Abstract: In view of the focused ion beam of Hall thrusters, a method for fast measuring and calculating the plume divergence angle with a directional probe in the near-field region is proposed.The distribution and diffusion of the ion beam density can be also obtained through the measurement. The uncertainty analysis shows that the deviation of plume divergence angle obtained with this method mainly comes from the radial cut of measured ion current. However, when the probe position is chosen appropriately for a focused ion beam, the measurement uncertainty can reach ±1% of the minimum.

Key words: Hall thruster; Plume divergence angle; Directional probe; Uncertainty

摘要： 针对霍尔推力器的聚焦型束流,提出了一种利用定向探针在近场区快速测算羽流发散角的方法,并且还能获到喷口附近离子通流密度的分布及扩散特性。不确定度分析显示,利用该方法计算羽流发散角的偏差来源主要是离子电流的径向截断,但对于聚焦型等离子体束流在合理选择测量位置的情况下,其测算不确定度最小可达到±1%。

关键词: 霍尔推力器;羽流发散角;定向探针;不确定度