A Cherenkov cyclotron autoresonance maser

A CARM is an efficient source of high frequency microwaves based on the negative mass instability. The output is Doppler-upshifted beyond the gyrotron frequency by the free electron factor of 2γ². By loading the interaction tube with dielectric, the voltage requirements are substantially reduced. Despite the reduced voltage, a significant upshift can still occur, since the Cherenkov effect enhances the electron´s velocity by ε^1/2, the refractive index of the dielectric