Patent ID: 8110812
Filing Date: 2012-02-07
Classification: G01N

Abstract:
1. A method for detecting nitrogenous materials within an object by means of Gamma-Resonance Absorption (GRA), comprising: (i) placing a target on one side of an inspected object, said target containing (ii) placing on an opposite side of the object, on the periphery of a flux cone at polar angle θ (iii) screening the object with a gamma-ray beam from said source; (iv) reading from said gamma-ray detector total and non-resonant attenuations of incident photon flux; (v) deriving from said attenuations a net resonant attenuation and spatial distribution thereof; and (vi) determining a status of said inspected object based on a nitrogen-density distribution derived from said net resonant attenuation and said spatial distribution thereof; wherein screening the object comprises one or more of the following steps: I performing a rapid pre-scan to classify an overall gamma-ray-attenuation regime and locate regions of high physical density; II performing a full scan to identify and locate regions that contain nitrogenous materials; III dividing said flux cone into azimuthal angular segments and performing a plurality of scans in at least some of said segments to establish presence of explosives; and IV performing localized scans of specific regions to confirm presence of explosives.