The multi-Photomultiplier Tube (mPMT) photosensors will be used in the Water Cherenkov Test Experiment (WCTE) to efficiently detect the photons produced in the whole detector. One of the aims behind the development of WCTE is to test the technology and implement it in future water Cherenkov experiments such as the Hyper-Kamiokande experiment and its Intermediate Water Cherenkov Detector. Each mPMT is built using nineteen 3-inch PMTs arranged on a semi-spherical support matrix. In this paper, we describe the design and manufacture of the mechanical components, the procedures for casting an optical gel between PMTs and acrylic cover, and the overall assembly procedure of the mPMTs. Details of the electronics used in the mPMT modules are not included in this paper and will be presented in a separate publication. We also report on the R&D performed on the selection of the optical gel ratio along with transmittance measurements and the reflectance measurements performed on the aluminium reflector. We also present the optical tests performed on the mPMT module using a 405 nm LED and the resulting increase in the effective photosensitive area by surrounding the PMTs with a reflector. A summary of the production and installation of the mPMTs for the WCTE is also presented in this paper.
Assembly, testing, and installation of mPMT photosensor for the Water Cherenkov Test Experiment / Gola, M.; Barbi, M.; Berardi, V.; Buchowicz, A.; Buril, N.; Cook, L.; Cuen-Rochin, S.; Derosa, G.; De Perio, P.; Dygnarowicz, K.; Ferrazzi, B.; Fiorentini, A.; Garde, C. S.; Galiński, G.; Graham, K.; Gornea, R.; Hartz, M.; Holeczek, J.; Jagtap, S.; Kala, M.; Karlen, D.; Kothekar, S.; Koerich, L.; Kolev, N.; Konaka, A.; Kulkarni, A.; Kowalewski, J.; Kurjata, R.; Li, X.; Lindner, T.; Lu, P.; Mache, A.; Marzec, J.; Nikonov, I.; Nurek, M.; Obrębski, W.; Patil, S.; Pastuszak, G.; Piotrowski, B.; Rimmer, J.; Roskovec, B.; Ruggeri, A. C.; Rychter, A.; Satao, K.; Sharma, N.; Stockton, A.; Yousefnejad, S.; Yu, T.; Ziembicki, M.. - In: NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH. SECTION A, ACCELERATORS, SPECTROMETERS, DETECTORS AND ASSOCIATED EQUIPMENT. - ISSN 0168-9002. - ELETTRONICO. - 1081:(2026). [10.1016/j.nima.2025.170903]
Assembly, testing, and installation of mPMT photosensor for the Water Cherenkov Test Experiment
Berardi, V.Membro del Collaboration Group
;
2026
Abstract
The multi-Photomultiplier Tube (mPMT) photosensors will be used in the Water Cherenkov Test Experiment (WCTE) to efficiently detect the photons produced in the whole detector. One of the aims behind the development of WCTE is to test the technology and implement it in future water Cherenkov experiments such as the Hyper-Kamiokande experiment and its Intermediate Water Cherenkov Detector. Each mPMT is built using nineteen 3-inch PMTs arranged on a semi-spherical support matrix. In this paper, we describe the design and manufacture of the mechanical components, the procedures for casting an optical gel between PMTs and acrylic cover, and the overall assembly procedure of the mPMTs. Details of the electronics used in the mPMT modules are not included in this paper and will be presented in a separate publication. We also report on the R&D performed on the selection of the optical gel ratio along with transmittance measurements and the reflectance measurements performed on the aluminium reflector. We also present the optical tests performed on the mPMT module using a 405 nm LED and the resulting increase in the effective photosensitive area by surrounding the PMTs with a reflector. A summary of the production and installation of the mPMTs for the WCTE is also presented in this paper.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
