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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 t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
SNOLAB 2014-03-21
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 to ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Creighton Mine
Creighton Mine is an underground nickel, copper, and platinum-group elements (PGE) mine. It is presently owned and operated by Vale Limited (formerly known as INCO) in the city of Greater Sudbury, Ontario, Canada. Open pit mining began in 1901, and underground mining began in 1906. The mine is situated in the Sudbury Igneous Complex (SIC) in its South Range geologic unit. The mine is the source of many excavation-related seismic events, such as earthquakes and rock burst events. It is home to SNOLAB, and is currently the deepest nickel mine in Canada. Expansion projects to deepen the Creighton Mine are currently underway. History Discovery and development The deposits at Creighton mine were the first mineralized deposits discovered in the Sudbury Igneous Complex (SIC) mining camp. They were discovered by Albert Salter in 1856 due to deflections in his compass readings. Production at Creighton Mine began in 1901 under the Canadian Copper Company, and later the International Ni ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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 reac ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Greater Sudbury
Sudbury, officially the City of Greater Sudbury is the largest city in Northern Ontario by population, with a population of 166,004 at the 2021 Canadian Census. By land area, it is the largest in Ontario and the List of the largest cities and towns in Canada by area, fifth largest in Canada. It is administratively a List of census divisions of Ontario#Single-tier municipalities, single-tier municipality and thus is not part of any district, county, or regional municipality. The City of Greater Sudbury is separate from, but entirely surrounded by the Sudbury District. The city is also referred to as "Grand Sudbury" among Franco-Ontarian, Francophones. The Sudbury region was inhabited by the Ojibwe people of the Algonquin people, Algonquin group for thousands of years prior to the founding of Sudbury after the discovery of nickel ore in 1883 during the construction of the transcontinental railway. Greater Sudbury was formed in 2001 by merging the cities and towns of the former Regi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Helium And Lead Observatory
The Helium And Lead Observatory (HALO) is a neutrino detector at SNOLab for the Supernova Early Warning System (SNEWS). It began engineering operation on May 8, 2012, and joined as an operational part of SNEWS in October 2015. It was designed to be a low-cost, low-maintenance detector with limited capabilities sufficient for the burst of neutrinos generated by a nearby supernova. Its major components are left over from other decommissioned experiments: 76 tons of lead from an earlier cosmic-ray experiment, and 128 three-metre-long helium-3 neutron detectors from the Sudbury Neutrino Observatory. The idea of using lead to detect supernova neutrinos was originally proposed in 1996 by Cliff Hargrove as the "lead astronomical neutrino detector" (LAND), and in 2004, Charles Duba, then a PhD student working on SNO, proposed re-using them for this purpose, prompting the renaming to HALO. Design of the current detector began in 2007. When an electron neutrino collides with a lead nucl ... [...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 dete ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sudbury Neutrino Observatory
The Sudbury Neutrino Observatory (SNO) was a neutrino observatory located 2100 m underground in Vale's Creighton Mine in Sudbury, Ontario, Canada. The detector was designed to detect solar neutrinos through their interactions with a large tank of heavy water. The detector was turned on in May 1999, and was turned off on 28 November 2006. The SNO collaboration was active for several years after that analyzing the data taken. The director of the experiment, Art McDonald, was co-awarded the Nobel Prize in Physics in 2015 for the experiment's contribution to the discovery of neutrino oscillation. The underground laboratory has been enlarged into a permanent facility and now operates multiple experiments as SNOLAB. The SNO equipment itself was being refurbished for use in the SNO+ experiment. Experimental motivation The first measurements of the number of solar neutrinos reaching the Earth were taken in the 1960s, and all experiments prior to SNO observed a third to a ha ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
SNO+
SNO+ is a physics experiment designed to search for neutrinoless double beta decay, with secondary measurements of proton–electron–proton (''pep'') solar neutrinos, geoneutrinos from radioactive decays in the Earth, and reactor neutrinos. It is under construction (as of February 2017) using the underground equipment already installed for the former Sudbury Neutrino Observatory (SNO) experiment at SNOLAB. It could also observe supernovae neutrinos if a supernova occurs in our galaxy. Physics goals The primary goal of the SNO+ detector is the search for neutrinoless double beta decay, specifically with regard to decay of , to understand if a neutrino is its own anti-particle (i.e. a majorana fermion). Secondary physics goals include measurement of neutrinos or antineutrinos from: * Proton-electron-proton (pep) and carbon-nitrogen-oxygen (CNO) cycles within the Sun to better understand neutrino-matter interaction and solar composition. * Beta decay of uranium and thorium wi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Metre Water Equivalent
In physics, the meter water equivalent (often ''m.w.e.'' or ''mwe'') is a standard measure of cosmic ray attenuation in underground laboratories. A laboratory at a depth of 1000 m.w.e is shielded from cosmic rays equivalently to a lab below the surface of a body of water. Because laboratories at the same depth (in meters) can have greatly varied levels of cosmic ray penetration, the m.w.e. provides a convenient and consistent way of comparing cosmic ray levels in different underground locations. Cosmic ray attenuation is dependent on the density of the material of the overburden, so the m.w.e. is defined as the product of depth and density (also known as an interaction depth). Because the density of water is , of water gives an interaction depth of . Some publications use hg/cm² instead of m.w.e., although the two units are equivalent. For example, the Waste Isolation Pilot Plant, located deep in a salt formation, achieves 1585 m.w.e. shielding. Soudan Mine, at depth is o ... [...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] |
Charge-coupled Device
A charge-coupled device (CCD) is an integrated circuit containing an array of linked, or coupled, capacitors. Under the control of an external circuit, each capacitor can transfer its electric charge to a neighboring capacitor. CCD sensors are a major technology used in digital imaging. In a CCD image sensor, pixels are represented by p-doped metal–oxide–semiconductor (MOS) capacitors. These MOS capacitors, the basic building blocks of a CCD, are biased above the threshold for inversion when image acquisition begins, allowing the conversion of incoming photons into electron charges at the semiconductor-oxide interface; the CCD is then used to read out these charges. Although CCDs are not the only technology to allow for light detection, CCD image sensors are widely used in professional, medical, and scientific applications where high-quality image data are required. In applications with less exacting quality demands, such as consumer and professional digital cameras, act ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
China Jinping Underground Laboratory
The China Jinping Underground Laboratory () is a deep underground laboratory in the Jinping Mountains of Sichuan, China. The cosmic ray rate in the laboratory is under 0.2 muons/m2/day, placing the lab at a depth of 6720 meter water equivalent, m.w.e. and making it the best-shielded underground laboratory in the world. The actual depth of the laboratory is , yet there is horizontal access so equipment may be brought in by truck. Although the marble through which the tunnels are dug is considered "Underground mining (hard rock), hard rock", at the great depth it presents greater geotechnical engineering challenges than the even harder igneous rocks in which other deep laboratories are constructed. The water pressure in the rock is also inconvenient. But marble has the advantage for radiation shielding of being low in radionuclides, such as Potassium-40, 40K, Radium-226, 226Ra, Thorium-232, 232Th, and Uranium-238, 238U. This in turn leads to low levels of radon (Radon-2 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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