X-ray system with field emitter and arc protection

Abstract

To inhibit a field emitter from being deteriorated or broken by arcing in an x-ray tube.SOLUTION: An x-ray tube comprises: a field emitter including an emission surface; an anode; and a focus electrode disposed between the field emitter and the anode. The focus electrode includes: a first surface that is substantially perpendicular to the field emitter emission surface and nearest to the field emitter; a second surface that is axially nearest to the anode, where the field emitter and the anode form an axis; a third surface that extends between the first surface and the second surface; and a first location on the focus electrode between the first surface and the third surface, the first location being farther from the anode than a second location on the focus electrode between the third surface and the second surface.SELECTED DRAWING: None

Claims

1. A field emitter having an emission surface, A-scatter, A focusing electrode is disposed between the field emitter and the anode, An X-ray tube including, The aforementioned focusing electrode is The first surface is substantially perpendicular to the emission surface of the field emitter and is closest to the field emitter, The second surface is the closest to the anode in the axial direction, and the field emitter and the anode form an axis with respect to the second surface, A third surface extending between the first surface and the second surface, A first position on the focusing electrode between the first surface and the third surface, which is further from the anode than a second position on the focusing electrode between the third surface and the second surface, Includes, The focusing electrode further includes a projection extending toward the anode. x-ray tube.

2. The X-ray tube according to claim 1, wherein the second position on the focusing electrode is further from the center of the field emitter than another portion of the focusing electrode.

3. The X-ray tube according to claim 1, wherein the focusing electrode is grounded.

4. The X-ray tube according to claim 1, wherein the protrusion is closer to the second position on the focusing electrode and the anode than to the first position on the focusing electrode.

5. The X-ray tube according to claim 1, wherein the focusing electrode is shaped such that the point of maximum electric field strength is located at the second position during operation.

6. The X-ray tube according to claim 1, wherein the second surface extends radially and axially away from the first surface with respect to the axis.

7. The substrate on which the field emitter is arranged, A frame disposed on the substrate on the field emitter, The focusing electrode is positioned on the frame, An X-ray tube according to any one of claims 1 to 6, further comprising a cathode structure having the

8. The field emitter is one of a plurality of field emitters arranged on the substrate, The frame includes a plurality of openings, each opening corresponding to one of the plurality of field emitters, The focusing electrode includes a first part and a second part, The X-ray tube according to claim 7, wherein the opening of the frame is positioned between the first portion and the second portion.

9. The X-ray tube according to claim 1, wherein the points on the second surface are substantially equidistant from the anode.

10. A cathode structure having an electric field emitter, A-scatter, A focusing electrode is positioned between the field emitter and the anode and includes a projection extending toward the anode, An X-ray tube including, An X-ray tube in which the focusing electrode is positioned relative to the field emitter and the anode, and the focusing electrode is shaped such that, during operation, the highest point of the electric field strength on the cathode structure becomes closer to the focusing electrode than to the field emitter and is positioned on the protruding portion of the focusing electrode.

11. The X-ray tube according to claim 10, wherein the point of maximum electric field strength is located further from the center of the field emitter than another part of the focusing electrode.

12. The X-ray tube according to claim 10, wherein the focusing electrode is grounded.

13. The field emitter and the anode form an axis, The aforementioned focusing electrode is A first surface extending substantially parallel to the aforementioned axis, A second surface extending radially away from the first surface with respect to the axis, An X-ray tube according to any one of claims 10 to 12, including the X-ray tube according to any one of claims 10 to 12.

14. The first position on the focusing electrode is located between the first surface and the second surface. The X-ray tube according to claim 13, wherein the focusing electrode is shaped such that the point of maximum electric field strength is located at the first position during operation.

15. The field emitter and the anode form an axis, The aforementioned focusing electrode is A first surface extending substantially parallel to the aforementioned axis, A second surface extending radially away from the first surface with respect to the axis, A third surface extending radially and axially toward the second surface, away from the first surface with respect to the axis, A first position on the focusing electrode located between the first surface and the third surface, A second position on the focusing electrode located between the third surface and the second surface, An X-ray tube according to any one of claims 10 to 12, including the X-ray tube according to any one of claims 10 to 12.

16. The X-ray tube according to claim 15, wherein the focusing electrode is shaped such that the point of maximum electric field strength is located at the second position during operation.

17. The X-ray tube according to claim 13, wherein the points on the second surface are substantially equidistant from the anode.

18. A means for emitting electrons toward the anode, A means for focusing electrons emitted from the means for emitting electrons toward the anode, A means for increasing the electric field strength in the means for focusing the electrons to exceed the electric field strength in the means for emitting the electrons, the means including a projection extending toward the anode, The means for focusing the electrons, including X-ray tubes, including one.

19. The X-ray tube according to claim 18, wherein the means for focusing electrons further includes means for positioning a point of maximum electric field strength on the means for focusing electrons that is further away from the means for emitting electrons than the portion of the means for focusing electrons that is closest to the means for emitting electrons.

20. Each field emitter has an emission surface, and comprises a plurality of field emitters, A-scatter, A focusing electrode is disposed between at least one of the plurality of field emitters and the anode, A substrate on which at least one of the plurality of field emitters is disposed, A frame disposed on the substrate on at least one of the plurality of field emitters, Includes, The focusing electrode is positioned on the frame, Cathode structure and An X-ray tube including, The aforementioned focusing electrode is The first surface is substantially perpendicular to the emission surface of the plurality of field emitters and is closest to the at least one of the plurality of field emitters, The second surface is the closest in the axial direction to the anode, and at least one of the plurality of field emitters and the anode form an axis with respect to the second surface, A third surface extending between the first surface and the second surface, A first position on the focusing electrode between the first surface and the third surface, which is further from the anode than a second position on the focusing electrode between the third surface and the second surface, Includes, The frame includes a plurality of openings, each opening corresponding to one of the plurality of field emitters, The focusing electrode includes a first part and a second part, The opening of the frame is located between the first portion and the second portion. x-ray tube.

Images