bluuebunny/crossref_metadata_2025 huggingface dataset:
An Integrated System for Elemental X-Ray Analysis of Materials
Authors: Russ J.C. , Sandborg A.O. , Barnhart M.W. , Soderquist C.E. , Lichtinger R.W. , Walsh C.J.
Published: March 2019

The use of energy dispersive analysis of x-rays (EDAX method) is now well entrenched in the electron column field(l), where more scanning electron microscopes have been fitted with EDAX instrumentation than all of the conventional (wavelength-dispersive spectrometer) microprobes ever made. The principle advantage of the EDAX approach for the SEM user is the efficiency of detection, which permits its use at the low power levels of the SEM. In addition, the simultaneous analysis of the entire spectrum and the lack of focusing restrictions that permits analysis of rough samples are important advantages.
Improved Techniques of Lattice Parameter Measurements Using two X-Ray Beams
Authors: Kishino Seigo
Published: March 2019

Two kinds of improved techniques are described for precise measurement of lattice parameters with an accuracy of 1 ∼7x10-5, in both of which a differenoe of Bragg angles between two X-ray beams such as K α1 and K β1 is measured.

In the first technique, which was applied to relatively imperfect crystals such as gallium arsenide, gallium arsenide phosphide, and gallium phosphide, two different diffraction planes were utilized for two radiations such as CuK α1 and CuK β1 in order to reduce the difference of the Bragg angles to the order of several minutes of arc.

In the second technique, which was applied to a nearly perfect crystal such as silicon, a double crystal arrangement of parallel setting was used, where lattice parameter of the specimen was relatively measured in comparison with the one of the first crystal which was known beforehand.
Crystal Distortion Associated with Magnetic Ordering in Alpha Iron Oxide and Manganese Carbonate
Authors: McCain W. S. , Albright D. L.
Published: March 2019

The magnetic crystal disrortion of weakly ferromagnetic α-Fe2O3 was investigated by x-ray diffraction techniques. Here crystal distortion is taken as the temperature dependent changes of lattice constants and thermal expansion coefficients. Moreover, the oxygen position parameter and the carbon-oxygen distance of MnCO3 were determined.

The lattice constants and thermal expansion coefficients of α-Fe2O3 were measured from room temperature down to 243°K. The crystal distortion, as measured by the changes in lattice constants, thermal expansion coefficients and axial ratio, was found to be highly anisotropic. The co hexagonal lattice constant was influenced very slightly by magnetic distortion; it changed only by 0.01 percent between room temperature and the Morin temperature of 254°K. On the other hand, the ao lattice constant changes by 0.11 percent between room temperature and the Morin temperature. The thermal expansion coefficients of the lattice constants showed a similar contrast. The co coefficient was found to be independent of temperature from room temperature down to the Morin temperature. However, in the same temperature range, the ao coefficient showed an anomalous increase with decreasing temperature. In addition, the ao coefficient showed an infinite discontinuity at the Morin temperature.

The change in the axial ratio with temperature suggests that the net weak ferromagnetic moment of α-Fe2O3 reaches a maximum at 275°K.

The oxygen position parameter, x, in MnCO3 as determined from two reflections has a value of 0.2702 ± 0.001. The carbon-oxygen distance as calculated from the lattice constants and the oxygen position parameter is 1.29 ±0.002 Å. This value is another confirmation of the Pauling theory of the resonating carbonate structure.
X-Ray Diffraction Topography
Authors: Bonse U. K. , Hart M. , Newkirk J. B.
Published: March 2019

In recent years, a number of experimental X-ray diffraction techniques have been developed by which a topographical display of the microscopical defects in a crystal can be obtained. This brief review of the most useful of these techniques is intended to summarize the elements of the various methods and to compare their respective features and limitations. Contrary to microradiographic methods, in which image contrast is due entirely to variations in X-ray absorption from point to point in the specimen, X-ray diffraction topography is concerned with point-topoint variations in the directions or the intensities of X-rays that have been diffracted by crystals. From these variations the defect structure of the crystal may be examined. Methods that mainly measure local variations in the direction of the diffracted beam are useful for the detection of gross misorientations such as subgrains or grains (methods of Gui nier and Tennevin, Schulz, Weissmann). Intensity mapping methods are chiefly concerned with individual defects such as dislocations, stacking faults, etc. In both groups there are experimental arrangements with both Laue-case (transmission) and Bragg-case (back reflection) geometry.
A Comparison of Four Slit Apertures for Selected-Area Analysis with the X-Ray Secondary-Emission Spectrometer
Authors: Bertin Eugene P.
Published: March 2019

