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Sample records for medium energy proton

  1. Signature for g bosons from medium energy proton scattering experiments

    SciTech Connect

    Kuyucak, S.

    1993-10-01

    We apply the recently developed algebraic (1/N expansion) scattering formalism to medium energy proton scattering from {sup 154}Sm and {sup 176}Yb. The nuclear structure effects in this formalism are described by the interacting boson model generalized to arbitrary interactions and types of bosons i.e. s,d,g, etc. We find that, in the sd boson model, a consistent description of cross sections is possible only for the 0{sup +} and 2{sup +} states. The failure of the model with regard to the 4{sup +} states indicates that the effective hexadecapole operator used in the sd model is inadequate. In contrast, the data for scattering to the 0{sup +}, 2{sup +} and 4{sup +} states could be consistently described in the sdg boson model. The spectroscopic data for the low-lying levels usually can not distinguish between the sd and sdg models due to renormalization of parameters, and one has to look at high spin or energy data for evidence of g bosons. The inelastic proton scattering experiments, on the other hand, directly probe the wave functions, and hence could provide a signature for g bosons even in the ground band states.

  2. Low-energy cosmic ray protons from nuclear interactions of cosmic rays with the interstellar medium.

    NASA Technical Reports Server (NTRS)

    Wang, H. T.

    1973-01-01

    The intensity of low-energy (less than 100 MeV) protons from nuclear interactions of higher-energy (above 100 MeV) cosmic rays with the interstellar medium is calculated. The resultant intensity in the 10- to 100-MeV range is larger by a factor of 3-5 than the observed proton intensity near earth. The calculated intensity from nuclear interactions constitutes a lower limit on the actual proton intensity in interstellar space.

  3. Medium energy proton radiation damage to (AlGa)As-GaAs solar cells

    NASA Technical Reports Server (NTRS)

    Loo, R. Y.; Kamath, G. S.; Knechtli, R. C.

    1982-01-01

    The performance of (AlGa)As-GaAs solar cells irradiated by medium energy 2, 5, and 10 MeV protons was evaluated. The Si cells without coverglass and a number of GaAs solar cells with 12 mil coverglass were irradiated simultaneously with bare GaAs cells. The cell degradation is directly related to the penetration of depth of protons with GaAs. The influence of periodic and continuous thermal annealing on the GaAs solar cells was investigated.

  4. A new medium energy beam transport line for the proton injector of AGS-RHIC

    SciTech Connect

    Okamura, M.; Briscoe, B.; Fite, J.; LoDestro, V.; Raparia, D.; Ritter, J.; Hayashizaki, N.

    2010-09-12

    In Brookhaven National Laboratory (BNL), a 750 keV medium energy beam transport line between the 201 MHz 750 keV proton RFQ and the 200 MeV Alvarez DTL is being modified to get a better transmission of the beam. Within a tight space, high field gradient quadrupoles (65 Tm) and newly designed steering magnets (6.5 mm in length) will be installed considering the cross-talk effects. Also a new half wave length 200 MHz buncher is being prepared. The beam commissioning will be done in this year. To enhance the performance of the proton linacs, the MEBT is being modified. New quadrupole magnets, steering magnets and a half wave length buncher as shown in Figure 7 will be installed and be commissioned soon.

  5. Investigation of proton induced reactions on niobium at low and medium energies

    NASA Astrophysics Data System (ADS)

    Ditrói, F.; Hermanne, A.; Corniani, E.; Takács, S.; Tárkányi, F.; Csikai, J.; Shubin, Yu. N.

    2009-10-01

    Niobium is a metal with important technological applications: use as alloying element to increase strength of super alloys, as thin layer for tribological applications, as superconductive material, in high temperature engineering systems, etc. In the frame of a systematic study of activation cross-sections of charged particle induced reactions on structural materials proton induced excitation functions on Nb targets were determined with the aim of applications in accelerator and reactor technology and for thin layer activation (TLA). The charged particle activation cross-sections on this element are also important for yield calculation of medical isotope production ( 88,89Zr, 86,87,88Y) and for dose estimation in PET targetry. As niobium is a monoisotopic element it is an ideal target material to test nuclear reaction theories. We present here the experimental excitation functions of 93Nb(p,x) 90,93mMo, 92m,91m,90Nb, 88,89Zr and 88Y in the energy range 0-37 MeV. The results were compared with the theoretical cross-sections calculated by means of the code ALICE-IPPE, EMPIRE-3, TALYS and with the literature data. The theory reproduces the shape of the measured results well and magnitude is also acceptable. Thick target yields calculated from our fitted cross-section give reliable estimations for production of medically relevant radioisotopes and for dose estimation in accelerator technology.

  6. Proton Reaction Data Library for Nuclear Activation (Medium Energy Nuclear Data Library.)

    2002-03-01

    Version 00 GROUPXS does file handling and processing of the double-differential continuum-emission cross sections stored in the new MF6 format of ENDF/VI. It treats the energy-angle data that are supposed to be represented by a Legendre-polynomial expansion in the center-of-mass system and can do the following: (1) Conversion of MF6 data from center-of-mass system to the laboratory system, with the possibility to continue the calculation with the options (2), (3), and (4). (2) Conversion ofmore » Legendre-polynomial representation into point-wise angular data, in MF6 format. (3) Conversion of data from MF6 into MF4 + MF5 (ENDF-V). (4) Calculation of group constants, scattering matrices and transfer matrices for arbitrary group structures with a fusion micro-flux weighting spectrum (PN-approximation). The code treats only continuum reaction types that are stored in the MF6 format with the restrictions as specified for the European Fusion File (EFF1). These restrictions are not inconvenient for the purpose of fusion neutronics calculations and they facilitate relatively simple processing . This neutron reaction data library can be used for nuclear activation and transmutation applications at energies up to 100 MeV.« less

  7. Calculation of the absorbed dose and dose equivalent induced by medium energy neutrons and protons and comparison with experiment

    NASA Technical Reports Server (NTRS)

    Armstrong, T. W.; Bishop, B. L.

    1972-01-01

    Monte Carlo calculations have been carried out to determine the absorbed dose and dose equivalent for 592-MeV protons incident on a cylindrical phantom and for neutrons from 580-MeV proton-Be collisions incident on a semi-infinite phantom. For both configurations, the calculated depth dependence of the absorbed dose is in good agreement with experimental data.

  8. Tailoring medium energy proton beam to induce low energy nuclear reactions in ⁸⁶SrCl₂ for production of PET radioisotope ⁸⁶Y.

    PubMed

    Medvedev, Dmitri G; Mausner, Leonard F; Pile, Philip

    2015-07-01

    This paper reports results of experiments at Brookhaven Linac Isotope Producer (BLIP) aiming to investigate effective production of positron emitting radioisotope (86)Y by the low energy (86)Sr(p,n) reaction. BLIP is a facility at Brookhaven National Laboratory designed for the proton irradiation of the targets for isotope production at high and intermediate proton energies. The proton beam is delivered by the Linear Accelerator (LINAC) whose incident energy is tunable from 200 to 66 MeV in approximately 21 MeV increments. The array was designed to ensure energy degradation from 66 MeV down to less than 20 MeV. Aluminum slabs were used to degrade the proton energy down to the required range. The production yield of (86)Y (1.2+/-0.1 mCi (44.4+/-3.7) MBq/μAh) and ratio of radioisotopic impurities was determined by assaying an aliquot of the irradiated (86)SrCl2 solution by gamma spectroscopy. The analysis of energy dependence of the (86)Y production yield and the ratios of radioisotopic impurities has been used to adjust degrader thickness. Experimental data showed substantial discrepancies in actual energy propagation compared to energy loss calculations.

  9. Experimental medium energy physics

    SciTech Connect

    Barnes, P.D.

    1990-01-01

    This report discusses the following topics: search for the H-dibaryon at the AGS; weak interaction studies with hypernuclear decays at the AGS; search for the {xi}(2230) at LEAR; relativistic proton-nucleus and heavy ion-nucleus collisions at the SPS; hyperon-antihyperon production studies at LEAR; photoproduction of strange CEBAF; and experiment design development.

  10. Experimental Medium Energy Physics

    SciTech Connect

    Not Available

    1992-01-01

    This report discusses the following topics: Search for the H Dibaryon at the AGS; hypernuclear weak decay studies at the LAGS; search for strangelets using the 2 GeV/c beam line; experiment to detect double lambda hypernuclei; hyperon photoproduction at CEBAF; the region 1 drift chambers for the CLAS spectrometer; parity violating electron scattering from the proton: the G{sup 0}experiment at CEBAF; and relativistic heavy ion - nucleus collisions at the SPS.

  11. A vertical-beam target station and high-power targetry for the cyclotron production of radionuclides with medium energy protons

    NASA Astrophysics Data System (ADS)

    Steyn, G. F.; Vermeulen, C.; Botha, A. H.; Conradie, J. L.; Crafford, J. P. A.; Delsink, J. L. G.; Dietrich, J.; du Plessis, H.; Fourie, D. T.; Kormány, Z.; van Niekerk, M. J.; Rohwer, P. F.; Stodart, N. P.; de Villiers, J. G.

    2013-11-01

    A vertical-beam target station (VBTS) is described to exploit the high-intensity proton beams delivered by the upgraded separated-sector cyclotron of iThemba LABS for the production of longer-lived, high value radionuclides such as 22Na, 68Ge and 82Sr. Aspects of the targetry are discussed as well as a beam splitter, which makes it possible to perform radionuclide production bombardments simultaneously in two irradiation vaults. With tandem targets in two stations, four targets can be bombarded simultaneously. The delivery of 66 MeV proton beams of higher intensity has been realized by installing fixed frequency, flat-top RF resonators on both the main cyclotron and an injector cyclotron. The increase in beam intensity also required new non-destructive diagnostic components in the relevant high-energy beamlines. An overview is given of the current radionuclide production target stations, their similarities and differences and the role of the VBTS in the production programme.

  12. Cross sections for the production of residual nuclides by low- and medium-energy protons from the target elements C, N, O, Mg, Al, Si, Ca, Ti, V, Mn, Fe, Co, Ni, Cu, Sr, Y, Zr, Nb, Ba and Au

    NASA Astrophysics Data System (ADS)

    Michel, R.; Bodemann, R.; Busemann, H.; Daunke, R.; Gloris, M.; Lange, H.-J.; Klug, B.; Krins, A.; Leya, I.; Lüpke, M.; Neumann, S.; Reinhardt, H.; Schnatz-Büttgen, M.; Herpers, U.; Schiekel, Th.; Sudbrock, F.; Holmqvist, B.; Condé, H.; Malmborg, P.; Suter, M.; Dittrich-Hannen, B.; Kubik, P.-W.; Synal, H.-A.; Filges, D.

    1997-07-01

    Cross sections for residual nuclide production by p-induced reactions were measured from thresholds up to 2.6 GeV using accelerators at CERN/Geneve, IPN/Orsay, KFA/Jülich, LANL/Los Alamos, LNS/Saclay, PSI/Villigen, TSL/Uppsala, LUC/Louvain La Neuve. The target elements C, N, O, Mg, Al, Si, Ca, Ti, V, Mn, Fe, Co, Ni, Cu, Sr, Y, Zr, Nb, Ba and Au were investigated. Residual nuclides were measured by X- and γ-spectrometry and by Accelerator Mass Spectrometry (AMS). The measured cross sections were corrected for interfering secondary particles in experiments with primary proton energies above 200 MeV. Our consistent database covers presently ca 550 nuclear reactions and contains nearly 15000 individual cross sections of which about 10000 are reported here for the first time. They provide a basis for model calculations of the production of cosmogenic nuclides in extraterrestrial matter by solar and galactic cosmic ray protons. They are of importance for many other applications in which medium energy nuclear reactions have to be considered ranging from astrophysics over space and environmental sciences to accelerator technology and accelerator-based nuclear waste transmutation and energy amplification. The experimental data are compared with theoretical ones based on calculations using an INC/E model in form of the HETC/KFA2 code and on the hybrid model of preequilibrium reactions in form of the AREL code.>

  13. Low-Energy Proton Testing Methodology

    NASA Technical Reports Server (NTRS)

    Pellish, Jonathan A.; Marshall, Paul W.; Heidel, David F.; Schwank, James R.; Shaneyfelt, Marty R.; Xapsos, M.A.; Ladbury, Raymond L.; LaBel, Kenneth A.; Berg, Melanie; Kim, Hak S.; Phan, Anthony; Friendlich, M.R.; Rodbell, Kenneth P.; Hakey, Mark C.; Dodd, Paul E.; Reed, Robert A.; Weller, Robert A.; Mendenhall, Marcus H.; Sierawski, B.D.

    2009-01-01

    Use of low-energy protons and high-energy light ions is becoming necessary to investigate current-generation SEU thresholds. Systematic errors can dominate measurements made with low-energy protons. Range and energy straggling contribute to systematic error. Low-energy proton testing is not a step-and-repeat process. Low-energy protons and high-energy light ions can be used to measure SEU cross section of single sensitive features; important for simulation.

  14. [Medium energy meson research

    SciTech Connect

    Crowe, K.M.

    1992-01-01

    The activities of this group are primarily concerned with experiments using the Crystal Barrel Detector. This detector is installed and operating at the Low Energy Antiproton Ring (LEAR) at CERN. QCD, the modem theory of the strong interaction, is reasonably well understood at high energies, but unfortunately, low-energy QCD is still not well understood, and is far from being adequately tested. The Crystal Barrel experiments are designed to provide some of the tests. The basic line of research involves meson spectroscopy, analyses bearing on the quark and/or gluon content of nuclear states, and the exploration of mechanisms and rules which govern p[bar p] annihilation dynamics. The Crystal Barrel Detector detects and identifies charged and neutral particles with a geometric acceptance close to 100%. The principal component of the detector is an array of 1,380 CsI(TI) crystals. These crystals surround a Jet Drift Chamber (JDC), located in a 1.5 Tesla magnetic field, which measures the momentum and dE/dx of charged particles. One of the very interesting physics goals of the detector is a search for exotic mesonic states -- glueballs and hybrids. Annihilation at rest will be studied with both liquid and gaseous hydrogen targets. The gaseous target offers the possibility of triggering on atomic L-shell X rays so that specific initial angular momentum states can be studied.These topics as well as other related topics are discussed in this report.

  15. [Medium energy meson research

    SciTech Connect

    Crowe, K.M.

    1992-12-01

    The activities of this group are primarily concerned with experiments using the Crystal Barrel Detector. This detector is installed and operating at the Low Energy Antiproton Ring (LEAR) at CERN. QCD, the modem theory of the strong interaction, is reasonably well understood at high energies, but unfortunately, low-energy QCD is still not well understood, and is far from being adequately tested. The Crystal Barrel experiments are designed to provide some of the tests. The basic line of research involves meson spectroscopy, analyses bearing on the quark and/or gluon content of nuclear states, and the exploration of mechanisms and rules which govern p{bar p} annihilation dynamics. The Crystal Barrel Detector detects and identifies charged and neutral particles with a geometric acceptance close to 100%. The principal component of the detector is an array of 1,380 CsI(TI) crystals. These crystals surround a Jet Drift Chamber (JDC), located in a 1.5 Tesla magnetic field, which measures the momentum and dE/dx of charged particles. One of the very interesting physics goals of the detector is a search for exotic mesonic states -- glueballs and hybrids. Annihilation at rest will be studied with both liquid and gaseous hydrogen targets. The gaseous target offers the possibility of triggering on atomic L-shell X rays so that specific initial angular momentum states can be studied.These topics as well as other related topics are discussed in this report.

  16. Developing a phenomenological model of the proton trajectory within a heterogeneous medium required for proton imaging.

    PubMed

    Fekete, Charles-Antoine Collins; Doolan, Paul; Dias, Marta F; Beaulieu, Luc; Seco, Joao

    2015-07-01

    To develop an accurate phenomenological model of the cubic spline path estimate of the proton path, accounting for the initial proton energy and water equivalent thickness (WET) traversed. Monte Carlo (MC) simulations were used to calculate the path of protons crossing various WET (10-30 cm) of different material (LN300, water and CB2-50% CaCO3) for a range of initial energies (180-330 MeV). For each MC trajectory, cubic spline trajectories (CST) were constructed based on the entrance and exit information of the protons and compared with the MC using the root mean square (RMS) metric. The CST path is dependent on the direction vector magnitudes (|P0,1|). First, |P0,1| is set to the proton path length (with factor Λ(Norm)(0,1) = 1.0). Then, two optimal factor Λ(0,1) are introduced in |P0,1|. The factors are varied to minimize the RMS difference with MC paths for every configuration. A set of Λ(opt)(0,1) factors, function of WET/water equivalent path length (WEPL), that minimizes the RMS are presented. MTF analysis is then performed on proton radiographs of a line-pair phantom reconstructed using the CST trajectories. Λ(opt)(0,1) was fitted to the WET/WEPL ratio using a quadratic function (Y = A + BX(2) where A = 1.01,0.99, B = 0.43,-  0.46 respectively for Λ(opt)(0), Λ(opt)(1)). The RMS deviation calculated along the path, between the CST and the MC, increases with the WET. The increase is larger when using Λ(Norm)(0,1) than Λ(opt)(0,1) (difference of 5.0% with WET/WEPL = 0.66). For 230/330 MeV protons, the MTF10% was found to increase by 40/16% respectively for a thin phantom (15 cm) when using the Λ(opt)(0,1) model compared to the Λ(Norm)(0,1) model. Calculation times for Λ(opt)(0,1) are scaled down compared to MLP and RMS deviation are similar within standard deviation.B ased on the results of this study, using CST with the Λ(opt)(0,1) factors reduces the RMS deviation and increases the spatial resolution when reconstructing proton

  17. Developing a phenomenological model of the proton trajectory within a heterogeneous medium required for proton imaging.

    PubMed

    Fekete, Charles-Antoine Collins; Doolan, Paul; Dias, Marta F; Beaulieu, Luc; Seco, Joao

    2015-07-01

    To develop an accurate phenomenological model of the cubic spline path estimate of the proton path, accounting for the initial proton energy and water equivalent thickness (WET) traversed. Monte Carlo (MC) simulations were used to calculate the path of protons crossing various WET (10-30 cm) of different material (LN300, water and CB2-50% CaCO3) for a range of initial energies (180-330 MeV). For each MC trajectory, cubic spline trajectories (CST) were constructed based on the entrance and exit information of the protons and compared with the MC using the root mean square (RMS) metric. The CST path is dependent on the direction vector magnitudes (|P0,1|). First, |P0,1| is set to the proton path length (with factor Λ(Norm)(0,1) = 1.0). Then, two optimal factor Λ(0,1) are introduced in |P0,1|. The factors are varied to minimize the RMS difference with MC paths for every configuration. A set of Λ(opt)(0,1) factors, function of WET/water equivalent path length (WEPL), that minimizes the RMS are presented. MTF analysis is then performed on proton radiographs of a line-pair phantom reconstructed using the CST trajectories. Λ(opt)(0,1) was fitted to the WET/WEPL ratio using a quadratic function (Y = A + BX(2) where A = 1.01,0.99, B = 0.43,-  0.46 respectively for Λ(opt)(0), Λ(opt)(1)). The RMS deviation calculated along the path, between the CST and the MC, increases with the WET. The increase is larger when using Λ(Norm)(0,1) than Λ(opt)(0,1) (difference of 5.0% with WET/WEPL = 0.66). For 230/330 MeV protons, the MTF10% was found to increase by 40/16% respectively for a thin phantom (15 cm) when using the Λ(opt)(0,1) model compared to the Λ(Norm)(0,1) model. Calculation times for Λ(opt)(0,1) are scaled down compared to MLP and RMS deviation are similar within standard deviation.B ased on the results of this study, using CST with the Λ(opt)(0,1) factors reduces the RMS deviation and increases the spatial resolution when reconstructing proton

  18. ACCELERATING POLARIZED PROTONS TO HIGH ENERGY.

    SciTech Connect

    BAI, M.; AHRENS, L.; ALEKSEEV, I.G.; ALESSI, J.; BEEBE-WANG, J.; BLASKIEWICZ, M.; BRAVAR, A.; BRENNAN, J.M.; BRUNO, D.; BUNCE, G.; ET AL.

    2006-10-02

    The Relativistic Heavy Ion Collider (RHIC) is designed to provide collisions of high energy polarized protons for the quest of understanding the proton spin structure. Polarized proton collisions at a beam energy of 100 GeV have been achieved in RHIC since 2001. Recently, polarized proton beam was accelerated to 250 GeV in RHIC for the first time. Unlike accelerating unpolarized protons, the challenge for achieving high energy polarized protons is to fight the various mechanisms in an accelerator that can lead to partial or total polarization loss due to the interaction of the spin vector with the magnetic fields. We report on the progress of the RHIC polarized proton program. We also present the strategies of how to preserve the polarization through the entire acceleration chain, i.e. a 200 MeV linear accelerator, the Booster, the AGS and RHIC.

  19. Fisk-Gloeckler Suprathermal Proton Spectrum in the Heliosheath and the Local Interstellar Medium

    NASA Technical Reports Server (NTRS)

    Cooper, John F.; Kasprzak, W. T.; Mahaffy, P. R.; Niemann, H. B.; Hartle, R. E.; Paschalidis, N.; Chornay, D.; Coplan, M.; Johnson, R. E.

    2010-01-01

    Convergence of suprathermal keV-MeV proton and ion spectra approximately to the Fisk-Gloeckler (F-G) form j(E) = j(sub 0) E(sup -1.5) in Voyager land 2 heliosheath measurements is suggestive of distributed acceleration in Kolmogorov turbulence which may extend well beyond the heliopause into the local interstellar medium (LISM). Turbulence of this type is already indicated by interstellar radio scintillation measurements of electron density power spectra. Previously published extrapolations (Cooper et al., 2003, 2006) of the LISM proton spectrum from eV to GeV energies are highly consistent with the F-G power-law and further indicative of such turbulence and LISM effectiveness of the F-G cascade acceleration process. The LISM pressure computed from this spectrum well exceeds that from current estimates for the LISM magnetic field, so exchange of energy between the protons and the magnetic field would likely have a strong role in evolution of the turbulence as per the F-G theory and as long ago proposed for cosmic ray energies by Parker and others. Pressure-dependent estimates of the LISM field strength should not ignore this potentially strong and even dominant contribution from the plasma. Presence of high-beta suprathermal plasma on LISM field lines could significantly affect interactions with the heliospheric outer boundary region and might potentially account for distributed and more discrete features in ongoing measurements of energetic neutral emission from the Interstellar Boundary Explorer (IBEX) mission.

  20. Medium energy nuclear physics research

    NASA Astrophysics Data System (ADS)

    Peterson, G. A.; Dubach, J. F.; Hicks, R. S.; Miskimen, R. A.

    1991-06-01

    Research on the following topics is discussed: Transverse from factors of (Sn-117); Elastic magnetic electron scattering from C-13 at Q(exp 2) = 1 GeV(exp 2)/sq c; A reanalysis of C-13 elastic scattering; Deuteron threshold electrodisintegration; Measurement of the elastic magnetic form factor of He-3 at high momentum transfer; Coincidence measurement of the D(electron, electron proton) cross section at low excitation energy and high momentum transfer; Measurement of the quadrupole contribution to the N yields Delta excitation; measurement of the x-, Q(exp 2)-, and A-dependence of R = sigma sub L/sigma sub T; The PEGASYS project; PEP beam-gas event analysis; Plans for other experiments at SLAC, i.e., polarized electron scattering on polarized nuclei; Experiment PR-89-015 (study of coincidence reactions in the dip and delta resonance regions); Experiment PR-89-031 (multi-nulceon knockout using the CLAS detector); Drift chamber tests; A memorandum of understanding and test experiments; Photoprotons from (exp 10)B; And hadronic electroproduction at LEP.

  1. Medium energy elementary particle physics

    SciTech Connect

    Not Available

    1991-01-01

    This report discusses the following topics: muon beam development at LAMPF; muon physics; a new precision measurement of the muon g-2 value; measurement of the spin-dependent structure functions of the neutron and proton; and meson factories. (LSP)

  2. Studies in medium energy physics

    SciTech Connect

    Green, A.; Hoffmann, G.W.; McDonough, J.; Purcell, M.J.; Ray, R.L.; Read, D.E.; Worn, S.D.

    1991-12-01

    This document constitutes the (1991--1992) technical progress report and continuation proposal for the ongoing medium energy nuclear physics research program supported by the US Department of Energy through special Research Grant DE-FG05-88ER40444. The experiments discussed are conducted at the Los Alamos National Laboratory's (LANL) Clinton P. Anderson Meson Physics Facility (LAMPF) and the Alternating Gradient Synchrotron (AGS) facility of the Brookhaven National Laboratory (BNL). The overall motivation for the work discussed in this document is driven by three main objectives: (1) provide hadron-nucleon and hadron-nucleus scattering data which serve to facilitate the study of effective two-body interactions, test (and possibly determine) nuclear structure, and help study reaction mechanisms and dynamics; (2) provide unique, first-of-a-kind exploratory'' hadron-nucleus scattering data in the hope that such data will lead to discovery of new phenomena and new physics; and (3) perform precision tests of fundamental interactions, such as rare decay searches, whose observation would imply fundamental new physics.

  3. Elastic Proton Scattering of Medium Mass Nuclei from Coupled-Cluster Theory

    SciTech Connect

    Hagen, G.; MichelN.,

    2012-01-01

    Using coupled-cluster theory and interactions from chiral effective field theory, we compute overlap functions for transfer and scattering of low-energy protons on the target nucleus 40Ca. Effects of three-nucleon forces are included phenomenologically as in-medium two-nucleon interactions. Using known asymptotic forms for one-nucleon overlap functions we derive a simple and intuitive way of computing scattering observables such as elastic scattering phase shifts and cross sections. As a first application and proof of principle, we compute phase shifts and differential interaction cross sections at energies of 9.6 and 12.44 MeV and compare with experimental data. Our computed diffraction minima are in fair agreement with experimental results, while we tend to overestimate the cross sections at large scattering angles.

  4. On the high energy proton spectrum measurements

    NASA Technical Reports Server (NTRS)

    Ellsworth, R. W.; Ito, A.; Macfall, J.; Siohan, F.; Streitmatter, R. E.; Tonwar, S. C.; Vishwanath, P. R.; Yodh, G. B.; Balasubrahmanyan, V. K.

    1977-01-01

    The steepening of the proton spectrum beyond 1000 GeV and the rise in inelastic cross sections between 20 and 600 GeV observed by the PROTON-1-2-3 satellite experiments were explained by systematic effects of energy dependent albedo (backscatter) from the calorimeter.

  5. Protons @ interfaces: implications for biological energy conversion.

    PubMed

    Mulkidjanian, Armen Y; Heberle, Joachim; Cherepanov, Dmitry A

    2006-08-01

    The review focuses on the anisotropy of proton transfer at the surface of biological membranes. We consider (i) the data from "pulsed" experiments, where light-triggered enzymes capture or eject protons at the membrane surface, (ii) the electrostatic properties of water at charged interfaces, and (iii) the specific structural attributes of proton-translocating enzymes. The pulsed experiments revealed that proton exchange between the membrane surface and the bulk aqueous phase takes as much as about 1 ms, but could be accelerated by added mobile pH-buffers. Since the accelerating capacity of the latter decreased with the increase in their electric charge, it was concluded that the membrane surface is separated from the bulk aqueous phase by a barrier of electrostatic nature. The barrier could arise owing to the water polarization at the negatively charged membrane surface. The barrier height depends linearly on the charge of penetrating ions; for protons, it has been estimated as about 0.12 eV. While the proton exchange between the surface and the bulk aqueous phase is retarded by the interfacial barrier, the proton diffusion along the membrane, between neighboring enzymes, takes only microseconds. The proton spreading over the membrane is facilitated by the hydrogen-bonded networks at the surface. The membrane-buried layers of these networks can eventually serve as a storage/buffer for protons (proton sponges). As the proton equilibration between the surface and the bulk aqueous phase is slower than the lateral proton diffusion between the "sources" and "sinks", the proton activity at the membrane surface, as sensed by the energy transducing enzymes at steady state, might deviate from that measured in the adjoining water phase. This trait should increase the driving force for ATP synthesis, especially in the case of alkaliphilic bacteria.

  6. Highly flexible, proton-conductive silicate glass electrolytes for medium-temperature/low-humidity proton exchange membrane fuel cells.

    PubMed

    Lee, Hyeon-Ji; Kim, Jung-Hwan; Won, Ji-Hye; Lim, Jun-Muk; Hong, Young Taik; Lee, Sang-Young

    2013-06-12

    We demonstrate highly flexible, proton-conductive silicate glass electrolytes integrated with polyimide (PI) nonwoven fabrics (referred to as "b-SS glass electrolytes") for potential use in medium-temperature/low-humidity proton exchange membrane fuel cells (PEMFCs). The b-SS glass electrolytes are fabricated via in situ sol-gel synthesis of 3-trihydroxysilyl-1-propanesulfonic acid (THPSA)/3-glycidyloxypropyl trimethoxysilane (GPTMS) mixtures inside PI nonwoven substrates that serve as a porous reinforcing framework. Owing to this structural uniqueness, the b-SS glass electrolytes provide noticeable improvements in mechanical bendability and membrane thickness, in comparison to typical bulk silicate glass electrolytes that are thick and easily fragile. Another salient feature of the b-SS glass electrolytes is the excellent proton conductivity at harsh measurement conditions of medium temperature/low humidity, which is highly important for PEMFC-powered electric vehicle applications. This beneficial performance is attributed to the presence of a highly interconnected, proton-conductive (THPSA/GPTMS-based) silicate glass matrix in the PI reinforcing framework. Notably, the b-SS glass electrolyte synthesized from THPSA/GPTMS = 9/1 (mol/mol) exhibits a higher proton conductivity than water-swollen sulfonated polymer electrolyte membranes (here, sulfonated poly(arylene ether sulfone) and Nafion are chosen as control samples). This intriguing behavior in the proton conductivity of the b-SS glass electrolytes is discussed in great detail by considering its structural novelty and Grotthuss mechanism-driven proton migration that is strongly affected by ion exchange capacity (IEC) values and also state of water.

  7. Medium energy heavy ion operations at RHIC

    SciTech Connect

    Drees, K.A.; Ahrens, L.; Bai, M.; Beebe-Wang, J.; Blackler, I.M.C.; Blaskiewicz, M.; Brown, K.A.; Brennan, M.; Bruno, D.; Butler, J.; Carlson, C.; Connolly, R.; D'Ottavio, T.; Fischer, W.; Fu, W.; Gassner, D.; Harvey, M.; Hayes, T.; Huang, H.; Hulsart, R.; Ingrassia, P.; Kling, N.; Lafky, M.; Laster, J.; Lee, R.C.; Litvinenko, V.; Luo, Y.; MacKay, W.W.; Marr, G.; Mapes. M.; Marusic, A.; Mernick, K.; Michnoff, R.; Minty, M.; Montag, C.; Morris, J.; Naylor, C.; Nemesure, S.; Pilat, F.; Ptitsyn, V.; Robert-Demolaize, G.; Roser, T.; Sampson, P.; Satogata, T.; Schoefer, V.; Schultheiss, C.; Severino, F.; Shrey, T.; Smith, K.S.; Tepikian, S.; Thieberger, P.; Trbojevic, D.; Tsoupas, N.; Tuozzolo, J.; van Kuik, B.; Wilinski, M.; Zaltsman, A.; Zeno, K.; Zhang, S.Y.

    2011-03-28

    As part of the search for a phase transition or critical point on the QCD phase diagram, an energy scan including 5 different energy settings was performed during the 2010 RHIC heavy ion run. While the top beam energy for heavy ions is at 100 GeV/n and the lowest achieved energy setpoint was significantly below RHICs injection energy of approximately 10 GeV/n, we also provided beams for data taking in a medium energy range above injection energy and below top beam energy. This paper reviews RHIC experience and challenges for RHIC medium energy operations that produced full experimental data sets at beam energies of 31.2 GeV/n and 19.5 GeV/n. The medium energy AuAu run covered two beam energies, both above the RHIC injection energy of 9.8 GeV but well below the standard store energy of 100 GeV (see table 1). The low energy and full energy runs with heavy ions in FY10 are summarized in [1] and [2]. Stochastic Cooling ([3]) was only used for 100 GeV beams and not used in the medium energy run. The efficiency of the transition from 100 GeV operation to 31.2 GeV and then to 19.5 GeV was remarkable. Setup took 32 h and 19 h respectively for the two energy settings. The time in store, defined to be the percentage of time RHIC provides beams in physics conditions versus calendar time, was approximately 52% for the entire FY10 heavy ion run. In both medium energy runs it was well above this average, 68% for 31.5 GeV and 82% for 19.5 GeV. For both energies RHIC was filled with 111 bunches with 1.2 10{sup 9} and 1.3 10{sup 9} ions per bunch respectively.

  8. Energy Production Demonstrator for Megawatt Proton Beams

    SciTech Connect

    Pronskikh, Vitaly S.; Mokhov, Nikolai V.; Novitski, Igor; Tyutyunnikov, Sergey I.

    2014-07-16

    A preliminary study of the Energy Production Demonstrator (EPD) concept - a solid heavy metal target irradiated by GeV-range intense proton beams and producing more energy than consuming - is carried out. Neutron production, fission, energy deposition, energy gain, testing volume and helium production are simulated with the MARS15 code for tungsten, thorium, and natural uranium targets in the proton energy range 0.5 to 120 GeV. This study shows that the proton energy range of 2 to 4 GeV is optimal for both a natU EPD and the tungsten-based testing station that would be the most suitable for proton accelerator facilities. Conservative estimates, not including breeding and fission of plutonium, based on the simulations suggest that the proton beam current of 1 mA will be sufficient to produce 1 GW of thermal output power with the natU EPD while supplying < 8% of that power to operate the accelerator. The thermal analysis shows that the concept considered has a problem due to a possible core meltdown; however, a number of approaches (a beam rastering, in first place) are suggested to mitigate the issue. The efficiency of the considered EPD as a Materials Test Station (MTS) is also evaluated in this study.

  9. Hydrogen as an energy medium

    NASA Technical Reports Server (NTRS)

    Cox, K. E.

    1976-01-01

    Coal, though abundant in certain geographical locations of the USA poses environmental problems associated with its mining and combustion. Also, nuclear fission energy appears to have problems regarding safety and radioactive waste disposal that are as yet unresolved. The paper discusses hydrogen use and market projection along with energy sources for hydrogen production. Particular attention is given to hydrogen production technology as related to electrolysis and thermochemical water decomposition. Economics of hydrogen will ultimately be determined by the price and availability of future energy carriers such as electricity and synthetic natural gas. Thermochemical methods of hydrogen production appear to offer promise largely in the efficiency of energy conversion and in capital costs over electrolytic methods.

  10. Energies of backstreaming protons in the foreshock

    NASA Technical Reports Server (NTRS)

    Greenstadt, E. W.

    1976-01-01

    A predicted pattern of energy vs detector location in the cislunar region is displayed for protons of zero pitch angle traveling upstream away from the quasi-parallel bow shock. The pattern is implied by upstream wave boundary properties. In the solar ecliptic, protons are estimated to have a minimum of 1.1 times the solar wind bulk energy E sub SW when the wave boundary is in the early morning sector and a maximum of 8.2 E sub SW when the boundary is near the predawn flank.

  11. An intercomparison of medium energy cross-section codes

    SciTech Connect

    Pearlstein, S.

    1988-05-01

    Five medium energy proton reaction cases are selected for benchmarking nuclear model codes. The quantities calculated are isotopic activation yields for 180 MeV protons on Al and 40-200 MeV protons on Co, and double differential neutron emission spectra from Al, Zr-90 and Pb-208 for 35, 80, 160, 318, and 800 presented consist of three types: a closed form preequilibrium plus evaporation model, an intranuclear-cascade and evaporation model, and a model relying on nuclear systematics. The characteristics of each code are described. There are orders of magnitude differences in the time for each type of code to calculate neutron emission spectra, with codes using systematics, preequilibrium and intranuclear-cascade models requiring seconds, minutes and hours, respectively. Calculations are not compared with experiment in this initial study. For double differential neutron emission spectra, there is good overall agreement in magnitude among the different types of codes at forward angles. Differences where they occur at forward angles are greatest for the mid-energy neutrons emitted. At back angles the incident energy at which the best overall agreement is obtained is 160 MeV and the material for which the best overall agreement is obtained is Al. 4 refs., 7 tabs.

  12. Medium energy nuclear physics research

    SciTech Connect

    Peterson, G.A.; Dubach, J.F.; Hicks, R.S.; Miskimen, R.A.

    1992-06-01

    This paper covers the following topics: Experiment 87-02: Threshold Electrodisintegration of the Deuteron at High Q{sup 2}; Measurement of the 5th Structure Function in Deuterium and {sup 12}C; Single-Particle Densities of sd-Shell Nuclei; Experiment 84-28: Transverse Form Factors of {sup 117}Sn; Experiment 82-11: Elastic Magnetic Electron Scattering from {sup 13}C; Experiment 89-09: Measurement of the Elastic Magnetic Form Factor of {sup 3}He at High Momentum Transfer; Experiment 89-15: Coincidence Measurement of the D(e,e{prime}p) Cross-Section at Low Excitation Energy and High Momentum Transfer; Experiment 87-09: Measurement of the Quadrupole Contribution to the N {yields} {Delta} Excitation; Experiment E-140: Measurement of the x-, Q{sup 2} and A-Dependence of R = {sigma}{sub L}/{sigma}{sub T}; PEP Beam-Gas Event Analysis: Physics with the SLAC TPC/2{gamma} Detector; Drift Chamber Tests at Brookhaven National Laboratory; Experiment PR-89-031: Multi-nucleon Knockout Using the CLAS Detector; Electronics Design for the CLAS Region 1 Drift Chamber; Color Transparencies in the Electroproduction of Nucleon Resonances; and Experiment PR-89-015: Study of Coincidence Reactions in the Dip and Delta-Resonance Regions.

  13. Calibration of a proton beam energy monitor

    SciTech Connect

    Moyers, M. F.; Coutrakon, G. B.; Ghebremedhin, A.; Shahnazi, K.; Koss, P.; Sanders, E.

    2007-06-15

    Delivery of therapeutic proton beams requires an absolute energy accuracy of {+-}0.64 to 0.27 MeV for patch fields and a relative energy accuracy of {+-}0.10 to 0.25 MeV for tailoring the depth dose distribution using the energy stacking technique. Achromatic switchyard tunes, which lead to better stability of the beam incident onto the patient, unfortunately limit the ability of switchyard magnet tesla meters to verify the correct beam energy within the tolerances listed above. A new monitor to measure the proton energy before each pulse is transported through the switchyard has been installed into a proton synchrotron. The purpose of this monitor is to correct and/or inhibit beam delivery when the measured beam energy is outside of the tolerances for treatment. The monitor calculates the beam energy using data from two frequency and eight beam position monitors that measure the revolution frequency of the proton bunches and the effective offset of the orbit from the nominal radius of the synchrotron. The new energy monitor has been calibrated by measuring the range of the beam through water and comparing with published range-energy tables for various energies. A relationship between depth dose curves and range-energy tables was first determined using Monte Carlo simulations of particle transport and energy deposition. To reduce the uncertainties associated with typical scanning water phantoms, a new technique was devised in which the beam energy was scanned while fixed thickness water tanks were sandwiched between two fixed parallel plate ionization chambers. Using a multitude of tank sizes, several energies were tested to determine the nominal accelerator orbit radius. After calibration, the energy reported by the control system matched the energy derived by range measurements to better than 0.72 MeV for all nine energies tested between 40 and 255 MeV with an average difference of -0.33 MeV. A study of different combinations of revolution frequency and radial

  14. Spencer-Attix water/medium stopping-power ratios for the dosimetry of proton pencil beams

    NASA Astrophysics Data System (ADS)

    Gomà, C.; Andreo, P.; Sempau, J.

    2013-04-01

    This paper uses Monte Carlo simulations to calculate the Spencer-Attix water/medium stopping-power ratios (sw, med) for the dosimetry of scanned proton pencil beams. It includes proton energies from 30 to 350 MeV and typical detection materials such as air (ionization chambers), radiochromic film, gadolinium oxysulfide (scintillating screens), silicon and lithium fluoride. Track-ends and particles heavier than protons were found to have a negligible effect on the water/air stopping-power ratios (sw, air), whereas the mean excitation energy values were found to carry the largest source of uncertainty. The initial energy spread of the beam was found to have a minor influence on the sw, air values in depth. The water/medium stopping-power ratios as a function of depth in water were found to be quite constant for air and radiochromic film—within 2.5%. Also, the sw, med values were found to have no clinically relevant dependence on the radial distance—except for the case of gadolinium oxysulfide and proton radiography beams. In conclusion, the most suitable detection materials for depth-dose measurements in water were found to be air and radiochromic film active layer, although a small correction is still needed to compensate for the different sw, med values between the plateau and the Bragg peak region. Also, all the detection materials studied in this work—except for gadolinium oxysulfide—were found to be suitable for lateral dose profiles and field-specific dose distribution measurements in water.

  15. Spencer-Attix water/medium stopping-power ratios for the dosimetry of proton pencil beams.

    PubMed

    Gomà, C; Andreo, P; Sempau, J

    2013-04-21

    This paper uses Monte Carlo simulations to calculate the Spencer-Attix water/medium stopping-power ratios (sw, med) for the dosimetry of scanned proton pencil beams. It includes proton energies from 30 to 350 MeV and typical detection materials such as air (ionization chambers), radiochromic film, gadolinium oxysulfide (scintillating screens), silicon and lithium fluoride. Track-ends and particles heavier than protons were found to have a negligible effect on the water/air stopping-power ratios (sw, air), whereas the mean excitation energy values were found to carry the largest source of uncertainty. The initial energy spread of the beam was found to have a minor influence on the sw, air values in depth. The water/medium stopping-power ratios as a function of depth in water were found to be quite constant for air and radiochromic film-within 2.5%. Also, the sw, med values were found to have no clinically relevant dependence on the radial distance-except for the case of gadolinium oxysulfide and proton radiography beams. In conclusion, the most suitable detection materials for depth-dose measurements in water were found to be air and radiochromic film active layer, although a small correction is still needed to compensate for the different sw, med values between the plateau and the Bragg peak region. Also, all the detection materials studied in this work-except for gadolinium oxysulfide-were found to be suitable for lateral dose profiles and field-specific dose distribution measurements in water.

  16. Proton-Nucleus Elastic Cross Sections Using Two-Body In-Medium Scattering Amplitudes

    NASA Technical Reports Server (NTRS)

    Tripathi, R. K.; Wilson, John W.; Cucinotta, Francis A.

    2001-01-01

    Recently, a method was developed of extracting nucleon-nucleon (NN) cross sections in the medium directly from experiment. The in-medium NN cross sections form the basic ingredients of several heavy-ion scattering approaches including the coupled-channel approach developed at the Langley Research Center. The ratio of the real to the imaginary part of the two-body scattering amplitude in the medium was investigated. These ratios are used in combination with the in-medium NN cross sections to calculate elastic proton-nucleus cross sections. The agreement is excellent with the available experimental data. These cross sections are needed for the radiation risk assessment of space missions.

  17. Energy spectrum control for modulated proton beams

    SciTech Connect

    Hsi, Wen C.; Moyers, Michael F.; Nichiporov, Dmitri; Anferov, Vladimir; Wolanski, Mark; Allgower, Chris E.; Farr, Jonathan B.; Mascia, Anthony E.; Schreuder, Andries N.

    2009-06-15

    In proton therapy delivered with range modulated beams, the energy spectrum of protons entering the delivery nozzle can affect the dose uniformity within the target region and the dose gradient around its periphery. For a cyclotron with a fixed extraction energy, a rangeshifter is used to change the energy but this produces increasing energy spreads for decreasing energies. This study investigated the magnitude of the effects of different energy spreads on dose uniformity and distal edge dose gradient and determined the limits for controlling the incident spectrum. A multilayer Faraday cup (MLFC) was calibrated against depth dose curves measured in water for nonmodulated beams with various incident spectra. Depth dose curves were measured in a water phantom and in a multilayer ionization chamber detector for modulated beams using different incident energy spreads. Some nozzle entrance energy spectra can produce unacceptable dose nonuniformities of up to {+-}21% over the modulated region. For modulated beams and small beam ranges, the width of the distal penumbra can vary by a factor of 2.5. When the energy spread was controlled within the defined limits, the dose nonuniformity was less than {+-}3%. To facilitate understanding of the results, the data were compared to the measured and Monte Carlo calculated data from a variable extraction energy synchrotron which has a narrow spectrum for all energies. Dose uniformity is only maintained within prescription limits when the energy spread is controlled. At low energies, a large spread can be beneficial for extending the energy range at which a single range modulator device can be used. An MLFC can be used as part of a feedback to provide specified energy spreads for different energies.

  18. Small Business Innovation Research Award Success Story: Proton Energy Systems

    SciTech Connect

    2011-04-01

    This success story describes Proton Energy Systems, a small business that designs and manufactures proton exchange membrane (PEM) electrolysis sytems to produce hydrogen from water. The U.S. Department of Energy's Fuel Cell Technologies Program has supported much of Proton's technology development through Small Business Innovation Research (SBIR) Awards and other non-SBIR funding.

  19. Proton energy optimization and reduction for intensity-modulated proton therapy

    PubMed Central

    Cao, Wenhua; Lim, Gino; Liao, Li; Li, Yupeng; Jiang, Shengpeng; Li, Xiaoqiang; Li, Heng; Suzuki, Kazumichi; Zhu, X. Ronald; Gomez, Daniel; Zhang, Xiaodong

    2015-01-01

    Intensity-modulated proton therapy (IMPT) is commonly delivered via the spot-scanning technique. To “scan” the target volume, the proton beam is controlled by varying its energy to penetrate the patient’s body at different depths. Although scanning the proton beamlets or spots with the same energy can be as fast as 10–20 m/s, changing from one proton energy to another requires approximately two additional seconds. The total IMPT delivery time thus depends mainly on the number of proton energies used in a treatment. Current treatment planning systems typically use all proton energies that are required for the proton beam to penetrate in a range from the distal edge to the proximal edge of the target. The optimal selection of proton energies has not been well studied. In this study, we sought to determine the feasibility of optimizing and reducing the number of proton energies in IMPT planning. We proposed an iterative mixed-integer programming optimization method to select a subset of all available proton energies while satisfying dosimetric criteria. We applied our proposed method to six patient datasets: four cases of prostate cancer, one case of lung cancer, and one case of mesothelioma. The numbers of energies were reduced by 14.3%–18.9% for the prostate cancer cases, 11.0% for the lung cancer cases, and 26.5% for the mesothelioma case. The results indicate that the number of proton energies used in conventionally designed IMPT plans can be reduced without degrading dosimetric performance. The IMPT delivery efficiency could be improved by energy layer optimization leading to increased throughput for a busy proton center in which a delivery system with slow energy switch is employed. PMID:25295881

  20. Evaluation at the medium energy region for Pb-208 and Bi-209

    SciTech Connect

    Fukahori, Tokio; Pearlstein, S.

    1991-01-01

    Medium energy nuclear data in the 1--1000 MeV range is necessary to accelerator applications which include spallation neutron sources for radioactive waste treatment and accelerator shielding design, medical applications which include isotopes production and radiation therapy, and space applications. For the design of fission and fusion reactors, the nuclear data file for neutrons below 20 MeV is available and well evaluated. Evaluated nuclear data for protons and data in the medium energy region, however, have not been prepared completely. Evaluation in the medium energy region was performed using the theoretical calculation code ALICE-P or experimental data. In this paper, the evaluation of neutron and proton induced nuclear data for Pb-208 and Bi-209 has been performed using ALICE-P, empirical calculations and new systematics for the fission cross section. The evaluated data are compiled for possible inclusion in the ENDF/B-VI High Energy File. 204 refs., 51 figs., 9 tabs.

  1. Single-energy intensity modulated proton therapy

    NASA Astrophysics Data System (ADS)

    Farace, Paolo; Righetto, Roberto; Cianchetti, Marco

    2015-09-01

    In this note, an intensity modulated proton therapy (IMPT) technique, based on the use of high single-energy (SE-IMPT) pencil beams, is described. The method uses only the highest system energy (226 MeV) and only lateral penumbra to produce dose gradient, as in photon therapy. In the study, after a preliminary analysis of the width of proton pencil beam penumbras at different depths, SE-IMPT was compared with conventional IMPT in a phantom containing titanium inserts and in a patient, affected by a spinal chordoma with fixation rods. It was shown that SE-IMPT has the potential to produce a sharp dose gradient and that it is not affected by the uncertainties produced by metal implants crossed by the proton beams. Moreover, in the chordoma patient, target coverage and organ at risk sparing of the SE-IMPT plan resulted comparable to that of the less reliable conventional IMPT technique. Robustness analysis confirmed that SE-IMPT was not affected by range errors, which can drastically affect the IMPT plan. When accepting a low-dose spread as in modern photon techniques, SE-IMPT could be an option for the treatment of lesions (e.g. cervical bone tumours) where steep dose gradient could improve curability, and where range uncertainty, due for example to the presence of metal implants, hampers conventional IMPT.

  2. Single-energy intensity modulated proton therapy.

    PubMed

    Farace, Paolo; Righetto, Roberto; Cianchetti, Marco

    2015-10-01

    In this note, an intensity modulated proton therapy (IMPT) technique, based on the use of high single-energy (SE-IMPT) pencil beams, is described.The method uses only the highest system energy (226 MeV) and only lateral penumbra to produce dose gradient, as in photon therapy. In the study, after a preliminary analysis of the width of proton pencil beam penumbras at different depths, SE-IMPT was compared with conventional IMPT in a phantom containing titanium inserts and in a patient, affected by a spinal chordoma with fixation rods.It was shown that SE-IMPT has the potential to produce a sharp dose gradient and that it is not affected by the uncertainties produced by metal implants crossed by the proton beams. Moreover, in the chordoma patient, target coverage and organ at risk sparing of the SE-IMPT plan resulted comparable to that of the less reliable conventional IMPT technique. Robustness analysis confirmed that SE-IMPT was not affected by range errors, which can drastically affect the IMPT plan.When accepting a low-dose spread as in modern photon techniques, SE-IMPT could be an option for the treatment of lesions (e.g. cervical bone tumours) where steep dose gradient could improve curability, and where range uncertainty, due for example to the presence of metal implants, hampers conventional IMPT. PMID:26352616

  3. Systematics of proton and diproton separation energies for light nuclei

    SciTech Connect

    Cole, B.J.

    1997-10-01

    A simple method to estimate proton and two-proton separation energies of proton-rich nuclei is presented that is sufficiently accurate to allow the prediction of suitable candidates for observable diproton decay. The method is based on the systematics of measured particle separation energies. Predictions for proton-rich nuclei with Z=18{minus}24 are compared with the results of previous calculations. {copyright} {ital 1997} {ital The American Physical Society}

  4. Detailed parametrization of neutrino and gamma-ray energy spectra from high energy proton-proton interactions

    NASA Astrophysics Data System (ADS)

    Supanitsky, A. D.

    2016-02-01

    Gamma rays and neutrinos are produced as a result of proton-proton interactions that occur in different astrophysical contexts. The detection of these two types of messengers is of great importance for the study of different physical phenomena, related to nonthermal processes, taking place in different astrophysical scenarios. Therefore, the knowledge of the energy spectrum of these two types of particles, as a function of the incident proton energy, is essential for the interpretation of the observational data. In this paper, parametrizations of the energy spectra of gamma rays and neutrinos, originated in proton-proton collisions, are presented. The energy range of the incident protons considered extends from 102 to 108 GeV . The parametrizations are based on Monte Carlo simulations of proton-proton interactions performed with the hadronic interaction models QGSJET-II-04 and EPOS-LHC, which have recently been updated with the data taken by the Large Hadron Collider.

  5. Cryogenic helium as stopping medium for high-energy ions

    NASA Astrophysics Data System (ADS)

    Purushothaman, S.; Dendooven, P.; Moore, I.; Penttilä, H.; Ronkainen, J.; Saastamoinen, A.; Äystö, J.; Peräjärvi, K.; Takahashi, N.; Gloos, K.

    2008-10-01

    We have investigated the survival and transport efficiency of 219Rn ions emitted by a 223Ra source in high-density cryogenic helium gas, with ionisation of the gas induced by a proton beam. The combined efficiency of ion survival and transport by an applied electric field was measured as a function of ionisation rate density for electric fields up to 160 V/cm and for three temperature and density combinations: 77 K, 0.18 mg/cm3, 10 K, 0.18 mg/cm3 and 10 K, 0.54 mg/cm3. At low beam intensity or high electric field, an efficiency of 30 % is obtained, confirming earlier results. A sharp drop in efficiency is observed at a "threshold" ionisation rate density which increases with the square of the applied electric field. At 160 V/cm, the efficiency stays above 10% up to an ionisation rate density of 1012 ion-electron pairs/cm3/s. The observed behaviour is understood as the result of shielding of the applied field by the weak plasma created by the proton beam: it counteracts the effective transport of ions and electrons, leading to recombination between the two. We conclude that cryogenic helium gas at high-density and high electric field is a promising medium for the transformation of very high-energy ions into low-energy ones.

  6. PRaVDA: High Energy Physics towards proton Computed Tomography

    NASA Astrophysics Data System (ADS)

    Price, T.

    2016-07-01

    Proton radiotherapy is an increasingly popular modality for treating cancers of the head and neck, and in paediatrics. To maximise the potential of proton radiotherapy it is essential to know the distribution, and more importantly the proton stopping powers, of the body tissues between the proton beam and the tumour. A stopping power map could be measured directly, and uncertainties in the treatment vastly reduce, if the patient was imaged with protons instead of conventional x-rays. Here we outline the application of technologies developed for High Energy Physics to provide clinical-quality proton Computed Tomography, in so reducing range uncertainties and enhancing the treatment of cancer.

  7. Nuclear structure studies with medium energy probes. [Northwestern Univ

    SciTech Connect

    Seth, Kamal K.

    1980-01-01

    Progress in the continuing program of experimental research in nuclear structure with medium-energy probes during the year 1979-1980 is reviewed, and the research activities planned for the year 1980-1981 are discussed. In the study of pion-induced reactions emphasis is placed on investigation of isovector characteristics of nuclear excitations and on double charge exchange reactions. Pion production studies form the major part of the program of experiments with proton beams of 400 to 800 MeV at LAMPF. Current emphasis is on the bearing of these investigations on di-baryon existence. The study of high-spin states and magnetic scattering constitute the main goals of the electron scattering program at Bates. Representative results are presented; completed work is reported in the usual publications. (RWR)

  8. Short- and Medium-term Atmospheric Effects of Very Large Solar Proton Events

    NASA Technical Reports Server (NTRS)

    Jackman, Charles H.; Marsh, Daniel R.; Vitt, Francis M.; Garcia, Rolando R.; Fleming, Eric L.; Labow, Gordon J.; Randall, Cora E.; Lopez-Puertas, Manuel; Funke, Bernd

    2007-01-01

    Long-term variations in ozone have been caused by both natural and humankind related processes. In particular, the humankind or anthropogenic influence on ozone from chlorofluorocarbons and halons (chlorine and bromine) has led to international regulations greatly limiting the release of these substances. These anthropogenic effects on ozone are most important in polar regions and have been significant since the 1970s. Certain natural ozone influences are also important in polar regions and are caused by the impact of solar charged particles on the atmosphere. Such natural variations have been studied in order to better quantify the human influence on polar ozone. Large-scale explosions on the Sun near solar maximum lead to emissions of charged particles (mainly protons and electrons), some of which enter the Earth's magnetosphere and rain down on the polar regions. "Solar proton events" have been used to describe these phenomena since the protons associated with these solar events sometimes create a significant atmospheric disturbance. We have used the National Center for Atmospheric Research (NCAR) Whole Atmosphere Community Climate Model (WACCM) to study the short- and medium-term (days to a few months) influences of solar proton events between 1963 and 2005 on stratospheric ozone. The four largest events in the past 45 years (August 1972; October 1989; July 2000; and October-November 2003) caused very distinctive polar changes in layers of the Earth's atmosphere known as the stratosphere (12-50 km; -7-30 miles) and mesosphere (50-90 km; 30-55 miles). The solar protons connected with these events created hydrogen- and nitrogen- containing compounds, which led to the polar ozone destruction. The hydrogen-containing compounds have very short lifetimes and lasted for only a few days (typically the duration of the solar proton event). On the other hand, the nitrogen-containing compounds lasted much longer, especially in the Winter. The nitrogen oxides were predicted

  9. Neutron-Proton Pairing Effect on One-Proton and Two-Proton Separation Energies in Rare-Earth Proton-Rich Nuclei

    NASA Astrophysics Data System (ADS)

    Hammache, F.; Allal, N. H.; Fellah, M.

    2012-12-01

    The one-proton and two-proton separation energies are studied for "ordinary" and rare-earth proton-rich nuclei by including the isovector neutron-proton (np) pairing correlations using the BCS approximation. Even-even as well as odd nuclei are considered. In the latter case, the wave function is defined using the blocked-level technique. The single-particle energies used are those of a deformed Woods-Saxon mean field. It is shown that the np isovector pairing effects on the one-proton and two-proton separation energies are non-negligible. However, the only isovector BCS approximation seems to be inadequate for a good description of these quantities when including the np pairing effects: either a particle-number projection or the inclusion of the isoscalar pairing effect seems to be necessary. Another possible improvement would be a more realistic choice of the pairing strengths.

  10. Simulation of proton-induced energy deposition in integrated circuits

    NASA Technical Reports Server (NTRS)

    Fernald, Kenneth W.; Kerns, Sherra E.

    1988-01-01

    A time-efficient simulation technique was developed for modeling the energy deposition by incident protons in modern integrated circuits. To avoid the excessive computer time required by many proton-effects simulators, a stochastic method was chosen to model the various physical effects responsible for energy deposition by incident protons. Using probability density functions to describe the nuclear reactions responsible for most proton-induced memory upsets, the simulator determines the probability of a proton hit depositing the energy necessary for circuit destabilization. This factor is combined with various circuit parameters to determine the expected error-rate in a given proton environment. An analysis of transient or dose-rate effects is also performed. A comparison to experimental energy-disposition data proves the simulator to be quite accurate for predicting the expected number of events in certain integrated circuits.

  11. First experimental research in low energy proton radiography

    NASA Astrophysics Data System (ADS)

    Wei, Tao; Yang, Guo-Jun; Li, Yi-Ding; Long, Ji-Dong; He, Xiao-Zhong; Zhang, Xiao-Ding; Jiang, Xiao-Guo; Ma, Chao-Fan; Zhao, Liang-Chao; Yang, Xing-Lin; Zhang, Zhuo; Wang, Yuan; Pang, Jian; Li, Hong; Li, Wei-Feng; Zhou, Fu-Xin; Shi, Jin-Shui; Zhang, Kai-Zhi; Li, Jin; Zhang, Lin-Wen; Deng, Jian-Jun

    2014-08-01

    Proton radiography is a new scatheless diagnostic tool providing a potential development direction for advanced hydrotesting. Recently a low energy proton radiography system has been developed at the Chinese Academy of Engineering Phyiscs (CAEP). This system has been designed to use an 11 MeV proton beam to radiograph thin static objects. This system consists of a proton cyclotron coupled to an imaging beamline, which is the first domestic beamline dedicated to proton radiography experiments. Via some demonstration experiments, the radiography system is confirmed to provide clear pictures with spatial resolution ~100 μm within 40 mm field-of-view.

  12. Proton-Coupled Electron Transfer Reactions with Photometric Bases Reveal Free Energy Relationships for Proton Transfer.

    PubMed

    Eisenhart, Thomas T; Howland, William C; Dempsey, Jillian L

    2016-08-18

    The proton-coupled electron transfer (PCET) oxidation of p-aminophenol in acetonitrile was initiated via stopped-flow rapid-mixing and spectroscopically monitored. For oxidation by ferrocenium in the presence of 7-(dimethylamino)quinoline proton acceptors, both the electron transfer and proton transfer components could be optically monitored in the visible region; the decay of the ferrocenium absorbance is readily monitored (λmax = 620 nm), and the absorbance of the 2,4-substituted 7-(dimethylamino)quinoline derivatives (λmax = 370-392 nm) red-shifts substantially (ca. 70 nm) upon protonation. Spectral analysis revealed the reaction proceeds via a stepwise electron transfer-proton transfer process, and modeling of the kinetics traces monitoring the ferrocenium and quinolinium signals provided rate constants for elementary proton and electron transfer steps. As the pKa values of the conjugate acids of the 2,4-R-7-(dimethylamino)quinoline derivatives employed were readily tuned by varying the substituents at the 2- and 4-positions of the quinoline backbone, the driving force for proton transfer was systematically varied. Proton transfer rate constants (kPT,2 = (1.5-7.5) × 10(8) M(-1) s(-1), kPT,4 = (0.55-3.0) × 10(7) M(-1) s(-1)) were found to correlate with the pKa of the conjugate acid of the proton acceptor, in agreement with anticipated free energy relationships for proton transfer processes in PCET reactions. PMID:27500804

  13. Proton-Coupled Electron Transfer Reactions with Photometric Bases Reveal Free Energy Relationships for Proton Transfer.

    PubMed

    Eisenhart, Thomas T; Howland, William C; Dempsey, Jillian L

    2016-08-18

    The proton-coupled electron transfer (PCET) oxidation of p-aminophenol in acetonitrile was initiated via stopped-flow rapid-mixing and spectroscopically monitored. For oxidation by ferrocenium in the presence of 7-(dimethylamino)quinoline proton acceptors, both the electron transfer and proton transfer components could be optically monitored in the visible region; the decay of the ferrocenium absorbance is readily monitored (λmax = 620 nm), and the absorbance of the 2,4-substituted 7-(dimethylamino)quinoline derivatives (λmax = 370-392 nm) red-shifts substantially (ca. 70 nm) upon protonation. Spectral analysis revealed the reaction proceeds via a stepwise electron transfer-proton transfer process, and modeling of the kinetics traces monitoring the ferrocenium and quinolinium signals provided rate constants for elementary proton and electron transfer steps. As the pKa values of the conjugate acids of the 2,4-R-7-(dimethylamino)quinoline derivatives employed were readily tuned by varying the substituents at the 2- and 4-positions of the quinoline backbone, the driving force for proton transfer was systematically varied. Proton transfer rate constants (kPT,2 = (1.5-7.5) × 10(8) M(-1) s(-1), kPT,4 = (0.55-3.0) × 10(7) M(-1) s(-1)) were found to correlate with the pKa of the conjugate acid of the proton acceptor, in agreement with anticipated free energy relationships for proton transfer processes in PCET reactions.

  14. 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.

  15. The ISEE 1 and 2 Medium Energy Particles Experiment

    NASA Technical Reports Server (NTRS)

    Williams, D. J.; Fritz, T. A.; Keppler, E.; Wilken, B.; Wibberenz, G.

    1978-01-01

    The Medium Energy Particles Experiment (MEPE) on board ISEE 1 and 2 consists of the WIM instrument on ISEE 1 and the KED instrument on ISEE 2. Both instruments employ solid-state detectors and magnetic analysis to measure the angular, energy, and intensity distributions of protons (ions) above 24 keV and electrons above 20 keV. The WIM instrument also includes a composition measurement employing Delta E-by-E and time-of-flight techniques. Three-parameter analysis is performed above 250 keV/nucleon, and single parameter analysis is performed above 125 keV/nucleon for helium through oxygen. Three-dimensional angular distributions are obtained through the use of a scan platform in the WIM instrument and multiple detector heads in the KED instrument. A variety of operational modes are used to optimize data collection from both instruments. Resolutions up to 128 channels in energy, 192 samples over the unit sphere in angle, and 0.095 sec in time are available.

  16. A detection system for very low-energy protons from {beta}-delayed proton decay

    SciTech Connect

    Spiridon, A.; Pollacco, E.; Trache, L.; Simmons, E.; McCleskey, M.; Roeder, B. T.; Tribble, R. E.; Pascovici, G.; Riallot, M.; Mols, J. P.; Kebbiri, M.

    2012-11-20

    We have recently developed a gas based detection system called AstroBox, motivated by nuclear astrophysics studies. The goal was to detect very low-energy protons from {beta}-delayed p-decay with reduced beta background and improved energy resolution. The detector was tested using the {beta}-delayed proton-emitter 23Al previously studied with a set-up based on thin double-sided Si strip detectors. The proton spectrum obtained with AstroBox showed no beta background down to {approx}80 keV. The low energy (206 keV, 267 keV) proton peaks were positively identified, well separated, and the resolution was improved.

  17. Effects of in-medium nucleon-nucleon cross sections on stopping observable and ratio of free protons in heavy-ion collisions at 400 MeV/nucleon

    NASA Astrophysics Data System (ADS)

    Su, Jun; Huang, Ching-Yuan; Xie, Wen-Jie; Zhang, Feng-Shou

    2016-07-01

    The effects of in-medium nucleon-nucleon cross sections on the stopping observable and ratio of free protons in heavy-ion collisions at 400MeV/nucleon have been investigated within the framework of the IQMD+GEMINI model. Five kinds of in-medium corrections of nucleon-nucleon cross sections, which are considerably different in the referred energy and density, have been used in the model. It has been found that calculations of the stopping decrease when the in-medium cross sections decrease. Moreover, the ratio of free protons Rp depends not only on the value of the in-medium factors but also on its isospin dependence. In order to investigate the isospin effect of in-medium factors on the ratio of free protons Rp, the isospin dependence of in-medium factors has been adjusted and used in the model. The calculations have shown that the isospin dependence of in-medium factors does not impact the stopping, but impacts the ratio of free protons Rp. When the in-medium factors relation f nn med > f pp med is used in the model, the calculated values of Rp are larger than those in the f nn med < f pp med case.

  18. TH-A-19A-01: An Open Source Software for Proton Treatment Planning in Heterogeneous Medium

    SciTech Connect

    Desplanques, M; Baroni, G; Wang, K; Phillips, J; Gueorguiev, G; Sharp, G

    2014-06-15

    Purpose: Due to its success in Radiation Oncology during the last decade, interest in proton therapy is on the rise. Unfortunately, despite the global enthusiasm in the field, there is presently no free, multiplatform and customizable Treatment Planning System (TPS) providing proton dose distributions in heterogenous medium. This restricts substantially the progress of clinical research for groups without access to a commercial Proton TPS. The latest implementation of our pencil beam dose calculation algorithm for proton beams within the 3D Slicer open-source environment fulfills all the conditions described above. Methods: The core dose calculation algorithm is based on the Hong algorithm (1), which was upgraded with the Kanematsu theory describing the evolution of the lateral scattering of proton beamlets in heterogeneous medium. This algorithm deals with both mono-energetic beams and Spread Out Bragg Peak (SOBP). In order to be user-friendly, we provide a graphical user interface implemented with the Qt libraries, and visualization with the 3D Slicer medical image analysis software. Two different pencil beam algorithms were developed, and the clinical proton beam line at our facility was modeled. Results: The dose distributions provided by our algorithms were compared to dose distributions coming from both commercialized XiO TPS and literature (dose measurements, GEANT4 and MCNPx) and turned out to be in a good agreement, with maximum dose discrepancies of 5% in homogeneous phantoms and 10% in heterogeneous phantoms. The algorithm of SOBP creation from an optimized weigthing of mono-energetic beams results in flat SOBP. Conclusion: We hope that our efforts in implementing this new, open-source proton TPS will help the research groups to have a free access to a useful, reliable proton dose calculation software.(1) L. Hong et al., A pencil beam algorithm for proton dose calculations, Phys. Med. Biol. 41 (1996) 1305–1330. This project is paid for by NCI

  19. MEIC Proton Beam Formation with a Low Energy Linac

    SciTech Connect

    Zhang, Yuhong

    2015-09-01

    The MEIC proton and ion beams are generated, accumulated, accelerated and cooled in a new green-field ion injector complex designed specifically to support its high luminosity goal. This injector consists of sources, a linac and a small booster ring. In this paper we explore feasibility of a short ion linac that injects low-energy protons and ions into the booster ring.

  20. Medium-energy hadron-nucleus scattering in the 1/[ital N] expansion formalism

    SciTech Connect

    Kuyucak, S. ); Morrison, I. )

    1993-08-01

    The algebraic-eikonal approach to the medium-energy hadron-nucleus scattering is generalized to arbitrary interactions and boson types using the 1/[ital N] expansion technique for the interacting boson model. The results are used in a comparative study of proton scattering from deformed nuclei in the [ital sd] and [ital sdg] boson models. The two models give almost identical results for a pure quadrupole interaction but widely differ when a hexadecapole interaction is included.

  1. Revealing proton shape fluctuations with incoherent diffraction at high energy

    NASA Astrophysics Data System (ADS)

    Mäntysaari, Heikki; Schenke, Björn

    2016-08-01

    The differential cross section of exclusive diffractive vector meson production in electron proton collisions carries important information on the geometric structure of the proton. More specifically, the coherent cross section as a function of the transferred transverse momentum is sensitive to the size of the proton, while the incoherent or proton dissociative cross section is sensitive to fluctuations of the gluon distribution in coordinate space. We show that at high energies the experimentally measured coherent and incoherent cross sections for the production of J /Ψ mesons are very well reproduced within the color glass condensate framework when strong geometric fluctuations of the gluon distribution in the proton are included. For ρ meson production, we also find reasonable agreement. We study in detail the dependence of our results on various model parameters, including the average proton shape, analyze the effect of saturation scale and color charge fluctuations and constrain the degree of geometric fluctuations.

  2. GEANT4 simulations for low energy proton computerized tomography.

    PubMed

    Milhoretto, Edney; Schelin, Hugo R; Setti, João A P; Denyak, Valery; Paschuk, Sergei A; Evseev, Ivan G; de Assis, Joaquim T; Yevseyeva, O; Lopes, Ricardo T; Vinagre Filho, Ubirajara M

    2010-01-01

    This work presents the recent results of computer simulations for the low energy proton beam tomographic scanner installed at the cyclotron CV-28 of IEN/CNEN. New computer simulations were performed in order to adjust the parameters of previous simulation within the first experimental results and to understand some specific effects that affected the form of the final proton energy spectra. To do this, the energy and angular spread of the initial proton beam were added, and the virtual phantom geometry was specified more accurately in relation to the real one. As a result, a more realistic view on the measurements was achieved.

  3. Hardness assurance for proton direct ionization-induced SEEs using a high-energy proton beam

    SciTech Connect

    Dodds, Nathaniel Anson; Schwank, James R.; Shaneyfelt, Marty R.; Dodd, Paul E.; Doyle, Barney Lee; Trinczek, M.; Blackmore, E. W.; Rodbell, K. P.; Reed, R. A.; Pellish, J. A.; LaBel, K. A.; Marshall, P. W.; Swanson, Scot E.; Vizkelethy, Gyorgy; Van Deusen, Stuart B.; Sexton, Frederick W.; Martinez, Marino J.; Gordon, M. S.

    2014-11-06

    The low-energy proton energy spectra of all shielded space environments have the same shape. This shape is easily reproduced in the laboratory by degrading a high-energy proton beam, producing a high-fidelity test environment. We use this test environment to dramatically simplify rate prediction for proton direct ionization effects, allowing the work to be done at high-energy proton facilities, on encapsulated parts, without knowledge of the IC design, and with little or no computer simulations required. Proton direct ionization (PDI) is predicted to significantly contribute to the total error rate under the conditions investigated. Scaling effects are discussed using data from 65-nm, 45-nm, and 32-nm SOI SRAMs. These data also show that grazing-angle protons will dominate the PDI-induced error rate due to their higher effective LET, so PDI hardness assurance methods must account for angular effects to be conservative. As a result, we show that this angular dependence can be exploited to quickly assess whether an IC is susceptible to PDI.

  4. Hardness assurance for proton direct ionization-induced SEEs using a high-energy proton beam

    DOE PAGES

    Dodds, Nathaniel Anson; Schwank, James R.; Shaneyfelt, Marty R.; Dodd, Paul E.; Doyle, Barney Lee; Trinczek, M.; Blackmore, E. W.; Rodbell, K. P.; Reed, R. A.; Pellish, J. A.; et al

    2014-11-06

    The low-energy proton energy spectra of all shielded space environments have the same shape. This shape is easily reproduced in the laboratory by degrading a high-energy proton beam, producing a high-fidelity test environment. We use this test environment to dramatically simplify rate prediction for proton direct ionization effects, allowing the work to be done at high-energy proton facilities, on encapsulated parts, without knowledge of the IC design, and with little or no computer simulations required. Proton direct ionization (PDI) is predicted to significantly contribute to the total error rate under the conditions investigated. Scaling effects are discussed using data frommore » 65-nm, 45-nm, and 32-nm SOI SRAMs. These data also show that grazing-angle protons will dominate the PDI-induced error rate due to their higher effective LET, so PDI hardness assurance methods must account for angular effects to be conservative. As a result, we show that this angular dependence can be exploited to quickly assess whether an IC is susceptible to PDI.« less

  5. Fission foil detector calibrations with high energy protons

    NASA Technical Reports Server (NTRS)

    Benton, E. V.; Frank, A. L.

    1995-01-01

    Fission foil detectors (FFD's) are passive devices composed of heavy metal foils in contact with muscovite mica films. The heavy metal nuclei have significant cross sections for fission when irradiated with neutrons and protons. Each isotope is characterized by threshold energies for the fission reactions and particular energy-dependent cross sections. In the FFD's, fission fragments produced by the reactions are emitted from the foils and create latent particle tracks in the adjacent mica films. When the films are processed surface tracks are formed which can be optically counted. The track densities are indications of the fluences and spectra of neutrons and/or protons. In the past, detection efficiencies have been calculated using the low energy neutron calibrated dosimeters and published fission cross sections for neutrons and protons. The problem is that the addition of a large kinetic energy to the (n,nucleus) or (p,nucleus) reaction could increase the energies and ranges of emitted fission fragments and increase the detector sensitivity as compared with lower energy neutron calibrations. High energy calibrations are the only method of resolving the uncertainties in detector efficiencies. At high energies, either proton or neutron calibrations are sufficient since the cross section data show that the proton and neutron fission cross sections are approximately equal. High energy proton beams have been utilized (1.8 and 4.9 GeV, 80 and 140 MeV) for measuring the tracks of fission fragments emitted backward and forward.

  6. Concept of proton radiography using energy resolved dose measurement.

    PubMed

    Bentefour, El H; Schnuerer, Roland; Lu, Hsiao-Ming

    2016-08-21

    Energy resolved dosimetry offers a potential path to single detector based proton imaging using scanned proton beams. This is because energy resolved dose functions encrypt the radiological depth at which the measurements are made. When a set of predetermined proton beams 'proton imaging field' are used to deliver a well determined dose distribution in a specific volume, then, at any given depth x of this volume, the behavior of the dose against the energies of the proton imaging field is unique and characterizes the depth x. This concept applies directly to proton therapy scanning delivery methods (pencil beam scanning and uniform scanning) and it can be extended to the proton therapy passive delivery methods (single and double scattering) if the delivery of the irradiation is time-controlled with a known time-energy relationship. To derive the water equivalent path length (WEPL) from the energy resolved dose measurement, one may proceed in two different ways. A first method is by matching the measured energy resolved dose function to a pre-established calibration database of the behavior of the energy resolved dose in water, measured over the entire range of radiological depths with at least 1 mm spatial resolution. This calibration database can also be made specific to the patient if computed using the patient x-CT data. A second method to determine the WEPL is by using the empirical relationships between the WEPL and the integral dose or the depth at 80% of the proximal fall off of the energy resolved dose functions in water. In this note, we establish the evidence of the fundamental relationship between the energy resolved dose and the WEPL at the depth of the measurement. Then, we illustrate this relationship with experimental data and discuss its imaging dynamic range for 230 MeV protons. PMID:27435446

  7. Concept of proton radiography using energy resolved dose measurement

    NASA Astrophysics Data System (ADS)

    Bentefour, El H.; Schnuerer, Roland; Lu, Hsiao-Ming

    2016-08-01

    Energy resolved dosimetry offers a potential path to single detector based proton imaging using scanned proton beams. This is because energy resolved dose functions encrypt the radiological depth at which the measurements are made. When a set of predetermined proton beams ‘proton imaging field’ are used to deliver a well determined dose distribution in a specific volume, then, at any given depth x of this volume, the behavior of the dose against the energies of the proton imaging field is unique and characterizes the depth x. This concept applies directly to proton therapy scanning delivery methods (pencil beam scanning and uniform scanning) and it can be extended to the proton therapy passive delivery methods (single and double scattering) if the delivery of the irradiation is time-controlled with a known time-energy relationship. To derive the water equivalent path length (WEPL) from the energy resolved dose measurement, one may proceed in two different ways. A first method is by matching the measured energy resolved dose function to a pre-established calibration database of the behavior of the energy resolved dose in water, measured over the entire range of radiological depths with at least 1 mm spatial resolution. This calibration database can also be made specific to the patient if computed using the patient x-CT data. A second method to determine the WEPL is by using the empirical relationships between the WEPL and the integral dose or the depth at 80% of the proximal fall off of the energy resolved dose functions in water. In this note, we establish the evidence of the fundamental relationship between the energy resolved dose and the WEPL at the depth of the measurement. Then, we illustrate this relationship with experimental data and discuss its imaging dynamic range for 230 MeV protons.

  8. Acceleration of low-energy protons and alpha particles at interplanetary shock waves

    NASA Technical Reports Server (NTRS)

    Scholer, M.; Hovestadt, D.; Ipavich, F. M.; Gloeckler, G.

    1983-01-01

    The low-energy protons and alpha particles in the energy range 30 keV/charge to 150 keV/charge associated with three different interplanetary shock waves in the immediate preshock and postshock region are studied using data obtained by the ISEE 3. The spatial distributions in the preshock and postshock medium are presented, and the dependence of the phase space density at different energies on the distance from the shock and on the form of the distribution function of both species immediately at the shock is examined. It is found that in the preshock region the particles are flowing in the solar wind frame of reference away from the shock and in the postshock medium the distribution is more or less isotropic in this frame of reference. The distribution function in the postshock region can be represented by a power law in energy which has the same spectral exponent for both protons and alpha particles. It is concluded that the first-order Fermi acceleration process can consistently explain the data, although the spectra of diffuse bow shock associated particles are different from the spectra of the interplanetary shock-associated particles in the immediate vicinity of the shock. In addition, the mean free path of the low energy ions in the preshock medium is found to be considerably smaller than the mean free path determined by the turbulence of the background interplanetary medium.

