Yrast states of neutron-rich N=83 nuclei from fission product gamma-ray studies

Prompt gamma-ray cascades in N=83 fission product nuclei near Sn-132 have been studied at Eurogam II using a Cm-248 source. Cross coincidences observed between gamma rays from complementary light and heavy fission fragments were vital for isotopic assignments. Yrast states in the N=83 isotones Sb-134, Te-135, and I-136, reported. The interpretation of the level schemes is based mainly on results of shell model calculations using empirical proton-proton interaction energies from Te-134, and proton-neutron interactions estimated from the well-known Bi-210 level spectrum.