U.S. detonates Ivy Mike at Enewetak; Elugelab Island is gone
At 7:15 on the morning of November 1, 1952, the United States detonated Ivy Mike on Elugelab Island at Enewetak Atoll, about three years after the Soviet Union's first atomic test (August 1949), and nearly three years after Truman ordered a hydrogen bomb program in January 1950. The device, nicknamed Sausage, stood over 20 feet tall, weighed 82 short tons, and yielded 10.4 megatons of TNT equivalent. Elugelab disappeared, leaving a crater 1.9 kilometers wide and 50 meters deep. It was the first full-yield test of a multi-stage thermonuclear device.
Ivy Mike was the answer to the Soviet bomb of 1949 and the product of a bitter American argument over whether to build it at all. It gave the United States a weapon of megaton scale, and it hung over the 1952 election season, when Oppenheimer's advisers urged delay and the schedule held anyway.
QHow did Edward Teller announce the result without breaking secrecy?
Teller was not at Enewetak. He watched the test succeed through a seismometer in Berkeley, California, which registered the shock from the Pacific. He then sent an unclassified telegram to Dr. Elizabeth "Diz" Graves that read, in full, "It's a boy." The message gave nothing away to anyone who happened to read it, yet it told its recipient what had happened in the Marshall Islands. Teller later included the episode in his memoirs. Having helped design the two-stage concept, he was the physicist most closely tied to the weapon, and he marked its success with a birth announcement.
QWhere did most of Ivy Mike's energy actually come from?
Not from fusion. Of the final 10.4-megaton yield, 77 percent came from fast fission of the uranium tamper, the heavy casing around the device, which the fusion reaction drove to split. The deuterium and the plutonium sparkplug rod sat at the center of the design, but the uranium wrapped around them delivered the bulk of the blast. That is part of why the test was so contaminating: fission products fell as radioactive coral debris on ships 56 kilometers from the shot. The weapon called a hydrogen bomb was, by the numbers, mostly a fission event.
QWhat did the official film of the test sound like?
Nothing like the real thing. The film of the detonation was assembled in post-production, with an explosion sound overdubbed onto the images, Wagner-esque music added beneath them, and narration by the actor Reed Hadley. The result turned footage of a vanished island into something closer to a studio feature. Viewers who saw it got a version of the event shaped by a soundtrack, since the detonation at Enewetak had been photographed from a distance and the audio was supplied afterward.
