CALCULATED PROTON-INDUCED THICK-TARGET RADIONUCLIDE ACTIVATION YIELDS AND NEUTRON YIELD SPECTRA FOR Ep ≤ 50 MeV, WITH COMPARISONS TO OTHER CALCULATIONS AND MEASURED DATA
Los Alamos National Laboratory, Los Alamos, New Mexico, 87545 USA
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, Fujii, and Shin.
KEYWORDS: accelerators, medium-energy protons, proton activation, thick-target neutron yields