Multilayer X-ray source target with high thermal conductivity

Patent metadata

Field	Value
Publication number	US-9646801-B2
Application number	US-201514682890-A
Country	US
Kind code	B2
Filing date	Apr 9, 2015
Priority date	Apr 9, 2015
Publication date	May 9, 2017
Grant date	May 9, 2017

Abstract

In various embodiments, a multi-layer X-ray source target is provided having two or more layers of target material at different depths and different thicknesses. In one such embodiment the X-ray generating layers increase in thickness in relationship to their depth relative to the electron beam facing surface of the source target, such that X-ray generating layer further from this surface are thick than X-ray generating layers closer to the electron beam facing surface.

First claim

The invention claimed is:

1. An X-ray source, comprising:
an emitter configured to emit an electron beam; and
a target having an emitter-facing surface and configured to generate X-rays when impacted by the electron beam, the target comprising:
two or more X-ray generating layers at different depths relative to the emitter-facing surface, each X-ray generating layer having a different thickness; and
at least one intervening thermally-conductive layer between each pair of X-ray generating layers;
wherein the X-ray generating layers further from the emitter-facing surface are thicker than X-ray generating layers nearer the emitter-facing surface.

2. The X-ray source of claim 1 , wherein the two or more X-ray generating layers comprise one or more regions of an X-ray generating material that produces X-rays when impacted by the electron beam.

3. The X-ray source of claim 1 , wherein two or more of the X-ray generating layers comprise different X-ray generating materials.

4. The X-ray source of claim 1 , comprising at least two intervening thermally-conductive layers differing in one or both of composition or thickness.

5. The X-ray source of claim 1 , wherein the emitter-facing surface comprises a thermally-conductive material.

6. The X-ray source of claim 1 , further comprising a thermally-conductive substrate opposite the emitter-facing surface.

7. The X-ray source of claim 1 , wherein one or more X-ray generating layers comprise a tungsten region and the at least one thermally-conductive layer comprises diamond.

8. The X-ray source of claim 1 , wherein one or more X-ray generating layers comprise an X-ray generating material region having a cross-sectional extent less than the cross-sectional extent of the respective X-ray generating layer.

9. A method for fabricating an X-ray source target, comprising:
forming a first X-ray generating layer, wherein the first X-ray generating layer has a first thickness;
on the first X-ray generating layer, forming one or more sets of:
an intervening thermally-conductive layer; and
an additional X-ray generating layer, wherein each X-ray generating layer has a different thickness than other X-ray generating layers; wherein each additional X-ray generating layer formed over the first X-ray generating layer is less thick than those X-ray generating layers formed prior.

10. The method of claim 9 , wherein the first X-ray generating layer is formed on a thermally-conductive substrate.

11. The method of claim 9 , wherein forming the first X-ray generating layer comprises forming the first X-ray generating layer on a thermally-conductive substrate.

12. The method of claim 9 , wherein the step of forming one or more sets of an intervening layer and an additional X-ray generating layer comprises forming more than one set of said layers, and wherein the thermally conductive layer of one set has a different thickness than the thermally conductive layer of another set.

13. The method of claim 12 , wherein forming one or both of the first X-ray generating layer or the additional X-ray generating layers comprises forming a continuous X-ray generating material region across the full cross-sectional extent of the respective X-ray generating layer.

14. The method of claim 12 , wherein forming one or both of the first X-ray generating layer or the additional X-ray generating layers comprises forming an X-ray generating material region across less than the full cross-sectional extent of the respective X-ray generating layer and forming one or more thermally-conductive regions across the remainder of the respective X-ray generating layer.

Assignees

• Gen Electric

Inventors

• Dalakos George Theodore
• Frontera Mark Alan
• Robinson Vance Scott
• Ross William Robert
• Zhang Xi

Classifications

• H01J2235/1204

  of the anode · CPC title

• H01J2235/1291

  Thermal conductivity · CPC title

• H01J2235/088

  Laminated targets, e.g. plurality of emitting layers of unique or differing materials · CPC title

• H01J35/12 Primary

  Cooling non-rotary anodes · CPC title

• H01J2235/1233

  characterised by the material · CPC title