Method and apparatus for the identification of lithospheric or shielded material deposits by doppler-shifted response photon spectra from interrogation by ionizing radiation

• US 20090272906A1
• Filed: 04/22/2009
• Published: 11/05/2009
• Est. Priority Date: 05/03/2008
• Status: Active Grant

• Current Assignee: Luca Joseph Gratton
• Original Assignee: Luca Joseph Gratton
• Inventors: Gratton, Luca Joseph
• Granted Patent: US 8,193,504 B2
• Time in Patent Office: Days
• US Class Current: 250/370.50
• CPC Class Codes: G01T 3/00 Measuring neutron radiation G01T5/00 takes precedence
• CPC Class Codes: G01V 5/0008 Detecting hidden objects, e.g. weapons, explosives sorting of materials or articles according to radioactive properties B07C5/342; investigating or analysing materials by the use of wave or particle radiation G01N23/00
• CPC Class Codes: G01V 5/0069 Measuring induced radiation, e.g. thermal neutron activation analysis investigating or analysing materials by the use of neutrons G01N23/222
• CPC Class Codes: G01V 5/20 Detecting prohibited goods, e.g. weapons, explosives, hazardous substances, contraband or smuggled objects
• CPC Class Codes: G01V 5/234 Measuring induced radiation, e.g. thermal neutron activation analysis

Abstract

A method and apparatus for the remote, non-invasive detection or characterization of materials manifests a controlled temperature perturbation to the sample material location concurrently with sample interrogation by ionizing radiation and with detection of the response emission energy spectra. This configuration induces and detects Doppler effects manifested at the sample location, allowing material inventory and composition measurements, and allowing a comparative reduction of the exposure duration compared to other isothermal proportional count, coincidence count or spectral analysis techniques. The method and apparatus apply primarily to the detection of elements and isotopes in baggage handling, cargo inspection, chemical characterization, process control and geologic operations, though the method and apparatus are not restricted to these applications. Though the magnitudes of the measured effects are substance specific, the contributing physical processes are not strictly material dependent, allowing method and apparatus applications to almost any high-energy photon-emitting material in multiple applications.

Claims

1. A method for the remote detection and characterization of materials.

2. A remote material detection and characterization method according to claim 1, comprising the steps of:

a. directing an interrogation neutron beam to irradiate the sample material emplacement or a portion thereof;

b. the generation of a secondary ionizing photon radiation by spontaneous, neutron capture, inelastic neutron scattering, and neutron activation reactions of the interrogation neutron beam with the material at the emplacement location;

c. the detection of secondary photon radiations emitted from the sample material emplacement at a location adjacent to the location where the interrogation neutrons are generated;

d. the conversion of interaction events by secondary photons, including those emitted from the sample material emplacement location, with the detector materials to electrical impulses;

e. a means of processing the detector electrical response signals to generate spectral information by cataloging the actuarial detection frequency or cumulative event count in specific incident photon energy intervals;

f. a means for remotely changing the temperature of the sample material emplacement in a controlled fashion;

g. a means of assessing changes produced by sample material emplacement temperature perturbations to the spectral information generated from the detector outputs to calculate or infer the mass inventory and composition of material at the sample emplacement.

3. A method as in claim 2, wherein an interrogation photon beam is directed to irradiate the sample material emplacement or a portion thereof.

4. A method as in claim 2, wherein a secondary ionizing photon radiation occurs by capture, inelastic scatter, spontaneous, or photo-nuclear reactions of an interrogation photon beam with the material at the emplacement location.

5. An apparatus for the remote detection and characterization of materials.

6. A remote material detection and characterization apparatus according to claim 5, with said apparatus comprising:

a. a neutron source having a neutron beam controller and collimator that collectively operate to provide a unidirectional interrogation neutron beam of selected energy that can be operated in pulsed or continuous modes;

b. a transportable platform that bears the neutron source and beam controller, and allows directional adjustment of the emitted interrogation neutron beam to aim said beam towards the sample material emplacement;

c. a measurement detector array disposed on the platform to intercept photons generated at the sample emplacement location;

d. a diagnostic detection system composed of multiple neutron detectors disposed on-the platform to gauge interrogation source operation status;

e. a signal processor and analyzer system that communicates with the measurement and diagnostic detectors to receive the detector output signals, process said signals to generate both system status, and spectral information by cataloging the actuarial detection frequency or cumulative event count in specific incident photon and neutron energy intervals, and to compare and manipulate said spectra in manners specified by the user for the purpose of system-keeping, sample material inventory and composition measurement;

f. a neutron beam generated by the neutron source that additionally functions as a thermal perturbation system by inducing material temperature changes at the sample emplacement in a controlled and measured fashion;

g. a thermal management system disposed on the platform for the purpose of stabilizing temperatures of detectors and other sensitive components;

h. a transmitter/receiver system disposed on the platform and capable of operational command and data transfer communications;

i. power cabling for the provision of externally supplied electrical power to electrically energized components disposed on the platform;

j. a central controller system disposed on the platform that regulates, starts, stops and implements operational setpoints for the interrogation neutron beam, diagnostic detector system, measurement detector system, thermal perturbation system, thermal management system and transmitter/receiver system;

k. radiation shielding disposed on the platform to screen radiation-sensitive components;

l. cabling for electrical connectivity among components disposed on the platform;

m. fasteners for mounting components disposed on the platform to the platform.

