Journal of Research of the National Institute of Standards and Technology articles from November 2002

Journal of Research of the National Institute of Standards and Technology archives from November 2002

Kurt Francis Joseph Heinrich.
November 1, 2002... We are dedicating this workshop to Kurt F. J. Heinrich at a most appropriate time; it honors Kurt's many contributions to the field of x-ray microanalysis made during the past 40 plus years, and it also honors him, though somewhat delayed, on...

Foreword.
November 1, 2002... Electron probe x-ray microanalysis (EPMA) is one of the oldest yet still one of the most widely applied methods of spatially-resolved elemental analysis. Implemented as electron-excited x-ray spectrometry performed in the scanning electron...

Terminology.(o)
November 1, 2002... Note: Terminology in This Special Issue. NIST's policy is to closely follow international guidelines in terminology for expressing both the uncertainties of measured quantities and the units of physical quantities. You might notice that...

Uncertainty in quantitative electron probe microanalysis.
November 1, 2002... Quantitative electron probe analysis is based on models based on the physics or x-ray generation, empirically adjusted to the analyses of specimens of known composition. Their accuracy can be estimated by applying them to a set of specimens of...

Accurate cross sections for microanalysis.
November 1, 2002... To calculate the intensity of x-ray emission in electron beam microanalysis requires a knowledge of the energy distribution of the electrons in the solid, the energy variation of the ionization cross section of the relevant subshell, the...

Optimization of wavelength dispersive x-ray spectrometry analysis conditions.
November 1, 2002... In setting up the conditions for quantitative wavelength-dispersive electron microprobe analysis a number of parameters have to be defined for each element, namely accelerating voltage, beam current, and (for each element) x-ray line,...

High count rate electron probe microanalysis.
November 1, 2002... Reducing the measurement uncertainty of quantitative analyses made using electron probe microanalyzers (EPMA) requires a careful study of the individual uncertainties from each definable step of the measurement. Those steps include measuring...

Decomposition of wavelength dispersive X-Ray spectra.
November 1, 2002... Line shapes of atomic lines and soft x-ray emission bands measured with a wavelength dispersive spectrometer (WDS) with the Electron Probe Micro Analyzer (EPMA) are reviewed. Least square fitting to pseudo-Voigt profiles of the digitally...

Limitations to accuracy in extracting characteristic line intensities from x-ray spectra.
November 1, 2002... The early development of quantitative electron probe microanalysis, first using crystal spectrometers, then energy dispersive x-ray spectrometers (EDXS), demonstrated that elements could be detected at 0.001 mass fraction level and major...

Averaging of backscatter intensities in compounds.
November 1, 2002... Low uncertainty measurements on pure element stable isotope pairs demonstrate that mass has no influence on the backscattering of electrons at typical electron microprobe energies. The traditional prediction of average backscatter intensities...

The analysis of particles at low accelerating voltages ([less than or equal to] 10 kV) with energy dispersive x-ray spectroscopy (EDS).
November 1, 2002... In recent years, there have been a series of advancements in electron beam instruments and x-ray detectors which may make it possible to improve significantly the quality of results from the quantitative electron-probe analysis of individual...

X-ray microanalysis in the variable pressure (environmental) scanning electron microscope.
November 1, 2002... Electron-excited x-ray microanalysis performed in the variable pressure and environmental scanning electron microscopes is subject to additional artifacts beyond those encountered in the conventional scanning electron microscope. Gas scattering...

Barriers to quantitative electron probe x-ray microanalysis for low voltage scanning electron microscopy.
November 1, 2002... Low voltage x-ray microanalysis, defined as being performed with an incident beam energy [less than or equal to]5 keV, can achieve spatial resolution, laterally and in depth, of 100 nm or less, depending on the exact selection of beam energy...

The microcalorimeter for industrial applications.
November 1, 2002... To achieve the dramatic increases in x-ray spectral resolution ( Key words: cryogen-free cooling; energy resolution; microcalorimeter energy dispersive; transition-edge sensor; x-ray microanalysis; x-ray spectrometer. 1. Introduction...

Sample preparation for electron probe microanalysis--pushing the limits.
November 1, 2002... There are two fundamental considerations in preparing samples for electron probe microanalysis (EPMA). The first one may seem obvious, but we often find it is overlooked. That is, the sample analyzed should be representative of the population...

Implications of polishing techniques in quantitative x-ray microanalysis.
November 1, 2002... Specimen preparation using abrasives results in surface and subsurface mechanical (stresses, strains), geometrical (roughness), chemical (contaminants, reaction products) and physical modifications (structure, texture, lattice defects). The...

Copper oxide precipitates in NBS Standard Reference Material 482.
November 1, 2002... Copper oxide has been detected in the copper containing alloys of NBS Standard Reference Material (SRM) 482. This occurrence is significant because it represents heterogeneity within a standard reference material that was certified to be...

Smithsonian Microbeam Standards.
November 1, 2002... This is a short history of the Smithsonian Microbeam Standards; their sources, selection, preparation, and analyses. Fifty-eight minerals, natural glasses, and synthetic samples have been characterized in the past 25 years. During that time,...

NIST standards for microanalysis and the certification process.
November 1, 2002... The National Institute of Standards and Technology (NIST) has been involved in the development of standards for microanalysis since the middle of the 1960s. Certification of "traceable" standards that can be sold to other laboratories is...

Contamination in the rare-earth element orthophosphate reference samples.(lead contamination in Oak Ridge National Laboratory samples from the 1980s)
November 1, 2002... Several of the fourteen rare-earth element (plus Sc and Y) orthophosphate standards grown at Oak Ridge National Laboratory in the 1980s and widely distributed by the Smithsonian Institution's Department of Mineral Sciences, are significantly...

Characterization of Corning EPMA standard glasses 951RV 951RW and 951RX.(trace-element glass analysis)
November 1, 2002... The preparation, synthesis, and characterization of Corning trace-element glasses 951RV, 951RW, and 951RX by bulk chemical and electron microprobe techniques is discussed. Working values for the doped elements in the 95-series glasses are...

Microbeam characterization of Corning archeological reference glasses: New additions to the Smithsonian microbeam standard collection.
November 1, 2002... An initial study of the minor element, trace element, and impurities in Corning archeological references glasses have been performed using three microbeam techniques: electron probe microanalysis (EMPMA), laser ablation ICP-mass spectrometry...