Correction of the thermal neutron capture cross section of 241Am obtained by the Westcott convention

Abstract

ABSTRACTThere is large discrepancy among the reported experimental data of the thermal neutron capture cross section of 241Am, where the activation measurements provided larger cross sections than those in the time-of-flight ones. The Westcott convention has been widely used for the derivation of the thermal neutron capture cross section in the activation measurements. We have estimated that this large discrepancy is due to the existence of the resonances below the cadmium cut-off energy (ECd ∼ 0.5 eV). By reviewing the Westcott convention, we developed the correction method taking account of the contribution of the resonances near or below ECd. The correction term was evaluated using the JENDL-4.0. Application of the present method successfully improved the existing discrepancy of the thermal capture cross section of 241Am.