Auger photoelectron coincidence spectroscopy of the 2p1/2 line in coincidence with the L3-M45M45 peak of copper

As new surface analytical equipment becomes available, it is increasingly important to understand the physics behind the small satellites and features in electron spectra. Auger photoelectron coincidence spectroscopy (APECS) has been used to study the 2p1/2 photoelectron line (electrons from the L2 level) of copper in coincidence with the L3-M4,5M4,5Auger peak. The intensity in coincidence in the L3-M4,5M4,5 peak is due to a Coster–Kronig transition, L2-L3-M4,5M4,5(M4,5). We have found that there is a shift in the position of the photoelectron line when the Auger analyser is fixed at different positions in the low kinetic energy tail of the Auger peak. This is an unusual effect, which we attribute to an electrostatic interaction between the outgoing electrons, in a form of post-collisional interaction