The experimental cryogenic performance of 160-mm-diameter silicon carbide (SiC) mirrors, one of which, a 700-mm-diameter mirror, is to be used as a primary mirror of the Japanese Infrared Astronomical Satellite ASTRO-F, is described. The mirrors are made from a sandwich-type SiC material that comprises a light porous core and a dense chemical-vapor-deposited coat of SiC. Three mirrors were manufactured consecutively, and changes in their surface contours related to temperature were measured with an interferometer when the mirrors were placed in a liquid-helium cryostat. Owing to significant improvements in manufacturing, the third SiC mirror showed only slight deformation as the temperature decreased from 300 to 6 K, which indicates high thermal strain homogeneity for a well-controlled sandwich-type SiC mirror.
© 2003 Optical Society of AmericaFull Article | PDF Article
Takashi Onaka, Toyoji Yagi, Hiroshi Shibai, Hiroshi Murakami, Toshihiko Tanabè, and Tsuguo Kohno
Appl. Opt. 33(10) 1880-1888 (1994)
Hidehiro Kaneda, Takashi Onaka, Takao Nakagawa, Keigo Enya, Hiroshi Murakami, Ryoji Yamashiro, Tatsuhiko Ezaki, Yasuyuki Numao, and Yoshikazu Sugiyama
Appl. Opt. 44(32) 6823-6832 (2005)
Keigo Enya, Takao Nakagawa, Hidehiro Kaneda, Takashi Onaka, Tuyoshi Ozaki, and Masami Kume
Appl. Opt. 46(11) 2049-2056 (2007)