爱因斯坦探针后随X射线聚焦镜的粒子污染仿真  

Particle contamination simulation of Einstein probe follow-up X-ray telescope focusing mirror

作　　者：吕中华 杨彦佶[1] 祝宇轩 赵晓帆[1] 杨雄涛 陈勇[1] LüZhong-Hua;Yang Yan-Ji;Zhu Yu-Xuan;Zhao Xiao-Fan;Yang Xiong-Tao;Chen Yong(Key Laboratory of Particle Astrophysics,The Institute of High Energy Physics of the Chinese Academy of Sciences,Beijing 100049,China;University of Chinese Academy of Sciences,Beijing 100049,China)

机构地区：[1]中国科学院高能物理研究所,粒子天体物理重点验室,北京100049 [2]中国科学院大学,北京100049

出　　处：《物理学报》2023年第12期54-64,共11页Acta Physica Sinica

摘　　要：X射线聚焦镜是一种对粒子污染物颗粒极其敏感的设备,通常依靠控制地面各流程的污染物积累来限制其影响.本文根据粒子污染物的特点,结合Mie散射理论构建了聚焦镜片上的粒子污染颗粒物与入射X射线光子的相互作用模型.在此基础上,结合蒙特卡罗法进行光线追迹工作,构建出爱因斯坦探针后随X射线聚焦镜的粒子污染仿真程序.通过仿真计算得到入射X射线光子与粒子污染物相互作用时的反应截面与散射角分布函数.这两个量与粒子污染物的尺度相关联,本文将聚焦镜片样本上粒子污染颗粒尺度分布的测量结果进行拟合,得到粒子污染尺度分布.根据上述结果进行仿真计算,得到粒子污染物密度与聚焦镜的有效面积和角分辨的关系,并使用防污染监测数据和爱因斯坦探针后随X射线聚焦镜性能测试数据验证了仿真结果的可靠性.对爱因斯坦探针后随X射线聚焦镜粒子污染的仿真实现了对粒子污染物影响的定量分析,明确了粒子污染物对聚焦镜各方面性能的具体影响,为防污染工作提供了理论支持.Particle contamination can greatly affect the performance of X-ray focusing mirror.In this paper,we analyze the influence of particle contamination on X-ray focusing mirror.The model of interaction between contaminant particles and incident light is established from Mie scattering theory in the wavelength range of X-ray.And the relationship between them is mainly influenced by the complex refractive index of the particles and the scale factorα.Therefore,the reaction cross section and scattering function of particle contamination are calculated.Then,in order to obtain the effect of particle contamination on Einstein probe follow-up X-ray telescope(EP-FXT)focusing mirror,we carry out Monte Carlo simulation based on the design parameters of EP-FXT focusing mirror.Finally,the relationships among effective area,HEW,W90 and particle contamination density are calculated to characterize the influence of particle contamination on the performance of the focusing mirror.In this paper,structural and thermal model(STM)and qualification model(QM)are simulated simultaneously to make full use of their test data.By comparing the simulation results of STM effective area with the measured results,we find that the simulation results of STM effective area are accurate.When the EP-FXT is in orbit(the contamination amount is limited to less than 1.1×10-3),the effective area and angle resolution(HEW)meet the development requirements of EP-FXT.For the simulation of HEW,both QM and STM are in good agreement with the test results.The simulation results of HEW and effective area can be used to quantitatively analyze the effect of particle contamination on the performance of the focusing mirror.These quantitative analysis results provide a theoretical basis for the contamination prevention requirements of EP-FXT.

关 键 词：粒子污染 X射线聚焦镜 爱因斯坦探针 后随X射线望远镜 

分 类 号：O434.1[机械工程—光学工程] O572.2[理学—光学]