A HIGH-RESOLUTION LABORATORY-BASED HIGH-PRESSURE X-RAY-DIFFRACTION SYSTEM

An improved x-ray powder diffraction system for use with a diamond anvil cell is described. To obtain a small, strong, nearly monochromatic, low divergence incident beam for x-ray powder diffraction, a focusing technique based on the Johansson-Guinier principal is employed. The system consists of a rotating anode x-ray generator, a quartz curved monochromator, a horizontal collimator, motor-driven x, y, and z stages, and a Debye-Scherrer-type film cassette together with a lever-arm-type Mao-Bell diamond anvil cell. The system is designed to function in an analogous manner to synchrotron-based diffraction systems. Its performance is superior to conventional laboratory-based diffraction systems. Many experiments that formerly required a synchrotron source can now be performed in the laboratory. (C) 1995 American Institute of Physics.