WorldWideScience

Sample records for 100-2600 mev protons

  1. Experimental and theoretical study of the yields of residual product nuclei produced in thin targets irradiated by 100-2600 MeV protons

    Titarenko, Y E; Karpikhin, E I

    2003-01-01

    The objective of the project is measurements and computer simulations of independent and cumulative yields of residual product nuclei in thin targets relevant as target materials and structure materials for hybrid accelerator-driven systems coupled to high-energy proton accelerators. The yields of residual product nuclei are of great importance when estimating such basic radiation-technology characteristics of hybrid facility targets as the total target activity, target 'poisoning', buildup of long-lived nuclides that, in turn, are to be transmuted, product nuclide (Po) alpha-activity, content of low-pressure evaporated nuclides (Hg), content of chemically-active nuclides that spoil drastically the corrosion resistance of the facility structure materials, etc. In view of the above, radioactive product nuclide yields from targets and structure materials were determined by an experiment using the ITEP U-10 proton accelerator in 51 irradiation runs for different thin targets: sup 1 sup 8 sup 2 sup , sup 1 sup 8 ...

  2. Experimental and Theoretical Study of the Residual Product Nuclide Yields in 100-2600 MeV Proton-Irradiated Thin Targets

    Titarenko, Y E; Karpikhin, E I; Zhivun, V M; Koldobsky, A B; Mulambetov, R D; Kvasova, S V; Fischenko, D V; Barashenkov, V S; Mashnik, S G; Prael, R E; Sierk, A J; Yasuda, H; Saitó, M; Titarenko, Yury E.; Batyaev, Vyacheslav F.; Karpikhin, Evgeny I.; Zhivun, Valery M.; Koldobsky, Aleksander B.; Mulambetov, Ruslan D.; Kvasova, Svetlana V.; Fischenko, Dmitry V.; Barashenkov, Vladilen S.; Mashnik, Stepan G.; Prael, Richard E.; Sierk, Arnold J.; Yasuda, Hideshi; Saito, Masaki

    2002-01-01

    The work is aimed at experimental determining and computer simulating the independent and cumulative yields of residual product nuclei in the target and structure materials of the transmutation facilities driven by high-current accelerators. The ITEP U-10 accelerator was used in 48 experiments to obtain more than 4000 values of the yields of radioactive residual product nuclei in 0.1-2.6 GeV proton-irradiated thin 182,183,184,186-W, nat-W, 56-Fe, 58-Ni, 93-Nb, 232-Th, nat-U, 99-Tc, 59-Co 63,65-Cu, nat-Hg, 208-Pb, and 27-Al targets. The results of verifying the LAHET, CEM95, CEM2k, CASCADE, CASCADE/INPE, YIELDX, HETC, INUCL, and other simulation codes are presented.

  3. Proton-proton bremsstrahlung at 280 MeV

    A proton-proton bremsstrahlung experiment has been carried out at TRIUMF using a 280-MeV polarized proton beam impinging on a liquid-hydrogen target. All three outgoing particles were detected: the higher-energy proton in a magnetic spectrometer, the lower-energy proton with plastic scintillators, and the photon in lead-glass Cherenkov detectors. The experiment shows the first unambiguous evidence for off-shell effects in the free nucleon-nucleon interaction, in that the analyzing powers disagree strongly with the predictions of the soft-photon approximation (which incorporates only on-shell information) but are consistent with the results of calculations using the Bonn and Paris potentials

  4. 14 MeV proton activation analysis

    A fast nuclear nondestructive method for protein analysis using the 14 MeV proton activation has been developed. The total nitrogen content was measured through the reaction: 14N (p,n) 14O, (Tsub(1/2)=71 s). The 14O activity was detected by means of its characteristic 2.312 MeV gamma-ray line with a NaI(Tl) detector. For a fast determination of a large number of samples a mechanized sistem reacting a rate of one sample per minute has been developed. The laboratory electronics comprises a multichannel analyser, a PDP computer and an electronic module comtroller. Comparison of the results obtained by the method described and the classical Kjeldal technique for samples of various cereal grains (soya bean seads, wheat, barley and corn) showed good correlation. A problem of the analysis of the whole protein region on corn and soya-bean seads, where this region is thicker (0,2 - 2 mm), is mentioned. In this case flour was proposed to be used to obtain a protein homogeneous sample and the irradiaton dose for a sample was about 33,000 Gy, mainly (99%) from protons (27 s x 100 nA x 14 MeV)

  5. Magnifying lens for 800 MeV proton radiography

    This article describes the design and performance of a magnifying magnetic-lens system designed, built, and commissioned at the Los Alamos National Laboratory (LANL) for 800 MeV flash proton radiography. The technique of flash proton radiography has been developed at LANL to study material properties under dynamic loading conditions through the analysis of time sequences of proton radiographs. The requirements of this growing experimental program have resulted in the need for improvements in spatial radiographic resolution. To meet these needs, a new magnetic lens system, consisting of four permanent magnet quadrupoles, has been developed. This new lens system was designed to reduce the second order chromatic aberrations, the dominant source of image blur in 800 MeV proton radiography, as well as magnifying the image to reduce the blur contribution from the detector and camera systems. The recently commissioned lens system performed as designed, providing nearly a factor of three improvement in radiographic resolution.

  6. Small angle proton-proton and proton-deuteron elastic scattering at 800 MeV

    Measurement of the energy of recoil particles was used to obtain the following data at 800 MeV incident proton energy: the differential cross section for elastic proton-proton scattering at laboratory angles ranging between 1.340 and 6.450, the analyzing power for elastic proton-proton scattering at laboratory angles ranging between 2.80 and 6.450, and the differential cross sections and analyzing powers for elastic proton-deuteron scattering at laboratory angles ranging between 3.970 and 13.10. The data were analyzed to obtain information about the hadronic parts of the proton-proton and proton-neutron forward scattering amplitudes. The ratio of the real to the imaginary parts of the forward p-p spin-independent amplitude was found to be 0.005 +- 0.04. The ratio of the summed moduli squared of the forward p-p double-spin-flip scattering amplitude to the modulus squared of the forward p-p spin-independent amplitude was found to be 0.16 +- 0.03. The real and the imaginary parts of the p-p spin-orbit scattering amplitude divided by sin theta were found to be 0.79 +- 0.05 fm and 0.18 +- 0.11 fm, respectively. Finally, the real and the imaginary parts of the p-n spin-orbit scattering amplitude divided by sin theta were found to be 0.79 +- 0.09 fm and -1.6 +- 0.03 fm, respectively. These values were compared with the results of recent phase-shift analyses and forward dispersion-relation calculation. 45 figures, 20 tables

  7. Shielding measurements for a 230 MeV proton beam

    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

  8. Proton polarimeter calibration between 82 and 217 MeV

    The proton analyzing power in carbon has been measured for energies of 82-217 MeV and proton scattering angles of 5-410. The measurements were carried out using polarized protons from the elastic scattering 1H(e→,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.

  9. Proton Polarimeter Calibration between 82 and 217 MeV

    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

    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.

  10. Proton polarimeter calibration between 82 and 217 MeV

    Glister, J. [Department of Astronomy and Physics, Saint Mary' s University, Halifax, Nova Scotia, B3H 3C3 (Canada); Dalhousie University, Halifax, Nova Scotia, B3H 3J5 (Canada)], E-mail: jglister@jlab.org; Ron, G. [Tel Aviv University, Tel Aviv 69978 (Israel); Lee, B. [Seoul National University, Seoul 151-747 (Korea, Republic of); Beck, A. [NRCN, P.O. Box 9001, Beer-Sheva 84190 (Israel); Brash, E. [Christopher Newport University, Newport News, VA 23606 (United States); Camsonne, A. [Thomas Jefferson National Accelerator Facility, Newport News, VA 23606 (United States); Choi, S. [Seoul National University, Seoul 151-747 (Korea, Republic of); Dumas, J. [Rutgers, State University of New Jersey, Piscataway, NJ 08855 (United States); Feuerbach, R. [Thomas Jefferson National Accelerator Facility, Newport News, VA 23606 (United States); Gilman, R. [Thomas Jefferson National Accelerator Facility, Newport News, VA 23606 (United States); Rutgers, State University of New Jersey, Piscataway, NJ 08855 (United States); Higinbotham, D.W. [Thomas Jefferson National Accelerator Facility, Newport News, VA 23606 (United States); Jiang, X. [Rutgers, State University of New Jersey, Piscataway, NJ 08855 (United States); Jones, M.K. [Thomas Jefferson National Accelerator Facility, Newport News, VA 23606 (United States); May-Tal Beck, S. [NRCN, P.O. Box 9001, Beer-Sheva 84190 (Israel); McCullough, E. [Department of Astronomy and Physics, Saint Mary' s University, Halifax, Nova Scotia, B3H 3C3 (Canada); Paolone, M. [University of South Carolina, Columbia, SC 29208 (United States); Piasetzky, E. [Tel Aviv University, Tel Aviv 69978 (Israel); Roche, J. [Ohio University, Athens, OH 45701 (United States); Rousseau, Y. [Rutgers, The State University of New Jersey, Piscataway, NJ 08855 (United States); Sarty, A.J. [Department of Astronomy and Physics, Saint Mary' s University, Halifax, Nova Scotia, B3H 3C3 (Canada)] (and others)

    2009-07-21

    The proton analyzing power in carbon has been measured for energies of 82-217 MeV and proton scattering angles of 5-41{sup 0}. The measurements were carried out using polarized protons from the elastic scattering {sup 1}H(e{sup {yields}},p{sup {yields}}) 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. The JHP 200-MeV proton linear accelerator

    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)

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

    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.

  13. Dose determination of 600 MeV proton irradiated specimens

    The calculation method for the experimental determination of the atomic production cross section from the γ activity measurements are presented. This method is used for the determination of some isotope production cross sections for 600 MeV proton irradition in MANET steel, copper, tungsten, gold and titanium. The results are compared with some calculation. These values are used to determine the dose of specimens irradiated in the PIREX II facility. The results are discussed in terms of the irradiation parameters. A guide for the use of the production cross section determined in the dosimetry experiment are given. (author) tabs., refs

  14. Proton target polarization measured with a polarized neutron beam at 477 MeV

    The polarization of a proton target is determined with elastic neutron-proton scattering at 477 MeV. The results agree well with the nuclear magnetic resonance measurements at the error level of 4%. (orig.)

  15. Proton scattering from 4He at 500 MeV

    We calculate the optical potential for the scattering of 500 MeV protons from 4He using first-order Brueckner theory and compare with experimental data. The real part of the calculated potential has a 'wine bottle' shape in agreement with recent phenomenological analyses. The agreement with experiment is good for scattering angles less than 700. We also analyse the same data using the Dirac equation. The fits to the data over a wide angular range are very good. We find ambiguities in the relativistic potentials as several sets of parameters fit the data almost equally well. In all cases the real vector and scalar potentials exhibit central minima. The 'Schroedinger equivalent' potentials again have 'wine bottle' shapes. We discuss the similarities between the two approaches. (orig.)

  16. Multiple Coulomb scattering of 160 MeV protons

    Gottschalk, B.; Koehler, A. M.; Schneider, R. J.; Sisterson, J. M.; Wagner, M. S.

    1993-06-01

    We have measured multiple Coulomb scattering of 158.6 MeV protons in fourteen materials from beryllium to uranium including brass and several plastics. Targets ranged from thin (negligible energy loss) to very thick (greater than the mean proton range). The angular distribution was measured by means of a single diode dosimeter scanned typically over two decades of dose falloff. Each data set was fitted with a Molière scattering distribution (using Bethe's tables) to extract a characteristic angle θ M as well as a Gaussian distribution to extract a characteristic angle θ 0. As expected in the small angle region, the Gaussian fits about as well as the Molière shape. The θM values were compared with Molière's predicted value ( {χ cB}/{2}) including Fano's correction for scattering by atomic electrons and using Molière's formalism to account for energy loss and/or compound targets or mixtures. The distribution of the deviation from theory for 115 independent measurements is approximately normal, with a mean value - 0.5 ± 0.4% and an rms spread of 5%. The θ 0 values were compared with Highland's formula and with an "improved Highland" formula of Lynch and Dahl, using our own generalization to thick targets. The overall accuracy of Highland's formula is slightly worse than that of Molière theory. The distribution of the deviation from theory for 115 independent measurements is normal, with a mean value - 2.6 ± 0.5% and an rms spread of 6%. The Lynch formula gives nearly the same average statistics though details of the fit are different. Some data were taken for very thick targets (thickness greater than 97% of the mean proton range) where only a fraction of the incident protons emerge. Here the characteristic angle appears to level off or even to fall slightly with target thickness perhaps due to the filtering out of large-angle protons. These measurements are presented but were excluded from the comparison with theory. We have reviewed six other published

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

    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)

  18. Quasifree knockout of proton pairs from carbon with 640 MeV protons

    The direct nuclear reaction C(p,3p) at 640 MeV has been investigated in an exclusive type of experiment using scintillation counter technique. The measuring conditions have been selected according to the kinematics of quasi-free two-nucleon knockout at large momentum transfer. A phenomenological model is discussed, which is capable of describing qualitatively the dependence of the differential cross section on the opening angle of the forward emitted proton pair as well as on the energy of backward going protons. (author)

  19. Si exfoliation by MeV proton implantation

    Proton implantation in silicon and subsequent annealing are widely used in the Smart Cut™ technology to transfer thin layers from a substrate to another. The low implantation energy range involved in this process is usually from a few ten to a few hundred of keV, which enables the separation of up to 2 μm thick layers. New applications in the fields of 3D integration and photovoltaic wafer manufacturing raise the demand for extending this technology to higher energy in order to separate thicker layer from a substrate. In this work, we propose to investigate the effect of proton implantation in single crystalline silicon in the 1–3 MeV range which corresponds to a 15–100 μm range for the hydrogen maximum concentration depth. We show that despites a considerably lower hydrogen concentration at Rp, the layer separation is obtained with fluence close to the minimum fluence required for low energy implantation. It appears that the fracture propagation in Si and the resulting surface morphology is affected by the substrate orientation. Defects evolution is investigated with Fourier Transform Infrared Spectroscopy. The two orientations reveal similar type of defects but their evolution under annealing appears to be different.

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

    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.)

  1. Neutron production from 200-500 MeV proton interaction with spacecraft materials

    We report on detailed energy spectra of neutron production >14 MeV from collisions of 200-500 MeV protons with combinations of aluminium, graphite and polyethylene. Comparisons of normalised neutron spectra are made with respect to incident proton energy, angle of neutron production and material. In general, carbon (graphite) or polyethylene (by itself or in combination with aluminium) reduce secondary neutron production >14 MeV relative to the production from interactions in aluminium. (authors)

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

    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.

  3. Flare vs. Shock Acceleration of >100 MeV Protons in Large Solar Particle Events

    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.

  4. Microdosimetric distribution of protons, Ep=19-65 MeV, measured with a low pressure proportional counter

    Microdosimetric measurements of 19, 32, 43, 55, and 65 MeV protons were carried out with the A-150-walled low pressure proportional counter. The spectra are deconvoluted into three components, which are energy loss by directly incident protons, secondary electrons, and scattered protons and heavy charged particles (including protons) produced by proton nuclear reactions with the TE wall. Dose-mean lineal energies of protons are large as usual, because larger lineal energies by proton reaction events are affected. (author)

  5. The design study for a 500 MeV proton synchrotron with CSNS linac as an injector

    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.

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

    Using TRIUMF proton beams of 400- to 500-MeV bombarding carbon and copper targets we have measured positive pion production cross sections for pion energies 20 to 100 MeV and pion angles 60 to 1500. The pions were stopped in a range telescope in which time-of-flight, energy loss, and the detection of the pion decay were used for particle identification

  7. Radiation shielding for 250 MeV protons

    This paper is targetted at personnel who have the responsibility of designing the radiation shielding against neutron fluences created when protons interact with matter. Shielding of walls and roofs are discussed, as well as neutron dose leakage through labyrinths. Experimental data on neutron flux attenuation are considered, as well as some calculations using the intranuclear cascade calculations and parameterizations

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

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

    2013-01-01

    The design of a low-power prototype of neutron amplifier recently proposed within the INFN-E project indicated the need for more accurate called for detailed data on the neutron yield produced by a proton beam with energy of about 70 MeV impinging on a thick Beryllium target. Such measurement was performed at the LNS superconducting cyclotron, covering a wide angular range from 0 to 150 degrees and a complete neutron energy interval from thermal to beam energy. Neutrons with energy above 0.5 MeV were measured by liquid scintillators exploiting their Time of Flight to determine the kinetic energy. For lower energy neutrons, down to thermal energy, a $^3$He detector was used. The obtained data are in good agreement with previous measurements at 0 degree with 66 MeV proton beam, covering neutron energies >10 MeV, as well as with measurements at few selected angles with protons of 46, 55 and 113 MeV energy. The present results extend the neutron yield data in the 60-70 MeV beam energy range. A comparison of measu...

  9. Measurement of neutron yield by 62 MeV proton beam on a thick beryllium target

    The design of a low-power prototype of neutron amplifier recently proposed within the INFN-E project indicated the need for more accurate data on the neutron yield produced by a proton beam with energy of about 70 MeV impinging on a thick beryllium target. Such measurement was performed at the LNS superconducting cyclotron, covering a wide angular range from 0° to 150° and a complete neutron energy interval from thermal to beam energy. Neutrons with energy above 0.5 MeV were measured by liquid scintillators exploiting their time of flight to determine the kinetic energy. For lower energy neutrons, down to thermal energy, a 3He detector was used. The obtained data are in good agreement with previous measurements at 0° using 66 MeV proton beam, covering neutron energies >10MeV, as well as with measurements at few selected angles using protons of 46, 55 and 113 MeV energy. The present results extend the neutron yield data in the 60–70 MeV beam energy range. A comparison of measured yields to MCNP, FLUKA and Geant4 Monte Carlo simulations was performed

  10. Measurement of neutron yield by 62 MeV proton beam on a thick beryllium target

    Osipenko, M., E-mail: osipenko@ge.infn.it [INFN, sezione di Genova, 16146 Genova (Italy); Ripani, M. [INFN, sezione di Genova, 16146 Genova (Italy); Alba, R. [INFN, Laboratori Nazionali del Sud, 95123 Catania (Italy); Ricco, G. [INFN, sezione di Genova, 16146 Genova (Italy); Schillaci, M. [INFN, Laboratori Nazionali del Sud, 95123 Catania (Italy); Barbagallo, M. [INFN, sezione di Bari, 70126 Bari (Italy); Boccaccio, P. [INFN, Laboratori Nazionali di Legnaro, 35020 Legnaro (Italy); Celentano, A. [Dipartimento di Fisica dell' Università di Genova, 16146 Genova (Italy); Colonna, N. [INFN, sezione di Bari, 70126 Bari (Italy); Cosentino, L.; Del Zoppo, A.; Di Pietro, A. [INFN, Laboratori Nazionali del Sud, 95123 Catania (Italy); Esposito, J. [INFN, Laboratori Nazionali di Legnaro, 35020 Legnaro (Italy); Figuera, P.; Finocchiaro, P. [INFN, Laboratori Nazionali del Sud, 95123 Catania (Italy); Kostyukov, A. [Moscow State University, Moscow 119992 (Russian Federation); Maiolino, C.; Santonocito, D.; Scuderi, V. [INFN, Laboratori Nazionali del Sud, 95123 Catania (Italy); Viberti, C.M. [Dipartimento di Fisica dell' Università di Genova, 16146 Genova (Italy)

    2013-09-21

    The design of a low-power prototype of neutron amplifier recently proposed within the INFN-E project indicated the need for more accurate data on the neutron yield produced by a proton beam with energy of about 70 MeV impinging on a thick beryllium target. Such measurement was performed at the LNS superconducting cyclotron, covering a wide angular range from 0° to 150° and a complete neutron energy interval from thermal to beam energy. Neutrons with energy above 0.5 MeV were measured by liquid scintillators exploiting their time of flight to determine the kinetic energy. For lower energy neutrons, down to thermal energy, a {sup 3}He detector was used. The obtained data are in good agreement with previous measurements at 0° using 66 MeV proton beam, covering neutron energies >10MeV, as well as with measurements at few selected angles using protons of 46, 55 and 113 MeV energy. The present results extend the neutron yield data in the 60–70 MeV beam energy range. A comparison of measured yields to MCNP, FLUKA and Geant4 Monte Carlo simulations was performed.

  11. Radiation hardness of a single crystal CVD diamond detector for MeV energy protons

    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.

  12. 1000 MeV Proton beam therapy facility at Petersburg Nuclear Physics Institute Synchrocyclotron

    Abrosimov, N. K.; Gavrikov, Yu A.; Ivanov, E. M.; Karlin, D. L.; Khanzadeev, A. V.; Yalynych, N. N.; Riabov, G. A.; Seliverstov, D. M.; Vinogradov, V. M.

    2006-05-01

    Since 1975 proton beam of PNPI synchrocyclotron with fixed energy of 1000 MeV is used for the stereotaxic proton therapy of different head brain diseases. 1300 patients have been treated during this time. The advantage of high energy beam (1000 MeV) is low scattering of protons in the irradiated tissue. This factor allows to form the dose field with high edge gradients (20%/mm) that is especially important for the irradiation of the intra-cranium targets placed in immediate proximity to the life critical parts of the brain. Fixation of the 6 0mm diameter proton beam at the isodose centre with accuracy of ±1.0 mm, two-dimensional rotation technique of the irradiation provide a very high ratio of the dose in the irradiation zone to the dose at the object's surface equal to 200:1. The absorbed doses are: 120-150 Gy for normal hypophysis, 100-120 Gy for pituitary adenomas and 40-70 Gy for arterio-venous malformation at the rate of absorbed dose up to 50 Gy/min. In the paper the dynamics and the efficiency of 1000 MeV proton therapy treatment of the brain deceases are given. At present time the feasibility study is in progress with the goal to create a proton therapy on Bragg peak by means of the moderation of 1000 MeV proton beam in the absorber down to 200 MeV, energy required for radiotherapy of deep seated tumors.

  13. 1000 MeV Proton beam therapy facility at Petersburg Nuclear Physics Institute Synchrocyclotron

    Abrosimov, N K [Petersburg Nuclear Physics Institute, 188300 Gatchina (Russian Federation); Gavrikov, Yu A [Petersburg Nuclear Physics Institute, 188300 Gatchina (Russian Federation); Ivanov, E M [Petersburg Nuclear Physics Institute, 188300 Gatchina (Russian Federation); Karlin, D L [Central Research Institute of Roentgenology and Radiology, 197758, St.Petersburg (Russian Federation); Khanzadeev, A V [Petersburg Nuclear Physics Institute, 188300 Gatchina (Russian Federation); Yalynych, N N [Central Research Institute of Roentgenology and Radiology, 197758, St. Petersburg (Russian Federation); Riabov, G A [Petersburg Nuclear Physics Institute, 188300 Gatchina (Russian Federation); Seliverstov, D M [Petersburg Nuclear Physics Institute, 188300 Gatchina (Russian Federation); Vinogradov, V M [Central Research Institute of Roentgenology and Radiology, 197758, St.Petersburg (Russian Federation)

    2006-05-15

    Since 1975 proton beam of PNPI synchrocyclotron with fixed energy of 1000 MeV is used for the stereotaxic proton therapy of different head brain diseases. 1300 patients have been treated during this time. The advantage of high energy beam (1000 MeV) is low scattering of protons in the irradiated tissue. This factor allows to form the dose field with high edge gradients (20%/mm) that is especially important for the irradiation of the intra-cranium targets placed in immediate proximity to the life critical parts of the brain. Fixation of the 6 0mm diameter proton beam at the isodose centre with accuracy of {+-}1.0 mm, two-dimensional rotation technique of the irradiation provide a very high ratio of the dose in the irradiation zone to the dose at the object's surface equal to 200:1. The absorbed doses are: 120-150 Gy for normal hypophysis, 100-120 Gy for pituitary adenomas and 40-70 Gy for arterio-venous malformation at the rate of absorbed dose up to 50 Gy/min. In the paper the dynamics and the efficiency of 1000 MeV proton therapy treatment of the brain deceases are given. At present time the feasibility study is in progress with the goal to create a proton therapy on Bragg peak by means of the moderation of 1000 MeV proton beam in the absorber down to 200 MeV, energy required for radiotherapy of deep seated tumors.

  14. 160 MeV laser-accelerated protons from CH2 nano-targets for proton cancer therapy

    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...

