There are many examples when taking a transmission X-ray image where correct interpretation of that image would benefit from being able to correctly identify and characterise the materials that are present. If the object is anything other than a thin sheet the ability to isolate and characterise materials in 3D space becomes important. An example where this ability could transform the use of X-ray imaging is security. We will target four areas of application: 1. Explosives and weapons - Weapons and explosives illegally imported into the UK are used in violent crime and terrorist activities. Detection and identification of these items at UK points of entry is a priority for the UK Government and is key to reducing crime and disrupting the UK based terrorist threat. 2. Illicit drugs - The use of illicit drugs costs the UK £15.4 billion per year, and has massive implications for public health due to physical harm to users, drug dependencies, and the effect on families, community and society. The UK Government implemented a new strategy in 2010 with a main aim of restricting the supply of drugs, and the Home Office CAST is very active in developing new technology for the detection of drugs and other contraband substances. 3. New psychoactive substances (NPS) - Similarly NPS or 'legal highs' can carry serious health risks. Typically the chemicals they contain are not endorsed for human consumption and the resulting effects are unknown and unpredictable. In a recent review, the UK Government outlined an action plan for dealing with the growing NPS problem. Central to the action plan was for the UK Border Agency to be able to identify shipments of NPS entering the UK so they can be seized and destroyed. 4. Counterfeit drugs - The sale of substandard and counterfeit pharmaceutical products accounts for 10% of global trade and is affecting many countries (mainly developing countries but also developed countries to a lesser extent), causing serious downstream expense, resource shortages and detriment to health. One of the main aims of the UK Medicines and Healthcare Regulatory Agency (MHRA) is preventing counterfeit drugs entering the supply chain with more responsibility being put on the wholesaler to ensure drugs are sourced from legitimate suppliers and to report any suspicious activity. The proposal is to deliver an X-ray imaging and analysis system that is capable of non-invasively identifying explosives, illicit drugs, legal highs and counterfeit pharmaceuticals within baggage, packets, boxes and other containers. The system will provide high resolution transmission images as well as the analysis and position of selected materials within a larger 3D volume (e.g. a packet of illegal drugs within a parcel containing other items). Central to this project is a novel X-ray diffraction technique developed at UCL with Home Office and Department of Homeland Security backing, which has been proven to be highly effective for this purpose. This will now be enhanced such that rapid, full 3D capability will allow larger, more complex containers, as are found in real-world applications, to be analysed.