X-Ray Scanners and X-Ray Sources Therefor

• US 20100020934A1
• Filed: 06/16/2009
• Published: 01/28/2010
• Est. Priority Date: 12/16/2005
• Status: Active Grant

• Current Assignee: Rapiscan Systems Incorporated (OSI Systems Incorporated)
• Original Assignee: Edward James Morton
• Inventors: Morton, Edward James
• Granted Patent: US 7,949,101 B2
• Time in Patent Office: Days
• US Class Current: 378/124
• CPC Class Codes: A61B 6/4042 K-edge filters
• CPC Class Codes: A61B 6/482 involving multiple energy imaging
• CPC Class Codes: G01N 2223/206 sources operating at different energy levels
• CPC Class Codes: G01N 23/046 using tomography, e.g. computed tomography [CT]
• CPC Class Codes: G01N 23/06 and measuring the absorption
• CPC Class Codes: G01N 23/087 using polyenergetic X-rays
• 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: H01J 2235/086 Target geometry
• CPC Class Codes: H01J 2235/088 Laminated targets, e.g. plurality of emitting layers of unique or differing materials
• CPC Class Codes: H01J 35/112 Non-rotating anodes H01J35/12 takes precedence

Abstract

The present invention is directed toward an X-ray scanner that has an electron source and an anode. The anode has a target surface with a series of material areas spaced along it in a scanning direction. The material areas are formed from different materials. The electron source is arranged to direct electrons at a series of target areas of the target surface, in a predetermined order, so as to generate X-ray beams having different energy spectra.

Claims

1. An X-ray scanner comprising an electron source and an anode, the anode having a target surface with a series of material areas spaced along it in a scanning direction, the material areas being formed from different materials, the electron source being arranged to direct electrons at a series of target areas of the target surface, in a predetermined order, so as to generate X-ray beams having different energy spectra.

2. A scanner according to claim 1, wherein each of the material areas is formed of a uniform material.

3. A scanner according to claim 1 or claim 2 wherein the material areas comprise strips which extend in a direction transverse to the scanning direction.

4. A scanner according to claim 1 or claim 2 wherein the material areas comprise strips extending in a direction which is oblique to the scanning direction.

5. A scanner according to any foregoing claim, wherein the material areas are formed as thin films of target metals.

6. A scanner according to any foregoing claim wherein each of the target areas is within a respective one of the material areas.

7. A scanner according to any of claims 1 to 6 wherein each of the target areas covers part of at least two of the material areas.

8. A scanner according to any foregoing claim further comprising a plurality of detectors arranged to detect the X-rays.

9. A scanner according to claim 8 wherein the detectors are substantially identical.

10. A scanner according to claim 8 wherein the detectors include two sets of detectors arranged to have different responses to X-rays of at least one energy.

11. A scanner according to claim 9 or claim 10 wherein one of the sets of detectors is more sensitive to X-rays over a first range of energies, and the other of the sets of detectors is more sensitive to X-rays over a second range of energies.

12. A scanner according to claim 10 or claim 11 wherein the detectors of one of the sets of detectors includes a filter material and a detector element.

13. A scanner according to any of claims 8 to 12 further comprising processing means arranged to receive signals from the detectors, and to process the signals to generate an output.

14. A scanner according to claim 13 wherein the output is image data set arranged to generate an image.

15. An X-ray scanner comprising an electron source and an anode, the anode having a target surface formed from a plurality of different materials, the electron source being arranged to direct a beam of electrons at the target surface so as to generate, simultaneously, X-rays of two different energy spectra from the two materials, and two detector arrays having different response characteristics.

16. A scanner according to claim 15 wherein the ratio of the responses of one of the detector arrays to X-rays having the two energy spectra of the two materials is different to the ratio of the responses of the other detector array to X-rays having those energy spectra.

17. A scanner according to claim 15 or claim 16 wherein the detectors of one of the arrays of detectors include a filter material and a detector element.

18. A scanner according to claim 17 wherein the two materials are each arranged to generate X-rays having intensity peak at a respective fluorescent energy, and the filter material is arranged to provide different attenuations at the two fluorescent energies.

19. A scanner according to claim 18 wherein the filter material has an absorption edge at a frequency between the two fluorescent energies.

20. A scanner according to any of claims 17 to 19 wherein the detectors of both the detector arrays include identical detector elements

21. A scanner according to any of claims 15 to 20 wherein the target surface has a plurality of material areas each formed from one of the materials, and the electron source is arranged to direct a beam of electrons at a target area of the target, the target area comprising part of at least two of the material areas.

22. A scanner according to claim 21 wherein the electron source is arranged to direct electrons at a plurality of target areas spaced along the target.

23. A scanner according to claim 22 wherein the material areas are arranged as parallel strips each extending through a plurality of the target areas.

24. A scanner according to any of claims 15 to 20 wherein the target surface is formed from a mixture of the materials.