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Sample records for incident particle energy

  1. Alpha-particle breakup at incident energies of 20 and 40 MeV/nucleon

    International Nuclear Information System (INIS)

    Wu, J.R.; Chang, C.C.; Holmgren, H.D.; Koontz, R.W.

    1979-01-01

    The breakup of alpha particles at incident energies of 20 and 40 MeV/nucleon on 27 Al, 58 Ni, 90 Zr, and 209 Bi has been studied. It was found that the breakup cross section decreases rapidly with increasing angles and increases with increasing target mass and incident energy. The total breakup yield, summed over all charged fragments, is approx.15--35% of the alpha-particle total reaction cross section, and has an approximate A/sup 1/3/ dependence. The ratios of breakup yields among different fragments are approximately p:d:t: 3 He approx. = 13:3:1:2, and are roughly independent of the incident energy and the target nucleus. These features suggest that the alpha-particle fragmentation is a peripheral process and is dominated by the properties of the incident projectile. A simple plane-wave alpha-particle breakup model gives a rather good description to the experimental data. In addition to the breakup deuteron peak at half of the beam energy, a second peak at quarter of the beam energy (or the same energy as the breakup proton peak) is observed. This peak might be due to a two-step breakup-pickup process

  2. Preliminary proposals for extending the ENDF format to allow incident charged particles and energy-angle correlation for emitted particles

    International Nuclear Information System (INIS)

    MacFarlane, R.E.; Stewart, L.; Hale, G.M.; Dunford, C.L.

    1984-04-01

    This rewrite of Data Formats and Procedures for the Evaluated Nuclear Data File, ENDF pertains to the latest version, ENDF/B-VI. Earlier versions provided representations for neutron cross sections and distributions, photon production from neutron reactions, a limited amount of charged-particle production from neutron reactions, photo-atomic interaction data, thermal neutron scattering data, and radionuclide production and decay data (including fission products). This version allows higher incident energies, adds more complete descriptions of the distributions of emitted particles, and provides for incident charged particles and photo-nuclear data by partitioning the ENDF library into sublibraries. Decay data, fission product yield data, thermal scattering data, and photo-atomic data have also been formally placed in sublibraries. In addition, this rewrite represents an extensive update to the Version V manual

  3. Activation energy of etching for CR-39 as a function of linear energy transfer of the incident particles

    CERN Document Server

    Awad, E M

    1999-01-01

    In this work, we have studied the effect of the radiation damage caused by the incident particles on the activation energy of etching for CR-39 samples. The damage produced by the incident particle is expressed in terms of the linear energy transfer (LET). CR-39 samples from American Acrylic were irradiated to three different LET particles. These are N (LET sub 2 sub 0 sub 0 = 20 KeV/mu m) as a light particle, Fe (LET sub 2 sub 0 sub 0 = 110 KeV/mu m) as a medium particle and fission fragments (ff) from a sup 2 sup 5 sup 2 Cf source as heavy particles. In general the bulk etch rate was calculated using the weight difference method and the track etch rate was determined using the track geometry at various temperatures (50-90 deg. C) and concentrations (4-9 N) of the NaOH etchant. The average activation energy E sub b related to the bulk etch rate v sub b was calculated from 1n v sub b vs. 1/T. The average activation energy E sub t related to the track etch rate v sub t was estimated from 1n v sub t vs. 1/T. It...

  4. Energy dependence of angular distributions of sputtered particles by ion-beam bombardment at normal incidence

    International Nuclear Information System (INIS)

    Matsuda, Yoshinobu; Ueda, Yasutoshi; Uchino, Kiichiro; Muraoka, Katsunori; Maeda, Mitsuo; Akazaki, Masanori; Yamamura, Yasunori.

    1986-01-01

    The angular distributions of sputtered Fe-atoms were measured using the laser fluorescence technique during Ar-ion bombardment for energies of 0.6, 1, 2 and 3 keV at normal incidence. The measured cosine distribution at 0.6 keV progressively deviated to an over-cosine distribution at higher energies, and at 3 keV the angular distribution was an overcosine distribution of about 20 %. The experimental results agree qualitatively with calculations by a recent computer simulation code, ACAT. The results are explained by the competition between surface scattering and the effects of primary knock-on atoms, which tend to make the angular distributions over-cosine and under-cosine, respectively. (author)

  5. Calculations on precompound reactions with alpha particles, A(α,α')X, at incident energies around 500 MeV

    International Nuclear Information System (INIS)

    Rittershausen, W.

    1987-01-01

    The model of Chiang et al. (1980) for nucleon induced precompound reactions, a generalization of the Glauber theory to lower energetical processes, was extended to heavier projectiles the elementary differential cross section of which may furthermore (at fixed incident energy) depend on the momentum transfer. The so modified model was applied to reactions of the type A(α,α')X at an incident energy of about 100 MeV/nucleon, excitation energies of the nucleus in the range 6 to 60 MeV, and for scattering angles from 3 to 6 0 . Thereby the Glauber coefficients were determined by means of the optical potentials known for the treated experiments. Local nucleon momentum distributions in the target nucleus were taken from calculations of Durand et al. (1982). The momentum distributions of the alpha particles after the first α-N collision were both for normalously and for homogeneously distributed nucleon momenta calculated analytically. The distributions after the second collision were determined by folding. For the control of these results and for the eventual calculation of the distributions after more than two collisions a Monte Carlo routine was written. The additional deviation of the alpha particles in real-valued potentials of the target nucleus were regarded. The results in which no free parameter occurs agree quite well in the shape with measured data. In one case it is also valid for the absolute quantities. (orig.) [de

  6. Influence of the incident particle energy on the fission product mass distribution

    International Nuclear Information System (INIS)

    Gomes, I. C.

    1998-01-01

    For 238 U targets and the five elements considered here, the best yields of neutron-rich isotopes are obtained from neutrons in the 2-20 MeV range. High energy beams of neutrons, protons, and deuterons have comparable integral yields per element to neutrons below 20 MeV, but the distributions are peaked at lower neutron numbers. This is presumably due to a higher neutron multiplicity in the pre-equilibrium stage and/or the compound nucleus/fission stage. For 235 U targets there are high yields predicted especially for thermal neutrons, and also for the fast neutron spectrum. For the high energy neutrons, protons, and deuterons 235 U has no advantage over 238 U. A detailed comparison of the relative advantages of 235 U and 238 U for radioactive beam applications is beyond the scope of this study and will be addressed in the future. The present work is the first step of a more detailed analysis of various possible one- and two-step target geometry calculated with the LAHET code system. It is intended to serve as a guide in choosing geometry and beams for future studies. It is desirable to extend this study to higher beam energies, e.g. 200 to 1000 MeV, but at this time there is very little data against which to benchmark the analysis. Additional data would also permit comparisons of isotope yields beyond the tails of the distributions presented here, to even more neutron rich isotopes

  7. Pseudorapidity distributions of charged particles as a function of centrality in Pb-Pb collisions at 158 and 40 GeV per nucleon incident energy

    CERN Document Server

    Abreu, M C; Alexa, C; Arnaldi, R; Ataian, M R; Baglin, C; Baldit, A; Bedjidian, Marc; Beolè, S; Boldea, V; Bordalo, P; Borges, G; Bussière, A; Capelli, L; Castanier, C; Castor, J I; Chaurand, B; Chevrot, I; Cheynis, B; Chiavassa, E; Cicalò, C; Claudino, T; Comets, M P; Constans, N; Constantinescu, S; Cortese, P; De Falco, A; De Marco, N; Dellacasa, G; Devaux, A; Dita, S; Drapier, O; Ducroux, L; Espagnon, B; Fargeix, J; Force, P; Gallio, M; Gavrilov, Yu K; Gerschel, C; Giubellino, P; Golubeva, M B; Gonin, M; Grigorian, A A; Grigorian, S; Grossiord, J Y; Guber, F F; Guichard, A; Gulkanian, H R; Hakobyan, R S; Haroutunian, R; Idzik, M; Jouan, D; Karavitcheva, T L; Kluberg, L; Kurepin, A B; Le Bornec, Y; Lourenço, C; Macciotta, P; MacCormick, M; Marzari-Chiesa, A; Masera, M; Masoni, A; Monteno, M; Musso, A; Petiau, P; Piccotti, A; Pizzi, J R; Prado da Silva, W L; Prino, F; Puddu, G; Quintans, C; Ramello, L; Ramos, S; Rato-Mendes, P; Riccati, L; Romana, A; Santos, H; Saturnini, P; Scalas, E; Scomparin, E; Serci, S; Shahoyan, R; Sigaudo, F; Silva, S; Sitta, M; Sonderegger, P; Tarrago, X; Topilskaya, N S; Usai, G L; Vercellin, Ermanno; Villatte, L; Willis, N

    2002-01-01

    The charged particle distributions $dN_{ch}/d\\eta$ have been measured by the NA50 experiment in Pb--Pb collisions at the CERN SPS. Measurements have been done at incident energies of 158 and 40 GeV per nucleon over a broad impact parameter range. Results obtained with two independent centrality estimators, namely the neutral transverse energy $E_T$ and the forward energy $E_{ZDC}$, are reported.}

  8. Experimental cross sections for light-charged particle production induced by neutrons with energies between 25 and 65 MeV incident on aluminum

    International Nuclear Information System (INIS)

    Benck, S.; Slypen, I.; Meulders, J.P.; Corcalciuc, V.

    2001-01-01

    Experimental double-differential cross sections (d 2 σ/dΩdE) for fast neutron-induced proton, deuteron, triton, and alpha-particle production on aluminum are reported, at several incident neutron energies between 25 and 65 MeV, for outgoing particle energies above the experimental energy thresholds. Angular distributions were measured at laboratory angles between 20 deg. and 160 deg. . Reliable extrapolated spectra are derived for very forward (2.5 deg. and 10 deg. ) and very backward angles (170 deg. and 177.5 deg. ). Based on these experimental data, energy-differential (dσ/dE), angle-differential (dσ/dΩ), and total production cross sections (σ T ) are reported for each outgoing particle

  9. Integral particle reflection coefficient for oblique incidence of photons as universal function in the domain of initial energies up to 300 keV

    Directory of Open Access Journals (Sweden)

    Ljubenov Vladan L.

    2014-01-01

    Full Text Available In this paper we present the results of calculations and analyses of the integral particle reflection coefficient of photons for oblique photon incidence on planar targets, in the domain of initial photon energies from 100 keV to 300 keV. The results are based on the Monte Carlo simulations of the photon reflection from water, concrete, aluminum, iron, and copper materials, performed by the MCNP code. It has been observed that the integral particle reflection coefficient as a function of the ratio of total cross-section of photons and effective atomic number of target material shows universal behavior for all the analyzed shielding materials in the selected energy domain. Analytical formulas for different angles of photon incidence have been proposed, which describe the reflection of photons for all the materials and energies analyzed.

  10. Measurement of double differential cross sections of charged particle emission reactions by incident DT neutrons. Correction for energy loss of charged particle in sample materials

    International Nuclear Information System (INIS)

    Takagi, Hiroyuki; Terada, Yasuaki; Murata, Isao; Takahashi, Akito

    2000-01-01

    In the measurement of charged particle emission spectrum induced by neutrons, correcting the energy loss of charged particle in sample materials becomes a very important inverse problem. To deal with this inverse problem, we have applied the Bayesian unfolding method to correct the energy loss, and tested the performance of the method. Although this method is very simple, it was confirmed from the test that the performance was not inferior to other methods at all, and therefore the method could be a powerful tool for charged particle spectrum measurement. (author)

  11. Energy-loss straggling study of proton and alpha-particle beams incident onto ZrO{sub 2} and Al{sub 2}O{sub 3}

    Energy Technology Data Exchange (ETDEWEB)

    Behar, M.; Fadanelli, R.C. [Instituto de Fisica, Universidade Federal do Rio Grande do Sul, Porto Alegre, 91501-970 (Brazil); Abril, I. [Departamento de Fisica Aplicada, Universitat d' Alacant, 03080 Alacant (Spain); Garcia-Molina, R. [Departamento de Fisica, Centro de Investigacion en Optica y Nanofisica, Universidad de Murcia, 30100 Murcia (Spain); Nagamine, L.C.C. [Instituto de Fisica, Universidade de Sao Paulo, C.P.66318, 05315-970 Sao Paulo (Brazil)

    2011-10-15

    The energy-loss straggling of zirconia (ZrO{sub 2}) and alumina (Al{sub 2}O{sub 3}) has been experimentally determined for proton and alpha-particle beams mainly by means of the Rutherford backscattering technique and in some few cases using the transmission method. The incident energies of the projectiles covers a wide range, from 200 keV up to 2000 keV for H{sup +} and from 200 keV up to 4000 keV for He{sup +} in zirconia films. In the case of alumina films the studied energy range was 100 keV - 3000 keV for H{sup +} and 100 keV - 6000 keV for He{sup +}. Our experimental results compare very well with theoretical calculations based on the dielectric formalism and a suitable description of the electronic excitation spectrum of ZrO{sub 2} and Al{sub 2}O{sub 3} films through their energy-loss function. (authors)

  12. Low energy particle composition

    International Nuclear Information System (INIS)

    Gloeckler, G.

    1975-01-01

    More than 50 papers presented at this Conference dealt with the composition of low energy particles. The topics can be divided roughly into two broad categories. The first is the study of the energy spectra and composition of the steady or 'quiet-time' particle flux, whose origin is at this time unknown. The second category includes the study of particles and photons which are associated with solar flares or active regions on the sun. (orig.) [de

  13. Studying the Range of Incident Alpha Particles on Cu , Ge , Ag , Cd , Te and Au, With Energy (4-15 MeV)

    International Nuclear Information System (INIS)

    Kadhim, R.O.; Jasim, W.N.

    2015-01-01

    In this paper theoretical calculation of the range for alpha particles with the energy range (4 – 15)MeV when passing in some metallic media (Cu , Ge , Ag , Cd , Te and Au).Semi empirical formula was used in addition to (SRIM-2012) program. The Semi empirical equation was programmed to calculate the range using Matlab Language.The results of the range in these media were compared with the results obtained from SRIM-2012 and )(2011)Andnet) results.There was good agreement among the semi empirical equation result , SRIM- 2012 results and with )(2011)Andnet) results in the low energy.The results showed exponential relation between the range of alpha particles in these media and the velocity of the particles.By recourse with SRIM- 2012 results and application them in Matlab program and by using Curve Fitting Tool we extraction equation with its constants to calculate the range of alpha particles in any element of these six elements with the energy range (4 – 15)MeV.The maximum deviation between the results from the semi empirical calculation and SRIM-2012 results was calculated the statistical test ( kstest2) in Matlab program

  14. Light particle production in spallation reactions induced by protons of 0.8-2.5 GeV incident kinetic energy

    International Nuclear Information System (INIS)

    Herbach, Claus-Michael; Enke, Michael; Boehm, Andreas

    2002-01-01

    Absolute production cross sections have been measured simultaneously for neutrons and light charged particles in 0.8-2.5 GeV proton induced spallation reactions for a series of target nuclei from aluminum up to uranium. The high detection efficiency both for neutral and charged evaporative particles provides an event-wise access to the amount of projectile energy dissipated into nuclear excitation. Various intra nuclear cascade plus evaporation models have been confronted with the experimental data showing large discrepancies for hydrogen and helium production. (author)

  15. Incident energy dependence of pt correlations at relativistic energies

    CERN Document Server

    Adams, J; Ahammed, Z; Amonett, J; Anderson, B D; Arkhipkin, D; Averichev, G S; Badyal, S K; Bai, Y; Balewski, J; Barannikova, O; Barnby, L S; Baudot, J; Bekele, S; Belaga, V V; Bellingeri-Laurikainen, A; Bellwied, R; Berger, J; Bezverkhny, B I; Bharadwaj, S; Bhasin, A; Bhati, A K; Bhatia, V S; Bichsel, H; Bielcik, J; Bielcikova, J; Billmeier, A; Bland, L C; Blyth, C O; Bonner, B E; Botje, M; Boucham, A; Bouchet, J; Brandin, A V; Bravar, A; Bystersky, M; Cadman, R V; Cai, X Z; Caines, H; Calderón de la Barca-Sanchez, M; Castillo, J; Catu, O; Cebra, D; Chajecki, Z; Chaloupka, P; Chattopadhyay, S; Chen, H F; Chen, Y; Cheng, J; Cherney, M; Chikanian, A; Christie, W; Coffin, J P; Cormier, T M; Cramer, J G; Crawford, H J; Das, D; Das, S; Daugherity, M; De Moura, M M; Dedovich, T G; Derevshchikov, A A; Didenko, L; Dietel, T; Dogra, S M; Dong, W J; Dong, X; Draper, J E; Du, F; Dubey, A K; Dunin, V B; Dunlop, J C; Dutta, M R; Mazumdar; Eckardt, V; Edwards, W R; Efimov, L G; Emelianov, V; Engelage, J; Eppley, G; Erazmus, B; Estienne, M; Fachini, P; Faivre, J; Fatemi, R; Fedorisin, J; Filimonov, K; Filip, P; Finch, E; Fine, V; Fisyak, Yu; Fu, J; Gagliardi, C A; Gaillard, L; Gans, J; Ganti, M S; Geurts, F; Ghazikhanian, V; Ghosh, P; González, J E; Gos, H; Grachov, O; Grebenyuk, O; Grosnick, D P; Guertin, S M; Guo, Y; Sen-Gupta, A; Gutíerrez, T D; Hallman, T J; Hamed, A; Hardtke, D; Harris, J W; Heinz, M; Henry, T W; Hepplemann, S; Hippolyte, B; Hirsch, A; Hjort, E; Hoffmann, G W; Huang, H Z; Huang, S L; Hughes, E W; Humanic, T J; Igo, G; Ishihara, A; Jacobs, P; Jacobs, W W; Jedynak, M; Jiang, H; Jones, P G; Judd, E G; Kabana, S; Kang, K; Kaplan, M; Keane, D; Kechechyan, A; Khodyrev, V Yu; Kiryluk, J; Kisiel, A; Kislov, E M; Klay, J; Klein, S R; Koetke, D D; Kollegger, T; Kopytine, M; Kotchenda, L; Kowalik, K L; Krämer, M; Kravtsov, P; Kravtsov, V I; Krüger, K; Kuhn, C; Kulikov, A I; Kumar, A; Kutuev, R K; Kuznetsov, A A; Lamont, M A C; Landgraf, J M; Lange, S; Laue, F; Lauret, J; Lebedev, A; Lednicky, R; Lehocka, S; Le Vine, M J; Li, C; Li, Q; Li, Y; Lin, G; Lindenbaum, S J; Lisa, M A; Liu, F; Liu, H; Liu, L; Liu, Q J; Liu, Z; Ljubicic, T; Llope, W J; Long, H; Longacre, R S; López-Noriega, M; Love, W A; Lu, Y; Ludlam, T; Lynn, D; Ma, G L; Ma, J G; Ma, Y G; Magestro, D; Mahajan, S; Mahapatra, D P; Majka, R; Mangotra, L K; Manweiler, R; Margetis, S; Markert, C; Martin, L; Marx, J N; Matis, H S; Matulenko, Yu A; McClain, C J; McShane, T S; Meissner, F; Melnik, Yu M; Meschanin, A; Miller, M L; Minaev, N G; Mironov, C; Mischke, A; Mishra, D K; Mitchell, J; Mohanty, B; Molnár, L; Moore, C F; Morozov, D A; Munhoz, M G; Nandi, B K; Nayak, S K; Nayak, T K; Nelson, J M; Netrakanti, P K; Nikitin, V A; Nogach, L V; Nurushev, S B; Odyniec, Grazyna Janina; Ogawa, A; Okorokov, V; Oldenburg, M; Olson, D; Pal, S K; Panebratsev, Yu A; Panitkin, S Y; Pavlinov, A I; Pawlak, T; Peitzmann, T; Perevozchikov, V; Perkins, C; Peryt, W; Petrov, V A; Phatak, S C; Picha, R; Planinic, M; Pluta, J; Porile, N; Porter, J; Poskanzer, A M; Potekhin, M V; Potrebenikova, E V; Potukuchi, B V K S; Prindle, D; Pruneau, C A; Putschke, J; Rakness, G; Raniwala, R; Raniwala, S; Ravel, O; Ray, R L; Razin, S V; Reichhold, D M; Reid, J G; Reinnarth, J; Renault, G; Retière, F; Ridiger, A; Ritter, H G; Roberts, J B; Rogachevski, O V; Romero, J L; Rose, A; Roy, C; Ruan, L; Russcher, M; Sahoo, R; Sakrejda, I; Salur, S; Sandweiss, J; Sarsour, M; Savin, I; Sazhin, P S; Schambach, J; Scharenberg, R P; Schmitz, N; Schweda, K; Seger, J; Seyboth, P; Shahaliev, E; Shao, M; Shao, W; Sharma, M; Shen, W Q; Shestermanov, K E; Shimansky, S S; Sichtermann, E P; Simon, F; Singaraju, R N; Smirnov, N; Snellings, R; Sood, G; Sørensen, P; Sowinski, J; Speltz, J; Spinka, H M; Srivastava, B; Stadnik, A; Stanislaus, T D S; Stock, R; Stolpovsky, A; Strikhanov, M N; Stringfellow, B C; Suaide, A A P; Sugarbaker, E R; Suire, C; Sumbera, M; Surrow, B; Swanger, M; Symons, T J M; Szanto de Toledo, A; Tai, A; Takahashi, J; Tang, A H; Tarnowsky, T J; Thein, D; Thomas, J H; Timoshenko, S; Tokarev, M; Trentalange, S; Tribble, R E; Tsai, O D; Ulery, J; Ullrich, T; Underwood, D G; Van Buren, G; Van Leeuwen, M; Van der Molen, A M; Varma, R; Vasilevski, I M; Vasilev, A N; Vernet, R; Vigdor, S E; Viyogi, Y P; Vokal, S; Voloshin, S A; Waggoner, W T; Wang, F; Wang, G; Wang, X L; Wang, Y; Wang, Z M; Ward, H; Watson, J W; Webb, J C; Westfall, G D; Wetzler, A; Whitten, C; Wieman, H; Wissink, S W; Witt, R; Wood, J; Wu, J; Xu, N; Xu, Z; Xu, Z Z; Yamamoto, E; Yepes, P; Yurevich, V I; Zborovský, I; Zhang, H; Zhang, W M; Zhang, Y; Zhang, Z P; Zoulkarneev, R; Zoulkarneeva, Y; Zubarev, A N

    2005-01-01

    We present results for two-particle transverse momentum correlations, , as a function of event centrality for Au+Au collisions at sqrt(sNN) = 20, 62, 130, and 200 GeV at the Relativistic Heavy Ion Collider. We observe correlations decreasing with centrality that are similar at all four incident energies. The correlations multiplied by the multiplicity density increase with incident energy and the centrality dependence may show evidence of processes such as thermalization, minijet production, or the saturation of transverse flow. The square root of the correlations divided by the event-wise average transverse momentum per event shows little or no beam energy dependence and generally agrees with previous measurements at the Super Proton Synchrotron.

  16. A single particle energies

    Energy Technology Data Exchange (ETDEWEB)

    Bodmer, A.R. [Illinois Univ., Chicago, IL (United States). Dept. of Physics]|[Argonne National Lab., IL (United States); Usmani, Q.N.; Sami, M. [Jamia Millia Islamia, New Delhi (India). Dept. of Physics

    1993-09-01

    We consider the binding energies of {Lambda} hypernuclei (HN), in particular the single-particle (s.p.) energy data, which have been obtained for a wide range of HN with mass numbers A {le} 89 and for orbital angular momenta {ell}{sub {Lambda}} {le} 4. We briefly review some of the relevant properties of A hypernuclei. These are nuclei {sub {Lambda}}{sup A}Z with baryon number A in which a single {Lambda} hyperon (baryon number = 1) is bound to an ordinary nucleus {sup A}Z consisting of A - 1 nucleons = Z protons + N neutrons. The {Lambda} hyperon is neutral, has spin 1/2, strangeness S = {minus}1, isospin I = O and a mass M{sub {Lambda}} = 1116 MeV/c{sup 2}. Although the {Lambda} interacts with a nucleon, its interaction is only about half as strong as that between two nucleons, and thus very roughly V{sub {Lambda}N} {approx} 0.5 V{sub NN}. As a result, the two-body {Lambda}N system is unbound, and the lightest bound HN is the three-body hypertriton {sub {Lambda}}{sup 3}H in which the {Lambda} is bound to a deuteron with the {Lambda}-d separation energy being only {approx} 0.1 MeV corresponding to an exponential tail of radius {approx} 15 fm! In strong interactions the strangeness S is of course conserved, and the {Lambda} is distinct from the nucleons. In a HN strangeness changes only in the weak decays of the {Lambda} which can decay either via ``free`` pionic decay {Lambda} {yields} N + {pi} or via induced decay {Lambda} + N {yields} N + N which is only possible in the presence of nucleons. Because of the small energy release the pionic decay is strongly suppressed in all but the lightest HN and the induced decay dominates. However, the weak decay lifetime {approx} 10{sup {minus}10}s is in fact close to the lifetime of a free {Lambda}. Since this is much longer than the strong interaction time {approx} 10{sup {minus}22}s we can ignore the weak interactions when considering the binding of HN, just as for ordinary nuclei.

  17. A single particle energies

    International Nuclear Information System (INIS)

    Bodmer, A.R.; Usmani, Q.N.; Sami, M.

    1993-01-01

    We consider the binding energies of Λ hypernuclei (HN), in particular the single-particle (s.p.) energy data, which have been obtained for a wide range of HN with mass numbers A ≤ 89 and for orbital angular momenta ell Λ ≤ 4. We briefly review some of the relevant properties of A hypernuclei. These are nuclei Λ A Z with baryon number A in which a single Λ hyperon (baryon number = 1) is bound to an ordinary nucleus A Z consisting of A - 1 nucleons = Z protons + N neutrons. The Λ hyperon is neutral, has spin 1/2, strangeness S = -1, isospin I = O and a mass M Λ = 1116 MeV/c 2 . Although the Λ interacts with a nucleon, its interaction is only about half as strong as that between two nucleons, and thus very roughly V ΛN ∼ 0.5 V NN . As a result, the two-body ΛN system is unbound, and the lightest bound HN is the three-body hypertriton Λ 3 H in which the Λ is bound to a deuteron with the Λ-d separation energy being only ∼ 0.1 MeV corresponding to an exponential tail of radius ∼ 15 fm exclamation point In strong interactions the strangeness S is of course conserved, and the Λ is distinct from the nucleons. In a HN strangeness changes only in the weak decays of the Λ which can decay either via ''free'' pionic decay Λ → N + π or via induced decay Λ + N → N + N which is only possible in the presence of nucleons. Because of the small energy release the pionic decay is strongly suppressed in all but the lightest HN and the induced decay dominates. However, the weak decay lifetime ∼ 10 -10 s is in fact close to the lifetime of a free Λ. Since this is much longer than the strong interaction time ∼ 10 -22 s we can ignore the weak interactions when considering the binding of HN, just as for ordinary nuclei

  18. Particle-gamma coincidence measurements in 12C+12C and 12C+Pb collisions at 2.1 GeV/nucleon incident energy

    International Nuclear Information System (INIS)

    Roche, G.; Koontz, R.; Mulera, T.; Pugh, H.G.; Schroeder, L.S.; Hallman, T.; Madansky, L.; Carroll, J.; Chang, C.C.; Kirk, P.N.; Krebs, G.; Vicente, J.

    1985-01-01

    A particle-gamma coincidence experiment has been performed with a 2.1 GeV per nucleon 12 C beam from the Bevalac. Data were taken with C and Pb targets. The γ-ray spectra are almost independent of the energy or the kind of charged particles detected in coincidence, mainly protons and deuterons. These γ-ray spectra are interpreted as resulting from π 0 decay, and are consistent with known π 0 production rates. A search for a possible decay of singly-charged anomalons into a gamma and a deuteron (or unbound proton-neutron system) has been done by studying the γp and γd invariant mass distributions. The upper limits for such a process are found to be 2 to 20% of the deuteron production rate, for anomalon masses for 200 to 400 MeV above the deuteron mass, with an anomalon mean lifetime of up to 10 -9 s, depending on which kind of decay process is considered. (orig.)

  19. Monte Carlo calculation of secondary electron emission from carbon-surface by obliquely incident particles

    International Nuclear Information System (INIS)

    Ohya, Kaoru; Kawata, Jun; Mori, Ichiro

    1990-01-01

    Incidence angle dependences of secondary electron emission from a carbon surface by low energy electron and hydrogen atom are calculated using Monte Carlo simulations on the kinetic emission model. The calculation shows very small increase or rather decrease of the secondary electron yield with oblique incidence. It is explained in terms of not only multiple elastic collisions of incident particles with the carbon atoms but also small penetration depth of the particles comparable with the escape depth of secondary electrons. In addition, the two types of secondary electron emission are distinguished by using the secondary electron yield statistics; one is the emission due to trapped particles in the carbon, and the other is that due to backscattered particles. The high-yield component of the statistics on oblique incidence is more suppressed than those on normal incidence. (author)

  20. High energy model for irregular absorbing particles

    International Nuclear Information System (INIS)

    Chiappetta, Pierre.

    1979-05-01

    In the framework of a high energy formulation of relativistic quantum scattering a model is presented which describes the scattering functions and polarization of irregular absorbing particles, whose dimensions are greater than the incident wavelength. More precisely in the forward direction an amplitude parametrization of eikonal type is defined which generalizes the usual diffraction theory, and in the backward direction a reflective model is used including a shadow function. The model predictions are in good agreement with the scattering measurements off irregular compact and fluffy particles performed by Zerull, Giese and Weiss (1977)

  1. [Medium energy particle physics

    International Nuclear Information System (INIS)

    Nefkens, B.M.K.

    1985-10-01

    Investigations currently carried out by the UCLA Particle Physics Research Group can be arranged into four programs: Pion-Nucleon Scattering; Tests of Charge Symmetry and Isospin Invariance; Light Nuclei (Strong Form Factors of 3 H, 3 He, 4 He; Detailed Balance in pd right reversible γ 3 H; Interaction Dynamics); and Search for the Rare Decay Μ + → e + + γ (MEGA). The general considerations which led to the choice of physics problems investigated by our group are given in the next section. We also outline the scope of the research being done which includes over a dozen experiments. The main body of this report details the research carried out in the past year, the status of various experiments, and new projects

  2. Particle energy and Hawking temperature

    International Nuclear Information System (INIS)

    Ding Chikun; Wang Mengjie; Jing Jiliang

    2009-01-01

    Some authors have recently found that the tunneling approach gives a different Hawking temperature for a Schwarzschild black hole in a different coordinate system. In this Letter, we find that to work out the Hawking temperature in a different coordinate system by the tunneling approach, we must use the correct definition of the energy of the radiating particles. By using a new definition of the particle energy, we obtain the correct Hawking temperature for a Schwarzschild black hole in two dynamic coordinate systems, the Kruskal-Szekers and dynamic Lemaitre coordinate systems.

  3. Particle production at collider energies

    International Nuclear Information System (INIS)

    Geich-Gimbel, C.

    1987-11-01

    Key features of the SPS panti p Collider and the detectors of the UA-experiments involved are dealt with in chapter 2, which includes and accord to the ramping mode of the Collider, which allowed to raise the c.m. energy to 900 GeV in the UA5/2 experiment. The following chapters concentrate on physics results. Starting with a discussion of cross sections and diffraction dissociation in chapter 3 we then continue with a presentation of basic features of particle production such as rapidity and multiplicity distributions in chapter 4. There one of the unexpected findings at Collider energies, the breakdown of the so-called KNO-scaling, and new regularities potentially governing multiplicity distributions, are discussed. The findings about correlations among the final state particles, which may tell about the underlying dynamics of multi-particle production and be relevant to models thereof, are described in due detail in chapter 5. Transverse spectra and their trends with energy are shown in chapter 6. Results on identified particles are collected in a separate chapter in order to stress that this piece of information was an important outcome of the UA5 experiment. (orig./HSI)

  4. Medium energy charged particle spectrometer

    International Nuclear Information System (INIS)

    Keppler, E.; Wilken, B.; Richer, K.; Umlauft, G.; Fischer, K.; Winterhoff, H.P.

    1976-10-01

    The charged particle spectrometer E8 on HELIOS A and B will be described in some detail. It covers proton energies from 80 keV to 6 MeV, electrons from 20 keV to 2 MeV, and positrons from 150 to 550 keV. Its flight performance will be discussed. From examples of measurements the capability of the instrument will be demonstrated. (orig.) [de

  5. High-energy particle diffraction

    International Nuclear Information System (INIS)

    Barone, V.; Predazzi, E.

    2002-01-01

    This monograph gives a comprehensive and up-to-date overview of soft and hard diffraction processes in strong interaction physics. The first part covers the general formalism (the optical analogy, the eikonal picture, high-energy kinematics, S-matrix theory) and soft hadron-hadron scattering (including the Regge theory) in a complete and mature presentation. It can be used as a textbook in particle physics classes. The remainder of the book is devoted to the 'new diffraction': the pomeron in QCD, low-x physics, diffractive deep inelastic scattering and related processes, jet production etc. It presents recent results and experimental findings and their phenomenological interpretations. This part addresses graduate students as well as researchers. (orig.)

  6. Particle accelerators and lasers high energy sources

    International Nuclear Information System (INIS)

    Watteau, J.P.

    1985-04-01

    Particle accelerators and lasers are to-day precious devices for physicist and engineer. Their performance and scope do not stop growing. Producing thin beams of high energy particles or photons, they are able to be very high energy sources which interact strongly with matter. Numerous applications use them: research, industry, communication, medicine, agroalimentary, defence, and soon. In this note, their operation principles are described and some examples of their use as high energy sources are given [fr

  7. Design of neutral particle incident heating apparatus for large scale helical apparatus

    Energy Technology Data Exchange (ETDEWEB)

    Kaneko, Osamu; Oka, Yoshihide; Osakabe, Masaki; Takeiri, Yasuhiko; Tsumori, Katsuyoshi; Akiyama, Ryuichi; Asano, Eiji; Kawamoto, Toshikazu; Kuroda, Tsutomu [National Inst. for Fusion Science, Nagoya (Japan)

    1997-02-01

    In the Institute of Nuclear Fusion Science, construction of the large scale helical apparatus has been progressed favorably, and constructions of the heating apparatus as well as of electron resonance apparatus were begun in their orders under predetermined manner since 1994 fiscal year. And, on 1995 fiscal year, construction of neutral particle incident heating apparatus, leading heat apparatus, was begun under 3 years planning. The plasma heating study system adopted the study results developed in this institute through the large scale hydrogen negative ion source and also adopted thereafter development on nuclear fusion study by modifying the original specification set at the beginning of the research plan before 7 years. As a result, system design was changed from initial 125 KeV to 180 KeV in the beam energy and to execute 15 MW incidence using two sets beam lines, to begin its manufacturing. Here is described on its new design with reason of its modifications. (G.K.)

  8. Particle production at AGS energies

    International Nuclear Information System (INIS)

    Steadman, S.G.; Rothschild, P.J.; Sung, T.W.; Zachary, D.

    1995-01-01

    The authors discuss particle production from 14.6 A·GeV/c Si and 11.6 A·GeV/c Au projectiles on Al and Au targets. The second-level trigger utilized by E859 allows high precision measurements of K - , bar p, Λ and bar Λ. The bar Λ yield is larger than expected, and a surprisingly large fraction of the bar p's are observed to arise from the decay of bar Λ

  9. Ultrahigh-energy particles from cosmic strings

    International Nuclear Information System (INIS)

    Bhattacharjee, P.

    1991-02-01

    The idea of production of ultrahigh-energy particles in the present universe due to annihilation or collapse of topological defects is discussed. Topological defects, formed in symmetry-breaking phase transitions in the early universe, can survive till today owing to their topological stability. However, under certain circumstances, topological defects may be physically destroyed. When topological defects are destroyed, the energy contained in the defects can be released in the form of massive gauge- and Higgs bosons of the underlying spontaneously broken gauge theory. Subsequent decay of these massive particles can give rise to energetic particles ranging up to an energy on the order of the mass of the original particles released from the defects. This may give us a ''natural'' mechanism of production of extremely energetic cosmic ray particles in the universe today, without the need for any acceleration mechanism. To illustrate this idea, I describe in detail the calculation of the expected ultrahigh-energy proton spectrum due to a specific process which involves collapse or multiple self-intersections of a class of closed cosmic string loops formed in a phase transition at a grand unification energy scale. I discuss the possibility that some of the highest-energy cosmic ray particles are of this origin. By comparing with the observational results on the ultrahigh-energy cosmic rays, we derive an upper limit to the average fraction of the total energy in all ''primary'' cosmic string loops that may be released in the form of particles due to collapse or multiple self-intersections of these loops. No nuclei such as α's or Fe's are in the spectrum. 43 refs., 3 figs

  10. Particle-gamma coincidence measurements in /sup 12/C+/sup 12/C and /sup 12/C+Pb collisions at 2. 1 GeV/nucleon incident energy

    Energy Technology Data Exchange (ETDEWEB)

    Roche, G.; Koontz, R.; Mulera, T.; Pugh, H.G.; Schroeder, L.S. (Lawrence Berkeley Lab., CA (USA)); Hallman, T.; Madansky, L. (Johns Hopkins Univ., Baltimore, MD (USA)); Carroll, J. (California Univ., Los Angeles (USA)); Chang, C.C. (Maryland Univ., College Park (USA)); Kirk, P.N.

    1985-06-24

    A particle-gamma coincidence experiment has been performed with a 2.1 GeV per nucleon /sup 12/C beam from the Bevalac. Data were taken with C and Pb targets. The ..gamma..-ray spectra are almost independent of the energy or the kind of charged particles detected in coincidence, mainly protons and deuterons. These ..gamma..-ray spectra are interpreted as resulting from ..pi../sup 0/ decay, and are consistent with known ..pi../sup 0/ production rates. A search for a possible decay of singly-charged anomalons into a gamma and a deuteron (or unbound proton-neutron system) has been done by studying the ..gamma..p and ..gamma..d invariant mass distributions. The upper limits for such a process are found to be 2 to 20% of the deuteron production rate, for anomalon masses for 200 to 400 MeV above the deuteron mass, with an anomalon mean lifetime of up to 10/sup -9/ s, depending on which kind of decay process is considered.

  11. Particle Settling in Low Energy Turbulence

    Science.gov (United States)

    Allen, Rachel; MacVean, Lissa; Tse, Ian; Mazzaro, Laura; Stacey, Mark; Variano, Evan

    2014-11-01

    Particle settling velocities can be altered by turbulence. In turbulence, dense particles may get trapped in convergent flow regions, and falling particles may be swept towards the downward side of turbulent eddies, resulting in enhanced settling velocities. The degree of velocity enhancement may depend on the Stokes number, the Rouse number, and the turbulent Reynolds number. In a homogeneous, isotropic turbulence tank, we tested the effects of particle size and type, suspended sediment concentration, and level of turbulence on the settling velocities of particles typically found in muddy estuaries. Two Acoustic Doppler Velocimeters (ADVs), separated vertically, measured turbulent velocities and suspended sediment concentrations, which yield condition dependent settling velocities, via ∂/á C ñ ∂ t = -∂/∂ z (ws á C ñ + á w ' C ' ñ) . These results are pertinent to fine sediment transport in estuaries, where high concentrations of suspended material are transported and impacted by low energy turbulence.

  12. Incident energy dependence of collision dynamics in A+A reactions from AGS to SPS

    International Nuclear Information System (INIS)

    Nara, Yasushi

    2000-01-01

    Based on the hadronic transport model of JAM, I calculate the time evolution of particles, density, temperature and energy density for the heavy ion collision at the incident energies of AGS(11A GeV), JHF(25A GeV) and SPS(158A GeV). Microscopic calculations show that resonance matter with extremely large baryon density is created at AGS energy, while at JHF energy, quark matter with extremely large baryon density is suggested. At SPS energy, quark matter with large baryon density might be created. (author)

  13. High energy particle collisions near black holes

    Directory of Open Access Journals (Sweden)

    Zaslavskii O. B.

    2016-01-01

    Full Text Available If two geodesic particles collide near a rotating black hole, their energy in the centre of mass frame Ec.m. can become unbound under certain conditions (the so-called BSW effect. The special role is played here by so-called critical geodesics when one of particles has fine-tuned energy and angular momentum. The nature of geodesics reveals itself also in fate of the debris after collisions. One of particles moving to a remote observer is necessarily near-critical. We discuss, when such a collision can give rise not only unboud Ec.m. but also unbound Killing energy E (so-called super-Penrose process.

  14. Medium-energy charged-particle data for evaluation

    International Nuclear Information System (INIS)

    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 charged-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 phenomenological evidence, are compared with experiment and, where validated, are used to fill in regions where experimental data are not available. Finally, the selected data are placed into computer-readable formats for use in transport calculations. Specialized indexes to bibliography help the scientist to keep up with his field and catch up with new subjects of interest. Several indexes are relevant to medium-energy nuclear data. In addition, these data are covered in several reports not issued on a regular basis. The technical area of medium-energy charged-particle data is maturing. From isolated measurements and theories, a comprehensive approach toward establishing a validated data base extending from low to high energies is emerging

  15. Dependence of extinction cross-section on incident polarization state and particle orientation

    International Nuclear Information System (INIS)

    Yang Ping; Wendisch, Manfred; Bi Lei; Kattawar, George; Mishchenko, Michael; Hu, Yongxiang

    2011-01-01

    This note reports on the effects of the polarization state of an incident quasi-monochromatic parallel beam of radiation and the orientation of a hexagonal ice particle with respect to the incident direction on the extinction process. When the incident beam is aligned with the six-fold rotational symmetry axis, the extinction is independent of the polarization state of the incident light. For other orientations, the extinction cross-section for linearly polarized light can be either larger or smaller than its counterpart for an unpolarized incident beam. Therefore, the attenuation of a quasi-monochromatic radiation beam by an ice cloud depends on the polarization state of the beam if ice crystals within the cloud are not randomly oriented. Furthermore, a case study of the extinction of light by a quartz particle is also presented to illustrate the dependence of the extinction cross-section on the polarization state of the incident light.

  16. Scattering of high-energy α particles on 12C

    International Nuclear Information System (INIS)

    Ahmad, I.

    1977-04-01

    Glauber multiple scattering theory is applied to analyse the elastic and inelastic scattering of 1.37 GeV α particles on 12 C. An approach which treats the N-α amplitude at the incident nucleon kinetic energy equal to the α-kinetic energy per particle as the basic interaction is adopted. Using the gaussian model for 4 He to obtain the N-α amplitude in terms of the NN amplitude, it is found that, in general, the experimental data are qualitatively explained. However, large discrepancies in terms of the magnitude of the cross-sections in the small angle region and the positions of the minima in the angular distribution at larger angles are generally present. Effects of the two-body correlations in the projectile as well as in the target are also investigated

  17. Power Supplies for High Energy Particle Accelerators

    Science.gov (United States)

    Dey, Pranab Kumar

    2016-06-01

    The on-going research and the development projects with Large Hadron Collider at CERN, Geneva, Switzerland has generated enormous enthusiasm and interest amongst all to know about the ultimate findings on `God's Particle'. This paper has made an attempt to unfold the power supply requirements and the methodology adopted to provide the stringent demand of such high energy particle accelerators during the initial stages of the search for the ultimate particles. An attempt has also been made to highlight the present status on the requirement of power supplies in some high energy accelerators with a view that, precautionary measures can be drawn during design and development from earlier experience which will be of help for the proposed third generation synchrotron to be installed in India at a huge cost.

  18. Superconductivity in high energy particle accelerators

    International Nuclear Information System (INIS)

    Schmueser, P.

    2002-08-01

    The basics of superconductivity are outlined with special emphasis on the features which are relevant for the application in magnets and radio frequency cavities for high energy particle accelerators. The special properties of superconducting accelerator magnets are described in detail: design principles, magnetic field calculations, magnetic forces, quench performance, persistent magnetization currents and eddy currents. The design principles and basic properties of superconducting cavities are explained as well as the observed performance limitations and the countermeasures. The ongoing research efforts towards maximum accelerating fields are addressed and the coupling of radio frequency power to the particle beam is treated. (orig.)

  19. Particle identification methods in High Energy Physics

    Energy Technology Data Exchange (ETDEWEB)

    Va' Vra, J.

    2000-01-27

    This paper deals with two major particle identification methods: dE/dx and Cherenkov detection. In the first method, the authors systematically compare existing dE/dx data with various predictions available in the literature, such as the Particle Data group recommendation, and judge the overall consistency. To my knowledge, such comparison was not done yet in a published form for the gaseous detectors used in High-Energy physics. As far as the second method, there are two major Cherenkov light detection techniques: the threshold and the Ring imaging methods. The authors discuss the recent trend in these techniques.

  20. Update of neutron dose yields as a function of energy for protons and deuterons incident on beryllium targets

    International Nuclear Information System (INIS)

    Ten Haken, R.K.; Awschalom, M.; Rosenberg, I.

    1982-11-01

    Neutron absorbed dose yields (absorbed dose rates per unit incident current on targets at a given SAD or SSD) increase with incident charged particle energy for both protons and deuterons. Analyses of neutron dose yield versus incident particle energy have been performed for both deuterons and protons. It is the purpose of this report to update those analyses by pooling all of the more recent published results and to reanalyze the trend of yield, Y, versus incident energy, E, which in the past has been described by an expression of the form Y = aE/sup b/, where a and b are empirical constants. From the reanalyzed trend it is concluded that for a given size cyclotron (E/sub p/ = 2E/sub d/), the dose yields using protons are higher than those using deuterons up to a proton energy E/sub p/ of 64 MeV

  1. Mass separated neutral particle energy analyser

    International Nuclear Information System (INIS)

    Takeuchi, Hiroshi; Matsuda, Toshiaki; Miura, Yukitoshi; Shiho, Makoto; Maeda, Hikosuke; Hashimoto, Kiyoshi; Hayashi, Kazuo.

    1983-09-01

    A mass separated neutral particle energy analyser which could simultaneously measure hydrogen and deuterium atoms emitted from tokamak plasma was constructed. The analyser was calibrated for the energy and mass separation in the energy range from 0.4 keV to 9 keV. In order to investigate the behavior of deuteron and proton in the JFT-2 tokamak plasma heated with ion cyclotron wave and neutral beam injection, this analyser was installed in JFT-2 tokamak. It was found that the energy spectrum could be determined with sufficient accuracy. The obtained ion temperature and ratio of deuteron and proton density from the energy spectrum were in good agreement with the value deduced from Doppler broadening of TiXIV line and the line intensities of H sub(α) and D sub(α) respectively. (author)

  2. Safety in design and operation of low energy particle accelerators

    International Nuclear Information System (INIS)

    Badawy, I.

    1991-01-01

    This paper studies the safety in design and operation of low energy accelerators which produce beams of accelerated charged particles and radiations. As radiation sources, the accelerators are widely used in scientific research, industry, food and medical applications. The risks to human and environment are considered. The safety in accelerators is discussed-particularly-the shielding against ionizing radiations, overexposure to RF radiation fire hazards and power failures. Also the paper studies the emergency response at incidents. Emergency procedures are recommended for each type of emergency. Reporting to the competent Authority is also recommended to be prepared for each incident. The basic principles of regulatory control, licensing and inspections for accelerator facilities are discussed. The relation with the competent authority is pointed out. 4 fig

  3. Energy-range relation and mean energy variation in therapeutic particle beams

    International Nuclear Information System (INIS)

    Kempe, Johanna; Brahme, Anders

    2008-01-01

    Analytical expressions for the mean energy and range of therapeutic light ion beams and low- and high-energy electrons have been derived, based on the energy dependence of their respective stopping powers. The new mean energy and range relations are power-law expressions relevant for light ion radiation therapy, and are based on measured practical ranges or known tabulated stopping powers and ranges for the relevant incident particle energies. A practical extrapolated range, R p , for light ions was defined, similar to that of electrons, which is very closely related to the extrapolated range of the primary ions. A universal energy-range relation for light ions and electrons that is valid for all material mixtures and compounds has been developed. The new relation can be expressed in terms of the range for protons and alpha particles, and is found to agree closely with experimental data in low atomic number media and when the difference in the mean ionization energy is low. The variation of the mean energy with depth and the new energy-range relation are useful for accurate stopping power and mass scattering power calculations, as well as for general particle transport and dosimetry applications

  4. Particle physics experiments at high energy colliders

    International Nuclear Information System (INIS)

    Hauptman, John

    2011-01-01

    Written by one of the detector developers for the International Linear Collider, this is the first textbook for graduate students dedicated to the complexities and the simplicities of high energy collider detectors. It is intended as a specialized reference for a standard course in particle physics, and as a principal text for a special topics course focused on large collider experiments. Equally useful as a general guide for physicists designing big detectors. (orig.)

  5. Charged particle accelerators for inertial fusion energy

    International Nuclear Information System (INIS)

    Humphries, S. Jr.

    1991-01-01

    The long history of successful commercial applications of charged-particle accelerators is largely a result of initiative by private industry. The Department of Energy views accelerators mainly as support equipment for particle physicists rather than components of an energy generation program. In FY 91, the DOE spent over 850 M$ on building and supporting accelerators for physics research versus 5 M$ on induction accelerators for fusion energy. The author believes this emphasis is skewed. One must address problems of long-term energy sources to preserve the possibility of basic research by future generations. In this paper, the author reviews the rationale for accelerators as inertial fusion drivers, emphasizing that these devices provide a viable path of fusion energy from viewpoints of both physics and engineering. In this paper, he covered the full range of accelerator fusion applications. Because of space limitations, this paper concentrates on induction linacs for ICF, an approach singled out in recent reports by the National Academy of Sciences and the Fusion Policy Advisory Committee as a promising path to long-term fusion power production. Review papers by Cook, Leung, Franzke, Hofmann and Reiser in these proceedings give details on light ion fusion and RF accelerator studies

  6. Multiple Coulomb scattering of high-energy heavy charged particle beams used in biology and medicine

    International Nuclear Information System (INIS)

    Wong, M.; Schimmerling, W.; Ludewigt, B.; Phillips, M.; Curtis, S.; Tobias, C.A.

    1987-01-01

    The authors measured lateral displacement and angular distributions of high-energy heavy charged particles emerging from a target at the Lawrence Berkeley Laboratory BEVALAC with beams used in radiobiology experiments. Multiple Coulomb scattering occurring in the target material generally spreads the beam laterally and increases its divergence. The apparatus consists of four sets of position-sensitive semiconductor detectors located along the beam line. Each providing two position signals and one energy signal. The difference between the two position signals is used to determine the particle position in one dimension. The two position signals are constrained to add up to the energy deposition signal in order to reject multiple-particle traversals. The vector directions for the incident and emerging particles are reconstructed in three dimensions from their measured coordinated positions. Lateral and angular distributions are reported for beams of high-energy neon, iron and uranium ions incident on targets of aluminum, cooper, lead and water

  7. Physicochemical characterization of discrete weapons grade plutonium metal particles originating from the 1960 BOMARC incident

    Science.gov (United States)

    Bowen, James M.

    The goal of this research was to investigate the physicochemical properties of weapons grade plutonium particles originating from the 1960 BOMARC incident for the purpose of predicting their fate in the environment and to address radiation protection and nuclear security concerns. Methods were developed to locate and isolate the particles in order to characterize them. Physical, chemical, and radiological characterization was performed using a variety of techniques. And finally, the particles were subjected to a sequential extraction procedure, a series of increasingly aggressive reagents, to simulate an accelerated environmental exposure. A link between the morphology of the particles and their partitioning amongst environmental mechanisms was established.

  8. Deflection of high energy channeled charged particles by elastically bent silicon single crystals

    International Nuclear Information System (INIS)

    Gibson, W.M.; Kim, I.J.; Pisharodoy, M.; Salman, S.M.; Sun, C.R.; Wang, G.H.; Wijayawardana, R.; Forster, J.S.; Mitchell, I.V.; Baker, S.I.; Carrigan, R.A. Jr.; Toohig, T.E.; Avdeichikov, V.V.; Ellison, J.A.; Siffert, P.

    1984-01-01

    An experiment has been carried out to observe the deflection of charged particles by planar channeling in bent single crystals of silicon for protons with energy up to 180 GeV. Anomolous loss of particles from the center point of a three point bending apparatus was observed at high incident particle energy. This effect has been exploited to fashion a 'dechanneling spectrometer' to study dechanneling effects due to centripital displacement of channeled particle trajectories in a bent crystal. The bending losses generally conform to the predictions of calculations based on a classical model. (orig.)

  9. Nuclear emulsion experiments on particle production at high energies

    International Nuclear Information System (INIS)

    Otterlund, I.

    1976-08-01

    Various experimental results, including multiplicities of shower-particles and heavy prong particles, correlations between them and single particle distributions, from proton-emulsion nucleus reactions in the energy range 200-400 GeV are presented. (Auth.)

  10. Particle Discrimination Experiment for Direct Energy Conversion

    International Nuclear Information System (INIS)

    Yasaka, Y.; Kiriyama, Y.; Yamamoto, S.; Takeno, H.; Ishikawa, M.

    2005-01-01

    A direct energy conversion system designed for D- 3 He fusion reactor based on a field reversed configuration employs a venetian-blind type converter for thermal ions to produce DC power and a traveling wave type converter for fusion protons to produce RF power. It is therefore necessary to separate, discriminate, and guide the particle species. For this purpose, a cusp magnetic field is proposed, in which the electrons are deflected and guided along the field line to the line cusp, while the ions pass through the point cusp. A small-scale experimental device was used to study the basic characteristics of discrimination of electrons and ions in the cusp magnetic field. Ions separated from electrons are guided to an ion collector, which is operated as a one-stage direct energy converter. The conversion efficiency was measured for cases with different values of mean and spread of ion energy. These experiments successfully demonstrate direct energy conversion from plasma beams using particle discrimination by a cusp magnetic field

  11. The acceleration of particles to high energy

    International Nuclear Information System (INIS)

    Parker, E.N.

    1976-01-01

    The common occurrence, and often spectacular consequence, of fast particles in active astrophysical bodies has attracted the attention of physicists for more than four decades. The acceleration mechanisms, whatever they may be, are remarkably efficient, converting a major fraction of the total energy into fast particles. A variety of ideas have arisen, suggesting how and why fast particles are generated in various circumstances. The principal limitation on particle acceleration theories has been the realization that the universe in not filled with a hard vacuum, but rather is pervaded everywhere by tenuous ionized gases quite able to short circuit any large-scale electric fields that occur under ordinary circumstances. A number of the early ideas on the acceleration of cosmic rays have been discarded for this reason. The basic theoretical ideas can be grouped roughly into five parts: 1. hydromagnetic fields; 2. field in reduced conductivity; 3. plasma turbulence; 4. low frequency electromagnetic waves; 5. supernova explosion. Each of these is considered in turn. (Auth.)

  12. High statistics study (approx.106 events) of J/psi production and T production in the energy range 150 to 280 GeV by π+-, p+- incident particle

    International Nuclear Information System (INIS)

    Badier, J.; Boucrot, J.; Bourotte, J.; Burgun, G.; Callot, O.; Charpentier, P.; Crozon, M.; Decamp, D.; Delpierre, P.; Diop, A.; Dube, R.; Espigat, P.; Gandois, B.; Hagelberg, R.; Hansroul, M.; Karyotakis, J.; Kienzle, W.; Lafontaine, A.; Le Du, P.; Lefrancois, J.; Leray, T.; Maillard, J.; Matthiae, G.; Michelini, A.; Mine, P.; Nguyen Ngoc, H.; Rahal, G.; Runolfsson, O.; Siegrist, P.; Tilquin, A.; Timmermans, J.; Valentin, J.; Vanderhaghen, R.; Weisz, S.

    1981-01-01

    We have performed in the NA3 experiment the study of high mass dimuon production by a hadronic unseparated beam on hydrogen and platinum targets. The comparison of the production cross-section for proton and antiproton together with the differential cross-section dsigma/dx allows us to compare the data with a production mechanism involving quark-antiquark and gluon-gluon interactions. The cosTHETA* distribution of the same J/psi data have also been analysed and results will be presented. Finally we have observed T production from 150 GeV/c incident pions

  13. High energy particle physics in the United Kingdom

    International Nuclear Information System (INIS)

    1985-06-01

    The paper reviews the U.K. participation in High Energy Particle Physics (HEPP) research. The funding of science in Higher Education and the Research Councils; high energy particle physics; relevance of particle physics to science and technology; particle physics in the U.K.; CERN; and the opportunity cost of HEPP within the science budget; are all discussed. (U.K.)

  14. Microwave and particle beam sources and directed energy concepts

    International Nuclear Information System (INIS)

    Brandt, H.E.

    1989-01-01

    This book containing the proceedings of the SPIE on microwave and particle beam sources and directed energy concepts. Topics covered include: High power microwave sources, Direct energy concepts, Advanced accelerators, and Particle beams

  15. Studies in theoretical high energy particle physics

    International Nuclear Information System (INIS)

    Aratyn, H.; Brekke, L.; Keung, Wai-Yee; Sukhatme, U.

    1993-01-01

    Theoretical work on the following topics is briefly summarized: symmetry structure of conformal affine Toda model and KP hierarchy; solitons in the affine Toda and conformal affine Toda models; classical r-matrices and Poisson bracket structures on infinite-dimensional groups; R-matrix formulation of KP hierarchies and their gauge equivalence; statistics of particles and solitons; charge quantization in the presence of an Alice string; knotting and linking of nonabelian flux; electric dipole moments; neutrino physics in gauge theories; CP violation in the high energy colliders; supersymmetric quantum mechanics; parton structure functions in nuclei; dual parton model. 38 refs

  16. Low-energy scattering of charged particles

    Energy Technology Data Exchange (ETDEWEB)

    Barrachina, R.O.; Garibotti, C.R. (Universidad Nacional de Cuyo, San Carlos de Bariloche (Argentina). Inst. Balseiro)

    1983-04-23

    The off-energy-shell T-matrix for two charged particles is studied in the low momentum limit (k->0). The T-matrix for a Coulomb interaction (Tsub(C)) is usually considered as the limit of the amplitude for a screened potential (Tsub(s)) when the screening is removed. We show that this statement is not true for small enough energies. For an attractive interaction Tsub(C) and Tsub(s) differ significantly when k->0. Tsub(c) behaves as ksup(-1/2), while Tsub(s) keeps its k/sup -1/ behaviour even when the screening is turned off. We note that this is an effect which would be observed in ion-atom collisions when one electron is ejected from the atom and captured into a continuum state of the ion.

  17. Low-energy scattering of charged particles

    Energy Technology Data Exchange (ETDEWEB)

    Barrachina, R.O.; Garibotti, C.R. (Instituto Balseiro, Argentina)

    1983-04-23

    The off-energy-shell T-matrix for two charged particles is studied in the low momentum limit ( k ->0 ). The T-matrix for a Coulomb interaction (Tsub(C)) is usually considered as the limit of the amplitude for a screened potential (Tsub(s)) when the screening is removed. This statement is not true for small enough energies. For an attractive interaction Tsub(C) and Tsub(s) differ significantly when k -> 0. Tsub(C) behaves as k sup(-0.5), while Tsub(s) keeps its k/sup -1/ behaviour even when the screening is turned off. This is an effect which would be observed in ion-atom collisions when one electron is ejected from the atom and captured into a continuum state of the ion.

  18. Colloids exposed to random potential energy landscapes: From particle number density to particle-potential and particle-particle interactions

    International Nuclear Information System (INIS)

    Bewerunge, Jörg; Capellmann, Ronja F.; Platten, Florian; Egelhaaf, Stefan U.; Sengupta, Ankush; Sengupta, Surajit

    2016-01-01

    Colloidal particles were exposed to a random potential energy landscape that has been created optically via a speckle pattern. The mean particle density as well as the potential roughness, i.e., the disorder strength, were varied. The local probability density of the particles as well as its main characteristics were determined. For the first time, the disorder-averaged pair density correlation function g (1) (r) and an analogue of the Edwards-Anderson order parameter g (2) (r), which quantifies the correlation of the mean local density among disorder realisations, were measured experimentally and shown to be consistent with replica liquid state theory results.

  19. Lateral particle density reconstruction from the energy deposits of particles in the KASCADE-Grande detector stations

    International Nuclear Information System (INIS)

    Toma, G.; Brancus, I.M.; Mitrica, B.; Sima, O.; Rebel, H.

    2005-01-01

    The study of primary cosmic rays with energies greater than 10 14 eV is done mostly by indirect observation techniques such as the study of Extensive Air Showers (EAS). In the much larger framework effort of inferring data on the mass and energy of the primaries from EAS observables, the present study aims at delivering a versatile method and software tool that will be used to reconstruct lateral particle densities from the energy deposits of particles in the KASCADE-Grande detector stations. The study has been performed on simulated events, by taking into account the interaction of the EAS components with the detector array (energy deposits). The energy deposits have been parametrized for different incident energies and angles. Thus it is possible to reconstruct the particle densities in detectors from the energy deposits. A correlation between lateral particle density and primary mass and primary energy (at ∼ 600 m from shower core) has been established. The study puts great emphasis on the quality of reconstruction and also on the speed of the technique. The data obtained from the study on simulated events will be used soon on real events detected by the KASCADE-Grande array. (authors)

  20. Digital PIV Measurements of Acoustic Particle Displacements in a Normal Incidence Impedance Tube

    Science.gov (United States)

    Humphreys, William M., Jr.; Bartram, Scott M.; Parrott, Tony L.; Jones, Michael G.

