LEVEL STRUCTURE OF GA66

The excited levels of Ga66 have been investigated from the decay of Ge66 with high resolution Ge(Li) and Si(Li) detectors and with standard scintillation counters. Ge66 was produced by the (α,2n) reaction on enriched Zn64. A chemical separation for Ge was performed. γ rays of the following energies (in keV) and intensities have been assigned to the decay of Ge66: 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 Ga66 is given. The spin and parity assignments of some of the low excited levels of Ga66 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 sec and (1.2×0.2)×10-9 sec, respectively. © 1969 The American Physical Society.