DECAYS OF THE Y-97 ISOMERS TO THE SINGLE NEUTRON-NUCLEUS ZR-97

The decays of the 9/2(+) and of the three-quasiparticle high spin isom er in Y-97 have been investigated following on-line mass separation wi th the ion-guide technique. Spins and parities for several of the lowe st-lying levels in the daughter nucleus Zr-97 are revised and configur ations are proposed. In particular, the 2264 keV level is identified a s the h(11/2) single-neutron level. The population of a cascade on top of the h(11/2) level provides evidence for Gamow-Teller beta decay of the high-spin Y-97 isomer. Levels and transition rates are qualitativ ely well reproduced by regarding Zr-97 as a single-neutron nucleus wit h respect to the doubly closed Zr-96 core.