Combined X-ray diffraction and kinetic depth effect imaging.

In this preliminary study we present a depth resolved transmission image sequence of an object combined with the materials discriminating ability of angular dispersive X-ray diffraction. Volumes within the object giving rise to diffraction patterns matched to a library of specific materials have been encoded visually within the images. The intensity of these highlighted areas has been weighted based on the certainty of the match. Both the theory and experimental proof of principle have been demonstrated. Considerations pertaining to a "scaled up" version of this technique are also discussed.

Position determination of scatter signatures--a novel sensor geometry.

A novel diffraction sensor geometry able to provide the diffraction pattern of a suspect material without prior knowledge of the samples location is introduced. The sensor geometry can also resolve diffraction patterns originating from multiple unknown materials overlapped along the primary X-ray beam path. This is achieved through tracking Bragg peak maxima that linearly propagate from the inspection volume at a series of X-ray detector positions. A series of simulations and experiments have been performed to verify this technique and provide an insight into its characteristics. Such a technique could have widespread appeal in the security industry. Areas of most relevance include the materials characterisation of volumes such as those prevalent in an airport screening environment or equally the rapid screening for illicit drugs trafficked through the postal system.

The separation of X-ray diffraction patterns for threat detection.

We introduce a novel method for identifying materials using a series of X-ray diffractograms collected in transmission. A multiple perspective approach is used to identify the diffractograms produced by materials located at different positions along the primary X-ray beam. This technique promises to enhance materials identification performance in cluttered environments such as those prevalent in aviation security screening.

Wire transfer function analysis for castellated dual-energy x-ray detectors.

An investigation into the spatial resolving power of a castellated linear dual-energy x-ray detector array is reported. The detector was developed for use in aviation security screening applications. Experiments employing different gauges of lead wire are used to plot a wire transfer function. A numerical simulation is developed to predict and underpin the empirical results. The suitable processing of the castellated detector signals helps to maintain spatial resolving power while affording a 50% reduction in x-ray sensing elements. This encouraging result has formed the basis for an ongoing investigation into materials discrimination capability of the castellated detector array.