New insights from studies of spontaneous fission: Yields and neutron multiplicities, cold fission, and structure of neutron-rich nuclei
An overview of many of the new insights extracted from {gamma},{gamma} and {gamma}-{gamma}-{gamma} coincidence studies of spontaneous fission of {sup 252}Cf and {sup 242}Up with large detector arrays at ORNL and Gammasphere will be presented. These include direct measurements of yields and neutron multiplicities from 0 to l0v for five correlated pairs, identification of a number of cold fission (cluster radioactivity) channels, identification of new structures and behaviors in many neutron-rich nuclei from {sup 94}Sr to {sup 160}Sm. From the yields of the correlated pairs, a new, second mode of SF is observed in the Mo-Ba pairs with much lower total kinetic energy. This mode goes via a hyperdeformed shape (3:1 axis ratio) for {sup 144}Ba, {sup 145}Ba, or {sup 146}Ba. Calculations indicate a third minima in {sup 252}Cf at {Beta}{sub 3} {approximately} 0.7 and {Beta}{sub 2} {approximately} 0.9. The zero neutron cluster radioactivity yields for odd-odd Mo-Ba pairs are about four times larger than for the even-even ones in agreement with recent cluster radioactivity predictions. Identical bands are observed in {sup 98, 100}Sr, {sup 108, 110}Ru, {sup 144,146}Ba, and {sup 152,154}Nd nuclei and new types of identical bands in {sup 156,158,160}Sm nuclei, and the first identical octupole bands. Octupole deformation is seen in N = 86, {sup 142}Ba, {sup 144}Ce and the new high spin octupole states to 19{sup -} exhibit the first backbending and quenching of the static octupole strength as predicted by theory. Selected examples of the new physics being seen will be presented.
- OSTI ID:
- 255596
- Report Number(s):
- CONF-9510116--
- Journal Information:
- Bulletin of the American Physical Society, Journal Name: Bulletin of the American Physical Society Journal Issue: 10 Vol. 40; ISSN BAPSA6; ISSN 0003-0503
- Country of Publication:
- United States
- Language:
- English
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