Glossary
The PP chains

While on the Main Sequence the primary nuclear reactions within the core of Sun involve the conversion of hydrogen (1H) to Helium (4He) via the so-called "proton-proton" (or simply PP) chains or via the CNO Cycle.

The PP Chains are:

  • (69% probable) "PP I" chain
    1H + 1H converted to 2H + e+ + nue
    Note added 2002 Mar 10:
    prior to this date the above product was erroneously given as 1H
    (Sorry for any confusion this might have caused)
    2H + 1H converted to 3He + photon
    3He + 3He converted to 4He + 2 1H

  • (30.7% probable) "PP II" chain
    3He + 4He converted to 7Be + photon
    7Be + e- converted to 7Li + nue
    Note added 2002 Mar 10:
    prior to this date the above product was erroneously given as 7He
    (Sorry for any confusion this might have caused)
    7Li + 1H converted to 2 4He

  • (0.3% probable) "PP III" chain
    3He + 4He converted to 7Be + photon
    7Be + 1H converted to 8B + photon
    8B converted to 8Be + e- + nue
    8Be converted to 2 4He

(where e+ is a positron and nue is an electron-neutrino).