论文标题
在暗场X射线显微镜中模型对比的几何光学形式主义
Geometrical Optics Formalism to Model Contrast in Dark-Field X-ray Microscopy
论文作者
论文摘要
暗场X射线显微镜是一种新的全场成像技术，它非破坏性地绘制了三维中深层嵌入的晶体元素内部内部的结构和局部应变。将物镜放置在衍射光束中会产生局部体积的放大投影图像。我们提供基于衍射成像的几何光学器件的一般形式主义，对任何晶体学空间群都有效。这允许基于微机械模型模拟衍射图像。我们向形式主义介绍了示例模拟，展示了它如何用于设计新实验或解释现有实验。特别是，我们展示了对实验设计的修改如何定制互惠空间分辨率函数以绘制变形梯度张量的特定组件。形式主义支持多长度量表实验，因为它使DFXM与3DXRD连接。通过与直脱位周围的应变场的实验图像进行比较，可以证明形式主义。
Dark-field X-ray microscopy is a new full-field imaging technique that nondestructively maps the structure and local strain inside deeply embedded crystalline elements in three dimensions. Placing an objective lens in the diffracted beam generates a magnified projection image of a local volume. We provide a general formalism based on geometrical optics for the diffraction imaging, valid for any crystallographic space group. This allows simulation of diffraction images based on micro-mechanical models. We present example simulations with the formalism, demonstrating how it may be used to design new experiments or interpret existing ones. In particular, we show how modifications to the experimental design may tailor the reciprocal-space resolution function to map specific components of the deformation gradient tensor. The formalism supports multi-length scale experiments, as it enables DFXM to be interfaced with 3DXRD. The formalism is demonstrated by comparison to experimental images of the strain field around a straight dislocation.
