Free Sun in a Bottle by Charles Seife Page B

The compressing plasma soon ignites a small “spark plug ” of fissionable material at the center of the cylinder, generating a second fission explosion that squeezes the fuel from the inside. The deuterium and tritium are caught between a pusher that is pushing inward and the spark plug explosion pushing outward. The fuel compresses even further and, whoomp! The fusion reaction ignites. It’s as if there’s a tiny hunk of the sun on Earth.

    DETONATION OF A HYDROGEN BOMB: (a) A fission bomb explodes at one end of the device, sending x-rays in all directions. (b) The x-rays strike the walls of the container, causing them to evaporate and radiate more x-rays. These x-rays hit the container containing deuterium and tritium, causing it to implode. (c) The compressing deuterium and tritium fuel heats up and ignites a fission “spark plug” at the center of the device, causing it to explode outward. Trapped between the imploding container and the exploding spark plug, the fuel ignites in a fusion reaction.
    The reaction only lasts for a fraction of a second before it blows itself apart, but in the process it releases an enormous amount of energy. Ivy Mike was equivalent to ten megatons of TNT, but there was no reason why the whole device could not have been scaled up by adding a third stage . . . or a fourth. In 1961, the Russians detonated a (roughly) fifty-megaton whopper nicknamed the Tsar Bomba, the most powerful weapon ever built by man.
    In theory, there was no end to the power of fusion. But the race to build ever-bigger hydrogen bombs crept to a halt, because it had diminishing returns. As early as 1949, scientists realized that after about 150 megatons, hydrogen bombs simply take a huge column of air and lift it into outer space, punching a hole in the atmosphere about fourteen miles across. Bigger bombs would not do much more than that. They would radiate most of their energy uselessly into space. So after 150 megatons, there was no point in getting bigger, unless you wanted to build a fusion device large enough to destroy the Earth. Not even the most rabid hawks were in favor of that.
    Nevertheless, with Ivy Mike and its successors, the fusion bomb scientists had succeeded at creating a tiny star on Earth. For a fraction of a second, scientists were able to get a fusion reaction going. They had figured out how to use that energy for war. It would be much, much harder to harness that energy for peace.

CHAPTER 3
    PROJECT PLOWSHARE AND THE SUNSHINE UNITS
    I’ve felt it myself, the glitter of nuclear weapons. It is irresistible if you come to them as a scientist. To feel it’s there in your hands to release this energy that fuels the stars. To let it do your bidding. To perform these miracles, to lift a million tons of rock into the sky. It is something that gives people an illusion of illimitable power and it is in some ways responsible for all our troubles—I would say, this, what you might call “technical arrogance” that overcomes people when they see what they can do with their minds.
     
—FREEMAN DYSON, IN THE DAY AFTER TRINITY
     
     
    O n January 15, 1965, deep inside the Soviet Union, a nuclear rumble shook the earth. The Americans were the first to spot the radioactive cloud as it floated over Japan and toward the Pacific Ocean beyond. The Soviets had detonated a fusion bomb, and the fallout was contaminating the atmosphere over the Japanese mainland. This particular explosion was different from all the other bombs exploded over two decades of nuclear testing. This one had the makings of a major diplomatic incident.
    A little more than a year earlier, the United States and the Soviet Union had signed an international agreement to limit the scope of nuclear testing. No longer was it acceptable to detonate a nuclear bomb on the surface of the Earth, in the atmosphere, underwater, or in space. Only underground testing was allowed. Even an underground test was a violation if it caused radioactive debris