Design And Optical Performance of Beryllium Assessment Mirrors

Beryllium mirrors, approximately 19.8 cm x 8.8 cm in size, were designed, procured, and evaluated. The mirrors are off-axis rectangular segments of an f/1 paraboloid. These segments, which are the primary mirrors in a Cassegrainian telescope design, are lightweighted and incorporate a stress-free mounting technique which minimizes post-assembly alignment. Upon delivery, the mirrors were characterized to determine their compliance with the figure, scatter, reflectance, and dimensional specifications.