[IEEE 2019 44th International Conference on Infrared, Millimeter, and Terahertz Waves (IRMMW-THz) - Paris, France (2019.9.1-2019.9.6)] 2019 44th International Conference on Infrared, Millimeter, and Terahertz Waves (IRMMW-THz) - Regime of Multi-Stage Trapping in Free Electron Lasers

摘要： Novel schemes of a trapping regime in FELs were studied. Proof-of-principle experiments on realization of “non-resonant” trapping were performed at Ka-band. For short-wavelength FELs we describe two different ways of the use of regime of “multi-stage” trapping. First, this regime can be a way for efficiency enhancement of FELs operating in SASE regime. Second, multi-stage amplification of a single-frequency RF signal can lead to an effective cooling of the operating electron beam.