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DEAP
DEAP (Dark matter Experiment using Argon Pulse-shape discrimination) is a direct dark matter search experiment which uses liquid argon as a target material. DEAP utilizes background discrimination based on the characteristic scintillation pulse-shape of argon. A first-generation detector (DEAP-1) with a 7 kg target mass was operated at Queen's University to test the performance of pulse-shape discrimination at low recoil energies in liquid argon. DEAP-1 was then moved to SNOLAB, 2 km below Earth's surface, in October 2007 and collected data into 2011. DEAP-3600 was designed with 3600 kg of active liquid argon mass to achieve sensitivity to WIMP-nucleon scattering cross-sections as low as 10−46 cm2 for a dark matter particle mass of 100 GeV/c2. The DEAP-3600 detector finished construction and began data collection in 2016. An incident with the detector forced a short pause in the data collection in 2016. As of 2019, the experiment is collecting data. To rea ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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SNOLAB
SNOLAB is a Canadian underground science laboratory specializing in neutrino and dark matter physics. Located 2 km below the surface in Vale's Creighton nickel mine near Sudbury, Ontario, SNOLAB is an expansion of the existing facilities constructed for the original Sudbury Neutrino Observatory (SNO) solar neutrino experiment. SNOLAB is the world's deepest operational clean room facility. Although accessed through an active mine, the laboratory proper is maintained as a class-2000 cleanroom, with very low levels of dust and background radiation. SNOLAB's 2070 m (6800 feet) of overburden rock provides 6010 metre water equivalent (MWE) shielding from cosmic rays, providing a low-background environment for experiments requiring high sensitivities and extremely low counting The combination of great depth and cleanliness that SNOLAB affords allows extremely rare interactions and weak processes to be studied. In addition to neutrino and dark matter physics, SNOLAB is also host ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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Dark Matter
Dark matter is a hypothetical form of matter thought to account for approximately 85% of the matter in the universe. Dark matter is called "dark" because it does not appear to interact with the electromagnetic field, which means it does not absorb, reflect, or emit electromagnetic radiation and is, therefore, difficult to detect. Various astrophysical observationsincluding gravitational effects which cannot be explained by currently accepted theories of gravity unless more matter is present than can be seenimply dark matter's presence. For this reason, most experts think that dark matter is abundant in the universe and has had a strong influence on its structure and evolution. The primary evidence for dark matter comes from calculations showing that many galaxies would behave quite differently if they did not contain a large amount of unseen matter. Some galaxies would not have formed at all and others would not move as they currently do. Other lines of evidence include obse ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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Cryogenic Low-Energy Astrophysics With Neon
The Cryogenic Low-Energy Astrophysics with Noble liquids (CLEAN) experiment by the DEAP/CLEAN collaboration is searching for dark matter using noble gases at the SNOLAB underground facility. CLEAN has studied neon and argon in the MicroCLEAN prototype, and running the MiniCLEAN detector to test a multi-ton design. Design Dark matter searches in isolated noble gas scintilators with xenon and argon have set limits on WIMP interactions, such as recent cross sections from LUX and XENON. Particles scattering in the target emit photons detected by PMTs, identified via pulse shape discrimination developed on DEAP results. Shielding reduces the cosmic and radiation background. Neon has been studied as a clear, dense, low-background scintilator. CLEAN can use neon or argon and plans runs with both to study nuclear mass dependence of any WIMP signals. Status The MiniCLEAN detector will operate with argon in 2014. It will have 500 kg of noble cryogen in a spherical steel vessel w ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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Argon
Argon is a chemical element with the symbol Ar and atomic number 18. It is in group 18 of the periodic table and is a noble gas. Argon is the third-most abundant gas in Earth's atmosphere, at 0.934% (9340 ppmv). It is more than twice as abundant as water vapor (which averages about 4000 ppmv, but varies greatly), 23 times as abundant as carbon dioxide (400 ppmv), and more than 500 times as abundant as neon (18 ppmv). Argon is the most abundant noble gas in Earth's crust, comprising 0.00015% of the crust. Nearly all of the argon in Earth's atmosphere is radiogenic argon-40, derived from the decay of potassium-40 in Earth's crust. In the universe, argon-36 is by far the most common argon isotope, as it is the most easily produced by stellar nucleosynthesis in supernovas. The name "argon" is derived from the Greek word , neuter singular form of meaning 'lazy' or 'inactive', as a reference to the fact that the element undergoes almost no chemical reactions. The comp ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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Weakly Interacting Massive Particle
Weakly interacting massive particles (WIMPs) are hypothetical particles that are one of the proposed candidates for dark matter. There exists no formal definition of a WIMP, but broadly, a WIMP is a new elementary particle which interacts via gravity and any other force (or forces), potentially not part of the Standard Model itself, which is as weak as or weaker than the weak nuclear force, but also non-vanishing in its strength. Many WIMP candidates are expected to have been produced thermally in the early Universe, similarly to the particles of the Standard Model according to Big Bang cosmology, and usually will constitute cold dark matter. Obtaining the correct abundance of dark matter today via thermal production requires a self-annihilation cross section of \langle \sigma v \rangle \simeq 3 \times 10^ \mathrm^ \;\mathrm^, which is roughly what is expected for a new particle in the 100 GeV mass range that interacts via the electroweak force. Experimental efforts to detec ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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DarkSide (dark Matter Experiment)
