Spatial coherence studies on x-ray multilayers

The degree of coherence preservation of x-ray multilayers was investigated using Talbot imaging on the ESRF undulator beamline ID06. Several W/B 4 C multilayer mirrors with differing d-spacings were studied with monochromatic light at various photon energies. To understand the respective influence of the underlying substrate and the multilayer coatings, measurements were made under total reflection, at different Bragg peaks, and on the bare substrates. In addition, samples with different substrate quality were compared. The relation between spatial coherence preservation and the visibility of characteristic line structures in the x-ray beam will be discussed.