Atomic oxygen erosion phenomena

Abstract

The surface textures resulting from directed atomic oxygen interaction with materials which produce fully volatile oxidation products are similar to those produced by more energetic physical sputter texturing. A Monte Carlo computational model has been developed which simulates both low Earth orbital energetic atomic oxygen attack as well as isotropic thermal energy plasma atomic oxygen interactions with materials with volatile oxides. The surface roughening predicted by the model agrees with experimental observations, indicating that surface texture develops under the simplest interaction assumptions and grows in a less than linear manner with atomic oxygen fluence. The more paraxial the atomic oxygen arrival is, the greater the surface roughness for the same atomic oxygen fluence. The detailed nature of the scattering interactions appears to play a negligible role hi the development of surface roughness.