Vol. 10, Issue 4, pp. 311-320 (1980)

Abstract

A theoretical analysis is given here for a directional selective cover for solar energy concentrators. The cover limits the radiation exchange to within definite solid angle and suppresses the large angle emission radiation. The emission solid angle is determined by the refractive index of the cover in the infrared region n(i). At n(i)≥2.613, which is realized by several non-oxid chalcogenide glasses, the emission solid angle can be reduced to zero, and thus there will be total suppression of infrared radiation. Considerable amplification of the concentration ratio is still attainable with refractive indices characteristic of ordinary optical glasses.