The plasma flow parameters of nanosecond vacuum flashover were examined in detail. It was found that high-velocity ion flow could be obtained using significantly more compact and cheap equipment than that used earlier. These new results will be useful to the design of new type compact plasma thrusters. It was proven that the plasma charge composition is formed at the low-voltage phase of vacuum discharge. After the analysis of experimental data, there was not found any clear dependence of the ion spectra and the degree of ionization on the flashover amplitude. The ion flow propagates in wide solid angle (up to 60°) and the ion-energy spectra contain several local maxima. The maxima positions coincide for different charge states of ions. The coincidence can be explained by the formation of plasma waves in the ion flow. The strong dependence of maximum and average ion energies on an ion charge was found. When the short interelectrode gap was used in the vacuum arc, discharge occurred at high-current discharge mode (>200 A), leading to a metal electrode consumption. A plasma acceleration model based on the occurrence of ion-acoustic shock waves was proposed.

中文翻译：

---

脉冲真空闪络放电的离子流参数

详细研究了纳秒真空闪络的等离子体流动参数。发现使用比以前使用的设备明显更紧凑和便宜的设备可以获得高速离子流。这些新结果将有助于设计新型紧凑型等离子体推进器。已证明等离子体电荷成分是在真空放电的低电压阶段形成的。经过对实验数据的分析，没有发现离子谱和电离度对闪络幅度有明显的依赖性。离子流以宽立体角（高达 60°）传播，离子能量谱包含几个局部最大值。对于不同的离子电荷状态，最大值位置一致。这种巧合可以通过离子流中等离子体波的形成来解释。发现了最大和平均离子能量对离子电荷的强烈依赖性。当在真空电弧中使用短极间间隙时，在大电流放电模式（>200 A）下发生放电，导致金属电极消耗。提出了一种基于离子声冲击波发生的等离子体加速模型。