High-frequency devices with weakly relativistic hollow thin-wall electron beams

Abstract

Slow-wave devices with hollow electron beams and azimuthally symmetric corrugated operating waveguides can be very effective not only for relativistic but also weakly relativistic particle energies. In the weakly relativistic case, the use of hollow beams permits a significant increase in the diameter of the beam channel and, simultaneously, a drastic decrease in the required current density and heat load at the interaction structure wall in comparison with the conventional devices, which basically exploit thin pencil-like beams. Advantages of the hollow beams in the achievement of continuous wave (CW) and long-pulse generation can manifest themselves in a wide range from gigahertz to terahertz frequencies. As an example of the concept, a W-band oscillator (orotron) with kilowatt output power in CW regime is discussed in detail. Modification of the microwave system makes it possible to implement high-power frequency-tunable BWOs, klystron or TWT amplifiers, and many types of hybrid devices.