Four types of slit apertures—vertical, horizontal, inclined, and sirtgle-edge—for selected-area analysis with commercial X-ray secondary-emission (fluorescence) spectrometers are described, evaluated, and compared. The vertical and single-edge slits already have been described by the writer and Rizzo. The other two are described here for the first time. The vertical and horizontal slits are secondarybeam apertures; the other two lie in both the primary and secondary beams. AH the slits are mounted on the specimen drawer. No further modification of the spectrometer is required except replacement of the soller collimators with open tunnels or simple slits, and replacement of the flat crystal with a fixed-radius curved crystal to increase sensitivity. The accessories are inexpensive and can be made in even a modest machine shop. They can be installed on or removed from the spectrometer in about 5 min. The accessories are applicable ordy to linear selected areas where composition varies in the direction normal to but not along the line, for example, linear inclusions and sections of plated surfaces, diffusion couples, and interfaces. The four slits were evaluated and compared for resolution, sensitivity, and spectral-line width. Techniques for use, advantages, limitations, and means for improvement are discussed for each of the slits. The horizontal slit is of little value, but each of the others has features which permit analysis of very narrow selected areas for which pinhole apertures would not be sufficiently sensitive. Slit widths as narrow as 0,00012 in. (0.003 mm) have been used in favorable cases. The inclined slit, used with a pulse-height analyzer, is probably the most useful of the four apertures, combining high sensitivity, high resolution, and narrow spectral-line width.
Common Sources of Error in Electron Probe Microanalysis
Authors: Heinrich Kurt F. J.
Published: March 2019

In order to reduce the error of quantitative electron probe microanalysis, error sources in the preparation and measurement of specimens and standards must be minimized. These sources of error are described, and literature references for detailed study are given. A critical analysis is made of 150 analytical measurements of binary specimens previously discussed by Poole and Thomas. It is shown that the cases of serious errors reported by these authors are mainly due to poorly characterized or measured specimens and, in. some cases, to the omission of characteristic fluorescence corrections. If these sources of error are eliminated, a much more favorable error distribution can be obtained through relatively simple correction calculations. Further progress in quantitative micro probe analysis is dependent upon measurements under well-controlled conditions and standard materials of experimentally proven microhomogeneity and reliably determined composition.
X-Ray Spectrographs Analysis of Traces in Metals by Preconcentration Techniques
Authors: Davis C. M. , Burke Keith E. , Yanak M. M.
Published: March 2019

Chemical separation techniques with their roots in classical analysis have been highly developed since the turn of the century. During the last two decades, X-ray spectrography has proven to be a very acceptable method of analysis because of the relative ease and rapidity of measurement of the intensity of characteristic wavelengths, the ready knowledge of the precision of the measurement, the facility of automating the analysis, and the nondestructive nature of the method. When chemical separation techniques are combined with X-ray spectrography, the problem of matrix effects is eliminated and the element being analyzed is substantially concentrated, which affords a means of performing trace element analyses. Published examples of preconcentration followed by X-ray measurement both outside and in the field of metallurgy are cited.
Applications of a Portable Radioisotope X-Ray Fluorescence Spectrometer to Analysis of Minerals and Alloys*
Authors: Rhodes J. R. , Furuta T.
Published: March 2019

A portable, battery-operated X-ray fluorescence analyzer weighing 15 lb is described, consisting of a Nal(Tl) scintillation-counter probe and an electronic unit with a single-channel pulse-height analyzer and reversible scaler. Radioisotope X-ray sources are used for excitation of the sample and, where necessary, balanced filters for resolution of neighboring characteristic X-rays. Emphasis has been placed on designing and producing an instrument that is easy and convenient to operate in laboratory, factory, or field conditions and that can equally well be used to measure extended surfaces, such as rock faces, or finite samples in the form of powders, briquettes, or liquids. The feasibility of the following analyses has been studied by using for each determination the appropriate radioisotope source and filters: sulfur in coal; calcium and iron in cement raw mix; copper in copper ores; and vanadium, chromium, molybdenum, and tungsten in steels. Detection limits, based on counting statistics obtained in count times of 10 to 100 sec, range from 0.03% for copper in ores to 0.2% for sulfur in coal. Both matrix absorption and enhancement effects were encountered and were eliminated or reduced substantially by suitable choice of source energy, by the use of nomograms, or by semiempirical correction factors based on attenuation or scattering coefficients.
X-Ray Stress Measurement by the Single-Exposure Technique
Authors: Norton John T.
Published: March 2019

X-ray techniques employing film recording continue to play an important role in the routine determination of residual stresses in metals, particularly where heavy and bulky specimens are involved. The single-exposure technique in which the two diffraction patterns required are obtained simultaneously in a single X-ray exposure has several practical advantages over the more conventional two-exposure technique for many routine applications. Details of the method are discussed and an analysis is made of the factors influencing the reliability of the stress determination. An apparatus for stress measurement having some unique features is described and a practical application presented, illustrating the use of the single-exposure technique for the determination of the stress constant of a specimen of hardened steel. The specimen was subjected to a series of known stresses in bending, both in tension and compression. The measured diffraction-line displacements were plotted against the applied stress, and a line was fitted to the points by a least-squares calculation. From its slope, the stress constant was determined. The standard deviation of individual stress determinations from the “true” values given by the least-square line was calculated and was in excellent agreement with the value calculated from the errors of measurement. It is concluded that the single-exposure technique with its reduced time required for measurement and less demanding requirement of precise instrumental adjustment provides a reliable and practical method for many routine stress measurement applications.
A Simplified Method of Quantitating Preferred Orientation
Authors: Klenck Michael M.
Published: March 2019

