A numerical simulation has been performed to study the effect of the mismatch of layer thicknesses of multilayer Laue lenses (MLLs) on X-ray focusing. The spatial distributions of X-ray intensities in the bulk of a lens have been calculated with different gradients of the variation of the period of a MLL. It has been shown that the focal length, as well as the focal spot size, decreases with an increase in the mismatch of layer thicknesses of the MLL. The calculated focal spot size are significantly different from the values reported in other works. A physical nature of the focusing by the MLL has been revealed. It is determined by the Bragg diffraction and is not related to the configuration of the Fresnel zone plate.

中文翻译：

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层厚不匹配对多层劳厄透镜聚焦X射线的影响

进行了数值模拟，以研究多层Laue透镜（MLL）的层厚度不匹配对X射线聚焦的影响。已经用MLL周期的变化的不同梯度来计算了透镜主体中X射线强度的空间分布。已经显示，焦距以及焦斑尺寸随着MLL的层厚度的失配的增加而减小。所计算的焦点大小与其他著作中报告的值明显不同。MLL聚焦的物理性质已被揭示。它由布拉格衍射确定，与菲涅耳波带片的结构无关。