@inproceedings{5a421be391ef4ea39291a454f2e82ea2,
title = "Production of 8.4 m primary mirror segments for GMT",
abstract = "The Richard F. Caris Mirror Lab at the University of Arizona continues production of 8.4 m lightweight honeycomb segments for the primary mirror of the Giant Magellan Telescope. GMT's 25 m primary mirror consists of a center segment surrounded by six off-axis segments, with an additional off-axis segment to allow continuous operation as segments are removed for coating. We cast the sixth segment (5 off-axis segments + center segment) in March 2021. As of June 2022 we have tentatively completed polishing of the third off-axis segment, and we are in the process of grinding the optical surface of off-axis Segment 5. For Segment 3, we improved the measurement accuracy for small-scale structure near the edge of the mirror, which has been a challenge for the off-axis segments. In addition to full-aperture interferometry and deflectometry, we used a 20 cm test plate to obtain high-resolution interferometric measurements of the edge.",
keywords = "Giant Magellan Telescope, aspheres, off-axis, optical fabrication, optical testing, telescopes",
author = "Martin, {H. M.} and R. Ceragioli and V. Gasho and Jannuzi, {B. T.} and Kim, {D. W.} and Kingsley, {J. S.} and K. Law and A. Loeff and Lutz, {R. D.} and S. Meyen and Oh, {C. J.} and Tuell, {M. T.} and Weinberger, {S. N.} and West, {S. C.} and R. Whitsitt and R. Wortley",
note = "Funding Information: Work for the Giant Magellan Telescope is supported by the GMTO Corporation, an international consortium of leading universities and research institutions representing five countries: Arizona State University, Astronomy Australia Limited, Australian National University, Carnegie Institution for Science, FAPESP–The S{\~a}o Paulo Research Foundation, Harvard University, Korea Astronomy and Space Science Institute, Smithsonian Institution, Texas A&M University, The University of Texas at Austin, University of Arizona, University of Chicago, Weizmann Institute of Science. Publisher Copyright: {\textcopyright} COPYRIGHT SPIE. Downloading of the abstract is permitted for personal use only.; Advances in Optical and Mechanical Technologies for Telescopes and Instrumentation V 2022 ; Conference date: 17-07-2022 Through 22-07-2022",
year = "2022",
doi = "10.1117/12.2630378",
language = "English (US)",
series = "Proceedings of SPIE - The International Society for Optical Engineering",
publisher = "SPIE",
editor = "Ramon Navarro and Roland Geyl",
booktitle = "Advances in Optical and Mechanical Technologies for Telescopes and Instrumentation V",
}