Lowest 2 + State in Gd 82 64 146 and the Energy Gap at Z = 64

A search for the lowest ${2}^{+}$ state in $^{146}\mathrm{Gd}$ using ($\ensuremath{\alpha}$,$2n\ensuremath{\gamma}$) excitation function measurements near threshold has located that state at 1971 keV. Its energy, more that 300 keV higher than in any other $N=82$ nucleus, provides clear spectroscopic evidence for a large gap in the single-particle spectrum at $Z=64$.