7. An apparatus as in claim 6, wherein the neutron source is a D-T neutron generator.

8. An apparatus as in claim 6, wherein the neutron source is an encapsulated isotopic neutron emitter.

9. An apparatus as in claim 6, wherein the neutron source is an encapsulated isotopic alpha emitter embedded in neutron-generating matrix material.

10. An apparatus as in claim 6, wherein the neutron source is an encapsulated isotopic photoneutron source.

11. An apparatus as in claim 6, wherein the neutron source is an electron beam accelerator with a neutron-generating target.

12. An apparatus as in claim 6, wherein the neutron source is fitted with a beam chopper-plate device.

13. An apparatus as in claim 6, wherein a photon source having a photon beam controller operates to provide a unidirectional interrogation photon beam of selected energy that can be operated in pulsed or continuous modes.

14. An apparatus as in claim 6, wherein a photon source having a photon beam controller is disposed in the form of an electron accelerator fitted with a photon-generating converter material and beam diverter.

15. An apparatus as in claim 6, wherein the measurement detectors are arranged in a common plane as a monolithic structure with a cavity at the center comprising a beam port.

16. An apparatus as in claim 6, wherein the measurement detectors are arranged in a common plane as a monolithic structure capable of orientation adjustments on two perpendicular axes residing in the plane of the detector array for the purpose of aiming the apparatus.

17. An apparatus as in claim 6, wherein the measurement detector system is comprised of high-purity Germanium detectors.

18. An apparatus as in claim 6, wherein the measurement detector system is comprised of semiconductor detectors using a material other than high-purity Germanium.

19. An apparatus as in claim 6, wherein the measurement detector system is comprised of Sodium Iodide detectors.

20. An apparatus as in claim 6, wherein the measurement detector system is comprised of scintillation detectors using a material other than Sodium Iodide.

21. An apparatus as in claim 6, wherein the diagnostic detector system is comprised of a combination of Helium-3 and Helium-4 pressurized gas detectors.

22. An apparatus as in claim 6, wherein the central controller system is a programmable microprocessor.

23. An apparatus as in claim 6, wherein Polyethylene shielding is disposed.

24. An apparatus as in claim 6, wherein Lead shielding is disposed.

25. An apparatus as in claim 6, wherein Tungsten shielding is disposed.

26. An apparatus as in claim 6, wherein the thermal management system comprises distributed thermocouples, distributed evaporators, a programmable controller, distributed actuators, a vapor compression and heat rejection unit, refrigerant ducting, and Argon refrigerant.

27. An apparatus as in claim 6, wherein the thermal management system comprises distributed thermocouples, distributed evaporators, a programmable controller, distributed actuators, a vapor compression and heat rejection unit, refrigerant ducting, and Nitrogen refrigerant.

28. An apparatus as in claim 6, wherein the thermal management system comprises distributed thermocouples, distributed evaporators, a programmable controller, distributed actuators, a vapor compression and heat rejection unit, refrigerant ducting, and Carbon Dioxide refrigerant.

29. An apparatus as in claim 6, wherein the thermal management system comprises distributed thermocouples, distributed actuators, a power supply, electric wire leads, and distributed solid-state electronic cooling pads.

30. An apparatus as in claim 6, wherein the means for inducement of the thermal perturbation to the sample material at the emplacement is the interrogation neutron beam generated by a neutron source.

31. An apparatus as in claim 6, wherein the means for inducement of the thermal perturbation to the sample material at the emplacement is the interrogation photon beam generated by a photon source.

32. An apparatus as in claim 6, wherein the means for inducement of the thermal perturbation to the sample material at the emplacement is an ultrasonic acoustic generator.

33. An apparatus as in claim 6, wherein the means for inducement of the thermal perturbation to the sample material at the emplacement is a sonic acoustic generator.

34. An apparatus as in claim 6, wherein the means for inducement of the thermal perturbation to the sample material at the emplacement is a shock-tube or pressure generator.

35. An apparatus as in claim 6, wherein the means for inducement of the thermal perturbation to the sample material at the emplacement is a microwave generator.

36. An apparatus as in claim 6, wherein the means for inducement of the thermal perturbation to the sample material at the emplacement is a visible wavelength laser generator.

37. An apparatus as in claim 6, wherein the means for inducement of the thermal perturbation to the sample material at the emplacement is an infrared wavelength laser generator.

38. An apparatus as in claim 6, wherein the means for inducement of the thermal perturbation to the sample material at the emplacement is an electrical resistance heating device consisting of a current or voltage generator, electrical cable leads, electrodes, and the use of the sample emplacement material region as an effective electrical resistance element.

39. An apparatus as in claim 6, wherein the means for inducement of the thermal perturbation to the sample material at the emplacement is an electromagnetic induction device consisting of a current generator, a conductive induction winding that enshrouds the emplacement location, and the use of the sample and the material surrounding the emplacement as the inductor core plug material.

40. An apparatus as in claim 6, wherein the means for inducement of the thermal perturbation to the sample material at the emplacement is a spatial heating device or fluid in direct contact with the sample material at the emplacement location.