The new $\beta$-delayed proton precursor ${}^{121}$Ce was synthesized in the reaction ${}^{92}$Mo${(}^{32}$S,$3n)$ and first identified in $p$-$\gamma \mathrm{}\left(X\right)\mathrm{}$ coincidence measurements with a helium-jet recoil fast-moving tape-transport system. The half-life of the ${}^{121}$Ce decay was determined to be 1.1$\pm$0.1 s. Its $\beta$-delayed proton spectrum was observed and the $\beta$-delayed proton branching ratio for ${}^{121}$Ce decay was estimated to be $\sim$1%.

• Received 3 February 1997

DOI:https://doi.org/10.1103/PhysRevC.56.1157