There is no clear experimental evidence of the underlying microscopic physical mechanisms of micro-discharges directly produced in liquids. In this study, we examine shadowgraph images and plasma-induced emission (PIE) to decouple simultaneously developing dark and luminous phases of micro-discharges with nanosecond durations in liquid water. We apply diagnostics with extremely high temporal (down to 30 ps) and spatial (down to 1 μ m) resolutions to capture tiny bush-like dark filaments that expand from the anode tip together with the formation of luminous tree-like structures. For the first time, we disentangle two closely coupled dark and luminous phases of the discharge events and determine their onsets accurately with respect to the driving high-voltage (HV) pulse. The dark filaments start appearing within ∼3–4 ns after the onset of the HV pulse, and subsequently expand at a constant velocity of ∼1 × 10 5 –2 × 10 5 m s −1 , depending on the ...

中文翻译：

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消除液态水中形成的纳秒级放电的黑暗和发光阶段

没有明确的实验证据表明直接在液体中产生微放电的潜在微观物理机理。在这项研究中，我们检查了阴影图图像和等离子体感应发射（PIE），以在液态水中以纳秒持续时间同时解耦微放电的暗相和发光相。我们应用具有极高的时间（低至30 ps）和空间（低至1μm）分辨率的诊断程序，以捕获从阳极尖端扩展而形成发光树状结构的细小的灌木状暗丝。首次，我们解开了放电事件的两个紧密耦合的黑暗和发光阶段，并相对于驱动高压（HV）脉冲准确地确定了它们的开始。