Question:
Measurements at the SNO Laboratory began in 1999what about The SNO detector ?

Answer: The SNO detector consists of 1000 tonnes of ultra-pure heavy water enclosed in a 12-meter diameter acrylic plastic vessel, which in turn is surrounded by ultra-pure ordinary water in a giant 22-meter diameter by 34-meter high cavity. Outside the acrylic vessel is a 17-meter diameter geodesic sphere containing 9,456 light sensors or photomultiplier tubes, which detect tiny flashes of light emitted as neutrinos are stopped or scattered in the heavy water. The flashes are recorded and analyzed to extract information about the neutrinos causing them. At a detection rate on the order of 10 per day, many days of operation are required to provide sufficient data for a complete analysis. The laboratory includes electronics and computer facilities, a control room, and water purification systems for both heavy and regular water.

The construction of the SNO Laboratory began in 1990 and was completed in 1998 at a capital cost of $73M CDN with support from the Natural Sciences and Engineering Research Council of Canada, the National Research Council of Canada, the Northern Ontario Heritage Foundation, Industry, Science and Technology Canada, Inco Limited, the United States Department of Energy, and the Particle Physics and Astronomy Research Council of the U.K. The heavy water is on loan from Canada's federal agency AECL with the cooperation of Ontario Power Generation, and the unique underground location is provided through the cooperation and support of Inco Limited.