High resolution collinear resonance ionization spectroscopy of neutron-rich $^{76,77,78}$Cu isotopes

In this work, nuclear magnetic dipole moments, electric quadrupole moments, nuclear spins and changes in the mean-squared charge radii of radioactive copper isotopes are presented. Reaching up to $^{78}$Cu ($Z=29$, $N=49$), produced at rates of only 10 particles per second, these measurements represent the most exotic laser spectroscopic investigations near the doubly-magic and very exotic $^{78}$Ni ($Z=28$,$N=50$) to date. This thesis outlines the technical developments and investigations of laser-atom interactions that were performed during this thesis. These developments were crucial for establishing a high-resolution, high sensitivity collinear resonance ionization spectroscopy experiment at ISOLDE, CERN. This thesis furthermore provides a detailed description of the analysis tools that were implemented and applied to extract the nuclear observables from the experimental data. The results were compared to several large-scale shell model calculations, and provide deep insight into the structure of $^{78}$Ni and the region around it. The importance of excitations across both spin-orbit shell gaps at $Z=28$ and $N=50$ could be investigated through comparison with theory. The structure of the odd-odd neutron-rich copper isotopes in particular proved vitally important. All data was found in agreement with the hypothesis of a doubly-magic $^{78}$Ni nucleus, yet small amounts of core excitations are required to reproduce the observed nuclear moments. Furthermore, the nuclear spins of $^{76,77}$Cu could be unambiguously assigned, which will provide important input for $\beta$-decay studies in the region. Finally, the odd-even staggering of the radii was found to rapidly quench as $N=50$ is approached. Theoretical understanding of this phenomenon will present a challenge for future theoretical investigations of the charge radii of exotic nuclei.