Photodegradation Effects in Materials Exposed to High Flux Solar and Solar Simulated Radiation

This report contains study results about photodegradation effects in materials exposed to high flux solar and solar simulated radiation. The studies show that high flux photoirradiation of materials can result in significant changes in the stability of materials. Photodesotption and photo-enhanced oxidation were determined to be the major mechanisms. These mechanisms were shown to affect, inextremely adverse ways, the expected thermal stability of solar relevant materials, especially stainless steels. (It is expected that related high temperature alloy steels will be similarly affected.) An analytical expression was generated to predict the flux behavior of the steels using #304 as a prototypical stainless steel system.