中文摘要：

针对EUV太阳望远镜在地面非工作波段预先检测时出现的杂散光问题,考虑望远镜长焦距的特点,建立了基于反射镜转动扫描原理的杂散光测量系统,测量得到了望远镜的点源透射率（PST）曲线。通过对比PST曲线和分析望远镜结构,得出杂散光的主要来源为小角度下的一级杂光,由此设计了主次镜遮光罩,并利用Tracepro软件建立望远镜的实体模型,在不同散射表面的双向散射（BRDF）值条件下计算出遮光罩的消杂光效果。对PST实际测量结果表明,在0~4°,使用遮光罩使杂散光减少3个数量级,杂光系数不超过3.65%。在分辨率成像测量中,杂散光影响得到消除,系统分辨率接近衍射极限,满足地面上紫外光波段的测量要求。

英文摘要：

For the stray light from an Extreme Ultraviolet（EUV） solar telescope in the ground experiment,a measurement system for the Point Source Transmittance（PST） was established based on the parallel light introduced by the rotary scanning mirror at various angles and the PST curves were applied to assess the stray light level.By analyzing the structure of the telescope and the measured PST curves,the first order stray light under a small angle range was proved to be the main source of stray light.To eliminate the stray light, the principles of the baffles were presented in details and the simulation modeling of the telescope with baffles was created by Tracepro software.The eliminating ability of the baffle was calculated and tested at different Bidirectional Reflectance Distribution Function（BRDF） values.The test results show that the baffles can block most of the first order stray lights,the intensity of stray light has reduced 3 orders of magnitude,and the corresponding veiling glare index is less than 3.65%.With the help of baffles,the EUV telescope performs near the diffraction-limited condition at UV band,and all the requests for the imaging test can be met.