bluuebunny/crossref_metadata_2025_split huggingface dataset:
The shape of the continuous X‐ray spectrum and background corrections for energy‐dispersive electron microprobe analysis
Authors: Reed S. J. B. 
Published: May 2005

AbstractThe shape of the continuous spectrum between 0.5 and 10 keV generated by 10 to 25 keV electrons has been calculated. It is shown that Kramers' law underestimates the intensity generated at low X‐ray energies. However, this is partially compensated by the greater absorption suffered by continuum X‐rays compared with characteristic X‐rays, which is demonstrated by comparing the depth distributions derived from Monte‐Carlo calculations. Refinement of the background correction in energy‐dispersive microprobe analysis in the light of these results is desirable, though for most purposes the method based on Kramers' law corrected for absorption by the conventional means used for characteristic radiation is adequate.
Application of the method of variable take‐off angle to rapid quantitative XRFA with energy dispersive systems
Authors: Ebel H. , Drabseh S. 
Published: May 2005

AbstractOne way carrying out quantitative X‐ray fluorescence analysis with fundamental parameters is the method of variable take‐off angle. At angles nearly parallel to the sample surface, the equations can be solved more easily and no knowledge of the white spectrum and μ(λ) is needed. For practical application, in order to get a well defined geometry, we used a diffraction goniometer, an X‐ray tube with Mo target and an energy dispersive detector, followed by a multichannel analyser. After calibrating the system, all information essential for a quantitative analysis was obtained from a single measurement. The validity of the final equations was verified by experiments with different alloys, consisting of two, three and four components.
X‐ray fluorescence analysis of corrosion products of steel
Authors: Blomqvist P. O. 
Published: May 2005

AbstractAn X‐ray method for the analysis of thin oxide films on steels has been developed. The oxide layer is first stripped off by the action of bromine in methanol in an inert atmosphere. It is then dissolved and a small amount of the solution is allowd to evaporate on a filter paper impregnated with disodium carbonate. The matrix effects are thus negligible, which can be seen from the standard curves obtained from synthetic oxides in this way. From the standard curves the precision has been estimated to be about ± 5%. The method has been used to analyse oxide layers formed on four different steels oxidized at high temperatures.
Chemical state analysis of vanadium by high resolution X‐ray spectroscopy
Authors: Gohshi Y. , Nakamura T. , Yoshimura M. 
Published: May 2005

AbstractThe chemical shift of V Kβ1, 3 and width of V Kα1 were measured with a two crystal X‐Ray spectrometer. It was found that V Kβ1, 3 shift and V Kα1width can be utilized for identification of the vanadium oxidation state. Applications to vanadium containing catalysts and several perovskite structure compounds are discussed.
Emission de rayonnement X par suite de bombardement de protons
Authors: Bodart F. , Wilk S. , Deconninck G. 
Published: May 2005

AbstractLes sections efficaces de production de rayonnement X émis par suite de bombardement de protons de moyenne énergie (0,4 à 2,3 MeV) sont mesurées avec un détecteur Si(Li) à haute résolution. La séries des corps suivants a été étudiée: Ti, V, Cr, Mn, Fe, Co, Ni, Cu. Les courbes d'ionisation sont déduites et le résultat est comparé avec des calculs obtenus à partir du modèle théorique de l'approximation de Born par ondes planes et du modèle semi‐classique. La comparasion fait apparaître la faiblesse des deux modèles dans cette région d'énergie. Des écarts importants apparaissent entre les rapports d'intensité Kα et Kβ provenant de différentes sources.
Calcul théorique des effets interéléments dans le cas des éléments légers. Influence de la dilution
Authors: le Sage R. Vié 
Published: May 2005

AbstractNous avons calculé les effets interéléments (absorption, renforcement et effets croisés) pour les mélanges d'oxydes des éléments Ti, Ca, K, S, P, Si, Al, Mg et Na en supposant une excitation monochromatique due à la radiation CrKα, et nous avons établi un parallèle entre (1) les mélanges compacts et (2) les solutions solides des mêmes oxydes dissous dans les fondants usuels, B4O7Li2 et B4O7Na2. On constate que les effets mutuels sont tres prononcés dans le premier cas, étant tout à fait comparables à ceux connus pour les alliages métalliques, tandis qu'ils sont plus ou moins atténués, comme on s'y attend, pour les systèmes dilués correspondants. On décrit le mecanisme de cette atténuation, de même que les simplifications apportées sur le plan des corrections matricielles.
Quantitative X‐ray energy dispersive analysis with the transmission electron microscope
Authors: Geiss R. H. , Huang T. C. 
Published: May 2005

