ENERGY LEVELS OF 243AM

The energy levels of 243Am have been investigated by studying the γ-rays and conversion electrons of 243Pu and α groups of 247Bk by highre-solution semiconductor detectors. Some new γ-rays were identified and the multipolarities of the 381.7 and 356.4 keV transitions were measured to be M1. The half-life of the 84.0 keV level was measured by a delayed β-γ-ray coincidence technique and found to be 2.34±0.07 ns. Nine α groups belonging to 247Bk decay were identified and the favoured transition was found to populate a level at 267 keV above the ground state. The Nilsson-state assignments to the 243Am levels agree with the previous assignments. Coriolis interaction calculations were performed to explain the contraction of the 5 2+ (642↑) band and the branching ratios of the intensities of the γ-rays de-exciting the 7 2+(633↑) band to the rotational members of the 5 2+(642↑) band. The calculated values of the level spacings the γ-ray intensity ratios and α intensity ratios were found to be in good agreement with the respective observed quantities. © 1969.