Mixing and nucleosynthesis in rotating TP-AGB stars

We present the first evolutionary models of intermediate mass stars up to t heir thermal pulses which include effects of rotation on the stellar struct ure as well as rotationally induced mixing of chemical species and angular momentum. We find a significant angular momentum transport from the core to the hydrogen-rich envelope and obtain a white dwarf rotation rate comparab le to current observational upper limits of less than or similar to 50 km s (-1). Large angular momentum gradients at the bottom of the convective envelope a nd the tip of the pulse driven convective shell are shown to produce marked chemical mixing between the proton-rich and the C-12-rich layers during th e so called third dredge-up. This leads to a subsequent production of C-13 which is followed by neutron production through C-13(alpha, n) in radiative layers in between thermal pulses. Although uncertainties in the efficiency of rotational mixing processes persist, we conclude that rotation is capab le of producing a C-13-rich layer as required for the occurrence of the s-p rocess in TP-AGB stars.