Calculations of the Gamma energy spectra from neutron radiative capture reactions for 197Au

The authors theoretically explain the abnormal protuberances near and above 5.5 MeV in the gamma spectra of the (n,γ) reactions of the nuclei within the nuclear mass regions from 110 to 140 and from 180 to 210, respectively. Supposing that in the primary and cascade gamma de-excitation processes of the compound nucleus, in addition to the giant dipole resonance model, there exist the de-excitation processes of the excited states of 6He, 6Li, 6Be, 7Li and 7Be particle cliques, for which the gamma-ray strength function was developed. The (n,γ) reaction cross sections and the gamma energy spectra at the neutron incident energies from 0.01 MeV to 3 MeV for 197Au were calculated and the results are in better coincidence with the experimental data. Especially for the gamma energy spectra, the abnormal protuberances near and above 5.5 MeV were reproduced very well