AbstractA Comprehensive study of the interfacing of an X‐ray energy dispersive spectrometer to a transmission electron microscope is presented. Optimum detector location, sample tilt, collimation and accelerating voltage are discussed. Quantitative elemental analysis is obtained for thin film specimens using corrections for spectrometer response, absorption and background. Peak spectra are sorted using a method of profile fitting based on nonlinear simplex minimization. Using a simple analysis scheme, the peak data is reduced to elemental composition with an accuracy and precision on the order of 1%. Examples from Fe–Ni and Ho–Co alloys are given.
Über die Röntgenfluoreszenzanalyse von Aerosol‐Präparaten
Authors: Eberspächer H. , Schreiber H. 
Published: May 2005

AbstractZwei bei der Röntgenfluoreszenzanalyse von Aerosol‐präparaten auftretende Probleme werden behandelt: (1) eine einfache und genaue Methode zur Herstellung von Eichpräparaten. Es wird vorgeschlagen, definierte Lösungstropfen in einem exakten Punktmuster auf Filterpapier aufzubringen. (2) Die Korrektur der Streu‐ und Absorptionseffekte des Filters und der abgeschiedenen Schwebstoffe. Die aus Messungen in Einfach‐ und Dreifach‐Filterpaketen gewinnbaren Korrekturterme werden am Beispiel des erfahrungsgemäß kritischen Elements Calzium dargestellt.
Calibration and use of a lithium‐drifted silicon detector for accurate analysis of X‐ray spectra
Authors: Keith H. D. , Loomis T. C. 
Published: May 2005

AbstractA detailed study of the performance of a silicon detector system is reported, with emphasis on the feasibility of using such a system for accurate quantitative analysis of X‐ray spectra covering a wide range of photon energies (2.5‐50 ke V). Calibration of efficiency, with an accuracy of ± 0.1% over most of this range, is described. Second order effects in the detection system have been characterized quantitatively, including escape peaks, pulses due to Compton recoil electrons, pulses whose energies are reduced because of incomplete charge collection and sum pulses. This information has been used to devise programs that permit accurate correction of spectra as recorded in a multi‐channel analyzer. Corrections are made for the following factors in turn; sum pulses, the second order effects enumerated above and detector efficiency. An analysis of the formation and distribution of sum pulses that represent close coincidences not resolved and eliminated by the pulse pile‐up rejector is given in an Appendix. Methods are described for removing sum counts, including ‘mixed’ sum counts, from spectra. The removal of these counts reduces the overall count but results in essentially undistorted representations of spectra as they would be recorded in a system having infinitesimal dead‐time. Some recommendations are made for improving the design of silicon detectors for quantitative spectral analysis.
A simple dead‐time correction for X‐ray counting systems
Authors: Hutchison Charles S. 
Published: May 2005

AbstractThe dead time (t) of an X‐ray counting system may be readily determined to the nearest 0.4 μs by accurately measuring the counting rate per second (R) for any selected wavelength on two specimens, whose R values differ by a factor of approximately 10, at several tube or specimen currents. The R of the most intense specimen should cover the range up to 6 × 104 counts per second.

where a and b are the R values of the two specimens at one current, and a1 and b1 the R values of the same specimens at another. The average t is determined from as many current pairs as possible. All counting rates (R) are thereafter corrected by the equation

where R0 is the true and R the measured rates per second. R should not exceed about 6 × 104.For energy‐dispersive detectors, the R values of Kα and Kβ peaks may be used from a single specimen and substituted for a and b in the above equation to obtain t.
Plant analyses by X‐ray spectrometry I—Low atomic number elements, sodium to calcium
Authors: Norrish K. , Hutton J. T. 
Published: May 2005

