Isospin diffusion inNi58-induced reactions at intermediate energies. II. Dynamical simulations

Abstract

We study isospin effects in semiperipheral collisions above the Fermi energy by considering the symmetric $^{58}\mathrm{Ni}+^{58}\mathrm{Ni}$ and the asymmetric $^{58}\mathrm{Ni}+^{197}\mathrm{Au}$ reactions over the incident energy range $52A\text{\ensuremath{-}}74A$ MeV. A microscopic transport model with two different parametrizations of the symmetry energy term is used to investigate the isotopic content of pre-equilibrium emission and the $N/Z$ diffusion process. Simulations are also compared to experimental data obtained with the INDRA array and provide information on the degree of isospin equilibration observed in $\mathrm{Ni}+\mathrm{Au}$ collisions. A better overall agreement between data and simulations is obtained when using a symmetry term that linearly increases with nuclear density.