The recently developed code SHAPE allows the build-up of EDXRF spectra for collimated and monochromatic excitation. In this work the code is applied to investigate the Importance of the scattering corrections to the more intense XRF characteristic lines from low and medium Z elements. Results are given graphically for pure elements from Z=11 (Na) to Z=42 (Mo). Heavier element lines from a multi-component geological sample, where light matrix amplifies the influence of scattering, are studied.

The introduction of various atoms into crystal surfaces by ion implantation has become common practice in the research laboratory and in many industrial processes. The deceleration of the introduced foreign ions during implantation results in extensive lattice damage. Atom displacement from equilibrium crystal sites and pile-up of the new atoms take place. The use of the pulsed laser for annealing these atomic defects in a single crystal is well documented . The absorption of the total energy in the laser pulse can be rapidly transferred to the lattice, approximately 10-9s, for an elevated temperature anneal of the damaged crystal. The photon energy of the monochromatic laser beam can be tailored so that the absorption of the radiation by a specific crystal can “be matched for its penetration into the crystal to that of the depth of the implanted atoms. A highly efficient mechanism is thus utilized to anneal just that portion of the crystal which is damaged by the impinging atoms of the implant.

Techniques of mineral analysis by fluorescent X-ray spectrography can generally be classified on the basis of (1) extensive sample preparation and simple instrumental examination, (2) simple sample preparation and extensive instrumental examination, (3) extensive processes for both, or (4) simple processes for both major phases of the technique. The latter type of technique is usually the most commensurate with the concept “maximum information with minimum effort.”

Suitable analytical results with multielement calibration systems for random mineral samples can be obtained if there are valid considerations of the relevant absorption and enhancement effects or if the systems are based on general procedures to minimize absorption and enhancement effects. Preliminary investigation indicated that control of sample mass and use of thin films of the mineral sample is a convenient and simple method of minimizing absorption and enhancement effects.

Successful application of thin-film samples with known masses in a multielement calibration system is highly dependent upon details of sample preparation and comprehensive studies of these details will be discussed.

The calibration system is suitable for the determination of minor and major concentrations in the sample, but it is not recommended for determination of trace concentrations.

The study of the mechanical behaviour of materials by X-ray measurements in a classical laboratory is limited by the possibilities of the X-ray tubes used. Some crystallographic planes are not conducive to good diffraction conditions and the radiation characteristics' may not be optimum. The use of synchrotron radiation resolves many of these problems by providing a continuously variable wavelength which allows measurements of stress and stress gradients to be carried out in very good conditions. The high intensity and perfectly monochromated radiation with a small beam divergence are very helpful for microstrain measurements.

Synchrotron X-radiation provides unique opportunities for diffraction experiments and, therefore, for extending our understanding of the structure - property interplay in catalyst systems. The present status of opportunities and applications of synchrotron X-ray diffraction techniques in the structural chemistry and catalysis science areas is overviewed, and illustrated by selected recent results.

A critical discussion of the equivalent wavelength representation of polychromatic primary radiation as applied to the fundamental parameters method is given. This representation raises problems with appropriate selection of equivalent wavelengths and with accurate calculation of secondary fluorescence. Methods for reducing these difficulties are discussed and have been incorporated into a mini-computer program which achieves reasonable accuracy for alloy test cases.

White beam transmission topography was used to image defect structures in gallium arsenide single crystal substrates representative of those used for microwave integrated circuit fabrication. A scanning topographic camera was developed for Beamline X-19C at the National Synchrotron Light Source. Acquiring film topographs within a particular range of scan rates and x-ray fluxes was found to produce distorted images. The distortions were shown to be thermoelastic, arising from inhomogeneous deposition of thermal energy through the absorption of residual x-rays. The problem could be circumvented using faster scans with some sacrifice in spatial resolution. Real time electrooptic topographs were recorded using x-ray fluxes about one percent of those used for the film topographs. The potential for reducing the flux requirement to even lower levels which would be accessible to flash x-ray generators is considered.

A method for the direct determination of trace elements in light element matrices is described. The intensity of Compton scatter of the incident X-rays from the specimen was used to evaluate the apparent absorption factor for the direct correction for matrix effects. This permits the use of single element standards for samples of varied and complicated matrix composition. Relative errors of approximately 5% were obtained for results in the concentration range of 10-200 ppm.

The combination of an improved resolution, gas proportional detector with advanced microprocessor technology provides a new and unique solution to the problem of alloy analysis.

A field portable, microprocessor controlled, fully user-programmable x-ray analyser is described for fast, reliable, on-site, positive alloy identification and assay. The radio-isotope based analyser employs a modified Lueas-Tooth and Price model of intensity corrections for quantitative, multielement analysis. Applications are reviewed and include examples to show the superior performance of the instrument in such difficult eases as sulfur in carbon steels, and titanium and nickel in stainless steels.

Discussion of the unique alloy identification scheme and its underlying principles is followed by examples of applications illustrating the capabilities of the instrument in distinguishing, in 5 seconds, alloys of closely similar compositions such as stainless steels 303, 304 and 321, and 410 and 416.

The present paper describes an energy-dispersive x-ray fluorescence method for measuring tin in bis(tri-n-butyl)tin-oxide impregnated wood. The proposed method is of the backscatter/fundamental parameter type. Its versatility, precision, and accuracy is demonstrated by analyses of eleven samples of sapwood of Baltic Redwood. The results obtained are compared with those from neutron activation analysis.