摘要
大视场日冕仪主要用来对215倍太阳半径内的日冕进行全周向观测以监测太阳活动并对影响日地空间的灾害性空间天气进行预警。根据杂散光抑制要求,将大视场日冕仪的光学系统设计成外掩透射式二次成像结构,其光学系统长度为355.89 mm,视场为±20°,焦距为40 mm。将大视场日冕仪杂散光按照光强分为三级,其中一级为太阳直射光,二级为外掩体和外窗口边缘的衍射光,三级为内掩体表面反射光、物镜口径边缘的衍射光和散射杂散光。对这三级杂散光分别进行抑制后得到内视场的杂散光抑制水平为10-9量级,外视场的杂散光抑制水平为10-13量级。
The large field of view coronagraph is used to image the corona within 215 solar radii. This coronagraph can be used to monitor the solar activity and forecast the violent space weather events. For the need of the stray light suppression, the coronagraph is designed to be an external occulted and secondary imaging system. The optical system has a length of 355.89 mm, a field of view of ± 20° and a focal length of 40 mm. The stray light of the coronagraph is divided into three levels by the intensity. The first level is the direct light from the sun. The second level is the diffracted light from the occulter and external diaphragm. The third level is the reflected light from the inner occulter, the diffracted light from the objective aperture and the scatted light. The three levels of stray light are suppressed respectively. Finally, the stray light level of the coronagraph is 10^-9 at the inner field and 10^-13 at the outer field.
出处
《激光与光电子学进展》
CSCD
北大核心
2014年第5期158-164,共7页
Laser & Optoelectronics Progress
基金
中国科学院战略性先导科技专项项目(XDA04071800
XDA04060804)
关键词
光学设计
日冕仪
杂散光
外掩式
二次成像
optical design
coronagraph
stray light
externally occulted
secondary imaging
