WorldWideScience

Sample records for 50-130 mev range

  1. SCANDAL -- A facility for elastic neutron scattering studies in the 50--130 MeV range

    International Nuclear Information System (INIS)

    A facility for detection of scattered neutrons in the energy interval 50--130 MeV, SCANDAL (SCAttered Nucleon Detection AssembLy), has recently been installed at the 20--180 MeV neutron beam facility of the The Svedberg Laboratory, Uppsala. It is primarily intended for studies of elastic neutron scattering, but can be used for the (n,p) and (n,d) reaction experiments as well. The performance of the spectrometer is illustrated in measurements of the (n,p) and (n,n) reactions on 1H and 12C. In addition, the neutron beam facility is described in some detail

  2. Recoil proton polarization of neutral pion photoproduction from proton in the energy range between 400 MeV and 1142 MeV

    International Nuclear Information System (INIS)

    The recoil proton polarization of the reaction γp → π0p were measured at a C.M. angle of 1000 for incident photon energies between 451 and 1106 MeV, and at an angle of 1300 for energies from 400 MeV to 1142 MeV. One photon decayed from a π0-meson and a recoil proton were detected in coincidence. Two kinds of polarization scatterers were employed. In the range of proton kinetic energy less than 420 MeV and higher than 346 MeV, carbon plates and liquid hydrogen were used for determining the polarization. Results are compared with recent phenomenological analyses. From the Comparison between the present data and the asymmetry data given by the polarized target, the contribution of the invariant amplitudes A3 can be estimated to be small at 1000. (author)

  3. 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.

  4. Study of the thermal oxidation of titanium and zirconium under argon ion irradiation in the low MeV range (E = 15 MeV)

    International Nuclear Information System (INIS)

    We have shown that argon ion irradiation between 1 and 15 MeV produces damage on both titanium and zirconium surfaces, taking the form of accelerated oxidation and/or craterization effects, varying as a function of the projectile energy and the annealing atmosphere (temperature and pressure) simulating the environmental conditions of the fuel/cladding interface of PWR fuel rods. Using AFM, we have shown that the titanium and zirconium surface is attacked under light argon ion bombardment at high temperature (up to 500 C) in weakly oxidizing medium (under rarefied dry air pressure ranging from 5,7 10-5 Pa to 5 10-3 Pa) for a fixed fluence of about 5 1014 ions.cm-2. We observed the formation of nano-metric craters over the whole titanium surface irradiated between 2 and 9 MeV and the whole zirconium surface irradiated at 4 MeV, the characteristics of which vary depending on the temperature and the pressure. In the case of the Ar/Ti couple, the superficial damage efficiency increases when the projectile energy decreases from 9 to 2 MeV. Moreover, whereas the titanium surface seems to be transparent under the 15-MeV ion beam, the zirconium surface exhibits numerous micrometric craters surrounded by a wide halo. The crater characteristics (size and superficial density) differ significantly from that observed both in the low energy range (keV) where the energy losses are controlled by ballistic collisions (Sn) and in the high energy range (MeV - GeV) where the energy losses are controlled by electronic excitations (Se), which was not completely unexpected in this intermediate energy range for which combined Sn - Se stopping power effects are possibly foreseen. Using XPS associated to ionic sputtering, we have shown that there is an irradiation effect on thermal oxidation of titanium, enhanced under the argon ion beam between 2 and 9 MeV, and that there is also an energy effect on the oxide thickness and stoichiometry. The study conducted using Spectroscopic Ellipsometry

  5. Turbulent transport of MeV range cyclotron heated minorities as compared to alpha particles

    CERN Document Server

    Pusztai, István; Kazakov, Yevgen O; Fülöp, Tünde

    2016-01-01

    We study the turbulent transport of an ion cyclotron resonance heated (ICRH), MeV range minority ion species in tokamak plasmas. Such highly energetic minorities, which can be produced in the three ion minority heating scheme [Ye. O. Kazakov et al. (2015) Nucl. Fusion 55, 032001], have been proposed to be used to experimentally study the confinement properties of fast ions without the generation of fusion alphas. We compare the turbulent transport properties of ICRH ions with that of fusion born alpha particles. Our results indicate that care must be taken when conclusions are drawn from experimental results: While the effect of turbulence on these particles is similar in terms of transport coefficients, differences in their distribution functions - ultimately their generation processes - make the resulting turbulent fluxes different.

  6. Neutron production in the energy range 7 to 12 MeV using a gas-target

    International Nuclear Information System (INIS)

    A gas-target for operation at a tandem-accelerator is described. Using the DD-reaction, an energy range of neutrons between 7 and 12 MeV can be realised. Construction and operation are described in detail. For neutron energies below 9 MeV the neutron source is almost monoenergetic; above this energy the deuteron break-up limits the monoenergetic behaviour. (author)

  7. 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.

  8. 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...

  9. Neutron cross-sections for 55Mn in the energy range from 0.2 to 22 MeV

    OpenAIRE

    RAHMAN, Abul Khaer Mohammad Rezaur

    2012-01-01

    Neutron total and differential elastic scattering cross-sections for 55Mn nucleus was calculated from different global spherical optical potential (SOP) sets for different neutron energies ranging from 0.2 MeV to 22 MeV using the well known computer program SCAT-2 on an IBM PC-AT. In addition, the angular distributions of elastically scattered neutrons at different neutron energies were calculated. The results were compared with those of the experimental data obtained from the EXFOR d...

  10. 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.

    1969-01-01

    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 d

  11. Long-Range Alpha Particle Emission in the Fission of U235 by 3-MeV Neutrons

    International Nuclear Information System (INIS)

    The energy and angular distribution of long-range alpha particles emitted in the fission of U235 induced by 3-MeV neutrons have been measured. The alpha panicles were detected by solid-state detector and the fission fragments were detected by a gas scintillation counter. The neutrons were produced by the T (p, n) He3 reaction using a 5.5- MeV Van de Graaff accelerator. About 3000 fission events accompanied by the emission of a high-energy alpha panicle were recorded. The most probable energy of the alpha particles is between 15-16 MeV. and the energy distribution has a full width at half maximum of about D MeV, which is the same as observed in tliermal- neutron fission. The angular distribution of the long-range alpha panicles with respect to the incident neutron direction was found to be forward-peaked, in agreement with previous work on alpha emission in 14-MeV neutron-induced fission of LP. At angles of 0° and 90° with respect to the incident neutron direction the alpha panicles were detected with an angular spread of about ± 25°. The anisotropy [Nα(0°)/ Nα(90°)] was found to be 1.320 ± 0.12. This value is in agreement with the anisotropy calculated on the basis of statistical evaporation of panicles. The results of the present investigation are consistent with the hypothesis that the emission of long-range alpha panicles in fission is an evaporation process. The implications of the results of this work and of other recent investigations on long-range alpha emission are discussed. (author)

  12. Reaction cross sections for protons in the energy range 220-570 MeV

    CERN Document Server

    Renberg, P U; Measday, D F; Pepin, M; Serre, Claude; Schwaller, P

    1972-01-01

    Proton reaction cross sections have been measured for targets of natural isotopic abundance of the following elements and compounds: He, Be, C, Al, Fe, Cu, Ge, Sn, Pb, H/sub 2/O, B/sub 4/C and NaI. Data for proton energies between 220 and 570 MeV have been obtained with two types of transmission-counter assembly. The total errors are of the order of +or-3%. A slight increase of the reaction cross sections with energy is observed for most of the elements studied. The results interpreted in terms of the semi-classical theory of reaction cross section as function of energy clearly demonstrate the onset of pion- production above 250 MeV. (32 refs).

  13. Compton scattering from 12C using tagged photons in the energy range 65 - 115 MeV

    CERN Document Server

    Myers, L S; Preston, M F; Anderson, M D; Annand, J R M; Boselli, M; Briscoe, W J; Brudvik, J; Capone, J I; Feldman, G; Fissum, K G; Hansen, K; Henshaw, S S; Isaksson, L; Jebali, R; Kovash, M A; Lewis, K; Lundin, M; MacGregor, I J D; Middleton, D G; Mittelberger, D E; Murray, M; Nathan, A M; Nutbeam, S; O'Rielly, G V; Schröder, B; Seitz, B; Stave, S C; Weller, H R

    2014-01-01

    Elastic scattering of photons from 12C has been investigated using quasi-monoenergetic tagged photons with energies in the range 65 - 115 MeV at laboratory angles of 60 deg, 120 deg, and 150 deg at the Tagged-Photon Facility at the MAX IV Laboratory in Lund, Sweden. A phenomenological model was employed to provide an estimate of the sensitivity of the 12C(g,g)12C cross section to the bound-nucleon polarizabilities.

  14. DM2 results on e+e- annihilation into multihadrons in the 1350-2400 MeV energy range

    International Nuclear Information System (INIS)

    We present preliminary results on the study of e+e- annihilation into π+π-π+π-, π+π-π0π0, π+π-π0, π+π-π+π-π0, K+K-π+π- and Ks0K±π-+ in the 1350-2400 MeV energy range. Data have been collected with the DM2 detector at DCI, the Orsay colliding ring, and refer to about 2 pb-1 integrated luminosity

  15. Evaluation of 242Pu data for the incident neutron energy range 5-20 MeV

    International Nuclear Information System (INIS)

    Models, procedures and parameters are presented for the calculation of neutron cross sections, the neutron angular distributions and the neutron energy distributions of 242Pu in the energy range 5-20 MeV. The interaction takes place through direct interaction and compound nucleus mechanism. For heavy deformed nucleus the direct interaction was treated with the coupled channel process, using the ECIS code. For the compound nucleus mechanism, a statistical treatment was used for fission, neutron elastic and inelastic scattering, radiative capture, (n,2n), (n,3n), (n,4n) cross section calculations, using the GNASH code. (R.P.)

  16. Gamma Ray Buildup Factor for Finite Media in Energy Range (4-10) MeV for Al and Pb

    International Nuclear Information System (INIS)

    A computer program based on Monte Carlo method had been designed and written in visual basic computer language and utilized for simulating the classic problem of gamma ray beam incident on finite plane slabs of absorbing materials.The source geometry adopted in this program is plane normal source. Dose buildup factor of gamma photons in the absence and presence pair production effect have been calculated in the energy range (4-10) MeV for Aluminum and Lead up to 5 mean free path thickness.Dose buildup factor in the presence of pair production is higher than dose buildup factor in the absence of pair production effect.The deviation between the values of dose buildup factor in the presence and absence pair production is increased when the energy is increased within the studied energy range because the cross section for pair production is increased within the studied energy range

  17. Range and energy loss rate of 118 MeV 28Si in some polymers

    International Nuclear Information System (INIS)

    In the present work, range and energy loss rate of 28Si in four dielectric track detectors viz: Makrofol-KG (MFKG), Makrofol-G (MFG), Triafol-BN (TBN) and LR-115 (cellulose nitrate) have been measured. To calculate these parameters, a curve fitting method was proved to be very useful and easier with more accuracy. (author)

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

    Science.gov (United States)

    Sjue, S. K. L.; Mariam, F. G.; Merrill, F. E.; Morris, C. L.; Saunders, A.

    2016-01-01

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

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

    CERN Document Server

    Ditrói, 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) 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.

  20. 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.

  1. Stopping power of palladium for protons in the energy range 0.300-3.100 MeV

    Science.gov (United States)

    Miranda, P. A.; Sepúlveda, A.; Morales, J. R.; Rodriguez, T.; Burgos, E.; Fernández, H.

    2014-01-01

    The stopping power of palladium for protons has been measured using the transmission method with an overall uncertainty of around 5% over the energy range Ep=(0.300-3.100) MeV. These stopping power data are then compared to stopping power values calculated by the SRIM-2010 code and to those derived from a model based on the dielectric formalism. Subsequently, and within the framework of the modified Bethe-Bloch theory, this stopping power data were used for extracting Pd target mean excitation and ionization potential, (I = 468 ± 5 eV), and Barkas effect parameter, (b = 1.51 ± 0.06). A good agreement is found between the obtained results and values reported in literature.

  2. 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.

  3. Stopping power of palladium for protons in the energy range 0.300–3.100 MeV

    Energy Technology Data Exchange (ETDEWEB)

    Miranda, P.A., E-mail: pjmirand@gmail.com; Sepúlveda, A.; Morales, J.R.; Rodriguez, T.; Burgos, E.; Fernández, H.

    2014-01-01

    The stopping power of palladium for protons has been measured using the transmission method with an overall uncertainty of around 5% over the energy range E{sub p}=(0.300–3.100) MeV. These stopping power data are then compared to stopping power values calculated by the SRIM-2010 code and to those derived from a model based on the dielectric formalism. Subsequently, and within the framework of the modified Bethe–Bloch theory, this stopping power data were used for extracting Pd target mean excitation and ionization potential, (I = 468 ± 5 eV), and Barkas effect parameter, (b = 1.51 ± 0.06). A good agreement is found between the obtained results and values reported in literature. It is worth mentioning that these are the first reported results for protons on palladium over this energy range, which is often used in IBA applications, such as Rutherford Backscattering Spectrometry (RBS) and Proton Induced X-ray Emission (PIXE)

  4. NUCLEAR CROSS-SECTION CALCULATIONS IN THE 1 MEV TO 5 GEV RANGE WITH COMBINED SEMI-CLASSICAL AND QUANTUM MECHANICAL MODELS

    Energy Technology Data Exchange (ETDEWEB)

    Guimaraes, F.B.

    2002-03-07

    In this work we describe neutron and proton induced reaction cross-sections for iron produced by the codes TNG and CEM95 in the 5 to 300 MeV energy range. TNG calculations cover the 5-90 MeV range, while CEM95 covers the 50-300 MeV high energy range. The two codes show some disagreements in the overlap energy range, both among themselves and with the experimental data, which are presently being addressed. The experimental data used are from NNDC and/or from LA150 NSE references. We also describe some developments for combining TNG and CEM95 into a new code called CETNG (Cascade Exciton TNG).

  5. 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.

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

    CERN Document Server

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

    2016-01-01

    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 40 MeV up to 50 MeV. 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 37-50 MeV 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 TALYS1.6 nuclear model code as listed in the on-line library TENDL-2014.

  7. Proton Inelastic Mean Free Path in a Group of Organic Materials in 0.05-10 MeV Range

    Institute of Scientific and Technical Information of China (English)

    TAN Zhen-Yu; XIA Yue-Yuan; ZHAO Ming-Wen; LIU Xiang-Dong

    2010-01-01

    @@ Inelastic mean free paths (MFPs) of 0.05-10 MeV protons in a group of 10 organic compounds are systematically calculated.The calculations are based on the method newly derived from the Ashley optical-data model and from the higher-order correction terms in stopping power calculations.Especially,in this method the new and empirical Bloch correction for the inelastic MFP is given.An evaluation for the optical energy loss function is incorporated into the present calculatious because of the lack of available experimental optical data for the considered organic compounds expect for kapton.The proton inelastic MFPs for these 10 organic compounds in the energy range from 0.05 to 10 Me V are presented here for the first time,and the combination of these inelastic MFP data and our previous data of stopping power calculation for these bioorganic compounds may form a useful database for Monte Carlo track-structure studies of various radiation effects on these materials.

  8. Finite range distorted wave analysis of 101.3 MeV 16O(p, pd)14N* reaction

    International Nuclear Information System (INIS)

    Experimental and theoretical studies of cluster knockout reactions have been progressing for the past several decades. This is to study the cluster structure as well as to yield the cluster spectroscopic factor in the light-medium mass nuclei using quasi-free (p, pα), (α, 2α), (p, pd), (α, αd) type of reactions. The spectroscopic factors deduced from the (α, 2α) reactions are found be almost 100 times larger than expected from the conventional shell model estimates. These values were deduced by comparing the experimental data with the predictions of the conventional Zero Range-Distorted Wave Impulse Approximation (ZR-DWIA) calculations. Analysis using the FR-DWIA formalism has been performed for the 101.3 MeV 16O(p, pd)14N* quasi-free reaction using all-through attractive (A) and an L-dependent attractive plus repulsive core (A+R) (of 2.5 fm) between the p and d potential

  9. Experimental investigation of the 19F( n, α)16N reaction excitation function in the neutron energy range of 4 to 7.35 MeV

    Science.gov (United States)

    Bondarenko, I. P.; Khryachkov, V. A.; Ivanova, T. A.; Kuz'minov, B. D.; Semenova, N. N.; Sergachev, A. I.

    2013-07-01

    The interaction of neutrons with light nuclei study is of interest for understanding nuclear-reaction mechanisms. Fluorine nuclei are worth particular attention because they are abundant in the core of the promising molten-salt reactors and can noticeably affect the chain reaction kinetics. In this work we have experimentally investigated the 19F( n, α)16N reaction cross-section at neutron energies ranging from 4 to 7.35 MeV.

  10. 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) re...

  11. Calculation of SF6-/SF6 and Cl-/CFCl3 electron attachment cross sections in the energy range 0-100 meV

    Science.gov (United States)

    Chutjian, A.

    1982-01-01

    Electron attachment cross sections for the processes SF6-/SF6 and Cl-/CFCl3 are calculated in a local theory using a model in which diatomic-like potential energy curves for the normal modes are constructed from available spectroscopic data. Thermally populated vibrational and rotational levels are included. Good agreement is found with experimental cross sections in the energy range 5-100 meV for a particular choice of potential energy curve parameters.

  12. Au, Bi, Co and Nb cross-section measured by quasimonoenergetic neutrons from p + 7Li reaction in the energy range of 18-36 MeV

    Science.gov (United States)

    Majerle, M.; Bém, P.; Novák, J.; Šimečková, E.; Štefánik, M.

    2016-09-01

    Au, Bi, Co and Nb samples were irradiated several times with quasi-monoenergetic neutrons from p + 7Li reaction in the energy range of 18-36 MeV. The activities of the samples were measured with the HPGe detector and the reaction rates were calculated. The cross-sections were extracted using the SAND-II method with the reference cross-sections from the EAF-2010 database. The uncertainties of the final results are discussed.

  13. Experimental SF6/-//SF6 and Cl/-//CFC13 electron-attachment cross sections in the energy range 0-200 meV

    Science.gov (United States)

    Chutjian, A.

    1981-01-01

    Experimental cross sections for the electron-attachment processes for SF6(-)/SF6 and Cl(-)/CFl3 are reported in the energy range 0-200 meV by normalizing each attachment line shape to measurement of a thermal rate coefficient. When the same ion states are detected, good agreement is found between present values, for which a monoenergetic electron source is used, and swarm-unfolded results. The present data constitute a new limit for cross sections reported at high resolution at the lowest electron energy.

  14. To calculating the gamma radiation interaction coefficients by an interpolation method in the 0.02-2 MeV energy range

    International Nuclear Information System (INIS)

    Interpolation formula earlier used for determining linear coefficients of gamma radiation attenuation in a substance is applied for determining mass coefficients of attenuation without regard for coherent scattering and mass coefficients of interaction due to incoherent scattering on bound electrons as well as mass coefficients of energy absorption. It is concluded that approximation error for 0.02-2 MeV energy range doesn't exceed 1.5 % except for several points for which the difference constitutes 2.5-3 %

  15. Responses of conventional and extended-range neutron detectors in mixed radiation fields around a 150-MeV electron LINAC

    International Nuclear Information System (INIS)

    This study analyzed the responses of two types of neutron detector in mixed gamma-ray and neutron radiation fields around a 150-MeV electron linear accelerator (LINAC). The detectors were self-assembled, high efficiency, and designed in two configurations: (1) a conventional moderated-type neutron detector based on a large cylindrical He-3 proportional counter; and (2) an extended-range version with an embedded layer of lead in the moderator to increase the detector’s sensitivity to high-energy neutrons. Two sets of the detectors were used to measure neutrons at the downstream and lateral locations simultaneously, where the radiation fields differed considerably in intensities and spectra of gamma rays and neutrons. Analyzing the detector responses through a comparison between calculations and measurements indicated that not only neutrons but also high-energy gamma rays (>5 MeV) triggered the detectors because of photoneutrons produced in the detector materials. In the lateral direction, the contribution of photoneutrons to both detectors was negligible. Downstream of the LINAC, where high-energy photons were abundant, photoneutrons contributed approximately 6% of the response of the conventional neutron detector; however, almost 50% of the registered counts of the extended-range neutron detector were from photoneutrons because of the presence of the detector rather than the effect of the neutron field. Dose readings delivered by extended-range neutron detectors should be interpreted cautiously when used in radiation fields containing a mixture of neutrons and high-energy gamma rays

  16. 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

  17. Differential cross section measurement of the elastic neutron-deuteron-scattering in the energy range 2.5-30 MeV

    International Nuclear Information System (INIS)

    The differential cross-section of the elastic D(n, n)D scattering has been measured in the energy range 2.5-30 MeV. A pulsed 'white' neutron beam from deuterons (Esub(d) approx. equal to 48 MeV) on natural uranium was collimated by bulk metal shielding in a approx. equal to 60 m long vacuum tube in the THETAsub(LAB) = O0-direction. The collimated neutrons were scattered from a partially and a totally deuterated scintillator. The mixed scatterer of hydrogen, deuterium and carbon provided the absolute calibration of the (n, d)-cross-section by the well-known (n, p)-cross-section. The scattered neutrons were detected by two detectors at 14 laboratory angles. Five parameters for each event were measured in coincidence, so that background reduction could be done. Additional contributions from multiple-scattering were determined by Monte-Carlo calculations. Twenty angular distributions were obtained with uncertainties between 2 and 6%. Some significant deviations from older measurements and from exact 3-body-calculations were found. Much importance was attached to the determination of the properties of the neutron-detectors, especially of the so-called 'black-detector'. (orig.)

  18. Calculated neutron-activation cross sections for E/sub n/ /le/ 100 MeV for a range of accelerator materials

    International Nuclear Information System (INIS)

    Activation problems associated with particle accelerators are commonly dominated by reactions of secondary neutrons produced in reactions of beam particles with accelerator or beam stop materials. Measured values of neutron-activation cross sections above a few MeV are sparse. Calculations with the GNASH code have been made for neutrons incident on all stable nuclides of a range of elements common to accelerator materials. These elements include B, C, N, O, Ne, Mg, Al, Si, P, S, Ar, K, Ca, Cr, Mn, Fe, Co, Ni, Cu, Zn, Zr, Mo, Nd, and Sm. Calculations were made for a grid of incident neutron energies extending to 100 MeV. Cross sections leading to the direct production of as many as 87 activation products for each of 84 target nuclide were tabulated on this grid of neutron energies, each beginning with the threshold for the product nuclide's formation. Multigrouped values of these cross sections have been calculated and are being integrated into the cross-section library of the REAC-2 neutron activation code. Illustrative cross sections are presented. 20 refs., 6 figs., 1 tab

  19. Measurement of the total photoabsorption cross section on a proton in the energy range 600-1500 MeV at the GRAAL

    Energy Technology Data Exchange (ETDEWEB)

    Bartalini, O. [Universita di Roma II Tor Vergata (Italy); Bellini, V. [Universita di Catania (Italy); Bocquet, J. P.; Calvat, P. [Laboratoire de Physique Subatomique et de Cosmologie, IN2P3 (France); D' Angelo, A. [Universita di Roma II Tor Vergata (Italy); Didelez, J.-P. [Institut de Physique Nucleaire d' Orsay, IN2P3 (France); Di Salvo, R.; Fantini, A. [Universita di Roma II Tor Vergata (Italy); Ghio, F.; Girolami, B. [INFN Sezione di Roma I (Italy); Guidal, M. [Institut de Physique Nucleaire d' Orsay, IN2P3 (France); Giusa, A. [Universita di Catania (Italy); Hourany, E. [Institut de Physique Nucleaire d' Orsay, IN2P3 (France); Ignatov, A. S. [Russian Academy of Sciences, Institute for Nuclear Research (Russian Federation); Kunne, R. [Institut de Physique Nucleaire d' Orsay, IN2P3 (France); Lapik, A. M.; Sandri, P. Levi [INFN Laboratori Nazionali di Frascati (Italy); Lleres, A. [Laboratoire de Physique Subatomique et de Cosmologie, IN2P3 (France); Moricciani, D. [Universita di Roma II Tor Vergata (Italy); Mushkarenkov, A. N. [Russian Academy of Sciences, Institute for Nuclear Research (Russian Federation); and others

    2008-01-15

    The total photoabsorption cross section on a free proton was measured at the GRAAL facility in the energy range E{sub {gamma}} = 600-1500 MeV. The large-aperture LAGRAN{gamma}E detector and a liquid hydrogen target were used in the experiment performed with a back-scattered Compton gamma beam. To improve the accuracy, two alternative methods were employed. First, a subtraction method of using empty-target measurements allowed the cross section {sigma}{sub tot} to be evaluated directly because of a low level of the electromagnetic background. Second, an algorithm for evaluating {sigma}{sub tot} on the basis of summing the dominating partial cross sections was developed. Experimental results obtained for {sigma}{sub tot} by the two methods are compared with existing data.

  20. Energy dependence of some neutron detector sensitivity in the energy range from 17 keV up to 1 MeV

    International Nuclear Information System (INIS)

    The results of experimental determination of sensitivity of neutron detectors used as dosimeters in the energy range from 17 keV to 1 MeV are presented. The measurements were performed in the EhG-2.5 accelerator. Monoenergetic neutrons were produced in the T (p, n)3He reaction at different proton energies. The detectors were placed at angles from 30 deg to 120 deg to proton beam direction. The detector sensitivity was evaluated by comparison of their values with those of the OVC-3M standard neutron counter. The obtained results could be used for determining energy dependences of sensitivities of detectors under study and for evaluating the errors of measurements of neutron doses in the radiation fields behind nuclear-physical installation shielding

  1. 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)

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

    Energy Technology Data Exchange (ETDEWEB)

    Amgarou, K. [Grup de Recerca en Radiacions Ionitzants, Departament de Fisica, Universitat Autonoma de Barcelona, E-08193 Bellaterra (Spain); Bedogni, R., E-mail: roberto.bedogni@lnf.infn.it [INFN-Istituto Nazionale di Fisica Nucleare, Laboratori Nazionali di Frascati, Via E. Fermi n. 40, 00044 Frascati (Italy); Domingo, C. [Grup de Recerca en Radiacions Ionitzants, Departament de Fisica, Universitat Autonoma de Barcelona, E-08193 Bellaterra (Spain); Esposito, A.; Gentile, A.; Carinci, G. [INFN-Istituto Nazionale di Fisica Nucleare, Laboratori Nazionali di Frascati, Via E. Fermi n. 40, 00044 Frascati (Italy); Russo, S. [INFN-Istituto Nazionale di Fisica Nucleare, Laboratori Nazionali del Sud, via S. Sofia 44, 95123 Catania (Italy)

    2011-10-21

    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 E<20 MeV if only polyethylene spheres are used, but can be extended to hundreds of MeV by including metal-loaded spheres (extended range BSS, indicated with ERBSS). With the aim of providing useful data to the scientific community involved in neutron measurements at hadron therapy facilities, an ERBSS experiment was carried out at the Centro di AdroTerapia e Applicazioni Nucleari Avanzate (CATANA) of INFN-LNS (Laboratori Nazionali del Sud), where a proton beam routinely used for ophthalmic cancer treatments is available. The 62 MeV beam was directed towards a PMMA phantom, simulating the patient, and two neutron measurement points were established at 0{sup o} and 90{sup o} with respect to the beam-line. Here the ERBSS of UAB (Universidad Autonoma de Barcelona-Grup de Fisica de les Radiacions) and INFN (Istituto Nazionale di Fisica 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

  3. Evaluation of the relative effectiveness of LiF-based TL detectors for electron radiotherapy beams over the energy range 6-20 MeV

    Energy Technology Data Exchange (ETDEWEB)

    Nahajowski, D.; Gora, E.; Rozwadowska-Bogusz, B.; Lesiak, J.; Polak, B.; Kabat, D.; Zawadzki, P. [Centre of Oncology, Maria Sklodowska-Curie Memorial Institute, Krakow Branch, Garncarska 11, 31-115 Krakow (Poland); Waligorski, M.P.R. [Centre of Oncology, Maria Sklodowska-Curie Memorial Institute, Krakow Branch, Garncarska 11, 31-115 Krakow (Poland); Institute of Nuclear Physics, Polish Academy of Sciences (IFJ PAN), Krakow (Poland)], E-mail: z5waligo@cyf-kr.edu.pl

    2008-02-15

    We have performed systematic measurements of the efficiency, C{sub E}=/, of MTS-N (LiF:Mg,Ti) and LiB (Li{sub 2}B{sub 4}O{sub 7}:Mn,Si) thermoluminescence (TL) detectors exposed to electron radiotherapy beams of nominal energy 6, 9, 12, 16 and 20 MeV relative to Co-60 or 6 MV photon beams ( is the average TL output of a batch of detectors exposed to a given dose of photon beam radiation or to a beam of electrons of energy E). The TL detectors were sintered pellets of 4.5 mm diameter and ca. 0.8 mm thickness. Detectors were exposed in water to 2 Gy at respective energy-dependent depths d{sub max} applied in clinical dosimetry. The obtained results were re-calculated versus mean electron energy in the beam at depths d{sub max}. We found that, for clinical purposes, both types of TL detectors show no energy dependence: presented as average values over the investigated energy range, for MTS-N detectors =1.07{+-}1.1% and for LiB =1.03{+-}1.7%. Thus, while no correction is required for dose values estimated by LiB TLDs, the under-response of MTS-N detectors exposed to a beam of electrons has to be corrected by about 7%. At mean energy of electrons in therapeutic electron beams below about 5 MeV a decline in the response of both types of TL detectors is observed.

  4. Electron-transfer reactions of fast Xe/sup n/+ ions with Xe in the energy range 15 keV to 1.6 MeV

    International Nuclear Information System (INIS)

    Electron-transfer cross sections for the reactions of Xe/sup n/+ (n = 1--4) with Xe atoms have been determined as a function of projectile-ion kinetic energy in the range 15 keV--1.6 MeV. For Xe/sup n/+ (n = 2, 3, 4), cross sections for sequential transfer of two or more electrons in single-ion--atom collisions have been obtained. These cross sections decrease with increasing number of electrons transferred. The observed insensitivity of cross sections to projectile kinetic energy in the range investigated follows the condition that the linear velocity of the ion is less than the orbital velocity of a valence electron in the slow-moving target atom. Attenuation cross sections for reactions of Xe/sup n/+ (n = 2, 3, 4) follow approximately a Z2/sub direct-sum/ charge dependence. A simple classical model based on Coulomb forces yields cross sections with a reasonable fit to the experimental data

  5. Excitation function of 59 Co (n, 2n) 58 Co process in the energy range 13.9-14.7 MeV

    International Nuclear Information System (INIS)

    The objective of the study is to measure the neutron cross sections for the 59 Co (n, 2n) 58 Co reaction around the 14 MeV energy region. Neutron activation cross section for almost all the nuclei, mostly in the medium energy region e.g., 7 to 20 MeV are reported in literature. Neutron cross section data around 14 MeV is of immense importance for the design of D + T fusion reactors. The accuracy of the cross section data at this energy region is a requirement for correct prediction of reactor parameters e.g., tritium breeding, nuclear heating, induced activity, etc. In order to perform the experiment, the Co-sample sandwiched in Ni foils was irradiated employing the J-25 Neutron Generator at the AERE, Savar, Dhaka. After irradiation, the counting was done by the activation technique using a high resolution Hp Ge gamma ray spectrometer. The gamma ray spectra was analyzed in a Canberra series-40 Multi-channel Analyzer. Calculations for cross sections were done at four different energies e.g., 13.870 MeV, 14.09 MeV, 14.483 MeV and 14.656 MeV. It was observed that the cross section data of the present work agrees well with JENDL-2 and other theoretical data. However, the ENDF/B-Vχ data is higher than the present values by about 11.60 to 14.27%. 1 fig., 17 refs., 2 tables (author)

  6. Measurements of the Fe-54 (n,p) Mn-54 Reaction Cross Section in the Neutron Energy Range 2.3-3.8 MeV

    International Nuclear Information System (INIS)

    We have measured the 54Fe (n, p) 54Mn reaction cross section using a surface barrier detector to record the number of protons released in the reaction. The neutron flux was determined by means of a hydrogenous radiator, detecting the scattered protons with the solid state detector, and calculating the number of impinging neutrons from the well known n-p scattering cross section. The 54Fe (n, p) 54Mn reaction cross section is found to increase from 25 mb at 2.3 MeV to 208 mb at 3.5 MeV

  7. Measure of elastic differential cross sections 3He (π±,π±) 3He and 4He (π±,π±) 4He in the 25 to 65 MeV range

    International Nuclear Information System (INIS)

    Measurement of low energy pion elastic differential cross sections on light nuclei 3He and 4He has been made to improve our understanding of pion-nucleus interaction mechanisms. For this purpose, π+ and π- cross sections at 25 and 51 MeV on 4He and 30, 45 and 65 MeV on 3He have been measured for scattering angles between 40 and 140 deg. in the laboratory. The pion flux was known within 2 pc accuracy and low temperature liquid targets were used. The scattered π+ and π- were detected in range spectrometers with 90 pc efficiency and 2 MeV energy resolution. Overall accuracy on the cross section is 5 pc. Comparison with microscopic optical potential calculations shows that much remains to be done to reproduced the measured cross sections. More particularly, Coulomb corrections, binding energy effects of the scattering nucleon and pion absorption should be more realistic to account properly for the data. (author)

  8. Production of plutonium tracers in Np-237 nuclear reactions with He-3-ions in the energy range from 26 to 60 MeV

    NARCIS (Netherlands)

    Aaltonen, J; Dendooven, P; Gromova, EA; Jakovlev, VA; Trzaska, WH

    1998-01-01

    Cross-sections for the reaction Np-237 + He-3 --> Pu-236,Pu-237,Pu-238 at He-3 bombarding energies from 26 to 60 MeV were measured. Thick-target yields, based on the measured and previously known cross-sections were constructed. The results are discussed and compared with Ether reactions leading to

  9. Vacancy-related defects in n-type Si implanted with a rarefied microbeam of accelerated heavy ions in the MeV range

    Science.gov (United States)

    Capan, I.; Pastuović, Ž.; Siegele, R.; Jaćimović, R.

    2016-04-01

    Deep level transient spectroscopy (DLTS) has been used to study vacancy-related defects formed in bulk n-type Czochralski-grown silicon after implantation of accelerated heavy ions: 6.5 MeV O, 10.5 MeV Si, 10.5 MeV Ge, and 11 MeV Er in the single ion regime with fluences from 109 cm-2 to 1010 cm-2 and a direct comparison made with defects formed in the same material irradiated with 0.7 MeV fast neutron fluences up to 1012 cm-2. A scanning ion microprobe was used as the ion implantation tool of n-Cz:Si samples prepared as Schottky diodes, while the ion beam induced current (IBIC) technique was utilized for direct ion counting. The single acceptor state of the divacancy V2(-/0) is the most prominent defect state observed in DLTS spectra of n-CZ:Si samples implanted by selected ions and the sample irradiated by neutrons. The complete suppression of the DLTS signal related to the double acceptor state of divacancy, V2(=/-) has been observed in all samples irradiated by ions and neutrons. Moreover, the DLTS peak associated with formation of the vacancy-oxygen complex VO in the neutron irradiated sample was also completely suppressed in DLTS spectra of samples implanted with the raster scanned ion microbeam. The reason for such behaviour is twofold, (i) the local depletion of the carrier concentration in the highly disordered regions, and (ii) the effect of the microprobe-assisted single ion implantation. The activation energy for electron emission for states assigned to the V2(-/0) defect formed in samples implanted by single ions follows the Meyer-Neldel rule. An increase of the activation energy is strongly correlated with increasing ion mass.

  10. Measurement of the cross-section of the process e+e- → π+π- at the CMD-2 detector in the 370-520 MeV energy range

    International Nuclear Information System (INIS)

    The cross sections of the process e+e- → π+π- have been measured in the c.m. energy range 370-520 MeV. The systematic error of measurements is 0.7%. The electromagnetic radius of pion is calculated in the vector dominant model by means of all CMD-2 detector data about pion form factor. The cross section of muon production is measured in the energy range of this experiment

  11. 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.

  12. Gamma ray production cross sections in proton induced reactions on natural Mg, Si and Fe targets over the proton energy range 30 up to 66 MeV

    CERN Document Server

    Yahia-Chérif, W; Kiener, J; Tatischeff, V; Lawrie, E; Lawrie, J J; Belhout, A; Benhabiles, H; Bucher, T D; Chafa, A; Damache, S; Debabi, M; Deloncle, I; Easton, J L; Hamadache, C; Hammache, F; Jones, P; Kheswa, B V; Khumalo, N; Lamula, T; Majola, S T H; Negi, D; Ndayishimye, J; Noncolela, S P; Moussa, D; Nchodu, R; Papka, P; de Sereville, N; Sharpey-Schafer, J F; Shirinda, O; Wiedeking, M; Wyngaardt, S

    2015-01-01

    Gamma-ray excitation functions have been measured for 30, 42, 54 and 66 MeV proton beams accelerated onto C + O (Mylar), Mg, Si, and Fe targets of astrophysical interest at the separate-sector cyclotron of iThemba LABS in Somerset West (Cape Town, South Africa). A large solid angle, high energy resolution detection system of the Eurogam type was used to record Gamma-ray energy spectra. Derived preliminary results of Gamma-ray line production cross sections for the Mg, Si and Fe target nuclei are reported and discussed. The current cross section data for known, intense Gamma-ray lines from these nuclei consistently extend to higher proton energies previous experimental data measured up to Ep ~ 25 MeV at the Orsay and Washington tandem accelerators. Data for new Gamma-ray lines observed for the first time in this work are also reported.

  13. Cross-section measurements for (n, 2n) reactions on stannum isotopes in the neutron energy range of 13.5 to 14.6 MeV

    Institute of Scientific and Technical Information of China (English)

    PU Zhong-Sheng; YAN Dong; MA Jun; DU Xiao-Fang; GUAN Qiu-Yun

    2008-01-01

    Cross-sections for (n, 2n) reactions have been measured on stannum isotopes at the neutron energies of 13.5 to 14.6 MeV using the activation technique. Data are reported for the following reactions:112Sn(n, 2n)111Sn, 118Sn(n, 2n)117Sn and 124Sn(n, 2n)123mSn. The neutron fluences were determined using the monitor reaction 93Nb(n, 2n)92mNb or 27Al(n, α)24Na. The results of present work were compared with data published previously.

  14. Effective atomic number and electron density of amino acids within the energy range of 0.122-1.330 MeV

    Science.gov (United States)

    More, Chaitali V.; Lokhande, Rajkumar M.; Pawar, Pravina P.

    2016-08-01

    Photon attenuation coefficient calculation methods have been widely used to accurately study the properties of amino acids such as n-acetyl-L-tryptophan, n-acetyl-L-tyrosine, D-tryptophan, n-acetyl-L-glutamic acid, D-phenylalanine, and D-threonine. In this study, mass attenuation coefficients (μm) of these amino acids for 0.122-, 0.356-, 0.511-, 0.662-, 0.884-, 1.170, 1.275-, 1.330-MeV photons are determined using the radio-nuclides Co57, Ba133, Cs137, Na22, Mn54, and Co60. NaI (Tl) scintillation detection system was used to detect gamma rays with a resolution of 8.2% at 0.662 MeV. The calculated attenuation coefficient values were then used to determine total atomic cross sections (σt), molar extinction coefficients (ε), electronic cross sections (σe), effective atomic numbers (Zeff), and effective electron densities (Neff) of the amino acids. Theoretical values were calculated based on the XCOM data. Theoretical and experimental values are found to be in a good agreement (error<5%). The variations of μm, σt, ε, σe, Zeff, and Neff with energy are shown graphically. The values of μm, σt, ε, σe are higher at lower energies, and they decrease sharply as energy increases; by contrast, Zeff and Neff were found to be almost constant.

  15. 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 65 MeV

    CERN Document Server

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

    2016-01-01

    Activation cross-sections data of longer-lived products of proton induced nuclear reactions on dysprosium were extended up to 65 MeV 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 36-65 MeV 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.

  16. 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.

  17. 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.)

  18. 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.

  19. 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.)

  20. McSUB, a Monte Carlo Library for neutron transport in two different media for the neutron energy range 0.1-20 MeV

    International Nuclear Information System (INIS)

    Library McSUB is a package of easy-to-use subroutines and functions treating neutron transport in two different kind of media by Monte Carlo calculations. The first medium, D0, contains deuterium and natural carbon while the second medium, D1, contains hydrogen and natural carbon. In the neutron energy interval 0.1-20 MeV eight different kinds of interactions are considered: Elastic and (n,2n) interactions with deuterium, elastic interactions with hydrogen and elastic and inelastic interactions with natural carbon. The inelastic interaction with carbon are subdivided into four different interaction classes, one for each excited state of the recoiled carbon nucleus. The neutron cross sections and Legendre coefficients (expressing differential cross sections) have been supplied by NEA Data Bank in France. (author)

  1. Elastic Neutron Scattering at 96 MeV

    Science.gov (United States)

    Hildebrand, A.; Blomgren, J.; Ataç, A.; Bergenwall, B.; Johansson, C.; Klug, J.; Mermod, P.; Nilsson, L.; Pomp, S.; Österlund, M.; Dangtip, s.; Tippawan, U.; Phansuke, P.; Jonsson, O.; Renberg, P.-U.; Prokofiev, A.; Nadel-Turonski, P.; Elmgren, K.; Olsson, N.; Blideanu, V.; Le Brun, C.; Lecolley, J.-F.; Lecolley, F.-R.; Louvel, M.; Marie-Noury, N.; Schweitzer, C.; Eudes, Ph.; Haddad, F.; Lebrun, C.; Koning, A. J.

    2005-05-01

    A facility for detection of scattered neutrons in the energy interval 50-130 MeV, SCANDAL (SCAttered Nucleon Detection AssembLy), has recently been installed at the 20 - 180-MeV neutron beam line of The Svedberg Laboratory, Uppsala. Elastic neutron scattering from 12C, 16O, 56Fe, 89Y, and 208Pb has been studied at 96 MeV in the 10 - 70° interval. The results from 12C and 208Pb have recently been published,6 while the data from 16O, 56Fe, and 89Y are under analysis. The achieved energy resolution, 3.7 MeV, is about an order of magnitude better than for any previous experiment above 65 MeV incident energy. The present experiment represents the highest neutron energy where the ground state has been resolved from the first excited state in neutron scattering. A novel method for normalization of the absolute scale of the cross section has been used. The estimated normalization uncertainty, 3%, is unprecedented for a neutron-induced differential cross section measurement on a nuclear target. The results are compared with modern optical model predictions, based on phenomenology or microscopic theory. Applications for these measurements are nuclear-waste incineration, single-event upsets in electronics, and fast-neutron therapy.

  2. 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)

  3. 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.

  4. Method for determination of the average parameters of the dispersion optical potential for p+A in the range of 40 ≤ A ≤ 208 and -60 ≤ E ≤ 65 MeV

    International Nuclear Information System (INIS)

    The method for determination of the average parameters of the proton dispersion optical potential, applicable in the area of the nuclei mass numbers 40 ≤ A ≤ 208 and within the energy range of -60 ≤ E ≤+65 MeV is proposed. Application of the average parameters makes it possible to reliable forecast the differential cross sections of elastic scattering and polarization, complete cross sections of reactions, characteristics of the single-particle proton stets in the A-1 and A+1 nuclei

  5. Study of the process $e^+ e^- \\to K\\overline{K}$ in the center-of-mass energy range 1004--1060 MeV with the CMD-3 detector at $e^+ e^-$ VEPP-2000 collider

    CERN Document Server

    Kozyrev, E A

    2016-01-01

    The $e^+ e^- \\to K^0_{S}K^0_{L}$ and $e^+ e^- \\to K^{-}K^{+}$ cross sections have been measured in the center-of-mass energy range 1004--1060 MeV for 25 energy points with about 2$\\div$3\\% systematic uncertainties. The analysis is based on 5.5 pb$^{-1}$ of integrated luminosity collected with the CMD-3 detector at the VEPP-2000 $e^+ e^-$ collider. The measured cross section is approximated according to Vector Meson Dominance model as a sum of $\\phi, \\omega, \\rho$-like amplitudes and their excitations, and $\\phi(1020)$ meson parameters have been obtained.

  6. 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.

  7. Study of the process $e^+ e^- \\to K^0_{S}K^0_{L}$ in the center-of-mass energy range 1004--1060 MeV with the CMD-3 detector at the VEPP-2000 $e^+ e^-$ collider

    CERN Document Server

    Kozyrev, E A

    2016-01-01

    The $e^+ e^- \\to K^0_{S}K^0_{L}$ cross section has been measured in the center-of-mass energy range 1004--1060 MeV at 25 energy points using $6.1 \\times 10^5$ events with $K^0_{S}\\to \\pi^+\\pi^-$ 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 $\\phi(1020)$ meson parameters the measured cross section is approximated according to the Vector Meson Dominance model as a sum of the $\\rho, \\omega, \\phi$-like amplitudes and their excitations. This is the most precise measurement of the $e^+ e^- \\to K^0_{S}K^0_{L}$ cross section with a 1.8\\% systematic uncertainty.

  8. 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.

  9. 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.

  10. 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.

  11. Cosmic-ray isotopic composition of C, N, O, Ne, Mg, Si nuclei in the energy range 50-200 MeV per nucleon measured by the Voyager spacecraft during the solar minimum period

    Science.gov (United States)

    Lukasiak, A.; Ferrando, P.; Mcdonald, F. B.; Webber, W. R.

    1994-01-01

    The isotopic composition of C, N, O, Ne, Mg, Si cosmic ray nuclei has been measured in the energy range 50-200 MeV per nucleon using data collected by the High-Energy Telescope of the cosmic-ray subsystem experiment on the Voyager 1 and 2 spacecraft. These data were collected during the period of minimum solar activity in 1986-1988 at an average distance of 27 AU with an effective solar modulation that was much less than at the Earth. The isotope analysis, based on the energy loss - total energy method, has a mass resolution of 0.2 amu for carbon and 0.4 amu at silicon. We find a (C-13)/(C-12) ratio slightly lower and a (O-18)/(O-16) ratio slightly enhanced over their solar system value. We also observe the previously reported enhancement of the (Ne-22)/(Ne-20) ratio relative to solar at the cosmic-ray source but only a weak, if any, enhancement of the (Mg-25)/(Mg-24), (Mg-26)/(Mg 24), and (Si-30)/(Si-28) ratios.

  12. Differential cross section measurements of 27Al(p,p/γ)27Al and 27Al(p,αγ)24Mg reactions in the energy range of 1.6-3.0 MeV

    Science.gov (United States)

    Jokar, A.; Kakuee, O.; Lamehi-Rachti, M.; Sharifzadeh, N.; Fathollahi, V.

    2015-11-01

    In this work measurement of differential cross sections of 27Al(p,p/γ)27Al (Eγ = 844, 1014 keV) and 27Al(p,αγ)24Mg (Eγ = 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/cm2 Al onto a 129 μg/cm2 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%.

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

    International Nuclear Information System (INIS)

    New data are presented for the 26Mg(p,n)26Al reaction at E/sub p/ = 19.12 and 24.97 MeV, for the 54Fe(p,n)54Co reaction at E/sub p/ = 17.20, 18.60, and 24.60 MeV, and for the 56Fe(p,n)56Co reaction at E/sub p/ = 19.12 and 24.59 MeV. Data were taken with the LLNL Cyclograaff at 16 angles from 3.50 to 159.00. A large detector at 23.80 with a long neutron flight path collected high resolution spectra. This large detector also collected separate 00 high resolution data on the 26Mg and 56Fe(p,n) reactions at E/sub p/ = 19 MeV. Absolute differential (p,n) cross sections were extracted for 1+ states in 26Al, 54Co, and 56Co, for the 0+ isobaric analong state (IAS) in 54Co and 56Co, for a 2+ state in each residual nucleus, and for the 0.199 MeV 7+ state of 54Co. No new experimental states were identified. Only relative cross sections were extracted at 00. 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+ states and to the 54Co and 56Co IAS. Normalization of the DWBA angle-integrated cross sections to measurements for the 54Co and 56Co 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 54Co and 56Co 1+ 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 26Al state at 9.44 MeV was found to be 0.69; B(GT)/sub exp/ of the T = 1 26Al state at 10.47 MeV was found to be 0.39

  14. 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)

  15. Elastic neutron scattering at 96 MeV from 12 C and 208 Pb

    Science.gov (United States)

    Klug, J.; Blomgren, J.; Ataç, A.; Bergenwall, B.; Hildebrand, A.; Johansson, C.; Mermod, P.; Nilsson, L.; Pomp, S.; Tippawan, U.; Elmgren, K.; Olsson, N.; Jonsson, O.; Prokofiev, A. V.; Renberg, P.-U.; Nadel-Turonski, P.; Dangtip, S.; Phansuke, P.; Österlund, M.; Le Brun, C.; Lecolley, J. F.; Lecolley, F. R.; Louvel, M.; Marie-Noury, N.; Schweitzer, C.; Eudes, Ph.; Haddad, F.; Lebrun, C.; Koning, A. J.; Ledoux, X.

