bluuebunny/crossref_metadata_2025_split huggingface dataset:
Micro Fluorescent X-Ray Analyzer
Authors: Shiraiwa Toshio , Fujino Nobukatsu 
Published: March 2019

AbstractA micro fluorescent X-ray analyzer with a focusing type of spectrometer has been developed to analyze samples of small amounts such as extracted inclusions or precipitates from metals or small areas in samples from 0.1 to 2.0 mm in diameter. This instrument is expected especially to analyze powder samples of small quantity because average values from such samples can be obtained and because surface conditions of the samples scarcely affect the results compared with their effect in electron probs microanalysis. A commercial X-ray tube is combined with a device of slits limiting incident X-rays, a focusing spectrometer with a Rowland circle of 4-in. radius, and a microscope of low magnification for observing the analyzing point on the samples. The wavelength range of the spectrometer with LiF and ADP analyzing crystals is from 1.20 to 9.94 Å, and, therefore, higher elements than aluminum in atomic number can be analyzed. The authors exerted their efforts to obtain the higher X-ray intensities in order to analyze smaller areas. The X-ray intensities obtained are satisfactory, except for light elements. For example, the detected X-ray intensity of pure nickel is 1650 cps with the use of a 0.1-mm diameter specimen, and that of pure sulfur is 52 cps with the use of a 0.1-ramdiameter specimen; however, with a 1-mm-diameter specimen, the intensity of pure nickel is over 5000 cps and that of pure sulfur is 1650 cps. These correspond to the intensities from 20-mm-diameter specimens of those elements when a flat-crystal spectrometer is used. The calibration curve for quantitative analysis generally varies with the sample area under analysis, but the same curves are obtained if the sample area is larger than 1 mm in diameter. Then, powder samples are analyzed quantitatively by using a plastic sample holder of 1-mm diameter and 0.3-mm depth. This instrument has good ability for microanalyzing trace elements by, for example, the ion-exchenge membrane method. The sensitivity represented is nearly 5000 cps/μg for Ni Kα from NiSO4that is soaked and dried in thin rice paper. Some applications of the micro fluorescent X-ray analyzer to precipitates in steels and corrosion products are reported.
The Effect of Surface Roughness in Polymers on X-Ray Fluorescence Intensity Measurements
Authors: Gianelos J. , Wilkes C. E. 
Published: March 2019

AbstractWe sought to determine how seriously surface roughness affects X-ray intensity measurements in polymers. Fourteen elements ranging from lead to silicon were added singly to fourteen batches of trans-1,4-polyisoprene. Smooth pressings of each batch were made, and intensity readings were taken (I0). Reproducibly rough surfaces were made from these by molding a square wire-mesh pattern into them, with the use of Tyler standard sieve screens. The amount of roughness was controlled by using screens of very fine to very coarse mesh. We studied the change in the X-ray intensity of the rough surfaces versus the smooth [(I/I0) × 100] with respect to: (1) the degree of roughness, (2) concentration of the added element, (3) emitted wavelength of the added element, (4) X-ray tube target material, and (5) correction for matrix effects on the intensity. We found that, at wavelengths emitted below 1 Å, intensity differences are small, regardless of which factors were varied. At wavelengths emitted above 1 Å, however, we found large differences. The intensity changes are highly dependent on roughness. Also, they become greater at the longer emitted wavelengths and with increasing concentration of added elements. Beginning with Ti Kα, losses are much higher with the use of chromium primary radiation than with tungsten. A technique of milling polyethylene into polymers with rough surfaces to provide a smooth surface is discussed.
A Study of X-Ray Fluorescence Method with Vacuum and Air-Path Spectrographs for the Determination of Film Thicknesses of II-VI Compounds
Authors: Chan Frank L. 
Published: March 2019

