Highly efficient operation of space harmonic peniotron at cyclotron high harmonics

The paper describes the oscillation characteristics of cyclotron high-harmonic peniotrons based on space harmonic interactions in magnetron waveguide resonators. The experimental results showed extremely high electronic efficiencies of 75% for the cyclotron third harmonic and 6% for the tenth harmonic at 30 and 100 GHz, respectively. It was proven that almost all of the rotational energy of the beam is transferred to that of an electromagnetic wave and the efficiency of 75% at the cyclotron third harmonic corresponds to the effective efficiency of 92% by the energy recovery of the spent electrons at the depressed potential collector.