proton-proton chain |
A series of nuclear reactions, believed to occur in stars, which convert hydrogen to helium and provide a major stellar energy source. The main process consists of the following stages: 1H + 1H -> 2H + positron + neutrino 2H + 1H -> 3He + gamma-ray photon 3He + 3He -> 4He + 1H + 1H. |