OPERA experimentとは 意味・読み方・使い方

The OPERA experiment (Oscillation Project with Emulsion-tRacking Apparatus) has been designed to perform a test of the phenomenon of neutrino oscillations. This experiment exploits the CNGS high-intensity and high-energy beam of muon neutrinos produced at the CERN Super Proton Synchrotron in Geneva pointing towards the LNGS underground laboratory at Gran Sasso, 730 km away in central Italy. OPERA is located in the Hall C of LNGS and it is aimed at detecting for the first time the appearance of tau neutrinos from the oscillation of muon neutrinos during their 3 millisecond travel from Geneva to Gran Sasso. In OPERA, taus resulting from the interaction of tau neutrinos will be observed in "bricks" of photographic emulsion films interleaved with lead plates. The apparatus contains about 150 thousand of such bricks for a total mass of 1300 tons and is complemented by electronic detectors (trackers and spectrometers) and ancillary infrastructure. Its construction was completed in the spring of 2008 and the experiment is currently collecting data. On May 31, 2010, OPERA Researchers announced the first direct observation of a tau particle in a muon neutrino beam.