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针对双级加速离子光学系统的设计,开展了栅极几何参数对离子光学系统性能影响的研究。采用质点网格法和蒙特卡罗碰撞法开展栅极关键几何参数对束流引出能力、束流发散角、交换电荷(CEX)离子的截获影响规律研究;另外,还开展了不同比冲下束流发散角、碰撞交换电荷离子的变化趋势研究。研究结果表明,屏栅孔径对束流引出能力、束流发散角、CEX离子截获电流以及鞍点电势都有影响,随着屏栅孔径的增加,束流引出能力、束流发散角和鞍点电势呈上升趋势。加速栅孔径的变化对CEX离子得能量分布有影响,随着加速栅孔径的增大,截获的高能CEX离子逐渐减少,而随着加速栅厚度的增加,束流发散角、CEX离子的截获数量和能量呈上升趋势。在8000s比冲下,加速级间距的改变对束流引出能力影响较小。另外,比冲对离子光学系统性能也有影响,比冲越高,束流发散角越小,且加速栅截获的CEX离子也越少。
Aiming at the design of two-stage accelerated ion optical system, the influence of grid geometry on the performance of ion optical system is studied. The effects of key geometric parameters of grid on the extraction ability of beam current, beam divergence angle and the interception of exchange charge (CEX) ion were investigated by using the particle grid method and the Monte Carlo collision method. In addition, Study on the Changing Tendency of Charged Ion with Collision Exchange Angle. The results show that the aperture of the screen affects the beam extraction ability, beam divergence angle, CEX ion interception current and saddle point potential. With the increase of the aperture of the grid, the beam extraction ability, beam divergence angle and saddle point potential Upward trend. The change of aperture of accelerating grid has influence on the energy distribution of CEX ion. With the increase of the aperture of accelerating grid, the energy of intercepted high-energy CEX ions gradually decreases. With the increase of acceleration grid thickness, the beam divergence angle, the number of intercepted CEX ions And energy is on the rise. In the 8000s than the red, acceleration level spacing changes on the beam extraction ability less affected. In addition, the specific impulse also has an impact on the performance of the ion optical system. The higher the specific impulse, the smaller the divergence angle of the beam and less the CEX ions intercepted by the acceleration gate.