The objective of this PhD project is to work on the commissioning plan and the first experiment of the S3 Low Energy Branch (S3-LEB), currently under construction at S3 (Super Separator Spectrometer), as part of the SPIRAL2 facility at the GANIL (Grand Accélérateur National d’Ions Lourds) laboratory in Caen, France. The major attribute of the S3-LEB is to use atomic physics techniques - more specifically, high resolution spectral measurements of the atomic transitions – in order to provide fundamental and nuclear-model-independent data on the structure of ground and isomeric nuclear states. In this context, this setup will allow the measurements of static properties of exotic nuclei such as charge radii, electromagnetic moments, nuclear spins and atomic masses, giving information on the distribution of the nucleons inside the nucleus and providing information on structural changes throughout the chart of nuclei. This state-of-the-art technique will be used at S3 with rare beams never studied by low-energy measurements.