Comparison of fission of heavy nuclei induced by different probes

The fission induced in heavy nuclei ($Z^2$/A>30) by photons, pions, and protons of intermediate energy was studied. The fissilities were deduced from measured fission cross sections using the total reaction cross sections specific for each probe. The energies of the projectiles were chosen in such a way to produce similar configurations of the residual compound nuclei: to this end an intranuclear-cascade model was employed. With this choice, the obtained fissilities, plotted as a function of the 〈$Z_{\mathrm{cn}{}^2\mathrm{〉}/\mathrm{〈}{A}_{\mathrm{cn}\mathrm{〉}}}$ of the compound nuclei formed, are found in nice agreement irrespective of the probe used, and also in agreement with the fissilities calculated with the cascade-evaporation model based on the two-step picture of the process.