Computer Simulation of Efficiency Enhancement Through Profiling Guiding Magnetic Field at Coaxial Gyro-BWO

The gyro-BWO is a UHF powerful oscillator for cm and mm band of wavelength in which relativistic electrons beam is used for coupling with a backward wave on normal Doppler effect. The first research of gyro-devices was published in 60th. Possible applications of gyro-devices UHF radiation are the followings: electron cyclotron resonance heating of plasma for controlled fusion, communication, spectroscopic researches, high-resolution radars etc. Investigations of gyro-BWO confirm that an essential limitation of the considered device is the small efficiency. One of possibilities for efficiency enhancing is to use profiling guiding magnetic field along an interaction region. We investigated dependence of efficiency increasing under using optimal profiling guiding magnetic field by special law. As a result of effective process bunch formation under special conditions most electrons can be confined in the energy-losing phase HF field. Efficiency enhancement takes place from initial value for homogenous guiding field to for profiling one.