WorldWideScience

Sample records for range 220-570 mev

  1. THE ORIGIN OF THE COSMIC GAMMA-RAY BACKGROUND IN THE MeV RANGE

    Energy Technology Data Exchange (ETDEWEB)

    Ruiz-Lapuente, Pilar [Instituto de Física Fundamental, Consejo Superior de Investigaciones Científicas, c/. Serrano 121, E-28006, Madrid (Spain); The, Lih-Sin; Hartmann, Dieter H.; Ajello, Marco [Department of Physics and Astronomy, Clemson University, Clemson, SC 29634 (United States); Canal, Ramon [Institut de Ciències del Cosmos (UB-IEEC), c/. Martí i Franqués 1, E-08028, Barcelona (Spain); Röpke, Friedrich K.; Ohlmann, Sebastian T. [Institute of Theoretical Physics and Astrophysics, University of Würzburg, D-97074, Würzburg (Germany); Hillebrandt, Wolfgang [Max-Planck-Institut für Astrophysik, Karl-Schwarzschild-Str. 1, D-85748 Garching bei München (Germany)

    2016-04-01

    There has been much debate about the origin of the diffuse γ-ray background in the MeV range. At lower energies, AGNs and Seyfert galaxies can explain the background, but not above ≃0.3 MeV. Beyond ∼10 MeV blazars appear to account for the flux observed. That leaves an unexplained gap for which different candidates have been proposed, including annihilations of WIMPS. One candidate is Type Ia supernovae (SNe Ia). Early studies concluded that they were able to account for the γ-ray background in the gap, while later work attributed a significantly lower contribution to them. All those estimates were based on SN Ia explosion models that did not reflect the full 3D hydrodynamics of SN Ia explosions. In addition, new measurements obtained since 2010 have provided new, direct estimates of high-z SN Ia rates beyond z ∼ 2. We take into account these new advances to see the predicted contribution to the gamma-ray background. We use here a wide variety of explosion models and a plethora of new measurements of SN Ia rates. SNe Ia still fall short of the observed background. Only for a fit, which would imply ∼150% systematic error in detecting SN Ia events, do the theoretical predictions approach the observed fluxes. This fit is, however, at odds at the highest redshifts with recent SN Ia rate estimates. Other astrophysical sources such as flat-spectrum radio quasars do match the observed flux levels in the MeV regime, while SNe Ia make up to 30%–50% of the observed flux.

  2. Personal dose equivalent conversion coefficients for neutron fluence over the energy range of 20-250 MeV.

    Science.gov (United States)

    Olsher, R H; McLean, T D; Justus, A L; Devine, R T; Gadd, M S

    2010-03-01

    Monte Carlo simulations were performed to extend existing neutron personal dose equivalent fluence-to-dose conversion coefficients to an energy of 250 MeV. Presently, conversion coefficients, H(p,slab)(10,alpha)/Phi, are given by ICRP-74 and ICRU-57 for a range of angles of radiation incidence (alpha = 0, 15, 30, 45, 60 and 75 degrees ) in the energy range from thermal to 20 MeV. Standard practice has been to base operational dose quantity calculations 20 MeV. Both light and heavy ions (HIs) (carbon, nitrogen and oxygen recoil nuclei) were transported down to a lower energy limit (1 keV for light ions and 5 MeV for HIs). Track energy below the limit was assumed to be locally deposited. For neutron tracks slab phantom.

  3. Personal dose equivalent conversion coefficients for neutron fluence over the energy range of 20 to 250 MeV

    Energy Technology Data Exchange (ETDEWEB)

    Mclean, Thomas D [Los Alamos National Laboratory; Justus, Alan L [Los Alamos National Laboratory; Gadd, S Milan [Los Alamos National Laboratory; Olsher, Richard H [RP-2; Devine, Robert T [RP-2

    2009-01-01

    Monte Carlo simulations were performed to extend existing neutron personal dose equivalent fluence-to-dose conversion coefficients to an energy of 250 MeV. Presently, conversion coefficients, H(p,slab)(10,alpha)/Phi, are given by ICRP-74 and ICRU-57 for a range of angles of radiation incidence (alpha = 0, 15, 30, 45, 60 and 75 degrees ) in the energy range from thermal to 20 MeV. Standard practice has been to base operational dose quantity calculations <20 MeV on the kerma approximation, which assumes that charged particle secondaries are locally deposited, or at least that charged particle equilibrium exists within the tally cell volume. However, with increasing neutron energy the kerma approximation may no longer be valid for some energetic secondaries such as protons. The Los Alamos Monte Carlo radiation transport code MCNPX was used for all absorbed dose calculations. Transport models and collision-based energy deposition tallies were used for neutron energies >20 MeV. Both light and heavy ions (HIs) (carbon, nitrogen and oxygen recoil nuclei) were transported down to a lower energy limit (1 keV for light ions and 5 MeV for HIs). Track energy below the limit was assumed to be locally deposited. For neutron tracks <20 MeV, kerma factors were used to obtain absorbed dose. Results are presented for a discrete set of angles of incidence on an ICRU tissue slab phantom.

  4. Stopping power of liquid water for carbon ions in the energy range between 1 MeV and 6 MeV.

    Science.gov (United States)

    Rahm, J M; Baek, W Y; Rabus, H; Hofsäss, H

    2014-07-21

    The stopping power of liquid water was measured for the first time for carbon ions in the energy range between 1 and 6 MeV using the inverted Doppler shift attenuation method. The feasibility study carried out within the scope of the present work shows that this method is well suited for the quantification of the controversial condensed phased effect in the stopping power for heavy ions in the intermediate energy range. The preliminary results of this work indicate that the stopping power of water for carbon ions with energies prevailing in the Bragg-peak region is significantly lower than that of water vapor. In view of the relatively high uncertainty of the present results, a new experiment with uncertainties less than the predicted difference between the stopping powers of both water phases is planned.

  5. Dual sightline measurements of MeV range deuterons with neutron and gamma-ray spectroscopy at JET

    DEFF Research Database (Denmark)

    Eriksson, J.; Nocente, M.; Binda, F.

    2015-01-01

    Observations made in a JET experiment aimed at accelerating deuterons to the MeV range by third harmonic radio-frequency (RF) heating coupled into a deuterium beam are reported. Measurements are based on a set of advanced neutron and gamma-ray spectrometers that, for the first time, observe the p...

  6. Analyses of Alpha-Alpha Elastic Scattering Data in the Energy Range 140 - 280 MeV

    Energy Technology Data Exchange (ETDEWEB)

    Shehadeh, Zuhair F. [Taif University, Taif (Saudi Arabia)

    2017-01-15

    The differential and the reaction cross-sections for 4He-4He elastic scattering data have been nicely obtained at four energies ranging from 140 MeV to 280 MeV (lab system), namely, 140, 160, 198 and 280 MeV, by using a new optical potential with a short-range repulsive core. The treatment has been handled relativistically as υ/c > 0.25 for the two lower energies and υ/c > 0.31 for the two higher ones. In addition to explaining the elastic angular distributions, the adopted potentials accounted for the structure that may exist at angles close to 90◦ , especially for the 198 and the 280-MeV incident energies. No renormalization has been used, and all our potential parameters are new. The necessity of including a short-range repulsive potential term in our real nuclear potential part has been demonstrated. Our results contribute to solving a long-standing problem concerning the nature of the alpha-alpha potential. This is very beneficial in explaining unknown alpha-nucleus and nucleus-nucleus relativistic reactions by using the cluster formalism.

  7. A measurement of auroral electrons in the 1–10 MeV range

    NARCIS (Netherlands)

    Gils, J.N. van; Beek, H.F. van; Fetter, L.D. de; Hendrickx, R.V.

    Particle fluxes have been measured by means of shielded Geiger-Müller telescopes mounted m a rocket, which was launched from ESRANGE(Kiruna) into a diffuse aurora. The analysis of the dependence of the counting rates on altitude indicates that a weak flux of energetic electrons, 1–10 MeV, has been

  8. Calibration of imaging plate detectors to mono-energetic protons in the range 1-200 MeV

    Science.gov (United States)

    Rabhi, N.; Batani, D.; Boutoux, G.; Ducret, J.-E.; Jakubowska, K.; Lantuejoul-Thfoin, I.; Nauraye, C.; Patriarca, A.; Saïd, A.; Semsoum, A.; Serani, L.; Thomas, B.; Vauzour, B.

    2017-11-01

    Responses of Fuji Imaging Plates (IPs) to proton have been measured in the range 1-200 MeV. Mono-energetic protons were produced with the 15 MV ALTO-Tandem accelerator of the Institute of Nuclear Physics (Orsay, France) and, at higher energies, with the 200-MeV isochronous cyclotron of the Institut Curie—Centre de Protonthérapie d'Orsay (Orsay, France). The experimental setups are described and the measured photo-stimulated luminescence responses for MS, SR, and TR IPs are presented and compared to existing data. For the interpretation of the results, a sensitivity model based on the Monte Carlo GEANT4 code has been developed. It enables the calculation of the response functions in a large energy range, from 0.1 to 200 MeV. Finally, we show that our model reproduces accurately the response of more complex detectors, i.e., stack of high-Z filters and IPs, which could be of great interest for diagnostics of Petawatt laser accelerated particles.

  9. Activation cross-sections of proton induced reactions on vanadium in the 37-65 MeV energy range

    OpenAIRE

    Ditrói, F.; Tárkányi, F.; Takács, S.; Hermanne, A.

    2016-01-01

    Experimental excitation functions for proton induced reactions on natural vanadium in the 37-65 MeV energy range were measured with the activation method using a stacked foil irradiation technique. By using high resolution gamma spectrometry cross-section data for the production of $^{51,48}$Cr, $^{48}$V, $^{48,47,46,44m,44g,43}$Sc and $^{43,42}$K were determined. Comparisons with the earlier published data are presented and results predicted by different theoretical codes (EMPIRE and TALYS) ...

  10. Activation cross-sections of proton induced reactions on vanadium in the 37–65 MeV energy range

    Energy Technology Data Exchange (ETDEWEB)

    Ditrói, F., E-mail: ditroi@atomki.hu [Institute for Nuclear Research, Hungarian Academy of Sciences (ATOMKI), Debrecen (Hungary); Tárkányi, F.; Takács, S. [Institute for Nuclear Research, Hungarian Academy of Sciences (ATOMKI), Debrecen (Hungary); Hermanne, A. [Cyclotron Laboratory, Vrije Universiteit Brussel (VUB), Brussels (Belgium)

    2016-08-15

    Highlights: • Proton induced nuclear reactions on natural vanadium in the 35–65 MeV range. • Stacked foil irradiation technique. • Comparison of results with the EMPIRE and TENDL-2015 calculations. • Application of results in thin layer activation is demonstrated. - Abstract: Experimental excitation functions for proton induced reactions on natural vanadium in the 37–65 MeV energy range were measured with the activation method using a stacked foil irradiation technique. By using high resolution gamma spectrometry cross-section data for the production of {sup 51,48}Cr, {sup 48}V, {sup 48,47,46,44m,44g,43}Sc and {sup 43,42}K were determined. Comparisons with the earlier published data are presented and results predicted by different theoretical codes (EMPIRE and TALYS) are included. Thick target yields were calculated from a fit to our experimental excitation curves and compared with the earlier experimental yield data. Depth distribution curves to be used for thin layer activation (TLA) are also presented.

  11. Activation cross sections of deuteron induced reactions on niobium in the 30–50 MeV energy range

    Energy Technology Data Exchange (ETDEWEB)

    Ditrói, F., E-mail: ditroi@atomki.hu [Institute for Nuclear Research, Hungarian, Acad. Sci., Debrecen (Hungary); Tárkányi, F.; Takács, S. [Institute for Nuclear Research, Hungarian, Acad. Sci., Debrecen (Hungary); Hermanne, A. [Cyclotron Laboratory, Vrije Universitet, Brussel (Belgium); Ignatyuk, A.V. [Institute for Physics and Power Engineering (IPPE), Obninsk (Russian Federation)

    2016-04-15

    Highlights: • Deuteron induced nuclear reactions on natural niobium up to 50 MeV. • Stacked foil irradiation technique. • Comparison of results with the ALICE-D, EMPIRE-D and TENDL-2015 calculations. • Application of radioisotopes in medicine and industry. - Abstract: Activation cross-sections of deuterons induced reactions on Nb targets were determined with the aim of different applications and comparison with theoretical models. We present the experimental excitation functions of {sup 93}Nb(d,x){sup 93m,90}Mo, {sup 92m,91m,90}Nb, {sup 89,88}Zr and {sup 88,87m,87g}Y in the energy range of 30–50 MeV. The results were compared with earlier measurements and with the cross-sections calculated by means of the theoretical model codes ALICE-D, EMPIRE-D and TALYS (on-line TENDL-2014 and TENDL-2015 libraries). Possible applications of the radioisotopes are discussed in detail.

  12. Neutron-induced fission cross sections of 233U and 243Am in the energy range 0.5 Mev En 20 MeV @ n_TOF

    CERN Document Server

    Belloni, F; Milazzo, P M; Calviani, M; Colonna, N; Mastinu, P; Abbondanno, U; Aerts, G; Álvarez, H; Álvarez-Velarde, F; Andriamonje, S; Andrzejewski, J; Assimakopoulos, P; Audouin, L; Badurek, G; Baumann, P; Becvár, F; Berthoumieux, E; Calviño, F; Cano-Ott, D; Capote, R; Carrapiço, C; Cennini, P; Chepel, V; Chiaveri, E; Cortes, G; Couture, A; Cox, J; Dahlfors, M; David, S; Dillmann, I; Domingo-Pardo, C; Dridi, W; Duran, I; Eleftheriadis, C; Embid-Segura, M; Ferrant, L; Ferrari, A; Ferreira-Marques, R; Fujii, K; Furman, W; Goncalves, I; González-Romero, E; Gramegna, F; Guerrero, C; Gunsing, F; Haas, B; Haight, R; Heil, M; Herrera-Martinez, A; Igashira, M; Jericha, E; Käppeler, F; Kadi, Y; Karadimos, D; Karamanis, D; Kerveno, M; Koehler, P; Kossionides, E; Krticka, M; Lampoudis, C; Leeb, H; Lindote, A; Lopes, I; Lozano, M; Lukic, S; Marganiec, J; Marrone, S; Martínez, T; Massimi, C; Mengoni, A; Moreau, C; Mosconi, M; Neves, F; Oberhummer, H; O'Brien, S; Pancin, J; Papachristodoulou, C; Papadopoulos, C; Paradela, C; Patronis, N; Pavlik, A; Pavlopoulos, P; Perrot, L; Pigni, M T; Plag, R; Plompen, A; Plukis, A; Poch, A; Praena, J; Pretel, C; Quesada, J; Rauscher, T; Reifarth, R; Rubbia, C; Rudolf, G; Rullhusen, P; Salgado, J; Santos, C; Sarchiapone, L; Savvidis, I; Stephan, C; Tagliente, G; Tain, J L; Tassan-Got, L; Tavora, L; Terlizzi, R; Vannini, G; Vazl, P; Ventura, A; Villamarin, D; Vincente, M C; Vlachoudis, V; Vlastou, R; Voss, F; Walter, S; Wiescher, M; Wisshak, K

    2011-01-01

    Neutron-induced fission cross-sections of actinides have been recently measured at the neutron time of flight facility n_TOF at CERN in the frame of a research project involving isotopes relevant for nuclear astrophysics and nuclear technologies. Fission fragments are detected by a gas counter with good discrimination between nuclear fission products and background events. Neutron-induced fission cross-sections of 233U and 243Am were determined relative to 235U. The present paper reports the results obtained at neutron energies between 0.5 and 20 MeV.

  13. High order magnetic optics for high dynamic range proton radiography at a kinetic energy of 800 MeV

    Energy Technology Data Exchange (ETDEWEB)

    Sjue, S. K. L., E-mail: sjue@lanl.gov; Mariam, F. G.; Merrill, F. E.; Morris, C. L.; Saunders, A. [Physics Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States)

    2016-01-15

    Flash radiography with 800 MeV kinetic energy protons at Los Alamos National Laboratory is an important experimental tool for investigations of dynamic material behavior driven by high explosives or pulsed power. The extraction of quantitative information about density fields in a dynamic experiment from proton generated images requires a high fidelity model of the proton imaging process. It is shown that accurate calculations of the transmission through the magnetic lens system require terms beyond second order for protons far from the tune energy. The approach used integrates the correlated multiple Coulomb scattering distribution simultaneously over the collimator and the image plane. Comparison with a series of static calibration images demonstrates the model’s accurate reproduction of both the transmission and blur over a wide range of tune energies in an inverse identity lens that consists of four quadrupole electromagnets.

  14. Andromede project: Surface analysis and modification with probes from hydrogen to nano-particles in the MeV energy range

    Energy Technology Data Exchange (ETDEWEB)

    Eller, Michael J.; Cottereau, Evelyne [Institut de Physique Nucléaire d’Orsay, UMR8608, CNRS/IN2P3, Université Paris-Sud 11, F-91406 Orsay (France); Rasser, Bernard; Verzeroli, Elodie [Orsay Physics, ZAC Saint Charles, 95 Av des Monts Auréliens, 13710 Fuveau (France); Agnus, Benoit; Gaubert, Gabriel; Donzel, Xavier [Pantechnik SA, 13 rue de la Résistance, 14400 Bayeux (France); Delobbe, Anne [Orsay Physics, ZAC Saint Charles, 95 Av des Monts Auréliens, 13710 Fuveau (France); Della-Negra, Serge, E-mail: dellaneg@ipno.in2p3.fr [Institut de Physique Nucléaire d’Orsay, UMR8608, CNRS/IN2P3, Université Paris-Sud 11, F-91406 Orsay (France)

    2015-12-15

    The Andromede project is the center of a multi-disciplinary team which will build a new instrument for surface modification and analysis using the impact of probes from hydrogen to nano-particles (Au{sub 400}{sup +4}) in the MeV range. For this new instrument a series of atomic, polyatomic, molecular and nano-particle ion beams will be delivered using two ion sources in tandem, a liquid metal ion source and an electron cyclotron resonance source. The delivered ion beams will be accelerated to high energy with a 4 MeV van de Graaff type accelerator. By using a suite of probes in the MeV energy range, ion beam analysis techniques, MeV atomic and cluster secondary ion mass spectrometry can all be performed in one location. A key feature of the instrument is its ability to produce an intense beam for injection into the accelerator. The commissioning of the two sources shows that intense beams from atomic ions to nano-particles can be delivered for subsequent acceleration. The calculations and measurements for the two sources are presented.

  15. Magnetoresistance studies of MeV ranged {sup 1}H{sup +} and {sup 12}C{sup +} ion irradiated HOPG flakes

    Energy Technology Data Exchange (ETDEWEB)

    Shukla, Neeraj; Bose, Saurabh K.; Choudhary, Shyam K.; Pandey, Himanshu; Sarkar, Mihir; Banerji, Nobin; Gupta, Anjan K. [Department of Physics, Indian Institute of Technology Kanpur, Kanpur 208016 (India); Verma, Harish C., E-mail: hcverma@iitk.ac.in [Department of Physics, Indian Institute of Technology Kanpur, Kanpur 208016 (India)

    2012-11-15

    2 MeV protons and 1 MeV carbon ions are bombarded on highly oriented pyrolytic graphite (HOPG) samples and their electronic transport measurements are carried out in the presence of magnetic field. The Magneto-Resistance (MR) measurements show measurable hysteresis in the resistance value after ion beam irradiation for the in-plane magnetic field direction as well as for the out-of-plane field direction. The MR depends on the thickness of the flake and the method of its separation from the bulk HOPG. The results substantiate that the ferromagnetic coupling between the magnetic moments at the vacancy defect sites in HOPG sensitively depends on the average defect separation. The average defect separation range of 1.7-0.5 nm allows only a part of the 40 {mu}m thick proton beam irradiated sample to go for ferromagnetic ordering. Similar conclusions are drawn from carbon ion irradiated HOPG flake. The irradiation increases the resistance of the flake as well. - Highlights: Black-Right-Pointing-Pointer Magnetoresistance (MR) studies of MeV ranged H and C ion irradiated Graphite. Black-Right-Pointing-Pointer Hysteresis in the MR data and lowering of MR post ion irradiation. Black-Right-Pointing-Pointer Large MR value in the case of thinner sample for B field along the c axis. Black-Right-Pointing-Pointer MR results substantiate ferromagnetic coupling between ion induced defects. Black-Right-Pointing-Pointer The defect separation range has a preferred window for ferromagnetic coupling.

  16. Extension of the energy range of experimental activation cross-sections data of deuteron induced nuclear reactions on indium up to 50MeV.

    Science.gov (United States)

    Tárkányi, F; Ditrói, F; Takács, S; Hermanne, A; Ignatyuk, A V

    2015-11-01

    The energy range of our earlier measured activation cross-sections data of longer-lived products of deuteron induced nuclear reactions on indium were extended from 40MeV up to 50MeV. The traditional stacked foil irradiation technique and non-destructive gamma spectrometry were used. No experimental data were found in literature for this higher energy range. Experimental cross-sections for the formation of the radionuclides (113,110)Sn, (116m,115m,114m,113m,111,110g,109)In and (115)Cd are reported in the 37-50MeV energy range, for production of (110)Sn and (110g,109)In these are the first measurements ever. The experimental data were compared with the results of cross section calculations of the ALICE and EMPIRE nuclear model codes and of the TALYS 1.6 nuclear model code as listed in the on-line library TENDL-2014. Copyright © 2015 Elsevier Ltd. All rights reserved.

  17. Proton inelastic mean free path in a group of bioorganic compounds and water in 0.05-10 MeV range - Including higher-order corrections

    Energy Technology Data Exchange (ETDEWEB)

    Tan Zhenyu, E-mail: tzy@sdu.edu.c [School of Electrical Engineering, Shandong University, Jinan 250061, Shandong (China); Xia Yueyuan; Zhao Mingwen; Liu Xiangdong [School of Physics, Shandong University, Jinan 250100, Shandong (China)

    2010-07-15

    The systematic calculations of the inelastic mean free paths (MFP) of 0.05-10 MeV protons in a group of eleven important bioorganic compounds, i.e. DNA, five bases, three fatty acids, cellulose and {beta}-carotene, have been performed. The expressions for the calculations are derived from the Ashley's optical-data model and from the higher-order correction terms in stopping power calculations. Especially, the Bloch correction for the inelastic MFP is proposed empirically in this work. The inelastic MFPs for energetic protons in water are also evaluated and compared with other theoretical calculations. The proton inelastic MFPs for these 11 bioorganic compounds in the energy range from 0.05 to 10 MeV are presented here for the first time, and might be useful for studies of various radiation effects in these materials.

  18. Experimental studies on the proton-induced activation reactions of molybdenum in the energy range 22-67 MeV.

    Science.gov (United States)

    Uddin, M S; Hagiwara, M; Tarkanyi, F; Ditroi, F; Baba, M

    2004-06-01

    The production cross-sections of (99,93m)Mo, (96,95,95m,94)Tc, (96,95,92m,90)Nb, (89,88,86)Zr and (88,87,86)Y radionuclides for proton-induced reactions on molybdenum were measured with molybdenum targets of natural isotopic composition using a stacked-foil activation technique in the energy range 22-67 MeV. The thick target integral yields were also deduced for each reaction using the measured cross-sections from the respective threshold up to 67 MeV. The results have given new data for all of the investigated radionuclides. The results of the present experiment showed excellent agreement with the earlier reported data in the lower energy region.

  19. Measurement of cross sections for the scattering of neutrons in the energy range from 2 MeV to 4 MeV with the {sup 15}N(p,n) reaction as neutron source; Messung von Wirkungsquerschnitten fuer die Streuung von Neutronen im Energiebereich von 2 MeV bis 4 MeV mit der {sup 15}N(p,n)-Reaktion als Neutronenquelle

    Energy Technology Data Exchange (ETDEWEB)

    Poenitz, Erik

    2010-04-26

    In future nuclear facilities, the materials lead and bismuth can play a more important role than in today's nuclear reactors. Reliable cross section data are required for the design of those facilities. In particular the neutron transport in the lead spallation target of an Accelerator-Driven Subcritical Reactor strongly depends on the inelastic neutron scattering cross sections in the energy region from 0.5 MeV to 6 MeV. In the recent 20 years, elastic and inelastic neutron scattering cross sections were measured with high precision for a variety of elements at the PTB time-of-flight spectrometer. The D(d,n) reaction was primarily used for the production of neutrons. Because of the Q value of the reaction and the available deuteron energies, neutrons in the energy range from 6 MeV to 16 MeV can be produced. For the cross section measurement at lower energies, however, another neutron producing reaction is required. The {sup 15}N(p,n){sup 15}O reaction was chosen, as it allows the production of monoenergetic neutrons with up to 5.7MeV energy. In this work, the {sup 15}N(p,n) reaction was studied with focus on the suitability as a source for monoenergetic neutrons in scattering experiments. This includes the measurement of differential cross sections for the neutron producing reaction and the choice of optimum target conditions. Differential elastic and inelastic neutron scattering cross sections were measured for lead at four energies in the region from 2 MeV to 4 MeV incident neutron energy using the time-of-flight technique. A lead sample with natural isotopic composition was used. NE213 liquid scintillation detectors with well-known detection efficiencies were used for the detection of the scattered neutrons. Angle-integrated cross sections were determined by a Legendre polynomial expansion using least-squares methods. Additionally, measurements were carried out for isotopically pure {sup 209}Bi and {sup 181}Ta samples at 4 MeV incident neutron energy

  20. Secondary neutron spectrum from 250-MeV passively scattered proton therapy: Measurement with an extended-range Bonner sphere system

    Energy Technology Data Exchange (ETDEWEB)

    Howell, Rebecca M., E-mail: rhowell@mdanderson.org [Department of Radiation Physics, The University of Texas MD Anderson Cancer Center, Houston, Texas 77030 (United States); Burgett, E. A. [Department of Nuclear Engineering, Idaho State University, Pocatello, Idaho 83201 (United States)

    2014-09-15

    Purpose: Secondary neutrons are an unavoidable consequence of proton therapy. While the neutron dose is low compared to the primary proton dose, its presence and contribution to the patient dose is nonetheless important. The most detailed information on neutrons includes an evaluation of the neutron spectrum. However, the vast majority of the literature that has reported secondary neutron spectra in proton therapy is based on computational methods rather than measurements. This is largely due to the inherent limitations in the majority of neutron detectors, which are either not suitable for spectral measurements or have limited response at energies greater than 20 MeV. Therefore, the primary objective of the present study was to measure a secondary neutron spectrum from a proton therapy beam using a spectrometer that is sensitive to neutron energies over the entire neutron energy spectrum. Methods: The authors measured the secondary neutron spectrum from a 250-MeV passively scattered proton beam in air at a distance of 100 cm laterally from isocenter using an extended-range Bonner sphere (ERBS) measurement system. Ambient dose equivalent H*(10) was calculated using measured fluence and fluence-to-ambient dose equivalent conversion coefficients. Results: The neutron fluence spectrum had a high-energy direct neutron peak, an evaporation peak, a thermal peak, and an intermediate energy continuum between the thermal and evaporation peaks. The H*(10) was dominated by the neutrons in the evaporation peak because of both their high abundance and the large quality conversion coefficients in that energy interval. The H*(10) 100 cm laterally from isocenter was 1.6 mSv per proton Gy (to isocenter). Approximately 35% of the dose equivalent was from neutrons with energies ≥20 MeV. Conclusions: The authors measured a neutron spectrum for external neutrons generated by a 250-MeV proton beam using an ERBS measurement system that was sensitive to neutrons over the entire

  1. Secondary neutron spectrum from 250-MeV passively scattered proton therapy: measurement with an extended-range Bonner sphere system.

    Science.gov (United States)

    Howell, Rebecca M; Burgett, E A

    2014-09-01

    Secondary neutrons are an unavoidable consequence of proton therapy. While the neutron dose is low compared to the primary proton dose, its presence and contribution to the patient dose is nonetheless important. The most detailed information on neutrons includes an evaluation of the neutron spectrum. However, the vast majority of the literature that has reported secondary neutron spectra in proton therapy is based on computational methods rather than measurements. This is largely due to the inherent limitations in the majority of neutron detectors, which are either not suitable for spectral measurements or have limited response at energies greater than 20 MeV. Therefore, the primary objective of the present study was to measure a secondary neutron spectrum from a proton therapy beam using a spectrometer that is sensitive to neutron energies over the entire neutron energy spectrum. The authors measured the secondary neutron spectrum from a 250-MeV passively scattered proton beam in air at a distance of 100 cm laterally from isocenter using an extended-range Bonner sphere (ERBS) measurement system. Ambient dose equivalent H*(10) was calculated using measured fluence and fluence-to-ambient dose equivalent conversion coefficients. The neutron fluence spectrum had a high-energy direct neutron peak, an evaporation peak, a thermal peak, and an intermediate energy continuum between the thermal and evaporation peaks. The H*(10) was dominated by the neutrons in the evaporation peak because of both their high abundance and the large quality conversion coefficients in that energy interval. The H*(10) 100 cm laterally from isocenter was 1.6 mSv per proton Gy (to isocenter). Approximately 35% of the dose equivalent was from neutrons with energies ≥20 MeV. The authors measured a neutron spectrum for external neutrons generated by a 250-MeV proton beam using an ERBS measurement system that was sensitive to neutrons over the entire energy range being measured, i.e., thermal to

  2. Curves for the response of a Ge(Li) detector to gamma rays in the energy range up to 11 MeV

    DEFF Research Database (Denmark)

    Kopecký, J.; Ratyński, W.; Warming, Inge Elisabeth

    1967-01-01

    The response function of a Ge(Li) coaxial detector with a sensitive volume of 17 cm3 for gamma rays of energies ranging from 2.23 to 10.83 MeV has been determined. The measurements were carried out with an experimental set-up using the neutron beam from the DR 3 reactor ar Risö and the (n, γ......) reaction as gamma-ray source. The important features of the spectra are discussed, and the double-escape peak efficiency is determined....

  3. Measurement of the stopping power of water for carbon ions in the energy range of 1 MeV-6 MeV using the inverted Doppler-shift attenuation method

    Energy Technology Data Exchange (ETDEWEB)

    Rahm, Johannes Martin

    2016-10-31

    Cancer therapy using carbon ions has gained increasing interest in the last decade due to its advantageous dose distributions. For the dosimetry and treatment planning, the accurate knowledge of the stopping power of water for carbon ions is of crucial importance. In the high energy region, the stopping power can be calculated rather accurately by means of the Bethe-Bloch formula. In the case of projectile velocities comparable to those of the valence electrons of the target, these calculations are subject to large uncertainties. There exist no experimental data for the stopping power of water for projectile energies prevailing in the so-called Bragg peak region. The currently available stopping power data for water are derived from measurements in water vapour or D{sub 2}O ice and, hence, neglect the dependence on the state of aggregation. The stopping power of water for charged particles is of high interest not only for practical applications but also to consider how physical and chemical state of the target influence the collisional energy transfer. For the measurement of the stopping power of water, the inverted Doppler-shift attenuation method was used in this work. This method has the advantage that the projectile itself is not needed to be detected and can be slowed down entirely in the target. In this method, the stopping power is determined from the Doppler-shift of the gamma-quanta emitted by projectiles during their slow down. This experiment can be performed at atmospheric pressure and consequently, the stopping power of water can be measured in its real physiological condition. In this work, the stopping power of water for carbon ions was measured for the first time in the energy range between 1 MeV and 6 MeV covering the kinetic energies of carbon ions in the Bragg peak region. The experimental method is presented in detail along with the design of the apparatus and of the data acquisition system. A comprehensive analysis of instrumental effects

  4. Response functions of Fuji imaging plates to monoenergetic protons in the energy range 0.6-3.2 MeV.

    Science.gov (United States)

    Bonnet, T; Comet, M; Denis-Petit, D; Gobet, F; Hannachi, F; Tarisien, M; Versteegen, M; Aleonard, M M

    2013-01-01

    We have measured the responses of Fuji MS, SR, and TR imaging plates (IPs) to protons with energies ranging from 0.6 to 3.2 MeV. Monoenergetic protons were produced with the 3.5 MV AIFIRA (Applications Interdisciplinaires de Faisceaux d'Ions en Région Aquitaine) accelerator at the Centre d'Etudes Nucléaires de Bordeaux Gradignan (CENBG). The IPs were irradiated with protons backscattered off a tantalum target. We present the photo-stimulated luminescence response of the IPs together with the fading measurements for these IPs. A method is applied to allow correction of fading effects for variable proton irradiation duration. Using the IP fading corrections, a model of the IP response function to protons was developed. The model enables extrapolation of the IP response to protons up to proton energies of 10 MeV. Our work is finally compared to previous works conducted on Fuji TR IP response to protons.

  5. Phase shift analysis of {sup 12}C+{sup 12}C elastic scattering in the range E{sub lab} = 240 to 2400 MeV

    Energy Technology Data Exchange (ETDEWEB)

    Cha, Moon Hoe [Kangwon National University, Chunchon (Korea, Republic of)

    2006-10-15

    A phase shift analysis for the {sup 12}C+{sup 12}C system in the range E{sub lab} = 240 to 2400 MeV is performed by using the parametrized phase shift model. The diffractive oscillatory structures observed at forward angles are explained due to the strong interference between the near- and the far-side scattering amplitudes. The negative minima in the deflection curves occurring at angles {theta}{sub nucl} =- 49.92 .deg. {approx} -0.51 .deg. corresponding to energies E{sub lab} = 240 {approx} 2400 MeV, respectively, are shown to indicate the presences of nuclear rainbows. The partial reaction cross-sections are found to increase linearly up to some peak values and thereafter to decrease quadratically to zero. The peak values of partial reaction cross-section are shown to become smaller as the incident energy increases. Since the strong absorption radius becomes smaller as the incident energy decreases, the nuclear density distributions of the {sup 12}C+{sup 12}C system at higher energies are shown to have more overlaps than those at lower energies.

  6. The e-ASTROGAM mission: Exploring the extreme Universe with gamma rays in the MeV – GeV range

    DEFF Research Database (Denmark)

    De Angelis, A.; Tatischeff, V.; Tavani, M.

    2017-01-01

    e-ASTROGAM (‘enhanced ASTROGAM’) is a breakthrough Observatory space mission, with a detector composed by a Silicon tracker, a calorimeter, and an anticoincidence system, dedicated to the study of the non-thermal Universe in the photon energy range from 0.3 MeV to 3 GeV – the lower energy limit c...... evolution of our Galaxy. The mission will provide unique data of significant interest to a broad astronomical community, complementary to powerful observatories such as LIGO-Virgo-GEO600-KAGRA, SKA, ALMA, E-ELT, TMT, LSST, JWST, Athena, CTA, IceCube, KM3NeT, and the promise of eLISA....

  7. Measurements of double differential charged particle emission cross sections and development of a wide range charged particles spectrometer for ten`s MeV neutrons

    Energy Technology Data Exchange (ETDEWEB)

    Nauchi, Yasushi; Baba, Mamoru; Kiyosumi, Takehide [Tohoku Univ., Sendai (Japan). Faculty of Engineering] [and others

    1997-03-01

    We measured (n,xp), (n,xd) cross sections of C and Al for En=64.3 MeV neutrons at the {sup 7}Li(p,n) neutron sources facility at TIARA (Takasaki Establishment, JAERI) by using a conventional SSD-NaI telescope placed in the air. They show characteristic energy and angular dependence in high energy regions. In order to extend the measurements to low energy protons and {alpha} particles, a new spectrometer consisting of low pressure gas counters and BaF{sub 2} scintillators is now under development. A low threshold for low energy {alpha} particles will be achieved by using the gas counters. The particle identification over a wide energy range will be achieved by combining the {Delta}E-E method for low energy particles with the pulse shape discrimination (PSD) method of BaF{sub 2} for high energy particles. (author)

  8. The cross section functions for neutron induced reactions with Rhenium in the energy range 13.0-19.5 MeV

    Science.gov (United States)

    Jovančević, N.; Daraban, L.; Stroh, H.; Oberstedt, S.; Hult, M.; Bonaldi, C.; Geerts, W.; Hambsch, F.-J.; Lutter, G.; Marissens, G.; Vidali, M.

    2017-09-01

    The technique for measuring neutron activation cross-sections using wide energy neutron beams (NAXSUN) was recently developed at JRC-Geel . This method is based on the detection of the gamma activity induced by the activation of the samples in different but overlapping neutron fields and following an unfolding procedure. In the present work, measurements of the cross-section functions by the NAXSUN technique for the (n,a), (n,2n), (n,p) and (n,3n) reactions on rhenium isotopes 185Re and 187Re were performed. The results are the first experimental data for the mentioned reaction cross-sections in the energy range 13.0-19.5 MeV. The obtained data are of interest for possible applications of Re in nuclear technology and medicine.

  9. Measurement of activation cross-section of long-lived products in deuteron induced nuclear reactions on palladium in the 30-50MeV energy range.

    Science.gov (United States)

    Ditrói, F; Tárkányi, F; Takács, S; Hermanne, A; Ignatyuk, A V

    2017-10-01

    Excitation functions were measured in the 31-49.2MeV energy range for the natPd(d,xn)111,110m,106m,105,104g,103Ag, natPd(d,x) 111m,109,101,100Pd, natPd(d,x), 105,102m,102g,101m,101g,100,99m,99gRh and natPd(d,x)103,97Ru nuclear reactions by using the stacked foil irradiation technique. The experimental results are compared with our previous results and with the theoretical predictions calculated with the ALICE-D, EMPIRE-D and TALYS (TENDL libraries) codes. Copyright © 2017 Elsevier Ltd. All rights reserved.

  10. Activation cross-sections of proton induced nuclear reactions on thulium in the 20-45 MeV energy range.

    Science.gov (United States)

    Tárkányi, F; Hermanne, A; Takács, S; Ditrói, F; Spahn, I; Ignatyuk, A V

    2012-01-01

    Cross-sections of proton induced nuclear reactions on (169)Tm were measured in the 20-45MeV energy range using the standard stacked-foil irradiation technique and high resolution gamma-ray spectroscopy. Experimental cross-sections and derived integral yields are reported for the production of (169,167,166)Yb and (168,167,166)Tm radioisotopes. The experimental data are analysed and compared to results of the earlier measurements and the theoretical model codes ALICE-IPPE, EMPIRE and TALYS. Application of the new cross-sections to the production of the (167)Tm medical radioisotope is discussed. Copyright © 2011 Elsevier Ltd. All rights reserved.

  11. The e-ASTROGAM mission. Exploring the extreme Universe with gamma rays in the MeV - GeV range

    Science.gov (United States)

    De Angelis, A.; Tatischeff, V.; Tavani, M.; Oberlack, U.; Grenier, I.; Hanlon, L.; Walter, R.; Argan, A.; von Ballmoos, P.; Bulgarelli, A.; Donnarumma, I.; Hernanz, M.; Kuvvetli, I.; Pearce, M.; Zdziarski, A.; Aboudan, A.; Ajello, M.; Ambrosi, G.; Bernard, D.; Bernardini, E.; Bonvicini, V.; Brogna, A.; Branchesi, M.; Budtz-Jorgensen, C.; Bykov, A.; Campana, R.; Cardillo, M.; Coppi, P.; De Martino, D.; Diehl, R.; Doro, M.; Fioretti, V.; Funk, S.; Ghisellini, G.; Grove, E.; Hamadache, C.; Hartmann, D. H.; Hayashida, M.; Isern, J.; Kanbach, G.; Kiener, J.; Knödlseder, J.; Labanti, C.; Laurent, P.; Limousin, O.; Longo, F.; Mannheim, K.; Marisaldi, M.; Martinez, M.; Mazziotta, M. N.; McEnery, J.; Mereghetti, S.; Minervini, G.; Moiseev, A.; Morselli, A.; Nakazawa, K.; Orleanski, P.; Paredes, J. M.; Patricelli, B.; Peyré, J.; Piano, G.; Pohl, M.; Ramarijaona, H.; Rando, R.; Reichardt, I.; Roncadelli, M.; Silva, R.; Tavecchio, F.; Thompson, D. J.; Turolla, R.; Ulyanov, A.; Vacchi, A.; Wu, X.; Zoglauer, A.

    2017-10-01

    e-ASTROGAM (`enhanced ASTROGAM') is a breakthrough Observatory space mission, with a detector composed by a Silicon tracker, a calorimeter, and an anticoincidence system, dedicated to the study of the non-thermal Universe in the photon energy range from 0.3 MeV to 3 GeV - the lower energy limit can be pushed to energies as low as 150 keV, albeit with rapidly degrading angular resolution, for the tracker, and to 30 keV for calorimetric detection. The mission is based on an advanced space-proven detector technology, with unprecedented sensitivity, angular and energy resolution, combined with polarimetric capability. Thanks to its performance in the MeV-GeV domain, substantially improving its predecessors, e-ASTROGAM will open a new window on the non-thermal Universe, making pioneering observations of the most powerful Galactic and extragalactic sources, elucidating the nature of their relativistic outflows and their effects on the surroundings. With a line sensitivity in the MeV energy range one to two orders of magnitude better than previous generation instruments, e-ASTROGAM will determine the origin of key isotopes fundamental for the understanding of supernova explosion and the chemical evolution of our Galaxy. The mission will provide unique data of significant interest to a broad astronomical community, complementary to powerful observatories such as LIGO-Virgo-GEO600-KAGRA, SKA, ALMA, E-ELT, TMT, LSST, JWST, Athena, CTA, IceCube, KM3NeT, and the promise of eLISA.

  12. Activation cross-sections of proton induced nuclear reactions on thulium in the 20-45 MeV energy range

    Energy Technology Data Exchange (ETDEWEB)

    Tarkanyi, F. [Institute of Nuclear Research of the Hungarian Academy of Sciences (ATOMKI), Debrecen (Hungary); Hermanne, A. [Cyclotron Laboratoryt, Vrije Universiteit Brussel (VUB), Brussels (Belgium); Takacs, S. [Institute of Nuclear Research of the Hungarian Academy of Sciences (ATOMKI), Debrecen (Hungary); Ditroi, F., E-mail: ditroi@atomki.hu [Institute of Nuclear Research of the Hungarian Academy of Sciences (ATOMKI), Debrecen (Hungary); Spahn, I. [Institut fuer Nuklearchemie, Forschungszentrum Juelich GmbH, Juelich (Germany); Ignatyuk, A.V. [Institute of Physics and Power Engineering (IPPE), Obninsk (Russian Federation)

    2012-01-15

    Cross-sections of proton induced nuclear reactions on {sup 169}Tm were measured in the 20-45 MeV energy range using the standard stacked-foil irradiation technique and high resolution gamma-ray spectroscopy. Experimental cross-sections and derived integral yields are reported for the production of {sup 169,167,166}Yb and {sup 168,167,166}Tm radioisotopes. The experimental data are analysed and compared to results of the earlier measurements and the theoretical model codes ALICE-IPPE, EMPIRE and TALYS. Application of the new cross-sections to the production of the {sup 167}Tm medical radioisotope is discussed. - Highlights: Black-Right-Pointing-Pointer Proton induced reactions on thulium target. Black-Right-Pointing-Pointer Stacked foil technique to cover a broad energy range in a single irradiation. Black-Right-Pointing-Pointer Comparison of experimental results with the ALICE, EMPIRE and TALYS theoretical codes. Black-Right-Pointing-Pointer Evaluation of medical impact. Black-Right-Pointing-Pointer Calculation of thick target integral yield.

  13. Excitation functions of alpha particles induced nuclear reactions on natural titanium in the energy range of 10.4–50.2 MeV

    Energy Technology Data Exchange (ETDEWEB)

    Usman, Ahmed Rufai [Department of Physics, University of Malaya, 50603 Kuala Lumpur (Malaysia); Nishina Center for Accelerator-Based Science, RIKEN, Wako, Saitama 351-0198 (Japan); Department of Physics, Umaru Musa Yar' adua University, Katsina (Nigeria); Khandaker, Mayeen Uddin, E-mail: mu_khandaker@um.edu.my [Department of Physics, University of Malaya, 50603 Kuala Lumpur (Malaysia); Haba, Hiromitsu [Nishina Center for Accelerator-Based Science, RIKEN, Wako, Saitama 351-0198 (Japan); Otuka, Naohiko [Nuclear Data Section, Division of Physical and Chemical Sciences, Department of Nuclear Sciences and Applications, International Atomic Energy Agency, A-1400 Vienna (Austria); Murakami, Masashi [Nishina Center for Accelerator-Based Science, RIKEN, Wako, Saitama 351-0198 (Japan)

    2017-05-15

    Highlights: • Detailed presentation of new results on experimental cross-sections of {sup nat}Ti(α,x) processes. • Calculations of thick target yields for scandium and other radionuclides via the {sup nat}Ti(α,x) production route. • Comparison with TENDL-2015 library. • Detailed review of previous experimental data. - Abstract: We studied the excitation functions of residual radionuclide productions from α particles bombardment on natural titanium in the energy range of 10.4–50.2 MeV. A well-established stacked-foil activation technique combined with HPGe γ-ray spectrometry was used to measure the excitation functions for the {sup 51,49,48}Cr, {sup 48}V, {sup 43}K, and {sup 43,44m,44g,46g+m,47,48}Sc radionuclides. The thick target yields for all assessed radionuclides were also calculated. The obtained experimental data were compared with the earlier experimental ones and also with the evaluated data in the TENDL-2015 library. A reasonable agreement was found between this work and some of the previous ones, while a partial agreement was found with the evaluated data. The present results would further enrich the experimental database and facilitate the understanding of existing discrepancies among the previous measurements. The results would also help to enhance the prediction capability of the nuclear reaction model codes.

  14. Application of PWO crystals for detection of low-activity gamma- radiation in the energy range above 3 MeV

    CERN Document Server

    Drobychev, G Yu; Fedorov, A A; Khruschinsky, A A; Korjik, M V; Lecoq, P; Missevitch, O V; 10.1016/j.nima.2004.08.059

    2005-01-01

    Lead tungstate PbWO4 (PWO) scintillator was developed during the R&D project initiated in a frame of preparation of experiments in high- energy physics to be carried out at new generation of colliders like LHC (CERN, Geneva, Switzerland). Compared to other promising fast and dense scintillators, PWO is an optimal compromise to make a very compact detector with good performance and the best price/performance ratio. Moreover, the results of PWO development carried out by the INP team together with collaborators show that scintillation parameters of PWO crystals can be further modified, which significantly extends opportunities of PWO application. One such field where an application of PWO scintillator can be very advantageous is a detection of low-activity gamma-radiation in the energy range above 3 MeV. Application of heavy scintillator allows to decrease a detector volume and therefore to reduce background. According to our preliminary estimations, PWO scintillation crystal will allow to reach significant...

  15. A study of $e^{+}e^{-}$ annihilation into hadrons in the 1600-2200 MeV energy range with the magnetic detector DMI at DCI

    CERN Document Server

    Bizot, J C; Cordier, A.; Delcourt, B.; Derado, I.; Eschstruth, P.; Fayard, L.; Jeanjean, J.; Jeanjean, M.; Mane, F.; Parvan, J.C.; Ribes, M.; Rumpf, F.; Bertrand, J.L.; Bisello, D.

    1979-01-01

    We Presents the results obtained with the Magnetic Detector DM1 on the Orsay e/sup +/e/sup -/ colliding beams (DCI) for 1570< square root S<2180 MeV. The total integrated luminosity is 936 nb/sup -1/ over the whole energy range. Kinematics of annihilation events is determined by momentum measurements on the charged particles with an accuracy Delta p/p approximately=2.5% at 500 MeV/c over a solid angle Omega =.6*4 pi sr. Cross sections are given for e/sup +/e/sup -/ annihilation into pp, into four and five pions: pi /sup +/ pi /sup -/ pi /sup +/ pi /sup -/ including rho /sup +/ pi /sup +/ pi /sup -/, pi /sup +/ pi /sup -/ pi /sup +/ pi /sup -/ pi /sup 0/ including omega pi /sup +/ pi /sup - /, and into strange mesons K/sup +/K/sup -/, K/sub S//sup 0/K/sub L //sup 0/, KK*, KK pi pi including K*K pi , inclusive K/sub S//sup 0/. Limits on rare channels like baryonium states, phi /sup 0/ pi /sup 0/, phi /sup 0/ eta /sup 0/ are also obtained. (9 refs).

  16. Excitation functions of alpha particles induced nuclear reactions on natural titanium in the energy range of 10.4-50.2 MeV

    Science.gov (United States)

    Usman, Ahmed Rufai; Khandaker, Mayeen Uddin; Haba, Hiromitsu; Otuka, Naohiko; Murakami, Masashi

    2017-05-01

    We studied the excitation functions of residual radionuclide productions from α particles bombardment on natural titanium in the energy range of 10.4-50.2 MeV. A well-established stacked-foil activation technique combined with HPGe γ-ray spectrometry was used to measure the excitation functions for the 51,49,48Cr, 48V, 43K, and 43,44m,44g,46g+m,47,48Sc radionuclides. The thick target yields for all assessed radionuclides were also calculated. The obtained experimental data were compared with the earlier experimental ones and also with the evaluated data in the TENDL-2015 library. A reasonable agreement was found between this work and some of the previous ones, while a partial agreement was found with the evaluated data. The present results would further enrich the experimental database and facilitate the understanding of existing discrepancies among the previous measurements. The results would also help to enhance the prediction capability of the nuclear reaction model codes.

  17. Nuclide production by proton-induced reactions on elements (6 <= Z <= 29) in the energy range from 800 to 2600 MeV

    Science.gov (United States)

    Michel, R.; Gloris, M.; Lange, H.-J.; Leya, I.; Lüpke, M.; Herpers, U.; Dittrich-Hannen, B.; Rösel, R.; Schiekel, Th.; Filges, D.; Dragovitsch, P.; Suter, M.; Hofmann, H.-J.; Wölfli, W.; Kubik, P. W.; Baur, H.; Wieler, R.

    1995-10-01

    In the course of a systematic investigation of proton-induced reactions for p energies between 800 and 2600 MeV, the target elements O, Mg, Al, Si, Ca, Ti, V, Mn, Fe, Co, Ni, Cu, Zr, Rh, Nb, Ba and Au were irradiated with 800 MeV protons at LAMPF/Los Alamos National Laboratory, and with 1200, 1600 and 2600 MeV protons at Laboratoire National Saturne/Saclay. The 1600 MeV irradiations covered in addition the target elements C, N, Rb, Sr, Y. The study was designed to measure production cross sections of radionuclides by γ-spectrometry and by accelerator mass spectrometry and of stable rare gas isotopes by conventional mass spectrometry. A detailed analysis of secondary particle fields was performed for targets of different thicknesses. Corrections for interferences by secondaries were made on the basis of secondary particle spectra as calculated by the code HET in the form of the HERMES code system and experimental and theoretical excitation functions of p- and n-induced reactions. Here, about 700 cross sections for the production of radionuclides from target elements Z ≤ 29 (Cu) by more than 200 reactions are presented. In addition, cross sections for the production of stable He and Ne isotopes from iron at a proton energy of 600 MeV are given. Together with earlier work of our group, there now exists a consistent set of excitation functions from threshold energies up to 2600 MeV. A comparison of the new data with earlier measurements from other authors exhibited a considerable lack of reliability for many of the earlier data. On the basis of the new data, the quality of existing semiempirical formulas for the calculation of spallation cross sections is discussed. In a more physical approach, the production of residual nuclides is calculated in the framework of an INC/E model using Monte Carlo techniques for energies between 100 MeV and 5 GeV and compared with the experimental results.

  18. WISP Dark Matter eXperiment and Prospects for Broadband Dark Matter Searches in the $1\\,\\mu$eV--$10\\,$meV Mass Range

    CERN Document Server

    Horns, Dieter; Lobanov, Andrei; Ringwald, Andreas

    2014-01-01

    Light cold dark matter consisting of weakly interacting slim (or sub-eV) particles (WISPs) has been in the focus of a large number of studies made over the past two decades. The QCD axion and axion-like particles with masses in the $0.1\\,\\mu$eV--$100\\,$meV are strong candidates for the dark matter particle, together with hidden photons with masses below $\\lesssim 100\\,$meV. This motivates several new initiatives in the field, including the WISP Dark Matter eXperiment (WISPDMX) and novel conceptual approaches for broad-band WISP searches using radiometry measurements in large volume chambers. First results and future prospects for these experiments are discussed in this contribution.

  19. OBSERVATIONS OF THE 2006 DECEMBER 13 AND 14 SOLAR PARTICLE EVENTS IN THE 80 MeV n{sup -1}-3 GeV n{sup -1} RANGE FROM SPACE WITH THE PAMELA DETECTOR

    Energy Technology Data Exchange (ETDEWEB)

    Adriani, O.; Bonechi, L. [Department of Physics, 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. [Department of Physics, University of Bari, I-70126 Bari (Italy); Boezio, M.; Bonvicini, V. [INFN, Sezione di Trieste, I-34149 Trieste (Italy); Bogomolov, E. A. [Ioffe Physical Technical Institute, RU-194021 St. Petersburg (Russian Federation); Bongi, M.; Bottai, S. [INFN, Sezione di Florence, I-50019 Sesto Fiorentino, Florence (Italy); Borisov, S.; Casolino, M.; De Pascale, M. P. [INFN, Sezione di Rome Tor Vergata, I-00133 Rome (Italy); Cafagna, F. [INFN, Sezione di Bari, I-70126 Bari (Italy); Campana, D.; Carbone, R.; Consiglio, L. [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); Castellini, G. [IFAC, I-50019 Sesto Fiorentino, Florence (Italy); and others

    2011-12-01

    We present the space spectrometer PAMELA observations of proton and helium fluxes during the 2006 December 13 and 14 solar particle events. This is the first direct measurement of the solar energetic particles in space with a single instrument in the energy range from {approx}80 MeV n{sup -1} up to {approx}3 GeV n{sup -1}. For the December 13 event, measured energy spectra of solar protons and helium are compared with results obtained by neutron monitors and other detectors. Our measurements show a spectral behavior different from those derived from the neutron monitor network. No satisfactory analytical fitting was found for the energy spectra. During the first hours of the December 13 event, solar energetic particles spectra were close to the exponential form, demonstrating rather significant temporal evolution. Solar He with energy up to 1 GeV n{sup -1} was recorded on December 13. For the December 14 event, energy of solar protons reached 600 MeV, whereas the maximum energy of He was below 100 MeV n{sup -1}. The spectra were slightly bent in the lower energy range and preserved their form during the second event. Differences in the particle flux appearance and temporal evolution of these two events may argue for special conditions leading to the acceleration of solar particles up to relativistic energies.

  20. Extension of the energy range of the experimental activation cross-sections data of longer-lived products of proton induced nuclear reactions on dysprosium up to 65MeV.

    Science.gov (United States)

    Tárkányi, F; Ditrói, F; Takács, S; Hermanne, A; Ignatyuk, A V

    2015-04-01

    Activation cross-sections data of longer-lived products of proton induced nuclear reactions on dysprosium were extended up to 65MeV by using stacked foil irradiation and gamma spectrometry experimental methods. Experimental cross-sections data for the formation of the radionuclides (159)Dy, (157)Dy, (155)Dy, (161)Tb, (160)Tb, (156)Tb, (155)Tb, (154m2)Tb, (154m1)Tb, (154g)Tb, (153)Tb, (152)Tb and (151)Tb are reported in the 36-65MeV energy range, and compared with an old dataset from 1964. The experimental data were also compared with the results of cross section calculations of the ALICE and EMPIRE nuclear model codes and of the TALYS nuclear reaction model code as listed in the latest on-line libraries TENDL 2013. Copyright © 2015. Published by Elsevier Ltd.

  1. CSDA range, stopping power and mean penetration depth energy relationships in some hydrocarbons and biologic materials for 10 eV to 100 MeV with the modified Rohrlich-Carlson model

    Science.gov (United States)

    Gümüş, Hasan; Bentabet, Abdelouahab

    2017-05-01

    In this study, for some hydrocarbons and biological compounds, stopping power formula are presented, being valid for low and intermediate electron energies. In addition, calculation of the continuous slowing down approximation range (CSDA range) from the stopping power is also made. Calculation of the CSDA range for some hydrocarbons: C2H6 (ethane), C4H10 (butane), C6H14 (hexane) C8H18 (octane), C5H5N5 (adenine) and C5H5N5O (guanine) have been introduced for incident electrons in the energy range 30 eV to 1 MeV. The range of electrons has been calculated within the continuous slowing down approximation (CSDA) using modified Rohrlich and Carlson formula of stopping power. Besides, we have calculated the mean penetration depths using a spherical geometric model developed by Bentabet (Vacuum 86:1855-1859, 35). The results have been compared with the other theoretical results, Monte Carlo code such as PENELOPE predictions and semi-empirical results. The calculated results of CSDA ranges for electrons in the energy range from 20 eV to 100 MeV are found to be in good agreement to within 10% with available date.

  2. CSDA range, stopping power and mean penetration depth energy relationships in some hydrocarbons and biologic materials for 10 eV to 100 MeV with the modified Rohrlich-Carlson model

    Energy Technology Data Exchange (ETDEWEB)

    Guemues, Hasan [Ondokuz Mayis University, Department of Physics, Faculty of Sciences and Arts, Samsun (Turkey); Bentabet, Abdelouahab [Bordj Bou Arreridj University, LCVRN, SNVSTU Faculty, El Anasser (Algeria)

    2017-05-15

    In this study, for some hydrocarbons and biological compounds, stopping power formula are presented, being valid for low and intermediate electron energies. In addition, calculation of the continuous slowing down approximation range (CSDA range) from the stopping power is also made. Calculation of the CSDA range for some hydrocarbons: C{sub 2}H{sub 6} (ethane), C{sub 4}H{sub 10} (butane), C{sub 6}H{sub 14} (hexane) C{sub 8}H{sub 18} (octane), C{sub 5}H{sub 5}N{sub 5} (adenine) and C{sub 5}H{sub 5}N{sub 5}O (guanine) have been introduced for incident electrons in the energy range 30 eV to 1 MeV. The range of electrons has been calculated within the continuous slowing down approximation (CSDA) using modified Rohrlich and Carlson formula of stopping power. Besides, we have calculated the mean penetration depths using a spherical geometric model developed by Bentabet (Vacuum 86:1855-1859, 35). The results have been compared with the other theoretical results, Monte Carlo code such as PENELOPE predictions and semi-empirical results. The calculated results of CSDA ranges for electrons in the energy range from 20 eV to 100 MeV are found to be in good agreement to within 10% with available date. (orig.)

  3. Study of the process e+e- → π+π-π0η in the c.m. energy range 1394-2005 MeV with the CMD-3 detector

    Science.gov (United States)

    Akhmetshin, R. R.; Amirkhanov, A. N.; Anisenkov, A. V.; Aulchenko, V. M.; Banzarov, V. Sh.; Bashtovoy, N. S.; Berkaev, D. E.; Bondar, A. E.; Bragin, A. V.; Eidelman, S. I.; Epifanov, D. A.; Epshteyn, L. B.; Erofeev, A. L.; Fedotovich, G. V.; Gayazov, S. E.; Grebenuk, A. A.; Gribanov, S. S.; Grigoriev, D. N.; Ignatov, F. V.; Ivanov, V. L.; Karpov, S. V.; Kazanin, V. F.; Koop, I. A.; Kirpotin, A. N.; Korobov, A. A.; Kozyrev, A. N.; Kozyrev, E. A.; Krokovny, P. P.; Kuzmenko, A. E.; Kuzmin, A. S.; Logashenko, I. B.; Lukin, P. A.; Mikhailov, K. Yu.; Okhapkin, V. S.; Otboev, A. V.; Pestov, Yu. N.; Popov, A. S.; Razuvaev, G. P.; Rogovsky, Yu. A.; Ruban, A. A.; Ryskulov, N. M.; Ryzhenenkov, A. E.; Senchenko, A. I.; Shatunov, Yu. M.; Shatunov, P. Yu.; Shebalin, V. E.; Shemyakin, D. N.; Shwartz, B. A.; Shwartz, D. B.; Sibidanov, A. L.; Solodov, E. P.; Titov, V. M.; Talyshev, A. A.; Vorobiov, A. I.; Zemlyansky, I. M.; Yudin, Yu. V.

    2017-10-01

    The cross section of the process e+e- →π+π-π0 η has been measured using a data sample of 21.8 pb-1 collected with the CMD-3 detector at the VEPP-2000 e+e- collider. 2769 ± 95 signal events have been selected in the center-of-mass energy range 1394-2005 MeV. The production dynamics is dominated by the ω (782) η and ϕ (1020) η intermediate states in the lower energy range, and by the a0 (980) ρ (770) intermediate state at higher energies.

  4. Studies on effective atomic numbers for photon energy absorption and electron density of some narcotic drugs in the energy range 1 keV-20 MeV

    Science.gov (United States)

    Gounhalli, Shivraj G.; Shantappa, Anil; Hanagodimath, S. M.

    2013-04-01

    Effective atomic numbers for photon energy absorption ZPEA,eff, photon interaction ZPI,eff and for electron density Nel, have been calculated by a direct method in the photon-energy region from 1 keV to 20 MeV for narcotic drugs, such as Heroin (H), Cocaine (CO), Caffeine (CA), Tetrahydrocannabinol (THC), Cannabinol (CBD), Tetrahydrocannabivarin (THCV). The ZPEA,eff, ZPI,eff and Nel values have been found to change with energy and composition of the narcotic drugs. The energy dependence ZPEA,eff, ZPI,eff and Nel is shown graphically. The maximum difference between the values of ZPEA,eff, and ZPI,eff occurs at 30 keV and the significant difference of 2 to 33% for the energy region 5-100 keV for all drugs. The reason for these differences is discussed.

  5. Characterization of the PTW 34031 ionization chamber (PMI at RCNP with high energy neutrons ranging from 100 – 392 MeV

    Directory of Open Access Journals (Sweden)

    Theis C.

    2017-01-01

    Full Text Available Radiation monitoring at high energy proton accelerators poses a considerable challenge due to the complexity of the encountered stray radiation fields. These environments comprise a wide variety of different particle types and span from fractions of electron-volts up to several terra electron-volts. As a consequence the use of Monte Carlo simulation programs like FLUKA is indispensable to obtain appropriate field-specific calibration factors. At many locations of the LHC a large contribution to the particle fluence is expected to originate from high-energy neutrons and thus, benchmark experiments with mono-energetic neutron beams are of high importance to verify the aforementioned detector response calculations. This paper summarizes the results of a series of benchmark experiments with quasi mono-energetic neutrons of 100, 140, 200, 250 and 392 MeV that have been carried out at RCNP - Osaka University, during several campaigns between 2006 and 2014.

  6. Electron transport simulation in the range 1 keV-4 MeV for the purpose of high-resolution dosimetric application

    Energy Technology Data Exchange (ETDEWEB)

    Cobut, V. [Univ. de Cergy-Pontoise, Neuville/Oise (France). Lab. Pharmacophores Redox, Phytochimie et Radiobiologie; Cirioni, L.; Patau, J.P. [Univ. Paul Sabatier, Toulouse (France). Faculte de Pharmacie

    2001-07-01

    Experimental spectrometry and dosimetry can offer some reliable answers. However, they are not easy to implement in some specific situations. Furthermore, information on dose distributions cannot always be obtained with the desirable geometrical resolution. A way to get rid of these disadvantages consist in simulating every successive individual interactions suffered by electrons and photons along their path. We applied this principle to simulate the response of a detector placed in the field of beta-gamma sources, which maximum energy does not exceed 4 MeV. A part of this work is presented here, which concerns Monte Carlo simulation of electron transport in materials encountered in experimental dosimetric devices. Electrons were followed down to a cutoff energy of 1 keV. (orig.)

  7. Neutron-induced fission cross-section of {sup 233}U in the energy range 0.5MeV

    Energy Technology Data Exchange (ETDEWEB)

    Belloni, F.; Milazzo, P.M.; Abbondanno, U.; Fujii, K.; Moreau, C. [Istituto Nazionale di Fisica Nucleare (INFN), Trieste (Italy); Calviani, M. [Laboratori Nazionali di Legnaro, Istituto Nazionale di Fisica Nucleare (INFN), Legnaro (Italy); CERN, Geneva (Switzerland); Colonna, N.; Marrone, S.; Meaze, M.H.; Tagliente, G.; Terlizzi, R. [Istituto Nazionale di Fisica Nucleare (INFN), Bari (Italy); Mastinu, P.; Gramegna, F. [Laboratori Nazionali di Legnaro, Istituto Nazionale di Fisica Nucleare, Legnaro (Italy); Aerts, G.; Andriamonje, S.; Berthoumieux, E.; Dridi, W.; Gunsing, F.; Pancin, J.; Perrot, L.; Plukis, A. [CEA, Irfu, Gif-sur-Yvette (France); Alvarez, H.; Cano-Ott, D.; Duran, I.; Embid-Segura, M.; Gonzalez-Romero, E.; Paradela, C. [Univ. de Santiago de Compostela, Santiago (Spain); Alvarez-Velarde, F.; Guerrero, C.; Martinez, T.; Villamarin, D.; Vincente, M.C. [Centro de Investigaciones Energeticas Medioambientales y Technologicas, Madrid (Spain); Andrzejewski, J.; Marganiec, J. [Univ. of Lodz, Lodz (Poland); Audouin, L.; Dillmann, I.; Heil, M.; Kaeppeler, F.; Mosconi, M.; Plag, R.; Voss, F.; Walter, S.; Wisshak, K. [Inst. fuer Kernphysik, Karlsruhe Inst. of Technology, Campus Nord, Karlsruhe (Germany); Badurek, G.; Jericha, E.; Leeb, H.; Oberhummer, H.; Pigni, M.T. [Technische Univ. Wien, Atominstitut der Oesterreichischen Univ., Wien (Austria); Baumann, P.; David, S.; Kerveno, M.; Lukic, S.; Rudolf, G. [Centre National de la Recherche Scientifique/IN2P3 - IReS, Strasbourg (France); Becvar, F.; Krticka, M. [Charles Univ., Faculty of Mathematics and Physics, Prague (Czech Republic); Calvino, F.; Cortes, G.; Poch, A.; Pretel, C. [Univ. Politecnica de Catalunya, Barcelona (Spain); Capote, R. [NAPC/Nuclear Data Section, International Atomic Energy Agency, Vienna (Austria); Univ. de Sevilla, Sevilla (Spain); Carrapico, C.; Goncalves, I.; Salgado, J.; Santos, C.; Tavora, L.; Vaz, P. [Inst. Tecnologico e Nuclear, Lisbon (Portugal)] [and others

    2011-01-15

    The neutron-induced fission cross-section of {sup 233}U has been measured at the CERN n-TOF facility relative to the standard fission cross-section of {sup 235}U between 0.5 and 20MeV. The experiment was performed with a fast ionization chamber for the detection of the fission fragments and to discriminate against {alpha} -particles from the natural radioactivity of the samples. The high instantaneous flux and the low background of the n-TOF facility result in data with uncertainties of {approx} 3%, which were found in good agreement with previous experiments. The high quality of the present results allows to improve the evaluation of the {sup 233}U (n,f) cross-section and, consequently, the design of energy systems based on the Th/U cycle. (orig.)

  8. Measurement of 58Fe (p , n)58Co reaction cross-section within the proton energy range of 3.38 to 19.63 MeV

    Science.gov (United States)

    Ghosh, Reetuparna; Badwar, Sylvia; Lawriniang, Bioletty; Jyrwa, Betylda; Naik, Haldhara; Naik, Yeshwant; Suryanarayana, Saraswatula Venkata; Ganesan, Srinivasan

    2017-08-01

    The 58Fe (p , n)58Co reaction cross-section within Giant Dipole Resonance (GDR) region i.e. from 3.38 to 19.63 MeV was measured by stacked-foil activation and off-line γ-ray spectrometric technique using the BARC-TIFR Pelletron facility at Mumbai. The present data were compared with the existing literature data and found to be in good agreement. The 58Fe (p , n)58Co reaction cross-section as a function of proton energy was also theoretically calculated by using the computer code TALYS-1.8 and found to be in good agreement, which shows the validity of the TALYS-1.8 program.

  9. Neutron cross section evaluations of europium isotopes in 1 keV - 30 MeV energy range. Format - validation - comparison; Evaluation de sections efficaces pour des neutrons incidents sur des isotopes d'europium aux energies 1 keV - 30 MeV. Format - validation - comparaison

    Energy Technology Data Exchange (ETDEWEB)

    Dossantos-Uzarralde, P.; Le Luel, C.; Bauge, E. [CEA Bruyeres le Chatel, 91 (France). Dept. de Physique Theorique et Appliquee

    2004-07-01

    This paper presents neutron cross section evaluations of Europium isotopes. The cross sections are evaluated in 1 keV - 30 MeV energy range for the isotopes {sup 146}Eu, {sup 147}Eu, {sup 148}Eu, {sup 149}Eu, {sup 150}Eu, {sup 151}Eu, {sup 152}Eu, {sup 153}Eu, {sup 154}Eu in their ground state. This evaluation includes cross section productions of the long life isomeric states. Special attention is put on the options used for the description of the files written in ENDF-6 format. The final issue is a proposal of a new breed of ENDF-6 formatted neutron activation file. (authors)

  10. Study of the Dynamics in a Linac Booster for Proton Therapy in the 30-62 MeV Energy Range

    CERN Document Server

    Vaccaro, Vittorio G; De Martinis, Carlo; Giove, Dario; Lanzone, S; Masullo, Maria R; Mauri, Marco; Rainò, Antonio; Variale, Vincenzo

    2005-01-01

    Recent results in accelerator physics have shown the feasibility of a coupling scheme between a cyclotron and a linac for proton acceleration. Cyclotrons with energies up to 30 MeV, mainly devoted to radioisotopes production, are available in a large number of medical centres. These two evidences have suggested the idea to study and design a linac booster able to increase the initial proton energy up to the values required for the treatment of tumors, like the ocular ones. Among the challenges in such a project one of the main ones is related to meet the requirement of having sufficient mean current for therapy from a given injection current coming from the cyclotron. In this paper we will review the rationale of the project in order to optimize the transmittance and to minimize the duty-cycle. In this frame we will discuss the basic design of a compact 3GHz linac with a new approach to the cavities used in a SCL (Side Coupled Linac) structure.

  11. Tables of range and stopping power of chemical elements for charged particles of energy 0.5 to 500 MeV; Tables de parcours et de pouvoirs d'arret des elements chimiques pour des particules chargees de 0,05 a 500 MeV d'energie

    Energy Technology Data Exchange (ETDEWEB)

    Williamson, C.; Boujot, J.; Picard, J. [Commissariat a l' Energie Atomique, Centre d' Etudes Nucleaires de Saclay, 91 - Gif-sur-Yvette (France)

    1966-07-01

    The range, energy loss, and differential of rate of energy loss were tabulated for 5 incident particles or ions (proton, deuteron, triton, helium-3 and helium-4) and for 37 target materials (H, He, Li, Be, B, C, N, O, F, Ne, Na, Al, Si, Cl, Ca, V, Fe, Ni, Cu, Ge, Br, Y, Zr, Mo, Rh, Ag, Cd, Sn, I, Cs, Nd, Gd, Er, Ta, Au, Pb, U) The incident energy range covered is from 0.05 to 500 MeV. An erratum report is added: 74 pages from 223 to 296 of the initial report have to be replaced by the pages contained in the erratum report. [French] Les valeurs du parcours, du pouvoir d'arret et de la derivee du pouvoir d'arret par rapport a l'energie des ions d'hydrogene et d'helium dans 37 elements chimiques ont ete tabulees pour des energies de particule incidente variant de 0.05 a 500 MeV. (auteurs)

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

    Energy Technology Data Exchange (ETDEWEB)

    Sato, Yuki, E-mail: sato.yuki@jaea.go.jp [Collaborative Laboratories for Advanced Decommissioning Science (CLADS), Japan Atomic Energy Agency, 2–4 Shirane Shirakata, Tokai-mura, Naka-gun, Ibaraki 319-1195 (Japan); Murakami, Hiroyuki [RIKEN Nishina Center for Accelerator-Based Science, RIKEN, 2–1Hirosawa, Wako, Saitama 351-0198 (Japan); Shimaoka, Takehiro; Tsubota, Masakatsu; Kaneko, Junichi H. [Graduate School of Engineering, Hokkaido University, N13, W8, Kita-ku, Sapporo 060-8628 (Japan)

    2016-10-21

    The performance of a diamond detector created from a single-crystal diamond grown by chemical vapor deposition was studied for application in detecting charged particles having energies ranging from 100 keV to 2 MeV. Energy peaks of different low-energy ions were clearly observed. However, we observed that the pulse height for individual incident ions decreases with increasing atomic number of the ions. We estimated the charge collection efficiency of the generated charge carriers by the incident charged particles. The charge collection efficiencies are 97.0 ± 0.7% for 2 MeV helium-ions (He{sup +}). On the other hand, compared with that of He{sup +}, silicon-ions (Si{sup +}) and gold-ions (Au{sup 3+}) show low charge collection efficiency: 70.6 ± 2.2% and 29.5 ± 4.2% for 2 MeV-Si{sup +} and 2 MeV-Au{sup 3+}, respectively. We also found that the charge collection efficiency decreases as the generated charge density inside the diamond crystal increases.

  13. Cross-sections for formation of {sup 89}Zr{sup m} through {sup 90}Zr(n,2n){sup 89}Zr{sup m} reaction over neutron energy range 13.73 MeV to 14.77 MeV

    Energy Technology Data Exchange (ETDEWEB)

    Attar, F.M.D. [Department of Physics, University of Pune, Pune-411007 (India); Mandal, R. [Department of Physics, University of Pune, Pune-411007 (India); Indian Institute of Technology, Kharagpur (India); Dhole, S.D. [Department of Physics, University of Pune, Pune-411007 (India); Saxena, A. [Nuclear Physics Division, BARC, Mumbai (India); Ashokkumar,; Ganesan, S. [Reactor Physics Design Division, BARC, Mumbai (India); Kailas, S. [Nuclear Physics Division, BARC, Mumbai (India); Bhoraskar, V.N. [Department of Physics, University of Pune, Pune-411007 (India)], E-mail: vnb@physics.unipune.ernet.in

    2008-04-01

    The cross-sections for formation of metastable state of {sup 89}Zr ({sup 89}Zr{sup m}, 0.588 MeV, 4.16 m) through {sup 90}Zr(n,2n){sup 89}Zr{sup m} reaction induced by 13.73 MeV to 14.77 MeV neutrons were measured for the first time and also theoretically estimated using Empire-II and Talys programs. At 13.73 MeV neutron energy, the {sup 89}Zr nuclei can be excited to metastable state, {sup 89}Zr{sup m}, when the first and the second emitted neutrons have energies lower than the most probable energy {approx}0.64 MeV. The probability of exciting {sup 89}Zr nuclei to energy levels higher than 0.588 MeV and therefore of populating the metastable state through decay process increases with increasing neutron energy. The measured cross-sections vary from 41{+-}3mb to 221{+-}15mb over neutron energies 13.73 MeV to 14.77 MeV, and are in agreement with the cross-sections estimated using Empire-II code. The formation of {sup 89}Zr{sup m} is favoured when the first and the second reaction neutrons are emitted with the most probable energies rather than lower energy, except for 13.73 MeV neutrons.

  14. Study of the process e+e- → KS0 KL0 in the center-of-mass energy range 1004-1060 MeV with the CMD-3 detector at the VEPP-2000 e+e- collider

    Science.gov (United States)

    Kozyrev, E. A.; Solodov, E. P.; Amirkhanov, A. N.; Anisenkov, A. V.; Aulchenko, V. M.; Banzarov, V. S.; Bashtovoy, N. S.; Berkaev, D. E.; Bondar, A. E.; Bragin, A. V.; Eidelman, S. I.; Epifanov, D. A.; Epshteyn, L. B.; Erofeev, A. L.; Fedotovich, G. V.; Gayazov, S. E.; Grebenuk, A. A.; Gribanov, S. S.; Grigoriev, D. N.; Ignatov, F. V.; Ivanov, V. L.; Karpov, S. V.; Kasaev, A. S.; Kazanin, V. F.; Kirpotin, A. N.; Korobov, A. A.; Kovalenko, O. A.; Kozyrev, A. N.; Koop, I. A.; Krokovny, P. P.; Kuzmenko, A. E.; Kuzmin, A. S.; Logashenko, I. B.; Lukin, P. A.; Mikhailov, K. Yu.; Okhapkin, V. S.; Otboev, A. V.; Pestov, Yu. N.; Popov, A. S.; Razuvaev, G. P.; Ruban, A. A.; Ryskulov, N. M.; Ryzhenenkov, A. E.; Senchenko, A. I.; Shebalin, V. E.; Shemyakin, D. N.; Shwartz, B. A.; Shwartz, D. B.; Sibidanov, A. L.; Shatunov, P. Yu.; Shatunov, Yu. M.; Titov, V. M.; Talyshev, A. A.; Vorobiov, A. I.; Yudin, Yu. V.

    2016-09-01

    The e+e- → KS0 KL0 cross section has been measured in the center-of-mass energy range 1004-1060 MeV at 25 energy points using 6.1 ×105 events with KS0 →π+π- decay. The analysis is based on 5.9 pb-1 of an integrated luminosity collected with the CMD-3 detector at the VEPP-2000 e+e- collider. To obtain ϕ (1020) meson parameters the measured cross section is approximated according to the Vector Meson Dominance model as a sum of the ρ , ω , ϕ-like amplitudes and their excitations. This is the most precise measurement of the e+e- → KS0 KL0 cross section with a 1.8% systematic uncertainty.

