Production of primary mirror segments for the Giant Magellan Telescope

H. M. Martin, R. G. Allen, James H Burge, J. M. Davis, W. B. Davison, M. Johns, D. W. Kim, Jeffrey S Kingsley, K. Law, R. D. Lutz, Peter A Strittmatter, Peng Su, M. T. Tuell, S. C. West, Ping Zhou

Research output: Chapter in Book/Report/Conference proceedingConference contribution

11 Citations (Scopus)

Abstract

Segment production for the Giant Magellan Telescope is well underway, with the off-axis Segment 1 completed, off-axis Segments 2 and 3 already cast, and mold construction in progress for the casting of Segment 4, the center segment. All equipment and techniques required for segment fabrication and testing have been demonstrated in the manufacture of Segment 1. The equipment includes a 28 m test tower that incorporates four independent measurements of the segment's figure and geometry. The interferometric test uses a large asymmetric null corrector with three elements including a 3.75 m spherical mirror and a computer-generated hologram. For independent verification of the large-scale segment shape, we use a scanning pentaprism test that exploits the natural geometry of the telescope to focus collimated light to a point. The Software Configurable Optical Test System, loosely based on the Hartmann test, measures slope errors to submicroradian accuracy at high resolution over the full aperture. An enhanced laser tracker system guides the figuring through grinding and initial polishing. All measurements agree within the expected uncertainties, including three independent measurements of radius of curvature that agree within 0.3 mm. Segment 1 was polished using a 1.2 m stressed lap for smoothing and large-scale figuring, and a set of smaller passive rigid-conformal laps on an orbital polisher for deterministic small-scale figuring. For the remaining segments, the Mirror Lab is building a smaller, orbital stressed lap to combine the smoothing capability with deterministic figuring.

Original languageEnglish (US)
Title of host publicationProceedings of SPIE - The International Society for Optical Engineering
PublisherSPIE
Volume9151
ISBN (Print)9780819496195
DOIs
StatePublished - 2014
EventAdvances in Optical and Mechanical Technologies for Telescopes and Instrumentation - Montreal, Canada
Duration: Jun 23 2014Jun 27 2014

Other

OtherAdvances in Optical and Mechanical Technologies for Telescopes and Instrumentation
CountryCanada
CityMontreal
Period6/23/146/27/14

Fingerprint

Telescopes
Telescope
Mirror
Mirrors
telescopes
mirrors
Geometry
Holograms
Polishing
Towers
Casting
Scanning
Fabrication
Lasers
Testing
smoothing
Smoothing
orbitals
Radius of curvature
Grinding

Keywords

  • Active optics
  • Aspheres
  • Giant Magellan Telescope
  • Off-axis
  • Optical fabrication
  • Optical testing
  • Telescopes

ASJC Scopus subject areas

  • Applied Mathematics
  • Computer Science Applications
  • Electrical and Electronic Engineering
  • Electronic, Optical and Magnetic Materials
  • Condensed Matter Physics

Cite this

Martin, H. M., Allen, R. G., Burge, J. H., Davis, J. M., Davison, W. B., Johns, M., ... Zhou, P. (2014). Production of primary mirror segments for the Giant Magellan Telescope. In Proceedings of SPIE - The International Society for Optical Engineering (Vol. 9151). [91510J] SPIE. https://doi.org/10.1117/12.2057012

Production of primary mirror segments for the Giant Magellan Telescope. / Martin, H. M.; Allen, R. G.; Burge, James H; Davis, J. M.; Davison, W. B.; Johns, M.; Kim, D. W.; Kingsley, Jeffrey S; Law, K.; Lutz, R. D.; Strittmatter, Peter A; Su, Peng; Tuell, M. T.; West, S. C.; Zhou, Ping.

Proceedings of SPIE - The International Society for Optical Engineering. Vol. 9151 SPIE, 2014. 91510J.

Research output: Chapter in Book/Report/Conference proceedingConference contribution

Martin, HM, Allen, RG, Burge, JH, Davis, JM, Davison, WB, Johns, M, Kim, DW, Kingsley, JS, Law, K, Lutz, RD, Strittmatter, PA, Su, P, Tuell, MT, West, SC & Zhou, P 2014, Production of primary mirror segments for the Giant Magellan Telescope. in Proceedings of SPIE - The International Society for Optical Engineering. vol. 9151, 91510J, SPIE, Advances in Optical and Mechanical Technologies for Telescopes and Instrumentation, Montreal, Canada, 6/23/14. https://doi.org/10.1117/12.2057012
Martin HM, Allen RG, Burge JH, Davis JM, Davison WB, Johns M et al. Production of primary mirror segments for the Giant Magellan Telescope. In Proceedings of SPIE - The International Society for Optical Engineering. Vol. 9151. SPIE. 2014. 91510J https://doi.org/10.1117/12.2057012
Martin, H. M. ; Allen, R. G. ; Burge, James H ; Davis, J. M. ; Davison, W. B. ; Johns, M. ; Kim, D. W. ; Kingsley, Jeffrey S ; Law, K. ; Lutz, R. D. ; Strittmatter, Peter A ; Su, Peng ; Tuell, M. T. ; West, S. C. ; Zhou, Ping. / Production of primary mirror segments for the Giant Magellan Telescope. Proceedings of SPIE - The International Society for Optical Engineering. Vol. 9151 SPIE, 2014.
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