Translator Disclaimer
13 September 2012 Test production of a mirror segment for the Thirty Meter Telescope
Author Affiliations +
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.
© (2012) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
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);


The Giant Magellan Telescope (GMT)
Proceedings of SPIE (April 22 2008)
Fabrication and measured quality of the MMT primary mirror
Proceedings of SPIE (August 25 1998)
Optics for the 20/20 telescope
Proceedings of SPIE (January 30 2003)
Manufacture of 8.4 m off axis segments a 1...
Proceedings of SPIE (September 24 2004)

Back to Top