Interaction of electron beams with EM-waves in conditions of cherenkov and cyclotron resonances

The interaction of the relativistic electron beam with the electromagnetic wave, on condition that both Cherenkov and cyclotron synchronisms can present simultaneously, is theoretically investigated in linear and non-linear approximations. It´s assumed that the initial value of transverse electron velocity can be non-zero. It´s shown that for various values of beam and wave parameters, the cherenkov and cyclotron mechanisms can intensify or suppress each other. Therefore, the interaction efficiency can be reduced or increased due to mutual influence of this effects to each other.