Abstract: A double-electrostatic probe system has been established to measure the electron temperature and electron number density in a 1 kW-class arcjet thruster plume. The distributions of the electron temperature and electron number density along the plume axial and radial directions, and their variations with arc current and gas flow rate have been obtained. Experimental results show that the arcjet plume deviates evidently from the LTE state, and the electron temperature shows complicated distributions and variational trend.The electron temperature along the plume axis is lower than those off the axis, while the electron number density decreases monotonically from the plume axis to the edge. The electron temperature at the plume axis decreases with increasing arc current, while the electron number density at the plume axis increases with increasing arc current. Variations of the electron temperature at the plume center region with the gas flow rate are not clearly observed.

Key words: Arcjet thruster; Plume; Double-electrostatic probe; Electron temperature; Electron number density

摘要： 研制了一套双静电探针测量系统,对以氩气为推进剂的1kW级电弧加热发动机羽流进行了测量,得到了电子温度和电子数密度的轴向和径向分布,以及随弧电流、气流量的变化趋势。结果表明,羽流显著偏离局域热力学平衡状态,电子温度呈现复杂的分布和变化趋势。羽流轴线上的电子温度明显低于偏离轴线处的值,而电子数密度远高于偏离轴线处的值；羽流轴线上的电子温度随弧电流的增加而降低,电子数密度随弧电流的增加而增加；羽流中心区电子温度随气流量的变化趋势不明显。

关键词: 电弧加热发动机;羽流;双静电探针;电子温度;电子数密度