Post-collision interaction in the photoexcited electron spectrum of selenium

Evidence for a post-collision interaction (PCI) in the photoelectron spectrum of the selenium 2p/sub 3/2/ level is reported. The Auger lines corresponding to the decay of the deep lying Se 2p core holes are also shown to be affected by PCI. The Se 2p/sub 3/2/ photo-electron and Auger line-shapes are well described by the semi-classical PCI energy distribution derived from the 'shake-down' model. Furthermore, the nominal Se 2p spin orbit splitting is determined to 40.81(5) eV