Prompt gamma-ray spectroscopy of neutron-rich nuclides produced in the spontaneous fission process of {sup 252}Cf
Nuclear spectroscopy was performed on neutron-rich nuclides produced by the spontaneous fission process of {sup 252}Cf. The data were taken with the Compton-suppressed Ge-detector spectrometer at the Holifield Heavy Ion Research Facility. The prompt {gamma}-ray transitions were isolated by using {gamma}-{gamma} and {gamma}-{gamma}-{gamma} coincidence techniques. Nine new states were observed in {sup 110}Ru, four of which constitute a gamma band structure up to J{sup {pi}} = 7{sup +}, and an additional J{sup {pi}} = 12{sup +} state which was assigned to the yrast band. The level scheme of {sup 110}Ru is compared to {sup 104}Ru and {sup 192}Os, the latter of which shares with {sup 110}Ru the distinction of having the lowest {gamma}-bandhead. Calculations with both the {gamma}-rigid triaxial nuclear model and the IBA 0(6) Hamiltonian gave acceptable fits for the yrast band, but predicted a doublet clustering of states for the {gamma}-band, which was not observed experimentally. Studies of nuclei around doubly magic {sup 132}Sn revealed for the first time energy levels of {sup 136}Te and new high spin states in {sup 134}Te, {sup 138,140}Xe, and {sup 140}Ba. The states in the yrast band of the N = 84 isotones {sup 136}Te, {sup 138}Xe, and {sup 140}Ba were determined up to 12{sup +}, 12{sup +} and 8{sup +}, respectively. The discovery of the 6{sup +} states provided an almost complete energy level systematics for the N = 84 isotones in the pseudospin {bar f}{sub 7/2} shell. The energy levels of the isotopes {sup 136}Te and {sup 138}Xe were shown to exhibit remarkable similarities to the isotopes {sup 204}Po and {sup 206}Rn. This approximate symmetry was ascribed to the underlying shell model structure. Based upon the shell model calculations for {sup 204}Po, the 8{sup +}, 10{sup +}, and 12{sup +} states of {sup 136}Te were hypothesized to involve core excitations of {sup 134}Sn. The higher spin states of the neutron-rich Pd isotopes {sup 110,112,114}Pd were identified.
- Research Organization:
- Vanderbilt Univ., Nashville, TN (United States)
- OSTI ID:
- 98651
- Resource Relation:
- Other Information: TH: Thesis (Ph.D.); PBD: 1993
- Country of Publication:
- United States
- Language:
- English
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