  9. Thermal and structural stability of medium energy target carrier assembly for NOvA at Fermilab

    SciTech Connect

    McGee, M.W.; Ader, C.; Anderson, K.; Hylen, J.; Martens, M.; /Fermilab

    2010-05-01

    The NOvA project will upgrade the existing Neutrino at Main Injector (NuMI) project beamline at Fermilab to accommodate beam power of 700 kW. The Medium Energy (ME) graphite target assembly is provided through an accord with the State Research Center of Russia Institute for High Energy Physics (IHEP) at Protvino, Russia. The effects of proton beam energy deposition within beamline components are considered as thermal stability of the target carrier assembly and alignment budget are critical operational issues. Results of finite element thermal and structural analysis involving the target carrier assembly is provided with detail regarding the target's beryllium windows.

  10. High energy protons generation by two sequential laser pulses

    SciTech Connect

    Wang, Xiaofeng; Shen, Baifei E-mail: zhxm@siom.ac.cn; Zhang, Xiaomei E-mail: zhxm@siom.ac.cn; Wang, Wenpeng; Xu, Jiancai; Yi, Longqing; Shi, Yin

    2015-04-15

    The sequential proton acceleration by two laser pulses of relativistic intensity is proposed to produce high energy protons. In the scheme, a relativistic super-Gaussian (SG) laser pulse followed by a Laguerre-Gaussian (LG) pulse irradiates dense plasma attached by underdense plasma. A proton beam is produced from the target and accelerated in the radiation pressure regime by the short SG pulse and then trapped and re-accelerated in a special bubble driven by the LG pulse in the underdense plasma. The advantages of radiation pressure acceleration and LG transverse structure are combined to achieve the effective trapping and acceleration of protons. In a two-dimensional particle-in-cell simulation, protons of 6.7 GeV are obtained from a 2 × 10{sup 22 }W/cm{sup 2} SG laser pulse and a LG pulse at a lower peak intensity.

  11. A fast chopper for medium energy beams

    NASA Astrophysics Data System (ADS)

    Madrak, R.; Wildman, D.

    2014-10-01

    The key elements have been constructed for a fast chopper system capable of removing single 2.5 MeV proton bunches spaced at 325 MHz. The average chopping rate is ~ 1 MHz. The components include a pulse delaying microstrip structure for deflecting the beam, high voltage (1.2 kV) fast (ns rise time) pulsers, and an associated wideband combiner. Various designs for the deflecting structures have been studied. Measurements of the microstrip structures' coverage factors and pulse shapes are presented.

  12. A fast chopper for medium energy beams

    SciTech Connect

    Madrak, R.; Wildman, D.

    2014-10-30

    The key elements have been constructed for a fast chopper system capable of removing single 2.5 MeV proton bunches spaced at 325 MHz. The average chopping rate is ~ 1 MHz. The components include a pulse delaying microstrip structure for deflecting the beam, high voltage (1.2 kV) fast (ns rise time) pulsers, and an associated wideband combiner. Various designs for the deflecting structures have been studied. Measurements of the microstrip structures' coverage factors and pulse shapes are presented.

  13. Very Low Energy Protons From the Beta Decay of Proton Rich Nuclei For Nuclear Astrophysics

    SciTech Connect

    Simmons, E.; Trache, L.; Banu, A.; McCleskey, M.; Roeder, B.; Spiridon, A.; Tribble, R. E.; Saastamoinen, A.; Aysto, J.; Davinson, T.; Woods, P. J.; Lotay, G. J.

    2010-03-01

    We have developed a new experimental technique to measure very low energy protons from beta-delayed p-decay of proton-rich nuclei produced and separated with the MARS recoil spectrometer at TAMU. Recently we have investigated the beta-delayed p-decays of {sup 23}Al and {sup 31}Cl and obtained information on the resonances in the reactions {sup 22}Na(p,gamma){sup 23}Mg and {sup 30}P(p,gamma){sup 31}S, respectively. These reactions are important in explosive H-burning in Novae. A simple setup consisting of a telescope made of a thin double sided Si strip detector (p-detector) backed or sandwiched between two thick Si detectors (beta-detectors) was designed. We studied two different p-detectors and found that the thinner detectors with a small cell size are best to measure proton energies as low as 2-300 keV.

  14. Maximum kinetic energy considerations in proton stereotactic radiosurgery.

    PubMed

    Sengbusch, Evan R; Mackie, Thomas R

    2011-04-12

    The purpose of this study was to determine the maximum proton kinetic energy required to treat a given percentage of patients eligible for stereotactic radiosurgery (SRS) with coplanar arc-based proton therapy, contingent upon the number and location of gantry angles used. Treatment plans from 100 consecutive patients treated with SRS at the University of Wisconsin Carbone Cancer Center between June of 2007 and March of 2010 were analyzed. For each target volume within each patient, in-house software was used to place proton pencil beam spots over the distal surface of the target volume from 51 equally-spaced gantry angles of up to 360°. For each beam spot, the radiological path length from the surface of the patient to the distal boundary of the target was then calculated along a ray from the gantry location to the location of the beam spot. This data was used to generate a maximum proton energy requirement for each patient as a function of the arc length that would be spanned by the gantry angles used in a given treatment. If only a single treatment angle is required, 100% of the patients included in the study could be treated by a proton beam with a maximum kinetic energy of 118 MeV. As the length of the treatment arc is increased to 90°, 180°, 270°, and 360°, the maximum energy requirement increases to 127, 145, 156, and 179 MeV, respectively. A very high percentage of SRS patients could be treated at relatively low proton energies if the gantry angles used in the treatment plan do not span a large treatment arc. Maximum proton kinetic energy requirements increase linearly with size of the treatment arc.

  15. Maximum kinetic energy considerations in proton stereotactic radiosurgery

    PubMed Central

    Sengbusch, Evan R.; Mackie, Thomas R.

    2016-01-01

    The purpose of this study was to determine the maximum proton kinetic energy required to treat a given percentage of patients eligible for stereotactic radiosurgery (SRS) with coplanar arc-based proton therapy, contingent upon the number and location of gantry angles used. Treatment plans from 100 consecutive patients treated with SRS at the University of Wisconsin Carbone Cancer Center between June of 2007 and March of 2010 were analyzed. For each target volume within each patient, in-house software was used to place proton pencil beam spots over the distal surface of the target volume from 51 equally-spaced gantry angles of up to 360°. For each beam spot, the radiological path length from the surface of the patient to the distal boundary of the target was then calculated along a ray from the gantry location to the location of the beam spot. This data was used to generate a maximum proton energy requirement for each patient as a function of the arc length that would be spanned by the gantry angles used in a given treatment. If only a single treatment angle is required, 100% of the patients included in the study could be treated by a proton beam with a maximum kinetic energy of 118 MeV. As the length of the treatment arc is increased to 90°, 180°, 270°, and 360°, the maximum energy requirement increases to 127, 145, 156, and 179 MeV, respectively. A very high percentage of SRS patients could be treated at relatively low proton energies if the gantry angles used in the treatment plan do not span a large treatment arc. Maximum proton kinetic energy requirements increase linearly with size of the treatment arc. PMID:21844866

  16. Magnetic field nonuniformities and NMR of protons diffusing in a porous medium.

    PubMed

    Bergman, D J; Dunn, K J; LaTorraca, G A

    1996-01-01

    Magnetic field inhomogeneity can arise either because of an externally applied field gradient or because of spatial variations in magnetic susceptibility. The latter are most important when the solid matrix includes paramagnetic substances and when the uniform applied field, and, consequently, also the Larmor precession frequency are very large. Both types of field inhomogeneity add extra phase shifts to the precessing spins. These phase shifts vary with time and position in a complex and random fashion as a result of the diffusive motion of the spins. We have studied these effects by performing detailed calculations for the case of a fluid filled porous medium with a periodic microstructure. Special attention was devoted to the question of whether the statistical distribution of the phase shifts encountered in a Hahn spin echo experiment or in a Carr-Purcell-Meiboom-Gill (CPMG) spin-echo train can be approximated as a Gaussian. The mean square phase shift is measured in such experiments as an enhanced relaxation rate of the precessing transverse magnetization. We determine this mean square phase shift for periodic composites from the diffusion eigenstates, which were calculated using a previously developed Fourier expansion method. The enhanced relaxation rate depends on the echo spacing time tau in a way that can be correlated with important length scales of the porous microstructure. Those correlations can be extended also to disordered microstructures, like the ones that are found in natural rocks. We compare these theoretically predicted correlations with CPMG measurements performed on protons in laboratory samples of brine saturated sandstone. PMID:8970094

  17. Maximum proton kinetic energy and patient-generated neutron fluence considerations in proton beam arc delivery radiation therapy.

    PubMed

    Sengbusch, E; Pérez-Andújar, A; DeLuca, P M; Mackie, T R

    2009-02-01

    Several compact proton accelerator systems for use in proton therapy have recently been proposed. Of paramount importance to the development of such an accelerator system is the maximum kinetic energy of protons, immediately prior to entry into the patient, that must be reached by the treatment system. The commonly used value for the maximum kinetic energy required for a medical proton accelerator is 250 MeV, but it has not been demonstrated that this energy is indeed necessary to treat all or most patients eligible for proton therapy. This article quantifies the maximum kinetic energy of protons, immediately prior to entry into the patient, necessary to treat a given percentage of patients with rotational proton therapy, and examines the impact of this energy threshold on the cost and feasibility of a compact, gantry-mounted proton accelerator treatment system. One hundred randomized treatment plans from patients treated with IMRT were analyzed. The maximum radiological pathlength from the surface of the patient to the distal edge of the treatment volume was obtained for 180 degrees continuous arc proton therapy and for 180 degrees split arc proton therapy (two 90 degrees arcs) using CT# profiles from the Pinnacle (Philips Medical Systems, Madison, WI) treatment planning system. In each case, the maximum kinetic energy of protons, immediately prior to entry into the patient, that would be necessary to treat the patient was calculated using proton range tables for various media. In addition, Monte Carlo simulations were performed to quantify neutron production in a water phantom representing a patient as a function of the maximum proton kinetic energy achievable by a proton treatment system. Protons with a kinetic energy of 240 MeV, immediately prior to entry into the patient, were needed to treat 100% of patients in this study. However, it was shown that 90% of patients could be treated at 198 MeV, and 95% of patients could be treated at 207 MeV. Decreasing the

  18. Maximum proton kinetic energy and patient-generated neutron fluence considerations in proton beam arc delivery radiation therapy

    SciTech Connect

    Sengbusch, E.; Perez-Andujar, A.; DeLuca, P. M. Jr.; Mackie, T. R.

    2009-02-15

    Several compact proton accelerator systems for use in proton therapy have recently been proposed. Of paramount importance to the development of such an accelerator system is the maximum kinetic energy of protons, immediately prior to entry into the patient, that must be reached by the treatment system. The commonly used value for the maximum kinetic energy required for a medical proton accelerator is 250 MeV, but it has not been demonstrated that this energy is indeed necessary to treat all or most patients eligible for proton therapy. This article quantifies the maximum kinetic energy of protons, immediately prior to entry into the patient, necessary to treat a given percentage of patients with rotational proton therapy, and examines the impact of this energy threshold on the cost and feasibility of a compact, gantry-mounted proton accelerator treatment system. One hundred randomized treatment plans from patients treated with IMRT were analyzed. The maximum radiological pathlength from the surface of the patient to the distal edge of the treatment volume was obtained for 180 deg. continuous arc proton therapy and for 180 deg. split arc proton therapy (two 90 degree sign arcs) using CT profiles from the Pinnacle (Philips Medical Systems, Madison, WI) treatment planning system. In each case, the maximum kinetic energy of protons, immediately prior to entry into the patient, that would be necessary to treat the patient was calculated using proton range tables for various media. In addition, Monte Carlo simulations were performed to quantify neutron production in a water phantom representing a patient as a function of the maximum proton kinetic energy achievable by a proton treatment system. Protons with a kinetic energy of 240 MeV, immediately prior to entry into the patient, were needed to treat 100% of patients in this study. However, it was shown that 90% of patients could be treated at 198 MeV, and 95% of patients could be treated at 207 MeV. Decreasing the

  19. Maximum proton kinetic energy and patient-generated neutron fluence considerations in proton beam arc delivery radiation therapy

    PubMed Central

    Sengbusch, E.; Pérez-Andújar, A.; DeLuca, P. M.; Mackie, T. R.

    2009-01-01

    Several compact proton accelerator systems for use in proton therapy have recently been proposed. Of paramount importance to the development of such an accelerator system is the maximum kinetic energy of protons, immediately prior to entry into the patient, that must be reached by the treatment system. The commonly used value for the maximum kinetic energy required for a medical proton accelerator is 250 MeV, but it has not been demonstrated that this energy is indeed necessary to treat all or most patients eligible for proton therapy. This article quantifies the maximum kinetic energy of protons, immediately prior to entry into the patient, necessary to treat a given percentage of patients with rotational proton therapy, and examines the impact of this energy threshold on the cost and feasibility of a compact, gantry-mounted proton accelerator treatment system. One hundred randomized treatment plans from patients treated with IMRT were analyzed. The maximum radiological pathlength from the surface of the patient to the distal edge of the treatment volume was obtained for 180° continuous arc proton therapy and for 180° split arc proton therapy (two 90° arcs) using CT# profiles from the Pinnacle™ (Philips Medical Systems, Madison, WI) treatment planning system. In each case, the maximum kinetic energy of protons, immediately prior to entry into the patient, that would be necessary to treat the patient was calculated using proton range tables for various media. In addition, Monte Carlo simulations were performed to quantify neutron production in a water phantom representing a patient as a function of the maximum proton kinetic energy achievable by a proton treatment system. Protons with a kinetic energy of 240 MeV, immediately prior to entry into the patient, were needed to treat 100% of patients in this study. However, it was shown that 90% of patients could be treated at 198 MeV, and 95% of patients could be treated at 207 MeV. Decreasing the proton kinetic

  20. Proton content and nature in perovskite ceramic membranes for medium temperature fuel cells and electrolysers.

    PubMed

    Colomban, Philippe; Zaafrani, Oumaya; Slodczyk, Aneta

    2012-07-25

    Recent interest in environmentally friendly technology has promoted research on green house gas-free devices such as water steam electrolyzers, fuel cells and CO2/syngas converters. In such applications, proton conducting perovskite ceramics appear especially promising as electrolyte membranes. Prior to a successful industrial application, it is necessary to determine/understand their complex physical and chemical behavior, especially that related to proton incorporation mechanism, content and nature of bulk protonic species. Based on the results of quasi-elastic neutron scattering (QNS), thermogravimetric analysis (TGA), Raman and IR measurements we will show the complexity of the protonation process and the importance of differentiation between the protonic species adsorbed on a membrane surface and the bulk protons. The bulk proton content is very low, with a doping limit (~1-5 × 10-3 mole/mole), but sufficient to guarantee proton conduction below 600 °C. The bulk protons posses an ionic, covalent bond free nature and may occupy an interstitial site in the host perovskite structure.

  1. Comprehensive description of J/ψ production in proton-proton collisions at collider energies

    DOE PAGES

    Ma, Yan -Qing; Venugopalan, Raju

    2014-11-04

    We employ a small x Color Glass Condensate + Non-Relativistic QCD (NRQCD) formalism to compute J/ψ production at low p⊥ in proton-proton collisions at collider energies. Very good agreement is obtained for total cross-sections, rapidity distributions and low momentum p⊥ distributions. Similar agreement is obtained for ψ' production. We observe an overlap region in p⊥ where our results match smoothly to those obtained in a next-to-leading order (NLO) collinearly factorized NRQCD formalism. The relative contribution of color singlet and color octet contributions can be quantified in the CGC+NRQCD framework, with the former contributing approximately 10% of the total cross-section.

  2. High-energy test of proton radiography concepts

    SciTech Connect

    Amann, J.F.; Atencio, L.G.; Espinoza, C.J.

    1997-07-01

    This is the final report of a one-year, Laboratory-Directed Research and Development (LDRD) project at the Los Alamos National Laboratory (LANL). The goal of this work was to demonstrate the use of high energy protons to produce radiographs of heavy metal test objects. The authors executed a proof-of-principle experiment using GeV proton beams available at the Brookhaven National Laboratory Alternating Gradient Synchrotron (AGS). The experiment produced proton radiographs of a suitably dense, unclassified test object. The experiment tested capabilities in data collection, image reconstruction, and hydro-code simulation and validated models of high-energy proton radiography. A lens was designed using existing quadrupole magnets, constructed on the A1 beam line of the AGS and used to image 10-GeV protons. The results include: (1) images made with an integrating detector, (2) measurements of the background and measurements of the resolution functions, and (3) forward model fits to the transmission data. In all cases the results agree with initial estimates and provide strong support for the utility of proton radiography as a new hydrotest diagnostic.

  3. Energy Dependence of SEP Electron and Proton Onset Times

    NASA Astrophysics Data System (ADS)

    Makela, P. A.; Xie, H.; Gopalswamy, N.; St Cyr, O. C.

    2015-12-01

    We study the large solar energetic particle (SEP) events that were detected by GOES in the > 10 MeV energy channel during December 2006 to March 2014. Using multi-spacecraft observations from STEREO A, B and SOHO, we are able to determine accurately the solar particle release (SPR) time of SEP electrons and protons. We first compute connection angles (CA) between the solar events and magnetic foot-points connecting to each spacecraft. By choosing the smallest CA, we derive the electron and proton SPRs using electron fluxes from the SOHO Electron Proton and Helium Instrument (EPHIN), proton fluxes from the SOHO Energetic and Relativistic Nuclei and Electron instrument (ERNE), and from the High Energy Telescope (HET) on STEREO. It is found that: 1) the 0.25 MeV-0.7 MeV electron SPRs are ~10 min earlier than 2.64 MeV - 10.4 Mev electron SPRs; 2) the proton SPRs inferred from high-energy channels (> 50 MeV) are similar to electron SPRs; 3) the proton SPRs inferred from lower energy channel (10 - 16.9 MeV) can be either ~ 7 min earlier than or delayed from the electron SPRs for tens of minutes to hours, especially for SEPs with large pre-event background flux levels. In this study, we evaluated the effects of large scattering and high background levels on SPRs and made suggested corrections for the background effect on SPR times. We also find that for some large SEP events, the observed EPHIN electron and ERNE proton intensity profiles show a double-peak feature. The onset of the first peak corresponds well to the associated Type III and metric Type II onset and tends to be nearly scattering-free.

  4. Beam-beam interaction study of medium energy eRHIC

    SciTech Connect

    Hao,Y.; Litvinenko, V. N.; Ptitsyn, V.

    2009-07-15

    Medium Energy eRHIC (MeRHIC), the first stage design of eRHIC, includes a multi-pass ERL that provides 4GeV high quality electron beam to collide with the ion beam of RHIC. It delivers a minimum luminosity of 10{sup 32} cm{sup -2}s{sup -1}. Beam-beam effects present one of major factors limiting the luminosity of colliders. In this paper, both beam-beam effects on the electron beam and the proton beam in MeRHIC are investigated. The beam-beam interaction can induce a head-tail type instability of the proton beam referred to as the kink instability. Thus, beam stability conditions should be established to avoid proton beam loss. Also, the electron beam transverse disruption by collisions has to be evaluated to ensure that the beam quality is good enough for the energy recovery pass. The relation of proton beam stability, electron disruption and consequential luminosity are carried out after thorough discussion.

  5. Direct Versus Diffusive Access of High-Energy Solar Protons Into the High-Latitude Atmosphere

    NASA Astrophysics Data System (ADS)

    Kouznetsov, Alexei; Knudsen, David; Spanswick, Emma; Donovan, Eric

    During solar proton events (SPEs), large fluxes of energetic protons spreading throughout the interplanetary medium (IPM)have access to the upper polar atmosphere where they play important roles in physical and chemical processes. We examine the relation between SPEs as detected through ionospheric absorption measured by the NORSTAR riometer network on one hand, and the proton fluxes measured outside the magnetosphere by the SOHO satellite on the other. We find a high correlation between SOHO fluxes and absorptions in some type of events (those having insignificant electron precipitation and background radio noise) and at given time intervals (within tens of hours following times of maximum flux ) but not others. By using a numerical simulation of high-energy proton propagation through the earth's magnetosphere we show that the flux of SPE particles reaching the upper atmosphere depends strongly on the angular distribution of the source population outside of the magnetosphere. Early in SP events, protons follow solar magnetic field lines and their distributions tend to be highly anisotropic(1), and the strong angular dependence decreases the correlation between IPM fluxes and polar cap absorption. As individual events evolve, flux angular distributions of IPM protons tend to be more isotropic(1) due to encounters with randomly distributed fields of magnetic clouds in the interplanetary medium (obtained closed solution of non-steady-state diffusion equation in P1-approximation allows us to estimate the dynamics of angular modulation). It is only when this diffusive isotropization occurs that we see strong correlations (correlation coefficients of up to 0.98) between IPM fluxes observed at SOHO and the polar cap absorptions observed by the NORSTAR riometers. We aim to use these observations to construct and validate a realistic transport model that will map proton fluxes originating outside the magnetosphere to those incident on the upper atmosphere, and vice versa

  6. Intermediate energy proton-deuteron elastic scattering

    NASA Technical Reports Server (NTRS)

    Wilson, J. W.

    1973-01-01

    A fully symmetrized multiple scattering series is considered for the description of proton-deuteron elastic scattering. An off-shell continuation of the experimentally known twobody amplitudes that retains the exchange symmeteries required for the calculation is presented. The one boson exchange terms of the two body amplitudes are evaluated exactly in this off-shell prescription. The first two terms of the multiple scattering series are calculated explicitly whereas multiple scattering effects are obtained as minimum variance estimates from the 146-MeV data of Postma and Wilson. The multiple scattering corrections indeed consist of low order partial waves as suggested by Sloan based on model studies with separable interactions. The Hamada-Johnston wave function is shown consistent with the data for internucleon distances greater than about 0.84 fm.

  7. Energy distribution of proton microbeam transmitted through two flat plates

    NASA Astrophysics Data System (ADS)

    Nagy, G. U. L.; Rajta, I.; Bereczky, R. J.; Tőkési, K.

    2015-07-01

    The transmission of 1 MeV proton microbeam passing between two parallel flat plates was investigated. Three different materials were used in our experiments. As insulators we used Polytetrafluoroethylene and borosilicate glass plates and glass with gold layer on the surface as conductor. The surface of the plates was parallel to the beam axis and one of the plates was moved towards the beam. The energy distribution and the deflection of the transmitted beam were measured as the function of the sample distance relative to the beam. We found systematic differences between the behaviour of the metallic and insulator samples. The proton microbeam suffered significant deflection towards the sample surface due to the image acceleration when using conductor material. In case of the glass and Polytetrafluoroethylene plates the beam was deflected into the opposite direction, and the incident protons did not suffer significant energy loss, which is the consequence of the guiding effect.

  8. Energy dependence of the ridge in high multiplicity proton-proton collisions

    DOE PAGES

    Dusling, Kevin; Tribedy, Prithwish; Venugopalan, Raju

    2016-01-27

    In this study, we demonstrate that the recent measurement of azimuthally collimated, long-range rapidity (“ridge”) correlations in √s=13 TeV proton-proton (p+p) collisions by the ATLAS Collaboration at the LHC are in agreement with expectations from the color glass condensate effective theory of high-energy QCD. The observation that the integrated near-side yield as a function of multiplicity is independent of collision energy is a natural consequence of the fact that multiparticle production is driven by a single semihard saturation scale in the color glass condensate framework. We argue further that the azimuthal structure of these recent ATLAS ridge measurements strongly constrainsmore » hydrodynamic interpretations of such correlations in high-multiplicity p+p collisions.« less

  9. CGC/saturation approach for high energy soft interactions: v2 in proton-proton collisions

    NASA Astrophysics Data System (ADS)

    Gotsman, E.; Levin, E.; Maor, U.; Tapia, S.

    2016-04-01

    In this paper we continue our program to construct a model for high energy soft interactions, based on the CGC/saturation approach. We demonstrate that in our model, which describes diffractive physics as well as multiparticle production at high energy, the density variation mechanism leads to the value of v2 , which is about 60%-70% of the measured v2 . Bearing in mind that in the CGC/saturation approach there are two other mechanisms present, Bose enhancement in the wave function and local anisotropy, we believe that the azimuthal long range rapidity correlations in proton-proton collisions stem from the CGC/saturation physics, and not from quark-gluon plasma production.

  10. Energy dependence of the ridge in high multiplicity proton-proton collisions

    NASA Astrophysics Data System (ADS)

    Dusling, Kevin; Tribedy, Prithwish; Venugopalan, Raju

    2016-01-01

    We demonstrate that the recent measurement of azimuthally collimated, long-range rapidity ("ridge") correlations in √{s }=13 TeV proton-proton (p +p ) collisions by the ATLAS Collaboration at the LHC are in agreement with expectations from the color glass condensate effective theory of high-energy QCD. The observation that the integrated near-side yield as a function of multiplicity is independent of collision energy is a natural consequence of the fact that multiparticle production is driven by a single semihard saturation scale in the color glass condensate framework. We argue further that the azimuthal structure of these recent ATLAS ridge measurements strongly constrains hydrodynamic interpretations of such correlations in high-multiplicity p +p collisions.

  11. Low energy proton bidirectional anisotropies and their relation to transient interplanetary magnetic structures: ISEE-3 observations

    NASA Technical Reports Server (NTRS)

    Marsden, R. G.; Sanderson, T. R.; Wenzel, K. P.; Smith, E. J.

    1985-01-01

    It is known that the interplanetary medium in the period approaching solar maximum is characterized by an enhancement in the occurrence of transient solar wind streams and shocks and that such systems are often associated with looplike magnetic structures or clouds. There is observational evidence that bidirectional, field aligned flows of low energy particles could be a signature of such looplike structures, although detailed models for the magnetic field configuration and injection mechanisms do not exist at the current time. Preliminary results of a survey of low energy proton bidirectional anisotropies measured on ISEE-3 in the interplanetary medium between August 1978 and May 1982, together with magnetic field data from the same spacecraft are presented.

  12. Linear energy relationships in ground state proton transfer and excited state proton-coupled electron transfer.

    PubMed

    Gamiz-Hernandez, Ana P; Magomedov, Artiom; Hummer, Gerhard; Kaila, Ville R I

    2015-02-12

    Proton-coupled electron transfer (PCET) processes are elementary chemical reactions involved in a broad range of radical and redox reactions. Elucidating fundamental PCET reaction mechanisms are thus of central importance for chemical and biochemical research. Here we use quantum chemical density functional theory (DFT), time-dependent density functional theory (TDDFT), and the algebraic diagrammatic-construction through second-order (ADC(2)) to study the mechanism, thermodynamic driving force effects, and reaction barriers of both ground state proton transfer (pT) and photoinduced proton-coupled electron transfer (PCET) between nitrosylated phenyl-phenol compounds and hydrogen-bonded t-butylamine as an external base. We show that the obtained reaction barriers for the ground state pT reactions depend linearly on the thermodynamic driving force, with a Brønsted slope of 1 or 0. Photoexcitation leads to a PCET reaction, for which we find that the excited state reaction barrier depends on the thermodynamic driving force with a Brønsted slope of 1/2. To support the mechanistic picture arising from the static potential energy surfaces, we perform additional molecular dynamics simulations on the excited state energy surface, in which we observe a spontaneous PCET between the donor and the acceptor groups. Our findings suggest that a Brønsted analysis may distinguish the ground state pT and excited state PCET processes.

  13. Comprehensive description of J/ψ production in proton-proton collisions at collider energies.

    PubMed

    Ma, Yan-Qing; Venugopalan, Raju

    2014-11-01

    We employ a small x color glass condensate (CGC)+ nonrelativistic QCD (NRQCD) formalism to compute J/ψ production at low p(⊥) in proton-proton collisions at collider energies. Very good agreement is obtained for total cross sections, rapidity distributions, and low momentum p(⊥) distributions. Similar agreement is obtained for ψ' production. We observe an overlap region in p(⊥) where our results match smoothly to those obtained in a next-to-leading order collinearly factorized NRQCD formalism. The relative contribution of color singlet and color octet contributions can be quantified in the CGC+NRQCD framework, with the former contributing approximately 10% of the total cross section.

  14. Comprehensive description of J/ψ production in proton-proton collisions at collider energies.

    PubMed

    Ma, Yan-Qing; Venugopalan, Raju

    2014-11-01

    We employ a small x color glass condensate (CGC)+ nonrelativistic QCD (NRQCD) formalism to compute J/ψ production at low p(⊥) in proton-proton collisions at collider energies. Very good agreement is obtained for total cross sections, rapidity distributions, and low momentum p(⊥) distributions. Similar agreement is obtained for ψ' production. We observe an overlap region in p(⊥) where our results match smoothly to those obtained in a next-to-leading order collinearly factorized NRQCD formalism. The relative contribution of color singlet and color octet contributions can be quantified in the CGC+NRQCD framework, with the former contributing approximately 10% of the total cross section. PMID:25415899

  15. Proton-proton, pion-proton and pion-pion diffractive collisions at ultrahigh energies

    NASA Astrophysics Data System (ADS)

    Anisovich, V. V.; Nikonov, K. V.; Nikonov, V. A.; Nyiri, J.

    2014-05-01

    The LHC energies are those at which the asymptotic regime in hadron-hadron diffractive collisions (pp, πp, ππ) might be switched on. Based on results of the Dakhno-Nikonov eikonal model which is a generalization of the Good-Walker eikonal approach for a continuous set of channels, we present a picture for transformation of the constituent quark mode to the black disk one. In the black disk mode (√ {s} >= 10 TeV), we have a growth of the logarithm squared type for total and elastic cross-sections, σtot ln2 s and σel ln2 s and (τ = q⊥2&sigma_; tot)-scaling for diffractive scattering and diffractive dissociation of hadrons. The diffractive dissociation cross-section grows as σD ln s, σDD ln s, and their relative contribution tends to zero: σD/σtot → 0, σDD/σtot → 0. Asymptotic characteristics of diffractive and total cross-sections are universal, and this results in the asymptotical equality of cross-sections for all types of hadrons (the Gribov universality). The energy scale for switching on the asymptotic mode is estimated for different processes.

  16. The practical Pomeron for high energy proton collimation

    NASA Astrophysics Data System (ADS)

    Appleby, R. B.; Barlow, R. J.; Molson, J. G.; Serluca, M.; Toader, A.

    2016-10-01

    We present a model which describes proton scattering data from ISR to Tevatron energies, and which can be applied to collimation in high energy accelerators, such as the LHC and FCC. Collimators remove beam halo particles, so that they do not impinge on vulnerable regions of the machine, such as the superconducting magnets and the experimental areas. In simulating the effect of the collimator jaws it is crucial to model the scattering of protons at small momentum transfer t, as these protons can subsequently survive several turns of the ring before being lost. At high energies these soft processes are well described by Pomeron exchange models. We study the behaviour of elastic and single-diffractive dissociation cross sections over a wide range of energy, and show that the model can be used as a global description of the wide variety of high energy elastic and diffractive data presently available. In particular it models low mass diffraction dissociation, where a rich resonance structure is present, and thus predicts the differential and integrated cross sections in the kinematical range appropriate to the LHC. We incorporate the physics of this model into the beam tracking code MERLIN and use it to simulate the resulting loss maps of the beam halo lost in the collimators in the LHC.

  17. Proton Linear Energy Transfer measurement using Emulsion Cloud Chamber

    NASA Astrophysics Data System (ADS)

    Shin, Jae-ik; Park, Seyjoon; Kim, Haksoo; Kim, Meyoung; Jeong, Chiyoung; Cho, Sungkoo; Lim, Young Kyung; Shin, Dongho; Lee, Se Byeong; Morishima, Kunihiro; Naganawa, Naotaka; Sato, Osamu; Kwak, Jungwon; Kim, Sung Hyun; Cho, Jung Sook; Ahn, Jung Keun; Kim, Ji Hyun; Yoon, Chun Sil; Incerti, Sebastien

    2015-04-01

    This study proposes to determine the correlation between the Volume Pulse Height (VPH) measured by nuclear emulsion and Linear Energy Transfer (LET) calculated by Monte Carlo simulation based on Geant4. The nuclear emulsion was irradiated at the National Cancer Center (NCC) with a therapeutic proton beam and was installed at 5.2 m distance from the beam nozzle structure with various thicknesses of water-equivalent material (PMMA) blocks to position with specific positions along the Bragg curve. After the beam exposure and development of the emulsion films, the films were scanned by S-UTS developed in Nagoya University. The proton tracks in the scanned films were reconstructed using the 'NETSCAN' method. Through this procedure, the VPH can be derived from each reconstructed proton track at each position along the Bragg curve. The VPH value indicates the magnitude of energy loss in proton track. By comparison with the simulation results obtained using Geant4, we found the correlation between the LET calculated by Monte Carlo simulation and the VPH measured by the nuclear emulsion.

  18. Implications of gamma-ray observations on proton models of ultrahigh energy cosmic rays

    NASA Astrophysics Data System (ADS)

    Supanitsky, A. D.

    2016-09-01

    The origin of ultrahigh energy cosmic rays (UHECR) is still unknown. However, great progress has been achieved in past years due to the good quality and large statistics in experimental data collected by the current observatories. The data of the Pierre Auger Observatory show that the composition of UHECRs becomes progressively lighter starting from 1 017 eV up to ˜1 018.3 eV and then, beyond that energy, it becomes increasingly heavier. These analyses are subject to important systematic uncertainties due to the use of hadronic interaction models that extrapolate lower energy accelerator data to the highest energies. Although proton models of UHECRs are disfavored by these results, they cannot be completely ruled out. It is well known that the energy spectra of gamma rays and neutrinos, produced during propagation of these very energetic particles through the intergalactic medium, are a useful tool to constrain the spectrum models. In particular, it has recently been shown that the neutrino upper limits obtained by IceCube challenge the proton models at 95% C.L. In this work we study the constraints imposed by the extragalactic gamma-ray background, measured by Fermi-LAT, on proton models of UHECRs. In particular, we make use of the extragalactic gamma-ray background flux, integrated from 50 GeV to 2 TeV, that originates in point sources, which has recently been obtained by the Fermi-LAT Collaboration, in combination with the neutrino upper limits, to constrain the emission of UHECRs at high redshifts (z >1 ), in the context of the proton models.

  19. Analytical calculation of proton linear energy transfer in voxelized geometries including secondary protons

    NASA Astrophysics Data System (ADS)

    Sanchez-Parcerisa, D.; Cortés-Giraldo, M. A.; Dolney, D.; Kondrla, M.; Fager, M.; Carabe, A.

    2016-02-01

    In order to integrate radiobiological modelling with clinical treatment planning for proton radiotherapy, we extended our in-house treatment planning system FoCa with a 3D analytical algorithm to calculate linear energy transfer (LET) in voxelized patient geometries. Both active scanning and passive scattering delivery modalities are supported. The analytical calculation is much faster than the Monte-Carlo (MC) method and it can be implemented in the inverse treatment planning optimization suite, allowing us to create LET-based objectives in inverse planning. The LET was calculated by combining a 1D analytical approach including a novel correction for secondary protons with pencil-beam type LET-kernels. Then, these LET kernels were inserted into the proton-convolution-superposition algorithm in FoCa. The analytical LET distributions were benchmarked against MC simulations carried out in Geant4. A cohort of simple phantom and patient plans representing a wide variety of sites (prostate, lung, brain, head and neck) was selected. The calculation algorithm was able to reproduce the MC LET to within 6% (1 standard deviation) for low-LET areas (under 1.7 keV μm-1) and within 22% for the high-LET areas above that threshold. The dose and LET distributions can be further extended, using radiobiological models, to include radiobiological effectiveness (RBE) calculations in the treatment planning system. This implementation also allows for radiobiological optimization of treatments by including RBE-weighted dose constraints in the inverse treatment planning process.

  20. Analytical calculation of proton linear energy transfer in voxelized geometries including secondary protons.

    PubMed

    Sanchez-Parcerisa, D; Cortés-Giraldo, M A; Dolney, D; Kondrla, M; Fager, M; Carabe, A

    2016-02-21

    In order to integrate radiobiological modelling with clinical treatment planning for proton radiotherapy, we extended our in-house treatment planning system FoCa with a 3D analytical algorithm to calculate linear energy transfer (LET) in voxelized patient geometries. Both active scanning and passive scattering delivery modalities are supported. The analytical calculation is much faster than the Monte-Carlo (MC) method and it can be implemented in the inverse treatment planning optimization suite, allowing us to create LET-based objectives in inverse planning. The LET was calculated by combining a 1D analytical approach including a novel correction for secondary protons with pencil-beam type LET-kernels. Then, these LET kernels were inserted into the proton-convolution-superposition algorithm in FoCa. The analytical LET distributions were benchmarked against MC simulations carried out in Geant4. A cohort of simple phantom and patient plans representing a wide variety of sites (prostate, lung, brain, head and neck) was selected. The calculation algorithm was able to reproduce the MC LET to within 6% (1 standard deviation) for low-LET areas (under 1.7 keV μm(-1)) and within 22% for the high-LET areas above that threshold. The dose and LET distributions can be further extended, using radiobiological models, to include radiobiological effectiveness (RBE) calculations in the treatment planning system. This implementation also allows for radiobiological optimization of treatments by including RBE-weighted dose constraints in the inverse treatment planning process.

  1. Low-energy proton capture reactions

    SciTech Connect

    Lipoglavsek, M.; Cvetinovic, A.; Gajevic, J.; Likar, A.; Vavpetic, P.; Petrovic, T.

    2014-05-09

    An overview of experimental problems in measuring the cross sections for (p,γ) and (p,n) reactions at low energies is given with a specific emphasis on electron screening in metallic targets. Thick target γ-ray and neutron yields are compared for Ni and NiO targets, V and VO{sub 2} targets and Mn and MnO targets. The {sup 1}H({sup 7}Li,α){sup 4}He reaction was studied in inverse kinematics with hydrogen loaded into Pd and PdAg alloy foils from gas phase. Based on these results, a new approach to electron screening in nuclear reactions is suggested.

  2. MCNP6 Simulation of Light and Medium Nuclei Fragmentation at Intermediate Energies

    SciTech Connect

    Mashnik, Stepan Georgievich; Kerby, Leslie Marie

    2015-08-24

    Fragmentation reactions induced on light and medium nuclei by protons and light nuclei of energies around 1 GeV/nucleon and below are studied with the Los Alamos transport code MCNP6 and with its CEM03.03 and LAQGSM03.03 event generators. CEM and LAQGSM assume that intermediate-energy fragmentation reactions on light nuclei occur generally in two stages. The first stage is the intranuclear cascade (INC), followed by the second, Fermi breakup disintegration of light excited residual nuclei produced after the INC. CEM and LAQGSM account also for coalescence of light fragments (complex particles) up to sup>4He from energetic nucleons emitted during INC. We investigate the validity and performance of MCNP6, CEM, and LAQGSM in simulating fragmentation reactions at intermediate energies and discuss possible ways of further improving these codes.

  3. MCNP6 simulation of light and medium nuclei fragmentation at intermediate energies

    NASA Astrophysics Data System (ADS)

    Mashnik, Stepan G.; Kerby, Leslie M.

    2016-05-01

    Fragmentation reactions induced on light and medium nuclei by protons and light nuclei of energies around 1 GeV/nucleon and below are studied with the Los Alamos transport code MCNP6 and with its CEM03.03 and LAQGSM03.03 event generators. CEM and LAQGSM assume that intermediate-energy fragmentation reactions on light nuclei occur generally in two stages. The first stage is the intranuclear cascade (INC), followed by the second, Fermi breakup disintegration of light excited residual nuclei produced after the INC. CEM and LAQGSM account also for coalescence of light fragments (complex particles) up to 4He from energetic nucleons emitted during INC. We investigate the validity and performance of MCNP6, CEM, and LAQGSM in simulating fragmentation reactions at intermediate energies and discuss possible ways of further improving these codes.

  4. The Design of a Large Booster Ring for the Medium Energy Electron-Ion Collider at Jlab

    SciTech Connect

    Edward Nissen, Todd Satogata, Yuhong Zhang

    2012-07-01

    In this paper, we present the current design of the large booster ring for the Medium energy Electron-Ion Collider at Jefferson Lab. The booster ring takes 3 GeV protons or ions of equivalent rigidity from a pre-booster ring, and accelerates them to 20 GeV for protons or equivalent energy for light to heavy ions before sending them to the ion collider ring. The present design calls for a figure-8 shape of the ring for superior preservation of ion polarization. The ring is made of warm magnets and shares a tunnel with the two collider rings. Acceleration is achieved by warm RF systems. The linear optics has been designed with the transition energy above the highest beam energy in the ring so crossing of transition energy will be avoided. Preliminary beam dynamics studies including chromaticity compensation are presented in this paper.

  5. Electrochemical cells for medium- and large-scale energy storage

    SciTech Connect

    Wang, Wei; Wei, Xiaoliang; Choi, Daiwon; Lu, Xiaochuan; Yang, G.; Sun, C.

    2014-12-12

    This is one of the chapters in the book titled “Advances in batteries for large- and medium-scale energy storage: Applications in power systems and electric vehicles” that will be published by the Woodhead Publishing Limited. The chapter discusses the basic electrochemical fundamentals of electrochemical energy storage devices with a focus on the rechargeable batteries. Several practical secondary battery systems are also discussed as examples

  6. An Assessment of Nuclear Isomers as an Energy Storage Medium

    SciTech Connect

    Hartouni, E P

    2008-12-08

    Nuclear Isomers have been suggested as a potential high energy density medium that might be used to store energy. This talk assesses the state of the science supporting key elements of using nuclear isomers in energy storage applications. The focus is on the nuclear isomer {sup 178m2}Hf which has been most widely suggested for energy storage applications. However, the science issues apply to all nuclear isomer. The assessment addresses the production of the nuclear isomer, and inducing the release of the isomer. Also discussed are novel speculations on photon and/or neutron chain reactions, both as a 'pure' material as well as mixed with other materials.

  7. An Assessment of Nuclear Isomers as an Energy Storage Medium

    SciTech Connect

    Hartouni, Edward P.

    2009-03-16

    Nuclear Isomers have been suggested as a potential high energy density medium that might be used to store energy. This talk assesses the state of the science supporting key elements of using nuclear isomers in energy storage applications. The focus is on the nuclear isomer {sup 178m2}Hf which has been most widely suggested for energy storage applications. However, the science issues apply to all nuclear isomer. The assessment addresses the production of the nuclear isomer, and inducing the release of the isomer. Also discussed are novel speculations on photon and/or neutron chain reactions, both as a 'pure' material as well as mixed with other materials.

  8. Energy flow along the medium-induced parton cascade

    NASA Astrophysics Data System (ADS)

    Blaizot, J.-P.; Mehtar-Tani, Y.

    2016-05-01

    We discuss the dynamics of parton cascades that develop in dense QCD matter, and contrast their properties with those of similar cascades of gluon radiation in vacuum. We argue that such cascades belong to two distinct classes that are characterized respectively by an increasing or a constant (or decreasing) branching rate along the cascade. In the former class, of which the BDMPS, medium-induced, cascade constitutes a typical example, it takes a finite time to transport a finite amount of energy to very soft quanta, while this time is essentially infinite in the latter case, to which the DGLAP cascade belongs. The medium induced cascade is accompanied by a constant flow of energy towards arbitrary soft modes, leading eventually to the accumulation of the initial energy of the leading particle at zero energy. It also exhibits scaling properties akin to wave turbulence. These properties do not show up in the cascade that develops in vacuum. There, the energy accumulates in the spectrum at smaller and smaller energy as the cascade develops, but the energy never flows all the way down to zero energy. Our analysis suggests that the way the energy is shared among the offsprings of a splitting gluon has little impact on the qualitative properties of the cascades, provided the kernel that governs the splittings is not too singular.

  9. A Four-fluid MHD Model of the Solar Wind/Interstellar Medium Interaction with Turbulence Transport and Pickup Protons as Separate Fluid

    NASA Astrophysics Data System (ADS)

    Usmanov, Arcadi V.; Goldstein, Melvyn L.; Matthaeus, William H.

    2016-03-01

    We have developed a four-fluid, three-dimensional magnetohydrodynamic model of the solar wind interaction with the local interstellar medium. The unique features of the model are: (a) a three-fluid description for the charged components of the solar wind and interstellar plasmas (thermal protons, electrons, and pickup protons), (b) the built-in turbulence transport equations based on Reynolds decomposition and coupled with the mean-flow Reynolds-averaged equations, and (c) a solar corona/solar wind model that supplies inner boundary conditions at 40 au by computing solar wind and magnetic field parameters outward from the coronal base. The three charged species are described by separate energy equations and are assumed to move with the same velocity. The fourth fluid in the model is the interstellar hydrogen which is treated by separate continuity, momentum, and energy equations and is coupled with the charged components through photoionization and charge exchange. We evaluate the effects of turbulence transport and pickup protons on the global heliospheric structure and compute the distribution of plasma, magnetic field, and turbulence parameters throughout the heliosphere for representative solar minimum and maximum conditions. We compare our results with Voyager 1 observations in the outer heliosheath and show that the relative amplitude of magnetic fluctuations just outside the heliopause is in close agreement with the value inferred from Voyager 1 measurements by Burlaga et al. The simulated profiles of magnetic field parameters in the outer heliosheath are in qualitative agreement with the Voyager 1 observations and with the analytical model of magnetic field draping around the heliopause of Isenberg et al.

  10. Neutrino diagnostics of ultrahigh energy cosmic ray protons

    SciTech Connect

    Ahlers, Markus; Sarkar, Subir; Anchordoqui, Luis A.

    2009-04-15

    The energy at which cosmic rays from extra-galactic sources begin to dominate over those from galactic sources is an important open question in astroparticle physics. A natural candidate is the energy at the 'ankle' in the approximately power-law energy spectrum which is indicative of a crossover from a falling galactic component to a flatter extra-galactic component. The transition can occur without such flattening but this requires some degree of conspiracy of the spectral shapes and normalizations of the two components. Nevertheless, it has been argued that extra-galactic sources of cosmic ray protons that undergo interactions on the CMB can reproduce the energy spectrum below the ankle if the crossover energy is as low as the 'second knee' in the spectrum. This low crossover model is constrained by direct measurements by the Pierre Auger Observatory, which indicate a heavier composition at these energies. We demonstrate that upper limits on the cosmic diffuse neutrino flux provide a complementary constraint on the proton fraction in ultra-high energy extra-galactic cosmic rays and forthcoming data from IceCube will provide a definitive test of this model.

  11. Advanced proton-exchange materials for energy efficient fuel cells.

    SciTech Connect

    Fujimoto, Cy H.; Grest, Gary Stephen; Hickner, Michael A.; Cornelius, Christopher James; Staiger, Chad Lynn; Hibbs, Michael R.

    2005-12-01

    The ''Advanced Proton-Exchange Materials for Energy Efficient Fuel Cells'' Laboratory Directed Research and Development (LDRD) project began in October 2002 and ended in September 2005. This LDRD was funded by the Energy Efficiency and Renewable Energy strategic business unit. The purpose of this LDRD was to initiate the fundamental research necessary for the development of a novel proton-exchange membranes (PEM) to overcome the material and performance limitations of the ''state of the art'' Nafion that is used in both hydrogen and methanol fuel cells. An atomistic modeling effort was added to this LDRD in order to establish a frame work between predicted morphology and observed PEM morphology in order to relate it to fuel cell performance. Significant progress was made in the area of PEM material design, development, and demonstration during this LDRD. A fundamental understanding involving the role of the structure of the PEM material as a function of sulfonic acid content, polymer topology, chemical composition, molecular weight, and electrode electrolyte ink development was demonstrated during this LDRD. PEM materials based upon random and block polyimides, polybenzimidazoles, and polyphenylenes were created and evaluated for improvements in proton conductivity, reduced swelling, reduced O{sub 2} and H{sub 2} permeability, and increased thermal stability. Results from this work reveal that the family of polyphenylenes potentially solves several technical challenges associated with obtaining a high temperature PEM membrane. Fuel cell relevant properties such as high proton conductivity (>120 mS/cm), good thermal stability, and mechanical robustness were demonstrated during this LDRD. This report summarizes the technical accomplishments and results of this LDRD.

  12. Deuteron-proton elastic scattering at intermediate energies

    SciTech Connect

    Ladygina, N. B.

    2008-12-15

    The deuteron-proton elastic scattering has been studied in the multiple-scattering expansion formalism. Primary attention has been given to such relativistic problems as a deuteron wave function in a moving frame and transformation of spin states due to Wigner rotation. Parametrization of the nucleon-nucleon t matrix has been used to take the off-energy-shell effects into account. The vector, A{sub y}, and tensor, A{sub yy}, analyzing powers of the deuteron have been calculated at two deuteron kinetic energies: 395 and 1200 MeV. The obtained results are compared with the experimental data.

  13. Prototyping of beam position monitor for medium energy beam transport section of RAON heavy ion accelerator

    NASA Astrophysics Data System (ADS)

    Jang, Hyojae; Jin, Hyunchang; Jang, Ji-Ho; Hong, In-Seok

    2016-02-01

    A heavy ion accelerator, RAON is going to be built by Rare Isotope Science Project in Korea. Its target is to accelerate various stable ions such as uranium, proton, and xenon from electron cyclotron resonance ion source and some rare isotopes from isotope separation on-line. The beam shaping, charge selection, and modulation should be applied to the ions from these ion sources because RAON adopts a superconducting linear accelerator structure for beam acceleration. For such treatment, low energy beam transport, radio frequency quadrupole, and medium energy beam transport (MEBT) will be installed in injector part of RAON accelerator. Recently, development of a prototype of stripline beam position monitor (BPM) to measure the position of ion beams in MEBT section is under way. In this presentation, design of stripline, electromagnetic (EM) simulation results, and RF measurement test results obtained from the prototyped BPM will be described.

  14. MINOS+: a Proposal to FNAL to run MINOS with the medium energy NuMI beam

    SciTech Connect

    Tzanankos, G.; Bishai, M.; Diwan, M.; Escobar, C.O.; Gomes, R.A.; Gouffon, P.; Blake, A.; Thomson, M.; Patterson, R.B.; Adamson, P.; Childress, S.; /Fermilab /IIT, Chicago /Los Alamos /Minnesota U. /Minnesota U., Duluth /Bhubaneswar, NISER /Iowa State U.

    2011-05-01

    This is a proposal to continue to expose the two MINOS detectors to the NuMI muon neutrino beam for three years starting in 2013. The medium energy setting of the NuMI beam projected for NO{nu}A will deliver about 18 x 10{sup 20} protons-on-target during the first three years of operation. This will allow the MINOS Far Detector to collect more than 10,000 charged current muon neutrino events in the 4-10 GeV energy range and provide a stringent test for non-standard neutrino interactions, sterile neutrinos, extra dimensions, neutrino time-of-flight, and perhaps more. In addition there will be more than 3,000 neutral current events which will be particularly useful in extending the sterile neutrino search range.

  15. Analytical calculation of proton linear energy transfer in voxelized geometries including secondary protons.

    PubMed

    Sanchez-Parcerisa, D; Cortés-Giraldo, M A; Dolney, D; Kondrla, M; Fager, M; Carabe, A

    2016-02-21

    In order to integrate radiobiological modelling with clinical treatment planning for proton radiotherapy, we extended our in-house treatment planning system FoCa with a 3D analytical algorithm to calculate linear energy transfer (LET) in voxelized patient geometries. Both active scanning and passive scattering delivery modalities are supported. The analytical calculation is much faster than the Monte-Carlo (MC) method and it can be implemented in the inverse treatment planning optimization suite, allowing us to create LET-based objectives in inverse planning. The LET was calculated by combining a 1D analytical approach including a novel correction for secondary protons with pencil-beam type LET-kernels. Then, these LET kernels were inserted into the proton-convolution-superposition algorithm in FoCa. The analytical LET distributions were benchmarked against MC simulations carried out in Geant4. A cohort of simple phantom and patient plans representing a wide variety of sites (prostate, lung, brain, head and neck) was selected. The calculation algorithm was able to reproduce the MC LET to within 6% (1 standard deviation) for low-LET areas (under 1.7 keV μm(-1)) and within 22% for the high-LET areas above that threshold. The dose and LET distributions can be further extended, using radiobiological models, to include radiobiological effectiveness (RBE) calculations in the treatment planning system. This implementation also allows for radiobiological optimization of treatments by including RBE-weighted dose constraints in the inverse treatment planning process. PMID:26840945

  16. Noise attenuation methods for the medium energy electron measurementsin the radiation belt

    NASA Astrophysics Data System (ADS)

    Kasahara, Satoshi; Ogasawara, Keiichi; Takashima, Takeshi; Hirahara, Masafumi; Asamura, Kazushi

    In the Earth's radiation belt, extremely energetic electrons (in the megaelectronvolt range), so-called killer electrons, are trapped; they can damage or "kill" satellites. Furthermore, they also can cause damages to human bodies. Generation mechanisms of killer electrons have been studied more than a few decades, and much progress has been made for the last decade. Theoretical studies show that killer electrons are accelerated via the cyclotron resonance with whistler chorus waves. Accordingly, the generation of whistler chorus is the key for the enhancement of killer electrons. However, excitation mechanisms of whistler chorus waves are not fully understood. Although theories predict that they are excited by medium energy electrons (5-80 keV), it is not confirmed by observations. Therefore, the simultaneous observations of medium energy electrons and whistler waves are one of the top priorities of space science communities. The combination of cusp type electrostatic analyser (CEA) and avalanche photodiode (APD) is a very promising way for the medium energy electron measurements. The novel design of CEA enables practical size of over-all system, with 2-pi rad field-of-view; one can obtain the full solid angle coverage by using a satellite spin motion. APD is a kind of p-n junction semiconductor with an internal gain, which enables reliable conversion from count rates to the true flux. In the Earth's radiation belt, however, it is significantly difficult to accurately measure electron fluxes, due to the contamination by penetrating high energy particles, such as solar protons and killer electrons. In order to solve the issue, we propose the method of noise attenuation, by using the combination of anti-coincidence and pulse height analyses. Although high energy particles are detected by APD, they can be rejected by choosing the appropriate thickness of the detector, and by analysing pulse heights. On the basis of the high energy electron irradiation test, we

  17. Heavy-quarkonium production in high energy proton-proton collisions at RHIC

    SciTech Connect

    Brodsky, Stanley J.; Lansberg, Jean-Philippe

    2010-03-01

    We update the study of the total {psi} and {Upsilon} production cross section in proton-proton collisions at RHIC energies using the QCD-based color-singlet model, including next-to-leading order partonic matrix elements. We also include charm-quark initiated processes which appear at leading order in {alpha}{sub s}, so far overlooked in such studies. Contrary to earlier claims, we show that the color-singlet yield is consistent with measurements over a broad range of J/{psi} rapidities. We find that intrinsic plus sealike charm-initiated processes contribute more than 20% of the direct J/{psi} yield. The key signature for such processes is the observation of a charm-quark jet opposite in azimuthal angle {phi} to the detected J/{psi}. Our results have impact on the proper interpretation of heavy-quarkonium production in heavy-ion collisions and its use as a probe for the quark-gluon plasma.

  18. Measurements of radiation fields around high-energy proton accelerators.

    PubMed

    Agosteo, Stefano; Silari, Marco

    2005-01-01

    Monitoring of ionising radiation around high-energy particle accelerators is a difficult task due to the complexity of the radiation field, which is made up of neutrons, charged hadrons, muons, photons and electrons, with energy spectra extending over a wide energy range. The dose-equivalent outside a thick shield is mainly owing to neutrons, with some contribution from photons and, to a minor extent, the other particles. Neutron dosimetry and spectrometry are thus of primary importance to correctly evaluate the exposure of personnel. This paper reviews the relevant techniques and instrumentation employed for monitoring radiation fields around high-energy proton accelerators, with particular emphasis on the recent development to increase the response of neutron measuring devices > 20 MeV. Rem-counters, pressurised ionisation chambers, superheated emulsions, tissue-equivalent proportional counters and Bonner sphere spectrometers are discussed. PMID:16604662

  19. Energy enhancement of proton acceleration in combinational radiation pressure and bubble by optimizing plasma density

    SciTech Connect

    Bake, Muhammad Ali; Xie Baisong; Shan Zhang; Hong Xueren; Wang Hongyu

    2012-08-15

    The combinational laser radiation pressure and plasma bubble fields to accelerate protons are researched through theoretical analysis and numerical simulations. The dephasing length of the accelerated protons bunch in the front of the bubble and the density gradient effect of background plasma on the accelerating phase are analyzed in detail theoretically. The radiation damping effect on the accelerated protons energy is also considered. And it is demonstrated by two-dimensional particle-in-cell simulations that the protons bunch energy can be increased by using the background plasma with negative density gradient. However, radiation damping makes the maximal energy of the accelerated protons a little reduction.

  20. Modulation of low energy electrons and protons near solar maximum

    NASA Technical Reports Server (NTRS)

    Lheureux, J.; Meyer, P.

    1975-01-01

    The intensities of cosmic-ray electrons in the energy range from 24 to 235 MeV and of protons in the ranges 40 to 150 MeV and greater than 700 MeV are compared with the neutron intensity data over the period 1968 to 1972. Correlation plots between these various components show a marked break following the June 9, 1969 Forbush decrease. The resulting hysteresis curve is best explained as a sudden change in the rigidity dependence of solar modulation. A variation in the size of the solar cavity is also possible but not likely.

  1. MCNP6 Simulation of Light and Medium Nuclei Fragmentation at Intermediate Energies

    SciTech Connect

    Mashnik, Stepan Georgievich; Kerby, Leslie Marie

    2015-05-22

    MCNP6, the latest and most advanced LANL Monte Carlo transport code, representing a merger of MCNP5 and MCNPX, is actually much more than the sum of those two computer codes; MCNP6 is available to the public via RSICC at Oak Ridge, TN, USA. In the present work, MCNP6 was validated and verified (V&V) against different experimental data on intermediate-energy fragmentation reactions, and results by several other codes, using mainly the latest modifications of the Cascade-Exciton Model (CEM) and of the Los Alamos version of the Quark-Gluon String Model (LAQGSM) event generators CEM03.03 and LAQGSM03.03. It was found that MCNP6 using CEM03.03 and LAQGSM03.03 describes well fragmentation reactions induced on light and medium target nuclei by protons and light nuclei of energies around 1 GeV/nucleon and below, and can serve as a reliable simulation tool for different applications, like cosmic-ray-induced single event upsets (SEU’s), radiation protection, and cancer therapy with proton and ion beams, to name just a few. Future improvements of the predicting capabilities of MCNP6 for such reactions are possible, and are discussed in this work.

  2. Dirac Calculations for Proton Inelastic Scattering at Intermediate Energies

    NASA Astrophysics Data System (ADS)

    El-Nohy, N. A.; El-Hammamy, M. N.; Aly, N. E.; Abdel-Moneim, A. M.; Hamza, A. F.

    2016-09-01

    Relativistic proton inelastic scattering from different targets (16O, 24Mg, 28Si, 40Ca, 54Fe, 58Ni, 90Zr, 154Sm, 176Yb, and 208Pb) at intermediate energies is analyzed in the framework of phenomenological optical potentials based on the Dirac formalism. Parameters of the Dirac phenomenological potential with Woods Saxon (WS) shape are obtained. The first order vibrational collective model with one phonon is used to calculate the transition optical potentials to the first low-lying excited state (2+) of the investigated target nuclei. Also, the variation of deformation length (δ) with energy and mass number is studied. It is noticed that the deformation length increases slightly with energy at intermediate range.

  3. A boron phosphate-phosphoric acid composite membrane for medium temperature proton exchange membrane fuel cells

    NASA Astrophysics Data System (ADS)

    Mamlouk, M.; Scott, K.

    2015-07-01

    A composite membrane based on a non-stoichiometric composition of BPO4 with excess of PO4 (BPOx) was synthesised and characterised for medium temperature fuel cell use (120-180 °C). The electrolyte was characterised by FTIR, SS-NMR, TGA and XRD and showed that the B-O is tetrahedral, in agreement with reports in the literature that boron phosphorus oxide compounds at B:P < 1 are exclusively built of borate and phosphate tetrahedra. Platinum micro electrodes were used to study the electrolyte compatibility and stability towards oxygen reduction at 150 °C and to obtain kinetic and mass transport parameters. The conductivities of the pure BPOx membrane electrolyte and a Polybenzimidazole (PBI)-4BPOx composite membrane were 7.9 × 10-2 S cm-1 and 4.5 × 10-2 S cm-1 respectively at 150 °C, 5%RH. Fuel cell tests showed a significant enhancement in performance of BPOx over that of typical 5.6H3PO4-PBI membrane electrolyte. The enhancement is due to the improved ionic conductivity (3×), a higher exchange current density of the oxygen reduction (30×) and a lower membrane gas permeability (10×). Fuel cell current densities at 0.6 V were 706 and 425 mA cm-2 for BPOx and 5.6H3PO4-PBI, respectively, at 150 °C with O2 (atm).

  4. Analysis of medium-energy transfers to the Moon

    NASA Astrophysics Data System (ADS)

    Oshima, Kenta; Topputo, Francesco; Campagnola, Stefano; Yanao, Tomohiro

    2016-09-01

    This study analyzes a recently discovered class of exterior transfers to the Moon. These transfers terminate in retrograde ballistic capture orbits, i.e., orbits with negative Keplerian energy and angular momentum with respect to the Moon. Yet, their Jacobi constant is relatively low, for which no forbidden regions exist, and the trajectories do not appear to mimic the dynamics of the invariant manifolds of the Lagrange points. This paper shows that these orbits shadow instead lunar collision orbits. We investigate the dynamics of singular, lunar collision orbits in the Earth-Moon planar circular restricted three-body problem, and reveal their rich phase space structure in the medium-energy regime, where invariant manifolds of the Lagrange point orbits break up. We show that lunar retrograde ballistic capture trajectories lie inside the tube structure of collision orbits. We also develop a method to compute medium-energy transfers by patching together orbits inside the collision tube and those whose apogees are located in the appropriate quadrant in the Sun-Earth system. The method yields the novel family of transfers as well as those ending in direct capture orbits, under particular energetic and geometrical conditions.

  5. An online, energy-resolving beam profile detector for laser-driven proton beams.

    PubMed

    Metzkes, J; Zeil, K; Kraft, S D; Karsch, L; Sobiella, M; Rehwald, M; Obst, L; Schlenvoigt, H-P; Schramm, U

    2016-08-01

    In this paper, a scintillator-based online beam profile detector for the characterization of laser-driven proton beams is presented. Using a pixelated matrix with varying absorber thicknesses, the proton beam is spatially resolved in two dimensions and simultaneously energy-resolved. A thin plastic scintillator placed behind the absorber and read out by a CCD camera is used as the active detector material. The spatial detector resolution reaches down to ∼4 mm and the detector can resolve proton beam profiles for up to 9 proton threshold energies. With these detector design parameters, the spatial characteristics of the proton distribution and its cut-off energy can be analyzed online and on-shot under vacuum conditions. The paper discusses the detector design, its characterization and calibration at a conventional proton source, as well as the first detector application at a laser-driven proton source. PMID:27587116

  6. An online, energy-resolving beam profile detector for laser-driven proton beams

    NASA Astrophysics Data System (ADS)

    Metzkes, J.; Zeil, K.; Kraft, S. D.; Karsch, L.; Sobiella, M.; Rehwald, M.; Obst, L.; Schlenvoigt, H.-P.; Schramm, U.

    2016-08-01

    In this paper, a scintillator-based online beam profile detector for the characterization of laser-driven proton beams is presented. Using a pixelated matrix with varying absorber thicknesses, the proton beam is spatially resolved in two dimensions and simultaneously energy-resolved. A thin plastic scintillator placed behind the absorber and read out by a CCD camera is used as the active detector material. The spatial detector resolution reaches down to ˜4 mm and the detector can resolve proton beam profiles for up to 9 proton threshold energies. With these detector design parameters, the spatial characteristics of the proton distribution and its cut-off energy can be analyzed online and on-shot under vacuum conditions. The paper discusses the detector design, its characterization and calibration at a conventional proton source, as well as the first detector application at a laser-driven proton source.

  7. Medium energy gamma ray astronomy with transpacific balloon flights

    NASA Technical Reports Server (NTRS)

    Zych, A. D.; Jennings, M. C.; White, R. S.; Dayton, B.

    1981-01-01

    Transpacific balloon flights with the University of California, Riverside (UCR) double scatter telescope are discussed. With flight durations from 5 days up to perhaps 15 days the long observation times necessary for medium energy (1-30 MeV) gamma ray astronomy can be obtained. These flights would be made under the auspices of the Joint U.S.-Japan Balloon Flight Program at NASA. It is proposed that flights can provide at least 30 hours of observation time per flight for many discrete source candidates and 120 hours for detecting low intensity cosmic gamma ray bursts.

  8. Note: Proton microbeam formation with continuously variable kinetic energy using a compact system for three-dimensional proton beam writing

    SciTech Connect

    Ohkubo, T. Ishii, Y.

    2015-03-15

    A compact focused gaseous ion beam system has been developed to form proton microbeams of a few hundreds of keV with a penetration depth of micrometer range in 3-dimensional proton beam writing. Proton microbeams with kinetic energies of 100-140 keV were experimentally formed on the same point at a constant ratio of the kinetic energy of the object side to that of the image side. The experimental results indicate that the beam diameters were measured to be almost constant at approximately 6 μm at the same point with the kinetic energy range. These characteristics of the system were experimentally and numerically demonstrated to be maintained as long as the ratio was constant.

  9. Si film separation obtained by high energy proton implantation

    SciTech Connect

    Braley, C.; Mazen, F.; Papon, A.-M.; Rieutord, F.; Charvet, A.-M.; Ntsoenzok, E.

    2012-11-06

    High energy protons implantation in the 1-1.5 MeV range can be used to detach free-standing thin silicon films with thickness between 15 and 30 {mu}m. Recently, we showed that Si orientation has a strong effect on the layer separation threshold fluence and efficiency. While complete delamination of (111)Si films is achieved, (100)Si films separation is more challenging due to blistering phenomena or partial separation of the implanted layer. In this work, we study the fracture mechanism in (100) and (111)Si after high energy implantation in order to understand the origin of such a behavior. We notably point out that fracture precursor defects, i.e. the platelets, preferentially form on (111) planes, as a consequence of the low strain level in the damaged region in our implantation conditions. Fracture therefore propagates easily in (111)Si, while it requires higher fluence to overcome unfavorable precursors orientation and propagate in (100)Si.

  10. A low energy beam transport system for proton beam

    SciTech Connect

    Yang, Y.; Zhang, Z. M.; Wu, Q.; Zhang, W. H.; Ma, H. Y.; Sun, L. T.; Zhang, X. Z.; Liu, Z. W.; He, Y.; Zhao, H. W.; Xie, D. Z.

    2013-03-15

    A low energy beam transport (LEBT) system has been built for a compact pulsed hadron source (CPHS) at Tsinghua University in China. The LEBT, consisting of two solenoids and three short-drift sections, transports a pulsed proton beam of 60 mA of energy of 50 keV to the entrance of a radio frequency quadrupole (RFQ). Measurement has shown a normalized RMS beam emittance less than 0.2 {pi} mm mrad at the end of the LEBT. Beam simulations were carried out to compare with the measurement and are in good agreement. Based on the successful CPHS LEBT development, a new LEBT for a China ADS projector has been designed. The features of the new design, including a beam chopper and beam simulations of the LEBT are presented and discussed along with CPHS LEBT development in this article.

  11. Enhancement of the maximum proton energy by funnel-geometry target in laser-plasma interactions

    NASA Astrophysics Data System (ADS)

    Yang, Peng; Fan, Dapeng; Li, Yuxiao

    2016-09-01

    Enhancement of the maximum proton energy using a funnel-geometry target is demonstrated through particle simulations of laser-plasma interactions. When an intense short-pulse laser illuminate a thin foil target, the foil electrons are pushed by the laser ponderomotive force, and then form an electron cloud at the target rear surface. The electron cloud generates a strong electrostatic field, which accelerates the protons to high energies. If there is a hole in the rear of target, the shape of the electron cloud and the distribution of the protons will be affected by the protuberant part of the hole. In this paper, a funnel-geometry target is proposed to improve the maximum proton energy. Using particle-in-cell 2-dimensional simulations, the transverse electric field generated by the side wall of four different holes are calculated, and protons inside holes are restricted to specific shapes by these field. In the funnel-geometry target, more protons are restricted near the center of the longitudinal accelerating electric field, thus protons experiencing longer accelerating time and distance in the sheath field compared with that in a traditional cylinder hole target. Accordingly, more and higher energy protons are produced from the funnel-geometry target. The maximum proton energy is improved by about 4 MeV compared with a traditional cylinder-shaped hole target. The funnel-geometry target serves as a new method to improve the maximum proton energy in laser-plasma interactions.

  12. Radiation damage in silicon exposed to high-energy protons

    SciTech Connect

    Davies, Gordon; Hayama, Shusaku; Murin, Leonid; Krause-Rehberg, Reinhard; Bondarenko, Vladimir; Sengupta, Asmita; Davia, Cinzia; Karpenko, Anna

    2006-04-15

    Photoluminescence, infrared absorption, positron annihilation, and deep-level transient spectroscopy (DLTS) have been used to investigate the radiation damage produced by 24 GeV/c protons in crystalline silicon. The irradiation doses and the concentrations of carbon and oxygen in the samples have been chosen to monitor the mobility of the damage products. Single vacancies (and self-interstitials) are introduced at the rate of {approx}1 cm{sup -1}, and divacancies at 0.5 cm{sup -1}. Stable di-interstitials are formed when two self-interstitials are displaced in one damage event, and they are mobile at room temperature. In the initial stages of annealing the evolution of the point defects can be understood mainly in terms of trapping at the impurities. However, the positron signal shows that about two orders of magnitude more vacancies are produced by the protons than are detected in the point defects. Damage clusters exist, and are largely removed by annealing at 700 to 800 K, when there is an associated loss of broad band emission between 850 and 1000 meV. The well-known W center is generated by restructuring within clusters, with a range of activation energies of about 1.3 to 1.6 eV, reflecting the disordered nature of the clusters. Comparison of the formation of the X centers in oxygenated and oxygen-lean samples suggests that the J defect may be interstitial related rather than vacancy related. To a large extent, the damage and annealing behavior may be factorized into point defects (monitored by sharp-line optical spectra and DLTS) and cluster defects (monitored by positron annihilation and broadband luminescence). Taking this view to the limit, the generation rates for the point defects are as predicted by simply taking the damage generated by the Coulomb interaction of the protons and Si nuclei.

  13. Energy Dependence of Moments of Net-Proton Multiplicity Distributions at RHIC

    NASA Astrophysics Data System (ADS)

    Adamczyk, L.; Adkins, J. K.; Agakishiev, G.; Aggarwal, M. M.; Ahammed, Z.; Alekseev, I.; Alford, J.; Anson, C. D.; Aparin, A.; Arkhipkin, D.; Aschenauer, E. C.; Averichev, G. S.; Balewski, J.; Banerjee, A.; Barnovska, Z.; Beavis, D. R.; Bellwied, R.; Bhasin, A.; Bhati, A. K.; Bhattarai, P.; Bichsel, H.; Bielcik, J.; Bielcikova, J.; Bland, L. C.; Bordyuzhin, I. G.; Borowski, W.; Bouchet, J.; Brandin, A. V.; Brovko, S. G.; Bültmann, S.; Bunzarov, I.; Burton, T. P.; Butterworth, J.; Caines, H.; Calderón de la Barca Sánchez, M.; Cebra, D.; Cendejas, R.; Cervantes, M. C.; Chaloupka, P.; Chang, Z.; Chattopadhyay, S.; Chen, H. F.; Chen, J. H.; Chen, L.; Cheng, J.; Cherney, M.; Chikanian, A.; Christie, W.; Chwastowski, J.; Codrington, M. J. M.; Corliss, R.; Cramer, J. G.; Crawford, H. J.; Cui, X.; Das, S.; Davila Leyva, A.; De Silva, L. C.; Debbe, R. R.; Dedovich, T. G.; Deng, J.; Derevschikov, A. A.; Derradi de Souza, R.; Dhamija, S.; di Ruzza, B.; Didenko, L.; Dilks, C.; Ding, F.; Djawotho, P.; Dong, X.; Drachenberg, J. L.; Draper, J. E.; Du, C. M.; Dunkelberger, L. E.; Dunlop, J. C.; Efimov, L. G.; Engelage, J.; Engle, K. S.; Eppley, G.; Eun, L.; Evdokimov, O.; Fatemi, R.; Fazio, S.; Fedorisin, J.; Filip, P.; Finch, E.; Fisyak, Y.; Flores, C. E.; Gagliardi, C. A.; Gangadharan, D. R.; Garand, D.; Geurts, F.; Gibson, A.; Girard, M.; Gliske, S.; Grosnick, D.; Guo, Y.; Gupta, A.; Gupta, S.; Guryn, W.; Haag, B.; Hajkova, O.; Hamed, A.; Han, L.-X.; Haque, R.; Harris, J. W.; Hays-Wehle, J. P.; Heppelmann, S.; Hirsch, A.; Hoffmann, G. W.; Hofman, D. J.; Horvat, S.; Huang, B.; Huang, H. Z.; Huck, P.; Humanic, T. J.; Igo, G.; Jacobs, W. W.; Jang, H.; Judd, E. G.; Kabana, S.; Kalinkin, D.; Kang, K.; Kauder, K.; Ke, H. W.; Keane, D.; Kechechyan, A.; Kesich, A.; Khan, Z. H.; Kikola, D. P.; Kisel, I.; Kisiel, A.; Koetke, D. D.; Kollegger, T.; Konzer, J.; Koralt, I.; Korsch, W.; Kotchenda, L.; Kravtsov, P.; Krueger, K.; Kulakov, I.; Kumar, L.; Kycia, R. A.; Lamont, M. A. C.; Landgraf, J. M.; Landry, K. D.; Lauret, J.; Lebedev, A.; Lednicky, R.; Lee, J. H.; Leight, W.; LeVine, M. J.; Li, C.; Li, W.; Li, X.; Li, X.; Li, Y.; Li, Z. M.; Lima, L. M.; Lisa, M. A.; Liu, F.; Ljubicic, T.; Llope, W. J.; Longacre, R. S.; Luo, X.; Ma, G. L.; Ma, Y. G.; Madagodagettige Don, D. M. M. D.; Mahapatra, D. P.; Majka, R.; Margetis, S.; Markert, C.; Masui, H.; Matis, H. S.; McDonald, D.; McShane, T. S.; Minaev, N. G.; Mioduszewski, S.; Mohanty, B.; Mondal, M. M.; Morozov, D. A.; Munhoz, M. G.; Mustafa, M. K.; Nandi, B. K.; Nasim, Md.; Nayak, T. K.; Nelson, J. M.; Nogach, L. V.; Noh, S. Y.; Novak, J.; Nurushev, S. B.; Odyniec, G.; Ogawa, A.; Oh, K.; Ohlson, A.; Okorokov, V.; Oldag, E. W.; Oliveira, R. A. N.; Pachr, M.; Page, B. S.; Pal, S. K.; Pan, Y. X.; Pandit, Y.; Panebratsev, Y.; Pawlak, T.; Pawlik, B.; Pei, H.; Perkins, C.; Peryt, W.; Peterson, A.; Pile, P.; Planinic, M.; Pluta, J.; Plyku, D.; Poljak, N.; Porter, J.; Poskanzer, A. M.; Pruthi, N. K.; Przybycien, M.; Pujahari, P. R.; Putschke, J.; Qiu, H.; Quintero, A.; Ramachandran, S.; Raniwala, R.; Raniwala, S.; Ray, R. L.; Riley, C. K.; Ritter, H. G.; Roberts, J. B.; Rogachevskiy, O. V.; Romero, J. L.; Ross, J. F.; Roy, A.; Ruan, L.; Rusnak, J.; Sahoo, N. R.; Sahu, P. K.; Sakrejda, I.; Salur, S.; Sandacz, A.; Sandweiss, J.; Sangaline, E.; Sarkar, A.; Schambach, J.; Scharenberg, R. P.; Schmah, A. M.; Schmidke, W. B.; Schmitz, N.; Seger, J.; Seyboth, P.; Shah, N.; Shahaliev, E.; Shanmuganathan, P. V.; Shao, M.; Sharma, B.; Shen, W. Q.; Shi, S. S.; Shou, Q. Y.; Sichtermann, E. P.; Singaraju, R. N.; Skoby, M. J.; Smirnov, D.; Smirnov, N.; Solanki, D.; Sorensen, P.; deSouza, U. G.; Spinka, H. M.; Srivastava, B.; Stanislaus, T. D. S.; Stevens, J. R.; Stock, R.; Strikhanov, M.; Stringfellow, B.; Suaide, A. A. P.; Sumbera, M.; Sun, X.; Sun, X. M.; Sun, Y.; Sun, Z.; Surrow, B.; Svirida, D. N.; Symons, T. J. M.; Szanto de Toledo, A.; Takahashi, J.; Tang, A. H.; Tang, Z.; Tarnowsky, T.; Thomas, J. H.; Timmins, A. R.; Tlusty, D.; Tokarev, M.; Trentalange, S.; Tribble, R. E.; Tribedy, P.; Trzeciak, B. A.; Tsai, O. D.; Turnau, J.; Ullrich, T.; Underwood, D. G.; Van Buren, G.; van Nieuwenhuizen, G.; Vanfossen, J. A.; Varma, R.; Vasconcelos, G. M. S.; Vasiliev, A. N.; Vertesi, R.; Videbæk, F.; Viyogi, Y. P.; Vokal, S.; Voloshin, S. A.; Vossen, A.; Wada, M.; Walker, M.; Wang, F.; Wang, G.; Wang, H.; Wang, J. S.; Wang, X. L.; Wang, Y.; Wang, Y.; Webb, G.; Webb, J. C.; Westfall, G. D.; Wieman, H.; Wissink, S. W.; Witt, R.; Wu, Y. F.; Xiao, Z.; Xie, W.; Xin, K.; Xu, H.; Xu, N.; Xu, Q. H.; Xu, Y.; Xu, Z.; Yan, W.; Yang, C.; Yang, Y.; Yang, Y.; Ye, Z.; Yepes, P.; Yi, L.; Yip, K.; Yoo, I.-K.; Zawisza, Y.; Zbroszczyk, H.; Zha, W.; Zhang, J. B.; Zhang, S.; Zhang, X. P.; Zhang, Y.; Zhang, Z. P.; Zhao, F.; Zhao, J.; Zhong, C.; Zhu, X.; Zhu, Y. H.; Zoulkarneeva, Y.; Zyzak, M.; STAR Collaboration

    2014-01-01

    We report the beam energy (√sNN =7.7-200 GeV) and collision centrality dependence of the mean (M), standard deviation (σ), skewness (S), and kurtosis (κ) of the net-proton multiplicity distributions in Au +Au collisions. The measurements are carried out by the STAR experiment at midrapidity (|y|<0.5) and within the transverse momentum range 0.4Energy Scan program at the Relativistic Heavy Ion Collider. These measurements are important for understanding the quantum chromodynamic phase diagram. The products of the moments, Sσ and κσ2, are sensitive to the correlation length of the hot and dense medium created in the collisions and are related to the ratios of baryon number susceptibilities of corresponding orders. The products of moments are found to have values significantly below the Skellam expectation and close to expectations based on independent proton and antiproton production. The measurements are compared to a transport model calculation to understand the effect of acceptance and baryon number conservation and also to a hadron resonance gas model.

