People of the Revolution and the USSR

Soviet Union Soviet communism 1895–1971 ○ ALS

From the H-bomb to the tokamak: theoretical physicist of two nuclear ages

After the first successful H-bomb test in 1953, Tamm left weapons work and returned to Moscow, devoting his remaining eighteen years to the peaceful use of fusion.

Igor Tamm was a Soviet theoretical physicist who, with Ilya Frank, explained Cherenkov radiation, earning the 1958 Nobel Prize in Physics. From 1934 until his death he headed theoretical physics at FIAN, the center of Soviet theory; his contributions include Tamm surface states, predicting the neutron's magnetic moment, and the Tamm-Dancoff approximation. Recruited by Igor Kurchatov in 1948, he led the H-bomb theory group at Arzamas-16 (1949–1953), whose Sloika design succeeded in the first Soviet thermonuclear test, August 1953. In 1951, with Andrei Sakharov, Tamm proposed the tokamak (toroidal magnetic plasma confinement), now the basis for all major fusion reactor designs. In his later years he signed the Letter of the Three Hundred against Lysenkoism (1955) and the letter of 25 opposing Stalin's rehabilitation (1966).