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FAST望远镜馈源支撑中的力学问题及其研究进展 总被引:2,自引:0,他引:2
500 m口径球面射电望远镜FAST拥有多项创新和关键技术,并涉及多个工程学科领域,其中力学在望远镜设备的研制、建设和维护中扮演了非常重要的角色,包括望远镜台址的开挖与支护、反射面系统和馈源支撑系统等的设计均离不开对有关力学问题的分析.本文对十多年来FAST望远镜的馈源支撑系统中与力学方面相关的研究进展进行了全面回顾,重点介绍了当前的研究难点及其有待深入解决的问题.与传统望远镜的刚性馈源支撑相比FAST馈源支撑是一个完全创新的柔性机构,几乎在每一项子系统和机构单元的设计中均存在多种可能的方案设想,需要从中进行优化选择. 从力学角度对每一种方案进行性能评估,为最终的方案优化设计提供合理依据也是当前研究工作的一项紧迫任务. 相似文献
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Xu Hong Jianbin Zhou Shijun Ni Yingjie Ma Jianfeng Yao Wei Zhou Yi Liu Min Wang 《Journal of synchrotron radiation》2018,25(2):505-513
High‐precision measurement of X‐ray spectra is affected by the statistical fluctuation of the X‐ray beam under low‐counting‐rate conditions. It is also limited by counting loss resulting from the dead‐time of the system and pile‐up pulse effects, especially in a high‐counting‐rate environment. In this paper a detection system based on a FAST‐SDD detector and a new kind of unit impulse pulse‐shaping method is presented, for counting‐loss correction in X‐ray spectroscopy. The unit impulse pulse‐shaping method is evolved by inverse deviation of the pulse from a reset‐type preamplifier and a C‐R shaper. It is applied to obtain the true incoming rate of the system based on a general fast–slow channel processing model. The pulses in the fast channel are shaped to unit impulse pulse shape which possesses small width and no undershoot. The counting rate in the fast channel is corrected by evaluating the dead‐time of the fast channel before it is used to correct the counting loss in the slow channel. 相似文献