[1] Kazimierz Wielki Univ Bydgoszcz, Inst Phys, PL-85090 Bydgoszcz, Poland
[2] Ivan Franko Natl Univ Lviv, Dept Elect, UA-79017 Lvov, Ukraine
[3] Univ Gdansk, Inst Expt Phys, PL-80952 Gdansk, Poland
[4] Polish Acad Sci, Inst Nucl Phys, PL-31342 Krakow, Poland
[5] Czestochowa Tech Univ, Inst Phys Jan Dlugosz, PL-42200 Czestochowa, Poland
[6] Natl Acad Sci Ukraine, Inst Scintillat Mat, UA-61001 Kharkov, Ukraine