Relativistic generators with high average radiation power
Generators based on all mechanisms of stimulated emission of relativistic electron beams reached the gigawatt level of the peak radiation power in wavelength bands from decimeters to millimeters long ago. At the same time, sources used in such applications as accelerators with ultrafast particle acceleration, radars, etc. require that such generators should provide not only a peak power, but also a high average power of radiation, up to 105 W. This can be achieved by using accelerators, which operate at a high electron pulse repetition rate, and magnetic systems capable of ensuring sufficiently long magnetic pulses.
In many cases, the simplest and most adequate way of achieving a high average power is the use of relativistic BWOs with explosive-emission injectors of high-current electron beams. Such generators have high adaptivity and short durations of transient processes, and their electrodynamic systems are well compatible with high-current electron beams. In the centimeter-wave band, they ensure production of spatially coherent radiation with a peak power of more than 1 GW in pulses with durations of up to 20–30 ns.
In recent years, relativistic BWOs, which produce a gigawatt level of microwave power in nanosecond pulses and are capable of operating at a pulse repetition rate of up to 500 Hz, has reached a high level of engineering. IAP proposed a new variety of the magnetically insulated diode with a high-current explosive-emission edge cathode and a profiled anode (N. F. Kovalev), which allowed controlling the duration of microwave pulses, decreasing the switch-on time, and increasing the energy efficiency of the 3 cm and 10 cm wavelength band generators by approximately 1.5 times by means of a significant sharpening of the leading front of current pulses. It is proposed to use waveguides with shallow rectangular corrugations in relativistic BWOs. This will make it possible, while retaining the output power, to significantly increase the operating current and reduce the voltage to 300–400 kV, which simplifies the X-ray protection system considerably.
Relativistic BWOs serve also as the basis for the development of self-oscillators capable of generation of complex signals and phase-locking by outside signals, as well as multi-regime self-oscillators.