    1998-01-01

    Acoustic particle displacements and velocities inside a normal incidence impedance tube have been successfully measured for a variety of pure tone sound fields using Digital Particle Image Velocimetry (DPIV). The DPIV system utilized two 600-mj Nd:YAG lasers to generate a double-pulsed light sheet synchronized with the sound field and used to illuminate a portion of the oscillatory flow inside the tube. A high resolution (1320 x 1035 pixel), 8-bit camera was used to capture double-exposed images of 2.7-micron hollow silicon dioxide tracer particles inside the tube. Classical spatial autocorrelation analysis techniques were used to ascertain the acoustic particle displacements and associated velocities for various sound field intensities and frequencies. The results show that particle displacements spanning a range of 1-60 microns can be measured for incident sound pressure levels of 100-130 dB and for frequencies spanning 500-1000 Hz. The ability to resolve 1 micron particle displacements at sound pressure levels in the 100 dB range allows the use of DPIV systems for measurement of sound fields at much lower sound pressure levels than had been previously possible. Representative impedance tube data as well as an uncertainty analysis for the measurements are presented.

  1. Some problems of high-energy elementary particle physics

    International Nuclear Information System (INIS)

    Isaev, P.S.

    1995-01-01

    The problems of high-energy elementary particle physics are discussed. It is pointed out that the modern theory of elementary-particle physics has no solutions of some large physical problems: origin of the mass, electric charge, identity of particle masses, change of the mass of elementary particles in time and others. 7 refs

  2. Compressed beam directed particle nuclear energy generator

    International Nuclear Information System (INIS)

    Salisbury, W.W.

    1985-01-01

    This invention relates to the generation of energy from the fusion of atomic nuclei which are caused to travel towards each other along collision courses, orbiting in common paths having common axes and equal radii. High velocity fusible ion beams are directed along head-on circumferential collision paths in an annular zone wherein beam compression by electrostatic focusing greatly enhances head-on fusion-producing collisions. In one embodiment, a steady radial electric field is imposed on the beams to compress the beams and reduce the radius of the spiral paths for enhancing the particle density. Beam compression is achieved through electrostatic focusing to establish and maintain two opposing beams in a reaction zone

  3. Energy related applications of elementary particle physics

    International Nuclear Information System (INIS)

    Rafelski, J.

    1989-01-01

    Study of muon catalysis of nuclear fusion and phenomena commonly referred to as cold fusion has been central to our effort. Muon catalyzed fusion research concentrated primarily on the identification of energy efficient production of muons, and the understanding and control of the density dependence of auto-poisoning (sticking) of the catalyst. We have also developed the in-flight fusion description of the tμ-d reaction, and work in progress shows promise in explaining the fusion cycle anomalies and smallness of sticking as a consequence of the dominant role of such reactions. Our cold fusion work involved the exploration of numerous environments for cold fusion reactions in materials used in the heavy water electrolysis, with emphasis on reactions consistent with the conventional knowledge of nuclear physics reactions. We then considered the possibility that a previously unobserved ultra-heavy particle X - is a catalyst of dd fusion, explaining the low intensity neutrons observed by Jones et. al. 29 refs

  4. A time of flight detector for high energy heavy particles

    Energy Technology Data Exchange (ETDEWEB)

    Fang, Z; O` Connor, D J [Newcastle Univ., NSW (Australia). Dept. of Physics

    1994-12-31

    As a commonly used method to measure the energy of a particle with known mass, the flight time of the particle travelling over a certain distance is measured. A detector based on this principle is called a time-of-flight (TOF) detector which has attracted interests constantly during the last 15 years. For high energy heavy particle energy detection, TOF detector is an appropriated choice and such a system, developed recently, is described in this paper. 8 refs., 3 figs.

  5. A time of flight detector for high energy heavy particles

    Energy Technology Data Exchange (ETDEWEB)

    Fang, Z.; O`Connor, D.J. [Newcastle Univ., NSW (Australia). Dept. of Physics

    1993-12-31

    As a commonly used method to measure the energy of a particle with known mass, the flight time of the particle travelling over a certain distance is measured. A detector based on this principle is called a time-of-flight (TOF) detector which has attracted interests constantly during the last 15 years. For high energy heavy particle energy detection, TOF detector is an appropriated choice and such a system, developed recently, is described in this paper. 8 refs., 3 figs.

  6. Microscopic calculations of λ single particle energies

    International Nuclear Information System (INIS)

    Usmani, Q. N.

    1998-01-01

    Λ binding energy data for total baryon number A ≤ 208 and for Λ angular momenta ell Λ ≤ 3 are analyzed in terms of phenomenological (but generally consistent with meson-exchange) ΛN and ΛNN potentials. The Fermi-Hypernetted-Chain technique is used to calculate the expectation values for the Λ binding to nuclear matter. Accurate effective ΛN and ΛNN potentials are obtained which are folded with the core nucleus nucleon densities to calculate the Λ single particle potential U Λ (r). We use a dispersive ΛNN potential but also include an explicit ρ dependence to allow for reduced repulsion in the surface, and the best fits have a large ρ dependence giving consistency with the variational Monte Carlo calculations for Λ 5 He. The exchange fraction of the ΛN space-exchange potential is found to be 0.2-0.3 corresponding to m Λ * ≅ (0.74-0.82)m Λ . Charge symmetry breaking is found to be significant for heavy hypernuclei with a large neutron excess, with a strength consistent with that obtained from the A = 4 hypernuclei

  7. Interphasial energy transfer and particle dissipation in particle-laden wall turbulence

    NARCIS (Netherlands)

    Zhao, L.; Andersson, H.I.; Gillissen, J.J.J.

    2013-01-01

    Transfer of mechanical energy between solid spherical particles and a Newtonian carrier fluid has been explored in two-way coupled direct numerical simulations of turbulent channel flow. The inertial particles have been treated as individual point particles in a Lagrangian framework and their

  8. Fly ash particles spheroidization using low temperature plasma energy

    OpenAIRE

    Shekhovtsov, V. V.; Volokitin, O. G.; Vitske, Rudolf Evaldovich; Kondratyuk, Alexey Alekseevich

    2016-01-01

    The paper presents the investigations on producing spherical particles 65-110 [mu]m in size using the energy of low temperature plasma (LTP). These particles are based on flow ash produced by the thermal power plant in Seversk, Tomsk region, Russia. The obtained spherical particles have no defects and are characterized by a smooth exterior surface. The test bench is designed to produce these particles. With due regard for plasma temperature field distribution, it is shown that the transition ...

  9. Fluctuations in high-energy particle collisions

    International Nuclear Information System (INIS)

    Gronqvist, Hanna

    2016-01-01

    We study fluctuations that are omnipresent in high-energy particle collisions. These fluctuations can be either of either classical or quantum origin and we will study both. Firstly, we consider the type of quantum fluctuations that arise in proton-proton collisions. These are computable perturbatively in quantum field theory and we will focus on a specific class of diagrams in this set-up. Secondly, we will consider the fluctuations that are present in collisions between nuclei that can be heavier than protons. These are the quantum laws of nature that describe the positions of nucleons within a nucleus, but also the hydrodynamic fluctuations of classical, thermal origin that affect the evolution of the medium produced in heavy-ion collisions. The fluctuations arising in proton-proton collisions can be computed analytically up to a certain order in perturbative quantum field theory. We will focus on one-loop diagrams of a fixed topology. Loop diagrams give rise to integrals that typically are hard to evaluate. We show how modern mathematical methods can be used to ease their computation. We will study the relations among unitarity cuts of a diagram, the discontinuity across the corresponding branch cut and the coproduct. We show how the original integral corresponding to a given diagram can be reconstructed from the information contained in the coproduct. We expect that these methods can be applied to solve more complicated topologies and help in the computation of new amplitudes in the future. Finally, we study the two types of fluctuations arising in heavy-ion collisions. These are related either to the initial state or the intermediate state of matter produced in such collisions. The initial state fluctuations are experimentally observed to give rise to non-Gaussianities in the final-state spectra. We show how these non-Gaussianities can be explained by the random position and interaction energy of 'sources' in the colliding nuclei. Furthermore, we

  10. Enhancement of particle-wave energy exchange by resonance sweeping

    International Nuclear Information System (INIS)

    Berk, H.L.; Breizman, B.N.

    1995-10-01

    It is shown that as the resonance condition of the particle-wave interaction is varied adiabatically, that the particles trapped in the wave will form phase space holes or clumps that can enhance the particle-wave energy exchange. This mechanism can cause much larger saturation levels of instabilities, and even allow the free energy associated with instability, to be tapped in a system that is linearly stable due to background dissipation

  11. Radiation safety aspects of high energy particle accelerators

    International Nuclear Information System (INIS)

    Subbaiah, K.V.

    2007-01-01

    High-energy accelerators are widely used for various applications in industry, medicine and research. These accelerators are capable of accelerating both ions and electrons over a wide range of energy and subsequently are made to impinge on the target materials. Apart from generating intended reactions in the target, these projectiles can also generate highly penetrating radiations such as gamma rays and neutrons. Over exposure to these radiations will cause deleterious effects on the living beings. Various steps taken to protect workers and general public from these harmful radiations is called radiation safety. The primary objective in establishing permissible values for occupational workers is to keep the radiation worker well below a level at which adverse effects are likely to be observed during one's life time. Another objective is to minimize the incidence of genetic effects for the population as a whole. Today's presentation on radiation safety of accelerators will touch up on the following sub-topics: Types of particle accelerators and their applications; AERB directives on dose limits; Radiation Source term of accelerators; Shielding Design-Use of Transmission curves and Tenth Value layers; Challenges for accelerator health physicists

  12. High-energy nuclear optics of polarized particles

    CERN Document Server

    Baryshevsky, Vladimir G

    2012-01-01

    The various phenomena caused by refraction and diffraction of polarized elementary particles in matter have opened up a new research area in the particle physics: nuclear optics of polarized particles. Effects similar to the well-known optical phenomena such as birefringence and Faraday effects, exist also in particle physics, though the particle wavelength is much less than the distance between atoms of matter. Current knowledge of the quasi-optical effects, which exist for all particles in any wavelength range (and energies from low to extremely high), will enable us to investigate different properties of interacting particles (nuclei) in a new aspect. This pioneering book will provide detailed accounts of quasi-optical phenomena in the particle polarization, and will interest physicists and professionals in experimental particle physics.

  13. Cosmic censorship, area theorem, and self-energy of particles

    International Nuclear Information System (INIS)

    Hod, Shahar

    2002-01-01

    The (zeroth-order) energy of a particle in the background of a black hole is given by Carter's integrals. However, exact calculations of a particle's self-energy (first-order corrections) are still beyond our present reach in many situations. In this paper we use Hawking's area theorem in order to derive bounds on the self-energy of a particle in the vicinity of a black hole. Furthermore, we show that self-energy corrections must be taken into account in order to guarantee the validity of Penrose's cosmic censorship conjecture

  14. If there is dissipation the particle can gain energy

    International Nuclear Information System (INIS)

    De Carvalho, R Egydio

    2015-01-01

    In this work, we summarize two different mechanisms to gain energy from the presence of dissipation in a time-dependent non-linear system. The particles can gain energy, in the average, from two different scenarios: i) for very week dissipation with the creation of an attractor with high velocity, and ii) in the opposite limit, for very strong dissipation, the particles can also gain energy from a boundary crisis. From the thermodynamic viewpoint both results are totally acceptable. (paper)

  15. The fine particle emissions of energy production in Finland

    International Nuclear Information System (INIS)

    Ohlstroem, M.

    1998-01-01

    The main purpose of this master's thesis was to define the fine particle (PM2.5, diameter under 2,5 μm) emissions of the energy production and to compare the calculated emission factors between different energy production concepts. The purpose was also to define what is known about fine particle emissions and what should still be studied/measured. The purpose was also to compare briefly the fine particle emissions of energy production and vehicle traffic, and their correlations to the fine particle concentrations of urban air. In the theory part of this work a literature survey was made about fine particles in energy production, especially how they form and how they are separated from the flue gas. In addition, the health effects caused by fine particles, and different measuring instruments were presented briefly. In the experimental part of this work, the aim was to find out the fine particle emissions of different energy production processes by calculating specific emission factors (mg/MJ fuel ) from powerplants' annual total particulate matter emissions (t/a), which were obtained from VAHTI-database system maintained by the Finnish Environmental Institute, and by evaluating the share of fine particles from total emissions with the help of existing measurement results. Only those energy production processes which produce significantly direct emissions of solid particles have been treated (pulverised combustion and oil burners from burner combustion, fluidized bed combustion processes, grate boilers, recovery boilers and diesel engines). The processes have been classified according to boiler type, size category, main fuel and also according to dust separation devices. To be able to compare different energy production processes, shared specific emission factor have been calculated for the similar subprocesses. The fine particle emissions depend strongest on the boiler size category and dust separation devices used. Spent fuel or combustion technique does not have

  16. Energy becomes riddle for particle physics

    CERN Multimedia

    Nancy, J

    2003-01-01

    Assuming Einstein's theory of gravity is correct, dark energy must be present in the universe. Physicist's attempts to use quantum field theory to find the amount of dark energy present though, have been very unsuccessful (1/2 page).

  17. Calorimetry energy measurement in particle physics

    CERN Document Server

    Wigmans, Richard

    2017-01-01

    Particle physics is the science that pursues the age-old quest for the innermost structure of matter and the fundamental interactions between its constituents. Modern experiments in this field rely increasingly on calorimetry, a detection technique in which the particles of interest are absorbed in the detector. Calorimeters are very intricate instruments. Their performance characteristics depend on subtle, sometimes counter-intuitive design details. This book, written by one of the world's foremost experts, is the first comprehensive text on this topic. It provides a fundamental and systematic introduction to calorimetry. It describes the state of the art in terms of both the fundamental understanding of calorimetric particle detection, and the actual detectors that have been or are being built and operated in experiments. The last chapter discusses landmark scientific discoveries in which calorimetry has played an important role. This book summarizes and puts into perspective the work described in some 900...

  18. Morphology of ductile metals eroded by a jet of spherical particles impinging at normal incidence

    Science.gov (United States)

    Veerabhadra Rao, P.; Young, S. G.; Buckley, D. H.

    1983-01-01

    Scanning electron microscopy and energy-dispersive X-ray spectroscopy are used, together with surface profile measurements, in the present morphological study of the erosion of an aluminum alloy and copper by the normal impact of spherical glass erodent particles. The morphology of the damage pattern is a manifestation of the flow pattern of erodent particles, and yields insight into the mechanisms that may be active at different stages of erosion. The simultaneous appearance of radial cracks and concentric rings is reported, together with wave crests which contain an accumulation of metallic flakes. A preliminary analysis is advanced to explain the formation of the various damage patterns observed.

  19. High energy particle accelerators as radiation Sources

    Energy Technology Data Exchange (ETDEWEB)

    Abdelaziz, M E [National Center for Nuclear Safety and Radiation Vontrol, Atomic Energy Authority, Cairo (Egypt)

    1997-12-31

    Small accelerators in the energy range of few million electron volts are usually used as radiation sources for various applications, like radiotherapy, food irradiation, radiation sterilization and in other industrial applications. High energy accelerators with energies reaching billions of electron volts also find wide field of applications as radiation sources. Synchrotrons with high energy range have unique features as radiation sources. This review presents a synopsis of cyclic accelerators with description of phase stability principle of high energy accelerators with emphasis on synchrotrons. Properties of synchrotron radiation are given together with their applications in basic and applied research. 13 figs.,1 tab.

  20. Low-energy particle treatment of GaAs surface

    International Nuclear Information System (INIS)

    Pincik, E.; Ivanco, J.; Brunner, R.; Jergel, M.; Falcony, C.; Ortega, L.; Kucera, J. M.

    2002-01-01

    The paper presents results of a complex study of surface properties of high-doped (2x10 18 cm -3 ) and semi-insulating GaAs after an interaction with the particles coming from low-energy ion sources such as RF plasma and ion beams. The virgin samples were mechano-chemically polished liquid-encapsulated Czochralski-grown GaAs (100) oriented wafers. The crystals were mounted on the grounded electrode (holder). The mixture Ar+H 2 as well as O 2 and CF 4 were used as working gases: In addition, a combination of two different in-situ exposures was applied, such as e.g. hydrogen and oxygen. Structural, electrical and optical properties of the exposed surfaces were investigated using X-ray diffraction at grazing incidence, quasi-static and high-frequency C-V curve measurements, deep-level transient spectroscopy, photo-reflectance, and photoluminescence. Plasma and ion beam exposures were performed in a commercial RF capacitively coupled plasma equipment SECON XPL-200P and a commercial LPAI device, respectively. The evolution of surface properties as a function of the pressure of working gas and the duration of exposure was observed. (Authors)

  1. 18 CFR 1316.9 - Nuclear energy hazards and nuclear incidents.

    Science.gov (United States)

    2010-04-01

    ... 18 Conservation of Power and Water Resources 2 2010-04-01 2010-04-01 false Nuclear energy hazards... Text of Conditions and Certifications § 1316.9 Nuclear energy hazards and nuclear incidents. When so... documents or actions: Nuclear Energy Hazards and Nuclear Incidents (Applicable only to contracts for goods...

  2. Acceleration of low energy charged particles by gravitational waves

    Energy Technology Data Exchange (ETDEWEB)

    Voyatzis, G. [University of Thessaloniki, Department of Physics, 54124 Thessaloniki (Greece)]. E-mail: voyatzis@auth.gr; Vlahos, L. [University of Thessaloniki, Department of Physics, 54124 Thessaloniki (Greece); Ichtiaroglou, S. [University of Thessaloniki, Department of Physics, 54124 Thessaloniki (Greece); Papadopoulos, D. [University of Thessaloniki, Department of Physics, 54124 Thessaloniki (Greece)

    2006-04-03

    The acceleration of charged particles in the presence of a magnetic field and gravitational waves is under consideration. It is shown that the weak gravitational waves can cause the acceleration of low energy particles under appropriate conditions. Such conditions may be satisfied close to the source of the gravitational waves if the magnetized plasma is in a turbulent state.

  3. Acceleration of low energy charged particles by gravitational waves

    International Nuclear Information System (INIS)

    Voyatzis, G.; Vlahos, L.; Ichtiaroglou, S.; Papadopoulos, D.

    2006-01-01

    The acceleration of charged particles in the presence of a magnetic field and gravitational waves is under consideration. It is shown that the weak gravitational waves can cause the acceleration of low energy particles under appropriate conditions. Such conditions may be satisfied close to the source of the gravitational waves if the magnetized plasma is in a turbulent state

  4. [High energy particle physics at Purdue, 1990--1991

    International Nuclear Information System (INIS)

    Gaidos, J.A.; Loeffler, F.J.; McIlwain, R.L.; Miller, D.H.; Palfrey, T.R.; Shibata, E.I.; Shipsey, I.P.

    1991-05-01

    Progress made in the experimental and theoretical high energy physics program is reviewed. The CLEO experiment, particle astrophysics, dynamical symmetry breaking in gauge theories, the Collider Detector at Fermilab, the TOPAZ Experiment, and elementary particle physics beyond the standard model are included

  5. High energy particle experiment for the GEOTAIL mission

    International Nuclear Information System (INIS)

    1989-09-01

    The high energy particle experiment for GEOTAIL mission was designed to understand the particle acceleration mechanism, energy flow, boundary dynamics and magnetic reconnection mechanism in the geotail region, solar flare particle acceleration mechanism, the propagation mechanism through interplanetary space, and the origin, lifetime and propagation mechanism of cosmic ray heavy ions. In order to achieve these objectives, particle detectors, burst detectors, medium energy isotope telescopes and a high energy isotope telescope will be placed in the spacecraft which will be launched in 1992 as one of the spacecraft missions in the International Solar Terrestrial Physics program. With these detectors, electrons, protons and helium, carbon, silicon and iron particles will be detected. The characteristics and the main technique used for each instrument to observe high energy particles are summarized. The details of the scientific objectives, the basic principle of particle identification, the electronic system and data processing system, key parameter information, telemetry data formats, preflight and in-flight calibration method and data an analysis plan are described in this report. (K.I.)

  6. Electromagnetic energy and momentum from a charged particle

    International Nuclear Information System (INIS)

    Marx, E.

    1975-01-01

    The flux of the stress-energy tensor across a tube surrounding the world line of a charged particle is computed. By slight modifications of the definition of the Coulomb energy-momentum, the resulting expression contains the radiation reaction term (proportional to the square of the four-acceleration) but not the Schott term (proportional to the derivative of the acceleration). The equation of motion for the particle derived from this expression implies a variable rest mass. (author)

  7. Transverse energy distribution, charged particle multiplicities and spectra in 16O-nucleus collisions

    International Nuclear Information System (INIS)

    Sunier, J.W.

    1987-01-01

    The HELIOS (High Energy Lepton and Ion Spectrometer) experiment, installed at the CERN Super Proton Synchrotron, proposes to examine in details the physical properties of a state of high energy created in nuclei by ultra-relativistic nucleus-nucleus collisions. It is generally believed that, at high densities or temperatures, a phase transition to a plasma of quark and gluons will occur. The dynamic of the expansion of such a plasma and its subsequent condensation into a hadron gas should markedly affect the composition and momentum distribution of the emerging particles and photons. The HELIOS experimental setup therefore combines 4π calorimetric coverage with measurements of inclusive particle spectra, two particle correlations, low and high mass lepton pairs and photons. The emphasis is placed on transverse energy flow (E/sub T/) measurements with good energy resolution, and the ability to trigger the acquisition of data in a variety of E/sub T/ ranges, thereby selecting the impact parameter or the violence of the collisions. This short note presents HELIOS results, for the most part still preliminary, on 16 O-nucleus collisions at the incident energies of 60 and 200 GeV per nucleon. The E/sub T/ distributions from Al, Ag and W targets are discussed and compared to the associated charged particle multiplicities from W. Charged particle and (converted) photon spectra measured with the external magnetic spectrometer are compared for 16 O + W and p + W collisions at 200 GeV per nucleon. 5 refs., 7 figs

  8. Limit on possible energy-dependent velocities for massless particles

    International Nuclear Information System (INIS)

    Haines, T.J.; Alexandreas, D.E.; Allen, R.C.; Biller, S.; Berley, D.; Burman, R.L.; Cady, D.R.; Chang, C.Y.; Dingus, B.L.; Dion, G.M.; Ellsworth, R.W.; Goodman, J.A.; Hoffman, C.M.; Lloyd-Evans, J.; Nagle, D.E.; Potter, M.; Sandberg, V.D.; Wilkinson, C.A.; Yodh, G.B.

    1990-01-01

    A basic tenet of special relativity is that all massless particles travel at a constant, energy-independent velocity. Astrophysical data, including observation of the Crab pulsar at ∼100 MeV and the recent detection of the pulsar in Hercules X-1 at energies ≥100 TeV, are used to place new experimental constraints on energy-dependent deviations from constant velocity for massless particles. Previous experiments reached energies ∼10 GeV; this analysis improves the previous constraints by 7 orders of magnitude

  9. Studies In Theoretical High Energy Particle Physics

    Energy Technology Data Exchange (ETDEWEB)

    Keung, Wai Yee [Univ. of Illinois, Chicago, IL (United States)

    2017-07-01

    This is a final technical report for grant no. DE-SC0007948 describing research activities in theoretical high energy physics at University of Illinois at Chicago for the whole grant period from July 1, 2012 to March 31, 2017.

  10. Elementary particle physics and high energy phenomena

    International Nuclear Information System (INIS)

    Barker, A.R.; Cumalat, J.P.; de Alwis, S.P.; DeGrand, T.A.; Ford, W.T.; Mahanthappa, K.T.; Nauenberg, U.; Rankin, P.; Smith, J.G.

    1992-06-01

    This report discusses the following research in high energy physics: the properties of the z neutral boson with the SLD detector; the research and development program for the SDC muon detector; the fixed-target k-decay experiments; the Rocky Mountain Consortium for HEP; high energy photoproduction of states containing heavy quarks; and electron-positron physics with the CLEO II and Mark II detectors. (LSP)

  11. Elementary particle physics and high energy phenomena

    Energy Technology Data Exchange (ETDEWEB)

    Barker, A.R.; Cumalat, J.P.; de Alwis, S.P.; DeGrand, T.A.; Ford, W.T.; Mahanthappa, K.T.; Nauenberg, U.; Rankin, P.; Smith, J.G.

    1992-06-01

    This report discusses the following research in high energy physics: the properties of the z neutral boson with the SLD detector; the research and development program for the SDC muon detector; the fixed-target k-decay experiments; the Rocky Mountain Consortium for HEP; high energy photoproduction of states containing heavy quarks; and electron-positron physics with the CLEO II and Mark II detectors. (LSP).

  12. Elementary particle physics and high energy phenomena

    International Nuclear Information System (INIS)

    Barker, A.R.; Cumalat, J.P.; De Alwis, S.P.; DeGrand, T.A.; Ford, W.T.; Mahanthappa, K.T.; Nauenberg, U.; Rankin, P.; Smith, J.G.

    1992-06-01

    Experimental and theoretical high-energy physics programs at the University of Colorado are reported. Areas of concentration include the following: study of the properties of the Z 0 with the SLD detector; fixed-target K-decay experiments; the R ampersand D program for the muon system: the SDC detector; high-energy photoproduction of states containing heavy quarks; electron--positron physics with the CLEO II detector at CESR; lattice QCD; and spin models and dynamically triangulated random surfaces. 24 figs., 2 tabs., 117 refs

  13. Nuclear energy levels and elementary particles

    International Nuclear Information System (INIS)

    de Wet, J.A.

    1982-01-01

    Considering only exchange forces, the binding energies and excited states of nuclei up to 24 Mg are predicted to within charge independence, and there is no reason why the model should not be extended to cover all of the elements. A comparison of theory with experiment shows that the energy of one exchange is 2.56 MeV. Moreover, there is an attractive well of depth 30 MeV, corresponding to the helium nucleus. before exchange forces become operative. A possible explanation of the origin of mesons is also presented

  14. (Medium energy particle physics): Annual progress report

    Energy Technology Data Exchange (ETDEWEB)

    Nefkens, B.M.K.

    1985-10-01

    Investigations currently carried out by the UCLA Particle Physics Research Group can be arranged into four programs: Pion-Nucleon Scattering; Tests of Charge Symmetry and Isospin Invariance; Light Nuclei (Strong Form Factors of /sup 3/H, /sup 3/He, /sup 4/He; Detailed Balance in pd /r reversible/ /gamma//sup 3/H; Interaction Dynamics); and Search for the Rare Decay /Mu//sup +/ /yields/ e/sup +/ + /gamma/ (MEGA). The general considerations which led to the choice of physics problems investigated by our group are given in the next section. We also outline the scope of the research being done which includes over a dozen experiments. The main body of this report details the research carried out in the past year, the status of various experiments, and new projects.

  15. Energy related applications of elementary particle physics

    International Nuclear Information System (INIS)

    Rafelski, J.

    1991-01-01

    The current research position is summarized, and what could be done in the future to clarify issues which were opened up by the research is indicated. Following on the discussion of the viability of catalyzed fusion, there is presented along with the key experimental results, a short account of the physics surrounding the subject. This is followed by a discussion of key research topics addressed. In consequence of the progress made, it appears that the feasibility of a small-scale fusion based on catalyzed reactions rests on either the remote chance that a yet undiscovered ultraheavy negatively charged elementary particle exists in Nature, or on the possible technical realization of a system based on muon-catalyzed fusion (MuCF) in high-density degenerate hydrogen plasma (density 1000 LHD, temperature O(100 eV)). The lattter is considered to have practical promise

  16. Studies in theorectical high energy particles physics

    International Nuclear Information System (INIS)

    Aratyn, H.; Keung, Wai-Yee; Panigrahi, P.; Sukhatme, U.

    1990-02-01

    This paper discusses the research being done at the University of Illinois in theoretical high energy physics. Some areas discussed are string models, collider physics, symmetries in gauge theories, sigma model, radiative decay of mesons, supersymmetry, superconducting, and hydroproduction of charm

  17. Calculated performance of iron--argon and iron--plastic calorimeters for incident hadrons with energies of 5 to 75 GeV

    International Nuclear Information System (INIS)

    Gabriel, T.A.; Schmidt, W.

    1976-02-01

    The calculated responses of iron--argon and iron--plastic calorimeters for incident hadrons with energies of 5 to 75 GeV are presented. The responses calculated are energy resolution vs energy, energy resolution vs the thickness of the sampling plates, the angular and spatial root-mean-square deviations (i.e., the ability to determine the incident particle's entrance angle and impact point), and the spatial properties of the average and individual hadronic cascades. Some comparisons are made with experimental data; however, the main purpose of this paper is to provide specific design information for these types of calorimeters

  18. Using Energy Peaks to Measure New Particle Masses

    CERN Document Server

    Agashe, Kaustubh; Kim, Doojin

    2014-01-01

    We discussed in arXiv:1209.0772 that the laboratory frame distribution of the energy of a massless particle from a two-body decay at a hadron collider has a peak whose location is identical to the value of this daughter's (fixed) energy in the rest frame of the corresponding mother particle. For that result to hold we assumed that the mother is unpolarized and has a generic boost distribution in the laboratory frame. In this work we discuss how this observation can be applied for determination of masses of new particles, without requiring a full reconstruction of their decay chains or information about the rest of the event. We focus on a two-step cascade decay of a massive particle that has one invisible particle in the final state: C -> Bb -> Aab, where C, B and A are new particles of which A is invisible and a, b are visible particles. Combining the measurements of the peaks of energy distributions of a and b with that of the edge in their invariant mass distribution, we demonstrate that it is in principle...

  19. Critical analysis of major incidents risks in civil nuclear energy

    International Nuclear Information System (INIS)

    2000-09-01

    The differences existing between the PWR type reactors and the RBMK type reactors are explained as well as the risk associated to each type when it exists. The Ines scale, tool to give the level of an accident gravity comprises seven levels, the number seven is the most serious and corresponds to the Chernobyl accident; The number zero is of no consequence but must be mentioned as a matter of form. The incidents from 1 to 3 concern increasing incidents, affecting the nuclear power plant but not the external public. The accidents from 4 to 7 have a nature to affect the nuclear power plant and the environment. An efficient tool exists between nuclear operators it is made of the reports on incidents encountered by close reactors. Two others type reactors are coming, the high temperature type reactors and the fast neutrons reactors. different risks are evoked, terrorism, proliferation, transport and radioactive wastes. (N.C.)

  20. Charged-particle multiplicity at LHC energies

    CERN Multimedia

    CERN. Geneva

    2010-01-01

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

  1. Nuclear reactions induced by high-energy alpha particles

    Science.gov (United States)

    Shen, B. S. P.

    1974-01-01

    Experimental and theoretical studies of nuclear reactions induced by high energy protons and heavier ions are included. Fundamental data needed in the shielding, dosimetry, and radiobiology of high energy particles produced by accelerators were generated, along with data on cosmic ray interaction with matter. The mechanism of high energy nucleon-nucleus reactions is also examined, especially for light target nuclei of mass number comparable to that of biological tissue.

  2. Numerical evaluation of high energy particle effects in magnetohydrodynamics

    International Nuclear Information System (INIS)

    White, R.B.; Wu, Y.

    1994-03-01

    The interaction of high energy ions with magnetohydrodynamic modes is analyzed. A numerical code is developed which evaluates the contribution of the high energy particles to mode stability using orbit averaging of motion in either analytic or numerically generated equilibria through Hamiltonian guiding center equations. A dispersion relation is then used to evaluate the effect of the particles on the linear mode. Generic behavior of the solutions of the dispersion relation is discussed and dominant contributions of different components of the particle distribution function are identified. Numerical convergence of Monte-Carlo simulations is analyzed. The resulting code ORBIT provides an accurate means of comparing experimental results with the predictions of kinetic magnetohydrodynamics. The method can be extended to include self consistent modification of the particle orbits by the mode, and hence the full nonlinear dynamics of the coupled system

  3. Role of particle-hole symmetry in mirror energy difference

    International Nuclear Information System (INIS)

    Kumar, V.; Kumar, S.; Hasan, Z.; Kumar, D.; Koranga, B.S.; Rohitash; Singh, D.; Negi, D.; Angus, L.

    2011-01-01

    Charge symmetry between protons and neutrons means that they can be viewed as two states of the same particle, the nucleon, characterized by different projections of the isospin quantum number. In the hypothesis of charge symmetry expected identical behaviour of excited states of two nuclei with the same total number of nucleons (isobaric nuclei). The nuclei with magic number are considered to be spherical. When the number of particles/holes increase, the nucleus try towards more deformed upto mid-shell. It shows symmetry between particles and holes towards the deformation. The hypothesis of Particle-hole symmetry expected identical behaviour of excited states of two nuclei close to magic number. It is worthwhile to examine the shape of mirror energy difference (MED) close to magic number nuclei, which will also an example of particle-hole symmetry

  4. The low-energy frontier of particle physics

    International Nuclear Information System (INIS)

    Jaeckel, Joerg

    2010-02-01

    Most embeddings of the Standard Model into a more unified theory, in particular the ones based on supergravity or superstrings, predict the existence of a hidden sector of particles which have only very weak interactions with the visible sector Standard Model particles. Some of these exotic particle candidates (such as e.g. ''axions'', ''axion-like particles'' and ''hidden U(1) gauge bosons'') may be very light, with masses in the sub-eV range, and have very weak interactions with photons. Correspondingly, these very weakly interacting sub-eV particles (WISPs) may lead to observable effects in experiments (as well as in astrophysical and cosmological observations) searching for light shining through a wall, for changes in laser polarisation, for non-linear processes in large electromagnetic fields and for deviations from Coulomb's law. We present the physics case and a status report of this emerging low-energy frontier of fundamental physics. (orig.)

  5. A massive cryogenic particle detector with good energy resolution

    International Nuclear Information System (INIS)

    Ferger, P.; Colling, P.; Cooper, S.; Dummer, D.; Frank, M.; Nagel, U.; Nucciotti, A.; Proebst, F.; Seidel, W.

    1993-12-01

    Massive cryogenic particle detectors are being developed for use in a search for dark matter particles. Results with a 31 g sapphire crystal and a superconducting phase transition thermometer operated at 44 mK are presented. The observed signal includes a fast component which is significantly larger than the expected thermal pulse. The energy resolution is 210 eV (FWHM) for 6 keV X-rays. (orig.)

  6. Particles and energy fluxes from a conformal field theory perspective

    International Nuclear Information System (INIS)

    Fabbri, A.; Navarro-Salas, J.; Olmo, G.J.

    2004-01-01

    We analyze the creation of particles in two dimensions under the action of conformal transformations. We focus our attention on Mobius transformations and compare the usual approach, based on the Bogoliubov coefficients, with an alternative but equivalent viewpoint based on correlation functions. In the latter approach the absence of particle production under full Mobius transformations is manifest. Moreover, we give examples, using the moving-mirror analogy, to illustrate the close relation between the production of quanta and energy

  7. Azimuthal asymmetry of slow particles in high energy nuclear interaction

    International Nuclear Information System (INIS)

    Sarkar, Subir; Goswami, T.D.

    2002-01-01

    An asymmetry in the angular distribution of slow particles in the azimuthal plane has been observed during high energy nuclear disintegration of photo emulsion nuclei exposed to 1.8 GeV/c k - and 20 GeV/c protons. The mechanism of disintegration is not in accordance with the cascade-evaporation model, which is based on isotropic emission of slow particles. Deviation from isotropy indicates that some of the slow particles might be emitted well before the thermal equilibrium is reached in the disintegrating system. (author)

  8. Energy exchange in systems of particles with nonreciprocal interaction

    Energy Technology Data Exchange (ETDEWEB)

    Vaulina, O. S.; Lisina, I. I., E-mail: Irina.Lisina@mail.ru; Lisin, E. A. [Russian Academy of Sciences, Joint Institute for High Temperatures (Russian Federation)

    2015-10-15

    A model is proposed to describe the sources of additional kinetic energy and its redistribution in systems of particles with a nonreciprocal interaction. The proposed model is shown to explain the qualitative specific features of the dust particle dynamics in the sheath region of an RF discharge. Prominence is given to the systems of particles with a quasi-dipole–dipole interaction, which is similar to the interaction induced by the ion focusing effects that occur in experiments on a laboratory dusty plasma, and with the shadow interaction caused by thermophoretic forces and Le Sage’s forces.

  9. [Studies of elementary particles and high energy phenomena: [Progress report

    International Nuclear Information System (INIS)

    Cumalat, J.P.

    1989-01-01

    The scope of work under this contract is unclassified and shall consist of experimental, theoretical, and phenomenological research on the fundamental properties of high energy subnuclear particles at the Fermi National Accelerator Laboratory, the Stanford Linear Accelerator Center, the Los Alamos National Laboratory, the SSC laboratory, and the University of Colorado with emphasis on photon beam experiments, electron-positron interactions, charmed particles, production of new vector bosons, advanced data acquisition systems, two photon physics, particle lifetimes, supergravity, supersymmetry, superstrings, quantum chromodynamics, nonequilibrium statistical mechanics, cosmology, phase transitions, lattice gauge theory, anomaly-free theories, gravity and instrumentation development. These topics are covered in this report

  10. Neutron flux density and secondary-particle energy spectra at the 184-inch synchrocyclotron medical facility

    International Nuclear Information System (INIS)

    Smith, A.R.; Schimmerling, W.; Henson, A.M.; Kanstein, L.L.; McCaslin, J.B.; Stephens, L.D.; Thomas, R.H.; Ozawa, J.; Yeater, F.W.

    1978-07-01

    Helium ions, with an energy of 920 MeV, produced by the 184-inch synchrocyclotron of the Lawrence Berkeley Laboratory are now being used in a pilot series to determine their efficacy in the treatment of tumors of large volume. The techniques for production of the large uniform radiation fields required for these treatments involve the use of beam-limiting collimators and energy degraders. Interaction of the primary beam with these beam components produces secondary charged particles and neutrons. The sources of neutron production in the beam transport system of the alpha-particle beam have been identified and their magnitudes have been determined. Measurements with activation detectors and pulse counters of differing energy responses have been used to determine secondary particle spectra at various locations on the patient table. These spectra are compared to a calculation of neutron production based on best estimates derived from published cross sections. Agreement between the calculated spectra and those derived from experimental measurements is obtained (at the 10 to 20% level) when the presence of charged particles is taken into account. The adsorbed dose in soft tissue is not very sensitive to the shape of the incident neutron energy spectrum, and the values obtained from unfolding the experimental measurements agree with the values obtained from the calculated spectra within the estimated uncertainty of +-25%. These values are about 3 x 10 -3 rad on the beam axis and about 1 x 10 -3 rad at 20 cm or more from the beam axis, per rad deposited by the incident alpha-particle beam. Estimates of upper limit dose to the lens of the eye and red bone marrow are approximately 10 rad and approximately 1 rad, respectively, for a typical treatment plan. The absorbed dose to the lens of the eye is thus well below the threshold value for cataractogenesis estimated for fission neutrons. An upper limit for the risk of leukemia is estimated to be approximately 0.04%

  11. Real-time energy detector for relativistic charged particles

    International Nuclear Information System (INIS)

    Piestrup, A.

    1988-01-01

    The objective of the research is to investigate the use of coherent transition radiation to measure the energy of ultra-relativistic charged particles. The research has possible applications for the detection and identification of these particles. It can also be used for beam diagnostics for both high-repetition-rate and single-pulse, high-current accelerators. The device is low cost and can operate in situ while causing little or no perturbation to the beam. Three such coherent radiators have been constructed and tested at two accelerators using electron beam energies ranging from 50 to 228 MeV. Soft x-ray emission (1 keV to 4 keV) was emitted in a circularly symmetrical annulus with half-angle divergence of 2.5 to 9.0 mr. By selecting foil thickness and spacing, it is possible to design radiators whose angle of emission varies radically over a range of charge-particle energies

  12. Energy deposition and GDR emission in inelastic alpha particle scattering

    CERN Document Server

    Viesti, G; Fabris, D; Nebbia, G; Cinausero, M; Fioretto, E; Napoli, D R; Prete, G; Hagel, K; Natowitz, J B; Wada, R; Gonthier, P; Majka, Z; Alfarro, R; Zhao, Y; Mdeiwayeh, N; Ho, T

    1999-01-01

    Neutron fold distributions measured for the reaction sup 2 sup 0 sup 9 Bi(alpha,alpha') at 240 MeV have been analyzed with the help of Statistical Model calculations to determine the distribution of excitation energy in the primary target fragments as a function of the projectile energy loss, EL. Results show that the distributions in excitation energy feature a plateau which extends from the kinematical limit E sub x =EL to very small excitations, suggesting a variety of interactions of the beam particles with the target nucleus. Requiring an additional coincidence with a light charged particle leads to selection of a significant higher average excitation energy. This effect is extrapolated to explore results of previous GDR decay measurements in the case of a sup 2 sup 0 sup 8 Pb target. Corrections of derived GDR parameters due to the partial transfer of excitation energy are suggested.

  13. A facility for low energy charged particle induced reaction studies

    International Nuclear Information System (INIS)

    Vilaithong, T.; Singkarat, S.; Yu, L.D.; Intarasiri, S.; Tippawan, U.

    2000-01-01

    In Chiang Mai, a highly stable low energy ion accelerator (0 - 350 kV) facility is being established. A subnano-second pulsing system will be incorporated into the beam transport line. The detecting system will consist of a time-of-flight charged particle spectrometer and a high resolution gamma-ray system. The new facility will be used in the studies of low energy heavy ion backscattering and charged particle induced cross section measurement in the interests of material characterization and nucleosynthesis. (author)

  14. Low energy neutral particle fluxes in the JET divertor

    International Nuclear Information System (INIS)

    Reichle, R.; Horton, L.D.; Ingesson, L.C.; Jaeckel, H.J.; McCormick, G.K.; Loarte, A.; Simonini, R.; Stamp, M.F.

    1997-01-01

    First measurements are presented of the total power loss through neutral particles and their average energy in the JET divertor. The method used distinguishes between the heat flux and the electromagnetic radiation on bolometers. This is done by comparing measurements from inside the divertor either with opposite lines of sight or with a tomographic reconstruction of the radiation. The typical value of the total power loss in the divertor through neutrals is about 1 MW. The average energy of the neutral particles at the inner divertor leg is 1.5-3 eV when detachment is in progress, which agrees with EDGE2D/NIMBUS modelling. (orig.)

  15. Concept and design of charged particle optics using energy Fourier plane collimation

    Science.gov (United States)

    Yang, Guojun; Wei, Tao; Zhang, Zhuo; He, Xiaozhong; Zhang, Xiaoding; Li, Yiding; Shi, Jinshui

    2014-09-01

    Charged particle radiography has become a promising new approach in the field of transmission radiography because of the invention of the magnetic imaging lens. The using of the imaging lens makes it possible for thick objects to get significantly improved transmission radiography. Currently, the conventional charged particle radiography only uses the information of the flux attenuation and the angular scattering of the transmitted particles to determine the properties of the sample. However, the energy loss of the incident particles introduced by ionizations throughout the object limits the spatial resolution of the image because of the chromatic blur. In this paper a new concept of imaging lens that uses the information of the energy loss is proposed. With a specially designed imaging lens, the information of the energy loss could result in apparent contrast in the final image. This design procedure of the energy loss imaging lens is presented, and a preliminary design is verified by numerical simulations. Experimental demonstration is also expected on a cyclotron at the Institute of Fluid Physics, CAEP.

  16. Concept and design of charged particle optics using energy Fourier plane collimation

    Directory of Open Access Journals (Sweden)

    Guojun Yang

    2014-09-01

    Full Text Available Charged particle radiography has become a promising new approach in the field of transmission radiography because of the invention of the magnetic imaging lens. The using of the imaging lens makes it possible for thick objects to get significantly improved transmission radiography. Currently, the conventional charged particle radiography only uses the information of the flux attenuation and the angular scattering of the transmitted particles to determine the properties of the sample. However, the energy loss of the incident particles introduced by ionizations throughout the object limits the spatial resolution of the image because of the chromatic blur. In this paper a new concept of imaging lens that uses the information of the energy loss is proposed. With a specially designed imaging lens, the information of the energy loss could result in apparent contrast in the final image. This design procedure of the energy loss imaging lens is presented, and a preliminary design is verified by numerical simulations. Experimental demonstration is also expected on a cyclotron at the Institute of Fluid Physics, CAEP.

  17. Neutron emission cross sections on 93Nb at 20 MeV incident energy

    International Nuclear Information System (INIS)

    Marcinkowski, A.; Kielan, D.

    1991-01-01

    Over the last years fully quantum-mechanical theories of nuclear reactions have been developed that provide, at least in principle, parameter-free methods of calculating double-differential continuum cross sections. The DWBA-based theory of direct processes to the continuum was derived by Tamura et al. The statistical theory of Feshback, Kerman and Koonin (FKK) introduced two reaction types in parallel as complementary mechanisms contributing to the preequilibrium decay. The multistep compound mechanism (MSC) results in symmetric angular distributions of the emitted particles, whereas the multistep direct mechanism (MSD) gives rise to the forward-peaked angular distributions. The theories of the MSC reactions differ in that the FKK theory incorporates the ''never come back'' hypothesis, which allowed the formulation of an applicable model that was successfully used in practical calculations. On the other hand the FKK theory of the MSD reactions differs conceptually from the theory of Tamura et al. and from the more general theory developed most recently by Nishioka et al. The latter theories were shown to be founded upon a postulated chaos located in the residual nucleus. In contrast, the theory of FKK assumes a chaotic interaction of the continuum particle to be emitted with the residual nucleus. The continuum or leading-particle statistics of the FKK theory results in the simple, convolution like, MSD cross section formula, which facilitates numerical calculations. Nevertheless two-step statistical DWBA calculations have been also performed. This paper extends the application of the FKK theory to the 93 Nb(n,xn) reaction at 20 MeV incident energy. (author). 14 refs, 1 fig

  18. Energy in elastic fiber embedded in elastic matrix containing incident SH wave

    Science.gov (United States)

    Williams, James H., Jr.; Nagem, Raymond J.

    1989-01-01

    A single elastic fiber embedded in an infinite elastic matrix is considered. An incident plane SH wave is assumed in the infinite matrix, and an expression is derived for the total energy in the fiber due to the incident SH wave. A nondimensional form of the fiber energy is plotted as a function of the nondimensional wavenumber of the SH wave. It is shown that the fiber energy attains maximum values at specific values of the wavenumber of the incident wave. The results obtained here are interpreted in the context of phenomena observed in acousto-ultrasonic experiments on fiber reinforced composite materials.

  19. Energy loss of charged particles to molecular gas targets

    International Nuclear Information System (INIS)

    Sigmund, P.

    1976-01-01

    The energy loss spectrum of fast charged particles penetrating a dilute molecular gas target has been analysed theoretically, with a homogeneous gas mixture in the state of complete dissociation as a reference standard. It is shown that the geometrical structure of molecules causes the energy-loss straggling and higher moments over the energy-loss spectrum to be greater than the corresponding quantities for a completely dissociated gas of equal composition. Such deviations from additivity are shown to be most pronounced at energies around the stopping-power maximum. There is found supporting evidence in the experimental literature. (Auth.)

  20. Single Particle energy levels in ODD-A Nuclei

    International Nuclear Information System (INIS)

    Lasijo, R.S.

    1997-01-01

    Singe particle energies for atomic nuclei with odd-A number of nucleons, i.e. nuclei possessing odd number of protons or odd number of neutrons, were calculated based on Nilsson's theory, and then the diagrams were made. the energy diagram is in the from of plot of energies as function of deformations, entities identifying the deviations from the spherical shape. The energy calculations were done using FORTRAN 77 language of PC (Personal Computer) version with Microsoft Fortran Power Station compiler, which was then combined with WORD version 6.0 and EXCEL version 5.0 of WINDOWS WORKGROUP to make the plot

  1. Particle Physics at the Cosmic, Intensity, and Energy Frontiers

    Energy Technology Data Exchange (ETDEWEB)

    Essig, Rouven

    2018-04-06

    Major efforts at the Intensity, Cosmic, and Energy frontiers of particle physics are rapidly furthering our understanding of the fundamental constituents of Nature and their interactions. The overall objectives of this research project are (1) to interpret and develop the theoretical implications of the data collected at these frontiers and (2) to provide the theoretical motivation, basis, and ideas for new experiments and for new analyses of experimental data. Within the Intensity Frontier, an experimental search for a new force mediated by a GeV-scale gauge boson will be carried out with the $A'$ Experiment (APEX) and the Heavy Photon Search (HPS), both at Jefferson Laboratory. Within the Cosmic Frontier, contributions are planned to the search for dark matter particles with the Fermi Gamma-ray Space Telescope and other instruments. A detailed exploration will also be performed of new direct detection strategies for dark matter particles with sub-GeV masses to facilitate the development of new experiments. In addition, the theoretical implications of existing and future dark matter-related anomalies will be examined. Within the Energy Frontier, the implications of the data from the Large Hadron Collider will be investigated. Novel search strategies will be developed to aid the search for new phenomena not described by the Standard Model of particle physics. By combining insights from all three particle physics frontiers, this research aims to increase our understanding of fundamental particle physics.

  2. The Phobos low energy telescope charged particle experiment

    Energy Technology Data Exchange (ETDEWEB)

    Marsden, R.G.; Henrion, J.P.G.; Wenzel, K.P. (European Space Agency, Noordwijk (Netherlands). Space Science Dept.); Afonin, V.V. (AN SSSR, Moscow (USSR). Inst. Kosmicheskikh Issledovanij); Balazs, A.; Erdoes, G.; Rusznyak, P.; Somogyi, A.; Szalai, S.; Varga, A.; Varhalmi, L. (Hungarian Academy of Sciences, Budapest (Hungary). Central Research Inst. for Physics); Richter, A.K.; Witte, M. (Max-Planck-Institut fuer Aeronomie, Katlenburg-Lindau (Germany, F.R.))

    1990-05-01

    The Low Energy Telescope (LET) experiment on board the Phobos 1 and 2 spacecraft measures the flux, energy spectra and elemental composition of solar energetic particles and cosmic ray nuclei from hydrogen up to iron in the energy range {proportional to}1 to {proportional to}75 MeV/n. The LET sensor system comprises a double dE/dX vs E solid-state detector telescope surrounded by a cylindrical plastic scintillator anticoincidence shield, and the instrument is equipped with a comprehensive particle identifier and event priority system that enables rare nuclei to be analysed in preference to the more common species. Isotope separation for light nuclei such as He is also achieved. The sensor is mounted on a rotating platform to enable coarse anisotropy measurements of low energy protons to be made. (orig.).

  3. Direct reactions induced by 16O on 208Pb at high incident energy

    International Nuclear Information System (INIS)

    Mermaz, M.C.

    1978-01-01

    Direct reactions induced by 16 O mainly on 208 Pb at 20 MeV/nucleon are reviewed. The quasi-elastic transfer reaction, such as one-proton and one-neutron transfer respectively leading to 209 Bi and 209 Pb single-particle-states, is first discussed, the fragmentation of 16 O projectile on heavy targets is then envisaged. The one-nucleon transfer can be described within the framework of one-step processes using the DWBA formalism to calculate the cross sections. At high incident energy (312.6 MeV), transfer reactions involving nucleons from the deeper 1p 3/2 orbit of 16 O are kinematically favoured and well observed. At 20 MeV/A and above, a large part of the reaction cross sections seems to be due to the fragmentation of the projectile; more especially, an abrasion-ablation model have to be used in order to explain the general trend of the data (energy spectra and angular distribution)

  4. Laser focusing of high-energy charged-particle beams

    International Nuclear Information System (INIS)

    Channell, P.J.

    1986-01-01

    It is shown that laser focusing of high-energy charged-particle beams using the inverse Cherenkov effect is well suited for applications with large linear colliders. Very high gradient (>0.5 MG/cm) lenses result that can be added sequentially without AG cancellation. These lenses are swell understood, have small geometric aberrations, and offer the possibility of correlating phase and energy aberrations to produce an achromatic final focus

  5. Neutrino fluxes produced by high energy solar flare particles

    International Nuclear Information System (INIS)

    Kolomeets, E.V.; Shmonin, V.L.

    1975-01-01

    In this work the calculated differential energy spectra of neutrinos poduced by high energy protons accelerated during 'small' solar flares are presented. The muon flux produced by neutrino interactions with the matter at large depths under the ground is calculated. The obtained flux of muons for the total number of solar flare accelerated protons of 10 28 - 10 32 is within 10 9 - 10 13 particles/cm 2 X s x ster. (orig.) [de

  6. Energy and particle core transport in tokamaks and stellarators compared

    Energy Technology Data Exchange (ETDEWEB)

    Beurskens, Marc; Angioni, Clemente; Beidler, Craig; Dinklage, Andreas; Fuchert, Golo; Hirsch, Matthias; Puetterich, Thomas; Wolf, Robert [Max-Planck-Institut fuer Plasmaphysik, Greifswald/Garching (Germany)

    2016-07-01

    The paper discusses expectations for core transport in the Wendelstein 7-X stellarator (W7-X) and presents a comparison to tokamaks. In tokamaks, the neoclassical trapped-particle-driven losses are small and turbulence dominates the energy and particle transport. At reactor relevant low collisionality, the heat transport is limited by ion temperature gradient limited turbulence, clamping the temperature gradient. The particle transport is set by an anomalous inward pinch, yielding peaked profiles. A strong edge pedestal adds to the good confinement properties. In traditional stellarators the 3D geometry cause increased trapped orbit losses. At reactor relevant low collisionality and high temperatures, these neoclassical losses would be well above the turbulent transport losses. The W7-X design minimizes neoclassical losses and turbulent transport can become dominant. Moreover, the separation of regions of bad curvature and that of trapped particle orbits in W7-X may have favourable implications on the turbulent electron heat transport. The neoclassical particle thermodiffusion is outward. Without core particle sources the density profile is flat or even hollow. The presence of a turbulence driven inward anomalous particle pinch in W7-X (like in tokamaks) is an open topic of research.

  7. Fly ash particles spheroidization using low temperature plasma energy

    Science.gov (United States)

    Shekhovtsov, V. V.; Volokitin, O. G.; Kondratyuk, A. A.; Vitske, R. E.

    2016-11-01

    The paper presents the investigations on producing spherical particles 65-110 μm in size using the energy of low temperature plasma (LTP). These particles are based on flow ash produced by the thermal power plant in Seversk, Tomsk region, Russia. The obtained spherical particles have no defects and are characterized by a smooth exterior surface. The test bench is designed to produce these particles. With due regard for plasma temperature field distribution, it is shown that the transition of fly ash particles to a state of viscous flow occurs at 20 mm distance from the plasma jet. The X-ray phase analysis is carried out for the both original state of fly ash powders and the particles obtained. This analysis shows that fly ash contains 56.23 wt.% SiO2; 20.61 wt.% Al2O3 and 17.55 wt.% Fe2O3 phases that mostly contribute to the integral (experimental) intensity of the diffraction maximum. The LTP treatment results in a complex redistribution of the amorphous phase amount in the obtained spherical particles, including the reduction of O2Si, phase, increase of O22Al20 and Fe2O3 phases and change in Al, O density of O22Al20 chemical unit cell.

  8. Consistent energy barrier distributions in magnetic particle chains

    International Nuclear Information System (INIS)

    Laslett, O.; Ruta, S.; Chantrell, R.W.; Barker, J.; Friedman, G.; Hovorka, O.

    2016-01-01

    We investigate long-time thermal activation behaviour in magnetic particle chains of variable length. Chains are modelled as Stoner–Wohlfarth particles coupled by dipolar interactions. Thermal activation is described as a hopping process over a multidimensional energy landscape using the discrete orientation model limit of the Landau–Lifshitz–Gilbert dynamics. The underlying master equation is solved by diagonalising the associated transition matrix, which allows the evaluation of distributions of time scales of intrinsic thermal activation modes and their energy representation. It is shown that as a result of the interaction dependence of these distributions, increasing the particle chain length can lead to acceleration or deceleration of the overall relaxation process depending on the initialisation procedure.

  9. The inelastic scattering of medium energy α particles

    International Nuclear Information System (INIS)

    Crut, M.

    1960-01-01

    The aim of this work is to find out what are the properties of the so-called 'anomalous states' in medium weight nuclei. These states preferentially excited in the inelastic scattering of medium energy charged particles have an excitation energy at about 4 MeV for nuclei with Z ≤ 29 and in the range 2-3 MeV for high Z nuclei. From a combination of angular distribution data in the elastic and inelastic scattering of 30 MeV α particles, and correlation data between inelastic α particles and deexcitation γ rays, we show that for even-even nuclei, we can attribute spin 3 and parity minus to these 'anomalous states'. This is quite in agreement with the interpretation of these levels suggested by Lane as due to collective octupole oscillations. We give a resume of the theories used in the analysis of the data and a description of the experimental set-up. (author) [fr

  10. Medical radiation dosimetry theory of charged particle collision energy loss

    CERN Document Server

    McParland, Brian J

    2014-01-01

    Accurate radiation dosimetry is a requirement of radiation oncology, diagnostic radiology and nuclear medicine. It is necessary so as to satisfy the needs of patient safety, therapeutic and diagnostic optimisation, and retrospective epidemiological studies of the biological effects resulting from low absorbed doses of ionising radiation. The radiation absorbed dose received by the patient is the ultimate consequence of the transfer of kinetic energy through collisions between energetic charged particles and atoms of the tissue being traversed. Thus, the ability of the medical physicist to both measure and calculate accurately patient dosimetry demands a deep understanding of the physics of charged particle interactions with matter. Interestingly, the physics of charged particle energy loss has an almost exclusively theoretical basis, thus necessitating an advanced theoretical understanding of the subject in order to apply it appropriately to the clinical regime. ​ Each year, about one-third of the worl...

  11. Mass, Momentum and Kinetic Energy of a Relativistic Particle

    Science.gov (United States)

    Zanchini, Enzo

    2010-01-01

    A rigorous definition of mass in special relativity, proposed in a recent paper, is recalled and employed to obtain simple and rigorous deductions of the expressions of momentum and kinetic energy for a relativistic particle. The whole logical framework appears as the natural extension of the classical one. Only the first, second and third laws of…

  12. Energy dissipation and charged particle production in heavy ion collisions

    International Nuclear Information System (INIS)

    Mishra, Aditya Nath; Sahoo, Raghunath; Sarkisyan Edward, K.G.; )

    2013-01-01

    In this paper, we use a model combining the constituent quark picture with Landau relativistic hydrodynamics. Within this model, the secondary particle production in nucleus-nucleus or nucleon-nucleon (p-barp/pp) collisions is basically driven by the amount of the initial effective energy deposited by participants (quarks or nucleons) into the Lorentz contracted overlap region

  13. Detection systems for high energy particle producing gaseous ionization

    International Nuclear Information System (INIS)

    Martinez, L.; Duran, I.

    1985-01-01

    This report contains a review on the most used detectors based on the collection of the ionization produced by high energy particles: proportional counters, multiwire proportional chambers, Geiger-Muller counters and drift chambers. In six sections, the fundamental principles, the field configuration and useful gas mixtures, are discussed, most relevant devices are reported along 90 pages with 98 references. (Author) 98 refs

  14. Detection systems for high energy particle producing gaseous ionization

    International Nuclear Information System (INIS)

    Duran, I.; Martinez, L.

    1985-01-01

    This report contains a review on the most used detectors based on the collection of the ionization produced by high energy particles: proportional counters, multiwire proportional chambers, Geiger-Mueller counters and drift chambers. In six sections, the fundamental principles, the field configuration and useful gas mixtures are discussed, most relevant devices are reported. (author)

  15. Extreme Energy Particle Astrophysics with ANITA-V

    Science.gov (United States)

    Wissel, Stephanie

    This proposal is in collaboration with Peter Gorham at the University of Hawaii, who is the PI of the lead proposal. Co-I Wissel and her group at California Polytechnic State University (Cal Poly) will be responsible for calibration equipment upgrades, calibration equipment, and deployment of the calibration system. The Cal Poly group is planning to provide calibration hardware and software products in support of the analysis of ANITAV data in search of ultra high-energy (UHE) neutrinos and cosmic rays. Wissel (now at Cal Poly, a new collaborating institution for ANITA-5) brings significant experience in the detection of high-energy and ultra-high energy particles to the collaboration, leveraging her thirteen years of experience in particle astrophysics and previous work on ANITA-III and ANITA-IV.

  16. Gyrokinetic theory for particle and energy transport in fusion plasmas

    Science.gov (United States)

    Falessi, Matteo Valerio; Zonca, Fulvio

    2018-03-01

    A set of equations is derived describing the macroscopic transport of particles and energy in a thermonuclear plasma on the energy confinement time. The equations thus derived allow studying collisional and turbulent transport self-consistently, retaining the effect of magnetic field geometry without postulating any scale separation between the reference state and fluctuations. Previously, assuming scale separation, transport equations have been derived from kinetic equations by means of multiple-scale perturbation analysis and spatio-temporal averaging. In this work, the evolution equations for the moments of the distribution function are obtained following the standard approach; meanwhile, gyrokinetic theory has been used to explicitly express the fluctuation induced fluxes. In this way, equations for the transport of particles and energy up to the transport time scale can be derived using standard first order gyrokinetics.

  17. Two-particle correlations at FNAL and ISR energies

    International Nuclear Information System (INIS)

    Darriulat, P.

    1975-01-01

    Some recent experimental results concerning the cluster structure of hadronic final states at high incident energies are reviewed. Results of experiments on angular correlations, both rapidity correlations and joint azimuth-rapidity correlations, in the central region, are discussed. Recent evidence for local compensation of charges and new data on resonance production are reviewed. Leading and high transverse momentum clusters, in as much as they may somehow be related to central clusters, are dealt with briefly. (U.K.)

  18. Energy loss of particles in dense matter - calorimetry

    International Nuclear Information System (INIS)

    Wigmans, R.

