真空高功率微波介质窗表面击穿破坏现象的研究进展

Research progress of dielectric window surface breakdown phenomena under HPM in vacuum

综述了国内外真空中高功率微波(HPM)下介质窗表面击穿问题的研究现状和进展。在介质窗表面击穿实验研究方面,介绍了国外最具代表性的研究成果,给出了介质窗材料表面及内部的破坏发展规律,并提出相应的理论模型。在理论仿真方面,重点介绍了国外在运用蒙特卡罗(Monte Carlo)程序和PIC模型对认识HPM下介质窗表面倍增放电机理上做出的突出贡献,给出了HPM下介质窗表面电子在不同影响因素下的运行状态,并提出了一个理论模型,从本质上解释了倍增电子数目和表面静电场以微波频率的2倍振荡的原因。介绍了目前几种可有效抑制介质窗表面微波击穿的技术手段。

The paper reviews the worldwide research status and progress of dielectric window （DW） breakdown in vacuum under high power microwave （HPM）. With respect to experimental studies, representative research results aboard are introduced, and the laws of breakdown development on the DW surface and inside the DW and the corresponding theoretical model are presented according to the results introduced combined with our research. With respect to theory and simulation studies, the progress aboard in understanding the mechanism of DW surface multipactor discharge under HPM is discussed, which is achieved with Monte Carlo and particle-in-cell simulations. Then along with our research, motion laws of DW surface electrons with different emission angles and microwave electromagnetic parameters are introduced, and another theoretical model is proposed, which can essentially explain why the multipactor electron number and the surface electrostatic field oscillate at a frequency twice that of the HPM. Finally, several effective DW breakdown suppression technologies are summarized.