Qualitative evaluation of preferred orientation in 10-rml Hastelloy N seamless tubing was carried out by obtaining conventional pole figures for several samples with the modified Schulz reflection technique. This established the texture as a (110)[112]. Quantitative determination of this texture was achieved for a large number of samples by a radial traverse of an azimuthally averaged (110) stereographic projection. This was accomplished with a Schulz goniometer by rotating the sample rapidly in its own plane while slowly varying the tilt angle ϕ. The first minimum observed in the resultant pattern approximates the pole density of the randomly oriented component of the sample. A scan obtained from a randomly oriented sample and suitably scaled to match pole density at these minima serves to distinguish the random from the oriented component of the sample. A ratio of the oriented to the random component as a function of the tilt angle ϕ is independent of the instrumental effects of defocusing and absorption. This ratio is proportional to the pole density of the oriented component since the pole density of the random component is a constant by definition. The same constant of proportionality yields a pole density of unity for the random component. Integrating the pole density for die random component over the surface of a reference sphere of unit radius gives the value 4π for the number of randomly oriented poles NR. The number of poles corresponding to the oriented component is obtained by evaluating the integral

In this equation, R(ϕ) is the ratio of the oriented to the random component, Φ is the tilt angle corresponding to the first minimum in the sample scan, and m is a multiplicity factor which compensates for integration over just one 110 face of each grain. Evaluation of this integral may be made by plotting it with the aid of a family of sine curves and measuring the area under the curve.

The per cent of volume of the oriented component is then calculated by the relationship

This method entails about 30min of an analyst's time and 40 to 120 min of machine time, depending on the grain size of the sample. Further information on the angular breadth of the texture may be obtained from the plot of the integrand. This technique is subject to the limitations that the material have a single texture and it must be possible tc prepare the specimens so that a suitably chosen pole figure contains a central concentration of poles which are delineated from other regions of pole concentration by a surrounding minimum in pole density. This is generally not too difficult in the case of sheet textures but requires that the specimen normal be parallel to ths fiber axis for a fiber texture.
Topotactical Relationships Between Hematite α-Fe2O3 and the Magnetite Fe3O4 which is Formed on it by Thermal Decomposition Under Low Oxygen Pressure
Authors: Baro Raymond , Moineau Hervé , Heizmann J. Julien
Published: March 2019

The present work was performed on natural monocrystals from Mexico. All crystals presented well-formed natural faces of indices (01.2), (01.4), (11.3), and (00.1). They were reduced to magnetite in a thermobalance by heating at 1200°C under a pressure of 10−3 torr. The techniques used in the present work were Laue reflection diagrams and pole figures. The magnetite formed on the hematite showed preferential orientations of three different types. The mutual orientations of the two oxides all present a common zone axis for the lattices formed by the oxygen ions.
Crystal Structure Analysis of Niobium-Doped Rutile Single Crystal
Authors: Niizeki Nobukazu
Published: March 2019

Determination of the atomic sites for the doped niobium atoms by the X-ray diffraction method has been undertaken to obtain the structural basis for the understanding of semiconductive behavior of crystals. Diffraction intensities were measured with spherical samples ground from the undoped and doped (4 mol. %) TiO2 single-crystal rods grown by the flame-fusion method. Measurements were carried out by an automatic single-crystal diffractometer and observed intensities were corrected for Lp and absorption factors. The total number of the independent (hk0) reflections was 45 with Mo Kα. radiation. Structure factors were calculated on the baiis of the following atomic arrangement: titanium at equipoint (2a) of space group P42/mnm, O at (4f) with x = 0.306, and an isoatomic temperature factor B = 0.70 were used. Reliability factor R for the undoped rutile was 0.037 without further refinement. For the doped crystal, an R-yalue of 0.053 was obtained for the substitutional model, where niobium was assumed to be at x = 0, y = 0. The R value was 0.125 for the interstitial model, where niobium was assumed to be at x = ½, y = 0. The difference Fourier map was obtained by subtracting the electron density distribution in a Fourier map of the undoped crystal from that ot the doped crystal. Since the intensity measurements were done only on a relative scale, the two Fourier maps were normalized so as to give an identical number of electrons under the oxygen peak. The resulting map revealed a small peak only at the location x = 0, y = 0. It could be concluded that niobium atoms enter the titanium sites substitutionally, at least in rather heavily doped crystals. Further work on the refinement of the doped structure is in progress.
Variation of Standards and Sampling Requirements for Complementary Analysis Methods
Authors: Skogerboe R. K.
Published: March 2019

The requirements imposed on the standards and samples used for any analytical technique are determined by the sample utilization characteristics of each technique as well as the purpose of the analysis. A practical comparison of said sample utilization characteristics for several analytical techniques will be examined to define limitations imposed on the standards/sampling aspects of analysis.
The Al FeBe4 Intermetallic Phase in Beryllium
Authors: Brower I. , Roberts E. C. , Bosworth T. J.
Published: March 2019

X-ray diffracfion analysis has been used to determine the nature and relative concentration of the phases present in diffusion welded joints of fairly high purity beryllium. The analyses were done in conjunction with the major objective of the work which was to correlate the types and amounts of phases in the weld joint with the weld processing variables.