  15. Study of the process e+e−→π+π−π+π− in the c.m. energy range 920–1060 MeV with the CMD-3 detector

    Directory of Open Access Journals (Sweden)

    R.R. Akhmetshin

    2017-05-01

    Full Text Available A cross section of the process e+e−→π+π−π+π− has been measured using 6798±93 signal events from a data sample corresponding to an integrated luminosity of 9.8 pb−1 collected with the CMD-3 detector in the center-of-mass energy range 920–1060 MeV. The measured cross section exhibits a pattern of interference of the ϕ(1020→π+π−π+π− decay with a non-resonant process e+e−→π+π−π+π−, from which we obtain the branching fraction of the doubly suppressed decays (by G-parity and OZI rule: B(ϕ→π+π−π+π−=(6.5±2.7±1.6×10−6.

  16. Study of the process e+e- → π+π-π+π- in the c.m. energy range 920-1060 MeV with the CMD-3 detector

    Science.gov (United States)

    Akhmetshin, R. R.; Amirkhanov, A. N.; Anisenkov, A. V.; Aulchenko, V. M.; Banzarov, V. Sh.; Bashtovoy, N. S.; Berkaev, D. E.; Bondar, A. E.; Bragin, A. V.; Eidelman, S. I.; Epifanov, D. A.; Epshteyn, L. B.; Erofeev, A. L.; Fedotovich, G. V.; Gayazov, S. E.; Grebenuk, A. A.; Gribanov, S. S.; Grigoriev, D. N.; Ignatov, F. V.; Ivanov, V. L.; Karpov, S. V.; Kasaev, A. S.; Kazanin, V. F.; Koop, I. A.; Kovalenko, O. A.; Korobov, A. A.; Kozyrev, A. N.; Kozyrev, E. A.; Krokovny, P. P.; Kuzmenko, A. E.; Kuzmin, A. S.; Logashenko, I. B.; Lysenko, A. P.; Lukin, P. A.; Mikhailov, K. Yu.; Okhapkin, V. S.; Pestov, Yu. N.; Perevedentsev, E. A.; Popov, A. S.; Razuvaev, G. P.; Rogovsky, Yu. A.; Ruban, A. A.; Ryskulov, N. M.; Ryzhenenkov, A. E.; Shebalin, V. E.; Shemyakin, D. N.; Shwartz, B. A.; Shwartz, D. B.; Sibidanov, A. L.; Shatunov, Yu. M.; Solodov, E. P.; Titov, V. M.; Talyshev, A. A.; Vorobiov, A. I.; Yudin, Yu. V.

    2017-05-01

    A cross section of the process e+e- →π+π-π+π- has been measured using 6798 ± 93 signal events from a data sample corresponding to an integrated luminosity of 9.8 pb-1 collected with the CMD-3 detector in the center-of-mass energy range 920-1060 MeV. The measured cross section exhibits a pattern of interference of the ϕ (1020) →π+π-π+π- decay with a non-resonant process e+e- →π+π-π+π-, from which we obtain the branching fraction of the doubly suppressed decays (by G-parity and OZI rule): B (ϕ →π+π-π+π-) = (6.5 ± 2.7 ± 1.6) ×10-6.

  17. Elastic recoil cross section determination of deuterium by helium-4 ions at 30° with the energy range of 2.6–7.4 MeV

    Energy Technology Data Exchange (ETDEWEB)

    Han, Zhibin; Hao, Wanli; Wang, Chunjie; Shi, Liqun, E-mail: lqshi@fudan.edu.cn

    2016-05-15

    The elastic recoil cross section for D({sup 4}He, D) {sup 4}He was determined at a recoil angle of 30° over an incident helium energy range from 2.6 to 7.4 MeV. A thin solid target Ta/TiD{sub x}/Si used for cross section measurement was prepared by direct current magnetron sputtering, and it was so stable to ion beam bombardment that nearly no deuterium loss (less than 0.2%) exists over the whole experiment. A relative determination method is adopted in this measurement. It can avoid the error from the beam dose and the solid angle of the detectors and it is also free to direct measurement of D content in the film. The total uncertainty in the cross section determination is less than 5%.

  18. Determination of integral cross sections of 3H in Al foils monitors irradiated by protons with energies ranging from 40 to 2600 MeV

    Directory of Open Access Journals (Sweden)

    Titarenko Yu.E.

    2016-01-01

    Full Text Available The results of 3H production in Al foil monitors (∼ 59 mg/cm2 thickness are presented. These foils have been irradiated in 15×15 mm polyethylene bags of ∼ 14 mg/cm2 thickness together with foils of Cr (∼ 395 mg/cm2 thickness and 56Fe (∼ 332 mg/cm2 thickness by protons of different energies in a range of 0.04 – 2.6 GeV. The diameters of all the foils were 10.5 mm. The irradiations were carried out at the ITEP accelerator U–10 under the ISTC Project # 3266 in 2006–2009. 3H has been extracted from Al foils using an A307 Sample Oxidizer. An ultra low level liquid scintillation spectrometer Quantulus1220 was used to measure the 3H β–spectra and the SpectraDec software package was applied for spectra processing, deconvolution and 3H activity determination. The values of the Al (p, x3H reaction cross sections obtained in these experiments are compared with data measured at other labs and with results of simulations by the MCNP6 radiation transport code using the CEM03.03 event generator.

  19. Measurement of the neutron fields produced by a 62 MeV proton beam on a PMMA phantom using extended range Bonner sphere spectrometers

    Science.gov (United States)

    Amgarou, K.; Bedogni, R.; Domingo, C.; Esposito, A.; Gentile, A.; Carinci, G.; Russo, S.

    2011-10-01

    The experimental characterization of the neutron fields produced as parasitic effect in medical accelerators is assuming an increased importance for either the patient protection or the facility design aspects. Medical accelerators are diverse in terms of particle type (electrons or hadrons) and energy, but the radiation fields around them have in common (provided that a given threshold energy is reached) the presence of neutrons with energy span over several orders of magnitude. Due to the large variability of neutron energy, field or dosimetry measurements in these workplaces are very complex, and in general, cannot be performed with ready-to-use commercial instruments. In spite of its poor energy resolution, the Bonner Sphere Spectrometer (BSS) is the only instrument able to simultaneously determine all spectral components in such workplaces. The energy range of this instrument is limited to EFisica Nucleare—Laboratori Nazionali di Frascati) were exposed to characterize the "forward" and "sideward" proton-induced neutron fields. The use of two ERBSS characterized by different set of spheres, central detectors, and independently established and calibrated, is important for guaranteeing the robustness of the measured spectra and estimating their overall uncertainties.

  20. Energy loss, range, and bremsstrahlung yield for 10-keV to 100-MeV electrons in various elements and chemical compounds

    Science.gov (United States)

    Pages, Lucien; Bertel, Evelyne; Joffre, Henri; Sklavenitis, Laodamas

    2012-12-01

    Even though the United States lacks a national climate policy, significant action has occurred at the local and regional levels. Some of the most aggressive climate change policies have occurred at the state and local levels and in interagency cooperation on specific management issues. While there is a long history of partnerships in dealing with a wide variety of policy issues, the uncertainty and the political debate surrounding climate change has generated new challenges to establishing effective policy networks. This paper investigates the formation of climate policy networks in the State of Nevada. It presents a methodology based on social network analysis for assessing the structure and function of local policy networks across a range of substantive climate impacted resources (water, landscape management, conservation, forestry and others). It draws from an emerging literature on federalism and climate policy, public sector innovation, and institutional analysis in socio-ecological systems. Comparisons across different policy issue networks in the state are used to highlight the influence of network structure, connectivity, bridging across vertical and horizontal organizational units, organizational diversity, and flows between organizational nodes.

  1. Study of diffractive and refractive structure in the elastic sup 1 sup 6 O+ sup 1 sup 6 O scattering at incident energies ranging from 124 to 1120 MeV

    CERN Document Server

    Khoa, D T; Bohlen, H G; Nuoffer, F

    2000-01-01

    The experimental data on elastic sup 1 sup 6 O+ sup 1 sup 6 O scattering at incident energies ranging from 124 to 1120 MeV have been analyzed within the standard optical model (OM), using either the phenomenological (Woods-Saxon squared) potential or that calculated within the double-folding model for the real part of the optical potential. Structure of the elastic cross sections at smallest scattering angles was found to be of a pure diffractive nature, which enabled a consistent check of the absolute normalization of the elastic data under study. The OM analysis shows unambiguously the evolution of the refractive scattering pattern in the sup 1 sup 6 O+ sup 1 sup 6 O system over this energy range. The large angle region of the data is dominated by the refractive far-side scattering. The oscillating Airy structure can be consistently described by a set of optical potentials with the real part given by the folding model and a weak absorptive imaginary potential.

  2. Dynamical study of sup 1 H(d,gamma) sup 3 He tensor observables in the energy range of 80 kev to 95 MeV tests of effective two-body models

    CERN Document Server

    Fonseca, A C

    2000-01-01

    Realistic interactions are used to study sup 1 H(d, gamma) sup 3 He tensor observables in the energy range of 80 keV to 95 MeV deuteron laboratory energy, as well as the differential cross section for the two-body photodisintegration of sup 3 He. The Siegert form of the E1 multipole operator in the long-wavelength limit is taken as the sole component of the electromagnetic interaction. The three-body Faddeev equations for the bound-state and continuum wave functions are solved using the Paris, Argonne V14, Bonn-A, and Bonn-B potentials. The corresponding nucleon-nucleon t-matrices are represented in a separable form using the Ernst-Shakin-Thaler representation. The Coulomb force between protons is neglected and no three-nucleon force is included. The contribution of nucleon-nucleon P-wave components to the observables is carefully studied, not only in the angular distribution of the observables, but also as a function of the deuteron laboratory energy for fixed centre-of-mass angle. Comparison with data is sh...

  3. Measurements of {sup 67}Ga production cross section induced by protons on {sup nat}Zn in the low energy range from 1.678 to 2.444 MeV

    Energy Technology Data Exchange (ETDEWEB)

    Wachter, J.A., E-mail: javier.wachter@utem.cl [Departamento de Física, Facultad de Ciencias Naturales, Matemática y del Medio Ambiente, Universidad Tecnológica Metropolitana, Santiago 7800002 (Chile); Miranda, P.A. [Departamento de Física, Facultad de Ciencias Naturales, Matemática y del Medio Ambiente, Universidad Tecnológica Metropolitana, Santiago 7800002 (Chile); Morales, J.R.; Cancino, S.A. [Departamento de Física, Facultad de Ciencias, Universidad de Chile, Casilla 653, Santiago (Chile); Correa, R. [Departamento de Física, Facultad de Ciencias Naturales, Matemática y del Medio Ambiente, Universidad Tecnológica Metropolitana, Santiago 7800002 (Chile)

    2015-02-01

    The experimental production cross section for the reaction {sup nat}Zn(p,x){sup 67}Ga has been measured in the energy range from 1.678 to 2.444 MeV. The methodology used in this work is based on characteristic X-ray emitted after irradiation by the daughter nuclei that decays by electron capture (EC) and the use of a complementary PIXE experiment. By doing so, expressions needed to determine cross section values are simplified since experimental factors such as geometric setup and an detector efficiency are avoided. {sup 67}Ga is a radionuclide particularly suited for this method since it decays by electron capture in 100% and the subsequent characteristic X-ray emission is easily detected. Natural zinc targets were fabricated by PVD technique and afterwards their thicknesses were determined by Rutherford Backscattering Spectrometry. Cross sections measurements were carried out by using the Van de Graaff accelerator located at Faculty of Sciences, University of Chile. It was found that our data for the {sup nat}Zn(p,x){sup 67}Ga reaction are, in general, in good agreement when compared to existing experimental data and to those calculated ALICE/ASH nuclear code. On the other hand, values predicted by Talys-1.6 are showing systematically lower magnitudes than our measured data.

  4. Secondary electron emission of thin carbon foils under the impact of hydrogen atoms, ions and molecular ions, under energies within the MeV range; Multiplicite des electrons secondaires emis par des cibles minces de carbone sous l'impact de projectiles H0, H2+, H3+ d'energie de l'ordre du MeV

    Energy Technology Data Exchange (ETDEWEB)

    Vidovic, Z

    1997-06-15

    This work focuses on the study of the emission statistics of secondary electrons from thin carbon foils bombarded with H{sup 0}, H{sub 2}{sup +} and H{sub 3}{sup +} projectiles in the 0.25-2.2 MeV energy range. The phenomenon of secondary electron emission from solids under the impact of swift ions is mainly due to inelastic interactions with target electrons. The phenomenological and theoretical descriptions, as well as a summary of the main theoretical models are the subject of the first chapter. The experimental set-up used to measure event by event the electron emission of the two faces of a thin carbon foil traversed by an energetic projectile is described in the chapter two. In this chapter are also presented the method and algorithms used to process experimental spectra in order to obtain the statistical distribution of the emitted electrons. Chapter three presents the measurements of secondary electron emission induced by H atoms passing through thin carbon foils. The secondary electron yields are studied in correlation with the emergent projectile charge state. We show the peculiar role of the projectile electron, whether it remains or not bound to the incident proton. The fourth chapter is dedicated to the secondary electron emission induced by H{sub 2}{sup +} and H{sub 3}{sup +} polyatomic ions. The results are interpreted in terms of collective effects in the interactions of these ions with solids. The role of the proximity of the protons, molecular ion fragments, upon the amplitude of these collective effects is evidenced from the study of the statistics of forward emission. These experiences allowed us to shed light on various aspects of atom and polyatomic ion inter-actions with solid surfaces. (author)

  5. Report to the DOE nuclear data committee. [EV RANGE 10-100; CROSS SECTIONS; PHOTONEUTRONS; NEUTRONS; GAMMA RADIATION; COUPLED CHANNEL THEORY; DIFFERENTIAL CROSS SECTIONS; MEV RANGE 01-10; ; CAPTURE; GAMMA SPECTRA; THERMAL NEUTRONS; COMPUTER CALCULATIONS; DECAY; FISSION PRODUCTS; FISSION YIELD; SHELL MODELS; NUCLEAR DATA COLLECTIONS

    Energy Technology Data Exchange (ETDEWEB)

    Struble, G.L.; Haight, R.C.

    1981-03-01

    Topics covered include: studies of (n, charged particle) reactions with 14 to 15 MeV neutrons; photoneutron cross sections for /sup 15/N; neutron radiative capture; Lane-model analysis of (p,p) and (n,n) scattering on the even tin isotopes; neutron scattering cross sections for /sup 181/Ta, /sup 197/Au, /sup 209/Bi, /sup 232/Th, and /sup 238/U inferred from proton scattering and charge exchange cross sections; neutron-induced fission cross sections of /sup 245/Cm and /sup 242/Am; fission neutron multiplicities for /sup 245/Cm and /sup 242/Am; the transport of 14 MeV neutrons through heavy materials 150 < A < 208; /sup 249/Cm energy levels from measurement of thermal neutron capture gamma rays; /sup 231/Th energy levels from neutron capture gamma ray and conversion electron spectroscopy; new measurements of conversion electron binding energies in berkelium and californium; nuclear level densities; relative importance of statistical vs. valence neutron capture in the mass-90 region; determination of properties of short-lived fission products; fission yield of /sup 87/Br and /sup 137/I from 15 nuclei ranging from /sup 232/Th to /sup 249/Cf; evaluation of charged particle data for the ECPL library; evaluation of secondary charged-particle energy and angular distributions for ENDL; and evaluated nuclear structure libraries derived from the table of isotopes. (GHT)

  6. Spin-flip (p,n) reactions on /sup 26/Mg, /sup 54/Fe, and /sup 56/Fe at selected proton bombarding energies in the range of 17 to 25 MeV

    Energy Technology Data Exchange (ETDEWEB)

    Aron, D.L.

    1985-06-01

    New data are presented for the /sup 26/Mg(p,n)/sup 26/Al reaction at E/sub p/ = 19.12 and 24.97 MeV, for the /sup 54/Fe(p,n)/sup 54/Co reaction at E/sub p/ = 17.20, 18.60, and 24.60 MeV, and for the /sup 56/Fe(p,n)/sup 56/Co reaction at E/sub p/ = 19.12 and 24.59 MeV. Data were taken with the LLNL Cyclograaff at 16 angles from 3.5/sup 0/ to 159.0/sup 0/. A large detector at 23.8/sup 0/ with a long neutron flight path collected high resolution spectra. This large detector also collected separate 0/sup 0/ high resolution data on the /sup 26/Mg and /sup 56/Fe(p,n) reactions at E/sub p/ = 19 MeV. Absolute differential (p,n) cross sections were extracted for 1/sup +/ states in /sup 26/Al, /sup 54/Co, and /sup 56/Co, for the 0/sup +/ isobaric analong state (IAS) in /sup 54/Co and /sup 56/Co, for a 2/sup +/ state in each residual nucleus, and for the 0.199 MeV 7/sup +/ state of /sup 54/Co. No new experimental states were identified. Only relative cross sections were extracted at 0/sup 0/. Experimental angle-integrated cross sections were obtained for all but one state. DWBA79 was used, with the G-matrix effective nucleon-nucleon interaction of Bertsch et al. (with the central triplet-odd component V/sub to/ = O) and the Livermore shell model wave functions to calculate differential (p,n) cross sections to 1/sup +/ states and to the /sup 54/Co and /sup 56/Co IAS. Normalization of the DWBA angle-integrated cross sections to measurements for the /sup 54/Co and /sup 56/Co IAS (at E/sub p/ = 24.6 MeV) yielded the renormalized V/sub tau/ = 21.4 +- 2.1 MeV. Normalization of the DWBA angle-integrated cross sections to measurements for the 24.6 MeV /sup 54/Co and /sup 56/Co 1/sup +/ states, coupled with the normalization of the wave functions to previously experimentally determined GT strength, yield the renormalized V/sub sigmatau/ = 12.3 +- 1.2 MeV. The experimental Gamow-Teller strength B(GT)/sub exp./ of the T = 1 /sup 26/Al state at 9.44 MeV was found to be 0.69; B

  7. MeV fullerene impacts on mica

    Energy Technology Data Exchange (ETDEWEB)

    Doebeli, M.; Scandella, L. [Paul Scherrer Inst. (PSI), Villigen (Switzerland); Ames, F. [Eidgenoessische Technische Hochschule, Zurich (Switzerland)

    1997-09-01

    Hillock heights on mica irradiated with MeV C{sub 60} ions have been investigated systematically. Results show that the small range of secondary particles along the track plays a crucial role in defect production. (author) figs., tab., refs.

  8. Photofission cross-section ratio measurement of {sup 235}U/{sup 238}U using monoenergetic photons in the energy range of 9.0–16.6 MeV

    Energy Technology Data Exchange (ETDEWEB)

    Krishichayan, E-mail: krishi@tunl.duke.edu [Department of Physics, Duke University, Durham, NC 27708 (United States); Triangle Universities Nuclear Laboratory, Durham, NC 27708 (United States); Bhike, Megha; Finch, S.W.; Howell, C.R. [Department of Physics, Duke University, Durham, NC 27708 (United States); Triangle Universities Nuclear Laboratory, Durham, NC 27708 (United States); Tonchev, A.P. [Nuclear and Chemical Sciences Division, Lawrence Livermore National Laboratory, Livermore, CA 94550 (United States); Tornow, W. [Department of Physics, Duke University, Durham, NC 27708 (United States); Triangle Universities Nuclear Laboratory, Durham, NC 27708 (United States)

    2017-05-11

    Photofission cross-section ratios of {sup 235}U and {sup 238}U have been measured using monoenergetic photon beams at the HIγS facility of TUNL. These measurements have been performed in small energy steps between 9.0 and 16.6 MeV using a dual-fission ionization chamber. Measured cross-section ratios are compared with the previous experimental data as well as with the recent evaluated nuclear data library ENDF.

  9. Energy dependent response of the Fricke gel dosimeter prepared with 270 Bloom gelatine for photons in the energy range 13.93 keV-6 MeV

    Energy Technology Data Exchange (ETDEWEB)

    Cavinato, C.C. [Instituto de Pesquisas Energeticas e Nucleares, IPEN-CNEN/SP, Av. Prof. Lineu Prestes, 2242, Cidade Universitaria, 05508-000 Sao Paulo, SP (Brazil); Campos, L.L., E-mail: lcrodri@ipen.b [Instituto de Pesquisas Energeticas e Nucleares, IPEN-CNEN/SP, Av. Prof. Lineu Prestes, 2242, Cidade Universitaria, 05508-000 Sao Paulo, SP (Brazil)

    2010-07-21

    The spectrophotometric energy dependent response to photons with effective energies between 13.93 keV and 6 MeV of the Fricke xylenol gel (FXG) dosimeter developed at IPEN, prepared using 270 Bloom gelatine, was evaluated in order to verify the possible dosimeter application in other medicine areas in addition to radiosurgery, for example, breast radiotherapy and blood bags radiosterilization. Other dosimetric characteristics were also evaluated. The obtained results indicate that the FXG dosimeter can contribute to dosimetry in different medical application areas including magnetic resonance imaging (MRI) evaluation technique that permits three-dimensional (3D) dose distribution evaluation.

  10. The neutron cross-section functions for the reactions {sup 187}Re(n,α){sup 184}Ta, {sup 187}Re(n,2n){sup 186}Re and {sup 185}Re(n,2n){sup 184}Re in the energy range 13.08-19.5 MeV

    Energy Technology Data Exchange (ETDEWEB)

    Jovancevic, N. [Institute for Reference Materials and Measurements (IRMM), European Commission, Joint Research Centre, Geel (Belgium); University of Novi Sad, Department of Physics, Faculty of Sciences, Novi Sad (Serbia); Daraban, L.; Stroh, H.; Oberstedt, S.; Hult, M.; Bonaldi, C.; Geerts, W.; Hambsch, F.J.; Lutter, G.; Marissens, G.; Vidali, M. [Institute for Reference Materials and Measurements (IRMM), European Commission, Joint Research Centre, Geel (Belgium)

    2016-05-15

    In the present work, measurements of the cross-section functions for the {sup 187}Re(n,α){sup 184}Ta, {sup 187}Re(n,2n){sup 186}Re and {sup 185}Re(n,2n){sup 184}Re reactions were performed in the energy range 13.08-19.5 MeV. We applied the neutron activation technique using several wide-energy neutron beams (NAXSUN), recently developed at the JRC-IRMM. This method involves measuring the activity of the radionuclides produced in a target by the in energy overlapping neutron beams and a subsequent unfolding procedure. The present results are the first experimental data on these cross-sections for incident neutron energies between 15 and 19.5 MeV and may contribute to improving evaluations and nuclear models. (orig.)

  11. Energy dependence of effective atomic numbers for photon energy absorption and photon interaction: Studies of some biological molecules in the energy range 1 keV-20 MeV

    DEFF Research Database (Denmark)

    Manohara, S.R.; Hanagodimath, S.M.; Gerward, Leif

    2008-01-01

    , linolenic, arachidonic, and arachidic acids), nucleotide bases (adenine, guanine, cytosine, uracil, and thymine), and carbohydrates (glucose, sucrose, raffinose, and starch). The Z(PEA, eff) and Z(PI, eff) values have been found to change with energy and composition of the biological molecules. The energy......Effective atomic numbers for photon energy absorption, Z(PEA,eff), and for photon interaction, Z(PI,eff), have been calculated by a direct method in the photon-energy region from 1 keV to 20 MeV for biological molecules, such as fatty acids (lauric, myristic, palmitic, stearic, oleic, linoleic...... dependence of the mass attenuation coefficient, Z(PEA, eff), and the mass energy-absorption coefficient, Z(PI, eff), is shown graphically and in tabular form. Significant differences of 17%-38% between Z(PI, eff) and Z(PEA, eff) occur in the energy region 5-100 keV. The reasons for these differences...

  12. Cross sections for (n, 2n), (n, p) and (n, ) reactions on osmium isotopes in the neutron energy range of 13.5-14.8 MeV

    Energy Technology Data Exchange (ETDEWEB)

    Zhao Liangyong; Yuan Jilong; Tuo Fei; Zhang Yanbin [Institute of Nuclear Science and Technology, Lanzhou University, Lanzhou, Gansu Province 730000 (China); Kong Xiangzhong [Institute of Nuclear Science and Technology, Lanzhou University, Lanzhou, Gansu Province 730000 (China)], E-mail: kongxz@lzu.edu.cn; Liu Rong; Jiang Li [Institute of Nuclear Physics and Chemistry, China Academy of Engineering Physics, Mianyang, Sichuan Province 621900 (China)

    2008-10-15

    Cross sections for (n, 2n), (n, p) and (n, ) reactions on the osmium isotopes were measured in the neutron energies 13.5-14.8 MeV by the activation technique with the monitor reaction {sup 93}Nb(n, 2n){sup 92m}Nb. Our measurements were carried out by {gamma}-detection using a coaxial high-purity germanium (HPGe) detector. Natural high-purity osmium powder (99.9%) was fabricated as the samples. The neutron energies were determined by the cross-section ratios for {sup 93}Nb(n, 2n){sup 92m}Nb and {sup 90}Zr(n, 2n){sup 89m+g}Zr reactions. The fast neutrons were produced by the T(d, n){sup 4}He reaction. The results obtained were compared with previous data.

  13. Measurement of the 234U(n, f ) cross-section with quasi-monoenergetic beams in the keV and MeV range using a Micromegas detector assembly

    Science.gov (United States)

    Stamatopoulos, A.; Kanellakopoulos, A.; Kalamara, A.; Diakaki, M.; Tsinganis, A.; Kokkoris, M.; Michalopoulou, V.; Axiotis, M.; Lagoyiannis, A.; Vlastou, R.

    2018-01-01

    The 234U neutron-induced fission cross-section has been measured at incident neutron energies of 452, 550, 651 keV and 7.5, 8.7, 10 MeV using the 7Li ( p, n) and the 2H( d, n) reactions, respectively, relative to the 235U( n, f ) and 238U( n, f ) reference reactions. The measurement was performed at the neutron beam facility of the National Center for Scientific Research "Demokritos", using a set-up based on Micromegas detectors. The active mass of the actinide samples and the corresponding impurities were determined via α-spectroscopy using a surface barrier silicon detector. The neutron spectra intercepted by the actinide samples have been thoroughly studied by coupling the NeuSDesc and MCNP5 codes, taking into account the energy and angular straggling of the primary ion beams in the neutron source targets in addition to contributions from competing reactions ( e.g. deuteron break-up) and neutron scattering in the surrounding materials. Auxiliary Monte Carlo simulations were performed making combined use of the FLUKA and GEF codes, focusing particularly on the determination of the fission fragment detection efficiency. The developed methodology and the final results are presented.

  14. Neutron photoproduction in sup 2 sup 3 sup 2 Th and sup 2 sup 3 sup 8 U using thermal neutron capture gamma-rays in the energy range 5.61 to 10.83 MeV

    CERN Document Server

    Goncalez, O L

    1998-01-01

    Neutron photoproduction studies for sup 2 sup 3 sup 2 Th and sup 2 sup 3 sup 8 U were carried out from 5.6 to 10.8 MeV, using neutron capture gamma-rays with high resolution in energy (3 to 21 eV), produced by 30 target materials, placed inside a tangential beam port, near the core of the IPEN/CNEN-SP IEA-R1 2 MW research reactor. The samples (17.76 g of U sub 3 sub O sub 8 depleted to 0.349% in sup 2 sup 3 sup 5 U and 19.93 g of natural Th O sub 2) have been irradiated inside a 4 pi geometry neutron detector system sup L ong Counter sup , 520.5 cm away from the capture target. The capture gamma-ray flux was determined by means of the analysis of the gamma spectrum obtained by using a Ge(Li) solid-state detector (E G and G Ortec, 25 cm sup 3 , 5%), previously calibrated with capture gamma-rays from a standard target of Nitrogen (Melamine). The neutron photoproduction cross section has been measured for each target capture gamma-ray spectrum (compound cross section). A methodology for unfolding the set of expe...

  15. Excitation functions of proton-induced reactions on natural Nd in the 10-30 MeV energy range, and production of radionuclides relevant for double-β decay

    Science.gov (United States)

    Lebeda, O.; Lozza, V.; Schrock, P.; Štursa, J.; Zuber, K.

    2012-01-01

    A preferred candidate for neutrinoless double-β decay, 150Nd, is present in natural neodymium at an abundance level of 5.64%. However, neodymium could be activated by cosmic rays during the period it spends on the Earth's surface. Its activation by protons is therefore of interest when it comes to estimating the possible disturbance effects and increased background during neutrinoless double-β-decay experiments like Sudbury Neutrino Observatory plus liquid scintillator (SNO+). In most cases, we lack experimental data on proton-induced reactions on neodymium. Therefore, a measurement of cross sections has been performed for the formation of 141Pm, 143Pm, 144Pm, 146Pm, 148Pm, 148Pmm, 149Pm, 150Pm, 140Nd, 141Nd, 147Nd, 149Nd, 138Prm, 139Pr, 142Pr, and 139Ce by 10-30 MeV protons. Oxidation-protected metal foil targets of natural isotopic abundance were irradiated by the usual stacked-foil technique on the external proton beam of the isochronous cyclotron U-120M at the Nuclear Physics Institute at Řež near Prague. Special attention was paid to the excitation functions of long-lived radionuclides. The measured data were compared with TENDL-2010 library data (talys code).

  16. Ion emission in solids bombarded with Au{sub n}{sup +} (n = 1 - 9) clusters accelerated within the 0.15 - 1.25 MeV energy range; Emission ionique des solides a l'impact d'agregats Au{sub n}{sup +} (n=1-9) acceleres entre 0,15 et 1,25 MeV

    Energy Technology Data Exchange (ETDEWEB)

    Wehbe, Nimer [Universite Claude Bernard Lyon-I, 43 boulevard du 11 Novembre 1918, 69622 Villeurbanne cedex (France)

    2006-06-15

    This experimental work is devoted to the study of the ion emission in solids at the impact of gold clusters of energies within 0.15 to 1.25 MeV range. The physics of ion-solid collisions and the theoretical models of sputtering of solids under ion bombardment are presented in the first chapter. The chapter no. 2 deals with the description of the experimental setup. The study of a gold target allowed to evidence the role of the size and energy of the clusters in determining the emission intensity and the mass distribution of the ions. The 4. chapter gives results from the study of cesium iodide in which the intense emission of CsI clusters could be investigated quantitatively due to multiplicity measurements. Finally, the chapter no. 5 was devoted to the study of a biologic molecule, the phenylalanine, and of a pesticide molecule, chlorosulfuron. This work evidenced the importance of clusters for surface analyses by mass spectrometry.

  17. Technical note: Influence of the phantom material on the absorbed-dose energy dependence of the EBT3 radiochromic film for photons in the energy range 3 keV-18 MeV.

    Science.gov (United States)

    Hermida-López, M; Lüdemann, L; Flühs, A; Brualla, L

    2014-11-01

    Water is the reference medium for radiation therapy dosimetry, but for film dosimetry it is more practical to use a solid phantom. As the composition of solid phantoms differs from that of water, the energy dependence of film exposed within solid phantoms may also differ. The energy dependence of a radiochromic film for a given beam quality Q (energy for monoenergetic beams) has two components: the intrinsic energy dependence and the absorbed-dose energy dependence f(Q), the latter of which can be calculated through a Monte Carlo simulation of radiation transport. The authors used Monte Carlo simulations to study the influence of the phantom material on the f(Q) of the EBT3 radiochromic film (Ashland Specialty Ingredients, Wayne, NJ) for photon beams with energies between 3 keV and 18 MeV. All simulations were carried out with the general-purpose Monte Carlo code penelope 2011. The geometrical model consisted of a cylindrical phantom, with the film positioned at different depths depending on the initial photon energy. The authors simulated monoenergetic parallel photon beams and x-ray beams from a superficial therapy system. To validate their choice of simulation parameters, they also calculated f(Q) for older film models, EBT and EBT2, comparing with published results. In addition to water, they calculated f(Q) of the EBT3 film for solid phantom materials commonly used for film dosimetry: RW1 and RW3 (PTW-Freiburg, Freiburg, Germany), Solid Water (Gammex-RMI, Madison, WI), and PMMA. Finally, they combined their calculated f(Q) with published overall energy response data to obtain the intrinsic energy dependence of the EBT3 film in water. The calculated f(Q) for EBT and EBT2 films was statistically compatible with previously published data. Between 10 keV and 18 MeV, the variation found in f(Q) of the EBT3 film for water was within 2.3%, with a standard statistical uncertainty less than 1%. If the quantity dose-to-water in the phantom is considered, which is the

  18. Technical Note: Influence of the phantom material on the absorbed-dose energy dependence of the EBT3 radiochromic film for photons in the energy range 3 keV–18 MeV

    Energy Technology Data Exchange (ETDEWEB)

    Hermida-López, M., E-mail: mhermida@vhebron.net [NCTeam, Strahlenklinik, Universitätsklinikum Essen, Hufelandstraße 55, Essen D-45122, Germany and Servei de Física i Protecció Radiològica, Hospital Universitari Vall d’Hebron, Pg. Vall d’Hebron 119-129, Barcelona 08035 (Spain); Lüdemann, L.; Flühs, A. [Medical Physics, Strahlenklinik, Universitätsklinikum Essen, Hufelandstraße 55, Essen D-45122 (Germany); Brualla, L. [NCTeam, Strahlenklinik, Universitätsklinikum Essen, Hufelandstraße 55, Essen D-45122 (Germany)

    2014-11-01

    Purpose: Water is the reference medium for radiation therapy dosimetry, but for film dosimetry it is more practical to use a solid phantom. As the composition of solid phantoms differs from that of water, the energy dependence of film exposed within solid phantoms may also differ. The energy dependence of a radiochromic film for a given beam quality Q (energy for monoenergetic beams) has two components: the intrinsic energy dependence and the absorbed-dose energy dependence f(Q), the latter of which can be calculated through a Monte Carlo simulation of radiation transport. The authors used Monte Carlo simulations to study the influence of the phantom material on the f(Q) of the EBT3 radiochromic film (Ashland Specialty Ingredients, Wayne, NJ) for photon beams with energies between 3 keV and 18 MeV. Methods: All simulations were carried out with the general-purpose Monte Carlo code PENELOPE 2011. The geometrical model consisted of a cylindrical phantom, with the film positioned at different depths depending on the initial photon energy. The authors simulated monoenergetic parallel photon beams and x-ray beams from a superficial therapy system. To validate their choice of simulation parameters, they also calculated f(Q) for older film models, EBT and EBT2, comparing with published results. In addition to water, they calculated f(Q) of the EBT3 film for solid phantom materials commonly used for film dosimetry: RW1 and RW3 (PTW-Freiburg, Freiburg, Germany), Solid Water (Gammex-RMI, Madison, WI), and PMMA. Finally, they combined their calculated f(Q) with published overall energy response data to obtain the intrinsic energy dependence of the EBT3 film in water. Results: The calculated f(Q) for EBT and EBT2 films was statistically compatible with previously published data. Between 10 keV and 18 MeV, the variation found in f(Q) of the EBT3 film for water was within 2.3%, with a standard statistical uncertainty less than 1%. If the quantity dose-to-water in the phantom is

  19. Neutron-induced fission cross-section measurement of 234U with quasi-monoenergetic beams in the keV and MeV range using micromegas detectors

    Science.gov (United States)

    Tsinganis, A.; Kokkoris, M.; Vlastou, R.; Kalamara, A.; Stamatopoulos, A.; Kanellakopoulos, A.; Lagoyannis, A.; Axiotis, M.

    2017-09-01

    Accurate data on neutron-induced fission cross-sections of actinides are essential for the design of advanced nuclear reactors based either on fast neutron spectra or alternative fuel cycles, as well as for the reduction of safety margins of existing and future conventional facilities. The fission cross-section of 234U was measured at incident neutron energies of 560 and 660 keV and 7.5 MeV with a setup based on `microbulk' Micromegas detectors and the same samples previously used for the measurement performed at the CERN n_TOF facility (Karadimos et al., 2014). The 235U fission cross-section was used as reference. The (quasi-)monoenergetic neutron beams were produced via the 7Li(p,n) and the 2H(d,n) reactions at the neutron beam facility of the Institute of Nuclear and Particle Physics at the `Demokritos' National Centre for Scientific Research. A detailed study of the neutron spectra produced in the targets and intercepted by the samples was performed coupling the NeuSDesc and MCNPX codes, taking into account the energy spread, energy loss and angular straggling of the beam ions in the target assemblies, as well as contributions from competing reactions and neutron scattering in the experimental setup. Auxiliary Monte-Carlo simulations were performed with the FLUKA code to study the behaviour of the detectors, focusing particularly on the reproduction of the pulse height spectra of α-particles and fission fragments (using distributions produced with the GEF code) for the evaluation of the detector efficiency. An overview of the developed methodology and preliminary results are presented.

  20. Within the framework of the new fuel cycle {sup 232}Th/{sup 233}U, determination of the {sup 233}Pa(n.{gamma}) radiative capture cross section for neutron energies ranging between 0 and 1 MeV; Dans le cadre du nouveau cycle de combustible {sup 232}Th/{sup 233}U, determination de la section efficace de capture radiative {sup 233}Pa(n,{gamma}) pour des energies de neutrons comprises entre 0 et 1 MeV

    Energy Technology Data Exchange (ETDEWEB)

    Boyer, S

    2004-10-15

    The Thorium cycle Th{sup 232}/U{sup 233} may face brilliant perspectives through advanced concepts like molten salt reactors or accelerator driven systems but it lacks accurate nuclear data concerning some nuclei. Pa{sup 233} is one of these nuclei, its high activity makes the direct measurement of its radiative neutron capture cross-section almost impossible. This difficulty has been evaded by considering the transfer reaction Th{sup 232}(He{sup 3},p)Pa{sup 234}* in which the Pa{sup 234} nucleus is produced in various excited states according to the amount of energy available in the reaction. The first chapter deals with the thorium cycle and its assets to contribute to the quenching of the fast growing world energy demand. The second chapter gives a detailed description of the experimental setting. A scintillation detector based on deuterated benzene (C{sub 6}D{sub 6}) has been used to counter gamma ray cascades. The third chapter is dedicated to data analysis. In the last chapter we compare our experimental results with ENDF and JENDL data and with computed values from 2 statistical models in the 0-1 MeV neutron energy range. Our results disagree clearly with evaluated data: our values are always above ENDF and JENDL data but tend to near computed values. We have also perform the measurement of the radiative neutron cross-section of Pa{sup 231} for a 110 keV neutron: {sigma}(n,{gamma}) 2.00 {+-} 0.14 barn. (A.C.)

  1. Gamma-Light: High-Energy Astrophysics above 10 MeV

    DEFF Research Database (Denmark)

    Morselli, Aldo; Argan, Andrea; Barbiellini, Guido

    2013-01-01

    The energy range between 10 and 50 MeV is an experimentally very difficult range and remained uncovered since the time of COMPTEL. Here we propose a possible mission to cover this energy range.......The energy range between 10 and 50 MeV is an experimentally very difficult range and remained uncovered since the time of COMPTEL. Here we propose a possible mission to cover this energy range....

  2. The JHP 200-MeV proton linear accelerator

    Energy Technology Data Exchange (ETDEWEB)

    Kato, Takao [National Lab. for High Energy Physics, Tsukuba, Ibaraki (Japan)

    1997-11-01

    A 200-MeV proton linear accelerator for the Japanese Hadron Project (JHP) has been designed. It consists of a 3-MeV radio-frequency quadrupole linac (RFQ), a 50-MeV drift tube linac (DTL) and a 200-MeV separated-type drift tube linac (SDTL). A frequency of 324 MHz has been chosen for all of the rf structures. A peak current of 30 mA (H{sup -} ions) of 400 {mu}sec pulse duration will be accelerated at a repetition rate of 25 Hz. A future upgrade plan up to 400 MeV is also presented, in which annular-coupled structures (ACS) of 972 MHz are used in an energy range of above 150 or 200 MeV. One of the design features is its high performance for a beam-loss problem during acceleration. It can be achieved by separating the transition point in the transverse motion from that of the longitudinal motion. The transverse transition at a rather low-energy range decreases the effects of space-charge, while the longitudinal transition at a rather high-energy range decreases the effects of nonlinear problems related to acceleration in the ACS. Coupled envelope equations and equipartitioning theory are used for the focusing design. The adoption of the SDTL structure improves both the effective shunt impedance and difficulties in fabricating drift tubes with focusing magnets. An accurate beam-simulation code on a parallel supercomputer was used for confirming any beam-loss problem during acceleration. (author)

  3. np scattering measurements at 96 MeV

    NARCIS (Netherlands)

    Rahm, J; Blomgren, J; Conde, H; Dangtip, S; Elmgren, K; Olsson, N; Ronnqvist, T; Zorro, R; Jonsson, O; Nilsson, L; Renberg, PU; Ringbom, A; Tibell, G; van der Werf, SY; Ericson, TEO; Loiseau, B; Olson, N.; Rönnqvist, T.; Tiebell, G.

    The differential np scattering cross section has been measured at 96 MeV in the angular range theta (c.m.) =74-180 degrees at the neutron beam facility of the The Svedberg Laboratory in Uppsala. A subset of the data, covering 116-180 degrees, has previously been published. The new, extended angular

  4. Differential cross section measurements of {sup 27}Al(p,p{sup /}γ){sup 27}Al and {sup 27}Al(p,αγ){sup 24}Mg reactions in the energy range of 1.6–3.0 MeV

    Energy Technology Data Exchange (ETDEWEB)

    Jokar, A., E-mail: arezajokar@gmail.com [Physics & Accelerators Research School, NSTRI, PO Box 14395-836, Tehran (Iran, Islamic Republic of); Kakuee, O.; Lamehi-Rachti, M. [Physics & Accelerators Research School, NSTRI, PO Box 14395-836, Tehran (Iran, Islamic Republic of); Sharifzadeh, N. [Payame Noor University, PO Box 19395-13697, Tehran (Iran, Islamic Republic of); Fathollahi, V. [Physics & Accelerators Research School, NSTRI, PO Box 14395-836, Tehran (Iran, Islamic Republic of)

    2015-11-01

    In this work measurement of differential cross sections of {sup 27}Al(p,p{sup /}γ){sup 27}Al (E{sub γ} = 844, 1014 keV) and {sup 27}Al(p,αγ){sup 24}Mg (E{sub γ} = 1369 keV) nuclear reactions in the proton energy range of 1.6–3.0 MeV are described and the measured values are presented. Thin Al target was prepared by evaporating a 26 μg/cm{sup 2} Al onto a 129 μg/cm{sup 2} self-supporting Ag film. The gamma-rays and backscattered protons were detected simultaneously. The gamma-rays and protons were collected by an HPGe detector placed at an angle of 90° with respect to beam direction and an ion implanted Si detector placed at a scattering angle of 165°, respectively. In this experimental setup the great advantage is that differential cross sections could be independent on absolute values of the collected beam charge. The overall systematic uncertainty of cross sections was estimated to be ±9% while statistical errors were less than ±5%.

  5. Injection of electrons and protons with energies of tens of MeV into L less than 3 on 24 March 1991

    Science.gov (United States)

    Blake, J. B.; Kolasinski, W. A.; Fillius, R. W.; Mullen, E. G.

    1992-01-01

    On 24 March 1991 instrumentation aboard CRRES observed the almost instantaneous injection of electrons and protons with energies above 15 MeV into the L-region in the range 2-3. The energy spectrum of the injected electrons, a power law (E exp -6) peaked at 15 MeV and continued to at least 50 MeV.

  6. VERIFIKASI PERCENTAGE DEPTH DOSE (PDD) DAN PROFILE DOSE PESAWAT LINEAR ACCELERATOR (LINAC) BERKAS ELEKTRON 6 MeV, 9 MeV, 12 MeV DAN 15 MeV MENGGUNAKAN WATER PHANTOM

    OpenAIRE

    Marten Padang, Jumedi

    2015-01-01

    Abstrak Telah dilakukan penelitian tentang Verifikasi Percentage Depth Dose (PDD) dan Profile Dose Pesawat Linear Accelerator (LINAC) Berkas Elektron 6 MeV, 9 MeV, 12 MeV dan 15 MeV Menggunakan Water Phantom. Penelitian ini bertujuan untuk menganalisis Percentage Depth Dose (PDD) dan Profile Dose pesawat linac jenis HCX 5640 berkas elektron 6 MeV, 9 MeV, 12 MeV dan 15 MeV untuk luas lapangan 10 x 10 cm2. Penelitian ini membandingkan data acuan yang telah ada sebelumnya dan data yang dipero...

  7. Neutron-induced fission cross section of 242Pu from 15 MeV to 20 MeV

    Directory of Open Access Journals (Sweden)

    Jovančević N.

    2017-01-01

    Full Text Available Accurate nuclear-data needs in the fast-neutron-energy region have been recently addressed for the development of next generation nuclear power plants (GEN-IV by the OECD Nuclear Energy Agency (NEA. This sensitivity study has shown that of particular interest is the 242Pu(n,f cross section for fast reactor systems. Measurements have been performed with quasi-monoenergetic neutrons in the energy range from 15 MeV to 20 MeV produced by the Van de Graaff accelerator of the JRC-Geel. A twin Frisch-grid ionization chamber has been used in a back-to-back configuration as fission fragment detector. The 242Pu(n,f cross section has been normalized to 238U(n,f cross section data. The results were compared with existing literature data and show acceptable agreement within 5%.

  8. Neutron-induced fission cross section of 242Pu from 15 MeV to 20 MeV

    Science.gov (United States)

    Jovančević, N.; Salvador-Castineira, P.; Daraban, L.; Vidali, M.; Heyse, J.; Oberstedt, S.; Hambsch, F.-J.; Bonaldi, C.; Geerts, W.

    2017-09-01

    Accurate nuclear-data needs in the fast-neutron-energy region have been recently addressed for the development of next generation nuclear power plants (GEN-IV) by the OECD Nuclear Energy Agency (NEA). This sensitivity study has shown that of particular interest is the 242Pu(n,f) cross section for fast reactor systems. Measurements have been performed with quasi-monoenergetic neutrons in the energy range from 15 MeV to 20 MeV produced by the Van de Graaff accelerator of the JRC-Geel. A twin Frisch-grid ionization chamber has been used in a back-to-back configuration as fission fragment detector. The 242Pu(n,f) cross section has been normalized to 238U(n,f) cross section data. The results were compared with existing literature data and show acceptable agreement within 5%.

  9. Low energy pion production by 400 to 500 MeV protons

    Energy Technology Data Exchange (ETDEWEB)

    Bryman, D.; Beer, G.; Mason, G.R.; Mathie, E.; Olin, A.; Robertson, L.P.; Vincent, J.S.

    1976-01-01

    Using TRIUMF proton beams of 400- to 500-MeV bombarding carbon and copper targets we have measured positive pion production cross sections for pion energies 20 to 100 MeV and pion angles 60 to 150/sup 0/. The pions were stopped in a range telescope in which time-of-flight, energy loss, and the detection of the pion decay were used for particle identification.

  10. Stopping Power of Al, Cu, Ag, Au, Pb, and U for 5-18-MeV Protons and Deuterons

    DEFF Research Database (Denmark)

    Sørensen, H.; Andersen, Hans Henrik

    1973-01-01

    High energy protons and deuterons of energies between 9 and 18 MeV have been used to extend earlier measurements of the stopping power of Al, Cu, Ag and Au and the stopping powers of Pb and U in the range 5-18 MeV have been determined for the first time. Mean excitation potentials have been...

  11. Evidence for two narrow pp resonances at 2020 MeV and 2200 MeV

    CERN Document Server

    Benkheiri, P; Bouquet, B; Briandet, P; D'Almagne, B; Dang-Vu, C; De Rosny, G; Eisenstein, B I; Ferrer, A; Fleury, P; Grossetête, B; Irwin, G; Jacholkowski, A; Lahellec, A; Nguyen, H; Petroff, P; Richard, F; Rivet, P; Roudeau, P; Rougé, A; Rumpf, M; Six, J; Thénard, J M; Treille, D; Volte, A; Yaffe, D; Yiou, T P; Yoshida, H

    1977-01-01

    From the study of the reaction pi /sup -/p to p/sub F/pp pi /sup -/ using a fast proton (p/sub F/) trigger device in the CERN Omega spectrometer, the authors find evidence for two narrow pp states produced mainly in association with a Delta degrees (1232) and a N degrees (1520). The statistical significance of each peak is greater than 6 standard deviations. Masses and natural widths of these resonances are respectively M/sub 1/=2020+or-3 MeV, Gamma /sub 1 /=24+or-12 MeV and M/sub 2/=2204+or-5 MeV, Gamma /sub 2/=16/sub -16 //sup +20/ MeV. The data are consistent with a small production of the narrow approximately 1935 MeV resonance already reported. Production cross sections for these new pp resonances are given. (8 refs).

  12. <50> MeV transfer line

    CERN Multimedia

    CERN PhotoLab

    1972-01-01

    Measurement equipment around the 50 MeV transfer line from linac to booster. The vacuum pipe in the centre, with a temporary beam stopper in the foreground, leads to booster injection equipment. On the left is a spectrometer to determine energy spread, and in the right-hand line apparatus for emittance measurement.

  13. <600> MeV synchro-cyclotron

    CERN Multimedia

    CERN PhotoLab

    1971-01-01

    One of the 14 pancakes of the new magnet coils for the 600 MeV synchro-cyclotron which were wound and coated with epoxy resin on the CERN site. These new coils will replace the present ones which have been in use for more than 14 years but are now showing signs of deteriorations.

  14. Annealing behaviour of MeV erbium implanted lithium niobate

    Energy Technology Data Exchange (ETDEWEB)

    Gortmaker, P.; McCallum, J.C. [Royal Melbourne Inst. of Tech., VIC (Australia)

    1993-12-31

    Lithium niobate (LiNbO{sub 3}) is a crystalline ceramic commonly used in the fabrication of optoelectronic devices. Recently, rare earth doping of LiNbO{sub 3} has become a topic of particular interest. The electronic configuration of rare earth elements such as Erbium (Er) and Neodymium (Nd) allows them to lase in nearly any host matrix making fabrication of a whole range of new optoelectronic devices possible. At present, the doping technique, for LiNbO{sub 3} are centred upon diffusion technology, but the diffusion profiles for the rare earths are not generally well-matched to the optical modes of the device. The aim of this research is to develop MeV implantation and annealing conditions of rare earth doped LiNbO{sub 3} that would be compatible with optoelectronic device fabrication. To determine the characteristics of the rare earth elements in the LiNbO{sub 3} host material over the depth range of interest in optoelectronic device applications, high energy Rutherford backscattering spectrometry and ion channeling (RBS-C) must be used. Presented here are the Er depth profile and lattice damage results obtained from 5 MeV RBS-C measurements on samples of LiNbO{sub 3} implanted with various doses of MeV Erbium and subsequently thermally annealed at a temperature of 1000 deg C. It was found that there is a peak implant concentration (2 x 10{sup 16} Er/cm{sup 2}) for which erbium no longer goes substitutional in the lattice, and the implantation damage is not fully removed by annealing. 8 refs., 3 figs.

  15. Measurement of (n,Xn) reaction cross sections at 96 MeV; Measure des sections efficaces (n,Xn) a 96 MeV

    Energy Technology Data Exchange (ETDEWEB)

    Sagrado Garcia, Melle Inmaculada C. [Ecole Doctorale: SINEM, U.F.R. de Sciences, Universite de Caen/Basse-Normandie, Esplanade Paix14000 Caen (France)

    2006-10-15

    Nucleon induced reactions in the 20-200 MeV energy range are intensively studied since a long time. The evaporation and the pre-equilibrium processes correspond to an important contribution of the production cross section in these reactions. Several theoretical approaches have been proposed and their predictions must be tested. The experimental results shown in this work are the only complete set of data for the (n,Xn) reactions in this energy range. Neutron double differential cross section measurements using lead and iron targets for an incident neutron beam at 96 MeV were carried out at TSL Laboratory in Uppsala, Sweden. The measurements have been performed for the first time with an energy threshold of 2 MeV and for a wide angular range (15 angle - 98 angle). Neutrons have been detected using two independent setups, DECOI and DEMON and CLODIA and SCANDAL, in order to cover the whole energy range (2-100) MeV. The angular distributions, the differential cross sections and the total inelastic production cross sections have been calculated using the double differential cross sections. The comparison between the experimental data and the predictions given by two of the most popular simulation codes, GEANT3 and MCNPX, have been performed, as well as the comparison with the predictions of the microscopic simulation model DYWAN, selected for its treatment of nucleon-nucleon reactions. (author)

  16. Advancing the MeV Frontier with AMEGO

    Science.gov (United States)

    Hartmann, Dieter; AMEGO

    2018-01-01

    The All-sky Medium Energy Gamma-ray Observatory (AMEGO) is a wide field of view instrument (~60 deg radius) with a broad energy range (~200 keV to >10 GeV) and excellent continuum sensitivity, designed to address a broad range of astrophsical topics in this under-explored region of the em-spectrum. AMEGO will also serve as a facility in the search for gamma-ray emission associated with gravitational wave producing compact object mergers. We describe the technical capabilities of AMEGO and discuss how it will advance our understanding of many source classes for which the peak of the power spectrum falls into the MeV band. The transition from thermal to non-thermal physics is explored in this window through observations of gamma-ray burst, supernovae, novae, supernova remnants, diffuse emission from radioactivities and cosmic-ray ISM interactions in our galaxy, and active galaxies. Dark matter studies will be addressed with observations of the galactic halo and nearby dwarf galaxies. The diffuse galactic background in the MeV regime remains to be fully characterized and resolved by source class. AMEGO aims at breakthroughs in all these arenas.

  17. Measurement of neutron-induced fission cross-sections of Th232, U238, U233 and Np237 relative to U235 from 1 MeV to 200 MeV

    Energy Technology Data Exchange (ETDEWEB)

    Shcherbakov, O.A.; Laptev, A.B.; Petrov, G.A. [Petersburg Nuclear Physics Inst., Gatchina, Leningrad district (Russian Federation); Fomichev, A.V.; Donets, A.Y.; Osetrov, O.I.

    1998-11-01

    The measurements of neutron-induced cross-section ratios for Th232, U238, U233 and Np237 relative to U235 have been carried out in the energy range from 1 MeV up to 200 MeV using the neutron time-of-flight spectrometer GNEIS based on 1 GeV proton synchrocyclotron. Below 20 MeV, the results of present measurements are roughly in agreement with evaluated data though there are some discrepances to be resolved. (author)

  18. Optimisation of 12 MeV electron beam simulation using variance reduction technique

    Science.gov (United States)

    Jayamani, J.; Termizi, N. A. S. Mohd; Kamarulzaman, F. N. Mohd; Aziz, M. Z. Abdul

    2017-05-01

    Monte Carlo (MC) simulation for electron beam radiotherapy consumes a long computation time. An algorithm called variance reduction technique (VRT) in MC was implemented to speed up this duration. This work focused on optimisation of VRT parameter which refers to electron range rejection and particle history. EGSnrc MC source code was used to simulate (BEAMnrc code) and validate (DOSXYZnrc code) the Siemens Primus linear accelerator model with the non-VRT parameter. The validated MC model simulation was repeated by applying VRT parameter (electron range rejection) that controlled by global electron cut-off energy 1,2 and 5 MeV using 20 × 107 particle history. 5 MeV range rejection generated the fastest MC simulation with 50% reduction in computation time compared to non-VRT simulation. Thus, 5 MeV electron range rejection utilized in particle history analysis ranged from 7.5 × 107 to 20 × 107. In this study, 5 MeV electron cut-off with 10 × 107 particle history, the simulation was four times faster than non-VRT calculation with 1% deviation. Proper understanding and use of VRT can significantly reduce MC electron beam calculation duration at the same time preserving its accuracy.

  19. Upper limit on the inner radiation belt MeV electron intensity

    Science.gov (United States)

    Li, X; Selesnick, RS; Baker, DN; Jaynes, AN; Kanekal, SG; Schiller, Q; Blum, L; Fennell, J; Blake, JB

    2015-01-01

    No instruments in the inner radiation belt are immune from the unforgiving penetration of the highly energetic protons (tens of MeV to GeV). The inner belt proton flux level, however, is relatively stable; thus, for any given instrument, the proton contamination often leads to a certain background noise. Measurements from the Relativistic Electron and Proton Telescope integrated little experiment on board Colorado Student Space Weather Experiment CubeSat, in a low Earth orbit, clearly demonstrate that there exist sub-MeV electrons in the inner belt because their flux level is orders of magnitude higher than the background, while higher-energy electron (>1.6 MeV) measurements cannot be distinguished from the background. Detailed analysis of high-quality measurements from the Relativistic Electron and Proton Telescope on board Van Allen Probes, in a geo-transfer-like orbit, provides, for the first time, quantified upper limits on MeV electron fluxes in various energy ranges in the inner belt. These upper limits are rather different from flux levels in the AE8 and AE9 models, which were developed based on older data sources. For 1.7, 2.5, and 3.3 MeV electrons, the upper limits are about 1 order of magnitude lower than predicted model fluxes. The implication of this difference is profound in that unless there are extreme solar wind conditions, which have not happened yet since the launch of Van Allen Probes, significant enhancements of MeV electrons do not occur in the inner belt even though such enhancements are commonly seen in the outer belt. Key Points Quantified upper limit of MeV electrons in the inner belt Actual MeV electron intensity likely much lower than the upper limit More detailed understanding of relativistic electrons in the magnetosphere PMID:26167446

  20. Upper limit on the inner radiation belt MeV electron intensity.

    Science.gov (United States)

    Li, X; Selesnick, R S; Baker, D N; Jaynes, A N; Kanekal, S G; Schiller, Q; Blum, L; Fennell, J; Blake, J B

    2015-02-01

    No instruments in the inner radiation belt are immune from the unforgiving penetration of the highly energetic protons (tens of MeV to GeV). The inner belt proton flux level, however, is relatively stable; thus, for any given instrument, the proton contamination often leads to a certain background noise. Measurements from the Relativistic Electron and Proton Telescope integrated little experiment on board Colorado Student Space Weather Experiment CubeSat, in a low Earth orbit, clearly demonstrate that there exist sub-MeV electrons in the inner belt because their flux level is orders of magnitude higher than the background, while higher-energy electron (>1.6 MeV) measurements cannot be distinguished from the background. Detailed analysis of high-quality measurements from the Relativistic Electron and Proton Telescope on board Van Allen Probes, in a geo-transfer-like orbit, provides, for the first time, quantified upper limits on MeV electron fluxes in various energy ranges in the inner belt. These upper limits are rather different from flux levels in the AE8 and AE9 models, which were developed based on older data sources. For 1.7, 2.5, and 3.3 MeV electrons, the upper limits are about 1 order of magnitude lower than predicted model fluxes. The implication of this difference is profound in that unless there are extreme solar wind conditions, which have not happened yet since the launch of Van Allen Probes, significant enhancements of MeV electrons do not occur in the inner belt even though such enhancements are commonly seen in the outer belt. Quantified upper limit of MeV electrons in the inner beltActual MeV electron intensity likely much lower than the upper limitMore detailed understanding of relativistic electrons in the magnetosphere.

  1. High Energy (MeV) Characteristics of GRB 990123 as Measured by CGRO-COMPTEL

    Science.gov (United States)

    Young, C. A.; Connors, A.; McConnell, M.; Ryan, J. M.; Williams, O. R.; Winkler, C.; Bennett, K.; Hermsen, W.; Kuiper, L.; Collmar, W.; Schoenfelder, V.; Kippen, R. M.; CGRO-COMPTEL Team

    1999-04-01

    GRB 990123 was well-observed from MeV gamma-rays through soft X-rays by all instruments on CGRO and by BeppoSAX. Spectacularly, it was also the first to be detected in the optical during the main burst itself (Akerlof and McKay et al., GCN 205), becoming as bright as 9th magnitude in the middle of the event. It was suficiently bright above one MeV that CGRO-COMPTEL imaged the event and broadcast its position world-wide within 10 minutes of burst onset, despite its being nearly 60 degrees from the telescope's pointing direction. Here we report on its MeV properties as seen by CGRO-COMPTEL. Although much has been made of its gamma-ray/X-ray intensity (Djorgovski et al. GCN 216) in fact its high energy properties do not appear to be all that unusual. Its gamma-ray fluence (1E-4+/-.5E-4 ergs/cm(2) , 0.7-30 MeV) was clearly within the range of other bursts observed over the past 7 years by CGRO-COMPTEL (2E-4 -- 3E-6 ergs/cm(2) , 0.7-30 MeV). The burst was softer than average (consistent with OSSE findings; Matz et al GCN 231), with a photon power-law index of -3.+/-0.5 (compared to our sample average of 2.4 +/- 0.6). Again this is within the range of all bursts in the COMPTEL burst catalog. It appears to show the usual general trend of hard-to-soft spectral evolution: above 3 MeV the first peak is clearly significant, with a weak second peak roughly 10 s later; in 1-3 MeV two peaks are strongly visible with a total duration of about 28 s; in the 0.1-1 MeV one finds, in addition, a softer 44 second tail. A slightly unusual feature is the 18 s delay between the start of the softer gamma-ray emission on which BATSE triggered; and the rising edge of the main burst as seen by COMPTEL (and on which BeppoSAX triggered; Piro et al. GCN 199). In sum, our data are consistent with the hypothesis that it was this delay (plus recently improved instrumentation), rather than unprecedented properties of this gamma-ray burst, that allowed this first detection of a startlingly bright

  2. Dislocation Climb Sources Activated by 1 MeV Electron Irradiation of Copper-Nickel Alloys

    DEFF Research Database (Denmark)

    Barlow, P.; Leffers, Torben

    1977-01-01

    Climb sources emitting dislocation loops are observed in Cu-Ni alloys during irradiation with 1 MeV electrons in a high voltage electron microscope. High source densities are found in alloys containing 5, 10 and 20% Ni, but sources are also observed in alloys containing 1 and 2% Ni. The range of ...

  3. Pion Double Charge Exchange at 50 MeV on 14C

    Science.gov (United States)

    Navon, I.; Leitch, M. J.; Bryman, D. A.; Numao, T.; Schlatter, P.; Azuelos, G.; Poutissou, R.; Burnham, R. A.; Hasinoff, M.; Poutissou, J. M.; MacDonald, J. A.; Spuller, J. E.; Hargrove, C. K.; Mes, H.; Blecher, M.; Gotow, K.; Moinester, M.; Baer, H.

    1984-01-01

    The first measurement of pion double charge exchange at low energy is reported. The reaction 14C(π+,π-)14O was measured at an incident pion energy of 50 MeV. Differential cross sections of the double analog transition are given in the angular range 50°-120°. Strong nonanalog transitions were also observed.

  4. 50 MeV lithium ion beam irradiation effects in poly vinylidene ...

    Indian Academy of Sciences (India)

    Unknown

    Abstract. Irradiation effects of 50 MeV 7Li+3 ion beam induced in bulk PVDF polymer have been studied with respect to their optical, chemical, structural and electrical behaviour by using UV-visible, FT-IR spectroscopy,. XRD technique and electrical frequency response using LCR bridge. The ion fluences ranging from ...

  5. Design of the MYRRHA 17-600 MeV Superconducting Linac

    CERN Document Server

    Biarrotte, J-L; Bouly, F; Carneiro, J-P; Vandeplassche, D

    2013-01-01

    The goal of the MYRRHA project is to demonstrate the technical feasibility of transmutation in a 100MWth Accelerator Driven System (ADS) by building a new flexible irradiation complex in Mol (Belgium). The MYRRHA facility requires a 600 MeV accelerator delivering a maximum proton flux of 4 mA in continuous operation, with an additional requirement for exceptional reliability. This paper will briefly describe the beam dynamics design of the main superconducting linac section which covers the 17 to 600 MeV energy range and requires enhanced fault-tolerance capabilities.

  6. Measurement of neutron energy spectra from 15 to 150 MeV using stacked liquid scintillators

    CERN Document Server

    Buffler, A; Allie, M S; Binns, P J; Dangendorf, V; Langen, K M; Nolte, R; Schuhmacher, H

    2002-01-01

    A multiple liquid scintillator system for measuring the energy spectrum of a neutron beam in the range 15-150 MeV is described. Two or more slabs of NE213 scintillator (13x13x7 cm sup 3) are stacked behind one-another and only events in which a neutron interacts in the upstream scintillator are analysed. The system is designed to minimise the escape of forward recoil protons from the detecting media. Test measurements and Monte Carlo simulations of the detector response to quasi-monoenergetic neutron beams of energies 62.5 and 97.5 MeV are presented.

  7. 50 MeV Run of the IOTA / FAST Electron Accelerator

    Energy Technology Data Exchange (ETDEWEB)

    Edstrom Jr., D.; et al.

    2017-02-02

    The low-energy section of the photoinjector-based electron linear accelerator at the Fermilab Accelerator Science & Technology (FAST) facility was recently commissioned to an energy of 50 MeV. This linear accelerator relies primarily upon pulsed SRF acceleration and an optional bunch compressor to produce a stable beam within a large operational regime in terms of bunch charge, total average charge, bunch length, and beam energy. Various instrumentation was used to characterize fundamental properties of the electron beam including the intensity, stability, emittance, and bunch length. While much of this instrumentation was commissioned in a 20 MeV running period prior, some (including a new Martin- Puplett interferometer) was in development or pending installation at that time. All instrumentation has since been recommissioned over the wide operational range of beam energies up to 50 MeV, intensities up to 4 nC/pulse, and bunch structures from ~1 ps to more than 50 ps in length.

  8. A direct electron detector for time-resolved MeV electron microscopy

    Energy Technology Data Exchange (ETDEWEB)

    Vecchione, T.; Denes, P.; Jobe, R. K.; Johnson, I. J.; Joseph, J. M.; Li, R. K.; Perazzo, A.; Shen, X.; Wang, X. J.; Weathersby, S. P.; Yang, J.; Zhang, D.

    2017-03-01

    The introduction of direct electron detectors enabled the structural biology revolution of cryogenic electron microscopy. Direct electron detectors are now expected to have a similarly dramatic impact on time-resolved MeV electron microscopy, particularly by enabling both spatial and temporal jitter correction. Here we report on the commissioning of a direct electron detector for time-resolved MeV electron microscopy. The direct electron detector demonstrated MeV single electron sensitivity and is capable of recording megapixel images at 180 Hz. The detector has a 15-bit dynamic range, better than 30-μmμm spatial resolution and less than 20 analogue-to-digital converter count RMS pixel noise. The unique capabilities of the direct electron detector and the data analysis required to take advantage of these capabilities are presented. The technical challenges associated with generating and processing large amounts of data are also discussed.

  9. Fast neutron scattering on Gallium target at 14.8 MeV

    CERN Document Server

    Han, R; Chen, Z; Nie, Y; Liu, X; Zhang, S; Ren, P; Jia, B; Tian, G; Luo, F; Lin, W; Liu, J; Shi, F; Huang, M; Ruan, X; Ren, J; Zhou, Z; Huang, H; Bao, J; Zhang, K; Hu, B

    2014-01-01

    Benchmarking of evaluated nuclear data libraries was performed for $\\sim 14.8$ MeV neutrons on Gallium targets. The experiments were performed at China Institute of Atomic Energy(CIAE). Solid samples of natural Gallium (3.2 cm and 6.4 cm thick) were bombarded by $\\sim 14.8$ MeV neutrons and leakage neutron energy spectra were measured at 60$^{\\circ}$ and 120$^{\\circ}$. The measured spectra are rather well reproduced by MCNP-4C simulations with the CENDL-3.1, ENDF/B-VII and JENDL-4.0 evaluated nuclear data libraries, except for the inelastic contributions around $E_{n} = 10-13$ MeV. All three libraries significantly underestimate the inelastic contributions. The inelastic contributions are further studied, using the Talys simulation code and the experimental spectra are reproduced reasonably well in the whole energy range by the Talys calculation, including the inelastic contributions.

  10. Damage rates of MeV Al ions in aluminum

    Energy Technology Data Exchange (ETDEWEB)

    Noggle, T.S.; Appleton, B.R.; Williams, J.M.; Oen, O.S.; Biggerstaff, J.A.; Iwata, T.

    1976-11-01

    Damage rates of 5 MeV /sup 27/Al ions in Al have been measured as a function of the ion path length in Al. The technique developed for this study employed evaporated Al thin film (approximately 0.4 - 0.5 ..mu..m thick), electrical resistivity specimens, as a damage sensor and variation in ion path lengths were obtained by insertion of thin foils of Al immediately in front of the resistivity specimen. Irradiations and electrical resistance measurements were carried out below 10/sup 0/K to ''freeze in'' the displacement damage and to provide suitable conditions for precision electrical measurements. The resistance increase due to irradiation is a measure of the displacement damage resulting from ion-atom collisions in the specimen. The damage rates vary about an order of magnitude over the range of the ions and are in general agreement with calculated damage rates obtained from theory. 9 fig.

  11. 14 MeV neutrons physics and applications

    CERN Document Server

    Valkovic, Vladivoj

    2015-01-01

    Despite the often difficult and time-consuming effort of performing experiments with fast (14 MeV) neutrons, these neutrons can offer special insight into nucleus and other materials because of the absence of charge. 14 MeV Neutrons: Physics and Applications explores fast neutrons in basic science and applications to problems in medicine, the environment, and security.Drawing on his more than 50 years of experience working with 14 MeV neutrons, the author focuses on:Sources of 14 MeV neutrons, including laboratory size accelerators, small and sealed tube generators, well logging sealed tube ac

  12. Neutron production in neutron-induced reactions at 96 MeV on 56Fe and 208Pb

    Science.gov (United States)

    Sagrado García, I. C.; Lecolley, J. F.; Lecolley, F. R.; Blideanu, V.; Ban, G.; Fontbonne, J. M.; Itis, G.; Lecouey, J. L.; Lefort, T.; Marie, N.; Steckmeyer, J. C.; Le Brun, C.; Blomgren, J.; Johansson, C.; Klug, J.; Orhn, A.; Mermod, P.; Olsson, N.; Pomp, S.; Osterlund, M.; Tippawan, U.; Prokofiev, A. V.; Nadel-Turonski, P.; Fallot, M.; Foucher, Y.; Guertin, A.; Haddad, F.; Vatre, M.

    2011-10-01

    Double-differential cross sections for neutron production were measured in 96-MeV neutron-induced reactions at The Svedberg Laboratory in Uppsala, Sweden. Measurements for Fe and Pb targets were performed using two independent setups: DECOI-DEMON, time-of-flight telescope dedicated to the detection of emitted neutrons with energies between a few and 50MeV and CLODIA-SCANDAL device devoted to measuring emitted neutrons with energies above 40MeV. Double-differential cross sections were measured for an angular range between 15 and 98 deg and with low-energy thresholds (≈2 MeV). Angular and energy distributions and total neutron emission cross sections have been obtained from those measurements. Results have been compared with predictions given by different models included in several transport codes (MCNPX, GEANT, TALYS, PHITS, and DYWAN) and with other experimental data (the EXFOR database).

  13. Lead 207, 208 (n, xn gamma) reactions for neutron energies up to 200 MeV

    Energy Technology Data Exchange (ETDEWEB)

    Pavlik, A.; Vonach, H. [Univ. Wien (Austria). Inst. fuer Radiumforschung und Kernphysik; Chadwick, M.B.; Haight, R.C.; Nelson, R.O.; Wender, S.A.; Young, P.G. [Los Alamos National Lab., NM (United States)

    1994-07-01

    High-resolution {gamma}-ray spectra from the interaction of neutrons in the energy range from 3 to 200 MeV with {sup 207,208}Pb were measured with the white neutron source at the WNR facility at Los Alamos National Laboratory. From these data, excitation functions for prominent {gamma} transitions in {sup 200,202,204,206,207,208}Pb were derived from threshold to 200 MeV incident neutron energy. These {gamma}-production cross sections represent formation cross sections for excited states of the residual nuclei. The results are compared with the predictions of nuclear reaction calculations based on the exciton model for precompound emission, the Hauser-Feshbach theory for compound nuclear decay, and coupled channels calculations to account for direct excitation of collective levels. Good agreement was obtained over the entire energy range covered in the experiment with reasonable model parameters. The results demonstrate that multiple preequilibrium emission has to be taken into account above about 40 MeV, and that the level density model of Ignatyuk should be used instead of the Gilbert-Cameron and back-shifted Fermi-gas models if excitation energies exceed about 30 MeV.

  14. 150 MeV fixed field alternating gradient (FFAG) accelerator

    CERN Document Server

    Nakano, J

    2002-01-01

    150 MeV FFAG accelerator is prototype for practical use. Fundamental development of FFAG, research of FFAG accelerator and its application for therapy are investigated. 150 MeV ring consists of 12 sector magnets. The distribution of magnetic field of 12 sector magnets is almost same. 12 MeV proton beam is generated by cyclotron and injection to 150 MeV FFAG. The injection system consists of 2 bump magnets, kicker magnet and septum electrode. RF accelerating cavity system using high-permeability magnetic substance with high magnetic permeability accelerates proton beam to 150 MeV, then the first operation aims at 250 Hz. Return Yoke Free magnet was developed for adjustment. 150 MeV FFAG magnet is constructed and 12 MeV proton beam acceleration is conformed. The final state of 150 MeV FFAG magnet is explained by calculation results. On cancer therapy by proton beam, the three dimensions spot scan method is proposed. (S.Y.)

  15. Fast-neutron induced pre-equilibrium reactions on 55Mn and 63,65Cu at energies up to 40 MeV

    CERN Document Server

    Avrigeanu, M; Filatenkov, A A; Forrest, R A; Herman, M; Köning, A J; Plompen, A J M; Roman, F L; Avrigeanu, V

    2007-01-01

    Excitation functions were measured for the $^{55}$Mn(n,2n)$^{54}$Mn, $^{55}$Mn(n,$\\alpha$)$^{52}$V, $^{63}$Cu(n,$\\alpha$)$^{60}$Co, $^{65}$Cu(n,2n)$^{64}$Cu, and $^{65}$Cu(n,p)$^{65}$Ni reactions from 13.47 to 14.83 MeV. The experimental cross sections are compared with the results of calculations including all activation channels for the stable isotopes of Mn and Cu, for neutron incident energies up to 50 MeV. Within the energy range up to 20 MeV the model calculations are most sensitive to the parameters related to nuclei in the early stages of the reaction, while the model assumptions are better established by analysis of the data in the energy range 20-40 MeV. While the present analysis has taken advantage of both a new set of accurate measured cross sections around 14 MeV and the larger data basis fortunately available between 20 and 40 MeV for the Mn and Cu isotopes, the need of additional measurements below as well as above 40 MeV is pointed out. Keywords: 55Mn, 63,65Cu, E$\\leq$40 MeV, Neutron activati...

  16. 6 MeV storage ring dedicated to hard X-ray imaging and far-infrared ...

    Indian Academy of Sciences (India)

    ray imaging as well as far-infrared (FIR) spectroscopy. In spite of low electron energy, the 6 MeV MIRRORCLE generates hard X-rays ranging from 10 keV up to its electron energy and milliwatt order sub- millimetre range FIR rays.

  17. A MeV tunable gamma-ray source by Compton scattering

    Science.gov (United States)

    Stritt, N.; Jolie, J.; Maser, H.; Pitz, H. H.

    1996-02-01

    A tunable gamma-ray source in the MeV energy range can be obtained by Compton scattering of discrete gamma rays emitted after thermal neutron capture in an in-pile target. Here we report on the principle, on the results of Monte Carlo simulations for the photon flux and on the first realization of such a tubable gamma-ray source at the ILL high flux nuclear reactor in Grenoble (France). Two strong primary gamma rays, with energies of 6.7 and 6.4 MeV, respectively, are produced (among others) by the 48Ti(n, γ) 49Ti reaction. Compton scattering of these photons on a graphite target (scatterer) yields gamma rays of lower energy. Their energy is tunable between about 300 keV and 6 MeV by choosing the appropriate scattering angle. This tunable gamma-ray source could be a very useful tool to investigate photoexcitations in nuclei, which require gamma rays of several MeV. This new source might overcome the background problems present with bremsstrahlung sources, since it is a quasi-discrete and not a continuous source. Therefore, considerably less background is produced in the lower energetic part of the spectra.

  18. I = 0 C = +1 mesons from 1920 to 2410 MeV

    CERN Document Server

    Anisovich, A V; Batty, C J; Bugg, D V; Hodd, C; Lu, H C; Nikonov, V A; Sarantsev, A V; Sarantsev, V V; Zou, B S; 10.1016/S0370-2693(00)01018-2

    2011-01-01

    A combined fit is presented to data on pbar-p annihilation in flight to final states eta-pizero-pizero, pizero-pizero, eta-eta, eta-etaprime and piminus-piplus. The emphasis lies in improving an earlier study of eta-pizero-pizero by fitting data at nine pbar momenta simultaneously and with parameters consistent with the two-body channels. There is evidence for all of the I=0, C=+ q-qbar states expected in this mass range. New resonances are reported with masses and widths M,Gamma as follows: JPC = 4^{-+} (2328+-38, Gamma=240+-90) MeV, 1^{++} (1971+-15, 240+-45) MeV, 0^{-+} (2285+-20, 325+-30) MeV, and 0^{-+} (2010 ^{+35}_{-60}, 270+-60) MeV. Errors on the masses and widths of other resonances are also reduced substantially. All states lie close to parallel straight line trajectories of excitation number v. mass squared.

