Three Dimensional Material Specific Imaging Using Energetic Pulsed Neutrons

A novel method for detecting materials concealed in fully loaded cargo containers and trucks using pulsed neutrons has been developed. This method, called Pulsed Fast Neutron Analysis (PFNA), uses a collimated beam of nanosecond pulsed, mono-energetic neutrons to stimulate gamma rays emitted from the elements in the cargo materials through inelastic scattering. The collimation and precise timing of the gamma rays allows the position of the interactions to be determined. By sweeping the beam over the inspected object as it is conveyed, a full three-dimensional image of the elemental contents is composed. Unique elemental signatures of specific materials are then used to identify the contraband.This technique has been incorporated into a cargo and truck inspection system capable of scanning full-sized cargo containers. Algorithms have been developed to detect concealed drugs, explosives and hazardous materials. The location of the detected materials is displayed on a unique, workstation-based, user interface, Pull-down menus allow the user to select the elements of interest and the resulting display indicates the location and spatial extent of the material in three-dimensions.