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Sample records for charged particle energy

  1. Coaxial charged particle energy analyzer

    NASA Technical Reports Server (NTRS)

    Kelly, Michael A. (Inventor); Bryson, III, Charles E. (Inventor); Wu, Warren (Inventor)

    2011-01-01

    A non-dispersive electrostatic energy analyzer for electrons and other charged particles having a generally coaxial structure of a sequentially arranged sections of an electrostatic lens to focus the beam through an iris and preferably including an ellipsoidally shaped input grid for collimating a wide acceptance beam from a charged-particle source, an electrostatic high-pass filter including a planar exit grid, and an electrostatic low-pass filter. The low-pass filter is configured to reflect low-energy particles back towards a charged particle detector located within the low-pass filter. Each section comprises multiple tubular or conical electrodes arranged about the central axis. The voltages on the lens are scanned to place a selected energy band of the accepted beam at a selected energy at the iris. Voltages on the high-pass and low-pass filters remain substantially fixed during the scan.

  2. EXTRACTOR FOR HIGH ENERGY CHARGED PARTICLES

    DOEpatents

    Lambertson, G.R.

    1964-04-01

    A particle-extracting apparatus for use with a beam of high-energy charged particles such as travel in an evacuated chamber along a circular equilibrium axis is described. A magnetized target is impacted relatively against the beam whereby the beam particles are deflected from the beam by the magnetic induction in the target. To this end the target may be moved into the beam or the beam may coast into the target and achieve high angular particle deflection and slow extraction. A deflecting septum magnet may additionally be used for deflection at even sharper angles. (AEC)

  3. Medium energy charged particle data for evaluation

    SciTech Connect

    Pearlstein, S.

    1989-01-01

    Medium energy charged particles incident on targets can cause a variety of nuclear reactions. Charged particle transport calculations require access to a large body of cross-section data which results in interest in an evaluated charge particle data library. Developing an evaluated data library can involve several steps. An index to the literature on measurements and theory is useful to locate information relevant to data evaluation. A computerized compilation of measurements facilitates the intercomparison of different experiments and the determination of how well data are known. Nuclear models, based on theory or phenonological evidence, are compared with experiment and where validated, are used to fill in regions where experimental data are not available. Finally, the selected data is placed into computer readable formats for use in transport calculations. 16 refs.

  4. Confined energy distribution for charged particle beams

    DOEpatents

    Jason, Andrew J.; Blind, Barbara

    1990-01-01

    A charged particle beam is formed to a relatively larger area beam which is well-contained and has a beam area which relatively uniformly deposits energy over a beam target. Linear optics receive an accelerator beam and output a first beam with a first waist defined by a relatively small size in a first dimension normal to a second dimension. Nonlinear optics, such as an octupole magnet, are located about the first waist and output a second beam having a phase-space distribution which folds the beam edges along the second dimension toward the beam core to develop a well-contained beam and a relatively uniform particle intensity across the beam core. The beam may then be expanded along the second dimension to form the uniform ribbon beam at a selected distance from the nonlinear optics. Alternately, the beam may be passed through a second set of nonlinear optics to fold the beam edges in the first dimension. The beam may then be uniformly expanded along the first and second dimensions to form a well-contained, two-dimensional beam for illuminating a two-dimensional target with a relatively uniform energy deposition.

  5. High Energy Charged Particles in Space at One Astronomical Unit

    NASA Technical Reports Server (NTRS)

    Feynman, J.; Gabriel, S. B.

    1995-01-01

    Single event effects and many other spacecraft anomalies are caused by positively charged high energy particles impinging on the vehicle and its component parts. Reviewed here are the current knowledge of the interplanetary particle environment in the energy ranges that are most important for these effects. State-of-the-art engineering models are briefly described along with comments on the future work required.

  6. Charged-particle mutagenesis 2. Mutagenic effects of high energy charged particles in normal human fibroblasts

    NASA Technical Reports Server (NTRS)

    Chen, D. J.; Tsuboi, K.; Nguyen, T.; Yang, T. C.

    1994-01-01

    The biological effects of high Linear Energy Transfer (LET) charged particles are a subject of great concern with regard to the prediction of radiation risk in space. In this report, mutagenic effects of high LET charged particles are quantitatively measured using primary cultures of human skin fibroblasts, and the spectrum of induced mutations are analyzed. The LET of the charged particles ranged from 25 KeV/micrometer to 975 KeV/micrometer with particle energy (on the cells) between 94-603 MeV/u. The X-chromosome linked hypoxanthine guanine phosphoribosyl transferase (hprt) locus was used as the target gene. Exposure to these high LET charged particles resulted in exponential survival curves; whereas, mutation induction was fitted by a linear model. The Relative Biological Effect (RBE) for cell-killing ranged from 3.73 to 1.25, while that for mutant induction ranged from 5.74 to 0.48. Maximum RBE values were obtained at the LET of 150 keV/micrometer. The inactivation cross-section (alpha i) and the action cross-section for mutant induction (alpha m) ranged from 2.2 to 92.0 sq micrometer and 0.09 to 5.56 x 10(exp -3) sq micrometer respectively. The maximum values were obtained by Fe-56 with an LET of 200 keV/micrometer. The mutagenicity (alpha m/alpha i) ranged from 2.05 to 7.99 x 10(exp -5) with the maximum value at 150 keV/micrometer. Furthermore, molecular analysis of mutants induced by charged particles indicates that higher LET beams are more likely to cause larger deletions in the hprt locus.

  7. Charged-particle mutagenesis II. Mutagenic effects of high energy charged particles in normal human fibroblasts

    NASA Astrophysics Data System (ADS)

    Chen, D. J.; Tsuboi, K.; Nguyen, T.; Yang, T. C.

    1994-10-01

    The biological effects of high LET charged particles are a subject of great concern with regard to the prediction of radiation risk in space. In this report, mutagenic effects of high LET charged particles are quantitatively measured using primary cultures of human skin fibroblasts, and the spectrum of induced mutations are analyzed. The LET of the charged particles ranged from 25 KeV/μm to 975 KeV/gmm with particle energy (on the cells) between 94 - 603 MeV/u. The X-chromosome linked hypoxanthine guanine phosphoribosyl transferase (hprt) locus was used as the target gene. Exposure to these high LET charged particles resulted in exponential survival curves; whereas, mutation induction was fitted by a linear model. The Relative Biological Effect (RBE) for cell-killing ranged from 3.73 to 1.25, while that for mutant induction ranged from 5.74 to 0.48. Maximum RBE values were obtained at the LET of 150 keV/μm. The inactivation cross-section (αi) and the action-section for mutant induction (αm) ranged from 2.2 to 92.0 μm2 and 0.09 to 5.56 × 10-3 μm2, respectively. The maximum values were obtained by 56Fe with an LET of 200 keV/μm. The mutagenicity (αm/αi) ranged from 2.05 to 7.99 × 10-5 with the maximum value at 150 keV/μm. Furthermore, molecular analysis of mutants induced by charged particles indicates that higher LET beams are more likely to cause larger deletions in the hprt locus.

  8. Charged-particle mutagenesis II. Mutagenic effects of high energy charged particles in normal human fibroblasts

    NASA Technical Reports Server (NTRS)

    Chen, D. J.; Tsuboi, K.; Nguyen, T.; Yang, T. C.

    1994-01-01

    The biological effects of high LET charged particles are a subject of great concern with regard to the prediction of radiation risk in space. In this report, mutagenic effects of high LET charged particles are quantitatively measured using primary cultures of human skin fibroblasts, and the spectrum of induced mutations are analyzed. The LET of the charged particles ranged from 25 KeV/micrometer to 975 KeV/micrometer with particle energy (on the cells) between 94-603 MeV/u. The X-chromosome linked hypoxanthine guanine phosphoribosyl transferase (hprt) locus was used as the target gene. Exposure to these high LET charged particles resulted in exponential survival curves; whereas, mutation induction was fitted by a linear model. The Relative Biological Effect (RBE) for cell-killing ranged from 3.73 to 1.25, while that for mutant induction ranged from 5.74 to 0.48. Maximum RBE values were obtained at the LET of 150 keV/micrometer. The inactivation cross-section (alpha i) and the action cross-section for mutant induction (alpha m) ranged from 2.2 to 92.0 micrometer2 and 0.09 to 5.56 x 10(-3) micrometer2, respectively. The maximum values were obtained by 56Fe with an LET of 200 keV/micrometer. The mutagenicity (alpha m/alpha i) ranged from 2.05 to 7.99 x 10(-5) with the maximum value at 150 keV/micrometer. Furthermore, molecular analysis of mutants induced by charged particles indicates that higher LET beams are more likely to cause larger deletions in the hprt locus.

  9. Mariner-Jupiter-Saturn Low Energy Charged Particle Experiment

    NASA Technical Reports Server (NTRS)

    Peletier, D. P.; Gary, S. A.; Hogrefe, A. F.

    1977-01-01

    The Low Energy Charged Particle Experiment will be launched on the Mariner-Jupiter-Saturn spacecraft in August 1977. The experiment has been designed to perform particle measurements in the intense radiation belts of the Jovian and Saturnian environments, and to provide detailed spectral analysis of both solar and galactic particles in interplanetary space. A single instrument uses 23 solid-state detectors configured in two distinct detector subsystems: one optimized for interplanetary and interstellar measurements, the other for specific particle species, energies, and intensities expected near the planets.

  10. Charged-particle multiplicity at LHC energies

    ScienceCinema

    None

    2016-07-12

    The talk presents the measurement of the pseudorapidity density and the multiplicity distribution with ALICE at the achieved LHC energies of 0.9 and 2.36 TeV.An overview about multiplicity measurements prior to LHC is given and the related theoretical concepts are briefly discussed.The analysis procedure is presented and the systematic uncertainties are detailed. The applied acceptance corrections and the treatment of diffraction are discussed.The results are compared with model predictions. The validity of KNO scaling in restricted phase space regions is revisited. 

  11. Low energy charged particles interacting with amorphous solid water layers.

    PubMed

    Horowitz, Yonatan; Asscher, Micha

    2012-04-01

    The interaction of charged particles with condensed water films has been studied extensively in recent years due to its importance in biological systems, ecology as well as interstellar processes. We have studied low energy electrons (3-25 eV) and positive argon ions (55 eV) charging effects on amorphous solid water (ASW) and ice films, 120-1080 ML thick, deposited on ruthenium single crystal under ultrahigh vacuum conditions. Charging the ASW films by both electrons and positive argon ions has been measured using a Kelvin probe for contact potential difference (CPD) detection and found to obey plate capacitor physics. The incoming electrons kinetic energy has defined the maximum measurable CPD values by retarding further impinging electrons. L-defects (shallow traps) are suggested to be populated by the penetrating electrons and stabilize them. Low energy electron transmission measurements (currents of 0.4-1.5 μA) have shown that the maximal and stable CPD values were obtained only after a relatively slow change has been completed within the ASW structure. Once the film has been stabilized, the spontaneous discharge was measured over a period of several hours at 103 ± 2 K. Finally, UV laser photo-emission study of the charged films has suggested that the negative charges tend to reside primarily at the ASW-vacuum interface, in good agreement with the known behavior of charged water clusters.

  12. Low energy charged particles interacting with amorphous solid water layers

    NASA Astrophysics Data System (ADS)

    Horowitz, Yonatan; Asscher, Micha

    2012-04-01

    The interaction of charged particles with condensed water films has been studied extensively in recent years due to its importance in biological systems, ecology as well as interstellar processes. We have studied low energy electrons (3-25 eV) and positive argon ions (55 eV) charging effects on amorphous solid water (ASW) and ice films, 120-1080 ML thick, deposited on ruthenium single crystal under ultrahigh vacuum conditions. Charging the ASW films by both electrons and positive argon ions has been measured using a Kelvin probe for contact potential difference (CPD) detection and found to obey plate capacitor physics. The incoming electrons kinetic energy has defined the maximum measurable CPD values by retarding further impinging electrons. L-defects (shallow traps) are suggested to be populated by the penetrating electrons and stabilize them. Low energy electron transmission measurements (currents of 0.4-1.5 μA) have shown that the maximal and stable CPD values were obtained only after a relatively slow change has been completed within the ASW structure. Once the film has been stabilized, the spontaneous discharge was measured over a period of several hours at 103 ± 2 K. Finally, UV laser photo-emission study of the charged films has suggested that the negative charges tend to reside primarily at the ASW-vacuum interface, in good agreement with the known behavior of charged water clusters.

  13. Low energy charged particles interacting with amorphous solid water layers

    SciTech Connect

    Horowitz, Yonatan; Asscher, Micha

    2012-04-07

    The interaction of charged particles with condensed water films has been studied extensively in recent years due to its importance in biological systems, ecology as well as interstellar processes. We have studied low energy electrons (3-25 eV) and positive argon ions (55 eV) charging effects on amorphous solid water (ASW) and ice films, 120-1080 ML thick, deposited on ruthenium single crystal under ultrahigh vacuum conditions. Charging the ASW films by both electrons and positive argon ions has been measured using a Kelvin probe for contact potential difference (CPD) detection and found to obey plate capacitor physics. The incoming electrons kinetic energy has defined the maximum measurable CPD values by retarding further impinging electrons. L-defects (shallow traps) are suggested to be populated by the penetrating electrons and stabilize them. Low energy electron transmission measurements (currents of 0.4-1.5 {mu}A) have shown that the maximal and stable CPD values were obtained only after a relatively slow change has been completed within the ASW structure. Once the film has been stabilized, the spontaneous discharge was measured over a period of several hours at 103 {+-} 2 K. Finally, UV laser photo-emission study of the charged films has suggested that the negative charges tend to reside primarily at the ASW-vacuum interface, in good agreement with the known behavior of charged water clusters.

  14. Charged particle detectors with active detector surface for partial energy deposition of the charged particles and related methods

    DOEpatents

    Gerts, David W; Bean, Robert S; Metcalf, Richard R

    2013-02-19

    A radiation detector is disclosed. The radiation detector comprises an active detector surface configured to generate charge carriers in response to charged particles associated with incident radiation. The active detector surface is further configured with a sufficient thickness for a partial energy deposition of the charged particles to occur and permit the charged particles to pass through the active detector surface. The radiation detector further comprises a plurality of voltage leads coupled to the active detector surface. The plurality of voltage leads is configured to couple to a voltage source to generate a voltage drop across the active detector surface and to separate the charge carriers into a plurality of electrons and holes for detection. The active detector surface may comprise one or more graphene layers. Timing data between active detector surfaces may be used to determine energy of the incident radiation. Other apparatuses and methods are disclosed herein.

  15. Electron optics of spheroid charged particle energy analyzers

    NASA Astrophysics Data System (ADS)

    Cubric, D.; Kholine, N.; Konishi, I.

    2011-07-01

    A new class of charged particle energy analyzers, spheroid energy analyzers (SEA) that are characterized with very high energy resolution and transmission, is presented. A prototype analyzer was built that has achieved a relative energy resolution of 0.05% at a transmission of 21% out of a 2π steradian. A very high order of focusing of these analyzers is presented via simulation that indicates the existence of 13th order focusing in one of our models. This promises further improvements in energy resolution in future practical analyzer embodiments. A novel geometrical framework is presented, which describes SEA analyzers in general terms within which well known types of analyzers CMA and CHA appear to be only particular examples.

  16. MOS Circuitry Would Detect Low-Energy Charged Particles

    NASA Technical Reports Server (NTRS)

    Sinha, Mahadeva; Wadsworth, Mark

    2003-01-01

    Metal oxide semiconductor (MOS) circuits for measuring spatially varying intensities of beams of low-energy charged particles have been developed. These circuits are intended especially for use in measuring fluxes of ions with spatial resolution along the focal planes of mass spectrometers. Unlike prior mass spectrometer focal-plane detectors, these MOS circuits would not be based on ion-induced generation of electrons, and photons; instead, they would be based on direct detection of the electric charges of the ions. Hence, there would be no need for microchannel plates (for ion-to-electron conversion), phosphors (for electron-to-photon conversion), and photodetectors (for final detection) -- components that degrade spatial resolution and contribute to complexity and size. The developmental circuits are based on linear arrays of charge-coupled devices (CCDs) with associated readout circuitry (see figure). They resemble linear CCD photodetector arrays, except that instead of a photodetector, each pixel contains a capacitive charge sensor. The capacitor in each sensor comprises two electrodes (typically made of aluminum) separated by a layer of insulating material. The exposed electrode captures ions and accumulates their electric charges during signal-integration periods.

  17. Use of incomplete energy recovery for the energy compression of large energy spread charged particle beams

    DOEpatents

    Douglas, David R.; Benson, Stephen V.

    2007-01-23

    A method of energy recovery for RF-base linear charged particle accelerators that allows energy recovery without large relative momentum spread of the particle beam involving first accelerating a waveform particle beam having a crest and a centroid with an injection energy E.sub.o with the centroid of the particle beam at a phase offset f.sub.o from the crest of the accelerating waveform to an energy E.sub.full and then recovering the beam energy centroid a phase f.sub.o+Df relative to the crest of the waveform particle beam such that (E.sub.full-E.sub.o)(1+cos(f.sub.o+Df))>dE/2 wherein dE=the full energy spread, dE/2=the full energy half spread and Df=the wave form phase distance.

  18. Energy loss of a heavy particle near 3D charged rotating hairy black hole

    NASA Astrophysics Data System (ADS)

    Naji, Jalil

    2014-01-01

    In this paper we consider a charged rotating black hole in three dimensions with a scalar charge and discuss the energy loss of a heavy particle moving near the black-hole horizon. We also study quasi-normal modes and find the dispersion relations. We find that the effect of scalar charge and electric charge increases the energy loss.

  19. High-Energy Charged Particles in the Innermost Jovian Magnetosphere

    PubMed

    Fischer; Pehlke; Wibberenz; Lanzerotti; Mihalov

    1996-05-10

    The energetic particles investigation carried by the Galileo probe measured the energy and angular distributions of the high-energy particles from near the orbit of Io to probe entry into the jovian atmosphere. Jupiter's inner radiation region had extremely large fluxes of energetic electrons and protons; intensities peaked at approximately2.2RJ (where RJ is the radius of Jupiter). Absorption of the measured particles was found near the outer edge of the bright dust ring. The instrument measured intense fluxes of high-energy helium ions (approximately62 megaelectron volts per nucleon) that peaked at approximately1.5RJ inside the bright dust ring. The abundances of all particle species decreased sharply at approximately1.35RJ; this decrease defines the innermost edge of the equatorial jovian radiation.

  20. On the Energy and Momentum of an Accelerated Charged Particle and the Sources of Radiation

    ERIC Educational Resources Information Center

    Eriksen, Erik; Gron, Oyvind

    2007-01-01

    We give a systematic development of the theory of the radiation field of an accelerated charged particle with reference to an inertial reference frame in flat spacetime. Special emphasis is given to the role of the Schott energy and momentum in the energy-momentum balance of the charge and its field. It is shown that the energy of the radiation…

  1. Energy deposition rates by charged particles. [in upper atmosphere

    NASA Technical Reports Server (NTRS)

    Torkar, K. M.; Urban, A.; Bjordal, J.; Lundblad, J. A.; Soraas, F.; Smith, L. G.; Dumbs, A.; Grandal, B.; Ulwick, J. C.; Vancour, R. P.

    1985-01-01

    A summary of measurements of the precipitation of electrons and positive ions (in the keV-MeV range) detected aboard eight rockets launched within the Energy Budget Campaign from Northern Scandinavia is given, together with corresponding satellite data. In some cases strong temporal variations of the downgoing integral fluxes were observed. The fluxes provide the background for the calculated ion production rates and altitude profiles of the energy deposition into the atmosphere at different levels of geomagnetic disturbance and cosmic noise absorption. The derived ion production rates by eneretic particles are compared to other night-time ionisation sources.

  2. Energy straggling eliminated as a limitation to charge resolution of transmission detectors. [used for particle identification

    NASA Technical Reports Server (NTRS)

    Tarle, G.; Ahlen, S. P.; Price, P. B.

    1981-01-01

    It is pointed out that detectors of the energy loss of penetrating charged particles are widely used for particle identification. These measurements are hampered, however, by fluctuations in the amount of energy deposited within the detector. It is shown that this limitation can be overcome with a new nuclear track detector, CR-39(DOP), and that the charge resolution of this detector exceeds that of any other, including semiconductor diodes.

  3. Initial observations of low energy charged particles near the earth's bow shock on ISEE-1

    NASA Technical Reports Server (NTRS)

    Ipavich, F. M.; Gloeckler, G.; Fan, C. Y.; Fisk, L. A.; Hovestadt, D.; Klecker, B.; Scholer, M.; Ogallagher, J. J.

    1979-01-01

    Initial measurements from the ULECA sensor of the Max-Planck-Institut/University of Maryland experiment on ISEE 1 are reported. ULECA is an electrostatic deflection - total energy sensor consisting of a collimator, a deflection analyzer, and an array of solid-state detectors. The position of a given detector, which determines the energy per charge of an incident particle, together with the measured energy, determines the particle's charge state. It is found that a rich variety of phenomena are operative in the transthermal energy regime (about 10 keV/Q to 100 keV/Q) covered by ULECA. Specifically, observations are presented of locally accelerated protons, alpha particles, and heavier ions in the magnetosheath and upstream of earth's bow shock. Preliminary analysis indicates that the behavior of these locally accelerated particles is most similar at the same energy per charge.

  4. A scaled experiment to study energy dissipation process during longitudinal compression of charged particle beams

    NASA Astrophysics Data System (ADS)

    Sakai, Y.; Nakajima, M.; Hasegawa, J.; Kikuchi, T.; Horioka, K.

    2016-03-01

    Beam behavior during longitudinal bunch compression of charged particles was investigated using a compact simulator device based on electron beams. Beam current waveforms and bunch compression ratios were measured as a function of the initial beam current. We found that the current waveform became blunt and the compression ratio degraded at higher beam currents. These results indicate that space-charge fields dissipate the kinetic energy of beam particles.

  5. Particle charge spectrometer

    NASA Technical Reports Server (NTRS)

    Fuerstenau, Stephen D. (Inventor)

    2004-01-01

    An airflow through a tube is used to guide a charged particle through the tube. A detector may be used to detect charge passing through the tube on the particle. The movement of the particle through the tube may be used to both detect its charge and size.

  6. A 2-D Implicit, Energy and Charge Conserving Particle In Cell Method

    SciTech Connect

    McPherson, Allen L.; Knoll, Dana A.; Cieren, Emmanuel B.; Feltman, Nicolas; Leibs, Christopher A.; McCarthy, Colleen; Murthy, Karthik S.; Wang, Yijie

    2012-09-10

    Recently, a fully implicit electrostatic 1D charge- and energy-conserving particle-in-cell algorithm was proposed and implemented by Chen et al ([2],[3]). Central to the algorithm is an advanced particle pusher. Particles are moved using an energy conserving scheme and are forced to stop at cell faces to conserve charge. Moreover, a time estimator is used to control errors in momentum. Here we implement and extend this advanced particle pusher to include 2D and electromagnetic fields. Derivations of all modifications made are presented in full. Special consideration is taken to ensure easy coupling into the implicit moment based method proposed by Taitano et al [19]. Focus is then given to optimizing the presented particle pusher on emerging architectures. Two multicore implementations, and one GPU (Graphics Processing Unit) implementation are discussed and analyzed.

  7. The effect of induced charges on low-energy particle trajectories near conducting and semiconducting plates

    NASA Technical Reports Server (NTRS)

    Coffey, Victoria N.; Moore, Thomas E.

    1992-01-01

    The effect of the induced charge was found on particles less than 1 eV as they passed through simulated parallel, grounded channels that are comparable in dimension to those that are presently in space plasma instruments which measure the flux of low-energy ions. Applications were made to both conducting and semiconducting channels that ranged in length from 0.1 to 50 mm and in aspect ratio from 1 to 100. The effect of the induced charge on particle trajectories from simple straight lines. Several configurations of channel aspect ratio and detector locations are considered. The effect is important only at very low energies with small dimensions.

  8. Some remarks about lateral distribution function of charged particles at energy above 1017 eV

    NASA Astrophysics Data System (ADS)

    Cotzomi, J.; Fomin, Yu.A.; Kalmykov, N.N.; Kulikov, G.V.; Sulakov, V.P.

    The lateral distribution funtion (LDF) of charged particles is a basic characteristics of extensive air showers (EAS). It is necessary for determination of total number of particles at observation level and this number is used as an estima of primary energy. We consider the experimental LDF's obtained with MSU, Yakutsk and AGASA arrays. It should be noted that scintillator detectors of the AGASA and Yakutsk arrays detectors measure the energy deposit of shower particles at different distances from shower core whereas Geiger counters employed at the MSU array measure the number of charged particles directly. Experimental data are compared with calculations in the framework of the QGSJET model. It is shown that some discrepancy between various LDF's exists.

  9. Polarization correction in the theory of energy losses by charged particles

    SciTech Connect

    Makarov, D. N. Matveev, V. I.

    2015-05-15

    A method for finding the polarization (Barkas) correction in the theory of energy losses by charged particles in collisions with multielectron atoms is proposed. The Barkas correction is presented in a simple analytical form. We make comparisons with experimental data and show that applying the Barkas correction improves the agreement between theory and experiment.

  10. Low-energy Charged Particle Measurements in the Heliosheath

    NASA Astrophysics Data System (ADS)

    Decker, R. B.

    2011-12-01

    This talk will focus on recent measurements from the LECP instruments on Voyager 1 and Voyager 2. Voyager 1 (118 AU, N34 deg.) crossed the termination shock at 94.0 AU in Dec. 2004 and is roughly 24 AU into the inner heliosheath. Voyager 2 (96 AU, S30 deg) crossed the shock at 83.5 AU in Sep. 2007 and is roughly 13 AU into the heliosheath. Large variations in the intensities, energy spectra, and angular distributions of low-energy heliosheath ions and electrons have occurred during the past year, evidently in response to an increase in the number of solar active regions in January 2010. For example, starting around 2010.8, ion intensities at Voyager 1 began a two-step exponential decrease. The intensities of ions below 0.5 MeV fell by 40%, reaching minima around 2011.5 that were the lowest measured since mid-2005. During the intensity drop at Voyager 1 the ion energy spectrum evolved to a single power-law with an index -1.5. Similar intensity drops began somewhat earlier at Voyager 2, and the intensity minima of the low-energy ions occurred on 2011.2, one-third of a year earlier than at Voyager 1. In addition, after the ion intensities had recovered at Voyager 2, they were deficient at lower energies compared to the pre-drop levels, causing the energy spectrum to flatten with decreasing energy. During the intensity drop at Voyager 2, ion angular distributions evolved from convective-like, consistent with the measured plasma flow velocity, to azimuthal, more consistent with unidirectional streaming along the mean magnetic field. We will also summarize the heliosheath plasma flow velocity in the R-T (instrument scan) plane that is estimated using angular data from the three lowest energy Voyager 1 LECP ion channels, which cover 40-139 keV. The estimated radial component of flow decreased from about 60 km/s to about 0 km/s at a rate of -19 km/s/yr during 2008.7-2010.3, was consistent with 0 km/s from 2010.3-2011.0, and then went negative, averaging about -13 km

  11. Charged particle radiography.

    PubMed

    Morris, C L; King, N S P; Kwiatkowski, K; Mariam, F G; Merrill, F E; Saunders, A

    2013-04-01

    New applications of charged particle radiography have been developed over the past two decades that extend the range of radiographic techniques providing high-speed sequences of radiographs of thicker objects with higher effective dose than can be obtained with conventional radiographic techniques. In this paper, we review the motivation and the development of flash radiography and in particular, charged particle radiography. PMID:23481477

  12. Charged particle radiography

    NASA Astrophysics Data System (ADS)

    Morris, C. L.; King, N. S. P.; Kwiatkowski, K.; Mariam, F. G.; Merrill, F. E.; Saunders, A.

    2013-04-01

    New applications of charged particle radiography have been developed over the past two decades that extend the range of radiographic techniques providing high-speed sequences of radiographs of thicker objects with higher effective dose than can be obtained with conventional radiographic techniques. In this paper, we review the motivation and the development of flash radiography and in particular, charged particle radiography.

  13. Energy loss of tens keV charged particles traveling in the hot dense carbon plasma

    NASA Astrophysics Data System (ADS)

    Fu, ZhenGuo; Wang, ZhiGang; He, Bin; Li, DaFang; Zhang, Ping

    2016-08-01

    The energy loss of charged particles, including electrons, protons, and α-particles with tens keV initial energy E 0, traveling in the hot dense carbon (C) plasma for densities from 2.281 to 22.81 g/cm3 and temperatures from 400 to 1500 eV is systematically and quantitatively studied by using the dimensional continuation method. The behaviors of different charged particles are readily distinguishable from each other. Firstly, because an ion is thousands times heavier than an electron, the penetration distance of the electron is much longer than that of proton and α-particle traveling in the plasma. Secondly, most energy of electron projectile with E 0 < 100 keV deposits into the electron species of C plasma, while for the cases of proton and α-particle with E 0 < 100 keV, about more than half energy transfers into the ion species of C plasma. A simple decreasing law of the penetration distance as a function of the plasma density is fitted, and different behaviors of each projectile particle can be clearly found from the fitted data. We believe that with the advanced progress of the present experimental technology, the findings shown here could be confirmed in ion-stopping experiments in the near future.

  14. Observation of high iron charge states at low energies in solar energetic particle events

    SciTech Connect

    Guo, Z.; Möbius, E.; Bochsler, P.; Connell, J. J.; Popecki, M. A.; Klecker, B.; Kartavykh, Y. Y.; Mason, G. M.

    2014-04-10

    The ionic charge states of solar energetic particles (SEPs) provide direct information about the source plasma, the acceleration environment, and their transport. Recent studies report that both gradual and impulsive SEP events show mean iron charge states (Q {sub Fe}) ∼ 10-14 at low energies E ≤ 0.1 MeV nuc{sup –1}, consistent with their origin from typical corona material at temperatures 1-2 MK. Observed increases of (Q {sub Fe}) up to 20 at energies 0.1-0.5 MeV nuc{sup –1} in impulsive SEPs are attributed to stripping during acceleration. However, Q {sub Fe} > 16 is occasionally found in the solar wind, particularly coming from active regions, in contrast to the exclusively reported (Q {sub Fe}) ≤ 14 for low energy SEPs. Here we report results from a survey of all 89 SEP events observed with Advanced Composition Explorer Solar Energetic Particle Ionic Charge Analyzer (SEPICA) in 1998-2000 for iron charge states augmented at low energy with Solar and Heliospheric Observatory CELIAS suprathermal time-of-flight (STOF). Nine SEP events with (Q {sub Fe}) ≥ 14 throughout the entire SEPICA and STOF energy range have been identified. Four of the nine events are impulsive events identified through velocity dispersion that are consistent with source temperatures ≥2 MK up to ∼4 MK. The other five events show evidence of interplanetary acceleration. Four of them involve re-acceleration of impulsive material, whose original energy dependent charge states appear re-distributed to varying extent bringing higher charge states to lower energy. One event, which shows flat but elevated (Q {sub Fe}) ∼ 14.2 over the entire energy range, can be associated with interplanetary acceleration of high temperature material. This event may exemplify a rare situation when a second shock plows through high temperature coronal mass ejection material.

  15. Observation of High Iron Charge States at Low Energies in Solar Energetic Particle Events

    NASA Astrophysics Data System (ADS)

    Guo, Z.; Möbius, E.; Klecker, B.; Bochsler, P.; Connell, J. J.; Kartavykh, Y. Y.; Mason, G. M.; Popecki, M. A.

    2014-04-01

    The ionic charge states of solar energetic particles (SEPs) provide direct information about the source plasma, the acceleration environment, and their transport. Recent studies report that both gradual and impulsive SEP events show mean iron charge states langQ Ferang ~ 10-14 at low energies E <= 0.1 MeV nuc-1, consistent with their origin from typical corona material at temperatures 1-2 MK. Observed increases of langQ Ferang up to 20 at energies 0.1-0.5 MeV nuc-1 in impulsive SEPs are attributed to stripping during acceleration. However, Q Fe > 16 is occasionally found in the solar wind, particularly coming from active regions, in contrast to the exclusively reported langQ Ferang <= 14 for low energy SEPs. Here we report results from a survey of all 89 SEP events observed with Advanced Composition Explorer Solar Energetic Particle Ionic Charge Analyzer (SEPICA) in 1998-2000 for iron charge states augmented at low energy with Solar and Heliospheric Observatory CELIAS suprathermal time-of-flight (STOF). Nine SEP events with langQ Ferang >= 14 throughout the entire SEPICA and STOF energy range have been identified. Four of the nine events are impulsive events identified through velocity dispersion that are consistent with source temperatures >=2 MK up to ~4 MK. The other five events show evidence of interplanetary acceleration. Four of them involve re-acceleration of impulsive material, whose original energy dependent charge states appear re-distributed to varying extent bringing higher charge states to lower energy. One event, which shows flat but elevated langQ Ferang ~ 14.2 over the entire energy range, can be associated with interplanetary acceleration of high temperature material. This event may exemplify a rare situation when a second shock plows through high temperature coronal mass ejection material.

  16. Gridless retarding potential analyzer for use in very-low-energy charged particle detection

    NASA Technical Reports Server (NTRS)

    Shyn, T. W.; Sharp, W. E.; Hays, P. B.

    1976-01-01

    The theory of the hyperbolic retarding potential analyzer in the electrostatic mode is developed in detail and verified in the laboratory. A monoenergetic electron beam is used for the laboratory investigation. The analyzer (acronym HARP) has advantages over other conventional electrostatic analyzers; among them are less contact potential influence and high throughput because of the symmetry shape of the analyzer. The most useful application of the HARP is in detecting low-energy charged particles. A sample of low-energy particle data obtained in the earth's ionosphere is given.

  17. Evaluation of the mean energy deposit during the impact of charged particles on liquid water

    NASA Astrophysics Data System (ADS)

    Bernal, M. A.

    2012-04-01

    The DNA strand break yield due to the impact of ionizing particles on living beings is closely related to the number of inelastic events per unit absorbed dose produced by these particles. The higher this number, the higher the probability of causing DNA strand breaks per unit absorbed dose. In a previous work, it was found that the total number of events produced by primary particles and the secondary electrons is almost independent of the type and energy of the incident particle (or LET). This finding could be supported by a quasi-constant mean energy deposit by inelastic event (\\bar{\\varepsilon }). In this work, \\bar{\\varepsilon } was defined and determined for electrons and the non-negative charge states of hydrogen (H0, +) and helium (He0, +, 2 +) species impacting on liquid water. Ionization, excitation and charge transfer (up to two-electron transfers) processes have been included in present calculations. We found that, for liquid water, \\bar{\\varepsilon } is within 13.7 ± 4.1 eV, 14.2 ± 1.7 eV and 13.8 ± 1.4 eV for electrons, hydrogen and helium species, respectively, with impact energies changing over three orders of magnitude. Unlike the mean excitation energy, the mean energy deposit per inelastic event depends not only on the target molecule but also on the projectile features. However, this dependence is relatively weak. This fact supports the quasi-independent number of inelastic events per unit absorbed dose found previously when charged particles impact on matter.

  18. High-dispersion energy analyzer of charged particles in the form of two coaxial cylinders with an end diaphragm

    NASA Astrophysics Data System (ADS)

    Fishkova, T. Ya.

    2012-12-01

    We propose an energy analyzer of charged particles based on the coaxial electrostatic lens that has been studied earlier. The optimal regimes of operation of such an analyzer are determined using numerical simulation by varying four independent parameters. It is found that linear energy dispersion is an order of magnitude higher than the dispersion of widely used energy analyzers of the type of a plane and cylindrical mirrors, as well as a number of other devices for analyzing the energy of charged particles.

  19. Low-energy charged particle environment at Jupiter - A first look

    NASA Technical Reports Server (NTRS)

    Krimigis, S. M.; Bostrom, C. O.; Keath, E. P.; Zwickl, R. D.; Carbary, J. F.; Armstrong, T. P.; Axford, W. I.; Fan, C. Y.; Gloeckler, G.; Lanzerotti, L. J.

    1979-01-01

    Preliminary results of measurements obtained by the low energy charged particle instrument on board the Voyager 1 spacecraft during its traversal of the Jovian magnetosphere are reported. The instrument consists of the low energy particle telescope and the low energy magnetospheric particle analyzer, designed to perform measurements in the inner and outer magnetosphere respectively. Ions and electrons comprising the Jovian magnetosphere were first detected at a distance of about 600 Jupiter radii from the planet, with the first bow shock crossing at 85.6 Jupiter radii. Upon crossing the magnetopause at about 67 Jupiter radii, the flows of electrons and ions were observed to change direction from away from the planet to the corotational direction. The hot plasma near the magnetosphere boundary is comprised predominantly of protons, sulfur and oxygen. Selective particle absorption near the Io flux tube indicates some form of particle deflection by Io. Fluxes in the outbound region were found to be enhanced from 90 to 160 deg longitude, and 5- and 10-hour low energy particle flux periodicities were observed.

  20. Particle-Charge Spectrometer

    NASA Technical Reports Server (NTRS)

    Fuerstenau, Stephen; Wilson, Gregory R.

    2008-01-01

    An instrument for rapidly measuring the electric charges and sizes (from approximately 1 to approximately 100 micrometers) of airborne particles is undergoing development. Conceived for monitoring atmospheric dust particles on Mars, instruments like this one could also be used on Earth to monitor natural and artificial aerosols in diverse indoor and outdoor settings for example, volcanic regions, clean rooms, powder-processing machinery, and spray-coating facilities. The instrument incorporates a commercially available, low-noise, ultrasensitive charge-sensing preamplifier circuit. The input terminal of this circuit--the gate of a field-effect transistor--is connected to a Faraday-cage cylindrical electrode. The charged particles of interest are suspended in air or other suitable gas that is made to flow along the axis of the cylindrical electrode without touching the electrode. The flow can be channeled and generated by any of several alternative means; in the prototype of this instrument, the gas is drawn along a glass capillary tube (see upper part of figure) coaxial with the electrode. The size of a particle affects its rate of acceleration in the flow and thus affects the timing and shape of the corresponding signal peak generated by the charge-sensing amplifier. The charge affects the magnitude (and thus also the shape) of the signal peak. Thus, the signal peak (see figure) conveys information on both the size and electric charge of a sensed particle. In experiments thus far, the instrument has been found to be capable of measuring individual aerosol particle charges of magnitude greater than 350 e (where e is the fundamental unit of electric charge) with a precision of +/- 150 e. The instrument can sample particles at a rate as high as several thousand per second.

  1. An energy- and charge-conserving, implicit, electrostatic particle-in-cell algorithm

    NASA Astrophysics Data System (ADS)

    Chen, G.; Chacón, L.; Barnes, D. C.

    2011-08-01

    This paper discusses a novel fully implicit formulation for a one-dimensional electrostatic particle-in-cell (PIC) plasma simulation approach. Unlike earlier implicit electrostatic PIC approaches (which are based on a linearized Vlasov-Poisson formulation), ours is based on a nonlinearly converged Vlasov-Ampére (VA) model. By iterating particles and fields to a tight nonlinear convergence tolerance, the approach features superior stability and accuracy properties, avoiding most of the accuracy pitfalls in earlier implicit PIC implementations. In particular, the formulation is stable against temporal (Courant-Friedrichs-Lewy) and spatial (aliasing) instabilities. It is charge- and energy-conserving to numerical round-off for arbitrary implicit time steps (unlike the earlier "energy-conserving" explicit PIC formulation, which only conserves energy in the limit of arbitrarily small time steps). While momentum is not exactly conserved, errors are kept small by an adaptive particle sub-stepping orbit integrator, which is instrumental to prevent particle tunneling (a deleterious effect for long-term accuracy). The VA model is orbit-averaged along particle orbits to enforce an energy conservation theorem with particle sub-stepping. As a result, very large time steps, constrained only by the dynamical time scale of interest, are possible without accuracy loss. Algorithmically, the approach features a Jacobian-free Newton-Krylov solver. A main development in this study is the nonlinear elimination of the new-time particle variables (positions and velocities). Such nonlinear elimination, which we term particle enslavement, results in a nonlinear formulation with memory requirements comparable to those of a fluid computation, and affords us substantial freedom in regards to the particle orbit integrator. Numerical examples are presented that demonstrate the advertised properties of the scheme. In particular, long-time ion acoustic wave simulations show that numerical

  2. A bi-directional charged particle telescope to observe flux, energy spectrum and angular distribution of relativistic and non-relativistic particles

    NASA Technical Reports Server (NTRS)

    Verma, S. D.; Bhatnagar, S. P.; Kothari, S. K.

    1985-01-01

    A Charged Particle Telescope (CPT) was designed, fabricated and calibrated to make the following observations: (1) discrimination between various singly charged particles, e.g., electrons, muons and protons, in about 5 to 100 MeV energy range; (2) measurement of the flux and the energy of the charged particles incident to the telescope from two opposite directions and stopping in the telescope, thus obtaining flux and energy spectrum of downward and upward moving charged particles; and (3) measurement of the broad angular distribution of selected particles as a function of azimuthal angle. This telescope can be used to study low energy electron, muon and proton energy spectra. The experiment was flown in a high altitude balloon from Hyderabad, India, in December 1984. This same equipment is also useful in ground level electron, muon spectrum study.

  3. UNIVERSAL BEHAVIOR OF CHARGED PARTICLE PRODUCTION IN HEAVY ION COLLISIONS AT RHIC ENERGIES.

    SciTech Connect

    STEINBERG,P.A.FOR THE PHOBOS COLLABORATION

    2002-07-18

    The PHOBOS experiment at RHIC has measured the multiplicity of primary charged particles as a function of centrality and pseudorapidity in Au+Au collisions at {radical}(s{sub NN}) = 19.6, 130 and 200 GeV. Two kinds of universal behavior are observed in charged particle production in heavy ion collisions. The first is that forward particle production, over a range of energies, follows a universal limiting curve with a non-trivial centrality dependence. The second arises from comparisons with pp/{bar p}p and e{sup +}e{sup -} data. / in nuclear collisions at high energy scales with {radical}s in a similar way as N{sub ch} in e{sup +}e{sup -} collisions and has a very weak centrality dependence. This feature may be related to a reduction in the leading particle effect due to the multiple collisions suffered per participant in heavy ion collisions.

  4. UNIVERSAL BEHAVIOR OF CHARGED PARTICLE PRODUCTION IN HEAVY ION COLLISIONS AT RHIC ENERGIES.

    SciTech Connect

    STEINBERG,P.A.; FOR THE PHOBOS COLLABORATION

    2002-07-18

    The PHOBOS experiment at RHIC has measured the multiplicity of primary charged particles as a function of centrality and pseudorapidity in Au+Au collisions at {radical}(s{sub NN}) = 19.6, 130 and 200 GeV. Two observations indicate universal behavior of charged particle production in heavy ion collisions. The first is that forward particle production, over a range of energies, follows a universal limiting curve with a non-trivial centrality dependence. The second arises from comparisons with pp/{bar p}p and e{sup +}e{sup -} data. / in nuclear collisions at high energy scales with {radical}s in a similar way as N{sub ch} in e{sup +}e{sup -} collisions and has a very weak centrality dependence. These features may be related to a reduction in the leading particle effect due to the multiple collisions suffered per participant in heavy ion collisions.

  5. UNIVERSAL BEHAVIOR OF CHARGED PARTICLE PRODUCTION IN HEAVY ION COLLISIONS AT RHIC ENERGIES.

    SciTech Connect

    STEINBERG,P.A.; FOR THE PHOBOS COLLABORATION

    2002-07-24

    The PHOBOS experiment at RHIC has measured the multiplicity of primary charged particles as a function of centrality and pseudorapidity in Au+Au collisions at {radical}(s{sub NN}) = 19.6, 130 and 200 GeV. Two observations indicate universal behavior of charged particle production in heavy ion collisions. The first is that forward particle production, over a range of energies, follows a universal limiting curve with a non-trivial centrality dependence. The second arises from comparisons with pp/{bar p}p and e{sup +}e{sup -} data. / in nuclear collisions at high energy scales with {radical}s in a similar way as N{sub ch} in e{sup +}e{sup -} collisions and has a very weak centrality dependence. These features may be related to a reduction in the leading particle effect due to the multiple collisions suffered per participant in heavy ion collisions.

  6. Beam energy dependence of pseudorapidity distributions of charged particles produced in relativistic heavy-ion collisions

    NASA Astrophysics Data System (ADS)

    Basu, Sumit; Nayak, Tapan K.; Datta, Kaustuv

    2016-06-01

    Heavy-ion collisions at the Relativistic Heavy Ion Collider at Brookhaven National Laboratory and the Large Hadron Collider at CERN probe matter at extreme conditions of temperature and energy density. Most of the global properties of the collisions can be extracted from the measurements of charged-particle multiplicity and pseudorapidity (η ) distributions. We have shown that the available experimental data on beam energy and centrality dependence of η distributions in heavy-ion (Au +Au or Pb +Pb ) collisions from √{sNN}=7.7 GeV to 2.76 TeV are reasonably well described by the AMPT model, which is used for further exploration. The nature of the η distributions has been described by a double Gaussian function using a set of fit parameters, which exhibit a regular pattern as a function of beam energy. By extrapolating the parameters to a higher energy of √{sNN}=5.02 TeV, we have obtained the charged-particle multiplicity densities, η distributions, and energy densities for various centralities. Incidentally, these results match well with some of the recently published data by the ALICE Collaboration.

  7. Electromagnetic Weibel Instability in Intense Charged Particle Beams with Large Energy Anisotropy

    SciTech Connect

    Edward A. Startsev; Ronald C. Davidson

    2003-10-20

    In plasmas with strongly anisotropic distribution functions, collective instabilities may develop if there is sufficient coupling between the transverse and longitudinal degrees of freedom. Our previous numerical and theoretical studies of intense charged particle beams with large temperature anisotropy [E. A. Startsev, R. C. Davidson and H. Qin, PRSTAB, 6, 084401 (2003); Phys. Plasmas 9, 3138 (2002)] demonstrated that a fast, electrostatic, Harris-like instability develops, and saturates nonlinearly, for sufficiently large temperature anisotropy (T{sub {perpendicular}b}/T{sub {parallel}b} >> 1). The total distribution function after saturation, however, is still far from equipartitioned. In this paper the linearized Vlasov-Maxwell equations are used to investigate detailed properties of the transverse electromagnetic Weibel-type instability for a long charge bunch propagating through a cylindrical pipe of radius r{sub w}. The kinetic stability analysis is carried out for azimuthally symmetric perturbations about a two-temperature thermal equilibrium distribution in the smooth-focusing approximation. The most unstable modes are identified, and their eigenfrequencies, radial mode structure and instability thresholds are determined. The stability analysis shows that, although there is free energy available to drive the electromagnetic Weibel instability, the finite transverse geometry of the charged particle beam introduces a large threshold value for the temperature anisotropy ((T{sub {perpendicular}b}/T{sub {parallel}b}){sup Weibel} >> (T{sub {perpendicular}b}/T{sub {parallel}b}){sup Harris}) below which the instability is absent. Hence, unlike the case of an electrically neutral plasma, the Weibel instability is not expected to play as significant a role in the process of energy isotropization of intense unneutralized charged particle beams as the electrostatic Harris-type instability.

  8. A thin film device as a low energy, high flux charged particle spectrometer

    NASA Astrophysics Data System (ADS)

    Cecil, F. E.; Roy, Brian; Sutton, Christian; Wasinger, Nicole

    2001-01-01

    We are continuing our investigation of the use of stacks of electrically isolated thin metal foils as spectrometers for lost ions from tokamak fusion plasmas. Devices of this type in which the foil thicknesses were a few micrometers were installed on the Joint European Torus during the recent first deuterium-tritium experiment in an effort to observe lost energetic alpha particles. While there was no convincing evidence of lost alpha particles in this experiment, we did observe significant fluxes of low energy (<500 keV) charged particles. In an effort to provide an instrument for the investigation of this phenomenon and of escaping relatively low energy (<100 keV) ions from other fusion plasma devices, we have developed alternative devices with very thin (few hundred nanometers) alternating layers of conductor and insulator. Four such devices have been fabricated and tested for protons with energies between 20 and 160 keV and demonstrated good energy resolution (typically about 10%) for proton bombarding energies between about 40 and 120 keV. One of the devices, consisting of deposited layers of Al, Ti, and SiO2 was operated up to a current density of about 100 m/cm2 at an energy of 100 keV, corresponding to a power volume density of 100 kW/cm3

  9. Search for fractionally charged particles

    SciTech Connect

    Lackner, K.S.; Zweig, G.

    1982-01-01

    Quarks, the constituents of hadrons and fermion fields of quantum chromodynamics, have fractional charges -1/3e and 2/3e. All charges are integral multiples of 1/3e and not e, as was previously believed. Therefore it is natural to ask if isolated particles of fractional charge exist, either as an intrinsic part of matter, or as particles that can be produced at high energy accelerators. This question can only be answered by experiment, and remains interesting even if quantum chromodynamics turns out to be an absolutely confining theory of quarks. For example, small deviations from the standard version of quantum chromodynamics, or the incorporation of quantum chromodynamics into a more comprehensive theory, could require the existence of free fractionally charged particles.

  10. An energy- and charge-conserving, nonlinearly implicit, electromagnetic particle-in-cell algorithm

    NASA Astrophysics Data System (ADS)

    Chen, Guangye; Chacon, Luis; Knoll, Dana; Daughton, William; CoCoMans (LANL) Team

    2013-10-01

    A recent proof-of-principle study proposes a nonlinear electrostatic implicit particle-in-cell (PIC) algorithm in one dimension. The algorithm employs a kinetically enslaved Jacobian-free Newton-Krylov (JFNK) method, and conserves energy and charge to numerical round-off. In this study, we generalize the method to electromagnetic simulations in 1D using the Darwin approximation of Maxwell's equations. An implicit, orbit-averaged central finite difference scheme is applied to both the Darwin field equations and the particle orbit equations to produce a discrete system that remains exactly charge-and energy-conserving. Furthermore, the canonical momentum in any ignorable direction is exactly conserved per particle by appropriate interpolations of the magnetic field. A fluid preconditioner targeting the stiffest electron waves has been developed to accelerate the linear GMRES solver of JFNK. We present 1D numerical experiments (e.g. the Weibel instability, kinetic Alfven wave ion-ion streaming instability, etc.) to demonstrate the accuracy and efficiency of the implicit Darwin PIC algorithm, and the performance of the fluid preconditioner.

  11. Calculations of heat deposition in a target system bombarded by high energy charged particles

    NASA Astrophysics Data System (ADS)

    Nishida, Takahiko; Nakahara, Yasuaki

    1984-09-01

    At the Japan Atomic Energy Research Institute (JAERI), with the use of the Monte Carlo code NMTC/JAERI and the analysis code NMTA, studies have been performed of the feasibility of an emerging new technology such as an accelerator nuclear fuel producer or a radioactive waste transmuter, which utilizes abundant neutrons emitted by the spallation and fission reactions in a proton accelerator target. New subroutines were added to the NMTA code calculating the total heat deposition and the spatial distribution of heat deposition density in a target. A new subroutine is provided also for estimating the mean excitation energy of recoiling residual nuclei after the particle evaporation ceased to occur. The NMTC/JAERI flow for a fission event was also modified. The processes that account for the heat producing energy in the range greater than 15 MeV are mainly (a) ionization loss by charged particles through transport and (b) the kinetic energy of recoil nuclei after intranuclear cascades and fissions. Preliminary calculations of the heat deposition are carried out for small bare targets of Pb, Nat. U and molten salts for some combinations of incident particle energy, beam radius, target material and size. The new computational routines are explained in detail and discussions are done on the calculated results.

  12. Low-energy charged particle environment at jupiter: a first look.

    PubMed

    Krimigis, S M; Armstrong, T P; Axford, W I; Bostrom, C O; Fan, C Y; Gloeckler, G; Lanzerotti, L J; Keath, E P; Zwickl, R D; Carbary, J F; Hamilton, D C

    1979-06-01

    The low-energy charged particle instrument on Voyager was designed to measure the hot plasma (electron and ion energies greater, similar 15 and greater, similar 30 kiloelectron volts, respectively) component of the Jovian magnetosphere. Protons, heavier ions, and electrons at these energies were detected nearly a third of an astronomical unit before encounter with the planet. The hot plasma near the magnetosphere boundary is predominantly composed of protons, oxygen, and sulfur in comparable proportions and a nonthermal power-law tail; its temperature is about 3 x 10(8) K, density about 5 x 10(-3) per cubic centimeter, and energy density comparable to that of the magnetic field. The plasma appears to be corotating throughout the magnetosphere; no hot plasma outflow, as suggested by planetary wind theories, is observed. The main constituents of the energetic particle population ( greater, similar200 kiloelectron volts per nucleon) are protons, helium, oxygen, sulfur, and some sodium observed throughout the outer magnetosphere; it is probable that the sulfur, sodium, and possibly oxygen originate at 1o. Fluxes in the outbound trajectory appear to be enhancedfrom approximately 90 degrees to approximately 130 degrees longitude (System III). Consistent low-energy particle flux periodicities were not observed on the inbound trajectory; both 5-and 10-hour periodicities were observed on the outbound trajectory. Partial absorption of > 10 million electron volts electrons is observed in the vicinity of the Io flux tube.

  13. Numerical studies of the Weibel Instability in Intense Charged Particle Beams with Large Energy Anisotropy

    NASA Astrophysics Data System (ADS)

    Lee, Wei-Li; Startsev, Edward A.; Davidson, Ronald C.

    2004-11-01

    In intense charged particle beams with large temperature anisotropy free energy is available to drive a transverse electromagnetic Weibel-type instability. The finite transverse geometry of the confined beam makes a detailed theoretical investigation difficult. In this paper the newly developed bEASt (beam eigenmode and spectra) code which solves the linearized Vlasov-Maxwell equations is used to investigate the detailed properties of the Weibel instability for a long charge bunch propagating through a cylindrical pipe of radius r_w. The stability analysis is carried out for azimuthally symmetric perturbations about a two-temperature thermal equilibrium distribution in the smooth-focusing approximation. To study the nonlinear stage of the instability, the Darwin model is being developed and incorporated into the Beam Equilibrium Stability and Transport(BEST) code.

  14. Irradiation of Neurons with High-Energy Charged Particles: An In Silico Modeling Approach

    PubMed Central

    Alp, Murat; Parihar, Vipan K.; Limoli, Charles L.; Cucinotta, Francis A.

    2015-01-01

    In this work, a stochastic computational model of microscopic energy deposition events is used to study for the first time damage to irradiated neuronal cells of the mouse hippocampus. An extensive library of radiation tracks for different particle types is created to score energy deposition in small voxels and volume segments describing a neuron’s morphology that later are sampled for given particle fluence or dose. Methods included the construction of in silico mouse hippocampal granule cells from neuromorpho.org with spine and filopodia segments stochastically distributed along the dendritic branches. The model is tested with high-energy 56Fe, 12C, and 1H particles and electrons. Results indicate that the tree-like structure of the neuronal morphology and the microscopic dose deposition of distinct particles may lead to different outcomes when cellular injury is assessed, leading to differences in structural damage for the same absorbed dose. The significance of the microscopic dose in neuron components is to introduce specific local and global modes of cellular injury that likely contribute to spine, filopodia, and dendrite pruning, impacting cognition and possibly the collapse of the neuron. Results show that the heterogeneity of heavy particle tracks at low doses, compared to the more uniform dose distribution of electrons, juxtaposed with neuron morphology make it necessary to model the spatial dose painting for specific neuronal components. Going forward, this work can directly support the development of biophysical models of the modifications of spine and dendritic morphology observed after low dose charged particle irradiation by providing accurate descriptions of the underlying physical insults to complex neuron structures at the nano-meter scale. PMID:26252394

  15. Low-Energy Charged Particles in Saturn's Magnetosphere: Results from Voyager 1.

    PubMed

    Krimigis, S M; Armstrong, T P; Axford, W I; Bostrom, C O; Gloeckler, G; Keath, E P; Lanzerotti, L J; Carbary, J F; Hamilton, D C; Roelof, E C

    1981-04-10

    The low-energy charged particle instrument on Voyager 1 measured low-energy electrons and ions (energies >/= 26 and >/= 40 kiloelectron volts, respectively) in Saturn's magnetosphere. The first-order ion anisotropies on the dayside are generally in the corotation direction with the amplitude decreasing with decreasing distance to the planet. The ion pitch-angle distributions generally peak at 90 degrees , whereas the electron distributions tend to have field-aligned bidirectional maxima outside the L shell of Rhea. A large decrease in particle fluxes is seen near the L shell of Titan, while selective particle absorption (least affecting the lowest energy ions) is observed at the L shells of Rhea, Dione, and Tethys. The phase space density of ions with values of the first invariant in the range approximately 300 to 1000 million electron volts per gauss is consistent with a source in the outer magnetosphere. The ion population at higher energies (>/= 200 kiloelectron volts per nucleon) consists primarily of protons, molecular hydrogen, and helium. Spectra of all ion species exhibit an energy cutoff at energies >/= 2 million electron volts. The proton-to-helium ratio at equal energy per nucleon is larger (up to approximately 5 x 10(3)) than seen in other magnetospheres and is consistent with a local (nonsolar wind) proton source. In contrast to the magnetospheres of Jupiter and Earth, there are no lobe regions essentially devoid of particles in Saturn's nighttime magnetosphere. Electron pitch-angle distributions are generally bidirectional andfield-aligned, indicating closed field lines at high latitudes. Ions in this region are generally moving toward Saturn, while in the magnetosheath they exhibit strong antisunward streaming which is inconsistent with purely convective flows. Fluxes of magnetospheric ions downstream from the bow shock are present over distances >/= 200 Saturn radii from the planet. Novel features identified in the Saturnian magnetosphere include a

  16. Regular threshold-energy increase with charge for neutral-particle emission in collisions of electrons with oligonucleotide anions.

    PubMed

    Tanabe, T; Noda, K; Saito, M; Starikov, E B; Tateno, M

    2004-07-23

    Electron-DNA anion collisions were studied using an electrostatic storage ring with a merging electron-beam technique. The rate of neutral particles emitted in collisions started to increase from definite threshold energies, which increased regularly with ion charges in steps of about 10 eV. These threshold energies were almost independent of the length and sequence of DNA, but depended strongly on the ion charges. Neutral particles came from breaks of DNAs, rather than electron detachment. The step of the threshold energy increase approximately agreed with the plasmon excitation energy. It is deduced that plasmon excitation is closely related to the reaction mechanism.

  17. Energy loss rate of a charged particle in HgTe/(HgTe, CdTe) quantum wells

    SciTech Connect

    Chen, Qinjun; Sin Ang, Yee; Wang, Xiaolin; Lewis, R. A.; Zhang, Chao

    2013-11-04

    The energy loss rate (ELR) of a charged particle in a HgTe/(HgTe, CdTe) quantum well is investigated. We consider scattering of a charged particle by the bulk insulating states in this type of topological insulator. It is found that the ELR characteristics due to the intraband excitation have a linear energy dependence while those due to interband excitation depend on the energy exponentially. An interesting quantitative result is that for a large range of the incident energy, the mean inelastic scattering rate is around a few terahertz.

  18. Electrodynamics of massless charged particles

    SciTech Connect

    Lechner, Kurt

    2015-02-15

    We derive the classical dynamics of massless charged particles in a rigorous way from first principles. Since due to ultraviolet divergences this dynamics does not follow from an action principle, we rely on (a) Maxwell’s equations, (b) Lorentz- and reparameterization-invariance, and (c) local conservation of energy and momentum. Despite the presence of pronounced singularities of the electromagnetic field along Dirac-like strings, we give a constructive proof of the existence of a unique distribution-valued energy-momentum tensor. Its conservation requires the particles to obey standard Lorentz equations and they experience, hence, no radiation reaction. Correspondingly, the dynamics of interacting classical massless charged particles can be consistently defined, although they do not emit bremsstrahlung end experience no self-interaction.

  19. Cellular and molecular analysis of mutagenesis induced by charged particles of defined linear energy transfer

    NASA Technical Reports Server (NTRS)

    Zhu, L. X.; Waldren, C. A.; Vannias, D.; Hei, T. K.; Chatterjee, A. (Principal Investigator)

    1996-01-01

    Mutation induction by charged particles of defined linear energy transfer (LET) and gamma rays was scored using human-hamster hybrid AL cells. The LET values for charged particles accelerated at the Radiological Research Accelerator Facility ranged from 10 keV/microm protons to 150 keV/microm 4He ions. The induced mutant fractions at both the S1 and HGPRT loci were dependent on the dose and LET. In addition, for each dose examined, the mutant yield at the S1 locus was 30-60 fold higher than at the corresponding HGPRT locus. To determine whether the mutation spectrum was comparably dependent on dose and LET, independent S1- and HGPRT- mutants induced by 150 keV/microm 4He ions and gamma rays were isolated, and their DNA was analyzed by both Southern blotting and multiplex PCR methods. While the majority of radiation-induced mutants showed deletions of varying sizes, the relative percentage of large deletions was found to be related to both the dose and LET of the radiation examined. Using a mutation system that can detect multilocus changes, results of the present study show that radiation-induced chromosomal loss can be in the millions of base pairs.

  20. Evidence for MeV-particle emission from Ti charged with low-energy deuterium ions. Final report

    SciTech Connect

    Chambers, G.P.; Hubler, G.K.; Grabowski, K.S.

    1991-12-18

    Thin titanium films have been bombarded with low energy (350 eV) deuterium ions at high current density (0.2-0.4 mA.cm2) to investigate the reported occurrence of nuclear reactions at ambient temperatures in deuterium charged metals. A silicon charged particle detector was used to search for charged particles produced by such reactions. Evidence is reported for the detection of hydrogen isotopes with 5 MeV energy at a rate of 10-16 events/deuteron pair/s. Low energy deuterium (350 eV) ions produced by an ECR microwave source impinge normally on a thin metal film in vacuum, while a Si particle detector placed directly behind the film detects particle emission. The advantages of this method are rapid and efficient deuterium charging of any material (including insulators), high particle detection efficiency and sensitivity (low background), and the ability to measure the particle energy and determine the particle type. Titanium was chosen as the target because previous work by Jones had shown neutron emission and because Ti retains more hydrogen near room temperature than does PD.

  1. [Experimental studies of the relative biological effectiveness of accelerated charged particles varying in energy].

    PubMed

    Fedorenko, B S; Petrov, V M; Smirnova, O A; Vorozhtsova, S V; Abrosimova, A N

    2006-01-01

    Experimental results and literary data were analyzed for the relative biological effectiveness of heavy charged particles in a broad range of energy and LET to cells of humans and other mammals in culture, whole body of laboratory animals, microorganisms, bacteriophages, and plants. Analyzed were data obtained with the use of a diversity of tests of acute and delayed lesions induced by ionizing radiation, cancers and cataracts, specifically. Non-parametric methods are applied in parallel to the classic method of calculating the coefficients of relative biological effectiveness by correlating the equal-effective doses of the standard and a given radiation. Consideration is given to factors that may modify RBE values estimated for different types of radiation. PMID:17193971

  2. Energy exchange between a laser beam and charged particles using inverse transition radiation and method for its use

    DOEpatents

    Kimura, Wayne D.; Romea, Richard D.; Steinhauer, Loren C.

    1998-01-01

    A method and apparatus for exchanging energy between relativistic charged particles and laser radiation using inverse diffraction radiation or inverse transition radiation. The beam of laser light is directed onto a particle beam by means of two optical elements which have apertures or foils through which the particle beam passes. The two apertures or foils are spaced by a predetermined distance of separation and the angle of interaction between the laser beam and the particle beam is set at a specific angle. The separation and angle are a function of the wavelength of the laser light and the relativistic energy of the particle beam. In a diffraction embodiment, the interaction between the laser and particle beams is determined by the diffraction effect due to the apertures in the optical elements. In a transition embodiment, the interaction between the laser and particle beams is determined by the transition effect due to pieces of foil placed in the particle beam path.

  3. The knee in the cosmic ray energy spectrum from the simultaneous EAS charged particles and muon density spectra

    NASA Astrophysics Data System (ADS)

    Bijay, Biplab; Banik, Prabir; Bhadra, Arunava

    2016-09-01

    In this work we examine with the help of Monte Carlo simulation whether a consistent primary energy spectrum of cosmic rays emerges from both the experimentally observed total charged particles and muon size spectra of cosmic ray extensive air showers considering primary composition may or may not change beyond the knee of the energy spectrum. It is found that EAS-TOP observations consistently infer a knee in the primary energy spectrum provided the primary is pure unchanging iron whereas no consistent primary spectrum emerges from simultaneous use of the KASCADE observed total charged particle and muon spectra. However, it is also found that when primary composition changes across the knee the estimation of spectral index of total charged particle spectrum is quite tricky, depends on the choice of selection of points near the knee in the size spectrum.

  4. Direct electron-pair production by high energy heavy charged particles

    NASA Technical Reports Server (NTRS)

    Takahashi, Y.; Gregory, J. C.; Hayashi, T.; Dong, B. L.

    1989-01-01

    Direct electron pain production via virtual photons by moving charged particles is a unique electro-magnetic process having a substantial dependence on energy. Most electro-magnetic processes, including transition radiation, cease to be sensitive to the incident energy above 10 TeV/AMU. Thus, it is expected, that upon establishment of cross section and detection efficiency of this process, it may provide a new energy measuring technique above 10 TeV/AMU. Three accelerator exposures of emulsion chambers designed for measurements of direct electron-pains were performed. The objectives of the investigation were to provide the fundamental cross-section data in emulsion stacks to find the best-fit theoretical model, and to provide a calibration of measurements of direct electron-pairs in emulsion chamber configurations. This paper reports the design of the emulsion chambers, accelerator experiments, microscope measurements, and related considerations for future improvements of the measurements, and for possible applications to high energy cosmic ray experiments. Also discussed are the results from scanning 56m of emulsion tracks at 1200x magnification so that scanning efficiency is optimized. Measurements of the delta-ray range spectrum were also performed for much shorter track lengths, but with sufficiently large statistics in the number of measured delta-rays.

  5. Apolipoprotein E expression and behavioral toxicity of high charge, high energy (HZE) particle radiation

    NASA Technical Reports Server (NTRS)

    Higuchi, Yoshinori; Nelson, Gregory A.; Vazquez, Marcelo; Laskowitz, Daniel T.; Slater, James M.; Pearlstein, Robert D.

    2002-01-01

    Apolipoprotein E (apoE) is a lipid binding protein that plays an important role in tissue repair following brain injury. In the present studies, we have investigated whether apoE affects the behavioral toxicity of high charge, high energy (HZE) particle radiation. METHODS: Sixteen male apoE knockout (KO) mice and sixteen genetically matched wild-type (WT) C57BL mice were used in this experiment. Half of the KO and half of the WT animals were irradiated with 600 MeV/amu iron particles (2 Gy whole body). The effect of irradiation on motor coordination and stamina (Rotarod test), exploratory behavior (open field test), and spatial working and reference memory (Morris water maze) was assessed. ROTAROD TEST: Performance was adversely affected by radiation exposure in both KO and WT groups at 30 d after irradiation. By 60 d after radiation, the radiation effect was lost in WT, but still apparent in irradiated KO mice. OPEN FIELD TEST: Radiation reduced open field exploratory activity 14, 28, 56, 84, and 168 d after irradiation of KO mice, but had no effect on WT mice. MORRIS WATER MAZE: Radiation adversely affected spatial working memory in the KO mice, but had no discernible effect in the WT mice as assessed 180 d after irradiation. In contrast, irradiated WT mice showed marked impairment of spatial reference memory in comparison to non-irradiated mice, while no effect of radiation was observed in KO mice. CONCLUSIONS: These studies show that apoE expression influences the behavioral toxicity of HZE particle radiation and suggest that apoE plays a role in the repair/recovery from radiation injury of the CNS. ApoE deficiency may exacerbate the previously reported effects of HZE particle radiation in accelerating the brain aging process.

  6. High throughput on-chip analysis of high-energy charged particle tracks using lensfree imaging

    SciTech Connect

    Luo, Wei; Shabbir, Faizan; Gong, Chao; Gulec, Cagatay; Pigeon, Jeremy; Shaw, Jessica; Greenbaum, Alon; Tochitsky, Sergei; Joshi, Chandrashekhar; Ozcan, Aydogan

    2015-04-13

    We demonstrate a high-throughput charged particle analysis platform, which is based on lensfree on-chip microscopy for rapid ion track analysis using allyl diglycol carbonate, i.e., CR-39 plastic polymer as the sensing medium. By adopting a wide-area opto-electronic image sensor together with a source-shifting based pixel super-resolution technique, a large CR-39 sample volume (i.e., 4 cm × 4 cm × 0.1 cm) can be imaged in less than 1 min using a compact lensfree on-chip microscope, which detects partially coherent in-line holograms of the ion tracks recorded within the CR-39 detector. After the image capture, using highly parallelized reconstruction and ion track analysis algorithms running on graphics processing units, we reconstruct and analyze the entire volume of a CR-39 detector within ∼1.5 min. This significant reduction in the entire imaging and ion track analysis time not only increases our throughput but also allows us to perform time-resolved analysis of the etching process to monitor and optimize the growth of ion tracks during etching. This computational lensfree imaging platform can provide a much higher throughput and more cost-effective alternative to traditional lens-based scanning optical microscopes for ion track analysis using CR-39 and other passive high energy particle detectors.

  7. Scalar self-energy for a charged particle in global monopole spacetime with a spherical boundary

    NASA Astrophysics Data System (ADS)

    Bezerra de Mello, E. R.; Saharian, A. A.

    2012-07-01

    We analyze combined effects of the geometry produced by a global monopole and a concentric spherical boundary on the self-energy of a point-like scalar charged test particle at rest. We assume that the boundary is outside the monopole’s core with a general spherically symmetric inner structure. An important quantity to this analysis is the three-dimensional Green function associated with this system. For both Dirichlet and Neumann boundary conditions obeyed by the scalar field on the sphere, the Green function presents a structure that contains contributions due to the background geometry of the spacetime and the boundary. Consequently, the corresponding induced scalar self-energy also presents a similar structure. For points near the sphere, the boundary-induced part dominates and the self-force is repulsive/attractive with respect to the boundary for Dirichlet/Neumann boundary condition. In the region outside the sphere at large distances from it, the boundary-free part in the self-energy dominates and the corresponding self-force can be either attractive or repulsive with dependence of the curvature coupling parameter for scalar field. In particular, for the minimal coupling we show the presence of a stable equilibrium point for the Dirichlet boundary condition. In the region inside the sphere, the nature of the self-force depends on the specific model for the monopole’s core. As illustrations of the general procedure adopted, we shall consider two distinct models, namely the flower-pot and the ballpoint-pen ones.

  8. A Closed Parameterization of DNA–Damage by Charged Particles, as a Function of Energy — A Geometrical Approach

    PubMed Central

    Van den Heuvel, Frank

    2014-01-01

    Purpose To present a closed formalism calculating charged particle radiation damage induced in DNA. The formalism is valid for all types of charged particles and due to its closed nature is suited to provide fast conversion of dose to DNA-damage. Methods The induction of double strand breaks in DNA–strings residing in irradiated cells is quantified using a single particle model. This leads to a proposal to use the cumulative Cauchy distribution to express the mix of high and low LET type damage probability generated by a single particle. A microscopic phenomenological Monte Carlo code is used to fit the parameters of the model as a function of kinetic energy related to the damage to a DNA molecule embedded in a cell. The model is applied for four particles: electrons, protons, alpha–particles, and carbon ions. A geometric interpretation of this observation using the impact ionization mean free path as a quantifier, allows extension of the model to very low energies. Results The mathematical expression describes the model adequately using a chi–square test (). This applies to all particle types with an almost perfect fit for protons, while the other particles seem to result in some discrepancies at very low energies. The implementation calculating a strict version of the RBE based on complex damage alone is corroborated by experimental data from the measured RBE. The geometric interpretation generates a unique dimensionless parameter for each type of charged particle. In addition, it predicts a distribution of DNA damage which is different from the current models. PMID:25340636

  9. Fractionally Charged Zero-Energy Single-Particle Excitations in a Driven Fermi Sea

    NASA Astrophysics Data System (ADS)

    Moskalets, Michael

    2016-07-01

    A voltage pulse of a Lorentzian shape carrying half of the flux quantum excites out of a zero-temperature Fermi sea an electron in a mixed state, which looks like a quasiparticle with an effectively fractional charge e /2 . A prominent feature of such an excitation is a narrow peak in the energy distribution function lying exactly at the Fermi energy μ . Another spectacular feature is that the distribution function has symmetric tails around μ , which results in a zero-energy excitation. This sounds improbable since at zero temperature all available states below μ are fully occupied. The resolution lies in the fact that such a voltage pulse also excites electron-hole pairs, which free some space below μ and thus allow a zero-energy quasiparticle to exist. I discuss also how to address separately electron-hole pairs and a fractionally charged zero-energy excitation in an experiment.

  10. CHARGE-EXCHANGE LIMITS ON LOW-ENERGY {alpha}-PARTICLE FLUXES IN SOLAR FLARES

    SciTech Connect

    Hudson, H. S.; Fletcher, L.; MacKinnon, A. L.; Woods, T. N.

    2012-06-20

    This paper reports on a search for flare emission via charge-exchange radiation in the wings of the Ly{alpha} line of He II at 304 A, as originally suggested for hydrogen by Orrall and Zirker. Via this mechanism a primary {alpha} particle that penetrates into the neutral chromosphere can pick up an atomic electron and emit in the He II bound-bound spectrum before it stops. The Extreme-ultraviolet Variability Experiment on board the Solar Dynamics Observatory gives us our first chance to search for this effect systematically. The Orrall-Zirker mechanism has great importance for flare physics because of the essential roles that particle acceleration plays; this mechanism is one of the few proposed that would allow remote sensing of primary accelerated particles below a few MeV nucleon{sup -1}. We study 10 events in total, including the {gamma}-ray events SOL2010-06-12 (M2.0) and SOL2011-02-24 (M3.5) (the latter a limb flare), seven X-class flares, and one prominent M-class event that produced solar energetic particles. The absence of charge-exchange line wings may point to a need for more complete theoretical work. Some of the events do have broadband signatures, which could correspond to continua from other origins, but these do not have the spectral signatures expected from the Orrall-Zirker mechanism.

  11. Gated charged-particle trap

    DOEpatents

    Benner, W. Henry

    1999-01-01

    The design and operation of a new type of charged-particle trap provides simultaneous measurements of mass, charge, and velocity of large electrospray ions. The trap consists of a detector tube mounted between two sets of center-bored trapping plates. Voltages applied to the trapping plates define symmetrically-opposing potential valleys which guide axially-injected ions to cycle back and forth through the charge-detection tube. A low noise charge-sensitive amplifier, connected to the tube, reproduces the image charge of individual ions as they pass through the detector tube. Ion mass is calculated from measurement of ion charge and velocity following each passage through the detector.

  12. Fog dispersion. [charged particle technique

    NASA Technical Reports Server (NTRS)

    Christensen, L. S.; Frost, W.

    1980-01-01

    The concept of using the charged particle technique to disperse warm fog at airports is investigated and compared with other techniques. The charged particle technique shows potential for warm fog dispersal, but experimental verification of several significant parameters, such as particle mobility and charge density, is needed. Seeding and helicopter downwash techniques are also effective for warm fog disperals, but presently are not believed to be viable techniques for routine airport operations. Thermal systems are currently used at a few overseas airports; however, they are expensive and pose potential environmental problems.

