[](logos.html)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 VALE's [Creighton mine](images/mine.GIF) 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](D2O.html) loaned from Atomic Energy of Canada Limited (AECL), and contained by a 12 meter diameter acrylic vessel. [Neutrinos](neutrino.html) 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](images/snoball.jpg) surrounding the heavy water vessel. The detector was immersed in light (normal) water within a 30 meter barrel-shaped [cavity](images/cavity.JPG) (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](https://www.snolab.ca/) 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+](https://snoplus.phy.queensu.ca/) experiment.
> The first co-spokesmen for the SNO collaboration when it was established in 1984 were Professor Herb Chen from U California, Irvine and Professor George Ewan, Queen’s University. 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](papers/EwanAndDavidsonEarlyDevelopmentofSNO.pdf))
> 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](papers/JelleyMcDonaldRobertsonAnnRev2009.pdf))
[](images/man_on_deck.GIF)
Recent News
-----------
* **Nov. 8, 2015:** SNO shares the [2016 Breakthrough Prize in Fundamental Physics](https://breakthroughprize.org/Laureates/1/L151).
* **Oct. 6, 2015:** Art McDonald shares the [2015 Nobel Prize in Physics](https://www.nobelprize.org/nobel_prizes/physics/laureates/2015/).
* **July 2013:** [Cocconi Prize of the European Physical Society awarded to the SNO and SuperKamiokande Experiments](https://www.snolab.ca/news/2013-05-20-cocconi-prize-european-physical-society-awarded-sno-and-superkamiokande-experiments).
* **Sept. 9, 2011:** Art McDonald awarded the [Henry Marshall Tory Medal of the Royal Society of Canada](https://www.queensu.ca/physics/dr-art-mcdonald-awarded-henry-marshall-tory-medal).
* **Apr. 14, 2011:** David Sinclar awarded the [2011 CAP-TRIUMF Vogt Medal](https://www.triumf.ca/headlines/awards-honours/1st-cap-triumf-medal-goes-david-sinclair).
* **Apr. 13, 2010:** Art McDonald awarded the [2010 Killam Prize](https://canadacouncil.ca/funding/prizes/killam-prizes).
* **Nov. 12, 2009:** [SNO Technical Reports](str/index.html) now available for download.
* **May 15, 2009:** [Art McDonald elected to UK Royal Society](https://www.queensu.ca/physics/dr-art-mcdonald-elected-uk-royal-society).
* **June 5, 2008:** NCD-phase results released. ([paper in PDF format](papers/ncd_prl_final.pdf))
* **Apr. 26, 2007:** Art McDonald awarded the [2007 Franklin Medal in Physics](http://www.fi.edu/tfi/exhibits/bower/07/laureates/franklin_physics.html).
* **Feb. 20, 2007:** Art McDonald appointed to [the Order of Canada](https://www.queensu.ca/physics/dr-art-mcdonald-receives-order-canada-award).
* **Nov. 15, 2006:** SNO celebrates the [receipt of the John C. Polanyi Prize from NSERC](https://cou.on.ca/about/awards/john-charles-polanyi/prize-winners/) and the completion of very successful operations with heavy water. Read the press release ([PDF](press_release/SNONewsReleaseNov15r.pdf), [DOC](press_release/SNONewsReleaseNov15r.doc)) and backgrounder ([PDF](press_release/SNOBackgrounderNov15f.pdf), [DOC](press_release/SNOBackgrounderNov15f.doc)) for details.
