Determination of mobility and diffusion coefficients of Ar+ and Ar2+ ions in argon gas
Determination of mobility and diffusion coefficients of Ar+ and Ar2+ ions in argon gas
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DOI：
10.1007/s12127-020-00258-z
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发表时间：
2020-03-17
影响因子：
--
通讯作者：
Viehland, Larry A.
中科院分区：
文献类型：
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作者：
Dashdorj, Jamiyanaa;Pfalzgraff, William C.;Viehland, Larry A.
最近已经表明，精确的理论计算可以用来校准漂移管质谱仪（DTMS）测量气体离子迁移率精确到0.6%以内。在这里，我们提出了一种新的方法来校准DTMS仪器，以获得平行于电场的扩散系数，其精度在8%以内。该方法是发展和验证考虑He+（S-2（1/2））离子在He。我们应用这些技术，以确定Ar+（P-2（3/2））和Ar 2+（P-3（2，1，0））离子在Ar气体中的输运系数在300 K，与E/N的函数，静电场强度的气体数密度的比率，在30- 2,1,0 Td的范围内给出的结果。所测得的迁移率是准确的0.8%以内，为Ar+，他们同意在1.5%以内的Monte Carlo模拟，并为阳离子和dications，他们是在良好的协议与以前的测量。我们的方法给出了新的扩散系数，同意在5%以内的量子蒙特卡罗计算。
It has recently been shown that accurate theoretical calculations can be used to calibrate a drift-tube mass spectrometer (DTMS) to measure gaseous ion mobilities accurate to within 0.6%. Here we present a new method for calibrating a DTMS instrument to obtain diffusion coefficients parallel to the electric field which are accurate to within 8%. This method is developed and verified by consideration of He+ (S-2(1/2)) ions in He. We apply these techniques to determine transport coefficients for Ar+(P-2(3/2)) and Ar2+ (P-3(2,1,0)) ions in Ar gas at 300 K, with results given as a function of E/N, the ratio of electrostatic field strength to gas number density, in the range 30-210 Td. The measured mobilities are accurate within 0.8%; for Ar+ they agree within 1.5% with Monte Carlo simulations, and for both the cations and dications they are in excellent agreement with previous measurements. Our method gives new diffusion coefficients that agree within 5% with quantum Monte Carlo calculations.