Freeze-out properties of multifragmentation events

Abstract : Freeze-out properties of multifragmentation events produced in central 129Xe+natSn collisions at different beam energies (32, 39, 45 and 50 AMeV) were estimated by means of a simulation based on the experimental data collected by the 4π INDRA multidetector. A rapid increase (between 32 and 45 AMeV) of the fraction of particles emitted at freeze-out is deduced. The existence of a limitation of excitation energy for fragments around 3.0-3.5 AMeV is confirmed. A comparison with the results of a microcanonical statistical model is also performed to verify the overall physical coherence of the present approach.