Apparatus and method for detecting contraband using fast neutron activation
US5098640A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jan 10, 1990 |
| Grant date | Mar 24, 1992 |
| Priority date | — |
| Expiry date | Jan 10, 2010 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01V5/234
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
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…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.