Resonance Strengths in 20Ne(p, γ)22Na and 22Ne(p, γ)23Na and the NeNa Cycle

Stephanie Lyons, University of Notre Dame

In second-generation stars whose stellar temperature T is greater than 0.05 GK, hydrogen burning also can proceed via the NeNa cycle which is important for the nucleosynthesis of the Ne and Na isotopes. The stellar reaction rates for 20Ne(p, γ)21Na are dominated by direct capture and the high energy tail of a subthreshold resonance. The strength of these nonresonant contributions was measured [1] relative to the strength of the resonance at 1.17MeV. Because of conflicting results for this reference [2], we have remeasured the strength of this resonance relative to the well-known 1.28 MeV resonance in Ne(p, γ)23Na using implanted neon targets. In addition, we also performed an independent measurement of the branching ratios and the strength of the 22Ne(p, γ) resonance. [1] C. Rolfs et al., Nuclear Physics A241, 480(1975) [2] J. Keinonen et al., Phys. Rev. C15, 579(1977)

Abstract Author(s): S.Lyons, J. Görres, A. Kontos, E. Stech, and M. Wiescher