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Compton Telescope
A ''Compton telescope'' (also known as Compton camera or Compton imager) is a gamma-ray detector which utilizes Compton scattering to determine the origin of the observed gamma rays. Compton cameras are usually applied to detect gamma rays in the energy range where Compton scattering is the dominating interaction process, from a few hundred keV to several MeV. They are applied in fields such as astrophysics, nuclear medicine, and nuclear threat detection. In astrophysics, the most famous Compton telescopes was COMPTEL aboard the Compton Gamma Ray Observatory, which pioneered the observation of the gamma-ray sky in the energy range between 0.75 and 30 MeV. A potential successor is NCT NCT may stand for: Tests * National Car Test, Ireland, a roadworthiness test for cars * National Curriculum Tests, in the English education system Organizations and companies * Nashville Children's Theatre, the oldest professional children's thea ... - the Nuclear Compton Telescope. Telescopes ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gamma-ray
A gamma ray, also known as gamma radiation (symbol γ or \gamma), is a penetrating form of electromagnetic radiation arising from the radioactive decay of atomic nuclei. It consists of the shortest wavelength electromagnetic waves, typically shorter than those of X-rays. With frequencies above 30 exahertz (), it imparts the highest photon energy. Paul Villard, a French chemist and physicist, discovered gamma radiation in 1900 while studying radiation emitted by radium. In 1903, Ernest Rutherford named this radiation ''gamma rays'' based on their relatively strong penetration of matter; in 1900 he had already named two less penetrating types of decay radiation (discovered by Henri Becquerel) alpha rays and beta rays in ascending order of penetrating power. Gamma rays from radioactive decay are in the energy range from a few kiloelectronvolts (keV) to approximately 8 megaelectronvolts (MeV), corresponding to the typical energy levels in nuclei with reasonably long lifetimes. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Compton Scattering
Compton scattering, discovered by Arthur Holly Compton, is the scattering of a high frequency photon after an interaction with a charged particle, usually an electron. If it results in a decrease in energy (increase in wavelength) of the photon (which may be an X-ray or gamma ray photon), it is called the Compton effect. Part of the energy of the photon is transferred to the recoiling electron. Inverse Compton scattering occurs when a charged particle transfers part of its energy to a photon. Introduction Compton scattering is an example of elastic scattering of light by a free charged particle, where the wavelength of the scattered light is different from that of the incident radiation. In Compton's original experiment (see Fig. 1), the energy of the X ray photon (≈17 keV) was significantly larger than the binding energy of the atomic electron, so the electrons could be treated as being free after scattering. The amount by which the light's wavelength changes is called t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Compton Camera Principle
Compton may refer to: Places Canada * Compton (electoral district), a former Quebec federal electoral district * Compton (provincial electoral district), a former Quebec provincial electoral district now part of Mégantic-Compton * Compton, Quebec * Compton County, Quebec * Compton Creek, a tributary of the Adam River on Vancouver Island, British Columbia * Compton Island, in the Queen Charlotte Strait region of British Columbia * Compton Névé, a névé (icefield) in the Pacific Ranges, British Columbia ** Compton Glacier, a glacier in the Compton Névé, Pacific Ranges, British Columbia ** Compton Mountain, a mountain in the Compton Névé, Pacific Ranges, British Columbia England * Compton, Berkshire * Compton, Derbyshire, a location * Compton, Plymouth, Devon * Compton, South Hams, a location * Compton, Test Valley, a location * Compton, Hampshire, in Winchester district * Compton, Staffordshire, a location * Compton, Guildford, Surrey * Compton, Waverley, Surrey ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Astrophysics