    1987-08-01

    In the last decade, a class of detectors gradually have become more and more important in experimental particle physics. They are called calorimeters, or total absorption detectors. Basically a calorimeter is a block of matter, in which the particle to be measured interacts, and deposits all its energy in the form of a shower of decreasingly lower-energy particles. The block is made such that certain (usually small and hopefully constant) fraction of the initial particle energy is transformed in a measurable signal (light, electrical charge). This lecture mainly deals with sampling calorimeters but in section 2 also fully sensitive devices are briefly treated. In this section calorimeters for detecting electromagnetic showers are discussed. The physics processes relevant to em shower development are examined, and the factors that limit the performance of em calorimeters. Section 3 is devoted to readout techniques for sampling calorimeters. In sections 4-7 hadron calorimeters are discussed. The physics processes relevant to hadron shower development, their consequences for the calorimeter signals and the possibility for optimizing the performance of hadron calorimeters are examined. In section 8 an outlook for future development is given. 31 refs.; 48 figs

  19. Generating heavy particles with energy and momentum conservation

    Science.gov (United States)

    Mereš, Michal; Melo, Ivan; Tomášik, Boris; Balek, Vladimír; Černý, Vladimír

    2011-12-01

    We propose a novel algorithm, called REGGAE, for the generation of momenta of a given sample of particle masses, evenly distributed in Lorentz-invariant phase space and obeying energy and momentum conservation. In comparison to other existing algorithms, REGGAE is designed for the use in multiparticle production in hadronic and nuclear collisions where many hadrons are produced and a large part of the available energy is stored in the form of their masses. The algorithm uses a loop simulating multiple collisions which lead to production of configurations with reasonably large weights. Program summaryProgram title: REGGAE (REscattering-after-Genbod GenerAtor of Events) Catalogue identifier: AEJR_v1_0 Program summary URL:http://cpc.cs.qub.ac.uk/summaries/AEJR_v1_0.html Program obtainable from: CPC Program Library, Queen's University, Belfast, N. Ireland Licensing provisions: Standard CPC licence, http://cpc.cs.qub.ac.uk/licence/licence.html No. of lines in distributed program, including test data, etc.: 1523 No. of bytes in distributed program, including test data, etc.: 9608 Distribution format: tar.gz Programming language: C++ Computer: PC Pentium 4, though no particular tuning for this machine was performed. Operating system: Originally designed on Linux PC with g++, but it has been compiled and ran successfully on OS X with g++ and MS Windows with Microsoft Visual C++ 2008 Express Edition, as well. RAM: This depends on the number of particles which are generated. For 10 particles like in the attached example it requires about 120 kB. Classification: 11.2 Nature of problem: The task is to generate momenta of a sample of particles with given masses which obey energy and momentum conservation. Generated samples should be evenly distributed in the available Lorentz-invariant phase space. Solution method: In general, the algorithm works in two steps. First, all momenta are generated with the GENBOD algorithm. There, particle production is modeled as a sequence of two

  20. Plasma focusing and diagnosis of high energy particle beams

    International Nuclear Information System (INIS)

    Chen, Pisin.

    1990-09-01

    Various novel concepts of focusing and diagnosis of high energy charged particle beams, based on the interaction between the relativistic particle beam and the plasma, are reviewed. This includes overdense thin plasma lenses, and (underdense) adiabatic plasma lens, and two beam size monitor concepts. In addition, we introduce another mechanism for measuring flat beams based on the impulse received by heavy ions in an underdense plasma. Theoretical investigations show promise of focusing and diagnosing beams down to sizes where conventional methods are not possible to provide. 21 refs

  1. Ultrahigh energy cosmic rays and new particle physics

    CERN Document Server

    Kachelriess, M.

    2001-02-28

    The current status of the ultrahigh energy cosmic ray (UHE CR) enigma and several proposed solutions involving particle physics beyond the standard model are discussed. Emphasis is given to top--down models, and as a main example, supermassive dark matter as galactic source for UHE CR and the status of its experimental signatures (galactic anisotropy, chemical composition and clustering) is reviewed. Then different approaches to calculate fragmentation spectra of supermassive particles are discussed. Finally, it is argued that UHE neutrinos cannot be - neither directly or indirectly - responsible for the observed vertical air showers.

  2. Predictions of Quantum Molecular Dynamical Model between incident energy 50 and 1000 MeV/Nucleon

    Directory of Open Access Journals (Sweden)

    Kumar Sanjeev

    2015-01-01

    Full Text Available In the present work, the Quantum Molecular Dynamical (QMD model is summarized as a useful tool for the incident energy range of 50 to 1000 MeV/nucleon in heavy-ion collisions. The model has reproduced the experimental results of various collaborations such as ALADIN, INDRA, PLASTIC BALL and FOPI upto a high level of accuracy for the phenomena like multifragmentation, collective flow as well as elliptical flow in the above prescribed energy range. The efforts are further in the direction to predict the symmetry energy in the wide incident energy range.

  3. Effects of incident cluster size, substrate temperature, and incident energy on bombardment of Ni clusters onto Cu (0 0 1) surface studied using molecular dynamics simulation

    International Nuclear Information System (INIS)

    Lin, Shiang-Jiun; Wu, Cheng-Da; Fang, Te-Hua; Chen, Guan-Hung

    2012-01-01

    The bombardment process of a Ni cluster onto a Cu (0 0 1) surface is studied using molecular dynamics (MD) simulations based on the tight-binding second-moment approximation (TB-SMA) many-body potential. The effects of incident cluster size, substrate temperature, and incident energy are evaluated in terms of molecular trajectories, kinetic energy, stress, self-diffusion coefficient, and sputtering yield. The simulation results clearly show that the penetration depth and Cu surface damage increase with increasing incident cluster size for a given incident energy per atom. The self-diffusion coefficient and the penetration depth of a cluster significantly increase with increasing substrate temperature. An incident cluster can be scattered into molecules or atoms that become embedded in the surface after incidence. When the incident energy is increased, the number of volcano-like defects and the penetration depth increase. A high sputtering yield can be obtained by increasing the incident energy at high temperature. The sputtering yield significantly increases with cluster size when the incident energy is above 5 eV/atom.

  4. High energy particles with negative and positive energies in the vicinity of black holes

    Science.gov (United States)

    Grib, A. A.; Pavlov, Yu. V.

    2014-07-01

    It is shown that the energy in the centre of mass frame of two colliding particles in free fall at any point of the ergosphere of the rotating black hole can grow without limit for fixed energy values of particles on infinity. The effect takes place for large negative values of the angular momentum of one of the particles. It occurs that the geodesics with negative energy in equatorial plane of rotating black holes cannot originate or terminate inside the ergosphere. Their length is always finite and this leads to conclusion that they must originate and terminate inside the gravitational radius of the ergosphere. The energy in the centre of mass frame of one particle falling into the gravitational radius and the other arriving from the area inside it is growing without limit on the horizon.

  5. High-energy particles associated with solar flares

    International Nuclear Information System (INIS)

    Sakurai, K.; Klimas, A.J.

    1974-05-01

    High energy particles, the so-called solar cosmic rays, are often generated in association with solar flares, and then emitted into interplanetary space. These particles, consisting of electrons, protons, and other heavier nuclei, including the iron-group, are accelerated in the vicinity of the flare. By studying the temporal and spatial variation of these particles near the earth's orbit, their storage and release mechanisms in the solar corona and their propagation mechanism can be understood. The details of the nuclear composition and the rigidity spectrum for each nuclear component of the solar cosmic rays are important for investigating the acceleration mechanism in solar flares. The timing and efficiency of the acceleration process can also be investigated by using this information. These problems are described in some detail by using observational results on solar cosmic rays and associated phenomena. (U.S.)

  6. A practical guide to modern high energy particle accelerators

    International Nuclear Information System (INIS)

    Holmes, S.D.

    1987-10-01

    The purpose of these lectures is to convey an understanding of how particle accelerators work and why they look the way they do. The approach taken is physically intuitive rather than mathematically rigorous. The emphasis is on the description of proton circular accelerators and colliders. Linear accelerators are mentioned only in passing as sources of protons for higher energy rings. Electron accelerators/storage rings and antiproton sources are discussed only by way of brief descriptions of the features which distinguish them from proton accelerators. The basics of how generic accelerators work are discussed, focusing on descriptions of what sets the overall scale, single particle dynamics and stability, and descriptions of the phase space of the particle beam, the information thus presented is then used to go through the exercise of designing a Superconducting Super Collider

  7. Simulation calculation for the energy deposition profile and the transmission fraction of intense pulsed electron beam at various incident angles

    International Nuclear Information System (INIS)

    Yang Hailiang; Qiu Aici; Zhang Jiasheng; Huang Jianjun; Sun Jianfeng

    2002-01-01

    The incident angles have a heavy effect on the intense pulsed electron beam energy deposition profile, energy deposition fraction and beam current transmission fraction in material. The author presents electron beam energy deposition profile and energy deposition fraction versus electron energy (0.5-2.0 MeV), at various incident angles for three aluminum targets of various thickness via theoretical calculation. The intense pulsed electron beam current transmission fractions versus electron energy (0.4-1.4 MeV) at various incident angles for three thickness of carbon targets were also theoretically calculated. The calculation results indicate that the deposition energy in unit mass of material surface layer increase with the rise of electron beam incident angle, and electron beam with low incident angle (closer to normal incident angle) penetrates deeper into the target material. The electron beams deposit more energy in unit mass of material surface layer at 60 degree-70 degree incident angle

  8. Exchange-correlation energy from pairing matrix fluctuation and the particle-particle random phase approximation.

    Science.gov (United States)

    van Aggelen, Helen; Yang, Yang; Yang, Weitao

    2014-05-14

    Despite their unmatched success for many applications, commonly used local, semi-local, and hybrid density functionals still face challenges when it comes to describing long-range interactions, static correlation, and electron delocalization. Density functionals of both the occupied and virtual orbitals are able to address these problems. The particle-hole (ph-) Random Phase Approximation (RPA), a functional of occupied and virtual orbitals, has recently known a revival within the density functional theory community. Following up on an idea introduced in our recent communication [H. van Aggelen, Y. Yang, and W. Yang, Phys. Rev. A 88, 030501 (2013)], we formulate more general adiabatic connections for the correlation energy in terms of pairing matrix fluctuations described by the particle-particle (pp-) propagator. With numerical examples of the pp-RPA, the lowest-order approximation to the pp-propagator, we illustrate the potential of density functional approximations based on pairing matrix fluctuations. The pp-RPA is size-extensive, self-interaction free, fully anti-symmetric, describes the strong static correlation limit in H2, and eliminates delocalization errors in H2(+) and other single-bond systems. It gives surprisingly good non-bonded interaction energies--competitive with the ph-RPA--with the correct R(-6) asymptotic decay as a function of the separation R, which we argue is mainly attributable to its correct second-order energy term. While the pp-RPA tends to underestimate absolute correlation energies, it gives good relative energies: much better atomization energies than the ph-RPA, as it has no tendency to underbind, and reaction energies of similar quality. The adiabatic connection in terms of pairing matrix fluctuation paves the way for promising new density functional approximations.

  9. Exchange-correlation energy from pairing matrix fluctuation and the particle-particle random phase approximation

    International Nuclear Information System (INIS)

    Aggelen, Helen van; Yang, Yang; Yang, Weitao

    2014-01-01

    Despite their unmatched success for many applications, commonly used local, semi-local, and hybrid density functionals still face challenges when it comes to describing long-range interactions, static correlation, and electron delocalization. Density functionals of both the occupied and virtual orbitals are able to address these problems. The particle-hole (ph-) Random Phase Approximation (RPA), a functional of occupied and virtual orbitals, has recently known a revival within the density functional theory community. Following up on an idea introduced in our recent communication [H. van Aggelen, Y. Yang, and W. Yang, Phys. Rev. A 88, 030501 (2013)], we formulate more general adiabatic connections for the correlation energy in terms of pairing matrix fluctuations described by the particle-particle (pp-) propagator. With numerical examples of the pp-RPA, the lowest-order approximation to the pp-propagator, we illustrate the potential of density functional approximations based on pairing matrix fluctuations. The pp-RPA is size-extensive, self-interaction free, fully anti-symmetric, describes the strong static correlation limit in H 2 , and eliminates delocalization errors in H 2 + and other single-bond systems. It gives surprisingly good non-bonded interaction energies – competitive with the ph-RPA – with the correct R −6 asymptotic decay as a function of the separation R, which we argue is mainly attributable to its correct second-order energy term. While the pp-RPA tends to underestimate absolute correlation energies, it gives good relative energies: much better atomization energies than the ph-RPA, as it has no tendency to underbind, and reaction energies of similar quality. The adiabatic connection in terms of pairing matrix fluctuation paves the way for promising new density functional approximations

  10. Broken flavor symmetries in high energy particle phenomenology

    International Nuclear Information System (INIS)

    Antaramian, A.

    1995-01-01

    Over the past couple of decades, the Standard Model of high energy particle physics has clearly established itself as an invaluable tool in the analysis of high energy particle phenomenon. However, from a field theorists point of view, there are many dissatisfying aspects to the model. One of these, is the large number of free parameters in the theory arising from the Yukawa couplings of the Higgs doublet. In this thesis, we examine various issues relating to the Yukawa coupeng structure of high energy particle field theories. We begin by examining extensions to the Standard Model of particle physics which contain additional scalar fields. By appealing to the flavor structure observed in the fermion mass and Kobayashi-Maskawa matrices, we propose a reasonable phenomenological parameterization of the new Yukawa couplings based on the concept of approximate flavor symmetries. It is shown that such a parameterization eliminates the need for discrete symmetries which limit the allowed couplings of the new scalars. New scalar particles which can mediate exotic flavor changing reactions can have masses as low as the weak scale. Next, we turn to the issue of neutrino mass matrices, where we examine a particular texture which leads to matter independent neutrino oscillation results for solar neutrinos. We, then, examine the basis for extremely strict limits placed on flavor changing interactions which also break lepton- and/or baryon-number. These limits are derived from cosmological considerations. Finally, we embark on an extended analysis of proton decay in supersymmetric SO(10) grand unified theories. In such theories, the dominant decay diagrams involve the Yukawa couplings of a heavy triplet superfield. We argue that past calculations of proton decay which were based on the minimal supersymmetric SU(5) model require reexamination because the Yukawa couplings of that theory are known to be wrong

  11. A scintillation detector set measuring the charge particle energy

    International Nuclear Information System (INIS)

    Dore, Chantal.

    1979-01-01

    The S143 experiment, at CERN in 1976, needed both the measurement and the identification of light nuclei, and especially the separation between 3 H and 3 He, over a large energy range. In the chosen solution, in addition to semiconductor detectors, some scintillation counters are used. The non-linearity of light versus energy of charged particles was complicated by the fact there was two different linear laws according to the charge of particles. To obtain good analogic signals over a dynamic range nearly equal to 200, the signals from several dynodes were used simultaneously. In the experimental setting up, each scintillator was put directly in contact with the corresponding photocathode. In spite of a special shielding, some perturbations due to the magnet placed close by required to bring important corrections to linear laws. Thanks to complementary informations from semiconductor counters, a full separation between charge 1 and charge 2 particles was possible. A suitable identification as guaranted among charge 1 particles, but only kinematic constraints gave the possibility to extract 4 He corresponding to the elastic scattering [fr

  12. Emission of high-energy, light particles from intermediate-energy heavy-ion reactions

    International Nuclear Information System (INIS)

    Ball, J.B.; Auble, R.L.

    1982-01-01

    One of the early surprises in examining reaction products from heavy ion reactions at 10 MeV/nucleon and above was the large yield of light particles emitted and the high energies to which the spectra of these particles extended. The interpretation of the origin of the high energy light ions has evolved from a picture of projectile excitation and subsequent evaporation to one of pre-equilibrium (or nonequilibrium) emission. The time scale for particle emission has thus moved from one that occurs following the initial collision to one that occurs at the very early stages of the collision. Research at ORNL on this phenomenon is reviewed

  13. Variation of energy absorption buildup factors with incident photon energy and penetration depth for some commonly used solvents

    International Nuclear Information System (INIS)

    Singh, Parjit S.; Singh, Tejbir; Kaur, Paramjeet

    2008-01-01

    G.P. fitting method has been used to compute energy absorption buildup factor of some commonly used solvents such as acetonitrile (C 4 H 3 N), butanol (C 4 H 9 OH), chlorobenzene (C 6 H 5 Cl), diethyl ether (C 4 H 10 O), ethanol (C 2 H 5 OH), methanol (CH 3 OH), propanol (C 3 H 7 OH) and water (H 2 O) for the wide energy range (0.015-15.0 MeV) up to the penetration depth of 10 mean free path. The variation of energy absorption buildup factor with chemical composition as well as incident photon energy for the selected solvents has been studied. It has been observed that the maximum value of energy absorption buildup factors shifts to the slightly higher incident photon energy with the increase in equivalent atomic number of the solvent and the solvent with least equivalent atomic number possesses the maximum value of energy absorption buildup factor

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

    Science.gov (United States)

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

    1994-01-01

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

  15. Cryogenic Beam Screens for High-Energy Particle Accelerators

    CERN Document Server

    Baglin, V; Tavian, L; van Weelderen, R

    2013-01-01

    Applied superconductivity has become a key enabling technology for high-energy particle accelerators, thus making them large helium cryogenic systems operating at very low temperature. The circulation of high-intensity particle beams in these machines generates energy deposition in the first wall through different processes. For thermodynamic efficiency, it is advisable to intercept these beam-induced heat loads, which may be large in comparison with cryostat heat in-leaks, at higher temperature than that of the superconducting magnets of the accelerator, by means of beam screens located in the magnet apertures. Beam screens may also be used as part of the ultra-high vacuum system of the accelerator, by sheltering the gas molecules cryopumped on the beam pipe from impinging radiation and thus avoiding pressure runaway. Space being extremely tight in the magnet apertures, cooling of the long, slender beam screens also raises substantial problems in cryogenic heat transfer and fluid flow. We present sizing rule...

  16. The low-energy frontier of particle physics

    Energy Technology Data Exchange (ETDEWEB)

    Jaeckel, Joerg [Durham Univ. (United Kingdom). Inst. for Particle Physics Phenomenology; Ringwald, Andreas [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany)

    2010-02-15

    Most embeddings of the Standard Model into a more unified theory, in particular the ones based on supergravity or superstrings, predict the existence of a hidden sector of particles which have only very weak interactions with the visible sector Standard Model particles. Some of these exotic particle candidates (such as e.g. ''axions'', ''axion-like particles'' and ''hidden U(1) gauge bosons'') may be very light, with masses in the sub-eV range, and have very weak interactions with photons. Correspondingly, these very weakly interacting sub-eV particles (WISPs) may lead to observable effects in experiments (as well as in astrophysical and cosmological observations) searching for light shining through a wall, for changes in laser polarisation, for non-linear processes in large electromagnetic fields and for deviations from Coulomb's law. We present the physics case and a status report of this emerging low-energy frontier of fundamental physics. (orig.)

  17. Effect of free-particle collisions in high energy proton and pion-induced nuclear reactions

    International Nuclear Information System (INIS)

    Jacob, N.P. Jr.

    1975-07-01

    The effect of free-particle collisions in simple ''knockout'' reactions of the form (a,aN) and in more complex nuclear reactions of the form (a,X) was investigated by using protons and pions. Cross sections for the 48 Ti(p,2p) 47 Sc and the 74 Ge(p,2p) 73 Ga reactions were measured from 0.3 to 4.6 GeV incident energy. The results indicate a rise in (p,2p) cross section for each reaction of about (25 +- 3) percent between the energies 0.3 and 1.0 GeV, and are correlated to a large increase in the total free-particle pp scattering cross sections over the same energy region. Results are compared to previous (p,2p) excitation functions in the GeV energy region and to (p,2p) cross section calculations based on a Monte Carlo intranuclear cascade-evaporation model. Cross section measurements for (π/sup +-/, πN) and other more complex pion-induced spallation reactions were measured for the light target nuclei 14 N, 16 O, and 19 F from 45 to 550 MeV incident pion energy. These measurements indicate a broad peak in the excitation functions for both (π,πN) and (π,X) reactions near 180 MeV incident energy. This corresponds to the large resonances observed in the free-particle π + p and π - p cross sections at the same energy. Striking differences in (π,πN) cross section magnitudes are observed among the light nuclei targets. The experimental cross section ratio sigma(π - ,π - n)/sigma(π + ,πN) at 180 MeV is 1.7 +- 0.2 for all three targets. The experimental results are compared to previous pion and analogous proton-induced reactions, to Monte Carlo intranuclear cascade-evaporation calculations, and to a semi-classical nucleon charge exchange model. (108 references) (auth)

  18. Correlations between high momentum particles in proton-proton collisions at high energies

    International Nuclear Information System (INIS)

    Bobbink, G.J.

    1981-01-01

    This thesis describes an experiment performed at the CERN Intersecting Storage Rings. The experiment studies the reaction p+p→h 1 +h 2 +X at two centre-of-mass energies, √s=44.7 GeV and √s=62.3 GeV. Two of the outgoing particles (h 1 and h 2 ) are detected in opposite c.m.s. hemispheres at small polar angles with respect to the direction of two incident protons. The remaining particles produced (X) are not detected. The hadrons hsub(i) are identified mesons (π + , π - , K + , K - ) or baryons (p, Λ) with relatively large longitudinal psub(L) and small transverse momentum psub(T). The aim of the experiment is twofold. The first aim is to study whether the momentum distributions of the fast particles hsub(i) are correlated and thereby to constrain the possible interaction mechanisms responsible for the production of high psub(L), low psub(T) particles. The second aim is to establish to what extent the production of pions and kaons in inclusive proton-proton collisions (e.g. p+p→π+X, X=all other particles) resembles the production of pions and kaons in diffractive proton-proton collisions (e.g. p+p→p+π+X, in which the final-state proton has a momentum close to its maximum possible value). (Auth.)

  19. Survey of particle codes in the Magnetic Fusion Energy Program

    International Nuclear Information System (INIS)

    1977-12-01

    In the spring of 1976, the Fusion Plasma Theory Branch of the Division of Magnetic Fusion Energy conducted a survey of all the physics computer codes being supported at that time. The purpose of that survey was to allow DMFE to prepare a description of the codes for distribution to the plasma physics community. This document is the first of several planned and covers those types of codes which treat the plasma as a group of particles

  20. Intrinsic charm and charmed particle production at Serpukhov energies

    International Nuclear Information System (INIS)

    Zmushko, V.V.

    1995-01-01

    This paper presents a study of the charmed particle production by protons on nuclei in the framework of two-component model at the Serpukhov energies. This model combines the leading-twist QCD and intrinsic charm contributions. It is shown that both contributions are comparable at 70 GeV energy of a proton, which makes possible the testing of the intrinsic charm predictions: the asymmetry between the leading and non-leading charm production and the A dependence of charm production. The asymmetry for D-bar/D mesons and Λ c + /Λ c - baryons and the cross section ratios for different nuclei are estimated [ru

  1. Particle and astrophysics aspects of ultrahigh energy cosmic rays

    International Nuclear Information System (INIS)

    Sigl, G.

    2001-01-01

    The origin of cosmic rays is one of the major unresolved astrophysical questions. In particular, the highest energy cosmic rays observed possess macroscopic energies and their origin is likely to be associated with the most energetic processes in the Universe. Their existence triggered a flurry of theoretical explanations ranging from conventional shock acceleration to particle physics beyond the Standard Model and processes taking place at the earliest moments of our Universe. Furthermore, many new experimental activities promise a strong increase of statistics at the highest energies and a combination with γ-ray and neutrino astrophysics will put strong constraints on these theoretical models. Detailed Monte Carlo simulations indicate that charged ultra-high energy cosmic rays can also be used as probes of large scale magnetic fields whose origin may open another window into the very early Universe. We give an overview over this quickly evolving research field. (author)

  2. Particle and astrophysics aspects of ultrahigh energy cosmic rays

    Energy Technology Data Exchange (ETDEWEB)

    Sigl, G [Institut d' Astrophysique de Paris, Paris (France)

    2001-11-15

    The origin of cosmic rays is one of the major unresolved astrophysical questions. In particular, the highest energy cosmic rays observed possess macroscopic energies and their origin is likely to be associated with the most energetic processes in the Universe. Their existence triggered a flurry of theoretical explanations ranging from conventional shock acceleration to particle physics beyond the Standard Model and processes taking place at the earliest moments of our Universe. Furthermore, many new experimental activities promise a strong increase of statistics at the highest energies and a combination with {gamma}-ray and neutrino astrophysics will put strong constraints on these theoretical models. Detailed Monte Carlo simulations indicate that charged ultra-high energy cosmic rays can also be used as probes of large scale magnetic fields whose origin may open another window into the very early Universe. We give an overview over this quickly evolving research field. (author)

  3. Collisions of polyatomic ions with surfaces: incident energy partitioning and chemical reactions

    International Nuclear Information System (INIS)

    Zabka, J.; Roithova, J.; Dolejsek, Z.; Herman, Z.

    2002-01-01

    Collision of polyatomic ions with surfaces were investigated in ion-surface scattering experiments to obtain more information on energy partitioning in ion-surface collision and on chemical reactions at surfaces. Mass spectra, translation energy and angular distributions of product ions were measured in dependence on the incident energy and the incident angle of polyatomic projectiles. From these data distributions of energy fractions resulting in internal excitation of the projectile, translation energy of the product ions, and energy absorbed by the surface were determined. The surface investigated were a standard stainless steel surface, covered by hydrocarbons, carbon surfaces at room and elevated temperatures, and several surfaces covered by a self-assembled monolayers (C 12 -hydrocarbon SAM, C 11 -perfluorohydrocarbon SAM, and C 11 hydrocarbon with terminal -COOH group SAM). The main processes observed at collision energies of 10 - 50 eV were: neutralization of the ions at surfaces, inelastic scattering and dissociations of the projectile ions, quasi elastic scattering of the projectile ions, and chemical reactions with the surface material (usually hydrogen-atom transfer reactions). The ion survival factor was estimated to be a few percent for even-electron ions (like protonated ethanol ion, C 2 H 5 O + , CD 5 + ) and about 10 - 10 2 times lower for radical ions (like ethanol and benzene molecular ions, CD 4 + ). In the polyatomic ion -surface energy transfer experiments, the ethanol molecular ion was used as a well-characterized projectile ion. The results with most of the surfaces studied showed in the collision energy range of 13 - 32 eV that most collisions were strongly inelastic with about 6 - 8 % of the incident projectile energy transformed into internal excitation of the projectile (independent of the incident angle) and led partially to its further dissociation in a unimolecular way after the interaction with the surface. The incident energy

  4. Long-term exposure to ambient ultrafine particles and respiratory disease incidence in in Toronto, Canada: a cohort study.

    Science.gov (United States)

    Weichenthal, Scott; Bai, Li; Hatzopoulou, Marianne; Van Ryswyk, Keith; Kwong, Jeffrey C; Jerrett, Michael; van Donkelaar, Aaron; Martin, Randall V; Burnett, Richard T; Lu, Hong; Chen, Hong

    2017-06-19

    Little is known about the long-term health effects of ambient ultrafine particles (respiratory disease incidence. In this study, we examined the relationship between long-term exposure to ambient UFPs and the incidence of lung cancer, adult-onset asthma, and chronic obstructive pulmonary disease (COPD). Our study cohort included approximately 1.1 million adults who resided in Toronto, Canada and who were followed for disease incidence between 1996 and 2012. UFP exposures were assigned to residential locations using a land use regression model. Random-effect Cox proportional hazard models were used to estimate hazard ratios (HRs) describing the association between ambient UFPs and respiratory disease incidence adjusting for ambient fine particulate air pollution (PM 2.5 ), NO 2 , and other individual/neighbourhood-level covariates. In total, 74,543 incident cases of COPD, 87,141 cases of asthma, and 12,908 cases of lung cancer were observed during follow-up period. In single pollutant models, each interquartile increase in ambient UFPs was associated with incident COPD (HR = 1.06, 95% CI: 1.05, 1.09) but not asthma (HR = 1.00, 95% CI: 1.00, 1.01) or lung cancer (HR = 1.00, 95% CI: 0.97, 1.03). Additional adjustment for NO 2 attenuated the association between UFPs and COPD and the HR was no longer elevated (HR = 1.01, 95% CI: 0.98, 1.03). PM 2.5 and NO 2 were each associated with increased incidence of all three outcomes but risk estimates for lung cancer were sensitive to indirect adjustment for smoking and body mass index. In general, we did not observe clear evidence of positive associations between long-term exposure to ambient UFPs and respiratory disease incidence independent of other air pollutants. Further replication is required as few studies have evaluated these relationships.

  5. Prediction of sound transmission loss through multilayered panels by using Gaussian distribution of directional incident energy

    Science.gov (United States)

    Kang; Ih; Kim; Kim

    2000-03-01

    In this study, a new prediction method is suggested for sound transmission loss (STL) of multilayered panels of infinite extent. Conventional methods such as random or field incidence approach often given significant discrepancies in predicting STL of multilayered panels when compared with the experiments. In this paper, appropriate directional distributions of incident energy to predict the STL of multilayered panels are proposed. In order to find a weighting function to represent the directional distribution of incident energy on the wall in a reverberation chamber, numerical simulations by using a ray-tracing technique are carried out. Simulation results reveal that the directional distribution can be approximately expressed by the Gaussian distribution function in terms of the angle of incidence. The Gaussian function is applied to predict the STL of various multilayered panel configurations as well as single panels. The compared results between the measurement and the prediction show good agreements, which validate the proposed Gaussian function approach.

  6. Binding energy and single–particle Energies in the 16 0 region ...

    African Journals Online (AJOL)

    ... single-particle energies in the oxygen region by folding together a Hamiltonian in the rest-frame of the nucleus with two-body correlation functions based on the Njimegen potential. We have found that the binding energies are very sensitive to the core radius rc and that the effects of tensor correlations are non-negligible.

  7. Airborne Release of Particles in Overheating Incidents Involving Plutonium Metal and Compounds

    Energy Technology Data Exchange (ETDEWEB)

    Schwendiman, L. C.; Mishima, J.; Radasch, C. A. [Battelle Memorial Institute, Pacific Northwest Laboratory, Richland, WA (United States)

    1968-12-15

    Ever-increasing utilization of nuclear fuels will result in wide-scale plutonium recovery processing, reconstitution of fuels, transportation, and extensive handling of this material. A variety of circumstances resulting in overheating and fires involving plutonium may occur, releasing airborne particles. This work describes the observations from a study in which the airborne release of plutonium and its compounds was measured during an exposure of the material of interest containing plutonium to temperatures which may result from fires. Aerosol released from small cylinders of metallic plutonium ignited in air at temperatures from 410 to 650 Degree-Sign C ranged from 3 x 10{sup -6} to 5 x 10{sup -5} wt%. Particles smaller than 15{mu}m in diameter represented as much as 0.03% of the total released. Large plutonium pieces weighing from 456 to 1770 g were ignited and allowed to oxidize completely in air with a velocity of around 500 cm/sec. Release rates of from 0.0045 to 0.032 wt% per hour were found. The median mass diameter of airborne material was 4 {mu}m. Quenching the oxidation with magnesium oxide sand reduced the release to 2.9 X 10{sup -4} wt% per hour. Many experiments were carried out in which plutonium compounds as powders were heated at temperatures ranging from 700 to 1000 Degree-Sign C with several air flows. Release rates ranged from 5 x 10{sup -8} to 0.9 wt% per hour, depending upon the compound and the conditions imposed. The airborne release from boiling solutions of plutonium nitrate were roughly related to energy of boiling, and ranged from 4 x 10{sup -4} to 2 x 10{sup -1} % for the evaporation of 90% of the solution. The fraction airborne when combustibles contaminated with plutonium are burned is under study. The data reported can be used in assessing the consequences of off-standard situations involving plutonium and its compounds in fires. (author)

  8. Evaluate an impact of incident alpha particle and gamma ray on human blood components: A comparison study

    Energy Technology Data Exchange (ETDEWEB)

    Ismail, Asaad H.; Yaba, Sardar P.; Ismail, Haider J. [Medical Physics Research Group, Physics Department, Education College, Salahaddin University-Erbil, Iraqi Kurdistan (Iraq)

    2015-07-01

    An impact of alpha and gamma irradiation on human blood components have been evaluated and compared for healthy blood samples (male and females). Irradiation dose and time of irradiation calibrated and considered as a main comparison factors. Density of blood components measured for each in vitro irradiation before and after irradiation for males and females. Survey radiation dosimeter (Inspector Exp) and nuclear track detectors type CR-39 used to evaluate exposure dose rate and incident density of alpha particles, respectively. Experiment results verified that the irradiation of blood makes ionizing of blood components, either alpha or gamma irradiation dose, and the impacts of ionizing radiation were relativity for WBC, RBC, and PLT. Limited irradiation doses of 1-5 μSv/hr considered as a low radiation dose of alpha and gamma radiation sources ({sup 226}Ra, and {sup 137}Cs). Density of alpha particles accumulated on the blood surface was 34 (alpha particle/cm{sup 2}) for selected dose of incident alpha particle. Optimum value of irradiation dose and time of irradiation were 5 μSv/hr and 4 second for males and females. On the other hands, the values of irradiation dose and time of irradiation were 2.1 μSv/hr and 2 second for males and females for gamma irradiation. Thus, present results demonstrated that densities of RBC and WBC cells are capable of inducing reproduction in vitro for both type of irradiation. (authors)

  9. Evaluate an impact of incident alpha particle and gamma ray on human blood components: A comparison study

    International Nuclear Information System (INIS)

    Ismail, Asaad H.; Yaba, Sardar P.; Ismail, Haider J.

    2015-01-01

    An impact of alpha and gamma irradiation on human blood components have been evaluated and compared for healthy blood samples (male and females). Irradiation dose and time of irradiation calibrated and considered as a main comparison factors. Density of blood components measured for each in vitro irradiation before and after irradiation for males and females. Survey radiation dosimeter (Inspector Exp) and nuclear track detectors type CR-39 used to evaluate exposure dose rate and incident density of alpha particles, respectively. Experiment results verified that the irradiation of blood makes ionizing of blood components, either alpha or gamma irradiation dose, and the impacts of ionizing radiation were relativity for WBC, RBC, and PLT. Limited irradiation doses of 1-5 μSv/hr considered as a low radiation dose of alpha and gamma radiation sources ( 226 Ra, and 137 Cs). Density of alpha particles accumulated on the blood surface was 34 (alpha particle/cm 2 ) for selected dose of incident alpha particle. Optimum value of irradiation dose and time of irradiation were 5 μSv/hr and 4 second for males and females. On the other hands, the values of irradiation dose and time of irradiation were 2.1 μSv/hr and 2 second for males and females for gamma irradiation. Thus, present results demonstrated that densities of RBC and WBC cells are capable of inducing reproduction in vitro for both type of irradiation. (authors)

  10. High energy particle transport code NMTC/JAM

    International Nuclear Information System (INIS)

    Niita, Koji; Meigo, Shin-ichiro; Takada, Hiroshi; Ikeda, Yujiro

    2001-03-01

    We have developed a high energy particle transport code NMTC/JAM, which is an upgraded version of NMTC/JAERI97. The applicable energy range of NMTC/JAM is extended in principle up to 200 GeV for nucleons and mesons by introducing the high energy nuclear reaction code JAM for the intra-nuclear cascade part. For the evaporation and fission process, we have also implemented a new model, GEM, by which the light nucleus production from the excited residual nucleus can be described. According to the extension of the applicable energy, we have upgraded the nucleon-nucleus non-elastic, elastic and differential elastic cross section data by employing new systematics. In addition, the particle transport in a magnetic field has been implemented for the beam transport calculations. In this upgrade, some new tally functions are added and the format of input of data has been improved very much in a user friendly manner. Due to the implementation of these new calculation functions and utilities, consequently, NMTC/JAM enables us to carry out reliable neutronics study of a large scale target system with complex geometry more accurately and easily than before. This report serves as a user manual of the code. (author)

  11. IceCube: Particle Astrophysics with High Energy Neutrinos

    CERN Multimedia

    Université de Genève

    2012-01-01

    GENEVA UNIVERSITY École de physique Département de physique nucléaire et corspusculaire 24, quai Ernest-Ansermet 1211 Genève 4 Tél.: (022) 379 62 73 Fax: (022) 379 69 92 Monday 7 May 2012 17h. - Ecole de Physique, Auditoire Stueckelberg IceCube: Particle Astrophysics with High Energy Neutrinos Prof. Francis Halzen / University of Wisconsin, Madison Construction and commissioning of the cubic-kilometer IceCube neutrino detector and its low energy extension DeepCore have been completed. The instrument detects neutrinos over a wide energy range: from 10 GeV atmospheric neutrinos to 1010 GeV cosmogenic neutrinos. We will discuss initial results based on a subsample of the ~100,000 neutrino events recorded during construction. We will emphasize the first measurement of the high-energy atmospheric neutrino spectrum, the search for the still enigmatic sources of the Galactic and extragalactic cosmic rays and for the particle nature of dark matter. Une ve...

  12. Relativistic effects in the energy loss of a fast charged particle moving parallel to a two-dimensional electron gas

    Science.gov (United States)

    Mišković, Zoran L.; Akbari, Kamran; Segui, Silvina; Gervasoni, Juana L.; Arista, Néstor R.

    2018-05-01

    We present a fully relativistic formulation for the energy loss rate of a charged particle moving parallel to a sheet containing two-dimensional electron gas, allowing that its in-plane polarization may be described by different longitudinal and transverse conductivities. We apply our formulation to the case of a doped graphene layer in the terahertz range of frequencies, where excitation of the Dirac plasmon polariton (DPP) in graphene plays a major role. By using the Drude model with zero damping we evaluate the energy loss rate due to excitation of the DPP, and show that the retardation effects are important when the incident particle speed and its distance from graphene both increase. Interestingly, the retarded energy loss rate obtained in this manner may be both larger and smaller than its non-retarded counterpart for different combinations of the particle speed and distance.

  13. Cost-effectiveness and incidence of renewable energy promotion in Germany

    OpenAIRE

    Böhringer, Christoph; Landis, Florian; Tovar Reaños, Miguel Angel

    2017-01-01

    Over the last decade Germany has boosted renewable energy in power production by means of massive subsidies. The flip side are very high electricity prices which raises concerns that the transition cost towards a renewable energy system will be mainly borne by poor households. In this paper, we combine computable general equilibrium and microsimulation analysis to investigate the cost-effectiveness and incidence of Germany's renewable energy promotion. We find that the regressive effects of r...

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

    Science.gov (United States)

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

    1994-01-01

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

  15. New challenges in high-energy particle radiobiology

    Science.gov (United States)

    2014-01-01

    Densely ionizing radiation has always been a main topic in radiobiology. In fact, α-particles and neutrons are sources of radiation exposure for the general population and workers in nuclear power plants. More recently, high-energy protons and heavy ions attracted a large interest for two applications: hadrontherapy in oncology and space radiation protection in manned space missions. For many years, studies concentrated on measurements of the relative biological effectiveness (RBE) of the energetic particles for different end points, especially cell killing (for radiotherapy) and carcinogenesis (for late effects). Although more recently, it has been shown that densely ionizing radiation elicits signalling pathways quite distinct from those involved in the cell and tissue response to photons. The response of the microenvironment to charged particles is therefore under scrutiny, and both the damage in the target and non-target tissues are relevant. The role of individual susceptibility in therapy and risk is obviously a major topic in radiation research in general, and for ion radiobiology as well. Particle radiobiology is therefore now entering into a new phase, where beyond RBE, the tissue response is considered. These results may open new applications for both cancer therapy and protection in deep space. PMID:24198199

  16. Theories of Variable Mass Particles and Low Energy Nuclear Phenomena

    Science.gov (United States)

    Davidson, Mark

    2014-02-01

    Variable particle masses have sometimes been invoked to explain observed anomalies in low energy nuclear reactions (LENR). Such behavior has never been observed directly, and is not considered possible in theoretical nuclear physics. Nevertheless, there are covariant off-mass-shell theories of relativistic particle dynamics, based on works by Fock, Stueckelberg, Feynman, Greenberger, Horwitz, and others. We review some of these and we also consider virtual particles that arise in conventional Feynman diagrams in relativistic field theories. Effective Lagrangian models incorporating variable mass particle theories might be useful in describing anomalous nuclear reactions by combining mass shifts together with resonant tunneling and other effects. A detailed model for resonant fusion in a deuterium molecule with off-shell deuterons and electrons is presented as an example. Experimental means of observing such off-shell behavior directly, if it exists, is proposed and described. Brief explanations for elemental transmutation and formation of micro-craters are also given, and an alternative mechanism for the mass shift in the Widom-Larsen theory is presented. If variable mass theories were to find experimental support from LENR, then they would undoubtedly have important implications for the foundations of quantum mechanics, and practical applications may arise.

  17. Neutral strange particle production in neutrino interactions at Tevatron energies

    International Nuclear Information System (INIS)

    De, K.

    1988-05-01

    This thesis reports on a study of neutral strange particle production by high energy muon-neutrinos. The neutrinos were obtained from a 800 GeV proton beam-dump at Fermilab. Neutrino events were observed using a hybrid bubble chamber detector system. The data contained deep inelastic neutrino-nucleon interactions with an average momentum transfer 2 > = 23 (GeV/c) 2 . Rates for K 0 and Λ production in neutrino and anti-neutrino charged current events are presented. The distributions of these particles in Feynman x and rapidity are also studied. Significant differences were observed in the production mechanism for the K 0 meson and the Λ baryon. The production rates of K 0 's were observed to increase with energy, whereas the rates for Λ production remained essentially constant. In Feynman x, the K 0 's were produced in the central region and the Λ's were produced backwards. The data are compared with the LUND monte carlo for string fragmentation. In the monte carlo, K 0 's are mostly produced from s/bar s/ pair production during fragmentation. The Λ's are generally produced through recombination with the diquark from the target nucleon. The data agree with this model for strange particle production. 39 refs., 24 figs., 10 tabs

  18. Charged Particle, Photon Multiplicity, and Transverse Energy Production in High-Energy Heavy-Ion Collisions

    Directory of Open Access Journals (Sweden)

    Raghunath Sahoo

    2015-01-01

    Full Text Available We review the charged particle and photon multiplicities and transverse energy production in heavy-ion collisions starting from few GeV to TeV energies. The experimental results of pseudorapidity distribution of charged particles and photons at different collision energies and centralities are discussed. We also discuss the hypothesis of limiting fragmentation and expansion dynamics using the Landau hydrodynamics and the underlying physics. Meanwhile, we present the estimation of initial energy density multiplied with formation time as a function of different collision energies and centralities. In the end, the transverse energy per charged particle in connection with the chemical freeze-out criteria is discussed. We invoke various models and phenomenological arguments to interpret and characterize the fireball created in heavy-ion collisions. This review overall provides a scope to understand the heavy-ion collision data and a possible formation of a deconfined phase of partons via the global observables like charged particles, photons, and the transverse energy measurement.

  19. High energy particle transport code NMTC/JAM

    International Nuclear Information System (INIS)

    Niita, K.; Takada, H.; Meigo, S.; Ikeda, Y.

    2001-01-01

    We have developed a high energy particle transport code NMTC/JAM, which is an upgrade version of NMTC/JAERI97. The available energy range of NMTC/JAM is, in principle, extended to 200 GeV for nucleons and mesons including the high energy nuclear reaction code JAM for the intra-nuclear cascade part. We compare the calculations by NMTC/JAM code with the experimental data of thin and thick targets for proton induced reactions up to several 10 GeV. The results of NMTC/JAM code show excellent agreement with the experimental data. From these code validation, it is concluded that NMTC/JAM is reliable in neutronics optimization study of the high intense spallation neutron utilization facility. (author)

  20. High energy behaviour of particles and unified statistics

    International Nuclear Information System (INIS)

    Chang, Y.

    1984-01-01

    Theories and experiments suggest that particles at high energy appear to possess a new statistics unifying Bose-Einstein and Fermi-Dirac statistics via the GAMMA distribution. This hypothesis can be obtained from many models, and agrees quantitatively with scaling, the multiplicty, large transverse momentum, the mass spectrum, and other data. It may be applied to scatterings at high energy, and agrees with experiments and known QED's results. The Veneziano model and other theories have implied new statistics, such as, the B distribution and the Polya distribution. They revert to the GAMMA distribution at high energy. The possible inapplicability of Pauli's exclusion principle within the unified statistics is considered and associated to the quark constituents

  1. Numerical analysis of energy density and particle density in high energy heavy-ion collisions

    International Nuclear Information System (INIS)

    Fu Yuanyong; Lu Zhongdao

    2004-01-01

    Energy density and particle density in high energy heavy-ion collisions are calculated with infinite series expansion method and Gauss-Laguerre formulas in numerical integration separately, and the results of these two methods are compared, the higher terms and linear terms in series expansion are also compared. The results show that Gauss-Laguerre formulas is a good method in calculations of high energy heavy-ion collisions. (author)

  2. Variation in emission and energy recovery concerning incident angle in a scheme recovering high energy ions by secondary electrons

    International Nuclear Information System (INIS)

    Wada, Takayuki; Konno, Shota; Nakamoto, Satoshi; Takeno, Hiromasa; Furuyama, Yuichi; Taniike, Akira

    2016-01-01

    As an energy recovery device for fast protons produced in D- 3 He nuclear fusion, secondary electron (SE) direct energy converter (SEDEC) was proposed in addition to traveling wave direct energy converter (TWDEC). Some protons passing through a TWDEC come into an SEDEC, where protons penetrate to a number of foil electrodes and emitted SEs are recovered. Following to a development of SE orbit control by magnetic field, dependence on incident angle of protons was examined to optimize structure of SEDEC. Based on a theoretical expectation, experiments were performed by changing incident angle of protons and variation in emission and energy recovery were measured. Both emission and energy recovery increased as the angle increased, and differences with theoretical expectation are discussed. (author)

  3. Cost-effectiveness and incidence of renewable energy promotion in Germany

    Energy Technology Data Exchange (ETDEWEB)

    Boehringer, Christoph [Oldenburg Univ. (Germany). Dept. of Economics; Landis, Florian [Eidgenoessische Technische Hochschule, Zurich (Switzerland); Tovar Reanos, Miguel Angel [Zentrum fuer Europaeische Wirtschaftsforschung GmbH (ZEW), Mannheim (Germany)

    2017-08-01

    Over the last decade Germany has boosted renewable energy in power production by means of massive subsidies. The flip side are very high electricity prices which raises concerns that the transition cost towards a renewable energy system will be mainly borne by poor households. In this paper, we combine computable general equilibrium and microsimulation analysis to investigate the cost-effectiveness and incidence of Germany's renewable energy promotion. We find that the regressive effects of renewable energy promotion could be ameliorated by alternative subsidy financing mechanisms which achieve the same level of electricity generation from renewable energy sources.

  4. Graphical User Interface for High Energy Multi-Particle Transport, Phase II

    Data.gov (United States)

    National Aeronautics and Space Administration — Computer codes such as MCNPX now have the capability to transport most high energy particle types (34 particle types now supported in MCNPX) with energies extending...

  5. Graphical User Interface for High Energy Multi-Particle Transport, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — Computer codes such as MCNPX now have the capability to transport most high energy particle types (34 particle types now supported in MCNPX) with energies extending...

  6. Electronic Instrumentations for High Energy Particle Physics and Neutrino Physics

    CERN Document Server

    AUTHOR|(INSPIRE)INSPIRE-00452332

    The present dissertation describes design, qualification and operation of several electronic instrumentations for High Energy Particle Physics experiments (LHCb) and Neutrino Physics experiments (CUORE and CUPID). Starting from 2019, the LHCb experiment at the LHC accelerator will be upgraded to operate at higher luminosity and several of its detectors will be redesigned. The RICH detector will require a completely new optoelectronic readout system. The development of such system has already reached an advanced phase, and several tests at particle beam facilities allowed to qualify the performance of the entire system. In order to achieve a higher stability and a better power supply regulation for the front-end chip, a rad-hard low dropout linear regulator, named ALDO, has been developed. Design strategies, performance tests and results from the irradiation campaign are presented. In the Neutrino Physics field, large-scale bolometric detectors, like those adopted by CUORE and its future upgrade CUPID, offer u...

  7. Collective and single-particle states at high excitation energy

    International Nuclear Information System (INIS)

    Van den Berg, A.M.; Van der Molen, H.K.T.; Harakeh, M.N.; Akimune, H.; Daito, I.; Fujimura, H.; Fujiwara, M.; Ihara, F.; Inomata, T.

    2000-01-01

    Complete text of publication follows. Damping of high-lying single-particle states was investigated by the study of proton decay from high-lying states in 91 Nb, populated by the 90 Zr(α,t) reaction with E α = 180 MeV. In addition to decay to the ground state of 90 Zr, semi-direct decay was observed to the low-lying (2 + and 3 - ) phonon states, confirming the conclusion from other experiments that these phonon states play an important role in the damping process of the single-particle states. Furthermore, the population and decay of Isobaric Analogue States of 91 Zr, which are located at an excitation energy of about 10 - 12 MeV in 91 Nb, has been studied in the same reaction. (author)

  8. Control of particle precipitation by energy transfer from solar wind

    Science.gov (United States)

    Bremer, J.; Gernandt, H.

    1985-12-01

    The energy transfer function (epsilon), introduced by Perreault and Akasofu (1978), appears to be well suited for the description of the long-term control of the particle precipitation by interplanetary parameters. An investigation was conducted with the objective to test this control in more detail. This investigation included the calculation of hourly epsilon values on the basis of satellite-measured solar wind and IMF (interplanetary magnetic field) data. The results were compared with corresponding geomagnetic and ionospheric data. The ionospheric data had been obtained by three GDR (German Democratic Republic) teams during the 21st, 22nd, and 23rd Soviet Antarctic Expeditions in the time period from 1976 to 1979. It was found that, in high latitudes, the properties of the solar wind exercise a pronounced degree of control on the precipitation of energetic particles into the atmosphere, taking into account a time delay of about one hour due to the occurrence of magnetospheric storage processes.

  9. Energy straggling determination for charged particles in thick targets

    International Nuclear Information System (INIS)

    Lopez M, J.

    1980-01-01

    Energy straggling is reported for deuterons in carbon and protons in silicon, and the data obtained is compared with predictions of Bohr and Bethe. The experimental method used is based on a reaction resonance widening, observed at backward angles in the thick targets. The incident energy determines the depth at which the resonant scattering occurs and the energy straggling can be measured from the backscattering spectra. The data obtained for the energy straggling of deuterons are approximately two times bigger than those predicted by Bohr's theory; nevertheless, the values found for the energy straggling of protons in silicon are in agreement with the values predicted by the aforesaid theory. This disagreement was explained by the fact that carbon targets used were amorphous and porous, in contrast with those of cristal silicon, (it is an experimental fact that porous materials are expected to give higher stragglings than non-porous ones). Thus, the method reviewed in this work is valid, but the porosity effects should be taken into account in comparing results among materials with different densities. (author)

  10. Binding energy and single-particle energies in the 16O Region

    International Nuclear Information System (INIS)

    Fiase, J.O.; Sharma, L.K.

    2004-01-01

    In this paper we present the binding energy of 16 O together with single-particle energies in the oxygen region by folding together a Hamiltonian in the rest-frame of the nucleus with two-body correlation functions based on the Nijmegen potential. We have found that the binding energies are very sensitive to the core radius rc and that the effects of tensor correlations are non-negligible.Our calculated binding energy, E B = - 127.8 MeV with r c = 0.241 fm compares well with the experimental binding energy, E B = - 127.6 MeV

  11. Exactly energy conserving semi-implicit particle in cell formulation

    International Nuclear Information System (INIS)

    Lapenta, Giovanni

    2017-01-01

    We report a new particle in cell (PIC) method based on the semi-implicit approach. The novelty of the new method is that unlike any of its semi-implicit predecessors at the same time it retains the explicit computational cycle and conserves energy exactly. Recent research has presented fully implicit methods where energy conservation is obtained as part of a non-linear iteration procedure. The new method (referred to as Energy Conserving Semi-Implicit Method, ECSIM), instead, does not require any non-linear iteration and its computational cycle is similar to that of explicit PIC. The properties of the new method are: i) it conserves energy exactly to round-off for any time step or grid spacing; ii) it is unconditionally stable in time, freeing the user from the need to resolve the electron plasma frequency and allowing the user to select any desired time step; iii) it eliminates the constraint of the finite grid instability, allowing the user to select any desired resolution without being forced to resolve the Debye length; iv) the particle mover has a computational complexity identical to that of the explicit PIC, only the field solver has an increased computational cost. The new ECSIM is tested in a number of benchmarks where accuracy and computational performance are tested. - Highlights: • We present a new fully energy conserving semi-implicit particle in cell (PIC) method based on the implicit moment method (IMM). The new method is called Energy Conserving Implicit Moment Method (ECIMM). • The novelty of the new method is that unlike any of its predecessors at the same time it retains the explicit computational cycle and conserves energy exactly. • The new method is unconditionally stable in time, freeing the user from the need to resolve the electron plasma frequency. • The new method eliminates the constraint of the finite grid instability, allowing the user to select any desired resolution without being forced to resolve the Debye length. • These

  12. Exactly energy conserving semi-implicit particle in cell formulation

    Energy Technology Data Exchange (ETDEWEB)

    Lapenta, Giovanni, E-mail: giovanni.lapenta@kuleuven.be

    2017-04-01

    We report a new particle in cell (PIC) method based on the semi-implicit approach. The novelty of the new method is that unlike any of its semi-implicit predecessors at the same time it retains the explicit computational cycle and conserves energy exactly. Recent research has presented fully implicit methods where energy conservation is obtained as part of a non-linear iteration procedure. The new method (referred to as Energy Conserving Semi-Implicit Method, ECSIM), instead, does not require any non-linear iteration and its computational cycle is similar to that of explicit PIC. The properties of the new method are: i) it conserves energy exactly to round-off for any time step or grid spacing; ii) it is unconditionally stable in time, freeing the user from the need to resolve the electron plasma frequency and allowing the user to select any desired time step; iii) it eliminates the constraint of the finite grid instability, allowing the user to select any desired resolution without being forced to resolve the Debye length; iv) the particle mover has a computational complexity identical to that of the explicit PIC, only the field solver has an increased computational cost. The new ECSIM is tested in a number of benchmarks where accuracy and computational performance are tested. - Highlights: • We present a new fully energy conserving semi-implicit particle in cell (PIC) method based on the implicit moment method (IMM). The new method is called Energy Conserving Implicit Moment Method (ECIMM). • The novelty of the new method is that unlike any of its predecessors at the same time it retains the explicit computational cycle and conserves energy exactly. • The new method is unconditionally stable in time, freeing the user from the need to resolve the electron plasma frequency. • The new method eliminates the constraint of the finite grid instability, allowing the user to select any desired resolution without being forced to resolve the Debye length. • These

  13. The energy deposition of slowing down particles in heterogeneous media

    International Nuclear Information System (INIS)

    Prinja, A.K.; Williams, M.M.R.

    1980-01-01

    Energy deposition by atomic particles in adjacent semi-infinite, amorphous media is described using the forward form of the Boltzmann transport equation. A transport approximation to the scattering kernel, developed elsewhere, incorporating realistic energy transfer is employed to assess the validity of the commonly used isotropic-scattering and straight-ahead approximations. Results are presented for integral energy deposition rates due to a plane, isotropic and monoenergetic source in one half-space for a range of mass ratios between 0.1 and 5.0. Integral profiles for infinite and semi-infinite media are considered and the influence of reflection for different mass ratios is evaluated. The dissimilar scattering properties of the two media induce a discontinuity at the interface in the energy deposition rate the magnitude of which is sensitive to the source position relative to the interface. A comprehensive evaluation of the total energy deposited in the source free medium is presented for a range of mass ratios and source positions. An interesting minimum occurs for off-interface source locations as a function of the source-medium mass ratio, the position of which varies with the source position but is insensitive to the other mass ratio. As a special case, energy reflection and escape coefficients for semi-infinite media are obtained which demonstrates that the effect of a vacuum interface is insignificant for deep source locations except for large mass ratios when reflection becomes dominant. (author)

  14. Limiting technologies for particle beams and high energy physics

    International Nuclear Information System (INIS)

    Panofsky, W.K.H.

    1985-07-01

    Since 1930 the energy of accelerators had grown by an order of magnitude roughly every 7 years. Like all exponential growths, be they human population, the size of computers, or anything else, this eventually will have to come to an end. When will this happen to the growth of the energy of particle accelerators and colliders. Fortunately, as the energy of accelerators has grown the cost per unit energy has decreased almost as fast as has the increase in energy. The result is that while the energy has increased so dramatically the cost per new installation has increased only by roughly an order of magnitude since the 1930's (corrected for inflation), while the number of accelerators operating at the frontier of the field has shrunk. As is shown in the by now familiar Livingston chart this dramatic decrease in cost has been achieved largely by a succession of new technologies, in addition to the more moderate gains in efficiency due to improved design, economies of scale, etc. We are therefore facing two questions: (1) Is there good reason scientifically to maintain the exponential growth, and (2) Are there new technologies in sight which promise continued decreases in unit costs. The answer to the first question is definitely yes; the answer to the second question is maybe

  15. Load management strategy for Particle-In-Cell simulations in high energy particle acceleration

    Energy Technology Data Exchange (ETDEWEB)

    Beck, A., E-mail: beck@llr.in2p3.fr [Laboratoire Leprince-Ringuet, École polytechnique, CNRS-IN2P3, Palaiseau 91128 (France); Frederiksen, J.T. [Niels Bohr Institute, University of Copenhagen, Blegdamsvej 17, 2100 København Ø (Denmark); Dérouillat, J. [CEA, Maison de La Simulation, 91400 Saclay (France)

    2016-09-01

    In the wake of the intense effort made for the experimental CILEX project, numerical simulation campaigns have been carried out in order to finalize the design of the facility and to identify optimal laser and plasma parameters. These simulations bring, of course, important insight into the fundamental physics at play. As a by-product, they also characterize the quality of our theoretical and numerical models. In this paper, we compare the results given by different codes and point out algorithmic limitations both in terms of physical accuracy and computational performances. These limitations are illustrated in the context of electron laser wakefield acceleration (LWFA). The main limitation we identify in state-of-the-art Particle-In-Cell (PIC) codes is computational load imbalance. We propose an innovative algorithm to deal with this specific issue as well as milestones towards a modern, accurate high-performance PIC code for high energy particle acceleration.

  16. Energy group structure determination using particle swarm optimization

    International Nuclear Information System (INIS)

    Yi, Ce; Sjoden, Glenn

    2013-01-01

    Highlights: ► Particle swarm optimization is applied to determine broad group structure. ► A graph representation of the broad group structure problem is introduced. ► The approach is tested on a fuel-pin model. - Abstract: Multi-group theory is widely applied for the energy domain discretization when solving the Linear Boltzmann Equation. To reduce the computational cost, fine group cross libraries are often down-sampled into broad group cross section libraries. Cross section data collapsing generally involves two steps: Firstly, the broad group structure has to be determined; secondly, a weighting scheme is used to evaluate the broad cross section library based on the fine group cross section data and the broad group structure. A common scheme is to average the fine group cross section weighted by the fine group flux. Cross section collapsing techniques have been intensively researched. However, most studies use a pre-determined group structure, open based on experience, to divide the neutron energy spectrum into thermal, epi-thermal, fast, etc. energy range. In this paper, a swarm intelligence algorithm, particle swarm optimization (PSO), is applied to optimize the broad group structure. A graph representation of the broad group structure determination problem is introduced. And the swarm intelligence algorithm is used to solve the graph model. The effectiveness of the approach is demonstrated using a fuel-pin model

  17. Single particle tracking and single molecule energy transfer

    CERN Document Server

    Bräuchle, Christoph; Michaelis, Jens

    2009-01-01

    Closing a gap in the literature, this handbook gathers all the information on single particle tracking and single molecule energy transfer. It covers all aspects of this hot and modern topic, from detecting virus entry to membrane diffusion, and from protein folding using spFRET to coupled dye systems, as well recent achievements in the field. Throughout, the first-class editors and top international authors present content of the highest quality, making this a must-have for physical chemists, spectroscopists, molecular physicists and biochemists.

  18. Transport and containment of plasma, particles and energy within flares

    Science.gov (United States)

    Acton, L. W.; Brown, W. A.; Bruner, M. E. C.; Haisch, B. M.; Strong, K. T.

    1983-01-01

    Results from the analysis of flares observed by the Solar Maximum Mission (SMM) and a recent rocket experiment are discussed. Evidence for primary energy release in the corona through the interaction of magnetic structures, particle and plasma transport into more than a single magnetic structure at the time of a flare and a complex and changing magnetic topology during the course of a flare is found. The rocket data are examined for constraints on flare cooling, within the context of simple loop models. These results form a basis for comments on the limitations of simple loop models for flares.

  19. Elementary particles and high energy phenomena: Progress report

    International Nuclear Information System (INIS)

    Cumalat, J.P.

    1988-01-01

    This paper reviews the research being done at the University of Colorado in High Energy Physics. Topics discussed in this paper are: Charmed Photoproduction; Hadronic Production of Charm Particles; Photoproduction of States Containing Heavy Quarks; Electron-Positron Physics with the MAC Detector at PEP; Electron-Positron Physics with the Upgraded Mark II Detector at SLC; The SLD Detector at SLC; Nonperturbative Studies of QCD; Hadron Phenomenology - Application to Experiment; Perturbative QCD and Weak Matrix Elements; Quarkonium Physics; Supersymmetry, Supergravity, and Superstrings; and Experimental Gravity. 50 refs., 13 figs

  20. Accurate Quasiparticle Spectra from the T-Matrix Self-Energy and the Particle-Particle Random Phase Approximation.

    Science.gov (United States)

    Zhang, Du; Su, Neil Qiang; Yang, Weitao

    2017-07-20

    The GW self-energy, especially G 0 W 0 based on the particle-hole random phase approximation (phRPA), is widely used to study quasiparticle (QP) energies. Motivated by the desirable features of the particle-particle (pp) RPA compared to the conventional phRPA, we explore the pp counterpart of GW, that is, the T-matrix self-energy, formulated with the eigenvectors and eigenvalues of the ppRPA matrix. We demonstrate the accuracy of the T-matrix method for molecular QP energies, highlighting the importance of the pp channel for calculating QP spectra.

  1. Phenomenological model for particle production from the collisions of nucleons and pions with fissile elements at medium energies

    International Nuclear Information System (INIS)

    Alsmiller, F.S.; Alsmiller, R.G. Jr.; Gabriel, T.A.; Lillie, R.A.; Barish, J.

