1. Jülich Centre for Neutron Science (JCNS-1) and Institute for Biological Information Processing (IBI-8), Forschungszentrum Jülich GmbH, 52428 Jülich, Germany
2. Felix Bloch Institute for Solid State Physics, Leipzig University, 04103 Leipzig, Germany
3. Institut Laue-Langevin (ILL), 71 avenue des Martyrs, 38000 Grenoble, France
4. Jülich Centre for Neutron Science (JCNS-2) and Peter Grünberg Institute (PGI-4), Forschungszentrum Jülich GmbH, 52428 Jülich, Germany