Model for the bremsstrahlung spectrum in EPMA. Application to standardless quantification

Abstract

The Kramers expression was modified after fitting 52 spectra from targets of diverse composition at several incident energies. The function obtained describes adequately the continuum x-ray spectrum observed when a bulk, homogeneous and polished sample is irradiated by an electron beam with energies ranging from 5 to 35 keV. The targets considered are pure and multicomponent, covering elements from boron to bismuth. In addition to simplicity, the new expression shows very good agreement with measured spectra—much closer than other models assessed. The proposed function was applied to a standardless quantification method based on peak-to-background ratios. © 1998 John Wiley & Sons, Ltd.