Neutrino research projects NNSO has engaged in are Super-Kamiokande and next-generation Hyper-Kamiokande.
Super-Kamiokande is the world’s largest water Cherenkov detector (stainless-steel tank of 39.3m diameter and 41.4m tall filled with 50,000 tons of water, with about 13,000 photo-multipliers on its inside wall) constructed underground at Kamioka, Hida City, Gifu Prefecture in Japan. Its experiment is operated by an international collaboration of about 230 people and about 50 institutes from Japan, the United States, Poland, Korea, China, Spain, Canada, UK, Italy, France and Vietnam. Now, the next-generation detector, Hyper-Kamiokande participated by 22 countries including above is under construction at the same area of Kamioka, being supposed to start operation in 2027. The Hyper-Kamiokande detector is planned to have a fiducial mass of 68.0m diameter and 71.0m tall, eight times greater than its predecessor detector, Super-Kamiokande, and it is equipped with newly developed high-sensitivity 40,000 photosensors.
Our projects of Neutrino aim to address the mysteries of the origin and evolution of the Universe’s matter as well as to confront theories of elementary particle unification, as is described in the following three themes. To realize these goals it will combine a high intensity neutrino beam from J-PARC with a new Hyper-Kamiokande detector based upon precision neutrino experimental techniques developed in Japan and built to be approximately 10 times larger than Super-Kamiokande.