Analysis of the light production and propagation in the 4-tonne dual-phase demonstrator

Abstract

The Deep Underground Neutrino Experiment (DUNE) is a leading-edge experiment designed to perform neutrino science and proton decay searches. In particular, the far detector will consist of four 10-kton Liquid Argon (LAr) Time Projection Chambers using both single and dual-phase technologies. The latter provides charge amplification in the gaseous phase. In order to optimize these designs, two large prototypes are taking data at CERN since 2018. Previously, a dual-phase 4-tonne demonstrator was constructed and exposed to cosmic muons in 2017 and exhibited good performance in terms of charge and light collection. The light detection system is important to provide a trigger to the charge acquisition system and to obtain additional information from the scintillation light produced in the particle interaction. In the demonstrator, five cryogenic photo-multipliers were installed with different base polarity configurations and wavelength shifting methods. During the detector operation, scintillation light data were collected in different drift and amplification field conditions. An overview of the light detection system performance and results on the light production and propagation are presented. Our studies allowed us to improve the understanding of some LAr properties.