SOME NEW ASPECTS OF NUCLEAR-STRUCTURE AT HIGH SPINS

This paper will focus on the properties of lead and some neighboring n uclei at high spins where they have exotic shapes, such as superdeform ed (SD) and oblate. The limits of the region of superdeformation aroun d mass 190 will be explored. On the heavy side, the lead nuclei form t he high-Z limit. On the light side, a new SD band has been observed in 191Au, the first one in a gold nucleus, extending the low-Z limit. Co llective oblate bands, not often found in the nuclear chart, have rece ntly been observed in a number of lead nuclei (and also in Tl and Hg n uclei) at high spins. They are favored because the Fermi level is loca ted near the oblate-driving high-K h9/2 and i13/2 proton orbitals. The ir properties will be examined. A summary of what we hope to learn in the near future will conclude this paper.