High-fold γ-ray spectroscopy of 117Xe

Abstract

High-spin states have been populated in 54 117Xe via the 90Zr( 31P, p3n) reaction at 150 MeV, using the EUROGAM II γ-ray spectrometer to record high-fold γ-ray coincidences. Although 117Xe accounts for only 20% of the total fusion cross-section, a high-fold ( γ 4) analysis of this weak channel has significantly extended the level scheme. In particular, the νh 11 2 yrast band has been extended to I π = ( 91 2 − ) and shows features which are consistent with those of smooth band termination at high spin. The high-spin behaviour of 117Xe is discussed within the framework of cranked Nilsson-Strutinsky calculations. In addtion, measured B(E1) strengths are discussed in terms of possible octupole correlations in this mass region.