
A.E. Chudakov (June 16,1921- January 25, 2001) Aleksandr Evgenievich Chudakov, an outstanding Russian scientist in the field of cosmic ray physics passed away after a long decease on January 25, 2001 at an age of 79. A.E. Chudakov was born on June 16, 1921 in the family of E.A. Chudakov, famous scientist and engineer who was an organizer of car production in Soviet Union and vice president of the Academy of Sciences. After graduating from the Moscow University, Aleksandr Chudakov was immediately involved in investigations of cosmic rays by rockets. In one of his early papers he had predicted the effect of decreasing ionization losses for narrow electron-positron pairs, later referred to by many scientists as Chudakov effect. In 1950s he carried out a series of experiments in the Pamir mountains studying Cherenkov emission of extensive air showers in the atmosphere. Together with S.N. Vernov, he also carried out first satellite experiments on cosmic rays, which resulted in actual discovery of the Earth's radiation belts during the third Soviet sputnik flight. In 1961 the method of Cherenkov gamma ray astronomy was suggested in a paper by G.T. Zatsepin and A.E. Chudakov (a new branch of science has now been developed from this paper). This method was immediately implemented by him and his collaborators in pioneering experiments on gamma ray astronomy at Katsively, Crimea. Since the end of 1960s the activity of professor Chudakov was connected with the Baksan neutrino observatory. The construction of the Baksan underground scintillation telescope (put into operation in 1977) was accomplished under his general supervision, starting from general philosophy of experiment and including minute details of construction (he was a very rare type of a person who had simultaneously an acute intuition in theoretical problems and great talent in engineering and electronics). The Baksan telescope was one of the first (if not first) large multi-purpose facilities of underground physics, and a handful of first- class results in this field were obtained with this instrument which is still in operation. A.E. Chudakov was unquestionably one of the leading persons in cosmic ray science, and his name belongs to its history. As a professor of Moscow University he educated many young scientists. His death is a great loss for his friends and colleagues.