Item

Abstract

The search for coherent elastic neutrino nucleus scattering is currently among the most popular experimental investigations in neutrino physics. One of the leading reactor experiments is the CONUS experiment, located at 17 m distance to the 3.9 GW_th reactor core of the Brokdorf nuclear power plant in Germany. The four high-purity germanium detectors, enclosed by a compact shield, collected data in five runs from May 2018 to December 2022. After the stopped operation of the Brokdorf reactor, the optimized experiment was relocated to the Swiss nuclear power plant in Leibstadt. This thesis deals with the search for beyond standard model physics, as well as with the optimization for the future operation of CONUS+ with improved detector understanding and technological progress. In the first part of the thesis, a full analysis on neutrino electromagnetic properties was conducted using new data of the last two runs combined with Run-1 and Run-2 data. Here, an upper limit on the neutrino magnetic moment of µ_v < 5.18·10⁻¹¹ µ_B at 90% C.L. was obtained, while the neutrino millicharge analysis yielded an upper limit of |q_v| < 1.76·10⁻¹² e₀. Furthermore, a pulse-shape simulation for the CONUS detectors was set up for future detector and background studies. In the last part of the thesis, the optimized detectors for CONUS+ were characterized and tested. Here, an excellent energy resolution and detection efficiency performance was observed with an unprecedented energy threshold of around 150 eV.