2023, Kudenko, Y., Khotjantsev, A., Mineev, O., Yershov, N., Куденко, Юрий Григорьевич

This paper describes measurements of photosensing units developed for the Outer Detector of Hyper-Kamiokande to increase the effective acceptance of Cherenkov radiation. The photosensing unit consists of a photomultiplier and a wavelength shifting plate optically coupled to it. Plates doped with different fluors and covered by different reflectors were tested using UV LED light sources in air and water. The effects of wavelength shifting fluors, side reflectors, water interface, and shaping of optical coupling are studied. Results of measurements of the light yield and its uniformity are presented. © 2022 Elsevier B.V.