Fast neutron resonance radiography for elemental mapping
AssigneeMassachusetts Institute of Technology
InventorsGongyin Chen, Richard C. Lanza
Life of this patent
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Abstract
Methods and apparatus involving neutron resonance radiography are used to map the elemental composition of an object. Sets of neutrons having energies within particular energy bands are directed through an object to be imaged. The attenuation of the neutrons passed through the object is detected, and that data can be used to detect explosives, weapons, drugs and other contraband.
Claims22
A method for mapping the elemental composition of an object, the method comprising the steps of:
- emitting a spectrum of neutrons from a source, wherein the energy of each emitted neutron is related to the angle at which the neutron is emitted from the source;
- positioning the object in the path of neutrons in a first radial sector of the neutron-emission spectrum;
- detecting neutrons that pass through the object when the object is positioned in the first radial sector and generating a reading of the detected neutrons;
- positioning the object in the path of neutrons in a second radial sector of the neutron-emission spectrum;
- detecting neutrons that pass through the object when the object is positioned in the second radial sector and generating a reading of the detected neutrons;
- and
- measuring the presence of at least one element in the object as a function of the readings of neutrons detected in the first and second radial sectors.
A method for mapping multiple elements in an object comprising the steps of:
- directing a first set of neutrons that have energies within a first range at an object, detecting the neutrons from the first set that pass through the object, and generating a reading of the detected neutrons from the first set;
- directing a second set of neutrons that have energies within a second range at the object, detecting the neutrons from the second set that pass through the object, and generating a reading of detected neutrons from the second set;
- directing a third set of neutrons having energies within a third range at the object, detecting neutrons from the third set that pass through the object, and generating a reading of detected neutrons from the third set;
- and
- generating a map of at least one element in the object from the readings of detected neutrons from each of the three sets.
An apparatus for mapping elements in an object comprising:
- a particle accelerator for delivering accelerated particles;
- a neutron-emitting target positioned to interact with accelerated particles delivered from the particle accelerator to produce a neutron-emission spectrum;
- a mount for supporting the object to be imaged;
- a drive mechanism coupled with at least one of the mount, the particle accelerator and the neutron-emitting target to allow the mount to be at different positions within the neutron-emission spectrum;
- and
- a detector configured to measure neutrons that pass from the target through an object supported by the displaceable mount.
A computer-readable storage medium storing software code that, when executed by a computer, compares neutron detection readings generated by a detector at multiple neutron energies with known neutron-attenuation levels for a plurality of elements at those neutron energies.
Dependencies are inferred from the claim text.