  13. Energy dependence of the transverse momentum distributions of charged particles in pp collisions measured by ALICE

    NASA Astrophysics Data System (ADS)

    Abelev, B.; Adam, J.; Adamová, D.; Adare, A. M.; Aggarwal, M. M.; Aglieri Rinella, G.; Agnello, M.; Agocs, A. G.; Agostinelli, A.; Ahammed, Z.; Ahmad, N.; Ahmad Masoodi, A.; Ahmed, I.; Ahn, S. A.; Ahn, S. U.; Aimo, I.; Aiola, S.; Ajaz, M.; Akindinov, A.; Aleksandrov, D.; Alessandro, B.; Alexandre, D.; Alici, A.; Alkin, A.; Alme, J.; Alt, T.; Altini, V.; Altinpinar, S.; Altsybeev, I.; Alves Garcia Prado, C.; Andrei, C.; Andronic, A.; Anguelov, V.; Anielski, J.; Antičić, T.; Antinori, F.; Antonioli, P.; Aphecetche, L.; Appelshäuser, H.; Arbor, N.; Arcelli, S.; Armesto, N.; Arnaldi, R.; Aronsson, T.; Arsene, I. C.; Arslandok, M.; Augustinus, A.; Averbeck, R.; Awes, T. C.; Äystö, J.; Azmi, M. D.; Bach, M.; Badalà, A.; Baek, Y. W.; Bailhache, R.; Bala, R.; Baldisseri, A.; Baltasar Dos Santos Pedrosa, F.; Bán, J.; Baral, R. C.; Barbera, R.; Barile, F.; Barnaföldi, G. G.; Barnby, L. S.; Barret, V.; Bartke, J.; Basile, M.; Bastid, N.; Basu, S.; Bathen, B.; Batigne, G.; Batyunya, B.; Batzing, P. C.; Baumann, C.; Bearden, I. G.; Beck, H.; Bedda, C.; Behera, N. K.; Belikov, I.; Bellini, F.; Bellwied, R.; Belmont-Moreno, E.; Bencedi, G.; Beole, S.; Berceanu, I.; Bercuci, A.; Berdnikov, Y.; Berenyi, D.; Bergognon, A. A. E.; Bertens, R. A.; Berzano, D.; Betev, L.; Bhasin, A.; Bhati, A. K.; Bhom, J.; Bianchi, L.; Bianchi, N.; Bianchin, C.; Bielčík, J.; Bielčíková, J.; Bilandzic, A.; Bjelogrlic, S.; Blanco, F.; Blanco, F.; Blau, D.; Blume, C.; Bock, F.; Bogdanov, A.; Bøggild, H.; Bogolyubsky, M.; Boldizsár, L.; Bombara, M.; Book, J.; Borel, H.; Borissov, A.; Bornschein, J.; Botje, M.; Botta, E.; Böttger, S.; Braidot, E.; Braun-Munzinger, P.; Bregant, M.; Breitner, T.; Broker, T. A.; Browning, T. A.; Broz, M.; Brun, R.; Bruna, E.; Bruno, G. E.; Budnikov, D.; Buesching, H.; Bufalino, S.; Buncic, P.; Busch, O.; Buthelezi, Z.; Caffarri, D.; Cai, X.; Caines, H.; Caliva, A.; Calvo Villar, E.; Camerini, P.; Canoa Roman, V.; Cara Romeo, G.; Carena, F.; Carena, W.; Carminati, F.; Casanova Díaz, A.; Castillo Castellanos, J.; Casula, E. A. R.; Catanescu, V.; Cavicchioli, C.; Ceballos Sanchez, C.; Cepila, J.; Cerello, P.; Chang, B.; Chapeland, S.; Charvet, J. L.; Chattopadhyay, S.; Chattopadhyay, S.; Cherney, M.; Cheshkov, C.; Cheynis, B.; Chibante Barroso, V.; Chinellato, D. D.; Chochula, P.; Chojnacki, M.; Choudhury, S.; Christakoglou, P.; Christensen, C. H.; Christiansen, P.; Chujo, T.; Chung, S. U.; Cicalo, C.; Cifarelli, L.; Cindolo, F.; Cleymans, J.; Colamaria, F.; Colella, D.; Collu, A.; Colocci, M.; Conesa Balbastre, G.; Conesa del Valle, Z.; Connors, M. E.; Contin, G.; Contreras, J. G.; Cormier, T. M.; Corrales Morales, Y.; Cortese, P.; Cortés Maldonado, I.; Cosentino, M. R.; Costa, F.; Crochet, P.; Cruz Albino, R.; Cuautle, E.; Cunqueiro, L.; Dainese, A.; Dang, R.; Danu, A.; Das, K.; Das, D.; Das, I.; Dash, A.; Dash, S.; De, S.; Delagrange, H.; Deloff, A.; Dénes, E.; Deppman, A.; de Barros, G. O. V.; De Caro, A.; de Cataldo, G.; de Cuveland, J.; De Falco, A.; De Gruttola, D.; De Marco, N.; De Pasquale, S.; de Rooij, R.; Diaz Corchero, M. A.; Dietel, T.; Divià, R.; Di Bari, D.; Di Giglio, C.; Di Liberto, S.; Di Mauro, A.; Di Nezza, P.; Djuvsland, Ø.; Dobrin, A.; Dobrowolski, T.; Dönigus, B.; Dordic, O.; Dubey, A. K.; Dubla, A.; Ducroux, L.; Dupieux, P.; Dutta Majumdar, A. K.; D Erasmo, G.; Elia, D.; Emschermann, D.; Engel, H.; Erazmus, B.; Erdal, H. A.; Eschweiler, D.; Espagnon, B.; Estienne, M.; Esumi, S.; Evans, D.; Evdokimov, S.; Eyyubova, G.; Fabris, D.; Faivre, J.; Falchieri, D.; Fantoni, A.; Fasel, M.; Fehlker, D.; Feldkamp, L.; Felea, D.; Feliciello, A.; Feofilov, G.; Fernández Téllez, A.; Ferreiro, E. G.; Ferretti, A.; Festanti, A.; Figiel, J.; Figueredo, M. A. S.; Filchagin, S.; Finogeev, D.; Fionda, F. M.; Fiore, E. M.; Floratos, E.; Floris, M.; Foertsch, S.; Foka, P.; Fokin, S.; Fragiacomo, E.; Francescon, A.; Frankenfeld, U.; Fuchs, U.; Furget, C.; Fusco Girard, M.; Gaardhøje, J. J.; Gagliardi, M.; Gago, A.; Gallio, M.; Gangadharan, D. R.; Ganoti, P.; Garabatos, C.; Garcia-Solis, E.; Gargiulo, C.; Garishvili, I.; Gerhard, J.; Germain, M.; Gheata, A.; Gheata, M.; Ghidini, B.; Ghosh, P.; Gianotti, P.; Giubellino, P.; Gladysz-Dziadus, E.; Glässel, P.; Goerlich, L.; Gomez, R.; González-Zamora, P.; Gorbunov, S.; Gotovac, S.; Graczykowski, L. K.; Grajcarek, R.; Grelli, A.; Grigoras, C.; Grigoras, A.; Grigoriev, V.; Grigoryan, A.; Grigoryan, S.; Grinyov, B.; Grion, N.; Grosse-Oetringhaus, J. F.; Grossiord, J.-Y.; Grosso, R.; Guber, F.; Guernane, R.; Guerzoni, B.; Guilbaud, M.; Gulbrandsen, K.; Gulkanyan, H.; Gunji, T.; Gupta, A.; Gupta, R.; Khan, K. H.; Haake, R.; Haaland, Ø.; Hadjidakis, C.; Haiduc, M.; Hamagaki, H.; Hamar, G.; Hanratty, L. D.; Hansen, A.; Harris, J. W.; Harton, A.; Hatzifotiadou, D.; Hayashi, S.; Hayrapetyan, A.; Heckel, S. T.; Heide, M.; Helstrup, H.; Herghelegiu, A.; Herrera Corral, G.; Herrmann, N.; Hess, B. A.; Hetland, K. F.; Hicks, B.; Hippolyte, B.; Hori, Y.; Hristov, P.; Hřivnáčová, I.; Huang, M.; Humanic, T. J.; Hutter, D.; Hwang, D. S.; Ichou, R.; Ilkaev, R.; Ilkiv, I.; Inaba, M.; Incani, E.; Innocenti, G. M.; Ionita, C.; Ippolitov, M.; Irfan, M.; Ivanov, V.; Ivanov, M.; Ivanytskyi, O.; Jachołkowski, A.; Jahnke, C.; Jang, H. J.; Janik, M. A.; Jayarathna, P. H. S. Y.; Jena, S.; Jimenez Bustamante, R. T.; Jones, P. G.; Jung, H.; Jusko, A.; Kalcher, S.; Kaliňák, P.; Kalliokoski, T.; Kalweit, A.; Kang, J. H.; Kaplin, V.; Kar, S.; Karasu Uysal, A.; Karavichev, O.; Karavicheva, T.; Karpechev, E.; Kazantsev, A.; Kebschull, U.; Keidel, R.; Ketzer, B.; Khan, S. A.; Khan, M. M.; Khan, P.; Khanzadeev, A.; Kharlov, Y.; Kileng, B.; Kim, S.; Kim, D. W.; Kim, D. J.; Kim, B.; Kim, T.; Kim, M.; Kim, M.; Kim, J. S.; Kirsch, S.; Kisel, I.; Kiselev, S.; Kisiel, A.; Kiss, G.; Klay, J. L.; Klein, J.; Klein-Bösing, C.; Kluge, A.; Knichel, M. L.; Knospe, A. G.; Köhler, M. K.; Kollegger, T.; Kolojvari, A.; Kondratiev, V.; Kondratyeva, N.; Konevskikh, A.; Kovalenko, V.; Kowalski, M.; Kox, S.; Koyithatta Meethaleveedu, G.; Kral, J.; Králik, I.; Kramer, F.; Kravčáková, A.; Krelina, M.; Kretz, M.; Krivda, M.; Krizek, F.; Krus, M.; Kryshen, E.; Krzewicki, M.; Kucera, V.; Kucheriaev, Y.; Kugathasan, T.; Kuhn, C.; Kuijer, P. G.; Kulakov, I.; Kumar, J.; Kurashvili, P.; Kurepin, A. B.; Kurepin, A.; Kuryakin, A.; Kushpil, S.; Kushpil, V.; Kweon, M. J.; Kwon, Y.; Ladrón de Guevara, P.; Lagana Fernandes, C.; Lakomov, I.; Langoy, R.; Lara, C.; Lardeux, A.; La Pointe, S. L.; La Rocca, P.; Lea, R.; Lechman, M.; Lee, S. C.; Lee, G. R.; Legrand, I.; Lehnert, J.; Lemmon, R. C.; Lenhardt, M.; Lenti, V.; León Monzón, I.; Lévai, P.; Li, S.; Lien, J.; Lietava, R.; Lindal, S.; Lindenstruth, V.; Lippmann, C.; Lisa, M. A.; Ljunggren, H. M.; Lodato, D. F.; Loenne, P. I.; Loggins, V. R.; Loginov, V.; Lohner, D.; Loizides, C.; Loo, K. K.; Lopez, X.; López Torres, E.; Løvhøiden, G.; Lu, X.-G.; Luettig, P.; Lunardon, M.; Luo, J.; Luparello, G.; Luzzi, C.; Jacobs, P. M.; Ma, R.; Maevskaya, A.; Mager, M.; Mahapatra, D. P.; Maire, A.; Malaev, M.; Maldonado Cervantes, I.; Malinina, L.; Mal'Kevich, D.; Malzacher, P.; Mamonov, A.; Manceau, L.; Manko, V.; Manso, F.; Manzari, V.; Marchisone, M.; Mareš, J.; Margagliotti, G. V.; Margotti, A.; Marín, A.; Markert, C.; Marquard, M.; Martashvili, I.; Martin, N. A.; Martinengo, P.; Martínez, M. I.; Martínez García, G.; Martin Blanco, J.; Martynov, Y.; Mas, A.; Masciocchi, S.; Masera, M.; Masoni, A.; Massacrier, L.; Mastroserio, A.; Matyja, A.; Mazer, J.; Mazumder, R.; Mazzoni, M. A.; Meddi, F.; Menchaca-Rocha, A.; Mercado Pérez, J.; Meres, M.; Miake, Y.; Mikhaylov, K.; Milano, L.; Milosevic, J.; Mischke, A.; Mishra, A. N.; Miśkowiec, D.; Mitu, C.; Mlynarz, J.; Mohanty, B.; Molnar, L.; Montaño Zetina, L.; Monteno, M.; Montes, E.; Moon, T.; Morando, M.; Moreira De Godoy, D. A.; Moretto, S.; Morreale, A.; Morsch, A.; Muccifora, V.; Mudnic, E.; Muhuri, S.; Mukherjee, M.; Müller, H.; Munhoz, M. G.; Murray, S.; Musa, L.; Nandi, B. K.; Nania, R.; Nappi, E.; Nattrass, C.; Nayak, T. K.; Nazarenko, S.; Nedosekin, A.; Nicassio, M.; Niculescu, M.; Nielsen, B. S.; Nikolaev, S.; Nikulin, S.; Nikulin, V.; Nilsen, B. S.; Nilsson, M. S.; Noferini, F.; Nomokonov, P.; Nooren, G.; Nyanin, A.; Nyatha, A.; Nystrand, J.; Oeschler, H.; Oh, S. K.; Oh, S.; Olah, L.; Oleniacz, J.; Oliveira Da Silva, A. C.; Onderwaater, J.; Oppedisano, C.; Ortiz Velasquez, A.; Oskarsson, A.; Otwinowski, J.; Oyama, K.; Pachmayer, Y.; Pachr, M.; Pagano, P.; Paić, G.; Painke, F.; Pajares, C.; Pal, S. K.; Palaha, A.; Palmeri, A.; Papikyan, V.; Pappalardo, G. S.; Park, W. J.; Passfeld, A.; Patalakha, D. I.; Paticchio, V.; Paul, B.; Pawlak, T.; Peitzmann, T.; Pereira Da Costa, H.; Pereira De Oliveira Filho, E.; Peresunko, D.; Pérez Lara, C. E.; Perrino, D.; Peryt, W.; Pesci, A.; Pestov, Y.; Petráček, V.; Petran, M.; Petris, M.; Petrov, P.; Petrovici, M.; Petta, C.; Piano, S.; Pikna, M.; Pillot, P.; Pinazza, O.; Pinsky, L.; Pitz, N.; Piyarathna, D. B.; Planinic, M.; Płoskoń, M.; Pluta, J.; Pochybova, S.; Podesta-Lerma, P. L. M.; Poghosyan, M. G.; Polichtchouk, B.; Poljak, N.; Pop, A.; Porteboeuf-Houssais, S.; Pospíšil, V.; Potukuchi, B.; Prasad, S. K.; Preghenella, R.; Prino, F.; Pruneau, C. A.; Pshenichnov, I.; Puddu, G.; Punin, V.; Putschke, J.; Qvigstad, H.; Rachevski, A.; Rademakers, A.; Rak, J.; Rakotozafindrabe, A.; Ramello, L.; Raniwala, S.; Raniwala, R.; Räsänen, S. S.; Rascanu, B. T.; Rathee, D.; Rauch, W.; Rauf, A. W.; Razazi, V.; Read, K. F.; Real, J. S.; Redlich, K.; Reed, R. J.; Rehman, A.; Reichelt, P.; Reicher, M.; Reidt, F.; Renfordt, R.; Reolon, A. R.; Reshetin, A.; Rettig, F.; Revol, J.-P.; Reygers, K.; Riccati, L.; Ricci, R. A.; Richert, T.; Richter, M.; Riedler, P.; Riegler, W.; Riggi, F.; Rivetti, A.; Rodríguez Cahuantzi, M.; Rodriguez Manso, A.; Røed, K.; Rogochaya, E.; Rohni, S.; Rohr, D.; Röhrich, D.; Romita, R.; Ronchetti, F.; Rosnet, P.; Rossegger, S.; Rossi, A.; Roy, P.; Roy, C.; Rubio Montero, A. J.; Rui, R.; Russo, R.; Ryabinkin, E.; Rybicki, A.; Sadovsky, S.; Šafařík, K.; Sahoo, R.; Sahu, P. K.; Saini, J.; Sakaguchi, H.; Sakai, S.; Sakata, D.; Salgado, C. A.; Salzwedel, J.; Sambyal, S.; Samsonov, V.; Sanchez Castro, X.; Šándor, L.; Sandoval, A.; Sano, M.; Santagati, G.; Santoro, R.; Sarkar, D.; Scapparone, E.; Scarlassara, F.; Scharenberg, R. P.; Schiaua, C.; Schicker, R.; Schmidt, C.; Schmidt, H. R.; Schuchmann, S.; Schukraft, J.; Schulc, M.; Schuster, T.; Schutz, Y.; Schwarz, K.; Schweda, K.; Scioli, G.; Scomparin, E.; Scott, R.; Scott, P. A.; Segato, G.; Selyuzhenkov, I.; Seo, J.; Serci, S.; Serradilla, E.; Sevcenco, A.; Shabetai, A.; Shabratova, G.; Shahoyan, R.; Sharma, S.; Sharma, N.; Shigaki, K.; Shtejer, K.; Sibiriak, Y.; Siddhanta, S.; Siemiarczuk, T.; Silvermyr, D.; Silvestre, C.; Simatovic, G.; Singaraju, R.; Singh, R.; Singha, S.; Singhal, V.; Sinha, B. C.; Sinha, T.; Sitar, B.; Sitta, M.; Skaali, T. B.; Skjerdal, K.; Smakal, R.; Smirnov, N.; Snellings, R. J. M.; Søgaard, C.; Soltz, R.; Song, M.; Song, J.; Soos, C.; Soramel, F.; Spacek, M.; Sputowska, I.; Spyropoulou-Stassinaki, M.; Srivastava, B. K.; Stachel, J.; Stan, I.; Stefanek, G.; Steinpreis, M.; Stenlund, E.; Steyn, G.; Stiller, J. H.; Stocco, D.; Stolpovskiy, M.; Strmen, P.; Suaide, A. A. P.; Subieta Vásquez, M. A.; Sugitate, T.; Suire, C.; Suleymanov, M.; Sultanov, R.; Šumbera, M.; Susa, T.; Symons, T. J. M.; Szanto de Toledo, A.; Szarka, I.; Szczepankiewicz, A.; Szymański, M.; Takahashi, J.; Tangaro, M. A.; Tapia Takaki, J. D.; Tarantola Peloni, A.; Tarazona Martinez, A.; Tauro, A.; Tejeda Muñoz, G.; Telesca, A.; Terrevoli, C.; Ter Minasyan, A.; Thäder, J.; Thomas, D.; Tieulent, R.; Timmins, A. R.; Toia, A.; Torii, H.; Trubnikov, V.; Trzaska, W. H.; Tsuji, T.; Tumkin, A.; Turrisi, R.; Tveter, T. S.; Ulery, J.; Ullaland, K.; Ulrich, J.; Uras, A.; Urciuoli, G. M.; Usai, G. L.; Vajzer, M.; Vala, M.; Valencia Palomo, L.; Vande Vyvre, P.; Vannucci, L.; Van Hoorne, J. W.; van Leeuwen, M.; Vargas, A.; Varma, R.; Vasileiou, M.; Vasiliev, A.; Vechernin, V.; Veldhoen, M.; Venaruzzo, M.; Vercellin, E.; Vergara, S.; Vernet, R.; Verweij, M.; Vickovic, L.; Viesti, G.; Viinikainen, J.; Vilakazi, Z.; Villalobos Baillie, O.; Vinogradov, A.; Vinogradov, L.; Vinogradov, Y.; Virgili, T.; Viyogi, Y. P.; Vodopyanov, A.; Völkl, M. A.; Voloshin, S.; Voloshin, K.; Volpe, G.; von Haller, B.; Vorobyev, I.; Vranic, D.; Vrláková, J.; Vulpescu, B.; Vyushin, A.; Wagner, B.; Wagner, V.; Wagner, J.; Wang, Y.; Wang, Y.; Wang, M.; Watanabe, D.; Watanabe, K.; Weber, M.; Wessels, J. P.; Westerhoff, U.; Wiechula, J.; Wikne, J.; Wilde, M.; Wilk, G.; Wilkinson, J.; Williams, M. C. S.; Windelband, B.; Winn, M.; Xiang, C.; Yaldo, C. G.; Yamaguchi, Y.; Yang, H.; Yang, P.; Yang, S.; Yano, S.; Yasnopolskiy, S.; Yi, J.; Yin, Z.; Yoo, I.-K.; Yushmanov, I.; Zaccolo, V.; Zach, C.; Zampolli, C.; Zaporozhets, S.; Zarochentsev, A.; Závada, P.; Zaviyalov, N.; Zbroszczyk, H.; Zelnicek, P.; Zgura, I. S.; Zhalov, M.; Zhang, F.; Zhang, Y.; Zhang, H.; Zhang, X.; Zhou, D.; Zhou, Y.; Zhou, F.; Zhu, X.; Zhu, J.; Zhu, J.; Zhu, H.; Zichichi, A.; Zimmermann, M. B.; Zimmermann, A.; Zinovjev, G.; Zoccarato, Y.; Zynovyev, M.; Zyzak, M.

    2013-12-01

    Differential cross sections of charged particles in inelastic pp collisions as a function of p T have been measured at at the LHC. The p T spectra are compared to NLO-pQCD calculations. Though the differential cross section for an individual cannot be described by NLO-pQCD, the relative increase of cross section with is in agreement with NLO-pQCD. Based on these measurements and observations, procedures are discussed to construct pp reference spectra at up to p T=50 GeV/ c as required for the calculation of the nuclear modification factor in nucleus-nucleus and proton-nucleus collisions.

  14. Cylindrical mirror energy analyzer with the input of charged particles through end-surface diaphragm

    NASA Astrophysics Data System (ADS)

    Baranova, L. A.

    2016-08-01

    Computer simulation is used to study electron-optical properties of a cylindrical mirror analyzer with the input of charged particles through the end-surface diaphragm. Regimes with double crossing of the optical axis (two-stage analyzer) are considered to increase the linear dispersion. The external electrode of the electron-optical system under study can be divided into several insulated parts with independently controlled potentials. Such an approach allows the second-order tuning of focusing and wide-range variation in the dispersion. Optimal working regimes make it possible to increase the linear dispersion by a factor of 3-4 in comparison with the one-stage regime.

  15. Acceleration technologies for charged particles: an introduction

    NASA Astrophysics Data System (ADS)

    Carter, Richard G.

    2011-01-01

    Particle accelerators have many important uses in scientific experiments, in industry and in medicine. This paper reviews the variety of technologies which are used to accelerate charged particles to high energies. It aims to show how the capabilities and limitations of these technologies are related to underlying physical principles. The paper emphasises the way in which different technologies are used together to convey energy from the electrical supply to the accelerated particles.

  16. Energy deposition rates by charged particles measured during the energy budget campaign

    NASA Technical Reports Server (NTRS)

    Urban, A.; Torkar, K. M.; Bjordal, J.; Lundblad, J. A.; Soraas, F.; Grandal, B.; Smith, L. G.; Ulwick, J. C.; Vancour, R. P.

    1982-01-01

    Measurements of the precipitation of electrons and positive ions (in the keV to MeV range) detected aboard eight rockets launched from Northern Scandinavia are reported together with corresponding satellite data. The downgoing integral fluxes indicate the temporal fluctuations during each flight. Height profiles of the energy deposition into the atmosphere at different levels of geomagnetic disturbance are given.

  17. Charged particle therapy: the physics of interaction.

    PubMed

    Lomax, Antony J

    2009-01-01

    Particle therapy has a long and distinguished history with more than 50,000 patients having been treated, mainly with high-energy proton therapy. Particularly, for proton therapy, there is an increasing interest in exploiting the physical characteristics of charged particles for further improving the potential of radiation therapy. In this article, we review the most important interactions of charged particles with matter and describe the basic physical principles that underlie why particle beams behave the way they do and why such a behavior could bring many benefits in radiation therapy.

  18. Measuring momentum for charged particle tomography

    DOEpatents

    Morris, Christopher; Fraser, Andrew Mcleod; Schultz, Larry Joe; Borozdin, Konstantin N.; Klimenko, Alexei Vasilievich; Sossong, Michael James; Blanpied, Gary

    2010-11-23

    Methods, apparatus and systems for detecting charged particles and obtaining tomography of a volume by measuring charged particles including measuring the momentum of a charged particle passing through a charged particle detector. Sets of position sensitive detectors measure scattering of the charged particle. The position sensitive detectors having sufficient mass to cause the charged particle passing through the position sensitive detectors to scatter in the position sensitive detectors. A controller can be adapted and arranged to receive scattering measurements of the charged particle from the charged particle detector, determine at least one trajectory of the charged particle from the measured scattering; and determine at least one momentum measurement of the charged particle from the at least one trajectory. The charged particle can be a cosmic ray-produced charged particle, such as a cosmic ray-produced muon. The position sensitive detectors can be drift cells, such as gas-filled drift tubes.

  19. Photoelectric Charging of Dust Particles

    NASA Technical Reports Server (NTRS)

    Sickafoose, A.; Colwell, J.; Horanyi, M.; Robertson, S.; Walch, B.

    1999-01-01

    Laboratory experiments have been performed on the photoelectric charging of dust particles which are either isolated or adjacent to a surface that is also a photoemitter. We find that zinc dust charges to a positive potential of a few volts when isolated in vacuum and that it charges to a negative potential of a few volts when passed by a photoemitting surface. The illumination is an arc lamp emitting wavelengths longer than 200 nm and the emitting surface is a zirconium foil.

  20. Charged particle accelerator grating

    DOEpatents

    Palmer, Robert B.

    1986-01-01

    A readily disposable and replaceable accelerator grating for a relativistic particle accelerator. The grating is formed for a plurality of liquid droplets that are directed in precisely positioned jet streams to periodically dispose rows of droplets along the borders of a predetermined particle beam path. A plurality of lasers are used to direct laser beams into the droplets, at predetermined angles, thereby to excite the droplets to support electromagnetic accelerating resonances on their surfaces. Those resonances operate to accelerate and focus particles moving along the beam path. As the droplets are distorted or destroyed by the incoming radiation, they are replaced at a predetermined frequency by other droplets supplied through the jet streams.

  1. Charged particle accelerator grating

    DOEpatents

    Palmer, Robert B.

    1986-09-02

    A readily disposable and replaceable accelerator grating for a relativistic particle accelerator. The grating is formed for a plurality of liquid droplets that are directed in precisely positioned jet streams to periodically dispose rows of droplets along the borders of a predetermined particle beam path. A plurality of lasers are used to direct laser beams into the droplets, at predetermined angles, thereby to excite the droplets to support electromagnetic accelerating resonances on their surfaces. Those resonances operate to accelerate and focus particles moving along the beam path. As the droplets are distorted or destroyed by the incoming radiation, they are replaced at a predetermined frequency by other droplets supplied through the jet streams.

  2. High energy particle astronomy.

    NASA Technical Reports Server (NTRS)

    Buffington, A.; Muller, R. A.; Smith, L. H.; Smoot, G. F.

    1972-01-01

    Discussion of techniques currently used in high energy particle astronomy for measuring charged and neutral cosmic rays and their isotope and momentum distribution. Derived from methods developed for accelerator experiments in particle physics, these techniques help perform important particle astronomy experiments pertaining to nuclear cosmic ray and gamma ray research, electron and position probes, and antimatter searches.

  3. Charged particle periodicity in the Saturnian magnetosphere

    NASA Technical Reports Server (NTRS)

    Carbary, J. F.; Krimigis, S. M.

    1982-01-01

    The present investigation is concerned with the first definitive evidence for charged particle modulations near the magnetic rotation period at Saturn. This periodicity is apparent in the ratios (and spectra) of low energy charged particles in the Saturnian magnetosphere. Most of the data presented were taken during the Voyager 2 outbound portion of the Saturn encounter. During this time the spacecraft was at high latitudes (approximately 30 deg) in the southern hemisphere of the Saturnian magnetosphere. The probe's trajectory was approximately along the dawn meridian at an essentially constant local time. The observation that the charged particle modulation is consistent with the Saturn Kilometric Radiation (SKR) period provides a basic input for the resolution of a puzzle which has existed ever since the discovery of the SKR modulation. The charged particle periodicity identified suggests that a basic asymmetry must exist in the Saturnian magnetosphere.

  4. Electrostatic wire stabilizing a charged particle beam

    DOEpatents

    Prono, D.S.; Caporaso, G.J.; Briggs, R.J.

    1983-03-21

    In combination with a charged particle beam generator and accelerator, apparatus and method are provided for stabilizing a beam of electrically charged particles. A guiding means, disposed within the particle beam, has an electric charge induced upon it by the charged particle beam. Because the sign of the electric charge on the guiding means and the sign of the particle beam are opposite, the particles are attracted toward and cluster around the guiding means to thereby stabilize the particle beam as it travels.

  5. Charged particle accelerator grating

    DOEpatents

    Palmer, R.B.

    1985-09-09

    A readily disposable and replaceable accelerator grating for a relativistic particle accelerator is described. The grating is formed for a plurality of liquid droplets that are directed in precisely positioned jet streams to periodically dispose rows of droplets along the borders of a predetermined particle beam path. A plurality of lasers are used to direct laser beams onto the droplets, at predetermined angles, thereby to excite the droplets to support electromagnetic accelerating resonances on their surfaces. Those resonances operate to accelerate and focus particles moving along the beam path. As the droplets are distorted or destroyed by the incoming radiation, they are replaced at a predetermined frequency by other droplets supplied through the jet streams.

  6. Quasi-energy spectrum and dynamical localizations of two charged particles in a one-dimensional lattice system

    NASA Astrophysics Data System (ADS)

    Wang, Zhi-Gang; Suqing, Duan; Zhao, Xian-Geng

    2006-04-01

    The quasi-energy spectrum of two charged particles in a one-dimensional lattice system driven by an external field are theoretically studied with the help of numerical calculations. It is found that the quasi-energy spectrum splits into two regions. In the gourd-shaped region the Floquet states mainly contain the Wannier states |l,m> (l≠m), which describe the two particles occupy the different sites. The (avoid) crossing points in this region are corresponding to the dynamical localizations of the two particles which initially occupy on different sites when the distance between the initial sites is large. These conditions of dynamical localization are the same as that in single particle system. In the other region (electron electron or electron hole pair region), the Floquet states mainly contain the Wannier states |l,l>, which describe the two particles simultaneously occupy the lth site. The (avoid) crossing points in this region are corresponding to the dynamical localizations of the two particles happening which initially occupy on same site.

  7. Integrated development facility for the calibration of low-energy charged particle flight instrumentation

    NASA Technical Reports Server (NTRS)

    Biddle, A. P.; Reynolds, J. M.

    1986-01-01

    The design of a low-energy ion facility for development and calibration of thermal ion instrumentation is examined. A directly heated cathode provides the electrons used to produce ions by impact ionization and an applied magnetic field increases the path length followed by the electrons. The electrostatic and variable geometry magnetic mirror configuration in the ion source is studied. The procedures for the charge neutralization of the beam and the configuration and function of the 1.4-m drift tube are analyzed. A microcomputer is utilized to control and monitor the beam energy and composition, and the mass- and angle-dependent response of the instrument under testing. The facility produces a high-quality ion beam with an adjustable range of energies up to 150 eV; the angular divergence and uniformity of the beam is obtained from two independent retarding potential analyzers. The procedures for calibrating the instrument being developed are described.

  8. Electron-ion energy partition when a charged particle slows in a plasma: theory.

    PubMed

    Brown, Lowell S; Preston, Dean L; Singleton, Robert L

    2012-07-01

    The preceding paper [Brown, Preston, and Singleton Jr., Phys. Rev. E 86, 016406 (2012)] presented precise results for the partition of the initial energy E(0) of a fast particle into the ions and electrons--E(I)/E(0) and E(e)/E(0)--when the fast particle slows in a plasma whose ion and electron temperatures may differ. As emphasized in that paper, this is an important problem because nuclear fusion reactions, such as those that occur in an inertial confinement fusion capsule, involve ion temperatures that run away from the electron temperatures. As also noted in the preceding paper, a precise evaluation entails the use of a well-defined Fokker-Planck equation for the phase-space evolution of initially fast projectile particles. When the plasma has differing ion and electron temperatures, the projectiles must slow into a "schizophrenic" final ensemble of particles that has neither the electron nor the ion temperature. This is not a simple Maxwell-Boltzmann distribution since the electrons are not in thermal equilibrium with the ions. Thus, detailed calculations are required for the solution of the problem. These we provide here for a weakly to moderately coupled plasma. The Fokker-Planck equation holds to first subleading order in the dimensionless plasma coupling constant, which translates to computing to order n ln n (leading) and n (subleading) in the plasma density n. The energy partitions for a background plasma in thermal equilibrium have been previously computed, but the order n terms have not been calculated, only estimated. The "schizophrenic" final ensemble of slowed particles gives a new mechanism to bring the electron and ion temperatures together. The rate at which this new mechanism brings the electrons and ions in the plasma into thermal equilibrium will be computed. PMID:23005550

  9. DIFFUSIVE SHOCK ACCELERATION OF HIGH-ENERGY CHARGED PARTICLES AT FAST INTERPLANETARY SHOCKS: A PARAMETER SURVEY

    SciTech Connect

    Giacalone, Joe

    2015-01-20

    We present results from numerical simulations of the acceleration of solar energetic particles (SEPs) associated with strong, fast, and radially propagating interplanetary shocks. We focus on the phase of the SEP event at the time of the shock passage at 1 AU, which is when the peak intensity at energies below a few MeV is the highest. The shocks in our study start between 2 and 10 solar radii and propagate beyond 1 AU. We study the effect of various shock and particle input parameters, such as the spatial diffusion coefficient, shock speed, solar wind speed, initial location of the shock, and shock deceleration rate, on the total integrated differential intensity, I, of SEPs with kinetic energies > 10 MeV. I is the integral over energy of the differential intensity spectrum at the time of the shock passage at 1 AU. We find that relatively small changes in the parameters can lead to significant event-to-event changes in I. For example, a factor of 2 increase in the diffusion coefficient at a given energy and spatial location, can lead to a decrease in I by as much as a factor of 50. This may help explain why there are fewer large SEP events seen during the current solar maximum compared to previous maxima. It is known that the magnitude of the interplanetary magnetic field is noticeably weaker this solar cycle than it was in the previous cycle and this will naturally lead to a somewhat larger diffusion coefficient of SEPs.

  10. Critical escape velocity for a charged particle in Ernst spacetime

    NASA Astrophysics Data System (ADS)

    Huang, Qihong; Chen, Juhua; Wang, Yongjiu

    2015-05-01

    Motion of a charged particle in Ernst spacetime is discussed. We study the conditions that a charged particle, originally revolving around this black hole in the innermost stable circular orbit (ISCO), will escape to infinity after being kicked by another particle or photon. The motion of the kicked particle is chaotic. The critical escape energy and velocity of the charged particle are obtained in the present paper. Comparing to the Schwarzschild case, the kicked charged particle without the radial velocity needs more energy to escape in Ernst case for l > 0 and less energy to escape for l < 0.

  11. Thick-lens velocity-map imaging spectrometer with high resolution for high-energy charged particles

    NASA Astrophysics Data System (ADS)

    Kling, N. G.; Paul, D.; Gura, A.; Laurent, G.; De, S.; Li, H.; Wang, Z.; Ahn, B.; Kim, C. H.; Kim, T. K.; Litvinyuk, I. V.; Cocke, C. L.; Ben-Itzhak, I.; Kim, D.; Kling, M. F.

    2014-05-01

    A novel design for a velocity-map imaging (VMI) spectrometer with high resolution over a wide energy range surpassing a standard VMI design is reported. The main difference to a standard three-electrode VMI is the spatial extension of the applied field using 11 electrodes forming a thick-lens. This permits measurements of charged particles with higher energies while achieving excellent resolving power over a wide range of energies. Using SIMION simulations, the thick-lens VMI is compared to a standard design for up to 360 eV electrons. The simulations also show that the new spectrometer design is suited for charged-particle detection with up to 1 keV using a repeller-electrode voltage of -30 kV. The experimental performance is tested by laser-induced ionization of rare gases producing electrons up to about 70 eV. The thick-lens VMI is useful for a wide variety of studies on atoms, molecules and nanoparticles in intense laser fields and high-photon-energy fields from high-harmonic-generation or free-electron lasers.

  12. Predictions on the transverse momentum spectra for charged particle production at LHC-energies from a two component model

    NASA Astrophysics Data System (ADS)

    Bylinkin, A. A.; Chernyavskaya, N. S.; Rostovtsev, A. A.

    2015-04-01

    Transverse momentum spectra, , of charged hadron production in -collisions are considered in terms of a recently introduced two component model. The shapes of the particle distributions vary as a function of the c.m.s. energy in the collision and the measured pseudorapidity interval. As a result the pseudorapidity of a secondary hadron in the moving proton rest frame is shown to be a universal parameter describing the shape of the spectra in pp-collisions. In order to extract predictions on the double-differential cross sections of hadron production for future LHC-measurements the different sets of available experimental data have been used in this study.

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

    SciTech Connect

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

    2015-09-15

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

  14. Magnetometer Application for GAMMA-400 Telescope Switching into the Mode with Increased Low Energy Charged Particles Intensity Registration

    NASA Astrophysics Data System (ADS)

    Khyzhniak, E. V.; Arkhangelskaja, I. V.; Chasovikov, E. N.; Arkhangelskiy, A. I.; Topchiev, N. P.

    GAMMA-400 is an international project of a high apogee orbital astrophysical observatory for studying the characteristics of high-energy gamma-emission, electrons/positrons and light nuclei fluxes. The energy range for γ-rays and electrons/positrons registration in the main aperture is from ∼0.1 GeV to ∼3.0 TeV. Also, this aperture allows high energy light nuclei fluxes characteristics investigation. Moreover, special aperture configuration allows registering of gamma-quanta, electrons (positrons) and light nuclei from the lateral directions too. The spacecraft GAMMA-400 orbit will be located in the Earth's magnetosphere and will pass front shock wave from magnetosphere interaction with the solar wind, turbulent-transition region, magnetopause and so on. During the satellite's movement through various Earth's magnetosphere regions its anticoincidence detectors will register high intensity fluxes of low energy charged particles captured by the magnetic field. The working area sections of GAMMA-400 detector systems used as anticoincidence shield are about 1 m2 each. The high intensity low energy charged particles flux influence on anticoincidence detectors should be taken into account during particle identification. This article presents a comparison between Earth's magnetosphere theoretical model according to SPENVIIS package and real data measured by detectors onboard THEMIS series satellites. The differences between these two datasets indicate that the calculated data are not sufficient to make short time predictions of variations of magnetic induction in the outer magnetosphere. A special trigger marker flag will be produced by GAMMA-400 counting and triggers signals formation system accordingly to the data of two onboard magnetometers. This flag's presence leads to special algorithms execution start, putting the plastic detectors into a dedicated working mode taking into account possible high count rates of external detector layers.

  15. Charged particle mobility refrigerant analyzer

    DOEpatents

    Allman, Steve L.; Chen, Chung-Hsuan; Chen, Fang C.

    1993-01-01

    A method for analyzing a gaseous electronegative species comprises the steps of providing an analysis chamber; providing an electric field of known potential within the analysis chamber; admitting into the analysis chamber a gaseous sample containing the gaseous electronegative species; providing a pulse of free electrons within the electric field so that the pulse of free electrons interacts with the gaseous electronegative species so that a swarm of electrically charged particles is produced within the electric field; and, measuring the mobility of the electrically charged particles within the electric field.

  16. Charged particle mobility refrigerant analyzer

    DOEpatents

    Allman, S.L.; Chunghsuan Chen; Chen, F.C.

    1993-02-02

    A method for analyzing a gaseous electronegative species comprises the steps of providing an analysis chamber; providing an electric field of known potential within the analysis chamber; admitting into the analysis chamber a gaseous sample containing the gaseous electronegative species; providing a pulse of free electrons within the electric field so that the pulse of free electrons interacts with the gaseous electronegative species so that a swarm of electrically charged particles is produced within the electric field; and, measuring the mobility of the electrically charged particles within the electric field.

  17. Charge-collection efficiency of single-crystal CVD diamond detector for low-energy charged particles with energies ranging from 100 keV to 2 MeV

    NASA Astrophysics Data System (ADS)

    Sato, Yuki; Murakami, Hiroyuki; Shimaoka, Takehiro; Tsubota, Masakatsu; Kaneko, Junichi H.

    2016-10-01

    The performance of a diamond detector created from a single-crystal diamond grown by chemical vapor deposition was studied for application in detecting charged particles having energies ranging from 100 keV to 2 MeV. Energy peaks of different low-energy ions were clearly observed. However, we observed that the pulse height for individual incident ions decreases with increasing atomic number of the ions. We estimated the charge collection efficiency of the generated charge carriers by the incident charged particles. The charge collection efficiencies are 97.0 ± 0.7% for 2 MeV helium-ions (He+). On the other hand, compared with that of He+, silicon-ions (Si+) and gold-ions (Au3+) show low charge collection efficiency: 70.6 ± 2.2% and 29.5 ± 4.2% for 2 MeV-Si+ and 2 MeV-Au3+, respectively. We also found that the charge collection efficiency decreases as the generated charge density inside the diamond crystal increases.

  18. Centrality and energy dependence of charged-particle multiplicities in heavy ion collisions in the context of elementary reactions

    SciTech Connect

    Back, B. B.; Wuosmaa, A. H.; Baker, M. D.; Barton, D. S.; Carroll, A.; Gushue, S.; Heintzelman, G. A.; Holzman, B.; Pak, R.; Remsberg, L. P.; Steinberg, P.; Sukhanov, A.; Betts, R. R.; Garcia, E.; Halliwell, C.; Hofman, D. J.; Hollis, R. S.; Iordanova, A.; Kucewicz, W.; McLeod, D.

    2006-08-15

    The PHOBOS experiment at the BNL Relativistic Heavy Ion Collider has measured the total multiplicity of primary charged particles as a function of collision centrality in Au+Au collisions at {radical}(s{sub NN})= 19.6, 130, and 200 GeV. An approximate independence of / on the number of participating nucleons is observed, reminiscent of 'wounded nucleon' scaling (N{sub ch}{proportional_to}N{sub part}) observed in proton-nucleus collisions. Unlike p+A, the constant of proportionality does not seem to be set by the pp/pp data at the same energy. Rather, there seems to be a surprising correspondence with the total multiplicity measured in e{sup +}e{sup -} annihilations, as well as the rapidity shape measured over a large range. The energy dependence of the integrated multiplicity per participant pair shows that e{sup +}e{sup -} and A+A data agree over a large range of center-of-mass energies ({radical}(s)>20 GeV), and pp/pp data can be brought to agree approximately with the e{sup +}e{sup -} data by correcting for the typical energy taken away by leading particles. This is suggestive of a mechanism for soft particle production that depends mainly on the amount of available energy. It is conjectured that the dominant distinction between A+A and p+p collisions is the multiple collisions per participant, which appears to be sufficient to substantially reduce the energy taken away by leading particles.

  19. General stationary charged black holes as charged particle accelerators

    NASA Astrophysics Data System (ADS)

    Zhu, Yi; Wu, Shao-Feng; Liu, Yu-Xiao; Jiang, Ying

    2011-08-01

    We study the possibility of getting infinite energy in the center-of-mass frame of colliding charged particles in a general stationary charged black hole. For black holes with twofold degenerate horizon, it is found that arbitrary high center-of-mass energy can be attained, provided that one of the particle has critical angular momentum or critical charge and the remained parameters of particles and black holes satisfy certain restriction. For black holes with multiple-fold degenerate event horizons, the restriction is released. For nondegenerate black holes, the ultrahigh center-of-mass is possible to be reached by invoking the multiple scattering mechanism. We obtain a condition for the existence of innermost stable circular orbit with critical angular momentum or charge on any-fold degenerate horizons, which is essential to get ultrahigh center-of-mass energy without fine-tuning problem. We also discuss the proper time spending by the particle to reach the horizon and the duality between frame-dragging effect and electromagnetic interaction. Some of these general results are applied to braneworld small black holes.

  20. Observation of the Askaryan Effect: Coherent Microwave Cherenkov Emission From Charge Asymmetry in High-Energy Particle Cascades

    SciTech Connect

    Field, Clive

    2001-01-24

    We present the first direct experimental evidence for the charge excess in high energy particle showers predicted nearly 40 years ago by Askaryan. We directed bremsstrahlung photons from picosecond pulses of 28.5 GeV electrons at the SLAC Final Focus Test Beam facility into a 3.5 ton silica sand target, producing electromagnetic showers several meters long. A series of antennas spanning 0.3 to 6 GHz were used to detect strong, sub-nanosecond radio frequency pulses produced whenever a shower was present. The measured electric field strengths are consistent with a completely coherent radiation process. The pulses show 100% linear polarization, consistent with the expectations of Cherenkov radiation. The field strength versus depth closely follows the expected particle number density profile of the cascade, consistent with emission from excess charge distributed along the shower. These measurements therefore provide strong support for experiments designed to detect high energy cosmic rays and neutrinos via coherent radio emission from their cascades.

  1. System Size, Energy, and Centrality Dependence of Pseudorapidity Distributions of Charged Particles in Relativistic Heavy-Ion Collisions

    SciTech Connect

    Alver, B.; Back, B. B.; Baker, M. D.; Barton, D. S.; Chai, Z.; Holzman, B.; Nouicer, R.; Pak, R.; Sedykh, I.; Stankiewicz, M. A.; Steinberg, P.; Sukhanov, A.; Szostak, A.; Wyngaardt, S.; Ballintijn, M.; Busza, W.; Gulbrandsen, K.; Henderson, C.; Kane, J. L.; Kulinich, P.

    2009-04-10

    We present the first measurements of the pseudorapidity distribution of primary charged particles in Cu+Cu collisions as a function of collision centrality and energy, {radical}(s{sub NN})=22.4, 62.4, and 200 GeV, over a wide range of pseudorapidity, using the PHOBOS detector. A comparison of Cu+Cu and Au+Au results shows that the total number of produced charged particles and the rough shape (height and width) of the pseudorapidity distributions are determined by the number of nucleon participants. More detailed studies reveal that a more precise matching of the shape of the Cu+Cu and Au+Au pseudorapidity distributions over the full range of pseudorapidity occurs for the same N{sub part}/2A rather than the same N{sub part}. In other words, it is the collision geometry rather than just the number of nucleon participants that drives the detailed shape of the pseudorapidity distribution and its centrality dependence at RHIC energies.

  2. Health Risks of Space Exploration: Targeted and Nontargeted Oxidative Injury by High-Charge and High-Energy Particles

    PubMed Central

    Li, Min; Gonon, Géraldine; Buonanno, Manuela; Autsavapromporn, Narongchai; de Toledo, Sonia M.; Pain, Debkumar

    2014-01-01

    Abstract Significance: During deep space travel, astronauts are often exposed to high atomic number (Z) and high-energy (E) (high charge and high energy [HZE]) particles. On interaction with cells, these particles cause severe oxidative injury and result in unique biological responses. When cell populations are exposed to low fluences of HZE particles, a significant fraction of the cells are not traversed by a primary radiation track, and yet, oxidative stress induced in the targeted cells may spread to nearby bystander cells. The long-term effects are more complex because the oxidative effects persist in progeny of the targeted and affected bystander cells, which promote genomic instability and may increase the risk of age-related cancer and degenerative diseases. Recent Advances: Greater understanding of the spatial and temporal features of reactive oxygen species bursts along the tracks of HZE particles, and the availability of facilities that can simulate exposure to space radiations have supported the characterization of oxidative stress from targeted and nontargeted effects. Critical Issues: The significance of secondary radiations generated from the interaction of the primary HZE particles with biological material and the mitigating effects of antioxidants on various cellular injuries are central to understanding nontargeted effects and alleviating tissue injury. Future Directions: Elucidation of the mechanisms underlying the cellular responses to HZE particles, particularly under reduced gravity and situations of exposure to additional radiations, such as protons, should be useful in reducing the uncertainty associated with current models for predicting long-term health risks of space radiation. These studies are also relevant to hadron therapy of cancer. Antioxid. Redox Signal. 20, 1501–1523. PMID:24111926

  3. Charged particle multiplicity studies with PHOBOS.

    SciTech Connect

    Alver, B.; Back, B. B.; Baker, M. D.; Ballintijn, M.; Barton, D. S.; Physics; Massachusetts Inst. of Tech.; BNL

    2008-01-01

    Summary and conclusion: (1) Multiplicity - PHOBOS have performed complete charged particle multiplicity measurements for Au+Au, Cu+Cu, d+Au, and p+p collisions, System size dependence, and 'Complete' pseudorapidity distributions; 'Universality' compared to elementary e+e- collisions; and (2) Midrapidity multiplicity - Factorization of centrality and energy dependencies; (3) Limiting fragmentation - extended longitudinal scaling - Seen for Au+Au, Cu+Cu, and d+Au, Also observed in flow observables; (4) Total charged particle multiplicity - N{sub ch}/N{sub part} constant with centrality, (5) Future - Finish up many analysis and reviews.

  4. The Effect of Single Particle Charge Limits on Particle Charge Distributions in Dusty Plasmas

    NASA Astrophysics Data System (ADS)

    Girshick, Steven; Le Picard, Romain

    2013-09-01

    There is a limit to the number of electrons that can coexist on a dust particle in a plasma. This limit depends on the particle's surface potential, electron affinity and the inter-electron Coulomb repulsion. We conducted numerical simulations that examine the effect of charge limits on steady-state particle charge distributions, as well as on the time required to reach steady state. Attachment of electrons to a cloud of nanoparticles can severely deplete the electron density and increase the ion density, causing the electron-to-ion density ratio to be much less than unity. At sufficiently high values of the density ratio, e.g. above about 0.1 for 80-nm-diameter Si particles, the charge limit strongly constrains particle charge. At lower values of the density ratio, e.g. around 0.01, particles are much less negatively charged even in the absence of a charge limit, and therefore the limit makes only a small difference. However, in this regime the charge distribution still deviates from the Gaussian form predicted by previous work that neglects charge limits. For the case of Maxwellian electron velocity distributions, we find that whether or not particle charge distributions are significantly affected by charge limits depends on the dimensionless asymmetry charging factor p and on particle size. The factor p in turn depends on the ratios of electron-to-ion density, temperature and mass. Partially supported by the US NSF (grant CHE-1124752), US DOE Office of Fusion Energy Science (grant DE-SC0001939), and the Minnesota Supercomputing Institute.

  5. Search milli-charged particles at SLAC

    SciTech Connect

    Langeveld, W.G.J.

    1997-01-01

    Particles with electric charge q {triple_bond} Qe {le} 10{sup -3} e and masses in the range 1-1000 MeV/c{sup 2} are not excluded by present experiments or by astrophysical or cosmological arguments. A beam dump experiment uniquely suited to the detection of such {open_quotes}milli-charged{close_quotes} particles has been carried out at SLAC, utilizing the short-duration pulses of the SLC electron beam to establish a tight coincidence window for the signal. The detector, a large scintillation counter sensitive to very small energy depositions, provided much greater sensitivity than previous searches. Analysis of the data leads to the exclusion of a substantial portion of the charge-mass plane. In this report, a preliminary mass-dependent upper limit is presented for the charge of milli-charged particles, ranging from Q = 1.7 x 10{sup -5} at milli-charged particle mass 0.1 MeV/c{sup 2} to Q = 9.5 x 10{sup -4} at 100 MeV/c{sup 2}.

  6. Observation of the Askaryan Effect: Coherent Microwave Cherenkov Emission from Charge Asymmetry in High-Energy Particle Cascades

    SciTech Connect

    Saltzberg, David; Gorham, Peter; Walz, Dieter; Field, Clive; Iverson, Richard; Odian, Allen; Resch, George; Schoessow, Paul; Williams, Dawn

    2001-03-26

    We present the first direct experimental evidence for the charge excess in high-energy particle showers and corresponding radio emission predicted nearly 40 years ago by Askaryan. We directed picosecond pulses of GeV bremsstrahlung photons at the SLAC Final Focus Test Beam into a 3.5 ton silica sand target, producing electromagnetic showers several meters long. A series of antennas spanning 0.3 to 6GHz detected strong, subnanosecond radio-frequency pulses produced by the showers. Measurements of the polarization, coherence, timing, field strength vs shower depth, and field strength vs frequency are completely consistent with predictions. These measurements thus provide strong support for experiments designed to detect high-energy cosmic rays such as neutrinos via coherent radio emission from their cascades.

  7. Observation of the Askaryan effect: coherent microwave Cherenkov emission from charge asymmetry in high-energy particle cascades.

    PubMed

    Saltzberg, D; Gorham, P; Walz, D; Field, C; Iverson, R; Odian, A; Resch, G; Schoessow, P; Williams, D

    2001-03-26

    We present the first direct experimental evidence for the charge excess in high-energy particle showers and corresponding radio emission predicted nearly 40 years ago by Askaryan. We directed picosecond pulses of GeV bremsstrahlung photons at the SLAC Final Focus Test Beam into a 3.5 ton silica sand target, producing electromagnetic showers several meters long. A series of antennas spanning 0.3 to 6 GHz detected strong, subnanosecond radio-frequency pulses produced by the showers. Measurements of the polarization, coherence, timing, field strength vs shower depth, and field strength vs frequency are completely consistent with predictions. These measurements thus provide strong support for experiments designed to detect high-energy cosmic rays such as neutrinos via coherent radio emission from their cascades. PMID:11290043

  8. Testing model energy spectra of charged particles produced in hadron interactions on the basis of atmospheric muons

    SciTech Connect

    Dedenko, L. G.; Roganova, T. M.; Fedorova, G. F.

    2015-10-15

    An original method for calculating the spectrum of atmospheric muons with the aid of the CORSIKA 7.4 code package and numerical integration is proposed. The first step consists in calculating the energy distribution of muons for various fixed energies of primary-cosmic-ray particles and within several chosen hadron-interaction models included in the CORSIKA 7.4 code package. After that, the spectrum of atmospheric muons is calculated via integrating the resulting distribution densities with the chosen spectrum of primary-cosmic-ray particles. The atmospheric-muon fluxes that were calculated on the basis of the SIBYLL 2.1, QGSJET01, and QGSJET II-04 models exceed the predictions of the wellknown Gaisser approximation of this spectrum by a factor of 1.5 to 1.8 in the range of muon energies between about 10{sup 3} and 10{sup 4} GeV.Under the assumption that, in the region of extremely highmuon energies, a dominant contribution to the muon flux comes from one to two generations of charged π{sup ±} and K{sup ±} mesons, the production rate calculated for these mesons is overestimated by a factor of 1.3 to 1.5. This conclusion is confirmed by the results of the LHCf and TOTEM experiments.

  9. Charge, energy and LET spectra of high LET primary and secondary particles in CR-39 plastic nuclear track detectors of the P0006 experiment

    NASA Technical Reports Server (NTRS)

    Csige, I.; Frigo, L. A.; Benton, E. V.; Oda, K.

    1995-01-01

    We have measured the charge, energy and linear energy transfer (LET) spectra of about 800 high LET (LET(sub infinity) H2O greater than 50 keV/micron) particles in CR-39 plastic nuclear track detectors in the P0006 experiment of LDEF. Primary particles with residual range at the reference surface greater than about 2 microns and secondary particles produced in the detector material with total range greater than about 4 microns were measured. We have used a multi-etch technique and an internal calibration to identify and measure the energy of the particles at the reference surface. The LET spectrum was obtained from the charge and energy distribution of the particles.

  10. CHARGED PARTICLE MULTIPLICITIES AT BRAHMS.

    SciTech Connect

    DEBBE, R., FOR THE BRAHMS COLLABORATION

    2001-07-30

    This report presents the measurement of charged particle multiplicity densities dN/d{eta} in ultrarelativistic heavy ion collisions as function of {eta} and the centrality of the collisions. This distributions were extracted from data collected by the BRAHMS collaboration during the first RHK run with gold ions at {radical}s{sub NN} = 130A {center_dot} GeV. The analysis method is described and, results are compared to some model predictions.

  11. Charged particles in Titan's ionosphere

    NASA Astrophysics Data System (ADS)

    Tripathi, Sachchida

    2010-05-01

    Charged particles in Titan's ionosphere Marykutty Michael1, Sachchida Nand Tripathi1,2,3, Pratima Arya1 1Indian Institute of Technology Kanpur 2Oak Ridge Associated Universities 3NASA Goddard Space Flight Center Observations by two instruments onboard the Cassini spacecraft, Ion Neutral Mass Spectrometer (INMS) and CAssini Plasma Spectrometer (CAPS), revealed the existence of heavy hydrocarbon and nitrile species with masses of several thousand atomic mass units at altitudes of 950 - 1400 km in the atmosphere of Titan (Waite et al., 2007; Crary et al., 2009). Though these particles were believed to be molecules, they are most likely aerosols formed by the clumping of smaller molecules (Waite et al., 2009). These particles were estimated to have a density of 10-3 kg m-3 and a size of up to 256 nm. The existence of very heavy ions has also been observed by the CAPS components with a mass by charge ratio of up to 10000 (Coates et al., 2007, 2009; Sittler et al., 2009). The goal of this paper is to find out whether the so called heavy ions (or charged particles) are generated by the charge transfer of ions and electrons to the particles. The charging of these particles has been studied by using the charge balance equations that include positive ions, negative ions, electrons, neutral and charged particles. Information on the most abundant ion clusters are obtained from Vuitton et al., (2009) and Wilson and Atreya, (2004). Mass by charge ratio thus calculated will be compared with those observed by Coates et al. (2007). References: Coates AJ, et al., Discovery of heavy negative ions in Titan's ionosphere, Geophys. Res. Lett., 34:L22103, 2007. Coates AJ, et al., Heavy negative ions in titan's ionosphere: altitude and latitude dependence. Planet. Space Sci., doi:10.1016/j.pss.2009.05.009, 2009. Crary F.J., et al., Heavy ions, temperatures and winds in titan's ionosphere: Combined cassini caps and inms observations. Planet. Space Sci., doi:10.1016/j.pss.2009.09.006, 2009

  12. A multi-dimensional, energy- and charge-conserving, nonlinearly implicit, electromagnetic Vlasov–Darwin particle-in-cell algorithm

    DOE PAGESBeta

    Chen, G.; Chacón, L.

    2015-08-11

    For decades, the Vlasov–Darwin model has been recognized to be attractive for particle-in-cell (PIC) kinetic plasma simulations in non-radiative electromagnetic regimes, to avoid radiative noise issues and gain computational efficiency. However, the Darwin model results in an elliptic set of field equations that renders conventional explicit time integration unconditionally unstable. We explore a fully implicit PIC algorithm for the Vlasov–Darwin model in multiple dimensions, which overcomes many difficulties of traditional semi-implicit Darwin PIC algorithms. The finite-difference scheme for Darwin field equations and particle equations of motion is space–time-centered, employing particle sub-cycling and orbit-averaging. This algorithm conserves total energy, local charge,more » canonical-momentum in the ignorable direction, and preserves the Coulomb gauge exactly. An asymptotically well-posed fluid preconditioner allows efficient use of large cell sizes, which are determined by accuracy considerations, not stability, and can be orders of magnitude larger than required in a standard explicit electromagnetic PIC simulation. Finally, we demonstrate the accuracy and efficiency properties of the algorithm with various numerical experiments in 2D–3V.« less

  13. A multi-dimensional, energy- and charge-conserving, nonlinearly implicit, electromagnetic Vlasov-Darwin particle-in-cell algorithm

    NASA Astrophysics Data System (ADS)

    Chen, G.; Chacón, L.

    2015-12-01

    For decades, the Vlasov-Darwin model has been recognized to be attractive for particle-in-cell (PIC) kinetic plasma simulations in non-radiative electromagnetic regimes, to avoid radiative noise issues and gain computational efficiency. However, the Darwin model results in an elliptic set of field equations that renders conventional explicit time integration unconditionally unstable. Here, we explore a fully implicit PIC algorithm for the Vlasov-Darwin model in multiple dimensions, which overcomes many difficulties of traditional semi-implicit Darwin PIC algorithms. The finite-difference scheme for Darwin field equations and particle equations of motion is space-time-centered, employing particle sub-cycling and orbit-averaging. The algorithm conserves total energy, local charge, canonical-momentum in the ignorable direction, and preserves the Coulomb gauge exactly. An asymptotically well-posed fluid preconditioner allows efficient use of large cell sizes, which are determined by accuracy considerations, not stability, and can be orders of magnitude larger than required in a standard explicit electromagnetic PIC simulation. We demonstrate the accuracy and efficiency properties of the algorithm with various numerical experiments in 2D-3V.

  14. A multi-dimensional, energy- and charge-conserving, nonlinearly implicit, electromagnetic Vlasov–Darwin particle-in-cell algorithm

    SciTech Connect

    Chen, G.; Chacón, L.

    2015-08-11

    For decades, the Vlasov–Darwin model has been recognized to be attractive for particle-in-cell (PIC) kinetic plasma simulations in non-radiative electromagnetic regimes, to avoid radiative noise issues and gain computational efficiency. However, the Darwin model results in an elliptic set of field equations that renders conventional explicit time integration unconditionally unstable. We explore a fully implicit PIC algorithm for the Vlasov–Darwin model in multiple dimensions, which overcomes many difficulties of traditional semi-implicit Darwin PIC algorithms. The finite-difference scheme for Darwin field equations and particle equations of motion is space–time-centered, employing particle sub-cycling and orbit-averaging. This algorithm conserves total energy, local charge, canonical-momentum in the ignorable direction, and preserves the Coulomb gauge exactly. An asymptotically well-posed fluid preconditioner allows efficient use of large cell sizes, which are determined by accuracy considerations, not stability, and can be orders of magnitude larger than required in a standard explicit electromagnetic PIC simulation. Finally, we demonstrate the accuracy and efficiency properties of the algorithm with various numerical experiments in 2D–3V.

  15. Resistance of Bacillus subtilis spores to 12C ion beams, stimulation of high-energy charged particles in space

    NASA Astrophysics Data System (ADS)

    Zhang, Li; Dang, Bingrong; Li, Junxiong; Chen, Jinsong; Liu, Mei; Liu, Zhiheng; Zhang, Lixin

    To monitor the response of live microbes in space radiation environment with high-energy charged particles, we carry out ground stimulation radiation experiments. Spores of Bacillus (CGMCC 1.1849) species are one of the model systems used for astro- and radiobiological studies. (12) C ion beams served as stimulated space radiation from 5gry, 10gry, 20gry, 40gry, to 80gry at a rate of 15gry/min Death rates are measured and mutant strains are isolated. Five representative strains are analyzed for their corresponding gene sequences, protein sequences and gene expression index of DNA repair system gene recA and recO. The statistic results showed the strains resistance to (12) C ion beams radiation is partially due to the increase of gene expression index of recA and recO. In conclusion, our research provide a surrogate system to monitor the live microbial response in resistant to space radiation environment.

  16. Measurement of neutron and charged particle contamination in high energy medical therapy x-ray beams using recoil track registration in polycarbonate foils

    SciTech Connect

    Sanders, M. E.; Morgan, K. Z.; McGinley, P. H.

    1980-01-01

    The production of photoneutrons and high-energy charged particles by betatrons and linear accelerators used in radiotherapy is measured. It is concluded there exists sufficient contamination in high-energy x-ray beams to be a consideration in certain radiotherapy situations. (ACR)

  17. Observation of Energy Dependent Charge States in Impulsive Solar Energetic Particle Events with ACE SEPICA and Implications on Source Conditions and Transport

    NASA Astrophysics Data System (ADS)

    Guo, Z.; Moebius, E.; Difabio, R.; Klecker, B.; Kartavykh, J.; Mason, G.; Droege, W.; Kucharek, H.; Popecki, M.

    2008-05-01

    The ionic charge states of Solar Energetic Particle (SEP) events provide information both about the plasma environment of the flare site and the propagation process of the energetic particles. We have performed a survey of the charge state behavior for impulsive flare-related SEP events with ACE SEPICA from 1998 through 2000. This event set has been selected by eliminating all CME and shock-related events, out of which two thirds showed a short time injection with recognizable energy dispersion, an independent sign for impulsive events. However, all events in this survey also showed a strong energy dependence of the ionic charge state of heavy ions, most pronounced for iron. Based on the finding that this energy dependence is very similar for all events with and without obvious injection, we then expanded the database to all events with a charge state increase for iron by at least 2.5 units, within the energy range from 0.06 to 0.54 Mev/nuc. For the combined set of 34 impulsive events we find that the source temperature is constrained by the lowest energy charge state to 1-3 million K. In combination with models on interplanetary propagation, including scattering, convection and adiabatic deceleration, a systematic study of the observed Fe charge state behavior is consistent with a range of mean free path lengths of 0.1 - 1 AU for these energetic particles. Further implications on the propagation and acceleration conditions are discussed.

  18. Charged spinning black holes as particle accelerators

    SciTech Connect

    Wei Shaowen; Liu Yuxiao; Guo Heng; Fu Chune

    2010-11-15

    It has recently been pointed out that the spinning Kerr black hole with maximal spin could act as a particle collider with arbitrarily high center-of-mass energy. In this paper, we will extend the result to the charged spinning black hole, the Kerr-Newman black hole. The center-of-mass energy of collision for two uncharged particles falling freely from rest at infinity depends not only on the spin a but also on the charge Q of the black hole. We find that an unlimited center-of-mass energy can be approached with the conditions: (1) the collision takes place at the horizon of an extremal black hole; (2) one of the colliding particles has critical angular momentum; (3) the spin a of the extremal black hole satisfies (1/{radical}(3)){<=}(a/M){<=}1, where M is the mass of the Kerr-Newman black hole. The third condition implies that to obtain an arbitrarily high energy, the extremal Kerr-Newman black hole must have a large value of spin, which is a significant difference between the Kerr and Kerr-Newman black holes. Furthermore, we also show that, for a near-extremal black hole, there always exists a finite upper bound for center-of-mass energy, which decreases with the increase of the charge Q.

  19. Contribution of High Charge and Energy (HZE) Ions During Solar-Particle Event of September 29, 1989

    NASA Technical Reports Server (NTRS)

    Kim, Myung-Hee Y.; Wilson, John W.; Cucinotta, Francis A.; Simonsen, Lisa C.; Atwell, William; Badavi, Francis F.; Miller, Jack

    1999-01-01

    The solar-particle event (SPE) of September 29, 1989, produced an iron-rich spectrum with energies approaching 1 A GeV with an approximate spectral slope parameter of 2.5. These high charge and energy (HZE) ions challenge conventional methods of shield design and assessment of astronaut risks. In the past, shield design and risk assessment have relied on proton shielding codes and biological response models derived from X-ray and neutron exposure data. Because the HZE spectra decline rapidly with energy and HZE attenuation in materials is limited by their penetration power, details of the mass distributions about the sensitive tissues (shielding materials and the astronaut's body) are important determining factors of the exposure levels and distributions of linear energy transfer. Local tissue environments during the SPE of September 29, 1989, with its f= components are examined to analyze the importance of these ions to human SPE exposure. Typical space suit and lightly shielded structures leave significant contributions from HZE components to certain critical body tissues and have important implications on the models for risk assessment. A heavily shielded equipment room of a space vehicle or habitat requires knowledge of the breakup of these ions into lighter components, including neutrons, for shield design specifications.

  20. Circular, confined distribution for charged particle beams

    DOEpatents

    Garnett, R.W.; Dobelbower, M.C.

    1995-11-21

    A charged particle beam line is formed with magnetic optics that manipulate the charged particle beam to form the beam having a generally rectangular configuration to a circular beam cross-section having a uniform particle distribution at a predetermined location. First magnetic optics form a charged particle beam to a generally uniform particle distribution over a square planar area at a known first location. Second magnetic optics receive the charged particle beam with the generally square configuration and affect the charged particle beam to output the charged particle beam with a phase-space distribution effective to fold corner portions of the beam toward the core region of the beam. The beam forms a circular configuration having a generally uniform spatial particle distribution over a target area at a predetermined second location. 26 figs.

  1. Circular, confined distribution for charged particle beams

    DOEpatents

    Garnett, Robert W.; Dobelbower, M. Christian

    1995-01-01

    A charged particle beam line is formed with magnetic optics that manipulate the charged particle beam to form the beam having a generally rectangular configuration to a circular beam cross-section having a uniform particle distribution at a predetermined location. First magnetic optics form a charged particle beam to a generally uniform particle distribution over a square planar area at a known first location. Second magnetic optics receive the charged particle beam with the generally square configuration and affect the charged particle beam to output the charged particle beam with a phase-space distribution effective to fold corner portions of the beam toward the core region of the beam. The beam forms a circular configuration having a generally uniform spatial particle distribution over a target area at a predetermined second location.

  2. Study of dust particle charging in weakly ionized inert gases taking into account the nonlocality of the electron energy distribution function

    SciTech Connect

    Filippov, A. V. Dyatko, N. A.; Kostenko, A. S.

    2014-11-15

    The charging of dust particles in weakly ionized inert gases at atmospheric pressure has been investigated. The conditions under which the gas is ionized by an external source, a beam of fast electrons, are considered. The electron energy distribution function in argon, krypton, and xenon has been calculated for three rates of gas ionization by fast electrons: 10{sup 13}, 10{sup 14}, and 10{sup 15} cm{sup −1}. A model of dust particle charging with allowance for the nonlocal formation of the electron energy distribution function in the region of strong plasma quasi-neutrality violation around the dust particle is described. The nonlocality is taken into account in an approximation where the distribution function is a function of only the total electron energy. Comparative calculations of the dust particle charge with and without allowance for the nonlocality of the electron energy distribution function have been performed. Allowance for the nonlocality is shown to lead to a noticeable increase in the dust particle charge due to the influence of the group of hot electrons from the tail of the distribution function. It has been established that the screening constant virtually coincides with the smallest screening constant determined according to the asymptotic theory of screening with the electron transport and recombination coefficients in an unperturbed plasma.

  3. Charged particles in curved space-time

    NASA Astrophysics Data System (ADS)

    Mehdizadeh, K.; Jalili, O.

    2016-03-01

    Considering the dynamics of geometry and the matter fields, dynamical equations of geometry and the matter fields are re-derived. The solutions of these equations are studied. We focus on a charged particle and explain the axiomatic approach to drive the electromagnetic self-force on its motion, then the energy conservation is considered. A new mathematical concept, which is introduced in axiomatic approach in general, is discussed.

  4. Controlling Charged Particles with Inhomogeneous Electrostatic Fields

    NASA Technical Reports Server (NTRS)

    Herrero, Federico A. (Inventor)

    2016-01-01

    An energy analyzer for a charged-particle spectrometer may include a top deflection plate and a bottom deflection plate. The top and bottom deflection plates may be non-symmetric and configured to generate an inhomogeneous electrostatic field when a voltage is applied to one of the top or bottom deflection plates. In some instances, the top and bottom deflection plates may be L-shaped deflection plates.

  5. Core-ion temperature measurement of the ADITYA tokamak using passive charge exchange neutral particle energy analyzer

    SciTech Connect

    Pandya, Santosh P.; Ajay, Kumar; Mishra, Priyanka; Dhingra, Rajani D.; Govindarajan, J.

    2013-02-15

    Core-ion temperature measurements have been carried out by the energy analysis of passive charge exchange (CX) neutrals escaping out of the ADITYA tokamak plasma (minor radius, a= 25 cm and major radius, R= 75 cm) using a 45 Degree-Sign parallel plate electrostatic energy analyzer. The neutral particle analyzer (NPA) uses a gas cell configuration for re-ionizing the CX-neutrals and channel electron multipliers (CEMs) as detectors. Energy calibration of the NPA has been carried out using ion-source and {Delta}E/E of high-energy channel has been found to be {approx}10%. Low signal to noise ratio (SNR) due to VUV reflections on the CEMs was identified during the operation of the NPA with ADITYA plasma discharges. This problem was rectified by upgrading the system by incorporating the additional components and arrangements to suppress VUV radiations and improve its VUV rejection capabilities. The noise rejection capability of the NPA was experimentally confirmed using a standard UV-source and also during the plasma discharges to get an adequate SNR (>30) at the energy channels. Core-ion temperature T{sub i}(0) during flattop of the plasma current has been measured to be up to 150 eV during ohmically heated plasma discharges which is nearly 40% of the average core-electron temperature (typically T{sub e}(0) {approx} 400 eV). The present paper describes the principle of tokamak ion temperature measurement, NPA's design, development, and calibration along with the modifications carried out for minimizing the interference of plasma radiations in the CX-spectrum. Performance of the NPA during plasma discharges and experimental results on the measurement of ion-temperature have also been reported here.

  6. Optically stimulated luminescence and thermoluminescence efficiencies for high-energy heavy charged particle irradiation in Al2O3:C

    NASA Technical Reports Server (NTRS)

    Yukihara, E. G.; Gaza, R.; McKeever, S. W. S.; Soares, C. G.

    2004-01-01

    The thermally and optically stimulated luminescence (TL and OSL) response to high energy heavy-charged particles (HCPs) was investigated for two types of Al2O3:C luminescence dosimeters. The OSL signal was measured in both continuous-wave (CW) and pulsed mode. The efficiencies of the HCPs at producing TL or OSL, relative to gamma radiation, were obtained using four different HCPs beams (150 MeV/u 4He, 400 MeV/u 12C, 490 MeV/u 28Si, and 500 MeV/u 56Fe). The efficiencies were determined as a function of the HCP linear energy transfer (LET). It was observed that the efficiency depends on the type of detector, measurement technique, and the choice of signal. Additionally, it is shown that the shape of the CW-OSL decay curve from Al2O3:C depends on the type of radiation, and, in principle, this can be used to extract information concerning the LET of an unknown radiation field. The response of the dosimeters to low-LET radiation was also investigated for doses in the range from about 1-1000 Gy. These data were used to explain the different efficiency values obtained for the different materials and techniques, as well as the LET dependence of the CW-OSL decay curve shape. c2003 Elsevier Ltd. All rights reserved.

  7. Particle accelerator employing transient space charge potentials

    DOEpatents

    Post, Richard F.

    1990-01-01

    The invention provides an accelerator for ions and charged particles. The plasma is generated and confined in a magnetic mirror field. The electrons of the plasma are heated to high temperatures. A series of local coils are placed along the axis of the magnetic mirror field. As an ion or particle beam is directed along the axis in sequence the coils are rapidly pulsed creating a space charge to accelerate and focus the beam of ions or charged particles.

  8. Effects of Charged Particles on Human Tumor Cells

    PubMed Central

    Held, Kathryn D.; Kawamura, Hidemasa; Kaminuma, Takuya; Paz, Athena Evalour S.; Yoshida, Yukari; Liu, Qi; Willers, Henning; Takahashi, Akihisa

    2016-01-01

    The use of charged particle therapy in cancer treatment is growing rapidly, in large part because the exquisite dose localization of charged particles allows for higher radiation doses to be given to tumor tissue while normal tissues are exposed to lower doses and decreased volumes of normal tissues are irradiated. In addition, charged particles heavier than protons have substantial potential clinical advantages because of their additional biological effects, including greater cell killing effectiveness, decreased radiation resistance of hypoxic cells in tumors, and reduced cell cycle dependence of radiation response. These biological advantages depend on many factors, such as endpoint, cell or tissue type, dose, dose rate or fractionation, charged particle type and energy, and oxygen concentration. This review summarizes the unique biological advantages of charged particle therapy and highlights recent research and areas of particular research needs, such as quantification of relative biological effectiveness (RBE) for various tumor types and radiation qualities, role of genetic background of tumor cells in determining response to charged particles, sensitivity of cancer stem-like cells to charged particles, role of charged particles in tumors with hypoxic fractions, and importance of fractionation, including use of hypofractionation, with charged particles. PMID:26904502

  9. Apparatus for measuring charged particle beam

    NASA Technical Reports Server (NTRS)

    Gregory, D. A.; Stocks, C. D. (Inventor)

    1984-01-01

    An apparatus to measure the incident charged particle beam flux while effectively eliminating losses to reflection and/or secondary emission of the charged particle beam being measured is described. It comprises a sense cup through which the charged particle beam enters. A sense cone forms the rear wall of the interior chamber with the cone apex adjacent the entry opening. An outer case surrounds the sense cup and is electrically insulated therefrom. Charged particles entering the interior chamber are trapped and are absorbed by the sense cup and cone and travel through a current measuring device to ground.

  10. The joint NASA/Goddard-University of Maryland research program in charged particle and high energy photon detector technology

    NASA Technical Reports Server (NTRS)

    1986-01-01

    Progress made in the following areas is discussed: low energy ion and electron experiments; instrument design for current experiments; magnetospheric measurement of particles; ion measurement in the earth plasma sheet; abundance measurement; X-ray data acquisition; high energy physics; extragalactic astronomy; compact object astrophysics; planetology; and high energy photon detector technology.

  11. Charged-particle telescope experiment on Clementine.

    PubMed

    Baker, D N; Kanekal, S; Blake, J B; Adams, J H

    1995-01-01

    The charged-particle telescope (CPT) onboard the Clementine spacecraft measured the fluxes of energetic protons emitted in solar energetic particle events. Protons in the energy range from 10 to 80 MeV were of greatest interest for radiation effects such as total dose and single event upsets. Energetic electrons were also of interest for spacecraft charging and their contribution to total dose. The lower-energy CPT electron channels (25-500 keV) were mainly of geophysical interest. While orbiting the moon, the CPT observed the wake created by the moon when it blocked the flow of energetic particles in the magnetotail region. The CPT provided opportunities to observe energetic electron bursts during magnetic storms and magnetospheric substorms. CPT data are particularly useful in multispacecraft studies of interplanetary disturbances and their interaction with the magnetosphere. The proton channels on the CPT provided data on solar energetic protons and storm-time protons associated with the passage of an interplanetary shock at 0903 UT on Feb. 21, 1994. Results are compared with those from GOES-7, SAMPEX, and GEOTAIL.

  12. Antihydrogen (\\overline{H}) and muonic antihydrogen (\\overline{H}_{\\mu }) formation in low energy three-charge-particle collisions

    NASA Astrophysics Data System (ADS)

    Sultanov, Renat A.; Guster, D.

    2013-11-01

    A few-body formalism is applied for computation of two different three-charge-particle systems. The first system is a collision of a slow antiproton, \\overline{p}, with a positronium atom: Ps=(e+e-)—a bound state of an electron and a positron. The second problem is a collision of \\overline{p} with a muonic muonium atom, i.e. true muonium—a bound state of two muons one positive and one negative: Psμ = (μ+μ-). The total cross section of the following two reactions: \\overlinep+(e^+e^-) \\rightarrow \\overline{H} + e^- and \\overlinep+(\\mu ^+\\mu ^-) \\rightarrow \\overline{H}_{\\mu } + \\mu ^-, where \\overline{H}=(\\overlinepe^+) is antihydrogen and \\overline{H}_{\\mu }=(\\overlinep\\mu ^+) is a muonic antihydrogen atom, i.e. a bound state of \\overline{p} and μ+, are computed in the framework of a set of coupled two-component Faddeev-Hahn-type (FH-type) equations. Unlike the original Faddeev approach the FH-type equations are formulated in terms of only two but relevant components: Ψ1 and Ψ2, of the system's three-body wave function Ψ, where Ψ = Ψ1 + Ψ2. In order to solve the FH-type equations Ψ1 is expanded in terms of the input channel target eigenfunctions, i.e. in this work in terms of, for example, the (μ+μ-) atom eigenfunctions. At the same time Ψ2 is expanded in terms of the output channel two-body wave functions, that is in terms of \\overline{H}_{\\mu } atom eigenfunctions. Additionally, a convenient total angular momentum projection is performed. Results for better known low energy μ- transfer reactions from one hydrogen isotope to another hydrogen isotope in the cycle of muon catalyzed fusion (μCF) are also computed and presented.

