Scission Configurations for StI and StII Fission Modes in the Reaction 235U(nth, f)

Two scission configurations that can explain the fission fragment properties of the principal fission modes, short (StI) and standard (StII), in the reaction 235U(nth, f) are presented. These configurations are very close to the optimal scission shapes defined with three constraints: on fragment elongation, mass asymmetry and neck radius. They are subsequently approximated by the modified Cassini ovals in order to calculate fission fragment properties such as mass yields, excitation energies of individual fragments and total kinetic energies. For each configuration a comparison is made with the same quantities obtained from experimental data after decomposition into contributions from three fission modes.