SPIE Astronomical Telescopes and Instrumentation
27 June - 2 July, 2010
Published papers and posters by Lick participants*
Experimental investigation of adhesive bond strength between metal
and optical glass
Lee H. Laiterman, Matthew V. Radovan, Gerald F. Cabak
UCO/Lick Observatory, University of California Santa Cruz
SPIE Document Library
Abstract
Within the general astronomical community as well as at the University of California Observatories, there has been a
long history of using epoxy to mount optics within instruments such as spectrometers and telescopes. The Ken & Gloria Levy Spectrometer, part of the Automated Planet Finder (APF) telescope located at Mt. Hamilton's Lick Observatory relies on epoxy-bonded joints to attach the instrument's large cross-dispersing prism and echelle grating to its Invar
space-frame structure. Design constraints dictated that these large optics each be attached at only three points, and that
the bond areas be as small as possible while maintaining an adequate strength factor of safety. Previous UCO
instruments, such as the Keck Telescopes' primary mirror segments and the ESI Spectrometer, used Hysol's 9313 epoxy
product for this purpose. Concerns over long-term reliability of such joints led us to re-examine this issue. We
empirically investigated the roles played by epoxy selection and techniques such as surface preparation and the use of a
primer, in creating a robust metal-to-glass bond. Bond strength data was generated, leading us to select a previously
unused epoxy, and to implement particular techniques to ensure bond quality. Most notably, we found that bond strength
data as typically reported on adhesive manufacturers’ datasheets was not a reliable indicator of long-term bond reliability
between metal and optical glass.
Paper
Poster
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A radial velocity spectrometer for the Automated Planet Finder Telescope at Lick Observatory
Matthew V. Radovan, Gerald F. Cabak, Lee H. Laiterman, Christopher T. Lockwood, Steven S. Vogt
UCO/Lick Observatory, University of California Santa Cruz
SPIE Document Library
Abstract
The Ken and Gloria Levy Spectrometer is being constructed at the Instrument Development Laboratory (Technical
Facilities) of UCO/ Lick Observatory for use on the 2.4 meter Automated Planet Finder Telescope at Mt. Hamilton. The
mechanical design of the instrument has been optimized for precision Doppler measurements. A key component of the
design is the space-frame structure that contains passive thermal compensation. Determinate hexapod structures are used
to mount the collimator, prism, and echelle grating. In this paper we describe the instrument mechanical design and some
features that will help it detect rocky planets in the habitable zone.
Paper
Poster
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Progress toward high-performance astronomical coatings
Andrew C. Phillips, William E. Brown, Brian Dupraw, David F. Hilyard, David J. Cowley
UCO/Lick Observatory, University of California Santa Cruz
SPIE Document Library
Abstract
We present an update on efforts at University of California Observatories to develop improved optical coatings for astronomical
telescopes and instruments. The main thrust has been in the areas of protected silver mirror coatings and sol-gel based anti-reflection
coatings. We report on the performance of silver coatings used for several years in Keck and Lick instruments, as well as that on the
Lick 1-m telescope. We discuss process improvements, including use of reactive ion-assisted deposition of oxides. Sol-gel based AR
coatings have been exposed to cryogenic environments to test their suitability for IR instruments, with encouraging results. Finally,
we describe our plans for future work.
Paper
Poster
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The Infrared Imaging Spectrograph (IRIS) for TMT: the atmospheric dispersion corrector
Andrew C. Phillips (a), Brian J. Bauman (b), James E. Larkin (c), Anna M. Moore (d), Cynthia N. Niehaus (c), David
Crampton (e), Luc Simard (e)
(a) University of California Observatories, CfAO, Univ. of California, Santa Cruz, CA, USA 95064
(b)Lawrence Livermore National Lab, 7000 East Ave, M/S L-210, Livermore, CA USA 94550
(c) Dept. of Physics & Astronomy, Univ. of California, Los Angeles, CA, USA 90095-1547
(d) Caltech Optical Observatories, 1200 E California Blvd, M/S 11-17, Pasadena, CA, USA 91125
(e) Dominion Astrophysical Observatory, National Research Council, 5071 W Saanich Rd, Victoria, BC, Canada V9E 2E7
SPIE Document Library
Abstract
We present a conceptual design for the atmospheric dispersion corrector (ADC) for TMT’s Infrared Imaging Spectrograph (IRIS). The
severe requirements of this ADC are reviewed, as are limitations to observing caused by uncorrectable atmospheric effects. The requirement
of residual dispersion less than 1 milliarcsecond can be met with certain glass combinations. The design decisions are discussed and the
performance of the design ADC is described. Alternative options and their performance tradeoffs are also presented.
Paper
Poster
*Copyright 2010 Society of Photo Optical Instrumentation Engineers. One print or electronic copy may be made for personal use only.
Systematic electronic or print reproduction and distribution, duplication of any material in this paper for a fee or for commercial
purposes, or modification of the content of the paper are prohibited.
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