Neutron Production in Semiprototypic Target Assemblies for Accelerator Transmutation Technology

Integral neutron production was measured by the manganese-activation technique, on targets semiprototypic of spallation-neutron-driven transmutation systems, after irradiation by 400-MeV to 2.0-GeV protons. The purpose of these experiments was to provide data to benchmark nuclear transport codes for targets irradiated by protons in this energy range, as well as to evaluate design options to maximize the production of spallation neutrons in various targets under consideration. These computer codes are used to design accelerator systems that will utilize spallation neutrons for the generation of tritium, transmutation of nuclear waste, production of radioisotopes, and other scientific investigations. Some of the targets used in this investigation were semiprototypic of the proposed Accelerator Production of Tritium target. Other targets were included to provide data to test the computational models in the codes. Total neutron production is the main factor that determines the economics of transmutation for a particular accelerator design. Comparisons of the data reported here with calculations from computer simulations show agreement to within 15% over the entire energy region for most of the targets.