Quenching of the Resonant Magnetic Scattering by Ultra-Short Free-Electron Laser Light Pulses

The new free-electron laser (FEL) sources provide radiation with unprecedentedparameters in terms of ultrashort pulse length, high photonflux, and coherence. These properties make FELs ideal tools forstudying ultrafast dynamics in matter on a previously inaccessiblelevel. Yet, FELs do not only probe matter, but can also drive it inhighly excited states which are otherwise inaccessible.Here, we report on a resonant magnetic scattering experiment, wherethe focussed FEL light pulses probe the magnetic domain system of athin magnetic film. Both, single and double FEL pulses at differentfluences are used to follow the quenching of the resonant scatteringefficiency