bluuebunny/crossref_metadata_2025 huggingface dataset:
Particle Size Effects in Radioisotope X-Ray Spectrometry
Authors: Berry P. F. , Furuta T. , Rhodes J. R.
Published: March 2019

Theories explaining the dependence of characteristic X-ray intensity on particle size in heterogeneous materials are reviewed. Several discrepancies between the theories and between theory and experiment have been discovered. A new theory is proposed based on a more rigorous physical model. It is shown to explain well-established phenomena at least as precisely as do previous formulae. Excellent agreement is also obtained with new observations of the variation of characteristic X-ray intensity with packing degree and, in samples consisting of only one type of particle, with both packing degree and particle size. The same basic theory also predicts the observed variation of X-ray Intensity backscattered from or transmitted through a sample. It is also shown that similar results are obtained with particles suspended In a homogeneous matrix, such as an aqueous slurry.
Applications of a New Multielement Portable X-Ray Spectrometer to Materials Analysis
Authors: von Alfthan C. , Rautala P. , Rhodes J. R.
Published: March 2019

A new hand-portable, microprocessor-based, multielement X-ray fluorescence analyzer is described. The instrument is light in weight (19 1b), completely self-contained and powered by internal rechargeable batteries. The detector is a special proportional counter whose room temperature energy resolution is sufficient to enable adjacent element X-rays to be deconvoluted with the help of the microprocessor. The instrument yields concentration readout of elements, corrected for matrix effects, in groups of four at a time. A number of field and laboratory applications to ore, solution and alloy analysis are described.
Energy Dispersive X-Ray Fluorescence (EDXRF) Analysis as a Reliable Nondestructive Industrial Tool
Authors: Miller L. E. , Abplanalp H. J.
Published: March 2019

For the past several years the Boeing Aerospace Company has been implementing advanced nondestructive chemical analysis methods to improve product reliability and reduce material inspection costs. Previous testing of incoming material for conformance to vendor test reports or of production materials for verification of alloy composition, had consisted of either time-consuming destructive testing or nondestructive chemical spot testing, which often was insensitive to differences between alloys of similar chemical properties. Beginning in 1974, development of EDXRF techniques was initiated to provide a rapid nondestructive analysis capability for both laboratory and factory use. For materials containing elements easily excited by EDXRF methods, costly destructive sampling and testing can be avoided. Generally, chips, wire, barstock, sheet or plate can be analyzed using an annular radioactive source. The uniformity of the X-ray flux diminishes sample geometry and surface roughness effects.
The Search-Match Problem
Authors: Nichols Monte C. , Johnson Quintin
Published: March 2019

Identification or recognition of an unknown is a problem encountered in areas as diverse as X-ray diffraction, signature and voice verification, fingerprint identification, and spectroscopy(mass), infared(IR), ultraviolat(UV), Auger). Features uniquely characteristic of the unknown, which are used in the identification process, are called the “pattern” of that unknown. In a typical identification, the one or more sub-patterns (components) making up the unknown pattern are identified by a search through a set of known (standard) patterns to yield potential matches. This searching and matching can be done sucessfully by hand, especially if the number of patterns in the file of standards is not too great. When the number of phases which consititute the unknown pattern becomes extremely large the use of computers becomes a practical necessity if the search is to be conducted in a reasonable time. A comparison of X-ray search-match approaches with each other and with search-match capabilities existing in other fields may lead to better X-ray phase identification techniques.
A Minicomputer and Methodology for X-Ray Analysis
Authors: Parrish W. , Ayers G. L. , Huang T. C.
Published: March 2019

This paper outlines the use of an IBM Series/1 small computer for instrument automation and data reduction for X-ray polycrystalline diffractometry and wavelength dispersive X-ray fluorescence spectrometry. The profile fitting method is used to determine 2θ, d and relative peak and integrated intensities in diffraction, and the fundamental parameters method (LAMA program) is used for quantitative analysis of bulk and thin film samples. The methods are precise and rapid.
Techniques of Low Energy X-Ray Spectroscopy (0.1 to 2 keV Region)
Authors: Henke Burton L. , Tester Murray A.
Published: March 2019

Presented here is a report on the development of practical techniques for laboratory spectroscopy in the 5 to 150 A wavelength region as may be applied, for example, to light element and surface state analysis, high temperature plasma diagnostics and to the design and calibration of x-ray astronomy measurements.
Soft X-Ray Vacuum Ultraviolet Diagnostics of High Density, High Temperature Plasmas at the Air Force Weapons Laboratory
Authors: Burns Erskine J. T.
Published: March 2019

Soft X-ray, vacuum ultraviolet diagnostics of high temperature, high density plasmas are used to determine the temporal, spatial, spectral and total fluence of radiation emitted from plasmas. Some of the radiation diagnostics used to characterize these plasmas are: metallic photocathodes with thin anodes; Ross filter - PIN detector combination; time-resolved pinhole cameras; metallic calorimeter; bent crystal and grazing incidence spectrographs; and differentially pumped, windowless, Samson-type ionization chambers.
Sub-Kilovolt X-Ray Calibration of Photographic Film
Authors: Koppel Louis N.
Published: March 2019

