Computational Techniques For Raytracing And Tolerancing Solar Collectors

Abstract

This paper describes the software that has been developed at Itek for the analysis and tolerancing of solar concentrator optical systems. The software models the conventional as well as the non-imaging components used in high energy solar concentrators. The system model includes an extended solar source, a segmented primary collector, a secondary non-imaging concentrator and a hemispherical receiving surface. Both surface irregularities and alignment of the primary segments are modeled as localized slope perturbations which deviate the surface normal where the geometrical ray intersects the surface. The non-imaging secondary concentrator is input as a single optical surface and a special raytrace code developed such that a ray may have any number of reflections up to a user specified maximum number in transmission through the secondary concentrator. Graphical results are included to illustrate the use of these new codes in analyzing systems with both conventional and non-imaging components. The raytrace procedures developed for the non-imaging secondary concentrator have been used at Itek to analyze grazing incidence x-ray telescope systems. The not obvious connection between codes developed for solar concentrators and their application to x-ray telescopes is explained in this paper.