AbstractFilms of II-VI compounds have been prepared by vacuum technique for the determination of their thicknesses. Some difficulties have been experienced in preparing good quality films- The positron of the substrate in the vacuum chamber, the rate of deposition, and the temperature of sublimation are some of the factors influencing the quality of these films. For instance, films of cadmium sulfide could be prepared in the usual yellow or orange color or in colors ranging from brown to black, depending on the conditions enumerated. For energy conversion, a film of proper thickness is one of the requirements for aerospace application. Among the various methods used for the determination of the thickness of these films, X-ray fluorescence can be performed rapidly and nondestructively. After determination of thickness by the X-ray fluorescence method, the samples can be used for other determinations and for energy conversion without their efficiency's having been affected. Other physical and chemical methods have been worked out. Comparison of these methods with the X-ray fluorescence method is made. Procedures and results are presented.
The X-Ray Wavelength Scale in the Long-Wavelength Region
Authors: Burr A. F. 
Published: March 2019

AbstractRecently the X-ray wavelength scale has been put on a consistent basis by the selection of the W Kα1, line to be the wavelength standard foe the whole X-ray region of the electromagnetic spectrum. To help establish this scale, four other X-ray lines, which had been measured with a precision approaching 1 ppm, were selected as secondary standards. However, since the longest of these lines is the Cr Kα2 line at 2.293606 Å, other lines whose wavelengths are less precisely known have been used for calibration purposes. The most interesting of these is the Al Kα. line, which plays an important part in the effort to connect the X-ray wavelength scale to the basic standard of length. Two other often-used lines are the Cu La line at 13.339 Å and the O Kα line at 23.62 Å. It is, however, necessary to take several steps to trace the accepted values of these lines back to the basic X-ray wavelength standard. Furthermore, the uncertainties introduced by the effects of the chemical combination and the large natural line widths limit the precision obtainable. It has been suggested that the first resonance line of the Ne K edge in the 14-Å region would overcome both of these difficulties. It has also been suggested that the highfrequency limit of the bremsstrahlung radiation would make a particularly convenient reference mark. This method is discussed here, and it is shown that the accuracy obtainable by this method is better than that obtainable by means of some commonly used reference lines.
The Application of Radioisotope Nondispersive X-Ray Spectrometry to the Analysis of Molybdenum
Authors: Langheinrich A. P. , Forster J. W. 
Published: March 2019

AbstractRadioisotope excitation, solid-state detection, and multichannel pulse-height analysis have been applied successfully to the determination of molybdenum in copper and molybdenum-process intermediates. Analytical data are presented, and comparisons are made with the conventional X-ray fluorescence approach. The equipment performed satisfactorily in molybdenum plant control and shows promise for other industrial applications with the development of suitable isotope sources.
Multistep Intensity Indication in Scanning Microanalysis
Authors: Tomura Teruichi , Okano Hiroshi , Hara Koichi , Watanabe Tadao 
Published: March 2019

AbstractImprovements on the semiquantitative analysis in a scanning electron-probe microanalysis will be discussed. Improvements have been attained by the development of a new content mapping attachment. By using this attachment, the X-ray intensity is indicated on a cathode-ray tube in nine steps of brightness. A discrimination operation on the intensity information can be done to help the observation of fine concentration variation in the specimen. The scanning image about an element in the specimen is displayed on the screen of the cathode-ray tube or on a paper tape by a typeout recording. The image is composed of 2500 picture elements. The brightness of each picture clement corresponds to an exponentially modulated X-ray intensity emitted from the corresponding point of the specimen surface. The correct information about the X-ray intensity to the observer is given by using this kind of modulation. In the image display on typewritten paper, the X-ray intensity is indicated with numbets from 0 to 9 according to the intensity grade. Each number is printed with an individual color to present a contour map of the element distribution. The time necessary to obtain one complete contour map is about 8.5 min.
X-Ray Double-Crystal Method of Analyzing Microstrains with BeO Single Crystals
Authors: Chikawa Jun-ichi , Austerman Stanley B. 
Published: March 2019

