The nuclear microprobe: A complementary tool to NAA characterization

Abstract

The nuclear microprobe enables the localization and the quantitative determination of all elements from hydrogen to uranium using atomic and/or nuclear methods: PIXE, PIGE, RBS, ERDA, NRA, STIM, etc. These methods and the apparatus required are shortly described. Three examples show that complementary information is obtained by nuclear microprobe analysis and NAA. The first example is the study of the abnormal behavior of metallic impurities during the purification of metallurgical grade silicon by directional solidification. This behavior is due to the presence of silicon carbide micro-precipitates at the bottom of the ingots. The second example concerns the determination of trace element (Ni, Mn, Rb, Sr) partition coefficients between a solid phase (mineral) and a liquid phase (lava-glass inclusions). These determinations enable the specification and modelling of the processes which govern the magma evolution in volcanological contexts. The third example deals with the study of trace elements in archeological bones. Using PIXE, PIGE, NRA and NAA, it is possible to correlate the concentrations of some elements, such as C, N, F, and Zn in the femoral diaphyse with both the age, the pathology and diagenetic mechanism of the human being at the moment of death.