激光打靶过程中的电磁脉冲特性

Electromagnetic pulse characteristic in process of laser shooting

为诊断激光打靶产生的电磁脉冲信号分布,选取环天线作为主要电磁脉冲信号采集装置,对靶室内外信号同时进行测试。从天线设计制作到天线标定,描述了脉冲诊断系统的搭建。通过对信号进行采集及处理,对比分析了靶室外、法兰口及靶室内脉冲信号的频域特性和强度。得出靶室内受到电磁脉冲辐射强度最大且频谱分布最广,其次是法兰口,靶室外电磁脉冲信号最弱。总结多次激光打靶电磁脉冲信号频域分布,可看出波峰主要出现在0.5,1.2,3GHz。电磁脉冲时域结果规律性展示出脉冲持续约100ns,因靶室内回波振荡,电磁脉冲信号于几ns处及几十ns处有较明显峰值蔟。

To capture the electromagnetic pulse(EMP)generated by the interaction between laser and target,a loop antenna(B-dot)is chosen as the main EMP signal acquisition device.The signals inside and outside the target chamber are tested simultaneously.This paper focuses on the design and fabrication of antenna and antenna calibration.An EMP diagnostic system is established.The EMP characteristics are investigated by comparing the pulse signals.It turns out that the EMP possessed maximum strength inside the target chamber,followed by the signal on the flange,and it is weakest outside the chamber.Summarizing the multiple EMP frequency spectra,we figure out the crests mainly exist at 0.5,1.2,3GHz.Time-domain EMP distributions regularly demonstrate the pulse lasts about 100 ns.In addition,the EMP signal presents obvious peak clusters at several ns and dozens of ns respectively due to the back oscillation inside the target chamber.