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Abstract A fundamental parameter-based quantification scheme for confocal XRF was applied to sub-micron synchrotron radiation X-ray fluorescence (SR-XRF) data obtained at the beamline P06 of the Deutsches Elektronen-Synchrotron (DESY, Hamburg, Germany) from two sections C0033-01 and C0033-04 that were wet cut from rock fragment C0033 collected from Cb-type asteroid (162173) Ryugu by JAXA’s Hayabusa2 mission. Trace-element quantifications show that C0033 bulk matrix is CI-like, whereas individual mineral grains (i.e., magnetite, pyrrhotite, dolomite, apatite and breunnerite) show, depending on the respective phase, minor to strong deviations. The non-destructive nature of SR-XRF coupled with a new PyMca (a Python toolkit for XRF data analysis)-based quantification approach, performed in parallel with the synchrotron experiments, proves to be an attractive tool for the initial analysis of samples from return missions, such as Hayabusa2 and OSIRIS-REx, the latter returning material from a B-type asteroid (101955) Bennu in 2023. Graphical Abstract

On 14 December 2013 (UTC), China's Chang'E-3 (CE-3) succeeded in landing on the Moon's surface. The CE-3 landing site is in northern Mare Imbrium and several tens of meters away from the rim of a young crater with a few hundred meters in diameter. In-situ measurements of lunar soil around the roving area were conducted from Active Particle-induced X-ray Spectrometer (APXS) onboard Yutu rover. Three relatively young lunar soil samples in the CE-3 landing site were investigated. Previous studies suggested that these samples are a new type of basalt, not discovered yet in previous missions before the CE-3 in-situ measurements. It plays an essential role in promoting the understanding of lunar volcanic history. However, their results are deviated, and thus scrutinizing the data as per our optimized model to derive a more precise result is of necessity. In this paper, we present an optimized model for data analysis based on APXS measurements to derive the major elements concentrations. The optimized model has the advantages of reliability and being independent of calibration by ground standards. The particle size effect is applied in lunar X-ray fluorescence modeling for correction, improving the accuracy in determining the elemental concentrations for the actual measurement. Our results are distinct in the correlation plots by carrying out a comparison with previous lunar regolith samples from Apollo, Luna, and Chang'E-5 missions, indicating that the CE-3 landing site is a new region apart from previous in-situ or laboratory detection prior to the CE-3 measurements. It suggests a kind of young mare basalt with unusual petrological characteristics compared with previous samples and similar geochemical properties of CE-3 landing site and western Procellarum and Imbrium (WPI), with a signature of western Procellarum. [ABSTRACT FROM AUTHOR]

A fundamental parameter-based quantification scheme for confocal XRF was applied to sub-micron synchrotron radiation X-ray fluorescence (SR-XRF) data obtained at the beamline P06 of the Deutsches Elektronen-Synchrotron (DESY, Hamburg, Germany) from two sections C0033-01 and C0033-04 that were wet cut from rock fragment C0033 collected from Cb-type asteroid (162173) Ryugu by JAXA's Hayabusa2 mission. Trace-element quantifications show that C0033 bulk matrix is CI-like, whereas individual mineral grains (i.e., magnetite, pyrrhotite, dolomite, apatite and breunnerite) show, depending on the respective phase, minor to strong deviations. The non-destructive nature of SR-XRF coupled with a new PyMca (a Python toolkit for XRF data analysis)-based quantification approach, performed in parallel with the synchrotron experiments, proves to be an attractive tool for the initial analysis of samples from return missions, such as Hayabusa2 and OSIRIS-REx, the latter returning material from a B-type asteroid (101955) Bennu in 2023. [ABSTRACT FROM AUTHOR]

