Relativistic quasi-optical Cerenkov oscillator with Wood anomalies

An analysis is presented of the interaction of the electron beam with electromagnetic fields in a relativistic quasi-optical Cerenkov oscillator. The Doppler harmonics of the signal are isolated at angles at which anomalous intensity maxima (i.e., Wood anomalies) occur on the radiation pattern of the periodic structure. The device can be considered a section of a circular superdimensional waveguide on the inner surface of which a periodic structure in the form of half-rings is deposited. Feedback in the oscillator is achieved by means of two conical mirrors. A power of 20 MW at a wavelength of 5 mm for pulse durations of 100 ns was obtained in experiments on a high-current electron injector.