Development of nuclear de-excitation model EBITEM Ver.2

Ogawa, Tatsuhiko   ; Hashimoto, Shintaro  ; Sato, Tatsuhiko   

The gamma de-excitation model of the general-purpose radiation transport code Particle and Heavy Ion Transport code System (PHITS), called the Evaluated Nuclear Structure Data File (ENSDF-)-Based Isomeric Transition and isomEr production Model (EBITEM) has been upgraded with focus on precise neutron capture reaction simulation. The first de-excitation subsequent to neutron capture of numerous nuclei, which was formerly simulated by a model based on the single particle model, is calculated using the Evaluated Gamma Activation File (EGAF). The database used for further de-excitation, ENSDF, retrieved in 2013, was replaced with Reference Input Parameter Library 3 (RIPL-3) to consider internal conversion. The internal conversion process was interfaced with the atomic de-excitation model to assess the emission of Auger electrons and fluorescent X-rays. The spectra of gamma-rays from neutron capture reactions calculated by the upgraded EBITEM correlate better with the evaluated cross section data than those of the previous version.