Photoneutron reaction cross-section data for As75 : Experiments and evaluation

Abstract

The problems of reliability of partial photoneutron cross-section data for $^{75}\mathrm{As}$ obtained using beams of quasimonoenergetic photons produced by annihilation in flight of relativistic positrons and the method of neutron multiplicity sorting at Lawrence Livermore National Laboratory (USA) and Centre d'Etudes Nucleaires of Saclay (France) were discussed using the objective physical data reliability criteria. New data for photoneutron reaction cross sections for $^{75}\mathrm{As}$, satisfying those criteria, were obtained using the experimental-theoretical method for partial reaction cross-section evaluating. Evaluated data for $^{75}\mathrm{As}$ were compared with experimental data and the problems of significant disagreements between Livermore and Saclay data were discussed in detail. It was shown that experimental data for the $(\ensuremath{\gamma},1n)$ and $(\ensuremath{\gamma},2n)$ reactions' cross sections obtained at Livermore are not reliable because of significant systematic uncertainties of different nature.