AbstractPlants can be analysed for the elements sodium, magnesium, aluminium, silicon, phosphorus, sulphur, chlorine, potassium and calcium by X‐ray fluorescent spectrometry using discs pressed directly from dried and ground plant material. Fine grinding is essential to avoid particle size effects and the finely ground samples are self supporting when pressed.Tables are given to correct for variations in absorption by the samples due to compositional changes, and also to correct for crystal fluorescence or scatter so that background measurements are not necessary on each sample.Calibration has been made using chemicals added to cellulose and the results obtained on a series of samples agree (essentially within one standard deviation) with the mean values obtained by other methods. Results are also given for the standard kale sample.
The application of a ‘curve‐fitting computer program’ to compensate for inter‐element effects in X‐ray fluorescence analysis of rock samples. The determination of vanadium in geological standards
Authors: Riddle Chris , Smith T. E. 
Published: May 2005

AbstractA computer program, used to ‘curve‐fit’ complex spectra of overlapping peaks in other spectral applications, has been used with X‐ray fluorescence data. Compensation is made for analytical error introduced through peak overlap. A typical case of this ‘inter‐element interference’, that of titanium upon vanadium, is taken to demonstrate the method. A comparison between the computer‐generated results and those determined by the conventional inter‐element correction method favours the curve‐fitting procedure.
Mise au Point du Dosage du Brome dans le Plasma et la Sueur à l'aide d'un Spectromètre à Fluorescence X à Source Isotopique Annulaire de Cadmium‐109
Authors: Barbier Y. , Pehlivanian E. , Girard C. 
Published: May 2005

AbstractIl peut être intkréssant de doser le brome dans certains liquides biologiques. La présence d'autres éléments limite le choix des méthodes. L'analyse par spectrométric de fluorescence X paraít adaptée sous certaines conditions. Les auteurs décrivent une technique utilisant un spectromètre de fluorescence X non dispersif, dont la source d'excitation est constituée par un isotope radioactif: le Cadmium 109. Les facteurs de géométrie, le volume des échantillons, Ie choix des cellules, la reproductibilité des mesures sont étudiés, compte tenu des conditions imposées par le recueil des échantillons biologiques.
Accuracy of X‐ray fluorescence spectrometric determination of Rb and Sr concentrations in rock samples
Authors: Th. Verdurmen E. A. 
Published: May 2005

AbstractIt is shown that application of the Compton scattering method for matrix correction in the X‐ray fluorescence spectrometric determination of the trace elements Rb and Sr in rock samples can provide concentrations at a relative accuracy level of 1%. The empirical method applies to rock samples showing differences in mass absorption up to a factor of two. The accuracy of the method has been tested by analysis of 57 samples analysed for Rb and Sr by mass spectrometric isotope dilution. In addition a few of the U.S. Geological Survey (U.S.G.S.) reference rock powders, showing significantly different mass absorption, were analysed for Rb and Sr. It is demonstrated that the mica effect, if significant, is smaller than 1% relative. There is no advantage in the use of the LiF(220) analysing crystal as a substitute for the LiF(200). The method appears to be insensitive to the pellet thickness.
Crossed influence coefficients for accurate X‐ray fluorescence analysis of multicomponent systems
Authors: Tertian R. , Vié Le Sage R. 
Published: May 2005

AbstractA thorough theoretical study of the typical iron–nickel–chromium ternary system confirms the essential variability of influence coefficients with composition, thus accounting for the limited validity of empirical coefficient procedures. The origin and mechanisms of coefficient variation are accurately described, namely by distinguishing between binary or ‘longitudinal’ variation, it being related to either an enhancement effect or the use of polychromatic excitation or possibly both, and ‘transverse’ variations resulting from fluorescence crossed effects as well as tertiary fluorescence if represented. As a consequence a general mathematical expression, including all these effects and exactly matching the theoretical intensity equations, is assigned to the coefficients for the entire range of compositions. On a practical basis, precision considerations allow to simplify these relationships considerably and reduce them to a fairly simple, flexible system of ‘crossed’ influence coefficients. Since it closely conforms to the fundamental principles of fluorescent emission, this new scheme should prove effective for determining multicomponent systems, namely by allowing accurate analysis to be performed over a wide range of compositions ‘without standards’.
X‐ray fluorescence analysis of catalytic converters using single‐element standards and theoretical corrections for interelement effects
Authors: Artz Bruce E. 
Published: May 2005

