Radio frequency (RF) breakdown can result in pulse shortening and severely limits the performance of the relativistic backward wave oscillator (RBWO). In this study, segmented slow-wave structure (SWS) rings, which can be observed directly using a scanning electron microscope without any post-processing, are used to study the breakdown in a RBWO. After undergoing high-power microwave experiments, the working surface of the SWS rings was found to exhibit corrugated morphologies at the sub-mm to mm scale, and a large number of craters in the vicinity of the corrugated morphologies and a mass of scattered droplets were visible on the surface. It was deduced that the unusual morphologies resulted from electron bombardment of the working surface. The observed structures and droplets provide new evidence that helps to explain the mechanism for RF breakdown in the RBWO.

中文翻译：

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相对论反向波振荡器中金属表面的射频击穿机理

射频（RF）故障会导致脉冲缩短，并严重限制相对论后向波振荡器（RBWO）的性能。在这项研究中，分段的慢波结构（SWS）环可用于研究RBWO中的击穿，该环可通过扫描电子显微镜直接观察而无需任何后处理。在进行高功率微波实验后，发现SWS环的工作表面在亚毫米到毫米的范围内呈现出波纹形貌，并且在波纹形貌附近存在大量的凹坑，并且散落了大量的液滴。在表面上可见。可以推断出异常的形貌是由工作表面的电子轰击引起的。