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X 射线双相位光栅干涉仪占空比对可见度的影响

Influence of grating duty cycle on visibility in X-ray dual phase grating interferometer

期刊信息

合肥工业大学(自然科学版),2025年12月,第48卷第12期:1665-1670

DOI: 10.3969/j.issn.1003-5060.2025.12.013

作者信息

王天祥 $ ^{1} $,王志立 $ ^{1} $,顾瑶 $ ^{1} $,陈恒 $ ^{1} $,葛昕 $ ^{2} $

(1. 合肥工业大学 物理学院, 安徽 合肥 230601; 2. 中山大学 理学院, 广东 深圳 518107)

摘要和关键词

摘要: 条纹可见度是决定 X 射线双相位光栅干涉仪应用前景的关键参数, 而光栅占空比显著影响 X 射线光栅干涉测量的条纹可见度。文章推导了单色 X 射线、任意占空比以及多色 X 射线、任意占空比的对称双相位光栅干涉仪的条纹强度表达式, 并通过数值计算分析光栅占空比对 X 射线双相位光栅干涉仪条纹可见度的影响。结果表明: 对于实验上常用的双 $ \pi/2 $ 相位光栅情形, 在单色照明和多色照明下, 光栅占空比为 2/3 的条纹可见度比光栅占空比为 1/2 的分别高 83%、77%; 且在给定的系统参数下, 总能找到最佳的占空比使双相位光栅干涉仪条纹可见度达到最大。文章研究结果可以为 X 射线双相位光栅干涉仪的性能优化提供一定的指导。

关键词: X射线成像;光栅干涉仪;条纹可见度;占空比

Authors

WANG Tianxiang $ ^{1} $, WANG Zhili $ ^{1} $, GU Yao $ ^{1} $, CHEN Heng $ ^{1} $, GE Xin $ ^{2} $

(1. School of Physics, Hefei University of Technology, Hefei 230601, China; 2. School of Science, Sun Yat-sen University, Shenzhen 518107, China)

Abstract and Keywords

Abstract: In X-ray dual phase grating interferometer, the fringe visibility has always been a figure of merit to determine its application prospects. Meanwhile, in X-ray grating interferometry, the fringe visibility can be significantly improved by optimizing the grating duty cycle. This paper presents simplified expression of intensity fringes in a symmetric geometry with an arbitrary grating duty cycle. The monochromatic illumination is considered firstly, and then the polychromaticity of the X-ray beam is taken into account. The influence of the grating duty cycle on the fringe visibility in X-ray dual phase grating interferometer is analyzed by numerical calculation. Results show that in case of a $ \pi/2 $ phase shift, the fringe visibility with a grating duty cycle of 2/3 is 83% and 77% higher than that with a grating duty cycle of 1/2 under monochromatic and polychromatic illumination, respectively. Under a given set of system parameters, one can always find an optimal duty cycle to maximize the fringe visibility. The presented results can be used as guidelines for further optimizations of X-ray dual phase grating interferometers.

Keywords: X-ray imaging; grating interferometer; fringe visibility; duty cycle

基金信息

安徽省自然科学基金资助项目(2208085MA18)

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