Particle induced X-ray emission - relative yield ion energy dependence, an IBA chemical speciation method

The dependence of ion induced K and L shell relative yields upon the chemical composition of the target is a well-known effect. Nevertheless, its use in applications is quite recent and needs more development. In this work, the variation of the W L X-ray spectra on incident ion beam energy is presented for three different W chemical compounds. It is shown that for thick targets, the X-ray line relative intensity dependence on the ion beam energy produces variation patterns that contain information on the chemical species composition of the target. It is further shown that each of these patterns can be made to correspond to a vector in a hyperspace, in such a way that the angle between any two of these vectors is large, an important point when aiming at the use in samples of unknown composition.