Break-out from the hot-CNO cycle studied with radioactive beams

✍ Scribed by A.N. Ostrowski; A.M. Laird; A.C. Shotter; M. Aliotta; F. Cappuzzello; S. Cherubini; A. Cunsolo; T. Davinson; W. Galster; J.S. Graulich; D. Groombridge; J. Hinnefeld; P. Leleux; L. Michel; S. Morrow; A. Musumarra; A. Ninane; A. Spitaleri; A. Tumino; J. Vervier

• Publisher: Elsevier Science
• Year: 2002
• Tongue: English
• Weight: 63 KB
• Volume: 701
• Category: Article
• ISSN: 0375-9474
• DOI: 10.1016/s0375-9474(01)01655-4

✦ Synopsis

The 15 O(α, γ) 19 Ne reaction is generally considered as the potential breakout reaction from the hot-CNO cycle. Under nova conditions, the reaction depends dominantly on a single sub-Coulomb resonance at E c.m. = 504 keV which corresponds to a 19 Ne excitation energy of E R = 4.033 MeV. It is possible to model the 15 O(α, γ) 19 Ne reaction rate, if the branching ratio Γ α /Γ and the total resonance width Γ of this state are known. Results from an exploratory 18 Ne(d, p) experiment performed in inverse kinematics at E lab = 44.1 MeV and 10 6 pps beam intensity show that the 4.033 MeV state-among other resonances of astrophysical interest-is populated in this reaction (dσ/dΩ = 0.5 ± 0.2 mb/sr at θ lab = 138 • ). The determination of Γ α /Γ = 0.28 ± 0.13 for another 19 Ne resonance at E R = 4.600 MeV found to be in good agreement with a stable beam based result shows the feasibility of this radioactive nuclear beam based approach provided that higher 18 Ne beam intensities become available.