Method and apparatus for detecting concealed substances
First Claim
1. A method for detecting the presence of a number of substances in a container, which comprises irradiating the container with fast neutron and gamma source radiation, measuring the extent to which each species of the source radiation is transmitted through the container, and analyzing the measurements with reference to known characteristic attenuation coefficients and density properties of the substances for each species of the source radiation to determine from the attenuation of both the transmitted neutron and gamma source radiations the presence of said substances.
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Accused Products
Abstract
A method and apparatus detects the presence of a number of substances such as explosives or drugs in a container such as luggage (10) at an airport. The containers, travelling on a conveyor (15) for example are irradiated with fast neutron and gamma source radiation (6) preferably simultaneously and preferably of different frequencies. The radiation is detected (7) and the extent to which each species of the source of radiation is transmitted through the container is measured. The measurements are analyzed with reference to the known characteristic attenuation coefficients and density properties of those substances for each species of the source radiation.
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Citations
23 Claims
- 1. A method for detecting the presence of a number of substances in a container, which comprises irradiating the container with fast neutron and gamma source radiation, measuring the extent to which each species of the source radiation is transmitted through the container, and analyzing the measurements with reference to known characteristic attenuation coefficients and density properties of the substances for each species of the source radiation to determine from the attenuation of both the transmitted neutron and gamma source radiations the presence of said substances.
- 12. Apparatus for detecting the presence of a number of substances in a container, which comprises means which irradiates the container with fast neutron and gamma source radiation, means which measures the extent to which each species of said radiation is transmitted through the container, and means which analyses the measurements with reference to known characteristic attenuation coefficients and density properties of the substances for each species of the source radiation and determines from the attenuation of both the transmitted neutron and gamma source radiations the presence of said substances.
Specification