Computer Science – Performance
Scientific paper
Aug 1998
adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=1998spie.3352..258k&link_type=abstract
Proc. SPIE Vol. 3352, p. 258-267, Advanced Technology Optical/IR Telescopes VI, Larry M. Stepp; Ed.
Computer Science
Performance
Scientific paper
The 1-m diameter lightweight secondary mirrors (M2) for the Gemini 8-m telescopes will be the largest CVD-SiC mirrors ever produced. The design and manufacture of these mirrors is a very challenging task. In this paper we will discuss the mirror design, structural and mechanical analysis, and the CVD manufacturing process used to produce the mirror blanks. The lightweight design consist of a thin faceplate (4-mm) and triangular backstructure cells with ribs of varying heights. The main drivers in the design were weight (40 kg) and manufacturing limitations imposed on the backstructure cells and mirror mounts. Finite element modeling predicts that the mirror design will meet all of the Gemini M2 requirements for weight, mechanical integrity, resonances, and optical performance. Special design considerations were necessary to avoid stress concentration in the mounting areas and to meet the requirement that the mirror survive an 8-g earthquake. The highest risk step in the mirror blank manufacturing process is the near-net-shape CVD deposition of the thin, curved faceplate. Special tooling and procedures had to be developed to produce faceplates free of fractures, cracks, and stress during the cool-down from deposition temperature (1350 C) to room temperature. Due to time delay with the CVD manufacturing process in the meantime a backup solution from Zerodur has been started. This mirror is now in the advanced polishing process. Because the design of both mirrors is very similar an excellent comparison of both solutions is possible.
Knohl Ernst-Dieter
Pickering Michael A.
Schoeppach Armin
No associations
LandOfFree
Status of the secondary mirrors (M2) for the Gemini 8-m telescopes does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with Status of the secondary mirrors (M2) for the Gemini 8-m telescopes, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Status of the secondary mirrors (M2) for the Gemini 8-m telescopes will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-1538732