High-spin bands in Kr80

High-spin states in Kr80 were studied using the Cu65(18O,p2n) reaction at 65 MeV. Prompt - coincidences were measured using the Pitt-FSU detector array with nine high-purity Compton-suppressed Ge detectors and a 28-element Bismuth Germanate multiplicity filter. The previous level scheme has been extended by 16 new states up to spins and parities of 20+ and (19-). The known band crossing in the positive-parity yrast band of Kr80 near Latin small letter h with stroke 0.5 MeV may be due to a g9/2 neutron alignment, rather than a g9/2 proton alignment as had been previously thought, based on the predicted oblate shape by Hartree-Fock-Bogolyubov calculations. No evidence was found for a second crossing in the yrast sequence up to Latin small letter h with stroke=0.9 MeV. The new extension of the ground-state band through nonyrast states points to another band crossing at Latin small letter h with stroke 0.62 MeV which may be caused by a g9/2 proton alignment. A new negative-parity high-spin band shows that rotational bands do form at excitations above the strongly mixed low-spin levels as in the isotone Sr82.