With the development of fourth‐generation synchrotron sources, coherent diffractive imaging (CDI) will be a mainstream method for 3D structure determination at nanometre resolution. The partial coherence of incident X‐rays plays a critical role in the reconstructed image quality. Here a wave optics model is proposed to analyze the effect of partial coherence on CDI for an actual beamline layout, based on the finite size of the source and the influence of the optics on the wavefront. Based on this model, the light field distribution at any plane, the coherence between any two points on this plane and CDI experiments can be simulated. The plane‐wave CDI simulation result also shows that in order to reconstruct good image quality of complex samples the visibility of the interference fringes of any two points in the horizontal and vertical directions of the incident light field at the sample needs to be higher than 0.95.

中文翻译：

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部分相干对相干衍射成像影响的波光学模型

随着第四代同步加速器源的发展，相干衍射成像（CDI）将成为确定纳米分辨率下3D结构的主流方法。入射X射线的部分相干性在重建的图像质量中起着至关重要的作用。在此，提出了一种波光学模型，用于基于源的有限大小和光学对波前的影响，分析实际光束线布局时部分相干性对CDI的影响。基于该模型，可以模拟任意平面上的光场分布，该平面上任意两点之间的相干性以及CDI实验。