AbstractA double.crystal arrangement was employed in the symmetrical Laue arrangement [(+n, −n) setting]. A perfect BeO crystal was used for the first crystal of the double-crystal spectrometer. To obtain a high X-ray intensity, the thickness of the crystal was made to correspond to a maximum of Pendellosung interference. A slit was pieced between the first and second (specimen) crystals to select the X-rays which precisely satisfy the Bragg condition. The slit was adjusted to avoid significant Fraunhofer diffraction. In this method, the incident beam for the specimen crystal was parallel enough to obtain intrinsic rocking curves of the specimen crystal. As an application, the method was used for determination of the senses of slight strains in BeO crystals.
An X-Ray Diffraction Study of the Aging Reaction in Two Austenitic Alloys
Authors: Abraham J. K. , Wilson T. L. 
Published: March 2019

AbstractAging processes exhibiting cluster to precipitate transitions were studied in polycrystalline line austenitic iron-base alloys with a Siemens' Guinier camera. This camera combines the Seemann-Bohlin focusing geometry with a curved-crystal monochromator arid thus maximizes the resolution of observed sidebands and the weak precipitate lines. Growth studies encompassing a cluster-size range of 15 to 70 unit cells were followed. For the systems of interest, this coincided with a variation from detectable hardness increase to a stage of maximum hardness immediately preceding precipitation, Cluster sizes were calculated on the basis of the Guinier model; variation with time and temperature permitted calculations of an apparent activation energy in the one system where decomposition was spontaneous. An iron-nickeltitanium alloy was used to study aging in a ternary system. Behavior was classic in that the cluster size present on quenching grew with aging coincident with a simultaneous hardness increase. Calculation of activation energies indicated strongly that transportation of nickel to, or iron from, the cluster was rate determining. Upon overaging, the nickel-titanium enriched clusters gave way to the hexagonal Ni2Ti phase. An iron-nickel-chromium-niobium quaternary, in addition to presenting a clustering system similar to the above ternary, showed two rather interesting phenomena. First, chromium was necessary for precipitation; the ternary ironnickel-niobium did not age. Secondly, a stable Pe2Nb Laves phase present upon quenching from 2200°F disappeared on aging in favor of nickel-niobium clusters; an incubation time for the formation of these clusters existed, and its duration was about 4 hr. An asymmetry was noted in the diffraction intensities about the (311)γ line in both systems. In the iron-nickel-titanium case, the asymmetry was only in intensity, whereas, with the iron-nickel-chromium-niobium alloys, the asymmetry existed in both intensity and position. Interpretation of these observations is made on the basis of anticipated variations in scattering factors, lattice spacings, and cluster sizes.
Provision, Suitability and Stability of Standards for Quantitative Powder Diffractometry
Authors: Jenkins Ron 
Published: March 2019

Standards required for quantitative powder diffractometry are essentially of three types as shown in Table 1 - external instrument standards for the initial and long term check of instrument alignment (i.e., an “instrument” standard), external analytical standards, which are similar in composition to the specimens to be analysed, for the preparation of calibration curves for “in-type“ analysis; and internal analytical standards for the minimization of problems due to variations in specimen absorption.The ideal equipment alignment standard should be free from preferred orientation, stable and available in large quantities, since it should serve the dual role of providing a continuing indication of the performance of a given diffractometer, as well as allowing absolute intensity comparisons to be made between different diffractometers.
Quantitative Analysis of Clay Minerals in Drilling Mud Solids
Authors: Feuerbacher D. G. , Clark R. R. 
Published: March 2019

AbstractQuantitative analysis of six clay minerals commonly found in drilling mud solids is studied by x-ray diffraction using the method of internal standards. Standard clay samples are used with three internal standards to derive calibration curves from which four synthetic mud solids are analyzed. If careful sample preparation and handling are employed, reasonably accurate and reproducible results are obtained.
Quantitative X-Ray Diffraction Phase Analysis of the Oxidation of Steel by a Direct Comparison Method
Authors: Biederman R. R. , Bourgault R. F. , Smith R. W. 
Published: March 2019

