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

A synchrotron radiation X-ray powder diffractometer for samples of very sma ll amount has been developed to collect high-quality diffraction patterns u nder extreme conditions, i.e. at low temperature and/or high pressure. A ne w cylindrical imaging plate (CIP) is used as a detector, in addition to a c onventional flat-type imaging plate (FIP). By using the CIP system, the dif fraction data in a diffraction angle range -44 less than or equal to 2 thet a less than or equal to 122 degrees are collected with a dynamic range of a bout 10(6). The alignment of the diffractometer, measurement and analysis a re automatically operated by a workstation. A performance test shows that t he CIP system has spatial resolution of about 0.07 degrees with a dynamic r ange of 10(6). 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 mu g) an d a short exposure time (60 s). Examples of experiments at low temperatures under ambient and high pressures are also presented.