Thermal Neutron Capture Cross Section of 232Pa

Abstract

There are measured radiation capture cross-sections of neutrons σnγ(232Pa) caused by a short-lived (T1/2=31.44 hour) nucleus of 232Pa near the thermal point. The samples of 231Pa weighing ˜50 μg were irradiated in a flux of neutrons ofIRT reactor (MEPI, Moscow). σnγ was calculated as related to the amount of built up in the course of irradiation atoms of 232Pa and 233Pa (T1/2=27 day). The build-up of 232Pa and 233Pa was defined by the results of irradiated samples γ-spectrometry performed with the use of radiometric measurement complex belonging to MEPI. The contribution of epicadmium neutrons was taken into account as to 233Pa build-up in the samples of 233Pa irradiated in cadmium cases. Thermal neutron capture cross section of 232Pa constituted σth=(655±69) barn. © 2014 Atomic Energy Society of Japan. All Rights Reserved.