The level structure of 184Os from 184Ir decay and 185Re(p, 2nγ) in-beam spectroscopy

Abstract

Levels of 184Os populated in the decay of 3.1 h 184Ir and in the 185Re(p, 2nγ) reaction have been investigated. The measurements included γ-ray singles, β + ray endpoint, conversion coefficient, β +- γ coincidence and detailed γ-γ coincidence determinations. The results have established an extensive 184Os level scheme, which includes well developed ground state, γ-vibrational and K = 3 octupole bands and which accommodates all the intense transitions observed in both the radioactivity and in-beam γ-ray measurements. Deviations of the level energies in the K π = 0 +and K π = 2 + bands and of the interband reduced transition probabilities from the predictions of the strong-coupling model are discussed in terms of the rotationvibration interaction, and the systematics of the octupole vibrational excitations in even-mass W and Os nuclei are reviewed. It is concluded that the 184Ir ground state configuration has a spin of 5, and that it contains large admixtures of K = 0 or K = 1 character.