CAJ | 학술논문

栅极热变形是影响离子推力器性能和寿命的重要因素。采用三维粒子方法对栅极系统等离子体输运过程进行模拟，对比、分析栅极热变形前后栅极系统的电子返流限制、导流系数限制、离子通过率和发散角损失。结果表明：栅极热变形增大了屏栅离子通过率和推力器推力值，并由于加速栅截止电流阈值的提高拓展了推力器工作电流区间，但电子返流阈值的明显降低对栅极系统可靠工作造成了不利影响。
책겁열변형시영향리자추력기성능화수명적중요인소。채용삼유입자방법대책겁계통등리자체수운과정진행모의，대비、분석책겁열변형전후책겁계통적전자반류한제、도류계수한제、리자통과솔화발산각손실。결과표명：책겁열변형증대료병책리자통과솔화추력기추력치，병유우가속책절지전류역치적제고탁전료추력기공작전류구간，단전자반류역치적명현강저대책겁계통가고공작조성료불리영향。
Optics thermal deformation is an important factor that impacts the performance and lifetime of ion thrusters. Al-though some theoretical research concerned with this problem was reported, its mechanism has not been fully understood. In this study, numerical investigations are performed to explain the effect of thermal deformation on the performance and lifetime of ion thrusters. The transient behavior of charged particles is calculated using a particle-in-cell simulation, while the momentum transfer collision and the charge exchange collision are calculated by means of the Monte Carlo method. Electron backstreaming restriction, perveance restriction, ions through rate, and divergence angle losses are compared and analyzed for optics deformed and undeformed. And the influence of these factors on thruster’s performance and lifetime is discussed. Results show that the ion through rate of the screen grid increases when optics begin deformed, and the thrust is slightly higher than the theoretical values predicted;the perveance threshold of the accelerator grid increases with optics haveing thermal deformation, while the crossover limit threshold is little changed, namely the thruster can be operated in conditions of a larger beam current;the electron backstreaming restriction threshold is significantly lower under a high beam current condition with optics deformed, which means that a lower accelerating gate bias is necessary to ensure thruster work. For the less obvious change of acceleratng grid current when the beam is focused, there is no more erosion and change of lifetime. Results provide a reference for the optimization design of optics and evaluation of thruster performance and lifetime.