Carbon nanotube fiber cathode
AssigneeThe United States of America as represented by the Secretary of the Air Force
InventorsSteven B Fairchild, Benji Maruyama
Life of this patent
Estimating the term…
Abstract
Improved field emission cathodes comprise a fiber of highly aligned and densely packed single-wall carbon nanotubes, double-wall carbon nanotubes, multi-wall carbon nanotubes, grapheme nanoribbons, carbon nanofibers, and/or carbon planar nanostructures. The fiber cathodes provide superior current carrying capacity without degradation or adverse effects under high field strength testing. The fibers also can be configured as multi-fiber field emission cathodes, and the use of low work function coatings and different tip configurations further improves their performance.
Claims14
An improved field emission cathode for high energy applications comprising:
- a fiber of densely-packed carbon nanotubes that are highly aligned along a longitudinal axis of the fiber;
- a low work function coating that is applied to the fiber;
- and
- a tip that is formed at one end of the fiber,
- wherein the nanotubes have a density of about 50% to about 100%.
An improved cathode array comprising:
- a substrate;
- a plurality of cathodes formed on one surface of the substrate;
- and
- a coating of carbon nanotubes which covers a tip of each cathode,
- wherein nanostructures in the coating of carbon nanotubes are not aligned with a field direction of the plurality of cathodes.
Dependencies are inferred from the claim text.