AbstractAn X‐ray fluorescence technique for the quantitative analysis of phosphorus, sulfur, chromium, iron, nickel, copper, zinc, zirconium, ruthenium, rhodium, palladium, barium, lanthanum, cerium, iridium, platinum and lead on fresh and used catalytic converters is described. The method used is to correct the measured X‐ray intensities of each element using theoretically calculated interelement absorption and enhancement effects so that they may be compared to X‐ray intensities measured on single element standards. The elemental concentrations are obtained from intensity calibration curves derived from the known compositions of the standards.
A procedure to increase signal in X‐ray spectrometry
Authors: Mathieson A. McL. 
Published: May 2005

AbstractUse of an asymmetrically‐cut single crystal whose surface is polished optically flat can yield a considerable gain in signal over that available in the conventional symmetrical disposition in cases where high resolving power is not critical. Adjustment of the level of asymmetry is achieved simply by rotation of the wedgeshaped crystal about the perpendicular to the Bragg plane used.
Experimental spectral distribution versus Kramers' law for quantitative X‐ray fluorescence by the fundamental parameters method
Authors: Laguitton Daniel , Parrish William 
Published: May 2005

AbstractQuantitative X‐ray fluorescence analysis by the fundamental parameters method and the LAMA Program shows that the experimentally determined spectral distribution leads to accurate results whereas the continuous spectrum calculated from Kramers' Law often leads to relatively large errors. The primary characteristic line spectrum of a W tube at 45 kV may cause most of the fluorescent intensity, e.g. nearly all the Ni K and about 60% of Cr K.
Total X‐ray fluorescence analysis of geological samples using a low‐dilution lithium metaborate fusion method. Matrix corrections for major elements
Authors: Haukka M. T. , Thomas I. L. 
Published: May 2005

AbstractA low‐dilution fusion method (1:2, sample to lithium metaborate) has been investigated for the determination of ten major elements in geological samples and the results are shown to have an accuracy comparable to those obtained using the well‐known heavy‐absorber method. Experimental determination of matrix coefficients employed natural rock standards (alone, mixed or spiked with synthetic oxides), and synthetic oxide mixtures covering a broad range of compositions of the ten most naturally‐abundant oxides. The method of determining the correction coefficients is described. Flexibility of sample preparation is a feature. Experiments with varying dilution ratio (from 1:1 to 1:15, granodiorite to flux) show that the same set of correction parameters can be used throughout the range. This is practically important for samples with large ignition losses or gains and in certain other applications. Systematic differences between calculated mass absorption coefficients and the experimentally‐derived correction parameters are documented and can be used in predicting parameters for additional elements. The greatest potential benefit of the low‐dilution method is in automated analysis of geological and industrial samples (rocks and soils, ores and bauxites, slags, glasses, cements, refractories) for major and trace elements using only one glass disc.
X‐ray K emission spectra of vanadium in various oxidation states
Authors: Yasuda S. , Kakiyama H. 
Published: May 2005

AbstractThe Kα1,2, Kβ1,3, Kβ5, and Kβ″ emission spectra of vanadium in the element and several V (III), V(IV), and V(V) compounds have been measured with a two‐crystal X‐ray spectrometer. The Kα1 and Kβ1,3 peaks shift slightly to lower energies with increasing lthe oxidation state of vanadium atom and the Kβ5 peak shifts to higher with it. An approximately linear relationship between Kα1 width and Kα1/Kα2 intensity ratio can be used for lindentification of vanadium oxidation state.
A critical investigation of energy‐dispersive microprobe analysis of steel using the Reed/Fiori method of background calculation
Authors: Comins N. R. , Thirlwall J. T. 
Published: May 2005

