Seminar - Feng Fan - State-of-the-art Development of the Reflector Structure of FAST

Wednesday 30 May 2007, 1.10 - 1.50 pm
Civil Engineering Lecture Theatre 3

Abstract
FAST, Five-hundred-meter Aperture Spherical Telescope, is proposed for construct the Large Telescope (LT) by Chinese astronomers and engineering experts in 1993 and FAST will be the largest radio telescope in the world. FAST is a novel telescope with an overall aperture 500m, a radius of curvature 300m and a usable aperture 300m. As one important sub-system of FAST, the main active reflector brings great challenge to engineers. Based on an amount of theoretical and experimental research on the active reflector of FAST by authors in these past years, the feasibility of this innovative cable-net structure has been verified. The presentation is briefly introduced the structural concept of the active main reflector, theoretical and experiment study on the cable-net structure and back structure of the reflector sequentially. Finally, the analysis, design, construction and test of the 30m demonstrator of FAST in Miyun Astronomic Observation Station are introduced.

In 1993, 10 countries including USA, Australia, Canada, Netherlands and China have offered a proposal for construct the Large Telescope (LT), which nowadays is referred to as the Square Kilometer Array (SKA). Now, astronomers in many countries are engaged in research on SKA plan actively. Chinese astronomers and engineering experts proposed to use an active main spherical reflector and take advantage of Karst terrain of Guizhou Province in China for construct a giant radio telescope -FAST (Five hundred meter Aperture Spherical Telescope), and FAST will be the largest radio telescope in the world.

The innovative engineering concept and design pave a new road to realizing a huge single dish in the most effective way. Three outstanding features of the telescope are the unique Karst depressions as the sites, the reflector which corrects spherical aberration on the ground to achieve full polarization and a wide band without involving a complex feed system, and the light focus cabin driven by cables and servomechanism plus a parallel robot as secondary adjustable system to precisely position the feeds. FAST is a novel telescope with an overall aperture 500m, a radius of curvature 300m and a usable aperture 300m. As one important sub-system of FAST, the main active reflector brings great challenge to engineers. Fig. 1 and Fig. 2 show the 3-D image and basic conceptual sketch of FAST.


See the Space Daily article on FAST