X-ray source with rotating anode at atmospheric pressure

Patent metadata

Field	Value
Publication number	US-11152183-B2
Application number	US-202016920520-A
Country	US
Kind code	B2
Filing date	Jul 3, 2020
Priority date	Jul 15, 2019
Publication date	Oct 19, 2021
Grant date	Oct 19, 2021

Abstract

An x-ray source includes an anode assembly having at least one surface configured to rotate about an axis, the at least one surface in a first region. The x-ray source further includes an electron-beam source configured to emit at least one electron beam configured to bombard the at least one surface of the anode assembly. The electron-beam source includes a housing, a cathode assembly, and a window. The housing at least partially bounds a second region and comprises an aperture. The cathode assembly is configured to generate the at least one electron beam within the second region. The window is configured to hermetically seal the aperture, to maintain a pressure differential between the first region and the second region, and to allow the at least one electron beam to propagate from the second region to the first region.

First claim

What is claimed is:

1. An x-ray source comprising:
an anode assembly comprising at least one surface configured to rotate about an axis, the at least one surface in a first region;
an electron-beam source configured to emit at least one electron beam configured to bombard the at least one surface of the anode assembly, the electron-beam source comprising:
a housing at least partially bounding a second region, the housing comprising an aperture;
a cathode assembly configured to generate the at least one electron beam within the second region; and
a window configured to hermetically seal the aperture, to maintain a pressure differential between the first region and the second region, and to allow the at least one electron beam to propagate from the second region to the first region, the window spaced from the at least one surface by a distance in a range of 1 millimeter to 5 millimeters.

2. The x-ray source of claim 1 , wherein the window has a thickness in a range of 0.1 micron to 10 microns and a width in a range of 10 microns to 2000 microns.

3. The x-ray source of claim 1 , wherein the window comprises at least one material in the group consisting of: diamond, silicon, silicon nitride, boron nitride, boron carbide, beryllium, titanium, and a combination of two or more thereof.

4. The x-ray source of claim 1 , wherein the first region is at a pressure in a range of 0.8 atmosphere to 1 atmosphere and the second region is at a pressure less than atmospheric pressure.

5. The x-ray source of claim 4 , wherein the first region comprises air, nitrogen, and/or helium.

6. The x-ray source of claim 1 , further comprising an enclosure at least partially bounding the first region, the enclosure substantially opaque to x-rays emitted from the at least one surface in response to being bombarded by the at least one electron beam, the enclosure comprising a portion that is substantially transparent to at least some of the x-rays emitted from the at least one surface in response to being bombarded by the at least one electron beam.

7. The x-ray source of claim 1 , wherein the anode assembly comprises:
a shaft configured to rotate about the axis; and
an anode mechanically coupled to the shaft, the anode comprising the at least one surface.

8. The x-ray source of claim 7 , wherein the anode assembly further comprises:
at least one motor mechanically coupled to the shaft and configured to rotate the shaft; and
a plurality of bearing assemblies configured to support the shaft.

9. The x-ray source of claim 8 , wherein the at least one motor comprises at least one rotor mechanically coupled to the shaft and at least one stator in magnetic communication with the at least one rotor.

10. The x-ray source of claim 8 , wherein the plurality of bearing assemblies comprises a first bearing assembly coupled to a first portion of the shaft and a second bearing assembly coupled to a second portion of the shaft, the anode mechanically coupled to a third portion of the shaft between the first portion and the second portion.

11. The x-ray source of claim 7 , further comprising a cooling subsystem in thermal communication with the anode, the cooling subsystem configured to remove heat from the at least one surface at a rate in a range of 100 watts to 5 kilowatts.

12. The x-ray source of claim 11 , wherein the cooling subsystem comprises a nozzle configured to spray coolant onto the at least one surface and/or channels extending within the anode and configured to allow coolant to flow through the channels in thermal communication with the anode.

13. An x-ray source comprising:
a first assembly comprising at least one surface configured to rotate about an axis, the at least one surface in a first region, the first assembly configured to generate x-rays in response to electron bombardment of the at least one surface;
an electron-beam source configured to emit at least one electron beam configured to bombard the at least one surface of the first assembly, the electron-beam source comprising:
a housing at least partially bounding a second region, the housing comprising an aperture;
a second assembly comprising at least one electron emitter and an electron optics subsystem, the second assembly configured to generate the at least one electron beam within the second region; and
a window configured to hermetically seal the aperture, to maintain a pressure differential between the first region and the second region, and to allow the at least one electron beam to propagate from the second region to the first region, the window spaced from the at least one surface by a distance in a range of 1 millimeter to 5 millimeters.

14. The x-ray source of claim 13 , wherein the window comprises at least one material in the group consisting of: diamond, silicon, silicon nitride, boron nitride, boron carbide, beryllium, titanium, and a combination of two or more thereof.

15. The x-ray source of claim 13 , wherein the window has a thickness in a range of 0.1 micron to 10 microns and a width in a range of 10 microns to 2000 microns.

16. The x-ray source of claim 13 , wherein the first assembly comprises a shaft configured to rotate about the axis and the at least one surface is mechanically coupled to the shaft.

17. The x-ray source of claim 16 , wherein the first assembly further comprises:
at least one motor mechanically coupled to the shaft and configured to rotate the shaft; and
a plurality of bearing assemblies configured to support the shaft.

18. The x-ray source of claim 13 , further comprising a cooling subsystem configured to remove heat from the at least one surface at a rate in a range of 100 watts to 5 kilowatts.

19. The x-ray source of claim 18 , wherein the cooling subsystem comprises a nozzle configured to spray coolant onto the at least one surface and/or channels configured to allow coolant to flow through the channels in thermal communication with the at least one surface.

Assignees

• Sigray Inc

Inventors

• Kirz Janos
• Hansen William Henry
• Yun Wenbing

Classifications

• H01J35/20

  Selection of substances for gas fillings; Means for obtaining or maintaining the desired pressure within the tube, e.g. by gettering · CPC title

• H01J33/04

  Windows · CPC title

• H01J35/106 Primary

  Active cooling, e.g. fluid flow, heat pipes · CPC title

• H01J2235/127

  Control of flow · CPC title

• H01J35/18 Primary

  Windows · CPC title