Identification of background components with the solid anti-neutrino detector

Abstract

The SoLid experiment aims to measure the anti-neutrino energy spectrum 5.5-10m from the core of the BR2 nuclear reactor at SCK•CEN in Mol, Belgium. The goal is to provide the most sensitive search for short-baseline neutrino oscillations and to resolve the reactor neutrino anomaly. In fact, the proposed detector technology will be very useful for anti-neutrino detection in other settings as well, such as nuclear safeguard and non-proliferation monitoring of nuclear reactors. The experiment utilizes a novel, highly segmented composite scintillator detector. The detector unit is based on 5 cm polyvinyl toluene scintillator cubes, thin neutron sensitive 6LiF:ZnS(Ag) sheets and a reflective Tyvek layer wrapping them for light tight. The first full-scale 288 kg detector prototype based on this technology was deployed at the BR2 reactor in November 2014. The main purpose was to study the capability of the detector design to discriminate background. Due to the low overburden and proximity to a nuclear reactor, efficient background reduction is crucial for a successful experiment. This work presents the advantages of the SoLid detector design for background reduction. The background components discussed in this proceeding are focused on the atmospheric and spallation neutrons induced by cosmic rays. The results are based on a full chain Geant4 based Monte Carlo simulations of the first full-scale SoLid prototype detector, and when applicable, also their comparison with measured data.