(Courtesy of Bruker Corporation)
X-ray interactions within a material (solids, powders, gels or liquids) is well understood and produce scattered X-rays (Figure 1), which give rise to material specific signatures. For example, coherent scattering or X-ray diffraction is the scientific principle exploited in standard laboratory instrumentation. Such instruments or diffractometers are relatively large, cumbersome and slow in operation but do reveal a wealth of detailed information concerning the atomic and molecular structure of a specimen; albeit over an area defined by a small stationary interrogating X-ray beam. This fundamental analytical approach has been essentially unchanged for over a century and may be considered the ‘Gold Standard’ for materials identification. The information provided by X-ray diffraction is of great scientific and technological importance but its translation into scanning or imaging applications has been extremely limited. This situation is largely dictated by the inherently weak nature of the diffraction phenomenon.
HALO X-ray diffraction technology was conceived, patented and funded specifically to realise high speed security screening for material specific scanning and imaging; primarily the identification of explosives and contraband drugs. To address this task required a completely new approach to overcome the factors, which limit current technologies. The conventional wisdom dictates that to obtain sufficiently large signals for analysis requires a narrow X-ray beam to ‘stare’ at a specimen, while the signal is being integrated. The primary limiting factor here is the inherently weak nature of the signals. This approach leads to slow operation, which is unsuitable as the basis for a scanning technology. The core innovation in our technology is to affect orders of magnitude increase in the material signatures together with employing a relatively large scanning beam ‘footprint’. HALO achieves this twofold advantage by employing hollow X-ray beam geometry (Figure 2). The intersection of the hollow beam with a material under inspection produces a ‘lensing’ effect to focus and intensify material signatures onto a sensor (Figure 3). This approach has the potential to drastically reduce data collection times and make instrumentation simpler, faster, lower cost and more compact.
This step change in capability leads directly to the potential to develop exciting new scanning products. Commercial interest in this technology is established by a market survey of industrial sectors where diffraction information is a critical aspect of inspection or process control. The technology is not only new to the security screening sector but also to the diffraction world as a whole. There are a very limited number of options for companies to develop new products for in-obscura materials identification. HALO technology can be integrated with existing systems or used alone to provide definitive materials identification, opening new markets for our partners to exploit X-ray diffraction. HALO is a platform technology and can equally be applied in a number of different market sectors.