  13. Analysis of linear energy transfers and quality factors of charged particles produced by spontaneous fission neutrons from 252Cf and 244Pu in the human body.

    PubMed

    Endo, Akira; Sato, Tatsuhiko

    2013-04-01

    Absorbed doses, linear energy transfers (LETs) and quality factors of secondary charged particles in organs and tissues, generated via the interactions of the spontaneous fission neutrons from (252)Cf and (244)Pu within the human body, were studied using the Particle and Heavy Ion Transport Code System (PHITS) coupled with the ICRP Reference Phantom. Both the absorbed doses and the quality factors in target organs generally decrease with increasing distance from the source organ. The analysis of LET distributions of secondary charged particles led to the identification of the relationship between LET spectra and target-source organ locations. A comparison between human body-averaged mean quality factors and fluence-averaged radiation weighting factors showed that the current numerical conventions for the radiation weighting factors of neutrons, updated in ICRP103, and the quality factors for internal exposure are valid.

  14. Charge injection into small semiconductor particles

    SciTech Connect

    Lawless, D.; Luangdilok, C.; Cook, A.R.; Meisel, D.

    1995-06-01

    We report on the effect of the injection of electrons into small CdS particles on their spectroscopy. Solvated electrons were generated pulse radiolytically and their reaction with the particles was monitored. As a result of the excess charge, the absorption by the particle in the exciton region is bleached. The bleaching tacks the shift in band edge as the particle size decreases. However, excess electrons in larger particles are more efficient tan in small particles. It is concluded that the effort originates in the electric field effect generated by the excess charge.

  15. Electronically shielded solid state charged particle detector

    DOEpatents

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

    1996-08-20

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

  16. Electronically shielded solid state charged particle detector

    DOEpatents

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

    1996-08-20

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

  17. Search for metastable heavy charged particles with large ionization energy loss in p p collisions at √{s }=13 TeV using the ATLAS experiment

    NASA Astrophysics Data System (ADS)

    Aaboud, M.; Aad, G.; Abbott, B.; Abdallah, J.; Abdinov, O.; Abeloos, B.; Aben, R.; Abouzeid, O. S.; Abraham, N. L.; Abramowicz, H.; Abreu, H.; Abreu, R.; Abulaiti, Y.; Acharya, B. S.; Adamczyk, L.; Adams, D. L.; Adelman, J.; Adomeit, S.; Adye, T.; Affolder, A. A.; Agatonovic-Jovin, T.; Agricola, J.; Aguilar-Saavedra, J. A.; Ahlen, S. P.; Ahmadov, F.; Aielli, G.; Akerstedt, H.; Åkesson, T. P. A.; Akimov, A. V.; Alberghi, G. L.; Albert, J.; Albrand, S.; Alconada Verzini, M. J.; Aleksa, M.; Aleksandrov, I. N.; Alexa, C.; Alexander, G.; Alexopoulos, T.; Alhroob, M.; Aliev, M.; Alimonti, G.; Alison, J.; Alkire, S. P.; Allbrooke, B. M. M.; Allen, B. W.; Allport, P. P.; Aloisio, A.; Alonso, A.; Alonso, F.; Alpigiani, C.; Alstaty, M.; Alvarez Gonzalez, B.; Álvarez Piqueras, D.; Alviggi, M. G.; Amadio, B. T.; Amako, K.; Amaral Coutinho, Y.; Amelung, C.; Amidei, D.; Amor Dos Santos, S. P.; Amorim, A.; Amoroso, S.; Amundsen, G.; Anastopoulos, C.; Ancu, L. S.; Andari, N.; Andeen, T.; Anders, C. F.; Anders, G.; Anders, J. K.; Anderson, K. J.; Andreazza, A.; Andrei, V.; Angelidakis, S.; Angelozzi, I.; Anger, P.; Angerami, A.; Anghinolfi, F.; Anisenkov, A. V.; Anjos, N.; Annovi, A.; Antonelli, M.; Antonov, A.; Anulli, F.; Aoki, M.; Aperio Bella, L.; Arabidze, G.; Arai, Y.; Araque, J. P.; Arce, A. T. H.; Arduh, F. A.; Arguin, J.-F.; Argyropoulos, S.; Arik, M.; Armbruster, A. J.; Armitage, L. J.; Arnaez, O.; Arnold, H.; Arratia, M.; Arslan, O.; Artamonov, A.; Artoni, G.; Artz, S.; Asai, S.; Asbah, N.; Ashkenazi, A.; Åsman, B.; Asquith, L.; Assamagan, K.; Astalos, R.; Atkinson, M.; Atlay, N. B.; Augsten, K.; Avolio, G.; Axen, B.; Ayoub, M. K.; Azuelos, G.; Baak, M. A.; Baas, A. E.; Baca, M. J.; Bachacou, H.; Bachas, K.; Backes, M.; Backhaus, M.; Bagiacchi, P.; Bagnaia, P.; Bai, Y.; Baines, J. T.; Baker, O. K.; Baldin, E. M.; Balek, P.; Balestri, T.; Balli, F.; Balunas, W. K.; Banas, E.; Banerjee, Sw.; Bannoura, A. A. E.; Barak, L.; Barberio, E. L.; Barberis, D.; Barbero, M.; Barillari, T.; Barklow, T.; Barlow, N.; Barnes, S. L.; Barnett, B. M.; Barnett, R. M.; Barnovska, Z.; Baroncelli, A.; Barone, G.; Barr, A. J.; Barranco Navarro, L.; Barreiro, F.; Barreiro Guimarães da Costa, J.; Bartoldus, R.; Barton, A. E.; Bartos, P.; Basalaev, A.; Bassalat, A.; Bates, R. L.; Batista, S. J.; Batley, J. R.; Battaglia, M.; Bauce, M.; Bauer, F.; Bawa, H. S.; Beacham, J. B.; Beattie, M. D.; Beau, T.; Beauchemin, P. H.; Bechtle, P.; Beck, H. P.; Becker, K.; Becker, M.; Beckingham, M.; Becot, C.; Beddall, A. J.; Beddall, A.; Bednyakov, V. A.; Bedognetti, M.; Bee, C. P.; Beemster, L. J.; Beermann, T. A.; Begel, M.; Behr, J. K.; Belanger-Champagne, C.; Bell, A. S.; Bella, G.; Bellagamba, L.; Bellerive, A.; Bellomo, M.; Belotskiy, K.; Beltramello, O.; Belyaev, N. L.; Benary, O.; Benchekroun, D.; Bender, M.; Bendtz, K.; Benekos, N.; Benhammou, Y.; Benhar Noccioli, E.; Benitez, J.; Benjamin, D. P.; Bensinger, J. R.; Bentvelsen, S.; Beresford, L.; Beretta, M.; Berge, D.; Bergeaas Kuutmann, E.; Berger, N.; Beringer, J.; Berlendis, S.; Bernard, N. R.; Bernius, C.; Bernlochner, F. U.; Berry, T.; Berta, P.; Bertella, C.; Bertoli, G.; Bertolucci, F.; Bertram, I. A.; Bertsche, C.; Bertsche, D.; Besjes, G. J.; Bessidskaia Bylund, O.; Bessner, M.; Besson, N.; Betancourt, C.; Bethke, S.; Bevan, A. J.; Bhimji, W.; Bianchi, R. M.; Bianchini, L.; Bianco, M.; Biebel, O.; Biedermann, D.; Bielski, R.; Biesuz, N. V.; Biglietti, M.; Bilbao de Mendizabal, J.; Bilokon, H.; Bindi, M.; Binet, S.; Bingul, A.; Bini, C.; Biondi, S.; Bjergaard, D. M.; Black, C. W.; Black, J. E.; Black, K. M.; Blackburn, D.; Blair, R. E.; Blanchard, J.-B.; Blanco, J. E.; Blazek, T.; Bloch, I.; Blocker, C.; Blum, W.; Blumenschein, U.; Blunier, S.; Bobbink, G. J.; Bobrovnikov, V. S.; Bocchetta, S. S.; Bocci, A.; Bock, C.; Boehler, M.; Boerner, D.; Bogaerts, J. A.; Bogavac, D.; Bogdanchikov, A. G.; Bohm, C.; Boisvert, V.; Bokan, P.; Bold, T.; Boldyrev, A. S.; Bomben, M.; Bona, M.; Boonekamp, M.; Borisov, A.; Borissov, G.; Bortfeldt, J.; Bortoletto, D.; Bortolotto, V.; Bos, K.; Boscherini, D.; Bosman, M.; Bossio Sola, J. D.; Boudreau, J.; Bouffard, J.; Bouhova-Thacker, E. V.; Boumediene, D.; Bourdarios, C.; Boutle, S. K.; Boveia, A.; Boyd, J.; Boyko, I. R.; Bracinik, J.; Brandt, A.; Brandt, G.; Brandt, O.; Bratzler, U.; Brau, B.; Brau, J. E.; Braun, H. M.; Breaden Madden, W. D.; Brendlinger, K.; Brennan, A. J.; Brenner, L.; Brenner, R.; Bressler, S.; Bristow, T. M.; Britton, D.; Britzger, D.; Brochu, F. M.; Brock, I.; Brock, R.; Brooijmans, G.; Brooks, T.; Brooks, W. K.; Brosamer, J.; Brost, E.; Broughton, J. H.; Bruckman de Renstrom, P. A.; Bruncko, D.; Bruneliere, R.; Bruni, A.; Bruni, G.; Brunt, Bh; Bruschi, M.; Bruscino, N.; Bryant, P.; Bryngemark, L.; Buanes, T.; Buat, Q.; Buchholz, P.; Buckley, A. G.; Budagov, I. A.; Buehrer, F.; Bugge, M. K.; Bulekov, O.; Bullock, D.; Burckhart, H.; Burdin, S.; Burgard, C. D.; Burghgrave, B.; Burka, K.; Burke, S.; Burmeister, I.; Busato, E.; Büscher, D.; Büscher, V.; Bussey, P.; Butler, J. M.; Buttar, C. M.; Butterworth, J. M.; Butti, P.; Buttinger, W.; Buzatu, A.; Buzykaev, A. R.; Cabrera Urbán, S.; Caforio, D.; Cairo, V. M.; Cakir, O.; Calace, N.; Calafiura, P.; Calandri, A.; Calderini, G.; Calfayan, P.; Caloba, L. P.; Calvet, D.; Calvet, S.; Calvet, T. P.; Camacho Toro, R.; Camarda, S.; Camarri, P.; Cameron, D.; Caminal Armadans, R.; Camincher, C.; Campana, S.; Campanelli, M.; Camplani, A.; Campoverde, A.; Canale, V.; Canepa, A.; Cano Bret, M.; Cantero, J.; Cantrill, R.; Cao, T.; Capeans Garrido, M. D. M.; Caprini, I.; Caprini, M.; Capua, M.; Caputo, R.; Carbone, R. M.; Cardarelli, R.; Cardillo, F.; Carli, I.; Carli, T.; Carlino, G.; Carminati, L.; Caron, S.; Carquin, E.; Carrillo-Montoya, G. D.; Carter, J. R.; Carvalho, J.; Casadei, D.; Casado, M. P.; Casolino, M.; Casper, D. W.; Castaneda-Miranda, E.; Castelijn, R.; Castelli, A.; Castillo Gimenez, V.; Castro, N. F.; Catinaccio, A.; Catmore, J. R.; Cattai, A.; Caudron, J.; Cavaliere, V.; Cavallaro, E.; Cavalli, D.; Cavalli-Sforza, M.; Cavasinni, V.; Ceradini, F.; Cerda Alberich, L.; Cerio, B. C.; Cerqueira, A. S.; Cerri, A.; Cerrito, L.; Cerutti, F.; Cerv, M.; Cervelli, A.; Cetin, S. A.; Chafaq, A.; Chakraborty, D.; Chan, S. K.; Chan, Y. L.; Chang, P.; Chapman, J. D.; Charlton, D. G.; Chatterjee, A.; Chau, C. C.; Chavez Barajas, C. A.; Che, S.; Cheatham, S.; Chegwidden, A.; Chekanov, S.; Chekulaev, S. V.; Chelkov, G. A.; Chelstowska, M. A.; Chen, C.; Chen, H.; Chen, K.; Chen, S.; Chen, S.; Chen, X.; Chen, Y.; Cheng, H. C.; Cheng, H. J.; Cheng, Y.; Cheplakov, A.; Cheremushkina, E.; Cherkaoui El Moursli, R.; Chernyatin, V.; Cheu, E.; Chevalier, L.; Chiarella, V.; Chiarelli, G.; Chiodini, G.; Chisholm, A. S.; Chitan, A.; Chizhov, M. V.; Choi, K.; Chomont, A. R.; Chouridou, S.; Chow, B. K. B.; Christodoulou, V.; Chromek-Burckhart, D.; Chudoba, J.; Chuinard, A. J.; Chwastowski, J. J.; Chytka, L.; Ciapetti, G.; Ciftci, A. K.; Cinca, D.; Cindro, V.; Cioara, I. A.; Ciocio, A.; Cirotto, F.; Citron, Z. H.; Citterio, M.; Ciubancan, M.; Clark, A.; Clark, B. L.; Clark, M. R.; Clark, P. J.; Clarke, R. N.; Clement, C.; Coadou, Y.; Cobal, M.; Coccaro, A.; Cochran, J.; Coffey, L.; Colasurdo, L.; Cole, B.; Colijn, A. P.; Collot, J.; Colombo, T.; Compostella, G.; Conde Muiño, P.; Coniavitis, E.; Connell, S. H.; Connelly, I. A.; Consorti, V.; Constantinescu, S.; Conti, G.; Conventi, F.; Cooke, M.; Cooper, B. D.; Cooper-Sarkar, A. M.; Cormier, K. J. R.; Cornelissen, T.; Corradi, M.; Corriveau, F.; Corso-Radu, A.; Cortes-Gonzalez, A.; Cortiana, G.; Costa, G.; Costa, M. J.; Costanzo, D.; Cottin, G.; Cowan, G.; Cox, B. E.; Cranmer, K.; Crawley, S. J.; Cree, G.; Crépé-Renaudin, S.; Crescioli, F.; Cribbs, W. A.; Crispin Ortuzar, M.; Cristinziani, M.; Croft, V.; Crosetti, G.; Cuhadar Donszelmann, T.; Cummings, J.; Curatolo, M.; Cúth, J.; Cuthbert, C.; Czirr, H.; Czodrowski, P.; D'Amen, G.; D'Auria, S.; D'Onofrio, M.; da Cunha Sargedas de Sousa, M. J.; da Via, C.; Dabrowski, W.; Dado, T.; Dai, T.; Dale, O.; Dallaire, F.; Dallapiccola, C.; Dam, M.; Dandoy, J. R.; Dang, N. P.; Daniells, A. C.; Dann, N. S.; Danninger, M.; Dano Hoffmann, M.; Dao, V.; Darbo, G.; Darmora, S.; Dassoulas, J.; Dattagupta, A.; Davey, W.; David, C.; Davidek, T.; Davies, M.; Davison, P.; Dawe, E.; Dawson, I.; Daya-Ishmukhametova, R. K.; de, K.; de Asmundis, R.; de Benedetti, A.; de Castro, S.; de Cecco, S.; de Groot, N.; de Jong, P.; de la Torre, H.; de Lorenzi, F.; de Maria, A.; de Pedis, D.; de Salvo, A.; de Sanctis, U.; de Santo, A.; de Vivie de Regie, J. B.; Dearnaley, W. J.; Debbe, R.; Debenedetti, C.; Dedovich, D. V.; Dehghanian, N.; Deigaard, I.; Del Gaudio, M.; Del Peso, J.; Del Prete, T.; Delgove, D.; Deliot, F.; Delitzsch, C. M.; Deliyergiyev, M.; Dell'Acqua, A.; Dell'Asta, L.; Dell'Orso, M.; Della Pietra, M.; Della Volpe, D.; Delmastro, M.; Delsart, P. A.; Deluca, C.; Demarco, D. A.; Demers, S.; Demichev, M.; Demilly, A.; Denisov, S. P.; Denysiuk, D.; Derendarz, D.; Derkaoui, J. E.; Derue, F.; Dervan, P.; Desch, K.; Deterre, C.; Dette, K.; Deviveiros, P. O.; Dewhurst, A.; Dhaliwal, S.; di Ciaccio, A.; di Ciaccio, L.; di Clemente, W. K.; di Donato, C.; di Girolamo, A.; di Girolamo, B.; di Micco, B.; di Nardo, R.; di Simone, A.; di Sipio, R.; di Valentino, D.; Diaconu, C.; Diamond, M.; Dias, F. A.; Diaz, M. A.; Diehl, E. B.; Dietrich, J.; Diglio, S.; Dimitrievska, A.; Dingfelder, J.; Dita, P.; Dita, S.; Dittus, F.; Djama, F.; Djobava, T.; Djuvsland, J. I.; Do Vale, M. A. B.; Dobos, D.; Dobre, M.; Doglioni, C.; Dohmae, T.; Dolejsi, J.; Dolezal, Z.; Dolgoshein, B. A.; Donadelli, M.; Donati, S.; Dondero, P.; Donini, J.; Dopke, J.; Doria, A.; Dova, M. T.; Doyle, A. T.; Drechsler, E.; Dris, M.; Du, Y.; Duarte-Campderros, J.; Duchovni, E.; Duckeck, G.; Ducu, O. A.; Duda, D.; Dudarev, A.; Duffield, E. M.; Duflot, L.; Duguid, L.; Dührssen, M.; Dumancic, M.; Dunford, M.; Duran Yildiz, H.; Düren, M.; Durglishvili, A.; Duschinger, D.; Dutta, B.; Dyndal, M.; Eckardt, C.; Ecker, K. M.; Edgar, R. C.; Edwards, N. C.; Eifert, T.; Eigen, G.; Einsweiler, K.; Ekelof, T.; El Kacimi, M.; Ellajosyula, V.; Ellert, M.; Elles, S.; Ellinghaus, F.; Elliot, A. A.; Ellis, N.; Elmsheuser, J.; Elsing, M.; Emeliyanov, D.; Enari, Y.; Endner, O. C.; Endo, M.; Ennis, J. S.; Erdmann, J.; Ereditato, A.; Ernis, G.; Ernst, J.; Ernst, M.; Errede, S.; Ertel, E.; Escalier, M.; Esch, H.; Escobar, C.; Esposito, B.; Etienvre, A. I.; Etzion, E.; Evans, H.; Ezhilov, A.; Fabbri, F.; Fabbri, L.; Facini, G.; Fakhrutdinov, R. M.; Falciano, S.; Falla, R. J.; Faltova, J.; Fang, Y.; Fanti, M.; Farbin, A.; Farilla, A.; Farina, C.; Farooque, T.; Farrell, S.; Farrington, S. M.; Farthouat, P.; Fassi, F.; Fassnacht, P.; Fassouliotis, D.; Faucci Giannelli, M.; Favareto, A.; Fawcett, W. J.; Fayard, L.; Fedin, O. L.; Fedorko, W.; Feigl, S.; Feligioni, L.; Feng, C.; Feng, E. J.; Feng, H.; Fenyuk, A. B.; Feremenga, L.; Fernandez Martinez, P.; Fernandez Perez, S.; Ferrando, J.; Ferrari, A.; Ferrari, P.; Ferrari, R.; Ferreira de Lima, D. E.; Ferrer, A.; Ferrere, D.; Ferretti, C.; Ferretto Parodi, A.; Fiedler, F.; Filipčič, A.; Filipuzzi, M.; Filthaut, F.; Fincke-Keeler, M.; Finelli, K. D.; Fiolhais, M. C. N.; Fiorini, L.; Firan, A.; Fischer, A.; Fischer, C.; Fischer, J.; Fisher, W. C.; Flaschel, N.; Fleck, I.; Fleischmann, P.; Fletcher, G. T.; Fletcher, R. R. M.; Flick, T.; Floderus, A.; Flores Castillo, L. R.; Flowerdew, M. J.; Forcolin, G. T.; Formica, A.; Forti, A.; Foster, A. G.; Fournier, D.; Fox, H.; Fracchia, S.; Francavilla, P.; Franchini, M.; Francis, D.; Franconi, L.; Franklin, M.; Frate, M.; Fraternali, M.; Freeborn, D.; Fressard-Batraneanu, S. M.; Friedrich, F.; Froidevaux, D.; Frost, J. A.; Fukunaga, C.; Fullana Torregrosa, E.; Fusayasu, T.; Fuster, J.; Gabaldon, C.; Gabizon, O.; Gabrielli, A.; Gabrielli, A.; Gach, G. P.; Gadatsch, S.; Gadomski, S.; Gagliardi, G.; Gagnon, L. G.; Gagnon, P.; Galea, C.; Galhardo, B.; Gallas, E. J.; Gallop, B. J.; Gallus, P.; Galster, G.; Gan, K. K.; Gao, J.; Gao, Y.; Gao, Y. S.; Garay Walls, F. M.; García, C.; García Navarro, J. E.; Garcia-Sciveres, M.; Gardner, R. W.; Garelli, N.; Garonne, V.; Gascon Bravo, A.; Gatti, C.; Gaudiello, A.; Gaudio, G.; Gaur, B.; Gauthier, L.; Gavrilenko, I. L.; Gay, C.; Gaycken, G.; Gazis, E. N.; Gecse, Z.; Gee, C. N. P.; Geich-Gimbel, Ch.; Geisen, M.; Geisler, M. P.; Gemme, C.; Genest, M. H.; Geng, C.; Gentile, S.; George, S.; Gerbaudo, D.; Gershon, A.; Ghasemi, S.; Ghazlane, H.; Ghneimat, M.; Giacobbe, B.; Giagu, S.; Giannetti, P.; Gibbard, B.; Gibson, S. M.; Gignac, M.; Gilchriese, M.; Gillam, T. P. S.; Gillberg, D.; Gilles, G.; Gingrich, D. M.; Giokaris, N.; Giordani, M. P.; Giorgi, F. M.; Giorgi, F. M.; Giraud, P. F.; Giromini, P.; Giugni, D.; Giuli, F.; Giuliani, C.; Giulini, M.; Gjelsten, B. K.; Gkaitatzis, S.; Gkialas, I.; Gkougkousis, E. L.; Gladilin, L. K.; Glasman, C.; Glatzer, J.; Glaysher, P. C. F.; Glazov, A.; Goblirsch-Kolb, M.; Godlewski, J.; Goldfarb, S.; Golling, T.; Golubkov, D.; Gomes, A.; Gonçalo, R.; Goncalves Pinto Firmino da Costa, J.; Gonella, G.; Gonella, L.; Gongadze, A.; González de La Hoz, S.; Gonzalez Parra, G.; Gonzalez-Sevilla, S.; Goossens, L.; Gorbounov, P. A.; Gordon, H. A.; Gorelov, I.; Gorini, B.; Gorini, E.; Gorišek, A.; Gornicki, E.; Goshaw, A. T.; Gössling, C.; Gostkin, M. I.; Goudet, C. R.; Goujdami, D.; Goussiou, A. G.; Govender, N.; Gozani, E.; Graber, L.; Grabowska-Bold, I.; Gradin, P. O. J.; Grafström, P.; Gramling, J.; Gramstad, E.; Grancagnolo, S.; Gratchev, V.; Gravila, P. M.; Gray, H. M.; Graziani, E.; Greenwood, Z. D.; Grefe, C.; Gregersen, K.; Gregor, I. M.; Grenier, P.; Grevtsov, K.; Griffiths, J.; Grillo, A. A.; Grimm, K.; Grinstein, S.; Gris, Ph.; Grivaz, J.-F.; Groh, S.; Grohs, J. P.; Gross, E.; Grosse-Knetter, J.; Grossi, G. C.; Grout, Z. J.; Guan, L.; Guan, W.; Guenther, J.; Guescini, F.; Guest, D.; Gueta, O.; Guido, E.; Guillemin, T.; Guindon, S.; Gul, U.; Gumpert, C.; Guo, J.; Guo, Y.; Gupta, S.; Gustavino, G.; Gutierrez, P.; Gutierrez Ortiz, N. G.; Gutschow, C.; Guyot, C.; Gwenlan, C.; Gwilliam, C. B.; Haas, A.; Haber, C.; Hadavand, H. K.; Haddad, N.; Hadef, A.; Haefner, P.; Hageböck, S.; Hajduk, Z.; Hakobyan, H.; Haleem, M.; Haley, J.; Halladjian, G.; Hallewell, G. D.; Hamacher, K.; Hamal, P.; Hamano, K.; Hamilton, A.; Hamity, G. N.; Hamnett, P. G.; Han, L.; Hanagaki, K.; Hanawa, K.; Hance, M.; Haney, B.; Hanke, P.; Hanna, R.; Hansen, J. B.; Hansen, J. D.; Hansen, M. C.; Hansen, P. H.; Hara, K.; Hard, A. S.; Harenberg, T.; Hariri, F.; Harkusha, S.; Harrington, R. D.; Harrison, P. F.; Hartjes, F.; Hartmann, N. M.; Hasegawa, M.; Hasegawa, Y.; Hasib, A.; Hassani, S.; Haug, S.; Hauser, R.; Hauswald, L.; Havranek, M.; Hawkes, C. M.; Hawkings, R. J.; Hayden, D.; Hays, C. P.; Hays, J. M.; Hayward, H. S.; Haywood, S. J.; Head, S. J.; Heck, T.; Hedberg, V.; Heelan, L.; Heim, S.; Heim, T.; Heinemann, B.; Heinrich, J. J.; Heinrich, L.; Heinz, C.; Hejbal, J.; Helary, L.; Hellman, S.; Helsens, C.; Henderson, J.; Henderson, R. C. W.; Heng, Y.; Henkelmann, S.; Henriques Correia, A. M.; Henrot-Versille, S.; Herbert, G. H.; Hernández Jiménez, Y.; Herten, G.; Hertenberger, R.; Hervas, L.; Hesketh, G. G.; Hessey, N. P.; Hetherly, J. W.; Hickling, R.; Higón-Rodriguez, E.; Hill, E.; Hill, J. C.; Hiller, K. H.; Hillier, S. J.; Hinchliffe, I.; Hines, E.; Hinman, R. R.; Hirose, M.; Hirschbuehl, D.; Hobbs, J.; Hod, N.; Hodgkinson, M. C.; Hodgson, P.; Hoecker, A.; Hoeferkamp, M. R.; Hoenig, F.; Hohn, D.; Holmes, T. R.; Homann, M.; Hong, T. M.; Hooberman, B. H.; Hopkins, W. H.; Horii, Y.; Horton, A. J.; Hostachy, J.-Y.; Hou, S.; Hoummada, A.; Howarth, J.; Hrabovsky, M.; Hristova, I.; Hrivnac, J.; Hryn'ova, T.; Hrynevich, A.; Hsu, C.; Hsu, P. J.; Hsu, S.-C.; Hu, D.; Hu, Q.; Huang, Y.; Hubacek, Z.; Hubaut, F.; Huegging, F.; Huffman, T. B.; Hughes, E. W.; Hughes, G.; Huhtinen, M.; Hülsing, T. A.; Huo, P.; Huseynov, N.; Huston, J.; Huth, J.; Iacobucci, G.; Iakovidis, G.; Ibragimov, I.; Iconomidou-Fayard, L.; Ideal, E.; Idrissi, Z.; Iengo, P.; Igonkina, O.; Iizawa, T.; Ikegami, Y.; Ikeno, M.; Ilchenko, Y.; Iliadis, D.; Ilic, N.; Ince, T.; Introzzi, G.; Ioannou, P.; Iodice, M.; Iordanidou, K.; Ippolito, V.; Ishino, M.; Ishitsuka, M.; Ishmukhametov, R.; Issever, C.; Istin, S.; Ito, F.; Iturbe Ponce, J. M.; Iuppa, R.; Iwanski, W.; Iwasaki, H.; Izen, J. M.; Izzo, V.; Jabbar, S.; Jackson, B.; Jackson, M.; Jackson, P.; Jain, V.; Jakobi, K. B.; Jakobs, K.; Jakobsen, S.; Jakoubek, T.; Jamin, D. O.; Jana, D. K.; Jansen, E.; Jansky, R.; Janssen, J.; Janus, M.; Jarlskog, G.; Javadov, N.; Javå¯Rek, T.; Jeanneau, F.; Jeanty, L.; Jejelava, J.; Jeng, G.-Y.; Jennens, D.; Jenni, P.; Jentzsch, J.; Jeske, C.; Jézéquel, S.; Ji, H.; Jia, J.; Jiang, H.; Jiang, Y.; Jiggins, S.; Jimenez Pena, J.; Jin, S.; Jinaru, A.; Jinnouchi, O.; Johansson, P.; Johns, K. A.; Johnson, W. J.; Jon-And, K.; Jones, G.; Jones, R. W. L.; Jones, S.; Jones, T. J.; Jongmanns, J.; Jorge, P. M.; Jovicevic, J.; Ju, X.; Juste Rozas, A.; Köhler, M. K.; Kaczmarska, A.; Kado, M.; Kagan, H.; Kagan, M.; Kahn, S. J.; Kajomovitz, E.; Kalderon, C. W.; Kaluza, A.; Kama, S.; Kamenshchikov, A.; Kanaya, N.; Kaneti, S.; Kanjir, L.; Kantserov, V. A.; Kanzaki, J.; Kaplan, B.; Kaplan, L. S.; Kapliy, A.; Kar, D.; Karakostas, K.; Karamaoun, A.; Karastathis, N.; Kareem, M. J.; Karentzos, E.; Karnevskiy, M.; Karpov, S. N.; Karpova, Z. M.; Karthik, K.; Kartvelishvili, V.; Karyukhin, A. N.; Kasahara, K.; Kashif, L.; Kass, R. D.; Kastanas, A.; Kataoka, Y.; Kato, C.; Katre, A.; Katzy, J.; Kawagoe, K.; Kawamoto, T.; Kawamura, G.; Kazama, S.; Kazanin, V. F.; Keeler, R.; Kehoe, R.; Keller, J. S.; Kempster, J. J.; Kentaro, K.; Keoshkerian, H.; Kepka, O.; Kerševan, B. P.; Kersten, S.; Keyes, R. A.; Khalil-Zada, F.; Khanov, A.; Kharlamov, A. G.; Khoo, T. J.; Khovanskiy, V.; Khramov, E.; Khubua, J.; Kido, S.; Kim, H. Y.; Kim, S. H.; Kim, Y. K.; Kimura, N.; Kind, O. M.; King, B. T.; King, M.; King, S. B.; Kirk, J.; Kiryunin, A. E.; Kishimoto, T.; Kisielewska, D.; Kiss, F.; Kiuchi, K.; Kivernyk, O.; Kladiva, E.; Klein, M. H.; Klein, M.; Klein, U.; Kleinknecht, K.; Klimek, P.; Klimentov, A.; Klingenberg, R.; Klinger, J. A.; Klioutchnikova, T.; Kluge, E.-E.; Kluit, P.; Kluth, S.; Knapik, J.; Kneringer, E.; Knoops, E. B. F. G.; Knue, A.; Kobayashi, A.; Kobayashi, D.; Kobayashi, T.; Kobel, M.; Kocian, M.; Kodys, P.; Koffas, T.; Koffeman, E.; Koi, T.; Kolanoski, H.; Kolb, M.; Koletsou, I.; Komar, A. A.; Komori, Y.; Kondo, T.; Kondrashova, N.; Köneke, K.; König, A. C.; Kono, T.; Konoplich, R.; Konstantinidis, N.; Kopeliansky, R.; Koperny, S.; Köpke, L.; Kopp, A. K.; Korcyl, K.; Kordas, K.; Korn, A.; Korol, A. A.; Korolkov, I.; Korolkova, E. V.; Kortner, O.; Kortner, S.; Kosek, T.; Kostyukhin, V. V.; Kotwal, A.; Kourkoumeli-Charalampidi, A.; Kourkoumelis, C.; Kouskoura, V.; Kowalewska, A. B.; Kowalewski, R.; Kowalski, T. Z.; Kozakai, C.; Kozanecki, W.; Kozhin, A. S.; Kramarenko, V. A.; Kramberger, G.; Krasnopevtsev, D.; Krasny, M. W.; Krasznahorkay, A.; Kraus, J. K.; Kravchenko, A.; Kretz, M.; Kretzschmar, J.; Kreutzfeldt, K.; Krieger, P.; Krizka, K.; Kroeninger, K.; Kroha, H.; Kroll, J.; Kroseberg, J.; Krstic, J.; Kruchonak, U.; Krüger, H.; Krumnack, N.; Kruse, A.; Kruse, M. C.; Kruskal, M.; Kubota, T.; Kucuk, H.; Kuday, S.; Kuechler, J. T.; Kuehn, S.; Kugel, A.; Kuger, F.; Kuhl, A.; Kuhl, T.; Kukhtin, V.; Kukla, R.; Kulchitsky, Y.; Kuleshov, S.; Kuna, M.; Kunigo, T.; Kupco, A.; Kurashige, H.; Kurochkin, Y. A.; Kus, V.; Kuwertz, E. S.; Kuze, M.; Kvita, J.; Kwan, T.; Kyriazopoulos, D.; La Rosa, A.; La Rosa Navarro, J. L.; La Rotonda, L.; Lacasta, C.; Lacava, F.; Lacey, J.; Lacker, H.; Lacour, D.; Lacuesta, V. R.; Ladygin, E.; Lafaye, R.; Laforge, B.; Lagouri, T.; Lai, S.; Lammers, S.; Lampl, W.; Lançon, E.; Landgraf, U.; Landon, M. P. J.; Lang, V. S.; Lange, J. C.; Lankford, A. J.; Lanni, F.; Lantzsch, K.; Lanza, A.; Laplace, S.; Lapoire, C.; Laporte, J. F.; Lari, T.; Lasagni Manghi, F.; Lassnig, M.; Laurelli, P.; Lavrijsen, W.; Law, A. T.; Laycock, P.; Lazovich, T.; Lazzaroni, M.; Le, B.; Le Dortz, O.; Le Guirriec, E.; Le Quilleuc, E. P.; Leblanc, M.; Lecompte, T.; Ledroit-Guillon, F.; Lee, C. A.; Lee, S. C.; Lee, L.; Lefebvre, G.; Lefebvre, M.; Legger, F.; Leggett, C.; Lehan, A.; Lehmann Miotto, G.; Lei, X.; Leight, W. A.; Leisos, A.; Leister, A. G.; Leite, M. A. L.; Leitner, R.; Lellouch, D.; Lemmer, B.; Leney, K. J. C.; Lenz, T.; Lenzi, B.; Leone, R.; Leone, S.; Leonidopoulos, C.; Leontsinis, S.; Lerner, G.; Leroy, C.; Lesage, A. A. J.; Lester, C. G.; Levchenko, M.; Levêque, J.; Levin, D.; Levinson, L. J.; Levy, M.; Lewis, D.; Leyko, A. M.; Leyton, M.; Li, B.; Li, H.; Li, H. L.; Li, L.; Li, L.; Li, Q.; Li, S.; Li, X.; Li, Y.; Liang, Z.; Liberti, B.; Liblong, A.; Lichard, P.; Lie, K.; Liebal, J.; Liebig, W.; Limosani, A.; Lin, S. C.; Lin, T. H.; Lindquist, B. E.; Lionti, A. E.; Lipeles, E.; Lipniacka, A.; Lisovyi, M.; Liss, T. M.; Lister, A.; Litke, A. M.; Liu, B.; Liu, D.; Liu, H.; Liu, H.; Liu, J.; Liu, J. B.; Liu, K.; Liu, L.; Liu, M.; Liu, M.; Liu, Y. L.; Liu, Y.; Livan, M.; Lleres, A.; Llorente Merino, J.; Lloyd, S. L.; Lo Sterzo, F.; Lobodzinska, E.; Loch, P.; Lockman, W. S.; Loebinger, F. K.; Loevschall-Jensen, A. E.; Loew, K. M.; Loginov, A.; Lohse, T.; Lohwasser, K.; Lokajicek, M.; Long, B. A.; Long, J. D.; Long, R. E.; Longo, L.; Looper, K. A.; Lopes, L.; Lopez Mateos, D.; Lopez Paredes, B.; Lopez Paz, I.; Lopez Solis, A.; Lorenz, J.; Lorenzo Martinez, N.; Losada, M.; Lösel, P. J.; Lou, X.; Lounis, A.; Love, J.; Love, P. A.; Lu, H.; Lu, N.; Lubatti, H. J.; Luci, C.; Lucotte, A.; Luedtke, C.; Luehring, F.; Lukas, W.; Luminari, L.; Lundberg, O.; Lund-Jensen, B.; Luzi, P. M.; Lynn, D.; Lysak, R.; Lytken, E.; Lyubushkin, V.; Ma, H.; Ma, L. L.; Ma, Y.; Maccarrone, G.; Macchiolo, A.; MacDonald, C. M.; Maček, B.; Machado Miguens, J.; Madaffari, D.; Madar, R.; Maddocks, H. J.; Mader, W. F.; Madsen, A.; Maeda, J.; Maeland, S.; Maeno, T.; Maevskiy, A.; Magradze, E.; Mahlstedt, J.; Maiani, C.; Maidantchik, C.; Maier, A. A.; Maier, T.; Maio, A.; Majewski, S.; Makida, Y.; Makovec, N.; Malaescu, B.; Malecki, Pa.; Maleev, V. P.; Malek, F.; Mallik, U.; Malon, D.; Malone, C.; Maltezos, S.; Malyukov, S.; Mamuzic, J.; Mancini, G.; Mandelli, B.; Mandelli, L.; Mandić, I.; Maneira, J.; Manhaes de Andrade Filho, L.; Manjarres Ramos, J.; Mann, A.; Manousos, A.; Mansoulie, B.; Mansour, J. D.; Mantifel, R.; Mantoani, M.; Manzoni, S.; Mapelli, L.; Marceca, G.; March, L.; Marchiori, G.; Marcisovsky, M.; Marjanovic, M.; Marley, D. E.; Marroquim, F.; Marsden, S. P.; Marshall, Z.; Marti-Garcia, S.; Martin, B.; Martin, T. A.; Martin, V. J.; Martin Dit Latour, B.; Martinez, M.; Martin-Haugh, S.; Martoiu, V. S.; Martyniuk, A. C.; Marx, M.; Marzin, A.; Masetti, L.; Mashimo, T.; Mashinistov, R.; Masik, J.; Maslennikov, A. L.; Massa, I.; Massa, L.; Mastrandrea, P.; Mastroberardino, A.; Masubuchi, T.; Mättig, P.; Mattmann, J.; Maurer, J.; Maxfield, S. J.; Maximov, D. A.; Mazini, R.; Mazza, S. M.; Mc Fadden, N. C.; Mc Goldrick, G.; Mc Kee, S. P.; McCarn, A.; McCarthy, R. L.; McCarthy, T. G.; McClymont, L. I.; McDonald, E. F.; McFarlane, K. W.; McFayden, J. A.; McHedlidze, G.; McMahon, S. J.; McPherson, R. A.; Medinnis, M.; Meehan, S.; Mehlhase, S.; Mehta, A.; Meier, K.; Meineck, C.; Meirose, B.; Melini, D.; Mellado Garcia, B. R.; Melo, M.; Meloni, F.; Mengarelli, A.; Menke, S.; Meoni, E.; Mergelmeyer, S.; Mermod, P.; Merola, L.; Meroni, C.; Merritt, F. S.; Messina, A.; Metcalfe, J.; Mete, A. S.; Meyer, C.; Meyer, C.; Meyer, J.-P.; Meyer, J.; Meyer Zu Theenhausen, H.; Miano, F.; Middleton, R. P.; Miglioranzi, S.; Mijović, L.; Mikenberg, G.; Mikestikova, M.; Mikuž, M.; Milesi, M.; Milic, A.; Miller, D. W.; Mills, C.; Milov, A.; Milstead, D. A.; Minaenko, A. A.; Minami, Y.; Minashvili, I. A.; Mincer, A. I.; Mindur, B.; Mineev, M.; Ming, Y.; Mir, L. M.; Mistry, K. P.; Mitani, T.; Mitrevski, J.; Mitsou, V. A.; Miucci, A.; Miyagawa, P. S.; Mjörnmark, J. U.; Moa, T.; Mochizuki, K.; Mohapatra, S.; Molander, S.; Moles-Valls, R.; Monden, R.; Mondragon, M. C.; Mönig, K.; Monk, J.; Monnier, E.; Montalbano, A.; Montejo Berlingen, J.; Monticelli, F.; Monzani, S.; Moore, R. W.; Morange, N.; Moreno, D.; Moreno Llácer, M.; Morettini, P.; Mori, D.; Mori, T.; Morii, M.; Morinaga, M.; Morisbak, V.; Moritz, S.; Morley, A. K.; Mornacchi, G.; Morris, J. D.; Mortensen, S. S.; Morvaj, L.; Mosidze, M.; Moss, J.; Motohashi, K.; Mount, R.; Mountricha, E.; Mouraviev, S. V.; Moyse, E. J. W.; Muanza, S.; Mudd, R. D.; Mueller, F.; Mueller, J.; Mueller, R. S. P.; Mueller, T.; Muenstermann, D.; Mullen, P.; Mullier, G. A.; Munoz Sanchez, F. J.; Murillo Quijada, J. A.; Murray, W. J.; Musheghyan, H.; Muškinja, M.; Myagkov, A. G.; Myska, M.; Nachman, B. P.; Nackenhorst, O.; Nagai, K.; Nagai, R.; Nagano, K.; Nagasaka, Y.; Nagata, K.; Nagel, M.; Nagy, E.; Nairz, A. M.; Nakahama, Y.; Nakamura, K.; Nakamura, T.; Nakano, I.; Namasivayam, H.; Naranjo Garcia, R. F.; Narayan, R.; Narrias Villar, D. I.; Naryshkin, I.; Naumann, T.; Navarro, G.; Nayyar, R.; Neal, H. A.; Nechaeva, P. Yu.; Neep, T. J.; Nef, P. D.; Negri, A.; Negrini, M.; Nektarijevic, S.; Nellist, C.; Nelson, A.; Nemecek, S.; Nemethy, P.; Nepomuceno, A. A.; Nessi, M.; Neubauer, M. S.; Neumann, M.; Neves, R. M.; Nevski, P.; Newman, P. R.; Nguyen, D. H.; Nguyen Manh, T.; Nickerson, R. B.; Nicolaidou, R.; Nielsen, J.; Nikiforov, A.; Nikolaenko, V.; Nikolic-Audit, I.; Nikolopoulos, K.; Nilsen, J. K.; Nilsson, P.; Ninomiya, Y.; Nisati, A.; Nisius, R.; Nobe, T.; Nodulman, L.; Nomachi, M.; Nomidis, I.; Nooney, T.; Norberg, S.; Nordberg, M.; Norjoharuddeen, N.; Novgorodova, O.; Nowak, S.; Nozaki, M.; Nozka, L.; Ntekas, K.; Nurse, E.; Nuti, F.; O'Grady, F.; O'Neil, D. C.; O'Rourke, A. A.; O'Shea, V.; Oakham, F. G.; Oberlack, H.; Obermann, T.; Ocariz, J.; Ochi, A.; Ochoa, I.; Ochoa-Ricoux, J. P.; Oda, S.; Odaka, S.; Ogren, H.; Oh, A.; Oh, S. H.; Ohm, C. C.; Ohman, H.; Oide, H.; Okawa, H.; Okumura, Y.; Okuyama, T.; Olariu, A.; Oleiro Seabra, L. F.; Olivares Pino, S. A.; Oliveira Damazio, D.; Olszewski, A.; Olszowska, J.; Onofre, A.; Onogi, K.; Onyisi, P. U. E.; Oreglia, M. J.; Oren, Y.; Orestano, D.; Orlando, N.; Orr, R. S.; Osculati, B.; Ospanov, R.; Otero Y Garzon, G.; Otono, H.; Ouchrif, M.; Ould-Saada, F.; Ouraou, A.; Oussoren, K. P.; Ouyang, Q.; Owen, M.; Owen, R. E.; Ozcan, V. E.; Ozturk, N.; Pachal, K.; Pacheco Pages, A.; Padilla Aranda, C.; Pagáčová, M.; Pagan Griso, S.; Paige, F.; Pais, P.; Pajchel, K.; Palacino, G.; Palestini, S.; Palka, M.; Pallin, D.; Palma, A.; Panagiotopoulou, E. St.; Pandini, C. E.; Panduro Vazquez, J. G.; Pani, P.; Panitkin, S.; Pantea, D.; Paolozzi, L.; Papadopoulou, Th. D.; Papageorgiou, K.; Paramonov, A.; Paredes Hernandez, D.; Parker, A. J.; Parker, M. A.; Parker, K. A.; Parodi, F.; Parsons, J. A.; Parzefall, U.; Pascuzzi, V. R.; Pasqualucci, E.; Passaggio, S.; Pastore, Fr.; Pásztor, G.; Pataraia, S.; Pater, J. R.; Pauly, T.; Pearce, J.; Pearson, B.; Pedersen, L. E.; Pedersen, M.; Pedraza Lopez, S.; Pedro, R.; Peleganchuk, S. V.; Pelikan, D.; Penc, O.; Peng, C.; Peng, H.; Penwell, J.; Peralva, B. S.; Perego, M. M.; Perepelitsa, D. V.; Perez Codina, E.; Perini, L.; Pernegger, H.; Perrella, S.; Peschke, R.; Peshekhonov, V. D.; Peters, K.; Peters, R. F. Y.; Petersen, B. A.; Petersen, T. C.; Petit, E.; Petridis, A.; Petridou, C.; Petroff, P.; Petrolo, E.; Petrov, M.; Petrucci, F.; Pettersson, N. E.; Peyaud, A.; Pezoa, R.; Phillips, P. W.; Piacquadio, G.; Pianori, E.; Picazio, A.; Piccaro, E.; Piccinini, M.; Pickering, M. A.; Piegaia, R.; Pilcher, J. E.; Pilkington, A. D.; Pin, A. W. J.; Pinamonti, M.; Pinfold, J. L.; Pingel, A.; Pires, S.; Pirumov, H.; Pitt, M.; Plazak, L.; Pleier, M.-A.; Pleskot, V.; Plotnikova, E.; Plucinski, P.; Pluth, D.; Poettgen, R.; Poggioli, L.; Pohl, D.; Polesello, G.; Poley, A.; Policicchio, A.; Polifka, R.; Polini, A.; Pollard, C. S.; Polychronakos, V.; Pommès, K.; Pontecorvo, L.; Pope, B. G.; Popeneciu, G. A.; Popovic, D. S.; Poppleton, A.; Pospisil, S.; Potamianos, K.; Potrap, I. N.; Potter, C. J.; Potter, C. T.; Poulard, G.; Poveda, J.; Pozdnyakov, V.; Pozo Astigarraga, M. E.; Pralavorio, P.; Pranko, A.; Prell, S.; Price, D.; Price, L. E.; Primavera, M.; Prince, S.; Proissl, M.; Prokofiev, K.; Prokoshin, F.; Protopopescu, S.; Proudfoot, J.; Przybycien, M.; Puddu, D.; Purohit, M.; Puzo, P.; Qian, J.; Qin, G.; Qin, Y.; Quadt, A.; Quayle, W. B.; Queitsch-Maitland, M.; Quilty, D.; Raddum, S.; Radeka, V.; Radescu, V.; Radhakrishnan, S. K.; Radloff, P.; Rados, P.; Ragusa, F.; Rahal, G.; Raine, J. A.; Rajagopalan, S.; Rammensee, M.; Rangel-Smith, C.; Ratti, M. G.; Rauscher, F.; Rave, S.; Ravenscroft, T.; Ravinovich, I.; Raymond, M.; Read, A. L.; Readioff, N. P.; Reale, M.; Rebuzzi, D. M.; Redelbach, A.; Redlinger, G.; Reece, R.; Reeves, K.; Rehnisch, L.; Reichert, J.; Reisin, H.; Rembser, C.; Ren, H.; Rescigno, M.; Resconi, S.; Rezanova, O. L.; Reznicek, P.; Rezvani, R.; Richter, R.; Richter, S.; Richter-Was, E.; Ricken, O.; Ridel, M.; Rieck, P.; Riegel, C. J.; Rieger, J.; Rifki, O.; Rijssenbeek, M.; Rimoldi, A.; Rimoldi, M.; Rinaldi, L.; Ristić, B.; Ritsch, E.; Riu, I.; Rizatdinova, F.; Rizvi, E.; Rizzi, C.; Robertson, S. H.; Robichaud-Veronneau, A.; Robinson, D.; Robinson, J. E. M.; Robson, A.; Roda, C.; Rodina, Y.; Rodriguez Perez, A.; Rodriguez Rodriguez, D.; Roe, S.; Rogan, C. S.; Røhne, O.; Romaniouk, A.; Romano, M.; Romano Saez, S. M.; Romero Adam, E.; Rompotis, N.; Ronzani, M.; Roos, L.; Ros, E.; Rosati, S.; Rosbach, K.; Rose, P.; Rosenthal, O.; Rosien, N.-A.; Rossetti, V.; Rossi, E.; Rossi, L. P.; Rosten, J. H. N.; Rosten, R.; Rotaru, M.; Roth, I.; Rothberg, J.; Rousseau, D.; Royon, C. R.; Rozanov, A.; Rozen, Y.; Ruan, X.; Rubbo, F.; Rudolph, M. S.; Rühr, F.; Ruiz-Martinez, A.; Rurikova, Z.; Rusakovich, N. A.; Ruschke, A.; Russell, H. L.; Rutherfoord, J. P.; Ruthmann, N.; Ryabov, Y. F.; Rybar, M.; Rybkin, G.; Ryu, S.; Ryzhov, A.; Rzehorz, G. F.; Saavedra, A. F.; Sabato, G.; Sacerdoti, S.; Sadrozinski, H. F.-W.; Sadykov, R.; Safai Tehrani, F.; Saha, P.; Sahinsoy, M.; Saimpert, M.; Saito, T.; Sakamoto, H.; Sakurai, Y.; Salamanna, G.; Salamon, A.; Salazar Loyola, J. E.; Salek, D.; Sales de Bruin, P. H.; Salihagic, D.; Salnikov, A.; Salt, J.; Salvatore, D.; Salvatore, F.; Salvucci, A.; Salzburger, A.; Sammel, D.; Sampsonidis, D.; Sanchez, A.; Sánchez, J.; Sanchez Martinez, V.; Sandaker, H.; Sandbach, R. L.; Sander, H. G.; Sandhoff, M.; Sandoval, C.; Sandstroem, R.; Sankey, D. P. C.; Sannino, M.; Sansoni, A.; Santoni, C.; Santonico, R.; Santos, H.; Santoyo Castillo, I.; Sapp, K.; Sapronov, A.; Saraiva, J. G.; Sarrazin, B.; Sasaki, O.; Sasaki, Y.; Sato, K.; Sauvage, G.; Sauvan, E.; Savage, G.; Savard, P.; Sawyer, C.; Sawyer, L.; Saxon, J.; Sbarra, C.; Sbrizzi, A.; Scanlon, T.; Scannicchio, D. A.; Scarcella, M.; Scarfone, V.; Schaarschmidt, J.; Schacht, P.; Schachtner, B. M.; Schaefer, D.; Schaefer, R.; Schaeffer, J.; Schaepe, S.; Schaetzel, S.; Schäfer, U.; Schaffer, A. C.; Schaile, D.; Schamberger, R. D.; Scharf, V.; Schegelsky, V. A.; Scheirich, D.; Schernau, M.; Schiavi, C.; Schier, S.; Schillo, C.; Schioppa, M.; Schlenker, S.; Schmidt-Sommerfeld, K. R.; Schmieden, K.; Schmitt, C.; Schmitt, S.; Schmitz, S.; Schneider, B.; Schnoor, U.; Schoeffel, L.; Schoening, A.; Schoenrock, B. D.; Schopf, E.; Schott, M.; Schovancova, J.; Schramm, S.; Schreyer, M.; Schuh, N.; Schultens, M. J.; Schultz-Coulon, H.-C.; Schulz, H.; Schumacher, M.; Schumm, B. A.; Schune, Ph.; Schwartzman, A.; Schwarz, T. A.; Schwegler, Ph.; Schweiger, H.; Schwemling, Ph.; Schwienhorst, R.; Schwindling, J.; Schwindt, T.; Sciolla, G.; Scuri, F.; Scutti, F.; Searcy, J.; Seema, P.; Seidel, S. C.; Seiden, A.; Seifert, F.; Seixas, J. M.; Sekhniaidze, G.; Sekhon, K.; Sekula, S. J.; Seliverstov, D. M.; Semprini-Cesari, N.; Serfon, C.; Serin, L.; Serkin, L.; Sessa, M.; Seuster, R.; Severini, H.; Sfiligoj, T.; Sforza, F.; Sfyrla, A.; Shabalina, E.; Shaikh, N. W.; Shan, L. Y.; Shang, R.; Shank, J. T.; Shapiro, M.; Shatalov, P. B.; Shaw, K.; Shaw, S. M.; Shcherbakova, A.; Shehu, C. Y.; Sherwood, P.; Shi, L.; Shimizu, S.; Shimmin, C. O.; Shimojima, M.; Shiyakova, M.; Shmeleva, A.; Shoaleh Saadi, D.; Shochet, M. J.; Shojaii, S.; Shrestha, S.; Shulga, E.; Shupe, M. A.; Sicho, P.; Sickles, A. M.; Sidebo, P. E.; Sidiropoulou, O.; Sidorov, D.; Sidoti, A.; Siegert, F.; Sijacki, Dj.; Silva, J.; Silverstein, S. B.; Simak, V.; Simard, O.; Simic, Lj.; Simion, S.; Simioni, E.; Simmons, B.; Simon, D.; Simon, M.; Sinervo, P.; Sinev, N. B.; Sioli, M.; Siragusa, G.; Sivoklokov, S. Yu.; Sjölin, J.; Sjursen, T. B.; Skinner, M. B.; Skottowe, H. P.; Skubic, P.; Slater, M.; Slavicek, T.; Slawinska, M.; Sliwa, K.; Slovak, R.; Smakhtin, V.; Smart, B. H.; Smestad, L.; Smiesko, J.; Smirnov, S. Yu.; Smirnov, Y.; Smirnova, L. N.; Smirnova, O.; Smith, M. N. K.; Smith, R. W.; Smizanska, M.; Smolek, K.; Snesarev, A. A.; Snyder, S.; Sobie, R.; Socher, F.; Soffer, A.; Soh, D. A.; Sokhrannyi, G.; Solans Sanchez, C. A.; Solar, M.; Soldatov, E. Yu.; Soldevila, U.; Solodkov, A. A.; Soloshenko, A.; Solovyanov, O. V.; Solovyev, V.; Sommer, P.; Son, H.; Song, H. Y.; Sood, A.; Sopczak, A.; Sopko, V.; Sorin, V.; Sosa, D.; Sotiropoulou, C. L.; Soualah, R.; Soukharev, A. M.; South, D.; Sowden, B. C.; Spagnolo, S.; Spalla, M.; Spangenberg, M.; Spanò, F.; Sperlich, D.; Spettel, F.; Spighi, R.; Spigo, G.; Spiller, L. A.; Spousta, M.; St. Denis, R. D.; Stabile, A.; Stamen, R.; Stamm, S.; Stanecka, E.; Stanek, R. W.; Stanescu, C.; Stanescu-Bellu, M.; Stanitzki, M. M.; Stapnes, S.; Starchenko, E. A.; Stark, G. H.; Stark, J.; Staroba, P.; Starovoitov, P.; Stärz, S.; Staszewski, R.; Steinberg, P.; Stelzer, B.; Stelzer, H. J.; Stelzer-Chilton, O.; Stenzel, H.; Stewart, G. A.; Stillings, J. A.; Stockton, M. C.; Stoebe, M.; Stoicea, G.; Stolte, P.; Stonjek, S.; Stradling, A. R.; Straessner, A.; Stramaglia, M. E.; Strandberg, J.; Strandberg, S.; Strandlie, A.; Strauss, M.; Strizenec, P.; Ströhmer, R.; Strom, D. M.; Stroynowski, R.; Strubig, A.; Stucci, S. A.; Stugu, B.; Styles, N. A.; Su, D.; Su, J.; Subramaniam, R.; Suchek, S.; Sugaya, Y.; Suk, M.; Sulin, V. V.; Sultansoy, S.; Sumida, T.; Sun, S.; Sun, X.; Sundermann, J. E.; Suruliz, K.; Susinno, G.; Sutton, M. R.; Suzuki, S.; Svatos, M.; Swiatlowski, M.; Sykora, I.; Sykora, T.; Ta, D.; Taccini, C.; Tackmann, K.; Taenzer, J.; Taffard, A.; Tafirout, R.; Taiblum, N.; Takai, H.; Takashima, R.; Takeshita, T.; Takubo, Y.; Talby, M.; Talyshev, A. A.; Tan, K. G.; Tanaka, J.; Tanaka, R.; Tanaka, S.; Tannenwald, B. B.; Tapia Araya, S.; Tapprogge, S.; Tarem, S.; Tartarelli, G. F.; Tas, P.; Tasevsky, M.; Tashiro, T.; Tassi, E.; Tavares Delgado, A.; Tayalati, Y.; Taylor, A. C.; Taylor, G. N.; Taylor, P. T. E.; Taylor, W.; Teischinger, F. A.; Teixeira-Dias, P.; Temming, K. K.; Temple, D.; Ten Kate, H.; Teng, P. K.; Teoh, J. J.; Tepel, F.; Terada, S.; Terashi, K.; Terron, J.; Terzo, S.; Testa, M.; Teuscher, R. J.; Theveneaux-Pelzer, T.; Thomas, J. P.; Thomas-Wilsker, J.; Thompson, E. N.; Thompson, P. D.; Thompson, A. S.; Thomsen, L. A.; Thomson, E.; Thomson, M.; Tibbetts, M. J.; Ticse Torres, R. E.; Tikhomirov, V. O.; Tikhonov, Yu. A.; Timoshenko, S.; Tipton, P.; Tisserant, S.; Todome, K.; Todorov, T.; Todorova-Nova, S.; Tojo, J.; Tokár, S.; Tokushuku, K.; Tolley, E.; Tomlinson, L.; Tomoto, M.; Tompkins, L.; Toms, K.; Tong, B.; Torrence, E.; Torres, H.; Torró Pastor, E.; Toth, J.; Touchard, F.; Tovey, D. R.; Trefzger, T.; Tricoli, A.; Trigger, I. M.; Trincaz-Duvoid, S.; Tripiana, M. F.; Trischuk, W.; Trocmé, B.; Trofymov, A.; Troncon, C.; Trottier-McDonald, M.; Trovatelli, M.; Truong, L.; Trzebinski, M.; Trzupek, A.; Tseng, J. C.-L.; Tsiareshka, P. V.; Tsipolitis, G.; Tsirintanis, N.; Tsiskaridze, S.; Tsiskaridze, V.; Tskhadadze, E. G.; Tsui, K. M.; Tsukerman, I. I.; Tsulaia, V.; Tsuno, S.; Tsybychev, D.; Tudorache, A.; Tudorache, V.; Tuna, A. N.; Tupputi, S. A.; Turchikhin, S.; Turecek, D.; Turgeman, D.; Turra, R.; Turvey, A. J.; Tuts, P. M.; Tyndel, M.; Ucchielli, G.; Ueda, I.; Ueno, R.; Ughetto, M.; Ukegawa, F.; Unal, G.; Undrus, A.; Unel, G.; Ungaro, F. C.; Unno, Y.; Unverdorben, C.; Urban, J.; Urquijo, P.; Urrejola, P.; Usai, G.; Usanova, A.; Vacavant, L.; Vacek, V.; Vachon, B.; Valderanis, C.; Valdes Santurio, E.; Valencic, N.; Valentinetti, S.; Valero, A.; Valery, L.; Valkar, S.; Vallecorsa, S.; Valls Ferrer, J. A.; van den Wollenberg, W.; van der Deijl, P. C.; van der Geer, R.; van der Graaf, H.; van Eldik, N.; van Gemmeren, P.; van Nieuwkoop, J.; van Vulpen, I.; van Woerden, M. C.; Vanadia, M.; Vandelli, W.; Vanguri, R.; Vaniachine, A.; Vankov, P.; Vardanyan, G.; Vari, R.; Varnes, E. W.; Varol, T.; Varouchas, D.; Vartapetian, A.; Varvell, K. E.; Vasquez, J. G.; Vazeille, F.; Vazquez Schroeder, T.; Veatch, J.; Veloce, L. M.; Veloso, F.; Veneziano, S.; Ventura, A.; Venturi, M.; Venturi, N.; Venturini, A.; Vercesi, V.; Verducci, M.; Verkerke, W.; Vermeulen, J. C.; Vest, A.; Vetterli, M. C.; Viazlo, O.; Vichou, I.; Vickey, T.; Vickey Boeriu, O. E.; Viehhauser, G. H. A.; Viel, S.; Vigani, L.; Vigne, R.; Villa, M.; Villaplana Perez, M.; Vilucchi, E.; Vincter, M. G.; Vinogradov, V. B.; Vittori, C.; Vivarelli, I.; Vlachos, S.; Vlasak, M.; Vogel, M.; Vokac, P.; Volpi, G.; Volpi, M.; von der Schmitt, H.; von Toerne, E.; Vorobel, V.; Vorobev, K.; Vos, M.; Voss, R.; Vossebeld, J. H.; Vranjes, N.; Vranjes Milosavljevic, M.; Vrba, V.; Vreeswijk, M.; Vuillermet, R.; Vukotic, I.; Vykydal, Z.; Wagner, P.; Wagner, W.; Wahlberg, H.; Wahrmund, S.; Wakabayashi, J.; Walder, J.; Walker, R.; Walkowiak, W.; Wallangen, V.; Wang, C.; Wang, C.; Wang, F.; Wang, H.; Wang, H.; Wang, J.; Wang, J.; Wang, K.; Wang, R.; Wang, S. M.; Wang, T.; Wang, T.; Wang, W.; Wang, X.; Wanotayaroj, C.; Warburton, A.; Ward, C. P.; Wardrope, D. R.; Washbrook, A.; Watkins, P. M.; Watson, A. T.; Watson, M. F.; Watts, G.; Watts, S.; Waugh, B. M.; Webb, S.; Weber, M. S.; Weber, S. W.; Webster, J. S.; Weidberg, A. R.; Weinert, B.; Weingarten, J.; Weiser, C.; Weits, H.; Wells, P. S.; Wenaus, T.; Wengler, T.; Wenig, S.; Wermes, N.; Werner, M.; Werner, P.; Wessels, M.; Wetter, J.; Whalen, K.; Whallon, N. L.; Wharton, A. M.; White, A.; White, M. J.; White, R.; Whiteson, D.; Wickens, F. J.; Wiedenmann, W.; Wielers, M.; Wienemann, P.; Wiglesworth, C.; Wiik-Fuchs, L. A. M.; Wildauer, A.; Wilk, F.; Wilkens, H. G.; Williams, H. H.; Williams, S.; Willis, C.; Willocq, S.; Wilson, J. A.; Wingerter-Seez, I.; Winklmeier, F.; Winston, O. J.; Winter, B. T.; Wittgen, M.; Wittkowski, J.; Wollstadt, S. J.; Wolter, M. W.; Wolters, H.; Wosiek, B. K.; Wotschack, J.; Woudstra, M. J.; Wozniak, K. W.; Wu, M.; Wu, M.; Wu, S. L.; Wu, X.; Wu, Y.; Wyatt, T. R.; Wynne, B. M.; Xella, S.; Xu, D.; Xu, L.; Yabsley, B.; Yacoob, S.; Yakabe, R.; Yamaguchi, D.; Yamaguchi, Y.; Yamamoto, A.; Yamamoto, S.; Yamanaka, T.; Yamauchi, K.; Yamazaki, Y.; Yan, Z.; Yang, H.; Yang, H.; Yang, Y.; Yang, Z.; Yao, W.-M.; Yap, Y. C.; Yasu, Y.; Yatsenko, E.; Yau Wong, K. H.; Ye, J.; Ye, S.; Yeletskikh, I.; Yen, A. L.; Yildirim, E.; Yorita, K.; Yoshida, R.; Yoshihara, K.; Young, C.; Young, C. J. S.; Youssef, S.; Yu, D. R.; Yu, J.; Yu, J. M.; Yu, J.; Yuan, L.; Yuen, S. P. Y.; Yusuff, I.; Zabinski, B.; Zaidan, R.; Zaitsev, A. M.; Zakharchuk, N.; Zalieckas, J.; Zaman, A.; Zambito, S.; Zanello, L.; Zanzi, D.; Zeitnitz, C.; Zeman, M.; Zemla, A.; Zeng, J. C.; Zeng, Q.; Zengel, K.; Zenin, O.; Ženiš, T.; Zerwas, D.; Zhang, D.; Zhang, F.; Zhang, G.; Zhang, H.; Zhang, J.; Zhang, L.; Zhang, R.; Zhang, R.; Zhang, X.; Zhang, Z.; Zhao, X.; Zhao, Y.; Zhao, Z.; Zhemchugov, A.; Zhong, J.; Zhou, B.; Zhou, C.; Zhou, L.; Zhou, L.; Zhou, M.; Zhou, N.; Zhu, C. G.; Zhu, H.; Zhu, J.; Zhu, Y.; Zhuang, X.; Zhukov, K.; Zibell, A.; Zieminska, D.; Zimine, N. I.; Zimmermann, C.; Zimmermann, S.; Zinonos, Z.; Zinser, M.; Ziolkowski, M.; Živković, L.; Zobernig, G.; Zoccoli, A.; Zur Nedden, M.; Zurzolo, G.; Zwalinski, L.; Atlas Collaboration

    2016-06-01

    This paper presents a search for massive charged long-lived particles produced in p p collisions at √{s }=13 TeV at the LHC using the ATLAS experiment. The data set used corresponds to an integrated luminosity of 3.2 fb-1. Many extensions of the Standard Model predict the existence of massive charged long-lived particles, such as R -hadrons. These massive particles are expected to be produced with a velocity significantly below the speed of light, and therefore to have a specific ionization higher than any Standard Model particle of unit charge at high momenta. The Pixel subsystem of the ATLAS detector is used to measure the ionization energy loss of reconstructed charged particles and to search for such highly ionizing particles. The search presented here has much greater sensitivity than a similar search performed using the ATLAS detector in the √{s }=8 TeV data set, thanks to the increase in expected signal cross section due to the higher center-of-mass energy of collisions, to an upgraded detector with a new silicon layer close to the interaction point, and to analysis improvements. No significant deviation from Standard Model background expectations is observed, and lifetime-dependent upper limits on R -hadron production cross sections and masses are set. Gluino R -hadrons with lifetimes above 0.4 ns and decaying to q q ¯ plus a 100 GeV neutralino are excluded at the 95% confidence level, with lower mass limit ranging between 740 and 1590 GeV. In the case of stable R -hadrons the lower mass limit at the 95% confidence level is 1570 GeV.

  18. Characterization and separation of charged particles

    SciTech Connect

    Mukherjee, A.

    1987-01-01

    An investigation into the removal of electrically charged particles by using an electric field was carried out in both liquid and gaseous media. The systems studied in liquid media were clay particles suspended in synthetic fuels such as tar sand extracts and shale oils, whereas in gaseous media, the electrostatic removal of pyrites from coal was the objective. For proper design of separation equipment the charge of the particles was characterized as a function of the system variables. For the systems studied in the liquid media, the charge of the particles arises due to the adsorption of asphaltenes present in the synthetic fuel. The magnitude of the charge is strongly dependent on the amount of adsorbed asphaltenes. Small quantities of water have a drastic effect on the charge of the particles. As a result of the particle charge, a crossflow electrofilter can be used to completely remove these particles from the synthetic fuels. In gaseous media, the particles get charged by triboelectrification. The charge of pyrites and coal was measured in a continuous recirculating pneumatic conveyor using a ball probe as well as a Faraday cage. The charge of both coal and pyrites depends on the solid velocity, humidity, particle size, solids concentration, and surface oxidation. In most cases there is a sufficient charge difference between coal and pyrites to provide a driving force for electrostatic separation. Based on the charge difference a novel electrostatic separator was constructed. An improvement in the separator was made using a hydrodynamic model for two phase flow. Good agreement between the predictions of the model and experimental results were obtained.

  19. Charged particle distributions in Jupiter's magnetosphere

    NASA Astrophysics Data System (ADS)

    Divine, N.; Garrett, H. B.

    1983-09-01

    In situ data from the Pioneer and Voyager spacecraft, supplemented by earth-based observations and theoretical considerations, are used as the basis for the present quantitative, compact model of the 1 eV-several MeV charged particle distribution in the Jovian magnetosphere. The thermal plasma parameters of convection speed, number density, and characteristic energy, are specified as functions of position for electrons and for the ion species H(+), O(+), O(2+), S(+), S(2+), S(3+), and Na(+). Major features of the magnetic field, thermal plasma, and trapped particle distributions, are modeled and results for each plasma region are compared with observed spectra. Comparisons show that the model represents the data to within a factor of 2 + or - 1, except where time variations are significant. Practical applications of the model to spacecraft near Jupiter are given.

  20. Track-Structure Simulations for Charged Particles

    PubMed Central

    Dingfelder, Michael

    2013-01-01

    Monte-Carlo track-structure simulations provide a detailed and accurate picture of radiation transport of charged particles through condensed matter of biological interest. Liquid water serves as surrogate for soft tissue and is used in most Monte-Carlo track-structure codes. Basic theories of radiation transport and track-structure simulations are discussed and differences to condensed history codes highlighted. Interaction cross sections for electrons, protons, alpha particles, light and heavy ions are required input data for track-structure simulations. Different calculation methods, including the plane-wave Born approximation, the dielectric theory, and semi-empirical approaches are presented using liquid water as a target. Low-energy electron transport and light ion transport are discussed as areas of special interest. PMID:23032889

  1. Quantum and classical dissipation of charged particles

    SciTech Connect

    Ibarra-Sierra, V.G.; Anzaldo-Meneses, A.; Cardoso, J.L.; Hernández-Saldaña, H.; Kunold, A.; Roa-Neri, J.A.E.

    2013-08-15

    A Hamiltonian approach is presented to study the two dimensional motion of damped electric charges in time dependent electromagnetic fields. The classical and the corresponding quantum mechanical problems are solved for particular cases using canonical transformations applied to Hamiltonians for a particle with variable mass. Green’s function is constructed and, from it, the motion of a Gaussian wave packet is studied in detail. -- Highlights: •Hamiltonian of a damped charged particle in time dependent electromagnetic fields. •Exact Green’s function of a charged particle in time dependent electromagnetic fields. •Time evolution of a Gaussian wave packet of a damped charged particle. •Classical and quantum dynamics of a damped electric charge.

  2. Design of a compact, low-energy-charged-particle-spectrometer for stellar nucleosynthesis experiments at OMEGA and the NIF

    NASA Astrophysics Data System (ADS)

    Armstrong, E.; Frenje, J.; Gatu Johnson, M.; Li, C. K.; Rinderknecht, H.; Rosenberg, M.; Seguin, F. H.; Sio, H.; Zylstra, A.; Petrasso, R. D.

    2014-10-01

    A compact ``Orange'' Spectrometer is being designed for measurements of alpha and proton spectra in the range of ~ 1-5 MeV, produced in low-yield 3He3He experiments at the OMEGA laser and at the National Ignition Facility (NIF). Particle ray-tracing through magnetic fields, modeled by COMSOL, were conducted with the code Python. The goal is to identify an optimal setup for a spectrometer to measure alpha particles at relatively low energies and at low yield. Ability to study the alpha particles in addition to the protons is essential for understanding the nuclear physics governing the final-state interactions between pairs of particles in the three-body final state. This work was supported in part by the U.S. DOE and NLUF.

  3. Charged Dilation Black Holes as Particle Accelerators

    NASA Astrophysics Data System (ADS)

    Pradhan, Parthapratim

    2016-07-01

    We examine the possibility of arbitrarily high energy in the Center-of-mass frame of colliding neutral particles in the vicinity of the horizon of a charged dilation black hole(BH). We show that it is possible to achieve the infinite energy in the background of the dilation black hole without fine-tuning of the angular momentum parameter. It is found that the center-of-mass energy (E_{cm}) of collisions of particles near the infinite red-shift surface of the extreme dilation BHs are arbitrarily large while the non-extreme charged dilation BHs have the finite energy. We have also compared the E_{cm} at the horizon with the ISCO(Innermost Stable Circular Orbit) and MBCO (Marginally Bound Circular Orbit) for extremal RN BH and Schwarzschild BH. We find that for extreme RN BH the inequality becomes E_{cm}mid_{r_{+}}>E_{cm}mid_{r_{mb}}> E_{cm}mid_{r_{ISCO}} i.e. E_{cm}mid_{r_{+}=M}: E_{cm}mid_{r_{mb}= ({3+√{5}}/{2})M} : E_{cm}mid_{r_{ISCO}=4M} =∞ : 3.23 : 2.6 . While for Schwarzschild BH the ratio of CM energy is E_{cm}mid_{r_{+}=2M}: E_{cm}mid_{r_{mb}=4M} : E_{cm}mid_{r_{ISCO}=6M} = √{5} : √{2} : {√{13}}/{3}. Also for Gibbons-Maeda-Garfinkle-Horowitz-Strominger (GMGHS) BHs the ratio is being E_{cm}mid_{r_{+}=2M}: E_{cm}mid_{r_{mb}=2M} : E_{cm}mid_{r_{ISCO}=2M}=∞ : ∞ : ∞.

  4. Effect of charge asymmetry and charge screening on structure of superlattices formed by oppositely charged colloidal particles

    NASA Astrophysics Data System (ADS)

    Pavaskar, Ganeshprasad; Sharma, Siddharth; Punnathanam, Sudeep N.

    2012-04-01

    Colloidal suspensions made up of oppositely charged particles have been shown to self-assemble into substitutionally ordered superlattices. For a given colloidal suspension, the structure of the superlattice formed from self-assembly depends on its composition, charges on the particles, and charge screening. In this study we have computed the pressure-composition phase diagrams of colloidal suspensions made up of binary mixtures of equal sized and oppositely charged particles interacting via hard core Yukawa potential for varying values of charge screening and charge asymmetry. The systems are studied under conditions where the thermal energy is equal or greater in magnitude to the contact energy of the particles and the Debye screening length is smaller than the size of the particles. Our studies show that charge asymmetry has a significant effect on the ability of colloidal suspensions to form substitutionally ordered superlattices. Slight deviations of the charges from the stoichiometric ratio are found to drastically reduce the thermodynamic stability of substitutionally ordered superlattices. These studies also show that for equal-sized particles, there is an optimum amount of charge screening that favors the formation of substitutionally ordered superlattices.

  5. Quantum interface to charged particles in a vacuum

    NASA Astrophysics Data System (ADS)

    Okamoto, Hiroshi

    2015-11-01

    A superconducting qubit device suitable for interacting with a flying electron has recently been proposed [Okamoto and Nagatani, Appl. Phys. Lett. 104, 062604 (2014), 10.1063/1.4865244]. Either a clockwise or counterclockwise directed loop of half magnetic flux quantum encodes a qubit, which naturally interacts with any single charged particle with arbitrary kinetic energy. Here, the device's properties, sources of errors, and possible applications are studied in detail. In particular, applications include detection of a charged particle essentially without applying a classical force to it. Furthermore, quantum states can be transferred between an array of the proposed devices and the charged particle.

  6. Solar wind iron charge states as identifiers of coronal mass ejections and the characterization of a new low energy particle detector

    NASA Astrophysics Data System (ADS)

    Lepri, Susan Therese

    2004-08-01

    We examine Fe charge state distributions in the solar wind. The ionic composition of the solar wind directly reflects corona conditions within 4 5 solar radii. Charge state information can be used to determine coronal electron temperatures of source region plasma. Examination of the Fe charge states obtained by the Solar Wind Ion Composition Spectrometer (SWICS) on the Advanced Composition Explorer (ACE), shows a high correlation of the abundance ratio of Fe≥16+/FeTot > 10% with interplanetary coronal mass ejections (ICMEs) observed at 1 A.U. We designate these as “hot ICMEs” due to their associated high charge states. We use the abundance ratio to develop a threshold average Fe charge state, threshold , applicable to charge state data from other spacecraft unable to determine charge state abundances. Applying the threshold to in-ecliptic data from ACE and data from Ulysses along its polar orbit, we identify hot ICMEs as a function of latitude. We find a factor of four fewer hot ICMEs at high latitude than in the ecliptic. After studying features on the Sun near the time of the ICME eruption, we determine that solar flares are likely the source of the observed high Fe charge states. This result has important implications in understanding the relationship between solar flares and CMEs. For years, a controversy has existed over the causal relationship between flares and CMEs. Now, through the work of this thesis, compositional data provides convincing evidence of an association of flares and CMEs. In addition, we also characterize a new delta-doped charge-coupled device (CCD). The new delta-doped CCD has a dead layer that is ˜1/10 th the thickness of previous SSDs used in ACE/SWIGS. Using this detector, we are able to detect H+ and N+ ions with energies ranging from 1 10 keV in the laboratory. This is a remarkable increase in sensitivity for solid-state particle detectors which currently can only detect particles with energies >30 keV. Application of

  7. Charged particle dynamics in turbulent current sheets

    NASA Astrophysics Data System (ADS)

    Artemyev, A. V.; Vainchtein, D. L.; Neishtadt, A. I.; Zelenyi, L. M.

