Jiangmen Underground Neutrino Observatory

Coordinates: 22°07′06″N 112°31′07″E / 22.11827°N 112.51867°E / 22.11827; 112.51867The Jiangmen Underground Neutrino Observatory (JUNO) is a medium baseline reactor neutrino experiment under construction at Kaiping, Jiangmen in Southern China. It aims to determine the neutrino mass hierarchy and perform precision measurements of the Pontecorvo–Maki–Nakagawa–Sakata matrix elements. It will build on the mixing parameter results of many previous experiments. The collaboration was formed in July 2014 and construction began January 10, 2015. The schedule aims to begin taking data in 2020.:3 Funding is provided by the Chinese Academy of Sciences, but the collaboration is international. Coordinates: 22°07′06″N 112°31′07″E / 22.11827°N 112.51867°E / 22.11827; 112.51867The Jiangmen Underground Neutrino Observatory (JUNO) is a medium baseline reactor neutrino experiment under construction at Kaiping, Jiangmen in Southern China. It aims to determine the neutrino mass hierarchy and perform precision measurements of the Pontecorvo–Maki–Nakagawa–Sakata matrix elements. It will build on the mixing parameter results of many previous experiments. The collaboration was formed in July 2014 and construction began January 10, 2015. The schedule aims to begin taking data in 2020.:3 Funding is provided by the Chinese Academy of Sciences, but the collaboration is international. Planned as a follow-on to the Daya Bay Reactor Neutrino Experiment, it was originally planned for the same location, but the construction of a third nuclear reactor (the planned Lufeng nuclear power plant) in that area would disrupt the experiment, which depends on maintaining a fixed distance to nearby nuclear reactors.:9 Instead it was moved to a location 53 km from both of the planned Yangjiang and Taishan nuclear power plants.:4 The main detector consists of a 35.4 m (116 ft) diameter transparent acrylic glass sphere containing 20,000 tonnes of linear alkylbenzene liquid scintillator, surrounded by a stainless steel truss supporting approximately 53,000 photomultiplier tubes (17,000 large 20-inch (51 cm) diameter tubes, and 36,000 3-inch (7.6 cm) tubes filling in the gaps between them), immersed in a water pool instrumented with 2000 additional photomultiplier tubes as a muon veto.:9 Deploying this 700 m (2,300 ft) underground will detect neutrinos with excellent energy resolution. The overburden includes 270 m of granite mountain, which will reduce cosmic muon background.