高总冲微阴极电弧推力器实验研究

Performance Investigation of High-Total-Impulse Micro-Cathode Arc Thruster

关键词:  微阴极电弧推力器  高总冲  推力测量  真空电弧  放电参数

Key words:  Micro-cathode arc thruster  High total impulse  Thrust measurement  Vacuum arc  Discharge parameter

摘要:

为提高微阴极电弧推力器（μCAT）的总冲，本文提出了一种圆柱形推力器结构设计，增加了推进剂的填充空间。由于结构发生了较大的变化，本文对新型μCAT在不同工作点下的性能进行了研究。在实验工作中采用扭摆测力台架测量实际推力，采用了数字滤波的方法消除了推力器点火对测力台架传感器信号的干扰。本研究使用了新研制的大功率可调电源，测试了电源功率、放电频率、外加磁场强度对推力的影响，探究了铜、钨、钼阴极的特性。当输入功率较小时，铜是理想的阴极材料，且该条件下，对于这三种金属，推力与放电频率均呈负相关性。可通过外加磁场增加圆柱形μCAT的推力，但是采用钼阴极时，过高的磁感应强度会造成推力下降。

Abstract:

In order to increase the total impulse of micro cathode arc thruster （μCAT）， this paper proposes a cylindrical thruster structure design， which increases the filling of the propellant. Due to the great changes in the structure， the performance of the new μCAT at different operating points is studied. In the experimental work， the thrust is measured by the torsion pendulum thrust stand， and a digital filtering method is used to reduce the interference of thruster ignition on the sensor signal of the thrust stand. In this study， a newly developed high-power and adjustable power supply was used to test the influence of power supply， discharge frequency and external magnetic field strength on the thrust， and the characteristics of cathodes made of copper， tungsten， and molybdenum were explored. When the input power is small， copper is an ideal cathode material. And the thrust is negatively correlated with the discharge frequency for the three tested metals. The thrust of cylindrical μCAT can be increased by applying external magnetic field； however， when the molybdenum cathode is used， the overhigh magnetic induction will cause the thrust to decrease.