The beryllium used contained less than one percent by weight of alloying elements. Those elements present in major amounts were aluminum, less than 0.10 weight percent (less than 0.033 atom percent)and iron, less than 0.15 weight percent (less than 0.023 atom percent).

A phase concentration technique was used to obtain the quantities of phases required for positive identification. X-ray powder patterns obtained from the residues provided detailed diffraction data of which those for the phase Al Fe Be4, are of particular interest. These data are compared with the findings of other research investigations.

Experimental procedures are discussed in detail and a summary of the test results in included.
The Effects of Self-Irradiation on the Lattice of 238 (80%)PuO2.III
Authors: Roof R. B.
Published: March 2019

The results of the fourth year of observations on the effects of self-irradiation on the lattice of 238(80%)PuO2 confirm the predictions derived from previous observations. Namely, the lattice constant continues to decrease with time but at a slower rate indicating an approach to equilibrium. Very small reductions are also noted in the half-width of the diffraction lines.
A Review of X-Ray Diffraction Methods for Diffusion Studies
Authors: Carpenter J. A. , Tenney D. R.
Published: March 2019

X-ray diffraction methods for studying solid-state diffusion are reviewed. Because of the lack of penetration, such methods are suited for diffusion zones spanning only a few microns. Most involve analyses of one, or more, (hkl) “band” of intensities spread in 2θ as a result of the corresponding lattice parameter spread associated with compositional inhomogeneities. Further, many are non-destructive, making it possible to follow the progression of diffusion with time in the same specimen.
An Experimental Evaluation of the Atomic Number Effect
Authors: Parobek L. , Brown J. D.
Published: March 2019

A method for measuring the atomic number effect is developed using a sandwich sample technique. The depth distributions of x-ray production, ϕ(ρz) curves, have been measured for a zinc tracer in aluminum, copper, silver and gold matrices at 30, 25, 20 and 15 keV. The ϕ(ρz) curves were measured using a Cambridge Microscan 5 in which the electron beam is normal to the sample surface and the x-ray take-off angle is 75°.

Samples of the low concentrations of copper (∼1 Weight %) in aluminum, nickel, silver and gold were prepared. For each alloy system (for example, Cu - Al), three different concentrations of copper were prepared. The intensity ratios from the sample to the pure element (standard) for each system have been plotted against concentration. At such low concentrations of copper the relation between this ratio and concentration is linear. The slopes of the curves have been compared to the equivalent factors obtained as ratios of the area under F(ρz) curves for aluminum, silver and gold to the area under F(ρz) curve for copper, respectively. The F(ρz) curves are obtained from ϕ(ρz) curves; F(ρz) = ϕ(ρz) exp(-μρz csc ψ) where μ is mass absorption coefficient.

Comparisons are made between these experimental data and the current methods of calculating the atomic number effect.
Observation of Dislocation in α-Arsenic Single Crystals by X-Ray Diffraction Topography*
Authors: Shetty M. N. , Taylor J. B. , Calvert L. D.
Published: March 2019

X-ray diffraction topographs were obtained from large arsenic single crystals. The camera employed copper Kα, radiation from a microfocus tube and an oscillating assembly of Soller slits limited the beam divergence. Reflections of the type (11) and (20) (primitive rhombohedral cell) were used to characterise dislocation Burgers vectors. The technique has been applied to arsenic single crystals grown from the vapour and from the melt. The majority of dislocations were found to belong to Burgers vectors <10>. Comparison has been made between dislocation etch pit patterns on (111) surfaces and X-ray topographs.
A New Method for Fourier Analysis of Shapes of X-Ray Peaks and its Application to Line Broadening and Integrated Intensity Measurements
Authors: Rothman R. L. , Cohen J. B.
Published: March 2019

A method of Fourier analysis of x-ray line broadening is presented whereby microstrain, incoherent particle size, and fault probability can be calculated using only first-order peaks. This method can thus be used in studies of catalysts, vapor- and electrodeposits or heavily textured specimens for which second-order peaks are too broad or weak, in cases where the effect of particle size is not the same for all orders of a peak, or for multiphase specimens where overlap of peaks sometimes occurs. Examples of deformed FCG and BCC metals and alloys are presented, with comparisons to the method of multiple orders.

One part of the procedure, first demonstrated by Pines and Sirenko, provides for reducing the effects of truncation on the Fourier coefficients. As a result, larger particle sizes can be analyzed and the integrated intensity can be determined more precisely. Application to determinations of volume fraction are given.
On-Site Determination of Ash in Coal Utilizing a Portable XRF Analyzer
Authors: Brown F. V. , Jones S. A.
Published: March 2019

The x-ray system used was a Columbia Scientific Industries Corporation Portable X-Ray Fluorescence Analyzer Minilab 700 with a ten millicurie curium 244 source. This source was chosen instead of the available 30mCi Pu-238 or the 30mCi Cm-244 source because it could be supplied under a general radioactivity materials license. The XRF analyzer could be powered by a variety of power supplies, either AC or DC. All data were evaluated and best curves were selected utilizing the Honeywell Time Sharing System. Programs from the statistical library were used with minor modifications.
A Comprehensive Alpha Coefficient Algorithm
Authors: Lachance G.R. , Claisse F.
Published: March 2019

An algorithm is proposed as a model that describes the intensity concentration relation over a wide concentration range in binary and more complex systems involving absorption and enhancement. All the influence coefficients can be determined from fundamental parameter equations. Terms containing product of two weight fractions are always negligible in pure absorption cases, are often negligible in absorption/weak enhancement cases and are necessary but small in strong absorption/strong enhancement situations.

