Dynamical Fragment Production as a Mode of Energy Dissipation in Heavy-Ion Reactions

Based on measured correlations between experimental observables in the ²⁰⁹Bi+¹³⁶Xe reaction at E/A0ex0ex=0ex0ex280ex0exMeV, it is shown that multiple intermediate-mass fragment (IMF) production is a dynamical process driven by the energy of relative motion of projectilelike and targetlike fragments. This kinetic energy is converted into thermal energy of the system, until a certain ``saturation'' value of approximately 3 MeV/nucleon is reached. From this point on, this ``conventional'' dissipation mechanism is replaced by dynamical IMF production, constituting a new mode of energy dissipation.