Microscopic dynamical studies of the effects of the nuclear equation of state in intermediate-energy heavy ion collisions.

摘要

We study the role of the nuclear equation of state in intermediate-energy heavy-ion collisions using microscopic dynamical calculations. The relevant properties of the nuclear equation of state, and their manifestation in fragmentation reactions and Bevalac-energy collisions are reviewed. The available data on these collisions is summarized.;We discuss the use of the Vlasov-Nordheim equation in calculating heavy-ion collisions, and present a new method for solving the nuclear Vlasov equation with far greater accuracy than other existing methods. This method is used to study the role of the quantum Fermi motion is heavy-ion collisions.;We also study the accuracy of Vlasov-Nordheim theory in the classical limit (i.e., Vlasov-Boltzmann) by comparing its predictions with the exact results of a classical model of heavy-ion collisions. It is shown that, although the Vlasov-Boltzmann theory can reproduce the general trends, it fails to reproduce the correct values of several specific observables. In this limited study, we do not find that the theory is very useful for deducing that incompressibility of matter from collision data.;We calculate the disassembly of hot charged classical drops that have an equation of state similar to that of nuclear matter. It is found that the region of adiabatic instability of the liquid-vapor phase transition is responsible for the rapid fragmentation of hot systems. For cooler drops, we find that this unstable region causes large deformations in the droplet shape that are exploited by the Coulomb force, resulting in fast binary and multiple fission decay modes.