Suggested quasi-Cassegrain system for multi-beam observation of FAST

作     者：苏定强 白华 崔向群 Ding-Qiang Su;Hua Bai;Xiang-Qun Cui

作者机构：School of Astronomy and Space Science&Key Laboratory of the Ministry of EducationNanjing UniversityNanjing 210023China National Astronomical Observatories/Nanjing Institute of Astronomical Optics and Technology(NIAOT)Chinese Academy of ScienceNanjing 210042China 

出 版 物：《Research in Astronomy and Astrophysics》 (天文和天体物理学研究（英文版）)

年 卷 期：2020年第20卷第1期

页      面：1-5页

核心收录：

学科分类：0709[理学-地质学] 07[理学] 0708[理学-地球物理学] 070401[理学-天体物理] 0825[工学-航空宇航科学与技术] 0704[理学-天文学] 

主　　题：telescope techniques:miscellaneous methods:miscellaneous instrumentation:miscellaneous surveys 

摘      要：FAST,the largest single-dish radio telescope in the world,has a 500-meter diameter main reflector and a 300-meter diameter illuminated *** has a main reflector that can vary its shape,which continuously changes the shape of the illuminated area in reflector into a *** this article,we propose a quasiCassegrain system for *** detailed design results are *** a quasi-Cassegrain system only needs to add a 14.6-meter diameter secondary reflector,which is close to the size of the feed *** distance from the secondary reflector to the focus is only 5.08 m,and it has excellent image *** this quasi-Cassegrain system,the shape of the illuminated area in the main reflector continuously changes into an optimized *** this quasi-Cassegrain system from frequency 0.5 GHz to 8 GHz,the multi-beam system can include 7 to 217 *** this system is used in combination with Phased Array Feed(PAF)technology,more multi-beam feeds or a higher working frequency can be used.