Neutralization of hyperthermal Ne+ on metal surfaces

Relative ion yields of low energy (320 eV) Ne+ ions scattered off a number of elemental surfaces are compared. Ion survival probabilities are seen to change significantly from one element to another depending on the surface work function, suggesting that resonant charge exchange between the metal conduction band and Ne 3s atomic level may be just as important as Auger neutralization processes. The observed yield dependence on work function is qualitatively explained using a description of resonant neutralization (RN) based on the Anderson model of an atomic level near a surface. Auger processes are found to be important in determining the final charge state of outgoing ions, while quasi-resonant interactions between the core atomic levels are seen to be nonexistent.