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Title: Field emission cathode gating for RF electron guns and planar focusing cathodes

Abstract

A novel method of gating electron emission from field-emitter cathodes for radio frequency (RF) electrode guns and a novel cathode that provides a focused electron beam without the need for magnetic fields or a curved cathode surface are provided. The phase and strength of a predefined harmonic field, such as the 3rd harmonic field, are adjusted relative to a fundamental field to cause a field emission cathode to emit electrons at predefined times for the generation of high-brightness electron beams. The emission time is gated responsive to the combined harmonic and fundamental fields and the response of the FE cathode to the combined fields. A planar focusing cathode includes a selected dielectric material, such as a ceramic material, to provide an electron beam emission surface. Metal surfaces are provided both radially around and behind the dielectric material to shape the electric fields that accelerate and guide the beam from the cathode surface.

Inventors:
;
Issue Date:
Research Org.:
Argonne National Lab. (ANL), Argonne, IL (United States)
Sponsoring Org.:
USDOE
OSTI Identifier:
1531826
Patent Number(s):
7394201
Application Number:
11/248,661
Assignee:
UChicago Argonne, LLC (Chicago, IL)
Patent Classifications (CPCs):
H - ELECTRICITY H01 - BASIC ELECTRIC ELEMENTS H01J - ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
DOE Contract Number:  
W-31-109-ENG-38
Resource Type:
Patent
Resource Relation:
Patent File Date: 2005-10-11
Country of Publication:
United States
Language:
English
Subject:
46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND TECHNOLOGY

Citation Formats

Lewellen, John W., and Noonan, John. Field emission cathode gating for RF electron guns and planar focusing cathodes. United States: N. p., 2008. Web.
Lewellen, John W., & Noonan, John. Field emission cathode gating for RF electron guns and planar focusing cathodes. United States.
Lewellen, John W., and Noonan, John. Tue . "Field emission cathode gating for RF electron guns and planar focusing cathodes". United States. https://www.osti.gov/servlets/purl/1531826.
@article{osti_1531826,
title = {Field emission cathode gating for RF electron guns and planar focusing cathodes},
author = {Lewellen, John W. and Noonan, John},
abstractNote = {A novel method of gating electron emission from field-emitter cathodes for radio frequency (RF) electrode guns and a novel cathode that provides a focused electron beam without the need for magnetic fields or a curved cathode surface are provided. The phase and strength of a predefined harmonic field, such as the 3rd harmonic field, are adjusted relative to a fundamental field to cause a field emission cathode to emit electrons at predefined times for the generation of high-brightness electron beams. The emission time is gated responsive to the combined harmonic and fundamental fields and the response of the FE cathode to the combined fields. A planar focusing cathode includes a selected dielectric material, such as a ceramic material, to provide an electron beam emission surface. Metal surfaces are provided both radially around and behind the dielectric material to shape the electric fields that accelerate and guide the beam from the cathode surface.},
doi = {},
journal = {},
number = ,
volume = ,
place = {United States},
year = {2008},
month = {7}
}

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Works referenced in this record:

Gigatron microwave amplifier
patent, July 1993


Variable energy highly efficient linear accelerator
patent, October 1978


High power, long focus electron source for beam processing
patent, July 2007