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 36 nuclear bomb Mark 36 nuclear bomb The Mark 36 was a heavy high-yield United States nuclear bomb designed in the 1950s. It was a thermonuclear bomb, using a multi-stage fusion secondary system to generate yields up to about 10 megatons. The Mark 36 was a more advanced version of the earlier Mark 21 nuclear bomb, which was a weaponized version of the "Shrimp" design, the first "dry" (lithium deuteride) fuel thermonuclear bomb the United States tested, in the Castle Bravo thermonuclear test in 1954. The Mark 21 bomb was developed and deployed immediately after Castle Bravo, in 1955. The Mark 21 design