Figure 1
Experimental layout with the beam from the APS 1-BM bending magnet incident from the left. The first two crystal reflections were in the beamline monochromator. All four crystals were set to diffract in the vertical plane. For the final asymmetric crystal the grazing exit angle at 8.500 keV was 0.41°. The Talbot interferometer consisted of a checkerboard grating with period of 4.8 µm and located 35.5 m downstream of the bending magnet together with an Andor Neo CMOS detector having a pixel size of 6.5 µm. The detector recorded visible-light images from a LuAG:Ce scintillator magnified by a 10× lens to yield a 0.65 µm per pixel resolution. The asymmetric crystal was located 3.32 m upstream of the grating. Several hundred images were obtained at scanned distances between the grating and the scintillator out to 900 mm. |