SUPERDEFORMED BANDS IN SR-80 AND THE EVOLUTION OF DEFORMATION IN SR ISOTOPES

Four superdeformed bands are reported in Sr-80, extending known superd eformation in the Sr-38 series down to N = 42. The characteristics of these bands are discussed. Residual Doppler shifts were measured and a verage transition quadrupole moments (Q(t)) inferred for these new ban ds, These Q(t) values are compared to Q(t) values obtained for previou sly identified superdeformed bands in Sr81-83. The low Q(t) of 2.7(-0. 6)(+0.7) eb obtained for the yrast band in Sr-80 indicates a reduction in the deformation of yrast superdeformed bands in the series Sr80-83 with decreasing N, and possibly the onset of triaxiality in superdefo rmed shapes. (C) 1997 Elsevier Science B.V.