Experimental and theoretical high-energy fission studies

Temperature-dependent fission barriers and fission-fragment mass distributions are calculated in the framework of the multi-modal random-neck rupture model. It is shown how the distinction between the different fission modes disappears at higher excitation energies, due to the melting of the shell effects. The mass yield calculations are coupled to the nuclear reaction code ALICE-91, which takes into account the competition between the other reaction channels and fission. Results for 190 MeV proton-induced fission of W-nat, Au-197, Pb-208, and Th-232 are compared to recent measurements. Furthermore, neutron-induced fission of U-238 Up to 100 MeV is investigated.