Electron emission by highly charged neon and xenon ions on fusion-relevant tungsten and graphite surfaces

Here we report highly charged 40Neq+ (q = 3–8) and 129Xeq+ (q = 10–30) ion-induced secondary electron emission on the tungsten and highly oriented pyrolytic graphite (HOPG) surfaces. The total secondary electron yield is measured as a function of the potential energy of incident ion. The experimental data is used to separate contributions of kinetic and potential electron yields. We estimate roughly 10% of ion’s potential energy is consumed in potential electron emission. The rest of the ion’s potential energy is responsible for the sputtering and material modification.