  19. Effects of repulsive three-body force in 12C + 12C scattering at 100A MeV

    Directory of Open Access Journals (Sweden)

    W.W. Qu

    2015-12-01

    Full Text Available The angular distribution of 12C + 12C scattering at an incident energy of 100A MeV has been measured. The elastic and inelastic scatterings in 12C to the excitation energies of up to ∼45 MeV were measured simultaneously for the first time with the high-resolution Grand Raiden spectrometer at the Research Center for Nuclear Physics (RCNP. The angular distributions of the elastic scattering to the ground state (01+ and inelastic scattering to the 4.44 MeV (21+ excited state were precisely obtained in the angular range of 1.0°–7.5° with a step of 0.1°. Additionally, the angular distribution was obtained for the sum of the cross sections for excitation energies above the 4.44 MeV state up to 11 MeV, which includes the 7.65 MeV (02+, 9.64 MeV (31−, and 10.30 MeV (22+ states, in addition to probably the simultaneous excitation of the 4.44 MeV state in the projectile and the target nuclei. Those combined data provide a means to study the effects of channel coupling on the elastic cross section. The observed angular distributions are compared with theoretical calculations based on three double-folding models with complex G-matrix interactions, the CEG07b, MPa, and ESC models. The importance of three-body repulsive forces included in the CEG07b and MPa models will be discussed.

  20. TARTNP: a coupled neutron--photon Monte Carlo transport code. [10-/sup 9/ to 20 MeV; in LLL FORTRAN

    Energy Technology Data Exchange (ETDEWEB)

    Plechaty, E.F.; Kimlinger, J.R.

    1976-07-04

    A Monte Carlo code was written that calculates the transport of neutrons, photons, and neutron-induced photons. The cross sections of these particles are derived from TARTNP's data base, the Evaluated Nuclear Data Library. The energy range of the neutron data in the Library is 10/sup -9/ MeV to 20 MeV; the photon energy range is 1 keV to 20 MeV. One of the chief advantages of the code is its flexibility: it allows up to 17 different kinds of output to be evaluated in the same problem.

  1. A Monitor of the Focusing Strength of Plasma Lenses Using MeV Synchrotron Radiation

    CERN Document Server

    Field, C; Ng, J S T; Field, Clive; Mazaheri, Gholam; Ng, Johnny S.T.

    2002-01-01

    The focusing strength of plasma lenses used with high energy electron or positron beams can give rise to synchrotron radiation with critical energies in the MeV range. A method is described for measuring the characteristic energy of this radiation as a way of monitoring the strength of the focus. The principle has been implemented in a plasma lens experiment with a 28.5 GeV positron beam.

  2. Cavity Formation in Aluminium Irradiated with a Pulsating Beam of 225 MeV Electrons

    DEFF Research Database (Denmark)

    Singh, Bachu Narain; Bilde-Sørensen, Jørgen; Leffers, Torben

    1984-01-01

    High-purity aluminium was irradiated with a pulsating beam of 225 MeV electrons to a maximum dose of 0.035 dpa with a helium generation rate of up to 17 appm/dpa. The irradiated samples contained cavities in the size range 5 to 70 nm. In a zone of up to 14 μm from the grain boundaries cavity size...

  3. Pion double charge exchange at 50 MeV on /sup 14/C

    Energy Technology Data Exchange (ETDEWEB)

    Navon, I.; Leitch, M.J.; Bryman, D.A.; Numao, T.; Schlatter, P.; Azuelos, G.; Poutissou, R.; Burnham, R.A.; Hasinoff, M.; Poutissou, J.M.

    1984-01-09

    The first measurement of pion double charge exchange at low energy is reported. The reaction /sup 14/C(..pi../sup +/,..pi../sup -/) /sup 14/O was measured at an incident pion energy of 50 MeV. Differential cross sections of the double analog transition are given in the angular range 50/sup 0/--120/sup 0/. Strong nonanalog transitions were also observed.

  4. Probing the cosmic x-ray and MeV gamma ray background radiation through the anisotropy

    Energy Technology Data Exchange (ETDEWEB)

    Inoue, Yoshiyuki [Stanford Univ., CA (United States); Murase, Kohta [Inst. for Advanced Study, Princeton, NJ (United States); Madejski, Grzegorz M. [Stanford Univ., CA (United States); Uchiyama, Yasunobu [Stanford Univ., CA (United States); Rikkyo Univ., Tokyo (Japan)

    2013-09-24

    While the cosmic soft X-ray background is very likely to originate from individual Seyfert galaxies, the origin of the cosmic hard X-ray and MeV gamma-ray background is not fully understood. It is expected that Seyferts including Compton thick population may explain the cosmic hard X-ray background. At MeV energy range, Seyferts having non-thermal electrons in coronae above accretion disks or MeV blazars may explain the background radiation. We propose that future measurements of the angular power spectra of anisotropy of the cosmic X-ray and MeV gamma-ray backgrounds will be key to deciphering these backgrounds and the evolution of active galactic nuclei (AGNs). As AGNs trace the cosmic large-scale structure, spatial clustering of AGNs exists. We show that e-ROSITA will clearly detect the correlation signal of unresolved Seyferts at 0.5-2 keV and 2-10 keV bands and will be able to measure the bias parameter of AGNs at both bands. Once future hard X-ray all sky satellites achieve a sensitivity better than 10–12 erg cm–2 s–1 at 10-30 keV or 30-50 keV—although this is beyond the sensitivities of current hard X-ray all sky monitors—angular power spectra will allow us to independently investigate the fraction of Compton-thick AGNs in all Seyferts. We also find that the expected angular power spectra of Seyferts and blazars in the MeV range are different by about an order of magnitude, where the Poisson term, so-called shot noise, is dominant. Current and future MeV instruments will clearly disentangle the origin of the MeV gamma-ray background through the angular power spectrum.

  5. Probing the Cosmic X-Ray and MeV Gamma-Ray Background Radiation through the Anisotropy

    Energy Technology Data Exchange (ETDEWEB)

    Inoue, Yoshiyuki [Stanford Univ., CA (United States). Kavli Inst. for Particle Astrophysics and Cosmology; SLAC National Accelerator Lab., Menlo Park, CA (United States); Murase, Kohta [Inst. for Advanced Study, Princeton, NJ (United States). School of Natural Sciences; Madejski, Grzegorz M. [Stanford Univ., CA (United States). Kavli Inst. for Particle Astrophysics and Cosmology; SLAC National Accelerator Lab., Menlo Park, CA (United States); Uchiyama, Yasunobu [Stanford Univ., CA (United States). Kavli Inst. for Particle Astrophysics and Cosmology; SLAC National Accelerator Lab., Menlo Park, CA (United States); Rikkyo Univ., Tokyo (Japan). Dept. of Physics

    2013-09-24

    While the cosmic soft X-ray background is very likely to originate from individual Seyfert galaxies, the origin of the cosmic hard X-ray and MeV gamma-ray background is not fully understood. It is expected that Seyferts including Compton thick population may explain the cosmic hard X-ray background. At MeV energy range, Seyferts having non-thermal electrons in coronae above accretion disks or MeV blazars may explain the background radiation. We propose that future measurements of the angular power spectra of anisotropy of the cosmic X-ray and MeV gamma-ray backgrounds will be key to deciphering these backgrounds and the evolution of active galactic nuclei (AGNs). As AGNs trace the cosmic large-scale structure, spatial clustering of AGNs exists. We show that e-ROSITA will clearly detect the correlation signal of unresolved Seyferts at 0.5-2 keV and 2-10 keV bands and will be able to measure the bias parameter of AGNs at both bands. Once the future hard X-ray all sky satellites achieve the sensitivity better than 10-12 erg/cm2/s-1 at 10-30 keV or 30-50 keV - although this is beyond the sensitivities of current hard X-ray all sky monitors - angular power spectra will allow us to independently investigate the fraction of Compton-thick AGNs in all Seyferts. We also find that the expected angular power spectra of Seyferts and blazars in the MeV range are different by about an order of magnitude, where the Poisson term, so-called shot noise, is dominant. Current and future MeV instruments will clearly disentangle the origin of the MeV gamma-ray background through the angular power spectrum.

  6. Photonuclear and Radiation Effects Testing with a Refurbished 20 MeV Medical Electron Linac

    CERN Document Server

    Webb, Timothy; Beezhold, Wendland; De Veaux, Linda C; Harmon, Frank; Petrisko, Jill E; Spaulding, Randy

    2005-01-01

    An S-band 20 MeV electron linear accelerator formerly used for medical applications has been recommissioned to provide a wide range of photonuclear activation studies as well as various radiation effects on biological and microelectronic systems. Four radiation effect applications involving the electron/photon beams are described. Photonuclear activation of a stable isotope of oxygen provides an active means of characterizing polymer degradation. Biological irradiations of microorganisms including bacteria were used to study total dose and dose rate effects on survivability and the adaptation of these organisms to repeated exposures. Microelectronic devices including bipolar junction transistors (BJTs) and diodes were irradiated to study photocurrent from these devices as a function of peak dose rate with comparisons to computer modeling results. In addition, the 20 MeV linac may easily be converted to a medium energy neutron source which has been used to study neutron damage effects on transistors.

  7. MeV Pulsars: Modeling Spectra and Polarization

    Science.gov (United States)

    Kust Harding, Alice; Kalapotharakos, Constantinos

    2017-08-01

    A sub-population of energetic rotation-powered pulsars show high fluxes of pulsed non-thermal hard X-ray emission. While this ‘MeV pulsar’ population includes some radio-loud pulsars like the Crab and PSR B1509-58, a significant number have no detected radio or GeV emission, a mystery since gamma-ray emission is a common characteristic of pulsars with high spin-down power. Their steeply rising hard X-ray spectral energy distributions (SEDs) suggest peaks at 0.1 - 1 MeV but they have not been detected above 200 keV. Several upcoming and planned telescopes may shed light on the MeV pulsars. The Neutron star Interior Composition ExploreR (NICER) will observe pulsars in the 0.2 - 12 keV band and may discover additional MeV pulsars. The All-Sky Medium-Energy Gamma-Ray Observatory (AMEGO), in a study phase, can detect emission above 0.2 MeV and polarization in the 0.2 - 10 MeV band. We present a model for the spectrum and polarization of MeV pulsars where the X-ray emission comes from electron-positron pairs radiating in the outer magnetosphere and current sheet. This model predicts that the peak of the SED increases with surface magnetic field strength if the pairs are produced in polar cap cascades. For small inclination angles, viewing at large angles to the rotation axis can miss both the radio pulse and the GeV pulse from particles accelerating near the current sheet. Characterizing the emission and geometry of MeV pulsars can thus provide clues to the source of pairs and acceleration in the magnetosphere.

  8. Modification of EXIFON code and analysis of O16+n reactions in En=20-50 MeV

    Energy Technology Data Exchange (ETDEWEB)

    Murata, Toru [Nippon Nuclear Fuel Development Co. Ltd., Oarai, Ibaraki (Japan)

    1997-03-01

    To evaluate the nuclear data concerning neutron induced reactions of O-16 and N-14 in the incident energy range of 20-50 MeV, the statistical multistep reaction code EXIFON was modified to include the outgoing channels of deuteron, triton and He-3. The calculated double differential cross sections (DDXs) with the modified code are compared with experimental DDXs. (author)

  9. The desing and calibration of the AHEAD deuteron polarimeter for 120 < E sub d < 250 MeV

    Energy Technology Data Exchange (ETDEWEB)

    Cameron, J.M.; Ni, B. (Indiana Univ., Bloomington, IN (USA). University Cyclotron Facility); Antonuk, L.E.; Cairns, E.B.; Fielding, H.W.; Holm, L.; Igarashi, R.; Lapointe, C.; McDonald, W.J.; Pasos, J.; Rodning, N.L.; Roy, G.; Soukup, J.; Ziegler, W. (Alberta Univ., Edmonton, AB (Canada). Dept. of Physics); Arvieux, J.; Tinslay, J.; Yonnet, J. (CEN-Saclay, 91 - Gif-sur-Yvette (France). Lab. National Saturne); Bonin, B.; Boudard, A.; Garcon, M. (CEN-Saclay, 91 - Gif-sur-Yvette (France). Service de Physique Nucleaire a Moyenne Energie); Bachelier, D. (Paris-Sud Univ., 91 - Orsay (France). Inst. de Physique Nucleaire); The, I. (Massachusetts Inst. of Tech., Middleton, MA (USA). Bates Linear Accelerator Center)

    1991-07-20

    A new type of deuteron polarimeter to work in the energy range 120 < E{sub d} < 250 MeV has been designed, constructed, and calibrated. The figure of merit ({radical}{epsilon}{Tau}{sub kq}) has been determined for various polarization components from the calibration data. (orig.).

  10. Proton-induced production of residual radionuclides in natRe up to 2590 MeV

    Science.gov (United States)

    Issa, Shams A. M.; Uosif, M. A. M.; Michel, R.; Herpers, U.; Malmborg, P.; Holmqvist, B.

    2013-03-01

    The excitation functions for residual nuclide production by proton reactions on rhenium was investigated using activated targets from irradiation experiments at the cyclotron of the Svedberg Laboratory at Uppsala up to 180 MeV and the higher energies were used at the Laboratoire Saturne at Saclay. The measured experimental results were compared with previous published and theoretical models calculations by the codes TALYS, INCL4+ABLA and Bertini/Dresner. A total of 5252 cross-section was determined covering 54 residual nuclides in the energy range from 78.2 to 2590 MeV.

  11. COPPER-64 Production Studies with Natural Zinc Targets at Deuteron Energy up to 19 Mev and Proton Energy from 141 Down to 31 Mev

    Science.gov (United States)

    Bonardi, Mauro L.; Birattari, Claudio; Groppi, Flavia; Song Mainard, Hae; Zhuikov, Boris L.; Kokhanyuk, Vladimir M.; Lapshina, Elena V.; Mebel, Michail V.; Menapace, Enzo

    2004-07-01

    High specific activity no-carrier-added 64Cu is a β-/β+ emitting radionuclide of increasing interest for PET imaging, as well as systemic and targeted radioimmunotherapy of tumors. Its peculiarity of intense Auger emitter is still under investigation. The cross-sections for production of 64Cu from Zn target of natural isotopic composition were measured in the deuteron energy range from threshold up to 19 MeV and proton energy range from 141 down to 31 MeV. The stacked-foil technique was used at both K=38 cyclotron of JRC-Ispra of CEC, Italy and 160 MeV intersection point of INR proton-LINAC in Troitsk, Russia. Several Ga, Zn, Cu, Ni, Co, V, Fe and Mn radionuclides were detected in Zn targets at the EOB. Optimized irradiation conditions are reported as a function of deuteron energy and energy loss into the Zn target, as well as target irradiation time and cooling time after radiochemistry. The activity of n.c.a. 64Cu was measured through its only γ emission of 1346 keV (i.e. 0.473 % intensity) both by instrumental and radiochemical methods, due to the non-specificity of annihilation radiation at 511 keV. To this last purpose, it was necessary to carry out a selective radiochemical separation of GaIII radionuclides by liquid/liquid extraction from the bulk of irradiated Zn targets and other spallation products, which remained in the 7 M HCl aqueous phase. Anion exchange chromatography tests had been carried out to separate the 64Cu from all others radionuclides in n.c.a. form. Theoretical calculations of cross-sections were performed with codes EMPIRE II and PENELOPE for deuteron reactions and CEF model and HMS-ALICE hybrid model for proton reactions. The theoretical results are presented and compared with the experimental values.

  12. Design and experiments of RF transverse focusing in S-Band, 1 MeV standing wave linac

    Energy Technology Data Exchange (ETDEWEB)

    Mondal, J., E-mail: jmondal@barc.gov.in; Chandan, Shiv; Parashar, S.; Bhattacharjee, D.; Tillu, A.R.; Tiwari, R.; Jayapraksh, D.; Yadav, V.; Banerjee, S.; Choudhury, N.; Ghodke, S.R.; Dixit, K.P.; Nimje, V.T.

    2015-09-21

    S-Band standing wave (SW) linacs in the range of 1–10 MeV have many potential industrial applications world wide. In order to mitigate the industrial requirement it is required to reduce the overall size and weight of the system. On this context a 2856 M Hz, 1 Me V, bi-periodic on axis coupled self transverse focused SW linac has been designed and tested. The RF phase focusing is achieved by introducing an asymmetric field distribution in the first cell of the 1 MeV linac. The pulsed electron beam of 40 keV, 650 mA and 5 µs duration is injected from a LaB{sub 6} thermionic gun. This paper presents the structure design, beam dynamics simulation, fabrication and experimental results of the 1 MeV auto-focusing SW linac.

  13. Demonstration of multilayer reflective optics at photon energies above 0.6 MeV

    DEFF Research Database (Denmark)

    Brejnholt, Nicolai F.; Soufli, Regina; Descalle, Marie-Anne

    2014-01-01

    Focusing optics operating in the soft gamma-ray photon energy range can advance a range of scientific and technological applications that benefit from the large improvements in sensitivity and resolution that true imaging provides. An enabling technology to this end is multilayer coatings. We show...... that very short period multilayer coatings deposited on super-polished substrates operate efficiently above 0.6 MeV. These experiments demonstrate that Bragg scattering theory established for multilayer applications as low as 1 eV continues to work well into the gamma-ray band. (C) 2014 Optical Society...

  14. A study on the proton beam energy(50 MeV) measurement and diagnosis (II)

    Energy Technology Data Exchange (ETDEWEB)

    Chae, Jong Suh; Lee, Dong Hoon; Kim, Yoo Suk; Park, Chan Won; Lee, Yong Min; Hong, Sung Suk; Lee, Min Yong; Lee, Ji Sub; Hah, Hang Hoh [Korea Cancer Center Hospital of Korea Atomic Energy Research Institute, Seoul (Korea, Republic of)

    1995-02-01

    The main purpose of this project is the precise ion measurement of proton beam energy extracted at RF 25.89 MHz from the MC-50 cyclotron of SF type. There are several method for particle energy measurement. We measured the 50 MeV proton energy by using the E-{Delta}E method in 1993. And also in our experiment used range, reapproval of energy of extracted proton beam at RF 25.89 MHz was performed, which attained the same energy with the result used elastic scattering within the error range. 10 figs, 2 pix, 3 tabs, 3 refs. (Author).

  15. Development of a Quasi-monoenergetic 6 MeV Gamma Facility at NASA Goddard Space Flight Center

    Science.gov (United States)

    Nowicki, Suzanne F.; Hunter, Stanley D.; Parsons, Ann M.

    2012-01-01

    The 6 MeV Gamma Facility has been developed at NASA Goddard Space Flight Center (GSFC) to allow in-house characterization and testing of a wide range of gamma-ray instruments such as pixelated CdZnTe detectors for planetary science and Compton and pair-production imaging telescopes for astrophysics. The 6 MeV Gamma Facility utilizes a circulating flow of water irradiated by 14 MeV neutrons to produce gamma rays via neutron capture on oxygen (O-16(n,p)N-16 yields O-16* yields O-16 + gamma). The facility provides a low cost, in-house source of 2.742, 6.129 and 7.117 MeV gamma rays, near the lower energy range of most accelerators and well above the 2.614 MeV line from the Th-228 decay chain, the highest energy gamma ray available from a natural radionuclide. The 7.13 s half-life of the N-16 decay allows the water to be irradiated on one side of a large granite block and pumped to the opposite side to decay. Separating the irradiation and decay regions allows for shielding material, the granite block, to be placed between them, thus reducing the low-energy gamma-ray continuum. Comparison between high purity germanium (HPGe) spectra from the facility and a manufactured source, Pu-238/C-13, shows that the low-energy continuum from the facility is reduced by a factor approx. 30 and the gamma-ray rate is approx.100 times higher at 6.129 MeV.

  16. Forecasting E > 50-MeV proton events with the proton prediction system (PPS)

    Science.gov (United States)

    Kahler, Stephen W.; White, Stephen M.; Ling, Alan G.

    2017-11-01

    Forecasting solar energetic (E > 10-MeV) particle (SEP) events is an important element of space weather. While several models have been developed for use in forecasting such events, satellite operations are particularly vulnerable to higher-energy (≥50-MeV) SEP events. Here we validate one model, the proton prediction system (PPS), which extends to that energy range. We first develop a data base of E ≥ 50-MeV proton events >1.0 proton flux units (pfu) events observed on the GOES satellite over the period 1986-2016. We modify the PPS to forecast proton events at the reduced level of 1 pfu and run PPS for four different solar input parameters: (1) all ≥M5 solar X-ray flares; (2) all ≥200 sfu 8800-MHz bursts with associated ≥M5 flares; (3) all ≥500 sfu 8800-MHz bursts; and (4) all ≥5000 sfu 8800-MHz bursts. The validation contingency tables and skill scores are calculated for all groups and used as a guide to use of the PPS. We plot the false alarms and missed events as functions of solar source longitude, and argue that the longitude-dependence employed by PPS does not match modern observations. Use of the radio fluxes as the PPS driver tends to result in too many false alarms at the 500 sfu threshold, and misses more events than the soft X-ray predictor at the 5000 sfu threshold.

  17. MeV ion beams generated by intense pulsed laser monitored by Silicon Carbide detectors

    Science.gov (United States)

    Calcagno, L.; Musumeci, P.; Cutroneo, M.; Torrisi, L.; La Via, F.; Ullschmied, J.

    2014-04-01

    The high energy ions produced with intense pulsed laser were analyzed with Silicon Carbide detectors. In order to realize high performances and radiation resistant detectors, high quality and thick epitaxial layer were grown on a substrate and a Schottky diodes were then realized. These detectors were employed to probe the plasma generated with a 300 ps laser at intensity of 1016 W/cm2 operating at Prague Asterix Laser System Laboratory. They show a fast response and a high sensitivity to high energy ions. Metallic and polymeric thin films were irradiated and the produced plasmas were monitored in forward and backward directions. The analysis of the time-of-flight spectra evidences the emission of protons and ions at different energies. The spectra were deconvolved with a shifted Maxwell Boltzmann distribution. In our experimental conditions we detected protons in the energy range 1.2 - 3.0 MeV and heavy ions between 1.0 MeV up to 40 MeV depending on the target and the laser energy. The results were compared with the ones obtained by Thompson Parabola Spectrometer.

  18. 400-MeV upgrade for the Fermilab linac

    Energy Technology Data Exchange (ETDEWEB)

    Young, D.E.; Noble, R.J.

    1989-09-01

    Fermilab plans to upgrade the Tevatron to expand the physics research program in both the fixed target and the collider operating modes. The first phase of this program is to increase the energy of the H{sup -} linac from 200 to 400 MeV in order to reduce the incoherent space change tuneshift at injection into the Booster which can limit either the brightness or the total intensity of the beam. The linac upgrade will be achieved by replacing the last four 201 MeV, with seven 805 MHz side-coupled cavity modules operating at an average axial field of about 8 MV/m. This will allow acceleration to 400 MeV in the existing Linac enclosure. 4 refs., 3 figs., 1 tab.

  19. 3 MeV Test Stand commissioning report

    CERN Document Server

    Bellodi, Guilia; Andreassen, O; Comblin, J-F; Dimov, V; Lallement, J-B; Martin, C; Midttun, O; Ovalle, E; Raich, U; Roncarolo, F; Rossi, C; Scrivens, R; Vollaire, J; Yarmohammadi Satri, M; Zocca, Z

    2013-01-01

    Linac4 is a normal-conducting 160 MeV H- linear accelerator, presently under construction, that will replace the present 50 MeV Linac2 as injector of the CERN proton accelerator complex with the goal of increasing the LHC luminosity. The Linac4 front-end, composed of a 45 keV ion source, a Low Energy Beam Transport (LEBT), a 352.2 MHz Radio Frequency Quadrupole (RFQ) and a Medium Energy Beam Transport (MEBT) housing a beam chopper, was commissioned at the 3 MeV test stand area during the first half of 2013. This report gives details of the installation and operational systems used, describes the commissioning phases and measurements performed and summarizes the results that were finally achieved and the lessons learnt in the process.

  20. Bent crystal channeling of 255 MeV electrons

    Science.gov (United States)

    Takabayashi, Y.; Pivovarov, Yu. L.; Tukhfatullin, T. A.

    2018-01-01

    Charged particles channeled in a bent crystal plane are known to be deflected along the bent plane. Such studies have mainly been performed for high-energy positively-charged particles such as protons, and recently for electrons with energies from 855 MeV to 20.35 GeV. In this work, we present experimental results on the bent crystal channeling of electrons for a lower energy region (255 MeV), where the multiple scattering effect in a crystal is expected to be more dominant. Angular distributions of electrons transmitted through a bent Si crystal have been measured, which are in good agreement with the simulation results.

  1. Large momentum transfer neutron pickup with the (. pi. /sup +/,p) and (p,d) reactions. [90 and 180 MeV, 800 MeV

    Energy Technology Data Exchange (ETDEWEB)

    Smith, G.R.

    1980-01-01

    The (p,d) reaction was studied for the first time at 800 MeV on seven targets ranging from /sup 7/Li to /sup 40/Ca. The experimental resolution (approx. 400 keV) attained was sufficient to observe many discrete levels in each of the residual nuclei. A modified version of the one-nucleon model successfully describes the magnitude and angular dependence of almost all of the transitions observed. A specific counter example to the two-nucleon model of the reaction mechanism is suggested. The calculations are also sensitive to the neutron single-particle wave function, in accordance with the expectation that the high-momentum components of this wave function are probed at higher bombarding energies. States that have never been seen before were strongly populated in the high excitation region (up to 25 MeV) of some of the residual nuclei. The relative intensities of the other levels observed suggest that coupled-channels mechanisms play an important role for some of these states. Explicit calculations were performed to confirm this for several examples. The first high-resolution measurements of the (..pi../sup +/,p) reaction were also performed on /sup 6/Li, /sup 7/Li, /sup 12/C, and /sup 13/C at pion bombarding energies on and off the pion-nucleon resonance. Calculations employing a one-nucleon model of the reaction mechanism similar to the model successfully used for the (p,d) reaction are unable to account for transitions in the (..pi../sup +/,p) reaction. It is, however, unclear whether this failure is due to a fundamental inadequacy of the model or improper treatment of details in the calculations. A striking similarity was observed in the spectra of the (..pi../sup +/,p) and 800-MeV (p,d) reactions on the same target; this result implies a similar mechanism for the two reactions. 120 references, 97 figures, 15 tables.

  2. Experimental analysis of neutron and background gamma-ray energy spectra of 80-400 MeV 7Li(p,n reactions under the quasi-monoenergetic neutron field at RCNP, Osaka University

    Directory of Open Access Journals (Sweden)

    Iwamoto Yosuke

    2017-01-01

    Full Text Available To develop the 100-400 MeV quasi-monoenergetic neutron field, we measured neutron and unexpected gamma-ray energy spectra of the 7Li(p,n reaction with 80-389 MeV protons in the 100-m time-of-flight (TOF tunnel at the Research Center for Nuclear Physics (RCNP cyclotron facility. Neutron energy spectra with energies above 3 MeV were measured by the TOF method, which had been reported in our previous papers, and photon energy spectra with energies above 0.1 MeV were measured by the automatic unfolding function of the radiation dose monitor DARWIN. For neutron spectra, the contribution of peak intensity to the total intensity integrated with energies above 3 MeV varied between 0.38 and 0.48 in the proton energy range of 80–389 MeV. For gamma-ray spectra, highenergetic gamma-rays at around 70 MeV originated from the decay of π0 were observed with proton energies higher than 200 MeV. For the 246-MeV proton incident reaction, the contribution of gamma-ray dose to neutron dose is negligible because the ratio of gamma-ray dose to neutron dose is 0.014.

  3. History of the ZGS 500 MeV booster.

    Energy Technology Data Exchange (ETDEWEB)

    Simpson, J.; Martin; R.; Kustom, R.

    2006-05-09

    The history of the design and construction of the Argonne 500 MeV booster proton synchrotron from 1969 to 1982 is described. This accelerator has since been in steady use for the past 25 years to power the Argonne Intense Pulsed Neutron Source (IPNS).

  4. Linac4 crosses the 100 MeV threshold

    CERN Multimedia

    Corinne Pralavorio

    2016-01-01

    The new linear accelerator, which from 2020 will be the first link in the accelerator chain, has entered a new stage of its commissioning.   Members of the team in charge of the commissioning of Linac4 in the accelerator’s control room. A few hours earlier, Linac4 accelerated a beam to 107 MeV for the first time. We couldn’t have imagined a more appropriate date: on 1 July (1.07), Linac4 reached an energy of 107 MeV. Having crossed the 100 MeV barrier, the linear accelerator is now on the home straight of its commissioning. “This stage was very quick – it took less than two weeks,” says Alessandra Lombardi, deputy project leader of Linac4, in charge of the commissioning. In 2020, Linac4 will replace the existing Linac2 as the first link in the accelerator chain. It will accelerate beams of H- ions (protons surrounded by two electrons) to 160 MeV, compared to 50 MeV with Linac2. The new machine is particularly sophisticated as it comprises...

  5. Identification and imaging of modern paints using Secondary Ion Mass Spectrometry with MeV ions

    DEFF Research Database (Denmark)

    Bogdanović Radović, Iva; Siketić, Zdravko; Jembrih-Simbürger, Dubravka

    2017-01-01

    Secondary Ion Mass Spectrometry using MeV ion excitation was applied to analyse modern paint materials containing synthetic organic pigments and binders. It was demonstrated that synthetic organic pigments and binder components with molecular masses in the m/z range from 1 to 1200 could...... be identified in different paint samples with a high efficiency and in a single measurement. Different ways of mounting of mostly insulating paint samples were tested prior to the analysis in order to achieve the highest possible yield of pigment main molecular ions. As Time-of-Flight mass spectrometer for Me...

  6. The Spectrum of Isotropic Diffuse Gamma-Ray Emission Between 100 Mev and 820 Gev

    Science.gov (United States)

    Ackermann, M.; Ajello, M.; Albert, A.; Atwood, W. B.; Baldini, L.; Ballet, J.; Barbiellini, G.; Bastieri, D.; Brandt, T. J.; Hays, E.; hide

    2014-01-01

    The gamma-ray sky can be decomposed into individually detected sources, diffuse emission attributed to the interactions of Galactic cosmic rays with gas and radiation fields, and a residual all-sky emission component commonly called the isotropic diffuse gamma-ray background (IGRB). The IGRB comprises all extragalactic emissions too faint or too diffuse to be resolved in a given survey, as well as any residual Galactic foregrounds that are approximately isotropic. The first IGRB measurement with the Large Area Telescope (LAT) on board the Fermi Gamma-ray Space Telescope (Fermi) used 10 months of sky-survey data and considered an energy range between 200 MeV and 100 GeV. Improvements in event selection and characterization of cosmic-ray backgrounds, better understanding of the diffuse Galactic emission, and a longer data accumulation of 50 months, allow for a refinement and extension of the IGRB measurement with the LAT, now covering the energy range from 100 MeV to 820 GeV. The IGRB spectrum shows a significant high-energy cutoff feature, and can be well described over nearly four decades in energy by a power law with exponential cutoff having a spectral index of 2.32 plus or minus 0.02 and a break energy of (279 plus or minus 52) GeV using our baseline diffuse Galactic emission model. The total intensity attributed to the IGRB is (7.2 plus or minus 0.6) x 10(exp -6) cm(exp -2) s(exp -1) sr(exp -1) above 100 MeV, with an additional +15%/-30% systematic uncertainty due to the Galactic diffuse foregrounds.

  7. The prediction of Neutron Elastic Scattering from Tritium for E(n) = 6-14 MeV

    Energy Technology Data Exchange (ETDEWEB)

    Anderson, J D; Dietrich, F S; Luu, T; McNabb, D P; Navratil, P; Quaglioni, S

    2010-06-14

    In a recent report Navratil et al. evaluated the angle-integrated cross section and the angular distribution for 14-MeV n+T elastic scattering by inferring these cross sections from accurately measured p+3He angular distributions. This evaluation used a combination of two theoretical treatments, based on the no-core shell model and resonating-group method (NCSM/RGM) and on the R-matrix formalism, to connect the two charge-symmetric reactions n+T and p+{sup 3}He. In this report we extend this treatment to cover the neutron incident energy range 6-14 MeV. To do this, we evaluate angle-dependent correction factors for the NCSM/RGM calculations so that they agree with the p+{sup 3}He data near 6 MeV, and using the results found earlier near 14 MeV we interpolate these correction factors to obtain correction factors throughout the 6-14 MeV energy range. The agreement between the corrected NCSM/RGM and R-Matrix values for the integral elastic cross sections is excellent ({+-}1%), and these are in very good agreement with total cross section experiments. This result can be attributed to the nearly constant correction factors at forward angles, and to the evidently satisfactory physics content of the two calculations. The difference in angular shape, obtained by comparing values of the scattering probability distribution P({mu}) vs. {mu}(the cosine of the c.m. scattering angle), is about {+-}4% and appears to be related to differences in the two theoretical calculations. Averaging the calculations yields P({mu}) values with errors of {+-}2 1/2 % or less. These averaged values, along with the corresponding quantities for the differential cross sections, will form the basis of a new evaluation of n+T elastic scattering. Computer files of the results discussed in this report will be supplied upon request.

  8. Measurement and analysis of gamma-rays emitted from spent nuclear fuel above 3 MeV.

    Science.gov (United States)

    Rodriguez, Douglas C; Anderson, Elaina; Anderson, Kevin K; Campbell, Luke W; Fast, James E; Jarman, Kenneth; Kulisek, Jonathan; Orton, Christopher R; Runkle, Robert C; Stave, Sean

    2013-12-01

    The gamma-ray spectrum of spent nuclear fuel in the 3-6 MeV energy range is important for active interrogation since gamma rays emitted from nuclear decay are not expected to interfere with measurements in this energy region. There is, unfortunately, a dearth of empirical measurements from spent nuclear fuel in this region. This work is an initial attempt to partially fill this gap by presenting an analysis of gamma-ray spectra collected from a set of spent nuclear fuel sources using a high-purity germanium detector array. This multi-crystal array possesses a large collection volume, providing high energy resolution up to 16 MeV. The results of these measurements establish the continuum count-rate in the energy region between 3 and 6 MeV. Also assessed is the potential for peaks from passive emissions to interfere with peak measurements resulting from active interrogation delayed emissions. As one of the first documented empirical measurements of passive emissions from spent fuel for energies above 3 MeV, this work provides a foundation for active interrogation model validation and detector development. © 2013 Elsevier Ltd. All rights reserved.

  9. Prospects for indirect MeV dark matter detection with gamma rays in light of cosmic microwave background constraints

    Science.gov (United States)

    González-Morales, Alma X.; Profumo, Stefano; Reynoso-Cordova, Javier

    2017-09-01

    The self-annihilation of dark matter particles with mass in the MeV range can produce gamma rays via prompt or secondary radiation. The annihilation rate for such light dark matter particles is however tightly constrained by cosmic microwave background (CMB) data. Here we explore the possibility of discovering MeV dark matter annihilation with future MeV gamma-ray telescopes taking into account the latest and future CMB constraints. We study the optimal energy window as a function of the dominant annihilation final state. We consider both the (conservative) case of the dwarf spheroidal galaxy Draco and the (more optimistic) case of the Galactic center. We find that for certain channels, including those with one or two monochromatic photon(s) and one or two neutral pion(s), a detectable gamma-ray signal is possible for both targets under consideration and compatible with CMB constraints. For other annihilation channels, however, including all leptonic annihilation channels and two charged pions, CMB data rule out any significant signal of dark matter annihilation at future MeV gamma-ray telescopes from dwarf galaxies, but possibly not for the Galactic center.

  10. Excitation functions of the proton induced nuclear reactions on natZn up to 40 MeV

    Science.gov (United States)

    Uddin, M. S.; Khandaker, M. U.; Kim, K. S.; Lee, Y. S.; Kim, G. N.

    2007-05-01

    We measured the excitation functions of the natZn(p,xn) 66,67Ga, natZn(p,pxn) 62,65,69mZn, and natZn(p,αxn) 61Cu nuclear processes up to 40 MeV by using a stacked-foil activation technique at the MC50 cyclotron of the Korea Institute of Radiological and Medical Sciences. The results were compared with the earlier reported experimental data and theoretical calculations based on the ALICE-IPPE code. We have given new data points for the formation of the above radionuclides. The present values are in good agreement with some well-measured literature values. Integral yields were also deduced from the measured cross-sections. The reported direct measured thick target yields for the formation of the 66Ga and 67Ga radionuclides at 22 MeV support our deduced yields. The optimum formation of the 66Ga and 61Cu radionuclides with minimum impurities can be obtained at 8-15 MeV and 10-20 MeV energy range, respectively. The yields and decay characteristics of the nuclide 65Zn are suitable for thin layer activation analysis.

  11. Double-shot MeV electron diffraction and microscopy

    Directory of Open Access Journals (Sweden)

    P. Musumeci

    2017-07-01

    Full Text Available In this paper, we study by numerical simulations a time-resolved MeV electron scattering mode where two consecutive electron pulses are used to capture the evolution of a material sample on 10 ps time scales. The two electron pulses are generated by illuminating a photocathode in a radiofrequency photogun by two short laser pulses with adjustable delay. A streak camera/deflecting cavity is used after the sample to project the two electron bunches on two well separated regions of the detector screen. By using sufficiently short pulses, the 2D spatial information from each snapshot can be preserved. This “double-shot” technique enables the efficient capture of irreversible dynamics in both diffraction and imaging modes. In this work, we demonstrate both modes in start-to-end simulations of the UCLA Pegasus MeV microscope column.

  12. European Collaboration for High-Resolution Measurements of Neutron Cross Sections between 1 MeV and 250 MeV

    CERN Multimedia

    Leal, L C; Kitis, G; Guber, K H; Yuasa nakagawa, K; Koehler, P E; Quaranta, A

    2002-01-01

    The experimental determination of neutron cross section data has always been of primary importance in Nuclear Physics. Many of the salient features of nuclear levels and densities can be determined from the resonant structure of such cross sections and of their decay scheme. An associated importance of precise neutron induced reaction cross sections has resulted from the worldwide interest in Accelerator Driven Systems (ADS) that has emerged at CERN and elsewhere. Many applications, such as accelerator-based transmutation of nuclear waste, energy amplification medical research, astrophysical applications and also fusion research require nuclear data that quantitatively and qualitatively go beyond the presently available traditional evaluation.\\\\ \\\\We consider a spallation driven TOF facility at the CERN-PS with an unprecedented neutron flux (1000 times the existing ones) in the broad energy range between 1 eV and 250 MeV and with very high energy resolution. The present concept for an intense neutron source m...

  13. Thermal Dark Matter Below a MeV

    OpenAIRE

    Berlin, Asher; Blinov, Nikita

    2018-01-01

    We consider a class of models in which thermal dark matter is lighter than a MeV. If dark matter thermalizes with the standard model below the temperature of neutrino-photon decoupling, equilibration and freeze-out cool and heat the standard model bath comparably, alleviating constraints from measurements of the effective number of neutrino species. We demonstrate this mechanism in a model consisting of fermionic dark matter coupled to a light scalar mediator. Thermal dark matter can be as li...

  14. Construction of a pulsed MeV positron beam line

    Energy Technology Data Exchange (ETDEWEB)

    Masuno, Shin-ichi; Okada, Sohei; Kawasuso, Atsuo [Japan Atomic Energy Research Inst., Takasaki, Gunma (Japan). Takasaki Radiation Chemistry Research Establishment

    1997-03-01

    To develop a fast (1 MeV) and short pulsed (100 ps) positron beam which enables defect behavior analysis of bulk states of materials even at high temperatures where a usual positron source would melt, we have been performing design study and construction of the beam line in a three-year program since 1994. This report describes the components, design study results and experimental results of the completed parts until now. (author)

  15. Evolution of the 400 MeV linac design

    Energy Technology Data Exchange (ETDEWEB)

    MacLachlan, J.A.

    1987-11-09

    The basic premises of the conceptual design for the linac upgrade are pursued to establish lengths, gradients, power dissipation, etc., for the 400 MeV linac and matching section. The discussion is limited to accelerating and focusing components. Wherever values depend on the choice of the accelerating structure, the disk-and-washer structure is emphasized; the results are generally relevant to the side coupled cavity choice also.

  16. Midplane measurements of MeV ion confinement in TFTR

    Science.gov (United States)

    Boivin, R.; Kilpatrick, S.; Manos, D.; Zweben, S.

    1990-10-01

    A new detector has been designed and installed on TFTR for studying the confinement of MeV ions, especially for measuring the losses due to the toroidal field ripple. It is located just below the outer midplane where the peak in ripple-induced losses is expected. The detector consists of a scintillator [ZnS(Ag)] and collimating apertures mounted on a radially movable probe. New design features of this detector are presented along with some of the first results.

  17. Ionization potentials of alkali atoms: towards meV accuracy

    Energy Technology Data Exchange (ETDEWEB)

    Eliav, Ephraim [School of Chemistry, Tel Aviv University, 69978 Tel Aviv (Israel); Vilkas, Marius J [Department of Chemistry, University of Puerto Rico, P.O. Box 23346, San Juan, Puerto Rico 00931-3346 (Puerto Rico); Ishikawa, Yasuyuki [Department of Chemistry, University of Puerto Rico, P.O. Box 23346, San Juan, Puerto Rico 00931-3346 (Puerto Rico); Kaldor, Uzi [School of Chemistry, Tel Aviv University, 69978 Tel Aviv (Israel)]. E-mail: kaldor@jade.tau.ac.il

    2005-04-25

    Ionization potentials of orbitals in the three shells above the cation closed-shell structure (17 IPs per atom) are calculated for the alkali atoms Rb, Cs, Fr and element 119. The Dirac-Coulomb-Breit Hamiltonian is used as framework, and correlation is included by the multireference Fock-space coupled cluster method with single and double excitations. The basis includes 36s32p24d22f10g7h6i Gaussian-type orbitals. Comparison with the 45 experimentally known IPs shows excellent agreement, with an average absolute error of 11 cm{sup -1} (1.4 meV) or 0.10% and maximum error of 81 cm{sup -1} (10 meV) or 0.25%. The largest errors occur in the ground state IPs. Correcting for the Lamb shifts improves the s orbital binding energies, reducing the maximum error to 60 cm{sup -1} (7.4 meV) or 0.19%. The remaining error is attributed to the truncation of the coupled cluster expansion and, to lesser extent, to small deficiencies in the basis.

  18. Environmental Values (2-MEV and Appreciation of Nature

    Directory of Open Access Journals (Sweden)

    Franz X. Bogner

    2018-01-01

    Full Text Available When monitoring the long history of empirical instruments for environmental attitude measurement, the Two Major Environmental Value model (2-MEV with its two higher order factors: Preservation (PRE and Utilization (UTL has repeatedly and independently been confirmed. PRE assesses preferences towards conservation of nature and the environment, whilst UTL measures preferences towards utilization/exploitation of nature. The latter, however, does not yet include the positive aspects of benefitting from the (enjoyable use of nature. Consequently, besides the established 2-MEV-battery, additional items from an “Appreciation of Nature” (APR scale were applied to an Irish sample of 289 secondary school students (age: M = 14.3 years. Responses to the altogether 30-item battery were applied on an oblique rotation by using the Promax procedure: UTL and PRE appeared as orthogonally related factors, APR correlated to PRE with 0.283. Based on loading scores, the item number for each subscale was further reduced to make the analysis more manageable in educational outreach sites; on those sites, where completing questionnaires may well be quite unpopular, they are very much needed for planning and fine-tuning educational programs. Therefore, extending the 2-MEV scale with an added scale for Appreciation may help: (i to judge participants’ feedback for adjusting/balancing program contents better; and (ii to promote appreciation as a successful strategy for shifting individuals away from their individual exploitative preferences.

  19. Application of calorimeters for 5 MeV EB and bremsstrahlung dosimetry

    DEFF Research Database (Denmark)

    Sato, T.; Takahashi, T.; Saito, T.

    1993-01-01

    Graphite and water calorimeters, which were developed for use a 10 MeV electron beams (EB) at Riso National Laboratory, were used for process validation and routine dosimeter calibration at a 5 MeV EB. Water calorimeters were used for reference measurements for 5 MeV EB, the response was found...... at 5 MeV EB. Graphite calorimeters gave reproducible readings within 3.3 % relative errors (95 % confidence level) for X-ray measurement....

  20. Cross sections and analyzing powers of sup 15 N(p,n) sup 15 O at 200 MeV and 494 MeV

    Energy Technology Data Exchange (ETDEWEB)

    Ciskowski, D.E. (Los Alamos National Lab., NM (USA))

    1989-11-01

    Differential cross sections and analyzing powers have been measured for the {sup 15}N(p,n){sup 15} O(g.s.) reaction at bombarding energies of 200 MeV and 494 MeV. The 494 MeV data were obtained at the LAMPF Neutron Time-Of-Flight Facility on an 82 m flight path with a resolution of about 2.7 MeV. The 200 MeV data were obtained at IUCF on a 76m flight path with a resolution of about 1.1 MeV. At both energies, the measured analyzing power is small, the magnitude is less than .2 for momentum transfers of less than 1 fm{sup {minus}1}. In contrast, both Relativistic and standard DWIA calculations predict a maximum of A={minus}.7 near q=0.7 fm{sup {minus}1}. 53 refs., 44 figs.

  1. First H- beam accelerated at Linac4: 3MeV done, 157 MeV to go!

    CERN Multimedia

    Linac4 Project Team

    2013-01-01

    On 14 November, the first H- (one proton surrounded by two electrons) beam was accelerated to the energy of 3 MeV in the Linac4 - the new linear accelerator that will replace Linac2 as low-energy injector in the LHC accelerator chain.      A view of the Linac4 taken during the recent tests (top image) and the current measured by the instruments at the end of the acceleration line on 14 November (bottom image). Images: Linac4 collaboration. Using the recently installed Radio Frequency Quadrupole (RFQ) accelerator, 13 mA of current were accelerated to the energy of 3 MeV. After the successful commissioning of the Linac4 RFQ at the 3 MeV test stand completed during the first months of 2013, the whole equipment (composed of the RFQ itself, the following Medium Energy Beam Transport line and its diagnostic line) were moved to the Linac4 tunnel during summer and installed in their final position. In the meantime, a new ion source was assembled, installed and successfu...

  2. Measurement and calculation of neutron leakage spectra from slab samples of beryllium, gallium and tungsten irradiated with 14.8 MeV neutrons

    Science.gov (United States)

    Nie, Y. B.; Ruan, X. C.; Ren, J.; Zhang, S.; Han, R.; Bao, J.; Huang, H. X.; Ding, Y. Y.; Wu, H. C.; Liu, P.; Zhou, Z. Y.

    2017-09-01

    In order to make benchmark validation of the nuclear data for gallium (Ga), tungsten (W) and beryllium (Be) in existing modern evaluated nuclear data files, neutron leakage spectra in the range from 0.8 to 15 MeV from slab samples were measured by time-of-flight technique with a BC501 scintillation detector. The measurements were performed at China Institute of Atomic Energy (CIAE) using a D-T neutron source. The thicknesses of the slabs were 0.5 to 2.5 mean free path for 14.8 MeV neutrons, and the measured angles were chosen to be 60∘ and 120∘. The measured spectra were compared with those calculated by the continuous energy Monte-Carlo transport code MCNP, using the data from the CENDL-3.1, ENDF/B-VII.1 and JENDL-4.0 nuclear data files, the comparison between the experimental and calculated results show that: The results from all three libraries significantly underestimate the cross section in energy range of 10-13 MeV for Ga; For W, the calculated spectra using data from CENDL-3.1 and JENDL-4.0 libraries show larger discrepancies with the measured ones, especially around 8.5-13.5 MeV; and for Be, all the libraries led to underestimation below 3 MeV at 120∘.

  3. Occurrence of brain tumors in rhesus monkeys exposed to 55-MeV protons

    Science.gov (United States)

    Wood, D. H.; Yochmowitz, M. G.; Hardy, K. A.; Salmon, Y. L.

    Twenty-year observation of monkeys exposed to single doses of high energy protons simulating solar particles revealed that the most prevalent fatal cancers were brain tumors in the group of animals exposed to 55-MeV protons. Of 72 animals (50 males and 22 females) receiving 0.25 to 8.0 Gy total body surface dose, nine developed fatal tumors classified as grade IV astrocytoma or glioblastoma multiforme. The latent period for tumor development ranged from 14 months to 20 years, with a median of 5 years. Doses associated with the tumors were 4.0 to 8.0 Gy. Eight males and one female were affected. Depth-dose determinations suggest that the high incidence of cerebral neoplasia is associated with the Bragg Peak energy distribution of the 55-MeV protons. Comparison of the tumor incidence with that in humans with brain exposures incidental to radiotherapy indicates a high biological effectiveness compared with gamma radiation. Studies are in progress to attempt to replicate the results in rodents and establish a dose-response curve for proton-induced brain tumors.

  4. Evaluation of the n + 3H Cross Section at En=14 MeV

    Energy Technology Data Exchange (ETDEWEB)

    Navratil, P; Quaglioni, S; Anderson, J D; Dietrich, F S; McNabb, D P; Hale, G M

    2010-02-10

    The n + {sup 3}H cross section is important for NIF diagnostics. As the d-{sup 3}H fusion at NIF generates neutrons with an energy of 14 MeV, the precise knowledge of the n + {sup 3}H cross section and in particular the elastic cross section at that energy is crucial. Experimental data at E{sub n} = 14 MeV are not accurate with large disagreements among different sets of measurements. On the other hand, the mirror reaction p-{sup 3}He is well studied and accurate data are available in a wide range of proton energies. We use several theoretical approaches to evaluate the n-{sup 3}H cross section by fine-tuning the theory to reproduce the p-{sup 3}He elastic differential cross sections. The good agreement between the R-matrix analysis and scaled ab initio calculations gives us confidence that our evaluated n + {sup 3}H cross section is accurate with an uncertainty on the order of 5%.

  5. Application of nuclear models. [1 to 40 MeV, review

    Energy Technology Data Exchange (ETDEWEB)

    Young, P.G.; Arthur, E.D.; Madland, D.G.

    1979-01-01

    The development of extensive experimental nuclear data base over the past three decades has been accompanied by parallel advancement of nuclear theory and models used to describe and interpret the measurements. This theoretical capability is important because of many nuclear data requirements that are still difficult, impractical, or even impossible to meet with present experimental techniques. Examples of such data needs are neutron cross sections for unstable fission products, which are required for neutron absorption corrections in reactor calculations; cross sections for transactinide nuclei that control production of long-lived nuclear wastes; and the extensive dosimetry, activation, and neutronic data requirements to 40 MeV that must accompany development of the Fusion Materials Irradation Test (FMIT) facility. In recent years systematic improvements have been made in the nuclear models and codes used in data evaluation and, most importantly, in the methods used to derive physically based parameters for model calculations. The newly issued ENDF/B-V evaluated data library relies in many cases on nuclear reaction theory based on compound-nucleus Hauser-Feshbach, preequilibrium and direct reaction mechanisms as well as spherical and deformed optical-model theories. The development and applications of nuclear models for data evaluation are discussed with emphasis on the 1 to 40 MeV neutron energy range.

  6. Target irradiation facility and targetry development at 160 MeV proton beam of Moscow linac

    CERN Document Server

    Zhuikov, B L; Konyakhin, N A; Vincent, J

    1999-01-01

    A facility has been built and successfully operated with the 160 MeV proton beam of Moscow Meson factory LINAC, Institute for Nuclear Research (INR) of Russian Academy of Science, Troitsk. The facility was created for various isotope production goals as well as for fundamental nuclear investigations at high intensity beam (100 mu A and more). An important part of the facility targetry system is a high-intensity beam monitoring collimator device. Measurements of the temperature distribution between collimator sectors, cooling water flow and temperature, and the beam current, provide an opportunity to compute beam losses and beam position. The target holder design allows easy insertion by manipulator and simultaneous bombardment of several different targets of various types and forms, and variation of proton energy on each target over a wide range below 160 MeV. The main target utilized for commercial sup 8 sup 2 Sr isotope production is metallic rubidium in a stainless-steel container. A regular wet chemistry ...

  7. Identification and imaging of modern paints using Secondary Ion Mass Spectrometry with MeV ions

    Science.gov (United States)

    Bogdanović Radović, Iva; Siketić, Zdravko; Jembrih-Simbürger, Dubravka; Marković, Nikola; Anghelone, Marta; Stoytschew, Valentin; Jakšić, Milko

    2017-09-01

    Secondary Ion Mass Spectrometry using MeV ion excitation was applied to analyse modern paint materials containing synthetic organic pigments and binders. It was demonstrated that synthetic organic pigments and binder components with molecular masses in the m/z range from 1 to 1200 could be identified in different paint samples with a high efficiency and in a single measurement. Different ways of mounting of mostly insulating paint samples were tested prior to the analysis in order to achieve the highest possible yield of pigment main molecular ions. As Time-of-Flight mass spectrometer for MeV Secondary Ion Mass Spectrometry is attached to the heavy ion microprobe, molecular imaging on cross-sections of small paint fragments was performed using focused ions. Due to the fact that molecules are extracted from the uppermost layer of the sample and to avoid surface contamination, the paint samples were not embedded in the resin as is usually done when imaging of paint samples using different techniques in the field of cultural heritage.

  8. MeV proton flux predictions near Saturn's D ring.

    Science.gov (United States)

    Kollmann, P; Roussos, E; Kotova, A; Cooper, J F; Mitchell, D G; Krupp, N; Paranicas, C

    2015-10-01

    Radiation belts of MeV protons have been observed just outward of Saturn's main rings. During the final stages of the mission, the Cassini spacecraft will pass through the gap between the main rings and the planet. Based on how the known radiation belts of Saturn are formed, it is expected that MeV protons will be present in this gap and also bounce through the tenuous D ring right outside the gap. At least one model has suggested that the intensity of MeV protons near the planet could be much larger than in the known belts. We model this inner radiation belt using a technique developed earlier to understand Saturn's known radiation belts. We find that the inner belt is very different from the outer belts in the sense that its intensity is limited by the densities of the D ring and Saturn's upper atmosphere, not by radial diffusion and satellite absorption. The atmospheric density is relatively well constrained by EUV occultations. Based on that we predict an intensity in the gap region that is well below that of the known belts. It is more difficult to do the same for the region magnetically connected to the D ring since its density is poorly constrained. We find that the intensity in this region can be comparable to the known belts. Such intensities pose no hazard to the mission since Cassini would only experience these fluxes on timescales of minutes but might affect scientific measurements by decreasing the signal-to-contamination ratio of instruments.

  9. Femtosecond gas phase electron diffraction with MeV electrons.

    Science.gov (United States)

    Yang, Jie; Guehr, Markus; Vecchione, Theodore; Robinson, Matthew S; Li, Renkai; Hartmann, Nick; Shen, Xiaozhe; Coffee, Ryan; Corbett, Jeff; Fry, Alan; Gaffney, Kelly; Gorkhover, Tais; Hast, Carsten; Jobe, Keith; Makasyuk, Igor; Reid, Alexander; Robinson, Joseph; Vetter, Sharon; Wang, Fenglin; Weathersby, Stephen; Yoneda, Charles; Wang, Xijie; Centurion, Martin

    2016-12-16

    We present results on ultrafast gas electron diffraction (UGED) experiments with femtosecond resolution using the MeV electron gun at SLAC National Accelerator Laboratory. UGED is a promising method to investigate molecular dynamics in the gas phase because electron pulses can probe the structure with a high spatial resolution. Until recently, however, it was not possible for UGED to reach the relevant timescale for the motion of the nuclei during a molecular reaction. Using MeV electron pulses has allowed us to overcome the main challenges in reaching femtosecond resolution, namely delivering short electron pulses on a gas target, overcoming the effect of velocity mismatch between pump laser pulses and the probe electron pulses, and maintaining a low timing jitter. At electron kinetic energies above 3 MeV, the velocity mismatch between laser and electron pulses becomes negligible. The relativistic electrons are also less susceptible to temporal broadening due to the Coulomb force. One of the challenges of diffraction with relativistic electrons is that the small de Broglie wavelength results in very small diffraction angles. In this paper we describe the new setup and its characterization, including capturing static diffraction patterns of molecules in the gas phase, finding time-zero with sub-picosecond accuracy and first time-resolved diffraction experiments. The new device can achieve a temporal resolution of 100 fs root-mean-square, and sub-angstrom spatial resolution. The collimation of the beam is sufficient to measure the diffraction pattern, and the transverse coherence is on the order of 2 nm. Currently, the temporal resolution is limited both by the pulse duration of the electron pulse on target and by the timing jitter, while the spatial resolution is limited by the average electron beam current and the signal-to-noise ratio of the detection system. We also discuss plans for improving both the temporal resolution and the spatial resolution.

  10. Neutrino Astrophysics in the MeV band

    Science.gov (United States)

    Ojha, Roopesh; Kadler, Matthias; Mannheim, Karl; Krauss, Felicia; Buson, Sara; Fermi-LAT Collaboration

    2018-01-01

    Photohadronic emission models suggest both neutrinos and gamma-ray photons could be produced by accelerated protons in the relativistic jets of blazars. As the background spectrum falls rapidly with increasing energy, individual events with energies of the order of PeV and above are the best candidates in the search for their astrophysical origin. We present results from our search for possible blazar counterparts to high energy neutrinos detected by IceCube and discuss how such efforts would benefit enormously from observations in the MeV regime.

  11. Status of the BNL 200 MeV Linac

    Energy Technology Data Exchange (ETDEWEB)

    McNerney, A.; Brennan, J.M.; Briscoe, B.; Brodowski, J.; Horton, R.; LoDestro, V.; Montemurro, P.; Zhang, S.Y.

    1986-01-01

    The BNL 200 MeV Linac normally accelerates H/sup -/ ions during its operating schedule. During selected periods, typically of six to ten weeks duration, polarized H/sup -/ ions are accelerated. Since linac H/sup -/ commissioning, longer 7835 tube lives have been recorded and after initial operating bugs were eliminated, preinjector reliability has improved. Hardware components in the Preinjector, rf system, and ion source have been replaced or upgraded, and plans are being implemented for future system improvements. BLIP operations were initially curtailed during polarized beam running and a pulsed magnet has been installed in LEBT to restore BLIP running time to original levels.

  12. Polarization observables in deuteron photodisintegration below 360 MeV

    Energy Technology Data Exchange (ETDEWEB)

    Glister, J., E-mail: jglister@jlab.or [Saint Mary' s University, Halifax, Nova Scotia B3H 3C3 (Canada); Dalhousie University, Halifax, Nova Scotia B3H 3J5 (Canada); Ron, G. [Tel Aviv University, Tel Aviv 69978 (Israel); Lee, B.W. [Seoul National University, Seoul 151-747 (Korea, Republic of); Gilman, R. [Thomas Jefferson National Accelerator Facility, Newport News, VA 23606 (United States); Rutgers, The State University of New Jersey, Piscataway, NJ 08855 (United States); Sarty, A.J. [Saint Mary' s University, Halifax, Nova Scotia B3H 3C3 (Canada); Strauch, S. [University of South Carolina, Columbia, SC 29208 (United States); Higinbotham, D.W. [Thomas Jefferson National Accelerator Facility, Newport News, VA 23606 (United States); Piasetzky, E. [Tel Aviv University, Tel Aviv 69978 (Israel); Allada, K. [University of Kentucky, Lexington, KY 40506 (United States); Armstrong, W. [Temple University, Philadelphia, PA 19122 (United States); Arrington, J. [Argonne National Laboratory, Argonne, IL 60439 (United States); Arenhoevel, H. [Institut fuer Kernphysik, Johannes Gutenberg-Universitaet, D-55099 Mainz (Germany); Beck, A. [NRCN, P.O. Box 9001, Beer-Sheva 84190 (Israel); Benmokhtar, F. [University of Maryland, Baltimore, MD (United States); Berman, B.L. [George Washington University, Washington, DC 20052 (United States); Boeglin, W. [Florida International University, Miami, FL 33199 (United States); Brash, E. [Christopher Newport University, Newport News, VA 23606 (United States); Camsonne, A. [Thomas Jefferson National Accelerator Facility, Newport News, VA 23606 (United States); Calarco, J. [University of New Hampshire, Durham, NH 03824 (United States); Chen, J.P. [Thomas Jefferson National Accelerator Facility, Newport News, VA 23606 (United States)

    2011-03-07

    High precision measurements of induced and transferred recoil proton polarization in d({gamma}{yields},p{yields})n have been performed for photon energies of 277-357 MeV and {theta}{sub cm}=20{sup o}-120{sup o}. The measurements were motivated by a longstanding discrepancy between meson-baryon model calculations and data at higher energies. At the low energies of this experiment, theory continues to fail to reproduce the data, indicating that either something is missing in the calculations and/or there is a problem with the accuracy of the nucleon-nucleon potential being used.

  13. Improved source and transport of monoenergetic MeV positrons

    Science.gov (United States)

    Selim, F. A.; Hunt, A. W.; Golovchenko, J. A.; Howell, R. H.; Haakenaasen, R.; Lynn, K. G.

    2000-08-01

    A new monoenergetic MeV positron beam source was designed and constructed at the Lawrence Livermore National Laboratory (LLNL) positron facility. The positron source provides a low emittance beam with high energy resolution for channeling, scattering, and in-flight annihilation experiments. New beam optics for extracting slow positrons from a moderator mounted in a Pelletron electrostatic accelerator is presented. A beam line was designed and constructed to energy analyze the output of the accelerator and to provide adjustable size and angular divergence beams to a target station. A post target large angle acceptance magnet separates positrons transmitted through the target from forward gamma ray emission.

  14. FDG at 7.8 MeV

    DEFF Research Database (Denmark)

    Jensen, Mikael

    2017-01-01

    I here report the fundamental performance of a new generation of compact medical cyclotrons for hospital-based PET tracer manufacture, exemplified with the FDG production numbers achieved by the first prototype of the GE GenTrace cyclotron. The proton energy is 7.8 MeV. After 3 years of extensive...... testing in a "physics lab" setting, which is door-to-door with our normal GMP production suite, I can now conclude that this cyclotron in conjunction with a standard GE Fastlab chemistry box easily achieves significant, reliable and compliant FDG output surpassing 15 GBq per batch at EOS, after 2 hours...

  15. Radiation Monitoring System of 30 MeV Cyclotron

    Directory of Open Access Journals (Sweden)

    Lee Jin-Woo

    2017-01-01

    Full Text Available A state-of-the-art radiation monitoring system was implemented at KAERI for a 30-MeV cyclotron. This system consists of several types of radiation measuring systems for ambient dose equivalent rate measurements of outside photon and neutron areas as well as inside the cyclotron, and monitors the alpha and beta particulates released from a stack, as well as the results of worker contamination at the portal of the cyclotron. In addition, an automatic alarm system is also mounted if there are alarms in the measuring systems.

  16. 160 MeV $H^-$ Injection into the CERN PSB

    CERN Document Server

    Weterings, W; Borburgh, J; Fowler, T; Gerigk, F; Goddard, B; Hanke, K; Martini, M; Sermeus, L

    2007-01-01

    The H- beam from the proposed LINAC4 will be injected into the four existing rings of the PS Booster at 160 MeV. A substantial upgrade of the injection region is required, including the modification of the beam distribution system and the construction of a new H- injection system. This paper discusses beam dynamics and hardware requirements and presents the results of optimisation studies of the injection process for different beam characteristics and scenarios. The resulting conceptual design of the injection region is presented, together with the main hardware modifications and performance specifications.

  17. The hidden dynamics of relativistic electrons (0.7-1.5 MeV) in the inner zone and slot region

    Science.gov (United States)

    Claudepierre, S. G.; O'Brien, T. P.; Fennell, J. F.; Blake, J. B.; Clemmons, J. H.; Looper, M. D.; Mazur, J. E.; Roeder, J. L.; Turner, D. L.; Reeves, G. D.; Spence, H. E.

    2017-03-01

    We present measurements of relativistic electrons (0.7-1.5 MeV) in the inner zone and slot region obtained by the Magnetic Electron and Ion Spectrometer (MagEIS) instrument on Van Allen Probes. The data presented are corrected for background contamination, which is primarily due to inner-belt protons in these low-L regions. We find that ˜1 MeV electrons were transported into the inner zone following the two largest geomagnetic storms of the Van Allen Probes era to date, the March and June 2015 events. As ˜1 MeV electrons were not observed in Van Allen Probes data in the inner zone prior to these two events, the injections created a new inner belt that persisted for at least 1.5 years. In contrast, we find that electrons injected into the slot region decay on much faster timescales, approximately tens of days. Furthermore, we find no evidence of >1.5 MeV electrons in the inner zone during the entire time interval considered (April 2013 through September 2016). The energies we examine thus span a transition range in the steeply falling inner zone electron spectrum, where modest intensities are observed at 0.7 MeV, and no electrons are observed at 1.5 MeV. To validate the results obtained from the background corrected flux measurements, we also present detailed pulse-height spectra from individual MagEIS detectors. These measurements confirm our results and also reveal low-intensity inner zone and slot region electrons that are not captured in the standard background corrected data product. Finally, we briefly discuss efforts to refine the upper limit of inner zone MeV electron flux obtained in earlier work.

  18. Cross sections of the pp→ ppπ 0 reaction between 310 and 425 MeV

    Science.gov (United States)

    Bilger, R.; Brodowski, W.; Calén, H.; Clement, H.; Dyring, J.; Ekström, C.; Fäldt, G.; Fransson, K.; Greiff, J.; Gustafsson, L.; Höistad, B.; Jacewicz, M.; Johanson, J.; Johansson, A.; Johansson, T.; Kilian, K.; Koch, I.; Kullander, S.; Kupsc, A.; Marciniewski, P.; Morosov, B.; Oelert, W.; Ruber, R. J. M. Y.; Sundberg, P.; Shwartz, B.; Stepaniak, J.; Sukhanov, A.; Thörngren-Engblom, P.; Turowiecki, A.; Wagner, G. J.; Wilhelmi, Z.; Wilkin, C.; Zabierowski, J.; Złomańczuk, J.

    2001-10-01

    Extensive kinematically complete measurements of the pp→ ppπ 0 reaction have been made at six beam energies: 310, 320, 340, 360, 400, and 425 MeV. Angles and energies of both final-state protons are extracted from the forward detector system of the WASA-CELSIUS apparatus. Projected one-parameter distributions of the centre-of-momentum pion angle and the angle of the two-proton relative momentum show significant deviations from isotropy. The slope in the pion angular distribution changes from being negative at 310 MeV to positive at 425 MeV. These distributions, and that of the two-proton relative momentum, are described in terms of partial waves corresponding to the Ss,Ps,Pp,Sd and Ds final states. Commonly used amplitudes, derived from their simple threshold behaviour, fail to reproduce the data at the higher energies. However, in a DWBA treatment, assuming interaction ranges related either to π or ρ exchange, we find acceptable agreement, though the longer range of pion exchange provides significantly better description of the Ps and Pp waves.

  19. Cross sections of the pp{yields}pp{pi}{sup 0} reaction between 310 and 425 MeV

    Energy Technology Data Exchange (ETDEWEB)

    Bilger, R.; Brodowski, W.; Calen, H.; Clement, H.; Dyring, J.; Ekstroem, C.; Faeldt, G.; Fransson, K.; Greiff, J.; Gustafsson, L.; Hoeistad, B.; Jacewicz, M.; Johanson, J.; Johansson, A.; Johansson, T.; Kilian, K.; Koch, I.; Kullander, S.; Kupsc, A.; Marciniewski, P.; Morosov, B.; Oelert, W.; Ruber, R.J.M.Y.; Sundberg, P.; Shwartz, B.; Stepaniak, J.; Sukhanov, A.; Thoerngren-Engblom, P.; Turowiecki, A.; Wagner, G.J.; Wilhelmi, Z.; Wilkin, C.; Zabierowski, J.; Zlomanczuk, J. E-mail: jozef@tsl.uu.se

    2001-10-22

    Extensive kinematically complete measurements of the pp{yields}pp{pi}{sup 0} reaction have been made at six beam energies: 310, 320, 340, 360, 400, and 425 MeV. Angles and energies of both final-state protons are extracted from the forward detector system of the WASA-CELSIUS apparatus. Projected one-parameter distributions of the centre-of-momentum pion angle and the angle of the two-proton relative momentum show significant deviations from isotropy. The slope in the pion angular distribution changes from being negative at 310 MeV to positive at 425 MeV. These distributions, and that of the two-proton relative momentum, are described in terms of partial waves corresponding to the Ss,Ps,Pp,Sd and Ds final states. Commonly used amplitudes, derived from their simple threshold behaviour, fail to reproduce the data at the higher energies. However, in a DWBA treatment, assuming interaction ranges related either to {pi} or {rho} exchange, we find acceptable agreement, though the longer range of pion exchange provides significantly better description of the Ps and Pp waves.

  20. INDEPENDENT AND CUMULATIVE YIELDS OF VERY NEUTRON-RICH NUCLEI IN 20 MEV P-INDUCED AND 18-41 MEV D-INDUCED FISSION OF U-238

    NARCIS (Netherlands)

    LEINO, M; JAUHO, PP; AYSTO, J; DECROCK, P; DENDOOVEN, P; ESKOLA, K; HUYSE, M; JOKINEN, A; PARMONEN, JM; PENTTILA, H; REUSEN, G; TASKINEN, P; VANDUPPEN, P; WAUTERS, J

    Independent and cumulative yields in nearly symmetric fission have been measured for the first time by bombarding U-238 with 20-MeV protons and with 18-, 25-, and 41-MeV deuterons. Isobaric charge dispersion has been determined in the A = 110, A = 112, and A = 114 mass chains and, from asymmetric

  1. Nucleon-induced reactions at intermediate energies: new data at 96 MeV and theoretical status

    Energy Technology Data Exchange (ETDEWEB)

    Blideanu, V.; Lecolley, F.R.; Lecolley, J.F.; Lefort, T.; Marie, N.; Ban, G.; Louvel, M. [Caen Univ., Lab. de Physique Corpusculaire, ENSICAEN, IN2P3-CNRS ISMRA, 14 (France); Atac, A.; Bergenwall, B.; Blomgren, J.; Dangtip, S.; Hildebrand, A.; Hohansson, C.; Klug, J.; Nilsson, L.; Ollson, N.; Pomp, S.; Tippawan, U.; Osterlund, M. [Uppsala Univ., Nykoeping (Sweden). Dept. of Neutron Research; Tippawan, U. [Chiang Mai University, Fast Neutron Research Facility (Thailand); Elmgren, K.; Olsson, N. [Swedish Defense Research Agency, Stokholm (Sweden); Eudes, Ph.; Guertin, A.; Haddad, F.; Kirchner, T.; Lebrun, C.; Riviere, G. [Nantes Univ., Subatech, 44 (France); Foucher, Y. [CEA Saclay, Dept. d' Astrophysique, de Physique des Particules de Physique Nucleaire et de l' Instrumentation Associee, 91- Gif sur Yvette (France); Jonsson, O.; Prokofiev, A.V.; Renberg, P.U. [Uppsala Univ., Svedberg Laboratory (Sweden); Kerveno, M.; Stuttge, L. [IReS, Strasbourg (France); Le Brun, Ch. [Laboratoire de Physique Subatomique et de Cosmologie, 38 - Grenoble (France); Nadel-Turonski, P. [Uppsala Univ. (Sweden). Dept. of Radiation Sciences; Slypen, I. [Universite Catholique de Louvain (UCL), Institut de Physique Nucleaire, Louvain-la-Neuve (Belgium)

    2004-04-01

    Double-differential cross sections for light charged particle production (up to A = 4) were measured in 96 MeV neutron-induced reactions, at TSL laboratory cyclotron in Uppsala (Sweden). Measurements for three targets, Fe, Pb, and U, were performed using two independent devices, SCANDAL and MEDLEY. The data were recorded with low energy thresholds and for a wide annular range (20 - 160 degrees). The normalization procedure used to extract the cross sections is based on the np elastic scattering reaction that we measured and for which we present experimental results. A good control of the systematic uncertainties affecting the results is achieved. Calculations using the exciton model are reported. Two different theoretical approaches proposed to improve its predictive power regarding the complex particle emission are tested. The capabilities of each approach is illustrated by comparison with the 96 MeV data that we measured, and with other experimental results available in the literature. (authors)

  2. Nucleon-induced reactions at intermediate energies: New data at 96 MeV and theoretical status

    Science.gov (United States)

    Blideanu, V.; Lecolley, F. R.; Lecolley, J. F.; Lefort, T.; Marie, N.; Ataç, A.; Ban, G.; Bergenwall, B.; Blomgren, J.; Dangtip, S.; Elmgren, K.; Eudes, Ph.; Foucher, Y.; Guertin, A.; Haddad, F.; Hildebrand, A.; Johansson, C.; Jonsson, O.; Kerveno, M.; Kirchner, T.; Klug, J.; Le Brun, Ch.; Lebrun, C.; Louvel, M.; Nadel-Turonski, P.; Nilsson, L.; Olsson, N.; Pomp, S.; Prokofiev, A. V.; Renberg, P.-U.; Rivière, G.; Slypen, I.; Stuttgé, L.; Tippawan, U.; Österlund, M.

    2004-07-01

    Double-differential cross sections for light charged particle production (up to A=4 ) were measured in 96 MeV neutron-induced reactions, at the TSL Laboratory Cyclotron in Uppsala (Sweden). Measurements for three targets, Fe , Pb , and U , were performed using two independent devices, SCANDAL and MEDLEY. The data were recorded with low-energy thresholds and for a wide angular range ( 20° 160° ) . The normalization procedure used to extract the cross sections is based on the np elastic scattering reaction that we measured and for which we present experimental results. A good control of the systematic uncertainties affecting the results is achieved. Calculations using the exciton model are reported. Two different theoretical approaches proposed to improve its predictive power regarding the complex particle emission are tested. The capabilities of each approach is illustrated by comparison with the 96 MeV data that we measured, and with other experimental results available in the literature.

  3. Extension of activation cross section data of deuteron induced nuclear reactions on rhodium up to 50 MeV

    Energy Technology Data Exchange (ETDEWEB)

    Hermanne, A. [Cyclotron Laboratory, Vrije Universiteit Brussel, Brussels (Belgium); Tárkányi, F.; Takács, S.; Ditrói, F. [Institute of Nuclear Research of the Hungarian Academy of Sciences, Debrecen (Hungary)

    2015-11-01

    In the frame of the systematical study of light ion induced nuclear reactions activation cross sections for deuteron induced reactions on monoisotopic {sup 103}Rh were extended to 50 MeV incident energy. Excitation functions were measured in the 49.8–36.6 MeV energy range for the {sup 103}Rh(d,xn){sup 100,101}Pd, {sup 103}Rh(d,pxn){sup 99m,99g,100,101m,101g,102m,102g}Rh and {sup 103}Rh(d,x){sup 97,103}Ru reactions by using the stacked foil irradiation technique and off-line high resolution γ-ray spectrometry. The experimental results are compared to our previous results and to the theoretical predictions in the TENDL-2014 library (TALYS 1.6 code).

  4. Incident particle range dependence of radiation damage in a power bipolar junction transistor

    Science.gov (United States)

    Liu, Chao-Ming; Li, Xing-Ji; Geng, Hong-Bin; Rui, Er-Ming; Guo, Li-Xin; Yang, Jian-Qun

    2012-10-01

    The characteristic degradations in silicon NPN bipolar junction transistors (BJTs) of type 3DD155 are examined under the irradiations of 25-MeV carbon (C), 40-MeV silicon (Si), and 40-MeV chlorine (Cl) ions respectively. Different electrical parameters are measured in-situ during the exposure of heavy ions. The experimental data shows that the changes in the reciprocal of the gain variation (Δ(1/β)) of 3DD155 transistors irradiated respectively by 25-MeV C, 40-MeV Si, and 40-MeV Cl ions each present a nonlinear behaviour at a low fluence and a linear response at a high fluence. The Δ(1/β) of 3DD155 BJT irradiated by 25-MeV C ions is greatest at a given fluence, a little smaller when the device is irradiated by 40-MeV Si ions, and smallest in the case of the 40-MeV Cl ions irradiation. The measured and calculated results clearly show that the range of heavy ions in the base region of BJT affects the level of radiation damage.

  5. Measurement of the e(+)e(-) -> pi(+) pi(-) cross section between 600 and 900 MeV using initial state radiation

    NARCIS (Netherlands)

    Ablikim, M.; Achasov, M. N.; Ai, X.C.; Albayrak, O.; Albrecht, M.; Ambrose, D.J.; Amoroso, A.; Haddadi, Z.; Kalantar-Nayestanaki, N.; Kavatsyuk, M.; Loehner, H.; Messchendorp, J.G.; Tiemens, M.

    2016-01-01

    We extract the e(+) e(-) -> pi(+) pi(-) cross section in the energy range between 600 and 900 MeV, exploiting the method of initial state radiation. A data set with an integrated luminosity of 2.93 fb(-1) taken at a center-of-mass energy of 3.773 GeV with the BESIII detector at the BEPCII collider

  6. Experimental evaluation of the response of micro-channel plate detector to ions with 10s of MeV energies

    OpenAIRE

    Jeong, Tae Won; Singh, P. K.; Scullion, C.; Ahmed, H.; Kakolee, K. F.; Hadjisolomou, P.; Alejo, A.; Kar, S.; Borghesi, M.; Ter-Avetisyan, S.

    2016-01-01

    The absolute calibration of a microchannel plate (MCP) assembly using a Thomson spectrometer for laser-driven ion beams is described. In order to obtain the response of the whole detection system to the particles’ impact, a slotted solid state nuclear track detector (CR-39) was installed in front of the MCP to record the ions simultaneously on both detectors. The response of the MCP (counts/particles) was measured for 5–58 MeV carbon ions and for protons in the energy range2–17.3 MeV. The res...

