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Andrei Sakharov

The Soviet nuclear physicist who co-invented the tokamak concept with Igor Tamm in 1950 — and later became the world’s most famous dissident, winning the 1975 Nobel Peace Prize.

Reviewed Last reviewed: 9 Aug 2026 · Category: Scientists & Pioneers

Early Life and Education

Andrei Dmitrievich Sakharov (21 May 1921 – 14 December 1989) was born in Moscow. He studied physics at Moscow State University (graduating 1942) and completed his doctorate at the P.N. Lebedev Physical Institute under Igor Tamm in 1947.[1]

The Tokamak Concept

In October 1950, while working at the secret Arzamas-16 weapons laboratory, Sakharov and Tamm proposed confining high-temperature plasma in a toroidal magnetic chamber with strong magnetic coils — the concept later named the tokamak. Sakharov calculated provisional parameters for a D–D reactor: major radius 12 m, minor radius 2 m, magnetic field 5 T, and power capacity 900 MW.[2]

Declassification: The Sakharov–Tamm tokamak papers were classified until 1956, when Igor Kurchatov presented the work at Harwell, UK. They were published in Leontovich’s multi-volume Plasma Physics and the Problem of Controlled Thermonuclear Reactions (Pergamon, 1961).

Hydrogen Bomb

Sakharov was the principal designer of the Soviet hydrogen bomb, first tested in 1953. He was elected a full member of the Soviet Academy of Sciences at age 32 — one of the youngest ever. The “Tsar Bomba” design (1961, ~50 MT) also bears his imprint.[3]

Human Rights and Nobel Peace Prize

From the late 1950s, Sakharov publicly opposed nuclear testing. His 1968 essay Reflections on Progress, Peaceful Coexistence, and Intellectual Freedom circulated widely. He received the 1975 Nobel Peace Prize but was barred from traveling to Oslo; his wife Yelena Bonner accepted on his behalf. In 1980 he was exiled to Gorky; Gorbachev ended the exile in December 1986.[4]

Legacy

The tokamak Sakharov co-invented is now the most experimentally advanced fusion concept. ITER, the world’s largest tokamak, is a direct descendant of his 1950 proposal.[5]

Sources

  1. Sakharov, A.D. Memoirs. Trans. Richard Lourie. Alfred A. Knopf, 1990.
  2. Sakharov, A.D. and Tamm, I.E. In Plasma Physics and the Problem of Controlled Thermonuclear Reactions, Vol. 1, ed. M.A. Leontovich. Pergamon Press, 1961.
  3. Smirnov, V.P. "Tokamak foundation in USSR/Russia 1950–1990." Nuclear Fusion, 50, 014003, 2010.
  4. Nobel Prize Committee. "The Nobel Peace Prize 1975 — Andrei Sakharov." NobelPrize.org.
  5. Lourie, R. Sakharov: A Biography. Brandeis University Press, 2002.

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