Spatially resolved 3D micro-XANES by a confocal detection scheme

Abstract

A confocal setup based on polycapillary half-lenses was used to demonstrate three-dimensional (3D) spatially resolved μ-XANES in fluorescence detection mode at the DUBBLE XAS station of the ESRF (BM26A). The incoming beam was focused using a polycapillary half-lens and a second glass polycapillary was placed in front of the energy dispersive detector to establish the confocal detection. The full-width-half-maxima along the main axes of the resulting ellipsoidal detection volume were 18.5 × 12.0 × 10.0 μm³ at the Cu K-edge. The confocal μ-XANES mode is applied in the 3D resolved study of mineral inclusions in rare natural diamonds at the Fe K edge.