  7. Limitations of 14 MeV neutron simulation techniques

    Science.gov (United States)

    Kley, W.; Bishop, G. R.; Sinha, A.

    1988-07-01

    A D-T fusion cycle produces five times more neutrons per unit of energy released than a fission cycle, with about twice the damage energy and the capability to produce ten times more hydrogen, helium and transmutation products than fission neutrons. They determine, together with other parameters, the lifetime of the construction materials for the low plasma-density fusion reactors (tokamak, tandem-mirror, etc.), which require a first wall. For the economie feasibility of fusion power reactors the first wall and blanket materials must withstand a dose approaching 300 to 400 dpa. Arguments are presented that demonstrate that today's simulation techniques using existing fission reactors and charged particle beams are excellent tools to study the underlying basic physical phenomena of the evolving damage structures but are not sufficient to provide a valid technological data base for the design of economie fusion power reactors. It is shown than an optimized spallation neutron source based on a continuous beam of 600 MeV, 6 mA protons is suitable to simulate first wall conditions. Comparing it with FMIT the 35 MeV, 100 mA D + -Li neutron source, we arrive at the following figure of merit: FM = {(dpa·volume) EURAC}/{(dpa·volume) FMIT} = {} = 111 reflecting the fact that the proton beam generates about 100 times more neutrons than the deuteron beam in FMIT for the same beam power.

  8. Risk assessment of 30 MeV cyclotron facilities

    Energy Technology Data Exchange (ETDEWEB)

    Jeong, Gyo Seong; Lee, Jin Woo [Advanced Radiation Technology Institute, Korea Atomic Energy Research Institute, Jeongeup (Korea, Republic of); Kim, Chong Yeal [Dept. of Radiation Science and Technology, Chonbuk National University, Jeonju (Korea, Republic of)

    2017-03-15

    A cyclotron is a kind of particle accelerator that produces a beam of charged particles for the production of medical, industrial, and research radioisotopes. More than 30 cyclotrons are operated in Korea to produce 18F, an FDG synthesis at hospitals. A 30-MeV cyclotron was installed at ARTI (Advanced Radiation Technology Institute, KAERI) mainly for research regarding isotope production. In this study, we analyze and estimate the items of risk such as the problems in the main components of the cyclotron, the loss of radioactive materials, the leakage of coolant, and the malfunction of utilities, fres and earthquakes. To estimate the occurrence frequency in an accident risk assessment, five levels, i.e., Almost certain, Likely, Possible, Unlikely, and Rare, are applied. The accident consequence level is classified under four grades based on the annual permissible dose for radiation workers and the public in the nuclear safety law. The analysis of the accident effect is focused on the radioactive contamination caused by radioisotope leakage and radioactive material leakage of a ventilation filter due to a free. To analyze the risks, Occupation Safety and Health Acts is applied. In addition, action plans against an accident were prepared after a deep discussion among relevant researchers. In this acts, we will search for hazard and introduce the risk assessment for the research 30-MeV cyclotron facilities of ARTI.

  9. Recoil properties of antimony isotopes produced by the reaction of 570 MeV and 18.2 GeV protons with uranium

    CERN Document Server

    Hagebø, E

    1969-01-01

    Using the method of thick target and thick catchers, the ranges and other recoil properties of 13 (12) antimony isotopes between A = 115 and A = 131 (130) have been measured for the reaction of 570 MeV (18·2 GeV) protons with uranium. The kinetic energies T are almost independent of product mass number at 570 MeV but show a strong dependence at 18·2 GeV, the lightest isotopes having only about half the kinetic energy of the heavy ones. \\\\ \\\\The cascade deposition energies for production of antimony isotopes are almost equal at 570 MeV and 18·2 GeV and fit well to straight lines of the form E$^{∗}$ (A, Z) = E$^{∗}$ (A$_{0}$, Z) + b(A − A$_{0}$). Exceptions are the cascade deposition energies for $^{115}$Sb and $^{116}$Sb which seem to be somewhat too high at 18·2 GeV. By comparison with other work it seems that the slope $b$ of these lines is independent of product element, target and of proton irradiation energy above 450 MeV. \\\\ \\\\If we assume at 570 MeV, that the fissioning nucleus is a uranium ...

  10. Measurement and theoretical analysis of neutron-induced neutron-emission reactions of {sup 6}Li at 10 to 20 MeV region

    Energy Technology Data Exchange (ETDEWEB)

    Ibaraki, Masanobu; Baba, Mamoru; Matsuyama, Shigeo [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment] [and others

    1998-06-01

    We have measured the neutron elastic and inelastic scattering double-differential cross sections of {sup 6}Li at incident neutron energies of 11.5, 14.1 and 18.0 MeV. Based on this data, together with information from other works, a phenomenological neutron optical model potential (OMP) of {sup 6}Li was constructed to describe the total and elastic scattering cross sections from 5 MeV to several tens MeV. This potential also describes well the inelastic scattering to the 1st excited state (E{sub x} = 2.186 MeV) via the DWBA calculation with the macroscopic vibrational model. The continuum neutron energy spectra and angular distributions were then analyzed by the theory of final-state interaction extended to the DWBA form, with the assumption that the d-{alpha} interaction is dominant in the 3-body final state consisting of n, d and {alpha} particles. Such a calculation was found to be successful in explaining the major part of the low-excitation neutron spectra and angular distribution down to the Q-value region of -9 MeV, except for the Q-value range where the n-{alpha} quasi-free scattering will give a non-negligible contribution at forward angles. (author). 60 refs.

  11. Simultaneous quiet time observations of energetic radiation belt protons and helium ions - The equatorial alpha/p ratio near 1 MeV

    Science.gov (United States)

    Fritz, T. A.; Spjeldvik, W. N.

    1979-01-01

    Simultaneous monitoring of energetic helium ions and protons in the earth's radiation belts has been conducted with Explorer 45 in the immediate vicinity of the equatorial plane. Protons were measured from less than 1 keV to 1.6 MeV and also above 3.3 MeV in a channel responsive up to 22 MeV; helium ions were monitored in three passbands: 910 keV to 3.15 MeV, 590 to 910 keV, and 2.0 to 3.99 MeV. Alpha/proton flux ratios were found to vary significantly with energy and location in the radiation belts. At equal energy per nucleon a range of variability for alpha/p from 0.0001 to well above 0.001 was found, and at equal energy per ion the corresponding variability was from 0.001 to above 10. The latter findings emphasize the relative importance of the very energetic helium ions in the overall radiation belt ion populations.

  12. Cross-sections for sup 3 sup 6 Cl from Ti at E sub p =35-150 MeV Applications to in-situ exposure dating

    CERN Document Server

    Fink, D; Hotchkis, M

    2000-01-01

    We have measured the low-energy yield of sup 3 sup 6 Cl from Ti for proton energies from 35 to 150 MeV. Thin Ti foil irradiations were performed at the Harvard University Cyclotron Laboratory and sup 3 sup 6 Cl concentrations were determined using the ANTARES AMS facility at ANSTO. Cross-sections ranged smoothly with energy from 0.32+-0.05 mb at 35 MeV to 5.3+-0.4 mb at 150 MeV. Results for E<110 MeV are new, while the upper region from 110 to 150 MeV agrees well with overlapping data from other studies. The in-situ production rate for sup 3 sup 6 Cl from Ti at the earth's surface and high latitude based on this excitation function and calculations of Masarik and Reedy (normalised to the mean measured yield of sup 3 sup 6 Cl from Ca) is estimated at approx(13+-3) atoms sup 3 sup 6 Cl (g Ti yr) sup - sup 1. We thus conclude that in Ti-rich, Ca-poor rocks or in typical basalts, sup 3 sup 6 Cl yield from Ti can amount to approx 5-10% of total. This is similar to the contribution from slow muon capture on sup ...

  13. Measurement of the (236)U(n,f) cross section from 170 MeV to 2 MeV at the CERN n_TOF Facility

    Energy Technology Data Exchange (ETDEWEB)

    Sarmento, R. [Instituto Tecnologico e Nuclear, Sacavem, Portugal; Goncalves, I. F. [Instituto Tecnologico e Nuclear, Sacavem, Portugal; Vaz, P. [Instituto Tecnologico e Nuclear (ITN), Lisbon, Portugal; Carrapico, C. [Instituto Tecnologico e Nuclear (ITN), Lisbon, Portugal; Carrillo de Albornoz, A. [Instituto Tecnologico e Nuclear, Sacavem, Portugal; Marques, L. [Instituto Tecnologico e Nuclear, Sacavem, Portugal; Salgado, J. [Instituto Tecnologico e Nuclear, Sacavem, Portugal; Tavora, L. [Instituto Tecnologico e Nuclear, Sacavem, Portugal; Calviani, M. [CERN, Geneva, Switzerland; Andriamonje, S. [CERN, Geneva, Switzerland; Chiaveri, E. [CERN, Geneva, Switzerland; Guerrero, C. [CERN, Geneva, Switzerland; Vlachoudis, V. [CERN, Geneva, Switzerland; Colonna, N. [Instituto Nazionale di Fisica Nucleare, Bari, Italy; Barbagallo, M. [Instituto Nazionale di Fisica Nucleare, Bari, Italy; Marrone, S. [Instituto Nazionale di Fisica Nucleare, Bari, Italy; Tagliente, G. [Instituto Nazionale di Fisica Nucleare, Bari, Italy; Terlizzi, R. [Instituto Nazionale di Fisica Nucleare, Bari, Italy; Belloni, F. [Instituto Nazionale de Fisica Nucleare, Trieste, Italy; Fuji, K. [Instituto Nazionale de Fisica Nucleare, Trieste, Italy; Milazzo, P. M. [Instituto Nazionale de Fisica Nucleare, Trieste, Italy; Moreau, C. [Instituto Nazionale de Fisica Nucleare, Trieste, Italy; Alvarez-Velarde, F. [Centro de Investigaciones Energeticas Medioambientales y Technol., Madrid, Spain; Cano-Ott, D. [CIEMAT, Madrid; Gonzalez-Romero, E. [CIEMAT, Madrid; Guerrero, C. [Centro de Investigaciones Energeticas Medioambientales y Technol., Madrid, Spain; Martinez, T. [Centro de Investigaciones Energeticas Medioambientales y Technol., Madrid, Spain; Mendoza, E. [Centro de Investigaciones Energeticas Medioambientales y Technol., Madrid, Spain; Villamarin, D. [Centro de Investigaciones Energeticas Medioambientales y Technol., Madrid, Spain; Vicente, M. C. [Centro de Investigaciones Energeticas Medioambientales y Technol., Madrid, Spain; Andrzejewski, Jozef [ORNL; Karamanis, D. [University of Ioannina, Greece; Marganiec, J. [University of Lodz; Assimakopoulos, P. A. [University of Ioannina, Greece; Karadimos, D. [University of Ioannina, Greece; Papachristodoulou, C. [University of Ioannina, Greece; Patronis, N. [University of Ioannina, Greece; Audouin, L. [Universite Paris XI, Orsay, France; David, S. [CNRS, Orsay, France; Ferrant, L. [Universite Paris XI, Orsay, France; Isaev, S. [CNRS/IN2P3, Orsay, France; Stephan, C. [CNRS/IN2P3, Orsay, France; Tassan-Got, L. [CNRS/IN2P3, Orsay, France; Badurek, G. [Vienna University of Technology, Austria; Jericha, E. [Vienna University of Technology, Austria; Leeb, H. [Vienna University of Technology, Austria; Oberhummer, H. [Vienna University of Technology, Austria; Pigni, M. T. [Vienna University of Technology, Austria; Baumann, P. [CNRS, Strasbourg, France; Kerveno, M. [CNRS, Strasbourg, France; Lukic, S. [CNRS, Strasbourg, France; Rudolf, G. [CNRS, Strasbourg, France; Becvar, F. [Charles University, Prague, Czech Republic; Krticka, M. [Charles University, Prague, Czech Republic; Calvino, F. [Universidad Politecnica de Madrid, Spain; Capote, R. [International Atomic Energy Agency (IAEA); Frais-Koelbl, H. [International Atomic Energy Agency (IAEA); Griesmayer, E. [International Atomic Energy Agency (IAEA); Mengoni, A. [International Atomic Energy Agency (IAEA); Praena, J. [University of Seville; Capote, R. [University of Seville; Lozano, M. [University of Seville; Quesada, J. [University of Seville; Cennini (et al.), P. [INFN, Laboratori Nazionali di Legnaro, Italy; Chapel, V. [University of Ciombra, Portugal; Ferreira-Marques, R. [University of Ciombra, Portugal; Lindote, A. [University of Ciombra, Portugal; Lopes, I. [University of Ciombra, Portugal; Neves, F. [University of Ciombra, Portugal; et al.

    2011-01-01

    The neutron-induced fission cross section of {sup 236}U was measured at the neutron Time-of-Flight (n-TOF) facility at CERN relative to the standard {sup 235}U(n,f) cross section for neutron energies ranging from above thermal to several MeV. The measurement, covering the full range simultaneously, was performed with a fast ionization chamber, taking advantage of the high resolution of the n-TOF spectrometer. The n-TOF results confirm that the first resonance at 5.45 eV is largely overestimated in some nuclear data libraries. The resonance triplet around 1.2 keV was measured with high resolution and resonance parameters were determined with good accuracy. Resonances at high energy have also been observed and characterized and different values for the cross section are provided for the region between 10 keV and the fission threshold. The present work indicates various shortcomings of the current nuclear data libraries in the subthreshold region and provides the basis for an accurate re-evaluation of the {sup 236}U(n,f) cross section, which is of great relevance for the development of emerging or innovative nuclear reactor technologies.

  14. Disintegration of {sup 12}C nuclei by 700–1500 MeV photons

    Energy Technology Data Exchange (ETDEWEB)

    Nedorezov, V. [Institute for Nuclear Research, Russian Academy of Sciences, Prospekt 60-letiya Oktyabrya 7a, 117312 Moscow (Russian Federation); D' Angelo, A.; Bartalini, O. [Dipartimento di Fisica – Università degli Studi di Roma “Tor Vergata”, via della Ricerca Scientifica 1, I-00133 Roma (Italy); INFN – Sezione di Roma “Tor Vergata”, via della Ricerca Scientifica 1, I-00133 Roma (Italy); Bellini, V. [Dipartimento di Fisica – Università degli Studi di Catania, via Santa Sofia 64, I-95123 Catania (Italy); INFN – Sezione di Catania, via Santa Sofia 64, I-95123 Catania (Italy); Capogni, M. [Dipartimento di Fisica – Università degli Studi di Roma “Tor Vergata”, via della Ricerca Scientifica 1, I-00133 Roma (Italy); INFN – Sezione di Roma “Tor Vergata”, via della Ricerca Scientifica 1, I-00133 Roma (Italy); Casano, L.E. [INFN – Sezione di Roma “Tor Vergata”, via della Ricerca Scientifica 1, I-00133 Roma (Italy); Castoldi, M. [Dipartimento di Fisica – Università degli Studi di Genova, via Dodecaneso 33, I-16146 Genova (Italy); Curciarello, F.; De Leo, V. [Dipartimento di Fisica e di Scienze della Terra, Università di Messina, salita Sperone 31, I-98166 Messina (Italy); INFN – Sezione di Catania, via Santa Sofia 64, I-95123 Catania (Italy); Didelez, J.-P. [IN2P3, Institut de Physique Nucléaire, Rue Georges Clemenceau, F-91406 Orsay (France); and others

    2015-08-15

    Disintegration of {sup 12}C nuclei by tagged photons of 700–1500 MeV energy at the GRAAL facility has been studied by means of the LAGRANγE detector with a wide angular acceptance. The energy and momentum distributions of produced neutrons and protons as well as their multiplicity distributions were measured and compared with corresponding distributions calculated with the RELDIS model based on the intranuclear cascade and Fermi break-up models. It was found that eight fragments are created on average once per about 100 disintegration events, while a complete fragmentation of {sup 12}C into 12 nucleons is observed typically only once per 2000 events. Measured multiplicity distributions of produced fragments are well described by the model. The measured total photoabsorption cross section on {sup 12}C in the same energy range is also reported.

  15. Experimental exclusion of neutral resonances in Bhabha scattering at MeV energies

    Science.gov (United States)

    Tsertos, H.; Kienle, P.; Judge, S. M.; Schreckenbach, K.

    1991-08-01

    Using an active-shadow technique and a monoenergetic e + beam at the high-flux reactor of ILL, we pursued the search for long-lived (> 5 × 10 -13 s) neutral resonances that could be formed in e +e - scattering around an invariant mass of 1.8 MeV/ c2. With a significantly improved experimental sensitivity we found no evidence for such a narrow resonance decaying into e +e - pairs. From our whole investigations, the model-independent stringent lower limits (95% CL) of 5 × 10 -11 s and 1 × 10 -10 s can be set on the lifetime of hypothetical J = 0 and J = 1 resonances, respectively. Our conclusive results rule out theoretical proposals that involve neutral free particles or e +e - bound states in this mass range, as an explanation of the e +e - lines observed at GSI.

  16. Effect of low doses of 14 MeV neutrons on polymers.

    Science.gov (United States)

    Rivaton, Agnès; Arnold, Jack; Dos Santos, Morgane; Bussière, Pierre-Olivier; Taviot-Gueho, Christine

    2010-11-01

    The structural modifications of polymers irradiated with 14 MeV neutrons were studied. Two elastomers, a polypropylene-type polymer and poly(ethylene oxide) were exposed to low doses of fast neutrons in the range of 0.3-14 Gy. The radiation damages were observed at the molecular scale by infrared spectroscopy. The morphological changes were investigated by steric exclusion chromatography, insoluble fraction measurements, differential scanning calorimetry and X-ray diffraction. It was found that neutrons provoked oxidation processes accompanied by modifications in the polymer architecture, including chain scissions, crosslinking reactions and changes in the crystallinity. Moreover, the conventional antioxidants were shown to be inefficient in inhibiting the aging of the polymers. These results also suggest that the radiation damages could be used successfully for dosimetry applications using an easily implementable protocol.

  17. Efficient production and diagnostics of MeV proton beams from a cryogenic hydrogen ribbon

    Science.gov (United States)

    Velyhan, A.; Giuffrida, L.; Scuderi, V.; Perin, J. P.; Chatain, D.; Garcia, S.; Bonnay, P.; Dostal, J.; Ullschmied, J.; Dudzak, R.; Krousky, E.; Cykhardt, J.; Prokupek, J.; Pfeifer, M.; Rosinski, M.; Krasa, J.; Brabcova, K.; De Napoli, M.; Lastovicka, T.; Margarone, D.

    2017-06-01

    A solid hydrogen thin ribbon, produced by the cryogenic system ELISE (Experiments on Laser Interaction with Solid hydrogEn) target delivery system, was experimentally used at the PALS kJ-laser facility to generate intense proton beams with energies in the MeV range. This sophisticated target system operating at cryogenic temperature (~ 10 K) continuously producing a 62 μm thick target was combined with a 600 J sub-nanosecond laser pulse to generate a collimated proton stream. The accelerated proton beams were fully characterized by a number of diagnostics. High conversion efficiency of laser to energetic protons is of great interest for future potential applications in non-conventional proton therapy and fast ignition for inertial confinement fusion.

  18. 160 MeV laser-accelerated protons from CH2 nano-targets for proton cancer therapy

    CERN Document Server

    Hegelich, B M; Albright, B J; Cheung, M; Dromey, B; Gautier, D C; Hamilton, C; Letzring, S; Munchhausen, R; Palaniyappan, S; Shah, R; Wu, H -C; Yin, L; Fernández, J C

    2013-01-01

    Proton (and ion) cancer therapy has proven to be an extremely effective even supe-rior method of treatment for some tumors 1-4. A major problem, however, lies in the cost of the particle accelerator facilities; high procurement costs severely limit the availability of ion radiation therapy, with only ~26 centers worldwide. Moreover, high operating costs often prevent economic operation without state subsidies and have led to a shutdown of existing facilities 5,6. Laser-accelerated proton and ion beams have long been thought of as a way out of this dilemma, with the potential to provide the required ion beams at lower cost and smaller facility footprint 7-14. The biggest challenge has been the achievement of sufficient particle energy for therapy, in the 150-250 MeV range for protons 15,16. For the last decade, the maximum exper-imentally observed energy of laser-accelerated protons has remained at ~60 MeV 17. Here we the experimental demonstration of laser-accelerated protons to energies exceeding 150 MeV, re...

  19. Calibration of indium response functions in an Au–In-BSE system up to 800 MeV

    Science.gov (United States)

    Wang, Zhonglu; Howell, Rebecca M.; Burgett, Eric A.; Kry, Stephen F.; Hertel, Nolan E.; Salehpour, Mohammad

    2010-01-01

    Calibration of the response functions of a gold (Au)–indium (In) dual foil Bonner sphere extended (BSE) system was described. The response of the In and Au foil of the system was calculated using MCNPX code with different activation cross-sectional libraries: (ACTL and ENDF VI for gold and ACTL and 532DOS2 for In). To verify and correct the calculated response functions the Bonner sphere set (BSS) was irradiated using 252Cf and 241AmBe sources of known neutron strengths for neutrons ranging from thermal to 20 MeV, and was irradiated at the 800-MeV neutron beam of the Los Alamos Neutron Science Center. The neutron spectrum of the 800 MeV beam was determined using time-of-flight (TOF) technique. We observed that the uncertainty of activation cross section in the resonance region can result in great uncertainty in the MCNPX-calculated response functions of activation foil-based BSS. The MCNPX-calculated response functions must be corrected using neutron sources of known spectrum and strength. PMID:20008907

  20. Measurement of 1.7–74 MeV polarised γ rays with the HARPO TPC

    Energy Technology Data Exchange (ETDEWEB)

    Geerebaert, Y., E-mail: yannick.geerebaert@polytechnique.fr [LLR, École Polytechnique, CNRS/IN2P3, Palaiseau (France); Gros, Ph., E-mail: philippe.gros@llr.in2p3.fr [LLR, École Polytechnique, CNRS/IN2P3, Palaiseau (France); Amano, S. [LASTI, University of Hyôgo (Japan); Attié, D. [CEA, Irfu, CEA-Saclay (France); Bernard, D.; Bruel, P. [LLR, École Polytechnique, CNRS/IN2P3, Palaiseau (France); Calvet, D.; Colas, P. [CEA, Irfu, CEA-Saclay (France); Daté, S. [JASRI/SPring8 (Japan); Delbart, A. [CEA, Irfu, CEA-Saclay (France); Frotin, M.; Giebels, B. [LLR, École Polytechnique, CNRS/IN2P3, Palaiseau (France); Götz, D. [AIM, CEA/DSM-CNRS – Université Paris Diderot (France); IRFU/Service d' Astrophysique, CEA-Saclay (France); Hashimoto, S. [LASTI, University of Hyôgo (Japan); Horan, D. [LLR, École Polytechnique, CNRS/IN2P3, Palaiseau (France); Kotaka, T. [LASTI, University of Hyôgo (Japan); Louzir, M. [LLR, École Polytechnique, CNRS/IN2P3, Palaiseau (France); Minamiyama, Y.; Miyamoto, S. [LASTI, University of Hyôgo (Japan); Ohkuma, H. [JASRI/SPring8 (Japan); and others

    2017-02-11

    Current γ-ray telescopes based on photon conversions to electron-positron pairs, such as Fermi, use tungsten converters. They suffer of limited angular resolution at low energies, and their sensitivity drops below 1 GeV. The low multiple scattering in a gaseous detector gives access to higher angular resolution in the MeV–GeV range, and to the linear polarisation of the photons through the azimuthal angle of the electron-positron pair. HARPO is an R&D programme to characterise the operation of a TPC (Time Projection Chamber) as a high angular-resolution and sensitivity telescope and polarimeter for γ rays from cosmic sources. It represents a first step towards a future space instrument. A 30 cm cubic TPC demonstrator was built, and filled with 2 bar argon-based gas. It was put in a polarised γ-ray beam at the NewSUBARU accelerator in Japan in November 2014. Data were taken at different photon energies from 1.7 MeV to 74 MeV, and with different polarisation configurations. The electronics setup is described, with an emphasis on the trigger system. The event reconstruction algorithm is quickly described, and preliminary measurements of the polarisation of 11 MeV photons are shown.

  1. Development of pulsed MeV positron beam line

    Energy Technology Data Exchange (ETDEWEB)

    Maekawa, Masaki; Kawasuso, Atsuo; Itoh, Hisayoshi [Japan Atomic Energy Research Inst., Takasaki, Gunma (Japan). Takasaki Radiation Chemistry Research Establishment; Masuno, Shinichi [Mitsubishi Electric Engineering Company Limited, Tokyo (Japan); Hirano, Takeshi; Kondo, Masakazu [Mitsubishi Electric Corporation, Tokyo (Japan); Okada, Sohei [Japan Atomic Energy Research Inst., Kashiwa, Chiba (Japan)

    2003-03-01

    We have developed a high-energy pulsed positron beam apparatus employing an RF acceleration method in order to apply positron annihilation lifetime spectroscopy (PALS) studies to bulk materials at high-temperature and/or high-pressure conditions. This apparatus contains a slow positron pulsing system and a radio frequency (RF) acceleration cavity. Performance tests were carried out using electron and positron beams. Beam energy ({approx}1 MeV), s beam size ({phi} 0.5 mm) and a beam transmission are as good as expectations of machine design. In the time structures of accelerated beam, satellite pulses superposed on broad pulses were observed. In order to make PULS measurement using RF cavity, it is important to form a high quality beam with single fine pulses by refine of the bunching system and the RF source driven with high duty ratio. (author)

  2. Focussed MeV ion beam implanted waveguides

    Energy Technology Data Exchange (ETDEWEB)

    Von Bibra, M.L.; Roberts, A.; Nugent, K.; Jamieson, D.N. [Melbourne Univ., Parkville, VIC (Australia). School of Physics

    1996-12-31

    Single mode buried optical waveguides have been fabricated in fused silica by MeV proton implantation using a focussed hydrogen ion beam. The technique has the potential to direct write waveguide devices and produce multi-layered structures, without the need for intermediate steps such as mask fabrication or layered depositions. A micron resolution Confocal Raman Spectrometer has been used to map the distribution of atomic vacancies that forms the waveguiding region. The results are compared with theoretical calculations. Losses of 3 dB cm{sup -1} have been measured in unannealed samples, which decreases to less than 0.5 dB cm{sup -1} after annealing at 500 degrees Celsius. We describe methods for determining the refractive index distribution of single mode buried waveguides from their output intensity distributions via an inversion of the scalar wave equation. (authors). 5 figs.

  3. Multipole Stack for the 800 MeV PS Booster

    CERN Multimedia

    1975-01-01

    The 800 MeV PS Booster had seen first beam in its 4 superposed rings in 1972, routine operation began in 1973. In the strive for ever higher beam intensities, the need for additional multipole lenses became evident. After detailed studies, the manufacture of 8 stacks of multipoles was launched in 1974. Each stack consists of 4 superposed multipoles and each multipole has 4 concentric shells. From the innermost to the outermost shell, Type A contains octupole, skew-octupole, sextupole, skew-sextupole. Type B contains skew-octupole, skew-sextupole, vertical dipole, horizontal dipole. Completion of installation in 1976 opened the way to higher beam intensities. M. Battiaz is seen here with a multipole stack and its many electrical connections.

  4. Design of 10 MeV cyclotron accelerator

    Directory of Open Access Journals (Sweden)

    R Solhju

    2015-09-01

    Full Text Available Design and construction of 10MeV cyclotron has been started at Amirkabir University of Technology since 2012. So far, the conceptual and detail engineering design phases have been finalized. The main purpose of this baby cyclotron is to generate proton beam for the production of PET radioisotopes. The cyclotron consists of magnet, cavity, ion source, RF and LLRF system, vacuum system, cooling system, power amplifiers and power supplies system. In this paper, a brief of design principles for all the parts of cyclotron and their final simulation results is presented. It should be noted that these simulations have been performed and optimized by the most accurate softwares such as TOSCA, ANSYS, HFSS, SolidWorks and CST. Also, the manufacturing feasibility of all the parts is performed and their dimensions and parameters are synchronized with manufacturing standards

  5. Thermal Dark Matter Below a MeV.

    Science.gov (United States)

    Berlin, Asher; Blinov, Nikita

    2018-01-12

    We consider a class of models in which thermal dark matter is lighter than a MeV. If dark matter thermalizes with the standard model below the temperature of neutrino-photon decoupling, equilibration and freeze-out cool and heat the standard model bath comparably, alleviating constraints from measurements of the effective number of neutrino species. We demonstrate this mechanism in a model consisting of fermionic dark matter coupled to a light scalar mediator. Thermal dark matter can be as light as a few keV, while remaining compatible with existing cosmological and astrophysical observations. This framework motivates new experiments in the direct search for sub-MeV thermal dark matter and light force carriers.

  6. Induced photonuclear interaction by Rhodotron-TT200 10 MeV ...

    Indian Academy of Sciences (India)

    with the experimental results to evaluate the reliability of the calculation. The results show that the obtained neutron flux can reach up to 1012 n/cm2/s with average energies of 0.9 MeV, 0.4 MeV and 0.9 MeV for these three elements respectively with the maximum heat deposited as 3000 W/c3,. 4500 W/c3 and 6000 W/c3.

  7. Simulation of dC and dCH{sub 2} reactions from 300 MeV up to 500 MeV of deuteron energy

    Energy Technology Data Exchange (ETDEWEB)

    Janek, M., E-mail: janek@fyzika.uniza.sk [Physics Dept., University of Zilina, 01026 Zilina (Slovakia); Trpisova, B. [Physics Dept., University of Zilina, 01026 Zilina (Slovakia); Ladygin, V.P.; Piyadin, S.M. [Joint Institute for Nuclear Researches, LHEP, 141980 Dubna (Russian Federation)

    2013-12-15

    GEANT4 simulations of dC and dCH{sub 2} reactions at 300 MeV, 400 MeV and 500 MeV of deuteron energy for different detector configurations are presented. Two threads made from polyethylene and carbon are used as targets. The goal of the simulations is to find a method by means of which the signal from the dp non-mesonic breakup reaction can be separated from the background that mainly comes from the carbon content of the targets. The obtained results will be used in the experimental spin program that will be realized in Nuclotron in Dubna.

  8. Search for an elusive 4. 4-MeV. cap alpha. emitter in uranium minerals

    Energy Technology Data Exchange (ETDEWEB)

    Dougan, R.J.; Illige, J.D.; Hulet, E.K.

    1979-12-01

    A search for an unidentified 4.4-MeV ..cap alpha..-emitter in Belgian Congo pitchblende and uranium raffinates is described, and a history of observations of 4.4-MeV activity over the last 55 years in radiogenic haloes, zinc ores, monazite, thorite, huttonite, ultrabasic and other abyssal rocks, osmiridium, uranium ores, and raffinates of uranium is given. No evidence of excess 4.4-MeV activity was shown in any of the chemically separated fractions investigated. Upper limits for 4.4-MeV ..cap alpha.. activity in each of four studied samples are given.

  9. Monte Carlo 20 and 45 MeV Bremsstrahlung and dose-reduction calculations

    Energy Technology Data Exchange (ETDEWEB)

    Goosman, D.R.

    1984-08-14

    The SANDYL electron-photon coupled Monte Carlo code has been compared with previously published experimental bremsstrahlung data at 20.9 MeV electron energy. The code was then used to calculate forward-directed spectra, angular distributions and dose-reduction factors for three practical configurations. These are: 20 MeV electrons incident on 1 mm of W + 59 mm of Be, 45 MeV electrons of 1 mm of W and 45 MeV electrons on 1 mm of W + 147 mm of Be. The application of these results to flash radiography is discussed. 7 references, 12 figures, 1 table.

  10. Neutron-induced fission cross sections of uraniums up to 40 MeV

    Energy Technology Data Exchange (ETDEWEB)

    Maslov, V.M. [Radiation Physics and Chemistry Problems Inst., Minsk-Sosny (Belarus); Hasegawa, A.

    1998-11-01

    Statistical theory of nuclear reactions, well-proved below 20 MeV, is applied for {sup 235}U and {sup 238}U fission data analysis up to {approx}40 MeV. It is shown that measured data could be reproduced. Chance structure of measured fission cross section is provided, it`s validity is supported by description of data for competing (n,xn)-reactions. Role of fissility of target nucleus is addressed. It seems that gap in incident neutron energy interval of 20 MeV - 50 MeV, below which evaluation approaches are well-developed, and above which simplified statistical approaches are valid, could be covered. (author)

  11. 100 MeV silver ions induced defects and modifications in silica glass

    Energy Technology Data Exchange (ETDEWEB)

    Jadhav, Vijay S.; Deore, Avinash V.; Dahiwale, S.S. [Department of Physics, University of Pune, Pune 411007 (India); Kanjilal, D. [Inter University Accelerator Centre, New Delhi 110067 (India); Bhoraskar, V.N. [Department of Physics, University of Pune, Pune 411007 (India); Dhole, S.D., E-mail: sanjay@physics.unipune.ac.in [Department of Physics, University of Pune, Pune 411007 (India)

    2014-07-15

    Highlights: •Study of silver ion induced defects and modifications in silica glass. •Variation in oxygen deficiency centres (ODA-II) and nonbridging oxygen hole centres (NBOHC). •Study of structural damage in terms of Urbach energy. -- Abstract: A few silica glass samples having 1 cm{sup 2} area and 0.1 cm thickness were irradiated with 100 MeV energy Ag{sup 7+} ions for the fluences ranging from 1 × 10{sup 12} ions/cm{sup 2} to 5 × 10{sup 13} ions/cm{sup 2}. The optical properties and the corresponding induced defects were characterised by the techniques such as UV–Visible, Photoluminescence (PL), Fourier transform infrared (FTIR), and Electron spin resonance (ESR) spectroscopy. The UV–Visible absorption spectra show two peaks, one at 5 eV and another weak peak at 5.8 eV. A peak observed at 5.0 eV corresponds to B{sub 2} band (oxygen deficiency in SiO{sub 2} network) and the peak at 5.8 eV is due to the paramagnetic defects like E′ centre. The intensities of these peaks found to be increased with increase in ion fluence. It attributes to the increase in the concentration of E′ centres and B{sub 2} band respectively. In addition, the optical band gap energy, Urbach energy and the defects concentration have been calculated using Urbach plot. The optical band gap found to be decreased from 4.65 eV to 4.39 eV and the Urbach energy found to be increased from 60 meV to 162 meV. The defect concentration of nonbridging oxygen hole centres (NBOHC) and E′ centres are found to be increased to 1.69 × 10{sup 13} cm{sup −3} and 3.134 × 10{sup 14} cm{sup −3} respectively. In PL spectra, the peak appeared at 1.92 eV and 2.7 eV envisage the defects of nonbridging oxygen hole centres and B{sub 2α} oxygen deficient centres respectively. ESR spectra also confirms the existence of E′ and NBOHC centres. FTIR spectra shows scissioning of Si-O-Si bonds and the formation of Si-H and Si-OH bonds, which supports to the co-existence of the defects induced by Ag

  12. Validation of the GEANT4 simulation of bremsstrahlung from thick targets below 3 MeV

    Energy Technology Data Exchange (ETDEWEB)

    Pandola, L., E-mail: pandola@lns.infn.it [INFN, Laboratori Nazionali del Sud, Via Santa Sofia 62, I-95125 Catania (Italy); INFN, Gran Sasso Science Institute, Viale Francesco Crispi 7, I-67100 L’Aquila (Italy); Andenna, C. [INAIL, Dipartimento Innovazioni Tecnologiche e Sicurezza degli Impianti, Prodotti ed Insediamenti Antropici, Via Alessandria 220, I-00198 Roma (Italy); Caccia, B. [Dipartimento Tecnologie e Salute, Istituto Superiore di Sanità and INFN, Gruppo Collegato dell’Istituto Superiore di Sanità, Viale Regina Elena 299, I-00161 Roma (Italy)

    2015-05-01

    The bremsstrahlung spectra produced by electrons impinging on thick targets are simulated using the GEANT4 Monte Carlo toolkit. Simulations are validated against experimental data available in literature for a range of energy between 0.5 and 2.8 MeV for Al and Fe targets and for a value of energy of 70 keV for Al, Ag, W and Pb targets. The energy spectra for the different configurations of emission angles, energies and targets are considered. Simulations are performed by using the three alternative sets of electromagnetic models that are available in GEANT4 to describe bremsstrahlung. At higher energies (0.5–2.8 MeV) of the impinging electrons on Al and Fe targets, GEANT4 is able to reproduce the spectral shapes and the integral photon emission in the forward direction. The agreement is within 10–30%, depending on energy, emission angle and target material. The physics model based on the Penelope Monte Carlo code is in slightly better agreement with the measured data than the other two. However, all models over-estimate the photon emission in the backward hemisphere. For the lower energy study (70 keV), which includes higher-Z targets, all models systematically under-estimate the total photon yield, providing agreement between 10% and 50%. The results of this work are of potential interest for medical physics applications, where knowledge of the energy spectra and angular distributions of photons is needed for accurate dose calculations with Monte Carlo and other fluence-based methods.

  13. MeV energy electron beam induced damage in isotactic polypropylene

    Energy Technology Data Exchange (ETDEWEB)

    Mathakari, N.L.; Bhoraskar, V.N. [Microtron Accelerator Laboratory, Department of Physics, University of Pune, Pune 411007 (India); Dhole, S.D. [Microtron Accelerator Laboratory, Department of Physics, University of Pune, Pune 411007 (India)], E-mail: sanjay@physics.unipune.ernet.in

    2008-06-15

    A few thin films of isotactic polypropylene were irradiated with 6 MeV energy electrons, in the fluence range from 5 x 10{sup 14} to 2 x 10{sup 15} electrons/cm{sup 2}. The structural, optical and mechanical properties were characterized by techniques such as FTIR, UV-vis, XRD, SEM, hardness and contact angle measurements. The FTIR spectra indicate that C-H and C-C bonds are scissioned and an isotactic arrangement of chains is partially destroyed. Moreover, the new carbonyl groups (C=O) are observed, which signifies oxidation. The UV-vis spectra shows a red shift in the absorption edge from pristine value of 240 to 380 nm, which corresponds to decrease in the optical band gap from 5.17 to 3.27 eV. This is because of the formation of conjugated double bonds as well as carbonization. The crystalline properties were analysed using XRD and it shows no profound change. This result may attribute that the radiation-induced changes have probably occurred to a large extent in amorphous regions. However, surface morphology by SEM and contact angle measurements showed considerable surface roughening, which indicates an uneven evolution of gases from the surface. Interestingly, the surface hardness of the films was found to increase with fluence and it may be due to crosslinking and carbonization on the surface. Overall, in conclusion this study shows considerable modifications in the physicochemical properties of isotactic polypropylene irradiated by 6 MeV energy pulsed electrons.

  14. Elastic scattering of the halo nucleus 6 He from 197 Au at Elab=27 MeV

    Directory of Open Access Journals (Sweden)

    O. R. Kakuee

    2003-12-01

    Full Text Available   A radioactive ion beam of 6He produced via the 7Li(p,2p6He reaction with typical intensity of 3 × 106 ions/see was elastically scattered from LiF(Au targets. Elastic scattering of 6He at Elab=27 MeV with 197Au have been measured in the angular range of 6º-72º in the laboratory system employing LEDA and LAMP detection system. Optical Model calculations have been used to fit the data .

  15. Measurement of the vector and tensor analyzing powers for dp-elastic scattering at 880 MeV

    Energy Technology Data Exchange (ETDEWEB)

    Kurilkin, P.K., E-mail: pkurilkin@jinr.ru [VBLHEP-JINR, 141980 Dubna, Moscow region (Russian Federation); Ladygin, V.P. [VBLHEP-JINR, 141980 Dubna, Moscow region (Russian Federation); Uesaka, T. [Center for Nuclear Study, University of Tokyo, Tokyo 113-0033 (Japan); Suda, K. [RIKEN Nishina Center, Wako, Saitama 351-0198 (Japan); Gurchin, Yu.V.; Isupov, A.Yu. [VBLHEP-JINR, 141980 Dubna, Moscow region (Russian Federation); Itoh, K. [Department of Physics, Saitama University, Saitama (Japan); Janek, M. [VBLHEP-JINR, 141980 Dubna, Moscow region (Russian Federation); Physics Department, University of Zilina, 010 26 Zilina (Slovakia); Karachuk, J.-T. [VBLHEP-JINR, 141980 Dubna, Moscow region (Russian Federation); Advanced Research Institute for Electrical Engineering, Bucharest (Romania); Kawabata, T. [Center for Nuclear Study, University of Tokyo, Tokyo 113-0033 (Japan); Khrenov, A.N.; Kiselev, A.S.; Kizka, V.A. [VBLHEP-JINR, 141980 Dubna, Moscow region (Russian Federation); Krasnov, V.A. [VBLHEP-JINR, 141980 Dubna, Moscow region (Russian Federation); Institute for Nuclear Research, Moscow (Russian Federation); Ladygina, N.B. [VBLHEP-JINR, 141980 Dubna, Moscow region (Russian Federation); Livanov, A.N. [VBLHEP-JINR, 141980 Dubna, Moscow region (Russian Federation); Institute for Nuclear Research, Moscow (Russian Federation); Maeda, Y. [Kyushi University, 6-10-1 Hakozaki, Higashi-ku, Fukuoka-shi 812 (Japan); Malakhov, A.I.; Piyadin, S.M.; Reznikov, S.G. [VBLHEP-JINR, 141980 Dubna, Moscow region (Russian Federation); and others

    2012-08-29

    The vector A{sub y} and tensor analyzing powers A{sub yy} and A{sub xx} for dp-elastic scattering were measured at T{sub d}{sup lab}=880 MeV over the c.m. angular range from 60 Degree-Sign to 140 Degree-Sign at the JINR Nuclotron. The data are compared with predictions of different theoretical models based on the use of nucleon-nucleon forces only. The observed discrepancies of the measured analyzing powers from the calculations require the consideration of additional mechanisms.

  16. Micro-Raman and UV-VIS Studies of 100 MeV Ni4+ Irradiated Cadmium Telluride Thin Films

    OpenAIRE

    Neelam Pahwa; A.D. Yadav; Dubey, S.K.; Patel, A. P.

    2011-01-01

    CdTe thin films grown by thermal evaporation on quartz substrates were irradiated with Swift (100 MeV) Ni 4 + ions for fluences in the range 1.0 × 1011 - 1.0 × 1013 cm – 2. The modification in the structure and optical properties has been studied as a function of ion fluence using Micro-Raman spectroscopy and UV-VIS spectroscopy. In Micro Raman spectrum, weak LO and TO modes of CdTe and A1 & E modes of Te were observed with blue shift which was found to increase with increase in fluence. Inte...

  17. 50 MeV lithium ion beam irradiation effects in poly vinylidene ...

    Indian Academy of Sciences (India)

    Home; Journals; Bulletin of Materials Science; Volume 23; Issue 6. 50 MeV lithium ion beam irradiation effects in poly vinylidene fluoride (PVDF) polymer ... Irradiation effects of 50 MeV 7Li+3 ion beam induced in bulk PVDF polymer have been studied with respect to their optical, chemical, structural and electrical behaviour ...

  18. CESAR, 2 MeV electron storage ring; general view.

    CERN Multimedia

    CERN PhotoLab

    1964-01-01

    CESAR (CERN Electron Storage and Accumulation Ring) was built as a study-model for the ISR (Intersecting Storage Rings). The model had to be small (24 m circumference) and yet the particles had to be highly relativistic, which led to the choice of electrons. On the other hand, in order to model the behaviour of protons, effects from synchrotron radiation had to be negligible, which meant low magnetic fields (130 G in the bending magnets) and a corresponding low energy of 1.75 MeV. All the stacking (accumulation) procedures envisaged for the ISR were proven with CESAR, and critical aspects of transverse stability were explored. Very importantly, CESAR was the test-bed for the ultrahigh vacuum techniques and components, essential for the ISR, with a final pressure of 6E-11 Torr. The CESAR project was decided early in 1960, design was completed in 1961 and construction in 1963. After an experimental period from 1964 to 1967, CESAR was dismantled in 1968.

  19. Multipurpose 5-MeV linear induction accelerator

    Energy Technology Data Exchange (ETDEWEB)

    Birx, D.L.; Hawkins, S.A.; Poor, S.E.; Reginato, L.L. Smith, M.W.

    1984-06-11

    Although linear induction accelerators (LIAs) are quite reliable by most standards, they are limited in repeating rate, average power, and reliability because the final stage of energy delivery is based on spark gap performance. In addition, they have a low duty factor of operation. To provide a higher burst rate and greater reliability, the researchers used new technology to develop a magnetic pulse compression scheme that eliminates all spark gaps and exceeds requirements. The paper describes the scheme. The magnetic drive system can be tailored to drive induction cells from a few kA to over 10 kA at 500 kV, with average beam power levels in the megawatts. This new 5-MeV, 2.5-kA LIA under construction at the Lawrence Livermore National Laboratory (LLNL) will be used for the development of high brightness sources and will provide a test bed for the new technology, which should lead to LIAs that surpass the radio frequency linacs for efficiency and reliability, as well as fit other industrial applications, such as sewage sterilization.

  20. CESAR, 2 MeV electron storage ring.

    CERN Multimedia

    CERN PhotoLab

    1967-01-01

    CESAR (CERN Electron Storage and Accumulation Ring) was built as a study-model for the ISR (Intersecting Storage Rings). The model had to be small (24 m circumference) and yet the particles had to be highly relativistic, which led to the choice of electrons. On the other hand, in order to model the behaviour of protons, effects from synchrotron radiation had to be negligible, which meant low magnetic fields (130 G in the bending magnets) and a corresponding low energy of 1.75 MeV. All the stacking (accumulation) procedures envisaged for the ISR were proven with CESAR, and critical aspects of transverse stability were explored. Very importantly, CESAR was the test-bed for the ultrahigh vacuum techniques and components, essential for the ISR, with a final pressure of 6E-11 Torr. The CESAR project was decided early in 1960, design was completed in 1961 and construction in 1963. After an experimental period from 1964 to 1967, CESAR was dismantled in 1968.

  1. Ultrafast laser driven micro-lens to focus and energy select MeV protons

    Energy Technology Data Exchange (ETDEWEB)

    Toncian, Toma

    2008-05-15

    A technique for simultaneous focusing and energy selection of high-current, MeV proton beams using radial, transient electric fields (10{sup 7}-10{sup 10} V/m) triggered on the inner wall of a hollow micro-cylinder by an intense, sub-picosecond laser-pulse is presented. Due to the transient nature of the radial focusing field, the proposed method allows selection of a desired range out of the spectrum of the poly-energetic proton beam. This technique addresses current drawbacks of laser-accelerated proton beams, i.e. their broad spectrum and divergence at the source. This thesis presents both experimental and computational studies that led to the understanding of the physical processes driving the micro-lens. After an one side irradiation of a hollow metallic cylinder a radial electric field develops inside the cylinder. Hot electrons generated by the interaction between laser pulse and cylinder wall spread inside the cylinder generating a plasma at the wall. This plasma expands into vacuum and sustains an electric field that acts as a collecting lens on a proton beam propagating axially through the cylinder. Both focusing and the reduction of the intrinsic beam divergence from 20 deg to.3 deg for a narrow spectral range was demonstrated. By sub-aperturing the beam a narrow spectral range ({delta}{epsilon}/{epsilon} < 3%) was selected from the poly-energetic beam. The micro-lens properties are tunable allowing for optimization towards applications. Optical probing techniques and proton imaging were employed to study the spacial and temporal evolution of the field and revealed a complex physical scenario of the rise and decay of the radial electric field. Each aspect studied experimentally is interpreted using 2D PIC and ray tracing simulations. A very good agreement between the experimental and computational data is found. The PIC simulations are used to upscale the demonstrated micro-lens capabilities to the focusing of a 270 MeV proton beam, an energy relevant

  2. High resolution {sup 12}C({gamma},p) experiments at E{sub {gamma}} {approx_equal} 25-75 MeV

    Energy Technology Data Exchange (ETDEWEB)

    Ruijter, H.

    1995-08-01

    Absolute differential cross sections for the {sup 12}C({gamma},p){sup 11}B reaction have been measured over proton detection angels ranging from 30 to 150 deg, using tagged photons of 25-75 MeV energy, for low-lying regions of residual excitation energy in {sup 11}B. Four experiments were performed at the MAX laboratory in Lund in order to provide data. Previously reported cross sections for the reaction had systematic uncertainties of a magnitude which made them agree, in spite of a large spread in absolute values. The cross sections reported, with a systematic uncertainty of 8%, remove previous ambiguities for E{sub {gamma}}=40-75 MeV. A reinterpretation of the states excited in{sup 11}B at E about 7 MeV is also presented. The data are compared with quasi-elastic (e,e`p) results in PWIA in the same recoil momentum range. It is found that the momentum distributions do not scale for the two reaction types. Furthermore, the data are compared with the results for the inverse reaction (p,{gamma}) in the centre-of-momentum system by detailed balance. The comparison with respect to missing momentum indicates an angular dependence in the ({gamma},p) reaction which is not present in the inverse (p,{gamma}) reaction. Recent results from the MAX laboratory for the ({gamma},n) reaction are compared to the ({gamma},p) results. The mirror nuclei {sup 11}C and {sup 11}B have almost identical excitation energy spectra at E{sub {gamma}}=60 MeV. It is concluded that HF-RPA calculations with essential contributions of meson exchange currents provide a qualitative description of the angular distributions obtained for the ({gamma},p) reaction. An extension of the spherical symmetric basis for the wave function is suggested for the states at E about 7 MeV in {sup 11}B. 108 refs, 83 figs.

  3. Neutron spectrometry and dosimetry in 100 and 300 MeV quasi-mono-energetic neutron field at RCNP, Osaka University, Japan

    Directory of Open Access Journals (Sweden)

    Mares Vladimir

    2017-01-01

    Full Text Available This paper describes the results of neutron spectrometry and dosimetry measurements using an extended range Bonner Sphere Spectrometer (ERBSS with 3He proportional counter performed in quasi-mono-energetic neutron fields at the ring cyclotron facility of the Research Center for Nuclear Physics (RCNP, Osaka University, Japan. Using 100 MeV and 296 MeV proton beams, neutron fields with nominal peak energies of 96 MeV and 293 MeV were generated via 7Li(p,n7Be reactions. Neutrons produced at 0° and 25° emission angles were extracted into the 100 m long time-of-flight (TOF tunnel, and the energy spectra were measured at a distance of 35 m from the target. To deduce the corresponding neutron spectra from thermal to the nominal maximum energy, the ERBSS data were unfolded using the MSANDB unfolding code. At high energies, the neutron spectra were also measured by means of the TOF method using NE213 organic liquid scintillators. The results are discussed in terms of ambient dose equivalent, H*(10, and compared with the readings of other instruments operated during the experiment.

  4. Tenfold enhancement of MeV Proton generation by a moderate ultra-short laser interaction with H2O nano-wire targets

    CERN Document Server

    Zigler, A; Bruner, N; Schleifer, E; Eisenmann, S; Henis, Z; Botton, M; Pikuz, S A; Faenov, A Y; Gordon, D; Sprangle, P

    2010-01-01

    Compact sources of high energy protons (50-500MeV) are expected to be key technology in a wide range of scientific applications. Particularly promising is the target normal sheath acceleration (TNSA) scheme, holding record level of 67MeV protons generated by a peta-Watt laser. In general, laser intensity exceeding 10^18 W/cm2 is required to produce MeV level protons. Enhancing the energy of generated protons using compact laser sources is very attractive task nowadays. Recently, nano-scale targets were used to accelerate ions. Here we report on the first generation of 5.5-7.5MeV protons by modest laser intensities (4.5 x 10^17 W/cm2) interacting with H2O nano-wires (snow) deposited on a Sapphire substrate. In this setup, the plasma near the tip of the nano-wire is subject to locally enhanced laser intensity with high spatial gradients, and confined charge separation is obtained. Electrostatic fields of extremely high intensities are produced, and protons are accelerated to MeV-level energies. Nano-wire engine...

  5. Suzaku Observations of Extreme MeV Blazar Swift J0746.3+2548

    Energy Technology Data Exchange (ETDEWEB)

    Watanabe, Shin; Sato, Rie; Takahashi, Tadayuki; Kataoka, Jun; Madejski, Greg; Sikora, Marek; Tavecchio, Fabrizio; Sambruna, Rita; Romani, Roger; Edwards, Philip G.; Pursimo, Tapio

    2008-12-01

    We report the Suzaku observations of the high luminosity blazar SWIFT J0746.3+2548 (J0746) conducted in November 2005. This object, with z = 2.979, is the highest redshift source observed in the Suzaku Guaranteed Time Observer (GTO) period, is likely to show high gamma-ray flux peaking in the MeV range. As a result of the good photon statistics and high signal-to-noise ratio spectrum, the Suzaku observation clearly confirms that J0746 has an extremely hard spectrum in the energy range of 0.3-24 keV, which is well represented by a single power-law with a photon index of {Lambda}{sub ph} {approx_equal} 1.17 and Galactic absorption. The multiwavelength spectral energy distribution of J0746 shows two continuum components, and is well modeled assuming that the high-energy spectral component results from Comptonization of the broad-line region photons. In this paper we search for the bulk Compton spectral features predicted to be produced in the soft X-ray band by scattering external optical/UV photons by cold electrons in a relativistic jet. We discuss and provide constraints on the pair content resulting from the apparent absence of such features.

  6. Measurement of multiple scattering of 13 and 20 MeV electrons by thin foils

    Science.gov (United States)

    Ross, C. K.; McEwen, M. R.; McDonald, A. F.; Cojocaru, C. D.; Faddegon, B. A.

    2008-01-01

    To model the transport of electrons through material requires knowledge of how the electrons lose energy and scatter. Theoretical models are used to describe electron energy loss and scatter and these models are supported by a limited amount of measured data. The purpose of this work was to obtain additional data that can be used to test models of electron scattering. Measurements were carried out using 13 and 20 MeV pencil beams of electrons produced by the National Research Council of Canada research accelerator. The electron fluence was measured at several angular positions from 0° to 9° for scattering foils of different thicknesses and with atomic numbers ranging from 4 to 79. The angle, θ1∕e, at which the fluence has decreased to 1∕e of its value on the central axis was used to characterize the distributions. Measured values of θ1∕e ranged from 1.5° to 8° with a typical uncertainty of about 1%. Distributions calculated using the EGSnrc Monte Carlo code were compared to the measured distributions. In general, the calculated distributions are narrower than the measured ones. Typically, the difference between the measured and calculated values of θ1∕e is about 1.5%, with the maximum difference being 4%. The measured and calculated distributions are related through a simple scaling of the angle, indicating that they have the same shape. No significant trends with atomic number were observed. PMID:18841865

  7. Nuclear halo of a 177\\,MeV proton beam in water

    CERN Document Server

    Gottschalk, Bernard; Daartz, Juliane; Wagner, Miles S

    2014-01-01

    The dose distribution of a pencil beam in a water tank consists of a core, a halo and an aura. The core consists of primary protons which suffer multiple Coulomb scattering (MCS) and slow down by multiple collisions with atomic electrons (Bethe-Bloch theory). The halo consists of charged secondaries, many of them protons, from elastic interactions with H, elastic and inelastic interactions with O, and nonelastic interactions with O. We show that the halo radius is roughly one third of the beam range. The aura consists of neutral secondaries (neutrons and gamma rays) and the charged particles they set in motion. We have measured the core/halo at 177 MeV using a test beam offset in a water tank. The beam monitor was a plane parallel ionization chamber (IC) and the field IC a dose calibrated Exradin T1. Our dose measurements are absolute. We took depth-dose scans at ten displacements from the beam axis ranging from 0 to 10 cm. The dose spans five orders of magnitude, and the transition from halo to aura is obvio...

  8. Depth distribution of carrier lifetime in 65 MeV oxygen ion irradiated silicon wafers

    Energy Technology Data Exchange (ETDEWEB)

    Shinde, N.S. [Ecotopia Science Institute, Division of Energy Science, Nagoya University, Nagoya (Japan); Dahiwale, S.S. [Department of Physics, University of Pune, Pune 411 007 (India); Kanjilal, D. [Nuclear Science Centre, New Delhi (India); Bhoraskar, V.N. [Department of Physics, University of Pune, Pune 411 007 (India); Dhole, S.D. [Department of Physics, University of Pune, Pune 411 007 (India)]. E-mail: sanjay@physics.unipune.ernet.in

    2006-03-15

    CZ-grown, n-doped crystalline Si(1 1 1) of resistivity 60 {omega} cm and 140 {omega} cm were irradiated with 65 MeV energy oxygen ions, in the fluence range of 2 x 10{sup 1}-10{sup 14} ions/cm{sup 2}. The depth and spatial profile of excess minority carrier recombination time {tau} (lifetime) was measured using photoconductive decay (PCD) method. Lifetime measurements were carried out before the stopping range of impinging ions. Results show a monotonous decrease in lifetime with fluence, which is attributed to defect creation mechanism by electronic energy loss based on the thermal spike model. Also, surface modification is expected with a small loss in crystalline quality. This surface is considered to be a multi-crystalline surface with large grain boundaries that act as trapping sites for excess holes in n-Si(1 1 1). Annealing of the irradiated samples showed a near complete recovery at 750 deg. C for a period of 1 h.

  9. Experimental evaluation of the response of micro-channel plate detector to ions with 10s of MeV energies

    Energy Technology Data Exchange (ETDEWEB)

    Jeong, Tae Won; Ter-Avetisyan, S. [Center for Relativistic Laser Science, Institute of Basic Science (IBS), Gwangju 61005 (Korea, Republic of); Department of Physics and Photon Science, Gwangju Institute of Science and Technology (GIST), Gwangju 61005 (Korea, Republic of); Singh, P. K.; Kakolee, K. F. [Center for Relativistic Laser Science, Institute of Basic Science (IBS), Gwangju 61005 (Korea, Republic of); Scullion, C.; Ahmed, H.; Hadjisolomou, P.; Alejo, A.; Kar, S.; Borghesi, M. [School of Mathematics and Physics, The Queen’s University of Belfast, Belfast BT7 1NN (United Kingdom)

    2016-08-15

    The absolute calibration of a microchannel plate (MCP) assembly using a Thomson spectrometer for laser-driven ion beams is described. In order to obtain the response of the whole detection system to the particles’ impact, a slotted solid state nuclear track detector (CR-39) was installed in front of the MCP to record the ions simultaneously on both detectors. The response of the MCP (counts/particles) was measured for 5–58 MeV carbon ions and for protons in the energy range 2–17.3 MeV. The response of the MCP detector is non-trivial when the stopping range of particles becomes larger than the thickness of the detector. Protons with energies E ≳ 10 MeV are energetic enough that they can pass through the MCP detector. Quantitative analysis of the pits formed in CR-39 and the signal generated in the MCP allowed to determine the MCP response to particles in this energy range. Moreover, a theoretical model allows to predict the response of MCP at even higher proton energies. This suggests that in this regime the MCP response is a slowly decreasing function of energy, consistently with the decrease of the deposited energy. These calibration data will enable particle spectra to be obtained in absolute terms over a broad energy range.

  10. Experimental evaluation of the response of micro-channel plate detector to ions with 10s of MeV energies

    Science.gov (United States)

    Jeong, Tae Won; Singh, P. K.; Scullion, C.; Ahmed, H.; Kakolee, K. F.; Hadjisolomou, P.; Alejo, A.; Kar, S.; Borghesi, M.; Ter-Avetisyan, S.

    2016-08-01

    The absolute calibration of a microchannel plate (MCP) assembly using a Thomson spectrometer for laser-driven ion beams is described. In order to obtain the response of the whole detection system to the particles' impact, a slotted solid state nuclear track detector (CR-39) was installed in front of the MCP to record the ions simultaneously on both detectors. The response of the MCP (counts/particles) was measured for 5-58 MeV carbon ions and for protons in the energy range 2-17.3 MeV. The response of the MCP detector is non-trivial when the stopping range of particles becomes larger than the thickness of the detector. Protons with energies E ≳ 10 MeV are energetic enough that they can pass through the MCP detector. Quantitative analysis of the pits formed in CR-39 and the signal generated in the MCP allowed to determine the MCP response to particles in this energy range. Moreover, a theoretical model allows to predict the response of MCP at even higher proton energies. This suggests that in this regime the MCP response is a slowly decreasing function of energy, consistently with the decrease of the deposited energy. These calibration data will enable particle spectra to be obtained in absolute terms over a broad energy range.

  11. Standard Test Method for Oxygen Content Using a 14-MeV Neutron Activation and Direct-Counting Technique

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2007-01-01

    1.1 This test method covers the measurement of oxygen concentration in almost any matrix by using a 14-MeV neutron activation and direct-counting technique. Essentially, the same system may be used to determine oxygen concentrations ranging from over 50 % to about 10 g/g, or less, depending on the sample size and available 14-MeV neutron fluence rates. Note 1 - The range of analysis may be extended by using higher neutron fluence rates, larger samples, and higher counting efficiency detectors. 1.2 This test method may be used on either solid or liquid samples, provided that they can be made to conform in size, shape, and macroscopic density during irradiation and counting to a standard sample of known oxygen content. Several variants of this method have been described in the technical literature. A monograph is available which provides a comprehensive description of the principles of activation analysis using a neutron generator (1). 1.3 The values stated in either SI or inch-pound units are to be regarded...

  12. Production cross-sections of residual radionuclides from proton-induced reactions on natAg up to 40 MeV

    Science.gov (United States)

    Khandaker, Mayeen Uddin; Kim, Kwangsoo; Kim, Kyung-Sook; Lee, Manwoo; Kim, Guinyun; Cho, Young Sik; Lee, Young Ouk

    2008-12-01

    We measured the cross-sections of the 104g,105,106mAg and 104,107Cd radionuclides produced by proton-induced reactions on natural silver by using a stacked-foil activation technique in the energy range from a threshold energy to 40 MeV at a MC50 cyclotron. The results showed generally good agreement with available data as well as the theoretical data. The integral yields for thick targets were also deduced using the measured cross-sections and the stopping power of natAg over the energy range from a threshold energy to 40 MeV, taking into account that the total energy is absorbed in the targets. The production cross-sections for the 104gAg and the 104Cd radionuclides from natural silver were measured for the first time.

  13. Fast neutrons from thick deuterium target irradiated by 15.8 MeV protons and 14.1 MeV deuterons

    CERN Document Server

    Bem, P; Cvachovec, F; Götz, M; Kroha, V; Nikolskii, E Y; Simeckova, E; Vincour, J

    1999-01-01

    The energy spectra of neutrons emitted by a thick deuterium target at 0 deg. angle, irradiated by a beam of 15.8 MeV protons and 14.1 MeV deuterons were measured in an open geometry with a stilbene scintillator and with a two-dimensional n-gamma discrimination technique. The evaluated spectral yields were compared with those of p+Be and d+Be reactions at relevant energies. This comparison shows that the D-target spectra are substantially harder having small relative contribution of low-energy neutrons, which makes these reactions useful as intense neutron sources for biomedical and analytical purposes. The total neutron yield from the d+D reaction is in good agreement with values calculated from published differential cross-section data. The p+D reaction seems to be the most effective fast neutron source, based on low-energy (E<40 MeV) cyclotrons.

  14. Measurements of (n,xp), (n,xd) double differential cross sections of Al and C for neutrons at 75 and 65 MeV

    Energy Technology Data Exchange (ETDEWEB)

    Nauchi, Yasushi; Baba, Mamoru; Iwasaki, Tomohiko [Tohoku Univ., Sendai (Japan). Faculty of Engineering] [and others

    1998-03-01

    The (n,xp) and (n,xd) double differential cross sections (DDXs) of Al and C were measured at 6 angles (12deg, 17deg, 25deg, 40deg, 55deg and 70deg) for neutrons En=65 and 75 MeV. These data are compared with theoretical calculations of ISOBAR and GNASH. A new wide range spectrometer under fabrication to down the detection threshold is also described. (author)

  15. Fusion of /sup 14/N+/sup 12/C at energies up to 178 MeV. [Cross sections, liquid-drop limit

    Energy Technology Data Exchange (ETDEWEB)

    Stokstad, R.G.; del Campo, J.G.; Biggerstaff, J.A.; Snell, A.H.; Stelson, P.H.

    1976-06-28

    The cross section for the fusion of /sup 14/N+/sup 12/C has been determined at bombarding energies covering the range E/sub 14//subN/=43--178 MeV (3 to 12 times the interaction barrier height). The cross section decreases slowly with increasing energy and, at the highest energy, suggests that /sup 26/Al has been formed with an angular momentum equal to the liquid-drop limit. (AIP)

  16. Study on strontium isotope abundance-ratio measurements by using a 13-MeV proton beam

    Science.gov (United States)

    Jeong, Cheol-Ki; Jang, Han; Lee, Goung-Jin

    2016-09-01

    The Rb-Sr dating method is used in dating Paleozoic and Precambrian rocks. This method measures the 87Rb and the 87Sr concentrations by using thermal ionization mass spectrometry (TIMS) [J. Hefne et al., Inter. J. Phys. Sci. 3(1), 28 (2008)]. In addition, it calculates the initial 87Sr/86Sr ratio to increase the reliability of Rb-Sr dating. In this study, the 87Sr/86Sr ratio was measured by using a 13-MeV proton accelerator. Proton kinetic energies are in the range of tens of megaelectronvolts, and protons have large absorption cross-sections for ( p, n) reactions with most substances. After absorbing a proton with such a high kinetic energy, an element is converted into a nuclide with its atomic number increased by one via nuclear transmutation. These nuclides usually have short half-lives and return to the original state through radioactive decay. When a strontium sample is irradiated with protons, nuclear transmutation occurs; thus, the strontium isotope present in the sample changes to a yttrium isotope, which is an activated radioisotope. Based on this, the 87Sr/86Sr ratio was calculated by analyzing the gamma-rays emitted by each yttrium isotope. The KIRAMS-13 cyclotron at the Cyclotron Center of Chosun University, where 13-MeV protons can be extracted, was utilized in our experiment. The 87Sr/86Sr isotope ratio was computed for samples irradiated with these protons, and the result was similar to the isotope ratio for the Standard Reference Material, i.e., 98.2 ± 3.4%. As part of the analysis, proton activation analyses were performed using 13-MeV protons, and the experimental results of this research suggest a possible approach for measuring the strontium-isotope abundance ratio of samples.

  17. Deuteron Photodisintegration between Egamma=2.4 MeV and 4.0 MeV

    Science.gov (United States)

    Czakon, Nicole; Tornow, Werner

    2002-10-01

    Deuteron Photodisintegration between Eγ=2.4 and 4.0 MeV W.Tornow, N.G. Czakon, C.R. Howell, A. Hutcheson, J.H. Kelley, V.N. Litvinenko, S. Mikhailov, I.V. Pinayev, and G.J. Weisel The p(n,γ)d reaction has no published data in the relevant big-bang nucleosynthesis (BBN) energy region. Theoretical calculations, such as the ones by Arenhoevel and Sanzone [1], contribute significant uncertainties in the relative abundances of elements produced BBN. This experiment was motivated by the varying theoretical calculations and the lack of experimental data. We measured the analyzing power for the ^2H(γ,n)p reaction at 90^o for eight different energies. A mono-energetic, linearly polarized g-ray beam was incident on a deuterated liquid scintillator (C_6D_12). The scattered neutrons were detected two detectors, mounted at θ = 90^o in the plane of the g-ray polarization, and two detectors, mounted at θ = 90^o in the plane perpendicular to the γ-ray polarization plane. The neutron time of flight and the proton energy were recorded in the deuterated scintillator. Monte-Carlo calculations have been performed to simulate finite-geometry and multiple scattering on Arenhövel's calculations [3]. Our data for the proton analyzing power will be compared to Rupak's predictions [2]. References 1. H. Arenhövel and M. Sanzone, Photodisintegration of the Deuteron: A Review of Theory and Experiment (Springer Verlag, 1991). 2. G. Rupak, Nucl. Phys. A678, 405 (2000). 3. H. Arenhövel, Private communication (2001).

  18. Experimental and Calculated Effectiveness of a Radiochromic Dye Film to Stopping 21 MeV 7Li- and 64 MeV 16O Ions

    DEFF Research Database (Denmark)

    Olsen, Kjeld J; Hansen, Johnny

    1984-01-01

    Relative radiation effectiveness, RE, of 21 MeV 7Li and 64 MeV 16O ions being completely stopped in a tissue equivalent film dose meter has been measured as a function of penetration depth and energy, and the results have been compared with calculations based on a δ-ray theory for heavy charged...... in the detector, which are important parameters in the theoretical model, does not improve the overall correlation between theory and experiment. It is concluded that disagreement between theoretical and experimental RE-values below 1.5 MeV/amu is partly due to lack of equivalence between the δ-ray spectrum...

  19. Beam diagnostics measurements at 3 MeV of the LINAC4 H- beam at CERN

    CERN Document Server

    Zocca, F; Duraffourg, M; Focker, G J; Gerard, D; Kolad, B; Lenardon, F; Ludwig, M; Raich, U; Roncarolo, F; Sordet, M; Tan, J; Tassan-Viol, J; Vuitton, C; Feshenko, A

    2014-01-01

    As part of the CERN LHC injector chain upgrade, LINAC4 [1, 2] will accelerate H- ions to 160 MeV, replacing the old 50 MeV proton linac. The ion source, the Low Energy Beam Transfer (LEBT) line, the 3 MeV Radio Frequency Quadrupole and the Medium Energy Beam Transfer (MEBT) line hosting a chopper, have been commissioned in the LINAC4 tunnel. Diagnostic devices are installed in the LEBT and MEBT line and in a movable diagnostics test bench which is temporarily added to the MEBT exit. The paper gives an overview of all the instruments used, including beam current transformers, beam position monitors, wire scanners and wire grids for transverse profile measurements, a longitudinal bunch shape monitor and a slit-and-grid emittance meter. The instrumentation performance is discussed and the measurement results that allowed characterizing the 3 MeV beam in the LINAC4 tunnel are summarized.

  20. Test Results of the PEFP 3MeV RFQ Upgrade

    CERN Document Server

    Cho, Yong-Sub; Jang, Ji-Ho; Kim, Han-Sung; Kim, Yong-Hwan; Kwon, Hyeok-Jung; Park, Mi-Young; Tae Seol, Kyung

    2005-01-01

    A 3MeV RFQ upgrade for 100MeV proton accelerator has been fabricated at PEFP (Proton Engineering Frontier Project). The tuning of the cavity was carried out before and after the brazing to meet the condition that the quadrupole field profile is within 1% of design value and dipole component is less than 1% of quadrupole one. The ancillary system such as high power RF including klystron power supply and cooling system were already tested up to operating level. Therefore, the main issues of the tests were cavity conditioning up to full power level and low duty beam test. After the completion of the beam test of RFQ itself, the 20MeV DTL which has been tested independently will be carried out. In this paper, the test results of the PEFP 3MeV RFQ upgrade including high power conditioning and low duty beam acceleration are presented.

  1. Atmospheric gamma-ray lines at low latitudes in the energy range : 0.3-8 MeV

    Science.gov (United States)

    Azcarate, I. N.

    2003-12-01

    An experiment carried out with a collimated gamma-ray detector is described. The detector system was transported by an stratospheric balloon, that was launched from Parana, Provincia de Entre Rios, Argentina, on 18 November 1992 ( geomagnetic cut-off 11.1 GV). The presence of a peak was observed, as a characteristic feature of the energy-loss spectrum in the detector. That peak corresponds to the 511 keV line produced by positron annihilation in both the atmopsphere and the lead collimator. The contribution to the counting rate ``below" the peak due to the 511 keV photons produced in the lead is computed. The resulting flux for the atmospheric 511 keV line, at an atmospheric depth of 4.5 g.cm-2, is (9 ± 0.07) x 10-2 phot. cm-2.s-1, which is compatible with measurements performed at other geomagnetic latitudes. Upper limits for other atmospheric gamma-ray lines fluxes are obtained. Acknowledgements : This research was partially supported by grant PIP 0430/98 from CONICET, from Argentina. I.N. Azcarate is a member of the Carrera del Investigador Cientifico y Tecnologico from CONICET, Argentina.

  2. Accurate transport simulation of electron tracks in the energy range 1 keV-4 MeV

    Energy Technology Data Exchange (ETDEWEB)

    Cobut, V. E-mail: vincent.cobut@chim.u-cergy.fr; Cirioni, L.; Patau, J.P

    2004-01-01

    Multipurpose electron transport simulation codes are widely used in the fields of radiation protection and dosimetry. Broadly based on multiple scattering theories and continuous energy loss stopping powers with some mechanism taking straggling into account, they give reliable answers to many problems. However they may be unsuitable in some specific situations. In fact, many of them are not able to accurately describe particle transport through very thin slabs and/or in high atomic number materials, or also when knowledge of high-resolution depth dose distributions is required. To circumvent these deficiencies, we developed a Monte Carlo code simulating each interaction along electron tracks. Gas phase elastic cross sections are corrected to take into account solid state effects. Inelastic interactions are described within the framework of the Martinez et al. [J. Appl. Phys. 67 (1990) 2955] theory intended to deal with energy deposition in both condensed insulators and conductors. The model described in this paper is validated for some materials as aluminium and silicon, encountered in spectrometric and dosimetric devices. Comparisons with experimental, theoretical and other simulation results are made for angular distributions and energy spectra of transmitted electrons through slabs of different thicknesses and for depth energy distributions in semi-infinite media. These comparisons are quite satisfactory.

  3. Measurement of the elastic cross section for positive pions on carbon at 142 MeV

    Energy Technology Data Exchange (ETDEWEB)

    Oyer, A.T.

    1976-12-01

    A measurement of the elastic cross section dsigma/d..cap omega.. was made for the reaction ..pi../sup +/ + /sup 12/C ..-->.. ..pi../sup +/ + /sup 12/C with 142 MeV pions at ten angles ranging from 35 to 85/sup 0/ in the laboratory. This experiment was done at the Los Alamos Meson Physics Facility. A double focusing magnetic spectrometer observed a cylindrical styrofoam target. The resulting momentum spectra were recorded by an array of nineteen totally depleted surface barrier detectors located at the spectrometer's focal plane. The spectra from the styrofoam were composed of peaks representing proton elastic, carbon elastic, carbon inelastic, and carbon quasi-elastic channels. A function made of Gaussians representing the two body channels and a distribution representing the quasi-elastic channel was fit to the data using a nonlinear least squares algorithm. The ratio of the carbon elastic to proton elastic cross sections was calculated from the areas of the corresponding Gaussians and then multiplied by the proton elastic cross section of Bugg et al eliminating several sources of systematic errors such as beam normalization. The differential cross sections were found to have the usual diffraction structure with a forward peak and a minimum near 55/sup 0/. Finally, the carbon elastic cross sections were compared to similar ..pi../sup -/ + /sup 12/C cross sections of Binon et al using the optical model.

  4. Characteristics of a normoxic polymethacrylic acid gel dosimeter for a 72-MeV proton beam

    Energy Technology Data Exchange (ETDEWEB)

    Bong, Jihye [Department of Medical Physics, Kyonggi University, Suwon 443-760 (Korea, Republic of); Shin, Dongho [Proton Therapy Center, National Cancer Center, Goyang 410-769 (Korea, Republic of); Kwon, Soo-Il, E-mail: sikwon@kyonggi.ac.kr [Department of Medical Physics, Kyonggi University, Suwon 443-760 (Korea, Republic of)

    2014-01-21

    The characteristics of a normoxic polymethacrylic acid gel dosimeter for a 72-MeV proton beam were evaluated. A polymer gel dosimeter was synthesized using gelatin, methacrylic acid, hydroquinone, tetrakis(hydroxymethyl) phosphonium chloride, and highly purified distilled water. The dosimeter was manufactured by placement in a polyethylene (PE) container. Irradiated dosimeters were analyzed to determine the transverse relaxation time (T2) using a 1.5-T MRI. A calibration curve was obtained as a function of the absorbed dose. A Bragg curve made by irradiating the gel with mono-energy was compared with the results for a parallel plate ionization chamber. The spread-out Bragg peak (SOBP) range and distal dose fall-off (DDF) were comparatively analyzed by comparing the irradiated gel with a spread-out Bragg peak against with the ion chamber. Lastly, the gel's usefulness as a dosimeter for therapeutic radiation quality assurance was evaluated by obtaining its practical field size, flatness, and symmetry, through comparison of the profiles of the gel and ion chamber.

  5. Variance reduction techniques for 14 MeV neutron streaming problem in rectangular annular bent duct

    Energy Technology Data Exchange (ETDEWEB)

    Ueki, Kotaro [Ship Research Inst., Mitaka, Tokyo (Japan)

    1998-03-01

    Monte Carlo method is the powerful technique for solving wide range of radiation transport problems. Its features are that it can solve the Boltzmann`s transport equation almost without approximation, and that the complexity of the systems to be treated rarely becomes a problem. However, the Monte Carlo calculation is always accompanied by statistical errors called variance. In shielding calculation, standard deviation or fractional standard deviation (FSD) is used frequently. The expression of the FSD is shown. Radiation shielding problems are roughly divided into transmission through deep layer and streaming problem. In the streaming problem, the large difference in the weight depending on the history of particles makes the FSD of Monte Carlo calculation worse. The streaming experiment in the 14 MeV neutron rectangular annular bent duct, which is the typical streaming bench mark experiment carried out of the OKTAVIAN of Osaka University, was analyzed by MCNP 4B, and the reduction of variance or FSD was attempted. The experimental system is shown. The analysis model by MCNP 4B, the input data and the results of analysis are reported, and the comparison with the experimental results was examined. (K.I.)

