view article
Figure 5
The horizontal coherence length calculated from the source properties of PETRA III and PETRA IV as a function of photon energy (top). The speckle contrast βcl as a function of beam size calculated according to equation (14[link]) [photon energies 8 keV (red), 15 keV (green) and 25 keV (blue)] (bottom). The dashed line corresponds to the horizontal coherence length at P10 PETRA III, the solid line represents the horizontal coherence length expected with PETRA IV. The q value is q = 0.9 nm−1 and the sample thicknesses are d = 1.0, 6.5 and 23 mm corresponding to the absorption length of water at the respective photon energies.

IUCrJ
Volume 6| Part 5| September 2019| Pages 794-803
ISSN: 2052-2525
https://doi.org/10.1107/S2052252519008273