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
Hiroshima National Peace Memorial Hall for the Atomic Bomb Victims stories from the survivors to mourn the victims, as the survivors are aging. They are also collecting names and photographs of atomic bomb victims for the same purpose and for the same reason. From the collection, they are developing a project to "read the stories of the atomic bombing". Admission is free of charge. Hiroshima National Peace Memorial Hall for the Atomic Bomb Victims Hiroshima National Peace Memorial Hall for the Atomic Bomb Victims is one of the National Memorial Halls in Hiroshima, Japan. The Hall was founded by the Japanese national government to mourn the atomic bomb victims in