用于空间X射线通信的栅极控制脉冲发射源研究

利用X射线作为载波实现空间远距离、高速率的信息传输已引起研究者的关注,这项技术的发展将对拓宽电磁波频谱的使用范围具有积极意义.针对X射线通信地面模拟真空实验系统对信号发射源的需求,设计了一种栅极控制X射线源.该X射线源是在传统X射线管的基础上,增加了电压控制栅极,通过改变栅极电压实现X射线的脉冲发射.利用三维电磁场仿真软件CST粒子工作室设计了实验样管,模拟计算了管内的电位分布、电子运动轨迹、实际焦斑大小和打靶电子数.仿真结果表明,实际焦斑大小约为0.4 mm×4 mm,栅极开启电压和截止电压分别为0和-10 V.实验测试了样管特性,测试结果与仿真结果符合得很好,并且在X射线真空实验系统中实现了数字信号传输.

Grid-controlled emission source for space X-ray communication

Using X-ray as carrier signal to realize the high rate information transmission in a distant space is attracting the attention of researchers. The development of this technology has a positive significance for broadening the scope of use of the electromagnetic spectrum. In this paper, the novel grid control X-ray source, which consists of a traditional X-ray tube and a signal control grid, is designed to meet the requirements of X-ray communication in the simulation vacuum experimental system by means of three-dimensional electromagnetic simulation software CST particle studio. The tube potential distribution, electron trajectory, actual focal spot and the number of electrons at the anode are simulated by the computer simulation software. It works by changing the grid voltage to control the X-ray pulse emission. The data of the simulation are as follows. The actual focal spot size is 0.4 mm×4 mm, the effective gate-on voltage is 0 V, and the gate-off voltage is-10 V. X-ray tube grid-controlled characteristics are tested in experiment. The test results are well consistent with the simulation results. Finally, the digital signal transmission is successfully implemented in the X-ray vacuum experiment system.
Keywords： grid control X-ray source focal spot size modulation potential digital signal transmission