Light emission from sputtered aluminum atoms and ions produced by ion bombardment

Photon emission originating from sputtering of a polycrystalline aluminum surface under 1-10 keV ion (H+, He+, Ar+, Kr+ and Xe+) bombardment has been studied. Measured photon emission yields from the 3d 2D3/2 resonance transition of sputtered excited Al atoms and calculated nuclear stopping powers are compared. The results demonstrate that elastic collisions play a major role in photon emission. Moreover, measurements of photon intensity as a function of the distance from the target surface show that decays of sputtered excited ions Al+ and Al2+ are faster than decays of excited Al atoms, and less affected by cascade repopulation and de-excitation of fast ions.