Calorimeter R&D for the SuperNEMO double beta decay experiment

SuperNEMO is a next-generation double beta decay experiment based on the successful tracking plus calorimetry technology of the NEMO 3 experiment currently running in the Modane Underground Laboratory. The baseline design uses 82Se as the source. A sensitivity to a 0 ν β β half-life greater than 1026 years can be reached giving access to Majorana neutrino masses of 50–100 meV. SuperNEMO sensitivity is dependent upon the calorimeter parameters such as energy and time resolution, radio-purity and aging. One of the main challenges of the SuperNEMO project is the development of the calorimeter. This calls for an unprecedented energy resolution for plastic scintillators of 4% FWHM at 3 MeV ( Q β β value of 82Se) and radio-purity. The collaboration is carrying out a broad R&D programme focusing on the development of liquid and solid scintillators and ultralow radioactive highly efficient photo-detectors. Extensive laboratory measurements are complimented by the most up-to-date Monte Carlo optical simulations using GEANT4. In parallel an alternative design for SuperNEMO using 2 m scintillator bars as the calorimeter is being investigated and is also discussed.