Séminaire

Mardi 18 Octobre 2022 à 11h00.

Magnetodynamics at the FERMI free electron laser.

''The scope of this presentation is to outline the main marks and performances of the MagneDyn beamline which was designed and built to perform ultrafast magnetodynamic studies in solids. Open to users since 2020, MagneDyn operates with variable circular and linear polarized femtosecond pulses delivered by the externally laser-seeded FERMI free-electron laser (FEL). The very high degree of polarization, the high pulse-to-pulse stability, and the photon energy tunability in the 50-300 eV range allow to perform advanced time-resolved magnetic dichroic experiments at the K-edge of light elements, e.g. carbon and at the M- and N-edge of the 3d-transition-metals and rare earth elements, respectively. To this end two experimental end-stations are available. The first is equipped with an in-situ dedicated electromagnet, a cryostat, and an extreme ultraviolet (EUV) Wollaston-like polarimeter. The second, designed for carry-in users instruments, hosts also a spectrometer for pump-probe resonant X-ray emission and inelastic spectroscopy experiments with a sub-eV energy resolution. A pump laser setup, synchronized with the FEL-laser seeding system, delivers sub-picosecond pulses with photon energies ranging from the mid-IR to near-UV for optical pump-FEL probe experiments with a minimal pump-probe jitter of few femtoseconds. The overall combination of these features renders MagneDyn a unique state-of-the-art tool for studying ultrafast magnetic phenomena in solids.''