Current status of chemical sputtering of graphite and related materials

Matsunami, Noriaki*; Nakano, Tomohide

Graphite and graphite-based materials are candidates for plasma-facing components in fusion devices, because of low atomic number (low erosion rate), high performance in mechanical property and thermal conductivity. A drawback of graphite is that the erosion (or sputtering) yield goes up to 0.1 C/H, in comparing with the maximum physical sputtering yield of 0.01, when graphite at elevated temperature of several hundred K is bombarded with energetic hydrogen or deuterium ions. This is known as chemical sputtering and originates from formation of hydro-carbons and easy release of them from the graphite. The current status of the chemical sputtering of graphite will be presented.