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Title: Microwave pulse compression from a storage cavity with laser-induced switching

Abstract

A laser-induced switch and a multiple cavity configuration are disclosed for producing high power microwave pulses. The microwave pulses are well controlled in wavelength and timing, with a quick rise time and a variable shape and power of the pulse. In addition, a method of reducing pre-pulse leakage to a low level is disclosed. Microwave energy is directed coherently to one or more cavities that stores the energy in a single mode, represented as a standing wave pattern. In order to switch the stored microwave energy out of the main cavity and into the branch waveguide, a laser-actuated switch is provided for the cavity. The switch includes a laser, associated optics for delivering the beam into the main cavity, and a switching gas positioned at an antinode in the main cavity. When actuated, the switching gas ionizes, creating a plasma, which becomes reflective to the microwave energy, changing the resonance of the cavity, and as a result the stored microwave energy is abruptly switched out of the cavity. The laser may directly pre-ionize the switching gas, or it may pump an impurity in the switching gas to an energy level which switches when a pre-selected cavity field is attained. Timingmore » of switching the cavities is controlled by varying the pathlength of the actuating laser beam. For example, the pathlengths may be adjusted to output a single pulse of high power, or a series of quick lower power pulses.

Inventors:
 [1]
  1. Menlo Park, CA
Issue Date:
Research Org.:
Lawrence Livermore National Laboratory (LLNL), Livermore, CA (United States)
OSTI Identifier:
868469
Patent Number(s):
5148129
Assignee:
United States of America as represented by United States (Washington, DC)
Patent Classifications (CPCs):
H - ELECTRICITY H03 - BASIC ELECTRONIC CIRCUITRY H03K - PULSE TECHNIQUE
DOE Contract Number:  
W-7405-ENG-48
Resource Type:
Patent
Country of Publication:
United States
Language:
English
Subject:
microwave; pulse; compression; storage; cavity; laser-induced; switching; switch; multiple; configuration; disclosed; producing; power; pulses; controlled; wavelength; timing; quick; rise; time; variable; shape; addition; method; reducing; pre-pulse; leakage; level; energy; directed; coherently; cavities; stores; single; mode; represented; standing; wave; pattern; stored; main; branch; waveguide; laser-actuated; provided; laser; associated; optics; delivering; beam; gas; positioned; antinode; actuated; ionizes; creating; plasma; reflective; changing; resonance; result; abruptly; switched; directly; pre-ionize; pump; impurity; switches; pre-selected; field; attained; varying; pathlength; actuating; example; pathlengths; adjusted; output; series; power pulse; cavity configuration; pulse compression; energy level; microwave energy; laser beam; single mode; standing wave; single pulse; wave energy; rise time; power microwave; microwave pulses; microwave pulse; multiple cavity; wave pattern; wave pulse; power pulses; /333/315/327/

Citation Formats

Bolton, Paul R. Microwave pulse compression from a storage cavity with laser-induced switching. United States: N. p., 1992. Web.
Bolton, Paul R. Microwave pulse compression from a storage cavity with laser-induced switching. United States.
Bolton, Paul R. Wed . "Microwave pulse compression from a storage cavity with laser-induced switching". United States. https://www.osti.gov/servlets/purl/868469.
@article{osti_868469,
title = {Microwave pulse compression from a storage cavity with laser-induced switching},
author = {Bolton, Paul R},
abstractNote = {A laser-induced switch and a multiple cavity configuration are disclosed for producing high power microwave pulses. The microwave pulses are well controlled in wavelength and timing, with a quick rise time and a variable shape and power of the pulse. In addition, a method of reducing pre-pulse leakage to a low level is disclosed. Microwave energy is directed coherently to one or more cavities that stores the energy in a single mode, represented as a standing wave pattern. In order to switch the stored microwave energy out of the main cavity and into the branch waveguide, a laser-actuated switch is provided for the cavity. The switch includes a laser, associated optics for delivering the beam into the main cavity, and a switching gas positioned at an antinode in the main cavity. When actuated, the switching gas ionizes, creating a plasma, which becomes reflective to the microwave energy, changing the resonance of the cavity, and as a result the stored microwave energy is abruptly switched out of the cavity. The laser may directly pre-ionize the switching gas, or it may pump an impurity in the switching gas to an energy level which switches when a pre-selected cavity field is attained. Timing of switching the cavities is controlled by varying the pathlength of the actuating laser beam. For example, the pathlengths may be adjusted to output a single pulse of high power, or a series of quick lower power pulses.},
doi = {},
journal = {},
number = ,
volume = ,
place = {United States},
year = {Wed Jan 01 00:00:00 EST 1992},
month = {Wed Jan 01 00:00:00 EST 1992}
}

Works referenced in this record:

Prepulse suppression in microwave pulse‐compression cavities
journal, October 1986


Operation of a double cavity, microwave pulse compression system with phase controlled output
conference, January 1989


Laser triggering of a 500‐kV gas‐filled switch: A parametric study
journal, September 1984