A deterministic model of electron transport for electron probe microanalysis

15th European Workshop on Modern Developments and Applications in Microbeam Analysis; 7th Meeting of the International union of Microbeam Analysis Societies

材料科学;物理学

Bünger, J.^1 ; Richter, S.^2 ; Torrilhon, M.^1

RWTH Aachen University, Centre for Computational Engineering Science (MathCCES), Schinkelstrasse 2, Aachen

52062, Germany^1

RWTH Aachen University, Central Facility for Electron Microscopy (GFE), Ahornstrasse 55, Aachen

52074, Germany^2

关键词: Complex materials;    Deterministic approach;    Deterministic modeling;    Deterministic models;    Electron transport;    Electron transport equation;    Multi-layered structure;    Spatial resolution;   

Others  :  https://iopscience.iop.org/article/10.1088/1757-899X/304/1/012004/pdf
DOI  :  10.1088/1757-899X/304/1/012004

学科分类：材料科学（综合）

来源: IOP

【 摘 要 】

Within the last decades significant improvements in the spatial resolution of electron probe microanalysis (EPMA) were obtained by instrumental enhancements. In contrast, the quantification procedures essentially remained unchanged. As the classical procedures assume either homogeneity or a multi-layered structure of the material, they limit the spatial resolution of EPMA. The possibilities of improving the spatial resolution through more sophisticated quantification procedures are therefore almost untouched. We investigate a new analytical model (M1-model) for the quantification procedure based on fast and accurate modelling of electron-X-ray-matter interactions in complex materials using a deterministic approach to solve the electron transport equations. We outline the derivation of the model from the Boltzmann equation for electron transport using the method of moments with a minimum entropy closure and present first numerical results for three different test cases (homogeneous, thin film and interface). Taking Monte Carlo as a reference, the results for the three test cases show that the M1-model is able to reproduce the electron dynamics in EPMA applications very well. Compared to classical analytical models like XPP and PAP, the M1-model is more accurate and far more flexible, which indicates the potential of deterministic models of electron transport to further increase the spatial resolution of EPMA.