  6. Nuclear halo of a 177 MeV proton beam in water: theory, measurement and parameterization

    CERN Document Server

    Gottschalk, Bernard; Daartz, Juliane; Wagner, Miles S

    2014-01-01

    The dose distribution of a monoenergetic pencil beam in water consists of an electromagnetic "core", a "halo" from charged nuclear secondaries, and a much larger "aura" from neutral secondaries. These regions overlap, but each has distinct spatial characteristics. We have measured the core/halo using a 177MeV test beam offset in a water tank. The beam monitor was a fluence calibrated plane parallel ionization chamber (IC) and the field chamber, a dose calibrated Exradin T1, so the dose measurements are absolute (MeV/g/p). We performed depth-dose scans at ten displacements from the beam axis ranging from 0 to 10cm. The dose spans five orders of magnitude, and the transition from halo to aura is clearly visible. We have performed model-dependent (MD) and model-independent (MI) fits to the data. The MD fit separates the dose into core, elastic/inelastic nuclear, nonelastic nuclear and aura terms, and achieves a global rms measurement/fit ratio of 15%. The MI fit uses cubic splines and the same ratio is 9%. We re...

  7. High repetition rate laser-driven MeV ion acceleration at variable background pressures

    Science.gov (United States)

    Snyder, Joseph; Ngirmang, Gregory; Orban, Chris; Feister, Scott; Morrison, John; Frische, Kyle; Chowdhury, Enam; Roquemore, W. M.

    2017-10-01

    Ultra-intense laser-plasma interactions (LPI) can produce highly energetic photons, electrons, and ions with numerous potential real-world applications. Many of these applications will require repeatable, high repetition targets that are suitable for LPI experiments. Liquid targets can meet many of these needs, but they typically require higher chamber pressure than is used for many low repetition rate experiments. The effect of background pressure on the LPI has not been thoroughly studied. With this in mind, the Extreme Light group at the Air Force Research Lab has carried out MeV ion and electron acceleration experiments at kHz repetition rate with background pressures ranging from 30 mTorr to >1 Torr using a submicron ethylene glycol liquid sheet target. We present these results and provide two-dimensional particle-in-cell simulation results that offer insight on the thresholds for the efficient acceleration of electrons and ions. This research is supported by the Air Force Office of Scientific Research under LRIR Project 17RQCOR504 under the management of Dr. Riq Parra and Dr. Jean-Luc Cambier. Support was also provided by the DOD HPCMP Internship Program.

  8. Absolute Calibration of Image Plate for electrons at energy between 100 keV and 4 MeV

    Energy Technology Data Exchange (ETDEWEB)

    Chen, H; Back, N L; Eder, D C; Ping, Y; Song, P M; Throop, A

    2007-12-10

    The authors measured the absolute response of image plate (Fuji BAS SR2040) for electrons at energies between 100 keV to 4 MeV using an electron spectrometer. The electron source was produced from a short pulse laser irradiated on the solid density targets. This paper presents the calibration results of image plate Photon Stimulated Luminescence PSL per electrons at this energy range. The Monte Carlo radiation transport code MCNPX results are also presented for three representative incident angles onto the image plates and corresponding electron energies depositions at these angles. These provide a complete set of tools that allows extraction of the absolute calibration to other spectrometer setting at this electron energy range.

  9. Spectral and temporal properties of long GRBs detected by INTEGRAL from 3 keV to 8 MeV

    DEFF Research Database (Denmark)

    Martin-Carrillo, A.; Topinka, M.; Hanlon, L.

    2010-01-01

    study of the spectral and temporal evolution of a subset of 7 INTEGRAL g – ray bursts across a wide energy range from 3 keV to 8MeV has been carried out. This GRB sample is characterised by long multi-peaked bursts that are bright in the JEM-X energy range and encompass X-ray rich bursts, X-ray flashes...... and classical GRBs. We report the detection of X-ray prompt and afterglow emission from GRB 041219A and GRB081003A with JEM-X for the first time. At least two temporal breaks have been identified in the X-ray afterglow light curve of GRB 081003A. These results demonstrate INTEGRAL’s broadband capabilities...

  10. Experimental and simulated d p breakup reaction data at 300, 400 and 500 MeV

    Directory of Open Access Journals (Sweden)

    Janek M.

    2014-01-01

    Full Text Available d p breakup reaction occupies large phase space. Two and three nucleon forces and relativistic effects can be investigated under various detector configuration. The results of simulation of d p breakup reaction in energy region from 300 to 500 MeV are presented. Preliminary results obtained at 300, 400 and 500 MeV of deuteron energy at some detector configurations at Nuclotron as well as future plans in investigation of relativistic effects are discussed.

  11. Coulomb dissociation of {sup 8}B at 254 A MeV

    Energy Technology Data Exchange (ETDEWEB)

    Suemmerer, K.; Boue, F.; Baumann, T.; Geissel, H.; Hellstroem, M.; Koczon, P.; Schwab, E.; Schwab, W.; Senger, P.; Surowiecz, A. [Gesellschaft fuer Schwerionenforschung (GSI), Darmstadt (Germany); Iwasa, N.; Ozawa, A. [Gesellschaft fuer Schwerionenforschung (GSI), Darmstadt (Germany)]|[RIKEN Institute of Physical and Chemical Research, Saitama (Japan); Surowka, G. [Gesellschaft fuer Schwerionenforschung (GSI), Darmstadt (Germany)]|[Jagiellonian Univ., Krakow (Poland). Inst. of Physics; Blank, B.; Czajkowski, S.; Marchand, C.; Pravikoff, M.S. [Centre d`Etudes Nucleaires de Bordeaux-Gradignan, 33 (France); Foerster, A.; Lauer, F.; Oeschler, H.; Speer, J.; Sturm, C.; Uhlig, F.; Wagner, A. [Technische Univ. Darmstadt (Germany); Gai, M. [Connecticut Univ., Storrs, CT (United States). Dept. of Physics; Grosse, E. [Inst. fuer Kern- und Hadronenphysik, Forschungszentrum Rossendorf, Dresden (Germany); Kohlmeyer, B. [Philipps Univ., Marburg (Germany). Fachbereich Physik; Kulessa, R.; Walus, W. [Jagiellonian Univ., Krakow (Poland). Inst. of Physics; Motobayashi, T. [Rikkyo Univ., Tokyo (Japan). Dept. of Physics; Teranishi, T. [RIKEN Institute of Physical and Chemical Research, Saitama (Japan)

    1998-06-01

    As an alternative method for determining the astrophysical S-factor for the {sup 7}Be(p,{gamma}){sup 8}B reaction we have measured the Coulomb dissociation of {sup 8}B at 254 A MeV. From our preliminary results, we obtain good agreement with both the accepted direct-reaction measurements and the low-energy Coulomb dissociation study of Iwasa et al. performed at about 50 A MeV. (orig.)

  12. High energy resolution characteristics on 14MeV neutron spectrometer for fusion experimental reactor

    Energy Technology Data Exchange (ETDEWEB)

    Iguchi, Tetsuo [Tokyo Univ., Tokai, Ibaraki (Japan). Nuclear Engineering Research Lab.; Takada, Eiji; Nakazawa, Masaharu

    1996-10-01

    A 14MeV neutron spectrometer suitable for an ITER-like fusion experimental reactor is now under development on the basis of a recoil proton counter telescope principle in oblique scattering geometry. To verify its high energy resolution characteristics, preliminary experiments are made for a prototypical detector system. The comparison results show reasonably good agreement and demonstrate the possibility of energy resolution of 2.5% in full width at half maximum for 14MeV neutron spectrometry. (author)

  13. Measurement of cross sections producing short-lived nuclei by 14 MeV neutron. Br, Te, Dy, Ho, Yb

    Energy Technology Data Exchange (ETDEWEB)

    Sakane, H.; Matsumoto, T.; Yamamoto, H.; Kawade, K. [Nagoya Univ. (Japan); Iida, T.; Takahashi, A.

    1997-03-01

    Nine neutron activation cross sections producing the nuclei with half-lives between 2 min and 57 min have been measured at energy range between 13.4 and 14.9 MeV for Br, Te, Dy, Ho, Yb. The cross sections of {sup 81}Br(n,p){sup 81m}Se, {sup 128}Te(n,p){sup 128m}Sb, {sup 128}Te(n,{alpha}){sup 125m}Sn, {sup 164}Dy(n,p){sup 164}Tb, {sup 165}Ho(n,{alpha}){sup 162}Tb, {sup 176}Yb(n,p){sup 176}Tm were newly obtained at the six energy points between 13.4-14.9 MeV, although the previous results have been obtained at one energy point. {sup 79}Br(n,2n){sup 78}Br, {sup 164}Dy(n,p){sup 164}Tb are compared with evaluated data of JENDL-3.2. The evaluations for these reactions agree reasonably well with experimental results. The cross sections of (n,p) reaction are compared with systematics by Kasugai et. al. The systematics agrees with experimental results. (author)

  14. Activation cross-sections of deuteron-induced nuclear reactions on natural iron up to 24 MeV

    Energy Technology Data Exchange (ETDEWEB)

    Khandaker, Mayeen Uddin, E-mail: mu_khandaker@yahoo.com [Department of Physics, University of Malaya, 50603 Kuala Lumpur (Malaysia); Haba, Hiromitsu; Kanaya, Jumpei [Nishina Center for Accelerator-Based Science, RIKEN, Wako, Saitama 351-0198 (Japan); Otuka, Naohiko [Nuclear Data Section, Division of Physical and Chemical Sciences, Department of Nuclear Sciences and Applications, International Atomic Energy Agency, A-1400 Vienna (Austria)

    2013-12-01

    Activation cross-sections of the {sup nat}Fe(d,x){sup 55,56,57,58g+m}Co, {sup 52g,54,56}Mn, {sup 51}Cr, {sup 59}Fe reactions were measured from their respective thresholds to 24 MeV via a stacked foil activation technique combined with HPGe γ-ray spectrometry. An overall good agreement is found with some of the earlier measurements, whereas partial agreements are obtained with the theoretical data extracted from the TENDL-2011 library. The present measurement reports four cross-sections of {sup 58g+m}Co, {sup 56}Mn and {sup 59}Fe radionuclides in the energy range of 20–24 MeV for the first time. Physical thick target yields deduced from the measured cross-sections are compared with the directly measured yields available in the literature. The measured {sup 58}Fe(d,p){sup 59}Fe cross section is underestimated by the original TENDL-2011 library while overestimated by the TENDL-2011 library renormalized by Ignatyuk for the FENDL-3 library.

  15. Depletion voltage studies on n-in-n MCz silicon diodes after irradiation with 70 MeV protons

    CERN Document Server

    Holmkvist, William

    2014-01-01

    Silicon detectors is the main component in the pixel detectors in the ATLAS experiment at CERN in order to detect the particles and recreate their tracks after a proton-proton collision. One criteria on these detectors is to be able to operate in the high radiation field close to the particle collision. The usual behavior of the silicon detectors is that they get type inverted and an increase in the depletion voltage can be seen after exposed to significant amounts of radiation. In contrast n-type Magnetic Czochralski (MCz) silicon doesn’t follow FZ silicons pattern of getting type inverted when it comes to high energy particle irradiation, in the range of GeV. However it was observed that MCz silicon diodes that had been irradiated with 23 MeV protons followed the FZ silicon behavior and did type invert. The aim of the project is to find out how the depletion voltage of MCz silicon changes after being irradiated by 70 MeV at fluencies of 1E13, 1E14 and 5E14 neq/cm2, to give a further insight of at what en...

  16. Effect of the energy of recoil atoms on conductivity compensation in moderately doped n-Si and n-SiC under irradiation with MeV electrons and protons

    Energy Technology Data Exchange (ETDEWEB)

    Kozlovski, V.V. [St. Petersburg State Polytechnic University, St. Petersburg 195251 (Russian Federation); Lebedev, A.A., E-mail: shura.lebe@mail.ioffe.ru [Ioffe Physical Technical Institute, Russian Academy of Sciences, St. Petersburg 194021 (Russian Federation); National Research University of Information Technologies, Mechanics, and Optics, St. Petersburg 197101 (Russian Federation); Emtsev, V.V.; Oganesyan, G.A. [Ioffe Physical Technical Institute, Russian Academy of Sciences, St. Petersburg 194021 (Russian Federation)

    2016-10-01

    Processes of radiation defect formation and conductivity compensation in silicon and silicon carbide irradiated with 0.9 MeV electrons are considered in comparison with the electron irradiation at higher energies. The experimental values of the carrier removal rate at the electron energy of 0.9 MeV are nearly an order of magnitude smaller than the similar values of the parameter for higher energy electrons (6–9 MeV). At the same time, the formation cross-section of primary radiation defects (Frenkel pairs, FPs) is nearly energy-independent in this range. It is assumed that these differences are due to the influence exerted by the energy of primary knocked-on atoms (PKAs). As the PKA energy increases, the average distance between the genetically related FPs grows and, as a consequence, the fraction of FPs unrecombined under irradiation becomes larger. The FP recombination radius is estimated (∼1.1 nm), which makes it possible to ascertain the charge state of the recombining components. Second, the increase in the PKA energy enables formation of new, more complex secondary radiation defects. At electron energies exceeding 15 MeV, the average PKA energies are closer to the values obtained under irradiation with 1 MeV protons, compared with an electron irradiation at the same energy. As for the radiation-induced defect formation, the irradiation of silicon with MeV protons can be, in principle, regarded as a superposition of the irradiation with 1 MeV electrons and that with silicon ions having energy of ∼1 keV, with the “source” of silicon ions generating these ions uniformly across the sample thickness.

  17. Effect of the energy of recoil atoms on conductivity compensation in moderately doped n-Si and n-SiC under irradiation with MeV electrons and protons

    Science.gov (United States)

    Kozlovski, V. V.; Lebedev, A. A.; Emtsev, V. V.; Oganesyan, G. A.

    2016-10-01

    Processes of radiation defect formation and conductivity compensation in silicon and silicon carbide irradiated with 0.9 MeV electrons are considered in comparison with the electron irradiation at higher energies. The experimental values of the carrier removal rate at the electron energy of 0.9 MeV are nearly an order of magnitude smaller than the similar values of the parameter for higher energy electrons (6-9 MeV). At the same time, the formation cross-section of primary radiation defects (Frenkel pairs, FPs) is nearly energy-independent in this range. It is assumed that these differences are due to the influence exerted by the energy of primary knocked-on atoms (PKAs). As the PKA energy increases, the average distance between the genetically related FPs grows and, as a consequence, the fraction of FPs unrecombined under irradiation becomes larger. The FP recombination radius is estimated (∼1.1 nm), which makes it possible to ascertain the charge state of the recombining components. Second, the increase in the PKA energy enables formation of new, more complex secondary radiation defects. At electron energies exceeding 15 MeV, the average PKA energies are closer to the values obtained under irradiation with 1 MeV protons, compared with an electron irradiation at the same energy. As for the radiation-induced defect formation, the irradiation of silicon with MeV protons can be, in principle, regarded as a superposition of the irradiation with 1 MeV electrons and that with silicon ions having energy of ∼1 keV, with the ;source; of silicon ions generating these ions uniformly across the sample thickness.

  18. Measurement of spin-correlation parameters A sub L L and A sub S L in p - p elastic scattering from 500 to 800 MeV

    Energy Technology Data Exchange (ETDEWEB)

    Glass, G.; Bhatia, T.S.; Hiebert, J.C.; Kenefick, R.A.; Nath, S.; Northcliffe, L.C.; Tippens, W.B. (Texas A M University, College Station, Texas 77843 (United States)); Barlow, D.B. (Northwestern University, Evanston, Illinois 60201 (United States)); Jarmer, J.J.; Simmons, J.E. (Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States)); Jeppesen, R.H. (University of Montana, Missoula, Montana 59812 (United States)); Tripard, G.E. (Washington State University, Pullman, Washington 99164 (United States))

    1992-01-01

    The spin-correlation observable {ital A}{sub {ital L}{ital L}} for {ital p}-{ital p} elastic scattering has been measured at energies 589, 640, 692, 743, and 793 MeV, over a c.m. angular range between 20{degree} and 100{degree}. The spin observable {ital A}{sub {ital S}{ital L}} was also measured in this angular range at energies 640 and 793 MeV. At 488 MeV both the spin observables were measured, but only near the c.m. angle of 90{degree}. The data are compared with the predictions of several phase-shift analyses and previous measurements. The energy dependence of {ital A}{sub {ital L}{ital L}} for the c.m. angle of 90{degree} is also presented and shows no anomalous behavior. These data provide better angular coverage over five of the energies, with comparable or better statistical precision, than previous measurements of {ital A}{sub {ital L}{ital L}}.

  19. New evaluations of n + Cu and n + Zr cross-section data for neutron energies up to 200 MeV

    Science.gov (United States)

    Pereslavtsev, P.; Leal, L.; Konobeyev, A.; Fischer, U.

    2017-09-01

    This work presents evaluated general purpose nuclear data files for the n+ 63,65Cu and n+ 90,91,92,94,96Zr reactions for neutron energies up to 200 MeV. The TALYS-1.8 code was used for the nuclear model simulations in the energy range from 1 keV to 200 MeV. To improve the pre-equilibrium particle emission the Geometry-Dependent Hybrid model (GDH) was used as option implemented in an extended version of the code as option. Resonance data based on recent measurements and their covariances were included in the files. A set of covariance data for all nuclear reactions was also prepared and included in the evaluations. The adjustments of the nuclear model parameters were performed to fit both available differential and integral measured data. The evaluated data were carefully checked against the latest fusion relevant integral measurements.

  20. Experimental Neutron-Induced Fission Fragment Mass Yields of 232Th and 238U at Energies from 10 to 33 MeV

    CERN Document Server

    Simutkin, V D; Blomgren, J; Österlund, M; Bevilacqua, R; Ryzhov, I V; Tutin, G A; Yavshits, S G; Vaishnene, L A; Onegin, M S; Meulders, J P; Prieels, R

    2013-01-01

    Development of nuclear energy applications requires data for neutron-induced reactions for actinides in a wide neutron energy range. Here we describe measurements of pre-neutron emission fission fragment mass yields of 232Th and 238U at incident neutron energies from 10 to 33 MeV. The measurements were done at the quasi-monoenergetic neutron beam of the Louvain-la-Neuve cyclotron facility CYCLONE; a multi-section twin Frisch-gridded ionization chamber was used to detect fission fragments. For the peak neutron energies at 33, 45 and 60 MeV, the details of the data analysis and the experimental results have been published before and in this work we present data analysis in the low-energy tail of the neutron energy spectra. The preliminary measurement results are compared with available experimental data and theoretical predictions.

  1. Cross sections of deuteron induced reactions on {sup nat}Cr up to 50 MeV: Experiments and comparison with theoretical codes

    Energy Technology Data Exchange (ETDEWEB)

    Hermanne, A., E-mail: aherman@vub.ac.be [Cyclotron Laboratory, Vrije Universiteit Brussel, Brussel 1090 (Belgium); Adam Rebeles, R. [Cyclotron Laboratory, Vrije Universiteit Brussel, Brussel 1090 (Belgium); Tarkanyi, F.; Takacs, S. [Institute of Nuclear Research, Hungarian Academy of Science, 4026 Debrecen (Hungary); Takacs, M. [Institute of Physics, University of Debrecen, 4026 Debrecen (Hungary); Ignatyuk, A. [Institute of Physics and Power Engineering, Obninsk 246020 (Russian Federation)

    2011-11-01

    Activation of Cr-containing components around high energy deuteron accelerator can pose radioprotection problems for maintenance personnel. In a stacked foil irradiation, followed by high resolution gamma spectroscopy the cross sections for production of {sup 46,47,48}Sc, {sup 51}Cr, {sup 52,54}Mn and {sup 48}V were measured up to 50 MeV resulting in first systematic assessment above 15 MeV. Reduced uncertainty is obtained by simultaneous remeasurement of the Al(d,x){sup 24}Na or Ti(d,x){sup 48}V monitor reactions over the whole energy range. A comparison with experimental literature values and results from updated theoretical codes (ALICE-D, EMPIRE-D and the TENDL2010 on-line library) is discussed.

  2. Cross sections of deuteron induced reactions on natCr up to 50 MeV: Experiments and comparison with theoretical codes

    Science.gov (United States)

    Hermanne, A.; Adam Rebeles, R.; Tárkányi, F.; Takács, S.; Takács, M.; Ignatyuk, A.

    2011-11-01

    Activation of Cr-containing components around high energy deuteron accelerator can pose radioprotection problems for maintenance personnel. In a stacked foil irradiation, followed by high resolution gamma spectroscopy the cross sections for production of 46,47,48Sc, 51Cr, 52,54Mn and 48V were measured up to 50 MeV resulting in first systematic assessment above 15 MeV. Reduced uncertainty is obtained by simultaneous remeasurement of the Al(d,x) 24Na or Ti(d,x) 48V monitor reactions over the whole energy range. A comparison with experimental literature values and results from updated theoretical codes (ALICE-D, EMPIRE-D and the TENDL2010 on-line library) is discussed.

  3. Submillimeter ionoacoustic range determination for protons in water at a clinical synchrocyclotron

    Science.gov (United States)

    Lehrack, Sebastian; Assmann, Walter; Bertrand, Damien; Henrotin, Sebastien; Herault, Joel; Heymans, Vincent; Vander Stappen, Francois; Thirolf, Peter G.; Vidal, Marie; Van de Walle, Jarno; Parodi, Katia

    2017-09-01

    Proton ranges in water between 145 MeV to 227 MeV initial energy have been measured at a clinical superconducting synchrocyclotron using the acoustic signal induced by the ion dose deposition (ionoacoustic effect). Detection of ultrasound waves was performed by a very sensitive hydrophone and signals were stored in a digital oscilloscope triggered by secondary prompt gammas. The ionoacoustic range measurements were compared to existing range data from a calibrated range detector setup on-site and agreement of better than 1 mm was found at a Bragg peak dose of about 10 Gy for 220 MeV initial proton energy, compatible with the experimental errors. Ionoacoustics has thus the potential to measure the Bragg peak position with submillimeter accuracy during proton therapy, possibly correlated with ultrasound tissue imaging.

  4. High spin cluster-like resonances in the /sup 16/O + /sup 24/Mg system. [17 to 31 MeV, J,. pi. , angular distribution, differential cross sections, excitation functions, resonance

    Energy Technology Data Exchange (ETDEWEB)

    Lee, S.M.; Adloff, J.C.; Chevallier, P.; Disdier, D.; Rauch, V.; Scheibling, F.

    1978-01-01

    To see whether Molecular Resonances may be observed for A>32 systems, the /sup 16/O + /sup 24/Mg reaction was investigated in the 17 to 31 MeV (CM) energy range. Despite the broad structure behavior of the /sup 24/Mg + /sup 16/O outgoing channels, several rather narrow (GAMMA/sub tot/less than or equal to 500 keV) correlated resonances were observed for the /sup 28/Si + /sup 12/C channels at backward angles. The angular distributions of two of these resonances at E/sub CM/ = 21.6 MeV and 28.0 MeV show J/sup ..pi../ = (15/sup -/) and (21/sup -/), respectively. 1 reference.

  5. Neutron and proton nuclear data evaluation for sup 2 sup 3 sup 5 U and sup 2 sup 3 sup 8 U at energies up to 250 MeV

    CERN Document Server

    Konobeyev, A Y; Iwamoto, O

    2002-01-01

    Basic features of nuclear data evaluation for uranium isotopes sup 2 sup 3 sup 5 U and sup 2 sup 3 sup 8 U at intermediate energies are described. The coupled channel optical model was used to obtain total cross section, reaction cross section, angular distributions and transmission coefficients. The direct, pre-compound and evaporation models were used to describe neutron and charged particles emission from excited nuclei. The neutron data evaluated were combined with JENDL-3.3 data below 20 MeV to obtain a full data set in the whole energy range between 10 sup - sup 5 eV an 250 MeV. Evaluation of the proton data has been done at energies from 1 to 250 MeV.

  6. Shielding calculations for industrial 5/7.5MeV electron accelerators using the MCNP Monte Carlo Code

    Science.gov (United States)

    Peri, Eyal; Orion, Itzhak

    2017-09-01

    High energy X-rays from accelerators are used to irradiate food ingredients to prevent growth and development of unwanted biological organisms in food, and by that extend the shelf life of the products. The production of X-rays is done by accelerating 5 MeV electrons and bombarding them into a heavy target (high Z). Since 2004, the FDA has approved using 7.5 MeV energy, providing higher production rates with lower treatments costs. In this study we calculated all the essential data needed for a straightforward concrete shielding design of typical food accelerator rooms. The following evaluation is done using the MCNP Monte Carlo code system: (1) Angular dependence (0-180°) of photon dose rate for 5 MeV and 7.5 MeV electron beams bombarding iron, aluminum, gold, tantalum, and tungsten targets. (2) Angular dependence (0-180°) spectral distribution simulations of bremsstrahlung for gold, tantalum, and tungsten bombarded by 5 MeV and 7.5 MeV electron beams. (3) Concrete attenuation calculations in several photon emission angles for the 5 MeV and 7.5 MeV electron beams bombarding a tantalum target. Based on the simulation, we calculated the expected increase in dose rate for facilities intending to increase the energy from 5 MeV to 7.5 MeV, and the concrete width needed to be added in order to keep the existing dose rate unchanged.

  7. Present developments of research MeV Pelletron ion implantation systems

    Science.gov (United States)

    Norton, G. A.; Daniel, R. E.; Loger, R. L.; Schroeder, J. B.

    1989-02-01

    National Electrostatics Corp. has manufactured 79 ion beam systems. 17 of these Pelletron systems were designed with MeV ion implantation capability as a primary objective. Of these system, 8 were designed specifically for production ion implantation with a maximum beam energy of 4 MeV. For research applications, ion beam masses from carbon through gold have been accelerated with a maximum observed energy of 38 MeV from a 3 MV tandem S-series Pelletron. This paper will present performance charts which describe the observed ion beam capabilities of existing 3 MV tandem Pelletrons. In addition, the performance of the new high current, four charging chain, S-Series accelerator, currently in manufacture, will be given. A new 4 MV tandem S-Series Pelletron has been proposed, its expected capabilities will be stated. The NEC electrostatics raster scanner which is in use for MeV implantation provides uniform deposition at a maximum scan angle of ± 3.0 ° for 4 MeV doubly charged ions. The output wave form at ±10 kV scanning potential will be shown.

  8. A dynamic programming approach for quickly estimating large network-based MEV models

    DEFF Research Database (Denmark)

    Mai, Tien; Frejinger, Emma; Fosgerau, Mogens

    2017-01-01

    We propose a way to estimate a family of static Multivariate Extreme Value (MEV) models with large choice sets in short computational time. The resulting model is also straightforward and fast to use for prediction. Following Daly and Bierlaire (2006), the correlation structure is defined by a ro...... to converge (4.3 h on an Intel(R) 3.2 GHz machine using a non-parallelized code). We also show that our approach allows to estimate a cross-nested logit model of 111 nests with a real data set of more than 100,000 observations in 14 h.......We propose a way to estimate a family of static Multivariate Extreme Value (MEV) models with large choice sets in short computational time. The resulting model is also straightforward and fast to use for prediction. Following Daly and Bierlaire (2006), the correlation structure is defined...... by a rooted, directed graph where each node without successor is an alternative. We formulate a family of MEV models as dynamic discrete choice models on graphs of correlation structures and show that the dynamic models are consistent with MEV theory and generalize the network MEV model (Daly and Bierlaire...

  9. Resonant transition radiation in the X-ray region from a low emittance 855 MeV electron beam

    Energy Technology Data Exchange (ETDEWEB)

    Backe, H. (Inst. fuer Physik, Univ. Mainz (Germany)); Gampert, S. (Inst. fuer Physik, Univ. Mainz (Germany)); Grendel, A. (Inst. fuer Physik, Univ. Mainz (Germany)); Hartmann, H.J. (Inst. fuer Physik, Univ. Mainz (Germany)); Lauth, W.; Weinheimer, C.; Zahn, R. (Inst. fuer Physik, Univ. Mainz (Germany)); Buskirk, F.R. (Inst. fuer Kernphysik, Univ. Mainz (Germany)); Euteneuer, H. (Inst. fuer Kernphysik, Univ. Mainz (Germany)); Kaiser, K.H. (Inst. fuer Kernphysik, Univ. Mainz (Germany)); Stephan, G. (Inst. fuer Kernphysik, Univ. Mainz (Germany)); Walcher, T. (Inst. fuer Kernphysik, Univ. Mainz (Germany))

    1994-07-01

    The interference of transition radiation coherently produced from a periodic stack of four polyimide foils of 7.2 [mu]m thickness and a separation of 162 [mu]m was investigated. This stack has been brought into the low emittance (3 [pi] nm rad) electron beam of the 855 MeV Mainz Microtron MAMI. Transition radiation was observed in the energy range from 2 to 15 keV with a LN[sub 2]-cooled pin photodiode. A good energy resolution of 0.8 keV and angular resolution of 0.15 mrad was achieved simultaneously allowing for the first time to quantitatively study the interference pattern. Good agreement with theoretical calculations is found. Prospects to exploit transition radiation in the x-ray region from a low emittance electron beam as a high brilliant radiation source are discussed. (orig.)

  10. Beam-dump/diagnostics box for a 10-kA 50-MeV, 50-ns electron beam

    Energy Technology Data Exchange (ETDEWEB)

    White, J.M.; Fessenden, T.J.; Fontaine, R.A.; Harvey, A.R.; Paul, A.C.

    1983-03-09

    We have developed a dump for the ATA beam that consists of a series of carbon plates whose collective thickness totals approximately 1.5 ranges at 50 MeV. The energy dissipated in the plates is radiated to a water-cooled wall. The dump is designed to dissipate up to 175 kW of average power. A small hole along the axis of the plates forms a beamlet that passes through an energy analyzer. The analyzer consists of a 60/sup 0/ bending magnet and two high-sensitivity beam-current/position monitors. The ratio of the beamlet current to full current is used to estimate the beam emittance.

  11. An integral test of FLUKA nuclear models with 160 MeV proton beams in multi-layer Faraday cups

    CERN Document Server

    Rinaldi, I; Parodi, K; Ferrari, A; Sala, P; Mairani, A

    2011-01-01

    Monte Carlo (MC) codes are useful tools to simulate the complex processes of proton beam interactions with matter. In proton therapy, nuclear reactions influence the dose distribution. Therefore, the validation of nuclear models adopted in MC codes is a critical requisite for their use in this field. A simple integral test can be performed using a multi-layer Faraday cup (MLFC). This method allows separation of the nuclear and atomic interaction processes, which are responsible for secondary particle emission and the finite primary proton range, respectively. In this work, the propagation of 160 MeV protons stopping in two MLFCs made of polyethylene and copper has been simulated by the FLUKA MC code. The calculations have been performed with and without secondary electron emission and transport, as well as charge sharing in the dielectric layers. Previous results with other codes neglected those two effects. The impact of this approximation has been investigated and found to be relevant only in the proximity ...

  12. BPW34 Commercial p-i-n Diodes for High-Level 1-MeV Neutron Equivalent Fluence Monitoring

    CERN Document Server

    Ravotti, F; Moll, M; Saigne, F

    2008-01-01

    The BPW34 p-i-n diode was characterized at CERN in view of its utilization as radiation monitor at the LHC to cover the broad 1-MeV neutron equivalent fluence (Phieq) range expected for the LHC machine and experiments during operation. Electrical measurements for both forward and reverse bias were used to characterize the device and to understand its behavior under irradiation. When the device is powered forward, a sensitivity to fast hadrons for Phieq > 2 times1012 cm-2 has been observed. With increasing particle fluences the forward I- V characteristics of the diode shifts towards higher voltages. At Phieq > 3times1013 cm-2, the forward characteristic starts to bend back assuming a thyristor-like behavior. An explanation for this phenomenon is given in this article. Finally, detailed radiation-response curves for the forward bias-operation and annealing studies of the diode's forward voltage are presented for proton, neutron and gamma irradiation.

  13. Modifications in physico-chemical properties of 100 MeV oxygen ions irradiated polyimide Kapton-H polymer

    Science.gov (United States)

    Gupta, Sanjeev Kumar; Gupta, Rashi; Singh, Paramjit; Kumar, Vikas; Jaiswal, Manoj Kumar; Chakarvarti, S. K.; Kumar, Rajesh

    2017-09-01

    The optical, structural and chemical properties of polyimide Kapton-H polymer thin film samples were modified by irradiation with 100 MeV O7+ ions (in the fluence range of 1 × 1011 to 5 × 1012 ions/cm2) and the modifications of these properties were observed by UV-visible (UV-Vis) spectroscopy, X-ray diffraction (XRD) and Fourier transform infrared (FTIR) spectroscopy respectively. The band gap energy of the polymer decreased considerably with discrete increment of the ion fluence (different fluence for each sample) and effective change for the sample irradiated at a fluence of 5 × 1012 ions/cm2 was observed from that of pristine sample. The amorphous nature of the polymer was observed to be decreased with increase of ion fluence. The vibrations of Ctbnd C appeared at mid fluences but the stretching vibrations of Osbnd H bond disappeared at these fluences due to the high LET of the oxygen ions.

  14. Energy straggling of 60 MeV {sup 58}Ni{sup q+} ions in thin carbon foils and gases

    Energy Technology Data Exchange (ETDEWEB)

    Schmelmer, O.; Dollinger, G.; Frey, C.M.; Bergmaier, A.; Karsch, S. [Physik-Department E12, Technische Universitaet Muenchen, James-Franck-Strasse, D-85748 Garching (Germany)

    1998-11-01

    Energy straggling of 60 MeV {sup 58}Ni{sup q+} ions in thin carbon foils and gas layers has been measured with a Q3D magnetic spectrograph in dependence of the incident and analysed charge state of the ions. The straggling increases with the number of electrons per gas molecule, thus showing strong correlation effects. In solid carbon, however, energy straggling is close to the data of deuterium gas. The small straggling in carbon is interpreted as an effect of the long range interaction of the heavy ions in dense solids. Furthermore, it is observed that energy straggling depends on the charge state of the projectiles unless the equilibrium charge state is reached. (Copyright (c) 1998 Elsevier Science B.V., Amsterdam. All rights reserved.)

  15. Measurement of excitation functions in proton induced reactions on natural copper from their threshold to 43 MeV

    Science.gov (United States)

    Shahid, Muhammad; Kim, Kwangsoo; Naik, Haladhara; Zaman, Muhammad; Yang, Sung-Chul; Kim, Guinyun

    2015-01-01

    We have measured the production cross-sections of the residual radionuclides from proton-induced reactions of natCu by using a stacked-foil activation and off-line γ-ray spectrometric technique in the energy range from their respective threshold to 43 MeV at the MC-50 cyclotron of the Korea Institute of Radiological and Medical Sciences. The measured results were compared with the earlier reported data as well as with the theoretical values obtained from the TENDL-2013 library based on the TALYS 1.6 code. The integral yields for thick target of the investigated radio-nuclides were calculated from the measured excitation function and the stopping power of natCu.

  16. Production cross-sections of radionuclides from α-induced reactions on natural copper up to 50MeV.

    Science.gov (United States)

    Usman, Ahmed Rufai; Khandaker, Mayeen Uddin; Haba, Hiromitsu; Otuka, Naohiko; Murakami, Masashi; Komori, Yukiko

    2016-08-01

    The excitation functions were measured for the (nat)Cu(α,x)(66,67)Ga,(65)Zn,(57,58,60)Co reactions in the energy range of 16.5 -50MeV. A conventional stacked-foil activation technique combined with HPGe γ-ray spectrometry was employed to determine cross-sections. The measured cross-sections were critically compared with relevant previous experimental data and also with the evaluated data in the TENDL-2014 library. Present results confirmed some of the previous experimental data, whereas only a partial agreement was found with the evaluated data. The measured data are useful for reducing the existing discrepancies in the literature, to improve the nuclear reaction model codes, and to enrich the experimental database towards various applications. Copyright © 2016 Elsevier Ltd. All rights reserved.

  17. Excitation functions of the proton-induced nuclear reactions on natSn up to 40 MeV

    Science.gov (United States)

    Khandaker, Mayeen Uddin; Kim, Kwangsoo; Kim, Kyung-Sook; Lee, Manwoo; Lee, Young Seok; Kim, Guinyun; Cho, Young-Sik; Lee, Young-Ouk

    2009-01-01

    We have measured the production cross-sections of the residual radionuclides for proton-induced reactions on natural tin by using a stacked-foil activation technique in the energy range from threshold energy to 40 MeV at the MC-50 cyclotron of the Korea Institute of Radiological and Medical Sciences. The results were compared with the earlier reported experimental data and theoretical calculations based on the TALYS and the ALICE-IPPE codes. The present results are in general good agreement with the available literature data and calculated results by using the computer codes TALYS and ALICE-IPPE. The thick target integral yields were also deduced from the measured excitation functions of the produced radionuclides.

  18. Measurement of excitation functions in proton induced reactions on natural copper from their threshold to 43 MeV

    Energy Technology Data Exchange (ETDEWEB)

    Shahid, Muhammad; Kim, Kwangsoo [Department of Physics, Kyungpook National University, Daegu 702-701 (Korea, Republic of); Naik, Haladhara [Radiochemistry Division, Bhabha Atomic Research Centre, Mumbai 400085 (India); Zaman, Muhammad [Department of Physics, Kyungpook National University, Daegu 702-701 (Korea, Republic of); Yang, Sung-Chul [Department of Physics, Kyungpook National University, Daegu 702-701 (Korea, Republic of); Nuclear Data Center, Korea Atomic Energy Research Institute, Daejeon 305-353 (Korea, Republic of); Kim, Guinyun, E-mail: gnkim@knu.ac.kr [Department of Physics, Kyungpook National University, Daegu 702-701 (Korea, Republic of)

    2015-01-01

    We have measured the production cross-sections of the residual radionuclides from proton-induced reactions of {sup nat}Cu by using a stacked-foil activation and off-line γ-ray spectrometric technique in the energy range from their respective threshold to 43 MeV at the MC-50 cyclotron of the Korea Institute of Radiological and Medical Sciences. The measured results were compared with the earlier reported data as well as with the theoretical values obtained from the TENDL-2013 library based on the TALYS 1.6 code. The integral yields for thick target of the investigated radio-nuclides were calculated from the measured excitation function and the stopping power of {sup nat}Cu.

  19. Conceptual design of magnetic spectrometer for inverse-Compton X-ray source in MeV region

    Directory of Open Access Journals (Sweden)

    Xinjian Tan

    2017-10-01

    Full Text Available A novel magnetic spectrometer for Inverse-Compton X-ray source is proposed. Compton recoil electrons are generated by a lithium converter, and then confined by a complex collimator and spectrally resolved by a sector-shaped double-focusing magnet. A method of optimization for the converter is investigated, and the dependence of the best energy resolution on converting efficiency is quantitatively revealed. The configuration of the magnet is specially designed to cover a wide range of electron energy and to achieve a large collecting solid angle. The efficiency and relative energy resolution of the designed spectrometer, according to Monte-Carlo simulation using Geant4, are 10-4 e/p and about 5% respectively for 3 MeV photons.

  20. Stopping power of SiO sub 2 for 0.2-3.0 MeV He ions

    CERN Document Server

    Pascual-Izarra, C; Lulli, G; Summonte, C

    2002-01-01

    The stopping power of SiO sub 2 for 200 keV-3 MeV He ions has been evaluated by Rutherford backscattering (RBS) and a semiempirical stopping power curve is proposed in this energy range. The curve is parameterized using the Andersen and Ziegler's formula, allowing for an easy implementation in any simulation program. The estimated accuracy of the present stopping power curve is of the order of 2%. Samples used for the measurements consist of thin SiO sub 2 films grown by wet thermal oxidation of Si(1 0 0) wafers. The thickness of each sample was independently determined by reflectance spectroscopy. The fitting of the experimental RBS spectra was performed using full Monte Carlo calculation of trajectories in the binary collision approximation.

  1. Rapid and direct micro-machining/patterning of polymer materials by oxygen MeV ion beam irradiation through masks

    Energy Technology Data Exchange (ETDEWEB)

    Brun, S., E-mail: sebastien.brun@he-arc.ch [Institut des Microtechnologies Appliquees, Eplatures-Grise 17, 2300 La Chaux-de-Fonds (Switzerland); Guibert, G. [Institut des Microtechnologies Appliquees, Eplatures-Grise 17, 2300 La Chaux-de-Fonds (Switzerland); Meunier, C. [Universite de Franche Comte, Institut FEMTO-ST, UMR 6174 CNRS, 4 Place Tharradin, BP 71427, 25211 Montbeliard (France); Guibert, E.; Keppner, H.; Mikhailov, S. [Institut des Microtechnologies Appliquees, Eplatures-Grise 17, 2300 La Chaux-de-Fonds (Switzerland)

    2011-10-15

    PTFE (PolyTetraFluoroEthylene), often called Teflon, is a well-known polymer for being a non-stick material with good thermal properties. Moreover, PTFE is biocompatible and especially it is a cyto-compatible polymer. To enable bonding, a chemical etching based on sodium solutions is generally used to modify surfaces. In this paper we study the etching of PTFE using an oxygen ion beam in the MeV energy range. We present micro-patterning of PTFE through masks with two fluences of 5 x 10{sup 15} and 1 x 10{sup 16} ion cm{sup -2}. As is demonstrated the use of a mask allows structuring of large areas while maintaining a distance between the mask and sample makes industrial applications possible.

  2. Highly Stripped Ion Sources for MeV Ion Implantation

    Energy Technology Data Exchange (ETDEWEB)

    Hershcovitch, Ady

    2009-06-30

    Original technical objectives of CRADA number PVI C-03-09 between BNL and Poole Ventura, Inc. (PVI) were to develop an intense, high charge state, ion source for MeV ion implanters. Present day high-energy ion implanters utilize low charge state (usually single charge) ion sources in combination with rf accelerators. Usually, a MV LINAC is used for acceleration of a few rnA. It is desirable to have instead an intense, high charge state ion source on a relatively low energy platform (de acceleration) to generate high-energy ion beams for implantation. This de acceleration of ions will be far more efficient (in energy utilization). The resultant implanter will be smaller in size. It will generate higher quality ion beams (with lower emittance) for fabrication of superior semiconductor products. In addition to energy and cost savings, the implanter will operate at a lower level of health risks associated with ion implantation. An additional aim of the project was to producing a product that can lead to long­ term job creation in Russia and/or in the US. R&D was conducted in two Russian Centers (one in Tomsk and Seversk, the other in Moscow) under the guidance ofPVI personnel and the BNL PI. Multiple approaches were pursued, developed, and tested at various locations with the best candidate for commercialization delivered and tested at on an implanter at the PVI client Axcelis. Technical developments were exciting: record output currents of high charge state phosphorus and antimony were achieved; a Calutron-Bemas ion source with a 70% output of boron ion current (compared to 25% in present state-of-the-art). Record steady state output currents of higher charge state phosphorous and antimony and P ions: P{sup 2+} (8.6 pmA), P{sup 3+} (1.9 pmA), and P{sup 4+} (0.12 pmA) and 16.2, 7.6, 3.3, and 2.2 pmA of Sb{sup 3+} Sb {sup 4 +}, Sb{sup 5+}, and Sb{sup 6+} respectively. Ultimate commercialization goals did not succeed (even though a number of the products like high

  3. Determination of neutron capture cross sections of 232Th at 14.1 MeV and 14.8 MeV using the neutron activation method

    Science.gov (United States)

    Lan, Chang-Lin; Zhang, Yi; Lv, Tao; Xie, Bao-Lin; Peng, Meng; Yao, Ze-En; Chen, Jin-Gen; Kong, Xiang-Zhong

    2017-04-01

    The 232Th(n, γ)233Th neutron capture reaction cross sections were measured at average neutron energies of 14.1 MeV and 14.8 MeV using the activation method. The neutron flux was determined using the monitor reaction 27Al(n,α)24Na. The induced gamma-ray activities were measured using a low background gamma ray spectrometer equipped with a high resolution HPGe detector. The experimentally determined cross sections were compared with the data in the literature, and the evaluated data of ENDF/B-VII.1, JENDL-4.0u+, and CENDL-3.1. The excitation functions of the 232Th(n,γ)233Th reaction were also calculated theoretically using the TALYS1.6 computer code. Supported by Chinese TMSR Strategic Pioneer Science and Technology Project-The Th-U Fuel Physics Term (XDA02010100) and National Natural Science Foundation of China (11205076, 21327801)

  4. Independent isotopic yields in 25 MeV and 50 MeV proton-induced fission of {sup nat}U

    Energy Technology Data Exchange (ETDEWEB)

    Penttilae, H.; Gorelov, D.; Elomaa, V.V.; Eronen, T.; Hager, U.; Hakala, J.; Jokinen, A.; Kankainen, A.; Karvonen, P.; Moore, I.D.; Parkkonen, J.; Pohjalainen, I.; Rahaman, S.; Rinta-Antila, S.; Rissanen, J.; Saastamoinen, A.; Simutkin, V.; Sonoda, T.; Weber, C.; Voss, A.; Aeystoe, J. [Department of Physics, University of Jyvaskylae (Finland); Peraejaervi, K. [STUK - Radiation and Nuclear Safety Authority, Helsinki (Finland); Rubchenya, V.A. [Department of Physics, University of Jyvaskylae (Finland); V.G. Khlopin Radium Institute, St. Petersburg (Russian Federation)

    2016-04-15

    Independent isotopic yields for elements from Zn to La in the 25 MeV proton-induced fission of {sup nat}U were determined with the JYFLTRAP facility. In addition, isotopic yields for Zn, Ga, Rb, Sr, Zr, Pd and Xe in the 50 MeV proton-induced fission of {sup nat}U were measured. The deduced isotopic yield distributions are compared with a Rubchenya model, the GEF model with universal parameters and the semi-empirical Wahl model. Of these, the Rubchenya model gives the best overall agreement with the obtained data. Combining the isotopic yield data with mass yield data to obtain the absolute independent yields was attempted. The result depends on the mass yield distribution. (orig.)

  5. Analysis of a measured neutron background below 6 MeV for fast-neutron imaging systems

    Science.gov (United States)

    Ide, K.; Becchetti, M. F.; Flaska, M.; Poitrasson-Riviere, A.; Hamel, M. C.; Polack, J. K.; Lawrence, C. C.; Clarke, S. D.; Pozzi, S. A.

    2012-12-01

    Detailed and accurate information on the neutron background is relevant for many applications that involve radiation detection, both for non-coincidence and coincidence countings. In particular, for the purpose of developing advanced neutron-detection techniques for nuclear non-proliferation and nuclear safeguards, the energy-dependent, ground-level, neutron-background information is needed. There are only a few previous studies available about the neutron background below 10 MeV, which is a typical neutron energy range of interest for nuclear non-proliferation and nuclear-safeguards applications. Thus, there is a potential for further investigation in this energy range. In this paper, neutron-background measurement results using organic-liquid scintillation detectors are described and discussed, with a direct application in optimization simulations of a fast-neutron imager based on liquid scintillators. The measurement was performed in summer 2011 in Ann Arbor, Michigan, USA, and the measurement setup consisted of several EJ-309 liquid scintillators and a fast waveform digitizer. The average neutron flux below 6 MeV was measured to be approximately 4e-4 counts/cm2/s. In addition, the relationship between the neutron-background count rate and various environmental quantities, such as humidity, at Earth's ground level was investigated and the results did not reveal any straightforward dependences. The measured pulse height distribution (PHD) was unfolded to determine the energy spectrum of the background neutrons. The unfolded neutron-background spectrum was implemented to a previously-created MCNPX-PoliMi model of the neutron-scatter camera and simple-backprojection images of the background neutrons were acquired. Furthermore, a simulated PHD was obtained with the MCNPX-PoliMi code using the "Cosmic-Ray Shower Library" (CRY) source sub-routine which returns various types of radiation, including neutrons and photons at a surface, and accounts for solar cycle

  6. New excitation functions for proton induced reactions on natural titanium, nickel and copper up to 70 MeV

    Energy Technology Data Exchange (ETDEWEB)

    Garrido, E. [SUBATECH, Ecole des Mines de Nantes, Université de Nantes, CNRS/IN2P3, Nantes (France); Duchemin, C., E-mail: Charlotte.Duchemin@subatech.in2p3.fr [SUBATECH, Ecole des Mines de Nantes, Université de Nantes, CNRS/IN2P3, Nantes (France); Guertin, A. [SUBATECH, Ecole des Mines de Nantes, Université de Nantes, CNRS/IN2P3, Nantes (France); Haddad, F.; Michel, N. [SUBATECH, Ecole des Mines de Nantes, Université de Nantes, CNRS/IN2P3, Nantes (France); GIP Arronax, 1 rue Aronnax, 44817 Saint-Herblain (France); Métivier, V. [SUBATECH, Ecole des Mines de Nantes, Université de Nantes, CNRS/IN2P3, Nantes (France)

    2016-09-15

    Highlights: • Natural titanium, nickel and copper targets. • 70 MeV ARRONAX cyclotron proton beam. • Stacked-foil technique and monitor reactions. • Experimental cross section values. • TALYS code version 1.6. - Abstract: New excitation functions for proton induced nuclear reactions on natural titanium, nickel and copper were measured, using the stacked-foil technique and gamma spectrometry, up to 70 MeV. The experimental cross sections were measured using the Ti-nat(p,x) V-48, Ni-nat(p,x) Ni-57 and Cu-nat(p,x) Zn-62,Co-56 monitor reactions recommended by the International Atomic Energy Agency (IAEA), depending on the investigated energy range. Data have been extracted for the Ti-nat(p,x) Sc-43,44m,46,47,48, V-48, K-42,43, Ni-nat(p,x) Ni-56,57, Co-55,56,57,58, Mn-52,54, Cu-nat(p,x) Cu-61,64, Ni-57, Co-56,57,58,60, Zn-62,65, Mn-54 reactions. Our results are discussed and compared to the existing ones as well as with the TALYS code version 1.6 calculations using default models. Our experimental data are in overall good agreement with the literature. TALYS is able to reproduce, in most cases, the experimental trend. Our new experimental results allow to expand our knowledge on these excitation functions, to confirm the existing trends and to give additional values on a large energy range. This work is in line with the new Coordinated Research Project (CRP) launched by the IAEA to expand the database of monitor reactions.

  7. Digital neutron/gamma discrimination with an organic scintillator at energies between 1 MeV and 100 MeV

    Energy Technology Data Exchange (ETDEWEB)

    Comrie, A.C. [Department of Physics, University of Cape Town, Rondebosch 7700 (South Africa); Buffler, A., E-mail: andy.buffler@uct.ac.za [Department of Physics, University of Cape Town, Rondebosch 7700 (South Africa); Smit, F.D. [iThemba LABS, Somerset West 7129 (South Africa); Wörtche, H.J. [INCAS" 3, Dr. Nassaulaan 9. 9400 AT Assen (Netherlands)

    2015-02-01

    Three different digital implementations of pulse shape discrimination for pulses from an EJ301 liquid scintillator detector are presented, and illustrated with neutrons and gamma-rays produced by an Am–Be radioisotopic source, a D–T generator and beams produced by cyclotron-accelerated protons of energies 42, 62 and 100 MeV on a Li target. A critical comparison between the three methods is provided.

  8. Low dose irradiation creep of pure nickel. [17 or 15 MeV deuterons

    Energy Technology Data Exchange (ETDEWEB)

    Henager, C.H. Jr.

    1984-10-01

    A detailed climb-controlled glide model of low dose irradiation creep has been developed to rationalize irradiation creep data of pure nickel irradiated in a light ion irradiation creep apparatus. Experimental irradiation creep data were obtained to study the effects of initial microstructure and stress on low dose irradiation creep in pure nickel. Pure nickel specimens (99.992% Ni), with three different microstructures, were irradiated with 17 or 15 MeV deuterons at 473 K and stresses ranging from 0.35 to 0.9 of the unirradiated yield stress. Transmission electron microscopy revealed that the microstructure following irradiation to 0.05 dpa consisted of a high density of small dislocation loops, some small voids and network dislocations. The creep model predicted creep rates proportional to the mobile dislocation density and a comparison of experimental irradiation creep rates as a function of homologous stress revealed a dependence on initial microstructure of the magnitude predicted by the measured dislocation densities. The three microstructures that were irradiated consisted of 85% and 25% cold-worked Ni specimens and well-annealed Ni specimens. A weak stress dependence of irradiation creep was observed in 85% cold-worked Ni in agreement with experimental determinations of the stress dependence of irradiation creep by others. The weak stress dependence was shown to be a consequence of the stress independence of the dislocation climb velocity and the weak stress dependence of the barrier removal process. The irradiation creep rate was observed to be proportional to the applied stress. This linear stress dependence was suggested to be due to the stress dependence of the mobile dislocation density. 101 references, 27 figures, 11 tables.

  9. The Evolution of Swift/BAT blazars and the origin of the MeV background

    Energy Technology Data Exchange (ETDEWEB)

    Ajello, M.; /SLAC /KIPAC, Menlo Park; Costamante, L.; /Stanford U., HEPL /KIPAC, Menlo Park; Sambruna, R.M.; Gehrels, N.; /NASA, Goddard; Chiang, J.; /SLAC /KIPAC, Menlo Park; Rau, A.; /Caltech; Escala, A.; /SLAC /KIPAC, Menlo Park /Cerro Calan Observ.; Greiner, J.; /Garching, Max Planck Inst., MPE; Tueller, J.; /NASA, Goddard; Wall, J.V.; /British Columbia U.; Mushotzky, R.F.; /NASA, Goddard

    2009-10-17

    We use 3 years of data from the Swift/BAT survey to select a complete sample of X-ray blazars above 15 keV. This sample comprises 26 Flat-Spectrum Radio Quasars (FSRQs) and 12 BL Lac objects detected over a redshift range of 0.03 < z < 4.0. We use this sample to determine, for the first time in the 15-55 keV band, the evolution of blazars. We find that, contrary to the Seyfert-like AGNs detected by BAT, the population of blazars shows strong positive evolution. This evolution is comparable to the evolution of luminous optical QSOs and luminous X-ray selected AGNs. We also find evidence for an epoch-dependence of the evolution as determined previously for radio-quiet AGNs. We interpret both these findings as a strong link between accretion and jet activity. In our sample, the FSRQs evolve strongly, while our best-fit shows that BL Lacs might not evolve at all. The blazar population accounts for 10-20% (depending on the evolution of the BL Lacs) of the Cosmic X-ray background (CXB) in the 15-55 keV band. We find that FSRQs can explain the entire CXB emission for energies above 500 keV solving the mystery of the generation of the MeV background. The evolution of luminous FSRQs shows a peak in redshift (z{sub c} = 4.3 {+-} 0.5) which is larger than the one observed in QSOs and X-ray selected AGNs. We argue that FSRQs can be used as tracers of massive elliptical galaxies in the early Universe.

  10. Trimming algorithm of frequency modulation for CIAE-230 MeV proton superconducting synchrocyclotron model cavity

    Energy Technology Data Exchange (ETDEWEB)

    Li, Pengzhan, E-mail: lipengzhan@ciae.ac.cn; Zhang, Tianjue; Ji, Bin; Hou, Shigang; Guo, Juanjuan; Yin, Meng; Xing, Jiansheng; Lv, Yinlong; Guan, Fengping; Lin, Jun

    2017-01-21

    A new project, the 230 MeV proton superconducting synchrocyclotron for cancer therapy, was proposed at CIAE in 2013. A model cavity is designed to verify the frequency modulation trimming algorithm featuring a half-wave structure and eight sets of rotating blades for 1 kHz frequency modulation. Based on the electromagnetic (EM) field distribution analysis of the model cavity, the variable capacitor works as a function of time and the frequency can be written in Maclaurin series. Curve fitting is applied for theoretical frequency and original simulation frequency. The second-order fitting excels at the approximation given its minimum variance. Constant equivalent inductance is considered as an important condition in the calculation. The equivalent parameters of theoretical frequency can be achieved through this conversion. Then the trimming formula for rotor blade outer radius is found by discretization in time domain. Simulation verification has been performed and the results show that the calculation radius with minus 0.012 m yields an acceptable result. The trimming amendment in the time range of 0.328–0.4 ms helps to reduce the frequency error to 0.69% in Simulation C with an increment of 0.075 mm/0.001 ms, which is half of the error in Simulation A (constant radius in 0.328–0.4 ms). The verification confirms the feasibility of the trimming algorithm for synchrocyclotron frequency modulation. - Highlights: • A model cavity is designed to verify the trimming algorithm of frequency modulation. • The RF frequency is expressed by fitting approximation and Maclaurin series. • The variable capacitor of the cavity works as a function of time. • The trimming formula for blade radius is found by discretization in time domain. • The amendment solution helps to reduce the frequency error.

  11. A comparison of 4 MeV Proton and Co-60 gamma irradiation induced degradation in the electrical characteristics of N-channel MOSFETs

    Energy Technology Data Exchange (ETDEWEB)

    Anjum, Arshiya; Vinayakprasanna, N.H.; Pradeep, T.M. [Department of Studies in Physics, University of Mysore, Manasagangotri, Mysore 570006 (India); Pushpa, N. [Department of PG Studies in Physics, JSS College, Ooty Road, Mysore 570025 (India); Krishna, J.B.M. [IUC-DAE CSR, Kolkota 700098 (India); Gnana Prakash, A.P., E-mail: gnanaprakash@physics.uni-mysore.ac.in [Department of Studies in Physics, University of Mysore, Manasagangotri, Mysore 570006 (India)

    2016-07-15

    N-channel depletion MOSFETs were irradiated with 4 MeV Proton and Co-60 gamma radiation in the dose range of 100 krad(Si) to 100 Mrad(Si). The electrical characteristics of MOSFET such as threshold voltage (V{sub th}), density of interface trapped charges (ΔN{sub it}), density of oxide trapped charges (ΔN{sub ot}), transconductance (g{sub m}), mobility (μ), leakage current (I{sub L}) and drain saturation current (I{sub D} {sub Sat}) were studied as a function of dose. A considerable increase in ΔN{sub it} and ΔN{sub ot} and decrease in V{sub th,}g{sub m}, μ, and I{sub D} {sub Sat} was observed after irradiation. The results of 4 MeV Proton irradiation were compared with that of Co-60 gamma radiation and it is found that the degradation is more for the devices irradiated with 4 MeV Protons when compared with the Co-60 gamma radiation. This indicates that Protons induce more trapped charges in the field oxide region when compared to the gamma radiation.

  12. Ionoluminescence induced by 3 MeV He{sup +} ions on as-grown and pre-damaged BaMgF{sub 4} crystals

    Energy Technology Data Exchange (ETDEWEB)

    Peña-Rodríguez, O., E-mail: ovidio.pena@uam.es [Centro de Microanálisis de Materiales (CMAM), Universidad Autónoma de Madrid (UAM), Cantoblanco, E-28049 Madrid (Spain); Instituto de Óptica, Consejo Superior de Investigaciones Científicas, C/Serrano 121, E-28006 Madrid (Spain); Olivares, J. [Centro de Microanálisis de Materiales (CMAM), Universidad Autónoma de Madrid (UAM), Cantoblanco, E-28049 Madrid (Spain); Instituto de Óptica, Consejo Superior de Investigaciones Científicas, C/Serrano 121, E-28006 Madrid (Spain); Víllora, E.G.; Shimamura, K. [National Institute for Materials Center, 1-1 Namiki, Tsukuba 305-0044 (Japan); Agulló-López, F. [Centro de Microanálisis de Materiales (CMAM), Universidad Autónoma de Madrid (UAM), Cantoblanco, E-28049 Madrid (Spain)

    2013-04-15

    The ionoluminescence (IL) spectra and yields have been investigated on pristine and pre-damaged crystals of BaMgF{sub 4,} using a He probe beam at 3 MeV. The previous lattice damage has been produced by irradiation with Br ions at 15 MeV in the electronic stopping regime (S{sub e}=5.8 keV/nm⪢S{sub n}) and has been monitored by Rutherford-backscattering spectrometry in the channeling configuration (RBS/C). The IL spectra covering the wavelength range from 250 nm to 800 nm (∼1.5–5 eV) are similar for pristine and pre-irradiated crystals, but the IL emission yields exhibited a marked decrease with pre-irradiation fluence. A good correlation between such decrease and the generated structural damage has been established. Possible mechanisms for this behavior are discussed. -- Highlights: ► Ionoluminescence yields have been studied on BaMgF{sub 4} crystals using a He probe beam. ► The crystals were pre-damaged using various fluences of bromine ions at 15 MeV. ► Good correlation was found between the IL yield and the structural damage.

  13. Preliminary investigation of scintillator materials properties: SrI2:Eu, CeBr3 and GYGAG:Ce for gamma rays up to 9 MeV

    Science.gov (United States)

    Giaz, A.; Hull, G.; Fossati, V.; Cherepy, N.; Camera, F.; Blasi, N.; Brambilla, S.; Coelli, S.; Million, B.; Riboldi, S.

    2015-12-01

    In this work we measured the performance of a 2ʺ×2ʺ cylindrical tapered crystal of SrI2:Eu, a 2ʺ×3ʺ cylindrical sample of CeBr3 and a 2ʺ×0.3ʺ cylindrical sample of GYGAG:Ce. These scintillators are prototypes in volume or material and were provided by the Lawrence Livermore National Laboratory and by the Institut de Physique Nucléaire d'Orsay. The gamma-ray energy resolution was measured in the energy range of 0.1-9 MeV using different sources. Each scintillator was scanned along x, y and z axes, using a 400 MBq collimated 137Cs source. Owing to the GYGAG:Ce thickness, it was not possible to obtain the value of the energy resolution at 9 MeV and to scan the crystal along the z axis. The 662 keV full energy peak position and its FWHM were measured relative to the full energy peaks positions produced by a non-collimated 88Y source. The signals of the detectors were additionally digitized and compared, up to 9 MeV, using a 12 bit LeCroy 600 MHz oscilloscope.

  14. Effect of 50 and 80 MeV phosphorous ions on the contribution of interface and oxide state density in n-channel MOSFETs

    Energy Technology Data Exchange (ETDEWEB)

    Shinde, N.S.; Dhole, S.D.; Kanjilal, D.; Bhoraskar, V.N. E-mail: vnb@physics.unipune.ernet.in

    1999-07-02

    n-channel depletion MOS devices were irradiated with 50 and 80 MeV phosphorous ions, with different fluences varying in the range from 10{sup 11} to 10{sup 13} ions/cm{sup 2}. The pre and post irradiation I-V characteristics were measured and the corresponding threshold shift {delta}V{sub TH} was estimated. In both the cases, the drain current I{sub D} and the threshold voltage V{sub TH} were found to decrease with the ion fluence. The increase in the threshold voltage shift {delta}V{sub TH} with the ion fluence, was greater for the devices irradiated with 80 MeV ions than those irradiated with 50 MeV ions. The interface and oxide state densities were determined through the subthreshold voltage measurements. To separate the contributions of oxide and interface states towards the threshold voltage shift, the ion irradiated MOS devices were annealed at 150 deg. C. The threshold shift during annealing initially decreased and later increased with increasing annealing period. The rate of change of the interface states during annealing was higher than that of the oxide states. It was also found that depletion mode (normally ON) MOSFETs switched operation to enhancement mode (normally OFF)

  15. Depth profiling of fingerprint and ink signals by SIMS and MeV SIMS

    Energy Technology Data Exchange (ETDEWEB)

    Bailey, M.J., E-mail: m.bailey@surrey.ac.u [University of Surrey Ion Beam Centre, Surrey GU2 7XH (United Kingdom); Jones, B.N. [University of Surrey Ion Beam Centre, Surrey GU2 7XH (United Kingdom); Hinder, S.; Watts, J. [Surface Analysis Laboratory, University of Surrey, GU2 7XH (United Kingdom); Bleay, S. [Home Office Scientific Development Branch, St. Albans (United Kingdom); Webb, R.P. [University of Surrey Ion Beam Centre, Surrey GU2 7XH (United Kingdom)

    2010-06-15

    Police institutions currently have no analytical method of knowing whether a fingerprint was deposited before or after the document was written or printed. The suitability of using MeV secondary ion mass spectrometry (i.e. SIMS with an MeV ion beam) to determine the order in which a fingerprint and written text were deposited on paper was therefore investigated. A 10 MeV O{sup 4+} beam was used to generate secondary ions from the surface of the samples and to map the molecular fragments from doped fingerprints and inks on paper. The images obtained and the sputtering behaviour of the samples was found to be indicative of the sequence of ink and fingerprint deposits.

  16. Magnetic field calculation for a 13 MeV PET cyclotron

    CERN Document Server

    Yang, W Y; Oh, S; Chai, J S; Ha, J H

    1999-01-01

    A design study of the main magnet for a 13 MeV cyclotron has been carried out in a joint collaboration between the Korea Cancer Center Hospital (KCCH) and POSTECH. A maximum energy of 13 MeV has been chosen to produce radioisotopes such as /sup 18/F. There are four magnet sectors, each with radial-ridged shape. Maximum magnetic fields are 1.85 T and 0.48 T at hill and valley centers, respectively. The total size of the cyclotron is less than 2 m in diameter. The program TOSCA has been utilized for the field calculation and optimization. In this paper, we describe design parameters of the 13 MeV PET cyclotron, with emphasis on the magnetic field shape and the beam optics calculation. (3 refs).

  17. First commissioning experience with the LINAC4 3 MeV front-end at CERN

    CERN Document Server

    Lallement, J B; Bellodi, G; Comblin, J F; Dimov, V A; Granemann Souza, E; Lettry, J; Lombardi, A M; Midttun, O; Ovalle, E; Raich, U; Roncarolo, F; Rossi, C; Sanchez Alvarez, R; Scrivens, C A; Valerio-Lizarraga, C A; Vretenar, M; Yarmohammadi Satri, M

    2013-01-01

    Linac4 is a normal-conducting 160 MeV H- linear accelerator presently under construction at CERN. It will replace the present 50 MeV Linac2 as injector of the proton accelerator complex as part of a project to increase the LHC luminosity. The Linac front-end, composed of a 45 keV ion source, a Low Energy Beam Transport (LEBT), a 352.2 MHz Radio Frequency Quadrupole (RFQ) and a Medium Energy Beam Transport (MEBT) housing a beam chopper, have been commissioned at the 3 MeV test stand during the first half of 2013. The status of the installation and the results of the first commissioning stage are presented in this paper.

  18. A possible approach to 14MeV neutron moderation: A preliminary study case.

    Science.gov (United States)

    Flammini, D; Pilotti, R; Pietropaolo, A

    2017-07-01

    Deuterium-Tritium (D-T) interactions produce almost monochromatic neutrons with about 14MeV energy. These neutrons are used in benchmark experiments as well as for neutron cross sections assessment in fusion reactors technology. The possibility to moderate 14MeV neutrons for purposes beyond fusion is worth to be studied in relation to projects of intense D-T sources. In this preliminary study, carried out using the MCNP Monte Carlo code, the moderation of 14MeV neutrons is approached foreseeing the use of combination of metallic materials as pre-moderator and reflectors coupled to standard water moderators. Copyright © 2017 Elsevier Ltd. All rights reserved.

  19. Jupiter as a candidate source for >30 MeV electrons in Earth's slot region

    Science.gov (United States)

    O'Brien, T. P., III; Mazur, J. E.; Looper, M. D.

    2016-12-01

    The Relativistic Proton Spectrometer (RPS) on NASA's Van Allen Probes indicates the presence of >30 MeV leptons in the slot region (L 2) near Earth. We investigate the possibility that these are electrons originating at Jupiter. We account for two physical processes inside the radiation belts: inward radial transport that conserves the first and second adiabatic invariants, and synchrotron energy loss as the electrons reach super-relativistic energies (10s MeV). For our boundary condition outside the radiation belts, we use published spectra of Jovian electrons at 1 AU for conditions of good and poor magnetic connection between Earth and Jupiter. We simulate the >30 MeV spectrum and compare it with the RPS data to assess the plausibility of a Jovian source for the super-relativistic leptons in the slot.

  20. Contemporaneous EMIC and whistler mode waves: Observations and consequences for MeV electron loss

    Science.gov (United States)

    Zhang, X.-J.; Mourenas, D.; Artemyev, A. V.; Angelopoulos, V.; Thorne, R. M.

    2017-08-01

    The high variability of relativistic (MeV) electron fluxes in the Earth's radiation belts is partly controlled by loss processes involving resonant interactions with electromagnetic ion cyclotron (EMIC) and whistler mode waves. But as previous statistical models were generated independently for each wave mode, whether simultaneous electron scattering by the two wave types has global importance remains an open question. Using >3 years of simultaneous Van Allen Probes and THEMIS measurements, we explore the contemporaneous presence of EMIC and whistler mode waves in the same L shell, albeit at different local times, determining the distribution of wave and plasma parameters as a function of L, Kp, and AE. We derive electron lifetimes from observations and provide the first statistics of combined effects of EMIC and whistler mode wave scattering on MeV electrons as a function of L and geomagnetic activity. We show that MeV electron lifetimes are often strongly reduced by such combined scattering.

  1. Scalability of the LEU-Modified Cintichem Process: 3-MeV Van de Graaff and 35-MeV Electron Linear Accelerator Studies

    Energy Technology Data Exchange (ETDEWEB)

    Rotsch, David A. [Argonne National Lab. (ANL), Argonne, IL (United States). Nuclear Engineering Division; Brossard, Tom [Argonne National Lab. (ANL), Argonne, IL (United States). Nuclear Engineering Division; Roussin, Ethan [Argonne National Lab. (ANL), Argonne, IL (United States). Nuclear Engineering Division; Quigley, Kevin [Argonne National Lab. (ANL), Argonne, IL (United States). Nuclear Engineering Division; Chemerisov, Sergey [Argonne National Lab. (ANL), Argonne, IL (United States). Nuclear Engineering Division; Gromov, Roman [Argonne National Lab. (ANL), Argonne, IL (United States). Nuclear Engineering Division; Jonah, Charles [Argonne National Lab. (ANL), Argonne, IL (United States). Nuclear Engineering Division; Hafenrichter, Lohman [Argonne National Lab. (ANL), Argonne, IL (United States). Nuclear Engineering Division; Tkac, Peter [Argonne National Lab. (ANL), Argonne, IL (United States). Nuclear Engineering Division; Krebs, John [Argonne National Lab. (ANL), Argonne, IL (United States). Nuclear Engineering Division; Vandegrift, George F. [Argonne National Lab. (ANL), Argonne, IL (United States). Nuclear Engineering Division

    2016-10-31

    Molybdenum-99, the mother of Tc-99m, can be produced from fission of U-235 in nuclear reactors and purified from fission products by the Cintichem process, later modified for low-enriched uranium (LEU) targets. The key step in this process is the precipitation of Mo with α-benzoin oxime (ABO). The stability of this complex to radiation has been examined. Molybdenum-ABO was irradiated with 3 MeV electrons produced by a Van de Graaff generator and 35 MeV electrons produced by a 50 MeV/25 kW electron linear accelerator. Dose equivalents of 1.7–31.2 kCi of Mo-99 were administered to freshly prepared Mo-ABO. Irradiated samples of Mo-ABO were processed according to the LEU Modified-Cintichem process. The Van de Graaff data indicated good radiation stability of the Mo-ABO complex up to ~15 kCi dose equivalents of Mo-99 and nearly complete destruction at doses >24 kCi Mo-99. The linear accelerator data indicate that even at 6.2 kCi of Mo-99 equivalence of dose, the sample lost ~20% of Mo-99. The 20% loss of Mo-99 at this low dose may be attributed to thermal decomposition of the product from the heat deposited in the sample during irradiation.

  2. Energy spectrum measurement of high power and high energy(6 and 9 MeV) pulsed x-ray source for industrial use

    Energy Technology Data Exchange (ETDEWEB)

    Takagi, Hiroyuki [Hitachi, Ltd. Power Systems Company, Ibaraki (Japan); Murata, Isao [Graduate School of Engineering, Osaka University, Osaka (Japan)

    2016-06-15

    Industrial X-ray CT system is normally applied to non-destructive testing (NDT) for industrial product made from metal. Furthermore there are some special CT systems, which have an ability to inspect nuclear fuel assemblies or rocket motors, using high power and high energy (more than 6 MeV) pulsed X-ray source. In these case, pulsed X-ray are produced by the electron linear accelerator, and a huge number of photons with a wide energy spectrum are produced within a very short period. Consequently, it is difficult to measure the X-ray energy spectrum for such accelerator-based X-ray sources using simple spectrometry. Due to this difficulty, unexpected images and artifacts which lead to incorrect density information and dimensions of specimens cannot be avoided in CT images. For getting highly precise CT images, it is important to know the precise energy spectrum of emitted X-rays. In order to realize it we investigated a new approach utilizing the Bayesian estimation method combined with an attenuation curve measurement using step shaped attenuation material. This method was validated by precise measurement of energy spectrum from a 1 MeV electron accelerator. In this study, to extend the applicable X-ray energy range we tried to measure energy spectra of X-ray sources from 6 and 9 MeV linear accelerators by using the recently developed method. In this study, an attenuation curves are measured by using a step-shaped attenuation materials of aluminum and steel individually, and the each X-ray spectrum is reconstructed from the measured attenuation curve by the spectrum type Bayesian estimation method. The obtained result shows good agreement with simulated spectra, and the presently developed technique is adaptable for high energy X-ray source more than 6 MeV.

  3. Astrophysical S factor of the 14N(p ,γ )15O reaction at 0.4-1.3 MeV

    Science.gov (United States)

    Wagner, L.; Akhmadaliev, S.; Anders, M.; Bemmerer, D.; Caciolli, A.; Gohl, St.; Grieger, M.; Junghans, A.; Marta, M.; Munnik, F.; Reinhardt, T. P.; Reinicke, S.; Röder, M.; Schmidt, K.; Schwengner, R.; Serfling, M.; Takács, M. P.; Szücs, T.; Vomiero, A.; Wagner, A.; Zuber, K.

    2018-01-01

    The 14N(p ,γ )15O reaction is the slowest reaction of the carbon-nitrogen cycle of hydrogen burning and thus determines its rate. The precise knowledge of its rate is required to correctly model hydrogen burning in asymptotic giant branch stars. In addition, it is a necessary ingredient for a possible solution of the solar abundance problem by using the solar 13N and 15O neutrino fluxes as probes of the carbon and nitrogen abundances in the solar core. After the downward revision of its cross section due to a much lower contribution by one particular transition, capture to the ground state in 15O, the evaluated total uncertainty is still 8%, in part due to an unsatisfactory knowledge of the excitation function over a wide energy range. The present work reports precise S factor data at twelve energies between 0.357 and 1.292 MeV for the strongest transition, capture to the 6.79-MeV excited state in 15O, and at ten energies between 0.479 and 1.202 MeV for the second strongest transition, capture to the ground state in 15O. An R -matrix fit is performed to estimate the impact of the new data on astrophysical energies. The recently suggested slight enhancement of the 6.79-MeV transition at low energy could not be confirmed. The present extrapolated zero-energy S factors are S6.79(0 ) =1.24 ±0.11 keV b and SGS(0 ) =0.19 ±0.05 keV b.

  4. eta production on carbon and tungsten targets by proton at T sub p<=1500 MeV

    CERN Document Server

    Martins, C D O; Chiavassa, E; Marco, N D; Gallio, M; Musso, A; Piccotti, A; Scomparin, E; Varetto, M; Vercellin, Ermanno

    2001-01-01

    The production of eta meson induced on carbon and tungsten targets by protons of kinetic energies from 800 to 1500 MeV has been studied at the Laboratoire National Saturne at Saclay. eta mesons of mean kinetic energies 55 MeV and 125 MeV have been detected by positioning the PINOT spectrometer in two different configurations. The results are presented and discussed in the framework of a recent theoretical model.

  5. Tests of a Compton imaging prototype in a monoenergetic 4.44 MeV photon field—a benchmark setup for prompt gamma-ray imaging devices

    Science.gov (United States)

    Golnik, C.; Bemmerer, D.; Enghardt, W.; Fiedler, F.; Hueso-González, F.; Pausch, G.; Römer, K.; Rohling, H.; Schöne, S.; Wagner, L.; Kormoll, T.

