On mechanism of graphite high temperature erosion under ion irradiation

The character of the MPG-8 graphite surface decomposition at high temperature under the effect of irradiation by 20 keV He+ ions at current density of 0.4-0.5 μA/cm2 is investigated using the method of energy mass-spectrometry of secondary ions. At T=1000-1500 deg C graphite erosion is determined by the totality of two processes: 1) formation on the surface of chemisorbed carbon atoms both as a result of diffusion from the depth of the sample of carbon interstitial atoms produced by ion bombardment and surface diffusion; 2) desorption of the atoms of ion beam