ENHANCEMENT CORRECTION IN HIGH-ENERGY PARTICLE INDUCED X-RAY-EMISSION ANALYSIS

The high energy particle induced X-ray emission (PIXE) method is well suited for quick quantitative analysis of nearly any sample with high accuracy and sensitivity. Nevertheless for samples with special elemental composition the so-called enhancement effect must be considered. The X-ray yield of a line energetically below a very intense line in a spectrum may be enhanced by secondary excitation due to the X-rays of the intense line. This will suggest a higher abundance of the element in the sample than is the case. This effect is investigated for high energy projectiles such as 30 MeV α-particles theoretically dependent on the X-ray energies, the elemental abundances and the target thickness. Further on the projectile energy dependence is discussed. For an experimental check three thick Fe samples containing Cr and Mn are measured. For a small admixture of e.g. Cr in a Fe matrix the analysis results can differ by a factor of about 2. In the PIXE analysis of objects, in which the exciting radiation of the main element has an energy just above the X-ray absorption edge of a minor element, the enhancement effect is not to be neglected. © 1979.