单色X射线光栅泰伯条纹可见度影响因素模拟研究

Numerical Investigation on Factors Affecting the Visibility of Monochromatic X-Ray Grating Talbot Self-Imaging Fringes

通过模拟单色X射线源下硅材料光栅泰伯自成像,研究振幅为均匀和高斯分布、光源尺寸与横向相干长度比值不同的单色扩展光源与金材料源光栅相结合的成像系统中光栅泰伯效应自成像条纹可见度的影响因素。计算结果表明,基于光栅的X射线相衬成像系统中光栅泰伯自成像条纹可见度主要受成像距离和光源横向相干长度影响,受单色扩展光源的振幅分布和尺寸影响很小。

By simulating silicon material grating Talbot self- imaging at the monochromatic X-ray source, the factors that influence visibility of the Talbot self-imaging fringes are researched. The imaging system is combined with gold material source and extended monochromatic light source which distributions are uniform and Gaussian, including different ratios of light source size and lateral spatial coherent length. Simulation results show that for a grating-based X-ray phase-contrast imaging system, the visibility of its Talbot self-imaging fringes is mainly determined by the imaging distance and lateral spatial coherent length of the X-ray sources, but less effected by the source size and its amplitude distribution.