Andrei Sakharov

Andrei Sakharov was a Soviet physicist who played a central role in designing the Soviet Union's first thermonuclear weapon, tested in 1953, and who together with Igor Tamm proposed the tokamak, the doughnut-shaped magnetic confinement concept that remains the leading approach to controlled nuclear fusion power. Sakharov and Tamm put forward the basic tokamak idea in 1950 and 1951 as a way to confine the extremely hot plasma a fusion reaction requires, work later built and refined experimentally at the Kurchatov Institute and eventually adopted by fusion research programs worldwide, including the ITER project. Sakharov later became a prominent Soviet dissident and human rights campaigner, work for which he won the 1975 Nobel Peace Prize, and he expressed regret over the destructive potential of the weapons he had helped build.