1. Nuclear Physics Institute, The Czech Academy of Sciences (CAS), 25068 Rez, Czech Republic
2. Department of Physics, Faculty of Science, University of J. E. Purkyně, Pasteurova 3544/1, 40096 Ústí nad Labem, Czech Republic
3. National Institute of Nuclear Physics-INFN, Sezione di Catania, Via S. Sofia 64, 95123 Catania, Italy
4. Department of Metals and Corrosion Engineering, University of Chemistry and Technology, 16628 Prague, Czech Republic