Photonuclear reaction cross-section evaluation of ¹⁸¹Ta and ²⁰⁹Bi considering experimental double differential cross-section data

Experimental data of photoneutron double differential cross-sections (DDXs) on 181 Ta and 209 Bi for photon energies of 13 MeV and 17 MeV were incorporated into the photonuclear data evaluation using the CCONE code system and reaction cross-section data from the EXFOR database. By increasing the preequilibrium photoneutron emissions through a reduction in single-particle state density of neutron for the target nuclei within the exciton model, the evaluation results, including the reaction cross-sections and DDXs for 13 MeV photons, show good agreement with the corresponding experimental data. However, the evaluation results underestimate the experimental DDXs for 17 MeV photon energy.