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.

The operation of a new polycrystalline phase identification method using the IBM Series/1 minicomputer is described. Data of the unknown can be entered by automatic transfer of previous runs, stored data sets and manually. Full screen menu selections are provided to facilitate operations and correct entries. Typical S/M time for a multi-phase inorganic mixture containing 43 reflections using a 0.3° window averaged 11 sec per 100 standards and with simple chemical prescreening less than 4 sec including program initialization and calculations of comprehensive figures of merit. Interactive options provide graphics terminal comparison of the unknown pattern with selected standards which appear as diffractometer patterns, subtraction of identified standards from the unknown and others. Utility programs permit storing data sets for later analysis, user created files and a program to display any file standard as a diffractometer pattern.

A new apparatus and technique are described for borate flux fusion of rocks for x-ray fluorescence analysis. The method yields homogeneous, strain-free glass discs with flat, smooth surfaces that do not require polishing. The technique is adapted from several previous methods but has advantages over each in terms of sample uniformity, quality of the discs, or capital cost. The ignited rock powder is fused with flux over a burner mounted on a stock laboratory mixer, and is cast into a solid flat, polished Pt-Au mold. The very effective mixing action ensures homogeneity An oxidizing atmosphere, which is necessary to prevent loss of iron to the crucibles, is maintained by injecting air during fusion.

There is no significant loss of alkali metals during fusion, and negligible loss of flux. Duplicate samples of several rock types show excellent reproducibility, approaching counting statistical errors, for 10 major elements.

A requirement exists in the aeronautical industry for measuring temperature non-invasively in critical components, such as the turbine disc in an operating engine. Neutron diffraction, unique among nuclear techniques, offers the possibility of measuring both temperature and strain within an operating engine by virtue of the high penetration of neutrons through industrial materials. Static diffraction experiments on Waspaloy and Ti6A14V showed, by comparison with thermocouples, that both the diffraction peak position and the peak intensity can measure the tempeiaturc to within ±6 K aL 800 K. Measurements on a rotating Waspaloy disc, heated from its rim, showed that temperature gradients could be determined accurately by lattice parameter measurements. The large grain size in Waspaloy prevented accurate peak intensity measurements in this dynamic test. Finally, the structures within a small Pratt & Whitney engine in its equatorial plane were mapped by mounting the engine on an X-Y translator on the diffractometer and moving it through a grid of positions. Possible future directions in the field will be discussed.

One of the areas of X-ray powder diffraction receiving considerable attention in recent years is quantitative analysis. This analysis depends on an accurate measurement of integrated diffraction line intensities. In order to study the accuracy of these measurements we have calculated integrated intensities from single crystal data for single substance powders and compared them to experimental data obtained in our laboratory.

Recent advances in semiconductor particle detector resolutions along with new electronic circuitry associated with these detectors make possible their application in nondispersive elemental analysis. The use of radioactive sources for exciting the characteristic X-rays provides highly stable systems which can be used to accumulate data for prolonged periods. Due to the inherent stability of the detector and the excitation source, the only limitation in sensitivity is the ability to accumulate statistics above the background of scattered counts. Since this method of analysis is nondispersive, it has the capacity to determine many elements simultaneously. Solutions composed of mixtures of three or four elements were studied. The elements selected were bromine, rubidium, and strontium. These elements exhibit wide variations in mass absorption coefficients for the various characteristic X-rays emitted. The concentrations of the elements in solution varied from 10 ppm to 5% by weight. The relative intensities of the characteristic X-ray lines were compared with the concentration of the solutions to establish sensitivity curves and to study linearity of response as well. The interelemental interference was studied and the effect was evaluated for the particular elements under study. Means were developed for predicting and correcting for matrix effects.

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.

Wires of 18 different metals were exploded in nitrogen by the discharge of a 20-μF capacitor bank charged to 10 kV. The resulting aerosols were collected under nitrogren on membrane e filters, which were mounted on glass slides and used directly in the sample holder of a recording X-ray diffractometer. The X-ray data were analyzed to determine the composition and approximate crystallite size of the particulates produced by the wire explosions in nitrogen and subsequent exposure to air.

Nitrides are found as reaction products from the explosion in nitrogen of aluminum, iron, indium, tantalum, thorium, uranium, tungsten, and zirconium. No nitrides were detected in the samples from cadmium, copper, magnesium, molybdenum, lead, and tin explosions, although such nitrides are known to exist; and the aerosols produced in nitrogen by the explosion of silver, gold, molybdenum, platinum, and tin consist almost entirely of metal particles. Oxides are attributed to contamination of the nitrogen or exposure of the samples to air.

Most of the crystallites observed are less than 1000 Å as determined from X-ray line broadening find confirmed in some instances by electron microscopy. For the UN2 and ThO2, crystallite sizes of the order of 130 Å and 50 Å, respectively, are observed. In samples comprised of a mixture of phases, the constituents usually have different mean crystallite sizes. The crystallite size is not affected dramatically by the ambient nitrogen pressure or voltage used.

Traditionally users of x-ray spectrometers have been forced to optimize their instrument for light element analysis and heavy element analysis through the choice of either a light or heavy element anode. The advent of the rhodium tube brought some relief to this situation, but some compromise was still required. The recent addition of the scandium side-window tube to the range has provided twice the excitation efficiency of the chromium tube, whilst providing an equivalent heavy element performance.

In the past there have been attempts to produce x-ray tubes combining the properties of both light and heavy element tubes. An example of this is the dual-target tube which has two preferentially excited targets (anodes) of different materials constructed side-by-side.