The x-ray spectroscopy of laser-generated plasmas can be applied to photon energies of less than 1 keV, provided calibrations of the response of energy discriminators and detectors are performed in the sub-kilovolt region. In our application we use photographic film to monitor the intensity of radiation dispersed by a curved lead stearate crystal. We have determined the response to sub-kilovolt x-rays of two types of film, Kodak No-Screen and the special vacuum ultra-violet Kodak type 101-01. This calibration was obtained by exposing samples of film to continuous beams of nearly monochromatic characteristic radiation from an array of targets. The fluorescent radiations were the K series of carbon and magnesium and the L series of titanium, nickel, cobalt and copper. The response data are presented as a series of characteristic curves, plotting for each film type and photon energy the net diffuse photographic density as a function of the photon flux incident on the film. The processing of all film was in accordance with the manufacturer's suggestions. We attempt to characterize the accuracy and reproducibility of these data. The data demonstrate the greater sensitivity of the type 101-01 to sub-kilovolt x-rays.

The intensity and spectral purity of the incident fluorescent beams were monitored by a thin-window gas proportional counter that used flowing propane gas at sub-atmospheric pressures. We describe the procedures and results of a determination of the quantum efficiency of this counter as a function of photon energy.
X-Ray Analysis for Electron Beam Enhancement in the Plasma Focus Device*
Authors: Gullickson R. L. , Barlett R. H.
Published: March 2019

The plasma focus device, a form of linear pinch discharge, produces an intense x-ray and neutron (D2) burst from a magnetically heated dense plasma. Rapidly changing magnetic fields at pinch time generate large axial electric fields which accelerate electrons and ions. In the experiments reported here the x-ray production during the plasma pinch of a 96 kilojoule (at 20 kV) plasma focus device was measured.

The purpose of these experiments was to evaluate the energy in accelerated electrons in the plasma focus device and to learn how to enhance these electron hursts. Well focused, megampere electron beams at a few hundred kilovolts, lasting less than 10 nanoseconds have applications in fusionable pellet heating experiments. (1) X-rays were monitored to evaluate these electron bursts using a defocusing bent crystal spectrometer, doubly diffused silicon (PIN) detectors, with Ross filters, thermoluminescent dosimeters (TLDs) with filters, and x-ray pinhole photography.

Thermoluminescent dosimeters indicated maximum x-ray yields of 140 joules above 3 keV at 57.3 kilojoules stored energy (16 kV) for a conversion efficiency to x-rays of 0.2%. 40 joules are above 60 keV and 15 joules above 80 keV. The hard x-ray pulse typically rises in 3 ns and frequently has a pulse width less than 10 ns. The low energy x-ray spectrum consists almost entirely of lines from the high Z anode insert, and the high energy spectrum is characteristic of a nonthermal power law distribution with an exponent of 2.2 ± 0.8. Peak hard x-ray production is obtained at 1 torr deuterium in contrast to peak neutron production (3 x 1010) at 5 torr. The addition of argon reduces total x-ray yield and increases the relative fraction of soft x-rays.

These measurements suggest that the plasma focus produces 1200 joules of electrons with an average energy of 150 keV, in 10 nanoseconds with a stored energy of 57.3 kilojoules. This is a power of 1.2 × 1011 watts and power density of 1.5 × 1013 watts cm−2.
Silicon Detector System for X-Ray Pulse Calorimetry of Laser-Produced Plasmas*
Authors: McQuaid J. H. , Violet C. E. , Petruzzi J.
Published: March 2019

The instrumentation for measuring x-ray yields from laser produced plasma is described. This new type of calorimeter is composed of a silicon detector, a charge-sensitive preamplifier and an analog-to-digital readout scheme for multiplexing up to ten detector outputs.

X-rays interacting with the detector produce hole-electron pairs in proportion to the total energy lost in the detector (∼1012 eV). In this application the detector can be characterized as a solid-state ionization chamber. The detector signal is coupled to a charge-sensitive preamplifier which generates a voltage pulse proportional to the x-ray energy absorbed. In this way the x-ray energy is measured by “direct conversion” rather than measuring the temperature rise due to an energy flux.
Chemical State Analyses of Sulfur, Chromium and Tin by High Resolution X-Ray Spectrometry
Authors: Gohshi Y. , Hirao O. , Suzuki I.
Published: March 2019

Chemical shifts of SKα, CrKβ1,3 and SnLβ2 were precisely measured with a two-crystal X-ray spectrometer (Toshiba AFV 701). Sulfur in the coke for iron smelting takes two oxidation states, i.e., S2− and S6+. Quantitative analyses of S2− and S6+ were performed by precisely measuring the profile of SKα and fitting the standard S2− of S6+ curve to the observed SKα profile with the non-linear least square method. Chemical shifts of CrKβ1,3 and SnLβ2 were utilized for the determinations of Cr6+, Cr3+, Sn4+ and Sn2+ in electro-plating solutions. Intensity ratio of IA to Ig was measured, where B means the point which showed an intensity independent of oxidation states. A means the point which showed the most dependent. Linear relations were found between intensity ratio IA/IB and Cr3+/Cr or Sn2+/Sn.
Excitation-Energy-Dependent Resonances in Soft X-Ray Appearance Potential Spectra of the Cerium 4d- and 3d-Electron Levels
Authors: Chamberlain M. B. , Baun W. L.
Published: March 2019

