Share Email Print
cover

Proceedings Paper

Advanced structural design for precision radial velocity instruments
Author(s): Dan Baldwin; Andrew Szentgyorgyi; Stuart Barnes; Jacob Bean; Sagi Ben-Ami; Patricia Brennan; Jamie Budynkiewicz; Moo-Young Chun; Charlie Conroy; Jeffrey D. Crane; Harland Epps; Ian Evans; Janet Evans; Jeff Foster; Anna Frebel; Thomas Gauron; Dani Guzman; Tyson Hare; Bi-Ho Jang; Jeong-Gyun Jang; Andres Jordan; Jihun Kim; Kang-Min Kim; Claudia Mendes de Oliveira; Mercedes Lopez-Morales; Kenneth McCracken; Stuart McMuldroch; Joseph Miller; Mark Mueller; Jae Sok Oh; Mark Ordway; Byeong-Gon Park; Chan Park; Sung-Joon Park; Charles Paxson; David Phillips; David Plummer; William Podgorski; Andreas Seifahrt; Daniel Stark; Joao Steiner; Alan Uomoto; Ronald Walsworth; Young-Sam Yu
Format Member Price Non-Member Price
PDF $14.40 $18.00

Paper Abstract

The GMT-Consortium Large Earth Finder (G-CLEF) is an echelle spectrograph with precision radial velocity (PRV) capability that will be a first light instrument for the Giant Magellan Telescope (GMT). G-CLEF has a PRV precision goal of 40 cm/sec (10 cm/s for multiple measurements) to enable detection of Earth-like exoplanets in the habitable zones of sun-like stars1. This precision is a primary driver of G-CLEF’s structural design. Extreme stability is necessary to minimize image motions at the CCD detectors. Minute changes in temperature, pressure, and acceleration environments cause structural deformations, inducing image motions which degrade PRV precision. The instrument’s structural design will ensure that the PRV goal is achieved under the environments G-CLEF will be subjected to as installed on the GMT azimuth platform, including:
    Millikelvin (0.001 °K) thermal soaks and gradients
    10 millibar changes in ambient pressure
    Changes in acceleration due to instrument tip/tilt and telescope slewing
Carbon fiber/cyanate composite was selected for the optical bench structure in order to meet performance goals. Low coefficient of thermal expansion (CTE) and high stiffness-to-weight are key features of the composite optical bench design. Manufacturability and serviceability of the instrument are also drivers of the design.

In this paper, we discuss analyses leading to technical choices made to minimize G-CLEF’s sensitivity to changing environments. Finite element analysis (FEA) and image motion sensitivity studies were conducted to determine PRV performance under operational environments. We discuss the design of the optical bench structure to optimize stiffness-to-weight and minimize deformations due to inertial and pressure effects. We also discuss quasi-kinematic mounting of optical elements and assemblies, and optimization of these to ensure minimal image motion under thermal, pressure, and inertial loads expected during PRV observations.

Paper Details

Date Published: 22 July 2016
PDF: 16 pages
Proc. SPIE 9912, Advances in Optical and Mechanical Technologies for Telescopes and Instrumentation II, 99123I (22 July 2016); doi: 10.1117/12.2235250
Show Author Affiliations
Dan Baldwin, Harvard-Smithsonian Ctr. for Astrophysics (United States)
Andrew Szentgyorgyi, Harvard-Smithsonian Ctr. for Astrophysics (United States)
Stuart Barnes, Harvard-Smithsonian Ctr. for Astrophysics (United States)
Jacob Bean, The Univ. of Chicago (United States)
Sagi Ben-Ami, Harvard-Smithsonian Ctr. for Astrophysics (United States)
Patricia Brennan, Harvard-Smithsonian Ctr. for Astrophysics (United States)
Jamie Budynkiewicz, Harvard-Smithsonian Ctr. for Astrophysics (United States)
Moo-Young Chun, Korea Astronomy and Space Science Institute (Korea, Republic of)
Charlie Conroy, Harvard-Smithsonian Ctr. for Astrophysics (United States)
Jeffrey D. Crane, The Observatories of the Carnegie Institute for Science (United States)
Harland Epps, Univ. of California, Santa Cruz (United States)
Ian Evans, Harvard-Smithsonian Ctr. for Astrophysics (United States)
Janet Evans, Harvard-Smithsonian Ctr. for Astrophysics (United States)
Jeff Foster, Harvard-Smithsonian Ctr. for Astrophysics (United States)
Anna Frebel, Kavli Institute for Astrophysics and Space Research (United States)
Thomas Gauron, Harvard-Smithsonian Ctr. for Astrophysics (United States)
Dani Guzman, Pontificia Univ. Católica de Chile (Chile)
Tyson Hare, The Observatories of the Carnegie Institution of Science (United States)
Bi-Ho Jang, Korea Astronomy and Space Science Institute (Korea, Republic of)
Jeong-Gyun Jang, Korea Astronomy and Space Science Institute (Korea, Republic of)
Andres Jordan, Pontificia Univ. Católica de Chile (Chile)
Jihun Kim, Korea Astronomy and Space Science Institute (Korea, Republic of)
Kang-Min Kim, Korea Astronomy and Space Science Institute (Korea, Republic of)
Claudia Mendes de Oliveira, Univ. de São Paulo (Brazil)
Mercedes Lopez-Morales, Harvard-Smithsonian Ctr. for Astrophysics (United States)
Kenneth McCracken, Harvard-Smithsonian Ctr. for Astrophysics (United States)
Stuart McMuldroch, Harvard-Smithsonian Ctr. for Astrophysics (United States)
Joseph Miller, Harvard-Smithsonian Ctr. for Astrophysics (United States)
Mark Mueller, Harvard-Smithsonian Ctr. for Astrophysics (United States)
Jae Sok Oh, Korea Astronomy and Space Science Institute (Korea, Republic of)
Mark Ordway, Harvard-Smithsonian Ctr. for Astrophysics (United States)
Byeong-Gon Park, Korea Astronomy and Space Science Institute (Korea, Republic of)
Chan Park, Korea Astronomy and Space Science Institute (Korea, Republic of)
Sung-Joon Park, Korea Astronomy and Space Science Institute (Korea, Republic of)
Charles Paxson, Harvard-Smithsonian Ctr. for Astrophysics (United States)
David Phillips, Harvard-Smithsonian Ctr. for Astrophysics (United States)
David Plummer, Harvard-Smithsonian Ctr. for Astrophysics (United States)
William Podgorski, Harvard-Smithsonian Ctr. for Astrophysics (United States)
Andreas Seifahrt, The Univ. of Chicago (United States)
Daniel Stark, The Univ. of Arizona (United States)
Joao Steiner, Univ. de São Paulo (Brazil)
Alan Uomoto, The Observatories of the Carnegie Institution for Science (United States)
Ronald Walsworth, Harvard-Smithsonian Ctr. for Astrophysics (United States)
Young-Sam Yu, Korea Astronomy and Space Science Institute (Korea, Republic of)


Published in SPIE Proceedings Vol. 9912:
Advances in Optical and Mechanical Technologies for Telescopes and Instrumentation II
Ramón Navarro; James H. Burge, Editor(s)

© SPIE. Terms of Use
Back to Top