Apparatus and method for imaging the structure of diamagnetic and paramagnetic objects

Claim 1

A system for imaging the structure of at least a selected portion of an object substantially composed of at least one of diamagnetic and paramagnetic materials, said system including: means applying a magnetic field of known strength, orientation and time dependence to the at least selected portion of said object: magnetometer means measuring local perturbations in the applied magnetic field indicating local susceptibility of said object at an array of locations across said at least selected portion of said object to generate an array of perturbation signals; adjusting means adjusting the angular orientation of at least one of said magnetic field, said object, and said magnetometer means relative to the others to generate a plurality of relative orientations, said magnetometer means including means measuring local perturbations in the applied magnetic field at an array of locations for each of said plurality of relative orientations to produce a plurality of arrays of perturbation signals; processing means processing by matrix decomposition techniques said plurality of arrays of perturbation signals to generate at least one array of signals representing a map of local susceptibilities at selected sites in said at least selected portion of said object; and means presenting said array of local susceptibilities at the selected sites in the at least selected portion of said object.

Claim 2

A system for imaging the structure of at least a selected portion of an object substantially composed of at least one of diamagnetic and paramagnetic materials, said system including: means applying a magnetic field of known strength, orientation and time dependence to the at least selected portion of said object: magnetometer means measuring local perturbations in the applied magnetic field indicating local susceptibility of said object at an array of locations across said at least selected portion of said object to generate an array of perturbation signals; adjusting means adjusting the angular orientation of at least one of said magnetic field, said object, and said magnetometer means relative to the others to generate a plurality of relative orientations, said magnetometer means including means measuring local perturbations in the applied magnetic field at an array of locations for each of said plurality of relative orientations to produce a plurality of arrays of perturbation signals; processing means processing by matrix decomposition techniques said plurality of arrays of perturbation signals to generate at least one array of signals representing a map of local susceptibilities at selected sites in said at least selected portion of said object; and means presenting said array of local susceptibilities at the selected sites in the at least selected portion of said object.

Claim 16

A system for imaging the structure of at least a selected portion of an object substantially composed of at least one of diamagnetic and paramagnetic materials, said system including: coil means applying a substantially uniform magnetic field to the at least selected portion of said object; gradient SQUID magnetometer means measuring local perturbations in the applied magnetic field indicating local susceptibility of said object at an array of locations across said at least selected portion of said object to generate an array of perturbation signals; adjusting means adjusting the angular orientation of at least one of said magnetic field, said object, and said magnetometer means relative to the others to generate a plurality of relative orientations, said gradient SQUID magnetometer means measuring local perturbations in the applied magnetic field at an array of locations for each of said plurality of relative orientations to produce a plurality of arrays of perturbation signals; processing means processing by matrix decomposition techniques said plurality of arrays of said perturbation signals to generate at least one array of signals representing a map of local susceptibilities at the selected sites in said at least selected portion of said object; and means generating an image from said array of local susceptibilities at the selected sites in the at least selected portion of said object.

Claim 17

A system for imaging the structure of at least a selected portion of an object substantially composed of at least one of diamagnetic and paramagnetic materials, said system including: coil means applying a substantially uniform magnetic field to the at least selected portion of said object; gradient SQUID magnetometer means measuring local perturbations in the applied magnetic field indicating local susceptibility of said object at an array of locations across said at least selected portion of said object to generate an array of perturbation signals; adjusting means adjusting the angular orientation of at least one of said magnetic field, said object, and said magnetometer means relative to the others to generate a plurality of relative orientations, said gradient SQUID magnetometer means measuring local perturbations in the applied magnetic field at an array of locations for each of said plurality of relative orientations to produce a plurality of arrays of perturbation signals; processing means processing by matrix decomposition techniques said plurality of arrays of said perturbation signals to generate at least one array of signals representing a map of local susceptibilities at the selected sites in said at least selected portion of said object; and means generating an image from said array of local susceptibilities at the selected sites in the at least selected portion of said object.

