A prototype of krypton Hall-effect thruster (HET) of 0.5 kW nominal power and a dedicated diagnostic system for ion current collection were designed in the laboratory of plasma space propulsion (PlaNS) of the Institute of Plasma Physics and Laser Microfusion (IPPLM) in Warsaw. The diagnostic system consisting of a collimated Faraday Cup (FC) and a Planar Probe with Guarding Ring, named also Faraday Probe (FP) was intended to capture both temporal and spatial ion current variation, allowing to analyze not only ion current dynamics locally but also to estimate the total ion current value and a plasma jet divergence. Reliable engine operation provided by stability of plasma in a discharge channel of the thruster is unambiguously reflected in the oscillations of the discharge current. The so-called breathing mode, categorized as ionization instability with frequencies in the range of 10–30 kHz, is commonly recognized in the HET’s discharge current. Rising of instabilities makes it difficult to increase the specific impulse effectively by just simply attempting to operate thruster in high-voltage regime because it may result in very irregular thruster functioning and often to ceasing of plasma. Discharge current oscillations should also be strongly reflected in the ion current. Indeed, a similar to discharge current behavior was observed in the recorded FC and FP ion current signals. By changing thruster operating conditions, like discharge voltage and magnitude of B-field, transitions between smooth and oscillating current regimes were examined. Studying the ion current dynamics seems particularly important, since it is predicted that the control of discharge instabilities may be crucial to improve the performance of HETs in the future.

在等离子体物理与激光微融合（IPPLM）研究所等离子空间推进（PlaNS）实验室设计了标称功率为0.5kW的氪霍尔效应推进器（HET）原型和离子流收集专用诊断系统。华沙。诊断系统由准直法拉第杯 (FC) 和带保护环的平面探头（也称为法拉第探头 (FP)）组成，旨在捕获时间和空间离子电流变化，不仅可以分析局部离子电流动态，还可以分析估计总离子电流值和等离子体射流发散。由推进器放电通道中等离子体的稳定性提供的可靠发动机运行明确反映在放电电流的振荡中。所谓的呼吸模式，被归类为频率在 10-30 kHz 范围内的电离不稳定性，通常在 HET 的放电电流中被识别。不稳定性的增加使得仅仅尝试在高压状态下操作推进器就难以有效地增加比冲，因为它可能导致非常不规则的推进器运行并且经常导致等离子体停止。放电电流振荡也应强烈反映在离子电流中。事实上，在记录的 FC 和 FP 离子电流信号中观察到类似于放电电流的行为。通过改变推进器的操作条件，如放电电压和 B 场的大小，检查了平滑和振荡电流状态之间的过渡。研究离子流动力学似乎特别重要，