29th USIAS Fellows seminar: Fusion reactions in massive stars: the secret of life

By Sandrine Courtin, USIAS Fellow 2015.

Nuclear reactions feed the stars throughout their lives while producing all the chemical elements that surround us, including those that are indispensable for life itself, such as carbon or oxygen. The research of Sandrine Courtin, Professor of Physics at the University of Strasbourg, consists of reproducing these reactions in the laboratory, in a remarkable combination of nuclear physics and astrophysics.

Fusion is the dominant mechanism in the collisions of heavy-ions at nuclear physics energies. At very low energies, fusion occurs via tunneling through the Coulomb barrier and is strongly sensitive to structure effects of the colliding nuclei, like the formation of nuclear molecules. In this low energy regime, nuclear fusion is strongly connected with astrophysics, as it is an essential step in the synthesis of the chemical elements in massive stars. Indeed, fusion in astrophysical environments often occurs at temperatures which correspond to energies lower than what can be studied in the laboratory, except for a few reactions.
Among these reactions, the knowledge of the carbon+carbon fusion probability at thermonuclear energies is one of the biggest nuclear physics challenges. Sandrine Courtin's USIAS project is focused on the experimental investigation of this reaction, for which molecular states could play an essential role.