SNO Logo The Sudbury Neutrino Observatory

The Sudbury Neutrino Observatory (SNO) results have provided revolutionary insight into the properties of neutrinos and the core of the sun. The detector, shown in the artist's conception below, was built 6800 feet under ground, in INCO's Creighton mine near Sudbury, Ontario, Canada. SNO was a heavy-water Cherenkov detector designed to detect neutrinos produced by fusion reactions in the sun. It used 1000 tonnes of heavy water loaned from Atomic Energy of Canada Limited (AECL), and contained by a 12 meter diameter acrylic vessel. Neutrinos reacted with the heavy water (D2O) to produce flashes of light called Cherenkov radiation. This light was then detected by an array of 9600 photomultiplier tubes mounted on a geodesic support structure surrounding the heavy water vessel. The detector was immersed in light (normal) water within a 30 meter barrel-shaped cavity (the size of a 10 story building!) excavated from Norite rock. Located in the deepest part of the mine, the overburden of rock shielded the detector from cosmic rays. The detector laboratory, still functioning as part of the new SNOLAB facility, is extremely clean to reduce background signals from radioactive elements present in the mine dust which would otherwise hide the very weak signal from neutrinos. Plans are currently underway to upgrade the SNO detector for the new SNO+ experiment.

For interesting accounts of the early development work for the SNO experiment, please see:
"Early Development of the Underground SNO Laboratory in Canada" and "The Funding Campaign for the Sudbury Neutrino Observatory", G.T. Ewan and W.F. Davidson, Physics in Canada, Vol. 61, No. 6 (2005), p. 339-346 and 347-350. (download in PDF format)
For a review article summarizing the three phases of the SNO experiment, please see:
"The Sudbury Neutrino Observatory", Nick Jelley, Arthur B. McDonald, and R.G. Hamish Robertson, Annu. Rev. Nucl. Part. Sci. 2009.59:431-465. (download in PDF format)
Artist Concept of SNO

Recent News

In Memoriam: Andre Hamer 1968-2003

Physics Documents

SNO Web Pages on This Site

SNO Web Sites at Participating Institutions

Present Status

Also see SNO Milestones for a history of SNO milestones

The Sudbury Neutrino Observatory Institute (SNOI):

SNO Project Director:

Dr. A.B. McDonald (Queen's University)
The Sudbury Neutrino Observatory Institute

Department of Physics, Stirling Hall,
Queen's University at Kingston,
Kingston, Ontario, Canada
K7L 3N6

Tel: (613) 533-2702
Fax: (613) 533-6813

SNO Institute Director:

Dr. Tony Noble (Queen's University)
The Sudbury Neutrino Observatory Institute

Department of Physics, Stirling Hall,
Queen's University at Kingston,
Kingston, Ontario, Canada
K7L 3N6

Tel: (613) 533-2679
Fax: (613) 533-6813

The SNO Site Project Office:

SNO Operations Control Building


INCO Creighton #9 Mine
P.O. Box 159
Lively, Ontario, Canada
P3Y 1M3

Tel: (705) 692-7000
Fax: (705) 692-7001

For general information email: snoinfo@surf.sno.laurentian.ca

URL: http://www.sno.phy.queensu.ca/sno/ (Last revised Apr 10, 2014)
(Mail problems/comments to qusno@sno.phy.queensu.ca)