NUCLEAR-STRUCTURE OF ODD-ODD Y-82

Excited states in Y-82 have been investigated via the (Ni(Si,3pn)Y)-Ni -58-Si-28-Y-82 and (Fe(Si,p2n)Y)-Fe-56-Si-29-Y-82 reactions using beam s provided by the Florida State University Tandem-LINAC with energies of 95 to 135 MeV. Particle-gamma coincidences with a full-sphere charg ed-particle detector and an excitation curve were used to assign gamma rays to Y-82. The (Fe(Si,p2n)Y)-Fe-56-Si-29-Y-82 reaction at 95 MeV w as used to measure gamma-gamma coincidences with five Compton-suppress ed Ge detectors. Lifetimes in the ns and ps ranges were measured using direct timing and the Doppler-shift attenuation method. A level schem e with 39 states was constructed up to tentative spins and parities of (15-) and (21+). In the positive-parity yrast band a phase reversal w as observed in the signature splitting at I = 10hBA. The B(Ml) strengt hs in this band alternate with signature between about 0.1 and 1.0 mu( N)2. The B(E2) strengths of about 90 Weisskopf units are in good agree ment with those predicted by Hartree-Fock-Bogolyubov calculations. Par ticle-rotor calculations indicate a prolate or triaxial core shape for the positive-parity band.