Method for detecting an explosive in an object under investigation
First Claim
1. A method for detecting an explosive in an object under investigation, comprising the following steps:
- (a) initially exposing the object under investigation to X-rays;
(b) recording the X-rays that have passed through the object under investigation;
(c) finding areas of the object under investigation with a density of organic materials exceeding a pre-established value, on a basis of a value of X-ray attenuation;
(d) identifying articles contained in the aforementioned found areas of the object under investigation with said density of organic materials higher than the pre-established value, on a basis of an analysis of said recorded X-rays;
(e) selecting among said areas of the object under investigation an area containing an unidentified article;
(f) in case all the articles are identified as not containing explosive the process of detecting is stopped;
(g) in case any article are unidentified the method of detecting further comprising;
(h) determining the dimensions and position of said unidentified article in the object under investigation, on a basis of an analysis of said recorded X-rays;
(i) evaluating a mass of an explosive being detected which corresponds to said dimensions of the unidentified article;
(j) determining and forming a directional pattern of a thermal neutron radiator which corresponds to said dimensions of the unidentified article;
(k) exposing to thermal neutrons the selected area of the object under investigation containing the unidentified article;
(l) recording, using at least two gamma-ray detectors, gamma-ray quanta with the energy of 10.8 MeV and pairs of simultaneously emitted cascade gamma-ray quanta emitted by said area of the object under investigation exposed to thermal neutrons;
(m) counting pairs of said cascade gamma-ray quanta recorded simultaneously;
(n) determining the overall intensity of gamma rays emitted by the object under investigation;
(o) determining a threshold value for said overall intensity of gamma rays emitted by the object under investigation, on a basis of said evaluated mass of the explosive being detected which corresponds to the dimensions of the unidentified article;
(p) making a decision about presence of the explosive in the object under investigation in the event that said overall intensity of gamma rays emitted by the object under investigation exceeds the said threshold value.
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Accused Products
Abstract
A method for detecting an explosive in an object under investigation involves the initial X-ray irradiation of the object under investigation, e.g. a piece of luggage or mailing, and forming its X-ray images; using the X-ray images to detect areas with a high density of organic materials and identifying articles therein; determining the location, dimensions and supposed mass of an unidentified article; determining and forming a directional pattern of the neutron radiator corresponding to the dimensions of the unidentified article. The method further includes subsequent thermal neutron irradiation of the area with the unidentified article; recording gamma-ray quanta having the energy of 10.8 MeV and cascade gamma-ray quanta with energies of 5.534 and 5.266 MeV by at least two gamma-ray detectors; counting of simultaneously recorded pairs of cascade gamma-ray quanta; determination of the overall gamma-ray intensity, taking into account weight factors in readings of the detectors; determination of the threshold value for the overall gamma-ray intensity basing on the supposed mass of explosive being detected; and making a decision in the event the threshold value of overall gamma-ray intensity is exceeded. When checking small-size objects, the neutron irradiation step is preceded by replacing the ambient air by a gaseous medium not containing nitrogen.
55 Citations
10 Claims
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1. A method for detecting an explosive in an object under investigation, comprising the following steps:
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(a) initially exposing the object under investigation to X-rays;
(b) recording the X-rays that have passed through the object under investigation;
(c) finding areas of the object under investigation with a density of organic materials exceeding a pre-established value, on a basis of a value of X-ray attenuation;
(d) identifying articles contained in the aforementioned found areas of the object under investigation with said density of organic materials higher than the pre-established value, on a basis of an analysis of said recorded X-rays;
(e) selecting among said areas of the object under investigation an area containing an unidentified article;
(f) in case all the articles are identified as not containing explosive the process of detecting is stopped;
(g) in case any article are unidentified the method of detecting further comprising;
(h) determining the dimensions and position of said unidentified article in the object under investigation, on a basis of an analysis of said recorded X-rays;
(i) evaluating a mass of an explosive being detected which corresponds to said dimensions of the unidentified article;
(j) determining and forming a directional pattern of a thermal neutron radiator which corresponds to said dimensions of the unidentified article;
(k) exposing to thermal neutrons the selected area of the object under investigation containing the unidentified article;
(l) recording, using at least two gamma-ray detectors, gamma-ray quanta with the energy of 10.8 MeV and pairs of simultaneously emitted cascade gamma-ray quanta emitted by said area of the object under investigation exposed to thermal neutrons;
(m) counting pairs of said cascade gamma-ray quanta recorded simultaneously;
(n) determining the overall intensity of gamma rays emitted by the object under investigation;
(o) determining a threshold value for said overall intensity of gamma rays emitted by the object under investigation, on a basis of said evaluated mass of the explosive being detected which corresponds to the dimensions of the unidentified article;
(p) making a decision about presence of the explosive in the object under investigation in the event that said overall intensity of gamma rays emitted by the object under investigation exceeds the said threshold value. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
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Specification