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Abstract

During the course of this thesis a control system based on EPICS was developed for the Heidelberg electron beam ion trap. This system was employed to inves- tigate recombination and excitation processes in highly charged iridium (atomic number = 77) ions. Iridium atoms were ionized sequentially in the trap by high energy electrons. Free electrons simultaneously recombine with the ions via re- sonant and non-resonant channels. These recombination processes were observed by registering the emitted photons and measuring their energies. By exploiting the x-ray absorption edges of metal foils recombination energies and ionization potentials were obtained by observing the radiative recombination. Furthermore, dielectronic KLL resonances from helium-like to oxygen-like ions were observed and their photon and excitation energies determined. These energies were com- pared with theoretical predictions. The photon energies are in magnitude of 65 keV with a typical uncertainty of 85 eV. The excitation energy determination at ca. 45 keV has uncertainties of only a few eV due to a highly precise voltage divider, and a systematic shift with respect to theory of 20 to 30 eV. Some reso- nances show asymmetric Fano profiles originating from interferences of radiative and dielectronic processes.