bluuebunny/crossref_metadata_2025 huggingface dataset:
A practical method for the accurate analysis of high alloy steels by X‐ray emission
Authors: Caldwell Vincent E.
Published: May 2005

A method for the conversion of X‐ray intensities to composition is given. The method is based on the Lachance‐Traill equation which uses empirical inter‐element correction coefficients. The coefficients are treated as ‘sliding constants’ the values of which depend on the relative concentrations of the analyte and the interfering elements. Values for the coefficients are calculated over wide concentration ranges using the theoretical equations of Sherman. The calculated coefficients are adjusted empirically to achieve high accuracy.

Only the measured X‐ray intensities from the sample and a single standard are required for an analysis. Final results are obtained by solving a set of simultaneous linear equations. Results of analyses of high alloy steels containing Cr, Ni, Mn, Mo, Cu, Si, Ti, Cb and Fe are given to illustrate the accuracy of the method.
Folding of aerosol loaded filters during X‐ray fluorescence analysis
Authors: Van Grieken R. E. , Adams F. C.
Published: May 2005

Folding aerosol loaded filters in two with the loaded side inwards during the X‐ray analysis not only reduces possible filter heterogeneity effects and improves sample protection, but also increases the sensitivity and renders filter paper absorption corrections simple and more accurate in many instances. It is shown that folding an aerosol loaded Whatman filter paper during Kα X‐rays counting leads to an increased sensitivity for all elements up from calcium, scandium or titanium (depending on the sensitivity definition and on the aerosol load) and for all elements up from phosphorus, sulphur or chlorine in the case of the Nuclepore filter. Although the absorption by the filter, into which the aerosol penetrates to some extent, is always more important in the sandwich than in the usual geometry, the dependence of the absorption correction on the usually unknown average deposition depth is less pronounced. Assuming all the aerosol material to be collected at the very surface of the filter and hence being present in the centre of the sandwich to be analysed, leads to an extremely simple filter paper absorption correction which is less prone to uncertainties than more sophisticated corrections in the usual geometry requiring additional measurements. This is the case for all elements up from potassium on Whatman filters and up from phosphorus on Nuclepore filters.
A system for routine analysis of chlorine, sulphur, potassium and calcium in brine by X‐ray fluorescence spectrometry applying theoretical matrix corrections
Authors: van den Enk Jan E. , Janssen Jan J. , de Jongh Willy K.
Published: May 2005

A rapid procedure for the accurate determination of Cl, SO4, K and Ca in brines has been developed. The brine sample as received is put into a liquid sample holder and analysed by the PW 1410 X‐ray spectrometer with a helium attachment. The data are processed by an on‐line desk calculator HP 9830A. The elements mentioned strongly influence each other's X‐ray intensities and, consequently, matrix corrections have to be applied. The influence coefficients used for corrections are derived from physical data and give excellent results in that all calibration equations are perfectly linearized. The two instrument‐dependent calibration constants for each element are very stable in time and agree well between our three instruments of the same type. This stability is ensured by applying a monitor standard (pressed powder); thus, the occasional recalibration work is minimized. The precision for each element is better than 0.4% relative at a 95% confidence level and for a measuring time of about forty seconds per element. The calculated concentrations are in weight fractions, which are finally transformed to grams/litre or equivalents/litre. The specific gravity required for this transformation is calculated from the weight fractions.
The equivalent wavelength notion: Definition, properties, applications
Authors: Tertian R. , Vié Sage R. Le
Published: May 2005

The subject of a monochromatic radiation strictly equivalent to a given polychromatic spectral distribution is developed in accordance with usual analytical practice (e.g. by referring to relative intensities) assuming that (1) the polychromatic distribution can be any one, i.e. a continuous or discontinuous white spectrum, possibly including characteristic lines or not; (2) the fluorescent element is engaged in a homogeneous sample and is subject only to pure absorption effects (whether positive or negative) on the part of its neighbour elements. Important conclusions can then be derived.

These are (a) the existence for each composition of one, and only one, equivalent wavelength λe, the origin and mathematical determination of which are accurately described; (b) the fact that λe systematically decreases with increasing fluorescent element concentration in binary compositions, whatever the associate element, whether it be a positive or negative absorber. This property then clearly extends to any given matrix; (c) the existence of a simple relation of equivalence between absorbers, enabling us to consider any absorber and then any absorbing matrix in terms of ‘equivalents’ if we so choose; (d) as a consequence of (b) and (c), a novel description of influence coefficients for the absorption case, accounting for their systematic variation with fluorescent element concentration and introducing a definite correlation between coefficients belonging to different absorbers; (e) further interesting properties such as the effect of the ‘geometry’, as well as the effect of dilution, on the situation of equivalent wavelengths and the values of influence coefficients. In so far as absorption effects are considered all the facts of X‐ray fluorescence as induced by polychromatic excitation are covered by the present theory.
Iterative procedures in electron probe analysis corrections
Authors: Springer G.
Published: May 2005

The simple, Wegstein and hyperbolic procedures of iteration are compared and shown to differ only in the ways in which the derivative of the correction factor with respect to concentration are calculated. The simple and hyperbolic methods are demonstrated either to provide slow convergence in certain cases or to lead to wrong values, or even to show divergence. The Wegstein procedure is recommended as being, in general, the fastest and most reliable method.
A systematic error in energy dispersive microprobe analysis of Ni in steel due to the method of background subtraction
Authors: Malm Staffan
Published: May 2005

Experiments and a literature survey both show that energy dispersive microprobe analysis of Ni in steel generally gives substantial negative errors. This situation has been related to significantly lower X‐ray intensity ratios, k values, from an energy dispersive spectrometer system compared with a conventional wavelength dispersive spectrometer. Lower Fe contents in the specimens have been shown to give decreasing errors, which appear to be independent of the ZAF correction calculations.

