Isomeric yield ratios of I-134 and I-136 in the proton-, C-12- and F-19-induced fission of U-235, Np-237 and U-238

摘要

Short-lived nuclides of iodine produced in the proton-, C-12- and F-19-induced fission of U-235, Np-237 and U-238 were separated with a rapid chemical separation system SISAK. Relative yields of the nuclides were determined by gamma-ray spectrometry to obtain the isomeric yield ratios of I-134m/ I-134g and I-136m/I-136g. Angular momenta of the fission fragments, I-134 and I-136, were derived from the measured isomeric yield ratios by the spin-dependent statistical model. In the light- and heavy-ion fission, variation of the observed angular momenta can be explained by the excitation energies of the fissioning nuclei and the spherical shell structure with N = 82. [References: 21]