CODED IMAGING X-RAY MICROPROBE

An experimental comparison is presented between line scanning (coded imaging) and conventional point scanning (direct imaging), based on experience gained with an x-ray microprobe operated at the Hamburger Synchrotronstrahlungs-Laboratorium (HASYLAB) at the Deutsches Elektronen-Synchrotron (DESY). The microprobe uses synchrotron radiation to excite x-ray fluorescence radiation in the sample, which is detected by a solid-state detector and analysed for the element composition of the sample. The spatial distribution of elements, even if present only in traces, may be measured on a microscopic scale. Both methods were evaluated with regard to their imaging properties and compared with each other. The line-scanning technique is shown to have a better signal-to-noise ratio, thus achieving a superior image quality. Some sample applications are described for illustration.