Low-energy cross section measurements of the Ne-22(p,gamma)Na-23 reaction [Low-energy cross section measurements of the ${}^{22}Ne^{23}Na$ reaction]

Because of a large number of uncertain resonances in the Gamow window, the Ne-22(p,gamma)Na-23 reaction rate was the most uncertain in the NeNa cycle. Recently, a new direct study of the Ne-22(p,gamma)Na-23 reaction has been performed at the Laboratory for Underground Nuclear Astrophysics (LUNA). A windowless gas target and two complementary setups have been used, to obtain both high resolution and high efficiency measurements. The new resonances at 156.2, 189.5 and 259.7 keV have been discovered and their decay scheme has been determined. The tentative resonances at 71 and 105 keV have not been observed and improved upper limits have been put on their strength. Moreover, the high-efficiency setup allowed the measurement of the non-resonant cross section at unprecedentedly low energies. The thermonuclear reaction rate based on the new measurements has been evaluated.