Figure 4
Intensities of diffraction reflections of a LaB6 reference powder, collected on the D2AM beamline goniometer with a 0.4 mrad quasi-parallel beam of size 80 µm × 150 µm and an energy of 22 keV, filtered by the two single-crystal-comb and Soller-collimator blocks, with an angular pitch of 0.1° between the Si(111) crystals. (a) Signals from the (110) reflection of LaB6, received by the XPAD S70 detector, which visualizes the 20 beams filtered by the single-crystal-comb. (a′) Intensities of the 20 signals filtered by each Si(111) analyser crystal for this (110) reflection (with a different colour for each analyser crystal). (a′′) Superposition of these 20 filtered intensities and their sum (divided by 10). (b, b′, b′′) Signals received by the 2D detector and profiles of these 20 beams filtered by each Si(111) analyser crystal for the same (110) reflection which was measured several days later, after data collections made with the same system on several other samples; we note a good constancy of the intensities of each of the beams filtered by each analyser crystal. (c, c′, c′′) Intensities of the diffracted lines filtered by each Si(111) analyser crystal at different Bragg angles corresponding to the LaB6 reflections: (c) (100), (c′) (220) and (300) and to (c′′) weak high angles reflections. (d, d′, d′′, d′′′) Superpositions of the 20 diffracted intensities filtered by each Si(111) analyser crystal of the single-crystal-comb, and their sum (divided by 10), for the LaB6 reflections (100), (210), (320) and (321). |