The excited levels of ${\mathrm{Ga}}^{66}$ have been investigated from the decay of ${\mathrm{Ge}}^{66}$ with high resolution Ge(Li) and Si(Li) detectors and with standard scintillation counters. ${\mathrm{Ge}}^{66}$ was produced by the ($\alpha ,2n$) reaction on enriched ${\mathrm{Zn}}^{64}$. A chemical separation for Ge was performed. $\gamma$ rays of the following energies (in keV) and intensities have been assigned to the decay of ${\mathrm{Ge}}^{66}$: 44.3±0.5 (70), 65±0.5 (17), 91±0.5 (2), 109.3±0.5 (43), 125±0.5 (1), 148±0.5 (1), 155±0.5 (<1), 168±1 (%1), 182±0.5 (26), 190±0.5 (25), 234.5±1 (<1), 246±0.5 (24), 272±0.5 (40), 291±1 (1), 303±1 (10), 324±1 (<1), 338±1 (22), 382±1 (100), 414±1 (2), 428±1 (2), 471±1 (43), 493±1 (3), 537±1 (25), 574±1 (1.5), 595.5±1 (2.5), 638±1 (3.5), 661±1 (2.5), 705±1 (21), 756+1 (5), 821±1 (∼1), and 865±1 (3) keV. The use of two Ge(Li) detectors in coincidence studies has revealed the presence of several previously unreported transitions. Based on these results, a consistent level scheme of ${\mathrm{Ga}}^{66}$ is given. The spin and parity assignments of some of the low excited levels of ${\mathrm{Ga}}^{66}$ are discussed. The half-lives of the 44.3- and 109.3-keV levels have been measured by delayed coincidence to be (12±1)×${10}^{-9\mathrm{}}$ sec and (1.2×0.2)×${10}^{-9\mathrm{}}$ sec, respectively.

• Received 23 December 1968

DOI:https://doi.org/10.1103/PhysRev.184.1142