Simulation Of Natural Radioactivity Backgrounds In The Juno Central Detector

The Jiangmen Underground Neutrino Observatory (JUNO) is an experiment proposed to determine.the neutrino mass hierarchy and probe the fundamental properties of neutrino oscillation. The JUNO central detector is a spherical liquid scintillator detector with 20 kton fiducial mass. It is required to achieve a 3%/\/E(MeV) energy resolution with very low radioactive background, which is a big challenge to the detector design. In order to ensure the detector performance can meet the physics requirements, reliable detector simulation is necessary to provide useful information for the detector design. A simulation study of natural radioactivity backgrounds in the JUNO central detector has been performed to guide the detector design and set requirements for the radio -purity of the detector materials. The accidental background induced by natural radioactivity in the JUNO central detector is 1.1/day. The result is satisfied for the experiment.