- Nuclear physics and elementary particles
- Molecular physics and thermodynamics
- Atomic and quantum physics
Isaak Yakovlevich Pomeranchuk (20.05.1913 —14.03.1966)—Soviet theoretical physicist, academician (1964; corresponding member 1953). Born in Warsaw. Graduated from the Leningrad Polytechnic Institute (1936). He worked at the Physico-Technical Institute in Kharkov, at higher educational institutions in Moscow and Leningrad, in 1940—43 — at the Physical Institute of the USSR Academy of Sciences, in 1943-46 - at Laboratory No. 2 of the USSR Academy of Sciences. From 1946 — head of the theoretical department of the Institute of Theoretical and Experimental Physics and professor at the Moscow Institute of Engineering Physics.
His work was in the fields of nuclear physics, quantum field theory, elementary particle physics, the theory of nuclear reactors, solid-state physics, electrodynamics and the quantum theory of liquids. Together with A. I. Akhiezer he extended the first quantitative theory of the scattering of photons by the field of a nucleus (1937), constructed without the use of perturbation methods a theory of resonance nuclear reactions (1948) and a theory of the diffraction scattering of fast charged particles (1949). With D. D. Ivanenko he predicted (1944) synchrotron radiation. He made a significant contribution to the creation of Soviet nuclear reactors. Together with I. I. Gurevich he developed the theory of the resonance absorption of neutrons in heterogeneous systems, the theory of Kurchatov's exponential experiments, and the diffusion theory of the reactor (together with others), and derived the formula for the critical size. He studied the processes of neutron multiplication during moderation.
In elementary particle physics, with which he was concerned from its very beginning, he initiated the development of a new field — the physics of extremely high energies. Proceeding from an analysis of dispersion relations, he formulated (1958) a theorem of importance for the theory of strong interactions, according to which at extremely high energies the cross sections for the interaction of a particle and its antiparticle with a nucleon must be equal (the Pomeranchuk theorem). Together with others he extended the theory of the interaction of pions with deuterons, and proved the internal inconsistency of quantum electrodynamics.
He achieved weighty results in solid-state physics as well. Together with L. D. Landau he developed (1937) the theory of the electrical conductivity of metals at low temperatures. He gave a general theory of the inelastic scattering of neutrons in crystals (with A. I. Akhiezer) and constructed a theory of the thermal conductivity of dielectrics at low and high temperatures. In 1950 he predicted the effect in which, at sufficiently low temperatures, the heat of fusion of solid helium 3He becomes negative (the Pomeranchuk effect), and proposed a new method of obtaining low temperatures.
USSR State Prizes (1950, 1952). He founded a school of theoretical physicists.
His work was in the fields of nuclear physics, quantum field theory, elementary particle physics, the theory of nuclear reactors, solid-state physics, electrodynamics and the quantum theory of liquids. Together with A. I. Akhiezer he extended the first quantitative theory of the scattering of photons by the field of a nucleus (1937), constructed without the use of perturbation methods a theory of resonance nuclear reactions (1948) and a theory of the diffraction scattering of fast charged particles (1949). With D. D. Ivanenko he predicted (1944) synchrotron radiation. He made a significant contribution to the creation of Soviet nuclear reactors. Together with I. I. Gurevich he developed the theory of the resonance absorption of neutrons in heterogeneous systems, the theory of Kurchatov's exponential experiments, and the diffusion theory of the reactor (together with others), and derived the formula for the critical size. He studied the processes of neutron multiplication during moderation.
In elementary particle physics, with which he was concerned from its very beginning, he initiated the development of a new field — the physics of extremely high energies. Proceeding from an analysis of dispersion relations, he formulated (1958) a theorem of importance for the theory of strong interactions, according to which at extremely high energies the cross sections for the interaction of a particle and its antiparticle with a nucleon must be equal (the Pomeranchuk theorem). Together with others he extended the theory of the interaction of pions with deuterons, and proved the internal inconsistency of quantum electrodynamics.
He achieved weighty results in solid-state physics as well. Together with L. D. Landau he developed (1937) the theory of the electrical conductivity of metals at low temperatures. He gave a general theory of the inelastic scattering of neutrons in crystals (with A. I. Akhiezer) and constructed a theory of the thermal conductivity of dielectrics at low and high temperatures. In 1950 he predicted the effect in which, at sufficiently low temperatures, the heat of fusion of solid helium 3He becomes negative (the Pomeranchuk effect), and proposed a new method of obtaining low temperatures.
USSR State Prizes (1950, 1952). He founded a school of theoretical physicists.