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Abstract

In this thesis the spectroscopy of the ²P_3/2 → ²P_1/2 M1 fine-structure-transition in Ar¹³⁺-ions at 441nm was examined. Using high precision spectroscopy a verification of a possible drift in the value of the fine-structure constant alpha should be possible. The unique experimental setup enables spectroscopy of ultra-cold and hence precisely localized highly charged ions for the first time. For this purpose the production of boron-like Ar¹³⁺-ions (highly charged ions) was spatially separated from the spectroscopy which takes place in a cryogenic linear Paul trap. Here the Ar¹³⁺-ions are sympathetically cooled to the mK-range in a ⁹Be⁺-Coulomb crystal. For the spectroscopy a long-term stable, but tunable 882nm Titan:Sapphire laser having a 100 kHz linewidth is used, which after frequency-doubling covers the required range. With a Monte Carlo Simulation the necessary spectroscopy-time needed for a clear detection of spontaneous emission in a measuring range is analyzed and evaluated, whether a signal could be surmised after a six-hour measurement in order to limit further measurements of this range. The simulation predicts a signal-like background structure in 20% of the measuring ranges. Out of the seven ranges, this would affect one or two. Using these perceptions a promising measuring range was detected during the actual spectroscopy supporting a measurement from 2016/10.