Gamma-Ray Spectra of Fission Products observed with Li-Drifted Germanium Detectors, (II)

The γ-ray spectra of short-lived fission products from thermal neutron irradiation of highly enriched U were observed with an encapsulated Li-drifted Ge γ-ray spectrometer. The spectra at various periods—10 min, 30 min, 1,2,5,10 and 20 hr—after irradiation were measured up to about 1 meV. The relative activities of fission products at various periods after irradiation (10 min–20 hr) were calculated and used for assigning photopeaks.