Yrast isomers and very high spin states in 148, 149, 151, 152Dy and 147Gd

Abstract We have studied level schemes for the feeding and decay of high-spin isomers in the nuclei 148, 149, 151, 152 Dy and 147 Gd. A variety of techniques involving γ-ray spectroscopy with pulsed heavy-ion beams have been applied including linear polarization, γ-γ correlations and recoil distance measurements. The general aspect of these level schemes is in accordance with the idea that the states near and along the yrast line can be described by a spheroidal shell model in which the nucleus is axially symmetric with respect to the total spin. In these cases the spin is generated not by collective rotation, but by alignment of many single-particle orbits around a common axis.