小型化离子漏斗设计与仿真

Design and Simulation of the Miniaturized Ion Funnel

离子漏斗是一种新型的离子传输装置,可在高气压下聚焦离子,大幅提高离子的传输效率。针对经典离子漏斗几何尺寸较大的问题,设计了一种小型化离子漏斗。通过优化电极间距等几何参数对其离子传输性能进行优化,采用电场模拟软件SIMION和离子轨迹仿真软件AXSIM,对具有不同几何参数的小型化离子漏斗进行了模拟。模拟结果表明:在离子漏斗电极厚度为0.5 mm的情况下,当电极间距为1.6 mm时,离子的传输效率达到最高。进一步研究了电参数对小型化离子漏斗性能的影响。结果表明:在射频频率为0.5 MHz、射频电压为100 V且直流电压梯度为9.1 V/cm时,该漏斗对于质荷比大于100 Da的离子传输效率达到95%。经优化后的小型化离子漏斗总体外形为圆柱结构,其长度和径向直径均小于36 mm,可用于小型化质谱仪的开发。

Ion funnel is a new type of ion transmission device which greatly improves ion transmission efficiency due to its effectiveness of ion focusing in high atmospheric pressure region. The classical ion funnelis relatively in larger sizes,aiming at this disadvantage,a miniaturized ion funnel has been designed. Through optimizing the geometric parameters,such as the electrode spacing,the ion transmission efficiency is optimized. The electric field simulation software SIMION and ion trajectory simulation software AXSIM are used to simulate the miniaturized ion funnels with different geometric parameters. The simulation results show that when the ion electrode thickness is 0. 5 mm and the electrode spacing is 1. 6 mm,the ion transmission efficiency reaches the maximum. The effect of electrical parameters on the performance of miniaturized ion funnelis is further studied,and simulation results show that when radio frequency（ RF） is 0. 5 MHz,RF amplitude is 100 V,and DC voltage gradient is 9. 1 V/cm; high transmission efficiency is closed to 95% for ions with mass to charge ratio greater than 100 Da. The optimized miniaturized ion funnel generally has a cylindrical structure,and its length and radial diameter are both less than 36 mm,which can be used in development of miniaturized mass spectrometer.