It is suggested that the systematic error for Ni is caused by the method of background subtraction, which seems to reduce the Ni Kα area. The error can be minimized if peak‐height intensities are used and if the background level is measured and subtracted manually.
Determination of copper concentration in aqueous and organic phases from solvent extraction processes by X‐ray fluorescence spectrometry
Authors: Harris A. M. , Baines D. F.
Published: May 2005

An X‐ray fluorescence method has been developed to determine the metal concentration in the aqueous and organic phases from solvent extraction processes. The method has been specifically applied to the determination of copper, but can be extended to include other elements which form soluble organic complexes. Accuracy and precision are comparable with that obtainable by the electrogravimetric technique for the analysis of copper in aqueous solution, but are superior to the atomic absorption analysis of copper in organic solution. Rapid analysis is achieved by presenting a diluted sample directly to the spectrometer. Inter‐element absorption enhancement effects are corrected by the selection of a suitable internal standard which is added to the diluent.
A correction method for scattered background intensity of target elements in fluorescent X‐ray spectrometry
Authors: Murata Michihiro
Published: May 2005

A method for correcting scattered fluorescent X‐ray radiation arising from contaminants in a target of an X‐ray tube is described. The universal correction factor was obtained by measuring the intensity ratio of a characteristic radiation of an analytical element to a background radiation on a reference standard which contains none of the analytical element. The correction was performed by subtracting the intensity ratio of the reference standard from that of a sample. The method requires no calculation of correcting factors.
Data acquisition and control of wavelength and energy dispersive X‐ray spectrometers using a single minicomputer
Authors: Leyden D. E. , Lennox J. C.
Published: May 2005

A laboratory minicomputer has been interfaced to both a wavelength dispersive X‐ray fluorescence spectrometer and an energy dispersive Si(Li) X‐ray detector system. In the former mode of operation, the computer is used as a controller for the setting of the goniometer, initiation of count cycle and data acquisition. In the second case, the computer serves as a substitute for the conventional multi‐channel analyzer, acquiring spectral information from an ADC associated with the energy dispersive detector. In both modes of operation, data obtained may be displayed on either an oscilloscope or X‐Y recorder. All data obtained can also be transferred to cassette storage for subsequent retrieval and data reduction in higher level programming languages such as BASIC or FORTRAN.
The use of computers in X‐ray fluorescence analysis
Authors: Gunn Bernard M.
Published: May 2005

The cheapness of modern minicomputers coupled with the need for rapid and accurate output of X‐ray fluorescence analytical data makes the use of computers almost obligatory. The minicomputer has the advantages of immediate availability of results over other methods. In laboratories with an annual output of less than 10 000 determinations the on‐line card ‐punch or magnetic‐tape reader coupled through a terminal to a central computer is equally effective though slower.
Enhancement effects in X‐ray fluorescence analysis of rocks
Authors: Franzini M. , Leoni L. , Saitta M.
Published: May 2005

Utilizing artificially prepared powder pellets of samples, enhancement effects have been evaluated between the following pairs of elements: FeCa, FeSi, CaSi and SiAl. The experimental data suggest that in X‐ray fluorescence analysis of powdered rocks, for the considered elements over a very large range of concentrations, the enhancement effect can be regarded as a negative absorption.
A simplified fundamental parameters method for quantitative energy‐dispersive X‐ray fluorescence analysis
Authors: Shen R. B. , Russ J. C.
Published: May 2005

Stephenson's CORSET method has been adapted and expanded to the newer energy‐dispersive method to take advantage of its ability simultaneously to detect all elements (Z > 10) present (anticipated or not). Parameters such as the mass absorption coefficients and energies of absorption edges and emission lines of all elements are calculated as in Myklebust and Heinrich's FRAME program. The X‐ray intensities of pure elements versus atomic number of the elements for a given line (Kα or Lα) forms smooth curves as reported by Blum and Brandt. Because of the exceptional stability of energy‐dispersive methods (no moving parts, long tube life, etc.) and known overall spectrometer efficiency of these systems, they can be ‘standardized’ at installation by measuring (for a given tube, voltage and specimen holder configuration) several pure intensities (e.g. 6–10 covering the periodic table). Stored, these constants allow the calculation of the effective pure element intensity and the original intensity of the most effective excitation energy for any element that may be encountered. For an unknown sample, the program integrates net peak intensities (stripping away spectrum background and peak overlaps) and converts them to percentages with an iterative calculation. The accuracies are not as good as can be achieved with appropriate multiple standards. The compensating advantages are speed, flexibility and convenience. The entire program runs on‐line in a 16K, 16 bit minicomputer.
Proton‐induced X‐ray production in vanadium, iron, zinc, gallium, yttrium, cadmium, indium and tin
Authors: Rashiduzzaman Khan Md. , Hopkins A. G. , Crumpton D. , Francois P. E.
Published: May 2005

