SMOOTH BAND TERMINATION IN SN-108

Three rotational bands in Sn-108 have been investigated to high freque ncy via the Fe-54(Ni-58,4p) reaction at 243 MeV. One of these bands is observed to undergo a band crossing at high spin. All three bands sho w a large decrease in their dynamic moments of inertia, to approximate ly one third of the rigid body value, as the rotational frequency appr oaches 1 MeV/h. The structures of these bands are thought to be based on 2p-2h proton excitations across the Z=50 shell gap and their proper ties can be interpreted in terms of cranked Nilsson-Strutinsky calcula tions. Such calculations predict smooth band terminations for all thre e structures and a gradual shape change from collective prolate, at lo w spin, to noncollective oblate at high spin.