Sudbury Neutrino Observatory (SNOLAB) International Laboratory for Particle Physics Inaugurated In Canada

The gigantic SNO+ detector, another installation at SNOLAB.
Credit: SNOLAB

In May 1999, the Sudbury Neutrino Observatory started operation. It was designed to detect solar neutrinos through its interaction with water.

To build the detector, a large deep cavity was constructed 6,800 feet (~2 km) underground in Vale Inco's Creighton Mine in Sudbury, Ontario, Canada.

In 2002, SNO received funding to expand its facilities into a general purpose laboratory. By March 2011, the entire lab entered operation as a "clean" space.

The original SNO equipment is being upgraded for use in future experiments. The facility currently hosts three experiments:

The PICASSO: dark matter search,
The POLARIS underground project(PUPS): observing seismic signals at depth in very hard rock, and
The DEAP-1: dark matter search.

Although SNOLAB is accessed through a commercial mine owned by Vale Inco, The lab 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 rays, providing a low-background environment for experiments requiring high sensitivities and extremely low counting rates.

Université de Montréal students check a PICASSO dark matter detector at the SNOLAB laboratory.Credit: PICASSO Project

Professor François Schiettekatte of the Université de Montréal’s Department of Physics and the university’s representative on the SNOLAB Board explains the importance of SNOLAB. “Beyond the experiments such as PICASSO that may hopefully shine light on what the Universe’s dark matter is made of, there are many other experiments that will help us to better understand, better detect, and to in fact use neutrinos to observe phenomena that have been beyond us until this point in time. Thanks to neutrinos, we have been able to confirm and learn things about the way the heart of the Sun works. As neutrinos are practically unstoppable – even lead light-years thick wouldn’t do it – they escape from the heart of objects with little ‘alteration.’”

Inauguration of the SNOLAB International Laboratory for Particle Physics

The University of Montreal (UdeM) and its partners are launching SNOLAB, an underground particle physics laboratory that grew out of a collaboration between the university's researchers and their colleagues at Carleton, Queen's, Alberta and Laurentian.

The lab is situated 2km beneath the surface of the Earth and will enable researchers ton answer fundamental questions about the history and the composition of the Universe. They will also be able to use the infrastructure to conduct research into the nature of supernovas, our own star – the Sun – and Earth itself. SNOLAB will indeed be at the heart of a wide range of experiments, including PICASSO, an international project that is being lead by UdeM researchers. "In terms of current and future experiments, around half about the detection of dark matter in the Universe and 'weakly interacting massive particles' or 'WIMPs' in particular. PICASSO is one such research project. WIMPs are in fact particules that we do not know anything about and that would be a part of what we call 'new physics'," explained PICASSO Project Leader Professor Viktor Zacek, of the University of Montreal's Department of Physics. "In fact, the presence of dark energy and dark matter are proof that we are still very far from having completely understood physics and the world that surrounds us."

Video: Science At SNOLAB

Dark energy is at the heart of a theory that would explain various phenomena in our universe, such as the acceleration of its expansion. Dark matter is a form of matter that can currently only be observed by its gravitational effects. Astrophysicists deduct its existence by observing properties of galaxies and their distribution in the universe, but they can not visualize it directly and its nature remains unknown.

Situated in the Vale Inco company's Creighton Mine, near Sudbury, Ontario, SNOLAB is in fact an extension of the Sudbury Neutrino Observatory. The research that takes place there covers the following subjects:

Low energy solar neutrinos
Geo-neutrinos from inside Earth
Double beta disintegration without neutrino emission
Particles that make up dark matter
Neutrinos produced by supernovas

Université de Montréal researchers and students work inside the PICASSO dark matter detector set up at the SNOLAB laboratory. Credit: PICASSO Project

On the detector's ability to detect supernovas, Schiettekatte adds, “They can therefore be used to deduce what happened at the moment of supernova eruption, a phenomenon whose mechanisms are still beyond us, or even to obtain information about the internal structure of our own planet: geoneutrinos, who come from spontaneous nuclear disintegrations inside Earth. And although their secrets won’t be revealed tomorrow, there are also the fossil rays of neutrinos, who might permit us to have an even closer echo of the beginning of the Big Bang than fossil microwave rays.”

The experiments needed for research in these areas require a reduction in the background noise caused by cosmic and radio-isotopic radiation, which explains why the SNOLAB was constructed deeply underground.

Professor Zacek's experiments involve the new infrastructure. "This laboratory, specialized in neutrino physics – basic particles – and in dark matter will guide our work towards a better understanding of the Universe, of which we still know nothing about 96% of its composition. Who knows? Maybe we will be able to reconstitute the first moments of the Big Bang in an observatory 2000 metres below the Earth's surface!"

Video: SNOLAB Grand Opening (17 May 2012)