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.

A system, has been designed and tested for rapid energy dispersive diffractometry and simultaneous fluorescence analysis. A turntable composed of the sample chamber with attached air-cooled x-ray tube allows the 2θ angle to be varied with respect to the stationary Si(Li) detector. Data for most analyses can be obtained in one minute per sample. Results are stored in the memory of a multichannel analyzer and are read out on a CRT, strip chart recorder or tabulated in digital format by a computer.

In any petroleum product, a high sulphur content is considered undesirable. Sulphur in diesel fuels is claimed to aggravate problems of wear and deposit. With residual oils used in some metallurgical operations, the sulphur combustion products can have an adverse effect on the metal. In combustion equipment, the oxides of sulphur together with water vapour can lead to undesirable acid condensatlon on cool metal surfaces.

The more general problem is air pollution. Local and national legislation present the oil industry with a continuing demand for fuels of lower and lower sulphur content. Best use must therefore be made of crude oils of inherently low sulphur content. Desulphurising processes are comnonly used for distillates and are available for residual products. Such processes however tend to add significantly to produetion costs.

Moderate counting rates, in excess of 400 cps at a signal/noise ratio of 18 on 3.5% NaaO in rocks, permit high-precision quantitative analysis for light elements in silicates. Special advantages of fluorescence analysis in the 10 A region, with adequate excitation provided by an aluminum target tube, will be described. These advantages include an ease of discrimination by excitation potential and by high dispersion using large 2d space crystals. Minor and simple modifications of the optic path combined with electronic discrimination make the method ideal for sodium and magnesium. Routine runs over periods of days have been made possible by a new technique of calibration involving computer corrections for systematic drift from any source. Repeated tests show that the total analytical error, including specimen preparation, closely approaches that of the counting statistics used, and that the drift corrections are complete. In granitic rod; analyses resulting precisions (standard deviation/mean) are 1% for 2-5% Na2O and 2% for 0.25-1.0% MgO.

Errors pertinent in dual beam absorptiometry have been studied. Five areas are given in detail: 1. Scattering, in which a computer analysis of multiple scattering shows little error. 2. Geometrical configuration effects, in which the shape of the sample influences accuracy. 3. Poisson variations, in which dosage and statistical error are minimized. 4. Absorption coefficients, in which variations in compilations are examined. 5. Filtering, wherein is shown the need for Kβ filtering. A zero filter system is outlined.

The intensities of x-rays scattered by amorphous Fe80P13C7 and Fe40Ni40P14B6 samples have been measured as a function of photon energies E at fixed scattering angles 2θi using a Li-drifted Si detector and polychromatic x-rays generated by a 50KV full-wave rectified generator. The coherently scattered intensity per atom was calculated for free-standing samples as well as samples contained in a Be or pyrolytic graphite cell, after the evaluation of the energy dependence of the primary beam spectrum by an iterative process. The interference functions were then calculated from the data obtained in transmission and reflection, and compared with those measured with the conventional variable 2θ technique. Good agreement between energy-dispersive diffraction (also called variable wavelength technique) and variable 2θ diffraction was observed in all cases.

Ion implantation is known to increase the lifetime of cutting tools. Current theories are the increase in lifetime is caused by an increase in the residual stress, or by work hardening of the surface associated with the implantation. In this work the effect of ion implantation on the residual stress in titanium nitride coatings made by the standard industrial methods of chemical and physical vapor deposition (CVD and PVD) is studied. It is found in the as-received condition (unimplanted), the residual stress levels are near zero for CVD materials and highly compressive, of the order of 6 GPa, for PVD materials. Ion implantation has no effect on the residual stress: in the coatings made by CVD. Nitrogen does increase the compressive residual stress by some 10% in the near surface regions of PVD coatings, while nickel-titanium dual metal ion implantation does not have any effect. It appears that the lifetime increase is not associated with residual stress effects.

Deformation in polycrystalline materials is highly inhomogeneous on a micro scale. This inhomogeneity arises from the anisotropy of the constituent grains, coupled with local configurational parameters such as texture, gram size or proximity to a free surface. In a recent paper, we had outlined a new method that extended the traditional x-ray stress analysis to yield quantitative measures of such inhomogeneous deformation. In this paper, this method is used to study the partitioning of inhomogeneous deformation between the phases of 60-40 brass tensile specimens subjected to applied loads.

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.

The X-ray fractographic technique was applied to fatigue fracture surfaces of tempered AISI 4340 steel. Residual stresses and half-value breadths were measured by the X-ray diffraction.

In the present paper, the residual stresses and plastic strains on fatigue fracture surfaces and some parameters in the fracture mechanics were investigated. A simple model of mechanics was proposed to explain these experimental results.

