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 Sb134m,134 yield ratio had not been previously measured in the spontaneous fission of Cf252; however, it had previously been observed to favor the (7-) isomer over the (0-) ground state in U235(nth,f) and Th232(25 MeV p,f). Using a mass-separated beam of low-energy Sb134,134m ions produced by Cf252 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 Sb134m to Sb134 fission yield was determined to be 2.03±0.05 and the half-lives of Sb134m and Sb134 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 Sb134 ground state and the Sb134m isomer half-lives.
Publication Source (Journal or Book title)
Physical Review C
Siegl, K., Kolos, K., Scielzo, N., Aprahamian, A., Savard, G., Burkey, M., Carpenter, M., Chowdhury, P., Clark, J., Copp, P., Lane, G., Lister, C., Marley, S., McCutchan, E., Mitchell, A., Rohrer, J., Smith, M., & Zhu, S. (2018). β -decay half-lives of Sb 134,134m and their isomeric yield ratio produced by the spontaneous fission of Cf 252. Physical Review C, 98 (5) https://doi.org/10.1103/PhysRevC.98.054307