    2003-12-01

    A facility for detection of scattered neutrons in the energy interval 50 130 MeV , SCANDAL, has recently been installed at the 20 180 MeV neutron beam line of the The Svedberg Laboratory, Uppsala. Elastic neutron scattering from 12 C and 208 Pb has been studied at 96 MeV in the 10° 70° interval. The achieved energy resolution, 3.7 MeV , is about an order of magnitude better than for any previous experiment above 65 MeV incident energy. The present experiment represents the highest neutron energy where the ground state has been resolved from the first excited state in neutron scattering. A novel method for normalization of the absolute scale of the cross section has been used. The estimated normalization uncertainty, 3% , is unprecedented for a neutron-induced differential cross section measurement on a nuclear target. The results are compared with modern optical model predictions based on phenomenology or microscopic nuclear theory.

  16. Elastic Neutron Scattering at 96 MeV from {sup 12}C and {sup 208}Pb

    Energy Technology Data Exchange (ETDEWEB)

    Klug, J.; Blomgren, J.; Atac, A. [and others

    2003-04-01

    A facility for detection of scattered neutrons in the energy interval 50-130 MeV, SCANDAL (SCAttered Nucleon Detection AssembLy), has recently been installed at the 20-180 MeV neutron beam line of the The Svedberg Laboratory, Uppsala. Elastic neutron scattering from {sup 12}C and {sup 208}Pb has been studied at 96 MeV in the 10-70 deg interval. The achieved energy resolution, 3.7 MeV, is about an order of magnitude better than for any previous experiment above 65 MeV incident energy. The present experiment represents the highest neutron energy where the ground state has been resolved from the first excited state in neutron scattering. A novel method for normalization of the absolute scale of the cross section has been used. The estimated uncertainty, 3 %, is unprecedented for a neutron-induced differential cross section measurement on a nuclear target. The results are compared with modern optical model predictions, based on phenomenology or microscopic nuclear theory.

  17. Elastic Neutron Scattering at 96 MeV from 12C and 208Pb

    International Nuclear Information System (INIS)

    A facility for detection of scattered neutrons in the energy interval 50-130 MeV, SCANDAL (SCAttered Nucleon Detection AssembLy), has recently been installed at the 20-180 MeV neutron beam line of the The Svedberg Laboratory, Uppsala. Elastic neutron scattering from 12C and 208Pb has been studied at 96 MeV in the 10-70 deg interval. The achieved energy resolution, 3.7 MeV, is about an order of magnitude better than for any previous experiment above 65 MeV incident energy. The present experiment represents the highest neutron energy where the ground state has been resolved from the first excited state in neutron scattering. A novel method for normalization of the absolute scale of the cross section has been used. The estimated uncertainty, 3 %, is unprecedented for a neutron-induced differential cross section measurement on a nuclear target. The results are compared with modern optical model predictions, based on phenomenology or microscopic nuclear theory

  18. The analyzing power Asub(y)(THETA) for 12C(n vector,nsub(0,1))12C in the neutron energy range from 6.8 to 17.3 MeV

    International Nuclear Information System (INIS)

    The analyzing power for the elastic and inelastic neutron scattering to the first excited state on 12C was measured at 21 energies from 6.8 to 17.3 MeV. The data from 8.9 to 14.9 MeV were together with very precise cross section data from the literature studied in the framework of the spherical optical model and the coupled channel formalism. The coupled channel analysis of the elastic and inelastic scattering on 12C in the framework of the rotator model yielded a good agreement between measured and calculated angular distributions. The determined quadrupole deformation parameter β2 = -0.67 agrees well with values from the literature. The existence of different qudrupole deformations for the central and spin-orbit components of the optical potential was studied. Large differences for the quadrupole deformations β2sup(c) and β2sup(so) were found at 8.9, 11.9, and 12.9 MeV. Especially at 8.9 MeV by this a great improvement of the fit to the data was reached. (orig./HSI)

  19. 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.

  20. 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

    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......, 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...

  1. Calculation of neutron cross sections for 90Zr, 208Pb and 209Bi in the energy range of 0.5-25 MeV by using the optical model potentials

    International Nuclear Information System (INIS)

    Neutron total cross sections and differential elastic scattering cross sections for the nuclides 90Zr, 208Pb and 209Bi were calculated using different global spherical optical potential (SOP) parameter sets at neutron energies from 0.5-25 MeV. Calculated cross sections for the corresponding nuclides were compared with their experimental data obtained by the EXFOR file to select the best fit parameter sets. It is found that the parameter sets of Ferer Rapaport for 90Zr and Bechetti and Greenless for 208Pb and 209Bi are the best fitted set to obtain the experimental data of total cross sections and angular distributions of these nuclides. (author)

  2. Review of neutron data: 10 to 40 MeV

    International Nuclear Information System (INIS)

    Neutron data are reviewed for incident neutron energies between 10 and 40 MeV. A census of the data shows that there are many gaps in this range and that the existing data are primarily for neutron energies around 14 MeV. Aside from total cross sections, there are few data between 10 and 13 MeV and between 15 and 40 MeV. Examples are presented to show the quality of selected data for total, elastic, inelastic, activation, and charged-particle and gamma-ray production cross sections. The spectra of emitted particles are also discussed

  3. 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.)

  4. Characterization of 2 MeV, 4 MeV, 6 MeV and 18 MeV buildup caps for use with a 0.6 cubic centimeter thimble ionization chamber

    Energy Technology Data Exchange (ETDEWEB)

    Salyer, R.L.; VanDenburg, J.W.; Prinja, A.K.; Kirby, T.; Busch, R. [Univ. of New Mexico, Albuquerque, NM (United States); Hong-Nian Jow [Sandia National Laboratories, Albuquerque, NM (United States)

    1996-07-01

    The purpose of this research is to characterize existing 2 MeV, 4 MeV and 6 MeV buildup caps, and to determine if a buildup cap can be made for the 0.6 cm{sup 3} thimble ionization chamber that will accurately measure exposures in a high-energy photon radiation field. Two different radiation transport codes were used to computationally characterize existing 2 MeV, 4 MeV, and 6 MeV buildup caps for a 0.6 cm{sup 3} active volume thimble ionization chamber: ITS, The Integrated TIGER Series of Coupled Electron-Photon Monte Carlo Transport Codes; and CEPXS/ONEDANT, A One-Dimensional Coupled Electron-Photon Discrete Ordinates Code Package. These codes were also used to determine the design characteristics of a buildup cap for use in the 18 MeV photon beam produced by the 14 TW pulsed power HERMES-III electron accelerator. The maximum range of the secondary electron, the depth at which maximum dose occurs, and the point where dose and collision kerma are equal have been determined to establish the validity of electronic equilibrium. The ionization chamber with the appropriate buildup cap was then subjected to a 4 MeV and a 6 MeV bremmstrahlung radiation spectrum to determine the detector response.

  5. 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...

  6. Excitation functions of proton-induced reactions on natural Nd in the 10-30 MeV energy range, and production of radionuclides relevant for double-{\\beta} decay

    CERN Document Server

    Lebeda, O; Schrock, P; Štursa, J; Zuber, K; 10.1103/PhysRevC.85.014602

    2012-01-01

    A preferred candidate for neutrinoless double-{\\beta} 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-{\\beta}-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 \\v{R...

  7. Atomic inner shell ionization: a new method of nuclear interaction lifetimes in the range 10-16-10-18 second. Lifetime measurement of the compound nucleus in the reaction 106Cd+p (Ep=10 and 12 MeV)

    International Nuclear Information System (INIS)

    A new method to measure the lifetime of the compound nucleus formed in the reaction 106Cd+p at Ep=10 and 12 MeV is described. The nuclear lifetime is compared to the known lifetime of an atomic inner shell vacancy created in the entrance channel of the nuclear reaction. If the ionization probability in he way-in of the nuclear reaction is kown the compound nucleus lifetime is deduced by a simple relation from the number of compound X-rays measured in coincidence with one of the reaction products. A large number of ionization probability values measured in very small impact parameter collisions induced by H+, He+, D+ on Al, Cu, S, Ti, Si, Ag, Cd are reported. The data are interpreted in terms of the corrected SCA theory of ionization. New effects such as angular dependence and trajectory effect (hair-pin-curve effect) are shown experimentally. The influence of a nuclear delay time on the ionization probability value is considered; the effect on a nuclear reaction of the energy losses by the projectile during the ionization process is analysed in detail. The yield curve of the resonant nuclear reaction 27Al(p,γ)28Si is taken as an example. A detailed analysis of the compound nucleus 107In lifetimes is given. Attention has been paid to competitive processes leading to X ray emission of same energy as the compound X rays. Extensions of the method to measure compound nucleus lifetimes in collision induced by heavy ions and to separate the shape elastic and compound elastic mechanisms are presented

  8. 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.

  9. Cross sections of electron loss and capture for beams of O{sup +} in water vapor from the energy range of 0,2 to 1,2 MeV; Secoes de choque de perda e captura eletronica para feixes de O{sup +} em vapor de agua em uma faixa de energia entre 0,2 e 1,2 MeV

    Energy Technology Data Exchange (ETDEWEB)

    Oliveira, Vitor Jesus de

    2015-06-01

    The study of the interactions between atoms and molecules is important for the knowledge of the cross sections of the processes that contribute to the deposition of energy by charged particle beams used in radiotherapy planning and transport particle simulation codes. Heavy ions, such as oxygen, induce many cellular and molecular damages in human cells.as a result of interaction between the projectile and atoms and molecules. The use of proton and carbon as the projectile interacting with water molecules is well characterized, however there are few studies with oxygen ions. In this work we are interested in the study of electron loss (projectile ionization) and electron capture with charge state 1+. The Pelletron accelerator of 1.7 MeV from the Federal University of Rio de Janeiro housed in the Atomic and Molecular collisions Laboratory (LACAM) has been used, which can accelerate atomic and molecular ions up to speeds of the order of hundredths of light speed, and consists of the source of negative ions, the Wien filter, the accelerator itself and the magnet load selector. The detection device used to evaluate the processes of interaction (capture and loss) between the beam of the O{sup +} and the water molecule is a Microchannel Plate (MCP) at the position sensitive anode. The collisions of O{sup +} beans are being studied in the range of 0.2 to 1.2 MeV with water vapor (Z = 10). Were obtained the respective absolute cross sections for electron loss and electron capture and compared with the cross sections of the molecule methane (CH4 → Z = 10), the isoelectronic water molecule. The experimental results show an agreement between the measurements with water and methane. Comparisons were made with results of theoretical models for electron loss using the 'Free Collision Model' and for capture the Bohr and Lindhard model. The theoretical results for electron loss show an agreement of experimental data with the model used. The model of Bohr and Lindhard

  10. Measurements of the 24Mg(d,p0,1,2,3,4) and natMg(d,d0) reactions cross sections in the energy range of 1.2-2 MeV for NRA and EBS applications

    Science.gov (United States)

    Rafi-kheiri, H.; Kakuee, O.; Lamehi-Rachti, M.

    2016-04-01

    Differential cross sections of the 24Mg(d,p0,1,2,3,4) reactions were obtained in the range Ed,lab = 1.2-2 MeV and at the scattering angles of 90°, 135°, 150° and 165° using a thin Mg target having thickness of 76.7 ± 3.1 μg/cm2. The cross section values were determined with an average energy step of ∼25 keV while the detailed measurements were carried out with an energy step of ∼5 keV around the resonance peaks. Elastic scattering data for three steep backward angles (135°, 150° and 165°) were also studied for the same incident deuteron energy range and steps. The results were compared with those of the previous studies. Moreover, the validity of the measured data has been benchmarked using a thick Mg target at two deuteron beam energies of 1.7 and 2 MeV.

  11. Electret dosemeter response to electrons with energy of 3 Mev, 7 Mev, 11 Mev

    International Nuclear Information System (INIS)

    The preliminary results obtained when electret ionization chambers are irradiated with electron of 3, 7, 11 Mev, from 12 mevatron accelerators using a external cop of polyethylene and nylon are presented. (C.G.C.)

  12. Observation of complete- and incomplete-fusion components in {sup 159}Tb,{sup 169}Tm({sup 16}O,x) reactions: Measurement and analysis of forward recoil ranges at E/A{approx}5-6 MeV

    Energy Technology Data Exchange (ETDEWEB)

    Singh, Pushpendra P.; Kumar Sharma, Manoj; Unnati; Singh, Devendra P.; Singh, B.P.; Prasad, R. [A. M. University, Accelerator Laboratory, Department of Physics, Aligarh (India); Kumar, Rakesh; Golda, K.S. [Inter-University Accelerator Center, NP Group, P. O. Box No. 10502, New Delhi (India)

    2007-10-15

    With a view to study complete- and incomplete-fusion components in {sup 159}Tb,{sup 169}Tm({sup 16}O,x) reactions, experiments have been carried out at the Inter-University Accelerator Center, New Delhi, India using the 15UD Pelletron accelerator facilities. The forward mean recoil ranges for some radio-nuclides: {sup 168m}Lu, {sup 167}Lu, {sup 167}Yb, {sup 166}Tm produced in the {sup 16}O+{sup 159}Tb system at {approx}90 MeV, and {sup 179}Re, {sup 177}Re, {sup 177}W, {sup 178}Ta and {sup 177}Hf produced in the {sup 16}O+{sup 169}Tm system at {approx}87 MeV have been measured. The recoil-catcher activation technique followed by off-line {gamma}-spectrometry has been employed in the present work. The analysis of forward mean ranges for different radio-nuclides has been done in the framework of the degree of linear momentum transfer from projectile to target nucleus by adopting break-up fusion model considerations. Different complete- and incomplete-fusion components, which may be attributed to the fusion of {sup 16}O and/or {sup 12}C and {sup 8}Be transfer from the {sup 16}O projectile to the target nucleus have been observed. An attempt has also been made to separate out the relative percentage contributions of complete- and incomplete-fusion components using experimentally measured forward recoil ranges. The complete-fusion contributions deduced from recoil range distribution are found to be consistent with the prediction of the theoretical model code PACE. The analysis of data indicates the complete- and incomplete-fusion competition for both the systems at the given energies. (orig.)

  13. 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.)

  14. Production of no-carrier-added {sup 135}La at an 18 MeV cyclotron and its purification for investigations at a concentration range down to 10{sup -15} mol/L

    Energy Technology Data Exchange (ETDEWEB)

    Mansel, Alexander; Franke, Karsten [Helmholtz-Zentrum Dresden-Rossendorf, Leipzig (Germany). Reactive Transport Div.

    2015-07-01

    The production of non-commercially available {sup 135}La by proton irradiation of an isotopically enriched [{sup 135}Ba]BaCO{sub 3} target at a cyclotron is described. The purification of the radionuclide was performed by a La-selective resin. {sup 135}La was separated in no-carrier-added (n.c.a) form in a nitric acid solution with a radiochemical yield of 83 ± 5% and a total activity per batch of 43 ± 3 MBq. The enriched [{sup 135}Ba]Ba was recycled to the carbonate form with a recovery of 90 ± 3%. On the basis of a detection limit of 1 Bq/mL, solutions of n.c.a. {sup 135}La could be measured down to the 10{sup -15} mol/L concentration range.

  15. 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....

  16. 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)

  17. Consistent analysis of proton elastic scattering from sup 4 sup , sup 6 sup , sup 8 He and sup 6 sup , sup 7 sup , sup 9 sup , sup 1 sup 1 Li in the energy range of 25-75 A MeV

    CERN Document Server

    Gupta, D; Kanungo, R

    2000-01-01

    While sup 1 sup 1 Li is known to be a halo nucleus with two neutrons around a sup 9 Li core, the neutrons in sup 6 He are predicted to form a skin around its sup 4 He core. Both nuclei have very low breakup thresholds. To understand the structure and reaction dynamics of these nuclei, a consistent analysis of the available low energy (25-75 A MeV) proton elastic scattering data on sup 4 sup , sup 6 sup , sup 8 He and sup 6 sup , sup 7 sup , sup 9 sup , sup 1 sup 1 Li nuclei is carried out in a folding model framework. A finite-range, momentum, density and isospin dependent NN interaction (SBM) is folded with realistic densities of different nuclei. To fit the elastic angular distribution, the real part of the folded potentials are multiplied by a renormalization factor ( N sub R ). Except for the p+ sup 4 He scattering at low incident energy, the N sub R values are found to be significantly different from 1.0, indicating appreciable channel coupling effects in the energy region considered. Variation of N sub ...

  18. Crab Nebula observations - 0.2-10 MeV

    Science.gov (United States)

    Gruber, D. E.

    1975-01-01

    Observations of the total emission from the Crab Nebula and also of the pulsed component were made over the 0.2 to 10-MeV range during three balloon flights in 1971 with an actively-collimated NaI scintillator. The total emission flux was positively observed over the entire interval. The observed spectrum to 1 MeV agrees with an extrapolation of the E to the -2.2 power law, which fits lower-energy data. The observations above 1 MeV are factors of 3 and 20 above this law and are better fit with a spectral index of 0.8. Confidence levels are 3 sigma or better for each half-decade band. The three observations are consistent with a constant flux level. The NP 0532 flux, detected during one flight only (August 8) between 0.2 and 0.38 MeV, agrees with the exponential power law spectrum already determined from other observations. The possibility of a rapidly rising pulsed emission fraction over the 0.1- to 1-MeV interval is excluded by this observation.

  19. AVERAGE REACTION CROSS-SECTIONS FOR 74-MEV TO 112-MEV ALPHA-PARTICLES ON I-127 AND CS-133

    NARCIS (Netherlands)

    WARNER, RE; WILSCHUT, HW; RULLA, WF; FELDER, GN

    1991-01-01

    The average reaction cross section for 74- to 112-MeV alpha particles on I-127 and Cs-133 was measured by a new method using a magnetic spectrograph and a CsI scintillation detector. The result, sigma-R = 2220+/-50 mb, is in good agreement with optical model calculations and finite-range microscopic

  20. Elastic and inelastic scattering of 30 MeV and 180 MeV antiprotons on nuclei

    International Nuclear Information System (INIS)

    This thesis reports on the first measurements of angular distributions for elastic and inelastic scattering of antiprotons from nuclei, which have been performed, using the beam delivered by LEAR and the spectrometer SPES II, over a wide angular range and with good precision. Angular distributions for elastic scattering of 50 MeV antiprotons from 12C, 40Ca, 208Pb and 180 MeV antiprotons from 12C, 16O, 18O, 40Ca, 208Pb have been measured. Data on the inelastic 4.4 MeV and 9.6 MeV excited states of 12C and 1.98 MeV excited state of 18O have also been collected. The diffractive angular distributions are first analysed in terms of a fuzzy black disk model, which confirms that the antiproton is strongly absorbed (annihilation) by the nuclei. Optical model analysis, with Woods-Saxon geometry, shows that the real potential is attractive and shallow. The potentials are only determined at the nuclear surface, around the strong absorption radius, where /W(R)/ > 2 /V(R)/. Main characteristics of the antip-nucleus elastic scattering cross sections are well described within microscopic models using the free elementary antiN N interaction, like KMT which have no free parameters. Possibility for test of spin-isospin dependence of the elementary amplitude antiN-N from the measurement of unnatural parity states is also studied

  1. THE ZR-90(N, P)Y-90 REACTION AT E(N) = 98 MEV

    NARCIS (Netherlands)

    CONDE, H; OLSSON, N; RAMSTROM, E; RONNQVIST, T; ZORRO, R; BLOMGREN, J; HAKANSSON, A; TIBELL, G; JONSSON, O; NILSSON, L; RENBERG, PU; OSTERLUND, M; UNKELBACH, W; WAMBACH, J; VANDERWERF, SY; ULLMANN, J; WENDER, SA

    1992-01-01

    Double-differential cross sections of the Zr-90(n, p) reaction have been measured at 98 MeV in the angular range 0-degrees-30-degrees for excitation energies up to 40 MeV. The spectra have been interpreted in terms of direct and multistep reactions. The contributions from the latter have been calcul

  2. Valine radiolysis by MeV ions

    Science.gov (United States)

    Da Silveira, Enio

    2016-07-01

    Valine, (CH3)2 CHCH (NH2) COOH, is a protein amino acid that has been identified in extraterrestrial environments and in the Murchison meteorite [1]. The knowledge of half-lives of small organic molecules under ionizing radiation is important for the setup of models describing the spread out of prebiotics across the Solar System or the Galaxy. We have investigated typical effects of MeV cosmic ray ions on prebiotic molecules in laboratory by impinging ions produced by the PUC-Rio Van de Graaff accelerator. Pure valine films, deposited by evaporation on KBr substrates, were irradiated by H ^{+}, He ^{+} and N ^{+} ion beams, from 0.5 to 1.5 MeV and up to a fluence of 10 ^{15} projectiles/cm ^{2}. The sample temperature was varied from 10 K to 300 K. The irradiation was interrupted several times for Mid-FTIR analysis of the sample. The main findings are: 1- The column density of the valine decreases exponentially with fluence. 2- In some cases, a second exponential appears in the beginning of irradiation; this feature has been attributed to sample compaction by the ion beam [2]. 3- Destruction cross sections of valine are in the 10 ^{-15} cm ^{2} range, while compaction cross sections are in the 10 ^{-14} cm ^{2} range. 4- Destruction cross section increases with the stopping power of the beam and also with the sample temperature. 5- Surprisingly, during the radiolysis of valine, just CO _{2} is seen by as a daughter molecule formed in the bulk. 6- After long beam fluence, also a CO peak appears in the infrared spectrum; this species is however interpreted as a fragment of the formed CO2 molecules. 7- Considering the flux ratio between laboratory experiments and actual galactic cosmic rays, half-life of valine is predicted for ISM conditions [3]. This work on pure valine is the first measurement of a series. New experiments are planned for determining cross sections of valine dissolved in H _{2}O or CO _{2}, inspired by the study performed for glycine [4]. [1] P

  3. Re-measurement of the neutron-induced gamma-ray production cross sections for iron in the energy range 850 keV less than or equal to E/sub n/ less than or equal to 20. 0 MeV. [Tables

    Energy Technology Data Exchange (ETDEWEB)

    Chapman, G.T.; Morgan, G.L.; Perey, F.G.

    1976-07-01

    Values of the gamma-ray production cross sections for neutron interactions with iron as reported by previous investigators have differed by as much as a factor of 1.5 or more at neutron energies greater than about 5 MeV. Because of this discrepancy, the measurements were repeated at ORNL using the ORELA as a pulsed source of neutrons with energies between 850 keV and 20 MeV. The data were obtained using a NaI(Tl) gamma-ray spectrometer oriented at an angle of 125/sup 0/ to the incident neutron beam. The sample was positioned in the beam at a distance of 47.35 meters from the neutron source. The resulting data, presented as differential cross sections (d/sup 2/sigma/d..cap omega..dE) for gamma rays between 0.7 and 10.5 MeV, show good agreement with some previously published data, but are significantly different from previous ORNL measurements for neutron energies greater than 5 MeV.

  4. The Karlsruhe Neutron Transmission Experiment (KANT): Spherical shell transmission measurements with 14 MeV neutrons on beryllium

    International Nuclear Information System (INIS)

    This is a set of viewgraphs (no additional text) of a presentation on spherical shell transmission measurements with 14 MeV neutrons on beryllium; the cross for 9Be(n,2n)2α for the energy range between threshold (1.85 MeV) and 20 MeV neutron energy is measured and the measurement is compared with the literature. Also, neutron leakage multiplication in spherical Be shells with various thicknesses are presented. Figs, tabs

  5. XRD study of yttria stabilized zirconia irradiated with 7.3 MeV Fe, 10 MeV I, 16 MeV Au, 200 MeV Xe and 2.2 GeV Au ions

    Science.gov (United States)

    Nakano, K.; Yoshizaki, H.; Saitoh, Y.; Ishikawa, N.; Iwase, A.

    2016-03-01

    To simulate energetic neutron irradiation effects, yttria-stabilized zirconia (YSZ) which is one of the major materials for electrical corrosion potential sensors (ECP sensors) was irradiated with heavy ions at energies ranging from 7.3 MeV to 2.2 GeV. Ion irradiation effects on the lattice structure were analyzed using the X-ray diffraction (XRD). The increase in lattice constant was induced by the ion irradiation. It was dominated by the elastic collision process and not by the electronic excitation process. The lattice disordering which was observed as a broadening of XRD peaks was also induced by the irradiation especially for 200 MeV Xe ion irradiation. The present result suggests that the expansion and/or the disordering of YSZ lattice induced by energetic neutrons may affect the durability of a joint interface between a metal housing and YSZ membrane for the usage of ECP sensors in nuclear power reactors.

  6. Two body photodisintegration of the deuteron from 100 to 800 MeV

    Energy Technology Data Exchange (ETDEWEB)

    Crawford, R.; Annand, J.R.M.; Anthony, I. [Glasgow Univ. (United Kingdom). Dept. of Physics and Astronomy; Ahrens, J.; Beck, R. [Mainz Univ. (Germany). Inst. fuer Kernphysik; Braghieri, A.; Pedroni, P. [Istituto Nazionale di Fisica Nucleare, Pavia (Italy); Altieri, S. [Istituto Nazionale di Fisica Nucleare, Pavia (Italy)]|[Pavia Univ. (Italy). Ist. di Fisica Nucleare; Audit, G.; D`Hose, N. [CEA Centre d`Etudes de Saclay, 91 - Gif-sur-Yvette (France). Dept. d`Astrophysique, de la Physique des Particules, de la Physique Nucleaire et de l`Instrumentation Associee] [and others

    1996-01-01

    The total and the differential cross sections for the D({gamma},p)n reaction have been measured over the photon energy range 100-800 MeV at the 855 MeV MAMI Microtron in Mainz. The data are presented in the form of thirty-five angular distributions at c.m. proton angles between 30 deg-160 deg in 10 deg intervals and at photon energies in steps of 20 MeV. Previous experimental work is reassessed in the light of the present results and the results compared with some recent theoretical calculations. (author). Submitted to Nuclear Physics, B (NL); 23 refs.

  7. The Pb-208(n,p)Tl-208 reaction at E-n=97 MeV

    NARCIS (Netherlands)

    Ringbom, A; Hakansson, A; Tibell, G; Zorro, R; Blomgren, J; Conde, H; Rahm, J; Olsson, N; Ramstrom, E; Ronnqvist, T; Jonsson, O; Nilsson, L; Renberg, PU; vanderWerf, SY; Lenske, H

    1997-01-01

    Double-differential cross sections of the Pb-208(n,p) reaction have been measured at 97 MeV in the angular range 0 degrees-30 degrees for excitation energies up to 40 MeV. The experimental proton spectra have been compared with calculated spectra obtained with a statistical multistep direct reaction

  8. Observations of gamma radiation between 0.4 MeV and 7 MeV at balloon altitudes using a Compton telescope

    Science.gov (United States)

    Lockwood, J. A.; Webber, W. R.; Friling, L. A.; Macri, J.; Hsieh, L.

    1981-01-01

    Balloon-borne measurements of the atmospheric and diffuse gamma-ray flux in the energy range 0.4-7.0 MeV with a Compton telescope, which included pulse-shape discrimination of the first scattering detector and a time-of-flight system between the first and second detector elements, are reported. Comparison of the diffuse cosmic gamma-ray flux to the atmospheric gamma rays indicates that 0.2-5.0 MeV is the optimum energy range for measurements made at the top of the earth's atmosphere. The measured total atmospheric gamma-ray flux between zero and 40 deg has an energy spectrum that agrees with the calculations of Ling (1975). Observations indicate that the ratio of the diffuse to atmospheric gamma ray fluxes at 3.5 g/sq cm is a maximum, about 1.0, between 0.7 and 3.0 MeV.

  9. <600> MeV synchro-cyclotron

    CERN Multimedia

    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.

  10. Determination of Neutron Spectrum by the Dosimetry Foil Method up to 37 Mev

    Science.gov (United States)

    Simakov, S. P.; Bém, P.; Burjan, V.; Fischer, U.; Forrest, R. A.; Götz, M.; Honusek, M.; Kroha, V.; Novàk, J.; Šimečková, E.

    2009-08-01

    The dosimetry activation foil technique was used for the determination of a white neutron spectrum at the U120M cyclotron facility of NPI/Řež. The neutrons were produced by 37 MeV protons slowing down in the thick heavy water target and have an energy distribution extending up to 37 MeV. To cover the whole energy range a set of 10 foils Al, Ti, Fe, Co, Ni, Y, Nb, In, Lu, and Au was used. The γ-rays from the decaying nuclei produced in 26 activation reactions were detected. The cross sections for these reaction were chosen from European Activation File EAF-2007 (up to 55 MeV) after intercomparison with the dosimetry cross section library IRDF-2002 which represents the cross section only up to 20 MeV and other high energy libraries. For the spectrum determination the SAND-II code was used after it had been modified to input dosimetry cross sections above 20 MeV in an arbitrary group structure. The guessed neutron spectrum which is needed to start an adjustment procedure was combined from those measured and calculated by the MCNPX code. The uncertainty of the adjusted neutron spectrum was estimated using the uncertainties of measured specific γ-activities induced in nuclides and dosimetry cross sections. It is less than 10% in the energy range below 25 MeV, the sensitivity domain of the most dosimetry reactions, but increases above this energy.

  11. Characteristic parameters of 6--21 MeV electron beams from a 21 MeV linear accelerator

    Energy Technology Data Exchange (ETDEWEB)

    Al-Ghazi, M.S.A.L. (Department of Medical Physics, Thunder Bay Regional Cancer Centre, Ontario Cancer Treatment and Research Foundation, Thunder Bay, Ontario P7A 7T1, (Canada) Department of Physics, Lakehead University, Thunder Bay, Ontario P7B 5E1, (Canada) Lingman, D. Department of Medical Physics, Thunder Bay Regional Cancer Centre, Ontario Cancer Treatment and Research Foundation, Thunder Bay, Ontario P7A 7T1, (Canada) Department of Computer Science, Lakehead University, Thunder Bay, Ontario P7B 5E1, (Canada)); Gilbert, L.D. (Thekkumthala, J. Department of Medical Physics, Thunder Bay Regional Cancer Centre, Ontario Cancer Treatment and Research Foundation, Thunder Bay, Ontario P7A 7T1, (Canada))

    1991-07-01

    Dosimetry measurements have been carried out for the electron beams produced by a linear accelerator at energies 6, 8, 10, 14, 18, and 21 MeV. Characteristic parameters of the central axis dose distributions were derived and compared to corresponding values of electron beams from other accelerators in clinical use where such a comparison is appropriate. A comprehensive set of dosimetric parameters is provided for electron beam treatment planning. The data include central axis depth dose, range--energy parameters, beam penumbra and uniformity.

  12. 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.

  13. 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)

  14. Calorimetry for absorbed dose measurement at 1-4 MeV electron accelerators

    International Nuclear Information System (INIS)

    Calorimeters are used for dose measurement, calibration and intercomparisons at industrial electron accelerators, and their use at 10 MeV electron accelerators is well documented. The work under this research agreement concerns development of calorimeters for use at electron accelerators with energies in the range of 2-4 MeV. The dose range of the calorimeters is 3-40 kGy, and their temperature stability after irradiation was found to be sufficient for practical use in an industrial environment. Measurement uncertainties were determined to be 5% at k = 2. (author)

  15. Response of AGATA Segmented HPGe Detectors to Gamma Rays up to 15.1 MeV

    CERN Document Server

    Crespi, F C L; Camera, F; Akkoyun, S; Atac, A; Bazzacco, D; Bellato, M; Benzoni, G; Blasi, N; Bortolato, D; Bottoni, S; Bracco, A; Brambilla, S; Bruyneel, B; Cerutia, S; Ciemala, M; Coelli, S; Eberth, J; Fanin, C; Farnea, E; Gadea, A; Giaz, A; Gottardo, A; Hess, H; Kmiecik, M; Leoni, S; Maj, A; Mengoni, D; Michelagnoli, C; Million, B; Montanari, D; Pellegri, L; Recchia, F; Reiter, P; Riboldi, S; Ur, C A; Vandone, V; Valiente-Dobon, J J; Wieland, O; Wiens, A

    2012-01-01

    The response of AGATA segmented HPGe detectors to gamma rays in the energy range 2-15 MeV was measured. The 15.1 MeV gamma rays were produced using the reaction d(11B,ng)12C at Ebeam = 19.1 MeV, while gamma-rays between 2 to 9 MeV were produced using an Am-Be-Fe radioactive source. The energy resolution and linearity were studied and the energy-to-pulse-height conversion resulted to be linear within 0.05%. Experimental interaction multiplicity distributions are discussed and compared with the results of Geant4 simulations. It is shown that the application of gamma-ray tracking allows a suppression of background radiation following neutron capture by Ge nuclei. Finally the Doppler correction for the 15.1 MeV gamma line, performed using the position information extracted with Pulse-shape Analysis, is discussed.

  16. DC Electron Accelerators - a perspective on 3 MeV DC accelerator at EBC

    International Nuclear Information System (INIS)

    Electron beam accelerators are finding wide ranging applications like surface curing of coatings, cross-linking polymeric materials, sterilization of medical products, coloration of diamonds, disinfection and preservation of food products, purification of industrial and biological waste etc. Electron beam energy and dose rate for different application differs widely depending upon the type of product and the desired modification. The beam energy and dose rate requirement for these types of applications ranges between 0.15 MeV to 10 MeV and few kilowatt to hundreds of kilowatts. Electrostatic accelerators (direct current type) are suitable option for large throughput, high electrical efficiency for the above applications. In view of the growing needs we have taken up indigenous development of industrial accelerators at APPD, BARC. A machine rated for 3 MeV, 30 kW beam power is in the trial operations at Electron Beam Centre, Kharghar, Navi Mumbai. The 3 MV DC supply for this based on a parallel fed voltage multiplier scheme considering power efficiency, energy stability and reliability. The accelerator is designed to operate with beam energies from 1 MeV to 3 MeV with beam current of 0-10 mA

  17. Shielding measurements for a 230 MeV proton beam

    International Nuclear Information System (INIS)

    Energetic secondary neutrons produced as protons interact with accelerator components and patients dominate the radiation shielding environment for proton radiotherapy facilities. Due to the scarcity of data describing neutron production, attenuation, absorbed dose, and dose equivalent values, these parameters were measured for 230 MeV proton bombardment of stopping length Al, Fe, and Pb targets at emission angles of 0 degree, 22 degree, 45 degree, and 90 degree in a thick concrete shield. Low pressure tissue-equivalent proportional counters with volumes ranging from 1 cm3 to 1000 cm3 were used to obtain microdosimetric spectra from which absorbed dose and radiation quality are deduced. Does equivalent values and attenuation lengths determined at depth in the shield were found to vary sharply with angle, but were found to be independent of target material. Neutron dose and radiation length values are compared with Monte Carlo neutron transport calculations performed using the Los Alamos High Energy Transport Code (LAHET). Calculations used 230 MeV protons incident upon an Fe target in a shielding geometry similar to that used in the experiment. LAHET calculations overestimated measured attenuation values at 0 degree, 22 degree, and 45 degree, yet correctly predicted the attenuation length at 90 degree. Comparison of the mean radiation quality estimated with the Monte Carlo calculations with measurements suggest that neutron quality factors should be increased by a factor of 1.4. These results are useful for the shielding design of new facilities as well as for testing neutron production and transport calculations

  18. 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)

  19. Study of {sup 27}Al(n,x{gamma}) reactions up to a neutron energy of 400 MeV

    Energy Technology Data Exchange (ETDEWEB)

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

    1994-06-01

    The prompt {gamma}-radiation from the interaction of fast neutrons with Al was measured using the white neutron beam of the WNR facility at the Los Alamos National Laboratory. Partial production cross sections for residual nuclei in the range from F to Al were measured from threshold up to 400 MeV by observing the most intense {gamma}-transitions between low lying levels of these nuclei. Two-dimensional neutron time-of-flight versus gamma pulse height spectra from the interaction of the neutrons with Al were observed after flight-paths of about 20 and 40 m with a high-purity Ge-detector. The neutron cross sections for prominent {gamma}-transitions in a large number of residual nuclei could be derived with typical uncertainties of 10--20% up to a neutron energy of 400 MeV. The energy resolution varies from {approx}0.2 MeV at 10 MeV to {approx}50 MeV at 400 MeV. In the low energy range (up to 60 MeV) the results are compared with nuclear model calculations using the code GNASH. A very good overall agreement is obtained without special adjustment of parameters.

  20. Fabrication of the PEFP 3MeV RFQ Upgrade

    CERN Document Server

    Kwon, Hyeok-Jung; Jang, Ji-Ho; Kim, Han-Sung; Kim, Yong-Hwan

    2005-01-01

    A 100MeV proton accelerator has been developed at PEFP (Proton Engineering Frontier Project) as a 21C Frontier Project. The goal of the first stage of the project is to develop a 20MeV accelerator. The 20MeV accelerator consists of ion source, LEBT, 3MeV RFQ and 20MeV DTL. The 3MeV RFQ was already installed and being tested. During preliminary test, some problems, such as the resonant frequency and field profile tuning, sharp edge in the vane end, inadequate RF seals have been found out. Therefore, it was decided to fabricate another RFQ. The RFQ upgrade includes some characteristics such as constant voltage profile, adoption of transition cell which are different from present one. In this paper, the fabrication of the PEFP 3MeV RFQ upgrade are presented.

  1. Neutron scattering and reactions on 59Co from 1 to 20 MeV

    International Nuclear Information System (INIS)

    The paper presents a complete analysis of all the interactions of neutrons with 59Co in the energy range 1-20 meV, excluding the resonance region at very low energies. Optical model calculations, compound nucleus calculations and Weisskopf-Ewing calculations are given. (U.K.)

  2. A study of proton-induced reactions at 190 MeV

    NARCIS (Netherlands)

    Mukherjee, B.; Bacelar, J.C.S; Beijers, J.P.M.; Harakeh, M.N.; Kalantar-Nayestanaki, N.; Kis, M.; Löhner, H.; Mahjour Shafiei, M.

    2004-01-01

    Differential cross-sections and proton multiplicities, resulting from the bombardment of Fe-56, Pb-208, and U-238 targets by a 190 MeV proton beam were measured for the first time. Data were taken over two different angular ranges 5degrees-30degrees and 91degrees-160degrees with two different detect

  3. Experimental bremsstrahlung yields for MeV proton bombardment of beryllium and carbon

    Energy Technology Data Exchange (ETDEWEB)

    Cohen, David D. [Institute for Environmental Research, Australian Nuclear Science and Technology Organisation, Private Mail Bag 1, Menai, NSW 2234 (Australia)], E-mail: dcz@ansto.gov.au; Stelcer, Eduard; Siegele, Rainer; Ionescu, Mihail; Prior, Michael [Institute for Environmental Research, Australian Nuclear Science and Technology Organisation, Private Mail Bag 1, Menai, NSW 2234 (Australia)

    2008-04-15

    Experimental bremsstrahlung yields for 2, 3 and 4 MeV protons on thin beryllium and carbon targets have been measured. The yields have been corrected for detector efficiency, self-absorption in the target and fitted to 9th order polynomials over the X-ray energy range 1-10 keV for easy comparison with theoretical calculations.

  4. Energy dissipation of 0.6 and 0.8MeV electrons in elemental materials

    International Nuclear Information System (INIS)

    The spatial distributions of energy dissipation of electrons in Be, Al, Cu and Ag were obtained experimentally for well collimated electron beams of 0.6 and 0.8 MeV. Experimental results of the present work join smoothly to the previous ones of 1.0 MeV to 2.0 MeV electrons. Comparing with Spencer theory, it is found that our experiment and theory are generally in agreement except in shallow penetration depth. The extrapolated range values of the present work join also smoothly in the atomic number curves of previous ones. (author)

  5. ETAII 6 MEV PEPPERPOT EMITTANCE MEASUREMENT

    Energy Technology Data Exchange (ETDEWEB)

    Paul, A C; Richardson, R; Weir, J

    2004-10-18

    We measured the beam emittance at the ETAII accelerator using a pepper-pot diagnostic at nominal parameters of 6 MeV and 2000 Amperes. During the coarse of these experiments, a ''new tune'' was introduced which significantly improved the beam quality. The source of a background pedestal was investigated and eliminated. The measured ''new tune'' emittance is {var_epsilon}= 8.05 {plus_minus} 0. 53 cm - mr or a normalized emittance of {var_epsilon}{sub n} = 943 {plus_minus} 63 mm - mr In 1990 the ETAII programmatic emphasis was on free electron lasers and the paramount parameter was whole beam brightness. The published brightness for ETAII after its first major rebuild was J = 1 - 3 x 10{sup 8} A/(m - rad){sup 2} at a current and energy of 1000-1400 Amperes and 2.5 MeV. The average normalized emittance derived from table 2 of that report is 864 mm-mr corresponding to a real emittance of 14.8 cm-mr.

  6. Performance of the compact 300 MeV electron ring JSR

    Science.gov (United States)

    Yokomizo, H.; Yanagida, K.; Harada, S.; Mashiko, K.; Yokoyama, M.; Hashimoto, H.; Nakayama, K.; Kabasawa, M.; Harami, T.; Suzuki, Y.

    1990-05-01

    A compact ring, JSR, has been constructed in a short period of 15 months. The magnets, vacuum chamber and rf system are well manufactured, coming up to the design expectation. The good-field region {ΔB}/{B} JSR at a maximum energy of 300 MeV. The lifetime of the stored electrons is ˜ 30 min, which is mainly determined by collisions with the residual gas in the vacuum chamber. JSR has proved to work correctly in the storage and acceleration of electrons within an energy range from 150 to 300 MeV.

  7. Intensity maps of MeV electrons and protons below the radiation belt

    International Nuclear Information System (INIS)

    The global distributions of energetic electrons (0.19 - 3.2 MeV) and protons (0.64 - 35 MeV) are shown in the form of contour maps. The data were obtained by two sets of energetic particle telescopes on board the satellite OHZORA. The observed altitude range is 350 - 850 Km. Ten degress meshes in longitude and latitude were used to obtain the intensity contours. A pitch angle distribution of J(α) = J(90). sinnα with n = 5A is assumed to get the average intensity in each mesh. (author)

  8. 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.

  9. Neutron response matrix for unfolding NE-213 measurements to 21 MeV

    International Nuclear Information System (INIS)

    A neutron response matrix from measured neutron responses of NE-213 in the energy range of 0.2 to 22 MeV is presented. An interpolation scheme was used to construct an 81-column matrix from the data of Verbinski, Burrus, Love, Zobel, and Hill. As a test of the new response matrix, the Cf-252 neutron spectrum was measured and unfolded using the new response matrix and the FORIST unfolding code. The spectrum agrees well with previous measurements at lower energies, while providing new information above 8 MeV

  10. Proton Polarimeter Calibration between 82 and 217 MeV

    Energy Technology Data Exchange (ETDEWEB)

    Glister, J; Lee, B; Beck, A; Brash, E; Camsonne, A; Choi, S; Dumas, J; Feuerbach, R; Gilman, R; Higinbotham, D W; Jiang, X; Jones, M K; May-Tal Beck, S; McCullough, E; Paolone, M; Piasetzky, E; Roche, J; Rousseau, Y; Sarty, A J; Sawatzky, B; Strauch, S

    2009-07-01

    The proton analyzing power in carbon has been measured for energies of 82 to 217 MeV and proton scattering angles of 5 to 41 degrees. The measurements were carried out using polarized protons from the elastic scattering H(pol. e, pol. p) reaction and the Focal Plane Polarimeter (FPP) in Hall A of Jefferson Lab. A new parameterization of the FPP p-C analyzing power was fit to the data, which is in good agreement with previous parameterizations and provides an extension to lower energies and larger angles. The main conclusions are that all polarimeters to date give consistent measurements of the carbon analyzing power, independently of the details of their construction and that measuring on a larger angular range significantly improves the polarimeter figure of merit at low energies.

  11. Neutron total and scattering cross sections of 6Li in the few MeV region

    International Nuclear Information System (INIS)

    Neutron total cross sections of 6Li are measured from approx. 0.5 to approx. 4.8 MeV at intervals of approx. 10 scattering angles and at incident-neutron intervals of approx.< 100 keV. Neutron differential inelastic-scattering cross sections are measured in the incident-energy range 3.5 to 4.0 MeV. The experimental results are extended to lower energies using measured neutron total cross sections recently reported elsewhere by the authors. The composite experimental data (total cross sections from 0.1 to 4.8 MeV and scattering cross sections from 0.22 to 4.0 MeV) are interpreted in terms of a simple two-level R-matrix model which describes the observed cross sections and implies the reaction cross section in unobserved channels; notably the (n;α)t reaction (Q = 4.783 MeV). The experimental and calculational results are compared with previously reported results as summarized in the ENDF/B-V evaluated nuclear data file

  12. Performance of the compact 300 MeV electron ring JSR

    International Nuclear Information System (INIS)

    A compact ring, JSR, has been constructed in a short period of 15 months. The magnets, vacuum chamber and rf system are well manufactured, coming up to the design expectation. The good-field region ΔB/B-4 extends over ±45 mm in the dipole magnets. The base pressure has reached 3x10-10 Torr at the pump head. An electron beam was successfully injected from a linac at an energy of ∝150 MeV, and electrons were smoothly accelerated and stored in JSR at a maximum energy of 300 MeV. The lifetime of the stored electrons is ∝30 min, which is mainly determined by collisions with the residual gas in the vacuum chamber. JSR has proved to work correctly in the storage and acceleration of electrons within an energy range from 150 to 300 MeV. (orig.)

  13. Relativistic analysis of nuclear ground state densities at 135 to 200 MeV

    Indian Academy of Sciences (India)

    M A Suhail; N Neeloffer; Z A Khan

    2005-12-01

    A relativistic analysis of p + 40Ca elastic scattering with different nuclear ground state target densities at 135 to 200 MeV is presented in this paper. It is found that the IGO densities are more consistent in reproducing the data over the energy range considered here. The reproduction of spin-rotation-function data with the simultaneous fitting of differential cross-section and analyzing power, and the appearance of wine-bottle-bottom shaped Re eff() in the transition energy region, sensitively depends on the input nuclear ground state densities and are not solely the relativistic characteristic signatures. We also found that the wine-bottle-bottom shaped Re eff() is preferred by the spin observables in the transition energy region (i.e. 181 MeV to 200 MeV).

  14. Study of calf thymus DNA irradiated in vitro with MeV fluorine ions

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    A study of the fragments of DNA irradiated with MeV ions is important for the understanding of the DNA damage mechanism and the subsequent biological effects (induced by heavy ions). In this experiment, the products of calf thymus DNA (CT DNA) irradiated with MeV fluorine ions were analyzed using agarose gel electrophoresis,modified time-of-flight mass spectrometer (MALDI-TOF), and high-performance liquid chromatography (HPLC).The results showed that the molecular mass of the fragments were concentrated around 831 bp with agarose gel electrophoresis, there was no observable product in the range of 1,000- 30,000 (m/q) using MALDI-TOF, and small biomolecules were separated from the products. The results of this study indicated that the strand breaks of calf thymus DNA induced by MeV fluorine ions were nonrandom.

