Thick target elemental analysis of organic and inorganic materials by PIXE using thin film standards

Abstract Modification of a mathematical procedure developed by Reuter et al. in 1975 allows the use of thin target reference standards to compute thick target elemental concentrations. The computer program is used in conjunction with the HEX program for X-ray spectrum resolution, and it takes account of both proton energy loss and X-ray attenuation by the target as they depend on target composition. These are determined by the target mass which includes the elements measured by PIXE and an additional low Z component which is calculated from observed X-ray line intensities. The sum of concentrations is constrained to equal 100%. The procedure has been applied to the PIXE analysis of a set of US Environmental Protection Agency polymer film elemental standards and of three US National Bureau of Standards standard reference materials irradiated as pressed pellets for 15 min at 1.58 and 2.52 MeV proton beam energy. The resulting composite spectra are resolved for elemental concentrations down to 1 ppm with good agreement with certified values.