18 July 1988 Interferometric Phase Measurement Of Zerodur, Aluminum And SXA Mirrors At Cryogenic Temperatures
Author Affiliations +
Abstract
A research program was undertaken to determine the surface figure error of several different types of mirrors at cryogenic temperatures. Two-inch diameter parabolic, spherical and flat mirrors were fabricated from zerodur, aluminum and a metal matrix composite of silicon carbide reinforced alumi-num (SXA). The ratio of silicon carbide to aluminum was selected so that the cofficient of thermal expansion (CTE) of the metal matrix matched electroless nickel. A liquid helium dewar was modified to add an interferometric grade window, a cold electronic shutter and a strain-free copper mirror mount. Interferometric phase measurements on each mirror mounted in the dewar were made without the window, with the window, under vacuum, at around 80K and between 10K and 24K.
© (1988) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Thomas J Magner, Thomas J Magner, Richard D Barney, Richard D Barney, } "Interferometric Phase Measurement Of Zerodur, Aluminum And SXA Mirrors At Cryogenic Temperatures", Proc. SPIE 0929, Infrared Optical Materials IV, (18 July 1988); doi: 10.1117/12.945848; https://doi.org/10.1117/12.945848
PROCEEDINGS
10 PAGES


SHARE
RELATED CONTENT

SIRTF telescope test facility
Proceedings of SPIE (September 28 1995)
IRAS Telescope Cryotest Chamber
Proceedings of SPIE (January 31 1985)
The mechanics and cryogenics of GIANO-TNG
Proceedings of SPIE (June 28 2006)

Back to Top