与白光X射线动态显微CT（Micro Computed Tomography）相比，单色光X射线动态显微CT具有较低的辐射损伤和较高的密度分辨率，但是更难以平衡其空间和时间分辨率。目前，单色光X射线动态显微CT的最高时间分辨率可达到13.3 Hz，探测器有效像素尺寸为5 μm。为了构建具有更高时空分辨率的单色光X射线动态显微CT系统，基于上海光源快速X光成像线站（BL16U2）的高通量密度单色光，将高速转台与三镜头大数值孔径快速X射线成像探测器相结合，构建了实验系统。以速发型聚氨酯材料为研究对象进行了验证实验，在15 keV单色光下动态显微CT的时间分辨率达到了20 Hz，探测器有效像素尺寸为2.2 μm。对气泡运动进行相关定量分析，证明该系统具有高时空分辨率和高对比度分辨率，可以对复杂运动系统进行四维时空定量分析，为BL16U2线站用户进行高时空分辨率的复杂原位研究提供了强大的实验平台。

At present, reconstruction of megapixel and high-fidelity images with few measurements is a major challenge for X-ray ghost imaging (XGI). The available strategies require massive measurements and reconstruct low-fidelity images of less than 300×300 pixels. Inspired by the concept of synthetic aperture radar, synthetic aperture XGI (SAXGI) integrated with compressive sensing is proposed to solve this problem with a binned detector in the object arm. Experimental results demonstrated that SAXGI can accurately reconstruct the 1200×1200 pixels image of a binary sample of tangled strands of tungsten fiber from 660 measurements. Accordingly, SAXGI is a promising solution for the practical application of XGI.

Carbon fiber (CF)/pyrolytic graphite (PG) composites are promising structural materials for molten salt reactors because of their superior performance. Due to the minor density difference between CF and PG, existing methods are impractical for efficient three-dimensional characterization of CF/PG composites. Therefore, in this study, a method based on in-line phase-contrast X-ray microtomography was developed to solve the aforementioned problem. Experimental results demonstrate that the method is suitable for comprehensive characterization of CF/PG composites. The relationship between the microporous defects and fiber orientations of such composites was also elucidated. The findings can be useful for improving the manufacturing process of CF/PG composites.