Analysis of secondary-electron emission in beam-foil experiments with molecular ions

Abstract

We analyze the possibility of large oscillatory wake effects in secondary-electron emission induced by molecular ions, which were proposed in previous interpretations of results derived from beam-foil experiments. We show that theoretical expectations are in disagreement with the description of such oscillatory effects in terms of wake phenomena. Our analysis of various experimental evidences suggests a different origin for the effect. We propose a simple explanation for the molecular effect in secondary-electron emission, which is based on previous knowledge of electron emission from solid targets, and of molecular effects in the energy loss of ion clusters in solid foils.