离子阱中3种软件程序的离子运动轨迹数值模拟对比

Comparison of Numerical Simulation of Ion Trajectories in Three Simulation Programs of Ion Trap

质谱仪器研发周期长、应用成本高,使得数值模拟成为仪器研发、性能优化、实验方案设计的理想选择。目前,离子轨迹模拟软件SIMION、Comsol和Axsim已广泛用于质谱数值模拟和理论研究,对比分析这3种软件对于质量分析器的设计具有重要意义。本研究以矩形离子阱质量分析器为研究对象,从图形用户界面和运行平台、电极建模和电场计算、条件定义和程序加载、离子轨迹计算和时间步长选取等方面入手,比较这3种软件的模拟过程和结果。结果表明:3种软件模拟的离子运动轨迹存在偏差,且主要位于离子运动方向转变时,Comsol与SIMION的模拟轨迹偏差最大,Axsim和SIMION模拟的频谱图中谱峰位置差异小于0.1%。SIMION软件适用于复杂质谱装置中离子运动轨迹的理论模拟,但对使用者的物理和编程水平要求较高;Comsol具有最精致的图形用户界面,以及详细的数值模拟模块,但是不具备离子运动轨迹的频谱分析、相位分析等特殊模块,而且封闭的软件程序无法根据具体情况灵活调整,所以只适用于一些简单结构的质谱数值模拟;Axsim具有最专业的质谱中离子运动轨迹分析程序,可以对离子运动的频谱、相位、空间发散、动能发散等参数进行直接分析,能够直观地指导质谱质量分析器的设计,但不具备建模和电场计算模块。本研究有助于加速质谱研究中数值模拟进程,为开发具有自主知识产权的国产质谱数值模拟软件提供参考。

Mass spectrometry has been widely used in the fields of chemistry,biology,environmental science,pharmacy,space exploration and so on.However,due to the long research and development cycle and high application cost of mass spectrometer,numerical simulation has become an ideal choice for mass spectrometer research,performance optimization and experimental scheme design.At present,three ion trajectory simulation software of SIMION,Comsol and Axsim have been widely used for numerical simulation and theoretical study of mass spectrometry.Therefore,the comparative analysis of these three software is important for the design of mass analyzer.In this study,the simulation process and simulation results of these three software programs were compared through the graphical user interface and operation platform,electrode modeling and electric field calculation,condition definition and program loading,ion trajectory calculation and time step selection,etc.It could be seen that the differences can complement and verify each other.The simulation results of the three software can be observed that the motion trajectory deviation position is mainly located in the ion motion direction change,and the deviation of Comsol and SIMION simulation trajectory is the largest.However,the difference in the positions of the spectral peaks between the Axsim and SIMION simulations is less than 0.1%.In conclusion,SIMION software is suitable for theoretical simulations of ion trajectories in complex mass spectrometry devices.Comsol has the most sophisticated graphical user interface and detailed numerical simulation modules,but it does not have special modules for spectral analysis of ion trajectories,phase analysis,etc.,and the closed software program cannot be flexibly adapted to specific situations.Axsim has the most professional ion trajectory analysis program for mass spectrometry,it can intuitively guide the design of mass analyzers,but it does not have modeling and electric field calculation modules.This study can accelerate the process of numerical simulation in mass spectrometry research,and also can provide a reference for the development of domestic mass spectrometry numerical simulation software with independent intellectual property rights.