bluuebunny/crossref_metadata_2025_split huggingface dataset:
Fundamental algorithm between concentration and intensity in XRF analysis 2—practical application
Authors: Rousseau Richard M. 
Published: May 2005

AbstractIn Part 1, a new formalism was proposed to correct with accuracy the matrix effects in XRF analysis. In this paper it is shown how to adapt this new formalism to practical situations. From an estimate of composition calculated by the Claisse–Quintin algorithm and an appropriate calibration, the new algorithm is used to refine the estimated composition for greater accuracy. This last approach is equivalent to the ‘fundamental parameters’ method but is presented in a simpler version adaptable to any mini‐computer.
Concentration mapping—a software package for the quantitative determination of two‐dimensional elemental distribution by an electron probe microanalyser
Authors: Mayr M. , Angeli J. 
Published: May 2005

AbstractDevelopments starting from known digital mapping techniques led to a powerful and versatile software package, Concentration Mapping (CM), the advantages of which over former programs are as follows: up to 18 elements can be measured; correction calculations can be applied to obtain quantitative results; additional information may be obtained by further data processing; several programs for special data readout, phase analysis and statistical calculations are available; a very efficient automation system makes extended investigations practicable in an economical manner. Some examples of applications are given to demonstrate the extensive information from CM investigations which could not be achieved easily with customary electron probe microanalysis systems.
An analytical algorithm for calculation of spectral distributions of x‐ray tubes for quantitative x‐ray fluorescence analysis
Authors: Pella P. A. , Feng Liangyuan , Small J. A. 
Published: May 2005

AbstractFundamental parameter methods for quantitative x‐ray fluorescence analysis require a knowledge of the spectral distributions of x‐ray tubes used for sample excitation. The theoretical models for the calculation of the spectral distributions include a number of parameters which are not known with sufficient accuracy. Also, spectral distributions have been measured for only a few x‐ray tubes operated at 45–50 kV. We have developed an algorithm for calculating x‐ray tube spectral distributions by utilizing extensive electron microprobe data obtained under various operating conditions with a Si(Li) detector. The algorithm includes the calculation of the continuum and the ratio of the characteristic line(s) to the underlying continuum intensity at the wavelength of the characteristic line(s).
A general characteristic fluorescence correction for the quantitative electron microbeam analysis of thick specimens, thin films and particles
Authors: Armstrong John T. , Buseck Peter R. 
Published: May 2005

AbstractA rigorous, general characteristic fluorescence correction for the electron microprobe analysis of samples of given geometry is developed, and specific versions of this equation are presented for the calculation of the fluorescence produced (a) within a homogeneous thin film, (b) in a thin film by x‐ray emission from substrate layers of arbitrary thickness and (c) in a spherical particle. Results of the use of these equations are compared with those obtained using empirical expressions for thin films and show that the empirical expressions are accurate only for films less than 1 μm in thickness. A simplified empirical correction is proposed for particles that is in good agreement with the rigorous correction. The results of calculations using these expressions show that a 2000 Å thick film or a 1 μm diameter particle typically has about 10% of the relative contribution from characteristic fluorescence as occurs in an infinitely thick polished specimen (TPS), a 1 μm thick film has about 30–40% of the contribution in a TPS and a 10 μm diameter particle has more than 50% of the contribution in a TPS. Thus, in particular matrices, certain elements in a 2000 Å thin film or a 1 μm particle can have characteristic fluorescence corrections as high as 5%.
Determination of the valence of the iron in welding fumes with the Kβ emission spectrum
Authors: Tanninen V.‐P. , Mikkola E. , Hyvärinen H.‐K. , Grekula A. , Kalliomäki P.‐L. 
Published: May 2005

AbstractThe average valence of the iron present in the most common types of welding fumes was studied using Fe Kβ emission lines and a flat crystal spectrometer. Analysis of the energy separation Kβ1,3 – Kβ′ and the intensity ratio of the Kβ′ to Kβ1,3 yielded estimates of the predominant valence state of iron in its oxidic compounds. The presence of pure iron in the four different welding fumes is also discussed on the basis of the x‐ray emission analysis.
Measurement of L and M shell x‐ray production cross‐sections by 6 keV photon
Authors: Shatendra K. , Singh N. , Mittal R. , Allawadhi K. L. , Sood B. S. 
Published: May 2005

