Study of the ²⁰Ne(p,γ)²¹Na reaction at LUNA

The 20Ne(p,γ)21Na is the first reaction of the NeNa cycle and having the slowest reaction rate, it controls the speed at which the entire cycle proceeds. This reaction is important in different stellar scenarios such as red giants stars (during H shell-burning), asymptotic giant branch stars, novae, and massive stars. Existing uncertainties on the 20Ne(p,γ)21Na are now the ones that severely affect the estimated elements production in the NeNa cycle. In particular, such uncertainties affect the amount of produced 22Na, a stellar γ-ray signature, and 22Ne, an important neutron source in the s-process, via the 22Ne(α,n)25Mg. Here, we propose to study the resonance at ER = 366 keV and to measure the 20Ne(p,γ)21Na reaction cross section at proton energies below 400 keV, in particular the contribution from the sub-threshold state, in order to better constrain the overall astrophysical rate of this important reaction. In this contribution, the experimental setup will be described and the expected results discussed.