A compact, high-intensity pulsed soft X-ray system has been used to study the response characteristics of a plastic scintillation phosphor (NE-102). In particular, the decay characteristics of this phosphor plated on one surface with a thin (<1000 Å) layer of aluminum were investigated. Although, absolute calibration of the X-ray source had not been performed, estimates of X-ray scintillation efficiency were obtained, using two separate methods, which were in agreement to within a factor of two.

The primary purpose of this cursory program was to establish the validity of transferring calibration data from plated to unplated NE-102 scintillators employed in a photometric recording system. The results of the ensuing investigation indicated the equivalence of the two, but revealed several interesting and unsuspected phenomena. These were (1) an apparent scintillation light reflectance component of zero from the plated aluminum “mirror” surface, (2) a change in pulse waveform from electron beam input to scintillation light output, and (3) a 90-nsec delay between electron beam and photomultiplier signals. The methods employed in obtaining and verifying these data are subject to errors from uncertainty in the characteristics of several components employed in the experimental setup. These uncertainties and other measurement errors caused independent estimates of the external scintillation light efficiency to range from 0.1 to 0.2 %.

Other potential applications of a pulsed soft X-ray system to measurement problems in industry and research include dynamic studies in the fields of X-ray crystallography, instrumental methods of materials analysis, and radiography of low-density subjects.

For more than a decade the Institute of Geological Sciences has carried out large-scale geochemical analysis in pursuit of mineral exploration and regional geochemical reconnaissance programmes for the Department of Industry. Over this period an XRF analytical system has been developed to meet part of this requirement for multielement data. The elements of interest range from the fourth period to uranium, and have become more numerous as exploration and analytical techniques have expanded. In particular, additions have been made of those elements such as arsenic, molybdenum and tungsten which are more difficult of determination by conventional methods.

The use of coal, as either a primary energy source or as a source of feedstock chemicals, has been complicated by the noxious and toxic chemical species formed in its gaseous effluents and also by the huge quantities of ash vhich result from its processing. Both the noxious gases and the ash have been the subjects of Federal legislations.

X-ray powder patterns (XRPP), composed of atom-pair and self x~ray scattering and the diffraction produced by crystalline phases, have long been used to investigate coals and particularly their combustion ashes (1-3). Over twenty different crystalline phases have recently been reported to exist in certain lignite fly ash (3). Analysis of the crystalline phases has typically been emphasized in previous papers involving coals and ashes, but the amorphous scattering has been given little treatment.

There are many investigations about thin film. However, these are limited to the surface layer thin film on substrates. It Is very important to know the characteristics of the extremely thin film itself such as surface layer thin film.

In the present paper, the first part deals with the thickness measurements of the surface layer film and substrate by means of x-ray method, and then the measurement method of their stress - strain curves and the procedure of the measurement are described. The results obtained are discussed on the basis of their stress — strain curves.

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.

An x-ray spectrometer with experimental results is herewith described using a radiosotope source Fe55 having a halflife of 2.6 years. As a result of the disintegration, the managanese x-rays are capable of exciting fluorescent x-rays of such elements as sulfur, chlorine, potassium, calcium, scandium and titanium in aqueous solutions. These elements with the Ka wavelengths ranging from 5.3729 Å to 2.7496 Å may be designated as between the very soft x-rays on the one hand and the hard x-rays on the other. The x-ray spectrometer presently described has achieved a resolution of 136 ev, FWHM.

Simultaneously, these elements have also been quantitatively determined by conventional x-ray fluorescent spectrometers. Since one of the spectrometers is designed to operate in vacuum as well as in helium or air, determination of sulfur, potassium and calcium were carried out in vacuum. Determination of chlorine was carried out in a helium atmosphere, Calcium, scandium and titanium were determined in air with an air-path spectrometer.

In the present study aqueous solutions containing these elements were used. The use of aqueous solutions has the inherent advantages of being homogeneous and free from effect of particle size.

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 previous LAMA I and II programs have been completely rewritten in this new version. Better precision and an order of magnitude increase in speed were achieved with a different numerical method and more efficient code. Fundamental parameters and/or empirical parameter calculations can be used. New routines for the analysis of oxides and other compounds of light elements, and multiple thin film layers with secondary enhancement factors are included.

Transitions from the valence electron levels into the first relatively sharp inner sub-shell levels result in characteristic x-ray emissions in the 100-200 eV region. These spectra sensitively reflect the chemical state of the atoms which are representative of the submicron thickness of the sample surface under low energy x-ray excitation and of the first few molecular layers of the sample under electron excitation.

An optimized measurement method for this 50-100 A spectral region is “based upon single crystal spectrometry using a lead stearate analyzer which has high dispersion and efficiency and an energy width of about one eV in this wavelength range. Spectra are recorded using “tuned” proportional counter detection. In the work reported here, low energy x-ray excitation is used in order to minimize the possibility of radiation damage of the sample.

Each spectrum is calibrated for both energy and instrument transmission using known, sharp M lines of elements such as molybdenum, zirconium and yttrium which will bracket the spectraj. range under measurement. A simple method has been developed for "stripping" from the measured spectra the Lorentzian crystal width and the Gaussian collimation width in order to allow an estimation to be made of the actual emission line widths as well as the relative intensities.

In this report, as an illustrative application example, S-LII, III spectra are presented for a series of sulfur compounds in "both solid, and gas states. Manne's approximate molecular orbital interpretation of the x-ray emission spectra has been adopted and extended to apply to the LII, III spectra for second row elements.

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.

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.