Ion Beam Facility

What happens to materials under exposure to the extreme wall conditions in a nuclear fusion reactor? How to investigate the structural effect of catalytic materials to ease chemical reactions? DIFFER exploits a unique Ion Beam Facility (IBF) that allows for non-destructive characterization of (sub-)surface material properties and for non-perturbing investigation of processes in materials for fusion energy and solar fuels.

Ion beam analysis (IBA) techniques form a powerful family of methods to obtain elemental depth profiles in (generally) solid materials. Fields of interest vary from profiling elemental distributions with several microns probing depth to the determination of the composition of thin films of sub-monolayer thickness. The results are easy to interpret and, in contrast to the results of many other techniques, unambiguously quantifiable. The variety of IBA techniques (see table 1) makes use of different types of ion-atom interactions. This results in the capability to determine chemical compositions covering the entire periodic table with good elemental identification, quantification and sensitivity.

The Ion Beam Facility (IBF) at DIFFER is built around a 3.5 MV Singletron ion accelerator, in which lightweight ions are extracted from an RF plasma and accelerated electrostatically over (at most) 3.5 MV. The beam of ions formed this way, is filtered, steered and focused by magnets to an experimental setup of choice, where it allows for non-destructive and non-perturbing investigation of materials for fusion and for solar fuels, thereby bridging the two DIFFER research themes:

  1. The direct connection to Magnum-PSI allows for in vacuo determination of the chemical composition and changes in the near surface of nuclear fusion reactor materials as a result of plasma exposure.
  2. The connection to the upgraded Pilot-PSI facility will enable in situ and operando studies of materials under extreme conditions in energy systems. [under development]
  3. The availability of a local, in-house user station for Ion Beam Analysis allows for interactive development of novel materials for all research projects at DIFFER.

Table 1: Overview of applicability of IBA techniques


Left: Plasma source from which the ions are extracted. Center: Accelerator tank which contains a high voltage generator, plasma source and accelerator tube. Right: Main beam line showing the exit of the accelerator tank (top center), the 90º analyzing magnet (left) and the switch magnet (lower right corner)