Distortion of lineshape and angular distribution of Ar L3(-)M23M23 Auger electrons by post-collision interaction following electron impact ionization

Abstract

The post-collision interaction (PCI) is investigated in Auger processes induced by electron impact ionization. (An Auger decay of an inner vacancy results in the creation of four charged particles in the final state of such a process.) General formulae allowing for PCI are obtained for energy and angular distributions of the Auger electrons. The expressions obtained beyond the eikonal approximation describe the Auger spectra measured in coincidence and non-coincidence experiments. Results of our approach are applied to the case of the Ar L3-M23M23 Auger spectrum following electron impact ionization. The calculations show the essential PCI distortion of the lineshape and the angular distribution in coincidence measurements; in non-coincidence experiments only the lineshape is disturbed, not the angular distribution. Our results do not show the low-energy structure of the Auger line measured in coincidence with the scattered electrons.