Development of Software for Energy Calibration of the SuperNEMO Detector

AbstraktAbstract

The SuperNEMO experiment was designed to search for neutrinoless double-beta decay. It is an improved version of a very successful predecessor experiment, NEMO-3. The detector uses a tracker-calorimeter technique to measure energies and trajectories of individual particles. Energies are measured by a segmented calorimeter composed of polystyrene scintillator blocks. The calorimeter will be calibrated periodically using an automatic deployment system composed of 42 207Bi calibration sources. 207Bi undergoes internal conversion emitting electrons of energies (mainly 482 keV, 976 keV and 1682 keV). The aim of the presented work is to study possible effects which can potentially influence the quality and efficiency of the calibration. The electrons lose energy in the tracking gas on their trajectory from the calibration source to the calorimeter. This causes an artificial shift of the calibration spectrum to lower energies. It is possible to account for these losses by application of a correction. In the study, we also tested several fitting procedures, which could be applied on energy spectrum obtained during calibration and compared them. The effects were studied using the Monte Carlo simulations of the 207Bi sources in the detector. In the future, we will use real data to deliver the final automatic calibration script.

The SuperNEMO experiment was designed to search for neutrinoless double-beta decay. It is an improved version of a very successful predecessor experiment, NEMO-3. The detector uses a tracker-calorimeter technique to measure energies and trajectories of individual particles. Energies are measured by a segmented calorimeter composed of polystyrene scintillator blocks. The calorimeter will be calibrated periodically using an automatic deployment system composed of 42 207Bi calibration sources. 207Bi undergoes internal conversion emitting electrons of energies (mainly 482 keV, 976 keV and 1682 keV). The aim of the presented work is to study possible effects which can potentially influence the quality and efficiency of the calibration. The electrons lose energy in the tracking gas on their trajectory from the calibration source to the calorimeter. This causes an artificial shift of the calibration spectrum to lower energies. It is possible to account for these losses by application of a correction. In the study, we also tested several fitting procedures, which could be applied on energy spectrum obtained during calibration and compared them. The effects were studied using the Monte Carlo simulations of the 207Bi sources in the detector. In the future, we will use real data to deliver the final automatic calibration script.