Ivy Mike was the codename for the first full-yield test of a multi-stage thermonuclear device, utilizing the innovative Teller–Ulam design. Conducted by the United States on November 1, 1952, the detonation took place on the island of Elugelab within the Enewetak Atoll as a significant component of Operation Ivy.
With a yield of 10.4 megatons of TNT, the test far exceeded the power of the previous record-holder, Greenhouse George. This event remains the fourth most powerful nuclear test ever conducted by the United States and ranks as the tenth most powerful globally. The success of Ivy Mike served as a pivotal moment in the Cold War nuclear arms race between the United States and the Soviet Union.