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. 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...

  1. 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

  2. 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

  3. 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).

  4. 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.

  5. 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.

  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

    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

    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

  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. 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

  20. 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.

  1. 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.

  2. 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.

  3. 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

  4. 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)

  5. 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

  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. 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.

  8. 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).

  9. 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...

  10. 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.

  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; 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.

  13. 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.

  14. 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

  15. 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

  16. 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...

  17. 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)

  18. 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

  19. 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

  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. 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

  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. 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.

  19. 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)

  20. 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

  1. 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.

  2. 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.

  3. 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.)

  4. 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

  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. 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

  7. 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.

  8. 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.

  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. 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...

  13. 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

  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. 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

  18. 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

  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. 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)

  7. 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.

  8. 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.

  9. 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.)

  10. 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.

  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.; 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.

  14. 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 ...

  15. 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)

  16. 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.

  17. 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.

  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. 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

  20. 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)

  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

    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)

  7. 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.

  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. 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

  10. 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...

  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

    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

  15. 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.

  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. 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...

  20. 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

  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. 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...

  8. 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.

  9. 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.

  10. 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

  11. 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.

  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. 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)

  9. 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

  10. 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.

  11. 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)

  12. 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

  13. 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)

  14. 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.

  15. 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...

  16. 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)

  17. 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)

  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. 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.

  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. 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.

  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. 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.

  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. 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.

  10. 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

  11. 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

  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. 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

  19. 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.

  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. 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.

  5. 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)

  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. ''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.)

  9. 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.

  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

  11. Neutron- and proton-induced nuclear data evaluation of thorium, uranium and curium isotopes for energies up to 250 MeV

    The evaluation of neutron and proton nuclear data for thorium-232, U-233,234,236, and Cm-243,244,245,246 isotopes have been performed at energies up to 250 MeV. Neutron data was evaluated at energies from 20 MeV to 250 MeV, and combined with the JENDL-3.3 data at 20 MeV, while proton data was obtained for energies from 1 to 250 MeV. Nuclear model parameters are largely based on the IAEA-RIPL recommendation, and adjusted to better reproduce the available measurements. The coupled channel optical model was applied to calculate the total, reaction, elastic, and direct inelastic cross sections, and to obtain the transmission coefficients. Decay of excited nuclei was described with the Hauser-Feshbach and exciton models using the GNASH code to simultaneously handle neutron, proton, deuteron, triton, helium-3, α, γ emission and fissions. Special attention was paid to the fission cross sections for energies where experimental data are scant, using appropriate systematics and fittings. Particles and γ emission spectra after fission were calculated based on the statistical approach of Fong, and adjusted to the experimental data using the ALICE-ASH code. (author)

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

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

    1979-01-01

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

  13. Neutron- and proton-induced nuclear data evaluation of thorium, uranium and curium isotopes for energies up to 250 MeV

    Young, Ouk Lee; Jonghwa, Chang; Konobeyev, A Yu

    2004-01-01

    The evaluation of neutron- and proton nuclear data for thorium-232, U-233,234,236, and Cm-243,244,245,246 isotopes have been performed at energies up to 250 MeV. Neutron data was evaluated at energies from 20 MeV to 250 MeV, and combined with the JENDL-3.3 data at 20 MeV while proton data was obtained for energies from 1 to 250 MeV. Nuclear model parameters are largely based on the IAEA-RIPL recommendation, and adjusted to better reproduce the available measurements. The coupled channel optical model was applied to calculate the total, reaction, elastic, and direct inelastic cross sections, and to obtain the transmission coefficients. Decay of excited nuclei was described with the Hauser-Feshbach and exciton models using the GNASH code to simultaneously handle neutron, proton, deuteron, triton, helium-3, alpha , gamma emissions and fissions. Special attention was paid on the fission cross sections for energies where experimental data are scant, using appropriate systematics and fittings. Particles and gamma e...

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

    Highlights: •Study of charge collection efficiency degradation (CCE) in Si diode due to MeV H irradiation. •CCE evaluated by micro-IBIC using 4.5 MeV Li ions to probe the damaged region. •Generation of H-donors, which perturb the electrostatic properties of the diode. -- Abstract: We present the analysis of the charge collection efficiency (CCE) degradation of float zone grown n-type silicon detectors irradiated with 1.3, 2.0 and 3.0 MeV protons. The analysis was carried out by irradiating small regions (50 × 50 μm2) with a proton microbeam at fluences ranging from 1011 to 4·1012 ions/cm2 and probing the effect of irradiation by measuring the 4.5 MeV Li ion induced charge in full depletion conditions. The CCE degradation as function of the proton fluence shows an unexpected deviation from the linear behavior predicted by the Shockley–Read–Hall model of carrier recombination. The build-up of excess hydrogen related donors due to proton irradiations is suggested to be the cause of a significant perturbation of the electrostatic properties of the diode, which drastically change the electron trajectories and hence the induced charge mechanism

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

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

    2015-04-01

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

  16. Proton-induced fission at 190 MeV of W-nat, Au-197, Pb-nat, Pb-208, and Th-232

    Duijvestijn, MC; Koning, AJ; Beijers, JPM; Gastal, M; van Klinken, J; Ostendorf, RW

    1999-01-01

    Proton-induced fission at 190 MeV of W-nat, Au-197, Pb-nat, Pb-208, and Th-232 is studied by means of an innovative method based on activation analysis. The fission-product mass distribution is reconstructed from the fission-product yields, which are obtained from off-line observed gamma-ray spectra

  17. Dynamics of equatorial and polar boundaries of penetration of ∼ 1 MeV solar protons into the magnetosphere during large magnetic storm

    Dynamics of equatorial and polar boundaries of E∼ 1 MeV solar proton penetration in magnetosphere during strong magnetic storm on 03-04.04.79 is investigated using data of simultaneous measurement conducted by means of three polar satellites. Data are compared with detail latitudinal pattern of magnetospheric storm growth according to data from geomagnetic observatory world network. It is shown that extermal Earth approximation of boundary of solar proton penetration into magnetosphere during strong magnetic storm is observed a few hours before latitudinal decrease. Quasi-periodical transpositions of polar boundary of solar protons in the magnetosphere dusing substorms are detected

  18. Energy loss of MeV protons specularly reflected from metal surfaces

    A parameter-free model is presented to study the energy loss of fast protons specularly reflected from metal surfaces. The contributions to the energy loss from excitation of valence-band electrons and ionization of localized target-atom electronic states are calculated separately. The former is calculated from the induced surface wake potential using linear response theory and the specular-reflection model, while the latter is calculated in the first Born approximation. The results obtained are in good agreement with available experimental data. However, the experimental qualitative trend of the energy loss as a function of the angle of incidence is obtained when the valence-band electron model is replaced by localized target atom electron states, though with a worse quantitative agreement. copyright 1996 The American Physical Society

  19. Non-Linear Beam Transport System for the LENS 7 MeV Proton Beam

    Jones, William P; Derenchuk, Vladimir Peter; Rinckel, Thomas; Solberg, Keith

    2005-01-01

    A beam transport system has been designed to carry a high-intensity low-emittance proton beam from the exit of the RFQ-DTL acceleration system of the Indiana University Low Energy Neutron System (LENS)* to the neutron production target. The goal of the design was to provide a beam of uniform density over a 3cm by 3cm area at the target. Two octupole magnets** are employed in the beam line to provide the necessary beam phase space manipulations to achieve this goal. First order calculations were done using TRANSPORT and second order calculations have been performed using TURTLE. Second order simulations have been done using both a Gaussian beam distribution and a particle set generated by calculations of beam transport through the RFQ-DTL using PARMILA. Comparison of the design characteristics with initial measurements from the LENS commissioning process will be made.

  20. Energy loss of MeV protons specularly reflected from metal surfaces

    Juaristi, J.I. [Departamento Fisica de Materiales, Facultad de Quimicas, Universidad del Pais Vasco/Euskal Herriko Unibersitatea, Apartado Postal 1072, 20080 San Sebastian (Spain); Garcia de Abajo, F.J. [Departamento Ciencias de la Computacion e Inteligencia Artificial, Facultad de Informatica, Universidad del Pais Vasco/Euskal Herriko Unibersitatea, Apartado Postal 649, 20080 San Sebastian (Spain); Echenique, P.M. [Departamento Fisica de Materiales, Facultad de Quimicas, Universidad del Pais Vasco/Euskal Herriko Unibersitatea, Apartado Postal 1072, 20080 San Sebastian (Spain)

    1996-05-01

    A parameter-free model is presented to study the energy loss of fast protons specularly reflected from metal surfaces. The contributions to the energy loss from excitation of valence-band electrons and ionization of localized target-atom electronic states are calculated separately. The former is calculated from the induced surface wake potential using linear response theory and the specular-reflection model, while the latter is calculated in the first Born approximation. The results obtained are in good agreement with available experimental data. However, the experimental qualitative trend of the energy loss as a function of the angle of incidence is obtained when the valence-band electron model is replaced by localized target atom electron states, though with a worse quantitative agreement. {copyright} {ital 1996 The American Physical Society.}

  1. Evaporation residues produced in spallation of 208Pb by protons at 500A MeV

    Audouin, L; Armbruster, P; Benlliure, J; Bernas, M; Boudard, A; Casarejos, E; Czajkowski, S; Enqvist, T; Fernandez-Dominguez, B; Jurado, B; Legrain, R; Leray, S; Mustapha, B; Pereira, J; Pravikoff, M; Rejmund, F; Ricciardi, M V; Schmidt, K H; Stéphan, C; Taieb, J; Volant, C; Wlazlo, W

    2006-01-01

    The production cross sections of fragmentation-evaporation residues in the reaction Pb+p at 500A MeV have been measured using the inverse-kinematics method and the FRS spectrometer (GSI). Fragments were identified in nuclear charge using ionisation chambers. The mass identification was performed event-by-event using the B-rho - TOF - Delta-E technique. Although partially-unresolved ionic charge states induced an ambiguity on the mass of some heavy fragments, production rates could be obtained with a high accuracy by systematically accounting for the polluting ionic charge states. The contribution of multiple reactions in the target was subtracted using a new, partly self-consistent code. The isobaric distributions are found to have a shape very close to the one observed in experiments at higher energy. Kinematic properties of the fragments were also measured. The total and the isotopic cross sections, including charge-pickup cross sections, are in good agreement with previous measurements. The data are discus...

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

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

    2014-01-01

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

  3. Investigation of total ionizing dose effect and displacement damage in 65 nm CMOS transistors exposed to 3 MeV protons

    Ding, Lili, E-mail: lili03.ding@gmail.com [Department of Information Engineering, Padova University, Via Gradenigo 6/B, 35131 Padova (Italy); INFN, Padova, Via Marzolo 8, 35131 Padova (Italy); Gerardin, Simone [Department of Information Engineering, Padova University, Via Gradenigo 6/B, 35131 Padova (Italy); INFN, Padova, Via Marzolo 8, 35131 Padova (Italy); Bagatin, Marta [Department of Information Engineering, Padova University, Via Gradenigo 6/B, 35131 Padova (Italy); Bisello, Dario [Department of Physics and Astronomy, Padova University, Via Marzolo 8, 35131 Padova (Italy); INFN, Padova, Via Marzolo 8, 35131 Padova (Italy); Mattiazzo, Serena [Department of Physics and Astronomy, Padova University, Via Marzolo 8, 35131 Padova (Italy); Paccagnella, Alessandro [Department of Information Engineering, Padova University, Via Gradenigo 6/B, 35131 Padova (Italy); INFN, Padova, Via Marzolo 8, 35131 Padova (Italy)

    2015-10-01

    The paper reports the 65 nm CMOS transistors exposed to 3 MeV protons to study the total ionizing dose (TID) effect and displacement damage (DD). The proton fluence of 7×10{sup 14} p/cm{sup 2} is equivalent to 9.5 MGy(SiO{sub 2}) total dose and 7.7×10{sup 15} n/cm{sup 2} 1 MeV neutron equivalent fluence. Under this unprecedented hostile environment, we observed that the degradation of 65 nm CMOS transistors was mainly due to TID effect. Additional results from 10 keV X-ray irradiation implied no visible DD-induced degradation could be observed even for this extremely high proton fluence.

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

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

    2010-07-15

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

  5. Mechanical properties and microstructures of copper, gold and palladium single crystals irradiated with 600 MeV protons

    In the present work, the defect microstructures and hardening effects produced by 600 MeV proton irradiation in Cu, Pd and Au single crystals have been studied at room temperature. The defect microstructures in the irradiated Cu have been investigated by using transmission electron microscopy (TEM) in a dose range from 9.7x10-4 to 4.6x10-2 dpa. It has been observed that about 90% of the total defect clusters are stacking fault tetrahedra (SFT's). This fraction is independent of the thickness of the foil up to about 130 nm. The irradiation defect cluster densities obtained are in agreement with previous published results of high energy proton irradiation. With the present data at medium doses, the dose dependence of the defect cluster density, in high energy proton irradiated Cu, has been well established. A comparison between the results of Cu irradiated with high energy protons, fusion neutrons and fission neutrons indicates that there is no difference in defect cluster densities produced by these particle irradiations when the results are compared on the basis of dpa. The data compiled can be fitted within a band which shows that the defect cluster density starts to saturate at a value of about 4x1023 m-3. A large transition dose range between the linear dependence to the saturation is located between 3x10-3 and 1x10-1 dpa. The defect cluster size distribution measured under weak beam dark field (WBDF) imaging conditions with (g,6g) (WBDF(g,6g)), g=200, shows that the most probable size is between 1.5 and 2 nm and the mean size is about 2 nm independent of the dose. This result is also in agreement with published results. The defect structure in Au at dose of 1.1x10-1 dpa has been observed. It shows that about 85% of the total defect clusters are SFT's. There are no grouped defect clusters, which may probably be due to the fact that the defect cluster density (5.1x1023) has already saturated at this high dose. The most probable defect cluster size is between 2

  6. The Elemental Analysis of Biological and Environmental Materials Using a 2MEV Proton Beam

    Arshed, Waheed

    Available from UMI in association with The British Library. A programme has been developed to simulate the proton induced x-ray emission (PIXE) spectra and its uses have been described. The PIXE technique has been applied to the analysis of new biological reference materials which consist of IAEA human diet samples and NIST leaf samples. Homogeneity of these and two existing reference materials, IAEA soil -7 and Bowen's kale, has also been determined at the mug scale. A subsample representative of a material is ascertained by determination of sampling factors for the elements detected in the material. Proton induced gamma-ray emission (PIGE) analysis in conjunction with PIXE has been employed to investigate F and other elemental concentrations found in human teeth samples. The mean F concentration in enamel and dentine parts of teeth followed an age dependent model. Concentrations of Ca and P were found to be higher in the enamel than in the dentine. Analysis of blood and its components in the study of elemental models in sickle cell disease in Nigerians has been carried out. Comparisons revealed that Cl, Ca and Cu were at higher levels whereas K, Fe, Zn and Rb were at lower levels in the whole blood of the sicklers compared to controls. Similar results were obtained for the erythrocytes except that Br was found at higher concentration in erythrocytes of the sicklers. Higher concentrations of Cl, K, Fe and Cu were also observed in plasma of the sicklers compared to controls. PIXE and scanning electron microscopy (SEM) were used in the characterization of the Harmattan dust particulates collected at Kano and Ife. Most of the elements were found to be at higher concentrations as compared to those found in Recife (Brazil) and Toronto (Canada). The value of total suspended particulate was above the relevant national air quality standards. PIXE in conjunction with Rutherford backscattering spectrometry and instrumental neutron activation analysis was employed in the

  7. Attenuation analysis of neutrons and photons generated by 52-MeV protons transmitted through shielding materials

    Attenuation of neutrons and photons transmitted through grahite, iron, water and ordinary concrete assemblies were studied using gold foils for thermal neutron and an NE-213 organic scintillation detector with an (n-γ) discrimination technique for spectral measurements. Source neutrons and photons were produced by 52-MeV proton bombardment of a 21.4-mm-thick graphite target placed in front of the assembly. The distributions of the light output from the scintillator were unfolded by the revised FERDO code. These experimental results were used as benchmark data on neutron and photon penetration by neutrons energy above 15MeV. Multigroup Monte Carlo, one-dimensional ANISN and two-dimensional DOT-3.5 transport calculations were performed with the DLC-58/HELLO group cross sections to compare with the measurement and to evaluate the cross sections. The DOT code was also used for the estimation of room-scattered neutron and photon contribution to the measured spectra. The results of the ANISN calculation of neutrons and the three-dimensional Monte Carlo calculation agreed with the experimental values except for high energy neutrons transmitted through water and graphite. The agreement of both calculations was well within the accuracy of 7% in the measured attenuation coefficients. For photons, the ANISN calculation gave >20% overestimation of the attenuation coefficients in the case of deep penetration through the medium for which the photon mean-free-path is shorter than that of neutrons, such as in iron and concrete. The result of the DOT calculation of neutrons down to thermal energy agreed well with the gold foil measurement in the absolute value. (author)

  8. Stopping of 236 keV - 3.019 MeV protons in mylar and polypropylene films

    Damache, S.; Ouichaoui, S.; Belhout, A.; Medouni, A.; Toumert, I.

    2004-10-01

    The stopping powers of polypropylene and mylar polymers for protons have been accurately measured over the energy intervals Ep=(0.352-3.009) MeV and Ep=(0.236-3.019) MeV, respectively. Ab initio calculations using the Sigmund-Schinner binary collision theory for electronic stopping yielded S( E) values fairly consistent with the measured data that show no noticeable deviations from the Bragg-Kleeman additivity rule. The data have also been analyzed in the framework of the modified Bethe-Bloch theory assuming additivity. Values of the mean excitation and ionization potential, I, and of the Barkas parameter, b, have been deduced for the two polymers and for their (C, O) atomic constituents by adopting values of these parameters recommended in the ICRU-49 report for the H element. Thus, the respective I-values {(56.90 ± 0.72) eV, (79.92 ± 1.30) eV} for the two polymers and the same b-value 1.39 for their (C, O) atomic constituents have been determined by adopting for H the value b=1.8, while the I-values {(81.73 ± 1.38) eV, (109.46 ± 6.55) eV} have been deduced for the (C, O) constituents by adopting for H the value I=19.2 eV. Priorily, the shell, Barkas and Bloch corrections to the calculated S( E) values have been evaluated for both polymers over the explored respective energy ranges. The obtained results are discussed in comparison with previous ones when reported in the literature to our knowledge.

  9. Performance degradation of Si pin photodiodes, used as particle detectors, under 2 MeV proton irradiation

    Complete text of publication follows. Nowadays high quality Si pin photodiodes are cheap and reliable alternatives to nuclear semiconductor detectors for a wide range of application, especially for charged particle detection. Normal silicon with low oxygen content, however, is known as having low radiation tolerance. Therefore, the performance degradation of Hamamatsu S-5821 diodes has been investigated as a function of fluence for a series of ions. Selected areas of a photodiode were irradiated with various fluences of 2 MeV protons in the range of 1 x 109 - 5 x 1011 ion/cm2 without applying any bias. In order to investigate the impact of the irradiation on the particle detection response of the diode the radiation induced changes were measured with IBIC mapping using also 2 MeV protons in a wide range of reverse bias, from 0 to 100 V in logarithmic steps. The major influence of the irradiation is the decrease of the charge collection efficiency (CCE), i.e. the shift of the spectral peak position towards lower energies, and the increase of the dispersion of CCE, i.e. the widening of the spectral peaks, in other words the increase of the FWHM values, Δ. Since within the irradiated regions these quantities show strong position dependence due to boundary effect, the evaluation of the experimental data was restricted to the central homogenous parts. Quantitative empirical relationships above 10 V bias for the radiation induced contributions to the CCE and FWHM have been deduced as follows [1]: δ(CCE)rad = (-3.3 ± 0.5) x 10-13 Φ[cm-2]/U[V] Δrad[keV ] = (4 ± 1.5) x 10-5 √Φ[cm-2]/U[V] These contributions add linearly to irradiation free CCE, and quadratically to FWHM values, respectively. Since the effect of the irradiation - both on CCE and FWHM - is inversely proportional to the applied bias voltage, it can be significantly reduced by applying the possible highest bias without breakdown or increase of electrical noises due to increased leakage current. In this

  10. Evaluation of 10MeV proton irradiation on 5.5 Mpixel scientific CMOS image sensor

    Vu, Paul; Fowler, Boyd; Rodricks, Brian; Balicki, Janusz; Mims, Steve..; Li, Wang

    2010-10-01

    We evaluate the effects of 10 MeV proton irradiation on the performance of a 5.5 Mpixel scientific grade CMOS image sensor based on a 5T pixel architecture with pinned photodiode and transfer gate. The sensor has on-chip dual column level amplifiers and 11-bit single slope analog to digital converters (ADC) for high speed readout and wide dynamic range. The operation of the sensor is programmable and controlled by on-chip digital control modules. Since the image sensor features two identical halves capable of operating independently, we used a mask to expose only one half of the sensor to the proton beam, leaving the other half intact to serve as a reference. In addition, the pixel array and the digital logic control section were irradiated separately, at dose rates varying from 4 rad/s to 367 rad/s, for a total accumulated dose of 146 krad(Si) to assess the radiation effects on these key components of the image sensor. We report the resulting damage effects on the performance of the sensor including increase in dark current, temporal noise, dark spikes, transient effects and latch-up. The dark signal increased by about 55 e-/pixel after exposure to 14 krad (Si) and the dark noise increased from about 2.75e- to 6.5e-. While the number of hot pixels increased by 6 percent and the dark signal non uniformity degraded, no catastrophic failure mechanisms were observed during the tests, and the sensor did not suffer from functional failures.

  11. Corrosion of target and structural materials in water irradiated by an 800 MeV proton beam

    Radiation enhanced, aqueous corrosion of solid neutron-targets such as tungsten or tantalum, or target cladding or structural materials such as superalloys and stainless steels, is a significant concern in accelerator-driven transmutation technologies. In this paper we briefly describe our current methods for control and in situ monitoring of corrosion in accelerator cooling water loops. Using floating, electrochemical impedance spectroscopy (EIS), we have measured the corrosion rates of aluminum 6061, copper, Inconel 718, and 304L stainless steel in the flow loop of a water target irradiated by a μamp, 800 MeV proton beam. Impedance spectroscopy allows us to model the corrosion process of a material as an equivalent electrical circuit. Thus the polarization resistance, which is inversely proportional to the corrosion rate, can be extracted from the frequency response of a metal specimen. During a three month period, without the use of corrosion mitigation techniques, we observed increases of several orders of magnitude in the water conductivity and the corrosion rates. The increase in corrosion is at least partially attributed to a build up of peroxide in our pseudo-closed loop system. In this paper we also briefly describe our second generation experiments, scheduled to begin in late 1996. In these experiments we plan to measure the corrosion rates of tungsten, tantalum, Inconel 718, 316L and 304L stainless steel, HT-9 austenitic stainless steel, and aluminum 5053. Two or three electrode probes of each material are being placed directly in the proton beam, in a high neutron flux region, or a significant distance from the high radiation area. We will be measuring corrosion rates, changes in pH and conductivity, and we will be establishing parameters for filtration and mitigation of corrosion. We will also discuss our ideas for making in situ measurements of water radiolysis using optical and laser diagnostic techniques

  12. The depth-dependent radiation response of human melanoma cells exposed to 65 MeV protons

    Radiation therapy with positively charged particles implies that the Bragg peak be spread out ot deliver a homogeneous dose to the tumour. The spread-out Bragg peak (SOBP) has a higher linear energy transfer (LET) than the entrance beam. In addition, there is an LET gradient from proximal to distal SOBP. The aim of this study is to find out whether these small LET variations lead to differences in radiation response. Human melanoma cells (CAL4) were exposed to 65 MeV proton beams produced by the cyclotron Medicyc at five different positions: 2mm depth corresponding to the entrance, 15, 20, 25 and 26.8mm depth corresponding to four different positions in the half-modulated SOBP. Survival differences were observed at high doses; they were statistically significant at a dose of 8 Gy. With respect to the entrance position (2mm), the relative biological effectiveness (RBE) at 1% survival was 1.09, 1.12, 1.19 and 1.27 at 15, 20, 25 and 26.8mm in the SOBP, respectively. Whereas RBE values in the SOBP greater than 1.0 relative to the entrance beam represent a small biological advantage to be added to the well-known physical advantage of high energy proton beams; the RBE gradient along the SOBP would imply that the distal end of the tumour would receive a higher biologically equivalent dose than the proximal end, despite a homogeneous physical dose, especially at the high doses per fraction given in ocular melanomas. (author)

  13. Generation of energetic (>15 MeV) neutron beams from proton- and deuteron-driven nuclear reactions using short pulse lasers

    A roadmap is proposed for the production of high-energy (>15 MeV) neutrons using short pulse lasers. Different approaches are suggested for the two limiting cases of small (E1 ≪ Q) and large (E1 ≫ Q) projectile energies E1 depending on the Q-value of the nuclear reaction. The neutron fluence from many converter materials is evaluated for two projectiles: protons and deuterons. We found profound differences between proton- and deuteron-driven reactions with regard to both converter material and generated neutron fluence. The optimum converter material for deuteron-driven reactions is low-Z elements such as Li and Be, while for proton-driven reactions the converter material is not critical. For a projectile energy of 50 MeV the deuteron-driven reactions are two orders of magnitude more efficient compared to the proton-driven reactions. Two-dimensional particle-in-cell simulations have been performed for laser pulses with peak intensity 3 × 1020 W cm−2, pulse duration 40 fs, spot size 5 µm and energy 3 J interacting with ultrathin (0.1 µm) CD foil. The calculated deuteron beam is highly directional along the laser propagation direction with maximum energy of 45 MeV. The interaction of the deuteron beam with a lithium converter and the production of neutrons is modeled using a Monte Carlo code. The computed neutron spectra show that a forward directed neutron beam is generated with an opening angle of ∼1 sr, maximum energy of 60 MeV and a fluence in the forward direction 1.8 × 108 n sr−1, ∼20% of which are with energy above 15 MeV. (paper)

  14. Generation of energetic (>15 MeV) neutron beams from proton- and deuteron-driven nuclear reactions using short pulse lasers

    Petrov, G. M.; Higginson, D. P.; Davis, J.; Petrova, Tz B.; McGuffey, C.; Qiao, B.; Beg, F. N.

    2013-10-01

    A roadmap is proposed for the production of high-energy (>15 MeV) neutrons using short pulse lasers. Different approaches are suggested for the two limiting cases of small (E1 ≪ Q) and large (E1 ≫ Q) projectile energies E1 depending on the Q-value of the nuclear reaction. The neutron fluence from many converter materials is evaluated for two projectiles: protons and deuterons. We found profound differences between proton- and deuteron-driven reactions with regard to both converter material and generated neutron fluence. The optimum converter material for deuteron-driven reactions is low-Z elements such as Li and Be, while for proton-driven reactions the converter material is not critical. For a projectile energy of 50 MeV the deuteron-driven reactions are two orders of magnitude more efficient compared to the proton-driven reactions. Two-dimensional particle-in-cell simulations have been performed for laser pulses with peak intensity 3 × 1020 W cm-2, pulse duration 40 fs, spot size 5 µm and energy 3 J interacting with ultrathin (0.1 µm) CD foil. The calculated deuteron beam is highly directional along the laser propagation direction with maximum energy of 45 MeV. The interaction of the deuteron beam with a lithium converter and the production of neutrons is modeled using a Monte Carlo code. The computed neutron spectra show that a forward directed neutron beam is generated with an opening angle of ˜1 sr, maximum energy of 60 MeV and a fluence in the forward direction 1.8 × 108 n sr-1, ˜20% of which are with energy above 15 MeV.

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

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

    2015-10-01

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

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

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

    2016-07-01

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

  17. Annealing characteristics of amorphous silicon alloy solar cells irradiated with 1.00 MeV protons

    Abdulaziz, Salman S.; Woodyard, James R.

    1991-01-01

    Amorphous Si:H and amorphous Si sub x, Ge sub (1-x):H solar cells were irradiated with 1.00 MeV proton fluences in the range of 1.00E14 to 1.25E15 cm (exp -2). Annealing of the short circuit current density was studied at 0, 22, 50, 100, and 150 C. Annealing times ranged from an hour to several days. The measurements confirmed that annealing occurs at 0 C and the initial characteristics of the cells are restored by annealing at 200 C. The rate of annealing does not appear to follow a simple nth order reaction rate model. Calculations of the short-circuit current density using quantum efficiency measurements and the standard AM1.5 global spectrum compare favorably with measured values. It is proposed that the degradation in J sub sc with irradiation is due to carrier recombination through the fraction of D (o) states bounded by the quasi-Fermi energies. The time dependence of the rate of annealing of J sub sc does appear to be consistent with the interpretation that there is a thermally activated dispersive transport mechanism which leads to the passivation of the irradiation induced defects.

  18. Gamma strength function and level densities of $^{208}$Pb from forward-angle proton scattering at 295 MeV

    Bassauer, S; Tamii, A

    2016-01-01

    Gamma strength functions (GSFs) and level densities (LDs) are essential ingredients of statistical nuclear reaction theory with many applications in astrophysics, reactor design, and waste transmutation. The aim of the present work is a test of systematic parametrizations of the GSF recommended by the RIPL-3 data base for the case of $^{208}$Pb. The upward GSF and LDs in $^{208}$Pb are compared to gamma decay data from an Oslo-type experiment to examine the validity of the Brink-Axel (BA) hypothesis. The E1 and M1 parts of the total GSF are determined from high-resolution forward angle inelastic proton scattering data taken at 295 MeV at RCNP, Osaka, Japan. Total LDs in $^{208}$Pb are derived from $1^-$ LDs extracted with a fluctuation analysis in the energy region of the isovector giant dipole resonance. The E1 GSF is compared to parametrizations recommended by the RIPL-3 data base showing systematic deficiencies of all models in the energy region around neutron threshold. The new data for the poorly known s...

  19. Study of radiation damage caused by 23MeV protons on Multi-Pixel Photon Counter (MPPC)

    The automatic gain control system (AGC) is designed to continuously monitor and automatically control the gain of the phoswich detectors of the Hard X-ray Modulation Telescope (HXMT). It consists of a 241Am radioactive source distributed within a plastic scintillator (BC408) viewed by Multi-Pixel Photon Counter (MPPC). To verify the feasibility of application in space experiments, four MPPCs (S10362-33-050C) from Hamamatsu were irradiated using a beam of 23MeV protons with flux 1.0×108pcm-2, 2.0×108pcm-2, 4.0×108pcm-2 and 1.0×1010pcm-2. The leakage current of irradiated MPPC samples is found to increase linearly with total dose due to radiation damage. The device has completely lost its photon-counting capability when irradiated up to 13.6Gy. The pulse-height resolution has deteriorated hardly after irradiation and couldn't work with more than 450Gy, where the measured sample has been illuminated with a few hundred photons by the 241Am radioactive source. (author)

  20. Production of 81Rb/sup 81m/Kr generators with 60-MeV protons at BLIP

    By bombarding natural krypton gas with approx. 63 MeV protons, 81Rb is formed by (p,4n) reaction from high abundance 84Kr (57%) as well as some additional contribution from 83Kr (11.5%) and 82Kr (11.6%) by (p,3n) and (p,2n) reactions, respectively. The production rate of 81Rb is typically 1.5 mCi/μAh. This production rate is sufficient to create up to several hundred millicuries per run if necessary, enough for several high activity 81Rb/sup 81m/Kr generators. Presently generators that deliver 10 to 20 mCi to the lungs are produced weekly for on-site use. The only other important activity in the solution is Rb-82m (6.4 hr). Small amounts of Br-76 (16.1 hr), Br-77 (57 hr), Br-82 (35.5 hr), Rb-83 (86.2 d), and Rb-84 (33 d) were also present. The bromine impurities pose no problem since they are not trapped on the generator. Rb-82m and Rb-84 decay to stable Kr-82 and Kr-84 in the generator and do not interfere with Kr-81m studies

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

    Garrido, E.; Duchemin, C.; Guertin, A.; Haddad, F.; Michel, N.; Métivier, V.