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

    King, N S P; Adams, K; Alrick, K R; Amann, J F; Balzar, S; Barnes, P D J; Crow, M L; Cushing, S B; Eddleman, J C; Fife, T T; Flores, P; Fujino, D; Gallegos, R A; Gray, N T; Hartouni, E P; Hogan, G E; Holmes, V H; Jaramillo, S A; Knudsson, J N; London, R K; Lopez, R R; McDonald, T E; McClelland, J B; Merrill, F E; Morley, K B; Morris, C L; Naivar, F J; Parker, E L; Park, H S; Pazuchanics, P D; Pillai, C; Riedel, C M; Sarracino, J S; Shelley, F E J; Stacy, H L; Takala, B E; Thompson, R; Tucker, H E; Yates, G J; Ziock, H J; Zumbro, J D

    1999-01-01

    The capability has successfully been developed at the Los Alamos Nuclear Science Center (LANSCE) to utilize a spatially and temporally prepared 800 MeV proton beam to produce proton radiographs. A series of proton bursts are transmitted through a dynamic object and transported, via a unique magnetic lens system, to an image plane. The magnetic lens system permits correcting for the effects of multiple coulomb scattering which would otherwise completely blur the spatially transmitted information at the image plane. The proton radiographs are recorded either on a time integrating film plate or with a recently developed multi-frame electronic imaging camera system. The latter technique permits obtaining a time dependent series of proton radiographs with time intervals (modulo 358 ns) up to many microseconds and variable time intervals between images. One electronically shuttered, intensified, CCD camera is required per image. These cameras can detect single protons interacting with a scintillating fiber optic ar...

  16. Dilepton and double-photon production in proton-proton scattering at 190 MeV

    Caplar, R.; Bacelar, J.C.S; Castelijns, R.J.J.; Ermisch, K.; Gasparic, I.; Harakeh, M.N.; Kalantar-Nayestanaki, N.; Kis, M.; Löhner, H.; Mahjour Shafiei, M.

    2004-01-01

    The first high-statistics measurement of dilepton and double-photon yields in proton-proton scattering below the pion threshold has been performed. The data obtained allow a detailed study of off-shell effects in the proton-proton interaction.

  17. 72 MeV proton cyclotron for boron neutron capture therapy in Slovakia

    A cyclotron complex named CYLAB is being built at the Slovak Institute of Metrology. The main equipment, a cyclotron producing 72 MeV protons and light and heavy ions up to 129Xe20+, will be manufactured by the Joint Institute for Nuclear Research in Dubna. Medicine, physics, and metrology will be the main CYLAB application fields. The 66 MeV p-Be reaction will be used for fast neutron therapy, the spallation reactions of 72 MeV p on a tungsten target will be used in neutron capture therapy, and 72 MeV, 100 nA protons will be used in eye therapy. The medical applications of CYLAB are described with emphasis on boron neutron capture therapy (BNCT) and the gantry built for it, based on the 72 MeV/50 μA proton cyclotron. Theoretical calculations showed that in comparison with the equipment with a conventional configuration of moderators, reflectors, filters and shielding, significant improvements in epithermal neutron production will emerge, leading to a higher RBE dose rate at a 7 cm depth of the brain. (P.A.)

  18. Fixed fluorescent images of an 80 MeV proton pencil beam

    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

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

    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

  20. PHOTONS IN THE PROTON-INDUCED REACTION WITH IN AT E(P)=50-MEV

    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

  1. Defect microstructure in copper alloys irradiated with 750 MeV protons

    Zinkle, S.J.; Horsewell, A.; Singh, B.N.; Sommer, W.F.

    1994-01-01

    Transmission electron microscopy (TEM) disks of pure copper and solid solution copper alloys containing 5 at% of Al, Mn, or Ni were irradiated with 750 MeV protons to damage levels between 0.4 and 2 displacements per atom (dpa) at irradiation temperatures between 60 and 200 degrees C. The defect...

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

    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).

  3. Preequilibrium proton emission in violent heavy-ion collisions around 30 MeV per nucleon

    Protons emitted in coincidence with heavy residues resulting from incomplete fusion processes have been measured, for the reaction 27 MeV per nucleon 40Ar + natAg. From the proton velocity spectra, an anisotropic component was extracted, which shows a broad angular distribution, and a mean velocity larger than the beam velocity. Nevertheless, the average velocity along the beam axis is very close to the beam velocity, in agreement with the standard assumption usually made in order to derive the linear momentum transferred to the target, but the mean energy carried away by these protons is larger than the value commonly assumed

  4. Radiation damage of polycrystalline diamond exposed to 62 MeV protons

    Alemanno, E.; Caricato, A.P. [INFN - Sezione di Lecce (Italy); Università del Salento (Italy); Chiodini, G., E-mail: gabriele.chiodini@le.infn.it [INFN - Sezione di Lecce (Italy); Corvaglia, A. [INFN - Sezione di Lecce (Italy); Cirrone, G.A.P.; Cuttone, G. [INFN - Laboratori Nazionali del Sud (Italy); Dinardo, M.; Dangelo, P. [INFN - Sezione di Milano-Bicocca (Italy); De Napoli, M. [INFN - Sezione di Catania (Italy); Fiore, G. [INFN - Sezione di Lecce (Italy); Kwan, S. [FNAL, Batavia, IL (United States); Malvezzi, S. [INFN - Sezione di Milano-Bicocca (Italy); Leone, A. [INFN - Sezione di Lecce (Italy); Martino, M. [INFN - Sezione di Lecce (Italy); Università del Salento (Italy); Menasce, D.; Moroni, L.; Pedrini, D. [INFN - Sezione di Milano-Bicocca (Italy); Perrino, R. [INFN - Sezione di Lecce (Italy); Randazzo, N. [INFN - Sezione di Catania (Italy); Pinto, C. [INFN - Sezione di Lecce (Italy); Università del Salento (Italy); and others

    2013-12-01

    We irradiated two diamond detectors with 62 MeV energy proton beam up to an integrated fluence of about 2×10{sup 15} protons/cm{sup 2} at INFN-LNS in Catania (Italy). The detectors were made of two high purity poly-crystal diamond sensors. The electric contacts of the two diamond sensors were from different sources and made with different techniques: a proprietary DLC/Pt/Au electric contact and our own novel UV Laser technique. We collected 120 GeV and 62 MeV proton beam data, before and after irradiation, respectively, to extract the radiation damage constant of one poly-crystal diamond sensor by using single crystal diamond detector response as reference.

  5. The design of a proton recoil telescope for 14 MeV neutron spectrometry

    Hawkes, N P; Croft, S; Jarvis, O N; Sherwood, A C

    2002-01-01

    As part of the design effort for a 14 MeV neutron spectrometer for the Joint European Torus (JET), computer codes were developed to calculate the response of a proton recoil telescope comprising a proton radiator film mounted in front of a proton detector. The codes were used to optimise the geometrical configuration in terms of efficiency and resolution, bearing in mind the constraints imposed by the proposed application as a JET neutron diagnostic for the Deuterium-Tritium phase. A prototype instrument was built according to the optimised design, and tested with monoenergetic 14 MeV neutrons from the Harwell 500 keV Van de Graaff accelerator. The measured energy resolution and absolute efficiency were found to be in acceptable agreement with the calculations. Based on this work, a multi-radiator production version of the spectrometer has now been constructed and successfully deployed at JET.

  6. U, Th and Bi fission induced by protons of 600 MeV

    The measurements of U, Bi an Th fission cross sections induced by protons of 600 MeV were carried out, using nuclear emulsion techniques. The targets were prepared from KO Ilford type emulsion using solutions of U, Bi and Th complexes for its loading. The proton beam of 586 +- 5 MeV and integrated flux of 1,6 (+- 4,890)X1011 protons from CERN Synchro-Cyclotron was used for irradiating nuclear emulsions. The integrated flux was carried from aluminium desintegration curves by Al22 (p, 3pn) Na24 reaction. The fission events, were observed using Leitz microscopy and the statistical error of 10% were calculated. (M.C.K.)

  7. Analysing powers and spin correlations in deuteron-proton charge exchange at 726 MeV

    Dymov, S; Bagdasarian, Z; Barsov, S; Carbonell, J; Chiladze, D; Engels, R; Gebel, R; Grigoryev, K; Hartmann, M; Kacharava, A; Khoukaz, A; Komarov, V; Kulessa, P; Kulikov, A; Kurbatov, V; Lomidze, N; Lorentz, B; Macharashvili, G; Mchedlishvili, D; Merzliakov, S; Mielke, M; Mikirtychyants, M; Mikirtychyants, S; Nioradze, M; Ohm, H; Prasuhn, D; Rathmann, F; Serdyuk, V; Seyfarth, H; Shmakova, V; Ströher, H; Tabidze, M; Trusov, S; Tsirkov, D; Uzikov, Yu; Valdau, Yu; Weidemann, C; Wilkin, C

    2015-01-01

    The charge exchange of vector polarised deuterons on a polarised hydrogen target has been studied in a high statistics experiment at the COSY-ANKE facility at a deuteron beam energy of Td = 726 MeV. By selecting two fast protons at low relative energy E_{pp}, the measured analysing powers and spin correlations are sensitive to interference terms between specific neutron-proton charge-exchange amplitudes at a neutron kinetic energy of Tn ~ 1/2 Td =363 MeV. An impulse approximation calculation, which takes into account corrections due to the angular distribution in the diproton, describes reasonably the dependence of the data on both E_{pp} and the momentum transfer. This lends broad support to the current neutron-proton partial-wave solution that was used in the estimation.

  8. Filamentation control and collimation of laser accelerated MeV protons

    Ramakrishna, B.; Tayyab, M.; Bagchi, S.; Mandal, T.; Upadhyay, A.; Weng, S. M.; Murakami, M.; Cowan, T. E.; Chakera, J. A.; Naik, P. A.; Gupta, P. D.

    2015-12-01

    We demonstrate experimentally that the proton beam filamentation in dense plasma can be controlled in multi-layered (Al-CH-Al) sandwich targets. We observe up to three-fold reduction in the MeV proton beam divergence (~12°) from these targets as a result of decrease in filamentary structures in the proton beam profile. Strong self-generated resistive magnetic fields in targets with a high-Z transport layer are mainly responsible for this observed effect. Enhancement in the proton flux and energy is also observed from these targets. Supported by a matching 2D particle-in-cell (PIC) simulation and theoretical considerations, we suggest that these targets can be very effectively implemented to collimate proton beams useful for ion oncology applications or advanced fast igniter approach of inertial confinement fusion (ICF).

  9. Radiation effects on MOS and bipolar devices by 8 MeV protons, 60 MeV Br ions and 1 MeV electrons

    The radiation effects of the metal-oxide-semiconductor (MOS) and the bipolar devices are characterised using 8 MeV protons, 60 MeV Br ions and 1 MeV electrons. Key parameters are measured in-situ and compared for the devices. The ionising and nonionising energy losses of incident particles are calculated using the Geant4 and the stopping and range of ions in matter code. The results of the experiment and energy loss calculation for different particles show that different incident particles may give different contributions to MOS and bipolar devices. The irradiation particles, which cause a larger displacement dose within the same chip depth of bipolar devices at a given total dose, would generate more severe damage to the voltage parameters of the bipolar devices. On the contrary, the irradiation particles, which cause larger ionising damage in the gate oxide, would generate more severe damage to MOS devices. In this investigation, we attempt to analyse the sensitivity to radiation damage of the different parameter of the MOS and bipolar devices by comparing the irradiation experimental data and the calculated results using Geant4 and SRIM code. (condensed matter: structure, thermal and mechanical properties)

  10. RF control system for the KEK 40 MeV proton linac

    The KEK 40 MeV proton linac comprises a pre-buncher, the first tank (750 keV to 20 MeV), the second tank(20 MeV to 40 MeV) and a de-buncher. As routine operation, negative hydrogen ion (H-) beams of 5 mA with a beam pulse duration of about 80 μs are accelerated and transported to the Booster Synchrotron. In April 1992 negative deuterium ion (D-) beams of about 2.5 mA were accelerated under the 4 π-mode operation. At present, in order to accelerate H- or D- beams, the accelerating field strength in each of the four cavities and the phase differences between the cavities are manually tuned by watching many beam monitors installed on the transport lines. Operation of the KEK 40 MeV proton linac has therefore not been very easy. An RF control system with a feedback (ALC and PLL) system has thus been developed in order to stabilize the accelerating RF fields and to deal with the acceleration mode, which would be used to select parameters of the accelerating field for the acceleration of various particle beams. This report describes the RF control system under development and the tested results. (Author) 5 refs., 6 figs

  11. Epics Support IOC for Monitoring Waveform Data of PEFP 100-MeV Proton LINAC

    Song, Young Gi; Kwon, Hyeok Jung; Jang, Ji Ho; Cho, Yong Sub [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2012-05-15

    The Proton Engineering Frontier Project (PEFP) is constructing a 100-MeV proton Linear Accelerator (Linac), consisting of a 50-keV proton injector, Low Energy Beam Transport (LEBT), a 3-MeV Radio Frequency Quadrupole (RFQ), a 20-MeV Drift Tube Linac (DTL), 100-MeV DTL, and beam lines. For PEFP commissioning and operation, remote control and monitoring system of the RF and beam current signals is essential for operators. To monitor and control the RF and beam signals from subsystems of the 100-MeV proton accelerator, VME PMC ADC boards and oscilloscopes are equipped. The measured signals are transmitted and displayed on operator consoles in a control room. The VME baseboard and oscilloscope must support Ethernet based TCP/IP protocol for communication interface and the monitoring systems must be integrated with control systems for PEFP project. To achieve these goals and minimize the development period, the EPICS middleware and extension tools are adopted. The EPICS IOC has been tested to control and monitor the subsystems of PEFP. The EPICS IOC supports to create various database records to access I/O data and setting parameters. One of EPICS database records is the waveform record to acquire array signals of the device and the waveform record can support the remote control and monitoring of control system by using various devices including oscilloscope instrumentations, VME ADC boards, PXI, cPCI, etc. Operators can observe the waveform using some graphic viewers. The implementation of EPICS waveform support for the PEFP is described in this paper

  12. Epics Support IOC for Monitoring Waveform Data of PEFP 100-MeV Proton LINAC

    The Proton Engineering Frontier Project (PEFP) is constructing a 100-MeV proton Linear Accelerator (Linac), consisting of a 50-keV proton injector, Low Energy Beam Transport (LEBT), a 3-MeV Radio Frequency Quadrupole (RFQ), a 20-MeV Drift Tube Linac (DTL), 100-MeV DTL, and beam lines. For PEFP commissioning and operation, remote control and monitoring system of the RF and beam current signals is essential for operators. To monitor and control the RF and beam signals from subsystems of the 100-MeV proton accelerator, VME PMC ADC boards and oscilloscopes are equipped. The measured signals are transmitted and displayed on operator consoles in a control room. The VME baseboard and oscilloscope must support Ethernet based TCP/IP protocol for communication interface and the monitoring systems must be integrated with control systems for PEFP project. To achieve these goals and minimize the development period, the EPICS middleware and extension tools are adopted. The EPICS IOC has been tested to control and monitor the subsystems of PEFP. The EPICS IOC supports to create various database records to access I/O data and setting parameters. One of EPICS database records is the waveform record to acquire array signals of the device and the waveform record can support the remote control and monitoring of control system by using various devices including oscilloscope instrumentations, VME ADC boards, PXI, cPCI, etc. Operators can observe the waveform using some graphic viewers. The implementation of EPICS waveform support for the PEFP is described in this paper

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

    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)

  14. New frontier of laser particle acceleration: driving protons to 80 MeV by radiation pressure

    Kim, I Jong; Kim, Chul Min; Kim, Hyung Taek; Lee, Chang-Lyoul; Choi, Il Woo; Singhal, Himanshu; Sung, Jae Hee; Lee, Seong Ku; Lee, Hwang Woon; Nickles, Peter V; Jeong, Tae Moon; Nam, Chang Hee

    2014-01-01

    The radiation pressure acceleration (RPA) of charged particles has been considered a challenging task in laser particle acceleration. Laser-driven proton/ion acceleration has attracted considerable interests due to its underlying physics and potential for applications such as high-energy density physics, ultrafast radiography, and cancer therapy. Among critical issues to overcome the biggest challenge is to produce energetic protons using an efficient acceleration mechanism. The proton acceleration by radiation pressure is considerably more efficient than the conventional target normal sheath acceleration driven by expanding hot electrons. Here we report the generation of 80-MeV proton beams achieved by applying 30-fs circularly polarized laser pulses with an intensity of 6.1 x 1020 W/cm2 to ultrathin targets. The radiation pressure acceleration was confirmed from the obtained optimal target thickness, quadratic energy scaling, polarization dependence, and 3D-PIC simulations. We expect this fast energy scalin...

  15. Effects of 1-MeV proton irradiation in Hg-based cuprate thin films

    We have studied the effects of 1-Mev proton irradiation on both superconducting properties and normal state resistivity of high-quality HgBa2CaCu2O6+δ (Hg-1212) and HgBa2Ca2Cu3O8+δ (Hg-1223) thin films. At low proton doses, we observed a linear decrease of the superconducting transition temperature Tc and a linear increase of the extrapolated residual resistivity as proton dose is increased. This is consistent with observations of other high-Tc superconductors while a lower dose threshold for suppressing the superconductivity is found in Hg-1212 and Hg-1223 films. To explain the linear dose dependence of Tc, we propose a model based on the proximity effect. An enhancement of up to 90% in the critical current density at low fields has also been observed in these films at low proton fluences that do not significantly degrade Tc. copyright 1997 The American Physical Society

  16. 520 MeV proton irradiation effects on GaAs/Ge space solar cells

    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

  17. Elastic scattering of polarized protons on deuterium at 800 MeV

    A specific set of spin transfer coefficients has been measured for proton-deuteron elastic scattering at 800 MeV using an unpolarized liquid deuterium target. The experiment was done using the High Resolution Spectrometer (HRS) at the Los Alamos Meson Physics Facility (LAMPF) with a polarized proton beam. The scattered proton spin direction was determined using the Focal Plane Polarimeter (FPP) of the HRS, which employs a carbon analyzer. Some of the spin dependent parameters measured in this experiment are of considerable interest because they provide selective information about the nucleon-nucleon (NN) amplitude. Since the deuteron is the simplest bound nucleus, pd elastic scattering is particularly well suited for testing multiple scattering theories. These measurements will also be used to eventually determine the full pd collision matrix, which contains all possible information about the scattering process. In addition, the experimental setup is described for a polarized proton-polarized deuterium target spin transfer experiment also done at the HRS at 800 MeV incident proton energy. 71 references

  18. Elastic scattering of polarized protons on deuterium at 800 MeV

    Weston, G.S.

    1984-07-01

    A specific set of spin transfer coefficients has been measured for proton-deuteron elastic scattering at 800 MeV using an unpolarized liquid deuterium target. The experiment was done using the High Resolution Spectrometer (HRS) at the Los Alamos Meson Physics Facility (LAMPF) with a polarized proton beam. The scattered proton spin direction was determined using the Focal Plane Polarimeter (FPP) of the HRS, which employs a carbon analyzer. Some of the spin dependent parameters measured in this experiment are of considerable interest because they provide selective information about the nucleon-nucleon (NN) amplitude. Since the deuteron is the simplest bound nucleus, pd elastic scattering is particularly well suited for testing multiple scattering theories. These measurements will also be used to eventually determine the full pd collision matrix, which contains all possible information about the scattering process. In addition, the experimental setup is described for a polarized proton-polarized deuterium target spin transfer experiment also done at the HRS at 800 MeV incident proton energy. 71 references.

  19. Dosimetric characterization of CVD diamonds irradiated with 62 MeV proton beams

    Diamond is potentially a very suitable material for use as on-line radiation dosimeter. Recent advances in the synthesis of polycrystalline diamond by chemical vapor deposition (CVD) techniques have produced material with electronic properties suitable for dosimetry applications. In this work the possibility to use a segmented commercial CVD detector in the dosimetry of proton beams has been investigated. The response as function of dose, dose rate, the priming and the rise time have been investigated thoroughly. This study shows the suitability of CVD diamond for dosimetry of clinical 62 MeV proton beams

  20. Relative biological effectiveness for protons of energies up to 31 MeV

    The relative biological effectiveness (RBE) was determined for proton beams of 31,12, and 8 MeV produced at the Milano University Cyclotron. Survival curves for human cells grown in monolayer at different proton energies and for γ rays from 60Co were determined. The minimum clone size to be chosen for definition of true survivors was examined. RBE values of 1.0 +- 0.1, 1.4 +- 0.2, and 1.5 +- 0.2, respectively, were found and compared with the results of other experiments in this energy range

  1. Radiation accompanying the absorption of 2-MeV protons in various materials

    Kasatov, D. A.; Makarov, A. N.; Taskaev, S. Yu.; Shchudlo, I. M.

    2015-11-01

    For the development of boron neutron-capture therapy of malignant tumors, a source of epithermal neutrons on the basis of a tandem accelerator with a vacuum insulation and a lithium target was created and launched. With the aim of optimizing the neutron-producing target, various structure materials were irradiated with a proton beam. The results obtained bymeasuring the dose rate and radiation spectrum upon the absorption of 2-MeV protons are presented, and the choice of tantalum for an optimum material of the target substrate was explained.

  2. Dosimetric characterization of CVD diamonds irradiated with 62 MeV proton beams

    Cirrone, G.A.P. [Laboratori Nazionali del Sud, INFN, Catania (Italy)]. E-mail: cirrone@lns.infn.it; Cuttone, G. [Laboratori Nazionali del Sud, INFN, Catania (Italy); Lo Nigro, S. [Laboratori Nazionali del Sud, INFN, Catania (Italy); Dipartimento di Fisica ed Astronomia, Universita di Catania (Italy); CSFNSM Centro Siciliano di Fisica Nucleare e Struttura della MAteria, Catania (Italy); Mongelli, V. [Laboratori Nazionali del Sud, INFN, Catania (Italy); Scuola di Specializzazione in Fisica Sanitaria, Universita di Catania (Italy); CSFNSM Centro Siciliano di Fisica Nucleare e Struttura della MAteria, Catania (Italy); Raffaele, L. [Laboratori Nazionali del Sud, INFN, Catania (Italy); Sabini, M.G. [Laboratori Nazionali del Sud, INFN, Catania (Italy); Azienda Ospedaliera Cannizzaro, Catania (Italy); Valastro, L. [Laboratori Nazionali del Sud, INFN, Catania (Italy); Scuola di Specializzazione in Fisica Sanitaria, Universita di Catania (Italy); Bucciolini, M. [Dipartimento di Fisiopatologia Clinica, Universita di Florence (Italy); Onori, S. [Istituto Superiore di Sanita, Rome (Italy)

    2005-10-21

    Diamond is potentially a very suitable material for use as on-line radiation dosimeter. Recent advances in the synthesis of polycrystalline diamond by chemical vapor deposition (CVD) techniques have produced material with electronic properties suitable for dosimetry applications. In this work the possibility to use a segmented commercial CVD detector in the dosimetry of proton beams has been investigated. The response as function of dose, dose rate, the priming and the rise time have been investigated thoroughly. This study shows the suitability of CVD diamond for dosimetry of clinical 62 MeV proton beams.

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

    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.

  4. Measurement of the angular distribution of neutron-proton scattering at 10 MeV

    The relative angular distribution of neutrons scattered from protons was measured at an incident neutron energy of 10 MeV at the Ohio University Accelerator Laboratory. An array of 11 detector telescopes at laboratory angles of 0 to 60 degrees was used to detect recoil protons from neutron interactions with a CH2 (polypropylene) target. Data for 7 of these telescopes were obtained with one set of electronics and are presented here. These data, from 108 to 180 degrees for the center-of-mass scattering angles, have a small slope which agrees better with angular distributions predicted by the Arndt phase shifts than with the ENDF/B-VI angular distribution

  5. Radiochemical measurement of 10-15 MeV proton induced fission yields for U-238

    The production of realistic nuclear forensics debris requires an accurate knowledge of cross sections and fission yields for large number of systems. Proton induced fission of U-238 was examined for incident energies in the range of 10-15 MeV. Fission yields were first measured directly from the irradiated materials. The valley and wing fission products were then isolated in various chemical fractions in order to increase the counting statistics leading to improvements in the fission yields. In addition to the total fission cross section and the fission mass yields for U-238, proton based reaction cross sections on U-238 and U-235 were also measured. (author)

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

    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.

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

    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).

