可见光波段测试Wolter-I型X射线望远镜的衍射影响分析  

Analysis of Diffraction Effects in Visible Wavelength Tests for Wolter-I X-Ray Telescope

作　　者：于可 李凤岐[1] 杨彦佶[2] 赵子健 鲁兵 张佳伟 陈勇[2] 吴开济 Yu Ke;Li Fengqi;Yang Yanji;Zhao Zijian;Lu Bing;Zhang Jiawei;Chen Yong;Wu Kaiji(School of Science,Shenyang Ligong University,Shenyang 110159,Liaoning,China;Key Laboratory for Particle Astrophysics,Institute of High Energy Physics,Chinese Academy of Sciences,Beijing 100049,China;Harbin Institute of Technology,Harbin 150001,Heilongjiang,China)

机构地区：[1]沈阳理工大学理学院,辽宁沈阳110159 [2]中国科学院高能物理研究所粒子天体物理重点实验室,北京100049 [3]哈尔滨工业大学机电工程学院,黑龙江哈尔滨150001

出　　处：《激光与光电子学进展》2023年第19期209-214,共6页Laser & Optoelectronics Progress

基　　金：中国科学院空间科学战略性先导科技专项(XDA1531010301)。

摘　　要：爱因斯坦探针卫星是一项针对时域天文学的任务,搭载的科学载荷后随X射线望远镜配备嵌套式镍镀金Wolter-I型X射线望远镜具有高灵敏度。角分辨是Wolter-I型X射线聚焦镜的重要性能指标,通常采用半能量直径表示。由于X射线聚焦镜在可见光与X射线下的光路相同,可以使用可见光代替X射线进行聚焦镜角分辨性能的检测,但也引入了可见光衍射的影响,为了说明此种影响,根据圆孔的夫琅禾费衍射理论,推导遮盖率极大的细圆环衍射分布公式,计算单层Wolter-I型镜片的可见光测试衍射影响。使用EP-FXT#18镜片在473 nm平行光条件下进行角分辨测试,可见光测试角分辨为32.02″±0.44″,推导计算可见光衍射影响为20.15″,从可见光测试结果中扣除衍射引入的误差影响后角分辨约为24.90″±1.61″,与中国科学院高能物理研究所在百米真空X射线下对镜片的测试结果25.10″+1.55″一致。The Einstein probe is a mission for time-domain astronomy.The follow-up X-ray telescope is a scientific payload on the EP.FXT is equipped with a nested gold-plated nickel Wolter-I X-ray telescope,which has an advantage in terms of angular resolution,a critical performance parameter for the Wolter-I X-ray telescope.The Wolter-I X-ray focusing mirror contributes the most angular resolution of the telescope.The angular resolution is typically represented in terms of the half-power diameter.Because its optical path is the same as X-rays,visible light can be used to measure the angular resolution performance of focusing mirrors instead of X-rays.However,this also results in the effect of visible light diffraction.This work evaluates the diffraction effects in a visible light test and derives an equation for determining the diffraction distribution of an annular aperture with a very high obstruction ratio based on the Fraunhofer diffraction theory.The angular resolution is measured as 32.02"±0.44"in the visible light test using the 18th EP-FXT mirror shell under a 473 nm parallel laser,and the contribution of the visible light diffraction is calculated to be 20.15".The value for the mirror shell is 24.90"±1.61".Compared to the 100 m vacuum X-ray calibration facility measurements of 25.10"±1.55"at the Institute of High Energy Physics,Chinese Academy of Science,these results are consistent within the margin of error.

关 键 词：Wolter-I EP-FXT 衍射效应 X射线聚焦镜 可见光测试 

分 类 号：O436.1[机械工程—光学工程]