bluuebunny/crossref_metadata_2025_split huggingface dataset:
A focusing X‐ray polarizer for energy‐dispersive analysis
Authors: Ong Poen S. , Randall John N. 
Published: May 2005

AbstractThe Properties of diffracting crystals a Bragg and of near 45° are studied for use as an X‐ray polarizer. Such crystals have many advantages over the Barkla type polarizer when used in an energy‐dispersive X‐ray analyzer. The study shows that many matching λ‐d combinations are available, but the present work was done with LiF (200). With this crystal, the second order diffraction of Cu Kβ radiation occurs at 43.67° and an improvement of peak to background ratio by a factor 45 was obtained. The study revealed that a substantial improvement of peak to minimum detection limit can be obtained with a larger deviation of the polarization angle, as long as this deviation is accompanied by a higher X‐ray output.
A fast and simple procedure for the evaluation of net intensities from energy‐dispersive X‐ray spectra
Authors: Ekelund S. , Thurén A. , Werlefors T. 
Published: May 2005

AbstractA procedure has been developed for extracting net peak intensities from electron‐beam‐induced energy‐dispersive X‐ray spectra. The procedure has been implemented in a computer program which requires very modest storage capacity of a minicomputer, yet can be executed in a few seconds to yield net intensities. The program structure is simple. Provided the peak to background ratio is better than ∼5 to 1 the intensities are adequate for correction to quantitative analysis with accuracies comparable with more sophisticated and time‐consuming methods. The procedure has been used extensively on a computer‐controlled scanning electron microscope to give rapid information from complicated spectra.
Loss of sulphur during irradiation of X‐ray spectrometric standards prepared using cellulose and poly(vinyl alcohol)
Authors: King R. T. 
Published: May 2005

AbstractA loss of sulphur Kα intensity was observed during irradiation of pellets containing some sulphur compounds in organic binders. For elemental sulphur and dibenzyl disulphide mixed with either cellulose or poly(vinyl alcohol), the loss of intensity is attributed to loss of sulphur following reaction with hydrogen produced by radiolysis of the organic binder. No such loss is observed from potassium aluminium sulphate in either binder. The rate of loss of sulphur per unit of energy absorbed by the sample accords with published values for hydrogen production by radiolysis of carbohydrates and alcohols.
Response functions for the quantitative evaluation of compromise conditions for multi‐element analyses with energy‐dispersive X‐ray fluorescence spectrometry
Authors: Wegscheider Wolfhard , Jablonski Bruce B. , Leyden Donald E. 
Published: May 2005

AbstractFigures‐of‐merit are developed for simultaneous multi‐element analysis with energy‐dispersive X‐ray fluorescence spectrometry. Those derived from information theory frequently give optima in regions of poor excitation of one or more elements and have to be restricted to the region above the absorption edge of the highest Z element; the shapes of the surface described by these and other functions are studied and their optima are compared. A product sum function of inverse Poisson standard deviation gives results that best meet the expectations of X‐ray spectroscopists. The location of optima in the space of excitation conditions is dependent upon concentration, but the optimum of the one sample of a batch with the highest overall count rate is still a good compromise between the best experimental conditions and maximum input. These results are substantiated with plots giving the dependence of the figures‐of‐merit from experimental conditions and with spectra at the optima as defined by the different functions. These equations are potentially useful as objective functions in optimization alogorithms as well as for the comparison between the performance of different X‐ray systems.
Totalreflexions‐Röntgenfluoreszenzanalyse
Authors: Wobrauschek P. , Aiginger H. 
Published: May 2005

