skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Method and split cavity oscillator/modulator to generate pulsed particle beams and electromagnetic fields

Abstract

A compact device called the split cavity modulator whose self-generated oscillating electromagnetic field converts a steady particle beam into a modulated particle beam. The particle beam experiences both signs of the oscillating electric field during the transit through the split cavity modulator. The modulated particle beam can then be used to generate microwaves at that frequency and through the use of extractors, high efficiency extraction of microwave power is enabled. The modulated beam and the microwave frequency can be varied by the placement of resistive wires at nodes of oscillation within the cavity. The short beam travel length through the cavity permit higher currents because both space charge and pinching limitations are reduced. The need for an applied magnetic field to control the beam has been eliminated.

Inventors:
 [1];  [1];  [1]
  1. (Albuquerque, NM)
Publication Date:
Research Org.:
AT & T CORP
OSTI Identifier:
868888
Patent Number(s):
US 5235248
Assignee:
United States of America as represented by United States (Washington, DC) SNL
DOE Contract Number:
AC04-76DP00789
Resource Type:
Patent
Country of Publication:
United States
Language:
English
Subject:
method; split; cavity; oscillator; modulator; generate; pulsed; particle; beams; electromagnetic; fields; compact; device; called; self-generated; oscillating; field; converts; steady; beam; modulated; experiences; signs; electric; transit; microwaves; frequency; extractors; efficiency; extraction; microwave; power; enabled; varied; placement; resistive; wires; nodes; oscillation; travel; length; permit; currents; space; charge; pinching; limitations; reduced; applied; magnetic; control; eliminated; microwave frequency; electromagnetic fields; electromagnetic field; particle beam; electric field; magnetic field; magnetic fields; microwave power; particle beams; applied magnetic; space charge; split cavity; pulsed particle; modulated beam; wave frequency; rate pulse; /315/327/331/

Citation Formats

Clark, M. Collins, Coleman, P. Dale, and Marder, Barry M.. Method and split cavity oscillator/modulator to generate pulsed particle beams and electromagnetic fields. United States: N. p., 1993. Web.
Clark, M. Collins, Coleman, P. Dale, & Marder, Barry M.. Method and split cavity oscillator/modulator to generate pulsed particle beams and electromagnetic fields. United States.
Clark, M. Collins, Coleman, P. Dale, and Marder, Barry M.. Fri . "Method and split cavity oscillator/modulator to generate pulsed particle beams and electromagnetic fields". United States. doi:. https://www.osti.gov/servlets/purl/868888.
@article{osti_868888,
title = {Method and split cavity oscillator/modulator to generate pulsed particle beams and electromagnetic fields},
author = {Clark, M. Collins and Coleman, P. Dale and Marder, Barry M.},
abstractNote = {A compact device called the split cavity modulator whose self-generated oscillating electromagnetic field converts a steady particle beam into a modulated particle beam. The particle beam experiences both signs of the oscillating electric field during the transit through the split cavity modulator. The modulated particle beam can then be used to generate microwaves at that frequency and through the use of extractors, high efficiency extraction of microwave power is enabled. The modulated beam and the microwave frequency can be varied by the placement of resistive wires at nodes of oscillation within the cavity. The short beam travel length through the cavity permit higher currents because both space charge and pinching limitations are reduced. The need for an applied magnetic field to control the beam has been eliminated.},
doi = {},
journal = {},
number = ,
volume = ,
place = {United States},
year = {Fri Jan 01 00:00:00 EST 1993},
month = {Fri Jan 01 00:00:00 EST 1993}
}

Patent:

Save / Share:
  • A compact device called the split cavity modulator whose self-generated oscillating electromagnetic field converts a steady particle beam into a modulated particle beam. The particle beam experiences both signs of the oscillating electric field during the transit through the split cavity modulator. The modulated particle beam can then be used to generate microwaves at that frequency and through the use of extractors, high efficiency extraction of microwave power is enabled. The modulated beam and the microwave frequency can be varied by the placement of resistive wires at nodes of oscillation within the cavity. The short beam travel length through themore » cavity permit higher currents because both space charge and pinching limitations are reduced. The need for an applied magnetic field to control the beam has been eliminated.« less
  • This invention consists of a compact device called the split cavity modulator whose self-generated oscillating electromagnetic field converts a steady particle beam into a modulated particle beam. The particle beam experiences both signs of the oscillating electric field during the transit through the split cavity modulator. The modulated particle beam can then be used to generate microwaves as that frequency and through a series of sequential extractors, high efficiency extraction of microwave power is enabled. The modulated beam and the microwave frequency can be varied by the placement of resistive wires at nodes of oscillation within the cavity. The shortmore » beam travel length through the cavity permit higher currents because both space charge and pinching limitations are reduced. The need for an applied magnetic field to control the beam has been eliminated.« less
  • This invention consists of a compact device called the split cavity modulator whose self-generated oscillating electromagnetic field converts a steady particle beam into a modulated particle beam. The particle beam experiences both signs of the oscillating electric field during the transit through the split cavity modulator. The modulated particle beam can then be used to generate microwaves as that frequency and through a series of sequential extractors, high efficiency extraction of microwave power is enabled. The modulated beam and the microwave frequency can be varied by the placement of resistive wires at nodes of oscillation within the cavity. The shortmore » beam travel length through the cavity permit higher currents because both space charge and pinching limitations are reduced. The need for an applied magnetic field to control the beam has been eliminated.« less
  • This paper describes a compact device, called a split-cavity oscillator, whose self-excited oscillating electromagnetic field converts a large-area steady electron beam into one that is highly density modulated. it does this in a short beam travel length, easing both space-charge and pinching limitations. Thus high currents are possible without requiring a magnetic guide field. Methods for converting the modulated output beam into high-power microwaves are discussed, as are ways to phase-lock several oscillators together. Analytic theory, numerical simulations, and experiments describing the device are presented.
  • The split-cavity oscillator (SCO) is a cavity resonator that can be used to produce a high degree of density modulation in an intense relativistic electron beam. The kinetic energy of electrons in the modulated beam can be converted into high-power microwaves. Aspects of the modulated beam that affect the process of converting beam power into microwave power are considered, and a technique is investigated for optimizing the conversion efficiency of a microwave tube based on the SCO. Using a combination of nonlinear theory, numerical simulation, and experiment, it is shown that the most efficient implementation of the SCO is asmore » the modulating component of a klystronlike tube, in which the modulated beam is drifted a relatively short distance to maximize the rf current, which optimizes the efficiency of power extraction.« less