Figure 1. Schematic of the experimental setup used for X-ray near-field ptychography.

(a) X-rays from an undulator source (not depicted) are focussed by Kirkpatrick-Baez mirrors (KB) to create a virtual point source and an expanding cone beam illumination to record a magnified near-field Fresnel diffraction pattern (H) of the sample (S). A stationary diffuser consisting of a piece of paper can be placed into the beam to modify the wavefront. The sample mounted on a high-precision stage is moved as depicted in (b) transversally.