Detection of explosives in airport baggage using coherent x-ray scatter

Bulk objects can be investigated for their material constituents by applying high-energy (30 keV to 100 keV) coherent X-ray scattering. When aiming at the detection of explosives in airport baggage, the technique allows discrimination between explosives and other substances. Coherent X-ray scatter measurements are presented for a set of explosives and their constituents as well as for a variety of nonexplosive materials. They demonstrate the superior material discrimination power of this method. The measurements have provided a quantitative basis for the prototype design of an airport baggage scanner. Sensitivity (200 g) and inspection time requirements (a few seconds) demand a highly application-specific system design with parallel acquisition and analysis of scatter spectra from different volume elements.