Abstract: In order to study the effect of plasma contactor unit on the surface potential of the space station and the operating characteristics of the clamping mode，an experimental study on the mode of the plasma contactor unit was carried out. The plasma sheath thickness of the space station is analyzed，and the variation law of the clamping voltage and the emission current is given. The effects of vacuum degree，plasma density and xenon mass flow rate on the clamping mode and the variation of the power of the plasma contactor unit with the emission current are studied. The experimental results show that the clamping voltage of the plasma contactor unit is less than 20V at the rated operating point，with the increasing of clamping voltage，the emission current increases suddenly. Low vacuum degree，high space plasma density and high xenon mass flow rate can make the clamping mode of the plasma contactor emerge at a lower voltage，the electron emission characteristic curve of the plasma contactor moves to the left by 20%. The power of the plasma contactor unit decreases by nearly 30％ with the increase of the emission current.

Key words: Space station；Plasma contactor unit；Clamping mode；Experimental investigation

摘要： 为了研究等离子体接触器对空间站表面电位主动控制作用及钳位模式工作特性，对等离子体接触器进行了钳位模式实验研究，分析了空间站在运行轨道等离子体鞘层厚度，给出了等离子体接触器钳位电压和发射电流之间的变化规律，对真空度、等离子体密度、氙气流量等对钳位模式影响及等离子体接触器功率随发射电流变化规律进行了实验研究。实验结果表明:等离子体接触器在额定工作点下钳位电压低于20V；钳位电压增加使等离子体接触器发射电流突增；较低的真空度、较高的空间等离子体密度、较大的氙气流量会使等离子体接触器钳位模式较早出现，等离子体接触器电子发射特性曲线左移了近20％；等离子体接触器功率随发射电流增加而减小了近30％。

关键词: 空间站；等离子体接触器；钳位模式；实验研究