  15. Study of calf thymus DNA irradiated in vitro with MeV fluorine ions

    International Nuclear Information System (INIS)

    A study of the fragments of DNA irradiated with MeV ions is important for the understanding of the DNA damage mechanism and the subsequent biological effects (induced by heavy ions). In this experiment, the products of calf thymus DNA (CT DNA) irradiated with MeV fluorine ions were analyzed using agarose gel electrophoresis, modified time-of-flight mass spectrometer (MALDI-TOF), and high-performance liquid chromatography (HPLC). The results showed that the molecular mass of the fragments were concentrated around 831 bp with agarose gel electrophoresis, there was no observable product in the range of 1,000-30,000 (m/q) using MALDI-TOF, and small biomolecules were separated from the products. The results of this study indicated that the strand breaks of calf thymus DNA induced by MeV fluorine ions were nonrandom. (authors)

  16. Dispersive spherical optical model of neutron scattering from Al27 up to 250 MeV

    CERN Document Server

    Molina, A; Quesada, J M; Lozano, M

    2002-01-01

    A spherical optical model potential (OMP) containing a dispersive term is used to fit the available experimental database of angular distribution and total cross section data for n + Al27 covering the energy range 0.1- 250 MeV using relativistic kinematics and a relativistic extension of the Schroedinger equation. A dispersive OMP with parameters that show a smooth energy dependence and energy independent geometry are determined from fits to the entire data set. A very good overall agreement between experimental data and predictions is achieved up to 150 MeV. Inclusion of nonlocality effects in the absorptive volume potential allows to achieve an excellent agreement up to 250 MeV.

  17. Measurement of the Am241(n,2n) reaction cross section from 7.6 MeV to 14.5 MeV

    Science.gov (United States)

    Tonchev, A. P.; Angell, C. T.; Boswell, M.; Crowell, A. S.; Fallin, B.; Hammond, S.; Howell, C. R.; Hutcheson, A.; Karwowski, H. J.; Kelley, J. H.; Pedroni, R. S.; Tornow, W.; Becker, J. A.; Dashdorj, D.; Kenneally, J.; Macri, R. A.; Stoyer, M. A.; Wu, C. Y.; Bond, E.; Chadwick, M. B.; Fitzpatrick, J.; Kawano, T.; Rundberg, R. S.; Slemmons, A.; Vieira, D. J.; Wilhelmy, J. B.

    2008-05-01

    The (n,2n) cross section of the radioactive isotope Am241 (T1/2=432.6 y) has been measured in the incident neutron energy range from 7.6 to 14.5 MeV in steps of a few MeV using the activation technique. Monoenergetic neutron beams were produced via the H2(d,n)He3 reaction by bombarding a pressurized deuterium gas cell with an energetic deuteron beam at the TUNL 10-MV Van de Graaff accelerator facility. The induced γ-ray activity of Am240 was measured with high-resolution HPGe detectors. The cross section was determined relative to Al, Ni, and Au neutron activation monitor foils, measured in the same geometry. Good agreement is obtained with previous measurements at around 9 and 14 MeV, whereas for a large discrepancy is observed when our data are compared to those reported by Perdikakis near 11 MeV. Very good agreement is found with the END-B/VII evaluation, whereas the JENDL-3.3 evaluation is in fair agreement with our data.

  18. Measurements of neutron spectra from iron and boron—in—polyethylene bomareded with 14MeV nuetrons

    Institute of Scientific and Technical Information of China (English)

    ZhouYu-Qing; ChenYuan; 等

    1997-01-01

    The leakage spectra of 14MeV neutrons from spheres of iron and boron-inpolyethylene with three differnet mass ratios of boron carbide to polyethylene were measured over the energy range of 20 keV to 16MeV by using proton recoil method.The integral leakages and removal cross sections at different lower cut-off energy were given.

  19. Study of the gamma spectra emitted in a nuclear reaction - Measurement of the half-lives of the levels 6.13 MeV, 6.92 MeV and 7.12 MeV of 16O

    International Nuclear Information System (INIS)

    When the energy shifts of the gamma spectrum released during a nuclear reaction are important compared with the detector resolution, the comparison of the experimental spectrum with theoretical spectra allows us to determine the half-life of the initial state of the transition. The calculation of the experimental spectrum implies to know the slowing-down of the recoil nucleus in the matter in order to take into account the Doppler effect. For recoil energies in the range of the MeV and for solid media, the Lindhard theory agrees well with experimental data. The phenomenon of deflection which appears at very low energies must be taken into account by restraining the measurement domain. By choosing an adequate media we can measure half-lives in the domain 1 and 100 fs without needing to take into account deflection effects. We have measured the half-life of the first 3 energy levels of 16O (6.135 MeV, 6.923 MeV and 7.121 MeV), these levels are reached through the reaction 19F(p,αγ)16O with proton incident energies ranging from 0.872 MeV to 2.42 MeV. We have used a coaxial germanium semi-conductor with lithium additions that was connected to an amplification line of Ortec type. 2 kinds of target have been used: calcium fluoride and copper fluoride evaporated on tantalum support. We have obtained the following values for the half-life: (16±4) fs for the 6.923 MeV level, (18±4) fs for the 7.121 MeV level, and for the 6.135 MeV we can only give a lower limit since the gamma decay occurs when the nucleus is at rest τ > 200 fs

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

    OpenAIRE

    Brejnholt, Nicolai F.; Soufli, Regina; Descalle, Marie-Anne; Fernandez-Perea, Monica; Christensen, Finn Erland; Jakobsen, Anders Clemen; Honkimaeki, Veijo; Pivovaroff, Michael J.

    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 multil...

  1. 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

  2. Neutron- and proton-induced evaluated transport library up to 150 MeV

    International Nuclear Information System (INIS)

    A new evaluated nuclear data library has been created. The library consists of two sub-libraries for neutron and proton incident particles. The neutron sub-library contains nuclear data for transport, heating and shielding applications for 242 nuclides with atomic numbers ranging from 8 to 82 in the energy region of primary neutrons from 10-5 eV to 150 MeV. Data below 20 MeV are taken mainly from ENDF/B-VI (revision 8) and for some nuclides, from the JENDL-3.3 and JEFF-3.0 libraries. The proton sub-library should contain data for the same range of target nuclides and energies. Proton-induced evaluated cross-section files are available for 15 nuclides at the moment. The evaluation of emitted particle energy and angular distributions at energies above 20 MeV (for incident neutrons) and above the reaction threshold (for incident protons) was performed with the help of the ALICE/ASH code and the analysis of available experimental data. The total cross-sections, elastic cross-sections and elastic scattering angular distributions were calculated with the help of the coupled channel model. The results of the calculation were adjusted to the data from ENDF/B-VI, JENDL-3.3, or JEFF-3.0 at the neutron energy equal to 20 MeV. The library is written in ENDF-6 format using the MF=3/MT=5 and MF=6/MT=5 representations

  3. 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).

  4. Modification of ROSPEC to cover neutrons from thermal to 18 MeV.

    Science.gov (United States)

    Ing, H; Djeffal, S; Clifford, T; Li, L; Noulty, R; Machrafi, R

    2007-01-01

    Rotating Spectrometer (ROSPEC) is a neutron spectrometer designed to measure neutron energy distributions, and provide accurate neutron dosimetry. It is a completely self-contained unit and measures neutron energy via recoiling protons in gas proportional counters. Each of the four original gas counters is dedicated to a particular neutron energy range dictated by sensitivity to gamma rays at the low energy end of the spectrum and by proton collisions with the counter walls at the high energy end. Introduced originally in 1992, ROSPEC has a proven operational record with a program of continued upgrades. The operating range of the original ROSPEC spans 50 keV-4.5 MeV. The range of the ROSPEC has now been extended down to include epithermal and thermal neutrons by adding two 2 in. (3)He counters. Also, an optional simple scintillation spectrometer was designed to extend the upper limit of ROSPEC up to 18 MeV.

  5. 10 MeV Medical Cyclotron Prototype Beam Commissioning

    Institute of Scientific and Technical Information of China (English)

    GUAN; Feng-ping; GE; Tao; YIN; Zhi-guo; SONG; Guo-fang; ZHANG; Tian-jue; JI; Bin; LI; Peng-zhan; CAO; Lei; HOU; Shi-gang; LIU; Geng-shou; WANG; Feng; LEI; Yu; WU; Long-cheng; WEN; Li-peng; LI; Zhen-guo; CUI; Tao; JIA; Xian-lu; YAO; Hong-juan; PAN; Gao-feng; ZHANG; Su-ping; CAI; Hong-ru; XIE; Huai-dong

    2012-01-01

    <正>A 10 MeV medical cyclotron prototype for the production of short-lived isotopes has been developed independently at CIAE with a time span of 2 years. On the inner target, 8 hours stability test has been finished. The extraction beam is 10 MeV with a beam intensity of 100 μA.

  6. 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.)

  7. Dosimetric comparison of 4 MeV and 6 MeV electron beams for total skin irradiation

    International Nuclear Information System (INIS)

    In this study, dosimetric aspects of TSEI consisting of a 4 MeV beam with no spoiler were investigated in comparison to a nominal 6 MeV beam with spoiler, and the potential for clinical applications was evaluated. The TSEI technique is based on the Stanford technique, which utilizes a beam configuration of six-dual fields. MOSFETs were used to measure the optimal gantry angle, profile uniformity, and absolute dose at the calibration point. The depth dose curve of the central axis was measured in the treatment plane using EBT2 film. Photon contamination was measured as the dose at 5 cm depth in a solid water phantom relative to the maximum dose using a parallel plate ion chamber. A MOSFET dosimeter placed on the surface of a humanoid phantom, and EBT2 films inserted into a humanoid phantom were used to verify the TSEI commissioning. Dosimetric aspects of the 4 MeV TSEI beam, such as profile uniformity (±10%) and relative photon contamination (<0.001%), were comparable to those of a 6 MeV TSEI beam. The relative depth dose of the 4 MeV electrons was 81.4% at the surface and 100% at 0.4 cm. For the 6 MeV electrons, the relative depth dose was 93.4% at the surface and 100% from 0.2 cm to 0.4 cm. The calculated B-factor of the 4 MeV TSEI beam was 1.55, and 1.53 for the 6 MeV TSEI. 80% of the prescribed dose was obtained at 0.22 cm depth for the 4 MeV TSEI beam and 0.53 cm for the 6 MeV TSEI beam in the humanoid phantom measurement. The suggested 4 MeV beam for TSEI could be applied to shallow depth skin diseases and to electron boost as second treatment course

  8. RF Operation for the 100MeV Proton Linac

    Energy Technology Data Exchange (ETDEWEB)

    Seol, Kyung Tae; Kwon, Hyeok Jung; Kim, Dae Il; Kim, Han Sung; Song, Young Gi; Jang, Ji Ho; Cho, Yong Sub [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2013-10-15

    The RF systems for the 100MeV linac were constructed. The HPRF system including klystrons, circulators, high power dummy loads, and waveguide components was installed at the klystron gallery, and the LLRF control systems including a commercial FPGA module and a LLRF analog chassis were also installed. The phase stability of the RF reference line was measured with S11 phase under temperature control. The RF systems for 100MeV linac have been operated for a beam commissioning, and the 100MeV proton beam has been supplied to users currently. The RF systems of the 100MeV proton linac for the KOMAC (KOrea Multi-purpose Accelerator Complex) were installed at the Gyeong-ju site. The 100MeV linac consists of a 3MeV RFQ, a 20MeV DTL with four tanks, two MEBT tanks, and seven 100MeV DTL tanks. For the 100MeV linac, nine sets of LLRF control systems and the HPRF systems including 1MW klystrons, circulators and waveguide components have been installed at the klystron gallery, and four high voltage converter modulators to drive nine klystrons have been installed at the modulator room. A RF reference system distributing 300MHz LO signal to each RF control system has also been installed with a temperature control system at the klystron gallery. The requirement of RF field control is within +/- 1% in RF amplitude and +/- 1 degree in RF phase. The RF systems have been operated for the beam commissioning. The installation and operation of the RF system for the 100MeV proton linac are presented in this paper.

  9. 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...

  10. Two Nucleon Systems at $m_\\pi\\sim 450~{\\rm MeV}$ from Lattice QCD

    CERN Document Server

    Orginos, Kostas; Savage, Martin J; Beane, Silas R; Chang, Emmanuel; Detmold, William

    2015-01-01

    Nucleon-nucleon systems are studied with lattice quantum chromodynamics at a pion mass of $m_\\pi\\sim 450~{\\rm MeV}$ in three spatial volumes using $n_f=2+1$ flavors of light quarks. At the quark masses employed in this work, the deuteron binding energy is calculated to be $B_d = 14.4^{+3.2}_{-2.6} ~{\\rm MeV}$, while the dineutron is bound by $B_{nn} = 12.5^{+3.0}_{-5.0}~{\\rm MeV}$. Over the range of energies that are studied, the S-wave scattering phase shifts calculated in the 1S0 and 3S1-3D1 channels are found to be similar to those in nature, and indicate repulsive short-range components of the interactions, consistent with phenomenological nucleon-nucleon interactions. In both channels, the phase shifts are determined at three energies that lie within the radius of convergence of the effective range expansion, allowing for constraints to be placed on the inverse scattering lengths and effective ranges. The extracted phase shifts allow for matching to nuclear effective field theories, from which low energy...

  11. Evaluated Nuclear Data Library for Transport Calculations at Energies up to 150 MeV

    International Nuclear Information System (INIS)

    A new evaluated nuclear data library has been created. The library consists of two sub-libraries for neutron and proton incident particles. The first version of neutron sub-library has been completed and described in the present paper. The library contains nuclear data for transport, heating, and shielding applications for 242 nuclides ranging in atomic number from 8 to 82 in the energy region of primary neutrons from 10-5 eV to 150 MeV. Data below 20 MeV are taken mainly from ENDF/B-VI (Revision 8) and for some nuclides, from the JENDL-3.3 and JEFF-3.0 libraries. The evaluation of emitted particle energy and angular distributions at the energies above 20 MeV was performed with the help of the ALICE/ASH code and the analysis of available experimental data. The total cross sections, elastic cross sections, and elastic scattering angular distributions were calculated with the help of the coupled channel model. The results of the calculation were adjusted to the data from ENDF/B-VI, JENDL-3.3m or JEFF-3.0 at the neutron energy equal to 20 MeV. The library is written in ENDF/B-VI format using the MF=3/MT=5 and MF=6/MT=5 representations

  12. Neutron-induced fission cross sections of 242Pu from 0.3 MeV to 3 MeV

    Science.gov (United States)

    Salvador-Castiñeira, P.; Bryś, T.; Eykens, R.; Hambsch, F.-J.; Göök, A.; Moens, A.; Oberstedt, S.; Sibbens, G.; Vanleeuw, D.; Vidali, M.; Pretel, C.

    2015-10-01

    The majority of the next generation of nuclear power plants (GEN-IV) will work in the fast-neutron-energy region, as opposed to present day thermal reactors. This leads to new and more accurate nuclear-data needs for some minor actinides and structural materials. Following those upcoming demands, the Organisation for Economic Cooperation and Development Nuclear Energy Agency performed a sensitivity study. Based on the latter, an improvement in accuracy from the present 20% to 5% is required for the 242Pu(n ,f ) cross section. Within the same project both the 240Pu(n ,f ) cross section and the 242Pu(n ,f ) cross section were measured at the Van de Graaff accelerator of the Joint Research Centre at the Institute for Reference Materials and Measurements, where quasimonoenergetic neutrons were produced in an energy range from 0.3 MeV up to 3 MeV. 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 three different isotopes: 237Np(n ,f ) , 235U(n ,f ) , and 238U(n ,f ) . A comprehensive study of the corrections applied to the data and the uncertainties associated is given. The results obtained are in agreement with previous experimental data at the threshold region up to 0.8 MeV. The resonance-like structure at 0.8 to 1.1 MeV, visible in the evaluations and in most previous experimental values, was not reproduced with the same intensity in this experiment. For neutron energies higher than 1.1 MeV, the results of this experiment are slightly lower than the Evaluated Nuclear Data File/B-VII.1 evaluation but in agreement with the experiment of Tovesson et al. (2009) as well as Staples and Morley (1998). Finally, for energies above 1.5 MeV, the results show consistency with the present evaluations.

  13. Response of detector modules of the neutron hodoscope SENECA to neutrons with energies 7-70 MeV

    Science.gov (United States)

    v. Edel, G.; Selke, O.; Pöch, C.; Smend, F.; Schumacher, M.; Nolte, R.; Schrewe, U.; Brede, H. J.; Schuhmacher, H.; Henneck, R.

    1993-07-01

    SENECA is a hodoscope for recoil neutrons from photoreactions on nuclei and nucleons in the photon energy range 50-900 MeV. It consists of 32 hexagonal scintillation detector modules in a honeycomb array. Differential detection efficiency spectra of a single module as well as the cross-talk between neighbouring modules were measured at neutron energies between 7 and 70 MeV. Neutron detection efficiencies were determined in the same energy range with an average experimental uncertainty of 7.6%. The experimental results agree with predictions from Monte Carlo codes within the limits of the experimental error.

  14. Factors determining the lifetime damage coefficients and the low-frequency noise in MeV proton irradiated silicon diodes

    International Nuclear Information System (INIS)

    The impact of several factors, related to the doping density, the substrate type and the thermal pre-treatment on the proton radiation damage coefficients of Si diodes is discussed and verified experimentally. The diode parameters investigated are the leakage current density, the recombination lifetime and the low-frequency noise current spectral density. Proton irradiations have been performed in the energy range 10 MeV to 100 MeV and in the fluence range of 5 x 109 to 4 x 1011 cm-2, typical for space applications. The obtained coefficients are compared with theoretical NIEL predictions. (author)

  15. 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...

  16. Ternary fission with 4He emission in 16O(144 Mev) + 232Th and 12C(108 Mev) + 197Au reactions

    International Nuclear Information System (INIS)

    Results of coincidence study of 4He emission with fission fragments in 12C (108 MeV) ions with sup(197)Au target and 16O (144 MeV) ions with sup(223)Th target reactions are presented. On the basis of Monte Carlo kinematic simulation of nuclear reactions analysis of energy and velocity spectra of α-particles has been performed. The conclusion has been performed. The conclusion has been drawn that the main source of 4He emission was the evaporation from a fissioning compound nucleus. Substantial part of α-particles was emitted from fully accelerated fission fragments. Some of 4He nuclei with mean energy of about 16 MeV emitted mainly perpendicular to the fission axis were identified as similar to long range α-particles in ternary fission of heavy nuclei with low excitation energy. Multiplicities of emission of these particles are considerably higher than those at low excitation energy. Comparison of experimental results with statistical model calculations has been made

  17. Ion desorption from frozen H 2O irradiated by MeV heavy ions

    Science.gov (United States)

    Collado, V. M.; Farenzena, L. S.; Ponciano, C. R.; Silveira, E. F. da; Wien, K.

    2004-10-01

    Nitrogen (0.13-0.85 MeV) and 252Cf fission fragments (˜65 MeV) beams are employed to sputter positive and negative secondary ions from frozen water. Desorption yields are measured for different ice temperatures and projectile energies. Target surface is continuously refreshed by condensed water while the target temperature varies and ice thickness changes. In both projectile energy ranges, the preferentially ejected ions are H +, H2+ and (H 2O) nH +-cluster ions. The yields of the corresponding negative ions H - and (H 2O) nO - or (H 2O) nOH - are 1-2 orders of magnitude lower. The (H 2O) nH + desorption yields decrease exponentially as the cluster size, n, increases. In the low energy range, the desorption of positive ion clusters may occur in a two-step process: first, desorption of preformed H 2O clusters and, then, ionization by H + or H 3O + capture. For 0.81 MeV N + projectile ions, the cluster ion emission contributes with 0.05% to the total H 2O desorbed yield. There are indications that emission of the (H 2O) nH + disappears for an electronic energy loss lower than 20 eV/Å. For the high energy range, desorption of small ion clusters is particularly enhanced, revealing that a fragmentation process also exists.

  18. 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.

  19. The reaction π+ + d = 2p in the 300 MeV range

    International Nuclear Information System (INIS)

    The inelastic pion deuteron scattering is studied for pion impulses in the centre-of-mass system at 50 to 300 MeV/c and polarization effects in the reaction p + p = π+ + d for the case of polarized protons are analyzed too. A detailed comparison with experiments is given. (author)

  20. Dosimetric comparison of 4 MeV and 6 MeV electron beams for total skin irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jung In; Park, So Yeon; Park, Jong Min; Ye, Sung Joon; Kim, Il Han [Dept. of Radiation Oncology, Seoul National University Hospital, Seoul (Korea, Republic of)

    2014-11-15

    Total skin electron irradiation (TSEI) was developed by Stanford University in the 1950s and introduced for the treatment of mycosis fungoides, the most common form of cutaneous T-cell lymphoma which generally affects the skin. In this study, dosimetric aspects of TSEI consisting of a 4 MeV beam with no spoiler were investigated in comparison to a nominal 6 MeV beam applications was evaluated. The suggested 4 MeV beam for TSEI could be applied to shallow depth skin diseases and to electron boost as second treatment course.

  1. Neutron doses in an 8 MeV linear accelerator and an 18 MeV betatron

    International Nuclear Information System (INIS)

    Using uranium fission track dosimeters, dose distributions of neutrons produced by photonuclear reaction in the shielding material were measured near an 8 MeV linear accelerator and an 18 MeV betatron. Dose equivalents, as a function of bremsstrahlung doses in the central beam, are given for different points outside the irradiation field, in particular at the location of the patient. The neutron production was determined as a function of photon energy between 8 and 18 MeV and compared with literature values. (orig./HP)

  2. Experiments on n-p scattering with 260-Mev neutrons

    Energy Technology Data Exchange (ETDEWEB)

    Kelley, E.; Segre, E.; Leith, C.; Wiegand, C.

    1950-03-06

    Neutrons produced by 350 Mev protons impinging on beryllium are scattered by hydrogen. The authors measure the differential scattering cross section as a function of the scattering angle. Results are summarized here.

  3. EXPERIMENTS ON N-P SCATTERING WITH 260 MEV NEUTRONS

    Energy Technology Data Exchange (ETDEWEB)

    Kelly, E.; Leith, C.; Segre, E.; Wiegand, C.

    1950-03-06

    Neutrons produced by 350 Mev protons impinging on beryllium are scattered by hydrogen. We measure the differential scattering cross section as a function of the scattering angle. Results are summarized in Fig. 3 of the paper.

  4. Comprehensive Measurement of Neutron Yield Produced by 62 MeV Protons on Beryllium Target

    International Nuclear Information System (INIS)

    A low-power prototype of neutron amplifier, based on a 70 MeV, high current proton cyclotron being installed at LNL for the SPES RIB facility, was recently proposed within INFN-E project. This prototype uses a thick Beryllium converter to produce a fast neutron spectrum feeding a sub-critical reactor core. To complete the design of such facility the new measurement of neutron yield from a thick Beryllium target was performed at LNS. This measurement used liquid scintillator detectors to identify produced neutrons by Pulse Shape Discrimination and Time of Flight technique to measure neutron energy in the range 0.5-62 MeV. To extend the covered neutron energy range 3He detector was used to measure neutrons below 0.5 MeV. The obtained yields were normalized to the charge deposited by the proton beam on the metallic Beryllium target. These techniques allowed to achieve a wide angular coverage from 0 to 150 degrees and to explore almost complete neutron energy interval. (authors)

  5. Cross sections from proton irradiation of thorium at 800 MeV

    CERN Document Server

    Engle, Jonathan W; Weidner, John W; Wolfsberg, Laura E; Fassbender, Michael E; Jackman, Kevin; Couture, Aaron; Bitteker, Leo J; Ullmann, John L; Gulley, Mark S; Pillai, Chandra; John, Kevin D; Birnbaum, Eva R; Nortier, Francois M

    2013-01-01

    Nuclear formation cross sections are reported for 65 nuclides produced from 800-MeV proton irradiation of thorium foils. These data are useful as benchmarks for computational predictions in the ongoing process of theoretical code development and also to the design of spallation-based radioisotope production currently being considered for multiple radiotherapeutic pharmaceutical agents. Measured data are compared with the predictions of three MCNP6 event generators and used to evaluate the potential for 800-MeV productions of radioisotopes of interest for medical radiotherapy. In only a few instances code predictions are discrepant from measured values by more than a factor of two, demonstrating satisfactory predictive power across a large mass range. Similarly, agreement between measurements presented here and those previously reported is good, lending credibility to predictions of target yields and radioimpurities for high-energy accelerator-produced radionuclides.

  6. Underwater Ranging

    Directory of Open Access Journals (Sweden)

    S. P. Gaba

    1984-01-01

    Full Text Available The paper deals with underwater laser ranging system, its principle of operation and maximum depth capability. The sources of external noise and methods to improve signal-to-noise ratio are also discussed.

  7. Response of electret dosemeters to eletrons with energies of 3 MeV, 7 MeV, 11 MeV

    International Nuclear Information System (INIS)

    The response of the electret dosemeter to electrons of 3,7 and 11 MeV from an accelerator Mevatron 12 is studied. Two external coatings (polyethylene or nylon) are used and a comparative evaluation is presented. (M.A.C.)

  8. (19)F(α,n) thick target yield from 3.5 to 10.0 MeV.

    Science.gov (United States)

    Norman, E B; Chupp, T E; Lesko, K T; Grant, P J; Woodruff, G L

    2015-09-01

    Using a target of PbF2, the thick-target yield from the (19)F(α,n) reaction was measured from E(α)=3.5-10 MeV. From these results, we infer the thick-target neutron yields from targets of F2 and UF6 over this same alpha-particle energy range. PMID:26115205

  9. (19)F(α,n) thick target yield from 3.5 to 10.0 MeV.

    Science.gov (United States)

    Norman, E B; Chupp, T E; Lesko, K T; Grant, P J; Woodruff, G L

    2015-09-01

    Using a target of PbF2, the thick-target yield from the (19)F(α,n) reaction was measured from E(α)=3.5-10 MeV. From these results, we infer the thick-target neutron yields from targets of F2 and UF6 over this same alpha-particle energy range.

  10. Thermal-neutron-capture prompt-gamma emission spectra of representative coals. [1. 5 to 11 MeV

    Energy Technology Data Exchange (ETDEWEB)

    Herzenberg, C L; Olson, I K

    1981-12-01

    Prompt gamma ray emission spectra have been calculated from 1.5 to 11 MeV for a wide range of coal compositions exposed to a thermal neutron flux. These include contributions to the spectra from all of the major and minor elements present in the coals. Characteristics of the spectra are discussed and correlated with the coal compositions.

  11. 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)

  12. Proton-induced cross sections relevant to production of 225Ac and 223Ra in natural thorium targets below 200 MeV

    CERN Document Server

    Weidner, J W; John, K D; Hemez, F; Ballard, B; Bach, H; Birnbaum, E R; Bitteker, L J; Couture, A; Dry, D; Fassbender, M E; Gulley, M S; Jackman, K R; Ullmann, J L; Wolfsberg, L E; Nortier, F M

    2012-01-01

    Cross sections for 223,225Ra, 225Ac and 227Th production by the proton bombardment of natural thorium targets were measured at proton energies below 200 MeV. Our measurements are in good agreement with previously published data and offer a complete excitation function for 223,225Ra in the energy range above 90 MeV. Comparison of theoretical predictions with the experimental data shows reasonable-to-good agreement. Results indicate that accelerator-based production of 225Ac and 223Ra below 200 MeV is a viable production method.

  13. Semiclassical distorted wave model analysis of inclusive (N, N'x) reactions for incident energies up to 400 MeV

    International Nuclear Information System (INIS)

    The semiclassical distorted wave (SCDW) model with the Wigner transform of a one-body density matrix is applied to analyses of multistep direct processes in (p, p'x) reactions on 12C, 90Zr, and 197Au at incident energies near 150 MeV, and 392 MeV (p, p'x) and 346 MeV (p, nx) reactions on 40Ca. The calculations show good agreement with experimental double-differential cross sections over a wide mass range of target nuclei, except at backward angles. (author)

  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. 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...

  16. 25Na and 25Mg fragmentation on 12C at 9.23 MeV per nucleon at TRIUMF

    International Nuclear Information System (INIS)

    HERACLES is a multidetector that is used to study heavy-ion collisions, with ion beams with an energy range between 8 to 15 MeV per nucleon. It has 78 detectors axially distributed around the beam axis in 6 rings allowing detection of multiple charged fragments from nuclear reactions. HERACLES has 4 different types of detectors, BC408/BaF2 phoswich, Si/CsI(Tl) telescope, BC408/BC444 phoswich and CsI(Tl) detectors. The multidetector has been run with a radioactive 25Na beam and a stable 25Mg beam at 9.23 MeV per nucleon on a carbon target.

  17. 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.

  18. Response of AGATA segmented HPGe detectors to gamma rays up to 15.1 MeV

    Energy Technology Data Exchange (ETDEWEB)

    Crespi, F.C.L., E-mail: fabio.crespi@mi.infn.it [Dipartimento di Fisica, Università di Milano, Milano I-20133 (Italy); INFN, Sezione di Milano, Milano I-20133 (Italy); Avigo, R.; Camera, F. [Dipartimento di Fisica, Università di Milano, Milano I-20133 (Italy); INFN, Sezione di Milano, Milano I-20133 (Italy); Akkoyun, S. [Department of Physics, Faculty of Science, Cumhuriyet University, Campus 58140, Sivas (Turkey); Ataç, A. [Department of Physics, Faculty of Science, Ankara University, Tandoðan 06100, Ankara (Turkey); Bazzacco, D; Bellato, M. [INFN, Sezione di Padova, Padova I-35131 (Italy); Benzoni, G.; Blasi, N. [INFN, Sezione di Milano, Milano I-20133 (Italy); Bortolato, D. [INFN, Laboratori Nazionali di Legnaro, Legnaro IT-35020 (Italy); Bottoni, S.; Bracco, A. [Dipartimento di Fisica, Università di Milano, Milano I-20133 (Italy); INFN, Sezione di Milano, Milano I-20133 (Italy); Brambilla, S. [INFN, Sezione di Milano, Milano I-20133 (Italy); Bruyneel, B. [CEA-Saclay DSM/IRFU/SPhN, Gif-sur-Yvette 91191 (France); Ceruti, S. [Dipartimento di Fisica, Università di Milano, Milano I-20133 (Italy); INFN, Sezione di Milano, Milano I-20133 (Italy); Ciemała, M. [The Niewodniczanski Institute of Nuclear Physics, Polish Academy of Sciences, 31-342 Krakow (Poland); Coelli, S. [INFN, Sezione di Milano, Milano I-20133 (Italy); Eberth, J. [Institut für Kernphysik, Universität zu Köln, Zülpicher Str. 77, Köln D-50937 (Germany); Fanin, C.; Farnea, E. [INFN, Sezione di Padova, Padova I-35131 (Italy); and others

    2013-03-21

    The response of AGATA segmented HPGe detectors to gamma rays in the energy range 2–15 MeV was measured. The 15.1 MeV gamma rays were produced using the reaction d({sup 11}B,nγ){sup 12}C at E{sub beam}=19.1 MeV, while gamma rays between 2 and 9 MeV were produced using an Am–Be–Fe radioactive source. The energy resolution and linearity were studied and the energy-to-pulse-height conversion resulted to be linear within 0.05%.Experimental interaction multiplicity distributions are discussed and compared with the results of Geant4 simulations. It is shown that the application of gamma-ray tracking allows a suppression of background radiation caused by n-capture in Ge nuclei. Finally the Doppler correction for the 15.1 MeV gamma line, performed using the position information extracted with Pulse-shape analysis is discussed.

  19. Field Flatness Tuning for PEFP 100 MeV DTL

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Han-Sung; Kwon, Hyeok-Jung; Seol, Kyung-Tae; Kim, Dae-Il; Cho, Yong-Sub [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2008-05-15

    A conventional 100 MeV drift tube linac is under development for Proton Engineering Frontier Project. Currently the proton linac up to 20 MeV, which consists of injector, 3 MeV RFQ and 20 MeV DTL is completed. To accelerate the proton beam up to 100 MeV additional 7 DTL tanks are required. The DTL should be tuned after fabrication and alignment of the drift tube inside the tank to meet the requirements from the beam dynamics. Tuning process includes the resonant frequency tuning, field flatness tuning and tilt sensitivity tuning. The tuning goal for the field flatness tuning is less than {+-}2% in field uniformity throughout the DTL tank with less than {+-}% standard deviation. A non-uniform field profile caused by the machining errors and alignment errors can be made uniform through the slug tuner adjustment. This procedure requires the field profile measurements and several iterations between the field profile measurements and adjustment. The methods and the results of the DTL field flatness tuning will be reported in this presentation.

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

    International Nuclear Information System (INIS)

    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 (16O(n,p)16N→16O⁎→16O+γ). 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 228Th decay chain, the highest energy gamma ray available from a natural radionuclide. The 7.13 s half-life of the 16N 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, 238Pu/13C, shows that the low-energy continuum from the facility is reduced by a factor ∼30 and the gamma-ray rate is ∼100 times higher at 6.129 MeV

  1. Heavy-ion hot hadron matter freezes out at T=170-320 MeV?

    CERN Document Server

    Vovchenko, Volodymyr

    2015-01-01

    The conventional hadron-resonance gas (HRG) model with the Particle Data Group (PDG) hadron input and the mass dependent eigenvolume corrections is employed to fit the ALICE hadron mid-rapidity yield data on the most central Pb+Pb collisions. For the case of the point-like hadrons a well-known fit result of $T \\sim 155$ MeV is reproduced. However, when we apply the eigenvolume corrections with the mass-proportional eigenvolume $v_i \\sim m_i$, fixed to the realistic proton hard-core radius $r_p \\simeq 0.4-0.5$ fm, we observe a second minimum in the temperature dependence of the $\\chi^2$, located at the significantly higher temperatures. For instance, at $r_p = 0.5$ fm the fit quality is better than in the point-particle HRG case in a very wide temperature range of $170-320$ MeV, with the global minimum located at $T \\simeq 275$ MeV and $\\chi^2/N_{\\rm dof} \\simeq 1.5$. These results show that one cannot extract the chemical freeze-out temperature with high reliability from the LHC hadron yield data. Implication...

  2. 1 MeV, 10 kW DC electron accelerator for industrial applications

    Science.gov (United States)

    Nayak, B.; Acharya, S.; Bhattacharjee, D.; Bakhtsingh, R. I.; Rajan, R.; Sharma, D. K.; Dewangan, S.; Sharma, V.; Patel, R.; Tiwari, R.; Benarjee, S.; Srivastava, S. K.

    2016-03-01

    Several modern applications of radiation processing like medical sterilization, rubber vulcanization, polymerization, cross-linking and pollution control from thermal power stations etc. require D.C. electron accelerators of energy ranging from a few hundred keVs to few MeVs and power from a few kilowatts to hundreds of kilowatts. To match these requirements, a 3 MeV, 30 kW DC electron linac has been developed at BARC, Mumbai and current operational experience of 1 MeV, 10 kW beam power will be described in this paper. The LINAC composed mainly of Electron Gun, Accelerating Tubes, Magnets, High Voltage source and provides 10 kW beam power at the Ti beam window stably after the scanning section. The control of the LINAC is fully automated. Here Beam Optics study is carried out to reach the preferential parameters of Accelerating as well as optical elements. Beam trials have been conducted to find out the suitable operation parameters of the system.

  3. 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.

    2015-08-01

    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 of the present study therefore was to validate the 2-MEV scale based on a large data basis of 10,676 children collected over an eight-year period. Cohorts of three different US states contributed to the sample by responding to a paper-and-pencil questionnaire within their pre-test initiatives in the context of field center programs. Since we used only the pre-program 2-MEV scale results (which is before participation in education programs), the data were clearly unspoiled by any follow-up interventions. The purpose of analysis was fourfold: First, to test and confirm the hypothesized factorized structure for the large data set and for the subsample of each of the three states. Second, to analyze the scoring pattern across the eight years' time range for both preservation and utilitarian preferences. Third, to investigate any age effects in the extracted factors. Finally, to extract suitable recommendations for educational implementation efforts.

  4. 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.

  5. Resolution considerations in MeV ion microscopy and lithography

    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 Sciences and Agricultural Technology, Rajamangala University of Technology Lanna, Chiang Rai, 57120 Chiang Rai (Thailand); 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

    There a disparity between the way the resolution is specified in microscopy and lithography using light compared to MeV ion microscopy and lithography. In this work we explore the implications of the way the resolution is defined with a view to answering the questions; how are the resolving powers in MeV ion microscopy and lithography relate to their optical counterparts? and how do different forms of point spread function affect the modulation transfer function and the sharpness of the edge profile?.

  6. Earth albedo neutrons from 10 to 100 MeV.

    Science.gov (United States)

    Preszler, A. M.; Simnett, G. M.; White, R. S.

    1972-01-01

    We report the measurement of the energy and angular distributions of earth albedo neutrons from 10 to 100 MeV at 40 deg N geomagnetic latitude from a balloon at 120,000 ft, below 4.65 g/sq cm. The albedo-neutron omnidirectional energy distribution is flat to 50 MeV, then decreases with energy. The absolute neutron energy distribution is of the correct strength and shape for the albedo neutrons to be the source of the protons trapped in earth's inner radiation belt.

  7. 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.

  8. Development of mass spectrometry by high energy focused heavy ion beam: MeV SIMS with 8 MeV Cl{sup 7+} beam

    Energy Technology Data Exchange (ETDEWEB)

    Jeromel, Luka [Jožef Stefan Institute, Jamova 39, SI-1000 Ljubljana (Slovenia); Siketić, Zdravko [Ruđer Bošković Institute, P.O. Box 180, 10000 Zagreb (Croatia); Ogrinc Potočnik, Nina [Jožef Stefan Institute, Jamova 39, SI-1000 Ljubljana (Slovenia); LOTRIČ Metrology Ltd., Selca 163, SI-4227 Selca (Slovenia); Vavpetič, Primož; Rupnik, Zdravko; Bučar, Klemen [Jožef Stefan Institute, Jamova 39, SI-1000 Ljubljana (Slovenia); Pelicon, Primož, E-mail: primoz.pelicon@ijs.si [Jožef Stefan Institute, Jamova 39, SI-1000 Ljubljana (Slovenia)

    2014-08-01

    Particle induced X-ray emission (PIXE) at microprobe of Jožef Stefan Institute is used to measure two-dimensional quantitative elemental maps of biological tissue. To improve chemical and biological understanding of the processes in vivo, supplementary information about chemical bonding and/or molecular distributions could be obtained by heavy-ion induced molecular desorption and a corresponding mass spectroscopy with Time-Of-Flight (TOF) mass spectrometer. As the method combines the use of heavy focused ions in MeV energy range and TOF Secondary Ion Mass Spectrometry, it is denoted as MeV SIMS. At Jožef Stefan Institute, we constructed a linear TOF spectrometer and mount it to our multipurpose nuclear microprobe. A beam of 8 MeV {sup 35}Cl{sup 7+} could be focused to a diameter of better than 3 μm × 3 μm and pulsed by electrostatic deflection at the high-energy side of accelerator. TOF mass spectrometer incorporates an 1 m long drift tube and a double stack microchannel plate (MCP) as a stop detector positioned at the end of the drift path. Secondary ions are focused at MCP using electrostatic cylindrical einzel lens. Time of flight spectra are currently acquired with a single-hit time-to-digital converter. Pulsed ion beam produces a shower of secondary ions that are ejected from positively biased target and accelerated towards MCP. We start our time measurement simultaneously with the start of the beam pulse. Signal of the first ion hitting MCP is used to stop the time measurement. Standard pulses proportional to the time of flight are produced with time to analog converter (TAC) and fed into analog-to-digital converter to obtain a time histogram. To enable efficient detection of desorbed fragments with higher molecular masses, which are of particular interest, we recently implemented a state-of art Field Programmable Gate Array (FPGA)-based multi-hit TOF acquisition. To test the system we used focused 8 MeV {sup 35}Cl{sup 7+} ion beam with pulse length of

  9. The 400 MeV Linac Upgrade at Fermilab

    Energy Technology Data Exchange (ETDEWEB)

    Noble, R.J.

    1992-12-01

    The Fermilab Linac Upgrade in planned to increase the energy of the H{sup {minus}} linac from 200 to 400 MeV. This is intended to reduce the incoherent space-charge tuneshift at injection into the 8 GeV Booster which limit either the brightness or the total intensity of the beam. The Linac Upgrade will be achieved by replacing the last four 201.25 MHs drift-tube linac (DTL) tanks which accelerate the beam from 116 to 200 MeV, with seven 805 MRs side-coupled cavity modules operating at an average axial field of about 7.5 MV/meter. This will allow acceleration to 400 MeV in the existing Linac enclosure. Each accelerator module will be driven with a 12 MW klystron-based rf power supply. Three of seven accelerator modules have been fabricated, power tested and installed in their temporary location adjacent to the existing DTL. All seven RF Modulators have been completed and klystron installation has begun. Waveguide runs have completed from the power supply gallery to the accelerator modules. The new linac will be powered in the temporary position without beam in order to verify overall system reliability until the laboratory operating schedule permits final conversion to 400 MeV operation.

  10. 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...

  11. 200 MeV RF linac for synchrotron injection

    International Nuclear Information System (INIS)

    Construction has been completed on an electron linear accelerator for the Brookhaven National Laboratory. This accelerator will be used for the injection of a 200 MeV electron beam into a synchrotron for lithography experiments. This paper describes the conceptual design of the linac, its e-gun pulser, and its control and timing systems. 3 figs., ref

  12. 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).

  13. Germination of arabidopsis thaliana seeds irradiated by MeV ions

    International Nuclear Information System (INIS)

    Dry seeds of Arabidopsis thaliana were irradiated with F ions and H ions with the energy range from keV to MeV, respectively. The inhibition of germination was investigated to display the influences of ion mass, energy and fluence. The results show that H ion irradiation is more effective in decreasing the germination rate than heavier F ion irradiation. After irradiation of F ions, a decrease-increase-decease type of germination rate-fluence response curve was found and the ion fluence at the peak position decreases with ion energy increase. The possible mechanism of above experimental results is discussed in this paper. (authors)

  14. MeV Mono-Energetic Gamma Ray Compton Scattering Source R&D

    Science.gov (United States)

    Hartemann, Fred; Albert, Felicie; Anderson, Scott; Chu, Sam; Cross, Rick; Ebbers, Chris; Gibson, David; Messerly, Mike; Semenov, Vlad; Shverdin, Miro; Siders, Craig; McNabb, Dennis; Barty, Chris; Vlieks, Arnold; Tantawi, Sami

    2009-11-01

    A precision, tunable gamma-ray source driven by a compact, high-gradient X-band linac is currently under development at LLNL. High-brightness, relativistic electron bunches produced by the linac interact with a Joule-class, 10 ps laser pulse to generate tunable γ-rays in the 0.5-2.5 MeV photon energy range via Compton scattering. The source will be used to excite nuclear resonance fluorescence lines in various isotopes; applications include homeland security, stockpile science and surveillance, nuclear fuel assay, and waste imaging and assay. The source design, key parameters, and current status are presented.

  15. Measurement of neutron yield by 62 MeV proton beam on a thick Beryllium target

    CERN Document Server

    Alba, R; Boccaccio, P; Celentano, A; Colonna, N; Cosentino, G; Del Zoppo, A; Di Pietro, A; Esposito, J; Figuera, P; Finocchiaro, P; Kostyukov, A; Maiolino, C; Osipenko, M; Ricco, G; Ripani, M; Viberti, C M; Santonocito, D; Schillaci, M

    2012-01-01

    In the framework of research on IVth generation reactors and high intensity neutron sources a low-power prototype neutron amplifier was recently proposed by INFN. It is based on a low-energy, high current proton cyclotron, whose beam, impinging on a thick Beryllium converter, produces a fast neutron spectrum. The world database on the neutron yield from thick Beryllium target in the 70 MeV proton energy domain is rather scarce. The new measurement was performed at LNS, covering a wide angular range from 0 to 150 degrees and an almost complete neutron energy interval. In this contribution the preliminary data are discussed together with the proposed ADS facility.

  16. Neutron emission in 19F+181Ta reaction at 150 MeV

    International Nuclear Information System (INIS)

    In this work we concentrate on the HMS Model and the ALICE 2014 code. In fact one of the aims of the present study is to produce new data that will provide stringent test of the code. Neutron emission and light charged particle emission are useful tools for such a study. In the experiment we measured both neutron and charged particle spectra for a range of targets, and at three 19F beam energies. In this contribution we present the angle-dependent neutron spectra for 19F + 181Ta at beam energy of 150 MeV

  17. 'Cabinet-safe' study of 1-8 MeV electron accelerators

    CERN Document Server

    Wells, D P; Yoon, W Y; Harmon, F

    2001-01-01

    The development of 'cabinet-safe' accelerator technology for approx 1-8 MeV electron LINACs would remove the only major barrier to large-scale 'field' applications of these accelerators. These applications range from non-destructive evaluation and assay to radiolytic degradation of hazardous waste. All field applications require large forward dose and very little lateral dose. We investigated the origin, energy, and angular distribution of unwanted lateral radiation dose from two different electron LINACS at three energies. We report on the contributions of various beam parameters to unwanted radiation dose and propose methods to control key beam parameters that significantly contribute to these doses.

  18. Ion shaking in the 200 MeV XLS-ring

    International Nuclear Information System (INIS)

    Ions, trapped inside the beam's potential, can be removed by the clearing electrodes when the amplitude of the ion oscillation is increased by vertically shaking the ions. A similar experiment in the 200 MeV XLS ring is described. In the experiments, RF voltage was applied on a pair of vertical striplines. The frequency was scanned in the range of the ion (from H2 to CO2) bounce frequencies in the ring (1-10 MHz). The response of the beam size, vertical betatron tune and lifetime was studied. (author) 19 refs.; 4 figs

  19. M-shell electron capture and direct ionization of gold by 25-MeV carbon and 32-MeV oxygen ions

    International Nuclear Information System (INIS)

    M-shell x-ray production cross sections have been measured for thin solid targets of Au for 25 MeV 12C/sup q+/ (q = 4, 5, 6) and for 32 MeV 16O/sup q+/ (q = 5, 7, 8). The microscopic cross sections were determined from measurements made with targets ranging in thickness from 0.5 to 100 μg/cm2. For projectiles with one or two K-shell vacancies, the M-shell x-ray production cross sections are found to be enhanced over those by projectiles without a K-shell vacancy. The sum of direct ionization to the continuum (DI) and electron capture (EC) to the L, M, N ... shells and EC to the K-shell of the projectile have been extracted from the data. The results are compared to the predictions of first Born theories i.e. PWBA for DI and OBK of Nikolaev for EC and the ECPSSR approach that accounts for energy loss, Coulomb deflection and relativistic effects in the perturbed stationary state theory. 25 references, 3 figures, 1 table

  20. (γ,n) reaction in nuclei of the 12<=A<=238 interval in the intermediate energy region (300 MeV-1000MeV)

    International Nuclear Information System (INIS)

    The absolute cross section of the 12C(γ,n)11C, 19F(γ,n)18F, 23Na(γ,n)22Na, 31P(γ,n)30P, 52Cr(γ,n)51Cr, 55Mn(γ,n)54Mn, 59Co(γ,n)58Co, 75As(γ,n)74As, 103Rh(γn)102Rh, 127I(γ,n)126I, 197Au(γ,n)196Au and 238U(γ,n)237U reactions were determined, experimentally, in the energy range from 300 MeV to 1000 MeV, using Bremsstrahlung photons. The measured cross sections were compared with results estimated by Monte Carlo Method applied to intranuclear cascades initiated by phothons. A functional dependence between the average value of (γ,n) absolute cross section and the mass number, were established. The (γ,n) absolute cross sections from simple relations, which transparencies of complexe nuclei for mesons and nucleons photo produced were also determined. (M.C.K.)

  1. An analysis of 100 MeV F 8+ ion and 50 MeV Li 3+ ion irradiation effects on silicon NPN rf power transistors

    Science.gov (United States)

    Pushpa, N.; Praveen, K. C.; Gnana Prakash, A. P.; Prabhakara Rao, Y. P.; Tripati, Ambuj; Revannasiddaiah, D.

    2010-08-01

    The dc characteristics exhibited by NPN power transistors are studied systematically before and after irradiation by 100 MeV F 8+ ions and 50 MeV Li 3+ ions in the dose range of 100 krad to 100 Mrad. The transistor parameters such as excess base current (Δ IB= IBpost- IBpre), dc current gain ( hFE), transconductance ( gm), and collector-saturation current ( ICsat) were studied before and after irradiation. The damage factors ( k) for hFE were calculated for ion irradiated transistors using Messenger-Spratt relation. The base current ( IB) was found to increase significantly after ion irradiation and this in turn decreases the hFE of the transistors. The gm decreases significantly after ion irradiation. Moreover, the output characteristics of irradiated devices also show that the collector current ( IC) in the saturation region ( ICsat) decrease with increase in ion dose. The observed change in these characteristics may be due to the ion induced generation-recombination (G-R) centers in emitter-base (E-B) spacer oxide and the ion induced point defects and their complexes in the transistor structure.

