大口径子镜拼接镜面共相维持试验研究

The segmented mirror active optics technology is one of the key technologies for the extremely large telescope, while edge sensor is one of the essential core components of active optics for the co-phasing maintenance of all segmented mirrors. The edge sensor technology has been grasped abroad on KECK I、 KECK II and GTC with a complete edge sensor customization, it has high measurement precision and can work in outdoor environment,so the price is very high.There are thounds of edge sensor in extremely large astronomical telescope and requires large amount of funds. Studying to a new type edge sensor with high measurement precision , and the thermal drift is also controlled by designing a small, soft and airtight temperature stable control system, putting the sensor head and electronics inside and making the local environmental temperature stable to keep away the influence of temperature factors. These edge sensors, together with common edge sensors ,displacement actuators and optical sensor, will build a global close-loop in order to realize the co-phasing maintenance of segmented mirrors. This research can reduce the cost of the telescope construction, help us grasp this main key technology of the extremely large telescope, advance the development of Chinese segmented mirror active optics, bring it to reach the international frontier, and also lay a solid foundation for Chinese extremely large telescope pre-research and construction.

拼接镜面主动光学技术是极大望远镜的关键核心技术，而边缘传感器是其核心组件，用以实现大规模拼接子镜的共相维持，已经成功应用于KECK和GTC，它具有纳米级精度且能在室外环境中工作。随着望远镜口径不断增大，边缘传感器的数量以几何级倍数增加，需要花费大量的资金。因此提出研究一种新型的高精度边缘传感器，再设计一种安装于子镜背面的小型密封温控系统将其密封，采用局部小范围温控的方法降低温度变化对其工作性能的影响，并与精度较低的普通边缘传感器、位移促动器、光学检测系统组成大闭环，采用高低精度边缘传感器混合搭配使用的新方法进行拼接镜面共相维持试验。掌握这项关键技术，可以降低望远镜的造价，并将极大提升我国拼接镜面共相维持技术水平，促进我国拼接镜面主动光学技术的发展，还能为我国极大望远镜预研以及建设打下基础。

拼接镜面主动光学技术是极大望远镜的关键核心技术，而边缘传感器是其核心组件，用以实现大规模拼接子镜的共相维持，已经成功应用于KECK和GTC等拼接镜面天文望远镜，它具有纳米级精度且能在室外环境中工作。随着望远镜口径不断增大，边缘传感器的数量以几何级倍数增加，需要花费大量的资金。为了向我国极大望远镜的建造提供亟需的技术储备，解决技术上的卡脖子问题，项目开展了高精度边缘传感器的研究，提出研究一种新型的高精度边缘传感器，再设计一种安装于子镜背面的小型密封温控系统将其密封，采用局部小范围温控的方法降低温度变化对其工作性能的影响。项目完成了新型双探头边缘传感器的设计，研制了两套样机并在实验室内完成了性能测试，达到了预期要求，传感器的噪声、时漂、温漂等性能接近国际前沿水平。此外，进行了半导体局部控温的研究，研制了样品并进行了温控精度测试。这些成果对于我们未来天文望远镜的建设具有重要的意义。