    2016-09-01

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

  2. Spectroscopic study of 206,207,208Pb isotopes by high resolution analysis of 24.5 MeV proton scattering

    206,207,208pb have been studied by 24.5 MeV proton inelastic scattering with a resolution of 20 keV. The angular distributions of the differential cross-sections corresponding to the different excited levels have been measured in a large angular region and analysed with the DWBA.This work shows that it exists between 4 and 5 MeV of excitation energy some strongly excited levels corresponding to transfer momenta l = 2, 4, 6 and 8. The single particle-hole models do not explain these states; so it will probably be necessary to introduce some several particle - hole configurations. (author)

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

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

  4. Investigation of the Stability and 1.0 MeV Proton Radiation Resistance of Commercially Produced Hydrogenated Amorphous Silicon Alloy Solar Cells

    Lord, Kenneth R., II; Walters, Michael R.; Woodyard, James R.

    1994-01-01

    The radiation resistance of commercial solar cells fabricated from hydrogenated amorphous silicon alloys is reported. A number of different device structures were irradiated with 1.0 MeV protons. The cells were insensitive to proton fluences below 1E12 sq cm. The parameters of the irradiated cells were restored with annealing at 200 C. The annealing time was dependent on proton fluence. Annealing devices for one hour restores cell parameters for fluences below 1E14 sq cm fluences above 1E14 sq cm require longer annealing times. A parametric fitting model was used to characterize current mechanisms observed In dark I-V measurements. The current mechanism were explored with irradiation fluence, and voltage and light soaking times. The thermal generation current density and quality factor increased with proton fluence. Device simulation shows the degradation in cell characteristics may be explained by the reduction of the electric field in the intrinsic layer.

  5. Determination of proton size from pi sup + p and pi sup - p scattering at T subpi sub sup+- = 277-640 MeV

    Haque, S; Rahman, M A; Rahman, S N; Rana, M M

    2003-01-01

    The pion-nucleon interaction above the DELTA (1232) resonance and in the region of low-lying pion-nucleon resonances is studied. pi sup+-p elastic scattering at T subpi sub sup+-1% = 277 - 640 MeV characterized by diffraction maxima and minima has been analyzed through the strong absorption model due to Frahn and Venter. The proton radius is determined from the best fit values of the cut-off angular momentum to be 0.85 fm with a spread of 0.15 fm. The higher energy pions scan a lower value while the lower energy pions yield a higher value for the size of the proton. The energy averaged radius of the proton size of 0.85 fm obtained in the present analysis is in excellent agreement with proton charge radius of 0.86 fm quoted in the literature.

  6. Determination of proton size from π+p and π-p scattering at Tπ± = 277-640 MeV

    The pion-nucleon interaction above the Δ (1232) resonance and in the region of low-lying pion-nucleon resonances is studied. π±p elastic scattering at Tπ±1% = 277 - 640 MeV characterized by diffraction maxima and minima has been analyzed through the strong absorption model due to Frahn and Venter. The proton radius is determined from the best fit values of the cut-off angular momentum to be 0.85 fm with a spread of 0.15 fm. The higher energy pions scan a lower value while the lower energy pions yield a higher value for the size of the proton. The energy averaged radius of the proton size of 0.85 fm obtained in the present analysis is in excellent agreement with proton charge radius of 0.86 fm quoted in the literature. (author)

  7. Measurement of LET (linear energy transfer) spectra using CR-39 at different depths of water irradiated by 171 MeV protons: A comparison with Monte Carlo simulation

    Sahoo, G. S.; Tripathy, S. P.; Molokanov, A. G.; Aleynikov, V. E.; Sharma, S. D.; Bandyopadhyay, T.

    2016-05-01

    In this work, we have used CR-39 detectors to estimate the LET (linear energy transfer) spectrum of secondary particles due to 171 MeV proton beam at different depths of water including the Bragg peak region. The measured LET spectra were compared with those obtained from FLUKA Monte Carlo simulation. The absorbed dose (DLET), dose equivalent (HLET) were estimated using the LET spectra. The values of DLET and HLET per incident proton fluence were found to increase with the increase in depth of water and were maximum at Bragg peak.

  8. Experimental study with Diogene of protons produced in α-nucleus reactions between 200 and 800 MeV by nucleon

    The detection set Diogene situated on a measurement line of the Saturne accelerator allows the study of alpha-nuclei collisions among others, at relativistic energies. Such collisions between 200 and 800 MeV by nucleon are studied here. The experimental device is presented; trajectory reconstruction and identification are detailed; after some recalls on the models known at these energies and the two codes used, the data analysis with lead, copper, carbon targets is limited to protons and pseudo-protons produced in the reactions. The discussion is centered on previsions with cascades. Global variations are introduced such as conicity and forwardness

  9. Nuclear data evaluations of neutron and proton incidence on Zr, Nb, and W for energy up to 200 MeV

    Neutron and proton nuclear data were evaluated on Zr, Nb, and W for energy up to 200 MeV. To execute optical model calculations, spherical optical potentials were developed to reproduce experimental data for many elements. The GNASH nuclear model code was used to evaluate light-particle production cross sections. For neutron emission, giant resonance correction came to be performed in the code system. (author)

  10. Nucleation of Helium Bubbles on Dislocations, Dislocation Networks and Dislocation in Grain Boundaries during 600 MeV Proton Irradiation of Aluminium

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

    1984-01-01

    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....

  11. Effects of 600 MeV proton irradiation on nucleation and growth of precipitates and helium bubbles in a high-purity Al-Mg-Si alloy

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

    Solution treated specimens of a high-purity Al-0.75%Mg-0.42%Si alloy were irradiated with 600 MeV protons at 150 and 240°C to a dose level of 0.47 and 0.55 dpa, respectively. Mg2Si-type precipitates formed during irradiation at 150 and 240°C; at 240°C, however, a large number of precipitates seem...

  12. Towards a fully microscopic model of proton-nucleus scattering. Single shot predictions of elastic and inelastic scattering of protons from 65 to 200 MeV

    Effective two nucleon (NN) interactions in the nuclear medium and for protons with energies in the range 65 to 200 MeV, have been defined from an accurate mapping of NN g matrices obtained by solving the Brueckner-Bethe-Goldstone (BBG) equations for infinite nuclear matter at various Fermi momenta to 1.5 fm-1. Then, by folding those effective interactions with the ground state one body (nucleon) density matrix elements (OBDME) of nuclei, we have defined proton-nucleus optical potentials. Those density matrix elements have been obtained with diverse (shell) models for the structure with very large basis space calculations used for light nuclei (to 28Si). The derived optical potentials are nonlocal, complex, and vary with energy and and have been used in the integro-differential form of the Schroedinger equation to predict differential cross sections, analyzing powers and, in some cases, spin rotations for elastic scattering. Excellent results have been obtained for many energies and for scattering from targets ranging from 4He to 208Pb and with but single shot calculations. Fits to the scattering date are very good when the ground state density matrix elements and single nucleon bound states are fixed by analyses of the form factors from elastic electron scattering. A key feature of our analysis method is that it is predictive. No adjustment of any element is made to improve fits to data. The relative motion wave functions that one finds with the nonlocal optical potentials then have been used as the distorted waves in distorted wave approximation (DWA) studies of select inelastic scattering events with light mass nuclei, in particular 12C and lithium isotopes. The same effective NN interactions were used as the transition operators in those calculations and the relevant nuclear spectroscopy (OBDME for inelastic scattering) have been found from large basis shell model evaluations of the nuclear structure; wave functions of which give good descriptions for many

  13. Solar proton event of April 16, 1970. 3. Evolution of pitch angle distribution as < or approx. =1-MeV protons propagate into the high-latitude magnetotail

    The solar proton event of April 16, 1970 was monitored by Vela satellites, of orbit r=18 R/sub E/, in the solar wind and high-latitude magnetotail (lobe). Intensity structure at < or approx. =1 MeV indicates a delay of 85--102 min in access of protons to near the center of the north lobe, corresponding to entry points at 340--370 R/sub E/ from the earth. In three sequential periods, of 16, 181, and 124 min duration, the average intensity in the north lobe was lower, higher, and lower, respectively, than that in interplanetary space, by factors which varied from 2 to 5. These reversals were a consequence of reversals in field-aligned anisotropy in interplanetary space, the interplanetary magnetic field remaining southward. Pitch angle distributions were measured in three dimensions in interplanetary space and in the north lobe. In the lobe the distributions were essentially isotropic at r=18 R/sub E/. Comparison is made with theoretical propagation of solar particles along field lines in an open tail model, under the following conditions along a trajectory: (1) adiabatic motion all the way (Liouville theorem) : the 'adiabatic access model' (2) isotropization at the magnetopause followed by adiabatic motion: the 'nonadiabatic access model'. Neither mode of access explains the observations adequately. A hybrid mode is proposed, in which a minimal amount of scattering occurs as particles enter the tail, followed by amplification (attenuation) of intensity as the pitch distribution is transformed to near 18 R/sub E/ in the favored (unfavored) lobe. In this mode a large part of the isotropization at Vela orbit is accomplished by the Liouville transformation, since particles entering the tail beyond approx. =100 R/sub E/ will see an increase in magnetic field by a factor of 3 as they propagate along the tail. The amount of scatter at the magnetopause is estimated to be Δμ (rms) =0.3, where μ is cosine of pitch angle

  14. HETC-3STEP calculations of proton induced nuclide production cross sections at incident energies between 20 MeV and 5 GeV

    For the OECD/NEA code intercomparison, nuclide production cross sections of 16O, 27Al, natFe, 59Co, natZr and 197Au for the proton incidence with energies of 20 MeV to 5 GeV are calculated with the HETC-3STEP code based on the intranuclear cascade evaporation model including the preequilibrium and high energy fission processes. In the code, the level density parameter derived by Ignatyuk, the atomic mass table of Audi and Wapstra and the mass formula derived by Tachibana et al. are newly employed in the evaporation calculation part. The calculated results are compared with the experimental ones. It is confirmed that HETC-3STEP reproduces the production of the nuclides having the mass number close to that of the target nucleus with an accuracy of a factor of two to three at incident proton energies above 100 MeV for natZr and 197Au. However, the HETC-3STEP code has poor accuracy on the nuclide production at low incident energies and the light nuclide production through the fragmentation process induced by protons with energies above hundreds of MeV. Therefore, further improvement is required. (author)

  15. Nuclear charge distribution of fission products originated from fission of 238U nuclei induced by45-69 MeV protons

    Houshyar Noshad

    2007-12-01

    Full Text Available  Fission of 238U nuclei was performed by 45-69 MeV protons at the Cyclotron and Radioisotope Center of Tohoku University in Japan. The fission products originated in the reaction were identified by using gamma spectroscopy. The experimental data show that the charge distribution of isobar fission products follows a Gaussian distribution with a standard deviation independent of the selected mass number. The standard deviations were measured for the reaction 238U(p, f with 45, 55, 65 and 69 MeV protons. For Ep = 45 MeV, the standard deviation obtained from the experiment is in agreement with the existing data and satisfies the prediction of the Hauser-Feshbach statistical model. For other proton energies, measurement of this quantity has not been reported in the literature. The experimental results show that the value of standard deviation increases, when the excitation energy of the fissioning nucleus increases. Furthermore, the most probable charge was determined for the isobar fission products detected in the experiment. The results are consistent with the prediction of the minimum potential energy (MPE model. Moreover, the experimental data show that nuclear charge polarization occurs in the fission process.

  16. Sudden Intensity Increases and Radial Gradient Changes of Cosmic Ray MeV Electrons and Protons Observed at Voyager 1 beyond 111 AU in the Heliosheath

    Webber, W R; Cummings, A C; Stone, E C; Heikkila, B; Lal, N

    2011-01-01

    Voyager 1 has entered regions of different propagation conditions for energetic cosmic rays in the outer heliosheath beginning at a distance of about 111 AU from the Sun. This conclusion is based on the fact that the low energy 6-14 MeV galactic electron intensity suddenly increased by ~20% over a time period \\leg 10 days and the electron radial intensity gradient abruptly decreased from ~19%/AU to ~8%/AU at 2009.7 at a radial distance of 111.2 AU. A sudden radial gradient change was also observed at this time for >200 MeV protons. The gradients were constant during the time period before and after the electron increase. At about 2011.2 at a distance of 116.6 AU a second abrupt intensity increase was observed, this time for both electrons and protons. The increase for electrons was ~25% and occurred over a time period ~15 days or less. For >200 MeV protons the increase at this time was ~5% (unusually large) and occurred over a longer time period ~50 days. Between about 2011.2 and 2011.6, radial intensity grad...

  17. Microscopic model analyses of the elastic scattering of 65 MeV protons from targets of diverse mass

    Nonlocal coordinate space optical potentials for the scattering of 65 MeV protons from nuclei ranging in mass from 6Li to 238U have been defined by folding a complex, medium dependent effective interaction with the 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 nuclear structure information required in our folding model are the one body density matrix elements for the target and the single nucleon bound state wave functions that they weight. For light mass nuclei, very large basis shell model calculations have been made to obtain the one body density matrix elements. For medium and heavy mass nuclei, a very simple shell model prescription has been used. The bound state single particle wave functions that complete the nuclear density matrices are either Woods-Saxon or harmonic oscillator functions. The former are employed in most cases when large basis structure is available. For light nuclei (A ≤ 16) Woods-Saxon potential parameters and harmonic oscillators lengths are determined from fits to electron scattering form factors. For all other nuclei, we use harmonic oscillator functions with the oscillator lengths set from an A1/6 mass law. Using this microscopic model, optical potentials result from with differential cross sections, analyzing powers and spin rotations are found. In general the calculated results compare very well with data when the effective interactions are determined from a mapping of nucleon-nucleon g matrices. This is not the case when effective interactions built from a mapping of (free) t matrices are used. (authors)

  18. Characterization of the energy distribution of neutrons generated by 5 MeV protons on a thick beryllium target at different emission angles

    Neutron energy spectra at different emission angles, between 0° and 120° from the Be(p,xn) reaction generated by a beryllium thick-target bombarded with 5 MeV protons, have been measured at the Legnaro Laboratories (LNL) of the Italian National Institute for Nuclear Physics research (INFN). A new and quite compact recoil-proton spectrometer, based on a monolithic silicon telescope, coupled to a polyethylene converter, was efficiently used with respect to the traditional Time-of-Flight (TOF) technique. The measured distributions of recoil-protons were processed through an iterative unfolding algorithm in order to determine the neutron energy spectra at all the angles accounted for. The neutron energy spectrum measured at 0° resulted to be in good agreement with the only one so far available at the requested energy and measured years ago with TOF technique. Moreover, the results obtained at different emission angles resulted to be consistent with detailed past measurements performed at 4 MeV protons at the same angles by TOF techniques.

  19. Characterization of the energy distribution of neutrons generated by 5 MeV protons on a thick beryllium target at different emission angles

    Agosteo, S. [Politecnico di Milano, Dipartimento di Energia, Piazza Leonardo da Vinci 32, 20133 Milano (Italy)] [Istituto Nazionale di Fisica Nucleare, Sezione di Milano, via Celoria 16, 20133 Milano (Italy); Colautti, P., E-mail: paolo.colautti@lnl.infn.it [INFN, Laboratori Nazionali di Legnaro (LNL), Via dell' Universita, 2, I-35020 Legnaro (PD) (Italy); Esposito, J., E-mail: juan.esposito@tin.it [INFN, Laboratori Nazionali di Legnaro (LNL), Via dell' Universita, 2, I-35020 Legnaro (PD) (Italy); Fazzi, A.; Introini, M.V.; Pola, A. [Politecnico di Milano, Dipartimento di Energia, Piazza Leonardo da Vinci 32, 20133 Milano (Italy)] [Istituto Nazionale di Fisica Nucleare, Sezione di Milano, via Celoria 16, 20133 Milano (Italy)

    2011-12-15

    Neutron energy spectra at different emission angles, between 0 Degree-Sign and 120 Degree-Sign from the Be(p,xn) reaction generated by a beryllium thick-target bombarded with 5 MeV protons, have been measured at the Legnaro Laboratories (LNL) of the Italian National Institute for Nuclear Physics research (INFN). A new and quite compact recoil-proton spectrometer, based on a monolithic silicon telescope, coupled to a polyethylene converter, was efficiently used with respect to the traditional Time-of-Flight (TOF) technique. The measured distributions of recoil-protons were processed through an iterative unfolding algorithm in order to determine the neutron energy spectra at all the angles accounted for. The neutron energy spectrum measured at 0 Degree-Sign resulted to be in good agreement with the only one so far available at the requested energy and measured years ago with TOF technique. Moreover, the results obtained at different emission angles resulted to be consistent with detailed past measurements performed at 4 MeV protons at the same angles by TOF techniques.

  20. Measurements of proton induced γ-ray emission cross-sections on Mg from 1.0 to 3.0 MeV

    Sharifzadeh, N.; Kakuee, O.; Mohammadi, S.

    2016-04-01

    Differential cross-section of proton induced γ-ray emission from the reactions 24Mg(p,p‧γ)24Mg (Eγ = 1369 keV), 25Mg(p,p‧γ)25Mg (Eγ = 390, 585, 975 keV) and 26Mg(p,γ)27Al (Eγ = 1014 keV) were measured for proton energies from 1 to 3 MeV using a 60 μg/cm2 Mg target evaporated on a 40 μg/cm2 Ag thin film. The γ-rays were collected by a 50% relative efficiency HPGe detector placed at an angle of 90° with respect to the beam direction, while the backscattered protons were collected by an ion implanted Si detector placed at a scattering angle of 165°. Simultaneous collection of γ-ray and RBS spectra is a great advantage of this approach which makes differential cross-section measurements independent on the collected beam charge. Measured cross-section values were compared with the previously reported data in the literature. Absolute γ-ray differential cross-sections were obtained with an overall systematic uncertainty of about ±6% and statistical uncertainty of less than ±5% for proton energies higher than 2.24 MeV.

  1. Evidence of the Coulomb force effects in the cross sections of the deuteron-proton breakup at 130 MeV

    Kistryn, S; Bodek, K; Ciepal, I; Deltuva, A; Fonseca, A; Kalantar-Nayestanaki, N; Kis, M; Klos, B; Kozela, A; Mahjour-Shafiei, M; Micherdzinska, A; Sauer, P U; Stephan, E; Sworst, R; Zejma, J; Zipper, W; Kistryn, St.

    2006-01-01

    High precision cross-section data of the deuteron-proton breakup reaction at 130 MeV deuteron energy are compared with the theoretical predictions obtained with a coupled-channel extension of the CD Bonn potential with virtual Delta-isobar excitation, without and with inclusion of the long-range Coulomb force. The Coulomb effect is studied on the basis of the cross-section data set, extended in this work to about 1500 data points by including breakup geometries characterized by small polar angles of the two protons. The experimental data clearly prefer predictions obtained with the Coulomb interaction included. The strongest effects are observed in regions in which the relative energy of the two protons is the smallest.

  2. Shielding data for 100-250 MeV proton accelerators: Attenuation of secondary radiation in thick iron and concrete/iron shields

    Double differential distributions of neutrons produced by 100, 150, 200 and 250 MeV protons stopped in a thick iron target were calculated with the FLUKA Monte Carlo code at four emission angles: forward, 45 deg., transverse and 135 deg. backwards. The attenuation in thick iron shields of the dose equivalent due to neutrons, protons, photons and electrons was also calculated. The contribution to the total ambient dose equivalent from photons and protons is limited to a few percent at maximum. Source terms and attenuation lengths are given as a function of energy and emission angle, along with fits to the Monte Carlo data, for shallow depth and deep penetration in the shield. A brief discussion of simulations performed with composite iron/concrete shields is also given, showing the need for further investigations

  3. Analyses of stopping power measurements for 0.90-2.50 MeV protons and deuterons traversing Al 2O 3 targets

    Porter, L. E.

    2000-09-01

    Recently reported measurements of the stopping power of Al 2O 3 for 0.90-2.50 MeV protons and deuterons have been analyzed in terms of modified Bethe-Bloch theory. Values of the mean excitation energy ( I) and Barkas-effect parameter ( b) have been extracted from the data, yielding results for I and b, respectively, of 176.8 eV and 0.83 for protons, and of 182.7 eV and 1.02 for deuterons. These values of I exceed the additivity-based value by 32% for proton data and by 36% for deuteron data. Moreover, both extracted values of b lie well below the expected interval of 1.3-1.5.

  4. Response of human lymphocytes to proton radiation of 60 MeV compared to 250 kV X-rays by the cytokinesis-block micronucleus assay

    Particle radiotherapy such as protons provides a new promising treatment modality to cancer. However, studies on its efficacy and risks are relatively sparse. Using the cytokinesis-blocked micronucleus assay, we characterized response of human peripheral blood lymphocytes, obtained from health donors irradiated in vitro in the dose range: 0–4. 0 Gy, to therapeutic proton radiation of 60 MeV from AIC-144 isochronous cyclotron, by studying nuclear division index and DNA damage and compared them with X-rays. Peripheral blood lymphocytes show decreased ability to proliferate with increasing radiation doses for both radiation types, however, in contrast to X-rays, irradiation with protons resulted in a higher proliferation index at lower doses of 0.75 and 1.0 Gy. Protons are more effective in producing MN at doses above 1.75 Gy compared to X-rays. Dose–response curves for micronucleus incidence can be best described by a cubic model for protons, while for X-rays the response was linear. The differences in the energy spectrum and intracellular distribution of energy between radiation types are also apparent at the intracellular distribution of cytogenetic damage as seen by the distribution of various numbers of micronuclei in binucleated cells. Our studies, although preliminary, further contribute to the understanding of the mechanistic differences in the response of HPBL in terms of cellular proliferation and cytogenetic damage induced by protons and X-rays as well as intra-cellular distribution of energy and thus radiobiological effectiveness

  5. 5.5-MeV proton irradiation of a strained quantum-well laser diode and a multiple quantum-well broad-band LED

    The degradation under 5.5-MeV proton irradiation of two classes of quantum-well-based fiber-optic light sources was evaluated for satellite applications. The first was an InGaAs/GaAs strained-layer quantum-well (QW) laser; the second was a broad-band light-emitting diode (LED) based on dual asymmetric quantum wells in the InGaAs/GaAs/AlGaAs system. In contrast to earlier reports comparing bulk active-region heterostructure LEDs with similarly structured laser diodes, these QW LEDs were more tolerant of proton irradiation (-3dB power at ∼3x1013 protons/cm2) than the QW lasers (-3dB power at ∼3x1012 protons/cm2). The LEDs were operated far into gain saturation with a high-loss cavity structure, while the lasers were operated in a region where gain was more sensitive to current density. Therefore atomic displacement-related recombination sites had a greater detrimental effect upon the lasers than the LEDs. The lasers held constant slope efficiency, and current thresholds increased linearly with proton fluence, while both LED power and slope efficiency decreased with proton fluence. Similar damage factors were found to those predicted from a universal damage factor versus non-ionizing energy deposition relation reported by others, and appears to extend that relation to include these QW photonic devices

  6. The effects of 800 MeV proton irradiation on the corrosion of tungsten, tantalum, stainless steel, and gold

    Lillard, R.S.; Butt, D.P.; Kanner, G.; Daemen, L.

    1997-12-01

    Real time electrochemical data were acquired for tungsten, tantalum, stainless steel 304L, and gold targets during proton irradiation at the LANSCE Weapons Neutron Research Facility. The goal of this research was to establish a better understanding of the corrosion properties of materials as a function of proton irradiation and gain insight into the mechanism of the observed phenomena. The following electrochemical observations were made during proton irradiation of W, Ta, SS304, and Au: (1) the open circuit potential of all materials increased with increasing proton fluence; (2) the corrosion rate (at the OCP) of W and SS304 increased with increasing proton fluence; (3) the passive dissolution rate for SS304 and Ta decreased with increasing proton fluence; (4) the anodic dissolution rate for W increased with increasing proton fluence; (5) the pitting potential for SS304 increased with proton fluence, which is an indication that the material is less susceptible to pitting attack during irradiation.

  7. The effects of 800 MeV proton irradiation on the corrosion of tungsten, tantalum, stainless steel, and gold

    Real time electrochemical data were acquired for tungsten, tantalum, stainless steel 304L, and gold targets during proton irradiation at the LANSCE Weapons Neutron Research Facility. The goal of this research was to establish a better understanding of the corrosion properties of materials as a function of proton irradiation and gain insight into the mechanism of the observed phenomena. The following electrochemical observations were made during proton irradiation of W, Ta, SS304, and Au: (1) the open circuit potential of all materials increased with increasing proton fluence; (2) the corrosion rate (at the OCP) of W and SS304 increased with increasing proton fluence; (3) the passive dissolution rate for SS304 and Ta decreased with increasing proton fluence; (4) the anodic dissolution rate for W increased with increasing proton fluence; (5) the pitting potential for SS304 increased with proton fluence, which is an indication that the material is less susceptible to pitting attack during irradiation

  8. Measurement of proton polarization in the deuteron photodisintegration reaction on the linearly polarized photon beam in the energy range Eγ=290-420 MeV at angle Θpx=65 deg cms

    The results of measurement of proton polarization in the reaction plane (Pxz) and in the plane (Py) perpendicular to it, in the deuteron photodisintegration reaction in the photon energy range from 290 MeV to 420 MeV at proton escape angle in cms Θpx=65 deg, are presented. The results are compared with the predictions of theoretical calculations of the gradient-invariant model with account of dibaryon resonances. 6 refs.; 2 figs.; 1 tab

  9. Cross Sections for proton induced high energy $\\gamma$-ray emission (PIGE) in reaction $^{19}$F(p,$\\alpha\\gamma$)$^{16}$O at incident proton energies between 1.5 and 4 MeV

    Cabanelas, P; Fonseca, M; Galaviz, D; Henriques, A; Jesus, A P; Luís, H; Sánchez-Benítez, A; Santos, C; Silva, H; Teubig, P; Velho, P

    2016-01-01

    We have studied the high energy gamma-rays produced in the reaction $^{19}$F(p,$\\alpha\\gamma$)$^{16}$O for incident proton energies from 1.5 to 4.0 MeV over NaF/Ag and CaF$_2$/Ag thin targets in two different sets of data. Gamma-rays were detected with a High Purity Ge detector with an angle of 130$^{o}$ with respect to the beam axis. The cross-sections for the high energy gamma-rays of 6.129, 6.915 and 7.115 MeV have been measured for the whole group between 5 and 7.2 MeV with accuracy better than 10%. A new energy range was covered and more points are included in the cross-sections data base. Results are in agreement with previous measurements in similar conditions.

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

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

    2016-08-01

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

  11. Relative biological effectiveness (RBE) and oxygen enhancement ratio (OER) of neutron beams produced by 50 Mev deuterons and 34, 45, 65, 75 MeV protons in Vicia faba

    Variation of neutron RBE and OER, as a function of energy, was determined for differrent neutron beams produced at the cyclotron ''Cyclone'' of Louvain-la-Neuve. The biological system was growth inhibition in Vicia faba bean roots. RBE of neutron beams produced by bombarding a beryllium target by 34, 45, 65 and 75 MeV proton (2 cm thick polythene additional filter) was found equal to 1.15 +- 0.13, 1.02 +- 0.10, 0.85 +- 0.08 and 0.83 +- 0.09, for absorbed doses of 0.39 Gy, 0.44 Gy, 0.53 Gy and 0.54 Gy respectively. These doses correspond to 50 % growth inhibition. Neutrons produced by 50 MeV deuterons on beryllium are taken as reference. For the same beams, OER value are equal to 1.55 +- 0.13, 1.38 +- 0.12, 1.29 +- 0.12 and 1.41 +- 0.11 respectively. OER is equal to 1.60 +- 0.15 for neutrons produced by 50 MeV deuterons (P = 0.05)

  12. Construction of a BNCT facility using an 8-MeV high power proton linac in Ibaraki

    -MeV proton linac and of a beryllium-based neutron production target for the BNCT is progressing. (author)

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

    Yang, Jianqun; Li, Xingji; Liu, Chaoming; Ma, Guoliang

    2015-01-01

    The effects of 3 MeV proton irradiation for fluences of 3.5 × 1010 cm-2 to 3.1 × 1012 cm-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 × 1011 cm-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 × 1011 cm-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.

  14. Measurement of the stochastic radial dose distribution for a 30-MeV proton beam using a wall-less tissue-equivalent proportional counter.

    Tsuda, S; Sato, T; Ogawa, T

    2016-02-01

    The frequency distribution of the lineal energy, y, of a 30-MeV proton beam was measured as a function of the radial distance from the beam path, and the dosed mean of [Formula: see text] was obtained to investigate the radial dependence of [Formula: see text] A wall-less tissue-equivalent proportional counter, in a cylindrical volume with simulated diameters of 0.36, 0.72 and 1.44 µm was used for the measurement of y distributions, yf(y). The measured values of yf(y) summed in the radial direction agreed fairly well with the corresponding data taken from the microdosimetric calculations using the PHITS code. The [Formula: see text] value of the 30-MeV proton beam presented its smallest value at r = 0.0 and gradually increased with radial distance, and the [Formula: see text] values of heavy ions such as iron showed rapid decrease with radial distance. This experimental result demonstrated that the stochastic deposited energy distribution of high-energy protons in the microscopic region is rather constant in the core as well as in the penumbra region of the track structure. PMID:25956785

  15. Measurements of attenuation lengths through concrete and iron for neutrons produced by 800-MeV proton on tantalum target at ISIS

    Nunomiya, T; Wright, P; Nakamura, T; Kim, E; Kurosawa, T; Taniguchi, S; Sasaki, M; Iwase, H; Uwamino, Y; Shibata, T; Ito, S; Perry, D R

    2002-01-01

    A deep penetration experiment through a thick bulk shield was performed at an intense spallation neutron source facility, ISIS, of the Rutherford Appleton Laboratory (RAL), United Kingdom. ISIS is a 800 MeV-200 mu A proton accelerator facility. Neutrons are produced from a tantalum target, and are shielded with approximately 3-m thick steel and 1-m thick ordinary concrete. On top of the shield, we measured the neutron flux attenuation through concrete and iron shields, which were additionally placed up to 120-cm and 60-cm thickness, respectively, using activation detectors of graphite and bismuth. The attenuation lengths of concrete and iron for high-energy neutrons above 20 MeV were obtained from the sup 1 sup 2 C(n, 2n) sup 1 sup 1 C reaction of graphite.

