Cumulative Fission Yield and Half-Life ofSb134

Abstract

The cumulative fission yield of ${}_{}{}^{134}{}_{}{}^{}\mathrm{Sb}$ produced in thermal-neutron-induced fission of ${}_{}{}^{235}{}_{}{}^{}\mathrm{U}$ has been experimentally determined, and the half-life of the nuclide has been measured. The cumulative fission yield and half-life are found to be (0.32±0.04)% and 11.1±0.8 sec, respectively. It is shown that the fission yields presently measured in the mass-134 chain do not fit a Gaussian isobaric yield curve and that this could be accounted for by isomerism in ${}_{}{}^{134}{}_{}{}^{}\mathrm{Sb}$. A nuclear level scheme for ${}_{}{}^{134}{}_{}{}^{}\mathrm{Sb}$ which predicts two isomeric states for this nuclide is presented. From the experimental data, an upper limit of approximately 2 sec is determined for the half-life of the proposed isomer.