A Novel Use of Light Guides and Wavelength Shifting Plates for the Detection of Scintillation Photons in Large Liquid Argon Detectors

TL;DR

This paper evaluates a photon detection technology using light guides and wavelength shifting plates in large liquid argon detectors, combining laboratory and cosmic ray data to measure efficiency and photon yield.

Contribution

It introduces a new photon detector technology for liquid argon detectors and validates its efficiency through combined laboratory and cosmic ray measurements.

Findings

Detection efficiency of 0.48% at the readout end.

Cosmic ray data confirms laboratory efficiency measurements.

Minimum ionizing muons produce approximately 40,000 photons/MeV.

Abstract

Scintillation light generated as charged particles traverse large liquid argon detectors adds valuable information to studies of weakly-interacting particles. This paper uses both laboratory measurements and cosmic ray data from the Blanche dewar facility at Fermilab to characterize the efficiency of the photon detector technology developed at Indiana University for the single phase far detector of DUNE. The efficiency of this technology was found to be 0.48% at the readout end when the detector components were characterized with laboratory measurements. A second determination of the efficiency using cosmic ray tracks is in reasonable agreement with the laboratory determination. The agreement of these two efficiency determinations supports the result that minimum ionizing muons generate ${\mathcal N}_{phot} = 40,000$ photons/MeV as they cross the LAr volume.