Problems of cathode design and breakdown avoidance relevant to high-power broadband gas-plasma-filled microwave sources

The main aspects of the problem of high-power broad-band gas-plasma-filled microwave device designed as a sealed tube, including beam-plasma processes, gas-dynamic system, electron optical system and cathode ion protection, are discussed. A non-relativistic beam-plasma microwave amplifier has been created to operate at output power up to 20 kW, electron efficiency 30% and pass-band width up to 30%.