10.6084/m9.figshare.1012793.v1 C M Heirwegh C M Heirwegh I Pradler I Pradler J L Campbell J L Campbell Target origins, purity levels and PIXE analyses of trace elements IOP Publishing 2013 PIXE analyses yield purity levels FFAST predictions XCOM attenuation coefficients oxide form light elements Hartree parameters computations light element absorbers kev National Institute Technology XCOM XCOM values trace elements Atomic Physics Molecular Physics 2013-09-06 00:00:00 Dataset https://iop.figshare.com/articles/dataset/_Target_origins_purity_levels_and_PIXE_analyses_of_trace_elements/1012793 <p><b>Table 2.</b> Target origins, purity levels and PIXE analyses of trace elements.</p> <p><strong>Abstract</strong></p> <p>Proton-induced x-ray emission (PIXE) was used to assess the accuracy of the National Institute of Standards and Technology XCOM and FFAST photo-ionization cross-section databases in the low energy region (1–2 keV) for light elements. Characteristic x-ray yields generated in thick samples of Mg, Al and Si in elemental and oxide form, were compared to fundamental parameters computations of the expected x-ray yields; the database for this computation included XCOM attenuation coefficients. The resultant PIXE instrumental efficiency constant was found to differ by 4–6% between each element and its oxide. This discrepancy was traced to use of the XCOM Hartree–Slater photo-electric cross-sections. Substitution of the FFAST Hartree–Slater cross-sections reduced the effect. This suggests that for 1–2 keV x-rays in light element absorbers, the FFAST predictions of the photo-electric cross-sections are more accurate than the XCOM values.</p>