A Benchmark Experiment for ¹⁸⁰Hf(n, n')^180mHf Activation Reaction Cross Section with ²⁵²Cf Neutron Source

The authors’ group is conducting benchmark experiments for cross sections of large-angle scattering by deuterium-tritium neutrons. For a benchmark experiment for large-angle scattering, the cross section of lithium, an activation foil that has a large activation reaction cross section in the 7- to 11-MeV energy range, is required. For such a foil, ¹⁸⁰Hf is potential material. However, few benchmark experiments for the ¹⁸⁰Hf(n,n')^180mHf activation reaction cross section have been carried out so far, and thus, the data have uncertainty. Therefore, a benchmark experiment for the activation reaction cross section is indispensable. In this study, we conducted a benchmark experiment for the activation reaction cross section of ¹⁸⁰Hf(n, n')^180mHf by using a ²⁵²Cf neutron source. From the results, we found that the activation reaction cross section in JENDL-5 overestimated the activation reaction cross section by 21.7% in energies of 7 to 11 MeV, so we assume that the shape of the cross-section curve is correct.