Leontovich, Mikhail

Born Feb. 22 (Mar. 7), 1903, in Moscow. Soviet physicist. Academician of the Academy of Sciences of the USSR (1946; corresponding member, 1939). Son of A. V. Leontovich.

In 1923, M. A. Leontovich graduated from Moscow University. He then became a member of the commission for the study of the Kursk Magnetic Anomaly. Beginning in 1929 he was a research worker at the institute of physics of Moscow University. In 1934–35 and from 1955 to 1971 he was a professor at Moscow University. From 1934 to 1941 and from 1946 to 1952, Leontovich was at the Institute of Physics of the USSR Academy of Sciences. In 1951 he began working at the Institute of Atomic Energy.

Leontovich’s main works deal with the theory of the molecular scattering of light (scattering by the surface of a fluid, Raman scattering, the polarization of scattered light), acoustics (the theory of absorption of ultrasound in gases and liquids and of sound in electrolytes), and the theory of oscillations (self-oscillating systems, parametric resonance, adiabatic invariants). In 1928 he developed the theory of the tunnel effect together with L. I. Mandel’shtam. Leontovich’s works on statistical physics (the theory of fluctuations, the thermodynamics of nonequilibrium states) are also of fundamental importance.

In radio physics, Leontovich established the approximate boundary conditions, developed the method of general wave diffraction, and, together with V. A. Fok, worked out the theory of propagation of radio waves around the earth. He is the author (with M. L. Levin) of fundamental works on the theory of thinwire antennas. In 1951, Leontovich became head of theoretical research in plasma physics and of work on the problem of controlled thermonuclear fusion. He is the author of a number of works on plasma dynamics [confinement of a plasma filament in a conducting housing, the stability of a flexible current-carrying conductor in a magnetic field (with V. D. Shafranov), the inertial theory of plasma filaments (with S. M. Osovets)]. He established the school of Soviet theoreticians in radio physics and plasma physics. A recipient of the Lenin Prize (1958), he has been awarded three orders of Lenin, four other orders, and various medals.