INFLUENCE OF EXPERIMENTAL RESOLUTION AND BACKGROUND UPON ION-INDUCED UPSILON-E CONGRUENT-TO UPSILON-I ELECTRON DISTRIBUTIONS MEASURED BEHIND SOLID FOILS

Some confusion has developed with regard to the correct procedure necessary to compare charge exchange to the continuum (CEC) theories and experiment for ion-beam-foil collisions where the emitted electrons have velocities v e approximately=vi. In order to make such a comparison, the authors emphasise that (a) the instrumental resolutions in angle and absolute value of velocity must be folded into the theoretical double differential cross section, and (b) that if the emission of CEC electrons occurs only because of interaction with the outermost atomic layers, those electrons originating from further inside the foil must be subtracted as background. Unfortunately, these considerations were not properly accounted for by Steckelmacher and colleagues (1978), as they compared their recent results with theory and published experiments.