Claim 18

A method of imaging the structure of objects substantially composed of diamagnetic or paramagnetic materials and combinations thereof, said method comprising: applying a magnetic field of known strength and known time dependence to said object in a known orientation; scanning said object with magnetometer means to generate perturbation signals representing local perturbations to the magnetic field across at least a selected portion of said object resulting from local variations in susceptibility of the object; adjusting the angular orientation of at least one of said magnetic field, said object, and said magnetometer means relative to the others to generate a plurality of relative orientations, and repeating said scanning said object with said magnetometer means for each relative orientation to generate sets of perturbation signals each representing local perturbations to the magnetic field for one of said plurality of relative orientations; and processing using matrix decomposition techniques said sets of perturbation signals to indicate local susceptibility at at least selected sites in said at least selected portion of said object.

Claim 19

A method of imaging the structure of objects substantially composed of diamagnetic or paramagnetic materials and combinations thereof, said method comprising: applying a magnetic field of known strength and known time dependence to said object in a known orientation; scanning said object with magnetometer means to generate perturbation signals representing local perturbations to the magnetic field across at least a selected portion of said object resulting from local variations in susceptibility of the object; adjusting the angular orientation of at least one of said magnetic field, said object, and said magnetometer means relative to the others to generate a plurality of relative orientations, and repeating said scanning said object with said magnetometer means for each relative orientation to generate sets of perturbation signals each representing local perturbations to the magnetic field for one of said plurality of relative orientations; and processing using matrix decomposition techniques said sets of perturbation signals to indicate local susceptibility at at least selected sites in said at least selected portion of said object.

Claim 20

A method of imaging features of at least a selected portion of an object substantially composed of at least one of diamagnetic and paramagnetic materials, said method comprising steps of: applying a magnetic field of known strength and orientation to said at least selected portion of said object: measuring perturbations in the applied magnetic field indicating local susceptibility of said object at an array of locations across said at least selected portion of said object to generate an array of perturbation signals; adjusting the angular orientation of at least one of said magnetic field, said object, and a magnetometer means relative to the others to generate a plurality of relative orientations, said measuring further including measuring said perturbations in the applied magnetic field at an array of locations for each of said plurality of relative orientations to produce a plurality of arrays of perturbation signals; and processing using matrix decomposition techniques said plurality of arrays of perturbation signals to generate at least one array of signals representing a map of local magnetic susceptibilities at least selected sites in said at least selected portion of said object.

Claim 21

A method of imaging features of at least a selected portion of an object substantially composed of at least one of diamagnetic and paramagnetic materials, said method comprising steps of: applying a magnetic field of known strength and orientation to said at least selected portion of said object: measuring perturbations in the applied magnetic field indicating local susceptibility of said object at an array of locations across said at least selected portion of said object to generate an array of perturbation signals; adjusting the angular orientation of at least one of said magnetic field, said object, and a magnetometer means relative to the others to generate a plurality of relative orientations, said measuring further including measuring said perturbations in the applied magnetic field at an array of locations for each of said plurality of relative orientations to produce a plurality of arrays of perturbation signals; and processing using matrix decomposition techniques said plurality of arrays of perturbation signals to generate at least one array of signals representing a map of local magnetic susceptibilities at least selected sites in said at least selected portion of said object.

Claim 24

A method of non-destructive testing for flaws such as cracks and holes in a surface of an object substantially composed of at least one of diamagnetic and paramagnetic materials, said method comprising: applying a trace material having a susceptibility substantially different from the susceptibility of said object to the surface of said object to introduce said trace material into any flaws in said surface; applying a magnetic field to said object including said surface; scanning said surface with a magnetometer to measure perturbations in said applied magnetic field representing local susceptibility across said surface; and processing said measured perturbations in the magnetic field to identify the location of trace material in said any flaw in said surface.

