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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 gas, noble gases at the SNOLAB, 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 Scintillator, scintilators with xenon and argon have set limits on Weakly-interacting massive particles, WIMP interactions, such as recent cross sections from Large Underground Xenon experiment, LUX and XENON. Particles scattering in the target emit Photon, photons detected by Photo-multiplier tube, PMTs, identified via pulse shape discrimination developed on DEAP results. Shielding reduces the Cosmic background radiation, cosmic and Background radiation, 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 stu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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 observa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Noble Gas
The noble gases (historically also the inert gases; sometimes referred to as aerogens) make up a class of chemical elements with similar properties; under standard conditions, they are all odorless, colorless, monatomic gases with very low chemical reactivity. The six naturally occurring noble gases are helium (He), neon (Ne), argon (Ar), krypton (Kr), xenon (Xe), and the radioactive radon (Rn). Oganesson (Og) is a synthetically produced highly radioactive element. Although IUPAC has used the term "noble gas" interchangeably with "group 18" and thus included oganesson, it may not be significantly chemically noble and is predicted to break the trend and be reactive due to relativistic effects. Because of the extremely short 0.7 ms half-life of its only known isotope, its chemistry has not yet been investigated. For the first six periods of the periodic table, the noble gases are exactly the members of group 18. Noble gases are typically highly unreactive except when u ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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 t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Neon
Neon is a chemical element with the symbol Ne and atomic number 10. It is a noble gas. Neon is a colorless, odorless, inert monatomic gas under standard conditions, with about two-thirds the density of air. It was discovered (along with krypton and xenon) in 1898 as one of the three residual rare inert elements remaining in dry air, after nitrogen, oxygen, argon and carbon dioxide were removed. Neon was the second of these three rare gases to be discovered and was immediately recognized as a new element from its bright red emission spectrum. The name neon is derived from the Greek word, , neuter singular form of (), meaning 'new'. Neon is chemically inert, and no uncharged neon compounds are known. The compounds of neon currently known include ionic molecules, molecules held together by van der Waals forces and clathrates. During cosmic nucleogenesis of the elements, large amounts of neon are built up from the alpha-capture fusion process in stars. Although neon is a very co ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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 complete octe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Scintillator
A scintillator is a material that exhibits scintillation, the property of luminescence, when excited by ionizing radiation. Luminescent materials, when struck by an incoming particle, absorb its energy and scintillate (i.e. re-emit the absorbed energy in the form of light). Sometimes, the excited state is metastable, so the relaxation back down from the excited state to lower states is delayed (necessitating anywhere from a few nanoseconds to hours depending on the material). The process then corresponds to one of two phenomena: delayed fluorescence or phosphorescence. The correspondence depends on the type of transition and hence the wavelength of the emitted optical photon. Principle of operation A scintillation detector or scintillation counter is obtained when a scintillator is coupled to an electronic light sensor such as a photomultiplier tube (PMT), photodiode, or silicon photomultiplier. PMTs absorb the light emitted by the scintillator and re-emit it in the form of ele ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Xenon
Xenon is a chemical element with the symbol Xe and atomic number 54. It is a dense, colorless, odorless noble gas found in Earth's atmosphere in trace amounts. Although generally unreactive, it can undergo a few chemical reactions such as the formation of xenon hexafluoroplatinate, the first noble gas compound to be synthesized. Xenon is used in flash lamps and arc lamps, and as a general anesthetic. The first excimer laser design used a xenon dimer molecule (Xe2) as the lasing medium, and the earliest laser designs used xenon flash lamps as pumps. Xenon is also used to search for hypothetical weakly interacting massive particles and as a propellant for ion thrusters in spacecraft. Naturally occurring xenon consists of seven stable isotopes and two long-lived radioactive isotopes. More than 40 unstable xenon isotopes undergo radioactive decay, and the isotope ratios of xenon are an important tool for studying the early history of the Solar System. Radioactive xenon-135 is ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Weakly-interacting Massive Particles
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 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Large Underground Xenon Experiment
The Large Underground Xenon experiment (LUX) aimed to directly detect weakly interacting massive particle (WIMP) dark matter interactions with ordinary matter on Earth. Despite the wealth of (gravitational) evidence supporting the existence of non- baryonic dark matter in the Universe, dark matter particles in our galaxy have never been directly detected in an experiment. LUX utilized a 370 kg liquid xenon detection mass in a time-projection chamber (TPC) to identify individual particle interactions, searching for faint dark matter interactions with unprecedented sensitivity. The LUX experiment, which cost approximately $10 million to build, was located underground at the Sanford Underground Laboratory (SURF, formerly the Deep Underground Science and Engineering Laboratory, or DUSEL) in the Homestake Mine (South Dakota) in Lead, South Dakota. The detector was located in the Davis campus, former site of the Nobel Prize-winning Homestake neutrino experiment led by Raymond Dav ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
XENON
Xenon is a chemical element with the symbol Xe and atomic number 54. It is a dense, colorless, odorless noble gas found in Earth's atmosphere in trace amounts. Although generally unreactive, it can undergo a few chemical reactions such as the formation of xenon hexafluoroplatinate, the first noble gas compound to be synthesized. Xenon is used in flash lamps and arc lamps, and as a general anesthetic. The first excimer laser design used a xenon dimer molecule (Xe2) as the lasing medium, and the earliest laser designs used xenon flash lamps as pumps. Xenon is also used to search for hypothetical weakly interacting massive particles and as a propellant for ion thrusters in spacecraft. Naturally occurring xenon consists of seven stable isotopes and two long-lived radioactive isotopes. More than 40 unstable xenon isotopes undergo radioactive decay, and the isotope ratios of xenon are an important tool for studying the early history of the Solar System. Radioactive xenon-135 is ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Photon
A photon () is an elementary particle that is a quantum of the electromagnetic field, including electromagnetic radiation such as light and radio waves, and the force carrier for the electromagnetic force. Photons are massless, so they always move at the speed of light in vacuum, (or about ). The photon belongs to the class of bosons. As with other elementary particles, photons are best explained by quantum mechanics and exhibit wave–particle duality, their behavior featuring properties of both waves and particles. The modern photon concept originated during the first two decades of the 20th century with the work of Albert Einstein, who built upon the research of Max Planck. While trying to explain how matter and electromagnetic radiation could be in thermal equilibrium with one another, Planck proposed that the energy stored within a material object should be regarded as composed of an integer number of discrete, equal-sized parts. To explain the photoelectric effect, Eins ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Photo-multiplier Tube
Photomultiplier tubes (photomultipliers or PMTs for short) are extremely sensitive detectors of light in the ultraviolet, visible, and near-infrared ranges of the electromagnetic spectrum. They are members of the class of vacuum tubes, more specifically vacuum phototubes. These detectors multiply the current produced by incident light by as much as 100 million times or 108 (i.e., 160 dB),Decibels are power ratios. Power is proportional to I2 (current squared). Thus a current gain of 108 produces a power gain of 1016, or 160 dB in multiple dynode stages, enabling (for example) individual photons to be detected when the incident flux of light is low. The combination of high gain, low noise, high frequency response or, equivalently, ultra-fast response, and large area of collection has maintained photomultipliers an essential place in low light level spectroscopy, confocal microscopy, Raman spectroscopy, fluorescence spectroscopy, nuclear and particle physics, astronomy, medical ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
