# Can we produce tritium from helium 3? If yes how?

I want to know the best and economic way of the manufacture of tritium from helium-3

• I don't think this can be done – Waylander Feb 23 '18 at 11:56
• Then again, this might be a worldbuilding question (helium-3 and tritium are both used a lot in science fiction). However, at least for now it seems to ask a legitimate chemistry question. – JSCoder says Reinstate Monica Feb 23 '18 at 13:10

The He3(n,p)T reaction has a cross section in excess of $10^{5}$ barns at low (thermal) neutron energies.
The Li6(n,T)He4 reaction mentioned in another answer has a smaller cross section, in excess of $10^{4}$ barns at low neutron energies, so it is about 10x less efficient to make tritium this way (not even counting enriching to get Li6 instead of Li7).