Effects of electron irradiation energy on optical properties of Kapton/Al thermal control coatings

The effects of energy and flux of electrons on Kapton/Al thermal control coatings were investigated. The spectral reflectance before and after irradiations of electrons was insitu measured. Experimental results show that the spectral reflectivity of Kapton/Al coatings was apparently degraded in the 300~1 200nm wavelength range of solar electromagnetic rays after electron irradiation. Under the exposure to electrons, no charging effects were found on the surface of Kapton films as an ioninduced conducting polymer. After electron irradiation, an “annealing” or “bleaching” effect occurred on the Kapton/Al coatings. For a given irradiation flux, the increment in solar absorptance of Kapton/Al coatings increased with electron energy. The relation of the increment in solar absorptance of