  16. High precision absolute differential cross-section measurements for proton-proton elastic scattering at 491.9, 575.5, 641.6, 728.2, and 793.0 MeV

    The proton-proton absolute elastic differential cross section, σpp(θ), has been measured at incident proton beam energies of 491.9, 575.5, 641.6, 728.2, and 793.0 MeV at laboratory scattering angles of ∼15 degree to ∼42 degree with a total uncertainty on the order of 1%. The measurements were made at the Clinton P. Anderson Los Alamos Meson Physics Facility (LAMPF) and employed a new beam counting technique which provided a better overall beam normalization compared to previous experiments of this type. The cross section was measured with CH2 targets and a primary liquid, LH2, target to determine the uncertainties in some systematic corrections. Extreme care was taken to reduce individual systematic errors to less than 0.5%

  17. Measurement of Absolute Cross-Sections of Fission Induced by 156-MeV Protons, Using Mica as a Fission Fragment Detector

    The fission of elements of medium Z induced by 156-MeV protons is difficult to demonstrate, owing to the particularly small cross-section of the reaction. The detection of fission fragments by means of sheets of mica seemed to be a technique well suited to this type of experiment. In the sheets of synthetic mica that we used it was only the fission fragments that left microscopically identifiable traces. Moreover, these samples contain very few impurities likely to undergo fission, so practically no parasitic traces are observed. The targets consisted of metals of not less than 99.999% purity. We determined the absolute cross-sections.of fission induced by 156-MeV protons in the case of lanthanum (5 μb) and praseodymium (6 μb), and estimated those of cadmium, indium, tin and antimony (≤ 0.1 μb). The sheets of mica were placed on each side of the metal sheet. The kinetics of the reaction explain why more traces were found on the mica sheets placed on the from face. As thick targets were used to take account of self-absorption, we determined (in the case of uranium and gold) the ratio of yields between a thin target and a thick target, and then extrapolated our results to the other elements. We made checks by comparing the absolute cross-sections for fission (induced by 156-MeV protons) in uranium, bismuth, gold and tantalum, as obtained by this method, with those obtained by counters at this energy. The observed agreement was very good. (author)

  18. Characterization techniques for fixed-field alternating gradient accelerators and beam studies using the KURRI 150 MeV proton FFAG

    Sheehy, S L; Machida, S; Rogers, C; Prior, C R; Volat, L; Tahar, M Haj; Ishi, Y; Kuriyama, Y; Sakamoto, M; Uesugi, T; Mori, Y

    2015-01-01

    In this paper we describe the methods and tools used to characterize a 150 MeV proton scaling Fixed Field Alternating Gradient (FFAG) accelerator at Kyoto University Research Reactor Institute. Many of the techniques used are unique to this class of machine and are thus of relevance to any future FFAG accelerator. For the first time we detail systematic studies undertaken to improve the beam quality of the FFAG. The control of beam quality in this manner is crucial to demonstrating high power operation of FFAG accelerators in future.

  19. Nanoparticle formation in H2O/N-2 and H2O/Ar mixtures under irradiation by 20 MeV protons and positive corona discharge

    Imanaka, M.; Tomita, S.; Kanda, S.;

    2010-01-01

    To investigate the contribution of ions to gas nucleation, we have performed experiments on the formation of water droplets in H2O/N-2 and H2O/Ar gas mixtures by irradiation with a 20 MeV proton beam and by positive corona discharge. The size of the formed nanoparticles was measured using a...... positive and negative ions for the formation of nanosize droplets, which attract each other by Coulomb interactions, enhancing the collision frequency and leading to the formation of the 10 nm droplets....

  20. Neutron and proton optical potentials for 12C, 16O, 27Al, 56Fe, 90Zr and 208Pb up to 250 MeV

    In order to perform nuclear data evaluation without unphysical discontinuities, optical models should cover the whole mass and energy range of interest continuously. In this work, the best set of optical model parameters were obtained with energy dependent potential forms which incorporate effects of dispersion relationship for neutron and proton up to 250 MeV on 12C, 16O, 27Al, 56Fe, 90Zr and 208Pb. Applicability of adopting an identical geometrical factor for the real volume, imaginary volume and imaginary surface potentials has been investigated as well in the process of parameter search. (author)

  1. Relative biological effectiveness of the 60-MeV therapeutic proton beam at the Institute of Nuclear Physics (IFJ PAN) in Kraków, Poland

    Słonina, Dorota; Biesaga, Beata; Swakoń, Jan; Kabat, Damian; Grzanka, Leszek; Ptaszkiewicz, Marta; Sowa, Urszula

    2014-01-01

    Abstract The aim of the study was to determine the relative biological effectiveness (RBE) of a 60-MeV proton radiotherapy beam at the Institute of Nuclear Physics, Polish Academy of Sciences (IFJ PAN) in Kraków, the first one to operate in Poland. RBE was assessed at the surviving fractions (SFs) of 0.01, 0.1, and 0.37, for normal human fibroblasts from three cancer patients. The cells were irradiated near the Bragg peak of the pristine beam and at three depths within a 28.4-mm spread-out Br...

  2. Characterization techniques for fixed-field alternating gradient accelerators and beam studies using the KURRI 150 MeV proton FFAG

    Sheehy, S. L.; Kelliher, D. J.; Machida, S.; Rogers, C.; Prior, C. R.; Volat, L.; Haj Tahar, M.; Ishi, Y.; Kuriyama, Y.; Sakamoto, M.; Uesugi, T.; Mori, Y.

    2016-07-01

    In this paper we describe the methods and tools used to characterize a 150 MeV proton scaling fixed field alternating gradient (FFAG) accelerator at Kyoto University Research Reactor Institute. Many of the techniques used are unique to this class of machine and are thus of relevance to any future FFAG accelerator. For the first time we detail systematic studies undertaken to improve the beam quality of the FFAG. The control of beam quality in this manner is crucial to demonstrating high power operation of FFAG accelerators in future.

  3. Production of neutron-rich copper isotopes in 30-MeV proton-induced fission of sup 2 sup 3 sup 8 U

    Kruglov, K; Bruyneel, B; Dean, S S; Franchoo, S; Huyse, M; Kudryavtsev, Y; Müller, W F; Prasad, N V S; Raabe, R; Reusen, I; Schmidt, K H; Van De Vel, K; Van Duppen, P; Van Roosbroeck, J; Weissman, L

    2002-01-01

    The neutron-rich isotopes sup 7 sup 0 sup - sup 7 sup 6 Cu have been produced in 30-MeV proton-induced fission of sup 2 sup 3 sup 8 U using the Ion Guide Laser Ion Source (IGLIS) at LISOL. The production rates of the copper isotopes, and of the nickel and cobalt isotopes that were measured earlier, are compared to cross section calculations. Based on these new results an estimate for the cross section of sup 7 sup 8 Ni is given.

  4. Dose response curve for tumor induction with single and split doses of 10 MeV protons

    The response of rat skin to proton irradiation shows a rapid form of recovery of both sublethal and suboncogenic injury and RBE values between 2 and 3. The combination of RBE values greater than one, and recovery indicates that while protons induce injury more efficiently per unit absorbed dose than electrons, there is still a reversible component to the injury process

  5. Complete determination of neutron yield from 62 MeV protons on 9Be for the design of a low – power ADS

    Schillaci Maria

    2014-03-01

    Full Text Available Within the European Partitioning & Transmutation research programs, infrastructures specifically dedicated to the study of fundamental reactor physics of future fast neutron-based reactors are very important. In this respect, an Accelerator Driven System low-power prototype, based on a 70 MeV proton beam impinging on a thick Beryllium converter, was recently proposed and designed within the INFN-E project. The world data on neutron yield from Be target are scarce in this proton energy range. This lack of data calls for a dedicated measurement which was performed at INFN Laboratori Nazionali del Sud, covering a wide angular range, from 0 to 150 degrees, and an almost complete neutron energy interval, from thermal up to the beam energy. In this contribution the results are discussed together with the description of the proposed ADS facility.

  6. Investigation of activation cross-sections of proton induced nuclear reactions on natTl up to 42 MeV: review, new data and evaluation

    Tárkányi, F; Hermanne, A; Takács, S; Adam-Rebeles, R; Walravens, N; Cichelli, O; Ignatyuk, A V

    2013-01-01

    Cross-sections of proton induced nuclear reactions on natural thallium have been studied for investigation of the production of the medical important 201Tl diagnostic radioisotope. The excitation functions of 204mPb, 203Pb, 202mPb, 201Pb, 200Pb, 199Pb, 202Tl (direct, cumulative), 201Tl (direct, cumulative), 200Tl(direct), and 203Hg were measured up to 42 MeV proton energy by stacked foil technique and activation method. The experimental data were compared with the critically analyzed experimental data in the literature, with the IAEA recommended data and with the results of model calculations by using the ALICE-IPPE, EMPIRE-II and TALYS codes.

  7. A fully microscopic model analysis of the elastic and inelastic scattering of protons from 12C and for energies in the range 200 to 800 MeV

    Medium modified effective two nucleon interactions are defined for protons incident upon 12C with energies in the range 200 to 800 MeV. Those effective interactions have been folded with the ground state density to specify nonlocal optical potentials that were then used to analyse the elastic scattering differential cross sections and analysing powers. A select set of isoscalar and isovector, positive and negative parity, inelastic proton scattering transitions have also been analysed using the same (microscopic) optical models to define the distorted wave functions needed in Distorted Wave Approximation calculations of the associated differential cross sections and analysing powers. All results are compared with ones found using the Love-Franey effective interactions. The nuclear structure relating to these transitions was chosen from (0+2) ℎω and (1+3)ℎω shell model calculations of the positive and negative parity spectra of 12C respectively. 21 refs., 12 figs

  8. High-energy protons for radiotherapy - a review of activities at the 185-MeV synchrocyclotron in Uppsala

    The conceived merits of high-energy protons, in radio-therapy, depend on advantageous macroscopic absorption characteristics that permit unparallelled flexibility and precision. From a detailed review of pre-therapeutic biological experiments and clinical experience, it is concluded that proton therapy seems to be preferable to other types of therapy in some categories of tumours. Since high-energy protons deliver almost all dosage by low energy transfer, their use can be based directly on 75 years experience with conventional therapy. The strict evaluation of proton therapy through randomized clinical trials would require large-scale facilities. A clinical accelerator, designed for the combined routinary use of protons and fast neutrons, would be most appropriate. (orig.)

  9. Response of CR-39 to 0.9-2.5 MeV protons for KOH and NaOH etching solutions

    Bahrami, F.; Mianji, F.; Faghihi, R.; Taheri, M.; Ansarinejad, A.

    2016-03-01

    In some circumstances passive detecting methods are the only or preferable measuring approaches. For instance, defining particles' energy profile inside the objects being irradiated with heavy ions and measuring fluence of neutrons or heavy particles in space missions are the cases covered by these methods. In this paper the ability of polyallyl diglycol carbonate (PADC) track detector (commercially known as CR-39) for passive spectrometry of proton particles is studied. Furthermore, the effect of KOH and NaOH as commonly used chemical etching solutions on the response of the detector is investigated. The experiments were carried out with protons in the energy range of 0.94-2.5 MeV generated by a Van de Graaff accelerator. Then, the exposed track dosimeters were etched in the two aforementioned etchants through similar procedure with the same normality of 6.25 N and the same temperature of 85 °C. Formation of the tracks was precisely investigated and the track diameters were recorded following every etching step for each solution using a multistage etching process. The results showed that the proposed method can be efficiently used for the spectrometry of protons over a wider dynamic range and with a reasonable accuracy. Moreover, NaOH and KOH outperformed each other over different regions of the proton energy range. The detection efficiency of both etchants was approximately 100%.

  10. Theoretical study of the contribution to dose of secondary particles generated by protons of energy between 100 and 200 MeV in a cortical bone phantom

    In proton therapy, the deposition of secondary particles energy originated by nuclear inelastic process (n, 2H, 3H, 3He and α) has a contribution in the total dose that deserves to be discussed. In planning calculations implemented for routine treatment, the dose is calculated whereas the proton loses energy by ionization and or coulomb excitement. The contribution of inelastic processes associated with nuclear reactions is not considered. The dose distribution delivered in charged particle therapies, like in proton therapy, is due to both primary and secondary particles. The secondary particles are originating from non-elastic nuclear interactions, and are of interest for three reasons. First, if Monte Carlo treatment planning is envisaged, the question arises whether all nuclear interaction products deliver a significant contribution to the total dose and, hence, need to be tracked. Second, there could be an enhanced relative biological effectiveness (RBE) due to low energy and/or heavy secondary particles. Third, neutrons originating from nuclear interactions may deliver dose outside the target volume. There are only estimates for pure materials or simple composition (water, for example), because of the difficulty of processing targets consisting of different materials. For this project, we use the Monte Carlo method employing the code MCNPX v2.50 (Monte Carlo N-Particle eXtended) to present results of the contribution to the total dose of secondary particles. In this work, it was implemented a cylindrical phantom composed by cortical bone, for proton beams between 100 and 200 MeV. (author)

  11. Stopping powers and energy loss straggling for (0.9-3.4) MeV protons in a kapton polyimide thin film

    Damache, S.; Djaroum, S.; Ouichaoui, S.; Amari, L.; Moussa, D.

    2016-09-01

    The energy loss and energy loss straggling widths have been measured in transmission for Ep ≈ (0.9-3.4) MeV protons traversing a thin kapton polyimide foil. In a prior step, the thickness and non-uniformity of the target foil were carefully investigated. The overall relative uncertainties in the stopping power and energy loss straggling variance data amount, respectively, to less than 2% and 8%. The S(E) experimental data show to be in excellent agreement with available previous ones and with those compiled in the ICRU-49 report. They are fully consistent with the predictions of Sigmund-Schinner's binary collision theory of electronic stopping over the whole proton energy range explored. An average deviation of ∼2.5% relative to values calculated by the SRIM-2008 code, likely due to effects of valence electrons involving the Csbnd H, Cdbnd C and Cdbnd O bonds, is however observed at low proton velocities. The measured energy loss straggling data, which are unique to our knowledge, are found to be in good agreement with values derived by the classical Bohr formula for Ep ≳ 1300 keV but they significantly exceed Bohr's collisional energy loss straggling at lower proton velocities where target electrons can no longer be considered as free. They also show to be consistent with the predictions of the Bethe-Livingston and Sigmund-Schinner theories over the low proton velocity region (Ep 1300 keV, while deviations above the latter amounting up to ∼18% are observed at lower proton velocities.

  12. Some Relevant Aspects in the Design and Construction of a 30-62 MeV Linac Booster for Proton Therapy

    Vaccaro, V G

    2004-01-01

    Recent results in accelerator physics showed the feasibility of a coupling scheme between a cyclotron and a linac for proton acceleration. Cyclotrons with energies up to 30 MeV, mainly devoted to radioisotopes production, are available in a large number of medical centres. This suggested to design a linac booster able to increase the proton energy up to 62 MeV as required for treating tumours like the ocular ones. In this paper we will review the rationale of the project; we will discuss the basic design of a compact 3 GHz SCL (Side Coupled Linac) with a new approach to the linac cavities. Among the many challenges of such a project one of the most interesting is the tuning of the cavities. Because the tuning can be done only after assembling the system, it is difficult to detect which cavities are responsible for the detuning: indeed the resonant behavior of single cavity is lost since the resonances merge into the resonant modes of the whole system. It is shown how, from the measured mode frequencies of the...

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

    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 calculations 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 MeV 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. (atomic and molecular physics)

  14. Effect of irradiation with MeV protons and electrons on the conductivity compensation and photoluminescence of moderately doped p-4H-SiC (CVD)

    The compensation of moderately doped p-4H-SiC samples grown by the chemical vapor deposition (CVD) method under irradiation with 0.9-MeV electrons and 15-MeV protons is studied. The experimentally measured carrier removal rates are 1.2–1.6 cm–1 for electrons and 240–260 cm–1 for protons. The dependence of the concentration of uncompensated acceptors and donors, measured in the study, demonstrates a linear decrease with increasing irradiation dose to the point of complete compensation. This run of the dependence shows that compensation of the samples is due to the transition of carriers to deep centers formed by primary radiation-induced defects. It is demonstrated that, in contrast to n-SiC (CVD), primary defects in the carbon sublattice of moderately doped p-SiC (CVD) only cannot account for the compensation process. In p-SiC, either primary defects in the silicon sublattice, or defects in both sublattices are responsible for conductivity compensation. Also, photoluminescence spectra are examined in relation to the irradiation dose

  15. Effect of irradiation with MeV protons and electrons on the conductivity compensation and photoluminescence of moderately doped p-4H-SiC (CVD)

    Kozlovski, V. V. [St. Petersburg State Polytechnical University (Russian Federation); Lebedev, A. A., E-mail: shura.lebe@mail.ioffe.ru; Bogdanova, E. V.; Seredova, N. V. [Russian Academy of Sciences, Ioffe Physical–Technical Institute (Russian Federation)

    2015-09-15

    The compensation of moderately doped p-4H-SiC samples grown by the chemical vapor deposition (CVD) method under irradiation with 0.9-MeV electrons and 15-MeV protons is studied. The experimentally measured carrier removal rates are 1.2–1.6 cm{sup –1} for electrons and 240–260 cm{sup –1} for protons. The dependence of the concentration of uncompensated acceptors and donors, measured in the study, demonstrates a linear decrease with increasing irradiation dose to the point of complete compensation. This run of the dependence shows that compensation of the samples is due to the transition of carriers to deep centers formed by primary radiation-induced defects. It is demonstrated that, in contrast to n-SiC (CVD), primary defects in the carbon sublattice of moderately doped p-SiC (CVD) only cannot account for the compensation process. In p-SiC, either primary defects in the silicon sublattice, or defects in both sublattices are responsible for conductivity compensation. Also, photoluminescence spectra are examined in relation to the irradiation dose.

  16. Proton-gamma coincidence experiment on medium mass nuclei at 400MeV and study of reaction mechanisms

    Previous γ ray production experiments produced by proton on nuclei show important cross sections for residual nuclei corresponding to a four nucleon (2p + 2n) removal. With our (p - γ) coincidence experiment the forward emitted proton reflects the primary interaction and the γ spectra characterizes the final state of the reaction. Protons are detected with a magnetic spectrometer and γ rays are selected with a Ge(Li) diode. Angular and momentum analysis of scattered protons demonstrate a primary quasi free process on nucleons. No indication of knock out reactions on clusters has been seen. The residual nuclei are mainly produced by evaporation processes. A theoretical calculation involving intranuclear cascades and evaporation processes has been performed. The nucleus model is based upon a Fermi gas and nuclear density agrees with diffusion electron experiments. Residual nuclei far from target are well described with a such model. Residual nuclei near the target are sensitive to the nuclear structure

  17. Global magnetohydrodynamic simulation of the 15 March 2013 coronal mass ejection event—Interpretation of the 30-80 MeV proton flux

    Wu, Chin-Chun; Liou, Kan; Vourlidas, Angelos; Plunkett, Simon; Dryer, Murray; Wu, S. T.; Mewaldt, Richard A.

    2016-01-01

    The coronal mass ejection (CME) event on 15 March 2013 is one of the few solar events in Cycle 24 that produced a large solar energetic particle (SEP) event and severe geomagnetic activity. Observations of SEP from the ACE spacecraft show a complex time-intensity SEP profile that is not easily understood with current empirical SEP models. In this study, we employ a global three-dimensional (3-D) magnetohydrodynamic (MHD) simulation to help interpret the observations. The simulation is based on the H3DMHD code and incorporates extrapolations of photospheric magnetic field as the inner boundary condition at a solar radial distance (r) of 2.5 solar radii. A Gaussian-shaped velocity pulse is imposed at the inner boundary as a proxy for the complex physical conditions that initiated the CME. It is found that the time-intensity profile of the high-energy (>10 MeV) SEPs can be explained by the evolution of the CME-driven shock and its interaction with the heliospheric current sheet and the nonuniform solar wind. We also demonstrate in more detail that the simulated fast-mode shock Mach number at the magnetically connected shock location is well correlated (rcc ≥ 0.7) with the concurrent 30-80 MeV proton flux. A better correlation occurs when the 30-80 MeV proton flux is scaled by r-1.4(rcc = 0.87). When scaled by r-2.8, the correlation for 10-30 MeV proton flux improves significantly from rcc = 0.12 to rcc = 0.73, with 1 h delay. The present study suggests that (1) sector boundary can act as an obstacle to the propagation of SEPs; (2) the background solar wind is an important factor in the variation of IP shock strength and thus plays an important role in manipulation of SEP flux; (3) at least 50% of the variance in SEP flux can be explained by the fast-mode shock Mach number. This study demonstrates that global MHD simulation, despite the limitation implied by its physics-based ideal fluid continuum assumption, can be a viable tool for SEP data analysis.

  18. Double beta decay of Uranium-238: Proton reactions of 238U in 5--12 MeV range. Final report, April 15, 1987--March 31, 1992

    This report is in two parts. The first part reports on the experimental work determining the half-life for double beta decay of 238U to 238PU to be (2.0 ± 0.6) x 1021 years. This is the first evidence for a third mode of decay of this heaviest naturally occurring nucleus. This rate is about 106 times slower than spontaneous fission, which itself is about 106 times slower than alpha decay. The implication of this double beta decay to neutrino masses depends on uncertain theoretical calculations of the rate for such a heavy nucleus. The second part reports on yields of principal fission products from 5.6, 7.3, 9.4, and 11.5 MeV proton interactions with 238U. The yields at 11.5 MeV are similar to those from 14 MeV neutron fission of 238U. At the same time, the production cross sections of 238Np at the same energies are determined. This nuclide is produced as often as fission at the lowest energy but only 3.8% as often at the highest energy

  19. Intercomparisons of benchmark calculations for the transmission of quasi-monoenergetic neutrons generated by 43- and 68-MeV protons through iron and concrete shields

    To evaluate calculation codes and the nuclear data in the energy region from 20 MeV to 100 MeV, intercomparisons of benchmark calculations with the MORSE-CG, modified HETC-KFA2 and MCNP4A codes were carried out for the transmission of quasi-monoenergetic neutrons generated by 43- and 68-MeV protons through iron and concrete shields. The comparisons between the calculations and the experiments show that the spectra on the axis of the neutron beam calculated by the MORSE-CG and the MCNP4A codes with the DLC-119/HILO86 and HILO86R are in good agreement with those measured. The spectra calculated for the thin shields by the modified HETC-KFA2 code agree well with those measured, while those for the thick shields are higher than measured ones. The spectra at the off-axis positions calculated by the MORSE-CG code agree well with those measured, though the modified HETC-KFA2 code greatly underestimates the measured spectra. (author)

  20. Calculations of neutron and proton induced reaction cross sections for actinides in the energy region from 10MeV to 1GeV

    Several nuclear model codes were applied to calculations of nuclear data in the energy region from 10MeV to 1GeV. At energies up to 100MeV the nuclear theory code GNASH was used for nuclear data calculation for neutrons incident for on 238U, 233-236U, 238-242Pu, 237Np, 232Th, 241-243Am and 242-247Cm. At energies from 100MeV to 1GeV the intranuclear cascade exciton model including the fission process was applied to calculations of protons and neutrons with 233U, 235U, 238U, 232Th, 232Pa, 237Np, 238Np, 239Pu, 241Am, 242Am and 242-248Cm. Determination of parameter systematics was a major effort in the present work that was aimed at improving the predictive capability of the models used. An emphasis was placed upon a simultaneous analysis of data for a variety of reaction channels for the nuclei considered, as well as of data that are available for nearby nuclei or for other incident particles. Comparisons with experimental data available on multiple reaction cross sections, isotope yields, fission cross sections, particle multiplicities, secondary particle spectra, and double differential cross sections indicate that the calculations reproduce the trends, and often the details, of the measurements data. (author) 82 refs

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

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

    2007-05-15

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

  2. Observations of protons with energies Esub(p) >=100 MeV and electrons with energies Esub(e) >=20 MeV by means of the oriented Kosmos-208 and Kosmos-228 satellites

    Measurement results of cosmic radiation have been analyzed using scintillation-Cherenkov spectrometer SEhZ-1 in oriented ''Kosmos-208'' and ''Kosmos-228'' satellites. Applicability of the Mc Ilwain's parameter L for the description of planetary distribution of detected radiation is shawn. The effect of equatorial plato and reverse latitude pitch ip the equatorial area is discussed. An essential difference in the instrument readings during its axis orientation relative to nadir or zenith is domonstrated. When orienting the instrument axis relative to zenith the data on latitude pitch of radiatione detected by means of a channel with the 500 MeV threshold (protons), in the range of medium and high latitudes coincide with the results of battoo; experiments on xntensity and sctrum measurement of primary cosmic rays to the accuracy of 35%. A possibility of observation with the SEhZ-1 spectrometer of the dynamics of high-energy protons (and electrons) of the internal radiation belt of the Earth in the region of Brasil magnetic anomaly is shown

  3. Relative Biological Effectiveness Variation Along Monoenergetic and Modulated Bragg Peaks of a 62-MeV Therapeutic Proton Beam: A Preclinical Assessment

    Chaudhary, Pankaj; Marshall, Thomas I. [Centre for Cancer Research and Cell Biology, School of Medicine, Dentistry and Biomedical Sciences, Queen' s University Belfast, Belfast (United Kingdom); Perozziello, Francesca M.; Manti, Lorenzo [Department of Physics, University of Naples Federico II and INFN Naples Section University of Naples, Naples (Italy); Currell, Frederick J.; Hanton, Fiona [Centre for Plasma Physics, School of Mathematics and Physics, Queen' s University Belfast, Belfast (United Kingdom); McMahon, Stephen J.; Kavanagh, Joy N. [Centre for Cancer Research and Cell Biology, School of Medicine, Dentistry and Biomedical Sciences, Queen' s University Belfast, Belfast (United Kingdom); Cirrone, Giuseppe Antonio Pablo; Romano, Francesco [Istituto Nazionale di Fisica Nucleare, LNS, Catania (Italy); Prise, Kevin M., E-mail: k.prise@qub.ac.uk [Centre for Cancer Research and Cell Biology, School of Medicine, Dentistry and Biomedical Sciences, Queen' s University Belfast, Belfast (United Kingdom); Schettino, Giuseppe [Centre for Cancer Research and Cell Biology, School of Medicine, Dentistry and Biomedical Sciences, Queen' s University Belfast, Belfast (United Kingdom); National Physical Laboratory, Teddington (United Kingdom)

    2014-09-01

    Purpose: The biological optimization of proton therapy can be achieved only through a detailed evaluation of relative biological effectiveness (RBE) variations along the full range of the Bragg curve. The clinically used RBE value of 1.1 represents a broad average, which disregards the steep rise of linear energy transfer (LET) at the distal end of the spread-out Bragg peak (SOBP). With particular attention to the key endpoint of cell survival, our work presents a comparative investigation of cell killing RBE variations along monoenergetic (pristine) and modulated (SOBP) beams using human normal and radioresistant cells with the aim to investigate the RBE dependence on LET and intrinsic radiosensitvity. Methods and Materials: Human fibroblasts (AG01522) and glioma (U87) cells were irradiated at 6 depth positions along pristine and modulated 62-MeV proton beams at the INFN-LNS (Catania, Italy). Cell killing RBE variations were measured using standard clonogenic assays and were further validated using Monte Carlo simulations and the local effect model (LEM). Results: We observed significant cell killing RBE variations along the proton beam path, particularly in the distal region showing strong dose dependence. Experimental RBE values were in excellent agreement with the LEM predicted values, indicating dose-averaged LET as a suitable predictor of proton biological effectiveness. Data were also used to validate a parameterized RBE model. Conclusions: The predicted biological dose delivered to a tumor region, based on the variable RBE inferred from the data, varies significantly with respect to the clinically used constant RBE of 1.1. The significant RBE increase at the distal end suggests also a potential to enhance optimization of treatment modalities such as LET painting of hypoxic tumors. The study highlights the limitation of adoption of a constant RBE for proton therapy and suggests approaches for fast implementation of RBE models in treatment planning.

