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Super-Kamiokande
Super-Kamiokande (abbreviation of Super-Kamioka Neutrino Detection Experiment, also abbreviated to Super-K or SK; ) is a neutrino detector, neutrino observatory located Kamioka Observatory, under Mount Ikeno near the city of Hida, Gifu, Hida, Gifu Prefecture, Japan. It is operated by the Institute for Cosmic Ray Research, University of Tokyo with the help of an international team. It is located 1,000 m (3,300 ft) underground in the Mozumi Mine in Hida's Kamioka area. The observatory was designed to detect high-energy neutrinos, to search for proton decay, study solar neutrino, solar and neutrino#Atmospheric neutrinos, atmospheric neutrinos, and keep watch for supernovae in the Milky Way galaxy. Description Super-K is located underground in the Mozumi mining, Mine in Hida's Kamioka area. It consists of a cylindrical stainless steel tank that is tall and in diameter holding 50,220 tonnes (55,360 US tons) of ultrapure water. The tank volume is divided by a stainless ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Solar Neutrino
A solar neutrino is a neutrino originating from nuclear fusion in the Sun's core, and is the most common type of neutrino passing through any source observed on Earth at any particular moment. Neutrinos are elementary particles with extremely small rest mass and a neutral electric charge. They only interact with matter via weak interaction and gravity, making their detection very difficult. This has led to the now-resolved solar neutrino problem. Much is now known about solar neutrinos, but research in this field is ongoing. History and background Homestake experiment The timeline of solar neutrinos and their discovery dates back to the 1960s, beginning with the two astrophysicists John N. Bahcall and Raymond Davis Jr. The experiment, known as the Homestake experiment, named after the town in which it was conducted (Homestake, South Dakota), aimed to count the solar neutrinos arriving at Earth. Bahcall, using a solar model he developed, came to the conclusion that the mos ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Kamioka Observatory
The is a neutrino and gravitational waves laboratory located underground in the Mozumi mine of the Kamioka Mining and Smelting Co. near the Kamioka section of the city of Hida in Gifu Prefecture, Japan. A set of groundbreaking neutrino experiments have taken place at the observatory over the past two decades. All of the experiments have been very large and have contributed substantially to the advancement of particle physics, in particular to the study of neutrino astronomy and neutrino oscillation. The mine The Mozumi mine is one of two adjacent mines owned by the Kamioka Mining and Smelting Co. (a subsidiary of the Mitsui Mining and Smelting Co. Mitsui Kinzoku''). The mine is famous as the site of one of the greatest mass-poisonings in Japanese history. From 1910 to 1945, the mine operators released cadmium from the processing plant into the local water. This cadmium caused what the locals called itai-itai disease. The disease caused weakening of the bones and extreme pain. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Neutrino
A neutrino ( ; denoted by the Greek letter ) is an elementary particle that interacts via the weak interaction and gravity. The neutrino is so named because it is electrically neutral and because its rest mass is so small ('' -ino'') that it was long thought to be zero. The rest mass of the neutrino is much smaller than that of the other known elementary particles (excluding massless particles). The weak force has a very short range, the gravitational interaction is extremely weak due to the very small mass of the neutrino, and neutrinos do not participate in the electromagnetic interaction or the strong interaction. Consequently, neutrinos typically pass through normal matter unimpeded and with no detectable effect. Weak interactions create neutrinos in one of three leptonic flavors: # electron neutrino, # muon neutrino, # tau neutrino, Each flavor is associated with the correspondingly named charged lepton. Although neutrinos were long believed to be mas ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Supernova Neutrinos
Supernova neutrinos are weakly interactive elementary particles produced during a core-collapse supernova explosion. A massive star collapses at the end of its life, emitting on the order of 1058 neutrinos and antineutrinos in all lepton flavors. The luminosity of different neutrino and antineutrino species are roughly the same. They carry away about 99% of the gravitational energy of the dying star as a burst lasting tens of seconds. The typical supernova neutrino energies are . Supernovae are considered the strongest and most frequent source of cosmic neutrinos in the MeV energy range. Since neutrinos are generated in the core of a supernova, they play a crucial role in the star's collapse and explosion. Neutrino heating is believed to be a critical factor in supernova explosions. Therefore, observation of neutrinos from supernovae provides detailed information about core collapse and the explosion mechanism. Further, neutrinos undergoing collective flavor conversions in a super ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Proton Decay
In particle physics, proton decay is a hypothetical form of particle decay in which the proton decays into lighter subatomic particles, such as a neutral pion and a positron. The proton decay hypothesis was first formulated by Andrei Sakharov in 1967. Despite significant experimental effort, proton decay has never been observed. If it does decay via a positron, the proton's half-life is constrained to be at least . According to the Standard Model, the proton, a type of baryon, is stable because baryon number ( quark number) is conserved (under normal circumstances; see ''Chiral anomaly'' for an exception). Therefore, protons will not decay into other particles on their own, because they are the lightest (and therefore least energetic) baryon. Positron emission and electron capture—forms of radioactive decay in which a proton becomes a neutron—are not proton decay, since the proton interacts with other particles within the atom. Some beyond-the-Standard-Model grand unifi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Neutrino Detector
