1. Department of Physics and Astronomy, University of Aarhus, 8000 Aarhus C, Denmark
2. Institute for Storage Ring Facilities at Aarhus, University of Aarhus, 8000 Aarhus C, Denmark
3. Department of Physics and Astronomy, Queen’s University Belfast, Belfast, BT7 1NN, United Kingdom
4. Laboratoire Collisions Agrégats Réactivité-IRSAMC, Université Paul Sabatier and CNRS-UMR 5589, 31062 Toulouse Cedex, France