München 2019 – wissenschaftliches Programm

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HK: Fachverband Physik der Hadronen und Kerne

HK 6: Nuclear Astrophysics I

HK 6.1: Gruppenbericht

Montag, 18. März 2019, 14:00–14:30, HS 16

Recent progress at the LUNA deep underground accelerator: The ²²Ne(p,γ)²³Na, ²²Ne(α,γ)²⁶Mg, and ²H(p,γ)³He reactions — •Daniel Bemmerer¹, Klaus Stöckel^1,2, and Tamás Szücs¹ for the LUNA collaboration — ¹Helmholtz-Zentrum Dresden-Rossendorf (HZDR), Dresden, Germany — ²TU Dresden, Germany

New data from the LUNA 0.4 MV accelerator in Italy’s Gran Sasso lab will be reviewed. After the discovery of three new ²²Ne(p,γ)²³Na resonances, very recently the study of this nuclear reaction has been completed with stringent upper limits on two hypothetical resonances at ultra-low energy (Phys. Rev. Lett. 121, 172701 (2018)). A key uncertainty has been removed from the so-called hot-bottom burning process in asymptotic giant branch stars, enabling studies of the anticorrelated Na and O abundances in globular cluster stars. – The ²²Ne(α,γ)²⁶Mg reaction competes against one of the main neutron source reactions of the astrophysical s-process. One of several poorly known resonances is in the LUNA 0.4 MV energy range and under study there. – Measurements of the primordial ²H abundance have rekindled hope to decisively improve the precision of Big Bang nucleosynthesis constraints on the primordial baryon to photon ratio. However, the interpretation of the ²H abundance data is limited by the imprecise knowledge on ²H destruction by the ²H(p,γ)³He reaction. A study of this reaction directly in the Big Bang energy window is underway at LUNA. – Finally, an update will be given on the progress of the construction of the new, 3.5 MV underground ion accelerator LUNA-MV in Gran Sasso hall B. – Supported by DFG (BE 4100/4-1).