22Ne(p,γ)23Na cross section measurement at astrophysical energies

A large number of uncertain resonances in the Gamow window make the 22Ne(p, γ)23Na reaction rate the most uncertain in the NeNa cycle. A new direct measurement of the 22Ne(p, γ)23Na reaction has been performed at LUNA (Laboratory for Underground Nuclear Astrophysics), with a windowless gas target. Two complementary setups have been used, to obtain both high resolution and high efficiency measurements. Three new resonances have been discovered at 156.2, 189.5 and 259.7 keV and their decay scheme has been determined. Two tentative resonances at 71 and 105 keV have not been detected and improved upper limits have been put on their strength. Thanks to the high-efficiency setup, it was possible to measure the non-resonant cross section at unprecedented low energies.