X-ray tube with adjustable intensity profile

Patent metadata

Field	Value
Publication number	US-9484179-B2
Application number	US-201213718285-A
Country	US
Kind code	B2
Filing date	Dec 18, 2012
Priority date	Dec 18, 2012
Publication date	Nov 1, 2016
Grant date	Nov 1, 2016

Abstract

An X-ray tube includes an emitter, and an electrode assembly. The emitter is configured to emit an electron beam toward a target. The electrode assembly includes at least one electrode having a bias voltage with respect to the emitter. At least one electrode of the electrode assembly is a segmented electrode including a plurality of segments. The plurality of segments includes a first member and a second member. The first member is configured to have a first bias voltage and the second member is configured to have a second bias voltage that is different from the first bias voltage.

First claim

What is claimed is:

1. An X-ray tube assembly comprising:
an emitter configured to emit an electron beam defining a downstream direction toward a target, the emitter disposed proximate an upstream end of the X-ray tube assembly;
an electrode assembly disposed proximate the emitter and downstream of the emitter, the electrode assembly comprising at least one electrode having a bias voltage with respect to the emitter, the electrode assembly configured to surround the electron beam in an axial direction, wherein the electrode assembly comprises:
an emitter focusing electrode disposed proximate the emitter and outward of the emitter in the axial direction, at least a portion of the emitter focusing electrode overlapping at least a portion of the emitter in the downstream direction;
an extraction electrode disposed proximate the emitter focusing electrode, the extraction electrode disposed downstream of the emitter and the emitter focusing electrode; and
a downstream focusing electrode disposed proximate the extraction electrode and downstream of the extraction electrode, the downstream focusing electrode configured to surround the electron beam in the axial direction, the downstream focusing electrode having a positive bias voltage with respect to the emitter; and

at least one electrode of the electrode assembly being a segmented electrode, the segmented electrode comprising a plurality of segments arranged about an axis defined by the electron beam, the plurality of segments including a first member and a second member, the first member configured to have a first bias voltage and the second member configured to have a second bias voltage that is different from the first bias voltage.

2. The assembly in accordance with claim 1 , wherein the first member and the second member are configured to have independently adjustable bias voltages, the assembly further comprising a control module operably connected to the electrode assembly, the control module configured to control a first bias voltage of the first member and a second bias voltage of the second member, wherein a first beam intensity profile is produced by a first combination of the first bias voltage and the second bias voltage, and wherein a different, second beam intensity profile is produced by a different, second combination of the first bias voltage and the second bias voltage.

3. The assembly in accordance with claim 2 , wherein the segmented electrode comprises an opposed pair comprising the first member and the second member, the first member symmetrically opposed to the second member about the axis defined by the electron beam, the first member and the second member defining an opposed pair axis passing substantially through the center of the first member and the second member, wherein adjusting a voltage bias of the first member relative to a voltage bias of the second member alters a beam intensity profile along the opposed pair axis.

4. The assembly in accordance with claim 3 , wherein the segmented electrode comprises a plurality of opposed pairs, the plurality of opposed pairs defining a substantially continuous geometric shape disposed about the axis defined by the electron beam and defining a plane substantially perpendicular to the electron beam.

5. The assembly in accordance with claim 4 , wherein the segmented electrode defines a ring surrounding the axis defined by the electron beam, the segmented electrode comprising four segments, each segment comprising a substantially circular arcuate segment corresponding to a quadrant of the ring.

6. The assembly in accordance with claim 1 , wherein the extraction electrode is configured as the segmented electrode.

7. The assembly in accordance with claim 6 , wherein the extraction electrode has a negative bias voltage setting wherein at least one segment of the extraction electrode has a negative bias voltage with respect to the emitter at the negative bias voltage setting.

8. The assembly in accordance with claim 1 , wherein the downstream focusing electrode is configured as the segmented electrode.

9. An X-ray tube assembly comprising:
an emitter configured to emit an electron beam defining a downstream direction, the emitter disposed proximate an upstream end of the X-ray tube assembly;
a target disposed proximate a downstream end of the X-ray tube assembly and configured to receive the electron beam emitted from the emitter, the target configured to provide an X-ray beam responsive to a collision of the electron beam with the target;
an electrode assembly disposed proximate the emitter and downstream of the emitter, the electrode assembly comprising at least one electrode having a bias voltage with respect to the emitter, the electrode assembly configured to surround the electron beam in an axial direction, wherein the electrode assembly comprises:
an emitter focusing electrode disposed proximate the emitter and outward of the emitter in the axial direction, at least a portion of the emitter focusing electrode overlapping at least a portion of the emitter in the downstream direction;
an extraction electrode disposed proximate the emitter focusing electrode, the extraction electrode disposed downstream of the emitter and the emitter focusing electrode; and
a downstream focusing electrode disposed proximate the extraction electrode and downstream of the extraction electrode, the downstream focusing electrode configured to surround the electron beam in the axial direction, the downstream focusing electrode having a positive bias voltage with respect to the emitter;

at least one electrode of the electrode assembly being a segmented electrode, the segmented electrode comprising a plurality of segments arranged about an axis defined by the electron beam and substantially surrounding the axis, the plurality of segments including a first member and a second member, the first member and the second member configured to have independently adjustable bias voltages;
a control module operably connected to the electrode assembly, the control module configured to control a first bias voltage of the first member and a second bias voltage of the second member, wherein a first beam intensity profile is produced by a first combination of the first bias voltage and the second bias voltage, and wherein a different, second beam intensity profile is produced by a different, second combination of the first bias voltage and the second bias voltage, the control module configured to adjust the first bias voltage and the second bias voltage to address at least one of an identified artifact or change in procedure; and
a focusing magnet assembly disposed downstream of the electrode assembly and upstream of the target, the focusing magnet assembly configured to deflect or position the electron beam on the target.

10. The assembly in accordance with claim 9 , wherein the segmented electrode comprises an opposed pair comprising the first member and the second member, the first member symmetrically opposed to the second member about the axis defined by the electron beam, the first member and the second member defining an opposed pair axis passing substantially through the center of the first member and the second member, wherein adjusting a voltage bias of the first member relative to a voltage bias of the second member alters a beam intensity profile along the opposed pair axis.

11. The assembly in accordance with claim 10 , wherein the segmented electrode comprises a plurality of opposed pairs, the plurality of opposed pairs defining a substantially continuous geometric shape disposed about the axis defined by the electron beam and defining a plane substantially perpendicular to the electron beam.

Assignees

• Gen Electric

Inventors

• Frontera Mark Alan
• Zavodszky Peter Andras

Classifications

• A61B6/032

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