METHOD AND APPARATUS FOR DETECTING AND CLASSIFYING EXPLOSIVES AND CONTROLLED SUBSTANCES
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Accused Products
Abstract
A system for detecting and classifying small amounts of explosives and other controlled substances while rejecting confounders, including a source/detector array formed of a plurality of sources and a plurality of detectors, a signal processor coupled to the source/detector array for processing data received from the detectors, a classifier coupled to the signal processor for classifying data received from the signal processor according to a plurality of algorithms, a maximal rejection classifier coupled to the classifier; and a declarative decision module coupled to the maximal rejection classifier for rendering an accurate decision regarding the contents of the object is provided. The apparatus includes an enclosure, a shield layer disposed within the enclosure, a cavity disposed within the shield layer, a plurality of neutron sources and a detection array disposed within the cavity, and a transport mechanism for moving objects through the cavity past the sources and detection array. The cavity has one or more turns which preclude a straight line trajectory through the cavity. The shield layer is water-filled to prevent stray radiation from exiting the enclosure. The use of multiple lower power neutron sources and the particular geometry of the enclosure provide a compact, relatively lightweight explosive detection system which is practical for use in airports and other public locations.
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Citations
50 Claims
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1-22. -22. (canceled)
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23. A method of determining whether explosives or controlled substances are present in an object comprising confounders, comprising:
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transporting the object through a cavity in a shielded apparatus, said cavity comprising one or more turns which preclude a straight line trajectory through the cavity; generating neutron particles from a plurality of neutron sources by pulsing the neutron sources simultaneously, each source having an intensity of about 107 neutrons/second or less; irradiating the object with the neutron particles to cause the object to generate gamma rays; detecting the gamma rays with a plurality of gamma ray detectors; analyzing the gamma counts associated with the object; determining that an explosive or controlled substance is present in the object when the relative atomic percentages of elements comprising the object are substantially similar to the relative atomic percentages of elements associated with known explosives and controlled substances; determining that an explosive or controlled substance is not present in the object when the relative atomic percentages of elements comprising the object are not substantially similar to the relative atomic percentages of elements associated with known explosives and controlled substances; and pulsing the neutron sources sequentially if it is determined that an explosive or controlled substance is present in the object. - View Dependent Claims (25, 26, 29, 30, 31, 32, 34, 36, 37, 38, 40, 41, 42, 43, 44, 47, 48)
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24. A method of determining whether explosives or controlled substances are present in an object comprising confounders, the method comprising:
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irradiating the object with neutron particles from a plurality of neutron sources by pulsing the neutron sources simultaneously; detecting gamma rays emitted by substances contained within the object in response to the irradiation; determining gamma counts with a plurality of gamma ray detectors; isolating common eigen value signatures of the substances contained within the object; analyzing the common eigen value signatures using a plurality of analytical tools to produce a plurality of analyses; subjecting the plurality of analyses to a hierarchy of classifiers to determine if at least one of an explosive or controlled substances is present in the object; and pulsing the neutron sources sequentially if it is determined that an explosive or controlled substance is present in the object to more accurately identify the location of the explosive or controlled substance in the object.
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27-28. -28. (canceled)
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33. (canceled)
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35. (canceled)
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39. (canceled)
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45. (canceled)
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46. (canceled)
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49. A method of determining whether explosives or controlled substances are present in an object comprising confounders, the method comprising:
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irradiating the object with neutron particles a first time from a plurality of neutron sources by pulsing the neutron sources simultaneously wherein the object generates gamma rays; detecting the gamma rays emitted by substances contained within the object in response to the first irradiation; determining gamma counts with a plurality of gamma ray detectors; isolating common eigen value signatures of the substances contained within the object to generate signature data; forming a correlation function of the signature data; decomposing wavelets of the correlation function of the signature data; comparing the incoming decomposed signature data with a library of signatures to determine if at least one of an explosive or controlled substance is present in the object; and irradiating the object with neutron particles a second time by pulsing the neutron sources sequentially if it is determined that an explosive or controlled substance is present in the object to more accurately identify the location of the explosive or controlled substance in the object. - View Dependent Claims (50)
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Specification