Excitation energy partition in deeply inelastic collisions between 40Ar and Ag at 27 MeV per nucleon

The dynamics of the two partners produced in dissipative collisions has been experimentally studied for the system 40Ar+Ag at 27 MeV per nucleon. Primary masses of the fragments can then be calculated; the excitation energy partition between the two fragments is derived from the number of particles evaporated by each fragment. We found that this division evolves from equipartition to a repartition close to thermal equilibrium in the excitation energy range 300-350 MeV or interaction times 5-10x10-22 s. (orig.)