Sectioned Gyro-BWO and Gyro-TWT with Zigzag Quasi-optical Systems: 2D Theory and Results

We present results of simplified 2D theories of two versions of the zigzag-type cyclotron resonance masers based on the use of microwave systems in the form of a quasi-optical transmission line providing transport of the Gaussian wave beam along a zigzag path. A simple spatio-temporal theory of the zigzag gyro-BWO predicts the following effects: the piecewise dependence of the generation frequency on the magnetic field, switching from the stationary single-frequency generation regimes to self-modulation regimes, as well as phenomenon of hysteresis with a smoothly changing the mismatch in continuous generation regime. The theory of a zigzag-type gyro-amplifier is developed for the case where the length of the system is limited by the condition of self-excitation of parasitic BWO-type waves. In this case, realization of a high-gain amplifier is possible if a system of isolated "clusters" consisting of several mirror sections is used.