Material dependence of total electron emission yields following slow highly charged ion impact

The total electron emission yields following the interaction of “Slow (⩽2 keV/a.u.) Highly Charged Ions” (SHCI) (O3+⋯7+, Xe12+⋯52+, Au54+⋯69+) with different target surfaces (highly-oriented pyrolytic graphite (HOPG), Au and SiO2) have been measured. The emission yields increase with charge state, and is found to be highest for carbon, the HOPG target, and lowest for the SiO2 target. An empirical formula for the electron emission is including recent results from investigations of plasmon excitation following SHCI impact are used to interpret the results.