[1] Institute of Physics and Astronomy, University of Aarhus, DK-8000 Aarhus C, Denmark
[2] Institute for Storage Ring Facilities, University of Aarhus, DK-8000 Aarhus C, Denmark
[3] Départment de Physique, Université de Montréal, Montreal, Que. H3C 3J7, Canada
[4] Department of Molecular Biology, University of Southern Denmark, Odense University, DK-5230 Odense M, Denmark