Evaluation of new large area PMT with high quantum efficiency

TL;DR

This paper evaluates a new high-quantum-efficiency 20-inch PMT developed for neutrino detection, demonstrating improved performance metrics over previous models, suitable for large-scale liquid scintillator detectors.

Contribution

It provides a comprehensive performance evaluation of a newly developed high-quantum-efficiency 20-inch PMT for neutrino detectors, highlighting improvements over previous models.

Findings

Quantum efficiency of 30% at 400 nm

Peak/Valley ratio of 4.75 for single photoelectron

Dark count rate of 27 kHz at 3 mV threshold

Abstract

The neutrino detector of the Jiangmen Underground Neutrino Observatory (JUNO) is designed to use 20 kilotons of liquid scintillator and approximately 16,000 20-inch photomultipliers (PMTs).One of the options is to use the 20-inch R12860 PMT with high quantum efficiency which has recently been developed by Hamamatsu Photonics. The performance of the newly developed PMT preproduction samples is evaluated. The results show that its quantum efficiency is $30\%$ at $400 nm$. Its Peak/Valley (P/V) ratio for the single photoelectron is 4.75 and the dark count rate is $27 kHz$ at the threshold of 3 mV while the gain is at $1 \times 10^7$. The transit time spread of a single photoelectron is $2.86 ns$. Generally the performances of this new 20-inch PMT are improved over the old one of R3600.