The fraction of power reaching the collector of a truncated cylindrical compound parabolic concentrator, out of the total power arriving at its entry aperture in a given direction, is calculated without ray tracing for all directions.
© 1983 Optical Society of America
Juan Carlos Miñano, "Directional intercept factor of truncated CPCs," Appl. Opt. 22, 2747-2750 (1983)