Nuclear fission the Manhattan Project during World War II (September 1, 1939 – September 2, 1945) carried out most of the early scientific work on fission chain reactions, culminating in the three events involving fission bombs that occurred during the war. The first fission bomb, codenamed "The Gadget", was detonated during the Trinity Test in the desert of New Mexico on July 16, 1945. Two other fission bombs, codenamed "Little Boy" and "Fat Man", were used in combat against the Japanese cities of Hiroshima and Nagasaki in on August 6 and 9, 1945 respectively. Even the first fission bombs were thousands of
Mark 11 nuclear bomb nuclear detonation efficiency. Mark 11 nuclear bomb The Mark 11 nuclear bomb was an American nuclear bomb developed from the earlier Mark 8 nuclear bomb in the mid-1950s. Like the Mark 8, the Mark 11 was an earth-penetrating weapon, also known as a nuclear bunker buster bomb. As with the Mark 8, the Mark 11 was a gun-type nuclear bomb (see also Nuclear weapon design#Gun-type assembly weapon). It used a fixed large target assembly of highly enriched uranium or HEU, a gun-like barrel, and a powder charge and uranium bullet or projectile fired up the barrel into the target. The