High accuracy energy determination and calibration of synchrotron radiation by powder diffraction

Abstract

Powder diffraction patterns of standard reference material LaB6 (660a) have been used to determine the energy of a synchrotron beam across the range 7-12keV with typical uncertainties of 0.1eV. Diffraction peaks were recorded on X-ray image plates over a broad range of diffracting angles. Multiple systematic errors were corrected in a robust fitting procedure, providing consistent physical results. We have shown the reliability of this method and observed limitations of reproducibility due to hysteresis by repeated multiple energy calibrations. We report accuracies as low as 13 parts per million (ppm), and demonstrate the need to accurately determine the energy of the X-ray beam during exper..