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Question about nuclear fusion

  1. Jul 30, 2008 #1
    Hey everyone,

    When you have the fusion of deuterium and tritium, what is it that causes the release of energy? On one website i read that the energy is released according e=mc2 where mass is converted into energy (as the mass of the products<mass of reactants). On another website however, i read that the energy is related to a neutron produced which stores the energy via its velocity. Can someone explain to me which one is correct and how this happens?

  2. jcsd
  3. Jul 30, 2008 #2


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    In the majority of fusion reactions, the nucleons form a more tightly bound nucleus with lower energy, and the excess energy (binding energy) is manifest as the kinetic energy of the products. In the case of d+t, the product is an alpha particle which is very stable, and a free neutron which based on the conservation of energy and momentum takes about 80% of the energy of the reaction.

    Please refer to these:


  4. Jul 30, 2008 #3
    Thanks for the reply astro.
    So basically, the energy from the fusion reaction can be obtained by harnessing the kinetic energy of the neutron?
  5. Jul 30, 2008 #4


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    The kinetic energy of the neutron and alpha particle are the energy released from the reconfiguration of the d,t. The alpha particles is a deeper potential well than the deuteron or triton, and the nuclear potential energy is transformed into the kinetic energies of the alpha particle and neutron. I don't know of an easier way to describe it.
  6. Aug 5, 2008 #5
    Basically, yes. One problem with fusion reactor concepts is that 14 MeV D-T fusion neutrons tend not to stop easily or cleanly, so converting the neutron kinetic energy efficiently into heat without activating everything in sight is difficult.
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