Measurement of flux-weighted average cross sections for 197Au(γ, xn) reactions and isomeric yield ratios of 196m,gAu with bremsstrahlung

Photo-neutron cross sections of 197Au were experimentally determined for the bremsstrahlung end-point energies of 50, 60, and 70 MeV, by utilizing activation and off-line γ-ray spectrometric technique, using the 100 MeV electron linac at the Pohang Accelerator Laboratory (PAL), Pohang, Korea. The 197Au(γ, xn; x=1-6) reaction cross sections were calculated as a function of the bombarding photon energy by using the TALYS 1.6 computer code with default parameters. The flux-weighted average cross sections were obtained from the literature data and the theoretical values of TALYS 1.6 and TENDL-2014, for mono-energetic photons, and are found to be in good agreement with the present data. Isomeric yield ratios of 196m2,gAu from the 197Au(γ, n) reaction were also determined for the bremsstrahlung end-point energies of 50, 60, and 70 MeV, from the reaction cross sections of m2- and g-states, based on the present experimental data, and are found to be in good agreement with the theoretical values based on TALYS 1.6 and TENDL-2014.