Calibration of wavelength-dispersive X-ray spectrometer for standardless analysis

The semi-quantitative analysis, which is called ‘Standardless Analysis’, plays a major role in X-ray fluorescent analysis, especially in the field of research and development. The main feature of the semi-quantitative analysis is the fact that the composition of a sample can be obtained directly from a qualitative scan without any prior knowledge of the sample.

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Importance of the relative x-ray line intensities

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100132819 ◽

1992 ◽

Vol 50 (2) ◽

pp. 1636-1637

Author(s):

János L. Lábár ◽

Charles E. Fiori ◽

Robert L. Myklebust

Keyword(s):

Rare Earth ◽

Energy Dispersive Spectrometry ◽

X Ray ◽

Line Intensities ◽

Elemental Concentrations ◽

Wavelength Dispersive Spectrometry ◽

Electron Microscopes ◽

Scanning Electron Microscopes ◽

Standardless Analysis ◽

Scanning Electron

Relative intensities of the non-analytical lines of an element (as compared to the analytical X-ray line of the same element) directly affect the accuracy of quantitative X-ray microanalysis. Correct spectral deconvolution can only be based on the knowledge of these relative intensities. Not even wavelength dispersive spectrometry (WDS) is free from spectral overlaps, making deconvolution of the X-ray lines necessary. A typical example for such a serious overlap can be the L line series of different rare-earth elements simultaneously present in the same sample. Energy dispersive spectrometry (EDS) is even more affected. Many EDS systems are equipped on scanning electron microscopes (SEM). Quick standardless analysis is frequently in use in these systems. Starting approximation of the elemental concentrations are based on computed "standard intensities" in contrast to measured ones in full quantitative analysis. Computation of the generated standard intensities directly contain the relative intensities of other lines too.

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The Use of Reference Intensity Ratios in X-Ray Quantitative Analysis

Powder Diffraction ◽

10.1017/s0885715600018686 ◽

1992 ◽

Vol 7 (4) ◽

pp. 186-193 ◽

Cited By ~ 116

Author(s):

Robert L. Snyder

Keyword(s):

Quantitative Analysis ◽

Standard Method ◽

Amorphous Material ◽

Internal Standard ◽

Rietveld Analysis ◽

Internal Standard Method ◽

X Ray ◽

Quantitative Results ◽

Matching Procedure ◽

Standardless Analysis

AbstractEach of the RIR based methods for carrying out quantitative X-ray powder diffraction analysis are described and a consistent set of notation is developed. The so called “standardless” analysis procedures are shown to be a special case of the internal-standard method of analysis where the normalizing assumption is used. All analytical methods, other than the Rietveld whole pattern matching procedure, require the use of explicitly measured standards, typically in the form of RIR values. However, if only semi-quantitative results can be tolerated, the standards may be obtained by using published RIR and relative intensity values. The exciting new techniques of whole pattern fitting and Rietveld constrained quantitative analysis are also described in RIR notation and shown also to be forms of the internal-standard method with the normalization assumption. The quantitative results obtained from Rietveld quantitative analysis are derived from computed standards in the form of computed, normalized, RIRN values. The normalization assumption in Rietveld analysis allows the exclusive use of computed standards and comes as close to a “standardless” analysis as one can achieve: relying on the absence of amorphous material and on the validity of the structural models. Relationships are given for obtaining quantitative analysis from these RIRN values obtainable from the least-squares scale factors.

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Thin film standardless analysis used in TEM asbestos EDS analysis

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100106892 ◽

1988 ◽

Vol 46 ◽

pp. 966-967

Author(s):

X. Li ◽

J. Xingxing ◽

W. Zi-qin ◽

R. J. Lee ◽

G. R. Dunmyre ◽

...