  4. Relative Biological Effectiveness Variation Along Monoenergetic and Modulated Bragg Peaks of a 62-MeV Therapeutic Proton Beam: A Preclinical Assessment

    Purpose: The biological optimization of proton therapy can be achieved only through a detailed evaluation of relative biological effectiveness (RBE) variations along the full range of the Bragg curve. The clinically used RBE value of 1.1 represents a broad average, which disregards the steep rise of linear energy transfer (LET) at the distal end of the spread-out Bragg peak (SOBP). With particular attention to the key endpoint of cell survival, our work presents a comparative investigation of cell killing RBE variations along monoenergetic (pristine) and modulated (SOBP) beams using human normal and radioresistant cells with the aim to investigate the RBE dependence on LET and intrinsic radiosensitvity. Methods and Materials: Human fibroblasts (AG01522) and glioma (U87) cells were irradiated at 6 depth positions along pristine and modulated 62-MeV proton beams at the INFN-LNS (Catania, Italy). Cell killing RBE variations were measured using standard clonogenic assays and were further validated using Monte Carlo simulations and the local effect model (LEM). Results: We observed significant cell killing RBE variations along the proton beam path, particularly in the distal region showing strong dose dependence. Experimental RBE values were in excellent agreement with the LEM predicted values, indicating dose-averaged LET as a suitable predictor of proton biological effectiveness. Data were also used to validate a parameterized RBE model. Conclusions: The predicted biological dose delivered to a tumor region, based on the variable RBE inferred from the data, varies significantly with respect to the clinically used constant RBE of 1.1. The significant RBE increase at the distal end suggests also a potential to enhance optimization of treatment modalities such as LET painting of hypoxic tumors. The study highlights the limitation of adoption of a constant RBE for proton therapy and suggests approaches for fast implementation of RBE models in treatment planning

  5. Analyzing powers and proton spin transfer coefficients in the elastic scattering of 800 MeV polarized protons from an L-type polarized deuteron target at small momentum transfers

    Analyzing powers and spin transfer coefficients which describe the elastic scattering of polarized protons from a polarized deuteron target have been measured. The energy of the proton beam was 800 MeV and data were taken at laboratory scattering angles of 7, 11, 14, and 16.5 degrees. One analyzing power was also measured at 180 degrees. Three linearly independent orientations of the beam polarization were used and the target was polarized parallel and antiparallel to the direction of the beam momentum. The data were taken with the high resolution spectrometer at the Los Alamos Meson Physics Facility (experiment 685). The results are compared with multiple scattering predictions based on Dirac representations of the nucleon-nucleon scattering matrices. 27 refs., 28 figs., 4 tabs

  6. Pre-equilibrium excitation of nuclei in (p,α) and (p,3He) reactions induced by 120, 160 and 200 MeV protons

    The study of pre-equilibrium reactions induced by medium-energy light ions have become of increasing importance in recent years as they represent the bulk of the measured spectrum. On a nuclear time scale these reactions are known to take place after a one-step process of exciting discrete states in the residual nucleus but long before the process whereby the projectile distributes its kinetic energy equally over all target nucleons to form a compound nucleus which decays statistically. In this work the systematic behaviour of the continuum of complex ejectiles was investigated as a function of incident proton energy and target mass. The continuum energy spectra for the reactions 27Al(p,X), 59Co(p,X) and 197Au(p,X), with X = α and 3He were measured using a five element detector telescope. Data was acquired at scattering angles between 10-160 degrees at incident proton energies of 120 and 200 MeV, and at scattering angles between 20-140 degrees for an incident proton energy of 160 MeV. Experimental angle-integrated cross sections were compared with calculated angle-integrated cross sections using the geometry dependent hybrid (GDH) model. The comparison between the experimental data and the calculations were used to quantitatively estimate the contribution of the evaporation process to the pre-equilibrium spectrum. The experimental angular distributions from the reaction (p,α) and (p,3He) on 27Al, 59Co and 197Au were compared with calculated angular distributions using the phenomenological parametrization of Kalbach. In general good agreement between the experimental data and the calculations were obtained. Minor discrepancies were observed with regard to target mass and incident proton energy dependence. It is believed that the characteristics of these discrepancies could provide guidance to the future attempts to develop a proper quantum mechanical description of the reaction mechanism of complex-ejectile production induced by energetic protons. (author). 39

  7. The comparison of GEANT 4.8.2 and 4.9.2 results for the 25MeV protons in thick polyethylene

    Yevseyeva, Olga; Assis, Joaquim T. de; Ievsieieva, Ievgeniia [Universidade Estadual do Rio de Janeiro (UERJ), Nova Friburgo, RJ (Brazil). Instituto Politecnico; Evseev, Ivan G.; Schelin, Hugo R.; Ahmann, Francielle; Paschuk, Sergei A.; Milhoretto, Edney [Universidade Tecnologica Federal do Parana (UTFPR), Curitiba, PR (Brazil); Diaz, Katherin S. [Centro de Aplicaciones Tecnologicas y Desarrollo Nuclear, Havana (Cuba); Hormaza, Joel M. [Universidade Estadual Paulista (UNESP), Botucatu, SP (Brazil). Instituto de Biociencias; Lopes, Ricardo T. [Coordenacao dos Programas de Pos-Graduacao de Engenharia (COPPE/UFRJ), RJ (Brazil). Lab. de Instrumentacao Nuclear

    2011-07-01

    Full text: The fidelity of Monte Carlo simulations is crucial, especially if for medical applications. Our earlier study has shown that the GEANT4 simulations of proton energy spectra after thick absorbers do not agree well with existing experimental data. Moreover, the spectra simulated for the Bethe-Bloch domain were showing an unexpected sensitivity to the choice of low-energy electromagnetic models during the code execution. These observations were done with the GEANT4 up to version 8.2 during our previous simulations for proton Computerized Tomography (pCT). As one of the probable reasons for these effects could be some specific feature in the code, or some specific implicit parameters in the GEANT4 manual, we have decided to continue our observations, but this time - with version 4.9.2 of the GEANT. This work describes in details the new simulations for 25 MeV protons passing through 6mm polyethylene absorber. As in our previous simulations, we have started from the Hadron therapy Example of GEANT4 official release by adjusting the geometry only. We have tested all available choices of the Electromagnetic Physics Models. The results are compared with our previous GEANT4, TRIM/SRIM and MCNPX simulations, with theoretical predictions and with experimental data. Some variations in comparison with our previous results were obtained. (author)

  8. Optical spectroscopy and imaging of colour centres in lithium fluoride crystals and thin films irradiated by 3 MeV proton beams

    Piccinini, M., E-mail: massimo.piccinini@enea.it; Ambrosini, F.; Ampollini, A.; Carpanese, M.; Picardi, L.; Ronsivalle, C.; Bonfigli, F.; Libera, S.; Vincenti, M.A.; Montereali, R.M.

    2014-05-01

    Lithium fluoride is a well-known dosimeter material and it is currently under investigation also for high-resolution radiation imaging detectors based on colour centre photoluminescence. In order to extend their applications, proton beams of 3 MeV energy, produced by a linear accelerator, were used to irradiate LiF crystals and thin films in the fluence range of 10{sup 10}–10{sup 15} protons/cm{sup 2}. The irradiation induces the formation of colour centres, mainly the primary F centre and the aggregate F{sub 2} and F{sub 3}{sup +} defects, which are stable at room temperature. By optical pumping in the blue spectral region, the F{sub 2} and F{sub 3}{sup +} centres emit broad photoluminescence bands in the visible spectral range. By conventional fluorescence microscopy, the integrated photoluminescence intensity was carefully measured in LiF crystals and thin films as a function of the irradiation fluence: a linear optical response was obtained in a large range of fluence, which is dependent on the used LiF samples. Colour centres concentrations were estimated in LiF crystals by optical absorption spectroscopy. It was possible to record the transversal proton beam intensity profile by acquiring the photoluminescence image of the irradiated spots on LiF films.

  9. Impact of the divacancy (?) on the generation-recombination properties of 10 MeV proton irradiated Float-Zone silicon diodes

    Simoen, E; Gaubas, E; Ohyama, H

    2000-01-01

    In this paper, the correlation between the microscopic damage parameters and the macroscopic device performance degradation is investigated for 10 MeV proton-irradiated Float-Zone (FZ) silicon diodes, with n- and p-type doping density in the 10 sup 1 sup 4 cm sup - sup 3 range. It is shown that the radiation-induced deep-level concentrations, obtained from deep-level transient spectroscopy show a proportional increase with the proton fluence, for the dominant traps and this both in n- and p-type substrates. The same applies for the increase in the reverse diode current and the reduction of the inverse carrier recombination lifetime. The obtained spectroscopic information is substituted in the Shockley-Read-Hall model for the diode reverse current and recombination lifetime. From the comparison between calculated and measured parameters, it is concluded that in proton-irradiated diodes fabricated in FZ p- and n-type substrates, the divacancy related deep-level centres at E sub c -0.42 eV play a dominant role i...

  10. An empirical formula for L line X-ray production cross-section of elements from Ag to U for protons below 3.5 MeV

    When computing element concentration from proton induced X-ray emission analysis, an important parameter is the X-ray production cross-section. There have been numerous experimental and theoretical works in this field. Nonetheless, although there is a simple analytical formula to compute K X-ray cross-sections, there is no such ones for the L lines. We present here analytical formulas for the cross-section of the three main X-ray lines Lα, Lβ and Lγ based on experimental data. So far, nearly 3000 values of cross-sections for elements from Ag to U and proton energy ranging from 0.5 to 3.5 MeV have been collected from various references. This experimental data set has been fitted for each X-ray line with an exponential function depending on the proton energy and on the element atomic number. These fitted values have then been compared to the experimental data and with theoretical values obtained by the ECPSSR theory and Coster-Kronig fluorescence yields

  11. Elastic and inelastic scattering of polarized protons from carbon-12 at 400, 600, and 700 MeV

    Good resolution cross section and analyzing power (p vector, p') data for many states in 12C up to an excitation energy of 21 MeV and spanning a momentum transfer range of 0.3 to 2.1 fm-1 were obtained using the High Resolution Spectrometer at the Clinton P. Anderson Meson Physics Facility at incident beam energies of 398, 597, and 698 MeV. Optical model potentials were obtained from the elastic scattering data. Inelastic data were analyzed in the Distorted Wave Impulse Approximation using the Love-Franey effective nucleon-nucleon interaction. The energy dependent isoscalar natural parity cross sections were underestimated, while phase difficulties were encountered in fitting analyzing powers. The energy independent isovector natural parity cross sections were reasonably reproduced, but analyzing powers were not, the calculations yielding positive trends whereas the data are of opposite sign. The energy independent isoscalar and isovector unnatural parity cross sections were quite well reproduced up to moderate momentum transfers, and striking successes were observed for some analyzing power data. Systematics of energy dependence together with the results of the DWIA calculations permitted the assignment of spin, parity and isospin quantum numbers to states in the 18-21 MeV excitation region. 64 references

  12. Measurement of Δsigma/sub L/ and C/sub L/L = (L,L;0,0) in proton-proton scattering between 300 and 800 MeV

    Measurements are reported of the difference Δsigma/sub L/ between proton-proton total cross sections for parallel and antiparallel spin states and of the parameter C/sub L/L for proton-proton elastic scattering near 900, for thirteen energies between 300 and 800 MeV. The Δsigma/sub L/ results agree well with previous ANL ZGS and SIN data, but disagree with recent results from TRIUMF. Attempts to understand the cause of the discrepancy have been unsuccessful, but possible sources are discussed. The Δsigma/sub L/ and C/sub L/L results have been used with other experimental data to extract quantities which depend only on spin-singlet, coupled spin-triplet, and spin-triplet partial waves. Structure is found in these quantities, which appears to be associated with the resonantlike 1D2 and 3F3 partial waves. Additional similar structure is also found, which may be due either to the 3P0 partial wave or the (3P2, 3F2) partial-wave pair

  13. SU-E-T-554: Monte Carlo Calculation of Source Terms and Attenuation Lengths for Neutrons Produced by 50–200 MeV Protons On Brass

    Ramos-Mendez, J; Faddegon, B [University of California San Francisco, San Francisco, CA (United States); Paganetti, H [Massachusetts General Hospital, Boston, MA (United States)

    2015-06-15

    Purpose: We used TOPAS (TOPAS wraps and extends Geant4 for medical physicists) to compare Geant4 physics models with published data for neutron shielding calculations. Subsequently, we calculated the source terms and attenuation lengths (shielding data) of the total ambient dose equivalent (TADE) in concrete for neutrons produced by protons in brass. Methods: Stage1: The Bertini and Binary nuclear models available in Geant4 were compared with published attenuation at depth of the TADE in concrete and iron. Stage2: Shielding data of the TADE in concrete was calculated for 50– 200 MeV proton beams on brass. Stage3: Shielding data from Stage2 was extrapolated for 235 MeV proton beams. This data was used in a point-line-source analytical model to calculate the ambient dose per unit therapeutic dose at two locations inside one treatment room at the Francis H Burr Proton Therapy Center. Finally, we compared these results with experimental data and full TOPAS simulations. Results: At larger angles (∼130o) the TADE in concrete calculated with the Bertini model was about 9 times larger than that calculated with the Binary model. The attenuation length in concrete calculated with the Binary model agreed with published data within 7%±0.4% (statistical uncertainty) for the deepest regions and 5%±0.1% for shallower regions. For iron the agreement was within 3%±0.1%. The ambient dose per therapeutic dose calculated with the Binary model, relative to the experimental data, was a ratio of 0.93±0.16 and 1.23±0.24 for two locations. The analytical model overestimated the dose by four orders of magnitude. These differences are attributed to the complexity of the geometry. Conclusion: The Binary and Bertini models gave comparable results, with the Binary model giving the best agreement with published data at large angle. Shielding data we calculated using the Binary model is useful for fast shielding calculations with other analytical models. This work was supported by

  14. Response of metallic glasses Fe40Ni40P14B6 and Fe80B20 to irradiation with 800-MeV protons

    Metallic glasses with compositions of Fe40Ni40P14B6 and Fe80B20 were irradiated in the 800 MeV proton beam at the Los Alamos Meson Physics Facility while the electrical resistance and length changes were monitored. The resistance and the length of the first alloy were both found to increase and saturate with dose to ΔR/R approx. = 5 x 10-3 and ΔL/L approx. = 2 x 10-3. For the second alloy the total dose of 1.1 x 1019 p/cm2, which was calculated to give roughly 0.12 dpa, was slightly less than that required for saturation. No annealing of these increases was observed for anneals from room temperature to 2500C. These results are interpreted in terms of a model in which collision cascades create small regions of increased atomic disorder which fully overlap each other at saturation

  15. Thick lead target exposed to 660 MeV protons: benchmark model on radioactive nuclides production and heat generation, and beyond

    The benchmark is proposed on the basis of the first axial residue production distributions measurements in the thick Pb target irradiated with 660 MeV protons. Heating calculation during irradiation and decay heat assessment is foreseen as well. First benchmarking results with MCNPX2.5.0 and FLUKA2006.3 of residue production are presented. These new data from thick targets allow a consistent check of physics models with the predictions coming from microscopic residue cross sections (in thin lead target) over a wide energy range and the use of particle spectra simulations. Results obtained for thin targets data are consistent with this experiment and a combination of both sets of data could more constrain the INC models especially on the excitation energy of the nucleus before deexcitation. The main difficulties, data accuracy and contribution of emitted particles to residue production, are analysed and discussed in this work. (authors)

  16. Proton induced L and L-subshell X-ray cross-sections in Sm and Yb at 1-2.5 MeV

    Ouziane, S. [Faculte de Physique, Universite des Sciences et de Technologie Houari Boumediene, BP 32, El Alia, Bab Ezzouar, 16111 Alger (Algeria)]. E-mail: sounucl@yahoo.fr; Amokrane, A. [Faculte de Physique, Universite des Sciences et de Technologie Houari Boumediene, BP 32, El Alia, Bab Ezzouar, 16111 Alger (Algeria); Ecole Nationale Preparatoire aux Etudes d' Ingeniorat, Rouiba, Alger (Algeria); Toumert, I. [Centre de Recherches Nucleaires d' Alger, 2 Bd Frantz Fanon, BP 399, Alger (Algeria); Nourreddine, A. [Institut Pluridisciplinaire Hubert Curien (IPHC), 67037 Strasbourg cedex 2 (France); Pape, A. [Institut Pluridisciplinaire Hubert Curien (IPHC), 67037 Strasbourg cedex 2 (France)

    2006-08-15

    L and L-subshell X-ray production cross-sections for protons on Sm and Yb have been measured in the incident energy range of 1-2.5 MeV. The values obtained agree with data available in Sokhi and Crumpton [R.S. Sokhi, D. Crumpton, At. Data Nucl. Data Tables 30 (1984) 49] and Orlic et al. [I. Orlic, C.H. Sow, S.M. Tang, At. Data Nucl. Data Tables 56 (1994) 159] and the uncertainties are less than 12%. The data are compared with predictions of the modified plane wave Born approximation by introducing corrections for energy loss (E), Coulomb deflection (C), perturbed stationary state (PSS) and relativistic (R) effects which is the so-called ECPSSR model.

  17. Proton induced L and L-subshell X-ray cross-sections in Sm and Yb at 1-2.5 MeV

    L and L-subshell X-ray production cross-sections for protons on Sm and Yb have been measured in the incident energy range of 1-2.5 MeV. The values obtained agree with data available in Sokhi and Crumpton [R.S. Sokhi, D. Crumpton, At. Data Nucl. Data Tables 30 (1984) 49] and Orlic et al. [I. Orlic, C.H. Sow, S.M. Tang, At. Data Nucl. Data Tables 56 (1994) 159] and the uncertainties are less than 12%. The data are compared with predictions of the modified plane wave Born approximation by introducing corrections for energy loss (E), Coulomb deflection (C), perturbed stationary state (PSS) and relativistic (R) effects which is the so-called ECPSSR model

  18. Production cross sections of products in the proton induced reactions on natNd in the energy region up to 45 MeV

    Yang, Sung-Chul; Kim, Kwangsoo; Song, Tae-Yung; Lee, Young-Ouk; Kim, Guinyun

    2015-11-01

    The production cross sections of 141,143,144,146,148m,148g,149,150Pm, 139m,147,149Nd, 138m,142gPr, and 139gCe in the natNd(p,x) reactions were determined by a stacked-foil activation technique for the proton energy range up to 45 MeV using the MC-50 cyclotron of Korea Institute of Radiological and Medical Sciences. The measured cross sections were compared with literature data as well as data from the TENDL-2014 library based on TALYS 1.6. The production cross sections of the above radionuclides are slightly higher than the literature data but are in general agreement with values in TENDL-2014 library except for 148mPm, 148gPm, 139mNd, and 142gPr. The thick target integral yields of the produced radionuclides were also deducted from the measured cross sections.

  19. Activation cross-sections of longer lived products of proton induced nuclear reactions on manganese up to 70 MeV

    Ditrói, F; Takács, S; Hermanne, A; Yamazaki, H; Baba, M; Mohammadi, A

    2013-01-01

    In the frame of a systematic study of the activation cross-sections of the proton induced nuclear reactions, excitation functions of the 55Mn(p,x)154,152gMn,51Cr and 48V were measured up to 70 MeV. Cross-sections were measured with the activation method using a stacked foil irradiation technique and high resolution gamma-ray spectrometry. The experimental data are analyzed and compared to the earlier results and to the prediction of the EMPIRE-3 as well as the TALYS theoretical model code in the TENDL-2012 library. From the measured cross-section data integral production yields were calculated. Practical applications of the cross-sections are discussed.

  20. Measurement of fast neutron spectra from the interaction of 20 MeV protons with thick Be and C targets using CR-39 detector

    Highlights: • Neutron yield from interaction of 20 MeV protons with thick Be and C targets are measured using CR-39. • A new image analysing program for neutron spectrometry and dosimetry is developed and applied in this study. • Dose related parameters for the neutrons from these reactions are also estimated. -- Abstract: Fast neutron spectral yield from the interaction of 20 MeV protons with thick Be and C targets are measured using CR-39 detectors. An image analysing program (autoTRAKn) dedicated for neutron spectrum generation and dose estimation is developed based on the analysis of greylevel variations within each track and is used in the present study. The most important parameters for neutron spectrometry, i.e., track depth (length) and angle of all neutron-induced recoil tracks are determined using autoTRAKn. The methodology is tested successfully to reproduce the spectra of some standard neutron sources which was reported earlier. In this study, autoTRAKn is applied to generate neutron spectra from the above mentioned reactions, i.e., 9Be(p, n), 12C(p, n) and the neutron yields (total number of neutrons per projectile) for both the reactions are determined by folding the track density with the detector response. The dose equivalents and H∗(10)-to-fluence ratios are also estimated. All these quantities are automatically obtained from the program. The neutron yield and the dose equivalent for 9Be(p, n) reaction are found to be about 4 times higher than that for 12C(p, n) reaction. The present methodology for neutron spectrum generation is found to be simple and effective and does not involve the complex spectrum unfolding procedures

  1. MeV single-ion beam irradiation of mammalian cells using the Surrey vertical nanobeam, compared with broad proton beam and X-ray irradiations

    Highlights: •Recently completed nanobeam at the Surrey Ion Beam Centre was used. •3.8-MeV single and broad proton beams irradiated Chinese hamster cells. •Cell survival curves were measured and compared with 300-kV X-ray irradiation. •Single ion irradiation had a lower survival part at ultra-low dose. •It implies hypersensitivity, bystander effect and cell cycle phase of cell death. -- Abstract: As a part of a systematic study on mechanisms involved in physical cancer therapies, this work investigated response of mammalian cells to ultra-low-dose ion beam irradiation. The ion beam irradiation was performed using the recently completed nanobeam facility at the Surrey Ion Beam Centre. A scanning focused vertical ion nano-beam was applied to irradiate Chinese hamster V79 cells. The V79 cells were irradiated in two different beam modes, namely, focused single ion beam and defocused scanning broad ion beam of 3.8-MeV protons. The single ion beam was capable of irradiating a single cell with a precisely controlled number of the ions to extremely low doses. After irradiation and cell incubation, the number of surviving colonies as a function of the number of the irradiating ions was measured for the cell survival fraction curve. A lower survival for the single ion beam irradiation than that of the broad beam case implied the hypersensitivity and bystander effect. The ion-beam-induced cell survival curves were compared with that from 300-kV X-ray irradiation. Theoretical studies indicated that the cell death in single ion irradiation mainly occurred in the cell cycle phases of cell division and intervals between the cell division and the DNA replication. The success in the experiment demonstrated the Surrey vertical nanobeam successfully completed

  2. MeV single-ion beam irradiation of mammalian cells using the Surrey vertical nanobeam, compared with broad proton beam and X-ray irradiations

    Prakrajang, K. [Plasma and Beam Physics Research Facility, Department of Physics and Materials Science, Faculty of Science, Chiang Mai University, Chiang Mai 50200 (Thailand); Faculty of Science, Maejo University, Chiang Mai 50290 (Thailand); Jeynes, J.C.G.; Merchant, M.J.; Kirkby, K.; Kirkby, N. [Surrey Ion Beam Center, Faculty of Engineering and Physical Science, University of Surrey, Guildford Surrey, GU2 7XH (United Kingdom); Thopan, P. [Plasma and Beam Physics Research Facility, Department of Physics and Materials Science, Faculty of Science, Chiang Mai University, Chiang Mai 50200 (Thailand); Yu, L.D., E-mail: yuld@fnrf.science.cmu.ac.th [Plasma and Beam Physics Research Facility, Department of Physics and Materials Science, Faculty of Science, Chiang Mai University, Chiang Mai 50200 (Thailand); Thailand Center of Excellence in Physics, Commission on Higher Education, 328 Si Ayutthaya Road, Bangkok 10400 (Thailand)

    2013-07-15

    Highlights: •Recently completed nanobeam at the Surrey Ion Beam Centre was used. •3.8-MeV single and broad proton beams irradiated Chinese hamster cells. •Cell survival curves were measured and compared with 300-kV X-ray irradiation. •Single ion irradiation had a lower survival part at ultra-low dose. •It implies hypersensitivity, bystander effect and cell cycle phase of cell death. -- Abstract: As a part of a systematic study on mechanisms involved in physical cancer therapies, this work investigated response of mammalian cells to ultra-low-dose ion beam irradiation. The ion beam irradiation was performed using the recently completed nanobeam facility at the Surrey Ion Beam Centre. A scanning focused vertical ion nano-beam was applied to irradiate Chinese hamster V79 cells. The V79 cells were irradiated in two different beam modes, namely, focused single ion beam and defocused scanning broad ion beam of 3.8-MeV protons. The single ion beam was capable of irradiating a single cell with a precisely controlled number of the ions to extremely low doses. After irradiation and cell incubation, the number of surviving colonies as a function of the number of the irradiating ions was measured for the cell survival fraction curve. A lower survival for the single ion beam irradiation than that of the broad beam case implied the hypersensitivity and bystander effect. The ion-beam-induced cell survival curves were compared with that from 300-kV X-ray irradiation. Theoretical studies indicated that the cell death in single ion irradiation mainly occurred in the cell cycle phases of cell division and intervals between the cell division and the DNA replication. The success in the experiment demonstrated the Surrey vertical nanobeam successfully completed.

  3. Excitation functions of proton induced reactions on natOs up to 65 MeV: Experiments and comparison with results from theoretical codes

    Activation of thin natOs targets, electrodeposited on Ni backings, was investigated for the first time in stacked foil irradiations with 65 MeV and 34 MeV proton beams. Assessments of the produced radionuclides by high resolution gamma-ray spectroscopy yielded excitation functions for formation of 184, 185, 186m,m+g, 187m+g, 188m+g, 189m2+m1+g, 190m2,m1+g, 192m1+gIr and 185cum, 191m+gOs, 183m+gRe. Where available comparisons with the reaction cross sections obtained in 2 earlier studies on enriched 192Os were made. Reduced uncertainty on cross sections is obtained by simultaneous remeasurement of the 27Al(p,x)22,24Na, natNi(p,x)57Ni and natTi(p,x)48V monitor reactions over wide relevant energy ranges. Confirmation of monitoring took place by assessment of excitation functions of 61Cu, 56Ni, 55,56,57,58Co and 52Mn induced in the Ni backings and comparison with a recent compilation for most of these radionuclides. Contributing reactions and overall cross sections are discussed and were evaluated in comparison with the results of the theoretical code TALYS 1.6 (values from the on-line library TENDL-2013)

  4. Systematics of the excitation of M1 resonances in medium heavy nuclei by 200 MeV proton inelastic scattering

    In a series of seventeen nuclei ranging from 51V to 140Ca, broad resonance structures are observed at energies between 8 and 10 MeV, nearly mass independent. These resonances have very forward peaked angular distributions which imply that they are populated by an angular momentum transfer of zero. This together with the observed excitation energies suggests an M1 character for these resonances. In 51V, 58Ni, 60Ni, 62Ni, a sharp peak located at an excitation energy above the threshold for neutron emission is interpreted as a part of the T0+1 component of the M1 resonances. Cross-sections are given for all the M1 resonances. For 58Ni, 90Zr, 92Mo, 120Sn and 140Ca, an ''attenuation'' factor for the cross-sections is extracted in a OWIA calculation assuming simple shell model structures for these resonances

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

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

    2011-10-21

    The experimental characterization of the neutron fields produced as parasitic effect in medical accelerators is assuming an increased importance for either the patient protection or the facility design aspects. Medical accelerators are diverse in terms of particle type (electrons or hadrons) and energy, but the radiation fields around them have in common (provided that a given threshold energy is reached) the presence of neutrons with energy span over several orders of magnitude. Due to the large variability of neutron energy, field or dosimetry measurements in these workplaces are very complex, and in general, cannot be performed with ready-to-use commercial instruments. In spite of its poor energy resolution, the Bonner Sphere Spectrometer (BSS) is the only instrument able to simultaneously determine all spectral components in such workplaces. The energy range of this instrument is limited to E<20 MeV if only polyethylene spheres are used, but can be extended to hundreds of MeV by including metal-loaded spheres (extended range BSS, indicated with ERBSS). With the aim of providing useful data to the scientific community involved in neutron measurements at hadron therapy facilities, an ERBSS experiment was carried out at the Centro di AdroTerapia e Applicazioni Nucleari Avanzate (CATANA) of INFN-LNS (Laboratori Nazionali del Sud), where a proton beam routinely used for ophthalmic cancer treatments is available. The 62 MeV beam was directed towards a PMMA phantom, simulating the patient, and two neutron measurement points were established at 0{sup o} and 90{sup o} with respect to the beam-line. Here the ERBSS of UAB (Universidad Autonoma de Barcelona-Grup de Fisica de les Radiacions) and INFN (Istituto Nazionale di Fisica Nucleare-Laboratori Nazionali di Frascati) were exposed to characterize the 'forward' and 'sideward' proton-induced neutron fields. The use of two ERBSS characterized by different set of spheres, central detectors, and

  6. The Influence of Crystallinity Degree on the Glycine Decomposition Induced by 1 MeV Proton Bombardment in Space Analog Conditions

    Pilling, Sergio; Bordalo, Vinicius; Guaman, Christian F M; Ponciano, Cassia R; da Silveira, Enio F; 10.1089/ast.2012.0877

    2012-01-01

    Glycine is the simplest proteinaceous amino acid and is present in all life-forms on Earth. In aqueous solutions, it appears mainly as zwitterion glycine (+NH3CH2COO-); however, in solid phase, it may be found in amorphous or crystalline (alpha, beta, and gamma) forms. This molecular species has been extensively detected in carbonaceous meteorites and was recently observed in the cometary samples returned to Earth by NASA's Stardust spacecraft. We present an experimental study on the destruction of zwitterionic glycine crystals at room temperature by 1 MeV protons, in which the dependence of the destruction rates of the alpha-glycine and beta-glycine crystals on bombardment fluence is investigated. The samples were analyzed in situ by FTIR spectrometry at different proton fluences at under ultrahigh vacuum conditions at the Van de Graaff accelerator lab at PUC-Rio, Brazil. The dissociation cross section of alpha-glycine was observed to be 2.5E-14 cm^-2, a value roughly 5 times higher than the dissociation cro...

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

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

    2005-01-01

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

  8. Structural effects induced by 2.5 MeV proton beam on zeolite 4A: Positron annihilation and X-ray diffraction study

    Structural changes induced by 2.5 MeV proton beam in zeolite 4A were studied at fluences of 1.1016, 8.1016 and 2.1017 ion/cm2. Positron lifetime (LT) measurements were performed in vacuum after a heat treatment to remove the water from samples. X-ray diffraction method (XRD) was also applied to determine the changes in the crystallinity of zeolite. Gradual transformation of the crystalline structure to amorphous one can be observed in dependence of the implanted doses. Combination of LT and XRD provides a consistent view on structural effects induced by H+ beam in zeolite 4A. - Highlights: • Structural effects of zeolite 4A induced by the proton beam depend on the implanted doses. • The amorphization dose for zeolite 4A is approximately 1010 Gy. • The effects of radiation on zeolite could be different for cage structures. • Positron annihilation can become a effective method for studying irradiated zeolites

  9. K-, L- and M-shell x-ray production cross sections by 1–1.3 MeV protons

    Batyrbekov, E., E-mail: batyrbekov@nnc.kz [National Nuclear Centre, Krasnoarmeyskaya 2, Kurchatov 071100 (Kazakhstan); Gorlachev, I., E-mail: I.Gorlachev@gmail.com [Institute of Nuclear Physics, Ibragimov 1, Alatau 050032, Almaty (Kazakhstan); Ivanov, I., E-mail: mind_slide@mail.ru [Institute of Nuclear Physics, Ibragimov 1, Alatau 050032, Almaty (Kazakhstan); Platov, A., E-mail: platov@inp.kz [Institute of Nuclear Physics, Ibragimov 1, Alatau 050032, Almaty (Kazakhstan)

    2014-04-01

    In 2012, our institute had initiated a series of research activities aimed to measure the characteristic x-ray production cross-section, arising from interaction of accelerated particles with target atoms. This paper presents the data of x-ray production cross-sections under excitation of K-, L- and M-shells of target atoms in the range of mass from Mg to Bi by protons of the energies in the range of 1–1.3 MeV. We used the approach based on calculation of x-ray production cross sections through the cross-section of Rutherford backscattering, which can be calculated with high accuracy from the Rutherford formula. Such approach reduces the measurement errors of x-ray cross-sections and thus improves the accuracy of the obtained data. It is further planned to expand the area of research to protons of other energies and heavy charged particles in the energy range of 0.5–1.7 MeV/nucleon.

  10. Stopping power and energy loss straggling of thin Formvar foil for 0.3-2.7 MeV protons and alpha particles

    Mammeri, S.; Ammi, H.; Dib, A.; Pineda-Vargas, C. A.; Ourabah, S.; Msimanga, M.; Chekirine, M.; Guesmia, A.

    2012-12-01

    Stopping power and energy loss straggling data for protons (1H+) and alpha particles (4He+) crossing Formvar thin polymeric foils (thickness of ˜0.3 μm) have been measured in the energy range (0.3-2.7) MeV by using the indirect transmission technique. The determined stopping power data were compared to SRIM-2010, PSTAR or ASTAR calculation codes and then analyzed in term of the modified Bethe-Bloch theory to extract the target mean excitation and ionization potential . A resulting value of ≈(69.2±1.8) eV was deduced from proton stopping data. The measured straggling data were corrected from surface roughness effects due to target thickness inhomogeneity observed by the atomic force microscopy (AFM) technique. The obtained data were then compared to derived straggling values by Bohr's and Bethe-Livingston's classical theories or by Yang's empirical formula. A deviation of ˜40%-80% from the Bohr's straggling value has been observed for all reported energies, suggesting that the Bohr theory cannot be correctly applied to describe the electronic energy loss straggling process with the used low thickness of Formvar foil. The inner-shell contribution of target electrons to energy loss process is also advanced to explain the observed deviation from experiment in case of He+ ions. Finally, the reliability of Bragg's additivity rule was discussed in case of stopping power and straggling results.