When the excitation energy lies near the ionization potential of many core electrons, core-hole relaxation effects strongly affect x-ray emissions. Under near-threshold electron excitation of the cerium 4d subshell both the incident electron and a 4d-core electron are promoted into 4f-orbital excitation states which exist only during the life of and are bound to the 4d vacancy. The exchange interaction between the 4d hole and the excited electrons in the unfilled 4f subshe11 spreads the energies of the discrete excitation states over a 20eV range sending some levels well below the 4d threshold and others into the continuum. Exchange interactions and potential barrier effects have a dominant influence upon the cerium 4d and 3d soft x-ray appearance potential spectra reported in this paper. We observe sub-threshold x rays extending to 8.6eV below the binding energy of the 4d level as well as a maximum in the yield at 12eV above the 4d onset. As the electron excitation energy is swept through the thresholds of the two 3d levels we observe resonant x-ray emissions, while at 28eV above these levels we see plasmon loss structures.
Anomalies in Measurement of Residual Stress by X-Ray Diffraction
Authors: Marion R. H. , Cohen J. B.
Published: March 2019

Residual stresses are expected to lead to a linear dependence of the interplanar spacing, d, on sin2ψ (where ψ is the sample tilt) and the stress can be obtained from the slope of this line, As a result of the linear dependence a two-tilt method is often employed to obtain the stress. However, when a specimen is subjected to extensive plastic deformation large deviations from a straight line can occur and a two-point method can lead to an erroneous stress determination. The results reported here show that: (1) this is more likely to occur in homogeneous materials than in multiphase materials (2) the oscillations follow closely the variation in peak intensity due to texture (3) the oscillations are caused by microstresses which are due to an "orientation" effect as suggested by Weidemann,

A simple, easy-to-use procedure has been developed and tested to correct the data and obtain the correct macrostress.
X-Ray Analysis of Ti3Al Precipitation in Ti-Al Alloys
Authors: Baggerly R. G.
Published: March 2019

The effect of temperature on nucleation and growth of Ti3Al precipitates in two Ti-Al alloys was determined using sensitive X-ray diffraction techniques. The X-ray peaks arising from the ordered Ti3Al phase were compared with the fundamental peaks of the matrix. Peak broadening due to particle size resulted from the small Ti3Al precipitates and this was analysed using Fourier methods to determine a mean particle size and particle size distribution. The two alloys used for this investigation were Ti-8.5 wt.% Al and Ti-8%Al-1%Mo-1%V (8-1-1) alloy. The precipitate size in Ti-8.5 wt% Al was considerably more dependent on temperature than the precipitate size in 8-1-1 alloy, achieving a size of 190Å after 20 hrs at 650°C. The solvus temperature for precipitation was the same for both alloys, vis, 675°C to 700°C. These results compare favorably with transmission electron microscopy of thin foils prepared from the same samples.
A New Model of X-Ray Position Sensitive Detector Developed in France
Authors: Castex Louis , Lebrun Jean Lou , Bras Serge
Published: March 2019

Since 1973 X-ray position sensitive detectors (P.S.D.) have been employed for stress analysis. The first models, based on the gas flow of Ar-CH4, were composed of a quartz fiber anode (20 um diameter), coated by a thin carbon layer. From 1975 the gas filling has become permanent. Hence the use of fiber P.S.D. (F-P.S.D.) was made easier; nevertheless, two important inconveniences remained. On the one hand, an intensive X-ray beam could destroy rapidly and locally the carbon film, which makes the detector malfunction; on the other hand, the pulse height analysis (P.H.A.), carried out in 1976, has proved to be ineffectual because of the design of the F-P.S.D. itself: its fiber impedance does not remain constant. Thus the appearnace, in 1979, of a new P.S.D. with a metallic wire (W-P.S.D.) presented a significant advantage (see Fig. 1). The anode—made of tungsten or molybdenum Gilded--can resist intensive X-ray beams perfectly. Hence the life of the detector is only limited by a possible ionization of the filling gas, which approximately corresponds to 1012 counts. A gas refilling--which will be provided in the standard equipment--allows us to use the detector again.
Stress Measurement in Stainless Steel by use of Monochromatic Cr-Kβ X-Rays and a Position Sensitive Detector
Authors: Yoshioka Yasuo , Hasegawa Ken-ichi , Mochiki Koh-ichi
Published: March 2019

X-ray stress analysis in austenltic stainless steel is generally carried out on the ϒFe(311) diffraction line produced by Cr- Kβ X-rays. However, it is often pointed out that not much reliance can be placed on the precision of the stress because the contrast between a diffraction peak and its background is poor. In addition, to measure the stress is sometimes impossible on a specimen which has martensite structure produced by thes train induced transformation, because the ϒFe(211) line appears in the neighborhood of the desired ϒFe(311) line, since Cr-K6 X-rays accompany Cr-Ka from a conventional X-ray source. If Cr-Ka X-rays can be eliminated and only Cr-KB X-rays directed on the specimen, only the λe(311) line with high contrast will be obtained and one can expect to measure the residual stress with high precision.
X-Ray Spectrometer for EXAFS Using a Position Sensitive Detector
Authors: Taniguchi K. , Oka K. , Yamaki N. , Ikeda S.
Published: March 2019

