Elemental analysis by high‐energy electron excitation

Abstract

The possibility of using high‐energy β‐particles (102–103 keV) to induce the emission of characteristic x‐rays from pure chemical elements, with important improvements with respect to conventional excitation methods, has been recently reviewed. An excitation procedure named BIXE (β‐induced x‐ray emission) is used for implementing a spectrometric technique along the lines developed for EPMA (electron probe microanalysis). We have found that by using BIXE it is possible to determine binary sample compositions of elements present at concentrations higher than 1%, by comparisons with reference samples to obtain calibration curves. Experience with EPMA shows that when ternary and higher order samples are analyzed, the use of reference samples is not enough and it is necessary to perform theoretical corrections to the relationship between the line intensity and the corresponding concentrations, as a suitable complement to the analytical procedure. Semi‐quantitative results are thus obtained with corrections applied through the ZAF method usually used in EPMA. In this work we concentrated in finding whether calibration curves as used in EPMA (where the electron beam is monochromatic) can be used in BIXE, where the electron beam is polychromatic (the β spectrum). We expect that BIXE can be developed as a spectrometric technique whose main advantages are that it is a low‐cost technique suitable for in situ studies and that the experimental arrangement and data acquisition and its evaluation are comparatively simple. Copyright © 2004 John Wiley & Sons, Ltd.

Atomic spectrometry update. X-ray fluorescence spectrometry

“…Analysts struggling with the detection at mg g À1 levels will be familiar with efforts to reduce Bremsstrahlung, which is often the main contribution to the background under characteristic peaks in conventional systems. PIXE systems that operate with protons from electrostatic accelerators which generate reduced Bremsstrahlung have now been challenged by BIXE, b-induced X-ray emission, 3 for the generation of characteristic X-rays. The authors expect that BIXE will be developed to offer a low cost technique for in situ studies, although readers with longer memories may recall the Betaprobe of the 1970s that was based on these excitation principles.…”

“…In a second paper 16 the latest developments in SDD were described in which the existing energy resolution of typically 145 eV at 5.9 keV has been significantly improved to a reported 124 eV at 5.9 keV when operated at a readily achievable À10 Celsius. The latest design, the 'SDD 3 ' or teardrop, has the integrated FET moved to the edge of the SDD sensor itself, which further reduces the noise by allowing the FET to be shielded from the direct X-ray flux entering the detector. The author also described an innovative multichannel SDD array of 12 SDD units arranged in a torus, the centre of which had a laser cut hole through which the sample could be irradiated.…”