Measurements have been made of K X‐ray production from elements bombarded with protons. The X‐ray yields have been measured from thick targets of V, Fe, Zn, Ga, Y, Cd, In and Sn as a function of proton energy in the range 1–3 Me V. K‐shell ionization cross‐sections have been derived from the experimental data and these have been compared with the results of other workers and the predictions of the plane wave Born approximation (PWBA) and the binary encounter approximation (BEA).
A background correction for energy‐dispersive X‐ray analysis of thin sections
Authors: Sherry William M. , Vander Sande John B.
Published: May 2005

The ionization cross‐section of Kramers and the Thomson–Whiddington law have been used in the development of a background correction for quantitative electron microprobe analysis of thin sections employing an energy‐dispersive X‐ray detector. An expression has been derived which describes the X‐ray continuum emitted from a thin specimen while being irradiated with an energetic beam of electrons. The functional form of the expression describing the emitted continuum reduces to the equation derived by Kramers when specimen absorption is neglected. Theory demonstrates that for specimens of 2140 Å in thickness, a maximum difference of 16% exists between the continuum intensities predicted assuming absorption and neglecting absorption when working at an operating potential of 15 kV. Generally good agreement between the predicted emitted continuum and that measured from aluminum thin films is found.
Photographic recording of the spatial distribution of elements using an unmodified, flat‐crystal X‐ray spectrometer
Authors: Livingstone A.
Published: May 2005

Using simple constructional methods a special secondary collimator has been made from mica sheets and domestic aluminium foil which permits spectral images to be easily recorded (see Appendix). The collimator fits into the normal dual collimator tunnel of a commercial flat‐crystal spectrometer and instrument modification is unnecessary. A special film‐holding device ensures the spectral images are true to shape and size from the non‐focusing X‐ray spectrometer. Areas investigated range up to 0.9 inch2 (6 cm2)

Imperial and metric equivalents, and measurements, throughout the paper are only approximate.

and a small individual grain 0.001 inch2 (1 mm2) has been detected. Examples of specimen compositional differences, as well as variations in concentration levels, are given.
Mass thickness measurement of pure element films by X‐ray fluorescence spectroscopy
Authors: Laguitton Daniel
Published: May 2005

A precise and rapid method of measuring the mass thickness of pure element films using the LAMA Program to generate calibration curves by the fundamental parameters method is described. Only thick (‘bulk’) pure element standards are required thereby eliminating the necessity of preparing thin film standards. The accuracy is comparable to routine interferometry. A table giving the intensity ratios of the thin film to the corresponding thick standard is given for eighteen common elements and a thickness range of 500–100 000 Å, making it possible to apply the method without use of a computer.
X‐ray emission intensities of radionuclides in fallout from nuclear explosions
Authors: Sethi S. K. , Negi B. S.
Published: May 2005

X‐ray emission intensities (number of X‐ray photons per 100 disintegrations) have been computed from gamma ray intensities, internal conversion, electron capture coefficients of the radionuclides and the fluorescence yields of the daughter products of various radionuclides normally observed in fallout from nuclear explosions. X‐ray spectrometry of these radionuclides would supplement the information, currently being obtained by radiochemical separation and subsequent radioactive counting, gamma ray spectrometry of fallout samples using NaI(T1) or Ge(Li) detectors and multichannel analysers. No results are so far available in the literature based on X‐ray spectrometry of radionuclides in fallout because of non‐availability or scanty data on X‐ray emission intensities of various radionuclides.
Precision of a commercial, wavelength‐dispersive X‐ray fluorescence spectrometer. A case study
Authors: Pupp Christian
Published: May 2005

The reproducibility of a sequential X‐ray spectrometer (Siemens SRS‐1) with a ten‐sample changer was investigated. It was found that variations due to electronic drift and goniometer reset were 0.015% and 0.02% (relative standard deviation), and those from voltage and current reset were about 0.3%, but that major variations were introduced by the ten‐sample changer. Non‐equivalence of its positions resulted in a variation of 0.31% and position reset with simultaneous spinning gave on of 0.47% with large fluctuations. It appears that use of a ten‐specimen changer of a certain design instead of a two‐specimen changer results in loss of precision in return for speed and convenience.
The calculation of mylar film absorption correction coefficients in X‐ray spectrochemical analysis of aqueous samples
Authors: Dick J. G. , Wan C. C. , Difruscia R.
Published: May 2005