In Memoriam: [Andre Hamer 1968-2003](andre/)
--------------------------------------------
* [Andre Hamer Postgraduate Prizes](https://www.nserc-crsng.gc.ca/Prizes-Prix/Hamer-Hamer/Index-Index_eng.asp) (Dec. 2, 2004)
Physics Documents
-----------------
* [Combined Analysis of all Three Phases of Solar Neutrino Data from the Sudbury Neutrino Observatory](papers/PhysRevC.88.025501.pdf)\[Phys. Rev. Lett. C88, 025501 (2013)\]
* [NCD-phase SNO-only chi-squared map](papers/ncd_chi2/) for the neutrino mixing-parameter analysis \[Phys. Rev. Lett. 101, 111301 (2008)\]
* [Salt-phase SNO-only chi-squared map](papers/nsp_chi2/) for the neutrino mixing-parameter analysis \[Phys. Rev. C72, 055502 (2005)\]
SNO Web Pages on This Site
--------------------------
* [Publications](publications.html)
* [SNO Technical Reports](str/index.html) (November 12, 2009)
* [SNO Periodicity Analyses](periodicity/) (April 19, 2021)
* [Salt Phase Results](results_09_03/) (September 7, 2003)
* [Neutral Current and Day/Night Results](results_04_02/) (April 20, 2002)
* [First Scientific Results from SNO](first_results/) (June 18, 2001)
* [About Neutrinos and the Solar Neutrino Problem](neutrino.html)
* [Description of SNO Detector](sno2.html)
* [SNO Image Catalog](images/)
* [Computer-Generated Images of SNO Events](events/)
* [The SNO Collaboration](collaboration.html)
* [Participating Institutions](institutions.html)
* [SNO Contact People](contacts.html)
* [SNO Conference Talks (2003 and earlier)](talks/2003.html)
* [SNO at the Neutrino 2000 Conference](nu2000/)
* [Publicity: TV, Newspapers...](publicity.html)
* [Employment in SNO](jobs.html)
* [Links to Particle Physics Sites](experiments.html)
* [Other Links of Interest](other_links.html)
* [Internal SNO Documents (Access Restricted)](private/restricted_sno.html)
SNO Web Sites at Participating Institutions
-------------------------------------------
* [SNOLAB Home Page](https://www.snolab.ca/)
* [Queen's University](group/)
* [Lawrence Berkeley National Laboratory](https://neutrino.lbl.gov/index.html)
* [University of Pennsylvania](https://www.hep.upenn.edu/SNO/)
* [University of Washington](http://ewiserver.npl.washington.edu/sno/)
* [Oxford University](https://www2.physics.ox.ac.uk/Neutrino/SNO/)
* [Los Alamos National Laboratory](https://lanldb1.lanl.gov/wi/home.nsf)
* [University of British Columbia](https://www.physics.ubc.ca/~oser/sno/)
* [Carleton University](https://www.physics.carleton.ca/research/sno)
* [University of Guelph](https://eta.physics.uoguelph.ca/sno/)
* [Laurentian University](https://laurentian.ca/physics/SNO/SNO_FR.HTML)
* [Brookhaven National Laboratory](https://www.chemistry.bnl.gov/sn/)
* [University of Texas at Austin](https://www.hep.utexas.edu/sno/)
* [LIP-Lisboa](https://www.lip.pt/experiments/sno/)
* [Massachusetts Institute of Technology](https://www2.lns.mit.edu/neutrino/)
Present Status
--------------
* **May 28, 2013:** SNO publishes final combined 3-phase analysis download [PDF](papers/PhysRevC.88.025501.pdf)).
* **June 5, 2008:** SNO publishes NCD-phase results (download [PDF](papers/ncd_prl_final.pdf)).
* **May 28, 2007:** Heavy water completely drained from acrylic vessel.
* **November 28, 2006:** End of data aquisition with NCD's and heavy water.
* **February 28, 2005:** SNO publishes 391-day salt-phase results (download [PDF](papers/0502021.pdf), [Postscript](/sno/papers/0502021.ps) or [figures](papers/0502021_figs/)).
* **January 2005:** Production data taking with NCD array installed.
* **April 21, 2004:** NCD testing and repairing is complete and the ROV is removed from the detector.
* **February 12, 2004:** The NCD's are all installed and we begin the third phase of detector operation.
* **September 2003:** Salt is removed from the heavy water
* **September 7, 2003:** SNO releases [Salt Phase Results](/sno/results_09_03/).
* **May 2003:** NCD pre-deployment welding has just been completed. NCD deployment is scheduled for August.
* **June 20, 2002:** [The International Facility for Underground Science receives funding](https://www.innovation.ca/media/index.cfm?websiteid=227)
* **April 20, 2002:** [New scientific results](results_04_02/) released.
* **June 2001:** SNO releases its [First Scientific Results](/sno/first_results/) on Monday, Jun 18 at 12:15 EDT.
* **May 2001:** Salt has been added to the heavy water to enhance the [neutral current efficiency](/sno/sno2.html#nc). This marks the beginning of the second phase of detector operation.
* **June 2000:** [SNO presentations at Neutrino 2000](nu2000/) give the current detector status.
* **November 1999:** Detector parameters frozen. Start of production data taking.
Also see [SNO Milestones](publicity.html#milestones) for a history of SNO milestones
The Sudbury Neutrino Observatory Institute (SNOI):
--------------------------------------------------
#### SNO Project Director:
[Dr. A.B. McDonald](people/mcdonald.html) _(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
VALE Creighton #9 Mine
P.O. Box 159
Lively, Ontario, Canada
P3Y 1M3
Tel: (705) 692-7000
Fax: (705) 692-7001
For general information email: [[email protected]](mailto:[email protected])
**URL: https://www.sno.phy.queensu.ca/sno/** _(Last revised Nov 9, 2015)_
_(Mail problems/comments to [[email protected]](mailto:[email protected]))_