Performance of a diamond-anvil high-pressure x-ray diffractometer in the Guinier geometry

In this paper, the performance of a novel high-pressure diamond-anvil powder x-ray diffractometer in Guinier geometry is reported. The diffractometer is a combination of a curved quartz-crystal monochromator, a Mao–Bell-type diamond-anvil cell, a flat position sensitive detector, and a Huber goniometer with compound stages to realize this geometry. The incident x-ray beam is from a rotating anode x-ray generator. It is shown that the above experimental arrangement results in an enhanced S/N ratio, improvement in resolution, and reduction of the data-acquisition time. Test results on UAl2 are presented to demonstrate the advantages of the setup in the study of phase transitions at high pressure.