ISSN:
1089-7674
Source:
AIP Digital Archive
Topics:
Physics
Notes:
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 Cerenkov 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.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1063/1.870931
