Linear array detector system and inspection method

• US 7,236,564 B2
• Filed: 09/12/2006
• Issued: 06/26/2007
• Est. Priority Date: 09/30/2004
• Status: Expired due to Fees

• Current Assignee: General Electric Company
• Original Assignee: General Electric Company
• Inventors: Hopkins, Forrest Frank, Ross, William Robert, Galish, Andrew Joseph
• Primary Examiner(s): Glick; Edward J.
• Assistant Examiner(s): Yun; Jurie
• Application Number:
  US11/519,271
• Publication Number:
  US 20070034805A1
• Time in Patent Office: 287 Days
• Field of Search: 378/19, 378/53, 378 57- 59, 378/62, 378/98.8, 378/98.9, 250/366
• US Class Current: 378/57
• CPC Class Codes: G01T 1/20185 Coupling means between the photodiode and the scintillator, e.g. optical couplings using adhesives with wavelength-shifting fibres

Abstract

A linear array detector (LAD) for scanning an object is provided. The detector includes a scintillator layer configured for generating a number of optical signals representative of a fraction of an incident X-ray beam passing through the object. The plane of the scintillator is parallel to the X-ray beam. The LAD further includes a two dimensional array of photo-conversion elements configured to receive several X-rays of the X-ray beams and configured to generate corresponding electrical signals. An arrangement of the photo-conversion elements is independent of the X-ray paths.

Claims

1. A system for scanning an object having an arbitrary geometry, the system comprising:

at least one detector configured for generating electrical signals representative of an incident X-ray beam passing through the object, wherein the detector comprises a scintillator and a two dimensional array of photo-conversion elements; and

a processor coupled to the detector and configured to;

determine an X-ray path geometry from the two dimensional array, wherein the X-ray path geometry comprises at least one X-ray path, and wherein the X-ray path passes through at least one of the photo-conversion elements,

determine an energy deposition profile for at least one segment of each of the at least one X-ray path, and

generate an image of the object based on the energy deposition profile and the X-ray paths.

2. The system of claim 1, wherein the processor is configured to determine the X-ray path geometry based on imaging at least one fiducial.

3. The system of claim 2, wherein the processor is further configured to bin the energy deposition profile into at least two segments of deposition.

4. The system of claim 3, wherein the processor is further configured to determine a plurality of optimal segments of energy deposition for an application in a post-data acquisition fashion.

5. The system of claim 4, wherein the processor is configured to perform a search to determine a dependence of at least one of an image quality and a material-specific detectability on the X-ray path geometry.

6. The system of claim 5, wherein the application corresponds to an object size, an object type, and a source energy.

7. The system of claim 1, wherein the system is used for at least one of non-destructive evaluation and explosives detection.

8. The system of claim 1, wherein the system is a computed tomography system.

9. The system of claim 1, wherein the system is a digital radiography system.

10. An inspection method for inspecting an object, the method comprising;

impinging an incident X-ray beam on the object;

receiving the X-ray beam passing through the object with a detector, the detector comprises a scintillator and a two dimensional array of photo-conversion elements, wherein the scintillator is aligned parallel to the X-ray beam;

determining an X-ray path geometry from the two dimensional array, wherein the X-ray path geometry comprises at least one X-ray path;

determining an energy deposition profile for at least one segment of each of the at least one X-ray path; and

generating an image of the object using the at least one X-ray path and the energy deposition profile.

11. The inspection method of claim 10, wherein determining the X-ray path geometry includes imaging at least one fiducial.

12. The inspection method of claim 10, further comprising binning the energy deposition profile into at least two segments of deposition, wherein each of the segments of deposition corresponds to a respective x-ray energy level.

13. The inspection method of claim 12, wherein the segments comprise contiguous segments of deposition.

14. The inspection method of claim 12, wherein the segments comprise non-contiguous segments of deposition.

15. The inspection method of claim 12, wherein the energy deposition profile is binned into a first and a second segment of deposition, the first segment corresponding to low-energy X-rays and the second segment corresponding to high-energy X-rays.

16. The inspection method of claim 15, further comprising processing the image using the energy deposition profile corresponding to the high-energy X-rays and to the low-energy X-rays to provide a material-specific detection capability.

17. The inspection method of claim 10, wherein the method is adapted for use in non-destructive evaluation (NDE) of materials.

18. The inspection method of claim 17, wherein the NDE of materials include evaluation of turbine airfoils and turbine blades.

19. The inspection method of claim 17, wherein the NDE of materials include the determination of corrosion and inclusions.

20. The inspection method of claim 17, wherein the NDE of materials include the detection of debris inside a pipe, wherein the pipe is used for transporting water, gas, or oil.

21. The inspection method of claim 10, wherein the method is adapted for use in at least one of baggage inspection, cargo inspection and explosives detection.

22. The inspection method of claim 10, wherein the method is adapted for use in digital radiography systems.

23. The inspection method of claim 10, wherein the method is adapted for use in computed tomography systems.

24. The inspection method of claim 10, wherein the detector has a field of view, the method further comprising:

selecting a source to detector distance for optimal scanning of the object by the detector based on the field of view for the detector; and

positioning the detector and the object at the source to detector distance prior to performing the impinging step.