A new study of the ${}^{22}$Ne(p,$\gamma$)${}^{23}$Na reaction deep underground: Feasibility, setup, and first observation of the 186 keV resonance

Abstract

The ${}^{22}$Ne(p,$\gamma$)${}^{23}$Na reaction takes part in the neon-sodium cycle of hydrogen burning. This cycle is active in asymptotic giant branch stars as well as in novae and contributes to the nucleosythesis of neon and sodium isotopes. In order to reduce the uncertainties in the predicted nucleosynthesis yields, new experimental efforts to measure the ${}^{22}$Ne(p,$\gamma$)${}^{23}$Na cross section directly at the astrophysically relevant energies are needed. In the present work, a feasibility study for a ${}^{22}$Ne(p,$\gamma$)${}^{23}$Na experiment at the Laboratory for Underground Nuclear Astrophysics (LUNA) 400\,kV accelerator deep underground in the Gran Sasso laboratory, Italy, is reported. The ion beam induced $\gamma$-ray background has been studied. The feasibility study led to the first observation of the $E_{\mathrm{p}}$ = 186\,keV resonance in a direct experiment. An experimental lower limit of 0.12\,$\times$\,10${}^{-6}$\,eV has been obtained for the resonance strength. Informed by the feasibility study, a dedicated experimental setup for the ${}^{22}$Ne(p,$\gamma$)${}^{23}$Na experiment has been developed. The new setup has been characterized by a study of the temperature and pressure profiles. The beam heating effect that reduces the effective neon gas density due to the heating by the incident proton beam has been studied using the resonance scan technique, and the size of this effect has been determined for a neon gas target.

Minor errors corrected; final version

References in corpus (11)

• Fast rotating massive stars and the origin of the abundance patterns in galactic globular clusters
• LUNA: Nuclear Astrophysics Deep Underground
• Super and massive AGB stars - III. Nucleosynthesis in metal-poor and very metal-poor stars - Z=0.001 and 0.0001
• Reaction rate uncertainties and the operation of the NeNa and MgAl chains during HBB in intermediate-mass AGB stars
• Ultra-sensitive in-beam gamma-ray spectroscopy for nuclear astrophysics at LUNA
• Feasibility of low energy radiative capture experiments at the LUNA underground accelerator facility
• First Direct Measurement of the ^{17}O(p,γ)^{18}F Reaction Cross-Section at Gamow Energies for Classical Novae
• An actively vetoed Clover gamma-detector for nuclear astrophysics at LUNA
• Direct measurements of 22Na(p,g)23Mg resonances and consequences for 22Na production in classical novae
• Neutron-induced background by an alpha-beam incident on a deuterium gas target and its implications for the study of the 2H(alpha,gamma)6Li reaction at LUNA
• Absolute Determination of the 22Na(p,g) Reaction Rate in Novae

Cited by in corpus (7)

• Direct measurement of low-energy ${}^{22}$Ne(p,$\gamma$)${}^{23}$Na resonances
• ${}^{22}$Ne and ${}^{23}$Na ejecta from intermediate-mass stars: The impact of the new LUNA rate for ${}^{22}$Ne(p,$\gamma$)${}^{23}$Na
• Setup commissioning for an improved measurement of the D(p,gamma)3He cross section at Big Bang Nucleosynthesis energies
• Exploring Stars in Underground Laboratories: Challenges and Solutions
• Underground Measurements of Nuclear Reaction Cross-Sections Relevant to AGB Stars
• Determination of luminosity for in-ring reactions: A new approach for the low-energy domain
• Study of the ${}^{20}$Ne($p,\gamma$)${}^{21}$Na reaction at LUNA