  11. Experimental study performed with Diogene detector on the proton-proton and fragment-fragment correlations at small relative momentum, in the Ne + nucleus and Ar + nucleus collisions, between 200 and 1000 MeV per nucleon

    The purpose of this thesis is to present experimental results obtained with the Diogene detector concerning the study of proton-proton and fragment-fragment correlations at small relative momentum in Ne-Nucleus and Ar-Nucleus collisions between 200 and 1000 MeV per nucleon incident energy on different targets. This study takes place in the yield of relativistic heavy ions collisions, from which we hope to obtain detailed informations about the equation of state of the nuclear matter at high density and high temperature. The interferometry technics allows to measure the dimension of the emitting system of the two coincident particles and also the density of this zone knowing the number of participant proton-like. We have displayed the necessity to take into account the experimental bias of the detector to correctly compare experimental to theoretical data. We have also showed that the approximation of the vanishing lifetime of the source seems to be well-founded. The different values of the source size are in good agreement with the participants spectators model. All the corresponding densities are typical of the expansion stage of the fireball. Nevertheless, informations concerning a possible compression of the nuclear matter could be deduced. However, these valuesclearly show that interferometry does not use strong variables, sensitive to the very first stage of the reaction. In conclusion we give the required conditions to obtain better informations about the equation of state of the nuclear matter out of his fundamental state

  12. Calculation of proton-induced reactions on Tellurium isotopes below 60 MeV for medical radioisotope production

    The 123Te(p,n)123I, 124Te(p,n)124I and 124Te(p,2n)123I reactions, among the many reaction channels opened, are the major reactions under consideration from a diagnostic purpose because reaction residuals as the gamma emitters are used for most radiopharmaceutical applications involving radioiodine. Based on the available experimental data, the absorption cross sections and elastic scattering angular distributions of the proton-induced nuclear reaction on Te isotopes below 60 NeV are calculated using the optical model code APMNK. The transmission coefficients of neutron, proton, deuteron, trition and alpha particles are calculated by CUNF code and are fed into the GNASH code. By adjusting level density parameters and the pair correction values of some reaction channels, as well as the composite nucleus state density constants of the pre-equilibrium model, the production cross sections and energy-angle correlated spectra of the secondary light particles, as well as production cross sections and energy distributions of heavy recoils and gamma rays are calculated by the statistical plus pre-equilibrium model code GNAH. The calculated results are analysed and compared with the experimental data taken from the EXFOR. The optimized global optical model parameters give overall agreement with the experimental data over both the entire energy range and all tellurium isotopes. (author)

  13. Charged pion production from neutron--proton collisions at 790 MeV. [Differential cross sections, symmetry

    Thomas, W.R.

    1977-09-01

    The two reactions np ..-->.. nn..pi../sup +/ and np ..-->.. pp..pi../sup -/ were studied at 790 MeV (incident neutron energy). Pion spectra were measured at 10 different angles with a multiwire proportional chamber spectrometer. Approximately 100,000 events were analyzed. The angular distribution of pions in the np center of momentum system (d sigma/d..cap omega..*) was given by ((123.1 +- 2.7) + (88.3 +- 4.9)cos/sup 2/(theta*))(..mu..b/sr). The cross section sigma(np ..-->.. NN..pi../sup +-/) was determined to be 1.92 +- .20 mb by integrating (d sigma/d..cap omega..*) over all angles. The partial cross section for pion production from T = 0 np interactions (sigma/sub 01/) was found to be .1/sub -.1//sup +.5/ mb by using the relation sigma/sub 01/ = 2sigma(np ..-->.. NN..pi../sup +-)--sigma(pp ..-->.. pp..pi../sup 0/). Stronger indications of nonresonant pion production were given by the presence of asymmetries between the positive and negative pion spectra and a comparison of the data with an isobar model calculation.

  14. Design status and future research programme for a sub-critical assembly driven by a proton accelerator with proton energy 660 MeV for experiments on long-lived fission products and minor actinides transmutation (Sad)

    Report presents project for the construction of a low power integral system on the basis of the proton accelerator of energy 660 MeV and sub-critical MOX blanket with uranium-plutonium fuel. Installation includes sub-critical core with a nominal thermal power of 15-20 kW. Multiplication coefficient keff = 0,95 and the accelerator beam power of 0.75-1 kW. The experimental programme for SAD will be focused on solving different aspects of reactor physics, reaction rates measurements and benchmarking. The first conceptual design of the SAD experiment is completed in the form of the ISTC Project Proposal 2267. Realisation of the SAD facility may be expected in about 3-4 years. (author)

  15. Nuclear data evaluation for 237Np, 241Am, 242gAm and 242mAm irradiated by neutrons and protons at energies up to 250 MeV

    Evaluation of nuclear data has been performed for 237Np, 241Am, 242gAm and 242mAm. Neutron data were obtained at energies from 20 to 250 MeV and combined with JENDL-3.3 data at 20 MeV. Evaluation of the proton data has been done from 1 to 250 MeV. The coupled channel optical model was used to obtain angular distributions for elastic and inelastic scattering and transmission coefficients. Pre-equilibrium exciton model and Hauser-Feshbach statistical model were used to describe neutron and charged particles emission from excited nuclei. These evaluation is the first work for producing full sets of evaluated file up to 250 MeV for 237Np and Americium isotopes. (author)

  16. Comparison of human chordoma cell-kill for 290 MeV/n carbon ions versus 70 MeV protons in vitro

    While the pace of commissioning of new charged particle radiation therapy facilities is accelerating worldwide, biological data pertaining to chordomas, theoretically and clinically optimally suited targets for particle radiotherapy, are still lacking. In spite of the numerous clinical reports of successful treatment of these malignancies with this modality, the characterization of this malignancy remains hampered by its characteristic slow cell growth, particularly in vitro. Cellular lethality of U-CH1-N cells in response to different qualities of radiation was compared with immediate plating after radiation or as previously reported using the multilayered OptiCell™ system. The OptiCell™ system was used to evaluate cellular lethality over a broad dose-depth deposition range of particle radiation to anatomically mimic the clinical setting. Cells were irradiated with either 290 MeV/n accelerated carbon ions or 70 MeV accelerated protons and photons and evaluated through colony formation assays at a single position or at each depth, depending on the system. There was a cell killing of approximately 20–40% for all radiation qualities in the OptiCell™ system in which chordoma cells are herein described as more radiation sensitive than regular colony formation assay. The relative biological effectiveness values were, however, similar in both in vitro systems for any given radiation quality. Relative biological effectiveness values of proton was 0.89, of 13–20 keV/μm carbon ions was 0.85, of 20–30 keV/μm carbon ions was 1.27, and >30 keV/μm carbon ions was 1.69. Carbon-ions killed cells depending on both the dose and the LET, while protons depended on the dose alone in the condition of our study. This is the first report and characterization of a direct comparison between the effects of charged particle carbon ions versus protons for a chordoma cell line in vitro. Our results support a potentially superior therapeutic value of carbon particle irradiation

  17. Differential production cross-sections of multiply charged fragments in 800 MeV proton-induced spallation of carbon, aluminum, and nickel

    Differential production cross sections for multiply charged fragments from 800-MeV proton spallation of 12C, 27Al, and natural Ni have been measured at 30 and 90 degrees. The ion fragments were identified by use of a time-of-flight, ΔE-E detector telescope capable of complete particle identification for energies as low as .25 MeV/nucleon. The very short ranges of the particles of interest required the construction of very thin detectors with minimal deadlayer material. The time-pick-off detectors and gas ionization chamber developed are unique, and represent the state of the art in fast timing for time-of-flight measurements and in construction of thin detectors. The resolutions achieved allowed the cross section of 3He, 4He, 6Li, 7Li, 7Be, 9Be, 10Be, 10B, 11B, 11C, 12C, and 13C to be determined, along with those of nitrogen and oxygen without isotope separation. The cross sections were found to have weak angular dependence. Pseudo cross sections were calculated from the 900 data by integration of the differential cross sections from 0 to 25 MeV for each product and multiplication by 4π. Pseudo theoretical cross sections were similarly calculated from theoretical differential cross sections. These differential cross sections were calculated with a Monte Carlo computer code that incorporated the cascade-evaporation model of high-energy nuclear reactions. Implications are drawn for modifications of the model. The results suggest reducing the transparency of the struck nucleus to pions produced in the cascade stage of the reaction model in order that a higher excitation energy be left for the evaporation stage. There is some evidence that evaporations of nuclear aggregates more massive than 4He occur; inclusion of such evaporations should improve the model

  18. An in-beam PET system for monitoring ion-beam therapy: test on phantoms using clinical 62 MeV protons

    Ion therapy allows the delivery of highly conformal dose taking advantage of the sharp depth-dose distribution at the Bragg-peak. However, patient positioning errors and anatomical uncertainties can cause dose distortions. To exploit the full potential of ion therapy, an accurate monitoring system of the ion range is needed. Among the proposed methods to monitor the ion range, Positron Emission Tomography (PET) has proven to be the most mature technique, allowing to reconstruct the β+ activity generated in the patient by the nuclear interaction of the ions, that can be acquired during or after the treatment. Taking advantages of the spatial correlation between positron emitters created along the ions path and the dose distribution, it is possible to reconstruct the ion range. Due to the high single rates generated during the beam extraction, the acquisition of the β+ activity is typically performed after the irradiation (cyclotron) or in between the synchrotron spills. Indeed the single photon rate can be one or more orders of magnitude higher than normal for cyclotron. Therefore, acquiring the activity during the beam irradiation requires a detector with a very short dead time. In this work, the DoPET detector, capable of sustaining the high event rate generated during the cyclotron irradiation, is presented. The capability of the system to acquire data during and after the irradiation will be demonstrated by showing the reconstructed activity for different PMMA irradiations performed using clinical dose rates and the 62 MeV proton beam at the CATANA-LNS-INFN. The reconstructed activity widths will be compared with the results obtained by simulating the proton beam interaction with the FLUKA Monte Carlo. The presented data are in good agreement with the FLUKA Monte Carlo

  19. Annual Cosmic Ray Spectra from 250 MeV up to 1.6 GeV from 1995 - 2014 Measured With the Electron Proton Helium Instrument onboard SOHO

    Kühl, P; Heber, B

    2016-01-01

    The solar modulation of galactic cosmic rays (GCR) can be studied in detail by examining long-term variations of the GCR energy spectrum (e.g. on the scales of a solar cycle). With almost 20 years of data, the Electron Proton Helium INstrument (EPHIN) onboard the SOlar and Heliospheric Observatory (SOHO) is well suited for this kind of investigation. Although the design of the instrument is optimized to measure proton and helium isotope spectra up to 50 MeV nucleon$^{-1}$ , the capability exists to determine proton energy spectra from 250 MeV up to above 1.6 GeV. Therefore we developed a sophisticated inversion method to calculate such proton spectra. The method relies on a GEANT4 Monte Carlo simulation of the instrument and a simplified spacecraft model that calculates the energy-response function of EPHIN for electrons, protons and heavier ions. For validation purposes, proton spectra based on this method are compared to various balloon missions and space instrumentation. As a result we present annual galac...

  20. Annual Cosmic Ray Spectra from 250 MeV up to 1.6 GeV from 1995 - 2014 Measured with the Electron Proton Helium Instrument onboard SOHO

    Kühl, P.; Gómez-Herrero, R.; Heber, B.

    2016-03-01

    The solar modulation of galactic cosmic rays (GCR) can be studied in detail by examining long-term variations of the GCR energy spectrum ( e.g. on the scales of a solar cycle). With almost 20 years of data, the Electron Proton Helium INstrument (EPHIN) onboard the SOlar and Heliospheric Observatory (SOHO) is well suited for this kind of investigation. Although the design of the instrument is optimised to measure proton and helium isotope spectra up to 50 MeV nucleon^{-1}, the capability exists to determine proton energy spectra from 250 MeV up to above 1.6 GeV. Therefore we developed a sophisticated inversion method to calculate such proton spectra. The method relies on a GEANT4 Monte Carlo simulation of the instrument and a simplified spacecraft model that calculates the energy-response function of EPHIN for electrons, protons, and heavier ions. For validation purposes, proton spectra based on this method are compared to various balloon missions and space instrumentation. As a result we present annual galactic cosmic-ray spectra from 1995 to 2014.

  1. Systematic study of three-nucleon force effects in the cross section of the deuteron-proton breakup at 130 MeV

    Kistryn, S; Bodek, K; Deltuva, A; Epelbaum, E; Ermisch, K; Glöckle, W; Golak, J; Kalantar-Nayestanaki, N; Kamada, H; Kis, M; Klos, B; Kozela, A; Kuros-Zolnierczuk, J; Mahjour-Shafiei, M; Meißner, Ulf G; Micherdzinska, A; Nogga, A; Sauer, P U; Skibinski, R; Stephan, E; Sworst, R; Witala, H; Zejma, J; Zipper, W

    2005-01-01

    High precision cross-section data of the deuteron-proton breakup reaction at 130 MeV are presented for 72 kinematically complete configurations. The data cover a large region of the available phase space, divided into a systematic grid of kinematical variables. They are compared with theoretical predictions, in which the full dynamics of the three-nucleon (3N) system is obtained in three different ways: realistic nucleon-nucleon (NN) potentials are combined with model 3N forces (3NF's) or with an effective 3NF resulting from explicit treatment of the Delta-isobar excitation. Alternatively, the chiral perturbation theory approach is used at the next-to-next-to-leading order with all relevant NN and 3N contributions taken into account. The generated dynamics is then applied to calculate cross-section values by rigorous solution of the 3N Faddeev equations. The comparison of the calculated cross sections with the experimental data shows a clear prefernce for the predictions in which the 3NF's are included. The m...

  2. Compositional characterization of lithium titanate ceramic samples by determining Li, Ti and O concentrations simultaneously using PIGE at 8 MeV proton beam

    Lithium titanate is a proposed tritium breeding blanket material in D-T based fusion reactor under International Thermonuclear Experimental Reactor programme. For optimization of sol-gel preparation method and chemical quality control, compositional characterization of Li2TiO3 was carried out by particle induced gamma-ray emission using 8 MeV proton beam at BARC-TIFR pelletron facility. For the first time, a non-destructive method has been standardized for simultaneous determination of Li, Ti and O in this ceramic sample, which is otherwise difficult by various wet-chemical as well as radio-analytical methods. Thick targets of samples, synthetic samples and standards prepared in graphite matrix were used for the experiment. Rutherford backscattering spectrometry method was used for beam current monitoring using a thin Au foil. The gamma-rays at 478, 983 and 6129 keV from 7Li(p, p'γ)7Li, 48Ti(p, p'γ)48Ti and 16O(p, p'γ)16O nuclear reactions, respectively, were measured using high resolution gamma-ray spectrometry and corresponding peak areas were used for concentration calculations by relative method. (author)

  3. North/south hemispheric periodicities in the >25 MeV solar proton event rate during the rising and peak phases of solar cycle 24

    Richardson, Ian; Cane, Hilary

    2016-01-01

    We present evidence that >25 MeV solar proton events show a clustering in time at intervals of ~6 months that persisted during the rising and peak phases of solar cycle 24. This phenomenon is most clearly demonstrated by considering events originating in the northern or southern solar hemispheres separately. We examine how these variations in the solar energetic particle (SEP) event rate are related to other phenomena, such as hemispheric sunspot numbers and areas, rates of coronal mass ejections, and the mean solar magnetic field. Most obviously, the SEP event rate closely follows the sunspot number and area in the same hemisphere. The ~6 month variations are associated with features in many of the other parameters we examine, indicating that they are just one signature of the episodic development of cycle 24. They may be related to the "~150 day" periodicities reported in various solar and interplanetary phenomena during previous solar cycles. The clear presence of ~6 month periodicities in cycle 24 that ev...

  4. Yield of Radionuclides and Isomers Measured in Fragmentation of the ^{nat}W and ^{186}W (97%) Targets with Protons at 630, 420 and 270 MeV

    Karamian, S A; Chaloun, P; Filossofov, D V; Henzl, V; Henzlova, D; Kalinnikov, V G; Korolev, N A; Lebedev, N A; Novgorodov, A F; Collins, C B; Popescu, I I; Ur, C A

    2004-01-01

    Yields and cross sections of the radioactive nuclide formation have been measured via induced activity gamma-spectra after irradiation of the natural composition W and enriched ^{186)W targets at Dubna synchrocyclotron. Spallation and fission products have been represented among the detected nuclides. The high-spin isomers of Hf and Lu were produced and the isomer-to-ground state ratios could be estimated. The nuclide yields have also been calculated using the LAHET code at 6 values of proton energy in the range from 100 to 800 MeV both for ^{nat)W and for enriched ^{186)W targets. Measured isotope yields are generally in agreement with the calculations, however, the code is incapable to predict the isomer-to-ground state ratios. In experiment, it has been shown that the ^{177m}Lu, ^{178m2}Hf and ^{179m2}Hf high-spin isomers are produced with 2.5 times higher yield in the 97% enriched ^{186)W target as compared to the ^{nat)W target at identical irradiations. This makes significance for the creation of high-a...

  5. Effects of 600 MeV proton irradiation on nucleation and growth of precipitates and helium bubbles in a high-purity Al-Mg-Si alloy

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

    Solution treated specimens of a high-purity Al-0.75%Mg-0.42%Si alloy were irradiated with 600 MeV protons at 150 and 240°C to a dose level of 0.47 and 0.55 dpa, respectively. Mg2Si-type precipitates formed during irradiation at 150 and 240°C; at 240°C, however, a large number of precipitates seem...... to have dissolved during the later stages of irradiation. Thermally aged reference specimens have also been investigated. The needle-shaped precipitates in the aged and the irradiated specimens lie along the 〈100〉 matrix directions. At 150°C bubbles were observed only at grain boundaries whereas at...... 240°C bubbles were seen in the grain interior as well as at the grain boundaries. Long rows of bubbles were observed with the same orientation in the matrix as the precipitate needles. Grain boundary bubbles were found to grow faster in the Al-Mg-Si alloy than in the high-purity aluminium...

  6. 1.00 MeV proton radiation resistance studies of single-junction and single gap dual-junction amorphous-silicon alloy solar cells

    Abdulaziz, Salman; Payson, J. S.; Li, Yang; Woodyard, James R.

    1990-01-01

    A comparative study of the radiation resistance of a-Si:H and a-SiGe:H single-junction and a-Si:H dual-junction solar cells was conducted. The cells were irradiated with 1.00-MeV protons with fluences of 1.0 x 10 to the 14th, 5.0 x 10 to the 14th and 1.0 x 10 to the 15th/sq cm and characterized using I-V and quantum efficiency measurements. The radiation resistance of single-junction cells cannot be used to explain the behavior of dual-junction cells at a fluence of 1.0 x 10 to the 15th/sq cm. The a-Si H single-junction cells degraded the least of the three cells; a-SiGe:H single-junction cells showed the largest reduction in short-circuit current, while a-Si:H dual-junction cells exhibited the largest degradation in the open-circuit voltage. The quantum efficiency of the cells degraded more in the red part of the spectrum; the bottom junction degrades first in dual-junction cells.

  7. Experimental determination of residual nuclei formation cross sections in 660 MeV proton reactions with 239Pu and natU

    Experimental cross sections for proton induced reactions of an energy of 660 MeV with various fission products, minor actinides, and 'major' actinides (plutonium, uranium, thorium) are studied. The paper describes 239Pu and natural U experiments; other experiments have already been published or are planned. Cross section determination consist of three parts: experiment, data processing, and mathematical codes simulation of the problem. This paper deals only with experiment description and data processing methodology. 4 irradiation experiments have been performed: 2 with natural uranium targets and 2 with plutonium targets. Each two experiments were identical, differences were only in irradiation time (and of course another sample was used). Uranium samples were in the thin foil form while plutonium was in dioxide form in a duralumin container. Shorter irradiation time experiments were used to observe isotopes with half-lives in the range of minutes and hours while the longer ones were used to observe long-lived isotopes. The irradiated samples were submitted to γ spectroscopy about 5 minutes after the end of irradiation. A total number of 105 uranium spectra and 156 plutonium spectra were acquired. Measured data were processed using standard γ spectrometry methods and standard software packages as well as home-made programs were used to determine cross-sections. Neither final results of processing, nor simulation of plutonium experiment are paper-ready at the moment. Uranium data have partially already been presented, final complete results are planned to be published with plutonium results together in reviewed journal

  8. Systematic study of three-nucleon force effects in the cross section of the deuteron-proton breakup at 130 MeV

    St. Kistryn; E. Stephan; A. Biegun; K. Bodek; A. Deltuva; E. Epelbaum; K. Ermisch; W. Gloeckle; J. Golak; N. Kalantar-Nayestanaki; H. Kamada; M. Kis; B. Klos; A. Kozela; J. Kuros-Zolnierczuk; M. Mahjour-Shafiei; U.-G. Meissner; A. Micherdzinska; A. Nogga; P. U. Sauer; R. Skibinski; R. Sworst; H. Witala; J. Zejma; W. Zipper

    2005-08-11

    High precision cross-section data of the deuteron-proton breakup reaction at 130 MeV are presented for 72 kinematically complete configurations. The data cover a large region of the available phase space, divided into a systematic grid of kinematical variables. They are compared with theoretical predictions, in which the full dynamics of the three-nucleon (3N) system is obtained in three different ways: realistic nucleon-nucleon (NN) potentials are combined with model 3N forces (3NF's) or with an effective 3NF resulting from explicit treatment of the Delta-isobar excitation. Alternatively, the chiral perturbation theory approach is used at the next-to-next-to-leading order with all relevant NN and 3N contributions taken into account. The generated dynamics is then applied to calculate cross-section values by rigorous solution of the 3N Faddeev equations. The comparison of the calculated cross sections with the experimental data shows a clear preference for the predictions in which the 3NF's are included. The majority of the experimental data points is well reproduced by the theoretical predictions. The remaining discrepancies are investigated by inspecting cross sections integrated over certain kinematical variables. The procedure of global comparisons leads to establishing regularities in disagreements between the experimental data and the theoretically predicted values of the cross sections. They indicate deficiencies still present in the assumed models of the 3N system dynamics.

  9. Proton and deuteron inelastic excitation of the 1+ state at E/sub x/ = 5.846 MeV in /sup 208/Pb: Isoscalar character and importance of tensor correlations

    Differential cross sections for /sup 208/Pb(p,p') and /sup 208/Pb(d,d') excitation of the 1+ state at E/sub x/ = 5.846 MeV were measured at E/sub inc/ = 45 MeV. The fact that the measured strengths of both reactions are very similar supports the isoscalar nature of the 1+ state. The comparison of the experimental proton angular distribution to microscopic distorted-wave calculations using random phase approximation wave functions with and without tensor correlations suggests that the isoscalar tensor part of the (π+rho)-exchange potential is too strong

  10. Dosimetry and microdosimetry of 10–220 MeV proton beams with CR-39 and their verifications by calculation of reaction cross sections using ALICE, TALYS and GEANT4 codes

    High- and intermediate-energy protons are not able to directly form a track in a CR-39 etch detector (TED). Such detectors, however, can be used for the detection and dosimetry of the beams of these particles through the registration of secondary charged particles with sufficiently high values of linear energy transfer (LET). High-energy protons (72–220 MeV) and Intermediate-energy protons (10–30 MeV) with low LET values ranging from 1.1 down to 0.4 keV/μm and 5.87 down to 2.40 keV/μm, respectively are considered in this study. It seems to be sufficient to create secondary particles, although the LET values are low. This phenomenon can modify the characteristics of the energy transfer process due to these particles, which should be taken into account when such particles are used for radiobiology studies or for radiotherapy. The importance of these secondary particles was investigated experimentally by means of an LET spectrometer based on a chemically etched track detector in which the tracks of the primary protons are not revealed. Experiments were performed with proton beams available at the Nuclear Research Center for Agriculture and Medicine (NRCAM) in Karaj, Iran and at the National Cancer Center (NCC) in Seoul, Korea with protons of primary energies of about 10–30 MeV and 72–220 MeV respectively. The contribution of the secondary particle dose increases as the proton energy decreases. The origin of the secondary particles in interactions with protons having high and intermediate energies due to various nuclear reactions was calculated by the both ALICE and TALYS computer codes. The secondary microdosimetry doses were also calculated by GEANT4 code. There is large discrepancy between experimental and calculated results in low proton energies. It has been verified that there is a good correlation between the experimentally obtained results and the reaction cross sections predicted by ALICE and TALYS codes.

  11. The Relationship Between CME Properties in the CDAW, CACTUS and SEEDS Catalogs and ?25 MeV Solar Proton Event Intensities

    Richardson, I. G.; von Rosenvinge, T. T.; Cane, H. V.

    2013-12-01

    overcome some of these problems. In particular, a spacecraft in quadrature with the solar source of an SEP event should observe the 'true' width and speed of the associated CME. However, STEREO CME parameters are derived using the CACTUS method, and cannot be directly compared with the LASCO CDAW catalog values that have been so widely used for many years. In this study, we will examine the relationship between the properties of CMEs in various catalogs and the intensities of a large sample of particle events that include ˜25 MeV protons in cycles 23 and 24. In particular, we will compare the proton intensity-speed relationships obtained using the CDAW, CACTUS and SEEDS LASCO catalogs, and also using the CACTUS values from whichever spacecraft (STEREO A, B or SOHO) is best in quadrature with the solar event. We will also examine whether there is any correlation between the width of the CMEs in the automated catalogs and proton intensity, and whether a combination of CME speed and width might improve the correlation with proton intensity.

  12. SU-E-T-408: Determination of KQ,Q0-Factors From Water and Graphite Calorimetry in a 60 MeV Proton Beam

    Rossomme, S [Universite catholique de Louvain, Brussels (Belgium); Renaud, J; Sarfehnia, A; Seuntjens, J [McGill University, Montreal, QC - Canada (Canada); Lee, N; Thomas, R [National Physical Laboratory, Teddington, Middlesex - United Kingdom (United Kingdom); Kacperek, A [The Clatterbridge Cancer Centre NHS Foundation, Wirral (United Kingdom); Bertrand, D [Ion Beam Applications s.a., Louvain-la-Neuve (Belgium); Vynckier, S [Universite catholique de Louvain, Brussels (Belgium); Cliniques UniversitySt. Luc, Brussels (Belgium); Palmans, H [National Physical Laboratory, Teddington, Middlesex - United Kingdom (United Kingdom); MedAustron, Wiener Neustadt (Austria)

    2014-06-01

    Purpose: To reduce the uncertainty of the beam quality correction factor kQ,Q0, for scattered proton beams (SPB). This factor is used in dosimetry protocols, to determine absorbed dose-to-water with ionization chambers. For the Roos plane parallel chambers (RPPICs), the IAEA TRS-398 protocol estimates kQ,Q0-factor to be 1.004(for a beam quality Rres=2 g.cm{sup 2}), with an uncertainty of 2.1%. Methods: A graphite calorimeter (GCal), a water calorimeter (WCal) and RPPICs were exposed, in a single experiment, to a 60 MeV non-modulated SPB. RPPICs were calibrated in terms of absorbed dose-to-water in a 20 MeV electron beam. The calibration coefficient is traceable to NPL's absorbed dose standards. Chamber measurements were corrected for environmental conditions, recombination and polarity. The WCal corrections include heat loss, heat defect and vessel perturbation. The GCal corrections include heat loss and absorbed dose conversion. Except for heat loss correction and its uncertainty in the WCal system, all major corrections were included in the analysis. Other minor corrections, such as beam profile non-uniformity, are still to be evaluated. Experimental kQ,Q0-factors were derived by comparing the results obtained with both calorimeters and ionometry. Results: The absorbed dose-to-water from both calorimeters was found to be within 1.3% with an uncertainty of 1.2%. kQ,Q0-factor for a RPPIC was found to be 0.998 and 1.011, with a standard uncertainty of 1.4% and 0.9% when the dose is based on the GCal and the WCal, respectively. Conclusion: Results suggest the possibility to determine kQ,Q0-values for PPICs in SPB with a lower uncertainty than specified in the TRS-398 thereby helping to reduce uncertainty on absorbed dose-to-water. The agreement between calorimeters confirms the possibility to use GCal or WCal as primary standard in SPB. Because of the dose conversion, the use of GCal may lead to slightly

  13. Double differential cross sections for (p,n) reactions of 18 and 25 MeV protons with isotopes of Cr, Fe, Co, Ni, Cu, Y, Zr, Mo, Pd and Tb

    Cross sections for the inclusive production of neutrons from reactions of 25 MeV protons with 505253Cr, 545658Fe, 59Co, 60Ni, 63Cu, 89Y, 90919294Zr, 929495969798100Mo, 110Pd and 159Tb and of 18 MeV protons with 90919294Zr have been measured with time-of-flight techniques for 16 angles between 3.50 less than or equal to theta/sub lab/ less than or equal to 159.00. After a short presentation of the motivations for these measurements, the experimental set up is discussed with emphasis on the systematic and statistical error sources pertinent to this work, in particular the question of background correction in the continuous parts of the spectra. The main purpose of this report is to make the experimental results of this work (angle integrated spectra, angular distributions) available for distribution, reducing thereby the data required in publication of the results of these experiments. 20 references

  14. Semiconductor detector systems (dE/dx and E) for the detection and mass identification of protons, deuterons, tritons, He3 and alpha particles in the 10 to 30-MeV energy region

    In the 10 to 30-MeV region of energy many different reactions can occur in a charged-particle scattering experiment and, without proper mass identification, complex spectra from different reactions are superimposed and in many cases impossible to analyse. A semiconductor detector system for the detection and mass separation of He3 and alpha particles was described recently by the author. Briefly, a dE/dx p-n junction detector was constructed of a thin wafer of 6000-Ωcm p-type silicon, 0.002 in thick, with a useful area of ∼ 70 mm2. The E detector employed in this study was a 1-cm2 silicon p-n junction. This semiconductor detector system could separate alpha from He3 particles with intensity ratios as high as 100:1 to 1000:1 over a 10 to 25-MeV range of energies. Comparisons between the semiconductor and gas ion chamber dE/dx detectors showed that the energy resolution of the semiconductor detector was improved over the gas ion chamber in accord with the ionization efficiency of the stopping media. This system has been redesigned into a compact package more practical for experimental applications. The advantages and details of this new design will be discussed. The general method has been extended to protons, deuterons and tritons with the use of semiconductor detectors for E and gas ion chambers for dE/dx. Protons, deuterons, and tritons from reactions induced in Be9 by 28-MeV alpha particles have been analysed with these systems and mass-separated spectra of each of the above particles will be shown. Although many of the particles were energetic enough to penetrate completely through the E detector (i.e., > 10-MeV protons) the system was still able to separate the three masses effectively. An experimental lithium-diffused p-n junction with a ∼ 2-mm thick space-charge region detected 15-MeV protons, 17-MeV deuterons, and 15-MeV tritons with ∼ 1% energy resolution and excellent mass separation. The advantages of these systems when applied to low

  15. Excitation functions of proton-induced reactions on natural Nd and production of radionuclides relevant for double beta decay: Completing measurement in 5–35 MeV energy range

    Lebeda, O., E-mail: lebeda@ujf.cas.cz [Nuclear Physics Institute AS CR, v.v.i., Husinec-Řež 130, 250 68 Řež (Czech Republic); Lozza, V.; Petzoldt, J. [Institut für Kern und Teilchenphysik, Technische Universität Dresden, Zellescher Weg 19, 01069 Dresden (Germany); Štursa, J.; Zdychová, V. [Nuclear Physics Institute AS CR, v.v.i., Husinec-Řež 130, 250 68 Řež (Czech Republic); Zuber, K. [Institut für Kern und Teilchenphysik, Technische Universität Dresden, Zellescher Weg 19, 01069 Dresden (Germany)

    2014-09-15

    Cross-sections for the proton-induced reactions on natural neodymium in energy regions 5–10 MeV and 30–35 MeV were measured using the cyclotron U-120M at the Nuclear Physics Institute at Řež near Prague. This measurement completes the investigation previously done in the 10–30 MeV energy range. Results revealed practical production thresholds and secondary maxima and minima in the excitation functions. It allowed for more appropriate calculation of thick target yields and production rates of many longer-lived radionuclides potentially disturbing the search for neutrinoless double beta decay. Measured cross-sections are consistent with our previously published data.