  8. Commissioning of the CERN LINAC4 BPM System with 50 Mev Proton Beamns

    Tan, J; Søby, L; Sordet, M; Wendt, M

    2013-01-01

    The new Linac4 at CERN will provide a 160 MeV H- ion beam for charge-exchange injection into the existing CERN accelerator complex. Shorted stripline pick-ups placed in the Linac intertank regions and the transfer lines will measure beam orbit, relative beam current, beam phase, and average beam energy via the time-of-flight between two pickups. A prototype Beam Position Monitor (BPM) system has been installed in the transfer line between the existing Linac2 and the Proton Synchrotron Booster (PSB) in order to study and review the complete acquisition chain. This paper presents measurements and performance of this BPM system operating with 50 MeV proton beams, and compares the results with laboratory measurements and electromagnetic simulations.

  9. The optimization for the conceptual design of a 300 MeV proton synchrotron

    An, Yuwen; Wang, Sheng; Huang, Liangsheng

    2016-01-01

    A research complex for aerospace radiation effects research has been proposed in Harbin Institute of Technology. Its core part is a proton accelerator complex, which consists of a 10 MeV injector, a 300 MeV synchrotron and beam transport lines. The proton beam extracted from the synchrotron is utilized for the radiation effects research. Based on the conceptual design [1], the design study for optimizing the synchrotron has been done. A new lattice design was worked out, and the multi-turn injection and slow extraction system were optimized with the new lattice design. In order to improve the time structure of the extracted beam, a RF knock-out method is employed. To meet the requirement of accurate control of dose, the frequency of the RF kicker is well investigated.

  10. Formation of Cavities at and Away from Grain Boundaries during 600 MeV Proton Irradiation

    Singh, Bachu Narain; Leffers, Torben; Green, W. V.; Green, S. L.

    1982-01-01

    High-purity aluminium (99.9999%) was irradiated with 600 MeV protons at the Swiss Institute for Nuclear Research (SIN) with a damage rate of 3,5 x 10^-6 dpa/s. Irradiation with 600 MeV protons produces helium, hydrogen, and other impurities through mutational reactions. The irradiation experiments...... were carried out at 120 degree C (0,42*Tm where Tm is the melting temperature in K). Transmission electron microscopy on specimens irradiated to 0.2 and 0.6 dpa has shown the presence of (a) cavity-denuded zones (CDZ) along grain boundaries, (b) cavity-containing zones (CCZ) adjacent to the CDZ and (c...

  11. Scanning transmission ion microscopy (STIM) with a 3 MeV proton cyclotron beam

    Maanen, I.F. van [Technische Univ., Eindhoven (Netherlands). Cyclotron Lab.; Mutsaers, P.H.A. [Technische Univ., Eindhoven (Netherlands). Cyclotron Lab.; Verhoef, B.A.W. [Technische Univ., Eindhoven (Netherlands). Cyclotron Lab.; Voigt, M.J.A. de [Technische Univ., Eindhoven (Netherlands). Cyclotron Lab.

    1996-06-01

    A method is developed to optimize the lateral resolution of a scanning proton microprobe using a 3 MeV cyclotron beam. The most important part of the method is the optimization of an asymmetrical quadrupole quadruplet, based on second-order relationships between diaphragm widths and the full width of the spot. A STIM example is presented of cellular structures of rat-heart tissue. (orig.).

  12. Scanning transmission ion microscopy (STIM) with a 3 MeV proton cyclotron beam

    A method is developed to optimize the lateral resolution of a scanning proton microprobe using a 3 MeV cyclotron beam. The most important part of the method is the optimization of an asymmetrical quadrupole quadruplet, based on second-order relationships between diaphragm widths and the full width of the spot. A STIM example is presented of cellular structures of rat-heart tissue. (orig.)

  13. Introduction of solid state RF sources at the KEK 40-MeV proton linac

    At the KEK 40-MeV proton linac, solid state rf power amplifiers were introduced into rf sources for the two tanks of the DTL and for the prebuncher; furthermore, introduction to the debuncher's rf source is now in progress. These rf sources have been operated stably without any problem. In this paper, the solid state rf sources and their operational results are described. (author)

  14. Grain Boundary Related Effects in Aluminium during 600 MeV Proton Irradiation of Different Temperatures

    Singh, Bachu Narain; Leffers, Torben; Green, W.V.; Victoria, M.

    Samples of high-purity aluminium were irradiated with 600 MeV protons at temperatures in the range 130 to 433°C; in these experiments 615 and 125 appm of hydrogen and helium, respectively, are produced per dpa. Bubble formation and growth at grain boundaries and in the zone adjacent to the bubble......-denuded zone are described. Precipitation at grain boundaries and migration of grain boundaries during irradiation are also reported....

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

    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.

  16. 25 MeV Solar Proton Events in Cycle 24 and Previous Cycles

    Richardson, Ian G; Cane, Hilary V

    2016-01-01

    We summarize observations of around a thousand solar energetic particle (SEP) events since 1967 that include ~25 MeV protons made by various near-Earth spacecraft (IMPs 4, 5, 7, 8, ISEE 3, SOHO), encompassing solar cycles 20 to the current cycle (24). We also discuss recent observations of similar SEP events in cycle 24 from the STEREO spacecraft. The observations show, for example, that the time distribution of 25 MeV proton events varies from cycle to cycle. In particular, the time evolution of the SEP occurrence rate in cycle 24 is strongly asymmetric between the northern and southern solar hemispheres, and tracks the sunspot number in each hemisphere, whereas cycle 23 was more symmetric. There was also an absence of 25 MeV proton events during the solar minimum preceding cycle 24 (other minima show occasional, often reasonably intense events), and, so far, there have been few exceptionally intense events in cycle 24 compared to cycles 22 and 23, though cycle 21 also apparently lacked such events. We note ...

  17. Inelastic proton scattering at 30--40 MeV from 12C

    Elastic and inelastic proton differential cross sections for excitation of the following levels of 12C: 21+(4.43 MeV), 41+(14.08 MeV), 02+(7.65 MeV), and 31-(9.64 MeV) have been measured at three incident energies between 30 and 40 MeV. The data have been described by coupled channel calculations and form factors obtained by coupling surface vibrations to static deformations. The reproduction of the 02+ state data, if this state is assumed to be a β-vibrational state, requires a quadrupole β-vibrational amplitude which is 57% of the static quadrupole deformation and a mixing of the breathing mode of the nucleus with an amplitude that would correspond to about 1% of the E0 energy weighted sum rule. For the 31- state it is found that the performed calculations are sensitive to the K projection, with the angular distribution of the 31- state being better fitted assuming K/sup π/ = 3- band. Coupled channel calculations using microscopic form factors obtained from wave functions generated using the resonating group method have also been performed and are compared to the experimental data

  18. Mechanical properties testing of several 800 MeV proton irradiated BCC metals and alloys

    A spallation neutron source for the 600-MeV proton accelerator facility at the Swiss Institute for Nuclear Research (SIN) consists of a vertical cylinder filled with molten Pb-Bi. The proton beam enters the cylinder, passing upward through a window in contact with the Pb-Bi eutectic liquid. Investigations are underway at the 800-MeV proton accelerator at LAMPF to test the performance of candidate SIN window materials. Based on considerations of chemical compatibility with molten Pb-Bi, as well as radiation damage mechanisms, Fe, Ta, Fe-2.25Cr-1Mo, and Fe-12Cr-1Mo (Ht-9) were chosen as candidate materials. Sheet tensile samples were sealed inside capsules containing Pb-Bi and were proton-irradiated at LAMPF to two fluences, 4.8 and 54 x 1023 p/m2. The beam current was approximately equal to the 1 mA anticipated for the upgraded SIN accelerator. Yield and ultimate strengths increased upon irradiation in all materials, while the ductility decreased. The pure metals, Ta and Fe, exhibited the greatest radiation hardening and embrittlement. The HT-9 alloy showed the smallest changes in strength and ductility

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

    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

  20. Impurity induced neutralization of MeV energy protons in JET plasmas

    Gondhalekar, A. [Commission of the European Communities, Abingdon (United Kingdom). JET Joint Undertaking; Korotkov, A.A. [AF Ioffe Institute, Saint Petersburg (Russian Federation)

    1994-07-01

    A model elucidating the role of carbon and beryllium, the main impurities in JET plasmas, in neutralizing MeV energy protons, which arise during ICRF heating of deuterium plasmas in the hydrogen minority heating mode D(H), and from D-D fusion reactions, is presented. The model establishes charge transfer from hydrogen-like impurity ions to protons as the main process for neutralization. Calculations for deducing the proton energy distribution function from measured hydrogen flux are described. The validity of the model is tested by using it to described the measured flux in different conditions of plasma heating and fueling. Further, it is used to deduce the background thermal deuterium atom density at the plasma center. 9 refs., 6 figs.

  1. Single event upsets calculated from new ENDF/B-VI proton and neutron data up to 150 MeV

    Chadwick, M.B. [Los Alamos National Lab., NM (United States). Theoretical Div.; Normand, E. [Boeing Military Aircraft and Missile Systems, Seattle, WA (United States)

    1999-06-01

    Single-event upsets (SEU) in microelectronics are calculated from newly-developed silicon nuclear reaction recoil data that extend up to 150 MeV, for incident protons and neutrons. Calculated SEU cross sections are compared with measured data.

  2. Large angle proton emission in the 9Be(p,2p) reaction at 300 MeV

    A 9Be(p,2p) coincidence experiment performed to to further elucidate the reaction mechanism for the production of energetic wide-angle protons in intermediate energy proton induced reactions is reported. Detectors in a coplanar geometry were used to measure coincidences between trigger protons at 90 degrees to the beam and forward angle protons on the opposite side of the beam. The incident proton energy was 300 MeV. The authors report both the inclusive spectra for the trigger protons and the differential mean multiplicities for the coincidence events

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

    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)

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

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

    2013-01-01

    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 He3 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.

  5. Studies of scintillator response to 60 MeV protons in a proton beam imaging system

    Rydygier Marzena

    2015-09-01

    Full Text Available A Proton Beam Imaging System (ProBImS is under development at the Institute of Nuclear Physics, Polish Academy of Sciences (IFJ PAN. The ProBImS will be used to optimize beam delivery at IFJ PAN proton therapy facilities, delivering two-dimensional distributions of beam profiles. The system consists of a scintillator, optical tract and a sensitive CCD camera which digitally records the light emitted from the proton-irradiated scintillator. The optical system, imaging data transfer and control software have already been developed. Here, we report preliminary results of an evaluation of the DuPont Hi-speed thick back screen EJ 000128 scintillator to determine its applicability in our imaging system. In order to optimize the light conversion with respect to the dose locally deposited by the proton beam in the scintillation detector, we have studied the response of the DuPont scintillator in terms of linearity of dose response, uniformity of light emission and decay rate of background light after deposition of a high dose in the scintillator. We found a linear dependence of scintillator light output vs. beam intensity by showing the intensity of the recorded images to be proportional to the dose deposited in the scintillator volume.

  6. Radiation protection studies for a high-power 160 MeV proton linac

    Mauro, Egidio

    2009-01-01

    CERN is presently designing a new chain of accelerators to replace the present Proton Synchrotron (PS) complex: a 160 MeV room-temperature H− linac (Linac4) to replace the present 50 MeV proton linac injector, a 3.5 GeV Superconducting Proton Linac (SPL) to replace the 1.4 GeV PS Booster (PSB) and a 50 GeV synchrotron (named PS2) to replace the 26 GeV PS. Linac4 has been funded and the civil engineering work started in October 2008, whilst the SPL is in an advanced stage of design. Beyond injecting into the future 50 GeV PS, the ultimate goal of the SPL is to generate a 4 MW beam for the production of intense neutrino beams. The radiation protection design is driven by the latter requirement. This work summarizes the radiation protection studies conducted for Linac4. FLUKA Monte Carlo simulations, complemented by analytical estimates, were performed to evaluate the propagation of neutrons through the waveguide, ventilation and cable ducts placed along the accelerator, to estimate the radiological impact of ...

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

    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.)

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

    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.

  9. Cross Sections from 800 MeV Proton Irradiation of Terbium

    Engle, J W; Bach, H; Couture, A; Jackman, K; Gritzo, R; Ballard, B D; Faßbender, M; Smith, D M; Bitteker, L J; Ullmann, J L; Gulley, M; Pillai, C; John, K D; Birnbaum, E R; Nortier, F M

    2012-01-01

    A single terbium foil was irradiated with 800 MeV protons to ascertain the potential for production of lanthanide isotopes of interest in medical, astrophysical, and basic science research and to contribute to nuclear data repositories. Isotopes produced in the foil were quantified by gamma spectroscopy. Cross sections for 36 isotopes produced in the irradiation are reported and compared with predictions by the MCNP6 transport code using the CEM03.03, Bertini, and INCL+ABLA event generators. Our results indicate the need to accurately consider fission and fragmentation of relatively light target nuclei like terbium in the modeling of nuclear reactions at 800 MeV. The predictive power of the code was found to be different for each event generator tested but was satisfactory for most of the product yields in the mass region where spallation reactions dominate. However, none of the event generators' results are in complete agreement with measured data.

  10. Neutron shielding verification measurements and simulations for a 235-MeV proton therapy center

    Newhauser, W D; Dexheimer, D; Yan, X; Nill, S

    2002-01-01

    The neutron shielding at the Massachusetts General Hospital's 235-MeV proton therapy facility was investigated with measurements, analytical calculations, and realistic three-dimensional Monte Carlo simulations. In 37 of 40 cases studied, the analytical calculations predicted higher neutron dose equivalent rates outside the shielding than the measured, typically by more than a factor of 10, and in some cases more than 100. Monte Carlo predictions of dose equivalent at three locations are, on average, 1.1 times the measured values. Except at one location, all of the analytical model predictions and Monte Carlo simulations overestimate neutron dose equivalent.

  11. Neutron-proton spin-correlation parameter Azz at 68 MeV

    We report a first measurement of the spin-correlation parameter Azz in neutron-proton scattering at 67.5 MeV. The results, obtained in the angular range 105 degree ≤θc.m.≤170 degree with typical accuracies of 0.008, are highly sensitive to the 3S1-3D1 mixing parameter ε1. A phase-shift analysis based on the current world data yields a value of ε1 significantly higher than predicted by modern potential models

  12. Nuclear excitation functions from 40-200 MeV proton irradiation of terbium

    Engle, Jonathan W.; Mashnik, Stepan G.; Parker, Lauren A.; Jackman, Kevin R.; Bitteker, Leo J.; Ullmann, John L.; Gulley, Mark S.; Pillai, Chandra; John, Kevin D.; Birnbaum, Eva R.; Nortier, Francois M.

    2015-01-01

    Nuclear formation cross sections are reported for 26 radionuclides, measured with 40 to 200 MeV proton irradiations of terbium foils. These data are relevant to the production of medically relevant radionuclides (e.g., 152Tb, 155Tb, 155Eu, and 156Eu) and to ongoing efforts to characterize stellar nucleosynthesis routes passing through long-lived intermediaries (e.g., 153Gd). Computational predictions from the ALICE2011, CEM03.03, Bertini, and INCL+ABLA codes are compared with newly measured d...

  13. Application of 12 MeV proton activation to the analysis of archaeological specimens

    12 MeV proton activation analysis is applied to a variety of archaeological specimens (glass, pottery, mortar and ivory) and its usefulness studied. The method is non-destructive and Ca, Ti, V, Cr, Fe, Cu, Zn, As, Sr, Y, Zr and Sb, ranging from percentage to parts per million (ppm) level were determined. The detection limits in archaeological glass for Ti, V, Cr, Fe, As, Sr, Y and Zr are at 1-10 ppm level; Cu, Zn and Sb at 20-35 ppm level, and Ca at 150 ppm level. (author)

  14. Nuclear excitation functions from 40-200 MeV proton irradiation of terbium

    Engle, Jonathan W; Parker, Lauren A; Jackman, Kevin R; Bitteker, Leo J; Ullmann, John L; Gulley, Mark S; Pillai, Chandra; John, Kevin D; Birnbaum, Eva R; Nortier, Francois M

    2015-01-01

    Nuclear formation cross sections are reported for 26 radionuclides, measured with 40 to 200 MeV proton irradiations of terbium foils. These data are relevant to the production of medically relevant radionuclides (e.g., 152Tb, 155Tb, 155Eu, and 156Eu) and to ongoing efforts to characterize stellar nucleosynthesis routes passing through long-lived intermediaries (e.g., 153Gd). Computational predictions from the ALICE2011, CEM03.03, Bertini, and INCL+ABLA codes are compared with newly measured data to contribute to the ongoing process of code development, and yields are calculated for selected radionuclides using measured data.

  15. Neutron-proton charge-exchange amplitudes at 585 MeV

    Chiladze, D; Dzyuba, A; Dymov, S; Glagolev, V; Hartmann, M; Kacharava, A; Keshelashvili, I; Khoukaz, A; Komarov, V; Kulessa, P; Kulikov, A; Lomidze, N; Macharashvili, G; Maeda, Y; Mchedlishvili, D; Mersmann, T; Merzliakov, S; Mielke, M; Mikirtychyants, S; Nekipelov, M; Nioradze, M; Ohm, H; Rathmann, F; Ströher, H; Tabidze, M; Trusov, S; Uzikov, Yu; Valdau, Yu; Wilkin, C

    2008-01-01

    The differential cross section and deuteron analysing powers of the dp -> {pp}n charge-exchange reaction have been measured with the ANKE spectrometer at the COSY storage ring. Using a deuteron beam of energy 1170 MeV, data were obtained for small momentum transfers to a {pp} system with low excitation energy. A good quantitative understanding of all the measured observables is provided by the impulse approximation using known neutron-proton amplitudes. The proof of principle achieved here for the method suggests that measurements at higher energies will provide useful information in regions where the existing np database is far less reliable.

  16. The scattering of 136 MeV protons from 6Li

    Differential cross sections have been measured for the elastic scattering of 136 MeV protons from 6Li, and for inelastic scattering to the first two excited states. The optical model fit to the elastic scattering differential cross section gave parameters which were retained for the analysis of the two inelastic transitions. The latter differential cross sections were fairly well fitted in shape, but in both cases there is a discrepancy in absolute magnitude of a factor between 1.5 and 4

  17. Proton-nucleus scattering with energies 40 to 800 MeV

    Exchange amplitudes in full folding models of nucleon-nucleus optical potentials lead to strong non-locality. When that non-locality is properly taken into account, differential cross sections and analyzing powers from elastic scattering with 40 to 800 MeV protons are predicted that are in very good agreement with scattering data. The procedure explains observed data from the radioactive beam experiments in which exotic, halo nuclei, are scattered from hydrogen targets. With a no parameter distorted wave approximation, inelastic scattering data (from 6He specifically) can be explained

  18. Excitation of resonant oscillations in a solid bar by 30-MeV protons

    The mechanical response of a metallic bar to pulses of 30-MeV protons has been investigated. It was found that by making the pulse duration short in comparison with the periods of the low-order harmonics of the bar resonant oscillations, vibration amplitudes of the order of 10-11 cm could be measured. The required energy loss by the beam pulses amounted to about 10-5 J, and very simple theoretical considerations suffice to relate quantitatively the deposition of energy in the bar with the amplitudes of its natural vibrational modes

  19. Activation cross sections of proton induced nuclear reactions on gold up to 65MeV.

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

    2016-07-01

    Activation cross sections of proton induced reactions on gold for production of (197m,197g,195m,195g, 193m,193g,192)Hg, (196m,196g(cum),195g(cum),194,191(cum))Au, (191(cum))Pt and (192)Ir were measured up to 65MeV proton energy, some of them for the first time. The new data are in acceptably good agreement with the recently published earlier experimental data in the overlapping energy region. The experimental data are compared with the predictions of the TALYS 1.6 (results in TENDL-2015 on-line library) and EMPIRE 3.2 code. PMID:27156194

  20. Stopping cross sections of liquid water for MeV energy protons

    Cross sections for the stopping of swift protons in liquid water have been measured for the first time by using a liquid water jet target of 50 μm in diameter. The energy loss spectra of incident 2.0 MeV protons were measured at scattering angles of 5.0-50 mrad. Experimental energy loss spectra have been successfully reproduced by Monte Carlo simulation calculations (GEANT4.9.1.p02 toolkit) by taking account of multiple scattering of projectile ions inside the liquid water target. The present stopping cross sections are found to be considerably smaller than other standard stopping power data, revealing e.g. about 11% deviation from those of SRIM2003.

  1. Stopping cross sections of liquid water for MeV energy protons

    Shimizu, M. [Department of Nuclear Engineering, Kyoto University, Kyoto 606-8501 (Japan)], E-mail: m-shimizu@nucleng.kyoto-u.ac.jp; Kaneda, M.; Hayakawa, T. [Department of Nuclear Engineering, Kyoto University, Kyoto 606-8501 (Japan); Tsuchida, H. [Quantum Science and Engineering Center, Kyoto University, Kyoto 606-8501 (Japan); Itoh, A. [Department of Nuclear Engineering, Kyoto University, Kyoto 606-8501 (Japan)

    2009-08-15

    Cross sections for the stopping of swift protons in liquid water have been measured for the first time by using a liquid water jet target of 50 {mu}m in diameter. The energy loss spectra of incident 2.0 MeV protons were measured at scattering angles of 5.0-50 mrad. Experimental energy loss spectra have been successfully reproduced by Monte Carlo simulation calculations (GEANT4.9.1.p02 toolkit) by taking account of multiple scattering of projectile ions inside the liquid water target. The present stopping cross sections are found to be considerably smaller than other standard stopping power data, revealing e.g. about 11% deviation from those of SRIM2003.

  2. Helium and displacement damage produced by 600 MeV proton beams in high purity aluminum

    Pure aluminum samples (99.9999%) have been irradiated in the Proton Irradiation Experiment (PIREX) installed in the 600 MeV proton beam of the accelerator in the Swiss Nuclear Research Institute (SIN), at temperatures between 400K and 500K and displacement doses between 0.9 and 5 displacements per atom (dpa). Average displacement rate is 3.5 X 10-6 dpa/s. The specimens were analyzed for both 3He and 4He. Measured helium content is 215 atomic parts per million (appm)/dpa. No diffusional spreading of sodium or helium was measured. The helium bubble structure was examined and shows a swelling of 0.16% at about5 dpa

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

    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

  4. Proton--proton analyzing power measurements at 16 MeV

    Few attempts have been made to measure accurately the proton-proton analyzing powers at low energies. With the advent of polarized particle beams the measurement can now be made with high accuracy. Analyzing powers were measured at nine scattering angles from 100 to 350 in the laboratory system. As a check on systematic errors, analyzing power measurements were also made by scattering protons from 4He. In the p Vector-p case the measured values are in very good agreement with the phase shift predictions. The p Vector-4He measurements, while giving the same form and sign as the phase shift predictions, differ from the predictions by as much as 11 standard deviations. The p Vector-p analyzing powers had a maximum value of -0.0043 +- 0.0004 at 100 (laboratory) and decreased to zero near 250. A new technique to measure analyzing powers without symmetric detectors is explained. This technique preserves the advantages of the symmetric arm method in that current integration, target density, detector efficiencies, and geometry are cancelled from the final expressions. A new scattering chamber, named the Supercube, is described. The Supercube was designed primarily to perform scattering experiments with a polarized beam. It contains both left-right and up-down detectors for use with both spin-1/2 and spin-1 measurements. The Supercube was designed to make analyzing power measurements to an accuracy of 0.001 routine. The Supercube has proved to have low systematic errors and to perform as expected. The systematic errors were found to be equal to or less than 0.0002. (23 figures, 14 tables) (auth)

  5. Neutron production for 250 MeV protons bombarding on thick grain-made tungsten target

    Zhang, Xueying; Zhang, Yanbin; Ma, Fei; Ju, Yongqin; Chen, Liang; Wang, Jianguo; Ge, Honglin [Chinese Academy of Sciences, Institute of Modern Physics, Lanzhou (China); Zhang, Hongbin; Li, Yanyan; Wan, Bo [Chinese Academy of Sciences, Institute of Modern Physics, Lanzhou (China); University of Chinese Academy of Sciences, Beijing (China)

    2015-08-15

    Neutron yield for 250 MeV protons incident on a tungsten target has been measured using the water bath method. The target was made of many randomly placed tungsten grains. Through analyzing the activity of Au foils, the neutron flux distribution in water was obtained. The neutrons slowing down process shows that the neutrons from tungsten have an average energy lower than neutrons from the lead target. The neutron yield was experimentally determined to be 2.02 ± 0.15 neutron/proton. Detailed simulation was also performed with the Geant4 toolkit. Comparison has been made with the experimentally derived neutron yield. It was found that, around 250 MeV, experimental results were described satisfactorily with a combination of high-energy spallation, low-energy neutron reaction and scattering. It was shown that the grain-packed target does not affect much the main neutronic properties, which are of crucial importance for the design of the spallation target. (orig.)

