Transition from collective to aligned-particle configurations at high spin in /sup 154/Dy

The high spin level structure of /sup 154/Dy has been determined through the (/sup 34/S,4n..gamma..) reaction. Lifetimes have been measured by use of the recoil-distance method. Both the level structure and lifetimes indicate a transition from collective to few-particle characteristics at high spin, possibly suggesting a changing shape from prolate through triaxial to oblate.