An active recording x-ray crystal spectrometer for extended x-ray absorption fine structure (EXAFS) has been built using a position sensitive detector of the self scanning photodiode array (SSPA) type. The SSPA detector has energy and position sensitivity for x-rays. The spectrometer was applied to the measurement for EXAFS of the several compounds in foil, powder and liquid states. The spectra can be obtained rapidly, and compare very well with other methods. We found that the SSPA detector is very useful for the measurement of EXAFS.
X-Ray Stress Measurements in Ground Surface of Steel by Position Sensitive Detector
Authors: Kawata M. , Morinaga M. , Yoshioka Y.
Published: March 2019

The residual stress produced by surface and cylindrical grinding was measured by a position sensitive proportional counter. In medium carbon steels the residual stress depends largely on the grinding conditions. For a gentle cylindrical grinding compressive stress was observed, but for a rough grinding tensile stress was present in the workpiece.
Measurement of Cumulative Fatigue Damage by X-Ray Double-Crystal and Scanning Diffraction Methods
Authors: Pangborn R. N. , Weissmann S. , Kramer L. R.
Published: March 2019

The ability to predict fatigue failure has long eluded scientists and engineers. Because they can be applied nondestructively, X-ray diffraction methods have been employed to measure fatigue induced lattice misorientation, lattice strain, residual stress and subgrain formation. The changes in the X-ray patterns, however, were found to be restricted principally to the very early and late fractions of the fatigue life. Their invariance during the intermediate portion of the life has hampered the evaluation of cumulative fatigue damage and prediction of ultimate failure.

The primary difference between previous investigations and our recent X-ray diffraction studies is the emphasis we placed on characterizing both the surface and subsurface response to fatigue. By evaluating the prefracture damage with depth from the specimen surface a more reliable procedure for failure estimation emerged.
Compression and Compressibility Studies of Plutonium and a Plutonium-Gallium Alloy
Authors: Roof R. B.
Published: March 2019

Two metal foils, one pure plutonium and the other being a solid solution of 6.5 a/o gallium In plutonium, were examined, in-situ, by X-ray diffraction techniques while under pressure. The purpose was to determine the compression and compressibility of these materials as a function of pressure and to identify the products of any transformation that may occur due to the action of applied pressures.
The Present State of X-Ray Spectrometry
Authors: de Vries J. L. , Philips N. V.
Published: March 2019

If we want to evaluate the present state of X.R.S., we should do this in perspective with other methods, e.g. Optical Emission and Atomic Absorption Spectrometry.

One way to compare would be to estimate the number of papers published or given at conferences on these three methods. Table 1 gives a survey af some meetings. It is evident that X.R.S. is less talked about than the other methods. The rejuvenation of OES, thanks to the Plasma sources, can also clearly be seen.
Background and Sensitivity Considerations of X-Ray Fluorescence Analysis with a Room-Temperature Mercuric Iodide Spectrometer
Authors: Singh M. , Clark B.C. , Dabrowski A.J. , Iwanczyk J.S. , Leyden D.E. , Baird A.K.
Published: March 2019

Continued development of mercuric iodide (HgI2) detectors for x-ray spectroscopy at room-temperature has led to a considerable improvement in energy resolution and a better understanding of the various detector parameters which affect sensitivity. The basic properties of a mercuric iodide detector and some of its characteristics pertinent to x-ray fluorescence analysis have been previously reported (1,2,3). In this paper we present results of studies to determine the shape o£ peaks and continuum background. Also, the use of Hgl2 in characterizing water pollutants by XRF analysis has been investigated and compared to cryogenically cooled Si(Li) and room-temperature proportional counter systems.
Escape Peak Intensities in Argon/Methane Flow Detectors
Authors: Short M. A. , Tabock J.
Published: March 2019

X-ray proportional gas detectors are used in X-ray diffraction and X-ray fluorescence and emission analysis. The amplitude of the electrical pulses produced by these detectors is directly proportional to the energy of the incident X-rays. In most instances, the energy of the incident photons will be utilized completely in producing photo-ionization in the outermost shells of the detector atoms. If the energy of these photons is greater than the absorption edge of the atoms in the detector, a certain fraction of them will produce photo-ionization of an inner shell. This in turn results in the production of a characteristic X-ray. If this characteristic X-ray is absorbed by the detector, then the original X-ray may still be considered to have deposited the whole of its energy within the detector. In this case the amplitude of the detector output pulse will be the same as if the original X-ray photon had been absorbed entirely by photo-ionization of the outer shells. Because of the relatively low absorption of a detector for its own characteristic radiation, there is a significant probability that the detector characteristic X-ray will escape from the detector without producing further photo-ionization.
Empirical Approaches for the Treatment of Interelement Effects
Authors: Heinrich K. F. J.
Published: March 2019