    1981-03-01

    A fission channel has been added to the intranuclear-cascade-evaporation model of nuclear reactions so that this model may be used to obtain the differential particle production data that are needed to study the transport of medium-energy nucleons and pions through fissionable material. The earlier work of Hahn and Bertini on the incorporation of fission-evaporation competition into the intranuclear-cascade-evaporation model has been retained, and the statistical model of fission has been utilized to predict particle production from the fission process. Approximate empirically derived kinetic energies and deformation energies are used in the statistical model. The calculated number of emitted neutrons and residual nuclei distributions are in reasonable agreement with experimental data, but the number of emitted neutrons at the higher incident nucleon energies (approx. > 500 MeV) are sensitive to the level density parameter used. 9 figures, 2 tables

  2. Recipients of 2013 EPS High Energy & Particle Physics Prize

    CERN Multimedia

    ATLAS, Experiment

    2014-01-01

    (From left) Joe Incandela, Peter Higgs, Francois Englert, Tejinder Virdee, Dave Charlton, and Peter Jenni. Higgs and Englert gave the prizes to the recipients of the 2013 European Physical Society's High Energy and Particle Physics Prize, for an outstanding contribution to high energy physics. "For the discovery of a Higgs boson, as predicted by the Brout-Englert-Higgs mechanism," the prize was awarded to the ATLAS and CMS collaborations. Spokesperson for CMS, Incandela, and Spokesperson for ATLAS, Charlton, accepted the awards on their collaborations' behalf. "For their pioneering and outstanding leadership roles in the making of the ATLAS and CMS experiments," the prize was awarded to Jenni, Virdee, and Michel Della Negra (not present). Image: ATLAS

  3. High-energy tail distributions and resonant wave particle interaction

    Science.gov (United States)

    Leubner, M. P.

    1983-01-01

    High-energy tail distributions (k distributions) are used as an alternative to a bi-Lorentzian distribution to study the influence of energetic protons on the right- and left-hand cyclotron modes in a hot two-temperature plasma. Although the parameters are chosen to be in a range appropriate to solar wind or magnetospheric configurations, the results apply not only to specific space plasmas. The presence of energetic particles significantly alters the behavior of the electromagnetic ion cyclotron modes, leading to a wide range of unstable frequencies and increased growth rates. From the strongly enhanced growth rates it can be concluded that high-energy tail distributions should not show major temperature anisotropies, which is consistent with observations.

  4. Investigation of Rare Particle Production in High Energy Nuclear Collisions

    International Nuclear Information System (INIS)

    Crawford, Henry J.; Engelage, Jon M.

    1999-01-01

    Our program is an investigation of the hadronization process through measurement of rare particle production in high energy nuclear interactions. Such collisions of heavy nuclei provide an environment similar in energy density to the conditions in the Big Bang. We are currently involved in two major experiments to study this environment, E896 at the AGS and STAR at RHIC. We have completed our physics running of E896, a search for the H dibaryon and measurement of hyperon production in AuAu collisions, and are in the process of analyzing the data. We have produced the electronics and software for the STAR trigger and will begin to use these tools to search for anti-nuclei and strange hadrons when RHIC turns on later this year

  5. Stable schemes for dissipative particle dynamics with conserved energy

    Energy Technology Data Exchange (ETDEWEB)

    Stoltz, Gabriel, E-mail: stoltz@cermics.enpc.fr

    2017-07-01

    This article presents a new numerical scheme for the discretization of dissipative particle dynamics with conserved energy. The key idea is to reduce elementary pairwise stochastic dynamics (either fluctuation/dissipation or thermal conduction) to effective single-variable dynamics, and to approximate the solution of these dynamics with one step of a Metropolis–Hastings algorithm. This ensures by construction that no negative internal energies are encountered during the simulation, and hence allows to increase the admissible timesteps to integrate the dynamics, even for systems with small heat capacities. Stability is only limited by the Hamiltonian part of the dynamics, which suggests resorting to multiple timestep strategies where the stochastic part is integrated less frequently than the Hamiltonian one.

  6. Effects of a power and photon energy of incident light on near-field etching properties

    Science.gov (United States)

    Yatsui, T.; Saito, H.; Nishioka, K.; Leuschel, B.; Soppera, O.; Nobusada, K.

    2017-12-01

    We developed a near-field etching technique for realizing an ultra-flat surfaces of various materials and structures. To elucidate the near-field etching properties, we have investigated the effects of power and the photon energy of the incident light. First, we established theoretically that an optical near-field with photon energy lower than the absorption edge of the molecules can induce molecular vibrations. We used nanodiamonds to study the power dependence of the near-field etching properties. From the topological changes of the nanodiamonds, we confirmed the linear-dependence of the etching volume with the incident power. Furthermore, we studied the photon energy dependence using TiO2 nanostriped structures, which revealed that a lower photon energy results in a lower etching rate.

  7. Systematics of threshold incident energy for deep sub-barrier fusion hindrance

    International Nuclear Information System (INIS)

    Ichikawa, Takatoshi; Hagino, Kouichi; Iwamoto, Akira

    2007-01-01

    We systematically evaluate the potential energy at the touching configuration for heavy-ion reactions using various potential models. We point out that the energy at the touching point, especially that estimated with the Krappe-Nix-Sierk (KNS) potential, strongly correlates with the threshold incident energy for steep falloff of fusion cross sections observed recently for several systems at extremely low energies. This clearly indicates that the steep fall-off phenomenon can be attributed to the dynamics after the target and projectile touch with each other, e.g., the tunneling process and the nuclear saturation property in the overlap region

  8. Cumulative percent energy deposition of photon beam incident on different targets, simulated by Monte Carlo

    International Nuclear Information System (INIS)

    Kandic, A.; Jevremovic, T.; Boreli, F.

    1989-01-01

    Monte Carlo simulation (without secondary radiation) of the standard photon interactions (Compton scattering, photoelectric absorption and pair protection) for the complex slab's geometry is used in numerical code ACCA. A typical ACCA run will yield: (a) transmission of primary photon radiation differential in energy, (b) the spectrum of energy deposited in the target as a function of position and (c) the cumulative percent energy deposition as a function of position. A cumulative percent energy deposition of photon monoenergetic beam incident on simplest and complexity tissue slab and Fe slab are presented in this paper. (author). 5 refs.; 2 figs

  9. Monte Carlo calculations of energy and angular distributions of transmitted and backscattered neutrons of 15 MeV incident energy

    International Nuclear Information System (INIS)

    Gaber, M.; Faied, A.

    1994-01-01

    The Monte Carlo technique was used to generate both energy and angular distributions of transmitted and backscattered neutrons incident on infinite graphite slabs of thicknesses ranging from 1-90 cm. Point isotropic and parallel beams of 15 MeV neutrons were used. A computer program was developed to simulate collisions by fast neutrons. (author)

  10. Calculation of the effective D-d neutron energy distribution incident on a cylindrical shell sample

    International Nuclear Information System (INIS)

    Gotoh, Hiroshi

    1977-07-01

    A method is proposed to calculate the effective energy distribution of neutrons incident on a cylindrical shell sample placed perpendicularly to the direction of the deuteron beam bombarding a deuterium metal target. The Monte Carlo method is used and the Fortran program is contained. (auth.)

  11. The success of the distorted wave method at very high incident energy

    International Nuclear Information System (INIS)

    Barrette, J.; Berthier, B.; Gastebois, J.

    1986-05-01

    The one-proton and one-neutron direct surface transfer reactions induced by 793 MeV 16 O incident energy beam bombarding a 208 Pb target nucleus, are widely explained by two selection rules contained in the Dirtorted Wave Method formalism

  12. Energy systems evaluation of potential for incidents having health or safety impact

    International Nuclear Information System (INIS)

    Speas, I.G.

    1986-01-01

    The paper discusses the results of safety surveys of Martin Marietta Energy Systems - operated nuclear facilities. The purpose was to identify potential incidents that could cause large numbers of casualties, evaluate existing prevention/response actions, and identify possible improvements. The survey findings indicate the potential for an accident with consequences similar to those at Bhopal, India, is essentially non-existent

  13. High energy electromagnetic particle transportation on the GPU

    Energy Technology Data Exchange (ETDEWEB)

    Canal, P. [Fermilab; Elvira, D. [Fermilab; Jun, S. Y. [Fermilab; Kowalkowski, J. [Fermilab; Paterno, M. [Fermilab; Apostolakis, J. [CERN

    2014-01-01

    We present massively parallel high energy electromagnetic particle transportation through a finely segmented detector on a Graphics Processing Unit (GPU). Simulating events of energetic particle decay in a general-purpose high energy physics (HEP) detector requires intensive computing resources, due to the complexity of the geometry as well as physics processes applied to particles copiously produced by primary collisions and secondary interactions. The recent advent of hardware architectures of many-core or accelerated processors provides the variety of concurrent programming models applicable not only for the high performance parallel computing, but also for the conventional computing intensive application such as the HEP detector simulation. The components of our prototype are a transportation process under a non-uniform magnetic field, geometry navigation with a set of solid shapes and materials, electromagnetic physics processes for electrons and photons, and an interface to a framework that dispatches bundles of tracks in a highly vectorized manner optimizing for spatial locality and throughput. Core algorithms and methods are excerpted from the Geant4 toolkit, and are modified and optimized for the GPU application. Program kernels written in C/C++ are designed to be compatible with CUDA and OpenCL and with the aim to be generic enough for easy porting to future programming models and hardware architectures. To improve throughput by overlapping data transfers with kernel execution, multiple CUDA streams are used. Issues with floating point accuracy, random numbers generation, data structure, kernel divergences and register spills are also considered. Performance evaluation for the relative speedup compared to the corresponding sequential execution on CPU is presented as well.

  14. Chemical Potentials of Quarks Extracted from Particle Transverse Momentum Distributions in Heavy Ion Collisions at RHIC Energies

    International Nuclear Information System (INIS)

    Zhao, Hong; Liu, Fu-Hu

    2014-01-01

    In the framework of a multisource thermal model, the transverse momentum distributions of charged particles produced in nucleus-nucleus (A-A) and deuteron-nucleus (d-A) collisions at relativistic heavy ion collider (RHIC) energies are investigated by a two-component revised Boltzmann distribution. The calculated results are in agreement with the PHENIX experimental data. It is found that the source temperature increases obviously with increase of the particle mass and incident energy, but it does not show an obvious change with the collision centrality. Then, the values of chemical potentials for up, down, and strange quarks can be obtained from the antiparticle to particle yield ratios in a wide transverse momentum range. The relationship between the chemical potentials of quarks and the transverse momentum with different centralities is investigated, too

  15. Method of incident low-energy gamma-ray direction reconstruction in the GAMMA-400 gamma-ray space telescope

    International Nuclear Information System (INIS)

    Kheymits, M D; Leonov, A A; Zverev, V G; Galper, A M; Arkhangelskaya, I V; Arkhangelskiy, A I; Yurkin, Yu T; Bakaldin, A V; Suchkov, S I; Topchiev, N P; Dalkarov, O D

    2016-01-01

    The GAMMA-400 gamma-ray space-based telescope has as its main goals to measure cosmic γ-ray fluxes and the electron-positron cosmic-ray component produced, theoretically, in dark-matter-particles decay or annihilation processes, to search for discrete γ-ray sources and study them in detail, to examine the energy spectra of diffuse γ-rays — both galactic and extragalactic — and to study gamma-ray bursts (GRBs) and γ-rays from the active Sun. Scientific goals of GAMMA-400 telescope require fine angular resolution. The telescope is of a pair-production type. In the converter-tracker, the incident gamma-ray photon converts into electron-positron pair in the tungsten layer and then the tracks are detected by silicon- strip position-sensitive detectors. Multiple scattering processes become a significant obstacle in the incident-gamma direction reconstruction for energies below several gigaelectronvolts. The method of utilising this process to improve the resolution is proposed in the presented work. (paper)

  16. Ion beam sputtering of Ti: Influence of process parameters on angular and energy distribution of sputtered and backscattered particles

    Energy Technology Data Exchange (ETDEWEB)

    Lautenschläger, T. [Leibniz-Institute of Surface Modification, 04318 Leipzig (Germany); Feder, R., E-mail: thomas.lautenschlaeger@iom-leipzig.de [Leibniz-Institute of Surface Modification, 04318 Leipzig (Germany); Neumann, H. [Leibniz-Institute of Surface Modification, 04318 Leipzig (Germany); Rice, C.; Schubert, M. [Department of Electrical and Computer Engineering and Center for Nanohybrid Functional Materials, University of Nebraska-Lincoln, Lincoln, Nebraska 68588-0511 (United States); Bundesmann, C. [Leibniz-Institute of Surface Modification, 04318 Leipzig (Germany)

    2016-10-15

    Highlights: • Ion beam sputter deposition under systematic variation of process parameters. • Angular and energy distribution of secondary particles. • Interaction between incorporated and impinging process gas. • Measured data compared with simulations. - Abstract: In the present study, the influence of ion energy and geometrical parameters onto the angular and energy distribution of secondary particles for sputtering a Ti target with Ar ions is investigated. The angular distribution of the particle flux of the sputtered Ti atoms was determined by the collection method, i.e. by growing Ti films and measuring their thickness. The formal description of the particle flux can be realized by dividing it into an isotropic and an anisotropic part. The experimental data show that increasing the ion energy or decreasing the ion incidence angle lead to an increase of the isotropic part, which is in good agreement with basic sputtering theory. The energy distribution of the secondary ions was measured using an energy-selective mass spectrometer. The energy distribution of the sputtered target ions shows a maximum at an energy between 10 eV and 20 eV followed by a decay proportional to E{sup −n}, which is in principle in accordance with Thompson’s theory, followed by a high energetic tail. When the sum of incidence angle and emission angle is increased, the high-energetic tail expands to higher energies and an additional peak due to direct sputtering events may occur. In the case of backscattered primary Ar ions, a maximum at an energy between 5 eV and 10 eV appears and, depending on the scattering geometry, an additional broad peak at a higher energy due to direct scattering events is observed. The center energy of the additional structure shifts systematically to higher energies with decreasing scattering angle or increasing ion energy. The experimental results are compared to calculations based on simple elastic two-particle-interaction theory and to

  17. Spectroscopy study after quasi-elastic collision in the system 208Pb+232Th at an incident energy of 17 MeV per nucleon

    International Nuclear Information System (INIS)

    Happ, T.

    1989-01-01

    In the present thesis by means of a particle-particle-γ and particle-particle-neutron coincidence experiment γ and neutron spectroscopic studies after quasi-elastic collisions at incident energies far above the Coulomb barrier were performed. For the study of the γ decay by the necessary correction of the Doppler shift the possibility results to study excitations in the projectile and in the target. So in the case of 232 Th beside the observation of the ground state band up to the spin 14 ℎ also a very large number of transitions from vibrational side bands. From the spectra the γ emission probabilities in dependence on the distance of closest approximation were extracted. (orig./HSI) [de

  18. Theory of emission spectra from metal films irradiated by low energy electrons near normal incidence

    International Nuclear Information System (INIS)

    Kretschmann, E.; Callcott, T.A.; Arakawa, E.T.

    1980-01-01

    The emission spectrum produced by low energy electrons incident on a rough metal surface has been calculated for a roughness auto-correlation function containing a prominent peak at a high wave vector. For low energy electrons near normal incidence, the high wavevector peak dominates the roughness coupled surface plasmon radiation (RCSPR) process. The calculation yields estimates of the ratio of RCSPR to transition radiation, the dependence of emission intensity on electron energy and the shape and position of the RCSPR peak. The most interesting result is that the high-wavevector roughness can split the RCSPR radiation into peaks lying above and below the asymptotic surface plasma frequency. The results are compared with data from Ag in the following paper. (orig.)

  19. Energy dependence of ion-induced sputtering yields from monoatomic solids at normal incidence

    International Nuclear Information System (INIS)

    Yamamura, Yasunori; Tawara, Hiro.

    1995-03-01

    The yields of the ion-induced sputtering from monoatomic solids at normal incidence for various ion-target combinations are presented graphically as a function of the incident ion energy. In order to fill the lack of the experimental data, the sputtering yields are also calculated by the Monte Carlo simulation code ACAT for some ion-target combinations. Each graph shows available experimental data points and the ACAT data, together with the sputtering yields calculated by the present empirical formula, whose parameters are determined by the best-fit to available data. (author)

  20. Nuclear energy - Reference beta-particle radiation - Part 2: Calibration fundamentals related to basic quantities characterizing the radiation field

    International Nuclear Information System (INIS)

    2004-01-01

    ISO 6980 consists of the following parts, under the general title Nuclear energy - Reference beta-particle radiation: Part 1: Method of production; Part 2: Calibration fundamentals related to basic quantities characterizing the radiation field; Part 3: Calibration of area and personal dosimeters and determination of their response as a function of energy and angle of incidence. This part 2 of ISO 6980 specifies methods for the measurement of the directional absorbed-dose rate in a tissue-equivalent slab phantom in the ISO 6980 reference beta-particle radiation fields. The energy range of the beta-particle-emitting isotopes covered by these reference radiations is 0.066 to 3.54 MeV (maximum energy). Radiation energies outside this range are beyond the scope of this standard. While measurements in a reference geometry (depth of 0.07 mm at perpendicular incidence in a tissue-equivalent slab phantom) with a reference class extrapolation chamber are dealt with in detail, the use of other measurement systems and measurements in other geometries are also described, although in less detail. The ambient dose equivalent, H*(10) as used for area monitoring of strongly penetrating radiation, is not an appropriate quantity for any beta radiation, even for that penetrating a 10 mm thick layer of ICRU tissue (i.e. E max > 2 MeV). If adequate protection is provided at 0.07 mm, only rarely will one be concerned with other depths, for example 3 mm. This document is geared towards organizations wishing to establish reference-class dosimetry capabilities for beta particles, and serves as a guide to the performance of dosimetry with the reference class extrapolation chamber for beta-particle dosimetry in other fields. Guidance is also provided on the statement of measurement uncertainties

  1. Inelastic collisions of atomic particles at mean energies. Pt.1. Qualitative model of energy losses during a collision

    International Nuclear Information System (INIS)

    Pustovit, A.N.

    2005-01-01

    A new approach is proposed for description of the energy losses of mean-energy atomic particles during their interactions with atomic particles of solids. It is shown that all these interactions are inelastic ones and are determined by different scattering zones with different laws of energy loss dependences [ru

  2. Variation of energy absorption buildup factors with incident photon energy and penetration depth for some commonly used solvents

    Energy Technology Data Exchange (ETDEWEB)

    Singh, Parjit S. [Department of Physics, Punjabi University, Patiala 147 002 (India)], E-mail: dr_parjit@hotmail.com; Singh, Tejbir [Department of Physics, Lovely Professional University, Phagwara 144 402 (India); Kaur, Paramjeet [IAS and Allied Services Training Centre, Punjabi University, Patiala 147 002 (India)

    2008-06-15

    G.P. fitting method has been used to compute energy absorption buildup factor of some commonly used solvents such as acetonitrile (C{sub 4}H{sub 3}N), butanol (C{sub 4}H{sub 9}OH), chlorobenzene (C{sub 6}H{sub 5}Cl), diethyl ether (C{sub 4}H{sub 10}O), ethanol (C{sub 2}H{sub 5}OH), methanol (CH{sub 3}OH), propanol (C{sub 3}H{sub 7}OH) and water (H{sub 2}O) for the wide energy range (0.015-15.0 MeV) up to the penetration depth of 10 mean free path. The variation of energy absorption buildup factor with chemical composition as well as incident photon energy for the selected solvents has been studied. It has been observed that the maximum value of energy absorption buildup factors shifts to the slightly higher incident photon energy with the increase in equivalent atomic number of the solvent and the solvent with least equivalent atomic number possesses the maximum value of energy absorption buildup factor.

  3. Scintillating plastic optical fiber radiation detectors in high energy particle physics

    International Nuclear Information System (INIS)

    Bross, A.D.

    1991-01-01

    We describe the application of scintillating optical fiber in instrumentation for high energy particle physics. The basic physics of the scintillation process in polymers is discussed first and then we outline the fundamentals of scintillating fiber technology. Fiber performance, optimization, and characterization measurements are given. Detector applications in the areas of particle tracking and particle energy determination are then described. 13 refs., 12 figs

  4. Energy spectrum structure and ''trap'' effects in a three-particle system

    International Nuclear Information System (INIS)

    Simenog, I.V.; Sitnichenko, A.I.

    1982-01-01

    Investigation is made of the threshold energy spectrum structure in a system of three spinless particles depending on the form of two-particle interaction. The correlation dependence of the spectrum and low-energy scattering parameters are shown. A new phenomenon of ''traps'' for the spectrum in a three-particle system with interaction involving components of considerably different ranges is established

  5. [High energy particle physics at Purdue, 1989--1990

    International Nuclear Information System (INIS)

    Gaidos, J.A.; Loeffler, F.J.; McIlwain, R.L.; Miller, D.H.; Palfrey, T.R.; Shibata, E.I.; Shipsey, I.P.

    1990-05-01

    The theoretical and experimental high energy physics program is reviewed, including developments on particle detectors. Among the topics addressed are the following: the CLEO experiment; gamma ray astrophysics; highest-weight representations of affine Kac-Moody algebras; supersymmetric field theories; parity- violating effects and superconductivity in 2 + 1 dimensional supersymmetric QED; neutrino oscillations with applications to solar and supernova neutrinos; a search for the quark-gluon plasma using the Fermilab collider; the Solenoid Detector Collaboration at SSC; the high-resolution vertex chamber at TRISTAN; CP violation in e + e - →φ→K L K S ; deviations from Coulomb's Law; and the electric charge and equations of state of neutron stars

  6. High-energy collisions of particles, strings, and branes

    CERN Document Server

    Veneziano, Gabriele

    2015-01-01

    This chapter summarizes some 25 years of work on the transplanckian-energy collisions of particles, strings, and branes, seen as a theoretical laboratory for understanding how gravity and quantum mechanics can be consistently combined in string theory. The ultimate aim of the exercise is to understand whether and how a consistent quantization of gravity can solve some longstanding paradoxes, such as the apparent loss of information in the production and decay of black holes at a semiclassical level. Considerable progress has been made in understanding the emergence of General Relativity expectations and in evaluating several kinds of quantum string corrections to them in the weak-gravity regime while keeping unitarity manifest. While some progress has also been made in the strong-gravity/gravitational collapse domain, full control of how unitarity works in that regime is still lacking.

  7. Some characteristics of the CR-39 solid state nuclear - Track Detector for register of protons and low energy alpha particles

    International Nuclear Information System (INIS)

    Fonseca, E.S. da.

    1983-01-01

    Experimental results related to registration properties of the CR-39 Solid State Nuclear Track Detector for charged particles are presented and discussed. The existence of an inverse proportion between the induction time and the temperature as well as normal concentration of solutions, is showed by the study of CR-39 chemical etching characteristics in NaOH and KOH solutions, comprising varied concentration and temperature. The bulk-etch rate and activation energy of the process were obtained. The critical energy and critical energy-loss rate of CR-39 track-detectors for registration of protons were experimentally determined. Samples were exposed to 24 Mev proton beams in the IEN/CNEN Cyclotron (CV-28), using scattering chamber with a tantalum thin target and aluminium absorbers in contact with the samples, in order to provide the required fluctuation in the scattered beam energy. From the mean track-diameter plotted against incident proton energy the critical energy was obtained. From the calculated energy-loss rate vs. energy curve, the critical energy loss rate were evaluated. The CR-39 response for low energy alpha particles (E = 7h) under the conditions of 6.25 N NaOH at 70 0 C. It is shown that successive chemical etchings do not produce the same track geometry as obtained by means of a continous revelation with the same total etching time. (Author) [pt

  8. High-Energy Solar Particle Events in Cycle 24

    Science.gov (United States)

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

    2015-01-01

    The Sun is already in the declining phase of cycle 24, but the paucity of high-energy solar energetic particle (SEP) events continues with only two ground level enhancement (GLE) events as of March 31, 2015. In an attempt to understand this, we considered all the large SEP events of cycle 24 that occurred until the end of 2014. We compared the properties of the associated CMEs with those in cycle 23. We found that the CME speeds in the sky plane were similar, but almost all those cycle-24 CMEs were halos. A significant fraction of (16%) of the frontside SEP events were associated with eruptive prominence events. CMEs associated with filament eruption events accelerate slowly and attain peak speeds beyond the typical GLE release heights. When we considered only western hemispheric events that had good connectivity to the CME nose, there were only 8 events that could be considered as GLE candidates. One turned out to be the first GLE event of cycle 24 (2012 May 17). In two events, the CMEs were very fast (>2000 km/s) but they were launched into a tenuous medium (high Alfven speed). In the remaining five events, the speeds were well below the typical GLE CME speed (2000 km/s). Furthermore, the CMEs attained their peak speeds beyond the typical heights where GLE particles are released. We conclude that several factors contribute to the low rate of high-energy SEP events in cycle 24: (i) reduced efficiency of shock acceleration (weak heliospheric magnetic field), (ii) poor latitudinal and longitudinal connectivity), and (iii) variation in local ambient conditions (e.g., high Alfven speed).

  9. Analysis of incident-energy dependence of delayed neutron yields in actinides

    Energy Technology Data Exchange (ETDEWEB)

    Nasir, Mohamad Nasrun bin Mohd, E-mail: monasr211@gmail.com; Metorima, Kouhei, E-mail: kohei.m2420@hotmail.co.jp; Ohsawa, Takaaki, E-mail: ohsawa@mvg.biglobe.ne.jp; Hashimoto, Kengo, E-mail: kengoh@pp.iij4u.or.jp [Graduate School of Science and Engineering, Kindai University, Kowakae, Higashi-Osaka, 577-8502 (Japan)

    2015-04-29

    The changes of delayed neutron yields (ν{sub d}) of Actinides have been analyzed for incident energy up to 20MeV using realized data of precursor after prompt neutron emission, from semi-empirical model, and delayed neutron emission probability data (P{sub n}) to carry out a summation method. The evaluated nuclear data of the delayed neutron yields of actinide nuclides are still uncertain at the present and the cause of the energy dependence has not been fully understood. In this study, the fission yields of precursor were calculated considering the change of the fission fragment mass yield based on the superposition of fives Gaussian distribution; and the change of the prompt neutrons number associated with the incident energy dependence. Thus, the incident energy dependent behavior of delayed neutron was analyzed.The total number of delayed neutron is expressed as ν{sub d}=∑Y{sub i} • P{sub ni} in the summation method, where Y{sub i} is the mass yields of precursor i and P{sub ni} is the delayed neutron emission probability of precursor i. The value of Y{sub i} is derived from calculation of post neutron emission mass distribution using 5 Gaussian equations with the consideration of large distribution of the fission fragments. The prompt neutron emission ν{sub p} increases at higher incident-energy but there are two different models; one model says that the fission fragment mass dependence that prompt neutron emission increases uniformly regardless of the fission fragments mass; and the other says that the major increases occur at heavy fission fragments area. In this study, the changes of delayed neutron yields by the two models have been investigated.

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

    Science.gov (United States)

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

    1989-01-01

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

  11. Angular momentum and incident-energy dependence of nucleus-nucleus interaction

    International Nuclear Information System (INIS)

    Yamaguchi, S.

    1991-01-01

    The purpose of this paper is to understand intuitively the origin of the angular momentum and incident-energy dependence of the nucleus-nucleus interaction on the basis of the totally- antisymmetrized many-body theory. With the aim of understanding the structure of the nucleus-nucleus interaction, we show first that the nucleus-nucleus interaction can be written by the use of the density-distribution function and the phase-space distribution function instead of using the many-body wave function itself. And we show that the structure change of the density-distribution function with the increase of the angular momentum causes the angular momentum dependence of the nucleus-nucleus interaction and that the incident-energy dependence of the nucleus-nucleus interaction originates from the structure change of the phase-space distribution function

  12. Measurement of neutron-production double-differential cross sections for intermediate energy pion incident reaction

    International Nuclear Information System (INIS)

    Iwamoto, Yosuke; Shigyo, Nobuhiro; Satoh, Daiki

    2002-01-01

    Neutron-production double-differential cross sections for 870-MeV π + and π - and 2.1-GeV π + mesons incident on iron and lead targets were measured with NE213 liquid scintillators by time-of-flight technique. NE213 liquid scintillators 12.7 cm in diameter and 12.7 cm thick were placed in directions of 15, 30, 60, 90, 120 and 150deg. The typical flight path length was 15 m. Neutron detection efficiencies were derived from the calculation results of SCINFUL and CECIL codes. The experimental results were compared with the JAM code. The double differential cross sections calculated by the JAM code disagree with experimental data at neutron energies below about 30 MeV. JAM overestimates π + -incident neutron-production cross sections in forward angles at neutron energies of 100 to 500 MeV. (author)

  13. Experimental Studies of Elementary Particle Interactions at High Energies

    Energy Technology Data Exchange (ETDEWEB)

    Goulianos, Konstantin [Rockefeller Univ., New York, NY (United States)

    2013-07-30

    This is the final report of a program of research on "Experimental Studies of Elementary Particle Interactions at High Energies'' of the High Energy Physics (HEP) group of The Rockefeller University. The research was carried out using the Collider Detector at Fermilab (CDF) and the Compact Muon Solenoid (CMS) detector at the Large Hadron Collider (LHC) at CERN. Three faculty members, two research associates, and two postdoctoral associates participated in this project. At CDF, we studied proton-antiproton collisions at an energy of 1.96 TeV. We focused on diffractive interactions, in which the colliding antiproton loses a small fraction of its momentum, typically less than 1%, while the proton is excited into a high mass state retaining its quantum numbers. The study of such collisions provides insight into the nature of the diffractive exchange, conventionally referred to as Pomeron exchange. In studies of W and Z production, we found results that point to a QCD-based interpretation of the diffractive exchange, as predicted in a data-driven phenomenology developed within the Rockefeller HEP group. At CMS, we worked on diffraction, supersymmetry (SUSY), dark matter, large extra dimensions, and statistical applications to data analysis projects. In diffraction, we extended our CDF studies to higher energies working on two fronts: measurement of the single/double diffraction and of the rapidity gap cross sections at 7 TeV, and development of a simulation of diffractive processes along the lines of our successful model used at CDF. Working with the PYTHIA8 Monte Carlo simulation authors, we implemented our model as a PYTHIA8-MBR option in PYTHIA8 and used it in our data analysis. Preliminary results indicate good agreement. We searched for SUSY by measuring parameters in the Constrained Minimal Supersymmetric extension of the Standard Model (CMSSM) and found results which, combined with other experimental constraints and theoretical considerations, indicate

  14. Nucleation of diindenoperylene and pentacene at thermal and hyperthermal incident kinetic energies

    Energy Technology Data Exchange (ETDEWEB)

    Kish, Edward R.; Desai, Tushar V.; Greer, Douglas R.; Engstrom, James R., E-mail: jre7@cornell.edu [School of Chemical and Biomolecular Engineering, Cornell University, Ithaca, New York 14853 (United States); Woll, Arthur R. [Cornell High Energy Synchrotron Source, Cornell University, Ithaca, New York 14853 (United States)

    2015-05-15

    The authors have examined the nucleation of diindenoperylene (DIP) on SiO{sub 2} employing primarily atomic force microscopy and focusing on the effect of incident kinetic energy employing both thermal and supersonic sources. For all incident kinetic energies examined (E{sub i} = 0.09–11.3 eV), the nucleation of DIP is homogeneous and the dependence of the maximum island density on the growth rate is described by a power law. A critical nucleus of approximately two molecules is implicated by our data. A re-examination of the nucleation of pentacene on SiO{sub 2} gives the same major result that the maximum island density is determined by the growth rate, and it is independent of the incident kinetic energy. These observations are readily understood by factoring in the size of the critical nucleus in each case, and the island density, which indicates that diffusive transport of molecules to the growing islands dominate the dynamics of growth in the submonolayer regime.

  15. Total cross-sections for reactions of high energy particles (including elastic, topological, inclusive and exclusive reactions). Subvol. b

    International Nuclear Information System (INIS)

    Schopper, H.; Moorhead, W.G.; Morrison, D.R.O.

    1988-01-01

    The aim of this report is to present a compilation of cross-sections (i.e. reaction rates) of elementary particles at high energy. The data are presented in the form of tables, plots and some fits, which should be easy for the reader to use and may enable him to estimate cross-sections for presently unmeasured energies. We have analyzed all the data published in the major Journals and Reviews for momenta of the incoming particles larger than ≅ 50 MeV/c, since the early days of elementary particle physics and, for each reaction, we have selected the best cross-section data available. We have restricted our attention to integrated cross-sections, such as total cross-sections, exclusive and inclusive cross-sections etc., at various incident beam energies. We have disregarded data affected by geometrical and/or kinematical cuts which would make them not directly comparable to other data at different energies. Also, in the case of exclusive reactions, we have left out data where not all of the particles in the final state were unambiguously identified. This work contains reactions induced by neutrinos, gammas, charged pions, kaons, nucleons, antinucleons and hyperons. (orig./HSI)

  16. Planning the Future of U.S. Particle Physics (Snowmass 2013): Chapter 3: Energy Frontier

    Energy Technology Data Exchange (ETDEWEB)

    Brock, R.; et al.

    2014-01-23

    These reports present the results of the 2013 Community Summer Study of the APS Division of Particles and Fields ("Snowmass 2013") on the future program of particle physics in the U.S. Chapter 3, on the Energy Frontier, discusses the program of research with high-energy colliders. This area includes experiments on the Higgs boson, the electroweak and strong interactions, and the top quark. It also encompasses direct searches for new particles and interactions at high energy.

  17. Spatial variations in ambient ultrafine particle concentrations and the risk of incident prostate cancer: A case-control study.

    Science.gov (United States)

    Weichenthal, Scott; Lavigne, Eric; Valois, Marie-France; Hatzopoulou, Marianne; Van Ryswyk, Keith; Shekarrizfard, Maryam; Villeneuve, Paul J; Goldberg, Mark S; Parent, Marie-Elise

    2017-07-01

    Diesel exhaust contains large numbers of ultrafine particles (UFPs, <0.1µm) and is a recognized human carcinogen. However, epidemiological studies have yet to evaluate the relationship between UFPs and cancer incidence. We conducted a case-control study of UFPs and incident prostate cancer in Montreal, Canada. Cases were identified from all main Francophone hospitals in the Montreal area between 2005 and 2009. Population controls were identified from provincial electoral lists of French Montreal residents and frequency-matched to cases using 5-year age groups. UFP exposures were estimated using a land use regression model. Exposures were assigned to residential locations at the time of diagnosis/recruitment as well as approximately 10-years earlier to consider potential latency between exposure and disease onset. Odds ratios (OR) and 95% confidence intervals (95% CI) were calculated per interquartile range (IQR) increase in UFPs (approximately 4000 particles/cm 3 ) using logistic regression models adjusting for individual-level and ecological covariates. Ambient UFP concentrations were associated with an increased risk of prostate cancer (OR=1.10, 95% CI: 1.01, 1.19) in fully adjusted models when exposures were assigned to residences 10-years prior to diagnosis. This risk estimate increased slightly (OR=1.17, 95% CI; 1.01, 1.35) when modeled as a non-linear natural spline function. A smaller increased risk (OR=1.04, 95% CI: 0.97, 1.11) was observed when exposures were assigned to residences at the time of diagnosis. Exposure to ambient UFPs may increase the risk of prostate cancer. Future studies are needed to replicate this finding as this is the first study to evaluate this relationship. Crown Copyright © 2017. Published by Elsevier Inc. All rights reserved.

  18. Pseudorapidity distributions of charged particles in Pb-Pb collisions at super proton synchrotron energies from the NA50 experiment

    CERN Document Server

    Idzik, M; Alessandro, B; Alexa, C; Arnaldi, R; Atayan, M; Baglin, C; Baldit, A; Bedjidian, Marc; Beolè, S; Boldea, V; Bordalo, P; Borges, G; Bussière, A; Capelli, L; Castanier, C; Castor, J I; Chaurand, B; Chevrot, I; Cheynis, B; Chiavassa, E; Cicalò, C; Claudino, T; Comets, M P; Constans, N; Constantinescu, S; Cortese, P; De Falco, A; De Marco, N; Dellacasa, G; Devaux, A; Dita, S; Drapier, O; Ducroux, L; Espagnon, B; Fargeix, J; Force, P; Gallio, M; Gavrilov, Yu K; Gerschel, C; Giubellino, P; Golubeva, M B; Gonin, M; Grigorian, A A; Grigorian, S; Grossiord, J Y; Guber, F F; Guichard, A; Gulkanian, H R; Hakobyan, R S; Haroutunian, R; Jouan, D; Karavitcheva, T L; Kluberg, L; Kurepin, A B; Le Bornec, Y; Lourenço, C; MacCormick, M; Macciotta, P; Marzari-Chiesa, A; Masera, M; Masoni, A; Monteno, M; Musso, A; Petiau, P; Piccotti, A; Pizzi, J R; Prado da Silva, W L; Prino, F; Puddu, G; Quintans, C; Ramello, L; Ramos, S; Rato-Mendes, P; Riccati, L; Romana, A; Santos, H; Saturnini, P; Scalas, E; Scomparin, E; Serci, S; Shahoyan, R; Sigaudo, F; Silva, S; Sitta, M; Sonderegger, P; Tarrago, X; Topilskaya, N S; Usai, G L; Vercellin, Ermanno; Villatte, L; Willis, N

    2003-01-01

    We present the measurements of charged particle pseudorapidity distributions dN/sub ch//d eta performed by the NA50 experiment in Pb-Pb collisions at the CERN SPS. Measurements were done at incident energies of 40 GeV ( square root s = 8.77 GeV) and 158 GeV ( square root s = 17.3 GeV) per nucleon over a broad impact parameter range. The multiplicity distributions are studied as a function of centrality using the number of participating nucleons (N/sub part/), or the number of binary nucleon-nucleon collisions (N/sub coll/). Their values at midrapidity exhibit a linear scaling with N/sub part/ at both energies. Particle yield increases approximately by a factor of 2 between square root s = 8.77 GeV and square root s = 17.3 GeV. (5 refs).

  19. High-energy charged particle bursts in the near-Earth space as earthquake precursors

    Directory of Open Access Journals (Sweden)

    S. Yu. Aleksandrin

    2003-02-01

    Full Text Available The experimental data on high-energy charged particle fluxes, obtained in various near-Earth space experiments (MIR orbital station, METEOR-3, GAMMA and SAMPEX satellites were processed and analyzed with the goal to search for particle bursts. Particle bursts have been selected in every experiment considered. It was shown that the significant part of high-energy charged particle bursts correlates with seismic activity. Moreover, the particle bursts are observed several hours before strong earthquakes; L-shells of particle bursts and corresponding earthquakes are practically the same. Some features of a seismo-magnetosphere connection model, based on the interaction of electromagnetic emission of seismic origin and radiation belt particles, were considered. Key words. Ionospheric physics (energetic particles, trapped; energetic particles, precipitating; magnetosphere-ionosphere interactions

  20. PREFACE: High Energy Particle Physics Workshop (HEPPW2015)

    Science.gov (United States)

    Cornell, Alan S.; Mellado, B.

    2015-10-01

    The motivation for this workshop began with the discovery of the Higgs boson three years ago, and the realisation that many problems remain in particle physics, such as why there is more matter than anti-matter, better determining the still poorly measured parameters of the strong force, explaining possible sources for dark matter, naturalness etc. While the newly discovered Higgs boson seems to be compatible with the Standard Model, current experimental accuracy is far from providing a definitive statement with regards to the nature of this new particle. There is a lot of room for physics beyond the Standard Model to emerge in the exploration of the Higgs boson. Recent measurements in high-energy heavy ion collisions at the LHC have shed light on the complex dynamics that govern high-density quark-gluon interactions. An array of results from the ALICE collaboration have been highlighted in a recent issue of CERN courier. The physics program of high-energy heavy ion collisions promises to further unveil the intricacies of high-density quark-gluon plasma physics. The great topicality of high energy physics research has also seen a rapid increase in the number of researchers in South Africa pursuing such studies, both experimentally through the ATLAS and ALICE colliders at CERN, and theoretically. Young researchers and graduate students largely populate these research groups, with little experience in presenting their work, and few support structures (to their knowledge) to share experiences with. Whilst many schools and workshops have sought to educate these students on the theories and tools they will need to pursue their research, few have provided them with a platform to present their work. As such, this workshop discussed the various projects being pursued by graduate students and young researchers in South Africa, enabling them to develop networks for future collaboration and discussion. The workshop took place at the iThemba Laboratories - North facility, in

  1. Compact and energy saving magnet technology for particle accelerators

    International Nuclear Information System (INIS)

    Baurichter, A.

    2013-01-01

    Despite the fact that funding agencies and industrial users of particle accelerators get more and more alerted about costs of civil engineering, installation and operation, only little effort has been put into development of sustainable, energy and cost saving accelerator technology. In order to reduce the total-cost-of ownership of accelerator magnets, operating at high electrical power for twenty years or more, permanent magnet based Green Magnet technology has been developed at a consortium around Danfysik's R and D team. Together with our partners from ISA, Aarhus University, the Aarhus School of Engineering, the company Sintex and Aalborg University all obstacles in applying permanent magnet technology as e.g. thermal drift and inhomogeneities of magnetic fields have been overcome. The first Green Magnet has now been operated for more than half a year in an Accelerator Mass Spectrometry facility at the ETH in Zurich. The performance of this B=0.43T 90 deg. H-type bending magnet and the most recently builtB=1T, 30 deg. C-type Green Magnet for the synchrotron light source ASTRID2 at ISA in Aarhus will be presented. Danfysik also is designing, manufacturing and testing 60 compact magnet systems, developed at MAX-Lab for the new MAXIV 3.0 GeV synchrotron light source. In addition, 12 for the 1.5 GeV light source and another 12 for the new SOLARIS light source in Krakow, Poland are buying built. Up to a dozen or more magnet functions have been integrated into one yoke of these compact magnet systems, which makes the new MAXIV light sources compact, energy saving and at the same time very bright. Test results and design concepts of the new MAXIV and SOLARIS magnets will be presented. (author)

  2. Hadron production in high energy muon scattering. [Quark-parton model, 225 GeV, structure functions, particle ratios

    Energy Technology Data Exchange (ETDEWEB)

    Hicks, R.G.

    1978-01-01

    An experiment was performed to study muon-proton scattering at an incident energy of 225 GeV and a total effective flux of 4.3 x 10/sup 10/ muons. This experiment is able to detect charged particles in coincidence with the scattered muon in the forward hemisphere, and results are reported for the neutral strange particles K/sub s//sup 0/ and ..lambda../sup 0/ decaying into two charged particles. Within experimental limits the masses and lifetimes of these particles are consistent with previous measurements. The distribution of hadrons produced in muon scattering is determined, measuring momentum components parallel and transverse to the virtual photon direction, and these distributions are compared to other high energy experiments involving the scattering of pions, protons, and neutrinos from protons. Structure functions for hadron production and particle ratios are calculated. No azimuthal dependence is observed, and lambda production does not appear to be polarized. The physical significance of the results is discussed within the framework of the quark-parton model. 29 references.

  3. Free-Free Transitions in the Presence of Laser Fields at Very Low Incident Electron Energy

    Science.gov (United States)

    Bhatia, A. K.; Sinha, Chandana

    2010-01-01

    We study the free-free transition in electron-hydrogenic systems in ground state in presence of an external laser field at very loud incident energies. The laser field is treated classically while the collision dynamics is treated quantum mechanically. The laser field is chosen to be monochromatic, linearly polarized and homogeneous. The incident electron is considered to be dressed by the laser in a nonperturbative manner by choosing a Volkov wave function for it. The scattering weave function for the electron is solved numerically by taking into account the effect of the electron exchange, short-range as well as of the long-range interactions to get the S and P wave phase shifts while for the higher angular momentum phase shifts the exchange approximation has only been considered. We calculate the laser assisted differential cross sections (LADCS) for the aforesaid free-free transition process for single photon absorption/emission. The laser intensity is chosen to be much less than the atomic field intensity. A strong suppression is noted in the LADCS as compared to the field free (FF) cross sections. Unlike the FF ones, the LADCS exhibit some oscillations having a distinct maximum at a low value of the scattering angle depending on the laser parameters as well as on the incident energies.

  4. Review of lattice results concerning low-energy particle physics

    International Nuclear Information System (INIS)

    Aoki, S.; Aoki, Y.; Brookhaven National Laboratory, Upton, NY; Becirevic, D.

    2016-07-01

    We review lattice results related to pion, kaon, D- and B-meson physics with the aim of making them easily accessible to the particle physics community. More specifically, we report on the determination of the light-quark masses, the form factor f_+(0), arising in the semileptonic K→π transition at zero momentum transfer, as well as the decay constant ratio f_K/f_π and its consequences for the CKM matrix elements V_u_s and V_u_d. Furthermore, we describe the results obtained on the lattice for some of the low-energy constants of SU(2)_L x SU(2)_R and SU(3)_L x SU(3)_R Chiral Perturbation Theory. We review the determination of the B_K parameter of neutral kaon mixing as well as the additional four B parameters that arise in theories of physics beyond the Standard Model. The latter quantities are an addition compared to the previous review. For the heavy-quark sector, we provide results for m_c and m_b (also new compared to the previous review), as well as those for D- and B-meson decay constants, form factors, and mixing parameters. These are the heavy-quark quantities most relevant for the determination of CKM matrix elements and the global CKM unitarity-triangle fit. Finally, we review the status of lattice determinations of the strong coupling constant α_s.

  5. Pore size determination from charged particle energy loss measurement

    International Nuclear Information System (INIS)

    Brady, F.P.; Armitage, B.H.

    1977-01-01

    A new method aimed at measuring porosity and mean pore size in materials has been developed at Harwell. The energy width or variance of a transmitted or backscattered charged particle beam is measured and related to the mean pore size via the assumption that the variance in total path length in the porous material is given by (Δx 2 )=na 2 , where n is the mean number of pores and a the mean pore size. It is shown on the basis of a general and rigorous theory of total path length distribution that this approximation can give rise to large errors in the mean pore size determination particularly in the case of large porosities (epsilon>0.5). In practice it is found that it is not easy to utilize fully the general theory because accurate measurements of the first four moments are required to determine the means and variances of the pore and inter-pore length distributions. Several models for these distributions are proposed. When these are incorporated in the general theory the determinations of mean pore size from experimental measurements on powder samples are in good agreement with values determined by other methods. (Auth.)

  6. Review of lattice results concerning low-energy particle physics

    Energy Technology Data Exchange (ETDEWEB)

    Aoki, S. [Kyoto University, Yukawa Institute for Theoretical Physics, Kyoto (Japan); Aoki, Y. [Nagoya University, Kobayashi-Maskawa Institute for the Origin of Particles and the Universe (KMI), Nagoya (Japan); Brookhaven National Laboratory, RIKEN BNL Research Center, Upton, NY (United States); Bernard, C. [Washington University, Department of Physics, Saint Louis, MO (United States); Blum, T. [Brookhaven National Laboratory, RIKEN BNL Research Center, Upton, NY (United States); University of Connecticut, Physics Department, Storrs, CT (United States); Colangelo, G.; Leutwyler, H.; Necco, S.; Wenger, U. [Institut fuer theoretische Physik, Universitaet Bern, Albert Einstein Center for Fundamental Physics, Bern (Switzerland); Della Morte, M. [University of Southern Denmark, CP3-Origins and Danish IAS, Odense M (Denmark); IFIC (CSIC), Paterna (Spain); Duerr, S. [Bergische Universitaet Wuppertal, Wuppertal (Germany); Juelich Supercomputing Center, Juelich (Germany); El-Khadra, A.X. [University of Illinois, Department of Physics, Urbana, IL (United States); Fukaya, H.; Onogi, T. [Osaka University, Department of Physics, Osaka (Japan); Horsley, R. [University of Edinburgh, School of Physics, Edinburgh (United Kingdom); Juettner, A.; Sachrajda, C.T. [University of Southampton, School of Physics and Astronomy, Southampton (United Kingdom); Kaneko, T. [High Energy Accelerator Research Organization (KEK), Ibaraki (Japan); Laiho, J. [University of Glasgow, SUPA, Department of Physics and Astronomy, Glasgow (United Kingdom); Syracuse University, Department of Physics, Syracuse, New York (United States); Lellouch, L. [Aix-Marseille Universite, CNRS, CPT, UMR 7332, Marseille (France); Universite de Toulon, CNRS, CPT, UMR 7332, La Garde (France); Lubicz, V. [Universita Roma Tre, Dipartimento di Matematica e Fisica, Rome (Italy); Sezione di Roma Tre, INFN, Rome (Italy); Lunghi, E. [Indiana University, Physics Department, Bloomington, IN (United States); Pena, C. [Universidad Autonoma de Madrid, Instituto de Fisica Teorica UAM/CSIC and Departamento de Fisica Teorica, Madrid (Spain); Sharpe, S.R. [University of Washington, Physics Department, Seattle, WA (United States); Simula, S. [Sezione di Roma Tre, INFN, Rome (Italy); Sommer, R. [NIC rate at DESY, Zeuthen (Germany); Water, R.S.V. de [Fermi National Accelerator Laboratory, Batavia, IL (United States); Vladikas, A. [Universita di Roma Tor Vergata, INFN, Sezione di Tor Vergata, c/o Dipartimento di Fisica, Rome (Italy); Wittig, H. [University of Mainz, PRISMA Cluster of Excellence, Institut fuer Kernphysik and Helmholtz Institute Mainz, Mainz (Germany); Collaboration: FLAG Working Group

    2014-09-15

    We review lattice results related to pion, kaon, D- and B-meson physics with the aim of making them easily accessible to the particle-physics community. More specifically, we report on the determination of the lightquark masses, the form factor f{sub +}(0), arising in semileptonic K → π transition at zero momentum transfer, as well as the decay-constant ratio f{sub K}/f{sub π} of decay constants and its consequences for the CKM matrix elements V{sub us} and V{sub ud}. Furthermore, we describe the results obtained on the lattice for some of the low-energy constants of SU(2){sub L} x SU(2){sub R} andSU(3)L{sub L} x SU(3){sub R} Chiral Perturbation Theory and review the determination of the BK parameter of neutral kaon mixing. The inclusion of heavy-quark quantities significantly expands the FLAG scope with respect to the previous review. Therefore, we focus here on D- and B-meson decay constants, form factors, and mixing parameters, since these are most relevant for the determination of CKM matrix elements and the global CKM unitarity-triangle fit. In addition we review the status of lattice determinations of the strong coupling constant α{sub s}. (orig.)

  7. Proper surface channelling of low energy argon ions incident on a nickel (110) crystal

    International Nuclear Information System (INIS)

    Evdokimov, I.N.; Berg, J.A. van den; Armour, D.G.

    1979-01-01

    The scattering behaviour of 6 keV argon ions from a nickel (110) surface has been investigated for specular reflection under grazing incidence conditions. The occurrence of an anomalously high energy loss has been confirmed and the transition from chain scattering at large scattering angles to a distinctly different type of scattering at small angles has been investigated. The characteristics of the low angle scattering phenomena, which dominate the observed spectra at scattering angles below about 18 0 , may be explained in terms of a surface hyperchannelling model in which the incident ions are confined to move within the shallow 'potential valleys' between two atomic rows in the surface. The critical angle for occurrence of this phenomena which is distinctly different from surface semichannelling has been evaluated with Lindhard's standard string potential. The experimentally measured critical angles are in good agreement with the calculated ones. (author)

  8. Is the development of nuclear energy likely to increase the incidence of genetic diseases for mankind

    International Nuclear Information System (INIS)

    Leonard, A.

    1976-01-01

    In a normal human population a relatively high number of individuals (+10%) are bearing genetic and chromosomal deficiencies. As a result of the difficulties encountered when carrying out valid epidemiological investigations, the observations made on the descent of irradiated subjects have not demonstrated that an exposure for a man to ionizing radiations increases the incidence of his deficiencies. That explains the need of having to use the results of experiments conducted on animals in order to evaluate this kind of hazard for mankind. The analysis of these experimental data allows us to conclude that under normal conditions of exploitation the expected development of the nuclear energy is not likely to increase significantly the incidence of genetic deficiencies for mankind. (G.C.)

  9. UCLA Intermediate Energy Nuclear and Particle Physics Research: Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Nefkens, B M.K. [Principal Investigator, ed.; Goetz, J; Lapik, A; Korolija, M; Prakhov, S; Starostin, A [ed.

    2011-05-18

    This project covers the following research: (a) Investigations into the structure of the proton and neutron. This is done by investigating the different resonance states of nucleons with beams of tagged, polarized photons, linearly as well as circularly, incident on polarized hydrogen/deuterium targets and measuring the production of {pi}{sup 0}, 2{pi}{sup }0, 3{pi}{sup 0}, {eta} , {eta}', {omega}, etc. The principal detector is the Crystal Ball multiphoton spectrometer which has an acceptance of nearly 4 . It has been moved to the MAMI accelerator facility of the University of Mainz, Germany. We investigate the conversion of electromagnetic energy into mesonic matter and conversely. (b) We investigate the consequences of applying the "standard" symmetries of isospin, G-parity, charge conjugation, C, P, T, and chirality using rare and forbidden decays of light mesons such as the {eta} ,{eta}' and {omega}. We also investigate the consequences of these symmetries being slightly broken symmetries. We do this by studying selected meson decays using the Crystal Ball detector. (c) We determine the mass, or more precisely the mass difference of the three light quarks (which are inputs to Quantum Chromodynamics) by measuring the decay rate of specially selected {eta} and {eta}' decay modes, again we use the Crystal Ball. (d)We have started a new program to search for the 33 missing cascade baryons using the CLAS detector at the Thomas Jefferson Laboratory. Cascade resonances are very special: they have double strangeness and are quite narrow. This implies that they can be discovered by the missing mass technique in photoproduction reactions such as in {gamma}p{yields}{Xi}{sup}K{sup +}K{sup +}. The cascade program is of particular importance for the upgrade to 12 GeV of the CLAS detector and for design of the Hall D at JLab. (e) Finally, we are getting more involved in a new program to measure the hadronic matter form factor of complex nuclei, in particular

  10. Simulation of deterministic energy-balance particle agglomeration in turbulent liquid-solid flows

    Science.gov (United States)

    Njobuenwu, Derrick O.; Fairweather, Michael

    2017-08-01

    An efficient technique to simulate turbulent particle-laden flow at high mass loadings within the four-way coupled simulation regime is presented. The technique implements large-eddy simulation, discrete particle simulation, a deterministic treatment of inter-particle collisions, and an energy-balanced particle agglomeration model. The algorithm to detect inter-particle collisions is such that the computational costs scale linearly with the number of particles present in the computational domain. On detection of a collision, particle agglomeration is tested based on the pre-collision kinetic energy, restitution coefficient, and van der Waals' interactions. The performance of the technique developed is tested by performing parametric studies on the influence of the restitution coefficient (en = 0.2, 0.4, 0.6, and 0.8), particle size (dp = 60, 120, 200, and 316 μm), Reynolds number (Reτ = 150, 300, and 590), and particle concentration (αp = 5.0 × 10-4, 1.0 × 10-3, and 5.0 × 10-3) on particle-particle interaction events (collision and agglomeration). The results demonstrate that the collision frequency shows a linear dependency on the restitution coefficient, while the agglomeration rate shows an inverse dependence. Collisions among smaller particles are more frequent and efficient in forming agglomerates than those of coarser particles. The particle-particle interaction events show a strong dependency on the shear Reynolds number Reτ, while increasing the particle concentration effectively enhances particle collision and agglomeration whilst having only a minor influence on the agglomeration rate. Overall, the sensitivity of the particle-particle interaction events to the selected simulation parameters is found to influence the population and distribution of the primary particles and agglomerates formed.

  11. Search for a particle with a long interaction length. [particle mandela to explain anomalous energy spectra at mountain altitude

    Science.gov (United States)

    Barrowes, S. C.; Huggett, R. W.; Jones, W. V.; Levit, L. B.; Porter, L. G.

    1975-01-01

    A search has been carried out for a long-lived particle having an interaction length lambda sub m equals 300 to 2000 gm/sq cm in air. Such a particle, called the mandela, has been proposed to explain an anomalous energy spectrum of particles observed near sea level with a shallow spectrometer. Data taken at mountain altitude with a deep spectrometer has been examined for compatibility with the existence of the mandela. Although data tend to favor the mandela hypothesis the results are not conclusive and appear to be explainable by conventional means.

  12. High-energy particle production in solar flares (SEP, gamma-ray and neutron emissions). [solar energetic particles

    Science.gov (United States)

    Chupp, E. L.

    1987-01-01

    Electrons and ions, over a wide range of energies, are produced in association with solar flares. Solar energetic particles (SEPs), observed in space and near earth, consist of electrons and ions that range in energy from 10 keV to about 100 MeV and from 1 MeV to 20 GeV, respectively. SEPs are directly recorded by charged particle detectors, while X-ray, gamma-ray, and neutron detectors indicate the properties of the accelerated particles (electrons and ions) which have interacted in the solar atmosphere. A major problem of solar physics is to understand the relationship between these two groups of charged particles; in particular whether they are accelerated by the same mechanism. The paper reviews the physics of gamma-rays and neutron production in the solar atmosphere and the method by which properties of the primary charged particles produced in the solar flare can be deduced. Recent observations of energetic photons and neutrons in space and at the earth are used to present a current picture of the properties of impulsively flare accelerated electrons and ions. Some important properties discussed are time scale of production, composition, energy spectra, accelerator geometry. Particular attention is given to energetic particle production in the large flare on June 3, 1982.

  13. Fluid circulating pump operated by same incident solar energy which heats energy collection fluid

    Science.gov (United States)

    Collins, E. R.

    1980-01-01

    The application of using a spacecraft solar powered pump terrestrially to reduce or eliminate the need for fossil fuel generated electricity for domestic solar hot water systems was investigated. A breadboard prototype model was constructed utilizing bimetals to convert thermal energy into mechanical motion by means of a toggle operated shutter mechanism. Although it did not meet expected thermal efficiency, the prototype model was sufficient to demonstrate the mechanical concept.

  14. Energy characteristics of finest coal particles surfaces versus their upgrading using flotation

    Energy Technology Data Exchange (ETDEWEB)

    Jerzy Sablik

    2007-07-01

    The paper presents selected results of investigations on energy properties of the fine coal particles, and methodological grounds for conducting such investigations. Using the discussed relationships, values of contact angle of coal particles with various degree of coalification in the range defined by the energy nonhomogeneity of the surfaces were computed. There have been determined the values of the contact angles of coal particles with hydrophobic and hydrophilic surfaces after coating with nonpolar and polar reagents. The energy state of the surfaces of coal particles in the feeds and products of industrial flotation were determined, which enabled to evaluate this process. 22 refs., 6 figs., 4 tabs.

  15. Particles colliders at the Large High Energy Laboratories

    International Nuclear Information System (INIS)

    Aguilar, M.

    1996-01-01

    In this work we present an elementary introduction to particle accelerators, a basic guide of existing colliders and a description of the large european laboratories devoted to Elementary Particle Physics. This work is a large, corrected and updated version of an article published in: Ciencia-Tecnologia-Medio Ambiente Annual report 1996 Edition el Pais (Author)

  16. Inelastic two composite particle systems scattering at high energy

    International Nuclear Information System (INIS)

    Zhang Yushun.

    1986-11-01

    In this paper, by using the collective coordinate of Bohr and phenomenological deformed optical potentials, the scattering amplitudes of two composite particle systems can be obtained and the collective excitation for two composite particle systems in the scattering process is discussed. (author). 10 refs, 6 figs, 2 tabs

  17. Review of lattice results concerning low-energy particle physics

    Energy Technology Data Exchange (ETDEWEB)

    Aoki, S. [Kyoto Univ. (Japan). Yukawa Inst. for Theoretical Physics; Aoki, Y. [Nagoya Univ. (Japan). Kobayashi-Maskawa Inst. for the Origin of Particles and the Universe; Brookhaven National Laboratory, Upton, NY (United States). RIKEN BNL Research Center; Becirevic, D. [Univ. Paris-Saclay, Orsay (France). CNRS; Collaboration: FLAG Working Group; and others

    2016-07-15

    We review lattice results related to pion, kaon, D- and B-meson physics with the aim of making them easily accessible to the particle physics community. More specifically, we report on the determination of the light-quark masses, the form factor f{sub +}(0), arising in the semileptonic K→π transition at zero momentum transfer, as well as the decay constant ratio f{sub K}/f{sub π} and its consequences for the CKM matrix elements V{sub us} and V{sub ud}. Furthermore, we describe the results obtained on the lattice for some of the low-energy constants of SU(2){sub L} x SU(2){sub R} and SU(3){sub L} x SU(3){sub R} Chiral Perturbation Theory. We review the determination of the B{sub K} parameter of neutral kaon mixing as well as the additional four B parameters that arise in theories of physics beyond the Standard Model. The latter quantities are an addition compared to the previous review. For the heavy-quark sector, we provide results for m{sub c} and m{sub b} (also new compared to the previous review), as well as those for D- and B-meson decay constants, form factors, and mixing parameters. These are the heavy-quark quantities most relevant for the determination of CKM matrix elements and the global CKM unitarity-triangle fit. Finally, we review the status of lattice determinations of the strong coupling constant α{sub s}.

