We study locking of the oscillation frequency of the operating TE
28,12
mode by an external monochromatic signal in a multimode gyrotron operated at a frequency of 170 GHz in the switch-on regime ...close to the real one. Locking zones, i.e., regions of single-mode generation at the external-signal frequency are found on the “current—detuning” plane of parameters. It is shown that as the number of competing modes increases, the maximum achievable current decreases, and the locking zones contract at sufficiently high currents.
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 TE
28,12
mode with a frequency of 170 GHz 1 and a gyrotron with twice as high frequency and operation-mode indices (345 GHz and TE
56,24
), whose ability to generate a megawatt power in the case of frequency and phase locking by an external signal is shown theoretically 2.
We study the possibility to stabilize the gyrotron frequency under the influence of a wave reflected from a remote output window during the competition of the operating mode with two neighboring ...modes, which have frequencies equally spaced from the frequency of the operating mode. The window is assumed to reflect radiation at the frequency of the operating mode and be transparent for the neighboring modes. The influence of the shift of the reflector within the limits of several wavelengths on the frequency stabilization is considered. The fluctuations in the frequency and phase of the radiation, which are caused by low-frequency technical noises of the accelerating voltage of the electron beam, in a stand-alone gyrotron and a gyrotron with a reflection are compared. The calculations were performed for the megawatt gyrotron with a frequency of 170 GHz and the operating TE mode, which was developed at the Institute of Applied Physics of the Russian Academy of Sciences (IAP).
We study the oscillation regimes for the model of a gyrotron with a fixed Gaussian longitudinal field structure and three modes of an equidistant spectrum (an operation mode and two satellites ...symmetrically spaced by frequency) during autonomous operation and under the action of an external monochromatic signal. The two-parameter (dimensionless current and the cyclotronresonance mismatch for an operating mode) plane is partitioned into the regions corresponding to various regimes. It is shown that the presence of a maximum at the leading edge of the voltage pulse can lead to excitation of the parasitic modes in the process of the power-source switch-on and to quenching of oscillation of the operating mode. These undesirable effects can be suppressed by locking the operation-mode frequency by an external monochromatic signal, which provides oscillation at the operation mode.
We consider the influence of an external quasi-monochromatic signal on a multimode gyrotron in the case where the signal frequency is close to the frequency of the operating mode of the gyrotron. The ...influence of the mode competition on the generation regime at a harmonic frequency modulation is studied. The calculations were performed for a high-power 170 GHz gyrotron developed at the Institute of Applied Physics of the Russian Academy of Sciences (IAP RAS). Depending on the parameters of the gyrotron and the external signal, various generation regimes were determined, including locking of the operating-mode frequency when the radiation frequency is close to the frequency of the external signal, beats of the frequency and amplitude of the operating mode, and excitation of spurious modes.
We study frequency locking of the gyrotron operating mode by a monochromatic external signal under conditions of competition of several modes. The calculations were performed for a megawatt-power ...170-GHz gyrotron with the operating TE
28.12
mode. Mode interaction of both equidistant and nonequidistant spectra is considered. Frequency detuning of the modes is comparable to the cyclotron resonance bandwidth. Influence of the external-signal power on the boundaries of the frequency locking zones is studied. The possibility to achieve a high orbital efficiency and broadband frequency tuning in the frequency-locking regime is considered.
The radiation-frequency locking by an external signal is experimentally studied for a megawatt gyrotron. An external signal from a magnetron is applied to the operation space of the gyrotron at a ...frequency of 35 GHz via a synthesized two-mirror quasioptical converter developed at the Institute of Applied Physics of the Russian Academy of Sciences. The radiation spectra are measured for both the frequency locking regime and the frequency beats. The locking region is constructed on the plane of two parameters, namely, the external-signal power and frequency. The experimental and theoretical results are compared to show a good agreement.
The frequency capture of radiation by an external signal was experimentally studied for the first time for a megawatt-power gyrotron. An external signal from the magnetron at a frequency of 35 GHz ...entered the working space of the gyrotron through a synthesized two-mirror quasi-optical converter that allowed transforming the input signal into a working mode. This converter has been recently developed and implemented in the Institute of Applied Physics, Russian Academy of Sciences. The radiation spectra were experimentally obtained in modes of frequency capture and frequency beats. The dependence of the frequency capture bandwidth on the power of the external signal was found. Comparison of experimental results with the data of numerical modelling of gyrotron equations with an external signal showed their good agreement.
We have numerically studied capturing of the oscillation frequency and phase of the TE28.12 operating mode by an external monochromatic signal for a multimode gyrotron with a close to real regime of ...activation. It is shown that, even at a low external-signal power, in a wide range of the magnetic field and voltage, a highly efficient single-mode generating is set at the frequency of the external signal.
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