X-ray tube including hybrid electron emission source

Patent metadata

Field	Value
Publication number	US-10147581-B2
Application number	US-201615233198-A
Country	US
Kind code	B2
Filing date	Aug 10, 2016
Priority date	Jan 26, 2016
Publication date	Dec 4, 2018
Grant date	Dec 4, 2018

Abstract

Disclosed is an x-ray tube including a hybrid electron emission source, which uses, as an electron emission source, a cathode including both a field electron emission source and a thermal electron emission source. An x-ray tube includes an electron emission source emitting an electron beam, and a target part including a target material that emits an x-ray as the emitted electron beam collides with the target part, wherein the electron emission source includes a thermal electron emission source and a field electron emission source, and emits the electron beam by selectively using at least one of the thermal electron emission source and the field electron emission source.

First claim

What is claimed is:

1. An x-ray tube comprising:
an electron emission source emitting an electron beam; and
a target part including a target material that emits an x-ray as the emitted electron beam collides with the target part,
wherein the electron emission source includes a thermal emission source and a field emission source, and emits the electron beam by selectively using at least one of the thermal emission source and the field emission source.

2. The x-ray tube of claim 1 , wherein the thermal emission source includes:
a cathode to which a coil-shape tungsten filament is connected;
a focusing cup surrounding the periphery of the cathode, the focusing cup focusing an electron beam emitted from the cathode; and
a getter provided in the focusing cup, the getter removing outgassing that occurs in the x-ray tube by adsorption of the outgassing.

3. The x-ray tube of claim 2 , wherein the field electron emission source includes:
a gate electrode forming an electric field; and
a cathode electrode including an emitter that emits electrons induced by the electric field.

4. The x-ray tube of claim 3 , wherein the target part includes an anode electrode including the target material.

5. The x-ray tube of claim 4 , wherein the field emission source is disposed to share the focusing cup and the getter with the thermal emission source.

6. The x-ray tube of claim 4 , wherein the field emission source is disposed in the focusing cup.

7. The x-ray tube of claim 6 , wherein the field emission source is disposed beside the thermal emission source.

8. The x-ray tube of claim 6 , wherein the field electron emission source is disposed beside the cathode of the thermal emission source in the focusing cup.

9. The x-ray tube of claim 6 , wherein the field emission source is disposed inside the focusing cup, and the thermal emission source is disposed outside the focusing cup.

10. The x-ray tube of claim 6 , wherein the cathode of the thermal emission source is disposed outside of the focusing cup, and the cathode of the thermal emission source is disposed between the field emission source and the target part.

11. The x-ray tube of claim 6 , wherein the field emission source is disposed between the thermal emission source and the target part.

12. The x-ray tube of claim 6 , wherein the field emission source is disposed between the cathode of the thermal emission source and the target part.

13. The x-ray tube of claim 6 , wherein the electron beam emitted from the thermal electron emission source collides with the target part and a cathode of the field emission source, thereby causing the outgassing that is removed by the getter.

14. The x-ray tube of claim 6 , wherein the gate electrode allows a current to flow in the emitter, thereby removing outgassing of the emitter.

15. The x-ray tube of claim 13 , wherein the outgassing is removed in a manufacturing process of the x-ray tube.

16. The x-ray tube of claim 6 , wherein the getter is activated before the x-ray tube is sealed, to remove the outgassing that occurs during driving of the x-ray tube.

Assignees

• Electronics & Telecommunications Res Inst

Inventors

• Kang Jun Tae
• Song Yoon-Ho
• Kim Jae-Woo
• Jeong Jin-Woo

Classifications

• H01J2229/94

  Means for obtaining or maintaining the desired pressure within the tube · CPC title

• H01J29/46

  Arrangements of electrodes and associated parts for generating or controlling the ray or beam, e.g. electron-optical arrangement {(transit time tubes H01J23/00, H01J25/00; X-ray tubes H01J35/00; beam tubes for examining ions, e.g. electron or ion microscopes, or processing of objects or materials, e.g. electron or ion beam tubes H01J37/04; electron multipliers H01J43/04; handling of radiation or particles, e.g. focusing, deviating, not otherwise provided for G21K1/00)} · CPC title

• H01J35/06

  Cathodes · CPC title

• H01J2229/4827

  Electrodes formed on surface of common cylindrical support · CPC title

• H01J35/065

  Field emission, photo emission or secondary emission cathodes · CPC title