Evolution of optical coatings in Earth orbit.
High-resolution medium-energy backscattering analyses have been performed on SiO and SiO(2) optical coatings that were exposed to the space environment aboard the NASA long-duration experiment module flight (LDEF). The data show an increase in areal density of 1% (resolved at the l0sigma level) in the SiO film as a result of this exposure. It appears that this effect has been produced by the incorporation of atomic oxygen from the ambient environment. Data on the SiO(2) film are less compelling but are consistent with some loss of material from the surface. These analyses set a new standard for profiling film thicknesses by ion backscattering.
M H
MH
Mendenhall
R A
RA
Weller
A F
AF
Whitaker