    2016-06-01

    The finite range of a proton beam in tissue opens new vistas for the delivery of a highly conformal dose distribution in radiotherapy. However, the actual particle range, and therefore the accurate dose deposition, is sensitive to the tissue composition in the proton path. Range uncertainties, resulting from limited knowledge of this tissue composition or positioning errors, are accounted for in the form of safety margins. Thus, the unverified particle range constrains the principle benefit of proton therapy. Detecting prompt γ-rays, a side product of proton-tissue interaction, aims at an on-line and non-invasive monitoring of the particle range, and therefore towards exploiting the potential of proton therapy. Compton imaging of the spatial prompt γ-ray emission is a promising measurement approach. Prompt γ-rays exhibit emission energies of several MeV. Hence, common radioactive sources cannot provide the energy range a prompt γ-ray imaging device must be designed for. In this work a benchmark measurement-setup for the production of a localized, monoenergetic 4.44 MeV γ-ray source is introduced. At the Tandetron accelerator at the HZDR, the proton-capture resonance reaction 15N(p,α γ4.439)12C is utilized. This reaction provides the same nuclear de-excitation (and γ-ray emission) occurrent as an intense prompt γ-ray line in proton therapy. The emission yield is quantitatively described. A two-stage Compton imaging device, dedicated for prompt γ-ray imaging, is tested at the setup exemplarily. Besides successful imaging tests, the detection efficiency of the prototype at 4.44 MeV is derived from the measured data. Combining this efficiency with the emission yield for prompt γ-rays, the number of valid Compton events, induced by γ-rays in the energy region around 4.44 MeV, is estimated for the prototype being implemented in a therapeutic treatment scenario. As a consequence, the detection efficiency turns out to be a key parameter for prompt

  6. The response of the Sievert instrument in neutron beams up to 180 MeV

    CERN Document Server

    Kylionen, J E; Samuelson, G

    2001-01-01

    Measurements with a tissue-equivalent proportional counter (TEPC) using the variance-covariance method have been performed in neutron beams between 71 keV and 180 MeV and in the cosmic radiation reference field (CERF) at CERN. The results show that with appropriate linear Q/sub D/(y/sub D/) relations, the ambient dose equivalent can be determined within about 55% in these beams. Build- up measurements show that wall thickness is not crucial for H* determinations at 60 and 180 MeV. (26 refs).

  7. Effect of 100MeV oxygen ion irradiation on silicon NPN power transistor

    Science.gov (United States)

    Kumar, M. Vinay; Krishnakumar, K. S.; Dinesh, C. M.; Krishnaveni, S.; Ramani

    2012-06-01

    The radiation response of npn Bipolar junction transistor (BJT) has been examined for 100 MeV O7+ ion. Key electrical properties like Gummel characteristics, dc current gain and capacitance-voltage of 100MeV O7+ ion irradiated transistor were studied before and after irradiation. The device was decapped and the electrical characterizations were performed at room temperature. Base current is observed to be more sensitive than collector current and gain appears to be degraded with ion fluence, also considerable degradation in C-V characteristics is observed and doping concentration is found to be increased along with the increase in ion fluence.

  8. Effect of 100MeV oxygen ion irradiation on silicon NPN power transistor

    Energy Technology Data Exchange (ETDEWEB)

    Kumar, M. Vinay; Krishnakumar, K. S.; Dinesh, C. M.; Krishnaveni, S.; Ramani [Department of studies in Physics, University of Mysore, Mysore (India); Department of Physics, APS College, Bengaluru (India); Department of Physics, DCE, Govt. First Grade College, Mangalore (India); Department of studies in Physics, University of Mysore, Mysore (India); Department of Physics, Bangalore University, Bengaluru (India)

    2012-06-05

    The radiation response of npn Bipolar junction transistor (BJT) has been examined for 100 MeV O{sup 7+} ion. Key electrical properties like Gummel characteristics, dc current gain and capacitance-voltage of 100MeV O{sup 7+} ion irradiated transistor were studied before and after irradiation. The device was decapped and the electrical characterizations were performed at room temperature. Base current is observed to be more sensitive than collector current and gain appears to be degraded with ion fluence, also considerable degradation in C-V characteristics is observed and doping concentration is found to be increased along with the increase in ion fluence.

  9. Reactions sup 58,64 Ni( p ,. pi. sup + ) at 201 MeV

    Energy Technology Data Exchange (ETDEWEB)

    Badala, A.; Barbera, R.; Palmeri, A.; Pappalardo, G.S.; Bonasera, A. (Istituto Nazionale di Fisica Nucleare, Corso Italia 57, 95129 Catania (Italy)); Riggi, F.; Adorno, A. (Istituto Nazionale di Fisica Nucleare and Dipartimento di Fisica dell' Universita di Catania, Corso Italia 57, 95129 Catania (Italy)); Bimbot, L. (Institut de Physique Nucleaire, Boite Postale 1, 91406 Orsay CEDEX (France))

    1992-08-01

    The production of positive and negative pions induced by 201 MeV protons on {sup 58}Ni and {sup 64}Ni isotopes has been studied. The double differential cross sections have been measured at the laboratory angles 22{degree}, 35{degree}, 55{degree}, 72{degree}, 90{degree}, 105{degree}, 120{degree}, 138{degree}, 155{degree} and from 20 MeV kinetic energy up to the kinematical limit. Features of the double differential cross sections relative to the two targets are discussed and compared to results obtained at higher incident energies.

  10. Design and experiment of insulation support of 2 MeV injector

    CERN Document Server

    Wang Meng; Dai Guang Sen; Wang Jing Sheng; Xia Lian Sheng; Huang Hai Bo

    2002-01-01

    Aiming at the technical request of high power injector, the authors designed two Nylon radial graded insulation supports on the heads of cathode and anode of the existing 2 MeV injector. The experiment results showed that, on the basis of credible insulation, the supports improved the quality of coaxiality between the cathode and the anode, ameliorated the identity of the three axes of beams, magnetic field and mechanism, and settled the groundwork for advancing each technical performances of the 2 MeV injector

  11. Phase distribution of the 0.44 MeV feature in the Crab pulsar spectrum

    Science.gov (United States)

    Olive, J. F.; Agrinier, B.; Barouch, E.; Comte, R.; Costa, E.; Cusumano, G. C.; Gerardi, G.; Lemoine, D.; Mandrou, P.; Masnou, J. L.; Massaro, E.; Matt, G.; Mineo, T.; Niel, M.; Parlier, B.; Sacco, B.; Salvati, M.; Scarsi, L.

    1993-01-01

    On 1990 July 9, the balloon-borne experiment FIGARO II (0.15-4 MeV) observed the Crab region. The light-curve of PSR 0531 + 212 shows, in addition to the well-known two-peak structures, evidence for extra structures at absolute radio phases 0.1, 0.3, and 0.45 around the energy of 0.44 MeV. The phase-resolved spectroscopy confirms that an excess, compatible with a line-like feature, is present at these phase positions.

  12. Study of elastic pion scattering from /sup 9/Be, /sup 28/Si, /sup 58/Ni, and /sup 208/Pb at 162 MeV. [Total and differential cross sections, scattering yields, scattering amplitudes

    Energy Technology Data Exchange (ETDEWEB)

    Devereux, M.J.

    1979-05-01

    Elastic pion scattering from /sup 9/Be, /sup 28/Si, /sup 58/Ni, and /sup 208/Pb at 162 MeV is analyzed and compared with an optical model theory which incorporates a pion--nucleon range. Excellent fits to the data are obtained in all but one case. The fitted values of the pion--nucleon range, as well as other fitted values are listed. 108 references.

  13. Comparison of Bonner sphere responses calculated by different Monte Carlo codes at energies between 1 MeV and 1 GeV – Potential impact on neutron dosimetry at energies higher than 20 MeV

    CERN Document Server

    Rühm, W; Pioch, C; Agosteo, S; Endo, A; Ferrarini, M; Rakhno, I; Rollet, S; Satoh, D; Vincke, H

    2014-01-01

    Bonner Spheres Spectrometry in its high-energy extended version is an established method to quantify neutrons at a wide energy range from several meV up to more than 1 GeV. In order to allow for quantitative measurements, the responses of the various spheres used in a Bonner Sphere Spectrometer (BSS) are usually simulated by Monte Carlo (MC) codes over the neutron energy range of interest. Because above 20 MeV experimental cross section data are scarce, intra-nuclear cascade (INC) and evaporation models are applied in these MC codes. It was suspected that this lack of data above 20 MeV may translate to differences in simulated BSS response functions depending on the MC code and nuclear models used, which in turn may add to the uncertainty involved in Bonner Sphere Spectrometry, in particular for neutron energies above 20 MeV. In order to investigate this issue in a systematic way, EURADOS (European Radiation Dosimetry Group) initiated an exercise where six groups having experience in neutron transport calcula...

  14. Residual radioactivity at the CERN 600 MeV synchro-cyclotron

    Science.gov (United States)

    Carbonez, P.; La Torre, F. P.; Michaud, R.; Silari, M.

    2012-12-01

    The 600 MeV synchro-cyclotron (SC) was the first accelerator that came into operation at CERN in 1957. It provided beams for CERN's first particle and nuclear physics experiments and operated for 33 years until it was shut down in 1990. In view of a planned partial decommissioning of the facility, a range of measurements were carried out to evaluate the levels of residual radioactivity in the accelerator and its surrounding after about 20 years of cooling time. Gamma spectrometry measurements were performed on 113 samples collected inside the three floors of the accelerator vault, on the cyclotron itself and on concrete samples taken from various parts of the building walls, up to a depth of 50 cm in the shield. About 40% of all samples contain traces of neutron-induced radionuclides, mainly 60Co (in metals), 133Ba, 137Cs, 152Eu and 154Eu (in concrete). Values of specific activities range from 5 mBq/g to 781 Bq/g. The maximum activity induced in concrete was observed at the depth of 40 cm in the wall near the cyclotron extraction channel. The laboratory measurements were supplemented by in-situ gamma spectrometry performed with the ISOCS system. A complete dose rate survey was also performed yielding isodose maps of the three levels of the building. The isotope production and the residual radioactivity in the barite walls of the SC bunker were simulated with the FLUKA and JEREMY codes in use at CERN for predicting residual radioactivity in activated accelerator components, and the results compared with the gamma spectrometry data. A detailed comparison of calculated and measured specific activities shows generally good agreement, to within a factor 2 in most cases. These results serve as indirect validation of the capabilities of these codes to correctly predict residual radioactivity with only a very approximate knowledge of the irradiation profile and after a very long (20 years) cooling time. Overall the results provided in this paper may be of use for

  15. The neutron-deuteron elastic scattering angular distribution at 95 MeV

    Energy Technology Data Exchange (ETDEWEB)

    Mermod, Philippe

    2004-04-01

    The neutron-deuteron elastic scattering differential cross section has been measured at 95 MeV incident neutron energy, with the Medley setup at TSL in Uppsala. The neutron-proton differential cross section has also been measured for normalization purposes. The data are compared with theoretical calculations to investigate the role of three-nucleon force effects.

  16. The 270 MeV deuteron beam polarimeter at the Nuclotron Internal Target Station

    Energy Technology Data Exchange (ETDEWEB)

    Kurilkin, P.K. [Joint Institute for Nuclear Research, Dubna (Russian Federation); Moscow State Institute of Radio-engineering Electronics and Automation (Technical University), Moscow (Russian Federation); Ladygin, V.P., E-mail: vladygin@jinr.ru [Joint Institute for Nuclear Research, Dubna (Russian Federation); Moscow State Institute of Radio-engineering Electronics and Automation (Technical University), Moscow (Russian Federation); Uesaka, T. [Center for Nuclear Study, University of Tokyo, Tokyo 113-0033 (Japan); Suda, K. [RIKEN Nishina Center, Saitama (Japan); Gurchin, Yu.V.; Isupov, A.Yu. [Joint Institute for Nuclear Research, Dubna (Russian Federation); Itoh, K. [Department of Physics, Saitama University, Saitama (Japan); Janek, M. [Joint Institute for Nuclear Research, Dubna (Russian Federation); Physics Department, University of Zilina, 010 26 Zilina (Slovakia); Karachuk, J.-T. [Joint Institute for Nuclear Research, Dubna (Russian Federation); Advanced Research Institute for Electrical Engineering, Bucharest (Romania); Kawabata, T. [Center for Nuclear Study, University of Tokyo, Tokyo 113-0033 (Japan); Khrenov, A.N.; Kiselev, A.S.; Kizka, V.A. [Joint Institute for Nuclear Research, Dubna (Russian Federation); Kliman, J. [Institute of Physics of Slovak Academy of Sciences, Bratislava (Slovakia); Krasnov, V.A.; Livanov, A.N. [Joint Institute for Nuclear Research, Dubna (Russian Federation); Institute for Nuclear Research, Moscow (Russian Federation); Maeda, Y. [Kyushi University, Hakozaki (Japan); Malakhov, A.I. [Joint Institute for Nuclear Research, Dubna (Russian Federation); Matousek, V.; Morhach, M. [Institute of Physics of Slovak Academy of Sciences, Bratislava (Slovakia)

    2011-06-21

    A deuteron beam polarimeter has been constructed at the Internal Target Station at the Nuclotron of JINR. The polarimeter is based on spin-asymmetry measurements in the d-p elastic scattering at large angles and the deuteron kinetic energy of 270 MeV. It allows to measure vector and tensor components of the deuteron beam polarization simultaneously.

  17. Observation of planar oscillations of MeV protons in silicon using ion channeling patterns

    NARCIS (Netherlands)

    Breese, M.B.H.; King, P.J.C.; Grime, G.W.; Smulders, P.J M; Seiberling, L.E.; Boshart, M.A.

    1996-01-01

    This paper describes the observation of {110} planar oscillations of 3 MeV protons transmitted through a 0.5 mu m thick [001] silicon crystal using ion channeling patterns produced on a fluorescent viewing screen. Gradual variations in the crystal thickness allowed the exit angular distribution of

  18. Defect microstructure in copper alloys irradiated with 750 MeV protons

    DEFF Research Database (Denmark)

    Zinkle, S.J.; Horsewell, A.; Singh, B.N.

    1994-01-01

    Transmission electron microscopy (TEM) disks of pure copper and solid solution copper alloys containing 5 at% of Al, Mn, or Ni were irradiated with 750 MeV protons to damage levels between 0.4 and 2 displacements per atom (dpa) at irradiation temperatures between 60 and 200 degrees C. The defect...

  19. The 2-MEV Model: Constancy of Adolescent Environmental Values within an 8-Year Time Frame

    Science.gov (United States)

    Bogner, F. X.; Johnson, B.; Buxner, S.; Felix, L.

    2015-01-01

    The 2-MEV model is a widely used tool to monitor children's environmental perception by scoring individual values. Although the scale's validity has been confirmed repeatedly and independently as well as the scale is in usage within more than two dozen language units all over the world, longitudinal properties still need clarification. The purpose…

  20. Extraction of weak transition strengths via the (He-3, t) reaction at 420 MeV

    NARCIS (Netherlands)

    Zegers, R. G. T.; Adachi, T.; Akimune, H.; Austin, Sam M.; van den Berg, A. M.; Brown, B. A.; Fujita, Y.; Fujiwara, M.; Gales, S.; Guess, C. J.; Harakeh, M. N.; Hashimoto, H.; Hatanaka, K.; Hayami, R.; Hitt, G. W.; Howard, M. E.; Itoh, M.; Kawabata, T.; Kawase, K.; Kinoshita, M.; Matsubara, M.; Nakanishi, K.; Nakayama, S.; Okumura, S.; Ohta, T.; Sakemi, Y.; Shimbara, Y.; Shimizu, Y.; Scholl, C.; Simenel, C.; Tameshige, Y.; Tamii, A.; Uchida, M.; Yamagata, T.; Yosoi, M.

    2007-01-01

    Differential cross sections for transitions of known weak strength were measured with the (He-3, t) reaction at 420 MeV on targets of C-12, C-13, O-18, Mg-26, Ni-58, Ni-60, Zr-90, Sn-118, Sn-120, and Pb-208. Using these data, it is shown that the proportionalities between strengths and cross

  1. Stopping power of aluminium for 5-12 MeV protons and deuterons

    DEFF Research Database (Denmark)

    Andersen, H.H.; Garfinkel, A.F.; Hanke, C.C.

    1966-01-01

    The stopping power of aluminium for 5-12 MeV protons and deuterons has been measured by a thermometric compensation technique working at liquid helium temperature. The experimental method is described and the standard deviation of the results is found to be 0.3%. In order to obtain this accuracy...

  2. Profile and Emittance Measurements at the CERN LINAC4 3 MeV test Stand

    CERN Document Server

    Zocca, F; Duraffourg, M; Focker, GJ; Gerard, D; Raich, U; Roncarolo, F

    2013-01-01

    A new 160 MeV H- Linac named Linac-4 will be built at CERN to replace the old 50 MeV proton Linac. The ion source, the 3 MeV Radio Frequency Quadrupole (RFQ) and the Medium Energy Beam Transport (MEBT) line hosting a chopper, have been commissioned in a dedicated test stand. Wire grids and wire scanners were used to measure the transverse beam profile and a slit/grid emittance meter was installed on a temporary test bench plugged at the RFQ and MEBT exit in different stages. The emittance meter slit was also used as a scanning scraper able to reconstruct the transverse profile by measuring the transmission with a downstream current transformer. On the same measurement bench, a spectrometer in conjunction with a wire grid allowed measuring the energy spread of the particles. This paper summarizes the measurement results that allowed characterizing the 3 MeV beam and discusses the present understanding of monitor performance.

  3. NUSTAR, SWIFT, and GROND Observations of the Flaring MEV Blazar PMN J0641-0320

    DEFF Research Database (Denmark)

    Ajello, M.; Ghisellini, G.; Paliya, V. S.

    2016-01-01

    MeV blazars are a sub-population of the blazar family, exhibiting larger-than-average jet powers, accretion luminosities, and black hole masses. Because of their extremely hard X-ray continua, these objects are best studied in the X-ray domain. Here, we report on the discovery by the Fermi Large...

  4. Design of 7 MeV electron beams for breast radiotherapy

    Energy Technology Data Exchange (ETDEWEB)

    Park, Jon In; Kim, Jung In; Kwon, Hyuck Jun [Interdisplinary Program in Radiation Applied Life Science, Seoul National University Graduate School, Seoul (Korea, Republic of); Ha, Sung Whan; Kim, Il Han [Dept. of Radiation Oncology, Seoul National University College of Medicine, Seoul (Korea, Republic of); Lee, Hyun Suk; Ye, Sung Joon [Program in Biomedical Radiation Sciences, Dept. of Transdisciplinary Studies, Graduate School of Convergence Science and Technology, Seoul National University, Seoul (Korea, Republic of)

    2013-04-15

    For treating early stage breast cancer, breast conserving therapy with lumpectomy followed by radiation therapy has been preferred as the standard method Irradiation technique consists of whole breast irradiation of 50.0 Gy and supplemental boost of 10 Gy to the tumor bed. The 'boost' to supplement the dose to the highest risk breast tissue around the lumpectomy following whole breast irradiation (WBI) improves in-breast local control. Electron beams have been favored radiation as boost irradiation. Because of limited depth in electron beams, it is possible to reduce the dose for unwished organ such as lung and heart in located in deeper region. Traditionally, electron beams can be modified using a bolus. The use of bolus conforms 90% isodose curve of a single energy electron beam to the distal edge of the target volume. However, it often increases the skin dose with electron beams of energy below 10 MeV. Therefore, with an aim to simultaneously control the penetration depth of the electron beams and the skin dose, we produced the new 7 MeV electron beam by modulating 9 MeV electron beams available in clinical linear accelerators. In this study, we show that the 7 MeV electron beam is appropriate for treatment of patient with a tumor bed located in clinical depth (R90 – R80)

  5. Polarization observables for the reaction pp-->ppπ0 at 800 MeV

    Science.gov (United States)

    Riley, P. J.; Bachman, Mark; Hollas, C. L.; McNaughton, K. H.; Shen-Wu, Xu; Bonner, B. E.; van Dyck, O. B.; McGill, J.; McNaughton, M. W.; Peng, J. C.; Silbar, R. R.; Dubach, J.; Kloet, W. M.

    1987-10-01

    The Wolfenstein polarization observables DNN, DSΩ and DLΩ, where Ω denotes a mixture of S and L polarization components, the induced polarization P, and the analysing power A have been measured for the reaction pp-->ppπ0 at 800, 733, and 647 MeV. Comparisons are made to theoretical predictions of the model of Dubach, Kloet and Silbar.

  6. Preliminary design studies of a 100 MeV H-/H+LINAC as injector for ...

    Indian Academy of Sciences (India)

    Preliminary design studies of a 100 MeV H-/H+LINAC as injector for SNS synchrotron/ADS LINAC. S A PANDE, MOONOOKU PRASAD, NITA KULKARNI and P R HANNURKAR. Centre for Advanced Technology, Indore 452 013, India. Abstract. It is proposed to construct a spallation neutron source (SNS) at Centre for ...

  7. CERN Linac4 Beam Dynamics Studies and Commissioning up to 12 MeV

    CERN Document Server

    Yildiz, Veli; Dimov, Veliko Atanasov; Ozcan, Erkcan; Arik, Metin

    Linac4 is a normal conducting, 160 MeV H ions accelerator that is being constructed within the scope of the LHC Injectors Upgrade project. Linac4 will be connected to the Proton Synchrotron Booster during the next long LHC shutdown and it will replace the current 50 MeV proton linac, Linac2. Linac4 is being commissioned progressively with the installation of the accelerating structures into the Linac4 tunnel. Movable diagnostic benches, with various instruments, are used at each step to allow the detailed characterization of operational parameters that will play a key role in the overall future performance. The rst three stages of the commissioning, up to 12 MeV beam energy, were completed by the end of 2014 with a temporary version of the ion source. Using the permanent diagnostic instruments and a movable diagnostic bench, the Low Energy Beam Transport (LEBT) at 45 keV, the Radio Frequency Quadrupole (RFQ) and Medium Energy Beam Transport (MEBT) at 3 MeV, as well as the rst tank of the Drift Tube Linac ...

  8. Review of RBE values of 15 MeV neutrons for effects on normal tissues

    NARCIS (Netherlands)

    Broerse, J.J.

    1974-01-01

    Values of the relative biological effectiveness (RBE) of fast neutrons for effect on normal tissue depend not only on the neutron energy and the dose, but also on the type of tissue irradiated. Values of the RBE of 15 MeV neutrons are reviewed for rapidly proliferating rodent tissue, such as mouse

  9. Three-dimensional simulation studies of 10 MeV, 352.2 MHz drift ...

    Indian Academy of Sciences (India)

    Three-dimensional simulation studies of 10 MeV,. 352.2 MHz drift tube Linac. NITA S KULKARNI ... This paper presents the details of the studies and analysis of 3D simulations of post-couplers, .... stabilize the accelerating field in case of local field errors by creating a secondary coupled resonator system which is coupled to ...

  10. Physical and chemical response of 70 MeV carbon ion irradiated ...

    Indian Academy of Sciences (India)

    Home; Journals; Bulletin of Materials Science; Volume 24; Issue 5 ... Kapton-H polymer; carbon ions; radiation effects; UV and FT-IR spectroscopy; X-ray diffraction. Abstract. Physical and chemical responses of 70 MeV carbon ion irradiated Kapton-H polymer were studied by using UV-visible, FTIR and XRD techniques.

  11. The pilot experimental study of 14 MeV fast neutron digital radiography

    Science.gov (United States)

    Tang, Bin; Zhou, Changgen; Huo, Heyong; Wu, Yang; Liu, Bin; Lou, Benchao; Sun, Yong

    2009-09-01

    14 MeV Fast neutrons has good penetrability and the 14 MeV fast neutron radiography can meet the need of Non-Destructive Test of the structure and lacuna of heavy-massive sample, whose shell is made of heavy metal and in which there are some hydrogen materials, and the study of fast neutron digital radiography just begins in China. By the use of a D-T accelerator, a digital imaging system made up of a fast neutron scintillation screen made of ZnS(Ag) and polypropylene, lens and a scientific grade CCD, the experimental study of fast neutron radiography has been done between 4.3×1010-6.8×1010 n/s of neutron yield. Some 14 MeV fast neutron digital radiographs have been gotten. According to experimental radiographs and their data, the performance of the fast neutron scintillation screen and the basic characters of 14 MeV fast neutron radiography are analyzed, and it is helpful for the further research.

  12. Cross sections for the /sup 14/N(n,p/sub 0/), (n,. cap alpha. /sub 0/), and (n,. cap alpha. /sub 1/) reactions from 0. 5 to 15 MeV. [0. 5 to 15 MeV

    Energy Technology Data Exchange (ETDEWEB)

    Morgan, G.L.

    1978-09-01

    Cross sections were measured for the /sup 14/N(n,p/sub 0/) reaction from 0.5 to 7.0 MeV and for the (n,..cap alpha../sub 0/) and (n,..cap alpha../sub 1/) reactions from 1 to 15 MeV and 4 to 15 MeV, respectively. The data were obtained using a gaseous scintillator containing N/sub 2/ and Xe mixtures. A linac was used as a pulsed, white neutron source with a 29-m fight path. The results of the measurement are compared to the current evaluated file for nitrogen; agreement is good for neutron energies below 8 MeV, but the measurement is substantially higher than the evaluation for neutron energies near 10 MeV.

  13. 25 MeV solar proton events in Cycle 24 and previous cycles

    Science.gov (United States)

    Richardson, Ian G.; von Rosenvinge, Tycho T.; Cane, Hilary V.

    2017-08-01

    We summarize observations of around a thousand solar energetic particle (SEP) events since 1967 that include ∼25 MeV protons, made by various near-Earth spacecraft (IMPs 4, 5, 7, 8, ISEE 3, SOHO), that encompass Solar Cycle 20 to the current cycle (24). We also discuss recent observations of similar SEP events in Cycle 24 made by the STEREO spacecraft. The observations show, for example, that the time distribution of ∼25 MeV proton events varies from cycle to cycle. In particular, the time evolution of the SEP occurrence rate in Cycle 24 is strongly asymmetric between the northern and southern solar hemispheres, and tracks the sunspot number in each hemisphere, whereas Cycle 23 was more symmetric. There was also an absence of 25 MeV proton events during the solar minimum preceding Cycle 24 (other minima show occasional, often reasonably intense events). So far, events comparable to the exceptionally intense events detected in Cycles 22 and 23 have not been observed at Earth in Cycle 24, though Cycle 21 (the largest of the cycles considered here) also apparently lacked such events. We note a correlation between the rates of intense 25 MeV proton events and ;ground level enhancements; (GLEs) observed by neutron monitors, since 1967, and conclude that the number of ;official; GLEs (1) observed to date in Cycle 24 appears to be significantly lower than expected (5 to 7 ± 1) based on the rate of intense 25 MeV proton events in this cycle.

  14. 1000 MeV Proton beam therapy facility at Petersburg Nuclear Physics Institute Synchrocyclotron

    Energy Technology Data Exchange (ETDEWEB)

    Abrosimov, N K [Petersburg Nuclear Physics Institute, 188300 Gatchina (Russian Federation); Gavrikov, Yu A [Petersburg Nuclear Physics Institute, 188300 Gatchina (Russian Federation); Ivanov, E M [Petersburg Nuclear Physics Institute, 188300 Gatchina (Russian Federation); Karlin, D L [Central Research Institute of Roentgenology and Radiology, 197758, St.Petersburg (Russian Federation); Khanzadeev, A V [Petersburg Nuclear Physics Institute, 188300 Gatchina (Russian Federation); Yalynych, N N [Central Research Institute of Roentgenology and Radiology, 197758, St. Petersburg (Russian Federation); Riabov, G A [Petersburg Nuclear Physics Institute, 188300 Gatchina (Russian Federation); Seliverstov, D M [Petersburg Nuclear Physics Institute, 188300 Gatchina (Russian Federation); Vinogradov, V M [Central Research Institute of Roentgenology and Radiology, 197758, St.Petersburg (Russian Federation)

    2006-05-15

    Since 1975 proton beam of PNPI synchrocyclotron with fixed energy of 1000 MeV is used for the stereotaxic proton therapy of different head brain diseases. 1300 patients have been treated during this time. The advantage of high energy beam (1000 MeV) is low scattering of protons in the irradiated tissue. This factor allows to form the dose field with high edge gradients (20%/mm) that is especially important for the irradiation of the intra-cranium targets placed in immediate proximity to the life critical parts of the brain. Fixation of the 6 0mm diameter proton beam at the isodose centre with accuracy of {+-}1.0 mm, two-dimensional rotation technique of the irradiation provide a very high ratio of the dose in the irradiation zone to the dose at the object's surface equal to 200:1. The absorbed doses are: 120-150 Gy for normal hypophysis, 100-120 Gy for pituitary adenomas and 40-70 Gy for arterio-venous malformation at the rate of absorbed dose up to 50 Gy/min. In the paper the dynamics and the efficiency of 1000 MeV proton therapy treatment of the brain deceases are given. At present time the feasibility study is in progress with the goal to create a proton therapy on Bragg peak by means of the moderation of 1000 MeV proton beam in the absorber down to 200 MeV, energy required for radiotherapy of deep seated tumors.

  15. A Monte Carlo computer code for evaluating energy loss of 10 keV to 10 MeV ions in amorphous silicon materials

    Energy Technology Data Exchange (ETDEWEB)

    Erramli, H. [Nuclear Physics and Techniques Laboratory, Faculty of Sciences Semlalia, BP 2390, University Cadi Ayyad, Marrakech (Morocco)], E-mail: hassane@ucam.ac.ma; Elbounagui, O.; Misdaq, M.A. [Nuclear Physics and Techniques Laboratory, Faculty of Sciences Semlalia, BP 2390, University Cadi Ayyad, Marrakech (Morocco); Merzouki, A. [Nuclear Physics and Techniques Laboratory, Faculty of Sciences Semlalia, BP 2390, University Cadi Ayyad, Marrakech (Morocco); Remote Sensing and Geomatics of the Environment Laboratory, Ottawa-Carleton Geoscience Centre, Marion Hall, 140 Louis Pasteur, Ottawa, ON, KIN6N5 (Canada)

    2007-10-15

    The basic concepts of a computer simulation code for determining the energy loss of ions in the 10 keV to 10 MeV energy range in amorphous silicon materials were presented and discussed. Data obtained were found in good agreement with those obtained by using a SRIM programme. Electronic and nuclear energy losses were evaluated. Variation of the energy loss as a function of the incident ion energy were studied. This new computer code is a good tool for evaluating stopping powers of various materials for light and heavy ions.

  16. Comparison of the (p,xn) cross sections from /sup 238/U, /sup 235/U, and /sup 232/Th targets irradiated with 200-MeV protons

    Energy Technology Data Exchange (ETDEWEB)

    Chu, Y.Y.; Zhou, M.L.

    1982-01-01

    We have measured absolute cross sections for (p,xn) reactions (x ranges from 0 to 8) from /sup 238/U, /sup 235/U, and /sup 232/Th targets irradiated with 200-MeV protons at the Brookhaven AGS Linac injector. Chemical yields were determined by using /sup 239/Np and /sup 233/Pa as tracers. Yield patterns obtained in this work can be compared to the experimental results and theoretical calculations from earlier work, and they are consistent within the framework of intranuclear cascade followed by neutron evaporation and fission competition.

  17. H(t Vector,t)H scattering at low energies. [Differential cross sections, vector analyzing powers, 1. 26 to 3. 71 MeV cm

    Energy Technology Data Exchange (ETDEWEB)

    Haglund, R.F. Jr.; Fick, D.; Schmelzbach, P.A.; Ohlsen, G.G.; Jarmie, N.; Brown, R.E.

    1977-03-01

    Angular distributions of the differential cross section and vector analyzing power for H + t approaches elastic scattering, at center-of-mass energies 1.26, 1.68, 2.19, 2.70, 3.21, and 3.71 MeV are presented. A preliminary phase-shift analysis of the data confirms the importance of the odd-parity tensor and even-parity spin-orbit nucleon-nucleon forces in model calculations for the /sup 4/He system in this energy range.

  18. Measurement of the neutron-induced fission cross-section of {sup 243}Am relative to {sup 235}U from 0.5 to 20 MeV

    Energy Technology Data Exchange (ETDEWEB)

    Belloni, F.; Milazzo, P.M.; Abbondanno, U.; Fujii, K.; Moreau, C. [Istituto Nazionale di Fisica Nucleare, Trieste (Italy); Calviani, M. [Laboratori Nazionali di Legnaro, Istituto Nazionale di Fisica Nucleare, Legnaro (Italy); CERN, Geneva (Switzerland); Colonna, N.; Barbagallo, M.; Marrone, S.; Meaze, M.H.; Tagliente, G.; Terlizzi, R. [Istituto Nazionale di Fisica Nucleare, Bari (Italy); Mastinu, P.; Gramegna, F. [Lab. Nazionali di Legnaro, Istituto Nazionale di Fisica Nucleare, Legnaro (Italy); Aerts, G.; Andriamonje, S.; Berthoumieux, E.; Dridi, W.; Gunsing, F.; Pancin, J.; Perrot, L.; Plukis, A. [Irfu, CEA, Gif-sur-Yvette (France); Alvarez, H.; Cano-Ott, D.; Duran, I.; Embid-Segura, M.; Gonzalez-Romero, E.; Paradela, C.; Tarrio, D. [Univ. de Santiago de Compostela, Galicia (Spain); Alvarez-Velarde, F.; Guerrero, C.; Martinez, T.; Villamarin, D.; Vincente, M.C. [Centro de Investigaciones Energeticas Medioambientales y Technologicas, Madrid (Spain); Andrzejewski, J.; Marganiec, J. [Univ. of Lodz (Poland); Audouin, L.; Dillmann, I.; Heil, M.; Kaeppeler, F.; Mosconi, M.; Plag, R.; Voss, F.; Walter, S.; Wisshak, K. [Karlsruhe Inst. of Technology, Eggenstein-Leopoldshafen (Germany). Inst. fuer Kernphysik; Badurek, G.; Jericha, E.; Leeb, H.; Oberhummer, H. [Technische Univ. Wien, Atominstitut der Oesterreichischen Universitaeten, Wien (Austria); Baumann, P.; David, S.; Kerveno, M.; Lukic, S.; Rudolf, G. [IReS, Centre National de la Recherche Scientifique/IN2P3, Strasbourg (France); Becvar, F.; Krticka, M. [Charles Univ., Faculty of Mathematics and Physics, Prague (Czech Republic); Calvino, F.; Cortes, G.; Poch, A.; Pretel, C. [Univ. Politecnica de Catalunya, Barcelona (Spain); Capote, R. [NAPC/Nuclear Data Section, International Atomic Energy Agency, Vienna (Austria); Univ. de Sevilla (Spain); Carrapico, C.; Goncalves, I.; Salgado, J.; Santos, C.; Tavora, L.; Vaz, P. [Inst. Tecnologico e Nuclear, Lisbon (Portugal)] [and others

    2011-12-15

    The ratio of the neutron-induced fission cross-sections of {sup 243}Am and {sup 235}U was measured in the energy range from 0.5 to 20 MeV with uncertainties of {approx} 4%. The experiment was performed at the CERN n{sub T}OF facility using a fast ionization chamber. With the good counting statistics that could be achieved thanks to the high instantaneous flux and the low backgrounds, the present results are useful for resolving discrepancies in previous data sets and are important for future reactors with improved fuel burn-up. (orig.)

  19. First results on the 32S+40, 48Ca reactions at 17.7A MeV studied with GARFIELD setup at LNL

    Science.gov (United States)

    Piantelli, S.; Valdré, S.; Barlini, S.; Casini, G.; Colonna, M.; Baiocco, G.; Bini, M.; Bruno, M.; Camaiani, A.; Cicerchia, M.; Cinausero, M.; D'Agostino, M.; Degerlier, M.; Fabris, D.; Gramegna, F.; Kravchuck, V. L.; Mabiala, J.; Marchi, T.; Morelli, L.; Olmi, A.; Ottanelli, P.; Pasquali, G.; Pastore, G.

    2017-11-01

    The ^{32} S+ ^{40,48} Ca systems at 17A MeV have been characterized both for fusion and for peripheral events thanks to the GARFIELD setup, which covers a wide angular range and has high granularity; moreover, isotopic identification for forward emitted ions up to Z around 15 is obtained. The main evidences reported here concern pre-equilibrium emission, which was put into evidence in fusion-evaporation events, and isospin diffusion observed studying the average N/ Z of the Quasi-Projectile as a function of the target isospin.

  20. Study of beam dynamics on high current 3.5 MeV RFQ for China ADS

    CERN Document Server

    Guan Xia Ling; Fu Shin Ian

    2003-01-01

    A 3.5 MeV RFQ accelerator for the China accelerator driven sub-critical reactor system (ADS) is currently under construction at IHEP, which is a 75 keV/3.5 MeV, 352.2 MHz, 50 mA, four vanes type of RFQ. The characteristics, principle and results of the dynamics are described

  1. Single Particle Strengths and Mirror States in $^{15}$N$-^{15}$O below 12.0 MeV

    CERN Document Server

    Mertin, C E; Crisp, A M; Keeley, N; Kemper, K W; Momtyuk, O; Roeder, B T; Volya, A

    2014-01-01

    New $^{14}$N(d,p) angular distribution data were taken at a deuteron bombarding energy of 16 MeV to locate all narrow single particle neutron states up to 15 MeV in excitation. A new shell model calculation is able to reproduce all levels in $^{15}$N up to 11.5 MeV and is used to characterize a narrow single particle level at 11.236 MeV and to provide a map of the single particle strengths. The known levels in $^{15}$N are then used to determine their mirrors in the lesser known nucleus $^{15}$O. The 2s$_{1/2}$ and 1d$_{5/2}$ single particle centroid energies are determined for the $^{15}$N$-^{15}$O mirror pair as: $^{15}$N $(\\text{2s}_{1/2}) = 8.08$ MeV, $^{15}$O $(\\text{2s}_{1/2}) = 7.43$ MeV, $^{15}$N $(\\text{1d}_{5/2}) = 7.97$ MeV, and $^{15}$O $(\\text{1d}_{5/2}) = 7.47$ MeV. These results confirm the degeneracy of these orbits and that the $^{15}$N$-^{15}$O nuclei are where the transition between the $\\text{2s}_{1/2}$ lying below the $\\text{1d}_{5/2}$ to lying above it, takes place. The $\\text{1d}_{3/2}$...

  2. Dosimetric characterization of a synthetic single crystal diamond detector in a clinical 62 MeV ocular therapy proton beam

    Energy Technology Data Exchange (ETDEWEB)

    Marinelli, Marco; Pompili, F. [INFN-Dipartimento di Ingegneria Industriale, Università di Roma “Tor Vergata”, Via del Politecnico 1, I-00133 Roma (Italy); Prestopino, G., E-mail: giuseppe.prestopino@uniroma2.it [INFN-Dipartimento di Ingegneria Industriale, Università di Roma “Tor Vergata”, Via del Politecnico 1, I-00133 Roma (Italy); Verona, C.; Verona-Rinati, G. [INFN-Dipartimento di Ingegneria Industriale, Università di Roma “Tor Vergata”, Via del Politecnico 1, I-00133 Roma (Italy); Cirrone, G.A.P.; Cuttone, G.; La Rosa, R.M.; Raffaele, L.; Romano, F. [Laboratori Nazionali del SUD, INFN, Catania (Italy); Tuvè, C. [INFN Sezione di Catania and Dipartimento di Fisica e Astronomia, Università di Catania, Catania (Italy)

    2014-12-11

    A synthetic single crystal diamond based Schottky photodiode was tested at INFN-LNS on the proton beam line (62 MeV) dedicated to the radiation treatment of ocular disease. The diamond detector response was studied in terms of pre-irradiation dose, linearity with dose and dose rate, and angular dependence. Depth dose curves were measured for the 62 MeV pristine proton beam and for three unmodulated range-shifted proton beams; furthermore, the spread-out Bragg peak was measured for a modulated therapeutic proton beam. Beam parameters, recommended by the ICRU report 78, were evaluated to analyze depth-dose curves from diamond detector. Measured dose distributions were compared with the corresponding dose distributions acquired with reference plane-parallel ionization chambers. Field size dependence of the output factor (dose per monitor unit) in a therapeutic modulated proton beam was measured with the diamond detector over the range of ocular proton therapy collimator diameters (5–30 mm). Output factors measured with the diamond detector were compared to the ones by a Markus ionization chamber, a Scanditronix Hi-p Si stereotactic diode and a radiochromic EBT2 film. Signal stability within 0.5% was demonstrated for the diamond detector with no need of any pre-irradiation dose. Dose and dose rate dependence of the diamond response was measured: deviations from linearity resulted to be within ±0.5% over the investigated ranges of 0.5–40.0 Gy and 0.3–30.0 Gy/min respectively. Output factors from diamond detector measured with the smallest collimator (5 mm in diameter) showed a maximum deviation of about 3% with respect to the high resolution radiochromic EBT2 film. Depth-dose curves measured by diamond for unmodulated and modulated beams were in good agreement with those from the reference plane-parallel Markus chamber, with relative differences lower than ±1% in peak-to-plateau ratios, well within experimental uncertainties. A 2.5% variation in diamond detector

  3. The 13C(n,α0)10Be cross section at 14.3 MeV and 17 MeV neutron energy

    Science.gov (United States)

    Kavrigin, P.; Belloni, F.; Frais-Koelbl, H.; Griesmayer, E.; Plompen, A. J. M.; Schillebeeckx, P.; Weiss, C.

    2017-09-01

    At nuclear fusion reactors, CVD diamond detectors are considered an advantageous solution for neutron flux monitoring. For such applications the knowledge of the cross section of neutron-induced nuclear reactions on natural carbon are of high importance. Especially the (n,α0) reactions, yielding the highest energy reaction products, are of relevance as they can be clearly distinguished in the spectrum. The 13C(n,α0)10Be cross section was measured relative to 12C(n,α0)9Be at the Van de Graaff facility of EC-JRC Geel, Belgium, at 14.3 MeV and 17.0 MeV neutron energies. The measurement was performed with an sCVD (single-crystal Chemical Vapor Deposition) diamond detector, where the detector material acted simultaneously as sample and as sensor. A novel data analysis technique, based on pulse-shape discrimination, allowed an efficient reduction of background events. The results of the measurement are presented and compared to previously published values for this cross-section.

  4. Elastic and inelastic scattering of {sup 14}N ions by {sup 7}Li at 80 MeV (c.m. 26.7 MeV)

    Energy Technology Data Exchange (ETDEWEB)

    Rudchik, A.T.; Herashchenko, O.V.; Rudchik, A.A.; Mezhevych, S.Yu.; Mokhnach, A.V.; Pirnak, V.M.; Ponkratenko, O.A.; Ilyin, A.P.; Uleshchenko, V.V. [Institute for Nuclear Research, Kyiv (Ukraine); Kemper, K.W. [Florida State University, Physics Department, Tallahassee, Florida (United States); Rusek, K. [National Institute for Nuclear Research, Warsaw (Poland); Heavy Ion Laboratory of Warsaw University, Warsaw (Poland); Koshchy, E.I. [Kharkiv National University, Kharkiv (Ukraine); Kliczewski, S.; Siudak, R.; Szczurek, A. [H. Niewodniczanski Institute of Nuclear Physics, Cracow (Poland); Plujko, V.A. [Taras Shevchenko Kyiv National University, Kyiv (Ukraine); Choinski, J. [Heavy Ion Laboratory of Warsaw University, Warsaw (Poland); Stolarz, A. [National Institute for Nuclear Research, Warsaw (Poland)

    2014-10-15

    New angular distribution data for {sup 7}Li + {sup 14}N elastic and inelastic scattering at the energy E{sub lab} ({sup 14}N) = 80 MeV (c.m. 26.7MeV) are presented. The data were analyzed within the optical model and the coupled-reaction-channels method using a channels-coupling scheme that included the {sup 7}Li and {sup 14}N inelastic scattering channels, spin reorientations of {sup 7}Li and {sup 14}N as well as most important transfer reactions. The low-energy excited states of {sup 7}Li and {sup 14}N were assumed to be collective in nature. The {sup 7}Li + {sup 14}N potential parameters as well as deformation parameters of {sup 7}Li and {sup 14}N were deduced. The {sup 7}Li + {sup 14}N potential and the data were compared with those of {sup 6}Li + {sup 14}N to observe isotopic differences. The enhanced large-angle elastic and inelastic scattering data are shown to have a large contribution from the ground-state reorientation of {sup 7}Li. (orig.)

  5. Comparison of neutron fluxes in an 18-MeV unshielded cyclotron room and a 16.5-MeV self-shielded cyclotron room.

    Science.gov (United States)

    Fujibuchi, Toshioh; Horitsugi, Genki; Yamaguchi, Ichiro; Eto, Akihisa; Iwamoto, Yasuo; Obara, Satoshi; Iimori, Takashi; Masuda, Yoshitada; Watanabe, Hiroshi; Hatazawa, Jun

    2012-07-01

    Some medical compact cyclotrons have self-shielding to reduce neutron fluxes. Thermal neutron fluxes in an 18-MeV unshielded cyclotron room and in a 16.5-MeV self-shielded cyclotron room were evaluated. In addition, the radioactivities in concrete and metals due to thermal neutrons in the cyclotron rooms for 30 years were calculated of operation such that the sum of the ratio of the nuclide concentration to the nuclide clearance level was equal to 1. The thermal neutron flux from the unshielded cyclotron was approximately 10(2) cm(-2) s(-1), whereas that from the self-shielded cyclotron was approximately 10(2) cm(-2) s(-1). The thermal neutron fluxes for concrete, stainless steel, vessel steel, and aluminum that reached their clearance levels were 9.80 × 10(4), 2.17 × 10(3), 1.87 × 10(4), and 2.41 × 10(5) cm(-2) s(-1), respectively. The specific activities in the cyclotron room were found to be sufficiently below the clearance level when the self-shield was employed.

  6. Displacement cross sections and PKA spectra: tables and applications. [Neutron damage energy cross sections to 20 MeV, primary knockon atom spectra to 15 MeV

    Energy Technology Data Exchange (ETDEWEB)

    Doran, D G; Graves, N J

    1976-12-01

    Damage energy cross sections to 20 MeV are given for aluminum, vanadium, chromium, iron, nickel, copper, zirconium, niobium, molybdenum, tantalum, tungsten, lead, and 18Cr10Ni stainless steel. They are based on ENDF/B-IV nuclear data and the Lindhard energy partition model. Primary knockon atom (PKA) spectra are given for aluminum, iron, niobium, tantalum, and lead for neutron energies up to 15 MeV at approximately one-quarter lethargy intervals. The contributions of various reactions to both the displacement cross sections (taken to be proportional to the damage energy cross sections) and the PKA spectra are presented graphically. Spectral-averaged values of the displacement cross sections are given for several spectra, including approximate maps for the Experimental Breeder Reactor-II (EBR-II) and several positions in the Fast Test Reactor (FTR). Flux values are included to permit estimation of displacement rates. Graphs show integral PKA spectra for the five metals listed above for neutron spectra corresponding to locations in the EBR-II, the High Flux Isotope Reactor (HFIR), and a conceptual fusion reactor (UWMAK-I). Detailed calculations are given only for cases not previously documented. Uncertainty estimates are included.

  7. Quantitative Assessment of MeV Electron Acceleration in Non-Linear Interactions with VLF Chorus

    Science.gov (United States)

    Foster, J. C.; Erickson, P. J.; Omura, Y.; Baker, D. N.

    2016-12-01

    For occurrences of apparent rapid acceleration of radiation belt electrons to MeV energies at L 4, we examine the energy gained by seed electrons in non-linear (NL) interactions with VLF chorus rising tones. For the 17-18 March 2013 storm, observations of outer zone radiation belt electron populations were made with the magEIS and REPT instruments on Van Allen Probes A & B. These reveal that MeV electron fluxes at L=4.2 increased 10-fold in 30 min at the times of 30 - 100 keV electron injections during "substorm" dipolarizations. Simultaneous enhancements of VLF chorus were observed with the EMFISIS wave instruments. Three-axis burst mode observations of wave electric and magnetic fields have been used to investigate electron interactions with individual chorus rising tones on a sub millisecond time scale. Wave amplitudes at 2500 Hz were 1 nT (|B|) and 30 mV/m (|E|). Frequency - time characteristics of the observed chorus elements closely match those predicted by NL electron-chorus interaction modeling [Omura et al., 2015, J. Geophys. Res. Space Phys., 120, doi:10.1002/2015JA021563]. For seed electrons with initial energies 50 keV to 8 MeV, subpacket wave analysis was used to quantify resonant electron energy gain both by relativistic turning acceleration and by ultrarelativistic acceleration through nonlinear trapping by the chorus waves. Electrons with 1-2 MeV initial energy can experience a 300 keV total energy gain in NL interactions with a single 200 msec rising tone. Maximum energy gain from interaction with a single 10 msec subpacket was 100 keV for a 2 MeV seed electron. Examining a number of chorus elements at different locations during the rapid local acceleration of the radiation belt during this event, we conclude that seed electrons (100s keV - 5 MeV) can be accelerated by 50 keV - 500 keV in resonant NL interactions with a single VLF rising tone on a time scale of 10-100 msec.

  8. Multi-step processes in the (d, t) and (d, {sup 3}He) reactions on {sup 116}Sn and {sup 208}Pb targets at E{sub d} = 200 MeV

    Energy Technology Data Exchange (ETDEWEB)

    Langevin-Joliot, H.; Van de Wiele, J.; Guillot, J. [Institut de Physique Nucleaire, IN2P3/CNRS, 91 - Orsay (France); Koning, A.J. [Nuclear Research and Consultancy Group NRG, NL (Netherlands)

    2000-07-01

    The role of multi-step processes in the reactions {sup 116}Sn(d,t), {sup 208}Pb(d,t) and {sup 116}Sn(d,{sup 3}He), previously studied at E{sub d} = 200 MeV at forward angles and for relatively low energy transfers, has been investigated. We have performed for the first time multi-step calculations taking into account systematically collective excitations in the second and higher order step inelastic transitions. A calculation code based on the Feshbach, Kerman and Koonin model has been modified to handle explicitly these collective excitations, most important in the forward angle domain. One step double differential pick-up cross sections were built from finite range distorted wave results spread in energy using known or estimated hole state characteristics. It is shown that two-step cross sections calculated using the above method compare rather well with those deduced via coupled channel calculations for the same collective excitations. The multi-step calculations performed up to 6 steps reproduce reasonably well the {sup 115}Sn, {sup 207}Pb and {sup 115}In experimental spectra measured up to E{sub x}{approx}- 40 MeV and 15 deg. The relative contributions of steps of increasing order to pick-up cross sections at E{sub d} = 200 MeV and 150 MeV are discussed. (authors)

  9. Effect of 50 MeV Li 3+ ion irradiation on electrical characteristics of high speed NPN power transistor

    Science.gov (United States)

    Dinesh, C. M.; Ramani; Radhakrishna, M. C.; Dutt, R. N.; Khan, S. A.; Kanjilal, D.

    2008-04-01

    Silicon NPN overlay RF power high speed commercial bipolar junction transistors (BJTs) find applications in military, space and communication equipments. Here we report the effect of 50 MeV Li3+ ion irradiation in the fluence range 1 × 1011-1.8 × 1012 ions cm-2 on NPN power transistor. The range (R), electronic energy loss (Se), nuclear energy loss (Sn), total ionizing dose (TID) and total displacement damage (Dd) in the silicon target are calculated from TRIM Monte Carlo Code. Output resistance is 3.568 × 104 Ω for unirradiated device and it increases to 6 × 107 Ω as the fluence is increased from 1 × 1011 to 1.8 × 1012 ions cm-2. The capacitance of the emitter-base junction of the transistor decreases and dielectric loss of the emitter-base junction increases with increase in ion fluence. The built in voltage of the unirradiated sample is 0.5 V and it shifts to 0.4 V after irradiation at fluence of 1.8 × 1012 ions cm-2 and the corresponding doping density reduced to 5.758 × 1016 cm-3. The charge carrier removal rate varies linearly with the increase in ion fluence.

  10. New excitation functions for proton induced reactions on natural titanium, nickel and copper up to 70 MeV

    Science.gov (United States)

    Garrido, E.; Duchemin, C.; Guertin, A.; Haddad, F.; Michel, N.; Métivier, V.

    2016-09-01

    New excitation functions for proton induced nuclear reactions on natural titanium, nickel and copper were measured, using the stacked-foil technique and gamma spectrometry, up to 70 MeV. The experimental cross sections were measured using the Ti-nat(p,x) V-48, Ni-nat(p,x) Ni-57 and Cu-nat(p,x) Zn-62,Co-56 monitor reactions recommended by the International Atomic Energy Agency (IAEA), depending on the investigated energy range. Data have been extracted for the Ti-nat(p,x) Sc-43,44m,46,47,48, V-48, K-42,43, Ni-nat(p,x) Ni-56,57, Co-55,56,57,58, Mn-52,54, Cu-nat(p,x) Cu-61,64, Ni-57, Co-56,57,58,60, Zn-62,65, Mn-54 reactions. Our results are discussed and compared to the existing ones as well as with the TALYS code version 1.6 calculations using default models. Our experimental data are in overall good agreement with the literature. TALYS is able to reproduce, in most cases, the experimental trend. Our new experimental results allow to expand our knowledge on these excitation functions, to confirm the existing trends and to give additional values on a large energy range. This work is in line with the new Coordinated Research Project (CRP) launched by the IAEA to expand the database of monitor reactions.

  11. e/sup +/e/sup -/ annihilation into two hadrons in the energy interval 1400-2400 MeV

    CERN Document Server

    Alles-Borelli, V; Bollini, D; Brunini, P L; Fiorentino, E; Massam, Thomas; Monari, L; Palmonari, F; Rimondi, F; Zichichi, A

    1972-01-01

    The proof is given for the existence of the reaction e/sup +/e/sup -/ to /sup +or-/h/sup -or+/ in the energy range 1400-2400 MeV, and its energy dependence is compared with that of e/sup +/e/sup -/ to e/sup +or-/E/sup -or+/, in the same experimental conditions of observation. The exponent of the s-dependence of the ratio alpha =(e/sup +/e/sup -/ to h/sup +or-/h/sup -or+/)/(e/sup +/e/sup -/ to e/sup +or-/e/sup -or+ /) is measured to be n=2.08+or-0.45, in the s-range (1.96-5.76)GeV/sup 2/, on the basis of 51 e/sup +/e/sup -/ to /sup +or-/h/sup -or+/ events and 8918 e/sup +/e/sup -/ to /sup +or-/e/sup -or+/ events observed. (8 refs).

  12. Commissioning of the CERN LINAC4 BPM System with 50 Mev Proton Beamns

    CERN Document Server

    Tan, J; Søby, L; Sordet, M; Wendt, M

    2013-01-01

    The new Linac4 at CERN will provide a 160 MeV H- ion beam for charge-exchange injection into the existing CERN accelerator complex. Shorted stripline pick-ups placed in the Linac intertank regions and the transfer lines will measure beam orbit, relative beam current, beam phase, and average beam energy via the time-of-flight between two pickups. A prototype Beam Position Monitor (BPM) system has been installed in the transfer line between the existing Linac2 and the Proton Synchrotron Booster (PSB) in order to study and review the complete acquisition chain. This paper presents measurements and performance of this BPM system operating with 50 MeV proton beams, and compares the results with laboratory measurements and electromagnetic simulations.

  13. Initial operation of the Sherbrooke EBCO 19 MeV cyclotron

    Energy Technology Data Exchange (ETDEWEB)

    Erdman, K.L.; Cackette, M.; Dehnel, M.P.; Gyles, W.; Johnson, R.R.; Kovac, B.; Popa, I.; Sabaiduc, V.; Watt, R.; Sliwinski, A. [EBCO Technologies Inc., Richmond BC (Canada); Van Lier, J.E. [Sherbrooke Univ., PQ (Canada). Faculte de Medicine

    1999-07-01

    A variable energy TR19 cyclotron built by EBCO Technologies was installed and commissioned at the Centre Hospitalier Universite de Sherbrooke at the end of 1997. This negative ion cyclotron is capable of accelerating a 150 {mu}Amp of protons to over 19 MeV energy and two simultaneous beams of protons of energies between 13 and 19 MeV can be extracted on opposite sides of the magnet. A novel target changer permits the positioning of the variable energy beams, which leave the magnet at different angles, into long gaseous targets. Properties of the beams used for the production of both PET and SPECT isotopes, made possible by the variable energy feature, are discussed. (authors)

  14. Accurate determination of gamma-ray energies for E<=2 MeV

    Science.gov (United States)

    Kessler, E. G.; Greene, G. L.; Deslattes, R. D.; Börner, H. G.

    1985-01-01

    A flat crystal spectrometer facility has been established at the 57 MW reactor at the Institut Laue-Langevin (ILL). The high flux reactor with the associated source changing facilities produces the intense capture gamma-rays needed for the high-resolution low-efficiency spectrometer. Initial measurements of gamma-ray energies up to 2 MeV from the reaction 35Cl(n,γ) have clearly demonstrated that sub-ppm measurements of intense sources are possible in the 2 to 4 MeV region. Energy values for the 517, 786, 788, 1165, 1951, 1959 keV lines are available with uncertainties of ˜1 ppm. Three of these lines (786+1165=1951) satisfy the sum rule to better than 1 ppm. Future prospects for high energy capture γ-ray measurements which impact on the neutron mass and the fundamental constants are briefly discussed.

  15. Ion beam induced luminescence from diamond using an MeV ion microprobe

    Energy Technology Data Exchange (ETDEWEB)

    Bettiol, A.A.; Jamieson, D. N.; Prawer, S.; Allen, M.G. [Melbourne Univ., Parkville, VIC (Australia). School of Physics

    1993-12-31

    Analysis of the luminescence induced by a MeV ion beam offers the potential to provide useful information about the chemical properties of atoms in crystals to complement the information provided by more traditional Ion Beam Analysis (IBA) such as Rutherford Backscattering Spectrometry (RBS), ion channeling and Particle Induced X-ray Emission (PIXE). Furthermore, the large penetration depth of the MeV ion beam offers several advantages over the relatively shallow penetration of keV electrons typically employed in cathodoluminescence. An Ion Beam Induced Luminescence (IBIL) detection system was developed for the Melbourne microprobe that allows the spatial mapping of the luminescence signal along with the signals from RBS and PIXE. Homoepitaxial diamond growth has been studied and remarkable shifts in the characteristic blue luminescence of diamond towards the green were observed in the overgrowth. This has been tentatively identified as being due to transition metal inclusions in the epitaxial layers. 8 refs., 2 refs.

  16. A 7MeV S-Band 2998MHz Variable Pulse Length Linear Accelerator System

    CERN Document Server

    Hernandez, Michael; Mishin, Andrey V; Saverskiy, Aleksandr J; Skowbo, Dave; Smith, Richard

    2005-01-01

    American Science and Engineering High Energy Systems Division (AS&E HESD) has designed and commissioned a variable pulse length 7 MeV electron accelerator system. The system is capable of delivering a 7 MeV electron beam with a pulse length of 10 nS FWHM and a peak current of 1 ampere. The system can also produce electron pulses with lengths of 20, 50, 100, 200, 400 nS and 3 uS FWHM with corresponding lower peak currents. The accelerator system consists of a gridded electron gun, focusing coil, an electrostatic deflector system, Helmholtz coils, a standing wave side coupled S-band linac, a 2.6 MW peak power magnetron, an RF circulator, a fast toroid, vacuum system and a PLC/PC control system. The system has been operated at repetition rates up to 250pps. The design, simulations and experimental results from the accelerator system are presented in this paper.

  17. The design of a proton recoil telescope for 14 MeV neutron spectrometry

    CERN Document Server

    Hawkes, N P; Croft, S; Jarvis, O N; Sherwood, A C

    2002-01-01

    As part of the design effort for a 14 MeV neutron spectrometer for the Joint European Torus (JET), computer codes were developed to calculate the response of a proton recoil telescope comprising a proton radiator film mounted in front of a proton detector. The codes were used to optimise the geometrical configuration in terms of efficiency and resolution, bearing in mind the constraints imposed by the proposed application as a JET neutron diagnostic for the Deuterium-Tritium phase. A prototype instrument was built according to the optimised design, and tested with monoenergetic 14 MeV neutrons from the Harwell 500 keV Van de Graaff accelerator. The measured energy resolution and absolute efficiency were found to be in acceptable agreement with the calculations. Based on this work, a multi-radiator production version of the spectrometer has now been constructed and successfully deployed at JET.

  18. Designing of the 14 MeV neutron moderator for BNCT

    Science.gov (United States)

    Cheng, Dao-Wen; Lu, Jing-Bin; Yang, Dong; Liu, Yu-Min; Wang, Hui-Dong; Ma, Ke-Yan

    2012-09-01

    In boron neutron capture therapy (BNCT), the ratio of the fast neutron flux to the neutron flux in the tumor (RFNT) must be less than 3%. If a D-T neutron generator is used in BNCT, the 14 MeV neutron moderator must be optimized to reduce the RFNT. Based on the neutron moderation theory and the simulation results, tungsten, lead and diamond were used to moderate the 14 MeV neutrons. Satisfying RFNT of less than 3%, the maximum neutron flux in the tumor was achieved with a three-layer moderator comprised of a 3 cm thick tungsten layer, a 14 cm thick lead layer and a 21 cm thick diamond layer.

  19. The design of the 300 MeV proton microprobe system in Harbin

    Science.gov (United States)

    Dou, Yanxin; Jamieson, David N.; Liu, Jianli; Lv, Kun; Li, Liyi

    2017-08-01

    In Harbin, a 300 MeV proton microprobe system is under development for many applications in space science studies including upset studies in microelectronic devices, radiation hardness of materials for satellites and radiation effects in human tissues. The microprobe system, as a component of Space Environment Simulation Research Infrastructure (SESRI), will employ a purpose-built synchrotron to provide the proton beam. Our design goal for the 300 MeV proton microprobe is for energy spread 0.1%, emittance 10π mm mrad, intensity 109 per pulse and a probe size of 10 μm. A magnetic quadrupole lens system will be used to focus the microprobe with a demagnification of 50. This paper presents a systematic investigation of the ion beam optics to optimize the design. The feasibility of the design for the Harbin system is evaluated by comparison with existing microprobe systems designed for high energy ions.

  20. Energy-range relations for hadrons in nuclear matter

    Science.gov (United States)

    Strugalski, Z.

    1985-01-01

    Range-energy relations for hadrons in nuclear matter exist similarly to the range-energy relations for charged particles in materials. When hadrons of GeV kinetic energies collide with atomic nuclei massive enough, events occur in which incident hadron is stopped completely inside the target nucleus without causing particle production - without pion production in particular. The stoppings are always accompanied by intensive emission of nucleons with kinetic energy from about 20 up to about 400 MeV. It was shown experimentally that the mean number of the emitted nucleons is a measure of the mean path in nuclear matter in nucleons on which the incident hadrons are stopped.

  1. Beam dynamics design and error study of the 5 MeV RFQ

    CERN Document Server

    Luo Zi Hua; Guan Xia Ling; Guo, Z Y; WangLinLin

    2002-01-01

    An RFQ, which will be operated at 352 MHz frequency and 6% duty factor and will accelerate 50 mA proton beam from 80 keV to 5 MeV, has been proposed as an injector of the verification facility of Accelerator Driven System (ADS) for Radioactive Clear Nuclear Power System in China. The RFQ general layout and beam dynamics simulation and error study are described

  2. Experimental determination of kerma factors at E/sub n/ approx. = 15 MeV

    Energy Technology Data Exchange (ETDEWEB)

    Goldberg, E.; Slaughter, D.R.; Howell, R.H.

    1978-04-05

    Experimental values for the kerma per unit fluence at the neutron energy, E/sub n/ = 15 MeV, have been determined for graphite, Mg, and Fe. Ion chambers of small size with walls of these materials were employed, and were filled with a variety of gases--N/sub 2/, CO/sub 2/, Ne, Ar, Kr, and Xe. A calibrated neutron source was employed, allowing a straightforward determination of the kerma per unit fluence.

  3. Impurity/defect interactions during MeV Si{sup +} ion implantation annealing

    Energy Technology Data Exchange (ETDEWEB)

    Agarwal, A.; Koveshnikov, S.; Christensen, K. [North Carolina State Univ., Raleigh, NC (United States)] [and others

    1995-08-01

    Ion implantation of dopant atoms at MeV energies is currently being explored in several integrated circuit device manufacturing processes. MeV implantation offers immediate advantages such as vertical well modulation, latch-up protection, device structure isolation, and reduced temperature processing. Simultaneously, it presents an opportunity to achieve {open_quotes}proximity{close_quotes} gettering of impurities from the active device region by placing high impurity solubility and/or secondary defect gettering sites within microns of the surface. If the MeV implanted species is a dopant ion, all three gettering mechanisms, i.e, segregation, relaxation and injection, can be involved in the gettering process, complicating the analysis and optimization of the process. However, investigation of gettering using non-dopant Si{sup +} ion damage allows the relaxation component of the gettering process to be isolated and examined separately. In general, gettering is verified by a reduction in impurity concentration in the region of interest, usually the device region, and/or a build-up of concentration/precipitation in a non-device sink region. An alternate and more meaningful approach is to use simple devices as materials characterization probes via changes in the electrical activity of the gettering sites. Device space charge probes also allow the evolution of the defect sites upon contamination to be tracked. We report here results of the electrical, structural, and chemical characterization of MeV implanted Si{sup +} damage using Deep Level Transient Spectroscopy (DLTS), Transmission Electron Microscopy (TEM), and Secondary Ion Mass Spectroscopy (SIMS). The damage has been characterized both as a function of annealing from 600 to 1100{degrees}C for 1 hr, and after contamination with Fe followed by low temperature gettering annealing.

  4. (n,2n) reaction cross-sections at 14 MeV

    Indian Academy of Sciences (India)

    (N − Z)/A. Tel et al [12] investigated the (n, charged particle) and (n, 2n) reac- tion cross-sections and the change of pairing effects with respect to the asymmetry parameter for 14–15 MeV incident neutron energies and for odd–even properties of the target nuclei. In the present work, an attempt has been made to develop.

  5. Positronium formation in helium bubbles in 600 MeV proton-irradiated aluminium

    DEFF Research Database (Denmark)

    Jensen, K. O.; Eldrup, Morten Mostgaard; Singh, Bachu Narain

    1985-01-01

    Aluminium samples containing helium bubbles produced by 600 MeV proton irradiation at 430°C were investigated by positron annihilation; both lifetime and angular correlation measurements were made. The angular correlation curves contain an unusually narrow component. This component is associated...... with positronium formation in the bubbles. The width of the component indicates localisation of the Ps atom, possibly in a surface physisorbed state. Sodium segregated at the surfaces of the bubbles is a likely cause of the positronium formation...

  6. Radiative model of neutrino mass with neutrino interacting MeV dark matter

    Energy Technology Data Exchange (ETDEWEB)

    Arhrib, Abdesslam [Département de Mathématique, Faculté des Sciences et Techniques,Université Abdelmalek Essaadi,B. 416, Tangier (Morocco); Boehm, Céline [LAPTH, UMR 5108,9 chemin de Bellevue, BP 110, 74941 Annecy-Le-Vieux (France); Ma, Ernest [Department of Physics and Astronomy, University of California,Riverside, California 92521 (United States); Yuan, Tzu-Chiang [Institute of Physics, Academia Sinica,Nangang, Taipei 11529, Taiwan (China); Physics Division, National Center for Theoretical Sciences,Hsinchu, Taiwan (China)

    2016-04-26

    We consider the radiative generation of neutrino mass through the interactions of neutrinos with MeV dark matter. We construct a realistic renormalizable model with one scalar doublet (in additional to the standard model doublet) and one complex singlet together with three light singlet Majorana fermions, all transforming under a dark U(1){sub D} symmetry which breaks softly to Z{sub 2}. We study in detail the scalar sector which supports this specific scenario and its rich phenomenology.

  7. Scattering of {sup 8}He on {sup 208}Pb at 22 MeV

    Energy Technology Data Exchange (ETDEWEB)

    Marquinez-Duran, G.; Sanchez-Benitez, A. M.; Martel, I.; Berjillos, R.; Duenas, J. A.; Parkar, V. V. [Depto. de Fisica Aplicada, Universidad de Huelva, 21071 Huelva (Spain); Acosta, L. [Depto. de Fisica Aplicada, Universidad de Huelva, 21071 Huelva, Spain and Laboratori Nazionali del Sud, INFN, Via Santa Sofia 62, 95123, Catania (Italy); Rusek, K. [Heavy Ion Laboratory, University of Warsaw (Poland); Alvarez, M. A. G.; Gomez-Camacho, J. [Centro Nacional de Aceleradores, 41092, Sevilla, Spain and Depto. de Fisica Atomica, Molecular y Nuclear, Universidad de Sevilla, 41080 Sevilla (Spain); Borge, M. J. G.; Cruz, C.; Cubero, M.; Pesudo, V.; Tengblad, O. [Instituto de Estructura de la Materia, CSIC, 28006 Madrid (Spain); Chbihi, A. [GANIL, CEA and IN2P3-CNRS, B.P. 5027, 14076 Caen cedex (France); Fernandez-Garcia, J. P.; Moro, A. M. [Depto. de Fisica Atomica, Molecular y Nuclear, Universidad de Sevilla, 41080 Sevilla (Spain); Fernandez-Martinez, B.; Labrador, J. A. [Centro Nacional de Aceleradores, 41092, Sevilla (Spain); and others

    2013-06-10

    The skin nucleus {sup 8}He is investigated by measuring the angular distribution of the elasticly scattered {sup 8}He and the {sup 6,4}He fragments produced in the collision with a {sup 208}Pb target at 22 MeV, just above the Coulomb barrier. The experiment was carried out at SPIRAL/GANIL in 2010. Here we present preliminary results for the elastic scattering.

  8. Radiography studies with gamma rays produced by 14-MeV fusion neutrons

    Energy Technology Data Exchange (ETDEWEB)

    Smith, D.L. [Argonne National Lab., IL (United States). Technology Development Div.; Ikeda, Yujiro; Uno, Yoshitomo [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Fusion Neutronics Lab.

    1996-12-31

    Oxygen contained in pure water has been activated via the {sup 16}O(n, p){sup 16}N reaction using 14-MeV neutrons produced at a neutron generator with the {sup 3}H(d,n){sup 4}He source. Photons of 6.129 and 7.115 MeV, generated by the decay of 7.13-second {sup 16}N, were then used to demonstrate the feasibility of employing highly penetrating, nearly monoenergetic gamma rays for radiography studies of thick, dense objects composed of elements with medium to relatively high atomic numbers. A simple radiography apparatus was constructed by circulating water continuously between a position near the target of the neutron generator and a remote location where photon transmission measurements were conducted. A sodium iodide scintillator was employed to detect the photons. Pulses equivalent to photon energies smaller than 2.506 MeV (corresponding to the cascade sum of 1.333- and 1.173-MeV gamma rays from the decay of 5.271-year {sup 60}Co) were rejected by the electronics settings in order to reduce background and improve the signal-to-noise (S/N) ratio. Respectable S/N ratios on the order of 20-to-1 were achieved with this setup. Most of the background (N) could be attributed to ambient environmental radiation and cosmic-ray interactions with the lead shielding and detector. Four representative objects were examined by photon radiography in this study. This demonstrated how such - interesting features as hidden holes and discontinuities in atomic number could be easily identified from observed variations in the intensity of transmitted photons. Some advantages of this technique are described, and potential applications are suggested for a future scenario where fusion reactors are used to generate electric power and very intense sources of high-energy photons from {sup 16}N decay are continuously available as a byproduct of the reactor cooling process.

  9. Wolfenstein polarization observables for the reaction ppolp-->ppolπn at 800 MeV

    Science.gov (United States)

    Hollas, C. L.; McNaughton, K. H.; Riley, P. J.; Xu, Shen-Wu; Bonner, B. E.; van Dyck, O. B.; McGill, J.; McNaughton, M. W.; Peng, J. C.; Silbar, R. R.; Dubach, J.; Kloet, W. M.

    1985-07-01

    The Wolfenstein polarization observables DNN, DSΩ, and DLΩ, where Ω denotes a mixture of S and L polarization components, and the induced polarization P have been measured for the reaction pp-->pπ+n at 800 MeV, at geometries corresponding to Δ++ production from ~10° to 80° in the center of mass. Comparisons are made to results from the model of Dubach, Kloet, and Silbar.

  10. Performance of the Fermilab's 4.3 MeV electron cooler

    Energy Technology Data Exchange (ETDEWEB)

    Shemyakin, A.; Burov, Alexey V.; Carlson, K.; Hu, M.; Kroc, T.; Leibfritz, J.; Nagaitsev, S.; Prost, L.R.; Pruss, S.; Saewert, G.; Schmidt, C.W.; Sutherland, M.; Tupikov,; Warner, A.; /Fermilab

    2006-06-01

    A 4.3 MeV DC electron beam is used to cool longitudinally an antiproton beam in the Fermilab's Recycler ring. Cooling capabilities of the electron beam are characterized by the drag rate that was measured at various conditions. Fitting the results with a formula for non-magnetized cooling gives electron parameters that agree within a factor of 2 with independently measured electron beam properties.

  11. Distributions of secondary particles around various targets exposed to 50 MeV protons

    CERN Document Server

    Fassò, A

    1976-01-01

    The particle production in thick targets of carbon, aluminium, and copper, hit by 50 MeV protons, has been studied with activation detectors. The measured angular distribution of secondaries around the targets was compared with calculations making use of semi-empirical formulae proposed by Alsmiller et. al. In general, the agreement between experiment and theory is good, except for large angles where the experimentally found production of secondaries is greater than predicted by the calculation. (17 refs).

  12. Upper limit on the inner radiation belt MeV electron intensity

    OpenAIRE

    Li, X; Selesnick, RS; Baker, DN; Jaynes, AN; Kanekal, SG; Schiller, Q; Blum, L; Fennell, J; Blake, JB

    2015-01-01

    No instruments in the inner radiation belt are immune from the unforgiving penetration of the highly energetic protons (tens of MeV to GeV). The inner belt proton flux level, however, is relatively stable; thus, for any given instrument, the proton contamination often leads to a certain background noise. Measurements from the Relativistic Electron and Proton Telescope integrated little experiment on board Colorado Student Space Weather Experiment CubeSat, in a low Earth orbit, clearly demonst...

  13. Search for a neutral particle of mass 33.9 MeV in pion decay

    Energy Technology Data Exchange (ETDEWEB)

    Daum, M.; Frosch, R.; Hajdas, W. [PSI Paul Scherrer Inst., Villingen-PSI (Switzerland)] [and others

    1997-12-31

    The muon momentum distribution in charged pion decay in flight in order to search for a small branching fraction {eta} of pion decays {pi}{sup +} {yields} {mu}{sup +} + X, in which a heavy neutral particle X with a mass of 33.9 MeV would be emitted has been measured. The upper limit of {eta} at a confidence level of 95 % is found to be 2.6 x 1{sup -8}. (orig.)

  14. Pion elastic and inelastic scattering from 51V at 180 MeV

    Science.gov (United States)

    Oakley, D. S.; Machuca, M. A.; Smithson, M. J.; Mordechai, S.; Moore, C. Fred; Seidl, P. A.; Morris, C. L.; Wang, Z. F.; Gilman, R.; Zumbro, J. D.; Fortune, H. T.; Seestrom-Morris, S. J.; Dhuga, K. S.; Watson, D. L.

    1987-09-01

    Differential cross sections were measured for pion elastic and inelastic scattering from 51V at Tπ=180 MeV. Elastic scattering data were analyzed using a standard Kisslinger potential. Inelastic scattering data were analyzed using distorted-wave impulse-approximation calculations with collective-model transition densities. Ground-state neutron-density parameters and matrix elements for some of the transitions were extracted.

  15. Radiation-induced effects in MgO single crystal by 200 keV and 1 MeV Ni ion implantation

    Energy Technology Data Exchange (ETDEWEB)

    Takahashi, Ryohei; Nakai, Yoshihiro; Hamaguchi, Dai [Kyoto Inst. of Tech. (Japan)] [and others

    1997-03-01

    MgO(100) single crystals were implanted with 1.0 MeV and 200 keV Ni ions between 10{sup 15} and 10{sup 17} ions/cm{sup 2} at room temperature. Before and after thermal annealing the radiation damage and the lattice location of implanted Ni ions were analyzed by using Rutherford backscattering spectrometry with channeling and optical absorption measurements. For 1.0 MeV Ni ions, the disorder of Mg atoms increased slowly with ion dose near surface region, while it increased sharply and saturated with ion dose from 2x10{sup 16} ions/cm{sup 2} near ion range. The radiation damage was recovered and implanted Ni ions diffused to the whole of crystal and occupied substitutional positions after 1400degC annealing. For 200 keV Ni ions, the disorder of Mg atoms increased with dose near ion range and had a maximum at about 5x10{sup 16} ions/cm{sup 2}. This tendency agrees with the behavior of color centers obtained from optical measurements. For thermal annealing the radiation damage did not change during 500degC annealing, but the aggregate centers appeared after 300degC annealing. (author)

  16. Dielectric relaxation, structural and thermal studies of 95 MeV O6+ ion irradiated conducting polymer polyaniline-polyvinyl alcohol

    Science.gov (United States)

    Himanshu, A. K.; Ray, Rajyavardhan; El-Sayed, S.; Hassen, A.; Bandyopadhayay, S. K.; Sinha, T. P.

    2014-01-01

    Polyaniline (PANI) film prepared from using water-soluble support polymer polyvinyl alcohol (PVA) has been irradiated with 95 MeV oxygen (O6+) ions at the fluences from 1011 to 1012 ions/cm2. The thermal, dielectric, structural and microstructural properties of the samples are investigated by differential scanning calorimeter and thermogravimetric analysis, LCR meter, X-ray diffraction and scanning electron microscope. The structural studies reveal that amorphization on irradiation which may be due to the scission of polymer bonds as there is a signature of columnar tracts and the appearance of voids in the sample increases with increasing O6+ ions irradiation-dose. Frequency-dependent spectra of the imaginary electric modulus suggest that long-range conduction in pristine sample changes to short-range, i.e. localized conduction in 95 MeV O6+ ion-irradiation PANI-PVA. The behaviour of the ac conductivity reveals that the conduction mechanism in both pristine and irradiated sample is correlated to the barrier hopping model.

