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
Mark 10 nuclear bomb a Nuclear bunker buster. The Mark 10 was nicknamed the "Airburst Elsie"; the Mark 8 had been nicknamed the LC or Light Casing bomb, which was then expanded to "Elsie". The Mark 10 was 12 inches in diameter and weighed 1,500 or 1,750 pounds. It had a design yield of 12 to 15 kilotons. The Mark 10 design was cancelled in 1952, replaced by the implosion-type Mark 12 nuclear bomb which was lighter and used considerably less fissile nuclear material. Mark 10 nuclear bomb The Mark 10 nuclear bomb was a proposed American nuclear bomb based on the earlier Mark