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A Maximizing Tritium Breeding

  1. Jul 16, 2016 #1
    Let say we need to maximize the amount of breeded Tritium next to a fusion engine, but we got only access of 4% of the emitted neutrons at 14 MeV. What would be the maximum achievable tritium breeding rate, using Lithium7, Lithium 6, and any neutron Neutron multipliers like lead and beryllium.
    Last edited: Jul 16, 2016
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  3. Jul 21, 2016 #2
    Thanks for the post! This is an automated courtesy bump. Sorry you aren't generating responses at the moment. Do you have any further information, come to any new conclusions or is it possible to reword the post?
  4. Jul 22, 2016 #3
    Well I'm trying to figure out what is the theoretical maximum amount of tritium that can be bred. I heard some figures about close to 2, ITER doesn't seem to be able to get higher than 1.6 using Berylium. Another source entirely I heard the figure 6, but this sounds hard to believe.

    Either Lead or Berelium is used to increase the amount of neutrons, but the resulting neutron are of lower energy, meaning meutron multiplication is very limited.
    Last edited: Jul 22, 2016
  5. Jul 22, 2016 #4


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    That is complicated. You need the cross sections for all relevant processes at all relevant energies, and then some simulation. Neutron multiplication is always limited - otherwise you would have a nuclear weapon. Driving a subcritical fission reactor (multiplication of ~20) with an external neutron source is a concept under study (mainly to burn away transactinides), but that is not a fusion reactor any more. Combined fusion/fission reactors are also a concept, but then you have the radioactive waste issue again.
  6. Jul 22, 2016 #5
  7. Jul 23, 2016 #6


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    what is that figure?
  8. Jul 23, 2016 #7


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    I believe Sebastiaan is referring to a breeding ratio, i.e., for one T consumed, one would obtain 6 T, ostensibly from some spallation reactions with neutrons of an initial energy of 14 MeV. There are a number of (n, 2n) reactions and possibly (n,3n) reactions, but they have high energy thresholds. Then each neutron has to be absorbed in something that produces an (n, t) reaction. Alternatively, if one can use some (n, n't) or (n, n'nt) reactions, it might be feasible, but that might require an exotic blanket.

    Also, one has to keep in mind the level of consumption. How much of a blanket will be consumed to produce X kg (or moles) of T.
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