Quasi-anomalous Doppler effect in a periodic-waveguide cyclotron maser

The quasi-anomalous Doppler effect is proposed in this paper as a new operating regime for cyclotron-resonance masers (CRMs). It combines features of the known normal and anomalous Doppler effects. A linear analysis of the CRM interaction shows that the quasi-anomalous Doppler effect may occur with fast em waves in inductive (low-impedance) periodic waveguides, and that it may produce gain without an initial rotation of the electron beam. A practical scheme of a slotted-waveguide CRM operating in the high frequency passband is proposed for a future experiment.