    2016-05-01

    We study dynamics of charged particle in current sheets with magnetic fluctuations. We use the adiabatic theory to describe the nonperturbed charged particle motion and show that magnetic field fluctuations destroy the adiabatic invariant. We demonstrate that the evolution of particle adiabatic invariant's distribution is described by a diffusion equation and derive analytical estimates of the rate of adiabatic invariant's diffusion. This rate is proportional to power density of magnetic field fluctuations. We compare analytical estimates with numerical simulations. We show that adiabatic invariant diffusion results in transient particles trapping in the current sheet. For magnetic field fluctuation amplitude a few times larger than a normal magnetic field component, more than 50% of transient particles become trapped. We discuss the possible consequences of destruction of adiabaticity of the charged particle motion on the state of the current sheets.

  8. Charged-particle (pseudo-)rapidity distributions in p+p/p+p and Pb+Pb/Au+Au collisions from UrQMD calculations at energies available at the CERN Super Proton Synchrotron to the Large Hadron Collider

    SciTech Connect

    Mitrovski, Michael; Petersen, Hannah; Schuster, Tim; Graef, Gunnar; Bleicher, Marcus

    2009-04-15

    We present results for final state charged-particle (pseudo-)rapidity distributions in p+p/p+p and Pb+Pb/Au+Au at ultra high energies (17.3 GeV{<=}{radical}(s{sub NN}){<=}14 TeV) from the Ultra-relativistic Quantum Molecular Dynamics (UrQMD-v2.3) model. In addition, excitation functions of produced charged-particle multiplicities (N{sub ch}) and pseudorapidity spectra are investigated up to CERN Large Hadron Collider energies. Good agreement is observed between UrQMD and measured pseudorapidity distributions of charged particles up to the highest Tevatron and SppS energies.

  9. Tunable resonant sensing means to sense a particular frequency in a high energy charged particle beam and generate a frequency-domain signal in response

    DOEpatents

    Nakamura, Michiyuki; Nolan, Marvin L.

    1988-01-01

    A frequency domain sensing system is disclosed for sensing the position of a high energy beam of charged particles traveling within a housing which comprises a plurality of sensors positioned in the wall of the housing radially around the axis of the beam. Each of the sensors further comprises a first electrode of predetermined shape received in a bore in the housing to define a fixed capacitance and an inductance structure attached to the electrode to provide an inductance for the sensing means which will provide an LC circuit which will resonate at a predetermined frequency known to exist in the beam of charged particles. The sensors are further provided with tuning apparatus associated with the inductance structure to vary the amount of the inductance to thereby tune the sensors to the predetermined frequency prior to transmission of the signal to signal detection circuitry.

  10. 950809 Charged particle transport updated multi-group diffusion

    SciTech Connect

    Corman, E.G.; Perkins, S.T.; Dairiki, N.T.

    1995-09-01

    In 1974, a charged particle transport scheme was introduced which utilized a multi-group diffusion method for the spatial transport and slowing down of energetic ions in a hot plasma. In this treatment a diffusion coefficient was used which was flux-limited to provide, hopefully, some degree of accuracy when the slowing down of an energetic charged particle is dominated by Coulomb collisions with thermal ions and electrons in a plasma medium. An advantage of this method was a very fast, memory-contained program for calculating the behavior of energetic charged particles which resulted in smoothly varying particle number densities and energy depositions. The main limitation of the original multi-group charged particle diffusion scheme is its constraint to a basic ten group structure; the same ten group structure for each of the five energetic ions tracked. This is regarded as a severe limitation, inasmuch as more groups would be desired to simulate more accurately the corresponding Monte Carlo results of energies deposited over spatial zones from a charged particle source. More generally, it seems preferable to have a different group structure for each particle type since they are created at inherently different energies. In this paper, the basic theory and multi-group description will be given. This is followed by the specific techniques that were used to solve the resultant equations. Finally, the modifications that were made to the cross section data as well as the methods used for energy and momentum deposition are described.

  11. Charged particles constrained to a curved surface

    NASA Astrophysics Data System (ADS)

    Müller, Thomas; Frauendiener, Jörg

    2013-01-01

    We study the motion of charged particles constrained to arbitrary two-dimensional curved surfaces but interacting in three-dimensional space via the Coulomb potential. To speed up the interaction calculations, we use the parallel compute capability of the Compute Unified Device Architecture of today's graphics boards. The particles and the curved surfaces are shown using the Open Graphics Library. This paper is intended to give graduate students, who have basic experiences with electrostatics and the Lagrangian formalism, a deeper understanding of charged particle interactions and a short introduction of how to handle a many particle system using parallel computing on a single home computer.

  12. Robust statistical reconstruction for charged particle tomography

    DOEpatents

    Schultz, Larry Joe; Klimenko, Alexei Vasilievich; Fraser, Andrew Mcleod; Morris, Christopher; Orum, John Christopher; Borozdin, Konstantin N; Sossong, Michael James; Hengartner, Nicolas W

    2013-10-08

    Systems and methods for charged particle detection including statistical reconstruction of object volume scattering density profiles from charged particle tomographic data to determine the probability distribution of charged particle scattering using a statistical multiple scattering model and determine a substantially maximum likelihood estimate of object volume scattering density using expectation maximization (ML/EM) algorithm to reconstruct the object volume scattering density. The presence of and/or type of object occupying the volume of interest can be identified from the reconstructed volume scattering density profile. The charged particle tomographic data can be cosmic ray muon tomographic data from a muon tracker for scanning packages, containers, vehicles or cargo. The method can be implemented using a computer program which is executable on a computer.

  13. Quenching gas for detectors of charged particles

    DOEpatents

    Atac, M.

    1974-01-22

    Operation of detectors of charged particles such as wire counters and Geiger-Muller tubes is improved by filling the counters with a quenching-gas mixture of argon, isobutane and methylchloroform. (Official Gazette)

  14. Forward energy flow, central charged-particle multiplicities, and pseudorapidity gaps in W and Z boson events from pp collisions at $\\sqrt{s}= 7$ TeV

    SciTech Connect

    Chatrchyan, Serguei; et al.

    2012-01-01

    A study of forward energy flow and central charged-particle multiplicity in events with W and Z bosons decaying into leptons is presented. The analysis uses a sample of 7 TeV pp collisions, corresponding to an integrated luminosity of 36 inverse picobarns, recorded by the CMS experiment at the LHC. The observed forward energy depositions, their correlations, and the central charged-particle multiplicities are not well described by the available non-diffractive soft-hadron production models. A study of about 300 events with no significant energy deposited in one of the forward calorimeters, corresponding to a pseudorapidity gap of at least 1.9 units, is also presented. An indication for a diffractive component in these events comes from the observation that the majority of the charged leptons from the (W/Z) decays are found in the hemisphere opposite to the gap. When fitting the signed lepton pseudorapidity distribution of these events with predicted distributions from an admixture of diffractive (POMPYT) and non-diffractive (PYTHIA) Monte Carlo simulations, the diffractive component is determined to be (50.0 +/- 9.3 (stat.) +/- 5.2 (syst.))%.

  15. On charged particle tracks in cellulose nitrate and Lexan

    NASA Technical Reports Server (NTRS)

    Benton, E. V.; Henke, R. P.

    1972-01-01

    Investigations were performed aimed at developing plastic nuclear track detectors into quantitative tools for recording and measuring multicharged, heavy particles. Accurate track etch rate measurements as a function of LET were performed for cellulose nitrate and Lexan plastic detectors. This was done using a variety of incident charged particle types and energies. The effect of aging of latent tracks in Lexan in different gaseous atmospheres was investigated. Range distributions of high energy N-14 particle bevatron beams in nuclear emulsion were measured. Investigation of charge resolution and Bragg peak measurements were carried out using plastic nuclear track detectors.

  16. Design of a compact, low energy charged particle spectrometer for stellar nucleosynthesis experiments at OMEGA and the NIF

    NASA Astrophysics Data System (ADS)

    Armstrong, E.; Frenje, J.; Gatu Johnson, M.; Li, C. K.; Orozco, D.; Rinderknecht, H.; Rosenberg, M.; Séguin, F. H.; Sio, H.; Zylstra, A.; Petrasso, R. D.

    2015-11-01

    Simulations have been used to model an ``Orange Spectrometer'' for measuring alpha and proton energy spectra in the range ~1-5 MeV for experiments at the OMEGA laser facility and the National Ignition Facility (NIF). An important application will be the study of stellar nucleosynthesis reactions, in particular 3He +3He --> α + p +p, which is a step in the solar proton-proton chain. Experiments to study this reaction have been undertaken at OMEGA before, but no diagnostics have been able to measure the low-energy, low-yield alpha particles generated in the reaction. Feasibility studies were performed with particle trajectory calculations utilizing magnetic field models from COMSOL, and several designs have been identified for testing and development. Ability to study the alpha particles in addition to the protons is essential for understanding the nuclear physics governing the final-state interactions between pairs of particles in the three-body final state. This work was supported in part by NLUF, DOE, and LLE.

  17. Dynamics of Charged Dust Particle near Conducting Wall in TOKAMAK

    NASA Astrophysics Data System (ADS)

    Angus, Justin; Krasheninnikov, Sergei

    2010-11-01

    A substantial amount of dust has been observed to be present near the first walls of fusion devices. The impact of dust on plasma parameters in current and future fusion devices is not clear and may cause a significant safety threat. It is therefore important to understand the dynamics of dust particles after formation. A surface charge is induced on the wall of a conducting material in the presence of a charged particle. The charged particle is then attracted to the wall by this induced charge causing the charge in the wall to redistribute and thus increasing the force of attraction further. In this work we study the dynamics of this attraction and the dissipation of electromagnetic energy via joule heating within the conducting wall.

  18. The charged particle radiation environment for AXAF

    NASA Technical Reports Server (NTRS)

    Joy, Marshall

    1990-01-01

    The Advanced X Ray Astrophysics Facility (AXAF) will be subjected to several sources of charged particle radiation during its 15-year orbital lifetime: geomagnetically-trapped electrons and protons, galactic cosmic ray particles, and solar flare events. These radiation levels are presented for the AXAF orbit for use in the design of the observatory's science instruments.

  19. Electrostatic wire for stabilizing a charged particle beam

    DOEpatents

    Prono, Daniel S.; Caporaso, George J.; Briggs, Richard J.

    1985-01-01

    In combination with a charged particle beam generator and accelerator, apparatus and method are provided for stabilizing a beam of electrically charged particles. A guiding means, disposed within the particle beam, has an electric charge induced upon it by the charged particle beam. Because the sign of the electric charge on the guiding means and the sign of the particle beam are opposite, the particles are attracted toward and cluster around the guiding means to thereby stabilize the particle beam as it travels.

  20. Discrete Element Modeling of Triboelectrically Charged Particles

    NASA Technical Reports Server (NTRS)

    Hogue, Michael D.; Calle, Carlos I.; Weitzman, Peter S.; Curry, David R.

    2008-01-01

    Tribocharging of particles is common in many processes including fine powder handling and mixing, printer toner transport and dust extraction. In a lunar environment with its high vacuum and lack of water, electrostatic forces are an important factor to consider when designing and operating equipment. Dust mitigation and management is critical to safe and predictable performance of people and equipment. The extreme nature of lunar conditions makes it difficult and costly to carry out experiments on earth which are necessary to better understand how particles gather and transfer charge between each other and with equipment surfaces. DEM (Discrete Element Modeling) provides an excellent virtual laboratory for studying tribocharging of particles as well as for design of devices for dust mitigation and for other purposes related to handling and processing of lunar regolith. Theoretical and experimental work has been performed pursuant to incorporating screened Coulombic electrostatic forces into EDEM, a commercial DEM software package. The DEM software is used to model the trajectories of large numbers of particles for industrial particulate handling and processing applications and can be coupled with other solvers and numerical models to calculate particle interaction with surrounding media and force fields. While simple Coulombic force between two particles is well understood, its operation in an ensemble of particles is more complex. When the tribocharging of particles and surfaces due to frictional contact is also considered, it is necessary to consider longer range of interaction of particles in response to electrostatic charging. The standard DEM algorithm accounts for particle mechanical properties and inertia as a function of particle shape and mass. If fluid drag is neglected, then particle dynamics are governed by contact between particles, between particles and equipment surfaces and gravity forces. Consideration of particle charge and any tribocharging and

  1. The joint NASA/Goddard-University of Maryland research program in charged particle and high energy photon detector technology

    NASA Technical Reports Server (NTRS)

    1987-01-01

    The first measurements of Fe charge states in two coronal hole-association high speed streams, using the sensor on ISEE-3, are presented. Eight event intervals from the January to June 1983 timeframe were chosen for the study of magnetotail dynamics and its relationship to substorm activity and the possible formation of plasmoids. Techniques are being explored for measurement of secondary electrons which are characteristically emitted when ions hit a target material. Efforts are continuing to understand kilometer wavelength shock associated radio events. An all-sky survey of fast X-ray transients of duration of 5 to 10,000 s was completed. Research using high resolution gamma-ray spectroscopy of celestial sources in the 20 keV to 20 MeV range to search for and study narrow lines in low-energy gamma-ray spectrum continues. Research in high energy radiation from pulsars is being conducted.

  2. Visualization of charged particle traversals in cells

    SciTech Connect

    Metting, N.F.; Braby, L.A.

    1997-12-31

    This research addresses the early events that occur in the cell, and particularly in the cell nucleus, after passage of a charged particle. The authors present an assay system which locates the path of a charged particle through the cell nucleus, and speculate that this will be a valuable tool to define a start point for cell signaling of DNA repair processes, as well as signaling of cell-cycle checkpoint proteins. This study of the biological effects of low doses of high LET particles stems from the need to understand molecular mechanisms of long term health effects originating from the heavy particle component of galactic cosmic rays, a major concern in extended space missions. In the deep-space environment each target cell would be traversed only once a month, on average, by a heavy charged particle (1); therefore it was important to use very low particle fluences for subsequent analysis and understanding of resulting measurements. The Single-Cell/Single-particle Irradiator at PNNL was used to deliver particles from an electrostatic accelerator, and thus eliminate most of the experimental variability in the exposure of cells to high LET radiation. The number of tracks through each cell can be specified, rather than the random number obtained with conventional irradiation. Irradiation can be limited to a specified portion of the cell, and the variation in stopping power of the particles as they enter the cell can be minimized.

  3. Why do particle clouds generate electric charges?

    NASA Astrophysics Data System (ADS)

    Pähtz, T.; Herrmann, H. J.; Shinbrot, T.

    2010-05-01

    Grains in desert sandstorms spontaneously generate strong electrical charges; likewise volcanic dust plumes produce spectacular lightning displays. Charged particle clouds also cause devastating explosions in food, drug and coal processing industries. Despite the wide-ranging importance of granular charging in both nature and industry, even the simplest aspects of its causes remain elusive, because it is difficult to understand how inert grains in contact with little more than other inert grains can generate the large charges observed. Here, we present a simple yet predictive explanation for the charging of granular materials in collisional flows. We argue from very basic considerations that charge transfer can be expected in collisions of identical dielectric grains in the presence of an electric field, and we confirm the model's predictions using discrete-element simulations and a tabletop granular experiment.

  4. On charging of snow particles in blizzard

    NASA Technical Reports Server (NTRS)

    Shio, Hisashi

    1991-01-01

    The causes of the charge polarity on the blizzard, which consisted of fractured snow crystals and ice particles, were investigated. As a result, the charging phenomena showed that the characteristics of the blizzard are as follows: (1) In the case of the blizzard with snowfall, the fractured snow particles drifting near the surface of snow field (lower area: height 0.3 m) had positive charge, while those drifting at higher area (height 2 m) from the surface of snow field had negative charge. However, during the series of blizzards two kinds of particles positively and negatively charged were collected in equal amounts in a Faraday Cage. It may be considered that snow crystals with electrically neutral properties were separated into two kinds of snow flakes (charged positively and negatively) by destruction of the snow crystals. (2) In the case of the blizzard which consisted of irregularly formed ice drops (generated by peeling off the hardened snow field), the charge polarity of these ice drops salting over the snow field was particularly controlled by the crystallographic characteristics of the surface of the snow field hardened by the powerful wind pressure.

  5. The Response of the Ionospheric Cusp to the Solar Wind Through Two Perspectives: Low Energy Charged Particle In-Situ Measurements and Low-Energy Neutral Atom Imaging

    NASA Technical Reports Server (NTRS)

    Coffey, V. N.; Moore, T. E.; Chandler, M. O.; Giles, B. L.; Craven, P. D.; Rose, M. Franklin (Technical Monitor)

    2000-01-01

    The Imager for Magnetopause-to-Aurora Global Exploration (IMAGE) mission provides a new perspective on the study of the response of the magnetosphere/ionosphere system to changing solar wind conditions, particularly the variability of ion outflow. Learning to interpret this new type of data becomes an essential step in the process of melding these results with the wealth of in-situ charged particle observations obtained over the past 25 years. In order to understand how the in-situ data correspond to and contrast with IMAGE results we will perform a conjunctive study of event data from two instruments to shed light on the coupling of the solar wind and ionosphere from these different perspectives. We will use the Low Energy Neutral Atom instrument (LENA) which images energetic neutral atom emissions from upward flowing ionospheric ions and the Thermal Ion Dynamics Instrument (TIDE) on the Polar satellite which measures in-situ ion outflow from 0.3-300 eV. Our primary goal will be to understand how comparing the imaging and in-situ perspectives can aid in the analysis of both data sets.

  6. The Joint NASA/Goddard-University of Maryland Research Program in Charged Particle and High Energy Photon Detector Technology

    NASA Technical Reports Server (NTRS)

    Ipavich, F. M.

    1990-01-01

    The Univ. of Maryland portion investigated the following areas. The Space Physics Group performed studies of data from the AMPTE/CCE spacecraft CHEM experiment and found that the ratio of solar wind to photospheric abundances decreased rather smoothly with the first ionization potential (FIP) of the ion with the low FIP ion being about a factor of two overabundant. Carbon and hydrogen fit this trend particularly well. Several occurrences were analyzed of field aligned beams observed when CCE was upstream of the Earth's bow shock. Also using CHEM data, ring current intensity and composition changes during the main and recovery phases of the great geomagnetic storm that occurred in February 1986 was examined in detail. Still using CHEM data, ring current characteristics were examined in a survey of 20 magnetic storms ranging in size from -50 nT to -312 nT. A study was done of energetic ion anisotropy characteristics in the Earth's magnetosheath region using data from the UMD/MPE experiment on ISEE-1. The properties were analyzed of approx. 30 to 130 keV/e protons and alpha particles upstream of six quasi-parallel interplanetary shocks that passed by the ISEE-3 spacecraft during 1978 to 1979. Work from NASA-Goddard include studies from the High Energy Cosmic Ray Group, Low Energy Cosmic Ray Group, Low Energy Gamma Ray Group, High Energy Astrophysics Theory Group, and the X ray Astronomy Group.

  7. Search for metastable heavy charged particles with large ionisation energy loss in pp collisions at $${\\sqrt{s} = 8}$$ s = 8 TeV using the ATLAS experiment

    DOE PAGESBeta

    Aad, G.

    2015-09-03

    Many extensions of the Standard Model predict the existence of charged heavy long-lived particles, such as R-hadrons or charginos. These particles, if produced at the Large Hadron Collider, should be moving non-relativistically and are therefore identifiable through the measurement of an anomalously large specific energy loss in the ATLAS pixel detector. Measuring heavy long-lived particles through their track parameters in the vicinity of the interaction vertex provides sensitivity to metastable particles with lifetimes from 0.6 ns to 30 ns. A search for such particles with the ATLAS detector at the Large Hadron Collider is presented, based on a data samplemore » corresponding to an integrated luminosity of \\(18.4\\) fb\\(^{-1}\\) of pp collisions at \\(\\sqrt{s} = 8\\) TeV. No significant deviation from the Standard Model background expectation is observed, and lifetime-dependent upper limits on R-hadrons and chargino production are set. Gluino R-hadrons with 10 ns lifetime and masses up to 1185 GeV are excluded at 95 \\(\\%\\) confidence level, and so are charginos with 15 ns lifetime and masses up to 482 GeV.« less

  8. Search for metastable heavy charged particles with large ionisation energy loss in pp collisions at ${\\sqrt{s} = 8}$ s = 8 TeV using the ATLAS experiment

    SciTech Connect

    Aad, G.

    2015-09-03

    Many extensions of the Standard Model predict the existence of charged heavy long-lived particles, such as R-hadrons or charginos. These particles, if produced at the Large Hadron Collider, should be moving non-relativistically and are therefore identifiable through the measurement of an anomalously large specific energy loss in the ATLAS pixel detector. Measuring heavy long-lived particles through their track parameters in the vicinity of the interaction vertex provides sensitivity to metastable particles with lifetimes from 0.6 ns to 30 ns. A search for such particles with the ATLAS detector at the Large Hadron Collider is presented, based on a data sample corresponding to an integrated luminosity of \\(18.4\\) fb\\(^{-1}\\) of pp collisions at \\(\\sqrt{s} = 8\\) TeV. No significant deviation from the Standard Model background expectation is observed, and lifetime-dependent upper limits on R-hadrons and chargino production are set. Gluino R-hadrons with 10 ns lifetime and masses up to 1185 GeV are excluded at 95 \\(\\%\\) confidence level, and so are charginos with 15 ns lifetime and masses up to 482 GeV.

  9. Low-energy charge-density excitations in MgB2: Striking interplay between single-particle and collective behavior for large momenta.

    PubMed

    Cai, Y Q; Chow, P C; Restrepo, O D; Takano, Y; Togano, K; Kito, H; Ishii, H; Chen, C C; Liang, K S; Chen, C T; Tsuda, S; Shin, S; Kao, C C; Ku, W; Eguiluz, A G

    2006-10-27

    A sharp feature in the charge-density excitation spectra of single-crystal MgB2, displaying a remarkable cosinelike, periodic energy dispersion with momentum transfer (q) along the c* axis, has been observed for the first time by high-resolution nonresonant inelastic x-ray scattering (NIXS). Time-dependent density-functional theory calculations show that the physics underlying the NIXS data is strong coupling between single-particle and collective degrees of freedom, mediated by large crystal local-field effects. As a result, the small-q collective mode residing in the single-particle excitation gap of the B pi bands reappears periodically in higher Brillouin zones. The NIXS data thus embody a novel signature of the layered electronic structure of MgB2.

  10. Charged-particle multiplicity and pseudorapidity distributionsmeasured with the PHOBOS detector in Au+Au, Cu+Cu, d+Au, and p+p collisions at ultra-relativistic energies.

    SciTech Connect

    Alver, B.; Back, B. B.; Baker, M. D.; Ballintijn, M.; Barton, D. S.; Wuosmaa, A.

    2011-01-01

    Pseudorapidity distributions of charged particles emitted in Au+Au, Cu+Cu, d+Au, and p+p collisions over a wide energy range have been measured using the PHOBOS detector at the BNL Relativistic Heavy-Ion Collider (RHIC). The centrality dependence of both the charged particle distributions and the multiplicity at midrapidity were measured. Pseudorapidity distributions of charged particles emitted with |{eta}| < 5.4, which account for between 95% and 99% of the total charged-particle emission associated with collision participants, are presented for different collision centralities. Both the midrapidity density dN{sub ch}/d{eta} and the total charged-particle multiplicity N{sub ch} are found to factorize into a product of independent functions of collision energy, {radical}s{sub NN}, and centrality given in terms of the number of nucleons participating in the collision, N{sub part}. The total charged particle multiplicity, observed in these experiments and those at lower energies, assumes a linear dependence of (lns{sub NN}){sup 2} over the full range of collision energy of {radical}s{sub NN} = 2.7-200 GeV.

  11. Charged-particle multiplicity and pseudorapidity distributions measured with the PHOBOS detector in Au+Au, Cu+Cu, d+Au, and p+p collisions at ultrarelativistic energies

    SciTech Connect

    Alver, B.; Ballintijn, M.; Busza, W.; Decowski, M. P.; Gulbrandsen, K.; Henderson, C.; Kane, J. L.; Katzy, J.; Kulinich, P.; Li, W.; Loizides, C.; Pernegger, H.; Reed, C.; Roland, C.; Roland, G.; Rosenberg, L.; Sarin, P.; Steadman, S. G.; Stephans, G. S. F.; Vale, C.

    2011-02-15

    Pseudorapidity distributions of charged particles emitted in Au+Au, Cu+Cu, d+Au, and p+p collisions over a wide energy range have been measured using the PHOBOS detector at the BNL Relativistic Heavy-Ion Collider (RHIC). The centrality dependence of both the charged particle distributions and the multiplicity at midrapidity were measured. Pseudorapidity distributions of charged particles emitted with |{eta}|<5.4, which account for between 95% and 99% of the total charged-particle emission associated with collision participants, are presented for different collision centralities. Both the midrapidity density dN{sub ch}/d{eta} and the total charged-particle multiplicity N{sub ch} are found to factorize into a product of independent functions of collision energy, {radical}(s{sub N{sub N}}), and centrality given in terms of the number of nucleons participating in the collision, N{sub part}. The total charged particle multiplicity, observed in these experiments and those at lower energies, assumes a linear dependence of (lns{sub N{sub N}}){sup 2} over the full range of collision energy of {radical}(s{sub N{sub N}})=2.7-200 GeV.

  12. Charged-particle calculations using Boltzmann transport methods

    SciTech Connect

    Hoffman, T.J.; Dodds, H.L. Jr.; Robinson, M.T.; Holmes, D.K.

    1981-01-01

    Several aspects of radiation damage effects in fusion reactor neutron and ion irradiation environments are amenable to treatment by transport theory methods. In this paper, multigroup transport techniques are developed for the calculation of charged particle range distributions, reflection coefficients, and sputtering yields. The Boltzmann transport approach can be implemented, with minor changes, in standard neutral particle computer codes. With the multigroup discrete ordinates code, ANISN, determination of ion and target atom distributions as functions of position, energy, and direction can be obtained without the stochastic error associated with atomistic computer codes such as MARLOWE and TRIM. With the multigroup Monte Carlo code, MORSE, charged particle effects can be obtained for problems associated with very complex geometries. Results are presented for several charged particle problems. Good agreement is obtained between quantities calculated with the multigroup approach and those obtained experimentally or by atomistic computer codes.

  13. Charged Particle lunar Environment Experiment (CPLEE)

    NASA Technical Reports Server (NTRS)

    Reasoner, D. L.

    1974-01-01

    Research development in the Charged Particle Lunar Environment Experiment (CPLEE) is reported. The CPLEE is ion-electron spectrometer placed on the lunar surface for the purpose of measuring charged particle fluxes impacting the moon from a variety of regions and to study the interactions between space plasmas and the lunar surface. The principal accomplishments reported include: (1) furnishing design specifications for construction of the CPLEE instruments; (2) development of an advanced computer-controlled facility for automated instrument calibration; (3) active participation in the deployment and past-deployment operational phases with regard to data verification and operational mode selection; and (4) publication of research papers, including a study of lunar photoelectrons, a study of plasmas resulting from man-made lunar impart events, a study of magnetotail and magnetosheath particle populations, and a study of solar-flare interplanetary particles.

  14. Neutron Time-of-Flight Measurements of Charged-Particle Energy Loss in Inertial Confinement Fusion Plasmas

    NASA Astrophysics Data System (ADS)

    Sayre, Daniel; Cerjan, Charlie; Berzak Hopkins, Laura; Caggiano, Joseph; Divol, Laurent; Eckart, Mark; Graziani, Frank; Grim, Gary; Hartouni, Ed; Hatarik, Robert; Le Pape, Sebastien; MacKinnon, Andrew; Schneider, Dieter; Sepke, Scott

    2015-11-01

    Neutron time-of-flight measurements of inflight T (d , n) α reactions created during an implosion of a deuterium gas target have been performed at the National Ignition Facility, with order of magnitude improvements in statistics and resolution over past experiments. In the implosion, energetic tritons emitted by thermonuclear fusion within the deuterium plasma produced over 1011 inflight T (d , n) α reactions. The yield and particle spectrum of inflight reactions are sensitive to the triton's energy loss in the plasma, which, in this implosion, consisted of multi-keV temperatures and number densities above 1024 cm-3. Radiation-hydrodynamic simulations of the implosion were adjusted to match the yield and broadening of the D (d , n) 3 He neutron peak. These same simulations give reasonable agreement with the measured T (d , n) α yield and neutron spectrum, and this provides a strong consistency check of the simulated plasma conditions and energy loss model. This research was performed under the auspices of the U. S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344.

  15. Ionic colloidal crystals of oppositely charged particles.

    PubMed

    Leunissen, Mirjam E; Christova, Christina G; Hynninen, Antti-Pekka; Royall, C Patrick; Campbell, Andrew I; Imhof, Arnout; Dijkstra, Marjolein; van Roij, René; van Blaaderen, Alfons

    2005-09-01

    Colloidal suspensions are widely used to study processes such as melting, freezing and glass transitions. This is because they display the same phase behaviour as atoms or molecules, with the nano- to micrometre size of the colloidal particles making it possible to observe them directly in real space. Another attractive feature is that different types of colloidal interactions, such as long-range repulsive, short-range attractive, hard-sphere-like and dipolar, can be realized and give rise to equilibrium phases. However, spherically symmetric, long-range attractions (that is, ionic interactions) have so far always resulted in irreversible colloidal aggregation. Here we show that the electrostatic interaction between oppositely charged particles can be tuned such that large ionic colloidal crystals form readily, with our theory and simulations confirming the stability of these structures. We find that in contrast to atomic systems, the stoichiometry of our colloidal crystals is not dictated by charge neutrality; this allows us to obtain a remarkable diversity of new binary structures. An external electric field melts the crystals, confirming that the constituent particles are indeed oppositely charged. Colloidal model systems can thus be used to study the phase behaviour of ionic species. We also expect that our approach to controlling opposite-charge interactions will facilitate the production of binary crystals of micrometre-sized particles, which could find use as advanced materials for photonic applications.

  16. Studying Charged Particle Optics: An Undergraduate Course

    ERIC Educational Resources Information Center

    Ovalle, V.; Otomar, D. R.; Pereira, J. M.; Ferreira, N.; Pinho, R. R.; Santos A. C. F.

    2008-01-01

    This paper describes some computer-based activities to bring the study of charged particle optics to undergraduate students, to be performed as a part of a one-semester accelerator-based experimental course. The computational simulations were carried out using the commercially available SIMION program. The performance parameters, such as the focal…

  17. Highly efficient charged particle veto detector CUP

    NASA Astrophysics Data System (ADS)

    Palacz, M.; Nyberg, J.; Bednarczyk, P.; Dworski, J.; Górska, M.; Iwanicki, J.; Kapusta, M.; Kownacki, J.; Kulczycka, E.; Lagergren, K.; Moszyński, M.; Pieńkowski, L.; Stolarz, A.; Wolski, D.; Ziębliński, M.

    2005-09-01

    A novel, highly efficient, plastic scintillator detector has been constructed. The primary application of the detector is to act as a veto device in heavy-ion-induced fusion-evaporation reactions, in which the structure of proton-rich nuclides is investigated by γ-ray spectroscopy methods. The detector rejects events in which light charged particles, like protons and α particles, are emitted in the evaporation process, facilitating selection of reaction channels associated with emission of only neutrons. The detector was used in a EUROBALL experiment, with achieved efficiencies of 80% and 63% for protons and α particles, respectively. The design of the detector, its performance and limitations are discussed.

  18. UNIVERSAL BEHAVIOR OF CHARGED PARTICLE PRODUCTION IN HEAVY ION COLLISIONS.

    SciTech Connect

    STEINBERG,P.A.FOR THE PHOBOS COLLABORATION

    2002-07-24

    The PHOBOS experiment at RHIC has measured the multiplicity of primary charged particles as a function of centrality and pseudorapidity in Au+Au collisions at {radical}(s{sub NN}) = 19.6, 130 and 200 GeV. Two observations indicate universal behavior of charged particle production in heavy ion collisions. The first is that forward particle production, over a range of energies, follows a universal limiting curve with a non-trivial centrality dependence. The second arises from comparisons with pp/{bar p}p and e{sup +}e{sup -} data. / in nuclear collisions at high energy scales with {radical}s in a similar way as N{sub ch} in e{sup +}e{sup -} collisions and has a very weak centrality dependence. These features may be related to a reduction in the leading particle effect due to the multiple collisions suffered per participant in heavy ion collisions.

  19. First Results from the ISS-RAD Charged Particle Detector

    NASA Technical Reports Server (NTRS)

    Semones, Edward; Zeitland, Cary

    2016-01-01

    The Charged Particle Detector (CPD) subsystem of the ISS-RAD detector has been making measurements of high-energy charged and neutral particles since the unit was deployed on Feb. 1, 2016. The CPD is nearly identical to the MSL-RAD instrument, but onboard data processing has been significantly modified to meet ISS requirements. We will present dose rates and LET spectra obtained over the first six months of operations, as well as preliminary results obtained from the limited sample of pulse-height analyzed raw data that has been telemetered to Earth.

  20. DNA fragmentation by charged particle tracks

    NASA Astrophysics Data System (ADS)

    Stenerlöw, B.; Höglund, E.; Carlsson, J.

    High-LET (linear energy transfer) charged particles induce DNA double-strand breaks (DSB) in a non-random fashion in mammalian cells. The clustering of DSB, probably determined by track structure as well as chromatin conformation, results in an excess of small- and intermediate-sized DNA fragments. DNA fragmentation in normal human fibroblasts (GM5758) was analyzed by pulsed-field gel electrophoresis after irradiation with photons ( 60Co) or 125 keV/μm nitrogen ions. Compared to conventional DSB analysis, i.e. assays only measuring the fraction of DNA smaller than a single threshold, the relative biological effectiveness (RBE) for DSB induction increased with 100%. Further, the size distribution of DNA fragments showed a significant dependence on radiation quality, with an excess of fragments up to 1 Mbp. Irradiation of naked genomic DNA without histone proteins increased the DSB yields 25 and 13 times for photons and nitrogen ions, respectively. The results suggest possible roles of both track structure and chromatin organization in the distribution of DNA double-strand breaks along the chromosome.

  1. Particle transport through hydrogels is charge asymmetric.

    PubMed

    Zhang, Xiaolu; Hansing, Johann; Netz, Roland R; DeRouchey, Jason E

    2015-02-01

    Transport processes within biological polymer networks, including mucus and the extracellular matrix, play an important role in the human body, where they serve as a filter for the exchange of molecules and nanoparticles. Such polymer networks are complex and heterogeneous hydrogel environments that regulate diffusive processes through finely tuned particle-network interactions. In this work, we present experimental and theoretical studies to examine the role of electrostatics on the basic mechanisms governing the diffusion of charged probe molecules inside model polymer networks. Translational diffusion coefficients are determined by fluorescence correlation spectroscopy measurements for probe molecules in uncharged as well as cationic and anionic polymer solutions. We show that particle transport in the charged hydrogels is highly asymmetric, with diffusion slowed down much more by electrostatic attraction than by repulsion, and that the filtering capability of the gel is sensitive to the solution ionic strength. Brownian dynamics simulations of a simple model are used to examine key parameters, including interaction strength and interaction range within the model networks. Simulations, which are in quantitative agreement with our experiments, reveal the charge asymmetry to be due to the sticking of particles at the vertices of the oppositely charged polymer networks.

  2. Particle Transport through Hydrogels Is Charge Asymmetric

    PubMed Central

    Zhang, Xiaolu; Hansing, Johann; Netz, Roland R.; DeRouchey, Jason E.

    2015-01-01

    Transport processes within biological polymer networks, including mucus and the extracellular matrix, play an important role in the human body, where they serve as a filter for the exchange of molecules and nanoparticles. Such polymer networks are complex and heterogeneous hydrogel environments that regulate diffusive processes through finely tuned particle-network interactions. In this work, we present experimental and theoretical studies to examine the role of electrostatics on the basic mechanisms governing the diffusion of charged probe molecules inside model polymer networks. Translational diffusion coefficients are determined by fluorescence correlation spectroscopy measurements for probe molecules in uncharged as well as cationic and anionic polymer solutions. We show that particle transport in the charged hydrogels is highly asymmetric, with diffusion slowed down much more by electrostatic attraction than by repulsion, and that the filtering capability of the gel is sensitive to the solution ionic strength. Brownian dynamics simulations of a simple model are used to examine key parameters, including interaction strength and interaction range within the model networks. Simulations, which are in quantitative agreement with our experiments, reveal the charge asymmetry to be due to the sticking of particles at the vertices of the oppositely charged polymer networks. PMID:25650921

  3. Nontargeted stressful effects in normal human fibroblast cultures exposed to low fluences of high charge, high energy (HZE) particles: kinetics of biologic responses and significance of secondary radiations.

    PubMed

    Gonon, Géraldine; Groetz, Jean-Emmanuel; de Toledo, Sonia M; Howell, Roger W; Fromm, Michel; Azzam, Edouard I

    2013-04-01

    The induction of nontargeted stressful effects in cell populations exposed to low fluences of high charge (Z) and high energy (E) particles is relevant to estimates of the health risks of space radiation. We investigated the up-regulation of stress markers in confluent normal human fibroblast cultures exposed to 1,000 MeV/u iron ions [linear energy transfer (LET) ∼151 keV/μm] or 600 MeV/u silicon ions (LET ∼50 keV/μm) at mean absorbed doses as low as 0.2 cGy, wherein 1-3% of the cells were targeted through the nucleus by a primary particle. Within 24 h postirradiation, significant increases in the levels of phospho-TP53 (serine 15), p21(Waf1) (CDKN1A), HDM2, phospho-ERK1/2, protein carbonylation and lipid peroxidation were detected, which suggested participation in the stress response of cells not targeted by primary particles. This was supported by in situ studies that indicated greater increases in 53BP1 foci formation, a marker of DNA damage. than expected from the number of primary particle traversals. The effect was expressed as early as 15 min after exposure, peaked at 1 h and decreased by 24 h. A similar tendency occurred after exposure of the cell cultures to 0.2 cGy of 3.7 MeV α particles (LET ∼109 keV/μm) that targets ∼1.6% of nuclei, but not after 0.2 cGy from 290 MeV/u carbon ions (LET ∼13 keV/μm) by which, on average, ∼13% of the nuclei were hit, which highlights the importance of radiation quality in the induced effect. Simulations with the FLUKA multi-particle transport code revealed that fragmentation products, other than electrons, in cell cultures exposed to HZE particles comprise <1% of the absorbed dose. Further, the radial spread of dose due to secondary heavy ion fragments is confined to approximately 10-20 μm. Thus, the latter are unlikely to significantly contribute to stressful effects in cells not targeted by primary HZE particles.

  4. Nontargeted stressful effects in normal human fibroblast cultures exposed to low fluences of high charge, high energy (HZE) particles: kinetics of biologic responses and significance of secondary radiations.

    PubMed

    Gonon, Géraldine; Groetz, Jean-Emmanuel; de Toledo, Sonia M; Howell, Roger W; Fromm, Michel; Azzam, Edouard I

    2013-04-01

    The induction of nontargeted stressful effects in cell populations exposed to low fluences of high charge (Z) and high energy (E) particles is relevant to estimates of the health risks of space radiation. We investigated the up-regulation of stress markers in confluent normal human fibroblast cultures exposed to 1,000 MeV/u iron ions [linear energy transfer (LET) ∼151 keV/μm] or 600 MeV/u silicon ions (LET ∼50 keV/μm) at mean absorbed doses as low as 0.2 cGy, wherein 1-3% of the cells were targeted through the nucleus by a primary particle. Within 24 h postirradiation, significant increases in the levels of phospho-TP53 (serine 15), p21(Waf1) (CDKN1A), HDM2, phospho-ERK1/2, protein carbonylation and lipid peroxidation were detected, which suggested participation in the stress response of cells not targeted by primary particles. This was supported by in situ studies that indicated greater increases in 53BP1 foci formation, a marker of DNA damage. than expected from the number of primary particle traversals. The effect was expressed as early as 15 min after exposure, peaked at 1 h and decreased by 24 h. A similar tendency occurred after exposure of the cell cultures to 0.2 cGy of 3.7 MeV α particles (LET ∼109 keV/μm) that targets ∼1.6% of nuclei, but not after 0.2 cGy from 290 MeV/u carbon ions (LET ∼13 keV/μm) by which, on average, ∼13% of the nuclei were hit, which highlights the importance of radiation quality in the induced effect. Simulations with the FLUKA multi-particle transport code revealed that fragmentation products, other than electrons, in cell cultures exposed to HZE particles comprise <1% of the absorbed dose. Further, the radial spread of dose due to secondary heavy ion fragments is confined to approximately 10-20 μm. Thus, the latter are unlikely to significantly contribute to stressful effects in cells not targeted by primary HZE particles. PMID:23465079

  5. Nontargeted Stressful Effects in Normal Human Fibroblast Cultures Exposed to Low Fluences of High Charge, High Energy (HZE) Particles: Kinetics of Biologic Responses and Significance of Secondary Radiations

    PubMed Central

    Gonon, Géraldine; Groetz, Jean-Emmanuel; de Toledo, Sonia M.; Howell, Roger W.; Fromm, Michel; Azzam, Edouard I.

    2014-01-01

    The induction of nontargeted stressful effects in cell populations exposed to low fluences of high charge (Z) and high energy (E) particles is relevant to estimates of the health risks of space radiation. We investigated the up-regulation of stress markers in confluent normal human fibroblast cultures exposed to 1,000 MeV/u iron ions [linear energy transfer (LET) ~151 keV/μm] or 600 MeV/u silicon ions (LET ~50 keV/μm) at mean absorbed doses as low as 0.2 cGy, wherein 1–3% of the cells were targeted through the nucleus by a primary particle. Within 24 h postirradiation, significant increases in the levels of phospho-TP53 (serine 15), p21Waf1 (CDKN1A), HDM2, phospho-ERK1/2, protein carbonylation and lipid peroxidation were detected, which suggested participation in the stress response of cells not targeted by primary particles. This was supported by in situ studies that indicated greater increases in 53BP1 foci formation, a marker of DNA damage. than expected from the number of primary particle traversals. The effect was expressed as early as 15 min after exposure, peaked at 1 h and decreased by 24 h. A similar tendency occurred after exposure of the cell cultures to 0.2 cGy of 3.7 MeV α particles (LET ~109 keV/μm) that targets ~1.6% of nuclei, but not after 0.2 cGy from 290 MeV/u carbon ions (LET ~13 keV/μm) by which, on average, ~13% of the nuclei were hit, which highlights the importance of radiation quality in the induced effect. Simulations with the FLUKA multi-particle transport code revealed that fragmentation products, other than electrons, in cell cultures exposed to HZE particles comprise <1% of the absorbed dose. Further, the radial spread of dose due to secondary heavy ion fragments is confined to approximately 10–20 μm. Thus, the latter are unlikely to significantly contribute to stressful effects in cells not targeted by primary HZE particles. PMID:23465079

  6. Dosimetry for Neutrons from 0.25 to 15 MeV by the Measurement of Linear Energy Transfer Distributions for Secondary Charged Particles in CR-39 Plastic

    NASA Astrophysics Data System (ADS)

    Tawara, Hiroko; Eda, Kazuyoshi; Sanami, Toshiya; Sasaki, Shinichi; Takahashi, Kazutoshi; Sonkawade, Rajendra; Nagamatsu, Aiko; Kitajo, Keiichi; Kumagai, Hidenori; Doke, Tadayoshi

    2008-03-01

    In the radiation fields of high energy accelerator facilities, high-altitude aircraft and space flights, high-energy neutron dosimetry of ˜20 MeV or more is a significant issue for radiological protection. We studied the feasibility of experimental measurements of linear energy transfer (LET) distributions for secondary charged particles induced by fast neutrons using CR-39 plastic nuclear track detectors. In order to investigate a method of analyzing the CR-39 detectors that is appropriate for fast neutron dosimetry, two-layer CR-39 stacks were exposed to monochromatic neutrons (0.25, 0.55, 5, and 15 MeV) at the Fast Neutron Laboratory of Tohoku University in Japan. We also conducted Monte Carlo calculations to estimate the detection efficiency of the CR-39 detector for recoil protons. The CR-39 detectors treated by single-step chemical etching were used to obtain LET distributions for LET > 10 keV/µm-water. The results indicated that measurements of short-range particles are very important for obtaining the correct LET distributions. Using the measured LET distributions, we calculated neutron sensitivities, absorbed doses and dose equivalents based on the ICRP 60 Q-L relation and averaged quality factors. The dose equivalents were compared with the neutron fluence-to-dose equivalent conversion factors given by ICRP 74 and the averaged quality factors were compared with weighting factors given by ICRP 60 and ICRP 92.

  7. Experimental Studying of Dust Particles Charging by Electron Beam

    SciTech Connect

    Gavrikov, A. V.; Fortov, V. E.; Petrov, O. F.; Vorona, N. A.; Vasiliev, M. N.

    2008-09-07

    The studying of the dusty plasma properties under electron beam action are of great interest because it gives the unique opportunities for experimental investigation of strongly coupled systems as well as for developing the new dusty plasma technologies of creating the new composite materials. Highly charged dust particle generates electrostatic field that can accelerate positive ions to high power. It gives the unique possibilities of using these macroparticles (for deeply ions implantation, as catalysts for increasing rate of reactions with the high energy barrier, in the new ionic engines etc.). Presented work deals with the experimental investigation of dust particles charging under direct influence of electron beam. On the basis of experimental data the average velocities of dust particles were obtained and the charge of macroparticle was estimated.

  8. Charged-particle spectroscopy in organic semiconducting single crystals

    NASA Astrophysics Data System (ADS)

    Ciavatti, A.; Sellin, P. J.; Basiricò, L.; Fraleoni-Morgera, A.; Fraboni, B.

    2016-04-01

    The use of organic materials as radiation detectors has grown, due to the easy processability in liquid phase at room temperature and the possibility to cover large areas by means of low cost deposition techniques. Direct charged-particle detectors based on solution-grown Organic Semiconducting Single Crystals (OSSCs) are shown to be capable to detect charged particles in pulse mode, with very good peak discrimination. The direct charged-particle detection in OSSCs has been assessed both in the planar and in the vertical axes, and a digital pulse processing algorithm has been used to perform pulse height spectroscopy and to study the charge collection efficiency as a function of the applied bias voltage. Taking advantage of the charge spectroscopy and the good peak discrimination of pulse height spectra, an Hecht-like behavior of OSSCs radiation detectors is demonstrated. It has been possible to estimate the mobility-lifetime value in organic materials, a fundamental parameter for the characterization of radiation detectors, whose results are equal to μτcoplanar = (5 .5 ± 0.6 ) × 10-6 cm2/V and μτsandwich = (1 .9 ± 0.2 ) × 10-6 cm2/V, values comparable to those of polycrystalline inorganic detectors. Moreover, alpha particles Time-of-Flight experiments have been carried out to estimate the drift mobility value. The results reported here indicate how charged-particle detectors based on OSSCs possess a great potential as low-cost, large area, solid-state direct detectors operating at room temperature. More interestingly, the good detection efficiency and peak discrimination observed for charged-particle detection in organic materials (hydrogen-rich molecules) are encouraging for their further exploitation in the detection of thermal and high-energy neutrons.

  9. Induction of chromosome aberrations in human cells by charged particles

    NASA Technical Reports Server (NTRS)

    Wu, H.; Durante, M.; George, K.; Yang, T. C.

    1997-01-01

    Chromosome aberrations induced by high-energy charged particles in normal human lymphocytes and human fibroblasts have been investigated. The charged particles included 250 MeV/nucleon protons, 290 MeV/nucleon carbon ions and 1 GeV/nucleon iron ions. The energies of the charged particles were higher than in most of the studies reported in the literature. Lymphocytes were stimulated to grow immediately after irradiation, while fibroblasts were incubated at 37 degrees C for 24 h for repair. Chromosomes were collected at the first mitosis after irradiation and chromosome aberrations were scored using the fluorescence in situ hybridization (FISH) technique with a whole-chromosome 4 probe. Chromosome aberrations were classified as reciprocal exchanges, incomplete exchanges, deletions and complex exchanges. The relative biological effectiveness (RBE) for each type of aberration was calculated by dividing a dose of 4 Gy by the dose of the charged particles producing the same effect as 4 Gy of gamma rays. Results of this study showed that complex aberrations have the highest RBE for radiation of high linear energy transfer (LET) for human lymphocytes, but for fibroblasts, the greatest effect was for incomplete exchanges. For both lymphocytes and fibroblasts, iron ions induced a similar fraction of aberrant cells.

  10. Screening of charged spheroidal colloidal particles

    NASA Astrophysics Data System (ADS)

    Álvarez, Carlos; Téllez, Gabriel

    2010-10-01

    We study the effective screened electrostatic potential created by a spheroidal colloidal particle immersed in an electrolyte, within the mean field approximation, using Poisson-Boltzmann equation in its linear and nonlinear forms, and also beyond the mean field by means of Monte Carlo computer simulation. The anisotropic shape of the particle has a strong effect on the screened potential, even at large distances (compared to the Debye length) from it. To quantify this anisotropy effect, we focus our study on the dependence of the potential on the position of the observation point with respect with the orientation of the spheroidal particle. For several different boundary conditions (constant potential, or constant surface charge) we find that, at large distance, the potential is higher in the direction of the large axis of the spheroidal particle.

  11. Guiding of charged particles through capillaries in insulating materials

    NASA Astrophysics Data System (ADS)

    Stolterfoht, Nikolaus; Yamazaki, Yasunori

    2016-04-01

    Studies of charged particle guiding through capillaries in insulating materials, performed during the last decade, are reviewed in a comprehensive manner. First, the principles of capillary guiding of slow highly charged ions are introduced describing the self-organized formation of charge patches. Basic quantities are defined, such as the guiding power characterizing a capillary. Challenges of the guiding experiments are pointed out. Then, experiments are described with emphasis on the guiding of highly charged ions in the keV energy range. Samples with an array of nanocapillaries as well as single macrocapillaries are treated. Emission profiles of transmitted ions are analyzed to establish scaling laws for the guiding angle, which quantifies the guiding power. Oscillations of the mean ion emission angle reveal the temporal dynamics of the charge patch formation. Next, experiments with ions of high (MeV) energies are focused on single tapered capillaries allowing for the production of a microbeam for various applications. Experiments concerning electrons are presented showing that apart from being elastically scattered these negative particles may enter into the capillary surface where they suffer energy losses. Finally, theoretical concepts of the capillary guiding are discussed. Simulations based on different charge transport methods clearly support the understanding of the guiding mechanisms. Altogether, capillary guiding involves several novel phenomena for which understanding have progressed far beyond their infancy.

  12. Charged-Particle Impact Ionization of Atoms

    SciTech Connect

    Bartschat, Klaus; Guan Xiaoxu

    2008-08-08

    We have developed a hybrid method to treat charged-particle impact ionization of complex atoms and ions. The essential idea is to describe the interaction between a fast projectile and the target perturbatively, up to second order, while the initial bound state and the ejected-electron--residual-ion interaction can be handled via a convergent R-matrix with pseudo-states (close-coupling) expansion. Example results for ionization of the heavy noble gases (Ne-Xe) by positron and electron impact are presented. The general scheme for a distorted-wave treatment of ionization by heavy-particle impact is described.

  13. Position Sensitive Detection System for Charged Particles

    SciTech Connect

    Coello, E. A.; Favela, F.; Curiel, Q.; Chavez, E; Huerta, A.; Varela, A.; Shapira, Dan

    2012-01-01

    The position sensitive detection system presented in this work employs the Anger logic algorithm to determine the position of the light spark produced by the passage of charged particles on a 170 x 170 x 10 mm3 scintillator material (PILOT-U). The detection system consists of a matrix of nine photomultipliers, covering a fraction of the back area of the scintillators. Tests made with a non-collimated alpha particle source together with a Monte Carlo simulation that reproduces the data, suggest an intrinsic position resolution of up to 6 mm is achieved.

  14. High-LET charged particle radiotherapy

    SciTech Connect

    Castro, J.R. . Research Medicine and Radiation Biophysics Div. California Univ., San Francisco, CA . Dept. of Radiation Oncology)

    1991-07-01

    The Department of Radiation Oncology at UCSF Medical Center and the Radiation Oncology Department at UC Lawrence Berkeley Laboratory have been evaluating the use of high LET charged particle radiotherapy in a Phase 1--2 research trial ongoing since 1979. In this clinical trail, 239 patients have received at least 10 Gy (physical) minimum tumor dose with neon ions, meaning that at least one-half of their total treatment was given with high-LET charged particle therapy. Ninety-one patients received all of their therapy with neon ions. Of the 239 patients irradiated, target sites included lesions in the skin, subcutaneous tissues, head and neck such as paranasal sinuses, nasopharynx and salivary glands (major and minor), skull base and juxtaspinal area, GI tract including esophagus, pancreas and biliary tract, prostate, lung, soft tissue and bone. Analysis of these patients has been carried out with a minimum followup period of 2 years.

  15. Method and apparatus for charged particle propagation

    DOEpatents

    Hershcovitch, A.

    1996-11-26

    A method and apparatus are provided for propagating charged particles from a vacuum to a higher pressure region. A generator includes an evacuated chamber having a gun for discharging a beam of charged particles such as an electron beam or ion beam. The beam is discharged through a beam exit in the chamber into a higher pressure region. A plasma interface is disposed at the beam exit and includes a plasma channel for bounding a plasma maintainable between a cathode and an anode disposed at opposite ends thereof. The plasma channel is coaxially aligned with the beam exit for propagating the beam from the chamber, through the plasma, and into the higher pressure region. The plasma is effective for pumping down the beam exit for preventing pressure increase in the chamber and provides magnetic focusing of the beam discharged into the higher pressure region 24. 7 figs.

  16. Charged Particle Therapy for Hepatocellular Carcinoma

    PubMed Central

    Skinner, Heath D.; Hong, Theodore S.; Krishnan, Sunil

    2011-01-01

    Historically, the use of external beam radiotherapy for hepatocellular carcinoma (HCC) has been limited by toxicity to the uninvolved liver and surrounding structures. Advances in photon radiotherapy have improved dose conformality to the tumor and facilitated dose escalation, a key contributor to improved HCC radiation treatment outcomes. However, despite these advances in photon radiotherapy, significant volumes of liver still receive low doses of radiation that can preclude dose escalation, particularly in patients with limited functional liver reserves. By capitalizing on the lack of exit dose along the beam path beyond the tumor and higher biological effectiveness, charged particle therapy offers the promise of maximizing tumor control via dose escalation without excessive liver toxicity. In this review we discuss the distinctive biophysical attributes of both proton and carbon ion radiotherapy, particularly as they pertain to treatment of HCC. We also review the available literature regarding clinical outcomes and toxicity of using charged particles for the treatment of HCC. PMID:21939857

  17. High gradient lens for charged particle beam

    SciTech Connect

    Chen, Yu-Jiuan

    2014-04-29

    Methods and devices enable shaping of a charged particle beam. A dynamically adjustable electric lens includes a series of alternating a series of alternating layers of insulators and conductors with a hollow center. The series of alternating layers when stacked together form a high gradient insulator (HGI) tube to allow propagation of the charged particle beam through the hollow center of the HGI tube. A plurality of transmission lines are connected to a plurality of sections of the HGI tube, and one or more voltage sources are provided to supply an adjustable voltage value to each transmission line of the plurality of transmission lines. By changing the voltage values supplied to each section of the HGI tube, any desired electric field can be established across the HGI tube. This way various functionalities including focusing, defocusing, acceleration, deceleration, intensity modulation and others can be effectuated on a time varying basis.

  18. HIGH ENERGY PARTICLE ACCELERATOR

    DOEpatents

    Courant, E.D.; Livingston, M.S.; Snyder, H.S.

    1959-04-14

    An improved apparatus is presented for focusing charged particles in an accelerator. In essence, the invention includes means for establishing a magnetic field in discrete sectors along the path of moving charged particles, the magnetic field varying in each sector in accordance with the relation. B = B/ sub 0/ STAln (r-r/sub 0/)/r/sub 0/!, where B/sub 0/ is the value of the magnetic field at the equilibrium orbit of radius r/sub 0/ of the path of the particles, B equals the magnetic field at the radius r of the chamber and n equals the magnetic field gradient index, the polarity of n being abruptly reversed a plurality of times as the particles travel along their arcuate path. With this arrangement, the particles are alternately converged towards the axis of their equillbrium orbit and diverged therefrom in successive sectors with a resultant focusing effect.

  19. Charged Particle Environment Definition for NGST: Model Development

    NASA Technical Reports Server (NTRS)

    Blackwell, William C.; Minow, Joseph I.; Evans, Steven W.; Hardage, Donna M.; Suggs, Robert M.

    2000-01-01

    NGST will operate in a halo orbit about the L2 point, 1.5 million km from the Earth, where the spacecraft will periodically travel through the magnetotail region. There are a number of tools available to calculate the high energy, ionizing radiation particle environment from galactic cosmic rays and from solar disturbances. However, space environment tools are not generally available to provide assessments of charged particle environment and its variations in the solar wind, magnetosheath, and magnetotail at L2 distances. An engineering-level phenomenology code (LRAD) was therefore developed to facilitate the definition of charged particle environments in the vicinity of the L2 point in support of the NGST program. LRAD contains models tied to satellite measurement data of the solar wind and magnetotail regions. The model provides particle flux and fluence calculations necessary to predict spacecraft charging conditions and the degradation of materials used in the construction of NGST. This paper describes the LRAD environment models for the deep magnetotail (XGSE < -100 Re) and solar wind, and presents predictions of the charged particle environment for NGST.

  20. Ball Rolling on a Turntable: Analog for Charged Particle Dynamics.

    ERIC Educational Resources Information Center

    Burns, Joseph A.

    1981-01-01

    Describes how a ball's motion duplicates that of a charged particle moving through a magnetic field and thereby allows students to visualize directly many aspects of charged particle dynamics otherwise not accessible to them. (Author/JN)

  1. The Influence of Particle Charge on Heterogeneous Reaction Rate Coefficients

    NASA Technical Reports Server (NTRS)

    Aikin, A. C.; Pesnell, W. D.

    2000-01-01

    The effects of particle charge on heterogeneous reaction rates are presented. Many atmospheric particles, whether liquid or solid are charged. This surface charge causes a redistribution of charge within a liquid particle and as a consequence a perturbation in the gaseous uptake coefficient. The amount of perturbation is proportional to the external potential and the square of the ratio of debye length in the liquid to the particle radius. Previous modeling has shown how surface charge affects the uptake coefficient of charged aerosols. This effect is now included in the heterogeneous reaction rate of an aerosol ensemble. Extension of this analysis to ice particles will be discussed and examples presented.

  2. Radiation reaction for a massless charged particle

    NASA Astrophysics Data System (ADS)

    Kazinski, P. O.; Sharapov, A. A.

    2003-07-01

    We derive effective equations of motion for a massless charged particle coupled to the dynamical electromagnetic field with regard to the radiation back reaction. It is shown that unlike the massive case, not all the divergences resulting from the self-action of the particle are Lagrangian, i.e., can be cancelled out by adding appropriate counterterms to the original action. Besides, the order of renormalized differential equations governing the effective dynamics turns out to be greater than the order of the corresponding Lorentz-Dirac equation for a massive particle. For the case of a homogeneous external field, the first radiative correction to the Lorentz equation is explicitly derived via the reduction of order procedure.

  3. Charged particle acceleration in nonuniform plasmas

    SciTech Connect

    Bulanov, S.V.; Naumova, N.M.; Dudnikova, G.I.; Vshivkov, V.A.; Pegoraro, F.; Pogorelsky, I.V.

    1996-11-01

    The high-gradient electron acceleration schemes that have been demonstrated using LWFA appear promising for the development of plasma-based laser accelerators into practical devices. However, a question still exists: how to avoid the wake field deterioration and the loss of the phase synchronism between the plasma wave and the electrons that prevent them from being accelerated up to the theoretical limit. In order to obtain the highest possible values of the wake electric field one must use as intense laser pulses as possible i.e., pulses with dimensionless amplitudes a {much_gt} 1. Pulses that have a dimensionless amplitude larger than one tend to be subject to a host of instabilities, such as relativistic self-focusing, self modulation and stimulated Raman scattering, that affect their propagation in the plasma. Such processes could be beneficial, in so far as they increase the pulse energy density, enhance the wake field generation, and provide the mechanism for transporting the laser radiation over several Rayleigh lengths without diffraction spreading. However, it is still far from certain that these processes can be exploited in a controlled form and can lead to regular, stationary wake fields. It is known that, in order to create good quality wake fields, it would be preferable to use laser pulses with steep fronts of order {lambda}{sub p}. The present paper aims at analyzing the influence of the laser pulse shape and of the plasma nonuniformity on the charged particle acceleration. This study is based on the results obtained with one dimensional PIC simulations.

  4. Transverse energy production and charged-particle multiplicity at midrapidity in various systems from √{sN N}=7.7 to 200 GeV

    NASA Astrophysics Data System (ADS)

    Adare, A.; Afanasiev, S.; Aidala, C.; Ajitanand, N. N.; Akiba, Y.; Akimoto, R.; Al-Bataineh, H.; Alexander, J.; Alfred, M.; Al-Jamel, A.; Al-Ta'Ani, H.; Angerami, A.; Aoki, K.; Apadula, N.; Aphecetche, L.; Aramaki, Y.; Armendariz, R.; Aronson, S. H.; Asai, J.; Asano, H.; Aschenauer, E. C.; Atomssa, E. T.; Averbeck, R.; Awes, T. C.; Azmoun, B.; Babintsev, V.; Bai, M.; Bai, X.; Baksay, G.; Baksay, L.; Baldisseri, A.; Bandara, N. S.; Bannier, B.; Barish, K. N.; Barnes, P. D.; Bassalleck, B.; Basye, A. T.; Bathe, S.; Batsouli, S.; Baublis, V.; Bauer, F.; Baumann, C.; Baumgart, S.; Bazilevsky, A.; Beaumier, M.; Beckman, S.; Belikov, S.; Belmont, R.; Bennett, R.; Berdnikov, A.; Berdnikov, Y.; Bhom, J. H.; Bickley, A. A.; Bjorndal, M. T.; Black, D.; Blau, D. S.; Boissevain, J. G.; Bok, J. S.; Borel, H.; Boyle, K.; Brooks, M. L.; Brown, D. S.; Bryslawskyj, J.; Bucher, D.; Buesching, H.; Bumazhnov, V.; Bunce, G.; Burward-Hoy, J. M.; Butsyk, S.; Campbell, S.; Caringi, A.; Castera, P.; Chai, J.-S.; Chang, B. S.; Charvet, J.-L.; Chen, C.-H.; Chernichenko, S.; Chi, C. Y.; Chiba, J.; Chiu, M.; Choi, I. J.; Choi, J. B.; Choi, S.; Choudhury, R. K.; Christiansen, P.; Chujo, T.; Chung, P.; Churyn, A.; Chvala, O.; Cianciolo, V.; Citron, Z.; Cleven, C. R.; Cobigo, Y.; Cole, B. A.; Comets, M. P.; Conesa Del Valle, Z.; Connors, M.; Constantin, P.; Cronin, N.; Crossette, N.; Csanád, M.; Csörgő, T.; Dahms, T.; Dairaku, S.; Danchev, I.; Danley, T. W.; Das, K.; Datta, A.; Daugherity, M. S.; David, G.; Dayananda, M. K.; Deaton, M. B.; Deblasio, K.; Dehmelt, K.; Delagrange, H.; Denisov, A.; D'Enterria, D.; Deshpande, A.; Desmond, E. J.; Dharmawardane, K. V.; Dietzsch, O.; Ding, L.; Dion, A.; Diss, P. B.; Do, J. H.; Donadelli, M.; D'Orazio, L.; Drachenberg, J. L.; Drapier, O.; Drees, A.; Drees, K. A.; Dubey, A. K.; Durham, J. M.; Durum, A.; Dutta, D.; Dzhordzhadze, V.; Edwards, S.; Efremenko, Y. V.; Egdemir, J.; Ellinghaus, F.; Emam, W. S.; Engelmore, T.; Enokizono, A.; En'yo, H.; Espagnon, B.; Esumi, S.; Eyser, K. O.; Fadem, B.; Feege, N.; Fields, D. E.; Finger, M.; Finger, M.; Fleuret, F.; Fokin, S. L.; Forestier, B.; Fraenkel, Z.; Frantz, J. E.; Franz, A.; Frawley, A. D.; Fujiwara, K.; Fukao, Y.; Fung, S.-Y.; Fusayasu, T.; Gadrat, S.; Gainey, K.; Gal, C.; Gallus, P.; Garg, P.; Garishvili, A.; Garishvili, I.; Gastineau, F.; Ge, H.; Germain, M.; Giordano, F.; Glenn, A.; Gong, H.; Gong, X.; Gonin, M.; Gosset, J.; Goto, Y.; Granier de Cassagnac, R.; Grau, N.; Greene, S. V.; Grim, G.; Grosse Perdekamp, M.; Gu, Y.; Gunji, T.; Guo, L.; Guragain, H.; Gustafsson, H.-Å.; Hachiya, T.; Hadj Henni, A.; Haegemann, C.; Haggerty, J. S.; Hagiwara, M. N.; Hahn, K. I.; Hamagaki, H.; Hamblen, J.; Hamilton, H. F.; Han, R.; Han, S. Y.; Hanks, J.; Harada, H.; Hartouni, E. P.; Haruna, K.; Harvey, M.; Hasegawa, S.; Haseler, T. O. S.; Hashimoto, K.; Haslum, E.; Hasuko, K.; Hayano, R.; Hayashi, S.; He, X.; Heffner, M.; Hemmick, T. K.; Hester, T.; Heuser, J. M.; Hiejima, H.; Hill, J. C.; Hobbs, R.; Hohlmann, M.; Hollis, R. S.; Holmes, M.; Holzmann, W.; Homma, K.; Hong, B.; Horaguchi, T.; Hori, Y.; Hornback, D.; Hoshino, T.; Hotvedt, N.; Huang, J.; Huang, S.; Hur, M. G.; Ichihara, T.; Ichimiya, R.; Iinuma, H.; Ikeda, Y.; Imai, K.; Imazu, Y.; Imrek, J.; Inaba, M.; Inoue, Y.; Iordanova, A.; Isenhower, D.; Isenhower, L.; Ishihara, M.; Isinhue, A.; Isobe, T.; Issah, M.; Isupov, A.; Ivanishchev, D.; Iwanaga, Y.; Jacak, B. V.; Javani, M.; Jeon, S. J.; Jezghani, M.; Jia, J.; Jiang, X.; Jin, J.; Jinnouchi, O.; Johnson, B. M.; Jones, T.; Joo, K. S.; Jouan, D.; Jumper, D. S.; Kajihara, F.; Kametani, S.; Kamihara, N.; Kamin, J.; Kanda, S.; Kaneta, M.; Kaneti, S.; Kang, B. H.; Kang, J. H.; Kang, J. S.; Kanou, H.; Kapustinsky, J.; Karatsu, K.; Kasai, M.; Kawagishi, T.; Kawall, D.; Kawashima, M.; Kazantsev, A. V.; Kelly, S.; Kempel, T.; Key, J. A.; Khachatryan, V.; Khandai, P. K.; Khanzadeev, A.; Kijima, K. M.; Kikuchi, J.; Kim, A.; Kim, B. I.; Kim, C.; Kim, D. H.; Kim, D. J.; Kim, E.; Kim, E.-J.; Kim, G. W.; Kim, H. J.; Kim, K.-B.; Kim, M.; Kim, Y.-J.; Kim, Y. K.; Kim, Y.-S.; Kimelman, B.; Kinney, E.; Kiss, Á.; Kistenev, E.; Kitamura, R.; Kiyomichi, A.; Klatsky, J.; Klay, J.; Klein-Boesing, C.; Kleinjan, D.; Kline, P.; Koblesky, T.; Kochenda, L.; Kochetkov, V.; Kofarago, M.; Komatsu, Y.; Komkov, B.; Konno, M.; Koster, J.; Kotchetkov, D.; Kotov, D.; Kozlov, A.; Král, A.; Kravitz, A.; Krizek, F.; Kroon, P. J.; Kubart, J.; Kunde, G. J.; Kurihara, N.; Kurita, K.; Kurosawa, M.; Kweon, M. J.; Kwon, Y.; Kyle, G. S.; Lacey, R.; Lai, Y. S.; Lajoie, J. G.; Lebedev, A.; Le Bornec, Y.; Leckey, S.; Lee, B.; Lee, D. M.; Lee, G. H.; Lee, J.; Lee, K. B.; Lee, K. S.; Lee, M. K.; Lee, S.; Lee, S. H.; Lee, S. R.; Lee, T.; Leitch, M. J.; Leite, M. A. L.; Leitgab, M.; Lenzi, B.; Lewis, B.; Li, X.; Li, X. H.; Lichtenwalner, P.; Liebing, P.; Lim, H.; Lim, S. H.; Linden Levy, L. A.; Liška, T.; Litvinenko, A.; Liu, H.; Liu, M. X.; Love, B.; Lynch, D.; Maguire, C. F.; Makdisi, Y. I.; Makek, M.; Malakhov, A.; Malik, M. D.; Manion, A.; Manko, V. I.; Mannel, E.; Mao, Y.; Maruyama, T.; Mašek, L.; Masui, H.; Masumoto, S.; Matathias, F.; McCain, M. C.; McCumber, M.; McGaughey, P. L.; McGlinchey, D.; McKinney, C.; Means, N.; Meles, A.; Mendoza, M.; Meredith, B.; Miake, Y.; Mibe, T.; Midori, J.; Mignerey, A. C.; Mikeš, P.; Miki, K.; Miller, T. E.; Milov, A.; Mioduszewski, S.; Mishra, D. K.; Mishra, G. C.; Mishra, M.; Mitchell, J. T.; Mitrovski, M.; Miyachi, Y.; Miyasaka, S.; Mizuno, S.; Mohanty, A. K.; Mohapatra, S.; Montuenga, P.; Moon, H. J.; Moon, T.; Morino, Y.; Morreale, A.; Morrison, D. P.; Moskowitz, M.; Moss, J. M.; Motschwiller, S.; Moukhanova, T. V.; Mukhopadhyay, D.; Murakami, T.; Murata, J.; Mwai, A.; Nagae, T.; Nagamiya, S.; Nagashima, K.; Nagata, Y.; Nagle, J. L.; Naglis, M.; Nagy, M. I.; Nakagawa, I.; Nakagomi, H.; Nakamiya, Y.; Nakamura, K. R.; Nakamura, T.; Nakano, K.; Nam, S.; Nattrass, C.; Nederlof, A.; Netrakanti, P. K.; Newby, J.; Nguyen, M.; Nihashi, M.; Niida, T.; Nishimura, S.; Norman, B. E.; Nouicer, R.; Novák, T.; Novitzky, N.; Nukariya, A.; Nyanin, A. S.; Nystrand, J.; Oakley, C.; Obayashi, H.; O'Brien, E.; Oda, S. X.; Ogilvie, C. A.; Ohnishi, H.; Oide, H.; Ojha, I. D.; Oka, M.; Okada, K.; Omiwade, O. O.; Onuki, Y.; Orjuela Koop, J. D.; Osborn, J. D.; Oskarsson, A.; Otterlund, I.; Ouchida, M.; Ozawa, K.; Pak, R.; Pal, D.; Palounek, A. P. T.; Pantuev, V.; Papavassiliou, V.; Park, B. H.; Park, I. H.; Park, J.; Park, J. S.; Park, S.; Park, S. K.; Park, W. J.; Pate, S. F.; Patel, L.; Patel, M.; Pei, H.; Peng, J.-C.; Pereira, H.; Perepelitsa, D. V.; Perera, G. D. N.; Peresedov, V.; Peressounko, D. Yu.; Perry, J.; Petti, R.; Pinkenburg, C.; Pinson, R.; Pisani, R. P.; Proissl, M.; Purschke, M. L.; Purwar, A. K.; Qu, H.; Rak, J.; Rakotozafindrabe, A.; Ramson, B. J.; Ravinovich, I.; Read, K. F.; Rembeczki, S.; Reuter, M.; Reygers, K.; Reynolds, D.; Riabov, V.; Riabov, Y.; Richardson, E.; Rinn, T.; Riveli, N.; Roach, D.; Roche, G.; Rolnick, S. D.; Romana, A.; Rosati, M.; Rosen, C. A.; Rosendahl, S. S. E.; Rosnet, P.; Rowan, Z.; Rubin, J. G.; Rukoyatkin, P.; Ružička, P.; Rykov, V. L.; Ryu, M. S.; Ryu, S. S.; Sahlmueller, B.; Saito, N.; Sakaguchi, T.; Sakai, S.; Sakashita, K.; Sakata, H.; Sako, H.; Samsonov, V.; Sano, M.; Sano, S.; Sarsour, M.; Sato, H. D.; Sato, S.; Sato, T.; Sawada, S.; Schaefer, B.; Schmoll, B. K.; Sedgwick, K.; Seele, J.; Seidl, R.; Sekiguchi, Y.; Semenov, V.; Sen, A.; Seto, R.; Sett, P.; Sexton, A.; Sharma, D.; Shaver, A.; Shea, T. K.; Shein, I.; Shevel, A.; Shibata, T.-A.; Shigaki, K.; Shimomura, M.; Shohjoh, T.; Shoji, K.; Shukla, P.; Sickles, A.; Silva, C. L.; Silvermyr, D.; Silvestre, C.; Sim, K. S.; Singh, B. K.; Singh, C. P.; Singh, V.; Skolnik, M.; Skutnik, S.; Slunečka, M.; Smith, W. C.; Snowball, M.; Solano, S.; Soldatov, A.; Soltz, R. A.; Sondheim, W. E.; Sorensen, S. P.; Sourikova, I. V.; Staley, F.; Stankus, P. W.; Steinberg, P.; Stenlund, E.; Stepanov, M.; Ster, A.; Stoll, S. P.; Stone, M. R.; Sugitate, T.; Suire, C.; Sukhanov, A.; Sullivan, J. P.; Sumita, T.; Sun, J.; Sziklai, J.; Tabaru, T.; Takagi, S.; Takagui, E. M.; Takahara, A.; Taketani, A.; Tanabe, R.; Tanaka, K. H.; Tanaka, Y.; Taneja, S.; Tanida, K.; Tannenbaum, M. J.; Tarafdar, S.; Taranenko, A.; Tarján, P.; Tennant, E.; Themann, H.; Thomas, D.; Thomas, T. L.; Tieulent, R.; Timilsina, A.; Todoroki, T.; Togawa, M.; Toia, A.; Tojo, J.; Tomášek, L.; Tomášek, M.; Torii, H.; Towell, C. L.; Towell, R.; Towell, R. S.; Tram, V.-N.; Tserruya, I.; Tsuchimoto, Y.; Tsuji, T.; Tuli, S. K.; Tydesjö, H.; Tyurin, N.; Vale, C.; Valle, H.; van Hecke, H. W.; Vargyas, M.; Vazquez-Zambrano, E.; Veicht, A.; Velkovska, J.; Vértesi, R.; Vinogradov, A. A.; Virius, M.; Voas, B.; Vossen, A.; Vrba, V.; Vznuzdaev, E.; Wagner, M.; Walker, D.; Wang, X. R.; Watanabe, D.; Watanabe, K.; Watanabe, Y.; Watanabe, Y. S.; Wei, F.; Wei, R.; Wessels, J.; Whitaker, S.; White, A. S.; White, S. N.; Willis, N.; Winter, D.; Wolin, S.; Woody, C. L.; Wright, R. M.; Wysocki, M.; Xia, B.; Xie, W.; Xue, L.; Yalcin, S.; Yamaguchi, Y. L.; Yamaura, K.; Yang, R.; Yanovich, A.; Yasin, Z.; Ying, J.; Yokkaichi, S.; Yoo, J. H.; Yoon, I.; You, Z.; Young, G. R.; Younus, I.; Yu, H.; Yushmanov, I. E.; Zajc, W. A.; Zaudtke, O.; Zelenski, A.; Zhang, C.; Zhou, S.; Zimamyi, J.; Zolin, L.; Zou, L.; Phenix Collaboration

    2016-02-01

    Measurements of midrapidity charged-particle multiplicity distributions, d Nch/d η , and midrapidity transverse-energy distributions, d ET/d η , are presented for a variety of collision systems and energies. Included are distributions for Au +Au collisions at √{sNN}=200 , 130, 62.4, 39, 27, 19.6, 14.5, and 7.7 GeV, Cu +Cu collisions at √{sNN}=200 and 62.4 GeV, Cu +Au collisions at √{sNN}=200 GeV, U +U collisions at √{sNN}=193 GeV, d +Au collisions at √{sNN}=200 GeV, 3He+Au collisions at √{sNN}=200 GeV, and p +p collisions at √{sNN}=200 GeV. Centrality-dependent distributions at midrapidity are presented in terms of the number of nucleon participants, Npart, and the number of constituent quark participants, Nqp. For all A +A collisions down to √{sNN}=7.7 GeV, it is observed that the midrapidity data are better described by scaling with Nqp than scaling with Npart. Also presented are estimates of the Bjorken energy density, ɛBJ, and the ratio of d ET/d η to d Nch/d η , the latter of which is seen to be constant as a function of centrality for all systems.

  5. Charged particle optics without detailed field maps

    NASA Astrophysics Data System (ADS)

    Carey, David C.

    1993-12-01

    For the initial design of a beam line or charged particle optical system, it is both useful and convenient to be able to describe the components in terms of a small number of parameters. These parameters are used in a calculation of a transfer map which represents the effect of the beam line on a particle trajectory. The transfer map is often expressed as some kind of series expansion. A calculation to first order requires the smallest number of descriptive parameters. Extension of the calculation to higher orders requires a greater number of parameters. From our mathematical backgrounds we have come to have certain expectations as to the characteristics of a series expansion. These expectations may not always be commensurate with the physics of charged particle beam lines. The reconciliation of these expectations will be discussed. The example used will be the program TRANSPORT and its extension to third order. The third-order expansion may represent the inherent limit of the series representation without numerical integration. We shall explain why we may have reached that limit.

