K, L, and M shell datasets for PIXE spectrum fitting and analysis

• Differences between several datasets commonly used by PIXE codes for spectrum fitting and concentration estimates have been highlighted.
• A preferred option dataset was selected which includes ionisation cross sections, fluorescence yield, Coster–Kronig probabilities and X-ray line emission rates for K, L and M subshells.
• For PIXE codes differences of several tens of percent can be seen for selected elements for L and M lines depending on the data sets selected.

Routine PIXE analysis programs, like GUPIX, GEOPIXE and PIXAN generally perform at least two key functions firstly, the fitting of K, L and M characteristic lines X-ray lines to a background, including unfolding of overlapping lines and secondly, the use of a fitted primary Kα, Lα or Mα line area to determine the elemental concentration in a given matrix. To achieve these two results to better than 3–5% the data sets for fluorescence yields, emission rates, Coster–Kronig transitions and ionisation cross sections should be determined to better than 3%.There are many different theoretical and experimental K, L and M datasets for these parameters. How they are applied and used in analysis programs can vary the results obtained for both fitting and concentration determinations. Here we discuss several commonly used datasets for fluorescence yields, emission rates, Coster–Kronig transitions and ionisation cross sections for K, L and M subshells and suggests an optimum set to obtain consistent results for PIXE analyses across a range of elements with atomic numbers from 5 ⩽ Z ⩽ 100.