Imaging Techniques for X-Ray Fluorescence and X-Ray Diffraction

Electron induced X-ray mapping together with modern SEM/EDX analysis systems has reached a high level of perfection due to established methods of beam deflection and focusing and today's standard in energy dispersive X-ray detection and data processing. X-ray analysis of specimens based on X-ray excitation (XRF/XRD) is routinely performed on comparatively large specimen areas without conserved spatial information. XRF-/XRD-imaging capabilities are not yet commonly available on standard spectrometers, since both suitable X-ray optical elements are missing and there is a large intensity loss due to the necessary primary beam collimation.</jats:p

X-Ray Imaging

Element mapping has been so far an analytical field covered by those investigation methods using a scanned particle beam on the excitation side of the specimen. These methods include localized interaction processes, as in the electron microprobe, secondary ion mass spectrometer and Auger electron spectrometer. On the other hand, methods which use a stationary radiation beam on the input side (non-localized interaction) usually give summarized information about the sample area (X-ray fluorescence spectrometry, photoelectron spectrometry, …). This paper deals with an approach to extending the application field of X-ray fluorescence analysis (XRFA) to element mapping. Fig. 1 shows the main components of the X-ray imaging system. Since modern SRF systems often work under computer control, the only additional hardware components of the system are a scanned sample holder and an X-ray source producing a line-shaped X-ray beam. The computer is usually not used for ease, speed or convenience of operation, but is used to generate the element image and process all the collected fluorescence data.</jats:p