The application of a position-sensitive detector to high-pressure X-ray diffraction using a diamond-anvil cell

A position-sensitive detector (PSD) for Mo Kα radiation has been successfully applied to detect very weak X-rays diffracted from an extremely small volume of specimen compressed in a diamond-anvil high-pressure cell. The PSD can cover a scattering-angle range of 22.6° with an angular resolution of 0.038: in a single measurement. Remarkably rapid recording of diffraction patterns with a high S/N ratio is performed with this method at pressures higher than 10 GPa. Some diffraction patterns of iodine near the insulator-metal transition around 16–18 GPa are shown to demonstrate the usefulness and power of this PSD system.