Measurements of single-shot attosecond X-ray pulses at high repetition rate

Electron dynamics in molecules occur on attosecond timescales and drive fundamental processes such as photosynthesis, catalysis, and chemical bond transformations. Understanding these phenomena requires tools with both high temporal resolution and the capability to probe molecular dynamics at high repetition rates. Here, we present the first single-shot measurements of attosecond soft x-ray pulses at the superconducting LCLS-II accelerator. Using an angle-resolving electron time-of-flight spectrometer, we perform angular streaking measurements with high energy and angular resolution, enabling a complete reconstruction of the spatial and temporal profiles of the pulses. These measurements showcase the attosecond science capabilities of LCLS-II at unprecedented repetition rates and provide the foundation for controlling and shaping x-ray pulses to study ultrafast dynamics in complex systems with precision.