1. Physics Department, Ivan Franko National University of Lviv 1 , 8 Kyryla i Mefodiy St., Lviv 79005, Ukraine
2. Ukrainian Academy of Printing 2 , Pidgolosko Street, 19, Lviv 79020, Ukraine
3. Photon Science at DESY 3 , Notkestrasse 85, Hamburg 22607, Germany