Coulomb excitation studies with radioactive ion beams from HIEISOLDE (HIE-ISOLDE)

The major fraction of the visible mass of the universe is situated in the nucleus of the atom: the heart of the matter. This nucleus is a compact object made of protons and neutrons (so-called nucleons) that interact through the strong and the electromagnetic force. Together with the electrons, that surround the nucleus at large distances, it constitutes the atom. While hydrogen (one proton surrounded by one electron) and helium atoms were produced in the very early phase of the universe, most of the heavier atoms (including the once present in our body) are cooked in the stars through nuclear reactions. The aim of the current research project is to investigate the strong interaction through studies of the collective behavior of the nucleons in atoms with an unusual number of protons and/or neutrons. These atoms are radioactive and often live only a fraction of a second. They are not available on earth and have to be produced using large accelerators like the ISOLDE facility at CERN (CH). By transferring them into ion beams and accelerate them to higher energies, allows us to bring the atomic nucleus into a higher lying excited state. These excitations are fingerprints of the collective motion of the nucleons in an atomic nucleus and allow us to verify and modify state-of-the- art nuclear models. In this way we obtain a better understanding on the way the nucleons interact with each other and, indirectly, of stellar evolution.