Phase Locking of a Gyrotron with Low-Frequency Voltage and Current Fluctuations by an External Monochromatic Signal

We show that during phase locking of the oscillations of a megawatt-level gyrotron by a relatively weak external monochromatic signal, the phase and frequency modulation of the gyrotron radiation due to the low-frequency fluctuations of the accelerating voltage and current decreases severalfold compared to the autonomous regime. The calculations were performed using the example of two megawatt-level gyrotrons, namely, a gyrotron developed at the Institute of Applied Physics of the Russian Academy of Sciences and operated at the TE28,12 mode with a frequency of 170 GHz [1] and a gyrotron with twice as high frequency and operation-mode indices (345 GHz and TE56,24), whose ability to generate a megawatt power in the case of frequency and phase locking by an external signal is shown theoretically [2].