B-decay half-lives of ¹³⁴ ̓ ¹³⁴ᴹSb and their isomeric yield ratio produced by the spontaneous fission of ²⁵²Cf

Abstract

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,134Sb yield ratio had not been previously measured in the spontaneous fission of 252Cf; however, it had previously been observed to favor the (7−) isomer over the (0−) ground state in 235 U (nth,f) and 232 Th (25 MeV p,f). Using a mass-separated beam of low-energy 134, 134m Sb ions produced by 252 Cf spontaneous fission at the CARIBU facility, β particles and γ rays were detected using the SATURN/X-Array decay station to determine the fission-yield ratio and β-decay half-lives. The 134m Sb to 134Sb fission yield was determined to be 2.03 ±0.05 and the half-lives of 134m Sb and 134Sb were found to be 9.87±0.08s and 0.674±0.004s, respectively. These results represent the first isomeric yield ratio measurement for this nucleus, and improved measurements of the 134 Sb ground state and the 134m Sb isomer half-lives. Show more