The detection of Coherent Elastic Neutrino-Nucleus Scattering (CEʋNS) could open a new window on physics beyond the Standard Model.
NUCLEUS is a reactor anti-neutrino experiment conceived for CEʋNS detection using CaWO4 and Al2O3 gram-scale ultra-low energy threshold (20 eV) cryogenic calorimeters.
The detector will be installed in a shallow depth experimental hall located in between the two nuclear reactors of the Chooz B power plant in France, with baselines of 72 m and 102 m, respectively. With an overburden of ~3 m.w.e, this location offers challenging background conditions for the detection of CEʋNS-induced nuclear recoils in the 100 eV range.
We are designing and developing an active cryogenic outer veto (COV) to efficiently identify and reject external backgrounds coming from natural radioactivity and surface cosmic rays. In its final configuration, it will be composed of 6 HPGe crystals (total mass: 4 kg) completely surrounding the inner target detectors.
In this poster, I will present the preliminary results from prototype tests, which allowed us to validate the design of the NUCLEUS COV and to demonstrate the potential of this technique for mitigating external backgrounds in low energy bolometric detection experiments. I will also report on the status and plans for the realization of the NUCLEUS COV.