F.-K. Thielemann
Department of Physics and Astronomy, University of Basel, Klingelbergstrasse 82, CH-4056 Basel, Switzerland
Nuclei far from Stability: Their Role and Production in Astrophysical Events

Astrophysical explosions can provide thermodynamic conditions which lead to the production of nuclei far from stability. In combination with the environment properties (like the global neutron/proton ratio) this can favor nuclei near the proton drip-line (the rp-process, rapid proton capture), moderately proton-rich nuclei (the p- or gamma-process), or very neutron-rich nuclei up to the neutron drip-line (the r-process, rapid neutron capture).

For the astrophysical events involved (e.g. novae, X-ray bursts, supernovae, neutron star mergers, probably gamma-ray bursts) highly unstable nuclei can either be of significant importance to explain the explosion energetics (e.g. in the rp-process in X-ray bursts), or in the other extreme they might just serve as a means to produce an abundance pattern found in nature (e.g. in the p- or gamma-process in supernovae). In case of the r-process this question can only be answered once its astrophysical site is unambiguously determined.

In addition, varying amounts of nuclear physics input are needed. In some cases experimental cross section determinations are required to model an astrophysical site adequately, in other cases gross properties like masses or decay half-lives might be sufficient if chemical equilibria are obtained. In again different cases there is no chance to perform cross section measurements but nuclear properties can be determined to aid theoretical cross section predictions.

I intend to provide an overview of the astrophysical sites involved and the related nuclear physics needs which could be addressed in Rare Isotope Accelerators.