Study of the ⁷Be(α,γ)¹¹C reaction with DRAGON at vp-process energies

The nucleosynthesis of heavy elements at the neutrino-driven winds of core-collapse supernovae has gained a lot of attention in recent years. One of the proposed scenarios, the νp-process, can account for the production of the light p-nuclei, but it is highly sensitive to both supernova dynamics and nuclear physics input.  In a recent study, it was found that the breakout from pp-chains through the ⁷Be(α,γ)¹¹C reaction, which occurs prior the onset of the νp-process, can significantly influence the reaction flow, and subsequently the production of p-nuclei in the 90 <A<110 region. However, the reaction rate is poorly known over the temperature range of interest (T=1.5-3 GK). To that end, the first direct study of important resonances of the ⁷Be(α,γ)¹¹C reaction with unknown strengths using the DRAGON recoil separator was recently performed at TRIUMF. The reaction was studied in inverse kinematics using a radioactive ⁷Be (t_1/2 = 53.24 d) beam and in the first phase of the experiment two resonances above the ¹¹C α–separation energy (Q_α = 7543.62 keV) were measured. The experimental details and preliminary results from both ⁷Be(α,γ)¹¹C and the benchmark ⁶Li(α,γ)¹⁰Β will be discussed.