Study of gyrotron backward-wave oscillator with external reflections

Summary form only given. The gyrotron backward-wave oscillator (gyro-BWO) is highly sensitive to external reflections due to its non-resonant RF structure. The reflected power may result in serious output power variation, ragged frequency tuning, and non-stationary behavior in gyro-BWO. In the study, the system is treated as coupled linear-nonlinear oscillators and studied by a hybrid time-dependent code, in which reflection is self-consistently determined by the structure. The numerical results are compared with typically coupled linear-linear oscillators, and the comparisons show that the variation of the output power and the ragged frequency tuning are caused by the strong coupling between two oscillators when the resonant frequencies and quality factors of two oscillators are almost the same. The stability of the gyro-BWO with external reflection is examined and will be presented in the paper