βdecay ofCa51

The new isotope ${}_{}{}^{51}{}_{}{}^{}\mathrm{Ca}$ has been observed in the decay of ${}_{}{}^{51}{}_{}{}^{}\mathrm{K}$ produced by fragmentation of a uranium target with 600-MeV protons. The half-life of ${}_{}{}^{51}{}_{}{}^{}\mathrm{Ca}$ was determined to be 10.0±0.8 s; the decay properties were established from $\gamma$-ray singles and coincidence measurements. The deexcitation scheme accounts for twenty-two $\gamma$ transitions between eleven levels in ${}_{}{}^{51}{}_{}{}^{}\mathrm{Sc}$. Two states, located at 3039 and 3195 keV, can be related to the excitation of the odd proton in the $2p$ $\frac{3}{2}$ orbital.