微型镓场发射电推力器的研制和点火特性

为了满足立方星等微纳航天器对推进系统的需求，研制出中国首台针式微型镓场发射电推力器。通过提高润湿温度解决了真空环境下镓难以充分润湿钨针等问题。实现了推力器的稳定点火，测试了不同润湿温度和不同几何参数下的点火特性。得到了发射电流随润湿温度提高、极间距减小和吸极内孔直径的增大而增大的关系。通过公式计算，给出了不同发射电流下的理论推力。通过电场仿真得到不同几何参数下的电场强度，揭示了几何参数影响发射电流的原因。

Development and ignition characteristics of miniature gallium field emission electric propulsion thruster

In order to meet the demand for propulsion systems of micro nano spacecraft such as the cubic satellite, the first needle type miniature gallium field emission electric propulsion thruster in China was developed. The problem that gallium is difficult to fully wet the tungsten needle under vacuum environment was solved by increasing the wetting temperature. The thruster′s stable ignition was realized, and the thruster′s ignition characteristics under different wetting temperatures and different geometric parameters were tested. The relationship is obtained that the emission current increases as the wetting temperature increases, the pole spacing decreases, and the inner hole diameter of absorbing pole increases. The theoretical thrust under different emission currents is given by formula calculation.The electric field strength under different geometric parameters is obtained by simulation, and the reason why the geometric parameters affect the emission current is revealed.