Wave dispersion and growth analysis of low-voltage grating [hacek C]erenkov amplifiers

Journal Article · Sat Jan 01 04:00:00 EST 1994 · Physics of Plasmas; (United States)

DOI:https://doi.org/10.1063/1.870931· OSTI ID:6686272

Joe, J; Scharer, J; Booske, J; McVey, B ^[1]

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1. Department of Electrical and Computer Engineering, University of Wisconsin, Madison, Wisconsin 53706 (United States)

A theoretical and computational investigation of an electron sheet beam propagating over a grating structure in a rectangular waveguide is carried out. Regimes for low voltage [hacek C]erenkov amplifier operation are sought by examining the complex dispersion relation for hybrid waveguide modes in the slow wave structure, which includes sheet beam space-charge effects. A computer code is developed to examine the complex dispersion relation and growth rates for the wave modes. Mode competition is considered and methods to reduce it are presented. Briggs' criteria is utilized to examine absolute and convective wave growth for the forward wave, backward wave, and transition mode regimes of operation as a function of the beam, hybrid mode, and slow wave grating characteristics. An examination of the effects of beam spread on absolute and convective wave growth to determine regimes for amplifier operation is carried out. A modest Maxwellian beam spread is found to yield a regime of effective backward convective amplification, in addition to the purely convective growth characteristics for the forward wave mode case.

• OSTI ID: 6686272
• Journal Information: Physics of Plasmas; (United States), Journal Name: Physics of Plasmas; (United States) Vol. 1:1; ISSN PHPAEN; ISSN 1070-664X
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
700340* -- Plasma Waves
Oscillations
& Instabilities-- (1992-)
AMPLIFIERS
BEAMS
BRIGGS CRITERION
CHERENKOV RADIATION
COMPUTER CODES
DISPERSION RELATIONS
ELECTROMAGNETIC RADIATION
ELECTRON BEAMS
ELECTRON TUBES
ELECTRONIC EQUIPMENT
EQUIPMENT
GRATINGS
INSTABILITY GROWTH RATES
LEPTON BEAMS
PARTICLE BEAMS
RADIATIONS
SPACE CHARGE
WAVEGUIDES