SNO+ is a detector located 2.1km under the rocks of Canada's SNOLAB in Sudbury, Western Ontario. The primary aim of the SNO+ experiment is to detect neutrinoless double beta decay, an extremely rare and as yet unobserved nuclear decay which is connected to the fundamental nature of neutrinos themselves. The detector consists of 780T of liquid scintillator held in an acrylic vessel suspended in 20kT of ultra-pure water. Over 9000 photomultiplier tubes watch the scintillator for faint traces of light. The neutrinoless double beta decay search will begin in earnest when the scintillator is loaded with tellurium.
At the same time, SNO+ is sensitive to neutrinos from elsewhere in the Earth, including nearby nuclear reactors; neutrinos produced in the atmosphere from cosmic ray collisions; as well as neutrinos from the sun and exploding stars. The Oxford group is active in a broad range of the SNO+ physics programme, and its connection to the experiment goes back not only to the inception of the neutrinoless double beta decay search, but also to the detector's earlier, Nobel Prize-winning days as SNO.