1. School of Physics, University of Nottingham, Nottingham NG7 2RD, United Kingdom
2. Department of Physics and Astronomy, Aarhus University, Ny Munkegade 120, DK-8000 Aarhus C, Denmark
3. Synchrotron SOLEIL, Saint-Aubin, BP 48, 91192 Gif-sur-Yvette, France
4. Division of Synchrotron Radiation Research, Department of Physics, Lund University, P.O. Box 118, 221 00 Lund, Sweden