  14. Energy dependence of moments of net-proton multiplicity distributions at RHIC.

    PubMed

    Adamczyk, L; Adkins, J K; Agakishiev, G; Aggarwal, M M; Ahammed, Z; Alekseev, I; Alford, J; Anson, C D; Aparin, A; Arkhipkin, D; Aschenauer, E C; Averichev, G S; Balewski, J; Banerjee, A; Barnovska, Z; Beavis, D R; Bellwied, R; Bhasin, A; Bhati, A K; Bhattarai, P; Bichsel, H; Bielcik, J; Bielcikova, J; Bland, L C; Bordyuzhin, I G; Borowski, W; Bouchet, J; Brandin, A V; Brovko, S G; Bültmann, S; Bunzarov, I; Burton, T P; Butterworth, J; Caines, H; Calderón de la Barca Sánchez, M; Cebra, D; Cendejas, R; Cervantes, M C; Chaloupka, P; Chang, Z; Chattopadhyay, S; Chen, H F; Chen, J H; Chen, L; Cheng, J; Cherney, M; Chikanian, A; Christie, W; Chwastowski, J; Codrington, M J M; Corliss, R; Cramer, J G; Crawford, H J; Cui, X; Das, S; Davila Leyva, A; De Silva, L C; Debbe, R R; Dedovich, T G; Deng, J; Derevschikov, A A; Derradi de Souza, R; Dhamija, S; di Ruzza, B; Didenko, L; Dilks, C; Ding, F; Djawotho, P; Dong, X; Drachenberg, J L; Draper, J E; Du, C M; Dunkelberger, L E; Dunlop, J C; Efimov, L G; Engelage, J; Engle, K S; Eppley, G; Eun, L; Evdokimov, O; Fatemi, R; Fazio, S; Fedorisin, J; Filip, P; Finch, E; Fisyak, Y; Flores, C E; Gagliardi, C A; Gangadharan, D R; Garand, D; Geurts, F; Gibson, A; Girard, M; Gliske, S; Grosnick, D; Guo, Y; Gupta, A; Gupta, S; Guryn, W; Haag, B; Hajkova, O; Hamed, A; Han, L-X; Haque, R; Harris, J W; Hays-Wehle, J P; Heppelmann, S; Hirsch, A; Hoffmann, G W; Hofman, D J; Horvat, S; Huang, B; Huang, H Z; Huck, P; Humanic, T J; Igo, G; Jacobs, W W; Jang, H; Judd, E G; Kabana, S; Kalinkin, D; Kang, K; Kauder, K; Ke, H W; Keane, D; Kechechyan, A; Kesich, A; Khan, Z H; Kikola, D P; Kisel, I; Kisiel, A; Koetke, D D; Kollegger, T; Konzer, J; Koralt, I; Korsch, W; Kotchenda, L; Kravtsov, P; Krueger, K; Kulakov, I; Kumar, L; Kycia, R A; Lamont, M A C; Landgraf, J M; Landry, K D; Lauret, J; Lebedev, A; Lednicky, R; Lee, J H; Leight, W; LeVine, M J; Li, C; Li, W; Li, X; Li, X; Li, Y; Li, Z M; Lima, L M; Lisa, M A; Liu, F; Ljubicic, T; Llope, W J; Longacre, R S; Luo, X; Ma, G L; Ma, Y G; Madagodagettige Don, D M M D; Mahapatra, D P; Majka, R; Margetis, S; Markert, C; Masui, H; Matis, H S; McDonald, D; McShane, T S; Minaev, N G; Mioduszewski, S; Mohanty, B; Mondal, M M; Morozov, D A; Munhoz, M G; Mustafa, M K; Nandi, B K; Nasim, Md; Nayak, T K; Nelson, J M; Nogach, L V; Noh, S Y; Novak, J; Nurushev, S B; Odyniec, G; Ogawa, A; Oh, K; Ohlson, A; Okorokov, V; Oldag, E W; Oliveira, R A N; Pachr, M; Page, B S; Pal, S K; Pan, Y X; Pandit, Y; Panebratsev, Y; Pawlak, T; Pawlik, B; Pei, H; Perkins, C; Peryt, W; Peterson, A; Pile, P; Planinic, M; Pluta, J; Plyku, D; Poljak, N; Porter, J; Poskanzer, A M; Pruthi, N K; Przybycien, M; Pujahari, P R; Putschke, J; Qiu, H; Quintero, A; Ramachandran, S; Raniwala, R; Raniwala, S; Ray, R L; Riley, C K; Ritter, H G; Roberts, J B; Rogachevskiy, O V; Romero, J L; Ross, J F; Roy, A; Ruan, L; Rusnak, J; Sahoo, N R; Sahu, P K; Sakrejda, I; Salur, S; Sandacz, A; Sandweiss, J; Sangaline, E; Sarkar, A; Schambach, J; Scharenberg, R P; Schmah, A M; Schmidke, W B; Schmitz, N; Seger, J; Seyboth, P; Shah, N; Shahaliev, E; Shanmuganathan, P V; Shao, M; Sharma, B; Shen, W Q; Shi, S S; Shou, Q Y; Sichtermann, E P; Singaraju, R N; Skoby, M J; Smirnov, D; Smirnov, N; Solanki, D; Sorensen, P; deSouza, U G; Spinka, H M; Srivastava, B; Stanislaus, T D S; Stevens, J R; Stock, R; Strikhanov, M; Stringfellow, B; Suaide, A A P; Sumbera, M; Sun, X; Sun, X M; Sun, Y; Sun, Z; Surrow, B; Svirida, D N; Symons, T J M; Szanto de Toledo, A; Takahashi, J; Tang, A H; Tang, Z; Tarnowsky, T; Thomas, J H; Timmins, A R; Tlusty, D; Tokarev, M; Trentalange, S; Tribble, R E; Tribedy, P; Trzeciak, B A; Tsai, O D; Turnau, J; Ullrich, T; Underwood, D G; Van Buren, G; van Nieuwenhuizen, G; Vanfossen, J A; Varma, R; Vasconcelos, G M S; Vasiliev, A N; Vertesi, R; Videbæk, F; Viyogi, Y P; Vokal, S; Voloshin, S A; Vossen, A; Wada, M; Walker, M; Wang, F; Wang, G; Wang, H; Wang, J S; Wang, X L; Wang, Y; Wang, Y; Webb, G; Webb, J C; Westfall, G D; Wieman, H; Wissink, S W; Witt, R; Wu, Y F; Xiao, Z; Xie, W; Xin, K; Xu, H; Xu, N; Xu, Q H; Xu, Y; Xu, Z; Yan, W; Yang, C; Yang, Y; Yang, Y; Ye, Z; Yepes, P; Yi, L; Yip, K; Yoo, I-K; Zawisza, Y; Zbroszczyk, H; Zha, W; Zhang, J B; Zhang, S; Zhang, X P; Zhang, Y; Zhang, Z P; Zhao, F; Zhao, J; Zhong, C; Zhu, X; Zhu, Y H; Zoulkarneeva, Y; Zyzak, M

    2014-01-24

    We report the beam energy (sqrt[sNN]=7.7-200  GeV) and collision centrality dependence of the mean (M), standard deviation (σ), skewness (S), and kurtosis (κ) of the net-proton multiplicity distributions in Au+Au collisions. The measurements are carried out by the STAR experiment at midrapidity (|y|<0.5) and within the transverse momentum range 0.4Energy Scan program at the Relativistic Heavy Ion Collider. These measurements are important for understanding the quantum chromodynamic phase diagram. The products of the moments, Sσ and κσ2, are sensitive to the correlation length of the hot and dense medium created in the collisions and are related to the ratios of baryon number susceptibilities of corresponding orders. The products of moments are found to have values significantly below the Skellam expectation and close to expectations based on independent proton and antiproton production. The measurements are compared to a transport model calculation to understand the effect of acceptance and baryon number conservation and also to a hadron resonance gas model. PMID:24484135

  15. Fundamentals of charged devices: Energy changes in a capacitor medium

    NASA Astrophysics Data System (ADS)

    Young, J. S.; Baudry, L.

    2013-03-01

    Capacitors and derivative devices continue to be as relevant as ever, both at the frontiers of scientific and technological research and in the development of commercial products. Central to such pursuits is the essential requirement that all aspects of the work done in charging or discharging capacitors are clearly understood. Surprisingly, there is a very significant disagreement among standard texts and journal publications regarding this topic. The present work elaborates a thorough analysis of energy changes in a capacitor medium in terms of thermodynamic work and its extension to the more general, electrostatic energy change. Our conclusions agree, for example, with those of Volker Heine, but not with texts by Pippard or Callen. We also note that electric and magnetic analogues are not equivalent.

  16. Compact superferric FFAG accelerators for medium energy hadron applications

    NASA Astrophysics Data System (ADS)

    Qin, B.; Mori, Y.

    2011-08-01

    Medium energy hadron beams are desirable in various applications such as accelerator-driven subcritical systems (ADSR), high intensity neutron sources and carbon therapy. Compactness and easy operation characters are important for this energy region, especially in the case of medical use purposes. This paper introduces a novel superferric scheme with scaling fixed-field alternating gradient (FFAG) accelerators, which can provide 400 MeV/u carbon ions for cancer therapy. By employing a maximum field of 5 T with a high field index, 8.5 m diameter with 85 cm radius excursion is achieved in a single FFAG ring. The lattice configuration and design of superferric magnet sectors with high permeability materials were described in detail. This scheme can also be extended to other hadron applications.

  17. Steps towards a Medium-Energy Gamma-ray Mission

    NASA Astrophysics Data System (ADS)

    McEnery, Julie

    We propose to develop, fabricate, and test a small-scale medium-energy (0.2 - 500 MeV) gamma-ray telescope, optimized for photon detection in both the Compton-scattering and pair-production regimes. The instrument will consist of a double-sided Si-strip tracking detector with energy deposition readout, a composite CdZnTe-strip (CZT) and CsI(Tl)-log calorimeter with high spatial and good energy resolution, and a highly efficient anti-coincidence detector (ACD). This instrument will be a prototype for a potential future MIDEX-scale mission (ComPair) designed to provide a more than order of magnitude increase in sensitivity to the MeV gamma-ray Universe compared to past missions. ComPair will provide a significant improvement in both angular and energy resolution over previous instruments operating in the 0.2-100 MeV range, offering a truly new window on this poorly explored energy range. In this proposal, the team proposes to develop and test the key detection elements for ComPair, integrate these elements in a prototype telescope, perform a series of beam tests to demonstrate the performance, and perform a balloon test flight to study the background rejection capability of the prototype instrument. As a result, we will establish the proof of concept for a Si-CZT Compton-Pair space telescope and elevate the TRL for the ComPair technology to 6-7.

  18. A prediction model for bipolar RAMs in a high energy ion/proton environment

    NASA Technical Reports Server (NTRS)

    Myers, D. K.; Price, W. E.; Nichols, D. K.

    1981-01-01

    A model has been developed which predicts the relative susceptibility of bipolar RAMs to heavy ion and proton upset. During the course of evaluating this model, physical and electrical variations were also evaluated indicating that the minimum internal signal level is the primary upset susceptibility indicator. Unfortunately, all of the physical and electrical variations expected during a normal product development cycle are in direct opposition to improved high-energy particle upset tolerance. Hence, a trade-off between highly susceptible, low power (medium speed) devices must be made against the less susceptible, higher power (high speed) equivalent device, taking into account the systems trade-off with respect to system power, software, error correction procedures and/or circuit redundancy.

  19. Quantifying Low Energy Proton Damage in Multijunction Solar Cells

    NASA Technical Reports Server (NTRS)

    Messenger, Scott R.; Burke, Edward A.; Walters, Robert J.; Warner, Jeffrey H.; Summers, Geoffrey P.; Lorentzen, Justin R.; Morton, Thomas L.; Taylor, Steven J.

    2007-01-01

    An analysis of the effects of low energy proton irradiation on the electrical performance of triple junction (3J) InGaP2/GaAs/Ge solar cells is presented. The Monte Carlo ion transport code (SRIM) is used to simulate the damage profile induced in a 3J solar cell under the conditions of typical ground testing and that of the space environment. The results are used to present a quantitative analysis of the defect, and hence damage, distribution induced in the cell active region by the different radiation conditions. The modelling results show that, in the space environment, the solar cell will experience a uniform damage distribution through the active region of the cell. Through an application of the displacement damage dose analysis methodology, the implications of this result on mission performance predictions are investigated.

  20. Note: A new angle-resolved proton energy spectrometer

    SciTech Connect

    Zheng, Y.; Su, L. N.; Liu, M.; Liu, B. C.; Shen, Z. W.; Fan, H. T.; Li, Y. T.; Chen, L. M.; Lu, X.; Ma, J. L.; Wang, W. M.; Wang, Z. H.; Wei, Z. Y.; Zhang, J.

    2013-09-15

    In typical laser-driven proton acceleration experiments Thomson parabola proton spectrometers are used to measure the proton spectra with very small acceptance angle in specific directions. Stacks composed of CR-39 nuclear track detectors, imaging plates, or radiochromic films are used to measure the angular distributions of the proton beams, respectively. In this paper, a new proton spectrometer, which can measure the spectra and angular distributions simultaneously, has been designed. Proton acceleration experiments performed on the Xtreme light III laser system demonstrates that the spectrometer can give angle-resolved spectra with a large acceptance angle. This will be conductive to revealing the acceleration mechanisms, optimization, and applications of laser-driven proton beams.

  1. High-energy proton imaging for biomedical applications

    DOE PAGES

    Prall, Matthias; Durante, Marco; Berger, Thomas; Przybyla, B.; Graeff, C.; Lang, Phillipp M.; LaTessa, Ciara; Shestov, Less; Simoniello, P.; Danly, Christopher R.; et al

    2016-06-10

    The charged particle community is looking for techniques exploiting proton interactions instead of X-ray absorption for creating images of human tissue. Due to multiple Coulomb scattering inside the measured object it has shown to be highly non-trivial to achieve sufficient spatial resolution. We present imaging of biological tissue with a proton microscope. This device relies on magnetic optics, distinguishing it from most published proton imaging methods. For these methods reducing the data acquisition time to a clinically acceptable level has turned out to be challenging. In a proton microscope, data acquisition and processing are much simpler. This device even allowsmore » imaging in real time. The primary medical application will be image guidance in proton radiosurgery. Proton images demonstrating the potential for this application are presented. As a result, tomographic reconstructions are included to raise awareness of the possibility of high-resolution proton tomography using magneto-optics.« less

  2. High-energy proton imaging for biomedical applications.

    PubMed

    Prall, M; Durante, M; Berger, T; Przybyla, B; Graeff, C; Lang, P M; LaTessa, C; Shestov, L; Simoniello, P; Danly, C; Mariam, F; Merrill, F; Nedrow, P; Wilde, C; Varentsov, D

    2016-01-01

    The charged particle community is looking for techniques exploiting proton interactions instead of X-ray absorption for creating images of human tissue. Due to multiple Coulomb scattering inside the measured object it has shown to be highly non-trivial to achieve sufficient spatial resolution. We present imaging of biological tissue with a proton microscope. This device relies on magnetic optics, distinguishing it from most published proton imaging methods. For these methods reducing the data acquisition time to a clinically acceptable level has turned out to be challenging. In a proton microscope, data acquisition and processing are much simpler. This device even allows imaging in real time. The primary medical application will be image guidance in proton radiosurgery. Proton images demonstrating the potential for this application are presented. Tomographic reconstructions are included to raise awareness of the possibility of high-resolution proton tomography using magneto-optics. PMID:27282667

  3. High-energy proton imaging for biomedical applications

    NASA Astrophysics Data System (ADS)

    Prall, M.; Durante, M.; Berger, T.; Przybyla, B.; Graeff, C.; Lang, P. M.; Latessa, C.; Shestov, L.; Simoniello, P.; Danly, C.; Mariam, F.; Merrill, F.; Nedrow, P.; Wilde, C.; Varentsov, D.

    2016-06-01

    The charged particle community is looking for techniques exploiting proton interactions instead of X-ray absorption for creating images of human tissue. Due to multiple Coulomb scattering inside the measured object it has shown to be highly non-trivial to achieve sufficient spatial resolution. We present imaging of biological tissue with a proton microscope. This device relies on magnetic optics, distinguishing it from most published proton imaging methods. For these methods reducing the data acquisition time to a clinically acceptable level has turned out to be challenging. In a proton microscope, data acquisition and processing are much simpler. This device even allows imaging in real time. The primary medical application will be image guidance in proton radiosurgery. Proton images demonstrating the potential for this application are presented. Tomographic reconstructions are included to raise awareness of the possibility of high-resolution proton tomography using magneto-optics.

  4. High-energy proton imaging for biomedical applications

    PubMed Central

    Prall, M.; Durante, M.; Berger, T.; Przybyla, B.; Graeff, C.; Lang, P. M.; LaTessa, C.; Shestov, L.; Simoniello, P.; Danly, C.; Mariam, F.; Merrill, F.; Nedrow, P.; Wilde, C.; Varentsov, D.

    2016-01-01

    The charged particle community is looking for techniques exploiting proton interactions instead of X-ray absorption for creating images of human tissue. Due to multiple Coulomb scattering inside the measured object it has shown to be highly non-trivial to achieve sufficient spatial resolution. We present imaging of biological tissue with a proton microscope. This device relies on magnetic optics, distinguishing it from most published proton imaging methods. For these methods reducing the data acquisition time to a clinically acceptable level has turned out to be challenging. In a proton microscope, data acquisition and processing are much simpler. This device even allows imaging in real time. The primary medical application will be image guidance in proton radiosurgery. Proton images demonstrating the potential for this application are presented. Tomographic reconstructions are included to raise awareness of the possibility of high-resolution proton tomography using magneto-optics. PMID:27282667

  5. Science Requirements and Conceptual Design for a Polarized Medium Energy Electron-Ion Collider at Jlab

    SciTech Connect

    Abeyratne, S; Ahmed, S; Barber, D; Bisognano, J; Bogacz, A; Castilla, A; Chevtsov, P; Corneliussen, S; Deconinck, W; Degtiarenko, P; Delayen, J; Derbenev, Ya; DeSilva, S; Douglas, D; Dudnikov, V; Ent, R; Erdelyi, B; Evtushenko, P; Fujii, Yu; Filatov, Yury; Gaskell, D; Geng, R; Guzey, V; Horn, T; Hutton, A; Hyde, C; Johnson, R; Kim, Y; Klein, F; Kondratenko, A; Kondratenko, M; Krafft, G; Li, R; Lin, F; Manikonda, S; Marhauser, F; McKeown, R; Morozov, V; Dadel-Turonski, P; Nissen, E; Ostroumov, P; Pivi, M; Pilat, F; Poelker, M; Prokudin, A; Rimmer, R; Satogata, T; Sayed, H; Spata, M; Sullivan, M; Tennant, C; Terzic, B; Tiefenback, M; Wang, M; Wang, S; Weiss, C; Yunn, B; Zhang, Y

    2012-08-01

    beginning, the design studies at Jefferson Lab have focused on achieving high collider performance, particularly ultrahigh luminosities up to 10{sup 34} cm{sup -2}s{sup -1} per detector with large acceptance, while maintaining high polarization for both the electron and light-ion beams. These are the two key performance requirements of a future electron-ion collider facility as articulated by the NSAC Long Range Plan. In MEIC, a new ion complex is designed specifically to deliver ion beams that match the high bunch repetition and highly polarized electron beam from CEBAF. During the last two years, both development of the science case and optimization of the machine design point toward a medium-energy electron-ion collider as the topmost goal for Jefferson Lab. The MEIC, with relatively compact collider rings, can deliver a luminosity above 10{sup 34} cm{sup -2}s{sup -1} at a center-of-mass energy up to 65 GeV. It offers an electron energy up to 11 GeV, a proton energy up to 100 GeV, and corresponding energies per nucleon for heavy ions with the same magnetic rigidity. This design choice balances the scope of the science program, collider capabilities, accelerator technology innovation, and total project cost. An energy upgrade could be implemented in the future by adding two large collider rings housed in another large tunnel to push the center-of-mass energy up to or exceeding 140 GeV. After careful consideration of an alternative electron energy recovery linac on ion storage ring approach, a ring-ring collider scenario at high bunch repetition frequency was found to offer fully competitive performance while eliminating the uncertainties of challenging R&D on ampere-class polarized electron sources and many-pass energy-recovery linacs (ERLs). The essential new elements of an MEIC facility at Jefferson Lab are an electron storage ring and an entirely new, modern ion acceleration and storage complex. For the high-current electron collider ring, the upgraded 12 GeV CEBAF SRF

  6. Jet energy measurement and its systematic uncertainty in proton-proton collisions at TeV with the ATLAS detector

    NASA Astrophysics Data System (ADS)

    Aad, G.; Abajyan, T.; Abbott, B.; Abdallah, J.; Abdel Khalek, S.; Abdinov, O.; Aben, R.; Abi, B.; Abolins, M.; AbouZeid, O. S.; Abramowicz, H.; Abreu, H.; Abulaiti, Y.; Acharya, B. S.; Adamczyk, L.; Adams, D. L.; Addy, T. N.; Adelman, J.; Adomeit, S.; Adye, T.; Aefsky, S.; Agatonovic-Jovin, T.; Aguilar-Saavedra, J. A.; Agustoni, M.; Ahlen, S. P.; Ahmad, A.; Ahmadov, F.; Aielli, G.; Åkesson, T. P. A.; Akimoto, G.; Akimov, A. V.; Alam, M. A.; Albert, J.; Albrand, S.; Alconada Verzini, M. J.; Aleksa, M.; Aleksandrov, I. N.; Alessandria, F.; Alexa, C.; Alexander, G.; Alexandre, G.; Alexopoulos, T.; Alhroob, M.; Aliev, M.; Alimonti, G.; Alio, L.; Alison, J.; Allbrooke, B. M. M.; Allison, L. J.; Allport, P. P.; Allwood-Spiers, S. E.; Almond, J.; Aloisio, A.; Alon, R.; Alonso, A.; Alonso, F.; Altheimer, A.; Alvarez Gonzalez, B.; Alviggi, M. G.; Amako, K.; Amaral Coutinho, Y.; Amelung, C.; Ammosov, V. V.; Amor Dos Santos, S. P.; Amorim, A.; Amoroso, S.; Amram, N.; Amundsen, G.; Anastopoulos, C.; Ancu, L. S.; Andari, N.; Andeen, T.; Anders, C. F.; Anders, G.; Anderson, K. J.; Andreazza, A.; Andrei, V.; Anduaga, X. S.; Angelidakis, S.; Anger, P.; Angerami, A.; Anghinolfi, F.; Anisenkov, A. V.; Anjos, N.; Annovi, A.; Antonaki, A.; Antonelli, M.; Antonov, A.; Antos, J.; Anulli, F.; Aoki, M.; Aperio Bella, L.; Apolle, R.; Arabidze, G.; Aracena, I.; Arai, Y.; Arce, A. T. H.; Arfaoui, S.; Arguin, J.-F.; Argyropoulos, S.; Arik, E.; Arik, M.; Armbruster, A. J.; Arnaez, O.; Arnal, V.; Arslan, O.; Artamonov, A.; Artoni, G.; Asai, S.; Asbah, N.; Ask, S.; Åsman, B.; Asquith, L.; Assamagan, K.; Astalos, R.; Astbury, A.; Atkinson, M.; Atlay, N. B.; Auerbach, B.; Auge, E.; Augsten, K.; Aurousseau, M.; Avolio, G.; Azuelos, G.; Azuma, Y.; Baak, M. A.; Bacci, C.; Bach, A. M.; Bachacou, H.; Bachas, K.; Backes, M.; Backhaus, M.; Backus Mayes, J.; Badescu, E.; Bagiacchi, P.; Bagnaia, P.; Bai, Y.; Bailey, D. C.; Bain, T.; Baines, J. T.; Baker, O. K.; Baker, S.; Balek, P.; Balli, F.; Banas, E.; Banerjee, Sw.; Banfi, D.; Bangert, A.; Bansal, V.; Bansil, H. S.; Barak, L.; Baranov, S. P.; Barber, T.; Barberio, E. L.; Barberis, D.; Barbero, M.; Barillari, T.; Barisonzi, M.; Barklow, T.; Barlow, N.; Barnett, B. M.; Barnett, R. M.; Baroncelli, A.; Barone, G.; Barr, A. J.; Barreiro, F.; Barreiro Guimarães da Costa, J.; Bartoldus, R.; Barton, A. E.; Bartos, P.; Bartsch, V.; Bassalat, A.; Basye, A.; Bates, R. L.; Batkova, L.; Batley, J. R.; Battistin, M.; Bauer, F.; Bawa, H. S.; Beau, T.; Beauchemin, P. H.; Beccherle, R.; Bechtle, P.; Beck, H. P.; Becker, K.; Becker, S.; Beckingham, M.; Beddall, A. J.; Beddall, A.; Bedikian, S.; Bednyakov, V. A.; Bee, C. P.; Beemster, L. J.; Beermann, T. A.; Begel, M.; Behr, K.; Belanger-Champagne, C.; Bell, P. J.; Bell, W. H.; Bella, G.; Bellagamba, L.; Bellerive, A.; Bellomo, M.; Belloni, A.; Beloborodova, O. L.; Belotskiy, K.; Beltramello, O.; Benary, O.; Benchekroun, D.; Bendtz, K.; Benekos, N.; Benhammou, Y.; Benhar Noccioli, E.; Benitez Garcia, J. A.; Benjamin, D. P.; Bensinger, J. R.; Benslama, K.; Bentvelsen, S.; Berge, D.; Bergeaas Kuutmann, E.; Berger, N.; Berghaus, F.; Berglund, E.; Beringer, J.; Bernard, C.; Bernat, P.; Bernhard, R.; Bernius, C.; Bernlochner, F. U.; Berry, T.; Berta, P.; Bertella, C.; Bertolucci, F.; Besana, M. I.; Besjes, G. J.; Bessidskaia, O.; Besson, N.; Bethke, S.; Bhimji, W.; Bianchi, R. M.; Bianchini, L.; Bianco, M.; Biebel, O.; Bieniek, S. P.; Bierwagen, K.; Biesiada, J.; Biglietti, M.; Bilbao De Mendizabal, J.; Bilokon, H.; Bindi, M.; Binet, S.; Bingul, A.; Bini, C.; Bittner, B.; Black, C. W.; Black, J. E.; Black, K. M.; Blackburn, D.; Blair, R. E.; Blanchard, J.-B.; Blazek, T.; Bloch, I.; Blocker, C.; Blocki, J.; Blum, W.; Blumenschein, U.; Bobbink, G. J.; Bobrovnikov, V. S.; Bocchetta, S. S.; Bocci, A.; Boddy, C. R.; Boehler, M.; Boek, J.; Boek, T. T.; Boelaert, N.; Bogaerts, J. A.; Bogdanchikov, A. G.; Bogouch, A.; Bohm, C.; Bohm, J.; Boisvert, V.; Bold, T.; Boldea, V.; Boldyrev, A. S.; Bolnet, N. M.; Bomben, M.; Bona, M.; Boonekamp, M.; Bordoni, S.; Borer, C.; Borisov, A.; Borissov, G.; Borri, M.; Borroni, S.; Bortfeldt, J.; Bortolotto, V.; Bos, K.; Boscherini, D.; Bosman, M.; Boterenbrood, H.; Bouchami, J.; Boudreau, J.; Bouhova-Thacker, E. V.; Boumediene, D.; Bourdarios, C.; Bousson, N.; Boutouil, S.; Boveia, A.; Boyd, J.; Boyko, I. R.; Bozovic-Jelisavcic, I.; Bracinik, J.; Branchini, P.; Brandt, A.; Brandt, G.; Brandt, O.; Bratzler, U.; Brau, B.; Brau, J. E.; Braun, H. M.; Brazzale, S. F.; Brelier, B.; Brendlinger, K.; Brenner, R.; Bressler, S.; Bristow, T. M.; Britton, D.; Brochu, F. M.; Brock, I.; Brock, R.; Broggi, F.; Bromberg, C.; Bronner, J.; Brooijmans, G.; Brooks, T.; Brooks, W. K.; Brosamer, J.; Brost, E.; Brown, G.; Brown, J.; Bruckman de Renstrom, P. A.; Bruncko, D.; Bruneliere, R.; Brunet, S.; Bruni, A.; Bruni, G.; Bruschi, M.; Bryngemark, L.; Buanes, T.; Buat, Q.; Bucci, F.; Buchholz, P.; Buckingham, R. M.; Buckley, A. G.; Buda, S. I.; Budagov, I. A.; Budick, B.; Buehrer, F.; Bugge, L.; Bugge, M. K.; Bulekov, O.; Bundock, A. C.; Bunse, M.; Burckhart, H.; Burdin, S.; Burgess, T.; Burghgrave, B.; Burke, S.; Burmeister, I.; Busato, E.; Büscher, V.; Bussey, P.; Buszello, C. P.; Butler, B.; Butler, J. M.; Butt, A. I.; Buttar, C. M.; Butterworth, J. M.; Buttinger, W.; Buzatu, A.; Byszewski, M.; Cabrera Urbán, S.; Caforio, D.; Cakir, O.; Calafiura, P.; Calderini, G.; Calfayan, P.; Calkins, R.; Caloba, L. P.; Caloi, R.; Calvet, D.; Calvet, S.; Camacho Toro, R.; Camarri, P.; Cameron, D.; Caminada, L. M.; Caminal Armadans, R.; Campana, S.; Campanelli, M.; Canale, V.; Canelli, F.; Canepa, A.; Cantero, J.; Cantrill, R.; Cao, T.; Capeans Garrido, M. D. M.; Caprini, I.; Caprini, M.; Capua, M.; Caputo, R.; Cardarelli, R.; Carli, T.; Carlino, G.; Carminati, L.; Caron, S.; Carquin, E.; Carrillo-Montoya, G. D.; Carter, A. A.; Carter, J. R.; Carvalho, J.; Casadei, D.; Casado, M. P.; Caso, C.; Castaneda-Miranda, E.; Castelli, A.; Castillo Gimenez, V.; Castro, N. F.; Catastini, P.; Catinaccio, A.; Catmore, J. R.; Cattai, A.; Cattani, G.; Caughron, S.; Cavaliere, V.; Cavalli, D.; Cavalli-Sforza, M.; Cavasinni, V.; Ceradini, F.; Cerio, B.; Cerny, K.; Cerqueira, A. S.; Cerri, A.; Cerrito, L.; Cerutti, F.; Cervelli, A.; Cetin, S. A.; Chafaq, A.; Chakraborty, D.; Chalupkova, I.; Chan, K.; Chang, P.; Chapleau, B.; Chapman, J. D.; Charfeddine, D.; Charlton, D. G.; Chavda, V.; Chavez Barajas, C. A.; Cheatham, S.; Chekanov, S.; Chekulaev, S. V.; Chelkov, G. A.; Chelstowska, M. A.; Chen, C.; Chen, H.; Chen, K.; Chen, L.; Chen, S.; Chen, X.; Chen, Y.; Cheng, Y.; Cheplakov, A.; Cherkaoui El Moursli, R.; Chernyatin, V.; Cheu, E.; Chevalier, L.; Chiarella, V.; Chiefari, G.; Childers, J. T.; Chilingarov, A.; Chiodini, G.; Chisholm, A. S.; Chislett, R. T.; Chitan, A.; Chizhov, M. V.; Chouridou, S.; Chow, B. K. B.; Christidi, I. A.; Chromek-Burckhart, D.; Chu, M. L.; Chudoba, J.; Ciapetti, G.; Ciftci, A. K.; Ciftci, R.; Cinca, D.; Cindro, V.; Ciocio, A.; Cirilli, M.; Cirkovic, P.; Citron, Z. H.; Citterio, M.; Ciubancan, M.; Clark, A.; Clark, P. J.; Clarke, R. N.; Cleland, W.; Clemens, J. C.; Clement, B.; Clement, C.; Coadou, Y.; Cobal, M.; Coccaro, A.; Cochran, J.; Coelli, S.; Coffey, L.; Cogan, J. G.; Coggeshall, J.; Colas, J.; Cole, B.; Cole, S.; Colijn, A. P.; Collins-Tooth, C.; Collot, J.; Colombo, T.; Colon, G.; Compostella, G.; Conde Muiño, P.; Coniavitis, E.; Conidi, M. C.; Connelly, I. A.; Consonni, S. M.; Consorti, V.; Constantinescu, S.; Conta, C.; Conti, G.; Conventi, F.; Cooke, M.; Cooper, B. D.; Cooper-Sarkar, A. M.; Cooper-Smith, N. J.; Copic, K.; Cornelissen, T.; Corradi, M.; Corriveau, F.; Corso-Radu, A.; Cortes-Gonzalez, A.; Cortiana, G.; Costa, G.; Costa, M. J.; Costanzo, D.; Côté, D.; Cottin, G.; Courneyea, L.; Cowan, G.; Cox, B. E.; Cranmer, K.; Cree, G.; Crépé-Renaudin, S.; Crescioli, F.; Crispin Ortuzar, M.; Cristinziani, M.; Crosetti, G.; Cuciuc, C.-M.; Cuenca Almenar, C.; Cuhadar Donszelmann, T.; Cummings, J.; Curatolo, M.; Cuthbert, C.; Czirr, H.; Czodrowski, P.; Czyczula, Z.; D'Auria, S.; D'Onofrio, M.; D'Orazio, A.; Da Cunha Sargedas De Sousa, M. J.; Da Via, C.; Dabrowski, W.; Dafinca, A.; Dai, T.; Dallaire, F.; Dallapiccola, C.; Dam, M.; Daniells, A. C.; Dano Hoffmann, M.; Dao, V.; Darbo, G.; Darlea, G. L.; Darmora, S.; Dassoulas, J. A.; Davey, W.; David, C.; Davidek, T.; Davies, E.; Davies, M.; Davignon, O.; Davison, A. R.; Davygora, Y.; Dawe, E.; Dawson, I.; Daya-Ishmukhametova, R. K.; De, K.; de Asmundis, R.; De Castro, S.; De Cecco, S.; de Graat, J.; De Groot, N.; de Jong, P.; De La Taille, C.; De la Torre, H.; De Lorenzi, F.; De Nooij, L.; De Pedis, D.; De Salvo, A.; De Sanctis, U.; De Santo, A.; De Vivie De Regie, J. B.; De Zorzi, G.; Dearnaley, W. J.; Debbe, R.; Debenedetti, C.; Dechenaux, B.; Dedovich, D. V.; Degenhardt, J.; Del Peso, J.; Del Prete, T.; Delemontex, T.; Deliot, F.; Deliyergiyev, M.; Dell'Acqua, A.; Dell'Asta, L.; Della Pietra, M.; della Volpe, D.; Delmastro, M.; Delsart, P. A.; Deluca, C.; Demers, S.; Demichev, M.; Demilly, A.; Demirkoz, B.; Denisov, S. P.; Derendarz, D.; Derkaoui, J. E.; Derue, F.; Dervan, P.; Desch, K.; Deviveiros, P. O.; Dewhurst, A.; DeWilde, B.; Dhaliwal, S.; Dhullipudi, R.; Di Ciaccio, A.; Di Ciaccio, L.; Di Domenico, A.; Di Donato, C.; Di Girolamo, A.; Di Girolamo, B.; Di Mattia, A.; Di Micco, B.; Di Nardo, R.; Di Simone, A.; Di Sipio, R.; Di Valentino, D.; Diaz, M. A.; Diehl, E. B.; Dietrich, J.; Dietzsch, T. A.; Diglio, S.; Dindar Yagci, K.; Dingfelder, J.; Dionisi, C.; Dita, P.; Dita, S.; Dittus, F.; Djama, F.; Djobava, T.; do Vale, M. A. B.; Do Valle Wemans, A.; Doan, T. K. O.; Dobos, D.; Dobson, E.; Dodd, J.; Doglioni, C.; Doherty, T.; Dohmae, T.; Dolejsi, J.; Dolezal, Z.; Dolgoshein, B. A.; Donadelli, M.; Donati, S.; Dondero, P.; Donini, J.; Dopke, J.; Doria, A.; Dos Anjos, A.; Dotti, A.; Dova, M. T.; Doyle, A. T.; Dris, M.; Dubbert, J.; Dube, S.; Dubreuil, E.; Duchovni, E.; Duckeck, G.; Ducu, O. A.; Duda, D.; Dudarev, A.; Dudziak, F.; Duflot, L.; Duguid, L.; Dührssen, M.; Dunford, M.; Duran Yildiz, H.; Düren, M.; Dwuznik, M.; Ebke, J.; Edson, W.; Edwards, C. A.; Edwards, N. C.; Ehrenfeld, W.; Eifert, T.; Eigen, G.; Einsweiler, K.; Eisenhandler, E.; Ekelof, T.; El Kacimi, M.; Ellert, M.; Elles, S.; Ellinghaus, F.; Ellis, K.; Ellis, N.; Elmsheuser, J.; Elsing, M.; Emeliyanov, D.; Enari, Y.; Endner, O. C.; Endo, M.; Engelmann, R.; Erdmann, J.; Ereditato, A.; Eriksson, D.; Ernis, G.; Ernst, J.; Ernst, M.; Ernwein, J.; Errede, D.; Errede, S.; Ertel, E.; Escalier, M.; Esch, H.; Escobar, C.; Espinal Curull, X.; Esposito, B.; Etienne, F.; Etienvre, A. I.; Etzion, E.; Evangelakou, D.; Evans, H.; Fabbri, L.; Facini, G.; Fakhrutdinov, R. M.; Falciano, S.; Fang, Y.; Fanti, M.; Farbin, A.; Farilla, A.; Farooque, T.; Farrell, S.; Farrington, S. M.; Farthouat, P.; Fassi, F.; Fassnacht, P.; Fassouliotis, D.; Fatholahzadeh, B.; Favareto, A.; Fayard, L.; Federic, P.; Fedin, O. L.; Fedorko, W.; Fehling-Kaschek, M.; Feligioni, L.; Feng, C.; Feng, E. J.; Feng, H.; Fenyuk, A. B.; Fernando, W.; Ferrag, S.; Ferrando, J.; Ferrara, V.; Ferrari, A.; Ferrari, P.; Ferrari, R.; Ferreira de Lima, D. E.; Ferrer, A.; Ferrere, D.; Ferretti, C.; Ferretto Parodi, A.; Fiascaris, M.; Fiedler, F.; Filipčič, A.; Filipuzzi, M.; Filthaut, F.; Fincke-Keeler, M.; Finelli, K. D.; Fiolhais, M. C. N.; Fiorini, L.; Firan, A.; Fischer, J.; Fisher, M. J.; Fitzgerald, E. A.; Flechl, M.; Fleck, I.; Fleischmann, P.; Fleischmann, S.; Fletcher, G. T.; Fletcher, G.; Flick, T.; Floderus, A.; Flores Castillo, L. R.; Florez Bustos, A. C.; Flowerdew, M. J.; Fonseca Martin, T.; Formica, A.; Forti, A.; Fortin, D.; Fournier, D.; Fox, H.; Francavilla, P.; Franchini, M.; Franchino, S.; Francis, D.; Franklin, M.; Franz, S.; Fraternali, M.; Fratina, S.; French, S. T.; Friedrich, C.; Friedrich, F.; Froidevaux, D.; Frost, J. A.; Fukunaga, C.; Fullana Torregrosa, E.; Fulsom, B. G.; Fuster, J.; Gabaldon, C.; Gabizon, O.; Gabrielli, A.; Gabrielli, A.; Gadatsch, S.; Gadfort, T.; Gadomski, S.; Gagliardi, G.; Gagnon, P.; Galea, C.; Galhardo, B.; Gallas, E. J.; Gallo, V.; Gallop, B. J.; Gallus, P.; Galster, G.; Gan, K. K.; Gandrajula, R. P.; Gao, J.; Gao, Y. S.; Garay Walls, F. M.; Garberson, F.; García, C.; García Navarro, J. E.; Garcia-Sciveres, M.; Gardner, R. W.; Garelli, N.; Garonne, V.; Gatti, C.; Gaudio, G.; Gaur, B.; Gauthier, L.; Gauzzi, P.; Gavrilenko, I. L.; Gay, C.; Gaycken, G.; Gazis, E. N.; Ge, P.; Gecse, Z.; Gee, C. N. P.; Geerts, D. A. A.; Geich-Gimbel, Ch.; Gellerstedt, K.; Gemme, C.; Gemmell, A.; Genest, M. H.; Gentile, S.; George, M.; George, S.; Gerbaudo, D.; Gershon, A.; Ghazlane, H.; Ghodbane, N.; Giacobbe, B.; Giagu, S.; Giangiobbe, V.; Giannetti, P.; Gianotti, F.; Gibbard, B.; Gibson, S. M.; Gilchriese, M.; Gillam, T. P. S.; Gillberg, D.; Gillman, A. R.; Gingrich, D. M.; Giokaris, N.; Giordani, M. P.; Giordano, R.; Giorgi, F. M.; Giovannini, P.; Giraud, P. F.; Giugni, D.; Giuliani, C.; Giunta, M.; Gjelsten, B. K.; Gkialas, I.; Gladilin, L. K.; Glasman, C.; Glatzer, J.; Glazov, A.; Glonti, G. L.; Goblirsch-Kolb, M.; Goddard, J. R.; Godfrey, J.; Godlewski, J.; Goeringer, C.; Goldfarb, S.; Golling, T.; Golubkov, D.; Gomes, A.; Gomez Fajardo, L. S.; Gonçalo, R.; Goncalves Pinto Firmino Da Costa, J.; Gonella, L.; González de la Hoz, S.; Gonzalez Parra, G.; Gonzalez Silva, M. L.; Gonzalez-Sevilla, S.; Goodson, J. J.; Goossens, L.; Gorbounov, P. A.; Gordon, H. A.; Gorelov, I.; Gorfine, G.; Gorini, B.; Gorini, E.; Gorišek, A.; Gornicki, E.; Goshaw, A. T.; Gössling, C.; Gostkin, M. I.; Gouighri, M.; Goujdami, D.; Goulette, M. P.; Goussiou, A. G.; Goy, C.; Gozpinar, S.; Grabas, H. M. X.; Graber, L.; Grabowska-Bold, I.; Grafström, P.; Grahn, K.-J.; Gramling, J.; Gramstad, E.; Grancagnolo, F.; Grancagnolo, S.; Grassi, V.; Gratchev, V.; Gray, H. M.; Gray, J. A.; Graziani, E.; Grebenyuk, O. G.; Greenwood, Z. D.; Gregersen, K.; Gregor, I. M.; Grenier, P.; Griffiths, J.; Grigalashvili, N.; Grillo, A. A.; Grimm, K.; Grinstein, S.; Gris, Ph.; Grishkevich, Y. V.; Grivaz, J.-F.; Grohs, J. P.; Grohsjean, A.; Gross, E.; Grosse-Knetter, J.; Grossi, G. C.; Groth-Jensen, J.; Grout, Z. J.; Grybel, K.; Guescini, F.; Guest, D.; Gueta, O.; Guicheney, C.; Guido, E.; Guillemin, T.; Guindon, S.; Gul, U.; Gumpert, C.; Gunther, J.; Guo, J.; Gupta, S.; Gutierrez, P.; Gutierrez Ortiz, N. G.; Gutschow, C.; Guttman, N.; Guyot, C.; Gwenlan, C.; Gwilliam, C. B.; Haas, A.; Haber, C.; Hadavand, H. K.; Haefner, P.; Hageboeck, S.; Hajduk, Z.; Hakobyan, H.; Haleem, M.; Hall, D.; Halladjian, G.; Hamacher, K.; Hamal, P.; Hamano, K.; Hamer, M.; Hamilton, A.; Hamilton, S.; Han, L.; Hanagaki, K.; Hanawa, K.; Hance, M.; Hanke, P.; Hansen, J. R.; Hansen, J. B.; Hansen, J. D.; Hansen, P. H.; Hansson, P.; Hara, K.; Hard, A. S.; Harenberg, T.; Harkusha, S.; Harper, D.; Harrington, R. D.; Harris, O. M.; Harrison, P. 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C.; Sansoni, A.; Santoni, C.; Santonico, R.; Santos, H.; Santoyo Castillo, I.; Sapp, K.; Sapronov, A.; Saraiva, J. G.; Sarkisyan-Grinbaum, E.; Sarrazin, B.; Sartisohn, G.; Sasaki, O.; Sasaki, Y.; Sasao, N.; Satsounkevitch, I.; Sauvage, G.; Sauvan, E.; Sauvan, J. B.; Savard, P.; Savinov, V.; Savu, D. O.; Sawyer, C.; Sawyer, L.; Saxon, D. H.; Saxon, J.; Sbarra, C.; Sbrizzi, A.; Scanlon, T.; Scannicchio, D. A.; Scarcella, M.; Schaarschmidt, J.; Schacht, P.; Schaefer, D.; Schaelicke, A.; Schaepe, S.; Schaetzel, S.; Schäfer, U.; Schaffer, A. C.; Schaile, D.; Schamberger, R. D.; Scharf, V.; Schegelsky, V. A.; Scheirich, D.; Schernau, M.; Scherzer, M. I.; Schiavi, C.; Schieck, J.; Schillo, C.; Schioppa, M.; Schlenker, S.; Schmidt, E.; Schmieden, K.; Schmitt, C.; Schmitt, C.; Schmitt, S.; Schneider, B.; Schnellbach, Y. J.; Schnoor, U.; Schoeffel, L.; Schoening, A.; Schoenrock, B. D.; Schorlemmer, A. L. S.; Schott, M.; Schouten, D.; Schovancova, J.; Schram, M.; Schramm, S.; Schreyer, M.; Schroeder, C.; Schroer, N.; Schuh, N.; Schultens, M. J.; Schultz-Coulon, H.-C.; Schulz, H.; Schumacher, M.; Schumm, B. A.; Schune, Ph.; Schwartzman, A.; Schwegler, Ph.; Schwemling, Ph.; Schwienhorst, R.; Schwindling, J.; Schwindt, T.; Schwoerer, M.; Sciacca, F. G.; Scifo, E.; Sciolla, G.; Scott, W. G.; Scutti, F.; Searcy, J.; Sedov, G.; Sedykh, E.; Seidel, S. C.; Seiden, A.; Seifert, F.; Seixas, J. M.; Sekhniaidze, G.; Sekula, S. J.; Selbach, K. E.; Seliverstov, D. M.; Sellers, G.; Seman, M.; Semprini-Cesari, N.; Serfon, C.; Serin, L.; Serkin, L.; Serre, T.; Seuster, R.; Severini, H.; Sforza, F.; Sfyrla, A.; Shabalina, E.; Shamim, M.; Shan, L. Y.; Shank, J. T.; Shao, Q. T.; Shapiro, M.; Shatalov, P. B.; Shaw, K.; Sherwood, P.; Shimizu, S.; Shimojima, M.; Shin, T.; Shiyakova, M.; Shmeleva, A.; Shochet, M. J.; Short, D.; Shrestha, S.; Shulga, E.; Shupe, M. A.; Shushkevich, S.; Sicho, P.; Sidorov, D.; Sidoti, A.; Siegert, F.; Sijacki, Dj.; Silbert, O.; Silva, J.; Silver, Y.; Silverstein, D.; Silverstein, S. B.; Simak, V.; Simard, O.; Simic, Lj.; Simion, S.; Simioni, E.; Simmons, B.; Simoniello, R.; Simonyan, M.; Sinervo, P.; Sinev, N. B.; Sipica, V.; Siragusa, G.; Sircar, A.; Sisakyan, A. N.; Sivoklokov, S. Yu.; Sjölin, J.; Sjursen, T. B.; Skinnari, L. A.; Skottowe, H. P.; Skovpen, K. Yu.; Skubic, P.; Slater, M.; Slavicek, T.; Sliwa, K.; Smakhtin, V.; Smart, B. H.; Smestad, L.; Smirnov, S. Yu.; Smirnov, Y.; Smirnova, L. N.; Smirnova, O.; Smith, K. M.; Smizanska, M.; Smolek, K.; Snesarev, A. A.; Snidero, G.; Snow, J.; Snyder, S.; Sobie, R.; Socher, F.; Sodomka, J.; Soffer, A.; Soh, D. A.; Solans, C. A.; Solar, M.; Solc, J.; Soldatov, E. Yu.; Soldevila, U.; Solfaroli Camillocci, E.; Solodkov, A. A.; Solovyanov, O. V.; Solovyev, V.; Soni, N.; Sood, A.; Sopko, V.; Sopko, B.; Sosebee, M.; Soualah, R.; Soueid, P.; Soukharev, A. M.; South, D.; Spagnolo, S.; Spanò, F.; Spearman, W. R.; Spighi, R.; Spigo, G.; Spousta, M.; Spreitzer, T.; Spurlock, B.; St. Denis, R. D.; Stahlman, J.; Stamen, R.; Stanecka, E.; Stanek, R. W.; Stanescu, C.; Stanescu-Bellu, M.; Stanitzki, M. M.; Stapnes, S.; Starchenko, E. A.; Stark, J.; Staroba, P.; Starovoitov, P.; Staszewski, R.; Stavina, P.; Steele, G.; Steinbach, P.; Steinberg, P.; Stekl, I.; Stelzer, B.; Stelzer, H. J.; Stelzer-Chilton, O.; Stenzel, H.; Stern, S.; Stewart, G. A.; Stillings, J. A.; Stockton, M. C.; Stoebe, M.; Stoerig, K.; Stoicea, G.; Stonjek, S.; Stradling, A. R.; Straessner, A.; Strandberg, J.; Strandberg, S.; Strandlie, A.; Strauss, E.; Strauss, M.; Strizenec, P.; Ströhmer, R.; Strom, D. M.; Stroynowski, R.; Stucci, S. A.; Stugu, B.; Stumer, I.; Stupak, J.; Sturm, P.; Styles, N. A.; Su, D.; Su, J.; Subramania, HS.; Subramaniam, R.; Succurro, A.; Sugaya, Y.; Suhr, C.; Suk, M.; Sulin, V. V.; Sultansoy, S.; Sumida, T.; Sun, X.; Sundermann, J. E.; Suruliz, K.; Susinno, G.; Sutton, M. R.; Suzuki, Y.; Svatos, M.; Swedish, S.; Swiatlowski, M.; Sykora, I.; Sykora, T.; Ta, D.; Tackmann, K.; Taenzer, J.; Taffard, A.; Tafirout, R.; Taiblum, N.; Takahashi, Y.; Takai, H.; Takashima, R.; Takeda, H.; Takeshita, T.; Takubo, Y.; Talby, M.; Talyshev, A. A.; Tam, J. Y. C.; Tamsett, M. C.; Tan, K. G.; Tanaka, J.; Tanaka, R.; Tanaka, S.; Tanaka, S.; Tanasijczuk, A. J.; Tani, K.; Tannoury, N.; Tapprogge, S.; Tarem, S.; Tarrade, F.; Tartarelli, G. F.; Tas, P.; Tasevsky, M.; Tashiro, T.; Tassi, E.; Tavares Delgado, A.; Tayalati, Y.; Taylor, C.; Taylor, F. E.; Taylor, G. N.; Taylor, W.; Teischinger, F. A.; Teixeira Dias Castanheira, M.; Teixeira-Dias, P.; Temming, K. K.; Ten Kate, H.; Teng, P. K.; Terada, S.; Terashi, K.; Terron, J.; Terzo, S.; Testa, M.; Teuscher, R. J.; Therhaag, J.; Theveneaux-Pelzer, T.; Thoma, S.; Thomas, J. P.; Thompson, E. N.; Thompson, P. D.; Thompson, P. D.; Thompson, A. S.; Thomsen, L. A.; Thomson, E.; Thomson, M.; Thong, W. M.; Thun, R. P.; Tian, F.; Tibbetts, M. J.; Tic, T.; Tikhomirov, V. O.; Tikhonov, Yu. A.; Timoshenko, S.; Tiouchichine, E.; Tipton, P.; Tisserant, S.; Todorov, T.; Todorova-Nova, S.; Toggerson, B.; Tojo, J.; Tokár, S.; Tokushuku, K.; Tollefson, K.; Tomlinson, L.; Tomoto, M.; Tompkins, L.; Toms, K.; Topilin, N. D.; Torrence, E.; Torres, H.; Torró Pastor, E.; Toth, J.; Touchard, F.; Tovey, D. R.; Tran, H. L.; Trefzger, T.; Tremblet, L.; Tricoli, A.; Trigger, I. M.; Trincaz-Duvoid, S.; Tripiana, M. F.; Triplett, N.; Trischuk, W.; Trocmé, B.; Troncon, C.; Trottier-McDonald, M.; Trovatelli, M.; True, P.; Trzebinski, M.; Trzupek, A.; Tsarouchas, C.; Tseng, J. C.-L.; Tsiareshka, P. V.; Tsionou, D.; Tsipolitis, G.; Tsirintanis, N.; Tsiskaridze, S.; Tsiskaridze, V.; Tskhadadze, E. G.; Tsukerman, I. I.; Tsulaia, V.; Tsung, J.-W.; Tsuno, S.; Tsybychev, D.; Tua, A.; Tudorache, A.; Tudorache, V.; Tuggle, J. M.; Tuna, A. N.; Tupputi, S. A.; Turchikhin, S.; Turecek, D.; Turk Cakir, I.; Turra, R.; Tuts, P. M.; Tykhonov, A.; Tylmad, M.; Tyndel, M.; Uchida, K.; Ueda, I.; Ueno, R.; Ughetto, M.; Ugland, M.; Uhlenbrock, M.; Ukegawa, F.; Unal, G.; Undrus, A.; Unel, G.; Ungaro, F. C.; Unno, Y.; Urbaniec, D.; Urquijo, P.; Usai, G.; Usanova, A.; Vacavant, L.; Vacek, V.; Vachon, B.; Valencic, N.; Valentinetti, S.; Valero, A.; Valery, L.; Valkar, S.; Valladolid Gallego, E.; Vallecorsa, S.; Valls Ferrer, J. A.; Van Berg, R.; Van Der Deijl, P. C.; van der Geer, R.; van der Graaf, H.; Van Der Leeuw, R.; van der Ster, D.; van Eldik, N.; van Gemmeren, P.; Van Nieuwkoop, J.; van Vulpen, I.; van Woerden, M. C.; Vanadia, M.; Vandelli, W.; Vaniachine, A.; Vankov, P.; Vannucci, F.; Vardanyan, G.; Vari, R.; Varnes, E. W.; Varol, T.; Varouchas, D.; Vartapetian, A.; Varvell, K. E.; Vassilakopoulos, V. I.; Vazeille, F.; Vazquez Schroeder, T.; Veatch, J.; Veloso, F.; Veneziano, S.; Ventura, A.; Ventura, D.; 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.; Vigne, R.; Villa, M.; Villaplana Perez, M.; Vilucchi, E.; Vincter, M. G.; Vinogradov, V. B.; Virzi, J.; Vitells, O.; Viti, M.; Vivarelli, I.; Vives Vaque, F.; Vlachos, S.; Vladoiu, D.; Vlasak, M.; Vogel, A.; Vokac, P.; Volpi, G.; Volpi, M.; Volpini, G.; von der Schmitt, H.; von Radziewski, H.; von Toerne, E.; Vorobel, V.; Vos, M.; Voss, R.; Vossebeld, J. H.; Vranjes, N.; Vranjes Milosavljevic, M.; Vrba, V.; Vreeswijk, M.; Vu Anh, T.; Vuillermet, R.; Vukotic, I.; Vykydal, Z.; Wagner, W.; Wagner, P.; Wahrmund, S.; Wakabayashi, J.; Walch, S.; Walder, J.; Walker, R.; Walkowiak, W.; Wall, R.; Waller, P.; Walsh, B.; Wang, C.; Wang, H.; Wang, H.; Wang, J.; Wang, J.; Wang, K.; Wang, R.; Wang, S. M.; Wang, T.; Wang, X.; Warburton, A.; Ward, C. P.; Wardrope, D. R.; Warsinsky, M.; Washbrook, A.; Wasicki, C.; Watanabe, I.; Watkins, P. M.; Watson, A. T.; Watson, I. J.; Watson, M. F.; Watts, G.; Watts, S.; Waugh, A. T.; Waugh, B. M.; Webb, S.; Weber, M. S.; Weber, S. W.; Webster, J. S.; Weidberg, A. R.; Weigell, P.; Weingarten, J.; Weiser, C.; Weits, H.; Wells, P. S.; Wenaus, T.; Wendland, D.; Weng, Z.; Wengler, T.; Wenig, S.; Wermes, N.; Werner, M.; Werner, P.; Wessels, M.; Wetter, J.; Whalen, K.; White, A.; White, M. J.; White, R.; White, S.; Whiteson, D.; Whittington, D.; Wicke, D.; Wickens, F. J.; Wiedenmann, W.; Wielers, M.; Wienemann, P.; Wiglesworth, C.; Wiik-Fuchs, L. A. M.; Wijeratne, P. A.; Wildauer, A.; Wildt, M. A.; Wilhelm, I.; Wilkens, H. G.; Will, J. Z.; Williams, H. H.; Williams, S.; Willis, W.; Willocq, S.; Wilson, J. A.; Wilson, A.; Wingerter-Seez, I.; Winkelmann, S.; Winklmeier, F.; Wittgen, M.; Wittig, T.; Wittkowski, J.; Wollstadt, S. J.; Wolter, M. W.; Wolters, H.; Wong, W. C.; Wosiek, B. K.; Wotschack, J.; Woudstra, M. J.; Wozniak, K. W.; Wraight, K.; Wright, M.; Wu, S. L.; Wu, X.; Wu, Y.; Wulf, E.; Wyatt, T. R.; Wynne, B. M.; Xella, S.; Xiao, M.; Xu, C.; Xu, D.; Xu, L.; Yabsley, B.; Yacoob, S.; Yamada, M.; Yamaguchi, H.; Yamaguchi, Y.; Yamamoto, A.; Yamamoto, K.; Yamamoto, S.; Yamamura, T.; Yamanaka, T.; Yamauchi, K.; Yamazaki, Y.; Yan, Z.; Yang, H.; Yang, H.; Yang, U. K.; Yang, Y.; Yanush, S.; Yao, L.; Yasu, Y.; Yatsenko, E.; Yau Wong, K. H.; Ye, J.; Ye, S.; Yen, A. L.; Yildirim, E.; Yilmaz, M.; Yoosoofmiya, R.; Yorita, K.; Yoshida, R.; Yoshihara, K.; Young, C.; Young, C. J. S.; Youssef, S.; Yu, D. R.; Yu, J.; Yu, J.; Yuan, L.; Yurkewicz, A.; Zabinski, B.; Zaidan, R.; Zaitsev, A. M.; Zaman, A.; Zambito, S.; Zanello, L.; Zanzi, D.; Zaytsev, A.; Zeitnitz, C.; Zeman, M.; Zemla, A.; Zengel, K.; Zenin, O.; Ženiš, T.; Zerwas, D.; Zevi della Porta, G.; Zhang, D.; Zhang, H.; Zhang, J.; Zhang, L.; Zhang, X.; Zhang, Z.; Zhao, Z.; Zhemchugov, A.; Zhong, J.; Zhou, B.; Zhou, L.; Zhou, N.; Zhu, C. G.; Zhu, H.; Zhu, J.; Zhu, Y.; Zhuang, X.; Zibell, A.; Zieminska, D.; Zimine, N. I.; Zimmermann, C.; Zimmermann, R.; Zimmermann, S.; Zimmermann, S.; Zinonos, Z.; Ziolkowski, M.; Zitoun, R.; Zobernig, G.; Zoccoli, A.; zur Nedden, M.; Zurzolo, G.; Zutshi, V.; Zwalinski, L.

    2015-01-01

    The jet energy scale (JES) and its systematic uncertainty are determined for jets measured with the ATLAS detector using proton-proton collision data with a centre-of-mass energy of TeV corresponding to an integrated luminosity of . Jets are reconstructed from energy deposits forming topological clusters of calorimeter cells using the anti- algorithm with distance parameters or , and are calibrated using MC simulations. A residual JES correction is applied to account for differences between data and MC simulations. This correction and its systematic uncertainty are estimated using a combination of in situ techniques exploiting the transverse momentum balance between a jet and a reference object such as a photon or a boson, for and pseudorapidities . The effect of multiple proton-proton interactions is corrected for, and an uncertainty is evaluated using in situ techniques. The smallest JES uncertainty of less than 1 % is found in the central calorimeter region () for jets with . For central jets at lower , the uncertainty is about 3 %. A consistent JES estimate is found using measurements of the calorimeter response of single hadrons in proton-proton collisions and test-beam data, which also provide the estimate for TeV. The calibration of forward jets is derived from dijet balance measurements. The resulting uncertainty reaches its largest value of 6 % for low- jets at . Additional JES uncertainties due to specific event topologies, such as close-by jets or selections of event samples with an enhanced content of jets originating from light quarks or gluons, are also discussed. The magnitude of these uncertainties depends on the event sample used in a given physics analysis, but typically amounts to 0.5-3 %.

  7. Self-energy shift of the energy levels of atomic hydrogen in photonic crystal medium

    NASA Astrophysics Data System (ADS)

    Gainutdinov, R. Kh; Khamadeev, M. A.; Steryakov, O. V.; Ziyatdinova, K. A.; Salakhov, M. Kh

    2016-05-01

    Corrections to the average kinetic energy of atomic electrons caused by the change in electron mass in the photonic crystal medium are investigated. Corresponding shift of energy levels of atoms placed in a photonic crystal is shown to be of order of the ordinary Lamb shift.

  8. Voyager 1 in the Local Interstellar Medium: Cosmic-ray Energy Density and Ionization Rate

    NASA Astrophysics Data System (ADS)

    Cummings, A. C.; Stone, E. C.; Heikkila, B. C.; Lal, N.; Webber, W. R.; Johannesson, G.; Moskalenko, I.; Orlando, E.; Porter, T.

    2015-12-01

    We present the energy spectra of cosmic ay nuclei and electrons in the local interstellar medium (LISM) from the Cosmic Ray Subsystem on Voyager 1 (V1). We use four models of the local interstellar spectra of nuclei and one of electrons that are constrained by the observations to compute the energy density and ionization rate of atomic H in the LISM above 3 MeV for electrons and protons and above 3 MeV/nuc for nuclei with Z > 1. We find that the total cosmic-ray energy density is in the range 0.82-0.97 eV/cm3, which includes a contribution of 0.023 eV/cm3 from electrons. We find the cosmic-ray ionization rate of atomic H to be in the range 1.45-1.58 x 10-17 s-1, which is a factor of more than 10 below the cosmic-ray ionization rate in diffuse interstellar clouds based on astrochemistry methods. We discuss possible reasons for this difference. Voyager data analysis is supported by NASA Grant NNN12AA012. GALPROP development is supported by NASA Grants NNX13AC47G and NNX10AE78G.

  9. Influence of osmolality of the medium on photosynthetic electron transport, proton fluxes and photophosphorylation in isolated thylakoids.

    PubMed

    Pan, R S; Sauna, Z; Dilley, R A; Sitaramam, V

    1995-02-01

    The high osmotic potential inhibition of photosynthetic electron transport was determined to be related to membrane compaction rather than to an effect of primary thylakoid volume changes. Osmotic inhibition of proton fluxes and phosphorylation were entirely due to osmotic inhibition of electron transport. The ATPase activity, the nature of coupling and the rate constant of proton efflux were not influenced by osmotic pressure, while the rate constant and the extent of proton influx were inhibited by osmotic pressure.

  10. Nuclear structure and reaction studies at medium energies

    SciTech Connect

    Hoffmann, G.W.; Ray, R.L.

    1990-10-01

    This document constitutes the (1988--1991) technical progress report for the ongoing medium energy physics research program supported by the US Department of Energy through special Research Grant FG05-88ER40444. The experiments discussed are conducted at the Los Alamos National Laboratory's (LANL) Clinton P. Anderson Meson Physics Facility (LAMPF), the Alternating Gradient Synchrotron (AGS) facility of the Brookhaven National Laboratory (BNL), and at the Fermi National Accelerator Laboratory (FNAL). The overall motivation for the work discussed in this document is driven by three main objectives: (1) provide hadron-nucleon and hadron-nucleus scattering data which serve to facilitate the study of effective two-body interactions, test (and possibly determine) nuclear structure, and help study reaction mechanisms and dynamics;(2) provide unique, first-of-a-kind exploratory'' hadron-nucleus scattering data in the hope that such data will lead to discovery of new phenomena and new physics; and (3) perform precision tests of fundamental interactions, such as rare decay searches, whose observation would imply fundamental new physics.

  11. Impact of high energy high intensity proton beams on targets: Case studies for Super Proton Synchrotron and Large Hadron Collider

    NASA Astrophysics Data System (ADS)

    Tahir, N. A.; Sancho, J. Blanco; Shutov, A.; Schmidt, R.; Piriz, A. R.

    2012-05-01

    The Large Hadron Collider (LHC) is designed to collide two proton beams with unprecedented particle energy of 7 TeV. Each beam comprises 2808 bunches and the separation between two neighboring bunches is 25 ns. The energy stored in each beam is 362 MJ, sufficient to melt 500 kg copper. Safety of operation is very important when working with such powerful beams. An accidental release of even a very small fraction of the beam energy can result in severe damage to the equipment. The machine protection system is essential to handle all types of possible accidental hazards; however, it is important to know about possible consequences of failures. One of the critical failure scenarios is when the entire beam is lost at a single point. In this paper we present detailed numerical simulations of the full impact of one LHC beam on a cylindrical solid carbon target. First, the energy deposition by the protons is calculated with the FLUKA code and this energy deposition is used in the BIG2 code to study the corresponding thermodynamic and the hydrodynamic response of the target that leads to a reduction in the density. The modified density distribution is used in FLUKA to calculate new energy loss distribution and the two codes are thus run iteratively. A suitable iteration step is considered to be the time interval during which the target density along the axis decreases by 15%-20%. Our simulations suggest that the full LHC proton beam penetrates up to 25 m in solid carbon whereas the range of the shower from a single proton in solid carbon is just about 3 m (hydrodynamic tunneling effect). It is planned to perform experiments at the experimental facility HiRadMat (High Radiation Materials) at CERN using the proton beam from the Super Proton Synchrotron (SPS), to compare experimental results with the theoretical predictions. Therefore simulations of the response of a solid copper cylindrical target hit by the SPS beam were performed. The particle energy in the SPS beam is 440

  12. Internal spin structure of the proton from high energy polarized e-p scattering

    SciTech Connect

    Hughes, V.W.; Baum, G.; Bergstroem, M.R.

    1981-02-01

    A review is given of experimental knowledge of the spin dependent structure functions of the proton, which is based on inclusive high energy scattering of longitudinal polarized electrons by longitudinally polarized protons in both the deep inelastic and resonance regions, and includes preliminary results from our most recent SLAC experiment. Implications for scaling, sum rules, models of proton structure, and the hyperfine structure interval in hydrogen are given. Possible future directions of research are indicated.

  13. Neutrons in proton pencil beam scanning: parameterization of energy, quality factors and RBE

    NASA Astrophysics Data System (ADS)

    Schneider, Uwe; Hälg, Roger A.; Baiocco, Giorgio; Lomax, Tony

    2016-08-01

    The biological effectiveness of neutrons produced during proton therapy in inducing cancer is unknown, but potentially large. In particular, since neutron biological effectiveness is energy dependent, it is necessary to estimate, besides the dose, also the energy spectra, in order to obtain quantities which could be a measure of the biological effectiveness and test current models and new approaches against epidemiological studies on cancer induction after proton therapy. For patients treated with proton pencil beam scanning, this work aims to predict the spatially localized neutron energies, the effective quality factor, the weighting factor according to ICRP, and two RBE values, the first obtained from the saturation corrected dose mean lineal energy and the second from DSB cluster induction. A proton pencil beam was Monte Carlo simulated using GEANT. Based on the simulated neutron spectra for three different proton beam energies a parameterization of energy, quality factors and RBE was calculated. The pencil beam algorithm used for treatment planning at PSI has been extended using the developed parameterizations in order to calculate the spatially localized neutron energy, quality factors and RBE for each treated patient. The parameterization represents the simple quantification of neutron energy in two energy bins and the quality factors and RBE with a satisfying precision up to 85 cm away from the proton pencil beam when compared to the results based on 3D Monte Carlo simulations. The root mean square error of the energy estimate between Monte Carlo simulation based results and the parameterization is 3.9%. For the quality factors and RBE estimates it is smaller than 0.9%. The model was successfully integrated into the PSI treatment planning system. It was found that the parameterizations for neutron energy, quality factors and RBE were independent of proton energy in the investigated energy range of interest for proton therapy. The pencil beam algorithm has

  14. Neutrons in proton pencil beam scanning: parameterization of energy, quality factors and RBE.

    PubMed

    Schneider, Uwe; Hälg, Roger A; Baiocco, Giorgio; Lomax, Tony

    2016-08-21

    The biological effectiveness of neutrons produced during proton therapy in inducing cancer is unknown, but potentially large. In particular, since neutron biological effectiveness is energy dependent, it is necessary to estimate, besides the dose, also the energy spectra, in order to obtain quantities which could be a measure of the biological effectiveness and test current models and new approaches against epidemiological studies on cancer induction after proton therapy. For patients treated with proton pencil beam scanning, this work aims to predict the spatially localized neutron energies, the effective quality factor, the weighting factor according to ICRP, and two RBE values, the first obtained from the saturation corrected dose mean lineal energy and the second from DSB cluster induction. A proton pencil beam was Monte Carlo simulated using GEANT. Based on the simulated neutron spectra for three different proton beam energies a parameterization of energy, quality factors and RBE was calculated. The pencil beam algorithm used for treatment planning at PSI has been extended using the developed parameterizations in order to calculate the spatially localized neutron energy, quality factors and RBE for each treated patient. The parameterization represents the simple quantification of neutron energy in two energy bins and the quality factors and RBE with a satisfying precision up to 85 cm away from the proton pencil beam when compared to the results based on 3D Monte Carlo simulations. The root mean square error of the energy estimate between Monte Carlo simulation based results and the parameterization is 3.9%. For the quality factors and RBE estimates it is smaller than 0.9%. The model was successfully integrated into the PSI treatment planning system. It was found that the parameterizations for neutron energy, quality factors and RBE were independent of proton energy in the investigated energy range of interest for proton therapy. The pencil beam algorithm has

  15. Neutrons in proton pencil beam scanning: parameterization of energy, quality factors and RBE.

    PubMed

    Schneider, Uwe; Hälg, Roger A; Baiocco, Giorgio; Lomax, Tony

    2016-08-21

    The biological effectiveness of neutrons produced during proton therapy in inducing cancer is unknown, but potentially large. In particular, since neutron biological effectiveness is energy dependent, it is necessary to estimate, besides the dose, also the energy spectra, in order to obtain quantities which could be a measure of the biological effectiveness and test current models and new approaches against epidemiological studies on cancer induction after proton therapy. For patients treated with proton pencil beam scanning, this work aims to predict the spatially localized neutron energies, the effective quality factor, the weighting factor according to ICRP, and two RBE values, the first obtained from the saturation corrected dose mean lineal energy and the second from DSB cluster induction. A proton pencil beam was Monte Carlo simulated using GEANT. Based on the simulated neutron spectra for three different proton beam energies a parameterization of energy, quality factors and RBE was calculated. The pencil beam algorithm used for treatment planning at PSI has been extended using the developed parameterizations in order to calculate the spatially localized neutron energy, quality factors and RBE for each treated patient. The parameterization represents the simple quantification of neutron energy in two energy bins and the quality factors and RBE with a satisfying precision up to 85 cm away from the proton pencil beam when compared to the results based on 3D Monte Carlo simulations. The root mean square error of the energy estimate between Monte Carlo simulation based results and the parameterization is 3.9%. For the quality factors and RBE estimates it is smaller than 0.9%. The model was successfully integrated into the PSI treatment planning system. It was found that the parameterizations for neutron energy, quality factors and RBE were independent of proton energy in the investigated energy range of interest for proton therapy. The pencil beam algorithm has

  16. Energy loss distributions of relativistic protons axially channeled in a bent silicon crystal

    NASA Astrophysics Data System (ADS)

    Stojanov, Nace; Petrović, Srdjan; Nešković, Nebojša

    2013-05-01

    A detailed study of the energy loss distributions of the relativistic protons axially channeled in the bent < 100 > Si crystals is presented in this work. The bending angle was varied from 0 to 20 μrad, while the crystal thickness was equal to 1 mm. The proton energy was chosen to be 7 TeV in accordance with the Large Hadron Collider (LHC) project, at the European Organization for Nuclear Research (CERN), in Geneva, Switzerland. The energy loss distributions of the channeled protons were generated using the numerical solution of the proton equations of motion in the transverse plane and the computer simulation method. An accurate energy loss model was used, which takes into account the trajectory dependence of the energy loss of protons during their motion through the crystal channels. Further, the dispersion of the proton's scattering angle caused by its collisions with the electrons of the crystal and the divergence of the proton beam were taken into account. The calculated dependence of the number of dechanneled protons on the bending angle was excellently fitted by the Gompertz type dechanneling function.

  17. Measurements of the proton-air cross section with high energy cosmic ray experiments

    NASA Astrophysics Data System (ADS)

    Abbasi, Rasha

    2016-07-01

    Detecting Ultra High Energy Cosmic Rays (UHECRs) enables us to measure the proton-air inelastic cross section σinel p-air at energies that we are unable to access with particle accelerators. The proton-proton cross section σp-p is subsequently inferred from the proton-air cross section at these energies. UHECR experiments have been reportingon the proton-air inelastic cross section starting with the Fly's Eye in 1984 at √s =30 TeV and ending with the most recent result of the Telescope Array experiment at √s = 95 TeV in 2015. In this proceeding, I will summarize the most recent experimental results on the σinel p-air measurements from the UHECR experiments.

  18. Optimization of the {sup 7}Li(p,n) proton beam energy for BNCT applications

    SciTech Connect

    Bleuel, D.L.; Donahue, R.J.

    1996-02-01

    The reaction {sup 7}Li(p,n){sup 7} Be has been proposed as an accelerator-based source of neutrons for Boron Neutron Capture Therapy (BNCT). This reaction has a large steep resonance for proton energies of about 2.3 MeV which ends at about 2.5 MeV. It has generally been accepted that one should use 2.5 MeV protons to get the highest yield of neutrons for BNCT. This paper suggests that for BNCT the optimum proton energy may be about 2.3 MeV and that a proton energy of about 2.2 MeV will provide the same useful neutron fluence outside a thinner moderator as the neutron fluence from a 2.5 MeV proton beam with a thicker moderator.

  19. Enhancement of proton energy by polarization switch in laser acceleration of multi-ion foils

    SciTech Connect

    Liu, Tung-Chang; Shao, Xi; Liu, Chuan-Sheng; Eliasson, Bengt; Wang, Jyhpyng; Chen, Shih-Hung

    2013-10-15

    We present a scheme to significantly increase the energy of quasi-monoenergetic protons accelerated by a laser beam without increasing the input power. This improvement is accomplished by first irradiating the foil several wave periods with circular polarization and then switching the laser to linear polarization. The polarization switch increases the electron temperature and thereby moves more electrons ahead of the proton layer, resulting in a space charge electric field pushing the protons forwards. The scaling of the proton energy evolution with respect to the switching time is studied, and an optimal switching time is obtained. The proton energy for the case with optimal switching time can reach about 80 MeV with an input laser power of 70 TW, an improvement of more than 30% compared to the case without polarization switch.

  20. Selective 4e-/4H+ O2 reduction by an iron(tetraferrocenyl)porphyrin complex: from proton transfer followed by electron transfer in organic solvent to proton coupled electron transfer in aqueous medium.

    PubMed

    Mittra, Kaustuv; Chatterjee, Sudipta; Samanta, Subhra; Dey, Abhishek

    2013-12-16

    An iron porphyrin catalyst bearing four ferrocenes and a hydrogen bonding distal pocket is found to catalyze 4e(-)/4H(+) oxygen reduction reaction (ORR) in organic solvent under homogeneous conditions in the presence of 2-3 equiv of Trifluoromethanesulphonic acid. Absorption spectroscopy, electron paramagnetic resonance (EPR), and resonance Raman data along with H2O2 assay indicate that one out of the four electrons necessary to reduce O2 to H2O is donated by the ferrous porphyrin while three are donated by the distal ferrocene residues. The same catalyst shows 4e(-)/4H(+) reduction of O2 in an aqueous medium, under heterogeneous conditions, over a wide range of pH. Both the selectivity and the rate of ORR are found to be pH independent in an aqueous medium. The ORR proceeds via a proton transfer followed by electron transfer (PET) step in an organic medium and while a 2e(-)/1H(+) proton coupled electron transfer (PCET) step determines the electrochemical potential of ORR in an aqueous medium.

  1. Fusion Energy and Stopping Power in a Degenerate DT Pellet Driven by a Laser-Accelerated Proton Beam

    NASA Astrophysics Data System (ADS)

    Mehrangiz, M.; Ghasemizad, A.; Jafari, S.; Khanbabaei, B.