Elemental analysis of ferromanganese formations (first of all, the determination of ore elements) is a necessary stage in the development of ore deposits. A technique for X-ray fluorescence quantitative analysis was proposed for the determination of iron, manganese, cobalt, nickel, copper, and zinc in oceanic ferromanganese formations (nodules and crusts). The studies were performed using a S4 Pioneer wavelength-dispersive spectrometer equipped with a LiF (200) crystal and a scintillation detector. In order to plot the calibration curves, sets of certified reference materials such as ferromanganese nodules, cobalt-bearing ferromanganese crusts, and pelagic sediments previously dried at 105°C for 24 h to remove hygroscopic moisture were used. Two sample preparation techniques were compared: pressing of powder samples with the use a boric acid substrate and homogenizing via fusion with lithium tetraborate at a ratio of 1 : 30 in an electric furnace at 1050°C. For each sample preparation technique, spectral overlaps and matrix correction methods (theoretical and empirical) were considered, and optimal calibration curves for determining ore elements were chosen. The accuracy of the X-ray fluorescence technique was assessed via analyzing a reference material FeMn-1 with a certified content of ore elements and a reference ferromanganese nodule sample preliminarily analyzed using a PerkinElmer M403 atomic absorption spectrometer. Both homogenization via fusion and analysis of pressed samples provide quantitative X-ray fluorescence determination of the main ore elements and can be used to assess the industrial significance of oceanic ferromanganese formations. [ABSTRACT FROM AUTHOR]

A mathematical model and a software program (FLUOR81) were developed to implement the fundamental parameter method for X-ray fluorescence analysis of new alloy types. The model takes into account the X-ray tube excitation by polychromatic radiation and the secondary excitation of some elements by others. The program was tested using state standard samples of steels and alloys with nickel and cobalt matrices to show that the intensity of characteristic lines could be calibrated using pure elements in the absence of standard samples. In this case, the relative measurement error was no more than 3–4%. This approach was employed for mathematical modeling of the mutual influence of elements in the AlCrFeCoNiCu high-entropy alloy (HEA). The stoichiometric coefficients in the AlCrxFeCoxNixCu alloy were varied (x = 0.5, 1, 2) to find that the relative deviations of initial concentrations of components (ignoring their mutual influence) from the stoichiometric values were within ±50% and slightly changed with concentration. These patterns can be used for semiquantitative estimates of the HEA compositions for which no standard samples are available. To obtain results with a relative error of 3–4%, calculations with the software developed are needed. [ABSTRACT FROM AUTHOR]

Wavelength dispersive X-ray fluorescence spectrometry (WDXRF) is a suitable technique for the characterization of contaminated mining sites, providing a quick and reliable screening for areas of significant contamination. This study established and validated a non-destructive methodology for quantitative simultaneous determination of major and minor constituents in soil and sediments by WDXRF, which was further applied to quantify soil and sediment samples from Osamu Utsumi uranium mine (Caldas, Minas Gerais, Brazil). Elements such as Ce, La, Nd, Mn and U were found in more concentrated levels in the calcium diuranate deposit (DUCA), whereas Fe and Al were found at higher levels in the soil samples corresponding to sites where accentuated leaching processes have occurred. Comparatively, the levels of U and rare-earth elements were found in significantly higher levels in the sediments retrieved from the mine's pit as a result of acid mine drainage. These findings are believed to be useful as an initial environmental assessment for the decommissioning process of the mine. [ABSTRACT FROM AUTHOR]

The accurate evaluation of the absolute intensity of the gamma-ray transition 1001.03 keV of 234m Pa is crucial for accurate determination of 238 U in nuclear material and environmental samples. Over the last decades, a wide range of 1001.03 keV absolute intensity values were published by different researchers and ranged from 0.59 to 1.12%. Nowadays, one of the most commonly used values is 0.847 ± 0.008% that seems not accurate and would eventually lead to an overestimation of 238 U activity concentration. The absolute intensity of 1001.03 keV gamma transition was re-evaluated using different fundamental parameter method (FPM) modes, uranium ore and granite samples, samples' geometries, sample-to-detectors’ geometries and gamma ray spectrometers. The mean ± standard deviation of newly optimized absolute intensity value is 1.067 ± 0.084% with an average relative bias of - 20% from the commonly used value. [ABSTRACT FROM AUTHOR]

