Schematics of the x-ray grating interferometry setup used to study the superposition principle in directional dark-field imaging.

The simulated setup consisted of an x-ray source (X) two layers of highly oriented structures (cylinders, and ), the grating interferometer ( and ) and a detector (D). For the experiment an additional grating () was used right behind the source to enforce the coherence conditions required by the interferometer. The sample layers were rotated independently from each other around the optical axis to retrieve the direction-dependence of the dark-field signal.