The neutron-rich isotope ${}_{}{}^{62}{}_{}{}^{}\mathrm{Fe}$ was discovered in a ${}_{}{}^{64}{}_{}{}^{}\mathrm{Ni}$ metal foil irradiated in a new medium energy intense neutron beam at the Brookhaven 200-MeV linac. A flux in the energy range 25-200 MeV of ∼ 1.3 × ${10}^{11}$ n/${\mathrm{cm}}^2$ sec is obtained on target at this unique facility. The ${}_{}{}^{62}{}_{}{}^{}\mathrm{Fe}$ decays with a half-life of 68 ± 2 sec primarily by emission of 2.5-MeV $\beta$ rays to a $J^{\pi }=1^{+}$ level in ${}_{}{}^{62}{}_{}{}^{}\mathrm{Co}$ at 506.1 ± 0.1 keV.

RADIOACTIVITY ${}_{}{}^{62}{}_{}{}^{}\mathrm{Fe}$; measured $T_{\frac{1}{2}}$, $E_{\beta }$, $\beta \gamma$ coin; deduced $log\mathrm{ft}$ $Q$. ${}_{}{}^{62}{}_{}{}^{}\mathrm{Co}$; measured $E_{\gamma }$, $I_{\gamma }$; deduced levels $J$, $\pi$. Used medium energy intense neutron beam for ${}_{}{}^{64}{}_{}{}^{}\mathrm{Ni}(n, 2pn)$.

• Received 9 April 1975

DOI:https://doi.org/10.1103/PhysRevC.12.616