TY  - THES
AU  - Andelkovic, Zoran
TI  - Setup of a Penning trap for precision laser spectroscopy at HITRAP
PB  - Johannes Gutenberg Universität Mainz
VL  - Dr.
CY  - Mainz
M1  - GSI-2013-01047
SP  - 131 p.
PY  - 2012
N1  - http://ubm.opus.hbz-nrw.de/volltexte/2012/3132/
N1  - Johannes Gutenberg Universität Mainz, Diss., 2012
AB  - Ion traps have been established as a powerful tool for ion cooling and laser spectroscopy   experiments since a long time ago. SpecTrap, one of the precision experiments   associated to the HITRAP facility at GSI, is implementing a Penning trap for   studies of large bunches of externally produced highly charged ions. The extremely   strong electric and magnetic fields that exist around the nuclei of heavy elements drastically   change their electronic properties, such as energy level spacings and radiative   lifetimes. The electrons can therefore serve as sensitive probes for nuclear properties   such as size, magnetic moment and spatial distribution of charge and magnetization.   The energies of forbidden fine and hyperfine structure transitions in such ions strongly   depend on the nuclear charge and shift from the microwave domain into the optical   domain. Thus, they become accessible for laser spectroscopy and its potentially high   accuracy. A number of such measurements has been performed in storage rings and   electron beam ion traps and yielded results with relative accuracies in the 10􀀀3 to   10􀀀4 region. This work presents the construction and commissioning of a Penning   trap used for capturing highly charged ions in-flight and cooling them nearly to rest,   thus reducing Doppler broadening and increasing the possible accuracy. As an important   step-stone towards that goal, singly charged Mg ions were produced in an   electron impact ion source, transported to the trap and laser cooled to sub-K temperatures.   Indications of Coulomb crystals formation are reported. Non-destructive   detection of the stored ions was performed both electronically, with the attached cryogenic   resonant circuits, and optically, by observing the fluorescence directly from the   trap centre. The designed electronic components can also be used for resistive cooling,   which becomes particularly efficient for highly charged ions. It was demonstrated   that large ion clouds can be created in the trap, formed by accumulating many consecutive   ion source shots. Ions were stored with lifetimes of the order of 100 s and   cooled to temperatures lower than 60 mK. The same technique can be used in future   experiments for mixing laser-cooled Mg+ with highly charged ions delivered by HITRAP.   Thus, sympathetic cooling of highly charged ions to sub-K temperatures will   become possible. This is sufficient for reducing the Doppler width of a transition in a   heavy ion to several MHz and enables laser spectroscopy experiments with a relative   accuracy up to 10􀀀8.   viii
KW  - Dissertation (GND)
LB  - PUB:(DE-HGF)11
UR  - https://repository.gsi.de/record/49418
ER  -