抚仙湖太阳观测和研究基地知识库

作为1m太阳望远镜(NVST)导行系统的重要组成部分,导行镜的成像稳定性至关重要。环境温度载荷造成的镜体变形会造成热离焦从而影响导行镜的成像质量。采用有限元方法分析NVST导行镜在-5℃、20℃和35℃等不同环境温度状态下的温度分布,并计算了温度变化产生的轴向结构变形,即最大离焦量为6.45μm。计算结果表明:主镜到靶面的距离变化最大值常温下为7.14μm远小于系统焦深(±35μm),达到了对NVST导行镜无热化结构设计的目的。

The guide telescope,as an integral part of the guide system of the 1m new vacuum solar telescope (NVST),its stability of imaging is essential.It is necessary to be concerned that the deformation of the telescope structure caused by environmental thermal load may cause thermal defocusing and affect the image quality of the guide telescope.The temperature distribution of guide telescope at - 5 ℃,20 ℃ and 35 ℃ were analyzed using finite element method,and then the axial deformation of guide telescope caused by temperature field was calculat -ed.The maximum defocusing amount is 6.45 μm,and the results show that the max change of distance between the primary mirror and the target surface is far less than the depth of focus (± 35 μm),which provides a basis to analyze the non-thermal design of guide telescope of NVST.