# US 5,327,094 A · Jitter suppression in crossed-field amplifier by use of field emitter > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 5,327,094 A - Document ID: US5327094A - Status: Granted - Kind: A - Application number: 07/989,090 - Filed: 1992-12-11 - Granted: 1994-07-05 - Earliest claimed: 1992-12-11 - Assignees: Litton Systems, Inc. - Inventors: J. Rodney M. Vaughan; Kenneth F. Ramacher; Edward M. Doyle - Web page: https://patentgrep.com/patent/US5327094A ## CPC - H01J 23/04: Cathodes - H01J 23/06: Electron or ion guns - H01J: ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS (spark-gaps H01T; electric arc lamps H05B31/00; particle accelerators H05H) ## Abstract 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. ## Claims ### Claim 1 In a crossed-field amplifier having an anode and a cathode creating an electric field across a magnetic field in an interaction area, the improvement comprising: field emitter means connected to said cathode for providing priming electrons in said interaction area upon initiation of said amplifier to enable a fast start-up of said amplifier, wherein said priming electrons are emitted in response to said electric field. ### Claim 2 (depends on 1) The crossed-field amplifier as claimed in claim 1, wherein the field emitter means comprises a semiconductor base having a plurality of fibers extending therefrom, the fibers providing points for emission of electrons in response to said electric field. ### Claim 3 (depends on 1) The cross field amplifier as claimed in claim 1, additionally comprising: a slot provided in an outer surface of said cathode, said field emitter means being disposed within said slot. ### Claim 4 (depends on 3) The crossed-field amplifier as claimed in claim 3, wherein said slot is disposed adjacent to an RF input port of said amplifier. ### Claim 5 (depends on 2) The crossed-field amplifier as claimed in claim 2, wherein the fibers have a thin film of gold deposited thereon to prevent oxidation. ### Claim 6 (depends on 2) The crossed-field amplifier as claimed in claim 2, wherein the fibers are formed from tantalum disilicide (TaSi.sub.2). ### Claim 7 (depends on 2) The crossed-field amplifier as claimed in claim 2, wherein the semiconductor base is formed from silicon (Si). ### Claim 8 In a crossed-field amplifier having an anode and a cathode creating an electric field across a magnetic field in an interaction area, the improvement comprising: thermionic emitting means displaced from said cathode providing priming electrons in said interaction area upon initiation of said amplifier to enable a fast start-up of said amplifier, said thermionic emitting means being disposed in a space provided between adjacent anode vanes of said amplifier. ### Claim 9 (depends on 8) The crossed-field amplifier as claimed in claim 8, wherein said thermionic emitting means comprises a filament. ### Claim 10 (depends on 8) The crossed-field amplifier as claimed in claim 8, wherein said thermionic emitting means further comprises a voltage source external to said amplifier. ### Claim 11 (depends on 9) The crossed-field amplifier as claimed in claim 9, wherein said filament is a straight wire. ### Claim 12 (depends on 9) The crossed-field amplifier as claimed in claim 9, wherein said filament is a helix of tungsten. ### Claim 13 (depends on 9) The crossed-field amplifier as claimed in claim 9, wherein said filament is coated with an electron emissive oxide. ### Claim 14 In a crossed-field amplifier having an anode and a cathode creating an electric field across a magnetic field in an interaction area, the improvement comprising: means for providing priming electrons to said cathode upon initiation of said amplifier to enable a fast start-up of said amplifier, wherein said priming electrons are emitted in response to said electric field. ### Claim 15 In a crossed-field amplifier having an anode and a cathode creating an electric field across a magnetic field in an interaction area, the improvement comprising: means for providing priming electrons to said cathode upon initiation of said amplifier to enable a fast start-up of said amplifier, wherein said means comprises a field emitter having a semiconductor base and a plurality of fibers extending therefrom, the fibers emitting electrons in response to said electric field. ### Claim 16 (depends on 15) The crossed-field amplifier as claimed in claim 15, wherein said fibers are formed from tantalum disilicide (TaSi.sub.2). ### Claim 17 (depends on 15) The crossed-field amplifier as claimed in claim 15, additionally comprising a slot provided in an outer surface of said cathode, said field emitter being disposed within said slot. ### Claim 18 In a cross-field amplifier having an anode and a cathode creating an electric field across a magnetic field in an interaction area, the improvement comprising: means for providing priming electrons to said cathode upon initiation of said amplifier to enable a fast start-up of said amplifier, wherein said means comprises a thermionic emitting filament displaced from said cathode, said filament adapted to be connected to an external voltage source and emitting electrons in response to said voltage source, said filament being disposed in a space between adjacent anode vanes of said amplifier. ### Claim 19 (depends on 18) The crossed-field amplifier as claimed in claim 18, wherein the filament is a tungsten wire. ### Claim 20 A crossed-field amplifier, comprising: a cathode structure having an emitting surface which emits secondary electrons upon impingement of priming electrons incident thereon; an anode structure surrounding said cathode and comprising a plurality of radially extending vanes; and means for providing said priming electrons to said cathode upon initiation of said amplifier to enable a first start-up of said amplifier, said priming electrons originating from a location separate from said emitting surface of said cathode, said means further comprising a field emitter disposed in a slot provided in said emitting surface, wherein said priming electrons are emitted in response to said electric field. ### Claim 21 (depends on 20) The crossed-field amplifier as claim in claim 20, wherein said field emitter further comprises a semiconductor base and a plurality of fibers extending therefrom, the fibers emitting said priming electrons. ### Claim 22 A crossed-field amplifier, comprising: a cathode structure having an emitting surface which emits secondary electrons upon impingement of priming electrons incident thereon; an anode structure surrounding said cathode and comprising a plurality of radially extending vanes; and means for providing said priming electrons to said cathode upon initiation of said amplifier to enable a fast start-up of said amplifier, said priming electrons originating from a location separate from said emitting surface of said cathode, wherein said means comprises a thermionic emitting filament disposed within said anode structure, said filament adapted to be connected to an external voltage source and emitting electrons in response to said voltage source. ### Claim 23 (depends on 22) The crossed-field amplifier as claimed in claim 22, wherein the filament is disposed in a space between adjacent ones of said anode vanes.