Yashiro Wataru, Momose Atsushi
Opt Express. 2015 Apr 6;23(7):9233-51. doi: 10.1364/OE.23.009233.
We investigated effects of unresolvable sharp edges on images obtained in a grating-based X-ray differential phase imaging technique. Results of numerical calculations for monochromatic X-rays show that an unresolvable sharp edge generates not only differential-phase contrast but also visibility contrast. The latter shows that the visibility contrast has another major origin other than ultra-small-angle X-ray scattering (USAXS) from randomly distributed unresolvable microstructures, which has been considered the main origin for the contrast. The effects were experimentally confirmed using a synchrotron X-ray source.
我们研究了在基于光栅的X射线微分相成像技术中不可分辨的尖锐边缘对所获图像的影响。单色X射线的数值计算结果表明，不可分辨的尖锐边缘不仅会产生微分相衬度，还会产生可见度衬度。后者表明，可见度衬度有另一个主要来源，而非来自随机分布的不可分辨微观结构的超小角X射线散射（USAXS），而USAXS一直被认为是这种衬度的主要来源。使用同步加速器X射线源对这些效应进行了实验验证。
