Synchrotron radiation dual-energy CT based on Laue crystal diffraction spectroscopy

Dual-energy CT (DECT) is an important X-ray imaging characterization method that enables 3D imaging of element distribution from micrometer to nanometer scale. However, acquiring DECT data in a single scan with synchrotron radiation is challenging. This study exploits the coexistence of fundamental wave and higher harmonics in the diffracted beam of a double-crystal monochromator. In addition, variations in diffraction bandwidths across different lattice planes are considered. By controlling the detuning angle of the Laue crystal after monochromatization, two spatially separated beams with energy disparity are generated. A sample was placed in the resulting overlapping light field, resulting in spatial differentiation and 3D reconstruction of two different elements. The measured diameters of nickel and silver wires closely match their actual values. Compared to the 3D result at 12 keV, the 36 keV demonstrates significant improvements in reducing metal artifacts. This method provides a solution for elemental resolution and simultaneous sampling, and extends the applications of synchrotron radiation in materials and biomedicine.