Frequency stability in plasma relativistic microwave oscillators

Some features in the operation of microwave oscillators based on the interaction of high-current relativistic electron beams with plasma are considered. The frequency of radiation generated by such oscillators depends of the plasma density, which can vary both during a single microwave pulse and from one pulse to another. The magnitude of these variations can reach several percent. The dependence of the oscillator frequency on the plasma density has been analyzed and the possibility of ensuring stable generation has been studied in numerical experiments. It is established that microwave pulses can be generated with a frequency scatter, which does not exceed the natural spectral bandwidth determined by the pulse duration. The results of calculations and numerical simulations are compared to the available experimental data.