Stopping power for swift dressed ions

We present theoretical calculations of electronic stopping power, including excitation and loss of both projectile and target electrons. The energy loss due to target valence and inner-shell electrons are separately evaluated: the former in the usual dielectric formalism, and the latter by employing a shell-wise local plasma approximation. Stopping power calculations of He ions in Al and Zn are presented, including the electron-electron contribution mentioned above. The agreement with the experimental data is very good, and let us conclude that, for helium ions, projectile excitation and loss contribute to the stopping power at the most in 1%, and it is reasonable for the theoretical descriptions to neglect it.