高功率微波传输通道击穿诊断研究

Diagnostic Research on Vacuum Breakdown in High Power Microwave Transmission Waveguide

高功率微波(HPM)器件在强电磁场作用下的击穿是限制HPM系统功率容量的主要因素之一,是HPM技术进步的瓶颈和国际性的技术挑战。本文开展了纳秒脉冲宽度、吉瓦高功率微波传输通道内击穿发光诊断实验,通过纳秒级响应的四分幅ICCD相机和光电倍增管研究了等离子体可见光和X射线发射的时间及空间发展规律。实验发现HPM通道在传输纳秒微波脉冲时有大量可见光,可能的原因是HPM源的乏电子束轰击收集极的金属表面轫致辐射连续谱的光子在波导内多次反射的结果。通过光电倍增管探测了微波源X射线幅度分布,确认了收集极存在较高能量X射线的结果。

The vacuum breakdown in high power microwave （HPM） devices in strong electromagnetic field is one of the main factors limiting the power capacity of HPM systems, and it is also an international technical challenge and the bottleneck in HPM technology progress. The plasma discharge of nanosecond and giga-watt HPM pulse in transmission waveguides was studied. By using nanosecond response four-frame intensified charge-coupled device and photomultiplier tube, temporal and spatial rules between the plasma visible light and X-ray emission was investigated. The experiments showed that intense visible light was discovered in waveguide during the transmission of nanosecond HPM pulse. A possible reason is that the spent electron beam of HPM source bombards the metal surface of the collector which generates continuous-spectrum photons by Bremsstrahlung Radiation, and the photons are reflected repeatedly in the channel leading to the bright visible light. Using the photomultiplier tube, the X-ray amplitude distribution of the HPM source was detected which confirmed the existence of high energy X-ray on collectors.