V.V. Borisov - Research Scientist, Skobeltsyn Institute of Nuclear Physics, Lomonosov Moscow State University Е-mail: borvv1947@mail.ru N.I. Sushentsov - Ph.D. (Eng.), Associate Professor, Leading Research Scientist, Volga State University of Technology (Yoshkar-Ola) S.A. Stepanov - Research Scientist, Volga State University of Technology (Yoshkar-Ola)