Demonstration of a Lightguide Detector for Liquid Argon TPCs

TL;DR

This paper demonstrates a novel acrylic lightguide detector system for liquid argon TPCs, showing promising results for large-scale, cost-effective light collection in particle physics experiments.

Contribution

It introduces an acrylic lightguide detector with embedded TPB coating for efficient scintillation light detection in liquid argon TPCs, suitable for large-area applications.

Findings

Coating response of 7-8 PE on average

Attenuation length estimated >0.5 meters

Results sufficient for triggering in large detectors

Abstract

We report demonstration of light detection in liquid argon using an acrylic lightguide detector system. This opens the opportunity for development of an inexpensive, large-area light collection system for large liquid argon time projection chambers. The guides are constructed of acrylic, with TPB embedded in a surface coating with a matching index of refraction. We study the response to early scintillation light produced by a 5.3 MeV alpha. We measure coating responses from 7 to 8 PE on average, compared to an ideal expectation of 10 PE on average. We estimate the attenuation length of light along the lightguide bar to be greater than 0.5 m. The coating response and the attenuation length can be improved; we show, however, that these results are already sufficient for triggering in a large detector.