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Proceedings Paper

Status of the coating facility of the Subaru Telescope
Author(s): Saeko S. Hayashi; Yukiko Kamata; Tomio Kanzawa; Akihiko Miyashita; Masao Nakagiri; Tetsuo Nishimura; Takeshi Noguchi; Kiichi Okita; Norio Oshima; Goro Sasaki; Yasuo Torii; Masami Yutani; Tsuyoshi Ishikawa
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Paper Abstract

One of the major problems to retain the efficiency of a telescope is to achieve and maintain high reflectivity in the wide wavelengths of the coatings of the telescope optics. For coating the large mirrors of Subaru Telescope, we employed the conventional evaporation scheme, in the expectation of uniform coverage of the film. In this paper, we will report the installation and the performance verification of the coating facility. This facility consists of a washing tower for stripping off the old coating, an evaporation coating chamber, two trolleys and a scissors- like lifter for handling the primary mirror. To supply a large number of filaments loaded with uniform quality molten metal, the practical solution is to pre-wet the filaments with the agent metal and keep them in a controlled manner before the evaporation. The aluminum film deposit on the test samples in the 8.3 m coating chamber proved the film thickness uniformity matching with the specification. Reflectivity of the fresh surface was over 90% at visible wavelength. In September 1997, we re-aluminized 1.6 m and 1.3 m mirrors for the first time (at least for ourselves) application to the real astronomical telescopes. The resultant surface reflectivity confirmed the feasibility of using pre-wetted filaments.

Paper Details

Date Published: 25 August 1998
PDF: 9 pages
Proc. SPIE 3352, Advanced Technology Optical/IR Telescopes VI, (25 August 1998); doi: 10.1117/12.319267
Show Author Affiliations
Saeko S. Hayashi, National Astronomical Observatory of Japan (United States)
Yukiko Kamata, National Astronomical Observatory of Japan (Japan)
Tomio Kanzawa, National Astronomical Observatory of Japan (United States)
Akihiko Miyashita, National Astronomical Observatory of Japan (United States)
Masao Nakagiri, National Astronomical Observatory of Japan (Japan)
Tetsuo Nishimura, National Astronomical Observatory of Japan (United States)
Takeshi Noguchi, National Astronomical Observatory of Japan (Japan)
Kiichi Okita, National Astronomical Observatory of Japan (Japan)
Norio Oshima, National Astronomical Observatory of Japan (Japan)
Goro Sasaki, National Astronomical Observatory of Japan (Japan)
Yasuo Torii, National Astronomical Observatory of Japan (Japan)
Masami Yutani, National Astronomical Observatory of Japan (Japan)
Tsuyoshi Ishikawa, Mitsubishi Electric Corp. (Japan)


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

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