空间带电粒子对X射线通信信噪比的影响  

Effects of Spatial Electrons on Signal-Noise-Ratio of a X-ray Communication System

作　　者：李瑶 苏桐[1,2] 盛立志 强鹏飞[1,2] 徐能 李林森[1,2,4] 赵宝升 

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]中国科学院大学,北京100049 [3]西安交通大学电子与信息工程学院,西安710049 [4]西安交通大学理学院,西安710049

出　　处：《光子学报》2017年第11期76-82,共7页Acta Photonica Sinica

基　　金：国家自然科学基金(No.61471357);中国科学院"西部之光"基金资助~~

摘　　要：针对空间粒子环境对X射线通信系统的影响,分析了空间带电粒子,尤其是高能电子与X射线通信的收发天线——多层嵌套式X射线聚焦光学相互作用产生荧光X射线的过程;使用蒙特卡洛软件MCNP仿真了电子与聚焦光学相互作用,产生荧光X射线光子的量子效率;建立了电子枪与多层嵌套式X射线聚焦光学相互作用的数学模型并搭建相关实验平台,使用具有高能量分辨率的硅漂移探测器实测了荧光X射线的数量和能量分布,计算了荧光X射线光子对X射线通信系统信噪比的影响.实验与计算结果表明:在入射电子流量为1×108 cps/cm2/s量级,能量1~20keV时,X射线通信系统的信噪比优于15.1dB.多层嵌套式X聚焦光学可以有效地滤除空间电子对X射线通信的干扰,提高信号增益.A model of electron interacting with nested X-ray focusing optics was designed firstly. Then the process of electrons interacting with coating material of X-ray focusing optics and the quantum efficiency of X-ray source by using a Monte Carlo N Particle transport code was analysized. Simulation results accord well with the analyze results. Finally, a silicon drift detector, which has an energy resolution of 125 eV was used to analysis the energy spectrum in the focal point. In the detecting part, X-ray photons are composed of two parts, signal photons generated by the X ray source and noisy X-ray photons generated from nested X-ray focusing optics＇ coating material. According to different conditions of X-ray source and electron gun voltage, the number of signal photon, noisy photon and signal to noise ratio of the X-ray communication demonstration system then can be calculated. Experiment and calculate results show that nested X-ray focusing optics can effectively filter spatial particles, which will optimize the signal to noise ratio of X-ray communication system. When the number ot incident electrons is about 1×10^8 counts per second with an energy distribution from 1-20 keV, signal to noise ratio of the X-ray communication demonstration system can reach at least 15.1 dB. These results will provide foundations for optimizing the core parameters of X-ray communication system in the future.

关 键 词：X射线通信 聚焦光学 信噪比 电子枪 荧光谱线 

分 类 号：TN927[电子电信—通信与信息系统]