  18. Review of lattice results concerning low-energy particle physics

    Energy Technology Data Exchange (ETDEWEB)

    Aoki, S. [Kyoto University, Center for Gravitational Physics, Yukawa Institute for Theoretical Physics, Kyoto (Japan); Aoki, Y. [Nagoya University, Kobayashi-Maskawa Institute for the Origin of Particles and the Universe (KMI), Nagoya (Japan); Brookhaven National Laboratory, RIKEN BNL Research Center, Upton, NY (United States); High Energy Accelerator Research Organization (KEK), Tsukuba (Japan); Becirevic, D. [Universite Paris-Sud, Universite Paris-Saclay, Laboratoire de Physique Theorique (UMR8627), CNRS, Orsay (France); Bernard, C. [Washington University, Department of Physics, Saint Louis, MO (United States); Blum, T. [Brookhaven National Laboratory, RIKEN BNL Research Center, Upton, NY (United States); University of Connecticut, Physics Department, Storrs, CT (United States); Colangelo, G.; Leutwyler, H.; Wenger, U. [Universitaet Bern, Albert Einstein Center for Fundamental Physics, Institut fuer Theoretische Physik, Bern (Switzerland); Della Morte, M. [University of Southern Denmark, CP3-Origins and Danish IAS, Odense M (Denmark); IFIC (CSIC), Paterna (Spain); Dimopoulos, P. [Centro Fermi-Museo Storico della Fisica e Centro Studi e Ricerche Enrico Fermi Compendio del Viminale, Rome (Italy); Universita di Roma Tor Vergata, c/o Dipartimento di Fisica, Rome (Italy); Duerr, S. [University of Wuppertal, Wuppertal (Germany); Juelich Supercomputing Center, Forschungszentrum Juelich, Juelich (Germany); Fukaya, H.; Onogi, T. [Osaka University, Department of Physics, Toyonaka, Osaka (Japan); Golterman, M. [San Francisco State University, Department of Physics and Astronomy, San Francisco, CA (United States); Gottlieb, Steven; Lunghi, E. [Indiana University, Department of Physics, Bloomington, IN (United States); Hashimoto, S.; Kaneko, T. [High Energy Accelerator Research Organization (KEK), Tsukuba (Japan); The Graduate University for Advanced Studies (Sokendai), School of High Energy Accelerator Science, Tsukuba (Japan); Heller, U.M. [American Physical Society (APS), Ridge, NY (United States); Horsley, R. [University of Edinburgh, Higgs Centre for Theoretical Physics, School of Physics and Astronomy, Edinburgh (United Kingdom); Juettner, A.; Sachrajda, C.T. [University of Southampton, School of Physics and Astronomy, Southampton (United Kingdom); Lellouch, L. [CNRS, Aix-Marseille Universite, Universite de Toulon, Centre de Physique Theorique, UMR 7332, Marseille (France); Lin, C.J.D. [CNRS, Aix-Marseille Universite, Universite de Toulon, Centre de Physique Theorique, UMR 7332, Marseille (France); National Chiao-Tung University, Institute of Physics, Hsinchu (China); Lubicz, V. [Universita Roma Tre, Dipartimento di Matematica e Fisica, Rome (Italy); INFN, Sezione di Roma Tre, Rome (Italy); Mawhinney, R. [Columbia University, Physics Department, New York, NY (United States); Pena, C. [Universidad Autonoma de Madrid, Departamento de Fisica Teorica, Instituto de Fisica Teorica UAM/CSIC, Madrid (Spain); Sharpe, S.R. [University of Washington, Physics Department, Seattle, WA (United States); Simula, S. [INFN, Sezione di Roma Tre, Rome (Italy); Sommer, R. [DESY, John von Neumann Institute for Computing (NIC), Zeuthen (Germany); Vladikas, A. [Universita di Roma ' ' Tor Vergata' ' , Dipartimento di Fisica, Rome (Italy); INFN, Rome (Italy); Wittig, H. [University of Mainz, PRISMA Cluster of Excellence, Institut fuer Kernphysik and Helmholtz Institute Mainz, Mainz (Germany); Collaboration: Flavour Lattice Averaging Group (FLAG)

    2017-02-15

    We review lattice results related to pion, kaon, D- and B-meson physics with the aim of making them easily accessible to the particle-physics community. More specifically, we report on the determination of the light-quark masses, the form factor f{sub +}(0), arising in the semileptonic K → π transition at zero momentum transfer, as well as the decay constant ratio f{sub K}/f{sub π} and its consequences for the CKM matrix elements V{sub us} and V{sub ud}. Furthermore, we describe the results obtained on the lattice for some of the low-energy constants of SU(2){sub L} x SU(2){sub R} and SU(3){sub L} x SU(3){sub R} Chiral Perturbation Theory. We review the determination of the B{sub K} parameter of neutral kaon mixing as well as the additional four B parameters that arise in theories of physics beyond the Standard Model. The latter quantities are an addition compared to the previous review. For the heavy-quark sector, we provide results for m{sub c} and m{sub b} (also new compared to the previous review), as well as those for D- and B-meson-decay constants, form factors, and mixing parameters. These are the heavy-quark quantities most relevant for the determination of CKM matrix elements and the global CKM unitarity-triangle fit. Finally, we review the status of lattice determinations of the strong coupling constant α{sub s}. (orig.)

  19. Heating nuclei with light ions at GeV incident energies

    International Nuclear Information System (INIS)

    Pollacco, E.C.; Brzychczyk, J.; Volant, C.; Legrain, R.; Nalpas, L.; Bracken, D.S.; Kwiatkowski, K.; Morley, K.B.; Foxford, E.R.; Viola, V.E.; Yoder, N.R.

    1996-03-01

    Hot nuclei are studied, where through an appropriate choice of incident channel and event selection, dynamical effects are attenuated and multifragmentation is limited. Three preparatory results are discussed, the 3 He(1.8 GeV) + nat Ag can be described using and intranuclear cascade, INC, model; through a suitable selection of events a limit of the excitation energy that a nucleus can absorb without breaking into large pieces is given, it is shown, that corresponding alpha decay is consistent with an, evaporative process. (K.A.)

  20. Relevance of axionlike particles for very-high-energy astrophysics

    International Nuclear Information System (INIS)

    De Angelis, Alessandro; Galanti, Giorgio; Roncadelli, Marco

    2011-01-01

    Several extensions of the standard model and, in particular, superstring theories suggest the existence of axionlike particles (ALPs), which are very light spin-zero bosons with a two-photon coupling. As a consequence, photon-ALP oscillations occur in the presence of an external magnetic field, and ALPs can lead to observable effects on the measured photon spectrum of astrophysical sources. An intriguing situation arises when blazars are observed in the very-high-energy (VHE) band--namely, above 100 GeV--as it is the case with the presently operating Imaging Atmospheric Cherenkov Telescopes H.E.S.S, Major Atmospheric Gamma Imaging Cherenkov telescope, Collaboration of Australia and Nippon for a Gamma Ray Observatory in the Outback III, and VERITAS. The extragalactic background light produced by galaxies during cosmic evolution gives rise to a source dimming which becomes important in the VHE band and increases with energy, since hard photons from a blazar scatter off soft extragalactic background light photons thereby disappearing into e + e - pairs. This dimming can be considerably reduced by photon-ALP oscillations, and since they are energy independent the resulting blazar spectra become harder than expected. We consider throughout a scenario first proposed by De Angelis, Roncadelli, and Mansutti in which the above strategy is implemented with photon-ALP oscillations triggered by large-scale magnetic fields, and we systematically investigate its implications for VHE blazars. We find that for ALPs lighter than 5·10 -10 eV the photon survival probability is larger than predicted by conventional physics above a few hundred GeV. Specifically, a boost factor of 10 can easily occur for sources at large distance and large energy, e.g. at 8 TeV for the blazar 1ES 0347-121 at redshift z=0.188. This is a clear-cut prediction which can be tested with the planned Cherenkov Telescope Array and the High Altitude Water Cherenkov Experiment (HAWC) water Cherenkov

  1. Configuration of particle drain for the high energy charged particles in the magnetic dipole field

    International Nuclear Information System (INIS)

    Amirkhanov, I.V.; Zhidkov, E.P.; Ignatov, V.V.; Il'ina, A.N.; Il'in, V.D.; Kuznetsov, S.N.; Yushkov, B.Yu.

    1987-01-01

    The boundary of particle leakage from the magnetic dipole trap depending on the value of adiabatic parameter is investigated. By trajectory computation a generalized analytical expression is determined for the shape of particle drain by x ≤ 1. It is shown that generally accepted adiabatic loss cone is a particular case of x → 0

  2. A new method to determine the energy of vanishing flow, using particle-particle azimuthal correlations

    Energy Technology Data Exchange (ETDEWEB)

    Buta, A [Caen Univ., 14 (France). Lab. de Physique Corpusculaire; [Institute of Atomic Physics, Bucharest (Romania); Angelique, J C; Bizard, G; Brou, R; Cussol, D [Caen Univ., 14 (France). Lab. de Physique Corpusculaire; Auger, G; Cabot, C [Grand Accelerateur National d` Ions Lourds (GANIL), 14 - Caen (France); Cassagnou, Y [CEA Centre d` Etudes de Saclay, 91 - Gif-sur-Yvette (France). Dept. d` Astrophysique, de la Physique des Particules, de la Physique Nucleaire et de l` Instrumentation Associee; Crema, E [Caen Univ., 14 (France). Lab. de Physique Corpusculaire; [Sao Paulo Univ., SP (Brazil). Inst. de Fisica; El Masri, Y [Louvain Univ., Louvain-la-Neuve (Belgium). Unite de Physique Nucleaire; others, and

    1996-09-01

    Measuring the in-plane flow parameter appears to be a promising method to gain information on the equation of state of nuclear matter. A new method, based on particle-particle azimuthal correlations is proposed. This method does not require the knowledge of the reaction plane. The collisions Zn+Ni and Ar+Al are presented as an example. (K.A.).

  3. Theoretical model application to the evaluation of fission neutron data up to 20 MeV incidence energy

    International Nuclear Information System (INIS)

    Ruben, A.; Maerten, H.; Seeliger, D.

    1990-01-01

    A complex statistical theory of fission neutron emission combined with a phenomenological fission model has been used to calculate fission neutron data for 238 U. Obtained neutron multiplicities and energy spectra as well as average fragment energies for incidence energies from threshold to 20 MeV (including multiple-chance fission) are compared with traditional data representations. (author). 19 refs, 6 figs

  4. Scaling of charged particle multiplicity in Pb-Pb collisions at SPS energies

    CERN Document Server

    Abreu, M C; Alexa, C; Arnaldi, R; Ataian, M R; Baglin, C; Baldit, A; Bedjidian, Marc; Beolè, S; Boldea, V; Bordalo, P; Borges, G; Bussière, A; Capelli, L; Castanier, C; Castor, J I; Chaurand, B; Chevrot, I; Cheynis, B; Chiavassa, E; Cicalò, C; Claudino, T; Comets, M P; Constans, N; Constantinescu, S; Cortese, P; De Falco, A; De Marco, N; Dellacasa, G; Devaux, A; Dita, S; Drapier, O; Ducroux, L; Espagnon, B; Fargeix, J; Force, P; Gallio, M; Gavrilov, Yu K; Gerschel, C; Giubellino, P; Golubeva, M B; Gonin, M; Grigorian, A A; Grigorian, S; Grossiord, J Y; Guber, F F; Guichard, A; Gulkanian, H R; Hakobyan, R S; Haroutunian, R; Idzik, M; Jouan, D; Karavitcheva, T L; Kluberg, L; Kurepin, A B; Le Bornec, Y; Lourenço, C; Macciotta, P; MacCormick, M; Marzari-Chiesa, A; Masera, M; Masoni, A; Monteno, M; Musso, A; Petiau, P; Piccotti, A; Pizzi, J R; Prado da Silva, W L; Prino, F; Puddu, G; Quintans, C; Ramello, L; Ramos, S; Rato-Mendes, P; Riccati, L; Romana, A; Santos, H; Saturnini, P; Scalas, E; Scomparin, E; Serci, S; Shahoyan, R; Sigaudo, F; Silva, S; Sitta, M; Sonderegger, P; Tarrago, X; Topilskaya, N S; Usai, G L; Vercellin, Ermanno; Villatte, L; Willis, N

    2002-01-01

    The charged particle multiplicity distribution $dN_{ch}/d\\eta$ has been measured by the NA50 experiment in Pb--Pb collisions at the CERN SPS. Measurements were done at incident energies of 40 and 158 GeV per nucleon over a broad impact parameter range. The multiplicity distributions are studied as a function of centrality using the number of participating nucleons ($N_{part}$), or the number of binary nucleon--nucleon collisions ($N_{coll}$). Their values at midrapidity exhibit a power law scaling behaviour given by $N_{part}^{1.00}$ and $N_{coll}^{0.75}$ at 158 GeV. Compatible results are found for the scaling behaviour at 40 GeV. The width of the $dN_{ch}/d\\eta$ distributions is larger at 158 than at 40 GeV/nucleon and decreases slightly with centrality at both energies. Our results are compared to similar studies performed by other experiments both at the CERN SPS and at RHIC.}

  5. Collisional effects on ion energy and angular distributions incident on RF-biased electrodes

    International Nuclear Information System (INIS)

    Qiu Huatan; Wang Younian; Ma Tengcai

    2002-01-01

    Taking into account elastic collisions and charge-exchange collisions between ions and neutral particles, the authors established a self-consistent model describing the dynamics of radio-frequency (RF) sheath driven by a sinusoidal current source, and also, using the Monte-Carlo Method, simulated energy and angle distributions of ions bombarding on RF-biased substrates. It has been shown from numerical results that as increasing the discharge pressure, bimodal-peaks distributions for the ion energy become gradually a single-peak distribution, and low-energy ions increase. The authors also found that the angle distribution of ions is narrow and almost do not change with increasing the discharge pressure

  6. A Correction of Random Incidence Absorption Coefficients for the Angular Distribution of Acoustic Energy under Measurement Conditions

    DEFF Research Database (Denmark)

    Jeong, Cheol-Ho

    2009-01-01

    Most acoustic measurements are based on an assumption of ideal conditions. One such ideal condition is a diffuse and reverberant field. In practice, a perfectly diffuse sound field cannot be achieved in a reverberation chamber. Uneven incident energy density under measurement conditions can cause...... discrepancies between the measured value and the theoretical random incidence absorption coefficient. Therefore the angular distribution of the incident acoustic energy onto an absorber sample should be taken into account. The angular distribution of the incident energy density was simulated using the beam...... tracing method for various room shapes and source positions. The averaged angular distribution is found to be similar to a Gaussian distribution. As a result, an angle-weighted absorption coefficient was proposed by considering the angular energy distribution to improve the agreement between...

  7. Deviation from an inverse cosine dependence of kinetic secondary electron emission for angle of incidence at keV energy

    International Nuclear Information System (INIS)

    Ohya, Kaoru; Kawata, Jun; Mori, Ichiro

    1989-01-01

    Incident angle dependence of kinetic secondary electron emission from metals resulting from incidence of keV ions is investigated by computer simulation with the TRIM Monte Carlo program of ion scattering in matter. The results show large deviations from the inverse cosine dependence, which derives from high-energy approximation, because of a series of elastic collisions of incident ions with metal atoms. In the keV energy region, the elastic collisions have two different effects on the angular dependence for relatively high-energy light ions and for low-energy heavy ions: they result in over- and under-inverse-cosine dependences, respectively. The properties are observed even with an experiment of the keV-neutral incidence on a contaminated surface. In addition, the effects of the thin oxide layer and roughness on the surface are examined with simplified models. (author)

  8. Low-energy particle production and residual nuclei production from high-energy hadron-nucleus collisions

    International Nuclear Information System (INIS)

    Alsmiller, F.S.; Alsmiller, R.G. Jr.; Hermann, O.W.

    1987-01-01

    The high-energy hadron-nucleus collision model, EVENTQ, has been modified to include a calculation of the excitation and kinetic energy of the residual compound nucleus. The specific purpose of the modification is to make it possible to use the model in the high-energy radiation transport code, HETC, which, in conjunction with MORSE, is used to transport the low energy particles. It is assumed that the nucleons in the nucleus move in a one-dimensional potential well and have the momentum distribution of a degenerate Fermi gas. The low energy particles produced by the deexcitation of the residual compound nucleus, and the final residual nucleus, are determined from an evaporation model. Comparisons of multiplicities and residual nuclei distributions with experimental data are given. The ''grey'' particles, i.e., charged particles with 0.25 < β < 0.7, are in good agreement with experimental data but the residual nuclei distributions are not. 12 refs., 3 figs

  9. A novel transition radiation detector utilizing superconducting microspheres for measuring the energy of relativistic high-energy charged particles

    International Nuclear Information System (INIS)

    Yuan, Luke C.L.; Chen, C.P.; Huang, C.Y.; Lee, S.C.; Waysand, G.; Perrier, P.; Limagne, D.; Jeudy, V.; Girard, T.

    2000-01-01

    A novel transition radiation detector (TRD) utilizing superheated superconducting microspheres of tin of 22-26, 27-32 and 32-38 μm in diameter, respectively, has been constructed which is capable of measuring accurately the energy of relativistic high-energy charged particles. The test has been conducted in a high-energy electron beam facility at the CERN PS in the energy range of 1-10 GeV showing an energy dependence of the TR X-ray photon produced and hence the value γ=E/mc 2 of the charged particle

  10. Semiempirical formulas for single-particle energies of neutrons and protons

    International Nuclear Information System (INIS)

    Lodhi, M.A.K.; Waak, B.T.

    1978-01-01

    The stepwise multiple linear regression technique has been used to analyze the single-particle energies of neutrons and protons in nuclei along the line of beta stability. Their regular and systematic trends lead to semiempirical model-independent formulas for single-particle energies of neutrons and protons in the bound nuclei as functions of nuclear parameters A and Z for given states specified by nl/sub j/. These formulas are almost as convenient as the harmonic oscillator energy formulas to use. The single-particle energies computed from these formulas have been compared with the experimental data and are found in reasonable agreement

  11. PREFACE: The EPS High Energy Particle Physics Conference

    Science.gov (United States)

    Barlow, Roger

    2008-03-01

    HEPP2007, the EPS High Energy Particle Physics Conference, was held in Manchester from July 19-26 2007. It brought together 580 delegates across the whole subject: from string theorists to detector technologists, from young postgraduate students to senior professors. Geographically they came from the UK, from the rest of Europe, from North America, and from the rest of the world. It covered the whole spectrum of the subject, not only accelerator-based experiments but also its astrophysical and cosmological aspects. The parallel and plenary talks can be found in these proceedings. A key feature of the conference, as always, was the award of the prizes: this year the EPS prize was awarded to Makoto Kobayashi and Toshihide Maskawa for their explanation of CP violation with a 6 quark model—Kobayashi came to accept it in person. The Gribov medal went to Niklas Beisert, the outreach prize to Richard Jacobsson and Charles Timmermans and the Young Physicist prizer to I Furic, G Gomez-Ceballos and S Menzemer. Parallel sessions were held in Manchester University, and plenary talks were held in the Bridgewater Hall in Manchester Town centre, a magnificent modern venue whose positive and co-operative staff enabled the conference to make the most of the impressive surroundings. We were able to put the hall to its proper purpose one evening with a concert by the Fairey Band—one of the distinctive brass bands who form part of the rich musical tradition of the North of England, and came as something new and different to many of the delegates. The conference ran smoothly and successfully, thanks largely to hard work by the local organising committee who devoted a lot of time to planning, producing ideas, and anticipating potential problems. Many of them were not from Manchester itself but from other universities and laboratories in the North of England, so their dedication was especially appreciated. The EPS committee also played a major part, by the selection of plenary

  12. High energy particle detectors utilizing cryogenic charge storage

    Energy Technology Data Exchange (ETDEWEB)

    Coon, D; Engels, E Jr; Plants, D; Shepard, P F; Yang, Y [Pittsburgh Univ., PA (USA); Sopira, M; Papania, R [Westinghouse Research and Development Labs., Monroeville, PA (USA)

    1984-09-15

    The mechanism of cryogenic charge storage as a method of particle detection is reviewed. A description of a simple multielement strip detector operated in this mode is given, and partial results on its operating characteristics presented.

  13. Shutter designed to block high-energy particle beams

    International Nuclear Information System (INIS)

    Donnadille, B.

    1976-01-01

    A description is given of a shutter designed for temporarily closing off an opening formed in the wall of an irradiation room for the passage of a particle beam. A cylindrical metal block can rotate about its axis and occupy two stable positions which are 180 0 from one another. A cylindrical cage closed at its two ends by two circular plates is equipped respectively with eccentric holes for the passage of the particle beam. The block is provided with a longitudinal passage through which there can pass the particle beam and a blind hole or ''pit'' disposed symmetrically to the longitudinal passage and which can block the particle beam according to the positioning of the block by respect with the eccentric holes

  14. Prompt γ energy spectrum by associated particle technique

    International Nuclear Information System (INIS)

    An Li; He Tie; Guo Haiping; Yang Jian; Zheng Pu; Wang Xinhua; Chen Yuan; Mou Yunfeng; Zhu Chuanxin; Yang Xiaofei

    2010-01-01

    The basic principle of associated alpha particle technique and the measurement system were introduced. The characteristic prompt gamma-rays coming from water, graphite, liquid nitrogen, ammonium nitrate, melamine and simulated samples induced by D-T neutron from generator were gained by single alpha particle detector and gamma-ray detector. The complex gamma-ray spectra were deconvolved. The element ratio between the experiment and chemic molecular formula is agreement in 10%. (authors)

  15. Analysis of unstable secondary particles produced in jet of 30 TeV energy sum

    International Nuclear Information System (INIS)

    Ogata, Takeshi

    1978-01-01

    High energy jet shower with energy sum of about 30 TeV has been obtained in the airplane-bone emulsion chamber. The size of the emulsion chamber was 20 cm x 25 cm x 12 cm. The airplane altitude was 260 g/cm 2 , and the exposure time was 600 hours. In this experiment, two jet events were found, and one of two events, KG-7, was the largest obtained so far. Three secondary charged particles produced by high energy interaction were analysed in detail. The analysis indicated that three charged particles seemed to be created by the decay of an unstable secondary particle. The lifetime of the unstable particle was estimated to be 10 -3 - 10 -14 sec, and this particle seems to be a charm particle. (Yoshimori, M.)

  16. Effect of heavy particles in low-energy light-particle processes

    International Nuclear Information System (INIS)

    Chan, L.H.; Hagiwara, T.; Ovrut, B.

    1979-01-01

    The ''decoupling theorem'' of Appelquist and Carazzone is found not always to be applicable to light-scalar-particle processes in spontaneously broken theories. If the Higgs scalar is considered to be light, then Higgs-scalar processes see the effect of heavy fermions and heavy vector gauge bosons at the one-loop level. If there is more than one scalar multiplet in a spontaneously broken gauge theory, the effect of a heavy Higgs particle in light-scalar-particle processes is significant at the tree level. In the latter case, such an effect can be absorbed completely into an effective phi 4 coupling constant, lambda/sub eff/, of the light particle provided that lambda/sub eff/ is positive definite

  17. A proposal for both plasma ion- and electron-temperature diagnostics under simultaneous incidence of particles and x-rays into a semiconductor on the basis of a proposed model for a semiconductor detector response

    International Nuclear Information System (INIS)

    Numakura, T; Cho, T; Kohagura, J; Hirata, M; Minami, R; Yoshida, M; Nakashima, Y; Tamano, T; Yatsu, K; Miyoshi, S

    2003-01-01

    A method is proposed for obtaining radial profiles of plasma temperatures of both plasma ion (T i ) and electron (T e ) simultaneously by the use of a semiconductor detector array. The method is based on our developed particle-response model for a semiconductor detector; in particular, the response theory is constructed for giving the applicability in particle energies ranging down to a kiloelectronvolt. Calculated results from our model are in fairly good agreement with experimental data on the detector response of incident particle beams with energies in the range 100 eV to a few kiloelectronvolts. On the basis of the verification of the proposed model, an idea of the use of a developed semiconductor detector array covered with 'reliably unbreakable' ultrathin SiO 2 'dead-layer filters' having various nanometre-order thicknesses is applied for simultaneous T i and T e analyses by using charge-exchange neutral particles and x-rays from plasmas. Radial profiles of T i and T e are obtained in a single plasma discharge alone, and the data reliability is independently cross-checked by a radial scan of a conventional charge-exchange neutral-particle analyser system as well as a 50-channel microchannel plate x-ray diagnostics system in the GAMMA 10 tandem mirror

  18. Unified semimicroscopic approach scattering of low energy protons and alpha-particles by nuclei

    International Nuclear Information System (INIS)

    Dao Tien Khoa; Kukhtina, I.N.; Knyaz'kov, O.M.; Feofilov, G.A.

    1988-01-01

    The unified approach has been developed to the description of the interaction of low energy nucleons and α-particles with nuclei. The analysis of elastic and inelastic scattering of 25.05 MeV protons and 104 MeV α-particles from 90 Zr is made. The differences in deformations of neutron and proton density distributions for 90 Zr nucleus are extracted. The energy dependence of the obtained α-particle - nucleus semimicroscopic potential is investigated, including the energy dependence for the geometry of the potential. The feaures of angular distributions of elastic α-particle scattering and the role of nucleon-nucleon correlations are analysed as a function of α-particle energy

  19. Effects of chiral three-nucleon forces on 4He-nucleus scattering in a wide range of incident energies

    Science.gov (United States)

    Toyokawa, Masakazu; Yahiro, Masanobu; Matsumoto, Takuma; Kohno, Michio

    2018-02-01

    An important current subject is to clarify the properties of chiral three-nucleon forces (3NFs) not only in nuclear matter but also in scattering between finite-size nuclei. Particularly for elastic scattering, this study has just started and the properties are not understood for a wide range of incident energies (E_in). We investigate basic properties of chiral 3NFs in nuclear matter with positive energies by using the Brueckner-Hartree-Fock method with chiral two-nucleon forces at N3LO and 3NFs at NNLO, and analyze the effects of chiral 3NFs on 4He elastic scattering from targets ^{208}Pb, ^{58}Ni, and ^{40}Ca over a wide range of 30 ≲ E_in/A_P ≲ 200 MeV by using the g-matrix folding model, where A_P is the mass number of the projectile. In symmetric nuclear matter with positive energies, chiral 3NFs make the single-particle potential less attractive and more absorptive. The effects mainly come from the Fujita-Miyazawa 2π-exchange 3NF and become slightly larger as E_in increases. These effects persist in the optical potentials of 4He scattering. As for the differential cross sections of 4He scattering, chiral-3NF effects are large for E_in/A_P ≳ 60 MeV and improve the agreement of the theoretical results with the measured ones. Particularly for E_in/A_P ≳ 100 MeV, the folding model reproduces measured differential cross sections pretty well. Cutoff (Λ) dependence is investigated for both nuclear matter and 4He scattering by considering two cases of Λ=450 and 550 MeV. The uncertainty coming from the dependence is smaller than chiral-3NF effects even at E_in/A_P=175 MeV.

  20. Determination of the area density and composition of alloy film using dual alpha particle energy loss

    Energy Technology Data Exchange (ETDEWEB)

    Ma, Xiaojun, E-mail: maxj802@163.com [Institute of Modern Physics, Fudan University, Shanghai 200433 (China); Research Center of Laser Fusion, China Academy of Engineering Physics, Mianyang 621900 (China); Li, Bo; Gao, Dangzhong [Research Center of Laser Fusion, China Academy of Engineering Physics, Mianyang 621900 (China); Xu, Jiayun [College of Physical Science and Technology, Sichuan University, Chengdu 610064 (China); Tang, Yongjian [Institute of Modern Physics, Fudan University, Shanghai 200433 (China); Research Center of Laser Fusion, China Academy of Engineering Physics, Mianyang 621900 (China)

    2017-02-01

    A novel method based on dual α-particles energy loss (DAEL) is proposed for measuring the area density and composition of binary alloy films. In order to obtain a dual-energy α-particles source, an ingenious design that utilizes the transmitted α-particles traveling the thin film as a new α-particles source is presented. Using the DAEL technique, the area density and composition of Au/Cu film are determined accurately with an uncertainty of better than 10%. Finally, some measures for improving the combined uncertainty are discussed.

  1. Energy distribution of projectile fragment particles in heavy ion therapeutic beam

    Energy Technology Data Exchange (ETDEWEB)

    Matsufuji, Naruhiro; Tomura, Hiromi; Futami, Yasuyuki [National Inst. of Radiological Sciences, Chiba (Japan)] [and others

    1998-03-01

    Production of fragment particles in a patient`s body is one of important problems for heavy charged particle therapy. It is required to know the yield and the energy spectrum for each fragment element - so called `beam quality` to understand the effect of therapeutic beam precisely. In this study, fragment particles produced by practical therapeutic beam of HIMAC were investigated with using tissue-equivalent material and a detector complex. From the results, fragment particles were well identified by difference of their atomic numbers and the beam quality was derived. Responses of the detectors in this energy region were also researched. (author)

  2. Dietary Energy Density and Postmenopausal Breast Cancer Incidence in the Cancer Prevention Study II Nutrition Cohort.

    Science.gov (United States)

    Hartman, Terryl J; Gapstur, Susan M; Gaudet, Mia M; Shah, Roma; Flanders, W Dana; Wang, Ying; McCullough, Marjorie L

    2016-10-01

    Dietary energy density (ED) is a measure of diet quality that estimates the amount of energy per unit of food (kilocalories per gram) consumed. Low-ED diets are generally high in fiber and fruits and vegetables and low in fat. Dietary ED has been positively associated with body mass index (BMI) and other risk factors for postmenopausal breast cancer. We evaluated the associations of total dietary ED and energy-dense (high-ED) foods with postmenopausal breast cancer incidence. Analyses included 56,795 postmenopausal women from the Cancer Prevention Study II Nutrition Cohort with no previous history of breast or other cancers and who provided information on diet, lifestyle, and medical history in 1999. Multivariable-adjusted breast cancer incidence rate ratios (RRs and 95% CIs) were estimated for quintiles of total dietary ED and for the consumption of high-ED foods in Cox proportional hazards regression models. During a median follow-up of 11.7 y, 2509 invasive breast cancer cases were identified, including 1857 estrogen receptor-positive and 277 estrogen receptor-negative tumors. Median dietary ED was 1.5 kcal/g (IQR: 1.3-1.7 kcal/g). After adjusting for age, race, education, reproductive characteristics, and family history, high compared with low dietary ED was associated with a statistically significantly higher risk of breast cancer (RR for fifth quintile compared with first quintile: 1.20; 95% CI: 1.05, 1.36; P-trend = 0.03). The association between the amount of high-ED foods consumed and breast cancer risk was not statistically significant. We observed no differences by estrogen receptor status or effect modification by BMI, age, or physical activity. These results suggest a modest positive association between total dietary ED and risk of postmenopausal breast cancer. © 2016 American Society for Nutrition.

  3. Theoretical Evaluation of the Escape Rate of Charged Particles Trapped in a Potential Energy Well

    International Nuclear Information System (INIS)

    Chang Yongbin; Ordonez, C.A.

    2003-01-01

    In various types of charged particle sources and traps, charged particles are temporarily trapped within a potential energy well. In the work reported, a theoretical evaluation of the escape rate of trapped charged particles is carried out. As a specific example, the loss rate is evaluated for trapped plasma particles that are undergoing both collisions among themselves and collisions with particles of a different plasma species having a different temperature. Conditions are considered in which both species are confined within a nested Penning trap

  4. Two-particle separation energy trends in the superdeformed well.

    Science.gov (United States)

    Wilson, A N; Korichi, A; Siem, S; Astier, A; Bazzacco, D; Bednarczyk, P; Bergström, M H; Chmel, S; Cullen, D M; Davidson, P M; Görgen, A; Hannachi, F; Hübel, H; Kintz, N; Lauritsen, T; Lopez-Martens, A; Lunardi, S; Naguleswaran, S; Nyakó, B M; Rejmund, M; Schönwasser, G; Schück, C; Sharpey-Schafer, J F; Timar, J; Wadsworth, R; Libert, J

    2010-04-23

    A measurement of the energy and spin of superdeformed states in 190Hg, obtained through the observation of transitions directly linking superdeformed and normal states, expands the number of isotopes in which binding energies at superdeformation are known. Comparison with neighboring nuclei shows that two-proton separation energies are higher in the superdeformed state than in the normal state, despite the lower Coulomb barrier and lower total binding energy. This unexpected result provides a critical test for nuclear models.

  5. Two-particle separation energy trends in the superdeformed well.

    Energy Technology Data Exchange (ETDEWEB)

    Wilson, A. N.; Korichi, A.; Siem, S.; Astier, A.; Bazzacco, D.; Lauristen, T.; Physics; Australian National Univ.; CSNSM-IN2P3-CNRS; Univ. of Oslo; IPN Lyon; INFN

    2010-04-23

    A measurement of the energy and spin of superdeformed states in {sup 190}Hg, obtained through the observation of transitions directly linking superdeformed and normal states, expands the number of isotopes in which binding energies at superdeformation are known. Comparison with neighboring nuclei shows that two-proton separation energies are higher in the superdeformed state than in the normal state, despite the lower Coulomb barrier and lower total binding energy. This unexpected result provides a critical test for nuclear models.

  6. Particle production in high energy nucleus-nucleus collisions

    International Nuclear Information System (INIS)

    Stock, R.

    1985-05-01

    Recent data on the production of pions and strange particles at the Bevalac and Synchrophasotron accelerators are reviewed, covering pion spectra and multiplicity distributions, Λ, K + and K - yields and spectra, and Λ polarization. Emphasis is placed on recent progress in determining the equation of state of compressed fireball nuclear matter from the observed pion yield in central collisions. Further, the information derived from apparent spectral temperatures is critically examined, along with a discussion of thermal and chemical equilibrium attainment in the reactions, as revealed by particle spectra and yields. (orig.)

  7. Signatures of energy flux in particle production: a black hole birth cry and death gasp

    Energy Technology Data Exchange (ETDEWEB)

    Good, Michael R.R. [Department of Physics, Nazarbayev University,53 Kabanbay Batyr Ave., Astana, Republic of (Kazakhstan); Ong, Yen Chin [Nordic Institute for Theoretical Physics, KTH Royal Institute of Technology Stockholm University,Roslagstullsbacken 23, SE-106 91 Stockholm (Sweden)

    2015-07-27

    It is recently argued that if the Hawking radiation process is unitary, then a black hole’s mass cannot be monotonically decreasing. We examine the time dependent particle count and negative energy flux in the non-trivial conformal vacuum via the moving mirror approach. A new, exactly unitary solution is presented which emits a characteristic above-thermal positive energy burst, a thermal plateau, and negative energy flux. It is found that the characteristic positive energy flare and thermal plateau is observed in the particle outflow. However, the results of time dependent particle production show no overt indication of negative energy flux. Therefore, a black hole’s birth cry is detectable by asymptotic observers via particle count, whereas its death gasp is not.

  8. Some characteristics of the CR-39 solid state nuclear-track detector for protons and low energy alpha particles

    International Nuclear Information System (INIS)

    Fonseca, E.S. da.

    1983-01-01

    Experimental results related to certain registration properties of the CR-39 solid state nuclear-track detector for charged particles are presented and discussed. The determination of the CR-39 chemical etching in NaOH and KOH solutions, comprising concentration (2-10N) and temperature effects (50-90 0 C), showed the existence of an inverse proportion between the induction time and the temperature as well as the normal concentration of the solutions. The critical energy and the critical energy-loss rate of CR-39 track detectors for registration of protons were experimentally determined. A number of samples was exposed to 24MeV proton beams in the IEN-CNEN Cyclotron (CV-28), using a scattering chamber with a tantalum thin target and aluminium absorbers in contact with the samples in order to provide the required fluctuation in the scattered beam energy. From the mean track-diameter plotted against incident proton energy for 16h and 24h chemical etching (6.25 NaOH, 70 0 C), and considering 1.5 μm as the minimum observable track-diameter, the values (21.0 + - 1.5) MeV and (22.5 + - 1.5) MeV were deduced, respectively, for the critical energy. From the calculated energy-loss rate versus energy curve, the critical energy-loss rate was evaluated as 24 + - 2 MeV.cm 2 /g. Finally, the CR-39 response for low energy alpha particles (E [pt

  9. Hard scattering contribution to particle production in high energy heavy-ion collisions

    International Nuclear Information System (INIS)

    Pareek, Pooja; Mishra, Aditya Nath; Sahoo, Pragati; Sahoo, Raghunath

    2014-01-01

    Global observables like the multiplicity of produced charged particles and transverse energy, are the key observables used to characterize the properties of the matter created in heavy-ion collisions. In order to study the dependence of the charged particle density on colliding system, center of mass energy and collision centrality, there have been measurements starting few GeV to TeV energies at LHC. There is a need to understand the particle production contribution coming from the QCD hard processes, which scale with number of binary nucleon-nucleon collisions, N coll and soft processes scaling with number of participant nucleons, N part

  10. Constraining sources of ultrahigh energy cosmic rays and shear acceleration mechanism of particles in relativistic jets

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Ruoyu

    2015-06-10

    Ultrahigh energy cosmic rays are extreme energetic particles from outer space. They have aroused great interest among scientists for more than fifty years. However, due to the rarity of the events and complexity of the process of their propagation to Earth, they are still one of the biggest puzzles in modern high energy astrophysics. This dissertation is dedicated to study the origin of ultrahigh energy cosmic rays from various aspects. Firstly, we discuss a possible link between recently discovered sub-PeV/PeV neutrinos and ultrahigh energy cosmic rays. If these two kinds of particles share the same origin, the observation of neutrinos may provide additional and non-trivial constraints on the sources of ultrahigh energy cosmic rays. Secondly, we jointly employ the chemical composition measurement and the arrival directions of ultrahigh energy cosmic rays, and find a robust upper limit for distances of sources of ultrahigh energy cosmic rays above ∝55 EeV, as well as a lower limit for their metallicities. Finally, we study the shear acceleration mechanism in relativistic jets, which is a more efficient mechanism for the acceleration of higher energy particle. We compute the acceleration efficiency and the time-dependent particle energy spectrum, and explore the feature of synchrotron radiation of the accelerated particles. The possible realizations of this mechanism for acceleration of ultrahigh energy cosmic rays in different astrophysical environments is also discussed.

  11. Feasibility Study for High Power RF – Energy Recovery in Particle Accelerators

    CERN Document Server

    Betz, Michael

    2010-01-01

    When dealing with particle accelerators, especially in systems with travelling wave structures and low beam loading, a substantial amount of RF power is dissipated in 50Ω termination loads. For the Super Proton Synchrotron (SPS) at Cern this is 69 % of the incident RF power or about 1 MW. Different ideas, making use of that otherwise dissipated power, are presented and their feasibility is reviewed. The most feasible one, utilizing an array of semiconductor based RF/DC modules, is used to create a design concept for energy recovery in the SPS. The modules are required to operate at high power, high efficiency and with low harmonic radiation. Besides the actual RF rectifier, they contain additional components to ensure a graceful degradation of the overall system. Different rectifier architectures and semiconductor devices are compared and the most suitable ones are chosen. Two prototype devices were built and operated with up to 400 W of pulsed RF power. Broadband measurements – capturing all harmonics up ...

  12. Modeling the radar scatter off of high-energy neutrino-induced particle cascades in ice

    NARCIS (Netherlands)

    de Vries, Krijn D.; van Eijndhoven, Nick; O'Murchadha, Aongus; Toscano, Simona; Scholten, Olaf

    2017-01-01

    We discuss the radar detection method as a probe for high-energy neutrino induced particle cascades in ice. In a previous work we showed that the radar detection techniqe is a promising method to probe the high-energy cosmic neutrino flux above PeV energies. This was done by considering a simplified

  13. Predictable Particle Engineering: Programming the Energy Level, Carrier Generation, and Conductivity of Core-Shell Particles.

    Science.gov (United States)

    Yuan, Conghui; Wu, Tong; Mao, Jie; Chen, Ting; Li, Yuntong; Li, Min; Xu, Yiting; Zeng, Birong; Luo, Weiang; Yu, Lingke; Zheng, Gaofeng; Dai, Lizong

    2018-06-20

    Core-shell structures are of particular interest in the development of advanced composite materials as they can efficiently bring different components together at nanoscale. The advantage of this structure greatly relies on the crucial design of both core and shell, thus achieving an intercomponent synergistic effect. In this report, we show that decorating semiconductor nanocrystals with a boronate polymer shell can easily achieve programmable core-shell interactions. Taking ZnO and anatase TiO 2 nanocrystals as inner core examples, the effective core-shell interactions can narrow the band gap of semiconductor nanocrystals, change the HOMO and LUMO levels of boronate polymer shell, and significantly improve the carrier density of core-shell particles. The hole mobility of core-shell particles can be improved by almost 9 orders of magnitude in comparison with net boronate polymer, while the conductivity of core-shell particles is at most 30-fold of nanocrystals. The particle engineering strategy is based on two driving forces: catechol-surface binding and B-N dative bonding and having a high ability to control and predict the shell thickness. Also, this approach is applicable to various inorganic nanoparticles with different components, sizes, and shapes.

  14. High energy particles from {gamma}-ray bursts

    Energy Technology Data Exchange (ETDEWEB)

    Waxman, E [Weizmann Institute of Science, Rehovot (Israel)

    2001-11-15

    A review is presented of the fireball model of {gamma}-ray bursts (GRBs), and of the production in GRB fireballs of high energy protons and neutrinos. Constraints imposed on the model by recent afterglow observations, which support the association of GRB and ultra-high energy cosmic-ray (UHECR) sources, are discussed. Predictions of the GRB model for UHECR production, which can be tested with planned large area UHECR detectors and with planned high energy neutrino telescopes, are reviewed. (author)

  15. On the validity of classical description of scattering of atomic particles at mean energies

    International Nuclear Information System (INIS)

    Pustovit, A.N.

    2004-01-01

    The conditions of applicability of the classical theory of atomic particle scattering to the small angle and quasi-small angle approximations in calculations of mean-energy particle deflection angles using power interaction potential are analyzed. The applicability range is shown to be much widened for the quasi-small angle approximation, extending to the ranges of quantum theory applicability [ru

  16. Aerosol nucleation induced by a high energy particle beam

    DEFF Research Database (Denmark)

    Enghoff, Martin Andreas Bødker; Pedersen, Jens Olaf Pepke; Uggerhøj, Ulrik I.

    2011-01-01

    We have studied sulfuric acid aerosol nucleation in an atmospheric pressure reaction chamber using a 580 MeV electron beam to ionize the volume of the reaction chamber. We find a clear contribution from ion-induced nucleation and consider this to be the first unambiguous observation of the ion......-effect on aerosol nucleation using a particle beam under conditions that resemble the Earth's atmosphere. By comparison with ionization using a gamma source we further show that the nature of the ionizing particles is not important for the ion-induced component of the nucleation. This implies that inexpensive...... ionization sources - as opposed to expensive accelerator beams - can be used for investigations of ion-induced nucleation....

  17. The transmission of differing energy beta particles through various materials

    International Nuclear Information System (INIS)

    Quayle, D.R.

    1996-04-01

    The transmission of beta particles is frequently calculated in the same fashion as that of gamma rays, where the mass attenuation coefficient is defined by the slope of the exponential function. Numerous authors have used this approximation including Evans (1955), Loevinger (1952), and Chabot et. al. (1988). Recent work by McCarthy et. al. (1995) indicated that the exponential function seemed to fit well over a particular region of the transmission curve. Upon further investigation, the author decided to verify McCarthy's results by the use of different absorber materials and attempt to reproduce the experiments. A theoretical method will be used to estimate the transmission of the beta particles through the three absorbers, aluminum, zirconium, and iron. An alternate Monte Carlo code, the Electron Gamma Shower version 4 code (EGS4) will also be used to verify that the experiment is approximating a pencil beam of beta particles. Although these two methods offer a good cross check for the experimental data, they pose a conflict in regards to the type of beam that is to be generated. The experimental lab setup uses a collimated beam of electrons that will impinge upon the absorber, while the codes are written using a pencil beam. A minor discrepancy is expected to be observed in the experimental results and is currently under investigation by McCarthy. The results of this project supported the theory that the beta mass attenuation coefficient was accurately represented by the slope of an exponential function, but only for that particular region of the transmission curve that has a minimal absorber thickness. By fitting the data beyond 50% of the beta particle range this theory does not hold true. The theory generated by McCarthy (1995) and the EGS4 Monte Carlo code indicated that the transmission curve for a pencil beam was not accurately represented by an exponential function. The results of this experiment appeared to provide additional support to this assumption

  18. Zitterbewegung of the new positive-energy particle

    International Nuclear Information System (INIS)

    Dirac, P.A.M.

    1973-01-01

    Recent developments of the new wave equation (delta/delta x 0 + α/sub r/(delta/delta x/sub r/) + beta)g psi = 0 are discussed. One has a particle of a mass 1 with some internal motion and satisfying the usual de Broglie equation for all values of the internal variables. One finds the given equation is really a relativistic equation. (U.S.)

  19. Experimental investigations in particle physics at intermediate energies

    International Nuclear Information System (INIS)

    Auerbach, L.B.; Highland, V.L.; Martoff, C.J.; McFarlane, K.W.; Buchholz, P.; Sivertz, M.B.

    1989-01-01

    The major emphasis of this project continues to be on fundamental symmetries and parameters of the Standard Model. The primary project is BNL E791, a search for the decay K L 0 → μe, which would violate the rule of separate lepton number conservation. The technique uses a drift-chamber spectrometer, with particle identification, picking out candidate decays from 2-particle triggers by measuring the two-particle invariant mass m, and the collinearity angle Θ c . For reconstructed K L 0 → π + π - decays the rms resolution in m was ∼1.4 MeV/c 2 , and in Θ c it was ∼0.3 mrad; these values match the design specifications. All the data from the 1988 run of E971 have been analyzed for K L 0 μe, K L 0 → μe, K L 0 → μμ, and K L 0 → ee events, and the results submitted for publication. We find an upper limit from the 1988 data for the branching fraction of K L 0 → μe of 2.2 x 10 -10 and a limit of 3.1 x 10 -10 for K L 0 → ee. We also measured the branching fraction for K L 0 μμ to be (5.8 ± 0.6 ± 0.4) x 10 -9 , with a sample of 87 events. Our limits are the best reported. The limit on the decay K L 0 → μe places a lower limit on the mass of a new particle mediating such decays of 50 TeV. The other neutrino work at Los Alamos, E764, will result in a final publication. Calculations are being completed of the neutrino flux, necessary for the measurement of the ν μ 12 C inclusive cross sections. These will be the best measurements of ν-nuclear scattering

  20. Quasi-particle excitations in low energy fission

    International Nuclear Information System (INIS)

    Ashgar, M.; Djebara, M.; Bocquet, J.P.; Brissot, R.; Maurel, M.; Nifenecker, H.; Ristori, C.

    1985-05-01

    Proton odd-even effect for 229 Th(nsub(th),f) and 232 U(nsub(th),f) has been determined with a ΔE-Esub(R) gas telescope. These data indicate that the qp-particle excitation probability at the saddle point is small and most of its results, when the nucleus moves from saddle to scission and the neck ruptures into final fragments. These results are discussed in terms of the different ideas and models

  1. Choice of theoretical model for beam scattering at accelerator output foil for particle energy determination

    International Nuclear Information System (INIS)

    Balagyra, V.S.; Ryabka, P.M.

    1999-01-01

    For measuring the charged particle energy calculations of mean square angles of electron beam multiple Coulomb scattering at output combined accelerator target were undertaken according to seven theoretical models. Mollier method showed the best agreement with experiments

  2. Alpha-particle energy spectra measured at forward angles in heavy-ion-induced reactions

    International Nuclear Information System (INIS)

    Borcea, C.; Cierlic, E.; Kalpakchieva, R.; Oganessian, Yu.Ts.; Penionzhkevich, Yu.E.

    1980-01-01

    Energy spectra have been measured for α-particles emitted in the bombardment of 159 Tb, 181 Ta, 197 Au, and 232 Th nuclei by 20 Ne, 22 Ne, and 40 Ar projectiles. The reaction products emitted in the angular range (0+-2)deg relative to the beam direction were analyzed using a magnetic spectrometer and detected by means of a semiconductor ΔE-E telescope. It was found that in all cases the experimentally measured maximum α-particle energy almost amounts to the maximum possible value calculated from the reaction energy balance for a two-body exit channel. A correlation was found between the measured absolute cross section in different target-projectile combinations and the α-particle binding energy in the target nuclei. On the basis of the obtained results a conclusion has been drawn that the α-particles are emitted in the early stage of the reaction

  3. Single-particle energies and density of states in density functional theory

    Science.gov (United States)

    van Aggelen, H.; Chan, G. K.-L.

    2015-07-01

    Time-dependent density functional theory (TD-DFT) is commonly used as the foundation to obtain neutral excited states and transition weights in DFT, but does not allow direct access to density of states and single-particle energies, i.e. ionisation energies and electron affinities. Here we show that by extending TD-DFT to a superfluid formulation, which involves operators that break particle-number symmetry, we can obtain the density of states and single-particle energies from the poles of an appropriate superfluid response function. The standard Kohn- Sham eigenvalues emerge as the adiabatic limit of the superfluid response under the assumption that the exchange- correlation functional has no dependence on the superfluid density. The Kohn- Sham eigenvalues can thus be interpreted as approximations to the ionisation energies and electron affinities. Beyond this approximation, the formalism provides an incentive for creating a new class of density functionals specifically targeted at accurate single-particle eigenvalues and bandgaps.

  4. Observation of strong azimuthal asymmetry between slow and fast particles from high energy nuclear collisions

    International Nuclear Information System (INIS)

    Gustafsson, H.A.; Gutbrod, H.H.; Kolb, B.; Loehner, H.; Ludewigt, B.; Poskanzer, A.M.; Renner, T.; Riedesel, H.; Ritter, H.G.; Siemiarczuk, T.; Stepaniak, J.; Warwick, A.; Wieman, H.

    1984-10-01

    Evidence is presented for the strong azimuthal asymmetry between slow and fast fragments in nuclear collisions in the energy interval of 0.4 to 1 GeV per nucleon. The asymmetry gets stronger when incident energy and impact parameter decrease. The results on the A dependence of the azimuthal asymmetry are also presented. (orig.)

  5. The role of fluid compression in energy conversion and particle energization during magnetic reconnection

    Science.gov (United States)

    Li, X.; Guo, F.; Li, G.; Li, H.

    2016-12-01

    Theories of particle transport and acceleration have shown that fluid compression is the leading mechanism for particle acceleration and plasma energization. However, the role of compression in particle acceleration during magnetic reconnection is unclear. We use two approaches to study this issue. First, using fully kinetic simulations, we quantitatively calculate the effect of compression in energy conversion and particle energization during magnetic reconnection for a range of plasma beta and guide field. We show that compression has an important contribution for the energy conversion between the bulk kinetic energy and the internal energy when the guide field is smaller than the reconnecting component. Based on this result, we then study the large-scale reconnection acceleration by solving the Parker's transport equation in a background reconnecting flow provided by MHD simulations. Due to the compression effect, the simulations suggest fast particle acceleration to high energies in the reconnection layer. This study clarifies the nature of particle acceleration in reconnection layer, and may be important to understand particle acceleration and plasma energization during solar flares.

  6. Scanning of irradiated silicon detectors using $\\alpha$ particles and low energy protons

    CERN Document Server

    Casse, G L; Glaser, M; Kohout, Z; Konícek, J; Lemeilleur, F; Leroy, C; Linhart, V; Mares, J J; Pospísil, S; Roy, P; Sopko, B; Sinor, M; Svejda, J; Vorobel, V; Wilhelm, I

    1999-01-01

    In a spectroscopic study of non-irradiated and proton-irradiated silicon diodes, the detectors were illuminated from the front side and from the rear side by various alpha particle sources (mainly ThC') and by monoenergetic protons with energies from 1.0 to 2.5~MeV. Their response characteristics have been studied as a function of the incoming particle energy and the applied bias voltage. The charge collection efficiency was determined as a function of fluence

  7. Density and energy distribution of epithermal secondary electrons in a plasma with fast charged particles

    International Nuclear Information System (INIS)

    Jayakumar, R.; Fleischmann, H.H.

    1989-01-01

    The production of intermediate energy secondary electrons in plasmas through collisions with fast charged particles is investigated. The density and the distribution of the secondary electrons are obtained by calculating the generation, slow down and diffusion rates, using basic Rutherford collision cross sections. It is shown that the total density of secondaries is much smaller than the fast particle density and that the energy distribution has roughly a 1/√E dependence. The higher generation secondary populations are also obtained. (orig.)

  8. Response of spherical gravitational wave antenna modes to high-energy cosmic ray particles

    International Nuclear Information System (INIS)

    Jr, R M Marinho; Magalhaes, N S; Aguiar, O D; Frajuca, C

    2002-01-01

    High-energy cosmic ray particles are expected to be a significant source of noise in resonant mass gravitational wave detectors close to the quantum limit. The spherical, fourth generation antennas have been designed to attain such a limit. In this work we will show how the energy of a cosmic ray particle interacting with such an antenna is distributed over its eigenmodes. We will then make some comments on the relevant consequences of such a distribution for gravitational wave detection

  9. Frontiers of particle beam and high energy density plasma science using pulse power technology

    International Nuclear Information System (INIS)

    Masugata, Katsumi

    2011-04-01

    The papers presented at the symposium on “Frontiers of Particle Beam and High Energy Density Plasma Science using Pulse Power Technology” held in November 20-21, 2009 at National Institute for Fusion Science are collected. The papers reflect the present status and resent progress in the experiment and theoretical works on high power particle beams and high energy density plasmas produced by pulsed power technology. (author)

  10. Response of spherical gravitational wave antenna modes to high-energy cosmic ray particles

    CERN Document Server

    Marinho, R M; Aguiar, O D; Frajuca, C

    2002-01-01

    High-energy cosmic ray particles are expected to be a significant source of noise in resonant mass gravitational wave detectors close to the quantum limit. The spherical, fourth generation antennas have been designed to attain such a limit. In this work we will show how the energy of a cosmic ray particle interacting with such an antenna is distributed over its eigenmodes. We will then make some comments on the relevant consequences of such a distribution for gravitational wave detection.

  11. High-energy charged particles in space at one astronomical unit

    International Nuclear Information System (INIS)

    Feynman, J.; Gabriel, S.B.

    1996-01-01

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

  12. Simulating the energy deposits of particles in the KASCADE-grande detector stations as a preliminary step for EAS event reconstruction

    International Nuclear Information System (INIS)

    Toma, G.; Brancus, I.M.; Mitrica, B.; Sima, O.; Rebel, H.; Haungs, A.

    2005-01-01

    The study of primary cosmic rays with energies higher than 10 14 eV is done mostly by indirect observation techniques such as the study of Extensive Air Showers (EAS). In the much larger framework effort of inferring data on the mass and energy of the primaries from EAS observables, the present study aims at developing a versatile method and software tool that will be used to reconstruct lateral particle densities from the energy deposits of particles in the KASCADE-Grande detector stations. The study has been performed on simulated events, by taking into account the interaction of the EAS components with the detector array (energy deposits). The energy deposits have been simulated using the GEANT code and then the energy deposits have been parametrized for different incident energies and angles of EAS particles. Thus the results obtained for simulated events have the same level of consistency as the experimental data. This technique will allow an increased speed of lateral particle density reconstruction when studying real events detected by the KASCADE-Grande array. The particle densities in detectors have been reconstructed from the energy deposits. A correlation between lateral particle density and primary mass and primary energy (at ∼600 m from shower core) has been established. The study puts great emphasis on the quality of reconstruction and also on the speed of the technique. The data obtained from the study on simulated events creates the basis for the next stage of the study, the study of real events detected by the KASCADE-Grande array. (authors)

  13. High energy charged particle registration in CR-39 polycarbonated detector

    International Nuclear Information System (INIS)

    Abdel-Wahab, M.S.; El Enany, N.; El Fiki, S.; Eissa, H.M.; El-Adl, E.H.; El-Feky, M.A.

    1991-01-01

    Track etch rate characteristics of CR-39 plastic detector exposed to 28 Si ions of 670 MeV energy have been investigated. Experimental results were obtained in terms of frequency distribution of the track diameter, track density and bulk etching rate. A dependence of the mean track diameter on energy was found. The application of the radiation effect of heavy ions on CR-39 in the field of radiation detection and dosimetry are discussed. Results indicated that it is possible to produce etchable tracks of 28 Si in this energy range in CR-39. We also report the etching characteristics of these tracks in the CR-39 detector. (orig.) [de

  14. Self-energies and the interactions of particles with surfaces

    International Nuclear Information System (INIS)

    Manson, J.R.; Ritchie, R.H.; Echenique, P.M.; Gras-Marti, A.

    1987-01-01

    We have in this paper reviewed the method of treating many-body problems by means of an effective interaction self-energy. We have developed an alternatvie approach to the self-energy which is simpler and more straight-forward than standard methods, and we have illustrated its use with two examples of a charge interacting with a metal surface. In each case the self-energy produces the classical image potential together with corrections due to quantum mechanical effects. This method has also been successfully applied to the problem of an atom interacting with a surface. Corrections to the Van der Waals dispersion force are obtained, and via the non-conservative imaginary parts to /summation//sub i/(z) we discuss transition rates and energy exchange. 14 refs., 1 fig

  15. Resolving Rapid Variation in Energy for Particle Transport

    Energy Technology Data Exchange (ETDEWEB)

    Haut, Terry Scot [Los Alamos National Lab. (LANL), Los Alamos, NM (United States). Computer, Computational, and Statistical Sciences Division; Ahrens, Cory Douglas [Los Alamos National Lab. (LANL), Los Alamos, NM (United States). Computer, Computational, and Statistical Sciences Division; Jonko, Alexandra [Los Alamos National Lab. (LANL), Los Alamos, NM (United States). Computer, Computational, and Statistical Sciences Division; Till, Andrew Thomas [Los Alamos National Lab. (LANL), Los Alamos, NM (United States). Computer, Computational, and Statistical Sciences Division; Lowrie, Robert Byron [Los Alamos National Lab. (LANL), Los Alamos, NM (United States). Computer, Computational, and Statistical Sciences Division

    2016-08-23

    Resolving the rapid variation in energy in neutron and thermal radiation transport is needed for the predictive simulation capability in high-energy density physics applications. Energy variation is difficult to resolve due to rapid variations in cross sections and opacities caused by quantized energy levels in the nuclei and electron clouds. In recent work, we have developed a new technique to simultaneously capture slow and rapid variations in the opacities and the solution using homogenization theory, which is similar to multiband (MB) and to the finite-element with discontiguous support (FEDS) method, but does not require closure information. We demonstrated the accuracy and efficiency of the method for a variety of problems. We are researching how to extend the method to problems with multiple materials and the same material but with different temperatures and densities. In this highlight, we briefly describe homogenization theory and some results.

  16. Contact angle and detachment energy of shape anisotropic particles at fluid-fluid interfaces.

    Science.gov (United States)

    Anjali, Thriveni G; Basavaraj, Madivala G

    2016-09-15

    The three phase contact angle of particles, a measure of its wettability, is an important factor that greatly influences their behaviour at interfaces. It is one of the principal design parameters for potential applications of particles as emulsion/foam stabilizers, functional coatings and other novel materials. In the present work, the effect of size, shape and surface chemistry of particles on their contact angle is investigated using the gel trapping technique, which facilitates the direct visualization of the equilibrium position of particles at interfaces. The contact angle of hematite particles of spherocylindrical, peanut and cuboidal shapes, hematite-silica core-shell and silica shells is reported at a single particle level. The spherocylindrical and peanut shaped particles are always positioned with their major axis parallel to the interface. However, for cuboidal particles at air-water as well as decane-water interfaces, different orientations namely - face-up, edge-up and the vertex-up - are observed. The influence of gravity on the equilibrium position of the colloidal particles at the interface is studied using the hematite-silica core-shell particles and the silica shells. The measured contact angle values are utilized in the calculations of the detachment and surface energies of the hematite particles adsorbed at the interface. Copyright © 2016 Elsevier Inc. All rights reserved.

  17. Review of lattice results concerning low energy particle physics

    DEFF Research Database (Denmark)

    Aoki, Sinya; Aoki, Yasumichi; Bernard, Claude

    2014-01-01

    We review lattice results related to pion, kaon, D- and B-meson physics with the aim of making them easily accessible to the particle physics community. More specifically, we report on the determination of the light-quark masses, the form factor f+(0), arising in semileptonic K -> pi transition...... Theory and review the determination of the BK parameter of neutral kaon mixing. The inclusion of heavy-quark quantities significantly expands the FLAG scope with respect to the previous review. Therefore, for this review, we focus on D- and B-meson decay constants, form factors, and mixing parameters...

  18. Charged particle induced energy dispersive X-ray analysis

    International Nuclear Information System (INIS)

    Johansson, S.A.E.

    1979-01-01

    This review article deals with the X-ray emission induced by heavy, charged particles and the use of this process as an analytical method (PIXE). The physical processes involved, X-ray emission and the various reactions contributing to the background, are described in some detail. The sensitivity is calculated theoretically and the results compared with practical experience. A discussion is given on how the sensitivity can be optimized. The experimental arrangements are described and the various technical problems discussed. The analytical procedure, especially the sample preparation, is described in considerable detail. A number of typical practical applications are discussed. (author)

  19. A code to determine the energy distribution, the incident energy and the flux of a beam of light ions into a stack of foils

    International Nuclear Information System (INIS)

    Sonzogni, A.A.; Romo, A.S.M.A.; Frosch, W.R.; Nassiff, S.J.

    1992-01-01

    The stacked-foil technique is one of the most used methods to obtain excitation functions of nuclear reactions using light ions as projectiles. The purpose of this program is the calculation of the energy of the beam in the stack, as well as to obtain the incident energy and the flux of the beam by using monitor excitation functions. (orig.)

  20. Modelling of prompt losses of high energy charged particles in Tokamaks

    International Nuclear Information System (INIS)

    Dillner, Oe.; Anderson, D.; Hamnen, H.; Lisak, M.

    1990-01-01

    A simple analytical expression for the total prompt loss fraction of high energy charged particles in an axisymmetric Tokamak is derived. The results are compared with predictions obtained from numerical simulations and show good agreement. An application is made to sawtooth induced changes in the losses of fusion generated high energy charged particles. Particular emphasis is given to the importance of sawtooth induced profile changes of the background ion densities and temperature as well as to redistribution of particles which have accumulated during the sawtooth rise but are being lost by redistribution at the sawtooth crash. (au)

  1. Emission of medium-heavy fragments in asymetric heavy ion collisions at intermediate and relativistic incident energies

    International Nuclear Information System (INIS)

    Milkau, T.U.E.