In the analysis of specimens in aqueous media by the method of X‐ray fluorescence the measured intensity was found to be strongly affected by the mylar film used to cover the solution specimen cells.1,2 An increasingly critical absorbance level is observed with decreasing atomic number (increasing wavelength) of the element under examination. The investigation establishes correction coefficients relative to mylar film.
The X‐ray fluorescence analysis of ferronibium by a fusion method
Authors: Giles H. L. , Holmes G. M.
Published: May 2005

An X‐ray method has been developed for the routine determination of niobium, tantalum and residual elements inferrniobium. The sample is pre‐ooxidized and fuded in a misture of lanthanum oxide and lithium tetraborate. Calibration is by synthetic standards; molybdenum is added as internal standard for niobium, and corrections are applied for interferences on tantalum.
X‐ray fluorescence analysis of nibium‐germanium alloys
Authors: Vicente Victoria A. , Rasmussen Svend Erik
Published: May 2005

A simple approach of the study of phase equilibria in niobium‐germanium alloys involves passing a floating molten zone along the alloy, cutting the resolidified rod into several, and analysing these sections by X‐ray fluoresce spectrometry and X‐ray diffraction. The relative net X‐ray fluorescent intensities were corrected for negative absorption effects, using a semi‐empirical procedure. The ‘effective wavelengh’ for exicitation of niobium and of germanium were deduced from experimental alpha‐coefficients.
The determination of the valency of manganese in minerals by X‐ray fluorescence spectroscopy
Authors: Urch D. S. , Wood P. R.
Published: May 2005

The Mn Kβ1,3, Kβ′ X‐ray emission peak profile varies in a characteristic way with the valency of manganese, Proviede that the ligand‐atom environment remains contant. Kβ′ becomes mopre prominent as the oxidation state is reduced. XRF nanalysis of geological sample can, therefore, be easily extended to include a determination of the predominant valence state of any manganese present.
Study of X‐ray L2 absorption edges of Gd, Dy, Ho and Er in metals and compunds
Authors: Angarwal B. K. , Agarwal B. R. K.
Published: May 2005

The positions and shapes of L2 X‐ray absorption edges of Gd, Dy, Ho and Er have been studied in metals and in oxides and chlorides, using a forty centimetre benbt mica crystal spectrograph. It has been found that the L2 edge shifts towards the high energy side in the compounds and that the chemical shift ΔE depends on the degree of covalency involved. The white line structure at the edge has been analysed in terms of transitions of L2 shell electron to optical nd (n≥5) states.
Application of direct peak analylsis to energy‐dispersive X‐ray fluoescence spectra
Authors: Nielson Kirk K.
Published: May 2005

A modified covell method for direct peak analysis has been applied to energy‐dispersiv X‐ray flourescence spectra. The method is background independent and is well‐suited to computerized data reduction. It provides acceptable precision, minimizes errors from instrumental gain shift, and permits peak overlap correction. Peak overlap errors exhibit both positive and negative nodes as a function of peak separation distance, and are corrected using concentration ratios determined from thin, single‐element standards. Peak precisions and overlaps are evaluated as a function of window width to aid in width selection. Least‐square polynomial smoothing prior to peak analysis significantly improves peak area precisions without significantly affecting their accuracies.
The evaluation of the thallium acid phthalate crystal for X‐ray fluorescene spectrometry
Authors: Wybega F. T.
Published: May 2005

The Thallium Acid Phthalate (TIAP) analysing crystal is compared with KAP, RBAP and pentaerythritol (PE) crystal for the determination of light elements. Peak and background intensities are compared for various crystal‐collimator combinations. It is shown that TIAP is a very useful crystal to cover the range of elements F to Si.
An iterative method for determining background intensities used in XRF calibration lines for flux‐fusion silicate rock analysis
Authors: Parker R. J.
Published: May 2005

In major element rock analysis using XRF and fused samples and standards, the construction of standard calibration lines is facilitated by the accurate knowledge of the background intensities for the elements analyed. As an alternative to measuring the background ‘off peak’ or on blanks, an iterative technique is proposed. This technique is based on repeatedly incrementing the background value until the best calibration line has been found. The quality of the calibration line is evaluated in terms of the average relative and average absolute errors. Comparative data, presented for calibration lines constructed from (1) backgrounds measured from blanks and (2) backgrounds determined by iterationm, show that the iterative technique produces superior calibrations. The analytical techniques have been tested by analysing international rock standards as unknown samples.
Appearance of the gold MIV, V absorption edges in the background of energy‐dispersive X‐ray spectra
Authors: Brombach J. D.
Published: May 2005

Background calculations for low‐energy energy‐dispersive X‐ray spectra from biological ice, when attempting quantitative microanalysis, must take into account the anomalous gold MIV, V absorption edges at 2220 and 2307 eV. The discrepancy between the mass absorption coefficient from generalized tables used in the electron microprobe analysis and those values actually observed is pointed out. The spectral shape of the Au MIV, V edges is discussed in terms of the photoionization cross‐section of the 3d‐subshell. Theoretical and experimental results are comparted with the table values. A formula used in the calculation of spectrometer efficiency and spectral background is given.
Experimental determination of XRE interelement correction coefficients from binary systems using a modified lachance‐traill approach
Authors: Difruscoa R. , Dick J. G. , Wan C. C.
Published: May 2005

