Mainz 2012 – wissenschaftliches Programm

Bereiche | Tage | Auswahl | Suche | Aktualisierungen | Downloads | Hilfe

HK: Fachverband Physik der Hadronen und Kerne

HK 31: Nukleare Astrophysik

HK 31.1: Gruppenbericht

Mittwoch, 21. März 2012, 16:30–17:00, RW 2

Investigation of decays of r-process nuclei — •Michele Marta^1,2, Iris Dillmann^1,2, and Alexey Evdokimov^1,2 — ¹GSI Helmholtzzentrum für Schwerionenforschung GmbH, Darmstadt, Germany — ²II. Physikalisches Institut, Justus-Liebig Universität Giessen, Germany

The r-process nucleosynthesis accounts for about half of the solar abundances beyond the iron peak. A complete understanding of the process is complicated by the scarce experimental information of the many short-lived neutron-rich nuclei of interest along the r-process path. Particularly, non-zero β-delayed neutron branchings divert the material flow back to stability during the freeze-out phase and provide additional neutrons which can be recaptured. A recent experimental campaign at the fragment separator FRS facility at GSI has investigated decay half-lives and following neutron emission of unstable nuclei close to the neutron shell closure N = 82 and N = 126. The fragments produced by a 1 A·GeV primary beam of uranium on a ⁹Be target have been separated in-flight, identified, and implanted in a segmented Si array detector. Thirty ³He counters in a polyethylene matrix surrounded the implantation station and detected the delayed neutrons in coincidence with β-decays in the Si detector. The status of the ongoing analysis and an outlook are presented.