AbstractThe cross‐sections for the production of L and M shell x‐rays in some elements by 5.959 keV photons have been measured in order to provide data for use in photon‐induced x‐ray fluorescence analysis. An attempt has been made to interpret the experimental data in terms of the theoretical sub‐shell photoionization cross‐sections, fluorescence and Coster–Kronig yields wherever available. In general, an agreement between the experimental and calculated values was found for the L shell. However, for the M shell, sufficient data for comparison were not available.
Quantitative electron probe microanalysis of carbon in binary carbides. II—data reduction and comparison of programs
Authors: Bastin G. F. , Heijligers H. J. M. 
Published: May 2005

AbstractThe performances of four current matrix correction programs have been tested on a data file of measurements on 13 binary carbides between 4 and 30 kV. Both the metal lines as well as the carbon Kα line have been measured, which resulted in 145 k ratios for the metals (relative to elemental standards) and 117 integral k ratios for carbon Kα (relative to Fe3C).Evidence is presented that the existing sets of mass absorption coefficients for carbon Kα radiation are perhaps not fully consistent and a new set is therefore proposed, which is in better agreement with the experimental results. Finally, it is shown that the modified Gaussian ϕ(ρz) approach, when used in conjunction with the new set of mass absorption coefficients, leads to unexpectedly good results, with a relative root‐mean‐square value of 3.7%. This demonstrates that even for carbon very good accuracy can be obtained, provided that proper care is exercised in the measurements and the proper procedures are followed.
Quantitative analysis of binary mixtures using a simple x‐ray fluorescence technique
Authors: Mittal Raj , Allawadhi K. L. , Sood B. S. 
Published: May 2005

AbstractA method is described for the quantitative analysis of binary mixtures using a simple x‐ray fluorescence technique. It requires neither special preparation of thin samples nor corrections for absorption and enhancement effects. Enhancement effects are avoided using selective excitation and absorption is estimated in terms of intensities of the measured x‐rays. Linear calibrations requiring the use of only two standards are obtained. The application of the method is illustrated with six different binary mixtures.
Calculation of the influence coefficients for the claisse–quintin algorithm
Authors: Wadleigh Kevin R. 
Published: May 2005

AbstractRousseau derived the Claisse—Quintin (C—Q) equation from Sherman's equation. His theoretical description of the influence coefficients used in the C—Q equation is not correct. Also, Rousseau and Claisse as well as Rousseau gave methods for calculating influence coefficients for the C—Q equation but the coefficients listed in their papers are in error. The purpose of this paper is two‐fold: to give a set of equations that contain the correct theoretical description of the influence coefficients, and to give the correct equations for the calculation of these influence coefficients.
A comprehensive alpha coefficient algorithm (a second version)
Authors: Rousseau Richard M. 
Published: May 2005

AbstractAn expression proposed by Lachance is suggested to correct for matrix effects in any system analysed by X‐ray fluorescence. If, for any reason, an analyst does not wish to use the fundamental parameters approach, this expression is a good alternative, yielding accurate results. It is in agreement with the theory and uses influence coefficients calculated from equations containing fundamental parameters only. It is compared with three other expressions correcting for matrix effects and its accuracy is illustrated by calculations for some hypothetical specimens.
Control of chemical composition in tin–lead commercial alloys by wavelength‐dispersive X‐ray spectrometry
Authors: Ward C. Jose 
Published: May 2005

AbstractWavelength‐dispersive X‐RAY SPECTROMETRY can be used to great advantage for the rapid monitoring of the composition of tin‐lead solders. However, account must be taken of some metallurgical properties that influence the X‐ray analysis, viz. the development of concentration gradients during solidification and the process of ageing that sets in at room temperature. Only after these problems have been controlled can a reliable analytical procedure be set up. Standards can be prepared with common facilities and matrix effects are dealt with by simple correction models.
Analytic description of Si(Li) spectral lineshapes due to monoenergetic photons
Authors: Campbell J. L. , Perujo A. , Millman B. M. 
Published: May 2005

