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

Abstract

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 [I]. 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.

Herramienta Numérica Para La Evaluación De Desplazamientos De Dos Fases en Medios Porosos Usando Tomografía Computarizada

“…Esta técnica requiere del escaneo del objeto en diferentes puntos, generando imágenes bidimensionales, con las que se pueden realizar reconstrucciones volumétricas (Buzug, 2008). Sus aplicaciones incluyen la detección de sustancias peligrosas y explosivos (Cozzini et al, 2012;Strecker, 1998), control de calidad en la industria de manufactura (Smith, 1999), detección de drogas ilegales (Pani et al, 2009), imágenes diagnosticas médicas y antropología (Blau et al, 2008;Borkan et al, 1983;Fajardo y Müller, 2001), ciencias forenses (Kellinghaus et al, 2010;Thali et al, 2003a;Thali et al, 2003b), arqueología (Uda et al, 2005), paleontología (Tafforeau et al, 2006), entre otras. La adquisición de imágenes por tomografía tiene una ventaja sobre la resonancia magnética, dado que esta última requiere que el objeto escaneado contenga iones de hidrogeno en forma de agua.…”

Compressed sampling strategies for tomography

“…Alternatively, measuring scatter may provide valuable information about the molecular structure of the imaged object [28] and can be used for material discrimination and characterization. For example, this is used in security applications, where dangerous substances such as explosives can be detected [29,30]. Other applications include quality control in industrial manufacturing [31] and illegal drug detection [32].…”