Development of a script for calibration of individual optical modules in the segmented calorimeter of the SuperNEMO experiment

AbstraktAbstract

The thesis is dedicated to energy calibration of the SuperNEMO detector. SuperNEMO is an experiment focused on search for the neutrinoless double beta decay — a hypothetical process, the discovery of which would mean a huge step in the field of neutrino physics and particle physics as a whole. For energy measurement, SuperNEMO uses a segmented calorimeter composed of so-called optical modules (OMs). Calibration of the OMs will be performed using electrons emitted by a set of 42 207Bi calibration sources. The measured energy spectrum of these electrons is affected by several effects. The presented work proposes two groups of corrections for these effects: optical corrections and energy loss corrections. It also describes a complete algorithm designed to apply the energy corrections on the calibration data and extract calibration parameters of each individual OM. Finally, the algorithm is used to extract first reliable estimate of OM energy resolutions. These range between 10 and 14% for most modules. As a byproduct gas pressure inside the detector is extracted, resulting in 0.82 bar, close to the actual pressure of 0.88 bar which can be understood as a validation of the energy loss corrections.

The thesis is dedicated to energy calibration of the SuperNEMO detector. SuperNEMO is an experiment focused on search for the neutrinoless double beta decay — a hypothetical process, the discovery of which would mean a huge step in the field of neutrino physics and particle physics as a whole. For energy measurement, SuperNEMO uses a segmented calorimeter composed of so-called optical modules (OMs). Calibration of the OMs will be performed using electrons emitted by a set of 42 207Bi calibration sources. The measured energy spectrum of these electrons is affected by several effects. The presented work proposes two groups of corrections for these effects: optical corrections and energy loss corrections. It also describes a complete algorithm designed to apply the energy corrections on the calibration data and extract calibration parameters of each individual OM. Finally, the algorithm is used to extract first reliable estimate of OM energy resolutions. These range between 10 and 14% for most modules. As a byproduct gas pressure inside the detector is extracted, resulting in 0.82 bar, close to the actual pressure of 0.88 bar which can be understood as a validation of the energy loss corrections.