CURRENT WORK ON TOTAL REFLECTION X-RAY-FLUORESCENCE SPECTROMETRY AT THE GKSS RESEARCH-CENTER

Total reflection x-ray fluorescence spectrometry (TXRF) was initially developed in order to enhance the detection performance in energy-dispersive XRF using appropriate surfaces as sample carriers in the total reflection mode. The extension of this method to the analysis of surfaces required additional considerations together with refined instrumental design. As a secondary effect, the detection limits for trace analysis have been reduced by a further order of magnitude. In addition, new software has been developed. Special quantification procedures for surface analysis became necessary because of the complex behaviour of the primary intensity in near-surface layers. The intensities are calculated on the basis of the Fresnel equations. Examples are given for the determination of thickness, clemental composition and density of surface layers in the nanometre range.