Beyond the acceptance limit of DRAGON: The case of the 6Li(α,γ)10B^6Li(\alpha,\gamma )^{10}B reaction

Radiative capture reactions play a pivotal role for our understanding of the origin of the elements in the cosmos. Recoil separators provide an effective way to study these reactions, in inverse kinematics, and take advantage of the use of radioactive ion beams. However, a limiting factor in the study of radiative capture reactions in inverse kinematics is the momentum spread of the product nuclei, which can result in an angular spread larger than the geometric acceptance of the separator. The DRAGON facility at TRIUMF is a versatile recoil separator, designed to study radiative capture reactions relevant to astrophysics in the A ∼ 10–30 region. In this work we present the first attempt to study with DRAGON a reaction, 6 Li( α,γ ) 10 B, for which the recoil angular spread exceeds DRAGON’s acceptance. Our result is in good agreement with the literature value, showing that DRAGON can measure resonance strengths of astrophysically important reactions even when not all the recoils enter the separator

Radiative Alpha Capture on 7Be with DRAGON at Energies Relevant to the \varvec{\nu } p-Process

International audienceThe origin of the p-nuclei, has been a long-standing puzzle in nuclear astrophysics. The $\nu$ p-process is a candidate for the production of the light p-nuclei, but it presents high sensitivity to both supernova dynamics and nuclear physics. It has been recently shown that the breakout from pp-chains through the$^{7}$Be $(\alpha ,\gamma )^{11}$C reaction, which occurs prior to $\nu$ p-process, can significantly influence the reaction flow, and subsequently the production of p-nuclei in the $90<{\text {A}}<110$ region. Nevertheless, this reaction has not been studied well yet in the relevant temperature range - T = 1.5–3 GK. To that end, the first direct study of important resonances of the$^{7}$Be $(\alpha ,\gamma )^{11}$C reaction with unknown strengths using DRAGON was recently performed at TRIUMF. The reaction was studied in inverse kinematics using a radioactive$^{7}$Be (t$_{1/2}$  = 53.24 d) beam provided by ISAC-I and two resonances above the$^{11}$C $\alpha$ -separation energy - Q$_{\alpha } = 7543.62$  keV - were measured. The experimental details, in particular how the recoil transmission and BGO efficiencies were accounted for considering the large cone angle for this reaction, will be presented and discussed alongside some preliminary results