The objective of this study is to determine the effect of different barrier positions on the DC breakdown characteristics of liquid nitrogen (LN2), with and without bubbles. The DC breakdown voltage is measured of a needle-to-plane electrode, with 9 mm gap distance, with and without PTFE barrier insulation of 40 μm thickness. The presence of bubbles lowers the breakdown voltage and the effect of have the barrier at various distances from the tip of the needle electrode is studied. The results show that with and without bubbles, the closer the barrier to the needle electrode, the higher the breakdown voltage. Observations using a high-speed camera show that the presence of the insulation barrier triggers the breakdown of the LN2/insulation barrier composite system.

中文翻译：

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势垒位置对液氮中气泡触发直流击穿特性的影响

本研究的目的是确定不同势垒位置对液氮 (LN2) 直流击穿特性的影响，有无气泡。直流击穿电压是测量针到平面电极的，间隙距离为 9 mm，有和没有 40 μm 厚的 PTFE 隔离绝缘层。气泡的存在降低了击穿电压，并研究了在距针电极尖端不同距离处具有屏障的效果。结果表明，无论有无气泡，势垒越靠近针电极，击穿电压越高。使用高速摄像机的观察表明，绝缘屏障的存在会触发 LN2/绝缘屏障复合系统的击穿。