Apparatus for generating x-ray radiation in an external magnetic field

Patent metadata

Field	Value
Publication number	US-9960003-B2
Application number	US-201615544854-A
Country	US
Kind code	B2
Filing date	Jan 18, 2016
Priority date	Jan 27, 2015
Publication date	May 1, 2018
Grant date	May 1, 2018

Abstract

An apparatus is provided for generating X-ray radiation in an outer magnetic field, which may be generated by a magnetic field device. The apparatus includes a cathode configured to generate an electron beam and an anode configured to retard the electrons of the electron beam and generate an X-ray beam. The apparatus further includes a device configured to generate an electric field orientated from the anode in the direction of the cathode and substantially collinear to the outer magnetic field, wherein the cathode, as an electron emitter, includes a cold cathode that passively provides free electrons by field emission.

First claim

The invention claimed is:

1. An apparatus for generating x-ray radiation in an external magnetic field generable by a magnetic field device, the apparatus comprising:
a cathode configured to generate an electron beam;
an anode configured to decelerate the electrons of the electron beam and generate an x-ray beam; and
a device configured to generate an electric field directed from the anode in a direction of the cathode, wherein the electric field is substantially collinear with the external magnetic field;
wherein the cathode comprises an electron emitter having a cold cathode that passively provides free electrons by field emission.

2. The apparatus of claim 1 , wherein the electron emitter has a linear embodiment.

3. The apparatus of claim 1 , wherein the electron emitter has a convex surface in a cross section in relation to an axial direction of extent, wherein the convex surface extends exclusively in a direction of the anode.

4. The apparatus of claim 1 , wherein the electron emitter has a form of a semi-cylinder in a cross section in relation to an axial direction of extent.

5. The apparatus of claim 1 , wherein the cathode comprises a substrate on which the electron emitter is arranged.

6. The apparatus of claim 3 , wherein the axial direction of extent extends parallel or at an angle to a first direction extending perpendicular to a third direction of the electric field and a second direction transverse to the electric field, wherein an impact area of the anode lies in a plane that extends parallel to the second direction and at an acute angle to the first direction.

7. The apparatus of claim 1 , wherein the electron emitter comprises carbon.

8. The apparatus of claim 1 , wherein the electron emitter has an irregular surface.

9. The apparatus of claim 1 , further comprising:
a voltage source configured to provide a voltage between the cathode and the anode.

10. The apparatus of claim 1 , further comprising:
a further electrode arranged between the anode and the cathode; and
a voltage source configured to provide a voltage between the cathode and the further electrode.

11. The apparatus of claim 2 , wherein the electron emitter has a convex surface in a cross section in relation to an axial direction of extent, wherein the convex surface extends exclusively in a direction of the anode.

12. The apparatus of claim 11 , wherein the cathode comprises a substrate on which the electron emitter is arranged.

13. The apparatus of claim 12 , wherein the axial direction of extent extends parallel or at an angle to a first direction extending perpendicular to a third direction of the electric field and a second direction transverse to the electric field, wherein an impact area of the anode lies in a plane that extends parallel to the second direction and at an acute angle to the first direction.

14. The apparatus of claim 11 , wherein the axial direction of extent extends parallel or at an angle to a first direction extending perpendicular to a third direction of the electric field and a second direction transverse to the electric field, wherein an impact area of the anode lies in a plane that extends parallel to the second direction and at an acute angle to the first direction.

15. The apparatus of claim 2 , wherein the electron emitter has a form of a semi-cylinder in a cross section in relation to an axial direction of extent.

16. The apparatus of claim 15 , wherein the cathode comprises a substrate on which the electron emitter is arranged.

17. The apparatus of claim 16 , wherein the axial direction of extent extends parallel or at an angle to a first direction extending perpendicular to a third direction of the electric field and a second direction transverse to the electric field, wherein an impact area of the anode lies in a plane that extends parallel to the second direction and at an acute angle to the first direction.

18. The apparatus of claim 4 , wherein the axial direction of extent extends parallel or at an angle to a first direction extending perpendicular to a third direction of the electric field and a second direction transverse to the electric field, wherein an impact area of the anode lies in a plane that extends parallel to the second direction and at an acute angle to the first direction.

19. The apparatus of claim 4 , wherein the cathode comprises a substrate on which the electron emitter is arranged.

Assignees

• Siemens Ag

Inventors

• Geisler Andreas
• Goβmann Svetlana
• Heid Oliver

Classifications

• H01J31/08

  having a screen on or from which an image or pattern is formed, picked up, converted, or stored · CPC title

• H01J1/304 Primary

  Field-emissive cathodes · CPC title

• H01J9/025

  of field emission cathodes · CPC title

• H01J35/065 Primary

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

• H01J35/10

  Rotary anodes; Arrangements for rotating anodes; Cooling rotary anodes · CPC title