Calorimeter commissioning of the SuperNEMO Demonstrator

The SuperNEMO experiment is searching for neutrinoless double-beta-decay of ⁸²Se, with the unique combination of a tracking detector and a segmented calorimeter. This feature allows us to detect the two electrons emitted in the decay and measure their individual energies and angular distribution. The SuperNEMO Demonstrator’s calorimeter consists of 712 plastic scintillator blocks read out by large PMTs. Having constructed the calorimeter underground, we performed its first commissioning using γ-rays from calibration sources or from the ambient radioactivity background. This article presents quality assurance tests of the SuperNEMO Demonstrator’s calorimeter, and its first time and energy calibrations with γ-rays, along with the associated methods. A time alignment of about 120 ps and a time resolution around 615 ps have been achieved. Concerning the energy, an alignment of 7.5 % has been obtained. These results will be further improved when associating the tracking detector and detecting electrons from calibration sources.