Analysis of the fissility and fission barriers of preactinide nuclei

A statistical approach based on description of the density of excited levels in the superfluid model with phenomenological inclusion of collective and shell effects has been used to analyze an extensive set of experimental data on the fissility of nuclei with Z = 70--85 and A = 170--213 in reactions induced by light charged particles, including electrons, with energy up to 80 MeV. New experimental information on the fission-barrier heights E/sub tsf/ (Z, N) will require improvement of the isospin-dependence parameter in the contemporary description of the masses and the nuclear deformation energy