Decay ofCu61and Energy Levels inNi61

Abstract

The 3.3-h positron decay of ${\mathrm{Cu}}^{61}$ has been investigated by use of Ge(Li) detectors and coincidence techniques. A total of 19 $\gamma$-ray transitions have been observed ranging in energy from 67 to 2120 keV, of which only eight had been reported previously. The decay scheme based on these data incorporates all of these transitions and requires only those ${\mathrm{Ni}}^{61}$ levels that have been excited in nuclear reactions. The excitation energies of the levels observed to be populated in ${\mathrm{Ni}}^{61}$ from the decay of ${\mathrm{Cu}}^{61}$ are 67.3, 282.8, 655.7, 908.8, 1100.2, 1132.4, 1185.5, 1446.9, 1611.8, 1730.2, and 2119.8 keV.