    2016-06-01

    In this paper, we have improved the fast ignition scheme in order to have more authority needed for high-energy-gain. Due to the more penetrability and energy deposition of the particle beams in fusion targets, we employ a laser-to-ion converter foil as a scheme for generating energetic ion beams to ignite the fusion fuel. We find the favorable intensity and wavelength of incident laser by evaluating the laser-proton conversion gain. By calculating the source-target distance, proton beam power and energy are estimated. Our analysis is generalized to the plasma degeneracy effects which can increase the fusion gain several orders of magnitude by decreasing the ion-electron collisions in the plasma. It is found that the wavelength of 0.53 μm and the intensity of about 1020 W/cm2, by saving about 10% conversion coefficient, are the suitable measured values for converting a laser into protons. Besides, stopping power and fusion burn calculations have been done in degenerate and non-degenerate plasma mediums. The results indicate that in the presence of degeneracy, the rate of fusion enhances. Supported by the Research Council of University of Guilan

  2. Proton calibration of low energy neutron detectors containing (6)LiF

    NASA Technical Reports Server (NTRS)

    Benton, E. V.; Frank, A. L.

    1995-01-01

    The purpose of the present calibrations is to measure the proton response of the detectors with accelerated beams having energies within the region of maximum intensities in the trapped proton spectrum encountered in near-Earth orbit. This response is compared with the responses of the spaceflight detectors when related to proton exposures. All of the spaceflight neutron measurements have been accompanied by TLD absorbed doses measurements in close proximity within the spacecraft. For purposes of comparison, the spaceflight TLD doses are assumed to be proton doses.

  3. Pion- and proton-nucleus interactions at intermediate energy

    SciTech Connect

    Dehnhard, D.

    1992-02-01

    {pi}-meson and proton beams from the Los Alamos Meson Physics Facility (LAMPF) and the Indiana University Cyclotron Facility (IUCF) were used in scattering and reaction experiments on atomic nuclei. The experimental data allow tests of models of the reaction mechanism and of nuclear structure. For example, the asymmetries observed in a pion scattering experiment on polarized {sup 13}C nuclei were found to contain unique information on the isoscalar spin density. However, further experiments on polarized nuclei of simpler structure are needed to provide the data for a thorough analysis of the reaction mechanism. For this reason a pion scattering experiment on a polarized {sup 3}He target is planned and a high-resolution study on {sup 6}Li({pi},{pi}{prime}) will be done. An analysis of {pi}-triton coincidence events from the {sup 4}He({pi},{pi}{prime}t)p reaction yielded evidence for direct triton knock-out from {sup 4}He. This work will be continued at higher incident pion energies. Additional work on the {sup 4}He(p,n) reaction at IUCF is planned to determine the isovector strength in mass-4 nuclei and the level parameters of {sup 4}Li.

  4. Monte carlo computation of the energy deposited by protons in water, bone and adipose

    NASA Astrophysics Data System (ADS)

    Küçer, Rahmi; Küçer, Nermin; Türemen, Görkem

    2013-02-01

    Protons are most suitable for treating deeply-seated tumors due to their unique depth dose distribution. The maximum dose of protons is a pronounced peak, called the Bragg peak, with zero dose behind the peak. The objective of radiation therapy with protons is to deliver the dose to the target volume by using this type of distribution. This is achieved with a finite number of Bragg peaks at the depth of the target volume. The location of the peak in terms of depth depends on the energy of the protons. Simulations are used to determine the depth dose distribution of proton beams passing through tissue, so it is important that experimental data agree with the simulation data. In this study, we used the FLUKA computer code to determine the correct position of the Bragg peak for proton beams passing through water, bone and adipose, and the results were compared with experimental data.

  5. Validating the predicted lateral straggling of MeV-energy proton beams.

    SciTech Connect

    Felter, Thomas E.; Antolak, Arlyn J.; Bench, Graham

    2004-02-01

    Proton imaging is a potential nondestructive method for characterizing NIF (National Ignition Facility) targets in two- and three-dimensions with micron-scale spatial resolution. The main limitation for high resolution imaging with proton beams, especially for thick samples, is the positional blurring of the proton beam, known as 'lateral straggling'. Accurate prediction of the amount of lateral straggling and, consequently, the achievable spatial resolution in pertinent NIF target material combinations and geometries requires validated proton transport models. We present results of Monte Carlo simulations of MeV-energy proton transport through thin ({approx}1 micron thick) metal foils. The calculated residual proton distributions are compared to recent lateral straggling measurements obtained at the LLNL 4-MV Pelletron accelerator.

  6. Pion- and proton-nucleus interactions at intermediate energy

    SciTech Connect

    Dehnhard, D.

    1992-12-01

    We report on scattering and reaction experiments on light nuclei using the [pi]-meson and proton beams from the Los Alamos Meson Physics Facility (LAMPF) and the Indiana University Cyclotron Facility (IUCF). Differential cross sections, cross section asymmetries, and angular correlation functions have been measured in order to test models of the reaction mechanism and of nuclear structure. At LAMPF we have measured asymmetries for pion scattering from polarized [sup 13]C which are uniquely sensitive to the isoscalar spin density. In order to determine details of the reaction mechanism, we have obtained approval for a scattering experiment on polarized [sup 3]He for which the nuclear structure is very well known. We have completed data taking for two studies of elastic scattering of [pi][sup +] from [sup 6]Li and [sup l3]C. The detailed differential cross sections from these experiments will be used to constrain theoretical analyses of previous polarization experiments done at the Pierre-Scherrer-Institute (PSI) and at LAMPF. We have analyzed [pi]-triton coincidence events from the [sup 4]He([pi],[pi][prime] t)p reaction and have found evidence for direct triton knockout from [sup 4]He. We have extended these angular correlation measurements to higher energies and to [sup 2]H and [sup 3]He targets. At IUCF we have performed the first [sup 4]He(p,n) experiment at intermediate energies, T[sub p] = 100, 147, and 200 MeV, in a search for previously reported narrow states in [sup 4]Li of widths of [approx] 1 MeV. Within the statistics of the data we have found no evidence for such narrow structures.

  7. CMOS Active Pixel Sensors as energy-range detectors for proton Computed Tomography

    NASA Astrophysics Data System (ADS)

    Esposito, M.; Anaxagoras, T.; Evans, P. M.; Green, S.; Manolopoulos, S.; Nieto-Camero, J.; Parker, D. J.; Poludniowski, G.; Price, T.; Waltham, C.; Allinson, N. M.

    2015-06-01

    Since the first proof of concept in the early 70s, a number of technologies has been proposed to perform proton CT (pCT), as a means of mapping tissue stopping power for accurate treatment planning in proton therapy. Previous prototypes of energy-range detectors for pCT have been mainly based on the use of scintillator-based calorimeters, to measure proton residual energy after passing through the patient. However, such an approach is limited by the need for only a single proton passing through the energy-range detector in a read-out cycle. A novel approach to this problem could be the use of pixelated detectors, where the independent read-out of each pixel allows to measure simultaneously the residual energy of a number of protons in the same read-out cycle, facilitating a faster and more efficient pCT scan. This paper investigates the suitability of CMOS Active Pixel Sensors (APSs) to track individual protons as they go through a number of CMOS layers, forming an energy-range telescope. Measurements performed at the iThemba Laboratories will be presented and analysed in terms of correlation, to confirm capability of proton tracking for CMOS APSs.

  8. The Quest for Spinning Glue in High-Energy Polarized Proton-Proton Collisions at RHIC

    SciTech Connect

    Surrow, Bernd

    2007-10-26

    The STAR experiment at the Relativistic Heavy-Ion Collider (RHIC) at Brookhaven National Laboratory (BNL) is carrying out a spin physics program colliding transverse or longitudinal polarized proton beams at {radical}(s) = 200-500 GeV to gain a deeper insight into the spin structure and dynamics of the proton. These studies provide fundamental tests of Quantum Chromodynamics (QCD).One of the main objectives of the STAR spin physics program is the determination of the polarized gluon distribution function through a measurement of the longitudinal double-spin asymmetry, A{sub LL}, for various processes. Recent results will be shown on the measurement of A{sub LL} for inclusive jet production, neutral pion production and charged pion production at {radical}(s) = 200 GeV.

  9. Car-Parrinello Molecular Dynamics Simulations of Infrared Spectra of Crystalline Vitamin C with Analysis of Double Minimum Proton Potentials for Medium-Strong Hydrogen Bonds.

    PubMed

    Brela, Mateusz Z; Wójcik, Marek J; Boczar, Marek; Witek, Łukasz; Yasuda, Mitsuru; Ozaki, Yukihiro

    2015-06-25

    We studied proton dynamics of a hydrogen bonds of the crystalline l-ascorbic acid. Our approach was based on the Car-Parrinello molecular dynamics. The focal point of our study was simulation of the infrared spectra of l-ascorbic acid associated with the O-H stretching modes that are very sensitive to the strength of hydrogen bonding. In the l-ascorbic acid there are four kinds of hydrogen bonds. We calculated their spectra by using anharmonic approximation and the time course of the dipole moment function as obtained from the Car-Parrinello simulation. The quantization of the nuclear motion of the protons was made to perform detailed analysis of strength and properties of hydrogen bonds. We presented double minimum proton potentials with small value of barriers for medium-strong hydrogen bonds. We have also shown the difference character of medium-strong hydrogen bonds compared to weaker hydrogen bonds in the l-ascorbic acid. PMID:26028251

  10. LDEF (Flight), M0002-01 : Trapped-Proton Energy Spectrum Determination, Tray G12

    NASA Technical Reports Server (NTRS)

    1990-01-01

    The flight photograph was taken from the Orbiter aft flight deck during the LDEF retrieval prior to berthing the LDEF in the Orbiter cargo bay. The Trapped Proton Energy Spectrum Determination Experiment is one of four experiments located in a three (3) inch deep LDEF end center tray. Additional Trapped Proton Energy Experi ments are located in peripheral LDEF integrated experiment tray in the D03 and D09 tray loca tions. The Trapped Proton Energy experiment, located in the upper left quadrant of the integrated tray, appears to be intact with with no visible damage. A brown discoloration is visible on the Trapped Proton Energy experiment detector housings and along the upper surfaces of the experiment sup port structure. The discoloration around the outer edges of the experiment mounting plate appears to be a much lighter tan color. The sub-experiments are intact and secure with no visible dam age.

  11. A program in medium energy nuclear physics. Progress report, January 1, 1992--March 31, 1995

    SciTech Connect

    Berman, B.L.; Dhuga, K.S.

    1995-10-01

    This progress report and continuation proposal summarizes our achievements for the period from July 1, 1994 to September 30, 1995 and requests continued funding for our program in experimental medium-energy nuclear physics. The focus of our program remains the understanding of the short-range part of the strong interaction in the nuclear medium. In the past year we have focused our attention ever more sharply on experiments with real tagged photons, and we have successfully defended two new experimental proposals: Photofission of Actinide and Preactinide Nuclei at SAL and Photoproduction of the {rho} Meson from the Proton with Linearly Polarized Photons at CEBAF. (We are co-spokespersons on two previously approved Hall-B experiments at CEBAF, Photoreactions on {sup 3}He and Photoabsorption and Photofission of Nuclei.) As part of the team that is instrumenting the Photon Tagger for Hall B; we report excellent progress on the focal-plane detector array that is being built at our Nuclear Detector Laboratory, as well as progress on our plans for instrumentation of a tagged polarized-photon beam using coherent bremsstrahlung. Also, we shall soon receive a large computer system (from the SSC) which will form the basis for our new Data Analysis Center, which, like the Nuclear Detector Laboratory, will be operated under the auspices of The George Washington University Center for Nuclear Studies. Finally, during the past year we have published six more papers on the results of our measurements of pion scattering at LAMPF and of electron scattering at NIKHEF and Bates, and we can report that nearly all of the remaining papers documenting this long series of measurements are in the pipeline.

  12. Development of a medium-energy superconducting heavy-ion linac.

    SciTech Connect

    Ostroumov, P. N.; Physics

    2002-03-01

    The Rare Isotope Accelerator (RIA) facility project includes a cw 1.4 GeV driver linac and a 100 MV postaccelerator both based on superconducting (SC) cavities operating at frequencies from 48 to 805 MHz. In these linacs more than 99% of the total voltage is provided by SC cavities. An initial acceleration is provided by room temperature radio frequency quadrupoles. The driver linac is designed for acceleration of any ion species, from protons up to 900 MeV to uranium up to 400 MeV/u. The novel feature of the driver linac is an acceleration of multiple charge-state heavy-ion beams in order to achieve 400 kW beam power. This paper presents design features of a medium-energy SC heavy-ion linac taking the RIA driver linac as an example. The dynamics of single and multiple charge-state beams are detailed, including the effects of possible errors in rf field parameters and misalignments of transverse focusing elements. The important design considerations of such linac are presented. Several new conceptual solutions in beam dynamics in SC accelerating structures for heavy-ion applications are discussed.

  13. Effect of the orbital debris environment on the high-energy Van Allen proton belt

    NASA Technical Reports Server (NTRS)

    Konradi, Andrei

    1988-01-01

    The lifetimes of high-energy (greater than 55 MeV) protons in the Van Allen radiation belt are calculated, assuming that in time the protons will collide with and be absorbed by particulate orbiting material. The calculations are based on the NASA/DoD Civil Needs Database for orbital debris (Gaines, 1966) and moderate assumptions of future space traffic. It is found that the lifetimes of high-energy protons below 1500 km will decrease, leading to a noticeable redution in their fluxes.

  14. Energy dependence of the characteristic decay time of proton fluxes in solar cosmic ray events

    NASA Astrophysics Data System (ADS)

    Daibog, E. I.; Logachev, Yu. I.; Kecskemety, K.

    2008-02-01

    Energetic solar proton events within the energy interval 1-48 MeV at the stage of their decay are considered over the period of 1974-2001. The dependence of the characteristic decay time on the proton energy in the assumed power-law representation τ( E) = E - n is analyzed for the events with an exponential decay form. The dependence of n on the heliolongitude of the flare (the particles source on the Sun) is studied.

  15. Effect of the orbital debris environment on the high-energy van allen proton belt.

    PubMed

    Konradi, A

    1988-12-01

    Orbital debris in the near-Earth environment has reached a number density sufficient for a significant collisional interaction with some of the long-lived high-energy protons in the radiation belt. As a result of a continuing buildup of a shell of man-made debris, the lifetimes of high-energy protons whose trajectories remain below 1500 kilometers will decrease to the point where in the next decades we can expect a noticeable reduction in their fluxes.

  16. Modeling of exclusive parton distributions and long-range rapidity correlations in proton-proton collisions at the LHC energies

    SciTech Connect

    Kovalenko, V. N.

    2013-10-15

    The soft part of proton-proton interaction is considered within a phenomenological model that involves the formation of color strings. Under the assumption that an elementary collision is associated with the interaction of two color dipoles, the total inelastic cross section and the multiplicity of charged particles are estimated in order to fix model parameters. Particular attention is given to modeling of exclusive parton distributions with allowance for the energy-conservation law and for fixing the center of mass, which are necessary for describing correlations. An algorithm that describes the fusion of strings in the transverse plane and which takes into account their finite rapidity width is developed. The influence of string-fusion effects on long-range correlations is found within this mechanism.

  17. New insights gained on mechanisms of low-energy proton-induced SEUs by minimizing energy straggle

    SciTech Connect

    Dodds, Nathaniel Anson; Dodd, Paul E.; Shaneyfelt, Marty R.; Sexton, Frederick W.; Martinez, Marino J.; Black, Jeffrey D.; Marshall, P. W.; Reed, R. A.; McCurdy, M. W.; Weller, R. A.; Pellish, J. A.; Rodbell, K. P.; Gordon, M. S.

    2015-12-01

    In this study, we present low-energy proton single-event upset (SEU) data on a 65 nm SOI SRAM whose substrate has been completely removed. Since the protons only had to penetrate a very thin buried oxide layer, these measurements were affected by far less energy loss, energy straggle, flux attrition, and angular scattering than previous datasets. The minimization of these common sources of experimental interference allows more direct interpretation of the data and deeper insight into SEU mechanisms. The results show a strong angular dependence, demonstrate that energy straggle, flux attrition, and angular scattering affect the measured SEU cross sections, and prove that proton direct ionization is the dominant mechanism for low-energy proton-induced SEUs in these circuits.

  18. New insights gained on mechanisms of low-energy proton-induced SEUs by minimizing energy straggle

    DOE PAGES

    Dodds, Nathaniel Anson; Dodd, Paul E.; Shaneyfelt, Marty R.; Sexton, Frederick W.; Martinez, Marino J.; Black, Jeffrey D.; Marshall, P. W.; Reed, R. A.; McCurdy, M. W.; Weller, R. A.; et al

    2015-12-01

    In this study, we present low-energy proton single-event upset (SEU) data on a 65 nm SOI SRAM whose substrate has been completely removed. Since the protons only had to penetrate a very thin buried oxide layer, these measurements were affected by far less energy loss, energy straggle, flux attrition, and angular scattering than previous datasets. The minimization of these common sources of experimental interference allows more direct interpretation of the data and deeper insight into SEU mechanisms. The results show a strong angular dependence, demonstrate that energy straggle, flux attrition, and angular scattering affect the measured SEU cross sections, andmore » prove that proton direct ionization is the dominant mechanism for low-energy proton-induced SEUs in these circuits.« less

  19. Theoretical studies in medium-energy nuclear and hadronic physics

    SciTech Connect

    Horowitz, C.J.; Macfarlane, M.H.; Matsui, Tetsuo; Serot, B.D.

    1991-12-03

    In the period covered by this report (April 1, 1991 to March 31, 1992), work focused on six main areas: (1) Relativistic Theories of Nuclear Structure and Saturation, (2) Relativistic Descriptions of Proton-Nucleus and Electron-Nucleus Scattering, (3) Nonrelativistic Theory of Nucleon-Nucleus Reactions, (4) Relativistic Many-Body Theory at Finite Temperature and Density, (5) Neutrino Interactions in Dense Matter, (6) Quark Models of Nuclear and Quark Matter.

  20. Stoichiometric relationship between energy-dependent proton ejection and electron transport in mitochondria.

    PubMed

    Brand, M D; Reynafarje, B; Lehninger, A L

    1976-02-01

    The number of protons ejected during electron transport per pair of electrons per energy-conserving site (the H+/site ratio) was measured in rat liver mitochondria by three different methods under conditions in which transmembrane movements of endogenous phosphate were minized or eliminated. (1) In the Ca2+ pulse method, between 3.5 and 4.0 molecules of 3-hydroxybutyrate and 1.75 to 2.0 Ca2+ ions were accumulated per 2 e- per site during Ca2+ induced electron transport in the presence of rotenone, when measured under conditions in which movements of endogenous phosphate were negligible. Since entry of 3-hydroxybutyrate requires its protonation to the free acid these data correspond to an H+/site ratio of 3.5-4.0 (2) In the oxygen pulse method addition of known amounts of oxygen to anaerobic mitochondria in the presence of substrate yielded H+/site ratios of 3.0 when phosphate transport was eliminated by addition of N-ethylmaleimide or by anaerobic washing to remove endogenous phosphate. In the absence of such measures the observed H+/site ratio was 2.0. (3) In the reductant pulse method measurement of the initial steady rates of H+ ejection and oxygen consumption by mitochondria in an aerobic medium after addition of substrate gave H+/site near 4.0 in the presence of N-ethylmaleimide; in the absence of the inhibitor the observed ratio was only 2.0. These and other experiments reported indicate that the values of 2.0 earlier obtained for the H+/site ratio by Mitchell and Moyle [Biochem J. (1967) 105, 1147-1162] and others were underestimates due to the unrecognized masking of H+ ejection by movements of endogenous phosphate. The results presented here show that the H+/site ratio of mitochondrial electron transport is at least 3.0 and may be as high as 4.0.

  1. Gamma-ray astronomy in the medium energy (10-50 MeV) range

    NASA Technical Reports Server (NTRS)

    Kniffen, D. A.; Bertsch, D. L.; Morris, D. J.; Palmeira, R. A. R.; Rao, K. R.

    1977-01-01

    To observe the medium energy component of the intense galactic center gamma-ray emission, two balloon flights of a medium energy gamma-ray spark chamber telescope were flown in Brazil in 1975. The results indicate the emission is higher than previously thought and above the predictions of a theoretical model proposed.

  2. Mass prediction of proton-rich nuclides with the Coulomb displacement energies in the relativistic point-coupling model

    NASA Astrophysics Data System (ADS)

    Sun, BaoHua; Zhao, PengWei; Meng, Jie

    2011-02-01

    The masses, one- and two-proton separation energies of proton-rich nuclei with Z = 20-55, are computed using the measured masses of mirror neutron-rich nuclei and the Coulomb displacement energies calculated from the relativistic point-coupling model. The implications for the proton drip lines, candidates for two-proton emitters, as well as the impact on the astrophysical rp-process are discussed.

  3. Spin-spin correlations in proton-proton collisions at high energy and threshold enhancements

    SciTech Connect

    de Teramond, G.F.

    1988-05-01

    The striking effects in the spin structure observed in elastic proton collisions and the Nuclear Transparency phenomenon recently discovered at BNL are described in terms of heavy quark threshold enhancements. The deviations from scaling laws and the broadening of the angular distributions at resonance are also consistent with the introduction of new degrees of freedom in the pp system. This implies new s-channel physics. Predictions are given for the spin effects in pp collisions near 18.5 GeV/c at large p/sub T//sup 2/ where new measurements are planned. 9 refs., 4 figs.

  4. Relations Between Microwave Bursts and Near-Earth High-Energy Proton Enhancements and Their Origin

    NASA Astrophysics Data System (ADS)

    Grechnev, V. V.; Kiselev, V. I.; Meshalkina, N. S.; Chertok, I. M.

    2015-10-01

    We further study the relations between parameters of bursts at 35 GHz recorded with the Nobeyama Radio Polarimeters during 25 years and solar proton events (Grechnev et al. in Publ. Astron. Soc. Japan 65, S4, 2013a). Here we address the relations between the microwave fluences at 35 GHz and near-Earth proton fluences above 100 MeV to find information on their sources and evaluate their diagnostic potential. The correlation between the microwave and proton fluences is pronouncedly higher than between their peak fluxes. This probably reflects a dependence of the total number of protons on the duration of the acceleration process. In events with strong flares, the correlation coefficients of high-energy proton fluences with microwave and soft X-ray fluences are higher than those with the speeds of coronal mass ejections. The results indicate a statistically larger contribution of flare processes to high-energy proton fluxes. Acceleration by shock waves seems to be less important at high energies in events associated with strong flares, although its contribution is probable and possibly prevails in weaker events. The probability of a detectable proton enhancement was found to directly depend on the peak flux, duration, and fluence of the 35 GHz burst, while the role of the Big Flare Syndrome might have been overestimated previously. Empirical diagnostic relations are proposed.

  5. Shortening Delivery Times of Intensity Modulated Proton Therapy by Reducing Proton Energy Layers During Treatment Plan Optimization

    SciTech Connect

    Water, Steven van de; Kooy, Hanne M.; Heijmen, Ben J.M.; Hoogeman, Mischa S.

    2015-06-01

    Purpose: To shorten delivery times of intensity modulated proton therapy by reducing the number of energy layers in the treatment plan. Methods and Materials: We have developed an energy layer reduction method, which was implemented into our in-house-developed multicriteria treatment planning system “Erasmus-iCycle.” The method consisted of 2 components: (1) minimizing the logarithm of the total spot weight per energy layer; and (2) iteratively excluding low-weighted energy layers. The method was benchmarked by comparing a robust “time-efficient plan” (with energy layer reduction) with a robust “standard clinical plan” (without energy layer reduction) for 5 oropharyngeal cases and 5 prostate cases. Both plans of each patient had equal robust plan quality, because the worst-case dose parameters of the standard clinical plan were used as dose constraints for the time-efficient plan. Worst-case robust optimization was performed, accounting for setup errors of 3 mm and range errors of 3% + 1 mm. We evaluated the number of energy layers and the expected delivery time per fraction, assuming 30 seconds per beam direction, 10 ms per spot, and 400 Giga-protons per minute. The energy switching time was varied from 0.1 to 5 seconds. Results: The number of energy layers was on average reduced by 45% (range, 30%-56%) for the oropharyngeal cases and by 28% (range, 25%-32%) for the prostate cases. When assuming 1, 2, or 5 seconds energy switching time, the average delivery time was shortened from 3.9 to 3.0 minutes (25%), 6.0 to 4.2 minutes (32%), or 12.3 to 7.7 minutes (38%) for the oropharyngeal cases, and from 3.4 to 2.9 minutes (16%), 5.2 to 4.2 minutes (20%), or 10.6 to 8.0 minutes (24%) for the prostate cases. Conclusions: Delivery times of intensity modulated proton therapy can be reduced substantially without compromising robust plan quality. Shorter delivery times are likely to reduce treatment uncertainties and costs.

  6. Flexible, durable proton energy degraders for the GE PETtrace

    SciTech Connect

    Engle, J. W.; Gagnon, K.; Severin, G. W.; Valdovinos, H. F.; Nickles, R. J.; Barnhart, T. E.

    2012-12-19

    In order to limit the formation of radioisotopic impurities during proton bombardments of solid targets, two methods of introducing degrader foils into the beam upstream of the target were tested. The first design uses a 445 {mu}m thick fixed degrader machined from a single piece of aluminum. The second design permits introduction of foils made of any material and was tested with foils as thick as 635 {mu}m (also aluminium). In both cases, the foils are cooled with by water flowing through an annular channel outside the radius of the beam. Both designs proved durable and tolerated proton beam currents in excess of 80 {mu}A.

  7. Evaluation of energy deposition and secondary particle production in proton therapy of brain using a slab head phantom

    PubMed Central

    Jia, Sayyed Bijan; Hadizadeh, Mohammad Hadi; Mowlavi, Ali Asghar; Loushab, Mahdy Ebrahimi

    2014-01-01

    Aim Evaluation of energy deposition of protons in human brain and calculation of the secondary neutrons and photons produced by protons in proton therapy. Background Radiation therapy is one of the main methods of treating localized cancer tumors. The use of high energy proton beam in radiotherapy was proposed almost 60 years ago. In recent years, there has been a revival of interest in this subject in the context of radiation therapy. High energy protons suffer little angular deflection and have a well-defined penetration range, with a sharp increase in the energy loss at the end of their trajectories, namely the Bragg peak. Materials and methods A slab head phantom was used for the purpose of simulating proton therapy in brain tissue. In this study simulation was carried out using the Monte Carlo MCNPX code. Results By using mono energetic proton pencil beams, energy depositions in tissues, especially inside the brain, as well as estimating the neutron and photon production as a result of proton interactions in the body, together with their energy spectra, were calculated or obtained. The amount of energy escaped from the head by secondary neutrons and photons was determined. Conclusions It was found that for high energy proton beams the amount of escaped energy by neutrons is almost 10 times larger than that by photons. We estimated that at 110 MeV beam energy, the overall proton energy “leaked” from the head by secondary photons and neutrons to be around 1%. PMID:25337410

  8. Investigation of gold nanoparticle radiosensitization mechanisms using a free radical scavenger and protons of different energies.

    PubMed

    Jeynes, J C G; Merchant, M J; Spindler, A; Wera, A-C; Kirkby, K J

    2014-11-01

    Gold nanoparticles (GNPs) have been shown to sensitize cancer cells to x-ray radiation, particularly at kV energies where photoelectric interactions dominate and the high atomic number of gold makes a large difference to x-ray absorption. Protons have a high cross-section for gold at a large range of relevant clinical energies, and so potentially could be used with GNPs for increased therapeutic effect.Here, we investigate the contribution of secondary electron emission to cancer cell radiosensitization and investigate how this parameter is affected by proton energy and a free radical scavenger. We simulate the emission from a realistic cell phantom containing GNPs after traversal by protons and x-rays with different energies. We find that with a range of proton energies (1-250 MeV) there is a small increase in secondaries compared to a much larger increase with x-rays. Secondary electrons are known to produce toxic free radicals. Using a cancer cell line in vitro we find that a free radical scavenger has no protective effect on cells containing GNPs irradiated with 3 MeV protons, while it does protect against cells irradiated with x-rays. We conclude that GNP generated free radicals are a major cause of radiosensitization and that there is likely to be much less dose enhancement effect with clinical proton beams compared to x-rays.

  9. Investigation of gold nanoparticle radiosensitization mechanisms using a free radical scavenger and protons of different energies

    NASA Astrophysics Data System (ADS)

    Jeynes, J. C. G.; Merchant, M. J.; Spindler, A.; Wera, A.-C.; Kirkby, K. J.

    2014-10-01

    Gold nanoparticles (GNPs) have been shown to sensitize cancer cells to x-ray radiation, particularly at kV energies where photoelectric interactions dominate and the high atomic number of gold makes a large difference to x-ray absorption. Protons have a high cross-section for gold at a large range of relevant clinical energies, and so potentially could be used with GNPs for increased therapeutic effect. Here, we investigate the contribution of secondary electron emission to cancer cell radiosensitization and investigate how this parameter is affected by proton energy and a free radical scavenger. We simulate the emission from a realistic cell phantom containing GNPs after traversal by protons and x-rays with different energies. We find that with a range of proton energies (1-250 MeV) there is a small increase in secondaries compared to a much larger increase with x-rays. Secondary electrons are known to produce toxic free radicals. Using a cancer cell line in vitro we find that a free radical scavenger has no protective effect on cells containing GNPs irradiated with 3 MeV protons, while it does protect against cells irradiated with x-rays. We conclude that GNP generated free radicals are a major cause of radiosensitization and that there is likely to be much less dose enhancement effect with clinical proton beams compared to x-rays.

  10. Cognitive effects of proton irradiation at differing energy levels

    Technology Transfer Automated Retrieval System (TEKTRAN)

    During exploratory class missions to space outside of the magnetic field of the Earth, astronauts will be exposed to various forms of radiation including solar particle events (SPE) which are predominantly composed of protons. As such it is important to characterize the cognitive effects of exposure...

  11. Propensity and risk assessment for solar particle events: Consideration of integral fluence at high proton energies

    NASA Astrophysics Data System (ADS)

    Kim, Myung-Hee; Hayat, Matthew; Feiveson, Alan; Cucinotta, Francis A.

    For future space missions with longer duration, exposure to large solar particle events (SPEs) with high energy levels is the major concern during extra-vehicular activities (EVAs) on the lunar and Mars surface. The propensity for SPE occurrence with large proton fluence was estimated as a function of time within a solar cycle from a non-homogeneous Poisson model using the historical database for measurements of protons with energy >30 MeV, Φ30 . The database includes a continuous data set for the past 5 solar cycles. The resultant SPE risk analysis for a specific mission period was made for blood forming organ (BFO) dose ranging from its 5th to 95th percentile. In addition to the total particle intensity of SPEs, the detailed energy spectra of protons, especially at high energy levels, were recognized as extremely important for assessing the cancer risk associated with energetic particles for large events. Using all the recorded proton fluence of SPEs for energies >60 and >100 MeV, Φ60 and Φ100 , respectively, the expected numbers of SPEs abundant with high energy protons were estimated from the same non-homogeneous Poisson model and the representative cancer risk was analyzed. The dependencies of risk with different energy spectra, for e.g. between soft and hard SPEs, were evaluated. Finally, we describe approaches to improve radiation protection of astronauts and optimize mission planning for future space missions.

  12. Propensity and Risk Assessment for Solar Particle Events: Consideration of Integral Fluence at High Proton Energies

    NASA Technical Reports Server (NTRS)

    Kim, Myung-Hee; Hayat, Matthew J.; Feiveson, alan H.; Cucinotta, Francis A.

    2008-01-01

    For future space missions with longer duration, exposure to large solar particle events (SPEs) with high energy levels is the major concern during extra-vehicular activities (EVAs) on the lunar and Mars surface. The expected SPE propensity for large proton fluence was estimated from a non-homogeneous Poisson model using the historical database for measurements of protons with energy > 30 MeV, Phi(sub 30). The database includes a continuous data set for the past 5 solar cycles. The resultant SPE risk analysis for a specific mission period was made including the 95% confidence level. In addition to total particle intensity of SPE, the detailed energy spectra of protons especially at high energy levels were recognized as extremely important parameter for the risk assessment, since there remains a significant cancer risks from those energetic particles for large events. Using all the recorded proton fluence of SPEs for energies >60 and >100 MeV, Phi(sub 60) and Phi(sub 100), respectively, the expected propensities of SPEs abundant with high energy protons were estimated from the same non-homogeneous Poisson model and the representative cancer risk was analyzed. The dependencies of risk with different energy spectra, for e.g. between soft and hard SPEs, were evaluated. Finally, we describe approaches to improve radiation protection of astronauts and optimize mission planning for future space missions.

  13. The energy spectra of solar energetic protons in the large energy range: their functional form and parameters.

    NASA Astrophysics Data System (ADS)

    Nymmik, Rikho; Pervaia, Taisia

    2016-07-01

    Experimental data on the fluxes of protons of solar energetic particles (SEP) are analyzed. It is known that above energies of 2-45 MeV (averaging 27-30 MeV), the proton spectra are a power-law function of the energy (at relativistic energies - from the momentum) of the particles. At lower energies, the spectra become harder, with the high-energy part of the spectra forming the "knee". This report is devoted to the determination of the parameters of the SEP spectra, having the form of a "double power-law shape", to ascertain the reliability of the parameters of the approximations of the experimental data.

  14. Response of a tungsten powder target to an incident high energy proton beam

    NASA Astrophysics Data System (ADS)

    Caretta, O.; Davenne, T.; Densham, C.; Fitton, M.; Loveridge, P.; O'Dell, J.; Charitonidis, N.; Efthymiopoulos, I.; Fabich, A.; Rivkin, L.

    2014-10-01

    The experiment described in this paper is the first study of the response of a static tungsten powder sample to an impinging high energy proton beam pulse. The experiment was carried out at the HiRadMat facility at CERN. Observations include high speed videos of a proton beam induced perturbation of the powder sample as well as data from a laser Doppler vibrometer measuring the oscillations of the powder container. A comparison with a previous analogous experiment which studied a proton beam interaction with mercury is made.

  15. A Nuclear Interaction Model for Understanding Results of Single Event Testing with High Energy Protons

    NASA Technical Reports Server (NTRS)

    Culpepper, William X.; ONeill, Pat; Nicholson, Leonard L.

    2000-01-01

    An internuclear cascade and evaporation model has been adapted to estimate the LET spectrum generated during testing with 200 MeV protons. The model-generated heavy ion LET spectrum is compared to the heavy ion LET spectrum seen on orbit. This comparison is the basis for predicting single event failure rates from heavy ions using results from a single proton test. Of equal importance, this spectra comparison also establishes an estimate of the risk of encountering a failure mode on orbit that was not detected during proton testing. Verification of the general results of the model is presented based on experiments, individual part test results, and flight data. Acceptance of this model and its estimate of remaining risk opens the hardware verification philosophy to the consideration of radiation testing with high energy protons at the board and box level instead of the more standard method of individual part testing with low energy heavy ions.

  16. Technical Support Document: 50% Energy Savings Design Technology Packages for Medium Office Buildings

    SciTech Connect

    Thornton, Brian A.; Wang, Weimin; Lane, Michael D.; Rosenberg, Michael I.; Liu, Bing

    2009-09-01

    This Technical Support Document (TSD) describes the process and methodology for development of the Advanced Energy Design Guide for Medium Offices (AEDG-MO or the Guide), a design guidance document which intends to provide recommendations for achieving 50% energy savings in medium office buildings that just meet the requirements of ANSI/ASHRAE/IESNA Standard 90.1-2004, Energy Standard for Buildings Except Low-Rise Residential Buildings.

  17. VHEeP: a very high energy electron-proton collider

    NASA Astrophysics Data System (ADS)

    Caldwell, A.; Wing, M.

    2016-08-01

    Based on current CERN infrastructure, an electron-proton collider is proposed at a centre-of-mass energy of about 9 TeV. A 7 TeV LHC bunch is used as the proton driver to create a plasma wakefield which then accelerates electrons to 3 TeV, these then colliding with the other 7 TeV LHC proton beam. Although of very high energy, the collider has a modest projected integrated luminosity of 10-100 pb^{-1}. For such a collider, with a centre-of-mass energy 30 times greater than HERA, parton momentum fractions, x, down to about 10^{-8} are accessible for photon virtualities, Q^2, of 1 GeV^2. The energy dependence of hadronic cross sections at high energies, such as the total photon-proton cross section, which has synergy with cosmic-ray physics, can be measured and QCD and the structure of matter better understood in a region where the effects are completely unknown. Searches at high Q^2 for physics beyond the Standard Model will be possible, in particular the significantly increased sensitivity to the production of leptoquarks. These and other physics highlights of a very high energy electron-proton collider are outlined.

  18. Energy- and time-resolved detection of prompt gamma-rays for proton range verification

    NASA Astrophysics Data System (ADS)

    Verburg, Joost M.; Riley, Kent; Bortfeld, Thomas; Seco, Joao

    2013-10-01

    In this work, we present experimental results of a novel prompt gamma-ray detector for proton beam range verification. The detection system features an actively shielded cerium-doped lanthanum(III) bromide scintillator, coupled to a digital data acquisition system. The acquisition was synchronized to the cyclotron radio frequency to separate the prompt gamma-ray signals from the later-arriving neutron-induced background. We designed the detector to provide a high energy resolution and an effective reduction of background events, enabling discrete proton-induced prompt gamma lines to be resolved. Measuring discrete prompt gamma lines has several benefits for range verification. As the discrete energies correspond to specific nuclear transitions, the magnitudes of the different gamma lines have unique correlations with the proton energy and can be directly related to nuclear reaction cross sections. The quantification of discrete gamma lines also enables elemental analysis of tissue in the beam path, providing a better prediction of prompt gamma-ray yields. We present the results of experiments in which a water phantom was irradiated with proton pencil-beams in a clinical proton therapy gantry. A slit collimator was used to collimate the prompt gamma-rays, and measurements were performed at 27 positions along the path of proton beams with ranges of 9, 16 and 23 g cm-2 in water. The magnitudes of discrete gamma lines at 4.44, 5.2 and 6.13 MeV were quantified. The prompt gamma lines were found to be clearly resolved in dimensions of energy and time, and had a reproducible correlation with the proton depth-dose curve. We conclude that the measurement of discrete prompt gamma-rays for in vivo range verification of clinical proton beams is feasible, and plan to further study methods and detector designs for clinical use.

  19. Energy relaxation of multi-MeV protons traveling in compressed DT+Be plasmas

    SciTech Connect

    Wang, Zhigang; He, Bin; Fu, Zhen-Guo; Zhang, Ping

    2014-07-15

    We investigate the stopping power of the multi-MeV protons moving in the hot dense deuterium-tritium plasmas mixed with beryllium (Be), which is important in inertial confinement fusion experiments. It is shown that with increasing the density of Be, the stopping power of the proton also increases with the peaks shifting towards higher projectile velocity, which leads to the reduction of both the projectile range and the energy transferred to the electrons.

  20. Energy- and time-resolved detection of prompt gamma-rays for proton range verification.

    PubMed

    Verburg, Joost M; Riley, Kent; Bortfeld, Thomas; Seco, Joao

    2013-10-21

    In this work, we present experimental results of a novel prompt gamma-ray detector for proton beam range verification. The detection system features an actively shielded cerium-doped lanthanum(III) bromide scintillator, coupled to a digital data acquisition system. The acquisition was synchronized to the cyclotron radio frequency to separate the prompt gamma-ray signals from the later-arriving neutron-induced background. We designed the detector to provide a high energy resolution and an effective reduction of background events, enabling discrete proton-induced prompt gamma lines to be resolved. Measuring discrete prompt gamma lines has several benefits for range verification. As the discrete energies correspond to specific nuclear transitions, the magnitudes of the different gamma lines have unique correlations with the proton energy and can be directly related to nuclear reaction cross sections. The quantification of discrete gamma lines also enables elemental analysis of tissue in the beam path, providing a better prediction of prompt gamma-ray yields. We present the results of experiments in which a water phantom was irradiated with proton pencil-beams in a clinical proton therapy gantry. A slit collimator was used to collimate the prompt gamma-rays, and measurements were performed at 27 positions along the path of proton beams with ranges of 9, 16 and 23 g cm(-2) in water. The magnitudes of discrete gamma lines at 4.44, 5.2 and 6.13 MeV were quantified. The prompt gamma lines were found to be clearly resolved in dimensions of energy and time, and had a reproducible correlation with the proton depth-dose curve. We conclude that the measurement of discrete prompt gamma-rays for in vivo range verification of clinical proton beams is feasible, and plan to further study methods and detector designs for clinical use.

  1. Proton collisions with the water dimer at keV energies

    NASA Astrophysics Data System (ADS)

    Quinet, O.; Deumens, E.; Öhrn, Y.

    Proton collisions with the water dimer are studied using a nonadiabatic, direct, time-dependent approach called electron nuclear dynamics (END). Fragmentation of the water dimer in collisions with protons at energies of 5.0, 1.0 keV and 200 eV is the primary aim of this initial study of water clusters using END. We report on the initial fragmentation dynamic, that is, for times less than 200 fs.

  2. Differences in excitation energy transfer of Arthrospira platensis cells grown in seawater medium and freshwater medium, probed by time-resolved fluorescence spectroscopy

    NASA Astrophysics Data System (ADS)

    Arba, Muhammad; Aikawa, Shimpei; Niki, Kenta; Yokono, Makio; Kondo, Akihiko; Akimoto, Seiji

    2013-11-01

    Excitation energy transfer of Arthrospira platensis cells grown in f/2 medium (a high salinity medium) and SOT medium (a control) was investigated by steady-state and time-resolved spectroscopies. Growth in f/2 medium induced changes in absorption and fluorescence spectra as well as in the energy transfer pathways. Excitation energy captured by phycobilisome (PBS) was transferred directly to photosystem (PS) I, instead of being first transferred to an intermediate (PBS → PSII → PSI), as observed in SOT medium. The respiration rate increased while photosynthetic rate reduced in f/2 medium. Possible causes of the differences in light-harvesting and energy-transfer processes between the two media are discussed.

  3. Microstructured snow targets for high energy quasi-monoenergetic proton acceleration

    NASA Astrophysics Data System (ADS)

    Schleifer, E.; Nahum, E.; Eisenmann, S.; Botton, M.; Baspaly, A.; Pomerantz, I.; Abricht, F.; Branzel, J.; Priebe, G.; Steinke, S.; Andreev, A.; Schnuerer, M.; Sandner, W.; Gordon, D.; Sprangle, P.; Ledingham, K. W. D.; Zigler, A.

    2013-05-01

    Compact size sources of high energy protons (50-200MeV) are expected to be key technology in a wide range of scientific applications 1-8. One promising approach is the Target Normal Sheath Acceleration (TNSA) scheme 9,10, holding record level of 67MeV protons generated by a peta-Watt laser 11. In general, laser intensity exceeding 1018 W/cm2 is required to produce MeV level protons. Another approach is the Break-Out Afterburner (BOA) scheme which is a more efficient acceleration scheme but requires an extremely clean pulse with contrast ratio of above 10-10. Increasing the energy of the accelerated protons using modest energy laser sources is a very attractive task nowadays. Recently, nano-scale targets were used to accelerate ions 12,13 but no significant enhancement of the accelerated proton energy was measured. Here we report on the generation of up to 20MeV by a modest (5TW) laser system interacting with a microstructured snow target deposited on a Sapphire substrate. This scheme relax also the requirement of high contrast ratio between the pulse and the pre-pulse, where the latter produces the highly structured plasma essential for the interaction process. The plasma near the tip of the snow target is subject to locally enhanced laser intensity with high spatial gradients, and enhanced charge separation is obtained. Electrostatic fields of extremely high intensities are produced, and protons are accelerated to MeV-level energies. PIC simulations of this targets reproduce the experimentally measured energy scaling and predict the generation of 150 MeV protons from laser power of 100TW laser system18.

  4. High-energy gamma-ray emission from solar flares: Constraining the accelerated proton spectrum

    NASA Technical Reports Server (NTRS)

    Alexander, David; Dunphy, Philip P.; Mackinnon, Alexander L.

    1994-01-01

    Using a multi-component model to describe the gamma-ray emission, we investigate the flares of December 16, 1988 and March 6, 1989 which exhibited unambiguous evidence of neutral pion decay. The observations are then combined with theoretical calculations of pion production to constrain the accelerated proton spectra. The detection of pi(sup 0) emission alone can indicate much about the energy distribution and spectral variation of the protons accelerated to pion producing energies. Here both the intensity and detailed spectral shape of the Doppler-broadened pi(sup 0) decay feature are used to determine the spectral form of the accelerated proton energy distribution. The Doppler width of this gamma-ray emission provides a unique diagnostic of the spectral shape at high energies, independent of any normalisation. To our knowledge, this is the first time that this diagnostic has been used to constrain the proton spectra. The form of the energetic proton distribution is found to be severely limited by the observed intensity and Doppler width of the pi(sup 0) decay emission, demonstrating effectively the diagnostic capabilities of the pi(sup 0) decay gamma-rays. The spectral index derived from the gamma-ray intensity is found to be much harder than that derived from the Doppler width. To reconcile this apparent discrepancy we investigate the effects of introducing a high-energy cut-off in the accelerated proton distribution. With cut-off energies of around 0.5-0.8 GeV and relatively hard spectra, the observed intensities and broadening can be reproduced with a single energetic proton distribution above the pion production threshold.

  5. Proton transfer and energy coupling in the bacteriorhodopsin photocycle

    NASA Technical Reports Server (NTRS)

    Lanyi, J. K.

    1992-01-01

    A description of the rate constants and the energetics of the elementary reaction steps of the photocycle of bacteriorhodopsin has been helpful in understanding the mechanism of proton transport in this light-driven pump. The evidence suggests a single unbranched reaction sequence, BR-hv----K in equilibrium with L in equilibrium with M1----M2 in equilibrium with N in equilibrium with O----BR, where coupling to the proton-motive force is at the energetically and mechanistically important M1----M2 step. The consequences of site-specific mutations expressed homologously in Halobacterium halobium have revealed characteristics of the Schiff base deprotonation in the L----M1 reaction, the reorientation of the Schiff base from the extracellular to the cytoplasmic side in the M1----M2 reaction, and the reprotonation of the Schiff base in the M2----N reaction.

  6. Isochoric heating of matter by laser-accelerated high-energy protons

    NASA Astrophysics Data System (ADS)

    Antici, P.; Fuchs, J.; Atzeni, S.; Benuzzi, A.; Brambrink, E.; Esposito, M.; Koenig, M.; Ravasio, A.; Schreiber, J.; Schiavi, A.; Audebert, P.

    2006-06-01

    We describe an experiment on isochoric heating of matter by intense laser-accelerated protons. The experiment was performed using the LULI 100 TW facility with 15-20 J on target energy and > 1019 W.cm - 2 maximum focused intensity. Focusing the laser on a 10 micron thick Au foil, we accelerated forward a laminar proton beam with a maximum energy of 16 MeV. This proton beam irradiated and heated a secondary target positioned after a variable vacuum gap. The heating was diagnosed by 1D and 2D time-resolved measurements of the optical self-emission of the heated target rear-surface. Detailed results as a function of the Z and the thickness of the secondary target as well as analysis, including a full modelling of the target heating with a 2D hydro-code (DUED) coupled to a proton energy deposition code, were obtained. We have also studied the efficiency of heating as a function of the primary target topology, i.e. either flat, which results in a diverging proton beam, or curved, which has the ability of focusing partly the proton beam.

  7. Metamaterial-based lossy anisotropic epsilon-near-zero medium for energy collimation

    NASA Astrophysics Data System (ADS)

    Shen, Nian-Hai; Zhang, Peng; Koschny, Thomas; Soukoulis, Costas M.

    2016-06-01

    A lossy anisotropic epsilon-near-zero (ENZ) medium may lead to a counterintuitive phenomenon of omnidirectional bending-to-normal refraction [S. Feng, Phys. Rev. Lett. 108, 193904 (2012), 10.1103/PhysRevLett.108.193904], which offers a fabulous strategy for energy collimation and energy harvesting. Here, in the scope of effective medium theory, we systematically investigate two simple metamaterial configurations, i.e., metal-dielectric-layered structures and the wire medium, to explore the possibility of fulfilling the conditions of such an anisotropic lossy ENZ medium by playing with materials' parameters. Both realistic metamaterial structures and their effective medium equivalences have been numerically simulated, and the results are in excellent agreement with each other. Our study provides clear guidance and therefore paves the way towards the search for proper designs of anisotropic metamaterials for a decent effect of energy collimation and wave-front manipulation.

  8. Measurement of high energy resolution inelastic proton scattering at and close to zero degrees

    NASA Astrophysics Data System (ADS)

    Tamii, A.; Fujita, Y.; Matsubara, H.; Adachi, T.; Carter, J.; Dozono, M.; Fujita, H.; Fujita, K.; Hashimoto, H.; Hatanaka, K.; Itahashi, T.; Itoh, M.; Kawabata, T.; Nakanishi, K.; Ninomiya, S.; Perez-Cerdan, A. B.; Popescu, L.; Rubio, B.; Saito, T.; Sakaguchi, H.; Sakemi, Y.; Sasamoto, Y.; Shimbara, Y.; Shimizu, Y.; Smit, F. D.; Tameshige, Y.; Yosoi, M.; Zenhiro, J.

    2009-07-01

    Measurements of inelastic proton scattering with high energy resolution at forward scattering angles including 0∘ are described. High-resolution halo-free beams were accelerated by the cyclotron complex at the Research Center for Nuclear Physics. Instrumental background events were minimized using the high-quality beam. The remaining instrumental background events were eliminated by applying a background subtraction method. As a result, clean spectra were obtained even for a heavy target nucleus such as Pb208. A high energy resolution of 20 keV (FWHM) and a scattering angle resolution of ±0.6∘ were achieved at an incident proton energy of 295 MeV.

  9. The effect of low energy protons on silicon solar cells with simulated coverglass cracks

    NASA Technical Reports Server (NTRS)

    Gasner, S.; Anspaugh, B.; Francis, R.; Marvin, D.

    1991-01-01

    Results of a series of low-energy proton (LEP) tests are presented. The purpose of the tests was to investigate the effect of low-energy protons on the electrical performance of solar cells with simulated cracked covers. The results of the tests were then related to the space environment. A matrix of LEP tests was set up using solar cells with simulated cracks to determine the effect on electrical performance as a function of fluence, energy, crack width, coverglass adhesive shielding, crack location, and solar cell size. The results of the test were, for the most part, logical, and consistent.

  10. Cylindrical radiant energy direction device with refractive medium

    DOEpatents

    Winston, Roland

    1978-01-01

    A device is provided for directing radiant energy and includes a refractive element and a reflective boundary. The reflective boundary is so contoured that incident energy directed thereto by the refractive element is directed to the exit surface thereof or onto the surface of an energy absorber positioned at the exit surface.

  11. Medium-energy ion-beam simulation of the effect of ionizing radiation and displacement damage on SiO2-based memristive nanostructures

    NASA Astrophysics Data System (ADS)

    Belov, Alexey; Mikhaylov, Alexey; Korolev, Dmitry; Guseinov, Davud; Gryaznov, Eugeny; Okulich, Eugenia; Sergeev, Victor; Antonov, Ivan; Kasatkin, Alexandr; Gorshkov, Oleg; Tetelbaum, David; Kozlovski, Vitali

    2016-07-01

    The principles of ion-beam simulation of the effect of fast (fission) neutrons and high-energy protons based on medium-energy ion irradiation have been developed for the Au/Zr/SiO2/TiN/Ti capacitor-like memristive nanostructures demonstrating the repeatable resistive switching phenomenon. By using the Monte-Carlo approach, the irradiation fluences of H+, Si+ and O+ ions at the energy of 150 keV are determined that provide the ionization and displacement damage equivalent to the cases of space protons (15 MeV) and fission neutrons (1 MeV) irradiation. No significant change in the resistive switching parameters is observed under ion irradiation up to the fluences corresponding to the extreme fluence of 1017 cm-2 of space protons or fission neutrons. The high-level radiation tolerance of the memristive nanostructures is experimentally confirmed with the application of 15 MeV proton irradiation and is interpreted as related to the local nature of conducting filaments and high concentration of the initial field-induced defects in oxide film.

  12. New limit on the low-energy antiproton/proton ratio in the Galactic cosmic radiation

    NASA Technical Reports Server (NTRS)

    Ahlen, S. P.; Beatty, J. J.; Barwick, S.; Gerbier, G.; Bower, C. R.

    1988-01-01

    Results are presented from a balloon-borne apparatus searching for low-energy antiprotons in the Galactic cosmic rays. For energies less than 640 MeV at the top of the atmosphere, no cosmic-ray antiprotons were observed. This yields an upper limit to the antiproton/proton ratio of 0.000046 at the 85-percent confidence level.

  13. High-energy proton radiation damage of high-purity germanium detectors

    NASA Technical Reports Server (NTRS)

    Pehl, R. H.; Varnell, L. S.; Metzger, A. E.

    1978-01-01

    Quantitative studies of radiation damage in high-purity germanium gamma-ray detectors due to high-energy charged particles have been carried out; two 1.0 cm thick planar detectors were irradiated by 6 GeV/c protons. Under proton bombardment, degradation in the energy resolution was found to begin below 7 x 10 to the 7th protons/sq cm and increased proportionately in both detectors until the experiment was terminated at a total flux of 5.7 x 10 to the 8th protons/sq cm, equivalent to about a six year exposure to cosmic-ray protons in space. At the end of the irradiation, the FWHM resolution measured at 1332 keV stood at 8.5 and 13.6 keV, with both detectors of only marginal utility as a spectrometer due to the severe tailing caused by charge trapping. Annealing these detectors after proton damage was found to be much easier than after neutron damage.

  14. Results on damage induced by high-energy protons in LYSO calorimeter crystals

    NASA Astrophysics Data System (ADS)

    Dissertori, G.; Luckey, D.; Nessi-Tedaldi, F.; Pauss, F.; Quittnat, M.; Wallny, R.; Glaser, M.

    2014-05-01

    Lutetium-Yttrium Orthosilicate doped with Cerium (LYSO), as a bright scintillating crystal, is a candidate for calorimetry applications in strong ionising-radiation fields and large high-energy hadron fluences are expected at the CERN Large Hadron Collider after the planned High-Luminosity upgrade. There, proton-proton collisions will produce fast hadron fluences up to ~ 5 ×1014cm-2 in the large-rapidity regions of the calorimeters. The performance of LYSO has been investigated, after exposure to different fluences of 24 GeV c-1 protons. Measured changes in optical transmission as a function of proton fluence are presented, and the evolution over time due to spontaneous recovery at room temperature is studied. The activation of materials will also be an issue in the described environment. Studies of the ambient dose induced by LYSO and its evolution with time, in comparison with other scintillating crystals, have also been performed through measurements and FLUKA simulations.

  15. LDEF (Postflight), M0002-01 : Trapped-Proton Energy Spectrum Determination, Tray G12

    NASA Technical Reports Server (NTRS)

    1990-01-01

    The postflight photograph was taken in SAEF II at KSC after the experiment tray was removed from the LDEF. The Trapped Proton Energy Spectrum Determination Experiment is one of four experiments located in a three (3) inch deep LDEF end center tray. Additional Trapped Proton Energy Experiments are located in periph eral LDEF integrated experiment trays in the D03 and D09 tray locations. The Trapped Proton Energy experiment, located in the upper left quadrant of the integrated tray, appears to be intact with no apparent physical damage. The brown discoloration appears to be much lighter in this photograph than in the flight photograph, however, the postflight photograph of the individual experiment verifies the darker discoloration in the flight photograph. The light ing angle and intensity appear to have washed out the colors in the upper half of the integrated tray. The sub experiments appear to be intact and secure.

  16. Radiobiological Characterization of Two Therapeutic Proton Beams With Different Initial Energy Spectra Used at the Institut Curie Proton Therapy Center in Orsay

    SciTech Connect

    Calugaru, Valentin; Nauraye, Catherine; Noeel, Georges; Giocanti, Nicole; Favaudon, Vincent; Megnin-Chanet, Frederique

    2011-11-15

    Purpose: Treatment planning in proton therapy uses a generic value for the relative biological efficiency (RBE) of 1.1 throughout the spread-out Bragg peak (SOBP) generated. In this article, we report on the variation of the RBE with depth in the SOBP of the 76- and 201-MeV proton beams used for treatment at the Institut Curie Proton Therapy Center in Orsay. Methods and Materials: The RBE (relative to {sup 137}Cs {gamma}-rays) of the two modulated proton beams at three positions in the SOBP was determined in two human tumor cells using as endpoints clonogenic cell survival and the incidence of DNA double-strand breaks (DSBs) as measured by pulse-field gel electrophoresis without and with enzymatic treatment to reveal clustered lesions. Results: The RBE for induced cell killing by the 76-MeV beam increased with depth in the SOBP. However for the 201-MeV protons, it was close to that for {sup 137}Cs {gamma}-rays and did not vary significantly. The incidence of DSBs and clustered lesions was higher for protons than for {sup 137}Cs {gamma}-rays, but did not depend on the proton energy or the position in the SOBP. Conclusions: Until now, little attention has been paid to the variation of RBE with depth in the SOBP as a function of the nominal energy of the primary proton beam and the molecular nature of the DNA damage. The RBE increase in the 76-MeV SOBP implies that the tumor tissues at the distal end receives a higher biologically equivalent dose than at the proximal end, despite a homogeneous physical dose. This is not the case for the 201-MeV energy beam. The precise determination of the effects of incident beam energy, modulation, and depth in tissues on the linear energy transfer-RBE relationship is essential for treatment planning.

  17. Significance of medium energy gamma ray astronomy in the study of cosmic rays

    NASA Technical Reports Server (NTRS)

    Fichtel, C. E.; Kniffen, D. A.; Thompson, D. J.; Bignami, G. F.; Cheung, C. Y.

    1975-01-01

    Medium energy (about 10 to 30 MeV) gamma ray astronomy provides information on the product of the galactic electron cosmic ray intensity and the galactic matter to which the electrons are dynamically coupled by the magnetic field. Because high energy (greater than 100 MeV) gamma ray astronomy provides analogous information for the nucleonic cosmic rays and the relevant matter, a comparison between high energy and medium energy gamma ray intensities provides a direct ratio of the cosmic ray electrons and nucleons throughout the galaxy. A calculation of gamma ray production by electron bremsstrahlung shows that: bremsstrahlung energy loss is probably not negligible over the lifetime of the electrons in the galaxy; and the approximate bremsstrahlung calculation often used previously overestimates the gamma ray intensity by about a factor of two. As a specific example, expected medium energy gamma ray intensities are calculated for the speral arm model.

  18. Transverse momentum distributions in proton-proton collisions at LHC energies and Tsallis thermodynamics

    NASA Astrophysics Data System (ADS)

    Azmi, M. D.; Cleymans, J.

    2014-06-01

    A detailed study of the transverse momentum distributions of charged particles produced in p-p collisions at large hadron collider energies is presented. This is done using a thermodynamically consistent form of the Tsallis distribution. All variables used are thermodynamical and in particular, the temperature, T, follows from the standard thermodynamic definition as being the derivative of the energy with respect to the (Tsallis) entropy. The momentum distribution of the final state particles can be described very well by the Tsallis distribution. The values of the parameters are determined from measurements by the ALICE, ATLAS and CMS collaborations and are discussed in detail. In particular, the Tsallis parameter, q, is found with consistent values for all the transverse momentum distributions despite large differences in kinematic regions and shows a slight increase with beam energy, reaching a value of 1.15 at 7 TeV. It is concluded that the hadronic system created in high-energy p-p collisions at mid-rapidity is consistent with Tsallis thermodynamics.

  19. On the energy dependence of proton beam extraction with a bent crystal

    NASA Astrophysics Data System (ADS)

    Arduini, G.; Elsener, K.; Fidecaro, G.; Gyr, M.; Herr, W.; Klem, J.; Mikkelsen, U.; Weisse, E.

    1998-03-01

    Proton beam extraction from the CERN SPS by means of a bent silicon crystal is reported at three different energies, 14 GeV, 120 GeV and 270 GeV. The experimental results are compared to computer simulations which contain a sound model of the SPS accelerator as well as the channeling phenomena in bent crystals. The overall energy dependence of crystal assisted proton beam extraction is understood and provides the basis to discuss such a scheme for future accelerators. © 1998

  20. Development of an energy selector system for laser-driven proton beam applications

    NASA Astrophysics Data System (ADS)

    Scuderi, V.; Bijan Jia, S.; Carpinelli, M.; Cirrone, G. A. P.; Cuttone, G.; Korn, G.; Licciardello, T.; Maggiore, M.; Margarone, D.; Pisciotta, P.; Romano, F.; Schillaci, F.; Stancampiano, C.; Tramontana, A.

    2014-03-01

    Nowadays, laser-driven proton beams generated by the interaction of high power lasers with solid targets represent a fascinating attraction in the field of the new acceleration techniques. These beams can be potentially accelerated up to hundreds of MeV and, therefore, they can represent a promising opportunity for medical applications. Laser-accelerated proton beams typically show high flux (up to 1011 particles per bunch), very short temporal profile (ps), broad energy spectra and poor reproducibility. In order to overcome these limitations, these beams have be controlled and transported by means of a proper beam handling system. Furthermore, suitable dosimetric diagnostic systems must be developed and tested. In the framework of the ELIMED project, we started to design a dedicated beam transport line and we have developed a first prototype of a beam line key-element: an Energy Selector System (ESS). It is based on permanent dipoles, capable to control and select in energy laser-accelerated proton beams. Monte Carlo simulations and some preliminary experimental tests have been already performed to characterize the device. A calibration of the ESS system with a conventional proton beam will be performed in September at the LNS in Catania. Moreover, an experimental campaign with laser-driven proton beam at the Centre for Plasma Physics, Queens University in Belfast is already scheduled and will be completed within 2014.

  1. Baseline measures for net-proton distributions in high energy heavy-ion collisions

    NASA Astrophysics Data System (ADS)

    Netrakanti, P. K.; Luo, X. F.; Mishra, D. K.; Mohanty, B.; Mohanty, A.; Xu, N.

    2016-03-01

    We report a systematic comparison of the recently measured cumulants of the net-proton distributions for 0-5% central Au + Au collisions in the first phase of the Beam Energy Scan (BES) Program at the Relativistic Heavy Collider facility to various kinds of possible baseline measures. These baseline measures correspond to an assumption that the proton and anti-proton distributions follow Poisson statistics, Binomial statistics, obtained from a transport model calculation and from a hadron resonance gas model. The higher order cumulant net-proton data for the center of mass energies (√{sNN}) of 19.6 and 27 GeV are observed to deviate from most of the baseline measures studied. The deviations are predominantly due to the difference in shape of the proton distributions between data and those obtained in the baseline measures. We also present a detailed study on the relevance of the independent production approach as a baseline for comparison with the measurements at various beam energies. Our studies point to the need of either more detailed baseline models for the experimental measurements or a description via QCD calculations in order to extract the exact physics process that leads to deviation of the data from the baselines presented.

  2. Optimization of the {sup 7}Li(p,n) proton beam energy for BNCT applications

    SciTech Connect

    Bleuel, B.L.; Donahue, R.J.

    1996-05-01

    The reaction {sup 7}Li(p,n){sup 7} Be has been proposed as an accelerator-based source of neutrons for Boron Neutron Capture Therapy (BNCT). This reaction has a large steep resonance for proton energies of about 2.3 MeV which ends at about 2.5 MeV. It has generally been accepted that one should use 2.5 MeV protons to get the highest yield of neutrons for BNCT. This paper suggests that for BNCT the optimum proton energy may be about 2.3 MeV and that a proton energy of about 2.2 MeV will provide the same useful neutron flux outside a thinner moderator as the neutron flux from a 2.5 MeV proton beam with a, thicker moderator. These results are based on optimization of the useful neutron spectrum in air at the point of irradiation, not on depth-dose profiles in tissue/tumor.

  3. Partial cross sections of helium satellites at medium photon energies

    SciTech Connect

    Wehlitz, R.; Sellin, I.A.; Hemmers, O.

    1997-04-01

    Still of current interest is the important role of single ionization with excitation compared to single ionization alone. The coupling between the electrons and the incoming photon is a single-particle operator. Thus, an excitation in addition to an ionization, leading to a so-called satellite line in a photoelectron spectrum, is entirely due to electron-electron interaction and probes the electron correlation in the ground and final state. Therefore the authors have undertaken the study of the intensity of helium satellites He{sup +}nl (n = 2 - 6) relative to the main photoline (n = 1) as a function of photon energy at photon energies well above threshold up to 900 eV. From these results they could calculate the partial cross-sections of the helium satellites. In order to test the consistency of their satellite-to-1s ratios with published double-to-single photoionization ratios, the authors calculated the double-to-single photoionization ratio from their measured ratios using the theoretical energy-distribution curves of Chang and Poe and Le Rouzo and Dal Cappello which proved to be valid for photon energies below 120 eV. These calculated double-to-single ionization ratios agree fairly well with recent ion measurements. In the lower photon energy range the authors ratios agree better with the ratios of Doerner et al. while for higher photon energies the agreement is better with the values of Levin et al.

  4. Effects of very low fluences of high-energy protons or iron ions on irradiated and bystander cells.

    PubMed

    Yang, H; Magpayo, N; Rusek, A; Chiang, I-H; Sivertz, M; Held, K D

    2011-12-01

    In space, astronauts are exposed to radiation fields consisting of energetic protons and high atomic number, high-energy (HZE) particles at very low dose rates or fluences. Under these conditions, it is likely that, in addition to cells in an astronaut's body being traversed by ionizing radiation particles, unirradiated cells can also receive intercellular bystander signals from irradiated cells. Thus this study was designed to determine the dependence of DNA damage induction on dose at very low fluences of charged particles. Novel techniques to quantify particle fluence have been developed at the NASA Space Radiation Biology Laboratory (NSRL) at Brookhaven National Laboratory (BNL). The approach uses a large ionization chamber to visualize the radiation beam coupled with a scintillation counter to measure fluence. This development has allowed us to irradiate cells with 1 GeV/nucleon protons and iron ions at particle fluences as low as 200 particles/cm(2) and quantify biological responses. Our results show an increased fraction of cells with DNA damage in both the irradiated population and bystander cells sharing medium with irradiated cells after low fluences. The fraction of cells with damage, manifest as micronucleus formation and 53BP1 focus induction, is about 2-fold higher than background at doses as low as ∼0.47 mGy iron ions (∼0.02 iron ions/cell) or ∼70 μGy protons (∼2 protons/cell). In the irradiated population, irrespective of radiation type, the fraction of damaged cells is constant from the lowest damaging fluence to about 1 cGy, above which the fraction of damaged cells increases with dose. In the bystander population, the level of damage is the same as in the irradiated population up to 1 cGy, but it does not increase above that plateau level with increasing dose. The data suggest that at fluences of high-energy protons or iron ions less than about 5 cGy, the response in irradiated cell populations may be dominated by the bystander response.

  5. The energy dependence of lithium formate and alanine EPR dosimeters for medium energy x rays

    SciTech Connect

    Waldeland, Einar; Hole, Eli Olaug; Sagstuen, Einar; Malinen, Eirik

    2010-07-15

    Purpose: To perform a systematic investigation of the energy dependence of alanine and lilthium formate EPR dosimeters for medium energy x rays. Methods: Lithium formate and alanine EPR dosimeters were exposed to eight different x-ray beam qualities, with nominal potentials ranging from 50 to 200 kV. Following ionometry based on standards of absorbed dose to water, the dosimeters were given two different doses of approximately 3 and 6 Gy for each radiation quality, with three dosimeters for each dose. A reference series was also irradiated to three different dose levels at a {sup 60}Co unit. The dose to water energy response, that is, the dosimeter reading per absorbed dose to water relative to that for {sup 60}Co {gamma}-rays, was estimated for each beam quality. In addition, the energy response was calculated by Monte Carlo simulations and compared to the experimental energy response. Results: The experimental energy response estimates ranged from 0.89 to 0.94 and from 0.68 to 0.90 for lithium formate and alanine, respectively. The uncertainties in the experimental energy response estimates were typically 3%. The relative effectiveness, that is, the ratio of the experimental energy response to that following Monte Carlo simulations was, on average, 0.96 and 0.94 for lithium formate and alanine, respectively. Conclusions: This work shows that lithium formate dosimeters are less dependent on x-ray energy than alanine. Furthermore, as the relative effectiveness for both lithium formate and alanine were systematically less than unity, the yield of radiation-induced radicals is decreased following x-irradiation compared to irradiation with {sup 60}Co {gamma}-rays.

  6. High energy proton-proton elastic scattering at the Large Hadron Collider and nucleon structure

    NASA Astrophysics Data System (ADS)

    Luddy, Richard Joseph

    To gain insight into the structure of the nucleon, we pursue the development of the phenomenological model of Islam et al. (IIFS model) for high energy elastic pp and p¯p scattering. We determine the energy dependence of the parameters of the IIFS model using the available elastic differential cross section data from SPS Collider and Tevatron and the known asymptotic behavior of sigmatot (s) and rho(s) from dispersion relation calculations and more recent analyses of Cudell et al. (COMPETE Collaboration). Next, we incorporate a high energy elastic valence quark-quark scattering amplitude into the model based on BFKL pomeron to describe small impact parameter (large | t|) pp collisions. Finally, we predict the pp elastic differential cross section at the unprecedented c.m. energy of s = 14.0 TeV at the Large Hadron Collider (LHC). This prediction assumes crucial significance---because of an approved experiment at LHC: TOTal and Elastic Measurement (TOTEM). The TOTEM group plans to measure pp elastic dsigma/dt at 14.0 TeV all the way from momentum transfer |t| = 0 to |t| ≃ 10 GeV 2. Their measurement will stringently test not only the diffraction and o-exchange descriptions of the original IIFS model, but also the additional valence quark-quark scattering contribution that we find to be dominant for large |t|. Successful quantitative verification of the predicted dsigma/dt will mean that our picture of the nucleon with an outer cloud of qq¯ condensed ground state, an inner core of topological baryonic charge, and a still smaller core of massless valence quarks provides a realistic description of nucleon structure.

  7. Measurement and Simulation of the Variation in Proton-Induced Energy Deposition in Large Silicon Diode Arrays

    NASA Technical Reports Server (NTRS)

    Howe, Christina L.; Weller, Robert A.; Reed, Robert A.; Sierawski, Brian D.; Marshall, Paul W.; Marshall, Cheryl J.; Mendenhall, Marcus H.; Schrimpf, Ronald D.

    2007-01-01

    The proton induced charge deposition in a well characterized silicon P-i-N focal plane array is analyzed with Monte Carlo based simulations. These simulations include all physical processes, together with pile up, to accurately describe the experimental data. Simulation results reveal important high energy events not easily detected through experiment due to low statistics. The effects of each physical mechanism on the device response is shown for a single proton energy as well as a full proton space flux.

  8. Computational studies of a redox-driven proton pump: Cytochrome c oxidase and biological energy transduction

    NASA Astrophysics Data System (ADS)

    Stuchebrukhov, Alexei A.

    2006-03-01

    Cytochrome c oxidase (CcO) is a redox-driven proton pump, an energy converting molecular machine, which reduces atmospheric oxygen to water and couples the oxygen reduction reaction to the creation of a membrane proton gradient. The proton gradient subsequently drives the synthesis of ATP. The structure of the enzyme has been solved; however, the molecular mechanism of proton pumping is still poorly understood. The correlated electron and proton transport plays a crucial role in the function of the enzyme. Our computer simulations -- combined ab initio and classical, MD and MC- indicate a possible mechanism of CcO. We find that one of the His ligands of the catalytic site, and certain chains of water molecules inside of the enzyme play a crucial role. In this presentation, computational and experimental studies directed toward understanding the mechanism of cytochrome c oxidase will be discussed. D.M. Popovic and A.A. Stuchebrukhov, Proton pumping mechanism and catalytic cycle of cytochrome c oxidase: Coulomb pump model with kinetic gating, FEBS Lett. 2004.

  9. Laser-Produced and Accelerated High Energy Protons

    NASA Astrophysics Data System (ADS)

    Cowan, Thomas

    2005-04-01

    Ultra-low emittance, multi-MeV proton beams have recently been produced by the interaction of high-intensity short-pulse lasers with thin metallic foils [1]. The acceleration process proceeds in two steps. First the laser ponderomotively accelerates huge, MA currents of ˜MeV electrons which propagate through the foil and form a dense relativistic electron sheath on the non-irradiated rear surface. This sheath produces an electrostatic field >10^12 V/m that ionizes the surface atoms almost instantaneously, forming a ˜1 nm thick ion layer which, together with the electron sheath, resembles a virtual cathode. The ions are accelerated initially normal to the foil surface, followed by a diverging plasma expansion phase driven by the electron plasma pressure. By structuring the rear surface of the foil, we have succeeded to produce modulations in the transverse phase space of the ions, which resemble fiducial ``beamlets'' within the envelope of the expanding plasma. This allows one to image the initial accelerating sheath, and map the plasma expansion of the beam envelope, to fully reconstruct the transverse phase space. We find that for protons of 10 MeV, the normalized transverse rms emittance is less than 0.004 π mm.mrad [1], i.e. 100-fold better than typical RF accelerators and at substantially higher ion currents exceeding 10 kA. Recent results will be reported on stripping the electrons while maintaining the low emittance from experiments at the LULI 100 TW laser, and theoretical estimates of the lowest emittance which can be expected based on ion heating mechanisms during the initial sheath formation and ion acceleration processes, will be presented. [1] T.E. Cowan, J. Fuchs, H. Ruhl et al., Phys. Rev. Lett. 92, 204801 (2004).

  10. The energy source of the interplanetary medium and the heliosphere

    NASA Technical Reports Server (NTRS)

    Parker, Eugene N.

    1987-01-01

    The activity of the interplanetary medium arises from occasional transient outbursts of the active corona and, for the most part, from the interaction of fast and slow streams in the solar wind. The basic driver is the heat input to the corona, both transient and steady. The fast streams issue from coronal holes where the heat input may be Alfven waves with root mean squared (rms) fluid velocities of nearly 100 km/sec or may be wholly or in part the waves refracted into the hole from neighboring active regions. If the latter, then the character of the wind from the coronal hole depends upon the proximity and vigor of active regions, with significant differences between the polar and low altitude solar wind. In any case, there is no observational support for any of these ideas, so that the primary cause of the wind from the Sun, as well as any other similar star is not without mystery. It is to be hoped that ground-based observations together with the input from the Solar Optical Telescope and the International Solar Polar Mission may in time succeed in clearing up some of the basic questions.

  11. Innermost Van Allen Radiation Belt for High Energy Protons at Saturn

    NASA Technical Reports Server (NTRS)

    Cooper, John F.

    2008-01-01

    The high energy proton radiation belts of Saturn are energetically dominated by the source from cosmic ray albedo neutron decay (CRAND), trapping of protons from beta decay of neutrons emitted from galactic cosmic ray nuclear interactions with the main rings. These belts were originally discovered in wide gaps between the A-ring, Janus/Epimetheus, Mimas, and Enceladus. The narrow F and G rings significant affected the CRAND protons but did not produce total depletion. Voyager 2 measurements subsequently revealed an outermost CRAND proton belt beyond Enceladus. Although the source rate is small, the trapping times limited by radial magnetospheric diffusion are very long, about ten years at peak measured flux inwards of the G ring, so large fluxes can accumulate unless otherwise limited in the trapping region by neutral gas, dust, and ring body interactions. One proposed final extension of the Cassini Orbiter mission would place perikrone in a 3000-km gap between the inner D ring and the upper atmosphere of Saturn. Experience with CRAND in the Earth's inner Van Allen proton belt suggests that a similar innermost belt might be found in this comparably wide region at Saturn. Radial dependence of magnetospheric diffusion, proximity to the ring neutron source, and northward magnetic offset of Saturn's magnetic equator from the ring plane could potentially produce peak fluxes several orders of magnitude higher than previously measured outside the main rings. Even brief passes through such an intense environment of highly penetrating protons would be a significant concern for spacecraft operations and science observations. Actual fluxes are limited by losses in Saturn's exospheric gas and in a dust environment likely comparable to that of the known CRAND proton belts. The first numerical model of this unexplored radiation belt is presented to determine limits on peak magnitude and radial profile of the proton flux distribution.

  12. ABSOLUTE MEASUREMENT OF THE POLARIZATION OF HIGH ENERGY PROTON BEAMS AT RHIC

    SciTech Connect

    MAKDISI,Y.; BRAVAR, A. BUNCE, G. GILL, R.; HUANG, H.; ET AL.

    2007-06-25

    The spin physics program at the Relativistic Heavy Ion Collider (RHIC) requires knowledge of the beam polarization to better than 5%. Such a goal is made the more difficult by the lack of knowledge of the analyzing power of high energy nuclear physics processes. To overcome this, a polarized hydrogen jet target was constructed and installed at one intersection region in RHIC where it intersects both beams and utilizes the precise knowledge of the jet atomic hydrogen beam polarization to measure the analyzing power in proton-proton elastic scattering in the Nuclear Coulomb Interference (CNI) region at the prescribed RHIC proton beam energy. The reverse reaction is used to assess the absolute beam polarization. Simultaneous measurements taken with fast high statistics polarimeters that measure the p-Carbon elastic scattering process also in the CNI region use the jet results to calibrate the latter.

  13. Criticality of Low-Energy Protons in Single-Event Effects Testing of Highly-Scaled Technologies

    NASA Technical Reports Server (NTRS)

    Pellish, Jonathan A.; Marshall, Paul W.; Rodbell, Kenneth P.; Gordon, Michael S.; LaBel, Kenneth A.; Schwank, James R.; Dodds, Nathaniel A.; Castaneda, Carlos M.; Berg, Melanie D.; Kim, Hak S.; Phan, Anthony M.; Seidleck, Christina M.

    2014-01-01

    We report low-energy proton and low-energy alpha particle single-event effects (SEE) data on a 32 nm silicon-on-insulator (SOI) complementary metal oxide semiconductor (CMOS) latches and static random access memory (SRAM) that demonstrates the criticality of using low-energy protons for SEE testing of highly-scaled technologies. Low-energy protons produced a significantly higher fraction of multi-bit upsets relative to single-bit upsets when compared to similar alpha particle data. This difference highlights the importance of performing hardness assurance testing with protons that include energy distribution components below 2 megaelectron-volt. The importance of low-energy protons to system-level single-event performance is based on the technology under investigation as well as the target radiation environment.