AbstractEnergiedispersive Röntgenfluoreszenzanalyse ermöglicht die rasche und gleichzeitige Bestimmung verschiedener Elemente in einer Probe. Die bei Winkeln von einigen Minuten auftretende Totalreflexion von Röntgenstrahlen an der polierten Oberfläche eines Probenträgers, z.B. Quarzglas, und eine spezielle Geometrie‐Primärstrahl‐Probe‐Detektor wird dazu verwendet, um den durch klassische und Compton‐Streuung hervorgerufenen Hintergrund zu senken. Dadurch konnten Nachweisgrenzen für Elemente mittlerer Ordnungszahl im Nanogrammbereich erzielt werden. Tritt Totalreflexion von Röntgenstrahlen auf, so dringen diese nur in einer Tiefe von etwa 40–70 nm in den Probenträger ein und bestimmen dadurch die effektive Dicke. Man verbindet daher mechanische Festigkeit, chemische Widerstandsfähigkeit und beliebige Dimensionierung des Probenträgers mit den für geringen Hintergrund günstigen Eigenschaften extrem dünner Folien. Standardmeßzeiten von 120s und ein Probenvolumen von 5 μl sind ausreichend, um Konzentrationen im ppm Bereich, d.h. Absolutmengen von Nanogramm mit RFA nachzuweisen.
X‐Ray fluorescence analysis in the X‐ray region of 0.4 to 7 nm: Application to determination of fluorine in slags
Authors: Sato Kimitaka , Tanaka Isamu , Otsuki Takashi 
Published: May 2005

AbstractX‐ray fluorescence analysis under high vacuum (∼10−6 torr) was applied to the determination of fluorine in slags. Slag samples are converted into glass beads using a fusion method and the fluorescent X‐ray intensity of characteristic X‐ray F Kα (1.83 nm) is measured to determine fluorine. The calibration curve has excellent linearity and accuracy; σd is 0.18% for 11 kinds of samples involving fluorine of 0.10% to 16.78% (mean: 6.96%).
Influence of divergence of the primary radiation beam on the line intensity of the X‐ray fluorescence spectrum
Authors: Pavlinsky G. V. , Kitov B. I. 
Published: May 2005

AbstractX‐ray fluorescence spectrum excitation theory is now well developed and uses the assumption that the primary X‐ray radiation beam is parallel. At the same time, in order to increase intensity it is necessary to keep the radiation source and fluorescence object as close as possible. In so doing the primary radiation divergence is found to be significant, and to ensure high accuracy of the intensity calculations it is necessary to evaluate the influence of this factor.Considerations are carried out for the cases of point, circular and line sources of primary radiation, selective effects being absent.The concept of the effective incidence angle is introduced which makes it possible to calculate X‐ray fluorescence intensities by formulae without correction for the primary radiation divergence. Values of the correction coefficients are given which correct for the dependence of the effective angle on chemical composition of the fluorescence material. The value of the effective incidence angle of primary radiation for a circular source is determined and compared with its theoretical value. Statistical treatment of the results shows insignificant differences between the experimental intensities and those calculated with correction for the primary radiation divergence when chemical composition variation of the material analysed is quite large.
Linear and non‐linear peak fitting in energy‐dispersive X‐ray fluorescence
Authors: Nullens H. , Van Espen P. , Adams F. 
Published: May 2005

AbstractLinear and non‐linear least‐squares fitting procedures are compared in their ability to resolve X‐ray fluorescence spectra obtained with Si(Li) detectors. It is shown, by repeated analysis of synthetic and real X‐ray spectra, that non‐linear least‐squares fitting programs which take into account the relation between peak positions and widths on the one hand and X‐ray energies on the other hand, and moreover impose limitations upon the fitting parameters, represent a definite advantage over the linear least‐squares fitting method. Only for spectrometers having an extremely high stability with time and counting rate does the linear fitting procedure yield accurate results.
Optimization of a spectrometer for energy‐dispersive X‐ray fluorescence analysis by X‐ray tubes in combination with secondary targets for multielement determination
Authors: Spatz R. , Lieser K. H. 
Published: May 2005

AbstractThe construction of a simple device for X‐ray fluorescence analysis by use of an X‐ray tube, secondary targets and filters is described. Optimal conditions and detection limits are determined experimentally by variation of the excitation parameters for each combination of secondary target and filter.
Determination of tungsten in ores, concentrates and plant process materials using internal standard X‐ray fluorescence spectrophotometry
Authors: Harris A. M. , Hingle D. N. 
Published: May 2005

