Emission probabilities of γ-rays from 238Np and their use for determination of the thermal neutron capture cross section of 237Np

The relevant absolute γ-ray emission probabilities from the β-decay of 238Np were measured by means of α- and γ-spectroscopic techniques. We obtained values of (25.6±0.4)%, (8.9±0.2)% and (18.8±0.3)% for the 984.45-, 1025.87- and 1028.54-keV γ-rays, respectively, in agreement with the previous measured ones. These intensities were used to deduce the thermal neutron capture cross section of 237Np for which a value of (182.2±4.5) b is obtained higher by 11% than the recommended value.