Reconstruction Procedure for 3D Micro X-ray Absorption Fine Structure

Abstract

A new approach for chemical speciation in stratified systems using 3D Micro-XAFS spectroscopy is developed by combining 3D Micro X-ray Fluorescence Spectroscopy (3D Micro-XRF) and conventional X-ray Absorption Fine Structure Spectroscopy (XAFS). A prominent field of application is stratified materials within which depth-resolved chemical speciation is required. Measurements are collected in fluorescence mode which in general lead to distorted spectra due to absorption effects. Developing a reliable reconstruction algorithm for obtaining undistorted spectra for superficial and in-depth layers is proposed and validated. The developed algorithm calculates the attenuation coefficients of the analyte for the successive layers facilitating a new spectroscopic tool for three-dimensionally resolved nondestructive chemical speciation.

Elemental and Molecular Segregation in Oil Paintings due to Lead Soap Degradation

“…Finally, additional analysis including techniques that can differentiate Pb azelate and Pb palmitate, as well as studies on model paint samples, will be beneficial to further understand the mechanisms of the reactions. Confocal XRF microscopy and XANES using capillary optics 36 or tomographic techniques may also be used to provide resolution in three dimensions.…”

A setup for synchrotron-radiation-induced total reflection X-ray fluorescence and X-ray absorption near-edge structure recently commissioned at BESSY II BAMline

“…LODs Sy-TXRF (pg) LOD conventional TXRF (pg) low-power TXRF † 10 0.06 < detection limit 100 0.07 8 because self-absorption effects well known in fluorescence yield XANES increase for small angles as applied in TXRF. However, a number of publications addressed this problem in the past and made modelling and experimental solutions available to solve this problem (Lü hl et al, 2012;Meirer et al, 2008Meirer et al, , 2009Menzel et al, 2013).…”

Confocal X-ray technology based on capillary X-ray optics

“…A reliable reconstruction algorithm for obtaining undistorted spectra for superficial and in-depth layers was developed to calculate the attenuation coefficients of the analyte for successive layers, which facilitates a new spectroscopic tool for 3D resolved nondestructive chemical speciation (Lühl et al 2012(Lühl et al , 2013.…”

“…In recent years, the confocal technology based on CXRO has become popular and widely used in confocal X-ray fluorescence (XRF) , Nakazawa and Tsuji 2013a,b, Peng et al 2014a, confocal X-ray absorption fine structure (XAFS) (Lühl et al 2012, Menzel et al 2013, confocal XRD (Sosa et al 2014), confocal small-angle X-ray scattering (SAXS) , confocal X-ray imaging (Yin et al 2006, Sun andMacDonald 2013), and confocal X-ray scattering (Li et al 2015a).…”