Fundamentals of ion-matter interactions

One of the key parameters for many techniques using ion beams is the energy the ion transfers to the material. This energy transfer is often quantified as a stopping power (= mean ion energy loss per travelled path length), and we study this quantity for different ions and materials relevant for scientific or technological applications. We are regular contributors to the stopping power database of the International Atomic Energy Agency (IAEA).

We have a specific focus on excitations of sample electrons in the low and medium-energy regime (this means that the incoming ions are accelerated with a few to a few hundred kV), which is historically less studied and where interactions are much more complex than at higher ion energies. One of the long-term goals of our research is to go deeper than describing these interactions by a mean energy loss and go towards a local and dynamic picture of ion-solid interactions. Already now, we can perform experiments in which we select specific ion paths by using samples in which the atoms are ordered – crystals. We are also looking at secondary particles such as electrons as well as ion charge states, which can provide information about the last few interactions of an ion when travelling through a sample.

Other research topics include interatomic potentials at low energies as well as the influence of the ion charge state on energy transfer to the sample at different primary energies.

Selected publications