MD Study on Carbon Sputtering and Redeposition

Abstract

In order to estimate the erosion of accelerator grids of an ion engine, the low-energy sputtering of carbon material under Xe ion bombardment and the redeposition of low-energy sputtered particles on the carbon material are studied through the molecular dynamics (MD) simulation. For the normal incidence of Xe, the MD result of sputtering yield almost agrees with the experimental result by Williams et al. (AIAA-2004-3788). However, the experimental result shows less incident angle dependence than the MD result because it performed on a rough surface. For the redeposition on amorphous carbon (a-C) surface, the reflection and the deep trapping are suppressed. The mean deposition rate with deposition energy up to 100 eV is 0.82∼0.75 taking account of incident angle distributions.