  2. GAMMA-LIGHT: High-Energy Astrophysics above 10 MeV

    CERN Document Server

    Morselli, Aldo; Barbiellini, Guido; Bonvicini, Walter; Bulgarelli, Andrea; Cardillo, Martina; Chen, Andrew; Coppi, Paolo; Di Giorgio, Anna Maria; Donnarumma, Immacolata; Del Monte, Ettore; Fioretti, Valentina; Galli, Marcello; Giusti, Manuela; Ferrari, Attilio; Fuschino, Fabio; Giommi, Paolo; Giuliani, Andrea; Labanti, Claudio; Lipari, Paolo; Longo, Francesco; Marisaldi, Martino; Molinari, Sergio; Muñoz, Carlos; Neubert, Torsten; Orleanski, Piotr; Paredes, Josep M; Pérez-García, M Ángeles; Piano, Giovanni; Picozza, Piergiorgio; Pilia, Maura; Pittori, Carlotta; Pucella, Gianluca; Sabatini, Sabina; Striani, Edoardo; Tavani, Marco; Trois, Alessio; Vacchi, Andrea; Vercellone, Stefano; Verrecchia, Francesco; Vittorini, Valerio; Zdziarski, Andrzej

    2014-01-01

    High-energy phenomena in the cosmos, and in particular processes leading to the emission of gamma- rays in the energy range 10 MeV - 100 GeV, play a very special role in the understanding of our Universe. This energy range is indeed associated with non-thermal phenomena and challenging particle acceleration processes. The technology involved in detecting gamma-rays is challenging and drives our ability to develop improved instruments for a large variety of applications. GAMMA-LIGHT is a Small Mission which aims at an unprecedented advance of our knowledge in many sectors of astrophysical and Earth studies research. The Mission will open a new observational window in the low-energy gamma-ray range 10-50 MeV, and is configured to make substantial advances compared with the previous and current gamma-ray experiments (AGILE and Fermi). The improvement is based on an exquisite angular resolution achieved by GAMMA-LIGHT using state-of-the-art Silicon technology with innovative data acquisition. GAMMA-LIGHT will add...

  3. High resolution 12C(γ,p) experiments at Eγ ≅ 25-75 MeV

    International Nuclear Information System (INIS)

    Absolute differential cross sections for the 12C(γ,p)11B 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 11B. 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 Eγ=40-75 MeV. A reinterpretation of the states excited in11B 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,γ) in the centre-of-momentum system by detailed balance. The comparison with respect to missing momentum indicates an angular dependence in the (γ,p) reaction which is not present in the inverse (p,γ) reaction. Recent results from the MAX laboratory for the (γ,n) reaction are compared to the (γ,p) results. The mirror nuclei 11C and 11B have almost identical excitation energy spectra at Eγ=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 (γ,p) reaction. An extension of the spherical symmetric basis for the wave function is suggested for the states at E about 7 MeV in 11B. 108 refs, 83 figs

  4. 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...

  5. Photon activation analysis of the scraper in a 200-MeV electron accelerator using gamma-spectrometry depth profiling

    CERN Document Server

    Lijuan, He; Guobing, Yu; Guangyi, Ren; Zongjin, Duan

    2014-01-01

    For a high energy electron facility, the estimates of induced radioactivity in materials are of major importance to keep exposure to personnel and to the environment as low as reasonably achievable. In addition, an accurate prediction of induced radioactivity is also essential for the design, operation and decommissioning of a high energy electron linear accelerator. The research of induced radioactivity focuses on the photonuclear reaction, whose giant resonance response in the copper is ranging from 10 MeV to 28 MeV. The 200 MeV electron linac of NSRL is one of the earliest high-energy electron linear accelerators in P. R. China. The electrons are accelerated to 200 MeV by five acceleration tubes and collimated by the scrapers made of copper. At present, it is the first retired high-energy electron linear accelerator in domestic. Its decommissioning provides an efficient way for the induced radioactivity research of such accelerators, and is a matter of great significance to the accumulation of the induced ...

  6. Fusion with projectiles form carbon to argon at energies between 20A and 60A MeV

    International Nuclear Information System (INIS)

    A review of the linear momentum transfer is made, considering essentially heavy targets and two important parameters in the entrance channel: the projectile energy and its mass. Over a broad mass range, and for energies up to 30A MeV, the momentum transfer scales with the mass of the projectile. At 30A MeV, the most probable value of projectile momentum transferred to the fused system is 80%, and this represents roughly 180 MEV/c per projectile nucleon. At higher bombarding energies, the momentum distribution in the fused systems, as observed from binary fission events, seems to depend on the mass of the projectile. Further studies are still needed to understand this behaviour. Finally, the decay of highly excited (E* approximately 500-800 MeV) fused systems, with masses close to 270 amu, is studied from the characteristics of both fusion fragments and light charged particles. It is shown that thermal equilibrium is reached before fission, even for such high energy deposition. However, the decay sequence is sensitive to dynamical effects and does not depend only on available phase space

  7. Evaluation of d + 6,7Li data for deuteron incident energies up to 50 MeV

    International Nuclear Information System (INIS)

    A new evaluation of the nuclear data for a particle transport calculations was performed for d + 6,7Li interactions in the energy region from 4 to 50 MeV incident energy. Use was made of the available new optical model potential for d + Li interactions. For the description of a neutron emission a new optical model potential for n + 9Be was elaborated for the neutron energies from 0.1 to 22 MeV. Global optical model potentials were used for the neutrons above 22 MeV and for protons, tritons, He-3 and alphas - in the whole energy range. The following nuclear processes were accounted for: particle evaporation and preequilibrium emission, stripping of the proton from the deuteron and direct interactions of deuterons with lithium nuclei. GNASH and ECIS96 codes were applied for the first two process descriptions, the Serber model was utilised for stripping processes and the DWUCK4 code was used for direct reaction processes modelling. Total neutron emission spectra were calculated as a sum of the spectra in all these processes. A complete transport file was finally prepared in ENDF-6 format covering the deuteron incident energies up to 50 MeV. The newly evaluated data are in good agreement with experimental data for neutron emission spectra. The evaluated data files were successfully tested with a modified version of the MCNP computer code

  8. Excitation functions of the proton induced nuclear reactions on {sup nat}Zn up to 40 MeV

    Energy Technology Data Exchange (ETDEWEB)

    Uddin, M.S. [Department of Physics, Kyungpook National University, 1370 Sankyok-dong, Buk-gu, Daegu 702-701 (Korea, Republic of); Institute of Nuclear Science and Technology, Atomic Energy Research Establishment, Savar, GPO Box No. 3787, Dhaka-1000 (Bangladesh); Khandaker, M.U. [Department of Physics, Kyungpook National University, 1370 Sankyok-dong, Buk-gu, Daegu 702-701 (Korea, Republic of); Kim, K.S. [Department of Physics, Kyungpook National University, 1370 Sankyok-dong, Buk-gu, Daegu 702-701 (Korea, Republic of); Lee, Y.S. [Department of Physics, Kyungpook National University, 1370 Sankyok-dong, Buk-gu, Daegu 702-701 (Korea, Republic of); Kim, G.N. [Department of Physics, Kyungpook National University, 1370 Sankyok-dong, Buk-gu, Daegu 702-701 (Korea, Republic of)]. E-mail: gnkim@knu.ac.kr

    2007-05-15

    We measured the excitation functions of the {sup nat}Zn(p,xn){sup 66,67}Ga, {sup nat}Zn(p,pxn){sup 62,65,69m}Zn, and {sup nat}Zn(p,{alpha}xn){sup 61}Cu 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 {sup 66}Ga and {sup 67}Ga radionuclides at 22 MeV support our deduced yields. The optimum formation of the {sup 66}Ga and {sup 61}Cu 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 {sup 65}Zn are suitable for thin layer activation analysis.

  9. Capacitance and conductance studies on silicon solar cells subjected to 8 MeV electron irradiations

    International Nuclear Information System (INIS)

    The space grade silicon solar cells were irradiated with 8 MeV electrons with doses ranging from 5–100 k Gy. Capacitance and conductance measurements were carried out in order to investigate the anomalous degradation of the cells in the radiation harsh environments and the results are presented in this paper. Detailed and systematic analysis of the frequency-dependent capacitance and conductance measurements were performed to extract the information about the interface trap states. The small increase in density of interface states was observed from the conductance–frequency measurements. The reduction in carrier concentration upon electron irradiation is due to the trapping of charge carriers by the radiation induced trap centres. The Drive Level Capacitance Profiling (DLCP) technique has been applied to study the properties of defects in silicon solar cells. A small variation in responding state densities with measuring frequency was observed and the defect densities are in the range 1015 –1016 cm−3. - Highlights: • Space grade Si solar cells were subjected to 8 MeV electron radiation. • Capacitance and conductance measurements were done before and after irradiation. • Density of interface states and the interface trap time constant is found to increase with increasing electron dose. • The displacement damage formed due to electron is not uniform throughout the active region of c-Si solar cell

  10. Femtosecond Time-resolved MeV Electron Diffraction

    CERN Document Server

    Zhu, Pengfei; Cao, J; Geck, J; Hidaka, Y; Kraus, R; Pjerov, S; Shen, Y; Tobey, R I; Zhu, Y; Hill, J P; Wang, X J

    2013-01-01

    We report the experimental demonstration of electron diffraction with 130 femtosecond time resolution using bench-top MeV electron beams. High-quality, single-shot electron diffraction patterns for both polycrystalline aluminium and single-crystal 1T-TaS_{2} are obtained utilizing a 5 femto-Coulomb (~3x10^{4} electrons) pulse of electrons at 2.8 MeV. The timing jitter between the pump laser and probe electron beam was found to be ~ 100 fs. The time resolution is demonstrated by observing the evolution of Bragg and superlattice peaks of 1T-TaS_{2} following an optical pump. Our experiemntal results demonstrate the feasibility of ultimately realizing 40 fs time-resolved electron diffraction.

  11. Initial Test of the PEFP 20MeV DTL

    CERN Document Server

    Kim, Han-Sung; Han, Sang-Hyo; Hwang, Yong-Suk; Jang, Ji-Ho; Kim, Yong-Hwan; Kwon, Hyeok-Jung; Park, Mi-Young; Tae Seol, Kyung

    2005-01-01

    A conventional 20MeV drift tube linac (DTL) for the Proton Engineering Frontier Project (PEFP) has been developed as a low energy section of 100MeV accelerator. The machine consists of four tanks with 152 cells supplied with 900kW RF power from 350MHz klystron through the ridge-loaded waveguide coupler. We assembled the fabricated accelerator components and aligned each part with care. We have also prepared the subsystems for the test of the DTL such as RF power delivery system, high voltage DC power supply, vacuum system, cooling system, measurements and control system and so on. The detailed description of the initial test setup and preliminary test results will be given in this paper.

  12. Stopping powers of havar for 0.63 5.9 MeV protons and 2.6 24 MeV alpha particles

    Science.gov (United States)

    Porter, L. E.; Trzaska, W. H.; Räisänen, J.; Lyapin, V.

    2004-11-01

    A transmission experiment utilizing thin foil targets has been conducted in order to establish the stopping powers of the cobalt-base alloy, havar, for 0.6-5.9 MeV protons and 2.6-24 MeV alpha particles. The basic technique of the novel experimental method used was to record both the projectile energy and the time of flight while alternating measurements with and without the target in place. The uncertainties of the proton and alpha particle data sets ranged from 1.4 to 2.3% and 1.1 to 1.5%, respectively. Modified Bethe-Bloch theory was applied to the measurements in order to ascertain values of the target mean excitation energy (I) and Barkas-effect parameter (b) for each projectile. The extracted values were I = 304.3 ± 2.4 eV and b = 1.37 ± 0.04 for the case of protons, and I = 306.3 ± 2.3 eV and b = 1.47 ± 0.03 for the case of alpha particles. The I-values are somewhat higher than the additivity-based expectation of 295.7 eV, whereas the b-values are clearly consistent with the expected range of 1.4 ± 0.1. The parameter values extracted from the measurements are appraised for compatibility with recently observed trends in values of I and of b with increasing projectile atomic number.

  13. 6 MeV storage ring dedicated to hard X-ray imaging and far-infrared spectroscopy

    Indian Academy of Sciences (India)

    M M Haque; A Moon; T Hirai; H Yamada

    2011-02-01

    The tabletop storage ring, 6 MeV MIRRORCLE, is dedicated to hard X-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 submillimetre range FIR rays. Bremsstrahlung is the mechanism for the hard X-ray generation. Images produced with 11 × geometrical magnification display a sharply enhanced edge effect when generated using a 25 mm rod electron target. Bright far-infrared is generated in the same way using a conventional synchrotron light source, but with MIRRORCLE the spectral flux is found to be ∼ 1000 times greater than that of a standard thermal source. Partially coherent enhancement is observed in the case of FIR output.

  14. Production of actinium, thorium and radium isotopes from natural thorium irradiated with protons up to 141 MeV

    Energy Technology Data Exchange (ETDEWEB)

    Ermolaev, S.V.; Zhuikov, B.L.; Kokhanyuk, V.M.; Matushko, V.L. [Russian Academy of Sciences, Moscow (Russian Federation). Inst. of Nuclear Research; Kalmykov, S.N. [Lomonosov Moscow State Univ., Moscow (Russian Federation). Chemistry Dept.; Aliev, R.A. [Lomonosov Moscow State Univ., Moscow (Russian Federation). Skobeltsyn Inst. of Nuclear Physics; Tananaev, I.G.; Myasoedov, B.F. [Russian Academy of Sciences, Moscow (Russian Federation). A.N. Frumkin Inst. of Physical Chemistry and Electrochemistry

    2012-07-01

    Cross sections of {sup 225}Ac, {sup 227}Ac, {sup 227}Th and {sup 228}Th in thorium-232 targets irradiated with protons in the energy range 21-141 MeV have been measured. Based on these data, production yields of {sup 225}Ac and {sup 223}Ra in thick thorium targets have been calculated. It is possible to produce in proton energy range 60-140 MeV about 96 GBq (2.6 Ci) {sup 225}Ac per 10-d irradiation with 100 {mu}A proton beam current and 10-d decay, and much higher amount of {sup 223}Ra. The impurities of {sup 227}Ac and {sup 224}Ra are important and need to be assessed for further medical applications. (orig.)

  15. Calculation of the neutron induced fission cross-section of 233Pa up to 20 MeV

    International Nuclear Information System (INIS)

    Since very recently, direct measurements of the 233Pa(n,f) cross-section are available in the energy range from 1.0 to 8.5 MeV. This has stimulated a new, self-consistent, neutron cross-section evaluation for the n+233Pa system, in the incident neutron energy range 0.01-20 MeV. Since higher fission chances are involved also the lighter Pa-isotopes had to be re-evaluated in a consistent manner. The results are quite different compared to earlier evaluation attempts. Since 233Pa is a key isotope in the thorium based fuel cycle the quality of its reaction cross-sections is important for the modeling of future advanced fuel and reactor concepts. The present status of the evaluated libraries is that they differ by a factor of two in the absolute fission cross-section and also in the threshold energy value

  16. RADIATION DAMAGE TO BSCCO-2223 FROM 50 MEV PROTONS

    Energy Technology Data Exchange (ETDEWEB)

    Zeller, A.F.; Ronningen, R.M.; Godeke, Arno; Heibronn, L.H; McMahan-Norris, P.; Gupta, R.

    2007-11-01

    The use of HTS materials in high radiation environments requires that the superconducting properties remain constant up to a radiation high dose. BSCCO-2223 samples from two manufacturers were irradiated with 50 MeV protons at fluences of up to 5 x 10{sup 17} protons/cm{sup 2}. The samples lost approximately 75% of their pre-irradiation I{sub c}. This compares with Nb{sub 3}Sn, which loses about 50% at the same displacements per atom.

  17. RADIATION DAMAGE TO BSCCO-2223 FROM 50 MEV PROTONS

    Energy Technology Data Exchange (ETDEWEB)

    Zeller, A.F.; Ronningen, R.M.; Godeke, A.; Heilbronn, L.H.; McMahan-Norris, P.; Gupta, R.

    2007-11-27

    The use of HTS materials in high radiation environmentsrequires that the superconducting properties remain constant up to aradiation high dose. BSCCO-2223 samples from two manufacturers wereirradiated with 50 MeV protons at fluences of up to 5 x 1017 protons/cm2.The samples lost approximately 75 percent of their pre-irradiation Ic.This compares with Nb3Sn, which loses about 50 percent at the samedisplacements per atom.

  18. True absorption and scattering of 50 MeV pions

    International Nuclear Information System (INIS)

    The inclusive pion inelastic scattering and true absorption cross sections at 50 MeV were measured for π+ on natural Li, C, Fe, Nb, Bi and for π- on C, Fe, Bi. The results show that π- cross sections are much larger than π+, the difference being significantly larger than expected from a simple Coulomb calculation. In particular, in 12C the absorption of negative pions is about twice that of positive pions

  19. 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.

  20. 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)

  1. Neutron capture cross section of $^{232}Th$ measured at the nTOF facility at CERN in the unresolved resonance region up to 1 MeV

    CERN Document Server

    Aerts, G; Alvarez, H; Alvarez-Velarde, F; Andriamonje, Samuel A; Andrzejewski, J; Assimakopoulos, P A; Audouin, L; Badurek, G; Baumann, P; Becvar, F; Berthoumieux, E; Calviño, F; Cano-Ott, D; Capote, R; Carillo de Albornoz, A; Cennini, P; Chepel, V Yu; Chiaveri, Enrico; Colonna, N; Cortés, G; Couture, A; Cox, J; Dahlfors, M; David, S; Dillman, I; Dolfini, R; Domingo-Pardo, C; Dridi, W; Durán, I; Eleftheriadis, C; Embid-Segura, M; Ferrant, L; Ferrari, A; Ferreira-Marques, R; Fitzpatrick, L; Frais-Kölbl, H; Fujii, K; Furman, W; Gonçalves, I; González-Romero, E M; Goverdovski, A; Gramegna, F; Griesmayer, E; Guerrero, C; Gunsing, F; Haas, B; Haight, R; Heil, M; Herrera-Martínez, A; Igashira, M; Isaev, S; Jericha, E; Käppeler, F K; Kadi, Y; Karadimos, D; Karamanis, D; Kerveno, M; Ketlerov, V; Köhler, P; Konovalov, V; Kossionides, E; Krticka, M; Lamboudis, C; Leeb, H; Lindote, A; Lopes, I; Lozano, M; Lukic, S; Marganiec, J; Marques, L; Marrone, S; Mastinu, P; Mengoni, A; Milazzo, P M; Moreau, C; Mosconi, M; Neves, F; Oberhummer, Heinz; O'Brien, S; Oshima, M; 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; Pretel, C; Quesada, J; Rauscher, T; Reifarth, R; Rosetti, M; Rubbia, Carlo; Rudolf, G; Rullhusen, P; Salgado, J; Sarchiapone, L; Savvidis, I; Stéphan, C; Taliente, G; Taín, J L; Tassan-Got, L; Tavora, L; Terlizzi, R; Vannini, G; Vaz, P; Ventura, A; Villamarín, D; Vincente, M C; Vlachoudis, V; Vlastou, R; Voss, F; Walter, S; Wendler, H; Wiescher, M; Wisshak, K

    2006-01-01

    We have measured the neutron capture reaction yield of /sup 232energy range from 1 eV to 1 MeV. The average capture cross section has been extracted in the energy range from 4 keV up to 1 MeV with an overall accuracy better than 4%. An independent IAEA evaluation shows good agreement with the data. The average cross section has been expressed in terms of average resonance parameters using the partial waves script l=0,1, and 2.

  2. Scattering of MeV neutrons from elemental iron

    International Nuclear Information System (INIS)

    Neutron elastic- and inelastic-scattering cross sections of elemental iron are measured from 1.5 to 4.0 MeV with incident-neutron resolutions of < or approx. = to 50 keV and at incident-neutron energy intervals of < or approx. = to 50 keV. Cross sections for the excitation of observed levels at 0.853, 1.389, 2.097, 2.579, 2.677, 2.974 and 3.152 MeV are determined. The observed elastic- and inelastic-scattering angular distributions fluctuate strongly with incident energy. The experimental results are averaged over broad energy intervals and interpreted in terms of spherical optical-statistical and coupled-channels models including consideration of direct-vibrational excitations. The importance of a comprehensive data base in such energy-averaged interpretations and of the direct-vibrational excitations is stressed. The present measured and calculated results, combined with those reported in the literature, are used to formulate an evaluated scattered-neutron data file in the ENDF format extending from 1.0 to 4.0 MeV. 41 references

  3. MeV ion processing applications for industry

    International Nuclear Information System (INIS)

    Ions beams with MeV energies produce a variety of interactions with matter, broadly classified as either electronic or nuclear. These interactions in turn lead to changes in the properties of the matter which may be beneficial or detrimental. In high technology industry, use is increasingly made of ion beam technologies to process novel materials. Typical applications include high energy implantation, in which the deposition of a specific element at depth within the structure of material is the required objective, and irradiation modification, in which the balance between the beneficial and the detrimental effects of the fast ion interactions is exploited. The basic principles behind MeV ion processing are described. Broad areas of application in industrial materials include effects in ion beam analysis, Thin Layer Activation for wear and corrosion measurement, carrier lifetime control in electronic devices, and the simulation of radiation damage effects in, for example, solar cells for spacecraft. New development areas are described in which subtle but potentially significant changes in the chemistry of surfaces and interfaces may be generated by exposure to MeV ion beams. (orig.)

  4. Measurement of the Z31 contribution to the stopping power using MeV protons and antiprotons: The Barkas effect

    Science.gov (United States)

    Andersen, L. H.; Hvelplund, P.; Knudsen, H.; Möller, S. P.; Pedersen, J. O. P.; Uggerhöj, E.; Elsener, K.; Morenzoni, E.

    1989-04-01

    The stopping power for antiprotons has been measured for the first time. The antiproton stopping power of silicon is found to be 3%-19% lower than for equivelocity protons over the energy range 3.01 to 0.538 MeV. The ``Z31 contribution'' to the stopping power (the Barkas effect) is deduced by comparing the stopping power for protons and antiprotons.

  5. Calculated proton-induced thick-target neutron and radionuclide yields for Ep ≤ 100 MeV

    International Nuclear Information System (INIS)

    Earlier proton-induced thick-target yield calculations have been extended in proton energy range and to additional target elements, using the proton stopping cross section data of Anderson and Ziegler and cross sections modeled with the GNASH code. The targets now described include Be, C, O, Ne, Al, Si, Fe, Co, Ni, Cu, W, Pb and Bi. Thick-target yields are presented for these thirteen targets, with most extending to 100 MeV. 13 refs., 3 figs., 13 tabs

  6. 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.

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

    Institute of Scientific and Technical Information of China (English)

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

    2012-01-01

    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 (C1) 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 (△(1/β)) of 3DD155 transistors irradiated respectively by 25-MeV C,40-MeV Si,and 40-MeV C1 ions each present a nonlinear behaviour at a low fluence and a linear response at a high fluence.The △(1/β) of 3DDl55 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 C1 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.

  8. The dosimetry of 3 MeV and 14 MeV neutrons with the ferrous sulphate solution

    International Nuclear Information System (INIS)

    The aim of the present work is to determine the G value of a standard ferrous sulphate solution for neutrons with mean energies of 3 MeV and 14 MeV. The number of the transformed Fe ions is evaluated by means of a spectrophotometrical procedure and the absorbed energy is determined by applying the ionometrical method. Especial attention is payed to the calculation of the mean total dose in the irradiated sample taking radiation attenuation into account. For this purpose the spatial distribution of absorbed energy within the probe is determined. Further, it is investigated how the fraction of the γ component in the total absorbed dose varies in the sample, in order to evaluate its mean value, which is needed for the final determination of the G value for the neutron component. (orig.)

  9. Neutron-neutron quasifree scattering in nd breakup at 10 MeV

    Science.gov (United States)

    Malone, R. C.; Crowe, B.; Crowell, A. S.; Cumberbatch, L. C.; Esterline, J. H.; Fallin, B. A.; Friesen, F. Q. L.; Han, Z.; Howell, C. R.; Markoff, D.; Ticehurst, D.; Tornow, W.; Witała, H.

    2016-03-01

    The neutron-deuteron (nd) breakup reaction provides a rich environment for testing theoretical models of the neutron-neutron (nn) interaction. Current theoretical predictions based on rigorous ab-initio calculations agree well with most experimental data for this system, but there remain a few notable discrepancies. The cross section for nn quasifree (QFS) scattering is one such anomaly. Two recent experiments reported cross sections for this particular nd breakup configuration that exceed theoretical calculations by almost 20% at incident neutron energies of 26 and 25 MeV [1, 2]. The theoretical values can be brought into agreement with these results by increasing the strength of the 1S0 nn potential matrix element by roughly 10%. However, this modification of the nn effective range parameter and/or the 1S0 scattering length causes substantial charge-symmetry breaking in the nucleon-nucleon force and suggests the possibility of a weakly bound di-neutron state [3]. We are conducting new measurements of the cross section for nn QFS in nd breakup. The measurements are performed at incident neutron beam energies below 20 MeV. The neutron beam is produced via the 2H(d, n)3He reaction. The target is a deuterated plastic cylinder. Our measurements utilize time-of-flight techniques with a pulsed neutron beam and detection of the two emitted neutrons in coincidence. A description of our initial measurements at 10 MeV for a single scattering angle will be presented along with preliminary results. Also, plans for measurements at other energies with broad angular coverage will be discussed.

  10. Large scale silver nanowires network fabricated by MeV hydrogen (H+) ion beam irradiation

    Science.gov (United States)

    Honey, S.; Naseem, S.; Ishaq, A.; Maaza, M.; Bhatti, M. T.; Wan, D.

    2016-04-01

    A random two-dimensional large scale nano-network of silver nanowires (Ag-NWs) is fabricated by MeV hydrogen (H+) ion beam irradiation. Ag-NWs are irradiated under H+ ion beam at different ion fluences at room temperature. The Ag-NW network is fabricated by H+ ion beam-induced welding of Ag-NWs at intersecting positions. H+ ion beam induced welding is confirmed by transmission electron microscopy (TEM) and scanning electron microscopy (SEM). Moreover, the structure of Ag NWs remains stable under H+ ion beam, and networks are optically transparent. Morphology also remains stable under H+ ion beam irradiation. No slicings or cuttings of Ag-NWs are observed under MeV H+ ion beam irradiation. The results exhibit that the formation of Ag-NW network proceeds through three steps: ion beam induced thermal spikes lead to the local heating of Ag-NWs, the formation of simple junctions on small scale, and the formation of a large scale network. This observation is useful for using Ag-NWs based devices in upper space where protons are abandoned in an energy range from MeV to GeV. This high-quality Ag-NW network can also be used as a transparent electrode for optoelectronics devices. Project supported by the National Research Foundation of South Africa (NRF), the French Centre National pour la Recherche Scientifique, iThemba-LABS, the UNESCO-UNISA Africa Chair in Nanosciences & Nanotechnology, the Third World Academy of Science (TWAS), Organization of Women in Science for the Developing World (OWSDW), the Abdus Salam ICTP via the Nanosciences African Network (NANOAFNET), and the Higher Education Commission (HEC) of Pakistan.

  11. 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....

  12. 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...

  13. Low-energy theorems for nucleon-nucleon scattering at Mπ=450 MeV

    Science.gov (United States)

    Baru, V.; Epelbaum, E.; Filin, A. A.

    2016-07-01

    We apply the low-energy theorems to analyze the recent lattice QCD results for the two-nucleon system at a pion mass of Mπ≃450 MeV obtained by the NPLQCD Collaboration. We find that the binding energies of the deuteron and dineutron are inconsistent with the low-energy behavior of the corresponding phase shifts within the quoted uncertainties and vice versa. Using the binding energies of the deuteron and dineutron as input, we employ the low-energy theorems to predict the phase shifts and extract the scattering length and the effective range in the S31 and S10 channels. Our results for these quantities are consistent with those obtained by the NPLQCD Collaboration from effective field theory analyses but are in conflict with their determination based on the effective-range approximation.

  14. Neutrino Interaction Calculations from MeV to GeV Region

    CERN Document Server

    Amaro, J E; Valverde, M; Vicente-Vacas, M J

    2008-01-01

    The Quasi-Elastic (QE) contribution of the nuclear inclusive electron model developed in Nucl. Phys. A627 543 (1997) is extended to the study of neutrino/antineutrino Charged Current (CC) and Neutral Current (NC) induced nuclear reactions at intermediate energies. Long range nuclear (RPA) correlations, Final State Interaction (FSI) and Coulomb corrections are included within the model. RPA correlations are shown to play a crucial role in the whole range (100--500 MeV) of studied neutrino energies. Results for inclusive muon capture for different nuclei through the Periodic Table are also discussed. In addition, and by means of a Monte Carlo cascade method to account for the rescattering of the outgoing nucleon, we also study the CC and NC inclusive one nucleon knockout reactions off nuclei.

  15. Investigation of gas stripping at 4.1 MeV for high mass negative ions

    International Nuclear Information System (INIS)

    We have used a tandem accelerator to measure charge state distributions at 4.1 MeV for negative ions ranging from carbon to uranium oxide passing through the gases helium, argon and xenon. The gas density was varied over a wide range to observe the onset of equilibrium stripping conditions. Using a 12° electrostatic deflector after the accelerator, charge states from 1+ to 8+ have been measured. For carbon, the charge state is seen to strip progressively from a low charge of around 1+ towards equilibrium with increasing gas thickness. However, for all the other ions, there is a high probability of multiple electron loss in single collisions with the gas, leading to mean charge states greater than 2 even at very low gas stripper pressure. This effect is observed to be gas-independent.

  16. Capacitance and conductance studies on silicon solar cells subjected to 8 MeV electron irradiations

    Science.gov (United States)

    Sathyanarayana Bhat, P.; Rao, Asha; Sanjeev, Ganesh; Usha, G.; Priya, G. Krishna; Sankaran, M.; Puthanveettil, Suresh E.

    2015-06-01

    The space grade silicon solar cells were irradiated with 8 MeV electrons with doses ranging from 5-100 k Gy. Capacitance and conductance measurements were carried out in order to investigate the anomalous degradation of the cells in the radiation harsh environments and the results are presented in this paper. Detailed and systematic analysis of the frequency-dependent capacitance and conductance measurements were performed to extract the information about the interface trap states. The small increase in density of interface states was observed from the conductance-frequency measurements. The reduction in carrier concentration upon electron irradiation is due to the trapping of charge carriers by the radiation induced trap centres. The Drive Level Capacitance Profiling (DLCP) technique has been applied to study the properties of defects in silicon solar cells. A small variation in responding state densities with measuring frequency was observed and the defect densities are in the range 1015 -1016 cm-3.

  17. Study of imaging plate detector sensitivity to 5-18 MeV electrons

    Energy Technology Data Exchange (ETDEWEB)

    Boutoux, G., E-mail: boutoux@celia.u-bordeaux1.fr; Rabhi, N.; Batani, D.; Ducret, J.-E. [Univ. de Bordeaux, CNRS, CEA, CELIA (Centre Lasers Intenses et Applications), UMR 5107, F-33405 Talence (France); Binet, A.; Nègre, J.-P.; Reverdin, C.; Thfoin, I. [CEA DAM DIF, F-91297 Arpajon (France); Jakubowska, K. [Institute of Plasma Physics and Laser Microfusion, Hery Street 23, 01-497 Warsaw (Poland)

    2015-11-15

    Imaging plates (IPs) are commonly used as passive detectors in laser-plasma experiments. We calibrated at the ELSA electron beam facility (CEA DIF) the five different available types of IPs (namely, MS-SR-TR-MP-ND) to electrons from 5 to 18 MeV. In the context of diagnostic development for the PETawatt Aquitaine Laser (PETAL), we investigated the use of stacks of IP in order to increase the detection efficiency and get detection response independent from the neighboring materials such as X-ray shielding and detector supports. We also measured fading functions in the time range from a few minutes up to a few days. Finally, our results are systematically compared to GEANT4 simulations in order to provide a complete study of the IP response to electrons over the energy range relevant for PETAL experiments.

  18. Temperature Dependence of the Primary Species Yields of Liquid Water Radiolysis by 0.8-MeV Fast Neutrons

    Directory of Open Access Journals (Sweden)

    S.L. Butarbutar

    2016-04-01

    Full Text Available The yields of species such as e-aq, H•, •OH, H2 and H2O2, formed from the radiolysis of neutral liquid water by the incidence of 0.8-MeV neutrons at temperatures between 25 and 350°C, were calculated by using Monte Carlo simulations. The slowing down of these neutrons through elastic scattering produced recoil protons elastically of ~0.5057, 0.186, and 0.0684 MeV which had linear energy transfers (LETs of ~40, 67 and 76 keV/µm, respectively, at 25°C. The effects of neutron radiation can be predicted based on the contribution of those first three recoil protons by neglecting the radiation effects due to oxygen ion recoils. Then, the fast neutron yields could be estimated by summing the yields of contributing protons after corresponding weightings were used according to their energy. In this work, yields were calculated at 10-7 and 10-6 s after incidence of neutron radiation in water at the aforementioned temperature range. Overall, there is a reasonably good agreement between our calculated and existing experimental G-values for the entire temperature range. However, we proposed an hypothesis that the not very significant difference between experimental data and our calculated data is due to the different measuring time used in obtaining the experimental data as compared to the ones used in our calculation. Our computed yields for 0.8-MeV fast neutron radiation show an essentially similar temperature dependences over the range of temperature studied with 2-MeV fast neutron and low-LET radiation, but with lower values for yields of free radicals and higher values for molecular yields.

  19. Stopping powers of polycarbonate for 0.36-5.94-MeV protons and 1.0-24.0-MeV α particles

    Science.gov (United States)

    Räisänen, J.; Trzaska, W. H.; Alanko, T.; Lyapin, V.; Porter, L. E.

    2003-08-01

    The stopping powers of polycarbonate for protons of energy 0.6-5.9 MeV and α particles of energy 2.0-24.0 MeV have been measured in a transmission experiment employing thin-foil targets. The essence of the novel experimental method employed in the present measurements is to record both projectile energy and time of flight while constantly alternating measurements with and without the target foil in place. The accuracies of the proton data and α-particle data range from 2.0% to 3.0% and 2.2% to 2.7%, respectively. All of the resulting measurements were analyzed in terms of modified Bethe-Bloch theory in order to extract values of the target mean excitation energy (I) and Barkas-effect parameter (b). The composite results for the two projectiles are that I=71.52 eV and b=1.13, the former value lying about one standard deviation below the additivity value and the latter value lying about one standard deviation below the expected value of 1.4±0.1. Previous measurements of the stopping power of polycarbonate for 7Li ions were analyzed by the same method, but with the inclusion of an effective charge parameter (λ). The proton and α-particle data, with a few lower-energy points included, were analyzed for a three-parameter fit, also. Results for the three projectiles studied indicate both internal consistency and agreement with expectations based on modified Bethe-Bloch theory.

  20. The 17 MeV Anomaly in Beryllium Decays and $U(1)$ Portal to Dark Matter

    CERN Document Server

    Chen, Chian-Shu; Lin, Yen-Hsun; Xu, Fanrong

    2016-01-01

    The experiment of Krasznahorkay \\textit{et al} observed the transition of a $\\rm{^{8}Be}$ excited state to its ground state and accompanied by an emission of $e^{+}e^{-}$ pair with 17 MeV invariant mass. This 6.8$\\sigma$ anomaly can be fitted by a new light gauge boson. We consider the new particle as a $U(1)$ gauge boson, $Z'$, which plays as a portal linking dark sector and visible sector. In particular, we study the new $U(1)$ gauge symmetry as a hidden or non-hidden group separately. The generic hidden $U(1)$ model, referred to as dark $Z$ model, is excluded by imposing various experimental constraints. On the other hand, a non-hidden $Z'$ is allowed due to additional interactions between $Z'$ and Standard Model fermions. We also study the implication of the dark matter direct search on such a scenario. We found the search for the DM-nucleon scattering excludes the range of DM mass above 500 MeV. However, the DM-electron scattering for MeV-scale DM is still allowed by current constraints for non-hidden $U...

  1. 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 ...

  2. Production of α-particle emitting 211At using 45 MeV α-beam

    Science.gov (United States)

    Kim, Gyehong; Chun, Kwonsoo; Park, Sung Ho; Kim, Byungil

    2014-06-01

    Among the α-particle emitting radionuclides, 211At is considered to be a promising radionuclide for targeted cancer therapy due to its decay properties. The range of alpha particles produced by the decay of 211At are less than 70 µm in water with a linear energy transfer between 100 and 130 keV µm-1, which are about the maximum relative biological effectiveness for heavy ions. It is important to note that at the present time, only a few of cyclotrons routinely produce 211At. The direct production method is based on the nuclear reactions 209Bi(α,2n)211At. Production of the radionuclide 211At was carried out using the MC-50 cyclotron at the Korea Institute of Radiological and Medical Sciences (KIRAMS). To ensure high beam current, the α-beam was extracted with an initial energy of 45 MeV, which was degraded to obtain the appropriate α-beam energy. The calculations of beam energy degradation were performed utilizing the MCNPX. Alumina-baked targets were prepared by heating the bismuth metal powder onto a circular cavity in a furnace. When using an Eα, av of 29.17 MeV, the very small contribution of 210At confirms the right choice of the irradiation energy to obtain a pure production of 211At isotope.

  3. LET spectrometry of 14 MeV (D–T) neutrons using CR-39 track detectors

    Energy Technology Data Exchange (ETDEWEB)

    Sahoo, G.S. [Accelerator Radiation Safety Section, Health Physics Division, Bhabha Atomic Research Center, Mumbai 400085 (India); Tripathy, S.P., E-mail: tripathy@barc.gov.in [Accelerator Radiation Safety Section, Health Physics Division, Bhabha Atomic Research Center, Mumbai 400085 (India); Sunil, C.; Sarkar, P.K. [Accelerator Radiation Safety Section, Health Physics Division, Bhabha Atomic Research Center, Mumbai 400085 (India)

    2013-04-21

    Linear energy transfer (LET) spectrum in water in the range of 12 keV/μm to 382 keV/μm due to 14 MeV (D–T) neutrons is estimated using the track size parameters in two different types of CR-39 track detectors, viz. Intercast (1.5 mm) and Pershore (0.5 mm). Another set of CR-39s (Intercast) combined with 1 mm polyethylene (PE) radiators is exposed to study the effect of enhanced recoils on the LET spectrum. The detection efficiencies for all these cases and the enhancement ratio due to PE radiator are determined. Using this LET spectrum, the microdosimetric spectra of absorbed doses and dose equivalents are estimated based on the Q–L conversion factors as given in ICRP 60. The shape of the LET spectra are found to be similar in all the cases, however, the dose equivalents obtained with the CR-39+PE radiator is about 20% more than the other detectors without PE. The ratios of dose equivalents obtained from LET spectra (H{sub LET}) and the ambient dose equivalent (H*(10)) obtained from fluence-to-dose equivalent conversion factors (ICRP 74) for 14 MeV neutrons are used to estimate the dose response of the detectors. H*(10) is also measured using a neutron rem meter, the response of which is found to be about 23% less than the actual dose.

  4. Neutron induced light-ion production from Iron and Bismuth at 175 MeV

    Science.gov (United States)

    Bevilacqua, R.; Pomp, S.; Simutkin, V.; Tippawan, U.; Andersson, P.; Blomgren, J.; Österlund, M.; Hayashi, M.; Hirayama, S.; Naito, Y.; Watanabe, Y.; Tesinsky, M.; Lecolley, F.-R.; Marie, N.; Hjalmarsson, A.; Prokofiev, A.; Kolozhvari, A.

    2010-03-01

    We have measured light-ion (p, d, t, 3He and α) production in the interaction of 175 MeV neutrons with iron and bismuth, using the MEDLEY setup. A large set of measurements at 96 MeV has been recently completed and published, and now higher energy region is under investigation. MEDLEY is a conventional spectrometer system that allows low-energy thresholds and offers measurements over a wide angular range. The system consists of eight telescopes, each of them composed of two silicon surface barrier detectors, to perform particle identification, and a CsI(Tl) scintillator to fully measure the kinetic energy of the produced light-ions. The telescopes are placed at angles from 20° to 160°, in steps of 20°. Measurements have been performed at The Svedberg Laboratory, Uppsala (Sweden), where a quasi mono-energetic neutron beam is available and well characterized. Time of flight techniques are used to select light-ion events induced by neutrons in the main peak of the source neutron spectrum. We report preliminary double differential cross sections for production of protons, deuterons and tritons in comparison with model calculations using TALYS-1.0 code.

  5. 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.

  6. 14-MeV neutron streaming through shield gaps

    International Nuclear Information System (INIS)

    Monte Carlo calculations have been performed to determine the neutron streaming through straight and single-bend gaps for three different shield thicknesses. A uniform plane source emitting 14-MeV neutrons with a cosine angular distribution was used in the analyses. The results obtained are discussed in terms of how they might be used in the early stages of a shield design to obtain approximate solutions to design questions. These results have direct implications regarding neutron-streaming problems that will be encountered in the shielding analyses of tokamak fusion reactors which are constructed from pie-shaped shield/vacuum chamber segments

  7. An intense 14 MeV neutron source

    Energy Technology Data Exchange (ETDEWEB)

    Su Tongling; Sun Biehe; Yang Baotai; Piao Yubo; Shui Yongqing; Chen Kefan; Wang Xuezhi; Yang Cheng; Niu Zhanqi; Liu Yanton; Pan Minshen; Hong Zhongti; Chen Qin (Lanzhou Univ., GS (China). Inst. of Nuclear Research)

    1990-02-15

    A 3x10{sup 12} n/s source of 14 MeV neutrons is described in this paper. The neutrons are produced by the T(d,n){sup 4}He reaction under a 30 mA, 300 keV deuteron beam bombarding a water-cooled, rotating titanium-tritide target. The size of the beam spot on the target is 1.8 cm, and at the distance of closest approach to the source a neutron flux of 5x10{sup 11} n/cm{sup 2} s is obtained. (orig.).

  8. Polarization Observables in Deuteron Photodisintegration below 360 MeV

    CERN Document Server

    Glister, J; Lee, B W; Gilman, R; Sarty, A J; Strauch, S; Higinbotham, D W; Piasetzky, E; Allada, K; Armstrong, W; Arrington, J; Beck, A; Benmokhtar, F; Berman, B L; Boeglin, W; Brash, E; Camsonne, A; Calarco, J; Chen, J P; Choi, Seonho; Chudakov, E; Coman, L; Craver, B; Cusanno, F; Dumas, J; Dutta, C; Feuerbach, R; Freyberger, A; Frullani, S; Garibaldi, F; Hansen, J -0; Holmstrom, T; Hyde, C E; Ibrahim, H; Ilieva, Y; de Jager, C W; Jiang, X; Jones, M K; Kang, H; Kelleher, A; Khrosinkova, E; Kuchina, E; Kumbartzki, G; LeRose, J J; Lindgren, R; Markowitz, P; Beck, S May-Tal; McCullough, E; Meekins, D; Meziane, M; Meziani, Z -E; Michaels, R; Moffit, B; Norum, B E; Oh, Y; Olson, M; Paolone, M; Paschke, K; Perdrisat, C F; Potokar, M; Pomatsalyuk, R; Pomerantz, I; Puckett, A; Punjabi, V; Qian, X; Qiang, Y; Ransome, R; Reyhan, M; Roche, J; Rousseau, Y; Saha, A; Sawatzky, B; Schulte, E; Shabestari, M; Shahinyan, A; Shneor, R; Sirca, S; Slifer, K; Solvignon, P; Song, J; Sparks, R; Subedi, R; Urciuoli, G M; Wang, K; Wojtsekhowski, B; Yan, X; Yao, H; Zhan, X; Zhu, X

    2010-01-01

    High precision measurements of induced and transferred recoil proton polarization in d(polarized gamma, polarized p})n have been performed for photon energies of 277--357 MeV and theta_cm = 20 degrees -- 120 degrees. 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.

  9. Dosimetric Characteristics of Circular 6-MeV X-Ray Beams for Stereotactic Radiotherapy with a Linear Accelerator

    Science.gov (United States)

    Wysocka, A.; Rostkowska, J.; Kania, M.; Bulski, W.; Fijuth, J.

    2000-01-01

    Dosimetric characteristics of 6 MeV circular X-ray beams of diameters ranging from 7.5 to 35.0 mm are reported. The 6-MeV X-ray beam from Clinac 2300CD was formed using additional cylindrical BrainLAB's collimators. The mechanical stability of the entire system was verified. Specific quantities measured include tissue maximum ratios (TMR), beam profiles (off-axis ratios OAR) and relative output factors. Measurements of these parameters were performed in a water phantom using small cylindrical ionization chambers and a diamond detector. Comparison of TMR values measured with the ionization chamber and the diamond detector showed no significant differences. It was shown that the latter yields more accurate results for beam profiles than ionization chambers. The mechanical and dosimetric characteristics of this radiotherapy unit are found to be suitable for stereotactic radiosurgery and radiotherapy.

  10. Low energy spread 100 MeV-1 GeV electron bunches from laser wakefield acceleration at LOASIS

    International Nuclear Information System (INIS)

    Experiments at the LOASIS laboratory of LBNL recently demonstrated production of 100 MeV electron beams with low energy spread and low divergence from laser wakefield acceleration. The radiation pressure of a 10 TW laser pulse guided over 10 diffraction ranges by a plasma density channel was used to drive an intense plasma wave (wakefield), producing acceleration gradients on the order of 100 GV/m in a mm-scale channel. Beam energy has now been increased from 100 to 1000 MeV by using a cm-scale guiding channel at lower density, driven by a 40TW laser, demonstrating the anticipated scaling to higher beam energies. Particle simulations indicate that the low energy spread beams were produced from self trapped electrons through the interplay of trapping, loading, and dephasing. Other experiments and simulations are also underway to control injection of particles into the wake, and hence improve beam quality and stability further

  11. 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.

  12. 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)

  13. Evidence for detection of 1-10 MeV emission from the Taurus region in 1971 August

    Science.gov (United States)

    Gruber, D. E.; Ling, J. C.

    1977-01-01

    Results are reported for three observations of the Crab Nebula with a balloon-borne actively collimated NaI detector over the energy range from 0.2 to 10 MeV. Possible changes in instrument performance and environmental background levels during the balloon flights are investigated, and fits for source strength are made over four broad energy channels. X-ray power-law spectra and pulsed-flux fractions are determined for both the Crab Nebula and its pulsar, NP 0532. A statistically significant flux greatly in excess of the power law was detected above 1 MeV during one flight; this flux, which has declined by at least a factor of 4 or 5 at the times of more recent observations, is assumed to be real and is attributed to the nebula.

  14. A study of radiation effects of 9 and 12 MeV protons on Chinese CMOS image sensor degradation

    Institute of Scientific and Technical Information of China (English)

    MENG Xiang-Ti; HUANG Qiang; MA Yan-Xiu; ZHENG Yong-Nan; FAN Ping; ZHU Sheng-Yun

    2008-01-01

    The 9 and 12 MeV proton irradiations of the Chinese CMOS Image Sensor in the fluence range from 1×109to 4×1010 cm-2and 1×109 to 2×1012 cm-2 have been carried out respectively. The color pictures and dark output images are captured, and the average brightness of dark output images is calculated. The anti-irradiation fluence thresholds for 9 and 12 MeV protons are about 4×1010 and 2×1012 cm-2, respectively. These can be explained by the change of the concentrations of irradiation-induced electron-hole pairs and vacancies in the various layers of CMOS image sensor calculated by the TRIM simulation program.

  15. Development of polystyrene calorimeter for application at electron energies down to 1.5 MeV

    DEFF Research Database (Denmark)

    Miller, A.; Kovacs, A.; Kuntz, F.

