Speaker
Description
$\rm^{24}Mg(p,\gamma)^{25}Al$ plays a key role in the Mg–Al cycle, e.g. influencing the chemical evolution of asymptotic giant branch stars and the nucleo-synthesis of intermediate-mass nuclei, notably $\rm ^{26}$Al.
Despite its relevance, the reaction rate at stellar energies remains poorly constrained due to the extremely low cross sections within the sub-resonant Gamow window.
In this talk we present an experimental study on $\rm^{24}Mg(p,\gamma)^{25}Al$ carried out at the Laboratory for Underground Nuclear Astrophysics
(LUNA), located at the low-background environment of the INFN Laboratori Nazionali del Gran Sasso (Italy). We focused on the experimentally accessible energy range between 200 and 400 keV, which includes one narrow resonance and a direct-capture (DC) component. Reaction $\rm \gamma$-rays were acquired using two different setups: a high-efficiency $\rm 4\pi$ BGO detector, optimized for cascade detection, and a HPGe detector.
For the first, a coincidence-based analysis technique was developed exploiting detector segmentation together with compound nucleus de-excitation pattern and energy-gating conditions. This allowed to enhance the detection sensitivity for weak DC signals.
With the second, also thanks to the the excellent energy resolution and stability of the LUNA - 400 accelerator, we improved the determination of the 223~keV resonance energy and provided an independent study of the DC cross section.
Both the measurement campaigns and their results will be presented.
| Category | Experiment |
|---|