A neutrino detector is a physics apparatus which is designed to study neutrinos. Because neutrinos only weakly interact with other particles of matter, neutrino detectors must be very large to detect a significant number of neutrinos. Neutrino detectors are often built underground, to isolate the detector from cosmic rays and other background radiation. The field of neutrino astronomy is still very much in its infancy – the only confirmed extraterrestrial sources are the Sun and the supernova 1987A in the nearby Large Magellanic Cloud. Another likely source (three standard deviations) is the blazar TXS 0506+056 about 3.7 billion light years away. Neutrino observatories will "give astronomers fresh eyes with which to study the universe". Various detection methods have been used. Super Kamiokande is a large volume of water surrounded by phototubes that watch for the Cherenkov radiation emitted when an incoming neutrino creates an electron or muon in the water. The ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gifu Prefecture
is a Prefectures of Japan, prefecture of Japan located in the Chūbu region of Honshu. Gifu Prefecture has a population of 1,910,511 () and has a geographic area of . Gifu Prefecture borders Toyama Prefecture to the north; Ishikawa Prefecture to the northwest, Fukui Prefecture and Shiga Prefecture to the west, Mie Prefecture to the southwest, Aichi Prefecture to the south, and Nagano Prefecture to the east. Gifu is the capital and largest city of Gifu Prefecture, with other major cities including Ōgaki, Kakamigahara, and Tajimi. Gifu Prefecture is located in the center of Japan, one of only eight landlocked prefectures, and features the country's center of population. Gifu Prefecture has served as the historic Intersection (road), crossroads of Japan with routes connecting the east to the west, including the Nakasendō, one of the Edo Five Routes, Five Routes of the Edo period. Gifu Prefecture was a long-term residence of Oda Nobunaga and Saitō Dōsan, two influential figur ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
University Of Tokyo
The University of Tokyo (, abbreviated as in Japanese and UTokyo in English) is a public research university in Bunkyō, Tokyo, Japan. Founded in 1877 as the nation's first modern university by the merger of several pre-westernisation era institutions, its direct precursors include the '' Tenmongata'', founded in 1684, and the Shōheizaka Institute. Although established under its current name, the university was renamed in 1886 and was further retitled to distinguish it from other Imperial Universities established later. It served under this name until the official dissolution of the Empire of Japan in 1947, when it reverted to its original name. Today, the university consists of 10 faculties, 15 graduate schools, and 11 affiliated research institutes. As of 2023, it has a total of 13,974 undergraduate students and 14,258 graduate students. The majority of the university's educational and research facilities are concentrated within its three main Tokyo campuses: Hongō, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Neutrino Astronomy
Neutrino astronomy is a branch of astronomy that gathers information about astronomical objects by observing and studying neutrinos emitted by them with the help of neutrino detectors in special Earth observatories. It is an emerging field in astroparticle physics providing insights into the high-energy and non-thermal processes in the universe. Neutrinos are nearly massless and electrically neutral or chargeless elementary particles. They are created as a result of certain types of radioactive decay, nuclear reactions such as those that take place in the Sun or high energy astrophysical phenomena, in nuclear reactors, or when cosmic rays hit atoms in the atmosphere. Neutrinos rarely interact with matter (only via the weak nuclear force), travel at nearly the speed of light in straight lines, pass through large amounts of matter without any notable absorption or without being deflected by magnetic fields. Unlike photons, neutrinos rarely scatter along their trajectory. But like ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Institute For Cosmic Ray Research
The Institute for Cosmic Ray Research (ICRR) of the University of Tokyo (東京大学宇宙線研究所 ''Tōkyōdaigaku Uchūsen Kenkyūsho'') was established in 1976 for the study of cosmic rays. The gravitational wave studies group is currently constructing the detector KAGRA located at the Kamioka Observatory. Facilities * Kashiwa Campus of the University of Tokyo * Akeno Observatory * Kamioka Observatory * Norikura Observatory Current projects *Super-Kamiokande - Detection of neutrinos and search for proton decays in a large water tank *Tibet - Search for point sources of VHE cosmic gamma rays at Tibet heights *Telescope Array Project - Aiming at highest energy cosmic ray physics by detecting weak light from atmosphere"New Ground-Based Arrays to Probe Cosmic Powerhouses" By Dennis Normile Science 30 April 1999: 734-735 *Gravitational Wave Group - Constructing the gravitational wave detector KAGRA The Kamioka Gravitational Wave Detector (KAGRA) is a large interferometer ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hida, Gifu
or is a Cities of Japan, city located in Gifu Prefecture, Gifu, Japan. , the city had an estimated population of 24,726, and a population density of 31 persons per km2, in 8,905 households. The total area of the city was . The official ''kanji'' for the city is actually 飛驒, which uses the old rendering of the 騨 character. However, the 驒 character is not included on the official list of usable characters (as decided by the Ministry of Internal Affairs and Communications), so the 騨 character is often used outside of the city. Geography Hida is the northernmost city in Gifu Prefecture, and is located in the northern part of the Hida Highlands bordering on Toyama Prefecture to the north. The majority of the area of the city is forested, with many mountains exceeding 1,000 meters within the city borders. The northeastern edge of the Hida Mountains, Hida Mountain range exceeds 2,000 meters. Most of the population is concentrated along river terraces along the Jinzū Ri ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cherenkov Radiation
Cherenkov radiation () is electromagnetic radiation emitted when a charged particle (such as an electron) passes through a dielectric medium (such as distilled water) at a speed greater than the phase velocity (speed of propagation of a wavefront in a medium) of light in that medium. A classic example of Cherenkov radiation is the characteristic blue glow of an underwater nuclear reactor. Its cause is similar to the cause of a sonic boom, the sharp sound heard when faster-than-sound movement occurs. The phenomenon is named after Soviet physicist Pavel Cherenkov. History The radiation is named after the Soviet scientist Pavel Cherenkov, the 1958 Nobel Prize winner, who was the first to detect it experimentally under the supervision of Sergey Vavilov at the Lebedev Institute in 1934. Therefore, it is also known as Vavilov–Cherenkov radiation. Cherenkov saw a faint bluish light around a radioactive preparation in water during experiments. His doctorate thesis was on lumin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
