Some neutronic calculations for KENS-II

Proton energies of the intense spallation neutron sources currently in operation or designed are in the range Ep ≤ 1.1 GeV. Optimization studies of the target station have so far been performed for these proton energies. The KENS-II project has been included in the Japanese Hadron Facility Project where we have to share the proton accelerator, a so-called ''First Ring'', with Meson Arena for nuclear physics and μSR experiments. The possible highest proton energy for this accelerator is 2 GeV, which is the highest among the world's spallation neutron sources. We, therefore, performed some neutronic calculations with 2 GeV protons in order to have a good knowledge of the neutronic characteristics and the optimal parameters of the target station for KENS-II. First we considered cylindrical targets and then rectangular parallel piped targets. The target was a uniform mixture of target metal with coolant and cladding, which was similar to the model target used in the optimization study of ISIS. Source neutrons below 15 MeV produced in a target were calculated using the NMTC/JAERI code. Leakage neutrons from a bare target and slow neutrons emitted from a moderator were calculated using the TOWTRAN-II and MORSE-DD codes, respectively, coupled with the NMTC/JAERI code. (author)