History of Science and Engineering Annotation << Back Alexandr E. Chudakov (1921–2001). Scientific portrait G.I. Merzon A.E. Chudakov was an outstanding scientist in the fields of cosmic rays and neutrino physics. He was distinguished by his innovational approach to studies of nature. He was a pioneer in the application of Cherenkov light emitted by extensive air showers for the determination of their energy and the position of their source. A.E. Chudakov has developed the method of detecting cosmic-ray by Cherenkov radiation in large water reservoirs, which has been refined later in the Baikal and Kamiokande facilities. He has also proposed to detect extensive air showers by the Cherenkov light reflected from the snow cover of Arctic and Antarctic. He has discovered the phenomenon of screening charges in the vertices of electron-position pairs, which is called now the Chudakov effect. He has realized for the first the detection of optical transition radiation. A.E. Chudakov was the first, who has detected the Earth’s radiation belts. However, being extremely critical to his own results, he has delayed the publication and has presented thereby to Van Allen the priority in this discovery. A.E. Chudakov also was one of the ideologists and heads in constructing the underground neutrino laboratory in the Baksan ravine, North Caucasus. Key words:cosmic-ray physics, neutrino physics, detection of extensive air showers by the Cherenkov light reflected from the snow, first data about existence of Earth’s radiation belts. merzon@sci.lebedev.ru