Introduction to Micro X-ray Computed Tomography
Micro X-ray Computed Tomography (Micro-CT) or X-ray microtomography is an X-ray transmission-based technology to create cross-sections imaging of a sample and its corresponding 3D model with micrometer resolution. The incident X-ray beam penetrates the sample and is attenuated. The transmitted beam excites the scintillator located at the end of its optical path, resulting in visible light signals which is then magnified and collected by the digital camera as projection images. After the sample rotates through 180° or 360° with a specific step size, the entire collection of projection images at different degrees are mathematically processed via reconstruction algorithms to derive 3D image information. This volume can be visualized and segmented into the sample's different components for further analysis. Unlike commercial lab facilities that use polychromatic cone or fan beams, synchrotron-based micro-CT utilizes monochromatic parallel beam, leading to more feature visibility and even tunable sensitivity to different elements.