AGB stars are the source for the main component of the s-process. Here we
discuss both the properties which are reasonably well known and those which
still suffer from substantial uncertainties. In the former case, we are fairly
sure that the s-process contribution from AGB stars comes from masses between
about 1 and 3 \msun, and the dominant neutron source is the
13C(α,n)16O reaction. In the latter category remains the
formation mechanism for the 13C-pocket. Attempts at including rotation
seem to inhibit neutron capture reactions. Explaining the observations seems to
require a spread in the size of the 13C-pocket so some stochastic process,
such as rotation, must be involved.Comment: To be published in Nuclear Physics A; Invited Review for "Nuclei in
the Cosmos VIII", Vancouver, July 200