X-ray tube having planar emitter with tunable emission characteristics

Patent metadata

Field	Value
Publication number	US-9659741-B2
Application number	US-201514660607-A
Country	US
Kind code	B2
Filing date	Mar 17, 2015
Priority date	Oct 29, 2013
Publication date	May 23, 2017
Grant date	May 23, 2017

Abstract

An electron emitter can include: a plurality of elongate rungs connected together end to end from a first emitter end to a second emitter end in a plane so as to form a planar pattern; a plurality of corners, wherein each elongate rung is connected to another elongate rung through a corner having a corner apex and an opposite corner nadir; a first gap between adjacent non-connected elongate rungs, wherein the first gap extends from the first emitter end to a middle rung; a second gap between adjacent non-connected elongate rungs, wherein the second gap extends from the second emitter end to the middle rung, wherein the first gap does not intersect the second gap; and one or more cutouts at one or more of the corners of the plurality of corners between the corner apex and corner nadir or at the corner nadir.

First claim

The invention claimed is:

1. An electron emitter comprising:
a plurality of elongate rungs connected together end to end from a first emitter end to a second emitter end in a plane so as to form a planar pattern;
a plurality of corners, wherein each elongate rung is connected to another elongate rung through a corner of the plurality of corners, each corner having a corner apex and an opposite corner nadir between the connected elongate rungs of the plurality of elongate rungs;
a first gap between adjacent non-connected elongate rungs of the plurality of elongate rungs, wherein the first gap extends from the first emitter end to a middle rung;
a second gap between adjacent non-connected elongate rungs of the plurality of elongate rungs, wherein the second gap extends from the second emitter end to the middle rung, wherein the first gap does not intersect the second gap; and
one or more cutouts at one or more of the corners of the plurality of corners between the corner apex and corner nadir or at the corner nadir.

2. The emitter of claim 1 , wherein one or more body portions of each corner between the corner apex and corner nadir, excluding the one or more cutouts, together define a web dimension, each elongate rung having a rung width dimension, wherein the web dimension is within 10% of the rung width dimensions of the connected elongate rungs at the corner.

3. The emitter of claim 1 , wherein from the first end to middle rung, the first gap has a plurality of first gap segments each having a gap segment width, each gap segment width having a dimension that maintains the first gap when the emitter is at a non-emitting temperature and at an electron emitting temperature, and wherein from the second end to middle rung, the second gap has a plurality of second gap segments each having a gap segment width, each gap segment width having a dimension that maintains the second gap when the emitter is at the non-emitting temperature and at the electron emitting temperature.

4. The emitter of claim 1 , wherein the first gap is either clockwise or counter clockwise from the first end to the middle rung, and the second gap is the other of clockwise or counter clockwise from the middle rung to the second end so as to be the opposite orientation of the first gap.

5. The emitter of claim 1 , wherein a first portion of the plurality of elongate rungs has a first rung width dimension and a second portion of the plurality of elongate rungs has a different second rung dimension.

6. The emitter of claim 3 , wherein two or more of the first gap segments have different gap segment width dimensions, and two or more of the second gap segments have different gap segment width dimensions.

7. The emitter of claim 1 , wherein first and second rungs from the first emitter end have a first rung width dimension, and other rungs from the second rung to the middle rung have at least one rung width dimension that is different from the first rung width dimension, and wherein ultimate and penultimate rungs from the second emitter end have the first rung width dimension, and other rungs from the penultimate rung to the middle rung have at least one rung width dimension different from the first rung width dimension.

8. The emitter of claim 1 , each elongate rung of the plurality of elongate rungs having a flat surface that together the flat surfaces form a planar emitting surface in the form of the planar pattern.

9. The emitter of claim 8 , comprising a first elongate leg coupled to a first elongate rung at the first end and a second elongate leg coupled to an ultimate elongate rung at the second end, the first elongate leg and second elongate leg being at an angle relative to the planar emitting surface.

10. A method of inhomogeneously emitting electrons from an electron emitter, the method comprising:
providing the electron emitter of claim 1 having a planar emitter surface formed by the plurality of elongate rungs; and
emitting an inhomogeneous electron beam from the planar emitter surface in a perpendicular direction.

11. A method of manufacturing an electron emitter, the method comprising:
obtaining a sheet of electron emitter material;
obtaining an electron emitter pattern; and
laser cutting the electron emitter pattern into the electron emitter material, the electron emitter pattern including:
a plurality of elongate rungs connected together end to end from a first emitter end to a second emitter end in a plane so as to form a planar pattern;
a plurality of corners, wherein each elongate rung is connected to another elongate rung through a corner of the plurality of corners, each corner having a corner apex and an opposite corner nadir between the connected elongate rungs of the plurality of elongate rungs;
a first gap between adjacent non-connected elongate rungs of the plurality of elongate rungs, wherein the first gap extends from the first emitter end to a middle rung;
a second gap between adjacent non-connected elongate rungs of the plurality of elongate rungs, wherein the second gap extends from the second emitter end to the middle rung, wherein the first gap does not intersect the second gap; and
one or more cutouts at one or more of the corners of the plurality of corners between the corner apex and corner nadir or at the corner nadir.

12. The method of claim 11 , further comprising:
determining that the electron emitter pattern produces a desired temperature profile for a defined electrical current.

Assignees

• Varian Med Sys Inc
• Varex Imaging Corp

Inventors

• Canfield Bradley D
• Woodman Colton B

Classifications

• H05G1/10

  Power supply arrangements for feeding the X-ray tube {(supply circuits with converters in general H02M; supply circuits for emitters and amplifiers H04B1/16 - H04B1/1623)} · CPC title

• H01J35/305 Primary

  by using a rotating X-ray tube in conjunction therewith · CPC title

• H01J35/30

  by deflection of the cathode ray · CPC title

• H05G1/52

  Target size or shape; Direction of electron beam, e.g. in tubes with one anode and more than one cathode · CPC title

• H01J35/06

  Cathodes · CPC title