Photoelectron spectrometry is shown to be an excellent technique for the analysis of x rays in the ultrasoft and soft x-ray regions. X rays are converted into photoelectrons which are ejected from a suitable atomic level, and the photoelectrons are analyzed with an electron spectrometer. The method is energy dispersive, provides a resolution ranging from 0.1 eV at 20 eV to 1.1 eV at 3 keV, and gives well-defined intensity characteristics throughout the range. The energy range can be extended into the 10 keV decade. Properties of the new technique are discussed, compared with conventional techniques, and exemplified by a series of measurements which include determination of the emission spectra of M x rays of yttrium to rhodium, L x rays of zirconium, and the band structures of molybdenum and holmium.

The x-ray fluorescence (XRF) method is well known for its capability to perform fast and accurate quantitative analysis for all elements with atomic numbers greater than ten. Energy dispersive x-ray fluorescence (EDXRF) adds to this capability the benefit of quick qualitative analysis, due to its simultaneous sensitivity to all the elements. The method has the potential for rapid and complete chemical analysis of any sample which arrives on the analytical chemist's doorstep. Although the method has been a productive tool for fast and accurate repetitive analysis of similar samples, its applicability to unique unknowns has been rather limited. The limitation arises from the usual need to calibrate the instrument's response with a set of 6 to 12 standards, whose compositions must be similar to the unknown sample. Anyone who has struggled to develop and maintain such a suite of accurately certified standards knows that a great deal of effort and expense is involved. This effort is well justified when the analyst expects to analyze the same type of material frequently over an extended tine period. However, for a unique sample analysis, the task of developing a suite of similar standards simply makes the analysis impractical. What is needed is a method that requires minimal standards, or uses no standards at all.

When an x-ray diffraction profile Is measured for stress analysis or profile analysis by the use of a linear (straight line) position sensitive proportional counter (PSPC) , a convex-type background line is obtained because of the geometrical problem and the absorption of x-rays. Such phenomenon is remarkable when a wide angular range is set on a linear PSPC and it is, in particular, necessary to correct with a straight background for accurate measurement of diffraction angle or half-value breadth of the broadened diffraction profile.

Two new methods of comparison of lattice parameters are described. The first method uses a double crystal diffractometer, fitted with a specimen rotation stage. Bragg peak positions of a silicon reference and the specimen crystal are recorded for the crystals at 0 and rotated 180° about the diffraction vector. From the mean Bragg positions the lattice parameters can, in principle, be compared to parts in 106. The second method is a variant on the above, using a triple axis diffractometer. It uses a beam conditioner and monochromator to define the incident wavevector ko, and an analyser crystal to define the diffracted wave vector kh. Only the analyser motion must be accurate and stable to the arc second level. We present a detailed error analysis for the case where reference and specimen Bragg angles differ significantly. Peak location to a confidence level of 1 arc second permits absolute, traceable lattice parameter determination to several parts in 106.

Machine parts made of ceramics are usually finished by grinding. Residual stresses as well as defects introduced by grinding will influence the fracture strength and the function of the ceramic parts. Although several investigators measured the grinding residual stresses by the X-ray diffraction method, their grinding conditions were rather limited.

It is well-known that in EDXRF, using high-resolution semiconductor detectors, evaluation of x-ray fluorescence radiation line intensities from multiplex spectrometric information represents definite difficulties, especially in automation of measurement-calculation procedures.

A common spectrum decomposition problem is to get the following parameters: a number of spectral lines and their centroids, intensities from measured experimental data and their errors.

We have developed special software for solving this problem using personal computers and high-level programming language C. It uses profiles of real-form lines of pure chemical elements produced by semiconductor detector spectrometers and these techniques: digital filters with parameters for suppression of background, multiplex structure analysis, and stable linear least-squares fit to get peak intensities. Also it established special criteria for reliability of the results.

We compared our investigation with software “EDXRF” (ver.1.32) arid spectrum decomposition with Gaussian peaks.

