Litton Systems, Inc.

Kenneth F Ramacher

Edward M Doyle

Michael S Worthington

Chris L Wheeland

George K Farney

Joseph C Musheno

Carl R Crager

Frank A Zawada

J Rodney Vaughan

Scott A Kleinle

The present invention provides a double helix coupled vane forward wave crossed-field amplifier utilizing backwall cooling and vane channel cooling in the RF slow wave circuit. Backwall channel cooling is provided for the majority of the anode vanes. Additional cooling is provided exclusively for the output vanes via individual coolant carrying passages in each output vane. The coolant carrying passages are machined into each standard double helix coupled output vane to create a vane channel in the shape of a 'U'. A tube formed in a corresponding U-shape is inserted and brazed to the machined vane. The vane assembly is then attached to the anode body of which the backwall has holes formed to accept the tubes from each vane. Divided backwall coolant channels are brazed to the outside of the anode, thereby placing in fluid communication the coolant channels to the tubes. Accordingly, coolant is cycled from a first backwall channel, through the output vanes and through the majority of the circumference of the anode via a second backwall channel, and back into the first backwall channel through a conduit and the vanes of the anode are thus preferentially cooled.

Preferentially cooled forward wave crossed-field amplifier anode

A non-concentric matrix support for a crossed-field device is provided. The crossed-field device comprises a cathode, a plurality of anode vanes radially disposed around the cathode, and an interaction region defined between the cathode and innermost tips of the anode vanes. The cathode matrix support is concentrically coupled to the cathode, and has an axis of symmetry parallel to an associated axis of symmetry of the anode vanes, and offset from the axis of symmetry of the anode vanes by a predetermined amount. The non-concentric matrix support further comprises an end-hat disposed at both axial ends thereof with each respective one of the end-hats being uniformly spaced from the anode vanes. In an embodiment, the offset is approximately 0.008 inches.

Non-concentric support for crossed-field amplifier

A crossed-field amplifier (CFA) includes a cylindrical cathode having an emitting surface coaxially disposed within an annular anode structure. The cathode has at least one circumferential groove disposed in the emitting surface. The grooves are relatively deep in comparison with their width. The grooves provide a phase smoothing of the rotating electron cloud spokes operative during crossed-field interaction. CFA noise is reduced by removal of the out-of-phase electrons. Due to their deeply cycloiding paths, these out-of-phase electrons become trapped in the grooves within a region generally shielded from the electric field of the CFA.

Phase smoothing cathode for reduced noise crossed-field amplifier

A crossed-field amplifier is provided which has an anode and a cathode creating an electric field across a magnetic field formed in an interaction area. A field emitter is disposed within a slot formed on an outer surface of the cathode. The field emitter emits an electron current in response to the electric field to provide priming electrons for improving the start up time of the amplifier. The electron current produced by the field emitter has been shown to initiate secondary emissions of electrons from the cathode to reduce irregular start-up or 'jitter' typically experienced with the amplifier at low pulse repetition frequencies. In an alternative embodiment of the invention, a thermionic emitting filament is disposed in a space between adjacent anode vanes of the amplifier. The filament emits electrons in response to an external power source. A portion of the emitted electrons tend to impact the anode vanes, creating x-rays which impact the cathode surface to initiate secondary emissions of electrons.

Jitter suppression in crossed-field amplifier by use of field emitter

The present invention discloses a cross-field amplifier having an anode and cathode with a pair of permanent magnets which create a magnetic field perpendicular to an electric field created between the anode and cathode. An electric bias circuit is connected between the cathode and a power supply that normally supplies energy to an oxygen source within the amplifier. This bias circuit supplies a negative DC voltage to the cathode. After the amplifier is turned off, the DC bias holds electrons within the interaction area between the cathode and anode for supplying the electrons needed to quickly restart the amplifier.

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Montoursville, PA, United States of America

Kenneth F Ramacher