Word: fissioned
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Dates: during 1950-1959
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This was an exciting and ominous prospect, but the trouble with fusion reactions is that they are not self-starting; uranium fission is. When a sufficient amount (critical mass) of U-235 is assembled, a single, slow-moving neutron can start an atom-splitting chain reaction in it and make the whole chunck explode. Light elements are not so accommodating. Their atoms must be slammed together violently to make them group into larger atoms and yield energy...
Ordinary-high temperatures, attainable by chemical means, are not nearly high enough, but the center of an exploding uranium-fission bomb (more than 50,000,000° C.) is as hot or hotter than the interior of the sun. Before the first atom bomb exploded, physicists were speculating as to whether atom bombs might serve as "detonators" to start fusion explosions...
...hard to come by. Pessimists feared that too much tritium would be required. They pointed out that each atom of tritium manufactured in a nuclear reactor costs about one atom of U-235 or plutonium, which could be used to better advantage, they thought, in old-style fission bombs...
...both behaved about the same. Now the situation is more complicated. Many light isotopes are suitable for fusion, and under the conditions in an exploding bomb, they may react with one another in many different ways. They also react with the products, e.g., neutrons, given off by the fission detonator, and with materials in the casing of the bomb. As the temperature changes, their behavior changes too. So a diagram describing the behavior of a fusion bomb can give only a few of the possible ingredients and tell only a few of the ways in which they may react...
...main trends of H-bomb development, however, are clear to all. An early step was to force the temperature of the fission detonator (atom bomb) as high as possible. One way to do this is to make the fission reaction more efficient. The early bombs "burned" only a fraction of their fissionable material. As they were improved, they burned more of it and reached higher temperatures. The improved bombs, even though not designed with hydrogen bombs in mind, were therefore more effective as detonators...