Analysis of lateral element distributions using the nuclear microprobe
Method:A high energetic ion beam focused to few micrometers is scanned over a sample and initiates different processes of interaction with the atoms of the target material. So the following analysing techniques can be used:
Parameters of the Rossendorf Nuclear Microprobe installed at the 3 MV-Tandetron:
||electromagnetic quadrupole triplet|
||M x E / q²=45 MeV amu|
||Protonen, nahezu alle Ionen mit Z > 2|
||> 100 pA|
||» 2 µm|
||bis zu 2 x 2 mm²|
Example of application 1:Trace element distributions on a cross section of a medieval human femur were investigated by means of micro-PIXE.
Bone structures, represented in the form of so-called lines of arrested growth, were observed. An increased concentration of the trace elements Mn, Fe, Zn, Pb and Sr and a decreased one of Ca were measured on the bone lines. The alteration of the concentration is connected with different conditions during the growth and could not be interpreted by contamination of material from the surrounding burial matrix, as suggested by other anthropologists.
Distribution of Fe and PIXE Spectra measured on and beside a bone line.
Ref.: D. Grambole, F. Herrmann, B. Herrmann, Nucl. Instr. and Meth. B 109/110 (1996) 667
Example of application 2:Hydrogen and deuterium depth profiles of a wall sample (0.5 mm tungsten on carbon) from a fusion reactor were investigated by micro-ERDA. The depth distributions were measured by line scanning the beam over a slope of the sample (wedge structure) prepared before.
Experimental set-up and depth profilesBefore cutting the sample a 70 nm thick gold layer was evaporated onto the surface to identify the slope. The gold was measured simultaneously by PIXE.
Ref.: D. Grambole, F. Herrmann, R. Behrisch, W. Hauffe
Proceedings of the 6th Intern. Conf. on Nuclear Microprobe Technology and Applications, Cape Town, South Africa (1998),
to be published in Nucl. Instr. and Meth. B.