Suitability of polycapillary optics for focusing of monochromatic synchrotron radiation as used in trace level micro-XANES measurements

Abstract

In this study a monolithic polycapillary half-lens was evaluated as a micro-focusing device for monochromatic synchrotron radiation. The tested optic produced an X-ray micro-beam of 37–53 microns in the energy range of 6–19 keV with a maximum intensity gain of about 600 with respect to the primary beam. When applied to X-ray fluorescence (XRF) analysis, absolute detection limits in the range of 0.06–1 pg were measured, coupled with relative detection limits of 0.3–200 ppm for the atomic number range of 20–40. The use of the polycapillary lens was demonstrated by performing microscopic X-ray absorption near edge structure (XANES) measurements in fluorescence mode on transition metals (concentration range 40–100 ppm) in fly ash particles.