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AGASA
The Akeno Giant Air Shower Array (AGASA) is a very large surface array designed to study the origin of ultra-high-energy cosmic rays. Located in the town of Akeno in Yamanashi prefecture, Japan, it covers an area of 100 km2 and consists of 111 surface detectors and 27 muon detectors. Array experiments such as this one are used to detect air shower particles. The array is operated by the Institute for Cosmic Ray Research, University of Tokyo at the Akeno Observatory. Results The results from AGASA were used to calculate the energy spectrum and anisotropy of cosmic rays. The results helped to confirm the existence of ultra-high energy cosmic rays ( >), such as the so-called " Oh-My-God" particle that was observed by the Fly's Eye experiment run by the University of Utah. The Telescope Array, a merger of the AGASA and High Resolution Fly's Eye (HiRes) groups, and the Pierre Auger Observatory have improved on the results from AGASA by building larger, hybrid detectors and colle ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Akeno Observatory
Akeno Observatory is a cosmic ray observatory located in Akeno, a town in Yamanashi prefecture, Japan. The observatory is run by the Institute for Cosmic Ray Research (ICRR), based at the University of Tokyo. Akeno Observatory features AGASA, the Akeno Giant Air Shower Array, which studies the origins of very high energy cosmic rays. Construction of the observatory began in 1975, and in 1977 it became the second attached institution with ICRR. Its accomplishments include the observation of a super high energy cosmic ray air shower in 1995 that was previously thought to be impossible. See also * List of astronomical observatories * List of largest cosmic structures This is a list of the largest cosmic structures so far discovered. The unit of measurement used is the light-year (distance traveled by light in one Julian year; approximately 9.46 trillion kilometres). This list includes superclusters, galaxy ... References Astronomical observatories in Japan Cosmic-ray t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Telescope Array Project
The Telescope Array project is an international collaboration involving research and educational institutions in Japan, The United States, Russia, South Korea, and Belgium. The experiment is designed to observe air showers induced by ultra-high-energy cosmic ray using a combination of ground array and air-fluorescence techniques. It is located in the high desert in Millard County, Utah, United States, at about above sea level. Overview The Telescope Array observatory is a hybrid detector system consisting of both an array of 507 scintillation surface detectors (SD) which measure the distribution of charged particles at the Earth's surface, and three fluorescence stations which observe the night sky above the SD array.T. AbuZayyad et al.,The surface detector array of the Telescope Array experiment Nuclear Instruments and Methods in Physics Research Section A: (2012) vol. 689 Each fluorescence station is also accompanied by a LIDAR system for atmospheric monitoring.M. Chikawa et ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ultra-high-energy Cosmic Ray
In astroparticle physics, an ultra-high-energy cosmic ray (UHECR) is a cosmic ray with an energy greater than 1 EeV (1018 electronvolts, approximately 0.16 joules), far beyond both the rest mass and energies typical of other cosmic ray particles. An extreme-energy cosmic ray (EECR) is an UHECR with energy exceeding (about 8 joule, or the energy of a proton traveling at ≈ % the speed of light), the so-called Greisen–Zatsepin–Kuzmin limit (GZK limit). This limit should be the maximum energy of cosmic ray protons that have traveled long distances (about 160 million light years), since higher-energy protons would have lost energy over that distance due to scattering from photons in the cosmic microwave background (CMB). It follows that EECR could not be survivors from the early universe, but are cosmologically "young", emitted somewhere in the Local Supercluster by some unknown physical process. If an EECR is not a proton, but a nucleus with ''A'' nucleons, then ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Extragalactic Cosmic Ray
Extragalactic cosmic rays are very-high-energy particles that flow into the Solar System from beyond the Milky Way galaxy. While at low energies, the majority of cosmic rays originate within the Galaxy (such as from supernova remnants), at high energies the cosmic ray spectrum is dominated by these extragalactic cosmic rays. The exact energy at which the transition from galactic to extragalactic cosmic rays occurs is not clear, but it is in the range 1017 to 1018 eV. Observation The observation of extragalactic cosmic rays requires detectors with an extremely large surface area, due to the very limited flux. As a result, extragalactic cosmic rays are generally detected with ground-based observatories, by means of the extensive air showers they create. These ground based observatories can be either surface detectors, which observe the air shower particles which reach the ground, or air fluorescence detectors (also called 'fly's eye' detectors), which observe the fluorescence ca ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
High Resolution Fly's Eye Cosmic Ray Detector
The High Resolution Fly's Eye or HiRes detector was an ultra-high-energy cosmic ray observatory that operated in the western Utah desert from May 1997 until April 2006. HiRes used the atmospheric fluorescence technique that was pioneered by the Utah group first in tests at the Volcano Ranch experiment and then with the original Fly's Eye experiment. Hardware and development The High Resolution Fly's Eye used larger mirrors and smaller pixels as compared with the original Fly's Eye, hence the name. A prototype of the HiRes experiment operated between 1993 and 1996 at the original Fly's Eye-I site (Five Mile Hill). It was configured in a tower viewing a narrow wedge of sky from 3–73 degrees in elevation. First the Utah ground array and later the CASA and MIA (ground array and muon array) experiments were placed on the surface in the view of the HiRes prototype. This then became the first "hybrid experiment" collecting information both on the development of the air s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
