Synchrotron radiation X-ray powder diffractometer with a cylindrical imaging plate

A synchrotron radiation X-ray powder diffractometer for samples of very small amount has been developed to collect high-quality diffraction patterns under extreme conditions, i.e. at low temperature and/or high pressure. A new cylindrical imaging plate (CIP) is used as a detector, in addition to a conventional flat-type imaging plate (FIP). By using the CIP system, the diffraction data in a diffraction angle range −44 ≤ 2θ ≤ 122° are collected with a dynamic range of about 10⁶. The alignment of the diffractometer, measurement and analysis are automatically operated by a workstation. A performance test shows that the CIP system has spatial resolution of about 0.07° with a dynamic range of 10⁶. The diffraction pattern of a standard sample of Si measured by the CIP system has high quality; the refinement of the structure reaches R_w = 3.68% even in the case of a small amount of sample (about 2 µg) and a short exposure time (60 s). Examples of experiments at low temperatures under ambient and high pressures are also presented.