18 July 2014 ZERODUR TAILORED for cryogenic application
Author Affiliations +
ZERODUR® glass ceramic from SCHOTT is known for its very low thermal expansion coefficient (CTE) at room temperature and its excellent CTE homogeneity. It is widely used for ground-based astronomical mirrors but also for satellite applications. Many reference application demonstrate the excellent and long lasting performance of ZERODUR® components in orbit. For space application a low CTE of the mirror material is required at cryogenic temperatures together with a good match of the thermal expansion to the supporting structure material. It is possible to optimize the coefficient of thermal expansion of ZERODUR® for cryogenic applications. This paper reports on measurements of thermal expansion of ZERODUR® down to cryogenic temperatures of 10 K performed by the PTB (Physikalisch Technische Bundesanstallt, Braunschweig, Germany, the national metrology laboratory). The ZERODUR® TAILORED CRYO presented in this paper has a very low coefficient of thermal expansion down to 70 K. The maximum absolute integrated thermal expansion down to 10 K is only about 20 ppm. Mirror blanks made from ZERODUR® TAILORED CRYO can be light weighted to almost 90% with our modern processing technologies. With ZERODUR® TAILORED CRYO, SCHOTT offers the mirror blank material for the next generation of space telescope applications.
© (2014) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
R. Jedamzik, R. Jedamzik, T. Westerhoff, T. Westerhoff, "ZERODUR TAILORED for cryogenic application", Proc. SPIE 9151, Advances in Optical and Mechanical Technologies for Telescopes and Instrumentation, 91512P (18 July 2014); doi: 10.1117/12.2055086; https://doi.org/10.1117/12.2055086


Back to Top