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Proceedings Paper

Development of silver coating options for the Gemini 8-m telescopes project
Author(s): Michael Ray Jacobson; Ruth C. Kneale; Fred C. Gillett; Keith Raybould; John F. Filhaber; Charles K. Carniglia; Ronald Laird; Dennis Kitchens; Ric P. Shimshock; Donald C. Booth
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Paper Abstract

Acting as a prime contractor to the Gemini Project, the Optical Data Associates (ODA), with its major subcontractors, BOC Coating Technologies (BOCCT) and Deposition Sciences, Inc. (DSI), developed options for depositing protected silver coatings on the 8-M primary mirrors. The project began with a study that identified sputtering as the preferred deposition technique, defined a set of candidate adhesor and protective coatings for the silver layer, and simulated stack performance. The next phase involved pilot magnetron sputtering studies by BOCCT and DSI of designs involving silicon nitride and hafnia, respectively. ODA also developed mid-IR reflectance standards at (lambda) equals 10.6 micrometers to control the silver coating measurements in the critical 8 - 12 micrometers atmospheric window. The study results were successful, with both BOCCT and DSI producing Ag coatings with R equals 0.9920 +/- 0.0001 and protected Ag coatings with R equals 0.9910 +/- 0.0001. The Gemini Project coating plants are designed to sputter bare and protected Al and Ag coatings.

Paper Details

Date Published: 25 August 1998
PDF: 26 pages
Proc. SPIE 3352, Advanced Technology Optical/IR Telescopes VI, (25 August 1998); doi: 10.1117/12.319269
Show Author Affiliations
Michael Ray Jacobson, Optical Data Associates (United States)
Ruth C. Kneale, Gemini 8-m Telescopes Project (United States)
Fred C. Gillett, Gemini 8-m Telescopes Project (United States)
Keith Raybould, Gemini 8-m Telescopes Project (United States)
John F. Filhaber, AURA, Inc. (United States)
Charles K. Carniglia, BOC Coating Technology (United States)
Ronald Laird, BOC Coating Technology (United States)
Dennis Kitchens, Deposition Sciences, Inc. (United States)
Ric P. Shimshock, Deposition Sciences, Inc. (United States)
Donald C. Booth, Sigma Labs. Inc. (United States)

Published in SPIE Proceedings Vol. 3352:
Advanced Technology Optical/IR Telescopes VI
Larry M. Stepp, Editor(s)

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