Fine structure of the fragment yields in heavy nucleus fission

Relative cumulative yields of sup(131,132,134,136)Xe isotopes resulted from fission of 232Th, sup(235,238)U, 239Pu nuclei by 14 MeV neutrons and sup(235,238)U, 237Np,239Pu nuclei by bremsstrahlung gamma-quanta (15 and 20 MeV maximum electron energy) are measured by the mass-spectrometric method. The results obtained testify to the fine structure conservation with maximum at A=134 and at the excitation energy of nuclei under investigation up to approximately 21 MeV for all the nuclei except for 232Th. The analysis of the experimental results and literature data on low-energy neutron fission permits to elicit a dependence of a fine structure value (ratio of fragment yields with A=134/A=136 masses) on the number of neutrons in a compound nucleus