Variation of total kinetic energy and mass distributions in the fusion-fission reaction of ~(16)O, ~(19)F + ~(209)Bi at near barrier energies

摘要

Fission fragment mass and energy distributions and their correlations have been measured for the ~(16)O and ~(19)F + ~(209)Bi reactions over a wide range of excitation energies (E~* = 30-50 MeV). It is observed that in the case of ~(16)O + ~(209)Bi reaction, the average total fragment kinetic energy, is nearly independent of the bombarding energy. However, in the case of ~(19)F + ~(209)Bi reaction, the average total kinetic energy of the fission fragments shows a peaking behaviour near the barrier. The variation in at near barrier energies in the ~(19)F + ~(209)Bi system seems to be correlated with corresponding strong variation in the variance of the fragment mass distribution. The present results may imply certain dynamical effects leading to compact scission configurations in the fission of ~(19)F + ~(209)Bi system at near barrier bombarding energies.