A laboratory system for element specific hyperspectral X-ray imaging

Abstract

X-ray tomography is a ubiquitous tool used, for example, in medical diagnosis, explosives detection or to check structural integrity of complex engineered components. Conventional tomographic images are formed by measuring many transmitted X-rays and later mathematically reconstructing the object, however the structural and chemical information carried by scattered X-rays of different wavelengths is not utilised in any way. We show how a very simple; laboratory-based; high energy X-ray system can capture these scattered X-rays to deliver 3D images with structural or chemical information in each voxel. This type of imaging can be used to separate and identify chemical species in bulk objects with no special sample preparation. We demonstrate the capability of hyperspectral imaging by examining an electronic device where we can clearly distinguish the atomic composition of the circuit board components in both fluorescence and transmission geometries. We are not only able to obtain attenuation contrast but also to image chemical variations in the object, potentially opening up a very wide range of applications from security to medical diagnostics.

Quantitative X-ray tomography

“…It is also possible to go beyond attenuation imaging, for example to reveal the crystallographic orientation in 3D, thanks to methods such as 3D X-ray diffraction microscopy (3DXRD) and diffraction contrast tomography (DCT), or to image spatial variations in chemistry by X-ray Absorption Near Edge Structure (XANES) imaging 6 or colour imaging. 7 The review then focuses on the static analysis of 3D volumes as a basis for the quantitative characterisation of many aspects of materials microstructure using illustrative examples from the literature. In such cases it is important to identify the added value of 3D images over conventional quantitative metallography based on 2D sections.…”

A multi-technique characterization of electroless gold contacts on single crystal CdZnTe radiation detectors

“…In recent years Redlen Technologies have delivered significant improvements in the quality of travelling-heating method (THM) grown CdZnTe material, and detectors with a thickness of 15 mm have been successfully demonstrated [3]. For these reasons, there is interest in using CdZnTe to make spectroscopic x-ray imagers in the medical, security and scientific sectors [4][5][6][7][8][9][10].…”

Three-dimensional visualisation of soft biological structures by X-ray computed micro-tomography

“…Specifically, spectral CT utilises energy-sensitive detectors to measure incident X-ray photon energy in addition to the X-ray intensity as recorded by conventional detectors. These detectors either determine the energy to within a number of broad bands (bins), such as the Medipix detector (He et al, 2013), or offer much finer sampling of the energy spectrum, such as the HEXITEK hyperspectral imaging detector (Jacques et al, 2013). With spectral CT, a defined energy range can be selected for tomographic reconstruction, which allows the contrast between tissues to be optimised while reducing or eliminating beam-hardening artefacts.…”