基于高斯谢尔模型的同步辐射相干传输二维模拟及相干衰减研究

项目名称： 基于高斯谢尔模型的同步辐射相干传输二维模拟及相干衰减研究

项目编号： No.11505278

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： 滑文强

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： 随着同步辐射三代光源的发展和波荡器的大量使用，使得其产生的X射线光束的空间相干性逐渐提高，因此基于X射线相干特性的实验方法得到了快速发展，相干光束线的设计和优化也变得日益重要。然而传统同步辐射模拟软件不能有效模拟分析部分相干X射线光束在光束线中的传输特性，无法同时给出光束线中考察面上的光强分布和相干度函数。本项目拟结合基于高斯谢尔模型的解析分析和数值模拟，完成一个能模拟光束线中部分相干X射线经过自由空间和各种光学器件（引入像差粗糙等缺陷）的二维传输软件，并通过光束性质测量实验来验证模型的正确性。同时相干衰减是困扰相干光束线的另一个重要问题。本项目拟通过理论分析，结合光栅衍射测相干实验，研究光束线中粗糙光学器件振动对光束相干性的影响，明晰相干衰减现象的产生机制。本项目的实施将为同步辐射相干光束线的设计与分析提供有效工具，为保障相干光的完好传递奠定基础，对建设高性能相干光束线具有重要意义。

中文关键词： 同步辐射；光束线；部分相干；X射线光学；光栅

英文摘要： With the development of the third generation synchrotron sources and the wide employment of undulator, the available coherent output has been growing gradually. Correspondingly, the coherent X-ray techniques have quickly developed and there has been a growing focus on the design and optimization of coherent beam-line. However, the traditional software for synchrotron radiation simulation can't effectively describe the propagation properties of partial coherent synchrotron radiation through the beam-line, the beam intensity distribution and coherence properties at the investigation plane can’t be given simultaneously. This project will develop a two-dimensional simulation software for partial coherent X-ray transmission through free space and optical elements which introduced aberration and roughness in the beam-line. Meanwhile the beam properties measurement will be performed to validate the correctness of this model. At present the “decoherence” phenomenon is another vexed problem in the coherent beam-line. Its generation mechanism will be found out through theoretical analysis and validated by the coherence measurement based on grating diffraction. The implementation of this project can provide an effective tool to design and analysis the coherent synchrotron radiation beam-line, and lay the foundation for guaranteeing the intact transmission of coherent X-ray, which has great significance for the construction of high performance coherent hard X-ray beam-line.

英文关键词： Synchrotron Radiation;Beam-line;Partial Coherence;X-ray optics;Grating