Na cross section studied to constrain supernova type Ia nucleosynthesis*

The ²⁰Ne(α,p)²³Na reaction rate is particularly important in predicting final nuclei abundances for type Ia supernovae, especially around temperatures of 5 GK [1]. The corresponding Gamow window for this temperature ranges from 2.4 to 5.4 MeV. Previous studies of this reaction have measured either the ground state, at higher, less astrophysically relevant, energies, or the excited state cross sections, but not both states within the Gamow window [2,3]. Therefore, these act as only estimates of the total cross section for the ²⁰Ne(α,p)²³Na reaction. To address the need for an improved determination of the reaction rate, a cross section measurement was performed for the reaction using the Rhinoceros windowless gas target system and the 5U accelerator at the University of Notre Dame Nuclear Science Lab. The experiment covered 142 energy steps between 2.9 and 5 MeV center of mass energies and probed both ground and first excited states. The experimental data will be shown and preliminary analysis will be discussed.

[1] A. Parikh, J. José, I. R. Seitenzahl, and F. K. Röpke, Astronomy & Astrophysics 557, A3 (2013).

[2] C. Bingham, K. Van Der Borg, R. De Meijer, A. Van Der Woude, Nuclear Physics A323, 26 (1979).

[3] R. Spear and I. Wright, Aust. J. Phys. 21, 307 (1968).