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

USA as Represented by Secretary of the Navy

Brad Winston Hoff

David Michael French

Susan L Heidger

Donald A Shiffler

Ali Sayir

Wilkin W Tang

Sterling Ryan Beeson

Wilkin Wai-Hang Tang

Michael D Haworth

Peter Jerome Mardahl

Christina Chen

David H Simon

James A Schrock

John C Horwath

Systems, methods and apparatus related to a method for constructing a field emission device. The method includes providing a metal cathode substrate; shaping a carbon fiber fabric into a pattern, creating a patterned carbon fiber fabric; and brazing at least a portion of the patterned carbon fiber fabric to the metal cathode substrate.

Systems, methods and apparatus for fabricating and utilizing a cathode

An electrode is embedded in a piece of ceramic material having a population of conduction band electrons. Applying a voltage bias to the electrode causes electrons to flow towards or away from the electrode to form a positively charged sheath either a distance apart from or adjacent the electrode, depending the polarity of the bias. The electron flow also forms a negatively charged sheath lying opposite the positively charged sheath, and an electrically neutral region lying between the two sheaths. Electromagnetic radiation impinging the ceramic material heats the ceramic where the radiation is absorbed by the electron population. As the incident radiation is absorbed in proportion to the electron density, heating is increased in the negatively charged sheath, relative to the other parts of the ceramic material. The location of heating is controlled by controlling the magnitude and polarity of the voltage bias.

Apparatus and method to control electromagnetic heating of ceramic materials

A crossed field device for generating electromagnetic emissions includes an anode having a first slow-wave structure having a plurality of first vanes separated by cavities formed therebetween and a second slow-wave structure having a plurality of second vanes separated by cavities formed therebetween. At least one of the first vanes is laterally aligned with one of the second vanes. The first vanes are offset from the second vanes by an offset distance so that at least one of the first vanes is not laterally aligned with a second vane and at least one of the second vanes is not laterally aligned with a first vane. The device further includes a cathode disposed in a space located between first and second vanes. A magnetic element generates a magnetic field (B), which is oriented orthogonally to an electric field (E) formed by the anode and cathode to generate EM emissions.

Crossed field device

An apparatus, system, and method for performing electron beam modulation includes an input pulser to provide an electromagnetic pulse; a radio frequency (RF) filter to filter the electromagnetic pulse; a nonlinear transmission line to receive the electromagnetic pulse, and generate a backward wave RF oscillation of a predetermined frequency to travel in a direction opposite that of the electromagnetic pulse; and an electron beam generating device including an anode and a cathode, the electron beam generating device to receive a combined electromagnetic pulse from the RF filter and the backward wave RF oscillation from the nonlinear transmission line to cause excitation of a modulated voltage between the anode and cathode, and to cause the electron beam generating device to emit an electron beam that is modulated at the predetermined frequency of the backward wave RF oscillation.

Electron beam modulator based on a nonlinear transmission line

A coaxial amplifier having at least one electron beam is provided. The amplifier may include a conductive rod, a plurality of parallel discs on the rod, a cathode array for producing at least one electron beam. When a plurality of electron beams are formed they are arranged in an annular configuration around said rod and disks, and directed along said rod and coaxially thereof. A first waveguide may apply electromagnetic wave energy to one end of said disc and rod assembly to induce propagation of said energy along said assembly. A second waveguide may extract the amplified electromagnetic energy from the other end of the disc and rod assembly.

Coaxial amplifier device

An apparatus for modulating the density of an electron beam as it is emitted from a cathode, comprised of connecting a source of pulsed input power to the input end of a nonlinear transmission line and connecting the output end directly to the cathode of an electron beam diode by a direct electrical connection.

Nonlinear transmission line based electron beam density modulator

A dielectric-based nonlinear transmission line (NLTL) coupled to an adjacent waveguide. Energy in an input pulse to the nonlinear transmission line is concentrated into an electromagnetic shock or a series of soliton-like oscillations by the nonlinear properties of the NLTL. Energy from the electromagnetic shock or the soliton-like oscillations are transferred into the waveguide. A plate of the NLTL coupled to the waveguide can include an aperture or a series of apertures. Energy from the electromagnetic shock or the soliton-like oscillations can then be transferred into waveguide via an aperture or apertures in such a way that forward and/or backward guided electromagnetic waves are generated in the waveguide. The waveguide can contain at a nonlinear magnetic material, a dielectric material, a slow wave structure, or a metamaterial. The NLTL can include nonlinear dielectric elements such as a periodic array interspersed with linear dielectric elements.

Nonlinear transmission line extraction systems

A method to modulate the density of an electron beam as it is emitted from a cathode, the method comprised of connecting a source of pulsed input power to the input end of a nonlinear transmission line and connecting the output end directly to the cathode of an electron beam diode by a direct electrical connection.

Nonlinear transmission line modulated electron beam emission

A wide aperture permanent magnet structure which is useful in creating a highly uniform longitudinal or solenoidal magnetic field in the working region of the magnet and in which the aperture of the structure can be equal in cross-sectional area to the working region of the magnet. The geometry and magnetization direction of the constituent magnets are chosen to maximize the uniformity of the longitudinal or solenoidal magnetic field in the working region of the magnet while minimizing the overall volume and weight of the structure as well as eliminating the need for magnetic pole pieces made of iron or other high permeability materials. The invention can take the form of a cylindrical shell of permanent magnets to create a solenoidal magnetic field, or a parallel surface arrangement to create a longitudinal magnetic field.

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Albuquerque, NM, United States of America

Brad Winston Hoff