Abstract: The present invention pertains to a method and an apparatus to generate a density image of an object using fan or cone beams of radiation and collimated detectors on one side of the object. The method consists of irradiating an object with a plurality of pairs of non-parallel radiation beams wherein the beams in each pair intersect a same segment along the axis of the detector. Compton-scattering radiation from the beams are then measured, and corrected attenuation coefficients along each beam are obtained. This latter step is effected by taking a first ratio of detector measurements for the beams in each pair; comparing the first ratio with a second ratio of corresponding calculated detector measurements and balancing discrepancies between the first and second ratios in a forward-inverse numerical analysis algorithm. Taking ratios of attenuation coefficients along related incident beams eliminates non-linearity problems whereby the aforesaid algorithm can be solved.

Abstract: The present invention pertains to a method and an apparatus to generate a density image of an object using fan or cone beams of radiation and collimated detectors on one side of the object. The method consists of irradiating an object with a plurality of pairs of non-parallel radiation beams wherein the beams in each pair intersect a same segment along the axis of the detector. Compton-scattering radiation from the beams are then measured, and corrected attenuation coefficients along each beam are obtained. This latter step is effected by taking a first ratio of detector measurements for the beams in each pair; comparing the first ratio with a second ratio of corresponding calculated detector measurements and balancing discrepancies between the first and second ratios in a forward-inverse numerical analysis algorithm. Taking ratios of attenuation coefficients along related incident beams eliminates non-linearity problems whereby the aforesaid algorithm can be solved.

Abstract: The present invention pertains to a non-rotating method for non-intrusively determining the density of a point embedded within an object, without necessarily obtaining a full image for the entire object. The method consists of passing a X-ray beam through a point within an object and measuring Compton scatterings from the point from a first and second energy bands within the energy spectrum of the X-ray beam, along a first and second angles from the X-ray beam. Using the kinetics of Compton scattering at a specific angle, four equations are formulated with four measurements and four unknowns; the radiation attenuation factor along the object between the X-ray source and the point, the radiation attenuation factor between the point and each of the detectors and the density of the object at the point. The four equations are solved simultaneously to determined the four unknowns. There is also provided a matrix inversion process to facilitate the solution of the equations.

Abstract: The system for inspecting an object comprises a structure having a first, second and third orthogonal axes, and a source of x-ray pencil beam mounted thereto along the first axis. An incident radiation detector is mounted to the structure perpendicularly to the first axis. A first and second linear arrays of scattered radiation detectors are mounted to the structure perpendicularly to the second and third axes respectively. The source of x-ray pencil beam, the incident radiation detector and the first and second linear arrays of scattered radiation detectors are spaced apart and define therebetween an inspection zone. In use, an object to be inspected is moved inside the inspection zone relative to the x-ray pencil beam. The object is inspected voxel by voxel and the radiation measurements taken at each voxel are indicative of incident radiation attenuation, scattered radiation attenuation and electron density of that voxel.

Abstract: The present invention pertains to a non-rotating method for non-intrusively determining the density of a point embedded within an object, without necessarily obtaining a full image for the entire object. The method consists of passing a X-ray beam through a point within an object and measuring Compton scatterings from the point from a first and second energy bands within the energy spectrum of the X-ray beam, along a first and second angles from the X-ray beam. Using the kinetics of Compton scattering at a specific angle, four equations are formulated with four measurements and four unknowns; the radiation attenuation factor along the object between the X-ray source and the point, the radiation attenuation factor between the point and each of the detectors and the density of the object at the point. The four equations are solved simultaneously to determined the four unknowns. There is also provided a matrix inversion process to facilitate the solution of the equations.

Abstract: The system for inspecting an object comprises a structure having a first, second and third orthogonal axes, and a source of x-ray pencil beam mounted thereto along the first axis. An incident radiation detector is mounted to the structure perpendicularly to the first axis. A first and second linear arrays of scattered radiation detectors are mounted to the structure perpendicularly to the second and third axes respectively. The source of x-ray pencil beam, the incident radiation detector and the first and second linear arrays of scattered radiation detectors are spaced apart and define therebetween an inspection zone. In use, an object to be inspected is moved inside the inspection zone relative to the x-ray pencil beam. The object is inspected voxel by voxel and the radiation measurements taken at each voxel are indicative of incident radiation attenuation, scattered radiation attenuation and electron density of that voxel.