Empirical algorithms for the treatment of interelement effects in x-ray fluorescence spectrometry are reviewed. It is recommended that the effects of tertiary x-ray emission be treated separately from those of x-ray absorption, and that standard reference materials of composition close to that of the specimen be used.
Rapid Photon-Excited Energy-Dispersive X-Ray Fluorescence Analysis for Solid and Liquid Mineralogical Samples
Authors: Ratyński W. , Parus J. , Tys J. , Ciszek A.
Published: March 2019

X-ray fluorescence spectroscopy is new becoming a tool in research and. industry. Semiconductor detectors are proving valuable in measuring fluorescent X rays, and so are providing a versatile tool for rapid multielement analysis of many types of samples. This paper will mainly be concerned with, different types of copper ore. An experimental setup has been designed to determine Cu, Fe and Pb of concentration ranging from 0.1 to 20, to 5, and to 4 percent, respectively, with analytical precision of 20% relative at 0.1% Cu, and 3% relative at 20% Cu. For excitation a 100 mCi Pu-238 source and/or a low power air-cooled X-ray tube were used. Data acquisition and “on-line” evaluation for each sample takes about 100 seconds. Electronics blocks and sub-systems used In the set-up are available commercially. The most important benefit to be obtained from the setup is the ability to provide precise, reproducible determinations of large numbers of samples day after day.
The Application of a Multichannel Fixed and Sequential Spectrometer System to the Analysis of Air Pollution Particulate Samples from Source Emissions and Ambient Air
Authors: Bennett Roy L. , Wagman Jack , Knapp Kenneth T.
Published: March 2019

The design and application of a newly-developed Siemens multichannel wavelength x-ray fluorescence spectrometer that has been specially adapted to the needs of the Environmental Protection Agency for rapid analysis of particulate samples is described. The system consists of sixteen fixed-wavelength spectrometers which are optimized for sixteen pre-selected elements and a computer-operated scanning channel which is used to determine additional elements that might be desired on a given sample. A minicomputer operates the instrument and custom-designed sample changer and processes the data.

Requirements for standards suitable for air pollution samples and the approaches used for the preparation of thin layer standards are discussed. Sensitivities, detection limits for elements of interest in air pollution, and the relative merits of aerosol filter types for x-ray fluorescence analysis have been determined. The system has been used to measure the elemental composition of a large number of samples from stationary source emissions, mobile sources, and ambient air.
Advance in NPL X-Ray Gratings and Spectrometers
Authors: Stedman M. , Franks A.
Published: March 2019

NPL x-ray gratings for use at grazing incidence in the wavelength range of 0.05 to 20 nm have diffraction efficiencies in the first order ranging from approximately 3% at 0.1 nm to 20% at wavelengths greater than 2 nm. X-ray gratings may have either a rectangular profile produced by processing a ruled or holographic grating or may have a shallow blazed waveform. In both types of grating, the grooves are formed in a vitreous silica blank and are usually overcoated with gold.

A precision short wavelength (0.05 to 0.5 nm) Rowland circle focusing spectrometer has bee n constructed, which can cater for concave gratings of radii between 5 and 15 m.
Absolute Calibration of Photoelectric Diodes
Authors: Day R. H. , Burns E. J. T.
Published: March 2019

Photoelectric diodes with aluminum photocathod.es have been calibrated in the energy range from 0.1 keV to 1 keV with a multielement Henke X-ray tube system using regenerative monochromatic filters. The calibration is performed at six energies: (1) Be - (0.109 keV) , (2) C - Kα(0.277 keV), (3) Ti –Lα1, 2(0.452 keV) , (4) Fe –Lα1, 2(0.705 keV), (5) Cu –Lα1, 2(0.930 keV), and (6) Al – Kαl, 2(1.487 keV). Several different 99.9%, (1000 series) aluminum foils were calibrated for use as cathodes. In addition, the average energy per electron ion pair, W, has been measured for methane at these same energies.
X-Ray Diffraction Analysis of the Calcium Carbonate Polymorphs
Authors: Silk S. T. , Lewin S. Z.
Published: March 2019

It is shown that the integrated intensities of diffraction lines from calcite and aragonite powders prepared by precipitation vary markedly, due to variations in sample packing efficiency arising from different degrees of polydispersity in the particle size distributions. Since prolonged grinding to equalize initially divergent distributions changes the polymorph composition, the packing effect imposes the principal limitation on the precision of the x-ray method for certain types of calcium carbonate preparations.
Electro-Optical Systems for Dynamic Display of X-ray Diffraction Images
Authors: Green Robert E.
Published: March 2019

Various electro-optical systems have been reported which permit intensification of X-ray diffraction patterns and thus a decrease in exposure time for recording and display of the X-ray images. Prior to 1966, all such electro-optical systems incorporated a large format X-ray image intensifier of the same type as conventionally used for medical and industrial fluoroscopy. In the past four years, a number of different systems have been reported which are superior to those developed prior to 1966. These systems may be grouped into two main categories, the large format variety for Laue diffraction applications, and the small format variety for topographic applications.

The purpose of the present paper is to describe the particular characteristics of both the large format and small format systems and to discuss the advantages and disadvantages associated with each type. Based on actual performance characteristics it will be shown that:

1.

