Proton induced X-ray emission (PIXE) analysis on thick samples exemplified on the rare earth elements. Pt. 1

Proton Induced X-ray Emission (PIXE) analysis calibration curves (i.e. intensity of analytical signal as a function of concentration csub(i)) are determined on thick solid samples with rare earth element concentrations csub(i) <= 0.3 g/g. The calibration curves are linear at low concentrations csub(i) <= 0.3 weight% at proton energies 1.7 <= Esub(P)sub(O) <= 2.5 MeV. The precision of the quantitative analysis amounts to +- 4%. The shape of the curves at higher concentrations may be understood by simple qualitative considerations. Distortions by interelement-effects caused by additional other rare earth elements j in concentrations csub(j) <= 2 weight% are not detectable. The agreement between the experimental and the calculated intensities for different matrices is very good at low concentrations csub(i) <= 1 weight% of analyte. (orig.)