Shape evolution and superdeformation studies with the Chateau de Cristal

The present status of the properties of the superdeformed structure is first introduced. Recent data are presented on the feeding of the superdeformed band in 149Gd and on the yrast states of the odd-even nucleus 151Tb, obtained with the Chateau de Cristal; in this last nucleus theoretical calculations clearly established shape changes correlated to single particle alignments at high spins. Data on a rotational band in 151Tb characteristic of a superdeformed prolate shape are also presented; comparison with calculations of the observed variation in the J(2) moment of inertia with frequency, in 151Tb and other known cases, suggest that the valence nucleons from the high-N intruder shells have a strong influence on the properties of superdeformed nuclei