PIXE (Proton Induced X-Ray Emission) using a nuclear microprobe is an analytical technique to analyse major to trace elements in solids with a micrometric to nanometric spatial resolution. Because of the range of protons in solids (e.g., typically around 70 µm in alumino-silicates), this technique allows any solid or fluid µ-inclusion placed along the beam path to be analysed. Multi-elementary PIXE (11Let us consider the p geometrical detection parameters of a PIXE setup and a solid chemical standard the PIXE spectrum of which yields the peaks of N detectable certified elements (N>>p). The computer-assisted PIXE spectrum treatment yields N values of G(E), from which the p detection parameters can be adjusted by a least-square fit procedure. The method is illustrated using a natural basalt standard provided by the SARM laboratory (Nancy, France).17 certified elements from Al to Ba are detected on its PIXE spectrum using an Al-Be ‘funny filter’. The 4 geometrical detection parameters are adjusted to within ±2 to 6 % on the standard spectrum using the Levenberg-Marquardt algorithm.
We show that, by combining RBS (Rutherford Back-Scattering) and PIXE measurements, quantitative PIXE can be applied to intracrystalline inclusions placed within the range of protons, as RBS spectrometry provides the geometrical information required for the quantitative treatment of PIXE spectra of occluded phases.