Broad-energy spectrum electron gun

Patent metadata

Field	Value
Publication number	US-11848174-B2
Application number	US-202117186835-A
Country	US
Kind code	B2
Filing date	Feb 26, 2021
Priority date	Feb 28, 2020
Publication date	Dec 19, 2023
Grant date	Dec 19, 2023

Abstract

Various embodiments of the present technology generally relate to devices and methods for generating and directing energetic electrons toward a target. More specifically, some embodiments relate to devices, systems, and methods for generating and directing energetic electrons based in the photoelectric effect and directing electric field-focused beams of the energetic electrons toward a target. Electron guns according to the present technology include one or more light sources to stimulate electron transmission, and a series of differentially charged stages to provide a hollow path allowing electrons generated by the photoelectric effect of the light irradiated on interior surfaces defining the path through the stages to travel to an exit of the electron gun. Each of the differentially charged stages have a different potential, thereby providing electrons having two or more different and tunable energy levels exiting as a beam from the electron gun.

First claim

What is claimed is:

1. A system comprising:
a series of stages, each stage of the series having a hollow central region including an interior surface; and
means for stimulating photoelectric emission of electrons from the interior surface,
wherein hollow regions of the plurality of stages provide a path allowing emitted electrons to travel to an exit, and
wherein each stage of the series of stages has a different potential.

2. The system of claim 1 , wherein the series of stages are arranged in an axially stacked configuration having: an open muzzle end, and a second end opposite the muzzle end, and wherein:
a first stage of the series of stages is configured to electrically couple to a first potential, the first stage positioned proximal to the second end; and
at least a second stage of the series of stages is configured to electrically couple to at least a second potential having a magnitude that is less than a magnitude of the first potential, the at least a second stage positioned proximal to the muzzle end.

3. The system of claim 1 , wherein adjacent stages of the series of stages are electrically coupled.

4. The system of claim 1 further comprising insulation positioned in spaces between adjacent stages of the series of stages.

5. The system of claim 1 , wherein the means for stimulating photoelectric emission includes at least one light source to facilitate irradiating, and thereby eliciting a photoelectric response from, interior surfaces of at least two stages of the series of stages.

6. The system of claim 1 , wherein the hollow central region is defined by circular or ovoid bore holes formed in each stage of the series of stages.

7. The system of claim 1 , wherein each stage of the series of stages is formed at least partially of a conductor.

8. The system of claim 1 further comprising at least one conductive grid that at least partially spans an interior cavity defined by the hollow central region at one or more locations therein.

9. A broad-energy electron gun, comprising:
a housing having: an open muzzle end, and a second end opposite the muzzle end;
a plurality of stages positioned inside the housing in an axially stacked configuration having a hollow cavity defined by interior surfaces of the plurality of stages, wherein:
a first stage of the plurality of stages is configured to electrically couple to a first potential and is positioned proximal to the second end; and
at least a second stage of the plurality of stages is configured to electrically couple to a second potential having a magnitude that is less than a magnitude of the first potential, and is positioned proximal to the muzzle end.

10. The broad-energy spectrum electron gun of claim 9 further comprising at least one light source positioned inside the housing and proximal to the first stage to facilitate irradiating, and thereby eliciting a photoelectric response from, the interior surfaces.

11. The broad-energy spectrum electron gun of claim 9 further comprising means for stimulating photoelectric emission of electrons from interior surfaces of at least two stages of the plurality of stages to facilitate irradiating, and thereby eliciting a photoelectric response from, the interior surfaces.

12. The broad-energy spectrum electron gun of claim 11 , wherein the means for stimulating photoelectric emission includes a plurality of light sources, or a plurality of electron sources, in at least two positions inside of, or proximal to, the housing to facilitate irradiating, and thereby eliciting a photoelectric response from, the interior surfaces.

13. The broad-energy spectrum electron gun of claim 12 further comprising: a pair of light sources, a pair of electron sources, or one light source and one electron source, respectively positioned proximal to at least two of the plurality of stages to facilitate irradiating, and thereby eliciting a photoelectric response from, the interior surfaces.

14. The broad-energy spectrum electron gun of claim 10 , wherein a circular or ovoid hole is bored through each of the plurality of stages to define the hollow cavity.

15. The broad-energy spectrum electron gun of claim 14 , wherein holes bored through each of the plurality of stages are equally sized.

16. The broad-energy spectrum electron gun of claim 14 , wherein at least one of the holes bored through each of the plurality of stages is sized differently as compared to at least one other hole.

17. The broad-energy spectrum electron gun of claim 9 , wherein adjacent stages of the plurality of stages are electrically coupled.

18. A method comprising:
inducing a first voltage on a first stage of a plurality of stages of an electron gun;
inducing at least a second voltage on at least a second stage of the plurality of stages,
wherein the first stage is positioned proximal to a second end of the electron gun opposite a muzzle end of the electron gun, and
wherein a magnitude of the first voltage is greater than a magnitude of the at least a second voltage; and

irradiating interior surfaces of the first stage and the at least a second stage, using a means for stimulating photoelectric emission of electrons from the interior surfaces,
wherein electrons emitted from the interior surfaces of the first stage and the at least a second stage have energy levels that are proportional to the magnitudes of the induced voltages on each of the first stage and the at least a second stage.

19. The method of claim 18 further comprising accelerating the emitted electrons toward the muzzle end through an interior cavity defined by the interior surfaces of the first stage and the at least a second stage arranged in an axially stacked configuration.

20. The method of claim 18 , wherein irradiating interior surfaces of the first stage and the at least a second stage comprises irradiating the interior surfaces with light at a frequency sufficient to elicit a photoelectric response from the interior surfaces.

21. The method of claim 18 , wherein inducing the first voltage and inducing the at least a second voltage comprise establishing a voltage gradient over the plurality of stages.

22. A broad-energy electron gun, comprising:
an elongate housing defining a hollow cavity having: an open muzzle end, and a second end opposite the muzzle end;
a plurality of conductive grids spaced apart axially within, and at least partially spanning at least two portions of, the hollow cavity of the housing, wherein:
a first conductive grid of the plurality of conductive grids is configured to electrically couple to a first potential and is positioned proximal to the second end; and
at least a second conductive grid of the plurality of conductive grids is configured to electrically couple to a second potential having a magnitude that is less than a magnitude of the first potential, and is positioned proximal to the muzzle end.

23. The broad-energy electron gun of claim 22 further comprising means for stimulating photoelectric emission of electrons from surfaces of at least two of the plurality of conductive grids to facilitate irradiating, and thereby eliciting a photoelectric response from, the at least two conductive grids.

Assignees

• Univ Colorado Regents

Inventors

• Wilson Kieran
• Bengtson Miles
• Schaub Hanspeter
• Turpen Dalton

Classifications

• H01J37/305 Primary

  for casting, melting, evaporating, or etching · CPC title

• H01J37/065

  Construction of guns or parts thereof (H01J37/067 - H01J37/077 take precedence) · CPC title

• H01J2237/006

  Details of gas supplies, e.g. in an ion source, to a beam line, to a specimen or to a workpiece, (H01J37/3244 takes precedence; environmental cells for electron microscopes H01J2237/2003; microscopes with environmental specimen chamber H01J2237/2608) · CPC title

• H01J37/073 Primary

  Electron guns using field emission, photo emission, or secondary emission electron sources · CPC title

• H01J2237/04735

  with electrostatic means · CPC title