Speaker
Description
Hyper-Kamiokande, the next-generation Water-Cherenkov detector, is being prepared to start operation in 2028 to reveal the neutrino properties and to search for nucleon decays.
It utilizes approximately 20,000 newly designed 50-cm PMTs, which are produced by Hamamatsu Photonics as R12860, to detect the Cherenkov light emitted in the inner detector with higher photon detection efficiency, charge and time resolution, and hydrostatic pressure tolerance much higher than the PMTs used in Super-Kamiokande. The mass production of the PMTs started in 2020 and since then the properties of the delivered PMTs including the response to incoming photons and the amount of the dark noise are measured as a quality assurance. In the measurement, more than hundreds of PMTs are monitored in dedicated dark rooms for one month or longer to check the stability, which is important property as Hyper-Kamiokande is scheduled to be operated for more than 10 years.
Throughout my talk, I will present our measurement setup and the results based on the measurement of more than 2,000 PMTs.
