Dynamical screening in Auger processes near metal surfaces

We develop a theory for Auger processes occurring when a slow ion interacts with a metal surface that includes dynamical screening. In particular, the theory contains the possibility that normal modes of the electron gas are excited in the Auger process. We perform a calculation of the Auger capture rate for a model system representing ${\mathrm{He}}^{+}$ interacting with an Al surface and show that surface plasmons are indeed excited in this system. We also show that the inclusion of screening affects the exponential decrease of the Auger rate with increasing distance between ion and surface.