X-ray imaging based on fluorescence spherical waves

X-ray microscopy (XRM) is an important noninvasive technique for 3D visualization of internal structures. However, achieving a large field of view, high resolution, and low-dose imaging simultaneously remains challenging. This study proposes a lensless full-field phase-contrast imaging method termed synchrotron radiation X-ray fluorescence spherical-wave imaging (SR-XFSFI). A high-flux white microbeam excites a high-purity copper target to generate quasi-monochromatic Cu K _α fluorescence spherical waves, enabling lensless geometric magnification beyond the sampling limit imposed by large-pixel detectors. Experiments demonstrate a 3 µm spatial resolution using a detector with 172 µm pixels under millisecond exposure conditions. This method enables continuously tunable magnification and cross-scale imaging of medaka fish, providing an approach for large-field-of-view, high-resolution, and low-dose X-ray imaging of radiation-sensitive samples.