Deformed i{sub 13/2} bands and prolate-oblate shape coexistence in {sup 185}Tl and {sup 187}Tl.
High spin states in the very neutron-deficient isotopes {sup 185}Tl and {sup 187}Tl have been identified from {gamma}-{gamma} coincidence measurements performed with the reactions {sup 154}Gd({sup 35}Cl, 4n) and {sup 159}Tb({sup 32}S, 4n). Unambigous mass assignments were obtained using a Fragment Mass Analyzer and the reactions {sup 154}Gd{sup 36}Ar, p4n and {sup 155}Gd({sup 36}Ar, p3n). Structures are observed corresponding to both an i{sub 13/2} proton coupled to a prolate deformed core, and also h{sub 9/2} and i{sub 13/2} protons coupled to an oblate deformed core. The proposed 13/2{sup +}[606] intrinsic states are isometric, with meanlives of 12{+-}2 ns in {sup 185}Tl and 1.0{+-}0.2 ns in {sup 187}Tl. Equilibrium deformation calculations for the excitation energies of intrinsic states reproduce general trends, but overestimate the bandhead energies of high-j states.
- Research Organization:
- Argonne National Laboratory (ANL)
- Sponsoring Organization:
- ER
- DOE Contract Number:
- AC02-06CH11357
- OSTI ID:
- 937697
- Report Number(s):
- ANL/PHY/JA-12174
- Journal Information:
- Phys. Lett., Journal Name: Phys. Lett. Journal Issue: 1994 Vol. b324; ISSN 0375-9601; ISSN PYLAAG
- Country of Publication:
- United States
- Language:
- ENGLISH
Similar Records
Identification of yrast states in {sup 187}Pb
The spectroscopy of {sup 183}Tl: an extreme case of prolate-oblate shape-competition