Test production of a mirror segment for the Thirty Meter Telescope

Tetsuji Oota; Hirohiko Shinonaga; Kotaro Akutsu; Yuichiro Hashimoto; Itaru Otsuka; Yasushi Iwasaki; Masanori Iye; Takuya Yamashita; Hiroshi Akitaya; Ryuji Suzuki

doi:10.1117/12.926945

13 September 2012 Test production of a mirror segment for the Thirty Meter Telescope

Tetsuji Oota, Hirohiko Shinonaga, Kotaro Akutsu, Yuichiro Hashimoto, Itaru Otsuka, Yasushi Iwasaki, Masanori Iye, Takuya Yamashita, Hiroshi Akitaya, Ryuji Suzuki

Author Affiliations +

Proceedings Volume 8450, Modern Technologies in Space- and Ground-based Telescopes and Instrumentation II; 84502B (2012) https://doi.org/10.1117/12.926945
Event: SPIE Astronomical Telescopes + Instrumentation, 2012, Amsterdam, Netherlands

Abstract

The Thirty Meter Telescope (TMT) is a next-generation optical/infrared telescope to be constructed on Mauna Kea, Hawaii toward the end of this decade, as an international project. Its 30 m primary mirror consists of 492 off-axis aspheric segmented mirrors. This paper describes the progress of the test fabrication of an outermost mirror segment for the TMT as a joint R&D program between National Astronomical Observatory and Canon. A zero-expansion glass CLEARCERAM™ blank was polished by a computer-controlled small-tool polishing machine (CSSP, Canon) and its surface shape was measured by a touch-probe measuring machine(A-Ruler, Canon). Residuals of lower Zernike terms of the surface shape were 11 nmRMS, clearing the original specifications based on the structure function. There remains, however, a need to fulfill latest revised specifications. Possible solutions to improve and achieve the new specifications and a plan for revising the process for mass production are also described.

Citation Download Citation

Tetsuji Oota, Hirohiko Shinonaga, Kotaro Akutsu, Yuichiro Hashimoto, Itaru Otsuka, Yasushi Iwasaki, Masanori Iye, Takuya Yamashita, Hiroshi Akitaya, and Ryuji Suzuki "Test production of a mirror segment for the Thirty Meter Telescope", Proc. SPIE 8450, Modern Technologies in Space- and Ground-based Telescopes and Instrumentation II, 84502B (13 September 2012); https://doi.org/10.1117/12.926945

ACCESS THE FULL ARTICLE

INSTITUTIONAL
Select your institution to access the SPIE Digital Library.

SELECT YOUR INSTITUTION

PERSONAL
Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.

PERSONAL SIGN IN

No SPIE Account? Create one

PURCHASE THIS CONTENT

SUBSCRIBE TO DIGITAL LIBRARY

50 downloads per 1-year subscription

Members: $195

Non-members: $335 ADD TO CART

25 downloads per 1 - year subscription

Members: $145

Non-members: $250 ADD TO CART

PURCHASE SINGLE ARTICLE

Includes PDF, HTML & Video, when available

Members: $17.00

Non-members: $21.00 ADD TO CART

PROCEEDINGS
8 PAGES

DOWNLOAD PAPER SAVE TO MY LIBRARY

GET CITATION

RIGHTS & PERMISSIONS

Get copyright permission Get copyright permission on Copyright Marketplace

KEYWORDS

Mirrors

Polishing

Surface finishing

Thirty Meter Telescope

Monochromatic aberrations

Segmented mirrors

Interferometers

Show All Keywords

Keywords/Phrases

Search In:

Publication Years