Recent improvements of the Particle and Heavy Ion Transport code System; PHITS version 3.33

Sato, Tatsuhiko   ; Iwamoto, Yosuke   ; Hashimoto, Shintaro  ; Ogawa, Tatsuhiko   ; Furuta, Takuya   ; Abe, Shinichiro   ; Kai, Takeshi   ; Matsuya, Yusuke  ; Matsuda, Norihiro  ; Hirata, Yuho   ; Sekikawa, Takuya; Yao, L.; Tsai, P.-E.*; Ratliff, H. N.*; Iwase, Hiroshi*; Sakaki, Yasuhito*; Sugihara, Kenta*; Shigyo, Nobuhiro*; Sihver, L.*; Niita, Koji*

The Particle and Heavy Ion Transport code System (PHITS) is a general-purpose Monte Carlo radiation transport code that can simulate the behavior of most particle species with energies up to 1 TeV (per nucleon for ions). Its new version, PHITS3.31, was recently developed and released to the public. In the new version, the compatibility with high-energy nuclear data libraries and the algorithm of the track-structure modes have been improved. In this paper, we summarize the upgraded features of PHITS3.31 with respect to the physics models, utility functions, and application software introduced since the release of PHITS3.02 in 2017.