Speaker
Description
X-ray free-electron lasers (XFELs) such as SwissFEL produce extremely intense, ultrashort X-ray pulses that enable experiments probing matter on the femtosecond timescale and Angstrom length scale. Unlike storage-ring light sources, XFEL pulses exhibit significant pulse-to-pulse variations in properties such as intensity, spectrum and arrival time. In addition, many experiments operate in destructive regimes where samples are modified or destroyed after each exposure. These characteristics make single-shot correlated data acquisition essential: detector data, beam diagnostics, instrument configuration and metadata must all be recorded and associated for every individual pulse to enable data analysis and interpretation.
We present an overview of the SwissFEL measurement stack, focusing on how experimental workflows are orchestrated across the facility. The architecture integrates individual libraries and services for experiment control, detector acquisition, metadata collection, online analysis, visualization and storage into a unified system that supports both interactive user experiments and automated operation. Experimental data is recorded and buffered for downstream processing, enabling real-time operations such as data reduction, monitoring and visualization, while also ensuring reliable long-term storage.
Users interact with the system through the slic library, which provides a high-level interface for defining devices and controlling experiments. The library communicates with backend services through the sf-daq API that validates requests and coordinates access to the underlying infrastructure via a message broker. To ensure reproducibility and operational reliability, the software stack is deployed through automated pipelines and continuously monitored to minimize downtime during user operation.
