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

R. T. de Souza Department of Chemistry and Indiana University Cyclotron Facility, Indiana University, Bloomington, Indiana 47405 (Received 15 March 1996) Based on measured correlations between experimental observables in the 209Bi 1 136Xe reaction at EyA ­ 28 MeV, 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 MeVynucleon is reached. From this point on, this “conventional” dissipation mechanism is replaced by dynamical IMF production, constituting a new mode of energy dissipation. [S0031-9007(96)01493-7]