Detailed Band Structures In Hg-189 And Hg-190

The level structures of the 189Hg and 190Hg nuclei have been extended considerably from earlier studies by using the Gd-160(S-34, 4n and 5n) reactions in conjunction with an array of twelve Compton suppressed Ge detectors. Eight band structures have been delineated in 189Hg and ten in 190Hg. Most bands can be understood within the framework of cranked shell model calculations assuming an oblate collective shape and specific quasiparticle configurations are proposed. There is also some evidence for the onset of triaxiality. In both nuclei level structures which appear to be non-collective in character are interpreted in a band termination picture.