摘要
对离子推力器来说,加速栅的作用是提供一个负的电势壁垒,阻止下游的电子反流到放电室内部。反流电子流不仅会导致推力器能量损失,严重的甚至会导致推力器无法工作。电子反流阈值是由加速栅孔内的鞍点电势所决定的,而决定鞍点电势的因素有屏栅和加速栅的电势,屏栅和加速栅的几何结构,子离子束流的大小。推导了鞍点电热公式,采用监测屏栅电流的变化的方法,测量出反流阈值,并与理论计算值相比较。
For ion thruster,the accel grid can produce a potential barrier to stop neutralizer electrons from flowing back into the discharge chamber. The backstreaming electron current is not only a parasitic power loss , but it can damage the thruster. The back-streaming limit is determined by the ＂saddle-point＂ voltage and the factors related to the ＂saddle-point＂ including the vohage of screen grid and accelerator grid ; the structure of grids ; the beamlet current. In general, there are two methods to measure the back-streaming limit. This paper choose the method to monitor the increase in the screen power supply current as the magnitude of the accelerator grid vohage is decreased.
出处
《真空与低温》
2013年第2期105-109,99,共6页
Vacuum and Cryogenics
关键词
电推进
电子反流
鞍点电势
ion thruster
back-streaming
saddle-point voltage
