Science Applications International Corporation

Tsahi Gozani

Z. Peter Sawa

Patrick M. Shea

Ancore Corporation

Patrick M Shea

Z Peter Sawa

A nuclear detection system and method uses an artificial neural system to efficiently detect explosives in checked airline baggage or other parcels with a high probability of detection (PD) and a low probability of false alarms (PFA). The detection system detects the presence of nitrogen and other elements and their rough density distribution within the object under investigation by performing a nuclear-based analysis of the object. The detection system includes a source of neutrons; an array of gamma ray detectors; at least one neutron detector; means for irradiating the object being examined with neutrons from the neutron source, which neutrons interact with the atomic nuclei of one or more specific elements, e.g., nitrogen, chlorine, or hydrogen present within the object so as to cause elemental-specific gamma rays to be emitted; means for capturing and counting the elemental-specific gamma rays and determining their approximate origin within the object, thereby providing a rough measure of the density distribution of these specific elements within the object; and means for detecting neutrons that pass through the object without substantially interacting with atomic nuclei, thereby providing an image of the density distribution of elements in the object. The invention further includes an X-radiography system for generating a high-resolution two-dimensional density image of the object. An artificial neural system (ANS) provides an efficient means for analyzing the recorded gamma rays, image, and other data so as to accurately discriminate between objects carrying explosives and objects not carrying explosives.

Multi-sensor explosive detection system using an articifical neural

A system for detecting the presence of explosives contained in an object under observation, including a cavity structure for receiving the object and a radiation source for producing thermal neutrons directed to the object under observation. Gamma rays are produced to represent the presence of explosives and as an example the concentration of nitrogen contained in the object. Inorganic scintillators are located within the cavity structure to detect the gamma rays and produce an output signal representative of the presence and concentration of the nitrogen and/or other elements contained in the object. The inorganic scintillators are formed as a ring around the cavity structure to detect the nitrogen and/or other elements within at least one particular plane passing through the object. The object under observation is moved through the cavity structure to detect the nitrogen in successive planes to build up a three dimensional profile of explosives concentration.

Explosive detection system

An apparatus and method non-invasively interrogates an object to detect contraband. The apparatus irradiates the object with fast neutrons of energy greater than 6.7 MeV, and measures the ensuing gamma-ray spectra. Irradiation of the object is accomplished by producing a neutron beam and moving the interrogated object stepwise or continuously relative to the beam. The nuclear interactions of highly penetrating neutrons within the irradiated volume of the object give rise to energetic nuclear-species characteristic gamma-rays. The energy and intensity of the emitted gamma-rays provide information relative to the spatial and density distributions of the gamma-ray sources, i.e., the specific atomic nuclei within the object. From this information, three-dimensional images of the atomic nuclei spatial and density distributions are inferred. Such three-dimensional images allow a decision to be made as to the presence of contraband. Measurements are made using arrays of gamma-ray scintillator detectors. A decision analysis based on statistical methods (e.g., discriminant analysis) or an artificial neural system, or other expert system, facilitates a low false alarm rate. One embodiment of the apparatus includes neutron beam collimator means to define and limit the irradiation volume of the object, and auxiliary neutron shielding means to attenuate the neutrons in other than desired neutron beam direction(s). Another embodiment includes an X-ray system and combines electron density information obtained from an X-ray image of the object with the spatial and density distribution information of the gamma-ray sources in order to further enhance the decision analysis.

Apparatus and method for detecting contraband using fast neutron

A nuclear detection system and method efficiently detects explosives in checked airline baggage or other parcels with a high probability of detection (PD) and a low probability of false alarms (PFA). The detection system detects the presence of nitrogen and its rough density distribution within the object under investigation by performing a nuclear-based analysis of the object. The detection system includes a source of thermal neutrons; an array of gamma ray detectors; a neutron detector; means for irradiating the object being examined to neutrons from the neutron source, which neutrons interact with the atomic nuclei of one or more specific elements, e.g., nitrogen, chlorine, or hydrogen present within the object so as to cause elemental-specific gamma rays to be emitted; means for capturing and counting the elemental-specific gamma rays and determining their approximate origin within the object, thereby providing a rough measure of the density distribution of these specific elements within the object; and means for detecting neutrons that pass through the object without substantially interacting with atomic nuclei, thereby providing an image of the atomic density distribution of the object similar to conventional neutron radiography. One embodiment of the invention includes an artificial neural system (ANS) of analyzing the recorded gamma rays and efficiently discriminating between objects carrying explosives and objects not carrying explosives. Another embodiment utilizes a spectral correlation method (SCM) to remove undesirable background noise from the spectrum of detected gamma rays. Still another embodiment uses a X-ray system to generate an electron density image of the object being investigated, which electron density image helps confirm the presence of explosives within the object.

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Sunnyvale, CA, United States of America

Patrick M Shea