  14. Proton response of CEPA4: A novel LaBr3(Ce)-LaCl3(Ce) phoswich array for high-energy gamma and proton spectroscopy

    NASA Astrophysics Data System (ADS)

    Nácher, E.; Mårtensson, M.; Tengblad, O.; Álvarez-Pol, H.; Bendel, M.; Cortina-Gil, D.; Gernhäuser, R.; Le Bleis, T.; Maj, A.; Nilsson, T.; Perea, A.; Pietras, B.; Ribeiro, G.; Sánchez del Río, J.; Sánchez Rosado, J.; Heinz, A.; Szpak, B.; Winkel, M.; Zieblinski, M.

    2015-01-01

    A new phoswich array, for the detection of high-energy protons and gamma rays from nuclear reactions, has been built. This new detector consists of four individual closely packed scintillator detectors, each of them made of 4 cm of LaBr3(Ce) and 6 cm of LaCl3(Ce) in phoswich configuration (optically coupled and with a common readout). In this paper we report on the results of a beam test performed at the Bronowice Cyclotron Centre (CCB) in Krakow, showing the response of this versatile instrument to high energy protons (70-230 MeV). Furthermore, for the first time we prove that we can reconstruct the original energy of fast protons (E > 200 MeV) which pass through the total length of the crystal while still retaining a good energy resolution.

  15. Investigations of proton beam energy of the MC-50 cyclotron at KIRAMS

    NASA Astrophysics Data System (ADS)

    Khandaker, Mayeen Uddin; Kim, Guinyun; Kim, Kwangsoo; Bin Abu Kassim, Hasan; Nikouravan, Bijan

    2011-07-01

    The accuracy of the measured excitation functions of nuclear reactions largely depend on the precise measurements of the exposed beam energy in activation experiment. We investigated the proton beam energy of the MC-50 cyclotron at the Korea Institute of Radiological and Medical Sciences (KIRAMS) employing the method natCu(p,xn)62Zn / natCu(p,xn)65Zn together with a stacked-foil activation technique. The beam energy along with the stacked samples was also theoretically calculated using computer program SRIM-2003. The measured beam energy showed generally a good agreement with the calculated ones, and this fact demonstrated that the energy (<30 MeV) of the proton beam could be determined by irradiating thin metallic Cu foil target with natural isotopic compositions. Hence, this may be considered as a useful technique for beam monitoring purposes in activation experiment.

  16. Propagation anisotropies of solar flare protons and electrons at low energies in interplanetary space.

    NASA Technical Reports Server (NTRS)

    Pyle, K. R.

    1973-01-01

    Flux anisotropies in interplanetary space were investigated for protons with E greater than 0.66 MeV and electrons with E greater than 400 keV. Data were taken from the University of Chicago charged-particle telescope aboard the deep-space probe Pioneer 7 and from the Goddard Space Flight Center magnetometer aboard the same spacecraft. Flux anisotropies lying to the east of the average interplanetary magnetic field direction were first reported by McCracken et al. (1971), late in a solar particle event, for proton energies greater than 7.5 MeV. This work extends this investigation to much lower proton energies, studies the proton and electron anisotropies during both early and late phases of a particle event, and makes use of detailed magnetic field data. The investigation consists of two parts, a study of many periods taken at random during solar events, for both protons and electrons, and a detailed analysis of one period, early in an event, during which the magnetic field was near the solar direction.

  17. Low energy proton radiation damage to (AlGa)As-GaAs solar cells

    NASA Technical Reports Server (NTRS)

    Loo, R.; Kamath, S.; Knechtli, R. C.

    1979-01-01

    Twenty-seven 2 times 2 sq cm (AlGa)As-GaAs solar cells were fabricated and subjected to 50 keV, 100 keV, and 290 keV of proton irradiation along with eighteen high efficiency silicon solar cells. The results of the study further corroborate the advantages for space missions offered by GaAs cells over state of the art silicon cells. Thus, even though the GaAs cells showed greater degradation when irradiated by protons with energy less than 5 MeV, the solar cells were normally protected from these protons by the glass covers used in space arrays. The GaAs cells also offered superior end of life power capability compared with silicon. The change in the open circuit voltage, short circuit current, spectral response, and dark 1-5 characteristics after irradiation at each proton energy and fluence were found to be consistent with the explanation of the effect of the protons. Also dark 1-5 characteristics showed that a new recombination center dominates the current transport mechanism after irradiation.

  18. Criticality of Low-Energy Protons in Single-Event Effects Testing of Highly-Scaled Technologies

    NASA Technical Reports Server (NTRS)

    Pellish, Jonathan Allen; Marshall, Paul W.; Rodbell, K. P.; Gordon, M. S.; LaBel, K. A.; Schwank, J. R.; Dodds, N. A.; Castaneda, C. M.; Berg, M. D.; Kim, H. S.; Phan, A. M.; Seidleck, C. M.

    2014-01-01

    We report low-energy proton and alpha particle SEE data on a 32 nm silicon-on-insulator (SOI) complementary metal oxide semiconductor (CMOS) static random access memory (SRAM) that demonstrates the criticality of understanding and using low-energy protons for SEE testing of highly-scaled technologies

  19. Bibliographic survey of medium energy inclusive reaction data

    SciTech Connect

    Arthur, E.D.; Madland, D.G.; McClellan, D.M.

    1986-04-01

    A bibliographic survey of inclusive reaction data (experimental and theoretical) for several projectile types having energies between 50 and 1000 MeV has been completed. Approximately one thousand references selected from this survey describe the current state of knowledge for particle-induced inclusive reaction data. The search covered data for the following projectiles: p, d, t, /sup 3/He, /sup 4/He, and lithium ions.

  20. An Overview of the Electron-Proton and High Energy Telescopes for Solar Orbiter

    NASA Astrophysics Data System (ADS)

    Boden, Sebastian; Kulkarni, Shrinivasrao R.; Tammen, Jan; Steinhagen, Jan; Martin, César; Wimmer-Schweingruber, Robert F.; Böttcher, Stephan I.; Seimetz, Lars; Ravanbakhsh, Ali; Elftmann, Robert; Rodriguez-Pacheco, Javier; Prieto Mateo, Manuel; Gomez Herrero, Rául

    2014-05-01

    The Energetic Particle Detector (EPD) suite for ESA's Solar Orbiter will provide key measurements to address particle acceleration at and near the Sun. The EPD suite consists of four sensors (STEP, SIS, EPT, and HET). The University of Kiel in Germany is responsible for the design, development, and building of STEP, EPT and HET. This poster will focus on the last two. The Electron Proton Telescope (EPT) is designed to cleanly separate and measure electrons in the energy range from 20 - 400 keV and protons from 20 - 7000 keV. To separate electrons and protons EPT relies on the magnet/foil-technique. EPT is intended to close the gap between the supra-thermal particles measured by STEP and the high energy range covered by HET. The High-Energy Telescope (HET) will measure electrons from 300 keV up to about 30 MeV, protons from 10 to 100 MeV, and heavy ions from ~20 to 200 MeV/nuc. To achieve this performance HET consists of a series of silicon detectors in a telescope configuration with a scintillator calorimeter to stop high energy protons and ions. It uses the dE/dx vs. total E technique . In this way HET covers an energy range which is of interest for studies of the space radiation environment and will perform measurements needed to understand the origin of high-energy particle events at the Sun. EPT and HET share a common Electronics Box, there are two EPT-HET sensors on Solar Orbiter to allow rudimentary pitch-angle coverage. Here we present the current development status of EPT-HET units and calibration results of demonstration models as well as plans for future activities.

  1. An Overview of Electron-Proton and High Energy Telescopes of Solar Orbiter

    NASA Astrophysics Data System (ADS)

    Kulkarni, S. R.; Grunau, J.; Boden, S.; Steinhagen, J.; Martin, C.; Wimmer-Schweingruber, R. F.; Boettcher, S.; Seimetz, L.; Ravanbakhsh, A.; Elftmann, R.; Rodriguez-Pacheco, J.; Prieto, M.; Gomez-Herrero, R.

    2013-12-01

    The Energetic Particle Detector (EPD) suite for ESA's Solar Orbiter will provide key measurements to address particle acceleration at and near the Sun. The EPD suite consists of five sensors (STEP, SIS, EPT, and HET). The University of Kiel in Germany is also responsible for the design, development, and build of EPT and HET which are presented here. The Electron Proton Telescope (EPT) is designed to cleanly separate and measure electrons in the energy range from 20 - 400 keV and protons from 20 - 7000 keV. The Solar Orbiter EPT electron measurements from 20 - 400 keV will cover the gap with some overlap between suprathermal electrons measured by STEP and high energy electrons measured by HET. The proton measurements from 20 -7000 keV will partially cover the gap between STEP and HET. The Electron and Proton Telescope relies on the magnet/foil-technique. The High-Energy Telescope (HET) on ESA's Solar Orbiter mission, will measure electrons from 300 keV up to about 30 MeV, protons from 10 -100 MeV, and heavy ions from ~20 to 200 MeV/nuc. Thus, HET covers the energy range which is of specific interest for studies of the space environment and will perform the measurements needed to understand the origin of high-energy events at the Sun which occasionally accelerate particles to such high energies that they can penetrate the Earth's atmosphere and be measured at ground level. Here we present the current development status of EPT-HET units and calibration results of demonstration models and present plans for future activities.

  2. Response investigations of a TEPC in high energy proton and neutron beams using the variance method.

    PubMed

    Kyllönen, J E; Grindborg, J E; Lindborg, L

    2002-01-01

    Results from measurements in proton and neutron beams between 68 and 174 MeV at the T. Svedberg Laboratory in Uppsala are presented. The result indicate that a TEPC might underestimate the high-energy contribution to H*(10) in cosmic radiation applications such as measurements onboard aircraft.

  3. The kinetic energy spectrum of protons produced by the dissociative ionization of H2 by electron impact

    NASA Technical Reports Server (NTRS)

    Khakoo, M. A.; Srivastava, S. K.

    1985-01-01

    The kinetic energy spectra of protons resulting from the dissociative ionization of H2 by electron impact have been measured for electron impact energies from threshold (approximately 17 eV) to 160 eV at 90 deg and 30 deg detection angles, using a crossed-beam experimental arrangement. To check reliability, two separate proton energy analysis methods have been employed, i.e., a time-of-flight proton energy analysis and an electrostatic hemispherical energy analyzer. The present results are compared with previous measurements.

  4. Can the Abraham Light Momentum and Energy in a Medium Constitute a Lorentz Four-Vector?

    NASA Astrophysics Data System (ADS)

    Wang, Changbiao

    2013-08-01

    By analyzing the Einstein-box thought experiment with the principle of relativity, it is shown that Abraham's light momentum and energy in a medium cannot constitute a Lorentz four-vector, and they consequentially break global momentum and energy conservation laws. In contrast, Minkowski's momentum and energy always constitute a Lorentz four-vector no matter whether in a medium or in vacuum, and the Minkowski's momentum is the unique correct light momentum. A momentum-associated photon mass in a medium is exposed, which explains why only the Abraham's momentum is derived in the traditional "center-of-mass-energy" approach. The EM boundary-condition matching approach, combined with Einstein light-quantum hypothesis, is proposed to analyze this thought experiment, and it is found for the first time that only from Maxwell equations without resort to the relativity, the correctness of light momentum definitions cannot be identified. Optical pulling effect is studied as well.

  5. Attainment of Electron Beam Suitable for Medium Energy Electron Cooling

    SciTech Connect

    Seletskiy, Sergei M.

    2005-01-01

    Electron cooling of charged particle beams is a well-established technique at electron energies of up to 300 keV. However, up to the present time the advance of electron cooling to the MeV-range energies has remained a purely theoretical possibility. The electron cooling project at Fermilab has recently demonstrated the ¯rst cooling of 8.9 GeV/c antiprotons in the Recycler ring, and therefore, has proved the validity of the idea of relativistic electron cool- ing. The Recycler Electron Cooler (REC) is the key component of the Teva- tron Run II luminosity upgrade project. Its performance depends critically on the quality of electron beam. A stable electron beam of 4.3 MeV car- rying 0.5 A of DC current is required. The beam suitable for the Recycler Electron Cooler must have an angular spread not exceeding 200 ¹rad. The full-scale prototype of the REC was designed, built and tested at Fermilab in the Wideband laboratory to study the feasibility of attaining the high-quality electron beam. In this thesis I describe various aspects of development of the Fermilab electron cooling system, and the techniques used to obtain the electron beam suitable for the cooling process. In particular I emphasize those aspects of the work for which I was principally responsible.

  6. Centrality-dependent forward J/ψ production in high energy proton-nucleus collisions

    NASA Astrophysics Data System (ADS)

    Ducloué, B.; Lappi, T.; Mäntysaari, H.

    2016-03-01

    Forward J/ψ production and suppression in high energy proton-nucleus collisions can be an important probe of gluon saturation. In an earlier work we studied this process in the Color Glass Condensate framework and showed that using the Glauber approach to extrapolate the dipole cross section of a proton to a nucleus leads to results closer to experimental data than previous calculations in this framework. Here we investigate the centrality dependence of the nuclear suppression in this model and show a comparison of our results with recent LHC data.

  7. PIXE-induced XRF by high energy protons and alpha particles

    NASA Astrophysics Data System (ADS)

    Castiglioni, M.; Manfredi, G.; Milazzo, M.; Silari, M.

    1993-04-01

    In the past three years a comprehensive theoretical and experimental study has been conducted on the production of intense sources of monochromatic X-rays in the range 1-75 keV by bombardment of pure element targets with protons and alpha particles of tens of MeV energy. The present paper describes a dual-chamber irradiation system which has been designed and built for PIXE-induced XRF. Preliminary experimental results of analyses obtained with 20 MeV protons and a Zn primary target are shown.

  8. Thermodynamic view of activation energies of proton transfer in various gramicidin A channels.

    PubMed

    Chernyshev, Anatoly; Cukierman, Samuel

    2002-01-01

    The temperature dependencies (range: 5-45 degrees C) of single-channel proton conductances (g(H)) in native gramicidin A (gA) and in two diastereoisomers (SS and RR) of the dioxolane-linked gA channels were measured in glycerylmonooleate/decane (GMO) and diphytanoylphosphatidylcholine/decane (DiPhPC) bilayers. Linear Arrhenius plots (ln (g(H)) versus K(-1)) were obtained for the native gA and RR channels in both types of bilayers, and for the SS channel in GMO bilayers only. The Arrhenius plot for proton transfer in the SS channel in DiPhPC bilayers had a break in linearity around 20 degrees C. This break seems to occur only when protons are the permeating cations in the SS channel. The activation energies (E(a)) for proton transfer in various gA channels (approximately 15 kJ/mol) are consistent with the rate-limiting step being in the channel and/or at the membrane-channel/solution interface, and not in bulk solution. E(a) values for proton transfer in gA channels are considerably smaller than for the permeation of nonproton currents in gA as well as in various other ion channels. The E(a) values for proton transfer in native gA channels are nearly the same in both GMO and DiPhPC bilayers. In contrast, for the dioxolane linked gA dimers, E(a) values were strongly modulated by the lipid environment. The Gibbs activation free energies (Delta G(#)(o)) for protons in various gA channels are within the range of 27-29 kJ/mol in GMO bilayers and of 20-22 kJ/mol in DiPhPC bilayers. The largest difference between Delta G(#)(o) for proton currents occurs between native gA (or SS channels) and the RR channel. In general, the activation entropy (Delta S) is mostly responsible for the differences between g(H) values in various gA channels, and also in distinct bilayers. However, significant differences between the activation enthalpies (Delta H(#)(o)) for proton transfer in the SS and RR channels occur in distinct membranes.

  9. Intermediate energy proton stopping power for hydrogen molecules and monoatomic helium gas

    NASA Technical Reports Server (NTRS)

    Xu, Y. J.; Khandelwal, G. S.; Wilson, J. W.

    1984-01-01

    Stopping power in the intermediate energy region (100 keV to 1 MeV) was investigated, based on the work of Lindhard and Winther, and on the local plasma model. The theory is applied to calculate stopping power of hydrogen molecules and helium gas for protons of energy ranging from 100 keV to 2.5 MeV. Agreement with the experimental data is found to be within 10 percent.

  10. LDEF (Prelaunch), M0002-01 : Trapped-Proton Energy Spectrum Determination, Tray G12

    NASA Technical Reports Server (NTRS)

    1984-01-01

    The prelaunch photograph was taken in SAEF II at KSC prior to installation of the integrated tray on the LDEF. The Trapped Proton Energy Spectrum Determination Experiment is one of four (4) experiments located in a three (3) inch deep LDEF end center tray. Additional Trapped Proton Energy Experiments are located in peripheral LDEF integrated experiment trays in the D03 and D09 tray locations. The identifica tion plate on the lower right corner of the experiment mounting plate identifies the experiments location and orientation in the experiment tray. The Trapped Proton Energy experiment, located in the upper left quadrant of the integrated tray, consist of a primary experiment and three (3) sub experiments mounted on an aluminum mount ing plate. The primary experiment components include six (6) stacks of CR-39 passive detectors in individual aluminum housings and an aluminum mounting structure, configured to provide the desired exposure for the detector stacks. The secondary experiments consist of the Neutron and Proton Activation experiment that expose metal samples to the ambient flux throughout the mis sion, the Microsphere Dosimetry experiment housed in a cylindrical aluminum container and the Flux Measurement by Ion Trapping experiment consisting of a variety of sample materials that are exposed to the space environment for the total mission. The exterior surfaces of the mounting plate, the experiment housings and the support structure are coated with IITRI S13G-LO white paint.The experiment is assembled using non-magnetic stainless steel fasteners and safety wire.

  11. The contribution of low-energy protons to the total on-orbit SEU rate

    SciTech Connect

    Dodds, Nathaniel Anson; Martinez, Marino J.; Dodd, Paul E.; Shaneyfelt, Marty R.; Sexton, Frederick W.; Black, Jeffrey D.; Lee, David S.; Swanson, Scot E.; Bhuva, B. L.; Warren, K. M.; Reed, R. A.; Trippe, J.; Sierawski, B. D.; Weller, R. A.; Mahatme, N.; Gaspard, N.; Assis, T.; Austin, R.; Massengill, L. M.; Swift, G.; Wirthlin, M.; Cannon, M.; Liu, R.; Chen, L.; Kelly, A. T.; Marshall, P.; Trinczek, M.; Blackmore, E. W.; Wen, S. -J.; Wong, R.; Narasimham, B.; Pellish, J. A.; Puchner, H.; Weeden-Wright, S. L.

    2015-11-10

    Low- and high-energy proton experimental data and error rate predictions are presented for many bulk Si and SOI circuits from the 20-90 nm technology nodes to quantify how much low-energy protons (LEPs) can contribute to the total on-orbit single-event upset (SEU) rate. Every effort was made to predict LEP error rates that are conservatively high; even secondary protons generated in the spacecraft shielding have been included in the analysis. Across all the environments and circuits investigated, and when operating within 10% of the nominal operating voltage, LEPs were found to increase the total SEU rate to up to 4.3 times as high as it would have been in the absence of LEPs. Therefore, the best approach to account for LEP effects may be to calculate the total error rate from high-energy protons and heavy ions, and then multiply it by a safety margin of 5. If that error rate can be tolerated then our findings suggest that it is justified to waive LEP tests in certain situations. Trends were observed in the LEP angular responses of the circuits tested. As a result, grazing angles were the worst case for the SOI circuits, whereas the worst-case angle was at or near normal incidence for the bulk circuits.

  12. Energy Loss of High Intensity Focused Proton Beams Penetrating Metal Foils

    NASA Astrophysics Data System (ADS)

    McGuffey, C.; Qiao, B.; Kim, J.; Beg, F. N.; Wei, M. S.; Evans, M.; Fitzsimmons, P.; Stephens, R. B.; Chen, S. N.; Fuchs, J.; Nilson, P. M.; Canning, D.; Mastrosimone, D.; Foord, M. E.

    2014-10-01

    Shortpulse-laser-driven intense ion beams are appealing for applications in probing and creating high energy density plasmas. Such a beam isochorically heats and rapidly ionizes any target it enters into warm dense matter with uncertain transport and stopping properties. Here we present experimental measurements taken with the 1.25 kJ, 10 ps OMEGA EP BL shortpulse laser of the proton and carbon spectra after passing through metal foils. The laser irradiated spherically curved C targets with intensity 4×1018 W/cm2, producing proton beams with 3 MeV slope temperature and a sharp low energy cutoff at 5 MeV which has not been observed on lower energy, shorter pulse intense lasers. The beam either diverged freely or was focused to estimated 1016 p +/cm2 ps by a surrounding structure before entering the metal foils (Al or Ag and a Cu tracer layer). The proton and ion spectra were altered by the foil depending on material and whether or not the beam was focused. Transverse proton radiography probed the target with ps temporal and 10 micron spatial resolution, indicating an electrostatic field on the foil may also have affected the beam. We present complementary particle-in-cell simulations of the beam generation and transport to the foils. This work was supported by the DOE/NNSA National Laser User Facility program, Contract DE-SC0001265.

  13. High Energy Proton Ejection from Hydrocarbon Molecules Driven by Highly Efficient Field Ionization

    NASA Astrophysics Data System (ADS)

    Roither, S.; Xie, X.; Kartashov, D.; Zhang, L.; Schöffler, M.; Xu, H.; Iwasaki, A.; Okino, T.; Yamanouchi, K.; Baltuška, A.; Kitzler, M.

    We report on the ejection of protons with surprisingly high kinetic energies up to 60 eV from a series of polyatomic hydrocarbon molecules exposed to Titanium-Sapphire laser pulses with moderate laser peak intensities of a few 1014 W/cm2. Using multi-particle coincidence imaging we are able to decompose the observed proton energy spectra into the contributions of individual fragmentation channels. It is shown that the molecules can completely fragment into bare atomic ions already at relatively low peak intensities, and that the protons are ejected in a concerted Coulomb explosion from unexpectedly high charge states. We propose that a thus far undescribed process, namely that enhanced ionization (EI) taking place at all C-H bonds in parallel, is responsible for the high charge states and high proton energies. The proposition is successfully tested by using (stretched) few-cycle pulses with a bandwidth limited duration as short as 4.3 fs, for which the C-H nuclear motion is too slow to reach the critical internuclear distance for EI.

  14. The contribution of low-energy protons to the total on-orbit SEU rate

    DOE PAGES

    Dodds, Nathaniel Anson; Martinez, Marino J.; Dodd, Paul E.; Shaneyfelt, Marty R.; Sexton, Frederick W.; Black, Jeffrey D.; Lee, David S.; Swanson, Scot E.; Bhuva, B. L.; Warren, K. M.; et al

    2015-11-10

    Low- and high-energy proton experimental data and error rate predictions are presented for many bulk Si and SOI circuits from the 20-90 nm technology nodes to quantify how much low-energy protons (LEPs) can contribute to the total on-orbit single-event upset (SEU) rate. Every effort was made to predict LEP error rates that are conservatively high; even secondary protons generated in the spacecraft shielding have been included in the analysis. Across all the environments and circuits investigated, and when operating within 10% of the nominal operating voltage, LEPs were found to increase the total SEU rate to up to 4.3 timesmore » as high as it would have been in the absence of LEPs. Therefore, the best approach to account for LEP effects may be to calculate the total error rate from high-energy protons and heavy ions, and then multiply it by a safety margin of 5. If that error rate can be tolerated then our findings suggest that it is justified to waive LEP tests in certain situations. Trends were observed in the LEP angular responses of the circuits tested. As a result, grazing angles were the worst case for the SOI circuits, whereas the worst-case angle was at or near normal incidence for the bulk circuits.« less

  15. Comparison of MCNPX and Geant4 proton energy deposition predictions for clinical use

    PubMed Central

    Titt, U.; Bednarz, B.; Paganetti, H.

    2012-01-01

    Several different Monte Carlo codes are currently being used at proton therapy centers to improve upon dose predictions over standard methods using analytical or semi-empirical dose algorithms. There is a need to better ascertain the differences between proton dose predictions from different available Monte Carlo codes. In this investigation Geant4 and MCNPX, the two most-utilized Monte Carlo codes for proton therapy applications, were used to predict energy deposition distributions in a variety of geometries, comprising simple water phantoms, water phantoms with complex inserts and in a voxelized geometry based on clinical CT data. The gamma analysis was used to evaluate the differences of the predictions between the codes. The results show that in the all cases the agreement was better than clinical acceptance criteria. PMID:22996039

  16. Solar Modulation of Low-Energy Antiproton and Proton Spectra Measured by BESS

    NASA Technical Reports Server (NTRS)

    Mitchell, John W.; Abe, Ko; Fuke, Hideyuki; Haino, Sadakazu; Hams, Thomas; Horikoshi, Atsushi; Kim, Ki-Chun; Lee, MooHyun; Makida, Yashuhiro; Matsuda, Shinya; Moiseev, Alexander; Nishimura, Jun; Nozaki, Mitsuaki

    2007-01-01

    The spectra of low-energy cosmic-ray protons and antiprotons have been measured by BESS in nine high-latitude balloon flights between 1993 and 2004. These measurements span a range of solar activity from the previous solar minimum through solar ma>:im%am and the onset of the present solar minimum, as well as a solar magnetic field reversal from positive to negative in 2000. Because protons and antiprotons differ only in charge sign, these simultaneous measurements provide a sensitive probe of charge dependent solar modulation. The antiproton to proton ratio measured by BESS is consistent with simple spherically symmetric models of solar modulation during the Sun's positive polarity phase, but favor charge-sign-dependent drift models during the negative phase. The BESS measurements will be presented and compared to various models of solar modulation.

  17. Longitudinal scaling of net-protons in AuAu and pp collisions at RHIC energies

    NASA Astrophysics Data System (ADS)

    Videbaek, Flemming

    2008-10-01

    BRAHMS has studied net-protons distributions in Au+Au and p+p collisions at √sNN=62.4 and 200 GeV. Net-proton distributions reflect the net-baryon yields and can be used to extract the nuclear stopping in the collisions, thus providing information on baryon number transport and energy available for particle production. The talk will present final and preliminary results from the above mentioned systems. It will be shown that in p+p and in Au+Au central collisions that net-proton distributions exhibit longitudinal scaling once the target contribution to the projectile rapidity range is corrected for. The difference between p+p and Au+Au will be discussed. Aspects of future measurements at the LHC of net-baryons at mid-rapidity will be brought forth.

  18. Simultaneous measurements of absorbed dose and linear energy transfer in therapeutic proton beams.

    PubMed

    Granville, Dal A; Sahoo, Narayan; Sawakuchi, Gabriel O

    2016-02-21

    The biological response resulting from proton therapy depends on both the absorbed dose in the irradiated tissue and the linear energy transfer (LET) of the beam. Currently, optimization of proton therapy treatment plans is based only on absorbed dose. However, recent advances in proton therapy delivery have made it possible to vary the LET distribution for potential therapeutic gain, leading to investigations of using LET as an additional parameter in plan optimization. Having a method to measure and verify both absorbed dose and LET as part of a quality assurance program would be ideal for the safe delivery of such plans. Here we demonstrated the potential of an optically stimulated luminescence (OSL) technique to simultaneously measure absorbed dose and LET. We calibrated the ratio of ultraviolet (UV) to blue emission intensities from Al2O3:C OSL detectors as a function of LET to facilitate LET measurements. We also calibrated the intensity of the blue OSL emission for absorbed dose measurements and introduced a technique to correct for the LET-dependent dose response of OSL detectors exposed to therapeutic proton beams. We demonstrated the potential of our OSL technique by using it to measure LET and absorbed dose under new irradiation conditions, including patient-specific proton therapy treatment plans. In the beams investigated, we found the OSL technique to measure dose-weighted LET within 7.9% of Monte Carlo-simulated values and absorbed dose within 2.5% of ionization chamber measurements.

  19. Simultaneous measurements of absorbed dose and linear energy transfer in therapeutic proton beams.

    PubMed

    Granville, Dal A; Sahoo, Narayan; Sawakuchi, Gabriel O

    2016-02-21

    The biological response resulting from proton therapy depends on both the absorbed dose in the irradiated tissue and the linear energy transfer (LET) of the beam. Currently, optimization of proton therapy treatment plans is based only on absorbed dose. However, recent advances in proton therapy delivery have made it possible to vary the LET distribution for potential therapeutic gain, leading to investigations of using LET as an additional parameter in plan optimization. Having a method to measure and verify both absorbed dose and LET as part of a quality assurance program would be ideal for the safe delivery of such plans. Here we demonstrated the potential of an optically stimulated luminescence (OSL) technique to simultaneously measure absorbed dose and LET. We calibrated the ratio of ultraviolet (UV) to blue emission intensities from Al2O3:C OSL detectors as a function of LET to facilitate LET measurements. We also calibrated the intensity of the blue OSL emission for absorbed dose measurements and introduced a technique to correct for the LET-dependent dose response of OSL detectors exposed to therapeutic proton beams. We demonstrated the potential of our OSL technique by using it to measure LET and absorbed dose under new irradiation conditions, including patient-specific proton therapy treatment plans. In the beams investigated, we found the OSL technique to measure dose-weighted LET within 7.9% of Monte Carlo-simulated values and absorbed dose within 2.5% of ionization chamber measurements. PMID:26859539

  20. The effect of stochastic re-acceleration on the energy spectrum of shock-accelerated protons

    SciTech Connect

    Afanasiev, Alexandr; Vainio, Rami; Kocharov, Leon

    2014-07-20

    The energy spectra of particles in gradual solar energetic particle (SEP) events do not always have a power-law form attributed to the diffusive shock acceleration mechanism. In particular, the observed spectra in major SEP events can take the form of a broken (double) power law. In this paper, we study the effect of a process that can modify the power-law spectral form produced by the diffusive shock acceleration: the stochastic re-acceleration of energetic protons by enhanced Alfvénic turbulence in the downstream region of a shock wave. There are arguments suggesting that this process can be important when the shock propagates in the corona. We consider a coronal magnetic loop traversed by a shock and perform Monte Carlo simulations of interactions of shock-accelerated protons with Alfvén waves in the loop. The wave-particle interactions are treated self-consistently, so the finiteness of the available turbulent energy is taken into account. The initial energy spectrum of particles is taken to be a power law. The simulations reveal that the stochastic re-acceleration leads either to the formation of a spectrum that is described in a wide energy range by a power law (although the resulting power-law index is different from the initial one) or to a broken power-law spectrum. The resulting spectral form is determined by the ratio of the energy density of shock-accelerated protons to the wave energy density in the shock's downstream region.

  1. Proton and hydride transfers in solution: hybrid QMmm/MM free energy perturbation study

    SciTech Connect

    Ho, L. Lawrence |; Bash, P.A.; Kerell, A.D., Jr

    1996-03-01

    A hybrid quantum and molecular mechanical (QM/MM) free energy perturbation (FEP) method is implemented in the context of molecular dynamics (MD). The semiempirical quantum mechanical (QM) Hamiltonian (Austin Model 1) represents solute molecules, and the molecular mechanical (MM) CHARMM force field describes the water solvent. The QM/MM FEP method is used to calculate the free energy changes in aqueous solution for (1) a proton transfer from methanol to imidazole and (2) a hydride transfer from methoxide to nicotinamide. The QM/MM interaction energies between the solute and solvent arc calibrated to emulate the solute-solvent interaction energies determined at the Hartee-Fock 6-31G(d) level of ab initio theory. The free energy changes for the proton and hydride transfers are calculated to be 15.1 and {minus}6.3 kcal/mol, respectively, which compare favorably with the corresponding experimental values of 12.9 and {minus}7.4 kcal/mol. An estimate of the reliability of the calculations is obtained through the computation of the forward (15.1 and {minus}6.3 kcal/mol) and backward ({minus}14.1 and 9.1 kcal/mol)free energy changes. The reasonable correspondence between these two independent calculations suggests that adequate phase space sampling is obtained along the reaction pathways chosen to transform the proton and hydride systems between their respective reactant and product states.

  2. Effects of low energy proton, electron, and simultaneously combined proton and electron environments in silicon and GaAs solar cells

    NASA Technical Reports Server (NTRS)

    Horne, W. E.; Day, A. C.; Russell, D. A.

    1980-01-01

    Degradation of silicon and GaAs solar cells due to exposures to low energy proton and electron environments and annealing data for these cells are discussed. Degradation of silicon cells in simultaneously combined electron and low energy proton environments and previous experimental work is summarized and evaluated. The deficiencies in current solar array damage prediction techniques indicated by these data and the relevance of these deficiencies to specific missions such as intermediate altitude orbits and orbital transfer vehicles using solar electric propulsion systems are considered.

  3. Significance of medium-energy gamma-ray astronomy in the study of cosmic rays

    NASA Technical Reports Server (NTRS)

    Fichtel, C. E.; Kniffen, D. A.; Thompson, D. J.; Bignami, G. F.; Cheung, C. Y.

    1976-01-01

    The paper examines the medium-energy (about 10-30 MeV) galactic gamma-ray radiation from primary and secondary electrons and calculates the expected gamma-ray distribution for the specific model of Bignami et al. (1975) on the assumption that the cosmic rays are correlated with the matter on the scale of galactic arms. The energy spectrum typical of regions near the galactic center indicates a dramatic shift from a predominantly cosmic-ray nucleonic mechanism at higher energies to a cosmic-ray electron mechanism at the lower energies. This provides a most important and direct means of probing the cosmic-ray electrons as a function of galactic position by making gamma-ray observations in the few to 40 MeV energy range. Medium-energy gamma-ray astronomy is shown to be a valuable tool in galactic research.

  4. Neutron energy spectrum from 120 GeV protons on a thick copper target

    SciTech Connect

    Shigyo, Nobuhiro; Sanami, Toshiya; Kajimoto, Tsuyoshi; Iwamoto, Yosuke; Hagiwara, Masayuki; Saito, Kiwamu; Ishibashi, Kenji; Nakashima, Hiroshi; Sakamoto, Yukio; Lee, Hee-Seock; Ramberg, Erik; /Fermilab

    2010-08-01

    Neutron energy spectrum from 120 GeV protons on a thick copper target was measured at the Meson Test Beam Facility (MTBF) at Fermi National Accelerator Laboratory. The data allows for evaluation of neutron production process implemented in theoretical simulation codes. It also helps exploring the reasons for some disagreement between calculation results and shielding benchmark data taken at high energy accelerator facilities, since it is evaluated separately from neutron transport. The experiment was carried out using a 120 GeV proton beam of 3E5 protons/spill. Since the spill duration was 4 seconds, protoninduced events were counted pulse by pulse. The intensity was maintained using diffusers and collimators installed in the beam line to MTBF. The protons hit a copper block target the size of which is 5cm x 5cm x 60 cm long. The neutrons produced in the target were measured using NE213 liquid scintillator detectors, placed about 5.5 m away from the target at 30{sup o} and 5 m 90{sup o} with respect to the proton beam axis. The neutron energy was determined by time-of-flight technique using timing difference between the NE213 and a plastic scintillator located just before the target. Neutron detection efficiency of NE213 was determined on basis of experimental data from the high energy neutron beam line at Los Alamos National Laboratory. The neutron spectrum was compared with the results of multiparticle transport codes to validate the implemented theoretical models. The apparatus would be applied to future measurements to obtain a systematic data set for secondary particle production on various target materials.

  5. Energy loss distributions of 7 TeV protons axially channeled in the bent <1 1 0> Si crystal

    NASA Astrophysics Data System (ADS)

    Stojanov, Nace; Petrović, Srdjan

    2016-04-01

    In this article, the energy loss distributions of relativistic protons axially channeled in the bent <1 1 0> Si crystal are studied. The crystal thickness is equal to 1 mm, which corresponds to the reduced crystal thickness, Λ, equal to 1.22, whereas the bending angle, α, was varied from 0 to 30 μrad. The proton energy of 7 TeV was chosen in accordance with the concept of using the bent crystals as a tool for selective deflection of the beam halo particles from the LUA9 experiment at LHC. For the continuum interaction potential of the proton and the crystal the Molière's expression was used and the energy loss of a proton was calculated by applying the trajectory dependent stopping power model. Further, the uncertainness of the scattering angle of the proton caused by its collisions with the electrons of the crystal and the divergence of the proton beam were taken into account. The energy loss distribution of the channeled protons was obtained via the numerical solution of the proton equations of motion in the transverse plane and the computer simulation method. The analysis of the obtained theoretical data shows that the shape of the energy loss distribution strongly depends on the horizontal or vertical direction of the curvature of the crystal. The number of dechanneled protons as a function of the bending angle also strongly depends on the direction of the crystal's curvature. As a result, the dechanneling rates and ranges, obtained from the Gompertz type sigmoidal fitting functions, have different sets of values for different bending orientations. We have also studied the influence of the proton beam divergence on the energy loss distribution of channeled protons.

  6. Proton Nonionizing Energy Loss (NIEL) for Device Applications

    NASA Technical Reports Server (NTRS)

    Jun, Insoo; Xapsos, Michael A.; Messenger, Scott R.; Burke, Edward A.; Walters, Robert J.; Summers, Geoff; Jordan, Thomas

    2003-01-01

    Nonionizing energy loss (NIEL) is a quantity that describes the rate of energy loss due to atomic displacements as a particle traverses a material. The product of the NIEL and the particle fluence (time integrated flux) gives the displacement damage energy deposition per unit mass of material. NIEL plays the same role to the displacement damage energy deposition as the stopping power to the total ionizing dose (TID). The concept of NIEL has been very useful for correlating particle induced displacement damage effects in semiconductor and optical devices. Many studies have successfully demonstrated that the degradation of semiconductor devices or optical sensors in a radiation field can be linearly correlated to the displacement damage energy, and subsequently to the NIEL deposited in the semiconductor devices or optical sensors. In addition, the NIEL concept was also useful in the study of both Si and GaAs solar cells and of high temperature superconductors, and at predicting the survivability of detectors used at the LHC at CERN. On the other hand, there are some instances where discrepancies are observed in the application of NIEL, most notably in GaAs semiconductor devices. However, NIEL is still a valuable tool, and can be used to scale damages produced by different particles and in different environments, even though this is not understood at the microscopic level.

  7. Energy-spilling reactions of Streptococcus bovis and resistance of its membrane to proton conductance.

    PubMed Central

    Cook, G M; Russell, J B

    1994-01-01

    Glucose-excess cultures of Streptococcus bovis consumed glucose faster than the amount that could be explained by growth or maintenance, and nongrowing chloramphenicol-treated cells had a rate of glucose consumption that was 10-fold greater than the maintenance rate. Because N,N-dicyclohexylcarbodiimide, an inhibitor of the membrane-bound F1F0 ATPase, eliminated the nongrowth energy dissipation (energy spilling) without a decrease in ATP and the rate of energy spilling could be increased by the protonophore 3,3',4',5-tetrachlorosalicylanilide, it appeared that a futile cycle of protons through the cell membrane was responsible for most of the energy spilling. When the rate of energy spilling was decreased gradually with iodoacetate, there was only a small decrease in the phosphorylation potential (delta G'p) and the theoretical estimate of H+ per ATP decreased from 4.2 to 3.6. On the bases of this ratio of H+ to ATP and the rate of ATP production, the flux of protons (amperage) across the cell membrane was directly proportional to the rate of energy spilling. Amperage values estimated from delta G'p were, however, nearly twice as great as values which were estimated from the heat production (delta H) of the cells [amperage = (0.38 x wattage)/delta p]. The last comparison indicated that only a fraction of the delta G of ATP hydrolysis was harvested by the F1F0 ATPase to pump protons. Both estimates of amperage indicated that the resistance of the cell membrane to proton conductance was inversely proportional to the log of the energy-spilling rate. PMID:8031089

  8. Study of open charm production in proton+proton collisions at center of mass energies = 200 GeV

    NASA Astrophysics Data System (ADS)

    Butsyk, Sergey

    2005-11-01

    The PHENIX experiment at the Relativistic Heavy Ion Collider (RHIC) with its unique electron identification system enables us to perform high precision measurements of electron yields. By measuring electron production at high transverse momentum, we can disentangle the contribution of electrons originating from semi-leptonic decays of heavy quarks (charm or bottom) from the less interesting "photonic" decay modes of light mesons. D/B mesons carry single heavy valence quarks and are usually referred to as "Open Charm" and "Open Bottom" particles, differentiating them from Closed Flavor particles such as J/psi, and Y mesons. Due to the large mass of the heavy quarks, their production mechanisms can be adequately explained by perturbative QCD (pQCD) theory. This dissertation presents the measurement of electrons from heavy flavor decays in proton + proton collisions at RHIC at collision energy s = 200 GeV over a wide range of transverse moment (0.4 < pT < 5 GeV/c). Two independent analysis techniques of signal extraction were performed. The "Cocktail" subtraction is based on the calculation and subtraction of the expected "photon-related" electron background based upon measured yields of light mesons. The "Converter" subtraction is based upon a direct measurement of photon yields achieved introducing additional material in the PHENIX acceptance and deducing the photon abundance by measuring the increase in electron yield. This is the first measurement of the Open Charm crossection at this collision energy and it is an important baseline measurement for comparison with nucleus + nucleus collisions. The modification of Open Charm production in heavy ion collisions compared to the presented p + p result can be used to study the final state interaction of the heavy quarks with hot dense matter inside the collisions. The results of the Open Charm measurements are compared to current pQCD predictions both in Leading Order (LO) O a2s and Next-to-Leading Order (NLO) O a3s

  9. Stepwise Internal Energy Control for Protonated Methanol Clusters by Using the Inert Gas Tagging

    NASA Astrophysics Data System (ADS)

    Shimamori, Takuto; Kuo, Jer-Lai; Fujii, Asuka

    2016-06-01

    Preferred isomer structures of hydrogen-bonded clusters should depend on their temperature because of the entropy term in the free energy. To observe such temperature dependence, we propose a new approach to control the internal energy (vibrational temperature) of protonated clusters in the gas phase. We performed IR spectroscopy of protonated methanol clusters, H+ (CH{_3}OH) {_n}, n= 5 and 7, with the tagging by various inert gas species (Ar, CO{_2}, CO, CS{_2}, C{_2}H{_2}, and C{_6}H{_6}). We found that vibrational temperature of the tagged clusters raises with increase of the interaction energy with the tag species, and the observed cluster structures follow the theoretical prediction of the temperature dependence of the isomer population.

  10. Tungsten fragmentation in nuclear reactions induced by high-energy cosmic-ray protons

    SciTech Connect

    Chechenin, N. G. Chuvilskaya, T. V.; Shirokova, A. A.; Kadmenskii, A. G.

    2015-01-15

    Tungsten fragmentation arising in nuclear reactions induced by cosmic-ray protons in space-vehicle electronics is considered. In modern technologies of integrated circuits featuring a three-dimensional layered architecture, tungsten is frequently used as a material for interlayer conducting connections. Within the preequilibrium model, tungsten-fragmentation features, including the cross sections for the elastic and inelastic scattering of protons of energy between 30 and 240 MeV; the yields of isotopes and isobars; their energy, charge, and mass distributions; and recoil energy spectra, are calculated on the basis of the TALYS and EMPIRE-II-19 codes. It is shown that tungsten fragmentation affects substantially forecasts of failures of space-vehicle electronics.

  11. First polarized proton collision at a beam energy of 250 GeV in RHIC

    SciTech Connect

    Bai,M.; Ahrens, L.; Alekseev, I. G.; Alessi, J.; et al.

    2009-05-04

    After providing collisions of polarized protons at a beam energy of 100 GeV since 2001, the Relativistic Heavy Ion Collider (RHIC) at BNL had its first opportunity to collide polarized protons at its maximum beam energy of 250 GeV in the 2009 polarized proton operations. Equipped with two full Siberian snakes [1] in each ring, RHIC preserves polarization during acceleration from injection to 100 GeV with precise control of the betatron tunes and vertical orbit distortions. However, the strong intrinsic spin resonances beyond 100 GeV are more than two times stronger than those below 100 GeV, requiring much tighter tolerances on vertical orbit distortions and betatron tunes. With the currently achieved orbit correction and tune control, average polarizations of {approx_equal} 42% at top energy and average polarizations of {approx_equal} 55% at injection energy were achieved. Polarization measurements as a function of beam energy also indicated aU polarization losses occurred around three strong intrinsic resonances at 136 GeV, 199.3 GeV and 220.8 GeV Peak luminosity of 122 x 10{sup 30} cm{sup -2} s{sup -1} was also demonstrated. This paper presents the performance of the first RHIC 250 GeV operation and discusses the depolarization issues encountered during the run.

  12. Feasibility of a medium-size central cogenerated energy facility, energy management memorandum

    NASA Astrophysics Data System (ADS)

    Porter, R. W.

    1982-09-01

    The thermal-economic feasibility was studied of a medium-size central cogenerated energy facility designed to serve five varied industries. Generation options included one dual-fuel diesel and one gas turbine, both with waste heat boilers, and five fired boilers. Fuels included natural gas, and for the fired-boiler cases, also low-sulphur coal and municipal refuse. The fired-boiler cogeneration systems employed back-pressure steam turbines. For coal and refuse, the option of steam only without cogeneration was also assessed. The refuse-fired cases utilized modular incinerators. The options provided for a wide range of steam and electrical capacities. Deficient steam was assumed generated independently in existing equipment. Excess electrical power over that which could be displaced was assumed sold to Commonwealth Edison Company under PURPA (Public Utility Regulator Policies Act). The facility was assumed operated by a mutually owned corporation formed by the cogenerated power users. The economic analysis was predicted on currently applicable energy-investment tax credits and accelerated depreciation for a January 1985 startup date. Based on 100% equity financing, the results indicated that the best alternative was the modular-incinerator cogeneration system.

  13. Neutron-proton effective mass splitting in terms of symmetry energy and its density slope

    SciTech Connect

    Chakraborty, S.; Sahoo, B.; Sahoo, S.

    2015-01-15

    Using a simple density-dependent finite-range effective interaction having Yukawa form, the density dependence of isoscalar and isovector effective masses is studied. The isovector effective mass is found to be different for different pairs of like and unlike nucleons. Using HVH theorem, the neutron-proton effective mass splitting is represented in terms of symmetry energy and its density slope. It is again observed that the neutron-proton effective mass splitting has got a positive value when isoscalar effective mass is greater than the isovector effective mass and has a negative value for the opposite case. Furthermore, the neutron-proton effective mass splitting is found to have a linear dependence on asymmetry β. The second-order symmetry potential has a vital role in the determination of density slope of symmetry energy but it does not have any contribution on neutron-proton effective mass splitting. The finite-range effective interaction is compared with the SLy2, SKM, f{sub −}, f{sub 0}, and f{sub +} forms of interactions.

  14. Dosimetric response of radiochromic films to protons of low energies in the Bragg peak region

    NASA Astrophysics Data System (ADS)

    Battaglia, M. C.; Schardt, D.; Espino, J. M.; Gallardo, M. I.; Cortés-Giraldo, M. A.; Quesada, J. M.; Lallena, A. M.; Miras, H.; Guirado, D.

    2016-06-01

    One of the major advantages of proton or ion beams, applied in cancer treatment, is their excellent depth-dose profile exhibiting a low dose in the entrance channel and a distinct dose maximum (Bragg peak) near the end of range in tissue. In the region of the Bragg peak, where the protons or ions are almost stopped, experimental studies with low-energy particle beams and thin biological samples may contribute valuable information on the biological effectiveness in the stopping region. Such experiments, however, require beam optimization and special dosimetry techniques for determining the absolute dose and dose homogeneity for very thin biological samples. At the National Centre of Accelerators in Seville, one of the beam lines at the 3 MV Tandem Accelerator was equipped with a scattering device, a special parallel-plate ionization chamber with very thin electrode foils and target holders for cell cultures. In this work, we present the calibration in absolute dose of EBT3 films [Gafchromic radiotherapy films, http://www.ashland.com/products/gafchromic-radiotherapy-films] for proton energies in the region of the Bragg peak, where the linear energy transfer increases and becomes more significant for radiobiology studies, as well as the response of the EBT3 films for different proton energy values. To irradiate the films in the Bragg peak region, the energy of the beam was degraded passively, by interposing Mylar foils of variable thickness to place the Bragg peak inside the active layer of the film. The results obtained for the beam degraded in Mylar foils are compared with the dose calculated by means of the measurement of the beam fluence with an ionization chamber and the energy loss predicted by srim2008 code.

  15. Ion Desorption Stability in Superconducting High Energy Physics Proton Colliders

    SciTech Connect

    Turner, W.C.

    1995-05-29

    In this paper we extend our previous analysis of cold beam tube vacuum in a superconducting proton collider to include ion desorption in addition to thermal desorption and synchrotron radiation induced photodesorption. The new ion desorption terms introduce the possibility of vacuum instability. This is similar to the classical room temperature case but now modified by the inclusion of ion desorption coefficients for cryosorbed (physisorbed) molecules which can greatly exceed the coefficients for tightly bound molecules. The sojourn time concept for physisorbed H{sub 2} is generalized to include photodesorption and ion desorption as well as the usually considered thermal desorption. The ion desorption rate is density dependent and divergent so at the onset of instability the sojourn time goes to zero. Experimental data are used to evaluate the H{sub 2} sojourn time for the conditions of the Large Hadron Collider (LHC) and the situation is found to be stable. The sojourn time is dominated by photodesorption for surface density s(H{sub 2}) less than a monolayer and by thermal deposition for s(H{sub 2}) greater than a monolayer. For a few percent of a monolayer, characteristic of a beam screen, the photodesorption rate exceeds ion desorption rate by more than two orders of magnitude. The photodesorption rate corresponds to a sojourn time of approximately 100 sec. The paper next turns to the evaluation of stability margins and inclusion of gases heavier than H{sub 2} (CO, CO{sub 2} and CH{sub 4}), where ion desorption introduces coupling between molecular species. Stability conditions are worked out for a simple cold beam tube, a cold beam tube pumped from the ends and a cold beam tube with a co-axial perforated beam screen. In each case a simple inequality for stability of a single component is replaced by a determinant that must be greater than zero for a gas mixture. The connection with the general theory of feedback stability is made and it is shown that the gains

  16. Detection of Medium-Sized Polycyclic Aromatic Hydrocarbons via Fluorescence Energy Transfer

    PubMed Central

    Serio, Nicole; Prignano, Lindsey; Peters, Sean; Levine, Mindy

    2015-01-01

    Reported herein is the use of proximity-induced non-covalent energy transfer for the detection of medium-sized polycyclic aromatic hydrocarbons (PAHs). This energy transfer occurs within the cavity of γ-cyclodextrin in various aqueous environments, including human plasma and coconut water. Highly efficient energy transfer was observed, and the efficiency of the energy transfer is independent of the concentration of γ-cyclodextrin used, demonstrating the importance of hydrophobic binding in facilitating such energy transfer. Low limits of detection were also observed for many of the PAHs investigated, which is promising for the development of fluorescence-based detection schemes. PMID:25821390

  17. Proposed linear energy transfer areal detector for protons using radiochromic film

    SciTech Connect

    Mayer, Rulon; Lin, Liyong; Fager, Marcus; Douglas, Dan; McDonough, James; Carabe, Alejandro

    2015-04-15

    Radiation therapy depends on predictably and reliably delivering dose to tumors and sparing normal tissues. Protons with kinetic energy of a few hundred MeV can selectively deposit dose to deep seated tumors without an exit dose, unlike x-rays. The better dose distribution is attributed to a phenomenon known as the Bragg peak. The Bragg peak is due to relatively high energy deposition within a given distance or high Linear Energy Transfer (LET). In addition, biological response to radiation depends on the dose, dose rate, and localized energy deposition patterns or LET. At present, the LET can only be measured at a given fixed point and the LET spatial distribution can only be inferred from calculations. The goal of this study is to develop and test a method to measure LET over extended areas. Traditionally, radiochromic films are used to measure dose distribution but not for LET distribution. We report the first use of these films for measuring the spatial distribution of the LET deposited by protons. The radiochromic film sensitivity diminishes for large LET. A mathematical model correlating the film sensitivity and LET is presented to justify relating LET and radiochromic film relative sensitivity. Protons were directed parallel to radiochromic film sandwiched between solid water slabs. This study proposes the scaled-normalized difference (SND) between the Treatment Planning system (TPS) and measured dose as the metric describing the LET. The SND is correlated with a Monte Carlo (MC) calculation of the LET spatial distribution for a large range of SNDs. A polynomial fit between the SND and MC LET is generated for protons having a single range of 20 cm with narrow Bragg peak. Coefficients from these fitted polynomial fits were applied to measured proton dose distributions with a variety of ranges. An identical procedure was applied to the protons deposited from Spread Out Bragg Peak and modulated by 5 cm. Gamma analysis is a method for comparing the calculated

  18. Proposed linear energy transfer areal detector for protons using radiochromic film

    NASA Astrophysics Data System (ADS)

    Mayer, Rulon; Lin, Liyong; Fager, Marcus; Douglas, Dan; McDonough, James; Carabe, Alejandro

    2015-04-01

    Radiation therapy depends on predictably and reliably delivering dose to tumors and sparing normal tissues. Protons with kinetic energy of a few hundred MeV can selectively deposit dose to deep seated tumors without an exit dose, unlike x-rays. The better dose distribution is attributed to a phenomenon known as the Bragg peak. The Bragg peak is due to relatively high energy deposition within a given distance or high Linear Energy Transfer (LET). In addition, biological response to radiation depends on the dose, dose rate, and localized energy deposition patterns or LET. At present, the LET can only be measured at a given fixed point and the LET spatial distribution can only be inferred from calculations. The goal of this study is to develop and test a method to measure LET over extended areas. Traditionally, radiochromic films are used to measure dose distribution but not for LET distribution. We report the first use of these films for measuring the spatial distribution of the LET deposited by protons. The radiochromic film sensitivity diminishes for large LET. A mathematical model correlating the film sensitivity and LET is presented to justify relating LET and radiochromic film relative sensitivity. Protons were directed parallel to radiochromic film sandwiched between solid water slabs. This study proposes the scaled-normalized difference (SND) between the Treatment Planning system (TPS) and measured dose as the metric describing the LET. The SND is correlated with a Monte Carlo (MC) calculation of the LET spatial distribution for a large range of SNDs. A polynomial fit between the SND and MC LET is generated for protons having a single range of 20 cm with narrow Bragg peak. Coefficients from these fitted polynomial fits were applied to measured proton dose distributions with a variety of ranges. An identical procedure was applied to the protons deposited from Spread Out Bragg Peak and modulated by 5 cm. Gamma analysis is a method for comparing the calculated

  19. Study of the effects of high-energy proton beams on escherichia coli

    NASA Astrophysics Data System (ADS)

    Park, Jeong Chan; Jung, Myung-Hwan

    2015-10-01

    Antibiotic-resistant bacterial infection is one of the most serious risks to public health care today. However, discouragingly, the development of new antibiotics has progressed little over the last decade. There is an urgent need for alternative approaches to treat antibiotic-resistant bacteria. Novel methods, which include photothermal therapy based on gold nano-materials and ionizing radiation such as X-rays and gamma rays, have been reported. Studies of the effects of high-energy proton radiation on bacteria have mainly focused on Bacillus species and its spores. The effect of proton beams on Escherichia coli (E. coli) has been limitedly reported. Escherichia coli is an important biological tool to obtain metabolic and genetic information and is a common model microorganism for studying toxicity and antimicrobial activity. In addition, E. coli is a common bacterium in the intestinal tract of mammals. In this research, the morphological and the physiological changes of E. coli after proton irradiation were investigated. Diluted solutions of cells were used for proton beam radiation. LB agar plates were used to count the number of colonies formed. The growth profile of the cells was monitored by using the optical density at 600 nm. The morphology of the irradiated cells was observed with an optical microscope. A microarray analysis was performed to examine the gene expression changes between irradiated samples and control samples without irradiation. E coli cells have observed to be elongated after proton irradiation with doses ranging from 13 to 93 Gy. Twenty-two were up-regulated more than twofold in proton-irradiated samples (93 Gy) compared with unexposed one.

  20. First measurement of the spectral function at high energy and momentum in medium-heavy nuclei

    SciTech Connect

    Daniela Rohe; E97-006 collaboration

    2005-09-26

    The experiment E97-006 was performed at Jefferson Lab to measure the momentum and energy distribution of protons in the nucleus far from the region of the (approximate) validity of the mean field description, i.e. at high momentum and energies. The occurrence of this strength is long known from occupation numbers less than one. In the experiment reported here this strength was directly measured for the first time. The results are compared to modern many-body theories. Further the transparency factor of C12 was determined in the Q{sup 2}-region of 0.6 to 1.8 (GeV/c){sup 2}.

  1. Proton transfer pathways, energy landscape, and kinetics in creatine-water systems.

    PubMed

    Ivchenko, Olga; Whittleston, Chris S; Carr, Joanne M; Imhof, Petra; Goerke, Steffen; Bachert, Peter; Wales, David J

    2014-02-27

    We study the exchange processes of the metabolite creatine, which is present in both tumorous and normal tissues and has NH2 and NH groups that can transfer protons to water. Creatine produces chemical exchange saturation transfer (CEST) contrast in magnetic resonance imaging (MRI). The proton transfer pathway from zwitterionic creatine to water is examined using a kinetic transition network constructed from the discrete path sampling approach and an approximate quantum-chemical energy function, employing the self-consistent-charge density-functional tight-binding (SCC-DFTB) method. The resulting potential energy surface is visualized by constructing disconnectivity graphs. The energy landscape consists of two distinct regions corresponding to the zwitterionic creatine structures and deprotonated creatine. The activation energy that characterizes the proton transfer from the creatine NH2 group to water was determined from an Arrhenius fit of rate constants as a function of temperature, obtained from harmonic transition state theory. The result is in reasonable agreement with values obtained in water exchange spectroscopy (WEX) experiments.

  2. An Accumulator/Pre-Booster for the Medium-Energy Electron Ion Collider at Jlab

    SciTech Connect

    Erdelyi, B.; Manikonda, S. L.; Ostroumov, P. N.; Abeyratne, S.; Derbenev, Y. S.; Krafft, G. A.; Zhang, Y.

    2011-04-01

    Future nuclear physics facilities such as the proposed electron ion collider (MEIC) will need to achieve record high luminosities in order to maximize discovery potential. Among the necessary ingredients is the ability to generate, accumulate , accelerate, and store high current ion beams from protons to lead ions. One of the main components of this ion accelerator complex for MEIC chain is the accumulator that also doubles as a pre-booster, which takes 200 MeV protons from a superconducting linear accelerator, accumulates on the order of 1A beam, and boosts its energy to 3GeV, before extraction to the next accelerator in the chain, the large booster. This paper describes its design concepts, and summarizes some preliminary results, including linear optics, space charge dynamics, and spin polarization resonance analysis.

  3. Optimum angle-cut of collimator for dense objects in high-energy proton radiography

    NASA Astrophysics Data System (ADS)

    Xu, Hai-Bo; Zheng, Na

    2016-02-01

    The use of minus identity lenses with an angle-cut collimator can achieve high contrast images in high-energy proton radiography. This article presents the principles of choosing the angle-cut aperture of the collimator for different energies and objects. Numerical simulation using the Monte Carlo code Geant4 has been implemented to investigate the entire radiography for the French test object. The optimum angle-cut apertures of the collimators are also obtained for different energies. Supported by NSAF (11176001) and Science and Technology Developing Foundation of China Academy of Engineering Physics (2012A0202006)

  4. Understanding selenocysteine through conformational analysis, proton affinities, acidities and bond dissociation energies

    NASA Astrophysics Data System (ADS)

    Kaur, Damanjit; Sharma, Punita; Bharatam, Prasad V.; Kaur, Mondeep

    Density functional methods have been employed to characterize the gas phase conformations of selenocysteine. The 33 stable conformers of selenocysteine have been located on the potential energy surface using density functional B3LYP/6-31+G* method. The conformers are analyzed in terms of intramolecular hydrogen bonding interactions. The proton affinity, gas phase acidities, and bond dissociation energies have also been evaluated for different reactive sites of selenocysteine for the five lowest energy conformers at B3LYP/6-311++G*//B3LYP/6-31+G* level. Evaluation of these intrinsic properties reflects the antioxidant activity of selenium in selenocysteine.0

  5. Energy loss and longitudinal wakefield of relativistic short proton bunches in electron clouds

    NASA Astrophysics Data System (ADS)

    Boine-Frankenheim, O.; Gjonaj, E.; Petrov, F.; Yaman, F.; Weiland, T.; Rumolo, G.

    2012-05-01

    The aim of our study is the numerical computation of the wakefield and energy loss per unit length for relativistic, short (<10ns) proton bunches interacting with an electron cloud inside the beam pipe. We present analytical expressions for the energy loss in the impulse kick approximation. For the simulation of the wakefields a 2D self-consistent, electrostatic particle-in-cell (PIC) code is employed. Results for the energy loss and for the wakefields are presented for the parameter scope of the CERN LHC and SPS. For selected parameters the results are compared to a three-dimensional (3D) electromagnetic PIC code.

  6. Determination of the quenching correction factors for plastic scintillation detectors in therapeutic high-energy proton beams

    PubMed Central

    Wang, L L W; Perles, L A; Archambault, L; Sahoo, N; Mirkovic, D; Beddar, S

    2013-01-01

    The plastic scintillation detectors (PSD) have many advantages over other detectors in small field dosimetry due to its high spatial resolution, excellent water equivalence and instantaneous readout. However, in proton beams, the PSDs will undergo a quenching effect which makes the signal level reduced significantly when the detector is close to Bragg peak where the linear energy transfer (LET) for protons is very high. This study measures the quenching correction factor (QCF) for a PSD in clinical passive-scattering proton beams and investigates the feasibility of using PSDs in depth-dose measurements in proton beams. A polystyrene based PSD (BCF-12, ϕ0.5mm×4mm) was used to measure the depth-dose curves in a water phantom for monoenergetic unmodulated proton beams of nominal energies 100, 180 and 250 MeV. A Markus plane-parallel ion chamber was also used to get the dose distributions for the same proton beams. From these results, the QCF as a function of depth was derived for these proton beams. Next, the LET depth distributions for these proton beams were calculated by using the MCNPX Monte Carlo code, based on the experimentally validated nozzle models for these passive-scattering proton beams. Then the relationship between the QCF and the proton LET could be derived as an empirical formula. Finally, the obtained empirical formula was applied to the PSD measurements to get the corrected depth-dose curves and they were compared to the ion chamber measurements. A linear relationship between QCF and LET, i.e. Birks' formula, was obtained for the proton beams studied. The result is in agreement with the literature. The PSD measurements after the quenching corrections agree with ion chamber measurements within 5%. PSDs are good dosimeters for proton beam measurement if the quenching effect is corrected appropriately. PMID:23128412

  7. Bridging the momentum distribution and the potential energy surface of protons in hydrogen bonds

    NASA Astrophysics Data System (ADS)

    Morrone, Joseph; Lin, Lin; Car, Roberto; Parrinello, Michele

    2010-03-01

    Open path integral Car-Parrinello molecular dynamics studies have uncovered the proton momentum distribution in various phases of ice [1,2]. These systems exhibit a wide range of behavior, including symmetric hydrogen bonds and quantum tunneling. In this work, we provide an in-depth statistical analysis of the simulation results. This analysis reveals a direct relation between the open path formalism of quantum particles and their underlying potential energy surface. Application of this analysis to ice systems provides quantitative information about the principle axes of the potential energy surface that the proton experiences, and indicates that the oxygen-oxygen distance is a proper reaction coordinate for such systems. Our analysis also facilitates a direct observation of anharmonic effects along the principle axes. [1] J. A. Morrone and R. Car, Phys. Rev. Lett. 101, 17801, 2008. [2] J. A. Morrone, L. Lin and R. Car, J. Chem. Phys. 130, 204511, 2009.

  8. Using low-energy neutrinos from pion decay at rest to probe the proton strangeness.

    PubMed

    Pagliaroli, G; Lujan-Peschard, C; Mitra, M; Vissani, F

    2013-07-12

    The study of the neutral current elastic scattering of neutrinos on protons at lower energies can be used as a compelling probe to improve our knowledge of the strangeness of the proton. We consider a neutrino beam generated from pion decay at rest, as provided by a cyclotron or a spallation neutron source and a 1 kton scintillating detector with a potential similar to the Borexino detector. Despite several backgrounds from solar and radioactive sources, it is possible to estimate two optimal energy windows for the analysis, one between 0.65 and 1.1 MeV and another between 1.73 and 2.2 MeV. The expected number of neutral current events in these two regions, for an exposure of 1 yr, is enough to obtain an error on the strange axial charge 10 times smaller than available at present. PMID:23889387

  9. Characterization of warm dense matter produced by laser-accelerated high-energy protons

    NASA Astrophysics Data System (ADS)

    Nakatsutsumi, M.; Fuchs, J.; Mancic, A.; Robiche, J.; Renaudin, P.; Combis, P.; Dorchies, F.; Harmand, M.; Maynard, G.; Vassaux, J.; Mora, P.; Antici, P.; Fourmaux, S.; Audebert, P.

    2008-11-01

    Producing warm dense plasmas (WDM: solid density, few eV ˜ few 10s eV) is of interest for fundamental plasma physics or ICF. Laser-produced proton heating is of interest since they are short (<1ps) and deposit their energy volumetrically. Experiments were performed using the LULI 100 TW facility to create and characterize WDM. We used, (i) 2D time-resolved optical self-emission of the heated target, (ii) surface expansion velocity measurement through phase measurements of a reflecting probe beam, and (iii) x-ray absorption spectroscopy. We showed that we could produce quasi-uniform heating of solids, as suited for e.g. EoS measurements. Time-resolved solid-liquid-plasma transition has been measured, as well as energy-loss of MeV protons in warm dense plasmas.

  10. Development of a telescope for medium-energy gamma-ray astronomy

    NASA Astrophysics Data System (ADS)

    Hunter, Stanley D.; Bloser, Peter F.; Dion, Michael P.; DeNolfo, Georgia A.; Legere, Jason; McConnell, Mark L.; Nowicki, Suzanne F.; Ryan, James M.; Son, Seunghee; Stecker, Floyd W.

    2012-09-01

    The Advanced Energetic Pair Telescope (AdEPT) is being developed at GSFC as a future NASA MIDEX mission to explore the medium-energy (5-200 MeV) gamma-ray range. The enabling technology for AdEPT is the Three- Dimensional Track Imager (3-DTI), a gaseous time projection chamber. The high spatial resolution 3-D electron tracking of 3-DTI enables AdEPT to achieve high angular resolution gamma-ray imaging via pair production and triplet production (pair production on electrons) in the medium-energy range. The low density and high spatial resolution of 3-DTI allows the electron positron track directions to be measured before they are dominated by Coulomb scattering. Further, the significant reduction of Coulomb scattering allows AdEPT to be the first medium-energy gamma-ray telescope to have high gamma-ray polarization sensitivity. We review the science goals that can be addressed with a medium-energy pair telescope, how these goals drive the telescope design, and the realization of this design with AdEPT. The AdEPT telescope for a future MIDEX mission is envisioned as a 8 m3 active volume filled with argon at 2 atm. The design and performance of the 3-DTI detectors for the AdEPT telescope are described as well as the outstanding instrument challenges that need to be met for the AdEPT mission.

  11. Comprehensive description of J/ψ production in proton-proton collisions at collider energies

    SciTech Connect

    Ma, Yan -Qing; Venugopalan, Raju

    2014-11-04

    We employ a small x Color Glass Condensate + Non-Relativistic QCD (NRQCD) formalism to compute J/ψ production at low p⊥ in proton-proton collisions at collider energies. Very good agreement is obtained for total cross-sections, rapidity distributions and low momentum p⊥ distributions. Similar agreement is obtained for ψ' production. We observe an overlap region in p⊥ where our results match smoothly to those obtained in a next-to-leading order (NLO) collinearly factorized NRQCD formalism. The relative contribution of color singlet and color octet contributions can be quantified in the CGC+NRQCD framework, with the former contributing approximately 10% of the total cross-section.

  12. Production of [15O]water at low-energy proton cyclotrons.

    PubMed

    Powell, J; O'Neil, J P

    2006-07-01

    We report a simple system for producing [15O]H2O from 15N in a nitrogen/hydrogen gas target with recycling of the target nitrogen, allowing production on low-energy proton-only accelerators with minimal consumption of isotopically enriched 15N. The radiolabeled water is separated from the target gas and radiolytically produced ammonia by temporary freezing in a small trap at -40 degrees C.

  13. Production of [15O]Water at Low-Energy Proton Cyclotrons

    SciTech Connect

    Powell, James; O'Neil, James P.

    2005-12-12

    We report a simple system for producing [15O]H2O from nitrogen-15 in a nitrogen/hydrogen gas target with recycling of the target nitrogen, allowing production on low-energy proton-only accelerators with minimal consumption of isotopically enriched nitrogen-15. The radiolabeled water is separated from the target gas and radiolytically produced ammonia by temporary freezing in a small trap at -40 C.

  14. Recoil-proton polarization in high-energy deuteron photodisintegration with circularly plarized photons.

    SciTech Connect

    Jiang, X.; Arrington, J.; Benmokhtar, F.; Camsonne, A.; Chen, J. P.; Holt, R. J.; Qattan, I. A.; Reimer, P. E.; Schulte, E. C.; Wijesooriya, K.; Physics; Rutgers Univ.; Univ. Blaise Pascal; Thomas Jefferson National Accelerator Facility

    2007-05-01

    We measured the angular dependence of the three recoil-proton polarization components in two-body photodisintegration of the deuteron at a photon energy of 2 GeV. These new data provide a benchmark for calculations based on quantum chromodynamics. Two of the five existing models have made predictions of polarization observables. Both explain the longitudinal polarization transfer satisfactorily. Transverse polarizations are not well described, but suggest isovector dominance.

  15. Recoil-Proton Polarization in High-Energy Deuteron Photodisintegration with Circularly Polarized Photons

    SciTech Connect

    Jiang, X.; Benmokhtar, F.; Glashauser, C.; McCormick, K.; Ransome, R. D.; Arrington, J.; Holt, R. J.; Reimer, P. E.; Schulte, E. C.; Wijesooriya, K.; Camsonne, A.

    2007-05-04

    We measured the angular dependence of the three recoil-proton polarization components in two-body photodisintegration of the deuteron at a photon energy of 2 GeV. These new data provide a benchmark for calculations based on quantum chromodynamics. Two of the five existing models have made predictions of polarization observables. Both explain the longitudinal polarization transfer satisfactorily. Transverse polarizations are not well described, but suggest isovector dominance.

  16. Recoil-Proton Polarization in High-Energy Deuteron Photodisintegration with Circularly Polarized Photons

    SciTech Connect

    X. Jiang; J. Arrington; F. Benmokhtar; A. Camsonne; J. P. Chen; S. Choi; E. Chudakov; F. Cusanno; A. Deur; D. Dutta; F. Garibaldi; D. Gaskell; O. Gayou; R. Gilman; C. Glashauser; D. Hamilton; O. Hansen; D. W. Higinbotham; R. J. Holt; C. W. de Jager; M. K. Jones; L. J. Kaufman; E. R. Kinney; K. Kramer; L. Lagamba; R. de Leo; J. Lerose; D. Lhuillier; R. Lindgren; N. Liyanage; K. McCormick; Z.-E. Meziani; R. Michaels; B. Moffit; P. Monaghan; S. Nanda; K. D. Paschke; C. F. Perdrisat; V. Punjabi; I. A. Qattan; R. D. Ransome; P. E. Reimer; B. Reitz; A. Saha; E. C. Schulte; R. Sheyor; K. Slifer; P. Solvignon; V. Sulkosky; G. M. Urciuoli; E. Voutier; K. Wang; K. Wijesooriya; B. Wojtsekhowski; and L. Zhu

    2007-05-01

    We measured the angular dependence of the three recoil-proton polarization components in two-body photodisintegration of the deuteron at a photon energy of 2 GeV. These new data provide a benchmark for calculations based on quantum chromodynamics. Two of the five existing models have made predictions of polarization observables. Both explain the longitudinal polarization transfer satisfactorily. Transverse polarizations are not well described, but suggest isovector dominance.

  17. Angular dependence of recoil proton polarization in high-energy \\gamma d \\to p n

    SciTech Connect

    X. Jiang; J. Arrington; F. Benmokhtar; A. Camsonne; J.P. Chen; S. Choi; E. Chudakov; F. Cusanno; A. Deur; D. Dutta; F. Garibaldi; D. Gaskell; O. Gayou; R. Gilman; C. Glashauser; D. Hamilton; O. Hansen; D.W. Higinbotham; R.J. Holt; C.W. de Jager; M.K. Jones; L.J. Kaufman; E.R. Kinney; K. Kramer; L. Lagamba; R. de Leo; J. Lerose; D. Lhuillier; R. Lindgren; N. Liyanage; K. McCormick; Z.-E. Meziani; R. Michaels; B. Moffit; P. Monaghan; S. Nanda; K.D. Paschke; C.F. Perdrisat; V. Punjabi; I.A. Qattan; R.D. Ransome; P.E. Reimer; B. Reitz; A. Saha; E.C. Schulte; R. Sheyor; K. Slifer; P. Solvignon; V. Sulkosky; G.M. Urciuoli; E. Voutier; K. Wang; K. Wijesooriya; B. Wojtsekhowski; L. Zhu

    2007-02-26

    We measured the angular dependence of the three recoil proton polarization components in two-body photodisintegration of the deuteron at a photon energy of 2 GeV. These new data provide a benchmark for calculations based on quantum chromodynamics. Two of the five existing models have made predictions of polarization observables. Both explain the longitudinal polarization transfer satisfactorily.. Transverse polarizations are not well described, but suggest isovector dominance.

  18. Detecting cavitation in mercury exposed to a high-energy pulsed proton beam

    SciTech Connect

    Manzi, Nicholas J; Chitnis, Parag V; Holt, Ray G; Roy, Ronald A; Cleveland, Robin O; Riemer, Bernie; Wendel, Mark W

    2010-01-01

    The Oak Ridge National Laboratory Spallation Neutron Source employs a high-energy pulsed proton beam incident on a mercury target to generate short bursts of neutrons. Absorption of the proton beam produces rapid heating of the mercury, resulting in the formation of acoustic shock waves and the nucleation of cavitation bubbles. The subsequent collapse of these cavitation bubbles promote erosion of the steel target walls. Preliminary measurements using two passive cavitation detectors (megahertz-frequency focused and unfocused piezoelectric transducers) installed in a mercury test target to monitor cavitation generated by proton beams with charges ranging from 0.041 to 4.1 C will be reported on. Cavitation was initially detected for a beam charge of 0.082 C by the presence of an acoustic emission approximately 250 s after arrival of the incident proton beam. This emission was consistent with an inertial cavitation collapse of a bubble with an estimated maximum bubble radius of 0.19 mm, based on collapse time. The peak pressure in the mercury for the initiation of cavitation was predicted to be 0.6 MPa. For a beam charge of 0.41 C and higher, the lifetimes of the bubbles exceeded the reverberation time of the chamber (~300 s), and distinct windows of cavitation activity were detected, a phenomenon that likely resulted from the interaction of the reverberation in the chamber and the cavitation bubbles.

  19. Energies of backstreaming protons in the foreshock. [of cislunar solar wind region outside earth bow shock

    NASA Technical Reports Server (NTRS)

    Greenstadt, E. W.

    1976-01-01

    At least some part of the cislunar solar wind region outside the earth's bow shock is continuously populated by particles and waves of shock or magnetospheric origin. The varying precursor region, or foreshock, is divided into several subregions, not all geometrically distinct, which are defined by differing particle species and wavemodes. A first-order examination is presented of the way in which the geometry of the foreshock wave boundary of Diodato et al. (1976) can be translated into a geometry of return proton energies. A predicted pattern of energy versus detector location in the cislunar region is displayed for proton guiding-centers traveling upstream away from the quasi-parallel bow shock. Only the simplest case of gyrationless particles is considered. Important contributors to the spread in energies to be expected of ions coming from each segment are discussed. The actual pattern of return particles will be somewhat different from the idealized one discussed, because foreshock boundary-protons will be neither unidirectional nor monoenergetic.

  20. Proton and Electron Threshold Energy Measurements for Extravehicular Activity Space Suits. Chapter 2

    NASA Technical Reports Server (NTRS)

    Moyers, M. F.; Nelson, G. D.; Saganti, P. B.

    2003-01-01

    Construction of ISS will require more than 1000 hours of EVA. Outside of ISS during EVA, astronauts and cosmonauts are likely to be exposed to a large fluence of electrons and protons. Development of radiation protection guidelines requires the determination of the minimum energy of electrons and protons that penetrate the suits at various locations. Measurements of the water-equivalent thickness of both US. and Russian EVA suits were obtained by performing CT scans. Specific regions of interest of the suits were further evaluated using a differential range shift technique. This technique involved measuring thickness ionization curves for 6-MeV electron and 155-MeV proton beams with ionization chambers using a constant source-to-detector distance. The thicknesses were obtained by stacking polystyrene slabs immediately upstream of the detector. The thicknesses of the 50% ionizations relative to the maximum ionizations were determined. The detectors were then placed within the suit and the stack thickness adjusted until the 50% ionization was reestablished. The difference in thickness between the 50% thicknesses was then used with standard range-energy tables to determine the threshold energy for penetration. This report provides a detailed description of the experimental arrangement and results.

  1. Protonation state and free energy calculation of HIV-1 protease-inhibitor complex based on electrostatic polarisation effect

    NASA Astrophysics Data System (ADS)

    Yang, Maoyou; Jiang, Xiaonan; Jiang, Ning

    2014-06-01

    The protonation states of catalytic Asp25/25‧ residues remarkably affect the binding mechanism of the HIV-1 protease-inhibitor complex. Here we report a molecular dynamics simulation study, which includes electrostatic polarisation effect, to investigate the influence of Asp25/25‧ protonation states upon the binding free energy of the HIV-1 protease and a C2-symmetric inhibitor. Good agreements are obtained on inhibitor structure, hydrogen bond network, and binding free energy between our theoretical calculations and the experimental data. The calculations show that the Asp25 residue is deprotonated, and the Asp25‧ residue is protonated. Our results reveal that the Asp25/25‧ residues can have different protonation states when binding to different inhibitors although the protease and the inhibitors have the same symmetry. This study offers some insights into understanding the protonation state of HIV-1 protease-inhibitor complex, which could be helpful in designing new inhibitor molecules.

  2. Statistical Characterization of Medium-Duty Electric Vehicle Drive Cycles; NREL (National Renewable Energy Laboratory)

    SciTech Connect

    Prohaska, R.; Duran, A.; Ragatz, A.; Kelly, K.