AbstractSpectra have been recorded from monochromatized Kα1, Kβ1 and Lα1 X‐rays in the 3—16 keV energy region incident on an Si(Li) detector. An analytic lineshape consisting of a Gaussian plus two Gaussian‐exponential convolutes fits these well, except at very low energy. The intensities and parameters of these tails are explored in the context of the processes responsible, and the behaviour of the shorter tail is compared with the predictions of a model calculation of Auger and photoelectron escape. The well behaved energy dependence of the tailing parameters improves the prospects for more accurate fitting of complex XRF, EPMA and PIXE spectra.
Assessment of the gaussian ϕ(ρz) curves in quantitative electron probe microanalysis without optimization of the parameters
Authors: Saá J. H. Tirira , Del Giorgio M. A. , Riveros J. A. 
Published: May 2005

AbstractA new expression for the parameter β of the ϕ(ρz) curves is developed and the calculated K intensity ratios are compared with the corresponding experimental K, compiled in previous publications. The results show a mean value for K/K of 1.003, a standard deviation of 4.8% and an asymmetry of 1.01 with respect to unity.
Thick target X‐ray yields from proton bombardment
Authors: Katsanos A. A. , Aravantinos A. , Kallithrakas‐Kontos N. 
Published: May 2005

AbstractThe production yields for characteristic x‐rays from the bombardment of thick targets by protons are calculated by integrating the x‐ray production cross‐section for each element for the whole range of the protons, taking into account the self‐absorption of x‐rays. A simple approximation which can be applied with a pocket calculator is also presented, using simplified relationships for the energy dependence of the proton stopping power and the x‐ray production cross‐sections. The approximation allows very fast calculations, has an accuracy of better than 5% for low‐energy protons and is also very useful for the first steps in a computer program for PIXE analysis of thick targets, using the method of iterations. The calculated yields are compared with experimental results obtained on thick specimens of pure elements, compounds and standards.
Investigations towards optimizing EDS analysis by the Cliff‐Lorimer method in scanning transmission electron microscopy
Authors: Hoeft H. , Schwaab P. 
Published: May 2005

AbstractThe critical specimen thickness up to which the Cliff‐Lorimer method can be used without additional corrections was measured on some steels and nickel‐base alloys for soft x‐rays with line energies between 1 and 3 keV. The critical thickness values measured are 50 nm at 1 keV and 450 to 500 nm at 3 keV. These results indicated that verification of the calibration measurements used for determining the correction factors was necessary in the case of soft radiation. The measurements led to a further optimization of the parameters in the equation used for calculating the ionization cross‐sectionThe published equations for absorption correction, which becomes necessary when the critical specimen thickness is exceeded, were found to lead to an overcorrection in the case of very thin foils and an insufficient correction in the case of thicker specimens. However, it is only of significance if the specimens are very thick or errors less than 5% are aimed for.
Determination of X‐ray fluorescence sample geometry from compton backscatter energy
Authors: Nielson Kirk K. , Rogers Vern C. , Shuman Rob 
Published: May 2005

AbstractA method was developed to determine automatically sample positions and correct peak intensities for sample positional variations in x‐ray fluorescence (XRF) analysis. Small shifts in Compton backscatter peak energy are accurately measured in the spectrum and used to compute the mean scatter angle, from which the effective scatter position is determined. New equations were derived to express fluorescent and scatter positions within samples, and to correct peak intensities for geometry variations in a sample of arbitrary thickness, position and composition. The method was validated with an energy‐dispersive XRF system with secondary excitation. With thin samples, the method corrected intensity errors of up to 69% to within 2%, and with samples of intermediate thickness it corrected errors of up to 83% to within 1.7%. The method is important in quantitative fundamental parameter calculations, such as the CEMAS method, which otherwise define the sample to lie in a pre‐determined plane.
Quantitative X‐ray fluorescence analysis of specimens with rough surfaces: Monte Carlo approach
Authors: Ebel H. , Poehn Ch. 
Published: May 2005