Crystallite size strain effect the mechanical, electric, magnetic and optical properties of many kind of the nanomaterials. The effects of the finite crystallite size and lattice strain can be very well observed as the deformation in the shape of the X-ray line profile (XRLP). In this contribution we have used the fundamental parameter method (FP) (Arfken and Weber, 2000, Bot et al., 2015) to evaluate the nanostructure materials assuming a theoretical model of experimental XRLP. In this contribution we have used various distribution functions such as normal, lognormal, Gumbel, Maxwell and Student. The best values of the crystallite size of nanostructured materials are chosen by analysis of root mean squares of residuals and by correlation matrix of the fit parameters. The entire procedure was implemented in the GnuPlot script. [ABSTRACT FROM AUTHOR]

This review presents the features of the application of X-ray fluorescence analysis to the study of a chemical composition and thickness of films and surface coatings. Examples of X-ray fluorescence analysis of coating surfaces of simple and complex configurations are presented. The variants of considering the matrix effects and coating thickness for various materials are discussed. The possibilities of methodological techniques using scattered primary X-ray radiation or fluorescence radiation from a substrate on which a film is applied to determine its attenuating characteristics are discussed. The features determination of the chemical composition and coatings thickness and thin films when using the XRF version with total external reflection (TXRF) spectrometers are considered. The examples of performance of conventional XRF analysis are given. The results of a round‐robin test with application of X‐ray fluorescence thickness determination of multilayered samples (Au/Ni/Cu) on a chromium coated quartz glass substrate were presented and discussed. • The review of the application of XRF to the study of films and coatings is presented. • Specific requirements in the study of films and coating-substrate are considered. • Using of the intensity ratio of X-ray lines to research of multilayer are discussed. [ABSTRACT FROM AUTHOR]

Abstract: A new method for the quantification of X-ray fluorescence (XRF) was derived based on the fundamental parameter method (FPM). The FPM equations were adapted to accommodate the special case of confocal nano-XRF, i.e. X-ray nano-beam excitation coupled with confocal detection, taking into account the special characteristics of the detector channel polycapillary. A thorough error estimation algorithm based on the Monte Carlo method was applied, producing a detailed analysis of the uncertainties of the quantification results. The new FPM algorithm was applied on confocal nano-XRF data obtained from cometary dust returned by NASA''s Stardust mission, recorded at beamline ID13 of the European Synchrotron Radiation Facility. [Copyright &y& Elsevier]

Abstract: The fundamental parameter method for quantitative SXRF and PIXE analysis and imaging using the dynamic analysis method is extended to model the changing X-ray yields and detector sensitivity with angle across large detector arrays. The method is implemented in the GeoPIXE software and applied to cope with the large solid-angle of the new Maia 384 detector array and its 96 detector prototype developed by CSIRO and BNL for SXRF imaging applications at the Australian and NSLS synchrotrons. Peak-to-background is controlled by mitigating charge-sharing between detectors through careful optimization of a patterned molybdenum absorber mask. A geological application demonstrates the capability of the method to produce high definition elemental images up to ∼100M pixels in size. [Copyright &y& Elsevier]

Abstract: X-ray fluorescence data bases have significant contradictions, and inconsistencies. We have identified that the main source of the contradictions, after the human factors, is rooted in the signal processing approaches. We have developed signal processors to overcome many of the problems by maximizing the information available to the analyst. These non-paralyzable, fully digital signal processors have yielded improved resolution, line shape, tailing and pile up recognition. The signal processors account for and register all events, sorting them into two spectra, one spectrum for the desirable or accepted events, and one spectrum for the rejected events. The information contained in the rejected spectrum is mandatory to have control over the measurement and to make a proper accounting and allocation of the events. It has established the basis for the application of the fundamental parameter method approach. A fundamental parameter program was also developed. The primary X-ray line shape (Lorentzian) is convoluted with a system line shape (Gaussian) and corrected for the sample material absorption, X-ray absorbers and detector efficiency. The peaks also can have, a lower and upper energy side tailing, including the physical interaction based long range functions. It also employs a peak and continuum pile up and can handle layered samples of up to five layers. The application of a fundamental parameter method demands the proper equipment characterization. We have also developed an inverse fundamental parameter method software package for equipment characterisation. The program calculates the excitation function at the sample position and the detector efficiency, supplying an internally consistent system. [Copyright &y& Elsevier]