AbstractPublished investigations of the energy‐dispersive microprobe analysis of stainless steel repeated using the Reed/Fiori method of calculating the background intensity distribution. It is shown that the ‘interference effect’ in Kβ/Kα intensity ratios for elements in steels, which arose from studies using the Fourier transformation and frequency filtered background subtraction method, is due to deficiencies in this method. The systematically negative errors in analyses of Ni in steel are studied and can be corrected by using the Reed/Fiori method.
Electron probe microanalysis applied to very thin layers of aluminium‐nickel alloys
Authors: Dužević D. , Bonefačić A. 
Published: May 2005

AbstractIn order to determine the composition of very thin homogeneous layers of multi‐component systems, a reinterpretation of G. A. Hutchins' Method for elemental metal films was worked out. This made it theoritically possible to calibrate for the composition of complex n‐component fims by using massive standards of pure constituents as is done in the case of bulk samples. The method was supplied to very thin layers of AlNi alloys and the results are compared with those obtained by means of emission X‐ray spectrometry.
A comparison of the transmission properties of 1 μm and 6 μm polypropylene flow counter windows
Authors: Seaman A. 
Published: May 2005

AbstractOver recent years, some confusion has arisen regarding the transmission properties of commercially available frame‐mounted polypropylen flow counter windows compared to those of the loose sheet polyethylene teraphthalate (Mylar) material previously available. Experimental results obtained for Ca to F Kα characteristic radiations inclusive enable the transmissions of 6 μm Mylar 1 μm polypropylene to be calculated which in turn are compared to earlier published data.
Determination without standards of small amounts of metal compounds on microfilters by X‐ray fluorescence spectrometry
Authors: Ohno Katsumi , Fujiwara Jun , Morimoto Ichiro 
Published: May 2005

AbstractThe extracted minor phases in superalloys are analyzed by X‐ray fluorescence spectrometry without the use of standards. The calculation in the analysis is simplified by using a monochromatic X‐ray source and the fundamental parameter method. The extracts on the microfilter are approximated by thin film on the filter substrate, though the extracts were not homogeneous. This source permits a simple calculation using the thin film model to transform the measured X‐ray intensity to mass thickness and mass fraction, since the mass absorption coefficient for the primary beam is easily found in a commercially available table. A great advantage of this method is that the calculations are possible by using a small programmable calculator.
A technique for the analysis of odd‐shaped samples by means of X‐ray fluorescence spectrometry
Authors: Wybenga F. T. 
Published: May 2005

AbstractOdd‐shaped pieces of material were analysed by first setting them in a thermoplastic resin containing copper or iron powder. In subsequent measurements the copper or iron was used as monitor to correct the measurements on the sample. Corrections for coincidence losses of counts were found to be very important when applying this method.
X‐Ray secondary fluorescence in matrix correction
Authors: Plesch R. 
Published: May 2005

AbstractRasberry and Heinrich1 have proposed a mathematical statement for the correction of secondary excitation based on experimental observation. It will be shown that the mathematical form of this statement can also be confirmed physically. With regard to the coefficients, suggestions will be made which should provide a greater, general validity of the statement. Finally, the statement will also be extended to analytical problems in which the intensity of the matrix elements will be used for matrix correction, instead of their concentrations.
Element mapping by a scanning X‐ray system
Authors: Gurker N. 
Published: May 2005

AbstractPhysical surface analysis methods using charged particles on the excitation side can easily be applied to elemental distribution mapping. One common feature of all known methods is that they work on a micron scale, with respect to spatial resolution and investigated sample area. This paper deals with a new approach to the problem of element mapping using X‐ray fluorescence radiation. In contrast to the well‐known scanning procedures, this method allows the investigation of larger areas (several square centimetres) at lower spatial resolutions (≳ 100 μ). The method applies a mechanical scanning device, a modern energy‐dispersive detector and a computer. The scanning unit allows translation and rotation movements of the sample. By generating a line‐shaped X‐ray beam and translating the sample across the fixed X‐ray strip while measuring the intensity of the fluorescence radiation in a specified energy window, one obtains a strip resolution of the species investigated. If many translation measurements are made under different angular orientations of the sample, a computer converts the strip resolutions of the scanning profiles into a point resolution of the specified element. The mathematical background is known in the literature as ‘representation of a function by its line integrals’ or ‘image reconstruction from projections’. Computer simulation studies and experimental results will be discussed.