Gamma-ray Spectroscopy of Very Neutron-Deficient Bi Isotopes

Prompt and delayed gamma rays from in Bi-191,Bi-193 have been identified using the recoil-decay tagging (RDT), isomer tagging, and recoil gating techniques, resulting in extensive level schemes for both nuclei. Excitation energies of the isomeric 13/2(+) states have been established and rotational bands based on them have been observed. The nearly spherical 9/2(-)ground-state bands appear to be crossed by more deformed low-lying structures. TRS calculations have been performed and B(M1)/B(E2) ratios have been extracted for the observed strongly-coupled bands. In Bi-193, a 3 mus isomer has been interpreted as a h(9/2) proton coupled to the 12(+) state of the (192)pb core.