  6. Alpha particles diffusion due to charge changes

    SciTech Connect

    Clauser, C. F. Farengo, R.

    2015-12-15

    Alpha particles diffusion due to charge changes in a magnetized plasma is studied. Analytical calculations and numerical simulations are employed to show that this process can be very important in the pedestal-edge-SOL regions. This is the first study that presents clear evidence of the importance of atomic processes on the diffusion of alpha particles. A simple 1D model that includes inelastic collisions with plasma species, “cold” neutrals, and partially ionized species was employed. The code, which follows the exact particle orbits and includes the effect of inelastic collisions via a Monte Carlo type random process, runs on a graphic processor unit (GPU). The analytical and numerical results show excellent agreement when a uniform background (plasma and cold species) is assumed. The simulations also show that the gradients in the density of the plasma and cold species, which are large and opposite in the edge region, produce an inward flux of alpha particles. Calculations of the alpha particles flux reaching the walls or divertor plates should include these processes.

  7. Alpha particles diffusion due to charge changes

    NASA Astrophysics Data System (ADS)

    Clauser, C. F.; Farengo, R.

    2015-12-01

    Alpha particles diffusion due to charge changes in a magnetized plasma is studied. Analytical calculations and numerical simulations are employed to show that this process can be very important in the pedestal-edge-SOL regions. This is the first study that presents clear evidence of the importance of atomic processes on the diffusion of alpha particles. A simple 1D model that includes inelastic collisions with plasma species, "cold" neutrals, and partially ionized species was employed. The code, which follows the exact particle orbits and includes the effect of inelastic collisions via a Monte Carlo type random process, runs on a graphic processor unit (GPU). The analytical and numerical results show excellent agreement when a uniform background (plasma and cold species) is assumed. The simulations also show that the gradients in the density of the plasma and cold species, which are large and opposite in the edge region, produce an inward flux of alpha particles. Calculations of the alpha particles flux reaching the walls or divertor plates should include these processes.

  8. Charged particle beam current monitoring tutorial

    SciTech Connect

    Webber, R.C.

    1994-10-01

    A tutorial presentation is made on topics related to the measurement of charged particle beam currents. The fundamental physics of electricity and magnetism pertinent to the problem is reviewed. The physics is presented with a stress on its interpretation from an electrical circuit theory point of view. The operation of devices including video pulse current transformers, direct current transformers, and gigahertz bandwidth wall current style transformers is described. Design examples are given for each of these types of devices. Sensitivity, frequency response, and physical environment are typical parameters which influence the design of these instruments in any particular application. Practical engineering considerations, potential pitfalls, and performance limitations are discussed.

  9. Scanning energy analyzer of charge exchange atoms

    SciTech Connect

    Rogozin, A.I.; Shikhovtsev, I.V.

    1994-12-31

    The construction, operation principle, and parameters of multichannel scanning energy analyzer of charge exchange atoms are discussed. The analyzer is used to measure the splashing ion angular distribution and energy spectra, the ions being produced in a gas dynamic plasma trap (GDCS) during the injection of powerful atomic hydrogen beam into preliminary produced plasma with density n {approx_equal} 5 {times} 10{sup 13} cm{sup {minus}3}. The parameters of the hydrogen beam are as follows: particle energy -50 keV, equivalent current -250 A, pulse duration -1 ms. The device can be also used for measurements of energy spectra of atomic and charged particle beams in plasma diagnostics, beam physics, and physics of atomic collisions. 4 refs., 4 figs.

  10. Spallation nucleosynthesis by accelerated charged-particles

    SciTech Connect

    Goriely, S.

    2008-05-12

    Recent observations have suggested the presence of radioactive elements, such as Pm and 84{<=}Z{<=}99 elements) at the surface of the magnetic star HD101065, also known as Przybylski's star. This star is know to be a chemically peculiar star and its anomalous 38charged-particles, mainly protons and {alpha}-particles, that in turn can by interaction with the stellar material modify the surface content.The present contribution explores to what extent the spallation processes resulting from the interaction of the stellar material with stellar energetic particle can by themselves only explain the abundances determined by observation at the surface of HD101065. We show that specific parametric simulations can explain many different observational aspects, and in particular that a significant production of Z>30 heavy elements can be achieved. In this nucleosynthesis process, the secondary-neutron captures play a crucial role. The most attractive feature of the spallation process is the systematic production of Pm and Tc and the possible synthesis of actinides and sub-actinides.Based on such a parametric model, it is also shown that intense fluences of accelerated charged-particles interacting with surrounding material can efficiently produce elements heavier than iron. Different regimes are investigated and shown to be at the origin of p- and s-nuclei in the case of high-fluence low-flux events and r-nuclei for high-fluence high-flux irradiations. The possible existence of such irradiation events need to be confirmed by hydrodynamics simulations, but most of all by spectroscopic observations through the detection of short-lived radio-elements.

  11. Charged particle LET-spectra measurements aboard LDEF

    NASA Technical Reports Server (NTRS)

    Csige, I.; Benton, E. V.; Frank, A. L.; Frigo, L. A.; Benton, E. R.; Parnell, T. A.; Watts, J. W., Jr.

    1992-01-01

    The linear energy transfer (LET) spectra of charged particles was measured in the 5 to 250 keV/micron (water) interval with CR-39 and in the 500 to 1500 keV/micron (water) interval with polycarbonate plastic nuclear track detectors (PNTDs) under different shielding depths in the P0006 experiment. The optimal processing conditions were determined for both PNTDs in relation to the relatively high track densities due to the long term exposure in space. The total track density was measured over the selected samples, and tracks in coincidence on the facing surfaces of two detector sheets were selected for measuring at the same position on each sheet. The short range (SR) and Galactic Cosmic Ray (GCR) components were measured separately with CR-39 PNTDs and the integral dose and dose rate spectra of charged particles were also determined. The high LET portion of the LET spectra was measured with polycarbonate PNTDs with high statistical accuracy. This is a unique result of this exposure due to the low flux of these types of particles for typical spaceflight durations. The directional dependence of the charged particles at the position of the P0006 experiment was also studied by four small side stacks which surrounded the main stack and by analyzing the dip angle and polar angle distributions of the measured SR and GCR particle tracks in the main stack.

  12. Mapping of electrical potential distributions with charged particle beams

    NASA Technical Reports Server (NTRS)

    Robinson, J. W.

    1982-01-01

    Methods for measuring electrostatic potentials on and near dielectric surfaces charged to several kilovolts are studied. Secondary emission from those charged dielectrics is measured. Candidates for potential measurement include the induced charge, from which potential is calculated; the trajectory endpoints of either high or low energy particles traversing the region near the surface; trajectory impact on the surface; and creating ions at points of interest near the surface. Some of the methods require computer simulations and iterative calculation if potential maps are to be generated. Several approaches are described and compared. A method using a half-cylinder as a test chamber and low-energy probing beams is adapted for the measurement of seconary emission.

  13. Quantum-size effects in the energy loss of charged particles interacting with a confined two-dimensional electron gas

    SciTech Connect

    Borisov, A. G.; Juaristi, J. I.

    2006-01-15

    Time-dependent density-functional theory is used to calculate quantum-size effects in the energy loss of antiprotons interacting with a confined two-dimensional electron gas. The antiprotons follow a trajectory normal to jellium circular clusters of variable size, crossing every cluster at its geometrical center. Analysis of the characteristic time scales that define the process is made. For high-enough velocities, the interaction time between the projectile and the target electrons is shorter than the time needed for the density excitation to travel along the cluster. The finite-size object then behaves as an infinite system, and no quantum-size effects appear in the energy loss. For small velocities, the discretization of levels in the cluster plays a role and the energy loss does depend on the system size. A comparison to results obtained using linear theory of screening is made, and the relative contributions of electron-hole pair and plasmon excitations to the total energy loss are analyzed. This comparison also allows us to show the importance of a nonlinear treatment of the screening in the interaction process.

  14. Charging graphene for energy

    NASA Astrophysics Data System (ADS)

    Liu, Jun

    2014-10-01

    Energy storage is a grand challenge for future energy infrastructure, transportation and consumer electronics. Jun Liu discusses how graphene may -- or may not -- be used to improve various electrochemical energy storage devices.

  15. Method and apparatus for charged particle propagation

    DOEpatents

    Hershcovitch, Ady

    1996-11-26

    A method and apparatus are provided for propagating charged particles from a vacuum to a higher pressure region. A generator 14,14b includes an evacuated chamber 16a,b having a gun 18,18b for discharging a beam of charged particles such as an electron beam 12 or ion beam 12b. The beam 12,12b is discharged through a beam exit 22 in the chamber 16a,b into a higher pressure region 24. A plasma interface 34 is disposed at the beam exit 22 and includes a plasma channel 38 for bounding a plasma 40 maintainable between a cathode 42 and an anode 44 disposed at opposite ends thereof. The plasma channel 38 is coaxially aligned with the beam exit 22 for propagating the beam 12,12b from the chamber 16a,b, through the plasma 40, and into the higher pressure region 24. The plasma 40 is effective for pumping down the beam exit 22 for preventing pressure increase in the chamber 16a,b, and provides magnetic focusing of the beam 12,12b discharged into the higher pressure region 24.

  16. Spatiotemporal analysis of DNA repair using charged particle radiation.

    PubMed

    Tobias, F; Durante, M; Taucher-Scholz, G; Jakob, B

    2010-01-01

    Approaches to visualise the dynamics of the DNA lesion processing substantially contributes to the understanding of the hierarchical organisation of the DNA damage response pathways. Charged particle irradiation has recently emerged as a tool to generate discrete sites of subnuclear damage by its means of extremely localised dose deposition at low energies, thus facilitating the spatiotemporal analysis of repair events. In addition, they are of high interest for risk estimations of human space exploration (e.g. mars mission) in the high energy regime (HZE). In this short review we will give examples for the application of charged particle irradiation to study spatiotemporal aspects of DNA damage recognition and repair in the context of recent achievements in this field. Beamline microscopy allows determining the exact kinetics of repair-related proteins after irradiation with different charged particles that induce different lesion densities. The classification into fast recruited proteins like DNA-PK or XRCC1 or slower recruited ones like 53BP1 or MDC1 helps to establish the hierarchical organisation of damage recognition and subsequent repair events. Additionally, motional analysis of DNA lesions induced by traversing particles proved information about the mobility of DSBs. Increased mobility or the absence of large scale motion has direct consequences on the formation of chromosomal translocations and, thus, on mechanisms of cancer formation. Charged particle microbeams offer the interesting perspective of precise nuclear or subnuclear targeting with a defined number of ions, avoiding the Poisson distribution of traversals inherent to broad beam experiments. With the help of the microbeam, geometrical patterns of traversing ions can be applied facilitating the analysis of spatial organisation of repair. PMID:19944777

  17. A Search for Free Fractional Electric Charge Elementary Particles

    SciTech Connect

    Halyo, Valerie

    2000-12-04

    A direct search was carried out in bulk matter for free fractional electric charge elementary particles using the largest mass single sample ever studied--about 17.4 mg of silicone oil. The search used an improved and highly automated Millikan oil drop technique. No evidence for fractional charge particles was found. The concentration of particles with fractional charge more than 0.16 e (e being the magnitude of the electron charge) from the nearest integer charge is less than 4.71 x 10{sup -22} particles per nucleon with 95% confidence.

  18. A Search for Free Fractional Electric Charge Elementary Particles

    SciTech Connect

    Halyo, Valerie

    2000-12-04

    A direct search was carried out in bulk matter for free fractional electric charge elementary particles using the largest mass single sample ever studied| about 17.4 mg of silicone oil. The search used an improved and highly automated Millikan oil drop technique. No evidence for fractional charge particles was found. The concentration of particles with fractional charge more than 0.16 e (e being the magnitude of the electron charge) from the nearest integer charge is less than 4.71 x 10{sup -22} particles per nucleon with 95% confidence.

  19. Search for free fractional electric charge elementary particles

    SciTech Connect

    Halyo, V.

    1999-10-29

    The authors have carried out a direct search in bulk matter for free fractional electric charge elementary particles using the largest mass single sample ever studied--about 17.4 mg of silicone oil. The search used an improved and highly automated Millikan oil drop technique. No evidence for fractional charge particles was found. The concentration of particles with fractional charge more than 0.16 e (e being the magnitude of the electron charge) from the nearest integer charge is less than 4.71 x 10{sup {minus}22} particles per nucleon with 95% confidence.

  20. The response of thermally and optically stimulated luminescence from Al2O3:C to high-energy heavy charged particles

    NASA Technical Reports Server (NTRS)

    Gaza, R.; Yukihara, E. G.; McKeever, S. W. S.

    2004-01-01

    The thermoluminescence (TL) and optically stimulated luminescence (OSL) response of Al2O3 dosimeters to high-energy heavy charged particles (HCP) has been studied using the heavy ion medical accelerator at Chiba, Japan. The samples were Al2O3 single-crystal chips, of the type usually known as TLD-500, and Luxel(TM) dosimeters (Al2O3:C powder in plastic) from Landauer Inc. The samples were exposed to 4He (150 MeV/u), 12C (400 MeV/u), 28Si (490 MeV/us) and 56Fe (500 MeV/u) ions, with linear energy transfer values covering the range from 2.26 to 189 keV/micrometers in water and doses from 1 to 100 mGy (to water). A 90Sr/90Y beta source, calibrated against a 60Co secondary standard, was used for calibration purposes. For OSL, we used both continuous-wave OSL measurements (CW-OSL, using green light stimulation at 525 nm) and pulsed OSL measurements (POSL, using 532 nm stimulation from a Nd:YAG Q-switched laser). The efficiencies (eta HCP, gamma) of the different HCPs at producing OSL or TL were observed to depend not only upon the linear energy transfer (LET) of the HCP, but also upon the sample type (single crystal chip or Luxel(TM)) and the luminescence method used to define the signal--i.e. TL, CW-OSL initial intensity, CW-OSL total area, or POSL. Observed changes in shape of the decay curve lead to potential methods for extracting LET information of unknown radiation fields. A discussion of the results is given, including the potential use of OSL from Al2O3 in the areas of space radiation dosimetry and radiation oncology. c2004 Elsevier Ltd. All rights reserved.

  1. Transverse energy production and charged-particle multiplicity at midrapidity in various systems from sNN=7.7 to 200 GeV

    DOE PAGESBeta

    Adare, A.; Afanasiev, S.; Aidala, C.; Ajitanand, N. N.; Akiba, Y.; Akimoto, R.; Al-Bataineh, H.; Alexander, J.; Alfred, M.; Al-Jamel, A.; et al

    2016-02-03

    Measurements of midrapidity charged-particle multiplicity distributions, dNch/dη, and midrapidity transverse-energy distributions, dET/dη, are presented for a variety of collision systems and energies. Included are distributions for Au+Au collisions at √sNN=200, 130, 62.4, 39, 27, 19.6, 14.5, and 7.7 GeV, Cu+Cu collisions at √sNN=200 and 62.4 GeV, Cu+Au collisions at √sNN=200 GeV, U+U collisions at√sNN=193 GeV, d+Au collisions at √sNN=200 GeV, He3+Au collisions at √sNN=200 GeV, and p+p collisions at √sNN=200 GeV. We present centrality-dependent distributions at midrapidity in terms of the number of nucleon participants, Npart, and the number of constituent quark participants, Nqp. For all A+A collisions down tomore » √sNN=7.7 GeV, we observed that the midrapidity data are better described by scaling with Nqp than scaling with Npart. Finally, our estimates of the Bjorken energy density, εBJ, and the ratio of dET/dη to dNch/dη are presented, the latter of which is seen to be constant as a function of centrality for all systems.« less

  2. Fluctuation of charge on dust particles in a complex plasma

    SciTech Connect

    Sodha, M. S.; Mishra, S. K.; Misra, Shikha; Srivastava, Sweta

    2010-07-15

    This paper presents an analytical model for the evaluation of the fluctuation of the charge on the dust particles in a complex plasma. In contrast to earlier analyses, which ignored the effect of dust particles on density and temperature of electrons and ions, the present model takes into account the number and energy balance of electrons and ions. Three cases, viz., (i) no emission, (ii) thermionic emission, and (iii) photoelectric emission of electrons from the dust particles, have been considered. The results have been graphically illustrated for typical parameters. It is seen that the plasma parameters, and hence the fluctuations, are considerably affected by the consideration of number and energy balance of electrons and ions. A comparison of the results of the present analysis with those of earlier works has also been made.

  3. Cataract production in mice by heavy charged particles

    NASA Technical Reports Server (NTRS)

    Ainsworth, E. J.; Jose, U.; Yang, V. V.; Barker, M. E.

    1981-01-01

    The cataractogenic effects of heavy charged particles are evaluated in mice in relation to dose and ionization density. The relative biological effectiveness in relation to linear energy transfer for various particles is considered. Results indicated that low single doses (5 to 20 rad) of Fe 56 or Ar 40 particles are cataractogenic at 11 to 18 months after irradiation; onset and density of the opacification are dose related and cataract density (grade) at 9, 11, 13, and 16 months after irradiation shows partial linear energy transfer dependence. The severity of cataracts is reduced significantly when 417 rad of Co 60 gamma radiation is given in 24 weekly 17 rad fractions compared to giving this radiation as a single dose, but cataract severity is not reduced by fractionation of C12 doses over 24 weeks.

  4. The use of optically stimulated luminescence from AL2O3:C in the dosimetry of high-energy heavy charged particle fields.

    PubMed

    Gaza, R; Yukihara, E G; McKeever, S W S

    2006-01-01

    This paper presents two different approaches of quantifying the optically stimulated luminescence (OSL) response of Al(2)O(3):C to high-energy heavy charged particles (HCPs). The OSL efficiency of Al(2)O(3):C exposed to different HCPs is defined as the sensitivity of the material to HCPs normalised by the sensitivity to gamma. In this paper, we investigate the possibility of introducing a 'mean efficiency' eta(mean), which when used in conjunction with the total gamma dose D(gamma) measured for a mixed radiation exposure allows for the determination of the absorbed dose without the need to determine the individual contributions of different types of radiation to the OSL signal. We tested the hypothesis that information regarding the 'mean efficiency' eta(mean) is contained in the shape of the OSL decay curve, using several approaches in the analysis of the OSL data. This analysis was applied to various mixed field irradiations performed at the HIMAC facility, Chiba, Japan. The results of this analysis are discussed. PMID:16644985

  5. Relative optically stimulated luminescence and thermoluminescence efficiencies of Al{sub 2}O{sub 3}:C dosimeters to heavy charged particles with energies relevant to space and radiotherapy dosimetry

    SciTech Connect

    Sawakuchi, G. O.; Yukihara, E. G.; McKeever, S. W. S.; Benton, E. R.; Gaza, R.; Uchihori, Y.; Yasuda, N.; Kitamura, H.

    2008-12-15

    This article presents a comprehensive characterization of the thermoluminescence (TL) and optically stimulated luminescence (OSL) relative luminescence efficiencies of carbon-doped aluminum (Al{sub 2}O{sub 3}:C) for heavy charged particles (HCPs) with atomic numbers ranging from 1 (proton) to 54 (xenon) and energies ranging from 7 to 1000 MeV/u, and investigates the dependence of the Al{sub 2}O{sub 3}:C response on experimental conditions. Relative luminescence efficiency values are presented for 19 primary charge/energy combinations, plus 31 additional charge/energy combinations obtained by introducing absorbers in the primary beam. Our results show that for energies of hundreds of MeV/u the data can be described by a single curve of relative luminescence efficiency versus linear energy transfer (LET). This information is needed to compensate for the reduced OSL efficiency to high-LET particles in such applications as space dosimetry. For lower energies, the relative luminescence efficiency as function of LET cannot be described by a single curve; instead, it separates into different components corresponding to different particles. We also present data on the low-LET dose response of Al{sub 2}O{sub 3}:C, measured under the same experimental conditions in which the relative luminescence efficiencies to HCPs were obtained, providing information relevant to future theoretical investigations of HCP energy deposition and luminescence production in Al{sub 2}O{sub 3}:C.

  6. Production of carbon monoxide by charged particle deposition.

    NASA Technical Reports Server (NTRS)

    Green, A. E. S.; Sawada, T.; Edgar, B. C.; Uman, M. A.

    1973-01-01

    Recent studies of electron energy deposition in CO2 and CO based upon a large set of electron impact cross sections are utilized to estimate the telluric CO directly produced by various charged-particle deposition mechanisms. The mechanisms considered are (1) lightning, (2) cloud coronal discharges, (3) background radioactivity, (4) natural electrostatic discharges, (5) photoelectrons in the ionosphere, (6) auroral electrons, (7) auroral protons, (8) cosmic rays, and (9) solar wind. 'Ball park' estimates of the global CO production by each of these mechanisms are given. Apart from mechanisms 1, 2, and 5, all CO production mechanisms are estimated to be small compared to artificial sources. If, as appears to be the case, the hot oxygen atoms and ions and other atomic species immediately produced by these three charged-particle deposition mechanisms react rapidly with CO2 to produce CO, these mechanisms can readily lead to CO production levels in the multimegaton-per-year range.

  7. Apparatus for Suspension of Charged Particles and Droplets

    ERIC Educational Resources Information Center

    Berg, T. G. Owe

    1969-01-01

    Describes an apparatus designed to study the properties of charged particles suspended in an electric field. The apparatus consists of a suspension chamber, an optical system and power supplies and controls. Experiments conducted include determination of particle size, charge-to-mass ratio and particle collisions and exchange. (LC)

  8. Energy deposited by charged particles

    SciTech Connect

    Wilson, W.E.; Miller, J.H.; Toburen, L.H.

    1982-04-01

    To characterize the absorption of ionizing radiations in matter on a size scale of macro molecular dimensions (nanometers), a computer code MOCA13 was devised. This improved code provides a high degree of detail in positive ion track simulation based on vapor phase interaction cross sections. (GHT)

  9. Searches for Fractionally Charged Particles: What Should Be Done Next?

    SciTech Connect

    Perl, Martin L.; /SLAC

    2009-01-15

    Since the initial measurements of the electron charge a century ago, experimenters have faced the persistent question as to whether elementary particles exist that have charges that are fractional multiples of the electron charge. I concisely review the results of the last 50 years of searching for fractional charge particles with no confirmed positive results. I discuss the question of whether more searching is worthwhile?

  10. A particle accelerator employing transient space charge potentials

    DOEpatents

    Post, R.F.

    1988-02-25

    The invention provides an accelerator for ions and charged particles. The plasma is generated and confined in a magnetic mirror field. The electrons of the plasma are heated to high temperatures. A series of local coils are placed along the axis of the magnetic mirror field. As an ion or particle beam is directed along the axis in sequence the coils are rapidly pulsed creating a space charge to accelerate and focus the beam of ions or charged particles. 3 figs.

  11. Bipolar charging of dust particles under ultraviolet radiation

    SciTech Connect

    Filippov, A. V. Babichev, V. N.; Fortov, V. E.; Gavrikov, A. V.; Pal', A. F.; Petrov, O. F.; Starostin, A. N.; Sarkarov, N. E.

    2011-05-15

    The photoemission charging of dust particles under ultraviolet radiation from a xenon lamp has been investigated. The velocities of yttrium dust particles with a work function of 3.3 eV and their charges have been determined experimentally; the latter are about 400-500 and about 100 elementary charges per micron of radius for the positively and negatively charged fractions, respectively. The dust particle charging and the dust cloud evolution in a photoemission cell after exposure to an ultraviolet radiation source under the applied voltage have been simulated numerically. The photoemission charging of dust particles has been calculated on the basis of nonlocal and local charging models. Only unipolar particle charging is shown to take place in a system of polydisperse dust particles with the same photoemission efficiency. It has been established that bipolar charging is possible in the case of monodisperse particles with different quantum efficiencies. Polydispersity in this case facilitates the appearance of oppositely charged particles in a photoemission plasma.

  12. Determination of colloidal particle surface charge from dielectrophoresis

    NASA Astrophysics Data System (ADS)

    Chavez, Marko; Nuansri, Rittirong; Mazza, Jacob; Ou-Yang, H. Daniel

    2015-03-01

    Electrophoresis (EP) is used to determine colloidal particle surface charge. However, when the Debye length is comparable to or larger than the particle size, electrophoresis cannot be reliably used to determine the surface charge due to counter ion retardation flow. Alexander et al. developed a theory relating colloidal osmotic pressure and particle surface charge. We use dielectrophoresis (DEP) to obtain a potential landscape based on the number density distribution of the particles in a non-uniform AC electric field. We determine the osmotic pressure from the DEP force and density profiles using Einstein's osmotic equilibrium equation. Surface charge obtained by DEP (thermodynamics) will be compared to that obtained by EP (electrokinetics).

  13. Surface charge accumulation of particles containing radionuclides in open air

    DOE PAGESBeta

    Kim, Yong-ha; Yiacoumi, Sotira; Tsouris, Costas

    2015-05-01

    Radioactivity can induce charge accumulation on radioactive particles. But, electrostatic interactions caused by radioactivity are typically neglected in transport modeling of radioactive plumes because it is assumed that ionizing radiation leads to charge neutralization. The assumption that electrostatic interactions caused by radioactivity are negligible is evaluated here by examining charge accumulation and neutralization on particles containing radionuclides in open air. Moreover, a charge-balance model is employed to predict charge accumulation on radioactive particles. It is shown that particles containing short-lived radionuclides can be charged with multiple elementary charges through radioactive decay. The presence of radioactive particles can significantly modify themore » particle charge distribution in open air and yield an asymmetric bimodal charge distribution, suggesting that strong electrostatic particle interactions may occur during short- and long-range transport of radioactive particles. Possible effects of transported radioactive particles on electrical properties of the local atmosphere are reported. Our study offers insight into transport characteristics of airborne radionuclides. Results are useful in atmospheric transport modeling of radioactive plumes.« less

  14. Surface charge accumulation of particles containing radionuclides in open air

    SciTech Connect

    Kim, Yong-ha; Yiacoumi, Sotira; Tsouris, Costas

    2015-05-01

    Radioactivity can induce charge accumulation on radioactive particles. But, electrostatic interactions caused by radioactivity are typically neglected in transport modeling of radioactive plumes because it is assumed that ionizing radiation leads to charge neutralization. The assumption that electrostatic interactions caused by radioactivity are negligible is evaluated here by examining charge accumulation and neutralization on particles containing radionuclides in open air. Moreover, a charge-balance model is employed to predict charge accumulation on radioactive particles. It is shown that particles containing short-lived radionuclides can be charged with multiple elementary charges through radioactive decay. The presence of radioactive particles can significantly modify the particle charge distribution in open air and yield an asymmetric bimodal charge distribution, suggesting that strong electrostatic particle interactions may occur during short- and long-range transport of radioactive particles. Possible effects of transported radioactive particles on electrical properties of the local atmosphere are reported. Our study offers insight into transport characteristics of airborne radionuclides. Results are useful in atmospheric transport modeling of radioactive plumes.

  15. Surface charge accumulation of particles containing radionuclides in open air.

    PubMed

    Kim, Yong-ha; Yiacoumi, Sotira; Tsouris, Costas

    2015-05-01

    Radioactivity can induce charge accumulation on radioactive particles. However, electrostatic interactions caused by radioactivity are typically neglected in transport modeling of radioactive plumes because it is assumed that ionizing radiation leads to charge neutralization. The assumption that electrostatic interactions caused by radioactivity are negligible is evaluated here by examining charge accumulation and neutralization on particles containing radionuclides in open air. A charge-balance model is employed to predict charge accumulation on radioactive particles. It is shown that particles containing short-lived radionuclides can be charged with multiple elementary charges through radioactive decay. The presence of radioactive particles can significantly modify the particle charge distribution in open air and yield an asymmetric bimodal charge distribution, suggesting that strong electrostatic particle interactions may occur during short- and long-range transport of radioactive particles. Possible effects of transported radioactive particles on electrical properties of the local atmosphere are reported. The study offers insight into transport characteristics of airborne radionuclides. Results are useful in atmospheric transport modeling of radioactive plumes.

  16. Microsparks Generated by Charged Particles in Dielectric Liquids

    NASA Astrophysics Data System (ADS)

    Geiger, Robert

    2012-10-01

    The electrodynamics of charged particles in dielectric liquids have been described by several authors [1,2]. As a charged particle approaches an electrode of opposite charge the local electric field eventually exceeds the dielectric strength of the liquid and a microspark is generated. These plasmas can be very small, about < 5 μm, and may exhibit non-thermal behavior. Such non-thermal behavior can provide interesting and efficient chemical reactions [3]. An understanding of the plasma properties for this type of discharge can provide a simple means of generating non-thermal plasmas in dielectric liquids, such as oils or other hydrocarbons, which can be used to chemically process the liquids. Such a technology may lead to a highly efficient method of heavy oil upgrading which can be easily scaled. In order to understand the plasma properties optical emission spectroscopy is carried out for various hydrocarbons and voltage-current characteristics are used to determine the energy cost for this process. [4pt] [1] Melcher, James R. Continuum Electromechanics. Cambridge, MA: MIT Press, 1981.[0pt] [2] Jones, Thomas B. Electromechanics of Particles. Cambridge University Press 1995.[0pt] [3] Staack, D., Fridman, A., Gutsol, A., Gogotsi, Y. and Friedman, G. 2008, Angew. Chem., Int. Ed. 47, 8020.

  17. Accelerators for charged particle therapy: PAMELA and related issues

    NASA Astrophysics Data System (ADS)

    Peach, Ken

    2014-05-01

    Cancer is a dreadful disease that will affect one in three people at some point in their life; radiotherapy is used in more than half of all cancer treatment, and contributes about 40% to the successful treatment of cancer. Charged Particle Therapy uses protons and other light ions to deliver the lethal dose to the tumor while being relatively sparing of healthy tissue and, because of the finite range of the particles, is able to avoid giving any dose to vital organs. While there are adequate technologies currently available to deliver the required energies and fluxes, the two main technologies (cyclotrons and synchrotrons) have limitations. PAMELA (the Particle Accelerator for MEdicaLApplications) uses the newly-developed non-scaling Fixed Field Alternating Gradient accelerator concepts to deliver therapeutically relevant beams. The status of the development of the PAMELA conceptual design is discussed.

  18. Energization of charged particles in the Saturn's magnetosphere

    NASA Astrophysics Data System (ADS)

    Martínez-Gómez, E.; Durand-Manterola, H.; Pérez de Tejada, H.

    The acceleration of charged particles to suprathermal energies appears to occur in every diffuse plasma of astrophysical interest Mechanisms like the direct electrostatic acceleration the stochastic acceleration the diffusive shock acceleration the shock drift acceleration the resonant acceleration by MHD waves the resonant acceleration by Alfven and Langmuir waves the runaway acceleration the acceleration by potential double layers and the acceleration during magnetic reconnection are observed in a wide variety of astrophysical sites ranging from the terrestrial aurorae to the most distant quasars The simplest type of acceleration is the systematic acceleration in an electrostatic field parallel to the magnetic field Consequently one is lead to the concept of stochastic acceleration or second order Fermi acceleration The main idea is that the electric field is random in some sense and that although particles both gain and lose energy in elementary interactions they gain energy on average The essential requirements of a stochastic acceleration mechanism are 1 elementary interactions which cause the energy of the particles to change due to the betatron effect reflection of moving magnetic inhomogeneities or transit damping 2 effective scattering attributed to wave-particle interactions and 3 a random process statistical treatment usually based either on a Fokker-Planck approach or on a quasilinear approach implying that stochastic acceleration may be regarded as a diffusion in momentum space We propose a different

  19. Co-culturing with High-Charge and Energy Particle Irradiated Cells Increases Mutagenic Joining of Enzymatically Induced DNA Double-Strand Breaks in Nonirradiated Cells.

    PubMed

    Li, Zhentian; Doho, Gregory; Zheng, Xuan; Jella, Kishore Kumar; Li, Shuyi; Wang, Ya; Dynan, William S

    2015-09-01

    Cell populations that have been exposed to high-charge and energy (HZE) particle radiation, and then challenged by expression of a rare-cutting nuclease, show an increased frequency of deletions and translocations originating at the enzyme cut sites. Here, we examine whether this effect also occurs in nonirradiated cells that have been co-cultured with irradiated cells. Human cells were irradiated with 0.3-1.0 Gy of either 600 MeV/u (56)Fe or 1,000 MeV/u (48)Ti ions or with 0.3-3.0 Gy of 320 kV X rays. These were co-cultured with I-SceI-expressing reporter cells at intervals up to 21 days postirradiation. Co-culture with HZE-irradiated cells led to an increase in the frequency of I-SceI-stimulated translocations and deletions in the nonirradiated cells. The effect size was similar to that seen previously in directly irradiated populations (maximum effect in bystander cells of 1.7- to 4-fold depending on ion and end point). The effect was not observed when X-ray-irradiated cells were co-cultured with nonirradiated cells, but was correlated with an increase in γ-H2AX foci-positive cells in the nonirradiated population, suggesting the presence of genomic stress. Transcriptional profiling of a directly irradiated cell population showed that many genes for cytokines and other secretory proteins were persistently upregulated, but their induction was not well correlated with functional effects on repair in co-cultured cells, suggesting that this transcriptional response alone is not sufficient to evoke the effect. The finding that HZE-irradiated cells influence the DNA double-strand break repair fidelity in their nonirradiated neighbors has implications for risk in the space radiation environment.

  20. MASS SEPARATION OF HIGH ENERGY PARTICLES

    DOEpatents

    Marshall, L.

    1962-09-25

    An apparatus and method are described for separating charged, high energy particles of equal momentum forming a beam where the particles differ slightly in masses. Magnetic lenses are utilized to focus the beam and maintain that condition while electrostatic fields located between magnetic lenses are utilized to cause transverse separation of the particles into two beams separated by a sufficient amount to permit an aperture to block one beam. (AEC)

  1. Microscopic visualization of a biological response to charged particle traversal

    NASA Astrophysics Data System (ADS)

    Taucher-Scholz, G.; Jakob, B.; Becker, G.; Scholz, M.

    2003-08-01

    Understanding the molecular mechanisms underlying biological effects of charged particle radiation has become increasingly important in view of the use of ion beams in tumor therapy. Elucidating how the enhanced efficiency of densely ionizing radiation in cell killing is related to the initial causative lesions, namely DNA double-strand breaks, constitutes a major task in radiobiology. The inhomogeneous spatial distribution of energy deposition leading to the induction of more complex and less reparable DNA lesions is the basis for high-LET effects. But the cellular response to radiation damage also involves the interplay between repair and signal transduction proteins with the aim of coordinating the processing of DNA damage and cell cycle progression to allow time for repair. Charged particles are used as a probe for the production of localized subcellular damage to study these aspects of the biological response to ionizing radiation. Immunocytochemical techniques applied in combination with confocal laser microscopy allow to monitor the relocalization of DNA damage response proteins within individual nuclei following irradiation. In particular, the rapid accumulation of the signalling protein p21 at sites of heavy ion-induced DNA damage reflects the microscopic distribution of dose deposited within nuclei of irradiated human fibroblasts. The biological response pattern for p21 is presented for high and low energy ion beams, involving different particle species and representing a wide range of radiation qualities.

  2. GENERAL: Hawking Radiation of Charged Particles in Reissner-Nordström Black Hole

    NASA Astrophysics Data System (ADS)

    Zhao, Ren; Zhang, Li-Chun; Li, Huai-Fan

    2010-03-01

    We extend the method that Banerjee and Majhi have used to discuss Hawking radiation. Under the condition that the total energy and electrical charge of spacetime are conserved, we investigate Hawking radiation of the charged black hole by a new Tortoise coordinate transformation. Taking the reaction of the radiation of the particle to the spacetime into consideration, we not only derive the radiation spectrum that satisfies the unitary principle in quantum mechanics but also show that the contribution of ingoing particles is equal to the one of outgoing particles on the similar chemical potential term in radiation spectrum caused by charged particles.

  3. Ferroelectric Devices Emit Charged Particles and Radiation

    NASA Technical Reports Server (NTRS)

    Bar-Cohen, Yoseph; Sherrit, Stewart; Bao, Xiaoqi; Felsteiner, Joshua; Karsik, Yakov

    2005-01-01

    Devices called solid-state ferroelectric- based sources (SSFBSs) are under development as sources of electrons, ions, ultraviolet light, and x-rays for diverse applications in characterization and processing of materials. Whereas heretofore it has been necessary to use a different device to generate each of the aforementioned species of charged particles or radiation, a single SSFBS can be configured and operated to selectively generate any of the species as needed using a single source. Relative to comparable prior sources based, variously, on field emission, thermionic emission, and gaseous discharge plasmas, SSFBSs demand less power, and are compact and lightweight. An SSFBS exploits the unique physical characteristics of a ferroelectric material in the presence of a high-frequency pulsed electric field. The basic building block of an SSFBS is a ferroelectric cathode -- a ferroelectric wafer with a solid electrode covering its rear face and a grid electrode on its front face (see figure). The application of a voltage pulse -- typically having amplitude of several kilovolts and duration of several nanoseconds -- causes dense surface plasma to form near the grid wires on the front surface.

  4. Charging Graphene for Energy Storage

    SciTech Connect

    Liu, Jun

    2014-10-06

    Since 2004, graphene, including single atomic layer graphite sheet, and chemically derived graphene sheets, has captured the imagination of researchers for energy storage because of the extremely high surface area (2630 m2/g) compared to traditional activated carbon (typically below 1500 m2/g), excellent electrical conductivity, high mechanical strength, and potential for low cost manufacturing. These properties are very desirable for achieving high activity, high capacity and energy density, and fast charge and discharge. Chemically derived graphene sheets are prepared by oxidation and reduction of graphite1 and are more suitable for energy storage because they can be made in large quantities. They still contain multiply stacked graphene sheets, structural defects such as vacancies, and oxygen containing functional groups. In the literature they are also called reduced graphene oxide, or functionalized graphene sheets, but in this article they are all referred to as graphene for easy of discussion. Two important applications, batteries and electrochemical capacitors, have been widely investigated. In a battery material, the redox reaction occurs at a constant potential (voltage) and the energy is stored in the bulk. Therefore, the energy density is high (more than 100 Wh/kg), but it is difficult to rapidly charge or discharge (low power, less than 1 kW/kg)2. In an electrochemical capacitor (also called supercapacitors or ultracapacitor in the literature), the energy is stored as absorbed ionic species at the interface between the high surface area carbon and the electrolyte, and the potential is a continuous function of the state-of-charge. The charge and discharge can happen rapidly (high power, up to 10 kW/kg) but the energy density is low, less than 10 Wh/kg2. A device that can have both high energy and high power would be ideal.

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

    SciTech Connect

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

    2008-09-07

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

  6. Transcription Factors in the Cellular Response to Charged Particle Exposure.

    PubMed

    Hellweg, Christine E; Spitta, Luis F; Henschenmacher, Bernd; Diegeler, Sebastian; Baumstark-Khan, Christa

    2016-01-01

    Charged particles, such as carbon ions, bear the promise of a more effective cancer therapy. In human spaceflight, exposure to charged particles represents an important risk factor for chronic and late effects such as cancer. Biological effects elicited by charged particle exposure depend on their characteristics, e.g., on linear energy transfer (LET). For diverse outcomes (cell death, mutation, transformation, and cell-cycle arrest), an LET dependency of the effect size was observed. These outcomes result from activation of a complex network of signaling pathways in the DNA damage response, which result in cell-protective (DNA repair and cell-cycle arrest) or cell-destructive (cell death) reactions. Triggering of these pathways converges among others in the activation of transcription factors, such as p53, nuclear factor κB (NF-κB), activated protein 1 (AP-1), nuclear erythroid-derived 2-related factor 2 (Nrf2), and cAMP responsive element binding protein (CREB). Depending on dose, radiation quality, and tissue, p53 induces apoptosis or cell-cycle arrest. In low LET radiation therapy, p53 mutations are often associated with therapy resistance, while the outcome of carbon ion therapy seems to be independent of the tumor's p53 status. NF-κB is a central transcription factor in the immune system and exhibits pro-survival effects. Both p53 and NF-κB are activated after ionizing radiation exposure in an ataxia telangiectasia mutated (ATM)-dependent manner. The NF-κB activation was shown to strongly depend on charged particles' LET, with a maximal activation in the LET range of 90-300 keV/μm. AP-1 controls proliferation, senescence, differentiation, and apoptosis. Nrf2 can induce cellular antioxidant defense systems, CREB might also be involved in survival responses. The extent of activation of these transcription factors by charged particles and their interaction in the cellular radiation response greatly influences the destiny of the irradiated and also

  7. Determination of time zero from a charged particle detector

    DOEpatents

    Green, Jesse Andrew

    2011-03-15

    A method, system and computer program is used to determine a linear track having a good fit to a most likely or expected path of charged particle passing through a charged particle detector having a plurality of drift cells. Hit signals from the charged particle detector are associated with a particular charged particle track. An initial estimate of time zero is made from these hit signals and linear tracks are then fit to drift radii for each particular time-zero estimate. The linear track having the best fit is then searched and selected and errors in fit and tracking parameters computed. The use of large and expensive fast detectors needed to time zero in the charged particle detectors can be avoided by adopting this method and system.

  8. Acceleration of energetic charged particles: Shocks, reconnection or turbulence?

    NASA Astrophysics Data System (ADS)

    Jokipii, J. R.

    2012-05-01

    Acceleration of energetic charged charged particles, most-often with power-law energy spectra occurs everywhere is space where particle-particle collision mean free paths are significantly larger than their gyro-radii. Shocks, reconnection events and turbulence have variously been proposed as acceleration mechanisms, and each must currently be considered a viable mechanism. Shocks have the advantage that they produce naturally power-law spectra in the observed range which are not very sensitive to the parameters. They are usually also fast accelerators. I first discuss the constraints which observations place on the acceleration mechanisms and show that there are both temporal and spatial constraints. Stochastic acceleration tends to be slow, so the rate of acceleration is important. In the inner heliosphere, this rate must exceed the rate of adiabatic cooling ~ 2Vw/r, where Vw is the radial solar-wind velocity. Acceleration of anomalous cosmic rays (ACR) in the heliosheath must occur on a time scale of on year to avoid producing too many multiply charged ACR. It is shown that here, stochastic acceleration has difficulties in the inner heliosheath. Reconnection events are essentially incompressible, so the divergence of the flow velocity is nearly zero, and the Parker equation would give little acceleration. Acceleration at reconnection therefore must go beyond the Parker equation - either by invoking large pitch-angle anisotropies or by extending the equation to higher order in the flow speed relative to the particle speed. An approach to using an extension of Parker's equation is discussed. Diffusive shock acceleration at the heliospheric termination shock is also discussed. It is suggested that inclusion of upstream turbulence and shock geometry provides reasonable solutions to the perceived problems with this mechanism. Finally, observation evidence is presented which suggests, strongly, that the acceleration of the ACR occurs in the inner heliosphere, not far

  9. Energetic charged particles in the uranian magnetosphere.

    PubMed

    Stone, E C; Cooper, J F; Cummings, A C; McDonald, F B; Trainor, J H; Lal, N; McGuire, R; Chenette, D L

    1986-07-01

    During the encounter with Uranus, the cosmic ray system on Voyager 2 measured significant fluxes of energetic electrons and protons in the regions of the planets magnetosphere where these particles could be stably trapped. The radial distribution of electrons with energies of megaelectron volts is strongly modulated by the sweeping effects ofthe three major inner satellites Miranda, Ariel, and Umbriel. The phase space density gradient of these electrons indicates that they are diffusing radially inward from a source in the outer magnetosphere or magnetotail. Differences in the energy spectra of protons having energies of approximately 1 to 8 megaelectron volts from two different directions indicate a strong dependence on pitch angle. From the locations of the absorption signatures observed in the electron flux, a centered dipole model for the magnetic field of Uranus with a tilt of 60.1 degrees has been derived, and a rotation period of the planet of 17.4 hours has also been calculated. This model provides independent confirmaton of more precise determinations made by other Voyager experiments.

  10. Relativistic mixtures of charged and uncharged particles

    SciTech Connect

    Kremer, Gilberto M.

    2014-01-14

    Mixtures of relativistic gases within the framework of Boltzmann equation are analyzed. Three systems are considered. The first one refers to a mixture of uncharged particles by using Grad’s moment method, where the relativistic mixture is characterized by the moments of the distribution functions: particle four-flows, energy-momentum tensors, and third-order moment tensors. In the second Fick’s law for a mixture of relativistic gases of non-disparate rest masses in a Schwarzschild metric are derived from an extension of Marle and McCormack model equations applied to a relativistic truncated Grad’s distribution function, where it is shown the dependence of the diffusion coefficient on the gravitational potential. The third one consists in the derivation of the relativistic laws of Ohm and Fourier for a binary mixtures of electrons with protons and electrons with photons subjected to external electromagnetic fields and in presence of gravitational fields by using the Anderson and Witting model of the Boltzmann equation.

  11. Laboratory investigation of electric charging of dust particles by electrons, ions, and UV radiation

    NASA Technical Reports Server (NTRS)

    Svestka, Jiri; Pinter, S.; Gruen, E.

    1989-01-01

    In many cosmic environments electric charging of dust particles occurs by electrons, ions, and UV radiation. In case of interstellar dust particles the value of their electric charge can have, for instance, very important consequences for their destruction rate in supernova remnant's shock waves and can globally influence the overall life cycle of dust particles in galaxies. For experimental simulation of charging processes a vacuum chamber was used in which the particles fall through an electron or ion beam of energies up to 10 KeV. The aim of the experiments was to attain maximum charge of dust particles. Furthermore the influence of the rest gas was also determined because electrons and ions produced by collisional ionization of the rest gas can result in significant effects. For measurement particles from 1 to 100 microns from glass, carbon, Al, Fe, MgO, and very loosely bound conglomerates of Al2O3 were used.

  12. Calibration and Readiness of the ISS-RAD Charged Particle Detector

    NASA Technical Reports Server (NTRS)

    Rios, R.

    2015-01-01

    The International Space Station (ISS) Radiation Assessment Detector (RAD) is an intravehicular energetic particle detector designed to measure a broad spectrum of charged particle and neutron radiation unique to the ISS radiation environment. In this presentation, a summary of calibration and readiness of the RAD Sensor Head (RSH) - also referred to as the Charged Particle Detector (CPD) - for ISS will be presented. Calibration for the RSH consists of p, He, C, O, Si, and Fe ion data collected at the NASA Space Radiation Laboratory (NSRL) and Indiana University Cyclotron Facility (IUCF). The RSH consists of four detectors used in measuring the spectroscopy of charged particles - A, B, C, and D; high-energy neutral particles and charged particles are measured in E; and the last detector - F - is an anti-coincidence detector. A, B, and C are made from Si; D is made from BGO; E and F are made from EJ260XL plastic scintillator.

  13. Particle size effects in particle-particle triboelectric charging studied with an integrated fluidized bed and electrostatic separator system

    SciTech Connect

    Bilici, Mihai A.; Toth, Joseph R.; Sankaran, R. Mohan; Lacks, Daniel J.

    2014-10-15

    Fundamental studies of triboelectric charging of granular materials via particle-particle contact are challenging to control and interpret because of foreign material surfaces that are difficult to avoid during contacting and measurement. The measurement of particle charge itself can also induce charging, altering results. Here, we introduce a completely integrated fluidized bed and electrostatic separator system that charges particles solely by interparticle interactions and characterizes their charge on line. Particles are contacted in a free-surface fluidized bed (no reactor walls) with a well-controlled fountain-like flow to regulate particle-particle contact. The charged particles in the fountain are transferred by a pulsed jet of air to the top of a vertically-oriented electrostatic separator consisting of two electrodes at oppositely biased high voltage. The free-falling particles migrate towards the electrodes of opposite charge and are collected by an array of cups where their charge and size can be determined. We carried out experiments on a bidisperse size mixture of soda lime glass particles with systematically varying ratios of concentration. Results show that larger particles fall close to the negative electrode and smaller particles fall close to the positive electrode, consistent with theory and prior experiments that larger particles charge positively and smaller particles charge negatively. The segregation of particles by charge for one of the size components is strongest when its collisions are mostly with particles of the other size component; thus, small particles segregate most strongly to the negative sample when their concentration in the mixture is small (and analogous results occur for the large particles). Furthermore, we find additional size segregation due to granular flow, whereby the fountain becomes enriched in larger particles as the smaller particles are preferentially expelled from the fountain.

  14. [Galactic heavy charged particles damaging effect on biological structures].

    PubMed

    Grigor'ev, A I; Krasavin, E A; Ostrovskiĭ, M A

    2013-03-01

    A concept of the radiation risk of the manned interplanetary flights is proposed and substantiated. Heavy charged particles that are a component of the galactic cosmic rays (GCR) have a high damaging effect on the biological structures as great amount of energy is deposited in heavy particle tracks. The high biological effectiveness of heavy ions is observed in their action on cell genetic structures and the whole organism, including the brain structures. The hippocampus is the part of the central nervous system that is the most sensitive to radiation--first of all, to heavy charged particles. Irradiation of animals with accelerated iron ions at doses corresponding to the real fluxes of GCR heavy nuclei, to which Mars mission crews can be exposed, leads to marked behavioral function disorders in the post-irradiation period. To evaluate the radiation risk for the interplanetary flight crews, the concept of successful mission accomplishment is introduced. In these conditions, the central nervous system structures can be the critical target of GCR heavy nuclei. Their damage can modify the higher integrative functions of the brain and cause disorders in the crew members' operator performances.

  15. [Galactic heavy charged particles damaging effect on biological structures].

    PubMed

    Grigor'ev, A I; Krasavin, E A; Ostrovskiĭ, M A

    2013-03-01

    A concept of the radiation risk of the manned interplanetary flights is proposed and substantiated. Heavy charged particles that are a component of the galactic cosmic rays (GCR) have a high damaging effect on the biological structures as great amount of energy is deposited in heavy particle tracks. The high biological effectiveness of heavy ions is observed in their action on cell genetic structures and the whole organism, including the brain structures. The hippocampus is the part of the central nervous system that is the most sensitive to radiation--first of all, to heavy charged particles. Irradiation of animals with accelerated iron ions at doses corresponding to the real fluxes of GCR heavy nuclei, to which Mars mission crews can be exposed, leads to marked behavioral function disorders in the post-irradiation period. To evaluate the radiation risk for the interplanetary flight crews, the concept of successful mission accomplishment is introduced. In these conditions, the central nervous system structures can be the critical target of GCR heavy nuclei. Their damage can modify the higher integrative functions of the brain and cause disorders in the crew members' operator performances. PMID:23789432

  16. Response of thermoluminescent detectors to charged particles and to neutrons.

    PubMed

    Spurný, Frantisek

    2004-01-01

    Thermoluminescent detectors (TLDs) are widely used for the dosimetry of photons and electrons. They are less used for the radiation with higher linear energy transfer (LET). One of the reasons for that is that their TL relative efficiency eta decreases for the most of them with increasing LET. The paper presents first a review of author's experimental results in which eta was established for charged particles having LET of the order from 1 to 100 keV/micrometers in tissue. Among TLDs studied were known materials like LiF:Mn; Ti; Al-P glass; CaSO4:Dy; Al2O3:Na; and Al2O3:C. It was found that the dependence of their eta on LET is not the same for all TLDs studied. The response of the same materials to neutrons was also studied. It was found that both eta as the relative response (RR) defined in terms of absorbed dose in tissue are different, they depend critically also on the composition. When a TLD contains nuclei like 6Li and 10B, their RR would be rather high. As far as eta is concerned, the same tendencies were observed as for charged particles, i.e. when average LET of secondary particles formed in a TLD increases, their eta generally decreases. PMID:15856571

  17. Charged particle therapy--optimization, challenges and future directions.

    PubMed

    Loeffler, Jay S; Durante, Marco

    2013-07-01

    The use of charged particle therapy to control tumours non-invasively offers advantages over conventional radiotherapy. Protons and heavy ions deposit energy far more selectively than X-rays, allowing a higher local control of the tumour, a lower probability of damage to healthy tissue, low risk of complications and the chance for a rapid recovery after therapy. Charged particles are also useful for treating tumours located in areas that surround tissues that are radiosensitive and in anatomical sites where surgical access is limited. Current trial outcomes indicate that accelerated ions can potentially replace surgery for radical cancer treatments, which might be beneficial as the success of surgical cancer treatments are largely dependent on the expertise and experience of the surgeon and the location of the tumour. However, to date, only a small number of controlled randomized clinical trials have made comparisons between particle therapy and X-rays. Therefore, although the potential advantages are clear and supported by data, the cost:benefit ratio remains controversial. Research in medical physics and radiobiology is focusing on reducing the costs and increasing the benefits of this treatment.

  18. Charged particle LET-spectra measurements aboard LDEF

    NASA Technical Reports Server (NTRS)

    Csige, I.; Benton, E. V.; Frank, A. L.; Frigo, L. A.; Benton, E. R.; Parnell, T. A.; Watts, John W., Jr.

    1991-01-01

    The linear energy transfer (LET) spectra of charged particles was measured in the 5 to 250 keV/micron (water) interval with CR-39 and in the 250 to 1000 keV/micron (water) interval with polycarbonate plastic nuclear track detectors (PNTDs) under different shielding depths in the P0006 experiment. The optimal processing conditions were determined for both PNTDs in relation to the relatively high track densities due to the long term exposure in space. The total track density was measured over the selected samples, and tracks in coincidence on the facing surfaces of two detector sheets were selected for measuring at the same position on each sheet. The Short Range (SR) and Galactic Cosmic Ray (GCR) components were measured separately. The integral dose and dose rate spectra of charged particles are also given. The high LET portion of the LET spectra was measured with high statistical accuracy. This is a unique result of this experiment due to the low flux of this type of particle under typical shielding conditions.

  19. Search for new charged massive stable particles at CDF

    NASA Astrophysics Data System (ADS)

    CDF Collaboration

    1996-05-01

    We report on a general search at CDF for new particles which are electrically charged and sufficiently long-lived to allow detection (γ c τ >= 1m). Examples of such particles include free quarks, 4th generation leptons which are lighter than their neutrino, and sextet quarks. Their signature would be particles with high momentum but relatively low velocity, β <= 0.7, which would result in large ionization energy losses (dE/dx). Having observed no evidence for the production of new particles of this type, we set 95% confidence limits on their possible masses. *We thank the Fermilab staff and the technical staffs of the participating institutions for their vital contributions. This work was supported by the U.S. Department of Energy and National Science Foundation; the Italian Istituto Nazionale di Fisica Nucleare; the Ministry of Education, Science and Culture of Japan; the Natural Sciences and Engineering Research Council of Canada; the National Science Council of the Republic of China; and the A. P. Sloan Foundation. Supported by U.S. DOE under Contract No. DE-AC02-76CH03000.

  20. Search for Charged Massive Long-Lived Particles

    SciTech Connect

    Abazov V. M.; Abbott B.; Acharya B. S.; Adams M.; Adams T.; Alexeev G. D.; Alimena J.; Alkhazov G.; Alton A.; Alverson G.; Alves G. A.; Aoki M.; Askew A.; Asman B.; Atkins S.; Atramentov O.; Augsten K.; Avila C.; BackusMayes J.; Badaud F.; Bagby L.; Baldin B.; Bandurin D. V.; Banerjee S.; Barberis E.; Baringer P.; Barreto J.; Bartlett J. F.; Bassler U.; Bazterra V.; Bean A.; Begalli M.; Belanger-Champagne C.; Bellantoni L.; Beri S. B.; Bernardi G.; Bernhard R.; Bertram I.; Besancon M.; Beuselinck R.; Bezzubov V. A.; Bhat P. C.; Bhatnagar V.; Blazey G.; Blessing S.; Bloom K.; Boehnlein A.; Boline D.; Boos E. E.; Borissov G.; Bose T.; Brandt A.; Brandt O.; Brock R.; Brooijmans G.; Bross A.; Brown D.; Brown J.; Bu X. B.; Buehler M.; Buescher V.; Bunichev V.; Burdin S.; Burnett T. H.; Buszello C. P.; Calpas B.; Camacho-Perez E.; Carrasco-Lizarraga M. A.; Casey B. C. K.; Castilla-Valdez H.; Chakrabarti S.; Chakraborty D.; Chan K. M.; Chandra A.; Chapon E.; Chen G.; Chevalier-Thery S.; Cho D. K.; Cho S. W.; Choi S.; Choudhary B.; Cihangir S.; Claes D.; Clutter J.; Cooke M.; Cooper W. E.; Corcoran M.; Couderc F.; Cousinou M. -C.; Croc A.; Cutts D.; Das A.; Davies G.; De K.; de Jong S. J.; De la Cruz-Burelo E.; Deliot F.; Demina R.; Denisov D.; Denisov S. P.; Desai S.; Deterre C.; DeVaughan K.; Diehl H. T.; Diesburg M.; Ding P. F.; Dominguez A.; Dorland T.; Dubey A.; Dudko L. V.; Duggan D.; Duperrin A.; Dutt S.; Dyshkant A.; Eads M.; Edmunds D.; Ellison J.; Elvira V. D.; Enari Y.; Evans H.; Evdokimov A.; Evdokimov V. N.; Facini G.; Ferbel T.; Fiedler F.; Filthaut F.; Fisher W.; Fisk H. E.; Fortner M.; Fox H.; Fuess S.; Garcia-Bellido A.; Garcia-Guerra G. A.; Gavrilov V.; Gay P.; Geng W.; Gerbaudo D.; Gerber C. E.; Gershtein Y.; Ginther G.; Golovanov G.; Goussiou A.; Grannis P. D.; Greder S.; Greenlee H.; Greenwood Z. D.; Gregores E. M.; Grenier G.; Gris Ph.; Grivaz J. -F.; Grohsjean A.; Gruenendahl S.; Gruenewald M. W.; Guillemin T.; Gutierrez G.; Gutierrez P.; Haas A.; Hagopian S.; Haley J.; Han L.; Harder K.; Harel A.; Hauptman J. M.; Hays J.; Head T.; Hebbeker T.; Hedin D.; Hegab H.; Heinson A. P.; Heintz U.; Hensel C.; Heredia-De La Cruz I.; Herner K.; Hesketh G.; Hildreth M. D.; Hirosky R.; Hoang T.; Hobbs J. D.; Hoeneisen B.; Hohlfeld M.; Hubacek Z.; Hynek V.; Iashvili I.; Ilchenko Y.; Illingworth R.; Ito A. S.; Jabeen S.; Jaffre M.; Jamin D.; Jayasinghe A.; Jesik R.; Johns K.; Johnson M.; Jonckheere A.; Jonsson P.; Joshi J.; Jung A. W.; Juste A.; Kaadze K.; Kajfasz E.; Karmanov D.; Kasper P. A.; Katsanos I.; Kehoe R.; Kermiche S.; Khalatyan N.; Khanov A.; Kharchilava A.; Kharzheev Y. N.; Kohli J. M.; Kozelov A. V.; Kraus J.; Kulikov S.; Kumar A.; Kupco A.; Kurca T.; Kuzmin V. A.; Kvita J.; Lammers S.; Landsberg G.; Lebrun P.; Lee H. S.; Lee S. W.; Lee W. M.; Lellouch J.; Li L.; Li Q. Z.; Lietti S. M.; Lim J. K.; Lincoln D.; Linnemann J.; Lipaev V. V.; Lipton R.; Liu Y.; Lobodenko A.; Lokajicek M.; de Sa R. Lopes; Lubatti H. J.; Luna-Garcia R.; Lyon A. L.; Maciel A. K. A.; Mackin D.; Madar R.; Magana-Villalba R.; Malik S.; Malyshev V. L.; Maravin Y.; Martinez-Ortega J.; McCarthy R.; McGivern C. L.; Meijer M. M.; et al.

    2012-03-21

    We report on a search for charged massive long-lived particles (CMLLPs), based on 5.2 fb{sup -1} of integrated luminosity collected with the D0 detector at the Fermilab Tevatron p{bar p} collider. We search for events in which one or more particles are reconstructed as muons but have speed and ionization energy loss (dE/dx) inconsistent with muons produced in beam collisions. CMLLPs are predicted in several theories of physics beyond the standard model. We exclude pair-produced long-lived gaugino-like charginos below 267 GeV and Higgsino-like charginos below 217 GeV at 95% C.L., as well as long-lived scalar top quarks with mass below 285 GeV.

  1. Transcription Factors in the Cellular Response to Charged Particle Exposure

    PubMed Central

    Hellweg, Christine E.; Spitta, Luis F.; Henschenmacher, Bernd; Diegeler, Sebastian; Baumstark-Khan, Christa

    2016-01-01

    Charged particles, such as carbon ions, bear the promise of a more effective cancer therapy. In human spaceflight, exposure to charged particles represents an important risk factor for chronic and late effects such as cancer. Biological effects elicited by charged particle exposure depend on their characteristics, e.g., on linear energy transfer (LET). For diverse outcomes (cell death, mutation, transformation, and cell-cycle arrest), an LET dependency of the effect size was observed. These outcomes result from activation of a complex network of signaling pathways in the DNA damage response, which result in cell-protective (DNA repair and cell-cycle arrest) or cell-destructive (cell death) reactions. Triggering of these pathways converges among others in the activation of transcription factors, such as p53, nuclear factor κB (NF-κB), activated protein 1 (AP-1), nuclear erythroid-derived 2-related factor 2 (Nrf2), and cAMP responsive element binding protein (CREB). Depending on dose, radiation quality, and tissue, p53 induces apoptosis or cell-cycle arrest. In low LET radiation therapy, p53 mutations are often associated with therapy resistance, while the outcome of carbon ion therapy seems to be independent of the tumor’s p53 status. NF-κB is a central transcription factor in the immune system and exhibits pro-survival effects. Both p53 and NF-κB are activated after ionizing radiation exposure in an ataxia telangiectasia mutated (ATM)-dependent manner. The NF-κB activation was shown to strongly depend on charged particles’ LET, with a maximal activation in the LET range of 90–300 keV/μm. AP-1 controls proliferation, senescence, differentiation, and apoptosis. Nrf2 can induce cellular antioxidant defense systems, CREB might also be involved in survival responses. The extent of activation of these transcription factors by charged particles and their interaction in the cellular radiation response greatly influences the destiny of the irradiated and also

  2. Energy spectrum and chemical composition of cosmic rays between 0.3 and 10 PeV determined from the cherenkov-light and charged-particle distributions in air showers

    NASA Astrophysics Data System (ADS)

    HEGRA-Collaboration; Arqueros, F.; Barrio, J. A.; Bernlöhr, K.; Bojahr, H.; Calle, I.; Contreras, J. L.; Cortina, J.; Deckers, T.; Denninghoff, S.; Fonseca, V.; Gebauer, J.; González, J. C.; Haustein, V.; Heinzelmann, G.; Hohl, H.; Horns, D.; Ibarra, A.; Kestel, M.; Kirstein, O.; Kornmayer, H.; Kranich, D.; Krawczynski, H.; Lindner, A.; Lorenz, E.; Magnussen, N.; Meyer, H.; Mirzoyan, R.; Moralejo, A.; Padilla, L.; Petry, D.; Plaga, R.; Prahl, J.; Rauterberg, G.; Rhode, W.; Röhring, A.; Samorski, M.; Schmele, D.; Schröder, F.; Stamm, W.; Wiebel-Sooth, B.; Willmer, M.; Wittek, W.

    2000-07-01

    Measurements of the lateral distribution of Cherenkov photons with the wide-angle atmospheric Cherenkov light detector array AIROBICC and of the charged particle lateral distribution with the scintillator matrix of the HEGRA air-shower detector complex in air showers are reported. They are used in conjunction to determine the energy spectrum and coarse chemical composition of charged cosmic rays in the energy interval from 0.3 PeV to 10 PeV. With the atmospheric shower-front sampling technique these detectors measure the electromagnetic component of an extensive air shower via the lateral density distribution of the shower particles and of the Cherenkov photons. The data are compared with events generated with the CORSIKA program package with the QGSJET hadronic-event generator. Consistency checks performed with primary energy-reconstruction methods based on different shower observables indicate satisfactory agreement between these extensive air shower simulations and the experimental data. This permits to derive results concerning the energy spectrum and composition of charged cosmic rays. The energy spectrum features a so called ``knee'' at an energy of E_knee=3.98+4.66-0.83 (stat) +/- 0.53 (syst) PeV. Power law fits to the differential energy spectrum yield indices of -2.72+0.02-0.03 (stat) +/- 0.07 (syst) below and -3.22+0.47-0.59 (stat) +/- 0.08 (syst) above the knee. The best-fit elongation rate for the whole energy range is determined to 78.3 +/- 1.0 (stat) +/- 6.2 (syst) g/cm2. At the highest energies it seems to decrease slightly. The best-fit fraction of light nuclei decreases from 37 +28-21% (combined statistical and systematic) to 8 +32-8% (combined statistical and systematic) \\ in the energy range discussed here. A detailed study of the systematic errors reveals that a non-changing composition cannot be excluded.

  3. Charged particle multiplicities in ultra-relativistic Au+Au and Cu+Cu collisions.

    SciTech Connect

    Alver, B.; Back, B. B.; Baker, M. D.; Ballintijn, M.; Barton, D. S.; PHOBOS Collaboration; Physics; Massachusetts Inst. of Tech.; BNL

    2006-01-01

    The PHOBOS collaboration has carried out a systematic study of charged particle multiplicities in Cu+Cu and Au+Au collisions at the Relativistic Heavy-Ion Collider (RHIC) at Brookhaven National Laboratory. A unique feature of the PHOBOS detector is its ability to measure charged particles over a very wide angular range from 0.5 to 179.5 deg. corresponding to |eta|<5.4. The general features of the charged particle multiplicity distributions as a function of pseudo-rapidity, collision energy and centrality, as well as system size, are discussed.

  4. Screening of a charged dust particle within a nonlocal charging theory

    SciTech Connect

    Derbenev, I. N.; Filippov, A. V.

    2013-03-15

    We study the influence of the nonlocality of the electron energy distribution function on the dust particle charge screening in a two-component plasma of various inert gases and nitrogen at atmospheric pressure. For our analytical and numerical calculations, we have chosen the point sink model in the diffusion-drift approximation, which, in addition to the bulk production and loss of electrons and ions, also includes the heterogeneous processes of their absorption by a dust particle. We have established that the dust particle potential distribution in the problem under consideration is a superposition of three Debye exponentials with three different screening constants. The first constant practically coincides with the inverse Debye length. The second constant is determined by the inverse length travelled by the electrons and ions in the ambipolar diffusion process in the characteristic recombination time. The third constant coincides with the inverse characteristic distance of electron energy transfer through heat conduction in the characteristic time of electron energy establishment in the processes of heating by a beam of fast electrons and energy losses in elastic and inelastic collisions. We compare our numerical calculations of the screening constants with the analytical estimates obtained in the ambipolar diffusion approximation.

  5. Heavy charged particle radiobiology: using enhanced biological effectiveness and improved beam focusing to advance cancer therapy.

    PubMed

    Allen, Christopher; Borak, Thomas B; Tsujii, Hirohiko; Nickoloff, Jac A

    2011-06-01

    Ionizing radiation causes many types of DNA damage, including base damage and single- and double-strand breaks. Photons, including X-rays and γ-rays, are the most widely used type of ionizing radiation in radiobiology experiments, and in radiation cancer therapy. Charged particles, including protons and carbon ions, are seeing increased use as an alternative therapeutic modality. Although the facilities needed to produce high energy charged particle beams are more costly than photon facilities, particle therapy has shown improved cancer survival rates, reflecting more highly focused dose distributions and more severe DNA damage to tumor cells. Despite early successes of charged particle radiotherapy, there is room for further improvement, and much remains to be learned about normal and cancer cell responses to charged particle radiation.

  6. Heavy Charged Particle Radiobiology: Using Enhanced Biological Effectiveness and Improved Beam Focusing to Advance Cancer Therapy

    PubMed Central

    Allen, Christopher; Borak, Thomas B.; Tsujii, Hirohiko; Nickoloff, Jac A.

    2011-01-01

    Ionizing radiation causes many types of DNA damage, including base damage and single- and double-strand breaks. Photons, including X-rays and γ-rays, are the most widely used type of ionizing radiation in radiobiology experiments, and in radiation cancer therapy. Charged particles, including protons and carbon ions, are seeing increased use as an alternative therapeutic modality. Although the facilities needed to produce high energy charged particle beams are more costly than photon facilities, particle therapy has shown improved cancer survival rates, reflecting more highly focused dose distributions and more severe DNA damage to tumor cells. Despite early successes of charged particle radiotherapy, there is room for further improvement, and much remains to be learned about normal and cancer cell responses to charged particle radiation. PMID:21376738

  7. Heavy charged particle radiobiology: using enhanced biological effectiveness and improved beam focusing to advance cancer therapy.

    PubMed

    Allen, Christopher; Borak, Thomas B; Tsujii, Hirohiko; Nickoloff, Jac A

    2011-06-01

    Ionizing radiation causes many types of DNA damage, including base damage and single- and double-strand breaks. Photons, including X-rays and γ-rays, are the most widely used type of ionizing radiation in radiobiology experiments, and in radiation cancer therapy. Charged particles, including protons and carbon ions, are seeing increased use as an alternative therapeutic modality. Although the facilities needed to produce high energy charged particle beams are more costly than photon facilities, particle therapy has shown improved cancer survival rates, reflecting more highly focused dose distributions and more severe DNA damage to tumor cells. Despite early successes of charged particle radiotherapy, there is room for further improvement, and much remains to be learned about normal and cancer cell responses to charged particle radiation. PMID:21376738

  8. Energetic charged particle beams for disablement of mines

    SciTech Connect

    Wuest, C.R.

    1995-03-27

    LLNL has an ongoing program of weapons disablement using energetic charged particle beams; this program combines theoretical and experimental expertise in accelerators, high-energy and nuclear physics, plasma physics and hydrodynamics to simulate/measure effects of electron and proton beams on weapons. This paper reviews work by LLNL, LANL and NSWC on detonating sensitive and insensitive high explosives and land mines using high-current electron beams. Computer simulations are given. 20--160 MeV electron beams incident on wet/dry soils are being studied, along with electron beam propagation in air. Compact high current, high energy accelerators are being developed for mine clearing. Countermine missions of interest are discussed. 25 refs., 9 figs.

  9. Charging of multiple interacting particles by contact electrification.

    PubMed

    Soh, Siowling; Liu, Helena; Cademartiri, Rebecca; Yoon, Hyo Jae; Whitesides, George M

    2014-09-24

    Many processes involve the movement of a disordered collection of small particles (e.g., powders, grain, dust, and granular foods). These particles move chaotically, interact randomly among themselves, and gain electrical charge by contact electrification. Understanding the mechanisms of contact electrification of multiple interacting particles has been challenging, in part due to the complex movement and interactions of the particles. To examine the processes contributing to contact electrification at the level of single particles, a system was constructed in which an array of millimeter-sized polymeric beads of different materials were agitated on a dish. The dish was filled almost completely with beads, such that beads did not exchange positions. At the same time, during agitation, there was sufficient space for collisions with neighboring beads. The charge of the beads was measured individually after agitation. Results of systematic variations in the organization and composition of the interacting beads showed that three mechanisms determined the steady-state charge of the beads: (i) contact electrification (charging of beads of different materials), (ii) contact de-electrification (discharging of beads of the same charge polarity to the atmosphere), and (iii) a long-range influence across beads not in contact with one another (occurring, plausibly, by diffusion of charge from a bead with a higher charge to a bead with a lower charge of the same polarity).

  10. Search for Fractional-Charge Particles in Meteoritic Material

    NASA Astrophysics Data System (ADS)

    Kim, Peter C.; Lee, Eric R.; Lee, Irwin T.; Perl, Martin L.; Halyo, Valerie; Loomba, Dinesh

    2007-10-01

    We have used an automated Millikan oil drop method to search for free fractional-charge particles in a sample containing in total 3.9 mg of pulverized Allende meteorite suspended in 259 mg of mineral oil. The average diameter of the drops was 26.5μm with the charge on about 42 500 000 drops being measured. This search was motivated by the speculation that isolatable, fractional-charge particles produced in the early Universe and present in our Solar System are more likely to be accumulated in asteroids than on Earth‘s surface. No evidence for fractional-charge particles was found. With 95% confidence, the concentration of particles with fractional-charge more than 0.25 e (e being the magnitude of the electron charge) from the nearest integer charge is less than 1.3×10-21 particles per nucleon in the meteoritic material and less than 1.9×10-23 particles per nucleon in the mineral oil.

  11. Search for Fractional-Charge Particles in Meteoritic Material

    SciTech Connect

    Kim, Peter C.; Lee, Eric R.; Lee, Irwin T.; Perl, Martin L.; Halyo, Valerie; Loomba, Dinesh

    2007-10-19

    We have used an automated Millikan oil drop method to search for free fractional-charge particles in a sample containing in total 3.9 mg of pulverized Allende meteorite suspended in 259 mg of mineral oil. The average diameter of the drops was 26.5 {mu}m with the charge on about 42 500 000 drops being measured. This search was motivated by the speculation that isolatable, fractional-charge particles produced in the early Universe and present in our Solar System are more likely to be accumulated in asteroids than on Earth's surface. No evidence for fractional-charge particles was found. With 95% confidence, the concentration of particles with fractional-charge more than 0.25 e (e being the magnitude of the electron charge) from the nearest integer charge is less than 1.3x10{sup -21} particles per nucleon in the meteoritic material and less than 1.9x10{sup -23} particles per nucleon in the mineral oil.

  12. Search for fractional-charge particles in meteoritic material.

    PubMed

    Kim, Peter C; Lee, Eric R; Lee, Irwin T; Perl, Martin L; Halyo, Valerie; Loomba, Dinesh

    2007-10-19

    We have used an automated Millikan oil drop method to search for free fractional-charge particles in a sample containing in total 3.9 mg of pulverized Allende meteorite suspended in 259 mg of mineral oil. The average diameter of the drops was 26.5 microm with the charge on about 42 500 000 drops being measured. This search was motivated by the speculation that isolatable, fractional-charge particles produced in the early Universe and present in our Solar System are more likely to be accumulated in asteroids than on Earth's surface. No evidence for fractional-charge particles was found. With 95% confidence, the concentration of particles with fractional-charge more than 0.25 e (e being the magnitude of the electron charge) from the nearest integer charge is less than 1.3 x 10(-21) particles per nucleon in the meteoritic material and less than 1.9 x 10(-23) particles per nucleon in the mineral oil.

  13. Mechanisms of Particle Charging by Surfactants in Nonpolar Dispersions.

    PubMed

    Lee, Joohyung; Zhou, Zhang-Lin; Alas, Guillermo; Behrens, Sven Holger

    2015-11-10

    Electric charging of colloidal particles in nonpolar solvents plays a crucial role for many industrial applications and products, including rubbers, engine oils, toners, or electronic displays. Although disfavored by the low solvent permittivity, particle charging can be induced by added surfactants, even nonionic ones, but the underlying mechanism is poorly understood, and neither the magnitude nor the sign of charge can generally be predicted from the particle and surfactant properties. The conclusiveness of scientific studies has been limited partly by a traditional focus on few surfactant types with many differences in their chemical structure and often poorly defined composition. Here we investigate the surface charging of poly(methyl methacrylate) particles dispersed in hexane-based solutions of three purified polyisobutylene succinimide polyamine surfactants with "subtle" structural variations. We precisely vary the surfactant chemistry by replacing only a single electronegative atom located at a fixed position within the polar headgroup. Electrophoresis reveals that these small differences between the surfactants lead to qualitatively different particle charging. In the respective particle-free surfactant solutions we also find potentially telling differences in the size of the surfactant aggregates (inverse micelles), the residual water content, and the electric solution conductivity as well as indications for a significant size difference between oppositely charged inverse micelles of the most hygroscopic surfactant. An analysis that accounts for the acid/base properties of all constituents suggests that the observed particle charging is better described by asymmetric adsorption of charged inverse micelles from the liquid bulk than by charge creation at the particle surface. Intramicellar acid-base interaction and intermicellar surfactant exchange help rationalize the formation of micellar ions pairs with size asymmetry. PMID:26484617

  14. Maximizing ion current by space-charge neutralization using negative ions and dust particles

    SciTech Connect

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

    2005-05-15

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

  15. Accelerators for heavy-charged-particle radiation therapy.

    PubMed

    Coutrakon, George B

    2007-08-01

    This paper focuses on current and future designs of medical hadron accelerators for treating cancers and other diseases. Presently, five vendors and several national laboratories have produced heavy-particle medical accelerators for accelerating nuclei from hydrogen (protons) up through carbon and oxygen. Particle energies are varied to control the beam penetration depth in the patient. As of the end of 2006, four hospitals and one clinic in the United States offer proton treatments; there are five more such facilities in Japan. In most cases, these facilities use accelerators designed explicitly for cancer treatments. The accelerator types are a combination of synchrotrons, cyclotrons, and linear accelerators; some carry advanced features such as respiration gating, intensity modulation, and rapid energy changes, which contribute to better dose conformity on the tumor when using heavy charged particles. Recent interest in carbon nuclei for cancer treatment has led some vendors to offer carbon-ion and proton capability in their accelerator systems, so that either ion can be used. These features are now being incorporated for medical accelerators in new facilities.

  16. Collision integrals and the generalized kinetic equation for charged particle beams

    SciTech Connect

    Tzenov, S. I.

    1998-10-01

    In the present paper we study the role of particle interactions on the evolution of a high energy beam. The interparticle forces taken into account are due to space charge alone. We derive the collision integral for a charged particle beam in the form of Balescu-Lenard and Landau and consider its further simplifications. Finally, the transition to the generalized kinetic equation has been accomplished by using the method of adiabatic elimination of fast variables.

