Nuclide production cross sections from irradiation of thorium by 438 MeV protons and a comparison to fluka and geant4 simulations

Abstract

Thorium targets were irradiated with 438-MeV protons, resulting in spallation and high-energy fission reactions. The measured production cross sections of 38 nuclides in the mass range 83 to 233 are reported. These cross-section data are useful for validating nuclear interaction models and are compared to simulated cross sections calculated using three different Monte Carlo packages, fluka (version 2011.2x.7), geant4 (version 10.6, with the Liege intranuclear cascade model and the abla version 3.1 evaporation code), and geant4 (version 10.6, with the binary cascade model). These data are also useful for estimating radionuclide production yields following an irradiation, in particular for the production of $^{225}\mathrm{Ac}$, a radionuclide of currently heightened interest in nuclear medicine for the treatment of cancer. For most nuclides reported, the measured, literature, and simulated cross-section values agree within a factor of 2.