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I've been reading about fusion fuels for a while now, and I understand that in Lithium-Deuterium fuel, the neutrons from the fission reaction bombard the Lithium to produce Tritium and the D-T reaction occurs and we get the energy.

So what about Deuterium-Deuterium fusion ? Is it possible without the presence of Tritium at all ? If so, then does it release more or less energy than D-T fusion ?

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    $\begingroup$ I was reading Wikipedia's article on free neutrons which contains this: "D-D fusion produces a 2.45 MeV neutron and helium-3 half of the time, and produces tritium and a proton but no neutron the other half of the time." So yes, it is possible. $\endgroup$ – Hennes Aug 24 '13 at 22:54
  • $\begingroup$ As asked the answer to the questions if effectively certain to be "yes", simply because an alpha particle is more stable than a pair of deuterons, but that answer would also be useless because it doesn't tell you anything about the preconditions or the rates relative other processes. You seem to be hoping that a few open ended questions will substitute for a lot of hard work in familiarizing yourself with a big and complicated subfield of physics, and I would suggest that the small number of answer you are getting represents a critique of the style of questions you've been asking. $\endgroup$ – dmckee --- ex-moderator kitten Aug 24 '13 at 23:22
  • $\begingroup$ A D-D reaction is harder to initiate than a D-T reaction, which is why D-T fusion is used. $\endgroup$ – DOS4004 Jul 25 '15 at 18:14
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All three isotopes of Hydrogen can undergo fusion under the right conditions. The main reason to use D or T is that they fuse more easily than H. For example, H-H fusion is primarily what drives our sun, but in the lab D-D or D-T reactions are much easier to initiate.

The D-T reaction gives off 17.6 MeV of energy, D-D actually has 3 different reactions it can undergo (4, 3.3, 23.9 MeV), T-T gives 11.33 Mev, D-H gives off 5.5 MeV and H-H fuses into D giving off 1.44 MeV.

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Deuterium-Deuterium fusion without Tritium is very possible.

Historically, D-D fusion was the first form of nuclear fusion mankind successfully achieved.

It may be worthwhile remembering that, at the dawn of the nuclear age in 1952, an inertial confinement fusion experiment that used nuclear fission to produce the conditions for nuclear fusion called Ivy Mike not only produced net energy (more energy out of the fusion experiment than the energy required to operate the fusion experiment) but achieved a fusion gain factor of Q>=100,000.

Ivy Mike achieved net energy and Q>=100,000 using the D-D fusion reaction.

Note: No other non-military pure fusion experiment in the world has achieved a fusion gain factor Q>1 at any time, even for milliseconds, in the last 60 years. (Picture of Ivy Mike D-D fusion experiment - 1952)http://www.sonicbomb.com/content/atomic/carc/us/ivy/limg/mikedevice.jpg

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  • $\begingroup$ also note that there will inevitably be some D-D reactions in a primarily D-T fusion $\endgroup$ – DOS4004 Mar 18 '15 at 4:43

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