A method for the quantitative determination of synchrotron radiation X-ray spectra for absolute XRF trace element detection

In the X-ray energy range the principal calculability of the synchrotron radiation flux-density and polarisation spectra is limited in practice by the fact that the essential parameters of vertical electron beam cross-section and -divergence are not well known due to instabilities that can occur at higher stored currents. This difficulty in calculating absolute X-ray spectra from first principles can be overcome by a semi-empirical method. By a polarisation measurement over a large energy range, effective electron beam parameters can be defined that lead to reliable calculated X-ray flux-density and polarisation spectra. With these data experimental scattering spectra could be verified extremely well on an absolute scale over an energy range of 2 keV to 35 keV. This is a necessary premise for the development of a method of absolute mass determination from XRF spectra with synchrotron radiation excitation. (orig.)