Atmospheric Pressure Ion Source Development: Experimental Validation of Simulated Ion Trajectories within Complex Flow and Electrical Fields
Atmospheric Pressure Ion Source Development: Experimental Validation of Simulated Ion Trajectories within Complex Flow and Electrical Fields
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DOI：
10.1007/s13361-013-0646-5
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发表时间：
2013-10-01
影响因子：
3.2
通讯作者：
Benter, Thorsten
中科院分区：
文献类型：
--
作者：
Wissdorf, Walter;Lorenz, Matthias;Benter, Thorsten
提出了常压离子源复杂粘性流场中三维分辨离子轨迹的计算方法。模型计算通过源外壳内相对灵敏度分布的空间分辨测量进行验证，该测量称为质分析器的离子接受度分布（DIA）。在之前的工作中，我们已经表明DIA形状以及最大信号强度强烈依赖于离子源操作参数，如气体流量和温度，以及由各种源电极电位（例如，毛细管入口电位和喷雾屏蔽电位）建立的电场梯度。在所有研究的案例中，观察到不同的、可重复的，并且在某种程度上令人惊讶的DIA模式。因此，我们尝试使用经过验证的计算流动力学导出的3d速度场作为SIMION/SDS的输入参数集，以及一套用于数据分析和参数集处理的定制软件，对选定的实验操作源模式（称为操作点）进行建模。尽管系统很复杂，但建模结果与实验得到的DIA非常吻合。结果表明，SIMION/SDS结合精确的计算流体动力学（CFD）输入数据和充分的分析软件，能够成功地模拟大气压离子（API）源的工作点。这种方法在将来API源的计算机辅助设计中应该非常有用。
Three-dimensionally (3D) resolved ion trajectory calculations within the complex viscous flow field of an atmospheric pressure ion source are presented. The model calculations are validated with spatially resolved measurements of the relative sensitivity distribution within the source enclosure, referred to as the distribution of ion acceptance (DIA) of the mass analyzer. In previous work, we have shown that the DIA shapes as well as the maximum signal strengths strongly depend on ion source operational parameters such as gas flows and temperatures, as well as electrical field gradients established by various source electrode potentials (e.g., capillary inlet port potential and spray shield potential). In all cases studied, distinct, reproducible, and, to some extent, surprising DIA patterns were observed. We have thus attempted to model selected experimental operational source modes (called operational points) using a validated computational flow dynamics derived 3D-velocity field as an input parameter set for SIMION/SDS, along with a suite of custom software for data analysis and parameter set processing. Despite the complexity of the system, the modeling results reproduce the experimentally derived DIA unexpectedly well. It is concluded that SIMION/SDS in combination with accurate computational fluid dynamics (CFD) input data and adequate analysis software is capable of successfully modeling operational points of an atmospheric pressure ion (API) source. This approach should be very useful in the computer-aided design of future API sources.