Improved Identification of illicit materials using an X-ray backscattering technique

The aim of this project is to demonstrate the potential improvements that can be made in X-ray backscattering techniques to better identify illicitly smuggled material in cargo / baggage. The possibilities of this project will be achieved by combining a detailed understanding of the X-ray scattering processes and Monte-Carlo modelling with experimental results from poly-energetic X-ray sources and new high-efficiency, high-resolution CZT detectors.
Current state-of-the-art commercial X-ray backscatter cargo scanning systems make use of the increased scatter that results from low-Z (atomic number) organic materials to identify contraband items. The detectors used in current systems are only capable of measuring the intensity of scattered X-rays. However, areas of high-backscatter intensity, typically associated with contraband (drugs, tobacco, plastic explosives & currency), can be established as brighter regions in an X-ray image. This rather basic level of organic/inorganic separation is usually the only information available. To date, this has been considered sufficient to identify crates which don't meet their manifest and require human inspection. This process creates delays and some crates are unnecessarily opened.