A multiple stage image intensifier system coupled to an external fluorescent screen is the most sensitive and only truly instantaneous system; it can be used with very weak X-ray intensities, the resolution is currently limited by the external fluorescent screen to 42μ the system is extremely versatile in that it can be used both for large format recording of Laue patterns as well as for small format recording of X-ray topographe; the system has a very long lifetime since nothing is altered by X-radiation.

2.

An X-ray sensitive vidicon is the least sensitive; it must be used with extremely high intensity X-rays or long exposure times; the resolution is the highest at approximately 15μ and is limited by either bandwidth of the television system, the thickness of the X-ray sensitive target or the size of the electron beam at the target; due to the small size of the X-ray sensitive target the system can only be used for small format recording of X-ray topographs; the lifetime of the system is short since X-radiation causes degradation of the target.
X-ray Measurements of Surface Residual Stresses in Cold Rolled α-Brass
Authors: Wallace W. , Terada T.
Published: March 2019

Residual elastic stresses have been measured in cold rolled α-brass (30% zinc) using the available x-ray diffractometer methods. Residual stress values obtained by the two exposure and sin2ψ methods of stress analysis are compared with data obtained using Wagner's extrapolation method.

For deformations up to 50% reduction in thickness, tensile surface stresses prevailed, and in most cases could be detected by these methods. Uncertainty of the value of a0, the lattice parameter of the deformed' material, presents a serious limitation to the extrapolation technique. Using the approximation a0 = a0ann, residual stresses appear lower than, and frequently of opposite sign to those given by the two exposure method. In addition, lattice parameter variations in the near surface regions of the rolled sheet were opposite to those expected from the true macrostress distributions shown to exist by the two exposure method and by strain gauge techniques. The distributions of ahkl points in the extrapolation plots were in agreement with theory for a combination of anisotropic elastic stresses and low stacking fault density.
Characterization of PZT Thin Films Crystallographic Phases
Authors: Goehner Raymond P. , Eatough Michael O. , Tuttle Bruce A. , Headley Thomas J.
Published: March 2019

The use of grazing incidence parallel beam x-ray diffraction (GIXRD) in the characterization of lead zirconate titanate (PZT) films is described. This tool has enabled us to depth profile the films. The transmission electron microscopy (TEM) results obtained from a cross section of one film are shown to compliment the GIXRD results. The variation in crystallographic structure versus depth in the film was the primary focus of this study.

The insults from three PZT films having Zr/Ti ratios of 25/75, 48/52, and 75/25 are given. TEM results are reported from the sample with a Zr/Ti ratio of 48/52.
X-Ray Diffraction Studies on Laminated Magnetic Recording Media
Authors: Gorman Grace L. , Yogi Tadashi , Lambert Steven P. , Alvarez David P.
Published: March 2019

We have studied a series of laminated thin films by x-ray diffraction to correlate their structural and magnetic properties. Previous works have shown that the signal-to-noise characteristics of laminated magnetic films with non-magnetic interlayers can exceed that of single layer magnetic films. In the case where the magnetic layer is known to have low signal-to-noise performance, the signal has been observed to increase as the number of layers whereas the noise increases as the square root of the number of layers. This yields a net improvement of the signal-to-noise ratio, making the overall film more attractive as a magnetic recording medium. In this paper, we investigate films which are laminated layers of magnetic CoPtCr and non-magnetic Cr. The films were deposited with sputtering parameters that generally give low noise characteristics in single layer films. Up to four layers of CoPtCr films were made with Cr spacer layers of 2 nm. We observe some improvement in signal-to-noise characteristics and reduction in coercivity. X-ray diffraction analysis shows that the crystallographic c-axis, which corresponds to the magnetic easy axis, becomes more preferentially oriented perpendicular to the film plane with each additional layer. This change in preferred orientation is consistent with the reduced in-plane coercivity of the film. In the double CoPtCr layer with one Cr spacer layer experiment, we see that as the Cr spacer layer is increased from 0.5 to 8 nm, the c-axis of the CoPtCr again becomes more preferentially oriented out of the film plane, resulting in decreased in-plane coercivity. The media signal-to-noise improves once the Cr spacer layer is beyond 2 nm, consistent with previous observations.
Characterization of Lattice Defects and Concomitant Strain Distribution
Authors: Weissmann Sigmund
Published: March 2019

A number of X-ray methods characterizing lattice defects are described. They were developed in response to a variety of challenging problems in materials science, A method based on a computer-aided rocking curve analysis, CARCA, was developed which offers a rapid mapping of the dislocation structure in an epitaxial film, as well as a tensor analysis of nonuniform elastic strains. Characterization methods were developed in an attempt at bridging, systematically, the gap between micro and macromechanics when the problem arose to clarify the distribution of elastic strains emanating from stress concentrators such as notches, cracks, holes and to elucidate strain interactions. Gradients of elastic strains were characterized by a method of local intensity measurements. For crystal with homogeneous elastic strain distribution a tensor analysis is described, based on precision measurements obtained by the backreflection divergent beam method. A direct linkage between the imaging of the micro structure by TEM and the macro-response of deformation and recovery of commercial alloys was achieved by a version of the CARCA method, designed to characterize the lattice defects in polycrystalline materials. Example applications of the methods are presented with the hope that their usefulness may find adaptations in other areas of investigation.
Pole Figure and Orientation Distribution Function Analyses of FCC and BCC Metals
Authors: Feng Charles , Witt Fred
Published: March 2019

