Graphite backscattered electron shield for use in an X-ray tube

• US 9,576,766 B2
• Filed: 11/02/2015
• Issued: 02/21/2017
• Est. Priority Date: 04/25/2003
• Status: Active Grant

• Current Assignee: Rapiscan Systems Incorporated (OSI Systems Incorporated)
• Original Assignee: Rapiscan Systems Incorporated (OSI Systems Incorporated)
• Inventors: Morton, Edward James, Luggar, Russell David, De Antonis, Paul
• Primary Examiner(s): SOUW, BERNARD E
• Application Number:
  US14/930,293
• Publication Number:
  US 20160217966A1
• Time in Patent Office: 477 Days
• Field of Search: 378/119, 378/121, 378/137, 378/128, 378/140, 378/142, 378/143, 378/161, 378/210, 250/370.09, 250/492.3, 250/515.1, 250/529
• US Class Current: 1/1
• CPC Class Codes: H01J 2235/086 Target geometry
• CPC Class Codes: H01J 2235/168 against charged particles
• CPC Class Codes: H01J 35/112 Non-rotating anodes H01J35/12 takes precedence
• CPC Class Codes: H01J 35/16 Vessels; Containers; Shields associated therewith

Abstract

The present invention is a shielded anode having an anode with a surface facing an electron beam and a shield configured to encompass the anode surface. The shield has at least one aperture and an internal surface facing the anode surface. The shield internal surface and anode surface are separated by a gap in the range of 1 mm to 10 mm. The shield of the present invention is fabricated from a material, such as graphite, that is substantially transmissive to X-ray photons.

Claims

1. A shielded anode comprising:

an anode having a surface facing an electron beam and a shield configured to encompass said surface, wherein said shield has at least one aperture, wherein said shield has an internal surface facing said anode surface, and wherein said shield internal surface and said anode surface are separated by a gap.

2. The shielded anode of claim 1 wherein said gap is in the range of 1 mm to 10 mm.

3. The shielded anode of claim 1 wherein said gap is in the range of 1 mm to 2 mm.

4. The shielded anode of claim 1 wherein said gap is in the range of 5 mm to 10 mm.

5. The shielded anode of claim 1 wherein said shield comprises graphite.

6. The shielded anode of claim 1 wherein said shield is removably attached to said anode.

7. The shielded anode of claim 1 wherein said shield comprises a material that has at least 95% transmission for X-ray photons.

8. The shielded anode of claim 1 wherein said shield comprises a material that has at least 98% transmission for X-ray photons.

9. The shielded anode of claim 1 wherein said shield comprises a material that blocks and absorbs backscattered electrons.

10. The shielded anode of claim 1 further comprising more than one aperture.

11. A shielded anode comprising:

an anode having a length and a surface facing an electron beam; and

a shield configured to encompass said surface, wherein said shield has at least one aperture, wherein said shield has an internal surface facing said anode surface, and wherein said shield internal surface and said anode surface are separated by a distance, wherein said distance varies along the length of the anode.

12. The shielded anode of claim 11 wherein said gap is in the range of 1 mm to 10 mm.

13. The shielded anode of claim 11 wherein said gap is in the range of 1 mm to 2 mm.

14. The shielded anode of claim 11 wherein said gap is in the range of 5 mm to 10 mm.

15. The shielded anode of claim 11 wherein said shield comprises graphite.

16. The shielded anode of claim 11 wherein said shield is removably attached to said anode.

17. The shielded anode of claim 11 wherein said shield comprises a material that has at least 95% transmission for X-ray photons.

18. The shielded anode of claim 11 wherein said shield comprises a material that has at least 98% transmission for X-ray photons.

19. The shielded anode of claim 11 wherein said shield comprises a material that blocks and absorbs backscattered electrons.

20. The shielded anode of claim 11 further comprising more than one aperture.