A Method for Calculating Thermal Radiation Properties of Multilayer Films from Optical Constants

A calculation method for the incident angle dependence of the solar absorptance as and the temperature dependence of the total hemispherical emittance EH of multilayer films is proposed. The method is based on calculation of xs and £H from optical constants in the wavelength region from 0.25 to 100 um for thin polymer films and deposited metal. In this paper we provide values of as in the incident angle region from 0 to 90° and % in the temperature range from 173.15 to 373.15 K. for two-layer samples of aluminum-deposited polyimide film. The results obtained for as and £H by the present method are compared with experimental results measured by both spectroscopic and calorimetric methods. The calculated results of as and £H agree well with the experimental results