Monochromatic computed tomography using laboratory-scale setup: proof-of-concept

TL;DR

This paper demonstrates a laboratory-scale method for monochromatic X-ray absorption tomography that can map and distinguish chemical states in 3D, enabling detailed material analysis with low-brilliance sources.

Contribution

It introduces a novel proof-of-concept technique for chemical state tomography using a conventional X-ray tube, expanding capabilities for materials and biological research.

Findings

Successful 3D mapping of selenium in different oxidation states

Distinguished chemical states using absorption edge contrast

Applicable to mm-scale samples with low-brilliance X-ray sources

Abstract

In this article, we demonstrate the viability of highly monochromatic full-field X-ray absorption near edge structure based tomography using a laboratory-scale Johann-type X-ray absorption spectrometer based on a conventional X-ray tube source. In this proof-of-concept, by using a phantom embedded with elemental Se, Na$_2$SeO$_3$, and Na$_2$SeO$_4$, we show that the three-dimensional distributions of Se in different oxidation states can be mapped and distinguished from the phantom matrix and each other with absorption edge contrast tomography. The presented method allows for volumetric analyses of chemical speciation in mm-scale samples using low-brilliance X-ray sources, and represents a new analytic tool for materials engineering and research in many fields including biology and chemistry.