Upgrading the particle spectrometer SONIC and (p,p'γ) coincidence measurements on Mo-92, Mo-94, and Ni-60

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SONIC@HORUS is a combined particle- and γ-detector array at the Institut für Kernphysik, Universität zu Köln. This thesis describes its upgrade and demonstrates its capability to study high-energy dipole excitations using the particle-γ technique. To enhance particle detection efficiency and improve the overall setup, a complete redesign of the SONIC array was undertaken, resulting in its third version. The characteristics of each version are summarized, highlighting the benefits of the final iteration. The treatment of raw data is tailored to the existing HORUS array and data acquisition, with the introduction of Doppler-shift correction significantly improving γ-ray energy resolution, even at low beam energies of 10 MeV to 15 MeV. An experimental determination of high-energy efficiency up to 7 MeV is also presented to ensure reliable full-energy peak efficiency. The particle-γ method is explained in detail, showcasing its effectiveness in analyzing the excitation and decay behavior of nuclei, particularly when other reaction and decay channels dominate. For the nuclei studied (Mo-92, Mo-94, and Ni-60), a comprehensive comparison to the decay behavior of known low-lying levels is provided. Higher energy excitation patterns from (p, p’γ) measurements are compared with existing (γ,γ’) data. The particle-γ coincidence technique enables the deduction of numerous γ-decay branching ratios to the first three excited states in all th