    1991-11-01

    For the study of the emission of medium-heavy fragments in asymmetric heavy ion collisions a series of experiments was performed and thereby following systems at intermediate and relativistic incident energies studied: 84 Kr+ 197 Au at E/A=35 MeV, 40 Ar+ 197 Au at E/A=30 MeV, respectively 220 MeV, and 12 C+ 197 Au at E/A=99 MeV, 301 MeV, 601 MeV, respectively 1105 MeV. In the experiments highly resolving detector telescopes with low thresholds were applied to the measurement of the energy and angular distributions of the medium-heavy fragments. The spectra were analyzed in the picture of longitudinally moving sources. Thereby beyond the production cross sections the angular distributions, the decreasement parameters in the high-energetic region of the energy spectra, and the position of the maxima were determined as characteristic parameters. The following picture resulted: The production cross sections for medium-heavy fragments showed a steep increasement and then a saturation, but with a strong projectile dependence. The charge distributions could be described by a power law, the parameter of which showed a universal dependence on the total incident energy. In the angular distributions the transition from an anisotropic emission at low energies to an isotropic emission from a nearly resting source at relativistic energies was distinctly to be recognized. The decreasement parameters of the energy distribution increased - for different projectiles differently strongly - logarithmically with growing incident energy. And the maxima of the energy distribution travelled with growing incident energy to smaller and smaller fragment energies. From this systematics a schematic model of the fragmentation can be obtained. (orig./HSI) [de

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

    International Nuclear Information System (INIS)

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

    2012-01-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2012-09-10

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

  4. Transverse energy and charged particle production in heavy-ion collisions: from RHIC to LHC

    International Nuclear Information System (INIS)

    Sahoo, Raghunath; Mishra, Aditya Nath

    2014-01-01

    We study the charged particle and transverse energy production mechanism from AGS, SPS, Relativistic Heavy-Ion Collider (RHIC) to Large Hadron Collider (LHC) energies in the framework of nucleon and quark participants. At RHIC and LHC energies, the number of nucleons-normalized charged particle and transverse energy density in pseudorapidity, which shows a monotonic rise with centrality, turns out to be an almost centrality independent scaling behavior when normalized to the number of participant quarks. A universal function which is a combination of logarithmic and power-law, describes well the charged particle and transverse energy production both at nucleon and quark participant level for the whole range of collision energies. Energy dependent production mechanisms are discussed both for nucleonic and partonic level. Predictions are made for the pseudorapidity densities of transverse energy, charged particle multiplicity and their ratio (the barometric observable, [dE T /dη]/[dN ch /dη] ≡ E T /N ch ) at mid-rapidity for Pb + Pb collisions at √s NN = 5.5 TeV. A comparison with models based on gluon saturation and statistical hadron gas is made for the energy dependence of E T /N ch . (author)

  5. Use of medium energy particles in radiobiology and radiotherapy

    International Nuclear Information System (INIS)

    Larsson, B.

    1984-01-01

    The radiological properties of ion beams are described and their biomedical use reviewed. The special features and potentialities of secondary radiations obtained with medium-energy accelerators for protons of electrons are mentioned, for comparison. Examples are given from work at heavy accelerators which has contributed to our basic knowledge of radiation effects on cells and tissues, or to recent advances in experimental and clinical radiology. The author tries to identify areas where important spin-off contributions from medium-energy physics to the biomedical sciences could be made, or where such contributions would have significant implications for the society. The conclusion is made that medium energy accelerators have great potential in experimental and preclinical research, particularly in neurophysiology and oncology

  6. Energy transport in a shear flow of particles in a two-dimensional dusty plasma.

    Science.gov (United States)

    Feng, Yan; Goree, J; Liu, Bin

    2012-11-01

    A shear flow of particles in a laser-driven two-dimensional (2D) dusty plasma is observed in a study of viscous heating and thermal conduction. Video imaging and particle tracking yields particle velocity data, which we convert into continuum data, presented as three spatial profiles: mean particle velocity (i.e., flow velocity), mean-square particle velocity, and mean-square fluctuations of particle velocity. These profiles and their derivatives allow a spatially resolved determination of each term in the energy and momentum continuity equations, which we use for two purposes. First, by balancing these terms so that their sum (i.e., residual) is minimized while varying viscosity η and thermal conductivity κ as free parameters, we simultaneously obtain values for η and κ in the same experiment. Second, by comparing the viscous heating and thermal conduction terms, we obtain a spatially resolved characterization of the viscous heating.

  7. Simulation of high-energy particle production through sausage and kink instabilities in pinched plasma discharges

    International Nuclear Information System (INIS)

    Haruki, Takayuki; Yousefi, Hamid Reza; Masugata, Katsumi; Sakai, Jun-Ichi; Mizuguchi, Yusuke; Makino, Nao; Ito, Hiroaki

    2006-01-01

    In an experimental plasma, high-energy particles were observed by using a plasma focus device, to obtain energies of a few hundred keV for electrons, up to MeV for ions. In order to study the mechanism of high-energy particle production in pinched plasma discharges, a numerical simulation was introduced. By use of a three-dimensional relativistic and fully electromagnetic particle-in-cell code, the dynamics of a Z-pinch plasma, thought to be unstable against sausage and kink instabilities, are investigated. In this work, the development of sausage and kink instabilities and subsequent high-energy particle production are shown. In the model used here, cylindrically distributed electrons and ions are driven by an external electric field. The driven particles spontaneously produce a current, which begins to pinch by the Lorentz force. Initially the pinched current is unstable against a sausage instability, and then becomes unstable against a kink instability. As a result high-energy particles are observed

  8. Aerosol nucleation induced by a high energy particle beam

    DEFF Research Database (Denmark)

    Enghoff, Martin Andreas Bødker; Pedersen, Jens Olaf Pepke; Uggerhøj, Ulrik I.

    The effect of ions in aerosol nucleation is a subject where much remains to be discovered. That ions can enhance nucleation has been shown by theory, observations, and experiments. However, the exact mechanism still remains to be determined. One question is if the nature of the ionization affects...... the nucleation. This is an essential question since many experiments have been performed using radioactive sources that ionize differently than the cosmic rays which are responsible for the majority of atmospheric ionization. Here we report on an experimental study of sulphuric acid aerosol nucleation under near...... atmospheric conditions using a 580 MeV electron beam to ionize the volume of the reaction chamber. We find a clear and significant contribution from ion induced nucleation and consider this to be an unambiguous observation of the ion-effect on aerosol nucleation using a particle beam under conditions not far...

  9. Review of lattice results concerning low-energy particle physics

    DEFF Research Database (Denmark)

    Aoki, Sinya; Aoki, Yasumichi; Bečirević, D.

    2017-01-01

    We review lattice results related to pion, kaon, D- and B-meson physics with the aim of making them easily accessible to the particle-physics community. More specifically, we report on the determination of the light-quark masses, the form factor f+(0) , arising in the semileptonic K→ π transition...... review the determination of the BK parameter of neutral kaon mixing as well as the additional four B parameters that arise in theories of physics beyond the Standard Model. The latter quantities are an addition compared to the previous review. For the heavy-quark sector, we provide results for mc and mb...... (also new compared to the previous review), as well as those for D- and B-meson-decay constants, form factors, and mixing parameters. These are the heavy-quark quantities most relevant for the determination of CKM matrix elements and the global CKM unitarity-triangle fit. Finally, we review the status...

  10. Development of High Energy Particle Detector for the Study of Space Radiation Storm

    Directory of Open Access Journals (Sweden)

    Gyeong-Bok Jo

    2014-09-01

    Full Text Available Next Generation Small Satellite-1 (NEXTSat-1 is scheduled to launch in 2017 and Instruments for the Study of Space Storm (ISSS is planned to be onboard the NEXTSat-1. High Energy Particle Detector (HEPD is one of the equipment comprising ISSS and the main objective of HEPD is to measure the high energy particles streaming into the Earth radiation belt during the event of a space storm, especially, electrons and protons, to obtain the flux information of those particles. For the design of HEPD, the Geometrical Factor was calculated to be 0.05 to be consistent with the targets of measurement and the structure of telescope with field of view of 33.4° was designed using this factor. In order to decide the thickness of the detector sensor and the classification of the detection channels, a simulation was performed using GEANT4. Based on the simulation results, two silicon detectors with 1 mm thickness were selected and the aluminum foil of 0.05 mm is placed right in front of the silicon detectors to shield low energy particles. The detection channels are divided into an electron channel and two proton channels based on the measured LET of the particle. If the measured LET is less than 0.8 MeV, the particle belongs to the electron channel, otherwise it belongs to proton channels. HEPD is installed in the direction of 0°,45°,90° against the along-track of a satellite to enable the efficient measurement of high energy particles. HEPD detects electrons with the energy of 0.1 MeV to several MeV and protons with the energy of more than a few MeV. Thus, the study on the dynamic mechanism of these particles in the Earth radiation belt will be performed.

  11. Directed Magnetic Particle Transport above Artificial Magnetic Domains Due to Dynamic Magnetic Potential Energy Landscape Transformation.

    Science.gov (United States)

    Holzinger, Dennis; Koch, Iris; Burgard, Stefan; Ehresmann, Arno

    2015-07-28

    An approach for a remotely controllable transport of magnetic micro- and/or nanoparticles above a topographically flat exchange-bias (EB) thin film system, magnetically patterned into parallel stripe domains, is presented where the particle manipulation is achieved by sub-mT external magnetic field pulses. Superparamagnetic core-shell particles are moved stepwise by the dynamic transformation of the particles' magnetic potential energy landscape due to the external magnetic field pulses without affecting the magnetic state of the thin film system. The magnetic particle velocity is adjustable in the range of 1-100 μm/s by the design of the substrate's magnetic field landscape (MFL), the particle-substrate distance, and the magnitude of the applied external magnetic field pulses. The agglomeration of magnetic particles is avoided by the intrinsic magnetostatic repulsion of particles due to the parallel alignment of the particles' magnetic moments perpendicular to the transport direction and parallel to the surface normal of the substrate during the particle motion. The transport mechanism is modeled by a quantitative theory based on the precise knowledge of the sample's MFL and the particle-substrate distance.

  12. Energy of nuclear-active particles in the 1-50 TeV energy range

    International Nuclear Information System (INIS)

    Kotlyarevskij, D.M.; Garsevanishvili, L.P.; Morozov, I.V.

    1979-01-01

    The ''TsKhRA-TsKARO'' installation designed for the investigation of cosmic beams interaction with nuclei in the energy range of 1-50 TeV is described. The installation comprises a magnetic spark spectrometer, photography system, ionization calorimeter and scintillating trigger device. The ionization calorimeter contains 12 rows of ionization chambers interlayed with 4 lead and 8 iron absorbers. The rows of ionization chambers of the calorimeter upper half are placed in the mutually-perpendicular direction to restore the direction and spatial situation of the electron-nuclear cascade. All in all the ionization calorimeter contains 100 channels of preintensifiers from which the information is transmitted to the terminal intensifiers and then to the storage cells. The aperture ratio of the whole installation (taking account of the upper chambers) is 0.5 m 2 /steradian, and the aperture ratio of the calorimeter together with the lower chambers is approximately 2 m 2 /steradian. Presented are integral spectra of the hadrons at the height of mountains and at the height of 2500 m above sea level obtained with the help of the installation described. Comparison of the number of charged and neutral particles recorded with the ''TsKhRA-TsKARO'' installation agrees well with the known ratio of charged and neutral cosmic hadrons on the heights of mountains n/c = 0.52+-0.05

  13. PAMELA’S MEASUREMENTS OF MAGNETOSPHERIC EFFECTS ON HIGH-ENERGY SOLAR PARTICLES

    Energy Technology Data Exchange (ETDEWEB)

    Adriani, O.; Bongi, M. [Department of Physics and Astronomy, University of Florence, I-50019 Sesto Fiorentino, Florence (Italy); Barbarino, G. C. [Department of Physics, University of Naples “Federico II,” I-80126 Naples (Italy); Bazilevskaya, G. A. [Lebedev Physical Institute, RU-119991 Moscow (Russian Federation); Bellotti, R.; Bruno, A. [University of Bari, I-70126 Bari (Italy); Boezio, M.; Bonvicini, V.; Carbone, R. [INFN, Sezione di Trieste, I-34149 Trieste (Italy); Bogomolov, E. A. [Ioffe Physical Technical Institute, RU-194021 St. Petersburg (Russian Federation); Bottai, S. [INFN, Sezione di Florence, I-50019 Sesto Fiorentino, Florence (Italy); Bravar, U. [Space Science Center, University of New Hampshire, Durham, NH (United States); Cafagna, F. [INFN, Sezione di Bari, I-70126 Bari (Italy); Campana, D. [INFN, Sezione di Naples, I-80126 Naples (Italy); Carlson, P. [KTH, Department of Physics, and the Oskar Klein Centre for Cosmoparticle Physics, AlbaNova University Centre, SE-10691 Stockholm (Sweden); Casolino, M.; De Donato, C. [INFN, Sezione di Rome “Tor Vergata,” I-00133 Rome (Italy); Castellini, G. [IFAC, I-50019 Sesto Fiorentino, Florence (Italy); Christian, E. R.; Nolfo, G. A. de, E-mail: georgia.a.denolfo@nasa.gov [Heliophysics Division, NASA Goddard Space Flight Center, Greenbelt, MD (United States); and others

    2015-03-01

    The nature of particle acceleration at the Sun, whether through flare reconnection processes or through shocks driven by coronal mass ejections, is still under scrutiny despite decades of research. The measured properties of solar energetic particles (SEPs) have long been modeled in different particle-acceleration scenarios. The challenge has been to disentangle the effects of transport from those of acceleration. The Payload for Antimatter Matter Exploration and Light-nuclei Astrophysics (PAMELA) instrument enables unique observations of SEPs including the composition and angular distribution of the particles about the magnetic field, i.e., pitch angle distribution, over a broad energy range (>80 MeV)—bridging a critical gap between space-based and ground-based measurements. We present high-energy SEP data from PAMELA acquired during the 2012 May 17 SEP event. These data exhibit differential anisotropies and thus transport features over the instrument rigidity range. SEP protons exhibit two distinct pitch angle distributions: a low-energy population that extends to 90° and a population that is beamed at high energies (>1 GeV), consistent with neutron monitor measurements. To explain a low-energy SEP population that exhibits significant scattering or redistribution accompanied by a high-energy population that reaches the Earth relatively unaffected by dispersive transport effects, we postulate that the scattering or redistribution takes place locally. We believe that these are the first comprehensive measurements of the effects of solar energetic particle transport in the Earth’s magnetosheath.

  14. Model experiments on direct conversion of charged particle energy for open-type reactors

    International Nuclear Information System (INIS)

    Dimitrov, S.K.; Makhin, A.V.; Mikhin, S.G.

    1984-01-01

    The energy recuperation of non monoenergetic charged particle flux ranning out from open-type magnetic mirror trap by particles braking in an electric field has been investigated. For more complex energy electron taking off adiabatic beam expansion in a dropping magnetic field after the trap has been realized. The recuperation system has been located in the mirror face part and consisted of electron collector, input diaphragm and antidinatron electrode. By calculation data based on measurements, the efficiency of real one-coelector energy convertor of ionic flows is to constitute 40-50%

  15. Dark clouds in particle physics and cosmology: the issues of dark matter and dark energy

    International Nuclear Information System (INIS)

    Zhang Xinmin

    2011-01-01

    Unveiling the nature of dark matter and dark energy is one of the main tasks of particle physics and cosmology in the 21st century. We first present an overview of the history and current status of research in cosmology, at the same time emphasizing the new challenges in particle physics. Then we focus on the scientific issues of dark energy, dark matter and anti-matter, and review the recent progress made in these fields. Finally, we discuss the prospects for future research on the experimental probing of dark matter and dark energy in China. (authors)

  16. A practical method for in-situ thickness determination using energy distribution of beta particles

    International Nuclear Information System (INIS)

    Yalcin, S.; Gurler, O.; Gundogdu, O.; Bradley, D.A.

    2012-01-01

    This paper discusses a method to determine the thickness of an absorber using the energy distribution of beta particles. An empirical relationship was obtained between the absorber thickness and the energy distribution of beta particles transmitted through. The thickness of a polyethylene radioactive source cover was determined by exploiting this relationship, which has largely been left unexploited allowing us to determine the in-situ cover thickness of beta sources in a fast, cheap and non-destructive way. - Highlights: ► A practical and in-situ unknown cover thickness determination ► Cheap and readily available compared to other techniques. ► Beta energy spectrum.

  17. 3D computation of the shape of etched tracks in CR-39 for oblique particle incidence and comparison with experimental results

    International Nuclear Information System (INIS)

    Doerschel, B.; Hermsdorf, D.; Reichelt, U.; Starke, S.; Wang, Y.

    2003-01-01

    Computation of the shape of etch pits needs to know the varying track etch rate along the particle trajectories. Experiments with alpha particles and 7 Li ions entering CR-39 detectors under different angles showed that this function is not affected by the inclination of the particle trajectory with respect to the normal on the detector surface. Track formation for oblique particle incidence can, therefore, be simulated using the track etch rates determined for perpendicular incidence. 3D computation of the track shape was performed applying a model recently described in literature. A special program has been written for computing the x,y,z coordinates of points on the etch pit walls. In addition, the etch pit profiles in sagittal sections as well as the contours of the etch pit openings on the detector surface have been determined experimentally. Computed and experimental results were in good agreement confirming the applicability of the 3D computational model in combination with the functions for the depth-dependent track etch rates determined experimentally

  18. Mixing rates of particle systems with energy exchange

    International Nuclear Information System (INIS)

    Grigo, A; Khanin, K; Szász, D

    2012-01-01

    A fundamental problem of non-equilibrium statistical mechanics is the derivation of macroscopic transport equations in the hydrodynamic limit. The rigorous study of such limits requires detailed information about rates of convergence to equilibrium for finite sized systems. In this paper, we consider the finite lattice {1, 2, …, N}, with an energy x i ∈ (0, ∞) associated with each site. The energies evolve according to a Markov jump process with nearest neighbour interaction such that the total energy is preserved. We prove that for an entire class of such models the spectral gap of the generator of the Markov process scales as O(N -2 ). Furthermore, we provide a complete classification of reversible stationary distributions of product type. We demonstrate that our results apply to models similar to the billiard lattice model considered in Gaspard and Gilbert (2009 J. Stat. Mech.: Theory Exp. 2009 24), and hence provide a first step in the derivation of a macroscopic heat equation for a microscopic stochastic evolution of mechanical origin. (paper)

  19. Effect of electron degeneracy on fast-particles energy deposition in dense plasma systems

    International Nuclear Information System (INIS)

    Johzaki, T.; Nakao, Y.; Nakashima, H.; Kudo, K.

    1997-01-01

    The effects of electron degeneracy on fast-particles energy deposition in dense plasmas are investigated by making transport calculations for the fast particles. It is found that the degeneracy substantially affects the profiles of energy deposition of 3.52-MeV α-particles. On the other hand, the effect on the energy deposition of 14.1-MeV neutrons is negligibly small because the recoil ions, which transfer the neutron energy to the plasma constituents, are produced in a whole plasma volume due to the long mean-free-path of neutrons. The coupled transport-hydrodynamic calculations show that these effects of degeneracy are negligible in the ignition and burn characteristics of central ignition D-T targets. (author)

  20. The United States Department of Energy (DOE) Computerized Accident/Incident Reporting System (CAIRS)

    International Nuclear Information System (INIS)

    Briscoe, G.J.

    1993-01-01

    The Department of Energy's (DOE) Computerized Accident/Incident Reporting System (CAIRS) is a comprehensive data base containing more than 50,000 investigation reports of injury/illness, property damage and vehicle accident cases representing safety data from 1975 to the present for more than 150 DOE contractor organizations. A special feature is that the text of each accident report is translated using a controlled dictionary and rigid sentence structure called Factor Relationship and Sequence of Events (FRASE) that enhances the ability to retrieve specific types of information and to perform detailed analyses. DOE summary and individual contractor reports are prepared quarterly and annually. In addition, ''Safety Performance Profile'' reports for individual organizations are prepared to provide advance information to appraisal teams, and special topical reports are prepared for areas of concern such as an increase in the number of security injuries or environmental releases. The data base is open to all DOE and Contractor registered users with no access restrictions other than that required by the Privacy Act

  1. Exclusive experiment on nuclei with backward emitted particles by electron-nucleus collision in ∼ 10 GeV energy range

    International Nuclear Information System (INIS)

    Saito, T.; Takagi, F.

    1994-01-01

    Since the evidence of strong cross section in proton-nucleus backward scattering was presented in the early of 1970 years, this phenomena have been interested from the point of view to be related to information on the short range correlation between nucleons or on high momentum components of the wave function of the nucleus. In the analysis of the first experiment on protons from the carbon target under bombardment by 1.5-5.7 GeV protons, indications are found of an effect analogous to scaling in high-energy interactions of elementary particles with protons. Moreover it is found that the function f(p 2 )/σ tot , which describes the spectra of the protons and deuterons emitted backward from nuclei in the laboratory system, does not depend on the energy and the type of the incident particle or on the atomic number of the target nucleus. In the following experiments the spectra of the protons emitted from the nuclei C, Al, Ti, Cu, Cd and Pb were measured in the inclusive reactions with incident particles of negative pions (1.55-6.2 GeV/c) and protons (6.2-9.0 GeV/C). The cross section f is described by f = E/p 2 d 2 σ/dpdΩ = C exp (-Bp 2 ), where p is the momentum of hadron. The function f depends linearly on the atomic weight A of the target nuclei. The slope parameter B is independent of the target nucleus and of the sort and energy of the bombarding particles. The invariant cross section ρ = f/σ tot is also described by exponential A 0 exp (-A 1p 2 ), where p becomes independent of energy at initial particle energies ≥ 1.5 GeV for C nucleus and ≥ 5 GeV for the heaviest of the investigated Pb nuclei

  2. Sensitivity determination of CR-39 from Normal and inclined incidence

    International Nuclear Information System (INIS)

    Abou, A.A.; El-Kheir, A.A.; Daas, A.F.; Awwad, Z.; Reda, A.M.

    2000-01-01

    An experimental study have been carried out on alpha- particle track opening (Major and minor axes) using alpha-particles of different energies incident with different angels in addition to the normal incidence. The sensitivity of CR-39 in present work is determined for each of normal and inclined incidence. The results indicated a difference in the sensitivity according to angle of incidence. The variation of alpha- particle tracks (major and minor axes) are calculated and compared with our measured values. Also, it is found that the sensitivity of CR-39 detector is change due to the storage time at room temperature

  3. Computed secondary-particle energy spectra following nonelastic neutron interactions with 12C for En between 15 and 60 MeV: Comparisons of results from two calculational methods

    International Nuclear Information System (INIS)

    Dickens, J.K.

    1991-04-01

    The organic scintillation detector response code SCINFUL has been used to compute secondary-particle energy spectra, dσ/dE, following nonelastic neutron interactions with 12 C for incident neutron energies between 15 and 60 MeV. The resulting spectra are compared with published similar spectra computed by Brenner and Prael who used an intranuclear cascade code, including alpha clustering, a particle pickup mechanism, and a theoretical approach to sequential decay via intermediate particle-unstable states. The similarities of and the differences between the results of the two approaches are discussed. 16 refs., 44 figs., 2 tabs

  4. Long-Pulse Operation and High-Energy Particle Confinement Study in ICRF Heating of LHD

    International Nuclear Information System (INIS)

    Mutoh, Takashi; Kumazawa, Ryuhei; Seki, Tetsuo

    2004-01-01

    Long-pulse operation and high-energy particle confinement properties were studied using ion cyclotron range of frequency (ICRF) heating for the Large Helical Device. For the minority-ion mode, ions with energies up to 500 keV were observed by concentrating the ICRF heating power near the plasma axis. The confinement of high-energy particles was studied using the power-modulation technique. This confirmed that the confinement of high-energy particles was better with the inward-shifted configuration than with the normal configuration. This behavior was the same for bulk plasma confinement. Long-pulse operation for more than 2 min was achieved during the experimental program in 2002. This was mainly due to better confinement of the helically trapped particles and accumulation of fewer impurities in the region of the plasma core, in conjunction with substantial hardware improvements. Currently, the plasma operation time is limited by an unexpected density rise due to outgassing from the chamber materials. The temperature of the local carbon plates of the divertor exceeded 400 deg, C, and a charge-coupled device camera observed the hot spots. The hot spot pattern was well explained by a calculation of the accelerated-particle orbits, and those accelerated particles came from outside the plasma near the ICRF antenna

  5. Probing the stability of superheavy dark matter particles with high-energy neutrinos

    International Nuclear Information System (INIS)

    Esmaili, Arman; Peres, O.L.G.

    2012-01-01

    Full text: There is currently mounting evidence for the existence of dark matter in our Universe from various astrophysical and cosmological observations, but the two of the most fundamental properties of the dark matter particle, the mass and the lifetime, are only weakly constrained by the astronomical and cosmological evidence of dark matter. We derive lower limits on the lifetime of dark matter particles with masses in the range 10 TeV - 10 18 GeV from the non-observation of ultrahigh energy neutrinos in the AMANDA, IceCube, Auger and ANITA experiments. All these experiments probe different energy windows and perfectly complement each other. For dark matter particles which produce neutrinos in a two body or a three body decay, we find that the dark matter lifetime must be longer than ∼ 10 26 s for masses between 10 TeV and the Grand Unification scale. We will consider various scenarios where the decay of the dark matter particle produces high energy neutrinos. Neutrinos travel in the Universe without suffering an appreciable attenuation, even for EeV neutrinos, in contrast to photons which rapidly lose their energy via pair production. This remarkable property makes neutrinos a very suitable messenger to constrain the lifetime of superheavy dark matter particles. Finally, we also calculate, for concrete particle physics scenarios, the limits on the strength of the interactions that induce the dark matter decay. (author)

  6. Calculation of nuclear data for incident energies to 200 MeV with the FKK-GNASH code system

    International Nuclear Information System (INIS)

    Chadwick, M.B.; Young, P.G.

    1993-02-01

    We describe how the FKK-GNASH code system has been extended to calculate nucleon-induced reactions up to 200 MeV, and used to predict (p,xn) and (p,xp) cross sections on 208 Pb at incident energies of 25, 45, 80 and 160 MeV, for an intermediate energy code intercomparison. Details of the reaction mechanisms calculated by FKK-GNASH are given, and the calculational procedure is described

  7. Elementary particles and high energy phenomena. Progress report

    International Nuclear Information System (INIS)

    Ford, W.T.

    1984-01-01

    During the past year, the MAC collaboration continued accumulating data at PEP and published several results. Included in the results are the lifetime measurement of b quarks; the observation of electroweak interference effects using Bhabba, μμ, and tau tau scattering, a precise measurement of R, observations of direct photons, and a study of energy-energy correlations in multihadron events. For MkII/SLC, a vertex detector system chamber using proportional drift tubes is under construction.The Tagged Photon Spectrometer group has published results and is preparing a new experiment, E-691, to be run in January, 1985. The published results of E-516 include a study of J/psi photoproduction and a study of D 0 → K - π + π 0 . An analysis of Λ 0 anti Λ 0 , and K 0 inclusive photoproduction has recently been completed and is being prepared for publication. Design work and preparation for prototype development has begun on the end cap drift chambers for SLD. Experiment E-400, Hadronic Charm Production, accumulated data during the first two SAVER runs at Fermilab and is now involved in data analysis. E-687, a photoproduction experiment at Fermilab, has begun construction of an electromagnetic calorimeter to measure the energy and postion photons and electrons. Novel forms of supersymmetry breaking were investigated. The anomaly and its relation to the construction of finite supersymmetric theories was studied. A long project was completed on the relation between the gluon condensate in QCD and on effective gluon mass. A series of papers was published on numerical studies of quantum Hamiltonian field theories. Studies of the confinement-deconfinement phase transition in QCD at high temperature were conducted, with applications both to the early universe and to the phenomenogy of ultrarelativistic nucleus-nucleus collisons

  8. Structural properties and growth evolution of diamond-like carbon films with different incident energies: A molecular dynamics study

    International Nuclear Information System (INIS)

    Li, Xiaowei; Ke, Peiling; Zheng, He; Wang, Aiying

    2013-01-01

    Structural properties and growth evolution of diamond-like carbon (DLC) films with different incident energies were investigated systematically by the molecular dynamics simulation using a Tersoff interatomic potential for carbon-carbon interaction. The results revealed that the density, sp 3 fraction and residual compressive stress as a function of incident energy increased firstly and then decreased; when the incident energy was 70 eV/atom, the density could reach to 3.0 g/cm 3 with the maximal compressive stress of 15.5 GPa. Structure analysis indicated that the deviation of both bond angles and lengths from the equilibrium position led to the generation of a large residual stress, while the high compressive stress mainly attributed to the decrease of both bond angles and lengths among carbon atoms. The growth of DLC films underwent a formation process of “Line-Net” structure accompanied with the interaction of many atomic motion mechanisms, and the “Point” stage was only found for DLC films with low incident energy.

  9. Simulation of hadron multiple production by cosmic-ray protons in the incident energy region of 1015 eV

    International Nuclear Information System (INIS)

    Takatsuka, Ichiro

    1984-01-01

    The simulation studies of the unusual cosmic ray families found by the experiment at Mt. Chacaltaya were performed. Those families have a larger number of hadrons than the normal families, or are the families with big transverse extension. The former is called Centauro or Mini-centauro, and the latter is called Binocular and Chiron. In the first simulation, the process was calculated, in which the Lorentz transformation of π-meson multiple production (C-jet) in the energy region of 10 14 eV was made, and the jet with raised energy was combined, and the families were formed. The second simulation was made for the energy region more than 300 TeV, in which the nucleon-antinucleon multiple production with large transverse momentum and the B particle multiple production with larger transverse momentum were assumed. The data used were the C-jet data observed at Mt. Chacaltaya. For the simulation, all the primary particles were considered to be protons. The results of the present simulation study showed that the families with strong hadron components observed at Mt. Chacaltaya might be the new type hadron multiple production such as nucleon-antinucleon multiple production or B-particle multiple production. The total energy of all the families increased with the energy of the primary particles. There are a few families having the same extent of energy and spread as the Chiron. (Kato, T.)

  10. Shocks from high-energy nuclear-interacting particles in the mountain Chakaltajya

    Energy Technology Data Exchange (ETDEWEB)

    Kamata, K [Tokyo Univ. (Japan)

    1975-06-01

    Experimental investigations of extensive air showers at the height of 5200 m above the sea level have been performed. The behaviour of high energy nuclear active particles in the cores of the showers has been studied using the nuclear knock-on method. The cross section of the proton inelastic interaction with the air is shown to increase with energy in the energy range of 3-9 TeV.

  11. Development of the MICROMEGAS Detector for Measuring the Energy Spectrum of Alpha Particles by using a 241-Am Source

    CERN Document Server

    Kim, Do Yoon; Shin, Jae Won; Park, Tae-Sun; Hong, Seung-Woo; Andriamonje, Samuel; Kadi, Yacine; Tenreiro, Claudio

    2016-01-01

    We have developed MICROMEGAS (MICRO MEsh GASeous) detectors for detecting {\\alpha} particles emitted from an 241-Am standard source. The voltage applied to the ionization region of the detector is optimized for stable operation at room temperature and atmospheric pressure. The energy of {\\alpha} particles from the 241-Am source can be varied by changing the flight path of the {\\alpha} particle from the 241 Am source. The channel numbers of the experimentally-measured pulse peak positions for different energies of the {\\alpha} particles are associated with the energies deposited by the alpha particles in the ionization region of the detector as calculated by using GEANT4 simulations; thus, the energy calibration of the MICROMEGAS detector for {\\alpha} particles is done. For the energy calibration, the thickness of the ionization region is adjusted so that {\\alpha} particles may completely stop in the ionization region and their kinetic energies are fully deposited in the region. The efficiency of our MICROMEGA...

  12. High-energy particle Monte Carlo at Los Alamos

    International Nuclear Information System (INIS)

    Prael, R.E.

    1985-01-01

    A major computational effort at Los Alamos has been the development of a code system based on the HETC code for the transport of nucleons, pions, and muons. The Los Alamos National Laboratory version of HETC utilizes MCNP geometry and interfaces with MCNP for the transport of neutrons below 20 MeV and photons at any energy. A major recent effort has been the development of the PHT code for treating the gamma cascade in excited nuclei (the residual nuclei from an HETC calculation) by the Monte Carlo method to generate a photon source for MCNP. The HETC/MCNP code system has been extensively used for design studies of accelerator targets and shielding, including the design of LAMPF-II. It is extensively used for the design and analysis of accelerator experiments. Los Alamos National Laboratory has been an active member of the International Collaboration on Advanced Neutron Sources; as such we engage in shared code development and computational efforts. In the past few years, additional effort has been devoted to the development of a Chen-model intranuclear cascade code (INCA1) featuring a cluster model for the nucleus and deuteron pickup reactions. Concurrently, the INCA2 code for the breakup of light, excited nuclei using the Fermi breakup model has been developed. Together, they have been used for the calculation of neutron and proton cross sections in the energy ranges appropriate to medical accelerators, and for the computation of tissue kerma factors

  13. Fully integrated CMOS pixel detector for high energy particles

    International Nuclear Information System (INIS)

    Vanstraelen, G.; Debusschere, I.; Claeys, C.; Declerck, G.

    1989-01-01

    A novel type of position and energy sensitive, monolithic pixel array with integrated readout electronics is proposed. Special features of the design are a reduction of the number of output channels and of the amount of output data, and the use of transistors on the high resistivity silicon. The number of output channels for the detector array is reduced by handling in parallel a number of pixels, chosen as a function of the time resolution required for the system, and by the use of an address decoder. A further reduction of data is achieved by reading out only those pixels which have been activated. The pixel detector circuit will be realized in a 3 μm p-well CMOS process, which is optimized for the full integration of readout electronics and detector diodes on high resistivity Si. A retrograde well is formed by means of a high energy implantation, followed by the appropriate temperature steps. The optimization of the well shape takes into account the high substrate bias applied during the detector operation. The design is largely based on the use of MOS transistors on the high resistivity silicon itself. These have proven to perform as well as transistors on standard doped substrate. The basic building elements as well as the design strategy of the integrated pixel detector are presented in detail. (orig.)

  14. On the Frequency Distribution of Neutral Particles from Low-Energy Strong Interactions

    Directory of Open Access Journals (Sweden)

    Federico Colecchia

    2017-01-01

    Full Text Available The rejection of the contamination, or background, from low-energy strong interactions at hadron collider experiments is a topic that has received significant attention in the field of particle physics. This article builds on a particle-level view of collision events, in line with recently proposed subtraction methods. While conventional techniques in the field usually concentrate on probability distributions, our study is, to our knowledge, the first attempt at estimating the frequency distribution of background particles across the kinematic space inside individual collision events. In fact, while the probability distribution can generally be estimated given a model of low-energy strong interactions, the corresponding frequency distribution inside a single event typically deviates from the average and cannot be predicted a priori. We present preliminary results in this direction and establish a connection between our technique and the particle weighting methods that have been the subject of recent investigation at the Large Hadron Collider.

  15. What could we learn about high energy particle physics from cosmological observations at largest spatial scales ?

    Directory of Open Access Journals (Sweden)

    Gorbunov Dmitry

    2017-01-01

    Full Text Available The very well known example of cosmology testing particle physics is the number of relativistic particles (photons and three active neutrinos within the Standard Model at primordial nucleosynthesis. These days the earliest moment we can hope to probe with present cosmological data is the early time inflation. The particle physics conditions there and now are different because of different energy scales and different values of the scalar fields, that usually prohibits a reliable connection between the particle physics parameters at the two interesting epochs. The physics at the highest energy scales may be probed with observations at the largest spatial scales (just somewhat smaller than the size of the visible Universe. However, we are not (yet ready to make the tests realistic, because of lack of a self-consistent theoretical description of the presently favorite cosmological models to be valid right after inflation.

  16. Wave-particle energy exchange directly observed in a kinetic Alfvén-branch wave.

    Science.gov (United States)

    Gershman, Daniel J; F-Viñas, Adolfo; Dorelli, John C; Boardsen, Scott A; Avanov, Levon A; Bellan, Paul M; Schwartz, Steven J; Lavraud, Benoit; Coffey, Victoria N; Chandler, Michael O; Saito, Yoshifumi; Paterson, William R; Fuselier, Stephen A; Ergun, Robert E; Strangeway, Robert J; Russell, Christopher T; Giles, Barbara L; Pollock, Craig J; Torbert, Roy B; Burch, James L

    2017-03-31

    Alfvén waves are fundamental plasma wave modes that permeate the universe. At small kinetic scales, they provide a critical mechanism for the transfer of energy between electromagnetic fields and charged particles. These waves are important not only in planetary magnetospheres, heliospheres and astrophysical systems but also in laboratory plasma experiments and fusion reactors. Through measurement of charged particles and electromagnetic fields with NASA's Magnetospheric Multiscale (MMS) mission, we utilize Earth's magnetosphere as a plasma physics laboratory. Here we confirm the conservative energy exchange between the electromagnetic field fluctuations and the charged particles that comprise an undamped kinetic Alfvén wave. Electrons confined between adjacent wave peaks may have contributed to saturation of damping effects via nonlinear particle trapping. The investigation of these detailed wave dynamics has been unexplored territory in experimental plasma physics and is only recently enabled by high-resolution MMS observations.

  17. Wave-Particle Energy Exchange Directly Observed in a Kinetic Alfven-Branch Wave

    Science.gov (United States)

    Gershman, Daniel J.; F-Vinas, Adolfo; Dorelli, John C.; Boardsen, Scott A. (Inventor); Avanov, Levon A.; Bellan, Paul M.; Schwartz, Steven J.; Lavraud, Benoit; Coffey, Victoria N.; Chandler, Michael O.; hide

    2017-01-01

    Alfven waves are fundamental plasma wave modes that permeate the universe. At small kinetic scales they provide a critical mechanism for the transfer of energy between electromagnetic fields and charged particles. These waves are important not only in planetary magnetospheres, heliospheres, and astrophysical systems, but also in laboratory plasma experiments and fusion reactors. Through measurement of charged particles and electromagnetic fields with NASAs Magnetospheric Multiscale (MMS) mission, we utilize Earths magnetosphere as a plasma physics laboratory. Here we confirm the conservative energy exchange between the electromagnetic field fluctuations and the charged particles that comprise an undamped kinetic Alfven wave. Electrons confined between adjacent wave peaks may have contributed to saturation of damping effects via non-linear particle trapping. The investigation of these detailed wave dynamics has been unexplored territory in experimental plasma physics and is only recently enabled by high-resolution MMS observations.

  18. Three particle scattering at high energies in a model with eikonal Hamiltonian

    International Nuclear Information System (INIS)

    Kharchenko, V.F.; Kuzmichev, V.E.

    1980-04-01

    The three particle collision process 3 → 3 with relative motion of each pair of particles described by a model with eikonal Hamiltonian is investigated. No additional restrictions on the motion of the particles (such as the fixed scattering centre approximation) are imposed. A unique, exact analytical solution of the three-particle problem is then shown to exist. An explicit expression for the 3 → 3 amplitude in the general case off the energy shell is obtained as the result of the exact summation of the multiple scattering series. It is shown that this series terminates on the energy shell. A new formula for the mutual cancellation of terms in the multiple scattering series in a model with eikonal Hamiltonian is found. (orig.)

  19. Universal behavior of charged particle production in heavy ion collisions at RHIC energies

    Science.gov (United States)

    Steinberg, Peter A.; Back, B. B.; Baker, M. D.; Barton, D. S.; Betts, R. R.; Ballintijn, M.; Bickley, A. A.; Bindel, R.; Budzanowski, A.; Busza, W.; Carroll, A.; Decowski, M. P.; García, E.; George, N.; Gulbrandsen, K.; Gushue, S.; Halliwell, C.; Hamblen, J.; Heintzelman, G. A.; Henderson, C.; Hofman, D. J.; Hollis, R. S.; Holyński, R.; Holzman, B.; Iordanova, A.; Johnson, E.; Kane, J. L.; Katzy, J.; Khan, N.; Kucewicz, W.; Kulinich, P.; Kuo, C. M.; Lin, W. T.; Manly, S.; McLeod, D.; Michałowski, J.; Mignerey, A. C.; Nouicer, R.; Olszewski, A.; Pak, R.; Park, I. C.; Pernegger, H.; Reed, C.; Remsberg, L. P.; Reuter, M.; Roland, C.; Roland, G.; Rosenberg, L.; Sagerer, J.; Sarin, P.; Sawicki, P.; Skulski, W.; Steadman, S. G.; Steinberg, P.; Stephans, G. S. F.; Stodulski, M.; Sukhanov, A.; Tang, J.-L.; Teng, R.; Trzupek, A.; Vale, C.; van Nieuwenhuizen, G. J.; Verdier, R.; Wadsworth, B.; Wolfs, F. L. H.; Wosiek, B.; Woźniak, K.; Wuosmaa, A. H.; Wysłouch, B.; Phobos Collaboration

    2003-04-01

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

  20. Heavy inertial particles in turbulent flows gain energy slowly but lose it rapidly.

    Science.gov (United States)

    Bhatnagar, Akshay; Gupta, Anupam; Mitra, Dhrubaditya; Pandit, Rahul

    2018-03-01

    We present an extensive numerical study of the time irreversibility of the dynamics of heavy inertial particles in three-dimensional, statistically homogeneous, and isotropic turbulent flows. We show that the probability density function (PDF) of the increment, W(τ), of a particle's energy over a time scale τ is non-Gaussian, and skewed toward negative values. This implies that, on average, particles gain energy over a period of time that is longer than the duration over which they lose energy. We call this slow gain and fast loss. We find that the third moment of W(τ) scales as τ^{3} for small values of τ. We show that the PDF of power-input p is negatively skewed too; we use this skewness Ir as a measure of the time irreversibility and we demonstrate that it increases sharply with the Stokes number St for small St; this increase slows down at St≃1. Furthermore, we obtain the PDFs of t^{+} and t^{-}, the times over which p has, respectively, positive or negative signs, i.e., the particle gains or loses energy. We obtain from these PDFs a direct and natural quantification of the slow gain and fast loss of the energy of the particles, because these PDFs possess exponential tails from which we infer the characteristic loss and gain times t_{loss} and t_{gain}, respectively, and we obtain t_{loss}energy occurs with greater probability in the strain-dominated region than in the vortical one; in contrast, the slow gain in the energy of the particles is equally likely in vortical or strain-dominated regions of the flow.

  1. Angular dependence of energy and particle fluxes in a magnetized plasma

    International Nuclear Information System (INIS)

    Koch, B.; Bohmeyer, W.; Fussmann, G.

    2005-01-01

    A flat probe allowing simultaneous measurements of energy flux and current density as functions of a bias voltage was rotated in a spatially homogeneous plasma. The experiments were conducted at the PSI-2 facility, a linear divertor simulator with moderate magnetic field strength. Sheath parameters (ion current density j i , floating potential U f , energy flux density q, ion energy reflection coefficient R E and sheath energy transmission coefficient γ) were determined as functions of the angle α between the probe surface normal and the magnetic field. A geometric model has been developed to explain the ion flux density at grazing incidence

  2. Particle physics and dark energy. Beyond classical dynamics

    International Nuclear Information System (INIS)

    Garny, Mathias

    2008-01-01

    In this work, quantum corrections to classical equations of motion are investigated for dynamical models of dark energy featuring a time-evolving quintessence scalar field. Employing effective quantum field theory, the robustness of tracker quintessence potentials against quantum corrections as well as their impact on cosmological observables are discussed. Furthermore, it is demonstrated that a rolling quintessence field can also play an important role for baryogenesis in the early universe. The macroscopic time-evolution of scalar quantum fields can be described from first principles within nonequilibrium quantum field theory based on Kadanoff-Baym equations derived from the 2PI effective action. A framework for the nonperturbative renormalization of Kadanoff-Baym equations is provided. Renormalized Kadanoff-Baym equations are proposed and their finiteness is shown for a special case. (orig.)

  3. Particle physics and dark energy. Beyond classical dynamics

    Energy Technology Data Exchange (ETDEWEB)

    Garny, Mathias

    2008-10-24

    In this work, quantum corrections to classical equations of motion are investigated for dynamical models of dark energy featuring a time-evolving quintessence scalar field. Employing effective quantum field theory, the robustness of tracker quintessence potentials against quantum corrections as well as their impact on cosmological observables are discussed. Furthermore, it is demonstrated that a rolling quintessence field can also play an important role for baryogenesis in the early universe. The macroscopic time-evolution of scalar quantum fields can be described from first principles within nonequilibrium quantum field theory based on Kadanoff-Baym equations derived from the 2PI effective action. A framework for the nonperturbative renormalization of Kadanoff-Baym equations is provided. Renormalized Kadanoff-Baym equations are proposed and their finiteness is shown for a special case. (orig.)

  4. Lattice Design in High-energy Particle Accelerators

    CERN Document Server

    Holzer, B.J.

    2014-01-01

    This lecture gives an introduction into the design of high-energy storage ring lattices. Applying the formalism that has been established in transverse be am optics, the basic principles of the development of a magnet lattice are explained and the characteristics of the resulting magnet structure are discussed. The periodic assembly of a storage ring cell with its boundary conditions concerning stability and scaling of the beam optics parameters is addressed as well as special lattice insertions such as drifts, mini beta sections, dispersion suppressors, etc. In addition to the exact calculations that are indispensable for a rigorous treatment of the matter, scaling rules are shown and simple rules of thumb are included that enable the lattice designer to do the first estimates and get the basic numbers ‘ on the back of an envelope.

  5. Practical aspects of shielding high-energy particle accelerators

    International Nuclear Information System (INIS)

    Thomas, R.H.; Univ. of California, Berkeley, CA

    1993-09-01

    The experimental basis of shielding design for high-energy accelerators that has been established over the past thirty years is described. Particular emphasis is given to the design of large accelerators constructed underground. The first data obtained from cosmic-ray physics were supplemented by basic nuclear physics. When these data proved insufficient, experiments were carried out and interpreted by several empirical formulae -- the most successful of which has been the Moyer Model. This empirical model has been used successfully to design the shields of most synchrotrons currently in operation, and is still being used in preliminary design and to check the results of neutron transport calculations. Accurate shield designs are needed to reduce external radiation levels during accelerator operations and to minimize environmental impacts such as open-quotes skyshineclose quotes and the production of radioactivity in groundwater. Examples of the cost of minimizing such environmental impacts are given

  6. Introduction to the study of particle accelerators. Atomic, nuclear and high energy physics for engineers

    International Nuclear Information System (INIS)

    Warnecke, R.R.

    1975-01-01

    This book is destined for engineers taking part in the design building and running of nuclear physics and high-energy physics particle accelerators. It starts with some notions on the theory of relativity, analytical and statistical mechanics and quantum mechanics. An outline of the properties of atomic nuclei, the collision theory and the elements of gaseous plasma physics is followed by a discussion on elementary particles: characteristic parameters, properties, interactions, classification [fr

  7. Higgs radiation off top particles in high-energy e+e- colliders

    International Nuclear Information System (INIS)

    Djouadi, A.; Technische Hochschule Aachen; Kalinowski, J.; Zerwas, P.M.

    1991-10-01

    Higgs particles can be radiated off heavy top quarks which will be produced copiously in high energy e + e - colliders. This process can be used to measure the Higgs-top quark coupling. We present the cross section for the production of Higgs bosons in the Standard Model. In addition we have studied the production of neutral and charged Higgs particles in association with heavy fermions in the Minimal Supersymmetric Standard Model. (orig.)

  8. Experimental investigations in particle physics at intermediate energies

    International Nuclear Information System (INIS)

    Auerbach, L.B.; Highland, V.L.; Martoff, C.J.; McFarlane, K.W.; Guss, C.; Kettell, S.

    1991-01-01

    The major elements of this project continues to be on fundamental symmetries and parameters of the Standard Model. The projects in the current period have been BNL E791 (a search for the decay K L 0 → μe, which would violate the rule of separate lepton number conservation), test of an upgrade proposal (E871), and LSND, a neutrino experiment at LAMPF. For E791, data taking was completed in June 1990, and preliminary results are now available for the decays K L 0 → μe and K L 0 → μμfrom the entire data set. The data for decay K L 0 → ee are still being analysed. These are an upper limit for the branching fraction for K L 0 → μe of 3.5 x 10 -11 (90% C.L.). From the 1990 data alone, we have a new (preliminary) value of the branching fraction for K L 0 → μμ of (6.96±0. 4±0.22) x 10 -9 , with a sample of 349 events. Combining this with earlier data gives (6.96±0.34) x 10 9 , by far the most precise value. The limit on the decay K L 0 → μe places a lower limit on the mass of a new particle mediating such decays of 85 TeV. The LSND (Large Scintillator Neutrino Detector), a search for neutrino oscillations at LAMPF, has been approved, and is now underway. Other neutrino work at Los Alamos, E764, has resulted in a final publication. This includes the best, measurement of ν-nuclear scattering, in ν mu 12 C inclusive cross sections. The measurement of the cross section for the exclusive reaction ν mu12 C → μ -12 N is unique. In a new development, Dr. Martoff has established a facility for fabrication of superconducting detectors of nuclear radiation; the equipment has been funded and is partly installed. Planned uses include scattering for 'Dark Matter.' In summary, the objectives for this year have been met

  9. Inclusive break-up reactions of 6Li at an incident energy of 26 MeV/nucleon

    International Nuclear Information System (INIS)

    Shyam, R.; Machner, H.; Neumann, B.; Rebel, H.; Gils, H.J.; Planeta, R.; Buschmann, J.; Klewe-Nebenius, H.; Zagromski, S.

    1982-01-01

    Inclusive charged particle spectra were measured from nuclear reactions induced by 156 MeV 6 Li on 40 Ca. At forward angles the spectra exhibit broad break-up distributions centered around the energy corresponding to the beam velocity. The double differential cross sections together with previous results for a 208 Pb target were analyzed in the framework of the DWBA approach to projectile break-up taking into account elastic and inelastic reactions of the break-up fragments. The high energy tails of the background due to preequilibrium emission of complex charged particles were estimated on the basis of the coalescence model. (orig.) [de

  10. Inclusive break-up reactions of 6Li at an incident energy of 26 MeV/nucleon

    International Nuclear Information System (INIS)

    Neumann, B.; Rebel, H.; Gils, H.J.; Planeta, R.; Buschmann, J.; Klewe-Nebenius, H.; Zagromski, S.; Shyam, R.; Machner, H.

    1982-01-01

    Inclusive charged particle spectra were measured from nuclear reactions induced by 156 MeV 6 Li on 40 Ca. At forward angles the spectra exhibit broad break-up distributions centered around the energy corresponding to the beam velocity. The double differential cross sections together with previous results for a 208 Pb target were analyzed in the framework of the DWBA approach to projectile break-up taking into account elastic and inelastic reactions of the break-up fragments. The high energy tails of the background due to preequilibrium emission of complex charged particles were estimated on the basis of the coalescence model. (orig.)

  11. Silicon surface barrier detector and study of energy spectrum of alpha particles from radioactive source

    International Nuclear Information System (INIS)

    Verma, S.D.; Sinha, Vijaya

    1986-01-01

    The principles of working of three commonly used radiation detectors, namely ionization chambers, scintillation counters with photomultiplier tube (PMT) systems and semiconductor detectors are briefly discussed. Out of the semiconductor detectors, the silicon surface barrier (SSB) detector has distinct advantages for detection of radiations, alpha particles in particular. The experimental setup to obtain the energy spectrum of alpha particles from 241 Am source using SSB fabricated in the Physics Department of Gujarat University, Ahmedabad is described. Its performance is compared with scintillation counter using PMT. SSB detector shows a sharp peak of #approx # 3 per cent energy resolution. The factors affecting the peak, namely, electronic noise, source dependent factors and detector-dependent factors are discussed. A method of calibrating SSB detectors based on energy loss mechanism of alpha particles in thin absorbers is described. Applications of such detectors are indicated. (M.G.B.)

  12. An approximate analytical solution for the energy distribution of beta particles transmitted through metal foils

    International Nuclear Information System (INIS)

    Gurler, O.; Yalcin, S.; Gultekin, A.; Kaynak, G.; Gundogdu, O.

    2006-01-01

    The energy distributions of beta particles which penetrated a certain matter thickness were studied experimentally and theoretically by using a surface barrier solid state detector. A valid theoretical expression based on average values between energy and distance traveled during the slowing down of the electron was obtained. Two analytical expressions were proposed; one for the energy distribution of monoenergetic electrons which penetrated a certain matter thickness, and one for the response function in the detector for monoenergetic electrons detected with its entire energy. Response functions of the detector for beta particles emitted from 204 Tl isotope which penetrated a certain matter thickness were obtained for two different aluminum thicknesses, and the results were discussed by comparing with experimental energy spectra

  13. An approximate analytical solution for the energy distribution of beta particles transmitted through metal foils

    Energy Technology Data Exchange (ETDEWEB)

    Gurler, O. [Faculty of Arts and Sciences, University of Uludag, 16059 Bursa (Turkey)]. E-mail: ogurler@uludag.edu.tr; Yalcin, S. [Gazi University Kastamonu, Education Faculty, 37200 Kastamonu (Turkey); Gultekin, A. [Faculty of Arts and Sciences, University of Uludag, 16059 Bursa (Turkey); Kaynak, G. [Faculty of Arts and Sciences, University of Uludag, 16059 Bursa (Turkey); Gundogdu, O. [School of Engineering, University of Surrey, Guildford GU2 7XH (United Kingdom)

    2006-04-15

    The energy distributions of beta particles which penetrated a certain matter thickness were studied experimentally and theoretically by using a surface barrier solid state detector. A valid theoretical expression based on average values between energy and distance traveled during the slowing down of the electron was obtained. Two analytical expressions were proposed; one for the energy distribution of monoenergetic electrons which penetrated a certain matter thickness, and one for the response function in the detector for monoenergetic electrons detected with its entire energy. Response functions of the detector for beta particles emitted from {sup 204}Tl isotope which penetrated a certain matter thickness were obtained for two different aluminum thicknesses, and the results were discussed by comparing with experimental energy spectra.

  14. Modeling of MeV alpha particle energy transfer to lower hybrid waves

    International Nuclear Information System (INIS)

    Schivell, J.; Monticello, D.A.; Fisch, N.; Rax, J.M.

    1993-10-01

    The interaction between a lower hybrid wave and a fusion alpha particle displaces the alpha particle simultaneously in space and energy. This results in coupled diffusion. Diffusion of alphas down the density gradient could lead to their transferring energy to the wave. This could, in turn, put energy into current drive. An initial analytic study was done by Fisch and Rax. Here the authors calculate numerical solutions for the alpha energy transfer and study a range of conditions that are favorable for wave amplification from alpha energy. They find that it is possible for fusion alpha particles to transfer a large fraction of their energy to the lower hybrid wave. The numerical calculation shows that the net energy transfer is not sensitive to the value of the diffusion coefficient over a wide range of practical values. An extension of this idea, the use of a lossy boundary to enhance the energy transfer, is investigated. This technique is shown to offer a large potential benefit

  15. Ionisation differential cross section measurements for N2 at low incident energy in coplanar and non-coplanar geometries

    International Nuclear Information System (INIS)

    Sakaamini, Ahmad; Murray, Andrew James; Amami, Sadek; Madison, Don; Ning, Chuangang

    2016-01-01

    Ionisation triple differential cross sections have been determined experimentally and theoretically for the neutral molecule N 2 over a range of geometries from coplanar to the perpendicular plane. Data were obtained at incident electron energies ∼10 and ∼20 eV above the ionisation potential of the 3 σ g , 1 π u and 2 σ g states, using both equal and non-equal outgoing electron energies. The data were taken with the incident electron beam in the scattering plane ( ψ = 0°), at 45° to this plane and orthogonal to the plane ( ψ = 90°). The set of nine measured differential cross sections at a given energy were then inter-normalised to each other. The data are compared to new calculations using various distorted wave methods, and differences between theory and experiment are discussed. (paper)

  16. A systematics of optical model compound nucleus formation cross sections for neutrons, proton, deuteron, 3He and alpha particle incidents

    International Nuclear Information System (INIS)

    Murata, Toru

    2000-01-01

    Simple formulae to reproduce the optical model compound nucleus formation cross sections for neutron, proton, deuteron, triton, 3 He and alpha particles are presented for target nuclei of light to medium weight mass region. (author)

  17. Heavy inertial particles in turbulent flows gain energy slowly but lose it rapidly

    Science.gov (United States)

    Bhatnagar, Akshay; Gupta, Anupam; Mitra, Dhrubaditya; Pandit, Rahul

    2018-03-01

    We present an extensive numerical study of the time irreversibility of the dynamics of heavy inertial particles in three-dimensional, statistically homogeneous, and isotropic turbulent flows. We show that the probability density function (PDF) of the increment, W (τ ) , of a particle's energy over a time scale τ is non-Gaussian, and skewed toward negative values. This implies that, on average, particles gain energy over a period of time that is longer than the duration over which they lose energy. We call this slow gain and fast loss. We find that the third moment of W (τ ) scales as τ3 for small values of τ . We show that the PDF of power-input p is negatively skewed too; we use this skewness Ir as a measure of the time irreversibility and we demonstrate that it increases sharply with the Stokes number St for small St; this increase slows down at St≃1 . Furthermore, we obtain the PDFs of t+ and t-, the times over which p has, respectively, positive or negative signs, i.e., the particle gains or loses energy. We obtain from these PDFs a direct and natural quantification of the slow gain and fast loss of the energy of the particles, because these PDFs possess exponential tails from which we infer the characteristic loss and gain times tloss and tgain, respectively, and we obtain tlossprobability in the strain-dominated region than in the vortical one; in contrast, the slow gain in the energy of the particles is equally likely in vortical or strain-dominated regions of the flow.

  18. Particle production at energies available at the CERN Large Hadron Collider within an evolutionary model

    Science.gov (United States)

    Sinyukov, Yu. M.; Shapoval, V. M.

    2018-06-01

    The particle yields and particle number ratios in Pb+Pb collisions at the CERN Large Hadron Collider (LHC) energy √{sN N}=2.76 TeV are described within the integrated hydrokinetic model (iHKM) at two different equations of state (EoS) for quark-gluon matter and the two corresponding hadronization temperatures T =165 MeV and T =156 MeV. The role of particle interactions at the final afterburner stage of the collision in the particle production is investigated by means of comparison of the results of full iHKM simulations with those where the annihilation and other inelastic processes (except for resonance decays) are switched off after hadronization/particlization, similarly as in the thermal models. An analysis supports the picture of continuous chemical freeze-out in the sense that the corrections to the sudden chemical freeze-out results, which arise because of the inelastic reactions at the subsequent evolution times, are noticeable and improve the description of particle number ratios. An important observation is that, although the particle number ratios with switched-off inelastic reactions are quite different at different particlization temperatures which are adopted for different equations of state to reproduce experimental data, the complete iHKM calculations bring very close results in both cases.

  19. Production of low energy gamma rays by neutron interactions with fluorine for incident neutron energies between 0.1 and 20 MeV

    International Nuclear Information System (INIS)

    Morgan, G.L.; Dickens, J.K.

    1975-06-01

    Differential cross sections for the production of low-energy gamma rays (less than 240 keV) by neutron interactions in fluorine have been measured for neutron energies between 0.1 and 20 MeV. The Oak Ridge Electron Linear Accelerator was used as the neutron source. Gamma rays were detected at 92 0 using an intrinsic germanium detector. Incident neutron energies were determined by time-of-flight techniques. Tables are presented for the production cross sections of three gamma rays having energies of 96, 110, and 197 keV. (14 figures, 3 tables) (U.S.)

  20. Prediction of high-energy (> 0.3 MeV) substorm-related magnetospheric particles

    International Nuclear Information System (INIS)

    Baker, D.N.; Belian, R.D.; Higbie, P.R.; Hones, E.W. Jr.

    1979-01-01

    Measurements both at 6.6 R/sub E/ and in the plasma sheet (greater than or equal to 18 R/sub E/) show that high energy substorm-accelerated particles occur preferentially when the solar wind speed (V/sub sw/) is high. Virtually no > 0.3 MeV protons, for example, are observed in association with substorms that occur when V/sub sw/ is 700 km/sec. These results suggest that realtime monitoring of interplanetary conditions could allow simple, effective prediction of high energy magnetospheric particle disturbances. 7 references

  1. Energy measurement of prompt fission neutrons in 239Pu(n,f) for incident neutron energies from 1 to 200 MeV

    CERN Document Server

    Chatillon, A; Granier, Th; Laurent, B; Taïeb, J; Noda, S; Haight, R C; Devlin, M; Nelson, R O; O’Donnell, J M

    2010-01-01

    Prompt fission neutron spectra in the neutron-induced fission of 239Pu have been measured for incident neutron energies from 1 to 200 MeV at the Los Alamos Neutron Science Center. Preliminary results are discussed and compared to theoretical model calculation.

  2. A review on recent light particle correlation data from heavy ion collisions at intermediate and low energies

    International Nuclear Information System (INIS)

    Ardouin, D.

