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the successor experiment to the Sudbury Neutrino Observatory Now that the SNO experiment has completed taking data and has returned its heavy water, the detector is being renovated and upgraded in order to fill its core with liquid scintillator, turning it into a new experiment. The linear alkylbenzene that has the best optical properties is produced by Petresa Canada’s plant in Bécancour, QC. SNO+ scientists have developed a new liquid scintillator for use in neutrino experiments. Linear alkylbenzene is the basis of a safe and inexpensive scintillating liquid that gives off 50-100 times more light than water. Neutrino Physics Goals of SNO+ SNO+ is a multi-purpose neutrino detector that addresses questions in diverse fields including particle physics, astrophysics and geosciences. Double Beta Decay Known process Does this exist? Neodymium, a rare earth element, will be added to the liquid scintillator in SNO+ (at 0.1% by weight). This will enable a search for neutrinoless double beta decay of the isotope 150Nd. Discovery of this rare decay process would reveal whether neutrinos are their own antiparticles or not and can determine the absolute neutrino mass scale. Low Energy Solar Neutrinos SNO+ will detect solar neutrinos with lower energies than SNO. This will enable precision studies of neutrino oscillations and the coupling between neutrinos and dense matter. SNO+ will detect the pep and CNO solar neutrinos, helping us understand the nuclear reactions that power the Sun. Geo Neutrinos Existing SNO phototubes (being inspected in the photo above) will detect the scintillation light. Work in the SNO Cavity (in the photos above and right) to install anchors in the floor. The Earth glows with antineutrinos because of the natural radioactivity of its interior, mainly from uranium and thorium. SNO+ can detect these geo neutrinos. How much of Earth’s heat is radiogenic? What models of Earth’s chemical origin are valid? Composition of the continental crust? SNO+ data will help answer these questions. The local geology around Sudbury is well characterized, making this an ideal site for geo neutrino measurements. Detector operator “watching” for a burst of supernova neutrinos. Queen’s University University of Alberta Laurentian University SNOLAB TRIUMF Brookhaven National Laboratory University of California, Berkeley University of Pennsylvania University of Washington Armstrong Atlantic State University Black Hills State University University of North Carolina University of Oxford University of Sussex Queen Mary University of London University of Leeds University of Liverpool University of Sheffield LIP Lisbon and Coimbra TU-Dresden Project Milestones and Schedule Reactor Neutrinos Nuclear power reactors emit antineutrinos that SNO+ will detect. SNO+ will study reactor neutrino oscillations, probing physics beyond the Standard Model. Supernova Neutrinos The SNO+ acrylic vessel filled with liquid scintillator (0.86 g/cm3) will be buoyant. A new hold-down system with a rope net has been installed Rope net installation from atop the on top of the vessel, and is phototube structure (photo above). tied to the floor anchors. Collaborating Institutions SNO+ can detect the huge burst of neutrinos which comes from a supernova – the collapse and explosion of a massive star – in our galaxy. Analysis of these neutrinos will add much to the understanding of these important astrophysical processes and provide a glimpse at neutrino properties (neutrino mass and mixing) that are affected by energetic and dense astrophysical environments. Apr 05 NSERC-funded R&D begins Nov 06 SNO detector switched off Apr 07 NSF funds SNO+ research group in the US May 07 SNO heavy water removed, inspections begin Aug 07 SNOLAB approves SNO+ space & resources Jan 08 IPP approves SNO+ as an official IPP project Apr 08 NSERC funds transition, construction activities Sep 08 FedNor support for development of SNO+ CFI Jun 09 CFI funds the SNO+ and DEAP Projects Feb 10 STFC awards funds to SNO+ UK Sep 10 FCT Portugal funding of LIP Lisbon and Coimbra Sep 11 Anchors and floor liner installed in Cavity Oct 11 New SNO+ electronics installed Jan 12 Hold-down rope net installed on AV Feb 12 First SNO+ air-filled detector running Summer 12 Sanding of AV to remove radon isotopes Fall 12 Begin installation of scintillator purification plant. Early 2013 commissioning scintillator process systems Early 2013 SNO+ water-filled detector running Mid 2013 Begin filling SNO+ with liquid scintillator Mid 2013 START OF SNO+ DATA TAKING!