The possible contributions of vacuum electronics to terahertz radiation sources

This paper discusses the possible contributions of vacuum electronics to terahertz sources development. Terahertz generation and amplification based on relativistic electron beams and intense fields. Terahertz radiations are generated by microwave/millimeter wave devices, Cherenkov radiation type devices, electron cyclotron maser, free electron lasers. The scattering of electromagnetic wave from the front of ionization (plasma) or electron beams are discussed and examined.