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

The relevant absolute gamma-ray emission probabilities from the beta-decay of Np-238 were measured by means of alpha- and gamma-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 gamma-rays, respectively, in agreement with the previous measured ones. These intensities were used to deduce the thermal neutron capture cross section of Np-237 for which a value of (182.2 +/- 4.5) b is obtained higher by 11% than the recommended value. (C) 2009 Elsevier Ltd. All rights reserved.