Methods and instrumentation
The group Ion Beam Analysis (IBA) has a strong methodological approach. We are developing nearly unique analytical methods within interdisciplinary research projects using and constructing ourselves newest technology. Our actual research projects focus on:
Theoretical background of ion beam analysis (IBA)
In general, all ion beam analysis methods are based on three individual steps (here an example of Elastic Recoil Detection (ERD) of 10Be using a C-beam - in German only):
1. Extraction of ions
2. Acceleration of ions
3.Detection of ions
For the classical IBA-methods such as RBS, PIXE/PIGE, NRA, and ERD samples are bombarded by ions like "billiard balls". Samples are arranged at the end of the beamline and particles and radiation emitted from the sample are detected.
For the mass spectrometry methods such as AMS and Super-SIMS samples are mounted in the ion source and extracted ions from there are directly detected.
Why chemical analysis at the ultratrace level for resource technology research?
Analytical geochemistry is a key issue for understanding the formation of mineral deposits and their exploration. However, the concentrations of chemical elements in the Earth crust are very often only very low.
Several processes in nature yield to large enrichments and "cleaning" of these elements - geochemical anomalies and, in extreme cases, mineral and metal ore deposits are the results.
As nearly every geological, but also biological processes, can account for these formations, the search for the resources are hindered. The chemical analyses of trace and ultratrace elements of different geochemical behaviour supports the finding of mineral deposits in two particular ways:
- Based on the chemical composition of minerals and rocks and their physical properties, geoscientists develop models for the different types of mineral deposits. The decryption of the individual, but often – in space and time – overlapping processes is only achievable through the analysis of the whole elemental spectrum. This needs to include also ultra traces as specific elements behave differently during the individual processes.
- As most reachable ore deposits in industrial countries are nowadays already exhausted, the search and exploration is concentrated on hidden sources. Visible hints for their existence are often only very small enrichments in the minerals of the overlaying rocks, so-called geochemical halos.
The analytical methods of the group "Ion Beam Analyis", especially Ion Microprobe and Super-SIMS, open new and interesting opportunities for (ultratrace) chemical analysis.