Method of designing X-ray tube having planar emitter with tunable emission characteristics

Patent metadata

Field	Value
Publication number	US-10269529-B2
Application number	US-201715601728-A
Country	US
Kind code	B2
Filing date	May 22, 2017
Priority date	Oct 29, 2013
Publication date	Apr 23, 2019
Grant date	Apr 23, 2019

Abstract

A method of designing an electron emitter can include: determining a desired cross-sectional profile of an electron emission from an electron emitter and inputting parameters of the electron emitter into a computer; determining a desired temperature profile for the electron emitter that emits the desired cross-sectional profile; and determining desired emitter dimensions for a defined electrical current through the electron emitter that produces the desired temperature profile with the computer based on the input parameters of the electron emitter. The emitter dimensions can include: each rung width dimension; each first gap segment dimension; each second gap segment dimension; and each web dimension. The emitter can include: a plurality of elongate rungs connected together in a planar pattern; a plurality of corners; a first gap between adjacent non-connected elongate rungs; a second gap between adjacent non-connected elongate rungs; and one or more cutouts between a corner apex and corner nadir.

First claim

The invention claimed is:

1. A method of designing and manufacturing an electron emitter, the method comprising: determining a desired cross-sectional profile of an electron emission from an electron emitter and inputting parameters of the electron emitter having an emitter profile into a computer, the electron emitter comprising: a plurality of elongate rungs connected together end to end at corners, each corner having a corner apex and an opposite corner nadir, each elongate rung having a rung width dimension; a first gap between adjacent non-connected elongate rungs from the first emitter end to a middle rung, the first gap including a plurality of first gap segments each having a first gap segment width; a second gap between adjacent non-connected elongate rungs from the second emitter end to the middle rung, the second gap including a plurality of second gap segments each having a second gap segment width; and one or more body portions of each corner between the corner apex and corner nadir together define a web dimension for each corner; determining a desired temperature profile for the electron emitter that emits the desired cross-sectional profile of the electron emission; determining desired emitter dimensions of the emitter profile of the electron emitter for a defined electrical current through the electron emitter that produces the desired temperature profile with the computer based on the input parameters of the electron emitter in order to design the electron emitter having the emitter profile with the emitter dimensions, the emitter dimensions including: each rung width dimension; each first gap segment dimension;
each second gap segment dimension; and each web dimension;
and manufacturing a physical electron emitter having the emitter profile with the desired emitter dimensions.

2. The method of claim 1 , further comprising:
inputting an emitter pattern of the electron emitter into the computer, the emitter pattern including the emitter dimensions;
simulating the temperature profile of the emitter pattern on the computer for the defined current; and
determining whether the emitter pattern has the desired temperature profile for the defined electrical current.

3. The method of claim 2 , further comprising:
(a) changing one or more of the emitter dimensions in the computer to obtain an iterative emitter pattern having iterative emitter dimensions; and
(b) simulating the temperature profile of the iterative emitter pattern on the computer for the defined current; and
(c) determining whether the iterative emitter pattern has the desired temperature profile for the defined electrical current,
if not, then repeating (a) through (c).

4. The method of claim 1 , further comprising:
setting the web rung dimensions to correspond with an emitter pattern; and
varying the web dimensions to obtain the desired temperature profile.

5. The method of claim 1 , further comprising:
setting the web rung dimensions to correspond with an emitter pattern;
varying the web dimensions to obtain a first temperature profile that is different from the desired temperature profile; and
varying the rung width dimensions after varying the web dimensions to obtain the desired temperature profile.

6. The method of claim 1 , further comprising:
setting emitter dimensions for each rung width dimension, each first gap segment dimension, and each second gap segment dimension; and
varying each web dimension to obtain the desired temperature profile.

7. The method of claim 2 , further comprising:
obtaining a simulated temperature profile with the computer that corresponds to the desired temperature profile;
manufacturing a physical electron emitter having the emitter pattern that produced the simulated temperature profile;
testing the physical electron emitter with a defined electrical current; and
measuring the temperature profile of the physical electron emitter.

8. The method of claim 7 , further comprising:
when the temperature profile of the physical electron emitter matches the desired temperature profile, the physical electron emitter is implemented in an X-ray tube; or
when the temperature profile of the physical electron emitter does not match the desired temperature profile, the method further comprises:
(a) changing one or more of the emitter dimensions to obtain an iterative emitter pattern having iterative emitter dimensions; and
(b) simulating the temperature profile of the iterative emitter pattern on the computer for the defined current; and
(c) determining whether the iterative emitter pattern has the desired temperature profile for the defined electrical current,
if not, then repeating (a) through (c).

9. The method of claim 1 , further comprising:
obtaining a plurality of temperature points of the desired temperature profile;
simulating the temperature profile of the emitter pattern on the computer for the defined current to obtain a plurality of simulated temperature points of the simulated temperature profile;
comparing the plurality of temperature points with the plurality of simulated temperature points; and
selecting the emitter pattern when the plurality of temperature points substantially match the plurality of simulated temperature points.

10. The method of claim 1 , comprising entering the desired temperature profile for the electron emitter into the computer.

11. The method of claim 1 , comprising selecting the desired temperature profile from a database having a repository of temperature profiles and corresponding electron emitter patterns.

12. The method of claim 1 , comprising:
selecting an initial temperature profile from a database having a repository of temperature profiles and corresponding electron emitter patterns;
varying parameters of the electron emitter pattern; and
performing an iteration of temperature profile to obtain the desired temperature profile.

13. The method 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.

14. The method of claim 1 , wherein the one or more cutouts extend from at least one of the first gap or second cap into one or more of the plurality of corners.

15. The method of claim 1 , wherein the one or more cutouts extend from the corner nadir toward the corner apex, or extend from the corner apex toward the corner nadir.

16. The method of claim 14 , comprising determining a dimension of the one or more cutouts.

17. The method of claim 16 , 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.

18. An electron emitter comprising:
a plurality of rungs connected together 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 rung is connected to another rung through at least one corner of the plurality of corners, each corner having a corner apex and an opposite corner nadir between the connected rungs of the plurality of rungs;
a first gap between adjacent non-connected rungs of the plurality of rungs, wherein the first gap extends from the first

Assignees

• Varex Imaging Corp

Inventors

• Canfield Bradley D
• Woodman Colton B

Classifications

• H01J35/305 Primary

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

• H01J35/30

  by deflection of the cathode ray · CPC title

• 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

• H01J35/14 Primary

  Arrangements for concentrating, focusing, or directing the cathode ray · CPC title