Decay of theZn71Isomers

The decay of the ${\mathrm{Zn}}^{71}$ isomers has been reinvestigated using scintillation counter techniques. Samples of enriched ${\mathrm{Zn}}^{70}$ were exposed to reactor neutrons. Gamma rays of 120±5, 390±10, 510±5, 680±20, 920±10, 1120±10, and 1630±10 kev were found in the decay of the 2.45±0.10-min isomer. A beta ray group to the ground state of ${\mathrm{Ga}}^{71}$ with energy of 2.61±0.05 Mev was found from the 2-min isomer. Gamma rays of 390±5, 490±5, and 610±5 kev were found to be in cascade in the 4.0±0.1-hr isomer and to be fed by a single beta group of 1.46±0.05 Mev. A decay scheme for the ${\mathrm{Zn}}^{71}$ isomers is proposed.