Manufacture of a 1.7m prototype of the GMT primary mirror segments

H. M. Martin; J. H. Burge; S. M. Miller; B. K. Smith; R. Zehnder; C. Zhao

doi:10.1117/12.672105

6 July 2006 Manufacture of a 1.7m prototype of the GMT primary mirror segments

H. M. Martin, J. H. Burge, S. M. Miller, B. K. Smith, R. Zehnder, C. Zhao

Proceedings Volume 6273, Optomechanical Technologies for Astronomy; 62730G (2006) https://doi.org/10.1117/12.672105
Event: SPIE Astronomical Telescopes + Instrumentation, 2006, Orlando, Florida , United States

Abstract

We have nearly completed the manufacture of a 1.7 m off-axis mirror as part of the technology development for the Giant Magellan Telescope. The mirror is an off-axis section of a 5.3 m f/0.73 parent paraboloid, making it roughly a 1:5 model of the outer 8.4 m GMT segment. The 1.7 m mirror will be the primary mirror of the New Solar Telescope at Big Bear Solar Observatory. It has a 2.7 mm peak-to-valley departure from the best-fit sphere, presenting a serious challenge in terms of both polishing and measurement. The mirror was polished with a stressed lap, which bends actively to match the local curvature at each point on the mirror surface, and works for asymmetric mirrors as well as symmetric aspheres. It was measured using a hybrid reflective-diffractive null corrector to compensate for the mirror's asphericity. Both techniques will be applied in scaled-up versions to the GMT segments.

Citation Download Citation

H. M. Martin, J. H. Burge, S. M. Miller, B. K. Smith, R. Zehnder, and C. Zhao "Manufacture of a 1.7m prototype of the GMT primary mirror segments", Proc. SPIE 6273, Optomechanical Technologies for Astronomy, 62730G (6 July 2006); https://doi.org/10.1117/12.672105

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