Experimental demonstration of the third cyclotron harmonic excitation in technological gyrotron with delayed selective feedback

Abstract

The excitation and effective selection of modes at high harmonics of the cyclotron frequency are experimentally demonstrated using a delayed feedback into the gyrotron. The operation at the third cyclotron harmonic at the frequency of 40.5 GHz with the output power of 3 kW and efficiency 8% is observed in a continuous wave gyrotron with an oil-cooled magnet with a field of 0.5 T in the interaction space.