Séminaires
Astrophysics at the Gran Sasso underground laboratory
par
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Europe/Paris
Amphithéâtre
Amphithéâtre
Description
The origin and build up of elements is one of the key questions for our understanding of the universe. Thermonuclear nucleosynthesis processes occurring in stellar and explosive scenarios are responsible for the production of the elements. The talk will focus on the experimental study of quiescent stellar H-burning nuclear reactions. These cross section measurements are extremely difficult due to the very low counting rate (from several events/day to a few events/year) and cosmic background. Some of the main reactions of H-burning phase have been measured at the LUNA facility (Laboratory for Underground Nuclear Astrophysics) taking advantage of the very low background environment of the Underground Gran Sasso National Laboratory in Italy. An overview of the adopted experimental techniques will be given together with the main results obtained for the 14N(p,g)15O and 3He(4He,g)7Be reactions. The first determines the energy production of the CNO cycle and in particular the neutrino flux and is a key ingredient to determine the age of the globular clusters. The latter is one of the most important nuclear reactions for the production of 8B and 7Be neutrinos in the sun. Finally a brief summary of possible future studies that could be performed in a new underground facility will be presented.