The SuperNEMO demonstrator double beta experiment

International audienceThe SuperNEMO experiment will study 82 Se to look for neutrinoless double beta decays (0 νββ ), proof of the Majorana nature of neutrinos. SuperNEMO inherits the tracking-calorimetry technique of NEMO-3, allowing for a clear determination of event kinematics, while aiming for an improved background suppression and 0 νββ sensitivity. A demonstrator module is currently starting operation. The ββ emitting source, ∼ 7 kg of 82 Se in thin foils, is surrounded by a 0.5 meter long helium tracking chamber with 2000 Geiger cells. A 4 π gamma catcher and electron calorimeter, made of plastic scintillators with an energy resolution of 7.8% (FWHM) at 1 MeV, surrounds the tracker. The ultra low radioactivity demonstrator is constructed and installed in the Modane Underground Laboratory in the Frejus Tunnel under the French–Italian Alps