X射线衍射层析术图像重构的若干影响因素研究  

Research of Several Influential Factors on Reconstruction of Three-Dimensional X-Ray Diffraction

作　　者：杨一鸣[1,2] 杜国浩[1] 谭海[1,2] 杨玉双 肖体乔[1,2] 

机构地区：[1]中国科学院上海应用物理研究所,上海201404 [2]中国科学院大学,北京100049 [3]澳大利亚联邦科学与工业研究组织

出　　处：《光学学报》2015年第12期49-59,共11页Acta Optica Sinica

基　　金：国家自然科学基金重点项目(81430087);国家自然科学基金联合重点项目(U1232205);国家973计划(2010CB834301);CAS-CSIRO国际合作项目(GJHZ1303)

摘　　要：三维X射线衍射层析术(3DXRD)是一种快速的、无损的结构表征技术,用于研究毫米尺度的多晶样品中晶粒(亚晶粒)的空间分布。基于上海光源成像线站BL13W1建立了三维X射线衍射层析术实验方法,并对图像重构中的若干影响因素进行了研究。通过椒盐噪声消除、对比度增强,有效提高了寻峰精度;利用德拜-谢勒环粗校与优值方程循环迭代细校相结合的方法,实现了衍射数据的精确校准,进一步采用并行运算,校准效率提高了4.5倍。实验结果表明,该方法可同时实现近场和远场衍射信息探测,从而获取样品中晶粒的尺寸、质心位置、晶体学取向等信息,并能够给出晶粒形变程度的定量信息。Three- dimensional X- ray diffraction（3DXRD） microscopy is a fast and nondestructive structural characterization technique aimed at studies of the spatial distribution of grains（subgrains） within millimetre-sized polycrystalline specimens. The 3DXRD method is successfully established on BL13W1 imaging beam line at Shanghai Synchrotron Radiation Facility. Several influential factors are studied during the process of data analysis.The accuracy of peak searching is improved effectively by using median filter and image enhancement. More accurate alignment can be achieved by the combination of Debye- Scherrer coarse alignment and the iteration of figure-ofmerit fine alignment. Further operation of parallel computation increases the efficiency of alignment by 4.5 times.The results show that 3DXRD can obtain both far-field and near-field diffraction information simultaneously,deriving grain information such as grain size, center-of-mass position, crystallographic orientation and the degree of grain deformation.

关 键 词：衍射 X射线衍射 晶粒重构 三维X射线衍射层析术 同步辐射 

分 类 号：O722[理学—晶体学]