A protocol for semi-quantitative XRD analysis of fly ash has been applied to 178 ashes in studies of the typical mineralogy of high-calcium and iow-calcium fly ash, the consistency of fly ash mineralogy from a typical power station, the partitioning of chemical constituents into crystalline phases, and the crystalline phases relevant to the use of fly ash in concrete.

The present study concerns residual stresses analysis in porycrystalhtie solar silicon material, which is continuously cast in a cold crucible. The observation of cracks and a modeling of thermal stresses suggest us that stresses in the center region are tensile and the ones in the peripheral region are compressive. X-ray measurement of stresses would be an experimental proof of the observations and an evaluation of the stresses levels. Unfortunately, the obtained material exhibits coarse grains with the size of up to one millimeter. In this case, where only a few crystals are irradiated by the incident X-ray beam, the classical sin2Ψ method is no longer valid. A specific analysis must be carried out. The results are of good accuracy comparing the low stress levels observed. The measured stress distribution on a radius of the billet is not always in good agreement with the analytical calculus.

The necessary first step in using an x-ray fluorescence spectrometer for quantitative analysis is to obtain the intensities for the various elements. With a wavelength dispersive system this usually requires simply setting the crystal to the proper angle (and possibly adjusting the pulse height selector) and making a dead-time correction. With the energy dispersive x-ray fluorescence analyzer it is necessary to take into account the presence of erroneous peaks in the spectrum, to obtain true intensity values.

False peaks due to diffraction of white tube radiation from the sample can usually be shifted to portions of the energy spectrum where they do not interfere with emission lines of interest by selection of the proper tube-sample-detector geometry. Modern amplifier design provides a built – in dead time correction and greatly reduces the effects of pulse-pile-up, although the latter phenomenon will still produce small peaks at exact multiples of major peaks.

Escape peaks occur when the incident X-ray quantum, energy exceeds the absorption edge energy of the detector element and the resulting X-ray fluorescence is lost from the detector. The most common escape peaks result from 1 K-fluorescence in NaI-scintillation counters and Xe K-, Xe L-, and Kr K-fluorescence in proportional counters. The average pulse amplitude of the escape peak is proportional to the difference of the Energies of the incident and fluorescent X-rays. If the intensity of the escape peak is high as in the case of Mo Kα and a kryptoopreportional counter, and the lower level of the pulse height analyzer is raised to reject the escape peak, the quantum counting efficiency may be reduced by a factor of two. When the pulse height analyzer is set for characteristic incident radiation, escape peaks appear in powder patterns at small diffraction angles. These broad low-intensity peaks are often mistakenly identified as resulting from misalignment, scattering, etc. Each powder reflection can produce its own escape peak which occurs at an angle slightly smaller than the absorption edge of the detector element. In a silicon powder pattern the three strongest reflections produce three resolved escape peaks whose peak intensities are about 4% of their corresponding Cu Kα peaks when the X-ray tube is operated at 50 kV. The escape peak intensities decrease with decreasing X-ray tube voltage and disappear when the voltage is lower than the absorption edge energy of the detector element. Absorption edge peaks observed without the upper level of the pulse height analyzer are similar in appearance, intensity, and diffraction angle to the escape peaks. In complex powder patterns the escape peak pattern is unresolved and may produce a number of very broad peaks.

Intermediate aluminum oxides (aluminas) have broad X-ray diffraction (XRD) peaks. Many of the phases have similar XRD patterns with overlapping of major peaks. To characterize a multi-component alumina mixture several regions of multiple overlapping peaks are examined. Each region is integrated to a single sum without regard for individual peaks. The integrated regions are applied to various ratio functions obtained from single component standards. By using an iterative technique, the functions converge to yield weight fractions for up to six alumina phases.

