Fig. 1

Schematics of the hard X-ray delay line instrument. An incoming ultrashort X-ray pulse is split with a thin silicon single crystal splitter (SP1). The pulses are directed along different pathways via reflective Bragg optics (R1–R6). The relative path length difference between the lower branch (LB) and the upper branch (UB) introduces a time delay Δ t (here 1.3 ns) between the split pulses