基于神光Ⅲ主机装置激光打靶产生电磁脉冲特性研究

摘要

The interaction between intensive laser and metal targets can yield an extremely significant electromagnetic radiation, which not only has a large intensity and widely bandwidth, but leads to malfunctioning of various important diagnostics systems and the inaccuracy of physical experiment result. This study focus on building a diagnostic system against and outside the target chamber and collecting the pulse signal by designing multiple antennas, which are expected to provide the experimental basis for further investigation of EMP characteristic. Different data processing methods of electric field antennas and magnetic-filed antennas are used to obtain the electromagnetic field distribution inside and outside the target chamber. Multiple data shows that large discone antenna gets the highest signal while ultra wideband dipole antenna gets the lowest signal. It is necessary to make corresponding electromagnetic shielding because the high electromagnetic interference inside and outside the target chamber.%激光打靶过程会产生大量的电磁脉冲，脉冲强度大，频带宽，会影响各种重要诊断设备的正常运行以及精密物理结果的精确测量。本实验在神光Ⅲ主机装置靶室壁和靶室外搭建诊断系统，并利用自行设计的多款天线进行脉冲信号的采集，为电磁脉冲特性的进一步研究提供了实验依据。本文分别对电场天线与磁场天线采取不同的数据处理方法以获得靶场电磁场分布，多发数据表明，大盘锥天线测得信号最强，超频段偶极天线测得信号最弱，靶室内外均产生较强的电磁干扰，需要进行相应的电磁屏蔽。