The neutrino, as a neutral particle can be identical to its antiparticle, i.e, a Majorana particle.
SuperNEMO aims at searching for the neutrinoless double beta decay (0𝜈𝛽𝛽), whose observation
would prove that the neutrino is a Majorana particle.
The 0𝜈𝛽𝛽 process, beyond the Standard Model, is very rare and the level of background should
be extremely small.
One source of background comes from the 222Rn emanation from the detector components or
diffusion from the air of the laboratory towards the tracker. The daughter isotope, of 222Rn, the
214Bi can by (𝛽,𝛾) disintegration produce two electrons with an energy around 3 MeV and therefore
constitute a source of background for 0𝜈𝛽𝛽. The SuperNEMO demonstrator should prove the
capacity to reduce the 222Rn activity to to a level less than 0.15 mBq/m3. Here, I present the
preliminary measurement of the 222Rn activity in the demonstrator, based on first data acquired
without shieldings, without injection of Radon free air in the antiradon tent, and purification of
the tracker gas by the Radon trap.