Hard x-ray phase imaging using simple propagation of a coherent synchrotron radiation beam
Hard x-ray phase imaging using simple propagation of a coherent synchrotron radiation beam
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DOI：
10.1088/0022-3727/32/10a/330
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发表时间：
1999-05-21
影响因子：
3.4
通讯作者：
Peix, G
中科院分区：
文献类型：
--
作者：
Cloetens, P;Ludwig, W;Peix, G
在ESRF的ID19光束线上，X射线束的特别高的相干性与从样本点(0.1-1微拉德)观察到的源的小角度尺寸有关。这一特点使位相物体的成像变得极其简单，因为它使用了一种“传播”技术。所涉及的物理原理是菲涅耳衍射。同时，位相成像作为一种技术正在发展，并被用作研究光、天然或人造材料的工具，这些材料在传输的X射线束上引入了位相变化。它们包括聚合物、木材、晶体、合金、复合材料或陶瓷，表现出夹杂物、孔洞、裂缝等。可以使用过滤反投影算法对像在衰减层析成像中处理的图像或者通过类似于用于电子显微镜的重建过程从图像中检索到的相图，来执行层析三维重建。衍射(“地形”)和菲涅尔(“位相”)成像的结合导致了新的结果。
Particularly high coherence of the x-ray beam is associated, on the ID19 beamline at ESRF, with the small angular size of the source as seen from a point of the sample (0.1-1 mu rad). This feature makes the imaging of phase objects extremely simple, by using a 'propagation' technique. The physical principle involved is Fresnel diffraction. Phase imaging is being simultaneously developed as a technique and used as a tool to investigate light natural or artificial materials introducing phase variations across the transmitted x-ray beam. They include polymers, wood, crystals, alloys, composites or ceramics, exhibiting inclusions, holes, cracks,.... 'Tomographic' three-dimensional reconstruction can be performed with a filtered back-projection algorithm either on the images processed as in attenuation tomography, or on the phase maps retrieved from the images with a reconstruction procedure similar to that used for electron microscopy. The combination of diffraction ('topography') and Fresnel ('phase') imaging leads to new results.