by F. Herwig, B. Freytag, R. M. Hueckstaedt and F. Timmes
The Asymptotic Giant Branch (AGB) phase is the most productive evolutionary
phase in terms of nucleosynthesis for low and intermediate mass
stars. Nucleosynthesis in these stars is intimately linked to the mixing
and heating triggered by recurrent He-shell flashes. We report on 2- and
3-dimensional hydrodynamic simulations of convective mixing in AGB He-shell
flashes. We find, for example, that convective motions induce a rich
spectrum of internal gravity waves in the neighboring stable layers, and
that a finite and quantifyable amount of mixing across the convective
boundary (similar to overshooting) takes place.