Search for CP violation with MORA: Commissioning of the set-up and first experiments

This thesis is part of the search for events involving CP violation. To this end, we are interested in the triple correlation parameter D defined in the Standard Model as zero. D is correlated to the spin of the parent nucleus and to the different momenta of the beta decay products. Spin orientation of the parent nuclei is required to access this parameter. The MORA device is a trapping experiment that maximises this polarisation. The major part of this thesis work consists of studying the experimental setup and its commissioning using a stable beam source. Simulations were carried out to facilitate successful ion trapping.
Commissioning was also carried out in the experimental hall of the physics department at the University of Jyväskylä, where the experiment currently resides. Four 23Mg beam times were used to fine-tune the device, enabling the first usable MORA data to be taken. The characterisation and calibration of the β detectors is also a major part of this work. After an experimental calibration, an attempt was made to improve the latter using simulations, which showed a difference in amplitude between the experimental and simulated spectra.
Various avenues have therefore been explored in order to provide an explanation for these
differences. Finally, this work concludes with the analysis of the first data taken in November
2022.