From Dissipative Collisions to Multiple Fragment Production — A Unified View

Abstract

Over the last decade, much of the effort in intermediate-energy heavy-ion reaction studies has been focused on multifragmentation, [1, 2, 3, 4] a phenomenon leading to multiple intermediate-mass fragments (IMF) in the reaction exit channel. Since the standard statistical model appeared to be unable to account for the large observed IMF multiplicities, various models and scenarios have been proposed [5, 6, 7], which favor copious production of IMFs. On the other hand, in several recent studies [8, 9, 10], it was found that even in the Fermi energy domain, the binary dissipative collision scenario, well established at lower bombarding energies,[11] still accounts for most of the reaction cross section. The present paper shows that, like dissipative collisions, multiple-IMF emission is a dynamical process, driven by the kinetic energy of relative motion of projectile- and target-like fragments. A new, more complete, intermediate-energy heavy-ion reaction scenario is proposed that connects in a natural way the domains of dissipative collisions and multiple IMF production.