GAMMA DECAY OF 75SE

A study was made of the γ-ray spectrum of 75Se using a variety of Ge(Li) detectors. The energies and intensities of 14 lines have been measured: 24.4 keV (0.044±0.006), 66.0 keV (1.72±0.04), 96.7 keV (5.12±0.10), 121.1 keV (27.7±0.50), 136.0 keV (95.00±1.80), 198.6 keV (2.38±0.07), 264.6 keV (100.0), 279.5 keV (42.0±0.80), 303.8 keV (2.19±0.07), 400.5 keV (20.40±0.50), 419.3 keV (0.023±0.002), 468.6 keV (0.001±0.0005), 572.6 keV (0.063±0.002), and 617.7 keV (0.0075±0.0002). Of these a 24.4 keV and 468.6 keV transition were substantiated for the first time in the γ-ray spectrum. The 80.8 keV transition deducedd from electron conversion spectra and a 373 keV transition previously reported in the γ-ray spectrum of 75Se were not observed. K X-ray intensities and branching ratios have been determined. The results of this work support the conclusions of previous studies in the decay of 75Ge and in the Coulomb excitations of 75As for the existence of a level at 468.6 keV. A modified γ-decay scheme of 75Se to include the 468.6 level is proposed. © 1969.