Fast-Neutron Bombardment ofNi64and the Decay ofFe61

A 6.15±0.06-min activity, which has been assigned to the decay of ${\mathrm{Fe}}^{61}$, has been produced as the result of bombardment of nickel enriched in ${\mathrm{Ni}}^{64}$ with 15-19-MeV neutrons. The decay scheme has been studied by $\beta$, $\gamma$, $\beta -\gamma$, and $\gamma -\gamma$ counting techniques using plastic scintillators, NaI(Tl) crystals, and a Ge(Li) detector. Evidence was found for levels in ${\mathrm{Co}}^{61}$ at 1.028±0.005, 1.206±0.005, 1.327±0.005, 1.650±0.015, and 1.995±0.020 MeV.