Software for automatic calibration of synchrotron powder diffractometers

An automatic procedure to calibrate angular-dispersive monochromatic diffraction instruments has been developed at the Daresbury Synchrotron Radiation Source. The procedure uses a macro language to control the powder diffraction instruments to locate Bragg reflections and perform peak-centre refinement from a standard reference material. The information obtained is used to refine the wavelength of the radiation used and the angular offset of the detector arm. The concept and implementation of the new software are described with applications to demonstrate its viability. The results of a reliability and accuracy study are also presented.