Photonuclear reaction cross-section evaluation of Ta and Bi considering experimental double differential cross-section data

二重微分断面積測定データを考慮したTaとBiの光核反応断面積評価

Nguyen, T. T. H.*; 岩本 信之  ; 佐波 俊哉*

Nguyen, T. T. H.*; Iwamoto, Nobuyuki; Sanami, Toshiya*

The double differential cross-sections (DDXs) on the medium and heavy targets have been measured using monoenergetic, polarized 13 and 17 MeV photon beams. Therefore, it is desired that the DDX data be included in the evaluation process of the nuclear data library. We have been implementing this evaluation on Ta and Bi. These nuclei are relatively heavy, but different in nuclear structure and shape. The evaluation was performed to increase the photoneutron emission from the preequilibrium process described by the two-component exciton model, using the CCONE code. For this purpose, modifications of the multiplying factor for the state density in the exciton model were made in comparison with the DDX data. Our evaluation for reaction cross-sections and DDXs was compared to the results from JENDL-5, as well as experimental data. The evaluation gives better reproduction of photoneutron emission than JENDL-5 for DDXs at 13 and 17 MeV photon energies while maintaining consistency on the total photoneutron cross-section data available.