Study on the giant dipole resonance model for γ production mechanisms induced by fast neutrons in the nuclear mass region 180≤A≤210

The subjects related to the giant dipole resonance model for the γ production mechanisms induced by fast neutrons have been studied in the nuclear mass region 180≤A≤210. It contains the difference between the γ-ray strength functions of the cascade γ deexcitation processes in the (n, γ) and (n, n'γ) reactions as well as the variation tendency of the reaction cross section ratios between the direct-semidirect radiative captures and the compound nucleus statistical processes with the incident energies, nuclear mass numbers and the nuclear shells. The numerical calculations and the comparisons with the experimental values for 181Ta, 197Au and 208Pb have been done in the neutron incident energy region from 1 MeV to 20 MeV. The analyses and discussions to the results have also been given