    2002-01-01

    were tested: (1) real time temperature measurement during the irradiation and (2) pre- and post-irradiation temperature measurement. The advantages and drawbacks of these methods are discussed. Depth dose measurements have been carried out in the PS calorimeter to define the relationship between the...... average and the surface dose and to prove the applicability of the new low energy calorimeter for calibration purposes at 1.5 and 2 MeV electron energy. Alanine dosimeters of 2 mm thickness were used to calibrate the calorimeters and their use for nominal dose measurements was demonstrated in a series of...... intercomparisons. The use as routine dosimeters at electron accelerators operating in the energy range of 1.5-4 MeV was also demonstrated. (C) 2002 Elsevier Science Ltd. All rights reserved....

  16. Astronomical telescope for photons-gamma rays of low energy (approximately 4 MeV using the difference method like a Venetian blind

    Science.gov (United States)

    de Aguiar, O. D.; Martin, I. M.

    1980-07-01

    A description of a gamma ray telescope, which is sensitive to photons in the energy range of 3 - 10 MeV is presented. Collimation was provided by a passive shield which functioned somewhat like a 'venetian blind' to block the signal from one of the detectors. Signal subtraction techniques were used to obtain the desired information.

  17. Undamped surface waves in the scattering of 16O + 28Si at E/sub c. m./ = 35 MeV

    International Nuclear Information System (INIS)

    The elastic scattering of 16O + 28Si at E/sub c. m./ = 35 MeV has been measured in the angular range 20degree -2. The structure at backward angles is of the form of a Legendre Polynomial (mod P/sub l 26/(costheta))2, indicating the existence of a partial-wave (orbiting) resonance

  18. MeV ion beam deformation of colloidal silica particles

    International Nuclear Information System (INIS)

    Spherical sub-micrometer-sized silica particles were prepared by the Stoeber process, from a reaction mixture containing tetraethoxysilane, ammonia and ethanol, and deposited into silicon wafers. The samples were then irradiated at room temperature with 4 MeV Si, Ti, Pt or Au ions at a fluence of 4 x 1015 ions/cm2, under an angle of 49o with respect to the sample surface. The size, size distribution and shape of the silica particles were determined using scanning electron microscopy (SEM) and atomic force microscopy (AFM). After the irradiation the spherical silica particles can be turned into ellipsoidal particles, as a result of the increase of the particle dimension perpendicular to the ion beam and a decrease in the direction parallel to the ion beam. This effect increases with the ion fluence and depends on the electronic stopping power of the impinging ion. For the series of 4 MeV ions we used in this work a relative transverse diameter change of 17% per 1 keV/nm was obtained and it seems that no threshold for the electronic energy loss exists

  19. Advantages and limits of 14-MeV neutron radiography

    Energy Technology Data Exchange (ETDEWEB)

    Brzosko, J.S. (Istituto Avogadro di Tecnologia, S.R.L., Ravenna (Italy) Stevens Inst. of Tech., Hoboken, NJ (United States)); Robouch, B.V. (Ass. EURATOM-ENEA, Centro Ricerche Energie, Frascati (Italy)); Ingrosso, L. (Avogadro Energy Systems Inc., New York (United States)); Bortolotti, A. (Ferrara Univ. (Italy)); Nardi, V. (Stevens Inst. of Tech., Hoboken, NJ (United States) Ferrara Univ. (Italy))

    1992-10-01

    The paper evaluates the potentials of fast-neutron radiography (FNR) for the inspection of bulky, solid objects. Data for both a fast (E[sub n] = 14.7 MeV) and a slow (E[sub n] = 0.1 eV) neutron source are compared. The reproduction of images consists of Monte Carlo simulations of (a) the neutron random walk in a slab (iron, SiC ceramic, and polyethelene (CH[sub 2])[sub n] plastic) with a void, (b) the process of neutron recording in a detector, and (c) a print-out of images. For a general analysis, 3D-MCSC-RWR software operates without simplification of either the FNR design or the nuclear data files. The results first show the feasibility of the use of 14-MeV neutron radiography, then the superiority of FNR over slow-neutron radiography in-the-field when the thickness of the full slab is over 1 cm and requires a resolution better than 0.1 mm. Examples of some numerically simulated images as well as FNR scaling functions are shown. A review of the available fast-neutron sources reveals that only plasma-focus machines would simultaneously meet all FNR requirements: Y[sub n] [>=] 10[sup 13] n/pulse, small-source dimensions and mobility.

  20. Advantages and limits of 14-MeV neutron radiography

    International Nuclear Information System (INIS)

    The paper evaluates the potentials of fast-neutron radiography (FNR) for the inspection of bulky, solid objects. Data for both a fast (En = 14.7 MeV) and a slow (En = 0.1 eV) neutron source are compared. The reproduction of images consists of Monte Carlo simulations of (a) the neutron random walk in a slab (iron, SiC ceramic, and polyethelene (CH2)n plastic) with a void, (b) the process of neutron recording in a detector, and (c) a print-out of images. For a general analysis, 3D-MCSC-RWR software operates without simplification of either the FNR design or the nuclear data files. The results first show the feasibility of the use of 14-MeV neutron radiography, then the superiority of FNR over slow-neutron radiography in-the-field when the thickness of the full slab is over 1 cm and requires a resolution better than 0.1 mm. Examples of some numerically simulated images as well as FNR scaling functions are shown. A review of the available fast-neutron sources reveals that only plasma-focus machines would simultaneously meet all FNR requirements: Yn ≥ 1013 n/pulse, small-source dimensions and mobility

  1. First Light: MeV Astrophysics from the Moon

    Science.gov (United States)

    Miller, Richard S.; Lawrence, David J.

    2016-06-01

    We report evidence of the first astrophysical source detected from the Moon at MeV energies. Our detection of Cygnus X-1 is a validation of a new investigative paradigm in which the lunar environment is intrinsic to the detection approach: the Lunar Occultation Technique (LOT). NASA’s Lunar Prospector mission served as a proxy for a dedicated LOT-based mission. The characteristic signature of temporal modulation, generated by repeated lunar occultations and encoded within acquired gamma-ray data (0.5–9 MeV), is consistent with an unambiguous detection of Cygnus X-1 at 5.4σ significance. Source localization and long-term monitoring capabilities of the LOT are also demonstrated. This “first light” detection verifies the basic tenets of the LOT methodology, reinforces its feasibility as an alternative astronomical detection paradigm for nuclear astrophysics investigations, and is an illustration of the fundamental benefits of the Moon as a platform for science.

  2. Effect of 3.0 MeV helium implantation on electrical characteristics of 4H-SiC BJTs

    Science.gov (United States)

    Usman, Muhammad; Hallén, Anders; Ghandi, Reza; Domeij, Martin

    2010-11-01

    Degradation of 4H-SiC power bipolar junction transistors (BJTs) under the influence of a high-energy helium ion beam was studied. Epitaxially grown npn BJTs were implanted with 3.0 MeV helium in the fluence range of 1010-1011 cm-2. The devices were characterized by their current-voltage (I-V) behaviour before and after the implantation, and the results showed a clear degradation of the output characteristics of the devices. Annealing these implanted devices increased the interface traps between passivation oxide and the semiconductor, resulting in an increase of base current in the low-voltage operation range.

  3. 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.

  4. A detailed test of a BSO calorimeter with 100-800 MeV positrons

    Energy Technology Data Exchange (ETDEWEB)

    Ishikawa, T., E-mail: ishikawa@lns.tohoku.ac.jp [Research Center for Electron Photon Science, Tohoku University, Sendai 982-0826 (Japan); Fujimura, H.; Hashimoto, R.; Kaida, S.; Kasagi, J.; Kitazawa, R.; Kuwasaki, S.; Nakamura, A.; Nawa, K.; Okada, Y.; Sato, M.; Shimizu, H.; Suzuki, K. [Research Center for Electron Photon Science, Tohoku University, Sendai 982-0826 (Japan); Tajima, Y. [Department of Physics, Yamagata University, Yamagata 990-8560 (Japan); Takahashi, S.; Tsuchikawa, Y.; Yamazaki, H. [Research Center for Electron Photon Science, Tohoku University, Sendai 982-0826 (Japan); Yoshida, H.Y. [Department of Physics, Yamagata University, Yamagata 990-8560 (Japan)

    2012-12-01

    A performance test has been made for an electro-magnetic calorimeter prototype comprised four identical BSO crystals arranged in a 2 Multiplication-Sign 2 matrix by utilizing a positron beam in the energy range from 100 to 800 MeV. The size of each crystal is 40 Multiplication-Sign 40 Multiplication-Sign 210 mm{sup 3}. This is the world's largest BSO single crystal ever used as a photon detector. The obtained energy resolution is ({sigma}{sub E}/E){sup 2}=((1.71%{+-}0.03%)/{radical}(E)){sup 2}+(1.12%{+-}0.08%){sup 2} at room temperature, where E is the incident positron energy given in GeV. A BGO calorimeter having the same geometry has been employed in the performance test for comparison. The basic scintillation characteristics of BSO crystals measured without the beam are also presented.

  5. Intercomparison exercise with MeV neutrons using various electronic personal dosimeters

    International Nuclear Information System (INIS)

    Electronic personal neutron dosimeters developed at GSF, PTB, and LMU, were exposed with mono-energetic neutrons at the PTB neutron irradiation facility in Braunschweig, Germany. The neutron energies used ranged from 1.5 to 4.1 MeV. The doses measured by each dosimeter were compared to each other and to the Saphydose-n dosimeter that is commercially available. All dosimeters were calibrated based on either 252Cf and/or 241Am-Be neutron sources or a 60Co secondary standard reference field. The doses measured were compared to estimates of reference values based on a long counter. Generally, all dosimeters produced reasonable results, given the uncertainties involved. It was noticed that the dosimeter responses show slight dependencies on energy. The corresponding differences are summarised and discussed

  6. Ion shaking in the 200 MeV XLS-ring

    Energy Technology Data Exchange (ETDEWEB)

    Bozoki, E.; Kramer, S.L.

    1992-12-31

    It has been shown that ions, trapped inside the beam`s potential, can be removed by the clearing electrodes when the amplitude of the ion oscillation is increased by vertically shaking the ions. We will report on a similar experiment in the 200 Mev XLS ring. The design of the ion clearing system for the ring and the first results obtained, were already reported. In the present series of experiments, RF voltage was applied on a pair of vertical strip-lines. The frequency was scanned in the range of the ion (from H{sub 2} to CO{sub 2}) bounce frequencies in the ring (1--10 MHz). The response of the beam size, vertical betatron tune and lifetime was studied.

  7. Ion shaking in the 200 MeV XLS-ring

    Energy Technology Data Exchange (ETDEWEB)

    Bozoki, E.; Kramer, S.L.

    1992-01-01

    It has been shown that ions, trapped inside the beam's potential, can be removed by the clearing electrodes when the amplitude of the ion oscillation is increased by vertically shaking the ions. We will report on a similar experiment in the 200 Mev XLS ring. The design of the ion clearing system for the ring and the first results obtained, were already reported. In the present series of experiments, RF voltage was applied on a pair of vertical strip-lines. The frequency was scanned in the range of the ion (from H[sub 2] to CO[sub 2]) bounce frequencies in the ring (1--10 MHz). The response of the beam size, vertical betatron tune and lifetime was studied.

  8. Development of MeV cluster ion beams and irradiation effects

    Energy Technology Data Exchange (ETDEWEB)

    Saito, Yuichi; Mizuhashi, Kiyoshi; Tajima, Satoshi; Arakawa, Kazuo [Japan Atomic Energy Research Inst., Takasaki, Gunma (Japan). Takasaki Radiation Chemistry Research Establishment; Hirata, Kouichi; Kobayashi, Yoshinori [National Inst. of Materials and Chemical Research, Tsukuba, Ibaraki (Japan)

    2001-02-01

    The production and acceleration of cluster ion beams were developed by using a sputtering ion source and a tandem accelerator. Molecular beams of iron oxides were produced from Fe{sub 2}O{sub 3} powder prepared as the specimen of the ion source and accelerated to energy of MeV range. Defect densities in silicon and polycarbonate targets by irradiation were compared between monoatomic carbon ions and carbon cluster beams (C{sub 2}-C{sub 4}). Beam currents by injection of carbon cluster beams (C{sub 8}) were measured for various targets such as Si, Al, Al{sub 2}O{sub 3} and polycarbonate. The target and time dependence of the beam currents were originated from sputtered ions due to water molecules and oxides adhered at the surface of the targets. (Y. Kazumata)

  9. Physical and chemical response of 70 MeV carbon ion irradiated Kapton-H polymer

    Indian Academy of Sciences (India)

    H S Virk; P S Chandi; A K Srivastava

    2001-10-01

    Physical and chemical responses of 70 MeV carbon ion irradiated Kapton-H polymer were studied by using UV-visible, FTIR and XRD techniques. The ion fluences ranging from 9.3 × 1011–9 × 1013 ions cm–2 were used. Recorded UV-visible spectra clearly showed a decrease in absorption initially with fluence, but for the higher fluences it showed a recovery characteristic. A decrease in band-gap energy of 0.07 eV was observed. The FTIR analysis indicated the high resistance to radiation induced degradation of polymer. The diffraction pattern of Kapton-H indicates that this polymer is semi-crystalline in its nature. In case of irradiated one, there was an average increase of crystallite size by 20%, but diffuse pattern indicates that there was a decrease in crystallinity, which may be attributed to the formation of complex structure induced by the cross-linking of the polymeric chains.

  10. 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.

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

    DEFF Research Database (Denmark)

    Barlow, P.; Leffers, Torben

    1977-01-01

    irradiation temperatures corresponding to the highest source densities is approximately 350°–500°C. The climb sources are not related to any pre-existing dislocations resolved in the microscope. The sources emit three types of loop: ‘rectangular’ loops with a100 Burgers vector and {100} habit plane, normal...... prismatic loops with Burgers vector a/2110, and Frank loops. There is no significant difference between the apparent activation energy for growth of the three types of loops. The source points are suggested to be submicroscopic nickel precipitates-with reference to the existing evidence that......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...

  12. Pion scattering from polarized 15N at Tπ=164 MeV

    International Nuclear Information System (INIS)

    The analyzing power Ay was measured for π+endash 15 rvec N elastic scattering at Tπ=164 MeV between 40 degree and 100 degree using a polarized 15NH3 target. Within the statistical accuracy of the data Ay(θ) was found to be zero over the full angular range. These data together with differential cross sections from the literature are compared with theoretical predictions based on a momentum-space coupled-channel formalism. While the cross section is very well reproduced there are large discrepancies in the analyzing power for which large spin effects are predicted close to the cross-section minima. Possible deficiencies in the theoretical model are discussed

  13. Structural evolution of Co/Cu nanostructures under 1 MeV ion-beam irradiation

    International Nuclear Information System (INIS)

    Co/Cu multilayers with composition wavelength ranging from 2 to 10 nm have been deposited and irradiated at various doses from 1x1014 to 3x1016 ions/cm2 using 1 MeV Si+ ions. The ion-beam-induced variation in structural properties such as interfacial mixing, interface roughness, crystallographic texture, and grain size, are characterized by a variety of x-ray scattering techniques. Irradiating Co/Cu multilayers generate metastable Co-Cu alloys whose electrical and magnetic properties have been found to be very similar to the Co-Cu alloys fabricated by other nonequilibrium methods. Fitting to the low-angle x-ray reflectivity spectra using a standard optical model yields a mixing efficiency comparable to the prediction of a ballistic ion-beam mixing model, and interfacial mixing widths consistent with the values estimated from saturation magnetization measurements

  14. Calibration of imaging plates to electrons between 40 and 180 MeV.

    Science.gov (United States)

    Rabhi, N; Bohacek, K; Batani, D; Boutoux, G; Ducret, J-E; Guillaume, E; Jakubowska, K; Thaury, C; Thfoin, I

    2016-05-01

    This paper presents the response calibration of Imaging Plates (IPs) for electrons in the 40-180 MeV range using laser-accelerated electrons at Laboratoire d'Optique Appliquée (LOA), Palaiseau, France. In the calibration process, the energy spectrum and charge of electron beams are measured by an independent system composed of a magnetic spectrometer and a Lanex scintillator screen used as a calibrated reference detector. It is possible to insert IPs of different types or stacks of IPs in this spectrometer in order to detect dispersed electrons simultaneously. The response values are inferred from the signal on the IPs, due to an appropriate charge calibration of the reference detector. The effect of thin layers of tungsten in front and/or behind IPs is studied in detail. GEANT4 simulations are used in order to analyze our measurements. PMID:27250413

  15. 520 MeV proton irradiation effects on GaAs/Ge space solar cells

    CERN Document Server

    Wang Rong; Guo Zeng Liang; Zhang Xin; Zhai Zuo Xu

    2002-01-01

    High-energy proton irradiation effects on GaAs/Ge solar cells for space use are studied. The cells are irradiated by protons with an energy of 5-20 MeV up to a fluence ranging from 1 x 10 sup 9 to 7 x 10 sup 1 sup 3 cm sup - sup 2 , and then the change of the photovoltaic performances is measured at AMO. It is shown that the performances of the cells keep no change under 1 x 10 sup 9 cm sup - sup 2 irradiation. Above 1 x 10 sup 9 cm sup - sup 2 irradiation, I sub s sub c , V sub o sub c and P sub m sub a sub x degrade, as proton irradiation fluence increases. But the higher the proton energy, the less the degradation of I sub s sub c , V sub o sub c and P sub m sub a sub x

  16. Ion shaking in the 200 MeV XLS-ring

    International Nuclear Information System (INIS)

    It has been shown that ions, trapped inside the beam's potential, can be removed by the clearing electrodes when the amplitude of the ion oscillation is increased by vertically shaking the ions. We will report on a similar experiment in the 200 Mev XLS ring. The design of the ion clearing system for the ring and the first results obtained, were already reported. In the present series of experiments, RF voltage was applied on a pair of vertical strip-lines. The frequency was scanned in the range of the ion (from H2 to CO2) bounce frequencies in the ring (1--10 MHz). The response of the beam size, vertical betatron tune and lifetime was studied

  17. Ion shaking in the 200 MeV XLS-ring

    Science.gov (United States)

    Bozoki, E.; Kramer, S. L.

    1992-03-01

    It has been shown that ions, trapped inside the beam's potential, can be removed by the clearing electrodes when the amplitude of the ion oscillation is increased by vertically shaking the ions. We will report on a similar experiment in the 200 MeV XLS ring. The design of the ion clearing system for the ring and the first results obtained were already reported. In the present series of experiments, RF voltage was applied on a pair of vertical strip-lines. The frequency was scanned in the range of the ion (from H2 to CO2) bounce frequencies in the ring (1-10 MHz). The response of the beam size, vertical betatron tune, and lifetime was studied.

  18. 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 ...

  19. Elastic scattering for 16O + 12C at 140 MeV and 218 MeV

    International Nuclear Information System (INIS)

    In this work, angular distribution of cross sections have been measured for 12C(16O,16O)12C at two energies. The measurements were carried out in 0.50 intervals between 50-19.50C (lab.) at 140 MeV, 4.50-14.50 at 218 MeV. An optical model analysis of these strong structure angular distributions was done. Good fits of the data were obtained using the optical model search code GENOA with a full Woods-Saxon potential form. This yielded parameters subject to considerable ambiguities as it is known to occur for strongly absorbed particles. These ambiguities were explored in detail and it was found that both the real and the imaginary parts present some characteristics that have been found before for the real potential (as Igo relation for continous ambiguities and the fact that potentials with different diffusivities tend to have the same value at the strong absorption radii). It was found, among other results, that the real volume integral, the mean square radius, as well as the total reaction cross section (σsub(r)) cannot be determined unambiguously. A strong correlation was found between σsub(r) and the imaginary diffusivity. A systematic study of how the variation of the potential parameters affects the angular distribution is presented and some features of the diffraction structure of the angular distribution are discussed. (author)

  20. A Monte Carlo comparison of PGNAA system performance using 252Cf neutrons, 2.8-MeV neutrons and 14-MeV neutrons

    Science.gov (United States)

    Naqvi, A. A.

    2003-10-01

    Monte Carlo simulations were carried out to compare performance of a 252Cf neutron and a 14-MeV neutron-based prompt γ-ray neutron activation analysis (PGNAA) system with that of the 2.8-MeV neutron-based PGNAA system at King Fahd University of Petroleum and Minerals (KFUPM), Dhahran, Saudi Arabia. Since the energy of neutron beam used in the KFUPM PGNAA system is very close to that produced by a DD neutron generator, performance comparison between a DD and a DT neutron generator-based PGNAA system is highly desired. For the sake of comparison, the calculations were carried out for the PGNAA system with geometry similar to the KFUPM PGNAA system. These calculations were required to determine improvement in performance of the KFUPM PGNAA system if its 2.8-MeV neutron source is replaced by a 252Cf neutron source or a 14-MeV neutron source. Results of the calculations revealed that the geometry of the 252Cf neutron and the 2.8-MeV neutron-based PGNAA system are not significantly different but the geometry of the 14-MeV neutron-based system is significantly different from that of the 2.8-MeV neutron-based PGNAA system. Accordingly, the prompt γ-ray yields from the 252Cf neutron and the 2.8-MeV neutron-based PGNAA system is comparable but prompt γ-ray yields from 14-MeV neutron-based PGNAA system are about three times smaller than that from the 2.8-MeV neutron-based PGNAA system. This study has shown that performance of the 252Cf neutron-based PGNAA system is comparable with that of the 2.8-MeV neutron-based PGNAA system but the performance of the 14-MeV neutron-based PGNAA system is poorer than that of the 2.8-MeV neutron-based PGNAA system.

  1. A Monte Carlo comparison of PGNAA system performance using {sup 252}Cf neutrons, 2.8-MeV neutrons and 14-MeV neutrons

    Energy Technology Data Exchange (ETDEWEB)

    Naqvi, A.A. E-mail: aanaqvi@kfupm.edu.sa

    2003-10-01

    Monte Carlo simulations were carried out to compare performance of a {sup 252}Cf neutron and a 14-MeV neutron-based prompt {gamma}-ray neutron activation analysis (PGNAA) system with that of the 2.8-MeV neutron-based PGNAA system at King Fahd University of Petroleum and Minerals (KFUPM), Dhahran, Saudi Arabia. Since the energy of neutron beam used in the KFUPM PGNAA system is very close to that produced by a DD neutron generator, performance comparison between a DD and a DT neutron generator-based PGNAA system is highly desired. For the sake of comparison, the calculations were carried out for the PGNAA system with geometry similar to the KFUPM PGNAA system. These calculations were required to determine improvement in performance of the KFUPM PGNAA system if its 2.8-MeV neutron source is replaced by a {sup 252}Cf neutron source or a 14-MeV neutron source. Results of the calculations revealed that the geometry of the {sup 252}Cf neutron and the 2.8-MeV neutron-based PGNAA system are not significantly different but the geometry of the 14-MeV neutron-based system is significantly different from that of the 2.8-MeV neutron-based PGNAA system. Accordingly, the prompt {gamma}-ray yields from the {sup 252}Cf neutron and the 2.8-MeV neutron-based PGNAA system is comparable but prompt {gamma}-ray yields from 14-MeV neutron-based PGNAA system are about three times smaller than that from the 2.8-MeV neutron-based PGNAA system. This study has shown that performance of the {sup 252}Cf neutron-based PGNAA system is comparable with that of the 2.8-MeV neutron-based PGNAA system but the performance of the 14-MeV neutron-based PGNAA system is poorer than that of the 2.8-MeV neutron-based PGNAA system.

  2. Degradation of micromorph silicon solar cells after exposure to 65 MeV protons

    Energy Technology Data Exchange (ETDEWEB)

    Neitzert, Heinz-Christoph [DIIIE, Salerno University, Fisciano (Italy); NanoMates, Salerno University, Fisciano (Italy); Labonia, Laura; Citro, Michele [DIIIE, Salerno University, Fisciano (Italy); Delli Veneri, Paola; Mercaldo, Lucia [ENEA Portici Research Center (Italy)

    2010-04-15

    Silicon micromorph tandem solar cells, grown on commercial TCO coated substrates by plasma enhanced chemical vapour deposition, with an initial efficiency higher than 10%, have been degraded, in order to check their stability under space conditions, by irradiation with 65 MeV protons with fluences ranging from 10{sup 12}protons/cm{sup 2} up to 10{sup 14}protons/cm{sup 2}. For low proton fluences we find a stronger decrease of the top amorphous cell photocurrent due to the stronger impact of the proton beam on the glass substrate transparency in the visible wavelength range, as compared to the infrared range. Only for very high fluences a stronger degradation of the photocurrent in the infrared wavelength range where the bottom microcrystalline cell is dominating the spectral response, has been observed. Because the non-irradiated cell has been found to be spectrally mismatched in favour of the top amorphous cell under AM1.5 and even more under AM0 irradiation conditions, for low and intermediate fluences the irradiation decreases the spectral mismatch of the micromorph tandem cells and results consequently in a relative stabilization of the irradiation induced degradation. (copyright 2010 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  3. Spectrum of atmospheric gamma rays to 10 MeV at lambda = 40 deg. [as function of altitude

    Science.gov (United States)

    Peterson, L. E.; Schwartz, D. A.; Ling, J. C.

    1973-01-01

    Results of measurements of the differential counting rate spectra due to atmospheric gamma rays as a function of altitude to 3.6 g/sq cm over Texas. Two gain settings and a 128-channel pulse height analyzer were used to cover the range from 0.2 to 10 MeV. The detector was a 7.6 x 7.6 cm NaI crystal, which was surrounded on five sides by a 2-cm-thick plastic anticoincidence shield for charged particle rejection. The system had a nearly isotropic response to photons above 0.2 MeV. The spectrum at ceiling appeared as a steep continuum with a power-law index of about 1.4. The only obvious feature was the 0.51-MeV positron annihilation line. The spectral shape was independent for depths less than 20 g/sq cm, the absolute intensity varying in proportion to the intensity of the cosmic ray secondary charged particles. Also, at depths less than 30 g/sq cm the observed flux variation with altitude can be described in terms of an empirical depth-dependent source function.

  4. 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...

  5. A new method for the determination of unknown neutron fluence for 14.0 MeV

    Energy Technology Data Exchange (ETDEWEB)

    Malik, Fariha [Physics Reasearch Division, PINSTECH, Nilore, Islamabad (Pakistan)]. E-mail: fariha@pinstech.org.pk; Khan, Ehsan U. [Department of Physics, CIIT, Islamabad (Pakistan); Qureshi, Imtinan [Physics Reasearch Division, PINSTECH, Nilore, Islamabad (Pakistan); Husaini, Syed N. [Physics Reasearch Division, PINSTECH, Nilore, Islamabad (Pakistan); Ahmad, Waqar [Physics Reasearch Division, PINSTECH, Nilore, Islamabad (Pakistan); Rajput, Usman [Physics Reasearch Division, PINSTECH, Nilore, Islamabad (Pakistan); Raza, Qaiser [Applied Physics Division, PINSTECH, Nilore, Islamabad (Pakistan)

    2006-11-15

    Measuring the correct neutron fluence in various energy intervals in and around the neutron sources is important for the purpose of personnel and environmental neutron dosimetry. In this paper, we present a new method for the measurement of the fluence of mono-energetic neutrons having the energy of 14.0 MeV. The samples exposed to neutrons from the 14.0 MeV neutron generator at PINSTECH with various fluence values ranging from 10{sup 7} to 10{sup 10} n cm{sup -2} were etched for 10 min in 6 N NaOH at 70.0{+-}1.0 {sup o}C and the transmittance of UV radiation was measured using a spectrophotometer. This procedure was repeated 20 times after etching the same sample each time for increasing time intervals till the stage when transmittance reached the constant minimum value. An exponential decay of the transmittance has been observed with respect to the increasing etching time interval in each of the samples exposed to various neutron fluence. Further, it has also been observed that there is a linear relationship between the transmittance decay constant and neutron fluence. Hence, the linear graph can be used as a calibration for measuring the unknown fluence of 14.0 MeV neutrons.

  6. 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

    2010-06-01

    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 (252)Cf and (241)AmBe 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.

  7. Sustained performance of 8 MeV Microtron

    International Nuclear Information System (INIS)

    Energetic electrons and intense bremsstrahlung radiation from 8 MeV Microtron are being utilized in variety of collaborative research programs in radiation physics and allied sciences involving premier institutions of the country and sister universities of the region. The first of its kind electron accelerator in the country, set up at Mangalore University in collaboration with RRCAT Indore and BARC Mumbai, has been facilitating researchers since its inception with its inherent simplicity, ease of construction, low cost and excellent beam quality. A bird's eye view on the reliable aspects of the machine, efforts behind the continuous operation of the accelerator and important applications of the accelerator in physical and biological sciences are presented in this paper.

  8. Two charmoniumlike charged axial resonances near 3885 MeV

    CERN Document Server

    Voloshin, M B

    2016-01-01

    It is argued that the charged $Z^+_c(3885)$ resonance, treated as a `molecular' state of charmed $D$ and $D^*$ mesons, is likely to consist of two peaks unequally coupled to the $D^{*+} \\bar D^0$ and $D^+ \\bar D^{*0}$ channels. The peaks should be split in mass by at least approximately 1.5 MeV. This behavior arises from an enhancement of the effect of isospin violation in the masses of the $D$ and $D^*$ mesons due to apparent suppression of forces between the mesons depending on the spins of the heavy as well as of the light quarks. The suggested double-peak structure can be studied either by direct shape measurement in the channels with heavy mesons, or by isospin-violating transitions from $Z_c^\\pm(3885)$ to the states of charmonium plus a light meson.

  9. 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)

  10. 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.

  11. 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

  12. The 5 MeV bump - a nuclear whodunit mystery

    CERN Document Server

    Huber, Patrick

    2016-01-01

    We perform a combined analysis of recent NEOS and Daya Bay data on the reactor antineutrino spectrum. This analysis includes approximately 1.5 million antineutrino events, which is the largest neutrino event sample analyzed to date. We use a double ratio which cancels flux model dependence and related uncertainties as well as the effects of the detector response model. We find at 3-4 standard deviation significance level, that plutonium-239 and plutonium-241 are disfavored as the single source for the the so-called 5 MeV bump. This analysis method has general applicability and in particular with higher statistics data sets will be able to shed significant light on the issue of the bump. With some caveat this also should allow to improve the sensitivity for sterile neutrino searches in NEOS.

  13. 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.

  14. Inclusive π- production in heavy ion collisions below 100 A MeV

    International Nuclear Information System (INIS)

    Negative pion production in 41 A MeV 14N + C reaction was studied for Tπ ≥ 30 MeV and θlab ≤ 90 degrees. The cross sections fall exponentially with Tpi and the exponential slope factor in the spectrum at 95 degrees in the center of mass frame is determined to be 17.5 ± 2.0 MeV. The slope factor was found to be constant below beam energy. 100 A MeV which is anomalous compared to the monotonic decrease of the slope factor down to 100 A MeV. In this paper the preliminary result for 67 A MeV is given. The production mechanism of energetic pions far below the N-N threshold is discussed under several models

  15. Compton-Pair Production Space Telescope (ComPair) for MeV Gamma-ray Astronomy

    CERN Document Server

    Moiseev, A A; Buckley, J H; Caputo, R; Ferrara, E C; Hartmann, D H; Hays, E; McEnery, J E; Mitchell, J W; Ojha, R; Perkins, J S; Racusin, J L; Smith, A W; Thompson, D J

    2015-01-01

    The gamma-ray energy range from a few hundred keV to a few hundred MeV has remained largely unexplored, mainly due to the challenging nature of the measurements, since the pi- oneering, but limited, observations by COMPTEL on the Compton Gamma-Ray Observatory (1991-2000). This energy range is a transition region between thermal and nonthermal processes, and accurate measurements are critical for answering a broad range of astrophysical questions. We are developing a MIDEX-scale wide-aperture discovery mission, ComPair (Compton-Pair Production Space Telescope), to investigate the energy range from 200 keV to > 500 MeV with high energy and angular resolution and with sensitivity approaching a factor of 100 better than COMPTEL. This instrument will be equally capable to detect both Compton-scattering events at lower energy and pair-production events at higher energy. ComPair will build on the her- itage of successful space missions including Fermi LAT, AGILE, AMS and PAMELA, and will utilize well-developed space...

  16. Modification of radiobiological effects of 171 MeV protons by elements of physical protection

    Science.gov (United States)

    Bulinina, Taisia; Shurshakov, Vyacheslav; Ivanov, Alexander; Molokanov, Alexander

    2016-07-01

    Space radiation includes protons of various energies. Physical protection is effective in the case of low energy protons (50-100 MeV) and becomes insufficient for radiation with a high part of high-energy protons. In the experiment performed on outbred mice, the purpose of the study was to evaluate the radiobiological effect of 171 MeV protons and protons modified by elements of physical protection of the spacecraft, on a complex of indicators of the functional condition of the system hematopoiesis and the central nervous system in 24 hours after irradiation at 20 cGy dose. The spacecraft radiation protection elements used in the experiment were a construction of wet hygiene wipes called a «protective curtain», and a glass plate imitating an ISS window. Mass thickness of the " protective curtain" in terms of water equivalent was ̴ 6,2 g/cm2. Physical shielding along the path of 171 MeV protons increases their linear energy transfer leading to the absorbed dose elevation and strengthening of the radiobiological effect. In the experiment, the two types of shielding together raised the absorbed dose from 20 to 23.2 cGy. Chemically different materials (glass and water in the wipes) were found to exert unequal modifying effects on physical and biological parameters of the proton-irradiated mice. There was a distinct dose-dependent reduction of bone marrow cellularity within the dose range from 20 cGy to 23.2 cGy in 24 hours after exposure. No modifying effect of the radiation protection elements on spontaneous motor activity was discovered when compared with entrance protons. The group of animals protected by the glass plate exhibited normal orientative-trying reactions and weakened grip with the forelimbs. The effects observed in the experiment indicate the necessity to carry out comprehensive radiobiological researches (physical, biological and mathematical) in assessing the effects of physical protection, that are actual for ensuring radiation safety of crews in

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

    International Nuclear Information System (INIS)

    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

  18. Assembly and installation of the 2 MeV FMIT accelerator

    International Nuclear Information System (INIS)

    The front end of the 35-MeV Fusion Materials Irradiation Test (FMIT) Facility accelerator is being assembled and installed at Los Alamos. The machine ultimately will produce a 500-kW continuous-duty beam at 5 MeV, although only the first 2 MeV will be installed this year. The 2-MeV system will include the most-powerful radio-frequency quadrupole (RFQ) in existence. The assembly and installation of the hardware are described, along with the unique problems arising from the large size and high power of the components involved

  19. Search for an elusive 4.4-MeV α emitter in uranium minerals

    International Nuclear Information System (INIS)

    A search for an unidentified 4.4-MeV α-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 α activity in each of four studied samples are given

  20. 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)

  1. Recombination characteristics in 2-3 MeV protons irradiated FZ Si

    Science.gov (United States)

    Gaubas, E.; Čeponis, T.; Uleckas, A.; Vaitkus, J.; Raisanen, J.

    2010-01-01

    Combined analysis of the carrier recombination and generation lifetime as well as reverse recovery durations ( τ RR), dependent on proton irradiation fluence in the range of 7×10 12-7×10 14 p/cm 2, has been performed in FZ silicon PIN diodes and wafer structures. A δ-layer and triangle profiles of radiation induced defects were formed by varying energy of protons in the range 2-3 MeV. Carrier decay constituents and values of recombination lifetime have been evaluated by employing a microwave probed photoconductivity transient technique, while deep levels spectra ascribed to generation lifetime variations have been examined by exploiting capacitance deep-level transient (DLTS) spectroscopy. Recombination lifetime decreases from several μs to few ns, while DLTS spectra show an increase in the amplitude of a DLTS peak at 170 K with irradiation fluence. Transforms of DLTS spectra and a decrease in density of the majority carrier traps have been revealed after 24 h isochronal anneals in the range of temperatures of 80-420 °C. Inhomogeneous depth distribution of recombination lifetime in proton irradiated samples has been revealed from the cross-sectional scans of the excess carrier lifetime measured by MW-PC technique and compared for δ-layer and triangle profiles of radiation induced defects. After isochronal anneals, the τ RR changes its behaviour as a function of irradiation fluence.

  2. ICPP: Scale size of of magnetic turbulence as probed with 30 MeV runaway electrons

    Science.gov (United States)

    Jaspers, Roger

    2000-10-01

    This paper reviews results concerning generation, confinement and transport of runaway electrons in the energy range 20-30 MeV in the TEXTOR tokamak. For future fusion reactors, it is of major importance to know the processes of runaway generation and runaway loss after disruptions, because of the potential damage to first wall components. Second, since the runaway electrons are effectively collisionless, their confinement is determined by the magnetic field turbulence. In this way the runaway transport provides a unique opportunity to probe turbulence in the core of a thermonuclear plasma. Runaway electrons above 20 MeV emit synchrotron radiation in the (near) infrared, which can easily be detected by thermographic cameras. This technique is developed and exploited at the TEXTOR-94 tokamak and has resulted in some spectacular results. These include: the experimental evidence of the secondary (`knock-on') runaway generation; the discovery of the runaway snake; the observation of disruption generated runaways; the probing of magnetic turbulence in the core of the plasma in Ohmic and additionally heated plasmas. The paper reviews these results with special emphasis on the subject of probing magnetic turbulence in the core of the plasma. Measurements in the TEXTOR-94 tokamak show that after switching on Neutral Beam Injection, the runaway population decays. The decay only starts with a significant delay, which decreases with increasing NBI heating power. This delay provides direct evidence of the energy dependence of runaway confinement, which is expected if magnetic modes govern the loss of runaway electrons. These observations allow to estimate the mode width δ of the magnetic perturbations:δ smaller than 0.5 cm in Ohmic discharges, increasing to δ=3D 4.4 cm for 0.6 MW NBI power.

  3. High resolution (γ, n) experiments in light nuclei at Eγ ≅ 60 MeV

    International Nuclear Information System (INIS)

    The experiments was undertaken to establish the real photon reaction mechanism on light nuclei in the intermediate photon-energy region, Eγ ≅ 60 MeV. The shortage of high quality (γ, n) data was the main motivation for starting a systematic investigation of this reaction channel. In this work, 12C and 16O were examined. In the future, both heavier (40Ca) and lighter (4He) targets will be investigated. Two neutron detector arrays were built and tested. A state-of-the-art neutron spectrometer was constructed by combining these arrays with a high resolution (≅ 300 keV) photon tagger. The intrinsic time resolution of this spectrometer (≅ 800 ps) allowed an excellent neutron energy resolution to be achieved (≅ 1 MeV) with fairly short flight paths (≅ 6 m), thereby optimizing the geometrical efficiency (≅ 10 msr) of the apparatus. The excellent energy resolution of the spectrometer allowed individual states (or cluster of states) to be resolved. This resolution approaches that available for the (γ, p) reaction. For 12C and 16O the same states seen in the (γ, p) reaction were observed over an angular range from 30-115 degrees. The most important result, concerning the obtained absolute differential cross sections, is the striking similarity between the (γ, p) and (γ, n) reaction channels. This applies to both target nuclei for all populated states, independent of character (1h or 2h1p). A much detailed comparison is thus possible with these new data, providing greater constraints on the theoretical models. Further, access to more and better data will hopefully attract greater theoretical interest. The experiment was a collaboration between the Photonuclear research group at Lund University in Sweden and the Nuclear structure group from the University of Glasgow. The data were collected at MAX-lab in Lund, Sweden, during two run periods in November 1990 and February 1992. 96 refs, 105 figs, 28 tabs

  4. A comparative study of 30MeV boron4+ and 60MeV oxygen8+ ion irradiated Si NPN BJTs

    International Nuclear Information System (INIS)

    The impact of 30MeV boron4+ and 60MeV oxygen8+ ion irradiation on electrical characteristics of 2N3773 Si NPN Bipolar junction transistors (BJTs) is reported in the present study. The transistors were decapped and irradiated at room temperature. Gummel characteristics, DC current gain and Capacitance-voltage (C-V) characteristics were studied before and after irradiation at different fluences. DC current gain has decreased significantly in both boron and oxygen ion irradiation. Also the value of capacitance decreased 3-4 times with increase in fluence. Both 30MeV boron ion and 60MeV oxygen ion induced similar extent of degradation in electrical characteristics of the transistor

  5. A comparative study of 30MeV boron{sup 4+} and 60MeV oxygen{sup 8+} ion irradiated Si NPN BJTs

    Energy Technology Data Exchange (ETDEWEB)

    Kumar, M. Vinay, E-mail: Vkm288@gmail.com; Krishnaveni, S. [Department of studies in Physics, University of Mysore, Manasagangotri, Mysore 570006 (India); Yashoda, T. [Deparment of Physics, AVK College for women, Hassan-573201 (India); Dinesh, C. M. [Department of Physics, Govt. First grade college for women, Chintamani-563125 (India); Krishnakumar, K. S. [Department of Physics, APS College of Engineering (India); Jayashree, B. [Department of Physics, Maharanis Science College for Women, Bangalore-560001 (India); Ramani [Department of Physics, Bangalore University, Jnanabharathi, Bangalore-560056 (India)

    2015-06-24

    The impact of 30MeV boron{sup 4+} and 60MeV oxygen{sup 8+} ion irradiation on electrical characteristics of 2N3773 Si NPN Bipolar junction transistors (BJTs) is reported in the present study. The transistors were decapped and irradiated at room temperature. Gummel characteristics, DC current gain and Capacitance-voltage (C-V) characteristics were studied before and after irradiation at different fluences. DC current gain has decreased significantly in both boron and oxygen ion irradiation. Also the value of capacitance decreased 3-4 times with increase in fluence. Both 30MeV boron ion and 60MeV oxygen ion induced similar extent of degradation in electrical characteristics of the transistor.

  6. A comparative study of 30MeV boron4+ and 60MeV oxygen8+ ion irradiated Si NPN BJTs

    Science.gov (United States)

    Kumar, M. Vinay; Yashoda, T.; Dinesh, C. M.; Krishnakumar, K. S.; Jayashree, B.; Ramani, Krishnaveni, S.

    2015-06-01

    The impact of 30MeV boron4+ and 60MeV oxygen8+ ion irradiation on electrical characteristics of 2N3773 Si NPN Bipolar junction transistors (BJTs) is reported in the present study. The transistors were decapped and irradiated at room temperature. Gummel characteristics, DC current gain and Capacitance-voltage (C-V) characteristics were studied before and after irradiation at different fluences. DC current gain has decreased significantly in both boron and oxygen ion irradiation. Also the value of capacitance decreased 3-4 times with increase in fluence. Both 30MeV boron ion and 60MeV oxygen ion induced similar extent of degradation in electrical characteristics of the transistor.

  7. Effect of 1.33 Mev gamma radiation and 0.5 Mev electrons on the mechanical properties of graphite fiber composites

    Science.gov (United States)

    Fornes, R. E.; Memory, J. D.; Naranong, N.

    1982-01-01

    Epoxy/graphite fiber, polyimide/graphite fiber, and polysulfone/graphite fiber composites were exposed to 1.33 Mev gamma irradiation and 0.5 Mev electron bombardment for varying periods of time. The effects of the irradiation treatments on the breaking stress and Young's modulus were studied by a three point bending test. Effects were small; both electron radiation up to 5000 Mrad and gamma radiation up to 350 Mrad resulted in slight increases in both stress and modulus.

  8. M-C simulation of shielding effects of PE, LiH and graphite fibers under 1 MeV electrons and 20 MeV protons

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Shielding effects of different materials under 1 MeV electron and 20 MeV proton beams were simulated with Geant4 code. It was found that shielding effects of polyethylene and graphite fibers are much better than aluminum. Energy depositions in the phantom shielded by the materials are calculated, with the least energy deposition by graphite fiber shielding. The results show that graphite fibers are good radiation shielding material in space programs.

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

    International Nuclear Information System (INIS)

    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 600 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

  10. Program DDCS for nucleon and composite particle DDX of nucleon induced reactions up to tens of MeV

    International Nuclear Information System (INIS)

    DDCS is a program for calculating the neutron or proton induced reactions of medium-heavy nuclei in the incident energy range up to 50 MeV including 5 emission processes. This program is written in FORTAN-77 on microscopic computer 486. DDCS is constructed within the framework of optical model, generalized master equation of the exciton model, and the evaporation model. The effect of recoil nucleus is considered in this program. DDCS has been used to calculate reactions of n + 56Fe, n + 93Nb, P + 120Sn, P + 197Au, and P + 209Bi. Pretty good results in agreement with the experimental data were obtained

  11. Influence of 2 MeV electrons irradiation on gallium phosphide light-emitting diodes reverse currents

    International Nuclear Information System (INIS)

    Results of reverse electrophysical characteristics study of red and green LED's, initial and irradiated with 2 MeV electrons were given. It was found that reverse current was predominantly caused by carriers tunneling at Urev <- 9 V, and by the avalanche multiplication at Urev >- 13 V, in the range U = 9-13 V both mechanisms are available. Current increase at high voltage areas (Urev > 19 V) is limited by the base resistance of diode. In the case of significant reverse currents (I > 1 mA) irradiation of diodes leads to the shift of reverse current-voltage characteristics into the high voltages direction

  12. Variation of carrier concentration and interface trap density in 8MeV electron irradiated c-Si solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Bhat, Sathyanarayana, E-mail: asharao76@gmail.com; Rao, Asha, E-mail: asharao76@gmail.com [Department of Physics, Mangalore Institute of Technology and Engineering, Moodabidri, Mangalore-574225 (India); Krishnan, Sheeja [Department of Physics, Sri Devi Institute of Technology, Kenjar, Mangalore-574142 (India); Sanjeev, Ganesh [Microtron Centre, Department of Physics, Mangalore University, Mangalagangothri-574199 (India); Suresh, E. P. [Solar Panel Division, ISRO Satellite Centre, Bangalore-560017 (India)

    2014-04-24

    The capacitance and conductance measurements were carried out for c-Si solar cells, irradiated with 8 MeV electrons with doses ranging from 5kGy – 100kGy in order to investigate the anomalous degradation of the cells in the radiation harsh environments. Capacitance – Voltage measurements indicate that there is a slight reduction in the carrier concentration upon electron irradiation due to the creation of radiation induced defects. The conductance measurement results reveal that the interface state densities and the trap time constant increases with electron dose due to displacement damages in c-Si solar cells.

  13. Spectroscopic quadrupole moment of the 2+ state at 4.439 MeV in 12C

    International Nuclear Information System (INIS)

    The long standing predictions of α-cluster states in 12C plays an important role to account for the observed abundance of carbon in the Universe. The α-cluster configurations based on 02+ state (Hoyle state) at 7.65 MeV has considerable mixing with the 0+ ground state and decays to it via the 21+ excited state. Theoretically, the predictions of various model calculations such as isomorphic shell model, rotational models, α-particle model etc., are inconsistent with each other and suggest the ground state of 12C associate with deformation ranging from spherical to strong oblate

  14. Investigation of incomplete fusion dynamics from the measurement of angular distributions at E ≈ 88 MeV

    International Nuclear Information System (INIS)

    The present work has been carried out to provide some definite conclusions regarding ICF reaction dynamics below 10 MeV/nucleon energies. We have measured the angular distributions of evaporated residues produced in 12C + 175Lu system at ≈ 88 MeV energy. Moreover, this work is aimed to provide the new experimental data on angular distributions, which is not available in the literature to the best of our knowledge. This is a complementary experiment to support and strengthen the findings of Excitation Functions and Recoil Range Distribution measurements

  15. The influence of 175 MeV nickel ion irradiation on the electrical characteristics of power transistors (HF13)

    Science.gov (United States)

    Pushpa, N.; Praveen, K. C.; Gnana Prakash, A. P.; Naik, P. S.; Gupta, S. K.; Revannasiddaiah, D.

    2012-10-01

    The dc electrical characteristics of NPN RF power transistors were studied systematically before and after 175 MeV Ni13+ ion and Co-60 gamma irradiation in the dose range from 100 krad to 100 Mrad. The transistor parameters such as excess base current (ΔIB= IBpost-IBpre), dc current gain (hFE), and collector-saturation current (ICSat) were studied. The base current (IB) was found to increase significantly after irradiation and this in turn decreases the hFE of the transistors. Further, the output characteristics of the irradiated devices exhibit the decrease in the collector current at the saturation region (ICSat) with increase of radiation dose.

  16. Measurements of radiological data of some amino acids in the energy range 0.122-1.330MeV

    Science.gov (United States)

    Lokhande, Rajkumar M.; More, Chaitali V.; Surung, Bharat S.; Raut, Siddheshwar D.; Pawar, Pravina P.

