Isai Izrailevich Gurevich (born 13.07.1912) is a Soviet physicist and a corresponding member of the USSR Academy of Sciences (1968). He was born in Riga. He graduated from Leningrad University (1934). In 1934 — 45 he worked at the Radium Institute of the USSR Academy of Sciences. From 1945 he was head of a laboratory at the I. V. Kurchatov Institute of Atomic Energy and from 1946 professor at the Moscow Engineering Physics Institute.
His research concerns nuclear physics, the theory of nuclear reactors and the physics of elementary particles. He put forward the hypothesis of phase transitions of nuclear matter. With M. I. Pevzner he established the repulsion of nuclear levels. Together with others he developed the theory of the nuclear reactor. In 1943, with I. Ya. Pomeranchuk, he carried out a general theoretical treatment of heterogeneous systems with uranium blocks, taking the resonance absorption of neutrons into account. He took part in the development of the first Soviet nuclear reactor. With B. A. Nikolsky he proposed a new method of studying condensed matter, based on the study of the precession and relaxation of the spin of the positive muon. He discovered the two-frequency precession of muonium in a magnetic field.
USSR State Prize (1949). The I. V. Kurchatov Gold Medal (1980).