AbstractIn general, the application of the fundamental parameter method in quantitative x‐ray fluorescence analysis is restricted to specimens with plane and smooth surfaces. For such surfaces, the correlation of path lengths x of incident tube photons and y of escaping fluorescent photons is well defined. For rough surfaces this correlation is described by distribution functions. Thus, for x1 ≤ x ≤ x2 a probability density Ø(y)x1, x2 allows the probability of y values to be described within the range yA ≤ y ≤ yB. From the results it is now possible to describe probability distributions of rough surfaces by means of Monte Carlo calculations.
Analysis of metallic shred: A basic experiment
Authors: Mantler M. , Taut T. 
Published: May 2005

AbstractMetallic shred obtained by turning bulk copper, brass and steel was embedded in resin and count rates were measured from these specimens and from the original bulk material. The specimens were then sliced into 0.5 mm thick sheets parallel to the plane of the x‐ray beams and the distribution of the metal within each cut was mapped by an optical scanner. Fundamental parameter calculations were applied to compute the count rates from the shred specimens pixel by pixel according to the map and also the count rate ratios relative to the bulk material of the same composition. Whereas count rates between different measurement positions may vary by more than an order of magnitude owing to the statistical distribution of the metal grains, the computed values agree to within (typically) 10% (relative) with the experimental data from matching specimen areas.
Application of X‐ray fluorescence spectrometry to the analysis of geochemical prospecting samples in China
Authors: Ma Guangzu , Li Guohui 
Published: May 2005

AbstractThe application of x‐ray fluorescence analysis to multi‐element determination in geochemical prospecting samples has been discussed in this paper. It consists of seven parts: introduction; sample preparation; instrument and analytical conditions; standardization and standardized sample; matrix effect correction; correction of spectral overlap; and conclusion.
Determination of Y, Zr, Ba, La and Ce in granitic rocks using energy‐dispersive X‐ray fluorescence
Authors: Lodha G. S. , Sawhney K. J. S. , Choubey V. M. 
Published: May 2005

AbstractHigh atomic number trace elements in granitic rocks were determined using an EDXRF spectrometer. The K series x‐rays of these elements were excited using 59.6‐keV gamma rays from 241Am. Minimal sample preparation is required and quantitative determination was achieved using a single geological standard.
A low dilution fusion technique for the analysis of geological samples 1—method and trace element analysis
Authors: Eastell J. , Willis J. P. 
Published: May 2005

AbstractA low dilution fusion (LDF) technique using a 2:1 flux‐to‐sample ratio has been developed for the accurate determination of major, minor and trace elements in rock samples by wavelength‐dispersive x‐ray fluorescence spectrometry (XRFS). The choice of flux, oxidant and the dilution ratio and the application to trace element analysis are discussed. The elimination of particle size effects in the homogeneous glass fusion discs is a major advantage over the use of powder pellets, especially for the determination of elements such as Ba, Cr and the REEs. The fusion technique ensures complete loss of volatiles from the rock samples and provides an accurate estimation of loss on fusion values. The oxidation and retention of sulphur in the discs were also investigated. Instrumental conditions, including corrections for spectral line interferences, are reported for 20 trace elements. The average relative error for the trace elements commonly analysed in rock samples was less than 5% and there was a decrease in sensitivity by about a factor of 2 compared with XRFS determinations on powder pellets. The LDF method has been used for the analysis of geological samples of widely varying and unusual composition, such as lamproites and kimberlites, but is also suitable as a general‐purpose sample preparation technique.
New horizons in x‐ray fluorescence analysis
Authors: Gilfrich John V. 
Published: May 2005

AbstractAlthough the present‐day x‐ray analyst has at his or her disposal a sufficient variety of instrumentation and data reduction schemes to enable him or her to perform elemental analysis on many different types of materials, there exists a continuing demand to improve detection limits, to extend the capability to lower atomic numbers and to make the analytical process more efficient (easier!). There are advances in x‐ray physics and instrumentation being pursued which may contribute to these objectives. The status of these efforts is reviewed and some suggestions are made concerning their potential.
Combined energy‐dispersive–wavelength‐dispersive quantitative electron microprobe analysis
Authors: Ware N. G. 
Published: May 2005

