Study heavy elements with exotic beams at ISOLDE (CERN)

Nuclear structure physics has, as a main objective, the study of the nature and the phenomenology of nucleon-nucleon interaction. In the same way than the atoms, nuclear structure can be explained in term of shells (different for protons and neutrons) and the regions around double-shell closures are a benchmark for the study of nuclear structure since they are a direct source of information on the nucleon-nucleon effective interaction in nuclei. Furthermore, these regions are useful to study experimentally since they can be easily described by the nuclear shell model. There are several cases in nature of doubly-magic nuclei but the heaviest known is the 208Pb nucleus. In particular, the south-east region around 208Pb is difficult to study due to experimental limitations such as low cross-section production and limits in the performance of the detectors for such heavy nuclei, so it has not been thoroughly explored so far. Multi-Nucleon Transfer (MNT) reactions are a valid process to produce neutron-rich nuclei around 208Pb and gamma-ray spectroscopy represents one of the most powerful methods to study nuclear structure since a large fraction of the de-excitation of the excited nuclear levels goes via gamma emission. This work will focus on the gamma-ray spectroscopy study of the beam-like and target-like products of a MNT reaction induced via a radioactive 94Rb beam impinging on a 208Pb target. In particular, the cases of 94Zr and 210Pb will be discussed. In the first chapter, the atomic nucleus and different reaction mechanisms used for the production of exotic nuclei, in particular around 208Pb, will be introduced. The second chapter will focus on the experimental facility where the experiment was performed and the setup used for it, for example the gamma and particle detectors. The following two chapters, called "Pre-sorting of the data" and "Data analysis", will discuss the first steps performed for the analysis of the data, the study of the β contaminants, the decay of 94Y into 94Zr, which is one of the major components of the background, and the 210Pb. In the last chapter, "Conclusions and future perspectives", the summary of the results and the conclusions obtained in this thesis will be reported, as well as an introduction to the following experiment.