In situ measuring facility for evaluating and performing accelerated degradation tests for thermal control coatings

A combined environment test facility was constructed providing a wide range of ultraviolet (UV) radiation, low energy proton irradiation, electron irradiation, neutral gas and volatile condensable material (VCM) for materials investigation in a clean, oil-free high vacuum. A xenon lamp equipped with appropriate filters and a hydrogen discharge lamp irradiate the samples, simulating the solar ultraviolet and visible light up to about 30 solar constants. The solar wind simulator consists of the electron ionization proton source, accelerator, ion separator, and beam current detector. The energy of the protons can be raised to 5keV and the proton flux by three orders of magnitude above the average densities in near-earth orbits. The diameter of the samples is 45mm, the temperature of the samples is controlled. The reflectance of the samples is measured in situ before and after exposure to combined UV and particle irradiation by a spectrophotometer up to wavelengths of 40μm. Furthermore the combined influences of VCM, UV, low energy protons and electrons on the thermal control coating degradation can be tested