Once the magnitude of the coefficients is known, the range of application of the one- or two-coefficient models can be established with certitude.
Application of the Pixe method in Atmospheric Aerosol Investigations
Authors: Orsini C. Q. , Bouéres L. C.
Published: March 2019

Investigations of Atmospheric Aerosol Systems (let us abbreviate AAS) have now spread to many laboratories around the world, mainly because of the important role they assume in the air pollution problem.

In most cases, the studies on AAS attempt to evaluate the so-called “size-distribution function”, through which the general behavior of such a system is commonly described.
Effect of Chemical State Upon Phosphorus-L2,3 Fluorescence Spectra
Authors: Taniguchi Kazuo
Published: March 2019

The P-L2,3 emission spectra of the phosphorus compounds were obtained using a secondary excitation. We found that the spectra depended upon the chemical state, the main peak of L2,3 emission spectra shifts to a higher energy, and the peak of intensity of higher energy increases with an increase of oxidation number. It should be noted that the phosphorous spectra of the phosphate anions scarcely reveal influences of the phosphate compounds, except that of H3PO4. We concluded that the spectral feature for the phosphorus compounds is influenced by the condition of surrounding atoms but is not influenced by the bond condition.
X-Ray Imaging
Authors: Gurker N.
Published: March 2019

Element mapping has been so far an analytical field covered by those investigation methods using a scanned particle beam on the excitation side of the specimen. These methods include localized interaction processes, as in the electron microprobe, secondary ion mass spectrometer and Auger electron spectrometer. On the other hand, methods which use a stationary radiation beam on the input side (non-localized interaction) usually give summarized information about the sample area (X-ray fluorescence spectrometry, photoelectron spectrometry, …). This paper deals with an approach to extending the application field of X-ray fluorescence analysis (XRFA) to element mapping. Fig. 1 shows the main components of the X-ray imaging system. Since modern SRF systems often work under computer control, the only additional hardware components of the system are a scanned sample holder and an X-ray source producing a line-shaped X-ray beam. The computer is usually not used for ease, speed or convenience of operation, but is used to generate the element image and process all the collected fluorescence data.
Inclination of Principal Residual Stress and the Direction of Cracking in Contact-Fatigued Ball Bearing Steel
Authors: Maeda Kikuo , Tsushima Noriyuki , Tokuda Masatoshi , Muro Hiroshi
Published: March 2019

Peeling is a surface fatigue failure of a roller bearing that consists of many shallow pits less than 10 pm in depth and cracks that link the pits. Peeling occurs rather easily on a smooth Surface when in contact with a rough surface under insufficient thickness of the lubricating oil film.

X-ray residual stress measurements on and under the contact surface after a peeling test revealed that the 2θ versus sin2ψ curve is not linear and that it curves depending upon the rolling contact condition and especially upon the existence of slip. Nonlinearity of the 2θ-sin2ψ) curve has been reported by Wakabayashi in a study of residual stress accompanying the grinding of soft steel and by Faninger in a study of residual stress due to rolling contact with annealed steel, but hot in the case of high hardness steel such as ball bearing steel. No complete explanation of this non-linearity has been made as yet.
The Generalisation and Refinement of the Vector Method for the Texture Analysis of Polycrystalline Materials
Authors: Ruer Daniel , Vadon Albert , Baro Raymond
Published: March 2019

A so-called “Vector Method” for the texture analysis of cubic materials was presented for the first time at this conference in 1976. Since then this method has been refined and applied successfully to non cubic-materials. It is shown in this paper that the Vector Method provides several advantages over series methods of texture analysis, the most important of which being the relatively small amount of experimental data which are needed for the determination of the entire crystallite orientation distribution.
Quantitative Phase Analysis of Synthetic Silicon Nitride by X-Ray Diffraction
Authors: Mencik Z. , Short M. A. , Peters C. R.
Published: March 2019

Synthetically prepared silicon nitride is one of the more promising ceramic materials for structural components of gas turbines. Typical material may contain a-silicon nitride, Si3N4 (which is believed to always contain oxygen and therefore, according to Grievson, Jack and Wild, is more properly written as Si11.5N15O0.5), β-silicon nitride, Si3N4, silicon oxynitride, Si2ON2, silicon metal, Si, and α-cristobalite, SiO2. Because the physical properties of the ceramic parts are dependent on their phase composition, it is essential that a technique be available for performing a phase analysis. An X-ray diffraction procedure has been, developed for the quantitative phase analysis of synthetically prepared silicon nitride. This procedure converts experimentally measured intensities of selected X-ray diffraction peaks to weight fractions of components using empirically determined intensity coefficients.
Spectral Analysis of X-Rays from Laser-Induced Plasmas†
Authors: Cuderman J. F. , Glibert K. M.
Published: March 2019

