Fragmentation in central Pb+Au collisions within a microscopic dynamic approach

The prompt fragmentation of a very massive nuclear system obtained in heavy-ion collisions at intermediate energies is studied in the framework of the semi-classical Landau-Vlasov model taking into account the two-body residual interactions and the isospin dependence. In a first phase, compression and expansion take place. In a second stage, the strong Coulomb repulsion and asymmetry neutron-proton lead to the formation of an evanescent bubble-like configuration which decays rapidly into several fragments. Time evolution of the densities and energy components as well as dependence on the beam energy are particularly analyzed. Quantitative comparisons are made with experimental data obtained in the 208Pb (29 MeV/u)+197Au reaction. (author). 28 refs., 11 figs