mine near Sudbury, Ontario. SNO is a heavy-water Cherenkov detector that is
designed to detect neutrinos produced by fusion reactions in the sun. It uses 1000 tonnes of heavy water contained in a 12 meter diameter acrylic vessel. Neutrino's react with the heavy water (D2O) to produce flashes
of light called Cherenkov radiation.
This light is then detected by an array of 10,000 photomultiplier tubes mounted on a geodesic support structure surrounding the heavy water vessel.
The detector is
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 rock shields the detector from
majority of the cosmic rays, and allows you to only view reactions caused by the more powerful rays, ie the ones from our sun. The detector laboratory is extremely clean to reduce background signals from radioactive elements
present in the mine dust which would otherwise hide the very weak signal from neutrino's.
