SEARCH FOR OCTUPOLE DEFORMATION IN NEUTRON-RICH XE ISOTOPES

A search for octupole deformation in neutron-rich Xe isotopes has been conducted through prompt gamma-ray spectroscopy of secondary fragment s produced in the spontaneous fission of Cm-248. nh, spectrometer cons isted of the Eurogam 1 array and a set of 5 LEPS detectors. Level sche mes were constructed for Xe isotopes with mass number ranging from 140 to 144 and excited states for Xe-143,Xe-144 nuclei were observed for the first time. None of the level schemes exhibit an alternating parit y quasimolecular band, a feature usually expected in nuclei in which o ctupole correlation effects are strong enough to produce stable octupo le deformation. For several isotopes, structures observed in the level schemes are consistent with an octupole softness of the nuclei.