不同磁感强度下LIPS-200离子推力器放电室性能的研究

离子推力器放电室内永久磁铁产生的磁场大小及分布对提高放电室放电效率和约束等离子体起着非常重要的作用。利用离子推力器性能模型并结合试验测得的束流离子生产成本，分析放电室内磁感强度大小对LIPS-200离子推力器放电室性能的影响。数值计算结果显示永久磁铁厚度增加1mm，放电室内的磁感强度从原来的5．0×10^-3～3．0×10^-2T增加至1．0×10^-2-5．0×10^-2T。理论分析结果显示磁感强度增加50％，原初电子平均约束时间增加49．9％、原初电子和中性气体之间的碰撞概率增加6．9％、离子损耗减小64％、束流离子生产成本降低18．1％、推进剂利用率提高7．4％。放电损耗、推进剂利用率与磁感强度大小呈线性关系。该研究能够为今后离子推力器设计提供一定的参考。

THE STUDY OF THE EFFECT OF MAGNETIC FIELD STRENGTH ON THE PERFORMANCE OF THE LIPS-200 ION THRUSTER

The magnetic field strength directly influences the probability of the primary electrons making a collision before being lost to the anode. Based on the analytical discharge performance model and the experimental values of the beam ion energy cost, The artide considers that only by changing the magnetic field strength to improve the performance of the ion thruster, while keeping the LIPS-200 configuration and operation parameters unchanged. The results show that reducing the size of the magnet for 1 mm, the magnetic density flux contour in the discharge chamber would be changed and the strength of the magnet transforms from the 5.0×10^-3 - 3.0×10^-2 T to 1.0×10^-2 -5.0×10^-2 T. By increasing the strength50% , the mean time for a primary electron wouldbe decreased by 49.9% , the probability of collision between the primary electrons and neutrals would be increased by 6.9% , the loss rate of the ion would be reduce by 64% , the beam ion energy cost would be decreased by 18.1% , and the propellant utilization would be improved by 7.4%. The results can provide reference and reference value in the future development of the performance analysis of ion thruster.