A new quantification procedure for elemental mapping by X-ray (absorption) microscopy

In this paper, the principles of a new procedure for analytical X-ray microscopy (AXRM) are given and they apply for any kind of microscopes based on the use of conventional X-ray sources or of synchrotron radiation. Over the differential approach, its advantages are to minimize the number of irradiations to be used and its ability to map elements (or species) even when the investigated photon energy range does not include the threshold energy of some components. An additional advantage is that it permits to distinguish between thickness contrast and chemical contrast of the initial images via the thickness mapping. The factors influencing the precision on the concentrations measurements are discussed and it is shown that the sensitivity may reach 10-5 at/at. for the detection of medium elements embedded in very light matrices for photons in the 5-20 keV range. In fact, the measured intensities may be influenced by fluorescence effects and by the possible non-monochromaticity of the incident beams, mainly when classical X-ray sources are used (such as in X-ray projection microscopy) and correction procedures dealing with these effects are given. Some concepts developed here may also be adapted to conventional X-ray radiography and tomography