    2016-05-01

    Radiological parameters such as μm, σt, σe, Zeff and Neff of amino acids, namely Lysine (C6H15N2O2), Histidine (C6H9N3O2) and Arginine (C6H15N4O2), were measured using NaI (Tl)-based gamma spectrometry. Radioactive sources used in the study are 57Co, 133Ba, 137Cs, 54Mn, 60Co and 22Na. Gamma ray transmission method in a narrow beam good geometry set up was used in the study. The measured data were compared against XCOM-based data. The agreement is within 2%.

  17. 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.

  18. Multipurpose 5-MeV linear induction accelerator

    Science.gov (United States)

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

    1984-06-01

    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, new technology was used to develop a magnetic pulse compression scheme that eliminates all spark gaps and exceeds requirements. The magnetic drive system are 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.

  19. Multipurpose 5-MeV linear induction accelerator

    International Nuclear Information System (INIS)

    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. 2 MeV linear accelerator for industrial applications

    Science.gov (United States)

    Smith, Richard R.; Farrell, Sherman R.

    1997-02-01

    RPC Industries has developed a high average power scanned electron beam linac system for medium energy industrial processing, such as in-line sterilization. The parameters are: electron energy 2 MeV; average beam current 5.0 mA; and scanned width 0.5 meters. The control system features data logging and a Man-Machine Interface system. The accelerator is vertically mounted, the system height above the floor is 3.4 m, and the footprint is 0.9×1.2 meter2. The typical processing cell inside dimensions are 3.0 m by 3.5 m by 4.2 m high with concrete side walls 0.5 m thick above ground level. The equal exit depth dose is 0.73 gm cm-2. Additional topics that will be reported are: throughput, measurements of dose vs depth, dose uniformity across the web, and beam power by calorimeter and magnetic deflection of the beam.

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

    CERN Multimedia

    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.

  2. CESAR, 2 MeV electron storage ring.

    CERN Multimedia

    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.

  3. Calculation of 14 MeV neutron transmission

    International Nuclear Information System (INIS)

    The possibility of using the 28 group constant system (28-GCS) for calculating the transport of neutrons with initial energy of 14 MeV in thermonuclear reactor blankets is studied. A blanket project suggested by the Oak Ridge National Laboratory is used as a test version to estimate applicability of the 28-GCS. Niobium is used in a blanket as a structural material. A mixture of lithium nuclides is used for tritium production. The results of blanket test calculation and the calculational results obtained using the 28-GCS from the UKNDL library are compared. The numerical 28-group calculation of blonket is carried out by means of the ROZ-6 and ROZ-9 codes but not by the Monte-Carlo method as compared with the test calculation. Time of the blanket calculation on the BESM-6 computer by means of the ROZ-9 code in 2P5 approximation using the 28-GCS amounts to 10 min. It is noted that to create effective codes for the numerical blanket calculation different calculational grids are necessary for different energy grups. The calculations carried out have shown the possibility of using the 28-group library of cross sections for the numerical solution of the neutron transport equation in estimating analysis of blankets

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

    International Nuclear Information System (INIS)

    A technique for simultaneous focusing and energy selection of high-current, MeV proton beams using radial, transient electric fields (107-1010 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 (δε/ε < 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 for medical applications such as

  5. 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

  6. Performance Results of the Modulator for the 100MeV Proton Linac

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Dae Il; Kwon, Hyeok Jung; Kim, Han Sung; Seol, Kyung Tae; Cho, Yong Sub [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2013-10-15

    The modulator for the 100MeV proton linac has been installed at KOMAC (Korea of Multi-purpose Accelerator Complex) site. The specification of modulator is 5.8MW peak power with 1.5ms pulse width, 60Hz repetition rate. There are total 4 sets of modulator for 100-MeV proton linac including 3-MeV RFQ, 20-MeV DTL and 100-MeV DTL. A modulator drives two or three sets of the klystrons simultaneously. After installation and du mmy test of 4 modulators, it has been operated for 100MeV proton linac. In this paper, the performance results of modulators for the 100MeV proton linac are presented. 4 modulators were installed and tested for the 100MeV proton linac. The modulator was measured to have about less than 1% droops at flat top for 500 us pulse by using pulse frequency modulation droop compensation method. The long term voltage variation measurement showed that the voltage increased up to 0.05% for 8 hours. In future, the voltage droop and variation of modulator should be continuously checked in the high repetition rate.

  7. Klystron High Power Operation for KOMAC 100-MeV Proton Linac

    Energy Technology Data Exchange (ETDEWEB)

    Seol, Kyung-Tae; Kim, Seong-Gu; Kwon, Hyeok-Jung; Kim, Han-Sung; Cho, Yong-Sub [KAERI, Daejeon (Korea, Republic of)

    2015-05-15

    The Korea multi-purpose accelerator complex (KOMAC) accelerator facility has a 100-MeV proton linac, five beam lines for 20-MeV beam utilization, and another five beam lines for 100-MeV beam utilization. The 100-MeV linac consists of a 50-keV proton injector based on a microwave ion source, a 3-MeV RFQ with a four-vane structure, and a 100-MeV DTL. Nine sets of 1MW klystrons have been operated for the 100-MeV proton linac. The klystron filament heating time was approximately 5700 hours in 2014, and RF operation time was 2863.4 hours. During the high power operation of the klystron, unstable RF waveforms appeared at the klystron output, and we have checked and performed cavity frequency adjustments, magnet and heater current, reflection from a circulator, klystron test without a circulator, and the frequency spectrum measurement. Nine sets of the klystrons have been operated for the KOMAC 100-MeV proton linac. The klystron filament heating time was 5700 hours and RF operation time was 2863.4 hours during the operation in 2014. Some klystrons have unstable RF waveforms at specific power level. We have checked and tested the cavity frequency adjustment, reflection from a circulator, high power test without a circulator, and frequency spectrum at the unstable RF.

  8. Initial Operation Results of the KOMAC 100MeV Proton Linac

    Energy Technology Data Exchange (ETDEWEB)

    Seol, Kyungtae; Kwon, Hyeokjung; Kim, Hansung; Kim, Daeil; Song, Younggi; Cho, Yongsub [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2014-05-15

    The Korea multi-purpose accelerator complex (KOMAC) accelerator facility has a 100-MeV proton linac, five beam lines for 20-MeV beam utilization, and another five beam lines for 100-MeV beam utilization. The 100-MeV linac consists of a 50-keV proton injector based on a microwave ion source, a 3-MeV RFQ with a four-vane structure, and a 100-MeV DTL. The KOMAC started to provide a proton beam to users on July 2013. A 20-MeV beam line and a 100-MeV beam line have been operated for beam service during the first year. In 2013, the proton linac had been operated for more than 2200 hours and beam service time was 432 hours approximately. The accumulated downtime during the first year in 2013 is 94.7 hours and there were some faults at utilities, high voltage modulators, and RF components. The KOMAC started to provide a proton beam to users on July 2013. The proton linac had been operated for more than 2200 hours and beam service time was 432 hours approximately. Accumulated downtime was 94.7 hours and availability was 82 %. The plan for beam power and operation time in 2014 is 10 kW and 2500 hours respectively.

  9. Response of BGO sectors to protons up to 170 MeV

    International Nuclear Information System (INIS)

    The response to monoenergetic protons of 24 cm long pyramidal BGO sectors, designed for a 4π spectrometer, was measured up to 173 MeV by scattering 200 MeV protons off a polyethylene target. The experimental results are compared with lower energy results and Monte Carlo calculations performed with a modified version of the GEANT code. (orig.)

  10. Two-color infrared FEL facility employing a 250-MeV Linac injector for SAGA synchrotron light source

    International Nuclear Information System (INIS)

    A two-color infrared free electron laser (FEL) facility is proposed, for which a 250-MeV linac type injector for the Saga synchrotron light source (SLS) is employed in FEL mode. The linac has two operation modes; short macropulse mode of 1 μa at 250 MeV for injection to the 1.4 GeV storage ring and long macropulse mode of 13 μs at 40 MeV for two-color infrared FEL facility, where simultaneous infrared (IR) and far-infrared (FIR) FELs are supplied for application researches by using two undulators for IR and FIR ranges like the FEL two-color FEL facility. The macropulse beam consists of a train of several ps, 0.6 nC micropulses (peak current 100A) repeating at 22.3125 or 89.25 MHz. The two-color FEL facility can supply high-power density photon beams of 10-GW/cm2 level covering an attractive wavelength range from 3.1 μm(0.4 eV) to 248 μm(0.005 eV) for scientific researches, bio-medical and industrial applications. The construction of the Saga SLS has been conducted by the Saga Prefectural Government as a six-year project started in 1998. The project is promoted by the Science and Technology Agency and the Saga Prefectural Government. The Saga SLS will be operated in 2004 to promote material science, bio-medical and industrial applications in Kyushu area. (author)

  11. Survey and Alignment of the 100MeV Linear Accelerator

    Energy Technology Data Exchange (ETDEWEB)

    Park, Bumsik; Kwon, Hyeokjung; Jang, Jiho; Kim, Hansung; Kim, Daeil; Cho, Yongsub [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2013-05-15

    The 100MeV linear accelerator was installed and under commissioning at the Gyeongju site. The 100MeV proton linac was developed by the KOMAC according to the survey work and the alignment process. 100MeV proton beam will be supplied to the users after the beam commissioning. KOMAC is developing a 100MeV high-duty-factor proton linac. Linac is composed with a 50keV proton injector, a 3MeV RFQ, DTL tanks and a beam dump. In this paper, the survey and alignment scheme are described. To install the accelerator, the align network was built and the survey work was accomplished. On the basis of the survey result, all of the accelerator components were installed in the tunnel with two laser trackers.

  12. Leptonic origin of the 100 MeV gamma-ray emission from the Galactic Centre

    CERN Document Server

    Malyshev, D; Neronov, A; Walter, R

    2015-01-01

    The Galactic Centre is a bright gamma-ray source with the GeV-TeV band spectrum composed of two distinct components in the 1-10 GeV and 1-10 TeV energy ranges. The nature of these two components is not clearly understood. We investigate the gamma-ray properties of the GC in order to clarify the origin of the observed emission. We report imaging, spectral and timing analysis of the data of 74 months of observations of the Galactic Centre by FERMI/LAT gamma-ray telescope complemented by the sub-MeV data from ~10 years of INTEGRAL/PICsIT observations. We find that in the GeV band the Galactic Centre is spatially consistent with a point source. The 3 sigma upper limit on its radius is 0.13 degree. The spectrum of the source in the 100 MeV energy range does not have a characteristic turnover which would point to the pion decay origin of the signal. Instead, the source spectrum is consistent with a model of inverse Compton scattering by high-energy electrons. In such a model, the GeV bump in the spectrum originates...

  13. 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.

  14. Suzaku Observations of Extreme MeV Blazar SWIFT J0746.3+2548

    CERN Document Server

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

    2008-01-01

    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 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. W...

  15. X-ray generation by MeV electrons in silicon: temperature, tilt, and thickness dependence

    International Nuclear Information System (INIS)

    When relativistic electrons strike a single crystal target, sharp peaks are observed in the x-ray spectrum generated. One type of radiation, called coherent bremsstrahlung, results from coherent electron scattering by atoms arranged on the crystal lattice. The other type of radiation is channeling radiation. The electrons channeling near major crystal axes enter quantized orbits and emit x-ray photons as a consequence of transitions between orbits. Observations of channeling and coherent bremsstrahlung spectra using 2 to 3 MeV electrons incident on targets 1 and 3 μm thick are described. Large changes in channeling x-ray energies and intensities are observed over a narrow range of temperature from room temperature to 20000C. There are no such large changes in the coherent bremsstrahlung spectra under the same conditions. Intensity measurements over a range of thicknesses for both types of radiation are reported. Finally, changes in the energy of the highest energy channeling peak are found as the channeling axis is tilted away from the electron beam

  16. High-sensitivity measurements of the excitation function for Bhabha scattering at MeV energies

    International Nuclear Information System (INIS)

    Using a monochromatic e+ beam scattered on a Be foil and a high-resolution detector device, the excitation function for elastic e+e- scattering was measured with a statistical accuracy of 0.25% in 1.4 keV steps in the c.m.-energy range between 770 keV and 840 keV (1.79 - 1.86 MeV/c2) at c.m. scattering angles between 800 and 1000 (FWHM). Within the experimental sensitivity of 0.5 b.eV/sr (c.m.) for the energy-integrated differential cross section no resonances were observed (97% CL). From this limit we infer that a hypothetical spinless resonant state should have a width of less than 1.9 meV corresponding to a lifetime limit of 3.5x10-13 s. This limit establishes the most stringent bound for new particles in this mass range derived from Bhabha scattering and is independent of assumptions about the internal structure of the hypothetical particles. Less sensitivite limits were, in addition, derived around 520 keV c.m. energy (≅ 1.54 MeV/c2) from an investigation with a thorium and a mylar foil as scatterers. (orig.)

  17. 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...

  18. Measurement of charge symmetry breaking in np elastic scattering at 350 MeV

    International Nuclear Information System (INIS)

    TRIUMF experiment 369, a measurement of charge symmetry breaking in np elastic scattering at 350 MeV, has completed data taking. Scattering asymmetries were measured with a polarized (unpolarized) neutron beam incident on an unpolarized (polarized) frozen spin target. Coincident scattered neutrons and recoil protons were detected by a mirror symmetric detection system in the center-of-mass angle range from 50 deg - 90 deg. A preliminary result for the difference of the zero-crossing angles, where analyzing powers cross zero, is Δθcm = 0.445 deg ± 0.054 deg (stat.) ± 0.051 deg (syst.) based on fits over the angle range 53.4 deg ≤ θcm ≤ 86.9 deg. The difference of the analyzing powers ΔA ≡ An - Ap, where the subscripts denote polarized nucleons, was deduced with dA/dθcm = (-1.35 ± 0.05) x 10-2deg-1 to be [60 ± 7(stat.) ± 7(syst.) ± 2(syst.)] x 10-4. (author). 11 refs., 6 figs

  19. 80 MeV C6+ ion irradiation effects on the DC electrical characteristics of silicon NPN power transistors

    Science.gov (United States)

    Bharathi, M. N.; Pushpa, N.; Vinayakprasanna, N. H.; Prakash, A. P. Gnana

    2016-05-01

    The total dose effects of 80 MeV C6+ ions on the DC electrical characteristics of Silicon NPN rf power transistors have been studied in the dose range of 100 krad to 100 Mrad. The SRIM simulation was used to understand the energy loss and range of the ions in the transistor structure. The different electrical parameters such as Gummel characteristics, excess base current (ΔIB = IBpost - IBpre), dc forward current gain (hFE), transconductance (gm), displacement damage factor (K) and output characteristics (VCE-IC) were studied systematically before and after irradiation. The significant degradation in base current (IB) and hFE was observed after irradiation. Isochronal annealing study was conducted on the irradiated transistors to analyze the recovery in different electrical parameters. These results were compared with 60C0 gamma irradiation results in the same dose range.

  20. Charge-changing-cross-section measurements of $^{12-16}$C at around $45A$ MeV and development of a Glauber model for incident energies $10A-2100A$ MeV

    CERN Document Server

    Tran, D T; Nguyen, T T; Tanihata, I; Aoi, N; Ayyad, Y; Chan, P Y; Fukuda, M; Hashimoto, T; Hoang, T H; Ideguchi, E; Inoue, A; Kawabata, T; Khiem, L H; Lin, W P; Matsuta, K; Mihara, M; Momota, S; Nagae, D; Nguyen, N D; Nishimura, D; Ozawa, A; Ren, P P; Sakaguchi, H; Tanaka, J; Takechi, M; Terashima, S; Wada, R; Yamamoto, T

    2016-01-01

    We have measured for the first time the charge-changing cross sections ($\\sigma_{\\text{CC}}$) of $^{12-16}$C on a $^{12}$C target at energies below $100A$ MeV. To analyze these low-energy data, we have developed a finite-range Glauber model with a global parameter set within the optical-limit approximation which is applicable to reaction cross section ($\\sigma_{\\text{R}}$) and $\\sigma_{\\text{CC}}$ measurements at incident energies from 10$A$ to $2100A$ MeV. Adopting the proton-density distribution of $^{12}$C known from the electron-scattering data, as well as the bare total nucleon-nucleon cross sections, and the real-to-imaginary-part ratios of the forward proton-proton elastic scattering amplitude available in the literatures, we determine the energy-dependent slope parameter $\\beta_{\\rm pn}$ of the proton-neutron elastic differential cross section so as to reproduce the existing $\\sigma_{\\text{R}}$ and interaction-cross-section data for $^{12}$C+$^{12}$C over a wide range of incident energies. The Glauber...

  1. 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.

  2. 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.

  3. 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. PMID:27587107

  4. Degradation of the charge collection efficiency of an n-type Fz silicon diode subjected to MeV proton irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Barbero, Nicolò; Forneris, Jacopo [Physics Department, NIS Research Centre and CNISM, University of Torino, Via P. Giuria 1, 10250 Torino (Italy); Grilj, Veljko; Jakšić, Milko [Department for Experimental Physics, Ruđer Bošković Institute, P.O. Box 180, 10002 Zagreb (Croatia); Räisänen, Jyrki [Department of Physics, University of Helsinki, P.O. Box 43, 00014 Helsinki (Finland); Simon, Aliz [International Atomic Energy Agency, Vienna International Centre, P.O. Box 100, 1400 Vienna (Austria); Institute of Nuclear Research of the Hungarian Academy of Sciences (ATOMKI), Debrecen (Hungary); Skukan, Natko [Department for Experimental Physics, Ruđer Bošković Institute, P.O. Box 180, 10002 Zagreb (Croatia); Vittone, Ettore, E-mail: ettore.vittone@unito.it [Physics Department, NIS Research Centre and CNISM, University of Torino, Via P. Giuria 1, 10250 Torino (Italy)

    2015-04-01

    Highlights: •Study of charge collection efficiency degradation (CCE) in Si diode due to MeV H irradiation. •CCE evaluated by micro-IBIC using 4.5 MeV Li ions to probe the damaged region. •Generation of H-donors, which perturb the electrostatic properties of the diode. -- Abstract: We present the analysis of the charge collection efficiency (CCE) degradation of float zone grown n-type silicon detectors irradiated with 1.3, 2.0 and 3.0 MeV protons. The analysis was carried out by irradiating small regions (50 × 50 μm{sup 2}) with a proton microbeam at fluences ranging from 10{sup 11} to 4·10{sup 12} ions/cm{sup 2} and probing the effect of irradiation by measuring the 4.5 MeV Li ion induced charge in full depletion conditions. The CCE degradation as function of the proton fluence shows an unexpected deviation from the linear behavior predicted by the Shockley–Read–Hall model of carrier recombination. The build-up of excess hydrogen related donors due to proton irradiations is suggested to be the cause of a significant perturbation of the electrostatic properties of the diode, which drastically change the electron trajectories and hence the induced charge mechanism.

  5. Tracking and imaging gamma-ray experiment (TIGRE) for 300-keV to 100-MeV gamma-ray astronomy

    Science.gov (United States)

    Tumer, Tumay O.; Bhattacharya, Dipen; Blair, Scott C.; Case, Gary; Dixon, David D.; Liu, Chia-Ling; O'Neill, Terrence J.; White, R. Stephen; Zych, Allen D.

    1994-09-01

    The Tracking and Imaging Gamma-Ray Experiment (TIGRE) uses multilayers of silicon strip detectors both as a gamma-ray converter and to track Compton recoil electrons and positron-electron pairs. The silicon strip detectors also measure the energy losses of these particles. For Compton events, the direction and energy of the Compton scattered gamma ray are measured with arrays of small CsI(TI)-photodiode detectors so that an unique direction and energy can be found for each incident gamma ray. The incident photon direction for pair events is found from the initial pair particle directions. TIGRE is the first Compton telescope with a direct imaging capability. With a large (pi) -steradian field-of-view, it is sensitive to gamma rays from 0.3 to 100 MeV with a typical energy resolution of 3% (FWHM) and a 1-(sigma) angular resolution of 40 arc-minutes at 2 MeV. A small balloon prototype instrument is being constructed that has a high absolute detection efficiency of 8% over the full energy range and a sensitivity of 10 milliCrabs for an exposure of 500,000 s. TIGRE's innovative design also uses the polarization dependence of the Klein-Nishina formula for gamma-ray source polarization measurements. The telescope will be described in detail and new results from measurements at 0.5 MeV and Monte Carlo calculations from 1 to 100 MeV will be presented.

  6. Characterization of PARIS LaBr$_3$(Ce)-NaI(Tl) phoswich detectors upto $E_\\gamma$ $\\sim$ 22 MeV

    CERN Document Server

    Ghosh, C; Pillay, R G; K., Anoop; Dokania, N; Pal, Sanjoy; Pose, M S; Mishra, G; Rout, P C; Kumar, Suresh; Pandit, Deepak; Mondal, Debasish; Pal, Surajit; Banerjee, S R; Napiorkowski, Paweł J; Dorvaux, Oliver; Kihel, S; Mathieu, C; Maj, A

    2016-01-01

    In order to understand the performance of the PARIS (Photon Array for the studies with Radioactive Ion and Stable beams) detector, detailed characterization of two individual phoswich (LaBr$_3$(Ce)-NaI(Tl)) elements has been carried out. The detector response is investigated over a wide range of $E_{\\gamma}$ = 0.6 to 22.6 MeV using radioactive sources and employing $^{11}B(p,\\gamma)$ reaction at $E_p$ = 163 keV and $E_p$ = 7.2 MeV. The linearity of energy response of the LaBr$_3$(Ce) detector is tested upto 22.6 MeV using three different voltage dividers. The data acquisition system using CAEN digitizers is set up and optimized to get the best energy and time resolution. The energy resolution of $\\sim$ 2.1% at $E_\\gamma$ = 22.6~MeV is measured for configuration giving best linearity upto high energy. Time resolution of the phoswich detector is measured with $^{60}$Co source after implementing CFD algorithm for the digitized pulses and is found to be excellent (FWHM $\\sim$ 315~ps). In order to study the effect...

  7. 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...

  8. The spectrum of isotropic diffuse gamma-ray emission between 100 MeV and 820 GeV

    CERN Document Server

    Ackermann, M; Albert, A; Atwood, W B; Baldini, L; Ballet, J; Barbiellini, G; Bastieri, D; Bechtol, K; Bellazzini, R; Bissaldi, E; Blandford, R D; Bloom, E D; Bottacini, E; Brandt, T J; Bregeon, J; Bruel, P; Buehler, R; Buson, S; Caliandro, G A; Cameron, R A; Caragiulo, M; Caraveo, P A; Cavazzuti, E; Cecchi, C; Charles, E; Chekhtman, A; Chiang, J; Chiaro, G; Ciprini, S; Claus, R; Cohen-Tanugi, J; Conrad, J; Cuoco, A; Cutini, S; D'Ammando, F; de Angelis, A; de Palma, F; Dermer, C D; Digel, S W; Silva, E do Couto e; Drell, P S; Favuzzi, C; Ferrara, E C; Focke, W B; Franckowiak, A; Fukazawa, Y; Funk, S; Fusco, P; Gargano, F; Gasparrini, D; Germani, S; Giglietto, N; Giommi, P; Giordano, F; Giroletti, M; Godfrey, G; Gomez-Vargas, G A; Grenier, I A; Guiriec, S; Gustafsson, M; Hadasch, D; Hayashi, K; Hays, E; Hewitt, J W; Ippoliti, P; Jogler, T; Jóhannesson, G; Johnson, A S; Johnson, W N; Kamae, T; Kataoka, J; Knödlseder, J; Kuss, M; Larsson, S; Latronico, L; Li, J; Li, L; Longo, F; Loparco, F; Lott, B; Lovellette, M N; Lubrano, P; Madejski, G M; Manfreda, A; Massaro, F; Mayer, M; Mazziotta, M N; McEnery, J E; Michelson, P F; Mitthumsiri, W; Mizuno, T; Moiseev, A A; Monzani, M E; Morselli, A; Moskalenko, I V; Murgia, S; Nemmen, R; Nuss, E; Ohsugi, T; Omodei, N; Orlando, E; Ormes, J F; Paneque, D; Panetta, J H; Perkins, J S; Pesce-Rollins, M; Piron, F; Pivato, G; Porter, T A; Rainò, S; Rando, R; Razzano, M; Razzaque, S; Reimer, A; Reimer, O; Reposeur, T; Ritz, S; Romani, R W; Sánchez-Conde, M; Schaal, M; Schulz, A; Sgrò, C; Siskind, E J; Spandre, G; Spinelli, P; Strong, A W; Suson, D J; Takahashi, H; Thayer, J G; Thayer, J B; Tibaldo, L; Tinivella, M; Torres, D F; Tosti, G; Troja, E; Uchiyama, Y; Vianello, G; Werner, M; Winer, B L; Wood, K S; Wood, M; Zaharijas, G; Zimmer, S

    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 sig...

  9. 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...

  10. Further Analysis of Neutron Double-Differential Cross Section of n + 16O at 14.1 MeV and 18 MeV

    Institute of Scientific and Technical Information of China (English)

    DUAN Jun-Feng; YAN Yu-Liang; WANG Ji-Min; SUN Xiao-Jun; ZHANG Jing-Shang

    2005-01-01

    By using a new reaction model for light nuclei, the double-differential cross section of total outgoing neutron with LUNF code for n + 16O reactions at En = 14.1 MeV and 18 MeV have been calculated and analyzed. In this paper the opened reaction channels, which have contribution to emitting the neutrons, are listed in detail. To improve the fitting results the direct inelastic scattering mechanism is involved. The calculating results agree fairly well with the experimental data at En = 14.1 MeV and the deviation from calculated results and experimental data in low energy region at En = 18 MeV has been analyzed. Since the possibility of 5He has been affirmed theoretically [J.S. Zhang,Sci. Chin. G 47 (2004) 137], so 5He emission from n + 16O reaction is taken into account, which plays an important role at the region of the outgoing neutron energy εn < 3 MeV in total outgoing neutron energy-angular spectrum. The calculated results indicate that the pre-equilibrium mechanism dominates the whole reaction processes, and the recoil effect in light nuclear reactions is essentially important.

  11. Studies of range and straggling of muons in metals by the projected range imaging (PRI) technique

    Energy Technology Data Exchange (ETDEWEB)

    Shiroka, Toni; Bucci, Cesare E-mail: cesare.bucci@fis.unipr.it; De Renzi, Roberto; Guidi, Germano; Eaton, Gordon; King, Philip; Scott, Christopher

    1999-05-01

    A new {mu}SR method for directly imaging the implantation depth distribution of positive muons in metals (Projected Range Imaging: PRI) is presented and the results obtained from several experiments are reported. Strong magnetic field gradients inside a metallic film are produced by driving an electric current in it: spin polarized muons stopped in the film have Larmor precession frequencies proportional to the implantation depth. Generation of field gradients, advantages and features of the method are discussed. For muon energy in the MeV range the results are compared with Monte Carlo simulations and with experimental results obtained by using the conventional moderator curve method. Applications to range and straggling studies with epithermal muons are also envisaged. These future extensions will allow a better understanding of the energy loss mechanisms in the previously inaccessible very low energy range.

  12. 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)

  13. Angular distribution of 4.43-MeV γ-rays produced in inelastic scattering of 14.1-MeV neutrons by 12C nuclei

    Science.gov (United States)

    Bystritsky, V. M.; Grozdanov, D. N.; Zontikov, A. O.; Kopach, Yu. N.; Rogov, Yu. N.; Ruskov, I. N.; Sadovsky, A. B.; Skoy, V. R.; Barmakov, Yu. N.; Bogolyubov, E. P.; Ryzhkov, V. I.; Yurkov, D. I.

    2016-07-01

    The work is devoted to measuring the angular distribution of 4.43-MeV γ-rays produced in inelastic scattering of 14.1-MeV neutrons by 12C nuclei. A portable ING-27 neutron generator (designed and fabricated at VNIIA, Moscow) with a built-in 64-pixel silicon α-detector was used as a source of tagged neutrons. The γ-rays of characteristic nuclear radiation from 12C were detected with a spectrometric system that consisted of 22 γ-detectors based on NaI(Tl) crystals arranged around the carbon target. The measured angular distribution of 4.43-MeV γ-rays is analyzed and compared with the results of other published experimental works.

  14. Luminescence properties of 100 MeV swift Si{sup 7+} ions irradiated nanocrystalline zirconium oxide

    Energy Technology Data Exchange (ETDEWEB)

    Lokesha, H.S. [Physics R & D Centre, PES Institute of Technology, BSK 3rd Stage, Bangalore, 560 085 (India); Nagabhushana, K.R., E-mail: bhushankr@gmail.com [Physics R & D Centre, PES Institute of Technology, BSK 3rd Stage, Bangalore, 560 085 (India); Singh, Fouran [Inter University Accelerator Centre, Aruna Asaf Ali Marg, New Delhi, 110 067 (India)

    2015-10-25

    Nanocrystalline zirconium oxide (ZrO{sub 2}) has been synthesized by combustion technique. The X-ray diffraction (XRD) pattern of ZrO{sub 2} confirms the monoclinic phase. The average crystallite sizes are estimated using Scherrer's formula and found to be ∼35 nm. Surface morphology and elemental composition of the ZrO{sub 2} is analyzed using the field emission scanning electron microscope (FESEM) equipped with Energy dispersive x-ray analysis (EDX). ZrO{sub 2} pellets are irradiated with 100 MeV swift Si{sup 7+} heavy ions in the fluence range of 1 × 10{sup 10}–1 × 10{sup 14} ions cm{sup −2}. The broad photoluminescence (PL) emission with peak at ∼ 466 nm is observed and attributed to F-centers. Thermoluminescence (TL) glow curves of ion irradiated samples reveal a well resolve peak at ∼ 418 K (T{sub m1}) and an unresolved peak at ∼ 502 K (T{sub m2}). TL intensity increases up to 3 × 10{sup 11} ions cm{sup −2} and then TL intensity decreases as increase in fluence. TL parameters of ion irradiated ZrO{sub 2} samples are described by general order kinetics. - Graphical abstract: Thermoluminescence glow curves of 100 MeV swift Si{sup 7+} ion irradiated ZrO{sub 2}. - Highlights: • Single phase of ZrO{sub 2} synthesized by combustion technique. • Sample irradiated with 100 MeV Si{sup 7+} ions for various fluence. • Highest PL and TL response at same fluence due to defect concentration. • New TL glow peak appear at 455 K for above fluence 1 × 10{sup 11} ions cm{sup −2}.

  15. 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...

  16. Comparison of bactericidal efficiency of 7.5 MeV X-rays, gamma-rays, and 10 MeV e-beams

    Science.gov (United States)

    Song, Beom-Seok; Lee, Yunjong; Moon, Byeong-Geum; Go, Seon-Min; Park, Jong-Heum; Kim, Jae-Kyung; Jung, Koo; Kim, Dong-Ho; Ryu, Sang-Ryeol

    2016-08-01

    This study was performed to verify the feasibility of 7.5 MeV X-rays for food pasteurization through a comparison of the bactericidal efficiency with those of other sources for selected bacterial pathogens. No significant differences were observed between the overall bactericidal efficiency for beef-inoculated pathogens based on the uncertainty of the absorbed dose and variations in bacterial counts. This result supported that all three irradiation sources were effective for inactivation of food-borne bacteria and that 7.5 MeV X-rays may be used for food pasteurization.

  17. Low-energy theorems for nucleon-nucleon scattering at $M_{\\pi}=450$ MeV

    CERN Document Server

    Baru, V; Filin, A A

    2016-01-01

    We apply the low-energy theorems to analyze the recent lattice QCD results for the two-nucleon system at a pion mass of $M_\\pi\\simeq 450$ MeV obtained by the NPLQCD collaboration. We find that the binding energies of the deuteron and dineutron are inconsistent with the low-energy behavior of the corresponding phase shifts within the quoted uncertainties and vice versa. Using the binding energies of the deuteron and dineutron as input, we employ the low-energy theorems to predict the phase shifts and extract the scattering length and the effective range in the $^3S_1$ and $^1S_0$ channels. Our results for these quantities are consistent with those obtained by the NPLQCD collaboration from effective field theory analyses but are in conflict with their determination based on the effective-range approximation.

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

    Directory of Open Access Journals (Sweden)

    Neelam Pahwa

    2011-01-01

    Full Text Available 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. Intensity of these modes decreased with increase in ion fluence. UV-transmission showed pronounced interference fringes, indicating a good quality of the films. The bandgap was found to increase in the range 1.4-1.75 eV with increase in fluence.

  19. 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.

  20. Simulation of a Compact Neutron Source with 13MeV Cyclotron

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jeong ho; Lee, Seung Wook [Pusan National University, Busan (Korea, Republic of); Moon, Myung Kook; Hur, Min Goo; Kim, GTae Joo [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2015-10-15

    In this presentation, we calculated neutron flux and neutron energy spectrum in 13MeV Cyclotron. Additionally, we found suitable design of target, metal layer and cooling system. We could find an opportunity about neutron radiography system by using cyclotron. For neutron radiography, fast neutron have to shift thermal range. We need to study this direction. Monte Carlo code is not almighty, so we need to refer to this data. This presentation can be first step to prove to operate KIRAMS-13 in Pusan National University. Proton accelerator is valuable for neutron generator for neutron generator. This paper is aim to verify possibility to get neutron from KIRAMS-13, which is located in Pusan national university and optimize neutron target. To get nice quality of neutrons, it is necessary to study neutron flux and neutron energy spectrum. In order to get neutronic data, the simulation is conducted by using Monte Carlo method with Geant4 code. Regarding target design, which is consist of Beryllium target, metal layer and cooling system, simulation is conducted below many different combinations.

  1. Thermoluminescence response of flat optical fiber subjected to 9 MeV electron irradiations

    International Nuclear Information System (INIS)

    We describe the efforts of finding a new thermoluminescent (TL) media using pure silica flat optical fiber (FF). The present study investigates the dose response, sensitivity, minimum detectable dose and glow curve of FF subjected to 9 MeV electron irradiations with various dose ranges from 0 Gy to 2.5 Gy. The above-mentioned TL properties of the FF are compared with commercially available TLD-100 rods. The TL measurements of the TL media exhibit a linear dose response over the delivered dose using a linear accelerator. We found that the sensitivity of TLD-100 is markedly 6 times greater than that of FF optical fiber. The minimum detectable dose was found to be 0.09 mGy for TLD-100 and 8.22 mGy for FF. Our work may contribute towards the development of a new dosimeter for personal monitoring purposes. - Highlights: • TL performance of pure silica flat optical fiber (FF) and TLD-100 rod to electron. • TL glow curve with a single prominent peak between 230 and 255 °C. • The sensitivity of FF is approximately 16% than TLD-100. • The minimum detectable dose was 0.09 mGy for TLD-100 rod and 8.22 mGy for FF

  2. Photocatalytic activity of 6.5 MeV electron-irradiated ZnO nanorods

    Science.gov (United States)

    Sapnar, K. B.; Ghule, L. A.; Bhoraskar, S. V.; Garadkar, K. M.; Dhole, S. D.; Bhoraskar, V. N.

    2012-04-01

    The microwave-synthesized zinc-oxide (ZnO) nanonorods of average length of ∼ 1500 nm and diameter ∼ 100 nm were irradiated with 6.5 meV electrons. From sample to sample, the electron fluence was varied over the range 5×1014 to 2.5×1015 e-cm-2. The pre- and post-electron-irradiated ZnO nanorods were characterized by X-ray diffraction, UV-VIS, EDAX, scanning electron microscopy, transmission electron microscopy, and BET methods. The results show that after electron irradiation, the ZnO nanorods could retain the hexagonal phase with the wurtzite structure; however, the average length of the ZnO nanorods reduced to ∼ 800 nm. Moreover, the oxygen atoms from a fraction of ZnO molecules were dislodged, and the process contributed to the formation of Zn-ZnO mixed phase, with increased zinc to oxygen ratio. In the photo-degradation of Rhodamine-B, a significant enhancement in the photocatalytic activity of the electron-irradiated ZnO nanorods was observed. This could be attributed to the induced defects, reduced dimensions, and increased surface area of the ZnO nanorods, in addition to the formation of the Zn-ZnO phase. All these could collectively contribute to the effective separation of the photogenerated electrons from the holes on the ZnO nanorods, and therefore enhance the photocatalytic activity under UV exposure.

  3. Entropy in central Au+Au reactions between 100 and 400{ital A} MeV

    Energy Technology Data Exchange (ETDEWEB)

    Dzelalija, M.; Cindro, N.; Basrak, Z.; Caplar, R.; Hoelbling, S.; Bini, M.; Maurenzig, P.R.; Olmi, A.; Pasquali, G.; Poggi, G.; Taccetti, N.; Cerruti, C.; Coffin, J.P.; Dona, R.; Fintz, P.; Guillaume, G.; Houari, A.; Jundt, F.; Kuhn, C.; Rami, F.; Tezkratt, R.; Wagner, P.; Biegansky, J.; Kotte, R.; Moesner, J.; Neubert, W.; Wohlfarth, D.; Alard, J.P.; Amouroux, V.; Bastid, N.; Berger, L.; Belayev, I.; Boussange, S.; Buta, A.; Dupieux, P.; Eroe, J.; Fodor, Z.; Fraysse, L.; Gobbi, A.; Herrmann, N.; Hildenbrand, K.D.; Ibnouzahir, M.; Kecskemeti, J.; Koncz, P.; Korchagin, Y.; Kraemer, M.; Lebedev, A.; Legrand, I.; Manko, V.; Mgebrishvili, G.; Moisa, D.; Montarou, G.; Montbel, I.; Pelte, D.; Petrovici, M.; Pras, P.; Ramillien, V.; Reisdorf, W.; Schuell, D.; Seres, Z.; Sikora, B.; Simion, V.; Smolyankin, S.; Sodan, U.; Trzaska, M.; Vasiliev, M.A.; Wessels, J.P.; Wienold, T.; Wilhelmi, Z.; Zhilin, A.V. [Institute for Physics and Nuclear Engineering, Bucharest (Romania)]|[Central Research Institute for Physics, Budapest (Hungary)]|[Laboratoire de Physique Corpusculaire, Clermont-Ferrand (France)]|[Gesellschaft fuer Schwerionenforschung, Darmstadt (Germany)]|[I.N.F.N. and University of Florence, Florence (Italy)]|[Physikalisches Institut der Universitaet Heidelberg, Heidelberg (Germany)]|[Institute for Experimental and Theoretical Physics, Moscow (Russian Federation)]|[Kurchatov Institute for Atomic Energy, Moscow (Russian Federation)]|[Forschungzentrum, Rossendorf (Germany)]|[Department of Physics, University of Split, Split (Croatia)]|[Centre de Recherches Nucleaires, IN2P3-CNRS, Universite Louis Pasteur, Strasbourg (France)]|[Institute of Experimental Physics, Warsaw University, Warsaw (Poland)]|[Rudjer Boskovic Institute, Zagreb (Croatia)

    1995-07-01

    The ratio of the total charge bound in fragments with {ital Z} between 2 and 15 to the hydrogen yield, ({ital tsum}{sub 2}{sup 15}{ital M}{sub {ital i}{ital Z}{ital i}})/{ital M}{sub {ital H}}, has been measured, and the neutron-to-proton ratio {ital n}/{ital p} has been estimated from the data of central Au + Au reactions between 100 and 400{ital A} MeV, measured with the phase I setup of the detector system FOPI and GSI, Darmstadt, in the polar-angle range between 7{degree} and 30{degree}. These two quantities were used to determine the entropy per nucleon {ital S}/{ital A} by comparing them with the predictions of the FREESCO code. The analysis allows the simulataneous extraction of the values of the baryonic entropy, temperature, and collective flow. The extracted values are in good agreement with the values obtained in earlier FOPI studies, and, for the baryonic entropy, with recent hydrodynamic calculations.

  4. 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.)

  5. 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...

  6. 50 MeV lithium ion beam irradiation effects in poly vinylidene fluoride (PVDF) polymer

    Indian Academy of Sciences (India)

    A K Srivastava; H S Virk

    2000-12-01

    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 1.27 × 1011 to 2.15 × 1013 ions cm–2 have been used to study dose effects of irradiation in PVDF. The recorded UV-visible spectra clearly shows five characteristic peaks at 315, 325, 360, 425 and 600 nm. Due to irradiation, the optical absorption initially decreases but then increases with higher fluences. In the FT-IR spectra, no appreciable change has been observed after irradiation, indicating that this polymer is chemically stable. There is exponential increase in admittance with log of frequency but the effect of irradiation is not quite appreciable. The value of tan and relaxation frequency are changed appreciably due to irradiation. The diffraction pattern of PVDF indicates that this polymer is in semi-crystalline form; a decrease in the crystallinity and crystallite size has been observed due to irradiation.

  7. An analysis of 100 MeV F{sup 8+} ion and 50 MeV Li{sup 3+} ion irradiation effects on silicon NPN rf power transistors

    Energy Technology Data Exchange (ETDEWEB)

    Pushpa, N., E-mail: pushpa_gnp@hotmail.co [Department of Studies in Physics, University of Mysore, Manasagangotri, Mysore 570 006 (India); Praveen, K.C.; Gnana Prakash, A.P. [Department of Studies in Physics, University of Mysore, Manasagangotri, Mysore 570 006 (India); Prabhakara Rao, Y.P. [Bharath Electronics Limited, Jalahalli, Bangalore 580 097 (India); Tripati, Ambuj [Inter University Accelerator Centre, Aruna Asaf Ali Marg, New Delhi 110 067 (India); Revannasiddaiah, D. [Department of Studies in Physics, University of Mysore, Manasagangotri, Mysore 570 006 (India)

    2010-08-21

    The dc characteristics exhibited by NPN power transistors are studied systematically before and after irradiation by 100 MeV F{sup 8+} ions and 50 MeV Li{sup 3+} ions in the dose range of 100 krad to 100 Mrad. The transistor parameters such as excess base current ({Delta}I{sub B}=I{sub Bpost}-I{sub Bpre}), dc current gain (h{sub FE}), transconductance (g{sub m}), and collector-saturation current (I{sub Csat}) were studied before and after irradiation. The damage factors (k) for h{sub FE} were calculated for ion irradiated transistors using Messenger-Spratt relation. The base current (I{sub B}) was found to increase significantly after ion irradiation and this in turn decreases the h{sub FE} of the transistors. The g{sub m} decreases significantly after ion irradiation. Moreover, the output characteristics of irradiated devices also show that the collector current (I{sub C}) in the saturation region (I{sub Csat}) decrease with increase in ion dose. The observed change in these characteristics may be due to the ion induced generation-recombination (G-R) centers in emitter-base (E-B) spacer oxide and the ion induced point defects and their complexes in the transistor structure.

  8. Neutron capture between 5 keV and 3 MeV

    International Nuclear Information System (INIS)

    Neutron capture cross-sections over a wide range of mass number are being measured for neutron energies between about 5 keV and 3 MeV. The nuclei studied to date are 41K, 85Rb, 86Sr, 87Rb, 89Y, 98Mo, 139La, 141Pr,158Gd, 170Er, 175Lu, and 176Yb. The experimental technique used is the activation method, in which the radioactive capture product formed in the neutron bombardment is measured by beta or gamma counting, and the counters are calibrated against a 4π-beta counter. Monoenergetic neutrons are produced by bombarding lithium or tritium targets with protons from the 4-MeV Van de Graaff accelerator. The neutron intensity is measured with a fission chamber, which counts fissions in a thin deposit of 235U. The data are compared with calculations based upon the statistical model of uncorrelated and non-interfering compound nuclear states. This model, which yields the energy averages of resonant or fluctuating compound nuclear cross-sections, was first used to calculate capture cross-sections by Lane and Lynn, and has been developed further by Moldauer. The calculations take into account the variation of radiation width and level density with excitation energy and spin of the compound nucleus, and include the competition of compound elastic and inelastic scattering and the variation of neutron widths from level to level (Porter-Thomas distribution). Neutron widths were calculated from optical model transmission coefficients, with the parameters chosen according to the spherical optical model of Moldauer. Another phenomenon is considered in the calculations. If the compound state, de-exciting through a gamma-ray cascade, ends its de-excitation in a low-lying level of (Z, A + 1), the event is radiative capture, as measured experimentally. If, however, after a gamma-ray decay, the compound system is at an excitation energy above the neutron emission threshold, the gamma-ray cascade may be ended by neutron emission, and the process does not contribute to the capture

  9. Induced photonuclear interaction by Rhodotron-TT200 10 MeV electron beam

    Indian Academy of Sciences (India)

    Farshid Tabbakh; Mojtaba Mostajab Aldaavati; Mahdieh Hoseyni; Khadijeh Rezaee Ebrahim Saraee

    2012-02-01

    In this paper the photonuclear interaction induced by 10 MeV electron beam generating high-intensity neutrons is studied. Since the results depend on the target material, the calculations are performed for Pb, Ta and W targets which have high , in a simple geometry. MCNPX code has been used to simulate the whole process. Also, the results of photon generation has been compared 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.

  10. 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.

  11. Design study for a 500 MeV proton synchrotron with CSNS linac as an injector

    Science.gov (United States)

    Huang, Liang-Sheng; Ji, Hong-Fei; Wang, Sheng

    2016-09-01

    Using the China Spallation Neutron Source (CSNS) linac as the injector, a 500 MeV proton synchrotron is proposed for multidisciplinary applications, such as biology, material science and proton therapy. The synchrotron will deliver proton beam with energy from 80 MeV to 500 MeV. A compact lattice design has been worked out, and all the important beam dynamics issues have been investigated. The 80 MeV H- beam is stripped and injected into the synchrotron by using multi-turn injection. In order to continuously extraction the proton with small beam loss, an achromatic structure is proposed and a slow extraction method with RF knock-out is adopted and optimized.

  12. Injection into booster synchrotron with a 50 MeV linac

    International Nuclear Information System (INIS)

    A 50 MeV electron linear accelerator (linac) will be used as an injector for the booster synchrotron in place of 20 MeV microtron. In order to accommodate electrons with energy spread of ± 0.25% / ± 0.5% from the linac, it is required to modify the injection scheme. In this paper various options are explored for efficient injection. (author)

  13. 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.)

  14. (n,Xn) measurements at 100 MeV. Recent developments and first results

    Energy Technology Data Exchange (ETDEWEB)

    Blideanu, V. [Lab. de Physique Corpusculaire, Caen (France); Blomgren, J.; Eudes, P.; Fontbonne, J.M.; Foucher, Y.; Guertin, A.; Hadad, F.; Hay, L.; Hildebrand, A.; Iltis, G.; Le Brun, C.; Lecolley, F.R.; Lecolley, J.F.; Lefort, T.; Louvel, M.; Mermod, P.; Marie, N.; Olsson, N.; Pomp, S.; Osterlund, M.; Prokoviev, A.V.

    2003-07-01

    In the framework of the HINDAS project, we have studied the feasibility of (n,Xn) measurements at intermediate energy (20-200 MeV). To achieve this goal, we have developed a new set-up and performed several experiments using the monoenergetic neutron beam facility at the Svedberg laboratory (Sweden). The performance of this set-up is illustrated by first results obtained in 100 MeV neutron-induced reactions on a lead target. (orig.)

  15. 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.

  16. 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)

  17. Measurement of 1.7 to 74 MeV polarised gamma rays with the HARPO TPC

    CERN Document Server

    Geerebaert, Y; Amano, S; Attié, D; Bernard, D; Bruel, P; Calvet, D; Colas, P; Daté, S; Delbart, A; Frotin, M; Giebels, B; Götz, D; Hashimoto, S; Horan, D; Kotaka, T; Louzir, M; Minamiyama, Y; Miyamoto, S; Ohkuma, H; Poilleux, P; Semeniouk, I; Sizun, P; Takemoto, A; Yamaguchi, M; Wang, S

    2016-01-01

    Current {\\gamma}-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 program to characterise the operation of a TPC (Time Projection Chamber) as a high angular-resolution and sensitivity telescope and polarimeter for {\\gamma} 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 {\\gamma}-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 electronic...

  18. Fast neutron response of {sup 6}Li-depleted CLYC detectors up to 20 MeV

    Energy Technology Data Exchange (ETDEWEB)

    D' Olympia, N., E-mail: nathan_dolympia@student.uml.edu; Chowdhury, P.; Jackson, E.G.; Lister, C.J.

