title: Three-dimensional trace element analysis by confocal X-ray microfluorescence imaging.
abstract: A three-dimensional (3D) variant of scanning micro X-ray fluorescence (XRF) is described and evaluated at the ID18F instrument of the European Synchrotron Radiation Facility (ESRF). The method is based on confocal excitation/detection using a polycapillary half-lens in front of the energy-dispersive detector. The experimental arrangement represents a significant generalization of regular two-dimensional (2D) scanning micro-XRF and employs a detector half-lens whose focus coincides with that of the focused incoming beam. The detection volume defined by the intersection of the exciting beam and the energy-dependent acceptance of the polycapillary optics is 100-350 mum(3). Minimum detection limits are sub-ppm, and sensitivities are comparable with regular scanning XRF. Next to the reduction of in-sample single/multiple scattering, the setup provides the possibility of sample depth scans with an energy-dependent resolution of 10-35 mum in the energy range of 3-23 keV and the possibility of performing 3D-XRF analysis by simple XYZ linear scanning. This provides a suitable alternative to X-ray fluorescence tomography. The method is illustrated with results of the analysis of solid inclusions in diamond and fluid inclusions in quartz.
authors.affiliation: MiTAC, University of Antwerp, Universiteitsplein 1, B-2610 Wilrijk, Belgium. laszlo.vincze@ua.ac.be
authors.forename: Laszlo
authors.initials: L
authors.lastname: Vincze
authors.forename: Bart
authors.initials: B
authors.lastname: Vekemans
authors.forename: Frank E
authors.initials: FE
authors.lastname: Brenker
authors.forename: Gerald
authors.initials: G
authors.lastname: Falkenberg
authors.forename: Karen
authors.initials: K
authors.lastname: Rickers
authors.forename: Andrea
authors.initials: A
authors.lastname: Somogyi
authors.forename: Michael
authors.initials: M
authors.lastname: Kersten
authors.forename: Freddy
authors.initials: F
authors.lastname: Adams