The salts of hydrazine or methyl derivatives of hydrazine were prepared by neutralization of the base with inorganic acids, for instance, HBF4, HClO4, H SO4, and HCl. Upon recrystallization of the product from a suitable solvent, X-ray diffraction patterns were obtained. Hydrazine tetrafluoborate H2N-NH2·HBF4 was found to crystallize in the monoclinic system. Cell dimensions and possible space groups were determined. The corresponding perchlorate salt crystallizes in two forms, one of which is isomorphous with hydrazine tetrafluoborate. The second form seems to be stabilized by small amounts of water.

The tetrafluoborate salt was prepared from the 1,1-dimethyl hydrazine. It was found to crystallize in the tetragonal system with a primitive unit cell. The perchlorate salt of this base is isomorphous with the fluoborate but with a slightly larger unit cell. Both materials undergo plastic-like deformation. The general appearance and mechanical properties are similar to those of a hydrocarbon wax. The 1,1-dimethyl hydrazine sulfate and the 1,1-dimethyl hydrazine hydrochloride have a lower symmetry than the HBF4 salt and do not show the wax-like properties of the latter. Based on the study of these chemically related compounds an explanation is offered for the properties of 1,1-dimethyl hydrazine tetrafluoborate in terms of crystalline structure.

X-ray emission spectra have been obtained with a single crystal spectrometer having a resolution λ/dλ of 6,640 for iron Kβ5 spectra. The spectrometer consisted of a Jarrel-Ash Microfocus unit in conjunction with a Picker diffractometer which was operated as a rocking crystal spectrometer with a stepping angle of 1/400th of a degree. Kβ5 and Kβ1,3 spectra have been obtained from iron, Fe0.9Mn0.9Ge, Fe1.60Ge, FeGe, FeGe2 and germanium. Because the K05 spectra are due to 4p - Is transitions from the 3d bands, the Kβ5 intensities are a direct measure of the overlap or hybridization of the 3d - 4s - 4p bands. The experimental results can be correlated either with orbitals derived on the basis of coordination, or more roughly with possible band distributions.

For phase analysis of small amounts of material in an x-ray powder diffractometer the sample is often spread on a sample mounting plate or support plate. Different types of plates on which thin samples can be mounted are:

• - silver membrane filters

• - metal or other polycrystalline plates

• - polymer membrane filters, for example PVC, polycarbonate, cellulose nitrate

• - glass slides

• - single crystals; cut so that no diffraction lines occur.

Filters are often used to collect environmental dust; these samples can be analysed “as received,” Glass slides are inexpensive, flat, and readily available. Polycrystalline filters and plates have the disadvantage of possible line overlap with lines of the sample material (refer to figure 1), Glass plates or polymer filters have the high and curved background due to amorphous scatter as shown in figure 2.

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

The 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.

A technique is described for the study of the early stages of precipitation hardening in single-crystalline and poly crystalline copperberyllium alloys. Since no trace of the equilibrium precipitate responsible for hardening can be detected by ordinary X-ray or metallographic techniques prior to the onset of overaging, the described method is based on the changes produced in the matrix as the result of the formation of aggregates along preferred lattice planes. Such formations produce accommodation strains in the matrix lattice which, can be detected as a change in the intensity and angular range of matrix reflection.

An interpretation of the age hardening sequence in a copper - beryllium, alloy after isothermal annealing is presented in terms of fundamental transformations.

The two general uses of proportional counters in X-ray analysis are discussed in the light of advantages and limitations inherent in the type of counter construction. Some effects on spectrographic results and industrial gaging are cited.

Stresses in polymeric materials can be measured by diffracting X-rays from embedded crystallites that yield suitable powder diffraction lines. An appropriate technique for this has been, reported by C. S. Barrett and Paul Predecki elsewhere and is reviewed here with additional details. It is based on a diffractometer modified so as to operate at very high 26 angles, with specimens prepared in various ways. Results show that adequate precision is reached by scanning Ka doublet in a few minutes and simply noting any displacement of peaks compared with peaks from an unstressed specimen; higher precision can be reached with slower scans or more detailed analysis of the peaks. Tests with embedded metallic particles were successful when the particles were (A) distributed throughout a moulded polymethyl methacrylate (Lucite) sheet of the order of a millimeter thick, alone or sandwiched between layers of particle-free material, or (B) embedded in polyester resin applied to a surface of Plexiglas bars, or (C) embedded in graphite-fiber epoxy composites in a layer at a chosen position within a specimen.

The radiation from plasmas produced by the interaction of a pulsed laser and a solid target can be made to fall in the soft x-ray regime. The x-rays can serve as an alternative to the increasingly important synchrotron radiation facilities for a variety of techniques such as Extended X-ray Absorption Fine-Structure Spectroscopy and X-ray Lithography. In addition, the x-rays are of special interest for general microradiography of thin samples.

We describe a new and reliable experimental technique for the measurement of mass absorption coefficients in the 0.1 to 1 keV energy range. In this technique, the absorbing film is supported directly on a substrate which under proton bombardment will generate the x-rays whose absorption will be measured. Results are given for thirteen different metals at the C Kα (277 eV) line.