Electron emitter source
AssigneesOregon Physics, LLC, Applied Physics Technologies, Inc.
InventorsPaul P. Tesch, Gerald G. Magera
Life of this patent
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Abstract
An electron emitter that consists of: a low work function material including Lanthanum hexaboride or Iridium Cerium that acts as an emitter, a cylinder base made of high work function material that has a cone shape where the low work function material is embedded in the high work function material but is exposed at end of the cone and the combined structure is heated and biased to a negative voltage relative to an anode, an anode electrode that has positive bias relative to the emitter, and a wehnelt electrode with an aperture where the cylindrical base protrudes through the wehnelt aperture so the end of the cone containing the emissive area is placed between the wehnelt and the anode.
Claims20
An electron emitter comprising:
- a wehnelt
- an anode spaced downstream from said wehnelt;
- a co-axial aperture formed through said wehnelt and said anode;
- and
- an emitter extending into said co-axial aperture so that a terminal surface of said emitter is positioned between said wehnelt and said anode, said emitter having a cylindrical base formed of a high work function material having a hole formed through said terminal surface and extending into a body of the cylindrical base, said emitter further including a structure formed of a low work function material embedded within said hole and having an exposed emissive area,
- wherein said emitter is heated and biased to a negative voltage relative to the anode.
An emitter structure comprising:
- a structural cylindrical body formed of a high work function material;
- the structural cylindrical body forming a truncated cone at one end having frustoconical surfaces terminating in a flat circular surface;
- a cylindrical aperture formed through the flat circular surface and into an interior of the structural cylindrical body;
- and
- an inner cylindrical body formed of a low work function material received within the cylindrical aperture and terminating in an emitting end adjacent the flat circular surface.
Dependencies are inferred from the claim text.