  17. Spectrometry of charged particles from inertial-confinement-fusion plasmas

    NASA Astrophysics Data System (ADS)

    Séguin, F. H.; Frenje, J. A.; Li, C. K.; Hicks, D. G.; Kurebayashi, S.; Rygg, J. R.; Schwartz, B.-E.; Petrasso, R. D.; Roberts, S.; Soures, J. M.; Meyerhofer, D. D.; Sangster, T. C.; Knauer, J. P.; Sorce, C.; Glebov, V. Yu.; Stoeckl, C.; Phillips, T. W.; Leeper, R. J.; Fletcher, K.; Padalino, S.

    2003-02-01

    High-resolution spectrometry of charged particles from inertial-confinement-fusion (ICF) experiments has become an important method of studying plasma conditions in laser-compressed capsules. In experiments at the 60-beam OMEGA laser facility [T. R. Boehly et al., Opt. Commun. 133, 495 (1997)], utilizing capsules with D2, D3He, DT, or DTH fuel in a shell of plastic, glass, or D2 ice, we now routinely make spectral measurements of primary fusion products (p, D, T, 3He, α), secondary fusion products (p), "knock-on" particles (p, D, T) elastically scattered by primary neutrons, and ions from the shell. Use is made of several types of spectrometers that rely on detection and identification of particles with CR-39 nuclear track detectors in conjunction with magnets and/or special ranging filters. CR-39 is especially useful because of its insensitivity to electromagnetic noise and its ability to distinguish the types and energies of individual particles, as illustrated here by detailed calibrations of its response to 0.1-13.8 MeV protons from a Van de Graaff accelerator and to p, D, T, and α from ICF experiments at OMEGA. A description of the spectrometers is accompanied by illustrations of their operating principles using data from OMEGA. Sample results and discussions illustrate the relationship of secondary-proton and knock-on spectra to capsule fuel and shell areal densities and radial compression ratios; the relationship of different primary fusion products to each other and to ion temperatures; the relationship of deviations from spherical symmetry in particle yields and energies to capsule structure; the acceleration of fusion products and the spectra of ions from the shell due to external fields; and other important physical characteristics of the laser-compressed capsules.

  18. Nonequatorial charged particle confinement around Kerr black holes

    NASA Astrophysics Data System (ADS)

    Preti, Giovanni

    2010-01-01

    We analyze the nonequatorial charged particle dynamics around a rotating black hole in the presence of an external magnetic field, the latter being given by Wald’s exact analytical solution to the Maxwell’s equations in the Kerr background. At variance with the corresponding Schwarzschild case, the behavior of the particle becomes here markedly charge-sign dependent, and the more so the more the Kerr parameter increases. The interplay between the rotating black hole and the magnetic field is shown to provide a mechanism both for selective charge ejection in axially collimated jetlike trajectories, and for selective charge confinement into nonequatorial bound orbits around the hole; the possibility of such a confinement allows the fate of an accreting particle to not necessarily be doomed: infall into the hole can be prevented, and the neutrality of the Kerr source could therefore be preserved, while the charge is safely parked into bound cross-equatorial orbits all around it.

  19. Nonequatorial charged particle confinement around Kerr black holes

    SciTech Connect

    Preti, Giovanni

    2010-01-15

    We analyze the nonequatorial charged particle dynamics around a rotating black hole in the presence of an external magnetic field, the latter being given by Wald's exact analytical solution to the Maxwell's equations in the Kerr background. At variance with the corresponding Schwarzschild case, the behavior of the particle becomes here markedly charge-sign dependent, and the more so the more the Kerr parameter increases. The interplay between the rotating black hole and the magnetic field is shown to provide a mechanism both for selective charge ejection in axially collimated jetlike trajectories, and for selective charge confinement into nonequatorial bound orbits around the hole; the possibility of such a confinement allows the fate of an accreting particle to not necessarily be doomed: infall into the hole can be prevented, and the neutrality of the Kerr source could therefore be preserved, while the charge is safely parked into bound cross-equatorial orbits all around it.

  20. Charged particle beam scanning using deformed high gradient insulator

    SciTech Connect

    Chen, Yu -Jiuan

    2015-10-06

    Devices and methods are provided to allow rapid deflection of a charged particle beam. The disclosed devices can, for example, be used as part of a hadron therapy system to allow scanning of a target area within a patient's body. The disclosed charged particle beam deflectors include a dielectric wall accelerator (DWA) with a hollow center and a dielectric wall that is substantially parallel to a z-axis that runs through the hollow center. The dielectric wall includes one or more deformed high gradient insulators (HGIs) that are configured to produce an electric field with an component in a direction perpendicular to the z-axis. A control component is also provided to establish the electric field component in the direction perpendicular to the z-axis and to control deflection of a charged particle beam in the direction perpendicular to the z-axis as the charged particle beam travels through the hollow center of the DWA.

  1. Traps for storing charged particles and antiparticles in high-precision experiments

    NASA Astrophysics Data System (ADS)

    Eseev, M. K.; Meshkov, I. N.

    2016-03-01

    The storage and confinement of charged particles and antiparticles (electrons, positrons, ions) in open traps and storage rings of various designs are considered. Experiments on positron storage in the Penning - Malmberg - Surko trap in the Low-Energy Particle Toroidal Accumulator (LEPTA) are described in detail.

  2. Proposal to Search for Magnetically Charged Particles with Magnetic Charge 1e

    SciTech Connect

    Sullivan, Michael K.; Fryberger, David

    2015-11-02

    A model for composite elementary Standard Model (SM) particles based upon magnetically bound vorton pairs, we briefly introduce here, predicts the existence of a complete family of magnetically charged particles, as well as their neutral isotopic partners (all counterparts to the SM elementary particles), in which the lowest mass (charged) particle would be an electrically neutral stable lepton, but which carries a magnetic charge equivalent to 1e. This new particle, which we call a magneticon (a counterpart to the electron) would be pair produced at all e+e- colliders at an Ecm above twice its mass. In addition, PP and PPbar colliders should also be able to produce these new particles through the Drell-Yan process. To our knowledge, no monopole search experiment has been sensitive to such a low-charged magnetic monopole above a particle mass of about 5 GeV/c2. Hence, we propose that a search for such a stable particle of magnetic charge 1e should be undertaken. We have taken the ATLAS detector at the LHC as an example in which this search might be done. To this end, we modeled the magnetic fields and muon trigger chambers of this detector. We show results from a simple Monte Carlo simulation program to indicate how these particles might look in the detector and describe how one might search for these new particles in the ATLAS data stream.

  3. An improved search for elementary particles with fractional electric charge

    SciTech Connect

    Lee, E.R.

    1996-08-01

    The SLAC Quark Search Group has demonstrated successful operation of a low cost, high mass throughput Millikan apparatus designed to search for fractionally charged particles. About six million silicone oil drops were measured with no evidence of fractional charges. A second experiment is under construction with 100 times greater throughput which will utilize optimized search fluids.

  4. Indirect Charged Particle Detection: Concepts and a Classroom Demonstration

    ERIC Educational Resources Information Center

    Childs, Nicholas B.; Horányi, Mihály; Collette, Andrew

    2013-01-01

    We describe the principles of macroscopic charged particle detection in the laboratory and their connections to concepts taught in the physics classroom. Electrostatic dust accelerator systems, capable of launching charged dust grains at hypervelocities (1-100 km/s), are a critical tool for space exploration. Dust grains in space typically have…

  5. Noncommutative magnetic moment of charged particles

    SciTech Connect

    Adorno, T. C.; Gitman, D. M.; Shabad, A. E.; Vassilevich, D. V.

    2011-10-15

    It has been argued that in noncommutative field theories, the sizes of physical objects cannot be taken smaller than an ''elementary length'' related to noncommutativity parameters. By gauge covariantly extending field equations of noncommutative U(1){sub *} theory to cover the presence of external sources, we find electric and magnetic fields produced by an extended static charge. We find that such a charge, apart from being an ordinary electric monopole, is also a magnetic dipole. By writing off the existing experimental clearance in the value of the lepton magnetic moments for the present effect, we get the bound on noncommutativity at the level of 10{sup 4} TeV.

  6. Optical characterization of electrically charged particles using discrete dipole approximation

    NASA Astrophysics Data System (ADS)

    Kocifaj, Miroslav; Kundracik, František; Videen, Gorden

    2016-11-01

    The dependence of the electric potential on the absorption and scattering of light by small particles has emerged as an interesting research topic, as the unexpected amplified optical signatures of a system of electrically charged particles were satisfactory predicted recently for homogeneous, uniformly charged spheres. However, natural particles are rarely of spherical shape. A comprehensive understanding of how arbitrarily shaped, charged particles interact with electromagnetic radiation has been missing. The approach we present here attempts to fill this gap by introducing a numerical formulation of the electromagnetic scattering problem for these particles. The first results from the intercomparison of numerical and analytical solutions for a pseudosphere show that the resonance features found are largely consistent, except for the magnitude and width of the peak amplitude, which may be due to inherent differences in the approaches used.

  7. Charged particle trajectories in the field of a charge near a Schwarzschild blackhole

    NASA Astrophysics Data System (ADS)

    Sonar, V. P.; Dhurandhar, S. V.; Dadhich, N.

    1985-12-01

    Motion of charged particles in the field of a charge placed near the Schwarzschild blackhole is considered. The electromagnetic field gets modified owing to gravitational field of the black hole. The system, charge plus the hole, is axisymmetric (no longer spherically symmetric) which poses difficulty in obtaining analytic solutions of equations of motion. However, motion along the axis and circular orbits about the axis of symmetry are discussed. In view of the asymmetry in charge distribution, a particle will have circular orbits only off the equatorial plane.

  8. The Influence of Trapped Ions and Non-equilibrium EDF on Dust Particle Charging

    SciTech Connect

    Sukhinin, G. I.; Fedoseev, A. V.; Antipov, S. N.; Petrov, O. F.; Fortov, V. E.

    2008-09-07

    Dust particles charging in a low-pressure glow discharge was investigated theoretically with the help of model for trapped and free ions coupled with the self-consistent solution of Poisson equation for electric potential. Non-equilibrium (non-Maxwellian) character of electron energy distribution function depending on gas pressure and electric field was also taken into account on the basis of the solution of kinetic Boltzmann equation. The results were compared with the experimental measurements of dust particle charge depending on gas pressure. It was shown that the calculated effective charge, i.e. the difference of the dust particle charge and trapped ion charge, is in a fairly good agreement with the experimental data.

  9. Fractional dynamics of charged particles in magnetic fields

    NASA Astrophysics Data System (ADS)

    Coronel-Escamilla, A.; Gómez-Aguilar, J. F.; Alvarado-Méndez, E.; Guerrero-Ramírez, G. V.; Escobar-Jiménez, R. F.

    2016-02-01

    In many physical applications the electrons play a relevant role. For example, when a beam of electrons accelerated to relativistic velocities is used as an active medium to generate Free Electron Lasers (FEL), the electrons are bound to atoms, but move freely in a magnetic field. The relaxation time, longitudinal effects and transverse variations of the optical field are parameters that play an important role in the efficiency of this laser. The electron dynamics in a magnetic field is a means of radiation source for coupling to the electric field. The transverse motion of the electrons leads to either gain or loss energy from or to the field, depending on the position of the particle regarding the phase of the external radiation field. Due to the importance to know with great certainty the displacement of charged particles in a magnetic field, in this work we study the fractional dynamics of charged particles in magnetic fields. Newton’s second law is considered and the order of the fractional differential equation is (0;1]. Based on the Grünwald-Letnikov (GL) definition, the discretization of fractional differential equations is reported to get numerical simulations. Comparison between the numerical solutions obtained on Euler’s numerical method for the classical case and the GL definition in the fractional approach proves the good performance of the numerical scheme applied. Three application examples are shown: constant magnetic field, ramp magnetic field and harmonic magnetic field. In the first example the results obtained show bistability. Dissipative effects are observed in the system and the standard dynamic is recovered when the order of the fractional derivative is 1.

  10. Search for multiply charged Heavy Stable Charged Particles in data collected with the CMS detector

    SciTech Connect

    Veeraraghavan, Venkatesh

    2013-10-30

    Several models of new physics yield particles that are massive, long-lived, and have an electric charge, Q, greater than that of the electron, e. A search for evidence of such particles was performed using 5.0 fb-1 and 18.8 fb-1 of proton-proton collision data collected at √s = 7 TeV and √s = 8 TeV, respectively, with the Compact Muon Solenoid detector at the Large Hadron Collider. The distinctive detector signatures of these particles are that they are slow-moving and highly ionizing. Ionization energy loss and time-of- flight measurements were made using the inner tracker and the muon system, respectively. The search is sensitive to 1e ≤ |Q| ≤ 8e. Data were found to be consistent with standard model expectations and upper limits on the production cross section of these particles were computed using a Drell-Yan-like production model. Masses below 517, 687, 752, 791, 798, 778, 753, and 724 GeV are excluded for |Q| = 1e, 2e, 3e, 4e, 5e, 6e, 7e, and 8e, respectively.

  11. Global Aspects of Charged Particle Motion in Axially Symmetric Multipole Magnetic Fields

    NASA Technical Reports Server (NTRS)

    Shebalin, John V.

    2003-01-01

    The motion of a single charged particle in the space outside of a compact region of steady currents is investigated. The charged particle is assumed to produce negligible electromagnetic radiation, so that its energy is conserved. The source of the magnetic field is represented as a point multipole. After a general description, attention is focused on magnetic fields with axial symmetry. Lagrangian dynamical theory is utilized to identify constants of the motion as well as the equations of motion themselves. The qualitative method of Stonner is used to examine charged particle motion in axisymmetric multipole fields of all orders. Although the equations of motion generally have no analytical solutions and must be integrated numerically to produce a specific orbit, a topological examination of dynamics is possible, and can be used, d la Stonner, to completely describe the global aspects of the motion of a single charged particle in a space with an axisymmetric multipole magnetic field.

  12. Measurement of charged-particle stopping in warm dense plasma.

    PubMed

    Zylstra, A B; Frenje, J A; Grabowski, P E; Li, C K; Collins, G W; Fitzsimmons, P; Glenzer, S; Graziani, F; Hansen, S B; Hu, S X; Johnson, M Gatu; Keiter, P; Reynolds, H; Rygg, J R; Séguin, F H; Petrasso, R D

    2015-05-29

    We measured the stopping of energetic protons in an isochorically heated solid-density Be plasma with an electron temperature of ∼32  eV, corresponding to moderately coupled [(e^{2}/a)/(k_{B}T_{e}+E_{F})∼0.3] and moderately degenerate [k_{B}T_{e}/E_{F}∼2] "warm-dense matter" (WDM) conditions. We present the first high-accuracy measurements of charged-particle energy loss through dense plasma, which shows an increased loss relative to cold matter, consistent with a reduced mean ionization potential. The data agree with stopping models based on an ad hoc treatment of free and bound electrons, as well as the average-atom local-density approximation; this work is the first test of these theories in WDM plasma. PMID:26066441

  13. A compilation of charged-particle induced thermonuclear reaction rates

    NASA Astrophysics Data System (ADS)

    Angulo, C.; Arnould, M.; Rayet, M.; Descouvemont, P.; Baye, D.; Leclercq-Willain, C.; Coc, A.; Barhoumi, S.; Aguer, P.; Rolfs, C.; Kunz, R.; Hammer, J. W.; Mayer, A.; Paradellis, T.; Kossionides, S.; Chronidou, C.; Spyrou, K.; degl'Innocenti, S.; Fiorentini, G.; Ricci, B.; Zavatarelli, S.; Providencia, C.; Wolters, H.; Soares, J.; Grama, C.; Rahighi, J.; Shotter, A.; Lamehi Rachti, M.

    1999-08-01

    Low-energy cross section data for 86 charged-particle induced reactions involving light (1 <=Z <=14), mostly stable, nuclei are compiled. The corresponding Maxwellian-averaged thermonuclear reaction rates of relevance in astrophysical plasmas at temperatures in the range from 106 K to 1010 K are calculated. These evaluations assume either that the target nuclei are in their ground state, or that the target states are thermally populated following a Maxwell-Boltzmann distribution, except in some cases involving isomeric states. Adopted values complemented with lower and upper limits of the rates are presented in tabular form. Analytical approximations to the adopted rates, as well as to the inverse/direct rate ratios, are provided.

  14. Charge balance for the mesosphere with meteoric dust particles

    NASA Astrophysics Data System (ADS)

    Asmus, H.; Robertson, S.; Dickson, S.; Friedrich, M.; Megner, L.

    2015-05-01

    An aerosol particle charging model initially developed for noctilucent cloud ice particles has been extended in several steps in order to better explain the data for charged meteoric smoke particles (MSPs) obtained by the nighttime and daytime CHAMPS rockets launched from Andøya, Norway, in October 2011. Addition of photodetachment to the model shows that this process reduces the number density of positively charged MSPs as well as the number density of negatively charged MSPs as a consequence of the photodetached electrons neutralizing the positively charged MSPs. In addition, the model shows that the ionization rate can be deduced from the electron number density and the electron-ion recombination rate only at the highest altitudes (those with ionization rates above 20 cm-3 s-1) as a consequence of recombination on the MSPs being dominant at lower altitudes. The differences between the daytime and the nighttime rocket data suggest a photodetachment rate between 0.1 and 0.01 s-1. A further extension of the model to include the formation of negative ions and their destruction helps explain the ledge seen in the number density of the lightest negatively charged particles. The MSP number densities that are the inputs to the charging model are taken from the CARMA/CHEM2D model. The CHAMPS data are more consistent with number densities generated with an assumed input flux from ablation of 4 t d-1 than with 44 t d-1 assumed previously.

  15. Charge Balance in the Mesosphere with Meteoric Dust Particles

    NASA Astrophysics Data System (ADS)

    Robertson, S. H.; Asmus, H.; Dickson, S.; Friedrich, M.; Megner, L. S.

    2013-12-01

    An aerosol particle charging model developed initially for noctilucent cloud particles has been extended in several steps in order to better explain data for charged meteoric smoke particles (MSPs) returned by the nighttime and daytime CHAMPS rockets launched from the Andøya rocket Range, Norway, in October 2011. Addition of photodetachment to the model shows that this process reduces the number density of positively charged MSPs as well as the number density of negatively charged MSPs as a consequence of the photodetached electrons neutralizing the positively charged MSPs. In addition, the model shows that the ionization rate can be deduced from the electron number density and the electron-ion recombination rate only at the highest altitudes as a consequence of recombination of electrons on the MSPs at lower altitudes. The differences between the daytime and nighttime data place constraints on the photodetachment rate. A further extension of the model to include the formation of negative ions and their destruction by atomic oxygen helps explain the ledge seen in the number density of the lightest negatively charged particles. MSP particle densities from the CARMA/CHEM2D model are in better agreement with rocket data for assumed values of the meteor input flux that are at the low end of the generally accepted range.

  16. Self-sustaining charging of identical colliding particles.

    PubMed

    Siu, Theo; Cotton, Jake; Mattson, Gregory; Shinbrot, Troy

    2014-05-01

    Recent experiments have demonstrated that identical material samples can charge one another after being brought into symmetric contact. The mechanism for this charging is not known. In this article, we use a simplified one-dimensional lattice model to analyze charging in the context of agitated particles. We find that the electric field from a single weakly polarized grain can feed back on itself by polarizing its neighbors, leading to an exponential growth in polarization. We show that, by incorporating partial neutralization between neighboring polarized particles, either uniform alignment of dipoles or complex charge and polarization waves can be produced. We reproduce a polarized state experimentally using identical colliding particles and raise several issues for future study. PMID:25353788

  17. Theoretical model of a soft particle with charged core

    NASA Astrophysics Data System (ADS)

    Tracy, Dustin; Phan, Anh

    2014-03-01

    The numerical and analytical solutions of the electrostatic potentials of soft particles with an ion-permeable charged outer layer and a non-permeable charged core with constant charge densities are found using the Poisson-Boltzmann equations. The charged core is found to significantly alter the local potential within the soft particle, yet it has little effect on the potential outside its particle's boundaries. Previous experimental research into the electrical properties of the MS2 virus agree with these findings. Our results also suggest that there is only a slight change in the potential as the temperature is increased from 290 K to 310 K. The potential profile is found to be significantly affected by the ionic strength in the 1-600 mM range.

  18. Charged and Neutral Particles Channeling Phenomena Channeling 2008

    NASA Astrophysics Data System (ADS)

    Dabagov, Sultan B.; Palumbo, Luigi

    2010-04-01

    On the discovery of coherent Bremsstrahlung in a single crystal at the Frascati National Laboratories / C. Barbiellini, G. P. Murtas and S. B. Dabagov -- Advances in coherent Bremsstrahlung and LPM-effect studies (to the lOOth anniversary from the birth of L. D. Landau) / N. F. Shul'ga -- Spectra of radiation and created particles at intermediate energy in oriented crystal taking into account energy loss / V. N. Baier and V. M. Katkov -- The coherent Bremsstrahlung beam at MAX-lab facility / K. Fissum ... [et al.] -- Radiation from thin, structured targets (CERN NA63) / A. Dizdar -- Hard incoherent radiation in thick crystals / N. F. Shul'ga, V. V. Syshchenko and A. I. Tarnovsky -- Coherent Bremsstrahlung in periodically deformed crystals with a complex base / A. R. Mkrtchyan, A. A. Saharian and V. V. Parazian -- Induction of coherent x-ray Bremsstrahlung in crystals under the influence of acoustic waves / A. R. Mkrtchyan and V. V. Parazian -- Coherent processes in bent single crystals / V. A. Maisheev -- Experimental and theoretical investigation of complete transfer phenomenon for media with various heat exchange coefficients / A. R. Mkrtchyan, A. E. Movsisyan and V. R. Kocharyan -- Coherent pair production in crystals / A. R. Mkrtchyan, A. A. Saharian and V. V. Parazian -- Negative particle planar and axial channeling and channeling collimation / R. A. Carrigan, Jr. -- CERN crystal-based collimation in modern hadron colliders / W. Scandale -- Studies and application of bent crystals for beam steering at 70 GeV IHEP accelerator / A. G. Afonin ... [et al.] -- Crystal collimation studies at the Tevatron (T-980) / N. V. Mokhov ... [et al.] -- Fabrication of crystals for channeling of particles in accellerators / A. Mazzolari ... [et al.] -- New possibilities to facilitate collimation of both positively and negatively charged particle beams by crystals / V. Guidi, A. Mazzolari and V. V. Tikhomirov -- Increase of probability of particle capture into the channeling

  19. Simulating the transport of heavy charged particles through trabecular spongiosa

    NASA Astrophysics Data System (ADS)

    Gersh, Jacob A.

    As planning continues for manned missions far beyond Low Earth Orbit, a paramount concern remains the flight crew's exposure to galactic cosmic radiation. When humans exit the protective magnetic field of Earth, they become subject to bombardment by highly-reactive heavy charged (HZE) particles. A possible consequence of this two- to three-year-long mission is the onset of radiation-induced leukemia, a disorder with a latency period as short as two to three years. Because data on risk to humans from exposure to HZE particles is non-existent, studies of leukemia in animals are now underway to investigate the relative effectiveness of HZE exposures. Leukemogenesis can result from energy depositions occurring within marrow contained in the trabecular spongiosa. Trabecular spongiosa is found in flat bones and within the ends of long bones, and is characterized by an intricate matrix of interconnected bone tissue forming cavities that house marrow. The microscopic internal dimensions of spongiosa vary between species. As radiation traverses this region, interface-induced dose perturbations that occur at the interfaces between bone and marrow affect the patterns of energy deposition within the region. An aim of this project is to determine the extent by which tissue heterogeneity and microscopic dimensions have on patterns of energy deposition within the trabecular spongiosa. This leads to the development of PATHFIT, a computer code capable of generating simple quadric-based geometric models of trabecular spongiosa for both humans and mice based on actual experimentally-determined internal dimensions of trabecular spongiosa. Following the creation of spongiosa models, focus is placed on the development of HITSPAP, a hybrid Monte Carlo (MC) radiation transport code system that combines capabilities of the MC code PENELOPE and MC code PARTRAC. This code is capable of simulating the transport of HZE particles through accurate models of trabecular spongiosa. The final and

  20. Motion of charged test particles in Reissner-Nordstroem spacetime

    SciTech Connect

    Pugliese, Daniela; Quevedo, Hernando; Ruffini, Remo

    2011-05-15

    We investigate the circular motion of charged test particles in the gravitational field of a charged mass described by the Reissner-Nordstroem spacetime. We study in detail all the spatial regions where circular motion is allowed around either black holes or naked singularities. The effects of repulsive gravity are discussed by finding all the circles at which a particle can have vanishing angular momentum. We show that the geometric structure of stable accretion disks, made of only test particles moving along circular orbits around the central body, allows us to clearly distinguish between black holes and naked singularities.

  1. Magnetospheric vortex formation: self-organized confinement of charged particles.

    PubMed

    Yoshida, Z; Saitoh, H; Morikawa, J; Yano, Y; Watanabe, S; Ogawa, Y

    2010-06-11

    A magnetospheric configuration gives rise to various peculiar plasma phenomena that pose conundrums to astrophysical studies; at the same time, innovative technologies may draw on the rich physics of magnetospheric plasmas. We have created a "laboratory magnetosphere" with a levitating superconducting ring magnet. Here we show that charged particles (electrons) self-organize a stable vortex, in which particles diffuse inward to steepen the density gradient. The rotating electron cloud is sustained for more than 300 s. Because of its simple geometry and self-organization, this system will have wide applications in confining single- and multispecies charged particles. PMID:20867249

  2. Kinetic phenomena in charged particle transport in gases and plasmas

    SciTech Connect

    Petrovic, Zoran Lj.; Dujko, Sasa; Sasic, Olivera; Stojanovic, Vladimir; Malovic, Gordana

    2012-05-25

    The key difference between equilibrium (thermal) and non-equilibrium (low temperature - a.k.a. cold) plasmas is in the degree in which the shape of the cross sections influences the electron energy distribution function (EEDF). In this paper we will discuss the issue of kinetic phenomena from two different angles. The first will be how to take advantage of the strong influence and use low current data to obtain the cross sections. This is also known as the swarm technique and the product of a ''swarm analysis'' is a set of cross sections giving good number, momentum and energy balances of electrons or other charged particles. At the same time understanding the EEDF is based on the cross section data. Nevertheless sometimes the knowledge of the cross sections and even the behaviour of individual particles are insufficient to explain collective behaviour of the ensemble. The resulting ''kinetic'' effects may be used to favour certain properties of non-equilibrium plasmas and even may be used as the basis of some new plasma applications.

  3. Late time CMB anisotropies constrain mini-charged particles

    SciTech Connect

    Burrage, C.; Redondo, J.; Ringwald, A.; Jaeckel, J. E-mail: joerg.jaeckel@durham.ac.uk E-mail: andreas.ringwald@desy.de

    2009-11-01

    Observations of the temperature anisotropies induced as light from the CMB passes through large scale structures in the late universe are a sensitive probe of the interactions of photons in such environments. In extensions of the Standard Model which give rise to mini-charged particles, photons propagating through transverse magnetic fields can be lost to pair production of such particles. Such a decrement in the photon flux would occur as photons from the CMB traverse the magnetic fields of galaxy clusters. Therefore late time CMB anisotropies can be used to constrain the properties of mini-charged particles. We outline how this test is constructed, and present new constraints on mini-charged particles from observations of the Sunyaev-Zel'dovich effect in the Coma cluster.

  4. Systems for detecting charged particles in object inspection

    DOEpatents

    Morris, Christopher L.; Makela, Mark F.

    2013-08-20

    Techniques, apparatus and systems for detecting particles such as muons. In one implementation, a monitoring system has a cosmic ray-produced charged particle tracker with a plurality of drift cells. The drift cells, which can be for example aluminum drift tubes, can be arranged at least above and below a volume to be scanned to thereby track incoming and outgoing charged particles, such as cosmic ray-produced muons, while also detecting gamma rays. The system can selectively detect devices or materials, such as iron, lead, gold and/or tungsten, occupying the volume from multiple scattering of the charged particles passing through the volume and can also detect any radioactive sources occupying the volume from gamma rays emitted therefrom. If necessary, the drift tubes can be sealed to eliminate the need for a gas handling system. The system can be employed to inspect occupied vehicles at border crossings for nuclear threat objects.

  5. Multipole radiation in charged-particle scattering

    NASA Technical Reports Server (NTRS)

    Gould, Robert J.

    1990-01-01

    This paper formulates the general problem of photon emission in particle scattering using a classical and quantum mechanical approach. The connection between the classical short collision time (SCT) and Born results is examined for various special classifications of problems. In the dipole case the two formulations yield results that can be expressed in the same form and for arbitrary scattering potential. For quadrupole emission the SCT and Born results are the same only for a short-range potential, however. The quadrupole problem is more sensitive to details in the process because the calculation requires an expansion of the total amplitude for the process to lowest order in the photon wave number or momentum. The special case of photon emission associated with spin-flip transitions during scattering is considered for spin-1/2 particles. Like classical magnetic dipole radiation, there is no infrared divergence feature for this type of emission.

  6. Diffusiophoretic mobility of charge-regulating porous particles.

    PubMed

    Li, Wei C; Keh, Huan J

    2016-08-01

    The diffusiophoresis of a charge-regulating porous sphere, such as polyelectrolyte coil, with an arbitrary thickness of the electric double layer in an electrolyte solution prescribed with a concentration gradient is analytically studied for the first time. The ionogenic functional groups and hydrodynamic frictional segments distribute uniformly within the permeable particle, and a charge regulation model for the association and dissociation reactions of the functional groups relates the fixed charge density to the local electric potential. The electrokinetic equations governing the electric potential, ionic electrochemical potential, and fluid velocity distributions are solved as power-series expansions in the basic fixed charge density. An explicit formula for the diffusiophoretic mobility of the particle, which vanishes at the isoelectric point, is derived from a force balance. The effects of charge regulation on the diffusiophoretic mobility, which depend on various particle and electrolyte characteristics such as the reaction equilibrium constants of the ionogenic functional groups, are significant and interesting. The variation in the bulk concentration of the charge-determining ions can produce more than one reversal in the direction of the diffusiophoretic velocity. The obtained results differ conspicuously from those of impermeable particles and provide valuable information for the interpretation of experimental data.

  7. How to model the interaction of charged Janus particles

    NASA Astrophysics Data System (ADS)

    Hieronimus, Reint; Raschke, Simon; Heuer, Andreas

    2016-08-01

    We analyze the interaction of charged Janus particles including screening effects. The explicit interaction is mapped via a least square method on a variable number n of systematically generated tensors that reflect the angular dependence of the potential. For n = 2 we show that the interaction is equivalent to a model previously described by Erdmann, Kröger, and Hess (EKH). Interestingly, this mapping is for n = 2 not able to capture the subtleties of the interaction for small screening lengths. Rather, a larger number of tensors has to be used. We find that the characteristics of the Janus type interaction plays an important role for the aggregation behavior. We obtained cluster structures up to the size of 13 particles for n = 2 and 36 and screening lengths κ-1 = 0.1 and 1.0 via Monte Carlo simulations. The influence of the screening length is analyzed and the structures are compared to results for an electrostatic-type potential and for the multipole-expanded Derjaguin-Landau-Verwey-Overbeek (DLVO) theory. We find that a dipole-like potential (EKH or dipole DLVO approximation) is not able to sufficiently reproduce the anisotropy effects of the potential. Instead, a higher order expansion has to be used to obtain cluster structures that are compatible with experimental observations. The resulting minimum-energy clusters are compared to those of sticky hard sphere systems. Janus particles with a short-range screened interaction resemble sticky hard sphere clusters for all considered particle numbers, whereas for long-range screening even very small clusters are structurally different.

  8. ENERGETIC CHARGED PARTICLES ASSOCIATED WITH STRONG INTERPLANETARY SHOCKS

    SciTech Connect

    Giacalone, Joe

    2012-12-10

    We analyze observations of energetic charged particles associated with many strong interplanetary shocks seen by Advanced Composition Explorer. We focus primarily on 47-187 keV suprathermal protons and restrict our analysis to strong interplanetary shocks (Alfven Mach number >3 and the shock density compression >2.5). Eighteen shocks meeting this criterion from 1998 to 2003 were analyzed. All 18 had enhancements of the 47-65 keV proton intensity above the intensity seen one day before the shock. In 17 events, the particle intensity either rose to a quasi-plateau or peaked within 10 minutes of the shock. Most had intensities at the shock exceeding 100 times more than that seen the day before the shock arrived. The time-intensity profiles of the energetic proton events in many cases reveal a rise before the shock passage reaching a quasi-plateau or local peak at the shock, followed by a gradual decline. This suggests that the shock itself is the source of energetic particles. Energy spectra behind the shock were fit to an assumed power law over the interval from 46 to 187 keV, and the resulting spectral index was compared to the plasma density jump across each shock. Most events agree with the prediction of diffusive shock acceleration theory to within the observational uncertainties. We also analyzed a few selected events to determine the particle spatial diffusion coefficients and acceleration timescales. We find that the time to accelerate protons to {approx}50 keV is of the order of an hour.

  9. Analysis of ``soft`` recovered shaped charge jet particles

    SciTech Connect

    Lassila, D.H.; Nikkel, D.J. Jr.; Kershaw, R.P.; Walters, W.P.

    1996-04-01

    A shaped charge with an 81 mm diameter, 42{degree} apex angle oxygen-free high-conductivity (OFHC) copper conical liner was fired into a ``soft`` recovery bunker to allow metallurgical examination of recovered jet particles and the slug. The initial weight of the copper liner was 245 g, of which 184 g was recovered. The number of jet particles recovered was 37 (approximately 63% of the particles formed by the charge). Extensive metallurgical analyses were performed on the recovered slug and jet particles. The microstructural features associated with voids, e.g., dendritic grain growth, clearly indicate that the regions in the vicinity of the centerline of the slug and jet particles were melted. In this work the authors present calculations of jet temperature as a function of constitutive behavior. In order to predict melt in the center region of the jet they find it necessary to scale flow stress with a pressure dependent shear modulus.

  10. Roles of the major, small, acid-soluble spore proteins and spore-specific and universal DNA repair mechanisms in resistance of Bacillus subtilis spores to ionizing radiation from X rays and high-energy charged-particle bombardment.

    PubMed

    Moeller, Ralf; Setlow, Peter; Horneck, Gerda; Berger, Thomas; Reitz, Günther; Rettberg, Petra; Doherty, Aidan J; Okayasu, Ryuichi; Nicholson, Wayne L

    2008-02-01

    The role of DNA repair by nonhomologous end joining (NHEJ), homologous recombination, spore photoproduct lyase, and DNA polymerase I and genome protection via alpha/beta-type small, acid-soluble spore proteins (SASP) in Bacillus subtilis spore resistance to accelerated heavy ions (high-energy charged [HZE] particles) and X rays has been studied. Spores deficient in NHEJ and alpha/beta-type SASP were significantly more sensitive to HZE particle bombardment and X-ray irradiation than were the recA, polA, and splB mutant and wild-type spores, indicating that NHEJ provides an efficient DNA double-strand break repair pathway during spore germination and that the loss of the alpha/beta-type SASP leads to a significant radiosensitivity to ionizing radiation, suggesting the essential function of these spore proteins as protectants of spore DNA against ionizing radiation.

  11. Study of Deformation Effects in the Charged Particle Emission from 46Ti*

    NASA Astrophysics Data System (ADS)

    Brekiesz, M.; Papka, P.; Maj, A.; Kmiecik, M.; Beck, C.; Bednarczyk, P.; Grebosz, J.; Haas, F.; Meczynski, W.; Rauch, V.; Rousseau, M.; Zafra, A. Sanchez I.; Styczen, J.; Thummerer, S.; Zieblinski, M.; Zuber, K.

    2005-04-01

    The 46Ti* compound nucleus, as populated by the fusion--evaporation reaction 27Al + 19F at the bombarding energy of 144MeV, has been investigated by charged particle spectroscopy using the multidetector array ICARE at the VIVITRON tandem facility of the IReS (Strasbourg). The light charged particles have been measured in coincidence with evaporation residues. The CACARIZO} code, a Monte Carlo implementation of the statistical model code CASCADE, has been used to calculate the spectral shapes of evaporated α -particles which are compared with the experimental spectra. This comparison indicates the possible signature of large deformations of the compound nucleus.

  12. Search for new, long-lived, charged particles using ionization in the ATLAS Pixel Detector

    NASA Astrophysics Data System (ADS)

    Axen, Bradley; Atlas Collaboration

    2016-03-01

    Several extensions of the Standard Model predict the existence of charged, very massive, and long-lived particles. Because of their high masses these particles would propagate non-relativistically through the ATLAS pixel detector and are therefore be identifiable through a measurement of large specific energy loss. Measuring heavy, long-lived particles through their track parameters in the pixel detector allows sensitivity to particles with lifetimes in the nanosecond range and above. This search presents an inner detector driven method for identifying such particles in proton-proton collisions at 13 TeV with the 2015 dataset corresponding to an integrated luminosity of 3.5 pb-1.

  13. Static analysis of possible emittance growth of intense charged particle beams with thermal equilibrium distribution

    SciTech Connect

    Kikuchi, Takashi; Horioka, Kazuhiko

    2009-05-15

    Possible emittance growths of intense, nonuniform beams during a transport in a focusing channel are derived as a function of nonlinear field energy and space charge tune depression factors. The nonlinear field energy of the beam with thermal equilibrium distribution is estimated by considering the particle distribution across the cross section of the beam. The results show that the possible emittance growth can be suppressed by keeping the beam particle in thermal equilibrium distribution during the beam transport.

  14. Complex Kepler Orbits and Particle Aggregation in Charged Microscopic Grains

    NASA Astrophysics Data System (ADS)

    Lee, Victor; Waitukaitis, Scott; Miskin, Marc; Jaeger, Heinrich

    2015-03-01

    Kepler orbits are usually associated with the motion of astronomical objects such as planets or comets. Here we observe such orbits at the microscale in a system of charged, insulating grains. By letting the grains fall freely under vacuum, we eliminate the effects of air drag and gravity, and by imaging them with a co-falling high-speed camera we track the relative positions of individual particles with high spatial and temporal precision. This makes it possible to investigate the behaviors caused by the combination of long-range electrostatic interactions and short-range, dissipative, contact interactions in unprecedented detail. We make the first direct observations of microscopic elliptical and hyperbolic Kepler orbits, collide-and-capture events between pairs of charged grains, and particle-by-particle aggregation into larger clusters. Our findings provide experimental evidence for electrostatic mechanisms that have been suspected, but not previously observed at the single-event level, as driving the early stages of particle aggregation in systems ranging from fluidized particle bed reactors to interstellar protoplanetary disks. Furthermore, since particles of different net charge and size are seen to aggregate into characteristic spatial configurations, our results suggest new possibilities for the formation of charge-stabilized ``granular molecules''. We can reproduce the observed molecule configurations by taking many-body, dielectric polarization effects into account.

  15. Highly Charged Particles Cause a Larger Current Blockage in Micropores Compared to Neutral Particles.

    PubMed

    Qiu, Yinghua; Lin, Chih-Yuan; Hinkle, Preston; Plett, Timothy S; Yang, Crystal; Chacko, Jenu Varghese; Digman, Michelle A; Yeh, Li-Hsien; Hsu, Jyh-Ping; Siwy, Zuzanna S

    2016-09-27

    Single pores in the resistive-pulse technique are used as an analytics tool to detect, size, and characterize physical as well as chemical properties of individual objects such as molecules and particles. Each object passing through a pore causes a transient change of the transmembrane current called a resistive pulse. In high salt concentrations when the pore diameter is significantly larger than the screening Debye length, it is assumed that the particle size and surface charge can be determined independently from the same experiment. In this article we challenge this assumption and show that highly charged hard spheres can cause a significant increase of the resistive-pulse amplitude compared to neutral particles of a similar diameter. As a result, resistive pulses overestimate the size of charged particles by even 20%. The observation is explained by the effect of concentration polarization created across particles in a pore, revealed by numerical modeling of ionic concentrations, ion current, and local electric fields. It is notable that in resistive-pulse experiments with cylindrical pores, concentration polarization was previously shown to influence ionic concentrations only at pore entrances; consequently, additional and transient modulation of resistive pulses was observed when a particle entered or left the pore. Here we postulate that concentration polarization can occur across transported particles at any particle position along the pore axis and affect the magnitude of the entire resistive pulse. Consequently, the recorded resistive pulses of highly charged particles reflect not only the particles' volume but also the size of the depletion zone created in front of the moving particle. Moreover, the modeling identified that the effective surface charge density of particles depended not only on the density of functional groups on the particle but also on the capacitance of the Stern layer. The findings are of crucial importance for sizing particles and

  16. Early experiments in charged particle beams from the Space Shuttle

    NASA Technical Reports Server (NTRS)

    Raitt, W. J.; Banks, P. M.; Williamson, P. R.; Baker, K. D.; Obayashi, T.; Burch, J. L.

    1982-01-01

    Characteristics of studies on board the Shuttle involving the interaction of particle beams with the atmosphere and the ionosphere, and the effects of the beams on the electrical potential of the platform, are discussed. Noting that the Shuttle allows greater weight and power demands by scientific payloads than previous satellite launches, the OSS-1 Vehicle Charging and Potential experiment and the Spacelab 1 Particle Accelerator and Phenomena Induced by Charged Particle Beams are described. Instrumentation details are provided, including charge and current probes, the Spherical Retarding Potential Analyzer, the Fast Pulse Electron Generator, and digital control and interface units. The SEPAC equipment, which comprises an electron beam accelerator, and MPD plasma jet, and diagnostic units are detailed, and operating procedures and experiment objectives are outlined.

  17. Hybrid finite element and Brownian dynamics method for charged particles

    NASA Astrophysics Data System (ADS)

    Huber, Gary A.; Miao, Yinglong; Zhou, Shenggao; Li, Bo; McCammon, J. Andrew

    2016-04-01

    Diffusion is often the rate-determining step in many biological processes. Currently, the two main computational methods for studying diffusion are stochastic methods, such as Brownian dynamics, and continuum methods, such as the finite element method. A previous study introduced a new hybrid diffusion method that couples the strengths of each of these two methods, but was limited by the lack of interactions among the particles; the force on each particle had to be from an external field. This study further develops the method to allow charged particles. The method is derived for a general multidimensional system and is presented using a basic test case for a one-dimensional linear system with one charged species and a radially symmetric system with three charged species.

  18. APPARATUS FOR CLEANING GASES WITH ELECTROSTATICALLY CHARGED PARTICLES

    DOEpatents

    Johnstone, H.F.

    1960-02-01

    An apparatus is described for cleaning gases with the help of electrostatically charged pellets. The pellets are blown past baffles in a conduit and into the center of a rotuting body of the gas to be cleaned. The pellets are charged electrostatically by impinging on the baffles. The pellets collect the particles suspended in the gas in their passage from the center of the rotating body to its edge.

  19. Light charged particles emitted in fission reactions induced by protons on 208Pb

    NASA Astrophysics Data System (ADS)

    Rodríguez-Sánchez, J. L.; Benlliure, J.; Paradela, C.; Ayyad, Y.; Casarejos, E.; Alvarez-Pol, H.; Audouin, L.; Bélier, G.; Boutoux, G.; Chatillon, A.; Cortina-Gil, D.; Gorbinet, T.; Heinz, A.; Kelić-Heil, A.; Laurent, B.; Martin, J.-F.; Pellereau, E.; Pietras, B.; Ramos, D.; Rodríguez-Tajes, C.; Rossi, D. M.; Simon, H.; Taïeb, J.; Vargas, J.; Voss, B.

    2016-09-01

    Light charged particles emitted in proton-induced fission reactions on 208Pb have been measured at different kinetic energies: 370 A ,500 A , and 650 A MeV. The experiment was performed by the SOFIA Collaboration at the GSI facilities in Darmstadt (Germany). The inverse kinematics technique was combined with a setup especially designed to measure light charged particles in coincidence with fission fragments. This measurement allowed us, for the first time, to obtain correlations between the light charged particles emitted during the fission process and the charge distributions of the fission fragments. These correlations were compared with different model calculations to assess the ground-to-saddle dynamics. The results confirm that transient and dissipative effects are required for an accurate description of the fission observables.

  20. Self-Assembly of Heterogeneously Charged Particles under Confinement

    PubMed Central

    2013-01-01

    Self-assembly—the spontaneous organization of microscopic units into well-defined mesoscopic structures—is a fundamental mechanism for a broad variety of nanotechnology applications in material science. The central role played by the anisotropy resulting from asymmetric shapes of the units and/or well-defined bonding sites on the particle surface has been widely investigated, highlighting the importance of properly designing the constituent entities in order to control the resulting mesoscopic structures. Anisotropy driven self-assembly can also result from the multipolar interactions characterizing many naturally occurring systems, such as proteins and viral capsids, as well as experimentally synthesized colloidal particles. Heterogeneously charged particles represent a class of multipolar units that are characterized by a competitive interplay between anisotropic attractive and repulsive interactions, due to the repulsion/attraction between charged-like/oppositely charged regions on the particle surface. In the present work, axially symmetric quadrupolar colloids are considered in a confined planar geometry; the role of both the overall particle charge and the patch extension as well as the effect of the substrate charge are studied in thermodynamic conditions such that the formation of extended structures is favored. A general tendency to form quasi-two-dimensional aggregates where particles align their symmetry axes within the plane is observed; among these planar self-assembled scenarios, a clear distinction between the formation of microcrystalline gels—branched networks consisting of purely crystalline domains—as opposed to disordered aggregates can be observed based on the specific features of the particle–particle interaction. Additionally, the possible competition of interparticle and particle–substrate interactions affects the size and the internal structure of the aggregates and can possibly inhibit the aggregation process. PMID:23627740

  1. Electrostatic plasma lens for focusing negatively charged particle beams.

    PubMed

    Goncharov, A A; Dobrovolskiy, A M; Dunets, S M; Litovko, I V; Gushenets, V I; Oks, E M

    2012-02-01

    We describe the current status of ongoing research and development of the electrostatic plasma lens for focusing and manipulating intense negatively charged particle beams, electrons, and negative ions. The physical principle of this kind of plasma lens is based on magnetic isolation electrons providing creation of a dynamical positive space charge cloud in shortly restricted volume propagating beam. Here, the new results of experimental investigations and computer simulations of wide-aperture, intense electron beam focusing by plasma lens with positive space charge cloud produced due to the cylindrical anode layer accelerator creating a positive ion stream towards an axis system is presented.

  2. Autogenerator of beams of charged particles

    DOEpatents

    Adler, R.J.; Mazarakis, M.G.; Miller, R.M.; Shope, S.L.; Smith, D.L.

    1983-10-31

    An autogenerating apparatus provides secondary intense relativistic current beam pulses in response to an injected beam pulse. One or more electromagnetic energy storage devices are provided in conjunction with gaps along a beam propagation path for the injected beam pulse. For injected beam pulses which are no longer than double the transit time of electromagnetic waves within the storage devices (which may be resonant cavities), distinct secondary beam pulses are generated by each of the energy storage devices. The beam propagation path, together with the one or more gaps provided therein, operates as a pulse forming transmission line cavity, in which the separate cavities associated with the gaps provide delays for electromagnetic waves generated at the gaps. After doubly traversing the cavity, the electromagnetic waves cause the gap to generate the secondary beam pulses, which are thus delayed by a time interval equal to the double transit time for the induced wave within the cavity.

  3. Autogenerator of beams of charged particles

    DOEpatents

    Adler, Richard J.; Mazarakis, Michael G.; Miller, Robert B.; Shope, Steven L.; Smith, David L.

    1986-01-01

    An autogenerating apparatus provides secondary intense relativistic current beam pulses in response to an injected beam pulse. One or more electromagnetic energy storage devices are provided in conjunction with gaps along a beam propagation path for the injected beam pulse. For injected beam pulses which are no longer than double the transit time of electromagnetic waves within the storage devices (which may be resonant cavities), distinct secondary beam pulses are generated by each of the energy storage devices. The beam propagation path, together with the one or more gaps provided therein, operates as a pulse forming transmission line cavity, in which the separate cavities associated with the gaps provide delays for electromagnetic waves generated at the gaps. After doubly traversing the cavity, the electromagnetic waves cause the gap to generate the secondary beam pulses, which are thus delayed by a time interval equal to the double transit time for the induced wave within the cavity.

  4. Theory of using magnetic deflections to combine charged particle beams

    SciTech Connect

    Steckbeck, Mackenzie K.; Doyle, Barney Lee

    2014-09-01

    Several radiation effects projects in the Ion Beam Lab (IBL) have recently required two disparate charged particle beams to simultaneously strike a single sample through a single port of the target chamber. Because these beams have vastly different mass–energy products (MEP), the low-MEP beam requires a large angle of deflection toward the sample by a bending electromagnet. A second electromagnet located further upstream provides a means to compensate for the small angle deflection experienced by the high-MEP beam during its path through the bending magnet. This paper derives the equations used to select the magnetic fields required by these two magnets to achieve uniting both beams at the target sample. A simple result was obtained when the separation of the two magnets was equivalent to the distance from the bending magnet to the sample, and the equations is given by: Bs= 1/2(rc/rs) Bc, where Bs and Bc are the magnetic fields in the steering and bending magnet and rc/rs is the ratio of the radii of the bending magnet to that of the steering magnet. This result is not dependent upon the parameters of the high MEP beam, i.e. energy, mass, charge state. Therefore, once the field of the bending magnet is set for the low-MEP beam, and the field in the steering magnet is set as indicted in the equation, the trajectory path of any high-MEP beam will be directed into the sample.

  5. The telegraph equation in charged particle transport

    NASA Technical Reports Server (NTRS)

    Gombosi, T. I.; Jokipii, J. R.; Kota, J.; Lorencz, K.; Williams, L. L.

    1993-01-01

    We present a new derivation of the telegraph equation which modifies its coefficients. First, an infinite order partial differential equation is obtained for the velocity space solid angle-averaged phase-space distribution of particles which underwent at least a few collisions. It is shown that, in the lowest order asymptotic expansion, this equation simplifies to the well-known diffusion equation. The second-order asymptotic expansion for isotropic small-angle scattering results in a modified telegraph equation with a signal propagation speed of v(5/11) exp 1/2 instead of the usual v/3 exp 1/2. Our derivation of a modified telegraph equation follows from an expansion of the Boltzmann equation in the relevant smallness parameters and not from a truncation of an eigenfunction expansion. This equation is consistent with causality. It is shown that, under steady state conditions in a convecting plasma, the telegraph equation may be regarded as a diffusion equation with a modified transport coefficient, which describes a combination of diffusion and cosmic-ray inertia.

  6. Charged-Particle Spectra Using Particle Tracking on a Two-Dimensional Grid

    NASA Astrophysics Data System (ADS)

    Radha, P. B.; Delettrez, J. A.; Epstein, R.; Skupsky, S.; Soures, J. M.; Cremer, S.; Petrasso, R. D.

    1999-11-01

    IRIS-2D is an extension of the spherically symmetric Monte Carlo particle-tracking code IRIS. It tracks particles on a two-dimensional Lagrangian grid and will be used as a post- processor to 2-D hydrocodes to simulate experimental neutron and charged-particle spectra. In this talk, we use IRIS-2D to study the effect of asymmetry and instability-induced mix on the knock-on deuteron (deuterons elastically scattered off the 14-MeV DT neutron) spectrum and its angular distribution. We will present time-integrated knock-on deuteron spectra obtained by post-processing implosion calculations using the 2-D hydrocode ORCHID. Preliminary comparisons of these spectra with experiment will be presented. This work was supported by the U.S. Department of Energy Office of Inertial Confinement Fusion under Cooperative Agreement No. DE-FC03-92SF19460, the University of Rochester, and the New York State Energy Research and Development Authority.

  7. Charged Particle Spectroscopy on Omega (Final report)

    SciTech Connect

    Fletcher, K.; Padalino, S.; Schwartz, B.; Olsen, M.; Wakeman, T.; Petrasso, R.

    2001-01-01

    Using the 2-MeV Van de Graaf Accelerator at SUNY Geneseo's Nuclear Structure Laboratory, a {sup 3}He-implanted tantalum target was bombarded by 450-keV deuterons to produce high energy protons via the {sup 3}He(d,p){sup 4}He reaction. A 1500-{micro}m surface barrier detector with a 3/16 inch diameter collimator was placed at 8.75 cm from the target and 135{sup o} from the incident beam. A movable arm was setup so that an array of aluminum filters of varying thicknesses could be rotated in front of the detector. A 6-{micro}m mylar filter was also mounted on the movable arm and was used to calibrate the detector as described in the CR-39 experiment report. Eight aluminum filters with thicknesses ranging from 250pm to 1100{micro}m were in turn rotated in front of the collimator and spectra were taken for each. The results are shown on the attached graphs. The theoretical curve for each graph was generated using TRIM The exact energy distribution of the proton beam incident on the target was not known; because no such spectrum could be taken due to the high count rate for elastically scattered deuterons. Instead, it was assumed that the incident beam had a distribution similar to that measured through the 6-{micro}m mylar, namely, an average energy of 13.798 MeV with a standard deviation of 0.027 MeV. A program developed locally was used to generate an input file for TRIM with this distribution. Using this input file, TRIM simulations were run for various thicknesses of Aluminum, from 200 to 1100 {micro}m in 50-{micro}m increments. The solid line on the graph indicates the energies of the transmitted protons. The two dashed lines indicate one standard deviation above and below the average exit energy. TRIM agrees well with the experimental results.

  8. The "Puck" energetic charged particle detector: Design, heritage, and advancements

    NASA Astrophysics Data System (ADS)

    Clark, G.; Cohen, I.; Westlake, J. H.; Andrews, G. B.; Brandt, P.; Gold, R. E.; Gkioulidou, M. A.; Hacala, R.; Haggerty, D.; Hill, M. E.; Ho, G. C.; Jaskulek, S. E.; Kollmann, P.; Mauk, B. H.; McNutt, R. L.; Mitchell, D. G.; Nelson, K. S.; Paranicas, C.; Paschalidis, N.; Schlemm, C. E.

    2016-08-01

    Energetic charged particle detectors characterize a portion of the plasma distribution function that plays critical roles in some physical processes, from carrying the currents in planetary ring currents to weathering the surfaces of planetary objects. For several low-resource missions in the past, the need was recognized for a low-resource but highly capable, mass-species-discriminating energetic particle sensor that could also obtain angular distributions without motors or mechanical articulation. This need led to the development of a compact Energetic Particle Detector (EPD), known as the "Puck" EPD (short for hockey puck), that is capable of determining the flux, angular distribution, and composition of incident ions between an energy range of ~10 keV to several MeV. This sensor makes simultaneous angular measurements of electron fluxes from the tens of keV to about 1 MeV. The same measurements can be extended down to approximately 1 keV/nucleon, with some composition ambiguity. These sensors have a proven flight heritage record that includes missions such as MErcury Surface, Space ENvironment, GEochemistry, and Ranging and New Horizons, with multiple sensors on each of Juno, Van Allen Probes, and Magnetospheric Multiscale. In this review paper we discuss the Puck EPD design, its heritage, unexpected results from these past missions and future advancements. We also discuss high-voltage anomalies that are thought to be associated with the use of curved foils, which is a new foil manufacturing processes utilized on recent Puck EPD designs. Finally, we discuss the important role Puck EPDs can potentially play in upcoming missions.

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

    NASA Astrophysics Data System (ADS)

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

    2011-12-01

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

  10. Generation of narrow peaks in spectroscopy of charged particles

    NASA Astrophysics Data System (ADS)

    Dubbers, Dirk; Schmidt, Ulrich

    2016-11-01

    In spectroscopy of charged particles, narrow peaks may appear in continuous spectra if magnetic transport of the particles is involved. These artefacts, which so far have escaped the attention of investigators, can develop whenever geometric detection efficiency is less than 100%. As such peaks may be misinterpreted as new physics, their generation is investigated, both analytically and experimentally, for various detector configurations, including those used in searches for the spontaneous decay of the vacuum in heavy-ion collisions.

  11. Charged particle track reconstruction using artificial neural networks

    SciTech Connect

    Glover, C.; Fu, P.; Gabriel, T.; Handler, T.

    1992-12-31

    This paper summarizes the current state of our research in developing and applying artificial neural network (ANN) algorithm described here is based on a crude model of the retina. It takes as input the coordinates of each charged particle`s interaction point (``hit``) in the tracking chamber. The algorithm`s output is a set of vectors pointing to other hits that most likely to form a track.

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

    NASA Astrophysics Data System (ADS)

    Nouicer, R.

    2016-03-01

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

  13. O the Penetration of Fast-Charged Particles.

    NASA Astrophysics Data System (ADS)

    Perry, David John

    The work presented here is intended to provide theoretical support for medical physicists who are interested in improving radiotherapy treatment plans involving charged particle beams. These plans still rely heavily on empirical behavior rather than theory as a basis for making predictions. In the most frequent therapy applications, electron beams, typically with initial energies between 5-20 MeV, penetrate materials of low atomic number. Energy loss is predominately by ionization and the effects of multiple scattering by repeated Coulomb deflections from nuclei are of primary interest. Our development is strongly influenced by these applications and so we begin our work with a review of Fermi-Eyges theory. This theory and ideas which were equivalent to it have dramatically improved electron beam treatment plans over the last several years, as is now generally recognized. This theory also has significant limitations due to the approximations or assumptions that it makes. Since we can improve and extend these results by relaxing some of the key assumptions, we continue by considering some generalizations of this basic theory and we discuss those which were given by Snyder-Scott, Lewis and Yang in some detail. Yang's theory had significant potential for applications but this theory will not work properly unless its time development is handled differently. This leads us to present a wave solution to the penetration problem in our final chapter. Sample calculations of the most important distributions are given there as well.

  14. A novel silicon array designed for intraoperative charged particle imaging.

    PubMed

    Tornai, Martin P; Patt, Bradley E; Iwanczyk, Jan S; Tull, Carolyn R; MacDonald, Lawrence R; Hoffman, Edward J

    2002-11-01

    A novel Si-PIN imaging array is under investigation for a charged particle (beta, positron, or alpha) sensitive intraoperative camera to be used for (residual) tumor identification during surgery. This class of collimator-less nuclear imaging device has a higher signal response for direct interactions than its scintillator-optical detector-based counterparts. Monte Carlo simulations with 635 keV betas were performed, yielding maximum and projected ranges of 1.64 and 0.55 mm in Si. Up to 90% of these betas were completely absorbed in the first 0.30 mm. Based on these results, 300 microm thick prototype Si detector arrays were designed in a 16 x 16 crossed-grid arrangement with 0.8 mm wide orthogonal strips on 1.0 mm pitch. A NIM- and CAMAC-based high-density data acquisition and processing system was used to collect the list mode data. The system was calibrated by comparisons of measured spectra to energy deposition simulations or by direct measurement of various >100 keV conversion electron or beta emitters. Mean electronic noise per strip was <3.6 keV FWHM at room temperature. When detecting positrons, which have an accompanying 511 keV annihilation background, the flood irradiated beta/gamma ratio was approximately 40, indicating that beta images could be made without the use of background rejection techniques. The intrinsic spatial resolution corresponds to the 1 x 1 mm2 pixel size, and measurements of beta emitting point and line sources yielded FWHM resolutions of 1.5 (lateral) and 2.5 mm (diagonal), respectively, with the larger widths due to particle range blurting effects. Deconvolution of the finite source size yielded intrinsic resolutions that corresponded to the image pixel size. Transmission images of circle and line phantoms with various hole sizes and pitch were resolved with either pure beta or positron irradiation without a background correction. This novel semiconductor imaging device facilitates high charged particle and low gamma sensitivity

  15. Method of measuring a profile of the density of charged particles in a particle beam

    DOEpatents

    Hyman, L.G.; Jankowski, D.J.

    1975-10-01

    A profile of the relative density of charged particles in a beam is obtained by disposing a number of rods parallel to each other in a plane perpendicular to the beam and shadowing the beam. A second number of rods is disposed perpendicular to the first rods in a plane perpendicular to the beam and also shadowing the beam. Irradiation of the rods by the beam of charged particles creates radioactive isotopes in a quantity proportional to the number of charged particles incident upon the rods. Measurement of the radioactivity of each of the rods provides a measure of the quantity of radioactive material generated thereby and, together with the location of the rods, provides information sufficient to identify a profile of the density of charged particles in the beam.

  16. Charged Particle Optics in Circular Higgs Factory

    SciTech Connect

    Cai, Yunhai

    2015-02-26

    Similar to a super B-factory, a circular Higgs factory will require strong focusing systems near the interaction points and a low-emittance lattice in arcs to achieve a factory luminosity. At electron beam energy of 120 GeV, beamstrahlung effects during the collision pose an additional challenge to the collider design. In particular, a large momentum acceptance at 2 percent level is necessary to retain an adequate beam lifetime. This turns out to be the most challenging aspect in the design of circular Higgs factory. In this paper, an example will be provided to illustrate the beam dynamics in circular Higgs factory, emphasizing on the chromatic optics. Basic optical modules and advanced analysis will be presented. Most important, we will show that 2% momentum aperture is achievable

  17. On magnetic guidance of charged particles

    NASA Astrophysics Data System (ADS)

    Backe, H.

    2016-04-01

    High precision beta decay experiments with polarized neutrons, employing magnetic guiding fields for the decay electrons in combination with energy dispersive detectors, initiated detailed studies of the point spread function (PSF) for homogeneous magnetic fields. A PSF describes the radial probability distribution of mono-energetic electrons at the detector plane which were emitted from a point-like source. With regard to accuracy considerations for high-precision experiments unwanted singularities occur as function of the radial detector coordinate which have recently been discussed in detail by Dubbers (2015) [3]. In the present article mathematical inconsistencies in the approximations to calculate PSFs have been corrected. In addition, numerical orbit calculations have been performed for inhomogeneous magnetic fields which show that, on the one hand, generalizations on the basis of adiabaticity considerations must be handled with care but indicate, on the other hand, that non-adiabaticity would not prevent a proposed check of magnetic field configurations.

  18. Charge Identification of Highly Ionizing Particles in Desensitized Nuclear Emulsion Using High Speed Read-Out System

    SciTech Connect

    Toshito, T.; Kodama, K.; Yusa, K.; Ozaki, M.; Amako, K.; Kameoka, S.; Murakami, K.; Sasaki, T.; Aoki, S.; Ban, T.; Fukuda, T.; Naganawa, N.; Nakamura, T.; Natsume, M.; Niwa, K.; Takahashi, S.; Kanazawa, M.; Kanematsu, N.; Komori, M.; Sato, S.; Asai, M.; /Nagoya U. /Aichi U. of Education /Gunma U., Maebashi /JAXA, Sagamihara /KEK, Tsukuba /Kobe U. /Chiba, Natl. Inst. Rad. Sci. /SLAC /Toho U.

    2006-05-10

    We performed an experimental study of charge identification of heavy ions from helium to carbon having energy of about 290 MeV/u using an emulsion chamber. Emulsion was desensitized by means of forced fading (refreshing) to expand a dynamic range of response to highly charged particles. For the track reconstruction and charge identification, the fully automated high speed emulsion read-out system, which was originally developed for identifying minimum ionizing particles, was used without any modification. Clear track by track charge identification up to Z=6 was demonstrated. The refreshing technique has proved to be a powerful technique to expand response of emulsion film to highly ionizing particles.

  19. Silicon PIN diode array hybrids for charged particle detection

    SciTech Connect

    Shapiro, S.L.; Dunwoodie, W.M.; Arens, J.F.; Jernigan, J.G.; Gaalema, S.

    1988-09-01

    We report on the design of silicon PIN diode array hybrids for use as charged particle detectors. A brief summary of the need for vertex detectors is presented. Circuitry, block diagrams and device specifications are included. 8 refs., 7 figs., 1 tab.

  20. Thermodynamic model for bouncing charged particles inside a capacitor

    NASA Astrophysics Data System (ADS)

    Rezaeizadeh, Amin; Mameghani, Pooya

    2013-08-01

    We introduce an equation of state for a conducting particle inside a charged parallel-plate capacitor and show that it is similar to the equation of state for an ideal gas undergoing an adiabatic process. We describe a simple experiment that shows reasonable agreement with the theoretical model.

  1. Electromagnetic field of fractal distribution of charged particles

    SciTech Connect

    Tarasov, Vasily E.

    2005-08-15

    Electric and magnetic fields of fractal distribution of charged particles are considered. The fractional integrals are used to describe fractal distribution. The fractional integrals are considered as approximations of integrals on fractals. Using the fractional generalization of integral Maxwell equation, the simple examples of the fields of homogeneous fractal distribution are considered. The electric dipole and quadrupole moments for fractal distribution are derived.

  2. Some developments in neutron and charged particle dosimetry.

    PubMed

    Bos, Adrie J J; d'Errico, Francesco

    2006-01-01

    There is an increasing need for dosimetry of neutrons and charged particles. Increasing exposure levels are reported in the nuclear industry, deriving from more frequent in-service entries at commercial nuclear power plants, and from increased plant decommissioning and refurbishment activities. Another need stems from the compliance with requirements of the regulations and standards. The European Council directive 96/29 requires dosimetric precautions if the effective dose exceeds 1 mSv a(-1). On average, aircrew members exceed this value. Further, there is a trend of increasing use of charged particles in radiotherapy. The present situation is that we have reasonably good photon dosemeters, but neutron and charged particle dosemeters are still in need of improvements. This work highlights some of the developments in this field. It is mainly concentrated on some developments in passive dosimetry, in particular thermally and optically stimulated luminescent detectors, indicating the direction of ongoing research. It shows that passive dosemeters are still a very active field. Active dosemeters will not be discussed with the exception of new developments in microdosimetric measurements [new types of tissue equivalent proportional counters (TEPCs)]. The TEPC is unique in its ability to provide a simultaneous determination of neutron / charged particle / gamma ray doses, or dose equivalents using a single detector. PMID:16987918

  3. Functionally charged nanosize particles differentially activate BV2 microglia.

    EPA Science Inventory

    The effect of particle surface charge on the biological activation of immortalized mouse microglia (BV2) was examined. Nanosize (860-950 nm) spherical polystyrene microparticles (SPM) were coated with carboxyl (COOH-) or dimethyl amino (CH3)2-N- groups to give a net negative or p...

  4. Electrostatic interactions between charged dielectric particles in an electrolyte solution.

    PubMed

    Derbenev, Ivan N; Filippov, Anatoly V; Stace, Anthony J; Besley, Elena

    2016-08-28

    Theory is developed to address a significant problem of how two charged dielectric particles interact in the presence of a polarizable medium that is a dilute solution of a strong electrolyte. The electrostatic force is defined by characteristic parameters for the interacting particles (charge, radius, and dielectric constant) and for the medium (permittivity and Debye length), and is expressed in the form of a converging infinite series. The limiting case of weak screening and large inter-particle separation is considered, which corresponds to small (macro)ions that carry constant charge. The theory yields a solution in the limit of monopole and dipole terms that agrees exactly with existing analytical expressions, which are generally used to describe ion-ion and ion-molecular interactions in a medium. Results from the theory are compared with DLVO theory and with experimental measurements for the electrostatic force between two PMMA particles contained in a nonpolar solvent (hexadecane) with an added charge control agent. PMID:27586900

  5. Charged particle in higher dimensional weakly charged rotating black hole spacetime

    SciTech Connect

    Frolov, Valeri P.; Krtous, Pavel

    2011-01-15

    We study charged particle motion in weakly charged higher dimensional black holes. To describe the electromagnetic field we use a test field approximation and the higher dimensional Kerr-NUT-(A)dS metric as a background geometry. It is shown that for a special configuration of the electromagnetic field, the equations of motion of charged particles are completely integrable. The vector potential of such a field is proportional to one of the Killing vectors (called a primary Killing vector) from the 'Killing tower' of symmetry generating objects which exists in the background geometry. A free constant in the definition of the adopted electromagnetic potential is proportional to the electric charge of the higher dimensional black hole. The full set of independent conserved quantities in involution is found. We demonstrate that Hamilton-Jacobi equations are separable, as is the corresponding Klein-Gordon equation and its symmetry operators.

  6. Scintillator-fiber charged particle track-imaging detector

    NASA Technical Reports Server (NTRS)

    Binns, W. R.; Israel, M. H.; Klarmann, J.

    1983-01-01

    A scintillator-fiber charged-particle track-imaging detector was developed using a bundle of square cross section plastic scintillator fiber optics, proximity focused onto an image intensified charge injection device (CID) camera. The tracks of charged particle penetrating into the scintillator fiber bundle are projected onto the CID camera and the imaging information is read out in video format. The detector was exposed to beams of 15 MeV protons and relativistic Neon, Manganese, and Gold nuclei and images of their tracks were obtained. Details of the detector technique, properties of the tracks obtained, and preliminary range measurements of 15 MeV protons stopping in the fiber bundle are presented.

  7. Helium measurements simulating alpha-particle diagnostics by the pellet charge exchange in Large Helical Device

    NASA Astrophysics Data System (ADS)

    Ozaki, T.; Goncharov, P.; Veschev, E.; Sudo, S.; Tamura, N.; ,

    2008-03-01

    It is very important to investigate the confinement of α particle, which is produced by the nuclear reaction in ITER or fusion reactor. The pellet charge exchange measurement (PCX) is one of the most powerful methods because it can directly provide the profile of α particle energy spectra in plasma. In Large Helical Device (LHD), it is possible to confine the high energetic particle (helium) accelerated by using the ion cyclotron resonance heating (ICH). Therefore it is possible to perform the simulation experiment of α particle diagnostic in LHD.

  8. ULF Waves and Diffusive Radial Transport of Charged Particles

    NASA Astrophysics Data System (ADS)

    Ali, Ashar Fawad

    The Van Allen radiation belts contain highly energetic particles which interact with a variety of plasma and magnetohydrodynamic (MHD) waves. Waves in the ultra low-frequency (ULF) range play an important role in the loss and acceleration of energetic particles. Considering the geometry of the geomagnetic field, charged particles trapped in the inner magnetosphere undergo three distinct types of periodic motions; an adiabatic invariant is associated with each type of motion. The evolution of the phase space density of charged particles in the magnetosphere in the coordinate space of the three adiabatic invariants is modeled by the Fokker-Planck equation. If we assume that the first two adiabatic invariants are conserved while the third invariant is violated, then the general Fokker-Planck equation reduces to a radial diffusion equation with the radial diffusion coefficient quantifying the rate of the radial diffusion of charged particles, including contributions from perturbations in both the magnetic and the electric fields. This thesis investigates two unanswered questions about ULF wave-driven radial transport of charged particles. First, how important are the ULF fluctuations in the magnetic field compared with the ULF fluctuations in the electric field in driving the radial diffusion of charged particles in the Earth's inner magnetosphere? It has generally been accepted that magnetic field perturbations dominate over electric field perturbations, but several recently published studies suggest otherwise. Second, what is the distribution of ULF wave power in azimuth, and how does ULF wave power depend upon radial distance and the level of geomagnetic activity? Analytic treatments of the diffusion coefficients generally assume uniform distribution of power in azimuth, but in situ measurements suggest that this may not be the case. We used the magnetic field data from the Combined Release and Radiation Effects Satellite (CRRES) and the electric and the magnetic

  9. Monitoring of Hadrontherapy Treatments by Means of Charged Particle Detection

    PubMed Central

    Muraro, Silvia; Battistoni, Giuseppe; Collamati, Francesco; De Lucia, Erika; Faccini, Riccardo; Ferroni, Fernando; Fiore, Salvatore; Frallicciardi, Paola; Marafini, Michela; Mattei, Ilaria; Morganti, Silvio; Paramatti, Riccardo; Piersanti, Luca; Pinci, Davide; Rucinski, Antoni; Russomando, Andrea; Sarti, Alessio; Sciubba, Adalberto; Solfaroli-Camillocci, Elena; Toppi, Marco; Traini, Giacomo; Voena, Cecilia; Patera, Vincenzo

    2016-01-01

    The interaction of the incoming beam radiation with the patient body in hadrontherapy treatments produces secondary charged and neutral particles, whose detection can be used for monitoring purposes and to perform an on-line check of beam particle range. In the context of ion-therapy with active scanning, charged particles are potentially attractive since they can be easily tracked with a high efficiency, in presence of a relatively low background contamination. In order to verify the possibility of exploiting this approach for in-beam monitoring in ion-therapy, and to guide the design of specific detectors, both simulations and experimental tests are being performed with ion beams impinging on simple homogeneous tissue-like targets (PMMA). From these studies, a resolution of the order of few millimeters on the single track has been proven to be sufficient to exploit charged particle tracking for monitoring purposes, preserving the precision achievable on longitudinal shape. The results obtained so far show that the measurement of charged particles can be successfully implemented in a technology capable of monitoring both the dose profile and the position of the Bragg peak inside the target and finally lead to the design of a novel profile detector. Crucial aspects to be considered are the detector positioning, to be optimized in order to maximize the available statistics, and the capability of accounting for the multiple scattering interactions undergone by the charged fragments along their exit path from the patient body. The experimental results collected up to now are also valuable for the validation of Monte Carlo simulation software tools and their implementation in Treatment Planning Software packages. PMID:27536555

  10. Monitoring of Hadrontherapy Treatments by Means of Charged Particle Detection.

    PubMed

    Muraro, Silvia; Battistoni, Giuseppe; Collamati, Francesco; De Lucia, Erika; Faccini, Riccardo; Ferroni, Fernando; Fiore, Salvatore; Frallicciardi, Paola; Marafini, Michela; Mattei, Ilaria; Morganti, Silvio; Paramatti, Riccardo; Piersanti, Luca; Pinci, Davide; Rucinski, Antoni; Russomando, Andrea; Sarti, Alessio; Sciubba, Adalberto; Solfaroli-Camillocci, Elena; Toppi, Marco; Traini, Giacomo; Voena, Cecilia; Patera, Vincenzo

    2016-01-01

    The interaction of the incoming beam radiation with the patient body in hadrontherapy treatments produces secondary charged and neutral particles, whose detection can be used for monitoring purposes and to perform an on-line check of beam particle range. In the context of ion-therapy with active scanning, charged particles are potentially attractive since they can be easily tracked with a high efficiency, in presence of a relatively low background contamination. In order to verify the possibility of exploiting this approach for in-beam monitoring in ion-therapy, and to guide the design of specific detectors, both simulations and experimental tests are being performed with ion beams impinging on simple homogeneous tissue-like targets (PMMA). From these studies, a resolution of the order of few millimeters on the single track has been proven to be sufficient to exploit charged particle tracking for monitoring purposes, preserving the precision achievable on longitudinal shape. The results obtained so far show that the measurement of charged particles can be successfully implemented in a technology capable of monitoring both the dose profile and the position of the Bragg peak inside the target and finally lead to the design of a novel profile detector. Crucial aspects to be considered are the detector positioning, to be optimized in order to maximize the available statistics, and the capability of accounting for the multiple scattering interactions undergone by the charged fragments along their exit path from the patient body. The experimental results collected up to now are also valuable for the validation of Monte Carlo simulation software tools and their implementation in Treatment Planning Software packages.

  11. Monitoring of Hadrontherapy Treatments by Means of Charged Particle Detection.

    PubMed

    Muraro, Silvia; Battistoni, Giuseppe; Collamati, Francesco; De Lucia, Erika; Faccini, Riccardo; Ferroni, Fernando; Fiore, Salvatore; Frallicciardi, Paola; Marafini, Michela; Mattei, Ilaria; Morganti, Silvio; Paramatti, Riccardo; Piersanti, Luca; Pinci, Davide; Rucinski, Antoni; Russomando, Andrea; Sarti, Alessio; Sciubba, Adalberto; Solfaroli-Camillocci, Elena; Toppi, Marco; Traini, Giacomo; Voena, Cecilia; Patera, Vincenzo

    2016-01-01

    The interaction of the incoming beam radiation with the patient body in hadrontherapy treatments produces secondary charged and neutral particles, whose detection can be used for monitoring purposes and to perform an on-line check of beam particle range. In the context of ion-therapy with active scanning, charged particles are potentially attractive since they can be easily tracked with a high efficiency, in presence of a relatively low background contamination. In order to verify the possibility of exploiting this approach for in-beam monitoring in ion-therapy, and to guide the design of specific detectors, both simulations and experimental tests are being performed with ion beams impinging on simple homogeneous tissue-like targets (PMMA). From these studies, a resolution of the order of few millimeters on the single track has been proven to be sufficient to exploit charged particle tracking for monitoring purposes, preserving the precision achievable on longitudinal shape. The results obtained so far show that the measurement of charged particles can be successfully implemented in a technology capable of monitoring both the dose profile and the position of the Bragg peak inside the target and finally lead to the design of a novel profile detector. Crucial aspects to be considered are the detector positioning, to be optimized in order to maximize the available statistics, and the capability of accounting for the multiple scattering interactions undergone by the charged fragments along their exit path from the patient body. The experimental results collected up to now are also valuable for the validation of Monte Carlo simulation software tools and their implementation in Treatment Planning Software packages. PMID:27536555

  12. Neutron-induced charged-particle emission studies below 100 MeV at WNR

    SciTech Connect

    Haight, R.C.; Lee, T.M.; Sterbenz, S.M.

    1994-07-01

    Charged-particles produced by neutron bombardment of selected targets with Z=5 through 53 have been studied for neutron energies from 1 MeV to about 100 MeV using the spallation neutron source at WNR/LAMPF. Particle detection with energy measurement and particle identification is accomplished by two-element {Delta}E-E counters, three-element {Delta}E{sub l}-{Delta}E{sub 2}-E counters or with pulse-shape discrimination using scintillators directly in the neutron beam. The experimental techniques for these measurements are described and comparisons made among the different approaches. This presentation introduces five papers contributed to this conference.

