Figure 7
Sandwich-comb analyser block with Si(111) crystals working in reflection mode. (a) Sandwich-comb made by 3D printing. In this example we inserted a Si(111) single-crystal plate into all of the slots spaced 1.7 mm apart and corresponding to a crystal pitch of 0.1°. (b) Angular measurements of the beam filtered by this block and therefore of the tilt of the analyzer crystals. (c) Diffraction measurements filtered by a sandwich-comb having an angular pitch of 0.2° between the Si(111) crystals and being associated with a Soller-collimator block having a pitch of 0.1° (due to the unavailability during this experiment of a Soller collimator with a 0.2° pitch), so this mismatch led to more restrictive intensity cuts of the filtered beams; this Soller-collimator block is fixed on the 2ΘA arm at a distance (Ds = 1033–1093 mm) from the sample in front of the hybrid photon-counting XPAD S70 detector (Basolo et al., 2007; Medjoubi et al., 2010); this 2D detector is made up of a succession of seven chips supporting pixels (yellow zones) and the dimension of each pixel of the XPAD S70 detector is 125 µm. (d) Scheme of 22 keV beam paths filtered every 0.2°, over a range of 6°, by two rigid blocks: the sandwich-comb of Si(111) crystals and the Soller-collimator. The distance between the sample and the MAD block is large (D = 973 mm). |