Radioactive Decay ofZn72

The decay of ${\mathrm{Zn}}^{72}$ (46.5h) has been investigated using standard scintillation counter techniques. Samples of ${\mathrm{Zn}}^{72}$ were obtained from the fission of ${\mathrm{Th}}^{232}$ and ${\mathrm{Ta}}^{181}$ by fast protons. Gamma rays of 51±3, 143±2, and 192±4 keV were observed. A beta-ray group of 296±6 keV was found in the singles and in coincidence with the 143-keV gamma. A decay scheme is proposed for ${\mathrm{Zn}}^{72}$.