# Design and construction of the MicroBooNE Cosmic Ray Tagger system

## TL;DR

The paper details the design, construction, and testing of a Cosmic Ray Tagger system for the MicroBooNE detector to identify cosmic muons and reduce background noise in neutrino detection.

## Contribution

It introduces a novel TPC-external CRT system using plastic scintillation modules for precise cosmic muon detection in MicroBooNE.

## Key findings

- Successful matching of TPC and CRT data achieved
- CRT system effectively reduces cosmogenic background
- System performance verified during installation and data-taking

## Abstract

The MicroBooNE detector utilizes a liquid argon time projection chamber (LArTPC) with an 85 t active mass to study neutrino interactions along the Booster Neutrino Beam (BNB) at Fermilab. With a deployment location near ground level, the detector records many cosmic muon tracks in each beam-related detector trigger that can be misidentified as signals of interest. To reduce these cosmogenic backgrounds, we have designed and constructed a TPC-external Cosmic Ray Tagger (CRT). This sub-system was developed by the Laboratory for High Energy Physics (LHEP), Albert Einstein center for fundamental physics, University of Bern. The system utilizes plastic scintillation modules to provide precise time and position information for TPC-traversing particles. Successful matching of TPC tracks and CRT data will allow us to reduce cosmogenic background and better characterize the light collection system and LArTPC data using cosmic muons. In this paper we describe the design and installation of the MicroBooNE CRT system and provide an overview of a series of tests done to verify the proper operation of the system and its components during installation, commissioning, and physics data-taking.