AbstractA method is described for the X‐ray fluorescence determination of tungsten in non‐metallic samples over the range 0–100%. The sample is fused with (65% sodium, 35% lithium) tetraborate, barium nitrate and tantalum pentoxide, the internal standard, at 1200°C and the melt cast into a platinum/5% gold mould. After cooling the cast bead, the tungsten and tantalum Lα intensities are determined by X‐ray fluorescence. The tungsten content of the sample is found by comparing the measured intensity ratio with intensity ratios obtained from standards prepared using pure tungsten trioxide.A wide range of ores, concentrates and plant process materials are analysed for tungsten by this method. The accuracy and precision of the method, which is quicker and requires less skill from the analyst, are found to be superior to those of the classical gravimetric method.
An estimation of selected methods for the correction of interelement effects in X‐ray fluorescence analysis
Authors: Stankiewicz W. , Sanner G. 
Published: May 2005

AbstractThe comparison of the efficiency of the selected interelement effect correction methods was the aim of this paper. The experiments were carried out on the synthetic oxide samples containing 0–40% PbO2, 20–60% ZnO, 0–40% Fe2O3 and 0–30% SiO2. The existing strong interelement effects were evaluated by means of the Plesch criterion. In order to find the correction method giving the best results and at the same time being relatively simple for practical use the internal standard and several mathematical methods (de Jongh, Rasberry–Heinrich, Lucas‐Tooth–Pyne, and regression) were accurately investigated. The efficiency of the selected mathematical methods was characterized by the values of relative residual variance. None of the examined methods gives the best results for all elements simultaneously. The values of relative residual variance lie between 1% and 5%. The approximation by the Rasberry–Heinrich model gives the best average variance over all elements, but its practical use is very labour‐consuming. The simple form of the Lucas‐Tooth–Pyne and regression equations as well as the relatively simple calculations provide facilities for their application in laboratories not equipped with more sophisticated calculating systems. The internal standard method gives results which are comparable with those obtained by use of the mathematical methods tested.
X‐Ray production by 11‐27 MeV alpha particles
Authors: Bǎdicǎ T. , Ciortea C. , Petrovici A. , Popescu I. 
Published: May 2005

AbstractK X‐ray prodution cross‐sections for S, Cl, K, Ni, Cu, Ga, Br, Ag and Cs and total L X‐ray production cross‐sections for Cs, W and Pb using α‐particles of 11, 16, 21 and 27 MeV energy have been measured. The present results, combined with some earlier measurements, were compared with the theoretical predictions of the plane‐wave Born approximation (PWBA), binary encounter approximation (BEA) and perturbed stationary state (PSS) approximation.
Multielement x‐ray fluorescence spectrometry of solutions
Authors: Budesinsky B. W. 
Published: May 2005

AbstractThe theoretical relationships between fluorescence intensity and concentration have been used for the calculation of correction constants of the Lachance‐‐Traill and Rasberry‐‐Heinrich equation for systems of solutions. The constants have also been calculated by means of the multivariate least‐‐squares method. Those two alternatives have been tested on systems of Cu‐‐Fe‐‐Zn and Cu‐‐Fe‐‐Zn‐‐Pb in 3.5% aqueous nitric acid and compared with the simple two‐variable linear relationship between fluorescence intensity and concentration. The multivariate least‐‐squares alternative gives for the Lachance‐‐Traill method very accurate results (average relative deviation does not exceed 0.18%). In a theoretical discussion, the relationship between optimum sample concentration and solvent correction (enhancement) constant is shown. The optimum conditions for a background reading are also calculated.
A peak integration method for acquiring x‐ray data for on‐line microprobe analysis
Authors: Ferguson A. K. , Sewell D. K. B. 
Published: May 2005

AbstractThe operation of a computer system for producing on‐line chemical analyses from a three‐spectrometer JEOL JXA‐5A electron microprobe is briefly discussed. A new method for acquiring the X‐ray data by integrating the area under the peak is discussed in greater detail. The increased reliability of the results from this new method are illustrated by considering the effect of focus error on the measured count rates.
X‐ray diffractometry of airborne particulates deposited on membrane filters
Authors: O'Connor B. H. , Jaklevic J. M. 
Published: May 2005

