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MINOS (or Main Injector Neutrino Oscillation Search) is a particle physics experiment designed to study the phenomena of neutrino oscillations, first discovered by a Super-Kamiokande (Super-K) experiment in 1998. Neutrinos produced by the NuMI ("Neutrinos at Main Injector") beamline at Fermilab near Chicago are observed at two detectors, one very close to where the beam is produced (the ''near detector''), and another much larger detector 735 km away in northern Minnesota (the ''far detector''). The MINOS experiment started detecting neutrinos from the NuMI beam in February 2005. On 30 March 2006, the MINOS collaboration announced that the analysis of the initial data, collected in 2005, is consistent with neutrino oscillations, with the oscillation parameters which are consistent with Super-K measurements.〔 〕 MINOS received the last neutrinos from the NUMI beam line at midnight on 30 April 2012.〔(【引用サイトリンク】url=http://homepages.spa.umn.edu/~strait/minos/MINOS_runs )〕 It has been upgraded to MINOS+ which started taking data in 2013 for 3 years. ==Detectors== There are two detectors in the experiment. *The near detector is similar to the far detector in design, but smaller in size with a mass of (t). It is located at Fermilab, a few hundred meters away from the graphite target which the protons interact with, and approximately 100 meters underground. The commissioning of the near detector was completed in December 2004, and it is now fully operational. *The far detector has a mass of . It is located in the Soudan mine in Northern Minnesota at a depth of 716 meters. The far detector has been fully operational since summer 2003, and has been taking cosmic ray and atmospheric neutrino data since early in its construction. Both MINOS detectors are steel-scintillator sampling calorimeters made out of alternating planes of magnetized steel and plastic scintillators. The magnetic field causes the path of a muon produced in a muon neutrino interaction to bend, making it possible to distinguish interactions with neutrinos from those with antineutrinos. This feature of the MINOS detectors allows MINOS to search for CPT-violation with atmospheric neutrinos and anti-neutrinos. 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「MINOS」の詳細全文を読む スポンサード リンク
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