A.V. Belousov - Ph.D. (Phys.-Math.), Associate Professor, Faculty of Physics, Lomonosov Moscow State University E-mail: belousovav@physics.msu.ru A.A.Belianov - Junior Research Scientist, Faculty of Physics, Lomonosov Moscow State University G.A.Krusanov - Post-graduate Student, Faculty of Physics, Lomonosov Moscow State University E-mail: krusa-nov@physics.msu.ru A.P. Chernyaev - Dr.Sc. (Phys.-Math.), Professor, Head of Department, Faculty of Physics, Lomonosov Moscow State University