AbstractMethods are considered for optimizing a conventional Bragg‐‐Brentano X‐ray powder diffractometer for the identification of crystalline phases in airborne particulates deposited on membrane filters. The instrumental parameters investigated include detector stepping increment and scan range, Kβ filtration, and the incident beam divergence slit width. Sample‐related factors such as substrate material (cellulose ester, polycarbonate and polytetrafluoroethylene), off‐axis displacement of the sample and X‐ray induced specimen degradation were also studied. Scan times for sample deposits of several hundred μcm−2 are in the vicinity of 24 h with an 800 W tube. These times may be reduced substantially by one or more of the following modifications: rotating anode or synchrotron radiation source, energy‐dispersive diffractometry, and Bragg‐‐Brentano diffractometry with a position‐sensitive gas detector.
Determination of the thickness of SiO2 layers on SI by X‐ray spectrometry
Authors: Ebel M. F. , Ebel H. , Wernisch J. 
Published: May 2005

AbstractThis paper shows the employment of five X‐ray methods for the investigation of a thickness range of 1 Å to 0.1 mm. The well known techniques (X‐ray fluorescence and scanning electron microscopy) are treated, a new method (energy‐dispersive X‐ray diffraction) is discussed and X‐ray photoelectron spectroscopy measurements are essentially improved by a new evaluation method. Low energy electron induced X‐ray spectrometry is mentioned. As far as significance of the measured thicknesses is concerned, the range of 10‐‐50 nm deserves special attention.
Automatic absorption correction in x‐ray fluorescence analysis of intermediate thickness samples using a dual external reference signal
Authors: Van Dyck P. , Markowicz A. , Van Grieken R. 
Published: May 2005

AbstractA method has been investigated which allows calculations from the X‐ray fluorescence spectra of the absorption coefficients at any energy for any sample, without any additional measurement. Use is made of the ratio of the characteristic X‐ray signals from a Zr wire positioned in front of the sample and from a Pd foil placed behind the sample, both in a fixed geometry. From the experimentally measured absorption coefficient at the Pd L energy (2.9 keV), the coefficients for higher energies are calculated. By the use of an iterative computer routine in which corrections for the enhancement of the Pd foil by the sample are also included, an accuracy of 2% or better on the absorption coefficient determination can be reached for homogenous samples in one measurement. Grain‐size and heterogeneity effects induce inaccuracies on the absorption coefficient determinations which might well reach 20% for particulate samples like intermediate thickness deposits of geological materials. This approach thus has the same limitations as the classical transmission method for such heterogeneous samples.
The derivation of influence coefficients from experimental and calculated XRF data
Authors: Chamberlain G. T. 
Published: May 2005

AbstractThe use of the multiple linear regression program for the derivation of influence coefficients destroys the data bank in the Philips PW 1450/10 spectrometer computer and interrupts analysis. Consideration of the basis of α‐coefficients as applied to relatively dilute solutions leads to methods of avoiding the use of this program. Linear regression involving a single independent variable and simple algebraic expressions can be used to derive the coefficients. The requirements for converting α‐coefficients applicable to one solvent for use in a different solvent are described.
Computer control of the electron probe microanalyser: The control system and some applications
Authors: Bishop H. E. , Poole D. M. 
Published: May 2005

AbstractThe ways in which the usefulness of the electron probe X‐ray microanalyser is extended by computer control and the demands imposed on the computer operating system by a general purpose electron probe are discussed. Three main modes of operation are identified and a flexible operating system to meet the main requirements for these modes is described. Examples of the use of the system are given with particular emphasis on two applications which could not be tackled easily with a manually operated system: composition surveys over large areas of the sample and digital mapping techniques.
A method for isotope‐excited X‐ray fluorescence analysis of thick samples
Authors: Datta S. , Sadasivan S. 
Published: May 2005

AbstractA simple equation relating the intensity of characteristic X‐ray lines to their respective weight fractions has been obtained for a thick sample excited by an isotopic source. It follows from the equation that a single intense line in a standard sample suffices to generate calibration constants over a wide range of elements. Validity of this aproach has been demonstrated by the analysis of a standard soil sample using only the Fe Kα line for calibration. A procedure for correction of peak overlaps has been given using the Kβ/Kα ratios, modified by the matrix effects. The method is very useful for the analysis of soil samples and can be conveniently applied to other matrices.
X‐ray fluorescence analysis without standards of small particles extracted from super‐alloys
Authors: Ohno Katsumi , Fujiwara Jun , Morimoto Ichiro 
Published: May 2005

