A study of the pressure profiles near the first pumping aperture in a high pressure photoelectron spectrometer
A study of the pressure profiles near the first pumping aperture in a high pressure photoelectron spectrometer
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DOI：
10.1016/j.elspec.2015.08.005
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发表时间：
2015-11-01
影响因子：
1.9
通讯作者：
Payne, David J.
中科院分区：
文献类型：
--
作者：
Kahk, J. Matthias;Villar-Garcia, Ignacio J.;Payne, David J.
在高压光电子能谱仪中，样品被放置在靠近差分泵送孔径的位置，在差分泵送孔径之后的压力比分析室中的压力低几个数量级。为了找到最佳的样品位置，其中光电子通过高压区域的路径长度尽可能地最小化，而不影响样品表面的实际压力的知识，需要了解样品和孔径附近的压力变化。已经进行了计算流体动力学研究，以检查的压力分布，并将结果与实验光谱的强度进行了分析，使用比尔-朗伯定律进行比较。所得的压力分布大致类似于先前从简单分子流模型导出的压力分布，但表明随着分析室中的压力升高，发生压降的区域逐渐变窄。(C)2015 Elsevier B. V.版权所有。
In a high-pressure photoelectron spectrometer, the sample is positioned close to a differential pumping aperture, behind which the pressure is several orders of magnitude lower than the pressure in the analysis chamber. To find the optimal sample position, where the path length of the photoelectrons through the high pressure region is minimized as far as possible without compromising knowledge of the actual pressure at the sample surface, an understanding of the pressure variations near the sample and the aperture is required. A computational fluid dynamics study has been carried out to examine the pressure profiles, and the results are compared against experimental spectra whose intensities are analyzed using the Beer-Lambert law. The resultant pressure profiles are broadly similar to the one previously derived from a simplistic molecular flow model, but indicate that as the pressure in the analysis chamber is raised, the region over which the pressure drop occurs becomes progressively narrower. (C) 2015 Elsevier B.V. All rights reserved.