Dissertation / PhD Thesis

GSI-2023-00966

http://join2-wiki.gsi.de/foswiki/pub/Main/Artwork/join2_logo100x88.png Sympathetic Cooling of Trapped Ions Coupled via Image Currents: Simulation and Measurement

Will, C. (Corresponding author)GSI*

2023
Heidelberg University Library Heidelberg

Please use a persistent id in citations: urn:nbn:de:bsz:16-heidok-331853  urn:nbn:de:bsz:16-heidok-331853  doi:10.11588/HEIDOK.00033185

Abstract: 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.

Note: Dissertation, Ruprecht-Karls-Universität Heidelberg, 2023

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Contributing Institute(s):

1. Atom-, Quanten- & Fundamentalphysik (ATP)

Research Program(s):

1. 631 - Matter – Dynamics, Mechanisms and Control (POF4-631) (POF4-631)

Experiment(s):

1. no experiment theory work (theory)

Appears in the scientific report 2023

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