University Of Tokyo
, abbreviated as or UTokyo, is a public research university located in Bunkyō, Tokyo, Japan. Established in 1877, the university was the first Imperial University and is currently a Top Type university of the Top Global University Project by the Japanese government. UTokyo has 10 faculties, 15 graduate schools and enrolls about 30,000 students, about 4,200 of whom are international students. In particular, the number of privately funded international students, who account for more than 80%, has increased 1.75 times in the 10 years since 2010, and the university is focusing on supporting international students. Its five campuses are in Hongō, Komaba, Kashiwa, Shirokane and Nakano. It is considered to be the most selective and prestigious university in Japan. As of 2021, University of Tokyo's alumni, faculty members and researchers include seventeen prime ministers, 18 Nobel Prize laureates, four Pritzker Prize laureates, five astronauts, and a Fields Medalist. Hist ... [...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 at 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 de ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Anisotropy
Anisotropy () is the property of a material which allows it to change or assume different properties in different directions, as opposed to isotropy. It can be defined as a difference, when measured along different axes, in a material's physical or mechanical properties (absorbance, refractive index, conductivity, tensile strength, etc.). An example of anisotropy is light coming through a polarizer. Another is wood, which is easier to split along its grain than across it. Fields of interest Computer graphics In the field of computer graphics, an anisotropic surface changes in appearance as it rotates about its geometric normal, as is the case with velvet. Anisotropic filtering (AF) is a method of enhancing the image quality of textures on surfaces that are far away and steeply angled with respect to the point of view. Older techniques, such as bilinear and trilinear filtering, do not take into account the angle a surface is viewed from, which can result in aliasing or bl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Oh-My-God Particle
The Oh-My-God particle was an ultra-high-energy cosmic ray detected on 15 October 1991 by the Fly's Eye camera in Dugway Proving Ground, Utah, U.S. It is the highest-energy cosmic ray ever observed. This particle's energy was unexpected and called into question theories of that era about the origin and propagation of cosmic rays. Comparisons The ''Oh-My-God particle''s energy was estimated as , or . Although this amount is phenomenally large – far outstripping the highest energy that humans can generate – it is still far below the level of the Planck scale, where exotic physics is expected. Comparison to a photon The ''Oh-My-God particle'' had (100 quintillion) times the photon energy of visible light, equivalent to a baseball travelling at about . Its energy was 20 million times greater than the highest energy measured in electromagnetic radiation emitted by an extragalactic object: The blazar Markarian 501. Comparison to a proton Assuming it was a pro ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cherenkov Detector
A Cherenkov detector (pronunciation: /tʃɛrɛnˈkɔv/; Russian: Черенко́в) is a particle detector using the speed threshold for light production, the speed-dependent light output or the speed-dependent light direction of Cherenkov radiation. Fundamental A particle passing through a material at a velocity greater than that at which light can travel through the material emits light. This is similar to the production of a sonic boom when an airplane is traveling through the air faster than sound waves can move through the air. The direction this light is emitted is on a cone with angle θc about the direction in which the particle is moving, with cos(θc) = (c = the vacuum speed of light, n = the refractive index of the medium, and v is the speed of the particle). The angle of the cone θc thus is a direct measure of the particle's speed. The Frank–Tamm formula = sin2θc gives the number of photons produced. Aspects Most Cherenkov detectors aim a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
University Of Utah
The University of Utah (U of U, UofU, or simply The U) is a public research university in Salt Lake City, Utah. It is the flagship institution of the Utah System of Higher Education. The university was established in 1850 as the University of Deseret () by the General Assembly of the provisional State of Deseret, making it Utah's oldest institution of higher education. It received its current name in 1892, four years before Utah attained statehood, and moved to its current location in 1900. As of Fall 2019, there were 24,485 undergraduate students and 8,333 graduate students, for an enrollment total of 32,818, making it the second largest public university in the state after Utah Valley University. Graduate studies include the S.J. Quinney College of Law and the School of Medicine, Utah's first medical school. It is a member of the Association of American Universities (AAU) and is classified among "R1: Doctoral Universities – Very high research activity". According to the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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