    2015-05-03

    With funding from the U.S. Department of Energy’s Vehicle Technologies Office, the National Renewable Energy Laboratory (NREL) conducts real-world performance evaluations of advanced medium- and heavy-duty fleet vehicles. Evaluation results can help vehicle manufacturers fine-tune their designs and assist fleet managers in selecting fuel-efficient, low-emission vehicles that meet their economic and operational goals. In 2011, NREL launched a large-scale performance evaluation of medium-duty electric vehicles. With support from vehicle manufacturers Smith and Navistar, NREL research focused on characterizing vehicle operation and drive cycles for electric delivery vehicles operating in commercial service across the nation.

  3. Radiation mapping inside the bunkers of medium energy accelerators using a robotic carrier.

    PubMed

    Ravishankar, R; Bhaumik, T K; Bandyopadhyay, T; Purkait, M; Jena, S C; Mishra, S K; Sharma, S; Agashe, V; Datta, K; Sarkar, B; Datta, C; Sarkar, D; Pal, P K

    2013-10-01

    The knowledge of ambient and peak radiation levels prevailing inside the bunkers of the accelerator facilities is essential in assessing the accidental human exposure inside the bunkers and in protecting sensitive electronic equipments by minimizing the exposure to high intensity mixed radiation fields. Radiation field mapping dynamically, inside bunkers are rare, though generally dose-rate data are available in every particle accelerator facilities at specific locations. Taking into account of the fact that the existing neutron fields with a spread of energy from thermal up to the energy of the accelerated charged projectiles, prompt photons and other particles prevailing during cyclotron operation inside the bunkers, neutron and gamma survey meters with extended energy ranges attached to a robotic carrier have been used. The robotic carrier movement was controlled remotely from the control room with the help of multiple visible range optical cameras provided inside the bunkers and the wireless and wired protocols of communication helped its movement and data acquisition from the survey meters. Variable Energy Cyclotron Centre, Kolkata has positive ion accelerating facilities such as K-130 room Temperature Cyclotron, K-500 Super Conducting Cyclotron and a forthcoming 30 MeV Proton Medical Cyclotron with high beam current. The dose rates data for K-130 Room Temperature Cyclotron, VECC were collected for various energies of alpha and proton beams losing their total energy at different stages on different materials at various strategic locations of radiological importance inside the bunkers. The measurements established that radiation levels inside the machine bunker dynamically change depending upon the beam type, beam energy, machine operation parameters, deflector condition, slit placement and central region beam tuning. The obtained inference from the association of dose rates with the parameters like beam intensity, type and energy of projectiles, helped in

  4. On the idea of low-energy nuclear reactions in metallic lattices by producing neutrons from protons capturing "heavy" electrons

    NASA Astrophysics Data System (ADS)

    Tennfors, Einar

    2013-02-01

    The present article is a critical comment on Widom and Larsens speculations concerning low-energy nuclear reactions (LENR) based on spontaneous collective motion of protons in a room temperature metallic hydride lattice producing oscillating electric fields that renormalize the electron self-energy, adding significantly to the effective electron mass and enabling production of low-energy neutrons. The frequency and mean proton displacement estimated on the basis of neutron scattering from protons in palladium and applied to the Widom and Larsens model of the proton oscillations yield an electron mass enhancement less than one percent, far below the threshold for the proposed neutron production and even farther below the mass enhancement obtained by Widom and Larsen assuming a high charge density. Neutrons are not stopped by the Coulomb barrier, but the energy required for the neutron production is not low.

  5. WE-D-BRF-05: Quantitative Dual-Energy CT Imaging for Proton Stopping Power Computation

    SciTech Connect

    Han, D; Williamson, J; Siebers, J

    2014-06-15

    Purpose: To extend the two-parameter separable basis-vector model (BVM) to estimation of proton stopping power from dual-energy CT (DECT) imaging. Methods: BVM assumes that the photon cross sections of any unknown material can be represented as a linear combination of the corresponding quantities for two bracketing basis materials. We show that both the electron density (ρe) and mean excitation energy (Iex) can be modeled by BVM, enabling stopping power to be estimated from the Bethe-Bloch equation. We have implemented an idealized post-processing dual energy imaging (pDECT) simulation consisting of monogenetic 45 keV and 80 keV scanning beams with polystyrene-water and water-CaCl2 solution basis pairs for soft tissues and bony tissues, respectively. The coefficients of 24 standard ICRU tissue compositions were estimated by pDECT. The corresponding ρe, Iex, and stopping power tables were evaluated via BVM and compared to tabulated ICRU 44 reference values. Results: BVM-based pDECT was found to estimate ρe and Iex with average and maximum errors of 0.5% and 2%, respectively, for the 24 tissues. Proton stopping power values at 175 MeV, show average/maximum errors of 0.8%/1.4%. For adipose, muscle and bone, these errors result range prediction accuracies less than 1%. Conclusion: A new two-parameter separable DECT model (BVM) for estimating proton stopping power was developed. Compared to competing parametric fit DECT models, BVM has the comparable prediction accuracy without necessitating iterative solution of nonlinear equations or a sample-dependent empirical relationship between effective atomic number and Iex. Based on the proton BVM, an efficient iterative statistical DECT reconstruction model is under development.

  6. On the feasibility of increasing the energy of laser-accelerated protons by using low-density targets

    SciTech Connect

    Brantov, A. V. Bychenkov, V. Yu.

    2015-06-15

    Optimal regimes of proton acceleration in the interaction of short high-power laser pulses with thin foils and low-density targets are determined by means of 3D numerical simulation. It is demonstrated that the maximum proton energy can be increased by using low-density targets in which ions from the front surface of the target are accelerated most efficiently. It is shown using a particular example that, for the same laser pulse, the energy of protons accelerated from a low-density target can be increased by one-third as compared to a solid-state target.

  7. The clinical impact of uncertainties in the mean excitation energy of human tissues during proton therapy

    NASA Astrophysics Data System (ADS)

    Besemer, Abigail; Paganetti, Harald; Bednarz, Bryan

    2013-02-01

    Uncertainties in the estimated mean excitation energies (I-values) needed for calculating proton stopping powers can be in the order of 10-15%, which introduces a fundamental limitation in the accuracy of proton range determination. Previous efforts have quantified shifts in proton depth dose distributions due to I-value uncertainties in water and homogenous tissue phantoms. This study is the first to quantify the clinical impact of I-value uncertainties on proton dose distributions within patient geometries. A previously developed Geant4 based Monte Carlo code was used to simulate a proton treatment plan for three patients (prostate, pancreases, and liver) with varying tissue I-values. A uniform variation study was conducted in which the tissue I-values were varied by ±5% and ±10% of the nominal values as well as a probabilistic variation study in which the I-values were randomly sampled according to a normal distribution with the mean equal to the nominal I-value and a standard deviation of 5 and 10% of the nominal values. Modification of tissue I-values impacted both the proton range and SOBP width. R90 range shifts up to 7.7 mm (4.4.%) and R80 range shifts up to 4.8 mm (1.9%) from the nominal range were recorded. Modulating the tissue I-values by 10% the nominal value resulted in up to a 3.5% difference mean dose in the target volumes and organs at risk compared to the nominal case. The range and dose differences were the largest for the deeper-seated prostate and pancreas cases. The treatments that were simulated with randomly sampled I-values resulted in range and dose differences that were generally within the upper and lower bounds set by the 10% uniform variations. This study demonstrated the impact of I-value uncertainties on patient dose distributions. Clearly, sub-millimeter precision in proton therapy would necessitate a reduction in I-value uncertainties to ensure an efficacious clinical outcome.

  8. Dual Energy CT Angiography of Peripheral Arterial Disease: Feasibility of Using Lower Contrast Medium Volume

    PubMed Central

    Almutairi, Abdulrahman; Sun, Zhonghua; Poovathumkadavi, Abduljaleel; Assar, Tarek

    2015-01-01

    Objective One of the main drawbacks associated with Dual Energy Computed Tomography Angiography (DECTA) is the risk of developing contrast medium-induced nephropathy (CIN). The aim of the present study was firstly, to design an optimal CT imaging protocol by determining the feasibility of using a reduced contrast medium volume in peripheral arterial DECTA, and secondly, to compare the results with those obtained from using routine contrast medium volume. Methods Thirty four patients underwent DECTA for the diagnosis of peripheral arterial disease. They were randomly divided into two groups: Group 1 (routine contrast volume group) with n = 17, injection rate 4–5 ml/s, and 1.5 ml/kg of contrast medium, and Group 2 ((low contrast volume group), with n = 17, injection rate 4–5ml/s, and contrast medium volume 0.75 ml/kg. A fast kilovoltage—switching 64-slice CT scanner in the dual-energy mode was employed for the study. A total of 6 datasets of monochromatic images at 50, 55, 60, 65, 70 and 75 keV levels were reconstructed with adaptive statistical iterative reconstruction (ASIR) at 50%. A 4-point scale was the tool for qualitative analysis of results. The two groups were compared and assessed quantitatively for image quality on the basis of signal-to-noise ratio (SNR) and contrast-to-noise-ratio (CNR). Radiation and contrast medium doses were also compared. Results The overall mean CT attenuation and mean noise for all lower extremity body parts was significantly lower for the low volume contrast group (p<0.001), and varied significantly between groups (p = 0.001), body parts (p<0.001) and keVs (p<0.001). The interaction between group body parts was significant with CT attenuation and CNR (p = 0.002 and 0.003 respectively), and marginally significant with SNR (p = 0.047), with minimal changes noticed between the two groups. Group 2 (low contrast volume group) displayed the lowest image noise between 65 and 70 keV, recorded the highest SNR and CNR at 65 keV, and

  9. Second dip as a signature of ultrahigh energy proton interactions with cosmic microwave background radiation.

    PubMed

    Berezinsky, V; Gazizov, A; Kachelrieb, M

    2006-12-01

    We discuss as a new signature for the interaction of extragalactic ultrahigh energy protons with cosmic microwave background radiation a spectral feature located at E= 6.3 x 10(19) eV in the form of a narrow and shallow dip. It is produced by the interference of e+e(-)-pair and pion production. We show that this dip and, in particular, its position are almost model-independent. Its observation by future ultrahigh energy cosmic ray detectors may give the conclusive confirmation that an observed steepening of the spectrum is caused by the Greisen-Zatsepin-Kuzmin effect.

  10. Angular and energy distributions of electrons produced in arbitrary biomaterials by proton impact.

    PubMed

    de Vera, Pablo; Garcia-Molina, Rafael; Abril, Isabel

    2015-01-01

    We present a simple method for obtaining reliable angular and energy distributions of electrons ejected from arbitrary condensed biomaterials by proton impact. Relying on a suitable description of the electronic excitation spectrum and a physically motivated relation between the ion and electron scattering angles, it yields cross sections in rather good agreement with experimental data in a broad range of ejection angles and energies, by only using as input the target composition and density. The versatility and simplicity of the method, which can be also extended to other charged particles, make it especially suited for obtaining ionization data for any complex biomaterial present in realistic cellular environments.

  11. Intermediate energy proton stopping power for hydrogen molecules and monoatomic helium gas

    NASA Technical Reports Server (NTRS)

    Xu, Y. J.; Khandelwal, G. S.; Wilson, J. W.

    1984-01-01

    Stopping power in the intermediate energy region (100 keV to 1 MeV) was investigated, based on the work of Lindhard and Winther, and on the local plasma model. The theory is applied to calculate stopping power of hydrogen molecules and helium gas for protons of energy ranging from 100 keV to 2.5 MeV. Agreement with the experimental data is found to be within 10 percent. Previously announced in STAR as N84-16955

  12. Angular and Energy Distributions of Electrons Produced in Arbitrary Biomaterials by Proton Impact

    NASA Astrophysics Data System (ADS)

    de Vera, Pablo; Garcia-Molina, Rafael; Abril, Isabel

    2015-01-01

    We present a simple method for obtaining reliable angular and energy distributions of electrons ejected from arbitrary condensed biomaterials by proton impact. Relying on a suitable description of the electronic excitation spectrum and a physically motivated relation between the ion and electron scattering angles, it yields cross sections in rather good agreement with experimental data in a broad range of ejection angles and energies, by only using as input the target composition and density. The versatility and simplicity of the method, which can be also extended to other charged particles, make it especially suited for obtaining ionization data for any complex biomaterial present in realistic cellular environments.

  13. Regolith Biological Shield for a Lunar Outpost from High Energy Solar Protons

    NASA Astrophysics Data System (ADS)

    Pham, Tai T.; El-Genk, Mohamed S.

    2008-01-01

    Beyond Earth atmosphere, natural space radiation from Galactic Cosmic Rays and Solar Energetic Protons (SEPs) represents a significant hazard to both manned and robotic missions. For lunar settlements, protecting astronauts from SEPs is a key safety issue that needs to be addressed by identifying appropriate shielding materials. This paper investigates the interaction of SEPs with the lunar regolith, and quantifies the effectiveness of the regolith as a biological shield for a human habitat, compared to aluminum, presently the standard shielding material. Also calculated is the shielding thickness to reduce the dose in the habitat to those recommended by International Radiation Protection Committee and by NASA for operation on the international space station. The present calculations are for the most energetic solar event of February 1956, which included high energy protons up to 1000 MeV. Results show that the lunar regolith is as effective as aluminum for shielding lunar outposts. A large thickness of the regolith (~30 g/cm2) would be needed to reduce the dose in the habitat from high energy protons below the 30 days flight crew limit of 25 Rem (or 250 mSv) and significantly more shielding would be needed (~150 g/cm2) to reduce the dose down to the limit for radiation workers of 5 Rem (or 50 mSv).

  14. Regolith Biological Shield for a Lunar Outpost from High Energy Solar Protons

    SciTech Connect

    Pham, Tai T.; El-Genk, Mohamed S.

    2008-01-21

    Beyond Earth atmosphere, natural space radiation from Galactic Cosmic Rays and Solar Energetic Protons (SEPs) represents a significant hazard to both manned and robotic missions. For lunar settlements, protecting astronauts from SEPs is a key safety issue that needs to be addressed by identifying appropriate shielding materials. This paper investigates the interaction of SEPs with the lunar regolith, and quantifies the effectiveness of the regolith as a biological shield for a human habitat, compared to aluminum, presently the standard shielding material. Also calculated is the shielding thickness to reduce the dose in the habitat to those recommended by International Radiation Protection Committee and by NASA for operation on the international space station. The present calculations are for the most energetic solar event of February 1956, which included high energy protons up to 1000 MeV. Results show that the lunar regolith is as effective as aluminum for shielding lunar outposts. A large thickness of the regolith ({approx}30 g/cm{sup 2}) would be needed to reduce the dose in the habitat from high energy protons below the 30 days flight crew limit of 25 Rem (or 250 mSv) and significantly more shielding would be needed ({approx}150 g/cm{sup 2}) to reduce the dose down to the limit for radiation workers of 5 Rem (or 50 mSv)

  15. Development of an Abort Gap Monitor for High-Energy Proton Rings

    NASA Astrophysics Data System (ADS)

    Beche, J.-F.; Byrd, J.; De Santis, S.; Denes, P.; Placidi, M.; Turner, W.; Zolotorev, M.

    2004-11-01

    The fill pattern in proton synchrotrons usually features an empty gap, longer than the abort kicker raise time, for machine protection. This gap is referred to as the "abort gap," and any particles, which may accumulate in it due to injection errors and diffusion between RF buckets, would be lost inside the ring, rather than in the beam dump, during the kicker firing. In large proton rings, due to the high energies involved, it is vital to monitor the build up of charges in the abort gap with a high sensitivity. We present a study of an abort gap monitor based on a photomultiplier with a gated microchannel plate, which would allow for detecting low charge densities by monitoring the synchrotron radiation emitted. We show results of beam test experiments at the Advanced Light Source using a Hamamatsu 5916U MCP-PMT and compare them to the specifications for the Large Hadron Collider.

  16. Development of an abort gap monitor for high-energy proton rings

    SciTech Connect

    Beche, Jean-Francois; Byrd, John; De Santis, Stefano; Denes, Peter; Placidi, Massimo; Turner, William; Zolotorev, Max

    2004-05-03

    The fill pattern in proton synchrotrons usually features an empty gap, longer than the abort kicker raise time, for machine protection. This gap is referred to as the ''abort gap'' and any particles, which may accumulate in it due to injection errors and diffusion between RF buckets, would be lost inside the ring, rather than in the beam dump, during the kicker firing. In large proton rings, due to the high energies involved, it is vital to monitor the build up of charges in the abort gap with a high sensitivity. We present a study of an abort gap monitor based on a photomultiplier with a gated microchannel plate, which would allow for detecting low charge densities by monitoring the synchrotron radiation emitted. We show results of beam test experiments at the Advanced Light Source using a Hamamatsu 5916U MCP-PMT and compare them to the specifications for the Large Hadron Collider

  17. Characteristics of Protons Exiting from a Polyethylene Converter Irradiated by Neutrons with Energies between 1 keV and 10 MeV.

    PubMed

    Nikezic, D; Shahmohammadi Beni, Mehrdad; Krstic, D; Yu, K N

    2016-01-01

    Monte Carlo method has been used to determine the efficiency for proton production and to study the energy and angular distributions of the generated protons. The ENDF library of cross sections is used to simulate the interactions between the neutrons and the atoms in a polyethylene (PE) layer, while the ranges of protons with different energies in PE are determined using the Stopping and Range of Ions in Matter (SRIM) computer code. The efficiency of proton production increases with the PE layer thickness. However the proton escaping from a certain polyethylene volume is highly dependent on the neutron energy and target thickness, except for a very thin PE layer. The energy and angular distributions of protons are also estimated in the present paper, showing that, for the range of energy and thickness considered, the proton flux escaping is dependent on the PE layer thickness, with the presence of an optimal thickness for a fixed primary neutron energy. PMID:27362656

  18. Characteristics of Protons Exiting from a Polyethylene Converter Irradiated by Neutrons with Energies between 1 keV and 10 MeV

    PubMed Central

    Nikezic, D.; Shahmohammadi Beni, Mehrdad; Krstic, D.; Yu, K. N.

    2016-01-01

    Monte Carlo method has been used to determine the efficiency for proton production and to study the energy and angular distributions of the generated protons. The ENDF library of cross sections is used to simulate the interactions between the neutrons and the atoms in a polyethylene (PE) layer, while the ranges of protons with different energies in PE are determined using the Stopping and Range of Ions in Matter (SRIM) computer code. The efficiency of proton production increases with the PE layer thickness. However the proton escaping from a certain polyethylene volume is highly dependent on the neutron energy and target thickness, except for a very thin PE layer. The energy and angular distributions of protons are also estimated in the present paper, showing that, for the range of energy and thickness considered, the proton flux escaping is dependent on the PE layer thickness, with the presence of an optimal thickness for a fixed primary neutron energy. PMID:27362656

  19. Characteristics of Protons Exiting from a Polyethylene Converter Irradiated by Neutrons with Energies between 1 keV and 10 MeV.

    PubMed

    Nikezic, D; Shahmohammadi Beni, Mehrdad; Krstic, D; Yu, K N

    2016-01-01

    Monte Carlo method has been used to determine the efficiency for proton production and to study the energy and angular distributions of the generated protons. The ENDF library of cross sections is used to simulate the interactions between the neutrons and the atoms in a polyethylene (PE) layer, while the ranges of protons with different energies in PE are determined using the Stopping and Range of Ions in Matter (SRIM) computer code. The efficiency of proton production increases with the PE layer thickness. However the proton escaping from a certain polyethylene volume is highly dependent on the neutron energy and target thickness, except for a very thin PE layer. The energy and angular distributions of protons are also estimated in the present paper, showing that, for the range of energy and thickness considered, the proton flux escaping is dependent on the PE layer thickness, with the presence of an optimal thickness for a fixed primary neutron energy.

  20. Theory of proton-coupled electron transfer in energy conversion processes.

    PubMed

    Hammes-Schiffer, Sharon

    2009-12-21

    Proton-coupled electron transfer (PCET) reactions play an essential role in a broad range of energy conversion processes, including photosynthesis and respiration. These reactions also form the basis of many types of solar fuel cells and electrochemical devices. Recent advances in the theory of PCET enable the prediction of the impact of system properties on the reaction rates. These predictions may guide the design of more efficient catalysts for energy production, including those based on artificial photosynthesis and solar energy conversion. This Account summarizes the theoretically predicted dependence of PCET rates on system properties and illustrates potential approaches for tuning the reaction rates in chemical systems. A general theoretical formulation for PCET reactions has been developed over the past decade. In this theory, PCET reactions are described in terms of nonadiabatic transitions between the reactant and product electron-proton vibronic states. A series of nonadiabatic rate constant expressions for both homogeneous and electrochemical PCET reactions have been derived in various well-defined limits. Recently this theory has been extended to include the effects of solvent dynamics and to describe ultrafast interfacial PCET. Analysis of the rate constant expressions provides insight into the underlying physical principles of PCET and enables the prediction of the dependence of the rates on the physical properties of the system. Moreover, the kinetic isotope effect, which is the ratio of the rates for hydrogen and deuterium, provides a useful mechanistic probe. Typically the PCET rate will increase as the electronic coupling and temperature increase and as the total reorganization energy and equilibrium proton donor-acceptor distance decrease. The rate constant is predicted to increase as the driving force becomes more negative, rather than exhibit turnover behavior in the inverted region, because excited vibronic product states associated with low

  1. Energy Dissipation of Energetic Electrons in the Inhomogeneous Intergalactic Medium during the Epoch of Reionization

    NASA Astrophysics Data System (ADS)

    Kaurov, Alexander A.

    2016-06-01

    We explore a time-dependent energy dissipation of the energetic electrons in the inhomogeneous intergalactic medium (IGM) during the epoch of cosmic reionization. In addition to the atomic processes, we take into account the inverse Compton (IC) scattering of the electrons on the cosmic microwave background photons, which is the dominant channel of energy loss for electrons with energies above a few MeV. We show that: (1) the effect on the IGM has both local (atomic processes) and non-local (IC radiation) components; (2) the energy distribution between hydrogen and helium ionizations depends on the initial energy of an electron; (3) the local baryon overdensity significantly affects the fractions of energy distributed in each channel; and (4) the relativistic effect of the atomic cross-section becomes important during the epoch of cosmic reionization. We release our code as open source for further modification by the community.

  2. System engineering and energy costs of small and medium wind turbines

    SciTech Connect

    Tu, P K.C.

    1985-07-01

    A preliminary system-level, computational model was developed to allow broad assessment and optimization of wind turbine design and costs analysis at The Wind Energy Research Center, Solar Energy Research Institute under contract to the US Department of Energy (DOE). This paper briefly describes the basic principles used in the model for energy capture and cost-of-energy (COE), and demonstrates the model's usefulness in determining the effects of rotor and system design modifications. The model's utilization for conducting parametric studies and defining the energy cost of small and medium-sized wind turbines is also shown. Topics of interest to wind turbine engineers and designers include the effects on rotor performance of airfoil geometry, blade pitch angle setting, and the system RPM schedule, etc.

  3. System engineering and energy cost analysis of small and medium wind turbines

    NASA Astrophysics Data System (ADS)

    Tu, P. K. C.

    1985-07-01

    A preliminary system-level, computational model was developed to allow broad assessment and optimization of wind turbine design and costs analysis at The Wind Energy Research Center, Solar Energy Research Institute under contract to the US Department of Energy (DOE). This paper briefly describes the basic principles used in the model for energy capture and cost-of-energy (COE), and demonstrates the model's usefulness in determining the effects of rotor and system design modifications. The model's utilization for conducting parametric studies and defining the energy cost of small and medium-sized wind turbines is also shown. Topics of interest to wind turbine engineers and designers include the effects on rotor performance of airfoil geometry, blade pitch angle setting, and the system RPM schedule, etc.

  4. Proton capture cross sections on neutron-magic 144Sm at astrophysically relevant energies

    NASA Astrophysics Data System (ADS)

    Kinoshita, N.; Hayashi, K.; Ueno, S.; Yatsu, Y.; Yokoyama, A.; Takahashi, N.

    2016-02-01

    Background: The p nuclei, which are not produced by neutron capture processes, are present with a typical isotopic abundance of 0.01%-0.3%. Abundance decreases with an increase in atomic number. However, the neutron-magic isotopes of 92Mo and 144Sm exhibit unusually large abundances in comparison. A combination of proton and α -particle capture reactions and neutron emission reactions are key to understanding this issue. Currently, complex network calculations do not have access to much experimental data, and hence require theoretically predicted reaction rates in order to estimate final abundances produced in nucleosynthesis. Purpose: Few experimental cross sections of (p ,γ) reactions on heavy nuclides with mass numbers of 130-150 have been reported. The 144Sm(p ,γ )145Eu reaction is the main destruction pathway for the nucleosynthesis of the 144Sm nuclide. In the present paper, experimental cross sections of the 144Sm(p ,γ )145Eu reaction at a range including astrophysically relevant energies for the p process were determined to compare with theoretical predictions using the Hauser-Feshback statistical model. Methods: The 144Sm was deposited on a high-purity Al foil with the molecular plating method. Stacks consisting of Ta degrader foils, 144Sm targets, and Cu foils used as flux monitors were irradiated with 14.0-MeV proton beams. The 144Sm(p ,γ )145Eu cross sections were determined from the 145Eu activities and the proton fluence estimated from the 65Zn activity in the Cu monitor foil. The proton energies bombarded on each 144Sm target were estimated using srim2013. Results: We determined the 144Sm(p ,γ )145Eu cross sections at proton energies between 2.8 and 7.6 MeV. These energies encompass nucleosynthesis temperatures between 3 and 5 GK. The cross sections at energies higher than 3.8 MeV agreed well with theoretically predicted cross sections using talys using the generalized superfluid (GS) model for level densities. However, calculations using non

  5. High order magnetic optics for high dynamic range proton radiography at a kinetic energy of 800 MeV.

    PubMed

    Sjue, S K L; Mariam, F G; Merrill, F E; Morris, C L; Saunders, A

    2016-01-01

    Flash radiography with 800 MeV kinetic energy protons at Los Alamos National Laboratory is an important experimental tool for investigations of dynamic material behavior driven by high explosives or pulsed power. The extraction of quantitative information about density fields in a dynamic experiment from proton generated images requires a high fidelity model of the proton imaging process. It is shown that accurate calculations of the transmission through the magnetic lens system require terms beyond second order for protons far from the tune energy. The approach used integrates the correlated multiple Coulomb scattering distribution simultaneously over the collimator and the image plane. Comparison with a series of static calibration images demonstrates the model's accurate reproduction of both the transmission and blur over a wide range of tune energies in an inverse identity lens that consists of four quadrupole electromagnets. PMID:26827356

  6. High order magnetic optics for high dynamic range proton radiography at a kinetic energy of 800 MeV

    NASA Astrophysics Data System (ADS)

    Sjue, S. K. L.; Mariam, F. G.; Merrill, F. E.; Morris, C. L.; Saunders, A.

    2016-01-01

    Flash radiography with 800 MeV kinetic energy protons at Los Alamos National Laboratory is an important experimental tool for investigations of dynamic material behavior driven by high explosives or pulsed power. The extraction of quantitative information about density fields in a dynamic experiment from proton generated images requires a high fidelity model of the proton imaging process. It is shown that accurate calculations of the transmission through the magnetic lens system require terms beyond second order for protons far from the tune energy. The approach used integrates the correlated multiple Coulomb scattering distribution simultaneously over the collimator and the image plane. Comparison with a series of static calibration images demonstrates the model's accurate reproduction of both the transmission and blur over a wide range of tune energies in an inverse identity lens that consists of four quadrupole electromagnets.

  7. Energy transport mechanism in the form of proton soliton in a one-dimensional hydrogen-bonded polypeptide chain.

    PubMed

    Kavitha, L; Priya, R; Ayyappan, N; Gopi, D; Jayanthi, S

    2016-01-01

    The dynamics of protons in a one-dimensional hydrogen-bonded (HB) polypeptide chain (PC) is investigated theoretically. A new Hamiltonian is formulated with the inclusion of higher-order molecular interactions between peptide groups (PGs). The wave function of the excitation state of a single particle is replaced by a new wave function of a two-quanta quasi-coherent state. The dynamics is governed by a higher-order nonlinear Schrödinger equation and the energy transport is performed by the proton soliton. A nonlinear multiple-scale perturbation analysis has been performed and the evolution of soliton parameters such as velocity and amplitude is explored numerically. The proton soliton is thermally stable and very robust against these perturbations. The energy transport by the proton soliton is more appropriate to understand the mechanism of energy transfer in biological processes such as muscle contraction, DNA replication, and neuro-electric pulse transfer on biomembranes.

  8. Effects of nanosecond-scale prepulse on generation of high-energy protons in target normal sheath acceleration

    SciTech Connect

    Wang, W. P.; Shen, B. F.; Zhang, H.; Xu, Y.; Li, Y. Y.; Lu, X. M.; Wang, C.; Liu, Y. Q.; Shi, Y.; Leng, Y. X.; Liang, X. Y.; Li, R. X.; Xu, Z. Z.; Lu, J. X.; Wang, N. Y.

    2013-06-03

    A pulse cleaner based on noncollinear optical-parametric amplification and second-harmonic generation processes is used to improve the contrast of a laser of peak intensity {approx}2 Multiplication-Sign 10{sup 19} W/cm{sup 2} to {approx}10{sup 11} at 100 ps before the peak of the main pulse. A 7 MeV proton beam is observed when a 2.5 {mu}m-thick Al foil is irradiated by this high-contrast laser. The maximum proton energy decreases to 2.9 MeV when a low-contrast ({approx}10{sup 8}) laser is used. Two-dimensional particle-in-cell simulations combined with MULTI simulations show that the maximum proton energy sensitively relies on the detecting direction. The ns-time-scale prepulse can bend a thin target before the main pulse arrives, which reduces maximum proton energy in the target normal sheath acceleration.

  9. Calculating alpha Eigenvalues in a Continuous-Energy Infinite Medium with Monte Carlo

    SciTech Connect

    Betzler, Benjamin R.; Kiedrowski, Brian C.; Brown, Forrest B.; Martin, William R.

    2012-09-04

    The {alpha} eigenvalue has implications for time-dependent problems where the system is sub- or supercritical. We present methods and results from calculating the {alpha}-eigenvalue spectrum for a continuous-energy infinite medium with a simplified Monte Carlo transport code. We formulate the {alpha}-eigenvalue problem, detail the Monte Carlo code physics, and provide verification and results. We have a method for calculating the {alpha}-eigenvalue spectrum in a continuous-energy infinite-medium. The continuous-time Markov process described by the transition rate matrix provides a way of obtaining the {alpha}-eigenvalue spectrum and kinetic modes. These are useful for the approximation of the time dependence of the system.

  10. Low-Energy Nuclear Reactions of Protons in Host Metals at Picometre Distance

    SciTech Connect

    Heinrich Hora; George H. Miley; Jak C. Kelly

    2000-11-12

    A review is given for the explanation of the measurements of Miley et al. of a fully reproducible generation of nuclei of the whole periodic table by protons in host metals during a several-weeks reaction. Similar low-energy nuclear reactions (LENR) were observed by other groups. The fact that the heavy nuclides are not due to pollution can be seen from the fact that such very rare elements as thulium and terbium were detected by unique K-shell X-ray spectra. The nuclear reaction energy goes into the heavy nuclei as measured from much bigger traces in CR39 than from alphas. The fact that any reaction of the protons results in stable daughter nuclei is confirmed by the fact that the highest energy gain is resulting with stable reaction products. This has been explained in Ref. 2, and the energy gain for the heavy element generation by a compound reaction was discussed. The explanation is based on the model of the authors from 1989 to assume free motion of the protons contrary to localized crystalline states. A relation of the reaction time U on distance d of the reacting nuclei by a power law with an exponent 34.8 was derived. Based on few reproducible D-D reactions, a reaction time near the range of megaseconds and a reaction distance of nanometers was concluded. A splendid confirmation of the picometre-megasecond reactions was achieved by Li et al. from his direct quantum mechanical calculations of the hot fusion D-T reactions based on a one-step selective resonance tunneling model. Li et al. were able for the first time to derive the cross sections of the hot fusion. Li's application to picometre distance showed megasecond reaction times with no neutron or gamma emission. Because of the imaginary part in the Schroedinger potential, the problem of the level width is reduced by damping.

  11. High and low energy proton radiation damage in p/n InP MOCVD solar cells

    NASA Technical Reports Server (NTRS)

    Rybicki, George; Weinberg, Irving; Scheiman, Dave; Vargas-Aburto, Carlos

    1995-01-01

    InP p(+)nn(+) MOCVD solar cells were irradiated with 0.2 MeV and 10 MeV protons to a fluence of 10(exp 13)/sq cm. The degradation of power output, IV behavior, carrier concentration and defect concentration were observed at intermediate points throughout the irradiations. The 0.2 MeV proton irradiated solar cells suffered much greater and more rapid degradation in power output than those irradiated with 10 meV protons. The efficiency losses were accompanied by larger increases in the recombination currents in the 0.2 MeV proton irradiated solar cells. The low energy proton irradiations also had a larger impact on the series resistance of the solar cells. Despite the radiation induced damage, the carrier concentration in the base of the solar cells showed no reduction after 10 MeV or 0.2 MeV proton irradiations and even increased during irradiation with 0.2 MeV protons. In a DLTS study of the irradiated samples, the minority carrier defects H4 and H5 at E(v) + 0.33 and E(v) + 0.52 eV and the majority carrier defects E7 and E10 at E(c)- 0.39 and E(c)-0.74 eV, were observed. The defect introduction rates for the 0.2 MeV proton irradiations were about 20 times higher than for the 10 MeV proton irradiations. The defect E10, observed here after irradiation, has been shown to act as a donor in irradiated n-type InP and may be responsible for obscuring carrier removal. The results of this study are consistent with the much greater damage produced by low energy protons whose limited range causes them to stop in the active region of the solar cell.

  12. Ab initio calculations of free energy barriers for chemical reactions in solution: proton transfer in [FHF]-.

    PubMed

    Muller, R P; Warshel, A

    1996-01-01

    This paper describes a hybrid ab initio quantum mechanical/molecular mechanics (QM/MM) method for calculating activation free energies of chemical reactions in solution, using molecular mechanics force fields for the solvent and an ab initio technique that incorporates the potential from the solvent in its Hamiltonian for the solute. The empirical valence bond (EVB) method is used as a reference potential for the ab initio free energy calculation, and drives the reaction along the proper coordinate, thus overcoming problems encountered by direct attempts to use molecular orbital methods in calculations of activation free energies. The utility of our method is illustrated by calculating the activation free energy for proton transfer between fluoride ions in the [FHF]-system, in both polar and nonpolar solution.

  13. Measuring Neutron-Proton Radiative Capture Cross-section at Low Energy

    NASA Astrophysics Data System (ADS)

    Yu, To Chin; Kovash, Michael; Matthews, June; Yang, Hongwei; Yang, Yunjie

    2015-10-01

    The experiment aims to fill in a gap in our data for the cross-section of neutron-proton radiative capture (p(n,d γ)) at energies below 500 keV. Current measurements in this energy range are scarce and inconsistent with theoretical predictions and with each other. A well-determined cross-section of the capture reaction in the low energy range is useful in nuclear physics due to its fundamental nature. The measurement is also of interest in cosmology. Big Bang Nucleosynthesis (BBN), the process by which light elements are formed in early universe, is very sensitive to the p(n,d γ) cross-section in the low energy range. The measurement enables us to put tighter constraints on the theoretical predictions of BBN. We have conducted preliminary measurements in the van de Graaff accelerator facility at the University of Kentucky. Our array of detectors consists of three plastic scintillators to serve as proton targets and deuteron detectors, and five BGO scintillators to detect γ-rays. The combination results in an over-determination of reaction kinematics that discriminates against scattering processes and other backgrounds. We have obtained some early results which show promise for the precise measurement of the p(n,d γ) cross-section.

  14. The energy of supernovae and the density of the interstellar medium

    NASA Astrophysics Data System (ADS)

    Sakhibov, F. Kh.; Smirnov, M. A.

    The density of the interstellar medium and the initial expansion energy (IEE) of a number of supernova remnants (SNRs) are calculated on a basis of a new list of calibration sources. Plerions and SNRs with a central source have practically the same IEE as shell SNRs, i.e., (2.6 + or - 0.5) x 10 to the 50th erg. An empirical relationship between the density of SNR optical filaments and shock velocity is obtained.

  15. Protonation energies of 1-5-ring polycyclic aromatic nitrogen heterocyclics: comparing experiment and theory.

    PubMed

    Wiseman, Alexander; Sims, Lacey A; Snead, Russell; Gronert, Scott; Maclagan, Robert G A R; Meot-Ner Mautner, Michael

    2015-01-01

    Polycyclic nitrogen heterocyclic compounds (PANHs) can be protonated in the gas phase in mass spectrometry, in solution in acidic and biological environments, and if present, in interstellar clouds. Intrinsic molecular effects on PANH basicities can be observed by their gas phase protonation thermochemistry. We determined the gas phase basicities/proton affinities (GBs/PAs) of prototype one-nitrogen, 3-5-ring PANH compounds of increasing sizes and polarizabilities by kinetic bracketing, using proton transfer reactions to reference bases. The experimental proton affinities increase from 1-ring (pyridine, 222.2); to 2-ring (quinoline, 227.8); to 3-5-ring compounds, 227-234 kcal mol(-1). We also calculated the GB/PA values at the M06-2X/6-311+G**//B3LYP/6-31g* level. The computed PAs agree, within the experimental uncertainty, with the experimental values anchored to the upper range of the NIST GB/PA database. Specifically, the computed PAs are smaller than the experimental values by 1.4 ± 0.9 kcal/mol for nonaromatic nitrogen reference bases and for 1-5-ring PANHs, independently of the number of rings, aromaticity, and molecular size. Therefore, a useful method to calculate proton affinities of PANH compounds can use M06-2X/6-311+G**//B3LYP/6-31g* computational PAs + 1.4 ± 0.9 kcal mol(-1). The agreement with experiment supports the NIST database within this accuracy, in the upper range up to 235 kcal mol(-1), even though there are no direct absolute experimental anchor points in this range. For astrochemical applications, the measured PAs allow calculating the energies of the (PANH)(+•) + H2 → (PANH)H(+) + H(•) reactions that may convert the radical ions to less reactive 11-electron ions. The reactions are endothermic or nearly thermoneutral for the 3-5-ring ions and would be very slow at low temperatures, allowing reactive (PANH)(+•) radical ions to persist in interstellar clouds.

  16. Proton Transport

    NASA Technical Reports Server (NTRS)

    Pohorille, Andrew; DeVincenzi, Donald L. (Technical Monitor)

    2001-01-01

    The transport of protons across membranes is an essential process for both bioenergetics of modern cells and the origins of cellular life. All living systems make use of proton gradients across cell walls to convert environmental energy into a high-energy chemical compound, adenosine triphosphate (ATP), synthesized from adenosine diphosphate. ATP, in turn, is used as a source of energy to drive many cellular reactions. The ubiquity of this process in biology suggests that even the earliest cellular systems were relying on proton gradient for harvesting environmental energy needed to support their survival and growth. In contemporary cells, proton transfer is assisted by large, complex proteins embedded in membranes. The issue addressed in this Study was: how the same process can be accomplished with the aid of similar but much simpler molecules that could have existed in the protobiological milieu? The model system used in the study contained a bilayer membrane made of phospholipid, dimyristoylphosphatidylcholine (DMPC) which is a good model of the biological membranes forming cellular boundaries. Both sides of the bilayer were surrounded by water which simulated the environment inside and outside the cell. Embedded in the membrane was a fragment of the Influenza-A M$_2$ protein and enough sodium counterions to maintain system neutrality. This protein has been shown to exhibit remarkably high rates of proton transport and, therefore, is an excellent model to study the formation of proton gradients across membranes. The Influenza M$_2$ protein is 97 amino acids in length, but a fragment 25 amino acids long. which contains a transmembrane domain of 19 amino acids flanked by three amino acids on each side. is sufficient to transport protons. Four identical protein fragments, each folded into a helix, aggregate to form small channels spanning the membrane. Protons are conducted through a narrow pore in the middle of the channel in response to applied voltage. This

  17. The low energy magnetic spectrometer on Ulysses and ACE response to near relativistic protons

    NASA Astrophysics Data System (ADS)

    Morgado, Bruno; Filipe Maia, Dalmiro Jorge; Lanzerotti, Louis; Gonçalves, Patrícia; Patterson, J. Douglas

    2015-05-01

    Aims: We show that the Heliosphere Instrument for Spectra Composition and Anisotropy at Low Energies (HISCALE) on board the Ulysses spacecraft and the Electron Proton Alpha Monitor (EPAM) on board the Advance Composition Explorer (ACE) spacecraft can be used to measure properties for ion populations with kinetic energies in excess of 1 GeV. This previously unexplored source of information is valuable for understanding the origin of near relativistic ions of solar origin. Methods: We model the instrumental response from the low energy magnetic spectrometers from EPAM and HISCALE using a Monte Carlo approach implemented in the Geant4 toolkit to determine the response of different energy channels to energies up to 5 GeV. We compare model results with EPAM observations for 2012 May 17 ground level solar cosmic ray event, including directional fluxes. Results: For the 2012 May event, all the ion channels in EPAM show an onset more than one hour before ions with the highest nominal energy range (1.8 to 4.8 MeV) were expected to arrive. We show from Monte Carlo simulations that the timing at different channels, the ratio between counts at the different channels, and the directional fluxes within a given channel, are consistent with and can be explained by the arrival of particles with energies from 35 MeV to more than 1 GeV. Onset times for the EPAM penetrating protons are consistent with the rise seen in neutron monitor data, implying that EPAM and ground neutron monitors are seeing overlapping energy ranges and that both are consistent with GeV ions being released from the Sun at 10:38 UT.

  18. Improved design of proton source and low energy beam transport line for European Spallation Source

    NASA Astrophysics Data System (ADS)

    Neri, L.; Celona, L.; Gammino, S.; Mascali, D.; Castro, G.; Torrisi, G.; Cheymol, B.; Ponton, A.; Galatà, A.; Patti, G.; Gozzo, A.; Lega, L.; Ciavola, G.

    2014-02-01

    The design update of the European Spallation Source (ESS) accelerator is almost complete and the construction of the prototype of the microwave discharge ion source able to provide a proton beam current larger than 70 mA to the 3.6 MeV Radio Frequency Quadrupole (RFQ) started. The source named PS-ESS (Proton Source for ESS) was designed with a flexible magnetic system and an extraction system able to merge conservative solutions with significant advances. The ESS injector has taken advantage of recent theoretical updates and new plasma diagnostics tools developed at INFN-LNS (Laboratori Nazionali del Sud, Istituto Nazionale di Fisica Nucleare). The design strategy considers the PS-ESS and the low energy beam transport line as a whole, where the proton beam behaves like an almost neutralized non-thermalized plasma. Innovative solutions have been used as hereinafter described. Thermo-mechanical optimization has been performed to withstand the chopped beam and the misaligned focused beam over the RFQ input collimator; the results are reported here.

  19. Improved design of proton source and low energy beam transport line for European Spallation Source.

    PubMed

    Neri, L; Celona, L; Gammino, S; Mascali, D; Castro, G; Torrisi, G; Cheymol, B; Ponton, A; Galatà, A; Patti, G; Gozzo, A; Lega, L; Ciavola, G

    2014-02-01

    The design update of the European Spallation Source (ESS) accelerator is almost complete and the construction of the prototype of the microwave discharge ion source able to provide a proton beam current larger than 70 mA to the 3.6 MeV Radio Frequency Quadrupole (RFQ) started. The source named PS-ESS (Proton Source for ESS) was designed with a flexible magnetic system and an extraction system able to merge conservative solutions with significant advances. The ESS injector has taken advantage of recent theoretical updates and new plasma diagnostics tools developed at INFN-LNS (Laboratori Nazionali del Sud, Istituto Nazionale di Fisica Nucleare). The design strategy considers the PS-ESS and the low energy beam transport line as a whole, where the proton beam behaves like an almost neutralized non-thermalized plasma. Innovative solutions have been used as hereinafter described. Thermo-mechanical optimization has been performed to withstand the chopped beam and the misaligned focused beam over the RFQ input collimator; the results are reported here.

  20. Improved design of proton source and low energy beam transport line for European Spallation Source

    SciTech Connect

    Neri, L. Celona, L.; Gammino, S.; Mascali, D.; Castro, G.; Ciavola, G.; Torrisi, G.; Cheymol, B.; Ponton, A.; Galatà, A.; Patti, G.; Gozzo, A.; Lega, L.

    2014-02-15

    The design update of the European Spallation Source (ESS) accelerator is almost complete and the construction of the prototype of the microwave discharge ion source able to provide a proton beam current larger than 70 mA to the 3.6 MeV Radio Frequency Quadrupole (RFQ) started. The source named PS-ESS (Proton Source for ESS) was designed with a flexible magnetic system and an extraction system able to merge conservative solutions with significant advances. The ESS injector has taken advantage of recent theoretical updates and new plasma diagnostics tools developed at INFN-LNS (Laboratori Nazionali del Sud, Istituto Nazionale di Fisica Nucleare). The design strategy considers the PS-ESS and the low energy beam transport line as a whole, where the proton beam behaves like an almost neutralized non-thermalized plasma. Innovative solutions have been used as hereinafter described. Thermo-mechanical optimization has been performed to withstand the chopped beam and the misaligned focused beam over the RFQ input collimator; the results are reported here.

  1. Investigation of charged-hadron production in proton-nucleus interactions at the energy of 50 GeV

    NASA Astrophysics Data System (ADS)

    Bordanovskii, A. Yu.; Volkov, A. A.; Elumahov, D. K.; Efremov, V. P.; Kalinin, A. Yu.; Korablev, A. V.; Krinitsyn, A. N.; Kryshkin, V. I.; Kulagin, N. V.; Skvortsov, V. V.; Talov, V. V.; Turchanovich, L. K.

    2016-07-01

    Cross sections for the production of high-transverse-momentum charged hadrons in proton-nucleus interactions at the incident-proton energy of 50 GeV were measured with the aid of the FODS double-arm spectrometer. Single hadrons (charged pions and protons) emitted at a c.m. angle of about 90° and high-effective-mass pairs of hadrons flying apart at a c.m. angle of 180° were detected simultaneously. Results on the production of single hadrons are presented.

  2. Binding Energies of Protonated Betaine Complexes: A Probe of Zwitterion Structure in the Gas Phase

    PubMed Central

    Price, William D.; Jockusch, Rebecca A.

    2005-01-01

    The dissociation kinetics of proton-bound dimers of betaine with molecules of comparable gas-phase basicity were investigated using blackbody infrared radiative dissociation (BIRD). Threshold dissociation energies were obtained from these data using master equation modeling. For bases that have comparable or higher gas-phase basicity, the binding energy of the protonated base·betaine complex is ~1.4 eV. For molecules that are ~2 kcal/mol or more less basic, the dissociation energy of the complexes is ~1.2 eV. The higher binding energy of the former is attributed to an ion–zwitterion structure which has a much larger ion–dipole interaction. The lower binding energy for molecules that are ~2 kcal/mol or more less basic indicates that an ion–molecule structure is more favored. Semiempirical calculations at both the AM1 and PM3 levels indicate the most stable ion–molecule structure is one in which the base interacts with the charged quaternary ammonium end of betaine. These results indicate that the measurement of binding energies of neutral molecules to biological ions could provide a useful probe for the presence of zwitterions and salt bridges in the gas phase. From the BIRD data, the gas-phase basicity of betaine obtained from the kinetic method is found to be 239.2 ± 1.0 kcal/mol. This value is in excellent agreement with the value of 239.3 kcal/mol (298 K) from ab initio calculations at the MP2/6-31+g** level. The measured value is slightly higher than those reported previously. This difference is attributed to entropy effects. The lower ion internal energy and longer time frame of BIRD experiments should provide values closer to those at standard temperature. PMID:16543945

  3. Utilization of industrial dairy waste as microalgae cultivation medium : a potential study for sustainable energy resources

    NASA Astrophysics Data System (ADS)

    Nurmayani, S.; Sugiarti, Y.; Putra, R. H.

    2016-04-01

    Microalgae is one of biodiesel resources and call as third generation biofuel. Biodiesel is one alternative energy that being developed. So study about resource of biodiesel need a development, for the example is development the basic material such as microalgae. In this paper we explain the potential use of dairy waste from industry as a cultivation medium of microalgae for biodiesel production. Dairy waste from dairy industry contains 34.98% protein, 4.42% lactose, 9.77% fiber, 11.04% fat, 2.33% calcium, 1.05% phosfor, and 0.4 % magnesium, meaning that the dairy waste from dairy industry has a relatively high nutrient content and complete from a source of carbon, nitrogen and phosphorus as macro nutrients. The method in this paper is literature review to resulting a new conclusion about the potency of waste water from dairy industry as microalgae cultivation medium. Based on the study, the dairy waste from dairy industry has potency to be used as cultivation medium of Botryococcus braunii in the production of biodiesel, replacing the conventional cultivation medium.

  4. Spatial resolution and nature of defects produced by low-energy proton irradiation of GaAs solar cells

    NASA Technical Reports Server (NTRS)

    Kachare, R.; Anspaugh, B. E.

    1986-01-01

    AlGaAs/GaAs solar cells with about 0.5-micron-thick Al(0.85)Ga(0.15)As window layers were irradiated using isotropic and normal incidence protons having energies between 50 and 500 keV with fluences up to 1 x 10 to the 12th protons/sq cm. Although the projected range for these protons varies from 0 to more than 4.5 microns, the recombination losses due to the irradiation-induced defects were observed to be maximum in the vicinity of the AlGaAs/GaAs interface and the space-charge region irrespective of the proton energy. This was found by analyzing spectral response measurements. The results are explained by using a model in which the interaction of as-grown dislocations with irradiation-induced point defects is considered.

  5. Absolute polarimeter for the proton-beam energy of 200 MeV

    SciTech Connect

    Zelenski, A. N.; Atoian, G.; Bogdanov, A. A.; Nurushev, S. B.; Pylaev, F. S.; Raparia, D.; Runtso, M. F.; Stephenson, E.

    2013-12-15

    A polarimeter is upgraded and tested in a 200-MeV polarized-proton beam at the accelerator-collider facility of the Brookhaven National Laboratory. The polarimeter is based on the elastic polarizedproton scattering on a carbon target at an angle of 16.2°, in which case the analyzing power is close to unity and was measured to a very high degree of precision. It is shown that, in the energy range of 190–205 MeV, the absolute polarization can be measured to a precision better than ±0.5%.

  6. Laser-foil acceleration of high-energy protons in small-scale plasma gradients.

    PubMed

    Fuchs, J; Cecchetti, C A; Borghesi, M; Grismayer, T; d'Humières, E; Antici, P; Atzeni, S; Mora, P; Pipahl, A; Romagnani, L; Schiavi, A; Sentoku, Y; Toncian, T; Audebert, P; Willi, O

    2007-07-01

    Proton beams laser accelerated from thin foils are studied for various plasma gradients on the foil rear surface. The beam maximum energy and spectral slope reduce with the gradient scale length, in good agreement with numerical simulations. The results also show that the jxB mechanism determines the temperature of the electrons driving the ion expansion. Future ion-driven fast ignition of fusion targets will use multikilojoule petawatt laser pulses, the leading part of which will induce target preheat. Estimates based on the data show that this modifies by less than 10% the ion beam parameters. PMID:17678159

  7. High-energy behavior of photon, neutrino, and proton cross sections

    NASA Astrophysics Data System (ADS)

    Argüelles, Carlos A.; Halzen, Francis; Wille, Logan; Kroll, Mike; Reno, Mary Hall

    2015-10-01

    By combining the color dipole model of the nucleon with the assumption that cross sections behave asymptotically as ln2(s ), we are able to describe the data for photon, neutrino and hadron interactions with protons at all energies; s is the center-of-mass energy of the interacting particles. Specifically, we extrapolate the perturbative QCD calculations into the regime of small fractional parton momenta x using a color dipole description of the proton target that guarantees an asymptotic ln2(s ) behavior of all cross sections. The ambiguity of introducing a parametrization associated with the dipole approximation is mitigated by the requirement that the saturation of the small-x structure functions produce ln2(s )-behaved asymptotic cross sections, in agreement with the data. The same formalism allows us to calculate the cross section for the hadronic pair production of charm particles. The results, in particular those for the high-energy neutrino and charm cross sections, are relevant for evaluating the sensitivity as well as the background in neutrino telescopes.

  8. Technical Support Document: Development of the Advanced Energy Design Guide for Medium to Big Box Retail Buildings - 50% Energy Savings

    SciTech Connect

    Bonnema, E.; Leach, M.; Pless, S.

    2013-06-01

    This Technical Support Document describes the process and methodology for the development of the Advanced Energy Design Guide for Medium to Big Box Retail Buildings: Achieving 50% Energy Savings Toward a Net Zero Energy Building (AEDG-MBBR) ASHRAE et al. (2011b). The AEDG-MBBR is intended to provide recommendations for achieving 50% whole-building energy savings in retail stores over levels achieved by following ANSI/ASHRAE/IESNA Standard 90.1-2004, Energy Standard for Buildings Except Low-Rise Residential Buildings (Standard 90.1-2004) (ASHRAE 2004b). The AEDG-MBBR was developed in collaboration with the American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE), the American Institute of Architects (AIA), the Illuminating Engineering Society of North America (IES), the U.S. Green Building Council (USGBC), and the U.S. Department of Energy.

  9. Technical Support Document: Development of the Advanced Energy Design Guide for Medium to Big Box Retail Buildings - 50% Energy Savings

    SciTech Connect

    Bonnema, Eric; Leach, Matt; Pless, Shanti

    2013-06-05

    This Technical Support Document describes the process and methodology for the development of the Advanced Energy Design Guide for Medium to Big Box Retail Buildings: Achieving 50% Energy Savings Toward a Net Zero Energy Building (AEDG-MBBR) ASHRAE et al. (2011b). The AEDG-MBBR is intended to provide recommendations for achieving 50% whole-building energy savings in retail stores over levels achieved by following ANSI/ASHRAE/IESNA Standard 90.1-2004, Energy Standard for Buildings Except Low-Rise Residential Buildings (Standard 90.1-2004) (ASHRAE 2004b). The AEDG-MBBR was developed in collaboration with the American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE), the American Institute of Architects (AIA), the Illuminating Engineering Society of North America (IES), the U.S. Green Building Council (USGBC), and the U.S. Department of Energy.

  10. Storm time dynamics of ring current protons: Implications for the long-term energy budget in the inner magnetosphere

    NASA Astrophysics Data System (ADS)

    Gkioulidou, Matina; Ukhorskiy, A. Y.; Mitchell, D. G.; Lanzerotti, L. J.

    2016-05-01

    Our investigation of the long-term ring current proton pressure evolution in Earth's inner magnetosphere based on Van Allen Probes data shows drastically different behavior of the low- and high- energy components of the ring current proton population with respect to the SYM-H index variation. We found that while the low-energy component of the protons (<80 keV) is strongly governed by convective timescales and is very well correlated with the absolute value of SYM-H index, the high-energy component (>100 keV) varies on much longer timescales and shows either no correlation or anticorrelation with the absolute value of SYM-H index. Our study also shows that the contributions of the low- and high- energy protons to the inner magnetosphere energy content are comparable. Thus, our results conclusively demonstrate that proton dynamics, and as a result the energy budget in the inner magnetosphere, do not vary strictly on storm time timescales as those are defined by the SYM-H index.

  11. Development of a Telescope for Medium-Energy Gamma-Ray Astronomy

    NASA Technical Reports Server (NTRS)

    Hunter, Stanley D.

    2010-01-01

    Since the launch of AGILE and FERMI, the scientific progress in high-energy (E(sub gamma) greater than approximately 200 MeV) gamma-ray science has been, and will continue to be dramatic. Both of these telescopes cover a broad energy range from approximately 20 MeV to greater than 10 GeV. However, neither instrument is optimized for observations below approximately 200 MeV where many astrophysical objects exhibit unique, transitory behavior, such as spectral breaks, bursts, and flares. Hence, while significant progress from current observations is expected, there will nonetheless remain a significant sensitivity gap in the medium-energy (approximately 0.1-200 MeV) regime; the lower end of this range remains largely unexplored whereas the upper end will allow comparison with FERMI data. Tapping into this unexplored regime requires significant improvements in sensitivity. A major emphasis of modern detector development, with the goal of providing significant improvements in sensitivity in the medium-energy regime, focuses on high-resolution electron tracking. The Three-Dimensional Track Imager (3-DTI) technology being developed at GSFC provides high resolution tracking of the electron-positron pair from gamma-ray interactions from 5 to 200 MeV. The 3-DTI consists of a time projection chamber (TPC) and 2-D cross-strip microwell detector (MWD). The low-density and homogeneous design of the 3-DTI, offers unprecedented sensitivity by providing angular resolution near the kinematic limit. Electron tracking also enables measurement of gamma-ray polarization, a new tool to study astrophysical phenomenon. We describe the design, fabrication, and performance of a 30x30x30 cubic centimeters 3-DTI detector prototype of a medium-energy gamma-ray telescope.

  12. Development of a Telescope for Medium-Energy Gamma-ray Astronomy

    NASA Technical Reports Server (NTRS)

    Sunter, Stan

    2012-01-01

    Since the launch of AGILE and FERMI, the scientific progress in high-energy (Eg greater than approximately 200 MeV) gamma-ray science has been, and will continue to be dramatic. Both of these telescopes cover a broad energy range from approximately 20 MeV to greater than 10 GeV. However, neither instrument is optimized for observations below approximately 200 MeV where many astrophysical objects exhibit unique, transitory behavior, such as spectral breaks, bursts, and flares. Hence, while significant progress from current observations is expected, there will nonetheless remain a significant sensitivity gap in the medium-energy (approximately 0.1-200 MeV) regime; the lower end of this range remains largely unexplored whereas the upper end will allow comparison with FERMI data. Tapping into this unexplored regime requires significant improvements in sensitivity. A major emphasis of modern detector development, with the goal of providing significant improvements in sensitivity in the medium-energy regime, focuses on high-resolution electron tracking. The Three-Dimensional Track Imager (3-DTI) technology being developed at GSFC provides high resolution tracking of the electron-positron pair from gamma-ray interactions from 5 to 200 MeV. The 3-DTI consists of a time projection chamber (TPC) and 2-D cross-strip microwell detector (MWD). The low-density and homogeneous design of the 3-DTI, offers unprecedented sensitivity by providing angular resolution near the kinematic limit. Electron tracking also enables measurement of gamma-ray polarization, a new tool to study astrophysical phenomenon. We describe the design, fabrication, and performance of a 30x30x30 cm3 3-DTI detector prototype of a medium-energy gamma-ray telescope.

  13. New constraints from PAMELA anti-proton data on annihilating and decaying dark matter

    SciTech Connect

    Cholis, Ilias

    2011-09-01

    Recently the PAMELA experiment has released its updated anti-proton flux and anti-proton to proton flux ratio data up to energies of ≈ 200GeV. With no clear excess of cosmic ray anti-protons at high energies, one can extend constraints on the production of anti-protons from dark matter. In this letter, we consider both the cases of dark matter annihilating and decaying into standard model particles that produce significant numbers of anti-protons. We provide two sets of constraints on the annihilation cross-sections/decay lifetimes. In the one set of constraints we ignore any source of anti-protons other than dark matter, which give the highest allowed cross-sections/inverse lifetimes. In the other set we include also anti-protons produced in collisions of cosmic rays with interstellar medium nuclei, getting tighter but more realistic constraints on the annihilation cross-sections/decay lifetimes.

  14. Energy loss of MeV protons specularly reflected from metal surfaces

    SciTech Connect

    Juaristi, J.I.

    1996-05-01

    A parameter-free model is presented to study the energy loss of fast protons specularly reflected from metal surfaces. The contributions to the energy loss from excitation of valence-band electrons and ionization of localized target-atom electronic states are calculated separately. The former is calculated from the induced surface wake potential using linear response theory and the specular-reflection model, while the latter is calculated in the first Born approximation. The results obtained are in good agreement with available experimental data. However, the experimental qualitative trend of the energy loss as a function of the angle of incidence is obtained when the valence-band electron model is replaced by localized target atom electron states, though with a worse quantitative agreement. {copyright} {ital 1996 The American Physical Society.}

  15. RF System Requirements for a Medium-Energy Electron-Ion Collider (MEIC) at JLab

    SciTech Connect

    Rimmer, Robert A; Hannon, Fay E; Guo, Jiquan; Huang, Shichun; Huang, Yulu; Wang, Haipeng; Wang, S

    2015-09-01

    JLab is studying options for a medium energy electron-ion collider that could fit on the JLab site and use CEBAF as a full-energy electron injector. A new ion source, linac and booster would be required, together with collider storage rings for the ions and electrons. In order to achieve the maximum luminosity these will be high-current storage rings with many bunches. We present the high-level RF system requirements for the storage rings, ion booster ring and high-energy ion beam cooling system, and describe the technology options under consideration to meet them. We also present options for staging that might reduce the initial capital cost while providing a smooth upgrade path to a higher final energy. The technologies under consideration may also be useful for other proposed storage ring colliders or ultimate light sources.

  16. Response functions of Fuji imaging plates to monoenergetic protons in the energy range 0.6-3.2 MeV

    SciTech Connect

    Bonnet, T.; Denis-Petit, D.; Gobet, F.; Hannachi, F.; Tarisien, M.; Versteegen, M.; Aleonard, M. M.

    2013-01-15

    We have measured the responses of Fuji MS, SR, and TR imaging plates (IPs) to protons with energies ranging from 0.6 to 3.2 MeV. Monoenergetic protons were produced with the 3.5 MV AIFIRA (Applications Interdisciplinaires de Faisceaux d'Ions en Region Aquitaine) accelerator at the Centre d'Etudes Nucleaires de Bordeaux Gradignan (CENBG). The IPs were irradiated with protons backscattered off a tantalum target. We present the photo-stimulated luminescence response of the IPs together with the fading measurements for these IPs. A method is applied to allow correction of fading effects for variable proton irradiation duration. Using the IP fading corrections, a model of the IP response function to protons was developed. The model enables extrapolation of the IP response to protons up to proton energies of 10 MeV. Our work is finally compared to previous works conducted on Fuji TR IP response to protons.

  17. Heat deposition in thick targets due to interaction of high energy protons and thermal hydraulics analysis

    NASA Astrophysics Data System (ADS)

    Kumawat, H.; Dutta, D.; Mantha, V.; Mohanty, A. K.; Satyamurthy, P.; Choudhury, R. K.; Kailas, S.

    2008-02-01

    Heat deposition inside thick targets due to interaction of high energy protons (Ep ∼ GeV) has been estimated using an improved version of the Monte Carlo simulation code CASCADE.04.h. The results are compared with the available experimental data for thick targets of Be, Al, Fe, Cu, Pb and Bi at proton energies of 0.8 GeV, 1.0 GeV and 1.2 GeV. A more continuous heat deposition approach which has been adopted in CASCADE.04.h yields results which are in better agreement with the experimental data as compared to the ones from the earlier version of CASCADE.04. The results are also compared with the predictions of the FLUKA Monte Carlo code. Both CASCADE.04.h and FLUKA predictions are nearly similar for heavy targets and both agree with the experimental measurements. However, they do have differences in predictions for lighter targets where measurements also differ from the predictions. It is observed that the maximum heat loss in thick targets occurs at the beginning of the target due to increasing nuclear reaction contributions. This aspect is crucial in designing the window of a spallation neutron target employed in an accelerator driven sub-critical system (ADS) as this is the first material to be traversed by the proton beam and is subjected to the maximum temperature gradient. Optimization of the target-window parameters requires a careful estimation of heat deposition in the window region and this has been demonstrated through thermal hydraulic studies related to the design of a realistic lead bismuth eutectic (LBE) spallation neutron target for an ADS system.

  18. Absolute calibration of photostimulable image plate detectors used as (0.5-20 MeV) high-energy proton detectors.

    PubMed

    Mancić, A; Fuchs, J; Antici, P; Gaillard, S A; Audebert, P

    2008-07-01

    In this paper, the absolute calibration of photostimulable image plates (IPs) used as proton detectors is presented. The calibration is performed in a wide range of proton energies (0.5-20 MeV) by exposing simultaneously the IP and calibrated detectors (radiochromic films and solid state detector CR39) to a source of broadband laser-accelerated protons, which are spectrally resolved. The final result is a calibration curve that enables retrieving the proton number from the IP signal. PMID:18681694

  19. Advanced Energetic Pair Telescope (AdEPT), a Medium-Energy Gamma-Ray Polarimeter

    NASA Astrophysics Data System (ADS)

    Hunter, Stanley; AdEPT Collaboration

    2015-04-01

    Since the launch of AGILE and FERMI, the scientific progress in high-energy (Eγ > 200MeV) gamma-ray science has been dramatic. Both of these telescopes cover a broad energy range from about ~ 20 MeV to > 10 GeV. However, a significant sensitivity gap remains in the medium-energy regime (0.75 - 200 MeV) that has been explored only by COMPTEL and EGRET on CGRO. Exploring this regime with angular resolution near the kinematic limit and high polarization sensitivity requires a telescope design with a low density electron track imaging detector. The medium-energy (~ 5 to 200 MeV) Advanced Energetic Pair Telescope (AdEPT), will achieve angular resolution of ~0.6 deg at 70 MeV, similar to the angular resolution of Fermi/LAT at ~ 1 GeV. AdEPT will also provide unprecedented polarization sensitivity of ~ 1 % for a 1 Crab source. The enabling technology for AdEPT is the Three-Dimensional Track Imager (3-DTI) a low-density, large volume, gas time-projection chamber with a 2-dimensional readout. We describe our ROSES/APRA funded program to build a 50x50x100 cm3 AdEPT prototype, measure the angular resolution and polarization sensitivity of this prototype at an accelerator.

  20. Production of Actinium-225 via High Energy Proton Induced Spallation of Thorium-232

    SciTech Connect

    Harvey, James T.; Nolen, Jerry; Vandergrift, George; Gomes, Itacil; Kroc, Tom; Horwitz, Phil; McAlister, Dan; Bowers, Del; Sullivan, Vivian; Greene, John

    2011-12-30

    The science of cancer research is currently expanding its use of alpha particle emitting radioisotopes. Coupled with the discovery and proliferation of molecular species that seek out and attach to tumors, new therapy and diagnostics are being developed to enhance the treatment of cancer and other diseases. This latest technology is commonly referred to as Alpha Immunotherapy (AIT). Actinium-225/Bismuth-213 is a parent/daughter alpha-emitting radioisotope pair that is highly sought after because of the potential for treating numerous diseases and its ability to be chemically compatible with many known and widely used carrier molecules (such as monoclonal antibodies and proteins/peptides). Unfortunately, the worldwide supply of actinium-225 is limited to about 1,000mCi annually and most of that is currently spoken for, thus limiting the ability of this radioisotope pair to enter into research and subsequently clinical trials. The route proposed herein utilizes high energy protons to produce actinium-225 via spallation of a thorium-232 target. As part of previous R and D efforts carried out at Argonne National Laboratory recently in support of the proposed US FRIB facility, it was shown that a very effective production mechanism for actinium-225 is spallation of thorium-232 by high energy proton beams. The base-line simulation for the production rate of actinium-225 by this reaction mechanism is 8E12 atoms per second at 200 MeV proton beam energy with 50 g/cm2 thorium target and 100 kW beam power. An irradiation of one actinium-225 half-life (10 days) produces {approx}100 Ci of actinium-225. For a given beam current the reaction cross section increases slightly with energy to about 400 MeV and then decreases slightly for beam energies in the several GeV regime. The object of this effort is to refine the simulations at proton beam energies of 400 MeV and above up to about 8 GeV. Once completed, the simulations will be experimentally verified using 400 MeV and 8 Ge

  1. Probing Higgs boson self-interactions in proton-proton collisions at a center-of-mass energy of 100 TeV

    NASA Astrophysics Data System (ADS)

    Fuks, Benjamin; Kim, Jeong Han; Lee, Seung J.

    2016-02-01

    We present a phenomenological study of triple-Higgs production in which we estimate the prospects for measuring the form of the Higgs potential at future circular collider projects. We analyze proton-proton collisions at a center-of-mass energy of 100 TeV and focus on two different signatures in which the final state is made of four b jets and either a pair of photons or a pair of tau leptons. We study the resulting sensitivity on the Higgs cubic and quartic self-interactions and investigate how it depends on the b -tagging, tau-tagging and photon-resolution performances of detectors that could be designed for these future machines. We then discuss possible luminosity goals for future 100 TeV collider projects that would allow for a measurement of the Higgs potential and its possible departures from the Standard Model expectation.

  2. Proton-induced fragmentation of carbon at energies below 100 MeV

    NASA Technical Reports Server (NTRS)

    Schmitz, M.; Streibel, T.; Roecher, H.; Dreute, J.; Hirzebruch, S. E.; Huentrup, G.; Heinrich, Wolfgang

    1994-01-01

    Radiation effects caused by single cosmic ray particles have been studied for many years in radiobiological experiments for different biological objects and biological end-points. Additionally, single event effects in microelectronic devices have gained large interest. There are two fundamental mechanisms by which a single particle can cause radiation effects. On the one hand, a cosmic ray ion with high linear energy transfer can deposit a high dose along its path. On the other hand, in a nuclear collision, a high dose can be deposited by short range particles emitted from the target nucleus. In low earth orbits a large contribution to target fragmentation events originates from trapped protons which are encountered in the South Atlantic Anomaly. These protons have energies up to a few hundred MeV. We study the fragmentation of C, O and Si nuclei - the target nuclei of biological material and microelectronic devices - in nuclear collisions. Our aim is to measure production cross sections, energy spectra, emission directions and charge correlations of the emitted fragments. The present knowledge concerning these data is rather poor. M. Alurralde et al. have calculated cross sections and average energies of fragments produced from Si using the cascade-evaporation model. D.M. Ngo et al. have used the semiempirical cross section formula of Silberberg and Tsao to calculate fragment yields and the statistical model of Goldhaber to describe the reaction kinematics. Cross sections used in these models have uncertainties within a factor of two. Our data will help to test and improve existing models especially for energies below 300 MeV/nucleon. Charge correlations of fragments emitted in the same interaction are of particular importance, since high doses can be deposited if more than one heavy fragment with a short range is produced.

  3. Association of Proton Pump Inhibitor (PPI) Use with Energy Intake, Physical Activity, and Weight Gain

    PubMed Central

    Czwornog, Jennifer L.; Austin, Gregory L.

    2015-01-01

    Studies suggest proton pump inhibitor (PPI) use impacts body weight regulation, though the effect of PPIs on energy intake, energy extraction, and energy expenditure is unknown. We used data on 3073 eligible adults from the National Health and Nutrition Examination Survey (NHANES). Medication use, energy intake, diet composition, and physical activity were extracted from NHANES. Multivariate regression models included confounding variables. Daily energy intake was similar between PPI users and non-users (p = 0.41). Diet composition was similar between the two groups, except that PPI users consumed a slightly greater proportion of calories from fat (34.5% vs. 33.2%; p = 0.02). PPI users rated themselves as being as physically active as their age/gender-matched peers and reported similar frequencies of walking or biking. However, PPI users were less likely to have participated in muscle-strengthening activities (OR: 0.53; 95% CI: 0.30–0.95). PPI users reported similar sedentary behaviors to non-users. Male PPI users had an increase in weight (of 1.52 ± 0.59 kg; p = 0.021) over the previous year compared to non-users, while female PPI users had a non-significant increase in weight. The potential mechanisms for PPI-associated weight gain are unclear as we did not find evidence for significant differences in energy intake or markers of energy expenditure. PMID:26492268

  4. Energy compensation mechanism for charge-separated protonation states in aspartate-histidine amino acid residue pairs.

    PubMed

    Kamiya, Katsumasa; Boero, Mauro; Shiraishi, Kenji; Oshiyama, Atsushi; Shigeta, Yasuteru

    2010-05-20

    The initial stage of proton propagation in the D-path channel of bovine cytochrome c oxidase, consisting of the approach of an H(+) to the entrance of this specific pathway, is inspected via first-principles calculations. Our model, extracted from the X-ray crystallographic structure, includes the amino acid residue pair aspartate (Asp91) and histidine (His503) as protonatable sites. Our calculations show that an additional proton, corresponding to the H(+) uptake by the enzyme from the inner bulk water, is transferred to either Asp91 or His503, leading to the formation of a neutral or a charge-separated protonation state. The relative stability between the two states amounts to a total energy difference of about 5 kcal/mol; this indicates that both Asp91 and His503 are involved in the proton supply to the D-path, playing the role of proton acceptors. The hydrogen-bond environment around Asp91 and His503 has an important influence on both the energetics and the electronic structure of the system; for instance, it compensates the Coulomb-energy cost in the charge-separated protonation state. An energy partitioning analysis shows that the compensatory effect is mainly due to local electrostatic interactions among the charged Asp91 and His503 side chains and the surrounding polar residues. The energy compensation mechanism we found in this work balances the energetics of Asp-His pairs, hence permitting an efficient and selective regulation of the protonatable amino acid residues, where several protonation states are accessible within energy differences of the order of a few H-bonds. PMID:20411975

  5. Synchrotron based proton drivers

    SciTech Connect

    Weiren Chou

    2002-09-19

    Proton drivers are the proton sources that produce intense short proton bunches. They have a wide range of applications. This paper discusses the proton drivers based on high-intensity proton synchrotrons. It gives a review of the high-intensity proton sources over the world and a brief report on recent developments in this field in the U.S. high-energy physics (HEP) community. The Fermilab Proton Driver is used as a case study for a number of challenging technical design issues.

  6. Spin observables in inelastic proton-nucleus scattering at intermediate energy

    SciTech Connect

    Smith, R.D.

    1984-01-01

    This dissertation is a study of spin observables in inelastic proton-nucleus reactions for incident proton energies near 1 GeV. At this energy, the dominant reaction mechanisms are (1) quasi-free knockout of one or more nucleons, and (2) pion production through the resonance. The cross section due to quasi-free knockout can be reasonably well understood theoretically in a multiple scattering picture, which uses measured NN amplitudes as input. Calculations of this sort were carried out in reference (10) using scalar NN amplitudes parameterized as Gaussians. The author has extended this picture to include spin dependent NN amplitudes. This allows calculation of all the spin observables, Ay, DLL, DSS, DNN, DLS, and DSL, as well as the cross section dsigma/dOmegadp due to quasi-free knockout of one or more particles. The cross section and polarization Ay have been measured at the LAMPF High Resolution Spectrometer at T/sub L/ = 800 MeV on SC. The theoretical results agree well with the data in the quasi-free region. The results for the remaining spin observables provide predictions for experiments which can be performed at LAMPF. By comparing the calculations with the data, it may be possible to separate the contribution due to a quasi-free knockout, and see a signature of quasi-free production in the spin observables.

  7. Isochoric heating of matter by laser-accelerated high-energy protons

    NASA Astrophysics Data System (ADS)

    Fuchs, Julien; Mancic, Ana; Robiche, Jerome; Antici, Patrizio; Lancia, Livia; Audebert, Patrick; Combis, Patrick; Renaudin, Patrick; Kimura, Tomoaki; Kodama, Ryosuke; Nakatsutsumi, Motoaki

    2008-04-01

    Producing matter at a high temperature (1-25 eV) and solid density is of prime interest for fundamental plasma physics or ICF. The use of laser-based high energy proton beams to achieve such state of matter is interesting since they are short (< 1 ps) and they deposit their energy volumetrically; thus can heat, before they expand, much thicker samples than allowed using laser-heating. We performed, using two intense short pulses of the LULI 100 TW facility, experiments to characterize the achieved state of matter, coupled to a detailed hydro-modeling. A laser-generated proton beam irradiated and heated a secondary target positioned after a vacuum gap. Three diagnostics were used: (i) 1D time-resolved optical self-emission of the heated target rear-surface at two wavelengths, (ii) time-resolved interferometry of a chirped probe beam reflecting off the heated target rear-surface, (iii) x-ray absorption spectroscopy through the heated target using a laser-produced backlighter detecting its Kα-edge softening.

  8. Long-term residual radioactivity in an intermediate-energy proton linac

    NASA Astrophysics Data System (ADS)

    Blaha, J.; La Torre, F. P.; Silari, M.; Vollaire, J.

    2014-07-01

    A new 160 MeV H- linear accelerator (LINAC4) is being installed at CERN to replace the present 50 MeV LINAC2 as proton injector of the PS Booster (PSB). During operation, the accelerator components will be activated by the beam itself and by the secondary radiation field. Detailed Monte Carlo simulations, for various beam energies and several decay times, were performed to predict the residual radioactivity in the main accelerator components and to estimate the residual dose rate inside the tunnel. The results of this study will facilitate future dismantling, handling and storage of the activated parts and consequently minimize the radiation dose to involved workers. The component activation was also compared with the exemption limits given in the current Swiss legislation and to the CERN design values, in order to make predictions for the future storage and disposal of radioactive waste. The airborne radioactivity induced by particles escaping the beam dump and the activation of the beam dump cooling water circuit were also quantified. The aim of this paper is to provide data of sufficiently general interest to be used for similar studies at other intermediate-energy proton accelerator facilities.

  9. Studying Proton-Proton Collisions Using Pythia

    NASA Astrophysics Data System (ADS)

    Zolotov, Adi

    2004-10-01

    At Brookhaven National Lab, the RHIC experiments are currently investigating, on a subatomic level, what happens when heavy ions collide at high speeds. This is done in order to create such high temperatures and densities that quarks are no longer bound to one another. This state of matter is called the Quark-Gluon Plasma (QGP). Evidence for the existence of the QGP may be the quenching of hadron jets, which occurs when the fast quarks or gluons lose so much energy in the hot, dense medium that they cannot survive. Then the jets of particles that these particles usually result in cannot be made. By studying the particle yield at high transverse momentum (Pt), one can probe what is happening to the jets created during collisions. Using Pythia, a standard model event generator based on the Lund String Model, we study jets of particles created when elementary protons collide. Then we know what should happen to jets at high transverse momentum transfer, when no QGP is present. Comparing the pt spectrum of jet partners generated by Pythia to RHIC results for proton-proton collisions shows that the two do in fact agree. This not only insures that the analysis of RHIC data is correct, but it also establishes a basis for comparison for Au-Au collisions. Comparing d+Au collision data to the Pythia Pt spectrum of jets with leading baryon and meson triggers, we found good agreement. Thus the jet production does not change drastically in nature in the presence of a cold nuclear medium.

