Observation of the neutralization of highly charged ions interacting with a metal surface

We report the first measurements of ejected-electron-energy distributions from slow glancing collisions of highly charged ions having K-shell vacancies with a solid surface. The spectra indicate two competing processes for filling the vacancy: one involving normal atomic Auger decay, and the other, vacancy transfer to inner shells of the solid via molecular orbital pseudocrossings. The number of electrons per incident ion resulting from the filling of the K-shell vacancy is of the order of unity, constituting only a small fraction of the total measured yield.