  17. Measurement of the 10B(p ,α0)7Be cross section from 5 keV to 1.5 MeV in a single experiment using the Trojan horse method

    Science.gov (United States)

    Spitaleri, C.; Puglia, S. M. R.; La Cognata, M.; Lamia, L.; Cherubini, S.; Cvetinović, A.; D'Agata, G.; Gulino, M.; Guardo, G. L.; Indelicato, I.; Pizzone, R. G.; Rapisarda, G. G.; Romano, S.; Sergi, M. L.; Spartá, R.; Tudisco, S.; Tumino, A.; Del Santo, M. Gimenez; Carlin, N.; Munhoz, M. G.; Souza, F. A.; de Toledo, A. Szanto; Mukhamedzhanov, A.; Broggini, C.; Caciolli, A.; Depalo, R.; Menegazzo, R.; Rigato, V.; Lombardo, I.; Dell'Aquila, D.

    2017-03-01

    For the first time the astrophysical factor of the 10B(p ,α0)7Be reaction has been measured over a wide energy range, from 5 keV to 1.5 MeV, via the Trojan horse method (THM) applied to the quasifree 2H(10B,α 7Be)n reaction. Therefore, the S (E ) factor has been recast into absolute units by scaling in the energy range 200 keV-1.2 MeV to a recent measurement using the activation method, leading to a normalization uncertainty of 4 % . An R -matrix fit of the THM data was performed, to parametrize the S factor, obtain spectroscopic information on the populated resonances, and compare with other recent experiments. Finally, a new determination of the screening potential Ue has been obtained, Ue=240 ±50 eV, with a much smaller error than our previous measurement.

  18. Measurement of 15 MeV gamma-rays with the Ge cluster detectors of EUROBALL

    CERN Document Server

    Million, B; Camera, F; Brambilla, S; Gadea, A; Giugni, D; Herskind, B; Kmiecik, M; Isocrate, R; Leoni, S; Maj, A; Prelz, F; Wieland, O

    2000-01-01

    A measurement of the response to 15.1 MeV gamma-rays has been made for the Ge cluster detectors in the EUROBALL array. Each cluster detector consists of seven germanium capsules surrounded by a single anticompton shield of BGO. The reaction D( sup 1 sup 1 B,gamma) sup 1 sup 2 C+n at E sub b sub e sub a sub m =19.1 MeV has been employed. The 'adding-back' of signals simultaneously present in the capsules composing each cluster detector has been made on an event by event basis. The intensity in full-energy peak increases by a factor of three as compared to that of the spectrum obtained by summing the individual spectra of the 7 capsules. The pulse height to energy conversion is found to be very linear from few hundreds keV to 15 MeV. The efficiency is discussed relative to that of large volume BaF sub 2 scintillators.

  19. The evaluation of 6 and 18 MeV electron beams for small animal irradiation

    Science.gov (United States)

    Chao, T. C.; Chen, A. M.; Tu, S. J.; Tung, C. J.; Hong, J. H.; Lee, C. C.

    2009-10-01

    A small animal irradiator is critical for providing optimal radiation dose distributions for pre-clinical animal studies. This paper focuses on the evaluation of using 6 or 18 MeV electron beams as small animal irradiators. Compared with all other prototypes which use photons to irradiate small animals, an electron irradiator has many advantages in its shallow dose distribution. Two major approaches including simulation and measurement were used to evaluate the feasibility of applying electron beams in animal irradiation. These simulations and measurements were taken in three different fields (a 6 cm × 6 cm square field, and 4 mm and 30 mm diameter circular fields) and with two different energies (6 MeV and 18 MeV). A PTW Semiflex chamber in a PTW-MP3 water tank, a PTW Markus chamber type 23343, a PTW diamond detector type 60003 and KODAK XV films were used to measure PDDs, lateral beam profiles and output factors for either optimizing parameters of Monte Carlo simulation or to verify Monte Carlo simulation in small fields. Results show good agreement for comparisons of percentage depth doses (water phantom and a CT-based heterogeneous mouse phantom, and were implemented into Monte Carlo to simulate dose distribution with different electron irradiations.

  20. Thermodynamical features of multifragmentation in peripheral Au + Au collisions at 35 A MeV

    Science.gov (United States)

    D'Agostino, M.; Botvina, A. S.; Bruno, M.; Bonasera, A.; Bondorf, J. P.; Bougault, R.; Désesquelles, P.; Geraci, E.; Gulminelli, F.; Iori, I.; Le Neindre, N.; Margagliotti, G. V.; Mishustin, I. N.; Moroni, A.; Pagano, A.; Vannini, G.

    1999-04-01

    The distribution of fragments produced in events involving the multifragmentation of excited sources is studied for peripheral Au + Au reactions at 35 A MeV. The Quasi-Projectile has been reconstructed from its de-excitation products. An isotropic emission in its rest frame has been observed, indicating that an equilibrated system has been formed. The excitation energy of the Quasi-Projectile has been determined via calorimetry. A new event by event effective thermometer is proposed based on the energy balance. A peak in the energy fluctuations is observed related to the heat capacity suggesting that the system undergoes a liquid-gas type phase transition at an excitation energy ˜ 5 A MeV and a temperature 4-6 MeV, dependent on the freeze-out hypothesis. By analyzing different regions of the Campiplot, the events associated with the liquid and gas phases as well as the critical region are thermodynamically characterized. The critical exponents, τ, β, γ, extracted from the high moments of the charge distribution are consistent with a liquid-gas type phase transition.

  1. EXPERIMENTAL ANALYSES OF SPALLATION NEUTRONS GENERATED BY 100 MEV PROTONS AT THE KYOTO UNIVERSITY CRITICAL ASSEMBLY

    Directory of Open Access Journals (Sweden)

    CHEOL HO PYEON

    2013-02-01

    Full Text Available Neutron spectrum analyses of spallation neutrons are conducted in the accelerator-driven system (ADS facility at the Kyoto University Critical Assembly (KUCA. High-energy protons (100 MeV obtained from the fixed field alternating gradient accelerator are injected onto a tungsten target, whereby the spallation neutrons are generated. For neutronic characteristics of spallation neutrons, the reaction rates and the continuous energy distribution of spallation neutrons are measured by the foil activation method and by an organic liquid scintillator, respectively. Numerical calculations are executed by MCNPX with JENDL/HE-2007 and ENDF/B-VI libraries to evaluate the reaction rates of activation foils (bismuth and indium set at the target and the continuous energy distribution of spallation neutrons set in front of the target. For the reaction rates by the foil activation method, the C/E values between the experiments and the calculations are found around a relative difference of 10%, except for some reactions. For continuous energy distribution by the organic liquid scintillator, the spallation neutrons are observed up to 45 MeV. From these results, the neutron spectrum information on the spallation neutrons generated at the target are attained successfully in injecting 100 MeV protons onto the tungsten target.

  2. Observations on late effects in mice exposed to 400 MeV neutrons

    CERN Document Server

    Covelli, V; Bassani, B; Baarli, Johan; Bianchi, M; Metalli, P; Covelli, V; Di Paola, M; Bassani, B; Baarli, J no 2; Bianchi, M no 2; Metalli, P

    1976-01-01

    Life-long observations on mortality and pathology at death were carried out on groups of mice irradiated with 250 kV X-rays or exposed to a 400 MeV neutron beam, both directly and after attenuation corresponding to the maximum dose build-up region, at comparable dose-rates. Doses up to 84 rad of 400 MeV neutrons and up to 200 rad of X-rays showed no effect on the longevity of the animals, which suggests an upper limit to the r.b.e. for life-shortening of approximately 2·5. Similar conclusions were drawn from the data on all types of leukemias. For all other neoplasms, the age-specific death-rate showed a similar shortening of the latency times for groups of mice irradiated with 0–84 rad of 400 MeV direct neutrons and 0–400 rad of X-rays, also suggesting an upper limit to the r.b.e. slightly higher than that previously indicated for life-shortening. No definite effect was observed after exposure to the attenuated neutron beam at the doses used in these experiments.

  3. Evaluation of induced radioactivity in 10 MeV electron-irradiated spices

    Energy Technology Data Exchange (ETDEWEB)

    Furuta, Masakazu; Ito, Norio; Mizohata, Akira; Matsunami, Tadao; Katayama, Tadashi; Toratani, Hirokazu (Osaka Prefectural Univ., Sakai (Japan). Research Inst. for Advanced Science and Technology); Takeda, Atsuhiko

    1993-10-01

    In order to make clear appreciation to induced radioactivity in the irradiated foods, photonuclear reactions which could produce radioactivity at energies up to 10 MeV were listed up from elemental compositions of black pepper, white pepper, red pepper, ginger and turmeric. The samples were irradiated with 10 MeV electron from a linear accelerator to a dose of 100 kGy and radioactivity was measured. Induced radioactivity could not be detected significantly by gamma-ray spectrometry and beta-ray counting in the irradiated samples except for spiked samples which contain some photonuclear target nuclides in the list. From the amount of observed radioactivities of short-lived photonuclear products in the spiked samples and calculation of H[sub 50] according to ICRP Publication 30, it was concluded that the induced radioactivity and its biological effects in the 10 MeV electron-irradiated natural samples were negligible in comparison with natural radioactivity from [sup 40]K contained in the samples. (J.P.N.).

  4. Release the beams! - Linac4 ready to hit the 50 MeV mark

    CERN Document Server

    Katarina Anthony

    2015-01-01

    The Linac4 accelerator is now prepared to reach 50 MeV. This milestone energy - expected in the coming weeks - will allow the machine to act as a replacement for the ageing Linac2, four years before it takes over at the head of the accelerator chain in 2020.    Inside the Linac4 tunnel, the final DTL cavities will guide beams to 50 MeV.  (Image: Stephan Russenschuck.) The Linac4 accelerator will bring H- ion beams (hydrogen atoms with an extra electron) up to 160 MeV for injection into the PS Booster. As a key part of the LHC injector upgrade programme, Linac4 will allow the PS Booster to double its beam brightness, which will contribute to increasing the LHC’s luminosity. Linac4 will soon bring beams up to 50 MeV - the current energy delivered by the Linac2 accelerator. This milestone follows on from another recent accomplishment: the installation and commissioning of the final Drift Tube Linac (DTL) tank. Using an innovati...

  5. Deep proton writing with 12 MeV protons for rapid prototyping of microstructures in polymethylmethacrylate

    Science.gov (United States)

    Ebraert, Evert; Gökçe, Berkcan; Van Vlierberghe, Sandra; Vervaeke, Michael; Meyer, Pascal; Guttmann, Markus; Dubruel, Peter; Thienpont, Hugo; Van Erps, Jürgen

    2016-10-01

    Deep proton writing (DPW) is a fabrication technology developed for the rapid prototyping of polymer microstructures. We use polymethylmethacrylate (PMMA) substrates, which act as a positive resist, for irradiation with a collimated 12-MeV energy proton beam. Using 12 MeV enables the irradiation of increasingly thick PMMA substrates with less conicity of the sidewalls compared to the lower energies used in previous work. A microhole of 47.7 μm diameter over a depth of 1 mm is achieved, leading to a maximum aspect ratio of 21∶1. The sidewalls of the irradiated structures show a slightly conical shape and their root-mean-square surface roughness is lower than 50 nm averaged over 72 measured areas of 56 μm×44 μm. This means that DPW components have optical surface quality sidewalls for wavelengths larger than 400 nm. Based on the trade-off among the sidewall roughness, conicity, and the development time, we determine that the optimal proton fluence for 12-MeV DPW in PMMA is 7.75×106 μm-2. Finally, we discuss some high aspect ratio microstructures with optical surface quality that were created with DPW to be used for a myriad of applications, such as micromirrors, microlenses, optofluidic devices, and high-precision alignment structures for single-mode optical fiber connectors.

  6. Bias dependent charge trapping in MOSFETs during 1 and 6 MeV electron irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Shinde, N.S. [Department of Chemical Engineering, Mie University, 5148507 (Japan); Kulkarni, V.R.; Mathakari, N.L.; Bhoraskar, V.N. [Department of Physics, Univeristy of Pune, Pune 411007 (India); Dhole, S.D. [Department of Physics, Univeristy of Pune, Pune 411007 (India)], E-mail: sanjay@physics.unipune.ernet.in

    2008-06-15

    To study irradiation-induced charge trapping in SiO{sub 2} and around the SiO{sub 2}-Si interface, depletion n-MOSFETs (metal-oxide-semiconductor field effect transistor) were used. The devices were gate biased during 1 and 6 MeV pulsed electron irradiation. The I{sub D}-V{sub DS} (drain current versus drain voltage) and I{sub D}-V{sub GS} (drain current versus gate voltage) characteristics were measured before and after irradiation. The shift in threshold voltage {delta}V{sub T} (difference in threshold voltage V{sub T} before and after irradiation) exhibited trends depending on the applied gate bias during 1 MeV electron irradiation. This behavior can be associated to the contribution of irradiation-induced negative charge {delta}N{sub IT} buildup around the SiO{sub 2}-Si interface to {delta}V{sub T}, which is sensitive to the electron tunneling from the substrates. However, only weak gate bias dependence was observed in 6 MeV electron irradiated devices. Independent of the energy loss and applied bias, the positive oxide trapped charge {delta}N{sub OT} is marginal and can be associated to thin and good quality of SiO{sub 2}. These results are explained using screening of free and acceptor states by the applied bias during irradiation, thereby reducing the total irradiation-induced charges.

  7. mA beam acceleration efforts on 100 MeV H- cyclotron at CIAE

    Science.gov (United States)

    Zhang, Tianjue; An, Shizhong; Lv, Yinlong; Ge, Tao; Jia, Xianlu; Ji, Bin; Yin, Zhiguo; Pan, Gaofeng; Cao, Lei; Guan, Fengping; Yang, Jianjun; Li, Zhenguo; Zhao, Zhenlu; Wu, Longcheng; Zhang, He; Wang, Jingfeng; Zhang, Yiwang; Liu, Jingyuan; Li, Shiqiang; Lu, Xiaotong; Liu, Zhenwei; Li, Yaoqian; Guo, Juanjuan; Cao, Xuelong; Guan, Leilei; Wang, Fei; Wang, Yang; Yang, Guang; Zhang, Suping; Hou, Shigang; Wang, Feng

    2017-09-01

    Various technologies for high current compact H- cyclotron have been developed at CIAE since 1990s. A 375 μA proton beam was extracted from a 30 MeV compact H- cyclotron CYCIAE-30 at the end of 1994. A central region model cyclotron CYCIAE-CRM was developed for the design verification of a 100 MeV high current compact H- cyclotron CYCIAE-100. It is also a 10 MeV proton machine as a prototype for PET application. A 430 μA beam was achieved in 2009. The first beam was extracted from the CYCIAE-100 cyclotron on July 4, 2014, the operation stability has been improved and beam current has been increased gradually. A 1.1 mA proton beam was measured on the internal target in July 2016. The effort for an increasing of proton beam has continued till now. In this paper, the effort on several aspects for mA beam development will be presented, including the multi-cusp source, buncher, matching from the energy of the injected beam, vertical beam line and central region, beam loading of the RF system and instrumentation for beam diagnostics etc.

  8. Bremsstrahlung component of the diffuse galactic gamma-ray emission at MeV energies

    Energy Technology Data Exchange (ETDEWEB)

    Sacher, W.; Schoenfelder, V.

    1984-04-15

    Recently the galactic plane has been resolved at low and medium ..gamma..-ray energies in the directions toward the center and anticenter. Spectral measurements are now available at those energies, where the contribution of ..pi../sup 0/-decay from nuclear reactions of cosmic-ray protons (and heavier nuclei) with interstellar matter can be neglected. Under the assumption that most of the observed ..gamma..-ray flux below 30 MeV is produced by electron bremsstrahlung, restrictions on the energy spectrum of cosmic-ray electrons in interstellar space below 100 MeV are derived. The most accurate bremsstrahlung production cross sections of Koch and Motz and of Blumental and Gould are used in order to derive the bremsstrahlung production spectrum in interstellar space down to 10 keV-photon energies. If the low-energy ..gamma..-ray emission, as seen by most observers, is indeed produced by electron bremsstrahlung, then a high interstellar electron flux at MeV energy results, which-at higher energies-connects to the upper limit derived by Cummings, Stone, and Vogt. Such a high low-energy electron flux would be able to explain the ionization rate of 1 x 10/sup -15/ ion pairs (H-atom/sup -1/ s/sup -1/) in H I regions. Because of uncertainties in the low-energy ..gamma..-ray measurements, however, no definite conclusion is possible yet.

  9. Effects of Incomplete Ionization on Ga2O3 Power Device: Unintentional Donor with Energy 110 meV (Preprint)

    Science.gov (United States)

    2017-06-09

    AFRL-RX-WP-JA-2017-0367 EFFECTS OF INCOMPLETE IONIZATION ON Β-Ga2O3 POWER DEVICE: UNINTENTIONAL DONOR WITH ENERGY 110 meV (PREPRINT...EFFECTS OF INCOMPLETE IONIZATION ON Β-Ga2O3 POWER DEVICE: UNINTENTIONAL DONOR WITH ENERGY 110 meV (PREPRINT) 5a. CONTRACT NUMBER FA8650-11-D-5801...found to have a donor energy of 110 meV. The existence of the unintentional donor is confirmed by temperature dependent admittance spectroscopy

  10. Measurements of 15.11-MeV gamma-ray flux produced in the reactions C-12(p, p')-C-12*(15.11 MeV) and O-16(p, p' alpha)-C-12*(15.11 MeV)

    Science.gov (United States)

    Lapides, J. R.; Crannell, C. J.; Crannell, H.; Hornyak, W. F.; Seltzer, S. M.; Trombka, J. I.; Wall, N. S.

    1978-01-01

    The flux of 15.11 MeV gamma rays relative to the flux of 4.44 MeV gamma rays which are emitted from the corresponding states of C-12 are a sensitive measure of the spectrum of exciting particles in solar flares and other cosmic sources. Emission of 15.11 MeV gamma rays may result not only from the direct excitation of C-12 but also from the interaction O-16 (p,p' alpha) C-12* sup 15.11 MeV. Although the cross sections for the direct reaction was studied extensively, the cross section for the spallation interaction with O-16 is not reported in the literature. Preliminary measurements demonstrated the feasibility of measuring the production of 15.11 MeV gamma rays by proton interactions with O-16 using the University of Maryland cyclotron facility. For both carbon and oxygen targets the flux of 15.11 MeV gamma rays is being measured relative to the flux of 4.44 MeV gamma rays. The gamma ray emission from de-excitation of the giant dipole resonances is being measured.

  11. Measurement of 232Th(n,5n γ) cross sections from 29 MeV to 42 MeV

    Science.gov (United States)

    Kerveno, M.; Nolte, R.; Baumann, P.; Dessagne, Ph.; Jericha, E.; Jokic, S.; Koning, A. J.; Lukic, S.; Meulders, J. P.; Nachab, A.; Pavlik, A.; Reginatto, M.; Rudolf, G.

    2014-10-01

    The excitation function of the reaction 232 Th( n, 5 nγ)228 Th from 29 to 42 MeV has been measured for the first time at the quasi-monoenergetic neutron beam of the UCL cyclotron CYCLONE employing the 7Li(p,n) source reaction. Taking advantage of the good energy resolution of the planar High-Purity Germanium (HPGe) detectors, prompt γ-ray spectroscopy was used to detect the γ-rays resulting from the decay of excited states of nuclei created by the (n, xn) reactions. The neutron beam was characterized by a combination of time of flight measurements carried out using a liquid scintillation detector and a 238U fission ionization chamber. Fluence measurements were performed using a proton recoil telescope. The results are compared with TALYS-1.4 code calculations.

  12. Measurement of {sup 232}Th(n, 5nγ) cross sections from 29 MeV to 42 MeV

    Energy Technology Data Exchange (ETDEWEB)

    Kerveno, M.; Baumann, P.; Dessagne, P.; Rudolf, G. [Universite de Strasbourg, IPHC, Strasbourg (France); CNRS, UMR7178, Strasbourg (France); Nolte, R.; Reginatto, M. [Physikalisch-Technische Bundesanstalt, Braunschweig (Germany); Jericha, E. [Technische Universitaet Wien, Atominstitut, Wien (Austria); Jokic, S.; Lukic, S. [Vinca Institute of Nuclear Sciences, Belgrade (Serbia); Koning, A.J. [Nuclear Research and Consultancy Group, Petten (Netherlands); Meulders, J.P. [Institut de Physique Nucleaire, Louvain-la-Neuve (Belgium); Nachab, A. [Universite Cadi Ayyad, Departement de physique, Faculte Poly-disciplinaire de Safi, Safi (Morocco); Pavlik, A. [Faculty of Physics, University of Vienna, Wien (Austria)

    2014-10-15

    The excitation function of the reaction {sup 232} Th(n, 5nγ){sup 228} Th from 29 to 42 MeV has been measured for the first time at the quasi-monoenergetic neutron beam of the UCL cyclotron CYCLONE employing the {sup 7}Li(p,n) source reaction. Taking advantage of the good energy resolution of the planar High-Purity Germanium (HPGe) detectors, prompt γ-ray spectroscopy was used to detect the γ-rays resulting from the decay of excited states of nuclei created by the (n,xn) reactions. The neutron beam was characterized by a combination of time of flight measurements carried out using a liquid scintillation detector and a {sup 238}U fission ionization chamber. Fluence measurements were performed using a proton recoil telescope. The results are compared with TALYS-1.4 code calculations. (orig.)

  13. Study of properties of the plastic scintillator EJ-260 under irradiation with 150 MeV protons and 1.2MeV gamma-rays

    Science.gov (United States)

    Dormenev, V.; Brinkmann, K.-T.; Korjik, M.; Novotny, R. W.

    2017-11-01

    One of the most critical aspects for the application of a scintillation material in high energy physics is the degradation of properties of the material in an environment of highly ionizing particles in particular due to hadrons. There are presently several detector concepts in consideration being based on organic scintillator material for fast timing of charged particles or sampling calorimeters. We have tested different samples of the organic plastic scintillator EJ-260 produced by the company Eljen Technology (Sweetwater, TX, USA). The ongoing activity has characterized the relevant parameters such as light output, kinetics and temperature dependence. The study has focused on the change of performance after irradiation with 150 MeV protons up to an integral fluence of 5·1013 protons/cm2 as well as with a strong 60Co γ-source accumulating an integral dose of 100 Gy. The paper will report on the obtained results.

  14. Measurement of (n,2n) cross-sections for Sc, Mn, Cr and In between 12 and 19 MeV with activation technique

    Energy Technology Data Exchange (ETDEWEB)

    Iwasaki, S.; Win, Than; Matsuyama, S. [Tohoku Univ., Sendai (Japan). Faculty of Engineering; Odano, N.

    1997-03-01

    Activation cross-sections for scandium, manganese, chromium and indium have been measured in the neutron energies from 12 to 19 MeV. Source neutrons were produced via the T(d,n){sup 4}He reaction by bombarding a 3.2-MeV deuteron beam from the Dynamitron accelerator of Fast Neutron Laboratory at Tohoku University. Ten packages of high or ultra-high purity metal foils for chromium and indium, alloy foils for manganese, and oxide powder for scandium were set around the neutron source at 5 cm from the target in the angular range from 0 to 140 deg covering the incident neutron energies from 19 to 12 MeV at the center position of each package. Activation rates of the samples were obtained by the gamma-ray measurements using a high purity germanium detector. Neutron flux at each sample was determined using the activation rates of two niobium foils locating both sides of that sample; the reference reaction was {sup 93}Nb(n,2n){sup 92m}Nb of which cross-section data was taken from the 1991 NEANDC/INDC standard files. The source neutrons distributions have been measured in detail by the time-of-flight technique. The measured cross-sections are the following important dosimetry or activation reactions: {sup 45}Sc(n,2n){sup 44m}Sc, {sup 55}Mn(n,2n){sup 54}Mn, {sup 52}Cr(n,2n){sup 51}Cr, and {sup 115}In(n,2n){sup 114m}In. These cross-sections are compared with available activation file, dosimetry files and previous experimental data. (author)

  15. CR-39 track detector calibration for H, He, and C ions from 0.1-0.5 MeV up to 5 MeV for laser-induced nuclear fusion product identification.

    Science.gov (United States)

    Baccou, C; Yahia, V; Depierreux, S; Neuville, C; Goyon, C; Consoli, F; De Angelis, R; Ducret, J E; Boutoux, G; Rafelski, J; Labaune, C

    2015-08-01

    Laser-accelerated ion beams can be used in many applications and, especially, to initiate nuclear reactions out of thermal equilibrium. We have experimentally studied aneutronic fusion reactions induced by protons accelerated by the Target Normal Sheath Acceleration mechanism, colliding with a boron target. Such experiments require a rigorous method to identify the reaction products (alpha particles) collected in detectors among a few other ion species such as protons or carbon ions, for example. CR-39 track detectors are widely used because they are mostly sensitive to ions and their efficiency is near 100%. We present a complete calibration of CR-39 track detector for protons, alpha particles, and carbon ions. We give measurements of their track diameters for energy ranging from hundreds of keV to a few MeV and for etching times between 1 and 8 h. We used these results to identify alpha particles in our experiments on proton-boron fusion reactions initiated by laser-accelerated protons. We show that their number clearly increases when the boron fuel is preformed in a plasma state.

  16. Serenoa repens associated with Urtica dioica (ProstaMEV) and curcumin and quercitin (FlogMEV) extracts are able to improve the efficacy of prulifloxacin in bacterial prostatitis patients: results from a prospective randomised study.

    Science.gov (United States)

    Cai, Tommaso; Mazzoli, Sandra; Bechi, Adriano; Addonisio, Patrizia; Mondaini, Nicola; Pagliai, Roberto Castricchi; Bartoletti, Riccardo

    2009-06-01

    We report the results of a prospective randomised study to evaluate the therapeutic effect of Serenoa repens, Urtica dioica (ProstaMEV), quercitin and curcumin (FlogMEV) extracts associated with prulifloxacin in patients affected by chronic bacterial prostatitis (CBP). From a whole population of 284 patients, 143 patients affected by CBP [National Institutes of Health (NIH) class II prostatitis] were enrolled. All patients received prulifloxacin 600 mg daily for 14 days, in accordance with antibiogram results. Patients were split into two groups: Group A received prulifloxacin associated with ProstaMEV and FlogMEV; Group B received only antibiotic therapy. Microbiological and clinical efficacies were tested by two follow-up visits at 1 month and 6 months, respectively. Quality of life (QoL) was measured using the NIH Chronic Prostatitis Symptom Index (CPSI) and International Prostatic Symptom Score (IPSS) questionnaires. Group A comprised 106 patients and Group B comprised 37 patients. One month after treatment, 89.6% of patients who had received prulifloxacin associated with ProstaMEV and FlogMEV did not report any symptoms related to CBP, whilst only 27% of patients who received antibiotic therapy alone were recurrence-free (P < 0.0001). Significant differences were found between groups in terms of symptoms and QoL (P < 0.0001 for both). Six months after treatment, no patients in Group A had recurrence of disease whilst two patients in Group B did. Questionnaire results demonstrated statistically significant differences between groups (all P < 0.001). The association of S. repens, U. dioica (ProstaMEV), quercitin and curcumin (FlogMEV) extracts is able to improve the clinical efficacy of prulifloxacin in patients affected by CBP.

  17. Constraining the 6.05 MeV 0$^+$ and 6.13 MeV 3$^-$ cascade transitions in the $^{12}$C($\\alpha$,$\\gamma$)$^{16}$O reaction using the Asymptotic Normalization Coefficients

    CERN Document Server

    Avila, M L; Koshchiy, E; Baby, L T; Belarge, J; Kemper, K W; Kuchera, A N; Mukhamedzhanov, A M; Santiago-Gonzalez, D; Uberseder, E

    2014-01-01

    Background. The $^{12}$C($\\alpha,\\gamma$)$^{16}$O reaction plays a fundamental role in astrophysics because its cross section near 300 keV in c.m. determines the $^{12}$C/$^{16}$O ratio at the end of the helium burning stage of stellar evolution. The astrophysically desired accuracy of better than 10\\% has not been achieved. Cascade $\\gamma$ transitions through the excited states of $^{16}$O are contributing to the uncertainty. Purpose. To measure the Asymptotic Normalization Coefficients (ANCs) for the 0$^+$ (6.05 MeV) and 3$^-$ (6.13 MeV) excited states in $^{16}$O and provide constraints on the cross section for the corresponding cascade transitions. Method. The ANCs were measured using the $\\alpha$-transfer reaction $^{12}$C($^6$Li,$d$)$^{16}$O performed at sub-Coulomb energies for both the entrance and exit channels. Results. The ANCs for the 0$^+$(6.05 MeV), 3$^-$(6.13 MeV), 2$^+$(6.92 MeV) and 1$^-$(7.12 MeV) states in $^{16}$O have been measured. The contribution of the 0$^+$ and 3$^-$ cascade transit...

  18. Production of krypton and xenon isotopes in thick stony and iron targets isotropically irradiated with 1600 MeV protons

    National Research Council Canada - National Science Library

    Gilabert, E; Lavielle, B; Michel, R; Leya, I; Neumann, S; Herpers, U

    2002-01-01

    Abstract— Two spherical targets made of gabbro with a radius of 25 cm and of steel with a radius of 10 cm were irradiated isotropically with 1600 MeV protons at the SATURNE synchrotron at Laboratoire National Saturne (LNS...

  19. Range management visual impacts

    Science.gov (United States)

    Bruce R. Brown; David Kissel

    1979-01-01

    Historical overgrazing of western public rangelands has resulted in the passage of the Public Rangeland Improvement Act of 1978. The main purpose of this Act is to improve unsatisfactory range conditions. A contributing factor to unfavorable range conditions is adverse visual impacts. These visual impacts can be identified in three categories of range management: range...

  20. Design for a 1.3 MW, 13 MeV Beam Dump for an Energy Recovery Linac

    CERN Document Server

    Sinclair, Charles K; Smith, Colin H

    2005-01-01

    The electron beam exiting an Energy Recovery Linac (ERL) is dumped close to the injection energy. This energy is chosen as low as possible while allowing the beam quality specifications to be met. As ERLs are designed for high average beam current, beam dumps are required to handle high beam power at low energy. Low energy electrons have a short range in practical dump materials, requiring the beam size at the dump face be enlarged to give acceptable power densities and heat fluxes. Cornell University is developing a 100 mA average current ERL as a synchrotron radiation source. The 13 MeV optimum injection energy requires a 1.3 MW beam dump. We present a mature design for this dump, using an array of water-cooled extruded copper tubes. This array is mounted in the accelerator vacuum normal to the beam. Fatigue failure resulting from abrupt thermal cycles associated with beam trips is a potential failure mechanism. We report on designs for a 75 kW, 750 keV tube-cooled beryllium plate dump for electron gun test...

  1. Production of krypton and xenon isotopes in thick stony and iron targets isotropically irradiated with 1600 MeV protons

    CERN Document Server

    Gilabert, E; Lavielle, B; Leya, I; Michel, R; Neumann, S

    2002-01-01

    Two spherical targets made of gabbro with a radius of 25 cm and of steel with a radius of 10 cm were irradiated isotropically with 1600 MeV protons at the SATURNE synchrotron at Laboratoire National Saturne (LNS)/CEN Saclay, in order to simulate the production of nuclides in meteorites induced by galactic cosmic-ray protons in space. These experiments supply depth-dependent production rate data for a wide range of radioactive and stable isotopes in up to 28 target elements. In this paper, we report results for /sup 78/Kr, /sup 80-86/Kr isotopes in Rb, Sr, Y and Zr and for /sup 124/Xe, /sup 126/Xe, /sup 128-132/Xe, /sup 134/Xe, /sup 136/Xe isotopes in Ba and La. Krypton and xenon concentrations have been measured at different depths in the spheres by using conventional mass spectrometry. Based on Monte-Carlo techniques, theoretical production rates are calculated by folding depth-dependent spectra of primary and secondary protons and secondary neutrons with the excitation functions of the relevant nuclear reac...

  2. Defects in hyperpure Fe-based alloys created by 3 MeV e{sup -}-irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Li, X.H.; Moser, P. [CEA Centre d`Etudes de Grenoble, 38 (France). Dept. de Recherche Fondamentale sur la Matiere Condensee; Akamatsu, M.; Van Duysen, C. [Electricite de France (EDF), 77 - Ecuelles (France)

    1994-12-31

    Information about vacancy defects created in RPV (Reactor Pressure Vessels) steels after neutron irradiations are obtained via a simulation: the RPV steels are simulated by a series of high purity Fe-based alloys; the neutron irradiation is simulated by a 3 MeV electron irradiation; vacancy defects characteristics are obtained by positron lifetime techniques. Irradiations are made at 150 or 288 deg C, with a dose of 4*10{sup 19} e-/cm{sup 2}, and followed by isochronal annealing in the range 20-500 deg C. The observed vacancy defects are single trapped vacancies and small vacancy clusters, the size of which being lower than 10 empty atomic volumes (vacancy clusters containing more than 50 empty atomic volumes were never found). A large recovery step is observed between 200 and 400 deg C, after 150 deg C irradiation and attributed to vacancy-impurity detrapping, and also, vacancy cluster evaporation. The influence of C, Cu and Mo are presented. These results are in agreement with a model supposing, in pure Fe, single vacancy migration at -50 deg C and vacancy-impurity detrapping at 200 deg C. (authors). 4 figs., 15 refs.

  3. Towards 10 meV resolution: The design of an ultrahigh resolution soft X-ray RIXS spectrometer.

    Science.gov (United States)

    Dvorak, Joseph; Jarrige, Ignace; Bisogni, Valentina; Coburn, Scott; Leonhardt, William

    2016-11-01

    We present the optical design of the Centurion soft X-ray resonant inelastic X-ray scattering (RIXS) spectrometer to be located on the SIX beamline at NSLS-II. The spectrometer is designed to reach a resolving power of 100 000 at 1000 eV at its best resolution. It is also designed to have continuously variable 2θ motion over a range of 112° using a custom triple rotating flange. We have analyzed several possible spectrometer designs capable of reaching the target resolution. After careful analysis, we have adopted a Hettrick-Underwood spectrometer design, with an additional plane mirror to maintain a fixed direction for the outgoing beam. The spectrometer can cancel defocus and coma aberrations at all energies, has an erect focal plane, and minimizes mechanical motions of the detector. When the beamline resolution is accounted for, the net spectral resolution will be 14 meV at 1000 eV. This will open up many low energy excitations to study and will expand greatly the power of soft X-ray RIXS.

  4. Fission-fragment properties in 238U(n ,f ) between 1 and 30 MeV

    Science.gov (United States)

    Duke, D. L.; Tovesson, F.; Laptev, A. B.; Mosby, S.; Hambsch, F.-J.; Bryś, T.; Vidali, M.

    2016-11-01

    The fragment mass and kinetic energy in neutron-induced fission of 238U has been measured for incident energies from 1 to 30 MeV at the Los Alamos Neutron Science Center. The change in mass distributions over this energy range were studied, and the transition from highly asymmetric to more symmetric mass distributions is observed. A decrease in average total kinetic energy (TKE ¯) with increasing excitation energy is observed, consistent with previous experimental work. Additional structure at multichance fission thresholds is present in the TKE ¯ data. The correlations between fragment masses and total kinetic energy and how that changes with excitation energy of the fissioning compound nucleus were also measured. The fission mass yields and average total kinetic energy are important for fission-based technologies such as nuclear reactors to understand nuclear waste generation and energy output when developing new and advanced concepts. The correlations between fragment mass and kinetic energy are needed both as input for theoretical calculations of the deexcitation process in fission fragments by prompt radiation emission and for validating advanced theoretical fission models describing the formation of the primordial fragments.

  5. Excitation functions of proton induced reactions on natFe in the energy region up to 45 MeV

    Science.gov (United States)

    Kim, Kwangsoo; Khandaker, Mayeen Uddin; Naik, Haladhara; Kim, Guinyun

    2014-03-01

    The excitation functions of various reaction products such as 55,56,57Co, 52Fe, 52,54Mn, and 51Cr in the natFe(p, x) reactions were measured by the stacked-foil activation technique in the energy range between their respective reaction threshold and 45 MeV at the MC-50 cyclotron of the Korean Institute of Radiological and Medical Sciences, Korea. The present experimental data were compared with the existing literature data. It was found that excitation function of 56,57Co and 51Cr from the natFe(p, x) reaction are in agreement with the literature data. However, the cross-sections for natFe(p, x)52Fe reactions are lower and those for natFe(p, x)52Mn and natFe(p, x)54Mn reactions are higher than the literature data. The reaction cross-sections of the above mentioned reaction products were also compared with those from the TENDL-2012 library based on the TALYS-1.4 program as a function of proton energy, which was reproduced the trend of the excitation functions of the experimental natFe(p, x) reaction cross-section. The integral yields for thick target of the investigated radionuclides were calculated from the excitation function.

  6. Excitation functions of proton induced nuclear reactions on natW up to 40 MeV

    Science.gov (United States)

    Khandaker, M. U.; Uddin, M. S.; Kim, K.; Lee, M. W.; Kim, K. S.; Lee, Y. S.; Kim, G. N.; Cho, Y. S.; Lee, Y. O.

    2008-04-01

    We measured the excitation functions for the production of the 181,182m,182g,183,184g,186Re radioisotopes from proton bombardment of natural tungsten by using a stacked-foil activation technique in the energy range from threshold energy to 40 MeV at the MC50 cyclotron of the Korea Institute of Radiological and Medical Science. The results were compared with the earlier reported experimental data and the model calculations using codes TALYS and ALICE-IPPE. The present values are in good agreement with some of the previously reported literature. The integral yields for thick targets were also deduced from the measured excitation functions of the produced radioisotopes. The deduced yield values were compared with the available directly measured thick target yield, and found acceptable agreement. The investigated radioisotope 186Re has remarkable applications in the field of nuclear medicine, whereas the data of 183,184gRe have potential applications in thin layer activation analysis.

  7. Excitation function of ³He induced nuclear reactions on (nat)Pt up to 26 MeV.

    Science.gov (United States)

    Al-Abyad, M; Tárkányi, F; Ditrói, F; Takács, S

    2013-02-01

    The energy dependence of the cross-sections of (3)He-particle induced reactions on (nat)Pt targets was studied in the energy range from threshold up to 26 MeV, using a stacked-foil irradiation technique and classical gamma-spectroscopy. The formation of the radioisotopes via (nat)Pt((3)He,xn)(192)Hg, (nat)Pt((3)He,xn)(193 m,g)Hg, (nat)Pt((3)He,xn)(195m,g)Hg, (nat)Pt((3)He,xn)(197 m,g)Hg, (nat)Pt((3)He,xn)(199 m)Hg, (nat)Pt((3)He,pxn)(192,193,194,195,199,200 m)Au, (nat)Pt((3)He,pxn)(196 m,g)Au, (nat)Pt((3)He,pxn)(198 m,g)Au and (nat)Pt((3)He,2pxn)(197 m,199)Pt reactions were assessed. The obtained excitation functions were compared with the earlier published data and the theoretical model calculations by the codes ALICE-IPPE, EMPIRE-03, TALYS-1.4 and TENDL-2011 activation data library. Copyright © 2012 Elsevier Ltd. All rights reserved.

  8. Exclusive breakup of 7Li incident on a proton target at 5.44 A MeV

    Science.gov (United States)

    Pakou, A.; Sgouros, O.; Soukeras, V.; Cappuzzello, F.; Keeley, N.; Acosta, L.; Agodi, C.; Aslanoglou, X.; Calabrese, S.; Carbone, D.; Cavallaro, M.; Foti, A.; Marquínez-Durán, G.; Martel, I.; Mazzocco, M.; Parascandolo, C.; Pierroutsakou, D.; Rusek, K.; Strano, E.; Zagatto, V. A. B.; Zerva, K.

    2017-04-01

    An exclusive measurement of the breakup of 7Li incident on a proton target was performed at 38.1 MeV (5.44 MeV/nucleon), probing the direct part of the excitation to the continuum. The two cluster constituents of 7Li, 4He, and 3H, were recorded in coincidence in the MAGNEX spectrometer and a silicon detector respectively. Both detection systems were set at forward angles and the measurement of both kinematical solutions allowed the determination of a breakup angular distribution over a wide angular range in the center-of-mass frame. Comprehensive simulations provided the detection efficiency of the system and via the appropriate kinematics the transformation of the cross sections from the laboratory to the center-of-mass reference frame. The experimental results are analyzed and discussed together with previous elastic scattering data using the Continuum Discretized Coupled Channels (CDCC) framework and are found to be in satisfactory agreement. It was found that while the breakup cross section was dominated by the nonresonant component, the most important influence on the elastic scattering was due to coupling to the 7 /2- resonance of 7Li.

  9. Measurements of {sup 12}C (vector ({gamma}),pp) photon asymmetries for E{sub {gamma}} = 200-450 MeV

    Energy Technology Data Exchange (ETDEWEB)

    Robinson, J.; MacGregor, I.J.D.; Annand, J.R.M.; Codling, R.F.B.; Hamilton, D.; Howdle, D.; Livingston, K.; McGeorge, J.C.; McNicoll, E.F.; Owens, R.O.; Rosner, G. [University of Glasgow, SUPA, School of Physics and Astronomy, Glasgow (United Kingdom); Aguar-Bartolome, P.; Akasoy, L.K.; Arends, H.J.; Downie, E.J.; Drexler, P.; Heid, E.; Jahn, O.; Ostrick, M.; Otte, P.B.; Oussena, B.; Schumann, S.; Thomas, A.; Unverzagt, M. [University of Mainz, Institut fuer Kernphysik, Mainz (Germany); Azimov, Ya.I.; Bekrenev, V.S.; Koulbardis, A.A.; Kruglov, S.P. [Petersburg Nuclear Physics Institute, Gatchina (Russian Federation); Bantawa, K.; Manley, D.M. [Kent State University, Kent, Ohio (United States); Beck, R.; Nikolaev, A. [University of Bonn, Helmholtz-Institut fuer Strahlen- und Kernphysik, Bonn (Germany); Berghaeuser, H.; Gregor, R.; Kotulla, M.; Metag, V.; Novotny, R.; Thiel, M. [University of Giessen, II Physikalisches Institut, Giessen (Germany); Braghieri, A.; Mushkarenkov, A.; Pedroni, P.; Rostomyan, T. [INFN Sezione di Pavia, Pavia (Italy); Branford, D.; Glazier, D.I.; Jude, T.C.; Sikora, M.H.; Tarbert, C.M.; Watts, D.P. [University of Edinburgh, SUPA, School of Physics, Edinburgh (United Kingdom); Briscoe, W.J.; Demissie, B.T.; Strakovsky, I.I. [The George Washington University, Washington, DC (United States); Brudvik, J.; Nefkens, B.M.K.; Prakhov, S.; Starostin, A.; Suarez, I.M. [University of California Los Angeles, Los Angeles, California (United States); Cherepnya, S.; Fil' kov, L.V.; Kashevarov, V.L. [Lebedev Physical Institute, Moscow (Russian Federation); Dieterle, M.; Keshelashvili, I.; Krusche, B.; Oberle, M.; Werthmueller, D.; Witthauer, L. [University of Basel, Institut fuer Physik, Basel (Switzerland); Hornidge, D. [Mount Allison University, Sackville, New Brunswick (Canada); Kondratiev, R.; Lisin, V.; Polonski, A. [Institute for Nuclear Research, Moscow (Russian Federation); Korolija, M.; Supek, I. [Rudjer Boskovic Institute, Zagreb (Croatia); Middleton, D.G. [University of Mainz, Institut fuer Kernphysik, Mainz (Germany); Mount Allison University, Sackville, New Brunswick (Canada); Sober, D.I. [The Catholic University of America, Washington (United States); Collaboration: The Crystal Ball at MAMI and A2 Collaborations

    2013-05-15

    The {sup 12}C (vector ({gamma}),pp) reaction has been studied in the photon energy range 200-450 MeV at the Mainz microtron MAMI-C, where linearly polarised photons were energy-tagged using the Glasgow-Mainz Tagged Photon Spectrometer and protons were detected in the Crystal Ball detector. The photon asymmetry {Sigma} has been measured over a wider E{sub {gamma}} range than previous measurements. The strongest asymmetries were found at low missing energies where direct emission of nucleon pairs is expected. Cuts on the difference in azimuthal angles of the two ejected protons increased the magnitude of the observed asymmetries. At low missing energies the {Sigma} data exhibit a strong angular dependence, similar to deuteron photodisintegration. (orig.)

  10. Complete determination of neutron yield from 62 MeV protons on 9Be for the design of a low – power ADS

    Directory of Open Access Journals (Sweden)

    Schillaci Maria

    2014-03-01

    Full Text Available Within the European Partitioning & Transmutation research programs, infrastructures specifically dedicated to the study of fundamental reactor physics of future fast neutron-based reactors are very important. In this respect, an Accelerator Driven System low-power prototype, based on a 70 MeV proton beam impinging on a thick Beryllium converter, was recently proposed and designed within the INFN-E project. The world data on neutron yield from Be target are scarce in this proton energy range. This lack of data calls for a dedicated measurement which was performed at INFN Laboratori Nazionali del Sud, covering a wide angular range, from 0 to 150 degrees, and an almost complete neutron energy interval, from thermal up to the beam energy. In this contribution the results are discussed together with the description of the proposed ADS facility.

  11. Neutron emission in deep inelastic collisions of /sup 28/Si on /sup 64/Ni at 170 MeV

    Energy Technology Data Exchange (ETDEWEB)

    Manduchi, C.; Russo Manduchi, M.T.; Segato, G.F.; Tornielli, G.

    1989-06-01

    Energy and angular distributions of neutrons were measured in coincidence with the projectile-like fragments in deep inelastic collisions of /sup 28/Si on /sup 64/Ni at 170 MeV. Our data are consistent with the assumption of isotropic emission of neutrons in the rest frame of the fully accelerated fragments. Neutron multiplicities suggest that thermal equilibrium is not reached at least for energy losses of the system around 50 MeV.

  12. Near-Earth injection of MeV electrons associated with intense dipolarization electric fields: Van Allen Probes observations.

    Science.gov (United States)

    Dai, Lei; Wang, Chi; Duan, Suping; He, Zhaohai; Wygant, John R; Cattell, Cynthia A; Tao, Xin; Su, Zhenpeng; Kletzing, Craig; Baker, Daniel N; Li, Xinlin; Malaspina, David; Blake, J Bernard; Fennell, Joseph; Claudepierre, Seth; Turner, Drew L; Reeves, Geoffrey D; Funsten, Herbert O; Spence, Harlan E; Angelopoulos, Vassilis; Fruehauff, Dennis; Chen, Lunjin; Thaller, Scott; Breneman, Aaron; Tang, Xiangwei

    2015-08-16

    Substorms generally inject tens to hundreds of keV electrons, but intense substorm electric fields have been shown to inject MeV electrons as well. An intriguing question is whether such MeVelectron injections can populate the outer radiation belt. Here we present observations of a substorm injection of MeV electrons into the inner magnetosphere. In the premidnight sector at L ∼ 5.5, Van Allen Probes (Radiation Belt Storm Probes)-A observed a large dipolarization electric field (50 mV/m) over ∼40 s and a dispersionless injection of electrons up to ∼3 MeV. Pitch angle observations indicated betatron acceleration of MeV electrons at the dipolarization front. Corresponding signals of MeV electron injection were observed at LANL-GEO, THEMIS-D, and GOES at geosynchronous altitude. Through a series of dipolarizations, the injections increased the MeV electron phase space density by 1 order of magnitude in less than 3 h in the outer radiation belt ( L > 4.8). Our observations provide evidence that deep injections can supply significant MeV electrons.

  13. Measurement of the e+e−→π+π− cross section between 600 and 900 MeV using initial state radiation

    Directory of Open Access Journals (Sweden)

    M. Ablikim

    2016-02-01

    Full Text Available We extract the e+e−→π+π− cross section in the energy range between 600 and 900 MeV, exploiting the method of initial state radiation. A data set with an integrated luminosity of 2.93 fb−1 taken at a center-of-mass energy of 3.773 GeV with the BESIII detector at the BEPCII collider is used. The cross section is measured with a systematic uncertainty of 0.9%. We extract the pion form factor |Fπ|2 as well as the contribution of the measured cross section to the leading-order hadronic vacuum polarization contribution to (g−2μ. We find this value to be aμππ,LO(600–900MeV=(368.2±2.5stat±3.3sys⋅10−10, which is between the corresponding values using the BaBar or KLOE data.

  14. Extension of activation cross section data of long lived products in deuteron induced nuclear reactions on platinum up to 50 MeV

    Energy Technology Data Exchange (ETDEWEB)

    Ditrói, F., E-mail: ditroi@atomki.hu [Institute for Nuclear Research, Hungarian Academy of Sciences, Debrecen (Hungary); Tárkányi, F.; Takács, S. [Institute for Nuclear Research, Hungarian Academy of Sciences, Debrecen (Hungary); Hermanne, A. [Cyclotron Laboratory, Vrije Universiteit Brussel, Brussels (Belgium)

    2017-06-15

    Highlights: • Deuteron induced nuclear reactions on natural platinum up to 50 MeV. • Stacked foil irradiation technique. • Comparison with the TENDL-2014 and TENDL-2015 calculations. • Cross section of Au, Pt and Ir radioisotopes. • Application for Thin Layer Activation (TLA). - Abstract: In the frame of a systematical study of light ion induced nuclear reactions on platinum, activation cross sections for deuteron induced reactions were investigated. Excitation functions were measured in the 20.8–49.2 MeV energy range for the {sup nat}Pt(d,xn){sup 191,192,193,194,195,196m2,196g,198g,199}Au, {sup nat}Pt(d,x){sup 188,189,191,195m,197m,197g}Pt and {sup nat}Pt(d,x){sup 189,190,192,194m2}Ir reactions by using the stacked foil irradiation technique. The experimental results are compared with previous results from the literature and with the theoretical predictions in the TENDL-2014 and TENDL-2015 libraries. The applicability of the produced radio-tracers for wear measurements has been presented.

  15. Depth profiles of production yields of natPb(p, xn206,205,204,203,202 Bi reactions using 100-MeV proton beam

    Directory of Open Access Journals (Sweden)

    Oranj Leila Mokhtari

    2017-01-01

    Full Text Available In this study, results of the experimental study on the depth profiles of production yields of 206,205,204,203,202Bi radio-nuclei in the natural Pb target irradiated by a 100-MeV proton beam are presented. Irradiation was performed at proton linac facility (KOMAC in Korea. The target, irradiated by 100-MeV protons, was arranged in a stack consisting of natural Pb, Al, Au foils and Pb plates. The proton beam intensity was determined by activation analysis method using 27Al(p, 3p1n24Na, 197Au(p, p1n196Au, and 197Au(p, p3n194Au monitor reactions and also using dosimetry method by a Gafchromic film. The production yields of produced Bi radio-nuclei in the natural Pb foils and monitor reactions were measured by gamma-ray spectroscopy. Monte Carlo simulations were performed by FLUKA, PHITS, and MCNPX codes and compared with the measurements in order to verify validity of physical models and nuclear data libraries in the Monte Carlo codes. A fairly good agreement was observed between the present experimental data and the simulations by FLUKA, PHITS, and MCNPX. However, physical models and the nuclear data relevant to the end of range of protons in the codes need to be improved.

  16. Elastic and inelastic neutron scattering cross sections for 12C at En = 5.9, 6.1, and 7.0 MeV

    Science.gov (United States)

    Lyons, Elizabeth; Hicks, Sally; Morin, Theodore; Derdeyn, Elizabeth; Peters, Erin

    2017-09-01

    Measurements of neutron elastic and inelastic scattering differential cross sections from 12C have been performed at incident neutron energies of 5.9, 6.1, and 7.0 MeV. Comparisons of existing experimental cross sections (NNDC) at these incident neutron energies reveal large discrepancies. Accurate measurements of 12C cross sections are vital to facilitate precise calculations regarding criticality conditions for nuclear reactors, advances in security screening methods, and better understanding astrophysical and nuclear phenomenon. During preliminary measurements of 12C cross sections at the University of Kentucky Accelerator Laboratory (UKAL), we realized the relative efficiency of the deuterated benzene (main) detector was needed over an unusually large range of neutron energies due to the high Q value of the first excited state of 12C. Those experiments were repeated during the summer of 2017 to measure in situ the relative detector efficiency with better beam conditions and a better understanding of background observed from the 2H(d, n)3He source reaction. The resulting improved detector efficiency was used in determining the neutron elastic and inelastic scattering cross sections. While the former were found to be in excellent agreement with evaluated cross sections from ENDF, the latter show some discrepancies, especially at 6.1 MeV. Our results will be presented. Research is supported by USDOE-NNSA-SSAP: NA0002931, NSF: PHY-1606890, and the Donald A. Cowan Physics Institute at the University of Dallas.

  17. Energy measurement of prompt fission neutrons in 239Pu(n,f) for incident neutron energies from 1 to 200 MeV

    Energy Technology Data Exchange (ETDEWEB)

    Haight, Robert C [Los Alamos National Laboratory; Devlin, Matthew J [Los Alamos National Laboratory; Nelson, Ronald O [Los Alamos National Laboratory; O' Donnell, John M [Los Alamos National Laboratory; Chatillon, Audrey [CEA, FRANCE; Granier, Thierry [CEA, FRANCE; Taieb, Julien [CEA, FRANCE; Belier, Gilbert [CEA, FRANCE; Laurent, Benoit [CEA, FRANCE; Noda, Shusaku [KYUSHU UNIV, JAPAN

    2010-01-01

    An experimental campaign was started in 2002 in the framework of a collaboration belween CEA-DAM and the Los Alamos National Laboratory to measure the prompt fission neutron spectra (PFNS) for incident neutron energies from 1 to 200 MeV with consistent error uncertainties over the whole energy range. The prompt neutron spectra in {sup 235,238}U(n,f) and {sup 237}Np(n,f) have been already studied successfully. A first attempt to characterize the prompt neutrons emitted during the fission of the {sup 239}Pu was done in 2007. This contribution will focus on the results obtained during the final experiment to measure the PFNS in {sup 239}Pu(n,f) performed in 2008. Prompt fission neutron spectra in the neutron-induced fission of {sup 239}Pu have been measured for incident neutron energies from 1 to 200 MeV at the Los Alamos Neutron Science Center. Mean energies obtained from the spectra are discussed and compared to theoretical model calculation.

  18. Formation of 60Cu and 61Cu via Co + 3He reactions up to 70 MeV: production possibility of 60Cu for PET studies

    Science.gov (United States)

    Szelecsényi, F.; Kovács, Z.; Suzuki, K.; Okada, K.; Fukumura, T.; Mukai, K.

    2004-08-01

    Excitation functions for 60Cu and 61Cu radioactive nuclei produced in 3He bombardment of 59Co up to 70 MeV has been measured using the stacked-foil activation technique. The experimental cross-sections of the 59Co( 3He,2n) 60Cu and 59Co( 3He,n) 61Cu nuclear reactions were compared with published literature data. Our yield calculations with respect to the application of the above reactions for practical production of 60Cu showed that around 3.1 mCi/μA 60Cu yield is available at EOB in the energy range 26 → 10 MeV (supposing one half-life of 60Cu activation time). Unfortunately, the level of 61Cu impurity increases continuously after EOB (1.4% at EOB), but remains around 4% even at the end of a PET study (supposing one half-live cooling (processing) time and around 20 min counting time with PET). On the bases of the present work the Co + 3He route seems to be a good candidate for routine production of 60Cu even with a low energy multiparticle cyclotron.

  19. Excitation functions of proton induced reactions on {sup nat}Os up to 65 MeV: Experiments and comparison with results from theoretical codes

    Energy Technology Data Exchange (ETDEWEB)

    Hermanne, A.; Adam Rebeles, R. [Cyclotron Laboratory, Vrije Universiteit Brussel, Brussels 1090 (Belgium); Tárkányi, F.; Takács, S. [Institute of Nuclear Research, Hungarian Academy of Science, 4026 Debrecen (Hungary)

    2015-02-15

    Activation of thin {sup nat}Os targets, electrodeposited on Ni backings, was investigated for the first time in stacked foil irradiations with 65 MeV and 34 MeV proton beams. Assessments of the produced radionuclides by high resolution gamma-ray spectroscopy yielded excitation functions for formation of {sup 184,} {sup 185,} {sup 186m,m+g,} {sup 187m+g,} {sup 188m+g,} {sup 189m2+m1+g,} {sup 190m2,m1+g,} {sup 192m1+g}Ir and {sup 185cum,} {sup 191m+g}Os, {sup 183m+g}Re. Where available comparisons with the reaction cross sections obtained in 2 earlier studies on enriched {sup 192}Os were made. Reduced uncertainty on cross sections is obtained by simultaneous remeasurement of the {sup 27}Al(p,x){sup 22,24}Na, {sup nat}Ni(p,x){sup 57}Ni and {sup nat}Ti(p,x){sup 48}V monitor reactions over wide relevant energy ranges. Confirmation of monitoring took place by assessment of excitation functions of {sup 61}Cu, {sup 56}Ni, {sup 55,56,57,58}Co and {sup 52}Mn induced in the Ni backings and comparison with a recent compilation for most of these radionuclides. Contributing reactions and overall cross sections are discussed and were evaluated in comparison with the results of the theoretical code TALYS 1.6 (values from the on-line library TENDL-2013)

  20. Angular distribution and recoil effect for 1 MeV Au{sup +} ions through a Si{sub 3}N{sub 4} thin foil

    Energy Technology Data Exchange (ETDEWEB)

    Jin, Ke [Department of Materials Science and Engineering, University of Tennessee, Knoxville, TN 37996 (United States); Zhu, Zihua, E-mail: zihua.zhu@pnnl.gov [Environmental Molecular Sciences Laboratory, Pacific Northwest National Laboratory, P.O. Box 999, Richland, WA 99352 (United States); Manandhar, Sandeep; Liu, Jia [Environmental Molecular Sciences Laboratory, Pacific Northwest National Laboratory, P.O. Box 999, Richland, WA 99352 (United States); Chen, Chien-Hung [Department of Materials Science and Engineering, University of Tennessee, Knoxville, TN 37996 (United States); Shutthanandan, Vaithiyalingam; Thevuthasan, Suntharampillai [Environmental Molecular Sciences Laboratory, Pacific Northwest National Laboratory, P.O. Box 999, Richland, WA 99352 (United States); Weber, William J. [Department of Materials Science and Engineering, University of Tennessee, Knoxville, TN 37996 (United States); Materials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831 (United States); Zhang, Yanwen, E-mail: Zhangy1@ornl.gov [Materials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831 (United States); Department of Materials Science and Engineering, University of Tennessee, Knoxville, TN 37996 (United States)

    2014-08-01

    The Stopping and Range of Ions in Matter (SRIM) code has been widely used to predict nuclear stopping power and angular distribution of ion–solid collisions. However, experimental validation of the predictions is insufficient for slow heavy ions in nonmetallic compounds. In this work, time-of-flight secondary ion mass spectrometry (ToF-SIMS) is applied to determine the angular distribution of 1 MeV Au ions after penetrating a Si{sub 3}N{sub 4} foil with a thickness of ∼100 nm. The exiting Au ions are collected by a Si wafer located ∼14 mm behind the Si{sub 3}N{sub 4} foil, and the resulting 2-dimensional distribution of Au ions on the Si wafer is measured by ToF-SIMS. The SRIM-predicted angular distribution of Au ions through the Si{sub 3}N{sub 4} thin foil is compared with the measured results, indicating that SRIM slightly overestimates the nuclear stopping power by up to 10%. In addition, thickness reduction of the suspended Si{sub 3}N{sub 4} foils induced by 1 MeV Au ion irradiation is observed with an average loss rate of ∼107 atoms/ion.

  1. Increasing diterpene yield with a modular metabolic engineering system in E. coli: comparison of MEV and MEP isoprenoid precursor pathway engineering.

    Science.gov (United States)

    Morrone, Dana; Lowry, Luke; Determan, Mara K; Hershey, David M; Xu, Meimei; Peters, Reuben J

    2010-02-01

    Engineering biosynthetic pathways in heterologous microbial host organisms offers an elegant approach to pathway elucidation via the incorporation of putative biosynthetic enzymes and characterization of resulting novel metabolites. Our previous work in Escherichia coli demonstrated the feasibility of a facile modular approach to engineering the production of labdane-related diterpene (20 carbon) natural products. However, yield was limited (pathway (MEV) or enhancement of the endogenous methyl erythritol phosphate pathway (MEP) with our modular metabolic engineering system. With MEP pathway enhancement, it was found that pyruvate supplementation of rich media and simultaneous overexpression of three genes (idi, dxs, and dxr) resulted in the greatest increase in diterpene yield, indicating distributed metabolic control within this pathway. Incorporation of a heterologous MEV pathway in bioreactor grown cultures resulted in significantly higher yields than MEP pathway enhancement. We have established suitable growth conditions for diterpene production levels ranging from 10 to >100 mg/L of E. coli culture. These amounts are sufficient for nuclear magnetic resonance analyses, enabling characterization of enzymatic products and hence, pathway elucidation. Furthermore, these results represent an up to >1,000-fold improvement in diterpene production from our facile, modular platform, with MEP pathway enhancement offering a cost effective alternative with reasonable yield. Finally, we reiterate here that this modular approach is expandable and should be easily adaptable to the production of any terpenoid natural product.

  2. Investigation of (d,x) nuclear reactions on natural ytterbium up to 24 MeV

    Energy Technology Data Exchange (ETDEWEB)

    Khandaker, Mayeen Uddin, E-mail: mu_khandaker@um.edu.my [Department of Physics, University of Malaya, 50603 Kuala Lumpur (Malaysia); Haba, Hiromitsu [Nishina Center for Accelerator-Based Science, RIKEN, Wako, Saitama 351-0198 (Japan); Otuka, Naohiko [Nuclear Data Section, Division of Physical and Chemical Sciences, Department of Nuclear Sciences and Applications, International Atomic Energy Agency, A-1400 Vienna (Austria); Usman, Ahmed Rufa’i [Department of Physics, University of Malaya, 50603 Kuala Lumpur (Malaysia)

    2014-09-15

    Production cross-sections of the {sup nat}Yb(d,x){sup 169,170,171,172,173,174m,174,176m,177g}Lu and {sup 169,175,177}Yb reactions have been measured from a 24-MeV deuteron energy down to their respective thresholds by using a stacked-foil activation technique combined with high resolution γ-ray spectrometry. Our new experimental data extended the experimental database toward the lower energy region for {sup 169}Yb, {sup 171}Lu, {sup 172}Lu, and {sup 176m}Lu, and the higher region for {sup 174}Lu, {sup 176m}Lu, and {sup 177}Yb. An overall good agreement is found with some of the earlier measurements, whereas a partial agreement is obtained with the theoretical data extracted from the TENDL-2013 library. The (d,p) channel contribution underestimated by the TENDL-2013 library is successfully reproduced in the global renormalization by Ignatyuk for the FENDL-3.0 library. The production cross-sections of {sup 175}Yb available in the literature were revised based on the latest γ-ray intensity adopted in 2004. Physical thick target yields for the investigated reaction products were also deduced and compared with the directly measured ones in the literature. The derived thick target yields for {sup 173}Lu and {sup 174g}Lu are higher than the directly measured ones by Dmitriev et al. at 22 MeV. The deduced yield curves indicate that a low energy (<11 MeV) cyclotron and a highly enriched {sup 176}Yb target could be used to obtain {sup 177g}Lu with negligible impurity from {sup 177m}Lu.

  3. Determining the Effects of EMIC Waves on Precipitating MeV Electrons during Strom Main Phases

    Science.gov (United States)

    Chen, Y.

    2015-12-01

    Theoretic studies have suggested that electromagnetic ion cyclotron (EMIC) waves can cause significant precipitation of ~MeV electrons, supposedly accounting for the fast dropouts of outer-belt electrons during storm main phases. Usually the resonance between left-hand polarized EMIC with electrons with moderate energy is unlikely due to their opposite polarizations, while resonance with highly relativistic electrons do occur and cause electrons to precipitate into the atmosphere through pitch-angle scattering. Several previous studies on observations find a close relation between the two phenomena, e.g., Cliverd et al. [2007], Sandanger et al. [2007], and Miyoshi et al. [2008], while others find otherwise, e.g., Meredith et al. [2011]; recently, more observational evidence supporting the connection has been reported (e.g., Li et al. [2014] and Blum et al. [2015]). However, whether and under what favoring conditions EMIC waves cause rapid dropouts of relativistic electrons during storm main phases remain unresolved questions. Here, using latest wave and electron data from multiple missions including Van Allen Probes, BARREL, and NOAA POES, we systemically examine the relation between EMIC waves and MeV electron precipitation. We first construct two independent event lists for intensified EMIC waves and enhancements of MeV electron precipitation, respectively. Then we cross check the two lists to identify if any significant correlation exists in between, and further characterize the wave effectiveness in terms of L-shell, MLT, resonance energy, as well as the background plasma conditions. Results from this study will advance our knowledge about the loss mechanism of outer-belt electrons, thus laying down another stepping stone towards high-fidelity physics-based models for radiation belts.

  4. Investigation of (d,x) nuclear reactions on natural ytterbium up to 24 MeV

    Science.gov (United States)

    Khandaker, Mayeen Uddin; Haba, Hiromitsu; Otuka, Naohiko; Usman, Ahmed Rufa'i.

    2014-09-01

    Production cross-sections of the natYb(d,x)169,170,171,172,173,174m,174,176m,177gLu and 169,175,177Yb reactions have been measured from a 24-MeV deuteron energy down to their respective thresholds by using a stacked-foil activation technique combined with high resolution γ-ray spectrometry. Our new experimental data extended the experimental database toward the lower energy region for 169Yb, 171Lu, 172Lu, and 176mLu, and the higher region for 174Lu, 176mLu, and 177Yb. An overall good agreement is found with some of the earlier measurements, whereas a partial agreement is obtained with the theoretical data extracted from the TENDL-2013 library. The (d,p) channel contribution underestimated by the TENDL-2013 library is successfully reproduced in the global renormalization by Ignatyuk for the FENDL-3.0 library. The production cross-sections of 175Yb available in the literature were revised based on the latest γ-ray intensity adopted in 2004. Physical thick target yields for the investigated reaction products were also deduced and compared with the directly measured ones in the literature. The derived thick target yields for 173Lu and 174gLu are higher than the directly measured ones by Dmitriev et al. at 22 MeV. The deduced yield curves indicate that a low energy (<11 MeV) cyclotron and a highly enriched 176Yb target could be used to obtain 177gLu with negligible impurity from 177mLu.

  5. The monitor system of the 7 MeV proton linac at ICR

    Science.gov (United States)

    Iwashita, Y.; Kando, M.; Ikegami, M.; Dewa, H.; Shirai, T.; Kakigi, S.; Fujita, H.; Noda, A.; Inoue, M.

    1995-05-01

    The beam monitor system at ICR 7 MeV proton linac is described. Because of the pulsed beam (flipped away by an electromagnetic actuator installed in the vacuum vessel. With this view screen, an emittance monitor is constructed. The beam current can be measured non-destructively by a core monitor. Because the pulse length is rather long (˜50 μs), a special preamplifier using Negative Impedance Converter is designed. Very thin steering magnet with eight poles is also developed to compensate the deflection of the output beam.

  6. Search for a neutral particle of mass 33.9 MeV in pion decay

    Energy Technology Data Exchange (ETDEWEB)

    Daum, M. [Paul Scherrer Inst. (PSI), Villigen (Switzerland)

    1996-11-01

    We have measured the muon momentum distribution in charged pion decay in flight in order to search for a small branching fraction {eta} of pion decays {pi}{sup +}{yields}{mu}{sup +} 1 X, in which a heavy neutral particle X with a mass of 33.9 MeV would be emitted. Such a particle was postulated by the KARMEN collaboration as a possible explanation for an anomaly in their time-of-flight spectrum. In a first experiment we found an upper limit of {eta}{<=}2.6.10{sup -8} at a confidence level of 95%. (author) 4 figs., 9 refs.

  7. Determination of alumina in sintered aluminium powder by activation with 14-MeV neutrons.

    Science.gov (United States)

    Español, C E; Marafuschi, A M

    1970-07-01

    Fast neutrons of 14 MeV produced in the IMICAM CISE 150-kV generator by the (d, t) reaction in a tritium-titanium target, were used in the indirect determination of Al(2)O(3). The samples were irradiated for 30 sec and the total (16)N activity was determined, by counting for ten 2-sec periods and graphically integrating. The standards were a known sintered aluminium powder and nylon pieces of identical shape. The method is competitive with the chemical one, because of its quickness, sensitivity and precision.

  8. Cross section measurement for (n,n{alpha}) reactions by 14 MeV neutrons

    Energy Technology Data Exchange (ETDEWEB)

    Kasugai, Y.; Ikeda, Y.; Uno, Y. [Japan Atomic Energy Research Inst., Naka, Ibaraki (Japan). Naka Fusion Research Establishment; Yamamoto, H.; Kawade, K.

    1997-03-01

    Nine (n,n{alpha}) cross sections for (n,n{alpha}) reactions induced by 13.5-14.9 MeV neutrons were measured for {sup 51}V, {sup 65}Cu, {sup 71}Ga, {sup 76}Ge, {sup 87}Rb, {sup 91}Zr, {sup 93}Nb, {sup 96}Zr and {sup 109}Ag isotopes by using Fusion Neutronics Source (FNS) at JAERI. The reactions for 91Zr and 96Zr were measured for the first time. The evaluated data of JENDL-3 and ENDF/B-VI were compared with the present data. Some of the evaluated values are much different from our data by a factor more than ten. (author)

  9. Model of Dees and Rotco for the 600 MeV SC

    CERN Multimedia

    CERN PhotoLab

    1978-01-01

    The accelerating frequency of the 600 MeV Synchro-Cyclotron (SC) was modulated by the varying capacity of a rotating condenser ("Rotco", the most delicate component of the SC). A 1/5-scale model, dating from the design-period of the SC, was used to study improvements to the SC RF-system, and also the acceleration of ions, first Helium and, at the time of this picture, Carbon. In the middle of the picture is the case containing the Dees. To the left, at the wide end of the cone, a rotco. Reinhold Hohbach is busy with measurements. See also 7805235 (Annual Report 1978, p.110).

  10. Focussed ion beam lithography using a MeV proton beam microprobe for microoptics fabrication

    Energy Technology Data Exchange (ETDEWEB)

    Mason, L.M.; Roberts, A.; Jamieson, D.N.; Saint, A.

    1995-10-01

    Deep, high-aspect ratio trenches have been fabricated in the resist polymethyl methacrylate by exposure to a focussed beam of MeV protons followed by development. The depth of the trenches depends on the energy of the protons and simulations suggest that this can be up to 300 {mu}m. The University of Melbourne Microprobe is capable of producing a focussed spot size of the order of a few microns. This opens up the possibility of fabrication extremely high-aspect ratio microstructures for use as optical components. 9 refs., 3 figs.

  11. Evaporation residues at E ∗≈400 MeV

    Science.gov (United States)

    Beiersdorf, S.; Esterlund, R. A.; Knaack, M.; Westmeier, W.; Patzelt, P.; Heßberger, F. P.; Ninov, V.; Lüttgen, A.

    1992-07-01

    For the reaction 11.4 MeV/u 86Kr+ 104Ru, which leads to the compound nucleus 190Hg ∗ at an excitation energy of 396 MeV, we have measured a total evaporation-residue yield of 25±3 mb. As a pure Bohr-Wheeler fission-evaporation calculation for this system predicts σER < 1 × 10 -4 mb, we postulate that the highly-excited compound nuclei here decay initially by particle emission only, due to dynamic hindrance of the fission process, thereby enhancing the evaporation-residue yield for this system by over five orders of magnitude.

  12. A simple thick target for production of 89Zr using an 11 MeV cyclotron

    Science.gov (United States)

    Link, Jeanne M.; Krohn, Kenneth A.; O’Hara, Matthew J.

    2017-01-01

    The growing interest but limited availability of 89Zr for PET led us to test targets for the 89Y(p,n) reaction. The goal was an easily constructed target for an 11 MeV Siemens cyclotron. Yttrium foils were tested at different thicknesses, angles and currents. A 90° foil tolerated 41 μA without damage and produced ~800 MBq/h, > 20 mCi, an amount adequate for radiochemistry research and human doses in a widely available accelerator. This method should translate to higher energy cyclotrons. PMID:28187357

  13. Nuclear excitation functions from 40 to 200 MeV proton irradiation of terbium

    Energy Technology Data Exchange (ETDEWEB)

    Engle, Jonathan W., E-mail: jwengle@lanl.gov; Mashnik, Stepan G.; Parker, Lauren A.; Jackman, Kevin R.; Bitteker, Leo J.; Ullmann, John L.; Gulley, Mark S.; Pillai, Chandra; John, Kevin D.; Birnbaum, Eva R.; Nortier, Francois M.

    2016-01-01

    Nuclear formation cross sections are reported for 26 radionuclides, measured with 40–200 MeV proton irradiations of terbium foils. These data provide the basis for the production of medically relevant radionuclides (e.g., {sup 152}Tb, {sup 155}Tb, {sup 155}Eu, and {sup 156}Eu) and {sup 153}Gd, a potential source used in ongoing efforts to characterize stellar nucleosynthesis routes. Computational predictions from the ALICE2011, CEM03.03, Bertini, and INCL + ABLA codes are compared with newly measured data to contribute to the ongoing process of code development, and yields are calculated for selected radionuclides using measured data.

  14. Dosimetric characterization of CVD diamonds irradiated with 62 MeV proton beams

    Energy Technology Data Exchange (ETDEWEB)

    Cirrone, G.A.P. [Laboratori Nazionali del Sud, INFN, Catania (Italy)]. E-mail: cirrone@lns.infn.it; Cuttone, G. [Laboratori Nazionali del Sud, INFN, Catania (Italy); Lo Nigro, S. [Laboratori Nazionali del Sud, INFN, Catania (Italy); Dipartimento di Fisica ed Astronomia, Universita di Catania (Italy); CSFNSM Centro Siciliano di Fisica Nucleare e Struttura della MAteria, Catania (Italy); Mongelli, V. [Laboratori Nazionali del Sud, INFN, Catania (Italy); Scuola di Specializzazione in Fisica Sanitaria, Universita di Catania (Italy); CSFNSM Centro Siciliano di Fisica Nucleare e Struttura della MAteria, Catania (Italy); Raffaele, L. [Laboratori Nazionali del Sud, INFN, Catania (Italy); Sabini, M.G. [Laboratori Nazionali del Sud, INFN, Catania (Italy); Azienda Ospedaliera Cannizzaro, Catania (Italy); Valastro, L. [Laboratori Nazionali del Sud, INFN, Catania (Italy); Scuola di Specializzazione in Fisica Sanitaria, Universita di Catania (Italy); Bucciolini, M. [Dipartimento di Fisiopatologia Clinica, Universita di Florence (Italy); Onori, S. [Istituto Superiore di Sanita, Rome (Italy)

    2005-10-21

    Diamond is potentially a very suitable material for use as on-line radiation dosimeter. Recent advances in the synthesis of polycrystalline diamond by chemical vapor deposition (CVD) techniques have produced material with electronic properties suitable for dosimetry applications. In this work the possibility to use a segmented commercial CVD detector in the dosimetry of proton beams has been investigated. The response as function of dose, dose rate, the priming and the rise time have been investigated thoroughly. This study shows the suitability of CVD diamond for dosimetry of clinical 62 MeV proton beams.

  15. A diamond 14 MeV neutron energy spectrometer with high energy resolution

    Energy Technology Data Exchange (ETDEWEB)

    Shimaoka, Takehiro, E-mail: t.shimaoka@eng.hokudai.ac.jp; Kaneko, Junichi H.; Tsubota, Masakatsu; Shimmyo, Hiroaki [Graduate School of Engineering, Hokkaido University, Kita 13, Nishi 8, Kita-ku, Sapporo, Hokkaido 060-8628 (Japan); Ochiai, Kentaro [Fusion Research and Development Directorate, Japan Atomic Energy Agency, Tokai-mura, Naka-gun, Ibaraki 319-1195 (Japan); Chayahara, Akiyoshi; Umezawa, Hitoshi; Shikata, Shin-ichi [National Institute of Advanced Industrial Science and Technology (AIST), 1-8-31 Midorigaoka, Ikeda, Osaka 563-8577 (Japan); Watanabe, Hideyuki [National Institute of Advanced Industrial Science and Technology, 1-1-1 Higashi, Tsukuba, Ibaraki 305-8565 (Japan); Isobe, Mitsutaka; Osakabe, Masaki [National Institute for Fusion Science, 322-6, Oroshi-cho, Toki-City, Gifu 509-5292 (Japan)

    2016-02-15

    A self-standing single-crystal chemical vapor deposited diamond was obtained using lift-off method. It was fabricated into a radiation detector and response function measurements for 14 MeV neutrons were taken at the fusion neutronics source. 1.5% of high energy resolution was obtained by using the {sup 12}C(n, α){sup 9}Be reaction at an angle of 100° with the deuteron beam line. The intrinsic energy resolution, excluding energy spreading caused by neutron scattering, slowing in the target and circuit noises was 0.79%, which was also the best resolution of the diamond detector ever reported.

  16. Gamma-ray-spectroscopy following high-flux 14-MeV neutron activation

    Energy Technology Data Exchange (ETDEWEB)

    Williams, R.E.