This paper corrects assumptions made by previous authors regarding the magnitude of the error in d-versus-sin2ѱ plots resulting from deviations of the sample surface from the focusing circle. The results show that the effect is not significant for ordinary residual stress measurements. This investigation has also shown that shapes in d-versus- sin2ѱ plots, similar to the sample curvature effect, may exist in samples with large residual stresses. Interpretation of the data should consider the magnitude of the apparent stress, which allows one to distinguish between apparent sample curvature effects and other causes.

Thin film samples represent ideal samples for analysis using X-ray fluorescence in that they tend to be flat, smooth and homogeneous. However, before a sample can be characterized using XRF, several questions must be answered.

A high-temperature crystal growth experiment produced discrete singlecrystal products of Allr and IrSi. The preparation, and examination of these phases is described within. This project is part of a materials compatibility study relating to radioisotopic heat sources. These heat sources are comprised of a PuO2 fuel pellet encapsulated in an Ir alloy containment shell. Thorium is introduced as an additive within the Ir to maintain ductility. Si and P are picked up inadvertently in the fuel processing. The compatibility of the heat sources with Al is of interest because of potential interactions with the Al alloy hardware associated with the heat source environment.

As a means for quantitative texture analysis, the crystallite orientation distribution function analysis has an important drawback: to bring ghosts as a consequence of the presence of a non-trivial kernel which consists of the spherical harmonics of odd order terms. In the spherical hamonic analysis, ghosts occur in the particular orientations by symmetry operation from the real orientation in accordance with the symmetry of the harmonics of even orders. For recovery of the odd order harmonics, the 9th-order generalized spherical harmonics are linearly combined and added to the orientation distribution function reconstructed from pole figures to a composite function. The coefficients of the linear combination are optimized to minimize the sum of negative values in the composite function. Reproducibility was simulated by using artificial pole figures of single or multiple component textures. Elimination of the ghosts is accompanied by increase in the height of real peak in the composite function of a single preferred orientation. Relative fractions of both major and minor textural components are reproduced with satisfactory fidelity In the simulation for analysis of multi-component textures.

The first in vivo x-ray fluorescence measurements of lead in bone used y-rays from a 57Co source to excite Pb K x-rays. Later systems used γ-rays from 109Cd to excite Pb K x-rays or polarized x-rays to excite Pb L x-rays. All three approaches involve an extremely low effective dose to the subject. Of the two K x-ray techniques, 109Cd is more precise and more flexible in choice of measurement site. Pb L x-ray fluorescence (L-XRF) effectively samples lead at bone surfaces, whereas Pb K x-ray fluorescence (K-XRF) samples through the bulk of a bone. Both the polarized L-XRF and 109Cd K-XRF achieve similar precision.

Renal mercury has recently been determined using a polarized x-ray source. Both renal and hepatic cadmium can be measured using polarized x-rays in conjunction with a Si(Li) detector. Platinum and gold have been measured both by radioisotopic source excitation and by using polarized x-rays, but the latter is to be preferred.

Applications of Pb K-XRF have shown that measured bone lead relates strongly to cumulative lead exposure. Secondly, biological half lives of lead in different bone types have been estimated from limited longitudinal data sets and from some cross sectional surveys. Thirdly, the effect of hone lead as an endogenous source of lead has been demonstrated and it has been shown that a majority of circulating blood lead can be mobilized from bone, rather than deriving from new exposure, in some retired lead workers.

Hematite (α-Fe2O3) powder compacts have been subjected to controlled, quantitative high pressure shock loading at peak pressures from 8-27 GPa and preserved for post shook analysis. The broadened x-ray diffraction peak profiles have been analyzed to determine the residual lattice strain and the coherent crystallite sizes. Maximum modification effects are observed near 17 GPa with strain values near 3 x 10-3 and size values near 200 Å suggesting annealing at higher shock pressure, resulting from the higher shock temperature.

The discovery of a very simple and useful relationship between the absorption coefficient of a particular element and the ratio of incoherent to coherent scattering by the sample containing the element is discussed. By measuring the absorption coefficients for a few elements in a few samples, absorption coefficients for many elements in an entire set of similar samples can be obtained.