Laser interaction experiments have been conducted on Sandia Laboratories' four-beam laser system. In these experiments, pulses of 1.06 μm light of up to 50 J each were focused in a tetrahedral geometry onto CD2 microspheres. A 22-channel x-ray spectrometer which utilises silicon diodes with appropriate K-edge prefilters was used for x-ray measurements. Typically, bremsstrahlung-recombination spectra were observed in the photon regime below about 5 keV. The electron temperatures for this part of the spectrum ranged from a few hundred eV to 1 keV with up to 15 percent of the total laser energy converted to x-rays. Less than one percent of the total energy emitted as x-rays appeared in the spectral range above 5 keV.
Subnanosecond X-Ray Measurements Using a Unitary Organic Crystal and Image Converter Streak Camera
Authors: Nuttelman R. A. , Epstein H. M. , Beal J. W. , Mallozzi P. J.
Published: March 2019

A time dependent x-ray diagnostic technique based on the fast rise time characteristics of unitary crystals is demonstrated, and a correction for decay time is determined for anthracene crystals. The method has a probable time resolution capability better than 10 picoseconds. The shape of the x-ray pulse emitted by laser-generated plasmas is measured by this method and found to be similar to the shape of the laser pulse for laser pulse widths of 1.5-3.5 nanoseconds.
The Use of Photographic and X-Ray Films for X-Ray Measurements
Authors: Armistead R. A.
Published: March 2019

Experiments were conducted on two underground nuclear tests with the primary objective of determining if high-intensity x-ray exposures can cause a failure of the photographic reciprocity law. The results of the experiments, which included exposures at intensities up to 1020 photons/cm2-sec, were in good agreement with standard diagnostic experiments. Thus, these results show that films receiving x-ray exposures do not experience high-intensity reciprocity failure, and, in so doing confirm photographic theory on this point.

Measured latent-image regression curves and x-ray spectral sensitivity curves for commercially available films, obtained under laboratory-ambient condition and under a vacuum of 10−4 torr are presented. Anomalies in the film response are described, and the dependence of the response characteristics on the exposure environment and the emulsion characteristics is discussed. Suggestions are made for the use of films for x-ray measurements.
On-Line X-Ray Measurement and Control of Silver Emulsion Coating Weight
Authors: Severance W. A. N.
Published: March 2019

This paper describes the development of a radioisotope x-ray fluorescence gauge built to continuously measure and control the coating weight of wet silver emulsion. The method and apparatus for correcting the basic measurement for variations in water content and base film thickness are described. Design considerations, including source selection and arrangement to minimize radiation scattering and emulsion exposure while providing acceptable measurement precision or accuracy, are discussed.
X-Ray Fluorescence Analysis of Refractory Oxide Materials
Authors: Banerjee Subrata , Olsen Ben G.
Published: March 2019

In a refractory manufacturing industry with widely diversified products from silica (SiO2≥ 90%) to high alumina materials (Al2O3≥ 90%) and basic refractory from periclase (MgO ≥ 95%) to chrome-periclase (Cr2O3≤ 40%) mixtures, introduction of a single method of analysis is impractical both economically and precision-wise. Three different methods are proposed with a view to realistic needs: (a) Direct ratio method, (b) calibration curve ratio method, and (c) matrix normalization by fusing with Li2B4O7and La2O3into a glass bead followed by grinding and pelletizing. Statistical regression equations were used for the calibration curves from available NBS standards 15-20 samples previously analysed by wet chemical methods by ratioing with relevant reference samples. In most cases, the relative standard deviation was 2 - 8%.
Investigation of Elemental Analysis of Water Samples by Radioalpha Induced X-Ray Emission Spectroscopy*
Authors: Hight R. , Foster C. C.
Published: March 2019

Alpha particles and protons from charged particle accelerators and photons from both x-ray tubes and radioactive sources have been shown to be useful for the excitation of characteristic x-rays for multi-element energy dispersive trace analysis of environmental samples to the few ppm range. We have investigated the use of 4.5 MeV alpha particles from a thin window Po-210 source of 5 mCi effective strength to directly excite x-rays from trace elements in 1 cc water samples evaporated on 1.75 mg/cm2 thick mylar backings in a helium atmosphere in a lucite enclosure. Minimum detectable amounts (MDA's) were established for 19 elements (22 ≤ Z ≤ 82) using K-, L- and M- radiation and 50 minute counting times. The smallest MDA determined was 0.11 μg for vanadium. Other representative MDA's, in μg, are Fe-0.54, Mo-0.31 and Pb-0.43. MDA's lower by an average factor of about 10 over an eight month source life would result from the use of 1 Ci of Po-210 for 50 minutes per sample. Thinner sample backings and improved source encapsulation will reduce background radiation and further improve sensitivity. Comparison of our MDA's (5 mCi-Po-210) with those of Blasius et al., who used radiophoton sources and 40,000 sec. counting times to determine trace metal pollutants in water samples, shows radioalpha excitation to have comparable sensitivity in the worst case, arsenic and better, by more than two orders of magnitude, sensitivity in the best case, vanadium.