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

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

    1999-01-01

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

  7. Neutron spectrum measurements at a 40-MeV proton cyclotron

    Birattari, C.; Salomone, A.

    1985-11-01

    A set of seven activation reactions has been selected for neutron spectral analysis in the environment of a proton-cyclotron target. This choice of reactions: 59Co(n, p) 59Fe, 59Co(n, 2n) 58Co, 59Co(n, 3n) 57Co, 197Au(n, gamma) 198Au, 197Au(n, 2n) 196Au, 197Au(n, 4n) 194Au, 27Al(n, alpha) 24Na, analyzed by means of a Ge(Li) detector, reduces to a minimum of three the number of activation detectors employed, and makes possible convenient and accurate spectral measurements to at least 40 MeV. Criteria for selection of the activation materials from a list of candidates are discussed. A detailed comparison of the unfolding programs LYRA and SAND is made, and reasons are given for our choice of SAND in our application. Spectra of neutrons emitted at 0 degrees, 45 degrees and 90 degrees from thick targets of A1, Fe, Cu, Ta and stainless steel, irradiated by 40-MeV protons at the Milan AVF cyclotron, using the analysis technique described, are given and discussed.

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

    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

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

    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

  10. A novel source of MeV positron bunches driven by energetic protons for PAS application

    Tan, Zongquan; Xu, Wenzhen; Liu, Yanfen; Xiao, Ran; Kong, Wei; Ye, Bangjiao

    2014-11-01

    This paper proposes a novel methodology of MeV positrons generation for PAS application. Feasibility of this proposal analyzed by G4Beamline and Transport have shown reasonable success. Using 2 Hz, 1.6 GeV, 100 ns and 1.5 μC/bunch proton bunches for bombarding a graphite target, about 100 ns e+ bunches are generated. Quasi-monochromatic positrons in the range of 1-10 MeV included in these bunches have a flux of >107/s, peak brightness of 1014/s. A magnetic-confinement beamline is utilized to transport the positrons and a "Fast Beam Chopper" is unprecedentedly extended to chop those relativistic bunches. The positron beam can be finally characterized by the energy range of 1-10 MeV and bunch width from one hundred ps up to 1 ns. Such ultrashort bunches can be useful in tomography-type positron annihilation spectroscopy (PAS) as well as other applications.

  11. Inclusive proton spectra and total reaction cross sections for proton-nucleus scattering at 800 MeV

    Current applications of multiple scattering theory to describe the elastic scattering of medium energy protons from nuclei have been shown to be quite successful in reproducing the experimental cross sections. These calculations use the impulse approximation, wherein the scattering from individual nucleons in the nucleus is described by the scattering amplitude for a free nucleon. Such an approximation restricts the inelastic channels to those initiated by nucleon-nucleon scattering. As a first step in determining the nature of p + nucleus scattering at 800 MeV, both total reaction cross sections and (p,p') inclusive cross sections were measured and compared to the free p + p cross sections for hydrogen, deuterium, calcium 40, carbon 12, and lead 208. It is concluded that as much as 85% of all reactions in a nucleus proceed from interactions with a single nucleon in the nucleus, and that the impulse approximation is a good starting point for a microscopic description of p + nucleus interactions at 800 MeV

  12. Independent isotopic yields in 25 MeV and 50 MeV proton-induced fission of natU

    Penttilä, H.; Gorelov, D.; Elomaa, V.-V.; Eronen, T.; Hager, U.; Hakala, J.; Jokinen, A.; Kankainen, A.; Karvonen, P.; Moore, I. D.; Parkkonen, J.; Peräjärvi, K.; Pohjalainen, I.; Rahaman, S.; Rinta-Antila, S.; Rissanen, J.; Rubchenya, V. A.; Saastamoinen, A.; Simutkin, V.; Sonoda, T.; Weber, C.; Voss, A.; Äystö, J.

    2016-04-01

    Independent isotopic yields for elements from Zn to La in the 25 MeV proton-induced fission of {}^{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 {}^{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.

  13. Radiobiological characteristics of the medical 1000 MeV proton beam

    The effect of a narrow proton beam with an energy of 1000 MeV was studied by means of the survival test in a phantom behind 7 g/cm2 of mouse material in the haploid prototrophic strain of yeast cells and by the response of canine cerebral tissue in the area of the central ray and at the edge of the range of action. Following the survival test the relative biological effectiveness (RBE) after the action of primary protons and of secondary particles on yeast cells was estimated for the depth with approximately 1 related to the therapeutic X radiation. The damaging radiation effect to yeast cells was found to be limited to a distance of 60 mm which nearly corresponds to the 0.1 - 0.2% isodose with a dose of 10,000 Gy in the middle. The effect on the brain consists of circumscript necroses in the area of radiation focussing and of a narrow about 1 mm wide area of perifocal changes. The neighbouring cerebral structures are widely intact. Reasons are given for the possible use of a proton beam for stereotactical interventions using the rotational couvergent-beam irradiation technique. (author)

  14. Near realtime forecasting of MeV protons on the basis of sub relativistic electrons

    Labrenz, Johannes; Heber, Bernd; Kuehl, Patrick; Sarlanis, Christos; Malandraki, Olga; Posner, Arik

    2016-04-01

    A major impact on human and robotic space exploration activities is the sudden and prompt occurrence of solar energetic ion events. In order to provide up to an hour warning before these particles arrive at Earth, relativistic electron and below 50 MeV proton data from the Electron Proton Helium Instrument (EPHIN) on SOHO were used to implement the 'Relativistic Electron Alert System for Exploration (REleASE)'. It has been demonstrated that the analysis of relativistic electron time profiles provides a low miss and false alarm rate. High Energy Solar Particle Events foRecastIng and Analysis (HESPERIA) is a project funded within the European Union's Horizon 2020 research and innovation programme (PROTEC-1-2014 Call: Space Weather). Within this project the REleASE forecasting scheme was rewritten in the open access programming language PYTHON and will be made public. As a next step, we have analyzed the possibility to also use, along with relativistic electrons (v > 0.9 c) provided by SOHO, near-relativistic (v forecasting scheme to provide reliable SEP forecasts. A comparison of measured and forecast proton intensities by SOHO/EPHIN and ACE/EPAM will be presented. In addition we investigated the false alarm rate and detection probability of solar ion events. This project has received funding from the European Union's Horizon 2020 research and innovation programme under grant agreement No 637324.

  15. Simulation of Neutron Production in Selected Targets by Proton and Deuteron Beam in Energy Range from 10 MeV to 75 MeV

    Initial inter-comparison study of simulation of neutron production by beam of protons and deuterons in different target materials, in energy range from 10 MeV to 75 MeV, is shown in the paper. An idealised cylindrical (diameter = height = 2.5 cm) target is bombarded, along the central axis, perpendicularly at target base, by an infinite thin particle beam. Simulation is carried out for the target surrounded by void, i.e., the 'return effect' from surrounding materials in a real system is not encountered. The study is carried out using Monte Carlo based computer codes for intermediate and high-energy nucleon transport: LCS, ver.2.7 (LANL, USA) and SHIELD (INR, Russia). Yield (total number of neutrons in 4 , per incident particle) and spectrum of neutrons escaping the target surfaces are determined for different targets made from 208Pb/Pb, 238U/U, 184W/W, Be and 7Li. Maximum neutron yield, near 30%, is calculated for proton beam energy of 75 MeV bombarding 238U/U target, shaped as mentioned above. Generally, neutron yield for deuteron beam is less than neutron yield for proton beam of the same energy for targets made from high-Z nuclides. The opposite conclusion is derived for targets made from low-Z nuclides. (author)

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

    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)

  17. Effects of 70 MeV proton beam on a murine tumor and skin

    Biological effectiveness of 70 MeV proton beam generated from the NIRS cyclotron was studied. Seventh generation of a squamous cell carcinoma which arose spontaneously in a C3H/f female mouse was monodispersed by trypsin, and 1.2 x 105 cells were transplanted s.c. into right hind legs of syngeneic male mice. Five days after transplantation, legs with tumors were irradiated under nembutal anaesthesia. Tumor sizes were measured periodically up to 60 days. Time required for a tumor to grow 12.0 mm in diameter was obtained from culculations by use of computer, and termed as TG (tumor growth) time. TGD (Tumor growth deley) time, a difference of TG time between experimental and control groups, was used as an endpoint for tumor. For measurement of skin reaction, hair on right hind legs were depilated by depilatory 7 days before irradiation. Skin reaction was scored every other day up to 35 days, and mean skin reactions were employed as another endpoint. 30 mm spread out Bragg peak (SOBP) in water was used in proton irradiation, and its dose rate was about 90 Gy/min. The reference beam used here was 200 kVp X-ray with dose rate of 2.4 Gy/min. In the first experiment, biological effect of modulated proton beam was examined as a function of penetration depth. Depth was varied by applying various thickness of lucite plates. Tumor and skin effects were found to be very similar to the physical depth-dose distribution. Secondly, we examined relative biological effectiveness (RBE) of proton beam in the spread out Bragg peak, being at 15 mm depth in Lucite. RBEs were 0.82 for skin and 0.79 for tumor. Thereby, therapeutic gain factor (TGF) of 0.96 was obtained in our system. (author)

  18. Polarized proton scattering on lithium isotopes at 14 MeV

    Differential cross sections, analyzing powers, and double differential cross sections for the 6,7Li(p,p') scattering have been measured at an incident energy of 14 MeV. Experimental procedures and results are briefly described. The experimental data of the elastic scattering have excellently been reproduced by calculations based on the spherical optical model (SOM) and the coupled channel (CC) method. The DWBA and CC calculations have not correctly predicted the analyzing powers in the inelastic channels leading to the 1st and 2nd excited states of 6,7Li. The three-body breakup process observed in the (p,p') continuum spectra has been qualitatively explained by DWBA calculations with the discretized-continuum states. The experimental and theoretical results are compared with neutron scattering data. Studies on proton scattering are valuable for modelling of nuclear reactions and for evaluation of neutron scatterings. (author)

  19. Track nanodosimetry of 20-MeV protons at 20 nm.

    Conte, V; Colautti, P; De Nardo, L; Ferretti, A; Poggi, M; Moro, D; Lombardi, M; Tornielli, G; Grosswendt, B

    2011-02-01

    Track nanodosimetry is the theoretical and experimental research which studies the stochastic aspects of ionisation yield produced by ionising particles in nanometric target volumes, positioned at different distances from the primary particle track. The STARTRACK experimental set-up, mounted on the +50° beam line at the Tandem-Alpi particle accelerator of Legnaro National Laboratories, has been conceived to give an experimental basis to nanodosimetric calculations. STARTRACK is a detection system able to measure the ionisation cluster-size distributions in a 20 nm propane site, by counting the electrons set in motion by different ion tracks, with the resolution of one electron. The 'sensitive volume' SV can be moved at different distances from the primary particle track (different impact parameter). Distributions of 20-MeV protons have been measured and compared with Monte Carlo calculations. PMID:21127036

  20. Research program for the 660 MeV proton accelerator driven MOX-plutonium subcritical assembly

    Barashenkov, V. S.; Buttsev, V. S.; Buttseva, G. L.; Dudarev, S. Ju.; Polanski, A.; Puzynin, I. V.; Sissakian, A. N.

    2000-07-01

    This paper presents the research program of the Experimental Accelerator Driven System (ADS), which employs a subcritical assembly and a 660 MeV proton accelerator operating in the Laboratory of Nuclear Problems at the Joint Institute for Nuclear Research in Dubna. Mixed-oxide (MOX) fuel (25% PuO2+75% UO2) designed for the BN-600 reactor use will be adopted for the core of the assembly. The present conceptual design of the experimental subcritical assembly is based on a core nominal unit capacity of 15 kW (thermal). This corresponds to the multiplication coefficient keff=0.945, energetic gain G=30, and accelerator beam power of 0.5 kW.

  1. Research Programme for the 660 Mev Proton Accelerator Driven MOX-Plutonium Subcritical Assembly

    Barashenkov, V S; Buttseva, G L; Dudarev, S Yu; Polanski, A; Puzynin, I V; Sissakian, A N

    2000-01-01

    The paper presents a research programme of the Experimental Acclerator Driven System (ADS), which employs a subcritical assembly and a 660 MeV proton acceletator operating at the Laboratory of Nuclear Problems of the JINR, Dubna. MOX fuel (25% PuO_2 + 75% UO_2) designed for the BN-600 reactor use will be adopted for the core of the assembly. The present conceptual design of the experimental subcritical assembly is based on a core of a nominal unit capacity of 15 kW (thermal). This corresponds to the multiplication coefficient k_eff = 0.945, energetic gain G = 30 and the accelerator beam power 0.5 kW.

  2. Mutation effect of MeV protons on bioflocculant bacteria Bacillus cereus

    A 3.2 MeV proton beam was used to irradiate bioflocculant bacteria (Bacillus cereus) to achieve mutation. The ion fluence ranged from 1011 to 1014/cm2. Most of the bacteria were killed when the ion fluence reached 1012 ions/cm2. The survival ratio drops in an exponential way on further increasing the ion fluence. The flocculating activity of 7 samples out of 51 showed a positive change, and a perfect mutant C7-23 with a stable high capacity of bioflocculant production was found. RAPD measurements showed that a new lane appears in this sample. The flocculating activity of the C7-23 bacteria increased by factors of 22%, 54% and 217% under pH values of 4, 7 or 10, respectively

  3. Mutation effect of MeV protons on bioflocculant bacteria Bacillus cereus

    Yang, Y. N.; Ren, N.; Xue, J. M.; Yang, J.; Rong, B. L.

    2007-09-01

    A 3.2 MeV proton beam was used to irradiate bioflocculant bacteria (Bacillus cereus) to achieve mutation. The ion fluence ranged from 1011 to 1014/cm2. Most of the bacteria were killed when the ion fluence reached 1012 ions/cm2. The survival ratio drops in an exponential way on further increasing the ion fluence. The flocculating activity of 7 samples out of 51 showed a positive change, and a perfect mutant C7-23 with a stable high capacity of bioflocculant production was found. RAPD measurements showed that a new lane appears in this sample. The flocculating activity of the C7-23 bacteria increased by factors of 22%, 54% and 217% under pH values of 4, 7 or 10, respectively.

  4. Beam dynamics design and electromagnetic analysis of 3 MeV RFQ for TAC Proton Linac

    A Caliskan; HF Kisoglu; M Yilmaz

    2015-01-01

    A beam dynamics design of 352.2 MHz radio-frequency quadrupole (RFQ) of Turkish Accelerator Cen-ter (TAC) project which accelerates continuous wave (CW) proton beam with 30 mA current from 50 keV to 3 MeV kinetic energy has been performed in this study. Also, it includes error analysis of the RFQ, in which some fluctuations have been introduced to input beam parameters to see how the output beam parameters are affected, two-dimensional (2-D) and three-dimensional (3-D) electromagnetic structural design of the RFQ to obtain optimum cavity paramaters that agree with the ones of the beam dynamics. The beam dynamics and error analysis of the RFQ have been done by using LIDOS.RFQ. Electromagnetic design parameters have been obtained by using SUPERFISH for 2-D cavity geometry and CST Microwave Studio for 3-D cavity geometry.

  5. Study on the microwave ion source of 100-MeV proton linac

    Kwon, Hyeok-Jung

    2016-01-01

    A microwave ion source is used as an ion source of 100-MeV proton accelerator at Korea Multipurpose Accelerator Complex (KOMAC). The specifications of the ion source are 50 keV in energy and 20 mA in peak current. The plasma is operated in CW mode using magnetron and the pulse beam is extracted using semiconductor switch located in the extraction power supply. The beam characteristics were measured based on the pulse voltage and current. A test stand was also installed to study the beam characteristics of the ion source in off-line. In this paper, the pulse beam characteristics of the ion source are presented and the installation of the test stand is reported.

  6. Radiative capture of polarized neutrons by polarized protons at Tn=183 MeV

    Xu, G.; Pate, S. F.; Bloch, C.; Vigdor, S. E.; Bowyer, S. M.; Bowyer, T. W.; Jacobs, W. W.; Meyer, H. O.; Pierce, E.; Sowinski, J.; Whiddon, C.; Wissink, S. W.; Jolivette, P. L.; Pickar, M. A.

    1995-12-01

    In order to provide a quantitative test of theoretical calculations incorporating meson-exchange currents and intermediate Δ resonances, we measure the normal-component spin correlation coefficient CNN, the differential cross section dσ/dΩ, and the neutron and proton analyzing powers An and Ap, each as a function of angle, for n-->p-->-->dγ at Tn=183 MeV. Our n-->p-->-->dγ results, combined with the previous cross section and photon asymmetry data collected in the past decade, place quite strong constraints on model calculations. Our data are in excellent agreement with theoretical predictions by Jaus and Woolcock that incorporate meson-exchange and isobar current effects and relativistic corrections, signifying great recent progress in our understanding of these effects in the nucleon-nucleon system.

  7. Activation cross sections of proton induced nuclear reactions on palladium up to 80MeV.

    Tárkányi, F; Ditrói, F; Takács, S; Csikai, J; Hermanne, A; Uddin, M S; Baba, M

    2016-08-01

    Activation cross sections of proton induced nuclear reactions on palladium were measured up to 80MeV by using the stacked foil irradiation technique and gamma ray spectrometry. The beam intensity, the incident energy and the energy degradation were controlled by a method based on flux constancy via normalization to the excitation functions of monitor reactions measured in parallel. Excitation functions for direct and cumulative cross-sections were measured for the production of (104m,104g,105g,106m,110m)Ag, (100,101)Pd, (99m,99g,100,101m,101g,102m,102g,105)Rh and (103,97)Ru radioisotopes. The cross section data were compared with the theoretical predictions of TENDL-2014 and -2015 libraries. For practical applications thick target yields were derived from the measured excitation functions. Application in the field of medical radionuclide production is shortly discussed. PMID:27235887

  8. Prompt γ-rays emitted in fission of 226Ra by 12 MeV protons

    The total energy associated with the emission of prompt γ-rays in fission of 226Ra induced by 12 MeV protons was measured in correlation with the fragment mass and kinetic energy. The dependence of the average total γ-ray energy on fragment mass and total kinetic energy resembles the corresponding dependence of the average number of neutrons. Using these results and the results for the average number of neutrons, the excitation energy of the fragments at the scission point was calculated. The results support the view that the scission-point configuration for the symmetric fission mode is more elongated than that for the asymmetric mode. (B.G.)

  9. Measurement of spectra of high-energy protons generated in the shielding of a 680 MeV synchrocyclotron

    Until very recently, no experimental information on spectra of high-energy protons generated in the shielding of accelerators has been available in the literature. Such information is necessary not only to establish the degree of radiation risk due to this field component, but also to check the methods of calculating the shielding and determining the degree of adequacy of the readings of dosimeters to the equivalent dose in the radiation fields behind the shielding of accelerators. The spectra of protons escaping from the shielding of the synchrocyclotron of the Laboratory of Nuclear Problems, Joint Institute for Nuclear Research, were measured along the normal to the shielding with a spectrometer constructed for proton spectra between 55 and 500 MeV. The measured spectra of protons emitted from shielding of the 680 MeV synchrocyclotron are presented

  10. A fully microscopic model of 200 MeV proton-12C elastic and inelastic scattering

    An effective two nucleon (NN) interaction in the nuclear medium is defined from an accurate mapping of the NN g matrices obtained by solving the Brueckner-Bethe-Goldstone equations for infinite nuclear matter. That effective interaction is used in a fully microscopic calculation of the nonlocal effective proton-12C interaction from which are obtained predictions of the differential cross section and analysing power for 200 MeV elastic scattering. The relative motion wave functions so found are used as the distorted waves in a distorted wave approximation (DWA) study of select inelastic scattering events. The effective NN interaction is used as the transition operator in those calculations. The relevant nuclear spectroscopy for the elastic and DWA (p, p') calculations is found from a full (0 + 2) ℎω shell model evaluation of the positive parity states while a restricted (1 + 3)ℎω has been used to give the negative parity states. Results are compared with those of the 0p-shell model of Cohen and Kurath or with those based upon axially symmetric, projected Hartree-Fock calculations. The diverse structure model wave functions are assessed by using them in calculations to compare with measured longitudinal, transverse electric and transverse magnetic form factors from electron scattering to many of the excited states of 12C. Using those models of the structure of 12C in the completely microscopic model of the elastic and inelastic scattering of 200 MeV protons, good fits have been found to the cross section and analysing power data. 50 refs., 3 tabs., 20 figs

  11. Quasifree Eta photoproduction on the proton and neutron of deuterium at photon energies up to 1150 MeV; Quasifreie Eta-Photoproduktion am Proton und Neutron des Deuteriums bei Photonenergien bis 1150 MeV

    Krebeck, M.

    1995-12-31

    The present thesis describes the performance of the measurement of the quasi-free eta photoproduction on the neutron and on the proton of the deuterium for photon energies from the eta production threshold up to 1150 MeV. The ratio of the cross sections on the neutron to the cross sections on the proton could be determined to {sigma}{sub n}/{sigma}{sub p}=0.728{+-}0.033. From this the isoscalar production amplitude, renormalized to the production amplitude on the proton, could be calculated with a value of 0.07{+-}0.01.

  12. Space charge dominated beam dynamics in 1 MeV compact proton cyclotron

    Compact high current cyclotrons to accelerate proton beams are still considered as favorable source for many applications such as isotope production, injector for high intensity cyclotron for ADSS etc. Data shows that existing commercial compact machines are limited to beam current below 1 m.A, With proper design and improved understanding of how to control the high intensity beam at low energy, it is possible to increase this current and accelerate beam of several mA's with minimum losses. The development of 1 MeV, 5 mA compact proton cyclotron at VECC is an R and D effort with the main aim to study and settle various technological and beam dynamics related problems during injection and acceleration of high intensity beams. The evolution of space charge dominated beam in a cyclotron is very complex due to the coupling between the transverse and longitudinal motions. For optimum performance, the input phase ellipses of the injected beam must be matched to the acceptance of the central region. The envelope mismatch is the major cause of emittance growth and halo formation. Thus it is important to study the evolution of space charge dominated beam during transport and acceleration in the cyclotron focusing channel to avoid beam loss

  13. 600 MeV Simulation of the Production of Cosmogenic Nuclides in Meteorites by Galactic Protons

    2002-01-01

    A large variety of stable and radioactive nuclides is produced by the interaction of solar and galactic cosmic rays with extraterrestrial matter. Measurements of such cosmogenic nuclides provide information about the constancy of cosmic ray fluxes in space and time and about the irradiation history of individual extraterrestrial objects provided that there exist reliable models describing the production process. For the calculation of the depth dependent production of cosmogenic nuclides in meteorites no satisfactory Therefore, the irradiation of small stony meteorites (radii~$<$~40~cm) by galactic protons is simulated in a series of thick target irradiation experiments at the 600~MeV proton beam of the SC. \\\\ \\\\ The thick targets are spheres (R = 5, 15, 25 cm) and are made out of diorite because of its low water content, its high density (3.0~g/cm|3) and because it provides a good approximation of the chemical composition of some common meteorite clas These spheres will also contain a wide variety of pure...

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

    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...

  15. Proton beam of 2 MeV 1.6 mA on a tandem accelerator with vacuum insulation

    A source of epithermal neutrons based on a tandem accelerator with vacuum insulation for boron neutron capture therapy of malignant tumors was proposed and constructed. Stationary proton beam with 2 MeV energy, 1.6 mA current, 0.1% energy monochromaticity and 0.5% current stability has just been obtained

  16. Stopping power of the elements Z=20 through Z=30 for 5-12-MeV protons and deuterons

    Andersen, Hans Henrik; Hanke, C.C.; Simonsen, H.; Sørensen, H.; Vajda, P.

    1968-01-01

    The stopping power for 5-12-MeV protons and deuterons of Ca, Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, and Zn has been measured. For most of the materials, the accuracy is ±0.3%. For Ca, Sc, Cr, and Mn, which were rather difficult to handle, the results are somewhat less accurate. The results have been...

