Validation of PHITS spallation models from the perspective of the shielding design of transmutation experimental facility

岩元 大樹; 明午 伸一郎

EPJ Web of Conferences, 153, p.01016_1 - 01016_9, 2017/09

https://doi.org/10.1051/epjconf/201715301016

The impact of different spallation models implemented in the particle transport code PHITS on the shielding design of Transmutation Experimental Facility (TEF) was investigated. For 400-MeV proton incident on a lead-bismuth eutectic target. An effective dose rate at the end of a thick radiation shield (3-m-thick iron and 3-m-thick concrete) calculated by the Lige intranuclear cascade (INC) model version 4.6 (INCL4.6) coupled with the GEM code (INCL4.6/GEM) yields 1.5 times higher than the Bertini INC model (Bertini/GEM). A comparison with experimental data for 500-MeV proton incident on a thick lead target shows that the INCL4.6/GEM is in fairly good agreement with the experiment, which suggest that the prediction accuracy of INCL4.6/GEM would be better than that of Bertini/GEM. In contrast, it is found that the dose rates in beam ducts in front of targets calculated by the INCL4.6/GEM are lower than those by the Bertini/GEM. Since both models underestimate the experimental results for neutron-production double-differential cross sections at 180 for 140-MeV proton incident on carbon, iron, and gold targets, we conclude that it is necessary to allow for a margin of uncertainty caused by the spallation models, which is a factor of two, in estimating the dose rate induced by neutron streaming through a beam duct.