Ternary events measured with CR-39 in the reaction at 15 MeV/nucleon

摘要: Abstract We report the study of reaction 15 MeV/nucleon 238 U + 197 Au , in which up to 7 final heavy fragments have been detected, using a CR-39 plastic nuclear track detector. The measured multiplicity distributions indicate that binary fission one (U-like) or both (U-like and Au-like) primary products clearly dominates for peripheral intermediate impact parameters exhausting more than 80% total cross section. Multifragment emission sets most central collisions. Reactions with 3 fragments, accounting half section, analysed event-by-event after measuring geometrical each detected track, assuming momentum conservation empirical range-energy-charged curves. Most these ternary processes originate two-step mechanism: initial projectile-target interaction plus deep-inelastic process followed by subsequent fission-like decay (mainly quasiprojectile). Indeed, relative velocity between two fastest are peaked at values close Viola systematics very-heavy nucleus.