【作者】 杨林；

【导师】 陈波；

【作者基本信息】 中国科学院研究生院（长春光学精密机械与物理研究所） ， 光学， 2011， 博士

【摘要】 随着空间技术的发展,极紫外-软X射线波段的太阳观测研究逐渐成为空间天文学的重要组成部分。空间太阳望远镜作为进行太阳观测的重要仪器之一,为研究太阳活动和空间天气提供了新方法和重要的物理依据。本文重点针对我国首台EUV波段成像仪器——极紫外太阳望远镜的地面检测进行了系统的研究,为望远镜工程研制和在轨应用打下坚实的基础。首先研究了EUV望远镜的光学设计,通过对光学元件失调量的计算确定了望远镜的像差影响,给出了望远镜的装调方案。讨论了计算机辅助装调技术(Computer Aided Alignment,CAA)在EUV望远镜实际装调中的应用,利用CAA技术完成了望远镜的实际装调工作。并利用测量得到的次镜失调量分析了30.4nm波段下望远镜的角分辨率为0.28″。在地面检测和实际应用中,EUV望远镜都存在杂散光问题。建立了望远镜的杂光点源透过率(Point Source Transmittance,PST)的测量实验装置。由EUT结构和PST测量结构分析望远镜的杂光主要来源,设计阻挡该一级杂光的遮光罩,使EUT的杂光系数下降到1.31%,为望远镜在地面的成像检测奠定了基础,保证了分辨率成像检测的准确性。讨论了望远镜的多层膜反射镜和滤光片的检测方法,计算了望远镜的传输效率。重点研究了EUV望远镜的成像质量检测方法,完成了望远镜的非工作波段分辨率检测。结果表明:在404.7nm波段EUV望远镜的角分辨率达到0.96",十分接近衍射极限(0.9"),实现了望远镜亚角秒的成像要求。最后针对短波段散射问题,给出了一种基于反射镜表面粗糙度的望远镜工作波段分辨率计算方法。分析两镜系统中散射光线的传播路径,推导了望远镜的散射系数。根据实测的反射镜表面粗糙度数据,建立了包含散射面的EUV望远镜散射计算模型,通过模型计算得出望远镜在30.4nm波长的散射对望远镜的角分辨率影响小于0.08"。通过间接的方法得到望远镜在工作波段下的光学分辨率为0.37",使用13μm/pixel的CCD的望远镜系统在工作波段下的角分辨率为0.85"。更多还原

【Abstract】 With the development of space technology, the solar observation in space has become a significant part of the space astronomy in the extreme ultraviolet and soft x-ray region. As one of most important sun observation devise, the space solar telescope can provide important physical basises and new methods for the studies on solar activity and space weather. The extreme ultraviolet solar telescope (EUT) is the first EUV band imager in China for solar observation. In this dissertation, the ground tests and performance evaluations of the EUT are systematically investigated for future on-orbit applications.The optical design of the EUT is discussed in detail and the aberration effects due to the misalignments of the optical elements are analyzed. The applications of the computer aided alignment (CAA) method in actual assembly and adjustment of the EUT are discussed. The place offsets of the secondary mirror determined accurately by CAA are used to calculate the angular resolution of the EUT at 30.4 nm.The stray light exists in the ground test and on-orbit applications for the EUT. A system is established to measure the point source transmittance (PST) of the stray light in the EUT. The main source of the stray light is found by analyzing the telescope’s structure and the results of the PST test. Baffles are performed to block the first order stray light of the EUT and the resulting veiling glare index is 1.31%, which provides basis for the ground-based imaging test and guarantees the accuracy of the resolution test. The performance of the multilayer mirror and metal-film filter are calibrated and the transmittance of the EUT is 5.06×10-4 calculated by the calibration results. The design of the collimator which is used in the imaging test is discussed in detail. The resolution imaging test is performed to estimate the imaging ability of the EUT. The results indicate that the angular resolution is 0.96" which closed to the diffraction-limited performance (0.9") at 404.7nm.After the imaging test is done, the scatter at working wavelength is mainly studied. The scatter effects due to the mirror’s surface roughness are discussed and a calculation method for the resolution of the EUT is presented. Based on the practical measured PSD data of two mirrors, a model of the EUT is established and the resolution reduction due to the scatter is calculated to be 0.08" at 30.4nm. The optical resolution of the EUT is calculated to be 0.37" in an indirect way and the whole system resolution of the EUT was 0.85" with a CCD of 13μm/pixel.更多还原