  10. Summary of low-energy aspects of QCD and medium-energy hadron parallel sessions

    SciTech Connect

    McClelland, J.B.

    1991-01-01

    Two sessions were organized dealing with low energy aspects of QCD. The first dealt with the issue of QCD dibaryons. The second session centered on mostly low-energy tests of QCD. This report discusses experiments dealing with these sessions.

  11. Observations of medium-energy gamma-ray emission from the galactic center region

    NASA Technical Reports Server (NTRS)

    Kniffen, D. A.; Bertsch, D. L.; Morris, D. J.; Palmeira, R. A. R.; Rao, K. R.

    1978-01-01

    Measurements of the gamma-ray emission in the medium-energy range between 15 and 100 MeV, obtained during two balloon flights from Brazil, are presented. The importance of this energy region in determining whether neutral-pion decay or electron bremsstrahlung is the most likely dominant source mechanism is discussed, along with the implications of such observations. Specifically, the data from this experiment suggest that emission from the galactic plane is similar to the theoretical spectrum calculated by Fichtel et al. (1976), including both source mechanisms but with the bremsstrahlung component enhanced by a factor of about 2. A spectral distribution of gamma-rays produced in the residual atmosphere above the instrument is also presented and compared with other data. A rather smooth spectral variation from high to low energies is found for the atmospheric spectrum.

  12. Observations of medium energy gamma ray emission from the galactic center region

    NASA Technical Reports Server (NTRS)

    Kniffen, D. A.; Bertsch, D. L.; Morris, D. J.; Palmeira, R. A. R.; Rao, K. R.

    1978-01-01

    Measurements of the gamma-ray emission in the medium energy range between 15 and 100 MeV, obtained during two ballon flights from Brazil are presented. The importance of this energy region in determining whether pi deg - decay of electron bremsstrahlung is the most likely dominant source mechanism is discussed along with the implications of such observations. Specifically, the data from this experiment suggest that emission from the galactic plane is similar to theoretical spectrum calculations including both sources mechanisms, but with the bremsstrahlung component enhanced by a factor of about 2. A spectral distribution of gamma-rays produced in the residual atmosphere above the instrument is also presented and compared with other data. A rather smooth spectral variation from high to low energies is found for the atmospheric spectrum.

  13. A Time Tree Medium Access Control for Energy Efficiency and Collision Avoidance in Wireless Sensor Networks

    PubMed Central

    Lee, Kilhung

    2010-01-01

    This paper presents a medium access control and scheduling scheme for wireless sensor networks. It uses time trees for sending data from the sensor node to the base station. For an energy efficient operation of the sensor networks in a distributed manner, time trees are built in order to reduce the collision probability and to minimize the total energy required to send data to the base station. A time tree is a data gathering tree where the base station is the root and each sensor node is either a relaying or a leaf node of the tree. Each tree operates in a different time schedule with possibly different activation rates. Through the simulation, the proposed scheme that uses time trees shows better characteristics toward burst traffic than the previous energy and data arrival rate scheme. PMID:22319270

  14. State-Selective Capture Cross Sections in Proton-Hydrogen and Proton-Helium Collisions at Intermediate and High Energies

    NASA Astrophysics Data System (ADS)

    Belkic, Dzevad

    1989-01-01

    Total cross sections are computed for electron capture from the ground states of H and He by fast protons using the Corrected first-Born (CB1) approximation. Particular emphasis is given to the formation of atomic hydrogen in excited states 2s, 2p, 3s, 3p, 3d and 4s for which experimental data are available. Detailed comparisons with the measurements are carried out, with the purpose of assessing the validity and utility of the CB1 method for prediction of state-selective cross sections.

  15. Dosimetric characteristics of four PTW microDiamond detectors in high-energy proton beams.

    PubMed

    Marsolat, F; De Marzi, L; Patriarca, A; Nauraye, C; Moignier, C; Pomorski, M; Moignau, F; Heinrich, S; Tromson, D; Mazal, A

    2016-09-01

    Small diamond detectors are useful for the dosimetry of high-energy proton beams. However, linear energy transfer (LET) dependence has been observed in the literature with such solid state detectors. A novel synthetic diamond detector has recently become commercially available from the manufacturer PTW-Freiburg (PTW microDiamond type 60019). This study was designed to thoroughly characterize four microDiamond detectors in clinical proton beams, in order to investigate their response and their reproducibility in high LET regions. Very good dosimetric characteristics were observed for two of them, with good stability of their response (deviation less than 0.4% after a pre-irradiation dose of approximately 12 Gy), good repeatability (coefficient of variation of 0.06%) and a sensitivity of approximately 0.85 nC Gy(-1). A negligible dose rate dependence was also observed for these two microDiamonds with a deviation of the sensitivity less than 0.7% with respect to the one measured at the reference dose rate of 2.17 Gy min(-1), in the investigated dose rate range from 1.01 Gy min(-1) to 5.52 Gy min(-1). Lateral dose profile measurements showed the high spatial resolution of the microDiamond oriented with its stem perpendicular to the beam axis and with its small sensitive thickness of about 1 μm in the scanning profile direction. Finally, no significant LET dependence was found with these two diamond dosimeters in comparison to a reference ionization chamber (model IBA PPC05). These good results were in accordance to the literature. However, this study showed also a non reproducibility between the devices in terms of stability, sensitivity and LET dependence, since the two other microDiamonds characterized in this work showed different dosimetric characteristics making them not suitable for proton beam dosimetry with a maximum difference of the peak-to-plateau ratio of 6.7% relative to the reference ionization chamber in a clinical 138 MeV proton beam. PMID:27499356

  16. Dosimetric characteristics of four PTW microDiamond detectors in high-energy proton beams

    NASA Astrophysics Data System (ADS)

    Marsolat, F.; De Marzi, L.; Patriarca, A.; Nauraye, C.; Moignier, C.; Pomorski, M.; Moignau, F.; Heinrich, S.; Tromson, D.; Mazal, A.

    2016-09-01

    Small diamond detectors are useful for the dosimetry of high-energy proton beams. However, linear energy transfer (LET) dependence has been observed in the literature with such solid state detectors. A novel synthetic diamond detector has recently become commercially available from the manufacturer PTW-Freiburg (PTW microDiamond type 60019). This study was designed to thoroughly characterize four microDiamond detectors in clinical proton beams, in order to investigate their response and their reproducibility in high LET regions. Very good dosimetric characteristics were observed for two of them, with good stability of their response (deviation less than 0.4% after a pre-irradiation dose of approximately 12 Gy), good repeatability (coefficient of variation of 0.06%) and a sensitivity of approximately 0.85 nC Gy‑1. A negligible dose rate dependence was also observed for these two microDiamonds with a deviation of the sensitivity less than 0.7% with respect to the one measured at the reference dose rate of 2.17 Gy min‑1, in the investigated dose rate range from 1.01 Gy min‑1 to 5.52 Gy min‑1. Lateral dose profile measurements showed the high spatial resolution of the microDiamond oriented with its stem perpendicular to the beam axis and with its small sensitive thickness of about 1 μm in the scanning profile direction. Finally, no significant LET dependence was found with these two diamond dosimeters in comparison to a reference ionization chamber (model IBA PPC05). These good results were in accordance to the literature. However, this study showed also a non reproducibility between the devices in terms of stability, sensitivity and LET dependence, since the two other microDiamonds characterized in this work showed different dosimetric characteristics making them not suitable for proton beam dosimetry with a maximum difference of the peak-to-plateau ratio of 6.7% relative to the reference ionization chamber in a clinical 138 MeV proton beam.

  17. Dosimetric characteristics of four PTW microDiamond detectors in high-energy proton beams

    NASA Astrophysics Data System (ADS)

    Marsolat, F.; De Marzi, L.; Patriarca, A.; Nauraye, C.; Moignier, C.; Pomorski, M.; Moignau, F.; Heinrich, S.; Tromson, D.; Mazal, A.

    2016-09-01

    Small diamond detectors are useful for the dosimetry of high-energy proton beams. However, linear energy transfer (LET) dependence has been observed in the literature with such solid state detectors. A novel synthetic diamond detector has recently become commercially available from the manufacturer PTW-Freiburg (PTW microDiamond type 60019). This study was designed to thoroughly characterize four microDiamond detectors in clinical proton beams, in order to investigate their response and their reproducibility in high LET regions. Very good dosimetric characteristics were observed for two of them, with good stability of their response (deviation less than 0.4% after a pre-irradiation dose of approximately 12 Gy), good repeatability (coefficient of variation of 0.06%) and a sensitivity of approximately 0.85 nC Gy-1. A negligible dose rate dependence was also observed for these two microDiamonds with a deviation of the sensitivity less than 0.7% with respect to the one measured at the reference dose rate of 2.17 Gy min-1, in the investigated dose rate range from 1.01 Gy min-1 to 5.52 Gy min-1. Lateral dose profile measurements showed the high spatial resolution of the microDiamond oriented with its stem perpendicular to the beam axis and with its small sensitive thickness of about 1 μm in the scanning profile direction. Finally, no significant LET dependence was found with these two diamond dosimeters in comparison to a reference ionization chamber (model IBA PPC05). These good results were in accordance to the literature. However, this study showed also a non reproducibility between the devices in terms of stability, sensitivity and LET dependence, since the two other microDiamonds characterized in this work showed different dosimetric characteristics making them not suitable for proton beam dosimetry with a maximum difference of the peak-to-plateau ratio of 6.7% relative to the reference ionization chamber in a clinical 138 MeV proton beam.

  18. Variations in lithium target thickness and proton energy stability for the near-threshold 7Li(p,n)7Be accelerator-based BNCT.

    PubMed

    Kobayashi, Tooru; Bengua, Gerard; Tanaka, Kenichi; Nakagawa, Yoshinobu

    2007-02-01

    The usable range of thickness for the solid lithium target in the accelerator-based neutron production for BNCT via the near-threshold (7)Li(p,n)(7)Be reaction was investigated. While the feasibility of using a (7)Li-target with thickness equal to that which is required to slow down a mono-energetic 1.900 MeV incident proton to the 1.881 MeV threshold of the (7)Li(p,n)(7)Be reaction (i.e., t(min) = 2.33 microm) has already been demonstrated, dosimetric properties of neutron fields from targets greater than t(min) were assessed as thicker targets would last longer and offer more stable neutron production. Additionally, the characteristics of neutron fields generated by (7)Li(p,n)(7)Be for Gaussian incident protons with mean energy of 1.900 MeV were evaluated at a (7)Li-target thickness t(min). The main evaluation index applied in this study was the treatable protocol depth (TPD) which corresponds to the depth in an irradiated medium that satisfies the requirements of the adapted dose protocol. A maximum TPD (TPD(max)) was obtained for each irradiation condition from the relationship between the TPD and the thickness of boron dose enhancer (BDE) used. For a mono-energetic 1.900 MeV proton beam, the deepest TPD(max) of 3.88 cm was attained at the (7)Li-target thickness of t(min) and a polyethylene BDE of 1.10 cm. When the intended TPD for a BNCT clinical treatment is shallower than the deepest TPD(max), the usable (7)Li-target thickness would be between t(min) and an upper limit t(upper) whose value depends on the BDE thickness used. In terms of the effect of stability of the incident proton energy, Gaussian incident proton energies stable to within +/-10 keV of 1.900 MeV were found to be feasible for the neutron production via the near-threshold (7)Li(p,n)(7)Be reaction for BNCT provided that a suitable BDE is used.

  19. Measurements and parameterization of neutron energy spectra from targets bombarded with 120 GeV protons

    NASA Astrophysics Data System (ADS)

    Kajimoto, T.; Shigyo, N.; Sanami, T.; Iwamoto, Y.; Hagiwara, M.; Lee, H. S.; Soha, A.; Ramberg, E.; Coleman, R.; Jensen, D.; Leveling, A.; Mokhov, N. V.; Boehnlein, D.; Vaziri, K.; Sakamoto, Y.; Ishibashi, K.; Nakashima, H.

    2014-10-01

    The energy spectra of neutrons were measured by a time-of-flight method for 120 GeV protons on thick graphite, aluminum, copper, and tungsten targets with an NE213 scintillator at the Fermilab Test Beam Facility. Neutron energy spectra were obtained between 25 and 3000 MeV at emission angles of 30°, 45°, 120°, and 150°. The spectra were parameterized as neutron emissions from three moving sources and then compared with theoretical spectra calculated by PHITS and FLUKA codes. The yields of the theoretical spectra were substantially underestimated compared with the yields of measured spectra. The integrated neutron yields from 25 to 3000 MeV calculated with PHITS code were 16-36% of the experimental yields and those calculated with FLUKA code were 26-57% of the experimental yields for all targets and emission angles.

  20. Astrophysical S-factor of the radiative proton capture on 14C at low energies

    NASA Astrophysics Data System (ADS)

    Dubovichenko, Sergey; Burtebaev, Nasurlla; Dzhazairov-Kakhramanov, Albert; Alimov, Dilshod

    2014-07-01

    The phase shift analysis for position location of the 2S1/2 resonance at 1.5 MeV was carried out on the basis of the known experimental measurements of the excitation functions of the p14C elastic scattering at four angles from 90° to 165° and more than 100 energy values in the range from 600-800 keV to 2200-2400 keV. Also, the possibility to describe the available experimental data on the astrophysical S-factor for the proton capture reaction on 14C to the ground state (GS) of 15N at astrophysical energies was considered in the frame of modified potential cluster model (MPCM).

  1. Predictions for net-proton and net-kaon distributions at LHC energies

    NASA Astrophysics Data System (ADS)

    Mehtar-Tani, Yacine; Wolschin, Georg

    2010-05-01

    We investigate baryon and charge transport in relativistic heavy-ion collisions, compare with Au + Au RHIC data at √{sNN} = 0.2 TeV, and make predictions for net-proton rapidity distributions in central Pb + Pb collisions at CERN LHC energies of √{sNN} = 2.8, 3.9, and 5.5 TeV. We use the gluon saturation model and put special emphasis on the midrapidity valley | y | ⩽ 2. Net-kaon distributions are calculated and compared to BRAHMS Au + Au data at RHIC energies of √{sNN} = 0.2 TeV, and predicted for Pb + Pb at 5.5 TeV.

  2. VUV photofragmentation of protonated leucine-enkephalin peptide dimer below ionization energy

    NASA Astrophysics Data System (ADS)

    Milosavljević, Aleksandar R.; Cerovski, Viktor Z.; Ranković, Miloš Lj.; Canon, Francis; Nahon, Laurent; Giuliani, Alexandre

    2014-03-01

    The experimental investigation of 5-8 eV photons induced dissociation of the leucine-enkephalin (Leu-Enk) peptide dimer, performed by coupling a linear ion trap with a synchrotron beamline, in combination with the tandem mass spectrometry, has been reported. The present work extends the existing results on Leu-Enk VUV-induced dissociation to lower sub-ionization photon energy range. The measured tandem mass spectra show that even at the photon energies below the ionization threshold, VUV irradiation of the protonated Leu-Enk dimer precursor can lead to a rich fragmentation pattern, including peptide sequence ions and neutral losses. The photodissociation yields of selected ionic fragments reveal the absorption bands at about 6.7-7.1 eV (185-175 nm). The experimental results have been supported by theoretical description of the [2Leu-Enk + H]+ precursors, optimized at B3LYP/6-31+G( d, p) level of DFT.

  3. Helium and hydrogen generation in pure metals irradiated with high-energy protons and spallation neutrons in LANSCE

    NASA Astrophysics Data System (ADS)

    Oliver, B. M.; James, M. R.; Garner, F. A.; Maloy, S. A.

    2002-12-01

    High-power spallation neutron sources will require accurate estimates of cross-sections for generation of He and H in structural materials. At high-proton energies, very high levels of gas atoms are generated in all constituents of typical iron-based and nickel-based structural alloys, with He typically ˜150 appm/dpa and H at levels ˜3-5 times higher. Improved estimates of these cross-sections have been derived from a series of irradiations conducted at relatively low temperatures (<100 °C) in the Los Alamos Neutron Science Center as part of a test program supporting the Accelerator Production of Tritium Program. Pure metal dosimetry foils were irradiated in two different spectra ranging from ˜800 MeV protons to a mixed distribution of both protons and spallation neutrons. Most of the gas production was due to spallation reactions with the proton beam, although gas and especially damage production from lower-energy spallation neutrons became more significant at the mixed proton/neutron location. The measured He concentrations are similar to those derived in other proton environments, but larger by about a factor of two than those calculated using the LAHET/MCNPX code system. Unlike He, the measured H retention levels are affected by diffusional losses, but H is still retained at rather high concentrations, allowing a lower bound estimate of the H generation cross-sections.

  4. Driving Energy of Reinforcing Steel Bar for Discriminating Background Medium of Concrete

    NASA Astrophysics Data System (ADS)

    Toh, Ryo; Motooka, Seiichi

    2008-05-01

    A method for discriminating the background media of concrete using the quality factor of elastic waves multireflected in the concrete was proposed. A reinforcing steel bar buried inside the concrete is employed as a sound source driven by the induction of impact electromagnetic field radiated from a spiral coil placed on the surface of the concrete. In this paper, the appropriate energy for driving the reinforcing steel bar, to obtain stable quality factors with clear differences between different background media, is studied experimentally. With various driving energies, multireflected elastic waves corresponding to three types of background medium, air, sand, and water, are measured. The quality factors are calculated by the linear predictive coefficient analysis method. The results show that the quality factors tend to increase when the driving energy is at its lower region, and they remain comparatively stable when the driving energy is higher than a certain value. For reinforcing steel bars with different diameters, the curves of quality factors versus driving energies agree well by introducing a newly defined volume-normalized driving energy. For the reinforcing steel bar of 13 mm diameter, the appropriate driving energy for background media discrimination is approximately 0.5 J.

  5. Energy conserved and costs saved by small and medium-size manufacturers, 1988--1989

    SciTech Connect

    Kirsch, F.W.

    1991-05-01

    Energy Analysis and Diagnostic Centers (EADCs) provided energy-conserving and cost saving assistance in 339 small and medium-size manufacturing plants nationwide during 1988-89. This report presents the results of what was recommended to those manufacturers, the record of what was implemented by them, and an analysis of the financial rewards gained by them. It also includes an accounting of the financial returns to the federal government, derived from taxes upon the cost savings, or incremental income, of the manufacturers who implement the EADCs` recommendations. EADCs collect implementation data within a year of the energy audit, and for these results that time period extended through 1990. The EADCs are located at accredited engineering departments of universities and staffed by faculty and students. At present there are 18 EADCs serving manufacturers in 37 states; of these, two were established as a result of the 1989 competition, and five more were chosen competitively in 1990. Most of the results in this report were generated by 11 EADCs (named in the Appendix); two others withdrew voluntarily after completing only 10 energy audits during 1988-89. Primary responsibility for selecting, training, evaluating, and managing the EADCs belongs to the Industrial Technology and Energy Management (ITEM) division of University City Science Center (UCSC). The Department of Energy`s Office of Industrial Technologies sponsors the EADC program through an agreement with UCSC.

  6. Proton motive force, energy recycling by end product excretion, and metabolic uncoupling during anaerobic growth of Pseudomonas mendocina.

    PubMed Central

    Verdoni, N; Aon, M A; Lebeault, J M; Thomas, D

    1990-01-01

    Batch cultures of Pseudomonas mendocina, grown in rich medium with glucose excess, showed metabolic differences dependent upon whether the growth conditions were aerobic or anaerobic, with or without added electron acceptor. Under anaerobic conditions in the absence of nitrate, P. mendocina reached the stationary phase of growth after 2 or 3 days, followed by a stationary phase of 4 to 5 days. Under these conditions, a mixed-type fermentative metabolism (formic, lactic, and acetic acids) appeared. A fivefold-higher specific rate of glucose consumption and eightfold-higher production of organic acids, compared with aerobic cultures, were shown by this microorganism growing anaerobically in the absence of exogenous electron acceptors. The gradients of organic acid produced by P. mendocina under these conditions reached a maximum (lactate, 180 mV; formate, 150 mV; acetate, 215 mV) between days 2 and 3 of culture. The proton motive force (delta p) decreased during growth from -254 to -71 mV. The intracellular pH remained alkaline during the culture, reaching a steady-state value of 7.9. The gradients of organic acids apparently contributed to the generation of a delta p, which, according to the Energy Recycling Model (P. A. M. Michels, J. P. J. Michels, J. Boonstra, and W. N. Konings, FEMS Microbiol. Lett. 5:357-364, 1979), would produce an average energy gain of 1 or 1.5 mol of ATP equivalents per mol of glucose consumed with H+/ATP stoichiometry of 3 or 2, respectively. Low YATP and Yglucose values were observed, suggesting that an uncoupled metabolism exists; i.e., ATP produced by catabolic processes is not directly used for biomass synthesis. This metabolic uncoupling could be induced at least in part by organic acids and the ATP wastage could be induced by a membrane-bound ATPase involved in intracellular pH regulation. PMID:2254245

  7. Computer simulation program for medium-energy ion scattering and Rutherford backscattering spectrometry

    NASA Astrophysics Data System (ADS)

    Nishimura, Tomoaki

    2016-03-01

    A computer simulation program for ion scattering and its graphical user interface (MEISwin) has been developed. Using this program, researchers have analyzed medium-energy ion scattering and Rutherford backscattering spectrometry at Ritsumeikan University since 1998, and at Rutgers University since 2007. The main features of the program are as follows: (1) stopping power can be chosen from five datasets spanning several decades (from 1977 to 2011), (2) straggling can be chosen from two datasets, (3) spectral shape can be selected as Gaussian or exponentially modified Gaussian, (4) scattering cross sections can be selected as Coulomb or screened, (5) simulations adopt the resonant elastic scattering cross section of 16O(4He, 4He)16O, (6) pileup simulation for RBS spectra is supported, (7) natural and specific isotope abundances are supported, and (8) the charge fraction can be chosen from three patterns (fixed, energy-dependent, and ion fraction with charge-exchange parameters for medium-energy ion scattering). This study demonstrates and discusses the simulations and their results.

  8. Nuclear physics with a medium-energy Electron-Ion Collider

    SciTech Connect

    A. Accardi, V. Guzey, A. Prokudin, C. Weiss

    2012-06-01

    A polarized ep/eA collider (Electron-Ion Collider, or EIC) with variable center-of-mass energy {radical}s {approx} 20-70 GeV and a luminosity {approx}10{sup 34} cm{sup -2} s{sup -1} would be uniquely suited to address several outstanding questions of Quantum Chromodynamics (QCD) and the microscopic structure of hadrons and nuclei: (i) the three-dimensional structure of the nucleon in QCD (sea quark and gluon spatial distributions, orbital motion, polarization, correlations); (ii) the fundamental color fields in nuclei (nuclear parton densities, shadowing, coherence effects, color transparency); (iii) the conversion of color charge to hadrons (fragmentation, parton propagation through matter, in-medium jets). We briefly review the conceptual aspects of these questions and the measurements that would address them, emphasizing the qualitatively new information that could be obtained with the collider. Such a medium-energy EIC could be realized at Jefferson Lab after the 12 GeV Upgrade (MEIC), or at Brookhaven National Lab as the low-energy stage of eRHIC.

  9. EGRET High Energy Capability and Multiwavelength Flare Studies and Solar Flare Proton Spectra

    NASA Technical Reports Server (NTRS)

    Chupp, Edward L.

    1997-01-01

    UNH was assigned the responsibility to use their accelerator neutron measurements to verify the TASC response function and to modify the TASC fitting program to include a high energy neutron contribution. Direct accelerator-based measurements by UNH of the energy-dependent efficiencies for detecting neutrons with energies from 36 to 720 MeV in NaI were compared with Monte Carlo TASC calculations. The calculated TASC efficiencies are somewhat lower (by about 20%) than the accelerator results in the energy range 70-300 MeV. The measured energy-loss spectrum for 207 MeV neutron interactions in NaI were compared with the Monte Carlo response for 200 MeV neutrons in the TASC indicating good agreement. Based on this agreement, the simulation was considered to be sufficiently accurate to generate a neutron response library to be used by UNH in modifying the TASC fitting program to include a neutron component in the flare spectrum modeling. TASC energy-loss data on the 1991 June 11 flare was transferred to UNH. Also included appendix: Gamma-rays and neutrons as a probe of flare proton spectra: the solar flare of 11 June 1991.

  10. The Energy Spectra of Proton and Helium Measured from the ATIC Experiment

    NASA Technical Reports Server (NTRS)

    Ahn, H. S.; Seo, E. S.; Adams, J. H.; Bashindzhagyan, G. L.; Batkov, K. E.; Chang, J.; Christl, M.; Fazely, A. R.; Ganel, O.; Gunasingha, R. M.

    2004-01-01

    The Advanced Thin Ionization Calorimeter (ATIC) balloon experiment is designed to investigate the composition and energy spectra of cosmic rays at the highest energies currently accessible from direct measurements, the region up to 100 TeV. The instrument consists of a silicon matrix for charge measurement, a graphite target (0.75 nuclear interaction length) to induce hadronic fragmentation, 3 scintillator strip hodoscopes for triggering and helping reconstruct trajectory, and a BGO calorimeter (18 radiation lengths) to measure the energy of incident particles. ATIC had two successful Long Duration Balloon (LDB) flights from McMurdo, Antarctica: from 12/28/00 to 01/13/01 and from 12/29/02 to 01/18/03. We present the energy spectra of proton and helium extracted from the ATIC flights, over the energy range from 100 GeV to 100 TeV, and compare them with the results from other experiments at both the lower and higher energy ends.

  11. High order magnetic optics for high dynamic range proton radiography at a kinetic energy 800 MeV

    DOE PAGES

    Sjue, Sky K. L.; Morris, Christopher L.; Merrill, Frank Edward; Mariam, Fesseha Gebre; Saunders, Alexander

    2016-01-14

    Flash radiography with 800 MeV kinetic energy protons at Los Alamos National Laboratory is an important experimental tool for investigations of dynamic material behavior driven by high explosives or pulsed power. The extraction of quantitative information about density fields in a dynamic experiment from proton generated images requires a high fidelity model of the protonimaging process. It is shown that accurate calculations of the transmission through the magnetic lens system require terms beyond second order for protons far from the tune energy. The approach used integrates the correlated multiple Coulomb scattering distribution simultaneously over the collimator and the image plane.more » Furthermore, comparison with a series of static calibrationimages demonstrates the model’s accurate reproduction of both the transmission and blur over a wide range of tune energies in an inverse identity lens that consists of four quadrupole electromagnets.« less

  12. Storm- Time Dynamics of Ring Current Protons: Implications for the Long-Term Energy Budget in the Inner Magnetosphere.

    NASA Astrophysics Data System (ADS)

    Gkioulidou, M.; Ukhorskiy, A. Y.; Mitchell, D. G.; Lanzerotti, L. J.

    2015-12-01

    The ring current energy budget plays a key role in the global electrodynamics of Earth's space environment. Pressure gradients developed in the inner magnetosphere can shield the near-Earth region from solar wind-induced electric fields. The distortion of Earth's magnetic field due to the ring current affects the dynamics of particles contributing both to the ring current and radiation belts. Therefore, understanding the long-term evolution of the inner magnetosphere energy content is essential. We have investigated the evolution of ring current proton pressure (7 - 600 keV) in the inner magnetosphere based on data from the Radiation Belt Storm Probes Ion Composition Experiment (RBSPICE) instrument aboard Van Allen Probe B throughout the year 2013. We find that although the low-energy component of the protons (< 80 keV) is governed by convective timescales and is very well correlated with the Dst index, the high-energy component (>100 keV) varies on much longer timescales and shows either no or anti-correlation with the Dst index. Interestingly, the contributions of the high- and low-energy protons to the total energy content are comparable. Our results indicate that the proton dynamics, and as a consequence the total energy budget in the inner magnetosphere (inside geosynchronous orbit), is not strictly controlled by storm-time timescales as those are defined by the Dst index.

  13. LiF TLD-100 as a Dosimeter in High Energy Proton Beam Therapy-Can It Yield Accurate Results?

    SciTech Connect

    Zullo, John R. Kudchadker, Rajat J.; Zhu, X. Ronald; Sahoo, Narayan; Gillin, Michael T.

    2010-04-01

    In the region of high-dose gradients at the end of the proton range, the stopping power ratio of the protons undergoes significant changes, allowing for a broad spectrum of proton energies to be deposited within a relatively small volume. Because of the potential linear energy transfer dependence of LiF TLD-100 (thermolumescent dosimeter), dose measurements made in the distal fall-off region of a proton beam may be less accurate than those made in regions of low-dose gradients. The purpose of this study is to determine the accuracy and precision of dose measured using TLD-100 for a pristine Bragg peak, particularly in the distal fall-off region. All measurements were made along the central axis of an unmodulated 200-MeV proton beam from a Probeat passive beam-scattering proton accelerator (Hitachi, Ltd., Tokyo, Japan) at varying depths along the Bragg peak. Measurements were made using TLD-100 powder flat packs, placed in a virtual water slab phantom. The measurements were repeated using a parallel plate ionization chamber. The dose measurements using TLD-100 in a proton beam were accurate to within {+-}5.0% of the expected dose, previously seen in our past photon and electron measurements. The ionization chamber and the TLD relative dose measurements agreed well with each other. Absolute dose measurements using TLD agreed with ionization chamber measurements to within {+-} 3.0 cGy, for an exposure of 100 cGy. In our study, the differences in the dose measured by the ionization chamber and those measured by TLD-100 were minimal, indicating that the accuracy and precision of measurements made in the distal fall-off region of a pristine Bragg peak is within the expected range. Thus, the rapid change in stopping power ratios at the end of the range should not affect such measurements, and TLD-100 may be used with confidence as an in vivo dosimeter for proton beam therapy.

  14. Changes in the Zero-Point Energy of the Protons as the Source of the Binding Energy of Water to A-Phase DNA

    SciTech Connect

    Reiter, G. F.; Senesi, R.; Mayers, J.

    2010-10-01

    The measured changes in the zero-point kinetic energy of the protons are entirely responsible for the binding energy of water molecules to A phase DNA at the concentration of 6 water molecules/base pair. The changes in kinetic energy can be expected to be a significant contribution to the energy balance in intracellular biological processes and the properties of nano-confined water. The shape of the momentum distribution in the dehydrated A phase is consistent with coherent delocalization of some of the protons in a double well potential, with a separation of the wells of 0.2 Angst .

  15. Corrections to the eikonal approximation for nuclear scattering at medium energies

    NASA Astrophysics Data System (ADS)

    Buuck, Micah; Miller, Gerald A.

    2014-08-01

    The upcoming Facility for Rare Isotope Beams (FRIB) at the National Superconducting Cyclotron Laboratory (NSCL) at Michigan State University has reemphasized the importance of accurate modeling of low energy nucleus-nucleus scattering. Such calculations have been simplified by using the eikonal approximation. As a high energy approximation, however, its accuracy suffers for the medium energy beams that are of current experimental interest. A prescription developed by Wallace [Phys. Rev. Lett. 27, 622 (1971), 10.1103/PhysRevLett.27.622 and Ann. Phys. (NY) 78, 190 (1973), 10.1016/0003-4916(73)90008-0] that obtains the scattering propagator as an expansion around the eikonal propagator (Glauber approach) has the potential to extend the range of validity of the approximation to lower energies. Here we examine the properties of this expansion, and calculate the first-, second-, and third-order corrections for the scattering of a spinless particle off of a Ca40 nucleus, and for nuclear breakup reactions involving Be11. We find that, including these corrections extends the lower bound of the range of validity down to energies as low as about 45 MeV. At that energy the corrections provide as much as a 15% correction to certain processes.

  16. Proton radiography to improve proton therapy treatment

    NASA Astrophysics Data System (ADS)

    Takatsu, J.; van der Graaf, E. R.; Van Goethem, M.-J.; van Beuzekom, M.; Klaver, T.; Visser, J.; Brandenburg, S.; Biegun, A. K.

    2016-01-01

    The quality of cancer treatment with protons critically depends on an accurate prediction of the proton stopping powers for the tissues traversed by the protons. Today, treatment planning in proton radiotherapy is based on stopping power calculations from densities of X-ray Computed Tomography (CT) images. This causes systematic uncertainties in the calculated proton range in a patient of typically 3-4%, but can become even 10% in bone regions [1,2,3,4,5,6,7,8]. This may lead to no dose in parts of the tumor and too high dose in healthy tissues [1]. A direct measurement of proton stopping powers with high-energy protons will allow reducing these uncertainties and will improve the quality of the treatment. Several studies have shown that a sufficiently accurate radiograph can be obtained by tracking individual protons traversing a phantom (patient) [4,6,10]. Our studies benefit from the gas-filled time projection chambers based on GridPix technology [2], developed at Nikhef, capable of tracking a single proton. A BaF2 crystal measuring the residual energy of protons was used. Proton radiographs of phantom consisting of different tissue-like materials were measured with a 30×30 mm2 150 MeV proton beam. Measurements were simulated with the Geant4 toolkit.First experimental and simulated energy radiographs are in very good agreement [3]. In this paper we focus on simulation studies of the proton scattering angle as it affects the position resolution of the proton energy loss radiograph. By selecting protons with a small scattering angle, the image quality can be improved significantly.

  17. Radiative neutron capture on a proton at big-bang nucleosynthesis energies

    SciTech Connect

    Ando, S.; Cyburt, R. H.; Hong, S. W.; Hyun, C. H.

    2006-08-15

    The total cross section for radiative neutron capture on a proton, np{yields}d{gamma}, is evaluated at big-bang nucleosynthesis (BBN) energies. The electromagnetic transition amplitudes are calculated up to next-to-leading-order within the framework of pionless effective field theory with dibaryon fields. We also calculate the d{gamma}{yields}np cross section and the photon analyzing power for the d{gamma}(vector sign){yields}np process from the amplitudes. The values of low-energy constants that appear in the amplitudes are estimated by a Markov Chain Monte Carlo analysis using the relevant low-energy experimental data. Our result agrees well with those of other theoretical calculations except for the np{yields}d{gamma} cross section at some energies estimated by an R-matrix analysis. We also study the uncertainties in our estimation of the np{yields}d{gamma} cross section at relevant BBN energies and find that the estimated cross section is reliable to within {approx}1% error.

  18. Energy related germination and survival rates of water-imbibed Arabidopsis seeds irradiated with protons

    NASA Astrophysics Data System (ADS)

    Qin, H. L.; Xue, J. M.; Lai, J. N.; Wang, J. Y.; Zhang, W. M.; Miao, Q.; Yan, S.; Zhao, W. J.; He, F.; Gu, H. Y.; Wang, Y. G.

    2006-04-01

    In order to investigate the influence of ion energy on the germination and survival rates, water-imbibed Arabidopsis seeds were irradiated with protons in atmosphere. The ion fluence used in this experiment was in the range of 4 × 109-1 × 1014 ions/cm2. The ion energy is from 1.1 MeV to 6.5 MeV. According to the structure of the seed and TRIM simulation, the ions with the energy of 6.5 MeV can irradiate the shoot apical meristem directly whereas the ions with the energy of 1.1 MeV cannot. The results showed that both the germination and survival rates decrease while increasing the ion fluence, and the fluence-respond curve for each energy has different character. Besides the shoot apical meristem (SAM), which is generally considered as the main radiobiological target, the existence of a secondary target around SAM is proposed in this paper.

  19. Comparing Solar-Flare Acceleration of >-20 MeV Protons and Electrons Above Various Energies

    NASA Technical Reports Server (NTRS)

    Shih, Albert Y.

    2010-01-01

    A large fraction (up to tens of percent) of the energy released in solar flares goes into accelerated ions and electrons, and studies indicate that these two populations have comparable energy content. RHESSI observations have shown a striking close linear correlation between the 2.223 MeV neutron-capture gamma-ray line and electron bremsstrahlung emission >300 keV, indicating that the flare acceleration of >^20 MeV protons and >300 keV electrons is roughly proportional over >3 orders of magnitude in fluence. We show that the correlations of neutron-capture line fluence with GOES class or with bremsstrahlung emission at lower energies show deviations from proportionality, primarily for flares with lower fluences. From analyzing thirteen flares, we demonstrate that there appear to be two classes of flares with high-energy acceleration: flares that exhibit only proportional acceleration of ions and electrons down to 50 keV and flares that have an additional soft, low-energy bremsstrahlung component, suggesting two separate populations of accelerated electrons. We use RHESSI spectroscopy and imaging to investigate a number of these flares in detail.

  20. Production of ACTINIUM-225 via High Energy Proton Induced Spallation of THORIUM-232

    NASA Astrophysics Data System (ADS)

    Harvey, James; Nolen, Jerry A.; Kroc, Thomas; Gomes, Itacil; Horwitz, E. Philip.; McAlister, Daniel R.

    2010-06-01

    The science of cancer research is currently expanding its use of alpha particle emitting radioisotopes. Coupled with the discovery and proliferation of molecular species that seek out and attach to tumors, new therapy and diagnostics are being developed to enhance the treatment of cancer and other diseases. This latest technology is commonly referred to as Alpha Immunotherapy (AIT). Actinium-225/Bismuth-213 is a parent/daughter alpha-emitting radioisotope pair that is highly sought after because of the potential for treating numerous diseases and its ability to be chemically compatible with many known and widely used carrier molecules (such as monoclonal antibodies and proteins/peptides). The object of this effort is to refine the simulations for producing actinium-225 at proton beam energies of 400 MeV and above up to about 8 GeV. Once completed, the simulations will be experimentally verified using 400 MeV and 8 GeV protons available at Fermi National Accelerator Laboratory. Targets will be processed at Argonne National Laboratory to separate and purify the actinium-225 that will subsequently be transferred to NorthStar laboratory facilities for product quality testing and comparison to the product quality of ORNL produced actinium-225, which is currently the industry standard. The test irradiations at FNAL will produce 1-20 mCi per day which is more than sufficient for quantitative evaluation of the proposed production process.

  1. Energy dependence of pion in-medium effects on the π-/π+ ratio in heavy-ion collisions

    NASA Astrophysics Data System (ADS)

    Xu, Jun; Chen, Lie-Wen; Ko, Che Ming; Li, Bao-An; Ma, Yu-Gang

    2013-06-01

    Within the framework of a thermal model with its parameters fitted to the results from an isospin-dependent Boltzmann-Uehling-Uhlenbeck transport model, we have studied the pion in-medium effect on the charged-pion ratio in heavy-ion collisions at various energies. We find that due to the cancellation between the effects from pion-nucleon s-wave and p-wave interactions in nuclear medium, the π-/π+ ratio generally decreases after including the pion in-medium effect. The effect is larger at lower collision energies as a result of narrower pion spectral functions at lower temperatures.

  2. Sensitivity Analysis on the Performance of Medium Deep Borehole Thermal Energy Storage Systems

    NASA Astrophysics Data System (ADS)

    Welsch, Bastian; Rühaak, Wolfram; Schulte, Daniel O.; Bär, Kristian; Sass, Ingo

    2016-04-01

    Seasonal thermal energy storages using arrays of medium deep (400 m - 1500 m) borehole heat exchangers (BHE) have two main advantages over near surface (< 400 m) BHE storages. Medium deep borehole thermal energy storages (MD-BTES) have a lower thermal impact on shallow groundwater resources and require less surface area. However, the storage performance indicators like the efficiency, the storage capacity and the supplied fluid temperature of MD-BTES are unknown as such system has not been put into practice so far. To study the influence of various design and operation parameters on the storage performance, more than 240 numerical models of different MD-BTES systems were compared in a sensitivity analysis. Most importantly, the BHE length, the number of BHEs, the spacing between the BHEs, the inlet temperatures of the heat transfer fluid into the BHEs and the underground properties were varied. A simplified underground model was used and also a simplified operation procedure was applied for a period of 30 years of storage operation. The results show a strong dependency of the storage performance on the studied design and operation parameters as well as on the underground properties. In the best case, storage efficiency reaches over 80 % in the 30th year of operation, whereas poorly designed storage systems show efficiencies of less than 20 %.

  3. A program in medium-energy nuclear physics. Progress report, January 1, 1992--March 31, 1995

    SciTech Connect

    Berman, B.L.; Dhuga, K.S.

    1994-08-01

    This renewal proposal requests continued funding for our program in experimental medium-energy nuclear physics. The focus of our program remains the understanding of the short-range part of the strong interaction in the nuclear medium. In the past three years we have focused our attention ever more sharply on experiments with real tagged photons at CEBAF. We are part of the Hall-B Collaboration at CEBAF. We are co-spokespersons on two approved CEBAF experiments, Photoreactions on {sup 3}He and Photoabsorption and Photofission of Nuclei, and we are preparing another, Nondiffractive Photoproduction of the {rho} Meson with Linearly Polarized Photons, for presentation to the next CEBAF PAC. We are part of the team that is instrumenting the Photon Tagger and a high-energy tagged polarized-photon beam for Hall B; some of the instrumentation for these projects is being built at our Nuclear Detector Laboratory, under the auspices of The George Washington University Center for Nuclear Studies. Our recent measurements of pion scattering from {sup 3}H and {sup 3}He at LAMPF and of cluster knockout from few-body nuclei at NIKHEF have yielded very provocative results, showing the importance of the very light nuclei as a laboratory for quantifying important aspects of the nuclear many-body force. We look forward to expanding our studies of short-range forces in nuclei, particularly the very fight nuclei using electromagnetic probes and employing the extraordinary power of CEBAF and the CLAS.

  4. P-986 Letter of Intent: Medium-Energy Antiproton Physics at Fermilab

    SciTech Connect

    Asner, David M.; Phillips, Thomas J.; Apollinari, Giorgio; Broemmelsiek, Daniel R.; Brown, Charles N.; Christian, David C.; Derwent, Paul; Gollwitzer, Keith; Hahn, Alan; Papadimitriou, Vaia; Stefanski, Ray; /Fermilab /INFN, Ferrara /Hbar Technol., West Chicago /IIT, Chicago /CHEP, Taegu /Luther Coll. /Michigan U. /Northwestern U. /Notre Dame U. /St. Xavier U., Chicago

    2009-02-05

    Fermilab has long had the world's most intense antiproton source. Despite this, the opportunities for medium-energy antiproton physics at Fermilab have been limited in the past and - with the antiproton source now exclusively dedicated to serving the needs of the Tevatron Collider - are currently nonexistent. The anticipated shutdown of the Tevatron in 2010 presents the opportunity for a world-leading medium-energy antiproton program. We summarize the current status of the Fermilab antiproton facility and review some physics topics for which the experiment we propose could make the world's best measurements. Among these, the ones with the clearest potential for high impact and visibility are in the area of charm mixing and CP violation. Continued running of the Antiproton Source following the shutdown of the Tevatron is thus one of the simplest ways that Fermilab can restore a degree of breadth to its future research program. The impact on the rest of the program will be minor. We request a small amount of effort over the coming months in order to assess these issues in more detail.

  5. New measurement of the 3He(α,γ)7Be cross section at medium energies

    NASA Astrophysics Data System (ADS)

    Carmona-Gallardo, M.; Nara Singh, B. S.; Borge, M. J. G.; Briz, J. A.; Cubero, M.; Fulton, B. R.; Fynbo, H.; Gordillo, N.; Hass, M.; Haquin, G.; Maira, A.; Nácher, E.; Nir-El, Y.; Kumar, V.; McGrath, J.; Muñoz-Martín, A.; Perea, A.; Pesudo, V.; Ribeiro, G.; Sánchez del Rio, J.; Tengblad, O.; Yaniv, R.; Yungreis, Z.

    2012-09-01

    We report on a new cross-section measurement for the 3He(α, γ)7Be reaction at three medium energies of Ec.m. between 1 and 3 MeV. The interest stems from the significant role played by the reaction in calculating an accurate solar neutrino flux and the primordial 7Li abundance. The energy dependence of the astrophysical S34 factor observed in the present work, especially above 1 MeV, highlights the need to constrain theories in order to obtain a precise extrapolated value for S34(0). In this context, a comparison with the recent theoretical work in a fully microscopic fermionic molecular dynamics approach and a few other representative calculations emphasize the need for further experimental as well as theoretical work to resolve the existing conflicts.

  6. Charge-equilibrium and radiation of low-energy cosmic rays passing through interstellar medium

    NASA Technical Reports Server (NTRS)

    Rule, D. W.; Omidvar, K.

    1977-01-01

    The charge equilibrium and radiation of an oxygen and an iron beam in the MeV per nucleon energy range, representing a typical beam of low-energy cosmic rays passing through the interstellar medium, is considered. Electron loss of the beam has been taken into account by means of the First Born approximation allowing for the target atom to remain unexcited, or to be excited to all possible states. Electron capture cross sections have been calculated by means of the scaled Oppenheimer-Brinkman-Kramers approximation, taking into account all atomic shells of the target atoms. Radiation of the beam due to electron capture into the excited states of the ion, collisional excitation and collisional inner-shell ionization of the ions has been considered. Effective X-ray production cross sections and multiplicities for the most energetic X-ray lines emitted by the Fe and O beams have been calculated.

  7. General purpose computational tools for simulation and analysis of medium-energy backscattering spectra

    NASA Astrophysics Data System (ADS)

    Weller, Robert A.

    1999-06-01

    This paper describes a suite of computational tools for general-purpose ion-solid calculations, which has been implemented in the platform-independent computational environment Mathematica®. Although originally developed for medium energy work (beam energies < 300 keV), they are suitable for general, classical, non-relativistic calculations. Routines are available for stopping power, Rutherford and Lenz-Jensen (screened) cross sections, sputtering yields, small-angle multiple scattering, and back-scattering-spectrum simulation and analysis. Also included are a full range of supporting functions, as well as easily accessible atomic mass and other data on all the stable isotopes in the periodic table. The functions use common calling protocols, recognize elements and isotopes by symbolic names and, wherever possible, return symbolic results for symbolic inputs, thereby facilitating further computation. A new paradigm for the representation of backscattering spectra is introduced.

  8. The Advanced Energetic Pair Telescope (AdEPT), a Medium-Energy Gamma-Ray Polarimeter

    NASA Astrophysics Data System (ADS)

    Hunter, Stanley D.

    2015-01-01

    Since the launch of AGILE and FERMI, the scientific progress in high-energy (Eg > 200 MeV) gamma-ray science has been, and will continue to be dramatic. Both of these telescopes cover a broad energy range from ~20 MeV to >10 GeV. However, neither instrument is optimized for observations below ~200 MeV where many astrophysical objects exhibit unique, transitory behavior, such as spectral breaks, bursts, and flares. Hence, while significant progress from current observations is expected, a significant sensitivity gap will remain in the medium-energy regime (0.75 - 200 MeV) that has been explored only by COMPTEL and EGRET on CGRO. Exploring this regime with angular resolution near the kinematic limit and high polarization sensitivity requires a gamma-ray telescope design with a low density electron track imaging detector.The medium-energy (~5 to ~200 MeV) Advanced Energetic Pair Telescope (AdEPT), will achieve angular resolution of ~0.6° at 70 MeV, similar to the angular resolution of Fermi/LAT at ~1 GeV that brought tremendous success in identifying new sources. AdEPT will also provide unprecedented polarization sensitivity of ~1% for a 1 Crab source. The enabling technology for AdEPT is the Three-Dimensional Track Imager (3-DTI) a low-density, large volume, gas time-projection chamber with a 2-dimensional readout. The 3-DTI provides high-resolution three-dimensional electron tracking with minimal Coulomb scattering that is essential to achieve high angular resolution and polarization sensitivity. We describe our ROSES/APRA funded program to build a 50´50´100 cm3 AdEPT prototype, measure the angular resolution and polarization sensitivity of this prototype at an accelerator, and highlight some of the key science questions that AdEPT will address.

  9. Computational study of transport and energy deposition of intense laser-accelerated proton beams in solid density matter

    NASA Astrophysics Data System (ADS)

    Kim, J.; McGuffey, C.; Qiao, B.; Beg, F. N.; Wei, M. S.; Grabowski, P. E.

    2015-11-01

    With intense proton beams accelerated by high power short pulse lasers, solid targets are isochorically heated to become partially-ionized warm or hot dense matter. In this regime, the thermodynamic state of the matter significantly changes, varying the proton stopping power where both bound and free electrons contribute. Additionally, collective beam-matter interaction becomes important to the beam transport. We present self-consistent hybrid particle-in-cell (PIC) simulation results of proton beam transport and energy deposition in solid-density matter, where the individual proton stopping and the collective effects are taken into account simultaneously with updates of stopping power in the varying target conditions and kinetic motions of the beam in the driven fields. Broadening of propagation range and self-focusing of the beam led to unexpected target heating by the intense proton beams, with dependence on the beam profiles and target conditions. The behavior is specifically studied for the case of an experimentally measured proton beam from the 1.25 kJ, 10 ps OMEGA EP laser transporting through metal foils. This work was supported by the U.S. DOE under Contracts No. DE-NA0002034 and No. DE-AC52-07NA27344 and by the U.S. AFOSR under Contract FA9550-14-1-0346.

  10. A medium-energy photoemission and ab-initio investigation of cubic yttria-stabilised zirconia

    SciTech Connect

    Cousland, G. P.; Cui, X. Y.; Smith, A. E.; Stampfl, C. M.; Wong, L.; Tayebjee, M.; Yu, D.; Triani, G.; Evans, P. J.; Ruppender, H.-J.; Jang, L.-Y.; Stampfl, A. P. J.

    2014-04-14

    Experimental and theoretical investigations into the electronic properties and structure of cubic yttria-stabilized zirconia are presented. Medium-energy x-ray photoemission spectroscopy measurements have been carried out for material with a concentration of 8-9 mol. % yttria. Resonant photoemission spectra are obtained for a range of photon energies that traverse the L2 absorption edge for both zirconium and yttrium. Through correlation with results from density-functional theory (DFT) calculations, based on structural models proposed in the literature, we assign photoemission peaks appearing in the spectra to core lines and Auger transitions. An analysis of the core level features enables the identification of shifts in the core level energies due to different local chemical environments of the constituent atoms. In general, each core line feature can be decomposed into three contributions, with associated energy shifts. Their identification with results of DFT calculations carried out for proposed atomic structures, lends support to these structural models. The experimental results indicate a multi-atom resonant photoemission effect between nearest-neighbour oxygen and yttrium atoms. Near-edge x-ray absorption fine structure spectra for zirconium and yttrium are also presented, which correlate well with calculated Zr- and Y-4d electron partial density-of-states and with Auger electron peak area versus photon energy curve.

  11. TPD-based evaluation of near threshold mono-energetic proton energies for the (7)Li(p,n)(7)Be production of neutrons for BNCT.

    PubMed

    Bengua, Gerard; Kobayashi, Tooru; Tanaka, Kenichi; Nakagawa, Yoshinobu; Unesaki, Hironobu

    2006-08-21

    An evaluation of mono-energetic proton energies ranging from 1.885 MeV to 1.920 MeV was carried out to determine the viability of these near threshold energies in producing neutrons for BNCT via the (7)Li(p,n)(7)Be reaction. Neutron fields generated at these proton energies were assessed using the treatable protocol depth (TPD) and the maximum TPD (TPD(max)) as evaluation indices. The heavy charged particle (HCP) dose rate to tumour was likewise applied as a figure of merit in order to account for irradiation time and required proton current. Incident proton energies closer to the reaction threshold generated deeper TPDs compared to higher energy protons when no boron dose enhancers (BDE) were placed in the irradiation field. Introducing a BDE resulted in improved TPDs for high proton energies but their achievable TPD(max) were comparatively lower than that obtained for lower proton energies. In terms of the HCP dose rate to tumour, higher proton energies generated neutron fields that yielded higher dose rates both at TPD(max) and at fixed depths of comparison. This infers that higher currents are required to deliver the prescribed treatment dose to tumours for proton beams with energies closer to the (7)Li(p,n)(7)Be reaction threshold and more achievable proton currents of around 10 mA or less for proton energies from 1.900 MeV and above. The dependence on incident proton energy of the TPD, TPD(max) and the HCP dose rate to tumour with respect to the (10)B concentration in tumour and healthy tissues were also clarified in this study. Increasing the (10)B concentration in tumour while maintaining a constant T/N ratio resulted in deeper TPD(max) where a greater change in TPD(max) was obtained for proton energies closer to the (7)Li(p,n)(7)Be reaction threshold. The HCP dose rates to tumour for all proton energies also went up, with the higher proton energies benefiting more from the increased (10)B concentration.

  12. Temporal relationship between high-energy proton acceleration and magnetic field changes during solar flares

    NASA Astrophysics Data System (ADS)

    Kurt, Victoria; Yushkov, Boris

    Understanding of the association of the magnetic field evolution in the corona and the temporal evolution of electromagnetic emissions produced by the accelerated particles during a solar flare can provide information about the nature of the energy-release process and its location. Recent high-spatial-resolution observations in HXR, UV and radio emissions allow one to study in detail a structure of two-ribbon flare site. According to these observations, the flare process can be divided into two different intervals with different temporal evolution of morphological structure: loop contraction during impulsive phase and subsequent loop expansion. Оn the other hand, the appearance of high-energy protons (with energy >300 MeV - an energy threshold of the pion production) in the solar atmosphere can be revealed from an emerging pion-decay component of high-energy gamma-ray emission. The present work is based on comparison of measurements of high-energy gamma-rays performed with the SONG detector onboard the CORONAS-F mission and reported observations of magnetic field evolution, such as HXR foot points (FP) separation and flare shear temporal behavior, or motion of UV/radio loops. We reliably identified the pion-decay component of gamma-ray emission in the course of five events attended with suitable spatial observations, namely, 2001 August 25, 2002 August 24, 2003 October 28, 2003 October 29, and 2005 January 20, and determined its onset time. We found that in these events the pion-decay emission occurred when the distance between conjugated foot-points of flare loops ceased to decrease and began to increase, i.e. changed from shrinkage to expansion. This result leads to the conclusion that the most efficient proton acceleration up to >300 MeV coincided in time with the radical reconfiguration of the magnetic field in the flare site. Earlier we found that the pion-decay emission onset in the 2003 October 28 flare was close to the time of maximum change rate of the

  13. A comparison of energy-resolved vibrational activation/dissociation characteristics of protonated and sodiated high mannose N-glycopeptides.

    PubMed

    Aboufazeli, Forouzan; Kolli, Venkata; Dodds, Eric D

    2015-04-01

    Fragmentation of glycopeptides in tandem mass spectrometry (MS/MS) plays a pivotal role in site-specific protein glycosylation profiling by allowing specific oligosaccharide compositions and connectivities to be associated with specific loci on the corresponding protein. Although MS/MS analysis of glycopeptides has been successfully performed using a number of distinct ion dissociation methods, relatively little is known regarding the fragmentation characteristics of glycopeptide ions with various charge carriers. In this study, energy-resolved vibrational activation/dissociation was examined via collision-induced dissociation for a group of related high mannose tryptic glycopeptides as their doubly protonated, doubly sodiated, and hybrid protonated sodium adduct ions. The doubly protonated glycopeptide ions with various compositions were found to undergo fragmentation over a relatively low but wide range of collision energies compared with the doubly sodiated and hybrid charged ions, and were found to yield both glycan and peptide fragmentation depending on the applied collision energy. By contrast, the various doubly sodiated glycopeptides were found to dissociate over a significantly higher but narrow range of collision energies, and exhibited only glycan cleavages. Interestingly, the hybrid protonated sodium adduct ions were consistently the most stable of the precursor ions studied, and provided fragmentation information spanning both the glycan and the peptide moieties. Taken together, these findings illustrate the influence of charge carrier over the energy-resolved vibrational activation/dissociation characteristics of glycopeptides, and serve to suggest potential strategies that exploit the analytically useful features uniquely afforded by specific charge carriers or combinations thereof.

  14. Performance of Ga(0.47)In(0.53)As cells over a range of proton energies

    NASA Technical Reports Server (NTRS)

    Weinberg, I.; Jain, R. K.; Vargasaburto, C.; Wilt, D. M.; Scheiman, D. A.

    1995-01-01

    Ga(0.47)In(0.53)As solar cells were processed by OMVPE and their characteristics determined at proton energies of 0.2, 0.5, and 3 MeV. Emphasis was on characteristics applicable to use of this cell as the low bandgap member of a monolithic, two terminal high efficiency InP/GaInAs cell. It was found that the radiation induced degradation in efficiency, I(sub SC), V(sub OC) and diffusion length increased with decreasing proton energy. When efficiency degradations were compared with InP it was observed that the present cells showed considerably more degradation over the entire energy range. Similar to InP, R(sub C), the carrier removal rate, decreased with increasing proton energy. However, numerical values for R(sub C) differed from those observed with InP. The difference is attributed to differing defect behavior between the two cell types. It was concluded that particular attention should be paid to the effects of low energy protons especially when the particle's track ends in one cell of the multibandgap device.

  15. PIC Simulations in Low Energy Part of PIP-II Proton Linac

    SciTech Connect

    Romanov, Gennady

    2014-07-01

    The front end of PIP-II linac is composed of a 30 keV ion source, low energy beam transport line (LEBT), 2.1 MeV radio frequency quadrupole (RFQ), and medium energy beam transport line (MEBT). This configuration is currently being assembled at Fermilab to support a complete systems test. The front end represents the primary technical risk with PIP-II, and so this step will validate the concept and demonstrate that the hardware can meet the specified requirements. SC accelerating cavities right after MEBT require high quality and well defined beam after RFQ to avoid excessive particle losses. In this paper we will present recent progress of beam dynamic study, using CST PIC simulation code, to investigate partial neutralization effect in LEBT, halo and tail formation in RFQ, total emittance growth and beam losses along low energy part of the linac.

  16. SU-E-T-533: LET Dependence Correction of Radiochromic Films for Application in Low Energy Proton Irradiation

    SciTech Connect

    Reinhardt, S; Wuerl, M; Assmann, W; Parodi, K; Greubel, C; Wilkens, J; Hillbrand, M; Mairani, A

    2015-06-15

    Purpose: Many cell irradiation experiments with low-energy laser-driven ions rely on radiochromic films (RCF), because of their dose-rate independent response and superior spatial resolution. RCF dosimetry in low-energy ion beams requires a correction of the LET dependent film response. The relative efficiency (RE), the ratio of photon to proton dose that yields the same film darkening, is a measure for the film’s LET dependence. A direct way of RE determination is RCF irradiation with low-energy mono-energetic protons and hence, well-defined LET. However, RE is usually determined using high energy proton depth dose measurements where RE corrections require knowledge of the average LET in each depth, which can be either track (tLET) or dose (dLET) averaged. The appropriate LET concept has to be applied to allow a proper film response correction. Methods: Radiochromic EBT2 and EBT3 films were irradiated in clinical photon and proton beams. For each depth of the 200 MeV proton depth dose curve, tLET and dLET were calculated by special user routines from the Monte Carlo code FLUKA. Additional irradiations with mono-energetic low energy protons (4–20 MeV) serve as reference for the RE determination. Results: The difference of dLET and tLET increases with depth, with the dLET being almost twice as large as the tLET for the maximum depth. The comparison with mono-energetic measurements shows a good agreement of the RE for the dLET concept, while a considerably steeper drop in RE is observed when applying the tLET. Conclusion: RCF can be used as reference dosimeter for biomedical experiments with low-energy proton beams if appropriate LET corrections are applied. When using depth dose measurements from clinical proton accelerators for these corrections, the concept of dLET has to be applied. Acknowledgement: This work was funded by the DFG Cluster of Excellence ‘Munich-Centre for Advanced Photonics’ (MAP). This work was funded by the DFG Cluster of Excellence

  17. Proton transfer dynamics at membrane/water interface and mechanism of biological energy conversion.

    PubMed

    Mulkidjanian, A Y; Cherepanov, D A; Heberle, J; Junge, W

    2005-02-01

    Proton transfer between water and the interior of membrane proteins plays a key role in bioenergetics. Here we survey the mechanism of this transfer as inferred from experiments with flash-triggered enzymes capturing or ejecting protons at the membrane surface. These experiments have revealed that proton exchange between the membrane surface and the bulk water phase proceeds at > or =1 msec because of a kinetic barrier for electrically charged species. From the data analysis, the barrier height for protons could be estimated as about 0.12 eV, i.e., high enough to account for the observed retardation in proton exchange. Due to this retardation, the proton activity at the membrane surface might deviate, under steady turnover of proton pumps, from that measured in the adjoining water phase, so that the driving force for ATP synthesis might be higher than inferred from the bulk-to-bulk measurements. This is particularly relevant for alkaliphilic bacteria. The proton diffusion along the membrane surface, on the other hand, is unconstrained and fast, occurring between the neighboring enzymes at less than 1 microsec. The anisotropy of proton dynamics at the membrane surface helps prokaryotes diminish the "futile" escape of pumped protons into the external volume. In some bacteria, the inner membrane is invaginated, so that the "ejected" protons get trapped in the closed space of such intracellular membrane "sacks" which can be round or flat. The chloroplast thylakoids and the mitochondrial cristae have their origin in these intracellular structures.

  18. High and Low Energy Proton Radiation Damage in p/n InP MOCVD Solar Cells

    NASA Technical Reports Server (NTRS)

    Rybicki, George; Weinberg, Irv; Scheiman, Dave; Vargas-Aburto, Carlos; Uribe, Roberto

    1995-01-01

    InP p(+)/n/n(+) solar cells, fabricated by metal organic chemical vapor deposition, (MOCVD) were irradiated with 0.2 MeV and 10 MeV protons to a fluence of 10(exp 13)/sq cm. The power output degradation, IV behavior, carrier concentration and defect concentration were observed at intermediate points throughout the irradiations. The 0.2 MeV proton-irradiated solar cells suffered much greater and more rapid degradation in power output than those irradiated with 10 MeV protons. The efficiency losses were accompanied by larger increases in the recombination currents in the 0.2 MeV proton-irradiated solar cells. The low energy proton irradiations also had a larger impact on the series resistance of the solar cells. Despite the radiation induced damage, the carrier concentration in the base of the solar cells showed no reduction after 10 MeV or 0.2 MeV proton irradiations and even increased during irradiation with 0.2 MeV protons. In a deep level transient spectroscopy (DLTS) study of the irradiated samples, the minority carrier defects H4 and H5 at E(sub v) + 0.33 and E(sub v) + 0.52 eV and the majority carrier defects E7 and El0 at E(sub c) - 0.39 and E(sub c) - 0.74 eV, were observed. The defect introduction rates for the 0.2 MeV proton irradiations were about 20 times higher than for the 10 MeV proton irradiations. The defect El0, observed here after irradiation, has been shown to act as a donor in irradiated n-type InP and may be responsible for obscuring carrier removal. The results of this study are consistent with the much greater damage produced by low energy protons whose limited range causes them to stop in the active region of the solar cell.

  19. Photoproduction of lepton pairs in proton-nucleus and nucleus-nucleus collisions at RHIC and LHC energies

    SciTech Connect

    Moreira, B. D.; Goncalves, V. P.; De Santana Amaral, J. T.

    2013-03-25

    In this contribution we study coherent interactions as a probe of the nonlinear effects in the Quantum Electrodynamics (QED). In particular, we study the multiphoton effects in the production of leptons pairs for proton-nucleus and nucleus-nucleus collisions for heavy nuclei. In the proton-nucleus we assume the ultrarelativistic proton as a source of photons and estimate the photoproduction of lepton pairs on nuclei at RHIC and LHC energies considering the multiphoton effects associated to multiple rescattering of the projectile photon on the proton of the nucleus. In nucleus - nucleus colllisions we consider the two nuclei as a source of photons. As each scattering contributes with a factor {alpha}Z to the cross section, this contribution must be taken into account for heavy nuclei. We consider the Coulomb corrections to calculate themultiple scatterings and estimate the total cross section for muon and tau pair production in proton-nucleus and nucleus-nucleus collisions at RHIC and LHC energies.

  20. Progress on the design of the polarized Medium-energy Electron Ion Collider at JLAB

    SciTech Connect

    Lin, F.; Bogacz, A.; Brindza, P.; Camsonne, A.; Daly, E.; Derbenev, Ya. S.; Douglas, D.; Ent, R.; Gaskell, D.; Geng, R.; Grames, J.; Guo, J.; Harwood, L.; Hutton, A.; Jordan, K.; Kimber, A.; Krafft, G.; Li, R.; Michalski, T.; Morozov, V. S.; Nadel-Turonski, P.; /Jefferson Lab /Argonne /DESY /Moscow , Inst. Phys. Tech., Dolgoprydny /Dubna, JINR /Northern Illinois U. /Old Doominion U. /Novosibirsk, GOO Zaryad /SLAC /Texas A-M

    2015-07-14

    The Medium-energy Electron Ion Collider (MEIC) at JLab is designed to provide high luminosity and high polarization needed to reach new frontiers in the exploration of nuclear structure. The luminosity, exceeding 1033 cm-2s-1 in a broad range of the center-of-mass (CM) energy and maximum luminosity above 1034 cm-2s-1, is achieved by high-rate collisions of short small-emittance low-charge bunches made possible by high-energy electron cooling of the ion beam and synchrotron radiation damping of the electron beam. The polarization of light ion species (p, d, 3He) can be easily preserved and manipulated due to the unique figure-8 shape of the collider rings. A fully consistent set of parameters have been developed considering the balance of machine performance, required technical development and cost. This paper reports recent progress on the MEIC accelerator design including electron and ion complexes, integrated interaction region design, figure-8-ring-based electron and ion polarization schemes, RF/SRF systems and ERL-based high-energy electron cooling. Luminosity performance is also presented for the MEIC baseline design.

  1. Parametrized energy spectrum of cosmic-ray protons with kinetic energies down to 1 GeV

    NASA Technical Reports Server (NTRS)

    Tan, L. C.

    1985-01-01

    A new estimation of the interstellar proton spectrum is made in which the source term of primary protons is taken from shock acceleration theory and the cosmic ray propagation calculation is based on a proposed nonuniform galactic disk model.

  2. Measurement of very forward neutron energy spectra for 7 TeV proton-proton collisions at the Large Hadron Collider

    NASA Astrophysics Data System (ADS)

    Adriani, O.; Berti, E.; Bonechi, L.; Bongi, M.; Castellini, G.; D'Alessandro, R.; Del Prete, M.; Haguenauer, M.; Itow, Y.; Kasahara, K.; Kawade, K.; Makino, Y.; Masuda, K.; Matsubayashi, E.; Menjo, H.; Mitsuka, G.; Muraki, Y.; Okuno, Y.; Papini, P.; Perrot, A.-L.; Ricciarini, S.; Sako, T.; Sakurai, N.; Sugiura, Y.; Suzuki, T.; Tamura, T.; Tiberio, A.; Torii, S.; Tricomi, A.; Turner, W. C.; Zhou, Q. D.

    2015-11-01

    The Large Hadron Collider forward (LHCf) experiment is designed to use the LHC to verify the hadronic-interaction models used in cosmic-ray physics. Forward baryon production is one of the crucial points to understand the development of cosmic-ray showers. We report the neutron-energy spectra for LHC √{ s} = 7 TeV proton-proton collisions with the pseudo-rapidity η ranging from 8.81 to 8.99, from 8.99 to 9.22, and from 10.76 to infinity. The measured energy spectra obtained from the two independent calorimeters of Arm1 and Arm2 show the same characteristic feature before unfolding the detector responses. We unfolded the measured spectra by using the multidimensional unfolding method based on Bayesian theory, and the unfolded spectra were compared with current hadronic-interaction models. The QGSJET II-03 model predicts a high neutron production rate at the highest pseudo-rapidity range similar to our results, and the DPMJET 3.04 model describes our results well at the lower pseudo-rapidity ranges. However, no model perfectly explains the experimental results over the entire pseudo-rapidity range. The experimental data indicate a more abundant neutron production rate relative to the photon production than any model predictions studied here.

  3. The Proton

    NASA Astrophysics Data System (ADS)

    Canal, Carlos Garcia; Sassot, Rodolfo

    2003-10-01

    In this talk we present a collection of selected topics concerning the structure of the proton and the fundamental interactions as seen inside it. These topics have been thoroughly covered by high energy experiments with ever increasing precision in recent years and beautifully illustrate our present knowledge of the standard model.

  4. Energy latency tradeoffs for medium access and sleep scheduling in wireless sensor networks

    NASA Astrophysics Data System (ADS)

    Gang, Lu

    Wireless sensor networks are expected to be used in a wide range of applications from environment monitoring to event detection. The key challenge is to provide energy efficient communication; however, latency remains an important concern for many applications that require fast response. The central thesis of this work is that energy efficient medium access and sleep scheduling mechanisms can be designed without necessarily sacrificing application-specific latency performance. We validate this thesis through results from four case studies that cover various aspects of medium access and sleep scheduling design in wireless sensor networks. Our first effort, DMAC, is to design an adaptive low latency and energy efficient MAC for data gathering to reduce the sleep latency. We propose staggered schedule, duty cycle adaptation, data prediction and the use of more-to-send packets to enable seamless packet forwarding under varying traffic load and channel contentions. Simulation and experimental results show significant energy savings and latency reduction while ensuring high data reliability. The second research effort, DESS, investigates the problem of designing sleep schedules in arbitrary network communication topologies to minimize the worst case end-to-end latency (referred to as delay diameter). We develop a novel graph-theoretical formulation, derive and analyze optimal solutions for the tree and ring topologies and heuristics for arbitrary topologies. The third study addresses the problem of minimum latency joint scheduling and routing (MLSR). By constructing a novel delay graph, the optimal joint scheduling and routing can be solved by M node-disjoint paths algorithm under multiple channel model. We further extended the algorithm to handle dynamic traffic changes and topology changes. A heuristic solution is proposed for MLSR under single channel interference. In the fourth study, EEJSPC, we first formulate a fundamental optimization problem that provides tunable

  5. EGRET High Energy Capability and Multiwavelength Flare Studies and Solar Flare Proton Spectra

    NASA Technical Reports Server (NTRS)

    Chupp, Edward L.

    1998-01-01

    The accomplishments of the participation in the Compton Gamma Ray Observatory Guest investigator program is summarized in this report. The work involved the study of Energetic Gamma Ray Experiment Telescope (EGRET)/Total Absorption Shower Counter(TASC) flare data. The specific accomplishments were the use of the accelerator neutron measurements obtained at the University of New Hampshire to verify the TASC response function and to modify the TASC fitting program to include a high energy neutron contribution, and to determine a high energy neutron contribution to the emissions from the 1991 June 11, solar flare. The next step in the analysis of this event was doing fits to the TASC energy-loss spectra as a function of time. A significant hardening of the solar proton spectrum over time was found for the flare. Further data was obtained from the Yohkoh HXT time histories and images for the 1991 October 27 flare. The results to date demonstrate that the TASC spectral analysis contributes crucial information on the particle spectrum interacting at the Sun. The report includes a paper accepted for publication, a draft of a paper to be delivered at the 26th International Cosmic Ray Conference and an abstract of a paper to be presented at the Meeting of the American Physical Society.

  6. {sup 7}Li(p,n) NUCLEAR DATA LIBRARY FOR INCIDENT PROTON ENERGIES TO 150 MEV

    SciTech Connect

    S. MASHNIK; ET AL

    2000-11-01

    Researchers at Los Alamos National Laboratory are considering the possibility of using the Low Energy Demonstration Accelerator (LEDA), constructed at LANSCE for the Accelerator Production of Tritium program (APT), as a neutron source. Evaluated nuclear data are needed for the p+{sup 7}Li reaction, to predict neutron production from thin and thick lithium targets. In this report we describe evaluation methods that make use of experimental data, and nuclear model calculations, to develop an ENDF-formatted data library for incident protons with energies up to 150 MeV. The important {sup 7}Li(p,n{sub 0}) and {sup 7}Li(p,n{sub 1}) reactions are evaluated from the experimental data, with their angular distributions represented using Lengendre polynomial expansions. The decay of the remaining reaction flux is estimated from GNASH nuclear model calculations. This leads to the emission of lower-energy neutrons and other charged particles and gamma-rays from preequilibrium and compound nucleus decay processes. The evaluated ENDF-data are described in detail, and illustrated in numerous figures. We also illustrate the use of these data in a representative application by a radiation transport simulation with the code MCNPX.

  7. Study of the energy dependence of the underlying event in proton-antiproton collisions

    SciTech Connect

    Nodulman, L.; Aaltonen, T; Albrow, M; Amerio, S.; Amidei, D; Anastassov, A.; Annovi, A; Antos, J; Apollinari, G.; Appel, J A; Arisawa, T

    2015-11-23

    We study charged particle production (p(T) > 0.5 GeV/c, vertical bar eta vertical bar < 0.8) in proton-antiproton collisions at total center-of-mass energies root s = 300 GeV, 900 GeV, and 1.96 TeV. We use the direction of the charged particle with the largest transverse momentum in each event to define three regions of eta - phi space: "toward", "away", and "transverse." The average number and the average scalar pT sum of charged particles in the transverse region are sensitive to the modeling of the "underlying event." The transverse region is divided into a MAX and MIN transverse region, which helps separate the "hard component" (initial and final-state radiation) from the "beam-beam remnant" and multiple parton interaction components of the scattering. The center-of-mass energy dependence of the various components of the event is studied in detail. The data presented here can be used to constrain and improve QCD Monte Carlo models, resulting in more precise predictions at the LHC energies of 13 and 14 TeV.

  8. Study of the energy dependence of the underlying event in proton-antiproton collisions

    NASA Astrophysics Data System (ADS)

    Aaltonen, T.; Albrow, M.; Amerio, S.; Amidei, D.; Anastassov, A.; Annovi, A.; Antos, J.; Apollinari, G.; Appel, J. A.; Arisawa, T.; Artikov, A.; Asaadi, J.; Ashmanskas, W.; Auerbach, B.; Aurisano, A.; Azfar, F.; Badgett, W.; Bae, T.; Barbaro-Galtieri, A.; Barnes, V. E.; Barnett, B. A.; Barria, P.; Bartos, P.; Bauce, M.; Bedeschi, F.; Behari, S.; Bellettini, G.; Bellinger, J.; Benjamin, D.; Beretvas, A.; Bhatti, A.; Bland, K. R.; Blumenfeld, B.; Bocci, A.; Bodek, A.; Bortoletto, D.; Boudreau, J.; Boveia, A.; Brigliadori, L.; Bromberg, C.; Brucken, E.; Budagov, J.; Budd, H. S.; Burkett, K.; Busetto, G.; Bussey, P.; Butti, P.; Buzatu, A.; Calamba, A.; Camarda, S.; Campanelli, M.; Canelli, F.; Carls, B.; Carlsmith, D.; Carosi, R.; Carrillo, S.; Casal, B.; Casarsa, M.; Castro, A.; Catastini, P.; Cauz, D.; Cavaliere, V.; Cerri, A.; Cerrito, L.; Chen, Y. C.; Chertok, M.; Chiarelli, G.; Chlachidze, G.; Cho, K.; Chokheli, D.; Clark, A.; Clarke, C.; Convery, M. E.; Conway, J.; Corbo, M.; Cordelli, M.; Cox, C. A.; Cox, D. J.; Cremonesi, M.; Cruz, D.; Cuevas, J.; Culbertson, R.; d'Ascenzo, N.; Datta, M.; de Barbaro, P.; Demortier, L.; Deninno, M.; D'Errico, M.; Devoto, F.; Di Canto, A.; Di Ruzza, B.; Dittmann, J. R.; Donati, S.; D'Onofrio, M.; Dorigo, M.; Driutti, A.; Ebina, K.; Edgar, R.; Elagin, A.; Erbacher, R.; Errede, S.; Esham, B.; Farrington, S.; Fernández Ramos, J. P.; Field, R.; Flanagan, G.; Forrest, R.; Franklin, M.; Freeman, J. C.; Frisch, H.; Funakoshi, Y.; Galloni, C.; Garfinkel, A. F.; Garosi, P.; Gerberich, H.; Gerchtein, E.; Giagu, S.; Giakoumopoulou, V.; Gibson, K.; Ginsburg, C. M.; Giokaris, N.; Giromini, P.; Glagolev, V.; Glenzinski, D.; Gold, M.; Goldin, D.; Golossanov, A.; Gomez, G.; Gomez-Ceballos, G.; Goncharov, M.; González López, O.; Gorelov, I.; Goshaw, A. T.; Goulianos, K.; Gramellini, E.; Grosso-Pilcher, C.; Group, R. C.; Guimaraes da Costa, J.; Hahn, S. R.; Han, J. Y.; Happacher, F.; Hara, K.; Hare, M.; Harr, R. F.; Harrington-Taber, T.; Hatakeyama, K.; Hays, C.; Heinrich, J.; Herndon, M.; Hocker, A.; Hong, Z.; Hopkins, W.; Hou, S.; Hughes, R. E.; Husemann, U.; Hussein, M.; Huston, J.; Introzzi, G.; Iori, M.; Ivanov, A.; James, E.; Jang, D.; Jayatilaka, B.; Jeon, E. J.; Jindariani, S.; Jones, M.; Joo, K. K.; Jun, S. Y.; Junk, T. R.; Kambeitz, M.; Kamon, T.; Karchin, P. E.; Kasmi, A.; Kato, Y.; Ketchum, W.; Keung, J.; Kilminster, B.; Kim, D. H.; Kim, H. S.; Kim, J. E.; Kim, M. J.; Kim, S. H.; Kim, S. B.; Kim, Y. J.; Kim, Y. K.; Kimura, N.; Kirby, M.; Knoepfel, K.; Kondo, K.; Kong, D. J.; Konigsberg, J.; Kotwal, A. V.; Kreps, M.; Kroll, J.; Kruse, M.; Kuhr, T.; Kurata, M.; Laasanen, A. T.; Lammel, S.; Lancaster, M.; Lannon, K.; Latino, G.; Lee, H. S.; Lee, J. S.; Leo, S.; Leone, S.; Lewis, J. D.; Limosani, A.; Lipeles, E.; Lister, A.; Liu, H.; Liu, Q.; Liu, T.; Lockwitz, S.; Loginov, A.; Lucchesi, D.; Lucá, A.; Lueck, J.; Lujan, P.; Lukens, P.; Lungu, G.; Lys, J.; Lysak, R.; Madrak, R.; Maestro, P.; Malik, S.; Manca, G.; Manousakis-Katsikakis, A.; Marchese, L.; Margaroli, F.; Marino, P.; Matera, K.; Mattson, M. E.; Mazzacane, A.; Mazzanti, P.; McNulty, R.; Mehta, A.; Mehtala, P.; Mesropian, C.; Miao, T.; Mietlicki, D.; Mitra, A.; Miyake, H.; Moed, S.; Moggi, N.; Moon, C. S.; Moore, R.; Morello, M. J.; Mukherjee, A.; Muller, Th.; Murat, P.; Mussini, M.; Nachtman, J.; Nagai, Y.; Naganoma, J.; Nakano, I.; Napier, A.; Nett, J.; Neu, C.; Nigmanov, T.; Nodulman, L.; Noh, S. Y.; Norniella, O.; Oakes, L.; Oh, S. H.; Oh, Y. D.; Oksuzian, I.; Okusawa, T.; Orava, R.; Ortolan, L.; Pagliarone, C.; Palencia, E.; Palni, P.; Papadimitriou, V.; Parker, W.; Pauletta, G.; Paulini, M.; Paus, C.; Phillips, T. J.; Piacentino, G.; Pianori, E.; Pilot, J.; Pitts, K.; Plager, C.; Pondrom, L.; Poprocki, S.; Potamianos, K.; Pranko, A.; Prokoshin, F.; Ptohos, F.; Punzi, G.; Redondo Fernández, I.; Renton, P.; Rescigno, M.; Rimondi, F.; Ristori, L.; Robson, A.; Rodriguez, T.; Rolli, S.; Ronzani, M.; Roser, R.; Rosner, J. L.; Ruffini, F.; Ruiz, A.; Russ, J.; Rusu, V.; Sakumoto, W. K.; Sakurai, Y.; Santi, L.; Sato, K.; Saveliev, V.; Savoy-Navarro, A.; Schlabach, P.; Schmidt, E. E.; Schwarz, T.; Scodellaro, L.; Scuri, F.; Seidel, S.; Seiya, Y.; Semenov, A.; Sforza, F.; Shalhout, S. Z.; Shears, T.; Shepard, P. F.; Shimojima, M.; Shochet, M.; Shreyber-Tecker, I.; Simonenko, A.; Sliwa, K.; Smith, J. R.; Snider, F. D.; Song, H.; Sorin, V.; St. Denis, R.; Stancari, M.; Stentz, D.; Strologas, J.; Sudo, Y.; Sukhanov, A.; Suslov, I.; Takemasa, K.; Takeuchi, Y.; Tang, J.; Tecchio, M.; Teng, P. K.; Thom, J.; Thomson, E.; Thukral, V.; Toback, D.; Tokar, S.; Tollefson, K.; Tomura, T.; Tonelli, D.; Torre, S.; Torretta, D.; Totaro, P.; Trovato, M.; Ukegawa, F.; Uozumi, S.; Vázquez, F.; Velev, G.; Vellidis, C.; Vernieri, C.; Vidal, M.; Vilar, R.; Vizán, J.; Vogel, M.; Volpi, G.; Wagner, P.; Wallny, R.; Wang, S. M.; Waters, D.; Wester, W. C.; Whiteson, D.; Wicklund, A. B.; Wilbur, S.; Williams, H. H.; Wilson, J. S.; Wilson, P.; Winer, B. L.; Wittich, P.; Wolbers, S.; Wolfe, H.; Wright, T.; Wu, X.; Wu, Z.; Yamamoto, K.; Yamato, D.; Yang, T.; Yang, U. K.; Yang, Y. C.; Yao, W.-M.; Yeh, G. P.; Yi, K.; Yoh, J.; Yorita, K.; Yoshida, T.; Yu, G. B.; Yu, I.; Zanetti, A. M.; Zeng, Y.; Zhou, C.; Zucchelli, S.; CDF Collaboration

    2015-11-01

    We study charged particle production (pT>0.5 GeV /c , |η |<0.8 ) in proton-antiproton collisions at total center-of-mass energies √{s }=300 GeV , 900 GeV, and 1.96 TeV. We use the direction of the charged particle with the largest transverse momentum in each event to define three regions of η -ϕ space: "toward", "away", and "transverse." The average number and the average scalar pT sum of charged particles in the transverse region are sensitive to the modeling of the "underlying event." The transverse region is divided into a MAX and MIN transverse region, which helps separate the "hard component" (initial and final-state radiation) from the "beam-beam remnant" and multiple parton interaction components of the scattering. The center-of-mass energy dependence of the various components of the event is studied in detail. The data presented here can be used to constrain and improve QCD Monte Carlo models, resulting in more precise predictions at the LHC energies of 13 and 14 TeV.

