as yet, no adequate method is available. A Schwinger-type variational principle, which is established at arbitrary energies, appears to exhibit many advantages over existing theories. It successfully connects the leading second Born approximation with the efficient L2-expansion methods. (orig.)

  10. Measurement of pion double charge exchange on carbon-13, carbon-14, magnesium-26, and iron-56

    International Nuclear Information System (INIS)

    Cross sections for the /sup 13,14/C,26Mg,56Fe(π+,π-)/sup 13,14/O,26Si,56Ni reactions were measured with the Energetic Pion Channel and Spectrometer at the Clinton P. Anderson Meson Physics Facility for 120 less than or equal to T/sub π/ less than or equal to 292 MeV and 0 less than or equal to theta less than or equal to 50. The double isobaric analog states (DIAS) are of primary interest. In addition, cross sections for transitions to 14O(0+, 5.92 MeV), 14O(2+, 7.77 MeV), 56Ni(gs), 13O(gs), and 13O(4.21 MeV) are presented. The 13O(4.21 MeV) state is postulated to have J/sup π/ = 1/2-. The data are compared to previously measured double-charge-exchange cross sections on other nuclei, and the systematics of double charge exchange on T greater than or equal to 1 target nuclei leading to the DIAS are studied. Near the Δ33 resonance, cross sections for the DIAS transitions are in disagreement with calculations in which the reaction is treated as sequential charge exchange through the free pion-nucleon amplitude, while for T/sub π/ > 200 MeV the anomalous features of the 164 MeV data are not apparent. This is evidence for significant higher order contributions to the double-charge-exchange amplitude near the reasonable energy. Two theoretical approaches that include two nucleon processes are applied to the DIAS data. 64 references

  11. Nuclear charge-exchange excitations in localized covariant density functional theory

    International Nuclear Information System (INIS)

    The recent progress in the studies of nuclear charge-exchange excitations with localized covariant density functional theory is briefly presented, by taking the fine structure of spin-dipole excitations in 16O as an example. It is shown that the constraints introduced by the Fock terms of the relativistic Hartree-Fock scheme into the particle-hole residual interactions are straightforward and robust. (authors)

  12. Charge-exchange emission in the starburst galaxies M82 and NGC3256

    CERN Document Server

    Ranalli, Piero

    2012-01-01

    Charge-exchange (CE) emission produces features which are detectable with the current X-ray instrumentation in the brightest near galaxies. We describe these aspects in the observed X-ray spectra of the star forming galaxies M82 and NGC 3256, from the Suzaku and XMM-Newton telescopes. Emission from both ions (O, C) and neutrals (Mg, Si) is recognised. We also describe how microcalorimeter instrumentation on future missions will improve CE observations.

  13. Nuclear charge-exchange excitations in localized covariant density functional theory

    CERN Document Server

    Liang, H Z; Nakatsukasa, T; Niu, Z M; Ring, P; Roca-Maza, X; Van Giai, N; Zhao, P W

    2014-01-01

    The recent progress in the studies of nuclear charge-exchange excitations with localized covariant density functional theory is briefly presented, by taking the fine structure of spin-dipole excitations in 16O as an example. It is shown that the constraints introduced by the Fock terms of the relativistic Hartree-Fock scheme into the particle-hole residual interactions are straightforward and robust.

  14. Production and decay of Δ'S in nuclei; emission of coherent pions in charge exchange

    International Nuclear Information System (INIS)

    The decay channels of the Δ resonance formed in nuclei, by the charge exchange reaction (3He,t) at 2 GeV, have been studied, on 2H, 4He, 12C and Pb targets, in exclusive experiments with the large acceptance detector Diogene. The quasi-free channel Δ++ -> p+ π+, the two proton decay channel and the single pion decay channel have been observed and investigated. The emission of coherent pions has been identified. (authors). 8 refs., 11 figs

  15. Charge-exchange scattering in K- p interactions below 300 MeV/c

    International Nuclear Information System (INIS)

    Cross sections for K-p charge exchange, based on new data equal in statistics to the sum of those of all previous determinations below 300 MeV/c, are presented. The results confirm an earlier observation by this collaboration that the previous measurements of these cross sections at low momentum were significantly underestimated. Evidence for the presence of P wave scattering is presented. (author)

  16. Construction of a Direct Water-Injected Two-Stroke Engine for Phased Direct Fuel Injection-High Pressure Charging Investigations

    Science.gov (United States)

    Somsel, James P.

    1998-01-01

    The development of a water injected Orbital Combustion Process (OCP) engine was conducted to assess the viability of using the powerplant for high altitude NASA aircraft and General Aviation (GA) applications. An OCP direct fuel injected, 1.2 liter, three cylinder, two-stroke engine has been enhanced to independently inject water directly into the combustion chamber. The engine currently demonstrates low brake specific fuel consumption capability and an excellent power to weight ratio. With direct water injection, significant improvements can be made to engine power, to knock limits/ignition advance timing, and to engine NO(x) emissions. The principal aim of the testing was to validate a cyclic model developed by the Systems Analysis Branch at NASA Ames Research Center. The work is a continuation of Ames' investigations into a Phased Direct Fuel Injection Engine with High Pressure Charging (PDFI-ITPC).

  17. Dimensional changes as a function of charge injection for trans-polyacetylene: A density functional theory study

    Science.gov (United States)

    Sun, Guangyu; Kurti, Jeno; Kertesz, Miklos; Baughman, Ray H.

