Neutron-gamma ray tomography

1. A neutron-gamma ray tomography system comprising:

a source for illuminating an object with a dual neutron-gamma ray beam, the source comprising a gamma target having a variable thickness, wherein the dual neutron-gamma ray beam has a variable neutron-gamma ratio as a function of the variable thickness;

a detector array for characterizing neutron and gamma ray attenuation in the object; and

an image processor for generating tomography as a function of the neutron and gamma ray attenuation.

2. The system of claim 1 , wherein the source generates neutrons via a fusion process comprising at least one of deuterium-deuterium, deuterium-tritium, or tritium-tritium fusion reactions, and further generates gamma rays via inelastic scattering of the neutrons from the gamma target.

3. The system of claim 1 , wherein the source simultaneously illuminates the object with a plurality of dual neutron-gamma ray beams.

4. The system of claim 3 , wherein the gamma target comprises a neutron moderator or a neutron multiplier.

5. The system of claim 1 , wherein the detector array comprises a cryogenic solid state detector element.

6. The system of claim 1 , wherein the detector array comprises a room-temperature solid state detector element.

7. The system of claim 1 , wherein the detector array comprises a scintillation detector element.

8. A neutron-gamma ray tomography system comprising:

a source for illuminating an object with a dual neutron-gamma ray beam;

a detector array for characterizing neutron and gamma ray attenuation in the object; and

an image processor for generating tomography as a function of the neutron and gamma ray attenuation;

wherein the function of the neutron and gamma ray attenuation comprises a neutron-gamma attenuation ratio.

9. The system of claim 8 , wherein the image processor further analyzes material composition as a function of the neutron-gamma attenuation ratio.

10. The system of claim 8 , wherein the image processor further analyzes material composition as a function of at least one of gamma ray spectroscopy or neutron-activated spectroscopy.

11. A container interrogation system comprising:

a source for interrogating the container with a dual neutron-gamma ray beam;

a detector array for detecting neutron and gamma ray transmission through the container; and

an image processor for generating three-dimensional tomography as a function of the neutron and gamma ray transmission, wherein the function of the neutron and gamma ray attenuation comprises a neutron-gamma attenuation ratio.

12. The system of claim 11 , wherein the container has a total length of at least three meters and a capacity of at least ten thousand kilograms.

13. The system of claim 11 , wherein the three-dimensional tomography comprises an image of an object in the container.

14. The system of claim 13 , wherein the image is enhanced by varying at least one of an intensity, a neutron-gamma ratio, or an energy spectrum of the dual neutron-gamma ray beam.

15. A method for neutron-gamma ray tomography, the method comprising:

illuminating an object with a plurality of dual neutron-gamma ray beams;

measuring a neutron-gamma ray attenuation ratio for each of the dual neutron-gamma ray beams;

imaging the object via tomography performed as a function of the neutron and gamma ray attenuation ratio; and

tuning the beam to enhance the tomography.

16. The method of claim 15 , wherein tuning the beam comprises varying at least one of an intensity, a gamma ray intensity, or an energy spectrum.

17. The method of claim 15 , wherein imaging the object further comprises analyzing a material composition of the object as a function of the neutron-gamma attenuation ratio.

18. The method of claim 17 , wherein analyzing a material composition further comprises at least one of prompt gamma activation analysis or neutron activation analysis.