People & Events|
The "George" Test
In the summer of 1950, while scientists at Los Alamos were feverishly working on calculations to see if the classical super, the initial design for the hydrogen bomb would work, the weapons laboratory was also preparing for a new series of nuclear tests in the Pacific. Among the devices they were going to detonate was one that would involve thermonuclear reactions (i.e. the fusion of deuterium) and tritium atoms. The test of the device came to be called "George".
"George" was not a design for a hydrogen bomb. But at a time when Los Alamos was totally stymied about how to build such a weapon, "George" was an experiment that would allow scientists to observe a thermonuclear reaction, while showing politicians in Washington that they were making some headway.
The design was similar to ideas for a hydrogen bomb that atomic spy Klaus Fuchs had patented with mathematician John von Neumann in 1946. It placed an atomic bomb inside a heavy shell, close to a capsule of hydrogen fuel. At the moment of detonation--in the fraction of a second before the whole assembly blew itself apart - the shell would confine the radiation from the atomic blast long enough to heat and compress the hydrogen fuel, setting off a fusion reaction. Because "George" used such a large atomic bomb and such a small amount of hydrogen fuel everyone was pretty sure it would work. One scientist compared the design to using a blast furnace to light a match.
Ironically, while the preparations for "George" were underway, mathematician Stanislaw Ulam came up with a breakthrough for an actual hydrogen bomb design. He realized that rather than relying on heat, as the design for the classical super did, to initiate a thermonuclear reaction, the enormous flux of neutrons emitted during the explosion of an atomic bomb could be used to compress the deuterium and tritium causing a fusion reaction. He suggested putting the atomic bomb and hydrogen fuel in a shell which would reflect the neutrons. He also suggested surrounding the hydrogen fuel with material that would effectively magnify the energy of the neutrons.
Since Teller had been working on "George," which used radiation to compress the hydrogen fuel, he realized that the radiation emitted by the atomic bomb would actually work far more effectively in imploding the deuterium tritium mixture. Together Teller and Ulam published their ideas in a report that was released on March 9, 1951. It was their design that led to the creation of the U.S. hydrogen bomb.
The Ulam-Teller breakthrough put the "George" test in a completely new light; it now promised to provide information on radiation implosion. The test took place on May 9 on Eniwetok Atoll in the Marshall Islands of the Pacific. Teller was there to witness it. "We felt the heat of the blast on our faces," he recalled, "but we still did not know if the experiment had been a success. We did not know whether the heavy hydrogen had been ignited."
That afternoon as they waited to hear whether or not the experiment had worked, Teller bet another scientist five dollars that the experiment had been a failure. He lost the bet. Analysis of the explosion showed that the deuterium and tritium, which weighed less than an ounce had yielded the equivalent of about 25 kilotons of TNT, more than twice the force of the Hiroshima bomb.