Contribution of secondary fluorescence in the lateral resolution of a PIXE microprobe

Matrix effects on the measurement of elements having close atomic masses using -PIXE are studied with emphasis to Ni and Co inclusions in iron matrices. Postulating that all the major components may be simultaneously detected through at least one well-isolated peak for each of them, and that a known reference material is available which contains all the elements of the unknown sample, we propose a direct method to extract the actual distribution of all elements during the scanning with a narrow microprobe.