2 research outputs found

    First inverse kinematics measurement of key resonances in the 22Ne(p, γ)23Na reaction at stellar temperatures

    Get PDF
    In this Letter we report on the first inverse kinematics measurement of key resonances in the 22Ne(p,γ)23Na{}^{22}\text{Ne}(p,\gamma)^{23}\text{Na} reaction which forms part of the NeNa cycle, and is relevant for 23{}^{23}Na synthesis in asymptotic giant branch (AGB) stars. An anti-correlation in O and Na abundances is seen across all well-studied globular clusters (GC), however, reaction-rate uncertainties limit the precision as to which stellar evolution models can reproduce the observed isotopic abundance patterns. Given the importance of GC observations in testing stellar evolution models and their dependence on NeNa reaction rates, it is critical that the nuclear physics uncertainties on the origin of 23{}^{23}Na be addressed. We present results of direct strengths measurements of four key resonances in 22Ne(p,γ)23Na{}^{22}\text{Ne}(p,\gamma)^{23}\text{Na} at Ec.m._{{\text c.m.}} = 149 keV, 181 keV, 248 keV and 458 keV. The strength of the important Ec.m._{{\text c.m.}} = 458 keV reference resonance has been determined independently of other resonance strengths for the first time with an associated strength of ωγ\omega\gamma = 0.439(22) eV and with higher precision than previously reported. Our result deviates from the two most recently published results obtained from normal kinematics measurements performed by the LENA and LUNA collaborations but is in agreement with earlier measurements. The impact of our rate on the Na-pocket formation in AGB stars and its relation to the O-Na anti-correlation was assessed via network calculations. Further, the effect on isotopic abundances in CO and ONe novae ejecta with respect to pre-solar grains was investigated
    corecore