X-ray scanners and X-ray sources therefor

• US 7,949,101 B2
• Filed: 06/16/2009
• Issued: 05/24/2011
• Est. Priority Date: 12/16/2005
• Status: Active Grant

• Current Assignee: Rapiscan Systems Incorporated (OSI Systems Incorporated)
• Original Assignee: Rapiscan Systems Incorporated (OSI Systems Incorporated)
• Inventors: Morton, Edward James
• Primary Examiner(s): Glick; Edward J
• Assistant Examiner(s): Artman; Thomas R
• Application Number:
  US12/485,900
• Publication Number:
  US 20100020934A1
• Time in Patent Office: 707 Days
• Field of Search: 378/124, 378/9, 378/92, 378/98.9, 378/134, 378/137, 378/143, 378/144
• 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 a plurality of electron sources and a plurality of anodes, each anode having a target surface with a series of material areas spaced along the target surface in a scanning direction, the material areas being formed from a first material and a second material, wherein said first material is different from said second material, wherein a first electron source in the plurality of electron sources is arranged to direct a first electron beam at said first material and, simultaneously, a second electron source in the plurality of electron sources is arranged to direct a second electron beam at said second material, so as to concurrently generate X-ray beams having at least two different energy spectra, wherein said first electron beam and said second electron beam are offset by at least 180 degrees.

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 claim 1, wherein the material areas are formed as thin films of target metals.

6. A scanner according to claim 1 further comprising a plurality of detectors arranged to detect the X-ray beams.

7. A scanner according to claim 6 wherein the detectors are substantially identical.

8. A scanner according to claim 6 wherein the detectors include two sets of detectors arranged to have different responses to X-rays of at least one energy.

9. A scanner according to claim 7 or claim 8 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.

10. A scanner according to claim 8 wherein the detectors of one of the sets of detectors includes a filter material and a detector element.

11. A scanner according to claim 6 further comprising a processor arranged to receive signals from the detectors, and to process the signals to generate an output.

12. A scanner according to claim 6 wherein the output is image data set arranged to generate an image.

13. An X-ray scanner comprising a plurality of electron sources and a plurality of anodes, each anode having a target surface formed from at least one first material and at least one second material, wherein said first material is different from said second material, wherein a first electron source in the plurality of electron sources is arranged to direct a first electron beam at said first material and, simultaneously, a second electron source in the plurality of electron sources is arranged to direct a second electron beam at said second material, so as to generate, simultaneously, X-rays of a first energy spectra from the first material and of a second energy spectra from the second material, wherein said first electron beam and said second electron beam are offset by at least 180 degrees, and two detector arrays having different response characteristics, wherein a first detector array in the two detector arrays is configured to receive the X-rays of the first energy spectra and a second detector array in the two detector arrays is configured to receive the X-rays of the second energy spectra.

14. A scanner according to claim 13 wherein detectors of the first detector or second detector arrays include a filter material and a detector element.

15. A scanner according to claim 14 wherein the first and second materials are each arranged to generate X-rays having an intensity peak at a respective fluorescent energy, and the filter material is arranged to provide different attenuations at the two fluorescent energies.

16. A scanner according to claim 15 wherein the filter material has an absorption edge at a frequency between the two fluorescent energies.

17. A scanner according to claim 16 wherein the detectors of the first and second detector arrays include identical detector elements.

18. A scanner according to claim 13 wherein the first and second electron source are arranged to direct electrons at a plurality of materials spaced along the anodes'"'"' target surfaces.

19. A scanner according to claim 18 wherein the materials are arranged as parallel strips each extending through the target surfaces.