Word: fissionability
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...sensitive dating method-the measurement of alpha-particle tracks. Uranium nuclei frequently emit an alpha particle. As the particle is expelled, the nucleus recoils. Walker reasoned that "recoil tracks would be there, so I looked for them." He discovered that observable recoil tracks occurred 4,000 times more than fission tracks. When acid etching and track counting are perfected for alpha particles, the method should provide a means of dating infinitesimally small objects and those too young to have accumulated measurable amounts of fission tracks...
Dating the Moon. Walker's methods have already produced important discoveries. By analyzing fission tracks, Russian scientists recently identified the 104th chemical element, named Khurchatorium, arid U.S. research scientists spotted the phenomenon of triple fission-the splitting of a nucleus into three roughly equal parts. General Electric scientists have irradiated thin strips of plastic, etched the fission tracks with acid, and produced a material of great potential medical significance-a sensitive sieve that duplicates the filtering capacity of human membranes...
...uranium in the fallout of China's third and fifth A-bomb explosions-clues that it was developing nuclear triggers to set off hydrogen warheads. U.S. experts guessed that last week's bomb, which was detonated in the air over the Sinkiang desert, was probably a standard fission-fusion-fission device in the "several megaton" range...
...Slow Fission. Even if the shock wave fails to set off the warhead's conventional explosive, it can damage electronic components or cause sufficient changes in the critical shape of internal cavities within the warhead to prevent a nuclear explosion. In addition, the heating of the ICBM's exterior may so damage its heat shield that the missile would burn up upon entering the atmosphere...
Neutrons produced by the ABM blast could also cause crippling damage at a range of about two miles. Penetrating into the ICBM's outer shell of uranium 238, they can produce slow fission, causing heat that may deform the warhead or set off its lens charges. The neutrons may also whiz into the warhead's core of uranium 235, causing it to explode in a premature nuclear blast while still hundreds of miles from its target...