AbstractA direct comparison x-ray method using crystal structure Information has been developed for rapid quantitative analysis of the oxide phases present in oxidized steels. This procedure is similar to that used for the analysis of retained austenite in hardened steels and requires no external or internal standards for accurate oxide determinations. Successful application of this technique has been achieved for a variety of steel oxide mixtures and excellent correlation with microstructural analysis results has been found. Accurate determinations have been made of the volume fractions of Wustite (FeO), Magnetite (Fe3O4) and Hematite (Fe2O3) for a wide range in steel carbon content and transformation treatments. Many oxide mixtures that differ over a wide range in the amounts of each of the three oxides phases have been measured successfully. The procedure is simple, the method direct and the analysis accurate.
X-Ray Fluorescence Analysis of Portland Cement Through the Use of Experimentally Determined Correction Factors
Authors: Anderson C. H. , Mander J. E. , Leitner J. W. 
Published: March 2019

AbstractCorrection factors, termed α-factors, similar to those defined by LaChance and Traill have been generated by the addition of variable, known amounts of individual oxides, or other compounds, to a base cement sample and measuring the x-ray intensities of the elements of interest. The effects of all common constituents of cement on the determination of CaO, SiO2 and Al2O3 were found. Factors for rhodium and chromium primary radiation were determined and, in general, showed small but significant differences. The factors for rhodium at 50kV and 30kV were substantia11y identical. The correction factors were tested through the use of the NBS 1011- 1016 cements as reference standards to analyze the new proposed NBS cement series. The correction factors not only furnished improved calibration curves, but also allowed the determination of CaO, Al2O3 and SiO2 with an average deviation of less than 0.2% (absolute) from the provisional values furnished with the standard samples.
A Versatile X-Ray Fluorescence Method for the Analysis of Sulfur in Geologic Materials
Authors: Elsheimer H. N. , Fabbi B. F. 
Published: March 2019

AbstractNonproportionality of X-ray fluorescence intensity vs. concentration of sulfur occurs in geologic materials prepared as ground samples. Samples containing sulfur as sulfate yield higher intensities than an equivalent amount of sulfur as the Sulfide. Although the intensity of free sulfur decreases markedly during a short exposure to X-rays in a vacuum, and sulfide intensities decrease over a much longer time period, sulfate intensities show no deterioration with time.A fusion procedure utilizing a LiBO2-Ce(NH4)2(NO3)5 flux has been developed for geologic materials to oxidize all sulfur in a multiplicity of oxidation states to a single oxidation state, namely, the sulfate. The procedure is applicable over a wide range of concentrations (0.5 - 28 wt. % total sulfur) with a detection limit of 0.01%. A suite of chemically analyzed rocks containing both sulfides and Sulfates is used for standardization.
Quantitative Nondispersive X-Ray Fluorescence Analysis of Highly Radioactive Samples for Uranium and Plutonium Concentration *
Authors: Pickles W. L. , Cate J. L. 
Published: March 2019

AbstractFluorescent x-ray energy spectra were successfully acquired from uranium and plutonium in 400:1 ratios in samples containing 2 Ci/gram of mixed fission products. The analytical system consists of a silver transmission anode x-ray tube, a low-Z scattering chamber, a magnetic ß-ray trap, a beam monitor probe, a commercial Si(Li) detector, a set of modified electronics to handle the large γ-ray overload rate, and a Computer analyzer using a higher-level language to handle data reduction.The Computer programs used to obtain peak areas from the closely spaced uranium and plutonium (Lα 1+2) peaks were constructed to make use of knowledge of upper-edge tailing gained in this experiment. Programs are being developed to properly remove background under the uranium and plutonium peaks. Absorption effects in the larger samples have been measured using the ratio of uranium (Lℓ) to uranium (Lα) peak area and are incorporated in the data-analysis schemes. A titanium monitor probe, consisting of a fixed titanium plate near the sample, introduces a constant-area titanium K x-ray line into the spectrum. The program uses the area of this peak to correct for effects of total exciting flux, geometry, and system dead-time losses. Standard samples of various types are used to generate calibration curves from which quantitative results are obtained.Samples are taken from dissolved high-burnup power-reactor fuel rods. The liquid sample is acidic and has a radiation level at one foot of approximately 2 R/hr ß and 300 mR/hr γ. Sample preparation involves only the evaporation of the liquid sample on a 1/2-mil polycarbonate substrate and subsequent sealing with another layer of polycarbonate film. The samples are then mounted in standard 35-mm slide-holders.Preliminary testing on a limited number of prepared uranium and plutonium samples indicates a precision of about 1% and an accuracy of about 2%, over a range of 1 to 58 μg total mass. The samples have not yet been verified by independent chemical analysis. The system has been installed at the AEC Savannah River facility for extensive testing.
X-Ray Diffraction Residual Stress Analysis Using High Precision Centroid Shift Measurement Techniques - Application to Uranium-0.75 Weight Percent Titanium Alloy
Authors: Baucum W. E. , Ammons A. M. 
Published: March 2019

