title: Ideal second stages in tandem with parabolic concentrators.
abstract: Expressions for the concentration capability of parabolic reflectors are derived and extended to include additional ideal second-stage concentration. The ultimate concentration of a parabolic reflector (primary) alone is shown to achieve one-half of the ideal limit in 2-D geometry; the respective two-stage configuration is shown to approach the ideal limit itself at large f/Nos.
authors.forename: E M
authors.initials: EM
authors.lastname: Kritchman