  9. Performance of solenoids versus quadrupoles in focusing and energy selection of laser accelerated protons

    NASA Astrophysics Data System (ADS)

    Hofmann, Ingo

    2013-04-01

    Using laser accelerated protons or ions for various applications—for example in particle therapy or short-pulse radiographic diagnostics—requires an effective method of focusing and energy selection. We derive an analytical scaling for the performance of a solenoid compared with a doublet/triplet as function of the energy, which is confirmed by TRACEWIN simulations. Generally speaking, the two approaches are equivalent in focusing capability, if parameters are such that the solenoid length approximately equals its diameter. The scaling also shows that this is usually not the case above a few MeV; consequently, a solenoid needs to be pulsed or superconducting, whereas the quadrupoles can remain conventional. It is also important that the transmission of the triplet is found only 25% lower than that of the equivalent solenoid. Both systems are equally suitable for energy selection based on their chromatic effect as is shown using an initial distribution following the RPA simulation model by Yan et al. [Phys. Rev. Lett. 103, 135001 (2009PRLTAO0031-900710.1103/PhysRevLett.103.135001].

  10. Explanation of the local galactic cosmic ray energy spectra measured by Voyager 1. I. Protons

    SciTech Connect

    Schlickeiser, R.; Kempf, A.; Webber, W. R. E-mail: ank@tp4.rub.de

    2014-05-20

    Almost exactly 100 yr after the original discovery of cosmic rays, the V1 spacecraft has observed, for the first time, the local interstellar medium energy spectra of cosmic ray H, He, C/O nuclei at nonrelativistic kinetic energies, after leaving the heliosphere modulation region on 2012 August 25. We explain these observations by modeling the propagation of these particles in the local Galactic environment with an updated steady-state spatial diffusion model including all particle momentum losses with the local interstellar gas (Coulomb/ionization, pion production, adiabatic deceleration, and fragmentation interactions). Excellent agreement with the V1 cosmic ray H observations is obtained if the solar system resides within a spatially homogeneous layer of distributed cosmic ray sources injecting the same momentum power law ∝p {sup –s} with s = 2.24 ± 0.12. The best fit to the V1 H observations also provides an estimate of the characteristic break kinetic energy T{sub C} = 116 ± 27 MeV, representing the transition from ionization/Coulomb energy losses at low energies to pion production and adiabatic deceleration losses in a Galactic wind at high energies. As the determined value is substantially smaller than 217 MeV in the absence of adiabatic deceleration, our results prove the existence of a Galactic wind in the local Galactic environment.

  11. A Pair Production Telescope for Medium-Energy Gamma-Ray Polarimetry

    NASA Technical Reports Server (NTRS)

    Hunter, Stanley D.; Bloser, Peter F.; Depaola, Gerardo; Dion, Michael P.; DeNolfo, Georgia A.; Hanu, Andrei; Iparraguirre, Marcos; Legere, Jason; Longo, Francesco; McConnell, Mark L.; Nowicki, Suzanne F.; Ryan, James M.; Son, Seunghee; Stecker, Floyd W.

    2014-01-01

    We describe the science motivation and development of a pair production telescope for medium-energy (approximately 5-200 Mega electron Volts) gamma-ray polarimetry. Our instrument concept, the Advanced Energetic Pair Telescope (AdEPT), takes advantage of the Three-Dimensional Track Imager, a low-density gaseous time projection chamber, to achieve angular resolution within a factor of two of the pair production kinematics limit (approximately 0.6 deg at 70 Mega electron Volts), continuum sensitivity comparable with the Fermi-LAT front detector (is less than 3 x 10(exp -6) Mega electron Volts per square centimeter per second at 70 Mega electron Volts), and minimum detectable polarization less than 10% for a 10 milliCrab source in 10(exp 6) s.

  12. Software-Defined Solutions for Managing Energy Use in Small to Medium Sized Commercial Buildings

    SciTech Connect

    Peffer, Therese; Blumstein, Carl; Culler, David; Modera, Mark; Meier, Alan

    2015-09-10

    The Project uses state-of-the-art computer science to extend the benefits of Building Automation Systems (BAS) typically found in large buildings (>100,000 square foot) to medium-sized commercial buildings (<50,000 sq ft). The BAS developed in this project, termed OpenBAS, uses an open-source and open software architecture platform, user interface, and plug-and-play control devices to facilitate adoption of energy efficiency strategies in the commercial building sector throughout the United States. At the heart of this “turn key” BAS is the platform with three types of controllers—thermostat, lighting controller, and general controller—that are easily “discovered” by the platform in a plug-and-play fashion. The user interface showcases the platform and provides the control system set-up, system status display and means of automatically mapping the control points in the system.

  13. Damage Processes In MgO Irradiated With Medium-energy Heavy Ions

    SciTech Connect

    Moll, Sandra J.; Zhang, Y.; Debelle, A.; Thome, Lionel; Crocombette, J.-P.; Zhu, Zihua; Jagielski, Jacek; Weber, William J.

    2015-04-01

    The micro-structural modifications produced in MgO single crystals exposed to medium-energy heavy ions (1.2-MeV Au) were investigated using Rutherford backscattering spectrometry in channeling geometry coupled to Monte-Carlo analyses, secondary ion mass spectrometry, X-ray diffraction and transmission electron microscopy. The damage accumulation and the elastic strain variation were interpreted in the framework of the multi-step damage accumulation (MSDA) model. Both build-ups follow a multi-step process similar to that recently observed for ion-irradiated yttria-stabilized zirconia (YSZ) single crystals. However, in MgO, an unexpectedly high disorder level occurs far beyond the theoretical damage distribution. These results strongly suggest that the migration of defects created in the near-surface layer is most likely at the origin of the broadening of the damage depth distribution in MgO.

  14. A Pair Production Telescope for Medium-Energy Gamma-Ray Polarimetry

    SciTech Connect

    Hunter , Stanley D.; Bloser, Peter F.; Depaola, Gerardo O.; Dion, Michael P.; DeNolfo, Georgia A.; Hanu, Andrei; Iparraguirre, Marcos; Legere, Jason; Longo, Francesco; McConnell, Mark L.; Nowicki, Suzanne F.; Ryan, James M.; Son, Seunghee; Stecker, Floyd W.

    2014-08-01

    We describe the science motivation and development of a pair production telescope for medium-13 energy gamma-ray polarimetry. Our instrument concept, the Advanced Energetic Pair Telescope 14 (AdEPT), takes advantage of the Three-Dimensional Track Imager, a low-density gaseous time 15 projection chamber, to achieve angular resolution within a factor of two of the pair production 16 kinematics limit (~0.6° at 70 MeV), continuum sensitivity comparable with the Fermi-LAT front 17 detector (<3×10-6 MeV cm-2 s-1 at 70 MeV), and minimum detectable polarization less than 10% 18 for a 10 millicrab source in 106 seconds.

  15. Quantum chemical approach for condensed-phase thermochemistry (III): Accurate evaluation of proton hydration energy and standard hydrogen electrode potential

    NASA Astrophysics Data System (ADS)

    Ishikawa, Atsushi; Nakai, Hiromi

    2016-04-01

    Gibbs free energy of hydration of a proton and standard hydrogen electrode potential were evaluated using high-level quantum chemical calculations. The solvent effect was included using the cluster-continuum model, which treated short-range effects by quantum chemical calculations of proton-water complexes, and the long-range effects by a conductor-like polarizable continuum model. The harmonic solvation model (HSM) was employed to estimate enthalpy and entropy contributions due to nuclear motions of the clusters by including the cavity-cluster interactions. Compared to the commonly used ideal gas model, HSM treatment significantly improved the contribution of entropy, showing a systematic convergence toward the experimental data.

  16. High-efficiency deflection of high energy protons due to channeling along the <110> axis of a bent silicon crystal

    NASA Astrophysics Data System (ADS)

    Scandale, W.; Arduini, G.; Butcher, M.; Cerutti, F.; Garattini, M.; Gilardoni, S.; Lechner, A.; Masi, A.; Mirarchi, D.; Montesano, S.; Redaelli, S.; Rossi, R.; Smirnov, G.; Breton, D.; Burmistrov, L.; Chaumat, V.; Dubos, S.; Maalmi, J.; Puill, V.; Stocchi, A.; Bagli, E.; Bandiera, L.; Germogli, G.; Guidi, V.; Mazzolari, A.; Dabagov, S.; Murtas, F.; Addesa, F.; Cavoto, G.; Iacoangeli, F.; Galluccio, F.; Afonin, A. G.; Chesnokov, Yu. A.; Durum, A. A.; Maisheev, V. A.; Sandomirskiy, Yu. E.; Yanovich, A. A.; Kovalenko, A. D.; Taratin, A. M.; Denisov, A. S.; Gavrikov, Yu. A.; Ivanov, Yu. M.; Lapina, L. P.; Malyarenko, L. G.; Skorobogatov, V. V.; James, T.; Hall, G.; Pesaresi, M.; Raymond, M.

    2016-09-01

    A deflection efficiency of about 61% was observed for 400 GeV/c protons due to channeling, most strongly along the <110> axis of a bent silicon crystal. It is comparable with the deflection efficiency in planar channeling and considerably larger than in the case of the <111> axis. The measured probability of inelastic nuclear interactions of protons in channeling along the <110> axis is only about 10% of its amorphous level whereas in channeling along the (110) planes it is about 25%. High efficiency deflection and small beam losses make this axial orientation of a silicon crystal a useful tool for the beam steering of high energy charged particles.

  17. Why baryons are Yang-Mills magnetic monopoles, validated by nuclear binding energies and proton and neutron masses

    NASA Astrophysics Data System (ADS)

    Yablon, Jay R.

    2013-10-01

    Evidence is summarized from four recent papers that baryons including protons and neutrons are magnetic monopoles of non-commuting Yang-Mills gauge theories: 1) Protons and neutrons are ``resonant cavities'' with binding energies determined strictly by the masses of the quarks they contain. This is proven true at parts-per million accuracy for each of the 2H, 3H,3He, 4He binding energies and the neutron minus proton mass difference. 2) Respectively, each free proton and neutron contains 7.64 MeV and 9.81 MeV of mass/energy used to confine its quarks. When these nucleons bind, some, never all, of this energy is released and the mass deficit goes into binding. The balance continues to confine quarks. 56Fe releases 99.8429% of this energy for binding, more than any other nuclide. 3) Once we consider the Fermi vev one also finds an entirely theoretical explanation of proton and neutron masses, which also connects within experimental errors to the CKM quark mixing angles. 4) A related GUT explains fermion generation replication based on generator loss during symmetry breaking, and answers Rabi's question ``who ordered this?'' 5) Nuclear physics is governed by combining Maxwell's two classical equations into one equation using non-commuting gauge fields in view of Dirac theory and Fermi-Dirac-Pauli Exclusion. 6) Atoms themselves are core magnetic charges (nucleons) paired with orbital electric charges (electrons and elusive neutrinos), with the periodic table itself revealing an electric/magnetic symmetry of Maxwell's equations often pondered but heretofore unrecognized for a century and a half.

  18. Proton Acceleration to Therapeutic Energies with Ultra-Intense Ultra-Clean and Ultra-Short Laser Pulses

    SciTech Connect

    Reed, S. A.; Bulanov, S. S.; Chvykov, V.; Kalinchenko, G.; Matsuoka, T.; Rousseau, P.; Yanovsky, V.; Maksimchuk, A.; Brantov, A.; Bychenkov, V. Yu.; Litzenberg, D. W.

    2006-11-27

    The acceleration of protons to therapeutic energies of over 200 MeV by short-pulse, high-intensity lasers requires very high temporal intensity contrast. We describe improvements to the contrast ratio of the laser pulse produced by a multi-terawatt chirped pulsed amplification (CPA) Ti:sapphire laser for the application of proton acceleration. The modified cross-polarized wave generation (XPW) technique has been implemented on the Hercules laser at the University of Michigan to reject the low-intensity amplified spontaneous emission (ASE) preceding the main laser pulse. We demonstrate that by using two BaF2 crystals, the XPW technique yields a 10-11 contrast ratio between the main peak and the ASE for a 50 TW laser system which can be maintained up to 500 TW. Such contrast may be sufficient for a preplasma-free interaction of 225 TW laser pulses with sub-micron thick foils at an intensity of {approx}10{sup 22} W/cm{sup 2}. Particle-in-cell (PIC) simulations were conducted under the anticipated experimental conditions: 6.75 J, 30 fs laser pulse without a prepulse, focused to a spot size of 1.2 microns (FWHM) on thin foils of varying thickness. The performed PIC simulations show that for a 0.2 {mu}m thick hydrogen foil protons with energy up to 200 MeV can be produced. In the case of the two-layer aluminum-hydrogen foil, the maximum energy of accelerated protons is about 150 MeV, but the flux-energy spectrum of the accelerated protons has a narrow peak at high energies, which may be more advantageous for medical applications.

  19. Linear Energy Transfer-Guided Optimization in Intensity Modulated Proton Therapy: Feasibility Study and Clinical Potential

    SciTech Connect

    Giantsoudi, Drosoula; Grassberger, Clemens; Craft, David; Niemierko, Andrzej; Trofimov, Alexei; Paganetti, Harald

    2013-09-01

    Purpose: To investigate the feasibility and potential clinical benefit of linear energy transfer (LET) guided plan optimization in intensity modulated proton therapy (IMPT). Methods and Materials: A multicriteria optimization (MCO) module was used to generate a series of Pareto-optimal IMPT base plans (BPs), corresponding to defined objectives, for 5 patients with head-and-neck cancer and 2 with pancreatic cancer. A Monte Carlo platform was used to calculate dose and LET distributions for each BP. A custom-designed MCO navigation module allowed the user to interpolate between BPs to produce deliverable Pareto-optimal solutions. Differences among the BPs were evaluated for each patient, based on dose–volume and LET–volume histograms and 3-dimensional distributions. An LET-based relative biological effectiveness (RBE) model was used to evaluate the potential clinical benefit when navigating the space of Pareto-optimal BPs. Results: The mean LET values for the target varied up to 30% among the BPs for the head-and-neck patients and up to 14% for the pancreatic cancer patients. Variations were more prominent in organs at risk (OARs), where mean LET values differed by a factor of up to 2 among the BPs for the same patient. An inverse relation between dose and LET distributions for the OARs was typically observed. Accounting for LET-dependent variable RBE values, a potential improvement on RBE-weighted dose of up to 40%, averaged over several structures under study, was noticed during MCO navigation. Conclusions: We present a novel strategy for optimizing proton therapy to maximize dose-averaged LET in tumor targets while simultaneously minimizing dose-averaged LET in normal tissue structures. MCO BPs show substantial LET variations, leading to potentially significant differences in RBE-weighted doses. Pareto-surface navigation, using both dose and LET distributions for guidance, provides the means for evaluating a large variety of deliverable plans and aids in

  20. Probability distribution of the free energy of a directed polymer in a random medium.

    PubMed

    Brunet, E; Derrida, B

    2000-06-01

    We calculate exactly the first cumulants of the free energy of a directed polymer in a random medium for the geometry of a cylinder. By using the fact that the nth moment of the partition function is given by the ground-state energy of a quantum problem of n interacting particles on a ring of length L, we write an integral equation allowing to expand these moments in powers of the strength of the disorder gamma or in powers of n. For n small and n approximately (Lgamma)(-1/2), the moments take a scaling form which allows us to describe all the fluctuations of order 1/L of the free energy per unit length of the directed polymer. The distribution of these fluctuations is the same as the one found recently in the asymmetric exclusion process, indicating that it is characteristic of all the systems described by the Kardar-Parisi-Zhang equation in 1+1 dimensions. PMID:11088374

  1. Towards smart energy systems: application of kernel machine regression for medium term electricity load forecasting.

    PubMed

    Alamaniotis, Miltiadis; Bargiotas, Dimitrios; Tsoukalas, Lefteri H

    2016-01-01

    Integration of energy systems with information technologies has facilitated the realization of smart energy systems that utilize information to optimize system operation. To that end, crucial in optimizing energy system operation is the accurate, ahead-of-time forecasting of load demand. In particular, load forecasting allows planning of system expansion, and decision making for enhancing system safety and reliability. In this paper, the application of two types of kernel machines for medium term load forecasting (MTLF) is presented and their performance is recorded based on a set of historical electricity load demand data. The two kernel machine models and more specifically Gaussian process regression (GPR) and relevance vector regression (RVR) are utilized for making predictions over future load demand. Both models, i.e., GPR and RVR, are equipped with a Gaussian kernel and are tested on daily predictions for a 30-day-ahead horizon taken from the New England Area. Furthermore, their performance is compared to the ARMA(2,2) model with respect to mean average percentage error and squared correlation coefficient. Results demonstrate the superiority of RVR over the other forecasting models in performing MTLF.

  2. Energy cost based design optimization method for medium temperature CPC collectors

    NASA Astrophysics Data System (ADS)

    Horta, Pedro; Osório, Tiago; Collares-Pereira, Manuel

    2016-05-01

    CPC collectors, approaching the ideal concentration limits established by non-imaging optics, can be designed to have such acceptance angles enabling fully stationary designs, useful for applications in the low temperature range (T < 100°C). Their use in the medium temperature range (100°C < T < 250°C) typically requires higher concentration factors in turn requiring seasonal tracking strategies. Considering the CPC design options in terms of effective concentration factor, truncation, concentrator height, mirror perimeter, seasonal tracking, trough spacing, etc., an energy cost function based design optimization method is presented in this article. Accounting for the impact of the design on its optical (optical efficiency, Incidence Angle Modifier, diffuse acceptance) and thermal performances (dependent on the concentration factor), the optimization function integrates design (e.g. mirror area, frame length, trough spacing/shading), concept (e.g. rotating/stationary components, materials) and operation (e.g. O&M, tilt shifts and tracking strategy) costs into a collector specific energy cost function, in €/(kWh.m2). The use of such function stands for a location and operating temperature dependent design optimization procedure, aiming at the lowest solar energy cost. Illustrating this approach, optimization results will be presented for a (tubular) evacuated absorber CPC design operating in Morocco.

  3. Towards smart energy systems: application of kernel machine regression for medium term electricity load forecasting.

    PubMed

    Alamaniotis, Miltiadis; Bargiotas, Dimitrios; Tsoukalas, Lefteri H

    2016-01-01

    Integration of energy systems with information technologies has facilitated the realization of smart energy systems that utilize information to optimize system operation. To that end, crucial in optimizing energy system operation is the accurate, ahead-of-time forecasting of load demand. In particular, load forecasting allows planning of system expansion, and decision making for enhancing system safety and reliability. In this paper, the application of two types of kernel machines for medium term load forecasting (MTLF) is presented and their performance is recorded based on a set of historical electricity load demand data. The two kernel machine models and more specifically Gaussian process regression (GPR) and relevance vector regression (RVR) are utilized for making predictions over future load demand. Both models, i.e., GPR and RVR, are equipped with a Gaussian kernel and are tested on daily predictions for a 30-day-ahead horizon taken from the New England Area. Furthermore, their performance is compared to the ARMA(2,2) model with respect to mean average percentage error and squared correlation coefficient. Results demonstrate the superiority of RVR over the other forecasting models in performing MTLF. PMID:26835237

  4. Medium Effects in Parton Distributions

    SciTech Connect

    William Detmold, Huey-Wen Lin

    2011-12-01

    A defining experiment of high-energy physics in the 1980s was that of the EMC collaboration where it was first observed that parton distributions in nuclei are non-trivially related to those in the proton. This result implies that the presence of the nuclear medium plays an important role and an understanding of this from QCD has been an important goal ever since Here we investigate analogous, but technically simpler, effects in QCD and examine how the lowest moment of the pion parton distribution is modified by the presence of a Bose-condensed gas of pions or kaons.

  5. Total fission cross section of {sup 181}Ta and {sup 208}Pb induced by protons at relativistic energies

    SciTech Connect

    Ayyad, Y.; Benlliure, J.; Casarejos, E.; Schmidt, K. H.; Jurado, B.; Pol, H. A.; Ricciardi, M. V.; Pleskac, R.; Enqvist, T.; Rejmund, F.; Giot, L.; Henzl, V.; Lukic, S.; Ngoc, S. N.; Boudard, A.; Leray, S.; Kurtukian, T.; Schmitt, C.; Henzlova, D.; Paradela, C.; Bacquias, A.; Loureiro, D. P.; Foehr, V.; Tarrio, D.; Kezzar, K.

    2011-07-01

    Total fission cross section induced by protons in {sup 181}Ta and {sup 208}Pb at energies in the range of 300 to 1000 A MeV have been measured at GSI (Germany) using the inverse kinematics technique. A dedicated setup with high efficiency made it possible to determine these cross sections with high accuracy. The new data seed light in the controversial results obtained so far and contribute to the understanding of the fission process at high excitation energies. (authors)

  6. RBE for late somatic effects in mice irradiated with 60 MeV protons relative to X-rays.

    NASA Technical Reports Server (NTRS)

    Darden, E. B., Jr.; Clapp, N. K.; Bender, R. S.; Jernigan, M. C.; Upton, A. C.

    1971-01-01

    Investigation of the relative biological effectiveness of energetic protons for the induction of somatic effects in a mammal (mice) following whole body irradiation. The proton energy used approximates the mean energy for proton spectra accompanying solar events. The effects on longevity and the incidence of major neoplastic diseases are summarized. The results obtained suggest that medium energy proton irradiation is no more effective, and on the whole, probably less effective, than conventional X radiation for the induction of late radiation effects in the mouse.

  7. Production of proton beams with narrow-band energy spectra from laser-irradiated ultrathin foils

    SciTech Connect

    Robinson, A. P. L; Gibbon, P.

    2007-01-15

    Three-dimensional gridless particle simulations of proton acceleration via irradiation of a very thin foil by a short-pulse, high-intensity laser have been performed to evaluate recently proposed microstructured target configurations. It is found that a pure proton microdot target does not by itself result in a quasimonoenergetic proton beam. Such a beam can only be produced with a very lightly doped target, in qualitative agreement with one-dimensional theory. The simulations suggest that beam quality in current experiments could be dramatically improved by choosing microdot compositions with a 5-10 times lower proton fraction.

  8. On the nucleon effective mass role to the high energy proton spallation reactions

    NASA Astrophysics Data System (ADS)

    Santos, B. M.; Pinheiro, A. R. C.; Gonçalves, M.; Duarte, S. B.; Cabral, R. G.

    2016-04-01

    We explore the effect of the nucleon effective mass to the dynamic evolution of the rapid phase of proton-nucleus spallation reactions. The analysis of the relaxation time for the non-equilibrium phase is studied by variations in the effective mass parameter. We determine the final excitation energy of the hot residual nucleus at the end of cascade phase and the de-excitation of the nuclear system is carried out considering the competition of particle evaporation and fission processes. It was shown that the excitation energy depends of the hot compound residual nucleus at the end of the rapid phase on the changing effective mass. The multiplicity of particles was also analyzed in cascade and evaporation phase of the reaction. The use of nucleon effective mass during cascade phase can be considered as an effect of the many-body nuclear interactions not included explicitly in a treatment to the nucleon-nucleon interaction inside the nucleus. This procedure represents a more realistic scenario to obtain the neutron multiplicity generated in this reaction, which is a benchmark for the calculation of the neutronic in the ADS reactors.

  9. A study of the energy dependence of the underlying event in proton-antiproton collisions

    DOE PAGES

    Aaltonen, T.

    2015-11-23

    We study charged particle production (pT > 0.5 GeV/c, |η| < 0.8) in proton-antiproton collisions at 300 GeV, 900 GeV, and 1.96 TeV. We use the direction of the charged particle with the largest transverse momentum in each event to define three regions of η-Φspace; “toward”, “away”, and “transverse”. Furthermore, the average number and the average scalar pT sum of charged particles in the transverse region are sensitive to the modeling of the “underlying event”. The transverse region is divided into a MAX and MIN transverse region, which helps separate the “hard component” (initial and final-state radiation) from the “beam-beammore » remnant” and multiple parton interaction components of the scattering. We found that the center-of-mass energy dependence of the various components of the event are studied in detail. The data presented here can be used to constrain and improve QCD Monte Carlo models, resulting in more precise predictions at the LHC energies of 13 and 14 TeV.« less

  10. A study of the energy dependence of the underlying event in proton-antiproton collisions

    SciTech Connect

    Aaltonen, T.

    2015-11-23

    We study charged particle production (pT > 0.5 GeV/c, |η| < 0.8) in proton-antiproton collisions at 300 GeV, 900 GeV, and 1.96 TeV. We use the direction of the charged particle with the largest transverse momentum in each event to define three regions of η-Φspace; “toward”, “away”, and “transverse”. Furthermore, the average number and the average scalar pT sum of charged particles in the transverse region are sensitive to the modeling of the “underlying event”. The transverse region is divided into a MAX and MIN transverse region, which helps separate the “hard component” (initial and final-state radiation) from the “beam-beam remnant” and multiple parton interaction components of the scattering. We found that the center-of-mass energy dependence of the various components of the event are studied in detail. The data presented here can be used to constrain and improve QCD Monte Carlo models, resulting in more precise predictions at the LHC energies of 13 and 14 TeV.

  11. Energy dependent track structure parametrisations for protons and carbon ions based on nanometric simulations

    NASA Astrophysics Data System (ADS)

    Alexander, Frauke; Villagrasa, Carmen; Rabus, Hans; Wilkens, Jan J.

    2015-09-01

    The BioQuaRT project within the European Metrology Research Programme aims at correlating ion track structure characteristics with the biological effects of radiation and develops measurement and simulation techniques for determining ion track structure on different length scales from about 2 nm to about 10 μm. Within this framework, we investigate methods to translate track-structure quantities derived on a nanometre scale to macroscopic dimensions. Input data sets were generated by simulations of ion tracks of protons and carbon ions in liquid water using the Geant 4 Monte Carlo toolkit with the Geant4-DNA processes. Based on the energy transfer points - recorded with nanometre resolution - we investigated parametrisations of overall properties of ion track structure. Three different track structure parametrisations have been developed using the distances to the 10 next neighbouring ionisations, the radial energy distribution and ionisation cluster size distributions. These parametrisations of nanometric track structure build a basis for deriving biologically relevant mean values which are essential in the clinical situation where each voxel is exposed to a mixed radiation field. Contribution to the Topical Issue "COST Action Nano-IBCT: Nano-scale Processes Behind Ion-Beam Cancer Therapy", edited by Andrey Solov'yov, Nigel Mason, Gustavo García, Eugene Surdutovich.

  12. Energy-efficient boarder node medium access control protocol for wireless sensor networks.

    PubMed

    Razaque, Abdul; Elleithy, Khaled M

    2014-03-12

    This paper introduces the design, implementation, and performance analysis of the scalable and mobility-aware hybrid protocol named boarder node medium access control (BN-MAC) for wireless sensor networks (WSNs), which leverages the characteristics of scheduled and contention-based MAC protocols. Like contention-based MAC protocols, BN-MAC achieves high channel utilization, network adaptability under heavy traffic and mobility, and low latency and overhead. Like schedule-based MAC protocols, BN-MAC reduces idle listening time, emissions, and collision handling at low cost at one-hop neighbor nodes and achieves high channel utilization under heavy network loads. BN-MAC is particularly designed for region-wise WSNs. Each region is controlled by a boarder node (BN), which is of paramount importance. The BN coordinates with the remaining nodes within and beyond the region. Unlike other hybrid MAC protocols, BN-MAC incorporates three promising models that further reduce the energy consumption, idle listening time, overhearing, and congestion to improve the throughput and reduce the latency. One of the models used with BN-MAC is automatic active and sleep (AAS), which reduces the ideal listening time. When nodes finish their monitoring process, AAS lets them automatically go into the sleep state to avoid the idle listening state. Another model used in BN-MAC is the intelligent decision-making (IDM) model, which helps the nodes sense the nature of the environment. Based on the nature of the environment, the nodes decide whether to use the active or passive mode. This decision power of the nodes further reduces energy consumption because the nodes turn off the radio of the transceiver in the passive mode. The third model is the least-distance smart neighboring search (LDSNS), which determines the shortest efficient path to the one-hop neighbor and also provides cross-layering support to handle the mobility of the nodes. The BN-MAC also incorporates a semi

  13. Energy-Efficient Boarder Node Medium Access Control Protocol for Wireless Sensor Networks

    PubMed Central

    Razaque, Abdul; Elleithy, Khaled M.

    2014-01-01

    This paper introduces the design, implementation, and performance analysis of the scalable and mobility-aware hybrid protocol named boarder node medium access control (BN-MAC) for wireless sensor networks (WSNs), which leverages the characteristics of scheduled and contention-based MAC protocols. Like contention-based MAC protocols, BN-MAC achieves high channel utilization, network adaptability under heavy traffic and mobility, and low latency and overhead. Like schedule-based MAC protocols, BN-MAC reduces idle listening time, emissions, and collision handling at low cost at one-hop neighbor nodes and achieves high channel utilization under heavy network loads. BN-MAC is particularly designed for region-wise WSNs. Each region is controlled by a boarder node (BN), which is of paramount importance. The BN coordinates with the remaining nodes within and beyond the region. Unlike other hybrid MAC protocols, BN-MAC incorporates three promising models that further reduce the energy consumption, idle listening time, overhearing, and congestion to improve the throughput and reduce the latency. One of the models used with BN-MAC is automatic active and sleep (AAS), which reduces the ideal listening time. When nodes finish their monitoring process, AAS lets them automatically go into the sleep state to avoid the idle listening state. Another model used in BN-MAC is the intelligent decision-making (IDM) model, which helps the nodes sense the nature of the environment. Based on the nature of the environment, the nodes decide whether to use the active or passive mode. This decision power of the nodes further reduces energy consumption because the nodes turn off the radio of the transceiver in the passive mode. The third model is the least-distance smart neighboring search (LDSNS), which determines the shortest efficient path to the one-hop neighbor and also provides cross-layering support to handle the mobility of the nodes. The BN-MAC also incorporates a semi

  14. Properties of jets measured from tracks in proton-proton collisions at center-of-mass energy √s=7 TeV with the ATLAS detector

    DOE PAGES

    Aad, G.; Abbott, B.; Abdallah, J.; Abdelalim, A. A.; Abdesselam, A.; Abdinov, O.; Abi, B.; Abolins, M.; Abramowicz, H.; Abreu, H.; et al

    2011-09-20

    Jets are identified and their properties studied in center-of-mass energy √s=7 TeV proton-proton collisions at the Large Hadron Collider using charged particles measured by the ATLAS inner detector. Events are selected using a minimum bias trigger, allowing jets at very low transverse momentum to be observed and their characteristics in the transition to high-momentum fully perturbative jets to be studied. Jets are reconstructed using the anti-kt algorithm applied to charged particles with two radius parameter choices, 0.4 and 0.6. An inclusive charged jet transverse momentum cross section measurement from 4 GeV to 100 GeV is shown for four ranges inmore » rapidity extending to 1.9 and corrected to charged particle-level truth jets. The transverse momenta and longitudinal momentum fractions of charged particles within jets are measured, along with the charged particle multiplicity and the particle density as a function of radial distance from the jet axis. Comparison of the data with the theoretical models implemented in existing tunings of Monte Carlo event generators indicates reasonable overall agreement between data and Monte Carlo. These comparisons are sensitive to Monte Carlo parton showering, hadronization, and soft physics models.« less

  15. Effective particle energies for stopping power calculation in radiotherapy treatment planning with protons and helium, carbon, and oxygen ions

    NASA Astrophysics Data System (ADS)

    Inaniwa, T.; Kanematsu, N.

    2016-10-01

    The stopping power ratio (SPR) of body tissues relative to water depends on the particle energy. For simplicity, however, most analytical dose planning systems do not account for SPR variation with particle energy along the beam’s path, but rather assume a constant energy for SPR estimation. The range error due to this simplification could be indispensable depending on the particle species and the assumed energy. This error can be minimized by assuming a suitable energy referred to as an ‘effective energy’ in SPR estimation. To date, however, the effective energy has never been investigated for realistic patient geometries. We investigated the effective energies for proton, helium-, carbon-, and oxygen-ion radiotherapy using volumetric models of the reference male and female phantoms provided by the International Commission on Radiological Protection (ICRP). The range errors were estimated by comparing the particle ranges calculated when particle energy variations were and were not considered. The effective energies per nucleon for protons and helium, carbon, and oxygen ions were 70 MeV, 70 MeV, 131 MeV, and 156 MeV, respectively. Using the determined effective energies, the range errors were reduced to  ⩽0.3 mm for respective particle species. For SPR estimation of multiple particle species, an effective energy of 100 MeV is recommended, with which the range error is  ⩽0.5 mm for all particle species.

  16. Energy efficiency in the US economy technical report four: Analysis of energy-efficiency investment decisions by small and medium-sized manufacturers

    SciTech Connect

    1996-03-01

    This report highlights the results of a comprehensive analysis of investment decisions regarding energy-efficiency measures at small and medium-sized manufacturing plants. The analysis is based primarily on the experiences of companies participating in the US Department of Energy`s Industrial Assessment Center (IAC) program.

  17. Spectral Analyses and Radiation Exposures from Several Ground-Level Enhancement (GLE) Solar Proton Events: A Comparison of Methodologies

    NASA Technical Reports Server (NTRS)

    Atwell, William; Tylka, Allan; Dietrich, William; Badavi, Francis; Rojdev, Kristina

    2011-01-01

    Several methods for analyzing the particle spectra from extremely large solar proton events, called Ground-Level Enhancements (GLEs), have been developed and utilized by the scientific community to describe the solar proton energy spectra and have been further applied to ascertain the radiation exposures to humans and radio-sensitive systems, namely electronics. In this paper 12 GLEs dating back to 1956 are discussed, and the three methods for describing the solar proton energy spectra are reviewed. The three spectral fitting methodologies are EXP [an exponential in proton rigidity (R)], WEIB [Weibull fit: an exponential in proton energy], and the Band function (BAND) [a double power law in proton rigidity]. The EXP and WEIB methods use low energy (MeV) GLE solar proton data and make extrapolations out to approx.1 GeV. On the other hand, the BAND method utilizes low- and medium-energy satellite solar proton data combined with high-energy solar proton data deduced from high-latitude neutron monitoring stations. Thus, the BAND method completely describes the entire proton energy spectrum based on actual solar proton observations out to 10 GeV. Using the differential spectra produced from each of the 12 selected GLEs for each of the three methods, radiation exposures are presented and discussed in detail. These radiation exposures are then compared with the current 30-day and annual crew exposure limits and the radiation effects to electronics.

  18. Analytic expressions for the inelastic scattering and energy loss of electron and proton beams in carbon nanotubes

    SciTech Connect

    Emfietzoglou, D.; Kyriakou, I.; Garcia-Molina, R.; Abril, I.; Kostarelos, K.

    2010-09-15

    We have determined ''effective'' Bethe coefficients and the mean excitation energy of stopping theory (I-value) for multiwalled carbon nanotubes (MWCNTs) and single-walled carbon nanotube (SWCNT) bundles based on a sum-rule constrained optical-data model energy loss function with improved asymptotic properties. Noticeable differences between MWCNTs, SWCNT bundles, and the three allotropes of carbon (diamond, graphite, glassy carbon) are found. By means of Bethe's asymptotic approximation, the inelastic scattering cross section, the electronic stopping power, and the average energy transfer to target electrons in a single inelastic collision, are calculated analytically for a broad range of electron and proton beam energies using realistic excitation parameters.

  19. Medium energy elementary particle physics. Technical progress report, August 1, 1990--June 30, 1991

    SciTech Connect

    Not Available

    1991-12-31

    This report discusses the following topics: muon beam development at LAMPF; muon physics; a new precision measurement of the muon g-2 value; measurement of the spin-dependent structure functions of the neutron and proton; and meson factories. (LSP)

  20. Proton Therapy

    MedlinePlus

    ... nucleus is surrounded by electrons. In proton therapy, beams of fast-moving protons are used to destroy ... atoms to release proton, neutron, and helium ion beams. In this highly specialized form of radiosurgery , proton ...

  1. Proton-Proton and Proton-Antiproton Colliders

    NASA Astrophysics Data System (ADS)

    Scandale, Walter

    2015-02-01

    In the last five decades, proton-proton and proton-antiproton colliders have been the most powerful tools for high energy physics investigations. They have also deeply catalyzed innovation in accelerator physics and technology. Among the large number of proposed colliders, only four have really succeeded in becoming operational: the ISR, the SppbarS, the Tevatron and the LHC. Another hadron collider, RHIC, originally conceived for ion-ion collisions, has also been operated part-time with polarized protons. Although a vast literature documenting them is available, this paper is intended to provide a quick synthesis of their main features and key performance.

  2. Energy Spread of the Proton Beam in the Fermilab Booster at its Injection Energy

    SciTech Connect

    Bhat, C. M.; Chase, B. E.; Chaurize, S. J.; Garcia, F. G.; Seiya, K.; Pellico, W. A.; Sullivan, T. M.; Triplett, A. K.

    2015-04-27

    We have measured the energy spread of the Booster beam at its injection energy of 400 MeV by three different methods: (1) creating a notch of about 40 nsec wide in the beam immediately after multiple turn injection and measuring the slippage time required for high and low momentum particles for a grazing touch in line-charge distribution, (2) injecting partial turn beam and letting it to debunch, and (3) comparing the beam profile monitor data with predictions from MAD simulations for the 400 MeV injection beam line. The measurements are repeated under varieties of conditions of rf systems in the ring and in the beam transfer line.

  3. Energy spectra of protons, deuterium, and helium nuclei during quiet solar activity periods in 1996-97

    NASA Astrophysics Data System (ADS)

    Kecskemety, Karoly

    A background reduction method based on pulse-height analysis (see accompanying paper by Valtonen et al.) is applied for the data of the ERNE and EPHIN energetic particle telescopes aboard SOHO. Energy spectra of protons, deuterons, 3He and 4He nuclei have been obtained during very low activity periods in 1996-97 in the energy range of 1.3 to 22 MeV/n. The proton spectra are comparable to the lowest spectra of the Ulysses (COSPIN/LET, 1996) and near-Earth IMP-8 (1985-87) measurements. Deuterons and 3He are only significantly seen above about 10 MeV/n, their spectra are consistent with an increase proportional to kinetic energy, expected for purely galactic origin.

  4. 3d-shell contribution to the energy loss of protons during grazing scattering from Cu(111) surfaces

    SciTech Connect

    Gravielle, M. S.; Alducin, M.; Juaristi, J. I.; Silkin, V. M.

    2007-10-15

    Motivated by a recent experimental work [S. Lederer and H. Winter, Phys. Rev. A 73, 054901 (2006)] we study the contribution of the 3d shell electrons to the energy loss of 100 keV protons scattered off from the Cu(111) surface. To describe this process we use a multiple collision formalism, where the interaction of the projectile with 3d electrons is described by means of a sequence of single encounters with atoms belonging to the first atomic layer. In order to compare the theoretical energy loss with the experimental data, we add the contribution of valence electrons, which is evaluated in linear response theory using a response function that incorporates information on the surface band structure. For completeness, the energy lost by protons is also calculated within a jellium model that includes 3d and valence electrons with equal footing. Fair agreement between theory and experiment exists when the 3d shell is taken into account in the calculation.

  5. A medium-chain fatty acid as an alternative energy source in mouse preimplantation development.

    PubMed

    Yamada, Mitsutoshi; Takanashi, Kazumi; Hamatani, Toshio; Hirayama, Akiyoshi; Akutsu, Hidenori; Fukunaga, Tomoko; Ogawa, Seiji; Sugawara, Kana; Shinoda, Kosaku; Soga, Tomoyoshi; Umezawa, Akihiro; Kuji, Naoaki; Yoshimura, Yasunori; Tomita, Masaru

    2012-01-01

    To further optimize the culturing of preimplantation embryos, we undertook metabolomic analysis of relevant culture media using capillary electrophoresis time-of-flight mass spectrometry (CE-TOFMS). We detected 28 metabolites: 23 embryo-excreted metabolites including 16 amino acids and 5 media-derived metabolites (e.g., octanoate, a medium-chain fatty acid (MCFA)). Due to the lack of information on MCFAs in mammalian preimplantation development, this study examined octanoate as a potential alternative energy source for preimplantation embryo cultures. No embryos survived in culture media lacking FAs, pyruvate, and glucose, but supplementation of octanoate rescued the embryonic development. Immunoblotting showed significant expression of acyl-CoA dehydrogenase and hydroxyacyl-CoA dehydrogenase, important enzymes for ß-oxidation of MCFAs, in preimplantation embryo. Furthermore, CE-TOFMS traced [1-(13)C(8)] octanoate added to the culture media into intermediate metabolites of the TCA cycle via ß-oxidation in mitochondria. These results are the first demonstration that octanoate could provide an efficient alternative energy source throughout preimplantation development.

  6. Charge equilibrium and radiation of low-energy cosmic rays passing through interstellar medium

    NASA Technical Reports Server (NTRS)

    Rule, D. W.; Omidvar, K.

    1979-01-01

    The charge equilibrium and radiation of an oxygen and an iron beam in the MeV per nucleon energy range, representing a typical beam of low-energy cosmic rays passing through the interstellar medium, are considered. Electron loss of the beam has been taken into account by means of the first Born approximation, allowing for the target atom to remain unexcited or to be excited to all possible states. Electron-capture cross sections have been calculated by means of the scaled Oppenheimer-Brinkman-Kramers approximation, taking into account all atomic shells of the target atoms and capture into all excited states of the projectile. The capture and loss cross sections are found to be within 20%-30% of the existing experimental values for most of the cases considered. Radiation of the beam due to electron capture into the excited states of the ion, collisional excitation, and collisional inner-shell ionization, taking into account the fluorescence yield of the ions, has been considered. Effective X-ray production cross sections and multiplicities for the most energetic X-ray lines emitted by the Fe and O beams have been calculated, and error estimates made for the results.

  7. Silver sulphide growth on Ag(111): A medium energy ion scattering study

    NASA Astrophysics Data System (ADS)

    Window, A. J.; Hentz, A.; Sheppard, D. C.; Parkinson, G. S.; Woodruff, D. P.; Noakes, T. C. Q.; Bailey, P.

    2010-08-01

    The interaction of S 2 with Ag(111) under ultra-high vacuum conditions has been investigated by medium energy ion scattering (MEIS). 100 keV He + MEIS measurements provide a direct confirmation of a previous report, based on thermal desorption, that the growth of multilayer films of Ag 2S occurs through a continuous corrosion process. These films show a commensurate (√7 × √7)R19° unit mesh in low energy electron diffraction, consistent with the epitaxial growth of (111) layers of the high-temperature F-cubic phase of Ag 2S. The substantial range of co-existing film thicknesses found indicates that the growth must be in the form of variable-thickness islands. The use of 100 keV H + incident ions leads to a very rapid decrease in the sulphide film thickness with increasing exposure that we attribute to an unusual chemical leaching, with implanted H atoms interacting with S atoms and desorption of H 2S from the surface.

  8. Short- and medium-chain fatty acids in energy metabolism: the cellular perspective.

    PubMed

    Schönfeld, Peter; Wojtczak, Lech

    2016-06-01

    Short- and medium-chain fatty acids (SCFAs and MCFAs), independently of their cellular signaling functions, are important substrates of the energy metabolism and anabolic processes in mammals. SCFAs are mostly generated by colonic bacteria and are predominantly metabolized by enterocytes and liver, whereas MCFAs arise mostly from dietary triglycerides, among them milk and dairy products. A common feature of SCFAs and MCFAs is their carnitine-independent uptake and intramitochondrial activation to acyl-CoA thioesters. Contrary to long-chain fatty acids, the cellular metabolism of SCFAs and MCFAs depends to a lesser extent on fatty acid-binding proteins. SCFAs and MCFAs modulate tissue metabolism of carbohydrates and lipids, as manifested by a mostly inhibitory effect on glycolysis and stimulation of lipogenesis or gluconeogenesis. SCFAs and MCFAs exert no or only weak protonophoric and lytic activities in mitochondria and do not significantly impair the electron transport in the respiratory chain. SCFAs and MCFAs modulate mitochondrial energy production by two mechanisms: they provide reducing equivalents to the respiratory chain and partly decrease efficacy of oxidative ATP synthesis. PMID:27080715

  9. ELECTRON POLARIZATION IN THE MEDIUM-ENERGY ELECTRON-ION COLLIDER AT JLAB

    SciTech Connect

    Fanglei Lin, Yaroslav Derbenev, Vasiliy Morozov, Yuhong Zhang, Desmond Barber

    2012-07-01

    A key feature of the Medium-energy Electron-Ion Collider (MEIC) at Jefferson Lab is high polarization (over 80%) of the electron beam at all collision points for the particle physics program. The equilibrium electron polarization is arranged to be vertical in the arcs of the figure-8 collider ring of the MEIC and anti-parallel to the arc dipole magnetic fields, in order to take advantage of the preservation of polarization by the Sokolov-Ternov (S-T) effect. Longitudinal polarization is achieved at collision points by utilizing energy-independent universal spin rotators each of which consists of a set of solenoids and dipoles placed at the end of an arc. The equilibrium beam polarization and its lifetime depend on competition between the S-T effect and radiative depolarization. The latter must be suppressed by spin matching. This paper reports on investigations of polarization in the MEIC electron collider ring and a preliminary estimate of beam polarization from calculations using the code SLICK.

  10. A medium-chain fatty acid as an alternative energy source in mouse preimplantation development

    PubMed Central

    Yamada, Mitsutoshi; Takanashi, Kazumi; Hamatani, Toshio; Hirayama, Akiyoshi; Akutsu, Hidenori; Fukunaga, Tomoko; Ogawa, Seiji; Sugawara, Kana; Shinoda, Kosaku; Soga, Tomoyoshi; Umezawa, Akihiro; Kuji, Naoaki; Yoshimura, Yasunori; Tomita, Masaru

    2012-01-01

    To further optimize the culturing of preimplantation embryos, we undertook metabolomic analysis of relevant culture media using capillary electrophoresis time-of-flight mass spectrometry (CE-TOFMS). We detected 28 metabolites: 23 embryo-excreted metabolites including 16 amino acids and 5 media-derived metabolites (e.g., octanoate, a medium-chain fatty acid (MCFA)). Due to the lack of information on MCFAs in mammalian preimplantation development, this study examined octanoate as a potential alternative energy source for preimplantation embryo cultures. No embryos survived in culture media lacking FAs, pyruvate, and glucose, but supplementation of octanoate rescued the embryonic development. Immunoblotting showed significant expression of acyl-CoA dehydrogenase and hydroxyacyl-CoA dehydrogenase, important enzymes for ß-oxidation of MCFAs, in preimplantation embryo. Furthermore, CE-TOFMS traced [1-13C8] octanoate added to the culture media into intermediate metabolites of the TCA cycle via ß-oxidation in mitochondria. These results are the first demonstration that octanoate could provide an efficient alternative energy source throughout preimplantation development. PMID:23226596

  11. Alternating magnetic field energy absorption in the dispersion of iron oxide nanoparticles in a viscous medium

    NASA Astrophysics Data System (ADS)

    Smolkova, Ilona S.; Kazantseva, Natalia E.; Babayan, Vladimir; Smolka, Petr; Parmar, Harshida; Vilcakova, Jarmila; Schneeweiss, Oldrich; Pizurova, Nadezda

    2015-01-01

    Magnetic iron oxide nanoparticles were obtained by a coprecipitation method in a controlled growth process leading to the formation of uniform highly crystalline nanoparticles with average size of 13 nm, which corresponds to the superparamagnetic state. Nanoparticles obtained are a mixture of single-phase nanoparticles of magnetite and maghemite as well as nanoparticles of non-stoichiometric magnetite. The subsequent annealing of nanoparticles at 300 °C in air during 6 h leads to the full transformation to maghemite. It results in reduced value of the saturation magnetization (from 56 emu g-1 to 48 emu g-1) but does not affect the heating ability of nanoparticles. A 2-7 wt% dispersion of as-prepared and annealed nanoparticles in glycerol provides high heating rate in alternating magnetic fields allowed for application in magnetic hyperthermia; however the value of specific loss power does not exceed 30 W g-1. This feature of heat output is explained by the combined effect of magnetic interparticle interactions and the properties of the carrier medium. Nanoparticles coalesce during the synthesis and form aggregates showing ferromagnetic-like behavior with magnetization hysteresis, distinct sextets on Mössbauer spectrum, blocking temperature well about room temperature, which accounts for the higher energy barrier for magnetization reversal. At the same time, low specific heat capacity of glycerol intensifies heat transfer in the magnetic dispersion. However, high viscosity of glycerol limits the specific loss power value, since predominantly the Neel relaxation accounts for the absorption of AC magnetic field energy.

  12. Analysis of experimental data on neutron-proton scattering in the energy range between 0 and 150 keV

    NASA Astrophysics Data System (ADS)

    Babenko, V. A.; Petrov, N. M.

    2009-04-01

    Experimental data on neutron-proton scattering in the energy range between 0 and 150 keV are analyzed by using various sets of effective-range parameters. It is shown that, in contrast to the parameters corresponding to the phase shifts of a Nijmegen group, the parameters corresponding to the experimental phase shifts reported by a group from George Washington University (GWU group) lead to very good agreement between the calculated cross sections and their experimental counterparts in the energy region under consideration. On the basis of the experimental value of the cross section for neutron—proton scattering at an energy of 2 keV, the total cross section for neutron-proton scattering at zero energy was found to be σ 0 = 20.428(16) b, which is in very good agreement with a value of σ 0 = 20.423(9) b, which was obtained as the weighted mean of the cross sections presented by Houke and Hurst. It is shown that, in the energy region around several tens of keV units, the effective-range parameters matched with Dilg’s cross-section value of σ 0 = 20.491(14) b lead to calculated cross sections whose values are in excess of their experimental counterparts.

  13. Linear energy transfer dependence of a normoxic polymer gel dosimeter investigated using proton beam absorbed dose measurements

    NASA Astrophysics Data System (ADS)

    Gustavsson, Helen; Bäck, Sven Å. J.; Medin, Joakim; Grusell, Erik; Olsson, Lars E.

    2004-09-01

    Three-dimensional dosimetry with good spatial resolution can be performed using polymer gel dosimetry, which has been investigated for dosimetry of different types of particles. However, there are only sparse data concerning the influence of the linear energy transfer (LET) properties of the radiation on the gel absorbed dose response. The purpose of this study was to investigate possible LET dependence for a polymer gel dosimeter using proton beam absorbed dose measurements. Polymer gel containing the antioxidant tetrakis(hydroxymethyl)phosphonium (THP) was irradiated with 133 MeV monoenergetic protons, and the gel absorbed dose response was evaluated using MRI. The LET distribution for a monoenergetic proton beam was calculated as a function of depth using the Monte Carlo code PETRA. There was a steep increase in the Monte Carlo calculated LET starting at the depth corresponding to the front edge of the Bragg peak. This increase was closely followed by a decrease in the relative detector sensitivity (Srel = Dgel/Ddiode), indicating that the response of the polymer gel detector was dependent on LET. The relative sensitivity was 0.8 at the Bragg peak, and reached its minimum value at the end of the proton range. No significant effects in the detector response were observed for LET < 4.9 keV µm-1, thus indicating that the behaviour of the polymer gel dosimeter would not be altered for the range of LET values expected in the case of photons or electrons in a clinical range of energies.

  14. Technical Support Document: Development of the Advanced Energy Design Guide for Medium Box Retail -- 50% Energy Savings

    SciTech Connect

    Hale, E. T.; Macumber, D. L.; Long, N. L.; Griffith, B. T.; Benne, K. S.; Pless, S. D.; Torcellini, P. A.

    2008-09-01

    This report provides recommendations that architects, designers, contractors, developers, owners, and lessees of medium box retail buildings can use to achieve whole-building energy savings of at least 50% over ASHRAE Standard 90.1-2004. The recommendations are given by climate zone and address building envelope, fenestration, lighting systems, HVAC systems, building automation and controls, outside air treatment, service water heating, plug loads, and photovoltaic systems. The report presents several paths to 50% savings, which correspond to different levels of integrated design. These are recommendations only, and are not part of a code or standard. The recommendations are not exhaustive, but we do try to emphasize the benefits of integrated building design, that is, a design approach that analyzes a building as a whole system, rather than as a disconnected collection of individually engineered subsystems.

  15. Using high-energy proton fluence to improve risk prediction for consequences of solar particle events

    NASA Astrophysics Data System (ADS)

    Kim, Myung-Hee Y.; Hayat, Matthew J.; Feiveson, Alan H.; Cucinotta, Francis A.

    2009-12-01

    The potential for exposure to large solar particle events (SPEs) with high energy levels is a major concern during interplanetary transfer and extra-vehicular activities (EVAs) on the lunar and Mars surface. Previously, we have used data from the last 5 solar cycles to estimate percentiles of dose to a typical blood-forming organ (BFO) for a hypothetical astronaut in a nominally shielded spacecraft during a 120-d lunar mission. As part of this process, we made use of complete energy spectra for 34 large historical SPEs to calculate what the BFO mGy-Eq dose would have been in the above lunar scenario for each SPE. From these calculated doses, we then developed a prediction model for BFO dose based solely on an assumed value of integrated fluence above 30 MeV ( Φ30) for an otherwise unspecified future SPE. In this study, we reasoned that since BFO dose is determined more by protons with higher energies than by those with lower energies, more accurate BFO dose prediction models could be developed using integrated fluence above 60 ( Φ60) and above 100 MeV ( Φ100) as predictors instead of Φ30. However to calculate the unconditional probability of a BFO dose exceeding a pre-specified limit ("BFO dose risk"), one must also take into account the distribution of the predictor ( Φ30,Φ60, or Φ100), as estimated from historical SPEs. But Φ60 and Φ100 have more variability, and less available historical information on which to estimate their distributions over many SPE occurrences, than does Φ30. Therefore, when estimating BFO dose risk there is a tradeoff between increased BFO dose prediction at a given energy threshold and decreased accuracy of models for describing the distribution of that threshold over future SPEs as the threshold increases. Even when taking the second of these two factors into account, we still arrived at the conclusion that overall prediction improves as the energy level threshold increases from 30 to 60 to 100 MeV. These results can be applied

  16. Application of the discrete generalized multigroup method to ultra-fine energy mesh in infinite medium calculations

    SciTech Connect

    Gibson, N. A.; Forget, B.

    2012-07-01

    The Discrete Generalized Multigroup (DGM) method uses discrete Legendre orthogonal polynomials to expand the energy dependence of the multigroup neutron transport equation. This allows a solution on a fine energy mesh to be approximated for a cost comparable to a solution on a coarse energy mesh. The DGM method is applied to an ultra-fine energy mesh (14,767 groups) to avoid using self-shielding methodologies without introducing the cost usually associated with such energy discretization. Results show DGM to converge to the reference ultra-fine solution after a small number of recondensation steps for multiple infinite medium compositions. (authors)

  17. On the Energy Spectrum of Protons Produced in {sup 16}Op Collisions at a Momentum of 3.25 GeV/c per Nucleon

    SciTech Connect

    Bazarov, E.Kh.

    2005-09-01

    New experimental data concerning the mechanisms of the production of protons originating as fragments from oxygen-nucleus interactions in a hydrogen bubble chamber at high energies are presented. It is shown that anomalies observed in the energy spectrum of protons at kinetic energies in the range T = 70 - 90 MeV are associated with the absorption of slow pions by a quasideuteron nucleon pair.

  18. The Advanced Energetic Pair Telescope (AdEPT}: A Future Medium-Energy Gamma-Ray Balloon (and Explorer?) Mission

    NASA Technical Reports Server (NTRS)

    Hunter, Stanley D.

    2011-01-01

    Gamma-ray astrophysics probes the highest energy, exotic phenomena in astrophysics. In the medium-energy regime, 0.1-200 MeV, many astrophysical objects exhibit unique and transitory behavior such as the transition from electron dominated to hadron dominated processes, spectral breaks, bursts, and flares. Medium-energy gamma-ray imaging however, continues to be a major challenge particularly because of high background, low effective area, and low source intensities. The sensitivity and angular resolution required to address these challenges requires a leap in technology. The Advance Energetic Pair Telescope (AdEPT) being developed at GSFC is designed to image gamma rays above 5 MeV via pair production with angular resolution of 1-10 deg. In addition AdEPT will, for the first time, provide high polarization sensitivity in this energy range. This performance is achieved by reducing the effective area in favor of enhanced angular resolution through the use of a low-density gaseous conversion medium. AdEPT is based on the Three-Dimensional Track Imager (3-DTI) technology that combines a large volume Negative Ion Time Projection Chamber (NITPC) with 2-D Micro-Well Detector (MWD) readout. I will review the major science topics addressable with medium-energy gamma-rays and discuss the current status of the AdEPT technology, a proposed balloon instrument, and the design of a future satellite mission.

  19. Record Deflection Efficiencies Measured for High Energy Protons in a Bent Germanium Crystal

    NASA Astrophysics Data System (ADS)

    Elsener, K.; Biino, C.; Clement, M.; Doble, N.; Gatignon, L.; Grafstrom, P.; Mikkelsen, U.; Kirsebom, K.; Møller, S. P.; Uggerhøj, E.; Worm, T.; Freund, A.

    1997-05-01

    New experimental results on the deflection of 450 GeV/c and 200 GeV/c protons in a bent Ge crystal are presented. At 450 GeV/c, the 50 mm long crystal gave record deflection efficiencies up to 60% for small angles (1 mrad), while at angles as large as 12 mrad, the efficiency is about 25 times larger than for a silicon crystal of the same size. Measurements up to 20 mrad deflection angle have been performed at 200 GeV/c as well as 450 GeV/c - the lower bending dechanneling leads to a rather slow decrease in efficiency at lower momenta, and 15% of the 200 GeV/c beam hitting the crystal are still deflected at the largest angles measured. These experimental results are in good agreement with a model for channeling deflection developed by Ellison and give confidence in extrapolations to higher energies (e.g. to LHC), other crystal materials or different deflection angles.

  20. On the mean kinetic energy of the proton in strong hydrogen bonded systems.

    PubMed

    Finkelstein, Y; Moreh, R; Shang, S L; Shchur, Ya; Wang, Y; Liu, Z K

    2016-02-01

    The mean atomic kinetic energies of the proton, Ke(H), and of the deuteron, Ke(D), were calculated in moderate and strongly hydrogen bonded (HB) systems, such as the ferro-electric crystals of the KDP type (XH2PO4, X = K, Cs, Rb, Tl), the DKDP (XD2PO4, X = K, Cs, Rb) type, and the X3H(SO4)2 superprotonic conductors (X = K, Rb). All calculations utilized the simulated partial phonon density of states, deduced from density functional theory based first-principle calculations and from empirical lattice dynamics simulations in which the Coulomb, short range, covalent, and van der Waals interactions were accounted for. The presently calculated Ke(H) values for the two systems were found to be in excellent agreement with published values obtained by deep inelastic neutron scattering measurements carried out using the VESUVIO instrument of the Rutherford Laboratory, UK. The Ke(H) values of the M3H(SO4)2 compounds, in which the hydrogen bonds are centro-symmetric, are much lower than those of the KDP type crystals, in direct consistency with the oxygen-oxygen distance ROO, being a measure of the HB strength. PMID:26851916

  1. Oxide-ion and proton conducting electrolyte materials for clean energy applications: structural and mechanistic features.

    PubMed

    Malavasi, Lorenzo; Fisher, Craig A J; Islam, M Saiful

    2010-11-01

    This critical review presents an overview of the various classes of oxide materials exhibiting fast oxide-ion or proton conductivity for use as solid electrolytes in clean energy applications such as solid oxide fuel cells. Emphasis is placed on the relationship between structural and mechanistic features of the crystalline materials and their ion conduction properties. After describing well-established classes such as fluorite- and perovskite-based oxides, new materials and structure-types are presented. These include a variety of molybdate, gallate, apatite silicate/germanate and niobate systems, many of which contain flexible structural networks, and exhibit different defect properties and transport mechanisms to the conventional materials. It is concluded that the rich chemistry of these important systems provides diverse possibilities for developing superior ionic conductors for use as solid electrolytes in fuel cells and related applications. In most cases, a greater atomic-level understanding of the structures, defects and conduction mechanisms is achieved through a combination of experimental and computational techniques (217 references). PMID:20848015

  2. Oxide-ion and proton conducting electrolyte materials for clean energy applications: structural and mechanistic features.

    PubMed

    Malavasi, Lorenzo; Fisher, Craig A J; Islam, M Saiful

    2010-11-01

    This critical review presents an overview of the various classes of oxide materials exhibiting fast oxide-ion or proton conductivity for use as solid electrolytes in clean energy applications such as solid oxide fuel cells. Emphasis is placed on the relationship between structural and mechanistic features of the crystalline materials and their ion conduction properties. After describing well-established classes such as fluorite- and perovskite-based oxides, new materials and structure-types are presented. These include a variety of molybdate, gallate, apatite silicate/germanate and niobate systems, many of which contain flexible structural networks, and exhibit different defect properties and transport mechanisms to the conventional materials. It is concluded that the rich chemistry of these important systems provides diverse possibilities for developing superior ionic conductors for use as solid electrolytes in fuel cells and related applications. In most cases, a greater atomic-level understanding of the structures, defects and conduction mechanisms is achieved through a combination of experimental and computational techniques (217 references).

  3. The use of low energy, ion induced nuclear reactions for proton radiotherapy applications

    SciTech Connect

    Horn, K.M.; Doyle, B.; Segal, M.N.; Hamm, R.W.; Adler, R.J.; Glatstein, E.

    1995-04-01

    Medical radiotherapy has traditionally relied upon the use of external photon beams and internally implanted radioisotopes as the chief means of irradiating tumors. However, advances in accelerator technology and the exploitation of novel means of producing radiation may provide useful alternatives to some current modes of medical radiation delivery with reduced total dose to surrounding healthy tissue, reduced expense, or increased treatment accessibility. This paper will briefly overview currently established modes of radiation therapy, techniques still considered experimental but in clinical use, innovative concepts under study that may enable new forms of treatment or enhance existing ones. The potential role of low energy, ion-induced nuclear reactions in radiotherapy applications is examined specifically for the 650 keV d({sup 3}He,p){sup 4}He nuclear reaction. This examination will describe the basic physics associated with this reaction`s production of 17.4 MeV protons and the processes used to fabricate the necessary materials used in the technique. Calculations of the delivered radiation dose, heat generation, and required exposure times are presented. Experimental data are also presented validating the dose calculations. The design of small, lower cost ion accelerators, as embodied in `nested`-tandem and radio frequency quadrupole accelerators is examined, as is the potential use of high-output {sup 3}He and deuterium ion sources. Finally, potential clinical applications are discussed in terms of the advantages and disadvantages of this technique with respect to current radiotherapy methods and equipment.

  4. SCC-DFTB Energy Barriers for Single and Double Proton Transfer Processes in the Model Molecular Systems Malonaldehyde and Porphycene

    SciTech Connect

    Walewski, L.; Krachtus, D; Fischer, S.; Smith, Jeremy C; Bala, P.; Lesyng, B.

    2005-09-01

    Self-consistent charge-density functional tight-binding SCC-DFTB is a computationally efficient method applicable to large (bio)molecular systems in which (bio)chemical reactions may occur. Among these reactions are proton transfer processes. This method, along with more advanced ab initio techniques, is applied in this study to compute intramolecular barriers for single and double proton transfer processes in the model systems, malonaldehyde and porphycene, respectively. SCC-DFTB is compared with experimental data and higher-level ab initio calculations. For malonaldehyde, the SCC-DFTB barrier height is 3.1 kcal/mol in vacuo and 4.2 kcal/mol in water solution. In the case of porphycene, the minimum energy pathways for double intramolecular proton transfer were determined using the conjugate peak refinement (CPR) method. Six isomers of porphycene were ordered according to energy. The only energetically allowed pathway was found to connect two symmetrical trans states via an unstable cis-A isomer. The SCC-DFTB barrier heights are 11.1 kcal/mol for the trans-cis-A process, and 7.4 kcal/mol for the reverse cis-A-trans one with the energy difference of 3.7 kcal/mol between the trans- and cis-A states. The method provides satisfactory energy results when compared with reference ab initio and experimental data.

  5. Proton therapy monitoring by Compton imaging: influence of the large energy spectrum of the prompt-γ radiation

    NASA Astrophysics Data System (ADS)

    Hilaire, Estelle; Sarrut, David; Peyrin, Françoise; Maxim, Voichiţa

    2016-04-01

    In proton therapy, the prompt-γ (PG) radiation produced by the interactions between protons and matter is related to the range of the beam in the patient. Tomographic Compton imaging is currently studied to establish a PG image and verify the treatment. However the quality of the reconstructed images depends on a number of factors such as the volume attenuation, the spatial and energy resolutions of the detectors, incomplete absorptions of high energy photons and noise from other particles reaching the camera. The impact of all these factors was not assessed in details. In this paper we investigate the influence of the PG energy spectrum on the reconstructed images. To this aim, we describe the process from the Monte Carlo simulation of the proton irradiation, through the Compton imaging of the PG distribution, up to the image reconstruction with a statistical MLEM method. We identify specific PG energy windows that are more relevant to detect discrepancies with the treatment plan. We find that for the simulated Compton device, the incomplete absorption of the photons with energy above about 2 MeV prevents the observation of the PG distributions at specific energies. It also leads to blurred images and smooths the distal slope of the 1D PG profiles obtained as projections on the central beam axis. We show that a selection of the events produced by γ photons having deposited almost all their energy in the camera allows to largely improve the images, a result that emphasizes the importance of the choice of the detector. However, this initial-energy-based selection is not accessible in practice. We then propose a method to estimate the range of the PG profile both for specific deposited-energy windows and for the full spectrum emission. The method relies on two parameters. We use a learning approach for their estimation and we show that it allows to detect few millimeter shifts of the PG profiles.

  6. Evaluation of the dosimetric properties of a synthetic single crystal diamond detector in high energy clinical proton beams

    SciTech Connect

    Mandapaka, A. K.; Ghebremedhin, A.; Patyal, B.; Marinelli, Marco; Prestopino, G.; Verona, C.; Verona-Rinati, G.

    2013-12-15

    Purpose: To investigate the dosimetric properties of a synthetic single crystal diamond Schottky diode for accurate relative dose measurements in large and small field high-energy clinical proton beams.Methods: The dosimetric properties of a synthetic single crystal diamond detector were assessed by comparison with a reference Markus parallel plate ionization chamber, an Exradin A16 microionization chamber, and Exradin T1a ion chamber. The diamond detector was operated at zero bias voltage at all times. Comparative dose distribution measurements were performed by means of Fractional depth dose curves and lateral beam profiles in clinical proton beams of energies 155 and 250 MeV for a 14 cm square cerrobend aperture and 126 MeV for 3, 2, and 1 cm diameter circular brass collimators. ICRU Report No. 78 recommended beam parameters were used to compare fractional depth dose curves and beam profiles obtained using the diamond detector and the reference ionization chamber. Warm-up/stability of the detector response and linearity with dose were evaluated in a 250 MeV proton beam and dose rate dependence was evaluated in a 126 MeV proton beam. Stem effect and the azimuthal angle dependence of the diode response were also evaluated.Results: A maximum deviation in diamond detector signal from the average reading of less than 0.5% was found during the warm-up irradiation procedure. The detector response showed a good linear behavior as a function of dose with observed deviations below 0.5% over a dose range from 50 to 500 cGy. The detector response was dose rate independent, with deviations below 0.5% in the investigated dose rates ranging from 85 to 300 cGy/min. Stem effect and azimuthal angle dependence of the diode signal were within 0.5%. Fractional depth dose curves and lateral beam profiles obtained with the diamond detector were in good agreement with those measured using reference dosimeters.Conclusions: The observed dosimetric properties of the synthetic single

  7. Biological effectiveness of nuclear fragments produced by high-energy protons interacting in tissues near the bone- soft tissue interface

    NASA Astrophysics Data System (ADS)

    Shavers, Mark Randall

    1999-12-01

    High-energy protons in the galactic cosmic rays (GCR)-or generated by nuclear interactions of GCR heavy-ions with material-are capable of penetrating great thicknesses of shielding to irradiate humans in spacecraft or in lunar or Martian habitats. As protons interact with the nuclei of the elemental constituents of soft tissue and bone, low energy nuclei-target fragments-are emitted into the cells responsible for bone development and maintenance and for hematopoiesis. Leukemogenesis is the principal endpoint of concern because it is the most likely deleterious effect, and it has a short latency period and comparatively low survival rate, although other myelo- proliferative disorders and osteosarcoma also may be induced. A one-dimensional proton-target fragment transport model was used to calculate the energy spectra of fragments produced in bone and soft tissue, and present in marrow cavities at distances from a bone interface. In terms of dose equivalent, the target fragments are as significant as the incident protons. An average radiation quality factor was found to be between 1.8 and 2.6. Biological response to the highly non- uniform energy deposition of the target fragments is such that an alternative approach to conventional predictive risk assessment is needed. Alternative procedures are presented. In vitro cell response and relative biological effectiveness were calculated from the radial dose distribution of each fragment produced by 1-GeV protons using parameters of a modified Ion-Gamma- Kill (IGK) model of radiation action. The modelled endpoints were survival of C3H10t 1/2 and V79 cells, neoplastic transformation of C3H10t1/2 cells, and mutation of the X-linked hypoxanthine phosphoribosyltransferase (HPRT) locus in V79 cells. The dose equivalent and cell responses increased by 10% or less near the interface. Since RBE increases with decreasing dose in the IGK model, comparisons with quality factors were made at dose levels 0.01 <= D [Gy] <= 2. Applying

  8. A Simpler Energy Transfer Efficiency Model to Predict Relative Biological Effect for Protons and Heavier Ions

    PubMed Central

    Jones, Bleddyn

    2015-01-01

    The aim of this work is to predict relative biological effectiveness (RBE) for protons and clinically relevant heavier ions, by using a simplified semi-empirical process based on rational expectations and published experimental results using different ion species. The model input parameters are: Z (effective nuclear charge) and radiosensitivity parameters αL and βL of the control low linear energy transfer (LET) radiation. Sequential saturation processes are assumed for: (a) the position of the turnover point (LETU) for the LET–RBE relationship with Z, and (b) the ultimate value of α at this point (αU) being non-linearly related to αL. Using the same procedure for β, on the logical assumption that the changes in β with LET, although smaller than α, are symmetrical with those of α, since there is symmetry of the fall off of LET–RBE curves with increasing dose, which suggests that LETU must be identical for α and β. Then, using iso-effective linear quadratic model equations, the estimated RBE is scaled between αU and αL and between βU and βL from for any input value of Z, αL, βL, and dose. The model described is fitted to the data of Barendsen (alpha particles), Weyrather et al. (carbon ions), and Todd for nine different ions (deuterons to Argon), which include variations in cell surviving fraction and dose. In principle, this new system can be used to complement the more complex methods to predict RBE with LET such as the local effect and MKM models which already have been incorporated into treatment planning systems in various countries. It would be useful to have a secondary check to such systems, especially to alert clinicians of potential risks by relatively easy estimation of relevant RBEs. In clinical practice, LET values smaller than LETU are mostly encountered, but the model extends to higher values beyond LETU for other purposes such as radiation, protection, and astrobiology. Considerable further research is required, perhaps in a

  9. Possible production of high-energy gamma rays from proton acceleration in the extragalactic radio source markarian 501

    PubMed

    Mannheim

    1998-01-30

    The active galaxy Markarian 501 was discovered with air-Cerenkov telescopes at photon energies of 10 tera-electron volts. Such high energies may indicate that the gamma rays from Markarian 501 are due to the acceleration of protons rather than electrons. Furthermore, the observed absence of gamma ray attenuation due to electron-positron pair production in collisions with cosmic infrared photons implies a limit of 2 to 4 nanowatts per square meter per steradian for the energy flux of an extragalactic infrared radiation background at a wavelength of 25 micrometers. This limit provides important clues about the epoch of galaxy formation.

  10. Computed Pion Yields from a Tantalum Rod Target: Comparing MARS15 and GEANT4 Across Proton Energies

    NASA Astrophysics Data System (ADS)

    Brooks, S. J.; Walaron, K. A.

    2006-05-01

    The choice of proton driver energy is an important variable in maximising the pion flux available in later stages of the neutrino factory. Simulations of pion production using a range of energies are presented and cross-checked for reliability between the codes MARS15 and GEANT4. The distributions are combined with postulated apertures for the pion decay channel and muon front-end to estimate the usable muon flux after capture losses. Resolution of discrepancies between the codes awaits experimental data in the required energy range.

  11. Elastic proton-proton scattering at RHIC

    SciTech Connect

    Yip, K.

    2011-09-03

    Here we describe elastic proton+proton (p+p) scattering measurements at RHIC in p+p collisions with a special optics run of {beta}* {approx} 21 m at STAR, at the center-of-mass energy {radical}s = 200 GeV during the last week of the RHIC 2009 run. We present preliminary results of single and double spin asymmetries.

  12. Analytical linear energy transfer model including secondary particles: calculations along the central axis of the proton pencil beam

    NASA Astrophysics Data System (ADS)

    Marsolat, F.; De Marzi, L.; Pouzoulet, F.; Mazal, A.

    2016-01-01

    In proton therapy, the relative biological effectiveness (RBE) depends on various types of parameters such as linear energy transfer (LET). An analytical model for LET calculation exists (Wilkens’ model), but secondary particles are not included in this model. In the present study, we propose a correction factor, L sec, for Wilkens’ model in order to take into account the LET contributions of certain secondary particles. This study includes secondary protons and deuterons, since the effects of these two types of particles can be described by the same RBE-LET relationship. L sec was evaluated by Monte Carlo (MC) simulations using the GATE/GEANT4 platform and was defined by the ratio of the LET d distributions of all protons and deuterons and only primary protons. This method was applied to the innovative Pencil Beam Scanning (PBS) delivery systems and L sec was evaluated along the beam axis. This correction factor indicates the high contribution of secondary particles in the entrance region, with L sec values higher than 1.6 for a 220 MeV clinical pencil beam. MC simulations showed the impact of pencil beam parameters, such as me