Design for CCAT, a 25 m diameter telescope operating from 200 GHz to 1.5 THz

Author

Woody, David ; Padin, Steve ; Redding, Dave ; Lou, John ; Kissil, Andy

Author_Institution

Owens Valley Radio Obs., Caltech, Big Pine, CA, USA

fYear

2011

fDate

13-20 Aug. 2011

Firstpage

1

Lastpage

4

Abstract

CCAT will be a 25 m diameter Ritchey-Chretien telescope operating in the 0.2-1.5 mm wavelength range. It will be located at an altitude of 5600 m on Cerro Chajnantor in northern Chile, near the ALMA site. CCAT will have an f/0.4 primary, with an active surface to compensate gravitational and thermal deformations. The primary will be supported by a carbon fiber reinforced plastic (CFRP) space frame truss on an elevation over azimuth mount made of steel. Cameras and spectrometers with up to 1 deg field of view (FoV) will be located at the two f/6 Nasmyth foci. CCAT will be inside an enclosure to reduce wavefront and pointing errors due to wind forces and thermal deformation due to solar illumination. The key performance challenges for CCAT are a half wavefront error (HWFE) <;10 μm rms and pointing error <;0.2".

Keywords

radiotelescopes; ALMA site; CCAT; Cerro Chajnantor; Ritchey-Chretien telescope; carbon fiber reinforced plastic space frame truss; frequency 200 GHz to 1.5 THz; gravitational deformation; half wavefront error; northern Chile; pointing error; size 25 m; solar illumination; thermal deformation; wind forces; Charge coupled devices; Gravity; Motion segmentation; Optical surface waves; Sensors; Steel; Telescopes;

fLanguage

English

Publisher

ieee

Conference_Titel

General Assembly and Scientific Symposium, 2011 XXXth URSI

Conference_Location

Istanbul

Print_ISBN

978-1-4244-5117-3

Type

conf

DOI

10.1109/URSIGASS.2011.6051257

Filename

6051257