Detection of actinides and rare earths in natural matrices with the AGLAE new, high sensitivity detection set-up

摘要

A series of granite samples (Grimsel and AEspoe) enriched by sorption with ~(nat)U (10~(-3) M, 10~(-4) M, 10~(-5) M in solution) and La (10~(-3) M, 10~(-4) M in solution) has been scanned by PIXE over a surface of 1920 × 1920 mm~2 together with non-enriched Grimsel and Aspo granites and a glass standard. An assessment of minimum detection limits, MDL's, for several elements has been performed with the use of standard materials. Due to mapping and the high sensitivity of the new AGLAE detection system, U levels around 30 ppm can be detected from the whole PIXE spectrum (one low energy detector and four summed filtered detectors) while U reach grains, inhomogeneously distributed over the surface can be clearly identified through the multi elemental maps and analyzed separately. Even the nominally enriched samples have La levels below the MDL, probably because precipitation of the element (and not adsorption) mostly took place, and precipitates were eliminated after surface cleaning carried out before PIXE analyses.