Speaker
Description
The ${}^{16}$O(p,$\alpha$)${}^{13}$N reaction plays a key role in controlling the Ca/Si and Ca/S ratios synthesized during $\alpha$-rich oxygen burning in Type Ia supernovae (SNIa). This reaction feeds the $\alpha$-rich burning branch by converting ${}^{16}$O into ${}^{12}$C via the chain of ${}^{16}$O(p,$\alpha$)${}^{13}$N($\gamma$,p)${}^{12}$C. Moreover, the ${}^{16}$O(p,$\alpha$)${}^{13}$N rate is highly sensitive to the progenitor white dwarf metallicity. However, current models cannot reproduce all observations using standard reaction rate libraries. Moreover, substantial uncertainties (factors $>2$) exist in available ${}^{16}$O(p,$\alpha$)${}^{13}$N rates, presenting challenges for reliably modelling Type Ia supernova nucleosynthesis.
Therefore, a new direct experimental measurements of the ${}^{16}$O(p,$\alpha$)${}^{13}$N reaction cross section, at center-of-mass energies $E_\mathrm{cm} = 6.9-5.6\,\mathrm{MeV}$, using the MUSIC active-target detector at the ATLAS facility at Argonne National Laboratory was performed. The measured cross sections are used to compute the ${}^{16}$O(p,$\alpha$)${}^{13}$N reaction rate at the relevant temperatures for SNIa models. The results from this work will be presented and the implications for SN1a nucleosynthesis discussed.
