87 research outputs found
Inter-laboratory comparison of a WDS-EDS quantitative X-ray microanalysis of a metallic glass
We conducted an inter-laboratory study of a metallic glass whose main
component is nickel. Two determinations of the mass fractions of the different
elements present within the sample were asked to the participants: one at an
acceleration voltage of 15 or 20 kV and another one at 5 kV. We compare the
mass fractions obtained from wavelength dispersive (WDS) and energy dispersive
spectrometries (EDS) and also try to find an influence of the kind of EDS
detector and its entrance window, the background subtraction method, the use or
not of standards as well as the quantification method. Both means of WDS and
EDS mass fractions are close to the reference values. The dispersion of the
results was larger at 5 kV than at 15-20 kV owing to the use of the L lines
rather than K lines and to the lowest collected intensities. There is an
exception with the case of boron because at the lowest voltage, the excitation
condition is more favourable for the production of the K line. It appears that
the dispersion of the results is larger with EDS than with WDS but it was not
possible to find a correlation between the large dispersion and one of the
considered experimental parameters and quantification factors. Thus, one can
think that electron microprobes are inherently better for the determination of
mass fractions or that the implementation of quantitative analysis must be
optimized for some cases, especially in SEMs.Comment: Members of the GN-MEBA, SEMPA users group and Belgian laboratories
coordinated by Universite Catholique de Louvain are thanked for their
participation to this inter-laboratory stud
On the Kramers-Kronig transform with logarithmic kernel for the reflection phase in the Drude model
We use the Kramers-Kronig transform (KKT) with logarithmic kernel to obtain
the reflection phase and, subsequently, the complex refractive index of a bulk
mirror from reflectance. However, there remains some confusion regarding the
formulation for this analysis. Assuming the damped Drude model for the
dielectric constant and the oblique incidence case, we calculate the additional
terms: phase at zero frequency and Blashke factor and we propose a reformulated
KKT within this model. Absolute reflectance in the s-polarization case of a
gold film is measured between 40 and 350 eV for various glancing angles using
synchrotron radiation and its complex refractive index is deduced using the
reformulated KKT that we propose. The results are discussed with respect to the
data available in the literature.Comment: 18 pages, piblished in j. Mod. Opt. 57, 1504 (2010
DUVEX: An X-ray counting system based on YAG:Ce scintillator
International audienceA detector system, called DUVEX, has been developed for the soft-X-ray and extreme ultraviolet domain. It consists of a YAG:Ce scintillator coupled to a photomultiplier module working under vacuum in counting mode. The design and the performances of this detector in terms of yield, absolute efficiency, response and noise are reported. Spectra in the soft X-ray range of different elements (W, Ag, Al, Mg, Cu, N, C and B) obtained in WDS mode using this detector are presented. DUVEX appears as a competitive detection tool in terms of cost and easiness of implementation
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