Thin Man (nuclear bomb) Thin Man (nuclear bomb) "Thin Man" was the code name for a proposed plutonium gun-type nuclear bomb using plutonium-239 which the United States was developing during the Manhattan Project. They aborted its development when they discovered that the spontaneous fission rate of their nuclear reactor-bred plutonium was too high for use in a gun-type design, due to the high concentration of the isotope plutonium-240. In 1942, prior to the Army taking over wartime atomic research, Robert Oppenheimer held conferences in Chicago in June and Berkeley, California, in July at which various engineers and physicists discussed nuclear bomb design issues. A
Igor Kurchatov the USSR and the Silver Medal of the World the Joliot-Curie. In the Transfermium Wars element naming controversy, the USSR's proposed name for element 104 was "kurchatovium", Ku, in honor of Kurchatov. Element 104 is now known as rutherfordium. Igor Kurchatov Igor Vasilyevich Kurchatov (; 8(21) January 1903 – 7 February 1960), was a Soviet nuclear physicist who is widely known as the director of the Soviet atomic bomb project. Along with Georgy Flyorov and Andrei Sakharov, Kurchatov is known as the "father of the Soviet atomic bomb" and, later, "the father of the Soviet Nuclear Missile" for his directorial