Hyper-Kamiokande, a 260 kton water Cherenkov detector to be built in Japan, is the next generation of the Super-Kamiokande experiment. Its broad physics program includes nucleon decay, neutrinos from astronomical and human-made beam, with the main focus to determine the leptonic CP violation. To detect the weak Cherenkov light generated by neutrino interactions or proton decay, the primary...
Hyper-Kamiokande, scheduled to begin construction as soon as 2020, is a next generation underground water Cherenkov detector, based on the highly successful Super-Kamiokande experiment. It will serve as a far detector, 295 km away, of a long baseline neutrino experiment for the upgraded J-PARC beam in Japan. It will also be a detector capable of observing --- far beyond the sensitivity of the...
Direct measurement of internal properties of the Earth using neutrino has been discussed for more than 30 years. Discovery of the neutrino oscillations opened a new window for geoscience, as well as for particle physics. By measuring matter effect of neutrinos oscillations of atmospheric neutrinos that penetrate through the Earth, and by comparing them with our knowledge of Earth’s density...
The Belle II experiment at the SuperKEKB facility started observation of beam collisions in 2018 to search for the New Physics beyond the Standard Model using 50 times higher statistics of electron-positron collisions of the Belle experiment. The Aerogel Ring Imaging Cherenkov (ARICH) counter is a newly developed particle identification device in the forward endcap of the Belle II spectrometer...
We developed a square-shaped micro-channel-plate photomultiplier tube (MCP-PMT) in collaboration with Hamamatsu Photonics K.K., successfully produced more than 630 MCP-PMTs so far, and installed 512 MCP-PMTs into the TOP counter of the Belle II experiment in 2016. The TOP counter is the first-ever detector that is equipped with such a large number of MCP-PMTs. All the MCP-PMTs have a time...
A Micro-Channel-Plate PMT (MCP-PMT) has an excellent time resolution. A disadvantage of the MCP-PMT is a short photocathode lifetime, which means a drop of the quantum efficiency (QE) of the photocathode. It is a major issue for applications to detector s at high intensity experiments, such as the Belle II TOP detector.
In the first part of the presentation, we talk about the improvement we...
