1. Institute of Electronics Systems, Warsaw University of Technology, 15/19 Nowowiejska Street, 00-665 Warsaw, Poland
2. Institute of Plasma Physics and Laser Microsynthesis, 23 Hery Street, 01-497 Warsaw, Poland
3. The Institute for Magnetic Fusion Research, Alternative Energies and Atomic Energy Commission, Cadarache Research Facility, 13115 Saint-Paul-lez-Durance, France