X-ray scanners and X-ray sources therefor

• US 9,048,061 B2
• Filed: 12/02/2013
• Issued: 06/02/2015
• 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): Artman, Thomas R
• Application Number:
  US14/094,603
• Publication Number:
  US 20140161220A1
• Time in Patent Office: 547 Days
• US Class Current: 1/1
• 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 first electron source configured to generate a first electron beam;

and

an anode having a target surface comprising a first material and a second material, wherein

said first material is different from said second material,

said first material and second material form a pattern on said target surface, the pattern comprising an elongated strip of the first material alternating with an elongated strip of the second material to form an array of alternating target areas in a ring around said scanner,

the first electron source is configured to irradiate a strip of both the first material and second material simultaneously.

2. The X-ray scanner of claim 1 wherein the first and second material are formed of a uniform material.

3. The X-ray scanner of claim 1 wherein, upon irradiating the strip of both the first material and second material simultaneously, a composite X-ray spectrum is generated having an energy spectrum that is a sum of a spectra of the first material and a spectra of the second material.

4. The X-ray scanner of claim 1 further comprising a second electron source configured to generate a second electron beam.

5. The X-ray scanner of claim 1 wherein the first material area comprises a strip that extends in a direction parallel to the scanning direction.

6. The X-ray scanner of claim 1 wherein the second material area comprises a strip that extends in a direction parallel to the scanning direction.

7. The X-ray scanner of claim 1 wherein the first material area comprises a strip that extends in a direction which is oblique to the scanning direction.

8. The X-ray scanner of claim 1 wherein the second material area comprises a strip that extends in a direction which is oblique to the scanning direction.

9. The X-ray scanner of claim 1 wherein the first material area comprises a strip that extends in a direction which is transverse to the scanning direction.

10. The X-ray scanner of claim 1 wherein the second material area comprises a strip that extends in a direction which is transverse to the scanning direction.

11. The X-ray scanner of claim 1 wherein the first or second material area comprises a thin film of metal.

12. The X-ray scanner of claim 1 further comprising detectors, wherein the detectors comprise a first set of detectors and a second set of detectors and wherein, relative to said second set of detectors, the first set of detectors is more sensitive to X-rays over a spectra generated from irradiating the first material, and, relative to said first set of detectors, the second set of detectors is more sensitive to X-rays over a spectra generated from irradiating the second material.

13. The X-ray scanner of claim 12 wherein the second set of detectors comprises a filter material and a detector element.

14. The X-ray scanner of claim 1 further comprising detectors, wherein the detectors comprise a first set of detectors and a second set of detectors and wherein said first set of detectors has a different response characteristic from said second set of detectors and wherein the first set of detectors is configured to receive X-rays of a first energy spectra and the second set of detectors is configured to receive X-rays of a second energy spectra.

15. The X-ray scanner of claim 1 wherein the first and second materials are each arranged to generate X-rays having an intensity peak at two different respective fluorescent energies, and a filter material is arranged to provide different attenuations at the two fluorescent energies.

16. The X-ray scanner of claim 15 wherein the filter material has an absorption edge at a frequency between the two fluorescent energies.

17. A method of generating X-rays comprising

providing at least one electron source;

providing an anode with a target surface formed with parallel, elongated, alternating sections of at least two different material areas spaced along the target surface in a scanning direction; and

directing an electron beam from the at least one electron source to simultaneously irradiate both of said at least two different material areas to generate an X-ray beam of at least two different energy spectra.

18. The method of generating X-rays of claim 17 further comprising detecting radiation using a first set of detectors and a second set of detectors and wherein said first set of detectors has a different response characteristic from said second set of detectors and wherein the first set of detectors is configured to receive X-rays of a first energy spectra and the second set of detectors is configured to receive X-rays of a second energy spectra.

19. The method of generating X-rays of claim 17 further comprising detecting radiation using a first set of detectors and a second set of detectors and wherein, relative to said second set of detectors, the first set of detectors is more sensitive to X-rays over a spectra generated from irradiating a first of the at least two different material areas, and, relative to said first set of detectors, the second set of detectors is more sensitive to X-rays over a spectra generated from irradiating a second of the at least two different material areas.