Le 5 mai 2017
De 10h30 à 12h00
Guillaume Fruet
IPHC
The knowledge of thermonuclear reaction rates is crucial to understand the energy production and nucleosynthesis in stars. One of the key reactions in the nucleosynthesis process is the 12C+12C fusion, which acts as a trigger for the synthesis of heavier elements. Depending on the mass of the star, carbon burning will occur or not, leading to different scenarios for the death of the star. Ignition of carbon burning depends on the 12C+12C fusion cross section, and is still unknown for stars of ~ 8 – 10 solar masses. Theoretical predictions for this cross section differ by orders of magnitude, and experimental data show discrepancies and large uncertainties going down to astrophysical energies. A new dedicated experimental station has been designed and built at IPHC Strasbourg to measure fusion cross sections in light systems using a particle-gamma coincidence technique. STELLA (STELlar LAboratory) has been installed recently at Orsay around the new Andromède accelerator, which can provide intense carbon beams. Importance of this nuclear reaction in astrophysics scenarios will be explained, as well as the experimental challenges to measure the corresponding fusion cross section. STELLA and the technical developments made in our laboratory will be presented, and we will discuss the first results of the commissioning phase of the experiment.