Keyword(s):

Thin Film ◽

Weight Percent ◽

Atomic Weight ◽

Fluorescence Yield ◽

Ionization Cross ◽

X Ray ◽

Asbestos Fibers ◽

Image Position ◽

X Ray Absorption ◽

Standardless Analysis

A thin film standardless analysis method, based on the Cliff-Loriner factor k, has been used to do quantitative x-ray analysis of asbestos fibers in the TEM. The results of the analysis of four minerals at 120 keV were close to the theoretical value. The ionization cross section Q has been revised experimentally to improve the analysis of asbestos.The Cliff-Lorimer factor has been used in TEM thin film analysis since 1975. The factor kAB is used in the following equation:CA/CB = kAB IA/IBwhere CA and CB is the weight percent of the elements A and B. The IA and IB are x-ray intensities corresponding to elements A and B. In this paper the calculated k values2 will be used for standardless quantitative analysis.In the thin film, when the effects of the backscattering electron, x-ray absorption, and secondary fluorescence are not considered, the x-ray intensity iswhere pt is the mass depth AA is the atomic weight of element A, W is the fluorescence yield, L is the ratio of the x-ray lines and T is the detector efficiency.

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Standardless Quantitative Electron-Excited X-ray Microanalysis by Energy-Dispersive Spectrometry: What Is Its Proper Role?

Microscopy and Microanalysis ◽

10.1017/s1431927698980564 ◽

1998 ◽

Vol 4 (6) ◽

pp. 585-597 ◽

Cited By ~ 28

Author(s):

Dale E. Newbury

Keyword(s):

First Principles ◽

Energy Dispersive Spectrometry ◽

Physical Models ◽

Metal Alloys ◽

Energy Dispersive ◽

X Ray ◽

Proper Role ◽

Error Distributions ◽

Quantitative Results ◽

Standardless Analysis

Electron beam X-ray microanalysis with semiconductor energy-dispersive spectrometry (EDS) performed with standards and calculated matrix corrections can yield quantitative results with a distribution such that 95% of analyses fall within ±5% relative for major and minor constituents. Standardless methods substitute calculations for the standard intensities, based either on physical models of X-ray generation and propagation (first principles) or on mathematical fits to remotely measured standards (fitted standards). Error distributions have been measured for three different standardless analysis procedures with a suite of microanalysis standards including metal alloys, glasses, minerals, ceramics, and stoichiometric compounds. For the first-principles standardless procedure, the error distribution placed 95% of analyses within ±50% relative, whereas for two commercial fitted standards procedures, the error distributions placed 95% of analyses within ±25% relative. The implication of these error distributions for the accuracy of analytical results is considered, and recommendations for the use of standardless analysis are given.

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Space and Time Distribution of Hard X-Ray Emission in a Loop at the Beginning of a Flare

International Astronomical Union Colloquium ◽

10.1017/s0252921100025446 ◽

1994 ◽

Vol 144 ◽

pp. 275-277

Author(s):

M. Karlický ◽

J. C. Hénoux

Keyword(s):

Time Distribution ◽

Electron Bombardment ◽

Spatial Evolution ◽

Superthermal Electrons ◽

Flare Loop ◽

X Ray ◽

Superthermal Electron ◽

Flare Loops ◽

Chromospheric Evaporation ◽

Temporal And Spatial

AbstractUsing a new ID hybrid model of the electron bombardment in flare loops, we study not only the evolution of densities, plasma velocities and temperatures in the loop, but also the temporal and spatial evolution of hard X-ray emission. In the present paper a continuous bombardment by electrons isotropically accelerated at the top of flare loop with a power-law injection distribution function is considered. The computations include the effects of the return-current that reduces significantly the depth of the chromospheric layer which is evaporated. The present modelling is made with superthermal electron parameters corresponding to the classical resistivity regime for an input energy flux of superthermal electrons of 109erg cm−2s−1. It was found that due to the electron bombardment the two chromospheric evaporation waves are generated at both feet of the loop and they propagate up to the top, where they collide and cause temporary density and hard X-ray enhancements.

