The $\beta$-delayed proton precursor ${}^{121}\mathrm{Ce}$ has been produced via the ${}^{92}\mathrm{Mo}{(}^{32}\mathrm{S},\mathrm{}3{n)}^{121}\mathrm{Ce}$ reaction and studied by using a He-jet tape transport system. The $\beta$-delayed proton spectrum populating the low-lying excited states in ${}^{120}\mathrm{Ba}$ was obtained, and the relative ratio of the proton branchs feeding the first and second excited states in ${}^{120}\mathrm{Ba}$ was measured to be 100:19. By using statistical model calculations the spin and parity for the ground state of ${}^{121}\mathrm{Ce}$ have been assigned to be ${5/2}^{+}$ or ${5/2}^{-}.$

• Received 26 May 1999

DOI:https://doi.org/10.1103/PhysRevC.60.067304