The beam transport system for the Small Quantum Systems instrument at the European XFEL: optical layout and first commissioning results

The Small Quantum Systems instrument is one of the six operating instruments of the European XFEL, dedicated to the atomic, molecular and cluster physics communities. The instrument started its user operation at the end of 2018 after a commissioning phase. The design and characterization of the beam transport system are described here. The X-ray optical components of the beamline are detailed, and the beamline performances, transmission and focusing capabilities are reported. It is shown that the X-ray beam can be effectively focused as predicted by ray-tracing simulations. The impact of non-ideal X-ray source conditions on the focusing performances is discussed.

Automated summary

The Small Quantum Systems instrument at the European XFEL is designed for atomic, molecular, and cluster physics research. This instrument has undergone a commissioning phase and started user operation in 2018. The article describes the design and characterization of the beam transport system, provides details on the X-ray optical components, and reports on the performance, transmission, and focusing capabilities of the beamline. It highlights that the X-ray beam can be effectively focused, as predicted by ray-tracing simulations, and discusses the impact of non-ideal X-ray source conditions on focusing performances.