Energy loss of slow, highly charged ions in solids

The loss of kinetic energy of highly charged, heavy ions (${\mathrm{Ar}}^{18+},$ ${\mathrm{Xe}}^{44+},$ and ${\mathrm{Au}}^{69+}$) in thin carbon foils has been measured as a function projectile velocity in the range from $6\times {10}^5$ to $11\times {10}^5\mathrm{m}/\mathrm{s}.$ Evidence for strong pre-equilibrium energy-loss enhancements is observed for highly charged xenon and gold ions.