I know that D+D (fusion of deuterium + deuterium nuclei) as well as D+T (fusion of deuterium and tritium nuclei) are the reactions most commonly considered for large-scale power production. Why not D+P (fusion of deuterium and hydrogen/proton nuclei)?

  • 1
    $\begingroup$ Welcome to PhysicsSE! For the sake of readability, it might be helpful to specify that P, D, and T stand for protium (or proton), deuterium, and tritium, respectively. $\endgroup$ – Chris May 29 '19 at 23:12
  • 4
    $\begingroup$ Have you checked the cross sections? D(p,g)3He has a cross section that peaks at about 10 microbarns (at nearly 10MeV). D-D is about 0.2 barns at 1MeV, and D-T is 5 barns at 0.1MeV. Which is easier? $\endgroup$ – Jon Custer May 29 '19 at 23:34
  • $\begingroup$ Also, D+P emits a gamma photon, which isn't easy to extract useful energy from. See en.wikipedia.org/wiki/… Also see hyperphysics.phy-astr.gsu.edu/hbase/NucEne/fusion.html $\endgroup$ – PM 2Ring May 29 '19 at 23:58
  • $\begingroup$ Thanks for the advice. I've made the recommended changes to the question. The differences in cross sections and reaction products are good answers. $\endgroup$ – MrFu May 30 '19 at 15:27
  • 1
    $\begingroup$ @probably_someone Very true, and they both have an annoying tendency to make the matter in the vicinity radioactive. That's why I like proton + boron fusion, it's aneutronic (apart from pesky side reactions), and the energy is in the KE of alpha particles, which can be braked electromagnetically. It's a shame that the activation energy is so high. $\endgroup$ – PM 2Ring May 30 '19 at 16:44

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Browse other questions tagged or ask your own question.