Abstract : The re-evaluation of the theoretical antineutrino flux emitted by nuclear reactors revealed a deficit
of about 6% between the observed flux and the expected one. This so-called reactor antineutrino
anomaly has a statistical significance of 2:7s, and one possible explanation to this deficit could be
the existence of a light sterile neutrino state into which reactor antineutrino oscillate at very short
distances. The STEREO project, which will be presented in this talk, aims to find an evidence of
such oscillation.
The measurement will take place at only few meters (9 m-11 m) from the compact core of the
Institut Laue-Langevin research reactor in Grenoble (France), which provides a large flux of electron
antineutrinos with an energy range from 1 to 10 MeV. The sensitive volume of the STEREO
detector is 2 m3 of organic liquid scintillator doped with Gadolinium, consisting of 6 cells stacked
along the direction of the core and detecting antineutrinos via inverse-b decay.
This setup will provide excellent sensitivity to short-baseline oscillations effects by precisely
measuring any relative distortion of the antineutrino spectrum as a function of both energy and
baseline.
Close proximity to the reactor yield a high background environment that is managed through
heavy shielding surrounding the detector. A water-cerenkov muon veto will be settled above the
detector to tag incoming cosmic muons.
The detector is currently under construction and is expected to deliver its first results in spring
2017.
