Indirect measurement of bremsstrahlung photons and photoneutrons cross sections of 204Pb and Sb isotopes compared with TALYS simulations

A massive sliced Pb-target was irradiated by 20 MeV electrons and the bremsstrahlung photons produced plus the photoneutrons are applied to measure Pb204(γ,n) and Pb204(n,n′) reactions cross section. The radioactivity induced inside the Pb-target slices was measured using γ-spectrometry. Incidentally, the Sb121(γ,n) and (n,γ) besides the Sb123(γ,n) nuclear reactions were also measured, since Sb is added in lead alloys to increase their rigidity. A detailed geometry of the Pb-target has been simulated using the GEANT4 code and the initial photons and neutrons fluence at the entrance of the Pb-target was calculated. The average cross sections of photonuclear reactions on 204Pb and Sb isotopes as well neutrons inelastic reaction on 204Pb and capture on 121Sb were determined. Theoretical cross sections using the TALYS code have been simulated for all isotopes. An agreement between the experimental and simulated results appears while useful conclusions are presented regarding the nuclear parameters used in the simulations after comparison to experimental data.