Speaker
Description
The $^{15}$O($\alpha$,$\gamma$)$^{19}$Ne reaction is a key breakout route from the hot CNO cycle in explosive environments such as type I X-ray bursts. Determining an accurate cross section for the relevant resonant states is critical for a better understanding of the X-ray burst energy production and light-curves, and of the subsequent nucleosynthesis through the $\alpha$p- and rp-processes.
The relevant $^{19}$Ne states for temperatures up to 1 GK were populated using an indirect $^{15}$O($^{7}$Li,t)$^{19}$Ne alpha transfer reaction measurement in inverse kinematics. The experiment used an intense radioactive $^{15}$O beam produced by SPIRAL1 at GANIL and the state-of-the art detection system VAMOS + MUGAST + AGATA, for the detection of the heavy residues, the light charged particles and the de-exciting $\gamma$-rays, respectively. This allowed to reach an unprecedented selectivity for detecting triple coincidences of all final state particles in this reaction.
In this presentation, we will outline the experimental set-up and analysis, providing results for the strongest populated resonances in $^{19}$Ne. In particular, our result with reduced uncertainty for the alpha width of the critical 4.033 MeV excited state will be presented. New astrophysical $^{15}$O($\alpha$,$\gamma$)$^{19}$Ne reaction rates will be presented and the impact on X-ray burst light-curves will be discussed.
