中文摘要：

为了改善会切磁场推力器在低功率下对中低等流量变化的不适应性,采用了一种渐扩的变截面通道设计来提升推力器中低等流量下的性能,对比了两种等截面通道与一种渐扩通道在中低等流量下的性能。虽然渐扩通道与小直径的等截面通道相比,会略微降低通道内的原子密度,但渐扩通道由于减小了出口离子能量损失,同时增大磁镜比促进电离,从而能够提升推力器在同等推力水平下的效率。而大直径等截面通道和小直径等截面通道分别由于原子密度过低及壁面损失较大,性能均不如渐扩通道。因此,渐扩型变截面通道在中低等流量变化范围内具有更优的性能,这对推力器性能的进一步优化具有重要意义。

英文摘要：

The adaptability of cusped field thruster changes with different operating conditions,especially with different efficiencies,which changes a lot at different gas flow rates.To overcome this problem,a diverging variable-cross-section channel was proposed to improve the performance of cusped field thrusters at low and middle gas flow rate.Meanwhile, two constant-section channels with a big diameter and a small diameter respectively were introduced to be compared with the diverging channel. Although the diverging channel may cause a little decline in the atom density compared to the smallconstant-section channel,the diverging channel improves the efficiency at both low and middle gas flow rates on the premise of providing a considerable thrust,because it decreases the energy loss of ions at exit and promotes ionization by improving the magnetic mirror ratio.In comparison,both the big constant-section channel and the small constant-section channel have low performances due to a lower density of gas and a bigger wall loss.Therefore,a diverging channel is beneficial to improving the performance of a cusped field thruster at low and middle gas flow rate.