Gemini Preprint #30

Hardware Implementation of the Primary Mirror Surface Heating System for the Gemini 8 meter Telescopes

Brian Perona, Eric Hansen, David Hagelbarger, Andy Rudeen
Gemini 8m Telescopes Project, 950 N. Cherry Ave., Tucson AZ 85719


The Gemini 8m Telescopes Project is implementing two cooperating systems for thermal control of the monolithic primary mirror. The first system consists of temperature controlled radiation panels, behind the primary mirror, that are used to control the bulk temperature of the primary. The second system is the Surface Heating System which allows for adjustment of the optical surface temperature independent of the bulk mirror temperature. By heating just the reflective coating of the primary, a quicker thermal adjustment of the optical surface temperature can be achieved. The result is a minimizing of mirror seeing effects by better tracking of fluctuations in nighttime ambient temperature. A development effort and subscale prototype testing of this technique was completed by the Gemini staff in 1996 and presented at the SPIE Landskrona Conference. This paper reviews the detailed hardware design and implementation of a Surface Heating System being installed on the Gemini 8-meter primary mirror.

Appears in Proc. SPIE 3352, "Advanced Technology Optical/IR Telescopes".

Download the PostScript or PDF file.

Ruth A. Kneale / / March 30, 1998