High-voltage picosecond breakdown of an atmospheric-pressure air-filled coaxial line in the radial electric field of a propagating transverse electromagnetic wave has been studied both experimentally and theoretically. On the one hand, we demonstrate that gas preionization by runaway electrons (RAEs) plays a decisive role in the breakdown development process: the breakdown delay time drastically increases in the absence of RAEs. On the other hand, it is established that, for sufficiently short pulses, the radial gap switching process does not have enough time to develop even in a situation where the RAE flow is effectively generated. Fundamental limitations on the breakdown strength of gas coaxial feeders imposed by this effect are discussed.

已经通过实验和理论研究了大气中充气的同轴线在传播的横向电磁波的径向电场中的高压皮秒击穿。一方面，我们证明了逃逸电子（RAE）引起的气体预电离在击穿发展过程中起着决定性的作用：在没有RAE的情况下，击穿延迟时间急剧增加。另一方面，可以确定的是，对于足够短的脉冲，即使在有效地产生RAE流的情况下，径向间隙切换过程也没有足够的时间来发展。讨论了这种效应对气体同轴给料器击穿强度的基本限制。