1. A.N. Sevchenko Institute of Applied Physical Problems of Belarusian State University, Kurchatov Str. 7, 220045 Minsk, Belarus
2. Maria Curie-Skłodowska University, Pl. M. Curie-Skłodowskiej 1, 20-031 Lublin, Poland
3. Belarusian State University, Nezavisimosti Av. 4, 220030 Minsk, Belarus