  13. Space charge effects in the SSC Low Energy Booster

    SciTech Connect

    Machida, S.; Bourianoff, G.; Mahale, N.K.; Mehta, N.; Pilat, F.; Talman, R.; York, R.C.

    1991-05-01

    By means of multi-particle tracking, we explore space charge effects in the Low Energy Booster (LEB) which has a strong requirement for small transverse emittance. Macro-particles are tracked in a self-consistent manner in six dimensional phase space with transverse space charge kicks so that the emittance evolution as well as the particle distribution are simulated as a function of time. Among recent improvements of the code, the longitudinal motion, i.e. synchrotron oscillations as well as acceleration, makes it possible to simulate the capture process of linac microbunches. The code was calibrated by comparing with the experimental results at the Fermilab Booster. Preliminary results of the LEB show slow emittance growth due to the space charge. 5 refs., 5 figs., 1 tab.

  14. Peculiarities of charged particle dynamics under cyclotron resonance conditions

    NASA Astrophysics Data System (ADS)

    Moiseev, S. S.; Buts, V. A.; Erokhin, N. S.

    2016-08-01

    Peculiarities of the dynamics of charged particles interacting with electromagnetic radiation under nearly autoresonance conditions are analyzed. In particular, analysis of nonlinear cyclotron resonances shows that their widths increase when the autoresonance conditions are approached. In this case, however, the distance between nonlinear resonances increases even faster, due to which nonlinear resonances do not overlap and, accordingly, regimes with dynamic chaos do not occur. According to calculations, the dynamics of charged particles under the autoresonance conditions is very sensitive to fluctuations, the effect of which can be anomalously large and lead to superdiffusion. It is shown that, under the autoresonance conditions, particle dynamics on small time intervals can differ significantly from that on large time intervals. This effect is most pronounced in the presence of fluctuations in the system.

  15. Search for fractionally charged particles in Kamiokande II

    SciTech Connect

    Mori, M.; Oyama, Y.; Suzuki, A.; Takahashi, K.; Yamada, M. , Ibaraki 305, Japan ); Miyano, K.; Miyata, H.; Takei, H. ); Hirata, K.S.; Kajita, T.; Kihara, K.; Nakahata, M.; Nakamura, K.; Ohara, S.; Sato, N.; Suzuki, Y.; Totsuka, Y.; Yaginuma, Y. ); Koshiba, M. ); Suda, T.; Tajima, T. ); Fukuda, Y.; Nagashima, Y.; Takita, M. ); Kaneyuki, K.; Tanimori, T. ); Beier, E.W.; Frank, E.D.; Frati, W.; Kim, S.B.; Mann, A.K.; Newcomer, F.M.; Van Berg, R.; Zhang, W. (Department of Physics, University of Pennsylvania, Philadelphia, Pennsylvania 19104 (USA

    1991-05-01

    A search has been made for fractionally charged particles with {vert bar}{ital Q}{vert bar}=1/3 and {vert bar}{ital Q}{vert bar}=2/3 which might have passed through the Kamiokande II detector. No positive evidence for such particles is observed in 1009 days of observation. The 90%-C.L. upper limits obtained on the fluxes of fractionally charged particles are 2.1{times}10{sup {minus}15} cm{sup {minus}2} s{sup {minus}1} sr{sup {minus}1} for {vert bar}{ital Q}{vert bar}=1/3 and 2.3{times}10{sup {minus}15} cm{sup {minus}2} s{sup {minus}1} sr{sup {minus}1} for {vert bar}{ital Q}{vert bar}=2/3, improving the existing limits by two orders of magnitude.

  16. Brownian dynamics of charged particles in a constant magnetic field

    SciTech Connect

    Hou, L. J.; Piel, A.; Miskovic, Z. L.; Shukla, P. K.

    2009-05-15

    Numerical algorithms are proposed for simulating the Brownian dynamics of charged particles in an external magnetic field, taking into account the Brownian motion of charged particles, damping effect, and the effect of magnetic field self-consistently. Performance of these algorithms is tested in terms of their accuracy and long-time stability by using a three-dimensional Brownian oscillator model with constant magnetic field. Step-by-step recipes for implementing these algorithms are given in detail. It is expected that these algorithms can be directly used to study particle dynamics in various dispersed systems in the presence of a magnetic field, including polymer solutions, colloidal suspensions, and, particularly, complex (dusty) plasmas. The proposed algorithms can also be used as thermostat in the usual molecular dynamics simulation in the presence of magnetic field.

  17. Stochastic acceleration of charged particle in nonlinear wave field

    NASA Astrophysics Data System (ADS)

    He, Kaifen

    2003-04-01

    Possibility of stochastic acceleration of charged particle by nonlinear waves is investigated. Spatially regular (SR) and spatiotemporal chaotic (STC) wave solutions evolving from saddle steady wave are tested as the fields. In the non-steady SR field the particle is finally trapped by the wave and averagely gains its group velocity, while in the STC field the particle motion displays trapped-free phases with its averaged velocity larger or smaller than the group velocity depending on the charge sign. A simplified model is established to investigate the acceleration mechanism. By analogy with motor protein, it is found that the virtual pattern of saddle steady wave plays a role of asymmetric potential, which and the nonlinear varying perturbation wave are the two sufficient ingredients for the acceleration in our case.

  18. Experimental and evaluated nuclear plus interference cross sections for light charged particles

    SciTech Connect

    Perkins, S.T.; Cullen, D.E.

    1980-07-04

    Experimental and evaluated integral parameters derived from nuclear plus interference differential elastic scattering cross sections are presented for all projectile/target combinations of the particles p, d, t, /sup 3/He, and ..cap alpha... The data include reaction rates, average fractional energy losses per collision and per unit path length, and average laboratory scattering cosines. The resulting parameters are of potential use in analysis of charged-particle transport.

  19. Registration of new stable heavy charged particles in cosmic rays

    NASA Astrophysics Data System (ADS)

    Bazhutov, Yu. N.

    2001-08-01

    A telescope of two coaxial scintillation detectors (an upper ∅63x0.35 mm 2 thin CsI crystal and a lower thick ∅150x100 mm 2 NaI crystal) positioned vertically on the Earth surface has recorded 23 events within T=106 hours. All the events (except for three background events) are within two standard deviations from a curve calculated for singl?-charged non-relativistic particles with mass ME = (175±25) GeV/c 2 that traverse the telescope from a vertical. On assumption that the particles recorded are not relativistic, from the geometrical size of the telescope it follows that their lifetime is τE>1.5·10 -9 s. Their intensity in cosmic rays on the Earth surface JE = (1.8±0.4)10 -6 cm -2 sr -1 s -1 (at EE≤6 GeV, PE≤50 GeV/c). This particles recorded conform completely to our phenomenological predictions, to our earlier experimental results obtained when searching for particles like those, and to the predictions of the «mirror» model that offers theoretical support to the existence of the hypothetical stable heavy hadrons (Erzions). INTRODUCTION. The hypothesis about new penetrating stable heavy hadrons [1,2] was proposed to explain the anomalous slope of cosmic muon energy spectra [3,4,5]. Many of the characteristics of the hypothesized hadrons (mass, charge, lifetime, intensity, nuclear interaction mode, interaction and absorption paths) were predicted phenomenologically to harmonize the very copious anomalous and ordinary experimental cosmic ray data and to make them consistent. There are many different experiments in cosmic rays, which indicate on existence of stable heavy particles [6-15], but there are no any simple and correct proofs until now. Later, we made attempts to find them experimentally [16-21] and to construct a model that would offer a theoretical support to their long lifetime (τ>10 -5 s), given their very high mass (M>30 GeV/c 2 ). The pioneer attempts were made using the super symmetrical model [22], but the use of the «mirror» model

  20. Development of a Charged Particle Microbeam for Targeted and Single Particle Subcellular Irradiation

    SciTech Connect

    Yanch, Jacquelyn C.

    2004-03-12

    The development of a charged particle microbeam for single particle, subcellular irradiations at the Massachusetts Institute of Technology Laboratory for Accelerator Beam Applications (MIT LABA) was initiated under this NEER aeard. The Microbeam apparatus makes use of a pre-existing electrostatic accelerator with a horizontal beam tube.

  1. The Average Quality Factors by TEPC for Charged Particles

    NASA Technical Reports Server (NTRS)

    Kim, Myung-Hee Y.; Nikjoo, Hooshang; Cucinotta, Francis A.

    2004-01-01

    The quality factor used in radiation protection is defined as a function of LET, Q(sub ave)(LET). However, tissue equivalent proportional counters (TEPC) measure the average quality factors as a function of lineal energy (y), Q(sub ave)(Y). A model of the TEPC response for charged particles considers energy deposition as a function of impact parameter from the ion s path to the volume, and describes the escape of energy out of sensitive volume by delta-rays and the entry of delta rays from the high-density wall into the low-density gas-volume. A common goal for operational detectors is to measure the average radiation quality to within accuracy of 25%. Using our TEPC response model and the NASA space radiation transport model we show that this accuracy is obtained by a properly calibrated TEPC. However, when the individual contributions from trapped protons and galactic cosmic rays (GCR) are considered; the average quality factor obtained by TEPC is overestimated for trapped protons and underestimated for GCR by about 30%, i.e., a compensating error. Using TEPC's values for trapped protons for Q(sub ave)(y), we obtained average quality factors in the 2.07-2.32 range. However, Q(sub ave)(LET) ranges from 1.5-1.65 as spacecraft shielding depth increases. The average quality factors for trapped protons on STS-89 demonstrate that the model of the TEPC response is in good agreement with flight TEPC data for Q(sub ave)(y), and thus Q(sub ave)(LET) for trapped protons is overestimated by TEPC. Preliminary comparisons for the complete GCR spectra show that Q(sub ave)(LET) for GCR is approximately 3.2-4.1, while TEPC measures 2.9-3.4 for QQ(sub ave)(y), indicating that QQ(sub ave)(LET) for GCR is underestimated by TEPC.

  2. Surface charge features of kaolinite particles and their interactions

    NASA Astrophysics Data System (ADS)

    Gupta, Vishal

    Kaolinite is both a blessing and a curse. As an important industrial mineral commodity, kaolinite clays are extensively used in the paper, ceramic, paint, plastic and rubber industries. In all these applications the wettability, aggregation, dispersion, flotation and thickening of kaolinite particles are affected by its crystal structure and surface properties. It is therefore the objective of this research to investigate selected physical and surface chemical properties of kaolinite, specifically the surface charge of kaolinite particles. A pool of advanced analytical techniques such as XRD, XRF, SEM, AFM, FTIR and ISS were utilized to investigate the morphological and surface chemistry features of kaolinite. Surface force measurements revealed that the silica tetrahedral face of kaolinite is negatively charged at pH>4, whereas the alumina octahedral face of kaolinite is positively charged at pH<6, and negatively charged at pH>8. Based on electrophoresis measurements, the apparent iso-electric point for kaolinite particles was determined to be less than pH 3. In contrast, the point of zero charge was determined to be pH 4.5 by titration techniques, which corresponds to the iso-electric point of between pH 4 and 5 as determined by surface force measurements. Results from kaolinite particle interactions indicate that the silica face--alumina face interaction is dominant for kaolinite particle aggregation at low and intermediate pH values, which explains the maximum shear yield stress at pH 5-5.5. Lattice resolution images reveal the hexagonal lattice structure of these two face surfaces of kaolinite. Analysis of the silica face of kaolinite showed that the center of the hexagonal ring of oxygen atoms is vacant, whereas the alumina face showed that the hexagonal surface lattice ring of hydroxyls surround another hydroxyl in the center of the ring. High resolution transmission electron microscopy investigation of kaolinite has indicated that kaolinite is indeed

  3. Synergistic effect of high charge and energy particle radiation and chronological age on biomarkers of oxidative stress and tissue degeneration: a ground-based study using the vertebrate laboratory model organism Oryzias latipes.

    PubMed

    Zheng, Xuan; Zhang, Xinyan; Ding, Lingling; Lee, Jeffrey R; Weinberger, Paul M; Dynan, William S

    2014-01-01

    High charge and energy (HZE) particles are a main hazard of the space radiation environment. Uncertainty regarding their health effects is a limiting factor in the design of human exploration-class space missions, that is, missions beyond low earth orbit. Previous work has shown that HZE exposure increases cancer risk and elicits other aging-like phenomena in animal models. Here, we investigate how a single exposure to HZE particle radiation, early in life, influences the subsequent age-dependent evolution of oxidative stress and appearance of degenerative tissue changes. Embryos of the laboratory model organism, Oryzias latipes (Japanese medaka fish), were exposed to HZE particle radiation at doses overlapping the range of anticipated human exposure. A separate cohort was exposed to reference γ-radiation. Survival was monitored for 750 days, well beyond the median lifespan. The population was also sampled at intervals and liver tissue was subjected to histological and molecular analysis. HZE particle radiation dose and aging contributed synergistically to accumulation of lipid peroxidation products, which are a marker of chronic oxidative stress. This was mirrored by a decline in PPARGC1A mRNA, which encodes a transcriptional co-activator required for expression of oxidative stress defense genes and for mitochondrial maintenance. Consistent with chronic oxidative stress, mitochondria had an elongated and enlarged ultrastructure. Livers also had distinctive, cystic lesions. Depending on the endpoint, effects of γ-rays in the same dose range were either lesser or not detected. Results provide a quantitative and qualitative framework for understanding relative contributions of HZE particle radiation exposure and aging to chronic oxidative stress and tissue degeneration. PMID:25375139

  4. Synergistic Effect of High Charge and Energy Particle Radiation and Chronological Age on Biomarkers of Oxidative Stress and Tissue Degeneration: A Ground-Based Study Using the Vertebrate Laboratory Model Organism Oryzias latipes

    PubMed Central

    Zheng, Xuan; Zhang, Xinyan; Ding, Lingling; Lee, Jeffrey R.; Weinberger, Paul M.; Dynan, William S.

    2014-01-01

    High charge and energy (HZE) particles are a main hazard of the space radiation environment. Uncertainty regarding their health effects is a limiting factor in the design of human exploration-class space missions, that is, missions beyond low earth orbit. Previous work has shown that HZE exposure increases cancer risk and elicits other aging-like phenomena in animal models. Here, we investigate how a single exposure to HZE particle radiation, early in life, influences the subsequent age-dependent evolution of oxidative stress and appearance of degenerative tissue changes. Embryos of the laboratory model organism, Oryzias latipes (Japanese medaka fish), were exposed to HZE particle radiation at doses overlapping the range of anticipated human exposure. A separate cohort was exposed to reference γ-radiation. Survival was monitored for 750 days, well beyond the median lifespan. The population was also sampled at intervals and liver tissue was subjected to histological and molecular analysis. HZE particle radiation dose and aging contributed synergistically to accumulation of lipid peroxidation products, which are a marker of chronic oxidative stress. This was mirrored by a decline in PPARGC1A mRNA, which encodes a transcriptional co-activator required for expression of oxidative stress defense genes and for mitochondrial maintenance. Consistent with chronic oxidative stress, mitochondria had an elongated and enlarged ultrastructure. Livers also had distinctive, cystic lesions. Depending on the endpoint, effects of γ-rays in the same dose range were either lesser or not detected. Results provide a quantitative and qualitative framework for understanding relative contributions of HZE particle radiation exposure and aging to chronic oxidative stress and tissue degeneration. PMID:25375139

  5. Synergistic Effect of High Charge and Energy Particle Radiation and Chronological Age on Biomarkers of Oxidative Stress and Tissue Degeneration: A Ground-Based Study Using the Vertebrate Laboratory Model Organism Oryzias latipes

    SciTech Connect

    Zheng, Xuan; Zhang, Xinyan; Ding, Lingling; Lee, Jeffrey R.; Weinberger, Paul M.; Dynan, William S.

    2014-11-06

    High charge and energy (HZE) particles are a main hazard of the space radiation environment. Uncertainty regarding their health effects is a limiting factor in the design of human exploration-class space missions, that is, missions beyond low earth orbit. Previous work has shown that HZE exposure increases cancer risk and elicits other aging-like phenomena in animal models. Here, we investigate how a single exposure to HZE particle radiation, early in life, influences the subsequent age-dependent evolution of oxidative stress and appearance of degenerative tissue changes. Embryos of the laboratory model organism, Oryzias latipes (Japanese medaka fish), were exposed to HZE particle radiation at doses overlapping the range of anticipated human exposure. A separate cohort was exposed to reference γ-radiation. Survival was monitored for 750 days, well beyond the median lifespan. The population was also sampled at intervals and liver tissue was subjected to histological and molecular analysis. HZE particle radiation dose and aging contributed synergistically to accumulation of lipid peroxidation products, which are a marker of chronic oxidative stress. This was mirrored by a decline in PPARGC1A mRNA, which encodes a transcriptional co-activator required for expression of oxidative stress defense genes and for mitochondrial maintenance. Consistent with chronic oxidative stress, mitochondria had an elongated and enlarged ultrastructure. Livers also had distinctive, cystic lesions. Depending on the endpoint, effects of γ-rays in the same dose range were either lesser or not detected. Results provide a quantitative and qualitative framework for understanding relative contributions of HZE particle radiation exposure and aging to chronic oxidative stress and tissue degeneration.

  6. Synergistic Effect of High Charge and Energy Particle Radiation and Chronological Age on Biomarkers of Oxidative Stress and Tissue Degeneration: A Ground-Based Study Using the Vertebrate Laboratory Model Organism Oryzias latipes

    DOE PAGESBeta

    Zheng, Xuan; Zhang, Xinyan; Ding, Lingling; Lee, Jeffrey R.; Weinberger, Paul M.; Dynan, William S.

    2014-11-06

    High charge and energy (HZE) particles are a main hazard of the space radiation environment. Uncertainty regarding their health effects is a limiting factor in the design of human exploration-class space missions, that is, missions beyond low earth orbit. Previous work has shown that HZE exposure increases cancer risk and elicits other aging-like phenomena in animal models. Here, we investigate how a single exposure to HZE particle radiation, early in life, influences the subsequent age-dependent evolution of oxidative stress and appearance of degenerative tissue changes. Embryos of the laboratory model organism, Oryzias latipes (Japanese medaka fish), were exposed to HZEmore » particle radiation at doses overlapping the range of anticipated human exposure. A separate cohort was exposed to reference γ-radiation. Survival was monitored for 750 days, well beyond the median lifespan. The population was also sampled at intervals and liver tissue was subjected to histological and molecular analysis. HZE particle radiation dose and aging contributed synergistically to accumulation of lipid peroxidation products, which are a marker of chronic oxidative stress. This was mirrored by a decline in PPARGC1A mRNA, which encodes a transcriptional co-activator required for expression of oxidative stress defense genes and for mitochondrial maintenance. Consistent with chronic oxidative stress, mitochondria had an elongated and enlarged ultrastructure. Livers also had distinctive, cystic lesions. Depending on the endpoint, effects of γ-rays in the same dose range were either lesser or not detected. Results provide a quantitative and qualitative framework for understanding relative contributions of HZE particle radiation exposure and aging to chronic oxidative stress and tissue degeneration.« less

  7. Charged-particle motion in multidimensional magnetic-field turbulence

    NASA Technical Reports Server (NTRS)

    Giacalone, J.; Jokipii, J. R.

    1994-01-01

    We present a new analysis of the fundamental physics of charged-particle motion in a turbulent magnetic field using a numerical simulation. The magnetic field fluctuations are taken to be static and to have a power spectrum which is Kolmogorov. The charged particles are treated as test particles. It is shown that when the field turbulence is independent of one coordinate (i.e., k lies in a plane), the motion of these particles across the magnetic field is essentially zero, as required by theory. Consequently, the only motion across the average magnetic field direction that is allowed is that due to field-line random walk. On the other hand, when a fully three-dimensional realization of the turbulence is considered, the particles readily cross the field. Transport coefficients both along and across the ambient magnetic field are computed. This scheme provides a direct computation of the Fokker-Planck coefficients based on the motions of individual particles, and allows for comparison with analytic theory.

  8. Double charge exchange at high impact energies

    NASA Astrophysics Data System (ADS)

    Belkić, Dževad

    1994-03-01

    In fast ion-atom collisions, double ionization always dominates the two-electron transfer. For this reason, an adequate description of double charge exchange requires proper inclusion of intermediate ionization channels. This is even more important in two- than in one-electron transitions. First-order Born-type perturbation theories ignore throughout these electronic continuum intermediate states and hence provide utterly unreliable high energy cross sections for two-electron capture processes. Therefore, it is essential to use second- and higher-order theories, which include the intermediate ionization continua of the two electrons in an approximate manner. In the present paper, a new second-order theory called the Born distorted wave (BDW) approximation is introduced and implemented in the case of symmetric resonant double electron capture from the ground state of helium by fast alpha particles. A genuine four-body formalism is adopted, in contrast to the conventional independent particle model of atomic scattering theory. The obtained results for the total cross sections are compared with the available experimental data, and satisfactory agreement is recorded. As the incident energy increases, a dramatic improvement is obtained in going from the CB1 to the BDW approximation, since the latter closely follows the measurement, whereas the former overestimates the observed total cross sections by two orders of magnitude. This strongly indicates that the role of continuum intermediate states is decisive, even at those incident energies for which the Thomas double scattering effects are not important. This is in sharp contrast to the case of one-electron transfer atomic reactions.

  9. Energization of Charged Particles By a Time-Dependent Chaotic Magnetic Field

    NASA Astrophysics Data System (ADS)

    Doyle, C. J.; Dasgupta, B.; Heerikhuisen, J.

    2014-12-01

    Energization of particles to ultra high energies remains a challenging problem in the plasma physics community. One possible mechanism involves chaotic magnetic fields. It is noteworthy that the equations describing the spatial evolution of field lines of a magnetic field having dependence on three spatial coordinates are not integrable and such field lines are chaotic. Such chaotic magnetic fields are ubiquitous in nature including many astrophysical scenarios. The motion of charged particles in such magnetic fields comprise an important topic of study since it has been suggested that they may be energized if the field is time-dependent. We considered a particular chaotic field, which is often called the Sine field, and assumed a simple sinusoidal time dependence. Sine fields were first introduced for chaotic fluid motion in the study of nonlinear dynamos, and it can be shown that such fields are a particular solution of the double curl equation for the magnetic field. We construct the equation of motion of a charged particle in the presence of the time-dependent magnetic field and the induced time dependent electric field using Faraday's Law. These three coupled nonlinear differential equations are solved using the adaptive Dormand-Prince Runge-Kutta method. We calculate the energy of the charged particle and examine the evolution of this energy over time. Our results suggest that the energy of the particle increases indefinitely.

  10. Strange particle production in neutrino-neon charged current interactions

    SciTech Connect

    Plano, R.; Baker, N.J.; Connolly, P.L.; Kahn, S.A.; Murtagh, M.J.; Palmer, R.B.; Samios, N.P.; Tanaka, M.; Baltay, C.; Bregman, M.

    1986-01-01

    Neutral strange particle production in charged-current muon-neutrino interactions have been studied in the Fermilab 15-foot neon bubble chamber. Associated production is expected to be the major source of strange particles in charged-current neutrino interactions. sigma-neutral and xi-minus production by neutrinos was observed. The dependence on various leptonic and hadronic variables is investigated. A fit to single and associated production of s, s/anti-s, and c quarks is described based on the number of single and double strange particle production events. Inclusive neutral strange particle decays (V/sup 0/) production rates as a fraction of all charged-current events are measured and are tabulated. The lambda/K ratio is found to be 0.39 +- 0.04 and the fraction of lambda coming from sigma-neutral is (16 +- 5)%. The single- and double V/sup 0/ production was used to determine the associated s anti-s production rate and single s-quark production rate. 13 refs., 7 figs., 3 tabs. (LEW)

  11. Big bang nucleosynthesis with long-lived charged massive particles

    SciTech Connect

    Kohri, Kazunori; Takayama, Fumihiro

    2007-09-15

    We consider big bang nucleosynthesis (BBN) with long-lived charged massive particles. Before decaying, the long-lived charged particle recombines with a light element to form a bound state like a hydrogen atom. This effect modifies the nuclear-reaction rates during the BBN epoch through the modifications of the Coulomb field and the kinematics of the captured light elements, which can change the light element abundances. It is possible for heavier nuclei abundances such as {sup 7}Li and {sup 7}Be to decrease sizably, while the ratios Y{sub p}, D/H, and {sup 3}He/H remain unchanged. This may solve the current discrepancy between the BBN prediction and the observed abundance of {sup 7}Li. If future collider experiments find signals of a long-lived charged particle inside the detector, the information of its lifetime and decay properties could provide insights into not only the particle physics models but also the phenomena in the early Universe, in turn.

  12. Scintillator-fiber charged-particle track-imaging detector

    NASA Technical Reports Server (NTRS)

    Binns, W. R.; Israel, M. H.; Klarmann, J.

    1983-01-01

    A scintillator-fiber charged-particle track-imaging detector has been developed using a bundle of square cross-section plastic scintillator fiber optics, proximity focused onto an image intensified Charge Injection Device (CID) camera. Detector to beams of 15 MeV protons and relativistic Neon, Manganese, and Gold nuclei have been exposed and images of their tracks are obtained. This paper presents details of the detector technique, properties of the tracks obtained, and range measurements of 15 MeV protons stopping in the fiber bundle.

  13. Particle Access and Charging Environments in the Lunar Wake

    NASA Technical Reports Server (NTRS)

    Parker, Linda; Minow, Joseph; Singh, Nagendra; Araveti, Venkata S.; Venkiteswaran, Karthik

    2010-01-01

    A plasma wake a region of low density, high temperature plasma forms on the far side of the Moon when solar wind, magnetosheath, and magnetotail plasma flows past the Moon [Manka, 1973; Ogilvie et al., 1996; Farrell et al., 1998; Halekas et al., 2005]. Ion populations in these flows typically have much smaller thermal velocity than bulk speed and are therefore excluded from the plasma wake while the large thermal electron velocity allows the lighter negatively charged particles to stream ahead of the ions into the wake. Charge separation due to electrons streaming ahead of the ions into the wake from the wake boundary establishes an ambipolar electric field which impedes the motion of electron flow and accelerates ions into the wake [Ogilvie et al., 1996; Farrell et al., 1997]. We have conducted a theoretical study of acceleration (and deceleration) of charged particles in lunar plasma environments, which investigated the mechanisms responsible for allowing solar wind entry into the lunar wake, and for producing energetic particle distributions observed within the lunar wake. To this end, the investigation utilized a macroscale 3D hybrid particle-in-cell numerical model of the interaction of the Moon with external plasma environments to compute electric fields in the lunar environment for a variety of external plasma conditions and interplanetary magnetic field orientations. Ion dynamics were attained from the hybrid code while electron dynamics were determined by considering electron test particle trajectories through the fields established in the hybrid code. Results from the code will be presented to evaluate charging environments within the lunar wake.

  14. Charging of small grains in a space plasma: Application to Jovian stream particles

    NASA Astrophysics Data System (ADS)

    Dzhanoev, A. R.; Schmidt, J.; Liu, X.; Spahn, F.

    2016-07-01

    Context. Most theoretical investigations of dust charging processes in space have treated the current balance condition as independent of grain size. However, for small grains, since they are often observed in space environments, a dependence on grain size is expected owing to secondary electron emission (SEE). Here, by the term "small" we mean a particle size comparable to the typical penetration depth for given primary electron energy. The results are relevant for the dynamics of small, charged dust particles emitted by the volcanic moon Io, which forms the Jovian dust streams. Aims: We revise the theory of charging of small (submicron sized) micrometeoroids to take into account a high production of secondary electrons for small grains immersed in an isotropic flux of electrons. We apply our model to obtain an improved estimate for the charge of the dust streams leaving the Jovian system, detected by several spacecraft. Methods: We apply a continuum model to describe the penetration of primary electrons in a grain and the emission of secondary electrons along the path. Averaging over an isotropic flux of primaries, we derive a new expression for the secondary electron yield, which can be used to express the secondary electron current on a grain. Results: For the Jupiter plasma environment we derive the surface potential of grains composed of NaCl (believed to be the major constituent of Jovian dust stream particles) or silicates. For small particles, the potential depends on grain size and the secondary electron current induces a sensitivity to material properties. As a result of the small particle effect, the estimates for the charging times and for the fractional charge fluctuations of NaCl grains obtained using our general approach to SEE give results qualitatively different from the analogous estimates derived from the traditional approach to SEE. We find that for the charging environment considered in this paper field emission does not limit the charging of

  15. Beams of protons and alpha particles greater than approximately 30 keV/charge from the earth's bow shock

    NASA Technical Reports Server (NTRS)

    Scholer, M.; Ipavich, F. M.; Gloeckler, G.

    1981-01-01

    Two beamlike particle events (30 keV/charge to 160 keV/charge) upstream of the earth's bow shock have been investigated with the Max-Planck-Institut/University of Maryland ultralow energy and charge analyzer on ISEE 1. These beams consist of protons as well as of alpha particles, and the spectra are generally steep and are decreasing with increasing energy. During one event the spectra of both protons and alpha particles have a maximum at approximately 65 keV/charge. During these events, the interplanetary magnetic field through the satellite position was almost tangent to the bow shock, and application of the theory of acceleration predicts acceleration of a solar wind particle up to 60 keV/nucleon in a single reflection. The observation of reflected protons as well as alpha particles has implications for the physical reflection process usually not discussed in acceleration theories.

  16. Double, Rydberg and Charge Transfer Excitations from Pairing Matrix Fluctuation and Particle-Particle Random Phase Approximation

    NASA Astrophysics Data System (ADS)

    Yang, Yang; van Aggelen, Helen; Yang, Weitao

    2014-03-01

    Double, Rydberg and charge transfer (CT) excitations have been great challenges for time-dependent density functional theory (TDDFT). Starting from an (N +/- 2) -electron single-determinant reference, we investigate excitations for the N-electron system through the pairing matrix fluctuation, which contains information on two-electron addition/removal processes. We adopt the particle-particle random phase approximation (pp-RPA) and the particle-particle Tamm-Dancoff approximation (pp-TDA) to approximate the pairing matrix fluctuation and then determine excitation energies by the differences of two-electron addition/removal energies. This approach captures all types of interesting excitations: single and double excitations are described accurately, Rydberg excitations are in good agreement with experimental data and CT excitations display correct 1/R dependence. Furthermore, the pp-RPA and the pp-TDA have a computational cost similar to TDDFT and consequently are promising for practical calculations.

  17. Double, Rydberg and charge transfer excitations from pairing matrix fluctuation and particle-particle random phase approximation

    SciTech Connect

    Yang, Yang; Aggelen, Helen van; Yang, Weitao

    2013-12-14

    Double, Rydberg, and charge transfer (CT) excitations have been great challenges for time-dependent density functional theory (TDDFT). Starting from an (N ± 2)-electron single-determinant reference, we investigate excitations for the N-electron system through the pairing matrix fluctuation, which contains information on two-electron addition/removal processes. We adopt the particle-particle random phase approximation (pp-RPA) and the particle-particle Tamm-Dancoff approximation (pp-TDA) to approximate the pairing matrix fluctuation and then determine excitation energies by the differences of two-electron addition/removal energies. This approach captures all types of interesting excitations: single and double excitations are described accurately, Rydberg excitations are in good agreement with experimental data and CT excitations display correct 1/R dependence. Furthermore, the pp-RPA and the pp-TDA have a computational cost similar to TDDFT and consequently are promising for practical calculations.

  18. Double, Rydberg and charge transfer excitations from pairing matrix fluctuation and particle-particle random phase approximation

    NASA Astrophysics Data System (ADS)

    Yang, Yang; van Aggelen, Helen; Yang, Weitao

    2013-12-01

    Double, Rydberg, and charge transfer (CT) excitations have been great challenges for time-dependent density functional theory (TDDFT). Starting from an (N ± 2)-electron single-determinant reference, we investigate excitations for the N-electron system through the pairing matrix fluctuation, which contains information on two-electron addition/removal processes. We adopt the particle-particle random phase approximation (pp-RPA) and the particle-particle Tamm-Dancoff approximation (pp-TDA) to approximate the pairing matrix fluctuation and then determine excitation energies by the differences of two-electron addition/removal energies. This approach captures all types of interesting excitations: single and double excitations are described accurately, Rydberg excitations are in good agreement with experimental data and CT excitations display correct 1/R dependence. Furthermore, the pp-RPA and the pp-TDA have a computational cost similar to TDDFT and consequently are promising for practical calculations.

  19. Double, Rydberg and charge transfer excitations from pairing matrix fluctuation and particle-particle random phase approximation.

    PubMed

    Yang, Yang; van Aggelen, Helen; Yang, Weitao

    2013-12-14

    Double, Rydberg, and charge transfer (CT) excitations have been great challenges for time-dependent density functional theory (TDDFT). Starting from an (N ± 2)-electron single-determinant reference, we investigate excitations for the N-electron system through the pairing matrix fluctuation, which contains information on two-electron addition/removal processes. We adopt the particle-particle random phase approximation (pp-RPA) and the particle-particle Tamm-Dancoff approximation (pp-TDA) to approximate the pairing matrix fluctuation and then determine excitation energies by the differences of two-electron addition/removal energies. This approach captures all types of interesting excitations: single and double excitations are described accurately, Rydberg excitations are in good agreement with experimental data and CT excitations display correct 1/R dependence. Furthermore, the pp-RPA and the pp-TDA have a computational cost similar to TDDFT and consequently are promising for practical calculations.

  20. Charge and Energy Stored in a Capacitor

    ERIC Educational Resources Information Center

    Kraftmakher, Yaakov

    2012-01-01

    Using a data-acquisition system, the charge and energy stored in a capacitor are measured and displayed during the charging/discharging process. The experiment is usable as a laboratory work and/or a lecture demonstration. (Contains 3 figures.)

  1. Charge collection studies in irradiated HV-CMOS particle detectors

    NASA Astrophysics Data System (ADS)

    Affolder, A.; Andelković, M.; Arndt, K.; Bates, R.; Blue, A.; Bortoletto, D.; Buttar, C.; Caragiulo, P.; Cindro, V.; Das, D.; Dopke, J.; Dragone, A.; Ehrler, F.; Fadeyev, V.; Galloway, Z.; Gorišek, A.; Grabas, H.; Gregor, I. M.; Grenier, P.; Grillo, A.; Hommels, L. B. A.; Huffman, T.; John, J.; Kanisauskas, K.; Kenney, C.; Kramberger, G.; Liang, Z.; Mandić, I.; Maneuski, D.; McMahon, S.; Mikuž, M.; Muenstermann, D.; Nickerson, R.; Perić, I.; Phillips, P.; Plackett, R.; Rubbo, F.; Segal, J.; Seiden, A.; Shipsey, I.; Song, W.; Stanitzki, M.; Su, D.; Tamma, C.; Turchetta, R.; Vigani, L.; Volk, J.; Wang, R.; Warren, M.; Wilson, F.; Worm, S.; Xiu, Q.; Zavrtanik, M.; Zhang, J.; Zhu, H.

    2016-04-01

    Charge collection properties of particle detectors made in HV-CMOS technology were investigated before and after irradiation with reactor neutrons. Two different sensor types were designed and processed in 180 and 350 nm technology by AMS. Edge-TCT and charge collection measurements with electrons from 90Sr source were employed. Diffusion of generated carriers from undepleted substrate contributes significantly to the charge collection before irradiation, while after irradiation the drift contribution prevails as shown by charge measurements at different shaping times. The depleted region at a given bias voltage was found to grow with irradiation in the fluence range of interest for strip detectors at the HL-LHC. This leads to large gains in the measured charge with respect to the one before irradiation. The increase of the depleted region was attributed to removal of effective acceptors. The evolution of depleted region with fluence was investigated and modeled. Initial studies show a small effect of short term annealing on charge collection.

  2. Cataract production in mice by heavy charged particles

    SciTech Connect

    Ainsworth, E.H.; Jose, J.; Yang, V.V.; Barker, M.E.

    1981-03-01

    The cataractogenic effects of heavy charged particles have been evaluated in mice in relation to dose and ionization density (LET/sub infinity/). The study was undertaken due to the high potential for eye exposures to HZE particles among SPS personnel working in outer space. This has made it imperative that the relative biological effectiveness (RBE) in relation to LET/sub infinity/ for various particles be defined so that appropriate quality factors (Q) could be assigned for estimation of risk. Although mice and men differ in susceptibility to radiation-induced cataracts, the results from this project should assist in defining appropriate quality factors in relation to LET/sub infinity/, particle mass, charge, or velocity. Evaluation of results indicated that : (1) low single doses (5 to 20 rad) of iron (/sup 56/Fe) or argon (/sup 40/Ar) particles are cataractogenic at 11 to 18 months after irradiation; (2) onset and density of the opacification are dose related; (3) cataract density (grade) at 9, 11, 13, and 16 months after irradiation shows partial LET/sub infinity/-dependence; and (4) the severity of cataracts is reduced significantly when 417 rad of /sup 60/Co gamma radiation is given in 24 weekly 17 rad fractions compared to giving this radiation as a single dose, but cataract severity is not reduced by fractionation of /sup 12/C doses over 24 weeks.

  3. METHOD AND APPARATUS FOR DETERMINING CHARGED PARTICLE MOTION

    DOEpatents

    Kerns, Q.A.

    1959-08-01

    An analog system for determining the motion of charged particles in three dimensional electrical fields is described. A model electrode structure is formed and potentials are applied to the electrodes to provide an analog of the field which is to be studied. To simulate charged particles within the model, conducting spheres are placed at points from which particle motion is to be traced. To free the spheres from gravitational attraction in order that they will be electrostatically accelerated through the model, the apparatus is suspended and dropped. During the pericd that the model is dropping the spheres move through the electrcde structure with a motion corresponding to that of particles in the real system. The model is photographed in the course of falling so that the instantaneous position of the spheres within the simulated field at selected times may be observed and measured. The device thus gives data of particles in the real system. The model is photographed in the course of falling so that the instantaneous position of the spheres within the simulated field at selected times may be observed and measured. The device thus gives data which frequently can otherwise be obtained only with a digital computer.

  4. Modeling of particle trajectories in an electrostatically charged channel

    NASA Astrophysics Data System (ADS)

    Wu, Mengbai; Kuznetsov, Andrey V.; Jasper, Warren J.

    2010-04-01

    Modeling and analyses of filtration efficiency in electrostatically charged monolith filters are important for evaluating and designing this class of filters. Unlike traditional fibrous filters which comprise external flow around a fiber, monolith filters are modeled as internal flow through small channels. Analogous to single fiber theory for external flows, single channel theory is used to analyze basic fluid mechanics in monolith filters and predict filtration efficiencies. The model incorporates three forces: hydrodynamic forces, electrostatic forces, and Brownian motion. Fluid velocity within the channels is calculated by using an analytical solution for circular channel flow, within which the slip boundary condition is considered because of small length scales. This velocity field is then used to evaluate the drag force on the particle according to Stokes's law. For this model, a one-way coupling between the fluid flow and the particle motion is assumed due to the fact that the relaxation time for the particles simulated in this paper is very small compared to the time the particles spend in the channel. The electrostatic field is computed assuming a uniform charge distribution on the inner surface of a cylindrical channel of finite length. Using a Monte Carlo simulation, particles are randomly injected into a single channel to determine the filtration efficiency.

  5. Radial distribution of charged particles in a magnetic field.

    PubMed

    Sjue, S K L; Broussard, L J; Makela, M; McGaughey, P L; Young, A R; Zeck, B A

    2015-02-01

    The radial spread of charged particles emitted from a point source in a magnetic field is a potential source of systematic error for any experiment where magnetic fields guide charged particles to detectors with finite size. Assuming uniform probability as a function of the phase along the particle's helical trajectory, an analytic solution for the radial probability distribution function follows which applies to experiments in which particles are generated throughout a volume that spans a sufficient length along the axis of a homogeneous magnetic field. This approach leads to the same result as a different derivation given by Dubbers et al., Nucl. Instrum. Methods Phys. Res., Sect. A 763, 112-119 (2014). But the constant phase approximation does not strictly apply to finite source volumes or fixed positions, which lead to local maxima in the radial distribution of emitted particles at the plane of the detector. A simple method is given to calculate such distributions, then the effect is demonstrated with data from a (207)Bi electron-conversion source in the superconducting solenoid magnet spectrometer of the Ultracold Neutron facility at the Los Alamos Neutron Science Center. Implications for neutron beta decay spectroscopy are discussed. PMID:25725818

  6. Transverse-structure electrostatic charged particle beam lens

    DOEpatents

    Moran, Michael J.

    1998-01-01

    Electrostatic particle-beam lenses using a concentric co-planar array of independently biased rings can be advantageous for some applications. Traditional electrostatic lenses often consist of axial series of biased rings, apertures, or tubes. The science of lens design has devoted much attention to finding axial arrangements that compensate for the substantial optical aberrations of the individual elements. Thus, as with multi-element lenses for light, a multi-element charged-particle lens can have optical behavior that is far superior to that of the individual elements. Transverse multiple-concentric-ring lenses achieve high performance, while also having advantages in terms of compactness and optical versatility.

  7. Transverse-structure electrostatic charged particle beam lens

    DOEpatents

    Moran, M.J.

    1998-10-13

    Electrostatic particle-beam lenses using a concentric co-planar array of independently biased rings can be advantageous for some applications. Traditional electrostatic lenses often consist of axial series of biased rings, apertures, or tubes. The science of lens design has devoted much attention to finding axial arrangements that compensate for the substantial optical aberrations of the individual elements. Thus, as with multi-element lenses for light, a multi-element charged-particle lens can have optical behavior that is far superior to that of the individual elements. Transverse multiple-concentric-ring lenses achieve high performance, while also having advantages in terms of compactness and optical versatility. 7 figs.

  8. Trajectories of charged particles trapped in Earth's magnetic field

    NASA Astrophysics Data System (ADS)

    Öztürk, M. Kaan

    2012-05-01

    This article presents the theory of relativistic charged-particle motion in Earth's magnetosphere, at a level suitable for undergraduate courses. I discuss particle and guiding center motion and derive the three adiabatic invariants associated with the three periodic motions in a dipolar field. I provide 12 computational exercises that can be used as classroom assignments or for self-study. Two of the exercises, drift-shell bifurcation and Speiser orbits, are adapted from active magnetospheric research. The PYTHON code provided in the supplement can be used to replicate the trajectories and can be easily extended for different field geometries.

  9. Anisotropy-driven collective instability in intense charged particle beams

    NASA Astrophysics Data System (ADS)

    Startsev, Edward A.; Davidson, Ronald C.; Qin, Hong

    2005-12-01

    The classical electrostatic Harris instability is generalized to the case of a one-component intense charged particle beam with anisotropic temperature including the important effects of finite transverse geometry and beam space charge. For a long, coasting beam, the eigenmode code bEASt have been used to determine detailed 3D stability properties over a wide range of temperature anisotropy and beam intensity. A simple theoretical model is developed which describes the essential features of the linear stage of the instability. Both the simulations and the analytical theory clearly show that moderately intense beams are linearly unstable to short-wavelength perturbations provided the ratio of the longitudinal temperature to the transverse temperature is smaller than some threshold value. The delta-f particle-in-cell code BEST has been used to study the detailed nonlinear evolution and saturation of the instability.

  10. Peak polarity overturn for charged particles in laser ablation process

    SciTech Connect

    Zhang, P.; Ji, Y. J.; Lai, X. M.; Bian, B. M.; Li, Z. H.

    2006-07-01

    The charged particles emitted during laser ablation off a brass target are detected using a metal probe in air. A special phenomenon is found in the recorded signals: following a giant electromagnetic peak observed immediately after the emission of the pulsed laser, a minor peak occurs whose polarity merely depends on the distance between the probe and the laser focal spot on the target. Under the condition of our experiment, the overturn point is 1.47 mm, i.e., the minor peak remains negative when the probe distance is less than 1.47 mm; it becomes positive while the probe is set at a distance beyond 1.47 mm. A hypothesis is proposed to explain the overturn that takes the flight behavior of the charged particles both in plasma and propagating shock wave into consideration.

  11. Paul trapping of charged particles in aqueous solution

    PubMed Central

    Guan, Weihua; Joseph, Sony; Park, Jae Hyun; Krstić, Predrag S.; Reed, Mark A.

    2011-01-01

    We experimentally demonstrate the feasibility of an aqueous Paul trap using a proof-of-principle planar device. Radio frequency voltages are used to generate an alternating focusing/defocusing potential well in two orthogonal directions. Individual charged particles are dynamically confined into nanometer scale in space. Compared with conventional Paul traps working in frictionless vacuum, the aqueous environment associated with damping forces and thermally induced fluctuations (Brownian noise) exerts a fundamental influence on the underlying physics. We investigate the impact of these two effects on the confining dynamics, with the aim to reduce the rms value of the positional fluctuations. We find that the rms fluctuations can be modulated by adjusting the voltages and frequencies. This technique provides an alternative for the localization and control of charged particles in an aqueous environment. PMID:21606331

  12. First- and second-order charged particle optics

    SciTech Connect

    Brown, K.L.; Servranckx, R.V.

    1984-07-01

    Since the invention of the alternating gradient principle there has been a rapid evolution of the mathematics and physics techniques applicable to charged particle optics. In this publication we derive a differential equation and a matrix algebra formalism valid to second-order to present the basic principles governing the design of charged particle beam transport systems. A notation first introduced by John Streib is used to convey the essential principles dictating the design of such beam transport systems. For example the momentum dispersion, the momentum resolution, and all second-order aberrations are expressed as simple integrals of the first-order trajectories (matrix elements) and of the magnetic field parameters (multipole components) characterizing the system. 16 references, 30 figures.

  13. Paul trapping of charged particles in aqueous solution.

    PubMed

    Guan, Weihua; Joseph, Sony; Park, Jae Hyun; Krstic, Predrag S; Reed, Mark A

    2011-06-01

    We experimentally demonstrate the feasibility of an aqueous Paul trap using a proof-of-principle planar device. Radio frequency voltages are used to generate an alternating focusing/defocusing potential well in two orthogonal directions. Individual charged particles are dynamically confined into nanometer scale in space. Compared with conventional Paul traps working in frictionless vacuum, the aqueous environment associated with damping forces and thermally induced fluctuations (Brownian noise) exerts a fundamental influence on the underlying physics. We investigate the impact of these two effects on the confining dynamics, with the aim to reduce the rms value of the positional fluctuations. We find that the rms fluctuations can be modulated by adjusting the voltages and frequencies. This technique provides an alternative for the localization and control of charged particles in an aqueous environment.

  14. Calculation of dose contributions of electron and charged heavy particles inside phantoms irradiated by monoenergetic neutron.

    PubMed

    Satoh, Daiki; Takahashi, Fumiaki; Endo, Akira; Ohmachi, Yasushi; Miyahara, Nobuyuki

    2008-09-01

    The radiation-transport code PHITS with an event generator mode has been applied to analyze energy depositions of electrons and charged heavy particles in two spherical phantoms and a voxel-based mouse phantom upon neutron irradiation. The calculations using the spherical phantoms quantitatively clarified the type and energy of charged particles which are released through interactions of neutrons with the phantom elements and contribute to the radiation dose. The relative contribution of electrons increased with an increase in the size of the phantom and with a decrease in the energy of the incident neutrons. Calculations with the voxel-based mouse phantom for 2.0-MeV neutron irradiation revealed that the doses to different locations inside the body are uniform, and that the energy is mainly deposited by recoil protons. The present study has demonstrated that analysis using PHITS can yield dose distributions that are accurate enough for RBE evaluation. PMID:18580044

  15. Particle production at collider energies

    SciTech Connect

    Geich-Gimbel, C. )

    1989-01-01

    High energy particle physics, which has been trying to understand and to devise new laws governing nature at per particle energies far beyond everyday energies, has entered a new episode. Having surpassed the low energy regime, where (s channel) resonance production dominantly projects onto the final state, very interesting features of the strong interaction arose at c.m. energies in the tens of GEV range, as found at the CERN Intersecting Storage Rings (ISR). One recalls the onset of hard scattering processes, which was understood as a scattering between constituents of the nucleon, hence supporting the Quark Parton Model (QPM). Surprisingly enough the total cross section started to rise again, when it was initially believed to have reached a constant value, suggesting an asymptotia. Furthermore correlations among the final state particles produced were observed, and especially long range correlations, which must reflect dynamical laws.

  16. Reconstruction of charged particle fluxes detected by the Radiation Assessment Detector onboard of MSL

    NASA Astrophysics Data System (ADS)

    Guo, J.; Wimmer-Schweingruber, R. F.; Hassler, D.; Zeitlin, C. J.; Ehresmann, B.; Kohler, J.; Boehm, E.; Appel, J. K.; Lohf, H.; Boettcher, S.; Burmeister, S.; Rafkin, S. C.; Kharytonov, A.; Martin-Garcia, C.; Matthiae, D.; Reitz, G.

    2013-12-01

    One of the main science objectives of the Mars Science Laboratory (MSL) is to help planning future human exploration to Mars by constraining the radiation environment during the cruise phase and on the planet's surface. During the 253-day, 560 million km cruise to Mars, the Radiation Assessment Detector, RAD made detailed measurements of the energy spectrum deposited by energetic particles from space and scattered within the spacecraft. Two types of radiation pose potential health risks to astronauts in deep space: a prolonged low-dose exposure to Galactic Cosmic Rays (GCRs) and short-term exposures to the Solar Energetic Particles (SEPs). On the surface of Mars such energetic particles penetrate through its thin atmosphere and generate secondary particles that can also result harms to humans. In order to interpret the energetic charged particle flux coming into the detector, we have developed the Detector Response Function (DRF) using GEANT 4 simulations and employed a Maximum likelihood inversion technique to invert the detected energy spectrum. This method has been applied to RAD detection of GCRs and secondary charged particles on the Martian surface, giving us an unique insight into their energy fluxes. The spectra of the stopping particle fluxes (hydrogen and helium) are also directly obtained from RAD observations and compared with the inversion results.

  17. Charged particle identification with modules of the plastic ball

    SciTech Connect

    Gutbrod, H.H.; Maier, M.R.; Ritter, H.G.; Warwick, A.I.; Weik, F.; Wieman, H.; Wolf, K.L.

    1980-10-01

    The low energy pion channel (LEP) at LAMPF was used to calibrate the response of modules of the Plastic Ball detector for positive pions and protons. The detection efficiency was measured at various energies. The resolution and efficiency were found to be independent of the point at which the particle entered the detector. Scattered out particles could be well detected by including neighbouring detectors in the analysis.

  18. Charged particle detectors made from thin layers of amorphous silicon

    SciTech Connect

    Morel, J.R.

    1986-05-01

    A series of experiments was conducted to determine the feasibility of using hydrogenated amorphous silicon (..cap alpha..-Si:H) as solid state thin film charged particle detectors. /sup 241/Am alphas were successfully detected with ..cap alpha..-Si:H devices. The measurements and results of these experiments are presented. The problems encountered and changes in the fabrication of the detectors that may improve the performance are discussed.

  19. Charged particle track reconstruction using artificial neural networks

    SciTech Connect

    Glover, C.; Fu, P.; Gabriel, T. ); Handler, T. . Dept. of Physics)

    1992-01-01

    This paper summarizes the current state of our research in developing and applying artificial neural network (ANN) algorithm described here is based on a crude model of the retina. It takes as input the coordinates of each charged particle's interaction point ( hit'') in the tracking chamber. The algorithm's output is a set of vectors pointing to other hits that most likely to form a track.

  20. Motion of charged particles in planetary magnetospheres with nonelectromagnetic forces

    NASA Technical Reports Server (NTRS)

    Huang, T. S.; Hill, T. W.; Wolf, R. A.

    1988-01-01

    Expressions are derived for the mirror point, the bounce period, the second adiabatic invariant, and the bounce-averaged azimuthal drift velocity as functions of equatorial pitch angle for a charged particle in a dipole magnetic field in the presence of centrifugal, gravitational, and Coriolis forces. These expressions are evaluated numerically, and the results are displayed graphically. The average azimuthal drift speed for a flux tube containing a thermal equilibrium plasma distribution is also evaluated.

  1. Monolayers of charged particles in a Langmuir trough: Could particle aggregation increase the surface pressure?

    PubMed

    Petkov, Plamen V; Danov, Krassimir D; Kralchevsky, Peter A

    2016-01-15

    The effect of aggregation on the surface pressure, Π, of monolayers from charged micrometer-sized colloidal particles on the air/water interface is investigated. Π is completely due to the long-range electrostatic repulsion between the particles mediated by their electrostatic field in the air. The most probable origin of particle aggregation is the attraction between capillary quadrupoles due to undulated contact lines on particle surfaces. Aggregates have higher charge and repel each other stronger than single particles. The data analysis by means of a theoretical model implies that Π linearly increases with n(1/2); n is the mean aggregation number, which can be determined from the experimental Π vs. area curves. The presence of electrolyte promotes aggregation, which tends to increase Π, but simultaneously reduces the surface charge that leads to lower Π. For our system, the first effect prevails and apparently paradoxical behavior is observed: the addition of salt in water enhances the electrostatic surface pressure. The data indicate limited aggregation: the rise of the electrostatic barrier prevents the further coalescence of aggregates if they have become sufficiently large. The results contribute for a better understanding of the factors that control the interactions in monolayers of charged particles at liquid interfaces.

  2. Energy storage device with large charge separation

    DOEpatents

    Holme, Timothy P.; Prinz, Friedrich B.; Iancu, Andrei

    2016-04-12

    High density energy storage in semiconductor devices is provided. There are two main aspects of the present approach. The first aspect is to provide high density energy storage in semiconductor devices based on formation of a plasma in the semiconductor. The second aspect is to provide high density energy storage based on charge separation in a p-n junction.

  3. Probing new physics with long-lived charged particles produced by atmospheric and astrophysical neutrinos

    SciTech Connect

    Ando, Shin'ichiro; Profumo, Stefano; Beacom, John F; Rainwater, David E-mail: beacom@mps.ohio-state.edu E-mail: rain@pas.rochester.edu

    2008-04-15

    As suggested by some extensions of the standard model of particle physics, dark matter may be a super-weakly-interacting lightest stable particle, while the next-to-lightest particle (NLP) is charged and metastable. One could test such a possibility with neutrino telescopes, by detecting the charged NLPs produced in high-energy neutrino collisions with Earth matter. We study the production of charged NLPs by both atmospheric and astrophysical neutrinos; only the latter, which is largely uncertain and has not been detected yet, was the focus of previous studies. We compute the resulting fluxes of the charged NLPs, compare those of different origins and analyze the dependence on the underlying particle physics set-up. We point out that, even if the astrophysical neutrino flux is very small, atmospheric neutrinos, especially those from the prompt decay of charmed mesons, may provide a detectable flux of NLP pairs at neutrino telescopes such as IceCube. We also comment on the flux of charged NLPs expected from proton-nucleon collisions and show that, for theoretically motivated and phenomenologically viable models, it is typically subdominant and below detectable rates.

  4. Probing new physics with long-lived charged particles produced by atmospheric and astrophysical neutrinos

    NASA Astrophysics Data System (ADS)

    Ando, Shin'ichiro; Beacom, John F.; Profumo, Stefano; Rainwater, David

    2008-04-01

    As suggested by some extensions of the standard model of particle physics, dark matter may be a super-weakly-interacting lightest stable particle, while the next-to-lightest particle (NLP) is charged and metastable. One could test such a possibility with neutrino telescopes, by detecting the charged NLPs produced in high-energy neutrino collisions with Earth matter. We study the production of charged NLPs by both atmospheric and astrophysical neutrinos; only the latter, which is largely uncertain and has not been detected yet, was the focus of previous studies. We compute the resulting fluxes of the charged NLPs, compare those of different origins and analyze the dependence on the underlying particle physics set-up. We point out that, even if the astrophysical neutrino flux is very small, atmospheric neutrinos, especially those from the prompt decay of charmed mesons, may provide a detectable flux of NLP pairs at neutrino telescopes such as IceCube. We also comment on the flux of charged NLPs expected from proton-nucleon collisions and show that, for theoretically motivated and phenomenologically viable models, it is typically subdominant and below detectable rates.

  5. The Effect of Aerodynamic Heating on Air Penetration by Shaped Charge Jets and Their Particles

    NASA Astrophysics Data System (ADS)

    Backofen, Joseph

    2009-06-01

    The goal of this paper is to present recent work modeling thermal coupling between shaped charge jets and their particles with air while it is being penetrated to form a crater that subsequently collapses back onto the jet. This work complements research published at International Symposia on Ballistics: 1) 1987 - Shaped Charge Jet Aerodynamics, Particulation and Blast Field Modeling; and 2) 2007 - Air Cratering by Eroding Shaped Charge Jets. The current work shows how and when a shaped charge jet's tip and jet particles are softened enough that they can erode in a hydrodynamic manner as modeled in these papers. This paper and its presentation includes models for heat transfer from shocked air as a function of jet velocity as well as heat flow within the jet or particle. The work is supported by an extensive bibliographic search including publications on meteors and ballistic missile re-entry vehicles. The modeling shows that a jet loses its strength to the depth required to justify hydrodynamic erosion when its velocity is above a specific velocity related to the shock properties of air and the jet material's properties. As a result, the portion of a jet's kinetic energy converted at the aerodynamic shock into heating transferred back onto the jet affects the energy deposited into the air through drag and ablation which in turn affect air crater expansion and subsequent collapse back onto the jet and its particles as shown in high-speed photography.

  6. A numerical study on charged-particle scattering and radiography of a steep density gradient

    NASA Astrophysics Data System (ADS)

    Shao, Guangchao; Wang, Xiaofang

    2016-09-01

    Electron and proton radiography of polystyrene planar targets with different density gradients is studied by Monte Carlo simulations in a regime that the incident charged-particle's kinetic energy is much higher than its energy loss in the targets. It is shown that by scattering of the electrons or protons, the density gradient causes modulations of the charged-particle beam transmitted from the target and the modulation contrast is sensitive only to a steep gradient, which suggests a novel diagnostic method wherein a steep density gradient could be distinguished from the scattering of a charged-particle beam in radiography. By using a 100-MeV charged-particle beam, it is found that the modulation is evident for a steep density gradient of width smaller than 1 μm for electron radiography and 0.6 μm for proton radiography, respectively, but almost negligible when the density gradient width is greater than 1 μm. The feasibility of diagnosing the steep density gradients in compressed matter is confirmed by the simulations of radiographing a laser-ablated planar foil. Simulations also show that it is possible to diagnose the density gradients inside a multilayered spherical capsule.

  7. Improved search for elementary particles with fractional electric charge

    SciTech Connect

    Mar, N.M.; Lee, E.R.; Fleming, G.R.; Casey, B.C.; Perl, M.L.; Garwin, E.L.; Hendricks, C.D.; Lackner, K.S.; Shaw, G.L.

    1996-06-01

    We have devised and demonstrated the successful operation of a low-cost, high-mass throughput technique capable of performing bulk matter searches for fractionally charged particles based on an improved Millikan liquid drop method. The method uses a stroboscopic lamp and a charge coupled device video camera to image the trajectories of silicone oil drops falling through air in the presence of a vertical, alternating electric field. The images of the trajectories are computer processed in real time, the electric charge on a drop being measured with an rms error of 0.025 of an electron charge. This error is dominated by Brownian motion. In the first use of this method, we have looked at 5974941 drops and found no evidence for fractional charges in 1.07 mg of oil. With 95{percent} confidence, the concentration of isolated quarks with {plus_minus}1/3{ital e} or {plus_minus}2/3{ital e} in silicone oil is less than one per 2.14{times}10{sup 20} nucleons. {copyright} {ital 1996 The American Physical Society.}

  8. Human fibrinogen adsorption on positively charged latex particles.

    PubMed

    Zeliszewska, Paulina; Bratek-Skicki, Anna; Adamczyk, Zbigniew; Cieśla, Michał

    2014-09-23

    Fibrinogen (Fb) adsorption on positively charged latex particles (average diameter of 800 nm) was studied using the microelectrophoretic and the concentration depletion methods based on AFM imaging. Monolayers on latex were adsorbed from diluted bulk solutions at pH 7.4 and an ionic strength in the range of 10(-3) to 0.15 M where fibrinogen molecules exhibited an average negative charge. The electrophoretic mobility of the latex after controlled fibrinogen adsorption was systematically measured. A monotonic decrease in the electrophoretic mobility of fibrinogen-covered latex was observed for all ionic strengths. The results of these experiments were interpreted according to the three-dimensional electrokinetic model. It was also determined using the concentration depletion method that fibrinogen adsorption was irreversible and the maximum coverage was equal to 0.6 mg m(-2) for ionic strength 10(-3) M and 1.3 mg m(-2) for ionic strength 0.15 M. The increase of the maximum coverage was confirmed by theoretical modeling based on the random sequential adsorption approach. Paradoxically, the maximum coverage of fibrinogen on positively charged latex particles was more than two times lower than the maximum coverage obtained for negative latex particles (3.2 mg m(-2)) at pH 7.4 and ionic strength of 0.15 M. This was interpreted as a result of the side-on adsorption of fibrinogen molecules with their negatively charged core attached to the positively charged latex surface. The stability and acid base properties of fibrinogen monolayers on latex were also determined in pH cycling experiments where it was observed that there were no irreversible conformational changes in the fibrinogen monolayers. Additionally, the zeta potential of monolayers was more positive than the zeta potential of fibrinogen in the bulk, which proves a heterogeneous charge distribution. These experimental data reveal a new, side-on adsorption mechanism of fibrinogen on positively charged surfaces and

  9. Radial distribution of charged particles in a magnetic field

    SciTech Connect

    Sjue, S. K. L. Broussard, L. J.; Makela, M.; McGaughey, P. L.; Young, A. R.; Zeck, B. A.

    2015-02-15

    The radial spread of charged particles emitted from a point source in a magnetic field is a potential source of systematic error for any experiment where magnetic fields guide charged particles to detectors with finite size. Assuming uniform probability as a function of the phase along the particle’s helical trajectory, an analytic solution for the radial probability distribution function follows which applies to experiments in which particles are generated throughout a volume that spans a sufficient length along the axis of a homogeneous magnetic field. This approach leads to the same result as a different derivation given by Dubbers et al., Nucl. Instrum. Methods Phys. Res., Sect. A 763, 112–119 (2014). But the constant phase approximation does not strictly apply to finite source volumes or fixed positions, which lead to local maxima in the radial distribution of emitted particles at the plane of the detector. A simple method is given to calculate such distributions, then the effect is demonstrated with data from a {sup 207}Bi electron-conversion source in the superconducting solenoid magnet spectrometer of the Ultracold Neutron facility at the Los Alamos Neutron Science Center. Implications for neutron beta decay spectroscopy are discussed.

  10. Energy extremum principle for charged black holes

    NASA Astrophysics Data System (ADS)

    Fraser, Scott; Funkhouser, Shaker Von Price

    2015-11-01

    For a set of N asymptotically flat black holes with arbitrary charges and masses, all initially at rest and well separated, we prove the following extremum principle: the extremal charge configuration (|qi|=mi for each black hole) can be derived by extremizing the total energy, for variations of the black hole apparent horizon areas, at fixed charges and fixed Euclidean separations. We prove this result through second order in an expansion in the inverse separations. If all charges have the same sign, this result is a variational principle that reinterprets the static equilibrium of the Majumdar-Papapetrou-Hartle-Hawking solution as an extremum of total energy, rather than as a balance of forces; this result augments a list of related variational principles for other static black holes, and is consistent with the independently known Bogomol'nyi-Prasad-Sommerfield (BPS) energy minimum.

  11. Effective atomic number, energy loss and radiation damage studies in some materials commonly used in nuclear applications for heavy charged particles such as H, C, Mg, Fe, Te, Pb and U

    NASA Astrophysics Data System (ADS)

    Kurudirek, Murat

    2016-05-01

    Commonly used nuclear physics materials such as water, concrete, Pb-glass, paraffin, freon and P 10 gases, some alloys such as brass, bronze, stainless-steel and some scintillators such as anthracene, stilbene and toluene have been investigated with respect to the heavy charged particle interaction as means of projected range and effective atomic number (Zeff) in the energy region 10 keV to 10 MeV. Calculations were performed for heavy ions such as H, C, Mg, Fe, Te, Pb and U. Also, the energy loss and radiation damage were studied using SRIM Monte Carlo code for anthracene for different heavy ions of 100 keV kinetic energy. It has been observed that the variation in Zeff becomes less when the atomic number of the ions increase. Glass-Pb, bronze, brass, stainless-steel and Freon gas were found to vary less than 10% in the energy region 10 keV to 10 MeV. For total proton interaction, discrepancies up to 10% and 18% between two databases namely PSTAR and SRIM were noted in mass stopping power and Zeff of water, respectively. The range calculations resulted with a conclusion that the metal alloys and glass-Pb have lowest values of ranges confirming best shielding against energetic heavy ions whereas freon and P 10 gases have the highest values of ranges in the entire energy region. The simulation results showed that the energy loss (%) to target electrons decreases as the Z of the incident ion increases. Also, it was observed that the radiation damage first increases with Z of the ion and then keeps almost constant for ions with Z≥52.

  12. Electrostatic Charging of Polymers by Particle Impact at Low Pressures

    NASA Technical Reports Server (NTRS)

    Calle, Carlos I.; Mantovani, J. G.; Buhler, C. R.; Hogue, M. D.; Nowicki, A. W.; Groop, E. E.; Thompson, Karen (Technical Monitor)

    2001-01-01

    Studies of the electrostatic interaction between micrometer-sized particles and polymer surfaces are of great interest to NASA's planetary exploration program. The unmanned landing missions to Mars planned for this decade as well as the possible manned missions that might take place during the second decade of this century require a better understanding of the electrostatic response of the materials used in landing crafts and equipment when exposed to wind-blown dust or to surface dust and sand particles. We report on preliminary experiments designed to measure the electrostatic charge developed on five polymer surfaces as they are impacted simultaneously by Mars simulant particles less than 5 micrometers in diameter moving at 20 m/s. Experiments were performed in a CO2 atmosphere at 10 mbars of pressure using a particle delivery method that propels the particles with contact. Experiments were also performed in dry air at atmospheric pressures using a pressurized particle delivery system. The five polymer surfaces, commonly used in space applications, were chosen so that they span the triboelectric series.

  13. Coherent Light induced in Optical Fiber by a Charged Particle

    NASA Astrophysics Data System (ADS)

    Artru, Xavier; Ray, Cédric

    2016-07-01

    Coherent light production in an optical fiber by a charged particle (named PIGL, for particle-induced guided, light) is reviewed. From the microscopic point of view, light is emitted by transient electric dipoles induced in the fiber medium by the Coulomb field of the particle. The phenomenon can also considered as the capture of virtual photons of the particle field by the fiber. Two types of captures are distinguished. Type-I takes place in a uniform part of the fiber; then the photon keeps its longitudinal momentum pz . Type-II takes place near an end or in a non-uniform part of the fiber; then pz is not conserved. Type-I PIGL is not affected by background lights external to the fiber. At grazing incidence it becomes nearly monochromatic. Its circular polarization depends on the angular momentum of the particle about the fiber and on the relative velocity between the particle and the guided wave. A general formula for the yield of Type-II radiation, based on the reciprocity theorem, is proposed. This radiation can be assisted by metallic objects stuck to the fiber, via plasmon excitation. A periodic structure leads to a guided Smith-Purcell radiation. Applications of PIGL in beam diagnostics are considered.

  14. Light Charged Particle Emission and the Giant Dipole Resonance in Ce Nucleus

    NASA Astrophysics Data System (ADS)

    Gramegna, F.; Barlini, S.; Kravchuk, V. L.; Lanchais, A. L.; Wieland, O.; Bracco, A.; Moroni, A.; Casini, G.; Benzoni, G.; Blasi, N.; Brambilla, S.; Brekiesz, M.; Bruno, M.; Camera, F.; Chiari, M.; Crespi, F.; Geraci, E.; Guiot, B.; Kmiecik, M.; Leoni, S.; Maj, A.; Mastinu, P. F.; Million, B.; Nannini, A.; Ordine, A.; Vannini, G.

    2005-04-01

    The 132Ce compound nucleus was formed in fusion reactions 64Ni + 68Zn and 16O + 116Sn at different excitation energies. High energy γ -rays have been measured in coincidence with Evaporation Residues (ER) in these reactions. At the same time Light Charged Particles (LCP) were measured with the same gate on ER for all the reactions in order to verify and compare the amount of pre-equilibrium emission using mass-symmetric and mass-asymmetric entrance channels. Results on α -particle spectra will be presented together with a moving source fit analysis.

  15. Stable charged-particle acceleration and focusing in a laser accelerator using spatial harmonics.

    PubMed

    Naranjo, B; Valloni, A; Putterman, S; Rosenzweig, J B

    2012-10-19

    Regarding the laser-driven acceleration of charged particles in photonic systems, a central unmet challenge is the achievement of simultaneous transverse and longitudinal stability at nonultrarelativistic energies. At such energies, Earnshaw's theorem [S. Earnshaw, Trans. Cambridge Philos. Soc. 7, 97 (1842)] indicates that a synchronous accelerating wave gives a defocusing effect. We present a scheme in which particles are accelerated by interaction with a resonant spatial harmonic and are focused by strong ponderomotive interaction with nonresonant spatial harmonics. We show that this scheme exhibits net transverse focusing and longitudinal stability, and we discuss its use in a compact laser accelerator.

  16. Inclusive charged particle distribution in nearly 3-fold symmetric 3-jet events at E/sub cm/ = 29 GeV

    SciTech Connect

    Petersen, A.

    1986-04-01

    Results of inclusive charged particle distribution for gluon jets using nearly 3-fold symmetric 3-jet events taken at center of mass energies of 29 GeV in e/sup +/e/sup -/ annihilation are presented. The charged particle spectrum for these jets is observed to be softer than that of quark jets with the same jet energy.

  17. Anomaly and the self-energy of electric charges

    NASA Astrophysics Data System (ADS)

    Frolov, Valeri P.; Zelnikov, Andrei

    2012-11-01

    We study the self-energy of a charged particle located in a static D-dimensional gravitational field. We show that the energy functional for this problem is invariant under an infinite dimensional (gauge) group of transformations parametrized by one scalar function of (D-1)—variables. We demonstrate that the problem of the calculation of the self-energy for a pointlike charge is equivalent to the calculation of the fluctuations ⟨ψ2⟩ for an effective (D-1)—dimensional Euclidean quantum field theory. Using point-splitting regularization we obtain an expression for the self-energy and show that it possesses anomalies. Explicit calculation of the self-energy and its anomaly is done for the higher dimensional Majumdar-Papapetrou spacetimes.

  18. A Generalized Boltzmann Fokker-Planck Method for Coupled Charged Particle Transport

    SciTech Connect

    Prinja, Anil K

    2012-01-09

    The goal of this project was to develop and investigate the performance of reduced-physics formulations of high energy charged particle (electrons, protons and heavier ions) transport that are computationally more efficient than not only analog Monte Carlo methods but also the established condensed history Monte Carlo technique. Charged particles interact with matter by Coulomb collisions with target nuclei and electrons, by bremsstrahlung radiation loss and by nuclear reactions such as spallation and fission. Of these, inelastic electronic collisions and elastic nuclear collisions are the dominant cause of energy-loss straggling and angular deflection or range straggling of a primary particle. These collisions are characterized by extremely short mean free paths (sub-microns) and highly peaked, near-singular differential cross sections about forward directions and zero energy loss, with the situation for protons and heavier ions more extreme than for electrons. For this reason, analog or truephysics single-event Monte Carlo simulation, while possible in principle, is computationally prohibitive for routine calculation of charged particle interaction phenomena.

  19. Energetic Charged-Particle Phenomena in the Jovian Magnetosphere: First Results from the Ulysses COSPIN Collaboration.

    PubMed

    Simpson, J A; Anglin, J D; Balogh, A; Burrows, J R; Cowley, S W; Ferrando, P; Heber, B; Hynds, R J; Kunow, H; Marsden, R G; McKibben, R B; Müller-Mellin, R; Page, D E; Raviart, A; Sanderson, T R; Staines, K; Wenzel, K P; Wilson, M D; Zhang, M

    1992-09-11

    The Ulysses spacecraft made the first exploration of the region of Jupiter's magnetosphere at high Jovigraphic latitudes ( approximately 37 degrees south) on the dusk side and reached higher magnetic latitudes ( approximately 49 degrees north) on the day side than any previous mission to Jupiter. The cosmic and solar particle investigations (COSPIN) instrumentation achieved a remarkably well integrated set of observations of energetic charged particles in the energy ranges of approximately 1 to 170 megaelectron volts for electrons and 0.3 to 20 megaelectron volts for protons and heavier nuclei. The new findings include (i) an apparent polar cap region in the northern hemisphere in which energetic charged particles following Jovian magnetic field lines may have direct access to the interplanetary medium, (ii) high-energy electron bursts (rise times energies extending to > approximately 17 megaelectron volts) on the dusk side that are apparently associated with field-aligned currents and radio burst emissions, (iii) persistence of the global 10-hour relativistic electron "clock" phenomenon throughout Jupiter's magnetosphere, (iv) on the basis of charged-particle measurements, apparent dragging of magnetic field lines at large radii in the dusk sector toward the tail, and (v) consistent outflow of megaelectron volt electrons and large-scale departures from corotation for nucleons.

  20. Charged Particle Motion in AN Explosively Generated Ionizing Shock

    NASA Astrophysics Data System (ADS)

    Boswell, Christopher J.; O'Connor, Patrick D.

    2009-12-01

    Different aspects of the plasma generated in a gas contained in a tube due to detonation of a small explosive charge located at one end of the tube are presented. The motion of the charged particles within the plasma is monitored using Rogowski coils. Using time-resolved emission spectroscopy the temperature and species in the detonation products and compressed gas behind the shock wave are recorded. From the spectral lines of the emission profiles the temperatures and electron density were evaluated to be in the vicinity of 7,000 K and 5×1022 m-3. An ultra fast wave traveling down the guide tube ahead of the hydrodynamic shock and causing any charged particles there to move fast enough to be detected by the Rogowski coils was recorded. From the measurements the phase velocity of the wave was calculated at 525 km/s when krypton filled the tube, and 1300 km/s in the case of argon. The temperature and density measurements are consistent with the data reported in the literature for similar tests. The electrostatic pulse measurements are a new phenomena not previously observed.

  1. Pacemakers charging using body energy.

    PubMed

    Bhatia, Dinesh; Bairagi, Sweeti; Goel, Sanat; Jangra, Manoj

    2010-01-01

    Life-saving medical implants like pacemakers and defibrillators face a big drawback that their batteries eventually run out and patients require frequent surgery to have these batteries replaced. With the advent of technology, alternatives can be provided for such surgeries. To power these devices, body energy harvesting techniques may be employed. Some of the power sources are patient's heartbeat, blood flow inside the vessels, movement of the body parts, and the body temperature (heat). Different types of sensors are employed, such as for sensing the energy from the heartbeat the piezoelectric and semiconducting coupled nanowires are used that convert the mechanical energy into electricity. Similarly, for sensing the blood flow energy, nanogenerators driven by ultrasonic waves are used that have the ability to directly convert the hydraulic energy in human body to electrical energy. Another consideration is to use body heat employing biothermal battery to generate electricity using multiple arrays of thermoelectric generators built into an implantable chip. These generators exploit the well-known thermocouple effect. For the biothermal device to work, it needs a 2°C temperature difference across it. But there are many parts of the body where a temperature difference of 5°C exists - typically in the few millimeters just below the skin, where it is planned to place this device. This study focuses on using body heat as an alternative energy source to recharge pacemaker batteries and other medical devices and prevent the possibility of life-risk during repeated surgery.

  2. Electromagnetic fields and potentials generated by massless charged particles

    SciTech Connect

    Azzurli, Francesco; Lechner, Kurt

    2014-10-15

    We provide for the first time the exact solution of Maxwell’s equations for a massless charged particle moving on a generic trajectory at the speed of light. In particular we furnish explicit expressions for the vector potential and the electromagnetic field, which were both previously unknown, finding that they entail different physical features for bounded and unbounded trajectories. With respect to the standard Liénard–Wiechert field the electromagnetic field acquires singular δ-like contributions whose support and dimensionality depend crucially on whether the motion is (a) linear, (b) accelerated unbounded, (c) accelerated bounded. In the first two cases the particle generates a planar shock-wave-like electromagnetic field traveling along a straight line. In the second and third cases the field acquires, in addition, a δ-like contribution supported on a physical singularity-string attached to the particle. For generic accelerated motions a genuine radiation field is also present, represented by a regular principal-part type distribution diverging on the same singularity-string. - Highlights: • First exact solution of Maxwell’s equations for massless charges in arbitrary motion. • Explicit expressions of electromagnetic fields and potentials. • Derivations are rigorous and based on distribution theory. • The form of the field depends heavily on whether the motion is bounded or unbounded. • The electromagnetic field contains unexpected Dirac-delta-function contributions.

  3. Analysis of LEAM experiment response to charged particles

    NASA Technical Reports Server (NTRS)

    Perkins, D.

    1976-01-01

    The objectives of the Lunar Ejecta and Meteorites Experiment (LEAM) were to measure the long-term variations in cosmic dust influx rates and the extent and nature of the lunar ejecta. While analyzing these characteristics in the data, it was discovered that a majority of the events could not be associated with hypervelocity particle impacts of the type usually identified with cosmic dust, but could only be correlated with the lunar surface and local sun angle. The possibility that charged particles could be incident on the sensors led to an analysis of the electronics to determine if such signals could cause the large pulse height analysis (PHA) signals. A qualitative analysis of the PHA circuit showed that an alternative mode of operation existed if the input signal were composed of pulses with pulse durations very long compared to the durations for which it was designed. This alternative mode would give large PHA outputs even though the actual input amplitudes were small. This revelation led to the examination of the sensor and its response to charged particles to determine the type of signals that could be expected.

