Radiation scanning of objects for contraband

A method of examining contents of an object, comprising:

• moving at least one radiation source along a continuous two-dimensional path extending only partially around an object;
• scanning at least a portion of the object with at least one radiation beam from the at least one radiation source at a plurality of angles;
• detecting radiation interacting with the object by a detector positioned at least partially below ground;
• and
• reconstructing images based, at least in part, on the detected radiation from the at least one radiation source along the continuous two-dimensional path.

A scanning unit for examining contents of a cargo container movable along a first path, the scanning unit comprising:

• a plurality of sources of radiation, at least some of the plurality of sources being configured to irradiate the cargo container with a cone beam of radiation and being movable along a continuous second path transverse to the first path, the second path being semi-circular and extending at least partially around the first path;
• and
• a semi-circular detector extending at least partially around the first path, the detector being positioned to detect radiation interacting with the cargo container during scanning;
• wherein:
• the second, semi-circular path lies along a first imaginary circle;
• the semi-circular detector lies along a second imaginary circle larger than the first imaginary circle;
• the first imaginary circle lies, at least in part, within the second imaginary circle;
• and
• the at least some of the plurality of sources and the detector are positioned so that the cargo container is transportable along the first path, between the at least some of the plurality of sources and the detector.

A scanning unit for examining contents of a cargo container movable along a first path, the scanning unit comprising:

• one or more sources of radiation configured to generate at least one cone beam of radiation, at least one of the one or more sources being movable along a two-dimensional second path substantially transverse to the first path, the second path extending at least partially around the first path;
• and
• a first, spatial detector extending at least partially around the first path, the detector being positioned to detect radiation from the at least one of the one or more sources of radiation along the two-dimensional second path, interacting with the cargo container during scanning;
• a second, energy sensitive detector extending at least partially around the first path, the detector being positioned to detect radiation from the at least one of the one or more sources of radiation along the two-dimensional second path, interacting with the cargo container during scanning;
• and
• a processor to fuse images derived from the first, spatial detector with images derived from the second, energy sensitive detector;
• wherein the at least one source and the first and second detectors are positioned so that the cargo container is transportable along the first path, between the one or more sources and the first and second detectors.

A scanning unit for examining contents of an object movable along a first path, the scanning unit comprising:

• one or more sources of radiation, at least one of the one or more sources being movable along a continuous two-dimensional second path substantially transverse to the first path, the second path being semi-circular and extending only partially around the first path;
• and
• a stationary detector extending only partially around the first path, the detector being positioned to detect radiation, from the one or more sources along the continuous two-dimensional second path, interacting with the object during scanning;
• wherein:
• the second, semi-circular path lies along a first imaginary circle;
• the semi-circular detector lies along a second imaginary circle larger than the first imaginary circle;
• the first imaginary circle lies, at least in part, within the second imaginary circle;
• the at least one source and the detector are positioned so that the cargo container is transportable along the first path, between the one or more sources and the detector;
• and
• both the second semi-circular path and the semi-circular detector extend over respective arcs, each arc being greater than 180 degrees, to collect sufficient data for computed tomographic reconstruction.

A scanning unit for examining contents of an object movable along a first path, the scanning unit comprising:

• a rail transverse to the first path;
• a plurality of sources of radiation coupled to the rail, at least some of the plurality of sources being movable along a second path transverse to the first path along the rail;
• a detector array positioned to detect radiation interacting with the object during scanning, the detected radiation originating from at least certain of the plurality of sources along the rail;
• wherein:
• the plurality of sources and the detector array are positioned so that the object is transportable along the first path, between the plurality of sources and the detector array;
• and
• one or more of the at least certain sources are configured to emit radiation beams that partially overlap at least one respective radiation beam emitted by an adjacent radiation source on a portion of the detector array;
• the scanning unit further comprising a processor configured to turn on at the same time only those radiation sources of the one or more of the at least certain sources that emit radiation beams that do not overlap on portions of the detector array, during scanning.