First results on ProtoDUNE-SP liquid argon time projection chamber performance from a beam test at the CERN Neutrino Platform

TL;DR

ProtoDUNE-SP, a large liquid argon time projection chamber at CERN, successfully demonstrated high-quality performance metrics in beam tests, validating its design for the DUNE neutrino experiment.

Contribution

This paper reports the first performance results of ProtoDUNE-SP, a prototype detector for DUNE, including calibration, noise, and signal measurements, confirming its readiness for future neutrino research.

Findings

Noise and gain meet specifications

Effective $dE/dx$ calibration achieved

Photon detector performance exceeds expectations

Abstract

The ProtoDUNE-SP detector is a single-phase liquid argon time projection chamber with an active volume of $7.2\times 6.0\times 6.9$ m$^3$. It is installed at the CERN Neutrino Platform in a specially-constructed beam that delivers charged pions, kaons, protons, muons and electrons with momenta in the range 0.3 GeV$/c$ to 7 GeV/$c$. Beam line instrumentation provides accurate momentum measurements and particle identification. The ProtoDUNE-SP detector is a prototype for the first far detector module of the Deep Underground Neutrino Experiment, and it incorporates full-size components as designed for that module. This paper describes the beam line, the time projection chamber, the photon detectors, the cosmic-ray tagger, the signal processing and particle reconstruction. It presents the first results on ProtoDUNE-SP's performance, including noise and gain measurements, $dE/dx$ calibration for muons, protons, pions and electrons, drift electron lifetime measurements, and photon detector noise, signal sensitivity and time resolution measurements. The measured values meet or exceed the specifications for the DUNE far detector, in several cases by large margins. ProtoDUNE-SP's successful operation starting in 2018 and its production of large samples of high-quality data demonstrate the effectiveness of the single-phase far detector design.