Fundamental nuclear properties of indium isotopes measured with laser spectroscopy

The primary focus of this thesis is the analysis and interpretation of spectroscopic measurements of the neutron-deficient indium isotopes, 101−115In, in order to evaluate the evolution of nuclear structure towards the heaviest self-conjugate doubly-magic nucleus, 100Sn. These measurements were performed at the Collinear Resonance Ionisation Spectroscopy experiment at the ISOLDE facility at CERN. Two laser excitations were separately employed: between the 5s2 5p 2P1/2 and 5s2 8s 2S1/2 atomic states and between the 5s2 5p 2P3/2 and 5s2 9s 2S1/2 states. Both excitations were followed by non-resonant laser ionisation before ion detection. The work resulted in new nuclear-model-independent measurements of magnetic dipole moments, electric quadrupole moments, nuclear spins and changes in mean-squared charge radii. These properties were determined for the first time in three nuclear ground states, 101,102,103In, and in a number of isomeric states. Comparisons to nuclear theory were performed using predictions of the shell model, droplet model and density functional theory. Previous predictions of simple single-particle behaviour in the Iπ = 9/2+ states of the mid-shell indium isotopes are brought further into question by these new results, due to non-zero trends in the measured magnetic dipole moments. Confidence in the 100Sn shell closure is reinforced by newly measured quadrupole moments, confirming the similar strength of N = 82 and N = 50 at Z = 50. Density functional theory calculations predict the moments relatively well, while finite-range droplet model calculations underestimate the quadrupole-deformation parameters.