Speaker
Description
Carbon burning is a crucial stage of stellar evolution, determining whether stars evolve
toward neutron stars, black holes, or CO white dwarfs. These outcomes depend strongly on
the (^{12})C+(^{12})C reaction rate, which is still uncertain at astrophysical energies.
This reaction mainly proceeds through the (^{12})C((^{12})C,(\alpha))(^{20})Ne and
(^{12})C((^{12})C,p)(^{23})Na channels. While it has been studied over a wide energy range,
direct measurements only reach 2.1 MeV, above the astrophysical region. Indirect methods
extend to lower energies, but with significant normalization uncertainties, making new
direct measurements essential.
A direct study is now being carried out by the LUNA collaboration at LNGS using high-
intensity carbon beams and a low-background (\gamma)-detection setup based on a 150% HPGe
detector surrounded by NaI scintillators. This configuration combines high efficiency,
excellent resolution, and strong background suppression, providing a sensitivity much
higher than previous direct experiments.
Besides improving the measurement of the (^{12})C+(^{12})C cross section, this setup will
also allow the study of the level density and possible cluster structure of (^{24})Mg in
the (E_{cm}=1.5)–(3.5) MeV region, which may play an important role in the astrophysical
reaction rate.
In this contribution, I will present the recent progress in setup development and
installation, Geant4 simulations, HPGe detector characterization, and the first beam-on-
target results for the direct study of the (^{12})C+(^{12})C reaction.