1. Institute of Physics, Polish Academy of Sciences, al. Lotników 32/46, PL-02-668 Warsaw, Poland
2. Lund University, MAX-lab, Ole Romers vag 1, SE-22363 Lund, Sweden
3. Institute of Electron Technology, al. Lotników 32/46, PL-02-668 Warsaw, Poland
4. HASYLAB at DESY, Notkestr. 85, D-22603 Hamburg, Germany