Analysis of neutronic experiment on a simulated mercury spallation neutron target assembly bombarded by Giga-electron-Volt protons

Maekawa, Fujio  ; Meigo, Shinichiro   ; Kasugai, Yoshimi  ; Takada, Hiroshi   ; Ino, Takashi*; Sato, Setsuo*; Jerde, E.*; Glasgow, D.*; Niita, Koji*; Nakashima, Hiroshi; Oyama, Yukio; Ikeda, Yujiro; Watanabe, Noboru; Hastings, J.*; ASTE Collaboration Team

A neutronic benchmark experiment on a simulated spallation neutron target assembly with 1.94, 12 and 24 GeV proton beams conducted by using the AGS accelerator at BNL/US was analyzed to investigate validity of neutronics calculations on proton accelerator driven spallation neutron sources. Monte Carlo particle transport calculation codes NMTC/JAM, MCNPX and MCNP-4A with associated cross section data in JENDL and LA-150 were used for the analysis. As a result, although the overall energy range was encompassed from GeV to meV, i.e., more than 12 orders of magnitude, calculated fast and thermal neutron fluxes agreed approximately within 40 % with the experiments. Accordingly, it was concluded that neutronics calculations with these codes and cross section data were adequate for estimating nuclear properties in spallation neutron sources.