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arXiv · 1911.11599

On electron imaging of small molecules, Part I: relative roles of multiple scattering and Fresnel diffraction

T. E. Gureyev·H. M. Quiney·A. Kozlov·L. J. Allen
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Abstract

The relative roles of multiple electron scattering and in-molecule free-space propagation in transmission electron microscopy of small molecules are discussed. It is argued that while multiple scattering tends to have only a moderate effect in this case, the in-molecule Fresnel diffraction is likely to be significant due to the shallow depth of focus under the relevant experimental conditions. As a consequence, diffraction tomography based on the first Born or first Rytov approximation represents a more suitable method for the reconstruction of three-dimensional distribution of the electrostatic potential in this context, compared to conventional computed tomography which is intrinsically based on the projection approximation. A simplified method for diffraction tomography is proposed and tested on numerically simulated examples.

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T. E. Gureyev, H. M. Quiney, A. Kozlov, L. J. Allen. 2019-11-25. On electron imaging of small molecules, Part I: relative roles of multiple scattering and Fresnel diffraction. https://arxiv.org/abs/1911.11599

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