Affiliation: | 1. School of Mathematics and Physics, Queen''s University, Belfast, Belfast BT7 1NN, UK;2. Institute of Physics, AS CR, Prague 8, Czech Republic;3. Centro de Fisica dos Plasmas, Instituto Superior Técnico, Lisboa, Portugal;4. Deutsches Elektron-Synchrotron DESY, Notkestrasse 85, 22607 Hamburg, Germany;5. Lawrence Livermore National Laboratory, University of California, P.O. Box 808, Livermore, CA 94551, USA;6. Department of Physics, Kohat University of Science and Technology, Kohat-26000, NWFP, Pakistan;7. Inst. of Physics, Polish Academy of Sciences, Poland;8. SLAC National Accelerator Laboratory 2575 Sand Hill Road, Menlo Park, CA 94025 USA;9. Clarendon Laboratory, University of Oxford, South Parks Road OX1 3PU, UK;10. Universite Pierre et Marie Curie, UMR 7605 case 128, 4 Place Jussieu, 75252 Paris Cedex 05, France;11. Lawrence Berkeley National Laboratory, 1 Cyclotron Road Berkeley, CA 94720 USA |