Claim 25

A method of non-destructive testing for flaws such as cracks and holes in a surface of an object substantially composed of at least one of diamagnetic and paramagnetic materials, said method comprising: applying a trace material having a susceptibility substantially different from the susceptibility of said object to the surface of said object to introduce said trace material into any flaws in said surface; applying a magnetic field to said object including said surface; scanning said surface with a magnetometer to measure perturbations in said applied magnetic field representing local susceptibility across said surface; and processing said measured perturbations in the magnetic field to identify the location of trace material in said any flaw in said surface.

Claim 27

A method of non-destructive testing of an object substantially composed of at least one of diamagnetic and paramagnetic materials, said method comprising: dispersing throughout at least a selected portion of said object a trace material having a susceptibility substantially different from the susceptibility of the object; applying a magnetic field of known strength, orientation and time dependence to said object; scanning said object with magnetometer means to generate perturbation signals representing local perturbations to the magnetic field across at least the selected portion of said object resulting from local variations in susceptibility of the object and said trace material; and processing said perturbation signals to generate a representation of local susceptibility of the object and the trace material in at least selected locations in said at least selected portion of said object.

Claim 28

A method of non-destructive testing of an object substantially composed of at least one of diamagnetic and paramagnetic materials, said method comprising: dispersing throughout at least a selected portion of said object a trace material having a susceptibility substantially different from the susceptibility of the object; applying a magnetic field of known strength, orientation and time dependence to said object; scanning said object with magnetometer means to generate perturbation signals representing local perturbations to the magnetic field across at least the selected portion of said object resulting from local variations in susceptibility of the object and said trace material; and processing said perturbation signals to generate a representation of local susceptibility of the object and the trace material in at least selected locations in said at least selected portion of said object.

Claim 30

A method of non-destructive testing for flaws such as cracks and holes in a surface of an object substantially composed of at least one of diamagnetic and paramagnetic materials, said method comprising: applying a trace material having a susceptibility substantially different from the susceptibility of said object to the surface of said object to introduce said trace material into any flaws in said surface; applying a magnetic field to said object including said surface; scanning said surface with a magnetometer to measure perturbations in said applied magnetic field representing local susceptibility across said surface at an array of locations across said surface; and processing said measured perturbations in the magnetic field to generate a map of local susceptibilities imaging said any flaws.

Claim 31

A method of non-destructive testing for flaws such as cracks and holes in a surface of an object substantially composed of at least one of diamagnetic and paramagnetic materials, said method comprising: applying a trace material having a susceptibility substantially different from the susceptibility of said object to the surface of said object to introduce said trace material into any flaws in said surface; applying a magnetic field to said object including said surface; scanning said surface with a magnetometer to measure perturbations in said applied magnetic field representing local susceptibility across said surface at an array of locations across said surface; and processing said measured perturbations in the magnetic field to generate a map of local susceptibilities imaging said any flaws.

Claim 32

A method of non-destructive testing of an object substantially composed of at least one of diamagnetic and paramagnetic materials, said method comprising: dispersing throughout at least a selected portion of said object a trace material having a susceptibility substantially different from the susceptibility of the object; applying a magnetic field of known strength, orientation and time dependence to said object; scanning said object with magnetometer means to generate perturbation signals representing local perturbations to the magnetic field at an array of locations across at least said selected portion of said object resulting from local variations in susceptibility of the object and said trace materials; and processing said perturbation signals to generate a map of local susceptibility of the object and trace material in said at least selected portion of said object.

Claim 33

A method of non-destructive testing of an object substantially composed of at least one of diamagnetic and paramagnetic materials, said method comprising: dispersing throughout at least a selected portion of said object a trace material having a susceptibility substantially different from the susceptibility of the object; applying a magnetic field of known strength, orientation and time dependence to said object; scanning said object with magnetometer means to generate perturbation signals representing local perturbations to the magnetic field at an array of locations across at least said selected portion of said object resulting from local variations in susceptibility of the object and said trace materials; and processing said perturbation signals to generate a map of local susceptibility of the object and trace material in said at least selected portion of said object.