Magic Nucleus S

Prompt and delayed γ -ray cascades in doubly magic 132Sn and its neighbor 131Sn have been studied at Gammasphere using a 248Cm fission source. Isotopic assignments of unknown γ rays were based on coincidences with known transitions in A=112--116 Pd fission partners. The yrast level spectra of both tin nuclei are interpreted using empirical nucleon-nucleon interactions from the 132Sn and 208Pb regions. Results include identification of the (νf7/2 h-111/2)9+ aligned state in 132Sn and of extensive (νf7/2 h-211/2) , (νf7/2 d-13/2 h-111/2) and (νh-111/2 x 3-) multiplets in 131Sn . The previously reported β- decay of an unusual 131In high-spin isomer to levels in 131Sn is also elucidated