1. Experiments Division, European Synchrotron Radiation Facility, 71 Avenue des Martyrs, CS40220, 38043 Grenoble Cedex 9, France
2. OCAS, Pres. J.F. Kennedylaan 3, BE-9060 Zelzate, Belgium
3. Lawrence Livermore National Laboratory, Physics and Life Sciences, Physics Division, 7000 East Avenue, L-487, Livermore, California 94550, USA
4. Department of Physics, Technical University of Denmark, 2800 Kgs. Lyngby, Denmark