  17. Quasifree Eta photoproduction on the proton and neutron of deuterium at photon energies up to 1150 MeV

    The present thesis describes the performance of the measurement of the quasi-free eta photoproduction on the neutron and on the proton of the deuterium for photon energies from the eta production threshold up to 1150 MeV. The ratio of the cross sections on the neutron to the cross sections on the proton could be determined to σn/σp=0.728±0.033. From this the isoscalar production amplitude, renormalized to the production amplitude on the proton, could be calculated with a value of 0.07±0.01

  18. Most probable charge of fission products in 24 MeV proton induced fission of 238U

    The charge distributions of fission products in 24 MeV proton-induced fission of 238U were measured by the use of an ion-guide isotope separator on line. The most probable charge (Zp) of the charge distribution was discussed in view of the charge polarization in the fission process. It was found that Zp mainly lies on the proton-rich side in the light mass region and on the proton-deficient side in the heavy mass region compared with the postulate of the unchanged charge distribution. The charge polarization was examined with respect to production Q values. copyright 1998 The American Physical Society

  19. Radiation tolerance of ultra-thin PIN silicon detectors evaluated with a MeV proton microbeam

    Abdel, Naseem S.; Pallon, Jan; Elfman, Mikael; Kristiansson, Per; Nilsson, E. J. Charlotta; Ros, Linus

    2015-08-01

    A focused MeV proton beam at the Lund Ion Beam Analysis Facility has been used to induce radiation damage in transmission semiconductor detectors. The damage alters the response of detectors and degrades their charge transport properties. In this work, the radiation tolerance of ultra-thin silicon PIN detectors was studied as a function of proton fluences and detector thickness using a scanning proton microprobe. The investigated detectors had thicknesses ranging between 6.5 and 22 μm, and different selected regions of each detector were irradiated with fluence up to 2 × 1015 protons/cm2. The results show that the charge collection efficiency (CCE) decreases as a function of the proton fluence. Compared with non-irradiated regions, the CCE was above 94% at the lowest fluence of 2 × 1012 protons/cm2 for all the detectors studied. Degradation of the devices caused spectral peak shifting toward lower energies. The highest possible fluence of 2.55 MeV protons that could be used, causing only minor radiation damage, was 2 × 1013 cm-2 for the thinnest detectors (6.5 and 10 μm) and 2 × 1012 cm-2 for the thickest detectors (15 and 22 μm).

  20. Development of the integrated control system for the microwave ion source of the PEFP 100-MeV proton accelerator

    Song, Young-Gi; Seol, Kyung-Tae; Jang, Ji-Ho; Kwon, Hyeok-Jung; Cho, Yong-Sub

    2012-07-01

    The Proton Engineering Frontier Project (PEFP) 20-MeV proton linear accelerator is currently operating at the Korea Atomic Energy Research Institute (KAERI). The ion source of the 100-MeV proton linac needs at least a 100-hour operation time. To meet the goal, we have developed a microwave ion source that uses no filament. For the ion source, a remote control system has been developed by using experimental physics and the industrial control system (EPICS) software framework. The control system consists of a versa module europa (VME) and EPICS-based embedded applications running on a VxWorks real-time operating system. The main purpose of the control system is to control and monitor the operational variables of the components remotely and to protect operators from radiation exposure and the components from critical problems during beam extraction. We successfully performed the operation test of the control system to confirm the degree of safety during the hardware performance.

  1. Biological response of arabidopsis seed to MeV proton irradiation at different region of its embryo

    The water saturated Arabidopsis seeds were irradiated with protons in air. The ion energy is from 1.1 MeV to 6.5 MeV. According to TRIM simulation, the damaged region of the seed induced by the incident ions is near the surface region of the embryo, half of the embryo and the whole embryo, respectively. The protons with high energy can damage the shoot apical meristem (SAM) in the embryo while the protons with low energy cannot. The ion fluence used in this experiment was in the range of 4 x 109 to 1 x 1014 ions/cm2. The experimental results showed that both the germination and survival rates decrease while increasing ion fluence, and the fluence-response curve for different damaged region of the embryo has different characters. Besides SAM, which is generally considered as the main radiobiological target, the existence of a secondary target besides SAM is proposed in this paper. (authors)

  2. Determination of Magnet Specification of 13 MeV Proton Cyclotron Based on Opera 3D

    Taufik

    2014-08-01

    Full Text Available The magnet is one of the main components of a cyclotron, used to form a circular particle beam trajectories and to provide focusing of the beam. To support the mastery of 13-MeV proton cyclotron technologies, cyclotron magnet design must be done to satisfy cyclotron magnet requirements. This research was conducted by studying important parameters in designing the cyclotron magnet which is then used to determine the design requirements. The magnet design was based on the results of a 3D simulation using Opera 3D software. Opera 3D is a software developed by Cobham plc to solve physical problems in 3D such as magnetostatic using finite element methods. The simulation started by drawing a 3D model of the magnet using a modeler, followed by magnetic field calculations by Tosca module in the Opera 3D software. Simulation results were analyzed with the Genspeo software to determine whether the parameters of the cyclotron magnet have met design requirements. The results indicate that the magnet design satisfied the cyclotron magnet design requirement, that B in the median plane of the magnetic pole approached the isochronous curve, providing axial and radial focusing beam, crossing the resonance line at vr = 1 when the particle energy is low and the particle energy is more than 13 MeV, and lead to small enough phase shift of about 13°. The dimension of the cyclotron magnet is 1.96 m × 1.30 m × 1.21 m; its weight is 17.3 ton; its coil current is 88,024 ampere-turn; its center magnetic field is 1.27479 T; its maximum magnetic field is 1.942116 T; its minimum magnetic field is 0.7689 T; its valley gap is 120 mm; its hill gaps are 40 to 50.78 mm; and its hill angles are 35° to 44°.to 44°

  3. Determination of Magnet Specification of 13 MeV Proton Cyclotron Based on Opera 3D

    The magnet is one of the main components of a cyclotron, used to form a circular particle beam trajectories and to provide focusing of the beam. To support the mastery of 13-MeV proton cyclotron technologies, cyclotron magnet design must be done to satisfy cyclotron magnet requirements. This research was conducted by studying important parameters in designing the cyclotron magnet which is then used to determine the design requirements. The magnet design was based on the results of a 3D simulation using Opera 3D software. Opera 3D is a software developed by Cobham plc to solve physical problems in 3D such as magnetostatic using finite element methods. The simulation started by drawing a 3D model of the magnet using a modeler, followed by magnetic field calculations by Tosca module in the Opera 3D software. Simulation results were analyzed with the Genspeo software to determine whether the parameters of the cyclotron magnet have met design requirements. The results indicate that the magnet design satisfied the cyclotron magnet design requirement, that B in the median plane of the magnetic pole approached the isochronous curve, providing axial and radial focusing beam, crossing the resonance line at vr = 1 when the particle energy is low and the particle energy is more than 13 MeV, and lead to small enough phase shift of about 13°. The dimension of the cyclotron magnet is 1.96 m × 1.30 m × 1.21 m; its weight is 17.3 ton; its coil current is 88,024 ampere-turn; its center magnetic field is 1.27479 T; its maximum magnetic field is 1.942116 T; its minimum magnetic field is 0.7689 T; its valley gap is 120 mm; its hill gaps are 40 to 50.78 mm; and its hill angles are 35° to 44°. (author)

  4. Search for the electron-positron decay of an axionlike particle from a 590 MeV proton beam dump

    A search was made for the decay of a light neutral particle into an e+e--pair behind the dump of the PSI (formerly SIN) 590 MeV proton beam. The detector consisted of two counter triggered optical spark chambers mounted two meters apart. A decay signal would have been detected within a cone of about 100 around the direction to the beam dump. For 300 coulomb of protons we found no excess of decay events over the background. Consequently we can exclude the existence of a standard axion for X-parameters between 13.6 and 300, equivalent to masses between 2me and 20 MeV. For the decay mode a0→e+e- the standard axion model predicts a decay rate Γee≅2x106 ma-1 MeV s-1 whereas our analysis yields a limit Γeea-1 MeV s-1 with 90% confidence. In the general case, e.g. for an axionlike boson χ0 we exclude values for the decay constant fχ4 GeV with 90% confidence for masses between 2 me and 20 MeV. (orig.)

  5. High intensity proton beam transportation through fringe field of 70 MeV compact cyclotron to beam line targets

    Zhang, Xu; Li, Ming; Wei, Sumin; Xing, Jiansheng; Hu, Yueming; Johnson, Richard R.; Piazza, Leandro; Ryjkov, Vladimir

    2016-06-01

    From the stripping points, the high intensity proton beam of a compact cyclotron travels through the fringe field area of the machine to the combination magnet. Starting from there the beams with various energy is transferred to the switching magnet for distribution to the beam line targets. In the design of the extraction and transport system for the compact proton cyclotron facilities, such as the 70 MeV in France and the 100 MeV in China, the space charge effect as the beam crosses the fringe field has not been previously considered; neither has the impact on transverse beam envelope coupled from the longitudinal direction. Those have been concerned much more with the higher beam-power because of the beam loss problem. In this paper, based on the mapping data of 70 MeV cyclotron including the fringe field by BEST Cyclotron Inc (BEST) and combination magnet field by China Institute of Atomic Energy (CIAE), the beam extraction and transport are investigated for the 70 MeV cyclotron used on the SPES project at Istituto Nazionale di Fisica Nucleare, Laboratori Nazionali di Legnaro (INFN-LNL). The study includes the space charge effect and longitudinal and transverse coupling mentioned above, as well as the matching of beam optics using the beam line for medical isotope production as an example. In addition, the designs of the ±45° switching magnets and the 60° bending magnet for the extracted beam with the energy from 35 MeV to 70 MeV have been made. Parts of the construction and field measurements of those magnets have been done as well. The current result shows that, the design considers the complexity of the compact cyclotron extraction area and fits the requirements of the extraction and transport for high intensity proton beam, especially at mA intensity levels.

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

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

    2014-01-21

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

  7. 15 MeV proton irradiation effects on Bi-based high temperature superconductors

    Nowadays, superconducting magnetic coils are used in some tokamaks such as EAST, KSTAR, JT-60, and T-15 to generate strong magnetic fields and also in ITER magnetic fields of about 13 tesla will be produced with the help of superconductors. The tokamak superconductors are exposed to the variety of radiations (neutron, ions beam, and gamma) from plasma nuclear reactions which will affect some of the superconductor properties. Therefore, study of the irradiation effects on the superconductor structure and properties are very crucial from technological and scientific point of view. One of the superconductor irradiation effects to be investigated under different conditions of energy and dosage is the potential resistance of the material used in tokamak reactor magnetic coils against activation by radiation. In this work, pellets of high Tc Bi-based superconductors have been prepared and after measurement of parameters, a sample of pellet has been irradiated with 15 MeV protons using Karaj cyclotron facility. The sample's parameters have been measured again after irradiation treatment. X-ray diffraction patterns and SEM images of the sample before and after irradiation treatment have been studied.

  8. Changes in the physical and chemical properties of Pvdf irradiated by 4 MeV protons

    The behavior of poly-vinylidene fluoride (Pvdf) under bombardment of different kinds of radiation is of interest due to the polymer's unique piezo-electric properties and various crystalline forms. In this work, Pvdf film samples of 0.3 mm thickness and density 1.76 g/cm3 were irradiated with 4 MeV protons from the Instituto de Fisica 9SDH-2 Pelletron Accelerator. Changes in the physical and chemical properties were investigated using Fourier Transform Infrared Spectroscopy (Ftir) with Atr, X-ray Diffraction (XRD), Differential Scanning Calorimetry (DSc) and gel fraction measurements. The gel percent increases with fluence to almost 60% for a fluence of 1013 cm-2, and then more slowly up to 100% for a fluence of 3 x 1014 cm-2. The DSc curve of the control sample shows a sharp band at 176 C with a shoulder on the low temperature side. A well defined lower temperature peak, related to the relaxation of inter-crystalline regions appears at a fluence of 1013 cm-2. At 3 x 1014 cm-2 there are no melting peaks, due to complete destruction of the crystalline structure. This was confirmed at this high fluence by the Ftir spectra, and by x-ray diffraction, where an amorphous structure was observed. (Author)

  9. 15 MeV proton irradiation effects on Bi-based high temperature superconductors

    Alinejad, N.; Sohrabi, D. [Nuclear Science and Technology Research Institute, Tehran (Iran, Islamic Republic of). Plasma and Nuclear Fusion Research School; Bolori, F. [Karaj Agricultural, Medical, and Industrial Research School, Karaj (Iran, Islamic Republic of)

    2015-11-15

    Nowadays, superconducting magnetic coils are used in some tokamaks such as EAST, KSTAR, JT-60, and T-15 to generate strong magnetic fields and also in ITER magnetic fields of about 13 tesla will be produced with the help of superconductors. The tokamak superconductors are exposed to the variety of radiations (neutron, ions beam, and gamma) from plasma nuclear reactions which will affect some of the superconductor properties. Therefore, study of the irradiation effects on the superconductor structure and properties are very crucial from technological and scientific point of view. One of the superconductor irradiation effects to be investigated under different conditions of energy and dosage is the potential resistance of the material used in tokamak reactor magnetic coils against activation by radiation. In this work, pellets of high T{sub c} Bi-based superconductors have been prepared and after measurement of parameters, a sample of pellet has been irradiated with 15 MeV protons using Karaj cyclotron facility. The sample's parameters have been measured again after irradiation treatment. X-ray diffraction patterns and SEM images of the sample before and after irradiation treatment have been studied.

  10. Growth of bubbles during annealing of 600 MeV proton irradiated aluminium

    High purity aluminium foils were irradiated with 600 MeV protons in the cyclotron of the Swiss Institute of Nuclear Research (SIN). In this type of irradiation, helium is produced by nuclear reactions simultaneously with displacement damage. The samples were studied by transmission electron microscopy (TEM) as irradiated and after successive isothermal anneals in vacuum. The bubble structure is found to be very stable, no growth being observed for annealing temperatures below 770 K (0.82 Tm, where Tm is the absolute melting temperature). In the present study, the annealings were performed at 900 K in a sample irradiated to 2.8 dpa at 450 K. Overall statistics were used to study the resulting bubble distributions, bubble diameters varying between 2.5 and 10 nm. Distributions obtained after annealing samples thinned for TEM observations are compared to those observed after annealing 75 μm thick irradiated samples, showing that the loss of information in the thinned sample is limited. Under these conditions it is discussed that the most probable growth mechanism is that of bubble coalescence, but it is not clear yet which is the operating diffusion mechanism. (orig.)

  11. Monte Carlo calculated stopping-power ratios, water/air, for clinical proton dosimetry (50-250 MeV)

    Calculations of stopping power ratios, water to air, for the determination of absorbed dose to water in clinical proton beams using ionization chamber measurements have been undertaken using the Monte Carlo method. A computer code to simulate the transport of protons in water (PETRA) has been used to calculate Sw,air-data under different degrees of complexity, ranging from values based on primary protons only to data including secondary electrons and high-energy secondary protons produced in nonelastic nuclear collisions. All numerical data are based on ICRU 49 proton stopping powers. Calculations using primary protons have been compared to the simple continuous slowing-down approximation (c.s.d.a.) analytical technique used in proton dosimetry protocols, not finding significant differences that justify elaborate Monte Carlo simulations except beyond the mean range of the protons (the far side of the Bragg peak). The influence of nuclear nonelastic processes, through the detailed generation and transport of secondary protons, on the calculated stopping-power ratios has been found to be negligible. The effect of alpha particles has also been analysed, finding differences smaller than 0.1% from the results excluding them. Discrepancies of up to 0.6% in the plateau region have been found, however, when the production and transport of secondary electrons are taken into account. The large influence of nonelastic nuclear interactions on proton depth-dose distributions shows that the removal of primary protons from the incident beam decreases the peak-to-plateau ratio by a large factor, up to 40% at 250 MeV. It is therefore emphasized that nonelastic nuclear reactions should be included in Monte Carlo simulations of proton beam depth-dose distributions. (author)

  12. Transition from asymmetric to symmetric fission in 45-69 MeV proton induced fission of 238U

    H. Noshad

    2007-03-01

    Full Text Available Thin targets of 238U were bombarded with 45, 55, 65 and 69 MeV protons at the Cyclotron and Radioisotope Center (CYRIC of Tohoku University in Japan. Gamma rays emitted from the fission products were recorded and analyzed by using gamma spectroscopy. Then, the cross sections for the formation of fission products, fragment mass distributions, and total fission cross sections were measured. Special care was taken to make this measurement precisely. The experimental results show that for 238U(p, f reaction at Ep > 65 MeV, the asymmetry component in the mass distribution is eliminated, and the symmetric fission remains the dominant fission mode.

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

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

    2016-01-15

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

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

    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.

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

    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 ...

  16. Commissioning of a compact laser-based proton beam line for high intensity bunches around 10Â MeV

    Busold, S.; Schumacher, D.; Deppert, O.; Brabetz, C.; Kroll, F.; Blažević, A.; Bagnoud, V.; Roth, M.

    2014-03-01

    We report on the first results of experiments with a new laser-based proton beam line at the GSI accelerator facility in Darmstadt. It delivers high current bunches at proton energies around 9.6 MeV, containing more than 109 particles in less than 10 ns and with tunable energy spread down to 2.7% (ΔE/E0 at FWHM). A target normal sheath acceleration stage serves as a proton source and a pulsed solenoid provides for beam collimation and energy selection. Finally a synchronous radio frequency (rf) field is applied via a rf cavity for energy compression at a synchronous phase of -90 deg. The proton bunch is characterized at the end of the very compact beam line, only 3 m behind the laser matter interaction point, which defines the particle source.

  17. Evaluation of inelastic hadronic processes for 250 MeV proton interactions in tissue and iron using GEANT4

    When high-energy protons interact in beam delivery systems and are stopped in patients, a fraction of beam will undergo nuclear interactions that release secondary particles, in particular, neutrons of different energies. The GEANT4 Monte Carlo Code was used to simulate the interaction of 250 MeV proton beam in tissue and iron to calculate the energy and angular distributions of generated protons, neutrons and photons, and thus provide H * (10), the ambient dose equivalent. A modular physics list by utilising electromagnetic interactions and hadronic interactions was constructed. Three different GEANT4 models that include the low-energy parameterization, binary cascade and pre-compound model with Bertini cascade for proton inelastic interactions were compared. The findings suggest that the models play critical roles in terms of secondary particle generation. Further benchmarks are necessary to select the best model predicting a realistic scenario. (authors)

  18. Injection and diffusive transport of suprathermal through energetic solar flare protons (35 keV to 20 MeV)

    Beeck, J.; Mason, G. M.; Hamilton, D. C.; Marsden, R. G.; Sanderson, T. R.

    1990-01-01

    Consideration is given to the injection and interplanetary propagation of low-energy protons caused by the solar particle event of July 20, 1981, in which flare protons in the range from 35 keV to 20 MeV were observed by instruments on ISEE 3. The observed time-intensity and time-anisotropy profiles were fitted over the entire energy range using a model based on the spherically symmetric Fokker-Plank equation, including convection, diffusion, and adiabatic deceleration. The results are used to discuss the behavior of the radial interplanetary diffusion coefficient and the scattering mean free path for protons. Also, evidence is found for diffusive coronal shock acceleration of protons during the event.

  19. Radiation tolerance of ultra-thin PIN silicon detectors evaluated with a MeV proton microbeam

    Abdel, Naseem S.; Pallon, Jan; Elfman, Mikael; Kristiansson, Per; Nilsson, E.J. Charlotta; Ros, Linus

    2015-08-01

    Highlights: • We investigated the radiation hardness of ultra-thin silicon detectors using a 2.55 MeV focused proton beam. The detectors had thicknesses ranging between 6.5 and 22 μm, and four different regions of each detector were irradiated with fluences up to 2 × 10{sup 15} protons/cm{sup 2}. • The fluence limit with almost no observable damage was at Ø = 2 × 10{sup 13} cm{sup −2} for detectors of 6.5 and 10 μm thickness and Ø = 2 × 10{sup 12} cm{sup −2} for detectors of 15 and 22 μm thickness. • As a comparison, the detectors can be used under constant fluence of 10{sup 5} protons/cm{sup 2} for a few months up to years with little risk of being damaged. - Abstract: A focused MeV proton beam at the Lund Ion Beam Analysis Facility has been used to induce radiation damage in transmission semiconductor detectors. The damage alters the response of detectors and degrades their charge transport properties. In this work, the radiation tolerance of ultra-thin silicon PIN detectors was studied as a function of proton fluences and detector thickness using a scanning proton microprobe. The investigated detectors had thicknesses ranging between 6.5 and 22 μm, and different selected regions of each detector were irradiated with fluence up to 2 × 10{sup 15} protons/cm{sup 2}. The results show that the charge collection efficiency (CCE) decreases as a function of the proton fluence. Compared with non-irradiated regions, the CCE was above 94% at the lowest fluence of 2 × 10{sup 12} protons/cm{sup 2} for all the detectors studied. Degradation of the devices caused spectral peak shifting toward lower energies. The highest possible fluence of 2.55 MeV protons that could be used, causing only minor radiation damage, was 2 × 10{sup 13} cm{sup −2} for the thinnest detectors (6.5 and 10 μm) and 2 × 10{sup 12} cm{sup −2} for the thickest detectors (15 and 22 μm)

  20. Study of comparative reliability of computer simulation codes in estimating the cross sections for intermediate-energy proton interactions with nuclei of ADT materials

    The experimental data obtained by the authors on the production cross sections of residual nuclei in the 100-2600 MeV proton interactions with 59Co, 63,65Cu, nat,206,207,208Pb, 209Bi nuclei (thin targets) and with natW nucleus (thick target) are compared with the results of predictive simulation by ten codes. The reliability of the codes is estimated by quantitative ranking separately for a few combinations of proton energies and target materials making allowance for different generation channels of residual product nuclei. Despite quite satisfactory results of comparing between the experimental and simulated data in some cases, none of the simulation codes can be considered to show the required degree of applicability to all of the reactions studied

  1. Investigation of efficient cross sections of 152 MeV proton polarization after elastic and inelastic scattering

    This research thesis first reports the polarization of protons scattered by the most excited levels of Carbon 12 between 15 and 24 MeV. After a description of the experimental set-up and of experimental methods, results are discussed. Despite important experimental difficulties (beam energy width too large with respect to level separation), results comply with theoretical predictions for known levels. More precise measurements are then performed by studying the polarization of protons inelastically scattered by the first levels of carbon 12

  2. Search for characteristics of preequilibrium protons emitted in Ar + Ag collisions at E/A = 27 MeV

    Protons emitted in coincidence with heavy residues have been measured, for the reaction 27 MeV per nucleon 40Ar + natAg. From the proton velocity spectra, an anisotropic component was extracted, which shows a broad angular distribution, and a mean velocity larger than the beam velocity. Multiplicities for this component are low, about 0.8, independent of the violence of the collision. For central collisions, selected via the higher heavy residue velocities, the velocity characteristics of the anisotropic component, seen in this case as a pure preequilibrium component, were compared to semi-classical calculations (Landau-Vlasov)

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

    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.

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

    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.

  5. Fission properties of actinide nuclei from proton-induced fission at 26.5 and 62.9 MeV incident proton energies

    Demetriou, P.; Keutgen, Thomas; Prieels, René; El Masri, Youssef

    2010-01-01

    Fission properties of proton-induced fission on Th232, Np237, U238, Pu239, and Am241 targets, measured at the Louvain-la-Neuve cyclotron facility at proton energies of 26.5 and 62.9 MeV, are compared with the predictions of the state-of-the-art nuclear reaction code talys. The code couples the multimodal random neck-rupture model with the pre-equilibrium exciton and statistical models to predict fission fragment mass yields, pre- and post-scission neutron multiplicities, and total fission cro...

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

    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.

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

    The 9 and 12 MeV proton irradiations of the Chinese CMOS Image Sensor in the fiuence range from 1x109 to 4xl010 cm-2and 1x109 to 2x1012 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 4x1010 and 2x1012 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. (authors)

  8. 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

    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.

  9. Transition from asymmetric to symmetric fission in 45-69 MeV proton induced fission of 238U

    H. Noshad

    2007-01-01

    Thin targets of 238U were bombarded with 45, 55, 65 and 69 MeV protons at the Cyclotron and Radioisotope Center (CYRIC) of Tohoku University in Japan. Gamma rays emitted from the fission products were recorded and analyzed by using gamma spectroscopy. Then, the cross sections for the formation of fission products, fragment mass distributions, and total fission cross sections were measured. Special care was taken to make this measurement precisely. The experimental results show that for 238U(p...

