Pulsed plasma thrusters (PPTs) have been widely used in space flight applications due to their low cost and robustness. Recently, it has been observed that during the operation of a PPT, the plasma plume exhibits an in-plume acceleration phenomenon where the leading-edge ions continue to accelerate in the plume even in the absence of electromagnetic forces. The physical mechanism behind the phenomenon may be ambipolar diffusion in nature. However, details regarding the propagation of electrons within the plume are still unknown. To better understand the complete plasma diffusion process, it is important to understand the behavior of both ions and electrons. To investigate this mechanism, a diagnostic method using neutral gas injection is proposed to estimate the velocity of fast electrons within the plasma plume. This is a new method where neutral gas is injected at the plasma plume edge to increase the local visible light emission and ionization rate of electrons. In addition t...

中文翻译：

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使用中性气体注入诊断脉冲等离子推进器中的离子和电子扩散

脉冲等离子推进器（PPT）由于其低成本和耐用性而已广泛用于太空飞行应用。近来，已经观察到在PPT的操作期间，等离子体羽流呈现出管内加速现象，其中即使没有电磁力，前沿离子也继续在羽流中加速。现象背后的物理机制可能是自然界中的双极性扩散。然而，关于羽内电子的传播的细节仍然未知。为了更好地理解完整的等离子体扩散过程，重要的是要了解离子和电子的行为。为了研究这种机理，提出了一种使用中性气体注入的诊断方法来估计等离子体羽流中快速电子的速度。这是一种新方法，其中在等离子羽流边缘注入中性气体以增加局部可见光发射和电子的电离速率。另外...