Atomic & Molecular Physics Group

Ion Trapping and Mass Spectrometry for Nuclear, Atomic and Molecular Physics

Electrically charged particles can be captured and stored by use of electric and magnetic fields.
The Atomic & Molecular Physics Group develops new Ion Trapping methods as well as related Mass Spectrometric techniques for further analysis of the trapped particles.

These are applied to solve questions from various areas of nuclear, atomic and molecular research, such as

  • What are the structures of exotic, short-lived atomic nuclei?
  • More specific: How were the elements in the Universe created?
  • What are the heaviest (“superheavy”) elements and what are their properties?
  • What are the structures and properties of aggregates of a few up to several hundred or thousand metal atoms, also called metal (nano-)clusters?
  • How do they interact with photons, electrons, atoms and molecules?
  • More specific: How many extra electrons can be packed onto a cluster of a given size, i.e. how far can an isolated nano-capacitor be charged up?

Ion-trap developments and metal-cluster studies are performed at the University of Greifswald and recently also at the MPI for Nuclear Physics at Heidelberg.

The exotic nuclei are produced at accelerator facilities and have to be investigated “online”, i.e. immediately, because they decay fast, some within fractions of a second. However, this is enough time for precision mass measurements which reveal – via Einstein’s E=mc2 – the nuclear binding energies. These experiments are performed at CERN/Geneva within the ISOLTRAP collaboration and at GSI/Darmstadt within the SHIPTRAP collaboration.

The ion-storage setups include

  • radio-frequency traps, also called Paul traps
  • ion-cyclotron resonance traps, also called Penning traps
  • electrostatic ion beam traps, also used as Multi-Reflection Time-of Flight Mass Spectrometers (MR-ToF MS) as well as an
  • electron beam ion trap (EBIT)


Prof. Dr. Lutz Schweikhard
Ernst-Moritz-Arndt Universität
Institut für Physik

Felix-Hausdorff-Str. 6
17489 Greifswald

Telefon +49 3834 86-4750
Telefax +49 3834 86-4701