Igor Kurchatov (1903-1960)
Igor Kurchatov was born in a town in the southern Urals, and educated in Crimean University. He joined the famous physicist Abram Ioffe's Institute in Leningrad in 1925. Ioffe nominated Kurchatov as the leader of nuclear physics, at the age of 29; and Kurchatov organized the construction of a small cyclotron, the first one in Europe.
However, a great turning point came in 1943, when he was appointed scientific director of the Soviet nuclear project. His initial plan was (1) constructing a test reactor and (2) making the fission bomb. However, the Soviet economy was in a horrible state and the country was under attack of Germany. Thus the early research heavily depended on information provided by espionage. Surprizingly, Kurchatov and his boss Beria obtained all the essential information of the Americal plutonium bomb ("Fatman" that destroyed Nagasaki) by the end of June 1945. But the Soviet Union had no atomic industry so that Kurchatov and his team had to construct that industry from the naught. Kurchatov directly appealed to Stalin that his team was provided with little support from the nation, but Stalin neglected. However, informed of the Hiroshima explosion, Stalin became furious, and the Soviet bomb project immediately restarted, this time with full support by Stalin.
The Soviet first bomb, called by Americans "Joe 1", was an exact copy of Fatman, and its experiment at a Semiparatinsk site was successful, on August 29, 1949. By this time, the Soviet team already had a promising idea of "Layer Cake" proposed by A. Sakharov; that was a device using both fission and fusion processes initiated by high explosives. Thus after the success of Joe 1, the development of Layer Cake became the top priority, and its experiment (Joe 4) succeeded on August 12, 1953. With this, the Soviet Union seemed to catch up with the US which already had a superbomb (multi-stage ignition of fusion fuel, by means of X-rays obtained from the primary fission device; this configuration is called Teller-Ulam invention); but the US Mike shot yielded 10 megatons in 1952, a far greater power than Layer Cake which yielded 0.4 megaton.
The Soviet team finally came to the same ideas in the spring of 1954, and the Soviet first superbomb succeeded in November 1955. Unlike the US Mike, it was a rather small device deliverable by airplane. Because of the test conditions, its fusion fuel was reduced to a half; but it yielded 1.6 megatons and unexpected casualties. This was another turning point for Kurchatov. Seeing the ground zero, Kurchatov was shocked: a huge crater was produced on the site, and he thought that this weapon should never be used. He decided to retire from any further test.
Around this time, he directed his attention to peaceful uses of nuclear powers. He helped preparations for international conferences where the Soviet physicists met Western scholars after 20 years of break. And Kurchatov himself visited Britain in 1956, and delivered a lecture on the Soviet new research on controlled fusion, breaking the spell of secrecy prevailed on both sides, East and West. He died suddenly in 1960, in the midst of conversation with Iulii Khariton, a longtime colleague. His name is commemorated by the Kurchatov Institute in Moscow, where he constructed the first test reactor F-1.
Last modified Dec. 9, 2008. (c) Soshichi Uchii