Determination of flux-weighted average cross-sections of natPb(γγ,xn), 208Pb(γγ,xn), and 209Bi(γγ,xn) reactions using bremsstrahlung end-point energies of 50-70 MeV

Abstract

The flux-weighted average cross-sections of the Pb-nat(gamma, xn)Pb198-204 reaction for the bremsstrahlung end-point energies of 50-70 MeV were determined by activation and off-line gamma-ray spectrometric technique, using the 100 MeV electron linac at the Pohang Accelerator Laboratory (PAL), Korea. The relative cross-sections of the Pb-208(gamma, xn)Pb202-204 and Bi-209(gamma, xn)Bi203-206 reactions from our earlier work were updated to absolute values and compared with the present data. The photo-neutron cross-sections of Pb-nat, Pb-208, and Bi-209 were also calculated, as a function of the photon energy using the TALYS 1.6 code. The flux-weighted average cross-sections were obtained from the theoretical values of the TALYS 1.6 code, based on mono-energetic photons, and compared with the present experimental data. The values were found to be in good agreement with the present data for the Bi-209(gamma, xn)Bi203-206, Pb-208(gamma, xn)Pb202-204, and Pb-nat(gamma, xn)Pb198-202 reactions. However, the present data for the Pb-nat(gamma, xn)Pb-203,Pb-204 reactions were higher than the flux-weighted values obtained using the TALYS 1.6 code.