Systematic study of actinide and pre-actinide fission modes

Abstract

In this work, we present new experimental data on mass distribution of fission fragments from 241 Am proton-induced fission at 660 MeV measured at the LNR Phasotron (JINR). The systematic analysis of several measured fragment mass distributions from different fission reactions available in the literature is also presented. The proton-induced fission of 241 Am, 237 Np and 238 U at 26.5, 62.9 and 660 MeV was studied. The proton-induced fission of 232 Th was studied at 26.5, 62.9 and 190 MeV. The fission of 208 Pb also by a proton was investigated at 190, 500 and 1000 MeV. The fission of 197 Au was studied for 190 and 800 MeV protons. Bremsstrahlung reactions with maximum photon energies of 50 and 3500 MeV were studied for 232 Th and 238 U. The framework of the Random Neck Rupture Model was applied in the analysis. The roles of the neutron excess and of the so called fissility parameter were also investigated.