Final Report of the International Project for the Calibration of Absolute Intensities in Small-Angle X-ray Scattering

Abstract

An international intercomparison project was performed to test the reproducibility and the comparative accuracy of the various absolute intensity calibration techniques in current use in small-angle X-ray scattering with the participation of fifteen investigators from eight different laboratories in six countries. In the project, the absolute differential X-ray scattering cross sections of standard samples of glassy carbon and polystyrene were calibrated using five different calibration techniques and two different X-ray wavelengths. The results have been intercompared with a variety of statistical techniques. It is concluded that angularly dependent errors associated with determining the zero of angle, dead-time corrections, collimation corrections, and insufficiently close data point spacing are more important in accounting for discrepancies between laboratories than are differences in the absolute intensity calibration methods themselves.