Radioalpha induced x-ray trace element analysis offers the same advantages of portability, ease of operation, low maintenance and cost, and "in house" availability as radiophoton induced analysis. Because of the availability of more intense sources (up to 10 Ci), the fact that the detected radiation (x-rays) differs from the excitation radiation (a-particles) and that K, L, and M x-ray emission cross-sections depend essentially only on the emitted x-ray energy, lower MDA's are obtainable for many elements in thin samples for comparable counting times, as well.
Non-Linear Least Squares Analysis of Proton-Induced X-Ray Emission Data
Authors: Kaufmann H. C. , Akselsson R.
Published: March 2019

A Fortran program for analysis of spectra obtained in proton induced x-ray emission spectroscopy is under development. The first version is working and some results are shown. The program uses a model which describes the physics involved in the analysis. The continuum is described by an exponentially decreasing function representing secondary electron induced bremsstrahlung and a constant approximating different Compton scattering processes. Absorption effects are also included. All parameters in the model are fitted simultaneously. About 100 test runs have been made with good results. The continuum was accurately fitted for each spectrum. Other advantages are reliability, speed, and the fact that the program is easily adaptable to a small computer with 16K memory.
An X-Ray Diffraction Study of Triglyceride Polymorphism
Authors: Zacharis H. M. , Mitcham D. , Lovegren N. , Gray M.
Published: March 2019

The polymorphism of an homologous series of highly purified mixed triglycerides has been studied using powder and single crystal X-ray diffraction techniques, in conjunction with thermal analysis and infrared spectroscopy. From thermal analysis, three polymorphs were identified. Single crystals of the most stable polymorph were obtained for two members of the series, 2-acetodimyristin (14-2-14) and 2-acetodipalmitin (16-2-16). Their unit-cell and sub-cell dimensions were used to interpret the powder data, and to provide preliminary general information about the crystal packing for this polymorph. Of the two other polymorphs identified, the first one (obtained by rapid cooling of the melt) is disordered, and transforms on standing, to a second, unstable intermediate polymorph. Infrared spectroscopy showed that for at least two of the three polymorphs, the long chain acyl groups of the triglycerides are in a parallel packing arrangement.
Environmental Monitoring Device for X-Ray Determination of Atmospheric Chlorine , Reactive Sulfur and Sulfur Dioxide
Authors: Lorenzen Jerry A.
Published: March 2019

A prototype Environmental Monitoring Device (EMD) has been developed as a simple means for inexpensive, routine determination of site severities. The EMD is a cartridge that can be connected to an inexpensive pumping unit to collect an atmospheric sample. The field procedures are extremely simple and have been done routinely by individuals with no chemical training. Four filters within the cartridge selectively react with and permanently trap pollutants from the air drawn through the cartridge. The first filter collects particulates. The second is o-tolidine impregnated Whatman #41 filter paper to collect gaseous chlorine species. Silver nitrate impregnated paper collects reactive sulfur gases, and the fourth filter paper is impregnated with sodium hydroxide to react with and collect sulfur dioxide. After atmospheric sampling, the cartridges are returned via mail to a central analytical lab. Procedures have been developed for easy and rapid determination of the quantities of pollutants on the filters by energy dispersive X-ray fluorescence. Laboratory and field measurements from a number of locations within the IBM Corporation have been made and will be reported. The EMD approach is providing a large data base on indoor atmospheric pollutants that could affect electronic equipment. The approach could easily be extended to numerous other applications.
Proton Elastic Scattering Analysis—A Complement to Proton-Induced X-Ray Emission Analysis of Aerosols
Authors: Nelson J. William , Meinert Dennis L.
Published: March 2019

Proton scattering quantitative elemental analysis is examined as a complement to proton induced X-ray emission analysis for air particulate samples. Both methods are absolute, non-destructive, and are suitable for use on samples up to about 1 mg/cm2 in areal density. Characteristics of the method are discussed and examples of aerosol spectra are presented.
An Area-Imaging Proportional Counter for X-Ray Diffraction
Authors: Desper C. Richard , Burns Ronald
Published: March 2019

Slow data acquisition rates have, in the past, limited the use of X-ray diffraction for characterization of polymeric materials. Photon counting techniques yield quantitative data in digital form for computer analysis. However, a great deal of data acquisition time is required when data is taken sequentially; i.e., when each intensity determination (at a particular goniometer setting) requires a separate time interval, during which intensity at other angle values is ignored. The problem is particularly acute for oriented polymers since two or more diffraction angles are involved: The Bragg angle along with at least one orientation angle. For this reason, an area-imaging (two-dimensional) proportional counter has been developed for use with a four-circle X-ray diffraction system. Although basically a single-crystal unit, this goniometer has been used in this laboratory and others for studies of oriented polymers. The receiving pinhole collimator and aperture have been removed, and the area-imaging counter has been mounted on the detector arm track. The original receiving aperture is still used for alignment, and the area detector Is positioned with its center at the receiving aperture center position.
Separation of Broad Crystalline and Amorphous X-Ray Diffraction Peaks
Authors: Marks O. W. , Smith D. K. , Chris M. D.
Published: March 2019

