Solid state effects in binary-encounter electron emission from collisions with C, Al, Cu and Au foils

Abstract

We have studied binary-encounter electron ejection from thin solid foils (C, Al, Cu, Au) with highly charged swift heavy ions at both experimentally and theoretically. The theory, based on the electron impact approximation describes the shape and the angular dependence well for very thin targets only (for example C less than 260 Å). For thicker targets, solid state effects (in particular, electron transport) influence the shape of the binary-encounter electron peak initially given by the target atom Compton profile. Such effects have to be taken into account in atomic collision experiments even if single-collision conditions for the primary interaction (e.g. ionization) are fulfilled. Not only may the electronic structure be different for free atoms and atoms bound in solids, but also the observable spectra of, for example, electrons may be different from the primary ones due to transport effects in condensed matter.