27 July 2016 Ethylene glycol contamination effects on first surface aluminized mirrors
Author Affiliations +
Abstract
The Dark Energy Spectroscopic Instrument (DESI) is under construction for installation on the Mayall 4 Meter telescope. The use of a liquid cooling system is proposed to maintain the DESI prime focus assembly temperature within ±1°C of ambient. Due to concerns of fluid deposition onto optical surfaces from possible leaks, systematic tests were performed of the effects on first surface aluminized mirrors of ethylene glycol and two other candidate coolants. Objective measurement of scattering and reflectivity was an important supplement to visual inspection. Rapid cleanup of a coolant spill followed by a hand wash of the mirror limited surface degradation to the equivalent of a few months of general environmental exposure. Prolonged exposure to corrosive coolants dissolved the aluminum, necesitating mirror recoating.
© (2016) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Patrick Dunlop, Patrick Dunlop, Ronald G. Probst, Ronald G. Probst, Matthew Evatt, Matthew Evatt, Larry Reddell, Larry Reddell, David Sprayberry, David Sprayberry, } "Ethylene glycol contamination effects on first surface aluminized mirrors", Proc. SPIE 9906, Ground-based and Airborne Telescopes VI, 99063F (27 July 2016); doi: 10.1117/12.2233233; https://doi.org/10.1117/12.2233233
PROCEEDINGS
13 PAGES


SHARE
RELATED CONTENT

Evaluation of thin films for mirror coating at the Subaru...
Proceedings of SPIE (February 04 2003)
Mirror cleaning investigations at the CFHT
Proceedings of SPIE (June 01 1994)
In situ aluminization of the MMT 6.5m primary mirror
Proceedings of SPIE (July 06 2006)
Advances in telescope mirror cleaning
Proceedings of SPIE (September 24 2004)
In situ cleaning of the primary mirror of the Subaru...
Proceedings of SPIE (August 25 1998)

Back to Top