A novel portable energy dispersive X-ray fluorescence spectrometer with triaxial geometry

Abstract

The X-ray fluorescence technique is a powerful analytical tool with a broad range of applications such as quality control, environmental contamination by heavy metals, cultural heritage, among others. For the first time, a portable energy dispersive X-ray fluorescence spectrometer was assembled, with orthogonal triaxial geometry between the X-ray tube, the secondary target, the sample and the detector. This geometry reduces the background of the measured spectra by reducing significantly the Bremsstrahlung produced in the tube through polarization in the secondary target and in the sample. Consequently, a practically monochromatic excitation energy is obtained. In this way, a better peak-background ratio is obtained compared to similar devices, improving the detection limits and leading to superior sensitivity. The performance of this setup is compared with the one of a benchtop setup with triaxial geometry and a portable setup with planar geometry. Two case studies are presented concerning the analysis of a 18th century paper document, and the bone remains of an individual buried in the early 19th century.

Determination of gold leaf thickness using X-ray fluorescence spectrometry: Accuracy comparison using analytical methodology and Monte Carlo simulations

“…An experimental setup was assembled using a sided window X-ray tube with a Mo anode, OXFORD XTF5011 (max 50 kV, 1 mA) and a Silicon Drift Detector, thermoelectrically cooled (60EX, Vortex) (FWHM at 160 eV at Fe-Kα), with an active area of 50 mm 2 and a 25 μm thickness Be window. Monochromatization and reduction of the Bremstrahlung from the tube was obtained using a secondary Yttrium target disk (99% purity, 1.0 mm thickness, 25.0 mm diameter, GoodFellow Inc., Huntingdon, UK) in triaxial geometry as it was described in a previous work (Pessanha et al, 2017). The spot size was measured with a radiographic film producing an ellipsoid image with 17 mm × 12 mm.…”

Elemental Composition of Algae-Based Supplements by Energy Dispersive X-ray Fluorescence

“…All of the energy dispersive X-ray spectra were acquired with the use of a tri-axial setup, which lowers the detection limits of conventional XRF spectrometers through the polarization of the incident beam at a secondary target [ 56 , 57 ].…”

In vitro study of the demineralization induced in human enamel by an acidic beverage using X‐ray fluorescence spectroscopy and Raman microscopy

“…The X‐ray tube, the secondary target, and the sample are in a triaxial geometry. The background decreases with this arrangement, taking advantage of the effect of the partial polarization of the incident X‐ray beam from the tube and so improving the detection limits . The characteristic radiation emitted by the elements present in the sample was detected by a Si (Li) detector with a 30 mm 2 active area and 8 μm beryllium window.…”