AbstractSmall amounts of particulate matter electrochemically extrated from super‐alloys were accurately analysed by X‐ray fluorescence spectrometry with pure element bulk standards. The extracts are less than a few hundred micrograms per square centimeter and are not homogeneous. They are approximated by a thin film on a filter substrate. The penetration of the particulates into the membrane filter on which they are mounted is negligible and no absorption correction for the filter is required. The spectral distribution of the X‐ray source used in the calculation was obtained from Kramer's formula with self‐absorption correction for the continuum and from measurements of the characteristic line. The intensity‐concentration algorithm is based on the fundamental parameter method; the calculation is simplified because no matrix correction is required if the relative intensities are less than or equal to 0.04. The method gives excellent results in chemical analyses.
Multielement analysis of phytoplankton by tube‐excited energy‐dispersive X‐ray fluorescence
Authors: Pietiläinen K. , Adams F. , Nullens H. , Van Espen P. 
Published: May 2005

AbstractTube‐excited energy‐dispersive X‐ray fluorescence with Mo K and Ti K secondary target radiation proves to be a rapid, precise and accurate method for the multielement analysis of phytoplankton collected on membrane filters. Using 150–750 ml water samples it is possible to determine the concentration of 11–16 elements among the 22 elements which can be systematically searched for in the spectra. The study area is an estuarine water body on the Gulf of Finland and an archipelago outside the estuary.
Comparison of crystals for oxygen analysis
Authors: Barrus D. M. , Blake R. L. 
Published: May 2005

AbstractA comparison is made between five acid phthalates and clinochlore as analyzer crystals for oxygen Kα emission. Thallium acid phthalate (TAP) is shown to be superior for quantitative analysis because it has high reflectivity, relatively smaller corrections to reflectivity for anomalous dispersion, relatively low high order reflectivities and relatively low fluorescence background. The interplanar 2d spacing for TAP is 25.7626 ± 0.001 Å and its coefficent of thermal expansion α is 32.7 ± 1 K−1. At the oxygen Kα position its effective 2d spacing is 25.724 Å and the mean reflection coefficient is 2.8 × 10−4 rad. For analysis of chemical state, where higher resolution is often desired to distinguish band shapes and satellites, rubidium acid phthalate (RAP) is the best choice. It has α = 37.0±3 K−1, an effective 2d spacing of 26.083 Å and a mean reflection coefficient of 8.2 × 10−5 rad.
Standardization of the peak area ratios obtained from the analysis of small glass fragments using energy‐dispersive X‐ray fluorescence spectrometers
Authors: Howden C. R. , Dudley R. J. , Smalldon K. W. 
Published: May 2005

AbstractThe spectral sensitivities of different energy‐dispersive X‐ray fluorescence spectrometers may vary to the extent that the same glass fragment produces noticeably different spectra. In this study a set of twelve glass standards has been prepared. These are polished glass discs which span a wide range of elemental levels, and have been prepared for the monitoring and measurement of relative instrument sensitivies. The polished discs were analysed several times in rapid succession on one instrument and the mean elemental peak area ratios obtained were designated as standard values for these samples. During subsequent routine analytical work on this and other instruments, the discs are regularly analysed and if any significant changes are found the new elemental ratios can be corrected to the standard values usually simply by multiplying by a constant (the relative sensitivity factor). The procedure is shown to be effective in the case of 14 fragments of glass weighing between 40 and 1160 μg which were analysed several months apart on two different instruments.
A correction constant for rapid microprobe analysis of multicomponent metallic systems
Authors: Kale G. B. , Khera S. K. 
Published: May 2005

AbstractThe evaluation of the true chemical composition of multicomponent alloys by electron probe microanalyser requires the application of several correction factors, viz. atomic number, absorption and fluorescence corrections. Calculation of these factors is dependent upon a set of empirical correlations and needs the use of a computer. An alternative simple procedure of converting raw data into true composition using constants A is presented here. The paper describes the evaluation of these A constants, by rewriting the Ziebold–Ogilivie relation in the form: k/C = A + (1− A)k, and their use in computing true compositions.