United States of America As Represented by the Secretary of the Air Force

Other

Steven B Fairchild

William O'Neill

Benji Maruyama

Dmitri Tsentalovich

Genevieve Dion

Nathaniel Lockwood

Chelsea Amanatides

Daniel P Gortat

Martin R Sparkes

John J Boeckl

A field emission (FE) cathode for a vacuum electronic device (VED) includes a metallic substrate configured to be connected to one of an electrical power supply and an electrical ground, and at least one continuous carbon nanotube (CNT) fiber in tension around at least a portion of the metallic substrate. The substrate can be a cylinder, hoop, plate, stub etc. The at least one continuous CNT fiber can include a filament, yarn, braided yarn, film, fabric, or combination thereof. The at least one continuous CNT fiber is secured to the electrically conductive substrate by vacuum brazing or any other suitable means. Also, a continuous CNT fabric can be secured in either tension or compression to maintain a uniform height of the continuous CNT fabric.

Cathodes having carbon nanotube (CNT) fibers wound onto metallic substrates

An electrode comprising a conductive textile structure having an inner surface that is connected to one of an electrical power supply and an electrical ground; the conductive textile structure having an outer surface, the outer surface comprising a carbon nanotube (CNT) fiber fabric fixed thereon, the CNT fiber fabric having continuous CNT fiber on the outer surface, wherein the CNT fiber fabric comprises at least one of a CNT fiber, and is at least one of knitted, woven, sewn, and embroidered. The continuous CNT fiber may be a yarn, ribbon, or thread. The CNT fiber fabric includes at least one face having a looped or interlaced structure made from the continuous CNT fiber. The CNT fiber yarn, ribbon, or thread is knitted, woven, sewn, and/or embroidered so that at least one surface comprises a textile made with CNT fiber yarns, ribbons, or threads.

Carbon nanotube yarn cathode using textile manufacturing methods

A method for reducing outgassing from a metal surface comprises applying energy from an energy source to the metal surface sufficient to melt the metal surface; and allowing the metal surface to re-solidify, wherein the re-solidified metal surface comprises larger grains and fewer grain boundaries, reducing outgassing sites for a trapped gas. Applying energy from an energy source is performed in a raster scan pattern. Adjacent passes in the raster scan pattern overlap sufficiently to melt the entire metal surface. The energy source is a laser, such as a CW Yb fiber laser. A spot size and applied energy of the laser energy source applied to the metal surface is sufficient to melt the entire metal surface (appropriate for the absorption and reflection characteristics of the treated material). The application of energy from an energy source releases at least some of a gas trapped in the metal. The trapped gas is atomic hydrogen. The metal surface comprises an electrode of a high power system device. The metal surface is in one of a high-vacuum environment and a vacuum electronic device. The metal surface comprises at least one of steel, stainless steel, nickel, and copper.

Laser surface melting for outgassing reduction

A carbon nanotube fiber carpet structure includes a backing material; and a plurality looped carbon nanotube (CNT) fiber conductors fixed to the backing material extending outward from the backing material in an array. The CNT fiber conductor may include at least one of a CNT thread, a CNT fiber, a CNT film, and a CNT ribbon, and the CNT fiber conductor may include a first end and a second end, the first end fixed to the backing material, and the second end fixed to the backing material a predetermined distance from the first end in order to form a loop of the CNT fiber conductor extending away from a backing material surface. The CNT fiber conductor may be woven into the backing material to form a plurality of loops of the CNT fiber conductor extending away from a backing surface material, and the backing material may be a conductive material.

Carbon nanotube fiber carpet structure

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.

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Beavercreek, OH, United States of America

Steven B Fairchild