Photoelectron recapture through post-collision interaction

Abstract
In inner-shell photoionization of an atom followed by Auger decay, the Auger electron initially screens the ionic Coulomb field experienced by the photoelectron. A sudden change in screening occurs when the Auger electron overtakes the photoelectron, causing energy transfer from the latter to the former. According to both semiclassical and quantum theories of post-collision interaction, the photoelectron can thus be recaptured by the atom from which it was emitted. This phenomenon has been measured directly with synchrotron radiation, as a function of incident-photon energy, and is found to be in accord with predictions.