@article{025d3c9cd11546c38534946a7d6567f6,
title = "The Simons Observatory: A large-diameter truss for a refracting telescope cooled to 1 K",
abstract = "We present the design and measured performance of a new carbon fiber strut design that is used in a cryogenically cooled truss for the Simons Observatory small aperture telescope. The truss consists of two aluminum 6061 rings separated by 24 struts. Each strut consists of a central carbon fiber tube fitted with two aluminum end caps. We tested the performance of the strut and truss by (i) cryogenically cycling and destructively pull-Testing strut samples, (ii) non-destructively pull-Testing the final truss, and (iii) measuring the thermal conductivity of the carbon fiber tubes. We found that the strut strength is limited by the mounting fasteners and the strut end caps, not the epoxy adhesive or the carbon fiber tube. This result is consistent with our numerical predictions. Our thermal measurements suggest that the conductive heat load through the struts (from 4 to 1 K) will be less than 1 mW. This strut design may be a promising candidate for use in other cryogenic support structures.",
author = "Crowley, {Kevin D.} and Peter Dow and Shroyer, {Jordan E.} and Groh, {John C.} and Bradley Dober and Jacob Spisak and Nicholas Galitzki and Tanay Bhandarkar and Devlin, {Mark J.} and Simon Dicker and Gallardo, {Patricio A.} and Kathleen Harrington and Jeffrey Iuliano and Johnson, {Bradley R.} and Delwin Johnson and Kofman, {Anna M.} and Akito Kusaka and Adrian Lee and Michele Limon and Federico Nati and John Orlowski-Scherer and Lyman Page and Michael Randall and Grant Teply and Tran Tsan and Wollack, {Edward J.} and Zhilei Xu and Ningfeng Zhu",
note = "Funding Information: This work was supported by the Simons Foundation, the University of Pennsylvania, and the University of Virginia. The authors would like to thank Natasha Smith at the University of Virginia for letting them use the Instron to test our strut samples. The authors would like to thank Jeff Engbrecht at Clearwater Composites for providing useful information about the CW1 and CW2 carbon fiber tubes. Zhilei Xu was supported by the Gordon and Betty Moore Foundation through Grant No. GBMF5215 to the Massachusetts Institute of Technology. Publisher Copyright: {\textcopyright} 2022 Author(s).",
year = "2022",
month = may,
day = "1",
doi = "10.1063/5.0093857",
language = "English (US)",
volume = "93",
journal = "Review of Scientific Instruments",
issn = "0034-6748",
publisher = "American Institute of Physics Publising LLC",
number = "5",
}