Particle transport in solar type stars

The potential effects of three particle transport processes on solar evolution are discussed. Even though its effect is not very large, atomic diffusion should in principle be included in the standard solar model. It increases the neutrino flux. Turbulent diffusion could significantly reduce the neutrino flux. No reliable estimate of the strength of turbulence has been made from first principles. Its effect on 3He, Li and Be abundance is discussed. A model with Re*≅50 may reduce sufficiently the neutrino flux while being compatible with the constraints imposed by the abundances and the solar oscillation spectrum. This remains to be shown by detailed calculations