    1981-10-12

    The Rotating Target Neutron Source (RTNS-I), a high-intensity source of 14-MeV neutrons at the Lawrence Livermore National Laboratory (LLNL), has been used for applications in activation analysis, inertial-confinement-fusion diagnostic development, and fission decay-heat studies. The fast-neutron flux from the RTNS-I is at least 50 times the maximum fluxes available from typical neutron generators, making these applications possible. Facilities and procedures necessary for gamma-ray spectroscopy of samples irradiated at the RTNS-I were developed.

  17. Technical preparations for the in-vessel 14 MeV neutron calibration at JET

    Energy Technology Data Exchange (ETDEWEB)

    Batistoni, P., E-mail: paola.batistoni@enea.it [ENEA, Department of Fusion and Nuclear Safety Technology, I-00044, Frascati, Rome (Italy); EUROfusion Consortium, Culham Science Centre, Abingdon, Oxon, OX14 3DB (United Kingdom); Popovichev, S. [CCFE, Culham Science Centre, Abingdon, Oxon, OX14 3DB (United Kingdom); EUROfusion Consortium, Culham Science Centre, Abingdon, Oxon, OX14 3DB (United Kingdom); Crowe, R. [Remote Applications in Challenging Environments (RACE), Culham Science Centre, Abingdon, Oxon, OX14 3DB (United Kingdom); EUROfusion Consortium, Culham Science Centre, Abingdon, Oxon, OX14 3DB (United Kingdom); Cufar, A. [Reactor Physics Division, Jožef Stefan Institute, Jamova cesta 39, SI-1000, Ljubljana (Slovenia); EUROfusion Consortium, Culham Science Centre, Abingdon, Oxon, OX14 3DB (United Kingdom); Ghani, Z. [CCFE, Culham Science Centre, Abingdon, Oxon, OX14 3DB (United Kingdom); EUROfusion Consortium, Culham Science Centre, Abingdon, Oxon, OX14 3DB (United Kingdom); Keogh, K. [Remote Applications in Challenging Environments (RACE), Culham Science Centre, Abingdon, Oxon, OX14 3DB (United Kingdom); EUROfusion Consortium, Culham Science Centre, Abingdon, Oxon, OX14 3DB (United Kingdom); Peacock, A. [JET Exploitation Unit, Abingdon, Oxon, OX14 3DB (United Kingdom); Price, R. [Remote Applications in Challenging Environments (RACE), Culham Science Centre, Abingdon, Oxon, OX14 3DB (United Kingdom); EUROfusion Consortium, Culham Science Centre, Abingdon, Oxon, OX14 3DB (United Kingdom); Baranov, A.; Korotkov, S.; Lykin, P.; Samoshin, A. [All-Russia Research Institute of Automatics (VNIIA), 22, Sushchevskaya str., 127055, Moscow (Russian Federation)

    2017-04-15

    Highlights: • The JET 14 MeV neutron calibration requires a neutron generator to be deployed inside the vacuum vessel by means of the remote handling system. • A neutron generator of suitable intensity and compliant with physics, remote handling and safety requirements has been identified and procured.The scientific programme of the preparatory phase devoted to fully characterizing the selected 14 MeV neutron generator is discussed. • The aim is to measure the absolute neutron emission rate within (± 5%) and the energy spectrum of emitted neutron as a function of angles. • The physics preparations, source issues, safety and engineering aspects required to calibrate directly the JET neutron detectors are discussed. - Abstract: The power output of fusion devices is measured from their neutron yields which relate directly to the fusion yield. In this paper we describe the devices and methods that have been prepared to perform a new in situ 14 MeV neutron calibration at JET in view of the new DT campaign planned at JET in the next years. The target accuracy of this calibration is ±10% as required for ITER, where a precise neutron yield measurement is important, e.g., for tritium accountancy. In this paper, the constraints and early decisions which defined the main calibration approach are discussed, e.g., the choice of 14 MeV neutron source and the deployment method. The physics preparations, source issues, safety and engineering aspects required to calibrate directly the JET neutron detectors are also discussed. The existing JET remote-handling system will be used to deploy the neutron source inside the JET vessel. For this purpose, compatible tooling and systems necessary to ensure safe and efficient deployment have been developed. The scientific programme of the preparatory phase is devoted to fully characterizing the selected 14 MeV neutron generator to be used as the calibrating source, obtain a better understanding of the limitations of the

  18. Physics design of the CIADS 25 MeV demo facility

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Shu-Hui, E-mail: liush@impcas.ac.cn [Institute of Modern Physics, the Chinese Academy of Sciences, Lanzhou 730000 (China); Wang, Zhi-Jun; Jia, Huan [Institute of Modern Physics, the Chinese Academy of Sciences, Lanzhou 730000 (China); He, Yuan, E-mail: hey@impcas.ac.cn [Institute of Modern Physics, the Chinese Academy of Sciences, Lanzhou 730000 (China); Dou, Wei-Ping; Qin, Yuan-Shuai; Chen, Wei-Long [Institute of Modern Physics, the Chinese Academy of Sciences, Lanzhou 730000 (China); Yan, Fang [Institute of High Energy Physics, the Chinese Academy of Sciences, Beijing 100049 (China)

    2017-01-21

    A superconducting linac has been proposed and under constructed to demonstrate the key technology and the feasibility for CIADS(China Initiative Accelerator Driven System)linac. This linac will accelerate the 10 mA proton beam to 25 MeV. There are some challenges in the physics design for the high power superconducting accelerator. In this paper, we focus on the matching between different cryomodules (CMs) and the frequency jump. This paper presents the physics design study together with the design principles and the simulation results with machine errors.

  19. CESAR, 2 MeV electron storage ring; construction period; general view.

    CERN Multimedia

    Service Photo; CERN PhotoLab

    1962-01-01

    A general view of the 2-MeV electron storage-ring model during the last stages of assembly. The injection line for the electrons enters at the bottom of the picture (under the ladder) and meets the ring at the back, to the right. Near there, Joseph Karouanton (S.G.T.E, Paris) (inside the ring), and Marcel Bernasconi (AR Division) are seen testing for leaks in the vacuum system. In white coats are Mervin Barnes (left) and Boony Bruggerman (AR Division), considering the reading shown by one of the vacuum gauges.

  20. Parity Nonconservation in Proton-water Scattering at 800 MeV

    Science.gov (United States)

    Nagle, D. E.; Bowman, J. D.; Carlini, R.; Mischke, R. E.; Frauenfelder, H.; Harper, R. W.; Yuan, V.; McDonald, A. B.; Talaga, R.

    1982-01-01

    A search has been made for parity nonconservation in the scattering of 800 MeV polarized protons from an unpolarized water target. The result is for the longitudinal asymmetry, A{sub L} = +(6.6 +- 3.2) x 10{sup -7}. Control runs with Pb, using a thickness which gave equivalent beam broadening from Coulomb multiple scattering, but a factor of ten less nuclear interactions than the water target, gave A{sub L} = -(0.5 +- 6.0) x 10{sup -7}.

  1. Laser-Compton scattering from a 20 MeV electron beam

    CERN Document Server

    Chouffani, K; Harmon, F; Jones, J; Lancaster, G

    2002-01-01

    Laser-Compton scattering (LCS) experiments were carried out at the Idaho Accelerator Center. A 20 MeV electron beam was brought to a head-on collision with a 100 MW 7 ns Nd:YAG laser. We observed clear narrow LCS X-ray spectral peaks resulting from the interaction of the electron beam with the two Nd:YAG laser photon lines of 1064 and 532 nm. The LCS X-ray energy lines and widths were measured as a function of the electron beam energy and energy spread, respectively. The results recorded showed good agreement with the predicted values.

  2. Time resolution of resistive plate chambers investigated with 10 MeV electrons

    Energy Technology Data Exchange (ETDEWEB)

    Paradela, C., E-mail: carlos.paradela@usc.es [Universidad de Santiago de Compostela, E-15782, Santiago de Compostela (Spain); Ayyad, Y.; Benlliure, J. [Universidad de Santiago de Compostela, E-15782, Santiago de Compostela (Spain); Casarejos, E. [Universidad de Vigo, E-36310 Vigo (Spain); Duran, I. [Universidad de Santiago de Compostela, E-15782, Santiago de Compostela (Spain)

    2014-01-21

    The time resolution of double-gap timing resistive plate chambers (tRPC) has been measured with 10 MeV electron bunches of variable intensity. The use of electrons delivered in bunches of a few picoseconds was an attempt to mimic the energy deposition of heavy ions in the tRPC gas gap. The measurements show a clear dependence of the time resolution with the number of electrons per bunch, reaching 21 ps (standard deviation) for the highest beam intensity. The signal charge distribution and the time resolution are compared to data obtained with the same detectors for cosmic rays and {sup 238}U ions at 1 AGeV.

  3. Identification of defects in GaAs induced by 1 MeV electron irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Lai, S.T.; Nener, B.D.; Faraone, L.; Nassibian, A.G. [Western Australia Univ., Nedlands, WA (Australia); Hotchkis, M.A.C. [Australian Nuclear Science and Technology Organisation, Lucas Heights, NSW (Australia)

    1993-12-31

    This paper shows that 1 MeV electron irradiation on n-type vapor phase epitaxial (VPE) GaAs creates three electron traps E1, E2 and EL6, and results in the splitting of the EL2 center into two levels EL2-A and EL2-B. A 15 minutes isochronal anneal results in the annihilation of the E1 and E2 traps, a reduction in EL6 trap concentration, and the return of EL2 to a single level EL2-A. A defect model is outlined which correlates with the observed results. 4 refs., 2 tabs., 3 figs.

  4. Production of gamma rays with energies greater than 30 MeV in the atmosphere

    Science.gov (United States)

    Thompson, D.; Fichtel, C.; Kniffen, D.

    1974-01-01

    A three-dimensional study of atmospheric gamma rays with energy greater than 30 MeV has been carried out. Experimental results were obtained from four balloon flights from Palestine, Texas, with a 15 cm by 15 cm digitized wire grid spark chamber. The energy spectrum for downward-moving gamma rays steepens with increasing atmospheric depth. Near the top of the atmosphere, the spectrum steepens with increasing zenith angle. Experimental results compare reasonably well with a three-dimensional Monte Carlo calculation of atmospheric gamma ray production. Inclusion of upward-moving gamma rays makes possible the use of atmospheric secondaries for in-flight calibration of satellite gamma ray detectors.

  5. Experimental excitation functions of deuteron induced reactions on natural thallium up to 50 MeV

    Energy Technology Data Exchange (ETDEWEB)

    Adam Rebeles, R., E-mail: radamreb@vub.ac.be [Cyclotron Laboratory, Vrije Universiteit Brussel, B-1090 Brussels (Belgium); Van den Winkel, P.; Hermanne, A. [Cyclotron Laboratory, Vrije Universiteit Brussel, B-1090 Brussels (Belgium); Tarkanyi, F.; Takacs, S. [Institute of Nuclear Research of the Hungarian Academy of Sciences, Debrecen H-4026 (Hungary)

    2012-10-01

    Excitation functions of deuteron induced reactions on natural thallium leading to the formation of {sup 204m,203m2+m1+g,202m,201m+g,200}Pb and {sup 202,201m+g,200m+g}Tl isotopes were determined up to 50 MeV. The cross sections were measured by an activation technique using stacked foil irradiation. The excitation functions of the investigated reactions are compared with data reported in literature and also with the theoretical results of TALYS nuclear reaction code. From the measured cross section data, the thick target yield for the medical interesting {sup 203}Pb isotope is calculated.

  6. Radioprotection shielding for neutrons induced by the reaction (2H (40 MeV), 12C)

    Science.gov (United States)

    Fadil, M.

    2017-09-01

    In the framework of design studies for SPIRAL2, the simulation of the neutron flux generated by 40 MeV deuterons on a thick 12C target was performed and compared to experimental data. The calculation of the dose rate of these neutrons allowed to compare four materials being considered for radioprotection shielding: barites, gypsum, ordinary concrete and heavy concrete. The simulated map of the neutron dose rate in the production building shows a very high dose rate around the neutron source and in the environment of some of the accelerator equipment.

  7. Radioprotection shielding for neutrons induced by the reaction (2H (40 MeV, 12C

    Directory of Open Access Journals (Sweden)

    Fadil M.

    2017-01-01

    Full Text Available In the framework of design studies for SPIRAL2, the simulation of the neutron flux generated by 40 MeV deuterons on a thick 12C target was performed and compared to experimental data. The calculation of the dose rate of these neutrons allowed to compare four materials being considered for radioprotection shielding: barites, gypsum, ordinary concrete and heavy concrete. The simulated map of the neutron dose rate in the production building shows a very high dose rate around the neutron source and in the environment of some of the accelerator equipment.

  8. Minnesota Pheasant Range

    Data.gov (United States)

    Minnesota Department of Natural Resources — This dataset delineates the spatial range of wild pheasant populations in Minnesota as of 2002 by dividing the MN state boundary into 2 units: pheasant range and...

  9. Substring Range Reporting

    DEFF Research Database (Denmark)

    Bille, Philip; Gørtz, Inge Li

    2014-01-01

    We revisit various string indexing problems with range reporting features, namely, position-restricted substring searching, indexing substrings with gaps, and indexing substrings with intervals. We obtain the following main results. We give efficient reductions for each of the above problems...... to a new problem, which we call substring range reporting. Hence, we unify the previous work by showing that we may restrict our attention to a single problem rather than studying each of the above problems individually. We show how to solve substring range reporting with optimal query time and little...... for substring range reporting generalize to substring range counting and substring range emptiness variants. We also obtain non-trivial time-space trade-offs for these problems. Our bounds for substring range reporting are based on a novel combination of suffix trees and range reporting data structures...

  10. Investigation of the 66Zn(p,2pn) 64Cu and 68Zn(p,x) 64Cu nuclear processes up to 100 MeV: Production of 64Cu

    Science.gov (United States)

    Szelecsényi, F.; Steyn, G. F.; Kovács, Z.; Vermeulen, C.; van der Meulen, N. P.; Dolley, S. G.; van der Walt, T. N.; Suzuki, K.; Mukai, K.

    2005-11-01

    Cross-sections of the 66Zn(p,2pn)64Cu and 68Zn(p,x)64Cu nuclear processes were measured on highly enriched zinc targets using the stacked-foil activation technique up to 100 MeV. The new cross-sections were compared to literature data. The optimum energy range for production of 64Cu was found to be 70 → 35 MeV on 66Zn and 37 → 20 MeV on 68Zn. The thick-target yields were determined as 777 MBq/μAh (21.0 mCi/μAh) and 185 MBq/μAh (5.0 mCi/μAh), respectively. The yields of the longer-lived contaminant copper radioisotopes (i.e. 61Cu when using 66Zn as target material and both 61Cu and 67Cu in the case of 68Zn target material) were also calculated. The results obtained from the present study indicate that both reactions are suited for the production of 64Cu at a medium energy cyclotron. The optimum energy ranges are also complementary therefore the potential to utilize tandem targetry exists.

  11. sup 2 sup 3 sup 9 Pu and sup 2 sup 4 sup 1 Am (n, 2n) cross-section measurements near E sub n =14 MeV

    CERN Document Server

    Lougheed, R W; Namboodiri, M N; Nethaway, D R; Moody, K J; Landrum, J H; Hoff, R W; Dupzyk, R J; McQuaid, J H; Gunnink, R; Watkins, E D

    2002-01-01

    We measured the (n,2n) cross sections for neutron energies from 13.7 to 15.1 MeV on sup 2 sup 3 sup 9 Pu and sup 2 sup 4 sup 1 Am by alpha- and gamma-spectroscopy measurements of the post-irradiation sup 2 sup 3 sup 8 Pu/ sup 2 sup 3 sup 9 Pu and sup 2 sup 4 sup 0 Am/ sup 2 sup 4 sup 1 Am ratios relative to the (n,2n) cross sections of sup 1 sup 9 sup 6 Au and other calibration reactions. Statistical errors on the measurements were not more than a few percent. Cross-section values ranged from 228 to 214 millibarns for the reaction on 239Pu and from 260 to 222 millibarns for the sup 2 sup 4 sup 1 Am reaction for neutron energies from 13.7 to 15.1 MeV.

  12. TL response of Eu activated LiF nanocubes irradiated by 85 MeV carbon ions

    Energy Technology Data Exchange (ETDEWEB)

    Salah, Numan, E-mail: nsalah@kau.edu.sa [Center of Nanotechnology, King Abdulaziz University, Jeddah 21589 (Saudi Arabia); Alharbi, Najlaa D. [Sciences Faculty for Girls, King Abdulaziz University, Jeddah 21589 (Saudi Arabia); Habib, Sami S. [Center of Nanotechnology, King Abdulaziz University, Jeddah 21589 (Saudi Arabia); Lochab, S.P. [Inter-University Accelerator Centre, Aruna Asaf Ali Marg, New Delhi 110067 (India)

    2015-09-01

    Carbon ions were found to be effective for cancer treatment. These heavy ions have a high relative biological effectiveness compared to those of photons. They have higher linear energy transfer and sharper Bragg peak with a very excellent local tumor control. However, the dose of these swift heavy ions needs to be measured with great accuracy. Lithium fluoride (LiF) is a highly sensitive phosphor widely used for radiation dosimetry. In this work Eu activated LiF nanocubes were exposed to 85 MeV C{sup 6+} ion beam and evaluated for their thermoluminescence (TL) response. Pellet forms of this nanomaterial were exposed to these ions in the fluence range 10{sup 9}–10{sup 13} ions/cm{sup 2}. The obtained result shows a prominent TL glow peak at around 320 °C, which is different than that induced by gamma rays. This glow peak exhibits a linear response in the range 10{sup 9}–10{sup 12} ions/cm{sup 2}, corresponding to the equivalent absorbed doses 0.273–273 kGy. The absorbed doses, penetration depths and main energy loss were calculated using TRIM code based on the Monte Carlo simulation. The supralinearity function and stopping power in this nanomaterial were also studied. The modification induced in the glow curve structure as a result of changing irradiation type might be utilized to use LiF:Eu nanocubes as a dosimeter for mixed filed radiations. Moreover, the wide linear response of LiF:Eu nanocubes along with the low fading are another imperative results suggesting that this nanomaterial might be a good candidate for carbon ions dosimetry.

  13. DoPET: an in-treatment monitoring system for proton therapy at 62 MeV

    Science.gov (United States)

    Rosso, V.; Belcari, N.; Bisogni, M. G.; Camarlinghi, N.; Cirrone, G. A. P.; Collini, F.; Cuttone, G.; Del Guerra, A.; Milluzzo, G.; Morrocchi, M.; Raffaele, L.; Romano, F.; Sportelli, G.; Zaccaro, E.

    2016-12-01

    Proton beam radiotherapy is highly effective in treating cancer thanks to its conformal dose deposition. This superior capability in dose deposition has led to a massive growth of the treated patients around the world, raising the need of treatment monitoring systems. An in-treatment PET system, DoPET, was constructed and tested at CATANA beam-line, LNS-INFN in Catania, where 62 MeV protons are used to treat ocular melanoma. The PET technique profits from the beta+ emitters generated by the proton beam in the irradiated body, mainly 15-O and 11-C. The current DoPET prototype consists of two planar 15 cm × 15 cm LYSO-based detector heads. With respect to the previous versions, the system was enlarged and the DAQ up-graded during the years so now also anthropomorphic phantoms, can be fitted within the field of view of the system. To demonstrate the capability of DoPET to detect changes in the delivered treatment plan with respect to the planned one, various treatment plans were used delivering a standard 15 Gy fraction to an anthropomorphic phantom. Data were acquired during and after the treatment delivery up to 10 minutes. When the in-treatment phase was long enough (more than 1 minute), the corresponding activated volume was visible just after the treatment delivery, even if in presence of a noisy background. The after-treatment data, acquired for about 9 minutes, were segmented finding that few minutes are enough to be able to detect changes. These experiments will be presented together with the studies performed with PMMA phantoms where the DoPET response was characterized in terms of different dose rates and in presence of range shifters: the system response is linear up to 16.9 Gy/min and has the ability to see a 1 millimeter range shifter.

  14. [BIOLOGICAL EFFECTIVENESS OF FISSION SPECTRUM NEUTRONS AND PROTONS WITH ENERGIES OF 60-126 MEV DURING ACUTE AND PROLONGED IRRADIATION].

    Science.gov (United States)

    Shafirkin, A V

    2015-01-01

    Neutrons of the fission spectrum are characterized by relatively high values of linear energy transfer (LET). Data about their effects on biological objects are used to evaluate the risk of delayed effects of accelerated ions within the same LET range that serve as an experimental model of the nuclei component of galactic cosmic rays (GCR). Additionally, risks of delayed consequences to cosmonaut's health and average lifetime from certain GCR fluxes and secondary neutrons can be also prognosticated. The article deals with comparative analysis of the literature on reduction of average lifespan (ALS) of animals exposed to neutron reactor spectrum, 60-126 MeV protons, and X- and γ-rays in a broad range of radiation intensity and duration. It was shown that a minimal lifespan reduction by 5% occurs due to a brief exposure to neutrons with the absorbed dose of 5 cGy, whereas same lifespan reduction due to hard X- and γ-radiation occurs after absorption of a minimal dose of 100 cGy. Therefore, according to the estimated minimal ALS reduction in mice, neutron effectiveness is 20-fold higher. Biological effectiveness of protons as regards ALS reduction is virtually equal to that of standard types of radiation. Exposure to X- and γ-radiation with decreasing daily doses, and increasing number of fractions and duration gives rise to an apparent trend toward a less dramatic ALS reduction in mice; on the contrary, exposure to neutrons of varying duration had no effect on threshold doses for the specified ALS reductions. Factors of relative biological effectiveness of neutrons reached 40.

  15. Surface Morphologies of Ti and Ti-Al-V Bombarded by 1.0-MeV Au+ Ions

    Science.gov (United States)

    Garcia, M. A.; Rickards, J.; Cuerno, R.; Trejo-Luna, R.; Cañetas-Ortega, J.; de la Vega, L. R.; Rodríguez-Fernández, L.

    2017-12-01

    Ion implantation is known to enhance the mechanical properties of biomaterials such as, e.g., the wear resistance of orthopedic joints. Increasing the surface area of implants may likewise improve their integration with, e.g., bone tissue, which requires surface features with sizes in the micron range. Ion implantation of biocompatible metals has recently been demonstrated to induce surface ripples with wavelengths of a few microns. However, the physical mechanisms controlling the formation and characteristics of these patterns are yet to be understood. We bombard Ti and Ti-6Al-4V surfaces with 1.0-MeV Au+ ions. Analysis by scanning electron and atomic force microscopies shows the formation of surface ripples with typical dimensions in the micron range, with potential indeed for biomedical applications. Under the present specific experimental conditions, the ripple properties are seen to strongly depend on the fluence of the implanted ions while being weakly dependent on the target material. Moreover, by examining experiments performed for incidence angle values θ =8 ° , 23°, 49°, and 67°, we confirm the existence of a threshold incidence angle for (ripple) pattern formation. Surface indentation is also used to study surface features under additional values of θ , agreeing with our single-angle experiments. All properties of the surface structuring process are very similar to those found in the production of surface nanopatterns under low-energy ion bombardment of semiconductor targets, in which the stopping power is dominated by nuclear contributions, as in our experiments. We consider a continuum model that combines the effects of various physical processes as originally developed in that context, with parameters that we estimate under a binary-collision approximation. Notably, reasonable agreement with our experimental observations is achieved, even under our high-energy conditions. Accordingly, in our system, ripple formation is determined by mass

  16. Neutron background spectra and signal-to-background ratio for neutron production between 10 and 14 MeV by the reactions /sup 3/H(p,n)/sup 3/He, /sup 1/H(t,n)/sup 3/He, and /sup 2/H(d,n)/sup 3/He

    Energy Technology Data Exchange (ETDEWEB)

    Drosg, M.; Auchampaugh, G.F.; Gurule, F.

    1976-07-01

    The monochromaticity of a ''single line'' neutron source is of utmost importance whenever secondary neutron yields over a wide energy range must be measured. Among the neutron sources considered, /sup 3/H(p,n)/sup 3/He is best if a suitable beam stop is used; for example, /sup 28/Si or /sup 58/Ni. Tantalum and gold give much larger backgrounds. Neutron emission spectra from the hydrogen gases and from various beam stops have been measured and are given in 1-MeV steps for primary neutron energies between 10 and 14 MeV.

  17. Baseline Design of a Solid Neutron Converter Driven by 160 MeV Protons

    CERN Document Server

    Herrera-Martínez, A

    2006-01-01

    The European Isotope Separation On-Line Radioactive Ion Beam Facility Design Study (EURISOL DS) aims at the design of several spallation and fission targets for the production of radioactive isotopes. Namely, direct targets, where high-energy protons interact directly with the fission targets, as well as the design of a Multi-MW proton-to-neutron converter coupled with a fission target. For the later, several options have been proposed, including the use of a relatively low energy (in the hundreds of MeV) high intensity proton beam. In this scope, the neutronic characteristics of a tantalum n-converter/fission-target system have been established (although not yet optimised) for a reference proton energy of 160 MeV. A set of simulations has been carried out for different design requirements and different characteristics of the proton beam. An extensive comparison of the main physical parameters has also been carried out, in order to allow the optimal engineering design of the whole target station.

  18. INEL and ISU BNCT research using a 2 MeV RFQ-based neutron source

    Energy Technology Data Exchange (ETDEWEB)

    Harker, Y.D. [Idaho National Engineering Lab., Idaho Falls, ID (United States)

    1994-12-31

    A radio frequency quadrapole (RFQ) proton linear accelerator manufactured by AccSys Corp. was purchased by the U.S. Department of Energy and was installed in the Particle Beam Laboratory at Idaho State University (ISU). It is available for physics studies consistent with the INEL mission such as those related to accelerator produced neutron sources for boron neutron capture therapy (BNCT). It is an AccSys model PL-1 and is designed to produce 2 MeV protons at an average current of 150{mu}A. The overall objective of the INEL BNCT/ISU collaborative program is to evaluate neutron filter design concepts which use a 2 MeV proton accelerator with a lithium target as the neutron source. This paper will discuss the overall plan of INEL/ISU collaborative program and how it relates to other university and government laboratory studies, the methods being employed in this study and results of neutron spectra and angular distribution measurements for different lithium target configurations.

  19. Anti-biofilm efficacy of 100 MeV gold ion irradiated polycarbonate against Salmonella typhi

    Science.gov (United States)

    Joshi, R. P.; Hareesh, K.; Bankar, A.; Sanjeev, G.; Asokan, K.; Kanjilal, D.; Dahiwale, S. S.; Bhoraskar, V. N.; Dhole, S. D.

    2017-12-01

    Polycarbonate (PC) films were irradiated by 100 MeV gold (Au7+) ions and characterized to study changes in its optical, chemical, surface morphology and thermal properties. UV-Visible spectroscopic results revealed the decrease in the optical band gap of PC after ion irradiation due to chain scission mainly at the carbonyl group which is corroborated by Fourier Transform Infrared spectroscopic results. X-ray diffractogram study showed decrease in crystallinity of PC film after irradiation. Scanning electron microscopic results showed the micropores formation in PC which results in surface roughening. Differential scanning calorimetric results revealed decrease in glass transition temperature indicating the decrease in molecular weight of PC corroborated by rheometric studies. PC films irradiated by 100 MeV Au7+ ions showed increased anti-biofilm activity against the human pathogen, Salmonella typhi (S. typhi). Morphology of S. typhi was changed due to stress of Au7+ irradiated PC. Cells length was increased with increasing fluences. The average cell length, cell volume and surface area was increased significantly (P<0.05) with increasing ion fluences. Biofilm formation was inhibited ≈ 20% at lower fluence and 96% at higher fluence, which observed to be enhanced anti-biofilm activity in Au7+ irradiated PC.

  20. Comparing Solar-Flare Acceleration of >-20 MeV Protons and Electrons Above Various Energies

    Science.gov (United States)

    Shih, Albert Y.

    2010-01-01

    A large fraction (up to tens of percent) of the energy released in solar flares goes into accelerated ions and electrons, and studies indicate that these two populations have comparable energy content. RHESSI observations have shown a striking close linear correlation between the 2.223 MeV neutron-capture gamma-ray line and electron bremsstrahlung emission >300 keV, indicating that the flare acceleration of >^20 MeV protons and >300 keV electrons is roughly proportional over >3 orders of magnitude in fluence. We show that the correlations of neutron-capture line fluence with GOES class or with bremsstrahlung emission at lower energies show deviations from proportionality, primarily for flares with lower fluences. From analyzing thirteen flares, we demonstrate that there appear to be two classes of flares with high-energy acceleration: flares that exhibit only proportional acceleration of ions and electrons down to 50 keV and flares that have an additional soft, low-energy bremsstrahlung component, suggesting two separate populations of accelerated electrons. We use RHESSI spectroscopy and imaging to investigate a number of these flares in detail.

  1. Diagnostics for a 1.2 kA, 1 MeV, electron induction injector

    Science.gov (United States)

    Houck, T. L.; Anderson, D. E.; Eylon, S.; Henestroza, E.; Lidia, S. M.; Vanecek, D. L.; Westenskow, G. A.; Yu, S. S.

    1998-12-01

    We are constructing a 1.2 kA, 1 MeV, electron induction injector as part of the RTA program, a collaborative effort between LLNL and LBNL to develop relativistic klystrons for Two-Beam Accelerator applications. The RTA injector will also be used in the development of a high-gradient, low-emittance, electron source and beam diagnostics for the second axis of the Dual Axis Radiographic Hydrodynamic Test (DARHT) Facility. The electron source will be a 3.5″-diameter, thermionic, flat-surface, m-type cathode with a maximum shroud field stress of approximately 165 kV/cm. Additional design parameters for the injector include a pulse length of over 150 ns flat top (1% energy variation), and a normalized edge emittance of less than 200 π-mm-mr. Precise measurement of the beam parameters is required so that performance of the RTA injector can be confidently scaled to the 4 kA, 3 MeV, and 2-microsecond pulse parameters of the DARHT injector. Planned diagnostics include an isolated cathode with resistive divider for direct measurement of current emission, resistive wall and magnetic probe current monitors for measuring beam current and centroid position, capacitive probes for measuring A-K gap voltage, an energy spectrometer, and a pepperpot emittance diagnostic. Details of the injector, beam line, and diagnostics are presented.

  2. A gas ionisation Direct-STIM detector for MeV ion microscopy

    Energy Technology Data Exchange (ETDEWEB)

    Norarat, Rattanaporn, E-mail: rattanaporn@rmutl.ac.th [University of Applied Sciences (HES-SO), Haute Ecole Arc Ingénierie, Eplatures-Gris 17, CH-2300 La Chaux-de-Fonds (Switzerland); Faculty of Science and Agriculture, Rajamangala University of Technology Lanna, Chiang Rai, 57120 Chiang Rai (Thailand); Department of Physics, University of Jyväskylä, P.O. Box 35, Jyväskylä FI-40014 (Finland); Guibert, Edouard; Jeanneret, Patrick; Dellea, Mario; Jenni, Josef [University of Applied Sciences (HES-SO), Haute Ecole Arc Ingénierie, Eplatures-Gris 17, CH-2300 La Chaux-de-Fonds (Switzerland); Roux, Adrien; Stoppini, Luc [Tissue Engineering Laboratory, Campus Biotech, Chemin des Mines 9, Geneva (Switzerland); Whitlow, Harry J. [University of Applied Sciences (HES-SO), Haute Ecole Arc Ingénierie, Eplatures-Gris 17, CH-2300 La Chaux-de-Fonds (Switzerland)

    2015-04-01

    Direct-Scanning Transmission Ion Microscopy (Direct-STIM) is a powerful technique that yields structural information in sub-cellular whole cell imaging. Usually, a Si p-i-n diode is used in Direct-STIM measurements as a detector. In order to overcome the detrimental effects of radiation damage which appears as a broadening in the energy resolution, we have developed a gas ionisation detector for use with a focused ion beam. The design is based on the ETH Frisch grid-less off-axis Geiger–Müller geometry. It is developed for use in a MeV ion microscope with a standard Oxford Microbeams triplet lens and scanning system. The design has a large available solid angle for other detectors (e.g. proton induced fluorescence). Here we report the performance for imaging ReNcells VM with μm resolution where energy resolutions of <24 keV fwhm could be achieved for 1 MeV protons using isobutane gas.

  3. Deuterium microscopy using 17 MeV deuteron–deuteron scattering

    Energy Technology Data Exchange (ETDEWEB)

    Reichart, Patrick, E-mail: patrick.reichart@unibw.de; Moser, Marcus; Greubel, Christoph; Peeper, Katrin; Dollinger, Günther, E-mail: guenther.dollinger@unibw.de

    2016-03-15

    Using 17 MeV deuterons as a micrometer focused primary beam, we performed deuterium microscopy by using the deuteron–deuteron (dd) scattering reaction. We describe our new box like detector setup consisting of four double sided silicon strip detectors (DSSSD) with 16 strips on each side, each covering up to 0.5 sr solid angle for coincidence detection. This method becomes a valuable tool for studies of hydrogen incorporation or dynamic processes using deuterium tagging. The background from natural hydrocarbon or water contamination is reduced by the factor 150 ppm of natural abundance of deuterium in hydrogen. Deuterium energies of up to 25 MeV, available at the microprobe SNAKE, are ideal for the analysis of thin freestanding samples so that the scattered particles are transmitted to the detector. The differential cross section for the elastic scattering reaction is about the same as for pp-scattering (~100 mb/sr). The main background due to nuclear reactions is outside the energy window of interest. Deuteron–proton (dp) scattering events give an additional signal for hydrogen atoms, so the H/D-ratio can be monitored in parallel. A deuterium detection limit due to accidental coincidences of 3 at-ppm down to less than 1 at-ppm is demonstrated on deuterated polypropylen sheets as well as thick polycarbonate sheets after various stages of coincidence filtering that is possible with our granular detector.

  4. Commissioning of the Linac4 RFQ at the 3 MeV test stand

    CERN Document Server

    Rossi, C; Bellodi, G; Broere, J; Brunner, O; Lombardi, A M; Balula, J M; Yanez, P M; Noirjean, J; Pasquino, C; Raich, U; Roncarolo, F; Vretenar, M; Desmons, M; France, A; Piquet, O

    2013-01-01

    Linac4, the future 160 MeV Hˉ injector to the CERN Proton Synchrotron Booster, is presently under construction at CERN as a first step of the planned upgrade of the LHC injectors. The low energy section of LINAC4, consisting of an ion source, a 352.2 MHz Radio Frequency Quadrupole (RFQ) and a chopper line is being commissioned in a dedicated test stand before installation in its final position in the tunnel. The RFQ is designed to accelerate a 45 keV, 70 mA, Hˉ beam to 3 MeV, with an efficiency of 95% while preserving the transverse emittance. The RFQ, a four-vane structure 3 m in length, has been designed in collaboration with CEA/IRFU and is has been fabricated at the CERN workshop. The precise fabrication has allowed achieving a field flatness of 1%. The completion of the accelerating structure in September 2012 was followed by a complete series of bead-pull measurements and by high-power conditioning to the nominal power of 0.39 MW corresponding to a voltage of 78 kV across the 3 meters. Measurements wi...

  5. Explosive detection system using pulsed 14 MeV neutron source

    Energy Technology Data Exchange (ETDEWEB)

    Sharma, Surender Kumar, E-mail: surender@ipr.res.in [E and ED, Bhabha Atomic Research Centre, Gandhinagar (India); Jakhar, Shrichand [Institute for Plasma Research, Gandhinagar (India); Shukla, Rohit; Shyam, Anurag [E and ED, Bhabha Atomic Research Centre, Gandhinagar (India); Rao, C.V.S. [Institute for Plasma Research, Gandhinagar (India)

    2010-12-15

    The main elements present in the explosives are hydrogen (H), nitrogen (N), oxygen (O) and carbon (C). The elemental density ratios (C/O, N/O, H/N, etc.) of explosives are different from the other substances. The explosives are characterized by low H and C concentration and high N and O concentration. The elemental composition of explosive materials can be found by measuring the {gamma}-rays produced due to the activation of explosive material by 14 MeV neutrons. A pulsed fast neutron system is used for the identification of H, N and O. Ammonium nitrate sample has been irradiated by pulsed 14 MeV neutrons of 10{sup 8} neutrons/pulse and the pulse width less than a microsecond. The material has been irradiated with 5-7 neutron pulse in order to increase the {gamma}-ray count. The resulting {gamma}-ray spectrum due to the activation of ammonium nitrate is recorded and presented in this work. The {gamma}-ray spectrum has been recorded using 3'' x 3'' Bismuth Germanium Orthosilicate (BGO) and fast digitizer with sampling rate of 2 GS/s. The signal is transferred through fiber optic cable to the personal computer for further processing and analyzing. Pulse-height spectrum is constructed through a dedicate MATLAB routine in which the number of energy bins can be kept as per requirement.

  6. Response of Inorganic Scintillators to Neutrons of 3 and 15 MeV Energy

    CERN Document Server

    Lucchini, M; Pizzichemi, M; Chipaux, R; Jacquot, F; Mazue, H; Wolff, H; Lecoq, P; Auffray, E

    2014-01-01

    In the perspective of the development of future high energy physics experiments, homogeneous calorimeters based on inorganic scintillators can be considered for the detection of hadrons (e.g., calorimeter based on dual-readout technique). Although of high importance in the high energy physics framework as well as for homeland security applications, the response of these inorganic scintillators to neutrons has been only scarcely investigated. This paper presents results obtained using five common scintillating crystals (of size around 2x2x2 cm 3), namely lead tungstate (PbWO4), bismuth germanate (BGO), cerium fluoride (CeF3), Ce-doped lutetium-yttrium orthosilicate (LYSO:Ce) and lutetium aluminum garnet (LuAG:Ce) in a pulsed flux of almost mono-energetic (similar to 3 MeV and similar to 15 MeV) neutrons provided by the Van de Graff accelerator SAMES of CEA Valduc. Energy spectra have been recorded, calibrated and compared with Geant4 simulations computed with different physics models. The neutron detection eff...

  7. Technology for Fissionable Materials Detection by Use of 100 MeV Variable Linac

    CERN Document Server

    Karasyov, Sergey P; Dovbnja, Anatoliy N; Eran, L; Kiryukhin, Nikolay M; Melnik, Yu M; Ran'iuk, Yu; Shlyakhov, Il'ya N; Trubnikov, Sergiy V

    2005-01-01

    A new concept for a two-step facility to increase the accuracy/reliability of detecting heavily shielded fissionable materials (FM) in marine containers is presented. The facility will detect FM in two steps. An existing dual-view; dual-energy X-ray scanner, which is based on 7 MeV electron accelerator, will select the suspicious places inside container. The linac with variable energy (up to 100 MeV) will be used for the second step. The technology will detect fissionable nuclei by gamma induced fission reactions and delayed neutron registration. A little-known Ukrainian experimental data obtained in Chernobil' clean-up program will be presented to ground proposed concept. The theoretical calculations of neutron fluxes scale these results to marine container size. Modified GEANT code for electron/gamma penetration and authors' own software for neutron yield/penetration are used for these calculations. Available facilities (X-ray scanners; linac; detectors), which will be used for concept proof, are described....

  8. Neutron induced inelastic cross sections of 150Sm for En = 1 to 35 MeV

    Energy Technology Data Exchange (ETDEWEB)

    Dashdorj, D; Mitchell, G E; Kawano, T; Becker, J A; Agvaanluvsan, U; Chadwick, M B; Cooper, J R; Devlin, M; Fotiades, N; Garrett, P E; Nelson, R O; Wu, C Y; Younes, W

    2006-08-16

    Cross-section measurements were made of prompt gamma-ray production as a function of incident neutron energy (E{sub n} = 1 to 35 MeV) on an enriched (95.6%) {sup 150}Sm sample. Energetic neutrons were delivered by the Los Alamos National Laboratory spallation neutron source located at the Los Alamos Neutron Science Center (LANSCE) facility. The prompt-reaction gamma rays were detected with the large-scale Compton-suppressed Germanium Array for Neutron Induced Excitations (GEANIE). Neutron energies were determined by the time-of-flight technique. The {gamma}-ray excitation functions were converted to partial {gamma}-ray cross sections taking into account the dead-time correction, target thickness, detector efficiency and neutron flux (monitored with an in-line fission chamber). Partial {gamma}-ray cross sections were predicted using the Hauser-Feshbach statistical reaction code GNASH. Above E{sub n} {approx} 8 MeV the pre-equilibrium reaction process dominates the inelastic reaction. The spin distribution transferred in pre-equilibrium neutron-induced reactions was calculated using the quantum mechanical theory of Feshbach, Kerman, and Koonin (FKK). These pre-equilibrium spin distributions were incorporated into a new version of GNASH and the {gamma}-ray production cross sections were calculated and compared with experimental data. The difference in the partial {gamma}-ray cross sections using spin distributions with and without pre-equilibrium effects is discussed.

  9. Neutron induced inelastic cross-sections of 150Sm for En = 1 35 MeV

    Science.gov (United States)

    Dashdorj, D.; Mitchell, G. E.; Kawano, T.; Becker, J. A.; Agvaanluvsan, U.; Chadwick, M. B.; Cooper, J. R.; Devlin, M.; Fotiades, N.; Garrett, P. E.; Nelson, R. O.; Wu, C. Y.; Younes, W.

    2007-08-01

    Cross-section measurements were made of prompt γ-ray production as a function of incident neutron energy (En = 1-35 MeV) on an enriched (95.6%) l50Sm sample. Energetic neutrons were delivered by the Los Alamos National Laboratory spallation neutron source located at the Los Alamos Neutron Science Center (LANSCE) facility. The prompt-reaction γ-rays were detected with the large-scale Compton-suppressed germanium array for neutron induced excitations (GEANIE). Neutron energies were determined by the time-of-flight technique. The γ-ray excitation functions were converted to partial γ-ray cross-sections taking into account the dead-time correction, target thickness, detector efficiency and neutron flux (monitored with an in-line fission chamber). Partial γ-ray cross-sections were predicted using the Hauser-Feshbach statistical reaction code GNASH. Above En ∼ 8 MeV, the pre-equilibrium reaction process dominates the inelastic reaction. The spin-distribution transferred in pre-equilibrium neutron induced reactions was calculated using the quantum mechanical theory of Feshbach, Kerman and Koonin (FKK). These pre-equilibrium spin distributions were incorporated into a new version of GNASH and the γ-ray production cross-sections were calculated and compared with experimental data. The difference in the partial γ-ray cross-sections using spin-distributions with and without pre-equilibrium effects is discussed.

  10. MeV ion beam lithography of biocompatible halogenated Parylenes using aperture masks

    Science.gov (United States)

    Whitlow, Harry J.; Norarat, Rattanaporn; Roccio, Marta; Jeanneret, Patrick; Guibert, Edouard; Bergamin, Maxime; Fiorucci, Gianni; Homsy, Alexandra; Laux, Edith; Keppner, Herbert; Senn, Pascal

    2015-07-01

    Parylenes are poly(p-xylylene) polymers that are widely used as moisture barriers and in biomedicine because of their good biocompatibility. We have investigated MeV ion beam lithography using 16O+ ions for writing defined patterns in Parylene-C, which is evaluated as a coating material for the Cochlear Implant (CI) electrode array, a neuroprosthesis to treat some forms of deafness. Parylene-C and -F on silicon and glass substrates as well as 50 μm thick PTFE were irradiated to different fluences (1 ×1013 - 1 ×1016 1 MeV 16O+ ions cm-2) through aperture masks under high vacuum and a low pressure (<10-3 mbar) oxygen atmosphere. Biocompatibility of the irradiated and unirradiated surfaces was tested by cell-counting to determine the proliferation of murine spiral ganglion cells. The results reveal that an oxygen ion beam can be used to pattern Parylene-C and -F without using a liquid solvent developer in a similar manner to PTFE but with a ∼25× smaller removal rate. Biocompatibility tests showed no difference in cell adhesion between irradiated and unirradiated areas or ion fluence dependence. Coating the Parylene surface with an adhesion-promoting protein mixture had a much greater effect on cell proliferation.

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

    CERN Document Server

    AUTHOR|(CDS)2084247; Santoni, Claudio

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

  12. A review of electron-nucleus bremsstrahlung cross sections between 1 and 10 MeV

    Science.gov (United States)

    Mangiarotti, A.; Martins, M. N.

    2017-12-01

    More than 80 years have passed since the first calculations of electron-nucleus bremsstrahlung cross sections were published by Sommerfeld, for non-relativistic electrons, and, independently, by Sauter, Bethe and Heitler, and Racah, for relativistic electrons. The Bethe-Heitler expression, that is based on the first Born approximation and includes the screening of the Coulomb field of the nucleus by the atomic electrons, has proven to work well at moderately high energies where the Landau-Pomeranchuk-Migdal effect is negligible. We review the current theoretical and experimental status with a highlight on electrons with kinetic energies between 1 and 10 MeV. The choice is motivated by the peculiar difficulties present in this energy region, where it is necessary to treat simultaneously the interaction with the Coulomb field beyond the first Born approximation and the effect of screening. A fully numerical approach within the S-matrix formalism has proven to be extremely difficult above a few MeV, because the number of partial waves needed for an accurate evaluation is prohibitively large. Here we focus on analytic results, including the more complex ones employing the Furry-Sommerfeld-Maue wave functions and taking into account the next-to-leading order, and discuss the advantages and limitations in light of the best available data. The influence of multiple scattering in the target is investigated under the actual experimental conditions. A comparison with the widely used cross section tabulations by Seltzer and Berger is also presented.

  13. Substring Range Reporting

    DEFF Research Database (Denmark)

    Bille, Philip; Gørtz, Inge Li

    2011-01-01

    We revisit various string indexing problems with range reporting features, namely, position-restricted substring searching, indexing substrings with gaps, and indexing substrings with intervals. We obtain the following main results. – We give efficient reductions for each of the above problems...... to a new problem, which we call substring range reporting. Hence, we unify the previous work by showing that we may restrict our attention to a single problem rather than studying each of the above problems individually. – We show how to solve substring range reporting with optimal query time and little...... range reporting are based on a novel combination of suffix trees and range reporting data structures. The reductions are simple and general and may apply to other combinations of string indexing with range reporting....

  14. Compact Antenna Range

    Data.gov (United States)

    Federal Laboratory Consortium — Facility consists of a folded compact antenna range including a computer controlled three axis position table, parabolic reflector and RF sources for the measurement...

  15. Dryden Aeronautical Test Range

    Data.gov (United States)

    Federal Laboratory Consortium — Recently redesignated to honor Dr. Hugh L. Dryden, NASA's Dryden Aeronautical Test Range (DATR) supports aerospace flight research and technology integration, space...

  16. Reduction of anti-ferroelectric temperature region in NBT-BT ceramics using 100 MeV O{sup 7+} ion irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Shanmuga Sundari, S. [Crystal Growth Centre, Anna University, Chennai 600025 (India); Murugan, Ramaswamy [Department of Physics, Pondicherry University, Pondicherry 605014 (India); Asokan, K. [Inter University Accelerator Centre, Aruna Asaf Ali Marg, New Delhi 110067 (India); Dhanasekaran, R., E-mail: rdcgc@yahoo.com [Crystal Growth Centre, Anna University, Chennai 600025 (India)

    2014-01-01

    NBT-BT (sodium bismuth titanate-barium titanate) lead-free ceramics were prepared via the conventional solid-state reaction method in the Morphotropic Phase Boundary (MPB) composition. The prepared ceramics were irradiated with 100 MeV O{sup 7+} ions using four different fluences of 5 × 10{sup 11}, 1 × 10{sup 12}, 5 × 10{sup 12} and 1 × 10{sup 13} ions/cm{sup 2}. The dielectric constants of the pristine and irradiated samples were determined from 300 to 623 K for a broad range of frequencies from 20 Hz to 2 MHz. Irradiation with oxygen ions decreased the anti-ferroelectric temperature region present in the samples. The structural stability of the samples against the irradiation was investigated via XRD and Raman spectroscopy before and after the irradiation.

  17. Excitation functions of (p,x) reactions on natural nickel between proton energies of 2.7 and 27.5 MeV

    Energy Technology Data Exchange (ETDEWEB)

    Al Saleh, F.S. [Physics Department Girls College of Education in Riyadh (Saudi Arabia); Al Mugren, K.S. [Physics Department Girls College of Education in Riyadh (Saudi Arabia)]. E-mail: kmugren@hotmail.com; Azzam, A. [Nuclear Physics Department, Nuclear Research Center, AEA Cairo Egypt (Egypt)

    2007-01-15

    Excitation functions have been measured for a number of proton induced nuclear reactions on natural nickel in the energy range from 27.5 MeV down to their threshold energy, using the activation method on stacked foils. Excitation functions for the reactions leading to the formation of {sup 60}Cu, {sup 61}Cu, {sup 56}Ni, {sup 57}Ni, {sup 55}Co, {sup 56}Co, {sup 57}Co and {sup 58}Co are presented and compared with earlier reported experimental data. Comparison with the recommended data reported by the International Atomic Energy Agency [Gul et al., 2001. Charged particle cross section database for medical radioisotope production. IAEA-TECDOC-1211, IAEA Vienna, Austria] is also presented when possible.

  18. Measurement of cross sections producing short-lived nuclei by 14MeV neutron. Cd, Sn, Te, Nd, Gd, Re

    Energy Technology Data Exchange (ETDEWEB)

    Sakane, H.; Yamamoto, H.; Kawade, K. [Nagoya Univ. (Japan); Iida, T.; Takahashi, A.

    1998-03-01

    Nine neutron activation cross sections producing the nuclei with half-lives between 25sec and 22min were measured at energy range between 13.4 and 14.9 MeV by activation method. The (n,p) and (n,{alpha}) reaction cross sections were measured for the isotopes of {sup 110}Cd, {sup 112}Sn, {sup 122}Te, {sup 130}Te and {sup 185}Re and those of {sup 130}Te, {sup 148}Nd and {sup 158}Gd, respectively. The present results were compared with our systematics proposed on the basis of 58 cross section data of (n,p) and 33 data of (n,{alpha}) reaction. Good agreements have been seen between them. (author)

  19. Geant4 Monte Carlo simulation of absorbed dose and radiolysis yields enhancement from a gold nanoparticle under MeV proton irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Tran, H.N., E-mail: tranngochoang@tdt.edu.vn [Division of Nuclear Physics, Ton Duc Thang University, Tan Phong Ward, District 7, Ho Chi Minh City (Viet Nam); Faculty of Applied Sciences, Ton Duc Thang University, Tan Phong Ward, District 7, Ho Chi Minh City (Viet Nam); Karamitros, M. [Notre Dame Radiation Laboratory, University of Notre-Dame, IN 46556 (United States); Ivanchenko, V.N. [Geant4 Associates International Ltd, Hebden Bridge (United Kingdom); Guatelli, S.; McKinnon, S. [Centre For Medical Radiation Physics, University of Wollongong (Australia); Illawarra Health and Medical Research, University of Wollongong, NSW (Australia); Murakami, K.; Sasaki, T.; Okada, S. [Computing Research Center, High Energy Accelerator Organization, KEK, Tsukuba City (Japan); Bordage, M.C. [INSERM, UMR 1037, CRCT, F-31000 Toulouse (France); Univ. Toulouse III-Paul Sabatier, UMR 1037, CRCT, F-31000 Toulouse (France); Francis, Z. [Saint Joseph University, Faculty of Sciences, Department of Physics, Beirut (Lebanon); El Bitar, Z. [Institut Pluridisciplinaire Hubert Curien/IN2P3/CNRS, Strasbourg (France); Bernal, M.A. [Instituto de Física Gleb Wataghin, Universidade Estadual de Campinas, SP (Brazil); Shin, J.I. [Division of Heavy Ion Clinical Research, Korea Institute of Radiological and Medical Science, 75, Nowon-ro, Nowon-gu, Seoul (Korea, Republic of); Lee, S.B. [Proton Therapy Center, National Cancer Center, 323, Ilsan-ro, Ilsandong-gu, Goyang-si, Gyeonggi-do (Korea, Republic of); Barberet, Ph. [Univ. Bordeaux, CENBG, UMR 5797, F-33170 Gradignan (France); CNRS, IN2P3, CENBG, UMR 5797, F-33170 Gradignan (France); Tran, T.T. [VNUHCM-University of Science (Viet Nam); Brown, J.M.C. [School of Mathematics and Physics, Queen’s University Belfast, Belfast, Northern Ireland (United Kingdom); and others

    2016-04-15

    Gold nanoparticles have been reported as a possible radio-sensitizer agent in radiation therapy due to their ability to increase energy deposition and subsequent direct damage to cells and DNA within their local vicinity. Moreover, this increase in energy deposition also results in an increase of the radiochemical yields. In this work we present, for the first time, an in silico investigation, based on the general purpose Monte Carlo simulation toolkit Geant4, into energy deposition and radical species production around a spherical gold nanoparticle 50 nm in diameter via proton irradiation. Simulations were preformed for incident proton energies ranging from 2 to 170 MeV, which are of interest for clinical proton therapy.

  20. Production cross sections of products in the proton induced reactions on natNd in the energy region up to 45 MeV

    Science.gov (United States)

    Yang, Sung-Chul; Kim, Kwangsoo; Song, Tae-Yung; Lee, Young-Ouk; Kim, Guinyun

    2015-11-01

    The production cross sections of 141,143,144,146,148m,148g,149,150Pm, 139m,147,149Nd, 138m,142gPr, and 139gCe in the natNd(p,x) reactions were determined by a stacked-foil activation technique for the proton energy range up to 45 MeV using the MC-50 cyclotron of Korea Institute of Radiological and Medical Sciences. The measured cross sections were compared with literature data as well as data from the TENDL-2014 library based on TALYS 1.6. The production cross sections of the above radionuclides are slightly higher than the literature data but are in general agreement with values in TENDL-2014 library except for 148mPm, 148gPm, 139mNd, and 142gPr. The thick target integral yields of the produced radionuclides were also deducted from the measured cross sections.

  1. Slow running of the Gradient Flow coupling from 200 MeV to 4 GeV in $N_{\\rm f}=3$ QCD

    CERN Document Server

    Dalla Brida, Mattia; Korzec, Tomasz; Ramos, Alberto; Sint, Stefan; Sommer, Rainer

    2017-01-25

    Using a finite volume Gradient Flow (GF) renormalization scheme with Schr\\"odinger Functional (SF) boundary conditions, we compute the non-perturbative running coupling in the range $2.2 \\lesssim {\\bar g}_\\mathrm{GF}^2(L) \\lesssim 13$. Careful continuum extrapolations turn out to be crucial to reach our high accuracy. The running of the coupling is always between one-loop and two-loop and very close to one-loop in the region of $200\\,{\\rm MeV} \\lesssim \\mu=1/L \\lesssim 4\\,{\\rm GeV}$. While there is no convincing contact to two-loop running, we match non-perturbatively to the SF coupling with background field. In this case we know the $\\mu$ dependence up to $\\sim 100\\,{\\rm GeV}$ and can thus connect to the $\\Lambda$-parameter.

  2. Electron-lattice energy relaxation in laser-excited thin-film Au-insulator heterostructures studied by ultrafast MeV electron diffraction

    Directory of Open Access Journals (Sweden)

    K. Sokolowski-Tinten

    2017-09-01

    Full Text Available We apply time-resolved MeV electron diffraction to study the electron-lattice energy relaxation in thin film Au-insulator heterostructures. Through precise measurements of the transient Debye-Waller-factor, the mean-square atomic displacement is directly determined, which allows to quantitatively follow the temporal evolution of the lattice temperature after short pulse laser excitation. Data obtained over an extended range of laser fluences reveal an increased relaxation rate when the film thickness is reduced or the Au-film is capped with an additional insulator top-layer. This behavior is attributed to a cross-interfacial coupling of excited electrons in the Au film to phonons in the adjacent insulator layer(s. Analysis of the data using the two-temperature-model taking explicitly into account the additional energy loss at the interface(s allows to deduce the relative strength of the two relaxation channels.

  3. On Range of Skill

    DEFF Research Database (Denmark)

    Hansen, Thomas Dueholm; Miltersen, Peter Bro; Sørensen, Troels Bjerre

    2008-01-01

    size (and doubly exponential in its depth). We also provide techniques that yield concrete bounds for unbalanced game trees and apply these to estimate the Range of Skill of Tic-Tac-Toe and Heads-Up Limit Texas Hold'em Poker. In particular, we show that the Range of Skill of Tic-Tac-Toe is more than...

  4. Range Scheduling Aid (RSA)

    Science.gov (United States)

    Logan, J. R.; Pulvermacher, M. K.

    1991-01-01

    Range Scheduling Aid (RSA) is presented in the form of the viewgraphs. The following subject areas are covered: satellite control network; current and new approaches to range scheduling; MITRE tasking; RSA features; RSA display; constraint based analytic capability; RSA architecture; and RSA benefits.

  5. Home range and travels

    Science.gov (United States)

    Stickel, L.F.; King, John A.

    1968-01-01

    The concept of home range was expressed by Seton (1909) in the term 'home region,' which Burr (1940, 1943) clarified with a definition of home range and exemplified in a definitive study of Peromyscus in the field. Burt pointed out the ever-changing characteristics of home-range area and the consequent absence of boundaries in the usual sense--a finding verified by investigators thereafter. In the studies summarized in this paper, sizes of home ranges of Peromyscus varied within two magnitudes, approximately from 0.1 acre to ten acres, in 34 studies conducted in a variety of habitats from the seaside dunes of Florida to the Alaskan forests. Variation in sizes of home ranges was correlated with both environmental and physiological factors; with habitat it was conspicuous, both in the same and different regions. Food supply also was related to size of home range, both seasonally and in relation to habitat. Home ranges generally were smallest in winter and largest in spring, at the onset of the breeding season. Activity and size also were affected by changes in weather. Activity was least when temperatures were low and nights were bright. Effects of rainfall were variable. Sizes varied according to sex and age; young mice remained in the parents' range until they approached maturity, when they began to travel more widely. Adult males commonly had larger home ranges than females, although there were a number of exceptions. An inverse relationship between population density and size of home range was shown in several studies and probably is the usual relationship. A basic need for activity and exploration also appeared to influence size of home range. Behavior within the home range was discussed in terms of travel patterns, travels in relation to home sites and refuges, territory, and stability of size of home range. Travels within the home range consisted of repeated use of well-worn trails to sites of food, shelter, and refuge, plus more random exploratory travels

  6. Relative biological effectiveness of the 60-MeV therapeutic proton beam at the Institute of Nuclear Physics (IFJ PAN) in Kraków, Poland.

    Science.gov (United States)

    Słonina, Dorota; Biesaga, Beata; Swakoń, Jan; Kabat, Damian; Grzanka, Leszek; Ptaszkiewicz, Marta; Sowa, Urszula

    2014-11-01

    The aim of the study was to determine the relative biological effectiveness (RBE) of a 60-MeV proton radiotherapy beam at the Institute of Nuclear Physics, Polish Academy of Sciences (IFJ PAN) in Kraków, the first one to operate in Poland. RBE was assessed at the surviving fractions (SFs) of 0.01, 0.1, and 0.37, for normal human fibroblasts from three cancer patients. The cells were irradiated near the Bragg peak of the pristine beam and at three depths within a 28.4-mm spread-out Bragg peak (SOBP). Reference radiation was provided by 6-MV X-rays. The mean RBE value at SF = 0.01 for fibroblasts irradiated near the Bragg peak of pristine beam ranged between 1.06 and 1.15. The mean RBE values at SF = 0.01 for these cells exposed at depths of 2, 15, and 27 mm of the SOBP ranged between 0.95-1.00, 0.97-1.02, and 1.05-1.11, respectively. A trend was observed for RBE values to increase with survival level and with depth in the SOBP: at SF = 0.37 and at the depth of 27 mm, RBE values attained their maximum (1.19-1.24). The RBE values estimated at SF = 0.01 using normal human fibroblasts for the 60-MeV proton radiotherapy beam at the IFJ PAN in Kraków are close to values of 1.0 and 1.1, used in clinical practice.

  7. Deuteron-induced reactions on Ni isotopes up to 60 MeV

    Science.gov (United States)

    Avrigeanu, M.; Šimečková, E.; Fischer, U.; Mrázek, J.; Novak, J.; Štefánik, M.; Costache, C.; Avrigeanu, V.

    2016-07-01

    Background: The high complexity of the deuteron-nucleus interaction from the deuteron weak binding energy of 2.224 MeV is also related to a variety of reactions induced by the deuteron-breakup (BU) nucleons. Thus, specific noncompound processes as BU and direct reactions (DR) make the deuteron-induced reactions so different from reactions with other incident particles. The scarce consideration of only pre-equilibrium emission (PE) and compound-nucleus (CN) mechanisms led to significant discrepancies with experimental results so that recommended reaction cross sections of high-priority elements as, e.g., Ni have mainly been obtained by fit of the data. Purpose: The unitary and consistent BU and DR account in deuteron-induced reactions on natural nickel may take advantage of an extended database for this element, including new accurate measurements of particular reaction cross sections. Method: The activation cross sections of 64,61,60Cu, Ni,5765, and 55,56,57,58,59m,60Co nuclei for deuterons incident on natural Ni at energies up to 20 MeV, were measured by the stacked-foil technique and high-resolution gamma spectrometry using U-120M cyclotron of CANAM, NPI CAS. Then, within an extended analysis of deuteron interactions with Ni isotopes up to 60 MeV, all processes from elastic scattering until the evaporation from fully equilibrated compound system have been taken into account while an increased attention is paid especially to the BU and DR mechanisms. Results: The deuteron activation cross-section analysis, completed by consideration of the PE and CN contributions corrected for decrease of the total-reaction cross section from the leakage of the initial deuteron flux towards BU and DR processes, is proved satisfactory for the first time to all available data. Conclusions: The overall agreement of the measured data and model calculations validates the description of nuclear mechanisms taken into account for deuteron-induced reactions on Ni, particularly the BU and

  8. Preliminary investigation of scintillator materials properties: SrI{sub 2}:Eu, CeBr{sub 3} and GYGAG:Ce for gamma rays up to 9 MeV

    Energy Technology Data Exchange (ETDEWEB)

    Giaz, A., E-mail: agnese.giaz@mi.infn.it [INFN Milano, Via Celoria 16, 20133 Milano (Italy); Hull, G. [Institut de Physique Nucleaire d' Orsay, 15 rue Georges Clemenceau, 91406 Orsay Cedex (France); Fossati, V. [Università degli Studi di Milano, Physics Dept., Via Celoria 16, 20133 Milano (Italy); Cherepy, N. [Lawrence Livermore National Laboratory, Livermore, CA 94550 (United States); Camera, F. [INFN Milano, Via Celoria 16, 20133 Milano (Italy); Università degli Studi di Milano, Physics Dept., Via Celoria 16, 20133 Milano (Italy); Blasi, N.; Brambilla, S.; Coelli, S.; Million, B. [INFN Milano, Via Celoria 16, 20133 Milano (Italy); Riboldi, S. [INFN Milano, Via Celoria 16, 20133 Milano (Italy); Università degli Studi di Milano, Physics Dept., Via Celoria 16, 20133 Milano (Italy)

    2015-12-21

    In this work we measured the performance of a 2″×2″ cylindrical tapered crystal of SrI{sub 2}:Eu, a 2″×3″ cylindrical sample of CeBr{sub 3} and a 2″×0.3″ cylindrical sample of GYGAG:Ce. These scintillators are prototypes in volume or material and were provided by the Lawrence Livermore National Laboratory and by the Institut de Physique Nucléaire d'Orsay. The gamma-ray energy resolution was measured in the energy range of 0.1–9 MeV using different sources. Each scintillator was scanned along x, y and z axes, using a 400 MBq collimated {sup 137}Cs source. Owing to the GYGAG:Ce thickness, it was not possible to obtain the value of the energy resolution at 9 MeV and to scan the crystal along the z axis. The 662 keV full energy peak position and its FWHM were measured relative to the full energy peaks positions produced by a non-collimated {sup 88}Y source. The signals of the detectors were additionally digitized and compared, up to 9 MeV, using a 12 bit LeCroy 600 MHz oscilloscope.

  9. Measurement of np elastic scattering spin-spin correlation parameters at 484, 634, and 788 MeV

    Energy Technology Data Exchange (ETDEWEB)

    Garnett, R.W.

    1989-03-01

    The spin-spin correlation parameters C/sub LL/ and C/sub SL/ were measured for np elastic scattering at the incident neutron kinetic energy of 634 MeV. Good agreement was obtained with previously measured data. Additionally, the first measurement of the correlation parameter C/sub SS/ was made at the three energies, 484, 634, and 788 MeV. It was found that the new values, in general, do not agree well with phase shift predictions. A study was carried out to determine which of the isospin-0 partial waves will be affected by this new data. It was found that the /sup 1/P/sub 1/ partial wave will be affected significantly at all three measurement energies. At 634 and 788 MeV, the /sup 3/S/sub 1/ phase shifts will also change. 29 refs., 21 figs., 16 tabs.

  10. A simple and powerful XY-Type current monitor for 30 MeV IPEN/CNEN-SP cyclotron

    Energy Technology Data Exchange (ETDEWEB)

    Barcellos, Henrique; Matsuda, Hylton; Sumyia, Luiz Carlos do A.; Junqueira, Fernando de C.; Costa, Osvaldo L. da, E-mail: hbolivei@ipen.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2017-11-01

    A water-cooled XY-type current monitor was designed and built in the Cyclotrons Laboratory of the Nuclear and Energy Research Institute (IPEN). It is a very simple design and easily adaptable to the cyclotron beam lines. Tests were done demonstrating to be an instrument of great assistance in proton beam position along beam transport line and target port. Nowadays the XY-type current monitor has been widely used in {sup 18}F-FDG routine productions, employing irradiation system which were originally designed for productions on 18 MeV cyclotron accelerator only, however, applying the XY-type current monitor the target port may be exchanged between the 30 MeV and 18 MeV cyclotrons and the observed results are in perfect agreement with expected. (author)

  11. Channeling and coherent bremsstrahlung effects for relativistic positrons and electrons. [16 to 28 MeV, orientation

    Energy Technology Data Exchange (ETDEWEB)

    Walker, R. L.

    1976-03-22

    Channeling of positrons in single crystals of silicon was observed in transmission and scattering measurements for incident energies from 16 to 28 MeV. In addition, the spectral dependence upon crystal orientation of the forward coherent bremsstrahlung produced by beams of 28-MeV positrons and electrons incident upon a 5 ..mu..m thick single crystal of silicon was measured with a NaI photon spectrometer. Effects of channeling and perhaps of the nonvalidity of the first Born approximation were observed for beam directions near the (111) axis of the crystal, and coherent peaks near 0.5 MeV were observed for a compound interference direction, in agreement with first-order theoretical calculations. 32 fig.

  12. Van Allen Probes observations of prompt MeV radiation belt electron acceleration in nonlinear interactions with VLF chorus

    Science.gov (United States)

    Foster, J. C.; Erickson, P. J.; Omura, Y.; Baker, D. N.; Kletzing, C. A.; Claudepierre, S. G.

    2017-01-01

    Prompt recovery of MeV (millions of electron Volts) electron populations in the poststorm core of the outer terrestrial radiation belt involves local acceleration of a seed population of energetic electrons in interactions with VLF chorus waves. Electron interactions during the generation of VLF rising tones are strongly nonlinear, such that a fraction of the relativistic electrons at resonant energies are trapped by waves, leading to significant nonadiabatic energy exchange. Through detailed examination of VLF chorus and electron fluxes observed by Van Allen Probes, we investigate the efficiency of nonlinear processes for acceleration of electrons to MeV energies. We find through subpacket analysis of chorus waveforms that electrons with initial energy of hundreds of keV to 3 MeV can be accelerated by 50 keV-200 keV in resonant interactions with a single VLF rising tone on a time scale of 10-100 ms.

  13. Two-color infrared FEL facility employing a 250-MeV linac injector of Saga synchrotron light source

    CERN Document Server

    Tomimasu, T; Koga, N; Hashiguchi, Y; Ochiai, Y; Ishibashi, M

    2001-01-01

    A two-color infrared free electron laser (FEL) facility is proposed. This FEL facility will employ a new 250-MeV linac injector of the Saga synchrotron light source (SLS). The linac has two operation modes: short macropulse mode of 1 mu s at 250 MeV is for injection to a 1.4-GeV storage ring and long macropulse mode of 13 mu s at 40 MeV is for the two-color FEL facility. The two-color FEL uses a single electron beam and simultaneously provides both infrared (IR) and far-IR laser pulses for pump-probe studies of quantum-well structures and studying vibrational relaxation of molecules. The Saga SLS will be operated in 2004 to promote material science, bio-medical and industrial applications in Kyushu.

  14. Excitation functions of (alpha,xn) reactions on (nat)Rb and (nat)Sr from threshold up to 26 MeV: possibility of production of (87)Y, (88)Y and (89)Zr.

    Science.gov (United States)

    Kandil, S A; Spahn, I; Scholten, B; Saleh, Z A; Saad, S M M; Coenen, H H; Qaim, S M

    2007-05-01

    Excitation functions were measured by the stacked-foil technique for (nat)Rb(alpha,xn)(87m,87m+g,88)Y and (nat)Sr(alpha,xn)(86,88,89)Zr reactions from their respective thresholds up to 26 MeV. The samples for irradiation were prepared by sedimentation and pellet pressing techniques. The measured data were compared with those available in the literature. From the excitation functions, integral yields of the products were calculated. The suitable energy ranges for the production of (87)Y and (88)Y via (nat)Rb(alpha,xn) processes and of (89)Zr via the (nat)Sr(alpha,xn) process are E(alpha)=26-->20 MeV, E(alpha)=26-->5 MeV and E(alpha)=20-->8.5 MeV, respectively. The respective yields amount to 8.2, 0.08 and 0.9 MBq/microA h. Production of (88)Y is feasible if a waiting time of about 2 months is allowed to let the impurities decay out. Also, (87)Y can be produced with a relatively low impurity of (88)Y. The yields of both (88)Y and (87)Y via the present routes are, however, appreciably lower than those via the (nat)Sr(p,xn) processes. There is a possibility to produce (89)Zr via the alpha-particle irradiation of (nat)Sr. The yield is rather low but would be considerably increased if enriched (86)Sr would be used as target material. The radionuclidic impurity levels in all the three products are discussed.

  15. High intensity proton beam transportation through fringe field of 70 MeV compact cyclotron to beam line targets

    Science.gov (United States)

    Zhang, Xu; Li, Ming; Wei, Sumin; Xing, Jiansheng; Hu, Yueming; Johnson, Richard R.; Piazza, Leandro; Ryjkov, Vladimir

    2016-06-01

    From the stripping points, the high intensity proton beam of a compact cyclotron travels through the fringe field area of the machine to the combination magnet. Starting from there the beams with various energy is transferred to the switching magnet for distribution to the beam line targets. In the design of the extraction and transport system for the compact proton cyclotron facilities, such as the 70 MeV in France and the 100 MeV in China, the space charge effect as the beam crosses the fringe field has not been previously considered; neither has the impact on transverse beam envelope coupled from the longitudinal direction. Those have been concerned much more with the higher beam-power because of the beam loss problem. In this paper, based on the mapping data of 70 MeV cyclotron including the fringe field by BEST Cyclotron Inc (BEST) and combination magnet field by China Institute of Atomic Energy (CIAE), the beam extraction and transport are investigated for the 70 MeV cyclotron used on the SPES project at Istituto Nazionale di Fisica Nucleare, Laboratori Nazionali di Legnaro (INFN-LNL). The study includes the space charge effect and longitudinal and transverse coupling mentioned above, as well as the matching of beam optics using the beam line for medical isotope production as an example. In addition, the designs of the ±45° switching magnets and the 60° bending magnet for the extracted beam with the energy from 35 MeV to 70 MeV have been made. Parts of the construction and field measurements of those magnets have been done as well. The current result shows that, the design considers the complexity of the compact cyclotron extraction area and fits the requirements of the extraction and transport for high intensity proton beam, especially at mA intensity levels.

  16. Research Programme for the 660 Mev Proton Accelerator Driven MOX-Plutonium Subcritical Assembly

    CERN Document Server

    Barashenkov, V S; Buttseva, G L; Dudarev, S Yu; Polanski, A; Puzynin, I V; Sissakian, A N

    2000-01-01

    The paper presents a research programme of the Experimental Acclerator Driven System (ADS), which employs a subcritical assembly and a 660 MeV proton acceletator operating at the Laboratory of Nuclear Problems of the JINR, Dubna. MOX fuel (25% PuO_2 + 75% UO_2) designed for the BN-600 reactor use will be adopted for the core of the assembly. The present conceptual design of the experimental subcritical assembly is based on a core of a nominal unit capacity of 15 kW (thermal). This corresponds to the multiplication coefficient k_eff = 0.945, energetic gain G = 30 and the accelerator beam power 0.5 kW.

  17. Neutron elastic scattering on lead at 3.0 MeV

    Energy Technology Data Exchange (ETDEWEB)

    Chavez, E.; Huerta, A.; Ortiz, M.E.; Rodriguez, P.; Favela, F.; Marin, D. [lFUNAM, 04510 Mexico D.F. (Mexico); Moreno, E.; Murillo, G.; Policroniades, R.; Varela, A. [Laboratorio del Acelerador, INlN, AP 18-1027, Mexico D.F. (Mexico); Barron P, L. [Arizona State University, P.O. Box 871504 Tempe, AZ 85287-1504 (United States)

    2007-12-15

    Recent interest on precise information of the elastic scattering of fast (MeV) neutrons on {sup 208}Pb revealed the lack of sufficient experimental information. In this work we present new data obtained at the EN-Tandem Accelerator Laboratory of the 'Instituto Nacional de Investigaciones Nucleares' (ININ). A tagged mono-energetic flux of neutrons is generated through the D(d,n){sup 3}He reaction by detecting and identifying the conjugated Helium particles. The neutron 'cone' produced this way is directed towards a {sup nat}Pb target. The angular distribution of the scattered neutrons is measured between five and twenty degrees relative to the neutron direction by an array of plastic scintillators. Comparison with the previous data and optical model calculations is presented. Future perspectives are discussed. (Author)

  18. Local heating induced by single MeV C60 ion impacts

    Science.gov (United States)

    Hayashi, H.; Matsuzaki, S.; Nakajima, K.; Narumi, K.; Saitoh, Y.; Tsujimoto, M.; Toulemonde, M.; Kimura, K.

    2017-09-01

    Gold and platinum nanoparticles of few-nm size were deposited on amorphous silicon oxide and amorphous silicon nitride films. These films were irradiated with 0.72 and 1.1 MeV C603+ ions. Local heating of these films induced by the single ion impact was evaluated by observing desorption of the nanoparticles from the target surfaces upon ion impact. It was found that the local heating at the exit surface is very sensitive to the film thickness. For thinner films, the observed local heating at the exit surface is enhanced compared to the entrance surface while the result is opposite for thicker films. The observed result can be well explained by the unified thermal spike model taking account of the broadening of the spatial distribution of constituent carbon ions during the passage across the film.

  19. An 800-MeV proton radiography facility for dynamic experiments

    CERN Document Server

    King, N S P; Adams, K; Alrick, K R; Amann, J F; Balzar, S; Barnes, P D J; Crow, M L; Cushing, S B; Eddleman, J C; Fife, T T; Flores, P; Fujino, D; Gallegos, R A; Gray, N T; Hartouni, E P; Hogan, G E; Holmes, V H; Jaramillo, S A; Knudsson, J N; London, R K; Lopez, R R; McDonald, T E; McClelland, J B; Merrill, F E; Morley, K B; Morris, C L; Naivar, F J; Parker, E L; Park, H S; Pazuchanics, P D; Pillai, C; Riedel, C M; Sarracino, J S; Shelley, F E J; Stacy, H L; Takala, B E; Thompson, R; Tucker, H E; Yates, G J; Ziock, H J; Zumbro, J D

    1999-01-01

    The capability has successfully been developed at the Los Alamos Nuclear Science Center (LANSCE) to utilize a spatially and temporally prepared 800 MeV proton beam to produce proton radiographs. A series of proton bursts are transmitted through a dynamic object and transported, via a unique magnetic lens system, to an image plane. The magnetic lens system permits correcting for the effects of multiple coulomb scattering which would otherwise completely blur the spatially transmitted information at the image plane. The proton radiographs are recorded either on a time integrating film plate or with a recently developed multi-frame electronic imaging camera system. The latter technique permits obtaining a time dependent series of proton radiographs with time intervals (modulo 358 ns) up to many microseconds and variable time intervals between images. One electronically shuttered, intensified, CCD camera is required per image. These cameras can detect single protons interacting with a scintillating fiber optic ar...

  20. Filamentation control and collimation of laser accelerated MeV protons

    Science.gov (United States)

    Ramakrishna, B.; Tayyab, M.; Bagchi, S.; Mandal, T.; Upadhyay, A.; Weng, S. M.; Murakami, M.; Cowan, T. E.; Chakera, J. A.; Naik, P. A.; Gupta, P. D.

    2015-12-01

    We demonstrate experimentally that the proton beam filamentation in dense plasma can be controlled in multi-layered (Al-CH-Al) sandwich targets. We observe up to three-fold reduction in the MeV proton beam divergence (~12°) from these targets as a result of decrease in filamentary structures in the proton beam profile. Strong self-generated resistive magnetic fields in targets with a high-Z transport layer are mainly responsible for this observed effect. Enhancement in the proton flux and energy is also observed from these targets. Supported by a matching 2D particle-in-cell (PIC) simulation and theoretical considerations, we suggest that these targets can be very effectively implemented to collimate proton beams useful for ion oncology applications or advanced fast igniter approach of inertial confinement fusion (ICF).