Sputtering yield of carbon-carbon composite due to xenon ion bombardment in ion engines

Abstract

The angular and energy dependence of the sputtering yield of a carbon-carbon composite due to xenon ion bombardment was investigated. Instead of assuming surfaces to be flat, a simple carbon fiber distribution model was introduced to account for the carbon-carbon composite surface structure observed using a scanning electron microscope. Yamamura's semi-empirical sputtering formula, which accounted for 14% xenon adsorption, was used to calculate the sputtering yield of the carbon fiber surface. The proposed model provided fairly good estimates of the angular and energy dependence of the sputtering yield for the carbon-carbon composite. A comparative analysis of sputtering yield models demonstrated that the proposed model most accurately predicted both the accelerator and decelerator grid mass changes in the μ 10 PM ion engine endurance test. In this paper, we present sputtering yield data over a range of xenon incidence energies from 0 to 2 keV and angles of incidence from 0 (normal incidence) to 90°.