Abstract: Apparatus and methods for effectively detecting and locating explosive substances within remote targets, including improvised explosive devices (IEDs). The detection apparatus includes a neutron beam generator, a gamma ray detector, data collection modules and sensors, and a detection processing module. The neutron beam generator includes a fast neutron source, a neutron moderator to slow some or all of the fast neutrons to thermal energies, a partially enclosing neutron shield, and a rotatable neutron shield surrounding the generated neutrons. The neutron shield has an aperture to form a neutron beam directed at a remote target. If the remote target contains explosive substances, gamma rays radiate isotropically from the remote target when it is bombarded by the neutrons. A portion of these gamma rays are intercepted and detected by the gamma ray detector, which is spaced apart from the neutron source.

Abstract: Apparatus and method for detecting and locating hidden explosive substances. The detection apparatus includes a thermal neutron beam generator, a gamma ray detector, data collection module and sensors, and a detection processing module. The thermal neutron beam generator includes a fast neutron source, a neutron moderator to slow the fast neutrons to thermal neutrons, and a rotatable neutron shield enclosing the generated thermal neutrons. The rotatable neutron shield has an aperture through which a thermal neutron beam is projected at a remote target. Gamma rays radiating from hidden explosives in the remote target are detected by the gamma ray detector, while the associated detection processing module spatially locates the target based at least in part on the position of the aperture in the rotatable neutron shield.