Modeling scattering for security applications: A multiple beam X-Ray Diffraction Imaging system

In the past decades several authors have demonstrated the ability of X-Ray Diffraction Imaging (XDI) in providing spatial and material specific information about the object under investigation [1]. Energy Dispersive X-Ray Diffraction (EDXRD) systems detect diffraction patterns by using a polychromatic spectrum and measuring the coherently scattered beam at a specific angle. This type of molecular-specific information plays a key role in security screening modalities providing high detection as well as low false alarm rates [2]. In the past, one of the main limitations to the widespread use of this technology in airport screening was the slow scanning rate compared to conventional systems. With the advent of novel system topologies such as the 3rd Generation energy-dispersive XDI configurations [3], this issue can be overcome [4]. In the present work a simulation tool accounting for molecular interference and providing multiple collimation configuration options has been validated with a single source dual-channel geometry. The primary-scatter and cross-scatter signals generated by two neighboring voxels have been studied here, analyzing both coherent and incoherent scatter contributions; and a method for a first order material independent cross-scatter correction has been evaluated. The tool has then been applied for first investigations of a Multiple Inverse Fan Beam (MIFB) concept.