    1996-01-01

    A review of recent two-particle interferometry data for heavy-ion collisions in the domain of energy between ten and a few hundreds of MeV/nucleon is presented. Not only identical particles but unlike particle correlations have been used successfully as a probe for space-time dynamics of the collision process. Due to the availability of new dedicated charged particles or photon multi-detectors, the field of particle interferometry is moving to a good level of quantitative description: excitation energy and impact parameter dependences are now provided which should stimulate additional theoretical calculations for two-particle cross sections and emission of light fragments. (author)

  3. The energy partitioning of non-thermal particles in a plasma: the Coulomb logarithm revisited

    International Nuclear Information System (INIS)

    Singleton, Robert L Jr; Brown, Lowell S

    2008-01-01

    The charged particle stopping power in a highly ionized and weakly to moderately coupled plasma has been calculated exactly to leading and next-to-leading accuracy in the plasma density by Brown, Preston and Singleton (BPS). Since the calculational techniques of BPS might be unfamiliar to some, and since the same methodology can also be used for other energy transport phenomena, we will review the main ideas behind the calculation. BPS used their stopping power calculation to derive a Fokker-Planck equation, also accurate to leading and next-to-leading orders, and we will also review this. We use this Fokker-Planck equation to compute the electron-ion energy partitioning of a charged particle traversing a plasma. The motivation for this application is ignition for inertial confinement fusion-more energy delivered to the ions means a better chance of ignition, and conversely. It is therefore important to calculate the fractional energy loss to electrons and ions as accurately as possible. One method by which one calculates the electron-ion energy splitting of a charged particle traversing a plasma involves integrating the stopping power dE/dx. However, as the charged particle slows down and becomes thermalized into the background plasma, this method of calculating the electron-ion energy splitting breaks down. As a result, it suffers a systematic error that may be as large as T/E 0 , where T is the plasma temperature and E 0 is the initial energy of the charged particle. The formalism presented here is designed to account for the thermalization process and it provides results that are near-exact.

  4. Transverse energy per charged particle in heavy-ion collisions: Role of collective flow

    Science.gov (United States)

    Kumar Tiwari, Swatantra; Sahoo, Raghunath

    2018-03-01

    The ratio of (pseudo)rapidity density of transverse energy and the (pseudo)rapidity density of charged particles, which is a measure of the mean transverse energy per particle, is an important observable in high energy heavy-ion collisions. This ratio reveals information about the mechanism of particle production and the freeze-out criteria. Its collision energy and centrality dependence is almost similar to the chemical freeze-out temperature until top Relativistic Heavy-Ion Collider (RHIC) energy. The Large Hadron Collider (LHC) measurement at √{s_{NN}} = 2.76 TeV brings up new challenges towards understanding the phenomena like gluon saturation and role of collective flow, etc. being prevalent at high energies, which could contribute to the above observable. Statistical Hadron Gas Model (SHGM) with a static fireball approximation has been successful in describing both the centrality and energy dependence until top RHIC energies. However, the SHGM predictions for higher energies lie well below the LHC data. In order to understand this, we have incorporated collective flow in an excluded-volume SHGM (EV-SHGM). Our studies suggest that the collective flow plays an important role in describing E T/ N ch and it could be one of the possible parameters to explain the rise observed in E T/ N ch from RHIC to LHC energies. Predictions are made for E T/ N ch , participant pair normalized-transverse energy per unit rapidity and the Bjorken energy density for Pb+Pb collisions at √{s_{NN}} = 5.02 TeV at the Large Hadron Collider.

  5. Ab-initio Pulsar Magnetosphere: Particle Acceleration in Oblique Rotators and High-energy Emission Modeling

    Science.gov (United States)

    Philippov, Alexander A.; Spitkovsky, Anatoly

    2018-03-01

    We perform global particle-in-cell simulations of pulsar magnetospheres, including pair production, ion extraction from the surface, frame-dragging corrections, and high-energy photon emission and propagation. In the case of oblique rotators, the effects of general relativity increase the fraction of the open field lines that support active pair discharge. We find that the plasma density and particle energy flux in the pulsar wind are highly non-uniform with latitude. A significant fraction of the outgoing particle energy flux is carried by energetic ions, which are extracted from the stellar surface. Their energies may extend up to a large fraction of the open field line voltage, making them interesting candidates for ultra-high-energy cosmic rays. We show that pulsar gamma-ray radiation is dominated by synchrotron emission, produced by particles that are energized by relativistic magnetic reconnection close to the Y-point and in the equatorial current sheet. In most cases, the calculated light curves contain two strong peaks, which is in general agreement with Fermi observations. The radiative efficiency decreases with increasing pulsar inclination and increasing efficiency of pair production in the current sheet, which explains the observed scatter in L γ versus \\dot{E}. We find that the high-frequency cutoff in the spectra is regulated by the pair-loading of the current sheet. Our findings lay the foundation for quantitative interpretation of Fermi observations of gamma-ray pulsars.

  6. Application of the non-extensive statistical approach to high energy particle collisions

    Science.gov (United States)

    Bíró, Gábor; Barnaföldi, Gergely Gábor; Biró, Tamás Sándor; Ürmössy, Károly

    2017-06-01

    In high-energy collisions the number of created particles is far less than the thermodynamic limit, especially in small colliding systems (e.g. proton-proton). Therefore final-state effects and fluctuations in the one-particle energy distribution are appreciable. As a consequence the characterization of identified hadron spectra with the Boltzmann - Gibbs thermodynamical approach is insuffcient [1]. Instead particle spectra measured in high-energy collisions can be described very well with Tsallis -Pareto distributions, derived from non-extensive thermodynamics [2, 3]. Using the Tsallis q-entropy formula, a generalization of the Boltzmann - Gibbs entropy, we interpret the microscopic physics by analysing the Tsallis q and T parameters. In this paper we give a quick overview on these parameters, analyzing identified hadron spectra from recent years in a wide center-of-mass energy range. We demonstrate that the fitted Tsallis-parameters show dependency on the center-of-mass energy and particle species. Our findings are described well by a QCD inspired evolution ansatz. Based on this comprehensive study, apart from the evolution, both mesonic and barionic components found to be non-extensive (q > 1), beside the mass ordered hierarchy observed in parameter T.

  7. Spin rotation and depolarization of high-energy particles in crystals at Hadron Collider (LHC) and Future Circular Collider (FCC) energies and the possibility to measure the anomalous magnetic moments of short-lived particles

    CERN Document Server

    Baryshevsky, V.G.

    2015-01-01

    We study the phenomena of spin rotation and depolarization of high-energy particles in crystals in the range of high energies that will be available at Hadron Collider (LHC) and Future Circular Collider (FCC). It is shown that these phenomena can be used to measure the anomalous magnetic moments of short-lived particles in this range of energies. We also demonstrate that the phenomenon of particle spin depolarization in crystals provides a unique possibility of measuring the anomalous magnetic moment of negatively-charged particles (e.g., beauty baryons), for which the channeling effect is hampered due to far more rapid dechanneling as compared to that for positively-charged particles. Channeling of particles in either straight or bent crystals with polarized nuclei could be used for polarization and the analysis thereof of high-energy particles.

  8. Free-Free Transitions in the Presence of Laser Fields and Debye Potential at Very Low Incident Electron Energies

    Science.gov (United States)

    Bhatia, Anand

    2012-01-01

    We study the free-free transition in electron-helium ion in the ground state and embedded in a Debye potential in the presence of an external laser field at very low incident electron energies. The laser field is treated classically while the collision dynamics is treated quantum mechanically. The laser field is chosen as monochromatic, linearly polarized and homogeneous. The incident electron is considered to be dressed by the laser field in a nonperturbative manner by choosing Volkov wave function for it. The scattering wave function for the incident electron on the target embedded in a Debye potential is solved numerically by taking into account the effect of electron exchange. We calculate the laser-assisted differential and total cross sections for free-free transition for absorption/emission of a single photon or no photon exchange. The results will be presented at the conference.

  9. Energy response of detectors to alpha/beta particles and compatibility of the equivalent factors

    International Nuclear Information System (INIS)

    Lin Bingxing; Li Guangxian; Lin Lixiong

    2011-01-01

    By measuring detect efficiency and equivalent factors of alpha/beta radiation with different energies on three types of detectors, this paper compares compatibility of their equivalent factors and discusses applicability of detectors to measuring total alpha/beta radiation. The result shows the relationship between efficiency of alpha/beta radiation and their energies on 3 types of detectors, such as scintillation and proportional and semiconductor counters, are overall identical. Alpha count efficiency display exponential relation with alpha-particle energy. While beta count efficiency display logarithm relation with beta-particle energy, but the curves appears deflection at low energy. Comparison test of energy response also shows that alpha and beta equivalent factors of scintillation and proportional counters have a good compatibility, and alpha equivalent factors of the semiconductor counters are in good agreement with those of the above two types of counters, but beta equivalent factors have obvious difference, or equivalent factors of low energy beta-particle are lower than those of other detectors. So, the semiconductor counter can not be used for measuring total radioactivity or for the measurements for the purpose of food safety. (authors)

  10. Treatment of Electronic Energy Level Transition and Ionization Following the Particle-Based Chemistry Model

    Science.gov (United States)

    Liechty, Derek S.; Lewis, Mark

    2010-01-01

    A new method of treating electronic energy level transitions as well as linking ionization to electronic energy levels is proposed following the particle-based chemistry model of Bird. Although the use of electronic energy levels and ionization reactions in DSMC are not new ideas, the current method of selecting what level to transition to, how to reproduce transition rates, and the linking of the electronic energy levels to ionization are, to the author s knowledge, novel concepts. The resulting equilibrium temperatures are shown to remain constant, and the electronic energy level distributions are shown to reproduce the Boltzmann distribution. The electronic energy level transition rates and ionization rates due to electron impacts are shown to reproduce theoretical and measured rates. The rates due to heavy particle impacts, while not as favorable as the electron impact rates, compare favorably to values from the literature. Thus, these new extensions to the particle-based chemistry model of Bird provide an accurate method for predicting electronic energy level transition and ionization rates in gases.

  11. Pathway and conversion of energy incident on auroral and sub-auroral ionosphere at substorm expansion onset

    Science.gov (United States)

    Ebihara, Y.; Tanaka, T.

    2017-12-01

    One explanation for SAPS/SAID is the poleward ionospheric electric field arising from a pair of Region 1 and Region 2 field-aligned currents (FACs). At substorm expansion onset, the FACs are intensified, resulting in intensification of energy incident on the auroral and sub-auroral ionosphere. Where does the energy comes from? Based on the results obtained by the global magnetohydrodynamics (MHD) simulation, we present energy flow and energy conversion associated with the Region 1 and Region 2 FACs that are intensified at the onset of substorm expansion. The cusp/mantle region transmits electromagnetic energy to almost the entire region of the magnetosphere. A part of electromagnetic energy is stored in the lobe in the growth phase. When reconnection takes place in the near-Earth tail region, the stored energy is released in addition to the continuously supplied one from the cusp/mantle dynamo. Two types of pathways of energy seem to be involved in the generation of the near-Earth dynamo that is associated with FACs at the expansion onset. The first type is related to the earthward fast flow in the plasma sheet. The electromagnetic energy coming from the lobe splits into the thermal energy and the kinetic energy. The kinetic energy is then converted to the thermal energy and the electromagnetic energy, in association of flow braking. The second type is that the plasma coming from the lobe goes into the inner magnetosphere directly. The electromagnetic energy is converted to the thermal energy, followed by the electromagnetic energy at off-equator. The near-Earth dynamo region seems to be embedded in the magnetospheric convection system. In this sense, the expansion onset may be regarded as a sudden, local intensification of the convection.

  12. Two-particle one-hole multiple-scattering contribution to 17O energies using an energy-dependent reaction matrix

    International Nuclear Information System (INIS)

    Bando, H.; Krenciglowa, E.M.

    1976-01-01

    The role of 2p1h correlations in 17 O is studied within a multiple-scattering formalism. An accurate, energy-dependent reaction matrix with orthogonalized plane-wave intermediate states is used to assess the relative importance of particle-particle and particle-hole correlations in the 17 O energies. The effect of energy dependence of the reaction matrix is closely examined. (Auth.)

  13. Cryogenics for high-energy particle accelerators: highlights from the first fifty years

    CERN Document Server

    AUTHOR|(CDS)2067931

    2017-01-01

    Applied superconductivity has become a key technology for high-energy particle accelerators, allowing to reach higher beam energy while containing size, capital expenditure and operating costs. Large and powerful cryogenic systems are therefore ancillary to low-temperature superconducting accelerator devices – magnets and high-frequency cavities – distributed over multi-kilometre distances and operating generally close to the normal boiling point of helium, but also above 4.2 K in supercritical and down to below 2 K in superfluid. Additionally, low-temperature operation in accelerators may also be required by considerations of ultra-high vacuum, limited stored energy and beam stability. We discuss the rationale for cryogenics in high-energy particle accelerators, review its development over the past half-century and present its outlook in future large projects, with reference to the main engineering domains of cryostat design and heat loads, cooling schemes, efficient power refrigeration and cryogenic flu...

  14. Enhancement of low energy particle flux around plasmapause under quiet geomagnetic condition

    Science.gov (United States)

    Lee, J.

    2016-12-01

    Plasmapause is the boundary of the plasmaspheric region where cold plasma is dominant. In this boundary, the plasma density shows depletion to 1 10 on direction from the plasmasphere to magnetosphere and changes composition of energy distribution of particle. Some previous study provides that the location of the plasmapause expand beyond geosynchronous orbit under the quiet geomagnetic conditions. In this work, we study the changed characteristic of particle flux around the plasmapause using measurement from Van Allen Probes. On 23 April 2013, the satellites observed simultaneously proton and electron fluxes enhancement with E > 100 eV. During 12 hours prior to this event, the geomagnetic conditions were very quiet, Kp < 1, and geomagnetic storm did not occur. This event maintain for 15 minutes and only proton flux decrease rapidly in the magnetosphere. In this period SYM-H index enhanced abruptly in response to the impact of the dynamic pressure enhancement and AE index increased gradually up to about 200 nT. Electric field started to perturb in coincidence with enhancement of particle flux from the plasmapause. To explain the variation of low energy particle flux we will compare kinetic property of low energy particle by using velocity space distribution function at region of inner and outer boundary of the plasmapause.

  15. Comparative study of Monte Carlo particle transport code PHITS and nuclear data processing code NJOY for PKA energy spectra and heating number under neutron irradiation

    International Nuclear Information System (INIS)

    Iwamoto, Y.; Ogawa, T.

    2016-01-01

    The modelling of the damage in materials irradiated by neutrons is needed for understanding the mechanism of radiation damage in fission and fusion reactor facilities. The molecular dynamics simulations of damage cascades with full atomic interactions require information about the energy distribution of the Primary Knock on Atoms (PKAs). The most common process to calculate PKA energy spectra under low-energy neutron irradiation is to use the nuclear data processing code NJOY2012. It calculates group-to-group recoil cross section matrices using nuclear data libraries in ENDF data format, which is energy and angular recoil distributions for many reactions. After the NJOY2012 process, SPKA6C is employed to produce PKA energy spectra combining recoil cross section matrices with an incident neutron energy spectrum. However, intercomparison with different processes and nuclear data libraries has not been studied yet. Especially, the higher energy (~5 MeV) of the incident neutrons, compared to fission, leads to many reaction channels, which produces a complex distribution of PKAs in energy and type. Recently, we have developed the event generator mode (EGM) in the Particle and Heavy Ion Transport code System PHITS for neutron incident reactions in the energy region below 20 MeV. The main feature of EGM is to produce PKA with keeping energy and momentum conservation in a reaction. It is used for event-by-event analysis in application fields such as soft error analysis in semiconductors, micro dosimetry in human body, and estimation of Displacement per Atoms (DPA) value in metals and so on. The purpose of this work is to specify differences of PKA spectra and heating number related with kerma between different calculation method using PHITS-EGM and NJOY2012+SPKA6C with different libraries TENDL-2015, ENDF/B-VII.1 and JENDL-4.0 for fusion relevant materials

  16. The influence of mineral dust particles on the energy output of photovoltaic cells

    Science.gov (United States)

    Roesch, C.; Eltahir, E. A. B.; Al-awwad, Z.; Alqatari, S.; Cziczo, D. J.; Roesch, M.

    2016-12-01

    The city of Al Khafji in Saudi Arabia plans to provide a regular supply of desalinated water from the Persian Gulf while simultaneously cutting back on the usage of fossil fuels. The power for the high energy-consuming reverse osmosis (RO) process will be derived from photovoltaic (PV) cells as a cleaner and resource-conserving means of energy production. Numerous sun hours (yearly 3000) makes the Persian Gulf region's geographical location appropriate for applying PV techniques at this scale. A major concern for PV power generation is mineral dust from desert regions accumulating on surfaces and thereby reducing the energy output. This study aims to show the impact of dust particles on the PV energy reduction by examining dust samples from various Persian Gulf regions. Bulk samples were collected at the surface. The experimental setup involved a sealed container with a solar panel unit (SPU), including an adjustable mounting plate, solar cells (amorphous and monocrystalline), and a pyranometer (SMP3, Kipp & Zonen Inc.). A Tungsten Halogen lamp was used as the light source. Dust particles were aerosolized with a shaker (Multi-Wrist shaker, Lab line). Different techniques were applied to characterize each sample: the particle size distributions were measured using an Optical Particle Sizer (OPS, TSI Inc.), the chemical composition was analyzed using the Particle Analysis by Mass Spectrometry (PALMS) instrument, and Transmission Electron Microscope Energy-Dispersive X-ray spectroscopy (TEM-EDX) was used to define morphology, size and structure. Preliminary results show that the energy output is affected by aerosol morphology (monodisperse, polydisperse), composition and solar cell type.

  17. Energy losses (gains) of massive coloured particles in stochastic colour medium

    International Nuclear Information System (INIS)

    Leonidov, A.; Rossijskaya Akademiya Nauk, Moscow

    1995-01-01

    The propagation of massive coloured particles in stochastic background chromoelectric field is studied using the semiclassical equations of motion. Depending on the nature of the stochastic background we obtain the formulae for the energy losses of heavy coloured projectile in nonperturbative hadronic medium and for the energy gains in the stochastic field present, e.g., in the turbulent plasma. The result appears to be significantly dependent on the form of the correlation function of stochastic external field. (orig.)

  18. HIGH-ENERGY PARTICLES FLUX ORIGIN IN THE CLOUDS, DARK LIGHTNING

    Directory of Open Access Journals (Sweden)

    Kuznetsov, V.V.

    2016-11-01

    Full Text Available Problem of high-energy particles flux origin in clouds is discussed. Conditions in which dark lightning preceding the ordinary one and creating additional ionization, fluxes of fast electrons with MeV energy prior to the earthquake detected among lightning initiating ball-lightning, glow, sprites are considered. All above phenomena appear to be of general nature founded on quantum entanglement of hydrogen bonds protons in water clasters inside clouds.

  19. DYNECHARM++: a toolkit to simulate coherent interactions of high-energy charged particles in complex structures

    Science.gov (United States)

    Bagli, Enrico; Guidi, Vincenzo

    2013-08-01

    A toolkit for the simulation of coherent interactions between high-energy charged particles and complex crystal structures, called DYNECHARM++ has been developed. The code has been written in C++ language taking advantage of this object-oriented programing method. The code is capable to evaluating the electrical characteristics of complex atomic structures and to simulate and track the particle trajectory within them. Calculation method of electrical characteristics based on their expansion in Fourier series has been adopted. Two different approaches to simulate the interaction have been adopted, relying on the full integration of particle trajectories under the continuum potential approximation and on the definition of cross-sections of coherent processes. Finally, the code has proved to reproduce experimental results and to simulate interaction of charged particles with complex structures.

  20. Analytic theory of the energy and time independent particle transport in the plane geometry

    International Nuclear Information System (INIS)

    Simovic, R.D.

    2001-01-01

    An analytic investigation of the energy and time independent particle transport in the plane geometry described by a common anisotropic scattering function is carried out. Regarding the particles with specific diffusion histories in the infinite or the semi-infinite medium, new exact solutions of the corresponding transport equations are analytically derived by means of the Fourier inversion technique. Two particular groups of particles scattered after each successive collision into the directions μ 0, were considered. Its Fourier transformed transport equations have solutions without logarithmic singular points, in the upper part or the lower part of the complex k-plane. The Fourier inversion of solutions are carried out analytically and the obtained formulae represents valid generalization of the expressions for the flux of once scattered particles. (author)

  1. Study of a charge-coupled device for high-energy-particle detection

    International Nuclear Information System (INIS)

    Bhuiya, A.H.

    1983-05-01

    This presentation is based on measurements made to evaluate the application of charge-coupled devices as detectors of high-energy particles. The experiment was performed with a Fairchild Linear 256-Cell CCD111 array (size 8μm x 17 μm/cell), utilizing a light source instead of a particle beam. It was observed that the minimum detectable signal was limited to approx. 488 electrons at -50 0 C, where the readout and exposure times were about 260 ms and 400 ms respectively. The transfer inefficiency of the CCD111 was determined to be approx. 10 -4 . It has been concluded that at a lower temperature (approx. -100 0 C) or with faster readout (approx. 10 ms), the CCD111 would be able to detect the total deposited energy of minimum-ionizing charged particles

  2. The low energy frontier: searches for ultra-light particles beyond the Standard Model

    CERN Multimedia

    CERN. Geneva

    2012-01-01

    In the recent years theoretical studies and astrophysical observations have confirmed that unknown constituents of our universe like dark matter may find its explanation not only at large-scale experiments at highest energies, but could also show up at the opposite energy scale. In many laboratories world-wide searches for axions, axion-like particles, hidden photons, chameleons or other so-called WISPs with masses below the eV scale are ongoing. Examples at DESY are the experiments ALPS ("Any Light Particle Search") and SHIPS ("Solar HIdden Photon Search"). At CERN CAST and OSQAR take data. In all these experiments new particles could manifest themselves in a very spectacular manner. Light would apparently shine through thickest walls. The results of a first generation of laboratory and astrophysics experiments will be summarized and plans for future enterprises be discussed

  3. Particle and energy balance in the SOL generated by a limiter in a RFP plasma

    International Nuclear Information System (INIS)

    Antoni, V.; Bagatin, M.; Desideri, D.; Serianni, G.

    1992-01-01

    The plasma outer region of the RFP experiment ETA BETA II has been extensively investigated. In particular by an insertable graphite limiter, instrumented with thermocouples and Langmuir probes, the energy and particle fluxes in the shadow of the limiter have been measured at different insertions. The results are compared with those obtained by small-sized calorimeter/Langmuir probes inserted to investigate, with fine space resolution, the outer region without limiter. Almost 80% of the power to the limiter is estimated to be carried by fast suprathermal electrons flowing along the magnetic field line direction. From an energy balance equation, applied in the SOL locally generated, the connection length of the limiter has been derived. Thus a particle balance has been applied to determine the particle diffusion coefficient at the plasma edge. (orig.)

  4. Emission of high-energy charged particles at 00 in Ne-induced reactions

    International Nuclear Information System (INIS)

    Borcea, C.; Gierlik, E.; Kalinin, A.M.; Kalpakchieva, R.; Oganessia, Yu.Ts.; Pawlat, T.; Penionzhkevich, Yu.E.; Ryakhlyuk, A.V.

    1982-01-01

    Inclusive energy spectra have been measured for light charged particles emitted in the bombardment of 232 Th, 181 Ta, sup(nat)Ti and 12 C targets by 22 Ne ions at 178 MeV and sup(nat)Ti target by 20 Ne ions at 196 MeV. The reaction products were analysed and detected by means of a ΔE-E telescope placed in the focal plane of a magnetic spectrometer located at an angle of 0 deg with respect to the beam direction. In all the reactions studied light charged particles with an energy close to the respective calculated kinematic limit for a two-body exit channel are produced with relatively great probability. The results obtained make it possible to draw some conclusions about the reaction mechanism involving the emission of light charged particles

  5. EVOLUTION OF HIGH-ENERGY PARTICLE DISTRIBUTION IN MATURE SHELL-TYPE SUPERNOVA REMNANTS

    Energy Technology Data Exchange (ETDEWEB)

    Zeng, Houdun; Xin, Yuliang; Liu, Siming; Zhang, Shuinai [Key Laboratory of Dark Matter and Space Astronomy, Purple Mountain Observatory, Chinese Academy of Sciences, Nanjing 210008 (China); Jokipii, J. R. [University of Arizona, Tucson, Arizona, 85721 (United States); Zhang, Li, E-mail: zhd@pmo.ac.cn, E-mail: liusm@pmo.ac.cn [Key Laboratory of Astroparticle Physics of Yunnan Province, Kunming, 650091 (China)

    2017-01-10

    Multi-wavelength observations of mature supernova remnants (SNRs), especially with recent advances in γ -ray astronomy, make it possible to constrain energy distribution of energetic particles within these remnants. In consideration of the SNR origin of Galactic cosmic rays and physics related to particle acceleration and radiative processes, we use a simple one-zone model to fit the nonthermal emission spectra of three shell-type SNRs located within 2° on the sky: RX J1713.7−3946, CTB 37B, and CTB 37A. Although radio images of these three sources all show a shell (or half-shell) structure, their radio, X-ray, and γ -ray spectra are quite different, offering an ideal case to explore evolution of energetic particle distribution in SNRs. Our spectral fitting shows that (1) the particle distribution becomes harder with aging of these SNRs, implying a continuous acceleration process, and the particle distributions of CTB 37A and CTB 37B in the GeV range are harder than the hardest distribution that can be produced at a shock via the linear diffusive shock particle acceleration process, so spatial transport may play a role; (2) the energy loss timescale of electrons at the high-energy cutoff due to synchrotron radiation appears to be always a bit (within a factor of a few) shorter than the age of the corresponding remnant, which also requires continuous particle acceleration; (3) double power-law distributions are needed to fit the spectra of CTB 37B and CTB 37A, which may be attributed to shock interaction with molecular clouds.

  6. Critical rate of energy loss for registration of charged particles in cellulose nitrate

    International Nuclear Information System (INIS)

    Knoefel, T.M.J.; Sachett, I.A.

    1979-09-01

    Cellulose nitrate films LR-115 type II (Kodak-Pathe) have been exposed, at right angles, to alpha-particle beams in the energy range 2.5 - 5.5 MeV. From measurements of both through etched track density, a critical rate of energy lo ss for track registration of (0.85 +- 0.05) MeV cm 2 /mg has been derived, which corresponds to a critical alpha-particle energy of (4.6 +- 0.4) MeV. These results are compatible with those obtained by other authors whenever similar etching conditions are used. The concepts of threshold rate of energy loss and a threshold energy for etched-track formation are introduced, and their values are obtained from the experiment as being (0.80 +- 0.05) MeV cm 2 /mg and (5.1 +- 0.4) Mev, respectively. In addition, the present work provides a suitable set of useful, reference data for further applications of such plastic nuclear track detector in problems concerned with the detection of low-energy alpha particles. (Author) [pt

  7. Measurement of {alpha} particle energy loss in biological tissue below 2 MeV

    Energy Technology Data Exchange (ETDEWEB)

    Stella, S. [Department of Nuclear and Theoretical Physics, University of Pavia, Pavia (Italy); National Institute of Nuclear Physics (INFN), Pavia (Italy); Bortolussi, S. [Department of Nuclear and Theoretical Physics, University of Pavia, Pavia (Italy); National Institute of Nuclear Physics (INFN), Pavia (Italy)], E-mail: silva.bortolussi@pv.infn.it; Bruschi, P.; Portella, C. [Department of Nuclear and Theoretical Physics, University of Pavia, Pavia (Italy); Altieri, S. [Department of Nuclear and Theoretical Physics, University of Pavia, Pavia (Italy); National Institute of Nuclear Physics (INFN), Pavia (Italy)

    2009-09-01

    The energy loss of {alpha} particles crossing biological tissue at energies between 0.8 and 2.2 MeV has been measured. This energy range is very important for boron neutron capture therapy, based on the {sup 10}B(n,{alpha}){sup 7}Li reaction, which emits {alpha} particles with energies of 1.78 and 1.47 MeV. One of the methods used for the measurement of the boron concentration in tissue is based on the deconvolution of the {alpha} spectra obtained from neutron irradiation of thin (70 {mu}m) tissue samples. For this technique, a knowledge of the behaviour of the energy loss of the particles in the irradiated tissue is of critical importance. In particular, the curve of the residual energy as a function of the distance travelled in the tissue must be known. In this paper, the results of an experiment carried out with an {sup 241}Am source and a series of cryostatic sections of rat-lung tissue are presented. The experimental measurements are compared with the results of Monte Carlo calculations performed with the MCNPX code.

  8. Extension of geometrical-optics approximation to on-axis Gaussian beam scattering. II. By a spheroidal particle with end-on incidence.

    Science.gov (United States)

    Xu, Feng; Ren, Kuan Fang; Cai, Xiaoshu; Shen, Jianqi

    2006-07-10

    On the basis of our previous work on the extension of the geometrical-optics approximation to Gaussian beam scattering by a spherical particle, we present a further extension of the method to the scattering of a transparent or absorbing spheroidal particle with the same symmetric axis as the incident beam. As was done for the spherical particle, the phase shifts of the emerging rays due to focal lines, optical path, and total reflection are carefully considered. The angular position of the geometric rainbow of primary order is theoretically predicted. Compared with our results, the Möbius prediction of the rainbow angle has a discrepancy of less than 0.5 degrees for a spheroidal droplet of aspect radio kappa within 0.95 and 1.05 and less than 2 degrees for kappa within 0.89 and 1.11. The flux ratio index F, which qualitatively indicates the effect of a surface wave, is also studied and found to be dependent on the size, refractive index, and surface curvature of the particle.

  9. Approximate energy correction for particle number summetry breaking in constrained Hartree-Fock plus BCS calculations

    International Nuclear Information System (INIS)

    Redon, N.; Meyer, J.; Meyer, M.

    1989-01-01

    An approximate restoration of the particle number symmetry, a la Lipkin-Nogami, is numerically investigated in the context of Constrained Hartree-Fock plus BCS calculations. Its effect is assessed in a variety of physical situations like potential energy landscapes in transitional nuclei, shape isomerism at low spin and fission barriers of actinide nuclei

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

    Energy Technology Data Exchange (ETDEWEB)

    Makarov, D. N., E-mail: makarovd0608@yandex.ru; Matveev, V. I. [Lomonosov Northern (Arctic) Federal University (Russian Federation)

    2015-05-15

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

  11. Overview of lunar detection of ultra-high energy particles and new plans for the SKA

    NARCIS (Netherlands)

    James, Clancy W.; Alvarez-Muñiz, Jaime; Bray, Justin D.; Buitink, Stijn; Dagkesamanskii, Rustam D.; Ekers, Ronald D.; Falcke, Heino; Gayley, Ken; Huege, Tim; Mevius, Maaijke; Mutel, Rob; Scholten, Olaf; Spencer, Ralph; ter Veen, Sander; Winchen, Tobias

    2017-01-01

    The lunar technique is a method for maximising the collection area for ultra-high-energy (UHE) cosmic ray and neutrino searches. The method uses either ground-based radio telescopes or lunar orbiters to search for Askaryan emission from particles cascading near the lunar surface. While experiments

  12. Particle and energy transport studies on TFTR and implications for helium ash in future fusion devices

    International Nuclear Information System (INIS)

    Synakowski, E.J.; Efthimion, P.C.; Rewoldt, G.; Stratton, B.C.; Tang, W.M.; Bell, R.E.; Grek, B.; Hulse, R.A.; Johnson, D.W.; Hill, K.W.; Mansfield, D.K.; McCune, D.; Mikkelsen, D.R.; Park, H.K.; Ramsey, A.T.; Scott, S.D.; Taylor, G.; Timberlake, J.; Zarnstorff, M.C.

    1992-01-01

    Particle and energy transport in tokamak plasmas have long been subjects of vigorous investigation. Present-day measurement techniques permit radially resolved studies of the transport of electron perturbations, low- and high-Z impurities, and energy. In addition, developments in transport theory provide tools that can be brought to bear on transport issues. Here, we examine local particle transport measurements of electrons, fully-stripped thermal helium, and helium-like iron in balanced-injection L-mode and enhanced confinement deuterium plasmas on TFTR of the same plasma current, toroidal field, and auxiliary heating power. He 2+ and Fe 24+ transport has been studied with charge exchange recombination spectroscopy, while electron transport has been studied by analyzing the perturbed electron flux following the same helium puff used for the He 2+ studies. By examining the electron and He 2+ responses following the same gas puff in the same plasmas, an unambiguous comparison of the transport of the two species has been made. The local energy transport has been examined with power balance analysis, allowing for comparisons to the local thermal fluxes. Some particle and energy transport results from the Supershot have been compared to a transport model based on a quasilinear picture of electrostatic toroidal drift-type microinstabilities. Finally, implications for future fusion reactors of the observed correlation between thermal transport and helium particle transport is discussed

  13. Measurement methods for high energy particle identification in gaseous mixture detectors

    International Nuclear Information System (INIS)

    Marchand, Patrick.

    1981-01-01

    In this work, we discuss some methods for high energy particle identification. We study and design a MWPC equipped with a preamplifier gap for increased resolution. In addition, we propose a new mehod of counting primary collisions. The electronic system used for multiplexing analog wire signals is also described [fr

  14. Study on the forward-feed neural network used for the classification of high energy particles

    International Nuclear Information System (INIS)

    Luo Guangxuan; Dai Guiliang

    1997-01-01

    Neural network has been applied in the field of high energy physics experiment for the classification of particles and gained good results. The author emphasizes the systematic analysis of the fundamental principle of the forward-feed neural network and discusses the problems and solving methods in application

  15. Some interesting features of charged particles produced in high-energy hadron-emulsion collisions

    International Nuclear Information System (INIS)

    Khushnood, H.; Ansari, A.R.

    1990-01-01

    The emission characteristics of secondary charged particles produced in 400 GeV proton-emulsion interactions were compared with those obtained at other energies. The results revealed that the angular distribution of grey particles does not depend on the nature and energy of the projectile. The dependence of the average multiplicity of the grey, black, shower, and heavily ionizing tracks on the mass of the target nucleus (A) and the nature and energy of the projectiles are also examined. The ratio of the valance quarks in pions (π - ) and protons (p) was found to be almost equal to the ratio of the grey particles produced in π - -A and p-A collisions at the same energy. The values of the normalized moments of the multiplicity distributions of charged shower particles in different N h intervals were found to nearly the same. However, this value increased with increasing values of the moment index, K. Finally, the values of the normalized and central moments were almost equal for both p-p and p-A interactions

  16. Bulk GaN alpha-particle detector with large depletion region and improved energy resolution

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Qiang; Mulligan, Padhraic [Nuclear Engineering Program, Department of Mechanical and Aerospace Engineering, The Ohio State University, Columbus, OH 43210 (United States); Wang, Jinghui [Department of Radiology, Stanford University, 1201 Welch Rd, Stanford, CA 94305 (United States); Chuirazzi, William [Nuclear Engineering Program, Department of Mechanical and Aerospace Engineering, The Ohio State University, Columbus, OH 43210 (United States); Cao, Lei, E-mail: cao.152@osu.edu [Nuclear Engineering Program, Department of Mechanical and Aerospace Engineering, The Ohio State University, Columbus, OH 43210 (United States)

    2017-03-21

    An alpha-particle detector was fabricated using a freestanding n-type bulk GaN wafer with a Au/Ni/GaN sandwich Schottky structure. Current–voltage measurements at room temperature revealed a Schottky contact with a leakage current of 7.53±0.3 nA at a reverse bias of 200 V. The detector had a large depletion depth that can capture much of the energy from 5.486 MeV alpha particles emitted from a {sup 241}Am source. The resolution of its alpha-particle energy spectrum was improved to 2.2±0.2% at 5.486 MeV under a bias of 550 V. This superior resolution was attributed to the shortening of the carrier transit time and the large energy deposition within the large depletion depth, i.e., 27 µm at −550 V, which all resulted in a more complete charge collection. A model developed using the ATLAS simulation framework from Silvaco Inc. was employed to study the charge collection process. The simulation results were found to agree closely with the experimental results. This detector will be beneficial for research at neutron scattering facilities, the International Thermonuclear Experimental Reactor, and the Large Hadron Collider, among other institutions, where the Si-based charged particle detectors could be quickly degraded in an intense radiation field. - Highlights: • An alpha-particle detector based on a Schottky-structured GaN wafer was tested. • The detector's large depletion depth enables fuller energy spectra to be obtained. • The best resolution yet attained in GaN alpha-particle spectrometry was achieved. • The detector's short carrier transit time resulted in improved charge collection. • This detector is usable in extreme conditions, including intense radiation fields.

  17. Inducing Strong Density Modulation with Small Energy Dispersion in Particle Beams and the Harmonic Amplifier Free Electron Laser

    CERN Document Server

    McNeil, Brian W J; Robb, Gordon

    2005-01-01

    We present a possible method of inducing a periodic density modulation in a particle beam with little increase in the energy dispersion of the particles. The flow of particles in phase space does not obey Liouville's Theorem. The method relies upon the Kuramoto-like model of collective synchronism found in free electron generators of radiation, such as Cyclotron Resonance Masers and the Free Electron Laser. For the case of an FEL interaction, electrons initially begin to bunch and emit radiation energy with a correlated energy dispersion which is periodic with the FEL ponderomotive potential. The relative phase between potential and particles is then changed by approximately 180 degrees. The particles continue to bunch, however, there is now a correlated re-absorption of energy from the field. We show that, by repeating this relative phase change many times, a significant density modulation of the particles may be achieved with only relatively small energy dispersion. A similar method of repeated relative ele...

  18. Incident energy and target dependence of interaction cross sections and density distribution of neutron drip-line nuclei

    International Nuclear Information System (INIS)

    Shimoura, S.

    1992-01-01

    The relation between nuclear density distribution and interaction cross section is discussed in terms of Glauber model. Based on the model, density distribution of neutron drip-line nucleus 11 Be and 11 Li is determined experimentally from incident energy dependence of interaction cross sections of 11 Be and 11 Li on light targets. The obtained distributions have long tails corresponding to neutron halos of loosely bound neutrons. (Author)

  19. Energy-Aware Real-Time Task Scheduling for Heterogeneous Multiprocessors with Particle Swarm Optimization Algorithm

    Directory of Open Access Journals (Sweden)

    Weizhe Zhang

    2014-01-01

    Full Text Available Energy consumption in computer systems has become a more and more important issue. High energy consumption has already damaged the environment to some extent, especially in heterogeneous multiprocessors. In this paper, we first formulate and describe the energy-aware real-time task scheduling problem in heterogeneous multiprocessors. Then we propose a particle swarm optimization (PSO based algorithm, which can successfully reduce the energy cost and the time for searching feasible solutions. Experimental results show that the PSO-based energy-aware metaheuristic uses 40%–50% less energy than the GA-based and SFLA-based algorithms and spends 10% less time than the SFLA-based algorithm in finding the solutions. Besides, it can also find 19% more feasible solutions than the SFLA-based algorithm.

  20. Monte Carlo charged-particle tracking and energy deposition on a Lagrangian mesh.

    Science.gov (United States)

    Yuan, J; Moses, G A; McKenty, P W

    2005-10-01

    A Monte Carlo algorithm for alpha particle tracking and energy deposition on a cylindrical computational mesh in a Lagrangian hydrodynamics code used for inertial confinement fusion (ICF) simulations is presented. The straight line approximation is used to follow propagation of "Monte Carlo particles" which represent collections of alpha particles generated from thermonuclear deuterium-tritium (DT) reactions. Energy deposition in the plasma is modeled by the continuous slowing down approximation. The scheme addresses various aspects arising in the coupling of Monte Carlo tracking with Lagrangian hydrodynamics; such as non-orthogonal severely distorted mesh cells, particle relocation on the moving mesh and particle relocation after rezoning. A comparison with the flux-limited multi-group diffusion transport method is presented for a polar direct drive target design for the National Ignition Facility. Simulations show the Monte Carlo transport method predicts about earlier ignition than predicted by the diffusion method, and generates higher hot spot temperature. Nearly linear speed-up is achieved for multi-processor parallel simulations.

  1. Why is solar cycle 24 an inefficient producer of high-energy particle events?

    Science.gov (United States)

    Vainio, Rami; Raukunen, Osku; Tylka, Allan J.; Dietrich, William F.; Afanasiev, Alexandr

    2017-08-01

    Aims: The aim of the study is to investigate the reason for the low productivity of high-energy SEPs in the present solar cycle. Methods: We employ scaling laws derived from diffusive shock acceleration theory and simulation studies including proton-generated upstream Alfvén waves to find out how the changes observed in the long-term average properties of the erupting and ambient coronal and/or solar wind plasma would affect the ability of shocks to accelerate particles to the highest energies. Results: Provided that self-generated turbulence dominates particle transport around coronal shocks, it is found that the most crucial factors controlling the diffusive shock acceleration process are the number density of seed particles and the plasma density of the ambient medium. Assuming that suprathermal populations provide a fraction of the particles injected to shock acceleration in the corona, we show that the lack of most energetic particle events as well as the lack of low charge-to-mass ratio ion species in the present cycle can be understood as a result of the reduction of average coronal plasma and suprathermal densities in the present cycle over the previous one.

  2. Low-energy particle interaction at carbon nanowalls on W surface

    Energy Technology Data Exchange (ETDEWEB)

    Tanaka, N., E-mail: nozomi.tanaka@ppl2.qse.tohoku.ac.j [Tohoku University, Aramaki 6-01-2, Aoba, Sendai 980-8579 (Japan); Yamaoka, H. [Harima Institute, RIKEN (The Institute of Physical and Chemical Research), Hyogo 679-5148 (Japan); Nishiura, M.; Tsumori, K. [National Institute for Fusion Science, Toki, Gifu 509-5292 (Japan); Nagamura, T.; Sasao, M. [Tohoku University, Aramaki 6-01-2, Aoba, Sendai 980-8579 (Japan); Kenmotsu, T. [Doshisha University, Kyotanabe, Kyoto 610-0321 (Japan); Matsumoto, Y. [Tokushima Bunri University, Yamashiro, Tokushima 770-8514 (Japan); Wada, M. [Doshisha University, Kyotanabe, Kyoto 610-0321 (Japan)

    2009-06-15

    We measured the characteristics of the reflected particles from a carbon nanowall (CNW) deposited on a W surface following the injection of 1-2 keV H{sup +} and O{sup +} ions. The reflected ion energies and intensities indicated a contribution from multiple scattering in the target. The reflection angular dependence of the reflected ion intensities reached the maximum around the mirror angle and showed a sharp distribution, which may be attributable to the effect due to the aligned structure of the CNW. The energies and intensities of the reflected ions decreased with the time of ion bombardment. The intensities and energies of the reflected ions were, however, recovered to some degree by baking the sample, indicating the surface modification due to retention of the injected particles during the injection. We used the Monte Carlo simulation code ACAT (Atomic Collision in Amorphous Target) to study these processes theoretically and the calculated results supported the experimental results.

  3. A Time-of-Flight System for Low Energy Charged Particles

    Science.gov (United States)

    Giordano, Micheal; Sadwick, Krystalyn; Fletcher, Kurt; Padalino, Stephen

    2013-10-01

    A time-of-flight system has been developed to measure the energy of charged particles in the keV range. Positively charged ions passing through very thin carbon films mounted on grids generate secondary electrons. These electrons are accelerated by a -2000 V grid bias towards a grounded channeltron electron multiplier (CEM) which amplifies the signal. Two CEM detector assemblies are mounted 23.1 cm apart along the path of the ions. An ion generates a start signal by passing through the first CEM and a stop signal by passing through the second. The start and stop signals generate a time-of-flight spectrum via conventional electronics. Higher energy alpha particles from radioactive sources have been used to test the system. This time-of-flight system will be deployed to measure the energies of 15 to 30 keV ions produced by a duoplasmatron ion source that is used to characterize ICF detectors.

  4. A practical method for in-situ thickness determination using energy distribution of beta particles

    Energy Technology Data Exchange (ETDEWEB)

    Yalcin, S., E-mail: syalcin@kastamonu.edu.tr [Kastamonu University, Education Faculty, 37200 Kastamonu (Turkey); Gurler, O. [Physics Department, Faculty of Arts and Sciences, Uludag University, Gorukle Campus, 16059 Bursa (Turkey); Gundogdu, O. [Kocaeli University, Umuttepe Campus, 41380 Kocaeli (Turkey); Bradley, D.A. [CNRP, Department of Physics, Faculty of Engineering and Physical Sciences, University of Surrey, Guildford GU2 7XH (United Kingdom)

    2012-01-15

    This paper discusses a method to determine the thickness of an absorber using the energy distribution of beta particles. An empirical relationship was obtained between the absorber thickness and the energy distribution of beta particles transmitted through. The thickness of a polyethylene radioactive source cover was determined by exploiting this relationship, which has largely been left unexploited allowing us to determine the in-situ cover thickness of beta sources in a fast, cheap and non-destructive way. - Highlights: Black-Right-Pointing-Pointer A practical and in-situ unknown cover thickness determination Black-Right-Pointing-Pointer Cheap and readily available compared to other techniques. Black-Right-Pointing-Pointer Beta energy spectrum.

  5. Annotated references on shielding experiment and calculation of high energy particles

    International Nuclear Information System (INIS)

    Hirayama, H.; Ban, S.; Nakamura, T.

    1990-12-01

    The literature on shielding experiment and calculation of high energy particles above 20 MeV has been surveyed. The survey covers thirteen journals, from 1965 up to 1989. For each paper, applicable information is listed on type and energy of the projectile, the accelerator used, composition and thickness of the target and shielding materials, shielding geometry, the experimental and calculational methods, and the quantities obtained. The references on shielding experiment and on shielding calculation are accessed through two indices which list the projectile-target and shielding material combination, shielding geometry and the projectile energy range. The literature on neutron, photon and hadron production from thick target bombarded by charged particles has been surveyed mainly from 1984 as a complement of the previous work. (author)

  6. Effect of energy deposited by cosmic-ray particles on interferometric gravitational wave detectors

    International Nuclear Information System (INIS)

    Yamamoto, Kazuhiro; Hayakawa, Hideaki; Okada, Atsushi; Uchiyama, Takashi; Miyoki, Shinji; Ohashi, Masatake; Kuroda, Kazuaki; Kanda, Nobuyuki; Tatsumi, Daisuke; Tsunesada, Yoshiki

    2008-01-01

    We investigated the noise of interferometric gravitational wave detectors due to heat energy deposited by cosmic-ray particles. We derived a general formula that describes the response of a mirror against a cosmic-ray passage. We found that there are differences in the comic-ray responses (the dependence of temperature and cosmic-ray track position) in cases of interferometric and resonant gravitational wave detectors. The power spectral density of vibrations caused by low-energy secondary muons is 100 times smaller than the goal sensitivity of future second-generation interferometer projects, such as LCGT and Advanced LIGO. The arrival frequency of high-energy cosmic-ray muons that generate enough large showers inside mirrors of LCGT and Advanced LIGO is one per a millennium. We also discuss the probability of exotic-particle detection with interferometers.

  7. New directions in elementary particle physics: p anti p from very low to very high energies

    International Nuclear Information System (INIS)

    Jacob, M.

    1979-01-01

    The review covers low energy anti pp physics including annihilation processes, the spectroscopy of baryonium states, quasinuclear states and their relation to baryonium, the spectroscopy of protonium, and access to the whole charmonium family. High energy anti pp physics is reviewed covering total cross section rise, the common shape of cross sections, real part of forward amplitude, particle production, quantum number excitation, high transverse momentum, and high mass lepton pair. Also reviewed are the search for the weak bosons, hadron physics at collider energies, and the anti pp collider program. 47 references

  8. Search for solar Axion Like Particles in the low energy range at CAST

    International Nuclear Information System (INIS)

    Cantatore, G.; Karuza, M.; Lozza, V.; Raiteri, G.

    2010-01-01

    Axion Like Particles (ALPs) could be continuously produced in the Sun via the Primakoff process. The ALP flux could be seen on Earth by observing the photons produced by the ALP decay. The expected energy distribution of reconverted photons is peaked at 3 keV. There could be, however, a low energy tail due to various processes active in the Sun. We report results of the first test measurements in the low energy range performed at CAST along with a description of the experimental setup. Future detector developments are discussed and preliminary results on a liquid nitrogen cooled Avalanche Photodiode are presented.

  9. Particle damage sources for fused silica optics and their mitigation on high energy laser systems.

    Science.gov (United States)

    Bude, J; Carr, C W; Miller, P E; Parham, T; Whitman, P; Monticelli, M; Raman, R; Cross, D; Welday, B; Ravizza, F; Suratwala, T; Davis, J; Fischer, M; Hawley, R; Lee, H; Matthews, M; Norton, M; Nostrand, M; VanBlarcom, D; Sommer, S

    2017-05-15

    High energy laser systems are ultimately limited by laser-induced damage to their critical components. This is especially true of damage to critical fused silica optics, which grows rapidly upon exposure to additional laser pulses. Much progress has been made in eliminating damage precursors in as-processed fused silica optics (the advanced mitigation process, AMP3), and very high damage resistance has been demonstrated in laboratory studies. However, the full potential of these improvements has not yet been realized in actual laser systems. In this work, we explore the importance of additional damage sources-in particular, particle contamination-for fused silica optics fielded in a high-performance laser environment, the National Ignition Facility (NIF) laser system. We demonstrate that the most dangerous sources of particle contamination in a system-level environment are laser-driven particle sources. In the specific case of the NIF laser, we have identified the two important particle sources which account for nearly all the damage observed on AMP3 optics during full laser operation and present mitigations for these particle sources. Finally, with the elimination of these laser-driven particle sources, we demonstrate essentially damage free operation of AMP3 fused silica for ten large optics (a total of 12,000 cm 2 of beam area) for shots from 8.6 J/cm 2 to 9.5 J/cm 2 of 351 nm light (3 ns Gaussian pulse shapes). Potentially many other pulsed high energy laser systems have similar particle sources, and given the insight provided by this study, their identification and elimination should be possible. The mitigations demonstrated here are currently being employed for all large UV silica optics on the National Ignition Facility.

  10. Diagnosing collisionless energy transfer using field-particle correlations: Vlasov-Poisson plasmas

    Science.gov (United States)

    Howes, Gregory G.; Klein, Kristopher G.; Li, Tak Chu

    2017-02-01

    Turbulence plays a key role in the conversion of the energy of large-scale fields and flows to plasma heat, impacting the macroscopic evolution of the heliosphere and other astrophysical plasma systems. Although we have long been able to make direct spacecraft measurements of all aspects of the electromagnetic field and plasma fluctuations in near-Earth space, our understanding of the physical mechanisms responsible for the damping of the turbulent fluctuations in heliospheric plasmas remains incomplete. Here we propose an innovative field-particle correlation technique that can be used to measure directly the secular energy transfer from fields to particles associated with collisionless damping of the turbulent fluctuations. Furthermore, this novel procedure yields information about the collisionless energy transfer as a function of particle velocity, providing vital new information that can help to identify the dominant collisionless mechanism governing the damping of the turbulent fluctuations. Kinetic plasma theory is used to devise the appropriate correlation to diagnose Landau damping, and the field-particle correlation technique is thoroughly illustrated using the simplified case of the Landau damping of Langmuir waves in a 1D-1V (one dimension in physical space and one dimension in velocity space) Vlasov-Poisson plasma. Generalizations necessary to apply the field-particle correlation technique to diagnose the collisionless damping of turbulent fluctuations in the solar wind are discussed, highlighting several caveats. This novel field-particle correlation technique is intended to be used as a primary analysis tool for measurements from current, upcoming and proposed spacecraft missions that are focused on the kinetic microphysics of weakly collisional heliospheric plasmas, including the Magnetospheric Multiscale (MMS), Solar Probe Plus, Solar Orbiter and Turbulence Heating ObserveR (THOR) missions.

  11. Wideband converter of a charge of particle beam incident on a Faraday cylinder into a number of pulses

    International Nuclear Information System (INIS)

    Shchagin, A.V.; Lysenko, V.F.

    1985-01-01

    An electric circuit of a beam positive charge-pulse converter during beam incidence on a Faraday cylinder (conversion of Faraday cylinder current into F frequency, where F=10 10 J, where J - is the Faraday cylinder current) is described. Conversion ratio is 10 10 pulses/KP (10 10 Hz/A). Input current change limits are 10 -10 -10 -4 A. Conversion error is |ΔF| -3 F +0.1 Hz). ''Dead'' time is absent. Input resistance of the converter is close to zero

  12. MnBi particles with high energy density made by spark erosion

    Energy Technology Data Exchange (ETDEWEB)

    Nguyen, Phi-Khanh, E-mail: phi@ucsd.edu; Jin, Sungho [Materials Science and Engineering, University of California, San Diego, La Jolla, California 92093 (United States); Center for Magnetic Recording Research, University of California, San Diego, La Jolla, California 92093 (United States); Berkowitz, Ami E. [Physics Department, University of California, San Diego, La Jolla, California 92093 (United States); Center for Magnetic Recording Research, University of California, San Diego, La Jolla, California 92093 (United States)

    2014-05-07

    We report on the properties of low-temperature phase (LTP)-MnBi particles produced by the rapid-quenching technique of spark-erosion. The as-prepared powder consists of amorphous, crystalline, and superparamagnetic particles, mostly as porous aggregates. The major fraction of the powder consists of 20–30 nm particles. A short anneal crystallizes the amorphous particles producing a high moment, >90% of theoretical M{sub S}, albeit with H{sub C} of a few kOe. If lightly milled, the agglomerates are broken up to yield H{sub C} of 1 T. These findings are supported by the x-ray diffraction pattern showing broadened peaks of the predominant LTP-MnBi phase. The combination of spark erosion, milling, and annealing has produced randomly oriented particles with (BH){sub MAX} ∼ 3.0 MGOe. The particles are expected to show record energy product when aligned along their crystallographic easy axes.

  13. Bulk GaN alpha-particle detector with large depletion region and improved energy resolution

    Science.gov (United States)

    Xu, Qiang; Mulligan, Padhraic; Wang, Jinghui; Chuirazzi, William; Cao, Lei

    2017-03-01

    An alpha-particle detector was fabricated using a freestanding n-type bulk GaN wafer with a Au/Ni/GaN sandwich Schottky structure. Current-voltage measurements at room temperature revealed a Schottky contact with a leakage current of 7.53±0.3 nA at a reverse bias of 200 V. The detector had a large depletion depth that can capture much of the energy from 5.486 MeV alpha particles emitted from a 241Am source. The resolution of its alpha-particle energy spectrum was improved to 2.2±0.2% at 5.486 MeV under a bias of 550 V. This superior resolution was attributed to the shortening of the carrier transit time and the large energy deposition within the large depletion depth, i.e., 27 μm at -550 V, which all resulted in a more complete charge collection. A model developed using the ATLAS simulation framework from Silvaco Inc. was employed to study the charge collection process. The simulation results were found to agree closely with the experimental results. This detector will be beneficial for research at neutron scattering facilities, the International Thermonuclear Experimental Reactor, and the Large Hadron Collider, among other institutions, where the Si-based charged particle detectors could be quickly degraded in an intense radiation field.

  14. Binary projectile fragmentation of 12C at an incident energy of 33.3 MeV/nucleon

    CERN Document Server

    Förtsch, S V; Gadioli, E; Bassini, R; Buthelezi, E Z; Cerutti, F; Connell, S H; Cowley, A A; Fujita, H; Mabiala, J; Mairani, A; Mira, J; Papka, P; Neveling, R; Smit, F D

    2010-01-01

    Direct binary projectile fragmentation is being investigated for the case where a 400 MeV 12C projectile breaks up into an particle and a 8Be fragment in the interaction with a thin 93Nb and 197Au target. While the 8Be fragments were measured at 9 , the correlated particles were detected in an angular range between 16 and 30 on the opposite side of the beam. From the preliminary results presented here one may obtain information on the amount of quasi-elastic fragmentation (both fragments do not suffer any further interactions after they are produced). These experimental results indicate that the quasi-elastic break-up process is the dominant contribution to the measured correlation spectra. As was also observed in earlier work, the most forward quasi-elastically emitted particles have energies exceeding the beam velocity.

  15. Evolution of Single-Particle Energies for N=9 Nuclei at Large N/Z

    Directory of Open Access Journals (Sweden)

    Wuosmaa A. H.

    2014-03-01

    Full Text Available We have studied the nucleus 14B using the 13B(d,p14B and 15C(d,3He14B reactions. The two reactions provide complementary information about the negative-parity 1s1/2 and 0d5/2 neutron single-particle states in 14B. The data from the (d,p reaction give neutron-spectroscopic strengths for these levels, and the (d,3He results confirm the existence of a broad 2- excited state suggested in the literature. Together these results provide estimates of the sd-shell neutron effective single-particle energies in 14B.

  16. Energy spectra and asymmetry of charged particle emission in the muon minus capture by nuclei

    International Nuclear Information System (INIS)

    Balandin, M.P.; Grebenyuk, V.M.; Sinov, V.G.; Konin, A.D.

    1978-01-01

    Energy spectra of separated-by-mass single-charged particles at the capture of 130 MeV negative muons by carbon, oxygen, magnesium and sulphur have been measured. The experimental results are compared with the theoretical calculations at the assumption of preequilibrium decay of collective states described by the hydrodynamical model. The measurement of asymmetry of charged particle emission in sulphur and megnesium was carried out by hte method of muon spin precession in a magnetic field. Theoretical curves describe correctly the exponential spectra character, but the yields obtained are 2-3 times less than the experimental results

  17. Determination of polar cusp position by low-energy particle measurements made aboard AUREOLE satellite

    International Nuclear Information System (INIS)

    Gladyshev, V.A.; Jorjio, M.V.; Shuiskaya, F.K.; Crasnier, J.; Sauvaud, J.A.

    1974-01-01

    The Franco-Soviet experiment ARCAD, launched aboard the satellite AUREOLE December 27, 1971, has verified the existence of a particle penetration from the transition zone up to ionospheric altitudes across the polar cusp. The polar cusp is characterized by proton fluxes >10 7 particles/(cm 2 .s.sr.KeV) at 0.5KeV, with energy spectra similar to those in the transition zone. The position and form of the polar cusp are studied from measurements of protons in the range 0.4 to 30KeV during geomagnetically quiet periods (Kp [fr

  18. Complex energy eigenstates in a model with two equal mass particles

    Energy Technology Data Exchange (ETDEWEB)

    Gleiser, R J; Reula, D A; Moreschi, O M [Universidad Nacional de Cordoba (Argentina). Inst. de Matematica, Astronomia y Fisica

    1980-09-01

    The properties of a simples quantum mechanical model for the decay of two equal mass particles are studied and related to some recent work on complex energy eigenvalues. It consists essentially in a generalization of the Lee-Friedrichs model for an unstable particle and gives a highly idealized version of the K/sup 0/-anti K/sup 0/ system, including CP violations. The model is completely solvable, thus allowing a comparison with the well known Weisskopf-Wigner formalism for the decay amplitudes. A different model, describing the same system is also briefly outlined.

  19. Shower and Slow Particle Productions in Nucleus-Nucleus Collisions at High Energy

    International Nuclear Information System (INIS)

    Zayd, Hamdy M. M.; Rahim, Magda A.; Fakhraddin, S.

    2014-01-01

    The multiplicity distributions of shower, grey, and black particles produced in interactions of 4 He, 12 C, 16 O, 22 Ne, and 28 Si with emulsion (Em) at 4.1–4.5 A GeV/c beam energies, and their dependence on target groups (H, CNO, and AgBr) is presented and has been reproduced by multisource thermal model. The multiplicity and the angular distributions of the three types of particles have been investigated. The experimental results are compared with the corresponding ones from the model. We found that the experimental data agrees with theoretical calculations using multisource thermal model

  20. Effects of the particle-number projection on the isovector pairing energy

    International Nuclear Information System (INIS)

    Allal, N.H.; Fellah, M.; Oudih, M.R.; Benhamouda, N.

    2006-01-01

    The usual neutron-proton BCS wave function is simultaneously projected on both the good neutron and proton numbers using a discrete projection operator. The projected energy of the system is deduced as a limit of rapidly convergent sequence. It is numerically studied for the N=Z nuclei of which ''experimental'' pairing gaps may be deduced from the experimental odd-even mass differences. It then appears that the particle-number fluctuation effect is even more important than in the case of pairing between like-particles. (orig.)

  1. Gas-liquid transition in the model of particles interacting at high energy

    International Nuclear Information System (INIS)

    Bondarenko, S.; Komoshvili, K.

    2013-01-01

    An application of the ideas of the inertial confinement fusion process in the case of particles interacting at high energy is investigated. A possibility of the gas-liquid transition in the gas is considered using different approaches. In particular, a shock wave description of interactions between particles is studied and a self-similar solution of Euler's equation is discussed. Additionally, the Boltzmann equation is solved for a self-consistent field (Vlasov's equation) in the linear approximation for the case of a gas under external pressure and the corresponding change of the Knudsen number of the system is calculated. (orig.)

  2. Multiplicity distribution and multiplicity moment of black and grey particles in high energy nucleus–nucleus interactions

    International Nuclear Information System (INIS)

    Ghosh, Dipak; Deb, Argha; Datta, Utpal; Bhattacharyya, S.

    2011-01-01

    In this paper we have studied the multiplicity distribution of black and grey particles emitted from 16 O–AgBr interactions at 2.1 AGeV and 60 AGeV. We have also calculated the multiplicity moment up to the fifth order for both the interactions and for both kinds of emitted particles. The variation of multiplicity moment with the order number has been investigated. It is seen that in the case of black particles multiplicity moment up to fourth order remains almost constant as energy increases from 2.1 AGeV to 60 AGeV. Fifth order multiplicity moment increases insignificantly with energy. However in the case of grey particles no such constancy of multiplicity moment with energy of the projectile beam is obtained. Later we have extended our study on the basis of Regge–Mueller approach to find the existence of second order correlation during the emission of black as well as the grey particles. The second Mueller moment is found to be positive and it increases as energy increases in the case of black particles. On the contrary in the case of grey particles the second Mueller moment decreases with energy. It can be concluded that as energy increases correlation among the black particles increases. On the other hand with the increase of energy correlation among the grey particles is found to diminish. (author)

  3. Energy and operation management of a microgrid using particle swarm optimization

    Science.gov (United States)

    Radosavljević, Jordan; Jevtić, Miroljub; Klimenta, Dardan

    2016-05-01

    This article presents an efficient algorithm based on particle swarm optimization (PSO) for energy and operation management (EOM) of a microgrid including different distributed generation units and energy storage devices. The proposed approach employs PSO to minimize the total energy and operating cost of the microgrid via optimal adjustment of the control variables of the EOM, while satisfying various operating constraints. Owing to the stochastic nature of energy produced from renewable sources, i.e. wind turbines and photovoltaic systems, as well as load uncertainties and market prices, a probabilistic approach in the EOM is introduced. The proposed method is examined and tested on a typical grid-connected microgrid including fuel cell, gas-fired microturbine, wind turbine, photovoltaic and energy storage devices. The obtained results prove the efficiency of the proposed approach to solve the EOM of the microgrids.

