High‐resolution and high‐intensity powder diffractometer at BL15XU in SPring‐8

A new ultra‐high‐resolution powder diffractometer for synchrotron radiation has been constructed at beamline BL15XU, SPring‐8. The two‐axis diffractometer is optimized for high‐flux and high‐coherent X‐ray beams, which are provided by combining a planar undulator and a large offset rotated‐inclined Si(111) double‐crystal monochromator. The optics design of the diffractometer is based on transmission geometry, which employs a capillary specimen and reflection geometries using a flat‐plate specimen. The intensity data are collected using a 2θ step‐scan technique in both geometries. The diffractometer can be arranged in a variety of optical configurations, e.g. simple receiving slits, flat crystal analyzer of Ge(111) or Si(111), and in‐vacuum‐type long horizontal parallel slits. A minimum full width at half‐maximum against 2θ was 0.00572° at λ = 0.63582 Å for the (200) reflections from Si powder in the transmission geometry employing the Ge(111) crystal analyzer. A wide temperature range (32–900 K), which is controlled by a He/N 2 gas stream system, is available. 288 structure parameters of a zeolite ZSM‐5 sample have been demonstrated to successfully refine with a R wp value of 6.96% by a Rietveld analysis of the high‐resolution powder diffraction data from a 1 mm‐diameter capillary specimen.