Simulation of natural radioactivity backgrounds in the central detector

TL;DR

This paper presents a simulation study of natural radioactivity backgrounds in the JUNO neutrino detector to inform design choices and ensure low background levels for accurate neutrino measurements.

Contribution

It provides a detailed simulation of natural radioactivity backgrounds in JUNO's central detector, guiding material radiopurity requirements and detector design.

Findings

Identified key sources of natural radioactivity in the detector

Estimated background levels to meet energy resolution goals

Guided material selection for low-radioactivity components

Abstract

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 $3\%/\sqrt{E(MeV)}$ 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 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 to the radiopurity of detector materials.