Pa233(n,γ) cross section extraction using the surrogate reaction Th232</mml:mn…

The neutronic properties of ²³³Pa play a crucial role in the thorium fuel cycle since it directly impacts the inventory of the fissile isotope ²³³U. Currently, the experimental data of the ²³³Pa(n,0.16em0exγ) cross section are rather scanty with poor accuracy and significant discrepancy exists in the experimental and evaluated data. In this work, the ²³³Pa(n,0.16em0exγ) cross section is studied through the surrogate reaction ²³²Th(³He,0.16em0exp)²³⁴Pa*. The spin-parity (SP) distribution of the ²³²Th(³He,0.16em0exp)²³⁴Pa* is calculated with the distorted wave Born approximation and then the ²³³Pa(n,0.16em0exγ) cross section is extracted using the statistical Hauser-Feshbach model. It is found that the extracted ²³³Pa(n,γ) data considering the SP distribution have a tendency to agree with the evaluated nuclear data files, ENDF/B-VIII.0 and JENDL-5, whereas the experimental ones without considering the SP distribution are visibly higher than the evaluated data. This suggests that the SP distribution should be considered reasonably when employing the surrogate-reaction method to extract the ²³³Pa(n,0.16em0exγ) cross section.