A Test System for the JUNO 20-inch PMTs Prior to Installation

TL;DR

This paper describes a test system developed to validate the functionality of 20-inch PMTs for the JUNO experiment before installation, ensuring their performance meets the experiment's strict energy resolution requirements.

Contribution

The paper introduces a dedicated test system for large PMTs and reports initial validation results, supporting quality assurance for JUNO's detector components.

Findings

Test system successfully validated PMT functionality

Initial tests confirmed PMT performance meets specifications

The system ensures reliable deployment of PMTs in JUNO

Abstract

The JUNO experiment requires an excellent energy resolution of 3\% at 1 MeV. To achieve this objective, a total of 20,012 20-inch photomultiplier tubes (PMTs) will be deployed for JUNO, comprising 15,012 multi-channel plate (MCP) PMTs and 5,000 dynode PMTs. Currently, JUNO is in the process of detector installation, with PMTs being installed from the top to the bottom of the stainless-steel structure located in the underground experimental hall. In order to validate the functionality of the PMTs and ensure there are no malfunctions prior to installation, a test system has been established at the JUNO site, and testing is being conducted. This paper presents an overview of the test system and reports on the initial test results.