    2014-11-01

    The response of {sup 6}Li-depleted Cs{sub 2}LiYCl{sub 6} (CLYC) to high-energy neutrons has been investigated using a pair of 1 in.×1 in. crystals. These are the first two detectors of their kind, which will comprise a 16-element array for studies in fast neutron spectroscopy. Their thermal neutron response has been compared with standard CLYC crystals with a {sup 6}Li enrichment of 95%, demonstrating excellent suppression of the overwhelming thermal neutron background. The response to mono-energetic neutrons over a range of 0.5 to 20 MeV was tested. From this, the response function, energy resolution, and pulse-shape discrimination up to 20 MeV were characterized. Detailed Monte Carlo investigations with MCNPX have been used to show that the dominant reaction mechanisms contributing to the observed response are {sup 35}Cl(n,p) and {sup 35}Cl(n,α). Preliminary investigations have also demonstrated the possibility for separating events from these two reactions.

  19. 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...

  20. Study of the He3 breakup reaction and the triton production spectra at 283 MeV

    International Nuclear Information System (INIS)

    The breakup of He3 ions at 94MeV/nucleon was studied in inclusive experiments on nuclei ranging from C12 to Pb208, and in coincidence experiments (γd) and (γt) on an A127 target. The inclusive spectra of protons and deuterons show an important contribution of the He3 breakup reaction to the reaction cross section (80%). Analysis of the dependence as a function of A confirms a peripheral mechanism. The coincidence experiment gives a proportion of inelastic breakup in the inclusive cross section of 40 %. Examination of triton spectra reveals that at 94 MeV the dominant reaction is not breakup transfer as at lower energies, but charge exchange. The spectra peak at energies of 20MeV, compatible with the excitation of a mixture of L=1 and L=2 states. The variation of the cross section following an A1/3 law indicates a peripheral mechanism for the (He3,t) reaction too. The (γ-t) coincidence reaction showing residual nucleus production near the target nucleus reinforces this result

  1. 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.

  2. Improve the physical and chemical properties of biocompatible polymer material by MeV He ion beam

    International Nuclear Information System (INIS)

    There is a high interest in improving the hydrophilicity of polymer surfaces due to their wide use for technological purposes. In this study Ultra High Molecular Weight Polyethylene (UHMWPE) as a biocompatible material was bombarded with 1 MeV He ions to the fluences ranging from 1×1013 to 5×1014 cm−2. The pristine and ion beam modified samples were investigated by photoluminescence (PL), ultraviolet–visible (UV–vis) spectroscopy and Fourier Transform Infrared Spectroscopy (FTIR). The changes of wettability and surface free energy were determined by the contact angle measurements. The obtained results showed that the ion bombardment induced decrease in integrated luminescence intensity and decrease in the transmittance with increase of ion fluence as well. This is might be attributed to degradation of polymer surface and/or creation of new electronic levels in the forbidden gap. The FTIR spectral studies indicate that the ion beam induces chemical modifications within the bombarded UHMWPE. Formation of carbonyl groups (C=O) on the polymer surface was studied. Direct relationship of the wettability and surface free energy of the bombarded polymer with the ion fluences was observed. - Highlights: ► Effect of 1 MeV He-ion bombardment on the surface properties of UHMWPE was studied. ► Change in the surface layer composition of UHMWPE due ion beam has been investigated. ► Ion beam bombardment improves the surface free energy of UHMWPE.

  3. 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)

  4. An 800-MeV proton radiography facility for dynamic experiments

    Energy Technology Data Exchange (ETDEWEB)

    King, N.S.P.; Adams, K.; Alrick, K.R.; Crow, M.L.; Cushing, S.B.; Eddleman, J.C.; Fife, T.T.; Gallegos, R.A.; Gray, N.T.; Hogan, G.E.; Holmes, V.H.; 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.; Pazuchanics, P.D.; Pillai, C.; Riedel, C.M.; Sarracino, J.S.; Shelley, F.E. Jr.; Stacy, H.L.; Takala, B.E.; Tucker, H.E.; Yates, G.J.; Ziock, H.-J.; Zumbro, J.D. [Los Alamos National Laboratory, Los Alamos, NM 87545 (United States); Ables, E. [Livermore National Laboratory, Livermore, CA 94550 (United States); Balzar, Stephen [Bechtel Nevada, Los Alamos, NM 87545 (United States); Barnes, P.D. Jr. [Livermore National Laboratory, Livermore, CA 94550 (United States); Flores, Paul [Bechtel Nevada, Los Alamos, NM 87545 (United States); Fujino, D. [Livermore National Laboratory, Livermore, CA 94550 (United States); Hartouni, E.P. [Livermore National Laboratory, Livermore, CA 94550 (United States); Jaramillo, S.A. [Los Alamos National Laboratory, Los Alamos, NM 87545 (United States); Parker, E.L. [Livermore National Laboratory, Livermore, CA 94550 (United States); Park, H.S. [Livermore National Laboratory, Livermore, CA 94550 (United States); Thompson, Richard [Bechtel Nevada, Los Alamos, NM 87545 (United States)

    1999-11-03

    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 array in the image plane but also have a dynamic range which permits recording radiographs with better than 5% statistics for observation of detailed density variations in the object. A number of tests have been carried out to characterize the quality of the proton radiography system for absolute mass determination, resolution, and dynamic range. Initial dynamic experiments characterized the temporal and spatial behavior of shock propagation in a high explosive sample with up to six images per experiment. Based on experience with the prototype system, a number of upgrades are being implemented including the anticipated capability for enhanced mass discrimination through differential multiple coulomb scattering radiographs and more images with improved imaging techniques.

  5. Isotopic composition of cosmic-ray helium from 123 279 MeV per nucleon: a new measurement and analysis

    International Nuclear Information System (INIS)

    Differential energy spectra of primary cosmic-ray helium and hydrogen nuclei in the energy range 123--279 MeV per nucleon were measured on a balloon flight from Thompson, Manitoba, in 1973 August during a time of relatively quiet interplanetary conditions. This represents the first reported 3He--4He measurement in this energy range since 1966. The detector was a Geiger tube hodoscope operated in conjunction with a double dE/dx versus E scintillation counter. The observed average 3He/(3He+4He) ratio in the modulated spectra was found to be 0.105 +- 0.012, which is larger than the average value of approx.0.05 measured by satellites below 100 MeV per nucleon during the same time period, indicating that the so-called anomalous 4He component does not contribute significantly to the spectrum in the energy range covered by this experiment. The interstellar 3He/(3He+4He) ratio GAMMA/sub int/, when corrected for solar modulation by using up-to-date models, lies between 0.11 and 0.29, on the basis of very broad assumptions, with a most likely value of GAMMA/sub int/=0.16 +- 0.03, implying the traversal of a mean thickness of interstellar gas of 4--6 g cm-2 between cosmic-ray sources and the local interstellar space. The small deuteron flux coupled with abundant production of secondaries in the overlying atmosphere make it possible to quote only upper limits for the deuteron spectrum

  6. 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.

  7. Neutron induced fission cross section ratios for 232Th, /sup 235,238/U, 237Np, and 239Pu from 1 to 400 MeV

    International Nuclear Information System (INIS)

    Time-of-flight measurements of neutron induced fission cross section ratios for 232Th, /sup 235,238/U, 237Np, and 239Pu, were performed using the WNR high intensity spallation neutron source located at Los Alamos National Laboratory. A multiple-plate gas ionization chamber located at a 20-m flight path was used to simultaneously measure the fission rate for all samples over the energy range from 1 to 400 MeV. Because the measurements were made with nearly identical neutron fluxes, we were able to cancel many systematic uncertainties present in previous measurements. This allows us to resolve discrepancies among different data sets. In addition, these are the first neutron-induced fission cross section values for most of the nuclei at energies above 30 MeV. 8 refs., 3 figs

  8. Determination of sensitivity of the SNM-14 slow neutron counter with a combined moderator at the 14.2 MeV neutron energy

    International Nuclear Information System (INIS)

    The sensitivity of the SNM-14 slow neutron counter a combined moderator at the 14.2 MeV neutron energy has been experimentally determined. The 14.2 MeV neutrons were produced by means of a neutron laser generator using the T(d, n)4He reaction. The mean value of senstivity of the SNM-14 counter difined by the measurement results at different distances from the neutron source was equal to (0.37+-0.03) count. cm2. neutron-1. The obtained sensitivity value may be used in determining the energy dependence of the sensitivity in essential neutron energy range. It permits to evaluate the error of the device used as a dosimeter in radiation fields of nuclear installations

  9. Global optical model potentials for symmetrical lithium systems: 6Li+6Li, 7Li+7Li at Elab = 5-40 MeV

    International Nuclear Information System (INIS)

    Angular distributions of 6Li+6Li elastic scattering were measured for Elab=5-40 MeV. An optical model analysis of these data together with older data of 7Li+7Li elastic scattering taken at Elab = 8-17 MeV was performed with the aim to search for a ''global'' OM potential which describes elastic scattering in both Li-Li systems in a broad energy range. Both surface and volume absorbing potentials can be found which fulfill this requirement if a linear energy dependence is assumed of the depths of the real as well as the imaginary potential. These depths, if fitted to individual angular distributions, are found to vary in a correlated manner with the beam energy. This is taken as indication of strong coupling between elastic, inelastic, and reaction channels. This is corroborated by the existence of resonances in reaction channels at these energies where the potential depths are most pronouncedly changing. (orig.)

  10. Space distributions and decay probability for excited state of 7Li*(7,45 MeV) in reaction 7Li(alpha, alpha6Li)n

    International Nuclear Information System (INIS)

    Differential cross-sections of excitation and decay of 7Li*(7,45 MeV) resonance into 6Li + n channel in three particle reaction 7Li(alpha, alpha6Li)n at alpha-particle energy of 27,2 MeV have been determined in kinematically complete and incomplete experiments. Usage of position sensitive detector made it possible to obtain the data on space distributions of decay events for full range of possible angles and to determine the total probability of this process, which value essentially differs from the data for binary reactions. This result is agreed with previously obtained [1] and confirms the theoretical calculations [2] of decay branching ratio for short lived near-threshold resonances in three particle reactions

  11. Measurement of the response function and the detection efficiency of an organic liquid scintillator for neutrons between 1 and 30 MeV

    Institute of Scientific and Technical Information of China (English)

    HUANG Han-Xiong; RUAN Xi-Chao; CHEN Guo-Chang; ZHOU Zu-Ying; LI Xia; BAO Jie; NIE Yang-Bo; ZHONG Qi-Ping

    2009-01-01

    The light output function of a φ50.8 mm×50.8 mm BC501A scintillation detector was measured in the neutron energy region of 1 to 30 MeV by fitting the pulse height (PH) spectra for neutrons with the simulations from the NRESP code at the edge range. Using the new light output function, the neutron detection efficiency was determined with two Monte-Carlo codes, NEFF and SCINFUL. The calculated efficiency was corrected by comparing the simulated PH spectra with the measured ones. The determined efficiency was verified at the near threshold region and normalized with a Proton-Recoil-Telescope (PRT) at the 8-14 MeV energy region.

  12. Measurement of the $\\mathrm e^+\\mathrm e^-\\rightarrow\\mathrm\\pi^+\\mathrm\\pi^-$ Cross Section between 600 and 900 MeV Using Initial State Radiation

    CERN Document Server

    Ablikim, M; Ai, X C; Albayrak, O; Albrecht, M; Ambrose, D J; Amoroso, A; An, F F; An, Q; Bai, J Z; Ferroli, R Baldini; Ban, Y; Bennett, D W; Bennett, J V; Bertani, M; Bettoni, D; Bian, J M; Bianchi, F; Boger, E; Boyko, I; Briere, R A; Cai, H; Cai, X; Cakir, O; Calcaterra, A; Cao, G F; Cetin, S A; Chang, J F; Chelkov, G; Chen, G; Chen, H S; Chen, H Y; Chen, J C; Chen, M L; Chen, S J; Chen, X; Chen, X R; Chen, Y B; Cheng, H P; Chu, X K; Cibinetto, G; Dai, H L; Dai, J P; Dbeyssi, A; Dedovich, D; Deng, Z Y; Denig, A; Denysenko, I; Destefanis, M; De Mori, F; Ding, Y; Dong, C; Dong, J; Dong, L Y; Dong, M Y; Du, S X; Duan, P F; Eren, E E; Fan, J Z; Fang, J; Fang, S S; Fang, X; Fang, Y; Fava, L; Feldbauer, F; Felici, G; Feng, C Q; Fioravanti, E; Fritsch, M; Fu, C D; Gao, Q; Gao, X Y; Gao, Y; Gao, Z; Garzia, I; Goetzen, K; Gong, W X; Gradl, W; Greco, M; Gu, M H; Gu, Y T; Guan, Y H; Guo, A Q; Guo, L B; Guo, Y; Guo, Y P; Haddadi, Z; Hafner, A; Han, S; Hao, X Q; Harris, F A; He, K L; He, X Q; Held, T; Heng, Y K; Hou, Z L; Hu, C; Hu, H M; Hu, J F; Hu, T; Hu, Y; Huang, G M; Huang, G S; Huang, J S; Huang, X T; Huang, Y; Hussain, T; Ji, Q; Ji, Q P; Ji, X B; Ji, X L; Jiang, L W; Jiang, X S; Jiang, X Y; Jiao, J B; Jiao, Z; Jin, D P; Jin, S; Johansson, T; Julin, A; Kalantar-Nayestanaki, N; Kang, X L; Kang, X S; Kavatsyuk, M; Ke, B C; Kiese, P; Kliemt, R; Kloss, B; Kolcu, O B; Kopf, B; Kornicer, M; Kühn, W; Kupsc, A; Lange, J S; Lara, M; Larin, P; Leng, C; Li, C; Li, Cheng; Li, D M; Li, F; Li, F Y; Li, G; Li, H B; Li, J C; Li, Jin; Li, K; Li, Lei; Li, P R; Li, T; Li, W D; Li, W G; Li, X L; Li, X M; Li, X N; Li, X Q; Li, Z B; Liang, H; Liang, Y F; Liang, Y T; Liao, G R; Lin, D X; Liu, B J; Liu, C X; Liu, F H; Liu, Fang; Liu, Feng; Liu, H B; Liu, H H; Liu, H M; Liu, J; Liu, J B; Liu, J P; Liu, J Y; Liu, K; Liu, K Y; Liu, L D; Liu, P L; Liu, Q; Liu, S B; Liu, X; Liu, Y B; Liu, Z A; Liu, Zhiqing; Loehner, H; Lou, X C; Lu, H J; Lu, J G; Lu, Y; Lu, Y P; Luo, C L; Luo, M X; Luo, T; Luo, X L; Lyu, X R; Ma, F C; Ma, H L; Ma, L L; Ma, Q M; Ma, T; Ma, X N; Ma, X Y; Maas, F E; Maggiora, M; Mao, Y J; Mao, Z P; Marcello, S; Messchendorp, J G; Min, J; Mitchell, R E; Mo, X H; Mo, Y J; Morales, C Morales; Moriya, K; Muchnoi, N Yu; Muramatsu, H; Nefedov, Y; Nerling, F; Nikolaev, I B; Ning, Z; Nisar, S; Niu, S L; Niu, X Y; Olsen, S L; Ouyang, Q; Pacetti, S; Patteri, P; Pelizaeus, M; Peng, H P; Peters, K; Pettersson, J; Ping, J L; Ping, R G; Poling, R; Prasad, V; Qi, M; Qian, S; Qiao, C F; Qin, L Q; Qin, N; Qin, X S; Qin, Z H; Qiu, J F; Rashid, K H; Redmer, C F; Ripka, M; Rong, G; Rosner, Ch; Ruan, X D; Santoro, V; Sarantsev, A; Savrié, M; Schoenning, K; Schumann, S; Shan, W; Shao, M; Shen, C P; Shen, P X; Shen, X Y; Sheng, H Y; Song, W M; Shepherd, M R; Song, X Y; Sosio, S; Spataro, S; Sun, G X; Sun, J F; Sun, S S; Sun, Y J; Sun, Y Z; Sun, Z J; Sun, Z T; Tang, C J; Tang, X; Tapan, I; Thorndike, E H; Tiemens, M; Ullrich, M; Uman, I; Varner, G S; Wang, B; Wang, D; Wang, D Y; Wang, K; Wang, L L; Wang, L S; Wang, M; Wang, P; Wang, P L; Wang, S G; Wang, W; Wang, X F; Wang, Y D; Wang, Y F; Wang, Y Q; Wang, Z; Wang, Z G; Wang, Z H; Wang, Z Y; Weber, T; Wei, D H; Wei, J B; Weidenkaff, P; Wen, S P; Wiedner, U; Wolke, M; Wu, L H; Wu, Z; Xia, L G; Xia, Y; Xiao, D; Xiao, H; Xiao, Z J; Xie, Y G; Xiu, Q L; Xu, G F; Xu, L; Xu, Q J; Xu, X P; Yan, L; Yan, W B; Yan, W C; Yan, Y H; Yang, H J; Yang, H X; Yang, L; Yang, Y; Yang, Y X; Ye, M; Ye, M H; Yin, J H; Yu, B X; Yu, C X; Yu, J S; Yuan, C Z; Yuan, W L; Yuan, Y; Yuncu, A; Zafar, A A; Zallo, A; Zeng, Y; Zhang, B X; Zhang, B Y; Zhang, C; Zhang, C C; Zhang, D H; Zhang, H H; Zhang, H Y; Zhang, J J; Zhang, J L; Zhang, J Q; Zhang, J W; Zhang, J Y; Zhang, J Z; Zhang, K; Zhang, L; Zhang, X Y; Zhang, Y; Zhang, Y N; Zhang, Y H; Zhang, Y T; Zhang, Yu; Zhang, Z H; Zhang, Z P; Zhang, Z Y; Zhao, G; Zhao, J W; Zhao, J Y; Zhao, J Z; Zhao, Lei; Zhao, Ling; Zhao, M G; Zhao, Q; Zhao, Q W; Zhao, S J; Zhao, T C; Zhao, Y B; Zhao, Z G; Zhemchugov, A; Zheng, B; Zheng, J P; Zheng, W J; Zheng, Y H; Zhong, B; Zhou, L; Zhou, X; Zhou, X K; Zhou, X R; Zhou, X Y; Zhu, K; Zhu, K J; Zhu, S; Zhu, S H; Zhu, X L; Zhu, Y C; Zhu, Y S; Zhu, Z A; Zhuang, J; Zotti, L; Zou, B S; Zou, J H

    2015-01-01

    We extract the $e^+e^-\\rightarrow \\pi^+\\pi^-$ 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 is used. The cross section is measured with a systematic uncertainty of 0.9%. We extract the pion form factor $|F_\\pi|^2$ as well as the contribution of the measured cross section to the leading order hadronic vacuum polarization contribution to $(g-2)_\\mu$. We find this value to be $a_\\mu^{\\pi\\pi,\\rm LO}(600-900\\;\\rm MeV) = (372.5 \\pm 2.6_{\\rm stat} \\pm 3.4_{\\rm sys})\\cdot 10^{-10}$.

  13. Absolute calibration of the [sup 16]O([alpha],[alpha])[sup 16]O elastic scattering resonance at 7. 30-7. 65 MeV and applications to oxygen depth profiling

    Energy Technology Data Exchange (ETDEWEB)

    Almeida, F.J.D. (Accelerator Lab., McMaster Univ., Hamilton, ON (Canada)); Davies, J.A. (Accelerator Lab., McMaster Univ., Hamilton, ON (Canada)); Jackman, T.E. (Inst. for Microstructural Sciences, National Research Council, Ottawa, ON (Canada))

    1993-08-01

    The differential cross-section of the [sup 16]O([alpha],[alpha])[sup 16]O elastic scattering resonance at 7.30-7.65 MeV has been calibrated with an overall accuracy of 4% at 170 scattering angle (laboratory frame of reference) using anodized Ta[sub 2]O[sub 5] films of pre-calibrated thickness as standards. This extremely strong (about 170 times the Rutherford cross-section) and broad (about 300 keV wide) resonance varies slowly with energy in the range 7.34-7.64 MeV, has a maximum value of 837 mb/sr at 7.61 MeV, and falls off abruptly above 7.64 MeV and below 7.34 MeV. The angular dependence of the resonance was measured in the range 140-172 at incident energy 7.62 MeV and was found to increase monotonically toward 180 . This strong resonance allowed us to measure the oxygen content in the very heavy element target ThO[sub 2] pellets and in oxidized InP substrates with detection sensitivity in the atomic monolayer range. The large width of this resonance allowed oxygen depth profiling to several microns with depth resolution a few tens of nm. Measurements combined with RUMP computer simulations using TRIM stopping cross-sections and our measured values of the elastic resonance scattering cross-section have been used to depth profile SiO[sub 2] surface and buried layers in SIMOX structures. (orig.)

  14. 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.

  15. Sequential mechanism for the Li7 (He3, α)6 Li(d)α reaction at incident energy between 2.5 and 11.5 MeV

    International Nuclear Information System (INIS)

    A strictly sequential mechanism appears to appropriate for the Li7 (3He,α)6Li(d)α reaction in the energy range between 2.5 and 11.5 MeV. It can be described by a first direct emission mechanism and a second delayed emission

  16. Possibilities of capture of swift bombarding heavy Kr 86 ions with energy EKr=394 MeV and FKA from its into axial channeling regime under irradiation GaAs single crystal

    International Nuclear Information System (INIS)

    The results of radiation damage study at GaAs [100] after irradiation by swift heavy 84Kr7+ with energy EKr=394 MeV up to the fluence Φt=5·1012 ion/cm2. The distribution of damage along the projected ranges of ions in crystal was investigated using selective chemical etching of cross-sections. (authors)

  17. Theoretical model analysis of (d ,x n ) reactions on 9Be and 12C at incident energies up to 50 MeV

    Science.gov (United States)

    Nakayama, Shinsuke; Kouno, Hiroshi; Watanabe, Yukinobu; Iwamoto, Osamu; Ogata, Kazuyuki

    2016-07-01

    Background: In the design of deuteron accelerator neutron sources, accurate nuclear data of deuteron-induced reactions are indispensable over a wide range of incident energy. Reliable model calculations play an important role in completing the necessary nuclear data since currently available experimental data are insufficient. We have been developing a code system dedicated for the deuteron-induced reactions, called deuteron-induced reaction analysis code system (DEURACS). It was applied successfully to (d ,x p ) reactions at 56 and 100 MeV. Purpose: The purpose of the present work is to investigate the applicability of DEURACS to (d ,x n ) reactions on 9Be and 12C for incident energies below 50 MeV and to clarify neutron production mechanism. Methods: Double-differential thick target neutron yields (TTNYs) from deuteron bombardment on thick Be and C targets are analyzed. The TTNYs are derived using the double differential (d ,x n ) cross sections calculated by DEURACS and the stopping power of deuteron in the target. The calculated TTNYs are decomposed into individual components corresponding to elastic breakup, proton stripping, and statistical decay reactions. Results: The calculated TTNYs reproduced the experimental data quantitatively well in the incident energy range up to 50 MeV. From the analysis, it was found that the proton stripping reaction makes the most dominant contribution to neutron production. Conclusions: DEURACS is applicable to (d ,x n ) reactions on 9Be and 12C for incident energies below 50 MeV. Modeling of the stripping reaction is essential to predict neutron production yields accurately in the design of deuteron accelerator neutron sources.

  18. 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...

  19. Telemetry Ranging: Concepts

    Science.gov (United States)

    Hamkins, J.; Kinman, P.; Xie, H.; Vilnrotter, V.; Dolinar, S.

    2015-11-01

    Telemetry ranging is a proposed alternative to conventional two-way ranging for determining the two-way time delay between a Deep Space Station (DSS) and a spacecraft. The advantage of telemetry ranging is that the ranging signal on the uplink is not echoed to the downlink, so that telemetry alone modulates the downlink carrier. The timing information needed on the downlink, in order to determine the two-way time delay, is obtained from telemetry frames. This article describes the phase and timing estimates required for telemetry ranging, and how two-way range is calculated from these estimates. It explains why the telemetry ranging architecture does not require the spacecraft transponder to have a high-frequency or high-quality oscillator, and it describes how a telemetry ranging system can be infused in the Deep Space Network.

  20. Complete identification of states in 208Pb below Ex=6.2 MeV

    Science.gov (United States)

    Heusler, A.; Jolos, R. V.; Faestermann, T.; Hertenberger, R.; Wirth, H.-F.; von Brentano, P.

    2016-05-01

    The Q3D magnetic spectrograph at the Maier-Leibnitz-Laboratorium of the Ludwig-Maximilians-Universität München and the Technische Universität München (Garching, Germany), was used to study the 208Pb(p ,p' ) , 206,207,208Pb (d,p), and 208Pb(d ,d' ) reactions. One hundred fifty-one states at Ex<6.20 MeV in 208Pb are identified and spin and parity assigned. Four states are newly identified and new spins and/or parities are assigned to 25 states. Tentative spin assignments are done to five states at 5.90 MeV . Nearly 50 levels below Ex=6.20 MeV listed by the Nuclear Data Sheets as of 2007 are recognized to be nonexistent or doubly placed. The schematic shell model describing one-particle-one-hole configurations without residual interaction is extended by including two-particle-two-hole configurations. The number of configurations thus predicted at Ex<6.20 MeV nearly agrees with the number of states identified. Several states with dominant two-particle-two-hole configurations are identified. New isobaric analog resonances in 209Bi with two-particle-one-hole structure are discovered at Eres=17.6 MeV . The excitation energies of 70 states with unnatural parity at Ex<6.20 MeV are found to agree within about 200 keV with one-particle-one-hole configurations predicted by the extended schematic shell model. In contrast, the excitation energies of about 20 natural parity states are more than 0.5 MeV lower than predicted, demonstrating the residual interaction among the configurations to be much larger for natural parity than for unnatural parity.

  1. Gain ranging amplifier

    International Nuclear Information System (INIS)

    A gain ranging amplifier system is provided for use in the acquisition of data. Voltage offset compensation is utilized to correct errors in the gain ranging amplifier system caused by thermal drift and temperature dependent voltage offsets, both of which are associated with amplifiers in the gain ranging amplifier system

  2. Patient positioning for protontherapy using a proton range telescope

    International Nuclear Information System (INIS)

    A method is described for imaging integrated density along the beam path in phantoms that makes use of high energy proton beams. An application of the technique is in the positioning of patients in a proton therapy radiation facility. It makes use of a proton range telescope for density variation and X-Y detectors for planar positioning. The principle of the method was tested at a proton energy of 66 MeV. Good visual quality is seen in the tests. The measurements are compared with detailed Monte Carlo simulations, and good agreement is found. We apply the simulations to high energy proton beams (245 MeV) and show that the method should provide good visual quality and sensitivity for positioning at the higher energies necessary for whole body therapy. ((orig.))

  3. 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

  4. A 100 MW far-infrared free-electron laser driven by a 180 MeV RF-linac

    CERN Document Server

    Asakawa, M; Gotoda, K; Ohigashi, N; Tsunawaki, Y; Imasaki, K

    2002-01-01

    The development of a 100 MW far-infrared free-electron laser oscillator is reported. By using a 180 MeV electron beam, this system will provide the high power and the rapid scanning of the broad wavelength range, 10-100 mu m, to enhance the user programs. The intracavity power of several GWs will be used for Compton backscattering X- or gamma-ray generation. To store such an intense radiation, the dynamics of the FEL oscillator with a coupling parameter mu sub c<=1, which is defined as the ratio of the slippage distance and the electron bunch length, was investigated experimentally on the operating mid-infrared system.

  5. HRTEM study of track evolution in 120-MeV U irradiated Gd2Ti2O7

    Science.gov (United States)

    Jozwik-Biala, I.; Jagielski, J.; Thomé, L.; Arey, B.; Kovarik, L.; Sattonnay, G.; Debelle, A.; Monnet, I.

    2012-09-01

    High Resolution Scanning Transmission Electron Microscopy (HRTEM) experiments were performed on Gd2Ti2O7 pyrochlore irradiated with 120-MeV U ions. A judicious choice of irradiation energy, sample preparation (using Focused Ion Beam) and analytical technique (HRTEM) allowed us to visualize the complete evolution of tracks from the surface of samples down to depths exceeding the projected range of irradiating ions. Such features as variation of track diameters, changes in track directions and discontinuous segments of tracks were clearly documented at various depths. By using two different Scanning Transmission Electron Microscopy (STEM) imaging modes: High- and Low-Angle Annular Dark Field imaging (HAADF and LAADF), it was possible to observe the radial substructure of tracks composed of an amorphous core surrounded by a damaged and strained crystalline envelope.

  6. HRTEM study of track evolution in 120-MeV U irradiated Gd2Ti2O7

    Energy Technology Data Exchange (ETDEWEB)

    Jozwik Biala, Iwona; Jagielski, Jacek K.; Thome, Lionel; Arey, Bruce W.; Kovarik, Libor; Sattonay, G.; Debelle, A.; Monnet, I.

    2012-09-01

    High resolution Scanning Transmission Electron Microscopy (HRTEM) experiments were performed on Gd2Ti2O7 pyrochlores irradiated with 120-MeV U ions. A judicious choice of irradiation energy, sample preparation (using Focused Ion Beam) and analytical technique (HRTEM) allowed us to visualize the complete evolution of tracks from the surface of samples down to depths exceeding the projected range of irradiating ions. Such features as variation of track diameters, changes in track directions and discontinuous segments of tracks were clearly documented at various depths. By using two different STEM imaging modes: High- and Low-Angle Annular Dark Field imaging (HAADF and LAADF), it was possible to observe the layered structure of tracks composed of an amorphous core surrounded by a strained crystalline envelope.

  7. Velocity spectra and angular distributions of evaporation residues from sup 32 S + sup 12 C at 145 MeV

    Energy Technology Data Exchange (ETDEWEB)

    Arena, N.; Cavallaro, S.; Femino' , S.; Figuera, P.; Pirrone, S.; Porto, F.; Sambataro, S. (Dipartimento di Fisica, Universita di Catania, Universita di Messina, Istituto Nazionale di Fisica Nucleare, Sezione di Catania and Laboratorio Nazionale del Sud I-95129 Catania (Italy))

    1991-11-01

    Velocity spectra and angular and mass distributions for the evaporation residues of the {sup 32}S+{sup 12}C system at {ital E}{sup 32}S=145 MeV in the angular range 3{degree}{le}{var theta}{sub {ital L}}{le}12{degree} have been measured. In order to separate compound nucleus evaporation residues from other heavy reaction products, a kinematic analysis based on simple statistical assumptions relative to the velocity spectra was performed. The structures in the mass distribution are compared with the LILITA code predictions. The fusion excitation function of the existing results is compared with theoretical models. The total reaction cross section has been extracted by means of the modified sum of differences method.

  8. 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 ...

  9. Neutron field produced by 25 MeV deuteron on thick beryllium for radiobiological study; energy spectrum.

    Science.gov (United States)

    Takada, Masashi; Mihara, Erika; Sasaki, Michiya; Nakamura, Takashi; Honma, Toshihiko; Kono, Koji; Fujitaka, Kazunobu

    2004-01-01

    Biological data is necessary for estimation of protection from neutrons, but there is a lack of data on biological effects of neutrons for radiation protection. Radiological study on fast neutrons has been done at the National Institute of Radiological Sciences. An intense neutron source has been produced by 25 MeV deuterons on a thick beryllium target. The neutron energy spectrum, which is essential for neutron energy deposition calculation, was measured from thermal to maximum energy range by using an organic liquid scintillator and multi-sphere moderated 3He proportional counters. The spectrum of the gamma rays accompanying the neutron beam was measured simultaneously with the neutron spectrum using the organic liquid scintillator. The transmission by the shield of the spurious neutrons originating from the target was measured to be less than 1% by using the organic liquid scintillator placed behind the collimator. The measured neutron energy spectrum is useful in dose calculations for radiobiology studies.

  10. Breakup of 96 MeV α-particles in the 58,64Ni niclei fields

    International Nuclear Information System (INIS)

    The aim of the paper is to investigate the process of α-particle breakup into two deuterons and to estimate the applicability of data on breakup for extraction of diffusivity parameter (a) in the framework of the diffraction approach. Measurements of absolute values of differential cross sections (DCS) of 96 MeV α-particle breakup on 58,64Ni are carried out in the limited angular range: Θ1=22.5 deg, Θ2=50, 55, 60, -50, -60 deg. Wide maxima typical for the process of incident α-particle breakup are observed in deuteron energy spectra. Measured DCS for α-particle breakup show distinct difference for 58Ni and 64Ni. The calculations describe satisfactorily this difference in the framework of the diffraction approach, if it is supposed that the diffusivity parameter for 58Ni nucleus has the value a=0.65 fm, and for 64Ni - a=0.85 fm

  11. 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.

  12. 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.

  13. 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. PMID:27227905

  14. Telemetry Ranging: Signal Processing

    Science.gov (United States)

    Hamkins, J.; Kinman, P.; Xie, H.; Vilnrotter, V.; Dolinar, S.

    2016-02-01

    This article describes the details of the signal processing used in a telemetry ranging system in which timing information is extracted from the downlink telemetry signal in order to compute spacecraft range. A previous article describes telemetry ranging concepts and architecture, which are a slight variation of a scheme published earlier. As in that earlier work, the telemetry ranging concept eliminates the need for a dedicated downlink ranging signal to communicate the necessary timing information. The present article describes the operation and performance of the major receiver functions on the spacecraft and the ground --- many of which are standard tracking loops already in use in JPL's flight and ground radios --- and how they can be used to provide the relevant information for making a range measurement. It also describes the implementation of these functions in software, and performance of an end-to-end software simulation of the telemetry ranging system.

  15. Cross sections for proton induced high energy γ -ray emission (PIGE) in reaction 19 F(p, αγ)16 O at incident proton energies between 1.5 and 4 MeV

    Science.gov (United States)

    Cabanelas, P.; Cruz, J.; Fonseca, M.; Henriques, A.; Lourenço, F.; Luís, H.; Machado, J.; Pires Ribeiro, J.; Sánchez-Benítez, A. M.; Teubig, P.; Velho, P.; Zarza-Moreno, M.; Galaviz, D.; Jesus, A. P.

    2016-08-01

    We have studied the high energy gamma-rays produced in the reaction 19 F(p, αγ)16 O for incident proton energies from 1.5 to 4.0 MeV over NaF/Ag and CaF2/Ag thin targets in two different sets of data. Gamma-rays were detected with a High Purity Ge detector with an angle of 130° with respect to the beam axis. The cross-sections for the high energy gamma-rays of 6.129, 6.915 and 7.115 MeV have been measured for the whole group between 5 and 7.2 MeV with accuracy better than 10%. A new energy range was covered and more points are included in the cross-sections data base expanding the existing set of data. Results are in agreement with previous measurements in similar conditions.

  16. 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.

  17. Telemetry-Based Ranging

    Science.gov (United States)

    Hamkins, Jon; Vilnrotter, Victor A.; Andrews, Kenneth S.; Shambayati, Shervin

    2011-01-01

    A telemetry-based ranging scheme was developed in which the downlink ranging signal is eliminated, and the range is computed directly from the downlink telemetry signal. This is the first Deep Space Network (DSN) ranging technology that does not require the spacecraft to transmit a separate ranging signal. By contrast, the evolutionary ranging techniques used over the years by NASA missions, including sequential ranging (transmission of a sequence of sinusoids) and PN-ranging (transmission of a pseudo-noise sequence) whether regenerative (spacecraft acquires, then regenerates and retransmits a noise-free ranging signal) or transparent (spacecraft feeds the noisy demodulated uplink ranging signal into the downlink phase modulator) relied on spacecraft power and bandwidth to transmit an explicit ranging signal. The state of the art in ranging is described in an emerging CCSDS (Consultative Committee for Space Data Systems) standard, in which a pseudo-noise (PN) sequence is transmitted from the ground to the spacecraft, acquired onboard, and the PN sequence is coherently retransmitted back to the ground, where a delay measurement is made between the uplink and downlink signals. In this work, the telemetry signal is aligned with the uplink PN code epoch. The ground station computes the delay between the uplink signal transmission and the received downlink telemetry. Such a computation is feasible because symbol synchronizability is already an integral part of the telemetry design. Under existing technology, the telemetry signal cannot be used for ranging because its arrival-time information is not coherent with any Earth reference signal. By introducing this coherence, and performing joint telemetry detection and arrival-time estimation on the ground, a high-rate telemetry signal can provide all the precision necessary for spacecraft ranging.

  18. 8 MeV electron irradiation studies on electrical characteristics of Cu(In,Ga)Se{sub 2} solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Rao, Asha [Department of Physics, Mangalore Institute of Technology and Engineering, Moodabidri, Mangalore 574 227 (India); Krishnan, Sheeja; Sanjeev, Ganesh [Microtron Centre, Department of Physics, Mangalore University, Mangalagangothri 574 199 (India); Siddappa, K. [JSS Foundation for Science and Society, Bangalore 560 085 (India); Ullal, Harin S.; Wu, Xuanzhi [National Center for Photovoltaics, National Renewable Energy Laboratory, 1617, Cole Boulevard, Golden, CO 80401 (United States)

    2009-09-15

    Cu(In,Ga)Se{sub 2} (CIGS) solar cells are gaining considerable interest due to their high optical absorption coefficient and adjustable band gap, which enables them to achieve high conversion efficiency and also present many promising applications in space power systems. In this paper we report the results of the effect of temperature and 8 MeV electron irradiation on the electrical characteristics of ZnO/CdS/Cu(In,Ga)Se{sub 2}/Mo polycrystalline thin-film solar cells under forward and reverse bias studied in the temperature range 270-315 K. The solar cells were subjected to 8 MeV electron irradiation from the Microtron accelerator and were exposed to graded doses of electrons up to 75 kGy. I-V characteristics of the cells under dark and AM 1.5 illumination condition were studied before and after the irradiation. Capacitance measurements were also carried out at various frequencies before and after irradiation. In the measured temperature range, the dark current contribution is due to the generation-recombination of the minority carriers in the depletion region. The ideality factor is found to decrease with increase in temperature. It seems that electron irradiation has not altered the dark current conduction mechanism significantly. The effect of electron irradiation on the solar cell parameters such as fill factor (FF), conversion efficiency ({eta}), saturation current (I{sub o}), short circuit current (I{sub sc}), open circuit voltage (V{sub oc}), and ideality factor (n) was studied. They were found to be stable up to 75 kGy of electron dose as only small changes were observed in the solar cell parameters. (author)

  19. Mouse skin reactions to 40 MeV helium ion irradiation

    International Nuclear Information System (INIS)

    The change of mouse skin was recorded periodically. Mice are periodically sacrificed to obtain irradiated skin specimens. The specimens are made into microscopic study preparations. 4He ion radiation dose applied to the skin ranges from 2,000 rads to 12,000 rads. 40MeV 4He ion beam is fairly stable. The study was repeated four times in total. When the beam position is in the center of scattering foil, Cobalt-60 gamma ray calibrateb one rad corresponded to 20-23 scattering 4He ion count detected by a solid state detector placed in the direction of 40 degree to the axis of down stream beam. One rad also corresponded to 0.52-0.55 nano-Ampere Farady cnp current placed in the center axis 80 centi-meter apart from the target foil. Monitoring with Farady cup current is more consistent, in which beam deviation from the center can not be detected. Hence the dose was monitored with the current with scattering helium count recorded. Depth dose was measured with TLD and 50% depth dose of plateau is approximately 0.08 g/cm. The skin was irradiated from 2,000 rads to 12,000 rads. In one week epilation starts. In two week complete epilation in all groups and in high dose groups (above 4,000 rads) at the same time erosions occur. In four weeks erosions heal. Higher dose group takes a little longer. In five weeks all erosins heal any way. Even the skin irradiated with 12,000 rads heals. Skin hypertrophy follows. The higher dose induces the more hypertrophy. Cell number in a hair follicle decreases with increased dose. Hair follicle itself decreases its number. (J.P.N.)

  20. 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.

  1. Irradiation damage induced on polyethylene terephtalate by 1.6 MeV deuteron ions

    Energy Technology Data Exchange (ETDEWEB)

    Abdesselam, M. [USTHB, Faculte de Physique, B.P. 32, El Alia, 16111 BEZ Algiers (Algeria); Djebara, M. [USTHB, Faculte de Physique, B.P. 32, El Alia, 16111 BEZ Algiers (Algeria)], E-mail: matjbara@yahoo.com; Chami, A.C. [USTHB, Faculte de Physique, B.P. 32, El Alia, 16111 BEZ Algiers (Algeria); Siad, M. [DPN, CNRA, 02 Bd Frantz Fanon, B.P. 399, Alger-gare (Algeria)

    2008-09-15

    The irradiation damage caused on polyethylene terephtalate (Mylar, PET) samples by 1.6 MeV deuteron ions has been measured using simultaneously the nuclear reaction analysis (NRA) and the transmission energy loss (TEL) techniques. The irradiation was carried out at normal incidence relative to the target surface with the irradiation beam being used as the analysis beam. The evolution of the overall damage during irradiation was evaluated by measuring the variation of the energy loss of the deuteron beam passing through the target. For this purpose, a solid state Si detector placed at a forward angle of 30 deg. relative to the incident beam direction was used. The NRA spectra recorded by a second Si detector located backward at 150 deg. allowed the evaluation of the carbon and the oxygen depletion. The beam spot size was circular in shape and 1 mm in diameter and the beam current was set at 5 nA. The ion fluence was increased up to the value of 2.5 x 10{sup 16} deuterons/cm{sup 2}. It was observed that the target energy loss decreased steadily as the fluence increased and levelled off at high fluence. The {sup 16}O(d,p{sub 0}){sup 17}O, {sup 16}O(d,p{sub 1}){sup 17}O{sup *} and {sup 12}C(d,p{sub 0}){sup 13}C reactions were used for monitoring the evolution of the oxygen and carbon content as a function of the deuteron fluence. A monotonic decrease of the oxygen content with the increase of ion fluence was observed. At the highest fluence the oxygen depletion reached a value of about 75%. For carbon, a weak depletion was observed at fluence ranging from 2.5 x 10{sup 15} d/cm{sup 2} to 1.0 x 10{sup 16} d/cm{sup 2} followed by a levelling-off with a total loss around 20%.

  2. Irradiation damage induced on polyethylene terephtalate by 1.6 MeV deuteron ions

    Science.gov (United States)

    Abdesselam, M.; Djebara, M.; Chami, A. C.; Siad, M.

    2008-09-01

    The irradiation damage caused on polyethylene terephtalate (Mylar, PET) samples by 1.6 MeV deuteron ions has been measured using simultaneously the nuclear reaction analysis (NRA) and the transmission energy loss (TEL) techniques. The irradiation was carried out at normal incidence relative to the target surface with the irradiation beam being used as the analysis beam. The evolution of the overall damage during irradiation was evaluated by measuring the variation of the energy loss of the deuteron beam passing through the target. For this purpose, a solid state Si detector placed at a forward angle of 30° relative to the incident beam direction was used. The NRA spectra recorded by a second Si detector located backward at 150° allowed the evaluation of the carbon and the oxygen depletion. The beam spot size was circular in shape and 1 mm in diameter and the beam current was set at 5 nA. The ion fluence was increased up to the value of 2.5 × 1016 deuterons/cm2. It was observed that the target energy loss decreased steadily as the fluence increased and levelled off at high fluence. The 16O(d,p0)17O, 16O(d,p1)17O∗ and 12C(d,p0)13C reactions were used for monitoring the evolution of the oxygen and carbon content as a function of the deuteron fluence. A monotonic decrease of the oxygen content with the increase of ion fluence was observed. At the highest fluence the oxygen depletion reached a value of about 75%. For carbon, a weak depletion was observed at fluence ranging from 2.5 × 1015 d/cm2 to 1.0 × 1016 d/cm2 followed by a levelling-off with a total loss around 20%.

  3. Prospect for Future MeV Gamma-ray Active Galactic Nuclei Population Studies

    CERN Document Server

    Inoue, Yoshiyuki; Odaka, Hirokazu; Takada, Atsushi; Ichinohe, Yuto; Saito, Shinya; Takeda, Shin'ichiro; Takahashi, Tadayuki

    2015-01-01

    While the X-ray, GeV gamma-ray, and TeV gamma-ray skies have been extensively studied, the MeV gamma-ray sky is not well investigated after the Imaging Compton Telescope (COMPTEL) scanned the sky about two decades ago. In this paper, we investigate prospects for active galactic nuclei population studies with future MeV gamma-ray missions using recent spectral models and luminosity functions of Seyfert and flat spectrum radio quasars (FSRQs). Both of them are plausible candidates as the origins of the cosmic MeV gamma-ray background. If the cosmic MeV gamma-ray background radiation is dominated by non-thermal emission from Seyferts, the sensitivity of 10^-12 erg cm^-2 s^-1 is required to detect several hundred Seyferts in the entire sky. If FSRQs make up the cosmic MeV gamma-ray background, the sensitivity of ~4 x 10^-12 erg cm^-2 s^-1 is required to detect several hundred FSRQs following the recent FSRQ X-ray luminosity function. However, based on the latest FSRQ gamma-ray luminosity function, with which FSRQ...

  4. The 31P(3He,d)32S reactions at 25MeV

    International Nuclear Information System (INIS)

    The 31P(3He,d)32S reaction was investigated at 25 MeV incident energy. One hundred and eleven levels up to an excitation energy of 12.5 MeV were observed using a split-pole magnetic spectrograph. The experimental angular distributions were analyzed with the distorted-wave Born approximation. The optical model parameters used in the DWBA calculations were obtained from a fit to elastic 3He scattering data taken on 31P at 25 MeV. Gamov functions were used as form factors for the transfered proton in the case of unbound states. Values of the transfered orbital angular momenta l and spectroscopic strengths were obtained for sixty levels, with many odd-parity levels being observed above 9 MeV excitation. Spin and parity assignments were made upon the basis of the l-values obtained from the shapes of the angular distributions and upon comparison with the results of other reactions. Isospin assignments were made by comparison with 32P levels. Except for the lsub(P)=1, T=0 transfers, most of the observed spectroscopic strength is concentrated into a few levels. The existence of a T-mixed doublet of levels, Jsup(π)=1-, is suggested in the 11 MeV region of excitation. The excitation energies and spectroscopic strengths are compared with results of a recent shell-model calculation

  5. Modification of semiconductor or metal nanoparticle lattices in amorphous alumina by MeV heavy ions

    Science.gov (United States)

    Bogdanović Radović, I.; Buljan, M.; Karlušić, M.; Jerčinović, M.; Dražič, G.; Bernstorff, S.; Boettger, R.

    2016-09-01

    In the present work we investigate effects of MeV heavy ions (from 0.4 MeV Xe to 15 MeV Si) on regularly ordered nanoparticle (NP) lattices embedded in amorphous alumina matrix. These nanostructures were produced by self-assembling growth using magnetron-sputtering deposition. From grazing incidence small-angle x-ray scattering measurements we have found that the used MeV heavy ions do not change the NP sizes, shapes or distances among them. However, ions cause a tilt of the entire NP lattice in the direction parallel to the surface. The tilt angle depends on the incident ion energy, type and the applied fluence and a nearly linear increase of the tilt angle with the ion fluence and irradiation angle was found. This way, MeV heavy ion irradiation can be used to design custom-made NP lattices. In addition, grazing incidence small-angle x-ray scattering can be effectively used as a method for the determination of material redistribution/shift caused by the ion hammering effect. For the first time, the deformation yield in amorphous alumina was determined for irradiation performed at the room temperature.

  6. 7.5 MeV High Average Power Linear Accelerator System for Food Irradiation Applications

    International Nuclear Information System (INIS)

    In December 2004 the US Food and Drug Administration (FDA) approved the use of 7.5 MeV X-rays for irradiation of food products. The increased efficiency for treatment at 7.5 MeV (versus the previous maximum allowable X-ray energy of 5 MeV) will have a significant impact on processing rates and, therefore, reduce the per-package cost of irradiation using X-rays. Titan Pulse Sciences Division is developing a new food irradiation system based on this ruling. The irradiation system incorporates a 7.5 MeV electron linear accelerator (linac) that is capable of 100 kW average power. A tantalum converter is positioned close to the exit window of the scan horn. The linac is an RF standing waveguide structure based on a 5 MeV accelerator that is used for X-ray processing of food products. The linac is powered by a 1300 MHz (L-Band) klystron tube. The electrical drive for the klystron is a solid state modulator that uses inductive energy store and solid-state opening switches. The system is designed to operate 7000 hours per year. Keywords: Rf Accelerator, Solid state modulator, X-ray processing

  7. 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.)