A modified Lanchance–Trail approach is presented for the empirical determination of XRF interelement correction coefficients through experimentation. An exhaustive study of binary systems involving aqueous solution media has been used to obtain the true effects of one element on another, with the additional possibility of taking into consideration other effects which become apparent, such as enhancement effects. The method is described in detail, with several examples provided to show the effectiveness of the procedure. A total of approximately 200 coefficients have been investigated and are discussed.
Pitfalls in linear and non‐linear profile‐fitting procedures for resolving severely overlapped peaks
Authors: Statham Peter J.
Published: May 2005

Linear and non‐linear least‐squares profile‐fitting procedures are compared in their ability to resolve severely overlapping peaks in X‐ray spectra. With linear methods, errors due to inaccuracies in peak position and width are likely to be greater than statistical errors for a spectrom with 500 K counts unless the spectrometer can maintain a temporal and count are stability of 1 eV or better. While non‐linear, iterative, procedures can accomodate changes in position and width of peaks, they are difficult to analyse therotically so simulations have been designed to examine performance. Examples are given where, despite exact knowledge of peak width and separation, the best fit in the ‘chi‐square’ sense corresponds to peak heights which are totally incorrect. Estimates of statistical error are virtually meaningless when convergence occurs to such inapprooriate minima but rather precise starting values for the unknown parameters are required to ensure convergence to a relistic solution. In view of these potential difficulties and the lack of any theoritical analysis of the instabilties introduced by statistical noise, errors in background subtraction or unsuitable parameterization of peak models, it is felt that linear method are preferable. Thus, high spectrometer stability still seems to be unavoidable if one is to exploit the availabler statistical accuracy in an X‐ray spectrum.
Quantitative X‐ray spectrometric analyses with a cold cathode tube attachment
Authors: Mills J. C. , Belcher C. B.
Published: May 2005

A CGR cold cathode tube for X‐ray anlysis of very light elements has been attached to a sequential Siemens XRF spectrometer. Economic consideraions justify a rapid changeover attachment rather than the purchase of a separate spectrometer which can be applied to a few elements. The essential conceppts developed for successful integration of the attachment with the spectrometer are described. An automic activated alumina trap system to remove backstreaming oil vapours was incorporated with the existing vacuum logic. The current stabilization circuit of the generator was redesigned in order to acheive quantitative analyses. The developed attachment has competitive applicability to the quantitative analyses of magnesium and lighter elements. For magnesium the cold cathode tube achieves a large deduction in both matrix absorption effects and high order spectral interferences when compared with a typical chromium tube.
Routine performance of a matrix‐correction free X‐ray fluorescence spectrometric method for rock analysis
Authors: Govindaraju K. , Montanari R.
Published: May 2005

In modern geochemical laboratoriesX‐tay fluorescence spectrometry (XRFS) is a highly favoured analytical technique particularly when the need for geochemical data is relatively important. The analytical procedures currently employed involve XRFS analysis of lithium borate fused glass disc of rock samples, followed by computer generated mathematical corrections for the usual matrix effects. A significantly different procedure, free from mathematical matrix effect corrections, is presented here. After the lithium borate fusion step, the ground fusion product is dissolved by thorough mixing with an aqueous suspension, of a strong acid cation exchange resin in H+ form. During the caution exchange dissolution, the cautions originally present in the sample are transfered quantitatively and uniformly to the resin pahse. The oven‐dried resin heads coated as a thin film on a strip of adhesive paper are analysed. The routine performance of the procedure is illustrated with the data accumulated on six major elements (Al, Fe, Ca, Mg, K and Ti) in five international rock reference samples during a period of one academic year. The main feature of this analytical method is the production of high quality geochemical data without any need for mathematical corrections.
Praktische Fehlertheorie der Röntgenspektrometrie
Authors: Plesch R.
Published: May 2005

Die Qualität eines Analysenverfahrens ist in erster Linie durch seinen Fehler gekennzeichnet, aus dem sich als weiters wichtige Kenngrössen die Unterscheidungsgrenze und die Nachweisgrenze ableiten lassen. Alle diese Fehlergrössen werden unter den Bedingungen der analytischen Praxis behandelt. Es wird ferner gezeigt, dass die vielfach gemachten idealisierten Annahmen für die gennten Fehlergrö zu Werten führen, die praktisch nicht erreichbar und daher fü die Praxis ohne Bedeutung sind.
X‐ray microanalytical senstivity and spatial resolution in scanning transmission electron microscopes
Authors: Faulkner R. G. , Norgård K.
Published: May 2005

Experimental and theoretical studies of fine electron beam interactions with film specimens are described. It is shown that a Monte Carlo‐based method for plotting electron trajectories can give good indications of both X‐ray spatial resoultion and sensitivity as experienced during X‐ray microanalysis in scanning transmission electron microscopes (STEM). The main operational parameters considered are aperture and lens settings, beam accelerating voltage and specimen thickness. Based on theroretically and experimentally determined data, as set of conditions for optimum X‐ray detection sensitivity and X‐ray spatial resoultion for nickel and aluminium are presented. It is shown that little advantage is gained by performing X‐ray microanalysis at beam accelerating voltages greater than 100kV. Also the necessity to condense the beam spot size to less than 100 Å is relatively unimportant from the viewpoint of improving X‐ray spatial resolution in STEM.
Measure of precision in the determination of concentration
Authors: Kotrba Zdeněk
Published: May 2005

