Cavity resonator free electron lasers as a source of stable attosecond pulses
SUPA, Department of Physics, University of Strathclyde - Glasgow, UK, EU
2 ASTeC, STFC Daresbury Laboratory and Cockcroft Institute - Warrington WA4 4AD, UK, EU
Accepted: 13 October 2011
High-gain Free Electron Laser amplifiers are a potential source of single X-ray attosecond pulses and Attosecond Pulse Trains. Single-pulse output from short electron bunches is prone to significant power and arrival-time fluctuations. A Mode Locked Optical Klystron configuration of the FEL amplifier predicts generation of a frequency comb that may be locked to give APT output. In this paper it is shown using numerical simulations that a low feedback (so-called Regenerative Amplifier) FEL cavity resonator configuration can significantly improve output stability for single-pulse operation. The MLOK configuration may also be used in a cavity resonator to generate a frequency comb with spacing much greater than those of the axial cavity modes. As with the MLOK amplifier case, these modes can lock to generate a stable pulse train, each of a few optical cycles.
PACS: 41.60.Cr – Free-electron lasers / 42.55.Vc – X- and γ-ray lasers / 42.65.Re – Ultrafast processes; optical pulse generation and pulse compression
© EPLA, 2011