Dynamics of a cyclotron autoresonance maser oscillator in a highly relativistic regime

The interaction dynamics for a cyclotron autoresonance maser oscillator is studied in its nonlinear saturation regime. In a highly relativistic limit of electron energy, such that the longitudinal beam velocity approaches to the speed of light, the dynamics has a sensitive dependence on the longitudinal phase velocity of the radiation field. We investigate the dynamic variations and their consequences on the saturation efficiency, in a range that the phase velocity is slightly greater than the free space value. It is observed that, for an appropriate value of the phase velocity, the potential bucket in the phase space expands to a maximal area. Consequential enhancement of the nonlinear saturation efficiency is estimated