Identification of mechanisms of ion induced electron emission by factor analysis

Introducing the use of the Factor Analysis method to analyze electron emission spectra we identify different mechanisms for electron emission from clean Al surfaces under bombardment by Ar+ and Li+ ions. The analysis of the energy electron emission distributions and their dependence on incoming ion energy allows separation of the direct contribution of Auger neutralization from that of plasmon de-excitation and cascade electrons due to kinetic emission. Similarly, the analysis shows that, under our experimental conditions, plasmons are excited by fast Al-2p Auger electrons produced in symmetric Al-Al encounters in the atomic collision cascades initiated by the projectiles.