Application of new nuclear de-excitation model of PHITS for prediction of isomer yield and prompt -ray production

Ogawa, Tatsuhiko   ; Hashimoto, Shintaro  ; Sato, Tatsuhiko   ; Niita, Koji*

A new de-excitation model, EBITEM (ENSDF-Based Isomeric Transition/ isomEr production Model), intended for simulation of isomeric transition of excited nuclei was incorporated to PHITS and applied for de-excitation of nuclear reaction products. The energy spectra of the prompt -rays and isomer production in various reactions were simulated by PHITS-EBITEM and compared with literature data. The isomeric to ground ratios and prompt -ray spectra from neutron capture reaction products agreed with literature data generally within a few 10%. PHITS-EBITEM was also applied to spallation reaction products and isomeric to ground ratios were reproduced within a factor of three. PHITS-EBITEM is useful for accurate simulation of detector performance, radiation shielding and radioactive inventory including isomers.