An equation has been derived for the computaion of the standard deviation of the results of X‐ray micro analysis. The contributions of partial standard deviations of all magnitudes are included. The equation is gernerally applicable to multiple measurements and various methods of measurements.
The direct measurement of Ga in binary PuGa alloys using X‐ray spectrometic techniques
Authors: Wallace P. L. , Homser P. K. , Walden J. C. , Haugen W. L.
Published: May 2005

Three X‐ray spectrometric procedures have been developed to directly measure the Ga content in binary PuGa alloys. In one procedure en energy‐dispersive spectrometer is used; in the other two a wavelengh‐dispersive spectrometer is used. Certified reference alloys with known Ga content have been produced, and simple procedures to handle them safely have been developed. We have constructed an energy‐dispersive spectrometer system for analyzing Pu‐containing materials and charactrerized the low energy gamma‐ray spectrum of Pu.
Corrections for scattering in X‐ray fluorescence experiments
Authors: Keith H. D. , Loomis T. C.
Published: May 2005

Coherent and incoherent scattering processes are commonly ignored, or at best estimated only crudely, in X‐ray fluorescence experimently designed either to measure physical constants or to effect nondestructive chemical analysis of mixtures and alloys. The influence of this scattering is of second order, but is nevertheless large enough (generally 2–5%) to overshadow inherent errors in experimental measurement. In this paper, we develop a formalsim for calculating scattering corrections applicable to experiments involving either thin polycrystalline or amorphus samples studied in transmission or thick samples of a similar kind examined using reflection geometry. Our principal approximations are physical; we assume (i) that crystal line structure and texture in the sample serve merely to modulate the angular distribution of coherent scattering can be ignored. Mathermatical development of the model is essentially exact. Adequacy of approxination (i) is supported by previously published experimental and theoretical work; as for approximation (ii), we have found that results do not depend crucially upon the particular angular distribution function assumed for scattering. We believe, at a conservative estimate, that overll errors in our scattering corrections are in almost all cases of interest less than 25%; data to which they are applied, therefore are, potentially accrate to better than 0.5–1.25% Three important effects have to be considered: (a) the generation of fluorescence radiation which has been scattered within the sample,(b)the scattering of fluorescent radiation away from the acceptance aperture of lthe detector, and (c)the scattering of fluorescent radiation into this aperture. In our formalism, only (a)and (c)need be calculated explicityly. Corrections are expressed simply as products of quotients σ/μ with certain enhancement terms (μ being a total attenuation constant and σ an attenuation constant for scattering). In transmission geometry, the enhancement terms are complicated functions of transmission factors for exciting and fluorescent radiations only and, in reflection geometry, they are simpler functions of angles specified by the experimental arrangement used and the total attenuation constants for exciting and fluorescent radiations. It turns out in many cases that (c) above is the predominant effect and, commonly, the positive contribution to measured fluorescent intensity made by scatting into the detector outweighs substantially the negative contribution made by scattering out of the detector. Results are also expressed in simple graphical form in terms of effective attenuation constants for exciting and fluorescent radiations; in this form they are readily available for use by the reader without the necessity for further calculation. Surprisingly, effective attenuation constants are generally smaller, often consideraby smaller, than constants representing photoelectric absorption alone.
Quantitative energy‐dispersive X‐ray analysis of transition elements in aluminium alloys, at concentrations of less than 1%
Authors: Mora R.
Published: May 2005

A SEM/EDAX/NOVA‐2 system, with quantitative analysis program EDIT/EP7–ZAF auto, has been used for analysing the transition elements in aluminium alloys. Handling the sample carefully and choosing optimum operating conditions, has enabled us to determine the concentrations below 1% of these elements, with a percentage error less than ±10%, in most elements, except in Zn, due to interferences in its Kα line with the Cu Kβ.
Escape peak losses in Si(Li) detectors
Authors: Sioshansi P. , Lodhi A. S.
Published: May 2005

Escape peak losses in Si(Li) detectors for X‐rays in the energy range 2.3–14.2 keV are measured and compared with calculations for normal incidence geometry. The importance of the results for multi‐elemental X‐ray emission analysis is pointed out.
A fundamental parameter method for analysis of alloys by isotope‐excited X‐ray fluorescence
Authors: Kis‐Varga M.
Published: May 2005

A new fundamental parameter method applied to energy dispersive X‐ray spectrometry is presented. Am‐241 and I‐125 radioisotope sources were used for excitation. The method is applied to copper–zinc–lead ternary and copper–zinc–lead–tin quaternary alloys and to high‐alloy steel specimens. It is also tested using data given in the literature. The measurements and calculations were performed on‐line by a program running in a 16K, 12 bit minicomputer interfaced to a multichannel analyser. The results were compared with wet chemical analysis.
Empirical method of matrix effect elimination for samples of ‘intermediate’ thickness in EDXRF analysis
Authors: Hołyńska B. , Markowicz A.
Published: May 2005

