Fig. 1.
Single-molecule scattering and photon correlations. a A stream of randomly oriented particles is injected into the XFEL beam, hit sequentially by femtosecond X-ray pulses, and the coherently scattered photons (red dots) are recorded on the pixel detector. b In the detector plane kxky the recorded photons are grouped into triplets, each of which is characterized by distances k1, k2, k3 to the detector center (orange lines) and the angles α and β between the respective photons (orange circular arcs)