Identification of High Spin States in 137,138Cs Nuclei and Shell Model Calculations
Abstract
High spin states of 137,138Cs have been studied by measuring γ - γ - γ coincidences from the spontaneous fission of 252Cf with the Gammasphere detector array. The high-spin level scheme of the N=83 neutron-rich Cs (Z=55) isotope, 138Cs, built on 6- isomeric state, has been established for the first time up to a 4626 keV level, assigned (16+). The level scheme of 137Cs has been expanded up to a 5495 keV level, assigned (31/2-). Spins, parities, and configurations are assigned based on the agreement between experimental level energies and shell model calculations and level systematics. Similarities are observed in the N=82 isotones, 137Cs and 135I up to 17/2+ as well as in the N=83 isotones, 138Cs and 136I up to 12-. The shell-model calculations indicate the important role played by interactions between the excitation of the valence protons outside the Z=50 major shell and the f7/2 valence neutron outside the N=82 major shell.
- Publication:
-
Fission and Properties of Neutron-Rich Nuclei
- Pub Date:
- August 2008
- DOI:
- 10.1142/9789812833433_0008
- Bibcode:
- 2008fpnr.conf...65L