Calculation and Analysis of Double-Differential Cross Sections for n + ²⁰⁹Bi Reaction

Based on the experimental data of the total, nonelastic-scattering, and elastic-scattering cross sections and the elastic-scattering angular distribution of ²⁰⁹Bi, a set of optimal neutron optical potential parameters is obtained, and all cross sections of the neutron-induced reaction, angular distribution, energy spectra, gamma-ray production cross sections, and gamma-ray production energy spectra, especially the double-differential cross section for neutron, proton, deuteron, triton, and alpha-particle emission, are calculated and analyzed for n + ²⁰⁹Bi at incident neutron energies <20 MeV. Theoretical calculated data are compared with existing experimental data and other evaluated data from ENDF/B6 and JENDL-3.