A method of elimination of absorption matrix effects in samples of ‘intermediate’ thickness, based on the use of measurements of the intensities of fluorescent X‐rays of all determined elements and the intensity of Compton back‐scattered radiation, is described. An empirical correction equation proposed in this paper has been checked experimentally using the samples obtained by precipitation of several elements from water solution by sodium diethyldithiocarbamate (NaDDTC). The accuracy of determinations of Cr, Fe, Zn and Pb varies from 1 to 18% (1 s.d.) for mass per unit area from 2000 to 60 μg cm−2, respectively.
X‐Ray spectrometric analysis by fusion methods. A simple procedure for determining effective influence coefficients
Authors: Tertian R.
Published: May 2005

A convenient modification of the so‐called self‐consistent calibration method results in a simple, flexible, coherent procedure for complete analysis of any multicomponent system by means of fusion methods. With low dilution techniques, the influence coefficients obtained allow accurate analysis around a typical standard composition, i.e. within restricted concentration ranges, as often occurs in industrial applications. Resorting to higher dilution rates allows one to extend validity ranges at will, according to one's purpose, but at the cost of a lower sensitivity.
Utilisation du Rayonnement Primaire Diffusé par l'Echantillon pour une Détermination Rapide et Précise des Eléments Traces dans les Roches
Authors: Vié le Sage R. , Quisefit J. P. , de la Bâtie R. Dejean , Faucherre J.
Published: May 2005

L'association des techniques de Feather et Willis d'une part, Bougault et al. d'autre part permet de développer une méthode simple et efficace de détermination des éléments traces dans les roches. Le facteur de correction matricielle ainsi que le niveau du fond vrai sont déduits de la diffusion du specimen, mesurée d'après l'intensité d'un pic Compton (ou à défaut de celle d'un fond libre d'interférences), et introduits dans une équation unique du type Bougault qui délivre la concentration de l'élément trace. On décrit les bases théoriques et expérimentales de cette méthode, de même qu'une application typique à la détermination de Ni, Zn, Rb, Sr, Zr et Nb dans une série de roches étalons.
X‐Ray K‐absorption edge of bromine in some cobalt complexes
Authors: Kumar A. , Nigam A. N.
Published: May 2005

A method for photographic recording of the X‐ray K‐absorption edge of bromine has been developed in which the effect of the photographic emulsion's bromine is nullified. Using this method the Br K‐absorption edge in some complexes containing bromine were recorded with a view to studying the effect of chemical coordination. The effect of the second coordination sphere on the absorption edge of an ion in the first coordination sphere, in a complex compound, has been investigated.
Trace analysis of estuarine brown algae by energy‐dispersive X‐ray fluorescence
Authors: Sauter L. , van der Ben D. , Van Grieken R.
Published: May 2005

Brown algae, which are good indicators for estuarine metal pollution, can advantageously be analysed by energy‐dispersive X‐ray fluorescence. The use of thin film samples and samples of intermediate thickness has several advantages over the conventional thick pellet procedure. A quite homogeneous thin target is prepared by suspending 15 mg of dried and ground seaweed powder in bi‐distilled water and evaporating the slurry on a 10 cm2 Mylar foil held in a Teflon ring. The effective sample weight in the beam is calculated by a procedure based on the scatter peaks in the spectrum. Sensitivities are typically in the 2–15 ppm range. The coefficient of variation per analysis averaged over ten elements amounts to 10%. The natural concentration variation in seaweed specimens at one location is 13%. Samples from locations in the more polluted western Scheldt estuary yield significantly higher values for several elements, relative to the eastern Scheldt sites. Possible trace element variations between the top and base of plants, and between different seaweed specimens and sampling seasons, are discussed.
Quantitative volumetric determination of gamma‐2 content in dental amalgam by electron microprobe analysis
Authors: Bryant R. W. , Moran K. J.
Published: May 2005

A method has been developed, using an automated electron microprobe, to determine quantitatively from the uncorrected X‐ray data the volume percentage of one phase (Sn–Hg or γ2 phase) in a three‐phase amalgam. The mean γ2 content determined by this technique was compared with results obtained from an optical image analysis of backscattered electron (BSE) images for this amalgam. The technique offers several distinct advantages over previously described methods. It produces easily interpretable data in a numerical and pictorial form, allowing ready comparison between different amalgams. It is free of operator intervention to discriminate phases, and offers the prospect of being a reliable method of determining the γ2 content in amalgams possessing smaller percentages of this phase.
Visual CRO display of pulse height distribution including discriminator setting for a single channel X‐ray analyser
Authors: Shaw S. E.
Published: May 2005