Abstract: In the realm of X-ray fluorescence (XRF) applications, inhomogeneous distribution of an element can occur as a function of depth within a sample. An example is the measurement of arsenic in skin; arsenic binds with non-uniformly distributed keratin. In this paper, an XRF signal equation based on the fundamental parameter (FP) method, which explicitly takes into account the depth dependence of the elemental concentration, was developed. The formalism was experimentally verified for two-disc resin stacks with different arsenic concentrations. [Copyright &y& Elsevier]

Abstract: Three kinds of standard specimens, including low-alloy steels (Japanese iron and steel CRM), glass from NIST and Chinese geological reference materials were analyzed by wavelength dispersive X-ray fluorescence spectrometry as unknown samples. The fundamental parameter method was used to correct the matrix effect and different specimens including pure element specimens and type specimens were employed as calibration samples. The quantitative results were compared in order to study the influence of calibration samples on the accuracy of quantitative results. The study showed that the fundamental parameter method could correct the matrix effects very well and relatively accurate quantitative results could be obtained, corrected by simple specimens, in case of type calibration specimens’ absence. [Copyright &y& Elsevier]

Abstract: The shape of the continuous X-ray spectrum is approximated by the Planck’s distribution law for black-body radiation. The energy distribution of continuum X-rays produced by a bombardment of 30 kV electron beam onto a gold target is reproduced by the black-body radiation at a temperature of 107 K. The continuous spectrum measured when the incident electron energy varies in the range 30, 20, 10, and 5 kV, and for different target elements such as gold, iron, and carbon, are again reproduced in their absolute intensity scale. Consequently, it is speculated that the Stefan–Boltzmann''s law as well as the Wien''s displacement law also hold for the continuum X-ray radiation. [Copyright &y& Elsevier]

The full field X-ray fluorescence (FF-XRF) imaging is a technique capable of analysing the spatial distribution of elements in a sample. An alternative technique is the scanning macro-XRF method. Both techniques are powerful tools for non-destructive analysis of artworks mainly historical paintings. Technically, FF-XRF imaging is usually realised by coupling of a pinhole camera and a position sensitive and energy dispersive X-ray detector. The main advantages of the pinhole camera are its simplicity and infinite depth of field, however it introduces vignetting. For a visible light pinhole camera one distinguishes natural vignetting following the cos4 law and mechanical vignetting due to finite thickness of the camera. For an X-ray pinhole camera one has to take into account an additional component of vignetting due to absorption of X-rays in the air or other gas unless the setup is kept in vacuum. The goal of this study is to work out an analytical model of vignetting effects for a FF-XRF apparatus using an X-ray pinhole camera. Complete quantitative characterisation of the vignetting effects is a key step towards proper correction of the vignetting artefacts in recorded images. The elaborated analytical model has been applied to the images acquired with the FF-XRF apparatus being developed and an example of vignetting correction is presented. Unlabelled Image • Derivation of theoretical model of vignetting effects in full-field XRF (FF-XRF). • The model successfully validated by experiment. • The removal of the veignetting artefacts from FF-XRF images now possible. [ABSTRACT FROM AUTHOR]

Abstract: The continuous X-ray spectral profiles are compared with the Planck''s distribution law for blackbody radiation. The energy distributions of continuum X-rays produced by bombardments of 20 and 30kV electron beams onto iron target are crudely reproduced by the blackbody radiation at about 107 K temperature at their absolute intensity scale. [Copyright &y& Elsevier]

X-ray fluorescence (XRF) is a fast, low-cost, nondestructive, and truly multielement analytical technique. The objectives of this study are to quantify the amount of Na(+) and K(+) in samples of table salt (refined, marine, and light) and to compare three different methodologies of quantification using XRF. A fundamental parameter method revealed difficulties in quantifying accurately lighter elements (Z < 22). A univariate methodology based on peak area calibration is an attractive alternative, even though additional steps of data manipulation might consume some time. Quantifications were performed with good correlations for both Na (r = 0.974) and K (r = 0.992). A partial least-squares (PLS) regression method with five latent variables was very fast. Na(+) quantifications provided calibration errors lower than 16% and a correlation of 0.995. Of great concern was the observation of high Na(+) levels in low-sodium salts. The presented application may be performed in a fast and multielement fashion, in accordance with Green Chemistry specifications.