小型化矩形离子阱捕获能力的仿真研究

Simulated study on ion trapping efficiency of miniature rectangular ion trap

基于SIMION 7.0离子光学仿真软件对设计的矩形离子阱(RIT)的离子捕获效率进行了仿真,研究了离子初始位置和射频电压、频率对离子捕获效率的影响。仿真结果表明,只有初始位置靠近RIT中心的离子才能被有效捕获到。针对常见毒品及爆炸物所在的质量范围,对于内建电场空间尺寸为10mm×8.4mm×44mm(x,y,z)的RIT,选择捕获射频电压为50V0-p～100V0-p、频率1MHz时,既能保证较高的离子捕获效率,同时也降低了对电路系统指标的要求。

The ion trapping efficiency of a miniature rectangular ion trap（RIT） was studied by simulation based on SIMION 7.0 ion optical simulation software.The effects of initial ion position,RF voltage and frequency on ion trapping efficiency were investigated.The simulation results showed that only ions generated near the center of RIT could be trapped successfully.For a RIT with inner field dimensions of 10mm×8.4mm×44mm（x,y,z）,the trapping RF voltage of 50Vo-p^100Vo-p and RF frequency of 1MHz will ensure higher trapping efficiency for testing common drugs and explosives,at the same time the requirement on electronics can be reduced.