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The Cryogenic Underground Observatory for Rare Events (CUORE) is a particle physics facility located at the Laboratori Nazionali del Gran Sasso in central Italy. CUORE was designed primarily as a search for neutrinoless double beta decay (0νββ) in 130Te. It uses tellurium dioxide (TeO2) crystals as both the source of the decay and as bolometers to detect the resulting electrons. These decays have never been observed; an observation would conclusively show that neutrinos are Majorana fermions; that is, they are their own antiparticles.〔 This is relevant to many topics in particle physics, including lepton number conservation, nuclear structure, and neutrino masses and properties. CUORE searches for the characteristic signal of 0νββ, a small peak in the observed energy spectrum around the known decay energy: ''Q'' = 2527.518±0.013 keV. CUORE can also search for signals from dark matter candidates, such as axions and WIMPs. The CUORE collaboration involves physicists from several countries, primarily from the United States and Italy.〔(【引用サイトリンク】title=Cuore - Institutions )〕 CUORE is funded by the Istituto Nazionale di Fisica Nucleare (INFN) of Italy, the United States Department of Energy (DOE), and National Science Foundation (NSF) of the United States. In September 2014, as part of the testing of the CUORE dilution refrigerator, scientists in the CUORE collaboration cooled a copper vessel with a volume of one cubic meter to 6 mK (0.006 K, −273.144 °C) for 15 days, setting a record for the lowest temperature in the universe over such a large contiguous volume. == Detectors == The CUORE detectors are TeO2 crystals used as low heat capacity bolometers, arranged into towers and cooled in a large cryostat to approximately 10 mK with a dilution refrigerator. The detectors are isolated from environmental thermal, electromagnetic, and other particle backgrounds by ultrapure low-radioactivity shielding. Temperature spikes from electrons emitted in Te double-beta decays are collected for spectrum analysis. The detectors are calibrated using 232Th, the first element in a long decay chain that includes several prominent gamma rays up to 2615 keV. Considerable effort was aimed at minimizing radioactive contamination in the construction of CUORE, which can cause the detectors to register background events at energies close to the energy released in neutrinoless double beta decay. The crystals were grown by the Shanghai Institute of Ceramics at the Chinese Academy of Sciences with strict radiopurity requirements. The crystals are held in place by PTFE support in towers constructed from oxygen-free high thermal conductivity copper, and were assembled under nitrogen inside glove boxes in clean rooms. Copper, lead, ancient low-radioactivity Roman lead, and borated polyethylene are used to shield the detectors. Coincidence algorithms have been used to reject events that caused multiple channels to trigger, such as would be caused by an incoming cosmic ray muon. 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「CUORE」の詳細全文を読む スポンサード リンク
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