Ion bombardment induced light emission

Energetic ions penetrating a solid lose their energy by inelastic electronic and elastic nuclear collision processes. The elastic collision results in sputtering of target atoms, while the inelastic part of the interaction may lead to emission of particles in an excited or ionized state. In this article, we consider mainly the sputtered excited particles that are short-lived (lifetimes < 10(-6) s) and decay radiatively away from the target surface. The various mechanisms of atomic excitation in sputtering are discussed. The experimental studies on secondary photon emission yields are briefly reviewed. Finally, the use of sputtering-induced optical emission as a sensitive tool for surface analysis is discussed.