First results on light readout from the 1-ton ArDM liquid argon detector for dark matter searches

TL;DR

This paper reports initial results on light detection in the 1-ton ArDM liquid argon detector, demonstrating promising light yield measurements crucial for advancing dark matter WIMP searches.

Contribution

It presents the first experimental results of the light readout system in the ArDM detector, validating the design with initial surface tests at CERN.

Findings

Light yield at zero electric field is 0.3-0.5 phe/keVee.

Results confirm expectations from smaller detector setups.

First surface test of the light detection system in ArDM.

Abstract

ArDM-1t is the prototype for a next generation WIMP detector measuring both the scintillation light and the ionization charge from nuclear recoils in a 1-ton liquid argon target. The goal is to reach a minimum recoil energy of 30\,keVr to detect recoiling nuclei. In this paper we describe the experimental concept and present results on the light detection system, tested for the first time in ArDM on the surface at CERN. With a preliminary and incomplete set of PMTs, the light yield at zero electric field is found to be between 0.3-0.5 phe/keVee depending on the position within the detector volume, confirming our expectations based on smaller detector setups.