  10. Differential cross sections for pion charge exchange on the proton at 27.5 MeV

    We have measured pion single charge exchange differential cross sections on the proton at 27.5 MeV incident π- kinetic energy in the center of momentum angular range between 0 degree and 55 degree. The extracted cross sections are compared with predictions of the standard pion-nucleon partial wave analysis and found to be in excellent agreement. copyright 1998 The American Physical Society

  11. Study of higher excited states in 20Ne by inelastic scattering of 24.5MeV protons

    The angular distributions of the differential cross-sections for the inelastic scattering of 24.5MeV protons were measured for excited states up to 9.50MeV in 20Ne. Prior to the experiment, an excitation function was measured for incident proton energies between 23 and 26MeV to select a resonance-free region. Twenty cross-sections have been measured, generally with high precision and low statistical errors. Large variations have been found in the shapes of angular distributions for states having the same spins and parities. Some of the excited states were analyzed in the framework of the collective model using either vibrational or rotational model wave functions. Very good agreement with the cross sections of the K=0+ ground state band have been obtained using β2, β4 and β6 multipole deformations of +0.47, +0.28 and -010, respectively. There is definite evidence for a new state in 20Ne at 9.31MeV which we tentatively assign a J(π)=4+ state

  12. Measurement of omega, the energy required to create an ion pair, for 150-MeV protons in nitrogen and argon

    The purpose of this thesis is to provide a 1% measurement of omega, the energy required to produce an ion pair, for 150 MeV protons in various gases. Such a measurement should improve the accuracy of proton ionization chamber dosimetry at the Harvard Cyclotron Laboratory. Currently, no measurements of omega exist in the energy range of 30 to 150 MeV, and present ionization chamber dosimetry at the Cyclotron relies on average values of measurements at lower and higher energies (i.e. for E < 3 MeV and E = 340 MeV). Contrary to theoretical expectations, these low and high energy data differ by as much as 9% in some gases. The results of this investigation demonstrate that the existing high energy data is probably in error, and current proton ionization chamber dosimetry underestimates omega, and hence the proton dose, by 5%

  13. Reaction cross sections for protons on {sup 12}C, {sup 40}Ca, {sup 90}Zr and {sup 208}Pb at energies between 80 and 180 MeV

    Auce, A.; Ingemarsson, A.; Johansson, R. [and others

    2005-04-01

    Results of reaction cross section measurements on {sup 12}C, {sup 40}Ca, {sup 90}Zr and {sup 208}Pb at incident proton energies between 80 and 180 MeV and for {sup 58}Ni at 81 MeV are presented. The experimental procedure is described and the results are compared with earlier measurements and predictions using macroscopic and microscopic models.

  14. Measurement of the free neutron-proton analyzing power and spin transfer parameters in the charge exchange region at 790 MeV

    Ransome, R.D.

    1981-07-01

    The free neutron-proton analyzing power and the spin transfer parameters (K/sub NN/, K/sub SS/, K/sub SL/, and K/sub LL/) were measured at the Los Alamos Meson Physics Facility at 790 MeV between 165/sup 0/ and 180/sup 0/ center of mass. A 40% polarized neutron beam incident on a liquid hydrogen target was used. The recoil protons were momentum analyzed with a magnetic spectrometer to isolate elastic scatters. A large solid angle carbon polarimeter was used to measure the proton polarization. The measurements are the first at this energy and are in basic agreement with pre-existing phase shift solutions. The proton-carbon analyzing power was measured between 500 and 750 MeV. An empirical fit to the proton-carbon analyzing power between 100 and 750 MeV was done.

  15. Measurement of the free neutron-proton analyzing power and spin transfer parameters in the charge exchange region at 790 MeV

    The free neutron-proton analyzing power and the spin transfer parameters (K/sub NN/, K/sub SS/, K/sub SL/, and K/sub LL/) were measured at the Los Alamos Meson Physics Facility at 790 MeV between 1650 and 1800 center of mass. A 40% polarized neutron beam incident on a liquid hydrogen target was used. The recoil protons were momentum analyzed with a magnetic spectrometer to isolate elastic scatters. A large solid angle carbon polarimeter was used to measure the proton polarization. The measurements are the first at this energy and are in basic agreement with pre-existing phase shift solutions. The proton-carbon analyzing power was measured between 500 and 750 MeV. An empirical fit to the proton-carbon analyzing power between 100 and 750 MeV was done

  16. Electrophilic FLUORIDE-18 from AN 11 Mev Proton Cyclotron for Radiolabeling of Presynaptic Dopaminergic PET Tracers

    Sunderland, John Joseph

    1990-01-01

    The reliable production of (^{18 }F) F_2 from an 11 MeV proton cyclotron has been achieved through the implementation of two accelerator targets built to exploit the copious ^{18}O(p,n)^ {18}F cross-section. Yields of electrophilic (^{18}F) F_2 from the targets reached deciCurie levels with specific activities approaching 3 Ci/mmole with 75 minute irradiations at 10 muA. Higher specific activities are expected with longer bombardments and increased beam current. The targets, one nickel, the other with a gold -plated target chamber, have been tested for (^ {18}F) F_2 production efficiency under two bombardment protocols. An economic two-step protocol cryogenically reclaims the precious enriched ^{18}O_{2 } target material following ^ {18}F production, followed by a second (^{18}F) F_2 recovery irradiation of Kr + F_2 . Studies of target performance using this protocol under variable irradiation conditions suggest a five compartment model governing the in-target kinetics. Similarly, the (^{18}F) F_2 yields have been tested using a single irradiation protocol consisting of bombardment of ^{18}O_{2} + F _2. Theoretical descriptions of beam induced phenomena in the irradiated target are also presented. The behavior of these targets cannot be judged solely on the amount of reactive ^{18 }F which elutes from the target; successful radiochemical synthesis utilizing this ^ {18}F activity in a model reaction is the true test. Synthesis of 6- (^{18 }F) fluoro-L-DOPA (6-FD) by the fluoro-demercuration method of Luxen served this purpose, testing the eletrophilic (^{18}F) F_2 gas from the two targets and two irradiation protocols. Elution of Kr + (^{18}F) F _2 from the two-step method achieved the expected 12% radiochemical yields from (^ {18}F) F_2, while experience with ^{18}F activity eluted with oxygen from the single irradiation protocol suffered lower yields. Solutions to problems associated with 6-FD studies for Positron Emission Tomography (PET) are addressed. A

  17. Properties of the First 1/2+ Excitation State of 13C by 22MeV Proton Inelastic Scattering

    安竹; 陈泉; 程业浩; 沈东军; 郭刚

    2003-01-01

    The differential cross sections of 22 MeV proton inelastic scattering for the first 1/2+ excitation state (Ex =3.09 MeV) of 13C have been measured between 9°and 130°. The broad peak located at~120°, which has beensystematically observed in the 0+ → 0-, 1/2- + 1/2+, and 1+ → 1- transitions for the 16O, 13C, and 14,15N (p, n)charge exchange reactions at Ep = 35 MeV, has been observed for the first time in the present proton inelasticscattering. The present experimental data are analysed by using microscopic distorted-wave Born approximation.From the comparison of present experimental data and theoretical results at forward angles, our analysis indicatesthe existence of neutron halo in the first 1/2+ excitation state of the 13C nucleus. In addition, by reasonablemodification of shell model wavefunction of the first 1/2+ excitation state, we can well describe the experimentalform factors of (e, e') and the experimental differential cross sections of (p, p') at incident energy of 547 Me V.

  18. Inclusive proton production cross sections in (d,xp) reactions induced by 100 MeV deuterons

    Energy spectra and angular distributions of protons emitted from the inclusive (d, xp) reaction on 9Be, 12C, 27Al,58Ni, 93Nb, 181Ta, 208Pb, and 238U were measured at an incident deuteron energy of 100 MeV. The protons were detected at laboratory scattering angles of 6 deg. to 120 deg. and 8 deg. to 120 deg. for the targets with 9 ≤ A ≤ 27 and A ≤ 58, respectively. Two triple-element and three double-element detector telescopes allowed for a low energy detection threshold of 4 to 8 MeV. The experimental results are presented in double differential as well as angle and energy-integrated cross sections. For all the nuclei studied, the energy spectra at forward angles show pronounced deuteron breakup peaks centered around approximately half of the incident deuteron energy. Qualitatively the energy spectra are similar for all nuclei at a given angle except in the region of the low-energy evaporation peak. As a function of target mass the evaporation cross sections are found to increase up to A = 58 after which they decrease again. The total pre-equilibrium proton cross section is roughly (280 ± 60) A1/3 mb. The angular distributions at the high emission energies are strongly forward peaked while the distributions of the low energy protons are almost isotropic. The LAHET Code System (LCS) was applied to calculate the proton production cross sections. Standard LCS calculations are found to underpredict the experimental cross sections at the very forward angles on the heavy target nuclei (A ≅ 58). By adding incoherently the Coulomb breakup cross section of the deuteron to the LCS calculations the experimental cross sections are reproduced to within 10%. Although pre-equilibrium processes are a necessary ingredient in the LCS calculations of the large-angle cross sections, this code still fails to predict the experimental evaporation distributions. (author)

  19. The irradiation creep of nickel and AISI 321 stainless steel during 4 MeV proton bombardment

    An apparatus has been developed to study the creep of thin metal specimens under tensile stress during bombardment by 4 MeV protons from the Harwell Van de Graaff Accelerator. The specimen is held in a helium atmosphere and the proton beam reaches it through a thin metal window at the end of the accelerator beam line. The proton beam passes through the thin (25 μm) specimen, losing approximately 1.5MeV in the process (most of which contributes to heating the specimen) and creating almost uniform radiation damage at the rate of (1-10)x10-7 displacements per atom per second (dpa s-1). The specimen temperature is monitored by infra-red pyrometry and controlled to +-0.20C by additional DC heating via the infra-red pyrometer output to compensate for ion beam fluctuations. The irradiation creep strain of the specimen is continuously measured with a sensitivity of 5x10-6 by a linear variable differential transformer. Irradiation times up to about 100h with reasonable beam stability are possible. Results are presented of the irradiation creep behavior of pure Ni and both solution treated and cold-worked AISI 321 stainless steel bombarded in the temperature range 400-6000C under tensile stresses in the range 20-250 MPa

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

    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...

  1. Dosimetric characterization of a synthetic single crystal diamond detector in a clinical 62 MeV ocular therapy proton beam

    Marinelli, Marco; Pompili, F. [INFN-Dipartimento di Ingegneria Industriale, Università di Roma “Tor Vergata”, Via del Politecnico 1, I-00133 Roma (Italy); Prestopino, G., E-mail: giuseppe.prestopino@uniroma2.it [INFN-Dipartimento di Ingegneria Industriale, Università di Roma “Tor Vergata”, Via del Politecnico 1, I-00133 Roma (Italy); Verona, C.; Verona-Rinati, G. [INFN-Dipartimento di Ingegneria Industriale, Università di Roma “Tor Vergata”, Via del Politecnico 1, I-00133 Roma (Italy); Cirrone, G.A.P.; Cuttone, G.; La Rosa, R.M.; Raffaele, L.; Romano, F. [Laboratori Nazionali del SUD, INFN, Catania (Italy); Tuvè, C. [INFN Sezione di Catania and Dipartimento di Fisica e Astronomia, Università di Catania, Catania (Italy)

    2014-12-11

    A synthetic single crystal diamond based Schottky photodiode was tested at INFN-LNS on the proton beam line (62 MeV) dedicated to the radiation treatment of ocular disease. The diamond detector response was studied in terms of pre-irradiation dose, linearity with dose and dose rate, and angular dependence. Depth dose curves were measured for the 62 MeV pristine proton beam and for three unmodulated range-shifted proton beams; furthermore, the spread-out Bragg peak was measured for a modulated therapeutic proton beam. Beam parameters, recommended by the ICRU report 78, were evaluated to analyze depth-dose curves from diamond detector. Measured dose distributions were compared with the corresponding dose distributions acquired with reference plane-parallel ionization chambers. Field size dependence of the output factor (dose per monitor unit) in a therapeutic modulated proton beam was measured with the diamond detector over the range of ocular proton therapy collimator diameters (5–30 mm). Output factors measured with the diamond detector were compared to the ones by a Markus ionization chamber, a Scanditronix Hi-p Si stereotactic diode and a radiochromic EBT2 film. Signal stability within 0.5% was demonstrated for the diamond detector with no need of any pre-irradiation dose. Dose and dose rate dependence of the diamond response was measured: deviations from linearity resulted to be within ±0.5% over the investigated ranges of 0.5–40.0 Gy and 0.3–30.0 Gy/min respectively. Output factors from diamond detector measured with the smallest collimator (5 mm in diameter) showed a maximum deviation of about 3% with respect to the high resolution radiochromic EBT2 film. Depth-dose curves measured by diamond for unmodulated and modulated beams were in good agreement with those from the reference plane-parallel Markus chamber, with relative differences lower than ±1% in peak-to-plateau ratios, well within experimental uncertainties. A 2.5% variation in diamond detector

  2. Design of 7 MeV drift tube linac as injector of proton accelerator for cancer therapy

    A 324 MHz drift-tube linac(DTL) is designed for proton cancer therapy. The design demands low power dissipation and short tank. The DTL accelerates beam from 2.5 MeV to 7 MeV, with RF power of 265 kW and total length of 1.9 m. The DTL uses permanent-quadrupole magnet(PQM) inside the drift tubes arranged in an FODO lattice. A new matching method is designed. In stead of the traditional beam transport line, the first four cells in DTL are designed as matching section. It causes the beam ellipse from radio-frequency quadrupole linac(RFQ) to satisfy conditions specified by the DTL periodic structure. The dynamics simulation was performed with PARMILA, and almost no emittance growth has been found. (authors)

  3. Radiochemical studies on the neutron- and proton-induced 7Be emission at energies up to 100 MeV

    Cross sections for 7Be emission in neutron and proton induced reaction on medium and heavy mass nuclei were measured up to 100 MeV using the activation method, radiochemical separations and γ-ray spectroscopy. For this purpose chemical separations were developed and modified to optain 7Be in a radiochemically pure form. In this work the excitation functions of (p,7Be) reactions on the target nuclei V, Nb, Au and Bi could be measured radiochemically for the first time in the energy range of 35 to 100 MeV. The cross sections for gold amount to a few μb, for vanadium to several tens of μb and for niobium to several hundred μb. (orig./HSI)

  4. Gas accumulation at grain boundaries during 800 MeV proton irradiation of aluminium and aluminium-alloys

    Singh, Bachu Narain; Horsewell, Andy; Sommer, W. F.;

    1986-01-01

    Samples of pure aluminium (99.9999%) and commercial Al-2.7%Mg(AlMg3) and Al-1.1%Mg-0.5%Si(Al6061) alloys were irradiated with 800 MeV protons at the Los Alamos Meson Physics Facility (LAMPF) at a temperature between 40-100°C to a maximum dose of 0.2 dpa. Transmission electron microscopy (TEM) sho...... higher than in the pure Al. The amount of gas accumulation at grain boundaries was found to depend on gas generation rate, alloying and cold-work microstructure...

  5. Evaluation of neutron and proton nuclear data of 28Si for energies up to 200 MeV

    The neutron and proton nuclear data of 28Si up to 200 MeV are evaluated for various nuclear engineering applications. The soft rotator model and the coupled-channel method are used to perform a consistent analysis of the collective band structure of 28Si and nucleon scattering from 28Si. The GNASH nuclear model code is used for compound and preequilibrium particle emission calculations, where the emission of 3He is also included. Comparisons show overall good agreement with various experimental data. (author)

  6. Annealing study of oxygenated and non-oxygenated float zone silicon irradiated with 15 MeV protons

    Härkönen, J; Heikkilä, P; Kallijärvi, S; Laitinen, P; Lassila-Perini, K M; Nummela, S; Nysten, J; Ovchinnikov, V; Palmu, L; Pirojenko, A; Riihimaki, I; Tuominen, E; Tuovinen, E; Ylikoski, M

    2003-01-01

    Introducing oxygen into the silicon material is believed to improve the radiation hardness of silicon detectors. In this study, oxygenated and non-oxygenated silicon samples were processed and irradiated with 15 MeV protons. In order to speed up the defect reactions after the exposure to particle radiation, the samples were heat treated at elevated temperatures. In this way, the long-term stability of silicon detectors in hostile radiation environment could be estimated. Current-voltage measurements and Surface Photovoltage (SPV) method were used to characterize the samples.

  7. Measurement of the Time-Structure of the 72 MeV Proton Beam in the PSI Injector-2 Cyclotron

    Dölling, R

    2001-01-01

    The time-structure monitor at the last turn of the 72MeV Injector-2 cyclotron has been improved in order to meet the stringent time-resolution requirement imposed by the short bunch length. Protons scattered by a thin carbon-fibre target pass through a first scintillator-photomultiplier detector and are stopped in a second one. The longitudinal bunch shape is given by the distribution of arrival times measured with respect to the 50 MHz reference signal from the acceleration cavities. From a coincidence measurement, the time resolution of the detectors has been determined to be 51 ps and 31 ps fwhm. Longitudinal and horizontal bunch shapes have been measured at beam currents from 25μA to 1700μA. Approximately circular bunches were observed with diameter increasing with current. The shortest observed proton bunch length was 38 ps fwhm.

  8. Spin polarized induction of quantum correlations_entanglement using a 2 MeV proton beam channeling

    Berec, Vesna

    2013-01-01

    In solid_state hybrid electron_nuclear spin systems quantum entanglement plays vital role in allowing accessible transfer of information between subatomic particles, regardless of the host lattice coordination spatial geometry, revealing the powerful resource for nuclear quantum states engineering. Here we present study of 2 MeV superfocused channeled proton (SCP) beam induced polarization of atom_photon correlated states, established in isotopically purified silicon nanocrystal. Two level entangling interaction which couples an initial quantum state to two possible light_matter states via silicon nanocrystal interface is presented. The anisotropic hyperfine coupling is demonstrated by strong mixing of quantum states within the control mechanism of the coherent proton pulse sequence. Obtained results reveal the mutual predictable correlation of particles of energy_matter, by using the fully broadcastable and precise hybrid electron_nuclear spin qubit manipulations which can be exploited for the speed_superior...

  9. Application of a PAGAT/MgCl2 gel for dose measurements in a 150 MeV proton beam

    The purpose of this study is to evaluate the dose response of polyacrylamide-based gel (PAGAT) when irradiated with clinical proton beams. Recently inorganic salt additive in gel has been reported to improve dose sensitivity substantially. We attempted to add MgCl2 (0.5M) to regular PAGAT gel in order to compensate its lower radiation sensitivity. The spin-spin relaxation rates (R2) as dose readout was calculated from MR imaging after irradiation with 150MeV proton beam. The dose sensitivity was discussed from the slope at dose-R2 response curve. As the result, the sensitivity of the gel with MgCl2 is approximately 3 times higher than that of regular PAGAT gel without spoiling dose response stability under the various irradiation conditions such as dose rate and dose integration.

  10. Application of a PAGAT/MgCl2 gel for dose measurements in a 150 MeV proton beam

    Tominaga, T.; Hayashi, S.; Usui, S.; Kawamura, H.; Katahira, K.

    2013-06-01

    The purpose of this study is to evaluate the dose response of polyacrylamide-based gel (PAGAT) when irradiated with clinical proton beams. Recently inorganic salt additive in gel has been reported to improve dose sensitivity substantially. We attempted to add MgCl2 (0.5M) to regular PAGAT gel in order to compensate its lower radiation sensitivity. The spin-spin relaxation rates (R2) as dose readout was calculated from MR imaging after irradiation with 150MeV proton beam. The dose sensitivity was discussed from the slope at dose-R2 response curve. As the result, the sensitivity of the gel with MgCl2 is approximately 3 times higher than that of regular PAGAT gel without spoiling dose response stability under the various irradiation conditions such as dose rate and dose integration.

  11. Fully microscopic model analyses of the elastic scattering of 200 MeV protons from targets of diverse mass

    Nonlocal optical potentials for the scattering of 200 MeV protons from 22 nuclei, ranging in mass from 6Li to 208Pb, have been identified by folding a complex, medium dependent effective interaction with density matrix elements of each target. The effective interaction is based upon solutions of the Lippmann-Schwinger and Brueckner-Bethe-Goldstone equations having the paris potential as input. The bound state single particle wave functions that specify the nuclear density matrices are Woods-Saxon functions for A≤12 but harmonic oscillator functions thereafter. The Wood-Saxon potential parameters and harmonic oscillator lengths were determined from fits made to the elastic electron scattering form factors for the low mass nuclei (A≤ 20) and by finding our best fits to the proton scattering data for the nuclei of heavier mass. The resulting differential cross sections, analyzing powers and spin rotations all compare well with the known data. 38 refs., 2 tabs., 12 figs

  12. The first SEPServer event catalogue ~68-MeV solar proton events observed at 1 AU in 1996–2010

    Rodríguez-Gasén Rosa

    2013-03-01

    Full Text Available SEPServer is a three-year collaborative project funded by the seventh framework programme (FP7-SPACE of the European Union. The objective of the project is to provide access to state-of-the-art observations and analysis tools for the scientific community on solar energetic particle (SEP events and related electromagnetic (EM emissions. The project will eventually lead to better understanding of the particle acceleration and transport processes at the Sun and in the inner heliosphere. These processes lead to SEP events that form one of the key elements of space weather. In this paper we present the first results from the systematic analysis work performed on the following datasets: SOHO/ERNE, SOHO/EPHIN, ACE/EPAM, Wind/WAVES and GOES X-rays. A catalogue of SEP events at 1 AU, with complete coverage over solar cycle 23, based on high-energy (~68-MeV protons from SOHO/ERNE and electron recordings of the events by SOHO/EPHIN and ACE/EPAM are presented. A total of 115 energetic particle events have been identified and analysed using velocity dispersion analysis (VDA for protons and time-shifting analysis (TSA for electrons and protons in order to infer the SEP release times at the Sun. EM observations during the times of the SEP event onset have been gathered and compared to the release time estimates of particles. Data from those events that occurred during the European day-time, i.e., those that also have observations from ground-based observatories included in SEPServer, are listed and a preliminary analysis of their associations is presented. We find that VDA results for protons can be a useful tool for the analysis of proton release times, but if the derived proton path length is out of a range of 1 AU < s ≲ 3 AU, the result of the analysis may be compromised, as indicated by the anti-correlation of the derived path length and release time delay from the associated X-ray flare. The average path length derived from VDA is about 1.9 times

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

    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 of the Bragg peak. Longitudinal charge distributions computed with FLUKA with both approaches have been compared with experimental data from the literature. Moreover, the contribution of different processes to the measurable signal has been addressed. A thorough analysis of the results has demonstrated that the nuclear and electromagnetic models of FLUKA reproduce the two sets of experimental data reasonably well.

  14. Design of a 10 MeV normal conducting CW proton linac based on equidistant multi-gap CH cavities

    Li, Zhihui

    2014-01-01

    The continue wave (CW) high current proton linac has wide applications as the front end of the high power proton machines. The low energy part is the most difficult one and there is no widely accepted solution yet. Based on the analysis of the focusing properties of the CW low energy proton linac, a 10 MeV low energy normal conducting proton linac based on equidistant seven-gap Cross-bar H-type (CH) cavities is proposed. The linac is composed of ten 7-gap CH cavities and the transverse focusing is maintained by the quadrupole doublets located between cavities. The total length of the linac is less than 6 meters and the average acceleration gradient is about 1.2 MeV/m. The electromagnetic properties of the cavities are investigated by Microwave Studio. At the nominal acceleration gradient the maximum surface electric field in the cavities is less than 1.3 times Kilpatrick limit, and the Ohmic loss of each cavity is less than 35 kW. The multi-particle beam dynamics simulations are performed with the help of the...

  15. Variations in the Processing of DNA Double-Strand Breaks Along 60-MeV Therapeutic Proton Beams

    Chaudhary, Pankaj; Marshall, Thomas I.; Currell, Frederick J.; Kacperek, Andrzej; Schettino, Giuseppe; Prise, Kevin M.

