Sample refreshment schemes for high repetition rate FEL experiments

摘要

Free-electron lasers offer a variety of unique properties for spectroscopy and imaging. The combination of high peak brilliance and a high repetition rate opens a window to experiments that have not been feasible so far but also introduces challenges in sample preparation and refreshment. First experiments at the Linac Coherent Light Source (LCLS) in Stanford showed the potential of free electron lasers for serial X-ray crystallography as well as for imaging non-reproducible objects. Owing to the superconducting accelerator technology, the European X-ray Free-Electron Laser Facility (European XFEL) will allow an average repetition rate of up to 27 kHz with bunch separation in the order of 200 ns. This extremely high repetition rate gives great chances for the scientific impact of the European XFEL, but it also comes with challenges for providing fresh samples for each bunch. This contribution will give an overview of the sample environment techniques that are in consideration for the European XFEL Facility. These techniques include gas phase, liquid, and aerosol sources for life science and physics experiments.