Texture, by definition, is a description of the spatial arrangement of the polycrystalline grains in solids. For metals, the grain distribution is commonly presented in a pole figure in which the pole density of a set of crystallographic planes is plotted using standard stereographic projection techniques. In this paper, the pole figure is plotted such that the center of the pole figure coincides with the plate normal. A vertical line drawn in the equatorial projection corresponds to the rolling direction, while a horizontal line corresponds to the transverse direction. Consequently, the spatial arrangement of the grains in a given sample may be determined from an analysis of the pole figure.
Experimental Considerations and Limitations in the Application of Ultra High Temperature (2100°C) X-Ray Diffraction
Authors: Iyengar Sampath S.
Published: March 2019

In-situ, high temperature X-ray diffraction (XRD) is an extremely useful tool for studying, monitoring or investigating crystal structure modifications as well as phase transformations in crystalline material during thermal treatments in controlled atmospheres. This technique has been used to investigate the thermal behavior of materials such as carbonate minerals, ceramic fibers, coating pigments, etc. The advantages of such a technique over the conventional practice, where samples are heat treated in a separate oven and then analyzed by XRD include: consistency of sample placement; preservation of high temperature structures to facilitate observation of metastable phases that are unstable upon exposure to outside atmosphere or during cooling; real time monitoring of reactions that occur, and products that are formed at a desired temperature or environment; and need for multiple samples or analysis.
Accurate Determination of Unit-Cell Parameters using Conventional X-Ray Powder Diffractometry
Authors: Toraya Hideo , Parrish William
Published: March 2019

A procedure for the accurate determination of unit-cell parameters using conventional Xray powder diffractometry is described. Two important factors in the procedure are: 1) the use of high-resolution-type diffractometer, which can suppress the axial beam divergence and thus gives nearly symmetric diffraction profiles in the low 2θ region and 2) the use of a new algorithm for systematic peak shift correction during the least-squares determination of unit-cell parameters of a sample with an internal standard [Toraya & Kitamura (1990). J. Appl. Cryst. 23 , 282-285]. The procedure has been tested by measuring successively the unit-cell parameter of W, CeO2, and Si in three mixtures, Si+W, W+CeO2, and CeO2+Si: the unit-cell parameter of W, which was first determined by using NIST SRM 640b Si powder as an internal standard reference material, was used as a standard reference value to determine the unit-cell parameter of CeO; in the next W+CeO2 mixture, and so on. The difference between the end value of observed Si unit-cell parameters and the starting value of 5.430940(35) Å were just 1 to 5 p.p.m. High accuracy is attainable in measuring the uni-cell parameters even with the conventional powder diffractometry provided with the nearly symmetric diffraction profile and the algorithm for peak shift correction used in the present study.
The Study of Fatigue Behavior of Ductile Cast Iron by Means of X-Ray Fractographic Technique
Authors: Yajima Zenjiro , Shinohara Masaki , Ishikawa Ken-ichi , Hirose Yukio , Tanaka Keisuke
Published: March 2019

X-ray diffraction observation of metal fractures provides fracture analysis with useful information on the mechanisms and mechanical conditions of fracturing. This method is called “X-ray fractography” and has been developed especially in Japan as a new engineering tool for fracture analysis.
HFIT, A Program for Interactive Analysis of Powder Diffraction Data
Authors: Will G. , Höffner Ch.
Published: March 2019

HFIT is a program for the analysis of diffraction diagrams containing overlapping peak clusters. Profile functions have been implemented to analyze synchrotron diffraction data. It is written un Turbo C++ for PC operations. The analysis is done by operator interaction. The analysis is done on sections of the diffractogram containing a maximum of 2048 data points or 100 diffraction maxima. Special care is taken for smoothing the data and for the subtraction of background.
Determination of Dislocation Densities in Hexagonal Close-Packed Metals using X-Ray Diffraction and Transmission Electron Microscopy
Authors: Griffiths M. , Winegar J.E. , Mecke J.F. , Holt R.A.
Published: March 2019

X-ray diffraction (XRD) line-broadening analysis has been used to determine dislocation densities in zirconium alloys with hexagonal closepacked (hep) crystal structures and a complex distribution of dislocations reflecting the plastic, anisotropy of the material. The validity of the technique has been assessed by comparison with direct measurements of dislocation densities in deformed polycrystalline and neutron-irradiated single crystal material using transmission electron microscopy (TEM). The results show that-there is good agreement between the XRD and TEM for measurements on the deformed material whereas there is a large discrepancy for measurements on the irradiated single crystal; the XRD measurements significantly underestimating the TEM observations.
Toroidal Monochromators in Hybrid XRF System Improve Effectiveness of EDXRF Tenfold
Authors: Furnas Thomas C. , Kuntz Gordon S. , Furnas Richard E.
Published: March 2019

Our objectives in Instrument design & development are to improve the QUALITY OF THE DATA which can be obtained and presented to a computer system for analysis and to explore the corresponding choices which such improved data quality allows.

