K.V. Belov – Post-graduate Student, Saratov State University named after N.G. Chernyshevsky E-mail: kirilltravelbox@mail.ru

T.A. Karetnikova – Ph. D. (Phys.-Math.), Assistant, Saratov State University named after N.G. Chernyshevsky; Research Scientist, Saratov branch of Kotel'nikov IRE of RAS, 

E-mail: KaretnikovaT@mail.ru

A.E. Ploskikh – Student, Saratov State University named after N.G. Chernyshevsky

E-mail: andreyploskih@gmail.com

N.M. Ryskin – Dr. Sc. (Phys.-Math.), Professor, Head of Department, Saratov State University named after N.G. Chernyshevsky; Leading Research Scientist, Saratov branch of Kotel'nikov IRE of RAS,  E-mail: RyskinNM@info.sgu.ru

G.V. Torgashov – Ph. D. (Phys.-Math.), Head of Laboratory, Saratov branch of Kotel'nikov IRE of RAS E-mail: TorgashovGV@gmail.com