%0 Generic
%A Will, Christian
%C Heidelberg
%D 2023
%F heidok:33185
%K Penning trap, Ion trap, laser cooling, sympathetic cooling, precision measurements, antiproton, antimatter
%R 10.11588/heidok.00033185
%T Sympathetic Cooling of Trapped Ions Coupled via Image Currents: Simulation and Measurement
%U https://archiv.ub.uni-heidelberg.de/volltextserver/33185/
%X The ability to transfer the temperature of laser cooled ions to species without a suitable optical cooling transition is of vital interest for the next generation of experiments with trapped ions. For example, our experiment (BASE-Mainz) performs high-precision Penning-trap measurements of the proton magnetic moment. The currently most precise measurement is limited by the non-zero particle temperature of about 1 K. Recently, we have demonstrated the first sympathetic cooling of a single proton with laser cooled  beryllium ions. Here, both species are located in macroscopically separated traps and the coupling is mediated by image currents, which are enhanced via a superconducting RLC circuit. Due to the spatial separation between the target ion and the laser-coolable species, this cooling method can be applied not only to a single proton, but to any charged particle, including exotic particles such as antiprotons or highly-charged ions.  In the course of this thesis, a particle temperature of (160 ± 30) mK was reproducibly achieved for such a sympathetically cooled proton. This constitutes an improvement by a factor of 16 compared to the previous record of (2.6 ± 2.5) K and is a factor of 55 below the  environment temperature. This accomplishment was enabled by two major advancements: First, numerical simulations of the coupled Penning-trap system were developed and carried  out, which significantly progressed the understanding of the coupling and cooling mechanism. Second, a new experimental apparatus was commissioned, which comprises among  other upgrades a dedicated temperature measurement trap. In addition, the simulations were employed to establish future cooling schemes that reach temperatures of 10 mK and  possibly below.