AbstractThe standard three-point parabola technique has been used extensively in residual stress analysis for peak location with precisions (standard deviation) of peak shift measurements in the range of 0.01° to 0.03° (20). While this level of precision produces useful data for peaks at high diffraction angles, it becomes untenable when a material with high elastic modulus is encountered whose only suitable peak falls below approximately 140° 20. Uranium-0.75 weight percent titanium alloy, which is the material of interest in this investigation, falls into this category.A technique has been developed by which diffraction peak centroid shifts are determined with a precision of 0.002° of diffraction angle (Δ20). The method consists of step-scanning over the peak of interest to acquire data in digital form. A small Computer is then used to locate the diffraction line by calculating its centroid from digital data.The use of a special probe consisting of four distance transdueers (LVDT) to achieve precise alignment of the specimen surface on a Siemens back-reflection stress diffractometer will also be described.A calibration experiment was performed on uranium-0.75 titanium tensile specimens in which the X-ray diffraction response was measured as a function of various levels of applied stress in order to determine the experimental elastic moduli. It was found that repetitive analyses on a single area of a cylinder had a standard deviation on the measured diffraction centroid shift of 0.002 degree which is approximately an order of magnitude smaller than that achieved by the standard parabola fitting technique. Thus, the residual stress can be defined to a precision of ∼ 2,000 psi, as opposed to 30,000 psi, at best, were the measurements obtained by the conventional procedure.
Calculation and Measurement of Integral Reflection Coefficient Versus Wavelength of “Real” Crystals on an Absolute Basis
Authors: Brown D. B. , Fatemi M. , Birks L. S. 
Published: March 2019

AbstractA method for calculation of the integral reflection coefficient of crystals of interrnediate perfection is introduced. This method can greatly reduce experimental effort for the selection and calibration of crystals, It also serves as a conceptual framework for studies of mosaic block structure and of crystal modification. Good agreement between calculated and experimental values of the integral reflection coefficient is shown for, (a) LiF crystals of two degrees of perfection, (b) elastically bent quartz, and (c) 001, 005, 006, and 007 diffraction from KAP. Zachariasen's division of crystals into two types is extended. It is concluded that the integral reflection coefficients for 200 LiF cannot be raised to the ideally imperfect limiting values.
X-Ray Production Cross Sections for Ti, Co, Ge, Rb and Sn by 16 - 44 Mev Oxygen Ion Bombardment
Authors: Chaturvedi R. F. , Duggan J. L. , Gray T. J. , Sachtleben C. C. , Lin J. 
Published: March 2019

AbstractAbsolute K-shell ionization cross sections were measured for Ti, Co, Ge, Rb, and Sn for incident oxygen ions from 16-44 MeV. The x-rays were measured with a high resolution Si(Li) detector (166 eV at 5.9 keV). All of the data represents cross section measurements for thin targets. The measured cross sections for these elements are compared to the theoretical predictions of the Binary Encounter Approximation (BEA). Kα/Kβratios and energy shifts were also extracted from the data. The experimental data are compared to measured cross sections for other elements to give an overview of the systematics for oxygen ion induced x-ray production cross sections in this energy range. Some comment will also be given in regard to the use of oxygen ions to measure the parameters associated with ion implanted semiconductors.