  4. Detection of low-energy antinuclei in space using an active-target particle detector

    Energy Technology Data Exchange (ETDEWEB)

    Poeschl, Thomas; Greenwald, Daniel; Konorov, Igor; Paul, Stephan [Physics Department E18, Technische Universitaet Muenchen (Germany); Losekamm, Martin [Physics Department E18, Technische Universitaet Muenchen (Germany); Institute of Astronautics, Technische Universitaet Muenchen (Germany)

    2015-07-01

    Measuring antimatter in space excellently probes various astrophysical processes. The abundances and energy spectra of antiparticles reveal a lot about the creation and propagation of cosmic-ray particles in the universe. Abnormalities in their spectra can reveal exotic sources or inaccuracies in our understanding of the involved processes. The measurement of antiprotons and the search for antideuterons and antihelium are optimal at low kinetic energies since background from high-energy cosmic-ray collisions is low. For this reason, we are developing an active-target particle detector capable of detecting ions and anti-ions in the energy range of 30-100 MeV per nucleon. The detector consists of 900 scintillating fibers coupled to silicon photomultipliers and is designed to operate on nanosatellites. The primary application of the detector will be the Antiproton Flux in Space (AFIS) mission, whose goal is the measurement of geomagnetically trapped antiprotons inside Earth's inner radiation belt. In this talk, we explain our particle identification technique and present results from first in-beam measurements with a prototype.

  5. Software tool for representation and processing of experimental data on high energy interactions of elementary particles

    International Nuclear Information System (INIS)

    Cherepanov, E.O.; Skachkov, N.B.

    2002-01-01

    The software tool is developed for detailed and evident displaying of information about energy and space distribution of secondary particles produced in the processes of elementary particles collisions. As input information the data on the components of 4-momenta of secondary particles is used. As for these data the information obtained from different parts of physical detector (for example, from the calorimeter or tracker) as well as the information obtained with the help of event generator is taken. The tool is intended for use in Windows operation system and is developed on the basis of Borland Delphi. Mathematical architecture of the software tool allows user to receive complete information without making additional calculations. The program automatically performs analysis of structure and distributions of signals and displays the results in a transparent form which allows their quick analysis. To display the information the three-dimensional graphic methods as well as colour decisions based on intuitive associations are also used. (author)

  6. Hands on CERN an education project on the Internet using real high energy particle collisions

    CERN Document Server

    Johansson, E K

    1999-01-01

    An educational project primarily aimed at teachers and 15 to 18 year- old students describing the essential features of a modern high energy physics experiment has been created. The whole education package is available on the Internet. It gives a detailed description of the physics processes involved and the Standard Model of Microcosm. Real particle collisions produced with the facilities at the European particle physics laboratory (CERN) are displayed using the platform-independent programming language Java, enabling interaction with the user. The project has been used by several groups of teachers and students, and has increased their knowledge of, and interest in, particle physics. This project complements the traditional physics education and introduces students to contemporary fundamental physics. (7 refs).

  7. Rapidity correlations in inclusive two-particle production at storage ring energies

    CERN Document Server

    Dibon, Heinz; Gottfried, Christian; Nefkens, B M K; Neuhofer, G; Niebergall, F; Regler, Meinhard; Schmidt-Parzefall, W; Schubert, K R; Schumacher, P E; Winter, Klaus

    1973-01-01

    Inclusive two-particle production in the reaction pp to gamma +ch+ (anything) has been measured at the CERN ISR for four energies ( square root s=23, 30.5, 45, and 53 GeV) at two production angles of the charged particles (ch) and at eight production angles of the gamma -rays. The rapidity correlation of the two particles is weak and of short range. The peak correlation is sigma /sub inel/(d/sup 2/ sigma /sub gamma ch//d sigma /sub gamma /d sigma /sub ch/)-1=0.62+or-0.08, the correlation range (y/sub gamma /-y/sub ch/)=1.17+or-0.05, independently of s. The phi correlation extends over a wide gap in rapidity; its strength is increasing with increasing transverse momentum. (7 refs).

  8. Centroids of effective interactions from measured single-particle energies: An application

    International Nuclear Information System (INIS)

    Cole, B.J.

    1990-01-01

    Centroids of the effective nucleon-nucleon interaction for the mass region A=28--64 are extracted directly from experimental single-particle spectra, by comparing single-particle energies relative to different cores. Uncertainties in the centroids are estimated at approximately 100 keV, except in cases of exceptional fragmentation of the single-particle strength. The use of a large number of inert cores allows the dependence of the interaction on mass or model space to be investigated. The method permits accurate empirical modifications to be made to realistic interactions calculated from bare nucleon-nucleon potentials, which are known to possess defective centroids in many cases. In addition, the centroids can be used as input to the more sophisticated fitting procedures that are employed to produce matrix elements of the effective interaction

  9. Low-energy particle experiments-electron analyzer (LEPe) onboard the Arase spacecraft

    Science.gov (United States)

    Kazama, Yoichi; Wang, Bo-Jhou; Wang, Shiang-Yu; Ho, Paul T. P.; Tam, Sunny W. Y.; Chang, Tzu-Fang; Chiang, Chih-Yu; Asamura, Kazushi

    2017-12-01

    In this report, we describe the low-energy electron instrument LEPe (low-energy particle experiments-electron analyzer) onboard the Arase (ERG) spacecraft. The instrument measures a three-dimensional distribution function of electrons with energies of ˜ 19 eV-19 keV. Electrons in this energy range dominate in the inner magnetosphere, and measurement of such electrons is important in terms of understanding the magnetospheric dynamics and wave-particle interaction. The instrument employs a toroidal tophat electrostatic energy analyzer with a passive 6-mm aluminum shield. To minimize background radiation effects, the analyzer has a background channel, which monitors counts produced by background radiation. Background counts are then subtracted from measured counts. Electronic components are radiation tolerant, and 5-mm-thick shielding of the electronics housing ensures that the total dose is less than 100 kRad for the one-year nominal mission lifetime. The first in-space measurement test was done on February 12, 2017, showing that the instrument functions well. On February 27, the first all-instrument run test was done, and the LEPe instrument measured an energy dispersion event probably related to a substorm injection occurring immediately before the instrument turn-on. These initial results indicate that the instrument works fine in space, and the measurement performance is good for science purposes.[Figure not available: see fulltext.

  10. Calculation of Quasi-Particle Energies of Aromatic Self-Assembled Monolayers on Au(111).

    Science.gov (United States)

    Li, Yan; Lu, Deyu; Galli, Giulia

    2009-04-14

    We present many-body perturbation theory calculations of the electronic properties of phenylene diisocyanide self-assembled monolayers (SAMs) on a gold surface. Using structural models obtained within density functional theory (DFT), we have investigated how the SAM molecular energies are modified by self-energy corrections and how they are affected by the presence of the surface. We have employed a combination of GW (G = Green's function; W = screened Coulomb interaction) calculations of the SAM quasi-particle energies and a semiclassical image potential model to account for surface polarization effects. We find that it is essential to include both quasi-particle corrections and surface screening in order to provide a reasonable estimate of the energy level alignment at a SAM-metal interface. In particular, our results show that within the GW approximation the energy distance between phenylene diisocyanide SAM energy levels and the gold surface Fermi level is much larger than that found within DFT, e.g., more than double in the case of low packing densities of the SAM.

  11. Polarized proton induced pion production on 10B at 200, 225, 250 and 260 MeV incident energies

    International Nuclear Information System (INIS)

    Ziegler, W.; Auld, E.G.; Falk, W.R.; Giles, G.L.; Jones, G.; Lolos, G.J.; McParland, B.

    1985-02-01

    The angular distributions of both the differential cross-section and the analyzing power are presented for the 10 B(p,π) 11 B reaction leading to the ground and first excited states of 11 B. The differential cross-section shows very little angular structure or energy dependence, but the analyzing power exhibits a considerable energy dependence for both states. This dependence, similar to that observed for the 12 C(p,π + ) 13 C reaction, may be a signature of the fact that single-particle final states are involved

  12. Particle and surfactant interactions effected polar and dispersive components of interfacial energy in nanocolloids

    Science.gov (United States)

    Harikrishnan, A. R.; Das, Sarit K.; Agnihotri, Prabhat K.; Dhar, Purbarun

    2017-08-01

    We segregate and report experimentally for the first time the polar and dispersive interfacial energy components of complex nanocolloidal dispersions. In the present study, we introduce a novel inverse protocol for the classical Owens Wendt method to determine the constitutive polar and dispersive elements of surface tension in such multicomponent fluidic systems. The effect of nanoparticles alone and aqueous surfactants alone are studied independently to understand the role of the concentration of the dispersed phase in modulating the constitutive elements of surface energy in fluids. Surfactants are capable of altering the polar component, and the combined particle and surfactant nanodispersions are shown to be effective in modulating the polar and dispersive components of surface tension depending on the relative particle and surfactant concentrations as well as the morphological and electrostatic nature of the dispersed phases. We observe that the combined surfactant and particle colloid exhibits a similar behavior to that of the particle only case; however, the amount of modulation of the polar and dispersive constituents is found to be different from the particle alone case which brings to the forefront the mechanisms through which surfactants modulate interfacial energies in complex fluids. Accordingly, we are able to show that the observations can be merged into a form of quasi-universal trend in the trends of polar and dispersive components in spite of the non-universal character in the wetting behavior of the fluids. We analyze the different factors affecting the polar and dispersive interactions in such complex colloids, and the physics behind such complex interactions has been explained by appealing to the classical dispersion theories by London, Debye, and Keesom as well as by Derjaguin-Landau-Verwey-Overbeek theory. The findings shed light on the nature of wetting behavior of such complex fluids and help in predicting the wettability and the degree of

  13. Observations of Solar Energetic Particle Anisotropies at MeV Energies from STEREO/LET

    Science.gov (United States)

    Leske, R. A.; Cummings, A. C.; Cohen, C.; Mewaldt, R. A.; Labrador, A. W.; Stone, E. C.; Wiedenbeck, M. E.; Christian, E. R.; von Rosenvinge, T. T.

    2016-12-01

    During the transport of solar energetic particles (SEPs) through interplanetary space, their pitch-angle distributions are modified by the competing effects of scattering and magnetic focusing. Thus, measurements of SEP anisotropies can reveal conditions such as magnetic field strength, topology, and turbulence levels at heliospheric locations far removed from the observer. Onboard each of the two STEREO spacecraft, the Low Energy Telescope (LET) measures angular distributions in the ecliptic for SEP protons, helium, and heavier ions up to iron with energies of about 2-12 MeV/nucleon. Anisotropies observed with this instrument include unidirectional outward beams at the onset of magnetically well-connected SEP events when particles experienced little scattering, bidirectional flows within many interplanetary coronal mass ejections, sunward particle flows when the spacecraft was magnetically connected to the back side of a shock, and loss-cone distributions when particles with large pitch angles were magnetically mirrored at a remote field enhancement that was too weak to reflect particles with the smallest pitch angles. Observations at a 1-minute cadence also revealed peculiar oscillations in the width of a beamed distribution at the onset of the 23 July 2012 extreme SEP event. The shapes of the pitch angle distributions often vary with energy and differ for H, He, and heavier species, perhaps as a result of rigidity dependence of the pitch angle diffusion coefficient. We present a selection of the more interesting LET anisotropy observations made throughout solar cycle 24 and discuss the implications of these observations for SEP transport in the heliosphere.

  14. Measurement of double differential cross sections of secondary neutrons in the incident energy range 9-13 MeV

    International Nuclear Information System (INIS)

    Tang Hongqing; Qi Bujia; Zhou Zuying; Sa Jun; Ke Zunjian; Sui Qingchang; Xia Haihong; Shen Guanren

    1992-01-01

    The status and technique of double differential cross section measurement of secondary neutrons in the incident neutron energy range 9 to 13 MeV is reviewed with emphasis on the work done at CIAE. There are scarce measurements of secondary neutron double differential cross sections in this energy region up to now. A main difficulty for this is lack of an applicable monoenergetic neutron source. When monoenergetic neutron energy reaches 8 Me/v, the break-up neutrons from the d + D or p + T reaction starts to become significant. It is difficult to get a pure secondary neutron spectrum induced only by monoenergetic neutrons. To solve this problem an abnormal fast neutron TOF facility was designed and tested. Double differential neutron emission cross sections of 238 U and 209 Bi at 10 MeV were obtained by combining the data measured by both normal and abnormal TOF spectrometers and a good agreement between measurement and calculation was achieved

  15. HEPD on NEXTSat-1: A High Energy Particle Detector for Measurements of Precipitating Radiation Belt Electrons

    Science.gov (United States)

    Sohn, Jongdae; Lee, Jaejin; Min, Kyoungwook; Lee, Junchan; Lee, Seunguk; Lee, Daeyoung; Jo, Gyeongbok; Yi, Yu; Na, Gowoon; Kang, Kyung-In; Shin, Goo-Hwan

    2018-05-01

    Radiation belt particles of the inner magnetosphere precipitate into the atmosphere in the subauroral regions when they are pitch-angle scattered into the loss cone by wave-particle interactions. Such particle precipitations are known to be especially enhanced during space storms, though they can also occur during quiet times. The observed characteristics of precipitating electrons can be distinctively different, in their time series as well as in their spectra, depending on the waves involved. The present paper describes the High Energy Particle Detector (HEPD) on board the Next Generation Small Satellite-1 (NEXTSat-1), which will measure these radiation belt electrons from a low-Earth polar orbit satellite to study the mechanisms related to electron precipitation in the sub-auroral regions. The HEPD is based on silicon barrier detectors and consists of three telescopes that are mounted on the satellite to have angles of 0°. 45°, and 90°, respectively with the local geomagnetic field during observations. With a high time resolution of 32 Hz and a high spectral resolution of 11 channels over the energy range from 350 keV to 2 MeV, together with the pitch angle information provided by the three telescopes, HEPD is capable of identifying physical processes, such as microbursts and dust-side relativistic electron precipitation (DREP) events associated with electron precipitations. NextSat-1 is scheduled for launch in early 2018.

  16. Fixed-target particle fluxes and radiation levels at SSC energies

    International Nuclear Information System (INIS)

    Dukes, E.C.

    1993-01-01

    The author calculates the charged particle fluxes and radiation doses from minimum ionizing particles (MIP), electromagnetic showers, and hadronic showers, in a fixed-target experiment at the SSC. This work follows the work of Groom, essentially boosting his results into the laboratory frame. The radiation in dense matter, such as a calorimeter, is produced by several sources: electromagnetic showers, hadronic showers, and minimum ionizing particles. The author does not consider other sources of radiation such as beam halo, a dependent effects, and low energy neutrons from secondary sources. Nor does he consider the effects of magnetic fields. Low energy neutrons have been shown to be an important source of radiation for collider experiments at the SSC. In fixed-target experiments, where the spectrometer is more open and where most detector elements are far away from secondary particle dumps, these sources are not as important. They are also very much detector and experimental hall dependent. Hence the results presented here are only a lower limit of the estimated radiation dose

  17. The inelastic scattering of medium energy {alpha} particles; Sur la diffusion inelastique des particules {alpha} a moyenne energie

    Energy Technology Data Exchange (ETDEWEB)

    Crut, M [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1960-07-01

    The aim of this work is to find out what are the properties of the so-called 'anomalous states' in medium weight nuclei. These states preferentially excited in the inelastic scattering of medium energy charged particles have an excitation energy at about 4 MeV for nuclei with Z {<=} 29 and in the range 2-3 MeV for high Z nuclei. From a combination of angular distribution data in the elastic and inelastic scattering of 30 MeV {alpha} particles, and correlation data between inelastic {alpha} particles and deexcitation {gamma} rays, we show that for even-even nuclei, we can attribute spin 3 and parity minus to these 'anomalous states'. This is quite in agreement with the interpretation of these levels suggested by Lane as due to collective octupole oscillations. We give a resume of the theories used in the analysis of the data and a description of the experimental set-up. (author) [French] Le but de cette etude est de determiner les proprietes des niveaux dits 'anormalement excites' lors de la diffusion inelastique des particules chargees de moyenne energie sur des noyaux de masse moyenne et lourde. L'energie de ces niveaux est de l'ordre de 4 MeV pour les noyaux avec Z {<=} 29 et de 2 a 3 MeV pour les noyaux de Z plus eleve. De l'examen des courbes de distribution angulaire des particules {alpha} de 30 MeV diffusees elastiquement et inelastiquement, et de la correlation angulaire entre {alpha} excitant ces niveaux 'anormaux' et {gamma} de desexcitation, on deduit que, dans le cas des pair-pair, on peut attribuer a ces niveaux spin 3 et parite moins. Ceci renforce l'hypothese emise par Lane qui attribue ces niveaux a des oscillations octupolaires de la surface du noyau. On donne un apercu des theories utilisees dans l'analyse des resultats et une description des dispositifs experimentaux. (auteur)

  18. Behaviour of the ZEUS uranium-scintillator calorimeter for low-energetic particles with energies of 0.2 - 10.0 GeV

    International Nuclear Information System (INIS)

    Fuertjes, A.

    1990-02-01

    A prototype for the high-resolution calorimeter (FCAL) of the ZEUS detector was tested at a test beam of the CERN PS for beam momenta between 0.5 GeV/c and 10.0 GeV/c. The response of the calorimeter to low-energetic electrons, positrons, pions of both polarities, and protons should be studied. Additionally the effect of dead matter in front of the calorimeter was experimentally studied. Following results could be determined: Electrons and Positrons of equal energy produce comparable signals in the detector. Their response is in the considered momentum range with an accuracy of below 1% linear. The energy resolution of the calorimeter for electrons and positrons in the studied energy interval amounts to 17.5%√E. The response of the calorimeter to π + and π - is similar down to momenta of 0.5 GeV/c. The e/π ratio reaches the value 1.0 for energies above 2 GeV. For small incident energies e/mip=0.62 result. The energy resolution for pions amounts for energies above 2 GeV about 34%/√E. For smaller particle energies improvements can be observed. Protons show an identical behaviour as the pions, if the interesting quantities are considered in dependence on their kinetic energy. Dead matter in the front of the calorimeter influences the particle signals of low-energetic positrons and pions. The pulse-height spectra of electrons remain symmetric, but shift to small values. This behaviour could be confirmed by Monte-Carlo calculations. Pions show a distribution becoming with increasing matter density more asymmetric. At energies up to 2 GeV a significant effect mean values, energy resolution, and e/h ratio can be recognized. Above 2 GeV no important nuisance of the response to positrons and pions can yet be observed. (orig.) [de

  19. Energy deposition by a 106Ru/106Rh eye applicator simulated using LEPTS, a low-energy particle track simulation

    International Nuclear Information System (INIS)

    Fuss, M.C.; Munoz, A.; Oller, J.C.; Blanco, F.; Williart, A.; Limao-Vieira, P.; Borge, M.J.G.; Tengblad, O.; Huerga, C.; Tellez, M.; Garcia, G.

    2011-01-01

    The present study introduces LEPTS, an event-by-event Monte Carlo programme, for simulating an ophthalmic 106 Ru/ 106 Rh applicator relevant in brachytherapy of ocular tumours. The distinctive characteristics of this code are the underlying radiation-matter interaction models that distinguish elastic and several kinds of inelastic collisions, as well as the use of mostly experimental input data. Special emphasis is placed on the treatment of low-energy electrons for generally being responsible for the deposition of a large portion of the total energy imparted to matter. - Highlights: → We present the Monte Carlo code LEPTS, a low-energy particle track simulation. → Carefully selected input data from 10 keV to 1 eV. → Application to an electron emitting Ru-106/Rh-106 plaque used in brachytherapy.

  20. A comparative analysis of mechanisms of fast light particles production in nucleus-nucleus collisions at low and intermediate energies

    CERN Document Server

    Denikin, A S

    2002-01-01

    The dynamics and the mechanisms of formation of pre-equilibrium light particles in nucleus-nucleus collisions at low and intermediate energies are discussed in terms of a classical four-body model. The energy and angular distributions of light particles have been calculated. It has been found that at energies lower than 50A MeV the formation of the most high-energy part of the nuclear spectrum occurs at the expense of the acceleration of light target particles with the mean field of the projectile. The obtained data are in good agreement with available experimental data

  1. 25th Anniversary Article: Polymer-Particle Composites: Phase Stability and Applications in Electrochemical Energy Storage

    KAUST Repository

    Srivastava, Samanvaya

    2013-12-09

    Polymer-particle composites are used in virtually every field of technology. When the particles approach nanometer dimensions, large interfacial regions are created. In favorable situations, the spatial distribution of these interfaces can be controlled to create new hybrid materials with physical and transport properties inaccessible in their constituents or poorly prepared mixtures. This review surveys progress in the last decade in understanding phase behavior, structure, and properties of nanoparticle-polymer composites. The review takes a decidedly polymers perspective and explores how physical and chemical approaches may be employed to create hybrids with controlled distribution of particles. Applications are studied in two contexts of contemporary interest: battery electrolytes and electrodes. In the former, the role of dispersed and aggregated particles on ion-transport is considered. In the latter, the polymer is employed in such small quantities that it has been historically given titles such as binder and carbon precursor that underscore its perceived secondary role. Considering the myriad functions the binder plays in an electrode, it is surprising that highly filled composites have not received more attention. Opportunities in this and related areas are highlighted where recent advances in synthesis and polymer science are inspiring new approaches, and where newcomers to the field could make important contributions. Polymer-particle composites are used in virtually every field of technology. When the particles approach nanometer dimensions, large interfacial regions are created that can be exploited for applications. The fundamental approaches and bottom-up synthesis strategies for understanding and controlling nanoparticle dispersion in polymers are reviewed. Applications of these approaches for creating polymer-particle composite electrolytes and electrodes for energy storage are also considered. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  2. Space distribution and energy straggling of charged particles via Fokker-Planck equation

    International Nuclear Information System (INIS)

    Manservisi, S.; Molinari, V.; Nespoli, A.

    1996-01-01

    The Fokker-Planck equation describing a beam of charged particles entering a homogeneous medium is solved here for a stationary case. Interactions are taken into account through Coulomb cross-section. Starting from the charged-particle distribution as a function of velocity and penetration depth, some important kinetic quantities are calculated, like mean velocity, range and the loss of energy per unit space. In such quantities the energy straggling is taken into account. This phenomenon is not considered in the continuous slowing-down approximation that is commonly used to obtain the range and the stopping power. Finally the well-know Bohr of Bethe formula is found as a first-order approximation of the Fokker-Planck equation

  3. Sputtering yields of carbon based materials under high particle flux with low energy

    Science.gov (United States)

    Nakamura, K.; Nagase, A.; Dairaku, M.; Akiba, M.; Araki, M.; Okumura, Y.

    1995-04-01

    A new ion source which can produce high particle flux beams at low energies has been developed. This paper presents preliminary results on the sputtering yield of the carbon fiber reinforced composites (CFCs) measured with the new ion source. The sputtering yields of 1D and 2D CFCs, which are candidate materials for the divertor armour tiles, have been measured by the weight loss method under the hydrogen and deuterium particle fluxes of 2 ˜ 7 × 10 20/m 2 s at 50 ˜ 150 eV. Preferential sputtering of the matrix was observed on CFCs which included the matrix of 40 ˜ 60 w%. The energy dependence of the sputtering yields was weak. The sputtering yields of CFCs normally irradiated with deuterium beam were from 0.073 to 0.095, and were around three times larger than those with hydrogen beam.

  4. Sputtering yields of carbon based materials under high particle flux with low energy

    International Nuclear Information System (INIS)

    Nakamura, K.; Nagase, A.; Dairaku, M.; Akiba, M.; Araki, M.; Okumura, Y.

    1995-01-01

    A new ion source which can produce high particle flux beams at low energies has been developed. This paper presents preliminary results on the sputtering yield of the carbon fiber reinforced composites (CFCs) measured with the new ion source. The sputtering yields of 1D and 2D CFCs, which are candidate materials for the divertor armour tiles, have been measured by the weight loss method under the hydrogen and deuterium particle fluxes of 2 similar 7x10 20 /m 2 s at 50 similar 150 eV. Preferential sputtering of the matrix was observed on CFCs which included the matrix of 40 similar 60 w%. The energy dependence of the sputtering yields was weak. The sputtering yields of CFCs normally irradiated with deuterium beam were from 0.073 to 0.095, and were around three times larger than those with hydrogen beam. ((orig.))

  5. An Alternative Derivation of the Energy Levels of the "Particle on a Ring" System

    Science.gov (United States)

    Vincent, Alan

    1996-10-01

    All acceptable wave functions must be continuous mathematical functions. This criterion limits the acceptable functions for a particle in a linear 1-dimensional box to sine functions. If, however, the linear box is bent round into a ring, acceptable wave functions are those which are continuous at the 'join'. On this model some acceptable linear functions become unacceptable for the ring and some unacceptable cosine functions become acceptable. This approach can be used to produce a straightforward derivation of the energy levels and wave functions of the particle on a ring. These simple wave mechanical systems can be used as models of linear and cyclic delocalised systems such as conjugated hydrocarbons or the benzene ring. The promotion energy of an electron can then be used to calculate the wavelength of absorption of uv light. The simple model gives results of the correct order of magnitude and shows that, as the chain length increases, the uv maximum moves to longer wavelengths, as found experimentally.

  6. Excitation Functions for Charged Particle Induced Reactions in Light Elements at Low Projectile Energies

    International Nuclear Information System (INIS)

    Lorenzen, J.; Brune, D.

    1973-01-01

    The present chapter has been formulated with the aim of making it useful in various fields of nuclear applications with emphasis on charged particle activation analysis. Activation analysis of light elements using charged particles has proved to be an important tool in solving various problems in analytical chemistry, e g those associated with metal surfaces. Scientists desiring to evaluate the distribution of light elements in the surface of various matrices using charged particle reactions require accurate data on cross sections in the MeV-region. A knowledge of cross section data and yield-functions is of great interest in many applied fields involving work with charged particles, such as radiological protection and health physics, material research, semiconductor material investigations and corrosion chemistry. The authors therefore decided to collect a limited number of data which find use in these fields. Although the compilation is far from being complete, it is expected to be of assistance in devising measurements of charged particle reactions in Van de Graaff or other low energy accelerators

  7. Excitation Functions for Charged Particle Induced Reactions in Light Elements at Low Projectile Energies

    Energy Technology Data Exchange (ETDEWEB)

    Lorenzen, J; Brune, D

    1973-07-01

    The present chapter has been formulated with the aim of making it useful in various fields of nuclear applications with emphasis on charged particle activation analysis. Activation analysis of light elements using charged particles has proved to be an important tool in solving various problems in analytical chemistry, e g those associated with metal surfaces. Scientists desiring to evaluate the distribution of light elements in the surface of various matrices using charged particle reactions require accurate data on cross sections in the MeV-region. A knowledge of cross section data and yield-functions is of great interest in many applied fields involving work with charged particles, such as radiological protection and health physics, material research, semiconductor material investigations and corrosion chemistry. The authors therefore decided to collect a limited number of data which find use in these fields. Although the compilation is far from being complete, it is expected to be of assistance in devising measurements of charged particle reactions in Van de Graaff or other low energy accelerators

  8. Variation of energy absorption and exposure buildup factors with incident photon energy and penetration depth for boro-tellurite (B2O3-TeO2) glasses

    Science.gov (United States)

    Sayyed, M. I.; Elhouichet, H.

    2017-01-01

    The gamma ray energy absorption (EABF) and exposure buildup factors (EBF) of (100-x)TeO2-xB2O3 glass systems (where x=5, 10, 15, 20, 22.5 and 25 mol%) have been calculated in the energy region 0.015-15 MeV up to a penetration depth of 40 mfp (mean free path). The five parameters (G-P) fitting method has been used to estimate both EABF and EBF values. Variations of EABF and EBF with incident photon energy and penetration depth have been studied. It was found that EABF and EBF values were higher in the intermediate energy region, for all the glass systems. Furthermore, boro-tellurite glass with 5 mol% B2O3, was found to present the lowest EABF and EBF values, hence it is superior gamma-ray shielding material. The results indicate that the boro-tellurite glasses can be used as radiation shielding materials.

  9. Alpha particle spectroscopy for CR-39 detector utilizing matrix of energy equations

    Energy Technology Data Exchange (ETDEWEB)

    Awad, E.M. [Department of General Sciences, Yanbu Industrial College, PO Box 30436, Madinat Yanbu Al-Sinaiya (Saudi Arabia); Physics Department, Faculty of Science, Menofia University, Shebin El-Koom (Egypt)], E-mail: ayawad@yahoo.com; Soliman, A.A. [Department of Mathematics, Faculty of Education (AL-Arish), Suez Canal University, AL-Arish 45111 (Egypt); Department of Mathematics, Teacher' s College (Bisha), King Khalid University, Bisha, PO Box 551 (Saudi Arabia)], E-mail: asoliman_99@yahoo.com; Rammah, Y.S. [Physics Department, Faculty of Science, Menofia University, Shebin El-Koom (Egypt)

    2007-10-01

    A method for determining alpha-particle energy using CR-39 detector by utilizing matrix of energy equation was described. The matrix was composed from two axes; the track minor axis (m) and diameter of etched out track end (d) axis of some selected elliptical tracks. The energy E in (m,d) coordinate was approximated by matrix of energy equations given by: E{sub k}={sigma}{sub i,j=0}{sup 2}a{sub ij}d{sub k}{sup i}m{sub k}{sup j}, which was identified using two different approaches. First, i and j were treated as power exponents for d and m. The adjusting parameters values a{sub ij} were obtained and the energy of a given track was deduced directly from it. Second, i and j were treated as indices of some chosen tracks that were fitted to obtain iso-energy curves that were superimposed on m-d scatter plot as calibration curves. The energy between any two successive iso-energy curves in this case was assumed varied linearly with d for a given m. The energy matrix in both cases was solved numerically. Results of the two approaches were compared.

  10. Effective energies and exposure determinations of two different energy X-ray beams incident on a personnel monitor

    International Nuclear Information System (INIS)

    Okuno, E.; Cruz, M.T. da

    1984-01-01

    The effective energy of one X or gamma ray beam can be determined by means of two thermoluminescent (TL) dosemeters mounted between suitable filters. However, it has been observed that personnel monitors exposed to two different energy ionizing radiations provide different effective energies depeding on the type of TL phosphor used. This fact could be a powerful tool for identifying exposures to radiation with quite different effective energies which are very common in practice. Two types of TL dosemeters were used : pellets of cold pressed natural fluoride and NaCl developed in our own laboratory, and LiF, TLD-100 from Harshaw Chemical Co.. Experimental results obtained with these combined dosemeters after irradiation with different sets of exposures and energy values of ionizing radiations are also presented. (Author) [pt

  11. Feigenbaum scenario for turbulence and Cantorian E-infinity theory of high energy particle physics

    International Nuclear Information System (INIS)

    El Naschie, M.S.

    2007-01-01

    The work draws some fundamental connections between Feigenbaum's golden mean renormalization group and scenario for turbulence on the one side and high energy particle physics on the other side. The analysis which is based on the natural and obvious connections between the Fibonacci-like geometrical growth rate of ε (∞) spacetime and Feigenbaum's renormalization gives vital information to basic questions not only of quantum geometry, but also of quantum field theory

  12. Energy dependence of collective flow of neutrons and charged particles in 197Au+197Au collisions

    International Nuclear Information System (INIS)

    Blaich, T.; Freiesleben, H.; Holzmann, R.; Keller, J.G.; Prokopowicz, W.; Schuetter, C.; Wajda, E.; Zude, E.

    1994-01-01

    Our contribution focusses on one particular aspect of collective flow of nuclear matter: the so-called ''squeeze-out'', i.e. the preferential emission of mid-rapidity particles perpendicular to the reaction plane. The data were taken for the system 197 Au + 197 Au at 400, 600 and 800 MeV/u. We cover two topics, the comparison of neutrons and protons, and the bombarding energy dependence of the neutrons' squeeze-out. (orig.)

  13. Constraining the geometry to study jet energy loss with 2-particle correlations

    International Nuclear Information System (INIS)

    Pei, H.; Awes, Terry C.; Cianciolo, Vince; Efremenko, Yuri V.; Enokizono, Akitomo; Read, Kenneth F. Jr.; Silvermyr, David O.; Sorensen, Soren P.; Stankus, Paul W.; Young, Glenn R.

    2008-01-01

    Correlations between two high-p T hadrons provide information on how partons lose energy as they travel through the dense plasma formed at RHIC. To vary the path length partons travel, we measure the back-to-back jets in the AA collision of centrality and reaction-plane dependence, in addition to '2+1' particle correlations, and compare with p+p results

  14. Effect of the dielectric constant of mesoscopic particle on the exciton binding energy

    International Nuclear Information System (INIS)

    Lai Zuyou; Gu Shiwei

    1991-09-01

    For materials with big exciton reduced mass and big dielectric constant, such as TiO 2 , the variation of dielectric constant with the radius of an ultrafine particle (UFP) is important for determining the exciton binding energy. For the first time a phenomenological formula of the dielectric constant of a UFP with its radius in mesoscopic range is put forward in order to explain the optical properties of TiO 2 UFP. (author). 22 refs, 3 figs, 1 tab

  15. Description of charged particle multiplicity distribution in high energy strong interaction

    International Nuclear Information System (INIS)

    Qin Keyu

    1994-01-01

    With the assumption that the probability for n-charged particles production in hadron-hadron collision is Pn and proper choice of 1 , 2 , k and x in Pn, the true multiplicity distribution in full phase space can be described successfully at the centre of mass energy √S GeV. Using the experimental data of non singe-diffractive collisions between proton and antiproton at centre of mass energies of 200 and 900 GeV, the supposition has been examined and confirmed: it is very good to describe the facts. The theoretical bases of supposition were discussed

  16. Dependence of the quasipotential on the total energy of a two-particle system

    International Nuclear Information System (INIS)

    Kapshai, V.N.; Savrin, V.I.; Skachkov, N.B.

    1987-01-01

    For a system of two relativistic particles described in the Logunov-Tavkhelidze one-time approach the dependence of the quasipotential of one-boson exchange on the total energy of the system is calculated. It is shown that despite the nonlocal form of the obtained quasipotential the three-dimensional equations for the waves function can be reduced by a partial expansion to one-dimensional equations. The influence of the energy dependence of the quasipotential on its behavior in the coordinate representation is discussed

  17. On the dependence of quasipotential on the total energy of a two-particle system

    International Nuclear Information System (INIS)

    Kapshaj, V.N.; Savrin, V.I.

    1986-01-01

    For a system of two relativistic particles described in the framework of the Logunov-Tavkhelidze one-time approach the dependence is calculated of the one-boson exchange potential on the total energy of the system. It is shown that in spite of a nonlocal form of the quasipotential obtained, three-dimensional equations for the wave function are reduced to one-dimensional ones by means of partial expansion. Influence of the energy dependence of the quasipotential on its behaviour in the coordinate representation is discussed

  18. Phantom dark energy with varying-mass dark matter particles: Acceleration and cosmic coincidence problem

    International Nuclear Information System (INIS)

    Leon, Genly; Saridakis, Emmanuel N.

    2010-01-01

    We investigate several varying-mass dark matter particle models in the framework of phantom cosmology. We examine whether there exist late-time cosmological solutions, corresponding to an accelerating universe and possessing dark energy and dark matter densities of the same order. Imposing exponential or power-law potentials and exponential or power-law mass dependence, we conclude that the coincidence problem cannot be solved or even alleviated. Thus, if dark energy is attributed to the phantom paradigm, varying-mass dark matter models cannot fulfill the basic requirement that led to their construction.

  19. Searching for squeezed particle-antiparticle correlations in high-energy heavy-ion collisions

    International Nuclear Information System (INIS)

    Padula, Sandra S.; Socolowski, O. Jr.

    2010-01-01

    Squeezed correlations of particle-antiparticle pairs were predicted to exist if the hadron masses were modified in the hot and dense medium formed in high-energy heavy-ion collisions. Although well-established theoretically, they have not yet been observed experimentally. We suggest here a clear method to search for such a signal by analyzing the squeezed correlation functions in terms of measurable quantities. We illustrate this suggestion for simulated φφ pairs at the Relativistic Heavy Ion Collider (RHIC) energies.

  20. Momenta of particles emitted by target at intensive irradiation by low-energy ions

    CERN Document Server

    Beshenkov, V G; Marchenko, V A

    2002-01-01

    One measured the aggregate momenta of the target emitted particles at the intensive sputtering by E sub 0 approx = 0.5 keV energy heavy inert gases. For liquid and being under premelting temperature Ga target the measured values are close to the expected momenta of sputtered metallic atoms and reflection ions, for Cu and Zr targets they are essentially higher. One assumes that sputtering of atoms of gas-diffuser implanted into the target causes the surplus momentum. The estimated average energy of these atoms approx = 20 eV. Under Ga irradiation the implanted atoms diffuse mainly towards the surface and are desorbed

  1. Energy Dependence of Particle Multiplicities in Central Au+Au Collisions

    Science.gov (United States)

    Back, B. B.; Baker, M. D.; Barton, D. S.; Betts, R. R.; Bindel, R.; Budzanowski, A.; Busza, W.; Carroll, A.; Corbo, J.; Decowski, M. P.; Garcia, E.; George, N.; Gulbrandsen, K.; Gushue, S.; Halliwell, C.; Hamblen, J.; Henderson, C.; Hicks, D.; Hofman, D.; Hollis, R. S.; Hołyński, R.; Holzman, B.; Iordanova, A.; Johnson, E.; Kane, J.; Katzy, J.; Khan, N.; Kucewicz, W.; Kulinich, P.; Kuo, C. M.; Lin, W. T.; Manly, S.; McLeod, D.; Michałowski, J.; Mignerey, A.; Mülmenstädt, J.; Nouicer, R.; Olszewski, A.; Pak, R.; Park, I. C.; Pernegger, H.; Rafelski, M.; Rbeiz, M.; Reed, C.; Remsberg, L. P.; Reuter, M.; Roland, C.; Roland, G.; Rosenberg, L.; Sagerer, J.; Sarin, P.; Sawicki, P.; Skulski, W.; Steadman, S. G.; Steinberg, P.; Stephans, G. S.; Stodulski, M.; Sukhanov, A.; Tang, J.-L.; Teng, R.; Trzupek, A.; Vale, C.; van Nieuwenhuizen, G. J.; Verdier, R.; Wadsworth, B.; Wolfs, F. L.; Wosiek, B.; Woźniak, K.; Wuosmaa, A. H.; Wysłouch, B.

    2002-01-01

    We present the first measurement of the pseudorapidity density of primary charged particles in Au+Au collisions at (sNN) = 200 GeV. For the 6% most central collisions, we obtain dNch/dη\\|\\|η\\|<1 = 650+/-35(syst). Compared to collisions at (sNN) = 130 GeV, the highest energy studied previously, an increase by a factor of 1.14+/-0.05 at 90% confidence level, is found. The energy dependence of the pseudorapidity density is discussed in comparison with data from proton-induced collisions and theoretical predictions.

  2. A point kernel shielding code, PKN-HP, for high energy proton incident

    Energy Technology Data Exchange (ETDEWEB)

    Kotegawa, Hiroshi [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

    1996-06-01

    A point kernel integral technique code PKN-HP, and the related thick target neutron yield data have been developed to calculate neutron and secondary gamma-ray dose equivalents in ordinary concrete and iron shields for fully stopping length C, Cu and U-238 target neutrons produced by 100 MeV-10 GeV proton incident in a 3-dimensional geometry. The comparisons among calculation results of the present code and other calculation techniques, and measured values showed the usefulness of the code. (author)

  3. Active motions of Brownian particles in a generalized energy-depot model

    International Nuclear Information System (INIS)

    Zhang Yong; Koo Kim, Chul; Lee, Kong-Ju-Bock

    2008-01-01

    We present a generalized energy-depot model in which the rate of conversion of the internal energy into motion can be dependent on the position and velocity of a particle. When the conversion rate is a general function of the velocity, the active particle exhibits diverse patterns of motion, including a braking mechanism and a stepping motion. The phase trajectories of the motion are investigated in a systematic way. With a particular form of the conversion rate dependent on the position and velocity, the particle shows a spontaneous oscillation characterizing a negative stiffness. These types of active behaviors are compared with similar phenomena observed in biology, such as the stepping motion of molecular motors and amplification in the hearing mechanism. Hence, our model can provide a generic understanding of the active motion related to the energy conversion and also a new control mechanism for nano-robots. We also investigate the effect of noise, especially on the stepping motion, and observe random walk-like behavior as expected.

  4. Exploring the tensile strain energy absorption of hybrid modified epoxies containing soft particles

    International Nuclear Information System (INIS)

    Abadyan, M.; Bagheri, R.; Kouchakzadeh, M.A.; Hosseini Kordkheili, S.A.

    2011-01-01

    Research highlights: → Two epoxy systems have been modified by combination of fine and coarse modifiers. → While both hybrid systems reveal synergistic K IC , no synergism is observed in tensile test. → It is found that coarse particles induce stress concentration in hybrid samples. → Stress concentration leads to fracture of samples at lower energy absorption levels. -- Abstract: In this paper, tensile strain energy absorption of two different hybrid modified epoxies has been systematically investigated. In one system, epoxy has been modified by amine-terminated butadiene acrylonitrile (ATBN) and hollow glass spheres as fine and coarse modifiers, respectively. The other hybrid epoxy has been modified by the combination of ATBN and recycled Tire particles. The results of fracture toughness measurement of blends revealed synergistic toughening for both hybrid systems in some formulations. However, no evidence of synergism is observed in tensile test of hybrid samples. Scanning electron microscope (SEM), transmission optical microscope (TOM) and finite element (FEM) simulation were utilized to study deformation mechanisms of hybrid systems in tensile test. It is found that coarse particles induce stress concentration in hybrid samples. This produces non-uniform strain localized regions which lead to fracture of hybrid samples at lower tensile loading and energy absorption levels.

  5. Flowable Conducting Particle Networks in Redox-Active Electrolytes for Grid Energy Storage

    Energy Technology Data Exchange (ETDEWEB)

    Hatzell, K. B.; Boota, M.; Kumbur, E. C.; Gogotsi, Y.

    2015-01-01

    This study reports a new hybrid approach toward achieving high volumetric energy and power densities in an electrochemical flow capacitor for grid energy storage. The electrochemical flow capacitor suffers from high self-discharge and low energy density because charge storage is limited to the available surface area (electric double layer charge storage). Here, we examine two carbon materials as conducting particles in a flow battery electrolyte containing the VO2+/VO2+ redox couple. Highly porous activated carbon spheres (CSs) and multi-walled carbon nanotubes (MWCNTs) are investigated as conducting particle networks that facilitate both faradaic and electric double layer charge storage. Charge storage contributions (electric double layer and faradaic) are distinguished for flow-electrodes composed of MWCNTs and activated CSs. A MWCNT flow-electrode based in a redox-active electrolyte containing the VO2+/VO2+ redox couple demonstrates 18% less self-discharge, 10 X more energy density, and 20 X greater power densities (at 20 mV s-1) than one based on a non-redox active electrolyte. Furthermore, a MWCNT redox-active flow electrode demonstrates 80% capacitance retention, and >95% coulombic efficiency over 100 cycles, indicating the feasibility of utilizing conducting networks with redox chemistries for grid energy storage.

  6. An optimized surface plasmon photovoltaic structure using energy transfer between discrete nano-particles.

    Science.gov (United States)

    Lin, Albert; Fu, Sze-Ming; Chung, Yen-Kai; Lai, Shih-Yun; Tseng, Chi-Wei

    2013-01-14

    Surface plasmon enhancement has been proposed as a way to achieve higher absorption for thin-film photovoltaics, where surface plasmon polariton(SPP) and localized surface plasmon (LSP) are shown to provide dense near field and far field light scattering. Here it is shown that controlled far-field light scattering can be achieved using successive coupling between surface plasmonic (SP) nano-particles. Through genetic algorithm (GA) optimization, energy transfer between discrete nano-particles (ETDNP) is identified, which enhances solar cell efficiency. The optimized energy transfer structure acts like lumped-element transmission line and can properly alter the direction of photon flow. Increased in-plane component of wavevector is thus achieved and photon path length is extended. In addition, Wood-Rayleigh anomaly, at which transmission minimum occurs, is avoided through GA optimization. Optimized energy transfer structure provides 46.95% improvement over baseline planar cell. It achieves larger angular scattering capability compared to conventional surface plasmon polariton back reflector structure and index-guided structure due to SP energy transfer through mode coupling. Via SP mediated energy transfer, an alternative way to control the light flow inside thin-film is proposed, which can be more efficient than conventional index-guided mode using total internal reflection (TIR).

  7. Axion-like particle imprint in cosmological very-high-energy sources

    International Nuclear Information System (INIS)

    Domínguez, A.; Sánchez-Conde, M.A.; Prada, F.

    2011-01-01

    Discoveries of very high energy (VHE) photons from distant blazars suggest that, after correction by extragalactic background light (EBL) absorption, there is a flatness or even a turn-up in their spectra at the highest energies that cannot be easily explained by the standard framework. Here, it is shown that a possible solution to this problem is achieved by assuming the existence of axion-like particles (ALPs) with masses ∼ 1 neV. The ALP scenario is tested making use of observations of the highest redshift blazars known in the VHE energy regime, namely 3C 279, 3C 66A, PKS 1222+216 and PG 1553+113. In all cases, better fits to the observed spectra are found when including ALPs rather than considering EBL only. Interestingly, quite similar critical energies for photon/ALP conversions are also derived, independently of the source considered

  8. Singlet-triplet splittings from the virial theorem and single-particle excitation energies

    Science.gov (United States)

    Becke, Axel D.

    2018-01-01

    The zeroth-order (uncorrelated) singlet-triplet energy difference in single-particle excited configurations is 2Kif, where Kif is the Coulomb self-energy of the product of the transition orbitals. Here we present a non-empirical, virial-theorem argument that the correlated singlet-triplet energy difference should be half of this, namely, Kif. This incredibly simple result gives vertical HOMO-LUMO excitation energies in small-molecule benchmarks as good as the popular TD-B3LYP time-dependent approach to excited states. For linear acenes and nonlinear polycyclic aromatic hydrocarbons, the performance is significantly better than TD-B3LYP. In addition to the virial theorem, the derivation borrows intuitive pair-density concepts from density-functional theory.

  9. An application of Brookhaven National Laboratory's hot particle methodology for determining the most effective beta particle energy in causing skin ulcers

    International Nuclear Information System (INIS)

    Schaefer, C.

    1994-11-01

    The purpose of this project was to compare the effectiveness of hot particles with different energy betas in producing ulcers on skin. The sources were man-made hot particles similar in size and activity to those found in the commercial nuclear power industry. Four different particle types were used. These were thulium (Tm-170) with a 0.97 MeV maximum energy beta, ytterbium (Yb-175) with a maximum beta energy of 0.47 MeV, scandium (Sc-46) with a 0.36 MeV beta, which was used as a surrogate for cobalt-60 (0.31 MeV beta) and uranium (in the carbide form) with an average maximum beta energy of about 2.5 MeV. Since higher energy beta particles penetrate further in skin, they will affect a higher number and different populations of target cells. The experiments were designed as threshold studies such that the dose needed to produce ulcers ten percent of the time (ED 10%) for each particle type could be compared against each other

  10. Energy and energy gradient matrix elements with N-particle explicitly correlated complex Gaussian basis functions with L =1

    Science.gov (United States)

    Bubin, Sergiy; Adamowicz, Ludwik

    2008-03-01

    In this work we consider explicitly correlated complex Gaussian basis functions for expanding the wave function of an N-particle system with the L =1 total orbital angular momentum. We derive analytical expressions for various matrix elements with these basis functions including the overlap, kinetic energy, and potential energy (Coulomb interaction) matrix elements, as well as matrix elements of other quantities. The derivatives of the overlap, kinetic, and potential energy integrals with respect to the Gaussian exponential parameters are also derived and used to calculate the energy gradient. All the derivations are performed using the formalism of the matrix differential calculus that facilitates a way of expressing the integrals in an elegant matrix form, which is convenient for the theoretical analysis and the computer implementation. The new method is tested in calculations of two systems: the lowest P state of the beryllium atom and the bound P state of the positronium molecule (with the negative parity). Both calculations yielded new, lowest-to-date, variational upper bounds, while the number of basis functions used was significantly smaller than in previous studies. It was possible to accomplish this due to the use of the analytic energy gradient in the minimization of the variational energy.

  11. Energy and energy gradient matrix elements with N-particle explicitly correlated complex Gaussian basis functions with L=1.

    Science.gov (United States)

    Bubin, Sergiy; Adamowicz, Ludwik

    2008-03-21

    In this work we consider explicitly correlated complex Gaussian basis functions for expanding the wave function of an N-particle system with the L=1 total orbital angular momentum. We derive analytical expressions for various matrix elements with these basis functions including the overlap, kinetic energy, and potential energy (Coulomb interaction) matrix elements, as well as matrix elements of other quantities. The derivatives of the overlap, kinetic, and potential energy integrals with respect to the Gaussian exponential parameters are also derived and used to calculate the energy gradient. All the derivations are performed using the formalism of the matrix differential calculus that facilitates a way of expressing the integrals in an elegant matrix form, which is convenient for the theoretical analysis and the computer implementation. The new method is tested in calculations of two systems: the lowest P state of the beryllium atom and the bound P state of the positronium molecule (with the negative parity). Both calculations yielded new, lowest-to-date, variational upper bounds, while the number of basis functions used was significantly smaller than in previous studies. It was possible to accomplish this due to the use of the analytic energy gradient in the minimization of the variational energy.

  12. An optimized Nash nonlinear grey Bernoulli model based on particle swarm optimization and its application in prediction for the incidence of Hepatitis B in Xinjiang, China.

    Science.gov (United States)

    Zhang, Liping; Zheng, Yanling; Wang, Kai; Zhang, Xueliang; Zheng, Yujian

    2014-06-01

    In this paper, by using a particle swarm optimization algorithm to solve the optimal parameter estimation problem, an improved Nash nonlinear grey Bernoulli model termed PSO-NNGBM(1,1) is proposed. To test the forecasting performance, the optimized model is applied for forecasting the incidence of hepatitis B in Xinjiang, China. Four models, traditional GM(1,1), grey Verhulst model (GVM), original nonlinear grey Bernoulli model (NGBM(1,1)) and Holt-Winters exponential smoothing method, are also established for comparison with the proposed model under the criteria of mean absolute percentage error and root mean square percent error. The prediction results show that the optimized NNGBM(1,1) model is more accurate and performs better than the traditional GM(1,1), GVM, NGBM(1,1) and Holt-Winters exponential smoothing method. Copyright © 2014. Published by Elsevier Ltd.

  13. At what particle energy do extragalactic cosmic rays start to predominate?

    International Nuclear Information System (INIS)

    Wibig, Tadeusz; Wolfendale, Arnold W

    2005-01-01

    We have previously argued (e.g. Szabelski et al 2002 Astropart. Phys. 17 125) that the well-known 'ankle' in the cosmic ray energy spectrum, at log E (eV) ∼ 18.7-19.0, marks the transition from mainly galactic sources at lower energies to mainly extragalactic above. Recently, however, there have been claims for lower transitional energies, specifically from log E (eV) ∼ 17.0 (Thompson et al 2004 Proc. Catania Cosmic Ray Conf.) via 17.2-17.8 (Berezinsky et al 2004 Astropart. Phys. 21 617) to 18.0 (Hillas 2004 Proc. Leeds Cosmic Ray Conf.). In our model the ankle arises naturally from the sum of simple power law-spectra with slopes differing by Δγ ∼ 1.8; from differential slope γ = -3.8 for galactic particles (near log E = 19) to γ ∼ -2.0 for extragalactic sources. In the other models, on the other hand, the ankle is intrinsic to the extragalactic component alone, and arises from the shape of the rate of energy loss versus energy for the (assumed) protons interacting with the cosmic microwave background (CMB). Our detailed analysis of the world's data on the ultra-high energy spectrum shows that taken together, or separately, the resulting mean sharpness of the ankle (second derivative of the log(intensity x E 3 ) with respect to log E) is consistent with our 'mixed' model. For explanation in terms of extragalactic particles alone, however, the ankle will be at the wrong energy-for reasonable production models and of insufficient magnitude if, as seems likely, there is still a significant fraction of heavy nuclei at the ankle energy

  14. Energy Reflection Coefficients for 5-10 keV He Ions Incident on Au, Ag, and Cu

    DEFF Research Database (Denmark)

    Schou, Jørgen; Sørensen, H.; Littmark, U.

    1978-01-01

    The calorimetric deuterium-film method was used for measurements of the energy reflection coefficient γ for normal incidence of 5-10 keV He ions on Cu, Ag and Au. A theoretical calculation of γ by means of transport theory gives fair agreement with the experimental results. The experimental data...... the experimental and theoretical results for the He ions are in acceptable agreement with other experimental and theoretical results. For He ions, the experimental γ-values are 20-30% above the values for hydrogen ions for the same value of ε...

  15. The high energy multicharged particle exposure of the microbial ecology evaluation device on board the Apollo 16 spacecraft

    Science.gov (United States)

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

    1973-01-01

    The high energy multicharged cosmic-ray-particle exposure of the Microbial Ecology Evaluation Device package on board the Apollo 16 spacecraft was monitored using cellulose nitrate, Lexan polycarbonate, nuclear emulsion, and silver chloride crystal nuclear-track detectors. The results of the analysis of these detectors include the measured particle fluences, the linear energy transfer spectra, and the integral atomic number spectrum of stopping particle density. The linear energy transfer spectrum is used to compute the fractional cell loss in human kidney (T1) cells caused by heavy particles. Because the Microbial Ecology Evaluation Device was better shielded, the high-energy multicharged particle exposure was less than that measured on the crew passive dosimeters.

  16. Excitation energy and angular momentum of quasiprojectiles produced in the Xe+Sn collisions at incident energies between 25 and 50 MeV/nucleon

    International Nuclear Information System (INIS)

    Steckmeyer, J.C.; Genouin-Duhamel, E.; Vient, E.; Colin, J.; Durand, D.; Auger, G.; Bacri, C.O.; Bellaize, N.; Borderie, B.; Bougault, R.; Bouriquet, B.; Brou, R.; Buchet, P.; Charvet, J.L.; Chbihi, A.; Cussol, D.; Dayras, R.; De Cesare, N.; Demeyer, A.; Dore, D.; Frankland, J.D.; Galichet, E.; Gerlic, E.; Guinet, D.; Hudan, S.; Lautesse, P.; Lavaud, F.; Laville, J.L.; Lecolley, J.F.; Leduc, C.; Legrain, R.; Le Neindre, N.; Lopez, O.; Louvel, M.; Maskay, A.M.; Nalpas, L.; Normand, J.; Parlog, M.; Pawlowski, P.; Plagnol, E.; Rivet, M.F.; Rosato, E.; Saint-Laurent, F.; Tabacaru, G.; Tamain, B.; Tassan-Got, L.; Tirel, O.; Turzo, K.; Vigilante, M.; Volant, C.; Wieleczko, J.P.

    2001-01-01

    The excitation energy and angular momentum transferred to quasiprojectiles have been measured in the 129 Xe+ nat Sn collisions at bombarding energies between 25 and 50 MeV/nucleon. The excitation energy of quasiprojectiles has been determined from the kinetic energy of all decay products (calorimetry). It increases with the violence of the collision, approaching 10 MeV/nucleon in the most dissipative ones. The angular momentum has been deduced from the kinetic energies and angular distributions of the emitted light charged particles (p, d, t, 3 He and α). The (apparent) spin value decreases with the violence of the collision. Larger spin values are observed at the lowest bombarding energy. Data are compared with the predictions of dynamical and statistical models. They reproduce the data in a quantitative way indicating that large spin values are transferred to quasiprojectiles during the interaction. The results show that the one-body dissipation formalism still applies at intermediate bombarding energies and low-energy dissipations. With the increase of the energy, the data seem to be better described when the two-body interaction is accounted for

  17. Charged particle multiplicity distributions in Au-Au collisions at RHIC-BNL energies (BRAHMS Experiment)

    International Nuclear Information System (INIS)

    Argintaru, D.; Bearden, I.G.; Beavis, D.

    2002-01-01

    The BRAHMS Experiment (Broad RAnge Hadronic Magnetic Spectrometers) takes place at the Relativistic Heavy Ion Collider (RHIC) from Brookhaven National Laboratory and searches for a transition of matter into a new phase called quark-gluon plasma (QGP), a phase transition that appears in extreme conditions of nuclear matter densities and temperatures. Important signals for this transition are related to dependencies of the charged particle multiplicity distributions on the pseudorapidity range. The charged particle multiplicity distributions in Au-Au collisions at RHIC energies are obtained from the global detector measurements. These detectors are: - An array of Si strip detectors and scintillation tiles placed around the interaction region; they cover the range η < 2 in pseudorapidity, measuring the majority of charged particles; - Two systems of Cerenkov detectors (Beam-Beam Counters) placed both sides of the nominal interaction point at 220 cm and cover the range 3 < η < 4.3 in pseudorapidity. These detectors are used for vertex determination and supply a level zero trigger for the entire experiment; - Zero Degree Calorimeters placed at zero degree with respect to the beam axis, both sides of the vertex, measuring the spectator neutrons from the nuclear reactions. These detectors supplies information about the reaction centrality and could estimate the interaction vertex. The paper presents some results on charged particle multiplicities in different pseudorapidity ranges at different impact parameters. Interesting dependencies of the average charged particle multiplicities on the pseudorapidity range, impact parameters and total available energy in the centre of mass system. Some comparisons with the simulation codes predictions and theoretical model estimations are included, too. (authors)

  18. Factors affecting the energy resolution in alpha particle spectrometry with silicon diodes

    International Nuclear Information System (INIS)

    Camargo, Fabio de.

    2005-01-01

    In this work are presented the studies about the response of a multi-structure guard rings silicon diode for detection and spectrometry of alpha particles. This ion-implanted diode (Al/p + /n/n + /Al) was processed out of 300 μm thick, n type substrate with a resistivity of 3 kΩ·cm and an active area of 4 mm 2 . In order to use this diode as a detector, the bias voltage was applied on the n + side, the first guard ring was grounded and the electrical signals were readout from the p + side. These signals were directly sent to a tailor made preamplifier, based on the hybrid circuit A250 (Amptek), followed by a conventional nuclear electronic. The results obtained with this system for the direct detection of alpha particles from 241 Am showed an excellent response stability with a high detection efficiency (≅ 100 %). The performance of this diode for alpha particle spectrometry was studied and it was prioritized the influence of the polarization voltage, the electronic noise, the temperature and the source-diode distance on the energy resolution. The results showed that the major contribution for the deterioration of this parameter is due to the diode dead layer thickness (1 μm). However, even at room temperature, the energy resolution (FWHM = 18.8 keV) measured for the 5485.6 MeV alpha particles ( 241 Am) is comparable to those obtained with ordinary silicon barrier detectors frequently used for these particles spectrometry. (author)

  19. N-type doping of InGaN by high energy particle irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Yu, K.M. [Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley CA, 94720 (United States)

    2009-06-15

    This article reviews our extensive studies of the effects of native defects introduced by high energy particles on the electrical and optical properties of InGaN alloys. We show that the electronic properties of irradiated InGaN can be well described by the amphoteric defect model. Because of the extremely low position of the conduction band edge of InN the formation energy of native donor defects is very low in In-rich InGaN alloys. High energy particle irradiation of InN and In-rich InGaN, will therefore produce donor defects and result in more n-type materials. As the irradiation dose increases, the electron concentration increases until the Fermi energy E{sub F} approaches the Fermi stabilization energy E{sub FS}. At this point both donor and acceptor-type defects are formed at similar rates, and compensate each other, leading to stabilization of E{sub F} and a saturation of the electron concentration. Hence a large increase and then saturation in the Burstein-Moss shift of the optical absorption edge is also observed. Furthermore we also found that mobilities in the irradiated films can be well described by scattering from triply charged defects, providing strong evidence that native defects in InN are triple donors. The excellent agreement between the experimental results and predictions based on the ADM suggests that particle irradiation can be an effective and simple method to control the doping (electron concentration) in In-rich In{sub x}Ga{sub 1-x}N via native point defects. (copyright 2009 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  20. N-type doping of InGaN by high energy particle irradiation

    International Nuclear Information System (INIS)

    Yu, K.M.

    2009-01-01

    This article reviews our extensive studies of the effects of native defects introduced by high energy particles on the electrical and optical properties of InGaN alloys. We show that the electronic properties of irradiated InGaN can be well described by the amphoteric defect model. Because of the extremely low position of the conduction band edge of InN the formation energy of native donor defects is very low in In-rich InGaN alloys. High energy particle irradiation of InN and In-rich InGaN, will therefore produce donor defects and result in more n-type materials. As the irradiation dose increases, the electron concentration increases until the Fermi energy E F approaches the Fermi stabilization energy E FS . At this point both donor and acceptor-type defects are formed at similar rates, and compensate each other, leading to stabilization of E F and a saturation of the electron concentration. Hence a large increase and then saturation in the Burstein-Moss shift of the optical absorption edge is also observed. Furthermore we also found that mobilities in the irradiated films can be well described by scattering from triply charged defects, providing strong evidence that native defects in InN are triple donors. The excellent agreement between the experimental results and predictions based on the ADM suggests that particle irradiation can be an effective and simple method to control the doping (electron concentration) in In-rich In x Ga 1-x N via native point defects. (copyright 2009 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)