Development of low-energy x-ray fluorescence micro-distribution analysis using a laser plasma x-ray source and multilayer optics?

A new technique is presented for low-energy X-ray fluorescence micro-distribution analysis of low-Z elements at micrometer spatial resolutions. The technique is based on the use of a laser plasma X-ray source and spherically curved multilayer optics. A large collimator is used to focus the light from the laser plasma on the sample and a Schwarzschild mirror set is used to image the fluorescent radiation on a 2D CCD unit. A first system, now under development, is designed for detection of the carbon K alpha-line. The system consists of a Cr/Sc collimator of 260 mm diameter, focusing 0.7 sr of the light from the plasma on the sample, and an Fe/C Schwarzschild mirror set with 20 x magnification for detection of the carbon in the sample. A resolution in the micrometer range is expected to be achievable, with a detection limit of a few per cent. Upgrading of this system is expected to result in sub-micrometer resolution and a detection limit in the ppm range.