Carbon nanotube coated anode

• US 6,645,628 B2
• Filed: 11/13/2001
• Issued: 11/11/2003
• Est. Priority Date: 11/13/2001
• Status: Expired due to Fees

• Current Assignee: United States Of America As Represented By The Secretary Of The Air Force
• Original Assignee: United States Of America As Represented By The Secretary Of The Air Force
• Inventors: Haworth, Michael D., Shiffler, Donald A. Jr.
• Primary Examiner(s): TURNER, ARCHENE A
• Application Number:
  US09/683,047
• Publication Number:
  US 20030091825A1
• Time in Patent Office: 728 Days
• Field of Search: 428/408, 428/469, 257/79
• US Class Current: 428/408
• CPC Class Codes: B82Y 10/00 Nanotechnology for information processing, storage or transmission, e.g. quantum computing or single electron logic
• CPC Class Codes: H01J 1/38 characterised by the material
• CPC Class Codes: H01J 23/027 Collectors
• CPC Class Codes: H01J 29/085 Anode plates, e.g. for screens of flat panel displays
• CPC Class Codes: H01J 9/02 Manufacture of electrodes or electrode systems
• CPC Class Codes: H01J 9/14 of non-emitting electrodes
• CPC Class Codes: Y10S 977/742 Carbon nanotubes, CNTs
• CPC Class Codes: Y10S 977/847 Surface modifications, e.g. functionalization, coating
• CPC Class Codes: Y10T 428/30 Self-sustaining carbon mass or layer with impregnant or other layer

Abstract

A vacuum tube having its anode/collector coated with carbon nanotube-based material in which five percent or more of the carbon nanotubes are aligned parallel to the anode/collector'"'"'s surface.

Claims

1. An anode assembly for reducing production of secondary electrons, comprising:

an anode;

a plurality of carbon nanotubes coating the anode;

each of the nanotubes having a longitudinal axis;

each of the nanotubes being comprised of sections, and each section lying proximate to a local surface of the anode; and

a plurality of sections having longitudinal axes lying parallel to their respective local surfaces.

2. An anode assembly as defined in claim 1 wherein the nanotubes are woven into a nanotube fabric.

3. An anode assembly as defined in claim 1 wherein the nanotubes are hollow.

4. An anode assembly as defined in claim 1 wherein the nanotubes are pyro-bonded to the anode.

5. An anode assembly as defined in claim 1 wherein:

each longitudinal axis has a length;

the longitudinal axis for each section has a section length;

the nanotubes have a collective longitudinal axis length equal to a sum of the lengths of the longitudinal axes; and

at least 5% of the collective longitudinal axis length is comprised of section lengths for sections having longitudinal axes lying parallel to their respective local surfaces.

6. An anode assembly as defined in claim 1 wherein:

each of the nanotubes has a transverse axis;

each of the nanotubes has a transverse electrical conductivity along the transverse axis and a longitudinal electrical conductivity along the longitudinal axis; and

the longitudinal electrical conductivity is greater than the transverse electrical conductivity, whereby

a majority of electrons being conducted by the nanotubes are conducted in parallel with the local surfaces.

7. An anode assembly as defined in claim 1 wherein the anode is comprised of a carbon film surrounding a metal substrate.

8. An anode assembly as defined in claim 1 wherein the anode is comprised of carbon.

9. An anode assembly defined in claim 1 wherein:

the anode includes an electron impact area; and

the nanotubes cover the electron impact area.

10. An anode assembly as defined in claim 1 wherein:

the anode includes a surface; and

the longitudinal axes are nonorthogonal to the surface.

11. An anode assembly as defined in claim 1 wherein the longitudinal axes of the sections are nonorthogonal to the respective local surfaces.

12. The felt material as defined in claim 11 wherein the fabric is a polymer.