    2016-01-01

    Purpose To investigate the variations in induction and repair of DNA damage along the proton path, after a previous report on the increasing biological effectiveness along clinically modulated 60-MeV proton beams. Methods and Materials Human skin fibroblast (AG01522) cells were irradiated along a monoenergetic and a modulated spread-out Bragg peak (SOBP) proton beam used for treating ocular melanoma at the Douglas Cyclotron, Clatterbridge Centre for Oncology, Wirral, Liverpool, United Kingdom. The DNA damage response was studied using the 53BP1 foci formation assay. The linear energy transfer (LET) dependence was studied by irradiating the cells at depths corresponding to entrance, proximal, middle, and distal positions of SOBP and the entrance and peak position for the pristine beam. Results A significant amount of persistent foci was observed at the distal end of the SOBP, suggesting complex residual DNA double-strand break damage induction corresponding to the highest LET values achievable by modulated proton beams. Unlike the directly irradiated, medium-sharing bystander cells did not show any significant increase in residual foci. Conclusions The DNA damage response along the proton beam path was similar to the response of X rays, confirming the low-LET quality of the proton exposure. However, at the distal end of SOBP our data indicate an increased complexity of DNA lesions and slower repair kinetics. A lack of significant induction of 53BP1 foci in the bystander cells suggests a minor role of cell signaling for DNA damage under these conditions. PMID:26452569

  16. Longitudinal emittance measurement of the 100 MeV proton beam

    The results of the longitudinal emittance measurements carried out at the exit of the DTL part (100 MeV) of the 600 MeV Moscow meson emittance is determined from the bunch length measurements carried out at the exit of the last DTL cavity for three different and well known values of the accelerating field amplitudes. A Bunch length is measured by means of the bunch shape monitor with the phase resolution better than 1 degree at the DTL rf frequency. The results of the emittance measurements are used for a beam longitudinal matching between the DTL and the DAW parts of the linac

  17. Activation cross-sections of proton induced reactions on natSm up to 65 MeV

    Highlights: •Proton induced reactions on natural samarium up to 65 MeV. •Stacked foil irradiation technique. •Comparison of experimental results with the ALICE, EMPIRE and TALYS theoretical model codes. •Calculation and comparison of thick target integral yields. -- Abstract: Activation cross sections for proton induced reactions on Sm are presented for the first time for natSm(p,xn)154,152m2,152m1,152g,150m,150g,149,148,147,146,145Eu, natSm(p,x)153,145Sm, natSm(p,x)151,150,149,148g,148m,146,144,143Pm and natSm(p,x)141Nd up to 65 MeV. The cross sections were measured via activation method by using a stacked-foil irradiation technique and high resolution gamma ray spectroscopy. The results were compared with results of the nuclear reaction codes ALICE, EMPIRE and TALYS (results taken from TENDL libraries). Integral yields of the activation products were calculated from the excitation functions

  18. Activation cross-sections of proton induced reactions on natural Ni up to 65 MeV

    Production cross-sections of the natNi(p,x)60,61Cu, 56,57Ni, 55,56,57,58Co nuclear reactions were measured in five experiments up to 65 MeV by using a stacked foil activation technique. The results were compared with the available literature values, predictions of the nuclear reaction model codes ALICE-IPPE, TALYS-1.4, and extracted data from the TENDL-2012 library. Spline fits were made on the basis of selected data, from which physical yields were calculated and compared with the literature values. The applicability of the natNi(p,x)57Ni, 57Co reactions for thin layer activation (TLA) was investigated. The production rate for 55Co was compared for proton and deuteron induced reactions on Ni. - Highlights: • Production cross-sections of natNi(p,x)60,61Cu, 56,57Ni, 55,56,57,58Co reactions up to 65 MeV. • Comparison of results with theoretical codes ALICE-IPPE, TALYS 1.4 and TENDL-2012 library. • Calculation and comparison of physical yields with literature experiments. • Thin layer activation (TLA) curves for57Ni and 57Co for industrial applications. • The production rate for 55Co was compared for proton and deuteron induced reactions on Ni

  19. Proton LINAC Using Spiral Wave-guide with Finite Energy of 80 MeV

    Dolya, S N

    2016-01-01

    The article considers an opportunity of simultaneous pulsed acceleration of seven proton beams with current one hundred milliamps in each beam. The accelerator consists of two parts. In the first part of the accelerator having the length five meters, the protons are accelerated to the energy of mega electron Volts. Consumption of high-frequency power by this part of the accelerator is equal to mega Watts. In the second part of the accelerator having the length fifty meters, the protons are accelerated to the finite energy eighty mega electron Volts. Consumption of the high frequency power by the second part of the accelerator is seventy fours mega Watts. The radial focus of the proton beam in the first and second parts of the accelerator is carried out with the magnetic field ten Tesla which is generated by a superconducting solenoid.

  20. Neutron-proton elastic scattering between 200 and 500 MeV - 3. Phase shift analysis

    Data on Dsub(t), Rsub(t), Asub(t) and P from TRIUMF lead to unique and accurate np phase shift solutions at 210, 325, 425 and 515 MeV. The I = 0 D and G waves show large systematic deviations from current theoretical models. (author)

  1. Carbon fragmentation data from 37 and 40 MeV proton bombardment

    Eperimenta results reported are obtained in the study of fragmentation reactions induced by 37 and 40 MeV on Carbon. Cross sections obtained are shown. Details of experimental method are also given. No attempt is made to analyse the results in the framework of nuclear models and reaction mechanism, due to the fact that these studies are in progress up to now

  2. Characterization of radiation damage caused by 23 MeV protons in Multi-Pixel Photon Counter (MPPC)

    Li, Zhengwei; Xu, Yupeng; Liu, Congzhan; Gu, Yudong; Xie, Fei; Li, Yanguo; Hu, Hongliang; Zhou, Xu; Lu, Xuefeng; Li, Xufang; Zhang, Shuo; Chang, Zhi; Zhang, Juan; Xu, Zhenling; Zhang, Yifei; Zhao, Jianling

    2016-06-01

    A automatic gain control system (AGC) is designed to continuously monitor and automatically control the gain of the phoswich detectors onboard the Hard X-ray Modulation Telescope (HXMT). It consists of a Am241 radioactive source and a photo-detector. The Am241 radioactive source is tagged within a plastic scintillator (BC440M). The scintillating photons produced by the decayed alpha particles from the radioactive source is readout by the photo-detector. The Multi-Pixel Photon Counter (MPPC) produced by Hamamatsu is used as the photo-detector for AGC. To verify the feasibility of its application in space environment, four MPPCs (S10362-33-050C) were irradiated by a beam of 23 MeV protons. The integrated proton fluence that exposed to the four MPPC samples are 1.0 ×108 p cm-2 , 2.0 ×108 p cm-2 , 4.0 ×108 p cm-2 and 1.0 ×1010 p cm-2 respectively. It is found that the increment leakage current of the MPPC samples caused by irradiation damage increase linearly with the integrated fluence. The pulse-height resolution of the MPPC has deteriorated hardly after irradiation. When irradiated up to 1.1 ×109cm-2 1 MeV equivalent neutrons, the MPPC completely lost its photon-counting capability but could still work as a photo-detector for AGC. The MPPC fails as a photo-detector for the AGC when the irradiated 1 MeV neutron equivalent fluences is up to 2.7 ×1010cm-2 .

  3. Correlation on LET-measurements using TLDs with biological effects in a proton beam of 62 MeV

    A method based on TLDs was developed which enables the measurement of the absorbed dose as well as the determination of the average LET of mixed radiation fields. This method was successfully applied in space and in aircrafts and was used to measure the absorbed dose and the LET in proton beams. Stacks of dosemeters were exposed to a modulated as well as to an unmodulated proton beam (Bragg peak) of 62 MeV protons at the Paul Scherrer Institute, Switzerland. The irradiation in the unmodulated proton beam was used to calibrated the dosemeters. The increase of HTR with increasing LET was determined. This calibration was used to measure the LET in dependence of the depth of the modulated proton beam. The modulated proton beam is usually used in proton therapy modulated over the depth of the tumor. The advantage of this technique is a constant dose over the region of modulation. Nevertheless prior measurements of the RBE have shown an increase with increasing absorber thickness. This increase of RBE was verified with the HTR-method. An increase of the HTR respectively of the LET was measured in dependence of the proton range. Furthermore a comparison of the HTR with the survival propability of V79 irradiated in the modulated beam show a good agreement. The LET measured with TLDs increases from 1.78 keV/μm to 4.83 keV/μm tissue for 30 mGy absorbed dose, the survival propability decreases from 66.5% (1.4 mm depth) to 42.8% (28.6 mm) for 2 Gy absorbed dose. In addition to these measurements biological investigations with lymphocytes were performed irradiating TLDs and lymphocytes in a polyethylene phantom at two depths (5 mm and 20 mm absorber). For each position a dose characteristic was obtained from 0.25 to 2.0 Gy. The genotoxic essay was micronuclei. The analysis of the HTR-method show an increase of HTR of 30% from position 1 to position 2, considering that the absolute values depend on the absorbed dose. (author)

  4. Design study of Be-target for proton accelerator based neutron source with 13MeV cyclotron

    There is a cyclotron named KIRAMS-13 in Pusan National University, Busan, Korea, which has the proton energy of 13MeV and the beam current of 0.05mA. Originally, it was developed for producing medical radioisotopes and nuclear physics research. To improve the utilization of the facility, we are considering the possibilities of installing a neutron generation target in it. The Beryllium target has been considered and neutrons can be generated by 9Be(p,n)9B reaction above the threshold proton energy of 2.057MeV. In this presentation, we suggest candidate materials and structures, thicknesses, metal layers and cooling systems of target, which is optimal for the KIRAMS-13. We chose the Beryllium material of 1.14mm thick, which is calculated by stopping power of Beryllium, based on PSTAR, NIST. As for the cooling system, we chose to use water as a coolant, which will also act as a moderator. As protons pass through the target, hydrogen ions continue to pile up in the material and this makes the material brittle. To solve this problem, we chose Vanadium material because it has high hydrogen diffusion coefficient and short half-life isotope after being activated by neutrons. We simulated the neutron characteristics by the Monte Carlo simulation code, Geant4, CERN and performed thermal analysis on the target. The design of target system is very important to produce neutrons for the desired purposes. There are several other existing facilities in Korea, in addition to the cyclotron facility considered in this study, where new neutron target system can be installed and neutrons can be generated. Two prominent facilities are KOMAC, Gyeongju and RFT-30, Jeongeup and we are planning to do study on the possibilities of utilizing the accelerators for neutron generation.

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

    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...

  6. Analysing powers and spin correlations in deuteron–proton charge exchange at 726 MeV

    S. Dymov

    2015-05-01

    Full Text Available The charge exchange of vector polarised deuterons on a polarised hydrogen target has been studied in a high statistics experiment at the COSY-ANKE facility at a deuteron beam energy of Td=726 MeV. By selecting two fast protons at low relative energy Epp, the measured analysing powers and spin correlations are sensitive to interference terms between specific neutron–proton charge-exchange amplitudes at a neutron kinetic energy of Tn≈12Td=363 MeV. An impulse approximation calculation, which takes into account corrections due to the angular distribution in the diproton, describes reasonably the dependence of the data on both Epp and the momentum transfer. This lends broad support to the current neutron–proton partial wave solution that was used in the estimation.

  7. Polarized proton induced reactions on lithium isotopes around 14 MeV

    Differential cross sections, analyzing powers, and double differential cross sections were measured for 6Li(p,x) reactions at 14.0 MeV and for 7Li(p,x) reactions at 12.0, 14.0 and 16.0 MeV. The three-body breakup reactions of 6Li(p,d)pα, 6Li(p,α)pd and 7Li(p,t)pα were intensively studied in order to understand their reaction mechanisms, which must be similar in the neutron induced reactions. Moreover, the contribution of the four-body 6Li(p,2p)nα breakup reaction in the 6Li(p,xp) reaction has been estimated and analyzed on the basis of the sequential decay processes. The optical potential of the p-7Li system has been discussed. (author)

  8. The angular distribution of neutron-proton scattering at 27.3 MeV

    The results of experimental investigations are presented to study a forward-backward asymmetry in the n-p scattering angular distribution for angles from 34 deg to 116 deg. To improve the precision of the measurements the neutron detector efficiency factor was analyzed in the 5-25 MeV energy range. Features of the time-of-flight spectrum are discussed. The data obtained confirm the asymmetry predicted by the phase shift evaluations

  9. Predictions of 200 MeV proton scattering from polarized 3He

    Predictions of the differential cross sections and spin observables of p-3He scattering at 200 MeV have been made using a microscopic model of scattering in which a complex, nonlocal optical potential is obtained by full folding an effective two-nucleon interaction with nuclear structure found from a large basis shell model calculation. Good fits to data were obtained but there remains a need for better spectroscopy of the target. (authors)

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

    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)

  11. Comparisons of high latitude E > 20 MeV proton geomagnetic cutoff observations with predictions of the SEPTR model

    A. Ling

    Full Text Available Radiation effects from solar energetic proton (SEP events are a concern when the International Space Station reaches high latitudes accessible to SEPs. We use data from the 20–29 and 29–64 MeV proton channels of the Proton/Electron Telescope on the SAMPEX satellite during nine large SEP events to determine the experimental geographic cutoff latitudes for the two energy ranges. These are compared with calculated cutoff latitudes based on a computer model, SEPTR (solar energetic particle tracer. The observed cutoff latitudes are systematically equatorward of the latitudes calculated by the SEPTR program using a Tsyganenko field model, but that model produces mean values of ~ 2° for latitudinal differences with observations, DLat, which are ~ 3 times smaller than those using the 1995 International Geomagnetic Reference Field model alone. The number distributions of DLat are peaked near 0° and decline toward higher values. With the Tsyganenko model, we find no significant trend in either the DLat or their variances with increasing Kp .Key words. Interplanetary physics (energetic particles – Magnetospheric physics (polar cap phenomena – Space plasma physics (charged particle motion and acceleration

  12. Proton-neutron correlation in the deuteron breakup at 56 MeV and prior-form DWBA analysis

    Proton-neutron angular correlations in the 12C, 51V and 118Sn(d,pn) reactions have been measured at 56 MeV to investigate the deuteron breakup process. The elastic breakup which leaves the target nucleus in its ground state dominates the coincident spectra. The experimental data have been analyzed using the prior-form DWBA. For both nuclear and Coulomb breakup, sufficient convergence of the calculations is obtained by including the pn angular momenta up to l=2. For the nuclear breakup calculations, the l=0 and 2 contributions dominate the cross sections. For the Coulomb breakup the l=1 contribution is predominant. The DWBA calculations reproduce the experimental data in the angular region where the protons are emitted on the side of the beam opposite to the neutrons. On the other hand the calculations overestimate the breakup cross sections by a factor of 2 to 10 in the angular region where the protons are emitted on the same side of the beam as the neutrons. The disagreement may be due to the insufficient treatment of the final-state distorted wave in the prior-form DWBA. (author)

  13. Validation of nuclear models in Geant4 using the dose distribution of a 177 MeV proton pencil beam

    Hall, David C.; Makarova, Anastasia; Paganetti, Harald; Gottschalk, Bernard

    2016-01-01

    A proton pencil beam is associated with a surrounding low-dose envelope, originating from nuclear interactions. It is important for treatment planning systems to accurately model this envelope when performing dose calculations for pencil beam scanning treatments, and Monte Carlo (MC) codes are commonly used for this purpose. This work aims to validate the nuclear models employed by the Geant4 MC code, by comparing the simulated absolute dose distribution to a recent experiment of a 177 MeV proton pencil beam stopping in water. Striking agreement is observed over five orders of magnitude, with both the shape and normalisation well modelled. The normalisations of two depth dose curves are lower than experiment, though this could be explained by an experimental positioning error. The Geant4 neutron production model is also verified in the distal region. The entrance dose is poorly modelled, suggesting an unaccounted upstream source of low-energy protons. Recommendations are given for a follow-up experiment which could resolve these issues.

  14. Investigation of the Deuteron Breakup on Proton Target in the Forward Angular Region at 130 MeV

    A set of differential cross-section data of the 1H(d, pp)n breakup reaction at 130 MeV deuteron beam energy has been measured in the domain of very forward polar angles with the use of the Germanium Wall detector at the Forschungszentrum Jülich. The data obtained for over 1000 kinematical points (112 geometries) are compared with the theoretical predictions based on various models of the three-nucleon (3N) dynamics. They comprise: the realistic nucleon-nucleon potentials alone or combined with the three-nucleon force (3NF), the coupled-channel calculations with the explicit treatment of the Δ-isobar excitation and finally, the potentials derived from chiral perturbation theory. In the part of the phase space studied, the Coulomb interaction between protons has a strong impact on the differential cross section of the breakup reaction. The strongest Coulomb effects are found in regions where the relative energy of the two protons is the smallest. In these regions the data are well reproduced exclusively by calculations which include the electromagnetic repulsion between protons. In spite of the dominance of the Coulomb force in the phase space studied, the contribution of 3NF effects is also observed. (author)

  15. X-ray diffraction studies of 145MeV proton-irradiated AlBeMet 162

    Mohamed Elbakhshwan

    2016-08-01

    Full Text Available AlBeMet 162 (Materion Co., formerly Brush Wellman has been irradiated with 145MeV protons up to 1.2×1020cm−2 fluence, with irradiation temperatures in the range of 100–220°C. Macroscopic post-irradiation evaluation on the evolution of mechanical and thermal properties was integrated with a comprehensive X-ray- diffraction study using high-energy monochromatic and polychromatic X-ray beams, which offered a microscopic view of the irradiation damage effects on AlBeMet. The study confirmed the stability of the metal–matrix composite, its resistance to proton damage, and the continuing separation of the two distinct phases, fcc aluminum and hcp beryllium, following irradiation. Furthermore, based on the absence of inter-planar distance change during proton irradiation, it was confirmed that the stacking faults and clusters on the Al (111 planes are stable, and thus can migrate from the cascade region and be absorbed at various sinks. XRD analysis of the unirradiated AlBeMet 162 showed clear change in the texture of the fcc phase with orientation especially in the Al (111 reflection which exhibits a “non-perfect” six-fold symmetry, implying lack of isotropy in the composite.

  16. Neutron yield and induced radioactivity: a study of 235-MeV proton and 3-GeV electron accelerators

    This study evaluated the magnitude of potential neutron yield and induced radioactivity of two new accelerators in Taiwan: a 235-MeV proton cyclotron for radiation therapy and a 3-GeV electron synchrotron serving as the injector for the Taiwan Photon Source. From a nuclear interaction point of view, neutron production from targets bombarded with high-energy particles is intrinsically related to the resulting target activation. Two multi-particle interaction and transport codes, FLUKA and MCNPX, were used in this study. To ensure prediction quality, much effort was devoted to the associated benchmark calculations. Comparisons of the accelerators' results for three target materials (copper, stainless steel and tissue) are presented. Although the proton-induced neutron yields were higher than those induced by electrons, the maximal neutron production rates of both accelerators were comparable according to their respective beam outputs during typical operation. Activation products in the targets of the two accelerators were unexpectedly similar because the primary reaction channels for proton- and electron-induced activation are (p,pn) and (γ,n), respectively. The resulting residual activities and remnant dose rates as a function of time were examined and discussed. (authors)

  17. Production of krypton and xenon isotopes in thick stony and iron targets isotropically irradiated with 1600 MeV protons

    Gilabert, E; Lavielle, B; Leya, I; Michel, R; Neumann, S

    2002-01-01

    Two spherical targets made of gabbro with a radius of 25 cm and of steel with a radius of 10 cm were irradiated isotropically with 1600 MeV protons at the SATURNE synchrotron at Laboratoire National Saturne (LNS)/CEN Saclay, in order to simulate the production of nuclides in meteorites induced by galactic cosmic-ray protons in space. These experiments supply depth-dependent production rate data for a wide range of radioactive and stable isotopes in up to 28 target elements. In this paper, we report results for /sup 78/Kr, /sup 80-86/Kr isotopes in Rb, Sr, Y and Zr and for /sup 124/Xe, /sup 126/Xe, /sup 128-132/Xe, /sup 134/Xe, /sup 136/Xe isotopes in Ba and La. Krypton and xenon concentrations have been measured at different depths in the spheres by using conventional mass spectrometry. Based on Monte-Carlo techniques, theoretical production rates are calculated by folding depth-dependent spectra of primary and secondary protons and secondary neutrons with the excitation functions of the relevant nuclear reac...

  18. Experimental microdosimetric distributions of protons, from 19 to 65 MeV, using an A150-walled low pressure proportional counter

    Microdosimetric distributions of protons, from 19 to 65 MeV, were measured using an A150-walled Low Pressure Proportional Counter at the cyclotron facility in the National Inst. of Radiological Sciences. The measured distributions were found to be very different from the spectra assumed by the Continuous Slowing Down Approximation. The measurements consisted of determining the energy deposition by direct incident protons, by secondary electrons produced in the wall of the detector and by scattered protons at the wall. The secondary electron and the scattered proton distributions were studied using analytical functions and the MCNPX Monte Carlo code, respectively. (authors)

  19. 15-MeV proton emission from ICRF-heated plasmas

    Jarvis, O.N.; Conroy, S.W.; Hone, M.; Sadler, G.J.; Van Belle, P. [Commission of the European Communities, Luxembourg (Luxembourg)

    1994-07-01

    {sup 3} He-d fusion reaction protons emitted from ICRF-heated discharges were recorded with a silicon diode detector installed in the JET tokamak. The detection rates demonstrated that sawtooth crashes eject fast particles from the inner region of the plasma. The energy spectra of the fusion product protons using H minority provided evidence for the second harmonic acceleration of deuterons at sub-MW levels of RF power and those with {sup 3} He minority did not possess the expected twin-lobed shape predicted by kinematics calculations. (authors). 5 refs., 6 figs.

  20. Design and rf tuning of the KEK 40 MeV proton linear accelerator

    An Alvarez linac was designed and constructed on the basis of a model linac study to increase the output energy from 20 to 40 MeV. The linac was tuned by frequency tuners and post couplers. Stabilization of the field was achieved and a variation within ± 0.7 % of the accelerating field was obtained. An equivalent circuit analysis which can numerically solve loop equations, including stem and post currents in addition to tank current, can explain the rf characteristics of a postcoupled structure. (author)

  1. Measurement of eta photoproduction on the proton from threshold to 1500 MeV

    Bartalini, O.; Bellini, V.; Bocquet, J.P.; Calvat, P.; Capogni, M.; Casano, L.; Castoldi, M; D'Angelo, A.(Università di Roma Tor Vergata and INFN, Sezione di Roma Tor Vergata, Rome, Italy); Didelez, J. P.; Di Salvo, R.; Fantini, A.; Franco, D.(APC, Université Paris Diderot, Sorbonne Paris Cité, 75205 Paris, France); Gaulard, C.; Gervino, G.; Ghio, F.

    2007-01-01

    Beam asymmetry and differential cross section for the reaction gamma+p->eta+p were measured from production threshold to 1500 MeV photon laboratory energy. The two dominant neutral decay modes of the eta meson, eta->2g and eta->3pi0, were analyzed. The full set of measurements is in good agreement with previously published results. Our data were compared with three models. They all fit satisfactorily the results but their respective resonance contributions are quite different. The possible ph...

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

    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.

  3. Gas accumulation at grain boundaries during 800 MeV proton irradiation of aluminium and aluminium-alloys

    Samples of pure aluminium (99.9999%) and commercial Al-2.7%Mg (AlMg3) and Al-1.1%Mg-0.5%Si (Al6061) alloys were irradiated with 800 MeV protons at the Los Alamos Meson Physics Facility (LAMPF) at a temperature between 40-1000C to a maximum dose of 0.2 dpa. Transmission electron microscopy (TEM) showed a complete absence of voids or bubbles in the grain interiors of the aluminium and the aluminium-alloys. Bubbles were clearly visible by TEM at grain boundaries in pure Al and the AlMg3 alloy; but bubbles were not visible in the Al6061 alloy. The bubble density in the AlMg3 alloy was considerably higher than in pure Al. The amount of gas accumulation at grain boundaries was found to depend on gas generation rate, alloying and cold-work microstructure. (orig.)

  4. Microstructure and mechanical properties of medium energy (600-800 MeV) proton irradiated commercial aluminium alloys

    Commercial AlMg- and AlMgSi-alloys were irradiated with medium energy (600-800 MeV) protons to a nominal fluence of 3.2 x 1024 p/m2 which yields by calculation a displacement damage of 0.2 dpa and helium and hydrogen generation of 67 and 275 appm, respectively. Post-irradiation tensile testing revealed a very marked degree of irradiation-induced softening in the cold-worked AlMg-alloy as well as in the precipitation-hardened AlMgSi-alloy. The TEM examination of the irradiated specimens showed that neither the cold-work microstructure in the AlMg-alloy nor the G.P. zone type precipitates in the AlMgSi-alloy survive under the irradiation conditions used in the present experiment. Results of complimentary investigations (i.e., hardness measurements, optical microscopy and SEM-fractography) are also presented. (author)

  5. Experimental cross-sections for proton induced nuclear reactions on mercury up to 65 MeV

    Hermanne, A.; Tárkányi, F.; Takács, S.; Ditrói, F.; Szücs, Z.; Brezovcsik, K.

