SLITS AND HIGH-RESOLUTION X-RAY-DIFFRACTION

It is shown that, with proper use of an anti-scatter slit in front of the detector, the signal-to-noise ratio of a symmetric high-resolution X-ray diffraction scan can be improved by a factor of ten. By the use of an asymmetric reflection with a high angle of incidence on the sam ple, the size of the diffracted beam can be reduced sufficiently to al low for two-dimensional reciprocal-space scans with a simple slit inst ead of a crystal assembly in front of the detector for enhanced resolu tion. By selection of the proper reflection, a resolution can be chose n that suits the application. Examples include a partially relaxed SiG e multilayer and a periodic surface grating.