Thermonuclear reaction rate of 18O(p,gamma)19F

Abstract

For stars between 0.8-8.0 solar masses, nucleosynthesis enters its final phase during the asymptotic giant branch (AGB) stage. During this evolutionary period, grain condensation occurs in the stellar atmosphere, and the star experiences significant mass loss. The production of presolar grains can often be attributed to this unique stellar environment. A subset of presolar oxide grains features dramatic 18O depletion that cannot be explained by the standard AGB star burning stages and dredge-up models. An extra mixing process, referred to as "cool bottom processing" (CBP), was proposed for low-mass AGB stars. The 18O depletion observed within certain stellar environments and within presolar grain samples may result from the 18O+p processes during CBP. We report here on a study of the 18O(p,gamma)19F reaction at low energies. Based on our new results, we found that the resonance at Er = 95 keV (lab) has a negligible affect on the reaction rate at the temperatures associated with CBP. We also determined that the direct capture S-factor is almost a factor of 2 lower than the previously recommended value at low energies. An improved thermonuclear reaction rate for 18O(p,gamma)19F is presented.

11 pages, 8 figures, 2 tables; to be published in Phys. Rev. C

References in corpus (4)

• Aluminum-, Calcium- And Titanium-Rich Oxide Stardust In Ordinary Chondrite Meteorites
• Line formation in solar granulation VII. CO lines and the solar C and O isotopic abundances
• Measurement of the 20 and 90 keV resonances in the ${}^{18}\mathrm{O}(p,\alpha ){}^{15}$N reaction via THM
• The 14N(p,gamma)15O reaction studied with a composite germanium detector

Cited by in corpus (5)

• Solar fusion III: New data and theory for hydrogen-burning stars
• The effects of a revised ${}^7$Be e${}^{-}$-capture rate on solar neutrino fluxes
• Underground Measurements of Nuclear Reaction Cross-Sections Relevant to AGB Stars
• $\gamma$-ray Spectroscopy using a Binned Likelihood Approach
• The 2025 Evaluation of Experimental Thermonuclear Reaction Rates (ETR25)