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I Why prompt neutron gets less share of energy (fission)

  1. Mar 8, 2017 #1
    why neutron get so little energy in fission reaction as compare to fission fragments?
    according to formula
    Em=Ef(M)/(m+M)
    m=mass of small fragment
    M= mass of relatively big fragment
    Ef=fission energy
    by the same logic neutron should get highest share due to their lower mass. i am missing something please point out. thanks
     
  2. jcsd
  3. Mar 8, 2017 #2

    mfb

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    That formula only works for decays to two particles. Fission splits the nucleus in two (rarely three) parts, those parts then emit neutrons. The decay energies of those processes are a few MeV - the energy of the prompt neutrons (to a good approximation).
     
  4. Mar 8, 2017 #3
    are neutrons emit with fission simulatneously?
     
  5. Mar 8, 2017 #4

    mfb

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    Some are clearly emitted later, for some the question becomes ambiguous - how long do you consider neutrons part of a nucleus, and when exactly is the fission process done? You don't have classical objects moving around.
     
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