In usual EDXRF systems, the detector views the entire scattered and fluorescence radiation from a sample illuminated either by a direct beam or by a secondary target. In either case, the beam may be filtered before it strikes the specimen. Most efforts to mono-chromatize the exciting radiation or to reduce the background under the fluorescent peaks from the sample result in (a) decreases in X-ray flux available for excitation, (b) significant increases in power expended in the X-ray tube, or (c) extremely close coupling of the system components. These are NOT THE ONLY CHOICES AVAILABLE.
X-Ray Fluorescence of Intermediate- to High-Atomic-Number Elements Using Polarized X Rays
Authors: Strittmatter R. B.
Published: March 2019

The use of polarized x rays as the excitation source for x-ray fluorescence (XRF) measurements has been shown to significantly improve signal-to-background ratios. However, previous studies on polarized x rays applied to XRF techniques have concentrated on low-energy fluoresced x rays (<30 keV). In many cases strong matrix effects exist or the analyte is encased by a material that strongly attenuates low-energy x rays. These situations may preclude accurate assays based on L x-ray detection, and techniques based on the detection of higher energy K x rays may be more suitable because of the increased penetrability of higher energy x rays. The measurements and calculations reported in this work were made to assess the improvement in signal-to-background ratios and the increase in accuracy and detection sensitivity achievable by using polarized x rays as the excitation source for fluoresced x rays having energies between 25 and 110 keV.
"Standard-Background" Method of X-Ray Spectral Analysis for Quality Control of Noble Metals in Alumina-Based Automobile Exhaust Catalysts
Authors: Gurvich Yury M.
Published: March 2019

Development of matrix correction procedures in the field of X-ray spectral analysis leads usually to “universal” algorithms which allow use of a common calibration equation for assay of various materials with different composition and concentration ranges. In many applications, such methods can guarantee accuracy of 3-5% rel.

For X-ray analysis of automotive catalysts, one such technique is based on the theoretical correction of interelement effects. The article states that “the overall accuracy of this approach is about 10% relative error, although this may vary depending upon the particular specimen being analyzed.” However, narrow specification limits for the quality control of catalysts require the total error of analysis less than 1-1.5% rel.
The Analysis of Oil Additives Using Fundamental Influence Coefficients
Authors: West H. M.
Published: March 2019

One of the most important applications o£ XRF in the oil industry has been in the analysis of oil additives which range from Mg to Ba. In such a low atomic number, hydrocarbon matrix, small variations in the additives cause pronounced changes in the average atomic number of the matrix and hence give rise to strong interelement effects. In recent years a number of mathematical methods have been developed to correct the measured X-ray intensity of the analyte litie for these considerable effects. This paper describes a method for the determination of Zn,Ba,Ca,CI,S,P and Mg in oil additives using a concentration based correction model in which influence coefficients (alphas) are applied.
A New Computer Algorithm for Qualitative X-Ray Powder Diffraction Analysis
Authors: Huang T. C. , Parrish W.
Published: March 2019

An effective and practical computer algorithm has been developed for rapid and precise phase identification of polycrystalline materials by X-ray diffraction methods using the JCPDS database and/or user created standard files. The entire JCPDS file was reorganized for efficient search. Identifications are facilitated by a number of options: automatic correction of systematic errors using internal standard reflections, selectable window widths for file searching, elemental restrictions (chemical prescreening), handling preferred orientation, match without using intensities, match with 3 reflections, and others. A comprehensive algorithm for calculating a figure-of-merit (FOM) is used so that the “correct” phases can easily be identified with highest FOMs. This method has been tested extensively on a wide variety of analyses and is applicable to either a host or a minicomputer.
INDEX, A Program to Reconcile Powder Diffractograms
Authors: Horn Tommy , Jenkins Ron , Ladell Joshua
Published: March 2019

This paper describes an interactive computer program, INDEX, which was written at Philips Laboratories as part of the software development effort for the APD 3600: Automated Powder Diffractometer. This program reconciles the differences between calculated and observed powder diffractogram “d-spacings” by unit cell parameters refinement and/or correction of observed lines for “significant“ systematic errors. The reconciliation procedures, described below, yield a set of residual differences which may be due to x-ray photon statistics, random gear imperfections, or minor instrumental aberrations. Lattice parameters accuracies of 4-5 parts per 104 can b e obtained routinely on powder diffractometers when systematic effects have been taken into account. The interactive nature of INDEX permits intervention at critical stages where it is most beneficial with a minimal number of keystrokes.
Comparison of Residual Stress Measurement and Breaking Strength on Alumina Rods
Authors: Snoha D. J. , Ruud C. O. , Cassel H. D.
Published: March 2019

X-ray diffraction (XRD) utilizing copper K-alpha radiation and the single exposure technique (SET) was used for residual stress measurement on two different thermal treatments of Al-300 alumina rods. The measurements were performed in the axial and tangential directions on forty halves of twenty broken rods. The twenty rods were intially annealed for 8 hours at 1000°C; then ten were slow cooled and ten were equilibrated at 1450°C then force-air quenched. A fine mesh sapphire (alumina) powder was used as a zero stress standard for the determination of calibration validity of the position sensitive scintillation detector based (PSSD) stress measuring instrument used for this study. This instrument was developed at the Materials Research Laboratory of The Pennsylvania State University.