Dynamic core-hole screening effects in the C-KVV Auger line shape of graphite

Evidence is presented for the presence of a ''shakedown'' satellite near threshold in the C-KVV Auger spectrum of graphite. Its origin is shown to be an electron in a relatively long-lived valence-core excitonic level (populated as a result of dynamic core-hole screening) which participates in the Auger decay. Modeling of the shakedown contribution considerably improves agreement in the threshold region between the experimental line shape and a simple one-electron model and represents the first report of Auger intensity resulting from this type of excitonic configuration.