Light detection and Cosmic Rejection in the ICARUS LArTPC at Fermilab

TL;DR

This paper discusses the methods used in the ICARUS LArTPC detector at Fermilab to detect light signals and reject cosmic ray backgrounds, enhancing neutrino detection accuracy.

Contribution

It introduces a novel approach for cosmic rejection and timing calibration of the light detection systems in the ICARUS LArTPC at Fermilab.

Findings

Effective cosmic ray background reduction achieved

Precise timing calibration improves event origin identification

Enhanced neutrino detection fidelity

Abstract

The ICARUS-T600 detector is a 760-ton Liquid Argon Time Projection Chamber (LArTPC) currently operating at Fermilab as the Far Detector in the Short Baseline Neutrino (SBN) program. The SBN program is composed of three LArTPCs with a central goal of testing the sterile neutrino hypothesis. After operating for 3-years in the Gran Sasso Underground Laboratory, the ICARUS detector was shipped to CERN where it was outfitted with 360 8" Photomultiplier Tubes (PMTs) for a new optical detection system. The PMT system detects fast scintillation light from charged particles interacting in the Liquid Argon, generating the trigger signal for the full detector and allows 3D reconstruction of events. Now operating at shallow depth, the detector is exposed to a high flux of cosmic rays that can fake neutrino interactions. To mitigate this effect a Cosmic Ray Tagger (CRT) and a 3-meter-thick concrete were installed. Precise timing information from both the PMT and CRT subsystems can help to identify whether an interaction originated from inside or outside of the ICARUS cryostat. This paper reviews a method for cosmogenic background reduction and timing calibration of the CRT and PMT light detection systems in ICARUS.