  16. Excitation functions of proton-induced reactions on natural Nd and production of radionuclides relevant for double beta decay: Completing measurement in 5-35 MeV energy range

    Lebeda, O; Petzoldt, J; Stursa, J; Zdychova, V; Zuber, K

    2015-01-01

    Cross-sections for the proton-induced reactions on natural neodymium in energy regions 5-10 MeV and 30-35 MeV were measured using the cyclotron U-120M at the Nuclear Physics Institute at Rez near Prague. This measurement completes the investigation previously done in the 10-30 MeV energy range. Results revealed practical production thresholds and secondary maxima and minima in the excitation functions. It allowed for more appropriate calculation of thick target yields and production rates of many longer-lived radionuclides potentially disturbing the search for neutrinoless double beta decay. Measured cross-sections are consistent with our previously published data.

  17. L{sub i} ({alpha}, {beta}, {gamma}, l) subshell X-ray production cross-sections and theirs emission ratio in Pb and Au for proton energy 1-2.5 MeV

    Ouziane, S [Faculte de Physique, Universite des Sciences et de Technologie Houari Boumediene, BP 32, El Alia, Bab Ezzouar 16111 Alger (Algeria); Amokrane, A [Faculte de Physique, Universite des Sciences et de Technologie Houari Boumediene, BP 32, El Alia, Bab Ezzouar 16111 Alger (Algeria); Toumert, I [Centre de Recherches Nucleaires d' Alger, 2 Bd Frantz Fanon, BP 399, Alger (Algeria)

    2006-05-15

    The L{sub i} ({alpha}, {beta}, {gamma}, l) subshell X-ray production cross-sections for Pb and Au were measured at incident proton energy between 1 to 2.5 MeV. The obtained data are compared to available data given in Sokhi and Crumpton and Orlic and al. compilations. The given data are also compared with the predictions of ECPSSR model. The comparison shows a good agreement.

  18. Li (α, β, γ, l) subshell X-ray production cross-sections and theirs emission ratio in Pb and Au for proton energy 1-2.5 MeV

    The Li (α, β, γ, l) subshell X-ray production cross-sections for Pb and Au were measured at incident proton energy between 1 to 2.5 MeV. The obtained data are compared to available data given in Sokhi and Crumpton and Orlic and al. compilations. The given data are also compared with the predictions of ECPSSR model. The comparison shows a good agreement

  19. Involvement of the Artemis Protein in the Relative Biological Efficiency Observed With the 76-MeV Proton Beam Used at the Institut Curie Proton Therapy Center in Orsay

    Calugaru, Valentin [Institut Curie Centre de Protonthérapie d' Orsay, Centre Universitaire, Orsay (France); Institut Curie, Centre Universitaire, Orsay (France); INSERM U612, Centre Universitaire, Orsay (France); Nauraye, Catherine [Institut Curie Centre de Protonthérapie d' Orsay, Centre Universitaire, Orsay (France); Cordelières, Fabrice P. [Institut Curie, Centre Universitaire, Orsay (France); Biard, Denis [Centre d' Etude Atomique, Direction des Sciences du Vivant, Institut des Maladies Emergentes et des Thérapies Innovantes, Service d' Etude des Prions et des Infections Atypiques, Fontenay-aux-Roses (France); De Marzi, Ludovic [Institut Curie Centre de Protonthérapie d' Orsay, Centre Universitaire, Orsay (France); Hall, Janet; Favaudon, Vincent [Institut Curie, Centre Universitaire, Orsay (France); INSERM U612, Centre Universitaire, Orsay (France); Mégnin-Chanet, Frédérique, E-mail: frederique.megnin@inserm.fr [Institut Curie, Centre Universitaire, Orsay (France); INSERM U612, Centre Universitaire, Orsay (France)

    2014-09-01

    Purpose: Previously we showed that the relative biological efficiency for induced cell killing by the 76-MeV beam used at the Institut Curie Proton Therapy Center in Orsay increased with depth throughout the spread-out Bragg peak (SOBP). To investigate the repair pathways underlying this increase, we used an isogenic human cell model in which individual DNA repair proteins have been depleted, and techniques dedicated to precise measurements of radiation-induced DNA single-strand breaks (SSBs) and double-strand breaks (DSBs). Methods and Materials: The 3-Gy surviving fractions of HeLa cells individually depleted of Ogg1, XRCC1, and PARP1 (the base excision repair/SSB repair pathway) or of ATM, DNA-PKcs, XRCC4, and Artemis (nonhomologous end-joining pathway) were determined at the 3 positions previously defined in the SOBP. Quantification of incident SSBs and DSBs by the alkaline elution technique and 3-dimensional (3D) immunofluorescence of γ-H2AX foci, respectively, was performed in SQ20 B cells. Results: We showed that the amount of SSBs and DSBs depends directly on the particle fluence and that the increase in relative biological efficiency observed in the distal part of the SOBP is due to a subset of lesions generated under these conditions, leading to cell death via a pathway in which the Artemis protein plays a central role. Conclusions: Because therapies like proton or carbon beams are now being used to treat cancer, it is even more important to dissect the mechanisms implicated in the repair of the lesions generated by these particles. Additionally, alteration of the expression or activity of the Artemis protein could be a novel therapeutic tool before high linear energy transfer irradiation treatment.

  20. Involvement of the Artemis Protein in the Relative Biological Efficiency Observed With the 76-MeV Proton Beam Used at the Institut Curie Proton Therapy Center in Orsay

    Purpose: Previously we showed that the relative biological efficiency for induced cell killing by the 76-MeV beam used at the Institut Curie Proton Therapy Center in Orsay increased with depth throughout the spread-out Bragg peak (SOBP). To investigate the repair pathways underlying this increase, we used an isogenic human cell model in which individual DNA repair proteins have been depleted, and techniques dedicated to precise measurements of radiation-induced DNA single-strand breaks (SSBs) and double-strand breaks (DSBs). Methods and Materials: The 3-Gy surviving fractions of HeLa cells individually depleted of Ogg1, XRCC1, and PARP1 (the base excision repair/SSB repair pathway) or of ATM, DNA-PKcs, XRCC4, and Artemis (nonhomologous end-joining pathway) were determined at the 3 positions previously defined in the SOBP. Quantification of incident SSBs and DSBs by the alkaline elution technique and 3-dimensional (3D) immunofluorescence of γ-H2AX foci, respectively, was performed in SQ20 B cells. Results: We showed that the amount of SSBs and DSBs depends directly on the particle fluence and that the increase in relative biological efficiency observed in the distal part of the SOBP is due to a subset of lesions generated under these conditions, leading to cell death via a pathway in which the Artemis protein plays a central role. Conclusions: Because therapies like proton or carbon beams are now being used to treat cancer, it is even more important to dissect the mechanisms implicated in the repair of the lesions generated by these particles. Additionally, alteration of the expression or activity of the Artemis protein could be a novel therapeutic tool before high linear energy transfer irradiation treatment

  1. 800-MeV magnetic-focused flash proton radiography for high-contrast imaging of low-density biologically-relevant targets using an inverse-scatter collimator

    Freeman, Matthew S.; Allison, Jason; Espinoza, Camilo; Goett, John Jerome; Hogan, Gary; Hollander, Brian; Kwiatkowski, Kris; Lopez, Julian; Mariam, Fesseha; Martinez, Michael; Medina, Jason; Medina, Patrick; Merrill, Frank E.; Morley, Deborah; Morris, Chris; Murray, Matthew; Nedrow, Paul; Saunders, Alexander; Schurman, Tamsen; Sisneros, Thomas; Tainter, Amy; Trouw, Frans; Tupa, Dale; Tybo, Josh; Wilde, Carl

    2016-03-01

    Proton radiography shows great promise as a tool to guide proton beam therapy (PBT) in real time. Here, we demonstrate two ways in which the technology may progress towards that goal. Firstly, with a proton beam that is 800 MeV in energy, target tissue receives a dose of radiation with very tight lateral constraint. This could present a benefit over the traditional treatment energies of ~200 MeV, where up to 1 cm of lateral tissue receives scattered radiation at the target. At 800 MeV, the beam travels completely through the object with minimal deflection, thus constraining lateral dose to a smaller area. The second novelty of this system is the utilization of magnetic quadrupole refocusing lenses that mitigate the blur caused by multiple Coulomb scattering within an object, enabling high resolution imaging of thick objects, such as the human body. This system is demonstrated on ex vivo salamander and zebrafish specimens, as well as on a realistic hand phantom. The resulting images provide contrast sufficient to visualize thin tissue, as well as fine detail within the target volumes, and the ability to measure small changes in density. Such a system, combined with PBT, would enable the delivery of a highly specific dose of radiation that is monitored and guided in real time.

  2. Cascade phonon-assisted trapping of positrons by divacancies in n-FZ-Si(P) single crystals irradiated with 15 MeV protons

    Arutyunov, N. Yu., E-mail: n-arutyunov@yahoo.com [Martin Luther University Halle, Department of Physics, 06120 Halle, Germany and Inst. of Ion-Plasma and Laser Technologies (Inst. of Electronics), 700187 Tashkent (Uzbekistan); Emtsev, V. V.; Oganesyan, G. A. [Ioffe Physico-Technical Institute, 194021 St. Petersburg (Russian Federation); Krause-Rehberg, R.; Kessler, C. [Martin Luther University Halle, Department of Physics, 06120 Halle (Germany); Elsayed, M. [Martin Luther University Halle, Department of Physics, 06120 Halle, Germany and Minia university, Faculty of Science, Physics Department, P.O. box 61519 Minia (Egypt); Kozlovski, V. V. [St. Petersburg State Polytechnic University, 195251 St. Petersburg (Russian Federation)

    2014-02-21

    The trapping of positrons by the radiation defects in moderately doped oxygen-lean n-FZ-Si(P) single crystal irradiated with 15 MeV protons has been investigated in a comparative way using the positron lifetime spectroscopy and Hall effect measurements. The experiments were carried out within a wide temperature interval ranging from 25 K – 29 K to 300 K. The positron trapping rate for divacancies was reconstructed in the course of many-stage isochronal annealing. The concentration and the charged states of divacancies (V{sub 2}{sup −} and V{sub 2}{sup −−}) were estimated. The temperature dependency of the trapping cross section of positrons by the negatively charged divacancies is in a good agreement with the data of calculations based on the assumptions of the cascade phonon-assisted mechanism of exchange of the energy between the positron and acoustic long-wave phonons. Obeying ∼ T{sup −3} law, the cross-section of the trapping of positrons by divacancies changes considerably ranging from ∼1.7×10{sup −12} cm{sup 2} (66 – 100 K) to ∼2×10{sup −14} cm{sup 2} (≈ 250 K). The characteristic length of trapping of the positron by V{sub 2}{sup −−} divacancy was estimated to be l{sub 0}(V{sub 2}{sup −−})≈(3.4±0.2)×10{sup −8} cm.

  3. Preliminary design of high-power wave-guide/transmission system for multimegawatt CW requirements of 100 MeV proton LINAC

    Purushottam Shrivastava; Y D Wanmode; P R Hannurkar

    2002-11-01

    Development of a 100 MeV CW proton LINAC has been planned at CAT. This LINAC will be needing CW rf power in the frequency ranges of 350 MHz and 700 MHz for its RFQ and DTL/CCDTL/SFDTL structures respectively. The power to the accelerating structures will be produced by either 1 MW CW or 250 kW CW klystrons/inductive output tubes (HOM IOTs). The power needed by respective feed points in the structure is max. 250 kW which will be powered by splitting the power from 1 MW klystron/klystrode into four channels by using a wave-guide system. In case of using 250 kW tubes the power to the structures will be provided directly from each tube. Two types of wave-guide transmission system have been considered, viz, WR 2300 for 350 MHz rf needs and WR 1500 for 700 MHz rf needs. The typical wave-guide system has been designed using the 1 MW CW klystron followed by wave-guide filter, dual directional coupler, high-power circulator, three 3 dB magic TEE power dividers to split the main channel into four equal channels of 250 kW each. Each individual channel has dual directional couplers, flexible wave-guide sections and high power ceramic vacuum window. The circulator and each power divider is terminated into the isolated ports by high power CW loads. Out of the four channels three channels have phase shifters. Present paper describes the technological aspects and design specifications-considerations for these stringent requirements.

  4. Cross-sections measurements of the residual nuclei in the spallation of 136Xe on proton at 500 A. MeV

    Full text: Interactions between relativistic light projectiles and heavy target nuclei, so called spallation reactions, have gained in the last decade new interest due to the their applications as neutron or radioactive ion beam sources, but also for their implications in understanding the dynamics of nuclear matter [1]. In this work we have measured the isotopic production cross sections of the residual nuclei issued in collisions of 136Xe projectiles at 500 A MeV onto a proton target. The comparison of these results to previously measured cross sections in 136Xe+p at 1 GeV per nucleon [2] and other systems at different energies, will allow us to better understand the role that neutrons play in spallation reactions as well as the energy dissipation mechanism. More than 400 fragmentation residues produced in this reaction have been identified using inverse kinematics in the Fragment Separator (FRS) [3] at the GSI facility in Darmstadt (Germany). The momentum distribution of all reaction products was measured in different magnetic settings of the spectrometer in order to determine their velocities. The production cross sections were determined from the normalization of the production yields by the beam intensity and the target thickness. The measured results will allow us to benchmark fragmentation codes like EPAX [4] and COFRA[5]. [1] J. Benlliure , Lect Notes Phys,700,191 (2006). [2] P. Napolitani, et al., Phys. Rev. C76, 064609 (2007). [3] H. Geissel, et al., Nucl. Instrum Methods B70, 286 (1992). [4] K. Suemmerer and B. Blank, Phys. Rev. C61, 034607 (2000) [5] J. Benlliure, et. al., Nucl. Phys. A660, 87 (1999). (author)

  5. Cross-sections measurements of the residual nuclei in the spallation of {sup 136}Xe on proton at 500 A. MeV

    Giot, L. [GSI, Darmstadt (Germany); Alcantara-Nunez, J.; Benlliure, J.; Perez-Loureiro, D. [Universidade de Santiago de Compostela, La Coruna (Spain)

    2012-07-01

    Full text: Interactions between relativistic light projectiles and heavy target nuclei, so called spallation reactions, have gained in the last decade new interest due to the their applications as neutron or radioactive ion beam sources, but also for their implications in understanding the dynamics of nuclear matter [1]. In this work we have measured the isotopic production cross sections of the residual nuclei issued in collisions of {sup 136}Xe projectiles at 500 A MeV onto a proton target. The comparison of these results to previously measured cross sections in {sup 136}Xe+p at 1 GeV per nucleon [2] and other systems at different energies, will allow us to better understand the role that neutrons play in spallation reactions as well as the energy dissipation mechanism. More than 400 fragmentation residues produced in this reaction have been identified using inverse kinematics in the Fragment Separator (FRS) [3] at the GSI facility in Darmstadt (Germany). The momentum distribution of all reaction products was measured in different magnetic settings of the spectrometer in order to determine their velocities. The production cross sections were determined from the normalization of the production yields by the beam intensity and the target thickness. The measured results will allow us to benchmark fragmentation codes like EPAX [4] and COFRA[5]. [1] J. Benlliure , Lect Notes Phys,700,191 (2006). [2] P. Napolitani, et al., Phys. Rev. C76, 064609 (2007). [3] H. Geissel, et al., Nucl. Instrum Methods B70, 286 (1992). [4] K. Suemmerer and B. Blank, Phys. Rev. C61, 034607 (2000) [5] J. Benlliure, et. al., Nucl. Phys. A660, 87 (1999). (author)

  6. Measurement of helium and hydrogen yield from irradiation of metals and alloys to ∼15 dpa in mixed spectra of 500-800 MeV protons and spallation neutrons

    Measurements have been performed of the retained helium and hydrogen levels of both pure element dosimeter foils and various structural alloys irradiated at temperatures between 30 and 60 deg. C in the Los Alamos Neutron Science Center (LANSCE) as part of the Accelerator Production of Tritium (APT) program. The elements employed as dosimeters were Al, Fe, Ni, Co and Cu. The alloys were Inconel 718, AISI 304 and 316, 9Cr-1Mo and Al 6061. Specimens irradiated to displacement levels ranging from 0.6 to ∼14 dpa were examined. Depending on the location of the individual specimen with respect to the incident proton beam, the spectral environment consisted of protons ranging downward from the incident 800 MeV to perhaps 550 MeV and a wide energy spectra of spallation neutrons. The relative contribution of neutrons to both the displacement damage level and the gas generation rates increases for specimens at the edges of the incident proton beam. The retained gas levels are a function of the elemental identity or alloy composition, spectral averaged production rates, specimen thickness, irradiation temperature and irradiation induced microstructure. While very little loss of helium is expected, significant amounts of both energetic and diffusional losses of hydrogen probably occur in the specimens during irradiation. In spite of the apparent complexity of the compositional and spectral environment, it is possible to extract very good estimates of the elemental helium generation cross sections as a function proton energy across relatively narrow energy range of ∼550-800 MeV. The data are elevated with assistance of the LAHET code system to separate the neutron contribution from the proton contribution to both gas and dpa. This effort is aided by the fact that gas generation cross section increase with energy almost in direct proportion to the dpa cross section in this proton energy range. This also allows extrapolation of these results to protons energies > 800 MeV. Due

  7. Fission Cross-Sections of Ta181, Re, Pt, Au197, Pb, Bi, Th, And U235 For Protons With An Energy Of 150-660 MeV

    The measurements were carried out on the synchrocyclotron of the Joint Institute for Nuclear Research, wirha maximum proton energy of 660 MeV. The fission events were recorded by visual observation of the fission-fragment tracks left on glass after treating. The absolute recording efficiency was determined by (he number of U2'35 and Pu239 fissions in a known thermal-neutron flux, and the number of U235 fissions in a neutron fluxfroma Ra-α-Be standard source. The proton flux was determined by measuring the absolute number of β-disintegrations of Na24 occurring in the Al27 (p. 3pn) Na24 reaction (whose cross-section is known with an accuracy of ± 5%), using a scintillation gamma-spectrometer. Samples were irradiated both in an external proton beam and within the chamber of the synchrocyclotron. The fission cross-sections were measured in rhe proton energy range 150-660 MeV. The corrections applied are discussed. The results of the measurements are compared with earlier figures, and the dependence of fissility of the nuclei investigated Dn the parameter Z2/A is determined. (author)

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

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

    2016-01-01

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

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

    Activation cross-sections data of longer-lived products of proton induced nuclear reactions on dysprosium were extended up to 65 MeV by using stacked foil irradiation and gamma spectrometry experimental methods. Experimental cross-sections data for the formation of the radionuclides 159Dy, 157Dy, 155Dy, 161Tb, 160Tb, 156Tb, 155Tb, 154m2Tb, 154m1Tb, 154gTb, 153Tb, 152Tb and 151Tb are reported in the 36–65 MeV energy range, and compared with an old dataset from 1964. The experimental data were also compared with the results of cross section calculations of the ALICE and EMPIRE nuclear model codes and of the TALYS nuclear reaction model code as listed in the latest on-line libraries TENDL 2013. - Highlights: • Proton induced reactions on natural dysprosium up to 65 MeV. • Stacked foil irradiation including monitor and energy degrader foils. • Comparison of experimental results with the ALICE, EMPIRE and TALYS theoretical codes. • Calculation and comparison of thick target integral yields. • Discussion of application fields

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

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

    2016-01-01

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

  11. The correlation of the 10 to 30 MeV proton flux from the NOAA satellites and the Thule 30 MHz riometer. Technical memo

    There is a requirement for realtime specification of riometer absorption in the polar cap region using proton flux measured with satellite-borne detectors. The proton flux data from the NOAA series of satellites and the Thule 30 MHz riometer data satisfy this requirement. A study was done to correlate these two parameters within state-of-the-art theoretical reasoning

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

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

    2012-01-01

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

  13. Parity Violation in Proton-Proton Scattering

    van Oers, W. T. H.; collaboration, for E497

    1997-01-01

    Measurements of parity-violating longitudinal analyzing powers (normalized asymmetries) in polarized proton-proton scattering provide a unique window on the interplay between the weak and strong interactions between and within hadrons. Several new proton-proton parity violation experiments are presently either being performed or are being prepared for execution in the near future: at TRIUMF at 221 MeV and 450 MeV and at COSY (Kernforschungsanlage Juelich) at 230 MeV and near 1.3 GeV. These ex...

  14. neutron-proton elastic scattering between 200 and 500 MeV - 2. Measurement of Rsub(t) and Asub(t)

    The Wolfenstein parameters Rsub(t) and Asub(t) have been measured in free np elastic scattering at 220, 325, 425 and 495 MeV at 100 intervals in the centre of mass range 60 to 1600, with errors typically +- 0.05. (author)

  15. Measurements of the spin observables DNN' and P in inelastic proton scattering from 12C and 16O at 200 MeV

    The determination of polarization transfer observable for (rvec p, rvec p') reactions in intermediate energies provides a rich source of information on both the effective nucleon-nucleus interaction and the nuclear structure. The primary motivation for this work was to exploit the increased sensitivity predicted for these polarization transfer observable to the spin-dependent terms of the effective interaction used to describe nucleon-nucleus scattering at intermediate energies. To carry out this work the author has designed, built, and calibrated a polarimeter for the focal plane of the high resolution K600 Spectrometer. By using a low-energy beamline polarimeter and this Focal Plane Polarimeter, he has measured the normal-component spin observables DNN', P, and Ay at 200 MeV for the 1+, T = 0 (12.71 MeV) and T = 1 (15.11 MeV) states in 12C and for the 4-, T = 0 (17.79 and 19.80 MeV) and T = 1 (18.98 MeV) states in 16O. Measurements were made at five angles for the 12C transitions, at momentum transfers between 80 and 250 MeV/c, and at three angles for 16O, at momentum transfers of 225 to 400 MeV/c. The transitions chosen for this work have fairly well-determined nuclear structure and unnatural parity which maximizes the predicted sensitivity to the spin-dependent terms of the effective interaction. The results from this work will be used to address questions concerning the need for a relativistic interaction and how to incorporate corrections to the nuclear interaction due to the nuclear medium

  16. Contribution to proton transport simulation from the MeV range to the keV range by the Monte-Carlo method

    This study settles on a contribution to the elaboration of slow protons transport simulation. Atomic inner shell ionization is studied in the Plane Wave Born Approximations and in the Binary Encounter Approximation. BRINKMAN-KRAMER's theory and DMITRIEV's theory are used to study charge exchange phenomena. Protons slowing down is studied with the BRICE's stopping power, with the VAVILOV and SYMON's energy straggling distributions and with the MOLIERE, KEIL and MEYER's angular deflexion distributions. Transport simulation is made with Monte Carlo Method; K electrons motion is also taken into account

  17. Prospects of warm dense matter research at HiRadMat facility at CERN using 440 MeV SPS proton beam

    Tahir, N A; Schmidt, R; Shutov, A; Piriz, A R

    2013-01-01

    In this paper we present numerical simulations of heating of a solid copper cylinder by the 440 GeV proton beam delivered by the Super Proton Synchrotron (SPS) at CERN. The beam is made of 288 proton bunches while each bunch comprises of 1.15$1011 so that the total number of protons in the beam is about 1.3$1013. The bunch length is 0.5 ns while two neighboring bunches are separated by 25 ns so that the beam duration is 7.2 ms. Particle intensity distribution in the transverse direction is a Gaussian and the beam can be focused to a spot size with s 1⁄4 0.1 mme1.0 mm. In this paper we present results using two values of s, namely 0.2 mm and 0.5 mm, respectively. The target length is 1.5 m with a radius 1⁄4 5 cm and is facially irradiated by the beam. The energy deposition code FLUKA and the two-dimensional hydrodynamic code BIG2 are employed using a suitable iteration time to simulate the hydrodynamic and the thermodynamic response of the target. The primary purpose of this work was to design fixed target...

  18. Radiative capture and charge exchange of negative pions on protons at 26.4 and 39.3 MeV

    The π-p->γn and π-p->π0n reactions were studied at laboratory pion kinetic energies of 27.4 and 39.3 MeV for 9 angles. The differential cross sections of the π-p->γn reaction are compared with previous data and with several calculations. The π-p->π0n differential cross sections were obtained by unfolding the energy spectra of the π0 γ-ray decays. Pion-nucleon phase shifts and scattering lengths are deduced and good agreement is obtained with the elastic channels, supporting isospin invariance. (orig.)

  19. Radiative capture and charge exchange of negative pions on protons at 27.4 and 39.3 MeV

    The π-p → γn and π-p → π0n reactions were studied at laboratory pion kinetic energies of 27.4 and 39.3 MeV for 9 angles. The differential cross-sections of the π-p → γn reaction are compared with previous data and with several calculations. The π-p → π0n differential cross-sections were obtained by unfolding the energy spectra of the π0 γ-ray decays. Pion-nucleon phase shifts and scattering lengths are deduced and good agreement is obtained with the elastic channels, supporting isospin invariance

  20. Sudden intensity increases and radial gradient changes of cosmic ray MeV electrons and protons observed at Voyager 1 beyond 111 AU in the heliosheath

    Webber, W. R.; McDonald, F. B.; Cummings, A. C.; Stone, E. C.; Heikkila, B.; Lal, N.

    2012-01-01

    Voyager 1 has entered regions of different propagation conditions for energetic cosmic rays in the outer heliosheath beginning at a distance of about 111 AU from the Sun. This conclusion is based on the fact that the low energy 6-14 MeV galactic electron intensity suddenly increased by ~20% over a time period \\leg 10 days and the electron radial intensity gradient abruptly decreased from ~19%/AU to ~8%/AU at 2009.7 at a radial distance of 111.2 AU. A sudden radial gradient change was also obs...

  1. Proton induced K X-ray production cross sections of the elements Al, Si, Ti, Fe, and Ni in the 0.7-2.0 MeV energy range

    Bertol, Ana Paula Lamberti; Hinrichs, Ruth; Vasconcellos, Marcos A. Z.

    2015-12-01

    Proton induced K-shell ionization cross sections were obtained for the elements Al, Si, Ti, Fe, and Ni in the 0.7-2.0 MeV energy range. The accuracy of these fundamental parameters is essential for PIXE analysis and the data in the literature present a considerable spread, mainly for Al and Si. The values obtained for Ti, Fe and Ni are compatible with the current theories and the experimental results reported in the literature. However, Al and Si cross sections present important differences from theoretical and experimental data. We propose values for the fluorescent yields of Al and Si that are compatible with recent results and can be incorporated in the computations of K X-ray production cross sections.

  2. Enhancement of critical current density in a Ca0.85La0.15Fe(As0.92Sb0.08)2 superconductor with T c = 47 K through 3 MeV proton irradiation

    Park, Akiyoshi; Mine, Akinori; Yamada, Tatsuhiro; Ohtake, Fumiaki; Akiyama, Hiroki; Sun, Yue; Pyon, Sunseng; Tamegai, Tsuyoshi; Kitahama, Yutaka; Mizukami, Tasuku; Kudo, Kazutaka; Nohara, Minoru; Kitamura, Hisashi

    2016-05-01

    We examine the critical current density (J c) of Ca{}1-xLa x Fe(As{}1-ySb y )2, a 112-type iron-based superconductor (IBS) with {T}{{c}} = 47 K, via magneto-optical imaging and magnetization measurements. We assert that the large self-field J c of 2.2× {10}6 A cm- 2 at 2 K is a strong indication that it is a bulk superconductor with spatially homogeneous superconductivity. A 2.8-fold enhancement in J c to 6.2× {10}6 A cm- 2 was achieved through artificially engineering pinning centers by irradiating 3 MeV protons with a total dosage of 1.0× {10}16 {{cm}}-2. The results not only demonstrate the potential of 112-type IBSs for application but also enrich the current understanding of the role of artificial defects in IBSs.

  3. Measurement of target fragments produced by 160 MeV proton beam in aluminum and polyethylene with CR-39 plastic nuclear track detectors

    Ambrožová, Iva; Yasuda, N.; Kodaira, S.; Sihver, L.

    2014-01-01

    Roč. 64, MAY (2014), s. 29-34. ISSN 1350-4487 R&D Projects: GA AV ČR KJB100480901; GA AV ČR IAA100480902; GA MŠk LG14004 Institutional support: RVO:61389005 Keywords : target fragments * high-energy protons * Aluminium * Polyethylene * plastic nuclear track detectors * CR-39 Subject RIV: BG - Nuclear, Atomic and Molecular Physics, Colliders Impact factor: 1.213, year: 2014

  4. Relative Biological Effectiveness Variation Along Monoenergetic and Modulated Bragg Peaks of a 62-MeV Therapeutic Proton Beam: A Preclinical Assessment

    Chaudhary, Pankaj; I Marshall, Thomas; Perozziello, Francesca M; Manti, Lorenzo; Currell, Frederick J.; Hanton, Fiona; McMahon, Stephen J; Kavanagh, Joy N.; Cirrone, Giuseppe Antonio Pablo; Romano, Francesco; Prise, Kevin M.; SCHETTINO, Giuseppe

    2014-01-01

    iological optimization of proton therapy critically depends on detailed evaluation of relative biological effectiveness (RBE) variations along the Bragg curve. The clinically accepted RBE value of 1.1 is an oversimplification, which disregards the steep rise of linear energy transfer (LET) at the distal end of the spread-out Bragg peak. We observed significant cell killing RBE variations dependent on beam modulation, intrinsic radiosensitivity, and LET in agreement with the LEM predicted valu...

