Speaker
Description
Hyper-Kamiokande is a large water Cherenkov detector planned in the near future. A fiducial volume of Hyper-Kamiokande is about twenty times larger than Super-Kamiokande.
It is equipped with forty thousands of a 50 cm photomultiplier tube (PMT), R12860 by Hamamatsu Photonics K.K.
The PMT has a high quantum efficiency, faster time response, better charge resolution and a higher detection efficiency with a stable mechanical structure, compared to the PMTs in Super-Kamiokande.
The detection efficiency of the R12860 is double by the Super-Kamiokande PMTs, but the obtained current dark hit rate is relatively high compared to the Super-Kamiokande PMT.
A reduction of the dark hit rate can improve physics sensitivities of Hyper-Kamiokande.
Since a light derived from PMT glass could contribute to the dark hit rate, I investigate the light background of the PMT glass.
