Laser probing isolated ions Cooling dynamics and electron affinities

by Jose Eduardo Navarro Navarrete (Stockholm University)

Friday 7 Mar 2025, 13:00 → 16:00 Europe/Stockholm

FB52 (AlbaNova Main Building)

Abstract
In this thesis we have studied the stability of ions that are stored in isolation using different laser probing techniques.
Laser photodetachment threshold spectroscopy (LPTS) was used for high-precision measurements of electron affinities,
an inherent property of atomic and molecular systems important for fundamental research and numerous applications,
e.g., for antimatter research or accelerator-based nuclear dating. The measured electron affinities in this thesis include
atomic cesium 133Cs and oxygen 16O, and two fullerenes molecules, C60 and C70. In addition, we have studied the cooling
dynamics of ions, relevant to astrophysics, in new time domains and in unprecedented detail. Here, we implement action
spectroscopy techniques in DESIREE, a cryogenically cooled electrostatic ion-storage ring with outstanding vacuum
conditions. The studied molecules include polycyclic aromatic hydrocarbons (C10H7CN+, C18H12+), carbon chains (C4H−,
C6H−) and fullerenes (C60− and C70− ). These cooling dynamic experiments were aided by ab initio calculations and numerical
simulations in order to unveil the importance of the different relaxation mechanisms that internally excited ions undergo,
which determine their survival probabilities. The results presented in this thesis may play an important role for astrophysical
modelling, which aims to deepen the understanding of the evolution of molecules in outer space.