  5. Nonequilibrium effects in the proton neutral fraction emerging from solids bombarded with MeV H0, H+, H2+ and H3+ beams

    Non-equilibrated neutral fractions have been investigated in hydrogen beams transmitted through carbon foils bombarded with H0, H2+ and H3+ projectiles having energies from 0.5 to 2.4MeV/amu. Measurements with neutral projectiles provide a direct determination of the charge exchange cross sections for fast protons in solids. The fact that the solid cross sections have been found close to the corresponding gas cross sections is discussed and confronted with existing theories. For very short dwell times the role played by projectile electrons in the neutral atom production is demonstrated and it is shown that the approach to equilibrium follows essentially the same law for H0, H2+ and H3+ projectiles. An overproduction of neutrals has also been observed with molecular ion projectiles for longer dwell times. An explanation of this effect is suggested in terms of a multi-step process in which an electron gains correlation with one proton and is finally captured by another proton of the same cluster. Angular distributions of neutrals produced from incident molecular beams indicate the possible formulation of a repulsive molecular state on emergence from the foil

  6. Excitation functions of residual nuclei production from 40–2600 MeV proton-irradiated 206,207,208,natPb and 209Bi

    Yu E Titarenko; V F Batyaev; V M Zhivun; V O Kudryashov; K A Lipatov; A V Ignatyuk; S G Mashnik

    2007-02-01

    The work is aimed at experimental determination of the independent and cumulative yields of radioactive residual nuclei produced in intermediate-energy proton-irradiated thin targets made of highly isotopic enriched and natural lead (206,207,208,natPb) and 209Bi. 5972 radioactive product nuclide yields have been measured in 55 thin targets induced by 0.04, 0.07, 0.10, 0.15, 0.25, 0.6, 0.8, 1.2, 1.4, 1.6 and 2.6 GeV protons extracted from the ITEP U-10 proton synchrotron. The measured data have been compared with data obtained at other laboratories as well as with theoretical simulations by seven codes. We found that the predictive power of the tested codes is different but is satisfactory for most of the nuclides in the spallation region, though none of the codes agree well with the data in the whole mass region of product nuclides and all should be improved further.

  7. Proton induced reactions on natural tellurium up to 63 MeV: data validation and investigation of possibility of 124I production

    Excitation functions of the reactions natTe (p, xn)120g,121,123,124,125,126,128,130I were measured from their respective thresholds up to 63 MeV via the stacked foil technique. Thin targets were prepared by a vacuum deposition method. Irradiations were performed using AVF 930 cyclotron at the National Institute of Radiological Sciences. The concord and conflict between our excitation studies and the available literature data are shown. The high values of our cross sections for 125I in comparison to some literature data are discussed. Our cross sections measurements validated some of the literature data obtained using enriched target isotopes. The integral yields of iodine radionuclides were deduced from the measured excitation curves. The estimated yield of 124I via the natTe(p, xn) process over the energy range Ep = 57 → 53 MeV is 16.7 MBq/μA h. The level of the radionuclidic impurities 125I and 126I is, however, rather high, so that it is not meaningful to produce 124I using natTe as target material. (orig.)

  8. Formation and de-excitation of hot nuclei in reactions induced by proton beams (475 MeV and 2 GeV) and 3He beam (2 GeV)

    We are studying the formation and the de-excitation of hot nuclei created in reactions induced by light high energy projectiles. These reactions, described in a two step model: an intranuclear cascade followed by an evaporation phase, produce nuclei in which the collective modes (compression, rotation, deformation) are weakly excited. By measuring the neutron multiplicities, event by event with ORION, and the light charged particle energies and multiplicities one can evaluate the excitation energy distribution of the nuclei. At the same time, theoretical simulations are carried out using the intranuclear cascade code developed by J. Cugnon and the statistical de-excitation code GEMINI. The good agreement with experimental results indicate that 10% of the p-nucleus interactions lead to temperatures greater than 5 MeV. The observation of the fission of a nucleus with a temperature close to 5 MeV shows that the nucleus behaves as a set of bound nucleons and, that the temperature stability limit is not yet reached. The observed decline of fission probability at high excitation energies is most likely to be correlated to the appearance of an other de-excitation process (evaporation residues emission or multifragmentation) which could not be experimentally detected. Finally, in the last chapter, we briefly present the principle of transmutation for long-lived nuclear waste with a proton accelerator and underline the interest of the present work in such studies. (author). 54 refs., 80 figs., 13 tabs

  9. Study of some quasi-free reactions induced by 58 MeV protons on 9Be, 12C and 14N

    (p,pd) (p,pt) and (p,p3H) quasi-free scattering have been studied at 58 MeV, together with some quasi-free reactions, on three 1 p shell nuclei: 9Be, 12C and 14N by detecting two outgoing particles. A good energy resolution permitted the observation of several low-lying levels of the residual nuclei. Experimental results have been analyzed in the frame of the distorded wave impulse approximation. If such a model is able to reproduce most of the results and gives clear evidence of the quasi-free process, it is not always possible to obtain good quantitative results. However, informations concerning nuclear structure and reaction mechanism are discussed and some spectroscopic informations extracted

  10. Low carrier removal rates and annealing behavior of thermally diffused p+n (Cd,S) InP structures after 1013cm-2 3MeV proton irradiation

    Recently on bare p+n (Cd,S) InP diffused cells the authors recorded AMO, 25C VOC values exceeding 880 mV. In this work they present some of their most recent results showing much lower carrier removal rates in the emitter of p+n (Cd,S) diffused structures as compared to p+n (Zn,S) structures after irradiation with 1013cm-2, 3 MeV protons. They also show the complete recovery of emitter carrier concentration profiles of p+n (Cd,S) structures after about 2 months in dark at room temperature, a behavior they have not observed for the p+n (Zn,S) structures. The drop in ISC, FF and efficiency of diffused p+n (Cd,S) InP cells after proton irradiation is lower than previously reported values for n+p (Si,Zn) InP cells fabricated by MOCVD or n+p (S,Zn) InP cells fabricated by diffusion

  11. Experimental determination of residual nuclei formation cross sections in 660 MeV proton reactions with Pu-239 and U-nat

    Katovsky, K.; Adam, Jindřich; Balabekyan, A.; Pronskikh, V. S.; Solnyshkin, A. A.; Stegailov, V. I.; Tsoupko-Sitnikov, V. M.

    VOL 1. COUTABOEUF: EDP SCIENCES, 2008 - (Bersillon, O.; Gunsing, F.; Bauge, E.; Jacqmin, R.; Leray, S.), s. 1089-1090 ISBN 978-2-7598-0091-9. [International Conference on Nuclear Data for Science and Technology. Nice (FR), 22.04.2007-27.04.2007] R&D Projects: GA MŠk(CZ) 1P04LA213 Institutional research plan: CEZ:AV0Z10480505 Keywords : proton induced reaction * Pu-239 * U-nat * fission Subject RIV: BG - Nuclear, Atomic and Molecular Physics, Colliders

  12. Formation and de-excitation of hot nuclei in reactions induced by proton beams (475 MeV and 2 GeV) and {sup 3}He beam (2 GeV); Formation et desexcitation des noyaux chauds dans les reactions induites par des faisceaux de protons (475 MeV et 2 GeV) et d`{sup 3}He(2 GeV)

    Ledoux, X.

    1995-04-01

    We are studying the formation and the de-excitation of hot nuclei created in reactions induced by light high energy projectiles. These reactions, described in a two step model: an intranuclear cascade followed by an evaporation phase, produce nuclei in which the collective modes (compression, rotation, deformation) are weakly excited. By measuring the neutron multiplicities, event by event with ORION, and the light charged particle energies and multiplicities one can evaluate the excitation energy distribution of the nuclei. At the same time, theoretical simulations are carried out using the intranuclear cascade code developed by J. Cugnon and the statistical de-excitation code GEMINI. The good agreement with experimental results indicate that 10% of the p-nucleus interactions lead to temperatures greater than 5 MeV. The observation of the fission of a nucleus with a temperature close to 5 MeV shows that the nucleus behaves as a set of bound nucleons and, that the temperature stability limit is not yet reached. The observed decline of fission probability at high excitation energies is most likely to be correlated to the appearance of an other de-excitation process (evaporation residues emission or multifragmentation) which could not be experimentally detected. Finally, in the last chapter, we briefly present the principle of transmutation for long-lived nuclear waste with a proton accelerator and underline the interest of the present work in such studies. (author). 54 refs., 80 figs., 13 tabs.

  13. Experimental and theoretical studies of the yields of residual product nuclei produced in thin Pb and Bi targets irradiated by 40 - 2600 MeV protons

    The Project is aimed at experimental determining and computer-aided theoretical simulating the independent and cumulative yields of residual radioactive product nuclei in high-energy protonirradiated thin targets made of high-isotopic and natural lead (206Pb, 207Pb, 208PB, natPb) and bismuth (209Bi) that are the most probable choice to be the target materials in the acceleratordriven (hybrid) systems (ADS) coupled to a high-current proton accelerator. The yields of residual product nuclei are of great importance when estimating such basic radiation-technology characteristics of the hybrid facility targets as the total target activity, the target 'poisoning', the buildup of long-lived nuclides, the α-activity, the content of low-pressure evaporated nuclides (Hg), the content of the chemically-active nuclides that drastically spoil the corrosion resistance of the facility structure materials, etc. In view of the above, the radioactive product nuclide yields from targets materials were experimentally determined using the ITEP U-10 proton accelerator in 55 measurement runs using the monoisotopic and natural lead (206Pb, 207Pb, 208PB, natPb) and bismuth (209Bi) targets within the proton energy range fractionated minutely, namely at 0.04, 0.07, 0.10, 0.8, 1.2, 1.4, 1.6, and 2.6 GeV to cover the entire range of the internuclear hadron cascading. As a result, 5972 cumulative and independent yields of residual radioactive product nuclei, whose lifetimes range from 8 minutes to 32 years, have been measured. Besides, the cross sections for the 27Al(p,x)24Na and 27Al(p,x)7Be monitor reactions have been measured at the same proton energies together with the 27Al(n,p)27Mg reaction rate that characterizes the neutron background contributions in each experiment. The experimental nuclide yields are determined by the direct γ-spectrometry method. The γ-spectrometer resolution is 1.8 keV in the 1332 keV 60Co γ-line. The experimental γ-spectra are processed by the GENIE2000 code

  14. Plans for the German national neutron therapy centre with a hospital-based 70 MeV proton cyclotron at university hospital Essen/Germany

    High-LET hadrons have significant advantages in treatment of special tumour entities. 5 German neutron therapy centres of the seventies are now outdated because of deficiencies in neutron energy (tissue penetration) and technical features. Only the d(14)+Be isocentric neutron therapy facility in Essen is still working. To be comparable with the state-of-the-art in photon therapy Essen is designated to constitute the German National Neutron Therapy Centre based on a p(70)+Be cyclotron delivering neutrons with depth dose distributions comparable to 10 MV X-rays and having multi-leaf collimator and 360 deg rotation. Plans for this centre are presented which use existing installations as far as possible and add the capability for a proton therapy unit for eye tumours. (authors)

  15. Dose-rate influence on the defect production in MeV proton-implanted float-zone and epitaxial n-type silicon

    The production of stable vacancy-related point defects in proton-implanted float-zone and epitaxial silicon has been studied in the low dose range (≤1010/cm2) as a function of dose-rate. The well-known 'inverse dose-rate' effect has been observed in both types of materials with a decrease in the concentration of vacancy-related defects as the dose-rate increases. The effect is less pronounced in oxygen lean epitaxial silicon. Moreover, a continuous decrease of the vacancy-related defect concentration as a function of the flux was measured while a threshold was expected according to previous studies. Both of these results can be explained by a simple calculation, taking into account the influence of the oxygen concentration as well as the influence of the diffusion coefficient of point defects on the 'inverse dose-rate' effect

  16. Fission coincident neutrons from the reactions p + sup(235,236,238)U with protons between 12,7 and 25.5 MeV

    With the proton beam of the Hamburg isochronous cyclotron (HAIZY) thin uranium targets with the mass numbers 235, 236, and 238 were bombarded. Both fragments from the fission of the Np reaction systems and the neutrons coincident with the fragments were detected in the plane perpendicular to the beam direction. Measured and stored event by event were for all particles the times of flight. The detection of the neutron succeeded in conventional time-of-flight technique with NE213 liquid scintillators. A fission detector system with plastic scintillator foils was developed. It permits high event rates over long measuring times and allows the choice of so long neutron flight paths that a neutron energy resolution between 2% and 4% could be reached. The determination of the fragment masses is in spite of the short flight paths of 15 respectively 21 cm possible to +-2 amu. The isotropic component das discussed under the assumption that it is composed of prefission and scission neutrons which were emitted befor fission respectively during the fragmentation. From the post fission results the distribution of the excitation energy to both fragments was determined in dependence of Esup(*) and the fragment mass. (orig./HSI)

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

    The experimental characterization of the neutron fields produced as parasitic effect in medical accelerators is assuming an increased importance for either the patient protection or the facility design aspects. Medical accelerators are diverse in terms of particle type (electrons or hadrons) and energy, but the radiation fields around them have in common (provided that a given threshold energy is reached) the presence of neutrons with energy span over several orders of magnitude. Due to the large variability of neutron energy, field or dosimetry measurements in these workplaces are very complex, and in general, cannot be performed with ready-to-use commercial instruments. In spite of its poor energy resolution, the Bonner Sphere Spectrometer (BSS) is the only instrument able to simultaneously determine all spectral components in such workplaces. The energy range of this instrument is limited to Eo and 90o with respect to the beam-line. Here the ERBSS of UAB (Universidad Autonoma de Barcelona-Grup de Fisica de les Radiacions) and INFN (Istituto Nazionale di Fisica Nucleare-Laboratori Nazionali di Frascati) were exposed to characterize the 'forward' and 'sideward' proton-induced neutron fields. The use of two ERBSS characterized by different set of spheres, central detectors, and independently established and calibrated, is important for guaranteeing the robustness of the measured spectra and estimating their overall uncertainties.

  18. An annealing study of charge collection efficiency on Float-Zone p-on-n ministrip sensors irradiated with 24 GeV/c protons and 20 MeV neutrons

    Float-Zone n-bulk p-readout silicon sensors are currently operated in the tracking layers of many High Energy Physics experiments, where they are exposed to moderate to high fluences of hadrons. Though n-readout sensors, either with p or n bulk, are available and are offering an improved radiation hardness, p-on-n sensors are still widely used and are e.g. installed in the present ATLAS and CMS experiments at CERN. Their radiation hardness and long-term performance are therefore of high interest to the detector community. We present here a study performed on these sensors after irradiation with 24 GeV/c protons and 20 MeV neutrons to fluences ranging from 1⋅1014 to 1⋅1015 neq/cm2. The sensors were then investigated for charge collection efficiency after different isothermal annealing steps in order to understand the performance evolution of the sensor with annealing time. Additional measurements were performed for the highest neutron fluence by means of the Edge-TCT technique, to assess the electric field configuration within the sensor. The irradiation and the annealing scenarios were chosen to represent the radiation damage scenario over the expected lifetime of the LHC detectors (and even further) and to assess the effect of unplanned annealing due to potentially longer warm shutdowns or cooling problems

  19. L1, L2 and L3 subshell ionization cross sections for elements with 71 Z 80 for protons of 0.5 to 3.0 MeV

    We present in this contribution theoretical predictions of the L i (i 1, 2, 3) subshells ionization cross sections within the ECPSSR theory for elements with atomic number 71 Z 80 for protons with energy of 0.5 to 3.0 MeV. These predictions are compared to the experimental data reported by Orlic et al. [At. Data Nucl. Data Tables 56 (1994) 159] and by Sokhi and Crumpton [At. Data Nucl. Data Tables 30 (1984) 49] by plotting the ratio S σ exp/σ ECPSSR as a function of the reduced velocity parameter for each individual subshell L1, L2 and L3. By fitting separately the ratio S, we deduced reference ionization cross sections for each Li subshell. On the other hand, we report empirical ionization cross sections and make a comparison between the reference cross sections, the empirical cross sections reported in this paper and those reported by Sow et al. [Nucl. Instr. and Meth. B 75 (1993) 58] and by Orlic et al. [Int. J. PIXE 4 (4) (1994) 217

  20. Semi-empirical and empirical L X-ray production cross sections for elements with 50 ≤ Z ≤ 92 for protons of 0.5-3.0 MeV

    We present in this contribution, semi-empirical production cross sections of the main X-ray lines Lα, Lβ and Lγ for elements from Sn to U and for protons with energies varying from 0.5 to 3.0 MeV. The theoretical X-ray production cross sections are firstly calculated from the theoretical ionization cross sections of the Li (i = 1, 2, 3) subshell within the ECPSSR theory. The semi-empirical Lα, Lβ and Lγ cross sections are then deduced by fitting the available experimental data normalized to their corresponding theoretical values and give the better representation of the experimental data in some cases. On the other hand, the experimental data are directly fitted to deduce the empirical L X-ray production cross sections. A comparison is made between the semi-empirical cross sections, the empirical cross sections reported in this work and the empirical ones reported by Reis and Jesus [M.A. Reis, A.P. Jesus, Atom. Data Nucl. Data Tables 63 (1996) 1] and those of Strivay and Weber [Strivay, G. Weber, Nucl. Instr. and Meth. B 190 (2002) 112

  1. Parity Violation in Proton-Proton Scattering

    Van Oers, W T H

    1997-01-01

    Measurements of parity-violating longitudinal analyzing powers (normalized asymmetries) in polarized proton-proton scattering provide a unique window on the interplay between the weak and strong interactions between and within hadrons. Several new proton-proton parity violation experiments are presently either being performed or are being prepared for execution in the near future: at TRIUMF at 221 MeV and 450 MeV and at COSY (Kernforschungsanlage Jülich) at 230 MeV and near 1.3 GeV. These experiments are intended to provide stringent constraints on the set of six effective weak meson-nucleon coupling constants, which characterize the weak interaction between hadrons in the energy domain where meson exchange models provide an appropriate description. The 221 MeV is unique in that it selects a single transition amplitude (3P2-1D2) and consequently constrains the weak meson-nucleon coupling constant h_rho{pp}. The TRIUMF 221 MeV proton-proton parity violation experiment is described in some detail. A preliminar...

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

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

    1950-03-06

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

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

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

    1950-03-06

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

  4. Pulsed SC Proton Linac

    Ouchi, N.; Chishiro, E.; Tsukishima, C.; Mukugi, K.

    2000-01-01

    The superconducting (SC) proton linac is proposed in the JAERI/KEK Joint Project for a high-intensity proton accelerator in the energy region from 400 to 600 MeV. Highly stable fields in the SC cavities are required under the dynamic Lorentz force detuning. A new model describing the dynamic Lorentz detuning has been developed and the validity has been confirmed experimentally. The model has been applied successfully to the rf control simulation of the SC proton linac.

  5. Proton beam writing

    Frank Watt; Breese, Mark B H; Bettiol, Andrew A; Jeroen A. van Kan

    2007-01-01

    Proton beam (p-beam) writing is a new direct-writing process that uses a focused beam of MeV protons to pattern resist material at nanodimensions. The process, although similar in many ways to direct writing using electrons, nevertheless offers some interesting and unique advantages. Protons, being more massive, have deeper penetration in materials while maintaining a straight path, enabling p-beam writing to fabricate three-dimensional, high aspect ratio structures with vertical, smooth side...

  6. Dreidimensionale Wasserstoffmikroskopie mittels Proton-Proton-Streuung

    Reichart, Patrick

    2007-01-01

    Mit der Methode der Proton-Proton-Streuung zum Wasserstoffnachweis wurde ein Verfahren entwickelt, um unter Einsatz eines fokussierten 17 MeV Protonenstrahls Wasserstoffverteilungen auf mikroskopischer Skala quantitativ mit einer sub-ppm Nachweisgrenze dreidimensional abzubilden. Die Realisierung am Rasterionenmikroskop SNAKE am Münchener 14 MV Tandembeschleuniger mit einem großen ringförmigen, segmentierten Detektor und einem komplexen Analysesystem ermöglicht eine Nachweisgrenze von 0.08 at...

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

    New data are presented for the 26Mg(p,n)26Al reaction at E/sub p/ = 19.12 and 24.97 MeV, for the 54Fe(p,n)54Co reaction at E/sub p/ = 17.20, 18.60, and 24.60 MeV, and for the 56Fe(p,n)56Co reaction at E/sub p/ = 19.12 and 24.59 MeV. Data were taken with the LLNL Cyclograaff at 16 angles from 3.50 to 159.00. A large detector at 23.80 with a long neutron flight path collected high resolution spectra. This large detector also collected separate 00 high resolution data on the 26Mg and 56Fe(p,n) reactions at E/sub p/ = 19 MeV. Absolute differential (p,n) cross sections were extracted for 1+ states in 26Al, 54Co, and 56Co, for the 0+ isobaric analong state (IAS) in 54Co and 56Co, for a 2+ state in each residual nucleus, and for the 0.199 MeV 7+ state of 54Co. No new experimental states were identified. Only relative cross sections were extracted at 00. Experimental angle-integrated cross sections were obtained for all but one state. DWBA79 was used, with the G-matrix effective nucleon-nucleon interaction of Bertsch et al. (with the central triplet-odd component V/sub to/ = O) and the Livermore shell model wave functions to calculate differential (p,n) cross sections to 1+ states and to the 54Co and 56Co IAS. Normalization of the DWBA angle-integrated cross sections to measurements for the 54Co and 56Co IAS (at E/sub p/ = 24.6 MeV) yielded the renormalized V/sub tau/ = 21.4 +- 2.1 MeV. Normalization of the DWBA angle-integrated cross sections to measurements for the 24.6 MeV 54Co and 56Co 1+ states, coupled with the normalization of the wave functions to previously experimentally determined GT strength, yield the renormalized V/sub sigmatau/ = 12.3 +- 1.2 MeV. The experimental Gamow-Teller strength B(GT)/sub exp./ of the T = 1 26Al state at 9.44 MeV was found to be 0.69; B(GT)/sub exp/ of the T = 1 26Al state at 10.47 MeV was found to be 0.39

  8. Proton radiography to improve proton therapy treatment

    The quality of cancer treatment with protons critically depends on an accurate prediction of the proton stopping powers for the tissues traversed by the protons. Today, treatment planning in proton radiotherapy is based on stopping power calculations from densities of X-ray Computed Tomography (CT) images. This causes systematic uncertainties in the calculated proton range in a patient of typically 3–4%, but can become even 10% in bone regions [1,2,3,4,5,6,7,8]. This may lead to no dose in parts of the tumor and too high dose in healthy tissues [1]. A direct measurement of proton stopping powers with high-energy protons will allow reducing these uncertainties and will improve the quality of the treatment. Several studies have shown that a sufficiently accurate radiograph can be obtained by tracking individual protons traversing a phantom (patient) [4,6,10]. Our studies benefit from the gas-filled time projection chambers based on GridPix technology [2], developed at Nikhef, capable of tracking a single proton. A BaF2 crystal measuring the residual energy of protons was used. Proton radiographs of phantom consisting of different tissue-like materials were measured with a 30×30 mm2 150 MeV proton beam. Measurements were simulated with the Geant4 toolkit.First experimental and simulated energy radiographs are in very good agreement [3]. In this paper we focus on simulation studies of the proton scattering angle as it affects the position resolution of the proton energy loss radiograph. By selecting protons with a small scattering angle, the image quality can be improved significantly

  9. Proton radiography to improve proton therapy treatment

    Takatsu, J.; van der Graaf, E. R.; Van Goethem, M.-J.; van Beuzekom, M.; Klaver, T.; Visser, J.; Brandenburg, S.; Biegun, A. K.

    2016-01-01

    The quality of cancer treatment with protons critically depends on an accurate prediction of the proton stopping powers for the tissues traversed by the protons. Today, treatment planning in proton radiotherapy is based on stopping power calculations from densities of X-ray Computed Tomography (CT) images. This causes systematic uncertainties in the calculated proton range in a patient of typically 3-4%, but can become even 10% in bone regions [1,2,3,4,5,6,7,8]. This may lead to no dose in parts of the tumor and too high dose in healthy tissues [1]. A direct measurement of proton stopping powers with high-energy protons will allow reducing these uncertainties and will improve the quality of the treatment. Several studies have shown that a sufficiently accurate radiograph can be obtained by tracking individual protons traversing a phantom (patient) [4,6,10]. Our studies benefit from the gas-filled time projection chambers based on GridPix technology [2], developed at Nikhef, capable of tracking a single proton. A BaF2 crystal measuring the residual energy of protons was used. Proton radiographs of phantom consisting of different tissue-like materials were measured with a 30×30 mm2 150 MeV proton beam. Measurements were simulated with the Geant4 toolkit.First experimental and simulated energy radiographs are in very good agreement [3]. In this paper we focus on simulation studies of the proton scattering angle as it affects the position resolution of the proton energy loss radiograph. By selecting protons with a small scattering angle, the image quality can be improved significantly.

  10. Study of proton radioactivities

    Davids, C.N.; Back, B.B.; Henderson, D.J. [and others

    1995-08-01

    About a dozen nuclei are currently known to accomplish their radioactive decay by emitting a proton. These nuclei are situated far from the valley of stability, and mark the very limits of existence for proton-rich nuclei: the proton drip line. A new 39-ms proton radioactivity was observed following the bombardment of a {sup 96}Ru target by a beam of 420-MeV {sup 78}Kr. Using the double-sided Si strip detector implantation system at the FMA, a proton group having an energy of 1.05 MeV was observed, correlated with the implantation of ions having mass 167. The subsequent daughter decay was identified as {sup 166}Os by its characteristic alpha decay, and therefore the proton emitter is assigned to the {sup 167}Ir nucleus. Further analysis showed that a second weak proton group from the same nucleus is present, indicating an isomeric state. Two other proton emitters were discovered recently at the FMA: {sup 171}Au and {sup 185}Bi, which is the heaviest known proton radioactivity. The measured decay energies and half-lives will enable the angular momentum of the emitted protons to be determined, thus providing spectroscopic information on nuclei that are beyond the proton drip line. In addition, the decay energy yields the mass of the nucleus, providing a sensitive test of mass models in this extremely proton-rich region of the chart of the nuclides. Additional searches for proton emitters will be conducted in the future, in order to extend our knowledge of the location of the proton drip line.

  11. Proton Beam Energy Characterization

    Marus, Lauren A.; Engle, J.W.; John, K. D.; Birnbaum, E. R.; Nortier, F. M.

    2015-01-01

    Introduction The Los Alamos Isotope Production Facility (IPF) is actively engaged in the development of isotope production technologies that can utilize its 100 MeV proton beam. Characterization of the proton beam energy and current is vital for optimizing isotope production and accurately conducting research at the IPF. Motivation In order to monitor beam intensity during research irradiations, aluminum foils are interspersed in experimental stacks. A theoretical yield of 22Na from...

  12. Proton-proton bremsstrahlung towards the elastic limit

    In oder to study proton-proton bremsstrahlung moving towards the elastic limit, a detection system, consisting of Plastic-ball and SALAD, was set up and an experiment at 190 MeV incident beam energy was performed. Here, the experimental setup and the data analysis procedure along with some results obtained in the measurement are discussed

  13. Proton microanalysis in plants

    Micro-analyses by nuclear reactions and atomic excitation are used to determine the distribution of fluorine and calcium in the needles of Abies Alba. Fluorine is detected by the nuclear reaction 19F(p,α)16O at the 1.35 MeV resonance. Calcium is measured by its characteristic X-rays due to proton excitation

  14. Measurement of proton autoneutralization potential

    A proton space charge having multi-MeV kinetic energy was injected through a thin ground plane to extract electrons and produce a time-dependent autoneutralization space potential. An electon-emitting floating-potential resistive divider was used to measure the space potential during 20 ns of the proton current pulse. During this time, proton kinetic energy fell from 10.6 MeV to 8.5 MeV and thus the space potential (taken as 1.09 x the floating potential) fell from 5.8 kV to 4.6 kV

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

    Lebeda, Ondřej; Lozza, V.; Schrock, P.; Štursa, Jan; Zuber, K.

    2012-01-01

    Roč. 89, č. 4 (2012), 049905/1-049905/12. ISSN 0556-2813 R&D Projects: GA MŠk LA09013 Institutional research plan: CEZ:AV0Z10480505 Keywords : proton-induced reactions * radionuclides Subject RIV: BG - Nuclear, Atomic and Molecular Physics, Colliders Impact factor: 3.715, year: 2012

  16. Spin correlation parameters Axx and Ayy measurements in p-p scattering from 11 to 26 MeV

    The Axx and Ayy spin correlation coefficients of the proton-proton scattering have been measured at the laboratory energies of 11,40 - 19,15 - 23,45 and 26,50 MeV for the center of mass scattering angle 90 degrees. These measurements have been made by scattering a polarized proton beam on a polarized proton target. (authors)

  17. Simultaneous neutron-neutron proton-neutron and proton-proton interferometry measurements

    This paper describes a technique to perform simultaneous neutron-neutron, proton-neutron and proton-proton nuclear interferometry measurements. Experimental arrangements for intermediate energy heavy ion interferometry experiments are presented and their limitations are investigated. The construction of correlation functions, particularly with respect to normalization and background corrections is discussed. Some new results on correlation functions from the reaction 30 A MeV 40Ar+12C are shown and possibilities to improve the interferometry technique are discussed. (orig.)

  18. Proton radiation effect of NPN-input operational amplifier under different bias conditions

    NPN-input bipolar operational amplifiers LM741 were irradiated with 60Co γ-ray, 3 MeV protons and 10 MeV protons respectively at different biases to investigating the proton radiation response of the NPN-input operational amplifier. The comparison of protons with 60Co γ-rays showed that the proton radiation mainly induced ionization damage in LM741. Under different bias conditions, the radiation sensitivity is different; zero biased devices show more radiation sensitivity in the input biased current than forward biased devices. Supply current (±Icc) is another parameter that is sensitive to proton radiation, 60Co γ-ray, 3 MeV and 10 MeV proton irradiation would induce a different irradiation response in ±Icc, which is caused by different ionization energy deposition and displacement energy deposition of 60Co γ-ray, 3 MeV and 10 MeV proton irradiation. (paper)

  19. Study on Beam Steering in the PEFP 20 MeV DTL

    The Proton Engineering Frontier Project (PEFP) is developing a proton linac which accelerate 20 mA proton beams up to 100 MeV. The accelerator consists of an ion source, a low energy beam transport (LEBT), a 3 MeV radio-frequency quadrupole (RFQ), a 100 MeV drift-tube linac (DTL). The DTL structure divides into two parts. One is a DTL (called DTL1) whose energy range is from 3 MeV to 20 MeV. It is designed to operate with 24% beam duty. The other is another DTL (called DTL2) for 20 ∼ 100 MeV with 8% beam duty. There is a MEBT between two DTL structures which will be operated with different beam duties. The main purposes of the MEBT are extracting 20 MeV proton beams to the user group and matching proton beams into the DTL2. This brief report related to the steering properties of the PEFP DTL tanks. For the beam dynamics study related with the steering magnets, we concentrated on the displacement error of the 20 MeV DTL tanks which consists of 4 tanks

  20. Thin-target excitation functions, cross-sections and optimised thick-target yields for natMo(p,xn)94g,95m,95g,96(m+g)Tc nuclear reactions induced by protons from threshold up to 44 MeV. No Carrier Added radiochemical separation and quality control

    This work describes the method adopted in our laboratories, to produce 94gTc, 95gTc, 95mTc and 96gTc radionuclides via proton-cyclotron irradiation on molybdenum targets of natural isotopic composition. A new set of experimental thin-target excitation functions and 'effective' cross-sections for direct natMo(p,xn)ATc [with A=94, 95, 95, 96] nuclear reactions, with incident proton energy in the range from threshold up to 44 MeV is presented. Some definitions of the equations used and nuclear data traceability are reported. Thick-target yield values were calculated and optimised, by numerical fitting and integration of the measured excitation functions. These values allow optimisation of production yield of one radionuclide, minimising at the same time the yield of the others. Radiochemical separation on NCA technetium radionuclides from both molybdenum target and niobium, zirconium and yttrium radioactive by-products is reported. Quality control tests of the radiotracers were developed for the applications envisaged in environmental metallo-biochemical toxicology

  1. Proton Upset Monte Carlo Simulation

    O'Neill, Patrick M.; Kouba, Coy K.; Foster, Charles C.

