Ne20-induced reactions with Cu andAu197at 8.6 and 12.6 MeV/nucleon

Products from the reactions of 170- and 252-MeV ${}_{}{}^{20}{}_{}{}^{}\mathrm{Ne}$ with ${}_{}{}^{\mathrm{nat}}{}_{}{}^{}\mathrm{Cu}$ and ${}_{}{}^{197}{}_{}{}^{}\mathrm{Au}$ have been studied. The charge and angular distributions of the $Z$-identified fragments are discussed in terms of diffusion along the mass-asymmetry coordinate. This diffusion model has been generalized to include the effects of shape evolution, which is important for these deeply penetrating systems, and also the effect of $\frac{N}{Z}$ equilibration, which is important for highly asymmetric systems such as ${}_{}{}^{20}{}_{}{}^{}\mathrm{Ne}$ + ${}_{}{}^{197}{}_{}{}^{}\mathrm{Au}$.