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Some Problems in Understanding the Solar Corona

International Astronomical Union Colloquium ◽

10.1017/s025292110002491x ◽

1994 ◽

Vol 144 ◽

pp. 1-9

Author(s):

A. H. Gabriel

Keyword(s):

Solar Corona ◽

Solar Atmosphere ◽

Theoretical Modelling ◽

Total System ◽

Major Advance ◽

X Ray ◽

Proper Perspective ◽

Space Observations

The development of the physics of the solar atmosphere during the last 50 years has been greatly influenced by the increasing capability of observations made from space. Access to images and spectra of the hotter plasma in the UV, XUV and X-ray regions provided a major advance over the few coronal forbidden lines seen in the visible and enabled the cooler chromospheric and photospheric plasma to be seen in its proper perspective, as part of a total system. In this way space observations have stimulated new and important advances, not only in space but also in ground-based observations and theoretical modelling, so that today we find a well-balanced harmony between the three techniques.

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White-Light Coronal Structures: Streamers and CMEs

International Astronomical Union Colloquium ◽

10.1017/s0252921100025045 ◽

1994 ◽

Vol 144 ◽

pp. 82

Author(s):

E. Hildner

Keyword(s):

Emission Line ◽

Electron Density ◽

White Light ◽

Coronal Mass Ejections ◽

X Rays ◽

Solar Cycles ◽

Temperature Function ◽

X Ray ◽

Eclipse Observations ◽

Coronal Structures

AbstractOver the last twenty years, orbiting coronagraphs have vastly increased the amount of observational material for the whitelight corona. Spanning almost two solar cycles, and augmented by ground-based K-coronameter, emission-line, and eclipse observations, these data allow us to assess,inter alia: the typical and atypical behavior of the corona; how the corona evolves on time scales from minutes to a decade; and (in some respects) the relation between photospheric, coronal, and interplanetary features. This talk will review recent results on these three topics. A remark or two will attempt to relate the whitelight corona between 1.5 and 6 R⊙to the corona seen at lower altitudes in soft X-rays (e.g., with Yohkoh). The whitelight emission depends only on integrated electron density independent of temperature, whereas the soft X-ray emission depends upon the integral of electron density squared times a temperature function. The properties of coronal mass ejections (CMEs) will be reviewed briefly and their relationships to other solar and interplanetary phenomena will be noted.

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Iron K-Line Emission from X-Ray Binaries

International Astronomical Union Colloquium ◽

10.1017/s0252921100107389 ◽

1988 ◽

Vol 102 ◽

pp. 47-50

Author(s):

K. Masai ◽

S. Hayakawa ◽

F. Nagase

Keyword(s):

Accretion Disk ◽

Radiative Recombination ◽

Characteristic Temperature ◽

Line Emission ◽

Ionization Front ◽

Continuum Radiation ◽

X Ray ◽

Low Mass ◽

X Ray Binaries

AbstractEmission mechanisms of the iron Kα-lines in X-ray binaries are discussed in relation with the characteristic temperature Txof continuum radiation thereof. The 6.7 keV line is ascribed to radiative recombination followed by cascades in a corona of ∼ 100 eV formed above the accretion disk. This mechanism is attained for Tx≲ 10 keV as observed for low mass X-ray binaries. The 6.4 keV line observed for binary X-ray pulsars with Tx> 10 keV is likely due to fluorescence outside the He II ionization front.

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Diagnostics of Gold Laser Plasmas

International Astronomical Union Colloquium ◽

10.1017/s0252921100108085 ◽

1988 ◽

Vol 102 ◽

pp. 357-360

Author(s):

J.C. Gauthier ◽

J.P. Geindre ◽

P. Monier ◽

C. Chenais-Popovics ◽

N. Tragin ◽

...

Keyword(s):

Experimental Results ◽

Pure Gold ◽

Electronic Temperature ◽

X Ray ◽

Laser Plasmas ◽

Collisional Radiative Model ◽

Radiative Model

AbstractIn order to achieve a nickel-like X ray laser scheme we need a tool to determine the parameters which characterise the high-Z plasma. The aim of this work is to study gold laser plasmas and to compare experimental results to a collisional-radiative model which describes nickel-like ions. The electronic temperature and density are measured by the emission of an aluminium tracer. They are compared to the predictions of the nickel-like model for pure gold. The results show that the density and temperature can be estimated in a pure gold plasma.

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