Evidence for High Spin States in $^{70}$Ga

High-spin states in the odd-odd $^{70}$Ga nucleus were populated at Florida State University using the $^{62}$Ni($^{14}$C, $\alpha$pn) fusion-evaporation reaction at a beam energy of 50 MeV. Gamma rays that depopulated the $^{70}$Ga excited states were recorded in coincidence with a Compton-suppressed Ge array consisting of three clover detectors and seven single-crystal detectors. The existing $^{70}$Ga level scheme was modified, enhanced, and extended to higher spin with the addition of eight new transitions based on the analysis of double- and triple-coincidence $\gamma$-ray spectra. Five of these transitions are associated with a new rotational band that may be based on the occupation of the $g_{9/2}$ orbital by the unpaired proton and neutron. The normalized energy differences between adjacent spin states in this new band indicate a signature-splitting pattern that is characteristic of other such bands in neighboring odd-odd nuclei. Similarly, the kinematic moments of inertia deduced for this decay sequence evolve with angular frequency in a manner typical of analogous bands in other odd-odd nuclei in this mass region.