Further clarification of streamer-induced breakdowns in liquid nitrogen has been attracting increasing attention owing to their potential applications in superconducting systems and cryoplasmas. In this work, negative streamers in microsecond discharges were investigated using a high-speed multiple-frame imaging technique. Different external voltages, gap lengths, hydrostatic pressures, and pin tips were employed to initiate various streamers, namely bush-like streamers, single pinecone-like streamers, dendritic streamers, and filamentary streamers. Furthermore, abundant hybrid streamers involving streamer transition and combination were observed. The diversity of negative streamers may be related to the pin morphology. Generally, it was found that thinner streamers, especially filamentary streamers, could take place more frequently with higher breakdown probability under stronger filed and lower pressure. However, bush-like streamers gradually played a more dominant role upon increasing the pressure, and they were unable to cause breakdown. Moreover, several intermittent weak discharges were recorded during the growth of streamers, which might be responsible for the streamer transition and propagation. Additionally, given the evolution of streamers branches after breakdown and the influence of pressure on streamers characteristics, it was speculated that high-pressure gas could be involved inside the streamers. The possible mechanism of streamer propagation and resultant breakdown were further explored based on the analysis of streamer protrusions.

由于其在超导系统和低温等离子体中的潜在应用，对液氮中流光诱导击穿的进一步澄清引起了越来越多的关注。在这项工作中，使用高速多帧成像技术研究了微秒放电中的负流光。采用不同的外部电压、间隙长度、静水压力和针尖来引发各种拖缆，即灌木状拖缆、单个松果状拖缆、树枝状拖缆和丝状拖缆。此外，还观察到了大量涉及流注转换和组合的混合流注。负流光的多样性可能与引脚形态有关。通常，人们发现较细的飘带，尤其是丝状飘带，在更强的磁场和更低的压力下，可以更频繁地发生，并具有更高的击穿概率。但是，随着压力的增加，灌木状的飘带逐渐发挥了更大的作用，并且无法造成击穿。此外，在流注的生长过程中记录了几次间歇性弱放电，这可能是流注过渡和传播的原因。此外，考虑到击穿后拖缆分支的演变以及压力对拖缆特性的影响，推测可能在拖缆内部存在高压气体。在对流注突出物的分析的基础上，进一步探索了流注传播和由此产生的击穿的可能机制。随着压力的增加，灌木状的飘带逐渐发挥了更大的作用，无法造成击穿。此外，在流注的生长过程中记录了几次间歇性弱放电，这可能是流注过渡和传播的原因。此外，考虑到击穿后拖缆分支的演变以及压力对拖缆特性的影响，推测可能在拖缆内部存在高压气体。在对流注突出物的分析的基础上，进一步探索了流注传播和由此产生的击穿的可能机制。随着压力的增加，灌木状的飘带逐渐发挥了更大的作用，无法造成击穿。此外，在流注的生长过程中记录了几次间歇性弱放电，这可能是流注过渡和传播的原因。此外，考虑到击穿后拖缆分支的演变以及压力对拖缆特性的影响，推测可能在拖缆内部存在高压气体。在对流注突出物的分析的基础上，进一步探索了流注传播和由此产生的击穿的可能机制。这可能负责流光转换和传播。此外，考虑到击穿后拖缆分支的演变以及压力对拖缆特性的影响，推测可能在拖缆内部存在高压气体。在对流注突出物的分析的基础上，进一步探索了流注传播和由此产生的击穿的可能机制。这可能负责流光转换和传播。此外，考虑到击穿后拖缆分支的演变以及压力对拖缆特性的影响，推测可能在拖缆内部存在高压气体。在对流注突出物的分析的基础上，进一步探索了流注传播和由此产生的击穿的可能机制。