Validation of Photoneutron Energy Distributions in Shielding Calculation of the Medical Linac Room

Abstract

It is necessary to consider the effect of photoneutrons produced by photonuclear reactions in the shielding calculation of a medical linac room with incident electron energies greater than 10 MeV. For photonuclear reaction files, the validation of photoneutron energy distributions has not been reported. We compared the evaluated data of photoneutron energy distributions in LA150 and JENDL / PD-2016.1 with the experimental data for 11 nuclides taken from the EXFOR database. For dominant shielding materials of linac, we validated the tendency of energy distributions by comparing the experimental data of neighborhood nuclides. Consequently, we found problems in the evaluations of the photoneutron energy distributions of the photonuclear reaction files.