Diffraction of high-energy X-rays produced at synchrotron sources can provide rapid strain measurements, with high spatial resolution, and good penetrating power. With an uncollimated diffracted beam, through thickness averages of strain can be measured using this technique, which poses an associated rich tomography problem. This paper proposes a Gaussian process (GP) model for three-dimensional strain fields satisfying static equilibrium and an accompanying algorithm for tomographic reconstruction of strain fields from high-energy X-ray diffraction. We present numerical evidence that this method can achieve triaxial strain tomography in three-dimensions using only a single axis of rotation. The method builds upon recent work where the GP approach was used to reconstruct two-dimensional strain fields from neutron based measurements. A demonstration is provided from simulated data, showing the method is capable of rejecting realistic levels of Gaussian noise.

中文翻译：

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基于高能 X 射线衍射的三轴应变断层扫描的贝叶斯方法

同步加速器源产生的高能 X 射线的衍射可以提供快速应变测量，具有高空间分辨率和良好的穿透能力。对于未准直的衍射光束，可以使用这种技术测量应变的厚度平均值，这会带来相关的丰富断层扫描问题。本文提出了一种用于满足静态平衡的三维应变场的高斯过程 (GP) 模型和一种用于从高能 X 射线衍射中重建应变场的伴随算法。我们提供了数值证据，表明该方法可以仅使用单个旋转轴在三维中实现三轴应变断层扫描。该方法建立在最近的工作基础上，其中 GP 方法用于从基于中子的测量中重建二维应变场。