Actinide Symmetric/Asymmetric Nucleon‐Induced Fission up to 200 MeV

The fission cross sections of the symmetric SL‐mode and the asymmetric lumped (S1+S2)‐mode of the ²³⁸U(n,F), ²³⁵U(n,F), ²³²Th(n,F), and ²³⁸U(p,F) reactions are calculated up to E_n=200 MeV within a statistical model. To reproduce the measured branching ratio of symmetric and asymmetric fission events in the ²³⁸U(n,F) reaction, a preferential contribution of fission from neutron‐deficient nuclei is assumed. This assumption is of critical importance to reproduce the observed ²³²Th(n,F) cross section. The branching ratio of symmetric and asymmetric fission events is shown to increase, with the increase of the incident neutron energy, faster for the higher fissility of the target nuclide.