M. WIESCHER

The observation of oxygen isotopes in giant stars sheds light on mixing processes operating in their interiors. Due to the very strong correlation between nuclear burning and mixing processes it is very important to reduce the uncertainty on the cross sections of the nuclear reactions that are involved. In this paper we focus our attention on...

Direct measurements of small nuclear reaction cross sections require a low background in the signal region of interest to achieve the necessary sensitivity. We describe two complementary detector setups that have been used for studies of (p, gamma) reactions with solid targets at the Laboratory for Underground Nuclear Astrophysics (LUNA): a...

Background: Shell hydrogen burning during the asymptotic giant branch (AGB) phase through the oxygen isotopes has been indicated as a key process that is needed to understand the observed 18O/16O relative abundance in presolar grains and in stellar atmospheres. This ratio is strongly influenced by the relative strengths of the reactions...

The NeNa and the MgAl cycles play a fundamental role in the nucleosynthesis of asymptotic giant branch stars undergoing hot bottom burning. The 23Na(p, γ)24Mgreaction links these two cycles and a precise determination of its rate is required to correctly estimate the contribution of these stars to the chemical evolution of various isotopes of...