    2002-10-01

    Charge-induced dimensional changes allow conducting polymers and single walled carbon nanotubes to function as electromechanical actuators. The unit cell of the prototypical conducting polymer, trans-polyacetylene, was calculated as a function of charge injection using density functional theory in combination with ultrasoft pseudopotentials using the solid-state Vienna ab initio simulation package. Test calculations on the charged pyridinium molecular ion give results in good agreement with the experimental geometry. Strain versus charge relationships are predicted from dimensional changes calculated using a uniform background charge ("jellium") for representing the counterions, which we show provides results consistent with experiment for doped polyacetylenes. These jellium calculations are consistent with further presented calculations that include specific counterions, showing that hybridization between the guest dopant ions and the host polyacetylene chains is unimportant. The lack of guest-host orbital hybridization allows a qualitative rigid band interpretation of the amount of charge transfer for both acceptor and donor doping. For polyacetylene, asymmetry of strain along the chain with respect to the sign of the charge is predicted: negative charge elongates and positive charge shortens the polymer. For charge less than 0.05e per carbon, an approximately linear dependence is obtained for the dependence of chain-direction strain on the amount of injected charge.

  18. Wavelength calibration of the charge exchange recombination spectroscopy system on the DIII-D tokamak

    International Nuclear Information System (INIS)

    A wavelength calibration of all the detectors on the charge exchange recombination spectroscopy (CER) system is performed after every plasma discharge on the DIII-D tokamak. This is done to insure that the rest wavelength position of the C VI 5290.5 angstrom charge exchange line on the detector is accurately known so that the Doppler shift of the spectral line emitted during the discharge can be used for measurements of plasma rotation. In addition, this calibration provides a check on the spectral dispersion needed to determine the ion temperature. The reference spectra for the calibration are Ne I lines created by neon capillary discharge lamps contained within specially designed, diffuse reflectors. The Ne I lines at 3520.4720 angstrom, 5274.0393 angstrom, 5280.0853 angstrom, 5298.1891 angstrom, and 5304.7580 angstrom are used in this work. The location of these lines on the linear detectors can be determined to an accuracy of 0.1 pixel, which corresponds to a plasma rotation accuracy of 1.2 km/s and 0.7 km/s for the central and edge rotation measurements, respectively. Use of oppositely directed views of the plasma at the same major radius have been used to verify that the nominal 5290.5 angstrom wavelength of the C VI (n = 8 → 7) multiplet is the correct wavelength for the line emitted owing to charge exchange excitation

  19. Coherent control of charge exchange in strong-field dissociation of LiF

    Science.gov (United States)

    Armstrong, Greg; Esry, Brett

    2016-05-01

    The alkali-metal-halides family of molecules are useful prototypes in the study of laser-assisted charge exchange. Typically these molecules possess a field-free crossing between the ionic and covalent diabatic Born-Oppenheimer potential curves, leading to Li+ + F- and Li + F in LiF. These channels are energetically well-separated from higher-lying potentials, and may be easily distinguished experimentally. Moreover, charge exchange involves non-adiabatic transitions between the ionic and covalent channels, thereby allowing the investigation of physics beyond the Born-Oppenheimer approximation. The focus of this work is to control the preference between ionic and covalent dissociative products. We solve the time-dependent Schrödinger equation for the nuclear motion in full dimensionality, and investigate a pump-probe scheme for charge-exchange control. The degree of control is investigated by calculating the kinetic-energy release spectrum as a function of pump-probe delay for the ionic and covalent fragments. This work is supported by the Chemical Sciences, Geosciences, and Biosciences Division, Office of Basic Energy Sciences, Office of Science, U.S. Department of Energy.

  20. Modeling the Hydrogen-Proton Charge-Exchange Process in Global Heliospheric Simulations

    Science.gov (United States)

    DeStefano, A.; Heerikhuisen, J.

    2015-12-01

    The environment surrounding our Solar System has a vast and dynamic structure. As the Sun rounds the Milky Way galaxy, interstellar dust and gas interact with the Sun's outflow of solar wind. A bubble of hot plasma forms around the Sun due to this interaction, called the heliosphere. In order to understand the structure of the heliosphere, observations and simulations must work in tandem. Within the past decade or so, 3D models of the heliosphere have been developed exhibiting non- symmmetric as well as predicting structures such as the hydrogen wall and the IBEX ribbon. In this poster we explore new ways to compute charge-exchange source terms. The charge-exchange process is the coupling mechanism between the MHD and kinetic theories. The understanding of this process is crucial in order to make valuable predictions. Energy dependant cross section terms will aid in settling non-linear affects coupling the intestellar and solar particles. Through these new ways of computing source terms, resolving fine structures in the plasma in the heliopause may be possible. In addition, other non-trivial situations, such as charge-exchange mediated shocks, may be addressed.

  1. X-ray Emission Measurements following Charge Exchange between C6+ and He

    Energy Technology Data Exchange (ETDEWEB)

    Defay, X [University of Wisconsin, Madison; Morgan, K [University of Wisconsin, Madison; McCammon, D [University of Wisconsin, Madison; Wulf, D. [University of Wisconsin, Madison; Andrianarijaona, V. M. [Pacific Union College; Fogle, Jr., M R, [Auburn University, Auburn, Alabama; Seely, D. G. [Albion College; Draganic, Ilija N [ORNL; Havener, Charles C [ORNL

    2013-01-01

    X-ray spectra following charge exchange collisions between C6+ and He are presented for collision energies between 460 eV/u and 32,000 eV/u. Spectra were obtained at the Oak Ridge National Laboratory ion-atom merged-beams apparatus, using a microcalorimeter X-ray detector capable of fully resolving the C VI Lyman series lines through Ly-gamma. These line ratios are sensitive to the initial electron