基于COMSOL的星载四极质谱仪仿真分析

Simulation and Analysis of Spaceborne Quadrupole Mass Spectrometer Based on COMSOL

四极杆质谱仪应用广泛,在航天空间探测任务中也应用较多,为适应航天器平台资源需研发轻质量、小体积、低功耗的小型质谱仪,并提升质谱仪性能,确保在工程约束下获得更优参数,因此需要预先对质谱仪进行建模仿真分析和预设计。基于离子运动理论与离子碰撞理论,使用多物理场仿真软件COMSOL对电场分布与离子运动状态进行建模仿真。仿真分析结果表明,马蒂厄方程系数α由0.231增大至0.236,灵敏度降低91.3%,分辨率提高73.3%;系数q取0.706时最佳,最大离子通过率97.7%;角频率增大,灵敏度降低61.9%、分辨率提高55.6%;仪器性能在压强小于10-2Pa的真空环境下影响很小;仪器性能在-40-60℃温度范围内变化很小;针对仪器小型化,杆内切圆半径取值范围为2-4 mm;杆半径与内切圆半径比例在1.12-1.13时灵敏度最好;杆长度取值60-150 mm时灵敏度与分辨率有很好的平衡。结果表明该仿真模型能较好模拟离子运动状态,分析四极杆质谱仪性能变化,为质谱仪工程设计实现提供新思路。

In order to improve the performance of quadrupole mass spectrometer,it is necessary to model,simulate and analyze the mass spectrometer in advance to ensure better design parameters under engineering constraints.For the spaceborne quadrupole mass spectrometer,based on the theory of ion motion in quadrupole electric field and collision between ion and neutral gas,the electric field distribution and ion motion state are modeled and simulated by advanced multiphysics field simulation software COMSOL.By analyzing the simulation results,the effects of the changes of related parameters on the sensitivity and resolution of quadrupole mass spectrometer are obtained.The results show that the simulation model can well simulate the ion motion state,analyze the performance changes of quadrupole mass spectrometer,and provide a reference for the improvement of the project.