Method of Providing the High Cyclotron Harmonic Operation Selectivity in a Gyrotron With a Spatially Developed Operating Mode

An electrodynamic method for suppressing low-frequency oscillations at the fundamental cyclotron resonance in a gyrotron at a high cyclotron harmonic is proposed and theoretically investigated. According to simulations, the use of this method in the terahertz gyrotron at the second cyclotron harmonic operating at the spatially developed mode TE63,15 can provide a multiple excess of the starting currents of the parasitic modes over the starting current of the desired oscillations.