Photometric model of radiation (solar, light) concentration in optical media

Abstract

This paper considers features of concentration for the case when a concentrator system and source are in a medium with the refractive index n greater than 1. It is shown that, in the case of concentration in the focus the concentration field, the source can be characterized with an angular radius equal to the angular aperture of the concentrator U. It was found that the concentration in the medium significantly differs from the concentration in the air, and that it also depends on the shape of the radiation source (flat, volume). The photometric model and PC program take into account features of the concentration in the medium with n > 1. On the basis of numerical studies, it is shown that: for a spherical radiation source, the concentration in the air and in the medium will always be the same (this follows from the condition of energy conservation); for a flat source, the concentration in the medium up to some apertures U is constant and then becomes greater than the concentration in the air by n2 times.