Benchmark calculation of the PHITS code for neutron attenuation in iron and concrete on shielding experiments at proton accelerator facilities

陽子加速器施設における遮蔽実験に基づく鉄及びコンクリート中の中性子減弱に関するPHITSのベンチマーク計算

松田 規宏  ; 岩元 洋介   ; 佐藤 達彦   ; 橋本 慎太郎  ; 小川 達彦   ; 古田 琢哉   ; 安部 晋一郎   ; 甲斐 健師   ; 細山田 龍二*; 岩瀬 広*; 中島 宏; 仁井田 浩二*

Matsuda, Norihiro; Iwamoto, Yosuke; Sato, Tatsuhiko; Hashimoto, Shintaro; Ogawa, Tatsuhiko; Furuta, Takuya; Abe, Shinichiro; Kai, Takeshi; Hosoyamada, Ryuji*; Iwase, Hiroshi*; Nakashima, Hiroshi; Niita, Koji*

Recently, PHITS (Particle and Heavy Ion Transport code System) was revised with respect to its intra-nuclear cascade models and the neutron cross section library. In order to validate the accuracy, benchmark calculations were carried out. With regard to the neutron attenuation in iron and concrete, experimental results were selected for this benchmark calculation. Monoenergetic neutrons of 68 and 138 MeV, and spallation neutrons by 2.83-GeV proton were used as a source. The calculated results both in iron and concrete by the PHITS code were in good agreement with the experimental results on the whole, while some overestimations about 2 times were observed in the result at 100-cm-thick iron, and at 100- and 150-cm-thick concrete for the 68 MeV neutron experiment. Only for the 68-MeV experiment, neutron attenuation in iron of the PHITS calculation tended to be larger than the measured one. On the other hand, neutron attenuation in concrete showed an opposite trend.