Efficiency improvement in relativistic devices with linear electron beams by combined interaction

Abstract

Possibilities of efficiency improvement in relativistic electron devices with initially linear electron beams by providing resonance condition for Cherenkov and cyclotron interactions simultaneously are studied theoretically and by computer simulation. The main difference from previous research is the investigation of dynamic cyclotron resonance. The dynamic cyclotron resonance occurs in strong nonlinear regimes when the electron beam is separated by electromagnetic field to groups of accelerated or decelerated particles. For strong nonlinear regimes of interaction we can select some groups of electrons that interact with electromagnetic field under the same Cherenkov resonance condition but under different cyclotron resonance conditions. It was shown that efficiency can be improved from usual value for Cherenkov interaction (25%-28%) up to 50% by choosing appropriate value of focusing magnetic field.