ROTATIONAL AND SINGLE-PARTICLE STRUCTURES IN ZR-83

The band structure of Zr-83 has been investigated using the Daresbury recoil separator and TESSA array with 20 Compton suppressed Ge detectors and the reaction Si-28 (Ni-58, 2pn) at 195 MeV. DCO ratios have been used to make many new spin assignments. The three known rotational bands have been extended up to the onset of the five quasiparticle bands. On the basis of the 21/2+, 23/2+ and 25/2+ yrast and yrare states, a (3 qp) structure similar to those found in the isotones Kr-79 and Sr-81 has been identified. Additional bands have been observed for the first time, one of which appears to be non-collective. Strong mixing between the various negative parity bands is evident. A multiplet of states feeding the three quasiparticle region of the negative parity yrast band has been found. The data is interpreted in the framework of the cranked shell model.