Super-Kamiokande is the large water Cherenkov detector. The construction was started in 1991 and the observation began on April 1st, 1996. The Super-Kamiokande is operated by an international collaboration of about 150 people and about 40 institutes from Japan, the United States, Korea, China, Poland, Spain, Canada, UK, Italy and France.
The Super-Kamiokande detector consists of a stainless-steel tank, 39.3m diameter and 41.4m tall, filled with 50,000 tons of ultra pure water. About 13,000 photo-multipliers are installed on the tank wall. The detector is located at 1,000 meter underground in the Kamioka-mine, Hida-city, Gifu, Japan.
One of the purposes of the Super-Kamiokande experiment is to reveal the neutrino properties through the observation of solar neutrinos, atmospheric neutrinos and man-made neutrinos. In 1998, from the observation of atmospheric neutrinos we discovered the neutrino oscillations which neutrinos are changing their types in flight. In 2001, solar neutrino oscillations were discovered by the observation of solar neutrinos. In 2011, the third neutrino oscillation mode was discoverd by man-made neutrino observation.
The investigation of the neutrino properties will enable us to understand how matter was created in the early universe. By observation of solar neutrinos, we can know the activities inside of the sun. By detection of neutrinos from supernova burst, we can investigate the details of the explosion mechanism of the star.
On the other hand, the Grand Unified Theories (GUTs), which can unify the fundamental forces of nature, predict that the proton can decay into lighter energetic charged particles. Super-Kamiokande searches for this unknown phenomenon. If the proton decay is observed, it may be possible to prove the GUTs.