Monochromatic computed tomography using laboratory-scale setup.

Area of Science:

• Materials Science
• Analytical Chemistry
• Physics

Background:

• X-ray absorption near edge structure (XANES) spectroscopy is crucial for chemical state analysis.
• Tomography enables 3D imaging, but monochromatic XANES tomography often requires high-brilliance sources.
• Developing laboratory-scale XANES tomography is essential for broader accessibility.

Purpose of the Study:

• To demonstrate the feasibility of monochromatic full-field X-ray absorption near edge structure based tomography.
• To utilize a laboratory-scale Johann-type X-ray absorption spectrometer with a conventional X-ray tube source.
• To enable volumetric chemical speciation analysis in mm-scale samples.

Main Methods:

• Employed a laboratory-scale Johann-type X-ray absorption spectrometer.
• Utilized a conventional X-ray tube as the source.
• Applied absorption edge contrast tomography to a phantom with selenium compounds (elemental Se, Na2SeO3, Na2SeO4).

Main Results:

• Successfully mapped the 3D distributions of selenium in different oxidation states within a phantom.
• Distinguished between various selenium chemical states and the surrounding phantom matrix.
• Demonstrated the capability of the method using a low-brilliance X-ray source.

Conclusions:

• Highly monochromatic full-field XANES tomography is viable with laboratory-scale setups.
• This technique provides a new analytical tool for volumetric chemical speciation.
• The method has potential applications in materials engineering, biology, and chemistry.