The Decay Scheme ofCu66

The decay scheme of ${\mathrm{Cu}}^{66}$ has been investigated using scintillation detectors. The half-life of ${\mathrm{Cu}}^{66}$ was found to be 5.17±0.07 min. The main beta-ray spectrum has an end point of 2.7±0.1 Mev. 5½±1½ percent of the beta-rays lead to an excited state of 1.05±0.03 Mev in ${\mathrm{Zn}}^{66}$. The half-life of this excited state is less than 5×${10}^{-9\mathrm{}}$ sec. These results agree with the recent investigations of Friedlander and Alburger, but imply the necessity for further study of the decay scheme of ${\mathrm{Ga}}^{66}$, which also decays to ${\mathrm{Zn}}^{66}$. Spin, parity and shell model assignments of the pertinent states of ${\mathrm{Cu}}^{66}$, ${\mathrm{Zn}}^{66}$, and ${\mathrm{Ga}}^{66}$ are proposed.