Detection of a giant molecule with a trapped ion cloud ; Détection d'une molécule géante avec un nuage d'ions piégés

A new application for a laser-cooled trapped ion ensemble is proposed for the non-destructive detection of giant molecules. In this application a molecular ion is injected into a Ca+ ion ensemble. The detection signal is expected in the fluorescence of the ion set which may vary after the perturbation induced by the molecule. In this manuscript, the necessary elements for the design and handling of a prototype are presented, as well as experimental and numerical results to validate the concept and to study the operating conditions. The thesis is organised in three parts. The first part presents the fundamental aspects of ion trapping and laser cooling, with an emphasis on the non-adiabatic case the behaviour of more than one ions. Experimental principles and results are also exhibited. The second part deals with the fundamental and experimental aspects of the electrospray ionisation molecular source and its attached guiding elements for charged particle. This part is the opportunity to sum up the recent advances in similar systems. The third part presents the molecular dynamics simulations conducted in order to numerically reproduce the interaction as well as to study the behaviour of the trapped ions. With the simulations, we highlight the key roles of the Coulomb interaction combined with radio-frequency heating in the cloud destabilisation mechanism leading to detection. The conditions favouring detection are studied, as well as certain aspects of ion trapping such as radio-frequency heating. ; Une nouvelle application pour un ensemble d’ions piégés refroidis par laser est proposée pour la détection non-destructive de molécules géantes. Dans cette application, un ion moléculaire est injecté dans un ensemble d’ions Ca+. Le signal de détection est attendu dans la fluorescence de l’ensemble d’ions susceptible de varier après la perturbation induite par la molécule. Dans ce manuscrit, les éléments nécessaires à la conception, la réalisation et le maniement d’un prototype sont présentés, ainsi que les résultats ...