Search for extremely deformed systems in {sub 182}Os
- and others
We performed an experiment at Gammasphere to search for elongated shapes in the nucleus {sup 182}Os. Recent calculations by R. R. Chasman show that this nucleus is the most promising for finding structures with major to minor axis ratios of 2.2:1 or greater. These calculations include a necking degree of freedom which is thought to be an improvement over past cranked Strutinsky calculations where predictions for extended shapes in Yb and Er nuclei were made. In order to populate {sup 182}Os at spins > 60 h, we utilized the {sup 139}Ba({sup 48}Ca,4n) reaction. The target was made by evaporating {sup 138}Ba onto a 500-{mu}g/cm{sup 2} Au foil, followed by the evaporation of {approximately}250-{mu}g/cm{sup 2} Au onto the exposed side of the Ba. Such a target was necessary since Ba is highly reactive with oxygen. Even after taking this precaution, the target suffered oxidation which adversely effected the quality of our data. The experiment was performed at Gammasphere using the predetermined energy of 220 MeV. A single target was used and the {sup 138}Ba had a thickness of 750 {mu}g/cm{sup 2}. The run lasted four days and {approximately}440 x 10{sup 6} 3-fold and higher Compton-suppressed Ge events were collected. No strong evidence for highly deformed structures was found in this data set. However, it is our belief that the oxygen contamination in our target greatly compromised the outcome of the experiment. Much of the background in our total projection is due to fusion reactions of {sup 48}Ca on oxygen isotopes. The resulting {gamma} rays are highly Doppler broadened and experience larger Doppler shifts relative to the Os residues. Thus, these {gamma} rays are spread out over the entire energy spectrum almost uniformly adding to the background. Our conclusion is that due to target problems, only 150-200 million of the coincidence events can be associated with Os-like residues.
- Research Organization:
- Argonne National Lab. (ANL), Argonne, IL (United States)
- OSTI ID:
- 166313
- Report Number(s):
- ANL-95/14; ON: DE96000985; TRN: 95:007970-0025
- Resource Relation:
- Other Information: PBD: Aug 1995; Related Information: Is Part Of Physics Division Annual Report, April 1, 1994--March 31, 1995; Henning, W.F.; PB: 207 p.
- Country of Publication:
- United States
- Language:
- English
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