Lev Andreyevich Artsimovich (25.02.1909—1.03.1973) was a Soviet physicist and an academician of the USSR Academy of Sciences (1953; a corresponding member from 1946). He was born in Moscow. He graduated from Byelorussian University in Minsk (1928). In 1930—44 he worked at the Leningrad Physico-Technical Institute of the USSR Academy of Sciences. From 1944 he was at the I. V. Kurchatov Institute of Atomic Energy, and from 1947 also professor at Moscow University.
His main work was in the field of atomic and nuclear physics, plasma physics and controlled thermonuclear reactions. His results on the processes by which fast electrons interact with matter, in particular his data on the way the intensity of bremsstrahlung and the total energy losses depend on the energy of the fast electrons, brilliantly confirmed the conclusions and predictions of quantum mechanics, which was of great importance at the time. In 1935, together with I. V. Kurchatov, he was the first to prove clearly the capture of a neutron by a proton, and in 1936, with A. I. Alikhanov and A. I. Alikhanyan, the conservation of momentum in the annihilation of a positron and an electron. He carried out a number of studies in electron optics. In the post-war years he and his colleagues developed a method of the electromagnetic separation of isotopes (the USSR State Prize, 1953).
From 1950 he headed experimental research on controlled thermonuclear fusion in the USSR. In 1952, together with his colleagues, he discovered the neutron radiation of a high-temperature plasma (the Lenin Prize, 1958), and in 1956 he established the non-thermonuclear nature of the neutrons emitted in gas-discharge pinches. Under his direction work was carried out on the Tokamak devices, which ended in obtaining a physical thermonuclear reaction. In 1968 the first thermonuclear neutrons were recorded on the Tokamak-4 device. In 1971 Artsimovich was awarded the USSR State Prize for a series of studies on producing and investigating high-temperature plasma on the Tokamak devices.
From 1957 he was academician-secretary of the Division of General Physics and Astronomy of the USSR Academy of Sciences. Hero of Socialist Labour (1969).