AbstractAn empirical study of the precision of measurement by energy‐dispersive (EDS) and wavelength‐dispersive (WDS) techniques is described. Combined EDS–WDS quantitative analysis provides efficient instrument operation, optimum precision in major element analysis and the best limits of detection in trace element analysis. A software package for a combination EDS–WDS electron microprobe is described.
Study of the effect of sample, loading heterogeneity in the energy‐dispersive x‐ray fluorescence analysis of specimens of intermediate thickness
Authors: Markowicz Andrzej , Abdunnabi Ashur A. 
Published: May 2005

AbstractThe influence of the effect of sample loading heterogeneity on the accuracy of the emission–transmission technique applied in the x‐ray fluorescence analysis of specimens of intermediate thickness was studied. Various types of sample loading heterogeneities, including incompletely loaded samples, were considered. General expressions describing the accuracy of the emission–transmission method within a wide range of sample thicknesses and characteristic x‐ray energies were derived. Experiments for the verification of the theoretical predictions were also carried out for some selected test samples of known sample loading inhomogeneity.
Calculation of depth distribution functions for characteristic x‐radiation using an electron scattering model. I—theory
Authors: August Hans‐Jürgen , Wernisch Johann 
Published: May 2005

AbstractThe depth distribution function for characteristic x‐radiation is calculated using a simple electron scattering model, which quantifies the amount of electrons being scattered back and forth in the sample. The quantities used for the calculation are the transmission and backscattering coefficients, the corresponding energy and angular distributions and the ionization cross‐section. The physical background and implications of this model are discussed.
Application of x‐ray fluorescence spectrometry in process control in sinter plants
Authors: Subrahmanyam V. V. V. , Krishnaiah K. S. R. , Srivastava Y. P. 
Published: May 2005

AbstractThe importance of the analysis of the green mix in the operation of sinter plants in integrated steel plants is described. The application of XRF in process control of sinter plants was investigated. The results suggest the replacement of time‐consuming wet chemical methods by a combination of XRF and IR absorption techniques.
Multi‐element trace analysis of rocks and soils by EDXRF using polarized radiation
Authors: Heckel J. , Brumme M. , Weinert A. , Irmer K. 
Published: May 2005

AbstractAn XRF device using polarized x‐rays for trace element analysis of rocks and soils has been developed. During a measuring time of 1000 s (two single measurements of 750 and 250 s, respectively), 36 elements with atomic numbers 22 ≤ Z ≤ 92 and detection limits between 15 and 0.3 ppm can be determined with high precision. The ratio between the net counts from a characteristic line of the element being determined and the number of background counts caused mainly by Compton scattering is used for the matrix correction procedure. Absorption and enhancement effects by major sample element concentrations are taken into account. Good agreement was found between analytical results and certified values for standard reference materials.
Beam profile studies in an x‐ray fluorescence spectrometer
Authors: Boman J. , Standzenieks P. , Selin E. 
Published: May 2005

AbstractFor small samples, the beam intensity in a secondary target conventional x‐ray fluorescence (XRF) spectrometer is often not sufficient. As a step in our efforts to optimize the three‐axial XRF spectrometer in Gothenburg, the intensity profile of the x‐ray beam from the secondary target was studied. The intensity profile was found to be inhomogeneous. For the beam profile studies, mechanical systems were built which can also be used for position determination of small samples. A movable platform for the detector was constructed and equipped with driving and controlling electronics. To improve further the flexibility of the spectrometer, the sample holder was rebuilt to allow for movements of the sample in the x‐, y‐ and z‐directions. The possibility of tilting the sample and thus varying the angle between the incoming beam and the sample plane from about 0 to 90° was included in the mechanics of the sample holder. The arrangement can also be used to centre the samples in the spectrometer and to move the sample for analysis of different parts of the sample.