1. Institute of Electronic Materials Technology, Wólczyńska 133, PL-01919 Warsaw, Poland
2. National Centre for Nuclear Research, A. Sołtana 7, PL-05400 Otwock-Świerk, Poland
3. Institute of Experimental Physics, University of Warsaw, Hoża 69, PL-00681 Warsaw, Poland
4. HASYLAB at DESY, Notkestrasse 85, D-22607 Hamburg, Germany