Effective electromagnetic shielding with multi-layer structure material on Shenguang laser facility

Electromagnetic pulses(EMPs)with high intensity and frequency bandwidth can be generated during the intensive laser irradiating solid targets in inertial confinement fusion(ICF).To shield the EMPs radiation and hence protect various diagnostics in and outside the target chamber,we designed a multi-layer structure material to shield the EMFs and demonstrate experimentally and numerically shielding performance of the material structure.The thickness of the multi-layer structure material has a great influence on the EMPs shielding.It is shown that,with the increase of the material thickness,the better shielding performance is obtained,and the material structure with polytetrafluoroethyIene of 0.5 mm,copper of 0.4 mm and lead of 2.4 mm reduces 448 times compared the maximum value of EMPs voltage to that without shielded.The design of multilayer structure material for EMPs shielding provides a promising way to reduce EMPs radiation,which is extremely useful for the diagnostics protection and signal processing in ICF.     

用于强激光靶耦合诊断的脉冲天线

惯性约束聚变(ICF)背景下的激光靶耦合过程产生大量电磁脉冲,对诊断设备的正常运行和测试数据的采集产生不良影响,严重时甚至损害诊断装置。介绍了强激光与金属靶相互作用过程中受激辐射产生等离子体的数学模型,模拟了盘锥脉冲天线的物理模型、三维增益等各项指标,并对打靶过程进行测量,得出电磁辐射电场值,并推导出其频域分布。实验结果显示,影响电磁辐射强度的因素有激光能量、激光打靶方式和入射方向等。对于平面靶,相同靶型和靶材质情况下,不同功率激光与平面靶相互作用发出的电磁脉冲具有相似的频谱和相同的特征频率。诊断结果为激光打靶产生电磁脉冲物理机制研究提供重要实验依据。     

神光Ⅲ装置电磁脉冲测量

针对神光Ⅲ装置电磁脉冲辐射的特点,结合装置靶场特殊试验环境,设计了电磁脉冲辐射测量装置,能够捕获试验中产生的高功率超宽带瞬态电磁脉冲信号,为评估装置电磁辐射环境和开展电磁兼容研究提供了手段。     

多孔二氧化硅陶瓷介电行为的机制研究

本文通过对数学物理方法和电介质物理的结合,对影响二氧化硅的介电常数的四种极化机制和影响介电损耗的三种极化机理进行了温度分析,把多孔石英陶瓷看作是空气和石英陶瓷的混合物而建立了模型,通过带入了一些微观参数而得到介电性能与温度的变化关系,并与试验值取得了良好的一致性。