Discussions on radiation and space environment exposure of replicated optical mirrors produced from carbon composites

Radiation effects are well know to cause significant degradation in polymer materials. Low earth orbit (LEO) radiation exposures cause ionization potentials that can undermine mechanical properties of polymers. In particular, small scale degradations can undermine carbon / polymer composite mirrors used in imaging applications. High specularity surface finish is required for optical mirrors and that surface is vulnerable to radiation ionization degradation thereby undermining the optical performance of the mirror in that environment. Experiments involving radiation ionization and its effects on replicated carbon/polymer composite mirrors will be will be discussed; 6 replicated carbon/polymer composite mirrors on the Materials on the International Space Station Experiment, MISSE 7 and MISSE 8, the replicated RICH mirror the Alpha Magnetic Spectrometer (AMS-02) and testing on the RICH 1 replicated mirrors in the LHCb experiment. Results are favorable for optically coated composite mirrors in terms of mirror figure, reflectivity and surface finish, but no so on uncoated polymer mirrors.