Gyro-TWT and Gyro-BWO with a Microwave Circuit in the Form of Zigzag Quasi-optical Transmission Line

Gyrotron-type devices with a novel quasi-optical microwave system are discussed. The proposed circuit is in the form a mirror transmission line where the mirrors support propagation of a Gaussian wave beam along a zigzag path with vertical and inclined segments periodically placed along longitudinal z-axis. A static B-field and translational electron velocity are directed along z-axis, so the electron beam periodically intersects with the wave beam. The cyclotron resonance maser (CRM) instability and thus resonant beam-wave interaction occurs at the regions of perpendicular beam-wave intersections inside which an electromagnetic wave with the Bz-component similar to a gyrotron propagates across the e-beam yielding in the cyclotron phase bunching and energy exchange with minor criticality to the particle velocity spread. The 3D PIC simulations shows prospects of this “zigzag” CRM in realization of frequency tunable amplifiers and oscillators capable of high power and unique (octave frequency band) tuning in the short-millimeter wavelength range.