An outline for a simple pulse spectroscope which attaches to a standard laboratory CRO is presented. The peak amplitude (voltage) of each pulse from the linear amplifier of a single channel X‐ray analyser is stored for the duration of one oscilloscope trace. For each amplifier pulse, input from the discriminator is tested and if there is coincidence of pulses the oscilloscope beam is blanked for approximately the first 2 cm of its traverse across the screen. Repetition of pulses forms a pulse height distribution with a rectangular dark area marking the position of the discriminator window.
Retardation of ammonium acid phthalate crystal surface decomposition
Authors: Barrus D. M. , Blake R. L.
Published: May 2005

Ammonium acid phthalate crystal surfaces can be vapor‐deposited with a thin layer of aluminum to prevent surface deterioration in high‐vacuum environments and in room air.
An electronic modification of an automatic x‐ray fluorescence spectrometer with sample loader to increase the flexibility of the measurement sequence
Authors: Smith T. K.
Published: May 2005

The Philips PW 1450/00 or /10 automatic hardware‐programmed X‐ray spectrometer, when used in conjunction with the PW 1466 60 position sample loader, permits measurement of both standard and unknown using the same channel only when the ratio mode is selected. Further, a standard must be measured for every unknown. An electronic modification is described which overcomes both of these restrictions.
A new system for on‐line x‐ray topography
Authors: Komyak N. I. , Lutsau V. G. , Efanov V. P. , Ivanov S. A.
Published: May 2005

A new system for on‐line X‐ray topography is described, in which relative motions of separate assemblies are completely eliminated. The main elements of the system are a low‐power raster‐type X‐ray source with a transmission target and a multi‐capillary collimator. It takes about 2.5–3 min to produce a topograph of silicon single‐crystal (20 × 20 × 0.3mm) when the radiation source power is only 10W.
Optimization of trace analysis by pixe: Angular dependence of the background continuum
Authors: Renan M. J.
Published: May 2005

In charged particle induced X‐ray emission studies, the characteristic X‐rays are superimposed on a continuous background of electromagnetic radiation. This background is a significant source of uncertainty when charged particle induced X‐ray emission is used for analytical purposes. It is demonstrated that the angular distribution of secondary electron bremsstrahlung exhibits significant structure and may be exploited to improve the detection limits attainable with this method. For low‐energy continuum X‐rays, good agreement is obtained with predictions of the relativistic retardation model. Deviations at higher photon energies are attributed to Compton scattered γ‐rays. Finally, suggestions are made regarding optimum energy and angle selections for direct application of particle induced X‐ray emission as an analytical technique, especially when biological samples are investigated.
The computer control of an electron probe microanalyser using camac and coral‐66
Authors: Swindells N.
Published: May 2005

A computer control system for an electron probe microanalyser has been designed using CORAL‐66, a high level compiler language, for the control program and CAMAC modules for the instrument interface. The consequences of the choices made in the design are discussed. The performance of the system was measured by comparing the results from carrying out typical operations by hand and by computer control. The results showed an improvement in precision for general operation and analysis, a reduction in the time for analysis and an improvement in operator performance from using the control system.
An in‐depth study of energy‐dispersive x‐ray spectra
Authors: Van Espen P. , Nullens H. , Adams F.
Published: May 2005

A detailed study of energy‐dispersive X‐ray spectra is undertaken. Considerable attention is given to a method for a systematic and accurate description of the K and L spectra; a digital correction for the peak profile is evaluated. The following second order effects and spectral artefacts are investigated: radiative Auger transitions, spectral background components, Raman scattering of X‐rays, silicon escape, fluorescence of the detector materials, and sum peaks.
An x‐ray source with focal spot scanning
Authors: Belyaev B. F. , Gushchin V. A. , Ivanov S. A. , Fedorova L. F.
Published: May 2005

The construction of a demountable X‐Ray tube with focal spot scanning intended for operation as an X‐ray source in scanning X‐ray microscopes is described.
Eine empirische Methode zur Korrektur des Einflusses der Korngröße bei der Röntgenfluoreszenzanalyse von gepulverten Glasproben und anderen Einphasensystemen
Authors: Dümecke Gerhard
Published: May 2005

Es wird gezeigt, daß die in der Literatur beschriebenen einfachen Modellezur Korrektur des Korngrößeneinflusses für die quantitative Röntgenfluoreszenzanalyse von Elementen mit niedriger Ordnungszahl (⩽ 20) in gepreßten Pulverproben nicht ausreichen. Auf der Basis eines empirischen Korrekturvorschlages ist es jedoch möglich, ein mit einem Bindemittel verpreßtes Pulver ohne Kenntnis seiner mittleren Korngröße mit einer für die Praxis ausreichenden Genauigkeit zu analysieren. Es werden die zur Analysenberechnung notwendigen Voraussetzungen beschrieben und die verwendeten mathematischen Formeln am Beispiel eines Glaspulvers erläutert.
Runaways in X‐ray spectrometry
Authors: Plesch R.
Published: May 2005

A runaway criterion is proposed for X‐ray spectrometry which is based on the standard deviations obtained from the standard specimens with and without the analysis value to be tested. The standard deviations which are printed out on modern equipment are compared by means of the F test. The procedure is explained by means of examples. The consequences for the analysis of unknown specimens are discussed.