Level structure in 152Gd studied in the decay of 17.5 h 152Tb

Abstract

The decay of 152Tb(17.5 h) has been studied using Ge(Li) detectors to obtain singles spectra and to perform γ-γ coincidence experiments. More than 290 transitions are observed, of which about 100 were not previously reported. A revised decay scheme is proposed in which most of the observed transitions are attributed to the decay of 67 proposed states in 152Gd. Experimental internal-conversion coefficients are calculated using previously reported conversion-electron intensities and the γ-ray intensities obtained in this investigation. Branching ratios are compared to those obtained for analogous levels in other transitional nuclei, and an attempt is made to interpret the known level structure of 152Gd in terms of quasirotational bands. Quasi β, γ, βγ and 2β bands, as well as K = 0 and K = 1 octupole bands, are proposed. A level at 1862.0 keV is interpreted as the 2 + member of a possible quasi 3β band while a 2 + state at 1941.2 keV is interpreted as the bandhead of a possible quasi (γ-2β) band.