Isotopic distributions in deep inelastic reactions induced by heavy ions and the relaxation of the neutron excess degree of freedom

The available experimental results on the equilibrium of the $\frac{N}{Z}$ degree of freedom are recalled. New available experimental results for very asymmetric systems are presented and compared to a simple classical model including the mass diffusion, the relaxation of the neutron excess degree of freedom, and the subsequent evaporation. The agreement between this classical calculation and the experiment is shown to be satisfactory.