Device and method for inspection of baggage and other objects

A device for detecting specific material of interest in an ensemble of objects, comprising:

• a conveyor for sequentially moving an ensemble of objects through an inspection region,
• a stationary X-ray source, located near said inspection region and positioned to expose sequentially said ensemble of objects,
• stationary X-ray detectors positioned to detect X-ray radiation transmitted through an item of said ensemble of objects, said detectors providing data corresponding to the intensity of transmitted radiation, and said detectors also providing detector outputs representing "no X-ray flux" data taken repeatedly when no X-ray radiation is arriving at said detectors after said X-ray exposure of said item, said "no X-ray flux" data also including a decay signal induced by said X-ray flux, and
• a computer operatively connected to said detectors to receive from each said detector both said X-ray data and said "no X-ray flux" data, said computer programmed to correct, for each detector, said X-ray data by eliminating contribution of said "no X-ray flux" data to said X-ray data and to determine, from said corrected X-ray data, the presence of said specific material of interest while said ensemble of objects progresses on said conveyor.

A device for detecting specific material of interest in an initially unidentified ensemble of objects, comprising:

• a conveyor for sequentially moving an ensemble of objects through an inspection region,
• a stationary X-ray exposure system located at said inspection region and positioned to expose sequentially said initially unidentified ensemble of objects in said inspection region to X-ray radiation of at least two substantially different energies,
• a stationary X-ray detection system positioned to detect X-ray radiation transmitted through said ensemble of objects, said detection system providing data corresponding to the intensity of transmitted radiation of said two energies,
• a computer operatively connected to said detection system to receive said data and programmed to calculate a value of a specific property of said specific material of interest in said ensemble of objects, and automatically discriminate said specific material of interest from other objects that are present based on said calculated value of said specific property, said automatic discrimination utilizing x-ray transmission data of rays passing through said unidentified ensemble of objects, and near but not through said specific material of interest to remove by computer calculation the contribution of unwanted overlying and underlying material of said ensemble of objects from the calculated value of said specific property of said specific material of interest, and
• said computer programmed to automatically indicate, based on said discrimination, presence of said specific material of interest while said ensemble of objects progresses on said conveyor.

A system for detecting a specific material of interest within a package or suitcase comprising:

• a conveyor for sequentially moving a package or suitcase
• an X-ray inspection unit constructed to acquire X-ray transmission data of said package or suitcase and indicate from said transmission data a suspect package or suitcase that warrants further detailed inspection by CT scanning,
• said conveyor further moving said suspect package or suitcase to a CT scanner, and
• said CT scanner constructed to CT scan said suspect package or suitcase to detect presence of said specific material of interest.

A method of detecting specific material of interest in an initially unidentified ensemble of objects, comprising:

• providing a stationary X-ray exposure system, a stationary X-ray detection system, and a computer operatively connected to said detection system,
• moving sequentially on a conveyor an initially unidentified ensemble of objects through an inspection region,
• exposing, at said inspection region, said ensemble of objects to X-ray radiation of at least two substantially different energies,
• detecting X-ray radiation transmitted through said ensemble of objects, and providing to said computer X-ray data corresponding to the intensity of transmitted radiation of said two energies,
• calculating a value of a specific property of a specific material of interest in said ensemble of objects, and automatically discriminating said specific material of interest from other objects that are present based on the calculated value of said specific property,
• in said automatic discrimination utilizing x-ray transmission data of rays passing through said initially unidentified ensemble of objects, and near but not through said specific material of interest to remove by computer calculation the contribution of unwanted overlying and underlying material of said ensemble of objects from the calculated value of said specific property of said specific material of interest, and
• automatically indicating, based on said discrimination, presence of said specific material of interest while said ensemble of objects progresses on said conveyor.

A method of detecting specific material of interest in an ensemble of objects, comprising:

• providing a stationary X-ray source, stationary X-ray detectors, and a computer operatively connected to said detector,
• moving sequentially on a conveyor an ensemble of objects through an inspection region,
• exposing, at said inspection region, said ensemble of objects to a flux X-ray radiation of at least two substantially different energies,
• detecting X-ray radiation transmitted through said ensemble of objects, and providing to said computer X-ray data corresponding to the intensity of transmitted radiation of said two energies,
• providing repeatedly to said computer detector outputs representing "no X-ray flux" data taken when no X-ray radiation is arriving at said detectors after the X-ray exposure of said ensemble of objects, said "no X-ray flux" data also including a decay signal induced by said X-ray flux,
• correcting, for each detector, said X-ray data by eliminating contribution of said "no X-ray flux" data to said X-ray data, and
• determining, from said corrected X-ray data, the presence of said specific material of interest while said ensemble of objects progresses on said conveyor.

A method for detecting a specific material of interest within packages or luggage comprising the steps of:

• moving sequentially on a conveyor packages or luggage,
• acquiring X-ray transmission data of an item of luggage or package, using an X-ray inspection unit with a stationary X-ray source-detector unit, and indicating from said X-ray transmission data a suspect item of luggage or package that warrants further detailed inspection by CT scanning,
• moving on said conveyor said suspect item to a CT scanner, and
• CT scanning said suspect item of luggage or package to detect said specific material of interest.