Snolab
Encyclopedia
SNOLAB is a Canadian
underground physics
laboratory
at a depth of 2 km in Sudbury, Ontario
in Vale's Creighton
nickel
mine
. The original Sudbury Neutrino Observatory
(SNO) experiment has ended, but the facilities have been expanded into a permanent underground laboratory.
SNOLAB is the world's deepest underground lab facility; the deeper Kolar Gold Fields experiments
ended with the closing of the mine in 1992, and the planned DUSEL laboratory is not expected to begin construction before 2012.
Although accessed through a dirty commercial mine, the laboratory proper is maintained as a class-2000 cleanroom
, with very low levels of dust
and background radiation
. The 6800 ft (2070 m) overburden of rock provides 6010 metres of water equivalent (MWE) shielding from cosmic ray
s, providing a low-background environment for experiments requiring high sensitivities
and extremely low counting rates.
A large deep cavity
was originally constructed for the SNO experiment, but other groups were interested in conducting experiments in the very deep location. In 2002 funding was approved by the Canada Foundation for Innovation
to expand the SNO facilities into a general-purpose laboratory, and more funding was received in 2007 and 2008.
Construction of the major laboratory space was completed in 2009, with the entire lab entering operation as a 'clean' space in March 2011.
s:
Four more experiments are currently under construction:
Additional experiments have requested laboratory space, the EXO
neutrinoless double beta decay
detector, and several dark matter detectors: SuperCDMS
and DarkSide.
The total size of the SNOlab underground facilities, including utility spaces and personnel spaces, is:
Canada
Canada is a North American country consisting of ten provinces and three territories. Located in the northern part of the continent, it extends from the Atlantic Ocean in the east to the Pacific Ocean in the west, and northward into the Arctic Ocean...
underground physics
Physics
Physics is a natural science that involves the study of matter and its motion through spacetime, along with related concepts such as energy and force. More broadly, it is the general analysis of nature, conducted in order to understand how the universe behaves.Physics is one of the oldest academic...
laboratory
Laboratory
A laboratory is a facility that provides controlled conditions in which scientific research, experiments, and measurement may be performed. The title of laboratory is also used for certain other facilities where the processes or equipment used are similar to those in scientific laboratories...
at a depth of 2 km in Sudbury, Ontario
Ontario
Ontario is a province of Canada, located in east-central Canada. It is Canada's most populous province and second largest in total area. It is home to the nation's most populous city, Toronto, and the nation's capital, Ottawa....
in Vale's Creighton
Creighton Mine
Creighton Mine is an underground nickel mine, owned and operated by Vale Inco Limited in the city of Greater Sudbury, Ontario, Canada...
nickel
Nickel
Nickel is a chemical element with the chemical symbol Ni and atomic number 28. It is a silvery-white lustrous metal with a slight golden tinge. Nickel belongs to the transition metals and is hard and ductile...
mine
Mining
Mining is the extraction of valuable minerals or other geological materials from the earth, from an ore body, vein or seam. The term also includes the removal of soil. Materials recovered by mining include base metals, precious metals, iron, uranium, coal, diamonds, limestone, oil shale, rock...
. The original Sudbury Neutrino Observatory
Sudbury Neutrino Observatory
The Sudbury Neutrino Observatory is a neutrino observatory located 6,800 feet underground in Vale Inco'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 turned on in May 1999,...
(SNO) experiment has ended, but the facilities have been expanded into a permanent underground laboratory.
SNOLAB is the world's deepest underground lab facility; the deeper Kolar Gold Fields experiments
Particle experiments at Kolar Gold Fields
The Kolar Gold Fields , located in the Kolar district of the state of Karnataka, India, are a set of defunct gold mines known for the neutrino particle experiments and observations that took place here starting in 1960...
ended with the closing of the mine in 1992, and the planned DUSEL laboratory is not expected to begin construction before 2012.
Although accessed through a dirty commercial mine, the laboratory proper is maintained as a class-2000 cleanroom
Cleanroom
A cleanroom is an environment, typically used in manufacturing or scientific research, that has a low level of environmental pollutants such as dust, airborne microbes, aerosol particles and chemical vapors. More accurately, a cleanroom has a controlled level of contamination that is specified by...
, with very low levels of dust
Dust
Dust consists of particles in the atmosphere that arise from various sources such as soil dust lifted up by wind , volcanic eruptions, and pollution...
and background radiation
Background radiation
Background radiation is the ionizing radiation constantly present in the natural environment of the Earth, which is emitted by natural and artificial sources.-Overview:Both Natural and human-made background radiation varies by location....
