The 60-meters submillimeter telescope is a large astronomical facility under proposed with the advantages of high sensitivity and large field of view, which mainly planned to observe the low temperature gas and dust in the universe. The aperture of primary reflector is 60 meters, and the requirement of surface error is 30μm rms which enables it to observe in the wavelength of 0.65mm to 3mm. In order to achieve the high accuracy requirements of telescope, the primary reflector is design to be composed of CFRP segments in one of the conceptual design schemes, similar to Large Millimeter Telescope (LMT). The natural limit of surface accuracy and pointing accuracy of telescope will be improved after the application of CFRP with the advantages of high specific stiffness and low thermal expansion, etc. This paper describes the initial development of a 3 meters prototype CFRP reflector segment, mainly including the design process of support truss and manufacture status of panel and truss.
One prototype carbon fiber-reinforced plastics (CFRP) panel for 5-m Dome A Terahertz Explorer antenna is replicated successfully in meeting the surface accuracy requirement of less than 10 μm rms by using resin-rich layer technology. By considering the unconventional thermal deformation behavior of a composite structure, a finite-element model (FEM) is produced to predict the thermal deformation behavior of the panel at low temperature. Effects of structural parameters on thermal deformation behavior of the panel are discussed and they are used in the design and in the structural optimization for minimizing surface thermal deformation error at low temperature. An experimental method based on high precision photogrammetry is used to measure the thermal deformation error of the prototype panel. The method has been used for updating the properties of the FEM so that the FEM becomes even more accurate. A prototype panel with high surface accuracy and high thermal stability has been manufactured recently based on the design parameters given by the updated FEM. Plans for improvements in structure design and molding process are also provided at the end of the paper.