Active Control of Edges and Global Microstructure on Segmented Mirrors

D. D. Walker, A. Beaucamp, C. Dunn, R. Evans, R. Freeman, R. Morton, S. Wei, G. Yu

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

13 Citations (Scopus)

Abstract

In this paper we address two interrelated issues important to primary mirror segments for extremely large telescopes - edge-control, and the detailed topography over the segment surface. Both affect the intensity and distribution of stray light and infrared emissivity. CNC polishing processes typically deploy spiral or raster tool-paths, tending to leave repetitive features. We compare and contrast two novel families of pseudo-random tool-paths for Precessions CNC polishing. We then show how CNC control of the three-dimensional tool-path can optimize edge-profiles. Finally, we demonstrate fluid-jet polishing used to clean up residual edge defects.

Original languageEnglish
Title of host publicationAdvanced Optical and Mechanical Technologies in Telescopes and Instrumentation
EditorsEli Atad-Ettedgui, Dietrich Lemke
PublisherSPIE
Number of pages9
Volume7018, Part 1
ISBN (Print)9780819472281
DOIs
Publication statusPublished - 23 Jul 2008
Externally publishedYes
EventSPIE Astronomical Telescopes and Instrumentation - Marseille, France
Duration: 23 Jun 200828 Jun 2008

Publication series

NameProceedings of SPIE - The International Society for Optical Engineering
PublisherSPIE
Volume7018
ISSN (Print)0277-786X
ISSN (Electronic)1996-756X

Conference

ConferenceSPIE Astronomical Telescopes and Instrumentation
CountryFrance
CityMarseille
Period23/06/0828/06/08

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Cite this

Walker, D. D., Beaucamp, A., Dunn, C., Evans, R., Freeman, R., Morton, R., ... Yu, G. (2008). Active Control of Edges and Global Microstructure on Segmented Mirrors. In E. Atad-Ettedgui, & D. Lemke (Eds.), Advanced Optical and Mechanical Technologies in Telescopes and Instrumentation (Vol. 7018, Part 1). [701812] (Proceedings of SPIE - The International Society for Optical Engineering; Vol. 7018). SPIE. https://doi.org/10.1117/12.787930