Thick-target Neutron And. Gamma.-ray Yields Induced by Medium-energy Proton and Deuteron Bombardments

Thick-target Neutron And. Gamma.-ray Yields Induced by Medium-energy Proton and Deuteron Bombardments

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Published: 1979

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Stopping samples of Lucite, Al, Fe, and 238U (Fe, and 238U) were irradiated with 330 MeV deuterons (260 MeV protons). For each target, neutron energy spectra and prompt .gamma.-ray yields were measured using the time-of-flight technique. The detector was a right cylindrical volume of deuterated benzene, 12.5-cm diameter x 7.5-cm long, located at 110° to the incident beam direction. The neutron yield and the prompt .gamma.-ray yield were found to depend upon the atomic number of the target and upon the incident projectile. The measured shape of the neutron energy spectrum was not strongly dependent on either the incident projectile or the target atomic number. A lower limit for absolute neutron yields was also obtained.


Calculated Proton-induced Thick-target Neutron and Radionuclide Yields for E/sub P/ D"100 MeV.

Calculated Proton-induced Thick-target Neutron and Radionuclide Yields for E/sub P/ D

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Published: 1989

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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.


Calculated Proton-induced Thick-target Radionuclide Activation Yields and Neutron Yield Spectra for E

Calculated Proton-induced Thick-target Radionuclide Activation Yields and Neutron Yield Spectra for E

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Published: 1988

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Radionuclide production cross sections have been calculated with the GNASH code for protons below 50 MeV incident of on the stable nuclides of a range of elements common to accelerator materials. These elements include C, O, Ne, Al, Si, Fe, Co, Ni, Cu, and W. These data, augmented with limited measured data, have been used with the proton stopping cross-section data of Anderson and Ziegler to calculate thick-target yield values for the formation of a range of radionuclides in accelerator materials. Illustrative results are presented. GNASH calculations have also been made on a grid of proton energies below 50 MeV to produce differential cross sections describing angle-integrated neutron production spectra. The angular distribution systematics of Kalbach and Mann have been used to produce double-differential cross-section, which were used with the proton stopping data to produce anisotropic thick-target neutron yield spectra. Results are presented for 52-MeV protons on a thick target of Cu. Comparisons are made with results of HETC calculations, using cross sections from the intranuclear cascade plus evaporation model, and with thick-target neutron yield spectra measured by Nakamura, Fijii, and Shin. 15 refs., 3 figs., 1 tab.


Thick-target Neutron, Gamma-ray, and Radionuclide Production for Protons Below 12 MeV on Nickel and Carbon Beam-stops

Thick-target Neutron, Gamma-ray, and Radionuclide Production for Protons Below 12 MeV on Nickel and Carbon Beam-stops

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Published: 1998

Total Pages: 11

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Nuclear model calculations using the GNASH code are described for protons below 12 MeV incident on nickel and carbon isotopes, for beam stop design in the Los Alamos Accelerator Production of Tritium Low Energy Demonstration Accelerator (LEDA) project. The GNASH calculations apply Hauser-Feshbach and preequilibrium reaction theories and can make use of pre-calculated direct reaction cross sections to low-lying residual nucleus states. From calculated thin target cross sections, thick target 6.7 MeV and 12 MeV proton-induced production of neutrons, gamma rays, and radionuclides are determined. Emission spectra of the secondary neutrons and gamma rays are also determined. The model calculations are validated through comparisons with experimental thin- and thick-target measurements. The results of this work are being utilized as source terms in MCNP analyses for LEDA.