1. Department of Physics, Norwegian University of Science and Technology, N-7491 Trondheim, Norway
2. Department of Plant Biology and Biotechnology, Faculty of Life Sciences, University of Copenhagen, DK-1871 Frederiksberg C, Denmark
3. Institut Laue Langevin, 6 rue Jules Horowitz − BP 156, 38042 Grenoble Cedex 9, France, and European Spallation Source ESS AB, P.O. Box 176, 22100 Lund, Sweden