1. Department
of Energy Technology Royal Institute of Technology, 100 44 Stockholm, Sweden
2. Department
of Physics Gubkin Russian State University of Oil and Gas, 119991 Moscow, Russia
3. Institut
für Beschleunigerphysik und Technologie (IBPT), Karlsruhe Institute of Technology, 76021 Karlsruhe, Germany
4. Bayerisches
Geoinstitut, University of Bayreuth, D-95440 Bayreuth, Germany