Comparison of conventional and total reflection excitation geometry for fluorescence X-ray absorption spectroscopy on droplet samples

摘要

X-ray absorption fine structure (XAFS) experiments in fluorescence mode have been performed in total reflection excitation geometry and conventional 45 deg /45 deg excitation/detection geometry for comparison.The experimental results have shown that XAFS measurements are feasible under normal total reflection X-ray fluorescence (TXRF) conditions,i.e.on droplet samples,with excitation in grazing incidence and using a TXRF experimental chamber.The application of the total reflection excitation geometry for XAFS measurements increases the sensitivity compared to the conventional geometry lading to lower accessible concentration ranges.However,XAFS under total reflection excitation conition fails for highly concentrated samples because of the self-absorption effect.