Study for a Primary Mirror Truss for the 25 m Diameter CCAT Telescope

CCAT will be a 25 m diameter submillimeter-wave telescope that will operate inside a dome located on Cerro Chajnantor in the Atacama Desert. The telescope must have high aperture efficiency at a wavelength of 350 microns and good performance out to a wavelength of 200 microns. A conceptual design for a truss and primary reflector support truss has been developed. The material for this truss will be carbon-fiber-reinforced polymer (CFRP). It is a very strong, light material that has a very low coefficient of temperature expansion (CTE). Due to this material the adjustments of the mirror segments will be in a much smaller range than for a steel truss.