    2009-01-01

    The Proton Upset Monte Carlo Simulation (PROPSET) program calculates the frequency of on-orbit upsets in computer chips (for given orbits such as Low Earth Orbit, Lunar Orbit, and the like) from proton bombardment based on the results of heavy ion testing alone. The software simulates the bombardment of modern microelectronic components (computer chips) with high-energy (.200 MeV) protons. The nuclear interaction of the proton with the silicon of the chip is modeled and nuclear fragments from this interaction are tracked using Monte Carlo techniques to produce statistically accurate predictions.

  2. Low energy proton induced SEE in memories

    Duzellier, S.; Falguere, D.; Nuns, T.; Guibert, L. [ONERA-CERT/DERTS, Toulouse (France); Ecoffet, R. [CNES, Toulouse (France); Hajdas, W. [Paul Scherrer Inst., Villigen (Switzerland); Calvet, M.C. [Aerospatiale, Les Mureaux (France)

    1997-12-01

    This paper presents proton sensitivity curves obtained on memories from various generations. Highlight is set on components response at very low energy (down to 5MeV) and implications on the calculated SEE rates are discussed.

  3. Proton Therapy

    ... News Physician Resources Professions Site Index A-Z Proton Therapy Proton therapy delivers radiation to tumor tissue ... feel during and after the procedure? What is proton therapy and how is it used? Protons are ...

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

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

    2015-02-01

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

  5. Measurements of 67Ga production cross section induced by protons on natZn in the low energy range from 1.678 to 2.444 MeV

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

  6. Proton irradiation energy dependence of defect formation in graphene

    Lee, Sanggeun; Seo, Jungmok; Hong, Juree [Nanobio Device Laboratory, School of Electrical and Electronic Engineering, Yonsei University, 50 Yonsei-ro, Seodaemun-Gu, Seoul 120-749 (Korea, Republic of); Park, Seul Hyun; Lee, Joo-Hee [Space Science Research Team, Aerospace Convergence Technology Research Laboratory, Korea Aerospace Research Institute, 169-87 Gwahak-ro, Yuseong-Gu, Daejeon 305-806 (Korea, Republic of); Min, Byung-Wook [Microwave Integrated Circuits and Systems Laboratory, School of Electrical and Electronic Engineering, Yonsei University, 50 Yonsei-ro, Seodaemun-Gu, Seoul 120-749 (Korea, Republic of); Lee, Taeyoon, E-mail: taeyoon.lee@yonsei.ac.kr [Nanobio Device Laboratory, School of Electrical and Electronic Engineering, Yonsei University, 50 Yonsei-ro, Seodaemun-Gu, Seoul 120-749 (Korea, Republic of)

    2015-07-30

    Highlights: • We irradiated graphene with 5, 10, and 15 MeV protons at a fixed dose rate of 2 × 10{sup 14} cm{sup −2}. • Different characteristics were observed when irradiated with 5/10 and 15 MeV protons. • More energy is transferred to graphene at lower irradiated proton energy in MeV range. - Abstract: Graphene transistors on SiO{sub 2}/Si were irradiated with 5, 10, and 15 MeV protons at a dose rate of 2 × 10{sup 14} cm{sup −2}. The effect of proton irradiation on the structural defects and electrical characteristics of graphene was measured using Raman spectroscopy and electrical measurements. Raman spectra exhibited high intensity peaks induced by defects after 5 and 10 MeV proton irradiation, whereas no significant defect-induced peaks were observed after 15 MeV proton irradiation. The drain current of graphene transistors decreased and the Dirac point shifted after proton irradiation; however, a flattening in the Dirac point occurred after 15 MeV proton irradiation. The variations in characteristics were attributed to different types of graphene defects, which were closely related to the irradiation energy dependency of the transferred energy. Our observation results were in good agreement with the Bethe formula as well as the stopping and range of ions in matter simulation results.

  7. Medical Proton Accelerator Project

    A project for a medical proton accelerator for cancer treatment is outlined. The project is motivated by the need for a precise modality for cancer curing especially in children. Proton therapy is known by its superior radiation and biological effectiveness as compared to photon or electron therapy. With 26 proton and 3 heavy-ion therapy complexes operating worldwide only one (p) exists in South Africa, and none in south Asia and the Middle East. The accelerator of choice should provide protons with energy 75 MeV for eye treatment and 250 MeV for body treatment. Four treatment rooms are suggested: two with isocentric gantries, one with fixed beams and one for development. Passive scanning is recommended. The project can serve Middle East and North Africa with ∼ 400 million populations. The annual capacity of the project is estimated as 1,100 to be compared with expected radiation cases eligible for proton cancer treatment of not less than 200,000

  8. The proton engineering frontier project: accelerator development

    Since launched in 2002 to establish an advanced research facility to promote and support core R and D programs by utilizing highly-characterized proton beams, the Proton Engineering Frontier Project has been devoted to developing a high-current 100-MeV, 20 mA proton linac. The upstream part of the proton linac, up to 20 MeV, has been successfully developed, integrated, and commissioned and has delivered proton beams to users under a limited operation license. The high-energy part of the accelerator and beamlines are under development. The architectural and radiation shielding design of the accelerator building and beam experimental hall has been completed. The site preparation and construction works are in progress in cooperation with the municipal government of Gyeongju city. When the project is completed in 2012, as scheduled, the proton accelerator facility will be capable of delivering highly-characterized proton beams to multiple users by satisfying their dedicated requirements.

  9. External proton and Li beams

    In the frame of a feasibility study to introduce proton therapy in Argentina in a collaborative agreement between the Physics and Radiobiology Departments of the National Atomic Energy Commission or Argentina and the Centre de Protontherapie de Orsay, France, external proton and Li beams were produced at the TANDAR accelerator in Buenos Aires. The specific aim of this work was to start radiobiology studies on cell cultures and small laboratory animals. In particular we seek to determine here the relative biological effectiveness, RBE, for proton and Li beams as a function of energy for different tumor and normal cell lines. The 24 MeV proton beam was diffused using a 25 μm gold foil and extracted through a Kapton window to obtain a homogeneous field (constant to 95%) of about 7 cm in diameter. Measurements were carried out with quasi-monoenergetic beams (of 20.2 ± 0.07 MeV, 2.9 ± 0.10 MeV y 1.5 ± 0.1 MeV for protons and 21.4 ± 0.4 MeV for Lithium). Proton fluence and Bragg peaks were measured. The dose delivered in each case was monitored on-line with a calibrated transmission ionization chamber. Three cell lines PDV, PDVC 57 and V 79 (as a reference) were irradiated with γ-rays, proton and lithium beams with linear energy transfer (LET) from 2 to 100 keV/μm. RBE values in the range of 1.2-5.9 were obtained. In addition preliminary studies on chromosomal aberrations and viability of alveolar macrophages were carried out. (author)

  10. Neutron cross section standards for energies above 20 MeV at KRI

    Neutron cross sections above 20 MeV are compared to proton cross sections for the same reactions, mainly for uranium-235 and uranium-238 fission. It is noted that between 100 and 1000 MeV these cross sections differ strongly. Other neutron reactions used as standards in KRI for neutron dosimetry are discussed

  11. Proton radiography for clinical applications

    Talamonti, C., E-mail: cinzia.talamonti@unifi.i [Dipartimento di Fisiopatologia Clinica, Universita degli Studi di Firenze, v.le Morgagni 85, I-50134 Firenze (Italy); INFN, sezione di Firenze, via G. Sansone 1, I-50019 Sesto Fiorentino (Italy); Azienda Ospedaliero-Universitaria Careggi, v.le Morgagni 85, I-50134 Firenze (Italy); Reggioli, V. [Dipartimento di Fisiopatologia Clinica, Universita degli Studi di Firenze, v.le Morgagni 85, I-50134 Firenze (Italy); Bruzzi, M. [INFN, sezione di Firenze, via G. Sansone 1, I-50019 Sesto Fiorentino (Italy); Dipartimento di Energetica, Universita degli Studi di Firenze, via S. Marta 3, I-50139 Firenze (Italy); Bucciolini, M. [Dipartimento di Fisiopatologia Clinica, Universita degli Studi di Firenze, v.le Morgagni 85, I-50134 Firenze (Italy); INFN, sezione di Firenze, via G. Sansone 1, I-50019 Sesto Fiorentino (Italy); Azienda Ospedaliero-Universitaria Careggi, v.le Morgagni 85, I-50134 Firenze (Italy); Civinini, C. [INFN, sezione di Firenze, via G. Sansone 1, I-50019 Sesto Fiorentino (Italy); Marrazzo, L. [Azienda Ospedaliero-Universitaria Careggi, v.le Morgagni 85, I-50134 Firenze (Italy); Menichelli, D. [INFN, sezione di Firenze, via G. Sansone 1, I-50019 Sesto Fiorentino (Finland) (Italy); Dipartimento di Energetica, Universita degli Studi di Firenze, via S. Marta 3, I-50139 Firenze (Italy); Pallotta, S. [Dipartimento di Fisiopatologia Clinica, Universita degli Studi di Firenze, v.le Morgagni 85, I-50134 Firenze (Italy); INFN, sezione di Firenze, via G. Sansone 1, I-50019 Sesto Fiorentino (Italy); Azienda Ospedaliero-Universitaria Careggi, v.le Morgagni 85, I-50134 Firenze (Italy); Randazzo, N. [INFN, sezione di Catania, via S. Sofia 64, I-95123 Catania (Italy); Sipala, V. [INFN, sezione di Catania, via S. Sofia 64, I-95123 Catania (Italy); Dipartimento di Fisica, Universita degli Studi di Catania, via S. Sofia 64, I-95123 Catania (Italy)

    2010-01-11

    Proton imaging is not yet applied as a clinical routine, although its advantages have been demonstrated. In the context of quality assurance in proton therapy, proton images can be used to verify the correct positioning of the patient and to control the range of protons. Proton computed tomography (pCT) is a 3D imaging method appropriate for planning and verification of proton radiation treatments, because it allows evaluating the distributions of proton stopping power within the tissues and can be directly utilized when the patient is in the actual treatment position. The aim of the PRoton IMAging experiment, supported by INFN, and the PRIN 2006 project, supported by MIUR, is to realize a proton computed radiography (pCR) prototype for reconstruction of proton images from a single projection in order to validate the technique with pre-clinical studies and, eventually, to conceive the configuration of a complete pCT system. A preliminary experiment performed at the 250 MeV proton synchrotron of Loma Linda University Medical Center (LLUMC) allowed acquisition of experimental data before the completion of PRIMA project's prototype. In this paper, the results of the LLUMC experiment are reported and the reconstruction of proton images of two phantoms is discussed.

  12. Proton radiography for clinical applications

    Proton imaging is not yet applied as a clinical routine, although its advantages have been demonstrated. In the context of quality assurance in proton therapy, proton images can be used to verify the correct positioning of the patient and to control the range of protons. Proton computed tomography (pCT) is a 3D imaging method appropriate for planning and verification of proton radiation treatments, because it allows evaluating the distributions of proton stopping power within the tissues and can be directly utilized when the patient is in the actual treatment position. The aim of the PRoton IMAging experiment, supported by INFN, and the PRIN 2006 project, supported by MIUR, is to realize a proton computed radiography (pCR) prototype for reconstruction of proton images from a single projection in order to validate the technique with pre-clinical studies and, eventually, to conceive the configuration of a complete pCT system. A preliminary experiment performed at the 250 MeV proton synchrotron of Loma Linda University Medical Center (LLUMC) allowed acquisition of experimental data before the completion of PRIMA project's prototype. In this paper, the results of the LLUMC experiment are reported and the reconstruction of proton images of two phantoms is discussed.

  13. The disintegration of nuclei in violent heavy ion interactions at 55 A MeV-110 A MeV

    High multiplicity 12C induced reactions in Ag(Br) at energies between 55 A MeV and 110 A MeV have been selected and investigated event by event in nuclear emulsions. Only a fraction of these events can possibly be described in terms of a normal thermal spectator-participant mechanism. Several events exhibit a violent breakup into several light and medium-mass fragments. A strong suppression of projectile associated proton- and composite particle emission in the forward direction is found in comparison with inclusive spectra. A large part of the low energy protons originates from a very slow source, with a velocity comparable to that of the heaviest fragment. The parallel fraction of the C.m. energy in each event, which is governed by the more energetic protons, has a broad distribution with a mean value of 0.61 and thus with no signals of collective production mechanisms. (orig.)

  14. Cross-sections for nuclide production in 56Fe target irradiated by 300, 500,750, 1000, 1500, and 2600 MeV protons compared with data on hydrogen target irradiation by 300, 500, 750, 1000, and 1500 MeV/nucleon 56Fe ions

    Titarenko, Yu E; Titarenko, A Yu; Butko, M A; Pavlov, K V; Florya, S N; Tikhonov, R S; Mashnik, S G; Ignatyuk, A V; Titarenko, N N; Gudowsky, W; Tesinsky, M; Persson, C -M L; Abderrahim, H Ait; Kumawat, H; Duarte, H

    2008-01-01

    Cross-sections for radioactive nuclide production in 56Fe(p,x) reactions at 300, 500, 750, 1000, 1500, and 2600 MeV were measured using the ITEP U-10 proton accelerator. In total, 221 independent and cumulative yields of products of half-lives from 6.6 min to 312 days have been obtained via the direct-spectrometry method. The measured data have been compared with the experimental data obtained elsewhere by the direct and inverse kinematics methods and with calculations by 15 codes, namely: MCNPX (INCL, CEM2k, BERTINI, ISABEL), LAHET (BERTINI, ISABEL), CEM03 (.01, .G1, .S1), LAQGSM03 (.01, .G1, >.S1), CASCADE-2004, LAHETO, and BRIEFF. Most of our data are in a good agreement with the inverse kinematics results and disprove the results of some earlier activation measurements that were quite different from the inverse kinematics measurements. The most significant calculation-to-experiment differences are observed in the yields of the A<30 light nuclei, indicating that further improvements in nuclear reaction ...

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

    Wang, H. T.

    1973-01-01

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

  16. Vacancy-type defects in electron and proton irradiated ZnS and ZnTe

    In this contribution we present a study aimed at investigating irradiation induced defects in ZnTe single crystals (3 MeV protons), ZnS single crystals (1 MeV electrons) and ZnS polycrystals (3 MeV protons). In positron annihilation experiments the stability of the induced defects as well as possible clustering mechanisms were investigated. It was found that both electron and proton irradiation caused significant changes in the positron annihilation characteristics. (orig.)

  17. Opening of proton beam therapy in Japan

    Just after completion of the 12-GeV proton synchrotron complex at KEK in 1976, medical use of rapid-cycling 500-MeV Booster beams were investigated. Prof. Herman Suit of Harvard University recommended proton beam therapy, and soon it became clear that it was most suitable for Tsukuba. University of Tsukuba built and operated a medical research center with support of KEK. It included three activities, fast neutron therapy, proton radiography and proton therapy. It was showed clinically that the proton beam therapy is effective for deep-seated tumors such as hepatoma. (author)

  18. Compact proton spectrometers for measurements of shock

    Mackinnon, A; Zylstra, A; Frenje, J A; Seguin, F H; Rosenberg, M J; Rinderknecht, H G; Johnson, M G; Casey, D T; Sinenian, N; Manuel, M; Waugh, C J; Sio, H W; Li, C K; Petrasso, R D; Friedrich, S; Knittel, K; Bionta, R; McKernan, M; Callahan, D; Collins, G; Dewald, E; Doeppner, T; Edwards, M J; Glenzer, S H; Hicks, D; Landen, O L; London, R; Meezan, N B

    2012-05-02

    The compact Wedge Range Filter (WRF) proton spectrometer was developed for OMEGA and transferred to the National Ignition Facility (NIF) as a National Ignition Campaign (NIC) diagnostic. The WRF measures the spectrum of protons from D-{sup 3}He reactions in tuning-campaign implosions containing D and {sup 3}He gas; in this work we report on the first proton spectroscopy measurement on the NIF using WRFs. The energy downshift of the 14.7-MeV proton is directly related to the total {rho}R through the plasma stopping power. Additionally, the shock proton yield is measured, which is a metric of the final merged shock strength.

  19. Proton-proton bremsstrahlung

    The use is emphasised of the ppγ process as laboratory to study among others, relativistic effects and role of non-nucleonic degrees of freedom below the pion threshold. The process of bremsstrahlung, in particular pp-bremsstrahlung, forms a very sensitive probe to effects which are often ignored because they are difficult to calculate and are estimated to be small. The proton-proton bremsstrahlung (ppγ) process is unique since it is the simplest process where one is sensitive to the off-shell nucleon-nucleon T-matrix, the role of the Δ-isobar in nuclear Compton scattering and other

  20. 3 MeV Test Stand commissioning report

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

    2013-01-01

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

  1. Simulations of proton beam characteristics for ELIMED Beamline

    Psikal, Jan; Limpouch, Jiri; Klimo, Ondrej; Vyskocil, Jiri; Margarone, Daniele; Korn, Georg

    2016-03-01

    ELIMED Beamline should demonstrate the capability of laser-based particle accelerators for medical applications, mainly for proton radiotherapy of tumours which requires a sufficient number of accelerated protons with energy about 60 MeV at least. In this contribution, we study the acceleration of protons by laser pulse with parameters accessible for ELIMED Beamline (intensity ∼ 1022 W/cm2, pulse length ∼ 30 fs). In our two-dimensional particle-incell simulations, we observed higher energies of protons for linear than for circular polarization. Oblique incidence of the laser pulse on target does not seem to be favourable for proton acceleration at such high intensities as the accelerated protons are deflected from target normal axis and their energy and numbers are slightly decreased. The expected numbers of accelerated protons in the energy interval 60 MeV ± 5% are calculated between 109 and 1010 per laser shot with estimated proton beam divergence about 20° (FWHM).

  2. Compton Scattering by the Proton

    Galler, G; Kondratev, R; Massone, A M; Wolf, S; Ahrens, J; Arends, H J; Beck, R; Camen, M; Capitani, G P; Grabmayr, P; Hall, S J; Härter, F; Hehl, T; Jennewein, P; Kossert, K; Lvov, A I; Molinari, C; Ottonello, P; Peise, J; Preobrajenskij, I; Proff, S; Robbiano, A; Sanzone, M; Schumacher, M; Schmitz, M; Wissmann, F

    2001-01-01

    Compton scattering by the proton has been measured over a wide range covering photon energies 250 MeV < E_\\gamma < 800 MeV and photon scattering angles 30^0 < \\theta^{lab}_\\gamma < 150^0, using the tagged-photon facility at MAMI (Mainz) and the large-acceptance arrangement LARA. The data are in good agreement with the dispersion theory based on the SAID-SM99K parameterization of photo-meson amplitudes. From the subset of data between 280 and 360 MeV the resonance pion-photoproduction amplitudes were evaluated leading to the multipole E2/M1 ratio EMR(340 MeV) =(-1.6 \\pm 0.4(stat+syst) \\pm 0.2(model)%. From all data below 455 MeV the proton's backward spin polarizability was determined to be \\gamma_\\pi=(-37.9 \\pm 0.6(stat+syst) \\pm 3.5(model))x10^{-4}fm^4.

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

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

    1997-01-01

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

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

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

  5. ACCELERATING POLARIZED PROTONS TO HIGH ENERGY.

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

    2006-10-02

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

  6. Nuclear interaction cross sections for proton radiotherapy

    Chadwick, M B; Arendse, G J; Cowley, A A; Richter, W A; Lawrie, J J; Newman, R T; Pilcher, J V; Smit, F D; Steyn, G F; Koen, J W; Stander, J A

    1999-01-01

    Model calculations of proton-induced nuclear reaction cross sections are described for biologically-important targets. Measurements made at the National Accelerator Centre are presented for double-differential proton, deuteron, triton, helium-3 and alpha particle spectra, for 150 and 200 MeV protons incident on C, N, and O. These data are needed for Monte Carlo simulations of radiation transport and absorbed dose in proton therapy. Data relevant to the use of positron emission tomography to locate the Bragg peak are also described.

  7. Output beam energy measurement of a 100-MeV KOMAC drift tube linac by using a stripline beam position monitor

    Kim, Han-Sung

    2015-10-01

    The 100-MeV proton linac at the KOMAC (Korea Multi-purpose Accelerator Complex) is composed of a 50-keV proton injector, a 3-MeV RFQ (radio-frequency quadrupole) and a 100-MeV DTL (drift tube linac). The proton beam is accelerated from 3 MeV to 100 MeV through 11 DTL tanks. The precise measurement of the proton-beam's energy at the output of each DTL tank is important for the longitudinal beam dynamics and can be performed by using a time-of-flight method with a BPM (beam position monitor), which is installed between each DTL tank. The details of the output beam energy measurement of the KOMAC DTL with stripline-type BPM and BPM signal processing, along with a comparison with the simulation results, will be presented in this paper.

  8. Intermediate energy proton scattering from 10B

    Differential cross sections have been measured for 200 MeV proton scattering from 10B. Data for six low lying natural parity levels below 6 MeV excitation energy are presented. Distorted wave analysis using a density dependent nucleon-nucleon interaction has assessed model spectroscopies of these excited states. The significance of the contribution from quadrupole scattering to the elastic cross section is discussed. 49 refs., 5 tabs., 21 figs

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

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

    1996-10-01

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

  10. Proton Decay

    Raby, Stuart

    2002-01-01

    We discuss the status of supersymmetric grand unified theories [SUSY GUTs] with regards to the observation of proton decay. In this talk we focus on SUSY GUTs in 4 dimensions. We outline the major theoretical uncertainties present in the calculation of the proton lifetime and then present our best estimate of an absolute upper bound on the predicted proton lifetime. Towards the end, we consider some new results in higher dimensional GUTs and the ramifications for proton decay.

  11. Properties of defects in Cu(In,Ga)Se sub 2 after electron and proton irradiation

    Jasenek, A

    2002-01-01

    A model developed in this thesis describes the degradation of CIGS solar cells after irradiation. The measurement of the admittance and the capacitance transient of the irradiated CIGS solar cells identifies the defect generated by 1-MeV electron irradiation as acceptor with an activation energy of 300 meV meV above the valence band edge in CIGS. The results of the irradiation with 4- and 10-MeV protons as well as with 0.5-, 1-, and 3-MeV electrons allow the prediction of the degradation of CIGS solar cells by irradiation with arbitrary-energy electrons and protons.

  12. Cross sections in the energy range from 10 to 40 MeV calculated with the GNASH code. [GNASA, below 40 MeV

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

    1977-01-01

    A brief description of the preequilibrium-statistical model code GNASH is given. Features which make the code applicable to the calculation of cross sections induced by nucleons of energy 40 MeV or less are described. Finally, examples of calculations of neutron- and proton-induced reaction cross sections, activation cross sections, and secondary spectra made with global input parameters are given.

  13. Active interrogation using energetic protons

    Morris, Christopher L [Los Alamos National Laboratory; Chung, Kiwhan [Los Alamos National Laboratory; Greene, Steven J [Los Alamos National Laboratory; Hogan, Gary E [Los Alamos National Laboratory; Makela, Mark [Los Alamos National Laboratory; Mariam, Fesseha [Los Alamos National Laboratory; Milner, Edward C [Los Alamos National Laboratory; Murray, Matthew [Los Alamos National Laboratory; Saunders, Alexander [Los Alamos National Laboratory; Spaulding, Randy [Los Alamos National Laboratory; Wang, Zhehui [Los Alamos National Laboratory; Waters, Laurie [Los Alamos National Laboratory; Wysocki, Frederick [Los Alamos National Laboratory

    2010-01-01

    Energetic proton beams provide an attractive alternative when compared to electromagnetic and neutron beams for active interrogation of nuclear threats because they have large fission cross sections, long mean free paths and high penetration, and they can be manipulated with magnetic optics. We have measured time-dependent cross sections and neutron yields for delayed neutrons and gamma rays using 800 MeV and 4 GeV proton beams with a set of bare and shielded targets. The results show significant signals from both unshielded and shielded nuclear materials. Measurements of neutron energies yield suggest a signature unique to fissile material. Results are presented in this paper.

  14. General layout of the 17 MeV injector for MYRRHA

    Podlech, Holger; Amberg, Michael; Klein, Horst; Mäder, Dominik; Busch, Marco; Ratzinger, Ulrich; Schempp, Alwin; Tiede, Rudolf; Vossberg, Markus; Zhang, Chuansheng

    2011-01-01

    The MYRRHA Project (Multi Purpose Hybrid Reactor for High Tech Applications) at Mol/belgium will be a user facility with emphasis on research with neutron generated by a spallation source. One main aspect is the demonstration of nuclear waste technology using an accelerator driven system. A superconducting linac delivers a 4 mA, 600 MeV proton beam. The first accelerating section is covered by the 17 MeV injector. It consists of a proton source, an RFQ, two room temperature CH cavities and 4 ...

  15. Proton therapy

    Proton therapy has become a subject of considerable interest in the radiation oncology community and it is expected that there will be a substantial growth in proton treatment facilities during the next decade. I was asked to write a historical review of proton therapy based on my personal experiences, which have all occurred in the United States, so therefore I have a somewhat parochial point of view. Space requirements did not permit me to mention all of the existing proton therapy facilities or the names of all of those who have contributed to proton therapy. (review)

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

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

  17. Elastic scattering of polarised deuterons from 16O at 200, 400 and 700 MeV

    Angular distributions of cross section, and Ay and Ayy analysing powers were measured for polarised deuteron elastic scattering from 16O at 200, 400 and 700 MeV. The data at 200 MeV bear evidence of the nuclear rainbow phenomenon while those at 400 and 700 MeV are reminiscent of the proton scattering results at equivalent energies. The data were analysed in terms of the optical model. The real central potential shape changes from an attractive Woods-Saxon form at 200 MeV to a wine-bottle-bottom form with a repulsive interior at 700 MeV. The total reaction cross sections deduced display a clear nuclear transparency effect in the present energy domain in agreement with predictions from the Glauber theory optical limit. Comparison with previous results for 40Ca and 58Ni targets is made. (orig.)

  18. Elastic scattering of polarised deuterons from 16O at 200, 400 and 700 MeV

    Angular distributions of cross section, and Ay and Ayy analysing powers were measured for polarised deuteron elastic scattering from 16O at 200, 400 and 700 MeV. The data at 200 MeV bear evidence of the nuclear rainbow phenomenon while those at 400 and 700 MeV are reminiscent of the proton scattering results at equivalent energies. The data were analysed in terms of the optical model. The real central potential shape changes from an attractive Woods-Saxon form at 200 MeV to a wine-bottle-bottom form with a repulsive interior at 700 Mev. The total reaction cross sections deduced display a clear nuclear transparency effect in the present energy domain agreement with predictions from the Glauber theory optical limit. Comparison with previous results for 40Ca and 58Ni targets is made

  19. 50 MeV polarimeter

    A description is given of the construction, operation and calibration of the 50 MeV polarimeter which was used at the ZGS. The dependence of the observed counts on various parameters, including the beam polarization, beam intensity and the solid angle in the two polarimeter arms is also discussed

  20. The PRIMA (PRoton IMAging) collaboration: Development of a proton Computed Tomography apparatus

    Scaringella, M., E-mail: scaringella@gmail.com [Dipartimento di Ingegneria Industriale, Università di Firenze, Firenze (Italy); Brianzi, M. [INFN—Sezione di Firenze, Firenze (Italy); Bruzzi, M. [INFN—Sezione di Firenze, Firenze (Italy); Dipartimento di Fisica e Astronomia, Università di Firenze, Firenze (Italy); Bucciolini, M. [INFN—Sezione di Firenze, Firenze (Italy); Dipartimento di Scienze biomediche, sperimentali e cliniche, Università di Firenze, Firenze (Italy); SOD Fisica Medica, Azienda Ospedaliero-Universitaria Careggi, Firenze (Italy); Carpinelli, M. [Dipartimento di Chimica e Farmacia, Università di Sassari, Sassari (Italy); INFN sezione di Cagliari, Cagliari (Italy); Cirrone, G.A.P. [INFN—Laboratori Nazionali del Sud, Catania (Italy); Civinini, C. [INFN—Sezione di Firenze, Firenze (Italy); Cuttone, G. [INFN—Laboratori Nazionali del Sud, Catania (Italy); Lo Presti, D. [INFN—Sezione di Catania, Catania (Italy); Dipartimento di Fisica, Università di Catania, Catania (Italy); Pallotta, S. [INFN—Sezione di Firenze, Firenze (Italy); Dipartimento di Scienze biomediche, sperimentali e cliniche, Università di Firenze, Firenze (Italy); SOD Fisica Medica, Azienda Ospedaliero-Universitaria Careggi, Firenze (Italy); Pugliatti, C. [INFN—Sezione di Catania, Catania (Italy); Dipartimento di Fisica, Università di Catania, Catania (Italy); Randazzo, N. [INFN—Sezione di Catania, Catania (Italy); Romano, F. [Centro Studi e Ricerche e Museo Storico della Fisica, Rome (Italy); Sipala, V. [Dipartimento di Chimica e Farmacia, Università di Sassari, Sassari (Italy); INFN sezione di Cagliari, Cagliari (Italy); and others

    2013-12-01

    This paper describes the development of a proton Computed Tomography (pCT) apparatus able to reconstruct a map of stopping power useful for accurate proton therapy treatment planning and patient positioning. This system is based on two main components: a silicon microstrip tracker and a YAG:Ce crystal calorimeter. Each proton trajectory is sampled by the tracker in four points: two upstream and two downstream the object under test; the particle residual energy is measured by the calorimeter. The apparatus is described in details together with a discussion on the characterization of the hardware under proton beams with energies up to 175 MeV.