    2016-07-01

    Cross-sections for formation of activation products induced by protons on natural mercury targets were measured. Results for 196m,196g,197g(cum), 198m,198g,199g(cum), 200g(cum), 201,202Tl, 194g(cum), 195g(cum), 196g(cum), 198m,199g(cum) Au and 195m,197m,203Hg are presented up to 65 MeV incident particle energy, many of these for the first time. The experimental data are compared with literature values and with the predictions of the TALYS 1.6 code (results taken from TENDL-2015 on-line library), thick target yields were derived and possible applications in biomedical sciences are discussed.

  6. 9Be(p,pα) 5He cluster knockout reaction with 150 MeV polarized protons

    The (p,pα) cluster knockout reaction on 9Be was investigated using polarized incident protons. Coincident data for eight quasifree angle pairs were obtained at a bombarding energy of 150 MeV. Both differential cross sections and analyzing powers were measured for the energy-sharing distribution. Distorted wave impulse approximation calculations indicate that the reaction is dominated by a quasifree knockout process, and that a D-state component of the cluster-core wave function is important for larger momentum transfer. Extracted absolute spectroscopic factors for both S- and D-state knockout are in good agreement with theoretical predictions. The analyzing power follows the trend of free p-4He scattering and agrees with the distorted wave impulse approximation calculation reasonably well. Near zero recoil momentum, the spin-orbit interaction in the distorted waves plays little role

  7. Investigation of activation cross sections of proton induced reactions on indium up to 70 MeV for practical applications

    Tárkányi, F; Hermanne, A; Takács, S; Baba, M

    2016-01-01

    Excitation functions were measured for production of the $^{113,111,110}$Sn, $^{115m,114m,113m,112m,111g,110g}$In and $^{111m,109}$Cd radioisotopes by bombardment of In targets with proton beams up to 70 MeV, some of them for the first time. The new results are compared with the earlier experimental data and with the theoretical data in the TENDL-2014 (Talys1.6 based) library. Thick target yields were deduced and application of the new data for production of medically relevant $^{110m}$In, $^{111g}$In, $^{113m}$In and $^{114m}$In, as well as applicability for thin layer activation (TLA) are discussed.

  8. Measurement of neutron dose equivalent and penetration in concrete for 230 MeV proton bombardment of Al, Fe, and Pb targets

    Secondary neutron production from protons striking accelerator beam delivery components and the patient constitute the principal radiation hazard for 70-300 MeV accelerators used in proton radiation therapy. Because of the large mean free path of these high energy neutrons, neutron attenuation requires massive shields. To this end, we measured neutron dose as a function of emission angle and depth in concrete for the radiation environment produced by 230 MeV protons striking stopping targets of aluminium, iron, and lead. By using microdosimetric instrumentation, dose equivalent values were deduced. From these data, dose equivalent penetration as a function of depth in concrete and neutron emission angle were determined. Neutron production was found to vary rapidly with emission angle, while differences in dose equivalent values per incident proton as a function of depth and angle depended only slightly on target material. (author)

  9. Neutron-proton elastic diffusion study at low transfer between 400-1000 MeV

    This thesis presents the first complete results of forward differential cross-section, over the entire range of the intermediate energies, in the neutron-proton system. The neutron beam is produced with the synchrotron Saturne II, using the reaction of deuteron break-up, which gives it a relatively high intensity and a small energy dispersion. The experimental apparatus is a drift ionization chamber, IKAR, filled with high pressure gas which plays the double role of target and detector of the recoil proton. The use of a neutral beam requires new procedures in the analysis, more elaborate than in the case of charged projectiles, where scattered particles were detected in coincidence in wire chambers. The results are then normalized and discussed, using a phenomenological parametrization, and integrated in a continuously energy-dependent phase-shifts analysis. An entirely analytic Glauber calculation allows us to estimate the validity of the normalization method

  10. Nanodosimetric cluster size distributions of a 250 MeV therapeutic proton beam

    Full text: Nanodosimetry enables the energy deposition of ionizing radiation on a DNA scale to be determined. The purpose of this research is to conduct nanodosimetric measurements of proton radiation fields at the proton accelerator of Loma Linda University Medical Center (LLUMC) in an attempt to verify a Monte Carlo simulation system. To achieve this, these measurements will be compared to the output from a Monte Carlo simulation system that is being developed to simulate the nanodosimetric spectra of the LLUMC beamline. Once verified, this Monte Carlo system will provide a very powerful tool with which to measure the effect of radiation fields on a nanoscopic level without submitting humans or expensive electronics to such a potentially damaging environment. Copyright (2005) Australian Institute of Physics

  11. An 800-MeV superconducting LINAC to support megawatt proton operations at Fermilab

    Derwent, Paul; Lebedev, Valeri

    2015-01-01

    Active discussion on the high energy physics priorities in the US carried out since summer of 2013 resulted in changes in Fermilab plans for future development of the existing accelerator complex. In particular, the scope of Project X was reduced to the support of the Long Base Neutrino Facility (LBNF) at the project first stage. The name of the facility was changed to the PIP-II (Proton Improvement Plan). This new facility is a logical extension of the existing Proton Improvement Plan aimed at doubling average power of the Fermilab's Booster and Main Injector (MI). Its design and required R&D are closely related to the Project X. The paper discusses the goals of this new facility and changes to the Project X linac introduced to support the goals.

  12. Elastic scattering of polarized protons on helium three at 800 MeV

    A set of spin dependent parameters and cross sections has been measured for polarized p-3He elastic scattering over the range of q .7 to 4.2 fm-1. The experiment was done at the Los Alamos Meson Physics Facility (LAMPF) using the High Resolution Spectrometer (HRS) with a polarized proton beam at .8 GeV. The focal plane polarimeter of the HRS was used to determine the spin direction of the scattered proton. Since 3He is one of the simplest nuclei, polarized p-3He scattering provides a very sensitive test of multiple scattering theories. The theoretical analysis was done by using two different wave functions for 3He as input to the multiple scattering theory. The theoretical calculations and experimental data together will give us useful information about nucleon-nucleon amplitudes and also help us to obtain a better understanding of the scattering process. 68 refs., 55 figs., 9 tabs

  13. A radioisotope production facility using 70-120 MeV protons

    A facility with five target stations for the production of radioisotopes is now available for use by research groups. Four production systems can accept beam intensities from 10 to 100 microamps, with the fifth being under development for proton therapy. The first target is molten LiBr, the second is molten NaI, the third system is for irradiating solid target materials, and the fourth target is molten cesium

  14. Calculating Variations in Biological Effectiveness for a 62 MeV Proton Beam.

    Carante, Mario Pietro; Ballarini, Francesca

    2016-01-01

    A biophysical model of radiation-induced cell death and chromosome aberrations [called BIophysical ANalysis of Cell death and chromosome Aberrations (BIANCA)] was further developed and applied to therapeutic protons. The model assumes a pivotal role of DNA cluster damage, which can lead to clonogenic cell death following three main steps: (i) a DNA "cluster lesion" (CL) produces two independent chromosome fragments; (ii) fragment mis-rejoining within a threshold distance d gives rise to chromosome aberrations; (iii) certain aberration types (dicentrics, rings, and large deletions) lead to clonogenic inactivation. The yield of CLs and the probability, f, that a chromosome fragment remains un-rejoined even if other fragment(s) are present within d, were adjustable parameters. The model, implemented as a MC code providing simulated dose-responses directly comparable with experimental data, was applied to pristine and modulated Bragg peaks of the proton beam used to treat eye melanoma at INFN-LNS in Catania, Italy. Experimental survival curves for AG01522 cells exposed to the Catania beam were reproduced, supporting the model assumptions. Furthermore, cell death and chromosome aberrations at different depths along a spread-out Bragg peak (SOBP) dose profile were predicted. Both endpoints showed an increase along the plateau, and high levels of damage were found also beyond the distal dose fall-off, due to low-energy protons. Cell death and chromosome aberrations were also predicted for V79 cells, in the same irradiation scenario as that used for AG01522 cells. In line with other studies, this work indicated that assuming a constant relative biological effectiveness (RBE) along a proton SOBP may be sub-optimal. Furthermore, it provided qualitative and quantitative evaluations of the dependence of the beam effectiveness on the considered endpoint and dose. More generally, this work represents an example of therapeutic beam characterization avoiding the use of

  15. Calculating variations in biological effectiveness for a 62 MeV proton beam

    Mario Pietro Carante

    2016-04-01

    Full Text Available A biophysical model of radiation-induced cell death and chromosome aberrations (called BIANCA, BIophysical ANalysis of Cell death and chromosome Aberrations was further developed and applied to therapeutic protons. The model assumes a pivotal role of DNA cluster damage, which can lead to clonogenic cell death following three main steps: i a DNA Cluster Lesion (CL produces two independent chromosome fragments; ii fragment mis-rejoining within a threshold distance d gives rise to chromosome aberrations; iii certain aberration types (dicentrics, rings and large deletions lead to clonogenic inactivation. The yield of CLs and the probability, f, that a chromosome fragment remains un-rejoined even if other fragment(s are present within d, were adjustable parameters. The model, implemented as a MC code providing simulated dose-responses directly comparable with experimental data, was applied to pristine and modulated Bragg peaks of the proton beam used to treat eye melanoma at INFN-LNS in Catania, Italy. Experimental survival curves for AG01522 cells exposed to the Catania beam were reproduced, supporting the model assumptions. Furthermore, cell death and chromosome aberrations at different depths along a SOBP (Spread-Out Bragg Peak dose profile were predicted. Both endpoints showed an increase along the plateau, and high levels of damage were found also beyond the distal dose fall-off, due to low-energy protons. Cell death and chromosome aberrations were also predicted for V79 cells, in the same irradiation scenario as that used for AG01522 cells. In line with other studies, this work indicated that assuming a constant RBE along a proton SOBP may be sub-optimal. Furthermore, it provided qualitative and quantitative evaluations of the dependence of the beam effectiveness on the considered endpoint and dose. More generally, this work represents an example of therapeutic beam characterization avoiding the use of experimental RBE values, which can be

  16. Dose distribution outside the target volume for 170-MeV proton beam

    Pachnerová Brabcová, Kateřina; Ambrožová, Iva; Kubančák, Ján; Puchalska, M.; Vondráček, V.; Molokanov, A. G.; Sihver, L.; Davídková, Marie

    2014-01-01

    Roč. 161, 1-4 (2014), s. 410-416. ISSN 0144-8420 R&D Projects: GA MŠk(CZ) LG13031; GA MŠk LA08015; GA MŠk LG14004 Institutional support: RVO:61389005 Keywords : linear energy transfer * proton beams * particles Subject RIV: BG - Nuclear, Atomic and Molecular Physics, Colliders Impact factor: 0.913, year: 2014

  17. Proton induced nuclear reactions on natural antimony up to 17 MeV

    Elbinawi, Alaa; Al-abyad, Mogahed; Hassan, Khaled F. [Atomic Energy Authority, Cairo (Egypt). Cyclotron Facility; Abd-Elmageed, Karima E. [Benha Univ. (Egypt). Dept. of Physics; Ditroi, Ferenc [Hungarian Academy of Sciences, Debrecen (Hungary). Inst. for Nuclear Research (ATOMKI)

    2016-08-01

    The activation cross sections of proton induced reactions on {sup nat}Sb target leading to the formation of the radioisotopes {sup 121m,g,123m}Te were measured. The experimental excitation functions were compared with the theoretical model calculations using the codes EMPIRE-3.1 and TALYS-1.4. The integral yields of the three radionuclides were calculated and the possibility of their production is discussed.

  18. Proton induced nuclear reactions on natural antimony up to 17 MeV

    The activation cross sections of proton induced reactions on natSb target leading to the formation of the radioisotopes 121m,g,123mTe were measured. The experimental excitation functions were compared with the theoretical model calculations using the codes EMPIRE-3.1 and TALYS-1.4. The integral yields of the three radionuclides were calculated and the possibility of their production is discussed.

  19. Calculating Variations in Biological Effectiveness for a 62 MeV Proton Beam

    Carante, Mario Pietro; Ballarini, Francesca

    2016-01-01

    A biophysical model of radiation-induced cell death and chromosome aberrations [called BIophysical ANalysis of Cell death and chromosome Aberrations (BIANCA)] was further developed and applied to therapeutic protons. The model assumes a pivotal role of DNA cluster damage, which can lead to clonogenic cell death following three main steps: (i) a DNA “cluster lesion” (CL) produces two independent chromosome fragments; (ii) fragment mis-rejoining within a threshold distance d gives rise to chromosome aberrations; (iii) certain aberration types (dicentrics, rings, and large deletions) lead to clonogenic inactivation. The yield of CLs and the probability, f, that a chromosome fragment remains un-rejoined even if other fragment(s) are present within d, were adjustable parameters. The model, implemented as a MC code providing simulated dose–responses directly comparable with experimental data, was applied to pristine and modulated Bragg peaks of the proton beam used to treat eye melanoma at INFN-LNS in Catania, Italy. Experimental survival curves for AG01522 cells exposed to the Catania beam were reproduced, supporting the model assumptions. Furthermore, cell death and chromosome aberrations at different depths along a spread-out Bragg peak (SOBP) dose profile were predicted. Both endpoints showed an increase along the plateau, and high levels of damage were found also beyond the distal dose fall-off, due to low-energy protons. Cell death and chromosome aberrations were also predicted for V79 cells, in the same irradiation scenario as that used for AG01522 cells. In line with other studies, this work indicated that assuming a constant relative biological effectiveness (RBE) along a proton SOBP may be sub-optimal. Furthermore, it provided qualitative and quantitative evaluations of the dependence of the beam effectiveness on the considered endpoint and dose. More generally, this work represents an example of therapeutic beam characterization avoiding the use of

  20. A fully microscopic model of 200 MeV proton-{sup 12}C elastic and inelastic scattering

    Karataglidis, S.; Dortmans, P.J.; Amos, K.; de Swiniarski, R.

    1996-03-01

    An effective two nucleon (NN) interaction in the nuclear medium is defined from an accurate mapping of the NN g matrices obtained by solving the Brueckner-Bethe-Goldstone equations for infinite nuclear matter. That effective interaction is used in a fully microscopic calculation of the nonlocal effective proton-{sup 12}C interaction from which are obtained predictions of the differential cross section and analysing power for 200 MeV elastic scattering. The relative motion wave functions so found are used as the distorted waves in a distorted wave approximation (DWA) study of select inelastic scattering events. The effective NN interaction is used as the transition operator in those calculations. The relevant nuclear spectroscopy for the elastic and DWA (p, p`) calculations is found from a full (0 + 2) {Dirac_h}{omega} shell model evaluation of the positive parity states while a restricted (1 + 3){Dirac_h}{omega} has been used to give the negative parity states. Results are compared with those of the 0p-shell model of Cohen and Kurath or with those based upon axially symmetric, projected Hartree-Fock calculations. The diverse structure model wave functions are assessed by using them in calculations to compare with measured longitudinal, transverse electric and transverse magnetic form factors from electron scattering to many of the excited states of {sup 12}C. Using those models of the structure of {sup 12}C in the completely microscopic model of the elastic and inelastic scattering of 200 MeV protons, good fits have been found to the cross section and analysing power data. 50 refs., 3 tabs., 20 figs.

  1. Combined proton-recoil and neutron time-of-flight spectrometer for 14 MeV neutrons

    The main effort put into this work is the foundation of a reliable physical basis for a 12-16 MeV neutron-spectrometer at JET. The essential problem is the amount of scatterer that can be incorporated without losing resolution. We have found two possible methods, the use of a pure hydrogen scatterer and the use of a polyethylene foil scatterer. The pure hydrogen solution gives a very complicated spectrometer with large detectors. The polyethylene solution is limited by the thickness and the width of the foil. We judge the solution with the polyethylene foil to be the most promising one for a reliable spectrometer. However, a large foil area is needed. This gives a spectrometer design with an annular foil, an annular neutron detection system, and a central proton-detector. An efficiency of 10-6 counts/s per n/cm2,s at the foil can be obtained with a resolution in the order of 100 keV for 14 MeV neutrons. Following the General Requirements given in the contract of this work, we concluded that an instrument with the desired properties can be made. The instruments is able to give useful information about the plasma from plasma temperatures of about 5 keV. (Authors)

  2. Direct measurement of prompt neutrons emitted in fission of 226Ra by 12 MeV protons

    Prompt neutron energy distributions were measured at 0 deg and 90 deg with respect to the fission axis, in correlation with the mass-energy distribution of the fragments, for the fission of 226Ra induced by 12 MeV protons. The average number and average kinetic energy of prefission and postfission neutrons were obtained as a function of fragment mass and total kinetic energy. The average number of prefission neutrons emitted is 0.33+-0.15 n/fission (this includes also contributions from scission neutrons). By comparing this result with calculations of the average number of 'true' prefission neutrons, it was found that the number of 'true' prefission neutrons is zero. The average number of postfission neutrons emitted from both fragments is 3,20+-0.20 with an average kinetic energy of 1.33+-0.07 MeV. The dependence of the number of postfission neutrons on the fragment mass can be interpreted as a combination of a saw-tooth structure for the asymmetric mass division and a linearly increasing function for the symmetric mass division. (author)

  3. Changes of structure and electrical conductivity of multi-walled carbon nanotubes film caused by 3 MeV proton irradiation

    Yang, Jianqun; Li, Xingji, E-mail: lxj0218@hit.edu.cn; Liu, Chaoming; Ma, Guoliang

    2015-01-15

    Highlights: • 3 MeV protons could lead to evident changes in morphology of the MWCNTs film. • 3 MeV protons damage the structure of the MWCNTs, including increasing the disorder and the formation of functional groups. • With increasing the irradiation fluence, the electrical conductivity of the irradiated MWCNTs film by 3 MeV protons decreases. - Abstract: The effects of 3 MeV proton irradiation for fluences of 3.5 × 10{sup 10} cm{sup −2} to 3.1 × 10{sup 12} cm{sup −2} on structure and electrical conductivity of multi-walled carbon nanotubes (MWCNTs) film were investigated. The pristine and the irradiated MWCNTs films were characterized using scanning electron microscopy (SEM), Raman spectroscopy, X-ray photoelectron spectroscopy (XPS), Fourier transform infrared spectroscopy (FTIR), elemental analysis (EA) and electron paramagnetic resonance (EPR) spectroscopy in order to investigate the effects of irradiation on their structure. Electrical conductivity of the MWCNTs films was characterized before and after irradiation. SEM analysis reveals that the proton irradiation for the high fluence (more than 3.6 × 10{sup 11} cm{sup −2}) leads to evident changes in morphology of the MWCNTs film, such as forming uneven film surface, curve, shrinkage and fragmentation of nanotubes. Based on Raman, XPS, FTIR and EA analyses, it is confirmed that the 3 MeV protons with high fluence (more than 3.6 × 10{sup 11} cm{sup −2}) can damage the structure of the MWCNTs, including increase of the disorder and the formation of functional groups. EPR spectroscopy shows that the electrons delocalized over carbon nanotubes increase with increasing irradiation fluence, implying that the MWCNTs film might be sensitive to ionizing radiation to some extent. With increasing the irradiation fluence, the electrical conductivity of the MWCNTs film decreases due to the structural and morphological damage.

  4. Relative biological efficiency of 592 MeV protons. Analysis of the biological effect of secondary radiation

    The relative biological efficiency (RBE) of high energy protons is of importance because of their effects in the field of radioprotection around large accelerators and during space-flights. The nature of the interactions between 592 MeV protons and biological tissues makes it necessary to take into consideration the contribution of secondary radiation to the biological effect. Since it is not possible to obtain from a synchrotron a beam having a sufficiently large cross-section to irradiate large animals, one has to resort to certain devices concerning the mode of exposure when small laboratory animals are used. By irradiating rats individually and in groups, and by using the lethal test as a function of time, the authors show that the value of the RBE is different for animals of the same species having the same biological parameters. Thus there appears an increase in the biological effect due to secondary radiation produced in nuclear cascades which develop in a large volume, for example that of a human being. (author)

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

    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.

  6. –, – and deep level transient spectroscopy study of 24 MeV proton-irradiated bipolar junction transistor

    K V Madhu; S R Kulkarni; R Damle

    2010-01-01

    This paper describes the effect of 24 MeV proton irradiation on the electrical characteristics of a pnp bipolar junction transistor 2N 2905A. –, – and DLTS measurements are carried out to characterize the transistor before and after irradiation. The properties of deep level defects observed in the bulk of the transistor are investigated by analysing the DLTS data. Two minority carrier levels, C – 0.27 eV and C – 0.58 eV and one majority carrier level, V + 0.18 eV are observed in the base collector junction of the transistor. The irradiated transistor is subjected to isochronal annealing. The influence of isochronal annealing on –, – and DLTS characteristics are monitored. Most of the deep level defects seem to anneal out above 400° C. It appears that the deep level defects generated in the bulk of the transistor lead to transistor gain degradation. A comparison of proton- and electron-induced gain degradation is made to assess the vulnerability of pnp transistor as against npn transistors.

  7. Cross-field diffusion of energetic (100 keV to 2 MeV) protons in interplanetary space

    Costa Jr, Edio da [Instituto Federal de Minas Gerais-IFMG, Ouro Preto, MG, 35400-000 (Brazil); Tsurutani, Bruce T. [Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109 (United States); Alves, Maria Virgínia; Echer, Ezequiel [Instituto Nacional de Pesquisas Espaciais-INPE, São José dos Campos, SP, 12227-010 (Brazil); Lakhina, Gurbax S., E-mail: edio.junior@ifmg.edu.br, E-mail: costajr.e@gmail.com [Indian Institute for Geomagnetism, Navi Mumbai 410 218 (India)

    2013-12-01

    Magnetic field magnitude decreases (MDs) are observed in several regions of the interplanetary medium. In this paper, we characterize MDs observed by the Ulysses spacecraft instrumentation over the solar south pole by using magnetic field data to obtain the empirical size, magnetic field MD, and frequency of occurrence distribution functions. The interaction of energetic (100 keV to 2 MeV) protons with these MDs is investigated. Charged particle and MD interactions can be described by a geometrical model allowing the calculation of the guiding center shift after each interaction. Using the distribution functions for the MD characteristics, Monte Carlo simulations are used to obtain the cross-field diffusion coefficients as a function of particle kinetic energy. It is found that the protons under consideration cross-field diffuse at a rate of up to ≈11% of the Bohm rate. The same method used in this paper can be applied to other space regions where MDs are observed, once their local features are well known.

  8. Tensile properties in zircaloy-II after 590 MeV proton irradiation

    Dai, Y. [Paul Scherrer Inst. (PSI), Villigen (Switzerland); Victoria, M. [Ecole Polytechnique Federale, Lausanne (Switzerland)

    1997-09-01

    In order to investigate radiation potential damage effects on the SINQ Zircaloy-rod target, four Zircaloy-II tensile specimens were irradiated at the PIREX facility in 1995 to a proton fluence about 3x10{sup 20} p/cm{sup 2}, which produced a radiation damage of about 1.35 displacements per atom (dpa). Tensile test results show that, although there is some reduction in tensile elongation, substantial ductility still exists after such irradiation dose which corresponds to the peak value obtained in the SINQ target for 23 days operation at 1 mA. (author) 1 fig., 2 refs.

  9. ''Wine-bottle'' optical potentials and the inelastic scattering of protons near 200 MeV

    The effects on inelastic proton scattering of using potentials with non-standard 'wine-bottle' shapes are studied. Several wine-bottle potentials are found which give elastic scattering equivalent to that obtained from a conventional Woods-Saxon potential, and the inelastic scattering is calculated. There are large reductions (as much as a factor of two) in the predicted cross sections for exciting 40Ca, smaller reductions for 208Pb. When the deformed optical potential model is used, roughly one-half of the effect is due to the changes in the transition potential and one-half to the use of different distorted waves. (orig.)

  10. Performance of timing Resistive Plate Chambers with protons from 200 to 800 MeV

    A prototype composed of four resistive plate chamber layers has been exposed to quasi-monoenergetic protons produced from a deuteron beam of varying energy (200 to 800 AMeV) in experiment S406 at GSI, Darmstadt, Germany. The aim of the experiment is to characterize the response of the prototype to protons in this energy range, which deposit from 1.75 to 6 times more energy than minimum ionizing particles. Each layer, with an active area of about 2000 × 500 mm2, is made of modules containing the active gaps, all in multigap construction. Each gap is defined by 0.3 mm nylon mono-filaments positioned between 2.85 mm thick float glass electrodes. The modules are operated in avalanche mode with a non-flammable gas mixture composed of 90% C2H2F4 and 10% SF6. The signals are readout by a pick-up electrode formed by 15 copper strips (per layer), spaced at a pitch of 30 mm, connected at both sides to timing front end electronics. Results show an uniform efficiency close to 100% along with a timing resolution of around 60 ps on the entire 2000 × 500 mm2 area