基于同步辐射光源的扫描菲涅耳相干衍射成像方法学研究

项目名称： 基于同步辐射光源的扫描菲涅耳相干衍射成像方法学研究

项目编号： No.11505277

项目类型： 青年科学基金项目

立项/批准年度： 2016

项目学科： 数理科学和化学

项目作者： 刘海岗

作者单位： 中国科学院上海应用物理研究所

项目金额： 23万元

中文摘要： 相干衍射成像技术是一种新型的、有效的对材料和生物样品进行二维、三维纳米级分辨成像的显微技术。采用第三代同步辐射光源的扫描相干衍射成像技术具有强穿透性、超高分辨率和大面积快速成像等优势，是当前及未来X射线成像领域一个重要的发展方向。鉴于该成像技术的重要应用及国内在该领域研究相对滞后，本项目旨在上海光源软X谱学显微线站（STXM）开展X射线扫描菲涅耳相干衍射成像方法学研究及应用。研究实验平台搭建，合理选择实验条件快速开展实验。优化编写的位相重建算法，快速重建出纳米分辨率的样品图像。研究在CCD前加装挡光板延长曝光时间，提高对高频信号的采集能力，从而提高成像分辨率。研究扫描相干衍射成像的三维成像技术。配合使用STXM成像模式和扫描相干衍射成像技术对实际样品进行二维、三维成像应用研究，包括元素分布成像及谱学分析。

中文关键词： 扫描相干衍射成像；高分辨X射线成像；相位恢复；显微成像技术

英文摘要： The coherent diffractive imaging (CDI) method is a new and powerful microscopy technique for imaging materials and biological specimens in both two and three dimensions. The scanning coherent diffractive imaging (or named ptychography) technique using third-generation synchrotron radiation sources has advantages of strong penetration ability, ultra-high resolution and large-area fast imaging and so on, which is an important development direction in x-ray microscopy field at current and in future. In view of its widely application and hysteretic research in China, this project aims to develop ptychographic coherent diffractive imaging method and its application based on soft x-ray scanning transmission microscopy (STXM) beamline in Shanghai Synchrotron Radiation Facility. Study how to construct the experimental setup, choose reasonable conditions to quickly carry out experiment. Optimize phase retrieval algorithm to reconstruct nano-resolution sample images more rapidly. Investigate adding beamstop in front of CCD detector to prolong exposure time in oder to improve the acquisition of high-frequency signal, which improve the resolution of retrieval sample images. Perform further study on three-dimensional imaging of ptychographical coherent diffractive imaging. Combination STXM and ptychography method to study application of two-dimensional, three-dimensional imaging of real samples, including elemental distribution imaging and spectroscopy analysis.

英文关键词： Ptychographic Coherent Diffractive Imaging;High-resolution X-ray Imaging;Phase Retrieval;Micro-imaging Technology