The veto system of the DarkSide-50 experiment

TL;DR

This paper describes the neutron veto system of DarkSide-50, which actively suppresses and measures neutron-induced backgrounds in the search for WIMP dark matter, detailing its structure, data analysis, and performance.

Contribution

It provides a comprehensive description of the neutron veto system, including design, reconstruction methods, and performance metrics, advancing background mitigation techniques in dark matter detection.

Findings

Effective neutron background suppression achieved

Detailed detector structure and data analysis methods provided

Performance parameters demonstrate system's reliability

Abstract

Nuclear recoil events produced by neutron scatters form one of the most important classes of background in WIMP direct detection experiments, as they may produce nuclear recoils that look exactly like WIMP interactions. In DarkSide-50, we both actively suppress and measure the rate of neutron-induced background events using our neutron veto, composed of a boron-loaded liquid scintillator detector within a water Cherenkov detector. This paper is devoted to the description of the neutron veto system of DarkSide-50, including the detector structure, the fundamentals of event reconstruction and data analysis, and basic performance parameters.