Role of fission in the r-process nucleosynthesis

Fission can have an important influence on the termination of the r process and on the abundances of long-lived actinides, which are relevant for the determination of the age of the Universe. Fission could also influence the abundances of nuclei in the region A~90 and 130 due to fission cycling. In order to quantitatively understand the fission role in the r process, two important pieces of information are needed: the fission probabilities and massand charge-distributions of the fission fragments. Unfortunately, experimental information is only available for nuclei in a limited region of the nuclide chart, and for heavy r-process nuclei one has to rely on theoretical predictions. This manuscript reviews the status of present experimental and theoretical knowledge on some aspects of fission which are important input for the r-process calculations.