  4. Factors influencing the airborne capture of respirable charged particles by surfactants in water sprays.

    PubMed

    Tessum, Mei W; Raynor, Peter C; Keating-Klika, Lorraine

    2014-01-01

    This research measured the effects of particle diameter, surfactant-containing spray solution, and particle charge on the capture of respirable particles by surfactant-containing water spray droplets. Polystyrene latex particles with diameters of 0.6, 1.0, or 2.1 μm were generated in a wind tunnel. Particles were given either a neutralized, unneutralized, net positive, or net negative charge, and then were captured as they passed through sprays containing anionic, cationic, or nonionic surfactant. The remaining particles were sampled, charge-separated, and counted with the sprays on and off at varying voltage levels to assess collection efficiency. Overall efficiencies were measured for particles with all charge levels, as well as efficiencies for particles with specific charge levels. The overall collection efficiency significantly increased with increasing particle diameter. Collection efficiencies of 21.5% ± 9.0%, 58.8% ± 12.5%, and 86.6% ± 43.5% (Mean ± SD) were observed for particles 0.6, 1.0, and 2.1 μm in diameter, respectively. The combination of surfactant classification and concentration also significantly affected both overall spray collection efficiency and collection efficiency for particles with specific charge levels. Ionic surfactant-containing sprays had the best performance for charged particles with the opposite sign of charge but the worst performance for charged particles with the same sign of charge, while nonionic surfactant-containing spray efficiently removed particles carrying relatively few charges. Particle charge level impacted the spray collection efficiency. Highly charged particles were removed more efficiently than weakly charged particles.

  5. Factors influencing the airborne capture of respirable charged particles by surfactants in water sprays.

    PubMed

    Tessum, Mei W; Raynor, Peter C; Keating-Klika, Lorraine

    2014-01-01

    This research measured the effects of particle diameter, surfactant-containing spray solution, and particle charge on the capture of respirable particles by surfactant-containing water spray droplets. Polystyrene latex particles with diameters of 0.6, 1.0, or 2.1 μm were generated in a wind tunnel. Particles were given either a neutralized, unneutralized, net positive, or net negative charge, and then were captured as they passed through sprays containing anionic, cationic, or nonionic surfactant. The remaining particles were sampled, charge-separated, and counted with the sprays on and off at varying voltage levels to assess collection efficiency. Overall efficiencies were measured for particles with all charge levels, as well as efficiencies for particles with specific charge levels. The overall collection efficiency significantly increased with increasing particle diameter. Collection efficiencies of 21.5% ± 9.0%, 58.8% ± 12.5%, and 86.6% ± 43.5% (Mean ± SD) were observed for particles 0.6, 1.0, and 2.1 μm in diameter, respectively. The combination of surfactant classification and concentration also significantly affected both overall spray collection efficiency and collection efficiency for particles with specific charge levels. Ionic surfactant-containing sprays had the best performance for charged particles with the opposite sign of charge but the worst performance for charged particles with the same sign of charge, while nonionic surfactant-containing spray efficiently removed particles carrying relatively few charges. Particle charge level impacted the spray collection efficiency. Highly charged particles were removed more efficiently than weakly charged particles. PMID:24479508

  6. Energetic charged particle sources in Saturn's and Jupiter's magnetoshperes

    NASA Astrophysics Data System (ADS)

    Roussos, Elias

    2015-04-01

    In this talk we review observations of high energy particle sources in the jovian and saturnian magnetospheres. We focus on both direct sources (e.g. CRAND, direct CME particle entry) and acceleration mechanisms (e.g. adiabatic heating, centrifugal interchange injections, wave particle interactions, impulsive events/transient radiation belts, reconnection etc.), using data mostly from Cassini, Galileo and Ulysses. We use a comparative approach, theoretical context and references to Earth observations to understand which of the sources and acceleration processes are fundamental for fast-rotating magnetospheres with internal plasma sources and which ones can be attributed to the specifics of each system.

  7. Control Experiment of Positively Charged Fine Particles at the Atmospheric Pressure

    SciTech Connect

    Yokota, Toshiaki; Ando, Ayumi; Sato, Noriyoshi

    2005-10-31

    It is already reported that the negatively charged fine particle flow was controlled by application of external electric field. The control of positively charged fine particles was examined in this experiment.The fine particles are able to take charges in the air under the atmospheric pressure by irradiation of UV light. The control of the positively charged fine particles has been attempted by the external electric field applied the negative potential. The fine particles for experiments are volcanic ashes, nylon 16, glass, and ice. Experiment was performed in the T-shaped glass chamber under the atmospheric pressure. The halogen lamp (500 W) was used to exit the electrons from particles by photo-emission. The ring and disk electrodes to control the positively charged particles were set at the bottom of chamber. The parallel electrodes were set at the middle of chamber and horizontal static electric fields (E = 0 {approx} 210 V/cm) were created in order to estimate the charge of fine particles. The charges of particle were estimated by the deflection of particle trajectory in the static electric fields and particle velocity. The estimated charges were 104e {approx} 5x106e and 103e {approx} 105e for volcanic ashes and nylon 16, respectively. When positively charged particles were introduced into collecting electrodes, the fine particles are collected in the electrodes. The result of control of positively charged fine particles is shown in this conference.

  8. Charged Particle Effects on Solar Sails - An Overview

    NASA Technical Reports Server (NTRS)

    Garrett, Henry B.; Minow, Joseph I.

    2004-01-01

    The NASA In-Space Propulsion Program is currently sponsoring a comprehensive look at the effects of the charged particle environment on the first generation of Solar Sail propulsion systems. As part of this, a joint NASA MSFC/JPL team is investigating the effects of spacecraft charging on the preliminary ISP Solar Sail mission designs. This paper will begin by reviewing the plasma environments being proposed for such missions-these range from the ambient solar wind at approximately 1 AU in the ecliptic plane, approximately 0.5 AU solar-polar orbit, and geosynchronous orbit. Following a discussion of the critical design issues associated with Solar Sails from a charging standpoint, a simple Sail configuration for modeling purposes will be presented. Results for the various environments will be illustrated in terms of the estimated surface potentials for the Solar Sail using the NASCAP-2K charging analysis program. Based on these potentials, representative plasma flow fields and potential contours surrounding the Solar Sail will then be presented. The implications of these results--the surface potentials and plasma flow--will be discussed in the context of their effects on Solar Sail operations and structural configurations.

  9. Correction of the deterministic part of space-charge interaction in momentum microscopy of charged particles.

    PubMed

    Schönhense, G; Medjanik, K; Tusche, C; de Loos, M; van der Geer, B; Scholz, M; Hieke, F; Gerken, N; Kirschner, J; Wurth, W

    2015-12-01

    Ultrahigh spectral brightness femtosecond XUV and X-ray sources like free electron lasers (FEL) and table-top high harmonics sources (HHG) offer fascinating experimental possibilities for analysis of transient states and ultrafast electron dynamics. For electron spectroscopy experiments using illumination from such sources, the ultrashort high-charge electron bunches experience strong space-charge interactions. The Coulomb interactions between emitted electrons results in large energy shifts and severe broadening of photoemission signals. We propose a method for a substantial reduction of the effect by exploiting the deterministic nature of space-charge interaction. The interaction of a given electron with the average charge density of all surrounding electrons leads to a rotation of the electron distribution in 6D phase space. Momentum microscopy gives direct access to the three momentum coordinates, opening a path for a correction of an essential part of space-charge interaction. In a first experiment with a time-of-flight momentum microscope using synchrotron radiation at BESSY, the rotation in phase space became directly visible. In a separate experiment conducted at FLASH (DESY), the energy shift and broadening of the photoemission signals were quantified. Finally, simulations of a realistic photoemission experiment including space-charge interaction reveals that a gain of an order of magnitude in resolution is possible using the correction technique presented here. PMID:26051657

  10. Correction of the deterministic part of space-charge interaction in momentum microscopy of charged particles.

    PubMed

    Schönhense, G; Medjanik, K; Tusche, C; de Loos, M; van der Geer, B; Scholz, M; Hieke, F; Gerken, N; Kirschner, J; Wurth, W

    2015-12-01

    Ultrahigh spectral brightness femtosecond XUV and X-ray sources like free electron lasers (FEL) and table-top high harmonics sources (HHG) offer fascinating experimental possibilities for analysis of transient states and ultrafast electron dynamics. For electron spectroscopy experiments using illumination from such sources, the ultrashort high-charge electron bunches experience strong space-charge interactions. The Coulomb interactions between emitted electrons results in large energy shifts and severe broadening of photoemission signals. We propose a method for a substantial reduction of the effect by exploiting the deterministic nature of space-charge interaction. The interaction of a given electron with the average charge density of all surrounding electrons leads to a rotation of the electron distribution in 6D phase space. Momentum microscopy gives direct access to the three momentum coordinates, opening a path for a correction of an essential part of space-charge interaction. In a first experiment with a time-of-flight momentum microscope using synchrotron radiation at BESSY, the rotation in phase space became directly visible. In a separate experiment conducted at FLASH (DESY), the energy shift and broadening of the photoemission signals were quantified. Finally, simulations of a realistic photoemission experiment including space-charge interaction reveals that a gain of an order of magnitude in resolution is possible using the correction technique presented here.

  11. Theoretical and Computational Investigation of Periodically Focused Intense Charged-Particle Beams

    SciTech Connect

    Chen, Chiping

    2013-06-26

    The purpose of this report is to summarize results of theoretical and computational investigations of periodically focused intense charged-particle beams in parameter regimes relevant to the development of advanced high-brightness, high-power accelerators for high-energy physics research. The breakthroughs and highlights in our research in the period from April 1, 2010 to March 30, 2013 were: a) Theory and simulation of adiabatic thermal Child-Langmuir flow; b) Particle-in-cell simulations of adiabatic thermal beams in periodic solenoidal focusing field; c)Dynamics of charged particles in an adiabatic thermal beam equilibrium in a periodic solenoidal focusing field; d) Training of undergraduate researchers and graduate student in accelerator and beam physics. A brief introduction and summary is presented. Detailed descriptions of research results are provided in an appendix of publications at the end of the report.

  12. Monte Carlo simulation of charged particle impact on the satellites of Jupiter and Saturn

    NASA Technical Reports Server (NTRS)

    Bell, E. V., II; Armstrong, T. P.

    1986-01-01

    Ensemble-averaged lifetimes of Jovian and Saturnian trapped charged particles against loss by impact on natural satellites are presented. Precise values of these loss rates can be obtained from the known geometry of the satellite orbits, magnetic fields, and particle trajectory. These loss rates are needed as an ingredient of transport theory which is usually formulated in terms of the first and second adiabatic invariants and radial distance. The effects of satellite orbital inclination and eccentricity, ion charge to mass ratio and energy, equatorial pitch, and distance from the planet on the particle lifetime are discussed utilizing a tilted, but not offset, dipolar field geometry resulting in lifetime values expressed as functions of the first two adiabatic invariants and the equatorial radial distance from the planet.

  13. Charging and coagulation of radioactive and nonradioactive particles in the atmosphere

    SciTech Connect

    Kim, Yong-ha; Yiacoumi, Sotira; Nenes, Athanasios; Tsouris, Costas

    2016-01-01

    Charging and coagulation influence one another and impact the particle charge and size distributions in the atmosphere. However, few investigations to date have focused on the coagulation kinetics of atmospheric particles accumulating charge. This study presents three approaches to include mutual effects of charging and coagulation on the microphysical evolution of atmospheric particles such as radioactive particles. The first approach employs ion balance, charge balance, and a bivariate population balance model (PBM) to comprehensively calculate both charge accumulation and coagulation rates of particles. The second approach involves a much simpler description of charging, and uses a monovariate PBM and subsequent effects of charge on particle coagulation. The third approach is further simplified assuming that particles instantaneously reach their steady-state charge distributions. It is found that compared to the other two approaches, the first approach can accurately predict time-dependent changes in the size and charge distributions of particles over a wide size range covering from the free molecule to continuum regimes. The other two approaches can reliably predict both charge accumulation and coagulation rates for particles larger than about 0.04 micrometers and atmospherically relevant conditions. These approaches are applied to investigate coagulation kinetics of particles accumulating charge in a radioactive neutralizer, the urban atmosphere, and an atmospheric system containing radioactive particles. Limitations of the approaches are discussed.

  14. Charging and coagulation of radioactive and nonradioactive particles in the atmosphere

    DOE PAGESBeta

    Kim, Yong-ha; Yiacoumi, Sotira; Nenes, Athanasios; Tsouris, Costas

    2016-01-01

    Charging and coagulation influence one another and impact the particle charge and size distributions in the atmosphere. However, few investigations to date have focused on the coagulation kinetics of atmospheric particles accumulating charge. This study presents three approaches to include mutual effects of charging and coagulation on the microphysical evolution of atmospheric particles such as radioactive particles. The first approach employs ion balance, charge balance, and a bivariate population balance model (PBM) to comprehensively calculate both charge accumulation and coagulation rates of particles. The second approach involves a much simpler description of charging, and uses a monovariate PBM and subsequentmore » effects of charge on particle coagulation. The third approach is further simplified assuming that particles instantaneously reach their steady-state charge distributions. It is found that compared to the other two approaches, the first approach can accurately predict time-dependent changes in the size and charge distributions of particles over a wide size range covering from the free molecule to continuum regimes. The other two approaches can reliably predict both charge accumulation and coagulation rates for particles larger than about 0.04 micrometers and atmospherically relevant conditions. These approaches are applied to investigate coagulation kinetics of particles accumulating charge in a radioactive neutralizer, the urban atmosphere, and an atmospheric system containing radioactive particles. Limitations of the approaches are discussed.« less

  15. Improved non-invasive method for aerosol particle charge measurement employing in-line digital holography

    NASA Astrophysics Data System (ADS)

    Tripathi, Anjan Kumar

    Electrically charged particles are found in a wide range of applications ranging from electrostatic powder coating, mineral processing, and powder handling to rain-producing cloud formation in atmospheric turbulent flows. In turbulent flows, particle dynamics is influenced by the electric force due to particle charge generation. Quantifying particle charges in such systems will help in better predicting and controlling particle clustering, relative motion, collision, and growth. However, there is a lack of noninvasive techniques to measure particle charges. Recently, a non-invasive method for particle charge measurement using in-line Digital Holographic Particle Tracking Velocimetry (DHPTV) technique was developed in our lab, where charged particles to be measured were introduced to a uniform electric field, and their movement towards the oppositely charged electrode was deemed proportional to the amount of charge on the particles (Fan Yang, 2014 [1]). However, inherent speckle noise associated with reconstructed images was not adequately removed and therefore particle tracking data was contaminated. Furthermore, particle charge calculation based on particle deflection velocity neglected the particle drag force and rebound effect of the highly charged particles from the electrodes. We improved upon the existing particle charge measurement method by: 1) hologram post processing, 2) taking drag force into account in charge calculation, 3) considering rebound effect. The improved method was first fine-tuned through a calibration experiment. The complete method was then applied to two different experiments, namely conduction charging and enclosed fan-driven turbulence chamber, to measure particle charges. In all three experiments conducted, the particle charge was found to obey non-central t-location scale family of distribution. It was also noted that the charge distribution was insensitive to the change in voltage applied between the electrodes. The range of voltage

  16. Charged-particle energy loss by the excitation of surface magnetoplasmons in a structure with two- and three-dimensional plasmas

    SciTech Connect

    Averkov, Yu. O. Prokopenko, Yu. V.; Yakovenko, V. M.

    2015-10-15

    Electron energy loss by the excitation of surface magnetoplasma oscillations by an electron moving along a static magnetic field in vacuum over a two-dimensional plasma layer on the surface of three-dimensional plasma half-space has been studied theoretically. Electron energy loss by the excitation of surface magnetoplasmons has been calculated in the electrostatic approximation. It has been shown that the type of the dispersion law of electrons in such a plasma (quadratic for a two-dimensional Drude gas or linear for graphene) can be determined from the qualitative character of the dependence of the maximum of the spectral density of this loss on the electron density in the two-dimensional plasma.

  17. Spontaneous alignment in charged-particle systems: Fixed-length vs micellar situations

    NASA Astrophysics Data System (ADS)

    McMullen, William; Gelbart, William M.; Rosenfeld, Yaakov

    1986-07-01

    We use a recently developed version of the soft-mean-spherical approximation (SMSA) to treat spontaneous alignment in suspensions of ionic, rod-like particles. In particular our theory derives from the charge-smearing idea of Onsager in which a lower bound is established for the free energy of the interacting system. First we treat the usual case of fixed-particle lengths and establish the regimes in which the charged lines behave like hard spherocylinders (i.e., the ``smearing'' length plays the role of a hard-core diameter). In general, the nematic phase is superceded by the solid whenever the rod length is too small or too large. Then we consider explicitly the micellar situation in which the particle lengths are determined by the thermodynamics (and vice versa). Here we find the possibility of a reentrant isotropic phase. At low temperatures the nematic becomes unstable because the alignment-induced growth leads to too large a charging (``self'') energy for the micelles. We also predict an ideal solution-like behavior for the growth of micelles in sufficiently concentrated isotropic phases. Finally we comment on the differences between our charge-smearing description of spontaneous alignment in ionic systems and a collective-coordinate approach due to Deutsch and Goldenfeld.

  18. Rayleigh approximation for the scattering of small partially charged sand particles.

    PubMed

    Li, Xingcai; Min, Xing; Liu, Dandan

    2014-07-01

    Based on the Rayleigh approximation, this paper presents the electromagnetic scattering properties of the small partially charged isotropic sphere and those of a similar anisotropic sphere and then discusses the effect of surface charges on particles' optical properties. The numerical simulation results show that the surface charges on a charged particle can enhance the scattering of the incident waves, and the effect on an anisotropic charged sphere is much greater than that on an isotropic charged particle. Therefore it is necessary to consider the medium property (isotropic or anisotropic) and electric effects of dust particles in the remote sensing of sandstorms. PMID:25121437

  19. The theory of charged particle temperatures in the upper atmosphere.

    NASA Technical Reports Server (NTRS)

    Schunk, R. W.; Walker, J. C. G.

    1973-01-01

    The thermal structure of the earth's upper atmosphere is examined in detail, with emphasis on the physical processes that govern the behavior of charged-particle temperatures. The characteristic features of and competition between the heating, cooling, and thermal conduction processes that govern electron and ion temperatures in the mid-latitude and auroral ionospheric regions are theoretically analyzed, and appropriate comparisons are made with experimental data. The proposed elaborate theory is considered qualitatively successful in accounting for the thermal structure of the ionosphere, and points requiring quantitative verification are delineated.

  20. Interaction for solitary waves in coasting charged particle beams

    NASA Astrophysics Data System (ADS)

    Liu, Shi-Wei; Qi, Xin; Han, Jiu-Ning; Hong, Xue-Ren; Shi, Yu-Ren; Duan, Wen-shan; Yang, Lei

    2014-03-01

    By using the extended Poincare-Lighthill-Kuo perturbation method, the collision of solitary waves in a coasting charged particle beams is studied. The results show that the system admits a solution with two solitary waves, which move in opposite directions and can be described by two Korteweg-deVries equation in small-amplitude limit. The collision of two solitary waves is elastic, and after the interaction they preserve their original properties. Then the weak phase shift in traveling direction of collision between two solitary waves is derived explicitly.

  1. Interaction for solitary waves in coasting charged particle beams

    SciTech Connect

    Liu, Shi-Wei; Hong, Xue-Ren; Shi, Yu-Ren; Duan, Wen-shan; Qi, Xin; Yang, Lei; Han, Jiu-Ning

    2014-03-15

    By using the extended Poincare-Lighthill-Kuo perturbation method, the collision of solitary waves in a coasting charged particle beams is studied. The results show that the system admits a solution with two solitary waves, which move in opposite directions and can be described by two Korteweg-deVries equation in small-amplitude limit. The collision of two solitary waves is elastic, and after the interaction they preserve their original properties. Then the weak phase shift in traveling direction of collision between two solitary waves is derived explicitly.

  2. Electromagnetic potential vectors and the Lagrangian of a charged particle

    NASA Technical Reports Server (NTRS)

    Shebalin, John V.

    1992-01-01

    Maxwell's equations can be shown to imply the existence of two independent three-dimensional potential vectors. A comparison between the potential vectors and the electric and magnetic field vectors, using a spatial Fourier transformation, reveals six independent potential components but only four independent electromagnetic field components for each mode. Although the electromagnetic fields determined by Maxwell's equations give a complete description of all possible classical electromagnetic phenomena, potential vectors contains more information and allow for a description of such quantum mechanical phenomena as the Aharonov-Bohm effect. A new result is that a charged particle Lagrangian written in terms of potential vectors automatically contains a 'spontaneous symmetry breaking' potential.

  3. Charged-Particle Calibration Of Spacecraft-Ranging Signals

    NASA Technical Reports Server (NTRS)

    Nguyen, Tien M.

    1992-01-01

    Report discusses determination of effective densities of electrically charged particles along paths of microwave signals transmitted to and from spacecraft and use of those densities to calibrate measured signal-propagation times, used to compute distances between ground stations and spacecraft. Oriented toward selection of method of calibration optimal with respect to three criteria: minimization of range error and of root-mean-square uncertainty in range error; minimization of amount, complexity, and/or cost of equipment; and capability of calibrating changes in group velocities of signals on ranging channel.

  4. Laser-driven deflection arrangements and methods involving charged particle beams

    DOEpatents

    Plettner, Tomas; Byer, Robert L.

    2011-08-09

    Systems, methods, devices and apparatus are implemented for producing controllable charged particle beams. In one implementation, an apparatus provides a deflection force to a charged particle beam. A source produces an electromagnetic wave. A structure, that is substantially transparent to the electromagnetic wave, includes a physical structure having a repeating pattern with a period L and a tilted angle .alpha., relative to a direction of travel of the charged particle beam, the pattern affects the force of the electromagnetic wave upon the charged particle beam. A direction device introduces the electromagnetic wave to the structure to provide a phase-synchronous deflection force to the charged particle beam.

  5. Self-biased silicon detectors with a built-in field for measuring heavy charged particles

    SciTech Connect

    Kim, Y.; Kim, C.; Ohkawa, S.; Husimi, K.; Shiraishi, F.; Osada, S.; Abe, T.; Sakai, T.

    1986-02-01

    Self-biased silicon detectors with a good carrier collection and a high speed response have been produced by using a wafer with high resistive epitaxial layer grown on a low resistive silicon substrate and also a wafer with the graded impurity distribution formed diffusion technique. The build-in field induced by a large difference of impurity concentration is expected to be effective for sweeping away the high density charge plasma to electrodes before recombination. Energy spectra of fission fragments from /sup 252/C/sub F/ are measured by using the detectors. The results show that the detector will be promising for measurement of heavy charged particles.

  6. A New Method to Study Hawking Radiation of Charged Particle from Stationary Axisymmetric Sen Black Hole

    NASA Astrophysics Data System (ADS)

    Yang, Shu-Zheng; Chen, De-You

    2007-01-01

    Taking the self-gravitation interaction and energy conservation, charge conservation and angular momentum conservation into account, we discuss the tunnelling characteristics of the charged particle from Sen black hole by the Hamilton-Jacobi method. The result shows that the tunnelling probability is related to the change of Bekenstein-Hawking entropy, and the actual radiation spectrum deviates from the pure thermal one, which is consistent with the result of Parikh and Wilczek and gives a new method to correct the Hawking pure thermal spectrum of Sen black hole.

  7. Comparisons Between Model Predictions and Spectral Measurements of Charged and Neutral Particles on the Martian Surface

    NASA Technical Reports Server (NTRS)

    Kim, Myung-Hee Y.; Cucinotta, Francis A.; Zeitlin, Cary; Hassler, Donald M.; Ehresmann, Bent; Rafkin, Scot C. R.; Wimmer-Schweingruber, Robert F.; Boettcher, Stephan; Boehm, Eckart; Guo, Jingnan; Koehler, Jan; Martin, Cesar; Reitz, Guenther; Posner, Arik

    2014-01-01

    Detailed measurements of the energetic particle radiation environment on the surface of Mars have been made by the Radiation Assessment Detector (RAD) on the Curiosity rover since August 2012. RAD is a particle detector that measures the energy spectrum of charged particles (10 to approx. 200 MeV/u) and high energy neutrons (approx 8 to 200 MeV). The data obtained on the surface of Mars for 300 sols are compared to the simulation results using the Badhwar-O'Neill galactic cosmic ray (GCR) environment model and the high-charge and energy transport (HZETRN) code. For the nuclear interactions of primary GCR through Mars atmosphere and Curiosity rover, the quantum multiple scattering theory of nuclear fragmentation (QMSFRG) is used. For describing the daily column depth of atmosphere, daily atmospheric pressure measurements at Gale Crater by the MSL Rover Environmental Monitoring Station (REMS) are implemented into transport calculations. Particle flux at RAD after traversing varying depths of atmosphere depends on the slant angles, and the model accounts for shielding of the RAD "E" dosimetry detector by the rest of the instrument. Detailed comparisons between model predictions and spectral data of various particle types provide the validation of radiation transport models, and suggest that future radiation environments on Mars can be predicted accurately. These contributions lend support to the understanding of radiation health risks to astronauts for the planning of various mission scenarios

  8. Physical sputtering of metallic systems by charged-particle impact

    SciTech Connect

    Lam, N.Q.

    1989-12-01

    The present paper provides a brief overview of our current understanding of physical sputtering by charged-particle impact, with the emphasis on sputtering of metals and alloys under bombardment with particles that produce knock-on collisions. Fundamental aspects of ion-solid interactions, and recent developments in the study of sputtering of elemental targets and preferential sputtering in multicomponent materials are reviewed. We concentrate only on a few specific topics of sputter emission, including the various properties of the sputtered flux and depth of origin, and on connections between sputtering and other radiation-induced and -enhanced phenomena that modify the near-surface composition of the target. The synergistic effects of these diverse processes in changing the composition of the integrated sputtered-atom flux is described in simple physical terms, using selected examples of recent important progress. 325 refs., 27 figs.

  9. Mars Dust: Characterization of Particle Size and Electrostatic Charge Distribution

    NASA Technical Reports Server (NTRS)

    Mazumder, M. K.; Saini, D.; Biris, A. S.; Sriama, P. K.; Calle, C.; Buhler, C.

    2004-01-01

    Some of the latest pictures of Mars surface sent by NASA's Spirit rover in early January, 2004, show very cohesive, "mud-like" dust layers. Significant amounts of dust clouds are present in the atmosphere of Mars [1-4]. NASA spacecraft missions to Mars confirmed hypotheses from telescopic work that changes observed in the planet's surface markings are caused by wind-driven redistribution of dust. In these dust storms, particles with a wide range of diameters (less than 1 micrometer to 50 micrometers) are a serious problem to solar cells, spacecraft, and spacesuits. Dust storms may cover the entire planet for an extended period of time [5]. It is highly probable that the particles are charged electrostatically by triboelectrification and by UV irradiation.

  10. Thermodynamic Bounds on Nonlinear Electrostatic Perturbations in Intense Charged Particle Beams

    SciTech Connect

    Nikolas C. Logan and Ronald C. Davidson

    2012-07-18

    This paper places a lowest upper bound on the field energy in electrostatic perturbations in single-species charged particle beams with initial temperature anisotropy (TllT⊥ < 1). The result applies to all electrostatic perturbations driven by the natural anisotropies that develop in accelerated particle beams, including Harris-type electrostatic instabilities, known to limit the luminosity and minimum spot size attainable in experiments. The thermodynamic bound on the field perturbation energy of the instabilities is obtained from the nonlinear Vlasov-Poisson equations for an arbitrary initial distribution function, including the effects of intense self-fields, finite geometry and nonlinear processes. This paper also includes analytical estimates of the nonlinear bounds for space-charge-dominated and emittance-dominated anisotropic bi-Maxwellian distributions.

  11. Thermodynamic bounds on nonlinear electrostatic perturbations in intense charged particle beams

    SciTech Connect

    Logan, Nikolas C.; Davidson, Ronald C.

    2012-07-15

    This paper places a lowest upper bound on the field energy in electrostatic perturbations in single-species charged particle beams with initial temperature anisotropy (T{sub Parallel-To }/T{sub Up-Tack }<1). The result applies to all electrostatic perturbations driven by the natural anisotropies that develop in accelerated particle beams, including Harris-type electrostatic instabilities, known to limit the luminosity and minimum spot size attainable in experiments. The thermodynamic bound on the field perturbation energy of the instabilities is obtained from the nonlinear Vlasov-Poisson equations for an arbitrary initial distribution function, including the effects of intense self-fields, finite geometry, and nonlinear processes. This paper also includes analytical estimates of the nonlinear bounds for space-charge-dominated and emittance-dominated anisotropic bi-Maxwellian distributions.

  12. Survival of Deinococcus radiodurans against laboratory-simulated solar wind charged particles.

    PubMed

    Paulino-Lima, Ivan Gláucio; Janot-Pacheco, Eduardo; Galante, Douglas; Cockell, Charles; Olsson-Francis, Karen; Brucato, John Robert; Baratta, Giuseppe Antonio; Strazzulla, Giovanni; Merrigan, Tony; McCullough, Robert; Mason, Nigel; Lage, Claudia

    2011-11-01

    In this experimental study, cells of the radiation-resistant bacterium Deinococcus radiodurans were exposed to several different sources of radiation chosen to replicate the charged particles found in the solar wind. Naked cells or cells mixed with dust grains (basalt or sandstone) differing in elemental composition were exposed to electrons, protons, and ions to determine the probability of cell survival after irradiation. Doses necessary to reduce the viability of cell population to 10% (LD(10)) were determined under different experimental conditions. The results of this study indicate that low-energy particle radiation (2-4 keV), typically present in the slow component of the solar wind, had no effect on dehydrated cells, even if exposed at fluences only reached in more than 1000 years at Sun-Earth distance (1 AU). Higher-energy ions (200 keV) found in solar flares would inactivate 90% of exposed cells after several events in less than 1 year at 1 AU. When mixed with dust grains, LD(10) increases about 10-fold. These results show that, compared to the highly deleterious effects of UV radiation, solar wind charged particles are relatively benign, and organisms protected under grains from UV radiation would also be protected from the charged particles considered in this study.

  13. On the acceleration of charged particles at relativistic shock fronts

    NASA Technical Reports Server (NTRS)

    Kirk, J. G.; Schneider, P.

    1987-01-01

    The diffusive acceleration of highly relativistic particles at a shock is reconsidered. Using the same physical assumptions as Blandford and Ostriker (1978), but dropping the restriction to nonrelativistic shock velocities, the authors find approximate solutions of the particle kinetic equation by generalizing the diffusion approximation to higher order terms in the anisotropy of the particle distribution. The general solution of the transport equation on either side of the shock is constructed, which involves the solution of an eigenvalue problem. By matching the two solutions at the shock, the spectral index of the resulting power law is found by taking into account a sufficiently large number of eigenfunctions. Low-order truncation corresponds to the standard diffusion approximation and to a somewhat more general method described by Peacock (1981). In addition to the energy spectrum, the method yields the angular distribution of the particles and its spatial dependence.

  14. Modeling of mesoscopic electrokinetic phenomena using charged dissipative particle dynamics

    NASA Astrophysics Data System (ADS)

    Deng, Mingge; Li, Zhen; Karniadakis, George

    2015-11-01

    In this work, we propose a charged dissipative particle dynamics (cDPD) model for investigation of mesoscopic electrokinetic phenomena. In particular, this particle-based method was designed to simulate micro- or nano- flows which governing by Poisson-Nernst-Planck (PNP) equation coupled with Navier-Stokes (NS) equation. For cDPD simulations of wall-bounded fluid systems, a methodology for imposing correct Dirichlet and Neumann boundary conditions for both PNP and NS equations is developed. To validate the present cDPD model and the corresponding boundary method, we perform cDPD simulations of electrostatic double layer (EDL) in the vicinity of a charged wall, and the results show good agreement with the mean-field theoretical solutions. The capacity density of a parallel plate capacitor in salt solution is also investigated with different salt concentration. Moreover, we utilize the proposed methodology to study the electroosmotic and electroosmotic/pressure-driven flow in a micro-channel. In the last, we simulate the dilute polyelectrolyte solution both in bulk and micro-channel, which show the flexibility and capability of this method in studying complex fluids. This work was sponsored by the Collaboratory on Mathematics for Mesoscopic Modeling of Materials (CM4) supported by DOE.

  15. Diagnostic resonant cavity for a charged particle accelerator

    DOEpatents

    Barov, Nikolai

    2007-10-02

    Disclosed is a diagnostic resonant cavity for determining characteristics of a charged particle beam, such as an electron beam, produced in a charged particle accelerator. The cavity is based on resonant quadrupole-mode and higher order cavities. Enhanced shunt impedance in such cavities is obtained by the incorporation of a set of four or more electrically conductive rods extending inwardly from either one or both of the end walls of the cavity, so as to form capacitive gaps near the outer radius of the beam tube. For typical diagnostic cavity applications, a five-fold increase in shunt impedance can be obtained. In alternative embodiments the cavity may include either four or more opposing pairs of rods which extend coaxially toward one another from the opposite end walls of the cavity and are spaced from one another to form capacitative gaps; or the cavity may include a single set of individual rods that extend from one end wall to a point adjacent the opposing end wall.

  16. Boron concentration measurement in biological tissues by charged particle spectrometry.

    PubMed

    Bortolussi, S; Altieri, S

    2013-11-01

    Measurement of boron concentration in biological tissues is a fundamental aspect of boron neutron capture therapy, because the outcome of the therapy depends on the distribution of boron at a cellular level, besides on its overall concentration. This work describes a measurement technique based on the spectroscopy of the charged particles emitted in the reaction (10)B(n,α)(7)Li induced by thermal neutrons, allowing for a quantitative determination of the boron concentration in the different components that may be simultaneously present in a tissue sample, such as healthy cells, tumor cells and necrotic cells. Thin sections of tissue containing (10)B are cut at low temperatures and irradiated under vacuum in a thermal neutron field. The charged particles arising from the sample during the irradiation are collected by a thin silicon detector, and their spectrum is used to determine boron concentration through relatively easy calculations. The advantages and disadvantages of this technique are here described, and validation of the method using tissue standards with known boron concentrations is presented.

  17. A study of CR-39 plastic charged-particle detector replacement by consumer imaging sensors

    NASA Astrophysics Data System (ADS)

    Plaud-Ramos, K. O.; Freeman, M. S.; Wei, W.; Guardincerri, E.; Bacon, J. D.; Cowan, J.; Durham, J. M.; Huang, D.; Gao, J.; Hoffbauer, M. A.; Morley, D. J.; Morris, C. L.; Poulson, D. C.; Wang, Zhehui

    2016-11-01

    Consumer imaging sensors (CIS) are examined for real-time charged-particle detection and CR-39 plastic detector replacement. Removing cover glass from CIS is hard if not impossible, in particular for the latest inexpensive webcam models. We show that 10-class CIS are sensitive to MeV and higher energy protons and α-particles by using a 90Sr β-source with its cover glass in place. Indirect, real-time, high-resolution detection is also feasible when combining CIS with a ZnS:Ag phosphor screen and optics. Noise reduction in CIS is nevertheless important for the indirect approach.

  18. The application of thick hydrogenated amorphous silicon layers to charged particle and x-ray detection

    SciTech Connect

    Perez-Mendez, V.; Cho, G.; Fujieda, I.; Kaplan, S.N.; Qureshi, S.; Street, R.A.

    1989-04-01

    We outline the characteristics of thick hydrogenated amorphous silicon layers which are optimized for the detection of charged particles, x-rays and ..gamma..-rays. Signal amplitude as a function of the linear energy transfer of various particles are given. Noise sources generated by the detector material and by the thin film electronics - a-Si:H or polysilicon proposed for pixel position sensitive detectors readout are described, and their relative amplitudes are calculated. Temperature and neutron radiation effects on leakage currents and the corresponding noise changes are presented. 17 refs., 12 figs., 2 tabs.

  19. A study of CR-39 track response to charged particles from NOVA implosions

    NASA Astrophysics Data System (ADS)

    Phillips, T. W.; Cable, M. D.; Hicks, D. G.; Li, C. K.; Petrasso, R. D.; Seguin, F. H.

    1997-01-01

    We have exposed CR-39 track recording material to a number of NOVA implosions. Radiation from the implosion passed through an array of ranging filters, which aided identification of the incident particles and their energies. The etching procedure was calibrated by including a piece of track exposed to DD protons from a small accelerator. For the same shots, we quantitatively compare the DD neutron yield with the DD proton yield determined from the track. In DT implosions, tracks produced by neutron interactions prevent observation of charged-particle tracks that are produced by the processes of knock on, secondary, or tertiary fusion.

  20. Stopping power and scattering angle calculations of charged particle beams through thin foils

    SciTech Connect

    Nassiri, A.

    1991-03-01

    It is important to understand the effects of introducing foils into the path of charged particle beams. In the APS linac system, the intention is to insert thin foils before and after the positron generating target to protect the accelerating structures immediately before and after the target. Electron beams that pass through a dense material lose energy in collisions with the atomic electrons. The scattering path of electrons is much less straight than that of heavier particles (mu, pi meson, K meson, proton, etc.). After a short distance electrons tend to diffuse into the material, rather than proceeding in a rectilinear path.

  1. Suprathermal Charged Particle Acceleration by Small-scale Flux Ropes.

    NASA Astrophysics Data System (ADS)

    Zank, G. P.; le Roux, J. A.; Webb, G. M.

    2015-12-01

    We consider different limits of our recently developed kinetic transport theory to investigate the potential of super-Alvenic solar wind regions containing several small-scale flux ropes to explain the acceleration of suprathermal ions to power-law spectra as observations show. Particle acceleration is modeled in response to flux-rope activity involving contraction, merging (reconnection), and collisions in the limit where the particle gyoradius is smaller than the characteristic flux-rope scale length. The emphasis is mainly on the statistical variance in the electric fields induced by flux-rope dynamics rather than on the mean electric field induced by multiple flux ropes whose acceleration effects are discussed elsewhere. Our steady-state analytical solutions suggest that particle drift acceleration by flux ropes, irrespective of whether displaying incompressible or compressible behavior, can yield power laws asymptotically at higher energies whereas an exponential spectral rollover results asymptotically when field-aligned guiding center motion acceleration occur by reconnection electric fields from merging flux ropes. This implies that at sufficiently high particle energies, drift acceleration might dominate. We also expect compressive flux ropes to yield harder power-law spectra than incompressible flux ropes. Preliminary results will be discussed to illustrate how particle acceleration might be affected when both diffusive shock and small-scale flux acceleration occur simultaneously at interplanetary shocks.

  2. Second-order, exact charge conservation for electromagnetic particle-in-cell simulation in complex geometry

    NASA Astrophysics Data System (ADS)

    Pointon, T. D.

    2008-10-01

    A second-order, exact charge-conserving algorithm for accumulating charge and current on the spatial grid for electromagnetic particle-in-cell (EM-PIC) simulation in bounded geometry is presented. The algorithm supports standard EM-PIC exterior boundary conditions and complex internal conductors on non-uniform grids. Boundary surfaces are handled by smoothly transitioning from second to first-order weighting within half a cell of the boundary. When a particle is exactly on the boundary surface (either about to be killed, or just created), the weighting is fully first-order. This means that particle creation and particle/surface interaction models developed for first-order weighting do not need to be modified. An additional feature is the use of an energy-conserving interpolation scheme from the electric field on the grid to the particles. Results show that high-density, cold plasmas with ωΔt˜1, and Δx/λ≫1, can be modeled with reasonable accuracy and good energy conservation. This opens up a significant new capability for explicit simulation of high-density plasmas in high-power devices.

  3. Charged hadron production in the upsilon energy region

    SciTech Connect

    Morrow, F.H.

    1985-01-01

    The author has examined the production of charged hadrons in e/sup +/e/sup -/ annihilation in the upsilon energy region and has attempted to use this information to study the similarities and differences in the fragementation of quark and gluon jets. Major differences in charged hadron production for continuum (q anti-q) and upsilon(1S) (ggg) events include charged particle multiplicities (higher for upsilon data) and greatly enhanced production of baryons on the resonance. Global event characteristics (e.g., event shape) have been studied in hopes of providing some insight as to the basis for these differences. Comparisons have been made between the data and Monte Carlo simulations of q anti-q and ggg events using the LUND model and the Field phase space parton model. Agreements and disagreements between the data and the model are discussed.

  4. Search for Free Fractional Electric Charge Elementary Particles Using an Automated Millikan Oil Drop Technique

    SciTech Connect

    Halyo, V.; Kim, P.; Lee, E. R.; Lee, I. T.; Loomba, D.; Perl, M. L.

    2000-03-20

    We have carried out a direct search in bulk matter for free fractional electric charge elementary particles using the largest mass single sample ever studied--about 17.4 mg of silicone oil. The search used an improved and highly automated Millikan oil drop technique. No evidence for fractional charge particles was found. The concentration of particles with fractional charge more than 0.16e (e being the magnitude of the electron charge) from the nearest integer charge is less than 4.71x10{sup -22} particles per nucleon with 95% confidence. (c) 2000 The American Physical Society.

  5. Electromagnetic fields and potentials generated by massless charged particles

    NASA Astrophysics Data System (ADS)

    Azzurli, Francesco; Lechner, Kurt

    2014-10-01

    We provide for the first time the exact solution of Maxwell’s equations for a massless charged particle moving on a generic trajectory at the speed of light. In particular we furnish explicit expressions for the vector potential and the electromagnetic field, which were both previously unknown, finding that they entail different physical features for bounded and unbounded trajectories. With respect to the standard Liénard-Wiechert field the electromagnetic field acquires singular δ-like contributions whose support and dimensionality depend crucially on whether the motion is (a) linear, (b) accelerated unbounded, (c) accelerated bounded. In the first two cases the particle generates a planar shock-wave-like electromagnetic field traveling along a straight line. In the second and third cases the field acquires, in addition, a δ-like contribution supported on a physical singularity-string attached to the particle. For generic accelerated motions a genuine radiation field is also present, represented by a regular principal-part type distribution diverging on the same singularity-string.

  6. The search for fractional charge elemental particles and very massive particles in bulk matter

    SciTech Connect

    Perl, M.

    2000-01-12

    The authors describe their ongoing work on, and future plans for, searches in bulk matter for fractional charge elementary particles and very massive elementary particles. Their primary interest is in searching for such particles that may have been produced in the early universe and may be found in the more primeval matter available in the solar system: meteorites, material from the moon's surface, and certain types of ancient terrestrial rocks. In the future the authors are interested in examining material brought back by sample return probes from asteroids. The authors will describe their experimental methods that are based on new modifications of the Millikan liquid drop technique and modern technology: micromachining, CCD cameras, and desktop computers. Extensions of the experimental methods and technology allow searches for very massive charged particles in primeval matter; particles with masses greater than 1,013 GeV. In the first such searches carried out on earth there will be uncertainties in the mass search range. Therefore the authors will also discuss the advantages of eventually carrying out such searches directly on an asteroid.

  7. Particle Segregation at Contact Lines of Evaporating Colloidal Drops: Influence of the Substrate Wettability and Particle Charge-Mass Ratio.

    PubMed

    Noguera-Marín, Diego; Moraila-Martínez, Carmen L; Cabrerizo-Vílchez, Miguel A; Rodríguez-Valverde, Miguel A

    2015-06-23

    Segregation of particles during capillary/convective self-assembly is interesting for self-stratification in colloidal deposits. In evaporating drops containing colloidal particles, the wettability properties of substrate and the sedimentation of particles can affect their accumulation at contact lines. In this work we studied the size segregation and discrimination of charged particles with different densities. We performed in-plane particle counting at evaporating triple lines by using fluorescence confocal microscopy. We studied separately substrates with very different wettability properties and particles with different charge-mass ratios at low ionic strength. We used binary colloidal suspensions to compare simultaneously the deposition of two different particles. The particle deposition rate strongly depends on the receding contact angle of the substrate. We further observed a singular behavior of charged polystyrene particles in binary mixtures under "salt-free" conditions explained by the "colloidal Brazil nut" effect.

  8. Particle Segregation at Contact Lines of Evaporating Colloidal Drops: Influence of the Substrate Wettability and Particle Charge-Mass Ratio.

    PubMed

    Noguera-Marín, Diego; Moraila-Martínez, Carmen L; Cabrerizo-Vílchez, Miguel A; Rodríguez-Valverde, Miguel A

    2015-06-23

    Segregation of particles during capillary/convective self-assembly is interesting for self-stratification in colloidal deposits. In evaporating drops containing colloidal particles, the wettability properties of substrate and the sedimentation of particles can affect their accumulation at contact lines. In this work we studied the size segregation and discrimination of charged particles with different densities. We performed in-plane particle counting at evaporating triple lines by using fluorescence confocal microscopy. We studied separately substrates with very different wettability properties and particles with different charge-mass ratios at low ionic strength. We used binary colloidal suspensions to compare simultaneously the deposition of two different particles. The particle deposition rate strongly depends on the receding contact angle of the substrate. We further observed a singular behavior of charged polystyrene particles in binary mixtures under "salt-free" conditions explained by the "colloidal Brazil nut" effect. PMID:26000909

  9. Stabilization of Pickering Emulsions with Oppositely Charged Latex Particles: Influence of Various Parameters and Particle Arrangement around Droplets.

    PubMed

    Nallamilli, Trivikram; Binks, Bernard P; Mani, Ethayaraja; Basavaraj, Madivala G

    2015-10-20

    In this study we explore the fundamental aspects of Pickering emulsions stabilized by oppositely charged particles. Using oppositely charged latex particles as a model system, Pickering emulsions with good long-term stability can be obtained without the need for any electrolyte. The effects of parameters like oil to water ratio, mixed particle composition, and pH on emulsion type and stability are explored and linked to the behavior of the aqueous particle dispersion prior to emulsification. The particle composition is found to affect the formation of emulsions, viz., stable emulsions were obtained close to a particle number ratio of 1:1, and no emulsion was formed with either positively or negatively charged particles alone. The emulsions in particle mixtures exhibited phase inversion from oil-in-water to water-in-oil beyond an oil volume fraction of 0.8. Morphological features of emulsion droplets in terms of particle arrangement on the droplets are discussed.

  10. Measurement and accumulation of electric charge on a single dielectric particle trapped in air

    NASA Astrophysics Data System (ADS)

    Park, Haesung; LeBrun, Thomas W.

    2016-03-01

    Normally occurring charges on small particles provide a means to control the motion of the particles. Using a piezoelectric transducer to launch microparticles into a trap, we can vary particle-surface interactions to transfer charge to the particle via contact electrification. This allows more detailed studies of contact electrification itself as well generation of higher charge states for precision measurements of force or nonlinear dynamics using electric field modulation. In practice, particles may be repeatedly landed on the substrate and relaunched during loading. This leads to charge transfer so that the net charge on the polystyrene (PS) particle becomes sufficient to allow electrostatic forcing to drive ballistic motion over a range of displacement two orders of magnitude greater than thermal fluctuations. An increase in charge from 1000 to 3000 electrons is demonstrated and the induced motion of the trapped particle is accurately described using simple classical mechanics in phase space.

  11. Charged particle production in Pb-Pb collisions at the LHC with the ALICE detector

    NASA Astrophysics Data System (ADS)

    Floris, M.

    2013-08-01

    The ALICE collaboration measured charged particle production in √{sNN} = 2.76 TeV Pb-Pb collisions at the LHC. We report on results on charged particle multiplicity and transverse momentum spectra. All the results are presented as a function of the centrality of the collision, estimated with a Glauber Monte Carlo fit to multiplicity distributions reconstructed in various detectors. The applicability of the Glauber model at LHC energies, the precision of the centrality determination and the related systematic uncertainties are discussed in detail. Particles are tracked in the pseudorapidity window | η | ≲ 0.9 with the silicon Inner Tracking System (ITS) and the Time Projection Chamber (TPC), over the range 0.15 charged particle multiplicity is measured in | η | < 0.5 to be dNch /d η = 1601 ± 60 in 5% most central Pb-Pb collisions, indicating an energy density a factor ∼ 3 higher than at RHIC. Its evolution with centrality shows a pattern strikingly similar to the one measured at RHIC. Intermediate (5 ≲pT ≲ 15 GeV / c) transverse momentum particles are found to be most strongly suppressed with respect to pp collisions, consistent with a large energy loss of hardscattered partons in the hot and dense medium. The results are presented in terms of the nuclear modification factor RAA and compared to theoretical expectations.

  12. In-plane particle counting at contact lines of evaporating colloidal drops: effect of the particle electric charge.

    PubMed

    Noguera-Marín, Diego; Moraila-Martínez, Carmen L; Cabrerizo-Vílchez, Miguel A; Rodríguez-Valverde, Miguel A

    2015-02-01

    Complete understanding of colloidal assembly is still a goal to be reached. In convective assembly deposition, the concentration gradients developed in evaporating drops or reservoirs are usually significant. However, collective diffusion of charge-stabilized particles has been barely explored. The balance between convective and diffusive flows may dictate the particle dynamics inside evaporating colloidal drops. In this work we performed in situ counting of fluorescent particles in the vicinity of the triple line of evaporating sessile drops by using confocal laser scanning microscopy. We used particles of different sizes, with different charge response over the pH scale and we focused on charged and nearly uncharged particles. Two substrates with different receding contact angles were used. Binary colloidal mixtures were used to illustrate simultaneously the accumulation of particles with two different charge states at the triple line. The deposition rate close to the triple line was different depending on the electric state of the particle, regardless of the substrate used.

  13. High energy charged particle optics computer programs

    SciTech Connect

    Carey, D.C.

    1980-09-01

    The computer programs TRANSPORT and TURTLE are described, with special emphasis on recent developments. TRANSPORT is a general matrix evaluation and fitting program. First and second-order transfer matrix elements, including those contributing to time-of-flight differences can be evaluated. Matrix elements of both orders can be fit, separately or simultaneously. Floor coordinates of the beam line may be calculated and included in any fits. Tables of results of misalignments, including effects of bilinear terms can be produced. Fringe fields and pole face rotation angles of bending magnets may be included and also adjusted automatically during the fitting process to produce rectangular magnets. A great variety of output options are available. TURTLE is a Monte Carlo program used to simulate beam line performance. It includes second-order terms and aperture constraints. Replacable subroutines allow an unliminated variety of input beam distributions, scattering algorithms, variables which can be histogrammed, and aperture shapes. Histograms of beam loss can also be produced. Rectangular zero-gradient bending magnets with proper circular trajectories, sagitta offsets, pole face rotation angles, and aperture constraints can be included. The effect of multiple components of quadrupoles up to 40 poles can be evaluated.

  14. Multiplicity of charged particles in 800 GeV p-p interactions

    NASA Astrophysics Data System (ADS)

    Ammar, R.; Aziz, T.; Banerjee, S.; Baland, J. F.; Ball, S.; Ball, R. C.; Bromberg, C.; Brun, R.; Canough, G. E.; Coffin, T.; Commichau, V.; Davis, R.; Dershem, T. O.; Dixon, R. L.; Fenker, H. C.; Ganguli, S. N.; Gensch, U.; Giokaris, N.; Girtler, P.; Goshaw, A. T.; Gress, J.; Gurtu, A.; Henri, V. P.; Hernandez, J. J.; Hrubec, J.; Iori, M.; Jones, L. W.; Knauss, D.; Kuhn, D.; Kwak, N.; Leedom, I. D.; Legros, P.; Lemonne, J.; Leutz, H.; Liu, X.; Malhotra, P. K.; Marraffino, J. M.; Mendez, G. E.; Mikocki, S.; Miller, R.; Naumann, T.; Neuhofer, G.; Nguyen, A.; Nikolic, M.; Nowak, H.; Pilette, P.; Poppleton, A.; Poirier, J.; Raghavan, R.; Rasner, K.; Reucroft, S.; Robertson, W. J.; Roe, B. P.; Roos, C. E.; Roth, A.; Senko, M.; Struczinski, W.; Subramanian, A.; Touboul, M. C.; Vonck, B.; Voyvodic, L.; Walker, W. D.; Waters, J. W.; Weber, M. F.; Webster, M. S.; Wickens, J.; Wild, C. F.

    1986-09-01

    Results are reported concerning the charged-particle multiplicity distribution obtained in an exposure of the high-resolution hydrogen bubble chamber LEBC to a beam of 800 GeV protons at the Fermilab MPS. This is the first time that such data have been available at this energy. The distribution of the number nch of charged particles produced in inelastic interactions obeys KNO-scaling. The average multiplicity is = 10.26+/-0.15. For nch>=8 the data can be well fitted to a negative binomial. The difference between the overall experimental multiplicity distribution and that resulting from the latter fit is in agreement with the contribution expected from diffractive processes.

  15. Status of the L2 and Lunar Charged Particle Environment Models

    NASA Technical Reports Server (NTRS)

    Minow, Joseph I.; Diekmann, Anne M.; Blackwell, William C., Jr.

    2007-01-01

    The L2 Charged Particle Environment (L2-CPE) model is an engineering tool which provides free field charged particle environments for distant magnetotail, magnetosheath, and solar wind environments. L2-CPE is intended for use in assessing contributions from low energy radiation environments (4.1 keV to few MeV) to radiation dose in thin materials used in construction of spacecraft to be placed in orbit about the Sun-Earth L2 point. This paper describes the status of the current version of the L2-CPE model including structure of the model used to organize plasma environments into solar wind, magnetosheath, and magnetotail environments, the algorithms used to estimate radiation fluence in sparsely sampled environments, the updated graphical user interface, and output options for flux and fluence environments. In addition, we describe the status and plans for updating the model to include environments relevant to lunar programs.

  16. Direct measurement of the 3-dimensional DNA lesion distribution induced by energetic charged particles in a mouse model tissue

    PubMed Central

    Mirsch, Johanna; Tommasino, Francesco; Frohns, Antonia; Conrad, Sandro; Durante, Marco; Scholz, Michael; Friedrich, Thomas; Löbrich, Markus

    2015-01-01

    Charged particles are increasingly used in cancer radiotherapy and contribute significantly to the natural radiation risk. The difference in the biological effects of high-energy charged particles compared with X-rays or γ-rays is determined largely by the spatial distribution of their energy deposition events. Part of the energy is deposited in a densely ionizing manner in the inner part of the track, with the remainder spread out more sparsely over the outer track region. Our knowledge about the dose distribution is derived solely from modeling approaches and physical measurements in inorganic material. Here we exploited the exceptional sensitivity of γH2AX foci technology and quantified the spatial distribution of DNA lesions induced by charged particles in a mouse model tissue. We observed that charged particles damage tissue nonhomogenously, with single cells receiving high doses and many other cells exposed to isolated damage resulting from high-energy secondary electrons. Using calibration experiments, we transformed the 3D lesion distribution into a dose distribution and compared it with predictions from modeling approaches. We obtained a radial dose distribution with sub-micrometer resolution that decreased with increasing distance to the particle path following a 1/r2 dependency. The analysis further revealed the existence of a background dose at larger distances from the particle path arising from overlapping dose deposition events from independent particles. Our study provides, to our knowledge, the first quantification of the spatial dose distribution of charged particles in biologically relevant material, and will serve as a benchmark for biophysical models that predict the biological effects of these particles. PMID:26392532

  17. Direct measurement of the 3-dimensional DNA lesion distribution induced by energetic charged particles in a mouse model tissue.

    PubMed

    Mirsch, Johanna; Tommasino, Francesco; Frohns, Antonia; Conrad, Sandro; Durante, Marco; Scholz, Michael; Friedrich, Thomas; Löbrich, Markus

    2015-10-01

    Charged particles are increasingly used in cancer radiotherapy and contribute significantly to the natural radiation risk. The difference in the biological effects of high-energy charged particles compared with X-rays or γ-rays is determined largely by the spatial distribution of their energy deposition events. Part of the energy is deposited in a densely ionizing manner in the inner part of the track, with the remainder spread out more sparsely over the outer track region. Our knowledge about the dose distribution is derived solely from modeling approaches and physical measurements in inorganic material. Here we exploited the exceptional sensitivity of γH2AX foci technology and quantified the spatial distribution of DNA lesions induced by charged particles in a mouse model tissue. We observed that charged particles damage tissue nonhomogenously, with single cells receiving high doses and many other cells exposed to isolated damage resulting from high-energy secondary electrons. Using calibration experiments, we transformed the 3D lesion distribution into a dose distribution and compared it with predictions from modeling approaches. We obtained a radial dose distribution with sub-micrometer resolution that decreased with increasing distance to the particle path following a 1/r2 dependency. The analysis further revealed the existence of a background dose at larger distances from the particle path arising from overlapping dose deposition events from independent particles. Our study provides, to our knowledge, the first quantification of the spatial dose distribution of charged particles in biologically relevant material, and will serve as a benchmark for biophysical models that predict the biological effects of these particles. PMID:26392532

  18. Weakly nonlinear electrophoresis of a highly charged colloidal particle

    NASA Astrophysics Data System (ADS)

    Schnitzer, Ory; Zeyde, Roman; Yavneh, Irad; Yariv, Ehud

    2013-05-01

    At large zeta potentials, surface conduction becomes appreciable in thin-double-layer electrokinetic transport. In the linear weak-field regime, where this effect is quantified by the Dukhin number, it is manifested in non-Smoluchowski electrophoretic mobilities. In this paper we go beyond linear response, employing the recently derived macroscale model of Schnitzer and Yariv ["Macroscale description of electrokinetic flows at large zeta potentials: Nonlinear surface conduction," Phys. Rev. E 86, 021503 (2012), 10.1103/PhysRevE.86.021503] as the infrastructure for a weakly nonlinear analysis of spherical-particle electrophoresis. A straightforward perturbation in the field strength is frustrated by the failure to satisfy the far-field conditions, representing a non-uniformity of the weak-field approximation at large distances away from the particle, where salt advection becomes comparable to diffusion. This is remedied using inner-outer asymptotic expansions in the spirit of Acrivos and Taylor ["Heat and mass transfer from single spheres in Stokes flow," Phys. Fluids 5, 387 (1962), 10.1063/1.1706630], with the inner region representing the particle neighborhood and the outer region corresponding to distances scaling inversely with the field magnitude. This singular scheme furnishes an asymptotic correction to the electrophoretic velocity, proportional to the applied field cubed, which embodies a host of nonlinear mechanisms unfamiliar from linear electrokinetic theories. These include the effect of induced zeta-potential inhomogeneity, animated by concentration polarization, on electro-osmosis and diffuso-osmosis; bulk advection of salt; nonuniform bulk conductivity; Coulomb body forces acting on bulk volumetric charge; and the nonzero electrostatic force exerted upon the otherwise screened particle-layer system. A numerical solution of the macroscale model validates our weakly nonlinear analysis.

  19. Charged Particle Energization and Transport in Reservoirs throughout the Heliosphere: 1. Solar Energetic Particles

    NASA Astrophysics Data System (ADS)

    Roelof, E. C.

    2015-09-01

    “Reservoirs” of energetic charged particles are regions where the particle population is quasi-trapped in large-scale (relative to the gyroradii) magnetic field structures. Reservoirs are found throughout the heliosphere: the huge heliosheath (90charged particles within these reservoirs is produced by the interaction when the particle magnetic drifts have a component along the large-scale electric fields produced by plasma convection. The appropriate description of this transport is “weak scattering”, in which the particle's first adiabatic invariant (magnetic moment) is approximately conserved while the particle itself moves rather freely along magnetic field lines. Considerable insight into the observed properties of energization processes can be gained from a remarkably simple equation that describes the particle's fractional time-rate-of-change of momentum (dlnp/dt) which depends only upon its pitch angle, the divergence of the plasma velocity (V⊥) transverse to the magnetic field), and the inner product of (V⊥) with the curvature vector of the field lines. The possibilities encompassed in this simple (but general) equation are quite rich, so we restrict our application of it in this paper to the compressive acceleration of SEPs within CMEs.

  20. Three charged particles in the continuum: astrophysical examples

    NASA Astrophysics Data System (ADS)

    Belyaev, V. B.; Levin, S. B.; Yakovlev, S. L.

    2004-03-01

    We suggest a new adiabatic approach for the description of three charged particles in the continuum. This approach is based on the Coulomb-Fourier transformation of a three-body Hamiltonian, which allows us to develop a scheme, alternative to the Born-Oppenheimer one. The approach appears as an expansion of the kernels of corresponding integral transformations in terms of small mass-ratio parameter. To be specific, the results are presented for the system ppe in the continuum. The wavefunction of such a system is compared with the one which is used for the estimation of the rate for triple reaction p + p + e rarr d + ngr, which takes place as a step of the pp-cycle in the centre of the Sun. The problem of microscopic screening for this particular reaction is discussed.

  1. Photonic crystal devices formed by a charged-particle beam

    DOEpatents

    Lin, Shawn-Yu; Koops, Hans W. P.

    2000-01-01

    A photonic crystal device and method. The photonic crystal device comprises a substrate with at least one photonic crystal formed thereon by a charged-particle beam deposition method. Each photonic crystal comprises a plurality of spaced elements having a composition different from the substrate, and may further include one or more impurity elements substituted for spaced elements. Embodiments of the present invention may be provided as electromagnetic wave filters, polarizers, resonators, sources, mirrors, beam directors and antennas for use at wavelengths in the range from about 0.2 to 200 microns or longer. Additionally, photonic crystal devices may be provided with one or more electromagnetic waveguides adjacent to a photonic crystal for forming integrated electromagnetic circuits for use at optical, infrared, or millimeter-wave frequencies.

  2. Systems and methods of varying charged particle beam spot size

    SciTech Connect

    Chen, Yu-Jiuan

    2014-09-02

    Methods and devices enable shaping of a charged particle beam. A modified dielectric wall accelerator includes a high gradient lens section and a main section. The high gradient lens section can be dynamically adjusted to establish the desired electric fields to minimize undesirable transverse defocusing fields at the entrance to the dielectric wall accelerator. Once a baseline setting with desirable output beam characteristic is established, the output beam can be dynamically modified to vary the output beam characteristics. The output beam can be modified by slightly adjusting the electric fields established across different sections of the modified dielectric wall accelerator. Additional control over the shape of the output beam can be excreted by introducing intentional timing de-synchronization offsets and producing an injected beam that is not fully matched to the entrance of the modified dielectric accelerator.

  3. The ST environment: Expected charged particle radiation levels

    NASA Technical Reports Server (NTRS)

    Stassinopoulos, E. G.

    1978-01-01

    The external (surface incident) charged particle radiation, predicted for the ST satellite at the three different mission altitudes, was determined in two ways: (1) by orbital flux-integration and (2) by geographical instantaneous flux-mapping. The latest standard models of the environment were used in this effort. Magnetic field definitions for three nominal circular trajectories and for the geographic mapping positions were obtained from a current field model. Spatial and temporal variations or conditions affecting the static environment models were considered and accounted for, wherever possible. Limited shielding and dose evaluations were performed for a simple geometry. Results, given in tabular and graphical form, are analyzed, explained, and discussed. Conclusions are included.

  4. Energetic charged particles in Saturn's magnetosphere: Voyager 2 results

    SciTech Connect

    Vogt, R.E.; Chenette, D.L.; Cummings, A.C.; Garrard, T.L.; Stone, E.C.; Schardt, A.W.; Trainor, J.H.; Lal, N.; McDonald, F.B.

    1982-01-29

    Results from the cosmic-ray system on Voyager 2 in Saturn's magnetosphere are presented. During the inbound pass through the outer magnetosphere, the greater than or equal to 0.43-million-electron-volt proton flux was more intense, and both the proton and electron fluxes were more varible, than previously observed. These changes are attributed to the influence on the magnetosphere of variations in the solar wind conditions. Outbound, beyond 18 Saturn radii, impulsive bursts of 0.14- to > 1.0-million-electron-volt electrons were observed. In the inner magnetosphere, the charged particle absorption signatures of Mimas, Enceladus, and Tethys are used to constrain the possible tilt and offset of Saturn's internal magnetic dipole. At approx. 3 Saturn radii, a transient decrease was observed in the electron flux which was not due to Mimas. Characteristics of this decrease suggest the existence of additional material, perhaps another satellite, in the orbit of Mimas.

  5. Energetic Charged Particles in Saturn's Magnetosphere: Voyager 2 Results.

    PubMed

    Vogt, R E; Chenette, D L; Cummings, A C; Garrard, T L; Stone, E C; Schardt, A W; Trainor, J H; Lal, N; McDonald, F B

    1982-01-29

    Results from the cosmic-ray system on Voyager 2 in Saturn's magnetosphere are presented. During the inbound pass through the outer magnetosphere, the >/= 0.43-million-electron-volt proton flux was more intense, and both the proton and electron fluxes were more variable, than previously observed. These changes are attributed to the influence on the magnetosphere of variations in the solar wind conditions. Outbound, beyond 18 Saturn radii, impulsive bursts of 0.14- to > 1.0- million-electron-volt electrons were observed. In the inner magnetosphere, the charged particle absorption signatures of Mimas, Enceladus, and Tethys are used to constrain the possible tilt and offset of Saturn's internal magnetic dipole. At approximately 3 Saturn radii, a transient decrease was observed in the electron flux which was not due to Mimas. Characteristics of this decrease suggest the existence of additional material, perhaps another satellite, in the orbit of Mimas.

  6. Early and late mammalian responses to heavy charged particles

    NASA Technical Reports Server (NTRS)

    Ainsworth, E. J.

    1986-01-01

    This overview summarizes murine results on acute lethality responses, inactivation of marrow CFU-S and intestinal microcolonies, testes weight loss, life span shortening, and posterior lens opacification in mice irradiated with heavy charged particles. RBE-LET relationships for these mammalian responses are compared with results from in vitro studies. The trend is that the maximum RBE for in vivo responses tends to be lower and occurs at a lower LET than for inactivation of V79 and T-1 cells in culture. Based on inactivation cross sections, the response of CFU-S in vivo conforms to expectations from earlier studies with prokaryotic systems and mammalian cells in culture. Effects of heavy ions are compared with fission spectrum neutrons, and the results are consistent with the interpretation that RBEs are lower than for fission neutrons at about the same LET, probably due to differences in track structure.

  7. 21 CFR 892.5050 - Medical charged-particle radiation therapy system.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Medical charged-particle radiation therapy system...-particle radiation therapy system. (a) Identification. A medical charged-particle radiation therapy system...) intended for use in radiation therapy. This generic type of device may include signal analysis and...

  8. 21 CFR 892.5050 - Medical charged-particle radiation therapy system.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Medical charged-particle radiation therapy system...-particle radiation therapy system. (a) Identification. A medical charged-particle radiation therapy system...) intended for use in radiation therapy. This generic type of device may include signal analysis and...

  9. 21 CFR 892.5050 - Medical charged-particle radiation therapy system.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Medical charged-particle radiation therapy system...-particle radiation therapy system. (a) Identification. A medical charged-particle radiation therapy system...) intended for use in radiation therapy. This generic type of device may include signal analysis and...

  10. 21 CFR 892.5050 - Medical charged-particle radiation therapy system.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Medical charged-particle radiation therapy system...-particle radiation therapy system. (a) Identification. A medical charged-particle radiation therapy system...) intended for use in radiation therapy. This generic type of device may include signal analysis and...

  11. 21 CFR 892.5050 - Medical charged-particle radiation therapy system.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Medical charged-particle radiation therapy system...-particle radiation therapy system. (a) Identification. A medical charged-particle radiation therapy system...) intended for use in radiation therapy. This generic type of device may include signal analysis and...

  12. Detection of charged particles in amorphous silicon layers

    SciTech Connect

    Kaplan, S.N.; Morel, J.R.; Mulera, T.A.; Perez-Mendez, V.; Schnurmacher, G.; Street, R.A.

    1985-10-01

    The successful development of radiation detectors made from amorphous silicon could offer the possibility for relatively easy construction of large area position-sensitive detectors. We have conducted a series of measurements with prototype detectors, on signals derived from alpha particles. The measurement results are compared with simple model calculations, and projections are made of potential applications in high-energy and nuclear physics. 4 refs., 7 figs.

  13. Restoring The Azimuthal Symmetry Of Charged Particle Lateral Density In The Range Of KASCADE-Grande

    SciTech Connect

    Sima, O.; Rebel, H.; Apel, W. D.; Bekk, K.; Bozdog, H.; Daumiller, K.; Doll, P.; Engel, R.; Engler, J.; Finger, M.; Gils, H. J.; Haungs, A.; Heck, D.; Huege, T.; Isar, P. G.; Klages, H. O.; Mathes, H. J.; Mayer, H. J.; Milke, J.; Nehls, S.

    2010-11-24

    KASCADE-Grande, an extension of the former KASCADE experiment, is a multi-component Extensive Air Shower (EAS) experiment located in Karlsruhe Institute of Technology (Campus North), Germany. An important observable for analyzing the EAS is the lateral density of charged particles in the intrinsic shower plane. This observable is deduced from the basic information provided by the Grande scintillators - the energy deposit - first in the observation plane, by using a Lateral Energy Correction Function (LECF), then in the intrinsic shower plane, by applying an adequate mapping procedure. In both steps azimuthal.

  14. Pondermotive acceleration of charged particles along the relativistic jets of an accreting blackhole

    NASA Astrophysics Data System (ADS)

    Ebisuzaki, T.; Tajima, T.

    2014-05-01

    Accreting blackholes such as miniquasars and active galactic nuclei can contribute to the highest energy components of intra- (˜1015 eV) galactic and extra-galactic components (˜1020 eV) of cosmic rays. Alfven wave pulses which are excited in the accretion disk around blackholes propagate in relativistic jets. Because of their highly non-linear nature of the waves, charged particles (protons, ions, and electrons) can be accelerated to high energies in relativistic jets in accreting blackhole systems, the central engine of miniquasars and active galactic nuclei.

  15. Charged Particle Environment on Mars - One Mars Year of MSL/RAD Measurements

    NASA Astrophysics Data System (ADS)

    Ehresmann, B.; Hassler, D.; Zeitlin, C. J.; Kohler, J.; Wimmer-Schweingruber, R. F.; Brinza, D. E.; Rafkin, S. C.; Reitz, G.; Appel, J. K.; Guo, J.; Lohf, H.; Burmeister, S.; Matthiae, D.; Boettcher, S. I.; Boehm, E.; Martin-Garcia, C.

    2015-12-01

    The Mars Science Laboratory's Radiation Assessment Detector (MSL/RAD) has been conducting measurements of the ionizing radiation field on the Martian surface since August 2012. This field is mainly dominated by Galactic Cosmic Rays (GCRs) and their interactions with the atoms in the atmosphere and soil. This yields a radiation environment consisting of a wide variety of particles and energies which, at high energies, is dominated by charged particles, e.g., ions, and their isotopes, electrons, and others. Over the course of the first Martian year (~2 Earth years) of the MSL mission, the radiation field was mainly modulated by two influences: the seasonal pressure cycle at Gale crater; and the variation of the impeding GCR flux due to changes in the solar activity. Here, we present charged particle fluxes measured over a 1000 days and analyze how the more-abundant ion species vary over that time frame. A second major influence to the radiation field can be the contribution from Solar Energetic Particle (SEP) events. In particular, the Martian surface proton flux can be enhanced by orders of magnitude on short time scales during strong events. Here, we present measurements of the proton fluxes during the SEP events MSL/RAD has so far directly measured in Gale crater.

  16. Angular Distribution of Charged Particles in the Atmosphere- Results of the ADAM Experiment on BEXUS 19

    NASA Astrophysics Data System (ADS)

    Martensen, S.; Brudern, M.; Christiansen, F.; Koberle, M.; Trautwein, D.; Wraase, S.; Bottcher, S.; Burmeister, S.; Heber, B.; Wimmer-Schweingruber, R.

    2015-09-01

    Particle showers, which produce a large number of secondary particles, are generated by the interaction of high-energy cosmic ray particles with the Earth's atmosphere. The Team ADAM (Angular Distribution of charged partides - Atmosphere Measurement) has flown an experiment to measure the altitude- dependent angular distribution of secondary charged particles on a stratospheric balloon within the REXUS/BEXUS programme in October 2014. We designed a sensor head consisting of 16 planar silicon semi-conductor detectors (SSDs), which allowed us to determine the zenith-angle of individual particles by coincidence measurements. After a year of development and testing, on October 9th the instrument performed measurements for 4 hours in an altitude of 27 km in northern Sweden. In this contribution measurements performed during the flight in comparison to ones obtained on ground will be presented. On the one hand we focus on the count and dose rate profiles as functions of residual pressure, on the other hand we discuss the angular distribution below and above the PFOTZERMaximum.

  17. Charged-particle rapidity density in Au+Au collisions in a quark combination model

    NASA Astrophysics Data System (ADS)

    Shao, Feng-Lan; Yao, Tao; Xie, Qu-Bing

    2007-03-01

    Rapidity/pseudorapidity densities for charged particles and their centrality, rapidity, and energy dependence in Au+Au collisions at the Relativistic Heavy Ion Collider are studied in a quark combination model. Using a Gaussian-type rapidity distribution for constituent quarks as a result of Landau hydrodynamic evolution, the data at sNN=130,200 GeV at various centralities in full pseudorapidity range are well described, and the charged-particle multiplicities are reproduced as functions of the number of participants. The energy dependence of the shape of the dNch/dη distribution is also described at various collision energies sNN=200,130,62.4 GeV in central collisions with same value of parameters except 19.6 GeV. The calculated rapidity distributions and yields for the charged pions and kaons in central Au+Au collisions at sNN=200 GeV are compared with experimental data of the BRAHMS Collaboration.

  18. Measurement of charged particle yields from therapeutic beams in view of the design of an innovative hadrontherapy dose monitor

    NASA Astrophysics Data System (ADS)

    Battistoni, G.; Bellini, F.; Bini, F.; Collamati, F.; Collini, F.; De Lucia, E.; Durante, M.; Faccini, R.; Ferroni, F.; Frallicciardi, P. M.; La Tessa, C.; Marafini, M.; Mattei, I.; Miraglia, F.; Morganti, S.; Ortega, P. G.; Patera, V.; Piersanti, L.; Pinci, D.; Russomando, A.; Sarti, A.; Schuy, C.; Sciubba, A.; Senzacqua, M.; Solfaroli Camillocci, E.; Vanstalle, M.; Voena, C.

    2015-02-01

    Particle Therapy (PT) is an emerging technique, which makes use of charged particles to efficiently cure different kinds of solid tumors. The high precision in the hadrons dose deposition requires an accurate monitoring to prevent the risk of under-dosage of the cancer region or of over-dosage of healthy tissues. Monitoring techniques are currently being developed and are based on the detection of particles produced by the beam interaction into the target, in particular: charged particles, result of target and/or projectile fragmentation, prompt photons coming from nucleus de-excitation and back-to-back γ s, produced in the positron annihilation from β + emitters created in the beam interaction with the target. It has been showed that the hadron beam dose release peak can be spatially correlated with the emission pattern of these secondary particles. Here we report about secondary particles production (charged fragments and prompt γ s) performed at different beam and energies that have a particular relevance for PT applications: 12C beam of 80 MeV/u at LNS, 12C beam 220 MeV/u at GSI, and 12C, 4He, 16O beams with energy in the 50-300 MeV/u range at HIT. Finally, a project for a multimodal dose-monitor device exploiting the prompt photons and charged particles emission will be presented.

  19. Chaotic motion of charged particles in toroidal magnetic configurations

    SciTech Connect

    Cambon, Benjamin; Leoncini, Xavier; Vittot, Michel; Dumont, Rémi; Garbet, Xavier

    2014-09-01

    We study the motion of a charged particle in a tokamak magnetic field and discuss its chaotic nature. Contrary to most of recent studies, we do not make any assumption on any constant of the motion and solve numerically the cyclotron gyration using Hamiltonian formalism. We take advantage of a symplectic integrator allowing us to make long-time simulations. First considering an idealized magnetic configuration, we add a nongeneric perturbation corresponding to a magnetic ripple, breaking one of the invariant of the motion. Chaotic motion is then observed and opens questions about the link between chaos of magnetic field lines and chaos of particle trajectories. Second, we return to an axisymmetric configuration and tune the safety factor (magnetic configuration) in order to recover chaotic motion. In this last setting with two constants of the motion, the presence of chaos implies that no third global constant exists, we highlight this fact by looking at variations of the first order of the magnetic moment in this chaotic setting. We are facing a mixed phase space with both regular and chaotic regions and point out the difficulties in performing a global reduction such as gyrokinetics.

  20. Chaotic motion of charged particles in toroidal magnetic configurations.

    PubMed

    Cambon, Benjamin; Leoncini, Xavier; Vittot, Michel; Dumont, Rémi; Garbet, Xavier

    2014-09-01

    We study the motion of a charged particle in a tokamak magnetic field and discuss its chaotic nature. Contrary to most of recent studies, we do not make any assumption on any constant of the motion and solve numerically the cyclotron gyration using Hamiltonian formalism. We take advantage of a symplectic integrator allowing us to make long-time simulations. First considering an idealized magnetic configuration, we add a nongeneric perturbation corresponding to a magnetic ripple, breaking one of the invariant of the motion. Chaotic motion is then observed and opens questions about the link between chaos of magnetic field lines and chaos of particle trajectories. Second, we return to an axisymmetric configuration and tune the safety factor (magnetic configuration) in order to recover chaotic motion. In this last setting with two constants of the motion, the presence of chaos implies that no third global constant exists, we highlight this fact by looking at variations of the first order of the magnetic moment in this chaotic setting. We are facing a mixed phase space with both regular and chaotic regions and point out the difficulties in performing a global reduction such as gyrokinetics.