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SNO+ is an underground physics experiment under construction (as of Nov 2015) that makes use of the equipment already installed underground for the former Sudbury Neutrino Observatory (SNO) experiment at SNOLAB. The main goals of the project are a search for neutrinoless double beta decay, the measurement of proton–electron–proton (''pep'') solar neutrinos, geoneutrinos from radioactive decays in the Earth, and reactor neutrinos. It will also be possible to observe supernovae neutrinos if a supernova should occur in our galaxy. ==Testing and construction== Testing (filled with water) is expected to begin early 2016, with full operation with liquid a few months after that, and the Te-loaded phase in 2017.〔 〕 In order to reach these goals, linear alkyl benzene will be used as a liquid scintillator and target material.〔 〕 Measurement of neutrinoless double beta decay will also be made by adding to the scintillator.〔 〕 A mass of many tons of double beta decaying material could be added to the experiment. This would make SNO+ the largest experiment to study neutrinoless double beta decay. A neutrino interaction with this liquid produces several times more light than an interaction in a water Cherenkov experiment such as the original SNO experiment or Super-Kamiokande. The energy threshold for the detection of neutrinos therefore can be lower, and proton–electron–proton solar neutrinos (with an energy of ) can be observed. In addition, a liquid scintillator experiment can detect anti-neutrinos like those created in nuclear fission reactors and the decay of thorium and uranium in the earth. The project received funding for initial construction from NSERC in April 2007, and as of early 2013, the cavity had been refurbished and re-sealed to the new cleanliness standards, which are (due to the experiment's greater sensitivity) more stringent than for the original SNO. The main engineering challenge is that the current SNO vessel is supported by a series of ropes, to prevent the weight of the heavy water inside from sinking it in the surrounding normal water. The proposed liquid scintillator (linear alkyl benzene) is lighter than water, and must be held down instead, but still without blocking the view of its interior. The existing support rope attachment points, cast into the acrylic sphere's equator, are not suitable for upside-down use. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「SNO+」の詳細全文を読む スポンサード リンク
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