beta-decay half-lives of Sb-134,Sb-134m and their isomeric yield ratio produced by the spontaneous fission of Cf-252

A number of fission products possess isomeric states which have a nuclear spin significantly different from that of the ground state. The yield ratio of these states following fission is influenced by the angular momentum present in the fissioning system. The (134m,134)sb yield ratio had not been previously measured in the spontaneous fission of Cf-252; however, it had previously been observed to favor the (7(-)) isomer over the (0(-)) ground state in U-235(n(th), f) and Th-232(25 MeV p, f). Using a mass-separated beam of low-energy Sb-134,Sb-134m ions produced by Cf-252 spontaneous fission at the CARIBU facility, beta particles and gamma rays were detected using the SATURN/X-Array decay station to determine the fission-yield ratio and beta-decay half-lives. The Sb-134m to Sb-134 fission yield was determined to be 2.03 +/- 0.05 and the half-lives of Sb-134m and Sb-134 were found to be 9.87 +/- 0.08 s and 0.674 +/- 0.004 s, respectively. These results represent the first isomeric yield ratio measurement for this nucleus, and improved measurements of the Sb-134 ground state and the Sb-134m isomer half-lives.