eXTP聚焦镜电子偏转器仿真分析与设计  

Simulation analysis and design of electron deflector for eXTP focusing telescope

作　　者：郑人洲 强鹏飞 杨彦佶[2] 闫永清 李悦 盛立志[1] 陈勇[2] ZHENG Renzhou;QIANG Pengfei;YANG Yanji;YAN Yongqing;LI Yue;SHENG Lizhi;CHEN Yong(State Key Laboratory of Transient Optics and Photonics,Xi’an Institute of Optics and Precision Mechanics,Chinese Academy of Sciences,Xi’an 710119,China;Key Laboratory of Particle Astrophysics,Institute of High Energy Physics,Chinese Academy of Sciences,Beijing 100049,China)

机构地区：[1]中国科学院西安光学精密机械研究所,瞬态光学与光子技术国家重点实验室,西安710119 [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

出　　处：《物理学报》2025年第5期9-19,共11页Acta Physica Sinica

基　　金：国家自然科学基金(批准号:42327802,62271483);国家重点实验室基金(批准号:SKLIPR2021);陕西省自然科学基础研究计划(批准号:2023-JC-ZD-40,2024JC-YBQN-0003);中国博士后科学基金第76批面上项目(批准号:2024M763511)资助的课题.

摘　　要：X射线聚焦望远镜是进行空间X射线观测的核心设备,为保证其观测结果的准确性,需要对进入聚焦镜的低能电子进行有效偏转,达到降低本底噪声的目的.本文针对增强型X射线时变与偏振空间天文台(enhanced X-ray timing and polarimetry mission,eXTP)聚焦镜电子偏转器研制工作,满足聚焦镜光学系统对于低能电子的偏转需求,兼顾轻量化、电子偏转能力以及电磁兼容性能等问题,采用有限元分析软件COMSOL Multiphysics建立了电子偏转器及聚焦镜镜片的全物理仿真模型,分析了磁感应强度分布、电子偏转轨迹以及磁场对聚焦镜镜片的影响,完成了电子偏转器电磁参数设计.模拟结果表明,电子偏转器周围空间中磁感应强度沿半径方向减小,两根辐条正中间磁感应强度最大值可达0.027 T.在磁感应强度平面及纵向分布中,当半径大于280 mm或纵向距离大于60 mm时,磁感应强度小于5×10^(–5)T(0.5 Gs),满足电磁兼容性能设计要求.当入射角≤10°时,电子偏转效率随电子能量和入射角增大而减小,50 keV能量以下电子偏转效率可达100%,满足电子偏转设计要求.聚焦镜镜片底端距离电子偏转器130 mm时,聚焦镜镜片在磁场的作用下,应力大小仅为10^(–3)N/m^(2)量级,形变大小仅为10^(–5)nm量级,表明磁场不会对聚焦镜的光学性能产生影响.这些结果为eXTP聚焦镜电子偏转器的研制工作提供了重要参考.X-ray focusing telescope is the core equipment for space X-ray observation.In order to ensure the accuracy of the observation results,it is necessary to deflect the low-energy electrons entering the focusing telescope to effectively reduce the background noise.In this work,the electron deflector for enhanced X-ray timing and polarimetry mission(eXTP)focusing telescope is developed to meet the deflection requirements of low-energy electrons in the focusing telescope optical system,with the lightweight,ability to deflect electrons,and electromagnetic compatibility considered.The finite element analysis software COMSOL Multiphysics is used to establish the full physical simulation model of the electron deflector and focusing telescope mirrors.The magnetic flux density distribution,electron deflection trajectories and the effect of magnetic field on focusing telescope mirrors are analyzed,and the electromagnetic parameters of the electron deflector are designed.The simulation results show that the closer to the magnet and the center of electron deflector,the greater the magnetic flux density,and the maximum magnetic flux density in the middle of the two spokes can reach 0.027 T.When the radius is larger than 280 mm,the longitudinal distance is larger than 60 mm,the magnetic flux density is less than 5×10^(–5) T(0.5 Gs),i.e.the geomagnetic intensity,which meets the design requirements of electromagnetic compatibility performance.When the incidence angle is≤10°,the electron deflection efficiency decreases with the increase of electron energy and incidence angle,and the deflection efficiency of electrons below 50 keV energy can reach 100%,which meets the design requirements of electron deflection.In addition,as the focusing telescope mirrors are away from the electron deflector,the area of mirrors affected by the magnetic field becomes smaller and smaller.When the distance between the mirror bottom and electron deflector is 130 mm,the magnetic flux density at the mirror bottom only reaches 10^(–4) T.Similarly,as

关 键 词：聚焦镜 电子偏转器 磁场 偏转效率 形变 

分 类 号：TH751[机械工程—仪器科学与技术]