Methods and systems for rapid detection of concealed objects using fluorescence

• US 7,856,081 B2
• Filed: 03/13/2008
• Issued: 12/21/2010
• Est. Priority Date: 09/15/2003
• Status: Expired due to Term

• Current Assignee: Rapiscan Systems Incorporated (OSI Systems Incorporated)
• Original Assignee: Rapiscan Systems Incorporated (OSI Systems Incorporated)
• Inventors: Peschmann, Kristian R.
• Primary Examiner(s): Yun; Jurie
• Application Number:
  US12/047,472
• Publication Number:
  US 20090010386A1
• Time in Patent Office: 1,013 Days
• Field of Search: 378/57, 378/58, 378 44- 46, 378 70- 90
• US Class Current: 378/57
• CPC Class Codes: G01N 2223/076 X-ray fluorescence
• CPC Class Codes: G01N 23/20 by using diffraction of the radiation by the materials, e.g. for investigating crystal structure; by using scattering of the radiation by the materials, e.g. for investigating non-crystalline materials; by using reflection of the radiation by the materials
• CPC Class Codes: G01N 23/20083 by using a combination of at least two measurements at least one being a transmission measurement and one a scatter measurement
• CPC Class Codes: G01N 23/223 by irradiating the sample with X-rays or gamma-rays and by measuring X-ray fluorescence
• CPC Class Codes: G01V 5/00 Prospecting or detecting by the use of ionising radiation, e.g. of natural or induced radioactivity
• CPC Class Codes: G01V 5/222 measuring scattered radiation
• CPC Class Codes: G01V 5/224 Multiple energy techniques using one type of radiation, e.g. X-rays of different energies
• CPC Class Codes: G01V 5/226 using tomography
• CPC Class Codes: G01V 5/228 using stereoscopic means
• CPC Class Codes: G01V 5/281 detecting special nuclear material [SNM], e.g. Uranium-235, Uranium-233 or Plutonium-239

Abstract

This invention is directed towards finding, locating, and confirming threat items and substances. The inspection system is designed to detect objects that are made from, but not limited to, special nuclear materials (“SNM”) and/or high atomic number materials. The system employs advanced image processing techniques to analyze images of an object under inspection (“OUI”), which includes, but is not limited to baggage, parcels, vehicles and cargo, and fluorescence detection.

Claims

1. A system for inspecting a target object using a radiation source, comprising:

a substantially C-shaped structure, said C-shaped structure having a first arm, with a first proximal end and a first distal end, and a second arm, with a second proximal end and a second distal end, wherein a) said first proximal end and second proximal end are attached by a connecting member, b) a plurality of detectors, said detectors comprising at least one diffraction detector, are positioned at said first distal end, and c) said second arm comprises a radiation source for projecting an X-ray beam toward the target object and a fluorescence detector head in an angular relationship to said radiation source; and

a conveyor for positioning said target object between said first arm and said second arm.

2. The system of claim 1 further comprising:

a first stage inspection system having a scanning system to generate a first set of data and a plurality of processors in data communication with the first stage inspection system wherein the processors process said first set of data and wherein the first set of data is used to identify at least one target region.

3. The system of claim 2 further comprising:

a second stage inspection system for generating an inspection region wherein the second stage inspection system comprises said C-shaped structure.

4. The system of claim 3 wherein the second stage inspection system produces a second set of data having an X-ray signature characteristic of the material in said inspection region and a third set of data having a fluorescence signature characteristic of the material in said inspection region.

5. The system of claim 4 further comprising a processor that outputs a ratio of an attenuation caused by said material to a size of said material, based upon said second set of data having an X-ray signature characteristic and said third set of data having a fluorescence signature characteristic.

6. The system of claim 5 wherein said processor, using said ratio, outputs a determination of whether the material is a nuclear material.

7. The system of claim 6 further comprising at least one display for generating an image of said target object.

8. The system of claim 7 further comprising a memory and a plurality of instructions stored within said memory wherein said instructions, when executed by said processor, analyze the image to evaluate regions of objects based upon a threshold level and segment said image into regions based upon criteria.

9. The system of claim 8 wherein said instructions, when executed by said processor, also direct the system to further inspect selected regions satisfying certain criteria to determine their size and shape and compare said selected regions to threat criteria.

10. The system of claim 9 wherein said instructions, when executed by said processor, also cause the system to issue an alarm when said target object is determined to match said threat criteria.

11. The system of claim 5 wherein the X-ray signature characteristic is at least one of mass, degree of attenuation, area, atomic number, size, shape, pattern, or context.

12. The system of claim 2 wherein a plurality of X-ray beam projections intersects the target region at an intersection area, said target region having a location.

13. The system of claim 12 wherein the location of the target region is determined by said processor identifying a set of coordinates for the intersection area.

14. The system of claim 13 wherein a plurality of control commands is produced by said processor in response to the determination of said location of the target region.

15. The system of claim 14 further comprising:

a second stage inspection system for generating an inspection region wherein the second stage inspection system comprises said C-shaped structure and wherein the inspection region is positioned relative to the target region in response to the plurality of control commands using a three-axis control system.

16. The system of claim 15 wherein the inspection region is positioned relative to the target region by said conveyor operable to move in elevation relative to the second stage inspection system.

17. The system of claim 2 wherein said first set of data is used to identify a reference spectrum.

18. The system of claim 17 wherein the reference spectrum is used to correct a diffraction spectrum.

19. The system of claim 17 wherein the reference spectrum is used to correct for beam hardening.

20. The system of claim 1 further comprising a bypass conveyor capable of moving said object into a secured area without first passing between said first arm and said second arm.