Consistent solar evolution model including diffusion and radiative acceleration effects

The solar evolution has been calculated including all the effects of the di ffusion of helium and heavy elements. Monochromatic opacities are used to c alculate radiative accelerations and Rosseland opacities at each evolution time step, taking into account the local abundance changes of all important (21) chemical elements. The OPAL monochromatic data are used for the opaci ties and the radiative accelerations. The Opacity Project data are needed t o calculate how chemical species and electrons share the momentum absorbed from the radiation flux. A detailed evaluation of the impact of atomic diffusion on solar models is presented. On some elements thermal diffusion adds approximately 50% to the gravitational settling velocity. While gravitational settling had been inc luded in previous solar models, this is the first time that the impact of r adiative accelerations is considered. Radiative accelerations can be up to 40% of gravity below the solar convection zone and thus affect chemical ele ment diffusion significantly, contrary to current belief. Up to the solar age, the abundances of most metals change by 7.5% if comple te ionization is assumed, but by 8.5%-10% if detailed ionization of each sp ecies is taken into account. If radiative accelerations are included, inter mediate values are obtained. Diffusion leads to a change of up to 8% in the Rosseland opacities, compared to those of the original mixture. Most of th is effect can be taken into account by using tables with several values of Z. If one isolates the effects of radiative accelerations, the abundance chang es they cause alter the Rosseland opacity by up to 0.5%; the density is aff ected by up to 0.2%; the sound speed is affected by at most 0.06%. The incl usion of radiative accelerations leads to a reduction of 3% of neutrino flu xes measured with Cl-37 detectors and 1% measured with Ga-71 detectors. The partial transformation of C and O into N by nuclear reactions in the co re causes a similar to 1% change in the opacities that cannot be modeled by a change in Z alone. The evolution is allowed to proceed to 10(10) yr in order to determine the impact at the end of the main-sequence life of solar-type stars. It is foun d that immediately below the convection zone, the radiative acceleration on some iron peak elements is within a few percent of gravity. The abundance anomalies reach 18% for He in the convection zone but are kept within 12% a nd 15% for most because of g(rad). They would have reached 18% in the absen ce of g(rad).