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HK: Fachverband Physik der Hadronen und Kerne
HK 6: Nuclear Astrophysics I
HK 6.1: Group Report
Monday, March 18, 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 Stöckel1,2, 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).