A simulation-based study of the neutron backgrounds for NaI dark matter experiments

TL;DR

This study uses simulations to evaluate neutron backgrounds in NaI dark matter detectors at two underground labs, assessing shielding effects and implications for WIMP detection signals.

Contribution

It provides a detailed simulation-based analysis of neutron backgrounds with and without shielding, clarifying their impact on dark matter experiments.

Findings

Neutron backgrounds vary significantly with shielding presence.

Polyethylene shielding reduces ambient neutron flux.

Results inform background mitigation strategies for dark matter detection.

Abstract

Among the direct search experiments for weakly interacting massive particle (WIMP) dark matter, the DAMA experiment observed an annual modulation signal interpreted as WIMP interactions with a significance of 9.2$\sigma$. Recently, Jonathan Davis claimed that the DAMA modulation may be interpreted on the basis of the neutron scattering events induced by the muons and neutrinos together. We tried to simulate the neutron backgrounds at the Gran Sasso and Yangyang laboratory with and without the polyethylene shielding to quantify the effects of the ambient neutrons on the direct detection experiments based on the crystals.