Proton induced monochromatic X-rays: a technique for solving interference problems in X-ray fluorescence analysis

摘要

with PIXE and EDXRF techniques excellent senstivites for most of the elements in a wide range of matrix sample compositions can be obtained. Despite this, in some cases, strong interferences originating from the presence in the matrix of an element with high concentration, can limit these sensitivities considerably. A combination of the above techniques, PIXE and XRF, seems to be the most efficient solution to this problem. By choosing the primary target properly, protons can produce an intense, almost monoenergetic exciting X-ray radiation, which in several cases selectively excites the elements of interest in the sample and overcomes the roduction of X-rays of the element dominating the matrix. The application of this technique to specific interference problems, either in the characterization of thin films deposited onto various substrates (YBaCuO film onto LaAlO_3 crystal and a MgF_2 film onto a SiO_2 matrix) or in the determination of trace elements in a high Z thick matrix (copper) is discussed.