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Fission: how far from the center of a U-235 nucleus can a neutron strike

  1. May 5, 2012 #1
    and successfully fission. let's say a neutron approaches the spherical nucleus from a particular distance. its possible route to the nucleus has a conical shape. how far from the center can it strike and still fission? If it just nicks it just inside a tangent line will it fission?
  2. jcsd
  3. May 5, 2012 #2


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    It's not quite that simple. The property of interest here is the cross section of fission for the nucleus, and that depends on more than 1 factor.

    For example, the the cross-sectional area of a U235 nucleus is about 1 barn. However, for slow moving neutrons, the cross section for fission can be as large as 1000 barns.
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