The DarkSide collaboration is an international affiliation of universities and labs seeking to directly detect dark matter in the form of weakly interacting massive particles (WIMPs). The collaboration is planning, building and operating a series of liquid argon time projection chambers (TPCs) that are employed at the Gran Sasso National Laboratory in Assergi, Italy. The detectors are filled with liquid argon from underground sources in order to exclude the radioactive isotope , which makes up one in every 1015 (quadrillion) atoms in atmospheric argon. The Darkside-10 (DS-10) prototype was tested in 2012, and the Darkside-50 (DS-50) experiment has been operating since 2013. Darkside-20k (DS-20k) with 20 tonnes of liquid argon is being planned as of 2019. Darkside-10 The Darkside-10 prototype detector had 10 kg of liquid argon. It was built at Princeton University and operated there for seven months, after which it was transported to Gran Sasso National Laboratory in 2011. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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Tetraphenyl Butadiene
Tetraphenyl butadiene (1,1,4,4-tetraphenyl-1,3-butadiene or TPB) is an organic chemical compound used as an electroluminescent dye. It glows blue with an emission spectrum peak wavelength In physics, the wavelength is the spatial period of a periodic wave—the distance over which the wave's shape repeats. It is the distance between consecutive corresponding points of the same phase on the wave, such as two adjacent crests, tr ... at 430 nm,. which makes it useful as a wavelength shifter. References Fluorescent dyes {{organic-compound-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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Muon
A muon ( ; from the Greek letter mu (μ) used to represent it) is an elementary particle similar to the electron, with an electric charge of −1 '' e'' and a spin of , but with a much greater mass. It is classified as a lepton. As with other leptons, the muon is not thought to be composed of any simpler particles; that is, it is a fundamental particle. The muon is an unstable subatomic particle with a mean lifetime of , much longer than many other subatomic particles. As with the decay of the non-elementary neutron (with a lifetime around 15 minutes), muon decay is slow (by subatomic standards) because the decay is mediated only by the weak interaction (rather than the more powerful strong interaction or electromagnetic interaction), and because the mass difference between the muon and the set of its decay products is small, providing few kinetic degrees of freedom for decay. Muon decay almost always produces at least three particles, which must include an electron o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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Radon-222
Radon-222 (222Rn, Rn-222, historically radium emanation or radon) is the most stable isotope of radon, with a half-life of approximately 3.8 days. It is transient in the decay chain of primordial uranium-238 and is the immediate decay product of radium-226. Radon-222 was first observed in 1899, and was identified as an isotope of a new element several years later. In 1957, the name ''radon'', formerly the name of only radon-222, became the name of the element. Owing to its gaseous nature and high radioactivity, radon-222 is one of the leading causes of lung cancer. History Following the 1898 discovery of radium through chemical analysis of radioactive ore, Marie and Pierre Curie observed a new radioactive substance emanating from radium in 1899 that was strongly radioactive for several days. Around the same time, Ernest Rutherford and Robert B. Owens observed a similar (though shorter-lived) emission from thorium compounds. German physicist Friedrich Ernst Dorn extensively stud ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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Decay Product
In nuclear physics, a decay product (also known as a daughter product, daughter isotope, radio-daughter, or daughter nuclide) is the remaining nuclide left over from radioactive decay. Radioactive decay often proceeds via a sequence of steps (decay chain). For example, 238U decays to 234Th which decays to 234mPa which decays, and so on, to 206Pb (which is stable): : \ce \overbrace^\ce left, upThe decay chain from lead-212 down to lead-208, showing the intermediate decay products In this example: * 234Th, 234mPa,...,206Pb are the decay products of 238U. * 234Th is the daughter of the parent 238U. * 234mPa (234 metastable) is the granddaughter of 238U. These might also be referred to as the daughter products of 238U. (''Depleted Uranium'' — authors: Naomi H. Harley, Ernest C. Foulkes, Lee H. Hilb ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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INFN
The Istituto Nazionale di Fisica Nucleare (INFN; "National Institute for Nuclear Physics") is the coordinating institution for nuclear, particle, theoretical and astroparticle physics in Italy. History INFN was founded on 8 August 1951, to further the nuclear physics research tradition initiated by Enrico Fermi in Rome, in the 1930s. The INFN collaborates with CERN, Fermilab and various other laboratories in the world. In recent years it has provided important contributions to grid computing. During the latter half of the 1950s, the INFN designed and constructed the first Italian electron accelerator—the electron synchrotron developed in Frascati. In the early 1960s, it also constructed in Frascati the first ever electron-positron collider ( ADA - ''Anello Di Accumulazione''), under the scientific leadership of Bruno Touschek. In 1968, Frascati began operating ADONE (''big'' AdA), which was the first high-energy particle collider, having a beam energy of 1.5 GeV. During th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |