Grant: Subatomic Physics Envelope - Project

SNO+ is the follow-up experiment to the Sudbury Neutrino Observatory (SNO). With a liquid scintillator in place of the heavy water that was in the SNO detector, a new experiment with extended sensitivity at lower energies is being built. SNO+ will be able to address fundamental questions in particle physics, in geosciences, and in astrophysics. SNO+ will start where SNO left off and it will expand our understanding of the neutrino and its impact on the physical universe. A liquid scintillator emits 50-100 times more light when a neutrino interacts in it compared to a neutrino interaction in water. Consequently SNO+ will be able to detect neutrinos with lower energies than SNO. Lower energy neutrinos from the Sun will be studied to shed light on the properties of neutrinos and the energy generation processes in stars. Separately, antineutrinos from natural radioactivity in the Earth will be detected by SNO+. The number of ""geo neutrinos"" observed will be related to the total amount of uranium and thorium radioactivity in the deep Earth. SNO+ geo neutrinos could thus provide transformative data related to the fraction of Earth's heat that originates from radioactivity. Finally, an extremely rare nuclear decay will also be studied in SNO+ by dissolving neodymium in the liquid scintillator. Observation of this process, known as neutrinoless double beta decay, would tell physicists about the matter-antimatter properties of the neutrino, which is connected to cosmological questions about matter and antimatter in the Universe. SNO+ received full infrastructure (capital) funding in the 2009 CFI competition. The detector is now being built and will be filled in 2013. This proposal requests funds to support SNO+ research activities at Queen's, Alberta, Laurentian, SNOLAB and TRIUMF. These activities include final construction, commissioning the new detector and the start of data taking.