Gamma rays emitted in the decay of 238Np

A stock solution of 238Np was produced by the 237Np(n,γ) reaction and was purified by solvent extraction. Three small portions were used to measure absolute activity by liquid scintillation counting, and two large portions were used to obtain γ-ray spectra with Ge detectors. Intensities for strong γ rays (e.g., 25.17±0.13% for 984.17 keV) agree within ∼1% with current evaluations, but several transitions previously assigned to and from the 968-keV level in 238Pu are unlikely to be present. The β counting yielded a half-life of 2.1024±0.0005 days for 238Np.