. The 6800 ft (2070 m) overburden of rock provides 6010 metres of water equivalent (MWE) shielding from cosmic ray
Cosmic ray
Cosmic rays are energetic charged subatomic particles, originating from outer space. They may produce secondary particles that penetrate the Earth's atmosphere and surface. The term ray is historical as cosmic rays were thought to be electromagnetic radiation...
s, providing a low-background environment for experiments requiring high sensitivities
Sensitivity (electronics)
The sensitivity of an electronic device, such as a communications system receiver, or detection device, such as a PIN diode, is the minimum magnitude of input signal required to produce a specified output signal having a specified signal-to-noise ratio, or other specified criteria.Sensitivity is...
and extremely low counting rates.
History
Cavity
A cavity is a hole. It may refer to:*Dental cavity, damage to the structure of teeth*Body cavity, a fluid filled space in many animals where organs typically develop*Cavity wall, a wall consisting of two skins with a cavity....
was originally constructed for the SNO experiment, but other groups were interested in conducting experiments in the very deep location. In 2002 funding was approved by the Canada Foundation for Innovation
Canada Foundation for Innovation
Created by the Government of Canada in 1997, the Canada Foundation for Innovation strives to build our nation’s capacity to undertake world-class research and technology development to benefit Canadians...
to expand the SNO facilities into a general-purpose laboratory, and more funding was received in 2007 and 2008.
Construction of the major laboratory space was completed in 2009, with the entire lab entering operation as a 'clean' space in March 2011.
Experiments
It currently hosts three experimentExperiment
An experiment is a methodical procedure carried out with the goal of verifying, falsifying, or establishing the validity of a hypothesis. Experiments vary greatly in their goal and scale, but always rely on repeatable procedure and logical analysis of the results...
s:
- The PICASSOPICASSO (dark matter)The PICASSO ' experiment is an experiment searching for direct evidence of dark matter...
dark matterDark matterIn astronomy and cosmology, dark matter is matter that neither emits nor scatters light or other electromagnetic radiation, and so cannot be directly detected via optical or radio astronomy...
search, - The POLARISPOLARIS (seismology)POLARIS is an underground experiment to observe seismic signals at depth in very hard rock. It is one of the current projects at SNOLAB in Canada....
underground project at SNOLAB (PUPS), observing seismic signals at depth in very hard rockHard rockHard rock is a loosely defined genre of rock music which has its earliest roots in mid-1960s garage rock, blues rock and psychedelic rock...
, and - The DEAPDEAPDEAP is a direct dark matter search experiment using liquid argon as target material. DEAP utilizes background discrimination based on the characteristic scintillation pulse shape in argon...
-1 dark matterDark matterIn astronomy and cosmology, dark matter is matter that neither emits nor scatters light or other electromagnetic radiation, and so cannot be directly detected via optical or radio astronomy...
search.
Four more experiments are currently under construction:
- The SNO+SNO+SNO+ is an underground physics experiment under construction that makes use of the equipment already installed underground for the former Sudbury Neutrino Observatory experiment at SNOLAB...
neutrinoNeutrinoA neutrino is an electrically neutral, weakly interacting elementary subatomic particle with a half-integer spin, chirality and a disputed but small non-zero mass. It is able to pass through ordinary matter almost unaffected...
detector (using the original SNO experiment chamber), - MiniCLEAN dark matter detector,
- The second-generation DEAP-3600 dark matter detector, and
- The HALO (Helium and Lead Observatory) supernovaSupernovaA supernova is a stellar explosion that is more energetic than a nova. It is pronounced with the plural supernovae or supernovas. Supernovae are extremely luminous and cause a burst of radiation that often briefly outshines an entire galaxy, before fading from view over several weeks or months...
neutrino detector. - The COUPP 4-kg bubble chamber dark matter search.
Additional experiments have requested laboratory space, the EXO
Enriched Xenon Observatory
The Enriched Xenon Observatory is a particle physics experiment searching for double beta decay of xenon-136. The experiment uses a large amount of xenon, isotopically enriched in xenon-136...
neutrinoless double beta decay
Double beta decay
Double beta decay is a radioactive decay process where a nucleus releases two beta rays as a single process.In double-beta decay, two neutrons in the nucleus are converted to protons, and two electrons and two electron antineutrinos are emitted...
detector, and several dark matter detectors: SuperCDMS
Cryogenic Dark Matter Search
The Cryogenic Dark Matter Search is a series of experiments designed to directly detect particle dark matter in the form of WIMPs. Using an array of semiconductor detectors at millikelvin temperatures, CDMS has set the most sensitive limits to date on the interactions of WIMP dark matter with...
and DarkSide.
The total size of the SNOlab underground facilities, including utility spaces and personnel spaces, is:
| Excavated | Clean room | Laboratory | |
|---|---|---|---|
| Floor space | 7215 m² 77,636 ft² |
4942 m² 53,180 ft² |
3055 m² 32,877 ft² |
| Volume | 46648 m³ 1,647,134 ft³ |
37241 m³ 1,314,973 ft³ |
29555 m³ 1,043,579 ft³ |