Potential and Kinetic Electron Emissions from HOPG Surface Irradiated by Highly Charged Xenon and Neon Ions

Highly charged ¹²⁹Xe^q+ (q=10–30) and ⁴⁰Ne^q+ (q=4–8) ion−induced secondary electron emissions on the surface of highly oriented pyrolytic graphite (HOPG) are reported. The total secondary electron yield is measured as a function of the potential energy of incident ions. The experimental data are used to separate contributions of kinetic and potential electron yields. Our results show that about 4.5% and 13.2% of ion's potential energies are consumed in potential electron emission due to different Xe^q+−HOPG and Ne^q+-HOPG combinations. A simple formula is introduced to estimate the fraction of ion's potential energy for potential electron emission.