The 8th international conference on particle physics and astrophysics

Water Cherenkov Detector for Study of Wavelength Shifting Plates

30 Oct 2026, 18:00

15m

Conference Hall 5 ()

Oral talk Facilities and advanced detector technologies Facilities and advanced detector technologies

Description

The Hyper-Kamiokande experiment [1] aims for a search for CP violation in neutrino oscillations, proton decay, measurements of solar and atmospheric neutrinos, and other neutrino physics using a large water Cherenkov detector. The outer veto Chrenkov detector will use about 4000 optical modules based on PMT’s and wavelength-shifting (WLS) plates [2], which enhances light collection efficiency and improves particle identification.

This report describes the prototype of water Cherenkov detector constructed to evaluate the characteristics of WLS plates under conditions of Hyper-Kamiokande. The prototype features a scaled-down water tank and an outer detector module consisting of a 3-inch Hamamatsu R14374 photomultiplier tube (PMT) [3] and a 30 × 30 cm, 7 mm thick WLS plate. The water purification system of this detector has currently achieved a resistivity of approximately 8 MΩ·cm. Parameters of WLS plates were measured using cosmic-ray muons. It was obtained that such a module (PMT plus WLS plate) increases light collection (the number of collected photons) by more than 2 times compared to the light collection of a bare PMT.

Future work will focus on upgrading the water purification system to achieve characteristics approaching those of ultrapure water. Acquiring data to create a Monte Carlo model of the WLS plates' optical characteristics is also a part of the future plans.

Key words: Hyper-Kamiokande outer detector, Water Cherenkov detector, Water purification system, Wavelength-shifting (WLS) plates, Hamamatsu R14374 photomultiplier tube (PMT), PMT coupling, Cherenkov light

1. Hyper-Kamiokande Proto-Collaboration, K. Abe, Ke. Abe, et al. Hyper-Kamiokande Design Report 28 November 2018 https://doi.org/10.48550/arXiv.1805.04163
2. Alexander Izmaylov, Gleb Erofeev, et al. Development of the Wavelength-Shifting Plate Light Collector for the Outer Detector of Hyper-Kamiokande https://doi.org/10.22323/1.468.0112
3. Hamamatsu Photonics K.K., Datasheet “Photomultiplier tubes R14374, R14689” www.hamamatsu.com