Yrast spectroscopy of N=82,83 isotopes Xe-136 and Xe-137 from Cm-248 fission

Prompt gamma-ray cascades in neutron-rich nuclei around doubly magic Sn-132 have been studied at Eurogam II using a Cm-248 fission source. Here we rep ort results for the f our-valence-proton N = 82 nucleus Xe-136 and for its N = 83 neighbor Xe-137. For both nuclei, the yrast level spectra have been considerably extended, and empirical nucleon-nucleon interactions have been used to assign probable shell model configurations. The Xe-136 level energ ies are compared with those calculated using different sets of proton-proto n interaction matrix elements, both diagonal and nondiagonal, obtained by f itting experimental data for other N = 82 isotones.