Studies of a Gyrotron with the Echelette Cavity

We describe a gyrotron which is operated at the first gyrofrequency harmonic and has an echelette cavity with the sinusoidal corrugation profile. A method for calculating the parameters of the echelette cavity and the gyrotron is described. The results of measuring the electrodynamic characteristics of the echelette cavity and studying experimentally the gyrotron with such a cavity are presented. It is shown that the gyrotron has a rarefied spectrum of eigenoscillations and the efficiency at the level of typical megawatt-power gyrotrons, and is characterized by a significantly lower degree of cavity wall heating. The structure of radiation from the gyrotron with the echelette cavity and the possibility of transmitting this radiation by means of a mirror waveguide, are discussed.