Multi-GW relativistic backward wave oscillator with TM02 operating mode

First version of relativistic BWO with TM₀₂ operating mode has been tested also in [1]. The cyclotron-resonance mode selection was used. In this case, because of requirement to the defined values of magnetic field and e-beam radius, the efficiency of oscillator was not very high (approximately 10%). Now, the different electrodynamic codes are available to optimize the geometry of Slow Wave Structure (SWS) and reflector for TM₀₂ mode with small re-emission to TM₀₁. Then other techniques of mode selection such as the e-beam pre-modulation near the reflector [2], sectioning of SWS and diffractive losses at the coaxial magnetically-insolated diode can be used. So, refusing the cyclotron-type discrimination of TM₀₁ mode, we studied approaches of mode selection with higher magnetic field to increase the BWO efficiency, including the idea of self-modulated e-beam emission [3].