Positron Decay of ${\mathrm{Cu}}^{59}$ and ${\mathrm{Cu}}^{61}$ and Energy Levels in ${\mathrm{Ni}}^{59}$ and ${\mathrm{Ni}}^{61}$

The energies and relative intensities of the gamma rays following the positron decay of ${\mathrm{Cu}}^{59}$ have been determined. The energies are 0.343±0.004, 0.463±0.010, 0.872±0.005, 1.305±0.005, and 1.70±0.01 Mev, with respective relative intensities of 16±3, 15±5, 29±4, 36±4, and 4±2%. The half-life of ${\mathrm{Cu}}^{59}$ was measured to be 81.5±0.5 seconds. The energies of ground-state transition gamma rays following the positron decay of ${\mathrm{Cu}}^{61}$ were measured as 0.070±0.002, 0.282±0.003, 0.659±0.003, and 1.192±0.005 Mev. The accumulated works of several authors are discussed and compared.