Astrophysics is a science that employs the methods and principles of physics and chemistry in the study of astronomical objects and phenomena. As one of the founders of the discipline said, Astrophysics "seeks to ascertain the nature of the heavenly bodies, rather than their positions or motions in space–''what'' they are, rather than ''where'' they are." Among the subjects studied are the Sun, other stars, galaxies, extrasolar planets, the interstellar medium and the cosmic microwave background. Emissions from these objects are examined across all parts of the electromagnetic spectrum, and the properties examined include luminosity, density, temperature, and chemical composition. Because astrophysics is a very broad subject, ''astrophysicists'' apply concepts and methods from many disciplines of physics, including classical mechanics, electromagnetism, statistical mechanics, thermodynamics, quantum mechanics, relativity, nuclear and particle physics, and atomic a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nuclear Medicine
Nuclear medicine or nucleology is a medical specialty involving the application of radioactive substances in the diagnosis and treatment of disease. Nuclear imaging, in a sense, is "radiology done inside out" because it records radiation emitting from within the body rather than radiation that is generated by external sources like X-rays. In addition, nuclear medicine scans differ from radiology, as the emphasis is not on imaging anatomy, but on the function. For such reason, it is called a physiological imaging modality. Single photon emission computed tomography (SPECT) and positron emission tomography (PET) scans are the two most common imaging modalities in nuclear medicine. Diagnostic medical imaging Diagnostic In nuclear medicine imaging, radiopharmaceuticals are taken internally, for example, through inhalation, intravenously or orally. Then, external detectors ( gamma cameras) capture and form images from the radiation emitted by the radiopharmaceuticals. This ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Compton Gamma Ray Observatory
The Compton Gamma Ray Observatory (CGRO) was a space observatory detecting photons with energies from 20 k eV to 30 GeV, in Earth orbit from 1991 to 2000. The observatory featured four main telescopes in one spacecraft, covering X-rays and gamma rays, including various specialized sub-instruments and detectors. Following 14 years of effort, the observatory was launched from Space Shuttle ''Atlantis'' during STS-37 on April 5, 1991, and operated until its deorbit on June 4, 2000. It was deployed in low Earth orbit at to avoid the Van Allen radiation belt. It was the heaviest astrophysical payload ever flown at that time at . Costing $617 million, the CGRO was part of NASA's " Great Observatories" series, along with the Hubble Space Telescope, the Chandra X-ray Observatory, and the Spitzer Space Telescope. It was the second of the series to be launched into space, following the Hubble Space Telescope. The CGRO was named after Arthur Compton, an American ph ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nuclear Compton Telescope
The ''Nuclear Compton Telescope'' (NCT) is a balloon-borne Compton telescope to observe the gamma-ray sky in the energy range from a few hundred keV to several MeV. Its main goals are to improve the understanding of Galactic nucleosynthesis, gamma-ray bursts, supernovae, black holes, and more. Instrumentation The Compton telescope uses an array of twelve Germanium detectors with high spectral resolution to detect gamma rays. On its bottom half the detector is surrounded by a Bismuth germanate scintillator to shield it from atmospheric gamma rays. The telescope has an overall field of view (FOV) of 25% of the sky. Flights Since low-to-medium-energy gamma rays are only detectable from above the atmosphere, NCT is launched with a large Helium balloon into the stratosphere. So far NCT had two successful and one unsuccessful balloon campaigns: * A two-detector prototype was successfully test flown on 1 June 2005 from the Scientific Balloon Flight Facility, Fort Sumner, New Mexic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Telescopes
A telescope is a device used to observe distant objects by their emission, absorption, or reflection of electromagnetic radiation. Originally meaning only an optical instrument using lenses, curved mirrors, or a combination of both to observe distant objects, the word ''telescope'' now refers to a wide range of instruments capable of detecting different regions of the electromagnetic spectrum, and in some cases other types of detectors. The first known practical telescopes were refracting telescopes with glass lenses and were invented in the Netherlands at the beginning of the 17th century. They were used for both terrestrial applications and astronomy. The reflecting telescope, which uses mirrors to collect and focus light, was invented within a few decades of the first refracting telescope. In the 20th century, many new types of telescopes were invented, including radio telescopes in the 1930s and infrared telescopes in the 1960s. Etymology The word ''telescope'' wa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
