ELECTROMAGNETIC-WAVE GENERATION IN A CYLINDRICAL RESONATOR BY ELECTRONS ORBITING IN A RADIAL ELECTROSTATIC-FIELD

The mechanisms leading to the generation of microwaves by electrons or biting in a radial electrostatic field produced by a positively charge d filament on the axis of a cylindrical resonator are investigated the oretically. The dispersion relations describing the interaction of the waves with the electrons are obtained. It is shown that the generatio n of electromagnetic fields is possible on account of both Cherenkov a nd plasma resonances. The frequencies and growth rates of waves under Cherenkov resonance conditions and also plasma resonance conditions in uniform and nonuniform electron layers are found. The advantages and disadvantages of different generation mechanisms are determined. (C) 1 998 American Institute of Physics. [S1063-7842(98)01508-6].