  8. 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

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

    Science.gov (United States)

    Anjum, Arshiya; Vinayakprasanna, N. H.; Pradeep, T. M.; Pushpa, N.; Krishna, J. B. M.; Gnana Prakash, A. P.

    2016-07-01

    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 (Vth), density of interface trapped charges (ΔNit), density of oxide trapped charges (ΔNot), transconductance (gm), mobility (μ), leakage current (IL) and drain saturation current (ID Sat) were studied as a function of dose. A considerable increase in ΔNit and ΔNot and decrease in Vth,gm, μ, and ID 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.

  10. Spectra and angular distributions of atmospheric gamma rays from 0.3 to 10 MeV at lambda = 40 deg

    Science.gov (United States)

    Ling, J. C.; Gruber, D. E.

    1977-01-01

    Measurements of the spectral and angular distributions of atmospheric gamma sq cm rays in the energy range 0.3-10 MeV over Palestine, Texas, at residual depths of 2.5 and 70 g/sq cm are reported. In confirmation of the general features of a model prediction, the measurements show at 2.5 g/sq cm upward moving fluxes greater than the downward moving fluxes, the effect increasing with energy, and approximate isotropy at 70 g/sq cm. Numerous characteristic gamma-ray lines were observed, most prominently at 0.511, 1.6, 2.3, 4.4, and 6.1 MeV. Their intensities were also compared with model predictions. Observations were made with an actively shielded scintillator counter with two detectors, one of aperture 50 deg FWHM and the other of 120 deg FWHM. Above 1 MeV, contributions to the counting rate from photons penetrating the shield annulus and from neutron interactions were large; they were studied by means of a Monte Carlo code and are extensively discussed.

  11. Neutron spectra produced by 30, 35 and 40 MeV proton beams at KIRAMS MC-50 cyclotron with a thick beryllium target

    Science.gov (United States)

    Shin, Jae Won; Bak, Sang-In; Ham, Cheolmin; In, Eun Jin; Kim, Do Yoon; Min, Kyung Joo; Zhou, Yujie; Park, Tae-Sun; Hong, Seung-Woo; Bhoraskar, V. N.

    2015-10-01

    Neutrons over a wide range of energies are produced by bombarding a 1.05 cm thick beryllium target with protons of different energies delivered by the MC-50 Cyclotron of the Korea Institute of Radiological Medical Sciences (KIRAMS). The neutron flux Φ(En) versus neutron energy En, produced by protons of 30, 35, and 40 MeV energies, was obtained by using the GEANT4 code with a data-based hadronic model. For the experimental validation of the simulated neutron spectra, a number of pure aluminum and iron oxide samples were irradiated with the neutrons produced by 30, 35, and 40 MeV protons at 20 μA beam current. The gamma-ray activities of 24Na and 56Mn produced, respectively, through 27Al(n,α)24Na and 56Fe(n,p)56Mn reactions were measured by a HPGe detector. The neutron flux Φ(En) at each neutron energy from the simulation was multiplied with the evaluated cross-sections σ(En) of the respective nuclear reaction, and the summation ∑ Φ(En) σ(En) was calculated over the neutron spectrum for each proton energy of 30, 35, and 40 MeV. The measured gamma-ray activities of 24Na and 56Mn were found in good agreement with the activities estimated by using the summed values of ∑ Φ(En) σ(En) along with other parameters in a neutron activation method.

  12. Neutron flux from a 14-MeV neutron generator with tungsten filter for research in NDA methods for nuclear safeguards and security

    International Nuclear Information System (INIS)

    The Joint Research Centre has taken into operation a new experimental device designed for research in the fields of nuclear safeguards and security applications. The research projects currently undertaken include detection of shielded contraband materials, detection of fissile materials, and mass determination of small fissile materials in shielded containers. The device, called the Pulsed Neutron Interrogation Test Assembly (PUNITA), incorporates a pulsed 14-MeV (D-T) neutron generator and a large graphite mantle surrounding the sample cavity. By pulsing the neutron generator with a frequency in the range of 10 to 150 Hz, a sample may be interrogated first by fast neutrons and a few hundred micro-seconds later by a pure thermal neutron flux. The permanent detection systems incorporated in PUNITA include 3He neutrons detectors, HPGe gamma detectors, and lanthanum bromide scintillation detectors.We have studied the effects of placing a tungsten liner around the neutron generator target. The 14-MeV neutrons induce (n, 2n) and (n, 3n) reactions. In addition the mean neutron energy emitted from generator/tungsten assembly is reduced to about 1 MeV. Both of these effects increase the thermal neutron flux in the sample cavity. The paper describes the observed advantages of the tungsten liner with respect to increase in thermal flux, and better shielding capabilities of the nearby gamma and neutron detectors.

  13. Gamma-radiation with E gamma 5 MeV detected from Seyfert galaxy 3C120 and region with 1" = 190 deg and b" = 20 deg

    Science.gov (United States)

    Damle, S. V.; Fradkin, M. I.; Iyudin, A. F.; Kirillov-Ugryumov, V. G.; Kotov, Y. D.; Kurnosova, L. V.; Smirnov, Y. V.; Yurov, V. N.

    1985-01-01

    The observation of the Galaxy anticenter region in gamma-rays with E gamma = 5 / 100 MeV was made by gamma-telescope Natalya-1 in a balloon flight. The flight was performed at the ceiling 5.1 + or - 0.1 g/sq cm, magnetic cutoff being 17 GV. The description of the instrument and the analysis of the experiment conditions are given. The tracks of electron-positron pairs generated by gamma-quanta in the convertors were detected by wire spark chambers. The recorded events were classified manually by an operator using a graphic display into three classes: pairs, single and bad events. The arrival angle of gamma-quanta and their energy for selected gamma-ray events (pairs and singles) were determined through multiple scattering of pair components in the convertors. On the basis of the data obtained the celestial maps were made in gamma-rays for E sub gamma 5 MeV and E gamma 20 MeV energy ranges.

  14. Yield of isomers in 76Ge (635 MeV) + 198Pt deep-inelastic collision and their dependence on projectiles (74,76Ge) and beam energies (635,550 MeV)

    International Nuclear Information System (INIS)

    We report the yields and distribution of ns-μs isomers produced in 76Ge (635 MeV) + 198Pt deep-inelastic collision. The population yields of isomers evaluated for individual channel and compared with the relevant yields produced in 76Ge (635 MeV) + 198Pt and 74Ge (550 MeV) + 198Pt reaction. These comparisons reflect how isomer yield depends on beam energies and projectile mass in deep-inelastic collisions. (author)

  15. Laser Range Sensors

    Directory of Open Access Journals (Sweden)

    K.C. Bahuguna

    2007-11-01

    Full Text Available This paper presents the design aspects of laser range finders and proximity sensors being developed at IRDE for different applications. The principle used in most of the laser range finders is pulse echo or time-of-flight measurement. Optical triangulation is used in proximity sensors while techniques like phase detection and interferometry are employed in instruments for surveying and motion controllers where high accuracy is desired. Most of the laser range finders are designed for ranging non-cooperative targets.

  16. Dosimetry of a 3-5 MeV linear electron accelerator for radiation processing

    International Nuclear Information System (INIS)

    With the multiple uses of a 3-5 MeV linear electron accelerator of the Institute of Low Energy Nuclear Physics (Beijing Radiation Center) at Beijing Normal University, the dosimetry of the linac for radiation processing has been studied. The graphite and water calorimeters have been used for routine dosimeter calibrations and reference measurements of absorbed dose for 4 MeV electron beam. Under the same irradiation condition, the polymer-alanine/ESR film and RCD dosimeters were calibrated in order to be used for routine process control. The polymer-alanine/ESR film dosimeter was also used as a transfer dosimeter for both 60Co gamma rays and 4 MeV electron beam because of its good dosimetric properties. (author)

  17. Development of 6 MeV X-band accelerator for next generation radiation therapy

    International Nuclear Information System (INIS)

    We are developing a 6 MeV X-band accelerator for the next generation radiation therapy. This accelerator is a compact LINAC about the length 60 [cm] and accelerates electron beam of 100 [mA] and 6 [MeV] . The RF power source is a small magnetron with 1.5 – 2.0 [MW] output. Various computer simulations were used for the design of the accelerator. The accelerator parts were processed using super-precision lathe and were joined by brazing. In the experiment of the completed accelerator, the energy of 6 [MeV] and beam current of 100 [mA] were observed. The accelerator is attached on a robot manipulator for medical treatment machine. In order to be certified for as a medical equipment, various tests are presently being carried out now. In this paper we described the design and measurements of the X-band accelerator. (author)

  18. Phase Shift Analyses of pp Elastic Scattering between 500 and 800 MeV

    Science.gov (United States)

    Nagata, J.; Yoshino, H.; Matsuda, M.

    1995-03-01

    The single-energy phase-shift analyses of pp elastic scattering have been made by using double-spin and triple-spin correlation parameters measured at SIN in the incident energy region TL = 447-580 MeV, and at LAMPF at TL = 735 MeV. The scattering amplitudes have been almost uniquely determined at TL = 500, 530, 560, 580 and 735 MeV. The Argand diagrams of 1D2-, 3P2- and 3F3-wave amplitudes show counter clockwise behavior. The obtained I = 1 amplitudes in the present analysis will contribute to the determination of the I = 0 amplitudes of np scattering in the same energy region.

  19. Resonance frequency control for the KOMAC 100-MeV drift tube linac

    Science.gov (United States)

    Kwon, Hyeok-Jung

    2015-02-01

    A 100-MeV proton accelerator has been developed, and the operation and beam service started at the Korea Multi-purpose Accelerator Complex (KOMAC) in July 2013. The accelerator consists of a 50-keV proton injector, a 3-MeV radio-frequency quadrupole (RFQ) and a 100-MeV drift tube linac (DTL). The resonance frequencies of the DTL tanks are controlled by using the resonance frequency control cooling system (RCCS), installed at every DTL tank. Until now, the RCCS has been operating in the constant temperature mode. If the system is to be stabilized better, the RCCS must be operated in the frequency control mode. For this purpose, studies, including the relation between the resonance frequency and RCCS operation temperature, were done under various conditions. In this paper, the preparations for the frequency control loop of the RCCS are described.

  20. On the Positronium Continuum and 0.511 MeV Line in Solar Flares

    Institute of Scientific and Technical Information of China (English)

    Wei-Qun Gan; Jin Chang; You-Ping Li; Yang Su; L.I.Miroshnichenko

    2004-01-01

    We have studied the influence of the density of the annihilation region on the positronium continuum.A relation between the ratio 3γ/2γ and the density is explicitly given,with which one can derive directly from the observed 3γ/2γthe density where the annihilation occurs.A unique solution may be found from the observed width of the 0.511 MeV line.We applied the method to three flares observed by GRS/SMM.It is shown that due to the measuring uncertainties in the 0.511 MeV line width,we cannot distinguish a chromospheric source from a coronal source,though both accurately localized.To improve the measuring accuracy of the 0.511 MeV line and the ratio 3γ/2γ will be an important step for a better understanding of the annihilation process in solar flares.

  1. A sub-picosecond pulsed 5 MeV electron beam system

    International Nuclear Information System (INIS)

    Laser excited pulsed, electron beam systems that operate at energies from 1 MeV up to 5 MeV and pulse width from 0.1 to 100 ps are described. The systems consist of a high voltage pulser and a coaxial laser triggered gas or liquid spark gap. The spark gap discharges into a pulse forming line designed to produce and maintain a flat voltage pulse for 1 ns duration on the cathode of a photodiode. A synchronized laser is used to illuminate the photocathode with a laser pulse to produce an electron beam with very high brightness, short duration, and current at or near the space charge limit. Operation of the system is described and preliminary test measurements of voltages, synchronization, and jitter are presented for a 5 MeV system. Applications in chemistry, and accelerator research are briefly discussed

  2. 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.

  3. RF phase stability in the 100-MeV proton linac operation

    Science.gov (United States)

    Seol, Kyung-Tae

    2015-02-01

    The 100-MeV proton linac of the Korea multi-purpose accelerator complex (KOMAC) has been operated to provide a proton beam to users. The 100-MeV linac consists of a 3-MeV radio-frequency quadrupole accelerator (RFQ), four 20-MeV drift-tube linac (DTL) tanks, two medium-energy beam-transmitter (MEBT) tanks, and seven 100-MeV DTL tanks. The requirements of the field stability are within ±1% in RF amplitude and ±1 degree in RF phase. The RF phase stability is influenced by a RF reference line, RF transmission lines, and a RF control system. The RF reference signal is chosen to be a 300-MHz local oscillator (LO) signal, and a rigid copper coaxial line with temperature control was installed for an RF reference distribution. A phase stability of ±0.1 degrees was measured under a temperature change of ±0.1 °C. A digital feedback control system with a field-programmable gate-array (FPGA) module was adopted for a high RF stability. The RF phase was maintained within ±0.1 degrees with a dummy cavity and was within ±0.3 degrees at RFQ operation. In the case of the 20-MeV DTL tanks, one klystron drives 4 tanks, and the input phases of 4 tanks were designed to be in phase. The input phases of 4 tanks were fixed within ±1 degree by adjusting a phase shifter in each waveguide.

  4. Characterization of PARIS LaBr3(Ce)-NaI(Tl) phoswich detectors up to Eγ ~ 22 MeV

    Science.gov (United States)

    Ghosh, C.; Nanal, V.; Pillay, R. G.; Anoop, K. V.; Dokania, N.; Pal, Sanjoy; Pose, M. S.; Mishra, G.; Rout, P. C.; Kumar, Suresh; Pandit, Deepak; Mondal, Debasish; Pal, Surajit; Banerjee, S. R.; Napiorkowski, P. J.; Dorvaux, O.; Kihel, S.; Mathieu, C.; Maj, A.

    2016-05-01

    In order to understand the performance of the PARIS (Photon Array for the studies with Radioactive Ion and Stable beams) detector, detailed characterization of two individual phoswich (LaBr3(Ce)-NaI(Tl)) elements has been carried out. The detector response is investigated over a wide range of Eγ = 0.6 to 22.6 MeV using radioactive sources and employing 11B(p,γ) reaction at Ep = 163 keV and Ep = 7.2 MeV . The linearity of energy response of the LaBr3(Ce) detector is tested upto 22.6 MeV using three different voltage dividers. The data acquisition system using CAEN digitizers is set up and optimized to get the best energy and time resolution. The energy resolution of ~ 2.1% at Eγ = 22.6 MeV is measured for the configuration giving best linearity up to high energy. Time resolution of the phoswich detector is measured with a 60Co source after implementing CFD algorithm for the digitized pulses and is found to be excellent (FWHM ~ 315 ps). In order to study the effect of count rate on detectors, the centroid position and width of the Eγ = 835 keV peak were measured upto 220 kHz count rate. The measured efficiency data with radioactive sources are in good agreement with GEANT4 based simulations. The total energy spectrum after the add-back of energy signals in phoswich components is also presented.

  5. Exploratory study of fission product yields of neutron-induced fission of 235U , 238U , and 239Pu at 8.9 MeV

    Science.gov (United States)

    Bhatia, C.; Fallin, B. F.; Gooden, M. E.; Howell, C. R.; Kelley, J. H.; Tornow, W.; Arnold, C. W.; Bond, E.; Bredeweg, T. A.; Fowler, M. M.; Moody, W.; Rundberg, R. S.; Rusev, G. Y.; Vieira, D. J.; Wilhelmy, J. B.; Becker, J. A.; Macri, R.; Ryan, C.; Sheets, S. A.; Stoyer, M. A.; Tonchev, A. P.

    2015-06-01

    Using dual-fission chambers each loaded with a thick (200 -400 -mg /c m2) actinide target of 235 ,238U or 239Pu and two thin (˜10 -100 -μ g /c m2) reference foils of the same actinide, the cumulative yields of fission products ranging from 92Sr to 147Nd have been measured at En= 8.9 MeV . The 2H(d ,n ) 3He reaction provided the quasimonoenergetic neutron beam. The experimental setup and methods used to determine the fission product yield (FPY) are described, and results for typically eight high-yield fission products are presented. Our FPYs for 235U(n ,f ) , 238U(n ,f ) , and 239Pu(n ,f ) at 8.9 MeV are compared with the existing data below 8 MeV from Glendenin et al. [Phys. Rev. C 24, 2600 (1981), 10.1103/PhysRevC.24.2600], Nagy et al. [Phys. Rev. C 17, 163 (1978), 10.1103/PhysRevC.17.163], Gindler et al. [Phys. Rev. C 27, 2058 (1983), 10.1103/PhysRevC.27.2058], and those of Mac Innes et al. [Nucl. Data Sheets 112, 3135 (2011), 10.1016/j.nds.2011.11.009] and Laurec et al. [Nucl. Data Sheets 111, 2965 (2010), 10.1016/j.nds.2010.11.004] at 14.5 and 14.7 MeV, respectively. This comparison indicates a negative slope for the energy dependence of most fission product yields obtained from 235U and 239Pu , whereas for 238U the slope issue remains unsettled.

  6. Attenuation of 10 MeV electron beam energy to achieve low doses does not affect Salmonella spp. inactivation kinetics

    Science.gov (United States)

    Hieke, Anne-Sophie Charlotte; Pillai, Suresh D.

    2015-05-01

    The effect of attenuating the energy of a 10 MeV electron beam on Salmonella inactivation kinetics was investigated. No statistically significant differences were observed between the D10 values of either Salmonella 4,[5],12:i:- or a Salmonella cocktail (S. 4,[5],12:i:-, Salmonella Heidelberg, Salmonella Newport, Salmonella Typhimurium, Salmonella) when irradiated with either a non-attenuated 10 MeV eBeam or an attenuated 10 MeV eBeam (~2.9±0.22 MeV). The results show that attenuating the energy of a 10 MeV eBeam to achieve low doses does not affect the inactivation kinetics of Salmonella spp. when compared to direct 10 MeV eBeam irradiation.

  7. 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...

  8. Substring Range Reporting

    DEFF Research Database (Denmark)

    Bille, Philip; Gørtz, Inge Li

    2011-01-01

    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...

  9. 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.

  10. The analysis on dynamic range of industrial CT system

    International Nuclear Information System (INIS)

    Concerning the limitations of the definition of the dynamic range of industrial computed tomography (ICT) system, it researches the definition, measuring method and influencing factors of the dynamic range of industrial computed tomography (ICT) system from the concept of quantization and system. First, the character of the input-output curve was analyzed, and the method of obtaining the dynamic range of industrial computed tomography (ICT) system was proposed. Then, an experiment model was designed to gain dynamic range, based on 6 MeV high-energy industrial computed tomography (ICT) system. The results show that the larger the photosurface is, the smaller the dynamic range is, when the other parameters are unchanged. (authors)

  11. The KAERI 10 MeV Electron Linac - Description and Operational Manual

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Byung Cheol; Park, Seong Hee; Jung, Young Uk; Han, Young Hwan; Kang, Hee Young

    2005-06-15

    The objective of this technical report is to guide the right operation and maintenance of the KAERI electron linac system. The KAERI electron linac system consists of 2 MeV injector based on 176 MHz Normal conducting RF (Radio Frequency)cavity and 10 MeV main accelerator based on 352 MHz Superconducting RF cavity, electron beamlines (injection and extraction). Since a electron accelerator generates hazard radiation, this system is located at the shielded room in basement and we can operate the system using the remote control system. It includes the description and the operational manual as well as the detailed technical direction for trouble shooting.

  12. Design of an MeV ultra-fast electron diffraction experiment at Tsinghua university

    Institute of Scientific and Technical Information of China (English)

    LI Ren-Kai; TANG Chuan-Xiang; HUANG Wen-Hui; DU Ying-Chao; SHI Jia-Ru; YAN Li-Xin

    2009-01-01

    Time-resolved MeV ultra-fast electron difiraction(UED)is a powerful tool for structure dynamics studies.In this paper.we present a design of a MeV UED facility based on a photocathode RF gun at Tsinghua University.Electron beam qualities are optimized with numerical simulations,indicating that resolutions of 250 fs and 0.01 A.and bunch charge exceeding 105 electrons are expected with technically achievable machine parameters.Status of experiment preparation is also presented.

  13. Using 3.05 MeV resonance for determination of oxygen impurities

    International Nuclear Information System (INIS)

    The method of determining oxygen impurities behind thin films using the isolated resonance in the 16O(α, α)16O reaction at E=3.048 MeV with the width GITA approximately 20 keV, is considered. Cross section in resonance is σsUb(R) = 0.95 b apd it increases cross section of Rutherford scattering by the factor of 25. The conclusion is made on the possibility of using 3.048 MeV resonance when investigating Me-Si film structures

  14. Observation of an eta'/sub c/ candidate state with mass 3592 +- 5 MeV

    International Nuclear Information System (INIS)

    An eta'/sub c/ candidate state is observed at a mass M = 3592 +- 5 MeV and with a natural linewidth GAMMA<8 MeV (95% confidence level), by using the ''crystal ball'' NaI(Tl) detector at the Stanford Linear Accelerator Center (SPEAR). The evidence is found in the inclusive photon spectrum in decays of the psi'(3684), where a signal is observed corresponding to a radiative transition to this state with branching ratio between 0.2% and 1.3%

  15. 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.

  16. Beam Loss by Lorentz Stripping in a 100 MeV Compact H~- Cyclotron

    Institute of Scientific and Technical Information of China (English)

    Larry; Root

    2002-01-01

    The success of TRIUMF’s ISAC facility demonstrates that a 500 MeV 100 μ A H cyclotron is agood choice for the driver stage of an ISOL type RIB facility. As a result, China Institute of AtomicEnergy is proposing the construction of a 75~100 MeV 200~500μA H~- cyclotron as an upgrade to theBeijing Tandem Laboratory. This would be a multiple user facility, which would include a RIB target

  17. Static electron gun power supplies for 3 MeV DC accelerator

    International Nuclear Information System (INIS)

    A DC accelerator is designed to operate with beam energy of 1 MeV - 3 MeV and beam current of 0-10 mA. The electron beam is generated by a thermionic emission electron gun. The gun is floating at 3 Million Volts and requires regulated and controllable power supplies for its Anode and Filament respectively. This requires generation of about 400 W on the 3 MV terminal and conditioning it to the desired voltages and power levels with remote control facility as per beam requirement. The paper describes briefly about the design aspects and test results. (author)

  18. Properties of the {sup 12}C 10 MeV state determined through {beta}-decay

    Energy Technology Data Exchange (ETDEWEB)

    Diget, C.A. [Department of Physics and Astronomy, University of Aarhus, DK-8000 Aarhus C (Denmark); Barker, F.C. [Department of Theoretical Physics, Research School of Physical Sciences and Engineering, Australian National University, Canberra ACT 0200 (Australia); Borge, M.J.G. [Instituto Estructura de la Materia, CSIC, E-28006 Madrid (Spain); Cederkaell, J. [ISOLDE-CERN, CH-1211 Geneva 23 (Switzerland); Fedosseev, V.N. [ISOLDE-CERN, CH-1211 Geneva 23 (Switzerland); Fraile, L.M. [ISOLDE-CERN, CH-1211 Geneva 23 (Switzerland); Fulton, B.R. [Department of Physics, University of York, Heslington, YO10 5DD (United Kingdom); Fynbo, H.O.U. [Department of Physics and Astronomy, University of Aarhus, DK-8000 Aarhus C (Denmark)]. E-mail: fynbo@phys.au.dk; Jeppesen, H.B. [Department of Physics and Astronomy, University of Aarhus, DK-8000 Aarhus C (Denmark); Jonson, B. [Fundamental Fysik, Chalmers Tekniska Hoegskola, S-412 96 Goeteborg (Sweden); Koester, U. [ISOLDE-CERN, CH-1211 Geneva 23 (Switzerland); Meister, M. [Fundamental Fysik, Chalmers Tekniska Hoegskola, S-412 96 Goeteborg (Sweden); Nilsson, T. [ISOLDE-CERN, CH-1211 Geneva 23 (Switzerland); Nyman, G. [Fundamental Fysik, Chalmers Tekniska Hoegskola, S-412 96 Goeteborg (Sweden); Prezado, Y. [Instituto Estructura de la Materia, CSIC, E-28006 Madrid (Spain); Riisager, K. [Department of Physics and Astronomy, University of Aarhus, DK-8000 Aarhus C (Denmark); Rinta-Antila, S. [Department of Physics, University of Jyvaeskylae, FIN-40351 Jyvaeskylae (Finland); Tengblad, O. [Instituto Estructura de la Materia, CSIC, E-28006 Madrid (Spain); Turrion, M. [Instituto Estructura de la Materia, CSIC, E-28006 Madrid (Spain); Wilhelmsen, K. [Fundamental Fysik, Chalmers Tekniska Hoegskola, S-412 96 Goeteborg (Sweden); Aeystoe, J. [Department of Physics, University of Jyvaeskylae, FIN-40351 Jyvaeskylae (Finland); Helsinki Institute of Physics, University of Helsinki, FIN-00014 Helsinki (Finland)

    2005-10-03

    The {beta}-delayed triple-{alpha} particle decay of {sup 12}B has been measured with a setup that favours coincidence detection. A broad state in {sup 12}C, previously reported around 10 MeV, has been seen and its properties determined through R-matrix analysis of the excitation spectrum. The spin and parity are 0{sup +}. Interference between this state and the Hoyle state at 7.654 MeV has a marked influence on the spectrum. The coupling between the two states makes it difficult to determine the resonance energy.

  19. 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.

  20. 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.

  1. The physics design of magnet in 14 MeV cyclotron

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    The 14 MeV, 400 μA compact cyclotron is under construction at China Institute of Atomic Energy (CIAE). The design of main magnet and the result of beam dynamics in the cyclotron will be described in this paper, including the choice of main parameters of magnet, the method of shimming isochronous field in the compact cyclotron and optimization of the magnetic field in central region. The beam will be accelerated to 14.6 MeV by optimizing the magnet structure.

  2. Calibration of scintillation detectors for MeV charged fusion products

    International Nuclear Information System (INIS)

    The light output of ZnS scintillators used to detect escaping fusion products in the TFTR Tokamak is studied with 3.5 MeV alpha and 3 MeV proton beams. The emitted light first increases linearly with beam current and then saturates. In all cases investigated, the onset of the saturation corresponds to a power of about 1 mW absorbed within the ZnS powder. The scintillators have adequate time response up to 50--100 kHz

  3. Radiation hardness of a single crystal CVD diamond detector for MeV energy protons

    Energy Technology Data Exchange (ETDEWEB)

    Sato, Yuki, E-mail: y.sato@riken.jp [The Institute of Physical and Chemical Research (RIKEN), 2-1 Hirosawa, Wako, Saitama 351-0198 (Japan); Shimaoka, Takehiro; Kaneko, Junichi H. [Graduate School of Engineering, Hokkaido University, N13, W8, Sapporo 060-8628 (Japan); Murakami, Hiroyuki [The Institute of Physical and Chemical Research (RIKEN), 2-1 Hirosawa, Wako, Saitama 351-0198 (Japan); Isobe, Mitsutaka; Osakabe, Masaki [National Institute for Fusion Science, 322-6, Oroshi-cho Toki-city, Gifu 509-5292 (Japan); Tsubota, Masakatsu [Graduate School of Engineering, Hokkaido University, N13, W8, Sapporo 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, Shinichi [National Institute of Advanced Industrial Science and Technology (AIST), 1-8-31 Midorigaoka, Ikeda, Osaka 563-8577 (Japan)

    2015-06-01

    We have fabricated a particle detector using single crystal diamond grown by chemical vapor deposition. The irradiation dose dependence of the output pulse height from the diamond detector was measured using 3 MeV protons. The pulse height of the output signals from the diamond detector decreases as the amount of irradiation increases at count rates of 1.6–8.9 kcps because of polarization effects inside the diamond crystal. The polarization effect can be cancelled by applying a reverse bias voltage, which restores the pulse heights. Additionally, the radiation hardness performance for MeV energy protons was compared with that of a silicon surface barrier detector.

  4. Interaction of MeV ions and VUV photons with polymers and high molecular hydrocarbons

    Science.gov (United States)

    Mahfouz, R. M.; Sauer, M.; Atwa, S. T.; Kaiser, R. I.; Roessler, K.

    1992-03-01

    Organic solids such as polymethylene, polyethylene, polyoxymethylene, aliphatic and cyclic paraffins, naphthalene, anthracene and kerogen were irradiated at 77 K with 10-20 MeV cyclotron ions (p, 3He) and up to 10 eV photons. The products were analysed by quadrupole mass spectrometry (QMS). Fourier transform infrared spectroscopy (FT-IR), Raman spectroscopy and gas chromatography (GC). Besides radiolytic fragmentation, also synthesis of new and complex compounds was observed as a consequence of hot carbon chemistry. Vacuum ultraviolet (VUV) irradiation proved to be less effective in the buildup of new structures than MeV ions, due to its lower linear energy transfer.

  5. Development of accelerating structure of 9 MeV C-band electron linac

    International Nuclear Information System (INIS)

    In this paper, the design and performance characteristics of accelerating guide for C-band SW electron linac are discussed. The guide can accelerate electrons to 9 MeV or 6 MeV. Its length is about 620mm, and a Pierce electron gun has been used. A 2.5MW pulsed magnetron at 5712 MHz is served as the guide's RF power source. The two energy modes are performed by turning RF power source and the injecting voltage of electron gun. (authors)

  6. 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

  7. 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).

  8. 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

  9. 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.

  10. The design study for a 500 MeV proton synchrotron with CSNS linac as an injector

    CERN Document Server

    Huang, Liang-Sheng; Ji, Hong-Fei

    2016-01-01

    Using the China Spallation Neutron Source (CSNS) linac as the injector, a 500 MeV proton synchrotron is proposed for multidisciplinary application, such as biology, material and proton therapy. The synchrotron will deliver proton beam with energy from 80 MeV to 500 MeV. A compact lattice design was worked out, and all the important beam dynamics issues were investigated. The 80 MeV H- beam is stripped and injected into the synchrotron by using multi-turn injection. In order to continuously extraction the proton with small beam loss, the achromatic structure is proposed and slow extraction method with RF knock-out is adopted and optimized.

  11. Stopping of 236 keV - 3.019 MeV protons in mylar and polypropylene films

    Science.gov (United States)

    Damache, S.; Ouichaoui, S.; Belhout, A.; Medouni, A.; Toumert, I.

    2004-10-01

    The stopping powers of polypropylene and mylar polymers for protons have been accurately measured over the energy intervals Ep=(0.352-3.009) MeV and Ep=(0.236-3.019) MeV, respectively. Ab initio calculations using the Sigmund-Schinner binary collision theory for electronic stopping yielded S( E) values fairly consistent with the measured data that show no noticeable deviations from the Bragg-Kleeman additivity rule. The data have also been analyzed in the framework of the modified Bethe-Bloch theory assuming additivity. Values of the mean excitation and ionization potential, I, and of the Barkas parameter, b, have been deduced for the two polymers and for their (C, O) atomic constituents by adopting values of these parameters recommended in the ICRU-49 report for the H element. Thus, the respective I-values {(56.90 ± 0.72) eV, (79.92 ± 1.30) eV} for the two polymers and the same b-value 1.39 for their (C, O) atomic constituents have been determined by adopting for H the value b=1.8, while the I-values {(81.73 ± 1.38) eV, (109.46 ± 6.55) eV} have been deduced for the (C, O) constituents by adopting for H the value I=19.2 eV. Priorily, the shell, Barkas and Bloch corrections to the calculated S( E) values have been evaluated for both polymers over the explored respective energy ranges. The obtained results are discussed in comparison with previous ones when reported in the literature to our knowledge.

  12. Range_Extent_15

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The GIS layer "Range_extent_15" is a simple polyline representing the geographic distribution of the southern sea otter (Enhydra lutris nereis) in mainland...

  13. Atlantic Test Range (ATR)

    Data.gov (United States)

    Federal Laboratory Consortium — ATR controls fully-instrumented and integrated test ranges that provide full-service support for cradle-to-grave testing. Airspace and surface target areas are used...

  14. Correlation radio range finder

    Directory of Open Access Journals (Sweden)

    A. Sorochan

    2012-10-01

    Full Text Available In work widely known methods of range measuring are short characterized. The basic attention is given features of signal processing in a correlation method of range measuring. The signal with angular modulation with one-voice-frequency fluctuation is used as a probing signal. The absence of Doppler effect on the formation of the correlation integral, the frequency instability of the transmitter, the phase change on reflection from the target is presented. It is noticed that the result of signal processing in the range measuring instrument is reduced to formation on an exit one-voice-frequency harmonious fluctuation equal to modulating frequency that provides high characteristics of a radio range finder.

  15. Light Detection And Ranging

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — LiDAR (Light Detection and Ranging) discrete-return point cloud data are available in the American Society for Photogrammetry and Remote Sensing (ASPRS) LAS format....

  16. 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...

  17. PHOTONS IN THE PROTON-INDUCED REACTION WITH IN AT E(P)=50-MEV

    NARCIS (Netherlands)

    BALANDA, A; BACELAR, JCS; BETAK, E; BORDEWIJK, JA; KRASZNAHORKA, A; VANDERPLOEG, H; SIEMSSEN, RH; WILSCHUT, HW; VANDERWOUDE, A

    1994-01-01

    Photon emission in proton-induced reactions at 50 MeV with In-115 was studied. Analyses of the measured photon spectrum show that the GDR couples to the compound states as well as to pre-equilibrium states. The centroid and width of the GDR strength function were determined as E(GDR) = 15.4 +/- 0.7

  18. Flare vs. Shock Acceleration of >100 MeV Protons in Large Solar Particle Events

    Science.gov (United States)

    Cliver, Edward W.

    2016-05-01

    Recently several studies have presented correlative evidence for a significant-to-dominant role for a flare-resident process in the acceleration of high-energy protons in large solar particle events. In one of these investigations, a high correlation between >100 MeV proton fluence and 35 GHz radio fluence is obtained by omitting large proton events associated with relatively weak flares; these outlying events are attributed to proton acceleration by shock waves driven by coronal mass ejections (CMEs). We argue that the strong CMEs and associated shocks observed for proton events on the main sequence of the scatter plot are equally likely to accelerate high-energy protons. In addition, we examine ratios of 0.5 MeV electron to >100 MeV proton intensities in large SEP events, associated with both well-connected and poorly-connected solar eruptions, to show that scaled-up versions of the small flares associated with classical impulsive SEP events are not significant accelerators of >100 MeV protons.

  19. Multi-turn injection of 50 MeV protons into the CERN Proton Synchrotron booster

    CERN Document Server

    Raginel, V; Carli, C; Mikulec, B

    2013-01-01

    Since 1978, Linac2 produces beams of 50 MeV protons with a current around 160 mA, which are injected into the CERN Proton Synchrotron Booster (PSB) with conventional multi-turn injection using a horizontal septum. It is planned to replace Linac2 during a future long stop with a new H- linac, Linac4, injecting at higher energy (160 MeV) and making use of the modern chargeexchange injection principle. Due to the age of Linac2 and to a delicate vacuum situation the risk of a serious Linac2 breakdown has to be considered. Therefore it is necessary to study if the PSB could produce beams useful for the LHC and other experiments injecting a Linac4 proton beam at 50 MeV with much lower average current compared to Linac2 and without the need for a long installation of the 160 MeV H- injection hardware. Benchmarking of the PSB injection model with the existing injection system with Linac2 using the ORBIT code has been done for a LHC-type beam and then the injection model was used to estimate the brightness for LHC-typ...

  20. Multi-turn injection of 50 MeV protons into the CERN Proton Synchrotron Booster

    CERN Document Server

    Raginel, V; Carli, C; Mikulec, B

    2013-01-01

    Since 1978, Linac2 produces beams of 50 MeV protons with a current around 160 mA, which are injected into the CERN Proton Synchrotron Booster (PSB) with conventional multi-turn injection using a horizontal septum. It is planned to replace Linac2 during a future long stop with a new H- linac, Linac4, injecting at higher energy (160 MeV) and making use of the modern chargeexchange injection principle. Due to the age of Linac2 and to a delicate vacuum situation the risk of a serious Linac2 breakdown has to be considered. Therefore it is necessary to study if the PSB could produce beams useful for the LHC and other experiments injecting a Linac4 proton beam at 50 MeV with much lower average current compared to Linac2 and without the need for a long installation of the 160 MeV H- injection hardware. Benchmarking of the PSB injection model with the existing injection system with Linac2 using the ORBIT code has been done for a LHC-type beam and then the injection model was used to estimate the brightness for LHC-typ...

  1. Fixed fluorescent images of an 80 MeV proton pencil beam

    NARCIS (Netherlands)

    Warman, J. M.; de Haas, M. P.; Luthjens, L. H.; Denkova, A. G.; Kavatsyuk, O.; van Goethem, M. -J.; Kiewiet, H. H.; Brandenburg, S.

    2013-01-01

    We have used an organic radio-fluorogenic gel to make fixed fluorescent images of the track of an 80 MeV proton pencil beam NB this is not a scintillation effect; rather a small fraction of the molecules of the medium are converted permanently from a non-emissive to an emissive form. The spatial res

  2. 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.

  3. 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 b

  4. Voltage holding study of 1 MeV accelerator for ITER neutral beam injector.

    Science.gov (United States)

    Taniguchi, M; Kashiwagi, M; Umeda, N; Dairaku, M; Takemoto, J; Tobari, H; Tsuchida, K; Yamanaka, H; Watanabe, K; Kojima, A; Hanada, M; Sakamoto, K; Inoue, T

    2012-02-01

    Voltage holding test on MeV accelerator indicated that sustainable voltage was a half of that of ideal quasi-Rogowski electrode. It was suggested that the emission of the clumps is enhanced by a local electric field concentration, which leads to discharge initiation at lower voltage. To reduce the electric field concentration in the MeV accelerator, gaps between the grid supports were expanded and curvature radii at the support corners were increased. After the modifications, the accelerator succeeded in sustaining -1 MV in vacuum without beam acceleration. However, the beam energy was still limited at a level of 900 keV with a beam current density of 150 A∕m(2) (346 mA) where the 3 × 5 apertures were used. Measurement of the beam profile revealed that deflection of the H(-) ions was large and a part of the H(-) ions was intercepted at the acceleration grid. This causes high heat load on the grids and the breakdowns during beam acceleration. To suppress the direct interception, new grid system was designed with proper aperture displacement based on a 3D beam trajectory analysis. As the result, the beam deflection was compensated and the voltage holding during the beam acceleration was improved. Beam parameter of the MeV accelerator was increased to 980 keV, 185 A∕m(2) (427 mA), which is close to the requirement of ITER accelerator (1 MeV, 200 A∕m(2)).

  5. Praseodymium activation detector for measuring bursts of 14 MeV neutrons

    Energy Technology Data Exchange (ETDEWEB)

    Meehan, Tim, E-mail: meehanbt@nv.doe.go [National Security Technologies, LLC, P.O. Box 98521, North Las Vegas, NV 89030 (United States); Hagen, E.C. [National Security Technologies, LLC, P.O. Box 98521, North Las Vegas, NV 89030 (United States); Ruiz, C.L.; Cooper, G.W. [Sandia National Laboratories, P.O. Box 5800, Albuquerque, NM 87185 (United States)

    2010-08-21

    A new, accurate, neutron activation detection scheme for measuring pulsed neutrons has been designed and tested. The detection system is sensitive to neutrons with energies above 10 MeV; importantly, it is insensitive to gamma radiation <10 MeV and to lower-energy (e.g., fission and thermal) neutrons. It is based upon the use of {sup 141}Pr, an element that has a single, naturally occurring isotope, a significant n,2n cross-section, and decays by positron emission that result in two coincident 511 keV photons. Neutron fluences are thus inferred by relating measured reaction product decay activity to fluence. Specific sample activity is measured using the sum-peak method to count gamma-ray coincidences from the annihilation of the positron decay products. The system was tested using 14 and 2.45 MeV neutron bursts produced by NSTec Dense Plasma Focus Laboratory fusion sources. Lead, copper, beryllium, and silver activation detectors were compared. The detection method allows measurement of 14 MeV neutron yield with a total error of {approx}18%.

  6. Design of a 10 MeV, 352.2 MHz drift tube Linac

    Indian Academy of Sciences (India)

    Nita S Kulkarni

    2012-08-01

    A conventional 10 MeV drift tube Linac is designed as a part of the - front end accelerator system for the future Indian Spallation Neutron Source. The front end Linac consists of a 50 keV H- ion source, low energy beam transport (LEBT), a 3 MeV radio frequency quadrupole (RFQ), and a 10 MeV drift tube Linac (DTL), which will be operated at 1.25% duty factor. Cell geometry of the DTL is optimized to house quadrupole magnets and to get maximum effective shunt impedance. Transmission efficiency and various other output parameters depend on the input design parameters. Beam dynamic studies are done to maximize the transmission efficiency with minimum emittance growth. Errors in the alignment of the quadrupoles inside the drift tubes or the DTL tank alignment with respect to transport line will degrade the beam quality and may reduce the transmission efficiency. Error study is performed to assess the acceptable tolerances on various parameters. This paper describes the 2D and 3D electromagnetic and beam dynamics simulations of the 352.2 MHz, 10 MeV drift tube Linac. Details of the DTL design are reported in this paper.

  7. 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...

  8. Test Scheme Setup for the PEFP 20MeV DTL

    CERN Document Server

    Kim, Han-Sung; Hwang, Yong-Suk; Kim, Yong-Hwan; Kwon, Hyeok-Jung; Tae Seol, Kyung

    2005-01-01

    A 100MeV proton accelerator is under development for the Proton Engineering Frontier Project (PEFP). The goal of the first stage of the project is to develop a 20MeV accelerator and the initial test of the 20MeV accelerator will be made. The DTL of 20 MeV accelerator consists of four tanks and will be driven with single klystron, which gives rise to some unique problems with regard to the way of independent resonance control for each tank. Some changes made in the LLRF for reducing phase or amplitude error of cavities affect all of four tanks simultaneously, for which it is not possible to use LLRF for individual control of phase and amplitude of each tank. For independent control of each tank, we are going to use the temperature control of the drift tubes as a frequency tuner. During the initial test of the DTL, the phase of each tank will be synchronized with the first tank phase, and beam based test will be performed as if all of tanks were single unit. The detailed description of the test scheme and the a...

  9. Scale size of magnetic turbulence in tokamaks probed with 30-MeV electrons

    NARCIS (Netherlands)

    Entrop, I.; Cardozo, N. J. L.; R. Jaspers,; Finken, K.H.

    2000-01-01

    Measurements of synchrotron radiation emitted by 30-MeV runaway electrons in the TEXTOR-94 tokamak show that the runaway population decays after switching on neutral beam injection (NBI). The decay starts only with a significant delay, which decreases with increasing NBI heating power. This delay pr

  10. Energy-dependent phase shift analysis of pion-nucleon scattering below 400 MeV

    International Nuclear Information System (INIS)

    An analytic function of energy is fit to the available S, P, and D wave πN phase shifts of various goups below 400 MeV. This global average, which reproduces well most of the experiment cross sections, is anticipated to be useful in pion-nucleus and pion-nucleon interaction calculations

  11. The pilot experimental study of 14 MeV fast neutron digital radiography

    Institute of Scientific and Technical Information of China (English)

    TANG Bin; ZHOU ChangGen; HUO HeYong; WU Yang; LIU Bin; LOU BenChao; SUN Yong

    2009-01-01

    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 ex-perimental 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 re-search.

  12. Radiological safety research of food irradiation with 7.5 MeV X-rays

    International Nuclear Information System (INIS)

    China and America both have 7.5 MeV high energy X-ray accelerator. The radiological safety of food irradiated with 7.5 MeV X-rays (bremsstrahlung) has been investigated. Samples of meat and meat ash were located in a large volume of fresh meat at the position of the highest photoneutron fluence and irradiated to an X-ray dose of 15 kGy, twice the maximum dose allowed by the US FDA for meat irradiation. An evaluation of the corresponding radiation exposure from ingestion of the irradiated product has been compared to natural background radiation. The paper concludes that the risk to individuals from intake of food irradiated with X-rays from 7.5 MeV electrons, even with a broad energy spectrum, would be trivial. The common target materials are Au, Ta and W. The U.S, requires only Au and Ta can be used as food irradiation target materials and China has not yet relevant provisions. The first 7.5 MeV accelerator for food irradiation in China is under built, and will do the explore research for the choice of target material. (authors)

  13. The pilot experimental study of 14 MeV fast neutron digital radiography

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    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.

  14. 15-16 MeV electron linear accelerators for nondestructive testing

    International Nuclear Information System (INIS)

    15-16 MeV electron linear accelerators for nondestructive testing (ND) are described. The accelerators are intended for ND of the articles with great thickness by means of radiographic, introscopic and tomographic methods. Main characteristics of these accelerators are presented. The automatic control system based on the PC compatible controllers is described in details

  15. Stopping powers for MeV Ge ions in Al foil

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    Stopping powers for Ge ions (3.5MeV~8.0MeV) in Al foil were measured with RBS (Rutherford backscattering) technique and determined with a new method. Our results are much smaller than the values predicted by the TRIM code and LSS theory.

  16. Proton irradiation of conventional and lithium solar cells - 11-37 MeV

    Science.gov (United States)

    Anspaugh, B. E.; Carter, J. R.

    1974-01-01

    Conventional n/p and lithium solar cells were irradiated with 11- to 37-MeV protons. The energy dependence of the solar cell degradation, calculated from electrical parameters and lifetime measurements, is shown to be very slight. Damage coefficients for the n/p cells are calculated. Annealing characteristics of both the lithium cells and the n/p cells are presented.

  17. 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.

  18. Simulation and Field Measurement of Quadrupole Magnets for KOMAC 20MeV Beam line

    Energy Technology Data Exchange (ETDEWEB)

    Chung, B. H.; Kim, H. S.; Song, Y. G.; Kwon, H. J.; Cho, Y. S. [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2014-05-15

    In this paper, quadrupole magnets the same as installed at the beam line simulated and analyzed for magnetic fields. Also quadrupole magnets will be measured field stability and evaluated reliability on long time operation. Control system consisted of Labview program and communication method consisted of Ethernet and Rs-232 with optical fiber for devices safety from high voltage and/or high current. As a results the DC power supply is controlled, magnetic fields data is acquired and coil temperature is measured. Magnetic field with hall sensor and temperature with K-type thermo-couple are measured with conversion factor using by voltmeter. Korea Multi-purpose Accelerator Complex (KOMAC) was developed at Gyeongju in Korea in 2012. KOMAC including a 50-keV ion source, a 3-MeV RFQ, and a 100-MeV DTL. And beam line consists of 20-MeV and 100-MeV for user. Proton beam transferred from the linac to the beam line using by dipole magnets and transferred proton beam focused and decreased beam loss and by quadrupole magnets.

  19. SPIN-ISOSPIN EXCITATIONS IN NUCLEI VIA (HE-3,T) REACTIONS AT 450 MEV

    NARCIS (Netherlands)

    FUJIWARA, M; AKIMUNE, H; DAITO, [No Value; EJIRI, H; FUJITA, Y; GREENFIELD, MB; HARAKEH, MN; HAZAMA, R; INOMATA, T; JANECKE, J; KUDOMI, N; KUME, K; NAKAYAMA, S; SHINMYO, K; TAMII, A; TANAKA, M; TOYOKAWA, H; YOSOI, M

    1994-01-01

    Spin-isospin excitations in nuclei havee been studied by means of the (He-3, t) reactions at 450 MeV. The Gamow-Teller (GT) resonances are found to be strongly excited. A fine structure of the giant Gamow Teller resonances in medium-heavy nuclei is observed with an energy resolution of 130 keV. The

  20. Optical model studies of 6Li elastic scattering at 156 MeV

    International Nuclear Information System (INIS)

    Differential cross sections for 6Li elastic scattering at 156 MeV from 12C, 40Ca 90Zr and 208Pb are presented. The sensitivity to various potential forms is established by using Saxon Woods, Saxon-Woods-squred, density independent and density dependent folded potentials. The extent to which the experimental data determine the potentials and related quantities is discussed. (orig.)