Hot-CNO breakout through alpha capture on oxygen-15

The astrophysical ¹⁵O alpha capture reaction [1] is a key breakout route from the Hot CNO cycle leading to explosive nucleosynthesis via the rp-process on the surface of neutron stars in binary systems. Determining an accurate cross section for the relevant states is critical for a better understanding of the X-ray burst energy production and light-curves [2], as well as other novel binary stellar systems involving neutron stars and their potential impact on nucleosynthesis [3].

An indirect ⁷Li(¹⁵O,t)¹⁹Ne alpha transfer reaction in inverse kinematics has been performed, populating the relevant states at temperatures up to 1GK. In this, we take advantage of the ¹⁵O Radioactive Ion Beam provided at GANIL and the state-of-the art detection system VAMOS + AGATA + MUGAST coupled together for the first time, allowing us an unrivalled selectivity for detecting triple coincidences in this reaction. We will present the experimental set-up and analysis, as well as preliminary results for the strongest populated resonances in ¹⁹Ne. 

[1] M. R. Hall et al. Phys. Rev. C 99, 035805 (2019)
[2] R. H. Cyburt et al. Astrophys. J. 830, 55 (2016)
[3] J. Keegans et al. MNRAS, V. 485, Issue 1, Pages 620–639 (2019)