Buy article online - an online subscription or single-article purchase is required to access this article.
research papers
It is possible to obtain essentially monochromatic spot profiles with a single-crystal diffractometer by using the specimen crystal as a dispersive element, and by carrying out an ω/θ integration scan with restricted detector slits. An expression for the detector slit width is derived and the technique is tested experimentally. It appears that there is little difficulty in monochromating to ± 1% of the nominal X-ray wavelength as a routine procedure. It is also quite straightforward to work with the Kα1 line alone for medium and high-angle reflexions. The range of wavelengths detected can be made independent of diffraction angle; integrated intensity errors due to variable spectral response can therefore be effectively eliminated. This technique facilitates a higher and more constant degree of X-ray monochromation than the pyrolytic-graphite monochromator or the solid-state detector.