Separating overlapped peaks is a part of many x-ray diffraction analyses, for example, polymer crystallinity. Natta [1] defined a method for polypropylene in 1957. His method was computerized at the Hercules Research Center in 1960 with an automatic “curve follower” which punched paper tape for the computer. A later method deviated fTom Natta's method by approximating the amorphous curve with a fixed shape and a height chosen to best fit the diffraction data from 2θ = 7.5 through 10. degrees. Neither of these methods worked on “smectic” polymer samples, i.e., composed of very small crystallites. Also, a different computer program was used for each different polymer, so a general purpose computer program was developed using a peak profile method. This method has been used en polymer mixtures and copolymers of ethylene, propylene, and butene; and on cellulose, modified cellulose, and catalysts. The selection of a profile function is discussed in the next section. In later sections, the background, the fitting procedure, and computer input and output are discussed.
Application of Gandolfi X-Ray Diffraction to the Characterization of Reaction Products from the Alteration of Simulated Nuclear Wastes
Authors: Anderson C. A. F. , Zolensky M. E. , Smith D. K. , Freeborn W. P. , Scheetz B. E.
Published: March 2019

Accurate phase characterization of the alteration products of rad-waste requires the separation and identification of scattered individual grains from among the bulk product. These grains are typically 5 to 100 μm in size. Bulk x-ray powder diffraction will normally not detect these minor phases, and even if the phase can be detected, it often may not be identifiable. The use of the Gandolfi technique with the individual particle not only facilitates the identification, but also allows the assignment of the identification to the specific grain.
Applicability of U L X-Ray Likes for the Determination of Low Uranium Concentrations
Authors: Parus J. , Żółtowski T. , Kiersek J. , Ratyński W.
Published: March 2019

The determination of uranium in low grade ores, some industrial raw materials (e.g. phosphates) and industrial wastes (e.g. coal ashes) at concentrations below 200 ppm Is very important for various reasons, and poses a serious analytical problem. In these materials uranium is often accompanied by elements emitting K lines which interfere with the most intensive U Lα and U Lβ1 lines. The most serious interferences for U Lα lines are from Sr and Rb sometimes present in analysed materials in comparable or excessive quantities. Also Mo, Zr and Y can interfere.
Lead and Barium in Archaeological Roman Skeletons Measured by Nondestructive X-Ray Fluorescence Analysis
Authors: Ahlgren L. , Christoffersson J.-O. , Mattsson S.
Published: March 2019

Lead is a non-essential toxic metal of considerable topicality. It is accumulated in the skeleton, which contains 90% of the total body burden.

It is known that during the Roman period the intake of lead was high. The Romans used kitchen utensils made of lead and lead pipes for drinking water. The most important source of lead for people of the upper social classes was sapa, a compound added to wine to sweeten and perserve it.

Using non-destructive X-ray fluorescence analysis, lead and barium concentrations of archaeological Roman bones have been measured. We have earlier used a similar technique to determine lead concentration in the human skeleton in vivo.
Six Models for Interelement Correction in X-Ray Analysis
Authors: Marr H. E.
Published: March 2019

Simplified models are “being used, at the College Park Metallurgy Research Center for six popular methods for matrix correction in X-ray analysis, including Lachance-Traill, Lucas-Tooth and Pyne, and Rasberry-Heinrich procedures. A choice of models provides the broader data-handling capability required for processing information obtained by both energy-dispersive and wavelength-dispersive X-ray systems. The selection of model for each problem depends on the system and the availability of standard reference materials. Programming developed at College Park using the simplified models has been formulated for use by analytical chemists with minimal computer training. Some of the considerations involved in developing a versatile computer program for matrix correction will be presented, as well as applications of the procedures to iron-nickel-chromium alloys, aluminum alloys, and low-alloy steels.
A New Approach to Quantitative Multielement X-Ray Fluorescence Analysis
Authors: Chung Frank H.
Published: March 2019

A quantitative X-ray fluorescence method for single or multielement analysis is reported. It requires no calibration curve and covers a wide concentration range. The sample is dispersed into a film-forming polymer solution from which a thin specimen is made. A simple intensity-concentration equation free from matrix factors is derived. The simplicity and versatility of this method are demonstrated with eighteen examples. The precision of this method is statistically estimated to be 5% relative.
Application of the Solid State Detector in the X-Ray Fluorescence Analysis of Steel Products in Production Lines
Authors: Shiraiwa Toshio , Fujino Nobukatsu
Published: March 2019

The X-ray fluorescent analyzer for identification of every piece of steel product in the production line has. been developed and its accuracy and utility has teen ascertained from practical applications.

It has also been applied to thickness measurement of zinc coating and color coating on steel sheets in the coating lines. In the severe environment of steel works for four years, there has been no instrumental trouble, and the reliability of the analyzer has been confirmed.